ASIC (Application Specific Integrated Circuit) and custom logic typically are unforgiving systems since an error in the logic may not allow for an easy recovery once the device has been fabricated. The re-design cycle time can be 3-4 months. An FPGA (Field Programmable Gate Array), however, is an on the fly reconfigurable Boolean logic system. The heart of Reconfigurable logic is the configurable logic block which is formed using Boolean logic and can be altered very easily since an input digital signal can modify the operation of the logic block without physically altering it. The ability to program, use, reprogram, use and reprogram, use and continue this cycle infinitum are features very desirable which allow a system to adapt to different changing specifications or conditions quickly. The re-design cycle can be done in seconds. This helps explain why the reconfigurable logic business has grown into a several billion dollar enterprise.
Reconfigurable systems are very useful and allow for a rapid change to the system to achieve the desired behavior in a short time period. There are situations where some systems that would desire the ability to be reconfigurable but currently are not able to do so. These systems contain a component that is a discrete element: inductor, capacitor or antenna. It is difficult to replace these discrete elements with switches formed from active circuitry since the circuitry introduces loss and degrades the characteristics of the discrete elements. An RF (Radio Frequency) switch is used to switch the antenna from the transmitter to the receiver and the switch itself unfortunately introduces a loss of about 0.5 db. This is because it is difficult to replace metal with active components. In order to switch in a different value of an inductor, a first switch must disconnect the first inductor and a second switch must connect the new inductor. However, the switch introduces a loss and reduces the Q of the inductor; this is typically an undesirable effect. Finally, variable capacitors are currently formed by active devices; diodes or MOS gates, etc. These capacitors can behave nonlinearly and have a limited range of linear operation over a given voltage range.
In addition, wireless systems are comprised of hardware such as transmitters, receivers, DSPs (Digital Signal Processor), memory, D/A (Digital to Analog), A/D, filters and antennas. Typically, the wireless communication channel in a system may operate in a new frequency band. However, the system would perform better if the passive components could be changed to operate at that new frequency band. Since the hardware is physically soldered and bound in place in the system, it is very difficult to replace them with hardware that has been optimized to operate at this newer frequency band. One approach to this problem is to design the hardware so it operates over a larger frequency band. The consequences are a loss in gain and not being able to achieve the ultimate performance with an optimum design.
It would be very desirable to have a system that can be physically reconfigured to adapt to a changing conditions. For example, it would be desirable to have an inductor, antenna, capacitor or other hardware components to be physically alterable after they have been placed in the system. This specification addresses these concerns as described in the following section.
One embodiment is dropping droplets of fluids onto substrates, forming various contact angles, overhanging the droplets over the edge of the substrate and moving two substrates until at least one droplet from each substrate make contact. Then, friction can be applied to the common surface to understand the properties of the surface tension. In addition, potentials can be applied across the membrane to study the diffusion properties and the concentration levels can be adjusted within the droplet to determine its effect. Another embodiment is forming a LOC (Lab on a Chip) where biological fluids and samples can be pumped, mixed, analyzed and confined into cavities. One embodiment of using Coulomb forces is to adjust and align laser from/into optical fibers. Another embodiment allows a pattern of non-overlapping metallic sheets to determine the acceleration of the system. As the acceleration causes the distances between the metallic sheets to vary, the amount of acceleration can be determined. An orthogonal placed pattern of sheets can be used to determine the direction of the acceleration. Such a device can be used to enable air bags during a car crash.
Another embodiment is described which uses Coulomb forces to adjust the physical dimensions of antennas. Thus, antennas can be adjusted in the field to better match the carrier frequency. Several antennas: the Yagi, the patch, the bow-tie, the meanderline, and the dipole antenna can be adjusted to benefit from this adjustment. As more antennas can be placed on a substrate, additional flexibility occurs such as using an antenna at a given carrier frequency to transmit a signal while the second antenna can be used to receive the signal at a different carrier frequency. Conversely, the antennas can be used in a MIMO system to provide a multi-channel wireless communication where the antennas can be moved on the surface of a substrate to improve reception. One embodiment is the ability to rotate an antenna substrate 90° around the edge of a substrate. This allows antennas to be formed that exist in three orthogonal planes. Receiving and transmitting signals in three orthogonal dimensions improves reception if one of the signals fades in a given dimension. Many of these techniques are also applicable to inductor construction.
Another embodiment is described that can assemble substrates over one another to form a stacked substrate. The various layers of the stacked substrate can be separated from each other by using Coulomb forces. One embodiment shows how a beam substrate can be used to increase the separation. The instructions for assembly and a FSM (Finite State Machine) can be included in the stacked substrate to pave the way for a self-constructing 3-D automaton. The beam substrate can be used to carry heat, fluids, electrical power or signals between the various layers of the stacked cells besides providing a mechanical support. The embodiment of a stacked substrate can be assembled into a cylindrical coil, a transformer or a coupled transformer depending on the construction of the beam structure. In one embodiment, the magnetic coupling of the transformer can be altered by changing the distance between the separated substrates.
In another embodiment, metallic plates can be positioned over one another to form capacitor which can be used to detect motion, distance, velocity, position and identity of the substrates. These capacitors can be used to form an LC tank circuit where the distance between the plates of the capacitor can be altered to alter so that the capacitance is altered and the frequency is changed. The capacitor can be used to communicate digital information between the substrates.
In another embodiment, a combination of attractive and repulsive Coulomb forces can be used to form a levitation system using at least two substrates. Another is to have two outer substrates that make a channel region and confine a third substrate within the channel region. The system can be levitated just by using only like charges. In order to introduce further control, some of the islands can be altered in the strength and polarity of their charge to move the third substrate vertically within the channel region.
Another embodiment is increasing the number of Coulomb islands to decrease the required voltage that needs to be applied to the island. This helps in reducing the stress applied to the junctions and devices.
In another embodiment, the substrate can be processed to exposed metallic posts or electrical contacts that can provide a DC connection to provide power and DC signals. In addition the edge can be etched to expose the metal layers in a substrate to allow an electrical connection to occur.
In one embodiment of the invention is a system where the substrates can be reconfigured by the application of adjustable Coulomb forces between juxtaposed surfaces of substrates to create new systems. These forces can be used to detach, raise, move, rotate, drop and reattach substrates into new system configurations. An embodiment of placing a pattern of islands on each juxtaposed substrate and determining the sequence and charging to lift, move and dropping a substrate. The determination is done by a control unit that can be confined to one of the substrates, distributed among several substrates, calculated on the fly, stored in memory, or calculated externally. Feedback from the sensors can be used to control and stabilize the movement of the substrate. The master control can be in the mother substrate.
In another embodiment, a Faraday shield can be placed under the Coulomb island to isolate the Coulomb island from the remainder of the substrate. In addition, the potential of the Faraday shield can be altered to control the electric field leaving the substrate and thereby controlling the force being applied to a juxtaposed Coulomb island. Another embodiment is performing edge processing of a substrate. Vertical Coulomb islands and vertical Faraday shields can be formed. This inventive aspect allows Coulomb islands to be charged to attract two or more substrates along their edge.
In another embodiment, charge is induced in a metallic Coulomb island by an externally charged plate. The Coulomb island can have a probe opening to directly charge the island, and then this charged Coulomb island can be used to induce a charge on another Coulomb island. The probe opening can be mechanically probed using an external probe or a MEMS probe. In another embodiment, the gate of a non-volatile memory that is isolated is connected to a Coulomb island where the entire combined structure is surrounded by an insulator. The island is placed at the surface of the substrate to maximize the forces that can be generated between this island and another island located near the surface of a second substrate. Furthermore, several non-volatile devices can be connected to the island simultaneously where each device can be optimized to perform a special function.
In another embodiment, Coulomb forces are used to detach substrates from the system to decrease leakage current in that substrate to decrease power dissipation. An embodiment allows an inductor on a substrate to be levitated so that losses of the inductor are decreased. Another embodiment is wire bonding a substrate to power and DC supplies and using the Coulomb force to lift the substrate so that the substrate is levitated. Another embodiment is using the Coulomb forces between two substrates to cause one of the substrates to overhang a new substrate which does not have Coulomb islands. However, the substrate over hanging the new substrate can electrically connect to the new substrate to introduce a new circuit element into the new substrate.
Please note that the drawings shown in this specification may not be drawn to scale and the relative dimensions of various elements in the diagrams are depicted schematically and not to scale.
a-1h depict a reconfigurable system in accordance with the present invention.
i) illustrates a side cross-sectional view of the reconfigurable system with the daughter substrates connected and j) levitated to the mother substrate in accordance with the present invention.
k shows a flowchart to reconfigurable the system in accordance with the present invention (Note that the decision unit has a block shape instead of a diamond one).
a depict the diagram used to calculate the force of a charged disk in accordance with the present invention.
b illustrates two charged islands juxtaposed to each other in accordance with the present invention.
c) reveals plot of gravitational force of substrates and the voltage necessary to apply to an island pair, d) a plot of the voltage applied to the islands to maintain a constant force as a function of the number of islands, and d(1)) the forces between a sphere and a plane in accordance with the present invention.
e) presents a portion of a unit component from a reconfigurable system with a surface charge and f-g) depict a portion of a unit, component from a reconfigurable system with an electric field in accordance with the present invention.
a illustrates a chargeable plate in a reconfigurable system in accordance with the present, invention.
b reveals forming an induced charge on a chargeable plate in a reconfigurable system in accordance with the present invention.
c shows the cross sectional view of a probe (could be external or on-substrate) routing excess negative charge to a power supply in a reconfigurable system in accordance with the present invention.
d presents the probe being disconnected in a reconfigurable system in accordance with the present invention.
e depicts the cross sectional view of the electric field from the chargeable plate in a reconfigurable system in accordance with the present invention.
f illustrates the top view of the chargeable plate in a reconfigurable system in accordance with the present, invention.
a and 4c reveal the cross sectional view of the electric field of the chargeable plate after placing a second chargeable plate (forming a Faraday Shield) beneath the initial chargeable plate in a reconfigurable system in accordance with the present invention.
b and 4d show the top view of the chargeable plate in a reconfigurable system in accordance with the present invention.
a) presents the cross sectional view of the Faraday Shield, b) depicts the cross sectional view of a negatively charged plate causing an induced charge to form on a second chargeable plate in a reconfigurable system, c) illustrates a negative probe canceling the excess positive charge of the second chargeable plate of the cross sectional view of the Faraday Shield, d) reveals a negative charge on the second plate, e) the island set to a negative potential and f) the shield set to a negative potential in accordance with the present invention.
a) illustrates a cross sectional view and b) reveals the top view of the FAMOS device illustrating the source, drain, gate and contact window.
c shows the 2-D with perspective of a chargeable plate connected by metallic stacks to the gate of the FAMOS device in accordance with the present invention.
d) presents the cross sectional view 6-22 of
a) illustrates a cross sectional view and b) reveals the top view of the SAMOS device illustrating the source, drain, gates and contact window.
e) presents the cross sectional view of a chargeable plate connected by a metallic stack to the gate of the SAMOS device, d) reveals a Faraday Shield formed beneath the chargeable plate, e) shows the chargeable plate having a positive charge formed either by induced charging or probing and f) presents a voltage adjustable Faraday Shield beneath the chargeable plate in accordance with the present invention.
a) depicts two substrates preparing to be bonded together where one substrate has been given a charge and b) illustrates the charged bonded substrate of
a) reveals a positive charged substrate held by an attractive Coulomb force to the negative charged substrate and b) shows the repulsive Coulomb force between two similarly charged substrates in accordance with the present invention.
a) presents repulsive/attractive charged substrates that are held apart by a repelling Coulomb Force and b) depicts the repulsive/attractive charged substrates (one with less positive charge) causing more separation due to a less attracting Coulomb force in accordance with the present invention.
a) illustrates a region bounded by negative charged substrates where a central wafer bonded substrate levitates within the channel region due to the repelling Coulomb force, b) reveals a second central wafer bonded substrate in a channel and c) presents yet a third embodiment of the central wafer bonded substrate in a channel in accordance with the present invention.
a) depicts two face-to-face positively charged substrates each having posts, b) illustrates the two face-to-face oppositely charged substrates held together by an attractive Coulomb Force, c) reveals a close up of the connected post elements and d) shows yet a further close up of the connected post elements showing the landing areas in accordance with the present invention.
e) depicts two face-to-face positively charged substrates each having a moveable contact post, f) illustrates the two face-to-face oppositely charged substrates held together by an attractive Coulomb force, g) reveals a close up of the un-connected post elements and h) shows a close up of the post elements when connected in accordance with the present invention.
i) presents substrates each having punch-through substrate vias, j) depicts the substrates connected by a solder bump, k) illustrates a close up of the solder bump and l) reveals yet a further close up of the solder bump illustrating the dam structure in accordance with the present invention.
a) shows a packaged system incorporating a levitating Coulomb force device and b) presents a packaged system incorporating a levitating Coulomb force device extracting energy from a magnetic field in accordance with the present invention.
a presents a packaged system incorporating a levitating Coulomb force device containing an inductor, b) depicts a physical layout of an inductor coil and e) illustrates the schematic of the inductor in accordance with the present invention.
a) presents Coulomb islands that are oppositely charged on two juxtaposed substrates causing them to be held together by an attractive Coulomb force and b) depicts the pre-stage charging of islands and their unit vector forces in preparation for moving the top substrate in accordance with the present invention.
c) illustrates the first post-stage charging of islands and their unit vector forces to move the top substrate upward and d) illustrates the first post-stage charging of islands and their unit vector forces as the top substrate moves right in the direction of minimum energy in accordance with the present invention.
e reveals the second post-stage charging of islands and their unit vector forces to move the top substrate further to the right, f) shows the thud post-stage charging of islands and their unit vector forces to position the top substrate to contact the mother substrate and g) presents the timing waveforms of the charges applied to the islands in accordance with the present invention.
a) depicts the post-stage charging of islands and their unit vector forces to move the levitating substrate vertically and b) illustrates a second post-stage charging of islands and their unit vector forces to move the levitating substrate vertically in accordance with the present invention.
a) reveals a 3-D substrate containing 4 Coulomb islands and b) shows the 3-D substrate containing the 4 Coulomb islands (structural outline hidden) superimposed over the mother substrate indicating the unit vectors of force applied to the 4 Coulomb islands in accordance with the present invention.
a) presents single symbols indicating the condition of the charge of the islands, b) depicts the combined symbols created by overlapping the single symbols and c) illustrates several cases of overlapping the single symbols to form the combined symbols in accordance with the present invention.
d) reveals the 2-D surface view of the mother substrate containing a matrix of islands where the islands located at (2, 1), (5, 1), (2, 4) and (5, 4) are charged positive and e) shows the 2-D structural view of the daughter substrate containing the 4 Coulomb islands which are negatively charged in accordance with the present invention.
a) presents the superposition of the daughter substrate placed over the mother substrate illustrating the combined symbols as defined in
a) shows the 2-D structural view of a daughter substrate containing the four negatively charged corner Coulomb islands and two internal islands charged positively, b) presents the superposition of the daughter substrate placed over a mother substrate illustrating the combined symbols as defined in
g) shows that the daughter has rotated another 45° (note that the symbols on the daughter substrate have been corrected due to the 90° rotation) and h) presents the daughter substrate attached to the mother substrate after being rotate 90° in accordance with the present invention.
a) depicts a reconfigurable system consisting of multiple daughter substrates on a mother substrate to receive and transmit laser radiation, b) illustrates a flowchart to position the receiver to the laser radiation and c) reveals a flowchart to position the V-Groove holding fibers to the edge laser in accordance with the present invention.
a) shows a reconfigurable Lab On a Chip (LOG) System consisting of multiple daughter substrates on a mother substrate to receive, mix and analyze biological components, b) defines the contact angle of drops and c-d) illustrates movements of the daughter substrates with drops having large contact angles to make contact with other drops in accordance with the present invention.
e) presents a flowchart to position the cavities to receive samples from a pipette and f) depicts a flowchart to position the containers to deposit reagents into carriers to perform operations and analysis in accordance with the present invention.
a) illustrates a mother substrate carrying three daughter and two granddaughter substrates where one of the granddaughters is repositioned, b) reveals further repositioning of the granddaughter, e) shows the second granddaughter being repositioned and d) presents the final reconfiguration of the second inductor connected to the Microprocessor in accordance with the present invention.
a) depicts an accelerometer comprised of a mother arid daughter substrate having horizontal offset capacitors, b) illustrates an above view of the horizontal offset capacitors, c) reveals a displacement of the daughter substrate due to a deceleration and d) shows an above view of the horizontal offset capacitors after the displacement in accordance with the present invention.
a) shows a block diagram of an automotive safety system using a computation unit (DSP) to determine which air bags (AB) should be enabled and b) presents a flowchart measuring the capacitance of the offset capacitors in accordance with the present invention.
a) depicts a system of daughter and grand daughter substrates, b) shows a side view of the connect substrate bypassing the I/O circuits and c) presents a capacitor that is fully charged to provide auxiliary power to a daughter substrate to provide energy to power the Coulomb islands in accordance with the present invention.
a) shows an RF front end connected to a dipole antenna, b) presents the construction of a dipole antenna, c) depicts an RF front end connected to a dipole antenna for higher frequencies and d) illustrates the construction of a dipole antenna for higher frequencies in accordance with the present invention.
a) shows an RF front end connected to a Yagi antenna, b) presents the construction of a Yagi antenna, c) depicts an RF front end connected to a patch antenna and d) illustrates the construction of a patch antenna for higher frequencies in accordance with the present invention.
a-b) show the preparation stage of rotating a substrate around a corner of a second substrate, c) presents the substrate rotated less than 90°, d) depicts the substrate rotated 90° and e) illustrates the substrate rotated greater than 90° to place substrate on other side of second substrate in accordance with the present invention.
a) shows cross sectional view of the results of edge processing forming vertical metal sheets, b) presents edge before edge processing, c) depicts the top view of an edge and d) illustrates a side view in accordance with the present invention.
a) depicts an RF front end, antenna substrates and other substrates on a mother substrate and b) illustrates the finished construction of a 3-dimensional antenna in accordance with the present invention.
Several inventions are presented and are described in this specification. All the prior art that has been cited fail to show the inventive techniques including, but not limited to: a moving component that; 1) can be detached from its surroundings; 2) can contain Coulomb islands with opposing charges: 3) can freely move by using Coulomb forces formed by Coulomb charges, and; 4) can adjust the charge of the Coulomb islands in both magnitude and polarity.
a shows a reconfigurable system 1-1 which uses Coulomb force to levitate and position the upper substrates on the top surface of the lower substrate. The lower substrate will be addressed as the mother substrate 1-2 while the upper ones (1-6 through 1-12) will be called the daughter substrates in several descriptions. The substrates can be a die, comprised of dice (chips), MCM (Multi Chip Modules), MEMS (Micro-Electro-Mechanical Systems), wafer bonded components or any of the previous combinations. For instance, a memory substrate (or die) has two surfaces (a top and bottom surface) and has four edges, while a third substrate is formed using a wafer bonding process to combine a first and second substrate that are now physically bonded together as one substrate. The third substrate also has a top and bottom surface and has four edges. In addition, once the substrates are fabricated, placed in a system, and levitated the substrate is completely isolated from the remaining portions of the system. Note in this case, some of the daughter substrates can be moved while the mother substrate is rigid or connected to a reference foundation (not shown). In one case, the daughter substrate can turn around the edge of the mother substrate and position itself on the bottom side of the mother substrate. The substrates shown in this description depicts only those components that relate to the idea being conveyed. However, any circuitry, devices or any other components formed by using the technology that fabricated the substrates can also be used to build VLSI systems on that given substrate. The mother substrate 1-2 in this case is a DSP core, although it could be a processor, microcontroller, memory, FPGA, a portion of a MCM, MEMS, or any structure upon which processing steps can be applied to form Coulomb islands or metallic sheets within the mother substrate.
The Coulomb islands can be of a variety of shapes; circular, oval, rectangular or polygon. The Coulomb islands can be perforated or have an ameba shape, for instance, a Coulomb island can be multi-fingered. The daughter substrates are attached and connected to the top surface 1-3 of the mother substrate 1-2. The system 1-1 is currently being used to communicate using a Standard frequency band within the United States as indicated by the incoming 1-13 and outgoing 1-14 electromagnetic radiation carrying voice, data, pictures or video.
While traveling on the road, the user of the system arrives within the domain of a new base station that uses a different frequency range in another Standard frequency band for that region. An automatic sensing unit within the communication device or the user's input is used to command the system 1-1 to reconfigure itself to operate in this different band. To operate in this frequency range, it would be required to replace the Rec-A 1-9, Tran-A 1-8 and Inductor-A 1-11 which were optimum for the prior band with the Rec-B 1-7, Tran-B 1-6 and Inductor-B 1-10 that are optimum for the different band. Replacing the current components with new components offers several advantages at the system level. A few of the advantages are elimination of RF switches which cause loss, reduction of power dissipation (since only a minimum number of devices need to be powered), optimum frequency band optimization (since components that target the desired frequency band are used) and improved quality factor of the inductor. Note that although only one input/output wireless path is illustrated on the mother substrate 1-2, more than one input/output paths can be incorporated into the system 1-1, for example, MIMO (Multi Input—Multi Output) system.
The sequences of steps are outlined in
Several alternatives using reconfiguration are possible. This depends on the distribution of the communication system between the mother and daughter substrates. For example, the mother substrate can contain busses which interconnect a portion of the “A” daughters to the “B” daughters and use reassembly-switch substrates that reconfigure the remaining portion of the interconnect between these two sets of daughters and the mother substrate. Another case is for the mother substrate to contain two communication systems and several sets of daughter substrates. One set of daughters substrates can be used to communicate on one band while another set of daughter chips are being reconfigured to be allowed to operate in a different band. This situation may occur at the boundary between the two different base stations to insure that a communication channel is not lost.
The control unit to perform this operation may be shared with all substrates or the control unit may exist within the mother substrate, within one of the daughter substrates which is not being reconfigured, for example, memory 1-12 or a combination of the two. The control unit has a computation component that determines the current position of the daughter substrates and calculates the sequence of steps required to reconfigure the daughter substrates to achieve the desired configuration.
Sensors located between substrates are used by the control unit to determine the identity, location, vertical position, velocity, and direction of movement of the daughter substrates. One form of the sensors can use capacitive coupling between a levitated daughter chip and the mother substrate to transfer this information. In one case, power does not have to necessarily be dissipated in the daughter substrates using the sensors. The sensor signal enters a first plate of a first capacitor in the mother substrate and is capacitively coupled to the second plate of a first capacitor located in the daughter substrate. Electrically this signal is coupled to a second plate of a second capacitor located in the daughter substrate that in turn is capacitively coupled to a first plate of a second capacitor located in the mother substrate. A sensing unit on the mother substrate can measure the total capacitance of the series connected capacitors. This value can be used to derive several physical parameters of the system 1-1 as will be described in a later section. Besides the sensor, the parallel plates on the daughter and mother substrates can be used to form capacitors. These capacitors can also be used to send/receive data, signals, clocks, etc.
The system 1-1 uses sheets of charge to form Coulomb forces. These non-infinite sheets of charge should be isolated from each other by an oxide or dielectric layer. These sheets of charge are also called Coulomb islands. Then by charging these sheets, the Coulomb force that forms between the sheets can be used to perform operations. The sheets can be charged using one of several techniques: 1) being mechanically probed, either using an external probe, such as a testing probe or a MEMS probe; 2) induced charging: 3) F-N (Fowler-Nordheim) tunneling; 4) ion implantation; or 5) by a combination of the previous possibilities. Note that for the first technique, an opening in the oxide layer will be required to allow the entry of the mechanical probe. This opening should be as small as possible to minimize the exposure of the uncovered surface of the element to the outside environment which can make contact with the surface and alter the amount of stored charge on the element. Otherwise, one of the superior aspects of the Coulomb island is that the charge can be held indefinitely. So once the insulated metallic element is charged, the charge remains and the element can be used over and over again without further dissipation in energy to generate a Coulomb force. For example, the Coulomb force formed between two sheets of charge, one on the mother and one on the daughter, can be used to levitate the daughter substrate indefinitely. The metallic element can be a metal, for example, aluminum, copper, gold, or it could be a doped semiconductor like polysilicon.
Most of the charged elements described in this specification are planar in nature where the plane can be a small segment or “Coulomb island” several micrometers on a side forming a metallic planar surface. In some cases, electron implantation can be used to blanket the entire back surface of a wafer with the same charge. The plane in this case would be a large Coulomb island covering the entire backside of the substrate. Note mat the charge can be deposited by electron implantation as described in U.S. Pat. Nos. 6,841,917 and 7,217,582. Note that once this charge is placed into the substrate, they cannot be easily changed. Thus, this charge is typically non adjustable after this processing step. In this specification, some of the charge elements that will be described will be called Coulomb islands. Some of these Coulomb islands will have a permanent charge or are charged once, others can be adjusted in magnitude even while the island is performing an operation and is completely detached from the mother substrate, some will have sheets parallel to the surface of the mother substrate, and some with sheets parallel to the edge of the mother substrate. The Coulomb islands are used to generate Coulomb forces that can be used to move the daughter substrates.
A cross sectional view along 1-15a is given in
Shown are the daughter substrates from left to right 1-8, 1-91-6 and 1-12. All are in contact with the mother substrate 1-2. Substrates as defined in this specification will contain a portion for foundation, a portion for holding some of the components (devices, interconnects, via, oxide layers, etc.) that form the circuits and possibly a portion holding mechanical components (MEMS, MCM). The substrates have two portions, for example, substrates 1-2 and 1-12 show a foundation portion (1-16a and 1-16b) and a component portion (1-18a and 1-18b), respectively.
The foundation portion supports the component portion and offers: 1) the ability to handle the substrate without fracturing the substrate into pieces during handling; 2) removal of heat; and 3) possibility of conducting the power supply current (for example, U.S. Pat. No. 4,947,228). In some cases, the substrate is abrasively background to reduce the thickness of the substrate, so they; 1) fit into a final packaged portable system: 2) improve heat transfer; 3) increase flexibility; and 4) reducing the height of stacked substrates (for instance, stacked memory). This foundation portion typically has a thickness ranging from ten's of micrometers to 500 micrometers. It can consist of one or more layers of semiconductor material (silicon, III-V, such as GaAs), an oxide layer (SiO2 . . . ), or a combination of the two. In some cases, the foundation portion could also contain devices (such as devices formed in the semiconductor material), their contacts (source/drain, diffused interconnect, etc.), drilled vias and Coulomb islands. One well known substrate is SOI (Silicon On Insulator). The conventional CMOS (Complementary Metal Oxide Semiconductor) process also falls into this category since the CMOS process typically has a foundation and component portions. The silicon substrate could be epitaxial or bulk construction where an epi or a bulk CMOS wafer can be partitioned to have a foundation portion and a component portion. A few possibilities are suggested but are by no way limiting.
The component portion contains the remaining elements that are required to provide electrical activity, mechanical motion, and electrical connectivity to the substrate. The metal interconnect layers in the component portion comprises; their oxide separation layers, vias, plugs, I/O (Input/Output) pads, power busses, electrical contacts, antennas, inductors, Coulomb islands, moveable metallic components (MEMS) and capacitors. A few of these examples are shown as examples in
The component portion would be mechanically polished, for instance using CMP (Chemical-Mechanical Planarization), to planarize the top surface of the substrate. After this step, the Coulomb islands which are formed in the component portion create Coulomb forces between the two surfaces more uniformly as the daughter substrate moves over the top surface of the mother substrate since both surfaces are more planar. In addition, when the Coulomb forces cause the mother and daughter substrates to contact, the planarization also insures that electrical contact can be made.
The electrical contact is formed between the contacts which protrude above the surface of the substrate. This may require another processing step, for example, removing some of the oxide layer from the top surface to expose and form the protrusion of the metal mesa plateau. Also, the post can possibly be plated with gold (Au) or any other non-tarnishing conductive layer. This would allow the mother substrate post to make electrical contact with all daughter metallic pads. This electrical contact will be made by the Coulomb force created between oppositely charged Coulomb islands on juxtaposed substrates. The pattern of the electrical contacts on the daughter substrate that make contact with the mother substrate is called the “footprint.” Note that the footprint located on the mother substrate is the mirror image of the footprint of the mating daughter. Any daughter substrates that can be exchanged need to have at a bare minimum have a portion of a footprint in common. The charged Coulomb islands would be positioned below the existing oxide surface even after the processing step of removing the oxide to create the metal post.
Another possibility is to use MEMS to form mechanical contacts and extrude the contacts from a cavity formed in the substrate. These contacts would be forced out using the generated Coulomb force between Coulomb islands so that electrical contact can be made with a conductive plate on a juxtaposed substrate.
Additional portions can be combined together by using wafer bonding. For instance, the bottom of a first substrate can be wafer bonded to the bottom of a second substrate. This layering sequence would consist of the component, foundation, foundation and component portions. The two component portions would contain signals, interconnect and could contain the charged Coulomb islands.
In addition, a charged Coulomb island can be formed on the backside of the substrate using electron implantation. Thus, either the foundation portion or the component portion can contain charged Coulomb islands.
j illustrates the situation where the system 1-23 levitates several of the daughter substrates as the gap 1-24 shows to prepare them for movement. The Coulomb islands of the daughter substrate were altered from “positive” to “negative” charge. Since the mother and daughter substrates now have “like” charges on the Coulomb islands, the daughter substrates separate and levitate over the mother substrate. Many details of the illustration have been simplified to present one key idea of levitation disregarding the stability of the levitated substrates which will be described later. Note that the separation can be used to detach the daughter substrates from the power grid network in the mother substrate to significantly reduce the leakage current that each of the daughter substrates would have drawn otherwise. This separation can be performed to reduce the parasitic power dissipation of the system when it is in a power down state.
A flowchart 1-25 is depicted in
The Coulomb force is used to detach, levitate, move and reattach the daughter substrates to reconfigure the system. The Coulomb force is formed between at least two charged elements. These elements can consist of charged points, lines, planes, or volume distributions. When the elements are point, charges, the following equation holds:
where Q1 and Q2 are the point charges, ∈0 is the permittivity of free space, ∈r is the relative permittivity of free space, and R12 is the separation between the charges. The ∈r for SiO2 is 3.9 while air is 1.0.
The Coulomb forces are linear and the total force due to three point charges (Q1, Q2 and Q3) on a reference charge Qr is the sum of the forces due to the three point, charges on the reference charge. The ar1, ar2 and ar3 are unit vectors and Rr1, Rr2 and Rr2 are distances from the reference charge to the other charges in the Cartesian coordinate system. The variables in front of the unit vectors determine the magnitude and sign of the forces:
Since each unit vector can be comprised of an x, y and z components, each of these three components can be determined separately from Equ. 2.
where ρs is the surface charge density, r is the radius of the ring with a width dr, and θ is the angle between the z-axis and the side h. This can be simplified to
where φ is the displaced angle measured from a point on the z-axis to the edge of the disk so is a function of z. For instance, a φ of 90° would be an infinite plane while a φ of 45° would be the case where the distance above the circular sheet of charge equals the radius of the circular sheet (where d=r in
b illustrates on overlapping view 2-3a of two Coulomb islands 2-4z and 2-5a. The islands are metallic and have a radius of r and are separated from each other by the distance of h. Each of these islands can be formed on separate substrates. If both islands are charged, a force F will be exerted against the other. Assume that the Cartesian coordinate system of
where ρsr is the surface charge density of the island 2-4z located at (0, 0, d).
Substrates can have rectangular outlines with various aspect ratios and side dimensions that ranges from a fraction of a millimeter to over a centimeter.
In the graph of 2-6, the right vertical axis provides the voltage necessary to generate a force corresponding to the points 2-7 and 2-8. The islands are positioned as indicated in
In order to generate the forces associated with the points 2-7 and 2-8, the potential of each island is indicated as voltage. As the magnitude of the potential decreases, the charge for a given C also decreases. Equ. 6 was used to determine that the voltage 74 and 220 volts are required for one pair of Coulomb islands to generate the force 10−4 and 10−3 newtons, respectively.
The force has been estimated using only one pair of Coulomb islands and it has been assumed that the entire electric field is used to generate this force. Thus, by reducing the thickness of the substrate and thereby decreasing its weight by an order of magnitude, the required potential can be decreased almost three times. This has a big impact on several issues, some are: 1) lower voltages stress the parasitic diode junctions of the substrate less: 2) lower voltages reduce the stress the gate, drain and source of the devices on the substrate; and 3) generating lower voltages will drop the power dissipation. Some of the electric field lines of the Coulomb island in a conventional process without any special considerations will terminate back into the substrate and reduce the Coulomb force between the two substrates. The thickness of the component section of a substrate is less than 10 micrometers (each metal/oxide layer consumes about 1.5 to 2 micrometers) so some of the force will be lost in the substrate unless special modifications are made, for example, the use of Faraday shields. Oxide substrates also help to deduce the loss. When substrates are levitated over the mother substrate, a minimum distance of separation needs to be determined. This helps in several ways: 1) a smaller distance of separation requires less voltage which in turn dissipates less power; 2) a lower voltage reduces the stress of materials due to high electric fields; and 3) as the daughter substrate decreases in area, the ability to maintain the daughter substrate stable at greater distances of separation becomes more difficult. If each of the surfaces are planar to within ±1 micrometer over a large area, then a separation of slightly more than 4 micrometers should be a comfortable distance between these two large area substrates. However, the amount of required separation between the substrates may need to be evaluated for each daughter substrate.
Several of the special conditions include layout and processing techniques: 1) the introduction of a Faraday shield as discussed later helps to prevent some of these electric field lines from terminating back unto the substrate; 2) any unrelated metallic regions near the islands should be placed further away from the islands; and 3) any heavily doped substrate elements that can terminate these lines can be etched away to remove their presence if possible. SOI (Silicon On Insulator) is a good candidate to reduce the lines terminating on the substrate for the third point mentioned above.
Although one pair of islands can generate the force necessary to overcome the gravitational force, applying the force to a 1 cm2 substrate would require careful placement of the pair of islands and careful application of the force to lift the substrate. Besides, the high values of voltages that were determined earlier would cause a voltage breakdown to occur in the air between the Coulomb islands. Another feature of this invention is the ability to place multiple pairs of Coulomb islands over the surface of the substrate. The spreading of the pairs of Coulomb islands over the surface of the substrate has several benefits: 1) the force can be evenly distributed to lift the substrate equally and more controllably; 2) the force that each pair of islands must generate is the total force divided by n, where n is the number of pairs of islands; 3) since the force per island decreases, the required voltage to generate this force also decreases, which reduces the voltage stress that is applied to materials in the substrate even further; 4) with a large number of pairs of islands, various combinations of potential variations applied to and among them allow a myriad of manipulations available to the levitated substrate; and 5) the stability of controlling the levitated substrate becomes easier since the forces are spread over a larger area.
The voltage stress involves the various semiconductor diode junctions, oxide and air breakdown concerns. Diodes can breakdown when a maximum reverse voltage is applied across the junction. The source/drain regions of an MOS device, the emitter/base/drain junctions of a BJT, and parasitic diode formed during manufacturing are examples of diodes. Similarly, thin oxides as formed between the gate and channel of an MOS device have a breakdown voltage. As the number of island pairs increases, the voltage required to generate the net Coulomb force decreases; thereby, reducing the voltage stress.
An example is described to explain how the voltage that is applied to a multiple of islands can be decreased as the number n of island pairs increases. In
d(1) reproduces
e depicts a substrate 2-21 with a foundation portion 2-2 supporting the component portion 2-4 and the division between them 2-22. A coulomb island 2-23 is located in 2-4. The island 2-23 is charged positively 2-25. Negative charges or impurities 2-24 can attach to the surface of a substrate in an uncontrolled environment. This condition would attempt to neutralize the benefit of fabricating a coulomb island since the electric field intensity formed outside of the substrate is reduced. A hermetically sealed package and better passivation procedures can be used to reduce this concern.
f and
a reveals a cross section view of a substrate 3-1 containing a Coulomb island 3-5 in the component portion 2-4 with an access opening 3-2 for a probe. The top surface 3-3 may be covered with an oxide layer and a pacification layer 3-4. The Coulomb island 3-5 should be placed as close as possible to the surface 3-3 and as far as possible from any unassociated metallic conductors in the region 3-6. It is desirable to have the electric field intensity lines exit the surface 3-3. This would provide greater control of the levitation process if the electric field intensity was prevented from being terminated in the substrate. If not stated explicitly, numbers (e.g., 2-2) which were identified earlier carry the same meaning.
b shows 3-7 and the formation of a positive 3-10 and negative 3-11 charges forming on the top and bottom of the Coulomb island 3-5, respectively. By bringing a negatively charged sheet 3-9 in an external plate 3-8 close to the Coulomb island 3-5, induced charging causes the charge distribution on the coulomb island to have a positive sheet 3-10 adjacent to the plate 3-8 and a negative sheet 3-11 formed on its opposing side. Note that the total charge on the Coulomb island 3-5 is currently neutral. Furthermore, for the quasi-static case, the electric field intensity inside the Coulomb island 3-5 is zero and all induced charges move to the surface of the Coulomb island 3-5. The charge distribution is shown to be evenly distributed; however, the shape of the metallic sheet can cause some of the changes to group at the corners and create an uneven distribution. To simplify the discussion, an even distribution over the surface was assumed. Furthermore, note that the positively induced charge of 3-10 formed in the Coulomb island 3-5 now attracts the negatively charged sheet 3-9 in the external plate 3-8. This is known as the induced force.
The next step is to remove the negative charge from the coulomb island 3-5.
Once the plate 3-8 is removed, as illustrated in
The cross sectional view 4-1 in
c illustrates the case 4-8 where the voltage potential 4-4a which is positive is applied to the plate 4-2. A sheet of positive charge 4-9 forms on the plate 4-2. The positive potential on the plate 4-2 causes the electric field intensity 3-19 to increase. As before by adjusting the magnitude of the voltage potential 4-4a, the charge distribution 3-9c in
a shows a cross sectional view 5-1 of a Coulomb island 5-8 with a Faraday shield 5-7, separated by an oxide layer 5-8a. An oxide layer 5-8b is beneath Faraday shield 5-7. Two small openings 5-3 and 5-4 in the oxide allow both plates to be mechanically probed. Since the Faraday shield 5-7 is further below the surface 5-2, a via 5-6 and metal plug 5-5 form the contact and provides an ohmic path to the probe point 5-4. One of the advantages of probing the metallic plate is that once the probe establishes a charge on the plate, the leakage resistive path is very high once the probe is pulled away allowing the island or shield to maintain the charge for a long time. This probe can be an external probe (test-like) or an internal one (formed by a MEMS structure). However, if semiconductor switches are used to deposit charges onto the metallic plates, the device provide a leakage path and will discharge the plate in a shorter amount of time. In this case, the plate would have to be periodically re-charged at specified intervals. On the other hand, in the case of the external probes, the Coulomb island and Faraday shield can be charged during the testing of the device at wafer level. Once the wafer is sawed into individual substrates (dice) these substrates using a pick and place tool can be placed on a mother substrate which has its Coulomb island and Faraday shield similarly charged. The Coulomb forces developed between the Coulomb islands on the mother and individual substrates can be used to hold the substrates together. The next step would be to prepare these components for package assembly. Then, once the packaged device is complete, the daughter substrates can be reconfigured into a desired system.
b shows a cross sectional view 5-9 of a probe 5-10 applying a negative voltage 4-4 to the Coulomb island 5-8. The negative voltage causes charge to form at the surface as the sheets 5-13 and 5-14. Note that in reality the charge covers all sides of the island to reach an equilibrium condition although only the top and bottom of the island have been discussed to simplify the explanation. The lower sheet of charge 5-14 causes the shield 5-7 to build an induced charge of a positive sheet 5-11 and a negative sheet 5-12 as shown.
c shows a cross sectional view 5-15 of a probe 5-10 applying the negative voltage 4-4 to the Faraday shield 5-7 through the opening 5-4. The potential can be adjusted to form negative sheets of charge 5-16 and 5-12 on the surface of the shield 5-7 and a negative sheet of charge 5-17 on the surface of the island 5-8.
e shows a cross sectional view 5-19 of a negative voltage supply 4-4 applying the negative voltage 4-4 through the switch 4-5. The potential can be adjusted to form negative sheets of charge 5-13 and 5-14 on the surface of the island 5-8. An induced positive charge 5-11 is formed on the surface of the shield 5-7 and a corresponding negative charge 5-12 on the opposite side. As in
Since the island and shield in
a illustrates a prior art FAMOS (Floating Gate Avalanche-injection MOS Memory) device 6-1. The foundation portion 2-2 supporting the component portion 2-4 is shown. The foundation portion holds the source 6-3 drain 6-5 and the channel of the device (not shown). The component portion 2-4 has the oxide layers with thicknesses 6-7 and 6-4 that isolate the floating gate 6-6 with a height 6-8. A view from the top is indicated by the arrow 6-2.
b depicts the top view 6-2 of the source 6-3 and drain 6-5 along with the floating gate 6-6. The floating gate 6-6 in this device is completely surrounded by oxide; thus, the gate is isolated from the remainder of the device 6-1. The opening to the source/drain regions are formed by the contact openings 6-9. F-N (Fowler-Nordheim) tunneling is used to charge the floating gate 6-6 and since the floating gate 6-6 is insulated, the charge can be held indefinitely. This is known as a non-volatile device since the charge can be held even after the power is removed from the substrate. This is another way of charging the insulated sheet; however, the sheet or the floating gate 6-6, in this case, is close to the substrate and can have a large area. Thus, the electric field intensity would mostly exist mostly in the gap between the floating gate 6-6 and the channel of the device (within the thickness 6-7).
As shown in
A cross sectional view 6-22 of the 2-D view with perspective 6-10 is illustrated in
The Faraday shield 6-29 has been added in the cross sectional view 6-25 as indicated in
a depicts a prior art SAMOS device 7-1. This is very similar to the FAMOS device with the exception that an additional gate 7-5 has been stacked over the floating gate 6-6. These devices are also known as a EEPROM (Electrically Erasable Programmable Read Only Memory). The gate 7-5 is called the control gate and is used to enable the erasure and programming of the non-volatile device. The control gate is connected to a voltage source and is separated from the lower gate by the distance 7-3 and is separated from the foundation by the distance 7-2. The thickness 7-4 of the control gate 7-5 is shown. The arrow 7-6 indicates the view given in
A cross sectional view of the SAMOS device is given in
In the cross sectional view 7-11 given in
e illustrates the cross sectional view 7-14 where the Coulomb island being charged positively by the device with the drain 7-15 which energizes holes in the channel and injects them into the floating gate 6-6. Finally, the cross sectional view 7-16 shows the introduction of a Faraday shield 7-12 that is charged positively by the potential supply 6-28. As before, the device associated with the drains 6-5 and 7-15 can be different devices that perform different F-N tunneling capabilities (i.e., electron charging, hole charging, discharging electrons, discharging holes).
Wafer bonding can be used to create various substrate structures.
The cross section view 9-1 in
b illustrates the cross sectional view 9-9 where the charge of the top island 9-8 has been changed to a negative charge. Now the two islands repel one another as depicted by the increased displacement of the distance 9-10. In addition, the electric field intensity 9-12 lines terminate on the negative charge in both islands and arrive from outside both substrates 9-2 and 9-3. An assumption is made here that the remaining portions of the substrate do not contain charges. This is an over simplification, since the substrates as shown would contain some positive charges such that some of the lines of the electric field intensity would start from them and terminate on some of the negative charges within either island. The displacement 9-11 between the substrates in that case would be less than what is illustrated. A way of recovering some of the displacement 9-11 would be to introduce Faraday shields into each substrate.
a illustrates the cross section image 10-1 of two substrates (10-17 and 10-18). The top substrate 10-17 has multiple Coulomb islands 10-2 through 10-8 while the lower substrate 10-18 has the Coulomb islands 10-9 through 10-15. This is the first presentation of multiple islands on one substrate. These islands help to explain how the substrates can be repelled from one another yet remain in levitation state. For example, the islands 10-2, 10-310-7 and 10-8 from the top substrate 10-17 are repelled from the underlying islands 10-9, 10-10, 10-14 and 10-15 within the lower substrate 10-18, respectively, since they have a like charge. However, the inner islands 10-4 through 10-6 of substrate 10-17 attract the islands 10-11 through 10-13 of substrate 10-18 since their charges are opposite. The charges on the islands 10-4 through 10-6 have an increased positive charge as indicated by the double “plus” signs. These charge distributions on the islands causes the two substrates to be separated by the distance 10-16.
In
What has not been shown is how the substrates remain in a stable position once they are separated and levitated. There are sensors on the substrates that can measure their distance at several points of the surface of the substrate and provide feedback information to a control unit that can use this information to adjust the amount of charge in the islands. Doing so allows the substrate to remain levitated and in equilibrium. This daughter substrate control unit can be located either in the daughter substrate, in the mother substrate, or distributed between both. This forms a feedback system which dynamically corrects for and adjusts the position of the two substrates to each other. The sensors can be capacitive in nature and can be used to measure distance, acceleration, velocity, position or identity of each substrate. An additional control unit that, orchestrates the movement of all daughter substrates with respect to one another can also be used. The additional control unit can also be in communication with the daughter control unit. In addition, the sensors can also be mechanical in nature as well. A MEMS structure can be used for an accelerometer and can be mounted on a daughter substrate to monitor its acceleration.
The cross section 11-1 illustrated in
The cross section 11-26 illustrated in
c shows a cross sectional view 11-28 where a third variation of using different substrates are depicted. The upper mother substrate 11-31 and the upper daughter substrate 11-33 now has a blanket electron implantation generating negatively charged islands 11-30 and 11-32 near the surface of each substrate. The electrons are injected into an oxide layer with a low energy implant such that the charge is close to the surface. The upper daughter substrate can be an oxide and is wafer bonded to the lower daughter substrate 11-4 at the interface 11-29. It is also possible to grow an oxide onto the back side of the 11-4 substrate. In this case, the electrons can be implanted directly into this oxide layer eliminating the need for bonding the upper substrate 11-33 to the lower substrate 11-4. The inner daughter substrate can again be levitated.
The Coulomb forces, holding the two substrates together at the posts, can be varied according to a program stored in a control unit that can be located in one or more of the substrates. A sequence can cause the Coulomb force to force a lateral movement (shearing force) of one of the substrates. This will cause the surface of the connected metal posts to nib each other so that any oxide layer formed on the connected surfaces of the posts undergoes abrasion and/or scraping which exposes the underlying metal. An improved metallic connection can then be formed between the two adjoining posts once the underlying metal is exposed. The shearing force can also be used to disconnect the substrates from each other. In addition, a MEMS ultrasonic transducer can be enabled to introduce vibrations to aid the shearing force being applied to the posts.
e illustrates another cross section view 2-16 which contains MEMS devices 12-20 and 12-19 in the upper substrate 12-18 and the lower substrate 12-17, respectively. Two of the Coulomb islands 12-21 and 12-22 are shown to be positive. In
A solder bump connection is also depicted in
Of course, vias that penetrate the entire substrate can be used in the first two examples. In addition, for the solder bump case, the substrates could also be arranged top to back as well.
A cross sectional view 13-1 of a packaged levitating device is illustrated in
In the view 13-9 given in
a illustrates a package 14-1 that contains an adjustable capacitor formed between two substrates. The top of the package 14-2 does not contain any islands. The daughter substrate 14-6 is levitated using both like (14-7 and 14-12) and opposing (14-8 and 14-13) charged islands. Similar conditions hold for the remaining islands. The first repels while the second attracts; if the force can be balanced then the substrate 14-6 can be held in a levitated state. The distance of separation 14-3 is indicated. In addition, a bonding wire is shown to connect an I/O pad to the package pad.
The capacitor consists of parallel metallic plates 14-9, 14-14 and 14-15. The metallic plate 14-9 located in the daughter substrate has a larger area and overlaps the areas of the metal plates 14-14 and 14-15 which are located in the mother substrate 14-4. A signal can be applied to the plate 14-14 then capacitively coupled to the plate 14-9. This signal then returns capacitively to the lower plate 14-15. Thus, this path consists of two capacitor's in series and the value of these capacitors depends on the distance of separation 14-3. Such a capacitor can be used to measure the distance using electrical circuit techniques. For example, a capacitive bridge circuit can be formed using the series capacitors as one of the bridge elements. By measuring the output of the comparator connected to the bridge circuit, the relative change in distance can be measured. Furthermore, the plate 14-9 can be tapped electrically and either extract the signal at this point on the substance 14-6 or inject a signal into the plate. This capacitor exists when the daughter is in contact with or being levitated above the substrate. As the daughter substrate moves away from the mother substrate the capacitance would decrease in magnitude.
Another possible use for these capacitors is to create an adjustable LC tank circuit 14-16. Such a circuit is illustrated in
Another use is to measure the frequency of operation of the tank circuit 14-16, use a lookup table, match the measured frequency to an entry in the table, and extract the value of the distance of separation. Such a circuit can be used to measure this distance and be used to apply corrective adjustments to the Coulomb islands so that the separation is controlled. This is another way of measuring the separation so that the daughter substrate can be maintained in a controlled state of levitation.
In the package 14-18 of
a illustrates a cross sectional view 15-1 of a package where the daughter substrate 15-2 contains an inductor 15-4. If the foundation portion is composed of any low resistivity material (e.g., p+-epi, highly doped materials, metallic structures, etc.), the substrate can be preferably etched to remove this section as indicated by the cut 15-5. In SOI (Silicon On Insulator), the loss is less severe since the foundation portion is an oxide. The removal of this material decreases the losses of the inductor and improves the “Q” of the inductor. The daughter substrate is separated by the distance 14-3. The volume around the inductor 15-4 is air which would reduce the eddy current loss in the substrate that is typically associated with this volume (for example see U.S. Pat. No. 7,250,826 and U.S. Appl. 2007018739). The self-eddy current loss occurring within the inductor itself can be decreased in one example as indicated in U.S. Appl. 20070176704. As before, a bonding wire 14-11 (only one is shown) is used to connect the I/O pads of the mother substrate 15-3 to the a bonding pad of the package. A top view 15-4a of one type of inductor layout is illustrates in
In
One example of wire bonding is illustrated in
The way the daughter substrate is moved across the surface is provided in the following figures. A 2-D representation will be used to describe the basic concepts of lifting, moving, and chopping while a 2-D with perspective will be used to give a better understanding by visualizing how the substrates slide over the mother substrate. The Coulomb islands are shown to be in a regular or arrayed pattern; however, this is not a requirement. For instance, instead of covering the entire substrate with an array of islands, strips of islands can be formed that bear a relationship to the size of the daughter substrates (either directly or in multiples). Doing so would free up the remaining area for signal, clock and power bussing.
One example of strips of islands is given in
b illustrates the view 17-14 where the islands 17-8 and 17-9 have been given a charge. The right edge of the daughter substrate is marked by the line 17-13 and the substrates are still in contact. The substrate 17-2 has a gravitational force 17-15 and the unit vector forces 17-16 through 17-21 are indicated. The magnitude of these forces are not shown but can be determined by knowing the size of the islands, their distances, and their charges, Equ. 2 can be used to estimate the unit vector forces and components. The forces 17-16 and 17-18 are downward since each pair of Coulomb islands: 17-4 and 17-7, 17-5 and 17-10 have an attractive force and hold the two substrates together. The forces 17-17 and 17-19 are repulsive and are due to the two pairs of same charged islands: 17-6 and 17-4, 17-9 and 17-5. In addition, the forces 17-20 and 17-21 are attractive and are due to the two pairs of oppositely charged islands: 17-4 and 17-8, 17-5 and 17-11. Note that the summation of the unit force vectors indicate that, there will be a net force in the positive x-direction.
e shows the charge on the islands 17-7, 17-9, 17-10 and 17-12 being neutralized. The only forces are the attractive forces 17-20 and 17-21 and the repelling force 17-17. These forces continue moving the substrate in the x-direction and prepare the positioning of the daughter substrate over the mother substrate. Finally, the cross section view 17-29 in
The timing diagrams 17-31 to make the daughter substrate move in the positive x-direction are given in
a illustrates the cross sectional view 18-1 of the case when the daughter substrate 18-3 is moving in the positive y-direction against gravity 18-2. One can appreciate that wafer thinning (such as back grinding) is very beneficial to ease the movement of the daughter substrates since their mass can be reduced. This reduction in mass also can reduce the magnitude of the required voltages necessary to activate the forces associated with the coulomb islands. Thus, the power dissipation of the system can be reduced if the daughter substrates are thinned to reduce their mass.
In the example given, the mother substrate 18-4 generates the forces necessary to move the daughter substrate 18-3 against the force of gravity 18-2. Although there are only two Coulomb islands, 18-5 and 18-6, on the daughter substrate 18-3, the additional placement of islands would offer a benefit in that the movement becomes performed in smaller movements and thereby providing better control. However, only two islands will be used in this description. The mother substrate 18-4 has the Coulomb islands 18-7 through 18-15. The islands 18-7 and 18-10 are positively charged. The island 18-7 generates a repulsive force 18-17, while the island 18-10 generates the repulsive forces 18-16 and 18-22. The arrows indicate the unit vector components of the force. The magnitudes of these forces are not shown. The islands 18-9 and 18-12 through 18-14 are negatively charged. They generate the attractive forces 18-18, and 18-19 through 18-21, respectively. The summation of all the positive y-component forces must exceed the force of gravity 18-2. Also there should be a negative x-component of force that overcomes the suction force and displaces the substrate by the distance 18-23. Once the substrate moves upwards a vertical distance 18-30,
A simplified version of a daughter substrate 19-1 is illustrated in
A minimum energy surface is made by applying potentials in certain sequences to the Coulomb islands. Suppose the daughter substrate is to move in the positive y-direction, then the energy surface surrounding each of the islands on the daughter substrate need to have a minimum energy barrier in the positive y-direction and a larger energy barrier in the three directions of negative y-direction, positive x-direction and negative x-direction. Assume that the islands of the daughter substrate are charged positively. In addition, the islands directly under these islands on the mother substrate (1, 4), (4, 4), (1, 1) and (4, 1) are also charged positively. Thus the daughter is repelled from the surface of the mother substrate. A unit force vector would point from the island of the mother substrate to the juxtaposed island of the daughter substrate (but is not shown). The remaining unit force vectors on the island 19-3 due to the adjacent islands are indicated. Whatever is done in the vicinity of one of the islands of the daughter substrate on the mother substrate is repeated at the other three islands as well; thus, the formation of the minimum energy surface can be made for one of the daughter islands which can then be repeated at the three other islands. The island at (1, 1) is used as the example. The next step is to place a positive charge at the islands forming a semi-circle shape surrounding the island located at (1, 1). These include the islands located at the coordinates (0, 1), (0, 0), (1, 0), (2, 0) and (2, 1). The forces that the island 19-5 would experience are indicated by the direction of the corresponding unit vector forces, in other words, as an example, the force 19-9 on the island 19-5 is shown to exist from the island at (0, 0) of the mother substrate to the island at 19-5 of the daughter substrate. Thus, the semi-circle formed earlier acts as a barrier to prevent the island 19-5 from moving in the negative y-direction and either of the positive or negative x-directions. Thus, this energy barrier is not at a minimum in these directions. However, in the positive y-direction the barrier is less if the charge of the islands at (0, 2), (1,2) and (2, 2) are set to a neutral charge. To enhance the reduction of the barrier further, the islands at (0, 2), (1,2) and (2, 2) can be set to have a negative charge. Now, a force exists to move the island 19-5 in the positive y-direction. Thus, a minimum energy barrier in the positive y-direction was created around the island 19-5 of the daughter substrate 19-1. These forces allow the island 19-5 to be levitated and slide in the positive y-direction. By symmetry, each of the remaining islands of the daughter substrate have a similar energy barrier allowing the entire daughter substrate 19-1 to be easily moved in the positive y-direction. The net force required would be evenly divided between the four islands of the daughter substrate. Each island only has to generate ¼ of the overall force. This can reduce the voltage necessary to charge the islands and can reduce the power dissipation of the system.
To help explain the next figure, some symbols need to be introduced.
d illustrates the placement of the coulomb islands in the mother substrate 20-1. The islands at (2, 1), (5, 1), (5, 4) and (2, 4) are charged positively as indicated by the symbol. A daughter substrate 20-2 is shown in
The process of moving the daughter substrate in the y-direction which was shown earlier is repeated in
The next step is illustrated in the top view 21-3 shown in
A daughter substrate may need to be rotated in place.
c illustrates the top view 22-7 of the charging of the adjacent islands to create the energy barriers appropriate to perform a rotation. By symmetry, as before, only the forces with one corner are explained since the remaining corners are similar in structure, would be charged the same and would therefore behave similarly. The corner associated with the Coulomb island 22-4b that is charged negatively is used to explain the rotation. As mentioned earlier, the island at (5, 5) on the mother substrate is charged positively. The islands at (5, 4) and (6, 5) are charged negatively. The islands at (4, 5), (4, 6) and (5, 6) are charged positively. In addition, the island at (3, 4) is charged negatively to help attract the inner island 22-2b on the daughter substrate. The top view 22-8 in
e illustrates the top view 22-10 with the daughter substrate rotated 45° as indicated by the current location of island 22-4b. The symbols used on the daughter substrate are changing their relative orientation due to the rotation of the daughter substrate. Corrections for the symbols within the daughter substrate are made in
g depicts the top view 22-11 of the position of the daughter substrate after being rotated 90°. The optional step can be used to discharge the islands that are not responsible for holding the two substrates together. The final top level view 22-12 is illustrated in
A Laser Interface System 23-1 (LIS) is illustrated in
b illustrates a flowchart 23-26 to position the laser receiver. The positioning of all the components at a global level was covered in the flowchart 1-25 shown in
c depicts another flowchart 23-38 of a control unit that addresses aligning the V-groove unit to the edge laser. The determination of sequence of movements 23-39 is calculated. For instance, movement in the y-z plane can be calculated. Z is perpendicular to the surface of the substrate. Prepare the feedback system to respond to the changes being made 23-40. This requires the reception of a signal from the fiber which is then send back to the control unit to determine optimum operation. Roughly position the edge laser (flowchart of
A LoC (Lab on a Chip) 24-1 is illustrated in
A cavity is filled with a fluid when the forces due to the mass of the fluid just equal the forces holding the surface together. In this condition, the surface tension can generate two different contact angles (θ1 and θ2) as depicted in
In
Once the contact is made several studies can be carried out. The surfaces of the liquids are now in contact and studies may be conducted on the surface properties of these two liquids to determine if diffusion between the fluids occurs even if the surfaces are not broken. This substrate arrangement offers the ability to study the characteristics of: 1) surface features of the same or different fluids whose surfaces are placed in contact with one another; 2) potentials can be applied to each fluid to study the transfer of charged ion components between the fluids; 3) using a pump, some of the fluid can be extracted then additives can be added to either fluid to see how changing the characteristics of the fluid affects either the solution or the surface properties; 4) using the pump, samples of the fluid can be extracted and analyzed to determine its properties: 5) one substrate can be moved laterally to rub the surfaces together to determine a “coefficient of friction”; and 6) to determine when and if the surfaces breaks and under what force was required to do so.
e provides a flowchart 24-44 for positioning the pipette and dropping samples into cavities. As the pipette gets close to a substrate, capacitances are used to determine their distance and position. The capacitor can be formed between the tip of the pipette and the cavity. The first step is to determine a sequence of movements to place cavities under the pipettes 24-45. Pick the first, recipient 24-46 and determine if recipient is in the right position 24-48. Move recipient until it is positioned correctly 24-49. Determine if the pipette is over the cavity 24-51, if not, position the cavity better 24-52. Otherwise, drop a sample from the pipette into the cavity 24-53. Determine if there are more cavities in recipient 24-54, if there are determine next cavity and go to 24-48 and repeat previous steps, otherwise determine if there are more recipients 24-56, if there are move to next recipient 24-57 and select cavity, place cavity in position 24-48 and repeat previous instructions, otherwise samples are prepared for experiment 24-58.
As the containers are moved, capacitances are used to determine then distance and position.
In some cases of exchange, both the daughter and grand daughter substrates can move simultaneously to make exchanges. This adds complexity to the control of the system since the grand daughter substrate moves with respect to the daughter substrate while the daughter substrate moves with respect to the mother substrate. The path that the grand daughter sweeps out with respect to the mother substrate can be quite complex. However, in some cases, such a path can provide quicker reassembly, lower power dissipation, construction of an unusual design, or some other cost function. The control unit can be programmed to select the appropriate algorithm to perform the required moves for the given cost function.
a depicts an accelerometer 26-1 that can detect a lateral and vertical acceleration or deceleration. The structure comprises a mother substrate 26-4 with capacitor plates (26-5 and 26-6) while the remaining components shown are charged Coulomb islands. The daughter substrate 26-3 with capacitor plates (26-7 and 26-8) while the remaining components shown are charged Coulomb islands. Note that, the lower Coulomb islands in 26-4 can have a different width than those found in 26-3. This will offer the movement of the daughter substrate with: 1) a more controlled height vs. displacement; and 2) offer more elasticity to the movement of the upper substrate since the forces from the lower substrate are spread out over a larger area thereby equalizing the force between the two juxtaposed islands over short distances. A top view 26-9 of the metallic capacitor is depicted in
In
The accelerometer 26-1 in
Other forms of capacitors that are useful to detect acceleration are illustrated in
a depicts a block diagram 28-1 of a movable system (e.g. automobile) with a deceleration device 28-2 which feeds information to a FSM (a DSP 28-3 is shown, but it could be a microcontroller, ASIC, FPGA, microprocessor, etc.) to be processed. The result is applied to the bus 28-5 and is applied to the airbags (AB) 28-4 and determines the appropriate AB's to fire and their firing sequence to minimize bodily injury due to the impact of the crash.
b illustrates the flowchart for an accelerometer which uses the levitated substrate and Coulomb islands as described earlier. Such an accelerometer may be useful in any moving vehicle. Assume the system is at rest, then go to start 28-8, measure the capacitance 28-9 (for example, the capacitance 26-5M and 26-7D) and in a loop continue measuring the capacitance until a change is noted. From the displacement of the daughter substrate determine the lateral (or horizontal) movement 28-11, then determine the direction of the acceleration or deceleration 28-12. Next check if the vertical capacitors have changed 28-13, if so, measure the vertical distances 28-14, then use these values to determine the vertical acceleration or deceleration 28-15, once all data is available report or store the information to the system 28-17.
a depicts a view 29-1 of a two layered system on mother substrate 29-2 containing a daughter and grand daughter layer. The daughter layer comprises: the FPGA 29-14, Microprocessor 29-12, DSP 29-5 and Video Accelerator 29-8; and memory substrates 29-6, 29-16, 29-10 and 29-3. The grand daughter layer comprise: the connect substrates 29-13, 29-11, 29-9, 29-4 and 29-17; and the capacitance substrates 29-15 and 29-7. The connect substrates can have many uses; one is to bypass the output/input buffers of a path connecting the core of one substrate with another, another is to electrically connect metal segments of adjacent substrates together.
As RF frequencies continue to increase in carrier frequency, the wavelength continues to decrease. The antenna used to capture this signal is of finite size and has a relationship to the wavelength. When the antenna dimensions are as follows:
ka<1 (7)
where
“a” is the radius a sphere enclosing the antenna, and λ is the wavelength. Then, the antenna is an Electrically Small Antenna (ESA) if the condition in Equ. 7 is satisfied. The ESA determines the impedance bandwidth of an antenna and the Q of the antenna. These antennas will have a lower Q.
Various frequencies are allowed for communications. The Personal Communication System (PCS) operates at 1900 MHz, Global Positioning Satellite (GPS) is at 1,500 MHz, and GSM (Global System for Mobile communications) at 900 MHz. The wavelength ranges from 16 to 33 centimeters. Forming an antenna on a substrate with a side dimension of 1 cm and using Equ. 7 would indicate that the antenna would be an ESA.
The FCC (Federal Communications Commission) has adopted rules for 71-76 GHz, 81-86 GHz and 92-95 GHz bands. The wavelength of the earner would be approximately range from 3000 to 4000 micrometers. Depending on the final antenna design and layout, the ESA conditions are not as prevalent as they were for the PCS, GPS and GSM systems. An antenna has an optimal performance when the antenna is designed for a given frequency. As the carrier frequency changes, the transfer power of the captured signal in the antenna to the RF frond end decreases. An ideal way of overcoming this issue is to reconfigure the dimensions of the antenna so that they operate as a function of the carrier frequency. Another way is to reconfigure the dimensions of the antenna so that they operate within the center of each of the three FCC bands. The dimensions of the antenna can be redesigned on the fly using Coulomb islands. For instance,
b illustrates a Reconfigurable Antenna on a Substrate (RAS) 30-5. The mother substrate 30-6 carries a portion of the radio circuitry (RF Front End 30-4) closest to the antenna mat is concerned with receiving/transmitting signals from/to the antenna, respectively. In addition, there are a multitude of substrates with a variety of shapes in the metallic layers that can be reconfigured as antennas. The individual antenna substrates currently appear to be similar but can be of any required size and shape to satisfy the designs goals. Although, a dipole will be described, this invention can be used to modify the dimensions of: a) a patch antenna to λ/2 and control the height of the patch above a ground plane on the mother substrate, b) MIMO (Multiple-input Multiple-output) antennas, c) Yagi antenna, and 4) reflector based antennas to name a few. The RF Front End 30-4 can be connected through the mother substrate 30-6 to the antenna substrates 30-7 and 30-11 which form one end of the dipole antennas 30-2 and 30-3. The antenna substrates 30-7 through 30-10 are connected to each other to form the leg 30-2 of the dipole, while the antenna substrates 30-11 through 30-14 form the leg 30-3 of the dipole.
The antenna substrate can be: 1) connected to the adjacent antenna substrate by using the “connect substrate” discussed in
c illustrates the case where the carrier frequency has increased thereby requiring the dipole to be shortened. Both legs of the dipole 30-18 and 30-19 need to be decreased in length.
a reveals a Yagi antenna 31-1 connected to the RF front end 31-4. The Yagi antenna has a pair of reflectors 31-2, the active dipole antenna pair 31-3, and the directive antenna 31-5. This antenna system has been re-configured and optimized to operate at a given carrier frequency in
A patch antenna 31-11 connected to an RF front end 31-4 is shown in the block diagram 31-10 in
An issue important to communications is the interception of orthogonal signals. Typically, orthogonal surface planes containing the antenna are beneficial. Reconfigurable techniques can be use to implement antenna on surfaces which are orthogonal to each other. The following diagram helps explain the inventive technique to achieve this capability.
c reveals the net forces applied to the system 32-10 to create a rotation 32-9 of the substrate 32-4. The gravitational force 32-11 must be stabilized and overcome by the forces generated by the induced and island charges. The set of unit vector's forces 32-13 are used to provide torque to the end of the substrate. The grouping of unit vector forces 32-12 help to maintain cohesion of the substrate 32-4 to the substrate 32-5 near the pivot point. The group of unit vector forces 32-14 caused by the induced charges help to pull the substrate 32-4 towards the edge of substrate 32-5, while the vector 32-15 pulls in the same direction.
Induced charges at the edge of the substrate helps to pull the daughter substrate toward the edge of the mother substrate 32-5 as indicated by the unit vector forces 32-14. Induced charges can also be used as an attractive force while the daughter substrate moves over the surface of the mother substrate. This has not been described in detail but the basic concept of induced force can be visualized in
Also in place of the induced charges being formed on the edge of the substrate to help attract the daughter substrate 32-4, edge Coulomb islands can be used to attract the daughter substrate. In addition, a corner substrate can be placed flush with the edge of the substrate 32-5 to provide support, additional Coulomb islands and surface area. More will be stated about the “edge Coulomb island” and the “corner substrate” shortly.
d shows the cross sectional view 32-16 where the substrate 32-4 is positioned orthogonal to the substrate 32-5. To lock the substrate in position, the second island from the top of substrate 32-4 should reverse the negative charge to a positive one. This would cause the unit vector force 32-19 to change from repelling to attractive which would lock the orthogonal substrate in place. The description of how a daughter substrate can be rotated around the edge of a mother substrate has been given.
However, if the substrate was desired to be moved to the bottom of the substrate 32-5 then the repelling charge that generates the unit vector forces 32-19 can be used to continue the rotation 32-9 around the substrate 32-5.
An aspect that, has not been used previously in the design of systems is using the edge of the substrate to perform connectivity functions.
There are several differences between the I/O connection and the I/O pad, however: 1) the I/O pad is parallel to the surface of the substrate while the I/O connection is perpendicular to the surface; 2) a single I/O connection can have minimum dimension of in the range of one micrometer while a conventional I/O pad has a minimum dimension of 50 to 100 micrometers; thus, the packing density of the I/O connection is orders of magnitude greater than the conventional I/O pad; and 3) current can flow horizontal with respect to the substrate in I/O connection while the current flows vertically in the I/O pad. The electrical contacts 33-5 is also known as the I/O port, and serves in part the same function as an I/O pad that is found on the surface of a conventional substrate which is to allow the entrance and egress of signals and power.
There is at least one difference between the I/O port and the I/O pad, however: a single I/O port can have minimum dimension in the range of one micrometer while a conventional I/O pad has a minimum dimension of 50 to 100 micrometers; thus, the packing density of the I/O port can be orders of magnitude greater than the conventional I/O pad. The minimum dimensions of 50 to 100 micrometers for an I/O pad is derived the mechanical tolerances of connecting the substrates in a package by using solder bumps connection or wire bonding procedures, respectively.
Note that, as done previously, any electrical connections to the metallic stacks, the Coulomb islands or the electrical contacts are not shown and have been removed to simplify the diagram. It should be understood that the electrical connections can be capacitive, resistive, inductive or any combination of these. The substrate 33-13 could be formed by wafer bonding two substrates back to back, although as described earlier, there are many equivalent alternatives possible.
The top view 33-14 indicated in
Note several conditions with these vertical “planes”: 1) the metal and via layers 33-6 through 33-12 and the metal and via layers 33-6 through 33-10 are used to form the three independent vertical planar metallic sheets (of course, it is not necessary to use all metal trace/via layers); 2) the position of the metal to the edge of the substrate is determined by the layout (positioning) of the metal layers and CAD (Computer Aided Design) layout tools can be used to automatically place these layers; 3) the connectivity can be either capacitive, resistive or inductive; and 4) they can be used as a edge Coulomb island, an edge contact or one of the plates of an edge capacitor.
a depicts the top view 34-1 of two substrates 34-2 and 34-3 connected at then edges. The attractive force generated by the two pair of edge Coulomb islands: 34-6 and 34-7: and 34-8 and 34-10 are used to hold the two substrates together along their edges. The metal extensions 34-4 and 34-5 or edge contacts are forced into each other at the common interface 34-15 and can be used as an electrical contact. The right substrate 34-3 has an electrical contact 34-16 that exits the bottom of the substrate 34-3. In addition, the metal trace 34-17 connects the electrical contact 34-4 to the metal extension 34-18. The regions labeled 34-9 can be used as electrical contacts or as Coulomb islands.
Orthogonal antenna configurations are an important capability for complex antenna systems. An antenna picks up signals from a transmitter typically after the signals have been reflected from various surfaces. Thus, the complete incoming signal composed of signals that are delayed, polarized in different orientations, arriving from different directions, and of course decreased in magnitude. The difficulty is the development of nulls in the radio spectrum that decreases the intensity of the information. If an antenna with a given polarization is placed right at this point then the signal intensity can be lost. The other two polarizations associated with this radio spectrum may have signal intensity at tins point; but the antenna unfortunately is not equipped to capture these signals. Ideally, the complete antennas should have three antennas that are orthogonal to each other. Several reasons have prevented this from being standard equipment: 1) the cost of manufacturing the equipment; 2) the volume displaced to enable these antennas (covering three orthogonal directions); and 3) the need for three antenna ports on the front end or the ability to easily switch between the three antennas. As carrier frequencies increase, the wavelength of the carrier decreases. At 75 GHz, the wavelength of the carrier is comparable to the dimensions of the substrate allowing the formation of the antennas on the substrate. However, the invention is not limited to these high frequencies. At lower frequencies: PCS, GPS and GSM, Equ.7 indicates that the condition will be met and the antenna would be an ESA making the design of the communication system with regards to the front end more difficult.
MIMO can benefit from this technique as well since MIMO operates on a single signal that is sent on (n) multiple antennas such that each of the (n) signals received have traveled different paths. MIMO radio use n-antennas simultaneously to extract the n-signals and combine the n-signal energies that are related.
An orthogonal antenna system can intercept signals in very diverse polarizations. A three way orthogonal antenna can he designed to capture information from three different planes, which allows this technique the ability to capture more energy.
b shows the system 35-10 after these antennas were rotated 90° around the edge of the mother substrate 35-2 and held in place as described in the previous diagrams given in
The antennas: 35-4 and 35-3; 35-5 and 35-6; and 35-7 and 35-8 can be flipped back onto the mother substrate and can be reconfigured for a different carrier frequency. Once the replaced substrates are reconfigured, the Coulomb force formed at the edge of the substrate can be used to hold these smaller substrates together to form the larger substrates: 35-4 and 35-3; 35-5 and 35-6; and 35-7 and 33-8. Then, the latter two pairs can be flipped 90 with respect to the mother substrate and mounted on the edge of the mother substrate again.
The inner substrates 36-3, 36-9 and 36-5 form several layers of substrates. One of the problems of vertical stacking of substrates is the difficulty of sending power and signals between the various layers. The two side substrates 36-2 and 36-4 illustrate how the power and signals can transfer between the various layers of the substrates. These have the metallic traces inside the component portion 2-4 of the substrate are indicated by the dotted ellipses 36-6 and 36-7. The substrate 36-2 connects the lower substrate of 36-5 to the top most substrate 36-3, while the substrate 36-4 connects the lower substrate of 36-5 to the upper substrate of 36-5.
The substrates are moved into and held in position by using Coulomb forces generated by the Coulomb islands. The process of moving and holding the substrates into position has been covered in previous paragraphs. For example, the Coulomb islands 36-12 and 36-17 attract the islands 36-14 and 36-8, respectively. Note that the Coulomb island 36-12 is parallel to the top surface of the substrate 36-2; so this island can also be called a “surface Coulomb island.” The Coulomb island 36-14 is parallel to the edge of the substrate 36-3; so this island can also be called a “edge Coulomb island.” Thus, a top Coulomb island 36-12 generates a top Coulomb force and is attracted to an edge Coulomb island 36-14 that generates an edge Coulomb force and the contacts 36-13 are made. The substrate 36-4 is held to the substrate 36-5 by the lower pair of Coulomb islands 36-19 and 36-21 and the upper pair (not labeled) to make the upper contact. The substrate 36-3 has the connection 36-11 to send signals between adjacent substrates in the stack. The dotted oval region 36-10 indicates that the trace on this level may have made an orthogonal turn.
a-c reveals how daughter substrates become grand daughter substrates by using edge and surface Coulomb forces. A system 37-1 consists of a mother substrate 37-2 with two daughter substrates 37-3 and 37-4. Each of the daughter substrates can comprise one or more individual substrates. For instance, the substrate 37-3 contains 9 individual substrates while the substrate 37-4 contains three. The substrates 37-3 and 37-4 may utilize both surface and edge Coulomb islands. The individual substrates in the daughter substrate 37-3 are held together by edge Coulomb forces; the daughter substrate moves on the surface of the mother substrate by using surface Coulomb forces of at least one of the individual substrates. This is evident by observing that the movement of the daughter substrate 37-3 in the direction 37-5 requires that the moving substrate remain cohesive; the edge Coulomb forces provide this function. However, the substrate 37-3 can release the edge Coulomb forces and move each of the individual substrates separately and then reassemble them at the destination. This would be useful when the surface of the mother substrate is crowded with many substrates and only narrow passageways exist that are slightly larger than an individual substrate.
b illustrates a “corner substrate” 37-6 can be placed on the opposite surface of the mother substrate to increase the effective height of the edge. As the daughter substrate 37-3 is being moved in the direction 37-5, the substrate 37-4 is moved until it overhangs the edge of the mother substrate 37-2. When the center of mass of the substrate 37-4 passes beyond the edge of the mother substrate 37-2, the edge Coulomb forces of the mother substrate 37-2 in combination with the edge Coulomb forces of the corner substrate 37-6 and the bottom surface Coulomb forces of the substrate 37-4 attract the two substrates together. Meanwhile the bottom surface Coulomb forces of the substrate 37-4 juxtaposed to the top surface of the mother substrate 37-2 repel each other. This causes the substrate 37-4 to rotate (see arrow) clockwise around the edge of the mother substrate 37-2. After the flip, the surface of the substrate 37-4 is parallel to the edge of the mother substrate 37-2. The edge Coulomb forces of the mother substrate 37-2 in combination with the edge Coulomb forces of the corner substrate 37-6 help hold the bottom surface Coulomb forces of the substrate 37-4 in place. Then, as shown in
In addition, more corner substrate can be stacked on the first corner substrate 37-6 to provide a wider edge. These corner substrates provide several features: 1) the area of the edge of the mother substrate is increased allowing more Coulomb islands to help stop and hold the substrate that was rotated; 2) vertical movement of the rotated substrate is improved since there are more Coulomb islands to create more Coulomb forces; 3) additional metallic contacts can become available to power up the rotated substrate; and 4) the corner substrate can move laterally to tilt the angle of the rotated substrate 37-4 away from 90°.
The stacking of the substrates of making daughter substrates into grand daughter substrates then great grand daughter substrates can continue for many levels.
The stacked substrate 38-1 is illustrated in
A dense package or stacked substrate such as that shown in 38-1 can be assembled into a structure as shown in
f illustrates the antenna given in
a depicts a substrate stack 39-1 where each layer of the stack has an inductor 39-2 through 39-4 inside the substrate. The middle substrate 39-6 is placed in between top 39-5 and bottom 39-7 substrate. The distances 39-9 and 39-10 indicate the relative position of the middle substrate to the two other substrates. The top view of the metallic substrate 39-8 that forms part of the middle substrate 39-6 is shown in
Finally, it is understood that, the above description are only illustrative of the principle of the current invention. It is understood that the various embodiments of the invention, although different, are not mutually exclusive. In accordance with these principles, those skilled in the art may devise numerous modifications without departing from the spirit and scope of the invention. For example, the individual substrates held together by edge Coulomb forces may be comprised substrates using various materials fabricated in a variety of technologies. Also, the Coulomb forces can hold substrates together even after the power supply has been disconnected from the system. This occurs if the islands are the non-volatile type since these islands can hold the charge indefinitely and therefore can maintain the force indefinitely. The connect substrate can also be used as a low impedance switch when connected and offering an infinite impedance when the connect substrate is detached. The devices and circuits of a manufacturing technology can also be incorporated into all of the substrates (for example, the corner, connect, and beam substrates) although this may have not been indicated in the drawings for simplification. The various shapes of the metallic antenna on substrates for antenna formation may be, but not limited to, circular, hexagonal, stripe, rectangular or polygonal shaped. The inventive aspects that are used in the antenna formation are applicable to other system designs using other substrates. The antenna can also be designed for lower earner frequencies than 75 GHz since Electrically Small Antenna (ESA) can be designed. Other examples of antenna, but not an exhaustive list, include omni directional and circular polarized antennas. The inductors have been shown using only one turn and the same metal level; however, the inductors can be multi-turns and can have portions of the metal layers on different levels to avid crossovers and crossunders in the metal layers. The invention can be practiced using the CMOS, MOS, BiCMOS, SOI, MCM, MEMS or BJT technology. The materials to form devices can be silicon, plastic, GaAs, SiGe and SiN.
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