The present invention relates to an electronic system, to a method for manufacturing an electronic system, to a device for manufacturing an electronic system, as well as to a corresponding computer program product.
It is believed that many IC chips, that is, semiconductor substrates having electronic circuits disposed thereon, are individually bonded and molded in a housing. There have always been molded housings that contain two or more chips. This holds for acceleration sensors, rotation-rate sensors and combination sensors, for example. Increasing miniaturization and higher levels of integration require that ever more chips, for example, two MEMS chips, three ASICs, and one microcontroller be installed in one housing. In keeping with developments in the “Internet of Things” sector, the next integration step is to combine MEMS sensors with microcontrollers and a radio chip in a highly integrated molded housing (for example, BGA, LGA).
Against this background, the approach presented here introduces an electronic system composed, for example, of at least one radio chip, as well as of at least one further IC (ASIC, sensor, microcontroller). Advantageous embodiments will become apparent from the respective dependent claims and the following description.
To install the above-mentioned electronic components, they are advantageously stacked in a molded housing to minimize the space consumed on the printed circuit board and thereby achieve a decisive advantage over an installation of individual components. Here, the components having larger lateral dimensions are expediently located further down in the stack. This can lead to the radio chip being the lowermost component or one of the bottom components in the stack.
A significant challenge arises when radio chips are installed in a stack. The components, which are placed over the radio chip, can degrade the proper functioning thereof. Such degradations can even prevent the radio chip from functioning in a specified range, thus, for example, induce a change in the output or even result in a shifting of the transmit and receive frequencies. The result can be that the radio chip is no longer able to communicate with other devices.
An example would be a radio chip, which is configured to transmit in accordance with Bluetooth Specification 4.0, but whose frequency generator is influenced by the other components due to the stacked configuration thereof. This can prevent the radio chip from sending the “advertising” packets thereof on the specified channels 38, 39 and 40, but, in an undefined manner, alongside, making it no longer visible to other Bluetooth devices.
The properties of the radio chip are influenced by the surroundings thereof. The radio chip is normally located in a molded housing and is covered by the mold. The transmission properties of the radio chip are affected by this material due to the dielectric conductivity, thus the permittivity number thereof. The radio chip design must allow for this material, both in terms of the thickness thereof above the active transmission regions of the radio chip, and the permittivity number thereof.
When such a radio chip is installed with other chips and is located further down in the stack, it is inevitable that the material located above the radio chip must change. The material of the other components is typically silicon dioxide and has a substantially higher permittivity number than the mold material.
There are basically two strategies to nevertheless ensure that the radio chip will reliably transmit in the specified range over the entire specified application range (temperature, supply voltage, available external oscillators). First of all, the radio chip could be reconfigured and adapted to the new surroundings. However, this would entail significant costs.
The present invention provides that a spacer element of sufficient thickness and having a permittivity number similar to that of the mold material be introduced above the radio chip. The radio chip may continue to transmit without limitation and independently of temperature.
In accordance with the concept presented here, housings, respectively SiPs (systems-in-package) may advantageously be realized where various chips, respectively electronic components are stacked on one radio chip. It is thus possible to successfully circumvent the need for a potential redesign of the radio chip.
An electronic system having the following features is presented:
a carrier;
at least one radio chip mounted on the carrier;
a spacer element, which is mounted on the radio chip and features a material having a predefined permittivity number; and
at least one electronic component mounted on or above the radio chip or the spacer element.
The electronic system may be understood to be an assemblage of the mentioned features that may each be in miniature. An electronic system of this kind may be used in the highly diverse “Internet of Things” sector, respectively “IoT” for wireless information processing and/or appliance control. The carrier maybe a substrate, respectively a printed circuit board for supporting the remaining components of the electrical system and/or for supplying the same with electric voltage. The radio chip may be understood to be an electronic component that is configured for transmitting and/or receiving electromagnetic radiation in a predefined or desired radio frequency band. The spacer element may be configured to ensure a predefined distance, in particular of the high-frequency portion of the radio chip, to components of the electrical system disposed above the radio chip, and thereby ensure a functioning in the specified range. ‘Spacer’ is the English term that is also commonly used to denote the spacer element. A permittivity number indicates a dielectric conductivity, respectively permeability of a medium for electric fields. ‘Dielectric constant’ is an often used, outdated synonym. The predefined permittivity number may be expressed as the relative permittivity, respectively permeability of the material in a ratio of the permittivity thereof to that of the vacuum, which is defined as a target quantity, on whose basis, the material in question was selected during the manufacture of the electronic system. The electronic component maybe a component from microsystems technology and/or electronics (ASICs), that is configured, in conjunction with the radio chip, to fulfill a predefined function of the electronic system. In particular, the carrier, the radio chip and the spacer element may be formed as layers, respectively plates and be directly stacked one over the other in the above mentioned sequence, the carrier forming the base of the stack.
In accordance with one specific embodiment of the electronic system presented here, the material of the spacer element may have a permittivity number, in particular of less than 10 and typically 3 to 5, that is within a tolerance range of the permittivity number of a molding compound surrounding the electronic component. The spacer element may thereby be completely or partially formed from the silicon dioxide. In this variant, the spacer element may be manufactured very cost-effectively.
The spacer element may also feature at least one further material having another predefined permittivity number. The further material maybe disposed on a first main side of the material facing the carrier and/or on a second main side of the material opposite the first main side and facing away from the carrier. This specific embodiment makes possible further functionalities that go beyond the spacing of the radio chip, in addition to allowing an even more accurate determination of the predefined permittivity number of the spacer elements.
For example, a predefined thickness of the spacer element may be between 50 and 200 μm. Particularly advantageous in this context is a specific embodiment of the approach introduced here where the predefined thickness of the spacer element is between 70 and 90 μm. The thickness may thereby denote a distance between a first main side and a second main side of the spacer element. The spacer element thickness provided here makes it possible to manufacture the electronic system in the miniature size that is especially advantageous for the Internet of Things.
In one specific embodiment of the electronic system, the material and/or the further material may be formed as an adhesive agent for adhering to a main side of the radio chip adjacent to the spacer element. This allows an element that is required anyway to assemble the electronic system to readily fulfill the additional function of spacing the radio chip at a distance. No costs, respectively only very little additional costs are incurred in the manufacture, and no engineering expenditure is entailed.
In accordance with another specific embodiment, the electronic system may also feature a housing. The housing may be configured to at least enclose the electronic component. Thus, the electronic system may be readily protected from external influences. Moreover, the individual components of the stacked electronic system may be additionally fixed in position.
In particular, within a tolerance range, the predefined permittivity number or a sum of the other predefined permittivity number and the other predefined permittivity number may correspond to a permittivity number of the housing. For example, the tolerance range may be conceived to not allow the predefined permittivity number or a sum of the other predefined permittivity number to deviate by more than 10 percent from the permittivity number of the housing. It is thus possible to advantageously eliminate the need for adapting, respectively modifying the frequency of the radio chip, thereby saving costs and time in the manufacture of the electronic system.
Also conceivable is a specific embodiment of the approach introduced here where the electronic component and/or the radio chip are/is configured as a processing unit for controlling at least an actuator and/or for analyzing information and/or as a sensor for recording at least one physical quantity. Such a specific embodiment of the present invention provides the advantage of a very compact design of an electronic system. Its application is characterized by substantial flexibility in different scenarios in terms of the surroundings thereof.
The electronic system may also include a further electronic component. The further electronic component may be configured on the electronic component, for example. This specific embodiment makes it advantageously possible to expand the electronic system by adding further functionalities. Thus, the electronic system may be used more versatilely and/or for more complex tasks.
For example, the electronic component may be configured as a processing unit for controlling and/or analyzing information of the other electronic component. The other electronic component may be configured as a sensor for recording a physical quantity, the electronic component, in particular, being configured as part of the radio chip. The electronic system presented here in this specific embodiment provides numerous possible applications in industry and in private use, here, in particular, in the increasingly important Internet of Things sector.
A method for manufacturing an electronic system is also presented, the manufacturing method including the following steps:
providing a carrier, a radio chip, an electronic component, and a spacer element that features a material having a predefined permittivity number;
mounting the radio chip on the carrier, the spacer element on the radio chip, and the electronic component on the spacer element in order to manufacture the electronic system.
The manufacturing method may be applied to an automated production line to allow an efficient manufacture of a multitude of the above described electronic systems.
A device for manufacturing an electronic system is also presented, the device having the following features:
a feeder device for providing a carrier, a radio chip, an electronic component, and a spacer element that features a material having a predefined permittivity number;
a positioning device for mounting the radio chip on the carrier, the spacer element on the radio chip, and the electronic component on the spacer element in order to manufacture the electronic system.
The device maybe used and configured in the above mentioned automated manufacturing process for implementing, respectively realizing the steps of a variant of the manufacturing method presented here in the devices thereof. This design variant of the present invention in the form of a device also makes it possible for the object of the present invention to be achieved rapidly and efficiently.
A device may be understood here to be an electrical device that processes sensor signals and outputs control and/or data signals as a function thereof. The device may have an interface implemented in hardware and/or software. When implemented in hardware, the interfaces may be part of what is commonly known as an ASIC system, for example, that includes a wide variety of device functions. However, the interfaces may also be separate, integrated circuits or be at least partly made up of discrete components. When implemented in software, the interfaces may be software modules that are present on a microcontroller, for example, in addition to other software modules.
A computer program product or a computer program having program code is also advantageous that may be stored on a machine-readable medium or storage medium, such as a semiconductor memory, a hard-disk memory or an optical memory, and is used for implementing, realizing and/or controlling the steps of the method in accordance with one of the above described specific embodiments, in particular, when the program product or program is executed on a computer or a device.
The approach presented here is described in greater detail in the following with reference to the enclosed drawings.
The following description of advantageous exemplary embodiments of the present invention employs the same or similar reference numerals for the elements that are shown in the various figures and whose function is similar, there being no need to repeat the description of these elements.
Upon assembly of radio chip system 100, it should be noted that a high frequency circuit of radio chip 104 is defined toward the top side of the chip. Radio chip 104 is normally configured to be installed with a molded cover 114 of a few hundred micrometers. This mold 114 takes the high frequency design into consideration in the configuration of the components of radio chip 104 that are relevant to high frequency.
With reference to a schematic representation,
As illustrated in
Spacer element, respectively spacer 206 features a material 210 having a predefined permittivity number, respectively dielectric constant. Spacer 206 may be completely or partially formed from material 210. The predefined permittivity number of spacer element 206 makes it possible to maintain, without limitation, the radio transmission functionality of subjacent radio chip 204, independently of further components of electronic system 200 stacked over spacer element 206. The predefined permittivity number of spacer element material 210 may be derived from a predefined thickness of material 210 forming spacer element 206. Alternatively or additionally, the predefined permittivity number may result from a chemical and/or physical composition of material 210.
As illustrated in
In the exemplary embodiment of electronic system 200 shown in
In the case of the exemplary embodiment of electronic system 200 shown in
In the exemplary embodiment of electronic system 200 shown in
In the exemplary embodiment shown in
In the case of the illustrated exemplary embodiment of electronic system 200 on microcontroller 208 for fixing microcontroller 208 in place on spacer 206 and on radio chip 204 for fixing radio chip 204 in place on substrate 202, other adhesive agent layers 312 are disposed thereon.
Upon assembly of an electronic system, the radio chip is configured to define the high-frequency circuit toward the top side of the chip. Chips are normally configured to be installed with a molded cover of a few hundred micrometers. The high frequency design takes this mold into consideration in the configuration of the components that are relevant to high frequency.
Electronic system 200 presented here is configured to allow radio chip 204 and MEMS chips 208, 300 to be installed one over the other within housing 302, thus further chips 208, 300 to be stacked on radio chip 204. Thus, further chips of silicon having a permittivity number of approximately 11 are typically located within the stack. Using the spacer element, respectively spacer 206 having a low dielectric constant, eliminates the risk of subjecting radio chip 204 to a frequency shift, since it precludes any influence of spacer chip 206 on the high frequency component of radio chip 204. Thus, the approach introduced here eliminates the need for any adaptation to the high frequency design of radio chip 204 that is based on a molding compound having a permittivity number of approximately 3 to 4 and a height of at least 100 μm, for example.
In another schematic representation,
Besides the mentioned materials, other materials that may be produced and set as thin substrates, such as other types of glass or already cured molding compound, for example, may conceivably be used in spacer element, respectively spacer 206 illustrated in
The thicknesses and functional descriptions indicated in the figures are exemplary; the principle introduced here applies independently of a thickness of the materials used.
The concept presented here makes it possible to realize products that employ sensors, and a microcontroller having an installed radio front end.
The described exemplary embodiments shown in the figures are only selected exemplarily. Various exemplary embodiments may be combined with one another entirely or by individual features. An exemplary embodiment may also be supplemented by features of another exemplary embodiment.
The method steps presented here may also be repeated and be executed in a sequence other than that described.
If an exemplary embodiment includes an “AND/OR” logic operation between a first feature and a second feature, then this is to be read as the exemplary embodiment in accordance with a first specific embodiment having both the first feature, as well as the second feature and, in accordance with another specific embodiment, either only the first feature or only the second feature.
Number | Date | Country | Kind |
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102014203385.3 | Feb 2014 | DE | national |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2015/052510 | 2/6/2015 | WO | 00 |