Antenna-in-Package (AiP) technology allows an antenna to be integrated in the package of a wireless device.
The present disclosure relates generally to antenna assemblies, electronic assemblies that include a plurality of antenna assemblies, and methods of making the assemblies.
In some aspects of the present disclosure, an electronic assembly for wireless transmission of information is provided. The assembly includes a circuit board including a plurality of electrically conductive traces; a cover layer disposed on, and substantially co-extensive with, the circuit board, where the cover layer has a major top surface; and a plurality of antenna assemblies disposed on the major top surface of the cover layer and exposing the major top surface therebetween. Each of the antenna assemblies include an antenna for wireless transmission of information at at least one operating frequency in a predetermined frequency range where the antenna is electrically coupled to a corresponding different electrically conductive trace in the plurality of electrically conductive traces, and an adhesive layer bonding the antenna to the major top surface of the cover layer. The adhesive layers in the antenna assemblies have substantially a same first composition and can have a same average first thickness in a direction orthogonal to the circuit board. The antennas in the antenna assemblies have substantially a same second composition and can have a same average second thickness greater than about 5 microns in the direction orthogonal to the circuit board.
In some aspects of the present disclosure, an antenna assembly is provided. The assembly includes a circuit board including an electrically conductive trace; an electronic device mounted on the circuit board and electrically connected to the electrically conductive trace; a cover layer disposed on and substantially encapsulating the electronic device; a copper antenna disposed on the cover layer and electrically connected to the electrically conductive trace; and an adhesive layer disposed on a major top surface of the cover layer and bonding the antenna to the cover layer. The cover layer and the circuit board can be substantially co-extensive with each other in length and width. The copper antenna can have an average grain size of at least about 0.15 microns and an average thickness greater than about 5 microns in a direction orthogonal to the circuit board. The adhesive layer and the circuit board are not co-extensive with each other in at least one of length and width.
In some aspects of the present disclosure, a method of making an antenna assembly is provided. The method includes the steps of providing a circuit board including a plurality of electrically conductive traces and a plurality of electronic devices mounted on the circuit board and electrically connected to the plurality of electrically conductive traces; providing a copper laminate including a copper foil layer permanently bonded to an adhesive layer; disposing substantially co-extensively a cover layer on the circuit board where the cover layer includes an epoxy and has a major top surface; disposing the copper laminate on the cover layer so that the adhesive layer of the copper laminate forms a bond with the major top surface of the cover layer where the bond has sufficiently low peel strength to permit mechanically pulling and peeling of the copper laminate from the cover layer without substantially damaging or leaving residue on the major top surface; forming a plurality of intersecting isolation channels in the copper laminate where the intersecting isolation channels define a plurality of copper assemblies and the isolation channels extend substantially through an entire thickness of the copper laminate so as to substantially isolate the plurality of copper assemblies from a remaining portion of the copper laminate; mechanically pulling and peeling the remaining portion of the copper laminate from the major top surface of the cover layer leaving behind the plurality of copper assemblies where the pulling and peeling of the remaining portion of the copper laminate exposes a corresponding portion of the major top surface of the cover layer; and treating the adhesive layers in the plurality of copper assemblies to form substantially permanent bonds between the copper assemblies and the cover layer.
These and other aspects will be apparent from the following detailed description. In no event, however, should this brief summary be construed to limit the claimable subject matter.
In the following description, reference is made to the accompanying drawings that form a part hereof and in which various embodiments are shown by way of illustration. The drawings are not necessarily to scale. It is to be understood that other embodiments are contemplated and may be made without departing from the scope or spirit of the present description. The following detailed description, therefore, is not to be taken in a limiting sense.
Antenna-in-Package (AiP) is a technology where the antenna of a wireless device is not a separate component within the wireless device but is instead integrated in the device package. AiP technology can be used in a variety of applications where communication modules transmit and/or receive wireless data. However, conventional AiP manufacturing processes are expensive and/or slow. Processes described herein can provide substantially lower raw material and/or processing costs and/or increased production rates compared to conventional AiP processes, according to some embodiments. The processes of the present disclosure can include disposing a coper laminate onto a cover layer of a circuit board, forming (e.g., via laser cutting) a plurality of intersecting isolation channels in the copper laminate to define a plurality of copper assemblies, removing the remaining portion of the copper laminate from the cover layer, and patterning (e.g., via etching) the copper to form an antenna. The result can be an electronic assembly including a plurality of antenna assemblies disposed on the cover layer, or the circuit board can be singulated to provide a plurality of the antenna assemblies. A resulting antenna assembly can include an adhesive layer bonding the antenna to the cover layer where the adhesive layer and the circuit board are not co-extensive with each other in at least one of length and width (e.g., the adhesive layer can have a length and width less than respective lengths and widths of the circuit board).
The first and/or second compositions of the different antenna assemblies 40 can be substantially the same by virtue of being formed from a same layer. For example, a same adhesive layer can be used to make the adhesive layers 60 of the different antenna assemblies 40 and a same metal (e.g., copper) layer can be used to make the antennas 50. The adhesive or copper layer can have a constant composition or can have a composition that varies somewhat over the area of the layer due to ordinary manufacturing variations, for example, or other minor variations that do not substantially affect the performance (e.g., electrical conductivity of the copper layer or bonding strength of the adhesive layer) of the layer.
In some embodiments, the predetermined frequency range is from about 20 GHz to about 120 GHz, or from about 20 GHz to about 40 GHz (e.g., f1 can be about 20 GHz and f2 can be about 40 GHz or about 120 GHz).
In some embodiments, the antenna 50 of at least one of the antenna assemblies 40 is formed on a substrate layer 140 (see, e.g.,
The antennas 50 can be electrically coupled to the traces via a wire or via a wireless coupling. Referring again to
In some embodiments, the electrically conductive traces in the plurality of electrically conductive traces 20 are electrically isolated from each other. In some such embodiments, at least two of the electrically conductive traces that are electrically isolated from each other are connected to a same device 70a as schematically illustrated in
In some embodiments, the cover layer 30 includes epoxy. For example, the cover layer 30 can be formed from an epoxy molding compound.
In some embodiments, the first composition includes epoxy. In some embodiments, the first composition includes nitryl rubber. In some embodiments, the first composition includes epoxy and nitryl rubber. For example, an epoxy resin mixed with nitryl rubber has been found to provide a lower initiation temperature and heat exotherm compared with other materials. This can result in decreased processing time and cost. Epoxy with nitryl rubber can provide a weight loss at 288° C. of less than 2.5% (e.g., about 2%) which is typically desired in chip packaging processes. Other useful adhesives include epoxy resin mixed with high molecular weight acrylic resin.
In some embodiments, the second composition includes a metal such as copper.
In one example, an average grain size of a 6 micron thick electrodeposited copper film was about 0.26 microns. For comparison, a 6 micron thick sputtered copper film had an average grain size of about 0.09 microns. In each case, to measure the grain size, the copper film was coated with a polymer and a platinum layer and then cut using a focused ion beam to expose a surface of the copper film in a plane perpendicular to the copper film. The grain size was then measured in the plane perpendicular to the copper film using an intercept procedure.
Metals typically include atoms arranged on a lattice that can be defined in terms or repeating unit cells.
In one example, the lattice parameter of a 6 micron thick electrodeposited copper film was about 3.613 angstroms. For comparison, a 6 micron thick sputtered copper film had a lattice parameter of about 3.617 angstroms. The lattice parameters were measured as follows: A dispersion of laboratory calibrated tungsten angular reference standard in ethanol was applied to the surface of each sample to be examined by X-ray diffraction. The thickness of the tungsten layer on the sample was sufficient to obtain good signal from the tungsten while retaining sufficient signal from the copper layer beneath the tungsten reference to allow adequate diffraction peal profile fitting. Reflection geometry X-ray diffraction data were acquired using a 0.7 mm point collimated Huber 4-circle diffractometer (Huber Diffraktionstechnik GmbH, Rimsting, Germany). The diffractometer used a molybdenum X-ray source operated at generator settings of 40 kV and 25 mA. The scattered radiation was registered by use of a scintillation detector after application of a zirconium Kbeta filter. Data were collected from 36.0 to 42.0 degree (2 Theta) scattering angle range using angular step size of 0.02 degrees and dwell time of 300 seconds per step. Resulting scattering data were processed using the XRD software Jade (v9, MDI, Livermore, Calif. USA). The background level of each data determined by use of a linear background model. The lattice parameter for the laboratory tungsten angular reference standard had been calibrated using a NIST silicon standard reference material (SRM 640c). The observed peak profiles for the body-centered cubic (BCC) tungsten (220) and (310) peaks and face-centered cubic (FCC) copper (311) peak position were evaluated using a Pearson-7 peak shape model and application of the Jade software peak profile analysis module. The observed tungsten angular reference peaks were used to place the observed copper (311) peak on an absolute scale by linear angular interpolation. The absolute peak positions for the copper (311) was used to calculate the corresponding interplanar spacing for this maximum as well as the copper lattice parameter.
Layers or elements can be described as substantially co-extensive with each other in length and width if at least about 80% of the length and width of each layer or element is co-extensive with at least about 80% of the length and width of each other layer or element. In some embodiments, for layers or elements described as substantially co-extensive with each other in length and width, at least about 85%, or at least about 90%, or at least about 95% of each layer or element is co-extensive in length and width with at least about 85%, or at least about 90%, or at least about 95% of the respective length and width of each other layer or element. In some embodiments, the cover layer 30 and the circuit board 10 are substantially co-extensive with each other in length and width, but the adhesive layer 60 and the cover layer 30 are not substantially co-extensive with each other in length and width.
In some embodiments, as schematically illustrated in
In some embodiments, the antenna assembly 300, 300′ or 300″ includes an electrically conductive line 51, 51′ or 51″ extending from the trace 20 at least through the cover layer 30. In some embodiments, the copper antenna 50 is electrically connected to the electrically conductive trace 20 via an electrically conductive line 51 extending through the adhesive layer 60 and the cover layer 30 as schematically illustrated in
In some embodiments, the antenna 50 is wirelessly coupled to the electrically conductive trace 20 (see, e.g., antenna assembly 40b and trace 20b depicted in
In some embodiments, a method of making an antenna assembly (e.g., 200, 200′,300, 300′,300″) is provided.
In some embodiments, a method of making an antenna assembly includes the steps of providing a circuit board 10 including a plurality of electrically conductive traces 20 and a plurality of electronic devices 70 mounted on the circuit board 10 and electrically connected (e.g., via lines or wires 71) to the plurality of electrically conductive traces 20; providing a copper laminate 80 including a copper foil layer 90 permanently bonded to an adhesive layer 100; disposing substantially co-extensively a cover layer 30 on the circuit board, the cover layer including an epoxy and a major top surface 31; disposing the copper laminate 80 on the cover layer 30 so that the adhesive layer 100 of the copper laminate 80 forms a bond with the major top surface 31 of the cover layer 30, where the bond has sufficiently low peel strength to permit mechanically pulling and peeling of the copper laminate 80 from the cover layer 30 without substantially damaging or leaving residue on the major top surface 31; forming a plurality of intersecting isolation channels 110 in the copper laminate 80, the intersecting isolation channels 110 defining a plurality of copper assemblies 120 which are, in some embodiments, arranged in a regular array of orthogonal rows 121 and columns 122 of copper assemblies, the isolation channels extending substantially through an entire thickness t3 of the copper laminate 80 so as to substantially isolate the plurality of copper assemblies from a remaining portion 130 of the copper laminate 80; mechanically pulling and peeling the remaining portion 130 of the copper laminate from the major top surface 31 of the cover layer 30 leaving behind the plurality of copper assemblies 120, the pulling and peeling of the remaining portion of the copper laminate exposing a corresponding portion 32 of the major top surface 31 of the cover layer 30; treating the adhesive layers 100 (e.g., by raising the temperature to complete a cure of the adhesive) in the plurality of copper assemblies 120 to form substantially permanent bonds between the copper assemblies 120 and the cover layer 30. In some embodiments, the method further includes the step of patterning the copper foil layer 90 in each copper assembly 120 to form an antenna 50 for wireless transmission of information. The antennas can be electrically connected (e.g., via a wired connection or via wireless coupling) to the plurality of electrically conductive traces 20. The method can further include the step of singulating the circuit board to form a plurality of antenna assemblies 300′″ (e.g., corresponding to antenna assembly 300, 300′ or 300″) where each antenna assembly 300′″ includes at least one of the antennas 50.
The isolation channels 110 can be formed via laser cutting, for example, or by using other suitable processes known in the art. Patterning the copper foil layer 90 can be carried out via photolithographic processes or other suitable processes known in the art.
A bond having sufficiently low peel strength to permit mechanically pulling and peeling of the copper laminate 80 from the cover layer 30 without substantially damaging or leaving residue on the major top surface 31 means that there is little damage (e.g., no damage visible with the unaided eye) or no damage and that there is little residue (e.g., no residue visible with the unaided eye) or no residue. For example, as schematically illustrated in
In the embodiments illustrated in
Terms such as “about” will be understood in the context in which they are used and described in the present description by one of ordinary skill in the art. If the use of “about” as applied to quantities expressing feature sizes, amounts, and physical properties is not otherwise clear to one of ordinary skill in the art in the context in which it is used and described in the present description, “about” will be understood to mean within 10 percent of the specified value. A quantity given as about a specified value can be precisely the specified value. For example, if it is not otherwise clear to one of ordinary skill in the art in the context in which it is used and described in the present description, a quantity having a value of about 1, means that the quantity has a value between 0.9 and 1.1, and that the value could be 1.
All references, patents, and patent applications referenced in the foregoing are hereby incorporated herein by reference in their entirety in a consistent manner. In the event of inconsistencies or contradictions between portions of the incorporated references and this application, the information in the preceding description shall control.
Descriptions for elements in figures should be understood to apply equally to corresponding elements in other figures, unless indicated otherwise. Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a variety of alternate and/or equivalent implementations can be substituted for the specific embodiments shown and described without departing from the scope of the present disclosure. This application is intended to cover any adaptations, or variations, or combinations of the specific embodiments discussed herein. Therefore, it is intended that this disclosure be limited only by the claims and the equivalents thereof.
Filing Document | Filing Date | Country | Kind |
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PCT/IB2021/052453 | 3/24/2021 | WO |
Number | Date | Country | |
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63002431 | Mar 2020 | US |