DECOUPLING METHOD FOR SEMICONDUCTOR DEVICE
20240228264 ยท 2024-07-11
Assignee
Inventors
Cpc classification
B81B3/0072
PERFORMING OPERATIONS; TRANSPORTING
B81C2203/038
PERFORMING OPERATIONS; TRANSPORTING
H01L25/0652
ELECTRICITY
B81C1/00666
PERFORMING OPERATIONS; TRANSPORTING
H01L2225/06548
ELECTRICITY
H01L2225/06506
ELECTRICITY
H01L21/4875
ELECTRICITY
H01L25/50
ELECTRICITY
H01L2924/167
ELECTRICITY
B81B2207/015
PERFORMING OPERATIONS; TRANSPORTING
H01L2225/06527
ELECTRICITY
B81B2207/012
PERFORMING OPERATIONS; TRANSPORTING
H01L2225/0651
ELECTRICITY
H01L2924/16251
ELECTRICITY
H01L25/065
ELECTRICITY
H01L23/04
ELECTRICITY
B81C2203/0771
PERFORMING OPERATIONS; TRANSPORTING
H01L2224/48137
ELECTRICITY
International classification
B81B3/00
PERFORMING OPERATIONS; TRANSPORTING
B81C1/00
PERFORMING OPERATIONS; TRANSPORTING
H01L21/48
ELECTRICITY
H01L25/00
ELECTRICITY
Abstract
A sensor package includes a packaging formed by a package bottom, first and second sidewalls extending upwardly from first and second opposite sides of the package bottom, and third and fourth sidewalls extending upwardly from third and fourth opposite sides of the package bottom, the sidewalls and package bottom defining a cavity. An integrated circuit is attached to the package bottom. A plate extends between two of the sidewalls within the cavity and is spaced apart from the package bottom. Sensors are attached to a top surface of the plate on opposite sides of an opening. Wire bondings electrically connect pads on a top face of the sensor to corresponding pads on a top face of the integrated circuit, for example by passing through the opening in the plate or passing past a side end of the plate. A lid extends across and between the sidewalls to close the cavity.
Claims
1. A sensor package, comprising: a packaging comprising a package bottom, first and second sidewalls extending upwardly from first and second opposite sides of the package bottom, and third and fourth sidewalls extending upwardly from third and fourth opposite sides of the package bottom, wherein the first, second, third, and fourth sidewalls and the package bottom define a cavity; an integrated circuit attached to the package bottom; a plate extending between at least two of the sidewalls within the cavity and being spaced apart from the package bottom; at least one sensor attached to a top surface of the plate; wire bondings electrically connecting pads on a top face of the at least one sensor to corresponding pads on a top face of the integrated circuit; and a lid extending across and between the first, second, third, and fourth sidewalls to thereby close the cavity.
2. The sensor package of claim 1, wherein the plate extends between the first and second sidewalls and has an opening formed therein; and wherein the wire bondings pass through the opening to electrically connect the pads on the top face of the at least one sensor to the corresponding pads on the top face of the integrated circuit.
3. The sensor package of claim 2: wherein the first sidewall comprises a first portion extending upwardly from the first side of the package bottom and a second portion extending upwardly from a distal end of the first portion, with the second portion being thinner than the first portion in a stair-stepped shape so as to define a first support shelf; wherein the second sidewall comprises a first portion extending upwardly from the second side of the package bottom and a second portion extending upwardly from a distal end of the second portion, with the second portion of the second sidewall being thinner than the first portion of the second sidewall in a stair-stepped shape so as to define a second support shelf; and wherein the plate is carried by and extends between the first and second support shelves.
4. The sensor package of claim 1: wherein the plate extends between the first and second sidewalls and has an opening formed therein; wherein the at least one sensor comprises first and second sensors attached to the top surface of the plate on opposite sides of the opening; and wherein the wire bondings comprise: first wire bondings passing through the opening to electrically connect the pads on the top face of the first sensor to the corresponding pads on the top face of the integrated circuit; and second wire bondings passing through the opening to electrically connect the pads on the top face of the second sensor to the corresponding pads on the top face of the integrated circuit.
5. The sensor package of claim 1, wherein the packaging and plate are constructed from ceramic.
6. The sensor package of claim 1, wherein the lid is constructed from metal.
7. The sensor package of claim 1, wherein the integrated circuit is an application specific integrated circuit (ASIC).
8. The sensor package of claim 1, further comprising: vias formed within the package bottom to electrically connect pads on a top surface of the package bottom to corresponding pads on a bottom surface of the package bottom; and additional wire bondings electrically connecting the pads on the top surface of the package bottom to corresponding pads on the top face of the integrated circuit.
9. The sensor package of claim 1, wherein the plate extends between the third and fourth sidewalls, adjacent to the first sidewall; and wherein the wire bondings extend past a side end of the plate to electrically connect the pads on the top face of the at least one sensor to the corresponding pads on the top face of the integrated circuit.
10. The sensor package of claim 9, wherein the plate is sized to extend outwardly from the first sidewall toward the second sidewall but not reach the second sidewalls.
11. The sensor package of claim 9: wherein the first sidewall comprises a first portion extending upwardly from the first side of the package bottom and a second portion extending upwardly from a distal end of the first portion, with the second portion being thinner than the first portion in a stair-stepped shape so as to define a first support shelf; and wherein the plate is carried by the first support shelf.
12. The sensor package of claim 11, wherein the second sidewall has a substantially constant thickness.
13. The sensor package of claim 1: wherein the plate extends between the third and fourth sidewalls, adjacent to the first sidewall, with the plate being sized to extend outwardly from the first sidewall toward the second sidewall but not reach the second sidewall; wherein the at least one sensor comprises first and second sensors attached to the top surface of the plate; and wherein the wire bondings comprise: first wire bondings extending past a side end of the plate to electrically connect the pads on the top face of the first sensor to the corresponding pads on the top face of the integrated circuit; and second wire bondings extending past the side end of the plate to electrically connect the pads on the top face of the second sensor to the corresponding pads on the top face of the integrated circuit.
14. A method, comprising: a) attaching an integrated circuit to a top surface of a package bottom of a package; b) attaching at least one sensor to a top surface of a plate on opposite sides of an opening formed in the plate; c) mounting the plate between sidewalls of the package in a spaced apart fashion from the top surface of the package bottom; d) electrically connecting pads on a top face of the at least one sensor to corresponding pads on a top face of the integrated circuit using wire bondings; and e) affixing a lid to extend across and between the sidewalls to thereby close a cavity within the package defined by the sidewalls and the package bottom.
15. The method of claim 14, wherein electrically connecting the pads on the top face of the at least one sensor to the corresponding pads on the top face of the integrated circuit includes passing the wire bondings through an opening in the plate.
16. The method of claim 15, further comprising, prior to a), providing the package as having a package bottom, first and second sidewalls extending upwardly from first and second opposite sides of the package bottom, and third and fourth sidewalls extending upwardly from third and fourth opposite sides of the package bottom; and wherein, in c), the plate is mounted to extend at least between the first and second sidewalls.
17. The method of claim 16, wherein the package is provided as having the first sidewall formed by a first portion extending upwardly from the first side of the package bottom and a second portion extending upwardly from a distal end of the first portion, with the second portion being thinner than the first portion in a stair-stepped shape so as to define a first support shelf, and as having the second sidewall formed by a first portion extending upwardly from the second side of the package bottom and a second portion extending upwardly from a distal end of the second portion, with the second portion of the second sidewall being thinner than the first portion of the second sidewall in a stair-stepped shape so as to define a second support shelf; and wherein, in c), the plate is mounted between the sidewalls of the package by affixing a bottom surface of the plate to the first and second support shelves.
18. The method of claim 14, further comprising, prior to c), electrically connecting pads on the top surface of the package bottom to corresponding pads on the top face of the integrated circuit using additional wire bondings.
19. The method of claim 14, wherein electrically connecting the pads on the top face of the at least one sensor to the corresponding pads on the top face of the integrated circuit includes passing the wire bondings past a side end of the plate.
20. The method of claim 19, further comprising, prior to a), providing the package as having a package bottom, first and second sidewalls extending upwardly from first and second opposite sides of the package bottom, and third and fourth sidewalls extending upwardly from third and fourth opposite sides of the package bottom; and wherein, in c), the plate is mounted to extend from the first sidewall.
21. The method of claim 20, wherein the package is provided as having the first sidewall formed by a first portion extending upwardly from the first side of the package bottom and a second portion extending upwardly from a distal end of the first portion, with the second portion being thinner than the first portion in a stair-stepped shape so as to define a first support shelf; and wherein, in c), the plate is mounted between the sidewalls of the package by affixing a bottom surface of the plate to the first support shelf.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
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DETAILED DESCRIPTION
[0063] The following disclosure enables a person skilled in the art to make and use the subject matter disclosed herein. The general principles described herein may be applied to embodiments and applications other than those detailed above without departing from the spirit and scope of this disclosure. This disclosure is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed or suggested herein. In addition, in the below description, where any individual wire bonding connecting two pads is described, understand there may instead be multiple such wire bondings connected between a corresponding number of pads on the same surfaces/faces/devices in the same fashion.
[0064] Now described with initial reference to
[0065] The interior of the package 11 includes four sidewalls, with two of the sidewalls 11a, 11b opposite each other across the bottom 11c of the package 11 being shown in the cross section of
[0066] An application specific integrated circuit (ASIC) 20 is attached to the upper surface of the package bottom 11c, with wire bonding 20a connecting pad 20f on the top face of the ASIC 20 to pad 20b and via 20c within the package bottom 11c of the package that are in turn connected to dual-flat no lead (DFN) pad 13 on the bottom surface of the package bottom 11c. A first sensor 21 is attached to the top surface of the plate 16 adjacent the support shelf 15a, and a second sensor 22 is attached to the top surface of the plate 16 adjacent the support shelf 15b. The first sensor 21 may be a microelectromechanical systems (MEMS) device such as an accelerometer, and the second sensor 22 may be another MEMS device such as a gyroscope.
[0067] Indeed, the sensors 21, 22 are silicon based and may be any suitable sensors that either include mechanical components (e.g., MEMS components, optical components, etc.) or electrical components sensitive to the piezoelectric effect (e.g., at least one piezo-resistor and/or a Hall effect sensor).
[0068] A wire bonding 21a passes through the opening 25 in the plate 16 to connect pad 21b on the top face of the sensor 21 to corresponding pad 20d on the top face of the ASIC 20, and a wire bonding 22a passes through the opening 25 in the plate 16 to connect pad 22b on the top face of the sensor 22 to corresponding pad 20e on the top face of the ASIC 20.
[0069] To ease a full understanding, a top plan view of the plate 16 with the sensors 21, 22 attached to the top surface thereof opposite to each other across the opening 25 is shown in
[0070] As a result of soldering the sensor package 10 to a printed circuit board (PCB), mechanical stresses (e.g., normal and/or shear stresses, generally lateral but also out of plane) are applied to the sensor package 10. The advantage of the design of the sensor package 10 is that while mechanical stresses placed on the package 11 are imparted to the package bottom 11c through the mechanical connection to the PCB, those mechanical stresses are not ultimately passed through to the plate 16, and are therefore not imparted to the sensors 21, 22 on the top surface of the plate 16. While the ASIC 20 will be subjected to the stresses imparted to the package 11 (which are transmitted to the ASIC 20 through its connection to the top surface of the package bottom 11c), the ASIC contains solely electrical components and does not contain mechanical components, and as such its proper operation is not impacted.
[0071] This design of the sensor package 10 therefore results in a significant reduction in stresses passed to the sensors 21, 22, contributing to a longer service life and more predictable behavior. In addition, the performance of the sensors 21, 22 themselves may be increased, as their performance will be similar to what it would be if the sensor package 10 was a standalone device and not attached to a PCB. This in turn may help reduce the amount of testing to be performed.
[0072] Additional designs and process flows for forming those designs (as well as the design of
[0073] Now described with reference to
[0074] Wire bonding 20a is then used to connect pad 20f on the top face of the ASIC 20 to corresponding pad 20b and via 20c on the top surface of the package bottom 11c, as shown in
[0075] The lid 12 is then affixed over the tops of the sidewalls 11a, 11b to seal off the cavity 19 within the package 11, as shown in
[0076] An alternative to the design of the sensor package 10 is now described with reference to
[0077] Now described with reference to
[0078] Wire bonding 20a is then used to connect pad 20d on the top face of the ASIC 20 to corresponding pad 20b on the top surface of the package bottom 11c, as shown in
[0079] Other embodiments of sensor packages and process flows for manufacturing those embodiments are now described. Beginning with the embodiment of the sensor package 10 of
[0080] Now described with reference to
[0081] Next, the plate 16 is flipped, as shown in
[0082] Instead of the sensors 21, 22 being attached to opposite faces of the ASIC 20 as in the sensor package 10 of
[0083] Now described with reference to
[0084] Next, the assembled plate 16 is mounted within the package 11 such that it rests on and extends between the support shelves 15a, 15b, as shown in
[0085] As has been explained, the sensor packages 10, 10, 10, 10 described herein reduce the mechanical stresses placed on the sensors 21, 22. In fact, this reduction has been found by the Inventors to be on the order of 40.34% to 49.4%, as shown in the graphs of
[0086] Finally, it is clear that modifications and variations may be made to what has been described and illustrated herein, without thereby departing from the scope of this disclosure, as defined in the annexed claims.
[0087] While the disclosure has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be envisioned that do not depart from the scope of the disclosure as disclosed herein. Accordingly, the scope of the disclosure shall be limited only by the attached claims.