This application is related to U.S. patent application Ser. No. 13/306,827 filed on Nov. 29, 2011, now U.S. Pat. No. 8,617,927 which is incorporated herein by reference. This application is also related to U.S. patent application Ser. No. 14/950,667 filed on Nov. 24, 2015, now U.S. Pat. No. 9,508,652 which is incorporated herein by reference. This application is also related to U.S. patent application Ser. No. 15/169,591 filed on May 31, 2016 which is incorporated herein by reference.
The present disclosure is directed in general to wafer level packaging of integrated circuits and in particular to multi-scale and multi-chip integration.
A variety of technologies are known for single-level wafer-scale integration. However, some of these include integration of multiple chips but fail to address effective thermal management, which is a major issue in integrating multiple chips. The next step in the technological evolution is the multi-scale integration, particularly one that is easily scalable and this area is yet to be developed due to the compounding thermal management issues that come with this large multi-scale integration.
Historically, wire bonds have been used in the prior art for both connecting contacts on a chip to its package and also for chip to chip connections when multiple chips reside in a single package. In today's technologies, the wire bonds now are so large compared with the device geometries of modern integrated chips (ICs) that their size can make it difficult to couple modern ICs either with pins in the packaging in which the ICs reside or with neighboring ICs when multiple ICs are packaged together.
U.S. Pat. No. 8,617,927 which is incorporated herein, teaches a method of mounting electronic dies or chips into an electroformed heat spreader offering an integrated solution to thermal management at the single-level wafer-scale integration. U.S. application Ser. No. 15/169,591, incorporated herein, addresses another important technology in connecting die to package using electroplated and suspended interconnects over integrated heat spreaders. U.S. application Ser. No. 14/950,667 (141211), which is also incorporated herein, addresses another aspect of the single-level wafer-scale integration of direct IC-to-package wafer-level packaging with integrated thermal heat spreaders. While these technologies address various aspects of single-level wafer-scale integration while offering solutions to thermal management problems, there is a dire need to expand the scope to multi-level wafer-scale integration while at the same time solving the massive thermal management issues that come with this large scale multi-level integration.
To address one or more of the above-deficiencies of the prior art, one embodiment described in this disclosure provides for a recursive metal-embedded chip assembly (R-MECA) process comprising, assembling two or more component modules face-down on a carrier substrate, wherein component modules each comprise at least one of an assembly prepared using the metal embedded chip assembly (MECA) process, an Integrated Circuit (IC) chip, a macro cell, and a die, embedding a heat spreader material on the assembly, releasing the carrier substrate from the two or more component modules and forming interconnects between the component modules, by forming multilayer interconnects on the side where the carrier substrate was released.
The disclosure covers the product made by the process comprising, dicing of one or more metal embedded chip assembly (MECA) modules, assembling the MECA modules on a carrier substrate with face-down, attaching a packaging substrate, embedding metal by filling the holes in the packaging substrate, releasing the substrate, flipping the wafer and forming interconnects, wherein MECA modules comprise of assemblies prepared using the metal embedded chip assembly process and/or any Integrated Circuit (IC) chips and/or any macro cell and/or a die fabricated in any technology.
The disclosure also provides for a process of integrating discrete components to the MECA modules and recursively using the process described above to achieve a large scale integration with integrated thermal spreaders.
Certain embodiments may provide various technical features depending on the implementation. For example, a technical feature of some embodiments may include the capability to provide for large scale integration of different technology dies.
Although specific features have been enumerated above, various embodiments may include some, none, or all of the enumerated features. Additionally, other technical features may become readily apparent to one of ordinary skill in the art after review of the following figures and description.
For a more complete understanding of the present disclosure and its features, reference is now made to the following description taken in conjunction with the accompanying drawings, in which like reference numerals represent like parts:
It should be understood at the outset that, although example embodiments are illustrated below, the present technology may be implemented using any number of techniques, whether currently known or not. The present technology should in no way be limited to the example implementations, drawings, and techniques illustrated below. Additionally, the drawings are not necessarily drawn to scale.
The proposed technology presents a recursive metal-embedded chip assembly (R-MECA) technology for heterogeneous integration of multiple die from diverse device technologies. One of the features of this disclosure is the “recursive” aspect of this integration technology, which enables integration of increasingly-complex subsystems while bridging different scales for devices, interconnects and components. Additionally, high thermal management performance is maintained through the multiple recursive levels of R-MECA, a key requirement for high-performance heterogeneous integration of digital, analog mixed signal and RF subsystems.
Even today, wire bonding techniques are used when it comes to interconnecting heterogeneous devices. This disclosure introduces a new technology which effectively replaces prior art wire bonding techniques with a new die to package and die to die interconnects which may be conveniently suspended over electrically conductive surfaces such as integrated heat sinks (or heat spreaders) which may be included in the packaging. The new technology is particularly suitable for wafer-level integration and wafer-level processing, which enables parallel interconnection of a multitude of chips at the wafer scale.
In an embodiment of this technology, at the wafer-scale, chips from diverse technologies and different thicknesses are initially embedded in a metal heat spreader surrounded by a mesh wafer serving as a host. The approach uses metal embedding on the backside of the chips as a key differentiator to achieve among other things, high-density integration and built-in thermal management. After die embedding, wafer-level front side interconnects are fabricated to interconnect the various chips with each other. The wafer is then diced into individual MECA modules, and forms the level one for multi-scale R-MECA integration. These modules are subsequently integrated into another wafer or board using the same integration approach recursively. Additional components such as discrete passive resistors, capacitors, inductors can be integrated at the second level, once the high-resolution, high-density integration has been performed at the level zero.
For complex high-power RF subsystems requiring highly integrated heterogeneous device technologies as well as bulky passive components such as discrete off-the-shelf resistors, inductors and capacitors, the proposed technology of Metal Embedded Chip Assembly (MECA) approach is particularly revolutionary because it can be implemented sequentially in a recursive manner (R-MECA) with increasingly complex modules and high-performance thermal management.
The standard MECA integration process flow 100 is illustrated in
The first step 110 in the MECA process is to dice the IC chips or the IP blocks or macros that need to be put together and interconnected in the MECA process. They can be from one or more different technologies or from the same technology family. In the illustration of
Such MECA modules can now be further packaged using the same integration approach at a larger scale, where the requirements on chip assembly and interconnect density are not as stringent. This is illustrated in a recursive MECA process described in
The modules, which feature different IP blocks, and typically different die and interconnect scales, are then integrated using the recursive MECA approach, which is a structured repeat of the process shown in
This recursive MECA (R-MECA) process 500 illustrated in
The first step 510 in the R-MECA process is to dice and sort out the MECA modules and/or IC chips or the IP blocks or macros of similar or dissimilar technologies that need to be put together and interconnected in the MECA process. In the illustration of
A conceptual schematic of R-MECA featuring two-tier integration is shown in
A good example is a second level integration with a printed wiring board since most high-performance electronics require biasing and filtering network that still rely on the use of discrete bulk components such as resistors, capacitors and inductors. This is illustrated in the process flow 1010 illustrated in
Examples of packaging form materials include Silicon, quartz, PolyChlorinated Biphenyls (PCB), FR4, SiC, metal plates and various polymers. The preferred substrate thickness is around 200 um thick. The substrate thickness typically ranges from 50-3000 um and needs to be at least 1 um thicker than the thickest chip to be integrated. The substrate cavity size is typically at least 1 um larger than the chip array dimensions. The thickness of the recursive packaging substrate must be at least 1 micron thicker than the thickness of the thickest MECA sub-modules (packaging substrate in process 500 must be thicker than packaging substrate in process 100).
Examples of heat spreader materials include Copper, gold, silver, copper alloys, copper-diamond, copper-CNT, and other high thermal conductivity materials or composites known by experts in the field. The heat spreaders have thickness similar to the packaging substrate stated earlier. Heat spreaders are typically deposited using deposition techniques such as Electroplating/Electroforming.
Interconnect materials for both the processes 100 and 500 are materials with high electrical conductivity such as gold, copper or silver or combination alloys there-of for the conductors and BCB, SU-8, polyimide, air, SiO2, SiN and Al2O3 or combination there-of for the dielectric layers that feature low dielectric loss tangent. Interconnect materials used for conductors and dielectrics can vary in thickness from 0.1 to 500 um with a preferred thickness of 5 um for conductors and 3 um for dielectrics. The width/pitch can vary from 0.5 to 500 um (preferred 25 um). Deposition techniques such as electroplating, sputtering, or evaporation for the metallic conductors can be used. For the dielectrics, spin coating, PECVD or ALD processes can be used to deposit the dielectrics.
Carrier substrate materials can be silicon, glass or other materials with low surface roughness. The IC chips or macros can be made from SiC, Si, SiGe, GaAs, InP, alumina, PCB or other materials known in the art. The substrate can have width or length ranging from 0.025 mm to 25 mm and thickness ranging from 1 to 1000 um.
An example interconnect process described in step 550 for chip-to-chip or chip-to-board interconnects can use the following process steps and technologies or variants there-of: (1) Sputter a metal seed layer or membrane (example is Ti/Au for a thickness preferably of 200/1000 A with a range of 100-500 A to 500 to 10000 A respectively); (2) Spin coat and pattern a layer of photoresist; (3) Plate gold (preferably 3 um, with range from 1 to 10 um) to form metal 1 layer interconnects; (4) Strip resist and etch metal seed layer (e.g.: ion mill or wet etching); (5) Spin coat or deposit a dielectric layer (e.g., BCB, SU-8, SiO2, SiN) with thickness of 0.1 to 10 um (preferably 3 um); (6) Pattern the layer using photo-definition, or dry etch techniques to open up regions on the plated gold to be contacted from metal 1 layer interconnects to metal 2 layer interconnects; (7) Sputter a new metal seed layer; (8) Spin coat and pattern a layer of photoresist to create metal 2 layer; (9) Plate gold (preferably 5 um) with thickness ranging 0.5 to 500 um to form “metal 2 layer” interconnects; (10) Strip resist and etch metal seed layer.
The purposed technology in this disclosure offers methods to develop a low-cost and manufacturable wafer-level integration technology for various systems including RF subsystems. It addresses thermal management and other limitations in high-frequency subsystems featuring high-power-density active devices such as GaN devices and GaN RF MMIC circuits.
Compared to current technology, the technology offered in this disclosure offers several advantages. Currently, heterogeneously-integrated chip modules still rely on conventional wire bonding and die attach to connect to large discrete capacitors and resistors required for biasing and filtering. In contrast, the approach presented here relies on parallel processing and microfabrication technologies to integrate these modules with the discrete components, while addressing low loss interconnects with no wire bonds from the module to the RF boards. In addition, it offers integrated thermal management, where modules are embedded in high thermal conductivity heat spreaders. Another main advantage of the proposed concepts is the recursive nature of the process that allows multi-scale integration with integrated metal embedding techniques.
The concepts of this disclosure is applicable to a wide variety of companies and product lines and it can offer significant added value by direct and indirect cost savings, added functionalities which can increase customer base and market share, and opportunities for increased revenues. Two major applications of this technology are in cooling and integration (IP re-use for example) in high power RF front-ends and digital and analog mixed signal designs.
In particular configurations, it may be desirable to use process 500 described herein to integrate dies of different technology characteristics. In other configurations, the recursive nature of this process with the integrated heat spreader will support very large scale integration including discrete components, beyond the capabilities of today's technologies.
Modifications, additions, or omissions may be made to the systems, apparatuses, and methods described herein without departing from the scope of the technology. The components of the systems and apparatuses may be integrated or separated. Moreover, the operations of the systems and apparatuses may be performed by more, fewer, or other components. The methods may include more, fewer, or other steps. Additionally, steps may be performed in any suitable order. As used in this document, “each” refers to each member of a set or each member of a subset of a set.
To aid the Patent Office, and any readers of any patent issued on this application in interpreting the claims appended hereto, applicants wish to note that they do not intend any of the appended claims or claim elements to invoke paragraph 6 of 35 U.S.C. Section 112 as it exists on the date of filing hereof unless the words “means for” or “step for” are explicitly used in the particular claim.
This Application is related to and claims priority and benefit of U.S. Provisional Patent Application Ser. No. 62/244,659, filed on Oct. 21, 2015, which is hereby incorporated by reference in its entirety.
Number | Name | Date | Kind |
---|---|---|---|
3681513 | Hargis | Aug 1972 | A |
4159221 | Schuessler | Jun 1979 | A |
5073521 | Braden | Dec 1991 | A |
5198385 | Devitt et al. | Mar 1993 | A |
5262351 | Bureau et al. | Nov 1993 | A |
5276455 | Fitzsimmons et al. | Jan 1994 | A |
5371404 | Juskey et al. | Dec 1994 | A |
5583377 | Higgins, III | Dec 1996 | A |
5953594 | Bhatt et al. | Sep 1999 | A |
6018459 | Carlson et al. | Jan 2000 | A |
6028367 | Yu | Feb 2000 | A |
6249439 | DeMore et al. | Jun 2001 | B1 |
6900765 | Navarro et al. | May 2005 | B2 |
6989592 | Chang et al. | Jan 2006 | B2 |
7015060 | Kubena et al. | Mar 2006 | B1 |
7067397 | Chang-Chien et al. | Jun 2006 | B1 |
7271479 | Zhao et al. | Sep 2007 | B2 |
7292381 | Patterson et al. | Nov 2007 | B1 |
7364063 | Schaenzer et al. | Apr 2008 | B2 |
7683469 | Oh et al. | Mar 2010 | B2 |
7733265 | Margomenos et al. | Jun 2010 | B2 |
7777315 | Noquil | Aug 2010 | B2 |
7808013 | Mendendorp, Jr. et al. | Oct 2010 | B2 |
7947906 | Lee | May 2011 | B2 |
8013434 | Lin et al. | Sep 2011 | B2 |
8093690 | Ko et al. | Jan 2012 | B2 |
8178963 | Yang | May 2012 | B2 |
8178964 | Yang | May 2012 | B2 |
8241962 | Lin | Aug 2012 | B2 |
8334592 | Bhagwagar et al. | Dec 2012 | B2 |
8375576 | Kwon | Feb 2013 | B2 |
8580608 | Hsu | Nov 2013 | B2 |
8617927 | Margomenos | Dec 2013 | B1 |
8644020 | Lau et al. | Feb 2014 | B2 |
8754522 | Meyer et al. | Jun 2014 | B2 |
8759147 | Choi | Jun 2014 | B2 |
8927339 | Lin | Jan 2015 | B2 |
9040420 | Sugiyama et al. | May 2015 | B2 |
9059140 | Margomenos | Jun 2015 | B1 |
9214404 | Margomenos et al. | Dec 2015 | B1 |
9337124 | Herrault | May 2016 | B1 |
9385083 | Herrault | Jul 2016 | B1 |
9508652 | Herrault | Nov 2016 | B1 |
20030006499 | Choi | Jan 2003 | A1 |
20040126931 | Hembree | Jul 2004 | A1 |
20050077596 | Bauer et al. | Apr 2005 | A1 |
20050077614 | Chengalva et al. | Apr 2005 | A1 |
20050155752 | Larson et al. | Jul 2005 | A1 |
20060027635 | Schaenzer et al. | Feb 2006 | A1 |
20060091509 | Zhao et al. | May 2006 | A1 |
20060157223 | Gelorme et al. | Jul 2006 | A1 |
20060292747 | Loh | Dec 2006 | A1 |
20070015666 | Thieme et al. | Jan 2007 | A1 |
20070075420 | Lu et al. | Apr 2007 | A1 |
20070247851 | Villard | Oct 2007 | A1 |
20070290326 | Yang et al. | Dec 2007 | A1 |
20080099770 | Mendendorp et al. | May 2008 | A1 |
20080128897 | Chao | Jun 2008 | A1 |
20080179725 | Chia et al. | Jul 2008 | A1 |
20080298021 | Ali et al. | Dec 2008 | A1 |
20090108437 | Raymond | Apr 2009 | A1 |
20090134421 | Negley | May 2009 | A1 |
20090294941 | Oh et al. | Dec 2009 | A1 |
20090309209 | Chen | Dec 2009 | A1 |
20100140799 | Do et al. | Jun 2010 | A1 |
20100283144 | Liang | Nov 2010 | A1 |
20100285637 | Khan et al. | Nov 2010 | A1 |
20100320588 | Dahilig et al. | Dec 2010 | A1 |
20100327465 | Shen et al. | Dec 2010 | A1 |
20110049558 | Lin et al. | Mar 2011 | A1 |
20110059578 | Lin et al. | Mar 2011 | A1 |
20110291249 | Chi et al. | Dec 2011 | A1 |
20120129298 | Lin et al. | May 2012 | A1 |
20120139095 | Manusharow et al. | Jun 2012 | A1 |
20120217627 | Tseng et al. | Aug 2012 | A1 |
20120241942 | Ihara | Sep 2012 | A1 |
20120276403 | Nakagawa et al. | Nov 2012 | A1 |
20130093085 | Seah | Apr 2013 | A1 |
20140084445 | Lin | Mar 2014 | A1 |
20140332974 | Schuckman et al. | Nov 2014 | A1 |
20150007965 | Joshi | Jan 2015 | A1 |
Entry |
---|
U.S. Appl. No. 14/950,667, Herrault et al., filed Nov. 24, 2015. |
U.S. Appl. No. 15/169,591, Herrault et al., filed May 31, 2016. |
U.S. Appl. No. 15/136,835, Herrault et al., filed Apr. 22, 2016. |
Brown, D.F. et al., “High-speed, enhancement-mode GaN power switch with regrown n+ GaN ohmic contacts and staircase field plates,” IEEE Electron Device Letters, vol. 34, No. 9, pp. 1118-1120, Sep. 2013. |
Ejeckam, F. et al., “Diamond for enhanced GaN device performance,” in Proc. IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm), Orlando, FL, May 27-30, 2014, pp. 1206-1209. |
Faqir, M. et al.,“Improved thermal management for GaN power electronics: Silver diamond composite packages,” Microelectronics Reliability, vol. 52, Issue 12, pp. 3022-3025, 2012. |
Margomenos, A. et al., “Wafer-level packaging method incorporating embedded thermal management for GaN-based RF front-ends,” in Proc. IEEE Intersociety conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITHERM), Orlando, FL, May 27-30, 2014, pp. 976-981. |
Nochetto, H.C. et al., “GaN HEMT junction temperature dependence on diamond substrate anisotropy and thermal boundary resistance,” in Proc. IEEE Compound Semiconductor Integrated Circuit Symposium (CSICS), La Jolla, CA, Oct. 14-17, 2012, pp. 1-4. |
Shinohara, K. et al., “Scaling of GaN HEMTs and Schottky diodes for submillimeter-wave MMIC applications,” IEEE Trans. Electron Devices, vol. 60, No. 10, pp. 2982-2996, 2013. |
U.S. Appl. No. 13/306,827, Margomenos, et al., filed Nov. 2011. |
U.S. Appl. No. 14/054,572, Margomenos, et al., filed Oct. 2013. |
U.S. Appl. No. 14/080,691, Margomenos, et al., filed Nov. 2013. |
U.S. Appl. No. 14/703,545, Margomenos, et al., filed May 2015. |
U.S. Appl. No. 14/720,619, Herrault, et al., filed May 2015. |
U.S. Appl. No. 14/286,923, Margomenos et al, filed May 2014. |
U.S. Appl. No. 14/532,761, Herrault et al, filed Nov. 2014. |
Requirement for Restriction issued for U.S. Appl. No. 14/720,619 dated Sep. 28, 2015. |
Notice of Allowance issued for U.S. Appl. No. 14/720,619 dated Feb. 24, 2016. |
Non-final Office Action issued for U.S. Appl. No. 15/169,591 dated Dec. 2, 2016. |
Requirement for Restriction issued for U.S. Appl. No. 13/306,827 dated Jan. 9, 2013. |
Non-final Office Action issued for U.S. Appl. No. 13/306,827 dated Mar. 7, 2013. |
Notice of Allowance issued for U.S. Appl. No. 13/306,827 dated Aug. 15, 2013. |
Requirement for Restriction issued for U.S. Appl. No. 14/054,572 dated Jul. 10, 2014. |
Non-final Office Action issued for U.S. Appl. No. 14/054,572 dated Sep. 19, 2014. |
Notice of Allowance issued for U.S. Appl. No. 14/054,572 dated Feb. 12, 2015. |
Requirement for Restriction issued for U.S. Appl. No. 14/080,691 dated Dec. 17, 2014. |
Non-final Office Action issued for U.S. Appl. No. 14/080,691 dated Apr. 16, 2015. |
Notice of Allowance issued for U.S. Appl. No. 14/080,691 dated Aug. 12, 2015. |
Non-final Office Action issued for U.S. Appl. No. 14/286,923 dated Nov. 1, 2016. |
Non-final Office Action issued for U.S. Appl. No. 14/703,545 dated Dec. 15, 2015. |
Final Office Action issued for U.S. Appl. No. 14/703,545 dated May 24, 2016. |
Non-final Office Action issued for U.S. Appl. No. 14/703,545 dated Oct. 3, 2016. |
Chen, K. C., et al., “Thermal Management and Novel Package Design of High Power Light Emitting Diodes,” National Cheng Kung University, Taiwan, 2008 Electronic Components and Technology Conference, pp. 795-797, (May 2008). |
Feeler, R., et al., “Next-Generation Microchannel Coolers,” Northrop Grumman, Proceedings of SPIE, vol. 6876, pp. 687608-1-687608-8, (2008). |
Herrault F. et al., “Silicon-Packaged GaN Power HEMTs with Integrated Heat Spreaders,” Electronic Components and Technology Conference (ECTC), 2015 IEEE 65.sup.th, Conference: (May 26 to May 29, 2015). |
Margomenos A. et al., “Novel Packaging, Cooling and Interconnection Method for GaN High Performance Power Amplifiers and GaN Based RF Front-Ends,” Proceedings of the 7.sup.th European Microwave Integrated Circuits Conference, pp. 615-618, (Oct. 29-30, 2012). |
Margomenos, A. et al., “Wafer-Level Packaging Method Incorporating Embedded Thermal Management for GaN-Based Rf Front-Ends,” IEEE Intersociety Conference on Therman and Thermomechanical Phenomena in Electronic Systems (ITHERM), May 27-30, 2014 in Orlando, Florida. |
Margomenos, A. et al., “X-Band Highly Efficient GaN Power Amplifier Utilizing Built-In Electroformed Heat Sinks for Advanced Thermal Management,” IEEE International Microwave Symposium, pp. 1-4, (Jun. 2-7, 2013). |
P. Chang-Chien et al., “MMIC Packaging and Heterogeneous Integration Using Wafer-Scale Assembly,” CS Mantech Conference, pp. 143-146, (May 14-17, 2007). |
Notice of Allowance issued for U.S. Appl. No. 14/950,667(now U.S. Pat. No. 9,508,652) dated Aug. 2, 2016. |
Non-final Office Action issued for U.S. Appl. No. 14/532,761 dated Oct. 6, 2015. |
Notice of Allowance issued for U.S. Appl. No. 14/532,761(now U.S. Pat. No. 9,337,124) dated Jan. 15, 2016. |
From U.S. Appl. No. 14/286,923 (unpublished; non-publication requested) Final Office Action dated May 17, 2017. |
Woo et al, “Effects of Various Metal Seed Layers on the Surface Morphology and Structural Composition of the Electroplated Copper Layer”, Apr. 2009, Metals and Materials International, vol. 15, No. 2, pp. 293-297. |
Number | Date | Country | |
---|---|---|---|
62244659 | Oct 2015 | US |