SiPs in the medical domain and in the defense and industrial domain produced with WDoDTM technology

2015 ◽  
Vol 2015 (DPC) ◽  
pp. 000143-000181
Author(s):  
Pascal COUDERC ◽  
Jérôme NOIRAY

Based on Wire free Die on Die disruptive technology (WDoDTM), complex SiPs can be manufactured in a small factor package size. Stacking known good rebuilt wafers allows high yields while integrating high performance devices (1). Wafer processing is done with e-WLB technology and a specific redistribution layer (RDL) is designed to match with 3D PLUS bus metal edge interconnect technology. 300 mm rebuilt wafers are processed and thinned down to 200 μm before stacking and polymer bonding. Bonding alignment is within ±5 μm allowing small lateral pitches demonstrating WDoDTM versatility with denser IO products such as FPGA. Besides, this new process integration scheme allows the stacking of both conventional boards with SMDs not available at wafer level together with rebuilt wafers made of known good dies. WDoDTM technology has been successfully used with different kind of products in the defense and medical markets. A calculator node including a 484 I/O FPGA with 2 mDDR and an EEPROM in addition to more than 150 decoupling capacitors was manufactured and is exhibiting better electrical performance when compared to the 2 dimensions version. Moreover, a medical implant has been successfully developed embedding 2 ASICS and several PICS capacitors allowing an 8 times shrink of the electronics compared to advance lead based pacemakers.. With this new technology, 3D PLUS is highlighting the way to highly integrated System in Package (SiP) and demonstrates its know-how in the three dimensional integration.

2012 ◽  
Vol 2012 (1) ◽  
pp. 000148-000153
Author(s):  
Karl Malachowski ◽  
Karen Qian ◽  
Maaike Op de Beeck ◽  
Rita Verbeeck ◽  
George Bryce ◽  
...  

Material selection is the key issue when developing a biocompatible packaging process for implantable electronic systems. To secure a reliable performance of the chip in such a package, its encapsulation has to be considered up-front in the wafer-level integration scheme. A differentiation of two main material types can be made:1) Insulating or passive materials functioning as a bi-directional diffusion barrier preventing body fluids leaking into the package causing systems malfunction due to possible materials corrosion and also avoiding a leakage of built-in materials to the in-vivo environment and2) Conductive or active materials as diffusion barriers, e.g. against copper diffusion or as direct external contacts responsible for electrical performance of the system. This study investigates the properties of two widely used insulating materials in the semiconductor industry, the nitride and the oxide. Both material types are deposited in a PECVD system using different temperatures; 400 ° C for CMOS compatibility and 200 ° C for wafer back side process integration when a temporary carrier system is used. The biocompatibility investigations of these materials (evaluated using cell lines and primary cells) show promising results. However, for the long term application, the stability results for the oxide layers show hydration effects resulting in material degradation where the nitride layers clearly show corrosion and are even etched when elevated temperatures are applied. This fact is surprising since nitride layers are widely used as a humidity barrier for various chip types but obviously not suitable for a direct contact with liquids. Various analysis methods using e.g. Fourier Transformed IR Spectroscopy or mass measurements substantiate this thesis.


2014 ◽  
Vol 2014 (1) ◽  
pp. 000599-000605 ◽  
Author(s):  
Woon-Seong Kwon ◽  
Suresh Ramalingam ◽  
Xin Wu ◽  
Liam Madden ◽  
C. Y. Huang ◽  
...  

This paper introduces the first comprehensive demonstration of new disruptive innovation technology comprising multiple Xilinx patent-pending innovations for highly cost effective and high performance Xilinx FPGA, which is so called stack silicon-less interconnect technology (SLIT) that provides the equivalent high-bandwidth connectivity and routing design-rule as stack silicon interconnect (SSI) technology at a cost-effective manner. We have successfully demonstrated the overall process integration and functions of our new SLIT-employed package using Virtex® -7 2000T FPGA product. Chip-to-Wafer stacking, wafer level flux cleaning, micro-bump underfilling, mold encapsulation are newly developed. Of all technology elements, both full silicon etching with high etch selectivity to dielectric/fast etch rate and wafer warpage management after full silicon etching are most crucial elements to realize the SLIT technology. In order to manage the wafer warpage after full Si removal, a couple of knobs are identified and employed such as top reinforcement layer, micro-bump underfill properties tuning, die thickness/die-to-die space/total thickness adjustments. It's also discussed in the paper how the wafer warpage behaves and how the wafer warpge is managed. New SLIT module shows excellent warpage characteristics of only −30 μm ~ −40 μm at room temperature for 25 mm × 31 mm in size and +20 μm ~ +25 μm at reflow temperature. Thermal simulation results shows that thermal resistance of new SLIT package is almost comparable to that of standard 2000T FCBGA package using TSV interposer with standard heat sink configuration and air wind condition. The reliability assessment is now under the study.


2015 ◽  
Vol 12 (3) ◽  
pp. 111-117
Author(s):  
Woon-Seong Kwon ◽  
Suresh Ramalingam ◽  
Xin Wu ◽  
Liam Madden ◽  
C. Y. Huang ◽  
...  

This article introduces the first comprehensive demonstration of new innovative technology comprising multiple key technologies for highly cost-effective and high-performance Xilinx field programmable gate array (FPGA), which is so-called stack silicon-less interconnect technology (SLIT) that provides the equivalent high-bandwidth connectivity and routing design-rule as stack silicon interconnect (SSI) technology at a cost-effective manner. We have successfully demonstrated the overall process integration and functions of our new SLIT-employed package using Virtex®-7 2000T FPGA product with chip-to-wafer stacking, wafer-level flux cleaning, microbump underfilling, mold encapsulation, and backside silicon removal. Of all technology elements, both full silicon removal process with faster etching and no dielectric layer damage and wafer warpage management after full silicon etching are most crucial elements to realize the SLIT technology. To manage the wafer warpage after full Si removal, a couple of knobs are identified and used such as top reinforcement layer, microbump underfill properties tuning, die thickness, die-to-die space, and total thickness adjustments. It is also discussed in the article how the wafer warpage behaves and how the wafer warpage is managed. New SLIT module shows excellent warpage characteristics of only −30 μm ∼ −40 μm at room temperature (25°C) for 25 mm × 31 mm in size and +20 μm ∼ +25 μm at reflow temperature (250°C). Thermal simulation results shows that thermal resistance of new SLIT package is almost comparable to that of standard 2000T flip-chip ball grid array (FC-BGA) package using through silicon via interposer with standard heat sink configuration and air wind condition. The reliability assessment is now under the study.


2016 ◽  
Vol 2016 (1) ◽  
pp. 000305-000308
Author(s):  
Eoin O'Toole ◽  
Steffen Kroehnert ◽  
José Campos ◽  
Virgilio Barbosa ◽  
Leonor Dias

Abstract NANIUM's Fan-Out Wafer-Level Packaging technology WLFO (Wafer-Level Fan-Out) is based on embedded Wafer-Level Ball Grid Array technology eWLB of Infineon Technologies [1]. Since it′s invention almost 10 years ago, it became the leading technology for Fan-Out Wafer-Level packages. The WLFO technology is based upon the reconstitution of KGD (known good die) from incoming device wafer, independent of wafer diameter and material, to recon wafer format of active semiconductor dies or other active/passive components separated by mold compound applied through compression molding on a temporary mold carrier. The resulting recon wafer can be processed in standard wafer processing equipment. One of the challenges for the future of semiconductor packaging is reduction of the board level volume real estate occupied by each component. With the drive towards lower profile end user devices incorporating large display area and battery life the three dimensional space available for semiconductor packages is diminishing. It is well known that WLFO single die packaging but even more significant system integration enables the shrinkage of the XY footprint of the package through flexible very dense heterogeneous system-in-package integration [2]. But one of the disruptive advantages of the substrate-less WLFO technology is to also permit significant reduction of the overall package height (Z). A total package height for a BGA package including solder balls <500um and for a LGA package with solder land pads only <300um is achievable today, and further development towards even thinner packages is on the way.


2006 ◽  
Vol 970 ◽  
Author(s):  
Ronald J. Gutmann ◽  
J. Jay McMahon ◽  
Jian-Qiang Lu

ABSTRACTA monolithic, wafer-level three-dimensional (3D) technology platform is described that is compatible with next-generation wafer level packaging (WLP) processes. The platform combines the advantages of both (1) high bonding strength and adaptability to IC wafer topography variations with spin-on dielectric adhesive bonding and (2) process integration and via-area advantages of metal-metal bonding. A copper-benzocyclobutene (Cu-BCB) process is described that incorporates single-level damascene-patterned Cu vias with partially-cured BCB as the bonding adhesive layer. A demonstration vehicle consisting of a two-wafer stack of 2-4 μm diameter vias has shown the bondability of both Cu-to-Cu and BCB-to-BCB. Planarization conditions to achieve BCB-BCB bonding with low-resistance Cu-Cu contacts have been examined, with wafer-scale planarization requirements compared to other 3D platforms. Concerns about stress induced at the tantalum (Ta) liner-to-BCB interface resulting in partial delamination are discussed. While across-wafer uniformity has not been demonstrated, the viability of this WLP-compatible 3D platform has been shown.


2005 ◽  
Vol 867 ◽  
Author(s):  
J. J. McMahon ◽  
F. Niklaus ◽  
R. J. Kumar ◽  
J. Yu ◽  
J.Q. Lu ◽  
...  

AbstractWafer-level three dimensional (3D) IC technology offers the promise of decreasing RC delays by reducing long interconnect lines in high performance ICs. This paper focuses on a viafirst 3D IC platform, which utilizes a back-end-of-line (BEOL) compatible damascene-patterned layer of copper and Benzocyclobutene (BCB). This damascene-patterned copper/BCB serves as a redistribution layer between two fully fabricated wafer sets of ICs and offers the potential of high bonding strength and low contact resistance for inter-wafer interconnects between the wafer pair. The process would thus combine the electrical advantages of 3D technology using Cu-to-Cu bonding with the mechanical advantages of 3D technology using BCB-to-BCB bonding.In this work, partially cured BCB has been evaluated for copper damascene patterning using commercially available CMP slurries as a key process step for a via-first 3D process flow. BCB is spin-cast on 200 mm wafers and cured at temperatures ranging from 190°C to 250°C, providing a wide range of crosslink percentage. These films are evaluated for CMP removal rate, surface damage (surface scratching and embedded abrasives), and planarity with commercially available copper CMP slurries. Under baseline process parameters, erosion, and roughness changes are presented for single-level damascene test patterns. After wafers are bonded under controlled temperature and pressure, the bonding interface is inspected optically using glass-to-silicon bonded wafers, and the bond strength is evaluated by a razor blade test.


Author(s):  
Qi Zhu ◽  
Lunyu Ma ◽  
Suresh K. Sitaraman

As the rapid advances in IC design and fabrication continue to challenge and push the electronic packaging technology, in terms of fine pitch, high performance, low cost, and good reliability, compliant interconnects show great advantages for next-generation packaging. β-fly is designed as a compliant chip-to-substrate interconnect for performing wafer-level probing and for packaging without underfill. β-fly has good compliance in all directions to compensate the coefficient of thermal expansion (CTE) mismatch between the silicon die and an organic substrate. The fabrication of β-fly is similar to standard IC fabrication, and wafer-level packaging makes it cost effective. In this work, self-weight effect and stress distribution under planar displacement loading of β-fly is studied. The effect of geometry parameters on mechanical and electrical performance of β-fly is also studied. β-fly with thinner and narrower arcuate beams with larger radius and taller post is found to have better mechanical compliance. In addition to mechanical compliance, electrical characteristics of β-fly have also been studied in this work. However, it is found that structures with excellent mechanical compliance cannot have good electrical performance. Therefore, a trade off is needed for the design of β-fly. Response surface methodology and an optimization technique have been used to select the optimal β-fly structure parameters.


2016 ◽  
Vol 2016 (1) ◽  
pp. 000469-000474 ◽  
Author(s):  
Xiao Liu ◽  
Qi Wu ◽  
Dongshun Bai ◽  
Trevor Stanley ◽  
Alvin Lee ◽  
...  

Abstract Advanced wafer-level packaging (WLP) techniques, mainly driven by high performance applications in memory and mobile market, have been adopted for large-scale manufacturing in recent years. Temporary wafer bonding and debonding technology has been widely studied and developed over the last decade for use in various WLP technologies, such as package-on-package (PoP), fan-out integration, and 2.5-D and 3-D integration using through-silicon-via (TSV). Temporary bonding technology enables handling of thinned substrates (<100 μm), which can no longer self-support during backside processing and packaging. Moreover, some applications require the temporary bonding materials to withstand temperatures up to 250°C in high-vacuum conditions, and even up to 350°C or higher during the dopant activation step required for manufacturing power devices. Therefore, a simple yet effective temporary bonding process and material that can survive all the backside processes is highly desired. In this study, a series of formulations based on polar thermoplastics were developed for temporary wafer bonding applications. These materials target high temperature survivability and improved adhesion to prevent the premature delamination during downstream wafer processing. All of these materials provide high thermal stability up to 250°C or higher, and are able to be bonded to carrier wafers treated with release layers, which can be selectively debonded by either mechanical or laser release after backside processing. The material left on device wafer after debonding can be easily cleaned using common industrial solvents. Wafers bonded with these materials demonstrate lower overall stack total thickness variation (TTV < 5 μm) after grinding and have successfully passed a 200°C PECVD process without any delamination during grinding and PECVD processes.


Author(s):  
Caleb Serafy ◽  
Ankur Srivastava ◽  
Avram Bar-Cohen ◽  
Donald Yeung

Three-dimensional integration (3D IC) is a new technology that shows great potential for high performance and energy efficiency. However past work has shown that 3D ICs suffer from serious thermal issues, and advanced cooling solutions such as micro-fluidic cooling are necessary to realize the true potential of these systems. The interactions between thermal, electrical and physical aspects of a 3D design with micro-fluidic cooling are substantial, and a comprehensive co-design approach to address them simultaneously is a must. Such co-design techniques are required throughout the design process, including during architectural design space exploration (DSE) in order to ensure that optimal design choices are not overlooked. In this paper we propose a DSE framework for 3D CPUs with micro-fluidic cooling that applies electro-thermal optimization techniques to the circuit layout and the heatsink design. By considering such physical optimization techniques we provide a more accurate view of a 3D architecture’s thermal and timing feasibility, as well as its performance and energy efficiency. Using our proposed thermo-electrical-physical co-design DSE framework we are able to improve performance by 1.54x and energy efficiency by 1.26x.


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