Processing and Memory Partitioning Enabled by Low Cost Flip-Chip Stacking

2019 ◽  
Author(s):  
Fabian Hopsch ◽  
Andy Heinig
Keyword(s):  
Flip Chip ◽  
Low Cost

Nonlinear-Time-Dependent Analysis of Micro Via-In-Pad Substrates for Solder Bumped Flip Chip Applications

2002 ◽  
Vol 124 (3) ◽  
pp. 205-211 ◽  
Author(s):  
John H. Lau ◽  
S. W. Ricky Lee ◽  
Stephen H. Pan ◽  
Chris Chang
Keyword(s):  
Cross Sections ◽  
Flip Chip ◽  
Printed Circuit Board ◽  
Low Cost ◽  
Circuit Board ◽  
Test Results ◽  
Pcb Assembly ◽  
Creep Analysis ◽  
Chip Scale Package ◽  
Time Dependent Analysis

An elasto-plastic-creep analysis of a low-cost micro via-in-pad (VIP) substrate for supporting a solder bumped flip chip in a chip scale package (CSP) format which is soldered onto a printed circuit board (PCB) is presented in this study. Emphasis is placed on the design, materials, and reliability of the micro VIP substrate and of the micro VIP CSP solder joints on PCB. The solder is assumed to obey Norton’s creep law. Cross-sections of samples are examined for a better understanding of the solder bump, CSP substrate redistribution, micro VIP, and solder joint. Also, the thermal cycling test results of the micro VIP CSP PCB assembly is presented.

Physical and Fuzzy Logic Modeling of a Flip-Chip Thermocompression Bonding Process

1993 ◽  
Vol 115 (1) ◽  
pp. 63-70 ◽  
Author(s):  
Sa-Yoon Kang ◽  
H. Xie ◽  
Y. C. Lee
Keyword(s):  
Fuzzy Logic ◽  
Flip Chip ◽  
Low Cost ◽  
Distribution Patterns ◽  
Logic Model ◽  
Physical Models ◽  
High Yield ◽  
Yield Model ◽  
Physical Yield ◽  
Fuzzy Logic Model

Flip-Chip connections using gold-to-gold, gold-to-aluminum, or gold-to-solder bondings or contacts enhanced by epoxy are low-cost alternatives to soldering. To assist their technology advancements, we have developed yield models for a representative assembly process with flip-chip, thermocompression bondings. Based on bonding mechanics, a physical yield model has been developed to characterize the process. Then, a fuzzy logic model has been established to improve the modeling’s accuracy by including experimental data. The physical yield model can predict the assembly yield as a function of forces and planarities of the end effector, bump height variations, bump geometries, mechanical properties corresponding to different materials and temperatures, and distribution patterns of bumps. Consistent with our experimental experience, the calculated force level for a high-yield process was around 3000 gmf for a 30-gold-bump chip with a bump diameter of 60 μm and a height of 50 μm. The fuzzy logic model can be trained and adjusted by the results of physical models and experiments. It correlates very well to the nonlinear relationships between the yield and the assembly parameters, and has a self-learning capability to update itself with new data. Such capabilities have been demonstrated by studying the bonding on a substrate with or without a compliant layer.

Understanding Mold Compound Behavior on Flip Chip QFN Packages

2018 ◽  
Vol 2018 (1) ◽  
pp. 000125-000128
Author(s):  
Ruby Ann M. Camenforte ◽  
Jason Colte ◽  
Richard Sumalinog ◽  
Sylvester Sanchez ◽  
Jaimal Williamson
Keyword(s):  
Thermal Performance ◽  
High Performance ◽  
Flip Chip ◽  
Low Cost ◽  
Semiconductor Industry ◽  
Gelation Time ◽  
Molding Process ◽  
Design Quality ◽  
Low Resistance ◽  
Die Attach

Abstract Overmolded Flip Chip Quad Flat No-lead (FCQFN) is a low cost flip chip on leadframe package where there is no need for underfill, and is compatible with Pb free or high Pb metallurgy. A robust leadframe design, quality solder joint formation and an excellent molding process are three factors needed to assemble a high performance FCQFN. It combines the best of both wirebonded QFN and wafer chip scale devices. For example, wafer chip scale has low resistance, but inadequate thermal performance (due to absence of thermal pad), whereas wirebonded QFN has good thermal performance (i.e., heat dissipated through conductive die attach material, through the pad and to the board) but higher resistance. Flip chip QFN combines both positive aspects – that is: low resistance and good thermals. One of the common defects for molded packages across the semiconductor industry is the occurrence of mold voiding as this can potentially affect the performance of a device. This paper will discuss how mold voiding is mitigated by understanding the mold compound behavior on flip chip QFN packages. Taking for example the turbulent mold flow observed on flip chip QFN causing mold voids. Mold compound material itself has a great contribution to mold voids, hence defining the correct attributes of the mold compound is critical. Altering the mold compound property to decrease the mold compound rheology is a key factor. This dynamic interaction between mold compound and flip chip QFN package configuration is the basis for a series of design of experiments using a full factorial matrix. Key investigation points are establishing balance in mold compound chemistry allowing flow between bump pitch, as well as the mold compound rheology, where gelation time has to be properly computed to allow flow across the leadframe. Understanding the flow-ability of mold compound for FCQFN, the speed of flow was optimized to check on its impact on mold voids. Mold airflow optimization is also needed to help fill in tighter bump spacing but vacuum-on time needs to be optimized as well.

Molding Recipe Study for MUF Solder Crack Improvement

2018 ◽  
Vol 2018 (1) ◽  
pp. 000121-000124
Author(s):  
Scott Chen ◽  
Leander Liang ◽  
Pallas Hsu ◽  
Tim Tsai ◽  
Mason Liang ◽  
...  
Keyword(s):  
Flip Chip ◽  
Low Cost ◽  
Flow Simulation ◽  
Test Vehicle ◽  
Chip Technology ◽  
Solder Bumps ◽  
Capillary Underfill ◽  
Mold Flow ◽  
Profile Reduction ◽  
Transfer Pressure

Abstract In recent years, flip chip technology becomes more and more important with benefits of thin package profile, reduction of package outline, and excellent electrical and thermal performance by connection of copper pillar bumps (CuP) or C4 solder bumps. In order to fill the die gap to prevent voids problem, two encapsulated solutions could be applied: capillary underfill (CUF) and molded underfill (MUF). In general comparison, CUF means to dispense underfill first to fill in die gap then proceed over-molding afterward; and MUF is directly fill under and above die by mold compound. The advantages of MUF solution are low cost and high throughput, however, it will suffer other assembly issues such as solder extrusion and solder crack, and might result in potential function failure. To form these kinds of defects, we suspected that solder will plastically deform under thermal stress treatment, which comes from unbalance mold transfer pressure and material expansion stress during thermal process. In this article, we have tried to investigate the mechanism of solder crack through molding recipe DOE (Design of Experiment) and mold flow simulation. The test vehicle is 12 × 12 mm2 FCCSP, with 6 × 5 mm2 die size. The bump type is copper pillar bump and pitch/size are 126 um and 35 × 60 um2, respectively. The molding recipe has been evaluated by cross section, and it revealed that molding transfer time and molding temperature are directions toward improvement of solder crack issue.

Creating Semiconductor Value through Advanced Package Technology

2016 ◽  
Vol 2016 (S1) ◽  
pp. S1-S46
Author(s):  
Ron Huemoeller
Keyword(s):  
Big Five ◽  
Flip Chip ◽  
Microelectromechanical Systems ◽  
Technology Innovation ◽  
Low Cost ◽  
Semiconductor Industry ◽  
Significant Shift ◽  
Wafer Level ◽  
Chip Scale Package ◽  
Advanced Packaging

Over the past few years, there has been a significant shift from PCs and notebooks to smartphones and tablets as drivers of advanced packaging innovation. In fact, the overall packaging industry is doing quite well today as a result, with solid growth expected to create a market value in excess of $30B USD by 2020. This is largely due to the technology innovation in the semiconductor industry continuing to march forward at an incredible pace, with silicon advancements in new node technologies continuing on one end of the spectrum and innovative packaging solutions coming forward on the other in a complementary fashion. The pace of innovation has quickened as has the investments required to bring such technologies to production. At the packaging level, the investments required to support the advancements in silicon miniaturization and heterogeneous integration have now reached well beyond $500M USD per year. Why has the investment to support technology innovation in the packaging community grown so much? One needs to look no further than the complexity of the most advanced package technologies being used today and coming into production over the next year. Advanced packaging technologies have increased in complexity over the years, transitioning from single to multi-die packaging, enabled by 3-dimensional integration, system-in-package (SiP), wafer-level packaging (WLP), 2.5D/3D technologies and creative approached to embedding die. These new innovative packaging technologies enable more functionality and offer higher levels of integration within the same package footprint, or even more so, in an intensely reduced footprint. In an industry segment that has grown accustomed to a multitude of package options, technology consolidation seems evident, producing “The Big Five” advanced packaging platforms. These include low-cost flip chip, wafer-level chip-scale package (WLCSP), microelectromechanical systems (MEMS), laminate-based advanced system-in-package (SiP) and wafer-based advanced SiP designs. This presentation will address ‘The Big Five’ packaging platforms and how they are adding value to the Semiconductor Industry.

Thermally Activated Bumping Process using Sn3.0Ag0.5Cu Solder Powder for Low-Cost Interposers

2013 ◽  
Vol 2013 (1) ◽  
pp. 000420-000423
Author(s):  
Kwang-Seong Choi ◽  
Ho-Eun Bae ◽  
Haksun Lee ◽  
Hyun-Cheol Bae ◽  
Yong-Sung Eom
Keyword(s):  
Screen Printing ◽  
Flip Chip ◽  
Solder Bump ◽  
Low Cost ◽  
Organic Substrate ◽  
Lead Free ◽  
Lead Free Solder ◽  
Thermally Activated ◽  
Fine Pitch ◽  
Free Solder

A novel bumping process using solder bump maker (SBM) is developed for fine-pitch flip chip bonding. It features maskless screen printing process with the result that a fine-pitch, low-cost, and lead-free solder-on-pad (SoP) technology can be easily implemented. The process includes two main steps: one is the thermally activated aggregation of solder powder on the metal pads on a substrate and the other is the reflow of the deposited powder on the pads. Only a small quantity of solder powder adjacent to the pads can join the first step, so a quite uniform SoP array on the substrate can be easily obtained regardless of the pad configurations. Through this process, an SoP array on an organic substrate with a pitch of 130 μm is, successfully, formed.

Wafer Level Assembly Technique Development for Fine Pitch Flip Chip 3D Die-to-Wafer Integration

2010 ◽  
Vol 2010 (1) ◽  
pp. 000548-000553
Author(s):  
Zhaozhi Li ◽  
Brian J. Lewis ◽  
Paul N. Houston ◽  
Daniel F. Baldwin ◽  
Eugene A. Stout ◽  
...  
Keyword(s):  
Flip Chip ◽  
Low Cost ◽  
Three Dimensional ◽  
Cost Effective ◽  
Market Demand ◽  
Wafer Level ◽  
Packaging Technology ◽  
Fine Pitch ◽  
3D Packaging ◽  
Assembly Technique

Three Dimensional (3D) Packaging has become an industry obsession as the market demand continues to grow toward higher packaging densities and smaller form factor. In the meanwhile, the 3D die-to-wafer (D2W) packaging structure is gaining popularity due to its high manufacturing throughput and low cost per package. In this paper, the development of the assembly process for a 3D die-to-wafer packaging technology, that leverages the wafer level assembly technique and flip chip process, is introduced. Research efforts were focused on the high-density flip chip wafer level assembly techniques, as well as the challenges, innovations and solutions associated with this type of 3D packaging technology. Processing challenges and innovations addressed include flip chip fluxing methods for very fine-pitch and small bump sizes; wafer level flip chip assembly program creation and yield improvements; and set up of the Pb-free reflow profile for the assembled wafer. 100% yield was achieved on the test vehicle wafer that has totally 1,876 flip chip dies assembled on it. This work has demonstrated that the flip chip 3D die-to-wafer packaging architecture can be processed with robust yield and high manufacturing throughput, and thus to be a cost effective, rapid time to market alternative to emerging 3D wafer level integration methodologies.

High Reliability Flip Chip Using Low CTE Laminate Substrates

2005 ◽  
Author(s):  
D. Scott Copeland ◽  
M. Kaysar Rahim ◽  
Jeffrey C. Suhling ◽  
Guoyun Tian ◽  
Pradeep Lall ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Thermal Cycling ◽  
Flip Chip ◽  
Experimental Testing ◽  
High Reliability ◽  
Low Cost ◽  
Substrate Material ◽  
Space Applications ◽  
Sandwich Construction ◽  
Test Chips

In this work, we report on our efforts to develop high reliability flip chip on laminate assemblies for deployment in harsh thermal cycling environments characteristic of ground and aerospace vehicles (e.g. −55 to 150 °C). Reliability enhancement has been achieved through the use of a novel low expansion, high stiffness, and relatively low cost laminate substrate material that virtually eliminates CTE mismatches between the silicon die and top layer PCB interconnect. The utilized laminate features a sandwich construction that contains standard FR-406 outer layers surrounding a low expansion high thermal conductivity carbon fiber-reinforced composite core (STABLCOR®). Through both experimental testing and modeling, we have demonstrated that robust flip chip assemblies can be produced that illustrate ultra-high solder joint reliability during thermal cycling and extremely low die stresses. Liquid to liquid thermal shock testing has been performed on test assemblies incorporating daisy chain test die, and piezoresistive test chips have been used to characterize temperature dependent die stresses. In both sets of experiments, results obtained using the hybrid PCB laminate with FR-406 outer layers and carbon fiber core have been compared to those obtained with more traditional glass-epoxy laminate substrates including FR-406 and NELCO 4000-13. Nonlinear finite element modeling results for the low expansion flip chip on laminate assemblies have been correlated with the experimental data. Unconstrained thermal expansion measurements have also been performed on the hybrid laminate materials using strain gages to demonstrate their low CTE characteristics. Other experimental testing has demonstrated that the new laminate successfully passes toxicity, flammability, and vacuum stability testing as required for pressurized and un-pressurized space applications.

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