Influence of Glass Transition Temperature of Underfill on the Stress Behavior and Reliability of Microjoints Within a Chip Stacking Architecture

2015 ◽  
Vol 137 (3) ◽  
Author(s):  
Jing-Yao Chang ◽  
Shin-Yi Huang ◽  
Chang-Chun Lee ◽  
Tung-Han Chuang ◽  
Tao-Chih Chang
Keyword(s):  
Glass Transition ◽  
Temperature Cycling ◽  
Stress And Strain ◽  
Analysis Model ◽  
Ansys Software ◽  
Depletion Zone ◽  
Reliability Characteristics ◽  
Temperature Cycling Test ◽  
Capillary Type ◽  
Reliability Performance

In this study, the reliability performance of two capillary-type underfill materials with different glass transition temperatures (Tg) and coefficients of thermal expansion (CTE) were assessed for a chip stacking architecture. The microbumps for integrating four chips on a Si interposer were with a pitch size of 20 μm and composed of 5 μm Cu/3 μm Ni/5 μm Sn2.5Ag solder cap. A thermocompressive bonder was used to interconnect the microbumps at 280 °C for 15 s, and the microgaps between the chips and the interposer were then, respectively, sealed by the mentioned underfill materials to form a chip stacking architecture. Then, the reliability characteristics of the test vehicles were evaluated following the preconditioning and temperature cycling test (TCT). Furthermore, a numerical analysis model was established by ansys software to study the stress and strain contours of the microjoints sealed by different underfill materials. It was found that the lifetime of microjoints was highly related to the Tg points of underfills, an interfacial fracture was observed within the microjoints sealed by a lower Tg underfill after temperature cycling because the tensile strength damaged the Sn depletion zone as heated.

Fabrication and Reliability Assessment of Cu Pillar Micro-bumps with Printed Polymer Cores

2020 ◽  
Author(s):  
Xing QIU ◽  
Jeffery Lo ◽  
Yuanjie CHENG ◽  
Shi-Wei Ricky Lee ◽  
Yong Jhe TSENG ◽  
...  
Keyword(s):  
Flip Chip ◽  
Reliability Assessment ◽  
Temperature Cycling ◽  
Thermomechanical Stress ◽  
Joint Reliability ◽  
Cu Pillar ◽  
Bonding Technology ◽  
Temperature Cycling Test ◽  
Reliability Performance ◽  
Cycling Condition

Abstract Cu pillar micro-bumps with polymer cores have been demonstrated to effectively reduce thermomechanical stress and improve joint reliability. Fabricating polymer cores by a printing approach was proposed to overcome the limitations in conventional fabrication process. Cylindrical polymer cores with diameter of 20 µm and height of 30 µm were successfully printed. Surface metallization was subsequently applied on the printed polymer cores and Cu pillar micro-bumps with printed polymer cores with diameter of 35 µm and height of 35 µm were eventually achieved. To study the reliability performance of the interconnect joints made of Cu pillar micro-bumps with printed polymer cores, flip-chip bonding technology was successfully introduced and the interconnect joints between a designed BT substrate and a silicon chip were formed. The interconnect joints made of conventional Cu pillars with identical dimensions were prepared for comparison. The reliability performance of the joints was investigated under temperature cycling condition and drop condition, respectively. Printed polymer cores increased the characteristic life by 32% in a temperature cycling test (0°C-100°C), while the drop test showed that printed polymer cores increased the characteristic life by 4 times due to the extra compliance provided by the printed polymer cores. It can be concluded that Cu pillar micro-bumps with printed polymer cores can effectively reduce stress and improve joint reliability.

Temperature Characteristics of Li-Ion Batteries

2014 ◽  
Vol 1008-1009 ◽  
pp. 274-276
Author(s):  
Hong Wei Wang ◽  
Zi Qiang Tao ◽  
Yan Ling Fu ◽  
Hong Bai ◽  
Hai Qing Xiao
Keyword(s):  
Temperature Cycling ◽  
Safety Performance ◽  
Quality And Safety ◽  
Li Ion Batteries ◽  
Temperature Characteristics ◽  
Cycling Test ◽  
Li Ion ◽  
Temperature Cycling Test

Two kinds of import laptop battery and one kind of domestic laptop battery were investigated in the temperature cycling test. The results showed that all the samples didn’t fire, explosion and leakage in the temperature cycling tests. But the shell glue of domestic laptop battery was disabled more serious then that of import laptop battery and it still exist some security risk.Therefore, There is a long way to go to investigate and improve the quality and safety performance of some laptop battery.

scholarly journals FCCSP IMC growth under reliability stress follows automotive criteria

2019 ◽  
Vol 3 (1) ◽  
pp. 70-83
Author(s):  
Wei Wei Liu ◽  
Berdy Weng ◽  
Scott Chen
Keyword(s):  
High Temperature ◽  
Flip Chip ◽  
Stress Test ◽  
Temperature Cycling ◽  
Content Type ◽  
Initial Stage ◽  
High Temperature Storage ◽  
Temperature Cycling Test ◽  
Temperature Storage

Purpose The Kirkendall void had been a well-known issue for long-term reliability of semiconductor interconnects; while even the KVs exist at the interfaces of Cu and Sn, it may still be able to pass the condition of unbias long-term reliability testing, especially for 2,000 cycles of temperature cycling test and 2,000 h of high temperature storage. A large number of KVs were observed after 200 cycles of temperature cycling test at the intermetallic Cu3Sn layer which locate between the intermetallic Cu6Sn5 and Cu layers. These kinds of voids will grow proportional with the aging time at the initial stage. This paper aims to compare various IMC thickness as a function of stress test, the Cu3Sn and Cu6Sn5 do affected seriously by heat, but Ni3Sn4 is not affected by heat or moisture. Design/methodology/approach The package is the design in the flip chip-chip scale package with bumping process and assembly. The package was put in reliability stress test that followed AEC-Q100 automotive criteria and recorded the IMC growing morphology. Findings The Cu6Sn5 intermetallic compound is the most sensitive to continuous heat which grows from 3 to 10 µm at high temperature storage 2,000 h testing, and the second is Cu3Sn IMC. Cu6Sn5 IMC will convert to Cu3Sn IMC at initial stage, and then Kirkendall void will be found at the interface of Cu and Cu3Sn IMC, which has quality concerning issue if the void’s density grows up. The first phase to form and grow into observable thickness for Ni and lead-free interface is Ni3Sn4 IMC, and the thickness has little relationship to the environmental stress, as no IMC thickness variation between TCT, uHAST and HTSL stress test. The more the Sn exists, the thicker Ni3Sn4 IMC will be derived from this experimental finding compare the Cu/Ni/SnAg cell and Ni/SnAg cell. Research limitations/implications The research found that FCCSP can pass automotive criteria that follow AEC-Q100, which give the confidence for upgrading the package type with higher efficiency and complexities of the pin design. Practical implications This result will impact to the future automotive package, how to choose the best package methodology and what is the way to do the package. The authors can understand the tolerance for the kind of flip chip package, and the bump structure is then applied for high-end technology. Originality/value The overall three kinds of bump structures, Cu/Ni/SnAg, Cu/SnAg and Ni/SnAg, were taken into consideration, and the IMC growing morphology had been recorded. Also, the IMC had changed during the environmental stress, and KV formation was reserved.

Evaluation of Polymer Core Solderballs for Wafer Level Reliability Improvements

2014 ◽  
Vol 2014 (DPC) ◽  
pp. 000545-000566
Author(s):  
John Hunt ◽  
Adren Hsieh ◽  
Eddie Tsai ◽  
Chienfan Chen ◽  
Tsaiying Wang
Keyword(s):  
Temperature Cycling ◽  
Wafer Level ◽  
Development Activity ◽  
Wafer Level Packaging ◽  
First Case ◽  
Mask Design ◽  
To Come ◽  
And Performance ◽  
Reliability Performance ◽  
The Impact

Nearly half a century ago the first die bumping was developed by IBM that would later enable what we call Wafer Level Packaging. It took nearly 40 years for Wafer Level Chip Scale Packaging (WLCSP), with all of the “packaging” done while still in wafer form to come into volume production. It began with very small packages having solderball counts of 2–6 I/Os. Over the years, the I/O count has grown, but much of the industry perception has remained that WLCSPs are limited to low I/O count, low power applications. But within the last few years, there have been growing demands for WLCSP packages to expand into applications with higher levels of complexity. With the ever increasing density and performance requirements for components in mobile electronic systems, the need has developed for an expansion of applicability for Wafer Level Package (WLP) technology. Wafer Level packaging has demonstrated a higher level of component density and functionality than has been traditionally available using standard packaging. This has led to the development of WLCSPs with larger die and increasing solderball connectivity counts. Development activity has been ongoing for improved materials and structures to achieve the required reliability performance for these larger die. For this study, we have evaluated several different metallic structures used for polymer core solderballs with two different WLCSP structures. The WLCSP structures which were evaluated included a standard 4-mask design with redistribution layer (RDL), using a Polymer 1, Metal RDL, Polymer2, and Under Bump Metallization (UBM); as well as a 3-mask design with RDL, using a Polymer 1, Metal RDL, and Polymer 2. In the first case, the solderballs are bonded to the UBM, while in the second case the balls are bonded to the RDL, using the Polymer 2 layer as the solder wettable defining layer. All of the combinations are tested using the standard JEDEC Temperature Cycling on Board (TCOB) and Drop Test (DT) methodologies. The two different metallurgies of the polymer core solderballs appear to react differently to the two different WLCSP structures. This suggests that the polymer core solderball compositions may perform best when optimized for the specific WLCSP structures that are manufactured. We will review the results of the impact of the different polymer core metallurgies on the TCOB and DT reliability performance of the WLCSPs, showing the interactions of these materials with the two WLCSP structures.

scholarly journals Finite Element Failure Analysis of GFRP Laminates in Plate-Cone Reticulated Shell

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Xing Wang ◽  
Yu Jiang ◽  
Yonghui Huang ◽  
Yue Huang ◽  
Fan Wang
Keyword(s):  
Failure Analysis ◽  
Composite Laminates ◽  
Strength Criterion ◽  
Laminated Plates ◽  
Engineering Practice ◽  
Analysis Model ◽  
Ansys Software ◽  
Strength Failure ◽  
New Type ◽  
Element Failure

Plate-cone reticulated shell is a new type of spatial structures with good mechanical behavior, technical economy, and architectural appearance. In this paper, using ANSYS software, the strength failure analysis model of composite laminates is established in cooperation with the Strength Criterion of Hoffman. The effects of layer number, laying direction, and thickness of laminates on the ultimate strength of laminates are studied by detailed parametric analysis, which provides a theoretical basis for the design of composite plate-cone reticulated shell and GFRP laminated plates. Some important conclusions are obtained and can be applied to engineering practice.

Effect of Coconut Oil and Surfactants on Stability of Nanoemulsions

2012 ◽  
Vol 506 ◽  
pp. 429-432 ◽  
Author(s):  
Suchada Piriyaprasarth ◽  
Pornsak Sriamornsak ◽  
Gaysorn Chansiri ◽  
W. Promboot ◽  
U. Imerb ◽  
...  
Keyword(s):  
Castor Oil ◽  
Coconut Oil ◽  
Temperature Cycling ◽  
Polysorbate 80 ◽  
Sorbitan Monooleate ◽  
Polyethylene Glycol 400 ◽  
Polysorbate 20 ◽  
Temperature Cycling Test ◽  
The Stability ◽  
Oil Sunflower

The objective of this study was to investigate the effect of coconut oil and different surfactants on stability of nanoemulsions that were prepared by simple homogenization (13,500 rpm, 10 minutes). Coconut oil, sunflower oil and castor oil at the concentration of 20-40% w/w were used as the oil phase. Polysorbate 20, polysorbate 80 and Cremophore RH40 were used as surfactant whereas sorbitan monooleate and polyethylene glycol 400 were used as co-surfactants. The formulations containing coconut oil in the range of 20-40% w/w and the ratio of polysorbate 80 to sorbitan monooleate of 2:1 and 3:1 provided nanosized emulsions (100-500 nm). The zeta potential values ranged from-41.51 to-16.97 mV. The prepared nanoemulsions were stable for at least 7 days at 8 °C. The temperature cycling test (storage at 4 °C for 24 hours and at 45 °C for 24 hours) was performed. It was found that the formulation containing 30% w/w of coconut oil, 22.5% w/w of polysorbate 80 and 7.5% w/w of sorbitan monooleate was stable for 1 cycle. The results indicated that a decrease in the concentration of surfactant and an increase in the concentration of oil affected the stability of nanoemulsions.

Fiber alignment shift in temperature cycling test

1998 ◽  
Author(s):  
Yih-Cheng Sheu ◽  
Cheng-Huang Chen ◽  
Chy-Pen Chien ◽  
Jao-Hwa Kuang ◽  
Wood-Hi Cheng ◽  
...  
Keyword(s):  
Temperature Cycling ◽  
Fiber Alignment ◽  
Cycling Test ◽  
Temperature Cycling Test
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