Lead-On-Chip Versus Chip-On-Lead Packages and Solder Failure Criteria

2000 ◽  
Vol 122 (3) ◽  
pp. 279-280 ◽  
Author(s):  
Boris Mirman
Keyword(s):  
Solder Joint ◽  
Failure Criteria ◽  
High Impact ◽  
Solder Joint Reliability ◽  
Joint Reliability ◽  
On Chip

High impact of peeling stresses on solder joint reliability, and how to account for these stresses in failure criteria, are discussed. [S1043-7398(00)00803-3]

Reflow Process Simulation for Dispersion Evaluation of Solder Joint Shape on Chip Component

2009 ◽  
Author(s):  
Kanji Takagi ◽  
Qiang Yu ◽  
Tadahiro Shibutani ◽  
Hiroki Miyauchi
Keyword(s):  
Surface Tension ◽  
Solder Joint ◽  
High Reliability ◽  
Electronic Components ◽  
Reflow Process ◽  
Solder Joint Reliability ◽  
Automotive Electronic ◽  
Joint Reliability ◽  
On Chip ◽  
Joint Shape

The miniaturization and high reliability for automotive electronic components has been strongly requested. Generally, electronic component and printed wiring board are connected using solder joint. The reliability of solder joint has widely dispersion. For the dispersion reduction of solder joint reliability, not only design factors but manufacturing factors should be optimized. The evaluation of manufacturing factors for solder joint reliability was very difficult by experimental evaluation alone. Therefore, the reflow process simulation was established. The simulation was reenacted soldering process on chip component, which was the most severe reliability in automotive electronic components. The novelty of simulation was the coupled analysis of flow and rigid for simulating self-alignment of chip component. In this simulation, contact angle and surface tension was very important factor. So, these characteristics were measured based on Spread test and Wetting balance tests using the specimens. In the result, the solder joint shape of analysis was agree with the one of specimens using the measured contact angle and surface tension. Next, the effect of manufacturing process dispersion for solder joint shape was evaluated. The factors were mount offset and length unbalance of electrodes on chip component. As a result, the mount offset was not affected solder joint shape of chip component until a certain level. Also, the unbalance of electrode of chip component was not almost affected for solder joint shape of chip component because a part was moved to the center of part by surface tension of solder joint. Finally, the relation between the estimated solder joint shape and fatigue life of solder joints is evaluated using crack propagation analysis based on Manson-Coffin’s law and Miner’s rule. When the value of mount offset was large, the crack propagation mode was changed and the fatigue life of solder joint was decreased. As mentioned above, it was able to evaluate the relation between manufacturing factors and solder joint reliability. Accordingly, this simulation was very useful for consideration on the miniaturization, high reliability and appropriate margin for design of electronic components.

Thermal Cycling Reliability Predictions for PBGA Assemblies That Include Aging Effects

2013 ◽  
Author(s):  
Mohammad Motalab ◽  
Muhannad Mustafa ◽  
Jeffrey C. Suhling ◽  
Jiawei Zhang ◽  
John Evans ◽  
...  
Keyword(s):  
Finite Element ◽  
Solder Joint ◽  
Thermal Cycling ◽  
Failure Criteria ◽  
Lead Free ◽  
Aging Effects ◽  
Solder Joint Reliability ◽  
Reliability Models ◽  
Joint Reliability ◽  
Free Solder

The microstructure, mechanical response, and failure behavior of lead free solder joints in electronic assemblies are constantly evolving when exposed to isothermal aging and/or thermal cycling environments. Traditional finite element based predictions for solder joint reliability during thermal cycling accelerated life testing are based on solder constitutive equations (e.g. Anand viscoplastic model) and failure models (e.g. energy dissipation per cycle model) that do not evolve with material aging. Thus, there will be significant errors in the calculations with lead free SAC alloys that illustrate dramatic aging phenomena. In this research, we have developed a new reliability prediction procedure that utilizes constitutive relations and failure criteria that incorporate aging effects, and then validated the new approach through correlation with thermal cycling accelerated life testing experimental data. As a part of this work, a revised set off Anand viscoplastic stress-strain relations for solder have been developed that included material parameters that evolve with the thermal history of the solder material. The effects of aging on the nine Anand model parameters have been determined as a function of aging temperature and aging time, and the revised Anand constitutive equations with evolving material parameters have been implemented in commercial finite element codes. In addition, new aging aware failure criteria have been developed based on fatigue data for lead free solder uniaxial specimens that were aged at elevated temperature for various durations prior to mechanical cycling. Using the measured fatigue data, mathematical expressions have been developed for the evolution of the solder fatigue failure criterion constants with aging, both for Coffin-Manson (strain-based) and Morrow-Darveaux (dissipated energy based) type fatigue criteria. Similar to the findings for mechanical/constitutive behavior, our results show that the failure data and associated fatigue models for solder joints are affected significantly by isothermal aging prior to cycling. After development of the tools needed to include aging effects in solder joint reliability models, we have then applied these approaches to predict reliability of PBGA components attached to FR-4 printed circuit boards that were subjected to thermal cycling. Finite element modeling was performed to predict the stress-strain histories during thermal cycling of both non-aged and aged PBGA assemblies, where the aging at constant temperature occurred before the assemblies were subjected to thermal cycling. The results from the finite element calculations were then combined with the aging aware fatigue models to estimate the reliability (cycles to failure) for the aged and non-aged assemblies. As expected, the predictions show significant degradations in the solder joint life for assemblies that had been pre-aged before thermal cycling. To validate our new reliability models, an extensive test matrix of thermal cycling reliability testing has been performed using a test vehicle incorporating several sizes of fine pitch PBGA daisy chain components. Before thermal cycling began, the assembled test boards were divided up into test groups that were subjected to several sets of aging conditions (preconditioning) including different aging temperatures (T = 25, 55, 85 and 125 C) and different aging times (no aging, and 6 and 12 months). After aging, the assemblies were subjected to thermal cycling (−40 to +125 C) until failure occurred. As with the finite element predictions, the Weibull data failure plots have demonstrated that the thermal cycling reliabilities of pre-aged assemblies were significantly less than those of non-aged assemblies. Good correlation was obtained between our new reliability modeling procedure that includes aging and the measured solder joint reliability data.

scholarly journals A Control-Chart-Based Method for Solder Joint Crack Detection

2014 ◽  
Vol 11 (3) ◽  
pp. 94-103 ◽  
Author(s):  
Jianbiao Pan
Keyword(s):  
Solder Joint ◽  
Control Chart ◽  
Failure Criterion ◽  
Crack Detection ◽  
Scientific Explanation ◽  
Failure Criteria ◽  
Time To Failure ◽  
Reliability Study ◽  
Solder Joint Reliability ◽  
Joint Reliability

Many researchers have used different failure criteria in published solder joint reliability studies. Since the reported time-to-failure would be different if different failure criteria were used, it would be difficult to compare the reported reliability life of solder joints from one study to another. The purpose of this study is to evaluate the effect of failure criteria on the reported thermal fatigue life and determine which failure criterion could detect failure sooner. First, the application of the control-chart-based method in a thermal cycling reliability study is described. The reported time-to-failure data were then compared based on four different failure criteria: a control-chart-based method, a 20% resistance increase from IPC-9701A, a resistance threshold of 500 Ω, and an infinite resistance. Over 3.5 GB resistance data measured by data loggers from a low-silver solder joint reliability study were analyzed. The results show that estimated time-to-failure based on the control-chart-based method is very similar to that when the IPC-9701A failure criterion is used. Both methods detected failure much earlier than the failure criterion of a resistance threshold of 500 Ω or an infinite resistance. A scientific explanation is made of why the 20% increase in IPC-9701A is a reasonable failure criterion and why the IPC-9701A and the control-chart-based method produced similar results. Three different stages in resistance change were identified: stable, crack, and open. The duration of the crack stage depends on the severity of the test conditions. It is recommend the control-chart-based method be used as the failure criterion because it not only monitors the average of resistance, but also monitors the dispersion of resistance in each thermal cycle over time.

Experimental evaluation of SnAgCu solder joint reliability in 100-μm pitch flip-chip assemblies

2014 ◽  
Vol 54 (5) ◽  
pp. 939-944 ◽  
Author(s):  
Ye Tian ◽  
Xi Liu ◽  
Justin Chow ◽  
Yi Ping Wu ◽  
Suresh K. Sitaraman
Keyword(s):  
Solder Joint ◽  
Experimental Evaluation ◽  
Flip Chip ◽  
Solder Joint Reliability ◽  
Snagcu Solder ◽  
Joint Reliability
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