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Thermal Shock and Drop Test Performance of Lead-free Assemblies with No-underfill and Corner-underfill
| Content Provider | Semantic Scholar |
|---|---|
| Author | Chheda, Bankeem V. Ramkumar, S. Manian Ghaffarian, Reza |
| Copyright Year | 2009 |
| Abstract | With ROHS compliance the transition to lead-free is inevitable. Several lead-free alloys are available in the market and its reliability has been the main concern. The results from this experimental research aims at making a comparison of different lead-free alloy combinations. Thermal shock and drop tests are a part of this experimental study. The test vehicle considered for this study contains a variety of components such as ultra chip scale package (UCSP), package on package (PoP), plastic grid array (PBGA-676 & 1156), very thin chip array BGA (CVBGA), thin small outline package (TSOP-40 & 48), dual row micro-lead frame (DRMLF), micro-lead frame (MLF-36 & 72), and chip resistors (0201, 0402, 0603). The scope of this paper is limited to the performance evaluation for area array packages only. Solder ball alloy combinations for the area array packages include SAC305, SAC405, SAC105 and SnAg. The solder paste used for assembly is SAC305 with Type 3 particle size. Three different PCB surface finishes, electroless nickel immersion gold (ENIG), SnPb hot air solder level (HASL), and immersion silver (ImAg) are used. Different solder ball alloys and surface finish combinations will provide good comparison data for investigating the assembly performance. Preliminary investigations have been carried out on PCB assemblies subjected to mechanical shock in the assoldered condition and also after 200 and 500 thermal shock cycles at -55 to 125C. The mechanical shock test was conducted by subjecting the assemblies to 30-drop cycles from a height of 3ft. After each drop cycle the daisy chains were checked for continuity for the solder joint evaluation. The number of drops for the first daisy chain failure is used in analyzing the performance of the solder joints. |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | http://www.smtnet.com/library/files/upload/thermal-shock-and-drop-test.pdf |
| Alternate Webpage(s) | http://www.circuitinsight.com/pdf/thermal_shock_and_drop_test_smta.pdf |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
