Experimental and numerical analyses were both adopted in the thesis. First, the BGA with three different solder ball components and pads, were investigated and their strength was affected by drop tests and thermal cycling test. Then the concept of numerical simulation to do the follow-up analysis was adopted. the relationships of stress, strain, and creep strain energy density were found.
The lead-free solder ball has better resistance to the drop test with lower silver content; on the contrary, it has better properties due to thermal cycling tests with higher silver content. In the drop test, the failure of solder ball were found obviously in the packages that near four corner of the test board, and concentrated in the diagonal screw holes. The failure of solder ball was distributed over the peripheral of the package in the middle cross section of test board. Comparing the different position of 15 packages due to drop test, the amount of failed solder balls showed that the package positions U3, U8, U13 was obviously fractured, and the situation of fracture was relatively slight in the positions of U1, U5, U6, U7, U9, U10, U11, U15.
In the fatigue life prediction of thermal cycling test, the simplified model of package in 45¢X direction was mostly close to the experimental data. After the except ion of the solder ball with failure mode A1, the major failure mode in drop test was mode B3. But the mode C was the majority of thermal cycling test. The structure and intensity of SMD play an important role on above experiments; the better choice of SMD can reduce the rate of failure mode A1, and improve the accuracy of the experiment.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0807107-163938 |
| Date | 07 August 2007 |
| Creators | Le, Ye-sung |
| Contributors | Yi-Shao Lai, Chang-Lin Yeh, Jen, Ming-Hwa R., Ming Chen |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | Cholon |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0807107-163938 |
| Rights | withheld, Copyright information available at source archive |
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