자동차 에어백용 플렉시블 충격센서 모듈의 솔더 접합부 피로수명 |
박지연1, 김미송1, 오철민1, 도상현2, 서종덕2, 김대근2, 홍원식1 |
1전자부품연구원 융복합전자소재연구센터 2(주)신영 기술연구소 |
Solder Joint Fatigue Life of Flexible Impact Sensor Module for Automotive Electronics |
Ji-Yeon Park1, Mi-Song Kim1, Chulmin Oh1, Sang Hyeon Do2, Jong Dock Seo2, Dae Keun Kim2, Won Sik Hong1 |
1Electronic Convergence Materials Research Center, Korea Electronics Technology Institute, Gyeonggi-do 13509, Republic of Korea 2Research & Development, Shin Young Co. Ltd., Gyeongsangbuk-do 38899, Republic of Korea |
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Received: 19 September 2016; Accepted: 19 October 2016. Published online: 6 April 2017. |
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ABSTRACT |
To improve the sensitivity of impact sensor modules for automotive air bag systems, we developed a flexible module. The impact sensor was soldered with Sn-3.0Ag-0.5Cu (SAC305) solder on a flexible printed circuit board (FPCB) with an organic solderability preservative (OSP) surface finish. Thermal shock (TS) is one of the test methods used to accelerate the degradation of solder joints. To evaluate the solder joint fatigue life of the proposed flexible impact sensor module experienced with/without TS, TS test was conducted from –40 to 90 ℃ with a dwell time of 10 min for 1000 cycles. Then, high cycle fatigue tests were sequentially performed at a force range from 0 N and 20 N with a 1 Hz frequency sine wave. From these results, we determined that the mean life and B10 life of the solder joint fatigue after 1000 TS cycles were 4188.9 and 1864.8 cycles, respectively. Finally, we found that the fatigue life of the solder joint decreased with increasing TS cycles due to the growth of Cu6Sn5 + Cu3Sn, the thickness and the dispersion of Ag3Sn at the solder joint and matrix. Even though the mean life and B10 life of the solder joint fatigue life were reduced by 60% and 13.8% respectively, compared to their initial values, we confirmed the feasibility of using the flexible modules for automobile air bag systems. |
Keywords:
fatigue life, solder joint, flexible, air bag, automotive electronics |
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