複合應力加速測試下電子連接器端子之可靠度評估

Abstract

本論文根據複合應力加速測試結果探討電子連接器端子的可靠度。一般而言，連接器端子在單一廣義應力加壓下，具有良好的抵抗力與高可靠度，但為能確切分析其失效模式與壽命分佈，需要設計適當的複合應力加速測試，此複合應力包含溫度、濕度、腐蝕氣體濃度、插拔次數與連接器本身的抗應力因子—鍍層厚度。在適當複合應力組配下完成各實驗後，本論文採用非線性迴歸分析，套用至相關加速模型，並依據可靠度理論分析實驗數據。若將連接器端子在正常環境作用下之壽命稱為正常壽命，分析結果顯示，正常壽命是在溫度393 K之加速環境作用下壽命的97.09 倍、在濕度90 %之加速環境作用下壽命的1.23倍、在插拔次數300次之加速環境作用下壽命的1.04倍、在腐蝕氣體倍率1.0之加速環境作用下壽命的1.72倍。此型連接器端子在正常環境作用下，如果鍍層厚度為50微英吋，則其平均壽命可達28.1年、標準差為10.5年；如果鍍層厚度調整為40微英吋，其平均壽命變為26.6年，標準差變為10.0年；如果調為30微英吋，則其平均壽命變為24.2年，標準差變為9.1年；調為20微英吋，平均壽命變為19.9年，標準差變為7.5年。

To understand the failure mode and the characteristics of life distribution of system or components of electronic products in a short time, accelerated test has become an important test in industry. Temperature, humidity, electricity voltage or the processing cycles stress are often the factors tested. In the traditional accelerated test, most of the generalized stress tests combine one or two elements. However, the research object of this dissertation, electronic connector pins, have already exhibit high reliability and great resistance to the simple environmental stress tests. In order to analyze their failure modes and the characteristics of life distribution more accurately, a multiple stress accelerated test is designed which includes factors such as temperature, humidity, density of mixed eroding gas, plugging and unplugging cycles, and plating thickness, latter of which has stress resistant capability itself. The methodology adopted here to analyze the experiment data is the nonlinear regression, based on reliability theory and applied to the accelerated model. If the life of connector pins under normal environment is defined as a normal life span. Research analysis shows that normal life span is 97.09 times more than the life span under the accelerated temperature 393 K condition, 1.23 times more under the accelerated humidity 90 % condition, 1.04 times more for plugging and unplugging cycles 300, and 1.72 times more under the accelerated eroding gas density 1.0, independently. The average life with plating thickness of 50 μ' in the regular environment is 28.1 years and its standard deviation is 10.5 years. 26.6 years of average life and 10.0 years of standard deviation are the data for plating thickness of 40 μ'. 24.2 years of average life and 9.1 years of standard deviation are shown for plating thickness of 30 μ'. 19.9 years of average life and 7.5 years of standard deviation are n for plating thickness of 20 μ'.