(重慶大學(xué) 材料科學(xué)與工程學(xué)院，重慶 400044)
摘 要: 研究不同回流焊工藝下得到的球柵陣列(BGA)焊點(diǎn)在正弦振動(dòng)疲勞試驗(yàn)中的失效行為。借助掃描電鏡觀察在不同加熱因子下形成的Sn-Cu金屬間化合物的形態(tài)和厚度，運(yùn)用有限元模擬分析球柵陣列焊點(diǎn)在正弦振動(dòng)下的應(yīng)力集中和分布。結(jié)果表明：當(dāng)金屬間化合物層的形態(tài)和厚度不同時(shí)，裂紋的萌生和擴(kuò)展機(jī)理不同；隨著金屬間化合物層厚度的增加，焊點(diǎn)的振動(dòng)疲勞壽命先是緩慢提高，隨后急劇下降；當(dāng)金屬間化合物層的厚度為1.5~3.0 μm時(shí)，接頭的振動(dòng)疲勞壽命達(dá)到最大值。
關(guān)鍵字: 金屬間化合物；球柵陣列；振動(dòng)；疲勞壽命
（School of Materials Science and Engineering, Chongqing University, Chongqing 400044, China）
Abstract:The sinusoidal vibration failure behavior of ball grid array(BGA) solder joints reflowed with different temperature profiles was studied. The morphologies and thickness of Sn-Cu intermetallic compound (IMC) formed under diverse heating factor were observed by scanning electron microscopy. The stress concentration and distribution of BGA solder joints under the sinusoidal vibration were analyzed by finite element simulation. The results show that the origin and propagation of cracks mechanism differs when the morphologies and thickness of IMC layer are different. The vibration fatigue lifetime of solder joints increases gradually at first and then drops rapidly with the increase of the thickness of IMC layer, reaching the maximum when the thickness of IMC layer is about 1.5-3.0 μm.
Key words: intermetallic compound; ball grid array; vibration; fatigue lifetime
