die mismatch 中文意思是什麼
die mismatch
解釋
模錯位-
However, the die attach layer delaminated after 500 cycles and pcb cracked in the underfilled samples after long time cycling. c - sam is employed to investigate the delamination in the underfilled samples. highly concentrated stress - strain induced by the cte mismatch between the bga component and the pcb board, coarsened grain and two kinds of intermetallic compounds ( nisn / nisns ) which formed during reflow and thermal cycle and their impact on the reliability of solder joints are discussed in this paper
充膠樣品粗化尤為嚴重; ? ni - sn金屬間化合物包括兩層:其中,靠近ni焊盤的那層比較平整,同時, eds結果分析表明其化學式近似為nisn ,而靠近焊料的那層呈板條狀,化學式近似為nisn _ 3 ,文獻表明其為亞穩相; ?充膠使得樣品最大應力范圍降了接近一個數量級並降低了dnp的作用,同時,器件失效模式變為晶元粘接層分層; ? c - sam結果表明本論文採用的充膠樣品,晶元粘接層分層起始於500周左右,而經過2700周循環的樣品,分層幾乎擴展到整個界面。
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