(西北工業(yè)大學(xué) 理學(xué)院，西安 710129)
摘 要: 以甲基磺酸錫為鍍錫液的主鹽，采用Stoney鍍層應(yīng)力測(cè)試方法，以及錫晶須生長(zhǎng)趨勢(shì)評(píng)價(jià)標(biāo)準(zhǔn)(JEDEC標(biāo)準(zhǔn)JESD22A121.01)，研究了雙向脈沖電沉積參數(shù)對(duì)純錫鍍層拉應(yīng)力大小及其晶須生長(zhǎng)特性影響的規(guī)律。利用掃描電子顯微鏡(SEM)表征了錫鍍層晶須生長(zhǎng)前后的微觀(guān)形貌，優(yōu)選出了錫鍍層應(yīng)力低、錫晶須生長(zhǎng)趨勢(shì)小的雙向脈沖電沉積參數(shù)(平均電流密度為10 A/dm2，占空比為0.7，逆向脈沖系數(shù)為0.5，頻率為10 Hz)。結(jié)果表明，通過(guò)調(diào)控雙向脈沖參數(shù)，可控制純錫鍍層內(nèi)應(yīng)力的大小，進(jìn)而制備出可抑制錫晶須生長(zhǎng)的純錫鍍層。
關(guān)鍵字: 錫鍍層；雙向脈沖電沉積；內(nèi)應(yīng)力；錫晶須
（School of Science, Northwestern Polytechnical University, Xi''an 710129, China）
Abstract:The effects of bidirectional-pulse parameters on the tensile stress of the tin coatings and the growth characteristics of tin whisker were investigated, based on the bath containing tin methyl sulfonate as the main salt. The coating stress was evaluated using the Stoney method, and the tin whisker growth tendency was examined according to the JEDEC Standard (JESD22A121.01). The microstructure of tin coatings before and after the appearance of tin whisker were characterized using scanning electron microscope (SEM). On this basis, the optimal bidirectional-pulse tin electrodeposition parameters (average current density of 10 A/dm2, duty cycle of 0.7, reverse pulse coefficient of 0.5, frequency of 10 Hz) were revealed for the preparation of tin coatings with less stress and less tendency of tin whisker growth. The results show that tin coating capable of suppressing tin whisker growth can be prepared by controlling the internal stress of tin coating via adjusting the bidirectional-pulse parameters.
Key words: tin coating; bidirectional-pulse electrodeposition; internal stress; tin whisker
