CPC基板表面阻焊层制备与阻焊效果研究

Study on the preparation and braze resist effect of mask layer on CPC substrate

为解决金属-陶瓷封装外壳底板和环框钎焊时焊料流淌不受控制问题,通过在底板上制备陶瓷阻焊层,实现了对焊料的阻挡,达到了精确控制焊料流淌区域的目的。采用扫描电镜对氮化铝和氧化铝两种阻焊层进行了研究和分析,结果表明:氮化铝阻焊层由柱状颗粒构成,颗粒之间尺寸差异性小,并且近似层状堆叠,组织结构比较松散、不致密,内部有孔隙和裂纹,容易被焊料渗透,阻焊效果不理想。与之相反,氧化铝形成的阻焊层由大小不等的块状颗粒构成,颗粒之间相互填充,形成的结构较致密,内部没有孔隙、裂纹等缺陷,可以很好地阻止焊料的渗透,阻焊效果明显优于氮化铝。

To address uncontrolled braze flow between bottom plate and ring frame of a metal ceramic package,a ceramic braze resist layer was used on the bottom plate during brazing to achieve accurately controlled braze flow area.Here,scanning electron microscopy(SEM)was used to study the braze resist layers of aluminum nitrides and oxides.The results show that the aluminum nitride braze resist layers are consisted of monodispersed columnar particles,which are similar to laminar structures.The microstructure is relatively loose and not dense with inside pores and cracks,making it easy penetrated by the braze.As a result,it is nonideal for braze resist layer.On the contrary,the alumina braze resist layer is composed of polydisperse particles,resulting in dense structures without pores and cracks for effectively braze penetration resist.Its braze resist effect is significantly better than that of alumina.