波峰焊焊接框架变形问题的分析及解决方案

本文通过对普通环氧树脂玻璃纤维材料制作的波峰焊焊接框架的热变形问题分析，为用环氧树脂玻璃纤维板等普通材料替代昂贵的国外进口复合材料制作焊框架提出了一套切实可行的工艺方案。     

SOLDERING WITH DUCTILE ACTIVE SOLDERS

Ductile active solders enable production of the vacuum-tight joints of metals with such brittle nonmetallic materials as quartz, ceramics, silicon, and carbon. This article describes the techniques of the preparation of solders and the examples of the practical application of joints in the vacuum and cryogenic devices.     

细间距SMD焊接强度试验研究

通过对细间距SMD焊接强度试验 ,分析了影响焊接强度的诸多因素 ,找到适合SMT要求的焊膏、模板、焊膏量、温度曲线等系列工艺材料参数。     

Sequential interfacial intermetallic compound formation of Cu6Sn5 and Ni3Sn4 between Sn-Ag-Cu solder and ENEPIG substrate during a reflow process

The interfacial reactions between Sn-3.0 wt.% Ag-0.5 wt.% Cu solder and an electroless nickel-electroless palladium-immersion gold (ENEPIG) substrate were investigated. After initial reflowing, discontinuous polygonal-shape (Cu,Ni)₆Sn₅ intermetallic compounds (IMCs) formed at the interface. During reflowing for up to 60 min, the interfacial IMCs were sequentially changed in the following order: discontinuous (Cu,Ni)₆Sn₅, (Cu,Ni)₆Sn₅ and (Ni,Cu)₃Sn₄, and embedded (Cu,Ni)₆Sn₅ in (Ni,Cu)₃Sn₄. The interfacial product variation resulted from the preferential consumption of Cu atoms within the solder and continuous Ni diffusion from the Ni(P) layer.     

电力电容器不锈钢外壳搪锡工艺探讨

通过对不锈钢搪锡的特点分析,介绍了电容器不锈钢外壳套管孔搪锡使用的焊剂配制,提出了用磷酸代替盐酸配制新型焊剂的方法。     

晶体浸锡机的PLC控制系统

本文介绍了一个采用PLC-触摸屏电控系统的浸锡设备，并对设备工作过程及控制系统的软、硬件设计进行了详细分析。     

压铸模与铝铸件焊合区的特征及形成机理

模具焊合区的表面上,存在着一定数量的显微孔洞、显微凹陷及裂纹等表面缺陷,大大增加了模具与铸件间的真实接触面积,焊合区的截面主要由焊合的铝合金、过渡层、氮化层及钢基体组成。对模具与铸件不同的焊合模式及形成机理进行了分析,将焊合分为物理化学焊合、机械焊合和混合焊合,并分析了压铸生产中焊合的形成及扩展过程。     

Growth mechanisms of Cu3Sn on polycrystalline and single crystalline Cu substrates

A comprehensive transmission electron microscopy (TEM) study was conducted to investigate the growth mechanisms of Cu₃Sn on polycrystalline and single crystalline Cu substrates in solder joints. On single crystalline Cu the solder reflow process resulted in the growth of columnar Cu₃Sn grains aligned in a thin uniform layer perpendicular to the interface, while a thick Cu₃Sn layer formed from fine equiaxed grains on the polycrystalline substrate. In the subsequent solid state aging, columnar growth of Cu₃Sn continued on the single crystalline Cu before it was replaced by nucleation and growth of new triangular Cu₃Sn grains at the triple junction sites of the Cu/Cu₃Sn interface. On the polycrystalline Cu the solid state aging caused much more rapid growth of the Cu₃Sn layer due to nucleation and the growth of new Cu₃Sn grains at both the Cu/Cu₃Sn and Cu₆Sn₅/Cu₃Sn interfaces. These different growth behaviors of Cu₃Sn were related to the diffusive supply of reactive elements.     

Effect of TiO2 nanoparticles on the horizontal hardness properties of Sn-3.0Ag-0.5Cu-1.0TiO2 composite solder

The improvement in the hardness of Sn-3.0Ag-0.5Cu solder alloy reinforced with 1.0 wt % TiO₂ nanoparticles was evaluated by nanoindentation. A specific indentation array was performed on four different horizontal cross sections of the composite solder with different heights and diameters, in order to verify the mixing homogeneity of TiO₂ nanoparticles within the Sn-3.0Ag-0.5Cu solder paste during the ball milling process. The phase analysis indicated successful blending of the Sn-3.0Ag-0.5Cu with the TiO₂ nanoparticles. According the scanning electron microscopy micrographs, presence of the TiO₂ nanoparticles reduced the size of the Cu₆Sn₅ and Ag₃Sn intermetallic compound phases. Incorporation of the 1.0 wt % TiO₂ nanoparticles improved the hardness values up to 26.2% than that of pure SAC305. The hardness values increased gradually from the top cross sections towards adjacent to the solder/substrate interface. The mechanism of the hardness improvement attained by the TiO₂ nanoparticles addition were also investigated on the horizontal cross sections of the samples.