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一、前言一般认为影响铜芯引线可焊性的因素主要有二个方面①是铜锡合金层(η相)的扩散生长,②是镀层表面氧化物的生成。为了提高元器件引线的可焊性,文献曾报道采用中间加阻挡层的组合镀层取得了良好的效果。本文研究了几种组合镀层对可焊性的影响。即在铜基底上电镀可作为阻挡层的中间镀层,然后镀覆光亮锡镀层。中间镀层分别采用暗镍、低pb—Sn(即含pb量<40％重量的pb—Sn合金)和高pb—Sn(即含pb>60％重量的pb—Sn合金)三种镀层。中间镀层厚度控制在3～4μm,光亮锡镀层7～6μm,总厚度控制在10μm左右。另外一组作对照的试验样品是在铜基体直接镀光亮锡(10μm左右),无中间阻挡镀层。每组样品都分
I. Preface It is generally believed that the factors that affect the solderability of the copper wire lead mainly in two aspects: ① the diffusion growth of the copper-tin alloy layer (η phase), and ② the formation of oxide on the surface of the coating. In order to improve the solderability of the component leads, it has been reported in the literature that the combination of the intermediate and barrier layers has achieved good results. This article studies the effects of several combinations of coatings on solderability. That is, a copper plating can be used as a barrier intermediate plating layer, and then coated bright tin plating. The middle plating uses three kinds of coating of dark nickel, low pb-Sn (ie pb-Sn alloy containing pb <40% by weight) and high pb-Sn (ie pb-Sn alloy containing pb> 60% The middle of the coating thickness control in 3 ~ 4μm, bright tin coating 7 ~ 6μm, the total thickness of about 10μm. Another group of control samples for the test is directly coated on the copper substrate bright tin (about 10μm), without intermediate barrier coating. Each sample is divided