In surface mount technology, development toward green manufacturing by converting all leaded soldering processes to lead free soldering process has created a lot of challenges mainly in wave soldering process which led to copper dissolution to assemble board causing it to be scrapped if not contained. The paper aims to propose a workable and practical solution to reduce extensive copper dissolution in assemble board and expand the cycle of allowable rework in assemble board. The work was carried out using Six Sigma methodology with defining the problem and research goals, measure the details in various aspects of current process, analyse data to identify potential root cause in a process, improve the process and control the process through experimental approaches. Main factors contributing to copper dissolution were identified and analysed. Total of five factors were identified namely the printed circuit board (PCB) finishing and copper layer construction in PCB, component terminal and led finishing, soldering flux usage and solder alloy composition, environment control with the use of Nitrogen tunnelling and the last factor was on the process itself which was from the in-contact process with molten turbulence soldering or non-contact process with intrusive soldering. Combined controlled factors contributing to minimization of copper dissolution by reducing the direct contact time to molten solder with optimize solder alloy composition and process control was formulated. An increase of sixty percentage of boards with lower copper dissolution going through the lead free wave soldering and rework soldering were obtained, another forty percent reduction of board being scrapped were also obtained with boards going through the molten solder up to triple times.

在表面贴装技术中，将所有含铅焊接工艺转换为无铅焊接工艺向绿色制造的发展带来了许多挑战，主要是在波峰焊接工艺中，导致铜溶解到组装板上，如果不包含则将其报废。本文旨在提出一种可行且实用的解决方案，以减少组装板上大量铜的溶解，并延长组装板上允许返工的周期。该工作使用六西格码方法进行，定义了问题和研究目标，测量了当前流程各个方面的细节，分析了数据以找出流程中的潜在根本原因，改进了流程并通过实验方法控制了流程。确定和分析了造成铜溶解的主要因素。总共确定了五个因素，即印刷电路板（PCB）的精加工和PCB中的铜层构造，组件端子和LED的精加工，助焊剂的使用和焊料合金的成分，使用氮隧穿进行环境控制，最后一个因素是该过程本身来自熔融湍流钎焊的接触过程或侵入式钎焊的非接触过程。制定了综合控制因素，从而通过优化焊料合金成分和工艺控制来减少与熔融焊料的直接接触时间，从而最大程度地减少了铜的溶解。通过无铅波峰焊和返修焊接，增加了60％的铜溶解度较低的板，