印刷電路板表面處理製程無鉛化對焊錫性的影響

Abstract

印刷電路板(PCB)是將各種不同功能的電子零件整合在一起的主要載體，沒有PCB的整合功能，電子零件將無法發揮預期的作用，而PCB與電子零件的整合需依靠銲錫來使電性連接，達成電性整合的目的，成為一個功能完整的電子系統。 從2006年6月歐盟的RoHS指令規定電子產品成分禁用鉛，這對電子產業界而言，無疑是一大衝擊，因為錫鉛銲錫的優異性能(高可靠度與低溫共晶點)，使其廣泛應用於各種電子產品焊接製程中，但因鉛對環境生態的影響較大，在環保意識高漲的今日，無鉛銲錫的使用已是無法抗拒的潮流。在電子產品各項性能中，焊錫性的優劣一直是表示可靠度的重要的指標，但焊錫性判定並不像其它性能指標可直接量測而得，並將之量化。 本研究中將PCB各種最終表面處理方式，使用沾錫天平做焊錫性測試，以最大沾錫力和最短反應時間來做為焊錫性優劣的比較。另外針對無鉛噴錫表面處理製程參數，應用田口實驗法(Taguchi Methods)概念及實驗設計，以最大沾錫力和最短反應時間作為評估製程的輸出回應，尋求最佳化的製程控制參數。 研究結果顯示PCB最終表面處理製程，以噴錫製程的銲錫性最佳(有鉛噴錫最佳，無鉛噴錫次之)，但無鉛噴錫製程有焊墊表面平整度較差及操作溫度較高的缺點。無鉛噴錫最佳參數實驗結果則顯示，噴錫操作參數對沾錫實驗中最大沾錫力有顯著的影響，但對於最短反應時間則改善不大，其主要原因可能為最短反應時間輸出回應的影響因子並非噴錫製程參數，而是在後續的插件製程參數。

The PCB (Printed Circuit Board) is mainly to integrate the electronics component of different functions together to Matrix. Without the PCB integration function, Electronics component will not develop an anticipant function. PCB and the integration of electronics component need to depend on a solder to make the electricity link, Reaching electricity the purpose of the integration, Becoming an electron system of function integrity. From the product composition of the provision electron of the RoHS command lead-free of June, 2006 EU, This command for electron industry field is Shocked doubtless, Because the tin-lead alloy have a excellent performance (high reliability and low Eutectic temperature) of the solder, Make it extensively in various electron product weld’s process, But lead's influence to environmental is huge, In today of upsurge in the environmental protection, The lead-free solder use is already flows that can't resist . In the electron product performances, The solderability assessed has been the important beacon which product’s reliability, It’s different of the solderability assessed there unlike other performance can be measurement and get digitize. This thesis assessed the solderability by the biggest wetting force and shortest wetting time of wetting balance test for each PCB final surface process. In addition for the lead-free hot air leveling process parameter, The Taguchi Methods and design of experiment were employed to determine parameter of optimization between the output of biggest wetting force and shortest wetting time, The results of this study shown that the best of solderability is hot air leveling process(solder of Pb/Sn is first and Lead-free time it) for PCB final surface process, But Defect of the hot air leveling process is pad surface poor leveling and operate temperature higher . Best parameter experiment's result of Lead-free hot air leveling process to then display, There have notable influence for wetting test in hot air leveling parameter of operation, But for the most short response time improve there is not greatly, It’s could be process parameter of hot air leveling not for the factor of influence for most short response time outputs a response probably, Not because but because at follow-up parameter of connector process.