第1页共113页编号：时间：2021年x月x日书山有路勤为径，学海无涯苦作舟页码：第1页共113页SMT整个工艺流程细讲一、SMT工艺流程简介.........................................................................................................4二、焊接材料..........................................................................................................................6锡膏..........................................................................................................................................6锡膏检验项目..................................................................................................................9锡膏保存，使用及环境要求...........................................................................................9助焊剂（FLUX）....................................................................................................................9焊锡：....................................................................................................................................11红胶........................................................................................................................................11洗板水....................................................................................................................................12三、钢网印刷制程规范.........................................................................................................13锡膏印刷机（丝印机）.........................................................................................................13SMT半自动印刷机(PT-250)作业规范.........................................................................13刮刀(squeegee)...............................................................................................................14真空支座........................................................................................................................14影响因素................................................................................................................................151．钢网/PCB精确对位：.............................................................................................152、消除钢网支撑架的厚度误差：...............................................................................153、消除PCB的翘曲：.................................................................................................164、印刷时刮刀的速度：.............................................................................................165、刮刀压力：............................................................................................................166、钢网/PCB分离：.....................................................................................................167、钢网清洗：............................................................................................................178、印刷方向：..............................................................................................................179、温度：......................................................................................................................1710、焊膏图形的印刷后检测：.....................................................................................17焊膏图形的缺陷类型及产生原因........................................................
