论文部分内容阅读
一、前言 目前,取代原始手工焊接而发展起来的有高波峰焊接、钎焊、激光焊接和红外再流焊接。波峰焊接已用于一部份电子产品上,但真正用于高密度多层印制板和印制大底板上还存在着不少困难,如搭接、拉尖、热损伤、铜箔脱落和印制板跷曲等现象都是需要解决的。以印制大底板为例;它的外形尺寸为320×220 mm,采用2.54网格,每格内走一条至二条微带线,板内布线点约9000个(即9000根高度为17mm的统接插针)、若采用人工焊接既费时又会出现漏焊虚焊,代之有效的是采用非接触
I. Introduction At present, high-wave welding, brazing, laser welding and infrared reflow soldering are developed instead of the original manual welding. Wave soldering has been used in a number of electronic products, but there are still many difficulties for high-density multi-layer PCBs and PCBs, such as lap, tip, thermal damage, copper foil shedding and Printed plate and other phenomena are to be solved. To print a large base plate, for example; its dimensions 320 × 220 mm, using 2.54 grid, each grid to take one to two microstrip lines, the board wiring points about 9000 (9000 root height of 17mm system Pin), if the use of artificial welding is time-consuming and there will be missed welding Weld, replaced by effective non-contact