原帖由5楼楼主 mono 于2007-10-30 14:27发表 我的观点是--对与强制对流炉,这中上下不同的设置与上下温度设置一致并无多大的区别.
至于第二面的元件掉不掉,看下面的公式好了
SMT weight limits for side 2: for double sided SMT board, ensure that components on the bottom side will not fall off during the second reflow cycle by using following formula:
allowable weight (g) <= [ surface area of one lead(ball) square mm] * [ number of leads(balls)] *
0.665