Occurrence of Non-Wetted Parts in Dip Soldering (Report-1)(Welding Physics, Processes & Instruments)

In dip soldering of electronics parts, the non-wetted parts produced on lead wires are depended on the immersion depth of them. In order to prevent the non-wetted parts, it was confirmed from this experiment that the immersion depth of 0.8mm dia. lead wire must be limitted within about 1.6mm. On the other hand, the depth recommended by JIS C5033 "Solderability Testing Method for Electronic Components" is 2 to 2.5mm. This value was justified by appling a theoretical consideration and II type wetting process named in this paper.