Join Mechanism of Press-Soldered Joints in Copper to Copper
Takashi Haramaki, Mitsuo Nakamura
pp. 337-342
DOI:
10.2207/qjjws.10.337Abstract
Copper to copper lap joint was made by the resistance heating, applying pressure simultaneously. The copper plate was pre-soldered and the alloyed layer was pre-formed by using Pb-50Sn solder and then joint mechanism of press-soldered joints was analyzed.
The reason of enhancing strength and heat resistance heated by applying voltage in press-soldered joints is summarized as follows.
(1) Solder composition turns to Cu-Sn alloy composition.
(2) Joint layer with higher melting point was formed in which Cu increases and Sn decreases.
(3) In terms of the crystal structure, Cu3Sn, Cu6Sn5 and Cu(α) phases turns to Cu41Tn11 and Cu(α) phases which have high heat resistance.