Solder preform and a process for its manufacture
AssigneesSenju Metal Industry Co., Ltd., Denso Corporation
InventorsNaohiko Hirano, Akira Tanahashi, Yoshitsugu Sakamoto, Kaichi Tsuruta, Takashi Ishii, Satoshi Soga
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Abstract
A mixed mother alloy is prepared from a solder mixture comprising a pyrolyzable flux and high melting point metal particles, the mixed mother alloy is charged into a large amount of molten solder and stirred, and a billet is prepared. The billet can then be extruded, rolled, and punched to form a pellet or a washer, for example.
Claims19
A process for manufacturing a solder preform comprising the steps of:
- (1) mixing high melting point metal particles with a pyrolyzable liquid flux to obtain a mixture;
- (2) charging the mixture into molten solder at a temperature lower than the melting point of the high melting point metal particles followed by stirring to prepare a mixed mother alloy in which the high melting point particles are dispersed;
- (3) charging the mixed mother alloy into molten solder at a temperature lower than the melting point of the high melting point metal particles followed by stirring and casting into a mold to prepare a billet;
- (4) forming the billet into a member suitable for punching;
- and
- (5) punching the member to form a solder preform containing the high melting point metal particles dispersed in a solder alloy matrix phase.
A process for manufacturing a solder preform comprising the steps of:
- (1) mixing high melting point metal particles with a pyrolyzable liquid flux to obtain a mixture;
- (2) charging the mixture into molten solder at a temperature lower than the melting point of the high melting point metal particles followed by stirring and rapid cooling of the molten solder to obtain a mixed mother alloy in which the high melting point metal particles are dispersed;
- (3) preparing a billet by charging the mixed mother alloy into molten solder at a temperature lower than the melting point of the high melting point metal particles followed by stirring, casting into a mold, and rapid cooling of the molten solder;
- (4) extruding the billet with an extruder to form a strip;
- (5) rolling the strip in a rolling mill to form a ribbon which is thinner than the strip;
- and
- (6) punching the ribbon to a predetermined shape to form a solder preform containing the high melting point metal particles.
A process for manufacturing a solder member comprising:
- mixing high melting point metal particles having a′particle diameter of at least 20 μm with a pyrolyzable liquid flux to obtain a mixture;
- charging the mixture into molten solder comprising a solder alloy having a lower melting temperature than the high melting point metal particles and stirring to prepare a mixed mother alloy in which unmelted high melting point metal particles are dispersed;
- charging the mixed mother alloy into molten solder, stirring, casting, and solidifying to obtain a cast member comprising a solder alloy matrix phase and high melting point metal particles having a higher melting point than the matrix phase and having a particle diameter of at least 20 μm dispersed in the matrix phase;
- and
- shaping the cast member.
Dependencies are inferred from the claim text.