Method and apparatus of manufacturing an electronic circuit board
AssigneeHitachi, Ltd.
InventorsTasao Soga, Toshiharu Ishida, Tetsuya Nakatsuka, Hanae Shimokawa, Koji Serizawa, Yasuo Amano, Suguru Sakaguchi, Hiroshi Yamaguchi
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Abstract
Electronic components are bonded to an electronic circuit board with a lead-free solder. The bonded structure is cooled from a temperature close to the liquids temperature of the solder to a temperature close to the solids temperature of the solder at a first cooling rate of about 10 to 20° C./second, followed by cooling the bonded structure to a temperature lower than the solids temperature of the solder at a second cooling rate of about 0.1 to less than 5° C./second.
Claims21
A method of manufacturing an electric circuit board, the method comprising the steps of;
- bonding electronic components to the circuit board with a lead-free solder;
- cooling the bonded structure from a temperature close to the liquidus temperature to a temperature close to the solidus temperature of the lead-free solder at a first cooling rate of from about 10 to 20° C./second;
- and cooling the bonded structure from the temperature close to the solidus temperature of the lead-free solder at a second cooling rate lower than the first cooling rate.
A method of manufacturing an electric circuit board, the method comprising the steps of:
- bonding electronic components to the circuit board with a lead-free solder;
- and
- cooling the bonded structure from the temperature close to the solidus temperature of the lead-free solder at a cooling rate of from 0.1 to less than 5° C./second.
Dependencies are inferred from the claim text.