Solder deposition method and solder bump forming method
AssigneeHarima Chemicals, Inc.
InventorsYouichi Kukimoto, Hitoshi Sakurai, Seishi Kumamoto, Kenshu Oyama
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Abstract
The present invention provides a solder deposition method that includes the step of forming a dam around an electrode on a substrate, the step of applying a solder precipitating composition to the substrate, and the step of depositing solder on the surface of the electrode while heating the solder precipitating composition applied. This solder deposition method is suitable for forming large bumps at fine pitches. In particular, it is capable of depositing solder in a desired height precisely and easily, and yet preventing occurrence of voids.
Claims15
A solder deposition method comprising the steps of:
- forming a dam around an electrode on a substrate;
- applying a solder precipitating composition to said substrate;
- and
- heating the resulting substrate so as to form a solder on the surface of said electrode,
- wherein said solder precipitating composition comprises a tin powder and a silver or copper complex of at least one member selected from the group consisting of aryl phosphines, alkyl phosphines and azoles.
A solder deposition method comprising the steps of:
- forming a dam around an electrode on a substrate;
- applying a solder precipitating composition comprising a tin powder and a silver or copper complex of at least one member selected from the group consisting of aryl phosphines, alkyl phosphines and azoles to said substrate;
- and
- heating the resulting substrate, whereby the tin powder reacts with the complex so as to precipitate a solder on the surface of said electrode.
A solder deposition method comprising the steps of:
- forming a dam around an electrode on a substrate;
- kneading a composition comprising tin powder and a silver or copper complex of at least one member selected from the group consisting of aryl phosphines, alkyl phosphines and azoles to form a solder precipitating composition;
- applying said solder precipitating composition to said substrate;
- and
- heating the resulting substrate so as to deposit a solder on the surface of said electrode.
Dependencies are inferred from the claim text.