Fluxless soldering process
AssigneeMicroelectronics Center of North Carolina
InventorsGiora Dishon, Stephen M. Bobbio
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Abstract
A method of soldering without the need for fluxing agents, high temperature, hydrogen, laser excitation or sputtering techniques. The method uses plasma excitation to remove surface oxides from solder surfaces, thereby eliminating the need for post-soldering cleaning in an accurate and efficient manner, resulting in a higher quality and long term reliability solder joint. In addition, serious environmental problems caused by cleaning solvents are avoided.
Claims43
A method of soldering without the need for fluxing agents, comprising the steps of:
- a. depositing solder on a first surface, said solder having a surface oxide layer;
- b. performing fluorine-containing plasma excitation on said solder;
- and
- c. reflowing said solder on said first surface.
A method of soldering without the need for fluxing agents, comprising the steps of:
- a. depositing a layer of solder on a first surface, said solder having a surface oxide layer;
- b. performing a fluorine-containing plasma excitation at room temperature on said solder to convert said surface oxides to a compound of solder and fluorine;
- and
- c. reflowing said solder on said first surface in a non-oxidizing ambient.
A method of soldering which removes surface oxides from exposed solder surfaces without the need for fluxing agents, comprising the steps of:
- a. depositing solder on a first surface to be soldered;
- b. performing a fluorine-containing plasma excitation on said solder until sufficient fluorine compound forms on the exposed surface of said solder to permit wetting to occur;
- and
- c. reflowing said solder on said first surface.
A fluxless soldering method for first and second surfaces comprising the steps of:
- a. providing a first surface having solder thereon, said solder having a surface oxide layer;
- and
- b. performing fluorine-containing plasma excitation on said solder;
- whereby said first surface may be soldered to a second surface without the need for post-soldering cleaning.
Dependencies are inferred from the claim text.