Dry soldering with hot filament produced atomic hydrogen

Claim 3

The system of claim 1, wherein said elevated temperature is within the range of from 500 degrees C. and 2200 degrees C.

Claim 4

The system of claim 1, further comprising means for maintaining said hydrogen-containing gas at about 10 Torr absolute pressure within said deoxidation chamber.

Claim 5

The system of claim 1, wherein said filament is composed of a metal selected from the group comprising tungsten and rhenium.

Claim 6

The system of claim 1, wherein said filament is in the form of a grid.

Claim 7

The system of claim 1, wherein the vertical distance between said filament and said support is about 1.5 inches.

Claim 10

The system of claim 6, wherein the vertical distance between said filament and said support is about 1.5 inches.

Claim 11

The system of claim 6 wherein said filament is in the form of a grid.

Claim 14

The method of claim 10, wherein said filament is maintained at a temperature in the range of 500 degrees C. and 2200 degrees C. by supplying electrical power to said filament.

Claim 15

The method of claim 10, further comprising maintaining an electrically positive-biased collection grid in the vicinity of said filament so as to trap thermionic electrons emitted at elevated filament temperatures.

Claim 16

The method of claim 10, further comprising maintaining an electrically negative-biased repulsion grid in the vicinity of said piece part so as to repel thermionic electrons emitted at elevated filament temperatures.

Claim 17

The method of claim 10, wherein said filament is maintained at a vertical distance of about 1.5 inches of said metal oxide surface.

Claim 18

In a continuous soldering and solder reflow system having an inlet vacuum lock chamber with an inlet lock, and outlet vacuum lock chamber with an outlet lock and housing a solder preform and lead attachment stage and a cooling stage, a conveyor for moving piece-parts through the sequence of said inlet lock, said inlet vacuum lock chamber, said solder preform and lead attachment stage, said cooling stage and said outlet lock, said solder preform and lead attachment stage including heating means for melting solder, and a vacuum manifold connected to said inlet vacuum lock chamber and said outlet vacuum lock chamber, the improvement comprising: (a) a deoxidation chamber located between said inlet vacuum lock chamber and said solder preform and lead attachment stage of said outlet vacuum lock chamber and connected to said vacuum manifold; (b) means for maintaining a vacuum in said deoxidation chamber; (c) means for introducing a hydrogen-containing gas into said deoxidation chamber, said gas containing no more than about 4% by volume hydrogen in inert gas; (d) a filament located in said deoxidation chamber in the vicinity of said conveyor and a metal oxide surface of said piece-parts as they travel on said conveyor; and (e) means for maintaining said filament at such an elevated temperature as to induce a substantial portion of the hydrogen in said hydrogen-containing gas to form atomic hydrogen so as to form reactive species.

Claim 19

In a continuous soldering and solder reflow system having an inlet vacuum lock chamber with an inlet lock, and outlet vacuum lock chamber with an outlet lock and housing a solder preform and lead attachment stage and a cooling stage, a conveyor for moving piece-parts through the sequence of said inlet lock, said inlet vacuum lock chamber, said solder preform and lead attachment stage, said cooling stage and said outlet lock, said solder preform and lead attachment stage including heating means for melting solder, and a vacuum manifold connected to said inlet vacuum lock chamber and said outlet vacuum lock chamber, the improvement comprising: (a) a deoxidation chamber located between said inlet vacuum lock chamber and said solder preform and lead attachment stage of said outlet vacuum lock chamber and connected to said vacuum manifold; (b) means for maintaining a vacuum in said deoxidation chamber; (c) means for introducing a hydrogen-containing gas into said deoxidation chamber, said gas containing no more than about 4% by volume hydrogen in inert gas; (d) a filament located in said deoxidation chamber in the vicinity of said conveyor and a metal oxide surface of said piece-parts as they travel on said conveyor; and (e) means for maintaining said filament at such an elevated temperature as to induce a substantial portion of the hydrogen in said hydrogen-containing gas to form atomic hydrogen so as to form reactive species.

Claim 20

The system of claim 15, wherein said elevated temperature is maintained within the range of from 500 degrees C. and 2200 degrees C.

Claim 21

The system of claim 16, further comprising means for maintaining said hydrogen-containing gas at about 10 Torr absolute pressure in said deoxidation chamber.

Claim 22

The system of claim 17, wherein said filament is composed of a metal selected from the group comprising tungsten and rhenium.

Claim 23

The system of claim 18, wherein said filament is in the form of a grid.

Claim 24

The system of claim 19, further comprising an electrically positive-biased collection grid located in the vicinity of said filament so as to trap thermionic electrons emitted at elevated filament temperatures.

Claim 25

The system of claim 20, further comprising an electrically negative-biased grid located in the vicinity of said metal oxide surface so as to repel thermionic electrons emitted at elevated filament temperatures.

Claim 26

The system of claim 21, further comprising means for introducing a hydrogen-containing gas into said outlet vacuum lock chamber at said solder preform and lead attachment stage for maintaining a pressure in said stage above that in said deoxidation chamber.

Claim 27

The system of claim 15, wherein the vertical distance between said filament and said conveyor is about 1.5 inches.