Solderable conductor composition and a method of soldering a lead to a lead pad

Claim 1

A conductor composition comprising: finely divided gold particles and finely divided inorganic binder particles dispersed in an inert liquid vehicle having by weight 98.2 to 98.7 gold particles and, complementally, 1.8 to 1.3% inorganic binder particles, the binder consisting essentially of by total weight of gold and binder, 0.35 to 0.24 percent PbF 2 , 0.34 to 0.23 percent CdO, 0.68 to 0.39 percent Cu 2 O, and the balance glass.

Claim 3

The method of soldering a lead to a lead pad on a substrate comprising the steps of: printing a conductor pattern including at least one lead pad on the substrate using a gold composition, said gold composition being composed of finely divided gold particles and finely divided inorganic binder particles dispersed in an inert liquid vehicle, by weight 98.2 to 98.7% gold particles and complementally 1.8 to 1.3% inorganic binder particles, the binder consisting essentially by total weight of gold and binder of: 0.68 to 0.39 percent Cu 2 O 0.35 to 0.24 percent PbF 2 l 0.34 to 0.23 percent CdO and the balance glass: allowing the print to level at room temperature: heating the substrate to a temperature substantially not exceeding 130° C. until substantially dry; firing the substrate to sinter the inorganic materials; vapor degreasing the fired substrate; applying a solder flux to the lead pad; placing a solder preform on the lead pad; heating the substrate to allow the solder on the lead pad to liquify: cooling the substrate to solidify the solder; presoldering a lead; cleaning flux off of the lead; applying solder flux to the solder on the lead pad; heating the substrate to a temperature at which the solder begins to reflow: placing the presoldered wire on the lead pad; maintaining the solder in a liquid state for a predetermined period of time: cooling the substrate to ambient temperature, and cleaning the substrate and the lead soldered to the lead pad.

Claim 4

The method of soldering a lead to a lead pad on a substrate comprising the steps of: printing a conductor pattern including at least one lead pad on the substrate using a gold composition, said gold composition being composed of finely divided gold particles and finely divided inorganic binder particles dispersed in an inert liquid vehicle, by weight 98.2 to 98.7% gold particles and complementally 1.8 to 1.3% inorganic binder particles, the binder consisting essentially by total weight of gold and binder of: 0.68 to 0.39 percent Cu 2 O 0.35 to 0.24 percent PbF 2 l 0.34 to 0.23 percent CdO and the balance glass: allowing the print to level at room temperature: heating the substrate to a temperature substantially not exceeding 130° C. until substantially dry; firing the substrate to sinter the inorganic materials; vapor degreasing the fired substrate; applying a solder flux to the lead pad; placing a solder preform on the lead pad; heating the substrate to allow the solder on the lead pad to liquify: cooling the substrate to solidify the solder; presoldering a lead; cleaning flux off of the lead; applying solder flux to the solder on the lead pad; heating the substrate to a temperature at which the solder begins to reflow: placing the presoldered wire on the lead pad; maintaining the solder in a liquid state for a predetermined period of time: cooling the substrate to ambient temperature, and cleaning the substrate and the lead soldered to the lead pad.

Claim 5

The method of soldering a copper lead to a lead pad on an alumina substrate having a thin dielectric layer of alumina fixed with glass on one surface of the substrate comprising the steps of: printing a conductor pattern including a lead pad on the dielectric layer of the substrate using a gold composition, said gold composition being composed of finely divided gold particles and finely divided inorganic binder particles dispersed in an inert liquid vehicle, by weight 98.5% gold particles and complementally 1.5% inorganic binder particles, the binder consisting essentially by total weight of gold and binder of: 0.56 percent Cu 2 O 0.24 percent PbF 2 0.23 percent CdO, and the balance glass; allowing the print to level at room temperature, drying the print for twenty minutes in air at a temperature of from 110° to 130° C.; firing the substrate at a temperature of 125°±5° for seven minutes minimum, the rise and fall rate being from 60° to 100° C. per minute, the total cycle time being of the order of 40-45 minutes in air; vapor degreasing the fired substrate with trichloroethane; drying the substrate with nitrogen gas; placing the substrate in a preheat stage and raising the temperature to 135° C.±5° for three minutes; applying a non-activated liquid rosin solder flux to the lead pad at a temperature of about 240° C.±5° C.; placing a solder preform 50% indium, 50% lead on the lead pad; allowing the solder to flow for two seconds; cooling the substrate for approximately two minutes; presoldering a copper lead with 50% indium, 50% lead; dipping the presoldered lead into pure trichloroethylene at plus 80°±5° to clean off the flux; applying a non-activated liquid rosin solder flux to the solder on the lead pad; heating the substrate to a temperature at which the solder on the lead pad begins to reflow; placing the presoldered wire in the liquid solder on the lead pad; continuing to heat the substrate to maintain the solder in a liquid state for approximately two minutes; and cooling the substrate, the lead pad and the lead; and cleaning the substrate and lead soldered to the lead pad with trichloroethylene at plus 80°±5° C.

Claim 6

The method of soldering a copper lead to a lead pad on an alumina substrate having a thin dielectric layer of alumina fixed with glass on one surface of the substrate comprising the steps of: printing a conductor pattern including a lead pad on the dielectric layer of the substrate using a gold composition, said gold composition being composed of finely divided gold particles and finely divided inorganic binder particles dispersed in an inert liquid vehicle, by weight 98.5% gold particles and complementally 1.5% inorganic binder particles, the binder consisting essentially by total weight of gold and binder of: 0.56 percent Cu 2 O 0.24 percent PbF 2 0.23 percent CdO, and the balance glass; allowing the print to level at room temperature, drying the print for twenty minutes in air at a temperature of from 110° to 130° C.; firing the substrate at a temperature of 125°±5° for seven minutes minimum, the rise and fall rate being from 60° to 100° C. per minute, the total cycle time being of the order of 40-45 minutes in air; vapor degreasing the fired substrate with trichloroethane; drying the substrate with nitrogen gas; placing the substrate in a preheat stage and raising the temperature to 135° C.±5° for three minutes; applying a non-activated liquid rosin solder flux to the lead pad at a temperature of about 240° C.±5° C.; placing a solder preform 50% indium, 50% lead on the lead pad; allowing the solder to flow for two seconds; cooling the substrate for approximately two minutes; presoldering a copper lead with 50% indium, 50% lead; dipping the presoldered lead into pure trichloroethylene at plus 80°±5° to clean off the flux; applying a non-activated liquid rosin solder flux to the solder on the lead pad; heating the substrate to a temperature at which the solder on the lead pad begins to reflow; placing the presoldered wire in the liquid solder on the lead pad; continuing to heat the substrate to maintain the solder in a liquid state for approximately two minutes; and cooling the substrate, the lead pad and the lead; and cleaning the substrate and lead soldered to the lead pad with trichloroethylene at plus 80°±5° C.