| abstract |
An apparatus and method is disclosed for making additional solder joints on a printed wiring assembly which includes a printed wiring board and components soldered previously thereto. Additional components, along with additional solder to be reflowed to form new solder joints, are placed on the assembly. A titanium shield is placed over the board to cover the already completed solder joints which are not to undergo reflow, and the assembly is passed through an oven producing both infrared and convection heating. The convection heating of the oven is set to warm the entire printed wiring assembly to a temperature which remains below the reflow temperature of the solder used to attach the preexisting components. The infrared heating of the oven is applied to the board, but is prevented from heating previously completed solder joints by the shield. The infrared heating impinges on the additional solder provided to attach the additional components, and the infrared energy in combination with the convection energy causes reflow of this solder. |