| abstract |
An improved method and apparatus for making solder connections from input/output connecting pins to the circuitry on a pinned metallized ceramic substrate. A solder preform in the shape of a sphere provides the correct volume of solder. These spheres are held in position at each desired joint by a templet. The substrate, solder sphere and templet assembly is passed through a furnace in a reducing atmosphere and at a temperature to facilitate solder reflow and wetting, thus creating a sound mechanical and electrical connection between the pin and its portion of the circuitry. The method and apparatus of the invention provides joints have a high degree of reliability such that all connections are made to acceptable soldering standards, none lacking integrity. Only harmless by-products are produced in the practice of the invention, and no residue is produced which requires cleaning by means of chemical solvents and therefore is environmentally superior. |