Metallized Ceramic Substrate Pin Tinning and Solder Ball Reflow in a Controlled Atmosphere by Using a Tracked Separation Band
Original Publication Date: 1985-Mar-01
Included in the Prior Art Database: 2005-Feb-18
User requirements demand that metallized ceramic (MC) substrate pins be tinned. Attempts to tin the pins after the Substrate Tin Enhancement Process, using existing wave solder machines, have not been successful due to flux degradation and copper oxidation of the top surface in air. In addition, the attempts made to introduce an inert atmosphere into the existing wave solder machines have failed due to difficulty in containing the controlled atmosphere. This difficulty is created by the substrate pushing fingers which, by design, pass through the space above the substrate. A tracked separation band is designed to eliminate top surface flux degradation and copper oxidation while pinning, and permit solder ball reflow while pin tinning. A band of thin, non-solder wettable, compliant metal 11 (Fig.