Diotec Develops Direct Bonding Production Process

November 05, 2002 by Jeff Shepard

Diotec Semiconductor GmbH (Heitersheim, Germany) announced development of a new production process that allows direct bonding of semiconductors to heatsinks by means of a "cold spraying" industrial process. Silicon chips can be soldered directly onto heatsinks made from aluminum. The new packaging technology can be used wherever the heatsink is also conducting current, including at output rectifiers of car alternators or at diode assemblies for welding equipment.

Copper particles are sprayed at supersonic speed onto the aluminium heatsink forming a thin, adhesive coating. For the adhesion only, kinetic energy is responsible; there is no melting of the material and no unwanted oxidation. On the formed copper layer, silicon chips can be direct soldered, and upper-side contacting is made by lead wires. Finally, the assembly is molded for mechanical protection.