Aluminum nitride, AlN, has higher thermal conductivity than alumina (Al2O3). This makes AlN substrate more attractive because heat dissipation is getting important more and more in various electronic applications, such as power electronics, high-power LED, resistors for high-frequency network , automobile applications, and so on.

There are a few methods to make conductive patterns on ceramic substrates (i.e., DBC, DPC, AMB, and thick film printing). Thick film printing has some merits. It is simple and can save production cost. Because thick film printing doesn’t require any chemical etching for patterning, it may give better reliability.

Silver paste with Bi-based glass has been used for thick film printing on alumina substrate. But this type of silver paste cannot be applied on AlN substrate due to low adhesion and blister. Contrary to alumina, AlN has no surface hydroxyl group for oxide bonding to glass and can generate gas and blisters through oxidation during sintering.

FSP-K05 is a silver paste for metalizing on AlN substrate through screen printing. Owing to its unique glass and ceramic additives, FSP-K05 gives high adhesion to AlN substrate without blisters. Also it gives good surface leveling after printing and good plating quality on itself.