Elastomer bonding is a proprietary bonding method that was initially developed for bonding materials that were impossible to effectively bond with metals. Interest in this bonding technique has grown considerably in the last few years and now accounts for a high percentage of our business. As indium prices have increased, Elastomer bonding has become a cost effective alternative, especially where both the target and backing plate are consumable and indium reclaim is unrealistic.
The major advantages of Elastomer bonding are its low cure temperature (reducing internal bond stresses from thermal miss match) and high operation temperature (250 °C). Elastomer bonding has permitted new materials to be bonded effectively by increasing line yield from stress fractures. Targets have also been scaled to larger dimensions based on the Elastomer bonding technology. Multiple piece targets in excess of 120" x 110" and single piece targets of 110" x 100" have been bonded while maintaining flatness tolerances.
The Elastomer bonding has less than 1% total mass change at 250 °C for 24hrs at 1x10-7 Torr. The thermal conductivity of the bond is 54W/mK at 0 °C compared to Indium at 83.7W/mK, however the Elastomer bond will operate at 250 °C versus indium which melts at 156 °C.