Traditional high thermal die attach pastes (DAP) are typically silver- filled resin matrices which can offer high adhesion, good conductivity and high reliability. Though providing desirable adhesion and reliability in various bonding setting, they usually cannot offer ultra-high thermal conductivity since the silver particles do not form good enough contact at the interface. On the other hand, pure silver sintering materials can easily reach thermal conductivity (TC) > 100 w/mk but usually require high pressure and temperature curing to enable silver particle sintering. These silver sintering materials have further limitations of reliability due to their porous or brittle nature and cannot be extended to larger die sizes due to high stress in bond line.
Keeping these limitations in mind, Henkel developed a new class of material combining high TC performance of pure silver sintering materials and high reliability performance of resin based DAP. This technology is identified as semi-sintering paste.