| abstract |
It does not contain volatile solvents and reacts with a relatively high melting point metal or metal alloy powder, a relatively low melting point metal or metal alloy, (i) a polymerizable flux and (ii) a flux at high temperature. A thermally conductive sinterable adhesive composition comprising a thermosetting adhesive flux composition comprising a deactivator that inactivates the flux. The flux preferably comprises a compound represented by the formula RCOOH, where R includes a polymerizable portion of one or more carbon-carbon double bonds. Optionally, the composition of the present invention also comprises (a) a diluent capable of polymerizing with the polymerizable carbon-carbon double bond of the flux, (b) a free radical initiator, (c) curable. A resin, and (d) a crosslinking agent and an accelerator. The composition can be applied directly to the surface of the device to be mechanically and / or electrically joined and is ideal and suitable for semiconductor die attachment. During heating, the flux promotes the wetting of the high melting powder by the molten low melting powder, thereby causing liquid phase sintering of these powders. The flux also promotes the wetting of the die and the metal coating on the substrate by the molten low melting point alloy, thereby providing improved thermal conductivity. At the same time, the flux itself crosslinks and further bonds the adhesive surface mechanically. Since it contains no volatile solvent, a void-free bond is obtained. |