The identified route to realising the objective was to manufacture semiconductor packages from the Transient Liquid Phase (TLP) bonding of high volume silicon carbide particulate loaded aluminium alloy Metal Matrix Composite (MMC). The deposition of the alumina substrate and copper tracks, prior to integration of the semiconductor components, was to be developed based upon the use of High Velocity Oxyfuel (HVOF) spraying.
At the closure point of the project the preferred MMC material had been procured and had undergone preliminary evaluation. This included initial TLP bonding trials using silver and copper at the interface. HVOF spraying had been successfully demonstrated for the deposition of copper tracks in a defined pattern onto the insulating alumina substrate and the HVOF spray deposition of alumina onto MMC coupons.
However, an assessment of the costs associated with the TLP bonding route for the fabrication of the semiconductor packages indicated that the process would not be economically viable. In addition, technical delays were encountered during the initial period in the development of the HVOF powders and the TLP bonding of the MMC to form demonstrator packages. At the mid-term point it was felt that, due to the above reasons, the objectives of the project could not be attained within the time and budget constraints of the CRAFT scheme. Hence the decision was taken to close the project at the mid-term.
Funding SchemeCRS - Cooperative research contracts
SN2 2QW Swindon
LE13 0PB Melton Mowbray
BN26 6JF Polegate
CB11 3AQ Saffron Walden
CB1 6AL Cambridge