Silica Coated Filler Material
Dow has developed SCAN 71, a thermally conductive, silica coated aluminum nitride filler material for semiconductor transfer molding compounds that exceeds the limitations of silica-based filler materials.
The filler has a maximum particle size of 75 microns and consists of aluminum nitride (AlN) coated with silica, a formulation that provides hydrolytic stability and allows the particles to be processed in a manner similar to fused silica. These materials provide an alternative to other filler materials, such as fused or crystalline silica. The silica coated aluminum nitride fillers are suitable for a range of plastic packaging applications.
Silica coated aluminum nitride enables the molding compound to conduct more heat away from the chip, reducing junction-to-air (theta ja) and junction-to-case (theta jc) temperatures.
See table below for a comparison of heat dissipation characteristics of various epoxy molding compounds.
The Dow Chemical Company, Customer Information Group E#406, P.O. Box 1206, Midland, MI 48641-1206. Tel: 800-447-4369.
|
|
|
|
|
Thermal conductivity |
Low |
Incremental increase in thermal conductivity |
5-7 times more thermally conductive |
|
Coefficient of thermal expansion (CTE) |
Current standard |
Relatively high; increased risk of device failure |
Similar to fused silica |
|
Heat distribution |
Thermal gradients result in stress, increasing potential for delamination |
Thermal gradient slightly reduced |
Significant improvement in thermal gradients/distribution |
Comparison of Heat Dissipation Characteristics of Various Epoxy Molding Compounds