Electrically and thermally conductive adhesive transfer tape
AssigneeMinnesota Mining and Manufacturing Company
InventorsRobert S. Reylek, Kenneth C. Thompson
Life of this patent
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Abstract
The adhesive layer of the novel transfer tape contains electrically and thermally conductive particles such as silver which are preferably spherical and are larger than the thickness of the adhesive between particles. When used to bond two rigid substrates together, pressure is applied to the substrates to flatten the particles to the thickness of the adhesive between particles, thus making good electrical and thermal connection between the substrates through each particle.
Claims24
Adhesive transfer tape comprising a flexible, low-adhesion carrier web to which is lightly adhered a layer of adhesive containing electrically and thermally conductive particles which at the bonding temperature of the adhesive are at least as deformable as are substantially pure silver spherical particles at ordinary room temperatures, said conductive particles being of uniform thickness at least five percent greater than the thickness of the adhesive between particles, and being uniformly distributed throughout the layer or preselected segments of the layer, and when said particle-containing layer is removed from the carrier web and compressed between two flat rigid plates, the particles are flattened to the thickness of the adhesive between particles, thus providing small, flat conductive areas at both surfaces of the adhesive layer.
Adhesive tape useful as a die attach adhesive comprising a flexible, low-adhesion carrier web to which is lightly adhered a layer of adhesive containing electrically and thermally conductive elements providing protuberances at each surface of the layer that are closely spaced and uniformly distributed throughout the layer, which protuberances at the bonding temperature of the adhesive are at least as deformable as are substantially pure silver spherical particles at ordinary room temperatures, the average distance between apices of the protuberances at one surface to those at the other surface being from about 10 to about 100 percent greater than the thickness of said adhesive between protuberances.
Dependencies are inferred from the claim text.