Abstract:
A compliant element (23, 25) is provided between an integrated circuit (11) and a substrate (19) which are bonded and interconnected by an anisotropic conductive adhesive (20) comprising conductive particles (21) in a polymer matrix (22). In one embodiment, one set of bonding pads (12, FIG. 2) is coated with a layer (23) of a metal that is significantly softer than the metal from which the conductive particles are made, which permits an oversized conductive particle (21a) to indent into the soft metal layer (23). In another embodiment, one of the sets of bonding pads (15, FIG. 3) is arranged on a relatively thick layer of adhesive (25) which is sufficiently viscous at the temperature at which contact is made to permit the bonding pad (15) to pivot in response to pressure from an oversized conductive particle (21d).
Abstract:
An electrically conductive adhesive composition which provides electric conductivity between facing electrodes but maintains electric insulation in the lateral direction across the facing direction, said composition comprising (a) a nonconductive base resin and (b) electrically conductive particles incorporated and dispersed in the resin (a); wherein(I) said electrically conductive particles (b) are composed of(b-1) 10 to 75%, based on the total weight of the components (a), (b-1) and (b-2), of abrasive grain-like electrically conductive particles having an average particle diameter of at least 1 micrometer, and(b-2) 0.2 to 20% by weight, based on the total weight of the components (a), (b-1) and (b-2), of electrically conductive fine particles having an average particle diameter of not more than 0.5 micrometer, and(II) said electrically conductive adhesive composition contains a solvent for said base resin (a) in an amount required to form said composition into the state of a printing ink or a paint.
Abstract:
A test assembly for testing a high density circuit or a test board, which comprises a test head containing a mirror image circuit of the circuit to be tested on the test board, a plurality of test points on the test head circuit, the test points comprising a plurality of metal pads, and metal contacts soldered to the metal pads, the metal contacts being in the form of metal balls or flakes selected from the group consisting of brass, bronze or copper, of a size ranging from about 5 to about 30 mils. The test head is positiioned over the test board with the metal contacts on the test head in contact with corresponding test points on the high density circuit on the test board. Means are provided for connecting the circuit on the test head with a tester, thereby providing signals from the high density circuit under test through the test head circuit to the tester. A solder composition is provided which is especially adapted for soldering the metal contacts to the metal pads on the test head. Such solder composition comprises a liquid vehicle, finely divided solder metal dispersed in the vehicle, the solder metal having a particle size ranging from 40 to 70 microns, and additional metal particles dispersed in the vehicle, the additional particles being in the form of metal balls or flakes selected from the group consisting of brass, bronze and copper, the additional metal particles having a size ranging from about 5 to about 30 mils and being present in an amount ranging from about 5 to about 60% by weight of the total composition.
Abstract:
Novel solder composition or solder cream, particularly adapted for soldering components in electronic circuitry, comprising finely divided solder metals such as tin and lead, dispersed in a vehicle containing viscosity controlling agents, organic solvents, and a rosin or rosin derivative as a flux. By employing a narrow range of rosin-containing vehicle, that is between 13 and 14%, and between 86 and 87% of solder metal, by weight of the solder composition, and fine particle size solder metal of from 40 to 70 microns, the formation of solder balls is essentially eliminated, thus avoiding the necessity of removing such solder balls.
Abstract:
An electrically conductive adhesive comprises electrically conductive particles mixed in a non-conductive base at such a mixing ratio that the conductive particles are not in contact with one another. When this adhesive is disposed between facing electrodes, it provides electric conductivity between the facing electrodes but maintains electric insulation in the lateral direction.
Abstract:
According to embodiments of the present invention, an ink composition for forming a conductive film is provided. The ink composition includes a plurality of nanostructures distributed in at least two cross-sectional dimension ranges, wherein each nanostructure of the plurality of nanostructures is free of a cross-sectional dimension of more than 200 nm; preferably each nanostructure of the plurality of nanostructures is encapsulated with a surfactant. In a preferred embodiment, the nanoparticles have bimodal distributions: small particles (5 - 10 nm) and large particles (30 - 100 nm), wherein the small particles are likely to occupy the empty space between the large particles, and therefore helps in densification of the film. According to further embodiments of the present invention, a conductive member is formed by fusing the plurality of nanostructures of the ink composition to each other.