Abstract:
Method for making a multilayer electrical interconnect with stacked pillars between layers using a minimal number of conventional process steps. The method includes sputtering a chromium/copper/titanium trilayer on a dielectric base, depositing a patterned mask on the trilayer, etching the exposed trilayer, removing the mask, depositing a layer of polyimide over the unetched copper, forming a via in the polyimide above the copper, electrolessly plating nickel into the via, and polishing the interconnect to form a planar top surface.
Abstract:
A method for forming connections between copper conductors disposed on a substrate includes the steps of coating the copper conductors with a layer of nickel, exposing the coated copper conductors to a gas which includes a tungsten-bearing compound, and irradiating the substrate with a laser beam to deposit the tungsten between the copper conductors. A system for forming connections between copper conductors disposed on a substrate, includes means for coating the copper conductors with a layer of nickel, means for exposing the coated copper conductors to a gas which includes a tungsten-bearing compound, and means for irradiating the substrate with a laser beam to deposit the tungsten between the copper conductors.
Abstract:
Slide forming tape-automated-bonded leads extending from an integrated circuit chip with a support ring on the leads between the outer periphery of the chip and the outer lead ends. After the leads are formed the support ring remains attached to the vertical portion of the leads opposite the chip. The present invention is well suited for minimizing and footprint on relatively long TAB leads which fan out and require a support ring to maintain proper lead pitch.
Abstract:
A thermally and electrically conductive paste and its method of use for making a detachable and compliant thermal conductive connection between two surfaces or making an electrical connection between first and second electrical components. The paste is comprised of a liquid metal and particulate solid constituents which is non-solidifying, conformable, compliant, is removable, provides containment to impulsive loading, and is simple to apply.
Abstract:
A method is disclosed for laser bonding two highly reflective electrical members. The first electrical member is coated with a material that is well absorbent of laser energy at the laser beam wavelength, has a lower melting point than either the first or second electrical members, and has a low solubility in a solid alloy of the electrical members. The laser characteristics are selected so that as bonding occurs an alloy of the electrical members solidifies and a solidification front drives the molten coating and molten compounds containing the coating away from the bond interface towards the exterior periphery of the bond, and substantially all of the solidified bond interface consists of an alloy of the first and second members. The coating can also aid in wetting the bond interface. In one example a copper electrical member coated with tin is bonded to a gold electrical member using a pulsed YAG laser with a beam diameter of 0.002 inches, a wavelength of 1.064 microns, an energy output of 1/4 to 1/2 joule, and a pulse time of 1 millisecond. Substantially all of the resulting bond interface consists of a copper/gold alloy without any tin intermetallics.
Abstract:
A fluid heat exchanger for cooling an electronic component having a housing for receiving heat from the electronic component in which the housing has a fluid inlet and an outlet at opposite ends of the housing. The cross-sectional area of the housing for conveying fluid from the inlet to the outlet decreases from the inlet to the outlet thereby reducing pressure drop without sacrificing thermal performance. The cross-sectional area may be decreased by tilting a top of the housing relative to a bottom, or providing a plurality of fins separated by channels in which the cross-sectional area of the channels decreases from the inlet to the outlet.
Abstract:
Bonding a plurality of TAB tape leads to electrical pads in and aligned with the surface of a die by covering the pads with a plurality of electrically conductive particles, aligning the electrical leads with the particles and the pads, and simultaneously bonding the particles to the pads and the electrical leads to the particles. Preferably the particles are solid spheres and may be applied in various ways such as covering the entire surface with the spheres, covering the pads with an adhesive material prior to the spheres, or covering the pads with a mixture of adhesive and spheres. The method is particularly well suited for flip chip bonding.
Abstract:
A thermally conductive coiled spring laid on its side provides a compliant, high conductive, low force thermal path between a heat source and a heat sink. Each spring contact provides two parallel heat conduction paths via each coil in the spring. The spring can be canted to permit slidable contact with a surface. In one embodiment a plurality of copper springs arranged in parallel can provide a thermal path between an electronic component and a heat sink in close proximity. The springs may be permanently attached to at least one surface at the points of contact.
Abstract:
A method is described for patterning electroless plated metal on a polymer substrate. A substrate is first coated with a polymer suitable for complexing noble metal compounds. The substrate is then complexed with a noble metal compound, such as containing palladium, selectively irradiated to form the desired conductor pattern, and then etched so that the desired pattern remains. The substrate is subsequently placed in an electroless plating bath to form a metal pattern. Alternatively, before applying the noble metal compound, a substrate immersed in a polymer solution suitable for complexing a noble metal compound can be selectively irradiated to selectively deposit polymer on the substrate, followed by applying a noble metal compound and an electroless plating bath.
Abstract:
A method and apparatus for aligning two mating tools is provided by a plurality of alignment members extending upward from the surface of one mating tool so that the alignment members engage in slidable contact with alignment tracks formed in the edges of the second mating tool. The alignment members and tracks can be formed in the four corners of rectangular mating tools, and the alignment members can be cylindrical rods with dome shaped tops. The alignment is useful both for tooling set-up as well as tooling usage. The alignment means can be used on a punch and lead form anvil for forming the outer leads of an integrated circuit bonded to a TAB tape.