Abstract:
In soldering an electronic component, for the purpose of leading molten solder during re-flow, metallic powder (8) is mixed into flux employed so as to intervene between a bump and an electrode. The metallic powder (8) has a flake or dendrite shape including a core segment (8a) of the metal molten at a higher temperature than the liquid phase temperature of solder constituting a solder bump and a surface segment (8b) of the metal with good-wettability for the molten solder and to be solid-solved in the core segment (8a) molten. In the heating by the re-flow, the metallic powder remaining in the flux without being taken in a solder portion is molten and solidified to become substantially spherical metallic particles (18) . Thus, after the re-flow, the metallic powder does not remain in a flux residue in a state where migration is likely to occur, thereby combining both solder connectivity and insurance of insulation.
Abstract:
Thermally conductive, sinterable, adhesive compositions, free of fugitive solvents, that include a powder of a relatively high melting point metal or metal alloy, a powder of a relatively low melting point metal or metal alloy powder and a thermally curable adhesive flux composition that comprises (i) a polymerizable fluxing agent; (ii) an inerting agent to react with the fluxing agent at elevated temperature, rendering it inert. The fluxing agent preferably comprises a compound with formula RCOOH, wherein R comprises a moiety having one or more polymerizable carbon-carbon double bonds. Optionally, the inventive compositions also include (a) a diluent that is capable of polymerizing with the fluxing agent's polymerizable carbon-carbon double bonds; (b) free radical initiators; (c) a curable resin; and (d) crosslinking agents and accelerators. The compositions can be applied directly onto the surfaces of devices to be joined mechanically and/or electrically and are ideally suited for semiconductor die attachment. During heating, the fluxing agent promotes wetting of the high melting point powder by the molten low melting point powder, causing liquid phase sintering of the powders. The fluxing agent also promotes wetting of the metallizations on the die and substrate by the molten low melting point alloy, providing improved thermal conductivity. Simultaneously, the fluxing agent itself crosslinks to further mechanically bond the adherent surfaces. The absence of fugitive solvents creates a void-free bond.
Abstract:
Embodiments of the present invention are directed to methods and structures providing completely filled electrical interconnections, or vias, that are disposed through a surface land mounting area, or pad, on a dielectric substrate (104). A via (100) includes a first conducting layer (106) on the inner surface (102c) of a via hole. The via hole is filled with a thermally conductive material (110) with a desired viscosity and/or thixotropic ratio. The via fill material may be a metal powder in an epoxy matrix. The dielectric substrate may be used in rigid and/or flexible circuit components such as PWBs. High levels of surface land co-planarity, or surface flatness for pads on such substrates may be achieved by the use of conductive layers formed by immersion processes. Aspects of the invention may provide reduced amounts of lead (Pb) or eliminate lead altogether from a substrate.
Abstract:
Die vorliegende Erfindung betrifft ein elektronisches Modul (25) und ein Verfahren zur Herstellung desselben. Das elektronische Modul (25) weist mehrere Bauelemente (1-6) auf einem Verdrahtungsblock (9) angeordnet auf. Der Verdrahtungsblock (9) weist mehrere Außenseiten (11-14) auf und besitzt in seinem Volumen Leitungen (15), die Kontaktanschlussflächen (10) auf den Außenseiten (11-14) untereinander verbinden. Die Kontaktanschlussflächen (10) sind mit Bauelementanschlüssen (7) der Bauelemente (1-6) elektrisch verbunden.
Abstract:
A method of using coated and/or magnetic particles to deposit structures including solder joints, bumps, vias, bond rings, and the like. The particles may be coated with a solderable material. For. solder joints, after reflow the solder material may comprise unmelted particles in a matrix, thereby increasing the strength of the joint and decreasing the pitch of an array of joints. The particle and coating may form a higher melting point alloy, permitting multiple subsequent reflow steps. The particles and/or the coating may be magnetic. External magnetic fields may be applied during deposition to precisely control the particle loading and deposition location. Elements with incompatible electropotentials may thereby be electrodeposited in a single step. Using such fields permits the fill of high aspect ratio structures such as vias without requiring complete seed metallization of the structure. Also, a catalyst consisting of a magnetic particle coated with a catalytic material, optionally including an intermediate layer.
Abstract:
A semiconductor device, wherein a solder layer for fixing chip components and a wiring member together is enclosed by a resin layer, and the solder layer is composed of a composite material formed by dispersing metal powder into a matrix metal. When a semiconductor device, comprising chip components mounted to a wiring member by a solder material, and a resin−sealed soldered portion, is secondarily mounted to an external wiring member, the flowing−out of the solder material and hence short−circuiting, wire breaking and chip component dislocation can be prevented.
Abstract:
A metal-on-ceramic substrate comprises a ceramic layer (210), a first metal layer (240), and a bonding layer (220) joining the ceramic layer to the first metal layer. The bonding layer includes thermoplastic polyimide adhesive that contains thermally conductive particles. This permits the substrate to withstand most common die attach operations, reduces residual stress in the substrate, and simplifies manufacturing processes. The thermally conductive particles are preferably chosen from the group consisting of silver, copper, gold, graphene, carbon nanotubes, hexagonal BN, wurtzitic BN, cubic BN, BN nanotubes, diamond, AIN, and Si 3 N 4. The process for creating the circuit substrate comprises: placing the bonding layer between the ceramic layer and the first metal layer; applying pressure to bond the ceramic layer to the first metal layer using the bonding layer; and curing the bonding layer.