Abstract:
A composite heat sink device (1) includes a heat sink body (2, 3) formed of aluminum, the body (2, 3) having a pair of coplanar surfaces (4), and a thermally conductive solderable element (5), for example of copper, mechanically fixed to each of the coplanar surfaces (4). Each of the solderable elements has a first surface which is contiguous with one of the coplanar surfaces, and a second surface which is soldered to a printed circuit board.
Abstract:
A probe card (321) is provided for contacting an electronic component with raised contact elements. In particular, the present invention is useful for contacting a semiconductor wafer (310) with resilient contact elements (301), such as springs. A probe card (321) is designed to have terminals to mate with the contact elements on the wafer (310). In a preferred embodiment, the terminals are posts. In a preferred embodiment the terminals include a contact material suitable for repeated contacts. In one particularly preferred embodiment, a space transformer (324) is prepared with contact posts on one side and terminals on the opposing side. An interposer (325) with spring contacts (333, 334) connects a contact (335) on the opposing side of the space transformer (324) to a corresponding terminal (332) on a probe card (321), which terminal (332) is in turn connected to a terminal (331) which is connectable to a test device such as a conventional tester.
Abstract:
In a dielectric filter to be mounted on a printed circuit board, a conductive layer (x) formed on the surface of a dielectric substrate (1) includes an electroless copper-plated layer (m) formed on the surface of the substrate, and a conductive covering layer (n) having good dielectric conductivity and good solder wettability and formed on the surface of the electroless copper-plated layer (m). In place of the conductive covering layer (n) or in addition to the conductive covering layer (n), there is provided a protective synthetic resin layer (p) which covers the electroless copper-plated layer (m) or the conductive covering layer (n) and which vanishes upon exposure to heat of molten solder (25). Even when the conductive layer (x) is formed by electroless copper-plating, the conductive layer (x) is free from stain. Moreover, a terminal portion of the conductive layer (x) formed on the surface of the dielectric filter (1) can be soldered to a conductive path formed on a printed circuit board to thereby establish electric connection therebetween.
Abstract:
A solder for electronic part bonding electrodes, not containing lead and having a fine structure and excellent heat resisting fatigue characteristics is provided. A solder for electronic part bonding electrodes, the main constituent components of which are Sn, Ag and Cu, characterized in that the weight ratio of these components is 92-97 wt.% of Sn, 3.0-6.0 wt.% of Ag and 0.1-2.0 wt.% of Cu. A small amount of Ag is added to solder which contains Sn as a main component, whereby an alloy having a fine alloy structure, capable of minimizing structure variation and having excellent heat resisting fatigue characteristics can be obtained. When a small amount of Cu is added, an intermetallic compound is formed, and the bond strength of the alloy is improved.
Abstract:
In a dielectric filter to be mounted on a printed circuit board, a conductive layer (x) formed on the surface of a dielectric substrate (1) includes an electroless copper-plated layer (m) formed on the surface of the substrate, and a conductive covering layer (n) having good dielectric conductivity and good solder wettability and formed on the surface of the electroless copper-plated layer (m). In place of the conductive covering layer (n) or in addition to the conductive covering layer (n), there is provided a protective synthetic resin layer (p) which covers the electroless copper-plated layer (m) or the conductive covering layer (n) and which vanishes upon exposure to heat of molten solder (25). Even when the conductive layer (x) is formed by electroless copper-plating, the conductive layer (x) is free from stain. Moreover, a terminal portion of the conductive layer (x) formed on the surface of the dielectric filter (1) can be soldered to a conductive path formed on a printed circuit board to thereby establish electric connection therebetween.
Abstract:
A semiconductor device includes a semiconductor chip (2), a die-pad (3) on which the semiconductor chip (2) is mounted, a package (6) encapsulating the die-pad (3) and the semiconductor chip (2), and a plurality of leads (4) electrically connected to the semiconductor chip (2) and projecting from the package (6), wherein each of the leads (4) has a lead body (4-1) made of pure nickel (Ni) having a purity equal to or greater than 99% and a first film (7) formed thereon, the first film (7) being made of palladium (Pd).
Abstract:
Appareil et procédé d'interconnexion de plaquettes à circuit électronique (212, 214, 219, 221), l'interconnexion étant assurée par l'utilisation de fils de liaison torsadés (231) qui sont formés à partir de fils électriques multifilaments et qui ont des cages de transport agrandies (300) formées le long des fils de liaison. Les fils de liaison sont tirés au travers d'une pile de plaquettes de circuits pour positionner les cages en contact avec des ouvertures d'interconnexion métallisées (303) situées dans les plaquettes à circuits imprimés. L'engagement par friction des cages (300) dans les ouvertures (303) assure à la fois l'interconnexion électrique et le couplage mécanique des plaquettes à circuits imprimés (212, 214, 219, 221).
Abstract:
An improved semiconductor device( 10) is disclosed having a predetermined amount of solder (36), or other electrically conductive binder adsorbed onto the exterior package leads (18) of the semiconductor device.(10) A de-wettable coating (24) comprising preferably nickel, or alternatively chromium, is plated to a superior portion (34) of the package leads,(18) such that, when the heat is applied to the substrate mounting end (32) of the leads,(18) solder (36) desorbes from the de-wettable layer (24) and flows down the lead (18) to the contact pads (40) on the mounting substrate (42) and forms a solder joint.(46) The amount of solder delivered to the contact pad for joint formation is determined by the thickness of the adsorbed solder layer (36) overlying each package lead.(18) Only enough solder is provided on each lead (18) sufficient to form the joint (46) thus avoiding solder bridging between adjacent contact pads.(40)
Abstract:
A circuit board may be moulded from an aromatic thermoplastic material, the circuit board (1) comprising one or more die attachment sites (8) moulded therein preferably with the die attachment site recessed so that the surface of the die (9) is co-planar with conductive tracks on the board. The die attachment sites may be moulded with a relief pattern (30) therein so that thermally induced strains of an attached die are reduced. Also for the same reason a heat sink may be attached underneath the carrier below the carrier's die attachment site and thermally conductive material may connect them together. The heat sink may be used for mechanical anchorage.
Abstract:
A method and a solder transfer member (18) for applying discrete bodies of solder of predetermined size to the leads of a component for subsequent surface mounting to a substrate. The transfer member is a plate having a non-wetted surface (20), for example titanium, with an array of cavities (22) matching the component lead pattern, each having a volume corresponding to the desired amount of solder to be applied to the corresponding lead. The method includes placing solder paste on the transfer member and filling the cavities by wiping the plate surface. The component is placed on the transfer member with the leads contacting the solder paste in the cavities. Reflow of the solder paste bonds to each lead a discrete body of solder having a precisely determined size. To limit wicking of solder on the leads, selective masking may be performed by applying a water soluble mask coating to the leads and removing the mask from selected areas by placing the component against a surface charged with water before placing the component on the transfer member.