Abstract:
A method of creating high density interlayer interconnects on circuit carrying substrates. A circuit pattern (20) is formed on one side of a substrate (10), and gold balls (30) are selectively placed on the circuit pattern using a thermosonic ball bonder. A liquid solution of a polymer is cast directly on the substrate and the etched circuit pattern such that only the upper portion of each gold ball is revealed when the liquid polymer solution is then dried and cured to form a dry film (40). A second layer of metal is then deposited directly on the dry film, such that it is electrically and mechanically connected to the exposed top of the gold balls. A second circuit pattern (50) is then formed in the second layer of metal. The resulting high density interconnect has two circuit layers separated by a dielectric layer. Each circuit layer is connected to the other by the gold balls that serve as conductive vias.
Abstract:
A flexible circuit board, an end of which is uniformly connected to the inside of a springy metal layer, which has been bent to a U shape, and the rest of which extends in a predetermined width away from the springy metal layer. The flexible circuit board is equipped with bump-shaped connecting terminals on the opposed bent sections, each connecting terminal having a first side connected to the ends of the circuit wiring pattern formed on the flexible circuit board and a second generally opposed side projecting outwardly from the flexible circuit board. The bump-shaped terminals are electrically connected to the terminal of the magnetic head suspension, which is made integral with circuit wiring, by the clamping force of the springy metal layer.
Abstract:
Bumps to be connected to inspection electrodes of semiconductor chips are formed on a surface of a flexible substrate. A plating layer is formed which is made of a harder material than the bumps formed on the flexible substrate and which has a concave portion or a convex portion whose diameter is equal to or smaller than half the diameter of the bumps, on a flat metallic plate. The plating layer of the metallic plate is pressed against top surfaces of the bumps, so that irregularities are formed in the top surfaces of the bumps.
Abstract:
Circuit boards are manufactured by forming a substrate with a dielectric surface, laminating a metal foil and a peelable film to the substrate, and forming holes in the substrate through the peelable film and foil. A filler material with an organic base may be filled with electroconductive particles or dielectric thermoconductive particles. The filler material is laminated onto the peelable film with sufficient heat and pressure to force the filler material to fill the holes. For thermoconductive filler the holes are filled sufficient for electrical connection through the holes. The filler material is abraded to the level of the foil and is then copper plated. The copper is patterned to form a wiring layer. A permanent dielectric photoresist layer is formed over the wiring layer and via holes are formed through the photoimageable dielectric over pads and conductors of the wiring layer. Holes are formed through the substrate and the photoimageable dielectric, walls of the via holes, and walls of the through holes are copper plated. The copper plating on the photoimageable dielectric is patterned of form an exterior wiring layer. Components and/or pins are attached to the surface of the circuitized substrate with solder joints to form a high density circuit board assembly.
Abstract:
A method for packaging and testing a semiconductor die is provided. The method includes forming a temporary package for the die that has a size, shape and lead configuration that is the same as a conventional plastic or ceramic semiconductor package. The temporary package can be used for burn-in testing of the die using standard equipment. The die can then be removed from the package and certified as a known good die. In an illustrative embodiment the package is formed in a SOJ configuration. The package includes a base, an interconnect and a force applying mechanism. The package base can be formed of ceramic or plastic using a ceramic lamination process or a Cerdip formation process.
Abstract:
The external connections of an electro-optical display device are connected to a semiconductor driving device (13) by respective contact faces (12) of transparent conductor tracks (11). The conductor tracks (11) are provided with a metallic top coating (17) which extends to the proximity of the associated contact face (12). To suppress resistance variations in the conductor tracks with respect to each other and from device to device, the metallic top coating (17) continues in the direction of the contact face (12) in a form of, for example, a relatively narrow metal track (18) which extends across the contact face (12) but covers only a part thereof.
Abstract:
A process for producing laminated film/metal structures comprising bumped circuit traces on a non-conductive substrate wherein a copper sheet/polyimide film laminate is coated with resist on the exterior surfaces. The resist adjacent the polyimide film is selectively exposed and etched to expose an area of the polyimide film. The exposed polyimide film is etched to form vias through the polyimide film to the inner side of the copper sheet. The resist adjacent the polyimide film is stripped away and a metal bump is electrolytically plated through each via onto the copper sheet. A subsequent layer of resist is electrophoretically applied over the bumps. The resist material adjacent the copper sheet is then selectively exposed and etched to expose areas of the copper sheet. The exposed copper sheet is etched to form circuit traces and the remaining resist adjacent both the polyimide film and the copper sheet is stripped away.
Abstract:
A method of making a circuitized substrate wherein a dielectric layer is provided having a first layer of metallic material thereon. A first metallic member is formed on the dielectric's metallic layer, following which a pair of openings are precisely provided within a second dielectric material located on the dielectric. These openings in turn define a selected area on the first metallic member and, significantly, a precisely oriented pattern of the first metallic layer at a spaced distance from the metallic member. This metallic pattern serves as a mask to permit formation of an opening through the dielectric, which opening in turn may be engaged by tooling or the like such as may be used to position an electronic component, e.g., semiconductor device, on the underlying substrate. The invention thus assures precise orientation and placement of components such as semiconductor devices on highly dense circuit patterns such as those required in the present art in the manufacture of devices such as those of the information handling system (computer) variety.
Abstract:
A method for manufacturing printed circuit board by forming wiring pattern by chemical metal plating using a negative pattern made of a photosensitive resin composition layer as the plating resist, wherein the photosensitive resin comprises at least a linear high polymer composed of repeating units expressed by the following general formula (1); ##STR1## where, R.sub.1 is H, an alkyl group having 1-9 carbon atoms, an alkoxy group having 1-9 carbon atoms, and a carboxyalkyl group having 1-9 carbon atoms, R.sub.2 is an alkylene group having 1-9 carbon atoms, and n is the polymerized number of the repeating unit, and an organic compound expressed by the following general formula (2); ##STR2## where, R.sub.3 is H or an alkyl group having 1-6 carbon atoms, X is NH or S, and Z is N or C--Y, where Y is H, NH.sub.2, or SH.
Abstract:
The invention provides a method for making an electrical circuit device as well as a resulting device itself. The method includes the steps of forming a base or substrate of conductive metal and then securing an electrically conductive masking element to the substrate. The resulting product is coated with a layer of fusible particles of a dielectric or resistive material that is repelled by the surface of the masking element. The coated product is then heated to fuse the particles and provide a hard dielectric or resistive layer over surface portions of the base. The masking element provides an exposed conductive path to the base metal or substrate. A section of conductive metal foil may be bonded to the masking element to provide a continuous conductive bus on the substrate.