Abstract:
An outer coating of an electrically conductive material having low wetability with respect to solder is deposited over a gold coating previously deposited on an electrical contact element. After soldering the contact element to a substrate, the portion of the outer coating not covered by solder is removed from the contact element. The method of joining a contact element to a substrate in accordance with the present invention effectively solves the problem of solder climb to the critical contact area of the element without the need to provide masking or apply plating resist coatings to selected areas of the element.
Abstract:
The present invention provides a method and apparatus for metallizing vias in co-fired ceramic green tape. A vacuum operated pick and place anvil comprising a porous block is used to pick up conductor balls from a bed. Air pressure is used to create a vacuum which pulls the conductor balls to the porous block. A stencil having openings is placed on a contact surface of the anvil, thereby permitting only one conductor ball to attach to each opening in the stencil. With the conductor balls attached to the anvil, the anvil is lowered onto the green tape. Next the anvil pushes the conductor balls into the tape until the conductor balls break through the opposite side of the tape. The anvil is retracted leaving the conductor balls lodged in the tape. It is possible to provide a green tape with pre-formed vias so that forcing the conductor balls into the tape is a simpler task. The locations of the openings in the stencil determines the location of the vias or must correspond to the vias in a tape having pre-formed vias. If the conductor balls protrude from any surface of the tape, the anvil or similar device can be used to flatten the protrusion. In alternative embodiments, the present invention conductor balls can be substituted with a material having a high thermal conductivity, or a high dielectric constant, or to include ferrite.
Abstract:
A multilayer microelectronics module formed by laminating together individual thermoplastic polymer sheets formed by injection, compression or other suitable molding techniques. Metal pieces to form vias of a desired shape and size are inserted into the molded sheets, preferably by in situ insert molding. The vias provide an electrical connection from the top to the bottom surfaces of the sheets.
Abstract:
A multi-layer wiring assembly including a stack of insulating layers, e.g. of polyimide, alternating with wiring patterns, typically of copper. To establish the circuit pattern, successive wiring patterns are connected to one another through the intervening insulating layers at predetermined locations, by metal stud connections. The studs are formed during assembly of the stack by wire-bonding a stud onto an underlying wiring pattern through a through-hole of the insulating layer above, and then stamping the exposed end of the wire-bonded stud to spread it into contact with the uppermost wiring pattern. The wire-bonded studs e.g. of Au, form strong bonds with the underlying conductor and are quick to apply in an automated process using a wire-bonding machine.
Abstract:
A process is provided where a ceramic metal substrate is produced by attaching metal foils on either side a ceramic layer to form metal layers and for producing a through connection by placing metal in an opening to form a bridge so that the metal layers are electrically connected together by direct bonding, and a metal body is inserted into the opening to almost fill it, while a surface of the metal body is provided with a layer with chemical compound of metal and reactive gas.
Abstract:
An improved connection through a substrate layer is formed by embedding a conductive element such as a pin on one or more balls or spheres in a thermoplastic material which is preferably a liquid crystal polymer. The substrate may be heated to facilitate the embedding process in which material of the substrate layer is reflowed under pressure to retain the conductive element by means of a preload force. The formation of such connections with either pins or plural conductive elements allows independence of aspect ratio of the connection and, hence, feature size of conductive patterns on the substrate and the thickness of the substrate layer. Perfecting features of the substrate and method and apparatus for forming the substrate, embedding to a selected depth to form protrusions and recesses to assist in registration of a substrate layer with another substrate layer, metallization to form pads, improved connection between metallization patterns on the substrate and the conductive elements, the regulation of pressurization of substrate material by means of differently shaped dimples or a renewable surface and several alternative arrangements for positioning and embedding the conductive elements. Multiple types of conductive elements may be simultaneously embedded to different depths in a single substrate and from either or both sides thereof to form a variety of substrate structures.
Abstract:
Hybrid circuit formed of two circuits (1, 2) combined by spherical balls (10) with electric connection.The conductive tracks (6) the balls (10) connect do not adhere to the circuits (1, 2) at portions (11) situated around the balls (10). As a result, these portions (11) may be safely removed and the balls (10) are able to roll onto the circuits (1, 2) if the latter are subjected to a relative movement due, for example, to differential thermic cubical expansions. Thus, the balls (10) are not stressed.
Abstract:
Disclosed is a connector structure on a substrate which includes at least one first solder portion on the surface of the substrate; at least one second solder portion connected to each of the at least one first solder portions; and an epoxy layer disposed about the at least one first and second solder portions in such a manner as to cover the first solder portion and contact, but not cover, the second solder portion. Also disclosed is a connector structure on a substrate which includes at least one first solder portion on the surface of said substrate; at least one second solder ball portion connected to the at least one first solder portions; wherein the melting point of the second solder ball portion is relatively higher than that of the first solder portion. Finally, disclosed is a method of testing the solderability of the above structures.
Abstract:
The invention provides a sheet material adapted to make bonded electrical connection to an array of closely spaced conductive terminal pads. The material may be provided as a roll of an elongated flexible connector tape. The sheet material of the invention comprises a thin, flexible insulating substrate and a plurality of longitudinally-extending, regularly-spaced, metal conductive members. The sheet may also include an adhesive layer that may cover the conductive members or at least a portion of the conductive members may extend above the adhesive layer. The conductive members may be supported and held on the substrate or may be suspended in the adhesive, out of contact with the substrate.
Abstract:
A method of soldering leadless component carriers or the like to printed circuit boards uses a solder paste containing copper spheres in addition to particulate solder and flux. The solder is melted and the copper spheres are embedded in the resulting solder matrix, offsetting the carrier from the printed circuit board.