Raychem Limited

Other

Nicholas J Smith

Michael J Ludden

Richard J Penneck

Peter Nyholm

Paul James Gibney

Stephen J Duckworth

James M O'Brien

Patrick J Horner

Edward A Keible

Polymer (preferably polyimide) sheets with laser ablated through-holes plated with metal are used for making electrical connections to specified microcircuits, especially unbumped microchips and Tape Automated Bonding (TAB) articles. Bonding with different melting-point materials at opposite ends of the plated holes is disclosed. Preferred polyimides are those derived from polymerisation of 4-4'-biphenyldianhydride and (4,4'-diaminobiphenyl, or 4,4'-diaminobiphenylether, or phenylenediamine, preferably p-phenylenediamine).

Uses of uniaxially electrically conductive articles

The present concepts include '1:1' uniax (40) with one conductive through-hole per chip connection site, 'mirror chip' testing, heat-sink bonding to chips, avoiding contact with conductive cleaved edge of chip, indium solid columns, metal recessed (41) in the through-holes. All of these are subject to preferred materials (UPILEX polyimide) and techniques (U.V. laser ablation, minimum taper of holes).

Polymer (preferably polyimide) sheets (10) with laser ablated through-holes plated with metal (20) are used for making electrical conections to specified microcircuits, especially unbumped microchips and Tape Automated Bonding (TAB) articles. Bonding with different melting point materials at opposite ends of the plated holes is disclosed. Preferred polyimides are those derived from polymerisation of 4,4'-biphenyldianhydride and (4,4'-diaminobiphenyl, or 4,4'-diaminobiphenylether, or phylenediamine, preferably p-phenylenediamine).

Laser-machining polymers

Processing microchips

Laser machining

An article of manufacture, for example a conductor for an electrical wire or cable, is provided with a refractory coating preferably formed from a refractory metal or semi-metal oxide or nitride and preferably deposited on the surface of the article by a vacuum deposition process such as a sputter ion plating method. Adhesion of the refractory coating, especially at high temperatures may be improved, and migration of the substrate metal through the coating may be suppressed by varying the stoichiometry of the coating through its thickness and/or by the provision of a metallic or refractory intermediate layer. The articles are particularly suitable for use in circuit and signal integrity cables. The vacuum deposited refractory layer may constitute the sole refractory, or additional refractory layers may be deposited by other methods e.g. a sol-gel method.

Wire and cable

Laminar polymeric sheet

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Cricklade, United Kingdom

Nicholas J Smith