Abstract: Uniaxially conductive connector formed in situ on microchip by laser drilling an insulating layer at least 5 micrometers thick to provide holes communicating with the chip bonding sites, and depositing metal in the holes to establish electrical connection with the bonding sites. Excimer U.V. laser ablation of a polyimide insulating layer is preferred, followed by removal of a surface layer (preferably of amorphous polyamide from the insulating layer to expose the ends of the metal deposited in the holes.

Abstract: A close-fitting box (110, 120 FIG. 3) maintains a sheet (100) of mastic in sheet form for wrapping around a cable splice (FIG. 7) to supply large volume of mastic to fill the enclosure formed by applying a heat-shrinkable sleeve (250, FIG. 11) around the mastic-wrapped splice.

Abstract: An arrangement for enclosing the termination of a screened electrical cable to an electrical conductor comprises a coupling element, e.g. an adaptor (1) that is intended to engage the connector and is formed from a metal having a conductive passivate layer thereon, and a dimensionally recoverable article (2) for enclosing the termination after recovery onto the cable. The article (2) includes an electrical screen (8) and is partially recovered into engagement with the coupling element (1) so that an end of the screen (8) is in electrical contract with a portion (5) of the coupling element. The portion (5) of the coupling element has no passivate layer thereon.It has been found that the electrical resistance of the band formed between the screen (8) and the coupling element (1) is relatively constant during storage at elevated temperature.

Abstract: An electrical insulator comprising a cylindrical core (2) of an insulating refractory material, such as porcelain, onto a portion of the curved surface of which a sleeve (8) of insulating polymeric material is fitted. Metal end-caps (4), for electrically connecting the insulator, are fitted to the ends of the porcelain core such that there is an exposed portion (10) of the curved surface of the core between the sleeve and each end-cap. Thus, any damaging electrical activity which takes place at the metal end-caps is directed primarily onto the surface of the porcelain core (2), and not onto the surface of the electrically vulnerable polymeric sleeve (8), which serves to protect mechanically the relatively brittle porcelain core. Optionally, the polymeric sleeve (8) may have a convoluted or a shedded outer surface (12) to increase the leakage path length of the insulator, or to prevent the formation of a continuous moisture path, or both.

Abstract: A heating device for recovering a heat-recoverable plastics sleeve about a portion of a wire harness comprises a housing having a heating location when the portion of the harness and heat-recoverable sleeve are introduced, and a heating unit that is movable between a rearward position in which it surrounds the heating location. The heating unit comprises a pair of heating jaws (5,5') that open as they move toward the heating location and then close as they arrive at it so that the portion of the harness to be heated is completely enclosed within the heating unit. The jaws open again when they recede from the heating location to allow the harness to be removed.

Abstract: Electrically conductive polymers, especially polypyrroles, are formed with a charged polymeric dopant supplying the necessary counter-ions to stabilise the charged conductive form of the conductive polymer. The physical properties of the conductive polymer can thus be usefully modified in ways different from those achieved by non-polymeric dopants or by forming the conductive polymers in pre-existing bodies of non dopant (i.e. uncharged) polymers.

Abstract: An arrangement for enclosing a branch-off between a pair of cables (2,3,4) comprises a dimensionally recoverable sleeve (5) which can surround the branch-off, and one or more clips (6) which can be positioned about opposed walls of the sleeve to divide the sleeve into channels for the cables. The or each clip (6) is of unitary form and has a pair of legs (8) that are splayed outwardly to facilitate positioning of the clip over the sleeve walls. The or each clip is deformable so that the legs can be forced towards each other after the clip has been positioned on the sleeve walls but is sufficiently rigid, at least in its deformed state, it will resist opening out of the legs under the recovery forces of the sleeve.The invention provides a relatively simple and easy to install enclosure for branch-offs in harnesses for example that are intended to be used in automotive vehicles.

Abstract: Benzofuran-ether-sulphone monomers of formula ##STR1## and ether ketone polymers derived therefrom of formula ##STR2##

Abstract: An arrangement for enclosing a branch-off between two or more cables (11,12) comprises a dimensionally recoverable sleeve (1) which can surround the branch-off and a clip (6) having a pair of legs (8) that can be positioned about opposed walls of the sleeve to divide the sleeve into channels for the cables. The sleeve has one or more transversely extending ribs at its end and the clip has a profile, e.g. being provided with protuberances 9, such that it can be pushed onto the end of the sleeve and can be retained thereon by engagement of the rib(s).

Abstract: A number of arrangements for protecting an electrical circuit from an electrical overcurrent are disclosed. In the arrangements the base or gate of a switching transistor (4, 101, 161, 222, 401) is held in a voltage divider, one arm of which comprises a control transistor (6, 102, 162, 222, 404) whose base or gate is itself held in a voltage divider. When an overcurrent is experienced the control transistor switches on causing the switching transistor to turn off. The arrangement may include a shunt switching circuit to shunt the overcurrent across the load. It may include a resetting circuit that will attempt to reset the switching circuit after the overcurrent has been experienced. In one embodiment the arrangement includes means such as a battery, dc--dc voltage converter or Seebeck device in order to reduce or eliminate any initial voltage drop across the switching circuit.

Abstract: A high voltage insulator has a polymeric core that forms a mechanical strength member and an outer covering of a heat-shrinkable polymeric tube that is electrically insulating and non-tracking and that has sheds on its outer surface.

Abstract: A polymer composition comprises a solid fusible particulate polymer material and a quantity of metal particles that have been blended with the particles of polymer material to render the composition electrically conductive. The composition may be consolidated by subjecting the particulate blend to heat and/or pressure. The electrically conductive polymer composition may be used to connect the electrically conductive screen (7) of a dimensionally recoverable article (6) to the electrically conductive shield (4) of a cable (1).

Abstract: Apparatus for excimer laser image protection ablation of a target material comprising a projection lens system for projecting a mask pattern to be ablated onto the target, which lens system is telecentric towards the image (target) end of the projection path, and means for moving the target along the projection path whereby in use the size of the projected image areas to be ablated from the target is adjusted substantially without altering their relative portions of the target.

Abstract: A polymeric composition comprises:(i) an aromatic polyimide or an aromatic carboxylic ester polymer,(ii) a substantially wholly aliphatic polyamide, and(iii) a polyamide that contains both aromatic aliphatic moieties.It is found that the mechanical properties of blends of the aromatic polymers (i) and the polyamides (iii) can be significantly improved by the incorporation of a quantity of the aliphatic amides (ii), even though the miscibility of polymers, as observed by their glass transition temperatures may remain unchanged.

Abstract: A method of forming a branch-off seal between a heat-shrinkable sleeve and at least two spaced-apart elongate substrates, which comprises the steps of:(a) positioning the substrates within the heat-shrinkable sleeve;(b) positioning between the substrates and within the sleeve at an open end thereof a plug having a larger cross-sectional size at a first position away from said open end and a smaller cross-sectional size at a second position towards said open end;(c) positioning a heat-activatable sealing material at the first position;(d) shrinkable conduits in the sleeve by positioning one or more clips at the open end of the sleeve such that the substrates and the plug are in respective conduits; and(e) while the clip remains on the sleeve, applying heat so as to affect shrinkage of the sleeve to activate the sealant, and form the desired seal.

Abstract: Low tortuosity porous polymer sheets (25 to 2000 pores per square millimeter) with metal plated in the pores so as to project beyond sheet surfaces provide uniaxial electrical interconnects. A first "flash" layer of metal is electrolessly plated in the pores and the "flash" coating of metal is then removed from the sheet surface to isolate the pores electrically from one another. Further plating is then applied only to the already plated pore surfaces to fill the pores and/or project beyond the sheet surface. Solder may fill the plated pores. Polymer layers may be removed from the sheets to expose the metal in the pores. The articles are useful in making electrical connections to the contact pads of microcircuits during testing and assembly into electronic devices.

Abstract: Polyetherketoneimides and copolymers thereof having an imide repeat unit of formula ##STR1## wherein Ri is ##STR2## in which A is a direct bond or --O--or another substantially non-electron-withdrawing group, and/or Ra is an at least partly arylene moiety other than m- or P-phonylene.These polymers tend to have improved melt stability and other properties, especially when made from a pre-existing imide monomer, instead of by the known amic acid route which results in uncyclised amic acid residues in the polymer.

Abstract: An article for tape-automated bonding of integrated circuit microchips comprises a carrier sheet (22) carrying conductive tracks (23) with a tubular metal formation (21) passing through the sheet at the end of each track for connection to a microchip (24). The tubular formations tend to accommodate irregularities in the chip and may contain solder or other metal having a lower melting point than the tubular formation to effect bonding.

Abstract: 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.

Abstract: A sheet laminate of polyimide and amorphous polyamide especially suitable for making anisotropically electrically conductive articles by laser abiation drilling followed by metal plating. Preferred polyimides include those derived from polymerization of 4,4'biphenyldianhydride and 4,4'-diaminobiphenylether or p-phenylenediamine. Preferred amorphous polyamides include those derived from condensation of terephthalic acid with isomers of trimethylhexamethylenediamine.