Abstract: A new process for electrically and mechanically joining arrays of conductors on flexible printed circuits and other flexible conductors including collated flat, flexible cables (FFCs). An array of flat copper conductors on a flexible dielectric sheet is electroplated with tin-lead solder. Surface insulation is locally omitted or removed from conductor surfaces. A second circuit or cable is overlapped in competent electrical communication and the solder plating fused by inductively heating the copper to join the two conductor arrays. An adhesive placed between conductors is also thermally activated to bond the film on the two cable arrays together. This insulates the electrical connections and seals them from attack by moisture and chemical pollutants.

Abstract: Disclosed is a new process for electrically and mechanically joining arrays of conductors on flexible printed circuits and other flexible conductors including collated flat, flexible cables (FFCs). An array of flat copper conductors on a flexible dielectric sheet is electroplated with tin-lead solder. Surface insulation is locally omitted or removed from conductor surfaces. A second circuit or cable is overlapped in competent electrical communication and the solder plating fused by inductively heating the copper to join the two conductor arrays. An adhesive placed between conductors is also thermally activated to bond the film on the two cable arrays together. This insulates the electrical connections and seals them from attack by moisture and chemical pollutants.

Abstract: A charge transfer load sensor. A first and second electrode are disposed a fixed distance apart, and a third electrode is disposed between the first and second electrodes. The third electrode is grounded and its position between the first and second electrodes varies in response to an applied force. A switch arrangement applies a predetermined voltage level to the first electrode and couples the second electrode to ground during a first predetermined timing interval. During a second predetermined timing interval, the first electrode is coupled to the second electrode to transfer the charge of a first capacitor formed by the first and third electrodes to a second capacitor formed by the second and third electrodes. An output port coupled to the second electrode provides an output voltage as a function of the applied force.

Abstract: A flexible metal-film laminate can comprise a layered film structure having a metal layer securely bonded to a film layer. The laminate contains a unique metal-oxide attachment structure between the film and metal layer comprising randomly distributed regions of metal-oxide. After the metal/metal-oxide layer, a chromium metal or chromium alloy layer is formed before subsequent layers of copper, gold, etc. The peel strength of such a laminate is significantly improved over prior laminates and is resistant to peel strength reduction due to environmental stress. The preferred metal-film laminates made with polyester or polyimide can be used in the manufacture of high-quality, low cost, flexible printed circuit boards.

Abstract: A flexible capacitor is used in a switch circuit arrangement for activating a vehicle horn. The switch circuit arrangement includes an astable circuit having a flexible capacitor. The astable circuit generates a signal having a frequency that varies in response to force applied to the capacitor. A programmed frequency sensor activates a horn activation signal if the frequency of the signal falls below a programmed threshold.

Abstract: A printed circuit, chip carrier or other substrate for an electronic power circuit can comprise a heat transfer device engineered to dissipate heat generated from the electrical operation of the circuit. The heat transfer characteristic or heat sink capacity of the device results from formation in a polymer film of an array of cylindrical metallic portions in the film that draw heat from the circuit package. We have found that by forming such an array of metallic cylinders wherein each cylinder has a diameter less than about 25 .mu.m, the array defined by a distance on center of about 50-125 .mu.m has a substantial heat transfer characteristic. We have found that when the polymer film has the array of metallic cylinders within the film to a degree that at least about 8%, preferably 10-15% of the surface area of the film is occupied by the metallic cylinder, that the heat transfer characteristics of the film is virtually identical to copper metal.

Abstract: A method for preparing a castable amorphous fluorocarbon coating upon the surface of a substrate which includes the steps of initially depositing a film of a fluorocarbon having a thickness between about 1500 .ANG. and 50,000 .ANG., and thereafter applying a second coating as a coverlay upon the initial film. Both the initial film and the castable coating consist of an amorphous fluorinated (ethylenic-cyclo oxyaliphatic substituted ethylenic) copolymer having the structural repeating unit: ##STR1## wherein "m" and "n" represent integers providing a molecular weight of between about 230,000 and 500,000, with the relative values of "m" and "n" providing a copolymer with a glass transition temperature ranging from between about 160.degree. C. and 240.degree. C.

Abstract: A metallized laminate material for the manufacture of high performance, high density printed wiring boards and the like includes an ordered distribution of via holes electrically interconnecting opposing conductive layers on a dielectric polymeric film substrate. Furthermore, opposing photoresist layers substantially cover the conductive layers and vias. The conductive material in the conductive layers and the vias is bonded adhesivelessly to the substrate to provide a high degree of delamination resistance. The production of metallized laminate material is preferably carried out in a roll-to-roll process suitable for high volume, low cost production. In use, an end user may manufacture customized printed wiring boards in small volume runs from the laminate material with a reduced amount of equipment, expertise and cost.

Abstract: Flexible multilayer printed circuit boards are disclosed which utilize adhesiveless laminates interconnected in a generally superposed relationship by a conductive adhesive. In one embodiment, the adhesiveless laminates have relatively thin conductive layers and metallized through holes which exhibit high delamination resistance. The metallized through holes preferably have a thickness of at most about 25 microns, yet they are capable of withstanding multilayer assembly processes. High flexibility, reliability, packaging density, and environmental resistance are consequently available in a thin multilayer construction. In a further embodiment, adhesiveless dielectric layers are interposed between adhesiveless laminates to electrically insulate portions thereof. The adhesiveless dielectric layers may define relatively small apertures therein, thus providing greater packaging density for a multilayer printed circuit board.

Abstract: An electronic assembly containing an active circuit, an insulating layer and a heat sink. The insulating layer comprises an unfilled thermoplastic sheet having adhesive layers on opposite sides of the sheet. The adhesives are filled with thermally conductive material while the film is unfilled. The properties of the insulating layer are such that the thermal impedance is low while dielectric strength is high. These improved films reduce costs, improve thermal and electrical properties. The layers of the invention are particularly useful for single or multiple layer printed circuit boards having surface mount components in conjunction with a sheet like aluminum heat sink.

Abstract: An electronic assembly containing an active circuit, an insulating layer and a heat sink. The insulating layer comprises an unfilled thermoplastic sheet having adhesive layers on opposite sides of the sheet. The adhesives are filled with thermally conductive material while the film is unfilled. The properties of the insulating layer are such that the thermal impedance is low while dielectric strength is high. These improved films reduce costs, improve thermal and electrical properties. The layers of the invention are particularly useful for single or multiple layer printed circuit boards having surface mount components in conjunction with a sheet like aluminum heat sink.

Abstract: A heat resistant multilayer circuit board used in the transportation environment in cars, boats, planes, etc, having two or more conductive layers, with at least two conductive layers electrically and mechanically connected by an interconnecting adhesive layer, at least one of the conductive layers being affixed to a heat resistant substrate. The interconnecting adhesive layer comprises a conductive adhesive material having a plurality of deformable, heat fusible metallic particles dispersed substantially throughout a non-conductive adhesive. The fabricated multilayer circuit boards have interconnections which are reliable, heat resistant, and capable of withstanding thermal cycling and typical circuit board finishing and assembly processes.

Abstract: A printed circuit assembly includes a fine pitch flexible printed circuit overlay bonded to a normal pitch printed circuit board. The fine pitch flexible printed circuit overlay may provide increased packaging density, direct chip attachment and/or complex routing with a minimal cost impact on the overall printed circuit assembly.

Abstract: A printed wiring board includes a photoimageable dielectric material (PID) utilized as the base dielectric substrate therefor. The photoimageable dielectric material may be utilized in many conventional PWB designs, and improved resolution and registration precision of access apertures and through holes is generally realized through the use thereof. Moreover, less costly and complex manufacturing processes are required to deposit, image, develop and cure the PID material.

Abstract: A multilayer circuit board having three or more conductive layers, with at least two conductive layers electrically and mechanically connected by an interconnecting adhesive layer, is disclosed. The interconnecting adhesive layer comprises a conductive adhesive material having a plurality of deformable, heat fusible metallic particles dispersed substantially throughout a non-conductive adhesive. The fabricated multilayer circuit boards have interconnections which are reliable, heat resistant, and capable of withstanding thermal cycling and typical circuit board finishing and assembly processes.

Abstract: A printed circuit assembly and a method of manufacturing therefor are provided for directly connecting unpackaged integrated circuit chips such as flip chips to a footprint of active contact pads on a printed circuit substrate. A reduction in packaging density is obtained by electrically interconnecting one or more of the active contact pads with circuit traces formed on different layers of the printed circuit substrate. In a preferred embodiment, at least one of the active contact pads includes an electrically conductive through hole electrically connecting the contact pad and a circuit trace located on the back side of a double-sided printed circuit substrate. In another embodiment, the printed circuit substrate is a multilayer construction, which enables active contact pads to be electrically interconnected with circuit traces on a plurality of circuit layers.

Abstract: Flexible multilayer printed circuit boards are disclosed which utilize adhesiveless laminates interconnected in a generally superposed relationship by a conductive adhesive. In one embodiment, the adhesiveless laminates have relatively thin conductive layers and metallized through holes which exhibit high delamination resistance. The metallized through holes preferably have a thickness of at most about 25 microns, yet they are capable of withstanding multilayer assembly processes. High flexibility, reliability, packaging density, and environmental resistance are consequently available in a thin multilayer construction. In a further embodiment, adhesiveless dielectric layers are interposed between adhesiveless laminates to electrically insulate portions thereof. The adhesiveless dielectric layers may define relatively small apertures therein, thus providing greater packaging density for a multilayer printed circuit board.

Abstract: A multilayer circuit board having three or more conductive layers, with at least two conductive layers electrically and mechanically connected by an interconnecting adhesive layer, is disclosed. The interconnecting adhesive layer comprises a conductive adhesive material having a plurality of deformable, heat fusible metallic particles dispersed substantially throughout a non-conductive adhesive. The fabricated multilayer circuit boards have interconnections which are reliable, heat resistant, and capable of withstanding thermal cycling and typical circuit board finishing and assembly processes.

Abstract: A flexible metal-film laminate can comprise a layered film structure having a metal layer securely bonded to a film layer. The laminate contains a unique metal-oxide attachment structure between the film and metal layer comprising randomly distributed regions of metal-oxide. The peel strength of such a laminate is significantly improved over prior laminates and is resistant to peel strength reduction due to environmental stress. The preferred metal-film laminates made with polyester or polyimide can be used in the manufacture of high-quality, low cost, flexible printed circuit boards.

Abstract: A multilayer rigid-flex circuit board having two or more conductive layers, with at least one rigid circuit board electrically connected to at least one flexible jumper connector or intercircuit connector circuit board, is disclosed. A conductive layer of each of the rigid circuit boards is connected electrically and mechanically to a conductive layer of the flexible jumper connector by an interconnecting adhesive layer. The interconnecting adhesive layer comprises a conductive adhesive material having a plurality of deformable, electrically conductive particles dispersed substantially throughout a non-conductive adhesive. The fabricated multilayer circuit boards have interconnections which are reliable, heat resistant, and capable of withstanding the mechanical strain of the interconnection and the thermal cycling and typical circuit board fabrication, finishing and assembly processes. Such a rigid-flex circuit is typically used in an environment where space is limited.