Showing papers on "Flexible electronics published in 1991"

Compact, wireless apparatus for electrically testing printed circuit boards

Abstract: A wireless test system is provided for simultaneously performing electrical tests on the opposite sides of a printed circuit board. Specially designed, double-ended pogo pins are utilized to electrically interconnect the top and bottom sides of the board under test to top and bottom printed circuit interface boards, positioned above and below the board being tested, which are electrically interconnected by a flexible printed circuit ribbon. Upwardly projecting test pins on a test and analysis circuit are engaged with contact points on the lower side of the bottom interface board to complete the wireless interconnection between the board being tested and the test and analysis circuit. The double-ended pogo pins are brought into operative engagement with the top and bottom sides of the circuit board being tested by a vacuum-operated actuation system which vertically moves presser bar members to mechanically effect pogo pin engagement with the circuit board being tested without directly exposing the board to the vacuum being created. The wireless system may thus be utilized to test printed circuit boards of either perforate or imperforate construction.

Metal-film laminate resistant to delamination

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.

Flexible printed circuit board having a metal substrate

Abstract: A flexible circuit board including a flexible substrate having an insulating polyimide sheet and a wiring pattern portion formed in a mounting portion and a wiring pattern portion formed in a connecting portion, and a metal substrate on which only the mounting portion of the flexible substrate is secured by means of a thermoplastic polyimide film. Electronic devices are mounted on the mounting portion of the flexible substrate and heat generated by the electric devices can be effectively dissipated through the metal substrate. The connecting portion of the flexible substrate can be connected to an external circuit by means of a connector provided at an edge of the connecting portion. Since the connecting portion is not secured to the metal substrate, connector pins having a large mechanical strength can be used and the connecting portion can be bent at will.

Method for manufacturing rigid-flexible circuit boards and products thereof

Abstract: A method for manufacturing rigid-flexible multilayer printed circuit boards and the products thereof. The method comprises the compression molding several layers of materials comprised of a rigid layer, a separation layer, a flexible insulating layer, adhesives, and conductive metal to form a laminate. Flexibility is provided in the printed circuit board by slots in the rigid layer which define the flexible region, the application of flexible insulating material over the defined flexible region, and the removal of the rigid material which occupied the defined flexible region (plug). As disclosed by the present method, a flexible insulating layer is provided in the flexible regions only without the use of preliminary laminates. This method does not require the use of pressure equalizing cushions and does not result in relief formation on an upper layer of conductive metal during compression molding. After forming the composite laminate, it may be shaped as desired, and plated through holes may be provided in the rigid layer by known techniques.

Method for manufacturing rigid-flexible multilayer circuit boards and products thereof

Abstract: A method for manufacturing rigid-flexible multilayer printed circuit boards and the products thereof. The method comprises the compression molding several layers of materials comprised of a rigid layer, a flexible insulating layer, adhesives, and conductive metal to form a laminate. Flexibility is provided in the printed circuit board by slots in the rigid layer which define the flexible region, the application of flexible insulating material over the defined flexible region, and the removal of the rigid material which occupied the defined flexible region (plug). As disclosed by the present method, a flexible insulating layer is provided in the flexible regions only without the use of preliminary laminates. This method does not require the use of pressure equalizing cushions and does not result in relief formation on an upper layer of conductive metal during compression molding. After forming the composite laminate, it may be shaped as desired, and plated through holes may be provided in the rigid layer by known techniques.

Portable telephone set housing having an illuminated switch panel

Abstract: A portable telephone set housing having an illuminated switch portion. A flexible printed circuit board having a membrane switch and a liquid crystal display is mounted onto a support base of the telephone set housing. Onto the flexible printed circuit board is placed a key top sheet having a plurality of key tops. A switch panel having a plurality of holes for inserting therein of the key tops is mounted onto the key top sheet. The switch panel includes a transparent resin plate having an ink coating formed on the surface thereof except for a portion corresponding to the position of the display portion. In the membrane switch portion of the flexible printed circuit board, a plurality of light emitting diodes are provided which are adapted to introduce light into the interior of the switch panel.

Flexible printed-circuit board

Abstract: PURPOSE:To obtain the board wherein it is provided with high conductivity for a long time and it is bend-resistant by a method wherein a circuit pattern is formed of a rolled and annealed foil in which the total content of lead and tin is in specific weight% as well as an electromagnetic-wave shielding layer, a jumper circuit and a through-hole circuit are formed respectively of specific conductive paints. CONSTITUTION:A rolled and annealed copper-alloy foil 1 in which the total content of lead and thin is 0.02 to 0.15wt.%, in which their respective contents are 0.006wt.% or higher, in which the content of oxygen is 0.0001 to 0.005wt.% and whose remaining park is composed of copper is heaved, pressurized and bonded onto a polyimide film 2. Thereby, a required circuit pattern 1 is formed. Then, through holes 5a are made in a first undercoat layer 4a with which circuits la are covered, the through holes a buried wish a specific conductive paint, and a through-hole circuit 5a is formed. Then, the first undercoat layer 4a is coated with another specific conductive paint, and a jumper circuit 6 is formed. In the same manner, an electromagnetic-wave shielding layer 7 is formed, and an overcoa5 layer 8 is formed on it.

Flexible circuit and a device for holding the flexible circuit in the folded state

Abstract: By folding two or more mutually connected strips (1-7) of flexible printed circuit film material, an elongated flexible printed circuit comprising a main strip (1,2,3) and one or more side strips (4,5,6,7) being produced, with a minimum waste of film material. For holding the flexible circuit in its folded state and controlling the bending radii of the strips, a holding clip (11) which locks automatically on the film material being provided.

Flexible printed circuit with raised contacts

Abstract: A flexible printed circuit with raised contacts is presented. In accordance with this invention, a flexible circuit is disposed on a substrate. The substrate includes a pattern comprised of a plurality of raised features. Similarly, the flexible circuit has a corresponding pattern comprised of a plurality of contact pads. The contact pads are disposed on the raised features to form the raised contacts. The raised contacts perfect registration between the contact pads and the contact surfaces of a mating electrical component (e.g., a surface mount integrated circuit) when a pressure connection system is employed.

Hydrostatic connector for flex circuits

Abstract: A connector system for interconnecting single or multiple pairs of flex circuits. A single pair of clamping bodies interconnects the respective ones of multiple pairs of electrical conductors in the form of conductor traces carried on respective pairs of flexible substrates, by pressing the flex circuits together between slender fluid-filled flexible bladders held in channels defined in the confronting sides of the clamping bodies. Alignment pins keep the flex circuits and clamping bodies aligned properly with each other, and alignment portions of the flex circuits correspond in thickness to that of the electrically interconnecting portions, to keep the flex circuits and clamping bodies parallel with each other. The clamping bodies are urged toward one another by clamping screws.

Flexible printed board for use in cameras

Abstract: The present invention has designed and constructed a flexible printed circuit board which has a surface portion on which is mounted an electronic component and also a board portion which is folded back over itself so as to overhang the electronic component mounting surface and in which a shield pattern is extended over at least a surface portion in opposing relationship with an electronic component and is electrically grounded in order to protect the electronic component from external electrical noise. Thus the present invention provides a flexible printed circuit board which is inexpensive to fabricate, can prevent the erroneous operation of the electronic component from external electrical noise and permits the efficient arrangement of electronic components.

Fabrication method for a winding assembly with a large number of planar layers

Abstract: Z-folding of flex circuits is presented as a method to fabricate a winding assembly having a large number of conductive and insulating layers. The process starts with a flexible sheet which contains a copper laminate bonded to an insulating laminate. Conductor patterns are then etched on the laminates and are interleaved and folded to realize the winding assembly. A large number of thin, wide turns can be connected in series or in parallel automatically during the patterning and etching processes, thus eliminating external soldering or conductive vias. Equations relating winding resistance to geometrical parameters are derived for design purposes. A product of the z-folding technique is shown, which is a transformer with a primary winding and one-turn center-tapped secondary windings. >

Test contact fixture using flexible circuit tape

Abstract: A test contact fixture which uses a flexible printed circuit tape to make contact to the integrated circuit and to a rigid printed circuit board which is part of the test equipment. The flexible printed circuit tape is held tightly against a hardened steel support allowing extremely accurate alignment both horizontally and vertically. The mounting plate provides a ground plane so that each lead may easily be configured as a 50 ohm transmission line. Leads of the integrated circuit under test are held in contact with the conductive lines on top of the flexible printed circuit tape by externally applied pressure allowing extremely rapid loading and unloading of the fixture. The body of the integrated circuit is held clear of the contact surfaces allowing heat control fixtures to be used to control the temperature of the integrated circuit during testing.

Cooling structure for electronics devices

Abstract: A cooling structure for LSI or the like devices to be mounted in a small size electronic apparatus housing. A main printed circuit board has mounted thereon first electronic devices with low heat generation; at least one auxiliary printed circuit board has mounted thereon a second electronic device with high heat generation, which is connected with one edge of the main printed circuit board (1) through a flexible printed circuit tape (5); a holder (6) fixed on the main printed circuit board (1) for resiliently supporting the auxiliary printed circuit board (2) at a distance above the former when the latter is turned over and is above the main printed circuit board (1) by bending the flexible printed circuit tape (5) so that a heat conductive surface of the second electronic device (4) is exposed outside. This printed circuit board assembly (A) is accommodated in a housing (B) made of a heat conductive material so that the heat conductive surface of the second electronic device (4) is brought into close and resilient contact with the inner wall (14) of the hosing (B).

Surface mounted components on flex circuits

Abstract: A process for preparation of electronic packages including printed circuits wherein the circuit portions of the package are formed from a web including a plurality of circuits maintained in an array during processing. Holding tabs are provided to maintain the integrity of the array, with the holding tabs being in the form of releasable retention tabs for temporarily holding the array together and accommodating multiple-up processing of the electronic package. For certain portions of the process, the web is separated into multiple-up circuit packages wherein the circuits are disposed within the central portion of the panel, and with the lateral edges and ends collectively defining an annular circuit-free zone. Multiple fiducial points are located within or around the circuit patterns, thereby eliminating or reducing the requirement for circuit-specific tooling and permitting multiple-up handling of the circuits in each array.

Method of producing flexible printed-circuit board covered with coverlay

Abstract: A flexible printed-circuit board covered with a coverlay is produced by bonding (a) a flexible printed-circuit board that comprises a flexible base having a surface bearing a circuit and (b) a polyimide film having a surface treated to increase adhering property and another surface not treated to increase adhering property, each of the surfaces being coated with an adhesive layer, with the adhesive layer on the surface treated to increase adhering property interposed between the polyimide film and the surface bearing the circuit, and then peeling off the adhesive layer coating the polyimide film on the surface not treated to increase adhering property.

Method of making injection-moulded printed circuit boards

Abstract: Injection-moulded printed circuit boards which have been obtained by injection-moulding thermoplastic materials onto the back of flexible circuits are of a particularly high quality if the conductor tracks have been produced on the flexible carriers employed by direct additive or semiadditive metallisation.

Flexible printed circuit board and coverlay film and manufacture methods therefor

Abstract: Disclosed herein is a flexible printed circuit board and coverlay film and a method for producing the same. The board and coverlay film have metal foil or parting paper adhered to a polyimide film using a two-layer thermosetting adhesive. The first layer of adhesive on the polyimide film is about 5 μm thick or less. The circuit board and coverlay film produced according to this invention have excellent bonding strength, thermal, chemical and weather resistance, as well as good insulating properties.

Fusible flexible printed circuit and method of making same

Abstract: A fusible flexible printed circuit includes one or more conductors extending along a flexible dielectric substrate. Each conductor is comprised of a layer of electrically conductive material and a layer of fusible material extending along part or all of said conductive layer. One or more gaps is formed in the conductive layer at location opposite a segment of the fusible layer so that electrical current flowing through each conductor is required to pass in its entirety through the layer of fusible material at the location of each gap in the layer of conductive material. The integral fuses are designed to specific electrical parameters and may be located randomly along circuit runs. Preferably, the circuit is reinforced at the locations of the fuses by metal support strips designed to minimize motion stress on the fuses and the fuses are sealed within bubbles in a protective overlay which capture debris when the fuses are blown. The use of such a circuit to incorporate a variety of fuses having different fuse ratings into the conductive paths of a flexible printed circuit is also disclosed, as is a method of making the fusible circuit.

Holder for soldering a flexible circuit board to a substrate

Abstract: This invention relates to soldering systems of the type that provide localized soldering through the use of lasers. Such structures of this type generally allow flexible printed circuit boards to be locally soldered to metallized ceramic substrates. These structures have applications in such areas as ultrasound equipment.

Polyimide resin film and method of making said film

Abstract: A resin film useful mainly for fabricating flexible printed circuits, and a method of producing same. In the process of fabricating a flexible printed circuit board, a copper foil(2) is thermally bonded to a resin film(1), and the copper foil(2) is then etched to a predetermined pattern, in which case the board is generally subject to some dimensional change. In order to minimize such dimensional change it is arranged that the ratio(a/b) of the linear expansion coefficient(a) of the resin film(1) in the direction of mechanical feed(MD direction) to the linear expansion coefficient(b) of the resin film(1) in a direction perpendicular to the MD direction (TD direction) is more than 0.2 but less than 1.0 and that the linear expansion coefficient in MD direction is 0.4-2.0× 10 -5 ° -1 . For such resin film is used a polyimide film containing more than 90% of a recurring unit expressed by a specified general formula. To produce such a resin film, film 1 is drawn by a factor of from 1.0 to 1.5 in MD direction and is also drawn by a factor of from 0.5 to 0.99 in TD direction.

Printed Circuits Design: Featuring Computer-Aided Technologies

Abstract: From the Publisher: This exceptional,all-inclusive design manual covers-in unequalled detail-all aspects of printed circuits and their applications,including how to design printed circuit boards for efficient,cost-effective manufacturing and how to design boards that incorporate surface-mounted components. Indispensable for all electronics engineers,this valuable working reference includes: basic considerations-background,overview,specification and standards,terms,and definitions; interconnecting structure selection-single-sided rigid printed wiring boards,double-sided rigid printed wiring boards,multilayer rigid printed wiring boards,flexible printed wiring boards,rigid/flexible printed wiring boards,molded printed wiring boards,and supported plane structures; material selection-base laminates,reinforcements,conductors,platings and coatings,supporting planes,and constraining cores; component selection-discrete components,integrated circuits,interconnect components,electromechanical components,and hardware; performance considerations-mechanical,electrical,thermal management,and environmental stability; through-hole technology-component mounting,land patterns,and conductor routing; surface mount technology-component mounting,land patterns,and conductor routing; clip-on-board technology-component mounting,land patterns,and conductor routing; design methodology-manual,computer-aided (CAD),and automated; documentation-logic diagrams,schematics,master drawings,and artwork.

Locking connector assembly

Abstract: A connector assembly for connecting a flexible printed circuit or flat conductor tape cable with exposed terminal pads to the thru-hole terminals of a PC board or second flexible printed circuit includes a socket and conductive posts. Corresponding first ends of the posts project into the socket and corresponding second ends of the posts project from the bottom of the header for insertion into the PC board or second flexible printed circuit terminals. A connector is mounted to the end of the flexible circuit or flat conductor tape cable and it has post-receiving passages for receiving the post first ends so that those ends are electrically connected to the terminals pads of the flexible circuit or flat conductor tape cable when the connector is inserted into the header socket. Provision is also made for locking the connector in the header socket.

Flexible printed circuit package and flexible printed circuit for incorporating in such a package

Abstract: A circuit package is disclosed including a flexible printed circuit (10) which overlies, and follows the contour of, a carrier (50) having a substantially zig-zag shaped surface. The flexible printed circuit of this circuit package is in the form of a tape having a periodic, modular wiring pattern extending along the length of the tape, with connection lands provided between adjacent wiring modules. The circuit package also includes a plug for maintaining the flexible printed circuit in place on the carrier. Circuit components (20) mounted on the flexible printed circuit abut planar portions of the zig-zag shaped surface of the carrier (50).

Method for connecting printed-circuit boards

Abstract: PURPOSE:To enable increase in connection pattern to be coped with even without increasing a connection surface of a printed wiring board by providing a connection part at a protruding part from a flexible printed circuit board and then making connection by overlapping connection parts which are provided on the back side of main connection surface of the printed wiring board. CONSTITUTION:A flexible printed circuit board 1 and a printed wiring board 8 are fixed by utilizing positioning holes 7a and 7b which are made in a flexible printed circuit board 1 and positioning holes, etc., which are made in a disposable printed circuit board added when producing the surrounding printed circuit board. Then, conductive patterns 2 are overlapped and connection parts are connected by soldering, laser welding, etc. Protruding parts 4a and 4b of the flexible printed circuit board 1 are bend toward back side of the main connection part and sub-connection terminal parts 5a and 5b provided at the protruding parts 4a and 4b and sub-connection terminal parts 12a and 12b on the printed wiring board 8 are connected, thus enabling increase in the number of connection patterns to be coped with.

Manufacture of polyimide base plate

Abstract: PURPOSE: To obtain a method for preparation of a polyimide base plate which enables preparation of a printed wiring board of high reliability, a flexible printed circuit and an automatic bonding tape and which has a large strength of adhesion between an electroless plating film and an electrolytic plating film CONSTITUTION: In a manufacturing method of a polyimide base plate having a conductive film provided on one or both surfaces of polyimide resin, a conductive thin film of a thickness 10μm or below or preferably 5μm or below is provided on the surface of the polyimide resin and then subjected to heat treatment of 300 to 500°C in an inactive atmosphere Subsequently, the surface of the conductive film is washed with a solution containing at least one kind of ions of hypochlorite, chlorite and perchlorate and then the surface of the conductive thin film is subjected further to electroplating, whereby the conductive film is formed COPYRIGHT: (C)1993,JPO&Japio

Method of assembly for the application of electronic components to flexible printed circuits

Abstract: A method of assembling electronic components to a flexible printed circuit in which a component supporting plate is formed of a rigid plastic material with fitted recesses in which the electronic components are seated. The flexible printed circuit is overlayed with an elastomeric pad, and the flexible printed circuit and pad are then sandwiched between the component supporting plate and a counterplate which is similarly made of a rigid plastic material. This presses the conductors of the flexible printed circuit against the contacts of the electronic components seated in the fitted recesses of the aforesaid counterplate.

Multi-layer flexible printed circuit board and its manufacture

Abstract: PURPOSE: To realize sufficient endorsement of quality after being bent with respect to a multi-layer flexible PCB. CONSTITUTION: A multi-layer flexible printed circuit board comprises inner layer patterns 21, 22 on a surface and a rear face of a core layer 20 having flexibility, further insulation layers 27, 28 having flexibility and further surface layer patterns 30, 31. A region 2 which is expected to be bent at the time of mounting has only the inner layer patterns 21,22 but has no surface pattern 30 and no through-hole 35. The surface layer pattern 30 and the through-hole 35 are exclusively provided on regions 5,6 which are not to be bent at the time of mounting. COPYRIGHT: (C)1992,JPO&Japio

Flexible circuit board

Abstract: PURPOSE: To easily bend a flexible circuit board, to reduce a height required for bending, to reduce in size a device smaller, to alleviate a stress generated at a connector for bending, and to increase reliability of the connector CONSTITUTION: In a flexible printed circuit board 4 in which a metal wiring material 2 is provided on a board material 1, a cutout 3 is provided partly at the material 1, and the rigidity of the cutout 3 is reduced as compared with that of other part COPYRIGHT: (C)1992,JPO&Japio