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: An apparatus is described for electrically connecting flip chips to a flexible printed circuit substrate. The apparatus comprises (1) providing solder paste to a plurality of active contact pads located on the flexible printed circuit substrate, (2) placing the flip chips on the substrate such that solder bumps located on the flip chips are in registration with the solder paste on the active contact pads, and (3) heating the resulting assembly as a whole so that the solder paste on each active contact pad fellows to form an electrical connection with its corresponding solder bump.

Abstract: An improved flexible circuit assembly arranged in stripline cable or microstrip configuration with shielding and also being designed with a predetermined characteristic impedance. The flexible printed circuits function as printed cables, and employ spacers on either side of the circuit traces so as to provide ground planes at a predetermined dimensional spacing from the traces comprising the circuit pattern. The arrangement of the present invention further comprises placing two or three individual conductor panels on a common substrate, so as to accommodate folding of the circuit panels, one over the other, to form a multi-layer sandwich. Elongated slots are formed along the fold lines so as to improve the integrity of the assembly, and to reduce buckling.

Abstract: A method is described for electrically connecting flip chips to a flexible printed circuit substrate. The method comprises (1) providing solder paste to a plurality of active contact pads located on the flexible printed circuit substrate, (2) placing the flip chips on the substrate such that solder bumps located on the flip chips are in registration with the solder paste on the active contact pads, and (3) heating the resulting assembly as a whole so that the solder paste on each active contact pad reflows to form an electrical connection with its corresponding solder bump.

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 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.

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 process for fabricating a multi-layer flex and rigid-flex board and the board disclosed which substantially reduces the amount of expansion in the direction perpendicular to the plane of the board which occurs between laminated pattern circuit layers in a manner that substantially reduces the tendency of the through-hole plated connections to fail. This is done without sacrificing the attributes of using some flexible material in the rigid zones.

Abstract: An apparatus and method for preparing conductive bridges to electrically couple discrete electrical conductors arranged on opposed surfaces of a common substrate. The method and apparatus utilized includes subjecting the bore or opening in the substrate to the force of vacuum applied through a vacuum diffusion barrier. The substrate is exposed to the vacuum source through a plurality of spaced-apart bores of relatively small diameter, with the vacuum diffusion layer being in the form of a web of filter paper tracking and moving in synchronism with the substrate. Conventional silk screening techniques are utilized to form the conductors and bridges, with polymer thick conductive fluids being employed as the printing medium. Multiple layers of conductors may be formed, with dual-sided circuitry being applied to the substrate.

Abstract: An electrically conductive adherent film-forming adhesive which is rapidly curable thermally from a flowable liquid to an adherent and coherent solid at temperatures below about 120.degree. C. and with a specific resistivity of less than about 0.001 ohm-cm. when cured, and comprising a uniform mixture with a formulation containing a liquid epoxy base resin, a hardening component for the epoxy resin consisting essentially of B.multidot.CF.sub.3 SO.sub.3 H, and silver metallic powder in an amount ranging from about 75% to 85%, with the powder having a substantial uniform particle size of less than about 20 microns (0.8 mil) in diameter.

Abstract: A keyboard having a side-lighted transparent support plane including a plurality of light-pipes vertically projecting therefrom through an overlying foam over-travel pad. A pair of patterned membrane switch layers, separated by a low density foam spacer, overly the over-travel pad and are positioned relative to a plurality of key-caps slidably mounted to the light-pipes. The sensation of key travel is achieved via the over-travel pad and/or a foam spring mounted beneath the key-caps with switch contact being made intermediate full key depression. An audible click is achieved via overlapping slidably abrasive projections.

Abstract: A membrane switch having a first flexible substrate segment with a pattern of conductive elements thereon at discrete coordinate locations and overlaying this substrate is a spacer layer having a plurality of apertures arranged on the same center-to-center spacing as the conductive elements on the spacer substrate. This spacer layer has the same general shape as the substrate but is of a smaller size so that when superposed on the substrate with the hole pattern aligned with the conductive elements, a border of the first substrate is exposed beyond the edges of the spacer member. Disposed atop the apertured spacer member is a further segment of flexible material also having a pattern of conductive elements at discrete coordinate locations corresponding to the coordinate locations of the conductive elements on the first substrate. When this further segment is superimposed upon the spacer layer, its conductive elements are aligned with the apertures in the spacer layer and face those on the first substrate.

Abstract: An improvement in the method of preparing a coating or layer of reprographic material upon a substrate which includes the conventional steps of coating the substrate surface with a layer of resinous binder curable upon exposure to radiant energy including electron beam and ultraviolet radiation, the binder layer containing reprographic solids. The resinous binder is applied as a fluid and is irradiated until a coherent and adherent layer is formed. The method includes the steps of forceably applying and tautly maintaining a sheet of a smooth flexible film against the surface of the curable resinous binder while directing a beam of radiant energy through the sheet and onto the binder while the layer of flexible film is held thereagainst. The exposure to radiant energy is continued until the resinous binder is substantially completely cured, whereupon the sheet of flexible film is removed from the surface of the binder.

Abstract: A membrane switch comprised of first and second flexible layers having corresponding patterns of metallization thereon, these layers being separated by an apertured spacer. The first layer is of a larger size than the spacer and the second layer is of a smaller size than the spacer so that when the three are superposed, a border on the first layer and spacer are exposed to meet the second layer. Completing the assembly is a label layer which is of a flexible, non-conductive material having a desired pattern of graphics printed on it and an adhesive coated undersurface. When the label layer is pressed against the exposed surface of the second substrate, it bonds all three of the lower layers together and creates a seal around the perimeter of the switch assembly. With the label layer being of a greater size than the other three layers, it may also be used to affix the composite switch to the appliance on which it would be used.

Abstract: A composite top membrane designed for use with membrane-type switch arrays which is substantially smooth and ripple free. The composite membrane comprises:(1) a layer of plastic foam which is coated on each side with a pressure sensitive adhesive;(2) a decorative cover layer formed from plastic and having graphic indicia on one or both surfaces and which is adhesively affixed to one side of the aforementioned layer of plastic foam; and(3) a sheet of plastic having a significant memory property having its first surface adhesively affixed to the other side of the foam layer and a pattern of conductive metallization on its second surface.The layer of foam material provides a flat, resilient interface between the decorative cover layer and the relatively convoluted surface of the flexible printed circuit top membrane. As such, the decorative layer remains flat and free from optical irregularities which would detract from its aesthetic impression.

Abstract: A splicing system for the butt splicing of endless flexible abrasive belts which employs an adhesive having a multiplicity of unidirectionally oriented reinforcing fibers spanning the butt-joint to form a durable long lasting splice. The fibers which are embedded in a cohesive member form a reinforcement strip which is bonded to the abrasive belt surface. The fibers are high-modulus organic fibers, preferably having a tensile modulus in excess of about 15.times.10.sup.6 psi, and with a tensile strength in excess of 200,000 psi.

Abstract: A braking system for applying a controllable braking force to the support shaft of a film supply roll, wherein the braking force is proportional to the weight of film remaining upon the supply roll, and wherein the braking force decreases as the supply of film remaining on the supply roll decreases. The system utilizes a pair of brake yokes which are mounted on opposed sides of the frame of an unwind stand, with each brake yoke having a generally "U" configuration, and with the support shaft for the film supply roll being received within the "U" shaped member. The yokes are mounted upon rams which are controllably elevated, and when elevated, a friction pad which lines the inner periphery of the yoke makes contact with the support shaft. The rams are arranged to reciprocatorily raise and lower the yokes for bringing the friction material into and out of contact with the support shaft so as to provide controlled braking when required.

Abstract: A universal printed circuit pattern of conductors for use in connection with diaphragm-type push button electrical switch panels which allows the printed circuit board to be physically sheared along plural axes to accommodate switch panels of varying sizes without destroying electrical continuity of the ground or common conductor thereon.

Abstract: A touch panel diaphragm-type switch array providing improved tactile feedback. A rigid substrate having a printed circuit conductor pattern thereon, with the pattern defining a plurality of switch locations, each including first and second separate electrical contacts is provided and superimposed thereover is a spacer having apertures in registration with the electrical contact pairs. Sandwiched between the substrate and the spacer is a thin layer of a suitable plastic material which is deformed in the areas defined by the apertures in the spacer to define dome-shaped projections surrounded by an annular ring. A bridging conductor is disposed on the underside of the dome-shaped projections. "Spider" members are supported by the side walls of the apertures and are disposed between the outer side of the dome-shaped projections and a flexible plastic cover layer which is affixed to the top side of the spacer layer. The cover layer is imprinted with indicia to visually define the switch positions.

Abstract: A tactile layer for use in combination with diaphragm-type switch keyboards to impact a tactile signal to the user upon depression of a key. The tactile layer comprises a sheet of Mylar polyester material having integrally formed deformations therein wherein the deformation is in the form of an annular ring hingedly supporting a dome shaped projection about a generally circular transition line, the transition line being displaced a first predetermined distance from the plane of the sheet which is less than the distance which the top of the dome shaped projection is displaced from the plane of the sheet.