Abstract:
A subtractive process for the fabrication of cylindrical printed circuit boards is presented. Layers of metal and dielectric are sequentially placed on the outside of a cylindrical form. The form may be rotated about its longitudinal axis during many of the process steps allowing automatic application of dielectric and metal layers and also allows controllable curing and etching processes.
Abstract:
The invention relates to an electrically conductive unit having electrically conductive paths, which are directly or indirectly applied onto a case for creating a screening against electromagnetic radiation and for the draining of electrical currents.
Abstract:
A method is provided for applying a fluid to a plurality of locations on a non-planar substrate. The apparatus used includes a movable base and an array of pins connected to the base. Each pin has a distal end which is vertically movable with respect to the base independently of the rest of the array of pins. Each distal end is adapted to transfer fluid to a location on the substrate by having a greater affinity for the fluid than the fluid has for itself and a lesser affinity for the fluid than the fluid has for the substrate. Accordingly, the distal ends may be dipped in the fluid and moved into contact with the substrate such that the distal ends may collapse toward the base as the distal ends engage the substrate to facilitate further movement of the base toward the substrate for application of fluid to each of the plurality of locations.
Abstract:
An electronic module assembly (10) is constructed by attaching semiconductor die (20, 22) to corresponding ceramic substrates (16, 18). A solder preform (14) is placed between the ceramic substrates and a base plate (12) which in turn is placed on a mounting fixture (26). Steel shims (28-42) are placed around the perimeter between the base plate and the mounting fixture surface. A restraining mechanism (24) passes through the center of the base plate and fastens to the mounting fixture to create a force on the base plate causing it to bow in an elastic manner. The assembly is reflow soldered and cooled with the module assembly restrained in the pre-bow apparatus. The elastic bow compensates for differences in thermal expansion and contraction characteristics between the ceramic substrates and base plate encountered during the reflow and later processes to prevent stresses from developing on the solder bond between materials.
Abstract:
There is provided a soluble chemical layer affixed to a rigid backing, whereupon an electronic configuration is printed and covered with a lacquer. The pattern and lacquer coating are then separated from the backing by dissolving the soluble chemical. Once free, the pattern is transferred to and fused to the substrate.
Abstract:
Electret transducers, for example microphones, have a backplate which is metallized on one surface, the metallized surface forming one side of a capacitor. A frame sits on the metallized tape to hold the tape taut over the backplate. Metal connections are made to the backplate and frame to complete the circuit. The metallization is conventionally formed by vapor deposition of aluminum. This is a lengthy and relatively expensive process. Also the metallization can give rise to galvanic problems. The invention prints a pattern of conductive ink on the various parts. Good contact is obtained, galvanic action avoided and a reduction in manufacturing costs occurs. Simplified assembly is also obtained.
Abstract:
A print head of the dot matrix impact type is provided with a plurality of solenoid assemblies arranged in a circular array about the rearward portion of the print head. A thin flexible printed circuit cable encircles the solenoid assemblies and has imbedded therein thin flexible wires each terminating at one end in an exposed connecting terminal and connected at their opposite ends to a connector plug mounted upon the cable and adapted to releaseably receive a mating connector. Embedded in the cable are a plurality of flat rigid plates serving as a stiffening member, interlocking tab and tab receiving members, a clamping member having an elongated embracing tab and a locating member having a pair of locating tabs for positively locating and orienting the printed circuit cable relative to the solenoid assemblies and for securing the locating member to one of the solenoid assemblies to prevent the cable from sliding about the print head solenoid assembly array.
Abstract:
The composite part is constituted by a plate of flexible material such as plastic which has electrical and/or thermal insulating properties, at least one face of the plate being provided with a metal cladding which is subjected to a photoetching process in order to form raised metallic portions corresponding to a printed circuit pattern, for example. Permanent deformation of the raised metallic portions can be produced by means of a mechanical cold-forming process without exceeding the range of elastic deformation of the flexible plate.
Abstract:
A device for bending sheets includes a first abutting member and a second abutting member fixedly connected to an outside surface of the sheet. The second abutting member is rotatably connected to the first abutting member. A rotating position and a locking position are provided at the connection between the first abutting member and the second abutting member. The first abutting member and the second abutting member are capable of rotating relative to each other at the rotating position, and the first abutting member and the second abutting member are capable of being interlocked with each other at the locking position. The first abutting member and the second abutting member are interlocked so as to obtain a desired curvature of the sheet. The present invention further provides an LED module and a display screen.