Abstract:
A plurality of physically separate plastic substates are injection molded, each with at least one pattern of channels formed in a surface of thereof defining a conductive circuit to be formed. The plurality of substrates are then physically connected in a common planar array either by inserting them in corresponding receptacles in a carrier board, by mating peripheral connecting elements, by using adhesive or by some other suitable connecting mechanism. Where a carrier board with pre-formed receptacles is not utilized, the individual substrates in the array are pierced and replaced. The planar array is processed to simultaneously form a conductive circuit on each substrate consisting of metal deposited in its pattern of channels. The planar array of metallized substrates may then be stuffed with electronic components on an automatic insertion machine, wave soldered. The individual finished circuit boards are then pressed out. This batch processing results in substantial savings in handling costs and avoids the significant expense and tolerance problems associated with using very large molds which would be required to form the large planar array directly.
Abstract:
Process for preparing multilayer printed circuits comprising laminating to a substrate bearing a circuit pattern or electrically conductive surface a photosensitive layer which is tacky or becomes tacky upon exposure; exposing the laminate to actinic radiation through a via image related to the underlying circuit pattern, if present; optionally removing the removable via image of the photosensitive layer in either the exposed or unexposed areas, e.g., with a solvent or peeling apart by removal of a cover sheet, if present; laminating to the remaining tacky photosensitive layer a layer of a second photosensitive composition; exposing the laminate to actinic radiation through a registered image pattern of at least one overlying segment of the via image area and conductive circuit pattern to form an image surface having nontacky areas and removable circuit image areas; removing the removable circuit image areas of the photosensitive layer in the exposed or unexposed areas with a solvent therefor, or peeling apart by means of a cover sheet, if present, the removable via image areas of the lower photosensitive, if present, are removed by a solvent therefor; embedding finely divided material, e.g., copper, into the tacky areas; optionally curing the laminate by means of actinic radiation and/or heat; plating electrolessly to form an interconnected electrically conductive circuit. Additional circuit layers can be added.
Abstract:
A process for producing printed circuit boards having metallic conductor structures embedded in the insulating substrate and whose front and back sides are conductively connected by means of plated through holes. The first steps of the process comprise producing a matrix on an epoxy resin substrate consisting of a lift-off layer, an aluminum barrier layer and a positive photoresist layer. A negative image of the desired conductor pattern is then generated in the photoresist layer using conventional photolithographic techniques. The negative image is etched into the barrier layer and the lift-off layer such that an undercut occurs under the barrier layer. Subsequently, vertical trenches are etched into the epoxy resin substrate. After drilling of the through holes, an activating layer of copper is deposited by means of magnetic field enhanced cathode sputtering on the surfaces of the trenches, the through holes and the barrier layer. The lift-off layer, together with the barrier layer covering it, is removed by immersion in a suitable solvent, and copper conductors are subsequently grown in the etched conductor trenches.
Abstract:
A circuit board such as a code disk having a smooth contact surface and a minute pattern is fabricated by depositing an alumite film on an aluminum and selectively filling electrically nonconductive and conductive materials in the cells in the crystals of the alumite film.
Abstract:
The method of manufacturing predetermined microcircuit conductor patterns, which includes forming on the surface plane of a substrate a layer of insulator material, forming a layer of resist on the layer of insulator material, patterning the layer of resist to define a channel pattern, etching the channel pattern with relatively overwide channels, conditioning the channel bases to receive plating material, and thereafter filling the overwide channels with the plating material to a height at least substantially co-planar with the insulator material to define the predetermined conductor patterns, removing the mask and plated material thereon to uncover completely the conductor pattern.
Abstract:
An improved glass panel gas discharge display structure wherein a photolithography step on a plate forming the glass panel is used before metallizing the plate through a mask so that when subsequent dissolution of the mask takes place, the plate is left with embedded metallization essentially coplanar with the surface. The effects of such an embedded electrode structure are that it minimizes attack of the metallization when flow on dielectrics are applied since the sidewalls of the electrodes are protected; it permits application of very thin dielectrics by flow-on, sputtering, plasma spraying, evaporation or other suitable techniques since problems of overcoating around edges are eliminated. It minimizes stresses in the composite structure overlying the substrate support and it minimizes adjacent line interactions when very thin coatings are applied. It also minimizes surface irregularities on panel plates.
Abstract:
A process for producing flush printed circuits with plated through holes comprising etching the circuit paths, flushing the circuit paths with the surface of the material, drilling the holes and producing plating material in the hole area through and subsequent to the use of electroless flash material and then removing the flash from all areas other than the hole portion of the circuit board.
Abstract:
An improved printed capacitor includes a pair of inner and outer, closely spaced, coplanar electrodes. The inner electrode has the general shape of a cross, and the outer electrode surrounds the inner electrode and also has the general shape of a cross. The capacitor has a substantially constant capacitance regardless of the relative position of the inner electrode with respect to the outer electrode.