Abstract: This invention is directed to composite coating for maintaining low moisture levels at the surface of solid substrates. One embodiment of the invention comprises a coating having a desiccant layer between layers of the same or different elastomeric polymers. Another embodiment comprises a layer of elastomeric polymer covered with a layer of an elastomeric polymer/desiccant mixture. The composite coating may be applied to integrated circuits to prevent corrosion thereof.

Abstract: A method of boring holes in a circuit board assembly of the type having a first layer of material which is primarily reflective of light of a first light wavelength and having a second layer of material, overlying the first layer of material, which is primarily absorptive of light of the first light wavelength, comprising: tuning the frequency of a laser cutting device to the first light wavelength; directing a laser beam from the tuned laser cutting device onto the second layer of material in a region where a hole is to be provided; and terminating application of the laser beam after a hole has been bored through the second layer of material.

Abstract: A method for making printed circuit boards wherein the resistance of catalyzed nonconductive surfaces to solutions used in the processing stages, e.g., KOH used to remove an etch resist covering through-holes and the desired circuit lines, is enhanced by treating the catalyzed surface with an accelerator to activate the catalyst, treating the accelerated surface with a reducing agent, followed by baking.

Abstract: Circuit boards having excellent electrical and mechanical properties are obtained when special mixtures of polyarylene sulfides and polycarbonates, polyaryl ethers, polyamides, polyesters or rubber elastomers are used as base plates for the wet-chemical deposition of the circuits and the boards are treated with an oxidizing agent before activation.

Abstract: A process for manufacturing printed circuits provided with through holes, which comprises a cleaning pretreatment including a possible treatment by an organic solvent, a treatment in an alcaline solution of permanganate and a treatment for permanganate reduction, and a subsequent metallization treatment including a treatment for conditioning the walls of the through holes, a treatment for mordanting the copper surfaces, a precatalysis treatment, a catalysis treatment and a metallization treatment by a chemical copper both, wherein three treatments, namely reducing the permanganate, conditioning the walls of the through holes and mordanting the copper surfaces, are performed in a single step. The treatment for conditioning the walls of the through holes is performed by means of non-surfactant, water soluble polymers belonging to the group of the cationic polyelectrolytes.

Abstract: Metallic surfaces to be provided with a tin-lead coating from an immersion tin-lead bath, and particularly copper surfaces (e.g., through-holes, pads) of a printed circuit board having other metallic surfaces thereon covered by a hydrophobic solder mask, are prepared for receipt of immersion tin-lead coating by, e.g., contact thereof with a strongly acidic aqueous pre-dip solution containing at least one surface active agent functional to reduce the surface tension of the pre-dip solution and/or to provide the solution with improved affinity for the metallic surface.

Abstract: The method and apparatus of the present invention permits the automated deposition of heated solder onto a plurality of conductive pads which are disposed in one or more linear arrays on a circuit board or other planar member. A robotically controlled arm is utilized to mount a solder nozzle and selectively manipulate the solder nozzle over the circuit board. The solder nozzle is first manipulated to a selected point offset in a known direction and distance from a first conductive pad by means of a data set which specifies the centroid and footprint for a selected group of conductive pads. After feeding solder into the solder nozzle, aligning the solder nozzle at a desired angle parallel to a linear array of conductive pads and lowering the solder nozzle until a solder droplet contacts the circuit board, the solder nozzle is manipulated at a substantially constant velocity toward the first conductive pad and thereafter along a selected line which tracks the linear array of conductive pads.

Abstract: A method of manufacturing a printed circuit board for use in an electronic circuit is disclosed. The method comprises steps of forming a printed circuit on an insulating base board, of forming a circuit portion to be connected to the printed circuit by adhering a conductive ink on the base board, and of adhering the conductive ink through an uneven surface formed on a terminal portion to be connected to the printed circuit.

Abstract: Disclosed herein is a method of forming strip-shaped electrodes over an end surface of a plate-shaped electronic component and two major surfaces which are in series with the end surface. A slit plate, which is provided with through slits having width corresponding to the width of electrodes to be formed, is located above an electrode paste bath while an electronic component is arranged above the slit plate so that its end surface extends across the through slits. Before or after this step, the electrodes paste is made to swell to a constant level beyond the upper surface of the slit plate, thereby applying the electrode paste to the end surface of the electronic component and the two major surfaces which are in series with the end surface in the form of strips.

Abstract: An activation solution for the activating of electrically nonconductive plastic surfaces of the purpose of a subsequent chemical metallization is prepared from an acid, a palladium(II) salt and a tin(II) salt, the palladium being present predominately in complexly dissolved form. The solution is prepared at room temperature, the molar ratio of the palladium employed and of the tin employed being about 1:1 to 1:2. The solution is mature and catalytically effective after about 10 minutes. There are no further stabilizing agents, auxiliary materials or the like present.

Abstract: Pinhole and blister formation during autodeposition coating of active metal objects, particularly galvanized steel, other zinciferous surfaces, and even ordinary steel that has been abraded, scratched, or otherwise strained, can be greatly reduced by exposing the active metal surfaces to a solution containing cystine before using a autodeposition process itself, or by adding cystine to an otherwise conventional autodeposition composition.

Abstract: A method and apparatus are disclosed for enabling automated printing of through holes extending between top and bottom surfaces of a ceramic substrate or the like. The perimeter of the substrate is placed on a support that locates the bottom surface of the substrate spaced from a member that interacts with the interior portion of the substrate. The interacting member has holes that correspond to the through holes in the substrate, and it is moved generally perpendicular to the substrate to a position where it is in juxtaposition with the bottom surface of the substrate and its holes are in registration with the holes in the substrate. Conductive material is applied to the top surface of the substrate and a vacuum is applied to the holes in the interacting member to pull the conductive material through the through holes in the substrate. The vacuum is then discontinued and the interacting member is moved back to a position where it is spaced from the bottom surface of the substrate.

Abstract: To electrolessly depositing nickel on tungsten surfaces or molybdenum surfaces which have been deposited on surfaces of ceramic bodies, the ceramic bodies are nucleated, preferably after thorough cleaning, for example with aqueous hydrofluoric acid, by immersion in an aqueous solution containing palladium ions and then introduced into an electroless nickel-plating bath. Before the nickel-plating, the nucleated ceramic bodies are treated in a bath containing a complexing agent for palladium ions, for example in an aqueous cyanide solution.

Abstract: An electroless metal plating process, particularly for use in plating through-holes in printed circuit substrates, and more particularly for additively depositing copper metal on through-hole surfaces, in which the substrate is at least intermittently subjected to vibrating motion in contact with the electroless depositing bath, and an electroless metal depositing apparatus for carrying out the process.

Abstract: A method of fabricating a printed wiring substrate board to have integral contacts over the thickness of a defined connector edge in order to allow for perpendicular mating to exposed conductors on the surface of a second substrate.

Abstract: The process comprises, after deposition of a layer of raw ink on a support having a high thermal dissipation, of the aluminium nitride type, effecting a preliminary drying of this ink at a temperature on the order of 100.degree. C. to 150.degree. C., then a firing comprising:(a) a temperature rise including a polymer resin eliminating stage,(b) a sintering plateau at a temperature on the order of 600.degree. C. to 1000.degree. C., and(c) a timed cooling,wherein the atmosphere of the polymer resin eliminating stage has an oxygen content of between 100 ppm and 5000 ppm, while the oxygen contents of the high temperature sintering atmosphere and of the cooling atmosphere must be lower than about 10 ppm.

Abstract: A conductive metal layer is formed on a substrate having a softening point above about 200.degree. C. by depositing copper and nickel particles having a substantially continuous oxide coating thereon on the substrate, and heating and pressing the metal particles at a temperature of at least 200.degree. C. Unlike similar methods wherein oxide coated metal particles are used, no developing agent is required to render the metal layer conductive. The coated substrates are useful for a variety of uses such as EMI shielding and printed circuit boards.

Abstract: A pair of solder coating rolls are disposed horizontally adjacent one another for rotation about parallel horizontal axes, and are spaced apart to define a narrow vertically-oriented nip therebetween for accommodating a lead frame therein. Lower parts of the rolls contact a solder bath, and counter rotation of the rolls carries the solder upwardly on the periphery of the rolls to create a small pool of solder at the upper end of the nip. The lead frame is driven vertically upwardly through the nip, which nip has a minimal dimension greater than the lead frame thickness. The lead frame is driven vertically upwardly at a linear speed which is different from, and preferably slower than, the peripheral speed fo the solder coating rolls. This enables preheating of the surface of the lead frame due to its longer exposure to and contact with the hot solder which coats the periphery of the rolls, thereby improving the wetability of the lead frame surface.

Abstract: The disclosed invention relates to a method of manufacturing hybrid circuit boards which uses the step of electrodeposition of a photoresist composition onto said boards. This step represents improvements in the prior art use of dry film or other types of photoresists which did not conform to all three dimensional surfaces and which were not aqueous developable.

Abstract: An adhesive for electroless plating is formed by dispersing particular heat-resistant granules easily soluble in an oxidizing agent into a particular heat-resistant resin sparingly soluble in the oxidizing agent through a curing treatment. A printed circuit board is manufactured by using such an adhesive.