Abstract:
A method for wave soldering a circuit having two or more faces comprising the steps of: (i) passing at least one initial gas mixture comprising at least one of an inert gas, a reducing gas and an oxidizing gas into at least one apparatus for forming excited or unstable gas species; (ii) converting the at least one initial gas mixture into at least one primary gas mixture comprising excited or unstable gas species and substantially free of electrically charged species; (iii) treating each of the two or more faces of the circuit with the at least one primary gas mixture at a pressure close to atmospheric pressure; and (iv) contacting the two or more faces of the circuit with at least one wave of a liquid soldering alloy.
Abstract:
A voltage is applied between a first cleaning electrode that in contact with an electrode on a workpiece such as a printed circuit board or a chip, and a second cleaning electrode located in the vicinity of the electrode on the workpiece, from a voltage application circuit so as to produce an electric discharge on the electrode on the workpiece, whereby contamination sticking to the electrode on the workpiece is locally removed by heat generated from the electric discharge.
Abstract:
There are herein disclosed a method for preparing a modified resin which comprises thermal/reaction by the use of a norbornenyl group-containing compound typified by norbornenecarboguanamine or its derivative, a method for preparing an epoxy-modified resin which comprises the step of reacting the above-mentioned modified resin and an epoxide, a flame-retarding method, a thermal stabilization method, a compatibilizing method and a surface modification method which comprise utilizing the modified resin, as well as a coating resin composition and an adhesive resin composition containing the modified resin. According to the, preparation methods of the present invention, the deterioration of a material scarcely occurs, and a functional group which is excellent in flame retardancy, thermal stability, compatibility and the like can be introduced to the resins. By the utilization of these techniques, there can be obtained a flame-retardant material having a good char formability, a thermally stable material whose molded articles can inhibit heat deterioration, a material excellent in miscibility between different kinds of resins, a surface-modified material which is excellent in adhesion and coating properties and the like.
Abstract:
A method is available for wave-soldering component groups, especially printed circuit boards with shielding from the environment, in which lead-free or at least low-lead solders, especially tin solders, with a melting point of more than 210.degree. C., are used. Since in wave soldering the solder bath temperature must usually be set considerably higher than the melting point of the solder, problems with overheating the components are encountered with higher-melting lead-free or low-lead solders. This problem is solved in accordance with the invention by setting a solder bath temperature which is only a few degrees Celsius above the melting point of the solder material, and performing the wave-soldering by the action of a plasma of a process gas atmosphere at low pressure.
Abstract:
In one aspect, a device for attaching a component to a circuit board is provided, comprising a circuit board held in a holder and a contact heater that heats the component on the circuit board by contact and by conducting heat through the component. In a further aspect, the contact heater is in a wand which is manually moved onto the component. In another aspect, the invention provides a method for attaching a component to a circuit board, comprising the steps of gripping the component with a contact heater; placing the component on the circuit board; and heating the component on the circuit board by contact, wherein heat conducted through the component melts solder under the component and attaches the component to the circuit board.
Abstract:
A method of forming via holes in an organic insulation film or cutting the film includes the steps of exposing predetermined parts of the film to a laser beam to raise a temperature of the exposed parts of the film until the exposed parts are transformed or decomposed and subjecting the film to an ultra sonic wave so that the transformed or decomposed parts are dispersed.
Abstract:
A printed circuit board ("PCB") is moved on a conveyor towards an ultrasonic spray head ("head") that is mounted below the PCB on a guide rail. The guide rail and the direction of motion of the PCB define an acute angle. When the PCB reaches a predetermined position, the head begins a motion across the PCB, spraying a rectangular swatch of soldering flux. The velocity of the head is controlled such that the swatch of flux is substantially perpendicular to the direction of motion of the PCB. After spraying, the head deactivates and reciprocates back across the PCB such that no flux is sprayed. The cycle repeats after a predetermined delay whereby adjacent swatches of flux do not substantially overlap.
Abstract:
A pallet holds one or more circuit boards for processing. A pallet opening for receiving the circuit board has grooves at one side to retain an edge of the circuit board and rotary clips at the other side to receive and hold the opposite edge of the board. Each clip is a disk which is mounted for rotation about a central axis and is constrained to two angular positions by a detent. A notch in the disk receives the circuit board when in one position and clamps the board against a seat when in the other position. The notch is deep enough to allow the board to be shifted laterally for alignment with test apparatus.
Abstract:
A reflow apparatus includes a reflow furnace. A transfer device holds and transfers printed circuit boards with to-be-reflowed electronic components thereon from an inlet to an outlet of the furnace within the furnace. A plurality of adjusting/circulating sections separate an ambient gas for heating the printed circuit boards into predetermined temperature regions in the furnace in which the ambient gas is circulated in a heated state. A feed port is formed in the furnace to feed the ambient gas into the furnace under pressure. Residence parts each provided between adjacent adjusting/circulating sections regulate the amount of the ambient gas when the ambient gas, after having been sent to and heated in the adjusting/circulating section adjacent to the feed port, is circulated and sequentially moved to the adjusting/circulating sections at the inlet or the outlet and finally flows out through the inlet or outlet into atmosphere. Suction ports are open to the furnace to suck the ambient gas from the inside of the furnace. A flux removing unit is separate from the furnace and removes components of a flux from the ambient gas sucked through the suction ports from the inside of the furnace.
Abstract:
A pallet for holding a printed circuit board comprises first and second parallel rails and third and fourth parallel rails. The third and fourth rails each have first and second ends and form an angle of between about 30.degree. and 60.degree. with the first and second rails. The first and second ends of the third and fourth rails are connected to one of the first and second rails. The pallet further comprises an attachment for securing the printed circuit board to the third and fourth rails. The angled pallet has advantages over conventional pallets as shorts and shadowing are reduced.