Abstract: There are disclosed a solder bump forming method and an apparatus therefor, which achieve a high reliability, and an electronic part, produced by this method and this apparatus, is also disclosed. For each of the step of arraying solder balls, the step of supplying a flux, and the step of mounting the solder balls on a board, it is checked whether or not any solder ball is omitted, and the process is conducted while confirming the condition of the operation, thereby enhancing the reliability and also preventing defective products from being produced.

Abstract: An image displaying method and apparatus for simultaneously displaying an enlargement target of an entire original image and its enlarged image on a display screen by automatically disposing the enlarged image. The image displaying apparatus includes display for displaying an enlarged image of part of the entire original image including characters, patterns, etc. in a relation superposed on the entire original image, input apparatus for pointing to specify the enlargement target in the entire original image, and automatic disposing apparatus for preferentially specifying and computing the values of the area of the enlargement target region, the area of the enlarged image display region and the enlargement ratio so as to maximize one of these values and disposing the enlarged image on the basis of the result of computation.

Abstract: An EP output voltage to be outputted during a period of EP polarity is set so that a welding current becomes equal to or lower than a critical current level, and an EN output voltage to be outputted during a period of EN polarity is set at a level lower than the EP output voltage. This makes it possible to substantially equalize a wire melting rate in the period of EN polarity and that in the period of EP polarity with each other. Even at such a short arc length as causing frequent short circuiting, gas-shielded AC arc welding making use of a consumable wire can be still performed stably so that high wire melting rate, shallow penetration, convex weld reinforcement and the like, which are characteristic features of AC welding, can each be set selectively at a desired level or in a desired shape depending on the application.

Abstract: An improved drill bit for high speed, small diameter drilling of printed circuit boards uses flute/land ratio tapering in combination with the appropriate web thickness and point, cutting or flute angles to obtain high quality, accurately positioned holes. In one embodiment, the web thickness at the tip is 15% of the drill diameter, the flute/land ratio is 2.0, the tip angle is 130.degree., the second cutting angle is 20.degree., the third cutting angle is 30.degree., the flute angle is 32.degree., the relief groove depth is 0.001", body length is 0.256" and the distance between the body end and the flute end is 0.01". Such a bit is used in connection with an air jet cooling/cleaning system and a step feed drilling method wherein the first step is between four-six times drill diameter, the second step is between two-three times the drill diameter, and the third step and subsequent steps are between 1.5-2.5 times the drill diameter.

Abstract: A printed circuit board working machine includes a spindle which holds a cutting tool and is movable to bring the tool into contact with and away from a printed-circuit board to be worked. A device for pressing down the printed-circuit board comprises a support mechanism associated with the spindle of the working machine for relative movement thereto, a plurality of holding sections movably supported by the mechanism and a driving mechanism for the holding sections. The holding sections are formed with holes of different sizes, respectively. When working operation, after the support mechanism causes the holding sections to move away to a position free from interference with the tool, the driving mechanism moves the holding sections to align one of the through holes, corresponding to a size of the tool to be used, with the tool.

Abstract: A pulsed arc welding apparatus includes a short circuit detecting circuit for detecting a time during which a short circuit is being produced by melting a consumable electrode across a consumable electrode and a base metal, a comparison circuit for comparing an integrated value or a mean value of short circuit generating time detected by the short circuit detecting circuit with an optional set value, and a control circuit for controlling either one of the supply time of the pulse current and the base current supply time in accordance with the result of comparison by this comparison circuit, thereby to control the arc length.

Abstract: The disclosure relates to spot-facing for exposing an inner-layer conductor embedded in an insulator of a printed circuit board. The spot-facing removes the entire insulator by a mechanical cutter, except a part thereof, to a position just above the inner-layer conductor. The part of the insulator is smaller in thickness than the insulator removed by the mechanical cutter. Then, the remaining part of the insulator is removed by scanning the part with a laser beam to expose the inner-layer conductor. The laser beam is in a slender shape almost perpendicular to the scanning direction of the laser beam and has an almost uniform energy density along the slender shape. Cutter processing is sufficient to be done before the inner-layer conductor, and there is no fear of damaging the inner-layer conductor. Moreover, laser-beam processing is easy to control thermal influence on the portion to be processed of the circuit board, because the energy density of the laser beam is almost uniform.

Abstract: A grinding method and a grinding machine of reduced grinding resistance, in which letting f [mm] denote the diamond particle size of a diamond grindstone, V [m/min] denote the peripheral speed of the diamond grindstone, and f [m/min] denote the feed speed of a workpiece made of Aluminum nitride ceramic, the peripheral speed of the diamond grindstone and the feed speed of the workpiece are set so as to satisfy V.gtoreq.35 .phi.+2000 and V/f.gtoreq.70 .phi.+800.

Abstract: A consumable electrode gas shielded AC arc welding method and an apparatus to practice the method applies alternating current across a consumable electrode and a base metal. During a first period, the electrode is positive and a current of a first level higher than a specified critical level is furnished. During a second period, the electrode is kept positive and current is reduced to a second level lower than the first level. During a third period, the electrode is kept negative at a third current level. These periods are periodically repeated. If during the frist period, the arc voltage drops below a predetermined voltage, current of a fourth level higher than the first level is furnished until the arc voltage exceeds the predetermined level.

Abstract: A pressure foot (7) of a printed circuit board drilling apparatus is supported on a spindle (2) of the printed circuit board drilling apparatus slidably in the axial direction, and includes a pressing face (13) which presses a printed circuit board (5) at the time of drilling operation, a discharge port (11) formed in a side wall (8) so as to discharge chips produced by drilling operation, the discharge port (11) being connected to a suction device, and a compressed air supply conduit (20A) formed in a side wall so as to eject the compressed air toward a drill bit (4) of the printed circuit board drilling apparatus. A cooling fluid supply device (21) is connected to the compressed air supply conduit (20A). In place of the compressed air supply conduit (20A), a fluid supply conduit (14) for ejecting a cooling fluid toward the drill bit (4) of the printed circuit board drilling apparatus may be formed.

Abstract: The present invention relates to a printed wiring board and a method of manufacturing a printed wiring board. A first printed wiring board and a second printed wiring board, each including an insulating layer and a copper foil layer, are superposed on one another with a middle insulating layer therebetween with blind holes formed in the insulating layers of the boards to oppose one another, through-holes are formed and provided with conductive plating to electrically connect the copper foil layers with each other, and reflow pads are formed by etching in the copper foil layers to seal the blind holes. The blind holes are formed through the insulating layers and reach the copper foil layers. Plated layers are plated on the surfaces of the printed wiring boards on the sides thereof where the blind holes are formed to electrically connect the blind holes and the copper foil layers, respectively.

Abstract: A main CPU unit and a plurality of CNC units provided on a one-to-one correspondence with machine tools, and the main CPU unit is connected with an external storage device and an input device. To modify the mode of machine tool control or machining data of work, a new system program is down-loaded through the RAM of the main CPU unit into the CPU for the CNC unit, and according to this new system program, the part program including machining data normally stored in the CPU for the CNC unit.

Abstract: In a consumable electrode gas shielded arc welding system, alternating current power is applied across the electrode and the base metal. The period during which the electrode is kept negative is varied to correspond to the electrode feeding rate. In addition, the levels of the output power during the negative and positive periods are individually set.

Abstract: A printed circuit board processing apparatus includes: a plurality of printed circuit board processing machines (A) arranged side by side, in each of which a printed circuit board (W) placed on a table (4) and a tool held by a single spindle (13) are caused to make a relative movement in the X-, Y- and Z-directions of the machine to process the printed circuit board (W); tipping devices (B) respectively mounted on the tables (4) in such a manner as to be swingable and adapted to perform the delivery of printed circuit boards (W); conveying devices (C) arranged along the beds (1) of the printed circuit board processing machines (A) and each equipped with a feeding path (C1) and a discharging path (C2) which are adapted to convey printed circuit boards (W) in an inclined posture; loading/unloading devices (D) arranged at a delivery position on the printed-circuit-board-processing-machine side of the feeding and discharging paths of the conveying devices (C) and adapted to effect the delivery of printed circuit

Abstract: A punching apparatus used for high speed punching of holes in a workpiece, such as a ceramic green sheet, for use as a printed-circuit board. Upper and lower die blocks, stationary relative to each other, are provided, with punch pins fixed in two dimensions by multiple guides. A fluid passage is provided within the lower die block for providing gaseous lubrication and cleaning of the punch pin while in operation.

Abstract: A tool holding device for use in a printed circuit board processing machine is provided with a record which is capable of storing data concerning the states of tools held on the tool holding device and data concerning processing conditions and which enables reading and updating of the recorded content through a communication with an external control device. Necessity for renewal of data registered in the NC device, which has to be executed in the known apparatus each time the tool holding device is exchanged, is eliminated thereby improving the rate of operation of the printed circuit board processing machine. In addition, the present invention enables an easy automatic replacement of tools when the lives of the tools are expired.

Abstract: Ratios between a distance between an upper wire guide and the upper surface of a workpiece to be machined, a thickness of the workpiece and a distance between a lower wire guide and the lower surface of the workpiece are given to the inlet and outlet positions of a wire electrode at the upper and lower surfaces of the workpiece which have been interpolated so as to directly obtain displacement positions of the upper and lower wire guides, along which the upper and lower wire guides are moved successively, thereby obtaining an articles which is accurately machined with a relatively simple machining procedure.

Abstract: The present invention relates to a printed circuit board presser device in a drilling machine. The board presser device is arranged such that it includes an axially movable upper-plate presser device which is provided on the outer side of a contact surface of the board presser device with a printed circuit board so that a top end surface of the upper-plate presser device extends to the side of a table beyond the contact surface; and an urging device for pushing the upper-plate presser device against the table by a force larger than an attraction force generated from the board presser device. With such construction, an upper plate is suppressed from floating during drilling the printed circuit board, and a distance of useless transfer movement of a drill decreased, to thereby improve an efficiency of a drilling operation.

Abstract: In correspondence with the graphic data having a spatial extent, there is the address data table configured of arrays, the dimension of which are not smaller in number than the dimensions of the extent of the graphic data. Coordinate transformation is performed between the graphic data and the address data table, whereby any desired point on each figure can be brought into correspondence with one array number of the address data table. Those memory addresses of a graphic data table at which the individual graphic data items are sorted, are subsequently stored in the address data table. In case of searching for graphic data located at any desired position, the corresponding array number of the address data table is obtained on the basis of the position, whereupon the desired figure can be searched for through that memory address to the graphic data which is stored.

Abstract: A method of and apparatus for effecting a machining operation, e.g. drilling, on a multi-layered printed circuit board utilizing a machining apparatus having a spindle for driving a tool. The spindle is movable in the axial direction of the tool and a pressure foot for pressing the printed circuit board during the machining is mounted on the spindle for relative movement with respect thereto. The method includes the steps of determining the position of the end of a tool with respect to the end of a pressure foot in the state before the pressure foot contacts the printed circuit board, setting the amount of relative movement between the pressure foot and the tool necessary for effecting the desired machining, on the basis of the position of the end of the tool and a predetermined set value of the machining depth; and effecting the machining on the printed circuit board by controlling the feed of the tool in conformity with the amount of relative movement.