Abstract: A method for masking through-holes during the manufacture of a printed circuit board comprises providing a substrate having a plurality of through-holes. A removable masking seal comprised of a soluble material, a light-setting material or a thermo-setting material is formed on the surface of the substrate to cover at least one of the through-holes. At least one of the through-holes that is not covered with the masking seal is filled with a filler material by a conventional silk screen process. The masking seal is then removed, either by dissolving the masking seal in the case of the soluble material, or in the case of the light-setting or thermo-setting material, the masking seal is set by applying light or heat to reduce adhesion between the masking seal and the substrate, and then the set masking seal is peeled off to expose the through-hole.

Abstract: A hole masking apparatus for use in the manufacture of a printed wiring board is disclosed. The apparatus comprises first and second positioning sections provided on a conveying path of a base material at a distance apart for stopping the positioning of the base material having a plurality of through holes at respective given position; a masking device provided to respective positioning sections and having a head to paste a seal while supplying and for pasting the seal on through holes by moving the head in such a manner that the head is positioned on through holes which do not require a plugging up thereof; and a reversing section arranged between the first and the second positioning sections and for reversing face and back of the base material on the conveying path thereof.

Abstract: An etching method of forming circuit patterns on a printed circuit board is disclosed. The etching method comprises step of supplying etching solvent with discharge pressure of substantially 5.about.10 kg/cm.sup.2 and discharge particle diameter of 100.about.200 .mu.m.

Abstract: An etching apparatus for forming circuit patterns on a printed circuit board comprises a conveyor for conveying printed circuit boards, a solvent pump for pumping etching solution, nozzles for spraying etching liquid or water on the printed circuit board, and a rinsing device for rinsing the surface of the printed circuit board. The discharge pressure of the pump for the etching solvent is preferably in the range 5.about.10 kg/cm.sup.2 and the distance between the nozzles and the printed circuit board is 50.about.200 mm.

Abstract: Disclosed are a method of filler taping a screen frame and a method of filling a screen frame. The screen frame is held in such a manner as to be indexable 90 degrees, a tape is attached simultaneously on opposing two sides of the screen frame through linear motion. At the same time, a filling liquid is applied simultaneously on opposing two sides of the screen frame on the rear surface thereof. Subsequently, the screen is rotated 90 degrees, and taping and filling are similarly effected with respect to the remaining two sides.

Abstract: A planar surface of an article is ground smooth by a two-stage grinding head having an upstream-stage grinding brush and a downstream-stage grinding stone. The article is advanced past the grinding head while the grinding head is eccentrically driven so that the grinding brush coarsely grinds the planar surface and forms therein spiral brush traces and the grinding stone finely grinds the coarsely ground planar surface to smoothen the brush traces.

Abstract: An apparatus for surface grinding a planar surface of an article comprises a two-stage grinding head having an upstream-stage grinding brush and a downstream-stage grinding stone. The article is advanced past the grinding head while the grinding head is eccentrically driven so that the grinding brush coarsely grinds the planar surface and forms therein spiral brush traces and the grinding stone finely grinds the coarsely ground planar surface to smoothen the brush traces.

Abstract: A method of chamfering the outer peripheral edges of plate members comprises stacking the plate members in face-to-face vertically aligned relation so that for each two adjacent plate members the upper outer peripheral edge of the lower plate member opposes the lower outer peripheral edge of the upper plate member, detecting the boundary between two adjacent plate members in the stack, positioning a rotary chamfering tool in response to detection of the boundary, and moving the rotary chamfering tool relative to the outer peripheral edges of the two adjacent plate members to simultaneously chamfer the upper edge of the lower plate member and the lower edge of the upper plate member. The detecting, positioning and chamfering steps are repeated for each two adjacent plate members in the stack to thereby chamfer both the upper and lower edges of the stacked plate members.

Abstract: Disclosed are an apparatus for filler taping a screen frame and an apparatus for applying a filling liquid to a screen frame. The screen frame is held in such a manner as to be indexable 90 degrees, a tape is attached simultaneously on opposing two sides of the screen frame through linear motion. At the same time, a filling liquid is applied simultaneously on opposing two sides of the screen frame on the rear surface thereof. Subsequently, the screen is rotated 90 degrees, and taping and filling are similarly effected with respect to the remaining two sides.