| 摘要 |
PCT No. PCT/GB89/01536 Sec. 371 Date Oct. 22, 1990 Sec. 102(e) Date Oct. 22, 1990 PCT Filed Dec. 22, 1989 PCT Pub. No. WO90/07858 PCT Pub. Date Jul. 12, 1990.Printed circuits are produced by screen printing or the like to deposit conductors, resistors, capacitors and insulators. Crossover connections are made by covering the conducting portions to be crossed with an insulating material that serves as a base for a printed crossing conductor. The equivalent of multilayer boards can be achieved by printing repeated layers of conductors, components and insulators on the same side of the board, or by printing on two sides of a board. Interconnection between adjacent layers can be made as a part of the printing process. A method of making a printed circuit board comprises applying a first and second coating in a desired pattern to a substrate, the substrate (12) being disposed in a different relationship to coating apparatus used in applying a second coating from the relationship in which it is disposed in applying the first coating. Preferably a number of identical boards are printed on a substrate (12) from which they are subsequently separated. The individual boards are positioned such that the same pattern may be applied when the substrate (12) is presented to coating means in any of a number of orientations each separated from the next by a fixed angle of rotation about an axis (A) at right angles to the substrate (12), the first coating being applied in one such orientation and the second after the screen and substrate respectively have been rotated in opposite direction, (S,B) each through 90 DEG . |
