Printed circuit board micro hole processing method

A PC board micro hole processing method adapted to make micro holes on an PC board, said PC board comprising a substrate of glass fiber resin compound and at least one metal covering layer covered on at least one top and bottom surfaces of said substrate, the method comprising the steps of:

• a) removing the metal covering layer, where a chemical etching procedure is employed to remove metal material from predetermined areas of said substrate, enabling the predetermined areas of said substrate to be exposed to the outside;
• b) applying the PC board to a low-tension electric field of predetermined strength, and feeding a gas into the low-tension electric field for enabling the gas to be decomposed into electrons, ions, or radicals to cause a chemical reaction with the resin of said substrate at said predetermined areas, so that the chemical reaction lowers the molecules of the resin material and causes the resin material to be released in the form of vapor, and at the same time vaporized molecules thus produced are drawn away, causing the resin material to be etched layer by layer at said predetermined areas;
• and
• c) chemically etching, where a chemical solution is applied to said substrate to remove the residual fibers left after the process of applying the PC board to the electric field, finishing the desired micro holes.