Method for etched and/or galvanic production of ring zones in small diameter holes

A method for production of electrically conducting or insulating ring zones on the wall of a small diameter continuous hole in a workpiece having a thickness in the range of 0.1 to 3 millimeters comprising the steps of:

• applying a base metallization to the surface of the workpiece including said walls of said holes;
• filling said holes with a positive photoresist and drying said photoresist such that said photoresist withdraws from the hole openings on the workpiece surfaces toward the inside of the hole forming a plug therein;
• subjecting both sides of said workpiece to a means for making said photoresist partially soluble for a resist developer;
• dissolving said partially soluble photoresist away from freeing portions of said wall of said hole of resist up to a selected resist ring thickness;
• and
• generating a ring zone in the interior of said hole by one of the following series of steps,
• galvanically depositing at least one metal layer on said portions of said wall of said hole which have been freed of said photoresist, dissolving said photoresist plug for exposing said base metallization, and selectively etching away said exposed base metallization for generating an insulating ring zone in said hole, and
• removing said base metallization by etching from said portions of said wall of said hole which have been freed of said photoresist for generating a conducting ring zone in said hole.