Internal coating, internal alloying, internal filling of through-holes using a laser

摘要

The method represents a universal method with which a laser can be used to coat or fill through-holes in a workpiece with another material. Using the method, the procedure adopted can be in particular such that (Fig. 1) the laser (1) produces the hole to be coated in the workpiece (2) in one operation and, after the undercut coating material (4, 5) is reached, it is expelled and becomes deposited (3) on the inner wall of the tool. Advantages of the method are that: 1. virtually any desired combinations of workpiece and coating material are possible, 2. only small thermal stresses occur and 3. high repetition rates and an easy-to-control processing pattern are possible. The following ranges of application are suitable: through-contacting microcircuits and local processing of for example films for increasing the mechanical, chemical or biological resistance.