| 摘要 |
The invention relates to a drilling covering (2), made from, or essentially made from a metal foil (8), for the mechanical drilling of microfine holes, in particular, in the production of circuit boards, which is characterised in that the metal foil comprises, on at least one outer facing surface, an essentially non-directional microtopography (10), with a surface roughness (16) of between 1 and 5 mu m, preferably between 2 and 4 mu m and a target value of 3 mu m. Said microtopography permits an off-centre deviation of drilling by, at most, an amount corresponding to the order of magnitude of the surface roughness. The above may be produced by means of rolling, stamping, sandblasting, microetching, electropolishing or similar. Where desired the metal foil (8) can be laminated on a film (20) made from softer material.
|
