Method for fabricating printed-circuit boards provided with pads for SMD mounting

摘要

Method for fabricating printed-circuit boards provided with pads for SMD mounting (fitting) in the sequential order of the following process steps, a) a copper-coated (copper-clad) mounting plate is provided with a positive photoresist layer having a layer thickness less than/equal to the height of the pads to be built up for the connection of SMD components, b) the positive photoresist layer is exposed, by means of a first film, with a window mask corresponding to the desired pad arrangement, c) the exposed mounting plate is developed in a developing bath, so that, in the area of the exposed windows, the photoresist layer is removed and free copper areas are exposed there, d) the mounting plate thus developed is exposed by means of a second film, with a mask for the conductor tracks (interconnects), the conductor tracks being designed as opaque areas, e) the mounting plate thus exposed for the second time is electroplated in a tin or tin lead bath, a tin or tin lead layer being built up in the region of the free copper areas for a time sufficient for pads to form as a result which have a height greater than/ equal to the thickness of the photoresist layer, f) the electroplated mounting plate is developed in a developing bath, the tinned (tin-plated) pad areas and the resist layer areas which are covered by the opaque conductor track areas of the second film, remaining behind in the process, g) the mounting plate thus developed is etched, the uncovered... Original abstract incomplete.