Process principle

The copper covered base material used in traditional panel-plating processes is initially coated in a continuous chemical tinning line with a homogenous, non-etchable tin-resist (Unicron ER®).

The tin-resist is removed by the laser beam in the areas to be etched, whereby a large part of the copper layer is ablated at the same time. The very thin tin-resist coating and the strongly thinned copper layer improve the etching process. Etching times and under-etching can thus be effectively minimised.

The laser source used is a frequency-tripled Nd:YAG-laser with a wavelength of 355 nm. Because of its excellent focussing ability, extremely narrow channels can be structured in the tin-resist.

In an alkaline etching bath, insulation channels are created around the conductor lines in the area of the ablated track. Line widths and spaces <50 μm can thus be realised.

The tin needs only to be stripped prior to the further processing of the circuit board. Tin-resist structuring is superbly suited for the production of ultra-fine line areas on HDI multilayers. The highest registration requirements are met by online scaling.


Read further under Advantages laser structuring