Imidazole is a liquid chemical to protect copper surfaces found on printed circuit board from oxidization. Through immersion of the board into the liquid, an organometallic layer, bound through absorption, is formed on the copper. The thickness of the layer is in the range of appr. 2 nm - 0.5 µm. This pcb surface is available on the market under the name OSP (Organic Solderability Protection/Preservation). OSP is not suitable or, in the best case when processed under in a N? atmosphere, marginally suitable for multiple soldering processes.