摘要 |
<p>In the production of printed circuit boards it is required that organic protective coatings adhere tightly on the copper surfaces. Accordingly, matt layers of copper are to be preferred over lustrous coatings. The bath in accordance with the invention serves to deposit matt layers of copper and has the additional advantageous property that the layers may also be deposited with sufficient coating thickness in very narrow bore holes at average cathode current density. For this purpose the bath contains at least one polyglycerin compound selected from the group comprising poly(1,2,3-propantriol), poly(2,3-epoxy-1-propanol) and derivatives thereof.</p> |