METHOD FOR PRODUCING VIA CONTACTED PCBS WITH VERY SMALL OR NO SOLDER EYES.

摘要

The invention relates to a method for producing printed circuit boards with through-plated holes and very small solder lands, or no solder lands, in accordance with the Tenting method. In the case of the Tenting method there is a risk of the photographic film (5) tearing off and etching medium penetrating into the through-plated holes (3) and damaging the copper layer (2) located on the hole walls. In order to avoid this disadvantage, the invention provides that the printed circuit board is provided with an etching-resistant protective film (4) before being coated with photographic film (5). Once the conductor pattern has been developed, the etching-resistant protective film (4) is removed from the free copper surface (2) by briefly treating in acid, and the conductor pattern structure is then produced using alkaline etching medium. Once the photographic film (5) has been stripped off, the protective film (4) is removed from the walls of the through-plated holes (3) by means of acid. IMAGE