Abstract: A wet etching process for forming vias or pre-designed patterns in organic polymeric layers such as fully or substantially fully cured polyimide layers which are used as circuit carriers in laminated integrated circuits by placing said organic polymeric layer in an etching bath containing two electrodes immersed in an etching solution and applying an alternating current having a voltage of about 0.3 to 1.0 volt and a frequency of about 60 Hz, or a direct current of about 0.8 to 20 volt to the electrodes. The etching solution contains acid or metallic hydroxide and, optionally, 3-15 wt % N-methyl-2-pyrrolidone. The present invention provides a fast and safe etching technique without the need to use the toxic and explosive etching chemicals such as hydrazine hydrate or ethylene diamine.