TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Component: The sensitizing liquid comprises 3-25 g/l zinc chloride dihydrate and 3-40 ml/l of 37% hydrochloric acid water solution. The activating liquid comprises 0.1-0.6 g/l palladium chloride and 3-10 ml/l of 37% hydrochloric acid water solution. The chemical plating liquid comprises 15-25 g/l nickel sulfate hexahydrate, 25-40 g/l sodium hypophosphite, 40-60 g/l sodium pyrophosphate, and 10-20 ml of 28% ammonia water, when transitional layer is made of nickel-phosphorus layer; or 25-30 g/l nickel chloride hexahydrate, 0.5-3 g/l potassium borohydride, and 55-70 ml/l ethanediamine, when transitional layer is made of nickel-boron alloy; or 5-10 g/l copper sulfate pentahydrate, 10-25 ml/l of 37% formaldehyde water solution, 10-20 g/l potassium sodium tartrate, 10-15 g/l sodium hydroxide, 20-25 g/l EDTA di-sodium salt, 5 -10 ml/l potassium ferrocyanide, and 10-20 ml/l alpha , alpha '-bipyridyl, when transitional layer is made of copper metal; or 25-40 g/l nickel sulfate heptahydrate, 5-10 g/l copper sulfate pentahydrate, 20-40 g/l sodium hypophosphite, 35-40 g/l sodium citrate, 5-10 g/l succinic acid, 40-50 g/l ammonium chloride, and 5-10 g/l sodium acetate trihydrate, when transitional layer is made of nickel-copper-phosphorus alloy; or 25-35 g/l nickel chloride hexahydrate, 0.5-2 g/l copper sulfate pentahydrate, 0.5-33 g/l sodium borohydride, 35-45 g/l sodium hydroxide, 0.04-0.06 g/l lead chloride, 30-40 g/l sodium citrate solution, and 5-10 g/l succinic acid, when transitional layer is made of nickel-copper-boron alloy.    TECHNOLOGY FOCUS - METALLURGY - Preferred Component: The sensitizing step is performed at 20-25 degrees C for 5-10 minutes. The activating step is performed at 20-25 degrees C for 3-5 minutes. The drying step is performed at 100-120 degrees C in electric oven. The metal layer is made of aluminum or copper at thickness of 0.5-10 mu m. The annealing step is performed at 400-600 degrees C for 10-60 minutes under hydrogen atmosphere.