| 摘要 |
PURPOSE: A plating method using a tin-zinc alloy plating solution is provided to secure an even plating layer on a low current area by adding ethylenediaminetetraacetic acid tetrasodium salt and glycerin to the tin-zinc alloy plating solution. CONSTITUTION: A plating method using a tin-zinc alloy plating solution comprises the following steps. Fat on the surface of a metal material to be plated is removed. The fat-removed metal material is washed in a warm water bath at about 60°C. The metal material, which is washed with warm water, is treated with an acid by using a hydrochloric acid of 20%. The metal material is activated after the acid treatment. The activated metal material is plated by using the tin-zinc alloy plating solution. The metal material is activated after the plating work. The surface of the activated metal material is coated with a rust prevention coat. The metal material which is complete in rust prevention treatment is washed in a warm water bath at 50-70°C. [Reference numerals] (A1) Deep cleaning; (A2,B2,C2,D2,E2,F2,G2,H2,I2,J1,K2,L2,M2,N1,O2,P2,Q2,R2) Work condition; (A3,B3,C3,D3,E3,F3,G3,H3,I3,J2,K3,L3,M3,N2,O3,P3,Q3,R3) Temperature; (A4,B4,C4,D4,F4,H4,I4,J3,L4,N3) Work time; (B1) Elctro cleaning; (B5,J6) Current; (C1) First heating rinse; (C5,E5,G5,K5,L7,M5,P5) Three seconds; (C6,E6,G6,K6,P6) Three step rinse; (D1) Acid pickling (hydrochloric acid); (D5) 2±1 minutes; (D6,F6,H6,L8,N5,R6) Concentration; (E1,G1,K1,M1,P1) Rinse; (E4,G4,I6,K4,L6,M4,P4,Q4) Dipping time; (F1) Chemical polishing; (F5) 30-60 seconds; (H1) Neutralization treatment (electrolytic degreasing alkali neutralization); (H5) 15±5 seconds; (I1) First activation; (I5,L5) 10±5 seconds; (J4) 60 seconds; (J5) Voltage; (L1) Second activation; (L9) Citric acid 50g/L; (M6) One step rinse; (N4) 60±30 seconds; (O1) Leaving at a room temperature; (O4) Room temperature; (O5) Leaving time; (O6) 30±10 seconds; (O7) Significant respects; (Q1) Second heating rinse; (Q5) 10±5 minutes; (R1) Drying; (R4) Drying time; (R5) 20±5 minutes; (S100) Provide time for forming a chromate film |
