| 摘要 |
<p>Wedge base electric lamps are made with current leads which can be machine soldered, the leads consisting of copper-clad wire with length is not >9 mm and having a coating of tin obtd. by electroless plating. The leads on the finished lamp are cleaned; dipped 1.5 hours in a bath (a) at 80-90 degrees C., contg. SnCl2. 2H2O; thiourea; HCl; sodium hypophosphite; a wetting agent; and deionised water. After rinsing, the leads are successively dipped in four baths (b-e), each consisting of glycerine contg. 0.3% ZnCl2 and used as follows:- (b) 30 seconds at 100 degrees C; (c) 20 seconds at 150 degrees C.; (d) 10 seconds at 200 degrees C.; (e) 5 seconds at 240 degrees C. The leads are then rinsed and dried. Machine soldering of the lamp leads is possible even after a storage time of 1 year, due to a pore-free tin coating of 3-4 mu m.</p> |
