| 摘要 |
1446568 Soldering INTERNATIONAL BUSINESS MACHINES CORP 19 Nov 1973 [11 Dec 1972] 53563/73 Heading B3R [Also in Division H4] To remove excess solder from a solder coated substrate to provide a desired thickness of solder on the substrate, the substrate is submerged in a bath of glycerol at a temperature above the melting point of the solder, a cavitation area is produced in the glycerol by ultrasonic vibration and the substrate is moved through the cavitation area. A tank 11 having heating elements 13 in its walls contains glycerol 12, preferably 1, 2, 3-Propanetroil, heated to 10‹C-40‹C above the melting point of solder on a printed circuit substrate 10. Mounted below the surface of the glycerol are ultrasonic horns 14 driven by vibrators 15 operating in the 10- 40 KHertz range and these produce a cavitation zone through which the substrate 10 is moved to remove solder therein and produce a uniform predetermined thickness of solder on the substrate. A number of passes will be necessary when the width of the substrate exceeds that of the horns. Solder may at the same time be removed from plated through holes in the substrate. |
