Apr 03, 2003 Dross is the scum that forms on molten metal, and is a significant cost factor in electronics assembly, in terms of waste management and associated manual labor, as well as materials cost in wasted solder. Cookson is now offering an on board system that automates removal of dross from solder pots and recovers good solder from the waste material in dross. In the case of electronics, that's typically lead and tin oxide.
While recovering solder from dross is nothing new, it typically involves a chemical process or manual, laborious method, both of which are potentially hazardous to factory workers. Recently, self-contained individual dross recovery units have shown up on the market, using a mechanical process to separate good solder from the waste oxides found in dross.
By integrating recovery into the waver soldering machine and automating the process, Cookson says it has eliminated operator involvement and utilizes existing machine exhaust systems. Its system returns recovered solder automatically to the solder pot in the machine.
In a paper presented here at APEX by Jim Morris, Cookson advanced development manager, the company claims it can improve on the amount of dross saved through its integrated technology over standard manual, mechanical methods by 47 percent. The company estimates that in a single wave soldering machine operated 80 hours per week, customers could save nearly $11,544 per year using typical lead solder, and as much as $25,064 using a lead-free solder.
Users can further reclaim costs by selling unused solder back to a supplier, Morris suggested. The company already has several integrated systems operating in the field, he said.
by Jeff Chappell -- Electronic News, 4/2/2003
