Think & Tinker, Ltd.
P.O. Box 1606, Palmer Lake, CO 80133
Tel: (719) 488-9640, Fax: (866) 453-8473
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PREVIOUS NEXTPeroxy-Sulfuric Etching Module
Chemical Analysis/Stabilizer/Catalyst analysis II
Stabilizers that require replenishing only as a result of bath drag-out tend to produce somewhat less aggressive etchants. In spite of reduced etch rates, their near total immunity to uncontrolled exothermic reactions, reduced H2O2 consumption and higher allowable operating temperatures (55 degrees C) makes members of this class the preferred stabilizers for peroxy-sulfuric etchants used in high-throughput production environments.
Production operations usually call for the use of more expensive spray etching equipment that, in many cases, allow these less vigorous etchants to meet or exceed the performance of their more aggressive cousins. Even low-cost, low-pressure randomized spray etching with these etchants can achieve etch rates acceptable for most PCB prototyping houses. Unfortunately, corrosive aerosol generation is still a problem and must be dealt with to insure your safety and the health of the environment.
Permanent stabilizers are so effective in stabilizing the peroxide against the effects of heat and dissolved copper, it is very unlikely that solution effervescence will be observed, even in severely depleted baths. A simple, but reliable technique devised by Bill Good of the M.F. Good Co. (Westminster, CA) follows.