Workpieces containing copper, in particular copper laminated printed circuit boards, are etched in {HEAD ~ an alkaline etching agent} which contains {TAIL ~ a copper tetramine complex} as the active component 
contains
Workpieces containing copper , in particular copper laminated printed circuit boards , are etched in { HEAD ~ an alkaline etching agent } which contains { TAIL ~ a copper tetramine complex } as the active component
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH