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AUGUST 2026 I I-CONNECT007 MAGAZINE 129 That Etchy Feeling Here's another popular and recurring question, es- pecially for newcomers to the etch process: "Can I get better etch uniformity and etch quality by chang- ing which etchant I use (most commonly from cupric chloride to alkaline etch)?" For etch uniformity, the answer is an unequivocal, absolutely not. Etch chemistry has nothing to do with why a panel etches faster or slower on different areas of the board, to the point where you can no longer meet etched line width uniformity specifications for that product. These things are usually due to misad- justed etching equipment and could go as far back in the process as imaging or even panel prepara- tion. (Plugged spray nozzles are popular, and you'd be surprised at how many people never check their nozzles.) Check these things first before wasting time on trying different etch chemistries. As far as improvement in etch quality is concerned, the answer is a qualified maybe. Alkaline etch will definitely give you a faster etch rate and, under the proper operating parameters, will improve undercut performance, giving straighter sidewalls on the T H E C H E M I CA L C O N N ECT I O N etched line traces. This comes at the expense of more difficult etchant control and environmental discomfort (ammonia in the air is unpleasant, and the ammonia/copper complex is much harder to waste-treat). There is also a lingering miscon- ception that ferric chloride etch gives better etch factor performance than cupric. This is not true, as discovered in the massive design of experiment mentioned above. Again, don't waste your time. Talk about pontificating at great length. Once again, I am approaching my word count limit (I start these things thinking I can't possibly fill the space with the word count I am given and always end up having to edit for length). Anyway, I hope this has given you something to think about and maybe save you some time. I-CONNECT007 Don Ball is a process engineer at Chemcut. To read past columns or contact Ball, click here.