Sound technical content, curated with aloha by
Ted Mooney, P.E. RET
Pine Beach, NJ

Ammonium Bifluoride for Hobbyist Quartz Crystal Etching

I want to etch some Piezo-electric Quartz crystals to a precise frequency in the range 1.8 to 10 MHz.

I have been told that Ammonium Bifluoride is a suitable etchant.

I wonder if anyone out there has experience using this chemical for this process, and can offer any advice on how to proceed, and details of any potential pitfalls. I'm particularly concerned about safety, as I will be doing the work at home.

Hydrofluoric acid burns

Never use HF anywhere unless trained!
If you do, you MUST have the antidote gel on hand for instant use!

Calcium Gluconate
for HF acid burns

on eBay or

Amazon

(affil links)

I can't help you with the suitability of ammonium bifluoride, but I use it at work every day and can probably help with the safety aspect. Firstly, if you can find anything else, use it. Ammonium bifluoride is quite dangerous. Make sure you have some calcium gluconate gel.

available in case of skin contact (this should be available from your pharmacist). If you get any on you, wash off immediately for 10-15 minutes and apply calcium gluconate gel. reapply every 15 minutes for the first hour and then every hour for 24 hours. And get medical attention.