Glass Etching

[vinoodd]

Hello everybody,

I am in search of a simple process/setup with which we can make Reticles or Graticules.

Can anybody guide me Please...

[chemisttree]

Photolithography followed by HF etch.

[vinoodd]

Dear chemisttree,

Thanxs for the reply.

However, can u plzz explain the process in details? I really doubt whether HF etching is used in this process coz we see perfect 10 microns line in the reticle., and i dont think its possible to etch using HF that much perfectly.

Also, is there any way that we can coat a photographic solution (similar to the photographic film used in camera) in clear glass and expose it with a negative master - contact printing process, and process it like we do it with camera films and get an exact copy of the image?

[chemisttree]

Dear chemisttree,

Thanxs for the reply.

However, can u plzz explain the process in details? I really doubt whether HF etching is used in this process coz we see perfect 10 microns line in the reticle., and i dont think its possible to etch using HF that much perfectly.

But it can.... (http://en.wikipedia.org/wiki/Etching_(microfabrication)#Wet_etching)

Also, is there any way that we can coat a photographic solution (similar to the photographic film used in camera) in clear glass and expose it with a negative master - contact printing process, and process it like we do it with camera films and get an exact copy of the image?

That is called "photolithography". (http://en.wikipedia.org/wiki/Photolithography)

[sciler]

When you say HF, are you guys talking about hydrofluoric glass etching (http://www.glassetchingsecrets.com/acid.html) acid? That stuff is nasty. I have worked with this before and its quite dangerous.

[Mapes]

Hi sciler, welcome to PF. They are indeed! I used to use 49% HF frequently in microfabrication work. I always used a fume hood, face mask, apron, sleeve covers, and two sets of gloves, and I had a tube of calcium gluconate taped to the hood. It is a very dangerous material to work with without the proper protective equipment.

[sciler]

Mapes, sorry if this sounds dumb. But what does the calcium gluconate do? I take it, its some kind of neutralizer or filter. Just a guess, please let me know.

[Mapes]

In case you spill HF on yourself, calcium gluconate provides a calcium source for the voracious fluoride ions that's not your tissue.

[sciler]

Ok thats what I kind of figured. Thank you so much for giving me this information. I really appreciate it.

[mgb_phys]

Just to reinforce - HF is one of the nastiest chemicals that isn't actually a weapon.
It's not just the acidity, it has some very nasty chemical properties, one of which is that it doesn't actually hurt when you spill it on you - supposedly it can burn through your hand before you notice.
My wife is a chemist and this is the one substance she is scared of.

[nimmysnv]

Just to reinforce - HF is one of the nastiest chemicals that isn't actually a weapon.
It's not just the acidity, it has some very nasty chemical properties, one of which is that it doesn't actually hurt when you spill it on you - supposedly it can burn through your hand before you notice.
My wife is a chemist and this is the one substance she is scared of.

Hafnium is not exactly weaapon but, it is metal which is used in making control rods in nuclear reactors and nuclear submarines which is excellent at absorbing neutrons and it has very high melting point.


Thanks!

[Borek]

Hafnium is not exactly weaapon

And HF is not exactly a hafnium.

You know, HF is different from Hf, we don't use these capital letters without reason.

--
chemical calculators (http://www.chembuddy.com) - buffer calculator (http://www.chembuddy.com/?left=Buffer-Maker&right=buffer-calculator), concentration calculator (http://www.chembuddy.com/?left=CASC&right=concentration_and_solution_calculator)
www.titrations.info (http://www.titrations.info) - all about titration (http://www.titrations.info) methods

[nimmysnv]

And HF is not exactly a hafnium.

You know, HF is different from Hf, we don't use these capital letters without reason.

--
chemical calculators (http://www.chembuddy.com) - buffer calculator (http://www.chembuddy.com/?left=Buffer-Maker&right=buffer-calculator), concentration calculator (http://www.chembuddy.com/?left=CASC&right=concentration_and_solution_calculator)
www.titrations.info (http://www.titrations.info) - all about titration (http://www.titrations.info) methods

Oh! I got little confused, but really thankful that you cleared my confusion.


Thanks!

[sciler]

mgb_phys, I have heard that too. Thats crazy how it can penetrate the skin to the insides and eat at the bone. I am with your wife, I am scared of it already also. I think I'll just stay away from it lol. Thanks for the info.

[pseudophonist]

HF is freaking scary. I've heard tell that Calcium Gluconate isn't a complete protection and that if you do spill some on you:
1) apply the gluconate
2) CALL AN AMBULANCE

That said, a lecturer of mine told me he improperly disposed of a lot down a drain, and got fumed badly. He's still walking

[Lok]

I'm sure HF can make some nasty burns but to get all the way through your hand you would need to keep poring, a lot of it... and for some time, it's not that fast as the reactions aren't that fast. I'ts nasty as it kinda burns through many anorganics.

I've worked in photoetching for a short time, and honestly i've found lots more about it from wikipedia.

We etched metal films of up to 0.1mm with 0.1mm holes, lines any shapes. It's easy to do at home with nail polish but the precision drops by a mile.

[sciler]

Really, what kind resist did you use for photoetching with this acid?

[Mapes]

Most standard microfabrication photoresists (e.g., AZ line, OCG825, novolac resin based) can handle dilute HF with no problems. With 49% HF, resist attack is a real problem. Tougher epoxy resists like SU-8 are sometimes used here.

[Lok]

Really, what kind resist did you use for photoetching with this acid?

Never worked with HF as it was metal film that we processed. It would have dissolved the titanium frame of the installation anyway :P .