Alternatives to Sodium Hydroxide?

[therecordingart]

I've recently given up on sodium hydroxide because I'm wasting large amounts of money to be left with regular copper clad boards over 50% of the time.

I just ordered sodium metasilicate pentahydrate powder from a Mega Electronics distributor in the U.S. Does anyone have experience with this stuff. Supposedly, you don't have to worry about over developing, and the stuff is supposed to work fast...within seconds.

Any other alternatives to sodium hydroxide?

 

[Svart]

hmm i've never had problems with sodium hydroxide. you have to make it a little dilute and use cold water. over expose your art so that it will develop quicker but use cold dilute developer so that it slows the process down a bit. i almost never have a bad develop.

never used the other stuff, but let us know how it works!

 

[Emperor-TK]

That completely depends on the chemistry of the resist. I have used some old Shipley brand solder masks that were developed in sodium carbonate (AKA washing soda), which is a much weaker base than sodium hydroxide. This isn't to be confused with sodium bicarbinate (AKA baking soda), which is a very very weak base. If the metasilicate still works too fast for your resist, try the carbonate.

I agree with Svart though, that if your resist is made to be developed in NaOH, then you should be able to adjust concentration and temp for a good etch. It is possible that if it isn't working, then your resist is either expired or had been sensitized at some point.

-Chris

 

[CJ]

I have had good luck with that Mega chemical you just bought.
This board biz is a lot of trial and error, but once you get it dialed for your setup, it is very repeatable. You can almost see when it is time to pull a board from the developer. Same with etching. So if your boards vary, and you use the same UV time, you can make up for a minor miscalc at step A by adjusting step B, etc.

 

[yan_b]

little dilute

little? i use 7 grams for a litre of water, and still get very quick results.

 

[peterc]

One tip my chemicals supplier gave me is to keep wiping the PCB as it is developing with a sponge about every 15 - 20 secs.

It makes it much easier to see the developing process take place.

My boards take about 80 secs to develop correctly.

Peter

 

[Svart]

a little dilute meaning more dilute than normal.. i use a 10:1 ratio. 10 parts water to 1 part sodium hydroxide. that works very well.

 

[fum]

[quote author="peterc"]One tip my chemicals supplier gave me is to keep wiping the PCB as it is developing with a sponge about every 15 - 20 secs.

It makes it much easier to see the developing process take place.

My boards take about 80 secs to develop correctly.

Peter[/quote]

I'll second this. I just have latex gloves on and use my fingers. Don't rub to hard, just agitate the developer over the top, and you'll see the resist coming off like ink.

If I can do this, anyone can. I'm less than scientific about it, I just look at the board until it's good and clear, and can see the copper where I need to, and yank it. =)

A splash of developer, and enough water to make sure the board is submerged is about as far as I take it.

ju

 

[therecordingart]

I got my developer from Mega (their U.S. distributor) today....and this stuff is amazing!!!! You don't have to worry about temperature at all....and you don't have to be exact for the developer to work properly.

I had a bunch of small pieces of PCB laying around so I decided to make a few stompboxes. I made a really strong mixture to start my trial and error. My boards developed in like 5 seconds...literally...without any tracks missing. I decided to see how weak I could go and had some big pieces of PCB set aside for some API preamps. I ended up with a 30 to 1 mixture that still developed my boards in about 15 seconds without any issues.

When I used sodium hydroxide I would either lose tracks completely, or I would just lose symbols or logos that people normally put on....that was on a good day....about 80% of my boards were ruined.

This stuff is great....for $20 I can make (I think) 5 or 10 litres of developer that actually has a long shelf life after making a mixture. I ended up developing 12 PCB's today, and all 12 are perfect.

So yeah....if anyone wants to start doing the photo method....this is a really no fuss way of doing it. I'm a moron most of the time and this couldn't be any easier. Also...if you want a cheap light setup....walmart sells 24" blacklight bulbs with the balasts for $10 each.

For under $100 including etchant, developer, and a table....I now have a 4 light setup mounted under a coffee table that shines on the ground. I put my chemicals on top of the table, my boards go underneath to expose...and voila. An entire PCB manufacturing work station!

 

[CJ]

Cool beans!
Yes I remember that Mega stuff being a ton nicer to work with than the Draino.

One tip on etching, you will lose about 10% of your trace thickness, so adjust your artwork accordingly.