Is PCB tinning necessary?

[swever]

Last weekend I had my first attempt at making my own PCBs. Turned out really well from the word go! Looks and works great, and the process is not that hard I as I thought it would be. However, tinning did not work out that great, and is a bit of a PITA to do. I have seen several pictures of DIY PCBs that did not have any tinnig on them at all. Is it okay? Is there any risk that the tracks are going to deteriorate with time and cause any malfunctions?

[amptramp]

A lot of consumer-grade equipment has been built with bare copper boards.  When wave-soldering caught on, boards were automatically tinned, but this was a byproduct of a process rather than a requirement.  Untinned boards only deteriorate in an environment where they can get moisture that turns copper into various copper sulphates and carbonates.

Your problem of the boards not accepting tinning may also mean they can't be soldered, so lack of tin is not a problem but inability to accept tin is.

[EBK]

Looking at your pics, it appears that you didn't have enough flux to make the solder flow nicely.
I would suggest trying to tin your next board with some extra flux on the traces, or dip your iron into some paste flux right before touching it to the board.  If you find it easier to do next time, then you won't really need to worry about whether or not the risk of corrosion makes tinning worthwhile. 

[armdnrdy]

Looking at your pics, it appears that you didn't have enough flux to make the solder flow nicely.
I would suggest trying to tin your next board with some extra flux on the traces, or dip your iron into some paste flux right before touching it to the board.  If you find it easier to do next time, then you won't really need to worry about whether or not the risk of corrosion makes tinning worthwhile. 

Flux? If you look at the OPs second picture...it appears that he tinned the board with a chemical tinning process.

[EBK]

Looking at your pics, it appears that you didn't have enough flux to make the solder flow nicely.
I would suggest trying to tin your next board with some extra flux on the traces, or dip your iron into some paste flux right before touching it to the board.  If you find it easier to do next time, then you won't really need to worry about whether or not the risk of corrosion makes tinning worthwhile. 

Flux? If you look at the OPs second picture...it appears that he tinned the board with a chemical tinning process.

Thought that was some non-ferric-chloride etchant.  Oh well. 

[swever]

It actually was rosin alcohol flux. I just finished tinning another one with much better result this time. Applied more flux and spread it around more quickly before it started drying up. I am still having a bit of trouble getting an even (an minimal) layer of tin all over the board, but this time it's much better.

And yea, sorry for the confusion. The teal solution on the picture is the etchant - hydrogen peroxide + сіtric acid + sodium chloride.

[Magnus]

Hello,
I spray some solder fluid on it - then it accepts solder very well 


Greetings
Magnus

[karbomusic]

However, tinning did not work out that great, and is a bit of a PITA to do. I have seen several pictures of DIY PCBs that did not have any tinnig on them at all. Is it okay? Is there any risk that the tracks are going to deteriorate with time and cause any malfunctions?

Unless you are trying some tricks for increasing current/lowering resistance, or want to somewhat over build it (which can have value) I don't see the need - that is if you are manually tinning with solder - if using a tinning solution... You can as easily, very easily just spray a very thin coat of clear lacquer which will keep the copper like new as far as oxidation goes and the soldering iron burns right through it. It'll also help protect against foreign matter causing shorts aka poor man's solder mask - ask me how I know that.

Now for the art of it, some do some incredibly cool work.

[armdnrdy]

Looking at your pics, it appears that you didn't have enough flux to make the solder flow nicely.
I would suggest trying to tin your next board with some extra flux on the traces, or dip your iron into some paste flux right before touching it to the board.  If you find it easier to do next time, then you won't really need to worry about whether or not the risk of corrosion makes tinning worthwhile. 

Flux? If you look at the OPs second picture...it appears that he tinned the board with a chemical tinning process.

Thought that was some non-ferric-chloride etchant.  Oh well. 

You were correct! My mistake. I wouldn't have imagined an image of etching the board in a tinning thread.

[Mark Hammer]

I always buff my etched boards and swab them all over with liquid flux immediately.  Then I tin them.
The reason is that I nearly always end up changing parts or adding options, so I need to have every pad and trace available for duty.  Tinning means they won't tarnish in an unredeemable way.

That strategy works for me, but may be irrelevant to a lot of folks.

[GiovannyS10]

Tinning? I personally never liked the result of it. My way to turn my tracks okay until the end of times is simple. I dissolute pitch-dark resin [breu in portuguese] in Isopropyl Alcohol, It work very fine for me. 1 part of resin for 5 of alcohol. If you think it are too much thick, double the alcohol quantity.

It help a lot, protect the board and help to solder.

[J0K3RX]

dip or rub on Silver plate.. there a few out there

https://www.jaxchemical.com/jaxshop/shopexd.asp?id=76

http://www.cool-amp.com/cool_amp.html

[davent]

However, tinning did not work out that great, and is a bit of a PITA to do. I have seen several pictures of DIY PCBs that did not have any tinnig on them at all. Is it okay? Is there any risk that the tracks are going to deteriorate with time and cause any malfunctions?

Unless you are trying some tricks for increasing current/lowering resistance, or want to somewhat over build it (which can have value) I don't see the need - that is if you are manually tinning with solder - if using a tinning solution... You can as easily, very easily just spray a very thin coat of clear lacquer which will keep the copper like new as far as oxidation goes and the soldering iron burns right through it. It'll also help protect against foreign matter causing shorts aka poor man's solder mask - ask me how I know that.

Now for the art of it, some do some incredibly cool work.

A light spray with lacquer works great. I found Liquid Tin no better then leaving the bare copper untreated.

dave

[karbomusic]

I found Liquid Tin no better then leaving the bare copper untreated.

dave

Same here, it's fun and looks kind of cool but I didn't find it any better bare so I switched back to lacquer.

[Electron Tornado]

An electronics tech I know told me several years ago that using clear nail polish works well for protecting the copper.

[LiLFX]

After you've etched your board use acetone and scotchbrite to get your copper super clean. Instead of tinning the traces you can use a light coat of acrylic clear coat (or Humiseal if you want to spend money) which you can solder through. You'll have to be a bit for diligent with cleaning the tip of your soldering iron, but it works really well. I've found that liquid tin isn't the greatest, and at times it has aged poorly.

[amptramp]

At one company I was at, we used to buy in circuit boards that were solder plated.  In some cases, the manufacturer upped the tin content to make the boards look bright with almost a chrome-like finish.  Other boards looked a little more dull because of more lead content.  But we found that the dull boards soldered much more easily than the bright boards, so we started making that part of the requirements.  Or maybe we just felt more kinship with the dull.

[thermionix]

An electronics tech I know told me several years ago that using clear nail polish works well for protecting the copper.

Clear nail polish is nitrocellulose lacquer.

[DavidRavenMoon]

Clear nail polish is nitrocellulose lacquer.

Or acrylic lacquer. But either way, it's lacquer.

[swever]

Lots if interesting info, thanks peeps! However, I am not sure if smelling burning laquer is a better option than torturous tinning. Will have to try and see which one is the lesser evil.

Anyway, here's my second attempt at tinning.