Well, no time for searching..
I decided to apply a clear coat on the copper side of the board, to prevent oxidizing.
I did that after soldering and testing the board to make sure its rocking.
I was aware that I would not be able to take measures with the multimeter after the coat,
but the fact is that all the wires are shorting after the clear coat...
What I am missing?
I started to apply a remover after that, the continuity test is showing a little resistance, but some wires are still shorted.
Any suggestions?
Thanks
PS.: I searched a little and I found some products that may do the job. Meanwhile I read the composition of the 'clear coat' that I've used; will these components lead to short connections? = metallic pigment, titanium dioxide, aluminum silicate
Quote from: Guerrilha Music on June 04, 2021, 09:11:17 PM
Well, no time for searching..
I decided to apply a clear coat on the copper side of the board, to prevent oxidizing.
I did that after soldering and testing the board to make sure its rocking.
I was aware that I would not be able to take measures with the multimeter after the coat,
but the fact is that all the wires are shorting after the clear coat...
What I am missing?
I started to apply a remover after that, the continuity test is showing a little resistance, but some wires are still shorted.
Any suggestions?
Thanks
PS.: I searched a little and I found some products that may do the job. Meanwhile I read the composition of the 'clear coat' that I've used; will these components lead to short connections? = metallic pigment, titanium dioxide, aluminum silicate
Yes.
Why does clearcoat have pigment in it, that's not clearcoat that's paint. Watch out for carbon black too.
Try a mist coat of clear lacquer.
dave
You can buy clear lacquer for PCBs. There's a few types. You want the basic clear pcb lacquer not the conformal coating stuff.
I think it's the polyurethane clear gloss lacquer you want. You can solder through it if you have to. The Poly' isn't as common as it once was - acrylics have taken a lot of the DIY/Decor market.
All right!
Tks for the tips
Whenever I etch a board these days, I immediately wipe it with liquid flux after the resist is removed, and tin the whole thing with solder, then clean the flux off with methyl hydrate, before I drill a single hole. Works like a charm. Doesn't take much solder, either, and the flux helps that tiny bit spread easily. Solder will eventually tarnish, but not nearly as quickly as exposed copper.
Quote from: Mark Hammer on June 05, 2021, 11:36:13 AM
Whenever I etch a board these days, I immediately wipe it with liquid flux after the resist is removed, and tin the whole thing with solder, then clean the flux off with methyl hydrate, before I drill a single hole. Works like a charm. Doesn't take much solder, either, and the flux helps that tiny bit spread easily. Solder will eventually tarnish, but not nearly as quickly as exposed copper.
+1 to that. I do it too. Just be sure to do it before drilling holes, as pointed by Mark.
Quote from: Marcos - Munky on June 05, 2021, 12:06:28 PM
Quote from: Mark Hammer on June 05, 2021, 11:36:13 AM
Whenever I etch a board these days, I immediately wipe it with liquid flux after the resist is removed, and tin the whole thing with solder, then clean the flux off with methyl hydrate, before I drill a single hole. Works like a charm. Doesn't take much solder, either, and the flux helps that tiny bit spread easily. Solder will eventually tarnish, but not nearly as quickly as exposed copper.
+1 to that. I do it too. Just be sure to do it before drilling holes, as pointed by Mark.
Even if theres a big ground plane you cover with solder?
After cleaning the flux, you dont apply anything to protect the solder?
I started to print small traces and cover the traces with solder, assuming that it will be more resistent and less prone to break than the copper itself. But I thought it wasn't economic.
Marcos, can you point these products in Brazil: flux and clean lacquer pcb?
I'm having trouble to translate and find the right lacquer.
I think this guy is using 'breu' and 'alcool isopropilico' to make his own flux.
https://www.youtube.com/watch?v=MY4QdROhu6w (https://www.youtube.com/watch?v=MY4QdROhu6w)
I'll try this out:
- Etch the board (I'm drilling before etching)
- Apply flux all the board, this > https://www.baudaeletronica.com.br/fluxo-para-solda-500ml.html
- Populate
- Aplly lacquer, this > https://www.baudaeletronica.com.br/isotec-verniz-protetivo-170-g-300-ml.html
Sound good?
I tried to find a non-conformal as pointed by Rob, but wasn't lucky
PS. I was perfuratng a bit out of center so I use a pen to make up, then etching after drilling. But now I got some skills to perfurate it right and maybe I should switch the order and etch before drill
Quote from: Guerrilha Music on June 05, 2021, 12:27:48 PM
I'll try this out:
- Etch the board (I'm drilling before etching)
- Apply flux all the board, this > https://www.baudaeletronica.com.br/fluxo-para-solda-500ml.html
- Populate
- Aplly lacquer, this > https://www.baudaeletronica.com.br/isotec-verniz-protetivo-170-g-300-ml.html
Sound good?
I tried to find a non-conformal as pointed by Rob, but wasn't lucky
PS. I was perfuratng a bit out of center so I use a pen to make up, then etching after drilling. But now I got some skills to perfurate it right and maybe I should switch the order and etch before drill
With any of the lacquers i've used whether water based or spirit based a light coating of the bare copper after etching will protect the copper from oxidizing. No issues at all in soldering to the lacquered copper and i've had boards sit for a few year before populating and soldering and the lacquered boards solder like to freshly etched, newly exposed copper. Works great, quick and easy to do, very economical.
Etch before drilling and if the hole center of the etched pads is the right size, it can help the drill bit self center in the etched pad, very light touch on the drill advancement and the board gently secured/held.
dave
Quote from: Guerrilha Music on June 05, 2021, 12:20:36 PM
Even if theres a big ground plane you cover with solder?
After cleaning the flux, you dont apply anything to protect the solder?
Yes. Especially big ground planes. The reason is that if I am going to add any more controls or jacks, I'll need a good easy place to attach ground wires. Solder covering the ground plane lets me connect a ground wire o any part of it.
And no, I do not cover the solder with anything. Can it
possibly oxidize/tarnish? Yes, but it will take several years. It's my own preference. No obligation on anyone else to copy me.
this is a great cautionary tale, haha
cheers
+1 for tining the whole thing before soldering. Protects the board and helps with the solder. I do it with perfboard too.
I just "draw" the traces with a bead of solder. On planes/perfboard I use a strip of copper braid saturated with solder.
''With any of the lacquers i've used whether water based or spirit based a light coating of the bare copper after etching will protect the copper from oxidizing.''
yep, ive done this with home made pcbs, a shot of clearcoat, and you can still solder through it no problem..
and retain the shine/protection years later...
Quote from: Mark Hammer on June 05, 2021, 01:32:43 PM...Can it possibly oxidize/tarnish?....
If it does, a touch of the iron will break it up. (Unlike copper oxides.)
Quote from: Guerrilha Music on June 05, 2021, 12:20:36 PM
Even if theres a big ground plane you cover with solder?
After cleaning the flux, you dont apply anything to protect the solder?
I started to print small traces and cover the traces with solder, assuming that it will be more resistent and less prone to break than the copper itself. But I thought it wasn't economic.
Marcos, can you point these products in Brazil: flux and clean lacquer pcb?
I'm having trouble to translate and find the right lacquer.
I think this guy is using 'breu' and 'alcool isopropilico' to make his own flux.
https://www.youtube.com/watch?v=MY4QdROhu6w (https://www.youtube.com/watch?v=MY4QdROhu6w)
Verdade, você é brasileiro. Eu uso pasta de solda da cobix, não é o recomendado mas funciona. Aquele que você postou o link é melhor. O verniz, também o que você postou. E, assim como o Mark, eu cubro toda a placa, até mesmo quando tem bastante plano de terra.
Sobre o procedimento que você postou, o correto é corroer e já aplicar o verniz. O fluxo você pode aplicar na hora de soldar pra facilitar, e depois limpa com álcool isopropílico. Se aplicar o fluxo primeiro e depois o verniz, fica uma lambuzeira na placa e o verniz não adere direito. Caso você opte pela camada de solda, passa o fluxo pela placa toda antes de furar, aplica uma pequena gotinha de solda e vai espalhando ela pela placa. Você vai ver que pouquinha solda vai ser o suficiente pra cobrir um bom tanto do cobre, o fluxo ajuda a espalhar. Depois que cobrir tudo, lava com álcool, de preferência isopropílico, e aí é só furar e soldar. Nesse método, nem precisa de fluxo pra soldar, o próprio estanho já aplicado na placa facilita até demais.
TL,DR for non portuguese speakers :icon_mrgreen:: they're also brazilian, I replied in portuguese cause they asked for help on finding flux and lacquer here. Basically, I said I also cover ground planes with solder. If they go this way, then flux goes forst (before drilling the board), then just a bit of solder will be enough to cover the whole board. Then clear the board with isopropyl alcohol. If they go with lacquer, then it's lacquer first, then flux to help the soldering, and then clear the flux with isopropyl alcohol.
Valeu, Marcos!
Quote from: Marcos - Munky on June 06, 2021, 10:35:15 AM
Verdade, você é brasileiro. Eu uso pasta de solda da cobix, não é o recomendado mas funciona. Aquele que você postou o link é melhor. O verniz, também o que você postou. E, assim como o Mark, eu cubro toda a placa, até mesmo quando tem bastante plano de terra.
Pasta da Cobix, vulgo cera de ouvido, funciona bem. Nunca entendi por que não é recomendada. Também fui descobrir "fluxo" propriamente dito bem depois, pela internet.
Pra espalhar solda, eu gosto de usar um pedaço de malha de cobre. Funciona como um pincel. Ajuda a "pular" o espaço entre as trilhas. O importante é mão ficar muito tempo num local, pra não descolar as trilha da placa.
Se cobrir a placa toda com solda, pode lavar com água e sabão também. O cobre vai estar protegido.
tl;dr;en: After covering the traces and planes with solder, you can wash the board with soap and water. Copper is already protected after all.
I've used automotive clear coat spray paint without any trouble. I like using "stained glass" or "headlight tint" spray paint as well. Definitely check the ingredients if you can find the sheet. But usually anything that's obviously nonmetallic is fine.
If you're into science experiments you could also make your own liquid tin. Made a thread a couple years back on that.
Homemade Liquid Tin Thread (https://www.diystompboxes.com/smfforum/index.php?topic=122300.0)
Quote from: marcelomd on June 07, 2021, 09:49:48 AM
Pasta da Cobix, vulgo cera de ouvido, funciona bem. Nunca entendi por que não é recomendada.
Aquela pasta da cobix que vem no potinho laranjado é corrosiva. Ela é feita pra soldas mais brutas, tipo soldar canos. Até dá pra usar em placas, mas se você não limpar bem, ela oxida e pode resultar em descontinuidade. Uma vez eu fiz uma placa, soldei, e só depois passei a pasta e fiz a camada de estanho. Funcionou por um tempo, depois parou tudo, e tive que refazer a placa. Em outra, furei a placa antes de fazer a camada de estanho. Deixei a placa guardada por umas semanas, quando fui pegar pra montar a pasta que estava nos furos entrou em contato com o cobre e oxidou tudo. O certo mesmo é usar na placa sem furos, fazer a camada de estanho, depois limpar muito bem.
Quote from: Marcos - Munky on June 09, 2021, 12:42:23 PM
Quote from: marcelomd on June 07, 2021, 09:49:48 AM
Pasta da Cobix, vulgo cera de ouvido, funciona bem. Nunca entendi por que não é recomendada.
Aquela pasta da cobix que vem no potinho laranjado é corrosiva. Ela é feita pra soldas mais brutas, tipo soldar canos. Até dá pra usar em placas, mas se você não limpar bem, ela oxida e pode resultar em descontinuidade. Uma vez eu fiz uma placa, soldei, e só depois passei a pasta e fiz a camada de estanho. Funcionou por um tempo, depois parou tudo, e tive que refazer a placa. Em outra, furei a placa antes de fazer a camada de estanho. Deixei a placa guardada por umas semanas, quando fui pegar pra montar a pasta que estava nos furos entrou em contato com o cobre e oxidou tudo. O certo mesmo é usar na placa sem furos, fazer a camada de estanho, depois limpar muito bem.
Hmmm I usually etch, drill, tin and wash right away. Then I'll solder and wash again with isopropil alcohol and a toothbrush. I hate the residue that paste leaves. It gets gooey and nasty.
Quote
Etch before drilling and if the hole center of the etched pads is the right size, it can help the drill bit self center in the etched pad, very light touch on the drill advancement and the board gently secured/held.
dave
Yes
Blz!
Encomendei uma pasta e fluxo (no clean) da Implastec, além do verniz.
Vou primeiro tentar fazer o esquema de espalhar o fluxo e cobrir com solda.
Uma coisa que já mudei aqui e deu certo foi furar depois de corroer; com o meio do pad corroído facilita centralizar a broca.
Testei também goma-laca como verniz; dá até pra soldar por cima, mas acredito que sirva só pra guardar a placa por um tempo caso não for soldar na hora e quando for soldar remover tudo com álcool.
PS.: caso use o verniz apropriado pra finalizar, não aplica no lado dos componentes, certo?
Just saying I tested etching before drilling (done good), experiment with shellac, etc. while waiting for a proper flux and lacquer.
(https://i.postimg.cc/0rfL4TDc/20210608-001611.jpg) (https://postimg.cc/0rfL4TDc)
The companies I used to deal with used solder plating which is a room-temperature process that does not stress the connection between the copper and the board. We found that high tin content in the plating made for very pretty almost mirror-finish boards but the duller boards with more lead in the mix actually soldered better.
At one time, there were 45 PCB shops in the Toronto area. We used to use Graphico Precision a lot but we tried out a few more like Metaplast just to have a second source. I am not sure any PCB houses remain.
I built most of the EH Rack Guitar Synth on vero (como siempre!!) in 1980 - no treatment and no oxidisation yet - after 41 years!!!
QuoteI built most of the EH Rack Guitar Synth on vero (como siempre!!) in 1980 - no treatment and no oxidisation yet - after 41 years!!!
All the Vero I've ever had, and also those pre-made patternated boards for IC's, have been pre-coated with a fine clear lacquer by the manufacturer That's why they never oxidize on the shelf in the stores.
I've got an old piece of vero from 1994 which is in my junk parts and it gets handled a bit more than normal because I'm digging through the pile. It's just starting to develop small areas of oxidation partly because some lacquer has rubbed off against other parts and partly because the lacquer is starting to decompose and flake. The other half of the same piece has been stored away in a box for years without anyone touching it. I haven't looked at it for a while. It would be interesting to see what state it is in.
EDIT:
I'm talking about the ones that look like copper here. Some were tinned and I'm sure a lot of those didn't have lacquer.