Homebrew PCBs

I am wondering, what do people use to coat a pcb. Right now I am 
using some liquid solder flux and then using solder to coat the 
tracks. But I dont like the fact that sometimes the flux will coat 
two tracks when i solder the tracks. Thanks, Genaro

----- Original Message ----- 

From: "gmanca101" <gmanca101@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Friday, July 25, 2003 7:01 AM
Subject: [Homebrew_PCBs] Finalizing PCBs


> I am wondering, what do people use to coat a pcb. Right now I am
> using some liquid solder flux and then using solder to coat the
> tracks. But I dont like the fact that sometimes the flux will coat
> two tracks when i solder the tracks. Thanks, Genaro

I use an aerosol called Flux SK10. It's a spray-on flux that protects the
copper and can be soldered through. It's made by CRC Industries Europe n.v.
in Belgium.

Leon
--
Leon Heller, G1HSM
leon_heller@...
http://www.geocities.com/leon_heller

If it's a small board you can use the same method and clean it up 
with copperbraid.

You could also use a product like "Tinit" and plate the board.  The 
stuff I have came in a powder form that you mix with heated water.  
Dip the board in the solution and wait for a few minutes for the 
plate to build up.  I have noticed that heating the finished board 
can sometimes reveal underlying copper  --ie easybake/toaser oven 
solder method.  I'm not sure if it's an interaction of flux fumes or 
heat or whatever.
-Dal

--- In Homebrew_PCBs@yahoogroups.com, "gmanca101" <gmanca101@y...> 
wrote:

> I am wondering, what do people use to coat a pcb. Right now I am 
> using some liquid solder flux and then using solder to coat the 
> tracks. But I dont like the fact that sometimes the flux will coat 
> two tracks when i solder the tracks. Thanks, Genaro

I'm not sure what boards or process your using, but there may not be 
a need to coat the board if your using the positive resist boards. 

I haven't tried this, but Read at MG's site:
http://www.mgchemicals.com/techsupport/photo_inst.html

"Removal of resist is not necessary when soldering components to 
your board. By leaving the resist on, your circuit is protected from 
oxidation. Tin plating your board is not necessary. When soldering, 
the heat disintegrates the resist underneath the solder resulting in 
an excellent bond."

I am using the $3.99 6" x 3" boards by GC currently, but I will try 
next time to leave the resist on and solder through it. Then just 
using a flux cleaner to remove the solder flux, I suspect the final 
product might be very nice ;-)

Does anyone have a any home-brew flux remover formula?
I need to know what will clean a board of rosin flux easily/cheaply.
I am always looking for home-brewed concoctions as opposed to 
aerosol cans!



--- In Homebrew_PCBs@yahoogroups.com, "gmanca101" <gmanca101@y...> 
wrote:

> I am wondering, what do people use to coat a pcb. Right now I am 
> using some liquid solder flux and then using solder to coat the 
> tracks. But I dont like the fact that sometimes the flux will coat 
> two tracks when i solder the tracks. Thanks, Genaro

Thanks for those who replied. I am using the toner transfer method, 
so i guess my best bet is some tinnit. What i do to clean of the 
liquid flux is by using a toothbrush with rubbing alcohol to remove 
the excess. I have a few more questions, One, what is the best 
technique to solder an ic socket on double sided pcbs? And secondly, 
In Eagle Cad, how does one increase the width of the tracks when you 
autoroute a board? Thanks, Genaro

I use the pos. M.G. Chemical boards.  I leave the resist on the 
board, when finished spray it with clear lacquer.

Ben

> Thanks for those who replied. I am using the toner transfer 
method, 
> so i guess my best bet is some tinnit. What i do to clean of the 
> liquid flux is by using a toothbrush with rubbing alcohol to 
remove 

You can still after you clean your board just spray it with the 
clear lacquer, this will protect the bare copper.

Ben

In Eagle, just go to Edit -> Design Rules -> Sizes
You can change the signal layers minimum width there.
Design Rules is where you apply most of the dimensional parameters.

--- In Homebrew_PCBs@yahoogroups.com, "gmanca101" <gmanca101@y...> 
wrote:
> Thanks for those who replied. I am using the toner transfer 
method, 
> so i guess my best bet is some tinnit. What i do to clean of the 
> liquid flux is by using a toothbrush with rubbing alcohol to 
remove 
> the excess. I have a few more questions, One, what is the best 
> technique to solder an ic socket on double sided pcbs? And 
secondly, 
> In Eagle Cad, how does one increase the width of the tracks when 
you 
> autoroute a board? Thanks, Genaro

starsnstripes_2003 wrote:
> I'm not sure what boards or process your using, but there may not be 
> a need to coat the board if your using the positive resist boards. 
> 
> I haven't tried this, but Read at MG's site:
> http://www.mgchemicals.com/techsupport/photo_inst.html
> 
> "Removal of resist is not necessary when soldering components to 
> your board. By leaving the resist on, your circuit is protected from 
> oxidation. Tin plating your board is not necessary. When soldering, 
> the heat disintegrates the resist underneath the solder resulting in 
> an excellent bond."
> 
> I am using the $3.99 6" x 3" boards by GC currently, but I will try 
> next time to leave the resist on and solder through it. Then just 
> using a flux cleaner to remove the solder flux, I suspect the final 
> product might be very nice ;-)
> 
> Does anyone have a any home-brew flux remover formula?
> I need to know what will clean a board of rosin flux easily/cheaply.
> I am always looking for home-brewed concoctions as opposed to 
> aerosol cans!

A small amount of "super safewash 2000" brushed on with a paintbrush
dissolves the flux and you can rinse it under the tap with water
(it's water based and biodegradeble). You can get it in 1 Lt bottles.

Hi Genaro,

Unless my boards are going to be used in a particularly damp environment I
usually spray them with rework solder spray before soldering and use
no-clean fluxed solder. It helps to heat the boards up after spraying
because the flux takes a while to dry fully.
 The flux can be left on the boards and protects the copper nicely. It is
also very easy to rework the boards at a later date.

If you use liquid flux it may be worth checking if it is safe to leave on
the board. I occasionally have to work on 30 year old electronic church
organs. All the pcbs were painted with liquid flux before assembly. The
copper is still bright today even when they have spent their life in a damp
church.

I use two techniques for soldering the top side if IC sockets. The first is
to use a very long, thin tip and solder normally. This is fine if there is
plenty of room. The second method is to use a standard tip on the solder
side to heat up the leg, then feed the solder in on the component side. It
helps to mount the board vertically in some sort of clamp so you can get to
both sides at the same time.

Les

> Thanks for those who replied. I am using the toner transfer method,
> so i guess my best bet is some tinnit. What i do to clean of the
> liquid flux is by using a toothbrush with rubbing alcohol to remove
> the excess. I have a few more questions, One, what is the best
> technique to solder an ic socket on double sided pcbs? And secondly,
> In Eagle Cad, how does one increase the width of the tracks when you
> autoroute a board? Thanks, Genaro
>