Homebrew PCBs

Hi,

 

Having gotten beyond toner transfer and etching (more below), I'm
finally assembling my very first board. I find that it's harder to
solder than other PCBs I've purchased. The solder pools on the wire or
pin and doesn't easily attach to the pad. I expect the solder to "suck
up" when the area is hot enough, but it doesn't. 

 

Could it be that the Liquid Tin-coated pad is less solderable than bare
copper? Could it be the lack of plated-through holes that prevent it
from "sucking up?" Must I replace my elderly (though good at all other
jobs) temperature-controlled Ungar soldering iron? Could it be that I
need a new tip, even though it looks perfect? I'll try using liquid flux
next, but any advice is appreciated. 

 

Regarding etching, I used Pulsar's sponge method. It worked very well,
though it took a bit longer than claimed. Afterward, though, I would up
with a black, extremely filthy sponge. According to an article I earlier
uploaded, Sodium Hydroxide (NaOH) is supposed to neutralize FeCl3,
producing salt water and a non-toxic precipitate. Well, I tried to find
Sodium Hydroxide. A pool store and a hardware store never heard of it.
(Maybe I should have asked for lye or caustic soda instead.) I thought
manufacturers were supposed to list ingredients, but that apparently
doesn't apply to drain cleaners. I finally bought Drano Kitchen
Crystals; at least they warned against misuse of Sodium Hydroxide.

 

Sooo, I added enough water to cover the sponge in my (fortunately)
disposable plastic leftover tray - about 14 oz --  and poured in an
(eyeballed) tablespoon of Kitchen Crystals. I wound up with a brown mess
with brown things floating in it. Frankly, it looked like diarrhea! Can
anyone hazard a guess at what this stuff is? Without knowing what it is,
I don't want to put it in my toilet; I don't need a plumbing bill! Our
storm drains around here drain to the ocean and I'd rather not kill any
fish I don't have to. Right now, I'm planning to hold it, sponge
included, until our next HazMat collection day and let the county handle
it. 

 

For the future, how should I clean up after etching? Should I just
figure on killing a sponge for every job? Would re-using the same filthy
sponge for several jobs be ok before giving it to HazMat? I'm thinking
of using Pulsar's "Baggie" alternative to the sponge method next time.
Has anyone tried this? Does it work well?

 

Jim

 



[Non-text portions of this message have been removed]

HI,

 

IPA?????

 

Jim

From: Homebrew_PCBs@yahoogroups.com
[mailto:Homebrew_PCBs@yahoogroups.com] On Behalf Of Leon Heller
Sent: Tuesday, February 23, 2010 6:01 PM
To: Homebrew_PCBs@yahoogroups.com
Subject: Re: [Homebrew_PCBs] Solderability and Etching

 

  

On 24/02/2010 01:23, Jim Barnes wrote:
> Hi,
>
>
>
> Having gotten beyond toner transfer and etching (more below), I'm
> finally assembling my very first board. I find that it's harder to
> solder than other PCBs I've purchased. The solder pools on the wire or
> pin and doesn't easily attach to the pad. I expect the solder to "suck
> up" when the area is hot enough, but it doesn't.

My photo-etch boards are very easy to solder. I remove the resist with 
paper towel moistened with IPA.

Leon
-- 
Leon Heller
G1HSM





[Non-text portions of this message have been removed]

On 24/02/2010 01:23, Jim Barnes wrote:
> Hi,
>
>
>
> Having gotten beyond toner transfer and etching (more below), I'm
> finally assembling my very first board. I find that it's harder to
> solder than other PCBs I've purchased. The solder pools on the wire or
> pin and doesn't easily attach to the pad. I expect the solder to "suck
> up" when the area is hot enough, but it doesn't.

My photo-etch boards are very easy to solder. I remove the resist with 
paper towel moistened with IPA.

Leon
-- 
Leon Heller
G1HSM

--- In Homebrew_PCBs@yahoogroups.com, "Jim Barnes" <jim@...> wrote:
>
> Hi,
> 
>  
> 
> Having gotten beyond toner transfer and etching (more below), I'm
> finally assembling my very first board. I find that it's harder to
> solder than other PCBs I've purchased. The solder pools on the wire or
> pin and doesn't easily attach to the pad. I expect the solder to "suck
> up" when the area is hot enough, but it doesn't. 
> 


The only time I had any trouble was when I drilled a board on a milling machine and got cutting fluid on it that I got on my hands. Wash the board with warm soapy water and dry it off before soldering. You might wipe it down with acetone as well to make sure all traces of resist are removed.

Isopropyl Alcohol? ("Rubbing alcohol").

(to me it's International Phonetic Alphabet, but that can't be right)

PG

On Wed, Feb 24, 2010 at 1:03 PM, Jim Barnes <jim@...> wrote:

>
>
> HI,
>
> IPA?????
>
> Jim
>
> From: Homebrew_PCBs@yahoogroups.com <Homebrew_PCBs%40yahoogroups.com>
> [mailto:Homebrew_PCBs@yahoogroups.com <Homebrew_PCBs%40yahoogroups.com>]
> On Behalf Of Leon Heller
> Sent: Tuesday, February 23, 2010 6:01 PM
> To: Homebrew_PCBs@yahoogroups.com <Homebrew_PCBs%40yahoogroups.com>
> Subject: Re: [Homebrew_PCBs] Solderability and Etching
>
>
> On 24/02/2010 01:23, Jim Barnes wrote:
> > Hi,
> >
> >
> >
> > Having gotten beyond toner transfer and etching (more below), I'm
> > finally assembling my very first board. I find that it's harder to
> > solder than other PCBs I've purchased. The solder pools on the wire or
> > pin and doesn't easily attach to the pad. I expect the solder to "suck
> > up" when the area is hot enough, but it doesn't.
>
> My photo-etch boards are very easy to solder. I remove the resist with
> paper towel moistened with IPA.
>
> Leon
> --
> Leon Heller
> G1HSM
>
> [Non-text portions of this message have been removed]
>
>  
>


[Non-text portions of this message have been removed]

IPA = Isopropyl Alcohol...  I think anyway.  Doesn't do much for cutting my HP toner.  After wiping good with acetone my board solder nicely - just be sure to use flux.

Ken

On 24/02/2010 02:03, Jim Barnes wrote:
> HI,
>
>
>
> IPA?????

India Pale Ale. 8-)

It's actually iso-propyl alcohol. I use the 99% stuff.

Leon
-- 
Leon Heller
G1HSM

On 24/02/2010 04:25, Piers Goodhew wrote:
> Isopropyl Alcohol? ("Rubbing alcohol").

I think that rubbing alcohol has an oil in it (wintergreen?). That will 
cause problems.

Leon
-- 
Leon Heller
G1HSM

On 24/02/2010 05:13, sailingto wrote:
> IPA = Isopropyl Alcohol...  I think anyway.  Doesn't do much for cutting my HP toner.  After wiping good with acetone my board solder nicely - just be sure to use flux.

When I tried TT I found that cellulose paint thinners (xylene) did a 
good job.

Leon
-- 
Leon Heller
G1HSM

In article
<40B5325EDFC7D64F83DC128117C0AD2325AD55@...>,
   Jim Barnes <jim@...> wrote:
> Could it be that the Liquid Tin-coated pad is less solderable than bare
> copper?

I found it didn't seem to tin easily for some reason but it does seem to
depend on the quality of the rinsing after plating.

Flux may be the key though, I have a spray can of re-flow solder flux
which I spray onto freshly etched boards.

-- 
Stuart
http://www.torrens.org.uk/ZFC/gallery/winsor.html

--- In Homebrew_PCBs@yahoogroups.com, lists <Stuartlists@...> wrote:
>
> In article
> <40B5325EDFC7D64F83DC128117C0AD2325AD55@...>,
>    Jim Barnes <jim@...> wrote:
> > Could it be that the Liquid Tin-coated pad is less solderable than bare
> > copper?
> 
I've found the same thing so stopped using it. On small boards, I just hand tin with solder or solder paste. It's not the prettiest but it protects the copper and provides solderability.
Tuck

Sounds like you don't have all the resist removed.

Bruce


--- In Homebrew_PCBs@yahoogroups.com, "Jim Barnes" <jim@...> wrote:

>
> Hi,
> 
>  
> 
> Having gotten beyond toner transfer and etching (more below), I'm
> finally assembling my very first board. I find that it's harder to
> solder than other PCBs I've purchased. The solder pools on the wire or
> pin and doesn't easily attach to the pad. I expect the solder to "suck
> up" when the area is hot enough, but it doesn't. 
> 
>  
> 
> Could it be that the Liquid Tin-coated pad is less solderable than bare
> copper? Could it be the lack of plated-through holes that prevent it
> from "sucking up?" Must I replace my elderly (though good at all other
> jobs) temperature-controlled Ungar soldering iron? Could it be that I
> need a new tip, even though it looks perfect? I'll try using liquid flux
> next, but any advice is appreciated. 
> 
>  
> 
> Regarding etching, I used Pulsar's sponge method. It worked very well,
> though it took a bit longer than claimed. Afterward, though, I would up
> with a black, extremely filthy sponge. According to an article I earlier
> uploaded, Sodium Hydroxide (NaOH) is supposed to neutralize FeCl3,
> producing salt water and a non-toxic precipitate. Well, I tried to find
> Sodium Hydroxide. A pool store and a hardware store never heard of it.
> (Maybe I should have asked for lye or caustic soda instead.) I thought
> manufacturers were supposed to list ingredients, but that apparently
> doesn't apply to drain cleaners. I finally bought Drano Kitchen
> Crystals; at least they warned against misuse of Sodium Hydroxide.
> 
>  
> 
> Sooo, I added enough water to cover the sponge in my (fortunately)
> disposable plastic leftover tray - about 14 oz --  and poured in an
> (eyeballed) tablespoon of Kitchen Crystals. I wound up with a brown mess
> with brown things floating in it. Frankly, it looked like diarrhea! Can
> anyone hazard a guess at what this stuff is? Without knowing what it is,
> I don't want to put it in my toilet; I don't need a plumbing bill! Our
> storm drains around here drain to the ocean and I'd rather not kill any
> fish I don't have to. Right now, I'm planning to hold it, sponge
> included, until our next HazMat collection day and let the county handle
> it. 
> 
>  
> 
> For the future, how should I clean up after etching? Should I just
> figure on killing a sponge for every job? Would re-using the same filthy
> sponge for several jobs be ok before giving it to HazMat? I'm thinking
> of using Pulsar's "Baggie" alternative to the sponge method next time.
> Has anyone tried this? Does it work well?
> 
>  
> 
> Jim
> 
>  
> 
> 
> 
> [Non-text portions of this message have been removed]
>

--- In Homebrew_PCBs@yahoogroups.com, "ikc46118" <bruce.bowman@...> wrote:
>
> Sounds like you don't have all the resist removed.
> 
> Bruce


The resist will not prevent being able to solder the board.  I don't remove the resist before soldering, I using positive resist.

A long time ago I used the Tin, if I soldered the board soon after the Tinning process it soldered fine but if I did not solder it soon after the Tinning I had problems with solderability.

I decided it really was not needed to Tin the board, at first would leave the resist on the board till I was ready to load the board, then to protect the copper I spray it with clear Laquer.  Now I do not clean off the resist, load and solder the board then seal it with the clear laquer.

Ben

sailingto wrote:
> IPA = Isopropyl Alcohol...  I think anyway.  Doesn't do much for
> cutting my HP toner.  After wiping good with acetone my board solder
> nicely - just be sure to use flux.

Chemtronics "Flux-Off No-Clean Plus". Part number ES896BE. Farnell part 
number 7922493, though I'd bet my bottom dollar DigiKey, Jameco or 
Mouser stock it too.

It's basically a highly concentrated hydrocarbon solvent -- acetone, 
"hydrocarbons, C>=5, C5-6 rich" (whatever that means), a bit of CO2 and 
a few drops of methanol. Strips photoresist and solder flux like there's 
no tomorrow. Works even quicker if you use the (included) scrubbing 
brush, or a cheap toothbrush. Also doubles as paint stripper, as I found 
out to my cost... (hint: don't try and clean a PCB while it's locked in 
a Panavise). Ah well, it's a cast-alu base so it shouldn't rust or 
corrode (he says!)

It eats some plastics though, so don't use it near trimpots or 
displays... For that sort of thing, ES7208BI (Flux-Off CZ) is probably a 
better choice, but is basically unobtainable (it's been out of stock at 
Farnell for weeks).

For something less "active", Seno do a few boot-polish style roll-on PCB 
chemicals. There's a photoresist developer (which works REALLY well), a 
photoresist stripper, and a flux dispenser. I use all three -- saves 
mixing photoresist developer and such. To put it simply, I'm lazy :)

Cheers,
-- 
Phil.
ygroups@...
http://www.philpem.me.uk/