Homebrew PCBs

Hey guys, I found this group a few days ago and really like it.  it
seems to be a little difficult to navigate through since I am used to
a "Forum Layout"  

I have been doing the TTS system from pulsar for a while now with
great success, but now i want to start tinning and doing some surface
mount.

I have a few questions for you all, that i have searched on but found
numerous different topics with no real answer..

1.  Where is the best place to get some solder paste and a fine needle
syringe for smt components.  And do you thnk I should make a reflow
oven or just use a hot air solder station to mount components.

2.  As far as tinning goes, what seems to be the best bang for the
buck?  Tinnit, Cool-amp, or solder paste reflow.  What kind of solder
paste do you use for tinning and where do I get it?  Also what do you
reflow it with?  Heat gun, or oven?


Thanks for the help
Craig
http://www.scholleco.com/phpbb/

On Fri, 02 Dec 2005 22:42:23 +0100, shollzc <shollz@...> wrote:

> Hey guys, I found this group a few days ago and really like it.  it
>
> seems to be a little difficult to navigate through since I am used to
>
> a "Forum Layout"


I reckon most use it as a mailgroup, the web interface sucks...

> 1.  Where is the best place to get some solder paste and a fine needle
>
> syringe for smt components.  And do you thnk I should make a reflow
>
> oven or just use a hot air solder station to mount components.

The needle isn't actually fine, it's rather large, and ideally short.
Not easy to find those tips actually, but often the come with the syringe  
with paste. Luer taper plastic pipette tips work too, they are conical in  
shape not a steel tube, and much cheaper and easier to get.

Hot air is fine. A oven will be better for small series and very regular  
work, so you can just pop it in and not think about it. But for the odd  
board now and then hot air is OK.


> 2.  As far as tinning goes, what seems to be the best bang for the
>
> buck?  Tinnit, Cool-amp, or solder paste reflow.  What kind of solder
>
> paste do you use for tinning and where do I get it?  Also what do you
>
> reflow it with?  Heat gun, or oven?

Plumbing solder paste seems to me the most reasonable at the moment. It's  
cheaper than SMD paste (doesn't work for SMD). You get it at shops where  
you buy tools to solder copper plumbing, like DIY or tools stores. Both  
hot air and oven works.


ST

http://www.stencilsunlimited.com/solder_products.php

$16 for a syringe of leaded or no-lead. It came packed with a freezer 
stay-cold pak, but UPS ground took 8 days to cross the continental divide. 
Be sure to mention that and ask for shipping options.

Stir-fry boards in a skillet on the gas range. (Actually, no stirring. Just 
let them sit.) Medium flame uncovered hits reflow in just over 3 minutes, 
about right on profile. Cover it when the last bit of gray turns to silver, 
count to ten then turn off the flame. Let sit for a minute before uncovering 
to cool. Let it cool undisturbed until you can pick it up by hand. Over 
cooking slightly is better than under cooking. I think it's safe to do it 
this way; even big ceramic SMT caps, my biggest worry, survive this 
treatment just fine.

Some of the guys are using plumber's solder paste to tin the board. An 
improvement over Tinnit, which I'm using.

Electroplating is still the best way to tin. I don't think anyone here is 
doing it. Read up on it at www.thinktink.com. I think I'll try it after 
using up the rest of the transfer paper. The workflow is a better fit with 
negative photo resist.

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

From: "shollzc" <shollz@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Friday, December 02, 2005 3:42 PM
Subject: [Homebrew_PCBs] Solder Paste and Tinning Questions!

> I have been doing the TTS system from pulsar for a while now with
> great success, but now i want to start tinning and doing some surface
> mount.
>
> I have a few questions for you all, that i have searched on but found
> numerous different topics with no real answer..
>
> 1.  Where is the best place to get some solder paste and a fine needle
> syringe for smt components.  And do you thnk I should make a reflow
> oven or just use a hot air solder station to mount components.
>
> 2.  As far as tinning goes, what seems to be the best bang for the
> buck?  Tinnit, Cool-amp, or solder paste reflow.  What kind of solder
> paste do you use for tinning and where do I get it?  Also what do you
> reflow it with?  Heat gun, or oven?
>
>
> Thanks for the help
> Craig
> http://www.scholleco.com/phpbb/
>
>
>
>
>
>
>
>
>
> Be sure to visit the group home and check for new Links, Files, and 
> Photos:
> http://groups.yahoo.com/group/Homebrew_PCBs
>
> If Files or Photos are running short of space, post them here:
> http://groups.yahoo.com/group/Homebrew_PCBs_Archives/
> Yahoo! Groups Links
>
>
>
>
>
>

>Electroplating is still the best way to tin. I don't think anyone here is 
>doing it. Read up on it at www.thinktink.com. I think I'll try it after 
>using up the rest of the transfer paper. The workflow is a better fit with 
>negative photo resist.
>
>  
>
  Which trace are you going to tin with electroplating?  Most want the 
whole board tinned, without having to connect each trace seperately.  It 
can be done, it's how they do gold plating for LCD boards etc, but it is 
10x the PITA you're giving it credit for..  There are some good reasons 
board houses do this step chemically, and cold plating solutions like 
tinnit exist..  By all means try it out though, electroplating is 
interesting and fun for other things anyway..

Alan

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

From: "Alan King" <alan@...>


>
>>Electroplating is still the best way to tin. I don't think anyone here is
>>doing it. Read up on it at www.thinktink.com. I think I'll try it after
>>using up the rest of the transfer paper. The workflow is a better fit with
>>negative photo resist.
>>
>  Which trace are you going to tin with electroplating?  Most want the
> whole board tinned, without having to connect each trace seperately.  It
> can be done, it's how they do gold plating for LCD boards etc, but it is
> 10x the PITA you're giving it credit for..  There are some good reasons
> board houses do this step chemically, and cold plating solutions like
> tinnit exist..  By all means try it out though, electroplating is
> interesting and fun for other things anyway..

I'm really more interested in plating the holes, not just plating for 
plating's sake. Plating tin or solder in addition to plating copper wouldn't 
be much more complicated than just a setup for copper alone.

All the traces, Alan. Drill the board. Plate with copper, including and 
especially the holes. Laminate with negative resist. Print the positive 
image onto the resist. Develop. Since the image is reversed, this exposes 
what will become the traces and leaves the etch area still covered. Plate 
with tin or solder. The cladding underneath the resist is still intact and 
conducts plating current to all areas, including and especially the holes. 
The resist prevents the etch areas from plating. Strip the resist. The tin 
plating is now the etch resist. Etch. The unplated areas are removed. In my 
mind's eye of an idyllic world, this leaves bright tin traces and conductive 
plated through holes, gleaming in the ethereal glare of an ideally lit 
workroom. (I work by the single bare bulb of the dismally painted darkroom.)

The idea isn't so much that I like plating for plating's sake. I am so 
completely tired of laying out around and probing and fixing the iffy top 
connections hidden underneath components. Reflow isn't completely effective 
with unconductive holes. I spent an hour yesterday reworking a single pin on 
a shrouded header. I reflowed it a few times with as much paste as I could 
shove under the header, before finally giving up and jumpering it with Kynar 
wire.

BTW, kudos to whoever mentioned the Weller Portasol recently. I dug mine out 
of semi retirement to reflow a few other incompletely reflowed parts. 
Slightly over cooked is vastly better than even a little under cooked. It 
(the Portasol) works great, and heats things up in a big hurry.

--- In Homebrew_PCBs@yahoogroups.com, "shollzc" <shollz@g...> wrote:
>
> Hey guys, I found this group a few days ago and really like it.  it
> seems to be a little difficult to navigate through since I am used 
to
> a "Forum Layout"  
> 
> I have been doing the TTS system from pulsar for a while now with
> great success, but now i want to start tinning and doing some 
surface
> mount.
> 
> I have a few questions for you all, that i have searched on but 
found
> numerous different topics with no real answer..
> 
> 1.  Where is the best place to get some solder paste and a fine 
needle
> syringe for smt components.  And do you thnk I should make a reflow
> oven or just use a hot air solder station to mount components.
> 
> 2.  As far as tinning goes, what seems to be the best bang for the
> buck?  Tinnit, Cool-amp, or solder paste reflow.  What kind of 
solder
> paste do you use for tinning and where do I get it?  Also what do 
you
> reflow it with?  Heat gun, or oven?
> 
> 
> Thanks for the help
> Craig
> http://www.scholleco.com/phpbb/
>


as far as tinnig goes read message 10103, should work for you.

mebo

Mike Young wrote:

>I'm really more interested in plating the holes, not just plating for 
>plating's sake. Plating tin or solder in addition to plating copper wouldn't 
>be much more complicated than just a setup for copper alone.
>
>All the traces, Alan. Drill the board. Plate with copper, including and 
>  
>
  Got the method, the write up is pretty good too.  But most things I've 
seen on it describe it as a little more problematic than the write up, 
so I hope you have good luck as well..

Alan