Homebrew PCBs

Looking for tutorials on toaster method of soldering smd parts.
Any advice on soldering smd parts would be appreciated.
I do not want to hand solder them!
However using hot air to solder IC's looks fairly easy, was wondering though would that work for smaller parts like smd led's and caps?
Wouldn't the air move the smaller parts?

Whats a good hot air solder station, that won't break the bank?
The toaster method sounds like the easiest, but would like to see or read a tutorial.

Hot air does not move the parts because they are held by surface
tension of the solder.

To solder single sided boards I have found the "skillet" or "hotplate"
method very convenient.

Sparkfun has good SMD tutorials, search with google for them.

ST

On Fri, Mar 16, 2012 at 5:53 PM, acidblue <sunblaster5@...> wrote:
> Looking for tutorials on toaster method of soldering smd parts.
> Any advice on soldering smd parts would be appreciated.
> I do not want to hand solder them!
> However using hot air to solder IC's looks fairly easy, was wondering though would that work for smaller parts like smd led's and caps?
> Wouldn't the air move the smaller parts?
>
> Whats a good hot air solder station, that won't break the bank?
> The toaster method sounds like the easiest, but would like to see or read a tutorial.
>

On Fri, Mar 16, 2012 at 04:53:16PM -0000, acidblue wrote:

> Wouldn't the air move the smaller parts?

It doesn't move 0603 parts at least. The solder paste will keep them
stuck in place.

One thing you do have to watch out for with small parts is "tombstoning".
The surface tension that keeps them from blowing away is not your
friend if you used too much solder paste (which is really easy to do).
What happens is your 0603 cap levitates itself vertical like a tombstone
(hence the name) if there's a bit too much solder paste on the terminals.
It's easy enough to correct (lay it back down again with tweezers while
you keep the solder molten, you only need three hands to do it) but
it will slow you down. (You need very very little solder paste, however
much you put down you'll find half the time it's still too much).

The hot plate/skillet method works great and is the cheapest and easiest if you're just doing single-sided boards.  Google search using hot plate skillet smd reflow as keywords and you'll find all kinds of info.  

I use an old skillet that I had to buy a replacement for (to cook food; how boring) because the non-stick Teflon coating was shot.  I found after measuring its temperature curve that all I had to do to come pretty close to the desired temperature profile on the upside was to place the board in the center of the skillet, turn the temp control to 450F, put the lid on to retain heat and speed up the heat rise rate, and turn it off the moment all of the solder had properly melted.  The cool-down isn't as fast as desirable according to the ideal SMD soldering temperature profile, so I remove the board from the skillet as soon as all of the solder solidifies to minimize the duration of component exposure to heat.

--- In Homebrew_PCBs@yahoogroups.com, "acidblue" <sunblaster5@...> wrote:

>
> Looking for tutorials on toaster method of soldering smd parts.
> Any advice on soldering smd parts would be appreciated.
> I do not want to hand solder them!
> However using hot air to solder IC's looks fairly easy, was wondering though would that work for smaller parts like smd led's and caps?
> Wouldn't the air move the smaller parts?
> 
> Whats a good hot air solder station, that won't break the bank?
> The toaster method sounds like the easiest, but would like to see or read a tutorial.
>

Buy a dental pick.  Knock them back down with one hand while heating the
board with the hot air.

Typically I just throw the 0603 caps/resistors with tweezers and use a
dental pick for drag positioning.  I find tweezers stick when mixed with
flux so you need to clean them constantly and the precision to place parts
is much hard than dragging them into position.

Dental pick is the way to go.

Hot air gun is much better for small prototype runs because a hot plate
gets too hot for you to put your hands/face on it with the pick or tweezers.

Henry

On Fri, Mar 16, 2012 at 10:19 AM, Dylan Smith <dyls@...> wrote:

> **
>
>
> On Fri, Mar 16, 2012 at 04:53:16PM -0000, acidblue wrote:
>
> > Wouldn't the air move the smaller parts?
>
> It doesn't move 0603 parts at least. The solder paste will keep them
> stuck in place.
>
> One thing you do have to watch out for with small parts is "tombstoning".
> The surface tension that keeps them from blowing away is not your
> friend if you used too much solder paste (which is really easy to do).
> What happens is your 0603 cap levitates itself vertical like a tombstone
> (hence the name) if there's a bit too much solder paste on the terminals.
> It's easy enough to correct (lay it back down again with tweezers while
> you keep the solder molten, you only need three hands to do it) but
> it will slow you down. (You need very very little solder paste, however
> much you put down you'll find half the time it's still too much).
>
>  
>


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