SOT to TO92 Adapter PCB with extra

[zayance]

Hi There,


These are things that at first search couldn't find on the web, wich was surprising, but
after some other search i saw that Digikey provides similar things, brand called "surfboards", but i found that if sold individualy they would be tricky to solder, since SOT23 are pretty small and Some other search on google writing SOT to SIP or SOT to DIP showed me some other options already done out there, but i think all in all a little hard for those
who might be fearing SMD, so i still had fun desiging this board with some helpers on board, and some suggestions of people from here, thanks to Harpo and mikefatom

The panel would have 20x SOT-23 adapters, 12x SOT89, and 8 SOT-223 packages + Soldering template to help soldering those SMD parts + an idea of building
a small cage for the SOT23 template tool, so when the part is in place, it would be emprisoned and kept still for soldering.

One side on BCE configuration.
The other in CBE configuration (Except for SOT 223)

Legs have 0.1" Lead space

I tried to add enough adapters for a lifetime for repair, or even enough for prototyping and mods i guess.
But all in one bigger panel, wich allows better manipulations of all this with its template tool for soldering without fear of shaking.

If there is interest, please post here, still thinking to make some of these or not so....

I was thinking of a board that would cost 16Euros excl.PPfees and Shipping. (low cost priority international)
wich will makes something like 0.5Euros per adapter i guess.

Drawing from Harpo, the crossing legs won't be needed now, but i keep the idea of making a hook with the legs for better stability, and ease of soldering etc...

 

[mikefatom]

Hey zayance,

Nice idea!  These adapters can definitely come in handy for prototyping.

Few comments:

1- Wouldn't it be better to have two footprint per adapter?  One on the top side wired for CBE and the other on the bottom side for BCE.  This keeps the board small and lets the user choose whichever side they want for the pinout.

2- SOT-23's don't dissipate much through their case.  It is much more efficient to draw the heat out of the package via the leads.  That's simple enough to do with large pads and/or thermal spokes.  In my opinion, if you need as much copper as you show in the screen shot for a SOT-23, you are probably seriously abusing that part.

3- The annular rings on most of your pads look a bit on the small side.  I would increase them a bit to make soldering easier.

Also, I don't get the "jumper legs cutrer helper" thing.  Can you elaborate?

Cheers!

Mike

 

[zayance]

Hi Mike,

1- Wouldn't it be better to have two footprint per adapter?  One on the top side wired for CBE and the other on the bottom side for BCE.  This keeps the board small and lets the user choose whichever side they want for the pinout.

Yes of course it would be possible..., could be more convenient true! Thanks.

2- SOT-23's don't dissipate much through their case.  It is much more efficient to draw the heat out of the package via the leads.  That's simple enough to do with large pads and/or thermal spokes.  In my opinion, if you need as much copper as you show in the screen shot for a SOT-23, you are probably seriously abusing that part.

The package is very small, sure it will be hard for it to dissipate, and maybe you're right, the leads might be sufficient, the dissipators, were just for "incase" kind of moment,
and as i said, pretty virtual tought, i won't really be providing any thermal drawings etc... with them... haha, and was also a nice way to add some logo haha.

So basically you suggest i just trash those guetto dissipators as they won't be really needed right?

3- The annular rings on most of your pads look a bit on the small side.  I would increase them a bit to make soldering easier.

The screen capture show them pretty small as it's resized, but on printout it should be enough, but yes i can increase the ones close to the SOT packages just to be on safe side.

Also, I don't get the "jumper legs cutrer helper" thing.  Can you elaborate?

Actually nothing much, and i don't know if i had to precise, the idea is to help your cutter tool to cut the legs that would
maybe be too flush on board etc... just a detail .

Thanks for your comments, most welcome!


Best Regards,


T.

 

[mikefatom]

So basically you suggest i just trash those guetto dissipators as they won't be really needed right?

Yes.

Is the whole panel made out of 1mm thick FR4?

 

[zayance]

Yes 1mm, or 1.2mm, should be enough for these and the soldering template tool etc...

Thanks again for shimming in.

T.

 

[mikefatom]

Cool!  The template idea is interesting.  Let us know how that works out.

Cheers,

Mike

 

[zayance]

Well i think the template should work nicely, it will be easier for dealing with these i think.
Basically you screw in place by "band" and solder the packages you want etc...
I may just mod one thing for making that "grill" for SOT23 Package footprint on the tool better.
Because even if well fitted it might stick to the iron tip, so i'll makes something maybe better then the idea shown on the screen capture,
same idea but in a different way, so it may avoid any problems.

The other package are "bigger" enough to allow your finger to keep the part still.
But you don't have to worry about it sliding away then, it should keep those package tidy in there.

Might be nice for me to have an idea of any interest out there.
I will do a small run just for ending the idea, but always nice to have some feedback.


Thanks.


T.

 

[zayance]

I actually stumble across a lot of other similar things made by others, when i was searching for that
type of thing, my search was not saying "SOT to SIP adapter" or "SOT to DIP", that's why i found none at that time.
So couple of options out there already, so dunno if it's worth proposing these afterall, even if they come
in a more convenient package i think etc...
Got me thinking.....

 

[zayance]

Edited first post with finished board, will see if i makes some and provide them on my WM or not.