SMD agony

Discuss PIC and electronic related things

Moderators: David Barker, Jerry Messina

Francis
Registered User
Registered User
Posts: 314
Joined: Sun Mar 25, 2007 9:40 am
Location: Devon

SMD agony

Post by Francis » Wed Jan 20, 2010 1:53 pm

Plopping solder paste is painful when you have half a dozen prototypes to make.

I was wondering about a DIY stencil and squeegying the paste.
I see that MEGA UK have brass sheet with photo-resist on both sides.
Theoretically, I could make a stencil using the usual develop+etch methods.
Then squeegy the paste through the holes.
Any better ideas?

I mean better (+ low cost) ideas :)

Raistlin
Registered User
Registered User
Posts: 69
Joined: Tue Apr 01, 2008 1:13 pm

Post by Raistlin » Wed Jan 20, 2010 4:43 pm

You could also use a Mylar laser cut stencil and solder paste :).
If you can read this you are too close

Francis
Registered User
Registered User
Posts: 314
Joined: Sun Mar 25, 2007 9:40 am
Location: Devon

Post by Francis » Wed Jan 20, 2010 4:55 pm

Haha... yes, I could.
Sadly, my keyring laser won't cut and my wallet has shrivelled up in the cold. :lol:

richardb
Posts: 306
Joined: Tue Oct 03, 2006 8:54 pm

Post by richardb » Wed Jan 20, 2010 5:11 pm

pcbpool do free sencil's when you order a pcb
Hmmm..

rmteo
Posts: 237
Joined: Fri Feb 29, 2008 7:02 pm
Location: Colorado, USA

Post by rmteo » Wed Jan 20, 2010 5:21 pm

There is a member here by the name of Ryan who does stencils http://www.ohararp.com/Stencils.html

Jon Chandler
Registered User
Registered User
Posts: 185
Joined: Mon Mar 10, 2008 8:20 am
Location: Seattle, WA USA
Contact:

Post by Jon Chandler » Wed Jan 20, 2010 7:06 pm

Look in Nuts&Volts...there are several companies offering $25 stencils. It wouldn't have to save you much grief to be worth the cost.



Jon

Francis
Registered User
Registered User
Posts: 314
Joined: Sun Mar 25, 2007 9:40 am
Location: Devon

Post by Francis » Wed Jan 20, 2010 7:37 pm

Thanks Gents.
I had a look at the Prototype costs at PCBPOOL.
I could see a Free desolder sucker but no stencil. I'll look further.

Thanks for the other advice.
Note, I'm in UK so delivery time is an issue too.
In my enthusiasm I order a bit of this brass sheet.
Should be in my mitts by tomorrow.
I'll give it a go ... and if (when?) it goes pants I'll get the proper boys to do it :)

Raistlin
Registered User
Registered User
Posts: 69
Joined: Tue Apr 01, 2008 1:13 pm

Post by Raistlin » Thu Jan 21, 2010 10:24 am

Let me know how it pans out with the brass sheet.
If you get stuck gimme a shout my laser WILL cut stencils, infact thats all it gets used for most of the time :D

I'm in the UK too.
Me and Ryan have the same laser system , although his is a bit more powerfull and bigger than mine.

Its size that counts :oops: hehe
If you can read this you are too close

Francis
Registered User
Registered User
Posts: 314
Joined: Sun Mar 25, 2007 9:40 am
Location: Devon

Post by Francis » Thu Jan 21, 2010 10:49 am

That's very kind.
I'm sitting behind the frnt door waiting for Delivery Man.

Yes, size is important ... as is the amount of thrust.

Francis
Registered User
Registered User
Posts: 314
Joined: Sun Mar 25, 2007 9:40 am
Location: Devon

Post by Francis » Thu Jan 21, 2010 8:11 pm

Sheet arrived. Stencil made.
Not brilliant, could do better.
But, yes it worked. I have done my first squeedgee and solder.
Was it worth the hassle?
In terms of £/hour charge rates + materials cost I doubt it. But it does mean I can make one on a Sunday morning after Church.
If I had a hot spray etcher it may have even taken less than 30 minutes.

(And by 'eck it's less frustrating than squeezing/splodging paste onto pads - esp when the damned stuff refuses to stick even though I warmed it up)

Raistlin , please can you post or PM me how much you'd charge.
Is cost based on 'per sq Inch'? (So I can do a ballpark cost calc)
I take it you use that expensive plastic stuff?
Can you do straight from gerbers? Rough time scales?
Method of payment? Gold, blood, cash , cheque or flesh? I haven't got Paypal.

richardb
Posts: 306
Joined: Tue Oct 03, 2006 8:54 pm

Post by richardb » Thu Jan 21, 2010 9:32 pm

well you have to buy a pcb to get the free stencil

http://www.pcb-pool.com/ppuk/order_prod ... js.html#00

fill in the size, quantity, layers and at the bottom theres a checkbox for your free stencils
i use them a lot for pcb's as they take eagle files directly so theres no messing with gerber generation.
Hmmm..

Francis
Registered User
Registered User
Posts: 314
Joined: Sun Mar 25, 2007 9:40 am
Location: Devon

Post by Francis » Thu Jan 21, 2010 9:45 pm

Thanks Richard, I didn't see that.

(I'd have to use gerber. I'm an Easy-PC/Seetrax person.. not an Eagler).

richardb
Posts: 306
Joined: Tue Oct 03, 2006 8:54 pm

Post by richardb » Thu Jan 21, 2010 10:27 pm

have a look again there is easy-pc in the file format dropdown menu

:)
Hmmm..

Francis
Registered User
Registered User
Posts: 314
Joined: Sun Mar 25, 2007 9:40 am
Location: Devon

Post by Francis » Thu Jan 21, 2010 10:39 pm

Actually, I think first I'd better buy some nice new Specs to replace my Ebay ones :)
Thanks for that.

User avatar
ohararp
Posts: 194
Joined: Tue Oct 03, 2006 11:29 pm
Location: Dayton, OH USA
Contact:

Post by ohararp » Sat Jan 23, 2010 2:55 pm

Francis, you absolutely need to try a kapton stencil. I bought a laser so that others could make use of this technology on their prototype projects. If you cover shipping I will cut you a stencil for free. Otherwise, raistlin or maverick (PDS forum) can cut you a stencil as well.
Thanks Ryan
$25 SMT Stencils!!!
www.ohararp.com/Stencils.html

Post Reply