UV/heat curable solder paste

[MacGyverS2000]

I'm looking for a single component solder paste (no two-parts, please) for prototype work with SMDs...I'm assuming the next best thing to two-part systems would be either UV or heat curable. Can anyone suggest brands, purchase locations, etc.

Thanks!

 

[nbucska]

try

http://www.highspeedpc.com/Merchant...SPC&Product_Code=SilverPaint&Category_Code=OC

or search <

http://www.dogpile.com>

<nbucska@pcperipherals.com>

 

[ScottyUK]

Suggest you approach Multicore Solders for assistance.

http://www.multicore.com

 

[nbucska]

You may use ZEBRA connector, too.( conductive plastic
strips alternating with non-conductive ones)

<nbucska@pcperipherals.com>

 

[MacGyverS2000]

nb, I've seen the Zebra connectors many times in the past but never knew they had a name...not what I need for this, but cool nonetheless. The silver paint, however, looks like it would be a great candidate...decent cure time of 3-10 minutes, no heat/UV needed, priced within prototype range. Unless I find something better, I'll probably go with a bottle of that.


Scotty, I'll keep the LocTite stuff in mind as projects size requires it. For the moment, having a shelf life measured in months and at freezing storage temps for single-component glues makes it more of a pain than it's worth.


If anyone else has any more ideas, I'm all ears...

 

[cbarn24050]

Hi, if you just want to solder smts to a board you can just use an iron. Conductive paint will leave you with a fragile joint, and very likely shorts all over the board.

 

[lyallst]

I spent a few years operating a high speed SMT assembly line. we used Kester solder paste. this was reflowed in a conveyor oven. If you are working with a relatively small number of solder joints the iron and solid solder is the way to go. The reason we used a paste was process related. The paste was aplied to the PCB via a screening machine (squeegie and metal stencil). older machines used glue to place the components and the PCB with glued components was passed through a solder fontain. all these processes are geared towards volume production. In the end a solder joint is a solder joint.

 

[zeitghost]

Weller TCP with PTAA or PTP and 26gauge or thinner solder.

Works for me.

Takes a bit of practice though, specially on QFPs (above 100 pins or so) or SSOP packages.

A magnifying illuminator helps too, specially as you get towards 50 and the old eyes get longer and longer sighted.


rgds
Zeit.

 

[nbucska]

Hi Mac:
What kind of frequency ? Can't you use socket and through-
hole discretes?

Do you need to build it in final size?

HAPPY NEW YEAR !!

<nbucska@pcperipherals.com>

 

[MacGyverS2000]

Hmmm, just noticed my reply from a day or two ago never apeared here

I consider myself an accomplished solderman, so that's not the issue. The components are going onto a flexible substrate that for prototype purposes only needs to last a few weeks/months while I dink around with new ideas and placement. Not sure how well the silver paint will hold up to flexing in the lab, but if it holds on for a few weeks I'd be satisfied.

Obviously production units would use a higher strength resin, but mixing stuff up for a few components is more of a pain then I would like. In an ideal world, I would like a single component gel in a syringe that would cure with UV/low heat in a few minutes and do NOT require freezing temps for storage. That way I could keep the stuff sitting on my bench and use as needed without running to the freezer each time.

 

[ScottyUK]

Mac G,

Whatever you else you do, do not use a cyanoacylate type adhesive for this application. The adhesive decomposes at soldering temperature to give acrid choking fumes which burn your eyes. I seem to remember it is an isocyanate gas, but I'm not a chemist so I might be wrong.

I found out about this particular problem after a colleague glued down a circuit board track which had lifted during repair, which he then soldered. A lesson learned the hard way for him and the three other engineers present.