has anyone tried epboard.com? solder mask? and soldering uSOP packages?

Matthew

Just wondering if anyone has tried epboard.com, and more specifically, they're prototyping IC adapters.

They don't seem to mention if they they're boards already have solder on the connections or not (is this called solder mask)?

Also, how do I solder such small packages such as the uSOP ones? The pins have a pitch of 0.5mm!!

Thanks,
Matthew

Paul Baker

I haven't used them specifically but I have used several adapter boards, for my technique of soldering suface mount read the second to last post in this thread: http://forums.parallax.com/showthread.php?p=527876

for a video demonstrating this http://www.howardelectronics.com/navigate/videoclips.html·(its the 3rd video).

a solder mask prevents solder from leaving the pad area, some places will place a thin layer of solder on the pads, but this isn't for soldering the pins on, its to make the solder you use flow and bond quickly with the pad. I actually find that soldering .5 mm pins is easier than .85 mm pins because the pins are about twice as small and therefore heat very quickly alowing the solder to bond to the pin and pad quickly. Getting the chip lined up is the key as well as the other points in the post I refered to. To make the adapter secure when your solding the chip on it, plug it into a breadboard first.

Matthew

Thanks for the suggestion and explanation. I'm not too sure what kind of tip the film used, but do you think a standard one (those tips that come with the $6 irons) will work?

What was the liquid the person poured over the pins in the film?

Paul Baker

Flux, I really suggest getting some, the no clean kind, it makes the task much easier. As far as tips, you want one that has a flat surface on it, I use one that is much smaller than the one in the video (1.6mm wide) heres a picture of what I use http://www.howardelectronics.com/xytronic/tips.html#wavetip·but you have to get one that is compatible with your iron.

Forrest

I've used one of those soldering irons - it works well but it costs $400.

You can use a less expensive soldering iron but the key is the tip. The one used in the video is called a mini-wave tip and you can get it here www.howardelectronics.com/xytronic/tips.html

More info in this thread http://forums.parallax.com/showthread.php?p=523204

Paul Baker

Forrest: are you refering to the Xytronic 137ESD? Howard electronics (the site we've both been refering to) has tradeshow demo models for $75 and a tradeshow model of the 136ESD for $65 (New they are $100 and $90 respectively). Both Jim McCorison and Steve Joblin picked one up from them, PM them if you want personal feedback on the condition and quality.

Addendum, nevermind I see your refering to the JBC AD2700, yeah they're pricey

If I had my druthers Id get this http://www.howardelectronics.com/xytronic/988dtp.html

Post Edited (Paul Baker) : 3/7/2005 3:58:25 AM GMT

Matthew

Chucks! Those tips are expensive! And I don't even think they'll fit my iron! [noparse]:([/noparse]

I'll go over to my local electronics store and see if any of them are willing to help out a teenager [noparse]:)[/noparse].

Matthew

Well, guys, I survived! I aligned the chip, and just barely heated the pins so that they could fuse with the solder on the pads. The connections aren't the strongest ever (I was able to knock them out with a very hard flick of the inger), but they'll be good enough for my purposes. My multimeter tells me all of the connections are good and that they aren't any bridges!

Paul Baker

congrats matthew, one point is you may want to add a little to the supply pins and any connects that source or sink alot of current, it not absolutely necessary, I havent heard of joints poping from overheating, but it is within the realm of reason. One thing is with practice, it gets easier.

Matthew

Boy oh boy... I can't WAIT till summer! More time for larger projects with smaller PC boards (now that I know how to solder these tiny babies)!