Surface Mount PCB construction

jetstuff · Post by **jetstuff** » Tue Jun 17, 2008 1:28 pm

my V4 kit just arrived today (UK)..... looks good so far....THANKS!

A method of construction that I have used in the past and will do this time: Use a sprung wooden 'clothes peg' (from the wifes washing basket) with a piece of springy 'piano wire' (from the local model - hobby shop). If the wire is bent as shown and glued into a small hole drilled into the top leg....and the bottom leg of the peg is screwed to the bench top...it can be used to hold down the components, whilst leaving both hands free to solder in place. Adjust the tension by bending the wire ...not too tight....not too loose.

john

steve_c · Post by **steve_c** » Tue Jun 17, 2008 2:16 pm

I'm building boards like this fairly frequently. I put a small amount of solder on one pad (before offering up the component). Then using tweezers, offer up the component and melt the solder on the pad underneath the component terminal. This holds the component enough to solder the other end then you can go back and ensure a good joint on the first pad. You need a fine tipped iron and good eyesight. We have a pick and place machine to build our production boards, but prototypes are built by hand. This board uses 1206 sized components. Try working with 0603 (half the size) or 0402 (even smaller)!

Steve

Post by **brentp** » Tue Jun 17, 2008 4:28 pm

Thank you for sharing. May I use your picture for the documentation?

The method we suggest in our documentation (rev limiter, MJLJ v4) is as steve describes: put a small amout of solder on one pad (one pad only! ). melt the blob and slide the part into place. solder the other component pins and retouch the original pad, if needed.

jetstuff · Post by **jetstuff** » Tue Jun 17, 2008 6:59 pm

Yes of course Brent if they are of use to you..... I like the 'clothes peg' method as it allows you to get the components nicely squared up without having to rush and overheat them. I think I prefer making surface mount boards now rather than using wire ended components....it certainly shouldn't put anyone off building from the kit if they've done some fine soldering before.

john

capri_turbo · Post by **capri_turbo** » Thu Jun 26, 2008 8:52 pm

I'm with steve c on this one. We do a huge amount of surface mount at work. Most is on the pick and place machine, but a lot is hand placed onto pasted for reflow, and the stuff that isn't, is done by tinning one pad, reflowing with the iron to locate one end of the component and then soldering the other end. This is the method recommended by training organisations such as "Electronics Yorkshire" etc.

I actually run the Surface Mount pick and place machine (Quad QSV-1) on a daily basis and do a little hand soldering too. The larger 1206 components are easy, but as mentioned above, it becomes a little tricky with 0805 and 0402's.

jetstuff · Post by **jetstuff** » Fri Jun 27, 2008 8:06 am

My method obviously not recommended for Yorkshire Experts then..... or those with a pick and place machine in the shed.....

For the average electronic (or car) enthusiast.... you pays' your money and you make your choice

john

dr.occa · Post by **dr.occa** » Mon Jun 30, 2008 8:22 pm

love the ingenuity there jetstuff. will have to experiment with it on some upcoming projects.