N3ZI DDS VFO
Surface Mount Solder information page.


Many homebrewers are frightened by Surface mount technology.  The fact its that this technology is taking over the industry, but was designed for machine, not human, soldering.  I was hesitant to try, but you have no choice when if come to a DDS, the chips are only available in surface mount.  In order to keep the task as simple as possible, I decided to not to make anything else on the board surface mount.  And I chose an Analog Devices DDS chip that I felt was easiest to hand solder.  It's a 16 PIN part, most of the other DDS chips that are being used have much higher pin count.  And as it turns out, it's just not that hard.  I used my cheap, well used, Radio Shack 15w soldering iron.  I did sharpen the tip a bit with my dremmel tool.  I didn't buy special solder, I used 032 60/40 kester solder.  No extra flux.  I did use solder wick.  I also have one of those nice magnifying lamps with a circular fluorescent bulb, and a big magnifying lens in the middle.  You will need some magnification.  I also have a pair of prescription glasses that have an extreme close-up lens.  I got these at Zenni optical which sells prescription eyeglasses for $8 per pair.

CLose upCarefully align the chip in the right location. Make note of the direction. Pin 1 goes in the lower right. Pin1 on the chip has a dot indent in the plastic package. Also take a look at the photo. Align the leads on the pads and make sure it's centered left to right. Solder one of the corner pins. Re-align the chip, and solder the opposite corner pin. Solder all the remaining pins, don't worry too much about solder bridging. After you are done use solder wick to remove excess solder and any solder bridges. Inspect it carefully by eye under a magnifying glass. You can use your continuity tester to make sure there are no pin to pin shorts, and all the connections are made but testing right as the lead exits the package, then on the PCB at the appropriate point.

Now the professionals will caution you to buy a nice adjustable soldering iron with a fine tip.  And very fine solder with a different mix, and extra flux.  All of this is probably a good idea.  With my first prototype I got parts for 3, and fully expected to damage 2 before I got one right.  I tried the first one with the tools I had on hand, but planned to order the fancy stuff.  But as it turned out it was pretty easy, and I never bothered to order the fancy stuff.

If you search the web, and even YouTube, you will find lots of info about people who hand solder surface mount parts.  Not just hams, but robotics hobbyists, and many others.  And in most other cases people are hand soldering many more parts per board, and parts with higher pin count.  My PCB's are top quality professionally made boards, lead free with solder mask.  You can solder to them with lead or lead free solder.

Or if you don't want to tackle it, WA6OUW's Kit Builders will solder your TSSOP down for $10.

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