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.
Carefully 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.