A while ago I took an
interest in experimenting with digital pots and caps. So I ordered the MCP4018
and the NCD2400.
The package size should
prove to be a bit of a challenge, especially the NCD2400 which comes as a DFN-6.
The MCP4018 is SC-70-6 which should be ok.
While I didn’t have the
correct breakout boards for either chip, I could have made do with what I had
on hand for the 4018. But there was nothing I had on hand for the NCD2400. So,
I decided to try and see if I had the skills to etch my own breakout boards that
small.
My 1st attempt
(upper left in picture) resulted in a board that while it had no shorts, it was not suitable. The iron
was to hot and or I pressed to hard. My
2nd attempt (upper right in picture) was better, from the perspective of the board quality
and I reworked the trace sizes somewhat. The traces leading up to the IC
footprint were wider and then reduced leading to the component. The thickness there
was the same size as the pin on the chip.
However the board was still not good enough to attempt to solder the
chips in place.
My 3rd attempt
proved much better. Traces were altered further as well and I made the attempt to
solder the chips in place.
The 4018 install went
fine, a little crooked but there were no shorts and that's what counts for the moment. But, the 2400 was a different story.
I tried the tin one pad and reheat the pin and follow up with the rest method,
but after a few unsuccessful attempts the trace lifted.
I’m not sure how
exactly my next approach to solder a DFN IC will be but I’m still confident I
can do it without the use of a solder oven. I do have parts on hand to make a
solder oven but who knows if and when I’ll build it.
The MCP4018 is working well and I am experimenting with it at the moment with the UA741 opamp. That will be a posting at a later date.
