Originally Posted by Drools  Good points Jay, I'm still learning.
I forgot the trace to the ground on pin 22 of the chip. I switched out the 0201 package for 0402, yes I was hoping to solder these by hand or make a reflow hotplate to do the job. |
Do you have any of these parts to see how truly small they are? Were you going to mill a solder mask or try to squirt some dabs from a syringe?
http://en.wikipedia.org/wiki/Surface-mount_technology
0201 (0603 metric) : 0.024" × 0.012" (0.6 mm × 0.3 mm)
0402 (1005 metric) : 0.04" × 0.02" (1.0 mm × 0.5 mm)
Keep in mind your traces are .016" and that's pretty small. Might be a better idea to scale up to 603 to start with.
http://nerdfever.com/wp-content/uplo...ch-o-meter.png I could space a little further apart, the traces going up the right hand side. I must have deleted the box outline by mistake, I'm a noob on Eagle. I wish I had a tool to drill the holes, I was supposed to get one but nothing materialized as of yet. |
I use the Wolfgang to drill holes. You just need the PCB bits. But you don't want to have to stock a bunch of different ones, and if you are going to be adding vias by hand, you don't need the holes any bigger than 30ga wireor whatever you decide to use.
I still need to find or make a DC POWER JACK for the board. I need a R/A(right angle) Barrel type one that I can purchase from DigiKey and has a Eagle counterpart. I did some preliminary checking but did not find a Eagle library part that matched any of the Digikey parts. I have to check the total power requirements on the chips I'm using, I might just be able to run the board off USB power alone. |
http://www.sparkfun.com/commerce/pro...roducts_id=119 Making a part is easy. Just follow the sparkfun tutorial.
The circuit has already been running for a few weeks on my bread board at home, it is a replacement for a parallel port interface with some special code running on the uC. |
Well, you can also try shrinking the signal lines to 12mils if you think your machine will do it. I try not to get the parallel wires any closer than 8mil worst case, and I do my best to keep them as far apart as I can.