On 3/6/21 9:37 PM, Josh Malone wrote:
On Sat, Mar 6, 2021 at 8:26 PM Stephen Adolph <[email protected]> wrote:
No I have been using paste stencil and hot air reflow. It is ok but I end up
with pins to fix up.
Okay, whew :)
I first learned to do SMD work when I built my first REX based on your
original gerbers and firmware. It was suuuuuper stressful at first,
If you're building REX Classic in quantity and getting PCBs from one of
the Chinese manufacturers, I have recently modified pcb to accommodate
the manufacturing tolerances at JLCPCB and PCBWAY.
* Minimum castellation depth 0.5mm
* Minimum drill size 0.3mm
* Minimum soldermask width 0.22mm
The updated board still fits in the existing carrier, no change to the
carrier.
There's gerbers and a shared project on PCBWAY
https://www.pcbway.com/project/shareproject/REX_Classic__BKW_re_spin.html
And github and oshpark are updated to this version as well. I have
already received a set of these from PCBWAY and actually transplanted
most of my REX's over to these boards.
I'm getting real good at desoldering, cleaning up, resoldering on a new
board. As I've made small changes to this and other boards over time, I
didn't want to keep using up new chips, but I also always want to use my
most recent boards, so instead I've been using up time and desoldering
alloy that probably ends up costing more than the chips... I think I've
transplanted some of these things 5 times or more by now! I'm kind of
suprized they still work.
I have some boards with SOIC AT28C256 on them that the markings on the
chips are completely gone. I think maybe from all the ultrasonic
cleaning after each transplant.
--
bkw
