日本語
I have a project where I designed the front panel from PCB material, and played a bit with solder mask, tinned areas (HASL), and exposed bare PCB material to mimic the look of a vintage computer's control panel. I am quite happy with the way it looks, with one exception:
The areas to the left and right of the main keypad were originally made from whitish, translucent plastic (acrylic?). I try to approximate this look with the exposed bare PCB material. But the FR4 boards I have received from various suppliers so far are all distinctly yellow -- which does not look right, and in fact looks a bit unhealthy.
Is anybody aware of flavors of FR-4 (copper-clad, for use in PCB production) which are essentially white? Any recommendations for PCB houses which can supply and work with such material?
Thanks!
- Comments(1)
A****min
May 17.2019, 19:23:23
pure tin solder or plating plus moisture plus retained stress seems to be the recipe for the whisker formation. I saw some whiskers on a particular batch of Xilinx chips that had pure tin plating, plus the gull-wing leads were apparently formed AFTER plating. I was using a tin/lead solder, so did not heat them enough to anneal the tin plating, and whiskers grew, RIGHT at the bends, only.
I do a lot of manufacturing with SAC305 solder, and have not had any problems with those boards. That is about 1000 boards in the field, but almost all P&P and reflow, not hand soldering.
