Quote from: vs3 on September 19, 2013, 02:43:11 AM

Quote from: doxavg on September 19, 2013, 02:18:52 AM

Thanks for the quick reply, I think I missed something in the wording of my question. I understood (for the most part - the extra detail was much appreciated) why the heat was dissipated from the back of the board. I was looking more to understand why the traces for the USB power were on that side of the board and not on the side with the components. After actually checking the traces again, I realized that you did design your board opposite what ASICMiner did and the heat sink will actually face up when plugged in (at least on the two machines I have in front of me).

Ah ..

The board was initially designed to have the exact same physical dimensions ad BKKCoin's K1 Nano board (so that we can use the same heatsink, plastics, etc). And he had put the USB connector (tracks) on the back, so we just kept it the same. That was probably not necessary but since it didn't hurt either we just left it there and moved on.

Either way - a lot of things happened in the mean time, and with the Avalon fiasco the whole Klondike project development has grinded to a halt. We also got updated quotes for the board manufacturing, and we either have to have those those tracks gold-plated (so that they don't corrode and oxidize) or if we leave them tin-covered it is likely that after a few months to a year they may start having connectivity issues (and you'll have to clean the contacts, etc). So ... as a result in the next version of the board we're going to replace the USB connector and instead of a printed one on the board (although a bit cheaper) we're going to use a real one.

Hi,
Some info.
Generally you can ask PCB shop to cover contacts with so called "hard " gold plating in order to have this pins long lasting.
Also to if you do not use additional pad the board have to be 2 mm +/- 0.05 mm.
This is the USB connector spec