Ever wondered what was inside your SD card?
The board layout is impressive. As a CID, I have to congratulate whomever was responsible - nice job!
The light pipe is interesting, but the antenna connector seems a bit redundant?
Wow!
Nice piece of engineering indeed!
Nice photography! Not sure what all that gluey stuff is on the CPU. The antenna connector is for the testing that the imps undergo on our own production line.
Peter
sjm …
Now we want to see you make one with your Weller hand-held soldering iron.
The gluey stuff on the BGA packages is underfill, to ensure better reliability in the face of mechanical stress. BGAs can be fragile, and we don’t want the imp to be.
As Peter says, the antenna connector is for testing during production. It’s a change-over connector, so when the test fixture connects to it, the antenna is disconnected allowing a good match to the Litepoint tester.
The layout was myself and the CM’s engineers in Taiwan. We went many, many rounds to get it to where it was, but I’m pretty happy with the end result!
Hugo, may I ask which PCB manufacturer did the PCBs? As far as I know, the wafer level BGA packages have a ball pitch of 0.4mm, thus the inner vias may be smaller than 0.2mm diameter…
Anyway, great job! (both hardware AND firmware AND software!!!)