[Gta04-owner] [Tinkerphones] Status of GTA04A5 production +++ has started +++ video available

dalo9fz at gmail.com dalo9fz at gmail.com
Sat Oct 8 08:39:27 CEST 2016


Hi Nikolaus (and others),

About the shorts on the DM3730,  i asked some profs in university about it.
Maybe i'm late.

One prof told me (rephrasing):
There are 3 things to check but considering the setup described, the
people (you) know what they are doing. It is not a bad thing to remind
them of it.
It *could* be a simple problem and not an exotic one.
Here are some things one could check to troubleshoot this problem.

1. Heat and warping:
    It could be that the board itself warps enough to have misplacement of
the chip:
    Do you have gold inlays on the traces (between solder mask)?
    if not, this could help.
    Also, the board needs to be super flat, the inlays must have the
correct height,
    or warping might take place on the board.

2. Misplacement/alignment:
    It could be that the pick and place machine needs to be calibrated a
bit,
    can you verify that the placing of the chip is exact ?
    Also it could be that the translation of the gerber messes with the
    size of traces etc..
    can you verify that the board has the exact measurments like in the
gerber?

3. Solder paste:
    Can you verify that the solder paste is distributed evenly ?
    enough paste and not too much either.
    maybe change solderpaste?


I understand that these might not really be answers you are waiting for,
but sharing is caring :)
No reply required.

Thank you so much for al your (the whole team and list) efforts.

Dalo




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