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Topic: Please help with my custom ATMega328 PCB (Read 263 times) previous topic - next topic

skaman82net

#15
Dec 06, 2018, 03:07 am Last Edit: Dec 06, 2018, 03:11 am by skaman82net
Sparks on the chip leads? Sounds like a soldering paste issue.

Please explain your process attaching the atMega328. Solder paste and a stencil? Hot air reflow? Soldering iron? Please explain in detail. Is board being cleaned post reflow? How?
I am soldering with a soldering iron and with flux liquid. The liquid disappearing while soldering. Not doing anything after that. Just checking for a short between VCC und GND and visual inspection.

EDIT: the tiny sparks I am seeing are at the top, just before the plastic housing begins

skaman82net

No bridging, everything looking fine

skaman82net

Okay! I started fresh today. New PCB, new ATmega AND a new USBtinyISP adapter. Cleaned everything after soldering and checked for shorts. Viola -flashing was no problem!!! Well, not quite - it only works if I solder the RESET wire from the USBAdapter directly on the 10k resistor - not through the JST-SH pin header (C2 bridged). But I am pretty happy right now :) It is the first board of about 6 (failed) that is finally working.

larryd

#18
Dec 06, 2018, 05:49 pm Last Edit: Dec 06, 2018, 05:50 pm by larryd
The sparks on the previous PCB still needs to be looked in to.

After solder the connections, always clean with IPA on a Q tip.




No technical PMs.
The last thing you did is where you should start looking.

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