big boo boo on PCboards traces between smd pads

AnalogKid

Well-Known Member

Most Helpful Member

• Oct 20, 2023

• #2

Bare board or Gerber image of the offending layer - ?

ak

 

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Tony Stewart

Well-Known Member

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• Oct 20, 2023

• #3

no solder mask?

 

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P

Pommie

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• Oct 20, 2023

• #4

Are these home made boards without solder resist?

Mike.

 

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MrDEB

Well-Known Member

• Oct 26, 2023

• #5

Yes, these are JLCPCB boards.
Before I went any further I tested the code again and found an issue. Corrected. I am still working on code but different issues.

 

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T

tumbleweed

Well-Known Member

Most Helpful Member

• Oct 26, 2023

• #6

What problems are you having with the code?
I didn't really test it so there could well be issues with it, but I'd like to know what they are so I don't make that mistake again.

 

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F

For The Popcorn

Well-Known Member

Most Helpful Member

• Oct 26, 2023

• #7

MrDEB said:

Yes, these are JLCPCB boards.

Click to expand...

You would really have to work to get boards without soldermask. Soldermask is the green/red/blue/etc. layer on the boards.

But I have to wonder how you mistakenly routed traces between resistor pads too.

 

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P

Pommie

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Most Helpful Member

• Oct 28, 2023

• #8

Yup, looks very suspicious, I've had boards made by JLC and never had problems. Please explain.

Mike.

 

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Nigel Goodwin

Super Moderator

Most Helpful Member

• Oct 28, 2023

• #9

Pommie said:

Yup, looks very suspicious, I've had boards made by JLC and never had problems. Please explain.

Mike.

Click to expand...

No doubt is like all of his threads, a completely random 'design' without checking anything or knowing what he's doing

 

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MrDEB

Well-Known Member

• Nov 2, 2023

• #10

it was testing some new boards and discovered the trace under the resistor. It apparently was not the issue.
edited my code and after testing the portb pullups, leds and matrix I now have a working code that performs better than expected.
I was using the wrong ports for the matrix (had wrong order portC instead of portD
ALL IS GOOD NOW

 

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DerStrom8

Super Moderator

• Nov 10, 2023

• #11

I realize the trace under the components wasn't the issue in this case, but it is still bad practice. I personally avoid routing between SMD resistor pads (especially on smaller packages) because it is very easy for soldermask to scrape off slightly and make contact with conductive parts of the component. The only time I route under passives is if they are in a very large package and I am sure there is nothing conductive on the part. Even then, though, I use it as a last resort and prefer to route around the part instead.

 

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