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Electronics => Beginners => Topic started by: LoveLaika on September 24, 2020, 01:36:32 pm

Title: Would an exposed pad cause issues?
Post by: LoveLaika on September 24, 2020, 01:36:32 pm
I have a mundane question that I wanted to ask. I guess I'm just paranoid, but I wanted to ask.

Say I have a diode, and one pad of my diode (surface mount) is connected to a trace that is part of a feedback loop for an op-amp. An example would be in my schematic. See how the diode has one end connected to the inverting input? Now, say I lay out my board with every intention of using that diode, but I decide to make a version where it isn't populated and the pad just lays there exposed for the sake of science. Would that exposed pad cause any issues, like act as an opening for noise and unwanted signals to pass through?
Title: Re: Would an exposed pad cause issues?
Post by: Paul Rose on September 24, 2020, 02:30:05 pm
No problem at all.
Title: Re: Would an exposed pad cause issues?
Post by: LoveLaika on September 24, 2020, 02:54:47 pm
Thanks. I guess I'm just very paranoid about stuff like that acting as like an antenna or something
Title: Re: Would an exposed pad cause issues?
Post by: Paul Rose on September 24, 2020, 11:28:06 pm
The pad would only be covered by soldermask (or a at best layer of fiberglass on a multi-layer board).
Neither of those are providing any shielding anyway.

The only risk (not worth worrying about) would be of physical contact with something metal, but there is plenty of that with exposed pins, etc. anyway.
Title: Re: Would an exposed pad cause issues?
Post by: tooki on September 26, 2020, 12:56:15 pm
I have a mundane question that I wanted to ask. I guess I'm just paranoid, but I wanted to ask.

Say I have a diode, and one pad of my diode (surface mount) is connected to a trace that is part of a feedback loop for an op-amp. An example would be in my schematic. See how the diode has one end connected to the inverting input? Now, say I lay out my board with every intention of using that diode, but I decide to make a version where it isn't populated and the pad just lays there exposed for the sake of science. Would that exposed pad cause any issues, like act as an opening for noise and unwanted signals to pass through?
Unpopulated component pads are an everyday thing in electronics. Open up a random piece of electronics and there’s a decent chance of finding unpopulated components, be it from capacitors not found to be needed, or pads for configuration resistors, or in boards used in multiple product models, where entire sections of board may be left unpopulated in some configurations.