Does routing through a pad matter? (see images)

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jlawley1969

Joined Feb 22, 2021
93
Sorry I did not know of a better way to word that title.
But, I am curious about a simple design decision. In the first image the left component(diode)'s bottom pin is routed through the left components bottom pin. In the second image the bottom left pad and bottom right pad converge on the trace they will be sharing.

I know they are theoretically electrically the same but I am unsure of how it matters in practice. I have read some articles that mostly mention that this matters for wave soldering and one may cause more of an issue than the other. These components(diode and resistor) are attached to a MOSFET gate on the bottom side and attached to a gate driver on the top side. I am mostly concerned about issues with signal integrity but any information on this subject would be useful for me.
thank you.

ps I could obvious do the same "splitting" to the top trace but didn't think to show that as well when I was taking the photos.
 

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Deleted member 115935

Joined Dec 31, 1969
0
Personally
I'd prefer the right version,
I'm old, and still worry about the dreaded flux trap.
The track looks fairly thick, does it need to be that large,
it "could" be considered to "wick" the solder away from the pad,

But in truth, I'd not worry.
 

MrChips

Joined Oct 2, 2009
24,609
Electrically, it should not matter.
There are situations with thu-hole components when I prefer not to route through a pad. Same applies to SMD.
This would allow me to isolate a component by cutting the trace if I had some debugging and rerouting to do.

PCB routing through pads.jpg
There are those occasions when I would choose B and not A.
 

peterdeco

Joined Oct 8, 2019
413
I agree that track width seems excessive. It's almost the size of the pad itself. Unless you have through hole components on the board, the most popular soldering process for surface mount is reflow soldering. If the board has solder mask, either way should be no problem.
 

BobaMosfet

Joined Jul 1, 2009
1,896
Sorry I did not know of a better way to word that title.
But, I am curious about a simple design decision. In the first image the left component(diode)'s bottom pin is routed through the left components bottom pin. In the second image the bottom left pad and bottom right pad converge on the trace they will be sharing.

I know they are theoretically electrically the same but I am unsure of how it matters in practice. I have read some articles that mostly mention that this matters for wave soldering and one may cause more of an issue than the other. These components(diode and resistor) are attached to a MOSFET gate on the bottom side and attached to a gate driver on the top side. I am mostly concerned about issues with signal integrity but any information on this subject would be useful for me.
thank you.

ps I could obvious do the same "splitting" to the top trace but didn't think to show that as well when I was taking the photos.
To be perfectly honest, the left image causes a 'T' intersection that can cause EMF. it's better to connect to the pad on the right. While the right image has a 90-degree corner, it's better than a 'T'. IMHO.
 
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