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General => General Chat => Topic started by: bjdhjy888 on September 24, 2019, 01:08:05 am

Title: Is not using a GND pour on purpose a bad habbit?
Post by: bjdhjy888 on September 24, 2019, 01:08:05 am
I know it's good to use a ground pour, but I found a PCB with no GND pour would have a clearer view of the wires on the board, thus, it would be easier for me to debug it, cutting wires or soldering flying wires.

It would be more difficult for me to do so if there were a GND pour.

Is this a good thing to do?
 ::)
Title: Re: Is not using GND pour on purpose a bad habbit?
Post by: tautech on September 24, 2019, 01:16:36 am
The type of circuit and its particular sensitivities matters however for debugging place some copper text next to the important nets and/or some SMD test points to hook probes directly to.

These fit nicely onto a 0805 footprint and you can recycle them after your prototype work is done.

(https://media.digikey.com/photos/Keystone%20Elect%20Photos/5015.jpg)

https://www.digikey.co.nz/product-detail/en/keystone-electronics/5015/36-5015CT-ND/278886 (https://www.digikey.co.nz/product-detail/en/keystone-electronics/5015/36-5015CT-ND/278886)
Buy them in bulk and sell some to friends to keep the costs down.
Title: Re: Is not using a GND pour on purpose a bad habbit?
Post by: Neilm on September 24, 2019, 06:54:50 pm
Depending on the application I have found a ground pour can cause more issues than it solves.
Title: Re: Is not using a GND pour on purpose a bad habbit?
Post by: daqq on September 24, 2019, 08:26:48 pm
Quote
I know it's good to use a ground pour,
Depends. At the end of the day it has to do with signal integrity and current return paths.

A copper pour in an internal layer is an invaluable tool for high speed design - and high speed design these days includes basic MCUs, where a rising edge can be in the few ns order.

Per rule of thumb it helps, or at least does not do harm... but.

Depending on the application, a poorly though through copper pour can even create unwanted current paths that will affect your application in a negative way.

It's simply a tool, neither good, nor bad.

Relevant reading: https://www.analog.com/en/analog-dialogue/articles/staying-well-grounded.html (https://www.analog.com/en/analog-dialogue/articles/staying-well-grounded.html)
(there are many other good texts)