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My PCB and Commercial PCB Comparison

Hilti

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Hello Everyone,

I am really new at PCB design and edaboard.com forum. Maybe my questions would be silly if so, sorry in advance :)
1.jpeg
The PCB at the top is my design for BLDC motor control. The bottom one is a commercial product. Well, as you can see there are some differences I want to ask about them.
2.jpeg

1- The tracks and polygons of commercial pcb are brown. My pcb's tracks are green. First, I though they exposed copper and erase the solder mask but the pads of the components are silver. I guess this is a some kind of plating but I don't know. (Also, mosfets' thermal pads are brown. Mine is silver)

2- Most of the vias combines with white pads. Also, all of the vias are non- solder mask. What is the purpose of these?

3- I made most of the connections high current lines with polygons. Also, I poured ground all of the other ares but as far as I see, they did not do that (Maybe inner layers)

I am open minded for all of the corrections, advise etc, for improve myself

Thanks,

:)
 

KlausST

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Hi,

If your circuit works, then everything is O.K. No need to worry.

1) green vs brown tracks.
It does not matter. Maybe one is tin plated the other is pure copper.

2) solder mask on vias vs not..
There may be a problem when aggressive chemical residuals are enclosed by the solder mask in the via holes..
Some recommend to open the vias ... others say closed vias are no problem

3) ground plane, copper pour
Again: as long as it works satisfactory ... no need to worry.
But copper pour is not comparable to a solid ground plane. In worst case you gate increased EMI, higher voltage spikes, increased power dissipation, crosstalk, increased long time failure rate. No chance to validate this from your photo.

Klaus
 
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    Hilti

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Hilti

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Klaus,

Thank you very much for your valuable comments. My PCB is working well but not looking handsome :)

2) solder mask on vias vs not..
2- As far as I saw these white ones are not vias these are just pads. There is a pad that almost connected all of the vias. What is the purpose of it?

3) ground plane, copper pour
But copper pour is not comparable to a solid ground plane.
3- So using ground and power as a solid plane and make connections with fewer polygons are better? Did I understand right?

Thank you,

Hilti
 

BigBoss

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Placement will be a bit slow due to angled placed components.
An extra electrolytic capacitor will also bring extra cost.
Otherwise it looks pretty good..
 

    Hilti

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KlausST

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Hi,

So using ground and power as a solid plane and make connections with fewer polygons are better? Did I understand right?
Yes, one, but solid.

Klaus
 

    Hilti

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c_mitra

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Just my rule of thumb:

Other considerations apart, one with a total track length - less is better.

Other things being similar: one with fewer vias - less is better.

One with split ground plane - worse than one solid

One with all components 0, 90 or 45 degree aligned -better than one at different angles

Layout nicely labeled on the silk screen - better- with warnings and other info
 

    Hilti

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