Width of Track

Stompboxes circuits published in magazines, books or on DIY electronics websites.

Width of Track

Postby POTL » 10 Oct 2017, 22:04

Tell me what is the width of track should be done on the PCB?
My program offers a thickness of 13 mils, my friends suggest to do 31 mils or more.
Power 9-18 volts
not more than 100 ma
usually 15 to 50 ma
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Re: Width of Track

Postby nr372 » 10 Oct 2017, 23:30

The currents flowing in guitar effects are usually small, so the exact track width isn't critical. If you're ordering PCBs from a professional supplier, using very narrow tracks (less than 10 mil) can cost more. If you're etching PCBs yourself, it's safer to use wider tracks (30 to 50 mil).

Using track widths of 20 to 40 mils will be fine for most through-hole PCBs. If you're designing with SMD parts, you'll probably need to make the traces a little smaller.

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Re: Width of Track

Postby 287m » 11 Oct 2017, 13:39

for me
fab 2 layer pcb : signal 10, power 24, prefer power all in top
self etch : both signal and power 24, isolate 28

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Re: Width of Track

Postby deltafred » 11 Oct 2017, 16:29

A friend of mine taught technology (which covered electronics) in a school. Part of their final year project had to include some basic electronics (nothing more complicated than a 555 timer driving a LED or buzzer) and they had to design and etch their own PCB.

When they powered them up a good proportion of them didn't work, not because there was anything wrong with the design (they had a book of standard circuits and strung a few together) but because they would make the tracks spiders web thin and the pads a fraction larger than the drill they used.

Just before exam time my friend would come round with a box full of dead boards and I would fix most of them. 99% of the problems were because the tracks had etched through, usually where the resist had got scratched, or pads had lifted off and the copper fractured where it attached to the track.

I recommended that they make the pads about 3 times larger and make the tracks almost the same width as the pads. The next year most of them worked first time.


The etching solution also lasts longer because you are not dissolving as much copper.
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Re: Width of Track

Postby POTL » 11 Oct 2017, 21:32

deltafred wrote:A friend of mine taught technology (which covered electronics) in a school. Part of their final year project had to include some basic electronics (nothing more complicated than a 555 timer driving a LED or buzzer) and they had to design and etch their own PCB.

When they powered them up a good proportion of them didn't work, not because there was anything wrong with the design (they had a book of standard circuits and strung a few together) but because they would make the tracks spiders web thin and the pads a fraction larger than the drill they used.

Just before exam time my friend would come round with a box full of dead boards and I would fix most of them. 99% of the problems were because the tracks had etched through, usually where the resist had got scratched, or pads had lifted off and the copper fractured where it attached to the track.

I recommended that they make the pads about 3 times larger and make the tracks almost the same width as the pads. The next year most of them worked first time.


The etching solution also lasts longer because you are not dissolving as much copper.


Thank you
With the etching of the boards there, I made with a thickness of 32
mil without problems, but I use a lot of SMD and it's very inconvenient to do a trace when the width of the path is larger than the width of the component's output
sot23 so8
My search on the Internet led me to the fact that it is quite possible to make trails with a thickness of 16-24 mil
I was helped by my old friend who has a small business in the field of creating and repairing tube amplifiers, he does not use smd components and generally works with coarser materials and components, and higher currents, probably he did not take my needs into account when he gave me advice . :D
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Re: Width of Track

Postby deltafred » 13 Oct 2017, 08:57

POTL wrote:Thank you
With the etching of the boards there, I made with a thickness of 32
mil without problems, but I use a lot of SMD and it's very inconvenient to do a trace when the width of the path is larger than the width of the component's output
sot23 so8
My search on the Internet led me to the fact that it is quite possible to make trails with a thickness of 16-24 mil
I was helped by my old friend who has a small business in the field of creating and repairing tube amplifiers, he does not use smd components and generally works with coarser materials and components, and higher currents, probably he did not take my needs into account when he gave me advice . :D

A lot depends upon your methods.
If you always etch with fresh chemicals and use sharp drills then you can leave less copper than if you are trying to get the last etch out of almost spent chemicals and your drill bit is getting a bit dull.

My friend was on a tight budget and was trying to get as many PCBs as possible out of a batch of etchant so etching took longer and longer (that is when you start having problems). The kids often broke drill bits but some would survive until they were getting dull which resulted in pads lifting off the board.
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Re: Width of Track

Postby J0K3RX » 17 Oct 2017, 01:53

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