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Electronics => Electronics => Topic started by: airman00 on December 26, 2009, 08:24:34 AM

Title: Right angle PCB traces
Post by: airman00 on December 26, 2009, 08:24:34 AM

At what frequency would it matter if the PCB trace was at a right angle or not? Would a 16MHz AVR microcontroller require non-90 degree angle traces for communication at 115200?

Title: Re: Right angle PCB traces
Post by: guncha on December 27, 2009, 03:36:59 AM

I read somewhere, that you should start to think about trace shapes and radiation and what not when reaching several megahertz. 115200 bits per second is way below that so there shouldn't be any problems. Just, don't take this for granted.

Title: Re: Right angle PCB traces
Post by: Soeren on December 27, 2009, 06:56:08 AM

Hi,

That depends... (on waveforms and voltages etc.)
If you have a fast rising transition, you have lots of harmonics right into radio frequencies.
If you have traces nearby that's sensitive, you have to be more carefull .
But you shouldn't ever use right angle corners if it is possible to avoid them (which it allways is), since they're more prone to lifting and to "decomposing".

Right angled PCB traces are the mark of poor amateur designers - why do you want to do it that way?

Title: Re: Right angle PCB traces
Post by: airman00 on December 27, 2009, 12:54:05 PM

Quote from: Soeren on December 27, 2009, 06:56:08 AM

Hi,

That depends... (on waveforms and voltages etc.)
If you have a fast rising transition, you have lots of harmonics right into radio frequencies.
If you have traces nearby that's sensitive, you have to be more carefull .
But you shouldn't ever use right angle corners if it is possible to avoid them (which it allways is), since they're more prone to lifting and to "decomposing".

Right angled PCB traces are the mark of poor amateur designers - why do you want to do it that way?

Thanks, I was just curious and wanted to understand further.