Copper tracks conner angles

[xeclipse]

Hi,
I've read in several posts about 'thinking of electrones as your car' so you should provide rounded corners or 45 degree bends. What's the need when component leads meet with the copper tracks at 90 degrees??

[jcx]

its a myth - audio frequency currents basically don't care about anything but the least resistance path

in PCB "design for manufacturability" some trace features are avoided because of etching limits, or rare failure mechanisms, some hypothetical, or out dated by improved materials, processing


at RF frequencies, modern digital, the rules change because the high frequency components are sensitive to the waveguide/transmission line properties of the trace/plane geometry - then you don't want the impedance discontinuity of sharp 90 degree bends

[peranders]

So in your case I think we can conclude this:

Short track as possible
Cut corners or rounded corners
= Looks good!

It looks very unprofessional to have 90 deg angles on a pcb.

[nigelwright7557]

Keep tracks as short and as fat as possible.
45 degrees is good.
Use a powerplane if possible.

[DF96]

You need to think about what signals your tracks are carrying. If power, then wider tracks will give less voltage drop. If signal, then narrower tracks will give less capacitive coupling. In audio you may find that minimising loop area is more important than other things, so 'go' and 'return' paths should be near each other. Don't blindly follow rules (especially silly rules found on the internet); try understanding instead.

[volume knob]

Originally Posted by xeclipse

Hi,
I've read in several posts about 'thinking of electrones as your car' so you should provide rounded corners or 45 degree bends. What's the need when component leads meet with the copper tracks at 90 degrees??

Rounded corners are used in R.F work to keep the track width uniform so there are no sudden changes in impedance, inductance, capacitance etc. They are not used to help the electrons turn corners. Electrons weigh next to nothing and can corner at light speed without a problem

At audio frequencies the inductance and capacitance is to small to have the same effect as it does at R.F and the lower impedance of a 90 degree corner (due to the wider track width) will only make a tiny difference to the overall series impeadence

[xeclipse]

Its evident different diyers have different reasons. Even if rounded corners are used in RF signals pcbs,it seems to work for the famous musical Aksa55.

[DF96]

Have you actually read post 6? Even where rounded corners are correctly used (RF) it has nothing to do with electrons' cornering speed.

[qusp]

yes i wondered about this too and acko explained it for me as above re impedance consistency/control. i would also think that perhaps even at some modern dac clock and DSP speeds that RF technique would not do any harm? certainly other RF technique is put to good use in dac layout.

[jcx]

electrons do have mass, don't move too quick in room temp metals, strictly speaking it would be photons in their guise of EM fields that travel ~ 1/2 c in most transmission lines

for audio corners really don't matter except for how the size/orientation of loop areas change for mutual inducatance linkage