Best PCB material?

During my casual perusing I have found a number of different types of pcb out there... some claiming exotic benefits because of the material they used.

I thought a conductor was a conductor?

Anyway, I have read about stuff like "linear crystal" copper being used in speaker wires to audible benefit, also silver and gold plating along wires and on pcb boards.

So do various purities of copper and/or plating really make a difference in a pcb? Is there consensus on which is good-better-best?

I once read about a nut using a plate of copper and routed out the pathways in a CNC machine. Seemed excessive but in the quest for the ultimate, who knows...
 
I have read about stuff like "linear crystal" copper being used in speaker wires to audible benefit,
if this is your concern then go back to the traditional way the valveheads did it. Direct wired across tag strips.

I wouldn't worry about PCB material at all.
FR4 is industry standard and does quite well.
Any plating with gold or silver is a waste of money.
Soldermask makes sense of course, also industry standard.

Most important is good PCB layout. Better worry about getting this right.
This Member has his head screwed on clockwise.
 

jcx

Member
2003-02-17 7:38 pm
..
some real concerns - more audiophoolish "puffery"

there are measurable deficiencies in FR4 and other common PCB materials - well known in precision signal conditioning at higher circuit/source impedances - look up "dielectric hook"

of course audiophools are notorious for not knowing "the numbers" and pointing at any imaginable (and some imaginary) physical effects as causing "night and day" audible differences in uncontrolled sighted listening tests

so exotic teflon boards developed for GHz circuits have been used in audio

but more practically, if you know what nodes are high impedance you can just "air wire" those, also press in teflon or alumina standoffs are sometimes used in low leakage circuits for the sensitive nodes

clever layout can also get you much reduced pcb parasitics - someone has patented using the PCB trace guarding/shielding that is employed in high impedance instrumentation specifically in audio amplification - because such layout techniques also mitigate the nonlinear dielectric effects of the board substrate by "bootstrapping" away the pcb trace parasitic capacitance


the trace material question is less compelling by the engineering numbers – but there are IPC grades for copper foils with the high flexibly RA foils presumably having better oriented, large grain structure than the nowadays ubiquitous additive copper plating

I have speced 6 oz copper in a electric water heater control pcb - an obscure limitation was the allowed temp rise in the faston connector
 
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Ian Finch

Member
Paid Member
2010-04-11 4:22 am
Coffs Harbour, NSW
I tend to see Audiophoolum (products manufactured specifically for audiophools) as exploiting any and every known departure from audio industry standards for big profits.

The key identifier to excellent audiophoolum is ignorance: by offering of a product or technology that is largely unknown to the public and even audio technologists.

Here's the greatest piece of everlasting hogwash perpetrated on audio: Oxy-free and/ or "monocrystalline" copper cables, connectors, you name its. Others occuring through gross misunderstanding - such as directional cables - are still equally phoolish IMO.

I guess the PCB is fair game for generating the same paranoia that feeds phoolishness so well, though I don't think milling solid copper plate or sheet is quite the same as CNC engraving the foil on FR4 etc. to make prototype PCBs. The latter is quite a rational and economical process, AFIK.

As JCX illustrated, there are are actual applications in electronics where some of these technologies are justified and necessary but not often in areas that concern us - even in our dreams.

It's pretty easy to see who is most vulnerable to audiophoolery but that's probably not a good subject to discuss around audiophiles generally.