How heavy a copper clad needed for guitar PCB?

[Che_Guitarra]

Now the proud owner of an X-Carve CNC machine, I want to put it to use and etch out a PCB for a JCM800 guitar amp project.  I've engraved a couple of 19" front panels and they came out surprisingly quite well, so i'm keen to see how it handles the etching of a PCB.

Anyway, i'm digressing...

I'm just wondering how heavy a copper clad I would need on a PCB to suit such a purpose?  My local hobby shop has some 1oz copper clad PCB sheets... is this heavy enough?

 

[ruffrecords]

1oz copper is fine for 99.99% of applications.

Cheers

Ian

 

[CJ]

if  you are building a combo amp with the speakers and the chassis in the same box, then use the heaviest stuff you can get.

Another Fender DeVille  came in the shop today, the cheap PC boards just get torn up from vibration, and when you go to resolder all the cold solder joints, the pads lift up like a frog in a dynamite pond.

 

[ruffrecords]

the pads lift up like a frog in a dynamite pond.

And there was me thinking raining frogs was a natural phenomena 

Cheers

Ian

 

[Newmarket]

if  you are building a combo amp with the speakers and the chassis in the same box, then use the heaviest stuff you can get.

Another Fender DeVille  came in the shop today, the cheap PC boards just get torn up from vibration, and when you go to resolder all the cold solder joints, the pads lift up like a frog in a dynamite pond.

That sounds like the problem there is the quality / thickness of the PCB material itself as opposed to the thickness of the Copper ?
Guessing the boards the OP has in mind would be fibreglass - FR4 ?

I'm not familiar with etching boards on a CNC machine but I guess that the boards won't be through plated as you'd likely get on conventionally produced pcbs ? That doesn't help the pad lifting scenario you outline.

As has been said 1 0z (35um) Cu is fine for almost all applications.

 

[JohnRoberts]

1oz should be adequate, copper adhesion is a separate matter.

For single sided design make sure you use decent sized pads.

[edit] a common reason for copper delamination is overheating so use proper size iron and large pads will also help. [/edit]

[edit2] only time we used heavier than 1oz copper was inside very high power audio amps. We even left off the solder resist so solder could build up on the traces for even lower resistance.  [/edit2]

JR

 

[Newmarket]

For single sided design make sure you use decent sized pads.
JR

Yes 

 

[Rob Flinn]

Do it point to point & avoid these problems.........................

 

[Che_Guitarra]

Thanks guys.  1oz board it will be.

I plan to do it Marshall Astoria style;  PCB and turret posts.  And head format.

 

[buildafriend]

Now the proud owner of an X-Carve CNC machine, I want to put it to use and etch out a PCB for a JCM800 guitar amp project.  I've engraved a couple of 19" front panels and they came out surprisingly quite well, so i'm keen to see how it handles the etching of a PCB.

I have been trying with all of my restraint not to buy a Chinese 6040 cnc.. but it's getting more and more tempting. The x carve price is scaring me away from it. Please feel free to PM me and tell me all about your experience with it so far! I'm not paying monthly for a maker space membership again unless I really have to. It's more about milling holes in steel or aluminum enclosures for me. PCB's are cheap to have made from China and work great, metalwork is expensive.

Anyway, you can make up somewhat for the track thickness with track width. Make your isolation gaps large for tube circuits and don't put your AC heaters on the boards. Bend the tube socket pins out and solder your heater wires to that.

All the best,

 

[john12ax7]

Milling pcbs is rather unpleasant and generates hazardous dust. Just something to consider.