Author Topic: Are some pcb's generally just too junky to be bothered with?  (Read 381 times)

xdfo

Are some pcb's generally just too junky to be bothered with?
« on: January 17, 2021, 04:04:49 PM »
I am trying to finish up a kit, I'm not going to name the manufacturer - but what I noticed when fixing a couple of mistakes (good ol'backwards transistor and cap) was the pcb throughholes appeared to be teflon with a foil coating.  What became apparent was just looking hard at these holes would cause the foil to flake off. 

Is this common with diy pcbs? Or indicative of crap quality?  And is it possible this fragility might be the source of some completely undebuggable issues I'm having? 

Is there a fast way to check if througholes that appear ok upon soldering might actually be damaged?

Cheers,

iainpunk

Re: Are some pcb's generally just too junky to be bothered with?
« Reply #1 on: January 17, 2021, 06:00:30 PM »
Quote
Is this common with diy pcbs? Or indicative of crap quality?
depends if you etched or milled them yourself, or ordered them through a quality supplier.
i have had very wide range of quality on DIY etched pcb's at school, but i have never had trouble with PCB's i ordered.

Quote
And is it possible this fragility might be the source of some completely undebuggable issues I'm having?
that's a possibility, yes, i have had that with the first fuzz face i build, i etched a pcb at school, but while soldering, i totally overheated the pads and traces.

Quote
Is there a fast way to check if througholes that appear ok upon soldering might actually be damaged?
yes, a multi-meter at the beep-setting

cheers, Iain
half man - half snail - 6 feet to scale - Snail man's - not frail - He's been - to jail
snail man [x11]
snail man is fuccing real

xdfo

Re: Are some pcb's generally just too junky to be bothered with?
« Reply #2 on: January 18, 2021, 04:23:26 PM »
Oh this wasn't a pcb I'd made. This was more of a question like do some commercially available pcb's have really low quality.

idy

Re: Are some pcb's generally just too junky to be bothered with?
« Reply #3 on: January 18, 2021, 05:23:20 PM »
Some do have traces that lift too easily, but this is also often "operator error" with the soldering iron. Ironically, a soldering iron that is not hot enough means you spend too long on a joint and spread too much heat. A good hot tip only takes a second or 3.

xdfo

Re: Are some pcb's generally just too junky to be bothered with?
« Reply #4 on: January 18, 2021, 06:14:27 PM »
Yeah to note I had to spin a cap I had placed backwards and after re-tinning the joints, clipping the cap off, putting flux on my braid and gently removing the solder there was still damage because the lead, as I was pulling it out, brushed against the hole and tore off the foil  :icon_cool:



iainpunk

Re: Are some pcb's generally just too junky to be bothered with?
« Reply #5 on: January 18, 2021, 06:26:22 PM »
Oh this wasn't a pcb I'd made. This was more of a question like do some commercially available pcb's have really low quality.
owh, yeha, there are some questionable PCB's available for cheap on the web, especially from India, sometimes from China too, but less frequent.

cheers, Iain
half man - half snail - 6 feet to scale - Snail man's - not frail - He's been - to jail
snail man [x11]
snail man is fuccing real

xdfo

Re: Are some pcb's generally just too junky to be bothered with?
« Reply #6 on: January 18, 2021, 07:07:27 PM »
Yeah this was a somewhat expensive modular synth board from the UK :(  Tayda's pedal pcb's are at least twice as resilient.