PCB manufacture - troubleshooting tutorial

Hi,

Following on from a previous post, can anyone point me in the direction of a good tutorial for troubleshooting home PCB manufacture?

Making a PCB typically involves a number of separate steps, each of which could go wrong, often it's not until the final step (the etching) is complete that you realise something has gone wrong, but by then it's too late to work out which of the earlier processes failed.

What I'd really like to see is some good quality photos of under-developed, over-developed and correctly developed boards and similar photos of under and over etched boards.

Too often I find myself with a dodgy board and I find myself asking were the chemicals too warm or too cold? where they too dilute or too concentrated? Did I expose the board to UV for too long or not long enough?

I've made many boards (some of which have worked), and I'm familiar with the theory of what I ought to be doing, the problem is that a picture is worth a thousand words, but I can't find any suitable pictures.

Can anyone point me in the direction of a good tutorial - something that includes pictures of not just good boards, but also faulty boards and what went wrong

thanks

What normally happens is someone posts apicture here and asks.
Searching online will find any no of posts and instructable on pcb manufacture.

There is actually very little to go wrong with the process as its fairly robust.

The problem is almost always withe the quality of the print.

Using litho masters i have never had a failure except for doing something stupid like using the wrong dev bottle etc.

Overdevelopment is almost always because the print is not good enough and people try to compensate, it never works well.

ditto to what was said above ^^

really.. as long as you get good adhesion of your 'transfer'.. things should be good to go.

that being said:

1.) I say design your project using legit/real schematic design software.. (Eagle comes to mind). This will help you as it has rules/restrictions that you will benefit from to ensure a sound design. And you can just print out the Gerber file to use as your transfer image.

2.) transfer: I myself no longer do DIY boards.. (unless I truly, truly need something ASAP.. professional boards are just too cheap to not go that route if you can wait for shipping) $10.00 USD for 10x pcbs is awesome! But when I do.. I always use GLOSSY PHOTO PAPER.. and a LASER PRINTER (no bubble jet..etc)

I have always used a clothes iron to transfer the print to my copper clad board..

washed/rinsed under cold water to remove the paper.

at this point inspect the board for a GOOD transfer... if there is any problems.. use a sharpie to fill in gaps or breaks...etc..

3.) Etching:

IMHO.. a KEY step is to agetate/mix/swirl the solution while the board is in it.. I have heard other use small fish tank pumps.. (but that was a bit too involved for me)

I actually have used some old RadioShack DIY kit (copper board, solution....etc) with great success.

or you can make your own solution.. (might be a bit more green this route.. but be careful and understand what you are working with..for both use and disposal)

even before this step, you can use a multimeter to check conductivity to ensure no breaks in the traces.. or merging of traces.

the only boards that have FAILED for me... was not due to it being DIY.. but electronically the schmatic was not sound (hence why I try ti use Eagle no a days instead of 'photoshop') :slight_smile:

Good luck..

post back with SPECIFIC questions if needed.