PCB Proto Board Control 1

[stevehano]

Does anyone have a good SOP (Standard Operating Procedure) document that they use to track proto boards?

Currently I have 8 different projects and I'm starting to receive boards all at once and of course everyone wants a proto board as soon as they are received. But what I don't want to happen is that I lose track of who has which board, what Rev they are at, what program rev is on the programmable chips, which boards need rework which don't, ect............

So does anyone have a good SOP for tracking PCB's they have used in the past that has worked well for them?

 

[MacGyverS2000]

Anything wrong with labeling the boards and chips with the matching info on a piece of paper or on a computer file?

A small block of white silkscreen on the PCB allows space for writing with a permanent marker (board revision, etc.), and a sticker on the chip should easily display the software version #.


Dan
Owner

http://www.Hi-TecDesigns.com

 

[stevehano]

I've tried using labels in the past, but most people aren't smart enough to leave them on the boards or chips.

I was thinking of maybe using different colored paint pens to track the different levels, putting a paint dot on the chip or on the board to signify the revision.

I don't know, I was just seeing if anyone had some good ideas.

 

[MikeHalloran]

Put a string of decimal digits or alpha characters in decreasing order in the copper. Scrape off the low ones when you revise the board.



Mike Halloran
Pembroke Pines, FL, USA

 

[stevehano]

Actually that is a great idea, I can still implement this technique on 5 of the 8 boards, as for the other 3 I'll have to implement it when I spin the copper.
Thanks Mike

Steve

 

[itsmoked]

We always did the standard tag with the tiny, cheap tiewrap. We put the boards SN on it then write the complaint if there is a known one on it. Then write notes on it as to what was wrong, what was repaired, replaced, and initial who did what. Also what outgoing tests were done and who did them. If you do all this, when someone is messing up you can solve the problem. Also you then have hardcopy of what's going on. While computer documenting is nice it has its problems. Like a dead HDD = all data lost. Or no PC at the rework station or cleaning station. Further more someone at a glance can tell what the next required process is without refering to a computer.

 

[Tofflemire]

Hello,

What we do is to put the part number and M0, M1, M2... in the copper.

Tofflemire

 

[VEBill]

The part number AND revision of the empty PCB itself should be part of the copper layout (written in the copper). It is not as if you can change the PCB without having the opportunity to update the revision text string. Trace cuts and jumpers are different, they are not usually part of the PCB part number. They are part of the next higher assembly, the CCA.

The part number of the Circuit Card Assembly (CCA, stuffed with parts) can be printed on the PCB as part of the silk screen layer. The revision of the CCA needs to be added manually (hand printed or stamped) because it should change with (for example) resistor value changes. The silk screen could contain the prefix "Rev." and an empty box.

It helps if you add the prefixes PCB and CCA to the P/Ns so that people will know which is which.

In summary (an example):
In Copper: "PCB P/N 98-12345 Rev. B"
In Silk Screen: "CCA P/N 99-98765 Rev. [ ]"
Hand Stamped: "D" (in the CCA Rev. box above)

This method covers 99% of all eventualities for the pure hardware side of things.

Now - programmable devices is a whole 'nother issue. It may help to clarify your thoughts that programmable devices might be anywhere from hardware (FPGA) to software (uP) or anywhere in between (fuzzy distinction these days).

If the chips can only be programmed once, then simply add a decal (P/N + Rev.) to each chip. It helps to use a very fine font.

Sometimes these devices can be updated in the field (firmware updates can even be done via satellite), which makes labling the devices a huge (sometime non-) issue.

In those cases, it might be best to roll-up all the SW and firmware into one tracking number and add a decal to the CCA that says something like "SW configuration 666-12345 Rev. A at time of manufacture".

 

[VEBill]

Re-reading the original question, there are some additional points:

Track the exact configuration of each S/N or each product can be done with As-Built Logs. The log can be an on-line database, or a simple book, or anything you want.

Tracking who has what is a simple "sign-out" log.

Tracking what needs updates can be done using Problem Reports and tracking their progress and closure.

You can see that different information is kept in different databases. I wouldn't try to mix it all into one tracking system.

 

[VEBill]

I forgot to mention the obvious: Serial Numbers (usually just at the CCA level, not the PCB level) are added by hand (typically stamped).