PCB Design Mistake-Forgot to Import Latest DXF

[ngkl99]

Hi,
recently my colleague did a mistake.
He forgot to import the latest DXF into the PCB data and modify accordingly.
May I know what is the best preventive counter measure to avoid repeating the mistake?

Thanks!

 

[barry]

Wait, you want a method to prevent forgetting to do something? When you figure this one out, I think there'll be a Nobel Prize in it for you.

 

[Mattylad]

Ditto!

Check lists? (you will forget to check).
Procedures? (you will forget to follow them).

How about meetings? Have a review meeting before the board is made, have this in one of the check lists for that meeting and have a procedure that forces to to have a meeting before every board is sent for manufacture

It will only add more time onto the job - but hey ho....

 

[ngkl99]

u r right.
checklist: forgot
job flow: forgot
add new: meet the requestor face to face before cad out, to avoid missed email (actual cause)

 

[marce]

Version numbers on all files, update numbers/letters with changes, correlate to other data and keep a history of changes...document control.

 

[ngkl99]

Hi marce,
I like your idea of update the dxf filename with version/numbers.
About correlate to other data, it means if we don't follow the latest DXF, then we can't proceed to nxt process right? But I need some examples to be clearer...
TQ!

- - - Updated - - -

I can think of one. Do DXF comparison job. But I don't know if any software can perform it. Any recommendation?
tq!

 

[T5400]

in my shop if pcb guy screw the thing it paid the next pcb run

that effective to not forget again and realise that take 2 hour to re-validate cost less that a pcb run

 

[Mattylad]

OK I have come up with an idea that might help you.

• You have a peg board, inserting each peg closes an electronic circuit.
• When you have completed the schematic you add a peg.
• When you have had the schematic review you add a peg.
• When you have done the PCB you add a peg.
• When you have checked the data is the most upto date you add a peg.
• When you have had a PCB review meeting you add a peg.
• When you have done the Gerbers etc you add a peg.
• When you have checked the Gerbers you add a peg.
• When all pegs are in for a job the entire circuit is made and a marble is released, this falls down a tube and closes a microswitch contact.
  The switch releases a key which open a safe box that has the key to the draw that you keep the access card for the computer that is the only one configured to allow you to email the files to the manufacturer.

We all make mistakes from time to time, forget to check something or update something.

I had a colleague who forgot a resistor on a sub circuit, but the sub circuit was not tested until about the 5th revision of the board.

It happens, just try and ensure that you remember better next time and perhaps you wont need to add lots of bureaucracy (or daft peg boards) :lol: ;-) :lol:

 

[andre_luis]

A DXF viewer to check what will be sent can solve the problem, before send data to PCB manufaturer.
Also it is recomended to assign PCB version ( printed on PCB ) to Purchase Order, due this precedure certify correct version manufactured.


+++

 

[NIKHILRAJ]

DXF generally obtained from 3d models (solid works ,pro- e etc). What we practice is before gerber genaration there will be a mechanical fitment check (from PCB tool DXF file of component placement ,board outline etc will be generated or IDF format files like emn,emp etc) by the person who generated the mechanical drawing.
There will be a QA person who recieves the gerber file from PCB team and DXF from the mechanical CAD team will compare the final gerber and DXF.

 

[Mattylad]

WHAT! no one wants to use a pegboard?

Marce was telling me that he wants one in the office, so he can hang his coat on the pegs.

:smile: :smile:

It's a good step to check the DXF against the design when it is finished. however that again needs someone to remember some way that it needs doing, what the DXF is and to know how to check it and what to check when looking at it.
Just checking against a DXF is not the be all and end all of checking a final design.