Are *.pos Good as Pick-and-Place Files?


#1

Are the *.pos files good enough for an assembly house? I am getting the following message from the assembly house which is going to build a small prototyping run for me:

I have checked with our programmer and we can’t use the provided files as placement data. Would you please help to provide another placement data?

Placement data is also known as XY DATA, which gives the centroid coordinates for all SMT parts that are to be installed, and come in the below formats.

Usable forms of Placement Data: Any of the following files can be used - .ipc/ .tgz/ .asc/ .CAD/ ODB++/ Pick & Place Data or outputs with extractable XY Data /.MNT / .MNP

I have provided them with the .pos files, which contain the “XY DATA” and rotations. Is it just a matter of relabeling the .pos files to .asc?

I think this post is related to XY parts coordinates for pick and place, but since I don’t know if that thread is active any more, I started a new thread here.


#2

Ah, I saw you revived a 3 year old thread, but did not want to answer there.
If the file format of your file is incompatible with your boardhouse, it might be a good idea to ask them for an example placement file in “.asc” format and study what it looks like.
That takes some of the guesswork out of the loop, and is easy and quick for them to do.


#3

Thank you. I think I am dealing with a case where their “programmer” doesn’t know much about his “programs.” I guess the question is whether others have used the *.pos files successfully for assembly.

Maybe I should delete my posting in the other thread? I am new to kicad.info, so I am not 100% certain if a dead thread can be revived.


#4

Is this your first go at outsourcing assembly?

I am not too familiar with the details fo placement files, haven’t used them myself.
In the last 40 years there have been a lot of different variatons of gerber, excellon, placement, and other files to send information from a PCB package to boardhouse. and loads of opportunities for failures / inconsistencies / problems.
Pretty recently (compared to 40 years) there is a “new” gerber format (I assume supported by KiCad?) to combine at least the information of all the different layers ( copper, solder masks, silkscreens, and the drill coordinates) in a single standarized format. I do not know if that file format also supports the placement of the components.

Overall. Because there has been no real standard, the file formats between you and the board manufacturer and the component placement often wastes a lot of time and needs human intervention to negociate which versions of which file formats have “enough” compatibility to make a “usable” product.
It (probably) is not fair to blame it on “their programmer”. It is the lack of standarized file formats which is the root cause of the problem.

Some manufacturers are beginning to to support KiCad files directly and extract all the info they need from that. You just send them your KiCad project and don’t even have to make Gerber files.

Sometimes it seems that the “industry” never learns.
“soic-8” housings with different spacing s for the pads.
“0402” SMD resistors without knowing if they are “imperial” or “metric”.

In one of the other posts here I read that some of the manufacturers use the Digikey order numbers as a reference. You supply digikey order numbers for your components. They put “something compatible” on your PCB. Can you imagine where this could go wrong?

Edit:
The Gerber version with the embedded meta information is called RS-274X2 and has been updated in 2014
https://en.wikipedia.org/wiki/Gerber_format

One of the links I followed from https://duckduckgo.com/html?q=RS274-X as a starting point claimed that currently 95% of industry conforms now to the new Gerber standard. The Cheap Chinese Factories are probably the last to conform.


#5

Kicad V5 has ‘experimental’ support for Gerbers V2.


#6

Thank you for the info.

Yes, it is my first go at interfacing with an electronics assembly line. Prior to now, I designed and laid out prototype pcbs which were then populated by hand.

I think there is nothing wrong with the .pos files (but not having prior experience with them…). I just communicated with the guy “in the trenches” and he told me my .pos files are OK for him. I think that purely bureaucratic layers intercepted my files before they got to him and created all this unnecessary trouble. It seems I should have just given the .pos files a new .asc extension and I would have been done. But, again, being unable to draw from past experience, I was not sure.

Thanks to everybody for their help.


#7

I’ve always just sent the .pos file with no complaints. To several manufacturers.


#8

@HSPalm: Thank you for your info. It’s nice to have another reference point.


#9

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