Generating Centroid (pick and place) from Gerber - Page 1
Forum section: electronics / general

author: SMTech
author_rank: Frequent Contributor
timestamp: December 01, 2018, 03:24:05 pm
content: It probably doesn't crop up that often for most, but every now and then I encounter a situation where a client can supply us with gerber data but for whatever reason no longer has access to the original cad files to generate the XY centroid data I ideally need to setup the pick and place recipe. This seems to happen mainly when a relationship has broken down between a designer and a customer, or because for some reason they are simply reluctant to go back to whoever did the work and say "please could you include one of these in your datapack from now on"; both situations seem odd, I would consider it extremely unreasonable/petty if someone was not prepared to click the 2 buttons often needed to create the file.. unless perhaps some large bills were in dispute.As most people who have used pick and place will know, almost all machines let you "Teach" a PCB manually, whereby you use the overhead camera to locate each device in turn and store the coordinate data, however that is both extremely slow and very difficult to do if there is any ambiguity in the silkscreen, if indeed there is one.Our first pick and place was a Versatronics RV4, its primary method for data entry was via Gerber, it was the only method in the training manual and perhaps the only built in method that was reasonably easy to use and worked as expected. This software did two things - scanned the stencil layer and matched aperture patterns to your component definitions and scanned the silkscreen or assembly layer in an attempt to read the component references. Once it has done that it could step through each of those references and would have a stab at guessing which pads they belonged to, which you could then correct as well as tweak the orientation, it actually worked quite well except the obvious inability to tell the difference between 6/9 or p/d/r etc. A very typical PCB for us back then was ~150-250 parts and could usually setup in about 2 hours if the package shapes were familiar/known. Because Versatronics software insists to you disable hardware acceleration, any redraw requests were of course very slow, making scrolling a PCB quite painful, last I tried this software didn't seem to work in a VM.These days the RV4 is long gone and I have looked for alternative tools to do the same thing, I have found several the pattern matching is basically how they all work.GC-Prevue/Powerplus - I gave a trial version of this a go, maybe its the fact I don't do any CAD work in my day to day but I found this software really hard work. In fact I gave up before I had even completed a simple board, this task should be able to be described in a single page of the manual, this is not the case for Mentor.GerberGrab - Appears to be a once commercial effort that is now free, and sort of seems to work. I think perhaps if you used it a lot and got used to its weird idiosyncrasies (randomly selecting things, weird menus & dreadful workflow) you could do the job with this software with some measure of success. Like versatronics&GCPrevue (some versions/an option) it does try to read the silkscreen to generate a BOM it can then match with one you import.FAB3000 - This is the one I currently favour, it doesn't make any attempt to read text so that becomes a secondary task: stepping through its identified components giving them references that match your imported BOM. Unlike GC you can write down the process in a few sentences, the interface has a decent modern appearance and the software has a decent bunch of other features you might find useful if working in other formats. Once I even only had a silkscreen/assembly layer in PDF form and it imported aligned and scaled that to the gerbers perfectly. It can also be rented for $75/month (as part if a suite of tools) after its trial period making it possible to only pay when you need it. Its sister package DFMNow is also a perfectly decent free Gerber/ODB++ viewer.Unisoft ProntoPLACE - This is in some ways very similar to Fab3000, however the first thing you will notice loading it up is that it immediately reminds you of computing 20 years ago, it is frankly downright fugly and feels very Win9x, that in itself shouldn't be a problem. However both times I have tried it I have managed to to crash it very quickly (Win9x stability emulation?!) either with the data I was importing or by doing something in not quite the order it wanted me too or for no reason whatsoever, considering how long this software has been around I don't think that is OK and suggests a serious lack of any error handling in its code. However Unisoft offer a very comprehensive suite of tool for programming your machines (all of them in the line) and running your factory, so someone must be buying it so it can't be truly terrible... can it? What I find particularly odd is this software has no published pricing even tho' you can rent it and deal directly with the developer - another pet hate of mine.Hopefully this was interesting to some ...

author: Mattylad
author_rank: Regular Contributor
timestamp: December 01, 2018, 05:11:26 pm
content: Did you try GC-Place rather than GC-Prevue/Powerplus?I have used GC-Place before and found that it was very good at identifying component patterns and making placement programs.Of course it took some trial and error, some learning and configuration so I could output the code in the right way - but it made placement file generation pretty quick for me.Although this was 10 years ago...

author: SMTech
author_rank: Frequent Contributor
timestamp: December 01, 2018, 05:56:57 pm
content: Literally no idea anymore seeing as they are quite blatantly all the same program with functionality enabled/disabled, my main issue wasn't the features its the hideous and baffling interface, incomprehensible buttons and icons and tedious steps that put me off. However it did seem rock solid which can't be said of the rest.Perhaps the most annoying thing about all of them is that they are ever needed, if you design PCBs for a living you should always include centroid data with your standard output, and if you are in the business of outsourcing such things you should make sure the contractor gives this stuff to you.All these processes, along with manual teach introduce opportunities for error on top of new design issues like getting polarities correct etc when you don't know how consistent the designer is in defining rotations.

author: mrpackethead
author_rank: Super Contributor
timestamp: December 01, 2018, 07:41:25 pm
content: the life of a contract manufacturer is tough. I'd hate to have to deal to this kind of drama.

author: Reckless
author_rank: Frequent Contributor
timestamp: December 02, 2018, 11:12:50 pm
content: I just purchased a 3 month license of UniSoft ProntoPlace last week. I might have gone FAB3000 if I had come across it. Do they offer training/support for $75/mo? I ended up with ProntoPlace for this reason. Your review of ProntoPlace is dead on: ugly, crashy, built for windows 95. In the end we got it to work but it was not easy.I am surprised that no one has developed an easier solution. Our pcb designer uses free solutions which don't generate proper xy centroid data.

author: SMTech
author_rank: Frequent Contributor
timestamp: December 03, 2018, 10:41:41 am
content: Quote from: Reckless on December 02, 2018, 11:12:50 pmThere is a pretty decent manual (tho' its not exactly as comprehensive as we used to expect help files to be), Youtube videos & I have had a fairly decent email conversation with someone on their developer side about one bit I think needs to work differently because some of their overlays were obscuring the the text I wanted to be able to read off the assembly layer so I could type it into the RefDes box.QuoteWhat solutions are they, seems a very odd feature to be missing?

author: ANTALIFE
author_rank: Frequent Contributor
timestamp: December 03, 2018, 10:24:56 pm
content: +1 for FAB3000Every once in a while we get an oddball customer who don't have the ECAD PCB (or even the NC Drill) file and want us to:Move some pads/holes & update the silk/copper layerAssemble the board with no centroid/PP filePanelize the designAnd with each case the task becomes so much easier through FAB3000

author: Reckless
author_rank: Frequent Contributor
timestamp: December 04, 2018, 06:48:05 am
content: One of these pcb proto companies gives free altium designer but makes weird panels that are not properly cut. We use another software to depanel them. Then we send to China to make pcb array.