PCB panelization specifications

Discussion in 'The Projects Forum' started by rggmiranda, Jun 6, 2016.

  1. rggmiranda

    Thread Starter New Member

    Jun 6, 2016
    Hi, I have a question about when you send a board to be manufactured.
    I want to panelize my design. My questions are:

    1- Are there any standard size panels that I should use? I know the maximum of my manufacturer, and I want to stay way smaller than that, but apart from the maximum they do not specify any standard dimension, so can I use whatever I like? And when it comes to the pick and place machine, can it work with any panel size?

    2- How much clearance should I leave for V grooving? is it better to place one board next to the other or should I leave a piece of pcb between them?

    3- Still about V grooving, do they do it across the entire board or can I specify the limits of the cut in my design?

    4- Are there any standard vias sizes? I know maximum and minimum, but apart from that, can I choose whatever size or should it be 0,4 - 0,5 - 0,6 for example instead of 0,432.

    5- About feducials for the PCBA, should i put them next to the tooling holes in the top and bottom tab (I read about using a 0,25 Inch tab)? Any position particular or anywhere is fine?

    6- About tooling holes, same question as 5, which size and position should the be at?

    7- In my board I selected the board shape from a CAD file I made, in which I already had some mounting holes cut, so the board shape has those holes, should I specify in Altium that there is a hole in there or they can assume it from the board shape?Thanks in advance for any help
  2. Robin Mitchell

    Well-Known Member

    Oct 25, 2009

    To be honest these are all questions that you should directly ask your manufacturer.

    All the best,
  3. SLK001

    Active Member

    Nov 29, 2011
    None of these questions can be answered by people outside of your organization.

    1) The manufacturer will make any size board that you want that is under their maximum size.
    2) Add the clearance that you are comfortable with. Board material between PCBs is up to you.
    3) The manufacturer will put the V's where ever you want them.
    4) The manufacturer will have a list of their available drill sizes. You can put any size via down, but the manufacturer will have to procur the bit, or have a weird size fabricated. You will pay for this.
    5) Put the fiducials where ever you want them.
    6) Put the tooling holes where ever your carrier has them. Make them the size of your carrier tooling posts + 0.002".
    7) Why select a previously used shape when it doesn't meet your current needes? Create your own board shape.

    What is your manufacturing engineer saying about your board? What is the pick and place operator saying about your board? You need to bring THEM into your conversation, not us.
  4. rggmiranda

    Thread Starter New Member

    Jun 6, 2016
    Well, you answered most of the questions I've made, thanks. I will ask the remaining information to my manufacturer then
  5. SLK001

    Active Member

    Nov 29, 2011
    I think that you are missing my point. Where, exactly, are you in the design process?

    When I was designing circuits, I was limited by certain constraints set by others.
    1) My board had to fit inside an already fabricated chassis, so a mechanical engineer set the ultimate board dimensions.
    2) The board would be fabricated via pick and place and oven reflowing. The engineer in charge of the machine vision system told us where he wanted fiducials.
    3) The engineer in charge of the pick and place machines had carriers fabricated to carry my boards. He told us how many boards he wanted on a panel (2-up, 3-up, 4-up, etc). Since the carriers were already fabricated, this set where the tooling holes were needed.
    4) The engineer in charge of the final assembly told us how he wanted the boards to separate from the panel, whether by V-grooves, or routes and break-away tabs, or what-ever.
    5) Your process engineer may have even more requirements.

    So you see, the task is a team effort. If you don't bring these guys into the process from the very beginning, you will have nothing but trouble. The manufacturer could care less about your problems. They will make any board you want, whether it meets your ultimate goals or not.
  6. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
    He may not have the luxury of working in a company where each department/function had a process Engineer.. He may be the only Engineer in the company..
    But you are correct in that most of his questions are company/product specific and we cannot answer them..

    For question #1
    I contacted one of our PCB manufacturers when I started panelizing boards and was told that the "most cost effective" layout would be on an 17" x 23" panel or 8.5" x 11.5" panel or 11.5" x 17".
    They start with an 18" x 24" sheet and need 1/2" rail all the way around for their tooling holes.. So the 3 sizes above are a "full usable sheet" or "2 halfs" or "4 quarters of that sheet"..
    I standardized on 8.5 x 11.5 here internally as anything else "bows" too much during processing without specific tooling to mitigate that bowing..
    Anything else just costs more money as they are scrapping more of the full board..

    As to tooling holes.. Our process doesn't need any.. Typically that 1/2" rail all the way around on the full panel size is where the PCB manufacturer puts their tooling holes but thats always cut off by them after they process it so I don't even see them..
    Our boards run down a conveyor.. I place 1/4" minimum rails on the 2 longer edges for it to rest on the conveyor belt..

    V groove clearance..
    The biggest problem is when your components are so close to the v groove that you can't get the depanelizer blade to run down them due to hitting other components.. Some of our parts have flanges that come pretty close to the edge of the board,etc.... But I leave just enough room for the blade to pass.. I would never have ununsed PCB material between v grooves.. thats just wasted space..

    fiducal placement.. 100% up to your company.. manufacturer could care less..

    question #7 of his should be
    yes its best to add those as real holes in the PCB layout software and not just leave them as part of the board outline so they actually show up in the NC drill program.. Just because they may come through on a dxf layer or whatever process you use from CAD to PCB layout doesn't mean they should just stay that way.. I'd always add them as real holes (non-plated through holes probably) in the PCB program. The PCB manufacturer "may" figure it out but if they just process your gerbers without thinking about it you could end up with boards without those holes in them..

    oh and #4.. yes that may be something you can ask the manufacturer to "recommend" but in general they can process any hole size you want (up to their max/min) ..

    #3- yes you can specific exactly where you want the v-scoring/mouse bits,etc... but make sure you don't leave any areas that can't be cut with the depanelizer and you are stuck having to cut them with nippers or something else..
  7. rggmiranda

    Thread Starter New Member

    Jun 6, 2016
    Thanks a lot for your understanding, it is not that my company does not have other engineers, I am developing a project on my own, so no company, and I am not even an engineer, hahah. So most of the things I've learned come from tutorials, things other people made, books, and people like you that answer those questions that I cannot find anywhere else.

    Firstly, maybe i am going the wrong way, should I make the penalization on my own (I am not carrying any test wires out of each board to the panel, in that case it may be more critical) or should I let the manufacturer make it? I actually don't care how they arrange it, the only important things are that they can manufacture it correctly and put it into the PCBA machine in order to install the components. Apart from that it is the same for me.

    If the answer is that I should let the manufacturer make it, should I put feducials in my board? Or they will add the feducials on the rails to ensure proper alignment in the PCBA process?
    I will keep in mind the thing about clarifying those holes in the board, as well should I specify that anything that will be routed out or Vscored in the mechanical layer right?

    Thanks for taking the time to answer with details every question!