Best To Send CAD Data, Not Gerber Files
Panelization and de-panelization are becoming more common on the PCB assembly floor. Panelization is used to process increasingly smaller boards through assembly steps to deal with the growing OEM demand for smaller, more compact products.
Known as processing PCBs in array format, panelization keeps small boards attached to each other in a multiple boards format, as shown in Fig. 1. There are two primary reasons for using an array scheme. One is to increase throughput; the other is to help the manufacturing process to keep a small board in a larger panel size, which helps in assembly and then in testing.
On the other hand, de-panelization is the removal of the various small PCBs from the panel. Two ways are used to do that. Either a saw blade or a manual type tool can be used to remove a board from the panel. A V score set up is often used to remove material from the top and bottom of a PCB. But material is retained in the center to keep the boards in an array format until the assembly and testing are completed.
There are several important things to know about this area. Check out our article in PCD&F/Circuits Assembly Magazine and get more details. For the time being, here are some tips and hints to help get you started in this PCB assembly category.
- OEMs must provide the PCB assembly house a complete CAD data package and not just Gerber data.
- CAD data package shows where actual component boundaries are to be located and size of those components. This critical data is not visible in Gerber data.
- Components can be seen thanks to CAD data. But it also provides a road back to the PCB design to search for and locate flaws.
- With only Gerber data and net lists prevent PCB assembly personnel from troubleshooting such issues as opens or shorts during power ground short testing.
- A complete CAD data package includes the schematic, CAD layout file the PCB designer has generated based on the schematic, Gerber files, and bill-of-material or BOM.
- Get a handle on ODB++ files similar to a CAD platform because the industry has begun using it and it’s becoming mainstream.
There are multiple benefits to the OEM for providing the assembly house with a full set of CAD data. Just to name a few, there are stability, time, and thoroughness. A universal platform that major software companies support avoids potential issues associated with a software tool’s ability to load a given format. This particular problem is slowly fading away with the emerging shift towards harnessing the ODB++ format.
The time associated with loading Gerbers, drills, drawings, net list files, and so on are time consuming. An ODB file running various analyses can be virtually instantaneous. Thoroughness comes in to play downstream in the process when one might need to start troubleshooting or isolating a potential open or short, or perhaps even consider how to optimize panelization.