IPC-7352 vs. PCB Libraries footprint naming option

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   I'm building out a new footprint library and I have the option to choose between IPC-7352 vs. PCB Libraries footprint naming convention option in FPE.
From the bits and pieces I’ve read on this forum, it sounds like PCB Libraries was based on the IPC-7351C standard that was never released.

Does anybody know the history of why IPC chose to abandon the IPC-7351C naming convention and come up with a different one in IPC-7352?

As I dig into IPC-7352 spec, I’m seeing a bunch of stuff that doesn’t really make sense to me, and I’m trying to figure out if there are good reasons for these changes, or if they just rushed out the standard without thinking too hard about it.

For example, in IPC-7352 BGA, CGA, LGA, etc has the pin qty in front (BGA + Pin Qty + …), but other component families like QFN have the pin qty at the end of the footprint name (QFN + … - Pin Qty). These kinds of inconsistencies make no sense to me, but maybe there is a good reason? It does not seem to be explained anywhere in the standard. Does anybody know if the land pattern committee published the rationale for WHY they chose the naming convention in IPC-7352?

In comparison, PCB Libraries consistently puts the Pin Qty at the front of the name, which seems to make a lot more sense, at least to me (e.g. "QFN64").

Essentially, I'm trying to figure out whether adopting the IPC-7352 naming convention is a bad idea. Usually I try to follow the IPC standard, but I'm finding all sorts of small issues, typos, etc in IPC-7352 which is making me question if the standard was rushed out with a bunch of unresolved issues.

One example: 3.4.3.2 recommends using the suffix "L" for lead tolerance (e.g. "L20" for 0.2mm lead tolerance), while the following 3.4.3.3 section recommends using the same suffix "L" for lead geometry (e.g. "L60X24" for 0.60 mm X 0.24 mm lead geometry). FPE simply chooses to ignore lead tolerance and will not include this in the footprint name to avoid any confusion, but this seems like an issue with the IPC-7352 spec.

For anybody who has adopted the IPC-7352 naming convention, what has been your experience? Have you run into any issues with naming conflicts between parts? Is it better just to stick with the PCB Libraries naming convention that seems to have been working well for years now?

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cgnd Members Profile Send Private Message Find Members Posts Add to Buddy List Active User Joined: 24 Mar 2021 Status: Offline Points: 28	Post Options Post Reply Quote cgnd Report Post Thanks(0) Quote Reply Topic: IPC-7352 vs. PCB Libraries footprint naming option Posted: 6 hours 31 minutes ago at 10:53pm
	I'm building out a new footprint library and I have the option to choose between IPC-7352 vs. PCB Libraries footprint naming convention option in FPE. From the bits and pieces I’ve read on this forum, it sounds like PCB Libraries was based on the IPC-7351C standard that was never released. Does anybody know the history of why IPC chose to abandon the IPC-7351C naming convention and come up with a different one in IPC-7352? As I dig into IPC-7352 spec, I’m seeing a bunch of stuff that doesn’t really make sense to me, and I’m trying to figure out if there are good reasons for these changes, or if they just rushed out the standard without thinking too hard about it. For example, in IPC-7352 BGA, CGA, LGA, etc has the pin qty in front (BGA + Pin Qty + …), but other component families like QFN have the pin qty at the end of the footprint name (QFN + … - Pin Qty). These kinds of inconsistencies make no sense to me, but maybe there is a good reason? It does not seem to be explained anywhere in the standard. Does anybody know if the land pattern committee published the rationale for WHY they chose the naming convention in IPC-7352? In comparison, PCB Libraries consistently puts the Pin Qty at the front of the name, which seems to make a lot more sense, at least to me (e.g. "QFN64"). Essentially, I'm trying to figure out whether adopting the IPC-7352 naming convention is a bad idea. Usually I try to follow the IPC standard, but I'm finding all sorts of small issues, typos, etc in IPC-7352 which is making me question if the standard was rushed out with a bunch of unresolved issues. One example: 3.4.3.2 recommends using the suffix "L" for lead tolerance (e.g. "L20" for 0.2mm lead tolerance), while the following 3.4.3.3 section recommends using the same suffix "L" for lead geometry (e.g. "L60X24" for 0.60 mm X 0.24 mm lead geometry). FPE simply chooses to ignore lead tolerance and will not include this in the footprint name to avoid any confusion, but this seems like an issue with the IPC-7352 spec. For anybody who has adopted the IPC-7352 naming convention, what has been your experience? Have you run into any issues with naming conflicts between parts? Is it better just to stick with the PCB Libraries naming convention that seems to have been working well for years now?