IPC-7351 was 100% Surface Mount. 

The 7352 Naming Convention was expanded to include additional information like Thermal Pad size and other missing package data.

IPC-7352 is not a Standard. It's been downgraded to a guideline. 

The real "Standard" for solder joint goals is IPC J-STD-001 Requirements for Soldered Electrical and Electronic Assemblies and it covers both Surface Mount and Through-hole technology.

The reason why I'm asking is because some other IPC standards use a "series" naming convention (e.g. IPC-6010 series with 6011, 6012, etc), where new revisions of each document use A, B, C, instead of changing the base document number.

However, in the case of IPC-7352, it seems like the revision naming went IPC-7351A -> IPC-7351B -> IPC-7352 for some reason. If IPC-7352 is intended to supersede IPC-7351B, does anybody know why they didn't just name it IPC-7351C for consistency?

Thanks for the info. 

I checked it several times... they needed a lot of time to repare the printer, more than six months hahahaha.

Regards,

David

$170

People ask me which Land Pattern Naming Convention is the best? 

I say PCB Libraries naming convention. We thought of everything to remove duplication of footprint names. 

All IPC documents for PCB design have been downgraded from "Standards" to "Guidelines". 

About 50% of all PCB designers don't use IPC documents for PCB design. The other 50% use IPC documents as a guideline but eventually develop their own standards. 

IPC is slowly pulling away from PCB design and focusing on Assembly and Fabrication. IPC J-STD-001 is the leading standard for Assembly Acceptability. All footprints should be IPC J-STD-001 compliant. 

IPC pulled the CID and CID+ training courses. They do have courses on Fabrication and Assembly. 

Select any of the buttons and you will not find any PCB design certification. 

Many thanks for your replies. 

Starting from the end. It has a lot of sense to work with a footprint in a "horizontal" way instead of "vertical" way. Perhaps in a new revision of the standard (in the next 15 years) it will be taken into account.

About the naming convention, I found another difference  comparing two footprints, the lead size is not defined.

IPC-7352 : QFN50P500X400X80-28N

PCB Libraries: QFN28P50_500X400X80L40X25N

I think that it could be useful in some cases. It gives more info about how it is the component. 

The final pad length depends of the component's lead size.

Regards,

David

The IPC-7351B Pin 1 orientation in the Upper Left was a last minute change that should have never been adopted. 

IEC did not agree with the 2005 release Zero Component Orientation introduced in IPC-7351 so in 2007 IEC released IEC 61188-7 to correct the Zero Component Orientation back to what is was in IPC-SM-782. 

The IPC 1-13 Land Pattern committee never got a chance to vote on or approve the new Zero Component Orientation in IPC-7351. It was just slipped in at the last minute. 

This was a huge mistake by the 1-13 Land Pattern Committee chairman to approve this change. 

All rectangular component packages should be rotated to make the long direction "Horizontal" for many reasons. Your computer screen is long in Horizontal. Paper sizes are long in Horizontal. Most PCB designs are long in horizontal. This was never discussed in the final meeting where all the rectangular footprints were changed to the length in the Vertical direction. 

The biggest difference between PCB Libraries and IPC-7352 is the location of the Pin Qty. 

PCB Libraries (IPC-7351C) the pin qty is in the beginning of the footprint name after the component family. 

IPC-7352 the pin qty is at the end of the footprint name (just like IPC-7351B). 

Firstly, Happy New Year! All the best for the new 2023.

Regards,

David

That was fixed and all versions now have that Option file. Footprint Expert will still follow the IPC-7351 mathematical model until if and when the industry accepts IPC-7352, which may take a year or so. But at least we have a workaround in the meantime. 

It's important to note that when you open the IPC-7352.opt file to immediately save as another name because the Enterprise will overwrite the IPC-7352.opt file with every update. 

V23.01 will be released the first week of January 2023 and it will support the new IPC-7352 Footprint Naming Convention in the Console Options.