Draft IPC-7351C

Why is IPC-7351C not released yet?

During the creation of the first draft, the main committee met face to face for 3-days several times a year and large sections of the draft were worked on by individual members and sent to IPC for update. It wasn’t until the main draft was completed that the sub-committee was invited to webcasts to review the new standard.

When IPC-7351 was first drafted, there was a main committee of dedicated people:

Dieter Bergman (IPC Leader in Standards Technology) – Deceased

Vern Solberg (Technical Consultant Specializing in SMT) – Left the Committee

Gary Ferrari (Ex Vice Chairman)  – Left the Committee

Rainer Taube (FED Director of Standardization) – Left the Committee

John Perry (IPC Liaison) – Left the Committee

Karen McConnell (Current Chairman) – In the process of retiring

Tom Hausherr (President & CEO of PCB Libraries, Inc.) – Still on the 1-13 Land pattern Committee since 1999

Tom, Rainer and Dieter met at IPC headquarters the week of July 14, 2014 for 3 days. We decided to rewrite 7351C into a new updated format because prior updates to IPC-7351 were simply added to the end and Dieter wanted a fresh new rewrite that organized all the component families into special groups according to pin quantity. We wanted to add color to all the graphic images because all previous versions were printed in Black & White. Update the naming convention to include Thermal Pad Sizes and Terminal Lead Sizes which impacted the resulting land pattern. We wanted to add the Zero Orientation “Pin 1 Lower Left” to match the original IPC-SM-782 land pattern standard and the new IEC 61188-7 standard for Pin 1 location. Introduce Rounded Rectangle pad shape and add additional component families. All of these issues were discussed and organized into an outline that clearly described the work that was required for the 7351C rewrite.

Tom left IPC on Thursday July 17, 2014 with the framework and a to do list from Dieter Bergman. Less than one week later, Dieter Bergman passed away on Wednesday July 23, 2014. Using Dieter’s instructions, Tom went to work on 7351C and spent over 1,000 hours to create the original 109-page 7351C draft that was submitted to IPC in June 2015. The sub-committee then met via 1-hour webcasts. The original comments were to change some images and content and Tom went back to the draft for another 6 months to make the updates proposed by the sub-committee. Tom submitted draft 2 of 7351C in May 2016 to IPC. The sub-committee reconvened for 1-hour webcasts for the next 3 years. A recent decision by IPC was made to scrap Tom and Dieter’s 7351C draft and start over from scratch using the IPC-7351B as the base starting point.

A revision to an IPC standard must be drafted, reviewed and approved by a base group of the sub-committee who attends the webcast meetings. Then the final draft is sent out to the entire sub-committee to vote on the revision details. All changes are highlighted so the sub-committee knows all the data that was updated. Since the main sub-committee group does not participate in the regular webcasts, when the final draft goes out, it’s the first time they have seen it. They are given 30 days to vote on the changes. During the voting process, every member has the opportunity to question the changes and submit alternate changes. The draft then goes back to the base sub-committee to address all the questions and additional changes. After the base subcommittee adds the additional comments and recommendations to the standard, a new final draft is created and sent back out for another 30-day committee vote. Normally, this final draft gets approved and then the draft is sent to a typesetter to officially organize the draft into a document that is ready to publish. This process can take up to 3 months or longer depending on the scope of the changes.

Basically, it takes almost a half year to go to publication after the first draft is sent to a sub-committee vote. The IPC-7351C draft is still in committee and sending it out for vote is not on the calendar schedule yet.