IPC-7351C ?
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Category: General
Forum Name: General Discussion
Forum Description: general topics not related to other forums
URL: https://www.PCBLibraries.com/forum/forum_posts.asp?TID=732
Printed Date: 31 Oct 2025 at 2:51pm
Topic: IPC-7351C ?
Posted By: Matthew Lamkin
Subject: IPC-7351C ?
Date Posted: 04 Dec 2012 at 9:19am
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Hi, What version of IPC-7351 does the "PCB Library Expert" currently follow? Also do you know when rev C is being released? I cannot find much about it on the IPC standard status page, only a Power Point. Thank you. |
Replies:
Posted By: Tom H
Date Posted: 04 Dec 2012 at 10:46am
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The changes to the IPC-7351C are in a Power Point presentation located here and it's called "PCB Design Optimization Starts in the CAD Library" - http://www.pcblibraries.com/forum/pcb-library-optimization-presentation-free_topic468.html" rel="nofollow - http://www.pcblibraries.com/forum/pcb-library-optimization-presentation-free_topic468.html The IPC-7351 committee just completed a 2 month review of all the changes and they accepted all of them. Right now, the ball is in IPC's court to implement the changes. I believe that IPC is going to delegate the changes to various team members for incorporation. After the content is completed, the 1st draft goes out for committee vote for 30-days. At the end of 30-days, the committee submits all the typos and revisions that they want added or fixed and then the final draft of the standard goes back out for 30-day committee and hopefully for final approval. Then the document goes to type setting which normally takes a month and then out to the print shop where the initial order is placed for the prototype copies. The committee members get the prototype copies and after they approve, mass production starts and the publication goes on sale. So my best guess is that IPC-7351C will be available to purchase in Q1 2014. ------------- Stay connected - follow us! https://twitter.com/PCBLibraries" rel="nofollow - X - http://www.linkedin.com/company/pcb-libraries-inc-/" rel="nofollow - LinkedIn |
Posted By: Tom H
Date Posted: 04 Dec 2012 at 11:17am
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I forgot to mention that the only signifigant difference in the PCB Footprint Expert between IPC-7351B and IPC-7351C is the rotation. IPC-7351B Zero Component Orientation is Pin 1 Upper Left. IPC-7351C introduces two Zero Component Orientations.
The PCB Footprint Expert follows "Level B" because it's also the international IEC 61188-7 standard. If you want to use the IPC-7351B Zero Component Orientation, there is a "Default Preference" file called IPC-7351B_DefaultPreferences.dat |
Posted By: Mattylad
Date Posted: 04 Dec 2012 at 12:10pm
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Using V33 IPC-7351B_DefaultPreferences.dat still displays as pin 1 lower left. Changing the user preferences to point the default preferences to the above file saving it and exiting the program. Restarting and checking the defaults are set to the above file - all OK so far. Open SM.fpx and look at an SOIC. Pin 1 is bottom left. So it seems its not quite matching rev B ? |
Posted By: Tom H
Date Posted: 04 Dec 2012 at 3:17pm
How about a new "Batch Create" window that pops up prior to the CAD interface window and contains dropdown menus for -
This way you can change anything you want prior to Batch Creation of your FPX file. Would this work? Can anyone think of anything else to add? |
Posted By: Matthew Lamkin
Date Posted: 05 Dec 2012 at 2:20am
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How about we just set the above settings so that whatever method we use to export our components they are already set? That IMO would work best. Yes the ability to make the change for each output would be useful but not as the only way to do it. If I have 30 components to check dimensions of then output and am going to do it one at a time I certainly would not want to have to change the settings each time. Also if I select a load of components to batch output it would be nice to be able to change to least when I'm in nominal at the point that I output them, but only because I have forgotten - but I would not want this to be the only way - I might want to output several different batches in the same format without having to set them up each time. IMO There is no need to try and make this more complicated than it needs to be, to have several path to the settings with several different types of settings - a single setup dialogue (that configures all) that a user can get to from either the main menu or the batch create that controls how all output are set is more than adequate. |
Posted By: Tom H
Date Posted: 05 Dec 2012 at 11:23am
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The "IPC-7351B_DefaultPreferences.dat" produces the correct Zero Component Orientation (Pin 1 Left or Upper Left). In order to see the correct results the User Preference Environment Setting must be Least, Nominal or Most. If the "Setup > User Preference" Environment Setting is set to "User" then the "UserPreferences.dat" takes over. So if you are using UserPreferences.dat, to fix the problem, you need to update the UserPreferences.dat file to reflect the Zero Component Rotation of the "IPC-7351B_DefaultPreferences.dat" file. There are 2 ways to easily fix this. The best way is to open "Setup > User Preferences > Component > select a Component Family > select the << button to move the Pin 1 location from Default to User" This is how to update SOIC/SOP/CFP Zero Component Orientation -  The other way to fix the issue is to select the User dropdown menu in each component family and set the Pin 1 location to match the Default. Also, I mentioned that we could possibly change the program to a single set of Preferences and after talking to customers and the FPE programmers, they want to keep the current process as it's far more flexible and offers more features than a single set of Preferences. Personally, I would define all my settings using the Default Preferernce Editor and then set my environment to "Nominal". This way I can easily change environments from Least to Most to Nominal and get all the Drafting and Rule settings that I want. i.e.: Once you create a good Default Preference file and load it, there is no reason to ever apply Environment "User". This is very simple but difficult to understand by some users. |
Posted By: Matthew Lamkin
Date Posted: 06 Dec 2012 at 2:58am
You can say that again. here, let me.
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This is very simple but difficult to understand by some users.Posted By: jameshead
Date Posted: 06 Dec 2012 at 4:20am
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I didn't get this bit at first either and it took a few e-mails between Tom and I before I "got" it. |