Standard Chip Package Case Codes & Dimensions

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   IPC-7351B contains the 3-Tier Density Levels for Land Patterns. 
However, that document is 12 years old and out of date and it took information from the 1987 IPC-SM-782 which is obsolete.

The solder Joint values are way too robust for today's technology. 

Footprint Expert solder joint goals are derived from IPC J-STD-001 standard as it's the main standard that all other standards are built upon. 

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Tom H Members Profile Send Private Message Find Members Posts Add to Buddy List Admin Group Joined: 05 Jan 2012 Location: San Diego, CA Status: Offline Points: 5786	Post Options Post Reply Quote Tom H Report Post Thanks(0) Quote Reply Topic: Standard Chip Package Case Codes & Dimensions Posted: 07 Feb 2022 at 10:01am
	IPC-7351B contains the 3-Tier Density Levels for Land Patterns. However, that document is 12 years old and out of date and it took information from the 1987 IPC-SM-782 which is obsolete. The solder Joint values are way too robust for today's technology. Footprint Expert solder joint goals are derived from IPC J-STD-001 standard as it's the main standard that all other standards are built upon.
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AnonAnon Members Profile Send Private Message Find Members Posts Add to Buddy List New User Joined: 07 Feb 2022 Status: Offline Points: 1	Post Options Post Reply Quote AnonAnon Report Post Thanks(0) Quote Reply Posted: 07 Feb 2022 at 5:41am
	Hi Tom, Please excuse me if you've answered this a thousand times but I'm looking to find which standard defined the "Least" and "Most" limits for each footprint. I can see IPC-SM-782 defines the nominal and references equations in a section 3.3? I am happy to purchase the standard but wanted to ensure it contained the correct information before I purchase. Do the IPC standards only provide the nominal and one has to calculate the limits? Kind regards, David

Tom H Members Profile Send Private Message Find Members Posts Add to Buddy List Admin Group Joined: 05 Jan 2012 Location: San Diego, CA Status: Offline Points: 5786	Post Options Post Reply Quote Tom H Report Post Thanks(0) Quote Reply Posted: 08 Sep 2021 at 8:32am
	Read the User Guide in the main installation folder under "Documents". Charter 1 Footprint Expert Console Options Charter 2 Footprint Expert Calculator Options - Pad Stack Rules Charter 3 Footprint Expert Calculator Options – Drafting Charter 4 Footprint Expert Calculator Options – Fiducials Charter 5 Footprint Expert Toolbar Icons and Menu Options You cannot edit the program Master Options. You need to create your personal option files (as many as you want). Select File > Save As > Your Master Options .opt
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phil.holden Members Profile Send Private Message Find Members Posts Add to Buddy List Advanced User Joined: 14 Aug 2020 Status: Offline Points: 59	Post Options Post Reply Quote phil.holden Report Post Thanks(0) Quote Reply Posted: 08 Sep 2021 at 5:26am
	Hi Tom, For my Enterprise Edition CLOUD Licensed the options under Pad Stack Rules are 'greyed' out. Does this mean that i am unable to control this globally?

Tom H Members Profile Send Private Message Find Members Posts Add to Buddy List Admin Group Joined: 05 Jan 2012 Location: San Diego, CA Status: Offline Points: 5786	Post Options Post Reply Quote Tom H Report Post Thanks(0) Quote Reply Posted: 07 Sep 2021 at 9:08am
	To get 3 or more passive packages to fit into the same Footprint, find parts with the same dimensions and tolerances. If the package dimensions are the same but the tolerances are different, then round the tolerances off so that they are all the same. Rounded Rectangle Pad Shape: You should change your Maximum Radius from 0.25 to 0.15 or 0.10 or something smaller. Change this setting in "Tools > Options > Pad Stack Rules > SMD Corner Rounding > Corner Radius Limit".
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phil.holden Members Profile Send Private Message Find Members Posts Add to Buddy List Advanced User Joined: 14 Aug 2020 Status: Offline Points: 59	Post Options Post Reply Quote phil.holden Report Post Thanks(0) Quote Reply Posted: 07 Sep 2021 at 4:08am
	As is common procedure, especially during these times with supply-chain issues. We try and specify x3 MPNs for all of our passive devices. As there could be 3 substituted parts fitted all with differing terminal lengths. How am i best addressing this when creating a passive library? This is much less of a problem for active parts and connectors that are less 'interchangeable'. Thanks In addition to the above. I have noticed that the terminals sometimes overhang the pads when using 'rounded rectangle'. In your opinion, would this be a problem?

Tom H Members Profile Send Private Message Find Members Posts Add to Buddy List Admin Group Joined: 05 Jan 2012 Location: San Diego, CA Status: Offline Points: 5786	Post Options Post Reply Quote Tom H Report Post Thanks(0) Quote Reply Posted: 02 Jul 2021 at 8:47am
	You need to attach a link to a PDF file zipped or a URL link to the datasheet would be better. Then we can post the Proteus footprint. Are you using the Free V2021 Footprint Expert Pro for Proteus? You could create the footprint in a couple minutes.
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lladam Members Profile Send Private Message Find Members Posts Add to Buddy List New User Joined: 02 Jul 2021 Status: Offline Points: 1	Post Options Post Reply Quote lladam Report Post Thanks(0) Quote Reply Posted: 02 Jul 2021 at 6:26am
	Hi, How to make a Proteus library part of MEGA2560 Pro Mini, or where can find one please. Because the board too small to put many pins on. Thanks

Tom H Members Profile Send Private Message Find Members Posts Add to Buddy List Admin Group Joined: 05 Jan 2012 Location: San Diego, CA Status: Offline Points: 5786	Post Options Post Reply Quote Tom H Report Post Thanks(0) Quote Reply Posted: 25 Mar 2021 at 11:59am
	Use the mfr. recommended pattern for this new upcoming component family. Some manufacturers use a periphery solder joint goal and other use a Toe, Heel and Side pad stack. This is a new Terminal Lead form that has not been fully tested by the world standards like IPC-J-STD-001 for solder joint acceptability.
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Arun7290 Members Profile Send Private Message Find Members Posts Add to Buddy List New User Joined: 10 Mar 2021 Status: Offline Points: 7	Post Options Post Reply Quote Arun7290 Report Post Thanks(0) Quote Reply Posted: 25 Mar 2021 at 11:52am
	Hi Tom, Thanks for the reply. Can we use the above listed package sizes for Wraparound parts as well in the same case code? Because It is mentioned that the above case code dimensions are only for Standard Chips. And I am working on some wraparound packages of the standard case code. Can we use PCB library expert for footprint creation for these parts? Or Is it better to follow the Manufacturer recommended land pattern?