The pad size in the terminal density level 'L'

Message Topic Search Topic Options Post Reply Create New Topic Printable Version Translate Topic

   Today, I use the 2021.09 version to generate a SC89 footprint (using the SOFL package). I found the pad size in 'L' density is generated according to the nominal size. Assuming a pin with such width specification:
MIN = 0.23, NOM = 0.28, MAX = 0.33

Then the pad width generated is 0.28. Is it designed like this, or it's a bug?

Thanks.

Author	Message Topic Search Topic Options Post Reply Create New Topic Printable Version Translate Topic
diverger Members Profile Send Private Message Find Members Posts Add to Buddy List Active User Joined: 15 Mar 2013 Status: Offline Points: 36	Post Options Post Reply Quote diverger Report Post Thanks(0) Quote Reply Topic: The pad size in the terminal density level 'L' Posted: 06 Jul 2021 at 8:51pm
	Today, I use the 2021.09 version to generate a SC89 footprint (using the SOFL package). I found the pad size in 'L' density is generated according to the nominal size. Assuming a pin with such width specification: MIN = 0.23, NOM = 0.28, MAX = 0.33 Then the pad width generated is 0.28. Is it designed like this, or it's a bug? 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: 5718	Post Options Post Reply Quote Tom H Report Post Thanks(0) Quote Reply Posted: 06 Jul 2021 at 9:50pm
	You would have to send us an email with a FPX file attached with a step by step instruction to reproduce a bug. Are you using the default solder joint goals and mfr. tolerances and package tolerances? Lots of questions. I have a datasheet. Would that work? https://www.vishay.com/docs/71612/sc89_6leads.pdf
	Stay connected - follow us! X - LinkedIn

diverger Members Profile Send Private Message Find Members Posts Add to Buddy List Active User Joined: 15 Mar 2013 Status: Offline Points: 36	Post Options Post Reply Quote diverger Report Post Thanks(0) Quote Reply Posted: 06 Jul 2021 at 11:20pm
	Yes, I use the default solder joint goals and mfr, etc. The datasheet of the part is https://www.onsemi.com/pdf/datasheet/nta4153n-d.pdf, the SC-89 package.

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: 5718	Post Options Post Reply Quote Tom H Report Post Thanks(0) Quote Reply Posted: 07 Jul 2021 at 9:00am
	It's perfect. The pad width can not be any smaller than the nominal lead width.
	Stay connected - follow us! X - LinkedIn

diverger Members Profile Send Private Message Find Members Posts Add to Buddy List Active User Joined: 15 Mar 2013 Status: Offline Points: 36	Post Options Post Reply Quote diverger Report Post Thanks(0) Quote Reply Posted: 07 Jul 2021 at 5:49pm
	I thought the pad should be equal or greater than the max. specification. Now if the pad is generated as nominal width. we must rely on the courtyard to make sure the pad won't get connected with other, right? 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: 5718	Post Options Post Reply Quote Tom H Report Post Thanks(0) Quote Reply Posted: 07 Jul 2021 at 9:09pm
	Not in the "Least Density Level". Least = minimum pad size, but still functional and manufacturable. Use Nominal Density or change the "Tools > Options > Terminals > Surface Mount > Flat Lead > Least > Side" You have the controls to create your PCB library.
	Stay connected - follow us! X - LinkedIn