PCB Libraries Forum : BGA Pad Size Calculation https://www.PCBLibraries.com/forum/ Mon, 06 Apr 2026 00:04:37 +0000 Sat, 29 Dec 2012 12:33:07 +0000 http://blogs.law.harvard.edu/tech/rss Web Wiz Forums 12.07 360 https://www.PCBLibraries.com/forum/RSS_post_feed.asp?TID=594 <![CDATA[PCB Libraries Forum]]> https://www.PCBLibraries.com/forum/forum_images/PCBLForumLogo.gif https://www.PCBLibraries.com/forum/ <![CDATA[BGA Pad Size Calculation : The BGA &#034;Pad Size&#034;...]]> https://www.PCBLibraries.com/forum/bga-pad-size-calculation_topic594_post2751.html#2751 Author: Tom H
Subject: 594
Posted: 29 Dec 2012 at 12:33pm

The BGA "Pad Size" calculation is 1-Tier, but the Silkscreen Line Width, Ref Des Height and Local Fiducial Size are 3-Tier environment per the upcoming IPC-7351C standard.
 
]]> Sat, 29 Dec 2012 12:33:07 +0000 https://www.PCBLibraries.com/forum/bga-pad-size-calculation_topic594_post2751.html#2751 <![CDATA[BGA Pad Size Calculation : Ok I have been playing with...]]> https://www.PCBLibraries.com/forum/bga-pad-size-calculation_topic594_post2030.html#2030 Author: DaveCowl
Subject: 594
Posted: 18 Oct 2012 at 2:16pm


Ok I have been playing with the software and I have a couple of questions:

My BGA is 18x18 0.8mm pitch with 0.4mm balls

1) It seems to output 0.35mm pads for all of L, N and M - does that make sense?

2) Looking at the table above there is no entry for 0.4 - I tried to add one but to no avail - does it just use the same settings for all sizes 0.35 - 0.45?

3) Did you know that text based HKP files are no longer supported by Mentor Library software? Do you have any fixes for that?

Thanks!
]]> Thu, 18 Oct 2012 14:16:08 +0000 https://www.PCBLibraries.com/forum/bga-pad-size-calculation_topic594_post2030.html#2030 <![CDATA[BGA Pad Size Calculation : I was wondering about that.In...]]> https://www.PCBLibraries.com/forum/bga-pad-size-calculation_topic594_post2029.html#2029 Author: DaveCowl
Subject: 594
Posted: 18 Oct 2012 at 1:44pm

I was wondering about that.

In fact I got to this page because I was trying to find out why the LP Wizard threw out .35 mm pads for my 0.8mm .4mm ball BGA where everyone else says Nominal would be 0.3mm.

In any case I am excited to see this product listed and will give it a try for sure!

Cheers!
]]> Thu, 18 Oct 2012 13:44:46 +0000 https://www.PCBLibraries.com/forum/bga-pad-size-calculation_topic594_post2029.html#2029 <![CDATA[BGA Pad Size Calculation : Thanks Tom. ]]> https://www.PCBLibraries.com/forum/bga-pad-size-calculation_topic594_post1947.html#1947 Author: lalexman
Subject: 594
Posted: 03 Oct 2012 at 9:26am

Thanks Tom.]]> Wed, 03 Oct 2012 09:26:12 +0000 https://www.PCBLibraries.com/forum/bga-pad-size-calculation_topic594_post1947.html#1947 <![CDATA[BGA Pad Size Calculation : Most BGA&#039;s are Collapsing...]]> https://www.PCBLibraries.com/forum/bga-pad-size-calculation_topic594_post1946.html#1946 Author: Tom H
Subject: 594
Posted: 03 Oct 2012 at 9:20am

Most BGA's are Collapsing Balls. In the "PCB Footprint Expert" in "Setup > User Preferences > Terminals > BGA Collapsing Ball" you will see Ball Sizes in the first column and the "Pad Size Reduction" in the second column. The Adj% = the Pad Size Reduction from the Ball Size.
  
 
 
Example: the first Ball Size in the table is 0.60 mm and the Pad Size Reduction calculation is 25%. So 25% of 0.60 mm = 0.45 mm nominal.
 
However, IPC-7351 specifies a tolerance range of +/-0.05 mm so the tolerance range is
  • 0.40 mm Minimum Pad Size
  • 0.45 mm Nominal Pad Size
  • 0.50 mm Maximum Pad Size

The IPC-7351 standard always uses the "Maximum" material condition, so the 0.60 mm Ball Size would require a 0.50 mm Pad Size.

The "PCB Footprint Expert" automatically performs all these calculations for the user.
 
]]> Wed, 03 Oct 2012 09:20:57 +0000 https://www.PCBLibraries.com/forum/bga-pad-size-calculation_topic594_post1946.html#1946 <![CDATA[BGA Pad Size Calculation : Hi,How is the size ofthe...]]> https://www.PCBLibraries.com/forum/bga-pad-size-calculation_topic594_post1945.html#1945 Author: lalexman
Subject: 594
Posted: 03 Oct 2012 at 8:57am

Hi,
 
How is the size of the BGA pad calculated?
 
]]> Wed, 03 Oct 2012 08:57:56 +0000 https://www.PCBLibraries.com/forum/bga-pad-size-calculation_topic594_post1945.html#1945