PCB Libraries Forum : Fabrication https://www.PCBLibraries.com/forum/ Wed, 08 Apr 2026 22:39:47 +0000 Thu, 30 Sep 2021 10:41:50 +0000 http://blogs.law.harvard.edu/tech/rss Web Wiz Forums 12.07 30 https://www.PCBLibraries.com/forum/RSS_topic_feed.asp?FID=55 <![CDATA[PCB Libraries Forum]]> https://www.PCBLibraries.com/forum/forum_images/PCBLForumLogo.gif https://www.PCBLibraries.com/forum/ <![CDATA[Fabrication : Oblong BGA Pads Instead of Round For 1st Row]]> https://www.PCBLibraries.com/forum/oblong-bga-pads-instead-of-round-for-1st-row_topic2988_post11918.html#11918 Author: toshas
Subject: Oblong BGA Pads Instead of Round For 1st Row
Posted: 30 Sep 2021 at 10:41am

In reference design special shape (narrow oblong instead of round) of a 1st row pads is applied. 

How often this trick is used? What is about soldering result for a volume production?

BGA has 0.46 pitch, without this trick 3 mils width/separation is required, with it 3.7 mils width/separation is acceptable.

These traces and pads are most complicated place in particular PCB design and defines fabrication requirements for a whole project.

Default pad size is a 10mils, oblong pad has 7 mils x 13 mils dimensions.

How it can be calculated for proper soldering? 

Is it possible to change size even more (6 mils x 14 mils) to get low-cost 4 mils width/separation requirement for fabrication?

Many thanks!

 



 
]]> Thu, 30 Sep 2021 10:41:50 +0000 https://www.PCBLibraries.com/forum/oblong-bga-pads-instead-of-round-for-1st-row_topic2988_post11918.html#11918 <![CDATA[Fabrication : IPC-2221 & 2222 and Through-hole Pad Stacks]]> https://www.PCBLibraries.com/forum/ipc2221-2222-and-throughhole-pad-stacks_topic2586_post10876.html#10876 Author: npassey
Subject: IPC-2221 & 2222 and Through-hole Pad Stacks
Posted: 17 Aug 2020 at 6:45am

Hi Tom,
Thanks for this.  I have that tool, and earlier, I went to the toolbox and tried the "Hole Size Calculator".  For some reason I did not see the Padstack Calculator, which answers my question.

Have a great day!
]]> Mon, 17 Aug 2020 06:45:31 +0000 https://www.PCBLibraries.com/forum/ipc2221-2222-and-throughhole-pad-stacks_topic2586_post10876.html#10876 <![CDATA[Fabrication : IPC-2221 & 2222 and Through-hole Pad Stacks]]> https://www.PCBLibraries.com/forum/ipc2221-2222-and-throughhole-pad-stacks_topic2586_post10875.html#10875 Author: Tom H
Subject: IPC-2221 & 2222 and Through-hole Pad Stacks
Posted: 12 Aug 2020 at 9:19am

We have a free software program called "Library Expert Pro" that supports Xpedition & high quality 3D STEP. 

In that free program is 144 Calculators for standard component packages for both Surface Mount and Through-hole families. 

There is also a Toolbox with a Pad Stack Calculator. You can either enter the terminal lead length width or the hole size length and width and it will calculate all the pad stack details. 

Download and install the free Library Expert Pro here (no license required) - 
www.pcblibraries.com/downloads 


]]> Wed, 12 Aug 2020 09:19:29 +0000 https://www.PCBLibraries.com/forum/ipc2221-2222-and-throughhole-pad-stacks_topic2586_post10875.html#10875 <![CDATA[Fabrication : IPC-2221 & 2222 and Through-hole Pad Stacks]]> https://www.PCBLibraries.com/forum/ipc2221-2222-and-throughhole-pad-stacks_topic2586_post10874.html#10874 Author: npassey
Subject: IPC-2221 & 2222 and Through-hole Pad Stacks
Posted: 12 Aug 2020 at 8:56am

Xpedition.

thanks,
]]> Wed, 12 Aug 2020 08:56:06 +0000 https://www.PCBLibraries.com/forum/ipc2221-2222-and-throughhole-pad-stacks_topic2586_post10874.html#10874 <![CDATA[Fabrication : IPC-2221 & 2222 and Through-hole Pad Stacks]]> https://www.PCBLibraries.com/forum/ipc2221-2222-and-throughhole-pad-stacks_topic2586_post10873.html#10873 Author: Tom H
Subject: IPC-2221 & 2222 and Through-hole Pad Stacks
Posted: 12 Aug 2020 at 8:03am

What CAD tool do you use for PCB layout? 

We have something interesting in development that will help you. 

]]> Wed, 12 Aug 2020 08:03:15 +0000 https://www.PCBLibraries.com/forum/ipc2221-2222-and-throughhole-pad-stacks_topic2586_post10873.html#10873 <![CDATA[Fabrication : IPC-2221 & 2222 and Through-hole Pad Stacks]]> https://www.PCBLibraries.com/forum/ipc2221-2222-and-throughhole-pad-stacks_topic2586_post10872.html#10872 Author: npassey
Subject: IPC-2221 & 2222 and Through-hole Pad Stacks
Posted: 12 Aug 2020 at 7:58am

Tom, that annular ring info sounds good.

But my question was not about the padstack for a slot. I'm talking about calculating the milled slot hole.
We are using custom metal shields in various locations that will be soldered to the PCB.  I have the dimensions of the tab, and I can create a slot that will fit, but I'm mostly estimating.

Your discussion above about the hole size for round and rectangular pins made me think to post this question here.  Should I just extend the definition for pins into long, rectangular tabs and use something like IPC-2222B Table 9-5 (Figure 9-3) to calculate the slot hole?




Thanks,
]]> Wed, 12 Aug 2020 07:58:38 +0000 https://www.PCBLibraries.com/forum/ipc2221-2222-and-throughhole-pad-stacks_topic2586_post10872.html#10872 <![CDATA[Fabrication : IPC-2221 & 2222 and Through-hole Pad Stacks]]> https://www.PCBLibraries.com/forum/ipc2221-2222-and-throughhole-pad-stacks_topic2586_post10871.html#10871 Author: Tom H
Subject: IPC-2221 & 2222 and Through-hole Pad Stacks
Posted: 11 Aug 2020 at 7:12pm

Slotted holes require 2x annular ring due to the drill and drag process. 

]]> Tue, 11 Aug 2020 19:12:18 +0000 https://www.PCBLibraries.com/forum/ipc2221-2222-and-throughhole-pad-stacks_topic2586_post10871.html#10871 <![CDATA[Fabrication : IPC-2221 & 2222 and Through-hole Pad Stacks]]> https://www.PCBLibraries.com/forum/ipc2221-2222-and-throughhole-pad-stacks_topic2586_post10870.html#10870 Author: npassey
Subject: IPC-2221 & 2222 and Through-hole Pad Stacks
Posted: 11 Aug 2020 at 6:52pm

Hello Tom,

This is great info about drilled holes and padstacks.

Is there a standard or guidance for PCB slot size?  What's the best way to take the dimensions of the tab that will be soldered in a PTH slot and calculate the width X length for the slot?

Thanks,
-Nathan
]]> Tue, 11 Aug 2020 18:52:25 +0000 https://www.PCBLibraries.com/forum/ipc2221-2222-and-throughhole-pad-stacks_topic2586_post10870.html#10870 <![CDATA[Fabrication : IPC-2221 & 2222 and Through-hole Pad Stacks]]> https://www.PCBLibraries.com/forum/ipc2221-2222-and-throughhole-pad-stacks_topic2586_post10827.html#10827 Author: AndrasP91
Subject: IPC-2221 & 2222 and Through-hole Pad Stacks
Posted: 20 Jul 2020 at 4:48am

Hi there,

Thank you for the info!
]]> Mon, 20 Jul 2020 04:48:20 +0000 https://www.PCBLibraries.com/forum/ipc2221-2222-and-throughhole-pad-stacks_topic2586_post10827.html#10827 <![CDATA[Fabrication : PCB fabrication update]]> https://www.PCBLibraries.com/forum/pcb-fabrication-update_topic2633_post10750.html#10750 Author: 4mcpcb
Subject: PCB fabrication update
Posted: 27 May 2020 at 7:30am

Hi guys,
This is smith from 4MCPCB.
Newbie here on this awesome forum.

]]> Wed, 27 May 2020 07:30:54 +0000 https://www.PCBLibraries.com/forum/pcb-fabrication-update_topic2633_post10750.html#10750