Electronics Forum | Sat Jun 11 07:51:15 EDT 2016 | davef
Hi Steve ... There are arguments between fabricators and thermal relievers about adding non-connected copper tabs to barrels in hopes of providing thermal relief, but that's not what you're talking about, I believe. I don't foresee an issue moving t
Electronics Forum | Fri Jan 07 09:03:44 EST 2022 | jineshjpr
Hi Everyone, I want to understand what is the copper thickness to be maintained in PTH Barrel hole. Is this same as Fab recommendation of surface finished copper thickness like 25/35/70 microns..??? Is there any specific IPC standards available to un
Electronics Forum | Thu Apr 14 15:27:05 EDT 2022 | ppcbs
If it was ROHS I would suspect copper migration. In my experience an acceptable copper finish should last up to at least 6 reflow cycles. If you have bubbles or blow holes in the solder joint, that is a sign of voids in the walls of the copper barre
Electronics Forum | Thu Aug 10 13:36:48 EDT 2000 | Bob Willis
I recently have been examining multilayer board failures. They are the classic inner connection failure between the foil and the through hole plating which I have not seen in many years. Has any one experienced any issues recently specifically relati
Electronics Forum | Sat Dec 10 07:03:59 EST 2005 | mdemos1
Hi. I am trying to find out the minimum copper thickness I should see on a through hole barrel. The board has 1 ounce copper and the board thickness is 0.062". I am finding thicknesses of 0.6 to 1.2 mils. Thanks, Mike.
Electronics Forum | Fri Oct 08 09:43:27 EDT 2004 | davef
First, don't get too excited about the thermal capabilities of conductive epoxy. An epoxy like DuPont CB-100 increases the amount of heat conducted through the barrel, but many over estimate what it can do. Calculations show for a 0.020" drilled
Electronics Forum | Wed Jun 08 17:35:04 EDT 2016 | slthomas
We all know that whenever possible, we want thermal relief between the barrel/pad and the copper foil to make it easier to properly solder that through hole connector. My question is, assuming there is no connection from the barrel to a copper layer
Electronics Forum | Wed Apr 23 15:17:11 EDT 2003 | Robert
Let me see if I got this right. The OSP in un-plugged vias will break down after subsequent reflows and washes which can result in oxidation. Question: Is there any paper covering oxidation and reliability on such a condition. We are averaging .0007
Electronics Forum | Thu Aug 11 21:43:19 EDT 2005 | Ken
Those temp stickers are useless unless you can stick them into the copper barrel. They can only determine "skin" temperature which has nothing to do with what is happening in the barrels. Your solder is filling the barrel then going cold. I'll gua
Electronics Forum | Wed Sep 27 19:37:32 EDT 2000 | Dave F
Wolfgang is correct. Copper plating thickness of the via barrel walls is a key question you need to answer to troubleshoot this. Tenting is a red herring.
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