Christopher, 

Having a little more time to look at your pictures this morning, I noticed several pics such as 006 and 010 that show gross open breakout between the via PAD (foil copper) and via BARREL (plated-up copper). There is no evidence of selective or wave soldering on many of these. The breakout is on the TOP side with no evidence of additional solder applied, therefore my only conclusion is that the root cause was purely the plating issues from the fabricator.

dean



-----Original Message-----

From: TechNet <[log in to unmask]> On Behalf Of Dennis Fritz

Sent: Monday, May 6, 2019 2:38 PM

To: [log in to unmask]

Subject: Re: [TN] Bad Vias - Need help determining the root cause



Do you have a copy of IPC 9121 - troubleshooting guide?  That has a large number of pictures of failed via holes, causes, and remedies.



On Mon, May 6, 2019 at 3:12 PM Christopher Brand <[log in to unmask]> wrote:



> Greetings,

>

> I'm having issues with open vias on a couple of runs of PCBAs and was 

> hoping to get some help on finding a root cause or at least point me 

> in the right direction.  I know that there is lots of knowledge and 

> experience on this forum and I'm hoping someone will say they've seen 

> this before, as my knowledge is rather limited on this.

>

> Here are a few photos of the vias in question.

>

>     https://ludlums.com/software/BadVias/badvia_01.jpg

>     https://ludlums.com/software/BadVias/badvia_02.jpg

>     https://ludlums.com/software/BadVias/badvia_03.jpg

>     https://ludlums.com/software/BadVias/badvia_04.jpg

>     https://ludlums.com/software/BadVias/badvia_05.jpg

>     https://ludlums.com/software/BadVias/badvia_06.jpg

>     https://ludlums.com/software/BadVias/badvia_07.jpg

>     https://ludlums.com/software/BadVias/badvia_08.jpg

>     https://ludlums.com/software/BadVias/badvia_09.jpg

>     https://ludlums.com/software/BadVias/badvia_10.jpg

>     https://ludlums.com/software/BadVias/badvia_11.jpg

>     https://ludlums.com/software/BadVias/badvia_12.jpg

>

> On some, the via barrel has a void in the center and on others the 

> edge of the barrel doesn't connect with the pad, Both issues are 

> causing an open via as you can see in the photos.

>

> I know that the board shop recently changed up their plating tanks 

> (new chemical and power supply).  Could these bad vias be the result 

> of insufficient current in the plating process or some other process?

>

> I'd be much appreciative of any insight this forum could give.

>

> --

> Thank you kindly,

>

> Christopher Brand

> Ludlum Measurements, Inc.

>  501 Oak Street

>  Sweetwater, TX 79556 USA

>  (325) 235-5494 Phone, ext:3318

>





--

Denny Fritz

Consultant

812 584 2687