Yes, thicker copper can be a problem. No, it's not necessarily a problem.

Incomplete info in this question for my thinking.  Would start looking at 
other factors as well.

Relative hole size? Large?
Soldered component in hole vs. simple via?
Copper quality/grain structure?  Just thick with equivalent elongation 
characteristics or thick_weak_large Cu grain because of too rapid copper 
plating?

Perhaps that just intellectual stalling, tho... ;-)


dw


At 06:00 AM 7/24/2007, Ralph Rottnick wrote:
>Lee,
>
>Do you also have any inromation about max Cu thickness in the PTH? In
>the recent past we had some cracks and the min was ok but the max showed
>values aroung .045mm. Our supplier said that the crack was caused due to
>too thick copper. The crack location was on the top just below the Cu
>ring.
>Do you or anybody else has a suggestion how to handle or specify this?
>
>Regards
>Ralph
>
>-----Original Message-----
>From: TechNet [mailto:[log in to unmask]] On Behalf Of Lee parker
>Sent: Friday, July 20, 2007 10:42 PM
>To: [log in to unmask]
>Subject: Re: [TN] Question on plated through holes general
>
>David
>
>I always advise one mil or more in the PTH. Given the non-uniformity
>often seen in the PTH I would also spec the drill quality and the ratio
>of the copper at the top of the hole and in the center.
>
>Best regards
>
>Lee
>
>J. Lee Parker, Ph.D.
>JLP Consultants LLC
>804 779 3389
>
>
>----- Original Message -----
>From: "David Harman" <[log in to unmask]>
>To: <[log in to unmask]>
>Sent: Friday, July 20, 2007 4:23 PM
>Subject: [TN] Question on plated through holes general
>
>
>I have a quick question and our standard that we have maybe an older
>one. We currently use the ANSI/IPC-A-600 Rev E
>
>
>
>
>
>Page 70   Micro section:
>
>
>
>There is a table describing copper plating thickness min, requirements
>
>
>
>
>
>                                                 Class 1
>Class 2                         Class 3
>
>Average Min Thickness              .020mm (0.0008in)        0.025mm
>(0.001 in)       0.025 mm (0.001 in)
>
>
>
>Minimum this area                     .0015 mm( .0006 in)       0.020 mm
>(.0008 in)     0.020mm  (.0008 in)
>
>
>
>
>
>
>
>Can anyone tell me if this still is a current standards for  copper
>plating thickness measurements.
>
>
>
>David Harman
>
>
>
>
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