Hi Victor- No, I don't know of direct IPC standards on this. I'd think it would be in the specification for your laminate (such as FR4). The laminates probably list a maximum resin weight percentage. But that would be for the whole shebang, obviously that falls apart when you get into a small enough area. Just how small are you talking about? Reasons for it happening: -High flow pre-preg with very uneven metal loading from a vertical perspective. (Unbalanced layer-to-layer unevenness results in warpage, but if you had a whole lot of metal with edges all ending in the same spot on each layer, then the resin would be displaced to the areas with less copper.) -Cutouts in pre-preg to accommodate cavities or other special structures. -Poorly made laminate/prepreg. In that case, it should fail the spec on resin weight percentage. Wayne From: [log in to unmask] [mailto:[log in to unmask]] Sent: Friday, July 25, 2014 1:26 PM To: [log in to unmask]; Wayne Thayer Cc: [log in to unmask] Subject: RE: PWB, rich epoxy area witin laminate Wayne, Are you aware of any IPC STDs which cover this anomaly or even bench marking? I hope PWB/PCB gurus will chime in on this topic. Victor, -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Wayne Thayer Sent: Thursday, July 24, 2014 3:44 PM To: [log in to unmask] Subject: Re: [TN] PWB, rich epoxy area Resin rich will be weaker, lower dielectric constant, more subject to cracking, higher coefficient of expansion. Actual effect on reliability/product use depends on how close the design relies on "normal" laminate specs. -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Victor Hernandez Sent: Thursday, July 24, 2014 3:37 PM To: [log in to unmask] Subject: [TN] PWB, rich epoxy area Fellow TechNetters: Can a rich epoxy area/site within a PWB laminate be harmful. What can happen and what could be the reason for the rich epoxy area? Where can I fins supporting literature in IPC STDs and or bench marking. Victor, ______________________________________________________________________ This email has been scanned by the Symantec Email Security.cloud service. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________