Why wouldn't the diameter be the gauging factor for length and width IAW with this IPC-6015 requirement?

3.5.3.2 Surface Mount Lands (Area for attachment
such as solder, TAB, conductive adhesive) Defects such
as nicks, dents, and pin holes along the edge of the land
shall not exceed 20% of either the length or width of the
land for Class 2 or Class 3 boards, or 30% for Class 1.
Defects internal to the land shall not exceed 10% of the
length or width of the land for Class 2 or Class 3 boards,
or 20% for Class 1.

Mike Green
Electronic Packaging Design
LMCO-Sunnyvale
408-743-1635
One Corporation, One Team
"If it were easy, they wouldn't call it rocket science."  M. Green, 2009

-----Original Message-----
From: IPC-600-6012 [mailto:[log in to unmask]] On Behalf Of Chris Mahanna
Sent: Friday, March 11, 2011 2:39 PM
To: [log in to unmask]
Subject: EXTERNAL: Re: [IPC-600-6012] bga workmanship criteria for 6015 designs

Joey,
There is no black/white answer.  I personally would be confident is spinning the situation any way that behooves you, as long as you believe the product suits your customer's needs.

When we see 6015 or 6016 we throw a fit (or commotion)  until somebody gives us unambiguous marching orders, because you never know what conformance issues you'll find.

Chris

Chris Mahanna
Robisan Laboratory

-----Original Message-----
From: IPC-600-6012 [mailto:[log in to unmask]] On Behalf Of Jose A Rios
Sent: Thursday, March 10, 2011 12:41 PM
To: [log in to unmask]
Subject: [IPC-600-6012] bga workmanship criteria for 6015 designs

Wondering how some of you would evaluate workmanship of round surface mount lands (BGA's, non-wirebond) for designs calling out fabrication and inspection per IPC 6015 only , and the User does not know what AABUS means....
The closest thing I come to is IPC 6015 paragraph 3.5.3.2, however it's not written in a 'round' context and the boundaries of the edge vs internal area are not explicitely stated.
Do I then go to 6012, 3.5.4.2.2 ???

Joey Rios
PWB & Process Quality Eng'r
Endicott Interconnect Technologies
1093 Clark St.
Endicott, NY 13760
Office: 607-755-5896

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