The long-term field reliability of PBGAs (presumably on FR-4) depends on a
number of dimensional and material parameters as well as the severity of the
use environment. Also ball height (C5 vs. high-melt solder balls) and
attachment (solder-mask defined (SMD pads vs. NSMD)) play a role. The biggest
impact will however come from whether or not there are solder joints
underneath the die in the PBGA. For perimeter populated PBGAs there is little
in terms of reliability problems, for fully populated PBGAs it will depend on
the type of die-attach (rigid vs. soft).
For info on accelerated testing you should follow IPC-SM-785, Guidelines for
Accelerated Reliability Testing of Surface Mount Solder Attachments, and for
Design for Reliability information Section 7 in J-STD-013.
I will be giving a workshop at NEPCON West that deals with these issues. The
workshop title is "Practical Design and Prediction Methods for Surface Mount
Solder Joint Reliability". The objectives of this course are to make the
participants familiar with the underlying technical issues; provide insights
in the relative importance of product quality resulting from workmanship
standards and process controls, and focused 'Design for Reliability;' give
them an appreciation of the reliability pitfalls in the design, testing, as
well as environmental stress screening (ESS) of electronic assemblies; and to
present state-of-the-art, but simple to apply, tools for the 'Design for
Reliability.' The attendees of the course will have an understanding of the
solder behavior under load and fatigue which is necessary for the successful
design, manufacture, and testing of electronic assemblies, including those
newer components like BGAs, CGAs, TSOPs, etc. Processing issues to achieve
the consistent solder joint quality necessary to assure reliability will also
be discussed.
The information presented has been included in the industry documents
IPC-SM-785, 'Guidelines for Accelerated Reliability Testing of Surface Mount
Solder Attachments', IPC-D-279, 'Design Guidelines for Reliable Surface Mount
Technology Printed Board Assemblies', ANSI/IPC J-STD-012, 'Implementation of
Flip Chip and Chip Scale Technology', and ANSI/IPC J-STD-013, 'Implementation
of Ball Grid Array and Other High Density Technology'.
Werner Engelmaier
Engelmaier Associates, Inc.
Electronic Packaging, Interconnection and Reliability Consulting
23 Gunther Street
Mendham, NJ 07945 USA
Phone & Fax: 201-543-2747
E-mail: [log in to unmask]
***************************************************************************
* TechNet mail list is provided as a service by IPC using SmartList v3.05 *
***************************************************************************
* To unsubscribe from this list at any time, send a message to: *
* [log in to unmask] with <subject: unsubscribe> and no text. *
***************************************************************************
* If you are having a problem with the IPC TechNet forum please contact *
* Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask] *
***************************************************************************
|
