Electronics Assembly Knowledge, Vision & Wisdom
Evaluation and Qualification of Reworkable Underfill Materials
Evaluation and Qualification of Reworkable Underfill Materials
Study investigates, evaluates and qualifies reworkable underfill materials for BGAs, Leadless devices, QFNs, and other devices to improve reliability.
Materials Tech

Materials Tech programs cover topics including:
Adhesives, Chemicals, Cleaning Solutions, Coatings, Components, Design, Embedded Technology, Fasteners, Finishes, Flex Circuits, Flip Chip, Fluxes, PC Fab, Solders, Solder Masks, Solder Paste and more.
Submit A Comment
Comments are reviewed prior to posting. You must include your full name to have your comments posted. We will not post your email address.

Your Name

Your Company

Your E-mail

Your Country

Your Comment

Authored By:
Jeffrey Colish, Luis Lopez, and Carlo Viola
Northrop Grumman Corporation

A study was performed to investigate, evaluate and qualify new reworkable underfill materials to be used primarily with ball grid arrays (BGAs), Leadless SMT devices, QFNs, connectors and passive devices to improve reliability. The supplier of the sole source, currently used underfill, has indicated they may discontinue its manufacture in the near future. The current underfill material is used on numerous circuit card assemblies (CCAs) at several sites and across multiple programs/business areas.

In addition, it is used by several of our contract CCA suppliers. The study objectives include evaluation of material properties for down select, dispensability and rework evaluation for further down select, accelerated life testing for final selection and qualification; and process development to implement into production and at our CCA suppliers. The paper will describe the approach used, material property test results and general findings relative to process characteristics and rework ability.

This effort helped to identify and down select reworkable underfill materials to replace a current underfill that may be discontinued. Although we do not have final results, the preliminary results obtained from the accelerated life testing (ALT) on test articles underfilled with suppliers 3 and 4 materials are promising.

The project methodology to survey available underfill materials from the different adhesive manufacturers, to validate the material properties and to incorporate these new materials into a qualified BGA underfill dispensing process, was fully developed and validated during this effort. The evaluation process included, not only a compatibility assessment of these new materials against the current underfill material, but the design and fabrication of a test board for a performance comparison.

The approach used for process and rework development, to down select these reworkable underfill candidates can be used to evaluate similar materials and processes. The lessons learned are many and they provide a common perspective to approach replacement material evaluations for qualified products that may be subjected to the constraints of diminishing material sources (DMS).

Initially Published in the IPC Proceedings

No comments have been submitted to date.
Free Newsletter Subscription
Every issue of the Circuit Insight email newsletter will bring you the latest information on the issues affecting you and your company.

Insert Your Email Address

Directory Search

Program Search
Related Programs
bullet Durable Conductive Inks for Robust Printed Electronics
bullet Conformal Coating - Performance Comparison Environmental Testing
bullet Hybrid Conformal Coatings for Mitigating Tin Whiskers
bullet Characterizing Thermal Fatigue Reliability of Third Generation PB-Free Alloys
bullet Jetting Fine Lines onto 2D and 3D Electronic Packages
bullet Residues on Probing PCBAS-Consistent Connections Across No-Clean Fluxes
bullet Conformal Coatings in Preventing Resistor Silver Sulfide Corrosion
bullet Why Uneven Conformal Coating?
bullet Aerosol Jet Printing of Conductive Epoxy for 3D
bullet Dispensing EMI Shielding Materials: An Alternative to Sputtering
More Related Programs