Aug 20, 2009 
Pre-applied – also known as wafer-applied – underfill (WAU) systems have garnered much attention. However, to date, few formulations have delivered the performance required to move the process into mainstream semiconductor packaging applications such as wafer-level CSPs and flip-chip technology. Historically, pre-applied underfills have suffered from challenges such as material integrity issues during the wafer dicing process and long-term material stability. LORD Corporation’s WAU resolves many of these challenges, offering a material that, among other benefits, exhibits no cracking from dicing stress. Initially deposit thickness uniformity was also a challenge, but the capabilities of the Galaxy system overcame this hurdle, proving the superior functionality of the platform and ultimately becoming the deciding factor for LORD Corporation’s selection of DEK.
“In early development, we were spin coating the WAU onto the wafers, but were getting total thickness variations (TTVs) across the surface that ranged anywhere from 10% to 20%, which was simply unacceptable,” explains Candice Brannen, Senior Scientist at LORD Corporation. “We then engaged DEK’s advanced development group to analyze our materials utilizing a printing process and a 50 micron coating thickness. This combination yielded a surface variation of roughly 3%, which is exceptional.”
DEK’s Galaxy platform has long been recognized as the system of choice for next-generation processes and robust high-volume manufacturing requirements. With alignment capability of 2 Cpk @ +/- 12.5µm and throughput of 45 wafers per hour, the Galaxy affords high-speed, precise and repeatable performance for a variety of applications that range from traditional SMT through to the most advanced semiconductor packaging processes. What’s more, when equipped with DEK’s ultra flat wafer pallet technology, the Galaxy delivers the stability and control required for processing today’s delicate wafer products.
“The expertise and support that we received from the DEK team was superb,” comments LORD Corporation Sales and Marketing Manager, Jim Greig. “When we started this project we did not intend to purchase a machine, but the DEK staff was extremely agile, responsive and accommodating. The results speak for themselves. Our experience was so positive that we made the decision to expand our in-house lab capabilities and have invested in a DEK Galaxy to facilitate future development work.”
Currently, LORD Corporation’s WAU, which has been proven in process at thicknesses ranging from 20 microns up to 100 microns, is in the qualification stage at several customers with excellent results thus far. For more information on LORD WAU solutions, contact Jim Greig from LORD Corporation at jim_greig@lord.com. Details regarding DEK’s Galaxy mass imaging platform are available online at http://www.dek.com.
About DEK
DEK is a global provider of advanced materials deposition technologies and support solutions including printing equipment platforms, stencils, precision screens and mass imaging processes used across a wide range of applications in electronics pre-placement subassembly, semiconductor wafer manufacture, and alternative energy component production. For more information, visit DEK at http://www.dek.com.
About LORD Corporation
Headquartered in Cary, North Carolina with sales in excess of $700 MM, LORD Corporation is a privately-held company that designs, manufactures and markets devices and systems to manage mechanical motion and control noise and vibration; formulates, produces and sells general purpose and specialty adhesives and coatings; and develops products and systems utilizing magnetically responsive technologies. For the electronics industry, LORD serves as a diversified technology company providing high value-added materials to niche markets. LORD builds on its more than 80 year history with a track record of successful long-term partnerships with technology leaders in industries ranging from aerospace to automotive, electronics to industrial heavy equipment.
With manufacturing in nine countries and offices in more than 15 major business centers, LORD Corporation employs more than 2,500 worldwide. Visit http://www.lord.com/ for more information.
