Applications > Semiconductor > Underfill
Underfill
The underfill process for flip chip packaging presents unique challenges, particularly with designs that include large die, tight gaps, and high-density ball placement. Capillary underfill is traditionally used in these flip chip packages to ensure the highest reliability. The process of capillary underfill is quite simple. The fluid is driven into the gap between the die and substrate via capillary forces. However, this simple dispensing process meets many challenges, particularly with advanced chip designs including die size, gap, bump density, and differing die passivation materials. Specific challenges include wicking speed, fillet height and balance, and underfill adhesion to various materials. All of these challenges are related to the properties of the substrate, underfill fluid, and flip chip device.
Plasma-enhanced surface preparation prior to the underfill process has proven to increase underfill wicking speed, increase fillet height and uniformity, minimize voiding, and improve underfill adhesion. The mechanisms for these improvements include surface energy and surface chemical composition changes.
The figures below display the effect of plasma for underfill fillet height and uniformity.
Adhesion enhancement between the underfill and the polyimide die passivation is illustrated in the figure below. The adhesion strength between the underfill and the die passivation is increased by over a factor of two with plasma.
Related Technical Papers:
Related Products:
AP-1000 Plasma Treatment System
PLC controller with touch screen interface provides industrial reliability and ease of use. Complete system enclosure minimizes footprint.
FlexTRAK™ Plasma Treatment System
The FlexTRAK system offers high-throughput capability of up to 480 substrates or process carriers per hour. Its small chamber volume and proprietary process control enable unmatched short cycle times, while its unique slim structure minimizes floor space requirements.
FlexTRAK-BH™ Plasma Treatment System
The FlexTRAK-BH system is designed for
high-throughput processing of microelectronic boats, trays, or other
flat device carriers, up to 2 boats per plasma cycle.
FlexTRAK-SH™ Plasma Treatment System
The universal architecture of the FlexTRAK-SH system accommodates a wide range of strip sizes in the same system, yielding unmatched production flexibility.
FlexTRAK-WR™ Plasma Treatment System
The FlexTRAK-WR plasma treatment system is designed for
high-throughput processing of semiconductor wafers up to
300mm
(12 in.).
XTRAK Plasma Treatment System
With process capability of up to 180 substrates or carriers per hour, the system's Smart Tune™ management system provides closed-loop control that reduces tuning to less than one second.
PX-Series Plasma Treatment System
PX-Series systems are equipped with an automatic impedance matching network for ease of operation and consistent results.
CS-1701 Anisotropic RIE Plasma System
The CS-1701 system is excellent for metal etching, silicide etching and etching of III-V compounds, anisotropic etching of nitrides, oxides and polyimides.
PM-100 Plasma Treatment System
Designed to be a low-cost, highly effective plasma treatment solution for treating electronic components, printed circuit boards, and medical & life science devices.
Semiconductor Applications Team
Scott Szymanski, Semiconductor Market Manager
Mr. Szymanski works to expand strategic alliances, strengthen partnerships with equipment suppliers, and develop future product offerings tailored to the semiconductor market. With 10+ years of experience at major semiconductor companies, he holds a B.S. degree in Mechanical Engineering from UCLA, and an M.B.A. from the University of Phoenix.
Peter Huang, Semiconductor Applications Engineer
Mr. Huang joined March Plasma Systems in 2006. Prior to his appointment at March he has held a variety of positions in L3 Communications, Raytheon and Texas Instruments. Huang has a BS from Chung Yuan University in Taiwan and a MS from the University of Houston.
Ask the Experts
Semiconductor
The Semiconductor Business Group focuses on plasma processes for advanced semiconductor packaging and assembly (ASPA), wafer level packaging (WLP), microelectromechanical systems (MEMS), data storage devices such as thin film read-write heads (TFH) for hard disk drives, and images sensors. More>>>
Medical Device
The Medical Device Business Group is engaged in providing enhanced product performance, more reliable devices and lower cost processes to companies who manufacture leading edge medical devices including cardiac rhythm management products, catheters, stents, ocular devices, and filter media.
More>>>
Printed Circuit Board
Printed circuit board manufacturers work with our PCB Business Group due to the implementation of new materials technology, and smaller geometries in HDI, flex, and rigid flex applications. More>>>