Capillary-driven micro flows for the underfill process in microelectronics packaging

Dynamic Filling Characteristics of a Capillary Driven Underfill Process in Flip-Chip Packaging

This study investigates the dynamic flow characteristics of capillary-driven underfill flows in a flip chip package. In the present study, we used two different bump arrays using Sn-2.5Ag solder balls with 80 mm and 100 mm diameters on commercially available flip chips, which have different pitches of 150 mm and 180 mm. First, we measured surface tension and viscosity with a rheometer and a ten...

Plasma for Underfill Process in Flip Chip Packaging

Driven by the fast growing demand for smaller, faster, and higher I/O electronic devices, flip chip technology has attracted significant attention in the electronic packaging industry. Flip chip is a proven packaging technology due to its high performance, reduced form factor, and greater I/O density. In successful flip chip packaging, the underfill process plays an important role because it ca...

Analysis and Modeling of Underfill Flow Driven by Capillary Action in Flip-chip Packaging

Underflow Process for Direct-Chip-Attachment Packaging

-In flip-chip packaging an underfill mixture is placed into the chip-to-substrate standoff created by the array of solder bumps, using a capillary flow process. The underfill mixture is densely filled with solid silica particles to achieve the desired effective coefficient of thermal expansion. Thus during the flow process the underfill mixture is a dense suspension of solid particles in a liqu...

Encapsulation Technology for 3 D Stacked Packages

The continuing demand for yet smaller and lighter electronic devices requires micro packaging where shrinkage in the geometry of the substrates as well as decrease of the area of the die is needed. Higher device and circuitry integration of the silicon die, finer pitch of fully populated arrays interconnections are examples of how the industry is meeting these miniaturizations demand. Today tec...