Anticipating future requirements for high-volume wafer adhesive and coating applications, DEK has enhanced the process capability of its award-winning DirEKt Coat™ technology by a factor of three. With Cp>2@+/- 12.5µm and a 7µm Total Thickness Variation (TTV), DirEKt Coat wafer coating processes effectively address the needs of current and future thinned wafer products.

With the ability to deposit 25µm thick coatings onto wafers as thin as 150µm, the DirEKt Coat wafer backside coating technique enables faster processing times and chip footprint maximization. Traditional die attach adhesive processes such as dispensing, for example, have been unable to deliver the speeds in tandem with the deposit accuracy needed for today’s high-volume manufacturing requirements. Uneven adhesive coverage, chip footprint limitations due to resin bleed and fillet formation and slower, serial deposition speeds are inherent and well-known challenges with traditional die attach processes. DirEKt Coat, on the other hand, provides a parallel process on a proven print platform, depositing materials on wafers as large as 200mm in a single stroke and exponentially – by a factor of 10 – improving processing speeds. Additionally, bondline is controlled to customer specifications and the fillet is eliminated, affording a larger chip area for valuable functionality.

Key to the advance of DirEKt Coat’s process capability is DEK’s new Galaxy Thin Wafer System, which incorporates robust rails and precise transport technology to accommodate a newly engineered, next-generation wafer pallet. The pallet is designed of unique porous materials that ensure thinned wafers remain secure and stable while being imaged during any one of DEK’s proven semiconductor packaging processes. Flat to less than 10µm, the pallet is 400mm square and can accommodate wafers up to 300mm in diameter and as thin as 75µm. The exceptional flatness of the pallet and stability of the system allows the extended Cp and the remarkable 7µm TTV.

“In addition to the unyielding pace of product miniaturization and increased functionality, today’s economic climate is forcing packaging firms to get more out of their processes,” states David Foggie, DEK Semiconductor and Alternative Applications Manager. “Consistent with DEK’s ‘Expect More’ philosophy and technology leadership pledge, we have delivered with DirEKt Coat a future-capable process that offers better performance, improved reliability and faster processing speeds for thinned wafer applications -- all at a 30% lower material cost as compared to current film die attach products.”

It is important to note that enhancements to the DirEKt Coat wafer backside coating process do not come at the expense of any of its formerly well-established benefits, which include reduction of required paste adhesive volumes due to fillet elimination, the ability to pre-manufacture and store wafers until needed, and supply chain efficiency improvements resulting from the use of a single material for multiple requirements as opposed to sourcing film products of varying thicknesses and widths.

The Galaxy Thin Wafer System is capable of hosting a variety of other advanced semiconductor processes including, but not limited to, DirEKt Ball Placement™, thermal interface materials deposition, wafer bumping and encapsulation. Contact DEK to find out more.