DEK wafer bumping and ball placement solutions

Citation

(2005), "DEK wafer bumping and ball placement solutions", Soldering & Surface Mount Technology, Vol. 17 No. 4. https://doi.org/10.1108/ssmt.2005.21917dad.002

DEK wafer bumping and ball placement solutions

DEK wafer bumping and ball placement solutions

Keywords: Electronics industry

DEK, the world leader in high-accuracy mass imaging has developed break through wafer bumping and ball placement solutions for today's most demanding packaging applications. By utilizing efficient screen printing techniques and enabling technologies such as enclosed print head material deposition, DEK has successfully implemented cost-effective and yield-enhancing bumping and ball placement process alternatives to traditional methods (Plate 1).

Plate 1 DEK has developed breakthrough wafer bumping and ball placement solutions

“Customers are looking for reduced costs on several levels,” says Richard Heimsch, president of DEK International. “Manufacturers want lower initial equipment investment, long-term ownership and tooling costs. DEK has responded to these requirements by delivering a flexible platform that can deposit paste and place solder flux and solder balls, while handling devices in different input formats.”

For bumping at the wafer and substrate levels, DEK employs a simple print and reflow method that allows for single stroke, unlimited bump quantity with bump height targets of 80 to 150 microns on pitches of 150 up to 500 microns. This technique requires strict application of design rules when creating the stencil, which is generally electroformed. Also imperative to the success of this method is the design of the bond pads so as to allow sufficient contact area to achieve good solder joint strength for a given stand-off. The enabling technologies that allow printing platforms to be configured to meet these semiconductor packaging requirements include automated wafer handing systems, DEK's Vortex™ clean-room compatible paperless cleaning systems and its fully enclosed print head technology, ProFlow^®, which delivers outstanding paste volume transfer and uniformity.

When pitch and bump size is appropriate, placing instead of forming solder bumps at the wafer and substrate levels is an alternative. DEK's DirEKt Ball Placement™ solution can place solder balls as small as 0.3 mm in diameter onto substrates or wafers, with fine-pitch accuracy and first-pass yields consistently better than 99 percent. Using DEK's sophisticated flux imaging technology, flux is deposited at each interconnect site. Then, the fully enclosed ProFlow ball transfer head guides each solder ball directly to the surface of the stencil and a controlled placement force seats each ball into the flux. Cycle time is incredibly fast and completely independent of I/O count.

“DEK's mass imaging technologies are effectively delivering the increased performance and lower investment costs that today's packaging specialists are demanding,” concludes Heimsch. “We continue to pioneer new, innovative packaging process solutions that meet next-generation requirements and are changing the way semiconductor manufactures think about accurate material deposition methods.”

For more information on DEK's Wafer Bumping processes or any of its innovative semiconductor packaging solutions, visit: www.dek.com