Wafer-Level Chip-Scale Package Favors Small-Form-Factor ASICs

April 26, 2004

A fully qualified, high-performance, low-power and small-form-factor wafer-level chip-scale package (W-CSP) developed by Oki Semiconductor satisfies a wide range of ASIC design demands. Targeting chip sizes from 2 by 2 mm up to 8 by 8 mm with pin...

Roger Allan

According to the company, the package has the same pin count of other packages, yet it's half the size of a fine-pitch BGA package and one-fourth the size of a fine-pitch QFP package. Also, it weighs just one-fourth as much as a BGA and one-tenth as much as a QFP. An 8- by 8-mm package weighs just 0.08 g. And, the lead time is 30% shorter than the lead time for conventional packages.

The W-CSP is made of a molded halogen-free resin with a thickness as small as 0.4 mm. Oki claims that the package has a reliability rating that's as reliable, if not moreso, than conventional packages. It has passed JEDEC Level 1 moisture sensitivity levels, eliminating the need for a dry pack. Pin pitches of 0.8, 0.65, 0.5, 0.4, and 0.3 mm are available. Lead-free solder is optional.

The W-CSP is available with a lead time of 10 to 14 days for trial production runs and volume production quantities. Pricing will range from $0.45 to $0.75 per pin.

Oki Semiconductor www.okisemic.com/us (408) 720-1918

See associated figure.

About the Author

Roger Allan

Roger Allan is an electronics journalism veteran, and served as Electronic Design's Executive Editor for 15 of those years. He has covered just about every technology beat from semiconductors, components, packaging and power devices, to communications, test and measurement, automotive electronics, robotics, medical electronics, military electronics, robotics, and industrial electronics. His specialties include MEMS and nanoelectronics technologies. He is a contributor to the McGraw Hill Annual Encyclopedia of Science and Technology. He is also a Life Senior Member of the IEEE and holds a BSEE from New York University's School of Engineering and Science. Roger has worked for major electronics magazines besides Electronic Design, including the IEEE Spectrum, Electronics, EDN, Electronic Products, and the British New Scientist. He also has working experience in the electronics industry as a design engineer in filters, power supplies and control systems.

After his retirement from Electronic Design Magazine, He has been extensively contributing articles for Penton’s Electronic Design, Power Electronics Technology, Energy Efficiency and Technology (EE&T) and Microwaves RF Magazine, covering all of the aforementioned electronics segments as well as energy efficiency, harvesting and related technologies. He has also contributed articles to other electronics technology magazines worldwide.

He is a “jack of all trades and a master in leading-edge technologies” like MEMS, nanolectronics, autonomous vehicles, artificial intelligence, military electronics, biometrics, implantable medical devices, and energy harvesting and related technologies.