SOURCE: Antares Advanced Test Technologies

July 03, 2008 17:50 ET

New RF QFN Socket, the Z-Socket, From Semiconductor Test Supplier Antares Achieves Matched Impedance During Test of High-Speed ICs With Conventional Spring Probes

Antares to Showcase the Z-Socket, Line of Integrated Test Cell Consumables at SEMICON West Booth 7211, West Hall - Level 1

VANCOUVER, WA and SANTA CLARA, CA--(Marketwire - July 3, 2008) - Engineers at Antares Advanced Test Technologies have recently examined the relationship between gold plated spring-probe contactors and ground block design and their combined effect on matched impedance during test of high-speed RF integrated circuits (ICs) in developing the company's latest QFN test socket, the Z-Socket.

RF chipmakers that require matched impedance of 50 Ohms at the socket level to test high-speed devices often use short interconnect technologies such as conductive elastomer and offset stamping contactors in place of longer spring probes to improve signal integrity -- effectively trading interconnect mechanical performance for electrical performance, according to Ila Pal, an Antares program manager.

Pal said that Antares began work on the Z-Socket, or impedance socket, to combine the reliability of traditional spring-probe technology with the impedance-matching functionality of shorter interconnects at higher price points.

"There's sometimes a misconception in the industry that the only way to optimize signal integrity is to use the shortest interconnect," Pal said. "Our work has really shown that employing longer, more durable interconnects doesn't have to compromise the system's electrical performance."

Pal added that the Z-Socket employs spring probes to allow it to accommodate variable or warped packages better than shorter interconnects that generally can't establish co-planarity with warped packages. The short interconnects, he said, endure fewer cycles and create more maintenance-related downtime than spring probes.

"We wanted to use a proven interconnect technology and then fine-tune the entire socket system to meet a real need from the RF community," Pal said.

Antares' test data on the new RF QFN test socket with spring probes and an impedance-matching system demonstrate that its signal-integrity performance is equal to that of sockets with conductive elastomer or offset stamping contactors, according to Pal.

"The data we have is really quite conclusive," Pal said. "The longer spring probes, when placed in a fully optimized socket system, more than deliver from an electrical standpoint."

The Z-Socket achieves impedance of 50 Ohms via a proprietary impedance-matching system that optimizes the diameter, length and material properties of the spring-probe contacts and composition and location of the ground block in ceramic PEEK housing. Antares' patent-pending system centers on embedding the spring probes into the copper ground block to connect the ground pad of the QFN package to the PCB.

Pal said that Antares' impedance-matching system for the Z-Socket can be fine-tuned to meet various impedance requirements, including 75 Ohms.

Engineers from Antares will showcase the Z-Socket at this year's SEMICON West at booth 7211 in the West Hall, Level 1.

The Z-Socket's key specifications include an electrical length of 2.57 mm, current carrying capability of 2.3 amp/90 degrees C, pitch range (minimum) of 0.5 mm, temperature range of -40 to 125 degrees C, force of 25 gf @ 0.38 mm, dielectric constant of 3.5 and dielectric strength of 19.7 kV/mm.

For more information, please contact one of Antares' regional representatives:

About Antares Advanced Test Technologies

Antares Advanced Test Technologies is reducing the cost of semiconductor test by concentrating on high-sensitivity areas such as yield and the integration of test disciplines, focusing on customer support, delivering innovative technologies and offering a single point of contact for semiconductor test cell requirements, including burn-in sockets, test sockets, ATE consumables and thermal management solutions. Antares is headquartered in Vancouver, Wash. and has design, development and manufacturing locations in Suzhou, China; Yokohama, Japan; Phoenix and Gilbert, Ariz.; and Milpitas and Santa Clara, Calif.

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