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SEMI, the industry association for the semiconductor industry, has developed the SEMI F47 voltage sag immunity standard. Information about SEMI F47 – The Voltage Sag Immunity Standard.

What does SEMI F47 do?

  • SEMI F47 is an industry standard that sets out, in six pages, the requirements for voltage sag immunity in semiconductor fab equipment

    SEMI F47 sets out the required voltage sag tolerance for semiconductor fab equipment

  • The latest edition is SEMI F47-0706 (Reapproved 0812). PSL led the team that wrote this update
  • The main change in SEMI F47-0706 is that the old SEMI F42 testing standard has been eliminated. Instead, IEC 61000-4-34 is used as the test standard

Who Uses The SEMI F47 Standard?

Use IEC 61000-4-34 as the test standard for verifying compliance with SEMI F47.

SEMI F47 suggests that semiconductor manufacturers may use this sag standard whenever they purchase equipment. Major semiconductor manufacturers require compliance, including Texas Instruments, Freescale, IBM, and others.

SEMI F47 says that you must use IEC 61000-4-34 (an international standard that PSL helped to write) to test compliance. It describes safety procedures, processing modes, test sequences, phase connections, test equipment, and reporting requirements. PSL’s sag generators are designed specifically to test according to SEMI F47 and IEC 61000-4-34.

Learn More about SEMI F47

You can purchase copies of these standards from SEMI for $50 each, or contact us and we will send PSL’s application notes and preparing for SEMI F47.

What Are The Requirements?

SEMI F47 graphs sag depth vs. duration, in a similar curve to the CBEMA curve. This F47 graph includes both requirements and recommendations.

In essence, SEMI F47 requires that semiconductor processing equipment tolerate voltage sags on their ac power line. Specifically, they must tolerate sags to 50% for up to 200 ms, sags to 70% for up to 0.5 seconds, and sags to 80% for up to one second. In addition to these requirements, SEMI F47 recommends that equipment tolerate sags to 0% for one cycle, sags to 80% for 10 seconds, and continuous sags to 90%, but these are not part of the requirements.

Useful SEMI F47 Links

Power Standards Lab
980 Atlantic Ave.
Alameda, California 94501
TEL: ++1.510.522.4400
US: 1.888.SEMI.F47 or 1.888.736.4347

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