Welcome, Guest
Logo for MyPQ
Describe the feature.
SEMI F47 Services

Interruptions in semiconductor-manufacturing processes can cost as much as $2 million dollars in revenue per day. Such interruptions can be due to voltage sag events caused by ice storms, floods, hurricanes, lightning, failures of utility power-distribution equipment, or other system anomalies. EPRI has a variety of services and products to improve the robustness of your facility to power quality disturbances and help you understand, test, and comply with power quality standards such as the ITIC curve, IEC-61000-4-34, IEC-61000-4-11, and SEMI F47 "Specification for Semiconductor Process Equipment Voltage Sag Immunity."

As you browse our services offering you will see that we offer multiple levels of products and services, including SEMI F47 compliance certification, training, consulting, testing, and power quality audits.

Learn More

For further information about SEMI F47 services, contact Mark Stephens, 865-218-8022, mstephens@epri.com.

PQ Star Compliance Testing

Having conducted power quality tests on hundreds of devices and electrical equipment, EPRI is known worldwide for its expertise in power quality testing. In order to serve the semiconductor industry, EPRI has established a certification program to test manufacturer equipment per established power quality standards. PQ Star certification for the SEMI F47 standard (Specification for Semiconductor Processing Equipment Voltage Sag Immunity) is now available for suppliers of semiconductor equipment. With the PQ Star certification, we offer a third-party verification that the equipment tested meets this important new power quality standard.



EPRI has examined the power schemes and voltage-sag susceptibility of hundreds of industrial systems. Given this experience in diagnosing equipment susceptibility to voltage sags, EPRI engineers can quickly recognize and help correct potential weak links in a system design. Consultation with EPRI in the equipment/design stage can help tool suppliers meet the SEMI F47 voltage-sag standard before the tool is built, or even before the tool is in the prototype stage.

The consulting process involves reviewing tool drawings and subcomponent specifications, creating single-line diagrams of the subject tools, consulting with subcomponent suppliers, and drawing from EPRI's experience to offer suggestions on enhancing power quality. Based on the review, EPRI will make recommendations to help the tool meet the SEMI F47 Standard.



EPRI is an industry leader in power quality training services. With consistently high marks for training class instruction and content from our clients, our instructors present training material in an easy-to-understand format with live demonstrations to help the student grasp the ideas and concepts.

The power quality training classes include an examination of the power quality issues specific to semiconductor equipment. For example, the training classes address the immunity of emergency machine off (EMO) circuits, instrument power supplies, high-voltage DC supplies, RF Generators, and motor drives. The class also discusses various design and configuration strategies for electrical systems to meet SEMI voltage-sag standards. The course also includes an explanation of the relevant voltage sag standards, how to interpret the standards, and how to evaluate equipment to the relevant standard. Power quality training is a must for tool designers and semiconductor manufacturers who want to pass SEMI F47 and improve the reliability of their semiconductor tools and process equipment with respect to voltage sags. The training classes, which can be tailored to the client's specific needs, can be held at our training facility or on-site at the client's location.


Onsite Testing

EPRI is known worldwide as a leader in conducting voltage-sag testing of semiconductor tools. Armed with our unique portable test equipment, our engineers can evaluate the ability of semiconductor tools to meet voltage-sag performance requirements and comply with the SEMI standard F47: "Specification for Semiconductor Process Equipment Voltage Sag Immunity."

Working with the tool supplier, EPRI develops a test plan, conducts the tests, and makes recommendations to make the tool meet SEMI F47. This approach enables tool suppliers to understand the performance of their equipment and to make the necessary changes to meet voltage-sag standards.

EPRI documents the testing with a test report, and if the tool is found to be compliant with SEMI F47, compliance documentation is supplied at no additional charge. We are committed to helping you comply with SEMI F47. We count your success in meeting the SEMI F47 standard as our success as well.


Lab Bench Testing

EPRI offers low-cost certification tests on electrical components in our state-of-the-art power quality laboratory located in Knoxville, Tennessee. Items such as AC and DC drives, relays, contactors, servo drives, PC workstations, and DC power supplies are routinely tested in the lab.

Clients include OEMs who want to install compliant devices in their equipment designs as well as component suppliers who want to certify their devices to meet important power quality standards.


Onsite Power Quality Audit

EPRI has conducted comprehensive power quality audits at dozens of semiconductor facilities worldwide. Utilizing our knowledge base of tool susceptibilities and SEMI F47 solutions, EPRI can help the semiconductor manufacturer improve voltage sag immunity of tools and minimize downtime.

EPRI follows a proven methodology when evaluating semiconductor-manufacturing sites. The typical tasks include:

  • Evaluating the sensitivity of the existing tools based on a review of numerous tool tests that have been conducted by EPRI in the past.
  • Providing specific recommendation for tool hardening and the associated cost for implementing these options at the tool level.
  • Providing recommendations for tool and/or component testing if required.
  • Identifying the proper location for the tool power-conditioning options, taking into account the difficulty in installing power-conditioning options inside the cleanroom or sub-fab.
  • Performing a cost-benefit analysis for these different options, taking into account data from historical voltage-sag monitoring and data on product loss data (if available).

EPRI PQ Audit Approach

When solving issues related to voltage-sag immunity issues for a semiconductor-processing facility, the immunity of all interlocking subsystems must be considered. For example, if the process vacuum pump package shuts down as a result of a voltage sag, the tool operations are likely to halt as well. Furthermore, a shutdown of the process cooling water (PCW) pumps or exhaust system can lead to an immediate shutdown of tooling operations. To ensure that the semiconductor-processing tool continues to operate during typical voltage sags, the tool itself must be robust to power quality variations as well as the support systems.