Specification for Voltage Dip Immunity Test of Semiconductor Equipment

【What is SEMI F47 Voltage Sag?】

To mitigate electromechanical risks in the semiconductor industry, a wide range of preventive and management measures are adopted.

One of the most typical requirements is that SEMI F47 voltage sag certification is specified as a mandatory criterion for equipment procurement by fabs.

Here we will explain what SEMI F47 voltage sag is, so that equipment manufacturers can gain a clear understanding before implementation.

   Specific Test Specifications:

Apply 50% of the rated voltage between each phase of the power input. For a 50 Hz system, the cycle duration is 20 ms, 10 cycles, and the test duration per time is 200 ms. Observe whether the equipment experiences abnormal conditions such as tripping or interruption.

Apply 70% of the rated voltage between each phase of the power input. For a 50 Hz system, the cycle duration is 20 ms, 25 cycles, and the test duration per time is 500 ms. Observe whether the equipment experiences abnormal conditions such as tripping or interruption.

Apply 80% of the rated voltage between each phase of the power input. For a 50 Hz system, the cycle duration is 20 ms, 50 cycles, and the test duration per time is 1000 ms. Observe whether the equipment experiences abnormal conditions such as tripping or interruption.

In short, it verifies whether the equipment can withstand voltage fluctuations at 50%, 70%, and 80% of the nominal input voltage.

The SEMI F47 IPC voltage sag test system is a dedicated device supplied by Power Standards Lab (PSL) in the United States. Test personnel must hold qualified certifications.

The IPC voltage sag generator is developed in accordance with relevant international standards. It can generate accurate and controlled voltage fluctuations on AC circuits, mainly used to test the immunity of various loads to voltage sags according to standards, and provide technical data to improve their immunity. Various test specifications such as SEMI F47 are pre‑configured in the test instrument.

1. Main Functions and Features

1.1 The IPC industrial voltage sag generator is a mobile electrical device.

1.2 It can generate voltage sags and swells for single‑phase, three‑phase delta, and three‑phase wye systems without any external transformers.

1.3 The sag generator can operate at any nominal voltage from 100 V to 480 V.

1.4 The sag generator can supply a continuous RMS current of 200 A per phase and a peak current of 600 A per phase, with a transient peak impulse current driving capability of 1000 A.

1.5 The phase‑to‑phase voltage sags generated by the sag generator are true phase‑to‑phase sags, not simulated by two phase‑to‑neutral sags.

1.6 Automatic setting of test conditions.

2. Technical Parameters and Performance Requirements

2.1 Voltage sag and swell characteristics:

The sag generator can produce voltage sags from 0–100% of the operating voltage at 2.5% intervals, and voltage swells from 100–125% at 2.5% intervals, as well as complete voltage interruptions with high impedance.

During a voltage sag, the voltage variation of non‑sagged phases is within ±10%.

The duration of voltage sags and swells is programmable:

the minimum duration is 1 cycle (20 ms at 50 Hz), and the maximum duration is at least 30 seconds, adjustable in steps of 1 cycle.

The sag generator can initiate voltage sags at a programmable phase angle (0–360°, in 5° steps).

No voltage or current discontinuities shall occur at the start and end of voltage sags or swells.

In accordance with the measurement method defined in IEC 61000‑4‑34, voltage sags and swells apply to phase‑to‑neutral or phase‑to‑phase conditions.

2.2 Data Recording

Sampling resolution: 12 bits or higher.

The voltage sag generator shall record the following waveforms and RMS values:

all phase‑to‑phase and phase‑to‑neutral input voltages,

phase‑to‑phase and phase‑to‑neutral output voltages,

phase input currents and phase output currents.

Recording shall include data before, during, and after each voltage sag and voltage swell.

Test graphs and curves shall be generated automatically by the equipment.

Test Plot For Voltage and Current Waveforms:

Voltage waveform 10 cycle sag to 50％

Voltage waveform 25 cycle sag to 70％

Voltage waveform 50 cycle sag to 80％ 

ECMG has the most experienced SEMI professional team in China. We are equipped with test facilities complying with SEMI F47 requirements, as well as qualified and experienced engineers. We assist equipment manufacturers in completing voltage sag testing in accordance with the SEMI F47 standard.

All testing and technical support are provided locally, enabling us to respond to customer requirements promptly.