FC-770A AERA FC-7700 Series Analog Mass Flow Controller

AERA FC-770A | Analog Flow Control for Semiconductor Gas Systems

The FC-770A is an analog mass flow controller from the AERA FC-7700 Series. It is designed for precise flow regulation in semiconductor process equipment using compatible non-corrosive gases.

Its 3-digit analog design combines a compact installation footprint with a 20-pin card-edge electrical connection. The controller accepts a 0–5 VDC command and provides a corresponding analog output.

With full-scale ranges from 10 sccm to 5 slm, the FC-770A supports different gas delivery requirements. Its elastomer-sealed construction is intended for applications where the process gas and sealing materials are compatible.

01 | Control Performance at a Glance

• Flow range: 10 sccm to 5 slm, depending on the configured full-scale range.
• Accuracy: ≤ ±1% of full scale.
• Repeatability: ≤ ±0.2% of full scale.
• Linearity: ≤ ±0.5% of full scale.
• Control range: 2–100% of full scale.
• Zero stability: Less than 0.5% of full-scale flow over one year.
• Response: Less than 2 seconds for flow settling between set points.

Engineering note: Accuracy and repeatability are specified as percentages of full scale, not percentages of the instantaneous reading. This distinction matters when selecting a low-flow range. For example, a 1% FS accuracy specification represents a larger absolute flow deviation at a 5 slm range than at a 500 sccm range.

02 | Gas Path and Sealing Construction

The wetted construction uses stainless steel 316(L), PTFE, and magnetic stainless steel. Elastomer seals are available in fluoroelastomer or chloroprene rubber configurations.

• Wetted materials: Stainless steel 316(L), PTFE, and magnetic stainless.
• Seal materials: Fluoroelastomer or chloroprene rubber.
• Valve mechanism: Solenoid valve.
• Valve position: Normally open.
• Leak integrity: Maximum 1 × 10^-6 atm-cc/sec (He).
• Heating: Standard unheated configuration.

Seal selection should follow the actual process gas, temperature, and cleaning requirements. Do not assume that one elastomer option is suitable for every gas. Oxygen service requires separate compatibility and cleanliness verification.

03 | Pressure Conditions and Installation Envelope

Pressure conditions must be evaluated separately during system design. The differential pressure requirement is not interchangeable with the inlet pressure rating.

• Required differential pressure: 7–40 psiD.
• Normal operating pressure: 70 psig.
• Maximum inlet pressure: 140 psig.
• Operating temperature: 5–45°C (41–113°F).
• Dimensions (H × W × D): 122 × 32 × 124 mm.
• Weight: 1.0 kg (2.2 lb).

Confirm the available pressure drop across the controller under actual operating conditions. A suitable inlet pressure alone does not guarantee the required differential pressure. Also verify that downstream pressure changes will not compromise the available control margin.

04 | Analog Interface and Electrical Requirements

The FC-770A uses a 0–5 VDC analog command and output interface. Electrical integration requires a compatible AERA 20-pin card-edge connector.

• Command signal: 0–5 VDC.
• Output signal: 0–5 VDC.
• Connector: AERA 20-pin card-edge connector.
• Positive supply: +15 VDC ±2%, 25 mA.
• Negative supply: -15 VDC ±2%, 180 mA.
• Maximum power consumption: 3.1 W.

Before connecting the controller, check the host equipment's pin assignment and signal reference. Do not rely on connector shape alone to establish electrical compatibility. Verify supply polarity, grounding, command scaling, and output scaling against the applicable wiring documentation.

05 | Where the FC-770A Fits in a Process

This model is intended for semiconductor equipment requiring analog gas flow regulation. Typical applications include:

• CVD: Regulating compatible process gas delivery to deposition chambers.
• PVD: Controlling gas flow used in physical vapor deposition systems.
• Etching: Managing non-corrosive gas flow in compatible process configurations.
• Diffusion: Supporting controlled gas delivery during thermal processing.
• Ion implantation: Providing analog flow control in supporting gas systems.
• Sputtering: Regulating compatible gas feeds for sputtering equipment.

Gas compatibility must be confirmed for each application. The listed material construction does not establish universal compatibility with every process gas.

06 | Selection and Commissioning Checks

1. Confirm the full-scale range. Match the configured range to the required process flow. Avoid selecting a range substantially larger than the normal operating demand.
2. Verify gas calibration. Confirm the calibration gas and gas correction requirements before comparing indicated flow with the process target.
3. Check pressure conditions. Confirm the differential pressure remains within the specified 7–40 psiD requirement.
4. Inspect the electrical interface. Verify the 20-pin connector, ±15 VDC supply, analog signal wiring, and signal reference.
5. Review seal compatibility. Confirm the installed elastomer type is suitable for the intended gas and operating environment.
6. Check the valve response. Verify the flow settles correctly after set-point changes under the actual pressure and gas conditions.

07 | Technical Specifications

08 | Frequently Asked Questions

Q1: Can the FC-770A be installed as a direct replacement for another analog MFC?

Not automatically. Check the mounting dimensions, gas connections, full-scale range, connector pinout, supply requirements, and analog signal scaling. Two controllers with similar footprints may use different electrical assignments or calibration data. Complete these checks before installation.

Q2: What should be checked if the displayed flow does not match the process flow reference?

First, confirm that both instruments use the same engineering units and reference conditions. Then check the gas calibration, full-scale range, pressure conditions, and analog output scaling. A difference in gas calibration can produce a consistent offset even when the controller operates normally.

Q3: Why can flow become unstable after a gas line or regulator is changed?

A regulator change can alter the pressure available across the controller. Check upstream pressure stability, downstream backpressure, regulator capacity, and line restrictions. Confirm that the differential pressure remains within the required range before adjusting the control system.

Q4: What does the normally-open valve configuration mean during a power interruption?

The valve is specified as normally open. Its mechanical default position is therefore open when the actuating power is removed. Consider this behavior in the equipment's gas isolation and safety design. Do not treat the controller as a fail-closed shutoff device.

Q5: How should a replacement unit be verified before returning equipment to production?

Compare the replacement's range, gas calibration, seal material, connector wiring, and power requirements with the installed configuration. After installation, perform a leak check and verify zero output, several flow set points, and response stability. Follow the equipment manufacturer's approved commissioning procedure before releasing the gas system.

9 | Ordering Information

When requesting an AERA FC-770A, provide the complete model number and available configuration details. Include the required full-scale flow range, process gas, seal material, pressure conditions, and connector requirements.

For replacement or retrofit projects, photographs of the nameplate and electrical connector can help verify the configuration before ordering.

Contact us for pricing, availability, and technical assistance for the AERA FC-770A.

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