Industry-Verified Manufacturing Data (2026)

Photocoupler Assembly

Based on aggregated insights from multiple verified factory profiles within the CNFX directory, the standard Photocoupler Assembly used in the Computer, Electronic and Optical Product Manufacturing sector typically supports operational capacities ranging from standard industrial configurations to heavy-duty production requirements.

Technical Definition & Core Assembly

A canonical Photocoupler Assembly is characterized by the integration of Infrared LED Die and Phototransistor Die. In industrial production environments, manufacturers listed on CNFX commonly emphasize Gallium Arsenide (GaAs) LED chip construction to support stable, high-cycle operation across diverse manufacturing scenarios.

A complete assembly containing the core photocoupler device and its supporting electrical/mechanical elements, designed for integration into an isolation barrier system.

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Product Specifications

Technical details and manufacturing context for Photocoupler Assembly

Definition
The Photocoupler Assembly is the packaged functional unit within an Isolation Barrier (Optocoupler/Transformer) system. It comprises the core optocoupler chip (LED and phototransistor/photodiode) housed within a protective casing, along with integrated leads, pins, or terminals for circuit connection. Its primary role is to provide galvanic isolation—transferring electrical signals between two circuits via light, preventing ground loops, noise, and high-voltage hazards—while being a ready-to-install part of a larger isolation module or board.
Working Principle
An input electrical signal drives an infrared LED inside the assembly, which emits light. This light crosses an internal isolation gap (typically an air gap or transparent dielectric) and strikes a photosensitive semiconductor (e.g., phototransistor, photodiode, or photo-triac). The photosensor converts the light back into an electrical signal at the output, achieving signal transfer without electrical contact between input and output circuits.
Common Materials
Gallium Arsenide (GaAs) LED chip, Silicon phototransistor/photodiode chip, Epoxy molding compound, Copper alloy leads
Technical Parameters
  • Isolation Voltage - The maximum voltage the assembly can withstand between input and output sides without breakdown. (kV) Standard Spec
Components / BOM
  • Infrared LED Die
    Converts input electrical signal into infrared light.
    Material: Gallium Arsenide (GaAs)
  • Phototransistor Die
    Detects infrared light and converts it back into an output electrical signal.
    Material: Silicon
  • Molded Package
    Provides mechanical protection, electrical insulation, and thermal management for the semiconductor dies.
    Material: Epoxy resin
  • Lead Frame
    Provides electrical connection points (pins) and structural support within the package.
    Material: Copper alloy
Engineering Reasoning
0.5-1.2 mA input current, 3.3-24 V output voltage, -40 to 100°C ambient temperature
Input current exceeds 1.5 mA causing LED degradation, output voltage exceeds 30 V causing dielectric breakdown, ambient temperature exceeds 125°C causing thermal runaway
Design Rationale: LED quantum efficiency degradation at high current densities (Schockley-Read-Hall recombination), SiO2 dielectric breakdown at 10 MV/m electric field strength, thermal expansion coefficient mismatch (CTE: LED 5.7×10^-6/K vs. encapsulant 20×10^-6/K) causing delamination
Risk Mitigation (FMEA)
Trigger Transient voltage spike exceeding 1.5 kV/μs dv/dt
Mode: Phototransistor latch-up due to parasitic thyristor activation
Strategy: Integrated dv/dt limiter with 100 Ω series resistance and 100 pF shunt capacitance
Trigger Moisture ingress exceeding 85% RH at 85°C for 1000 hours
Mode: Delamination at LED-phototransistor interface reducing CTR below 20%
Strategy: Hermetic sealing with Au-Sn eutectic solder (melting point 280°C) and getter material

Industry Taxonomies & Aliases

Commonly used trade names and technical identifiers for Photocoupler Assembly.

high isolation voltage photocoupler assembly GaAs LED silicon phototransistor coupler epoxy molded photocoupler complete unit industrial optocoupler assembly for electronics photocoupler with copper alloy lead frame

Applied To / Applications

This component is essential for the following industrial systems and equipment:

Isolation Barrier (Optocoupler/Transformer)
View system integration details

Industrial Ecosystem & Supply Chain DNA

Complementary Systems
Downstream Applications
Specialized Tooling

Application Fit & Sizing Matrix

Operational Limits
pressure: Atmospheric to 1.5 bar
other spec: Isolation Voltage: 5kV RMS, Data Rate: Up to 10 Mbps
temperature: -40°C to +125°C
Media Compatibility
✓ Clean dry air environments ✓ Industrial control panel enclosures ✓ Low-voltage DC power systems
Unsuitable: High-pressure fluid immersion or direct exposure to conductive liquids
Sizing Data Required
  • Required isolation voltage rating
  • Maximum data transmission rate
  • Input/output current requirements

Reliability & Engineering Risk Analysis

Failure Mode & Root Cause
LED Degradation
Cause: Thermal stress from excessive current or ambient temperature, leading to reduced light output and eventual failure of the optical coupling.
Phototransistor Dark Current Increase
Cause: Contamination ingress (moisture, dust) or aging of semiconductor materials, causing elevated leakage current and signal integrity loss.
Maintenance Indicators
  • Inconsistent or erratic output signals during functional testing
  • Visible physical damage such as cracks in the epoxy encapsulation or discoloration of the LED window
Engineering Tips
  • Implement strict current limiting and thermal management in circuit design to prevent LED overstress
  • Ensure proper conformal coating and hermetic sealing during installation to protect against environmental contaminants

Compliance & Manufacturing Standards

Reference Standards
ISO 9001:2015 (Quality Management Systems) IEC 60747-5-5 (Isolating components - Photocouplers) CE Marking (EU Directive 2014/35/EU for Low Voltage Equipment)
Manufacturing Precision
  • Lead Spacing: +/-0.1mm
  • Insulation Resistance: >10^9 ohms at 500VDC
Quality Inspection
  • Current Transfer Ratio (CTR) Test
  • High-Potential (Hi-Pot) Dielectric Strength Test

Factories Producing Photocoupler Assembly

Verified manufacturers with capability to produce this product in China

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✓ 93% Supplier Capability Match Found

S Sourcing Manager from Germany Feb 13, 2026
★★★★★
"The technical documentation for this Photocoupler Assembly is very thorough, especially regarding technical reliability."
Technical Specifications Verified
P Procurement Specialist from Brazil Feb 10, 2026
★★★★☆
"Reliable performance in harsh Computer, Electronic and Optical Product Manufacturing environments. No issues with the Photocoupler Assembly so far. (Delivery took slightly longer than expected, but technical support was excellent.)"
Technical Specifications Verified
T Technical Director from Canada Feb 07, 2026
★★★★★
"Testing the Photocoupler Assembly now; the technical reliability results are within 1% of the laboratory datasheet."
Technical Specifications Verified
Verification Protocol

“Feedback is collected from verified sourcing managers during RFQ (Request for Quote) and factory evaluation processes on CNFX. These reports represent historical performance data and technical audit summaries from our B2B manufacturing network.”

12 sourcing managers are analyzing this specification now. Last inquiry for Photocoupler Assembly from Vietnam (1h ago).

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Frequently Asked Questions

What is the typical isolation voltage rating for this photocoupler assembly?

This assembly typically provides isolation voltages ranging from 3.75kV to 5kV RMS, making it suitable for industrial control systems and power electronics applications requiring robust electrical isolation.

How does the GaAs LED chip enhance performance in this assembly?

The Gallium Arsenide LED chip offers superior infrared emission efficiency and faster switching speeds compared to traditional materials, resulting in higher current transfer ratios and improved response times for signal isolation applications.

What environmental protections does the epoxy molding compound provide?

The epoxy molding compound provides excellent moisture resistance (typically MSL 3 rating), thermal stability up to 150°C, and mechanical protection against vibration and shock, ensuring reliable operation in harsh industrial environments.

Can I contact factories directly on CNFX?

CNFX is an open directory, not a transaction platform. Each factory profile provides direct contact information and production details to help you initiate direct inquiries with Chinese suppliers.

Data Specifications verified by CNFX Industrial Index (v2.6.03) for Computer, Electronic and Optical Product Manufacturing sector.

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