SMD LED 15-22/R6G6C-A32/2T Specification - Multi-Color - 2.0V - 60mW - English Technical Document

1. Product Overview

This document details the technical specifications for a compact, multi-color Surface Mount Device (SMD) LED. The component is designed for high-density mounting on printed circuit boards, enabling miniaturization of end equipment. Its lightweight construction and small form factor make it suitable for applications where space and weight are critical constraints.

The LED is available in two distinct color types based on the semiconductor chip material: a brilliant red (R6) and a brilliant yellow-green (G6). Both variants are housed in a clear resin package. The product is compliant with key industry standards, including RoHS, EU REACH, and halogen-free requirements, ensuring its suitability for modern electronic manufacturing.

2. In-Depth Technical Parameter Analysis

2.1 Absolute Maximum Ratings

The device's operational limits are defined under an ambient temperature (Ta) of 25°C. Exceeding these ratings may cause permanent damage.

• Reverse Voltage (VR): 5 V. A protective circuit is recommended if reverse voltage conditions are possible.
• Continuous Forward Current (IF): 25 mA for both R6 and G6 chips.
• Peak Forward Current (IFP): 60 mA, permissible under pulsed conditions (1/10 duty cycle at 1 kHz).
• Power Dissipation (Pd): 60 mW. This rating considers the total electrical power converted into heat and light.
• Electrostatic Discharge (ESD): Withstands 2000 V per the Human Body Model (HBM), indicating moderate handling sensitivity. Standard ESD precautions are necessary.
• Temperature Range: Operational from -40°C to +85°C; storage from -40°C to +90°C.
• Soldering Temperature: Compatible with lead-free reflow profiles (peak of 260°C for 10 seconds max) and hand soldering (350°C for 3 seconds max).

2.2 Electro-Optical Characteristics

Key performance parameters are measured at Ta=25°C and a forward current (IF) of 20 mA, which is the standard test condition.

• Luminous Intensity (Iv):
  • R6 (Red): Typical range from 45.0 mcd to 112.0 mcd, with a tolerance of ±11%.
  • G6 (Yellow-Green): Typical range from 28.5 mcd to 72.0 mcd, with a tolerance of ±11%.
• Viewing Angle (2θ1/2): A wide 140-degree angle, providing broad illumination suitable for indicator and backlighting applications.
• Wavelength:
  • R6: Peak wavelength (λp) typically 632 nm; Dominant wavelength (λd) between 617.5 nm and 633.5 nm.
  • G6: Peak wavelength (λp) typically 575 nm; Dominant wavelength (λd) between 567.5 nm and 577.5 nm.
• Spectral Bandwidth (Δλ): Approximately 20 nm for both colors, defining the spectral purity.
• Forward Voltage (VF): Ranges from 1.70 V to 2.40 V, with a typical value of 2.00 V for both chip types. This parameter is crucial for current-limiting resistor calculation.
• Reverse Current (IR): Maximum of 10 μA at VR=5V, indicating good junction quality.

3. Binning System Explanation

The luminous output of LEDs naturally varies in production. A binning system categorizes devices based on measured performance to ensure consistency within a batch.

3.1 Luminous Intensity Binning

Bins are defined for each chip type at IF=20mA:

• R6 (Red):
  • Bin P: 45.0 mcd (Min) to 72.0 mcd (Max)
  • Bin Q: 72.0 mcd (Min) to 112.0 mcd (Max)
• G6 (Yellow-Green):
  • Bin N: 28.5 mcd (Min) to 45.0 mcd (Max)
  • Bin P: 45.0 mcd (Min) to 72.0 mcd (Max)

This system allows designers to select the appropriate brightness grade for their application, balancing cost and performance requirements.

4. Performance Curve Analysis

The datasheet includes typical characteristic curves for both the R6 and G6 variants. These graphs visually represent the relationship between key parameters, aiding in circuit design and performance prediction.

• Forward Current vs. Forward Voltage (I-V Curve): This curve is essential for determining the operating point and designing the current-limiting circuitry. The typical Vf of 2.0V serves as the baseline.
• Luminous Intensity vs. Forward Current: Shows how light output increases with current. Operating at the recommended 20mA ensures optimal efficiency and longevity.
• Luminous Intensity vs. Ambient Temperature: Demonstrates the thermal derating of light output. Performance decreases as ambient temperature rises, which is a critical consideration for designs with limited thermal management.
• Spectral Distribution: Illustrates the relative intensity across wavelengths, confirming the peak and dominant wavelength values and the 20nm bandwidth.

5. Mechanical and Package Information

5.1 Package Dimensions

The component features a standard SMD footprint. The dimensional drawing specifies the body size, lead spacing, and overall geometry with a general tolerance of ±0.1 mm. Accurate measurements are vital for PCB pad design and ensuring proper placement during assembly.

5.2 Polarity Identification

The package includes markings or structural features (e.g., a notch, a cut corner, or a dot) to identify the cathode. Correct polarity orientation is mandatory during placement to ensure proper circuit function and prevent damage.

6. Soldering and Assembly Guidelines

6.1 Reflow Soldering Profile

A detailed lead-free temperature profile is provided:

• Pre-heating: 150–200°C for 60–120 seconds.
• Time Above Liquidus (217°C): 60–150 seconds.
• Peak Temperature: 260°C maximum, held for no more than 10 seconds.
• Heating/Cooling Rates: Maximum 6°C/sec heating and 3°C/sec cooling above 255°C.

6.2 Hand Soldering

If manual soldering is necessary:

• Use a soldering iron with a tip temperature below 350°C.
• Limit contact time to 3 seconds per terminal.Use an iron with a power rating of 25W or less.
• Allow a minimum 2-second interval between soldering each terminal to prevent thermal stress.

6.3 Storage and Moisture Sensitivity

The device is packaged in a moisture-resistant bag with desiccant.

• Do not open the bag until ready for use.
• After opening, unused parts must be stored at ≤30°C and ≤60% Relative Humidity.
• The "floor life" after bag opening is 168 hours (7 days).
• If the exposure time is exceeded or the desiccant indicates saturation, a bake-out at 60±5°C for 24 hours is required before reflow.

7. Packaging and Ordering Information

7.1 Standard Packaging

The LEDs are supplied in 8mm wide carrier tape on 7-inch diameter reels. Each reel contains 2000 pieces. Reel, tape, and cover tape dimensions are provided for compatibility with automated pick-and-place equipment.

7.2 Label Information

The packaging label includes several codes for traceability and identification:

• P/N: Product Number (e.g., 15-22/R6G6C-A32/2T).
• QTY: Packing Quantity.
• CAT: Luminous Intensity Rank (Bin Code).
• HUE: Chromaticity Coordinates & Dominant Wavelength Rank.
• REF: Forward Voltage Rank.
• LOT No: Manufacturing Lot Number for traceability.

8. Application Recommendations

8.1 Typical Application Scenarios

• Backlighting: Ideal for dashboard indicators, switch illumination, and symbol backlighting due to its wide viewing angle.
• Telecommunication Equipment: Status indicators and keypad backlighting in devices like telephones and fax machines.
• LCD Flat Backlighting: Can be used in arrays for small, low-profile LCD displays.
• General Purpose Indication: Any application requiring a compact, reliable visual indicator.

8.2 Critical Design Considerations

• Current Limiting: An external series resistor is absolutely mandatory. The forward voltage has a range (1.7V–2.4V), and a small change in supply voltage can cause a large, potentially destructive change in forward current without a resistor. The resistor value (R) is calculated using Ohm's Law: R = (V_supply - Vf_typical) / I_desired. Use the maximum Vf for a conservative design.
• Thermal Management: While power dissipation is low (60mW), maintaining the junction temperature within limits is key to long-term reliability. Ensure adequate PCB copper area or thermal vias if operating at high ambient temperatures or high currents.
• ESD Protection: Implement standard ESD control measures during handling and assembly.
• Repair Limitations: Avoid rework after the initial soldering. If absolutely necessary, use a dual-head soldering iron to simultaneously heat both terminals and minimize thermal stress on the package. Verify post-repair functionality.

9. Technical Comparison and Differentiation

This component's primary advantages stem from its SMD package technology compared to traditional through-hole LEDs:

• Size and Density: The significantly smaller footprint allows for higher component density on PCBs, leading to more compact end products.
• Automation Compatibility: The tape-and-reel packaging is fully compatible with high-speed automated placement machines, reducing assembly cost and improving consistency.
• Weight: The lightweight construction is beneficial for portable and miniature applications.
• Process Compatibility: Designed for standard infrared and vapor phase reflow soldering processes, aligning with modern, lead-free assembly lines.
• Multi-Color Option: Offering two distinct colors (red and yellow-green) in the same mechanical package provides design flexibility.

10. Frequently Asked Questions (FAQ)

10.1 Why is a current-limiting resistor required?

LEDs are current-driven devices. Their I-V characteristic is exponential, meaning a small increase in voltage beyond the forward voltage drop causes a very large increase in current, which can instantly destroy the device. The series resistor makes the circuit voltage-driven, setting a stable and safe operating current.

10.2 Can I drive this LED directly from a 3.3V or 5V microcontroller pin?

No. A microcontroller's GPIO pin has limited current sourcing/sinking capability (often 20-25mA) and is not designed for direct power delivery to loads. Even if the current limit seems sufficient, the lack of a series resistor means any variation in the LED's Vf or the supply voltage could push the current beyond safe limits for both the LED and the microcontroller. Always use a transistor or driver circuit with a proper current-limiting resistor.

10.3 What does the "binning" information mean for my design?

If your application requires consistent brightness across multiple units (e.g., in an array of indicators), you should specify the desired bin code (e.g., P or Q for red) when ordering. Using LEDs from the same bin ensures minimal visible variation in light output. For less critical applications, a mixed bin may be acceptable and more cost-effective.

10.4 How do I interpret the moisture sensitivity instructions?

Plastic SMD packages can absorb moisture from the air. During the high heat of reflow soldering, this trapped moisture can vaporize rapidly, causing internal delamination or "popcorning," which cracks the package. The 7-day floor life and baking instructions are critical controls to remove this moisture before soldering and ensure assembly yield and long-term reliability.

11. Practical Design and Usage Case

Scenario: Designing a multi-status indicator panel. A control unit requires three independent status indicators: Power (Green), Warning (Yellow), and Fault (Red). While this datasheet covers Red and Yellow-Green, the same design principles apply.

1. Circuit Design: For a 5V system and a target current of 20mA per LED, calculate the resistor. Using the typical Vf of 2.0V: R = (5V - 2.0V) / 0.020A = 150 Ohms. For robustness, select the next standard value (e.g., 160 or 180 Ohms) and verify power rating (P = I²R = 0.064W, so a 1/8W or 1/10W resistor is sufficient).
2. PCB Layout: Place the LEDs according to the mechanical drawing. Include polarity markings on the silkscreen. For thermal relief, connect the LED pads to small copper pours.
3. Procurement: Order the Red LEDs (R6) for Fault and the Yellow-Green (G6) for Warning. Specify the desired brightness bin (e.g., Bin P for both) to ensure uniform appearance.
4. Assembly: Follow the reflow profile precisely. Store opened reels in a dry cabinet if not used within 7 days.

12. Technical Principle Introduction

The light emission in these LEDs is based on the AlGaInP (Aluminum Gallium Indium Phosphide) semiconductor material system. When a forward voltage is applied across the p-n junction, electrons and holes are injected into the active region where they recombine. The energy released during this recombination process is emitted as photons (light). The specific composition of the AlGaInP alloy determines the bandgap energy, which directly defines the wavelength (color) of the emitted light. The R6 chip is engineered for red emission (~632 nm), while the G6 chip is tuned for yellow-green emission (~575 nm). The clear resin package acts as a lens, shaping the 140-degree viewing angle and providing environmental protection.

13. Industry Trends and Developments

The market for SMD LEDs like this component continues to be driven by demands for miniaturization, higher efficiency, and broader adoption of solid-state lighting. Key trends influencing this product segment include:

• Increased Efficiency: Ongoing material science and chip design improvements aim to deliver higher luminous intensity (mcd) at the same or lower drive currents, improving overall system energy efficiency.
• Enhanced Reliability: Advancements in packaging materials and die-attach technologies focus on improving thermal performance and longevity, especially for operation in harsh environments or at higher temperatures.
• Standardization and Automation: The move towards standardized package footprints and tape formats continues to streamline automated assembly processes, reducing manufacturing costs.
• Broader Color Gamut and Consistency: Tighter binning tolerances for both wavelength and luminous flux are becoming more common, enabling applications that require high color consistency, such as full-color displays and sophisticated indicator systems.
• Integration: A trend towards integrating control circuitry (like constant current drivers or PWM controllers) within LED packages exists, though for simple indicator types, the discrete component approach remains dominant due to cost and flexibility.

This component represents a mature, well-established technology that balances performance, cost, and manufacturability for a wide range of indicator and backlight applications.