LED 3.2x1.6x0.7mm Yellow-Green Datasheet - Voltage 1.8V-2.4V - Power 72mW - Dominant Wavelength 562.5-575nm - Technical Documentation

1. Product Overview

This document provides a comprehensive technical specification for a surface-mount yellow-green LED designed for general indication and display applications. The device adopts a standard 3.2mm x 1.6mm x 0.7mm package (commonly known as 3216 or 1206 footprint) and is fabricated using a high-efficiency yellow-green chip. With an extremely wide viewing angle of 140 degrees, it is suitable for applications requiring uniform illumination across a broad area. The LED is RoHS compliant and meets Moisture Sensitivity Level 3 (MSL3), ensuring compatibility with standard SMT assembly processes. Key features include low power consumption, excellent color stability, and electrostatic discharge (ESD) protection up to 2000V (HBM). The device is available in multiple brightness, wavelength, and forward voltage bins, allowing designers to select the optimal combination for their specific requirements.

2. Technical Parameter Analysis

2.1 Electrical and Optical Characteristics (at T_s=25°C)

The following parameters are measured under a forward current of 20mA unless otherwise noted:

• Spectral Half Bandwidth (Δλ): Typically 15nm. This narrow spectral width indicates a relatively pure color output.
• Forward Voltage (V_F): Binned into three groups: B0 (1.8–2.0V), C0 (2.0–2.2V), and D0 (2.2–2.4V). The low forward voltage enables efficient operation in low-voltage circuits.
• Dominant Wavelength (λ_D): Spans from 562.5nm to 575nm, covering multiple bins (A20, B10, B20, C10, C20). This yellow-green region is commonly used for status indicators and cautionary signals.
• Luminous Intensity (I_V): Ranges from 12mcd (B00 bin) up to 100mcd (F20 bin), providing flexibility for different brightness requirements.
• Viewing Angle (2θ_1/2): Typically 140°, ensuring wide distribution of light.
• Reverse Current (I_R): Maximum 10µA at V_R=5V, indicating good reverse blocking capability.
• Thermal Resistance (R_THJ-S): 450°C/W (junction to solder point). This relatively high value requires careful thermal management in high-current or high-density applications.

2.2 Absolute Maximum Ratings

The device must not be operated beyond the following limits to avoid permanent damage:

• Power Dissipation (P_d): 72 mW
• Forward Current (I_F): 30 mA (DC), 60 mA (pulse, 1/10 duty, 0.1ms pulse width)
• ESD (HBM): 2000 V
• Operating Temperature (T_opr): –40 to +85°C
• Storage Temperature (T_stg): –40 to +85°C
• Junction Temperature (T_j): 95°C

Note: The maximum forward current should be derated based on actual package temperature to ensure junction temperature does not exceed the rated limit.

2.3 Thermal Characteristics

The thermal resistance of 450°C/W indicates a significant temperature rise per unit of dissipated power. For example, at 20mA with typical V_F=2.0V (40mW dissipation), the junction-to-solder point temperature rise is approximately 18°C. In ambient temperatures above 65°C, derating is necessary to keep the junction below 95°C. The thermal management should consider PCB copper area, via patterns, and airflow.

3. Binning System

3.1 Wavelength Bins

The dominant wavelength is categorized into five bins: A20 (562.5–565nm), B10 (565–567.5nm), B20 (567.5–570nm), C10 (570–572.5nm), and C20 (572.5–575nm). This fine binning allows system designers to achieve consistent color matching across multiple LEDs in an array, critical for backlighting or signage.

3.2 Luminous Intensity Bins

Intensity is sorted into six bins: B00 (12–18mcd), C00 (18–28mcd), D00 (28–43mcd), E00 (43–65mcd), F10 (65–80mcd), and F20 (80–100mcd). Each bin represents a range factor approximately 1.5×, enabling tight control of brightness uniformity.

3.3 Forward Voltage Bins

Forward voltage is divided into three bins: B0 (1.8–2.0V), C0 (2.0–2.2V), and D0 (2.2–2.4V). This helps in designing current-limiting resistors and ensuring consistent power dissipation in parallel configurations.

4. Performance Curve Analysis

4.1 Forward Voltage vs. Forward Current (I-V Curve)

The typical I-V curve shows a sharp knee around 1.8V, with current rising exponentially after 2.0V. At 20mA, V_F is approximately 2.0V (typical). The curve indicates the device behaves as a conventional p-n junction diode.

4.2 Relative Intensity vs. Forward Current

The relative intensity increases nearly linearly with current up to 30mA. At 10mA, intensity is about 50% of the value at 20mA; at 30mA it reaches approximately 150%. This linearity simplifies dimming via current control.

4.3 Temperature Characteristics

As the pin temperature rises from 25°C to 100°C, the relative intensity decreases by about 10–15%. The forward current derating curve shows that at pin temperatures above 60°C, the maximum allowable DC current must be reduced to avoid exceeding the junction temperature limit.

4.4 Dominant Wavelength vs. Forward Current

The dominant wavelength shifts slightly (about 1–2nm) when the current increases from 5mA to 30mA. This shift is within the binning tolerance and generally negligible for most applications.

4.5 Spectral Distribution

The relative spectral power distribution peaks near 570nm with a full width at half maximum (FWHM) of ~15nm. The spectrum shows minimal secondary peaks, confirming high color purity.

4.6 Radiation Pattern

The radiation pattern is Lambertian-like with a half-angle of ~70°, providing uniform intensity over a wide angle. The diagram indicates relative intensity drops to 50% at about ±70° off-axis.

5. Mechanical and Package Information

5.1 Package Dimensions

The LED is housed in a 3.2mm × 1.6mm × 0.7mm package with solder pads on the bottom. The top view shows a rectangular emitting area; the bottom view reveals two anode/cathode pads (pad 1 and pad 2). Polarity is indicated by a small mark on the package. The recommended soldering land pattern includes a 1.6mm × 1.5mm pad for the anode and a 2.1mm × 1.6mm pad for the cathode, with a total footprint of 4.4mm × 1.6mm.

5.2 Solder Pad Design

For reliable solder joints, the PCB layout should match the recommended pattern: a gap of 0.30mm between pads and generous copper areas for thermal conduction. The package is designed for reflow soldering; hand soldering is allowed with iron temperature below 300°C and duration under 3 seconds.

6. Soldering and Assembly Guidelines

6.1 Reflow Soldering Profile

The recommended Pb-free reflow profile specifies a ramp-up rate ≤3°C/s to a preheat zone (150–200°C for 60–120s), followed by a ramp to 217°C (time above 217°C: 60–150s), and a peak temperature of 260°C for up to 10s. Cooling rate should be ≤6°C/s. Total time from 25°C to peak should not exceed 8 minutes. Do not perform more than two reflow cycles; if the interval between cycles exceeds 24 hours, the LEDs must be baked to remove moisture.

6.2 Hand Soldering and Rework

If hand soldering is unavoidable, use a soldering iron set below 300°C and complete the joint within 3 seconds. Only one hand soldering operation is allowed. For rework, a double-head iron is recommended to heat both terminals simultaneously. Do not apply mechanical force to the LED body during or after soldering.

6.3 Storage and Handling

Unopened bags can be stored at ≤30°C and ≤75% RH for up to one year. After opening, the LEDs must be used within 168 hours at ≤30°C and ≤60% RH. If the desiccant has faded or the storage time exceeded, bake at 60±5°C for >24 hours before use. Always use tweezers on the side of the package; avoid touching the silicone lens directly.

7. Packaging and Ordering Information

7.1 Carrier Tape and Reel

LEDs are supplied in 8mm wide carrier tape with a pitch of 4mm. Each reel contains 4000 pieces. The tape includes a cover tape and polarity mark. Reel dimensions: outer diameter 178±1mm, hub diameter 60±1mm, and width 8.0±0.1mm.

7.2 Label and Moisture Barrier Bag

Each reel is labeled with part number, spec number, lot number, bin code (flux, chromaticity, voltage, wavelength), quantity, and date. The reel is sealed in a moisture barrier bag together with a desiccant and a humidity indicator card (not shown). An ESD warning label is also attached.

7.3 Shipping Carton

Reels are packed in cardboard boxes for shipment. The outer box is marked with the manufacturer’s name (omitted here for privacy) and product information.

8. Reliability Test Items and Conditions

The LED has passed the following reliability tests with zero failures (Ac/Re 0/1):

• Reflow (260°C max, 10s, 2 cycles)
• Temperature Cycle (–40°C to 100°C, 30min dwell, 100 cycles)
• Thermal Shock (–40°C to 100°C, 15min dwell, 300 cycles)
• High Temperature Storage (100°C, 1000h)
• Low Temperature Storage (–40°C, 1000h)
• Life Test (T_a=25°C, I_F=20mA, 1000h)

Failure criteria: V_F > 1.1× upper spec limit, I_R > 2.0× upper spec limit, or luminous flux < 0.7× lower spec limit.

9. Application Recommendations

This yellow-green LED is ideal for optical indicators, switch and symbol backlighting, and general-purpose status displays. Due to its wide viewing angle, it is particularly suitable for dashboard lights, pushbutton illumination, and small signage. Designers should incorporate current-limiting resistors to prevent overcurrent. In applications with high ambient temperatures or dense LED arrays, thermal analysis is essential to keep junction temperature below 95°C.

10. Technical Comparison

Compared to traditional through-hole yellow-green LEDs, this SMD version offers lower profile, compatibility with automated assembly, and better uniformity in viewing angle. The narrow spectral width (15nm) provides more saturated color than some broader-spectrum alternatives. The multiple binning options allow tighter color and brightness matching, which is critical for high-end displays. However, the thermal resistance of 450°C/W is relatively high; newer designs with improved thermal management can offer lower values (e.g., 200–300°C/W), so careful PCB layout is advised.

11. Frequently Asked Questions

Q1: Can I drive this LED at 30mA continuously?
Yes, but only if the package temperature is kept low enough so that junction temperature stays below 95°C. In typical 25°C ambient, 30mA is safe. At higher ambient, derate accordingly.

Q2: What is the recommended storage condition after opening the bag?
Store at ≤30°C and ≤60% RH. Use within 168 hours. If exceeded, bake at 60°C for >24 hours.

Q3: How can I prevent ESD damage?
Use grounded workstations, conductive tools, and antistatic packaging. The LED has an ESD rating of 2000V (HBM), but precautions are still recommended.

Q4: Can I use this LED in outdoor applications?
The operating temperature range is –40 to +85°C, which covers most outdoor environments. However, the LED is not specified for direct exposure to UV or high humidity without additional conformal coating.

12. Practical Use Cases

In a typical design, six of these yellow-green LEDs are placed around a push-button switch to provide 360° indication. The wide 140° viewing angle ensures visibility from any direction. A current-limiting resistor of 100Ω (for a 5V supply) sets the current to approximately 30mA per LED, giving bright illumination. The small footprint allows mounting on a compact PCB inside the switch housing. Another use case is in a battery charger indicator: three LEDs—red, yellow-green, and blue—indicate charging status. The yellow-green LED lights up when charging is complete, with intensity binned to match the red and blue visually.

13. Working Principle

This LED is a p-n junction diode made from gallium phosphide (GaP) or related materials that emit photons when electrons recombine with holes in the active region. The bandgap energy corresponds to a wavelength in the yellow-green spectrum (around 570 nm). The chip is encapsulated in a clear silicone lens that shapes the light output into a wide beam. The package includes two terminals (anode and cathode) for connection to a driving circuit.

14. Development Trends

As LED technology evolves, we see trends toward even smaller packages (e.g., 2.0×1.2mm), higher luminous efficacy (over 150 lm/W for green), and lower thermal resistance through advanced substrate materials. The binning resolution is becoming finer, allowing 0.5nm wavelength bins. Furthermore, integration with intelligent driver ICs and digital interfaces is common in smart lighting. The yellow-green color remains important for safety and indication, and its use in automotive and industrial applications is expected to grow.