White LED RF-A3E31-WYSH-B2 Datasheet - Size 3.0x3.0x0.55mm - Voltage 3.1V - Power 1.1W - English Technical Document

2. Product Overview

2.1 General Description

The RF-A3E31-WYSH-B2 is a high-performance white LED fabricated by combining a blue LED chip with phosphor conversion. It is packaged in a compact 3.0mm × 3.0mm × 0.55mm surface-mount EMC (Epoxy Molding Compound) package, offering excellent thermal resistance and reliability. This LED is designed for demanding automotive lighting applications, both interior and exterior, and meets the rigorous AEC-Q102 stress test qualification guidelines for automotive-grade discrete semiconductors.

2.2 Key Features

• EMC Package: The use of EMC material provides superior heat dissipation and mechanical strength compared to traditional plastic packages.
• Extremely Wide Viewing Angle: With a 120° half-intensity angle, it ensures uniform light distribution for various lighting designs.
• SMT Compatibility: Suitable for all standard SMT assembly and reflow soldering processes.
• Tape & Reel Packaging: Available on 8mm carrier tape and 180mm reel, 5000pcs per reel, for efficient automated placement.
• Moisture Sensitivity Level: MSL Level 2, requiring minimal handling precautions for moisture-sensitive devices.
• Environmental Compliance: RoHS and REACH compliant, free from hazardous substances.
• AEC-Q102 Qualification: The product qualification test plan is based on the guidelines of AEC-Q102, ensuring reliability for automotive environments.

2.3 Applications

• Automotive Lighting: Interior lighting (dashboard, dome lights) and exterior lighting (tail lights, turn signals, daytime running lights).
• General Illumination: Suitable for any application requiring high brightness and wide viewing angle in a compact footprint.

3. In-Depth Technical Parameter Analysis

3.1 Electrical and Optical Characteristics

Tested at a solder temperature of 25°C and a forward current of 350mA, the LED exhibits the following nominal characteristics:

• Forward Voltage (VF): Minimum 2.8V, typical 3.1V, maximum 3.4V. This narrow distribution allows for consistent design in series-parallel arrays.
• Luminous Flux (Φ): Minimum 83.7 lm, typical 102 lm, maximum 117 lm. This range corresponds to high efficacy for a 0.35A drive current, making it suitable for both signal and ambient lighting.
• Viewing Angle (2θ1/2): 120° (full width at half maximum), enabling wide-area illumination.
• Thermal Resistance (RTHJ-S): 12°C/W, indicating efficient heat transfer from junction to solder point, crucial for thermal management in high-current operation.
• Reverse Current (IR): Not designed for reverse operation; reverse voltage should not be applied.

3.2 Absolute Maximum Ratings

The LED's safe operating limits are clearly defined:

• Power Dissipation (PD): 1700 mW maximum.
• Forward Current (IF): 500 mA continuous; 700 mA pulsed (1/10 duty cycle, 10ms pulse width).
• Reverse Voltage (VR): Not designed for reverse operation.
• ESD (HBM): Withstands 8000V, with a yield over 90%.
• Operating Temperature (TOPR): -40°C to +125°C.
• Storage Temperature: -40°C to +125°C.
• Junction Temperature (TJ): 150°C maximum.

Note: All measurements are made under standardized conditions. The maximum current should be determined after measuring the package temperature to ensure the junction temperature does not exceed the rated limit.

3.3 Thermal Characteristics

With a thermal resistance of 12°C/W from junction to solder point, the LED offers good thermal performance. For example, at 350mA with a typical VF of 3.1V, the power is approximately 1.085W, resulting in a junction-to-solder temperature rise of about 13°C. Proper heat sinking is essential to maintain junction temperature below 150°C, especially at higher currents or elevated ambient temperatures.

4. Binning System Explanation

4.1 Forward Voltage Bins

The LED is sorted into six voltage bins at 350mA: G1 (2.8-2.9V), G2 (2.9-3.0V), H1 (3.0-3.1V), H2 (3.1-3.2V), I1 (3.2-3.3V), I2 (3.3-3.4V). This tight binning ensures consistent brightness and power consumption in mass production.

4.2 Luminous Flux Bins

Three luminous flux bins are defined: RA (83.7-93.2 lm), RB (93.2-105 lm), SA (105-117 lm). Selection of appropriate flux bins allows customers to meet specific brightness requirements while maintaining color uniformity.

4.3 Chromaticity Bins

The LED is offered in chromaticity bin 5E, defined by four CIE coordinates: (0.5536,0.4221), (0.5764,0.4075), (0.5883,0.4111), (0.5705,0.4289). This corresponds to a warm white color region (amber-white), typically used in automotive signal lighting such as turn signals and rear combinations.

5. Performance Curve Analysis

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

The I-V curve shows that at 100mA the forward voltage is approximately 2.7V, at 350mA it is about 3.1V, and at 500mA it approaches 3.4V. The curve is typical for GaN-based blue LEDs, with a dynamic resistance that increases slightly at higher currents.

5.2 Forward Current vs. Relative Intensity

Relative luminous intensity increases almost linearly with forward current up to about 300mA, then begins to saturate due to heating and efficiency droop. At 500mA, the relative intensity is approximately 160% of the intensity at 350mA, indicating good current handling capability.

5.3 Temperature Dependence

The LED's performance varies with solder point temperature (TS):

• Relative Intensity vs. TS: At TS=125°C, the relative intensity drops to about 65% of the value at 25°C, highlighting thermal sensitivity.
• Forward Current Derating: To maintain junction temperature ≤150°C, the maximum forward current is derated from 500mA at TS=25°C to about 200mA at TS=125°C.
• Forward Voltage vs. TS: VF decreases with increasing temperature (negative coefficient of approximately -2mV/°C), typical for LEDs.

5.4 Radiation Pattern

The radiation diagram shows a Lambertian-like distribution with a half-angle of 60° (120° FWHM). The intensity is maximum at 0° and drops to 50% at ±60°, providing uniform illumination across a wide area.

5.5 Chromaticity Coordinate Shift vs. Forward Current

As forward current increases from 0 to 500mA, the CIE x coordinate shifts by approximately +0.012 and the y coordinate by +0.006. This shift is due to the change in spectral power distribution at different current densities. Designers should account for this color shift in applications requiring tight color tolerance.

5.6 Spectrum Distribution

The spectrum is a typical white LED spectrum: a blue peak around 450nm and a broad yellow phosphor emission centered around 560nm. The relative intensity of the blue peak is about 0.2 compared to the phosphor peak, indicating a warm white appearance. The spectrum covers from 430nm to 750nm.

6. Mechanical and Packaging Information

6.1 Package Dimensions

The LED package measures 3.00mm × 3.00mm × 0.55mm (length × width × height). The bottom view shows two cathode pads and two anode pads: the larger pad (2.60mm × 1.50mm) is the anode, and the smaller pad (2.40mm × 0.65mm) is the cathode. Detailed dimensions are provided in the datasheet drawings. All dimensions have a tolerance of ±0.2mm unless otherwise noted.

6.2 Recommended Soldering Patterns

The recommended PCB land pattern includes two rectangular pads: one for anode (1.55mm × 0.65mm) and one for cathode (0.65mm × 0.55mm), with appropriate spacing to match the package bottom. Proper pad design ensures good solder joint formation and thermal transfer.

6.3 Polarity Identification

Polarity is clearly marked on the package: a notch or dot on the top view indicates the cathode side. The bottom view also shows that the larger pad corresponds to the anode. Incorrect polarity can lead to LED damage as reverse operation is not allowed.

7. Soldering and Assembly Guidelines

7.1 Reflow Soldering Parameters

The LED is compatible with lead-free reflow soldering. The recommended reflow profile includes:

• Average ramp-up rate: Max 3°C/s (from Tsmin to Tp).
• Preheat: 150°C to 200°C for 60-120 seconds.
• Time above 217°C: 60-120 seconds.
• Peak temperature: 260°C, with a time within 5°C of peak of max 10 seconds.
• Cooling rate: Max 6°C/s.
• Time from 25°C to peak: Max 8 minutes.

Reflow soldering should not exceed two times. If more than 24 hours elapse between soldering operations, the LEDs may be damaged by absorbed moisture. Manual soldering is possible with an iron at ≤300°C for ≤3 seconds, but only once.

7.2 Handling Precautions

• Mechanical Stress: Do not apply pressure on the silicone lens surface, as it is soft and may damage internal circuitry. Use proper tools to handle from the side.
• Warpage: Do not mount components on warped PCBs; avoid bending the circuit after soldering.
• Cooling: Allow gradual cooling after reflow; rapid cooling or vibration during cooling may cause damage.
• Cleaning: Isopropyl alcohol is recommended for cleaning. Ultrasonic cleaning is not recommended as it may damage the LED.
• Moisture Storage: Unopened bags: ≤30°C, ≤75% RH for up to 1 year. After opening: ≤30°C, ≤60% RH, use within 24 hours. If exceeded, bake at 60±5°C for ≥24 hours.
• ESD Protection: The LED is sensitive to electrostatic discharge; proper ESD precautions should be taken during handling.

8. Packaging and Ordering Information

8.1 Packaging Specifications

The LED is supplied in tape and reel packaging: 5000pcs per reel. The carrier tape has dimensions: A0=3.30±0.1mm, B0=3.30±0.1mm, K0=0.90±0.1mm, with standard 8mm tape width. The reel diameter is 180mm, hub diameter 60mm, and arbor hole 13mm. Reels are placed in moisture barrier bags with desiccant and humidity indicator.

8.2 Label Information

Each reel carries a label containing: Part Number (model), Spec Number, Lot Number, Bin Code (flux, chromaticity, voltage), Quantity, and Date. This facilitates traceability and inventory management.

9. Application Recommendations

9.1 Typical Application Scenarios

Due to its high brightness, wide viewing angle, and AEC-Q102 qualification, the RF-A3E31-WYSH-B2 is ideal for:

• Automotive Exterior Lighting: Tail lights, turn signals, brake lights, daytime running lights (DRL).
• Automotive Interior Lighting: Dome lights, map lights, ambient lighting strips.
• Industrial & Commercial Lighting: Signage, decorative lighting, emergency lighting.

9.2 Design Considerations

• Thermal Management: Ensure adequate heat sinking to keep the solder point temperature below 125°C for optimal lifetime. Use thermal vias and copper planes under the LED pads.
• Current Regulation: Use constant-current drivers or series resistors to limit the current and prevent thermal runaway due to VF variation. Avoid reverse voltage.
• Sulfur and Halogen Control: The operating environment should contain less than 100ppm of sulfur compounds. Single bromine and chlorine content in surrounding materials should be below 900ppm each, with total below 1500ppm, to prevent corrosion and discoloration of the silicone lens.
• Volatile Organic Compounds (VOCs): Avoid adhesives and potting materials that outgas organic vapors, as they can penetrate the silicone and cause yellowing and lumen depreciation.

10. Frequently Asked Questions (FAQ)

Q: Can I drive this LED at 500mA continuously?
A: The absolute maximum continuous forward current is 500mA, but only when the solder point temperature is low enough to keep the junction temperature ≤150°C. In practice, at high ambient temperatures, derating is necessary. Refer to the derating curve (Fig. 1-10) for guidance.

Q: What is the typical color temperature of this LED?
A: Based on the chromaticity bin 5E (CIE coordinates around 0.57,0.41), the correlated color temperature is approximately 2700-3000K, which is warm white/amber. This is typical for automotive signal lighting.

Q: How does the LED behave under reverse bias?
A: This LED is not designed for reverse operation. Applying reverse voltage may cause permanent damage. Always ensure the circuit design prevents reverse voltage.

Q: What is the recommended storage condition after opening the moisture barrier bag?
A: The LED should be stored at ≤30°C and ≤60% RH, and used within 24 hours. If not used, bake at 60±5°C for ≥24 hours before reflow.

Q: Can I use ultrasonic cleaning after soldering?
A: Ultrasonic cleaning is not recommended as it may cause mechanical damage to the LED, especially to the bond wires and silicone lens. Use isopropyl alcohol and gentle cleaning methods.

11. Practical Application Examples

11.1 Automotive Turn Signal Module

In a typical turn signal module, 6-8 LEDs of this type are connected in series with a current-limiting resistor and driven by a 12V automotive electrical system. Assuming 3.1V typical VF and 350mA, six LEDs in series require 18.6V, plus resistor drop. A buck-boost constant-current driver is recommended for efficiency. The wide 120° beam angle ensures visibility from all angles.

11.2 Interior Ambient Lighting Strip

For ambient lighting, the LEDs can be placed on a flexible PCB with a spacing of 10-15mm. Driven at 100-200mA, they produce soft warm white light. Silicone diffusers can be used to eliminate hot spots. Due to MSL Level 2, the assembly needs to be done within 24 hours of opening the bag, and the PCB must be kept free of contaminants.

12. Principle of Operation

This white LED operates on the principle of phosphor-converted LED (pc-LED). A blue InGaN/GaN LED chip emits blue light at approximately 450nm. This blue light excites a yellow-emitting phosphor (typically YAG:Ce or similar) coated on the chip. The combination of blue and yellow light produces white light. The exact color point (chromaticity) is determined by the thickness and composition of the phosphor layer. The device is driven by a constant current; the current directly controls the brightness and also slightly affects the color temperature due to the different thermal behavior of the phosphor and the chip.

13. Industry Trends and Development Direction

The automotive lighting industry is rapidly transitioning from traditional halogen and xenon bulbs to LED-based solutions. Key trends include:

• Higher Efficacy: Continuous improvements in phosphor efficiency and chip technology push efficacy above 150 lm/W for white LEDs.
• Miniaturization: Smaller packages like 3.0x3.0mm enable thinner and more flexible lighting designs.
• Color Tuning: Multi-color and tunable white LEDs are gaining popularity for adaptive headlights and ambient mood lighting.
• Reliability: Standards like AEC-Q102 ensure automotive-grade reliability, with rigorous testing for thermal cycling, humidity, and vibration.
• Smart Lighting: Integration with sensors and communication modules (Li-Fi, V2X) is the next frontier.

The RF-A3E31-WYSH-B2 LED, with its AEC-Q102 qualification and high performance, is well-positioned to meet these evolving demands in the automotive sector.