White LED RF-A3E31-W60H-B3 Datasheet - 3.0x3.0x0.55mm - 2.8-3.4V - 1.428W Max - Automotive Grade

1. Product Overview

The RF-A3E31-W60H-B3 is a high-performance white LED designed for demanding automotive interior and exterior lighting applications. It utilizes a blue LED chip combined with precisely formulated phosphor to achieve a natural white light output. The package measures 3.00mm x 3.00mm x 0.55mm, making it suitable for space-constrained lighting modules. With a typical forward voltage of 2.8-3.4V at 350mA and a maximum power dissipation of 1.428W, this LED delivers excellent luminous flux of 105-160 lumens while maintaining high efficiency. The device is qualified according to AEC-Q102 stress test guidelines for automotive grade discrete semiconductors, ensuring reliability under harsh operating conditions.

1.1 Key Features

• EMC (Epoxy Molding Compound) package for robust mechanical strength and thermal performance
• Extremely wide viewing angle of 120° (half intensity angle)
• Suitable for all SMT assembly and reflow soldering processes
• Available on tape and reel packaging (4000 pcs/reel)
• Moisture sensitivity level: Level 2 (per JEDEC)
• RoHS compliant
• ESD withstand capability: 8000V (HBM)
• Operating temperature range: -40°C to +125°C
• Storage temperature range: -40°C to +125°C
• Junction temperature maximum: 150°C

1.2 Target Applications

This LED is specifically designed for automotive lighting systems, including both interior and exterior applications such as:

• Daytime running lights (DRL)
• Turn signal indicators
• Brake lights
• Interior ambient lighting
• License plate illumination
• Position lights
• Side marker lights

The wide operating temperature range and AEC-Q102 qualification ensure stable performance in severe automotive environments.

2. Technical Parameter Analysis

2.1 Electrical and Optical Characteristics (at Ts=25°C, IF=350mA)

The forward voltage range of 2.8-3.4V at 350mA is typical for power white LEDs using InGaN blue chips. The tight voltage binning (0.2V steps) ensures easy paralleling of multiple LEDs. Luminous flux from 105 to 160 lumens represents a high efficiency class, with typical efficacy exceeding 100 lm/W under rated current. The wide 120° viewing angle provides excellent light distribution for automotive signal and illumination tasks.

2.2 Absolute Maximum Ratings

The absolute maximum ratings define the safe operating limits. The maximum forward current of 420mA and peak current of 700mA allow for pulsed operation in applications like turn signals. The high ESD rating of 8kV HBM ensures robustness during handling and assembly. Thermal management is critical: the junction temperature must not exceed 150°C to prevent degradation.

2.3 Thermal Resistance Interpretation

Two thermal resistance values are provided: Rth JS real (14°C/W typical, 21°C/W max) and Rth JS electrical (9°C/W typical, 13°C/W max). The electrical method uses a temperature-sensitive parameter (forward voltage) to estimate junction temperature, while the real method uses physical temperature measurement. These values indicate that for every watt of power dissipated, the junction temperature rises by 9-21°C above the solder point temperature. At 350mA and typical VF=3.1V, power dissipation is about 1.085W, resulting in a junction-to-solder temperature rise of ~15°C (using real Rth). Designers must ensure adequate heat sinking to keep junction temperature below 150°C, especially when operating at high ambient temperature (125°C).

3. Binning System

3.1 Forward Voltage Bins (IF=350mA)

3.2 Luminous Flux Bins (IF=350mA)

3.3 Chromaticity Bins (CIE 1931)

The color coordinates are binned into seven VM groups (VM1 to VM7) based on the CIE 1931 chromaticity diagram. Each bin is defined by four quadrilateral corner points (x,y). For example, VM1: (0.3150,0.2995), (0.3115,0.3212), (0.3268,0.3371), (0.3282,0.3162). These bins correspond to cool white color temperatures around 5000-6000K, suitable for automotive white light specifications. The binning ensures color consistency across production volumes.

4. Performance Curves Analysis

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

Figure 1-7 shows a typical exponential I-V characteristic. At 2.8V the current is minimal, while at 3.4V it reaches about 420mA. The curve demonstrates that small voltage variations cause large current changes, emphasizing the need for current regulation (driver IC or resistor) to avoid thermal runaway.

4.2 Relative Luminous Flux vs. Forward Current

Figure 1-8 illustrates that luminous flux increases nearly linearly with current up to 350mA, then gradually saturates. At 350mA the relative flux is ~100%, while at 100mA it's about 35%. This linear relationship simplifies dimming using PWM or analog current control.

4.3 Junction Temperature vs. Relative Luminous Flux

Figure 1-9 shows a negative temperature coefficient: relative flux drops to ~85% at 125°C junction (from 100% at 25°C). This ~15% loss must be accounted for in thermal design. At high ambient temperatures, derating the current may be necessary.

4.4 Solder Temperature vs. Forward Current Derating

Figure 1-10 provides the maximum allowed forward current as a function of solder point temperature. At 25°C, 420mA is allowed; at 125°C, only about 250mA is permitted to keep junction temperature below 150°C. This derating curve is essential for safe operation.

4.5 Voltage Shift vs. Junction Temperature

Figure 1-11 shows forward voltage decreases with temperature at a rate of about -2mV/°C. At 150°C, VF drops ~0.25V from 25°C value. This negative temperature coefficient helps balance current in parallel arrays but requires compensation in precision circuits.

4.6 Radiation Pattern

Figure 1-12 illustrates a Lambertian-like emission pattern with half intensity at ±60°, confirming the 120° viewing angle. This wide distribution is ideal for automotive signal lights requiring broad visibility.

4.7 Chromaticity Shift vs. Temperature and Current

Figures 1-13 and 1-14 show small shifts in CIE coordinates (ΔCx, ΔCy) with temperature and current. Over the -40°C to 150°C range, ΔCx shifts about -0.02 and ΔCy about +0.01. With current from 0 to 400mA, shifts are within ±0.01. These shifts are small enough to maintain acceptable color consistency.

4.8 Spectrum Distribution

Figure 1-15 shows a typical white LED spectrum with a blue peak at ~450nm and a broad phosphor emission from 500-700nm. The blue peak intensity is roughly 0.4 relative to the phosphor peak. This spectrum yields a high color rendering index suitable for automotive interior lighting where color discrimination is important.

5. Mechanical and Package Information

5.1 Package Dimensions

The LED package measures 3.00mm (length) x 3.00mm (width) x 0.55mm (height). Tolerances are ±0.2mm unless otherwise noted. The bottom view shows two anode pads (2.60mm x 0.65mm and 0.50mm x 0.65mm) and two cathode pads (1.55mm x 0.65mm and 0.30mm x 0.65mm). A thermal pad (2.30mm x 2.40mm) is provided for heat dissipation. Polarity marking is indicated by a corner notch.

5.2 Recommended Soldering Pattern

Figure 1-5 shows a recommended PCB footprint: two large rectangular pads for anode/cathode (0.65mm width) and a large central thermal pad (2.30mm x 2.40mm). Proper solder stencil design ensures adequate solder volume for thermal and electrical connection.

6. Soldering and Assembly Guidelines

6.1 Reflow Profile

The LED is compatible with lead-free reflow soldering. Key parameters: ramp-up rate ≤3°C/s (Tsmax to TP), preheat from 150°C to 200°C for 60-120s, time above 217°C (TL) max 60s, peak temperature 260°C with time within 5°C of peak ≤30s (tp ≤10s). Cooling rate ≤6°C/s. Total time from 25°C to peak ≤8 minutes.

6.2 Precautions

• Do not exceed two reflow cycles. If time between cycles exceeds 24 hours, LEDs may absorb moisture and require baking.
• Avoid applying mechanical stress on the silicone surface during heating.
• Do not use warped PCBs; after soldering, avoid bending the board.
• No rapid cooling after reflow.
• For repair, use a double-head soldering iron; confirm no damage to LED.
• The silicone encapsulation is soft; use appropriate pick-and-place nozzle force.

6.3 Storage Conditions

7. Packaging and Ordering Information

7.1 Package Quantity

Standard packaging: 4,000 pieces per reel.

7.2 Carrier Tape Dimensions

Embossed carrier tape: width 8.00±0.1mm, pocket pitch 4.00±0.1mm, thickness 0.20±0.05mm. Pocket dimensions: A0=3.30±0.1mm, B0=3.50±0.1mm, K0=0.90±0.1mm. Cover tape width 5.30±0.1mm. Reel dimensions: 180±1mm (flange diameter), 60±1mm (hub diameter), 13.0±0.5mm (hub hole).

7.3 Label Information

The label includes: Part Number (PART NO.), Spec Number (SPEC NO.), Lot Number (LOT NO.), Bin Code (BIN CODE), Luminous Flux (Φ), Chromaticity Bin (XY), Forward Voltage (VF), Wavelength Code (WLD), Quantity (QTY), and Date (DATE).

8. Application Design Recommendations

8.1 Thermal Management

Given the maximum power of 1.428W and thermal resistance of 14°C/W, proper heat sinking is mandatory. Use a large copper area on the PCB connected to the thermal pad. For automotive applications, consider metal-core PCBs (MCPCB) to spread heat to the housing. The junction temperature must be kept below 150°C under worst-case ambient (125°C).

8.2 Electrical Design

Always use current limiting resistors or constant-current drivers. The steep I-V curve means a 0.1V increase can raise current by 15-20%, risking overstress. Place a resistor in series with each LED or use a dedicated LED driver with thermal foldback. For pulsed operation (e.g., turn signals), ensure peak current does not exceed 700mA and duty cycle ≤10%.

8.3 Optical Design

The 120° viewing angle allows broad coverage. For collimated beams (e.g., forward lighting), secondary optics like reflectors or TIR lenses are needed. The compact 3x3mm package is compatible with standard optics designed for 3030 or 3535 LEDs.

8.4 Environmental Considerations

For automotive use, the LED must withstand vibration, humidity, and temperature cycles. The AEC-Q102 qualification ensures reliability, but system-level testing (e.g., thermal shock, salt spray) is recommended. Avoid exposure to sulfur-containing compounds (>100ppm) and halogens (Br+Cl <1500ppm) to prevent corrosion of silver-plated leads and phosphor degradation.

9. Technology Comparison: EMC Package vs. Traditional PLCC

EMC (Epoxy Molding Compound) packages offer several advantages over conventional PLCC (Plastic Leaded Chip Carrier) packages:

• Higher reliability: EMC has better adhesion to leadframes, reducing delamination risk.
• Better thermal resistance: Lower thermal impedance due to thinner molding.
• Higher temperature capability: Can withstand 260°C peak reflow without cracking.
• Improved optical performance: Less light absorption in the molding material.
• Suitable for automotive: Better passaivation against moisture and contaminants.

However, EMC packages are generally more expensive than PLCC. The RF-A3E31 uses EMC, making it ideal for automotive applications where long-term reliability is critical.

10. Frequently Asked Questions (FAQ)

Q1: Can I drive this LED at 350mA continuously without heatsink?

At 350mA, power dissipation is ~1.1W. Without heatsink, the junction temperature could exceed 150°C in room ambient, causing rapid degradation. A heatsink or MCPCB is required for continuous operation.

Q2: What is the typical color temperature?

The chromaticity bins (VM1-VM7) correspond to cool white approximately 5000-6500K. Exact CCT depends on bin.

Q3: Is this LED compatible with 5V logic?

The forward voltage is 2.8-3.4V. A current-limiting resistor is needed when driving from 5V. For example, with VF=3V and IF=350mA, R = (5-3)/0.35 = 5.7Ω (use 5.6Ω standard). Ensure resistor power rating (0.7W).

Q4: How many LEDs can be placed in series?

In automotive systems with 12V supply, typically 3-4 LEDs in series (12V - driver dropout). With VF=3.2V, 3 in series gives ~9.6V leaving headroom for driver.

Q5: Does the LED require ESD protection?

Although rated for 8kV HBM, additional ESD protection on the board (e.g., TVS diode) is recommended for automotive applications to ensure robustness against transient voltages.

11. Application Case Study: Daytime Running Light (DRL)

A typical DRL module uses multiple white LEDs powered by a constant-current driver. The RF-A3E31-W60H-B3, with its wide viewing angle and high flux, can be used in a linear array of 6-8 LEDs. Each LED runs at 350mA, producing total ~800-1200 lumens. The LEDs are mounted on an MCPCB with thermal interface to the aluminum housing. A simple buck or linear driver (e.g., TPS92518) regulates current. The wide viewing angle ensures compliance with ECE R87 regulations for DRL photometric distribution. The AEC-Q102 qualification gives confidence in -40°C to 85°C ambient range.

12. Working Principle

The white LED operates on the principle of phosphor-conversion. A blue InGaN/GaN LED chip emits blue light at approximately 450 nm. This blue light passes through a yellow-emitting phosphor (typically YAG:Ce) which absorbs part of the blue light and re-emits in a broad yellow-green spectrum (500-700 nm). The combination of transmitted blue and phosphor-converted yellow light produces white light. The exact spectral distribution determines the correlated color temperature (CCT) and color rendering index (CRI). The phosphor is mixed with silicone and dispensed over the chip during manufacturing. Temperature changes affect both the LED chip efficiency and phosphor quantum efficiency, leading to minor color shifts as shown in the performance curves.

13. Development Trends in Automotive LED Lighting

The automotive LED market is moving toward higher efficacy, smaller packages, and increased integration. Key trends:

• Micro-LED arrays for adaptive driving beam (ADB) headlights with pixel-level control.
• High-luminance LEDs exceeding 200 lm/mm² for laser-like brightness.
• Smart LED modules with integrated drivers and communication (LIN, CAN).
• Reduced thermal resistance using new substrate materials (e.g., AlN, SiC).
• Improved reliability through advanced encapsulation (silicone, hybrid).
• Human-centric lighting with tunable CCT for interior comfort.

The RF-A3E31, with its EMC package and AEC-Q102 certification, is well-positioned for the current generation of automotive exterior lighting. Future developments may require even smaller footprints (e.g., 2016, 1616) and higher luminous fluxes for matrix headlights.