LED Red 2.7x2.0x0.6mm - Forward Voltage 2.0-2.6V - Power 1.1W - Dominant Wavelength 612.5-625nm - English Technical Datasheet

1. Product Overview

The RF-A4E27-R15H-S1 is a high-performance red LED based on AlGaInP (Aluminum Gallium Indium Phosphide) semiconductor technology. It is housed in a compact EMC (Epoxy Molding Compound) package with dimensions of 2.7 mm × 2.0 mm × 0.6 mm. The device delivers a dominant wavelength range of 612.5 nm to 625 nm, making it suitable for red signaling and interior/exterior automotive lighting applications. With an extremely wide viewing angle of 120° and a moisture sensitivity level of 2, the LED is designed for reliable surface-mount assembly and reflow soldering processes. It fully complies with RoHS requirements and its qualification test plan follows the AEC-Q102 standard for automotive-grade discrete semiconductors.

1.1 Key Features

• EMC package for robust mechanical and thermal performance
• Wide 120° viewing angle for uniform light distribution
• Suitable for all SMT assembly and multiple reflow soldering cycles
• Available in tape and reel packaging (4000 pcs/reel)
• Moisture sensitivity level: 2 (MSL2)
• RoHS compliant and AEC-Q102 qualified

1.2 Target Applications

Automotive lighting – both interior (ambient, indicator) and exterior (tail, stop, turn signal) applications. The wide viewing angle and high reliability make it ideal for use in demanding vehicle environments.

2. Technical Parameter Deep Dive

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

2.2 Absolute Maximum Ratings

Note: The forward voltage measurement tolerance is ±0.1V, color coordinate tolerance ±0.005, and luminous flux tolerance ±10%. All measurements are performed under the manufacturer's standardized environment. The maximum operating current should consider actual heat dissipation to keep the junction temperature below 150°C. At 25°C pulse mode, the photoelectric conversion efficiency is 47%.

2.3 Thermal Characteristics

The thermal resistance values are provided in two forms: real (Rth JS real) and electrical (Rth JS el). The real thermal resistance is typically 12°C/W and represents the actual thermal path from junction to solder point. The electrical thermal resistance is typically 6°C/W, measured with a test current of 350 mA at a constant ambient temperature of 25°C. Proper thermal management is critical to maintain performance and prevent early degradation.

3. Binning System

At IF=350 mA, the LEDs are sorted into bins for forward voltage, luminous flux, and dominant wavelength to ensure consistency in application.

3.1 Forward Voltage Bins

• C0: 2.0 V – 2.2 V
• D0: 2.2 V – 2.4 V
• E0: 2.4 V – 2.6 V

3.2 Luminous Flux Bins

• PA: 55.3 – 61.2 lm
• PB: 61.2 – 67.8 lm
• QA: 67.8 – 75.3 lm
• QB: 75.3 – 83.7 lm
• RA: 83.7 – 93.2 lm

3.3 Dominant Wavelength Bins

• C2: 612.5 – 615 nm
• D1: 615 – 617.5 nm
• D2: 617.5 – 620 nm
• E1: 620 – 622.5 nm
• E2: 622.5 – 625 nm

Bins allow customers to select the exact voltage, flux, or wavelength window required for their specific design. The bin code is marked on the packaging label.

4. Performance Curves Analysis

The datasheet provides several typical curves that help engineers understand the LED behavior under various conditions.

4.1 Forward Voltage vs. Forward Current (Fig. 1-6)

The forward voltage increases linearly with current. At around 350 mA, the voltage is approximately 2.3 V. This curve is essential for designing current regulation circuits.

4.2 Relative Luminous Flux vs. Forward Current (Fig. 1-7)

Light output increases with current but not perfectly linearly. At 350 mA, the relative luminous flux is normalized to 100%. At lower currents, efficiency is higher.

4.3 Junction Temperature vs. Relative Luminous Flux (Fig. 1-8)

As the junction temperature rises, light output decreases. At 125°C, the flux is about 80% of the value at 25°C. Good thermal design is necessary to minimize flux loss at high temperatures.

4.4 Solder Point Temperature vs. Forward Current (Fig. 1-9)

The maximum allowable forward current decreases as the solder point temperature increases. For example, at 120°C solder temperature, the maximum current is around 200 mA.

4.5 Voltage Shift vs. Junction Temperature (Fig. 1-10)

The forward voltage has a negative temperature coefficient. For every 100°C rise, the voltage drops by approximately 0.2 V. This must be accounted for in constant-current drivers to avoid current drift.

4.6 Radiation Diagram (Fig. 1-11)

The radiation pattern is very wide (120° full-width at half-maximum) and near-Lambertian, making it ideal for applications requiring broad illumination.

4.7 Dominant Wavelength Shift vs. Junction Temperature (Fig. 1-12)

The dominant wavelength shifts slightly to longer wavelengths (red shift) with increasing temperature, at a rate of approximately 0.05 nm/°C.

4.8 Spectrum Distribution (Fig. 1-13)

The spectral emission is centered around 620 nm with a narrow full-width at half-maximum of about 20 nm. The peak wavelength is close to the dominant wavelength, ensuring saturated red color.

5. Mechanical and Packaging Information

5.1 Package Dimensions

The LED has a compact outline: 2.70 mm × 2.00 mm × 0.60 mm. The top view shows a rectangular light-emitting area with a cathode mark (C) on the bottom. Detailed side and bottom views indicate polarity: anode (A) and cathode (C) pads. The recommended soldering pattern includes thermal pads for heat dissipation.

5.2 Polarity and Soldering Pad Layout

From the bottom view (Fig. 1-3), the cathode pad is larger (1.30 mm × 0.60 mm) and the anode pad is smaller (1.20 mm × 0.45 mm). The soldering pattern (Fig. 1-5) shows recommended copper areas: 1.40 mm × 1.30 mm for the cathode and 1.20 mm × 1.30 mm for the anode, with a gap of 0.50 mm. All dimensions have a tolerance of ±0.2 mm unless specified.

5.3 Packaging and Labeling

The LEDs are supplied in tape and reel packaging with 4000 pieces per reel. The carrier tape dimensions are: pocket pitch P0=4.0 mm, P1=4.0 mm, P2=2.0 mm, width W=8.0 mm. The reel outer diameter is 180 mm with a hub diameter of 60 mm. Each reel is sealed in a moisture barrier bag with a silica gel desiccant and a humidity indicator card. The label includes part number, lot number, bin codes, quantity, and date.

6. Soldering and Assembly Guide

6.1 Reflow Soldering Profile

Recommended reflow profile (lead-free, based on JEDEC standard):

• Ramp-up rate: 3°C/s max
• Preheat: 150°C to 200°C, 60–120 s
• Time above 217°C (TL): 60 s max
• Peak temperature (TP): 260°C, max 10 s at TP
• Time within 5°C of TP: 30 s max
• Cooling rate: 6°C/s max
• Total time from 25°C to peak: max 8 minutes

The LED can withstand up to two reflow cycles. If more than 24 hours elapse between cycles, baking is required to remove absorbed moisture (60±5°C for >24 hours). Do not apply force on the silicone surface during heating.

6.2 Handling Precautions

• Sulfur and Halogen Control: The environment and mating materials must contain less than 100 ppm sulfur, less than 900 ppm each of bromine and chlorine, and less than 1500 ppm total bromine + chlorine. This prevents chemical attack on the LED package.
• VOC Emissions: Volatile organic compounds from fixture materials can penetrate the silicone encapsulant and cause discoloration under light and heat. Use only compatible adhesives and potting materials that do not outgas.
• ESD Protection: The LED is sensitive to electrostatic discharge (ESD HBM 2 kV). Use grounded workstations and anti-static packaging.
• Cleaning: Use isopropyl alcohol for cleaning if needed. Ultrasonic cleaning is not recommended as it may damage the LED.
• Storage: Unopened bags can be stored at ≤30°C / ≤75% RH for up to one year. After opening, use within 24 hours at ≤30°C / ≤60% RH. If the desiccant has changed color or the storage time is exceeded, bake at 60±5°C for at least 24 hours before use.

6.3 Thermal Design

Because the LED's light output and color stability depend on junction temperature, proper heat sinking is essential. The absolute maximum junction temperature is 150°C. Use adequate PCB copper areas, thermal vias, and forced cooling if necessary to keep TJ below the maximum in the intended operating environment.

7. Reliability and Testing

The product has undergone rigorous reliability testing per AEC-Q102 guidelines. Key tests include:

• Reflow soldering (260°C, 10 s, 2×) – 0/1 failure
• MSL2 preconditioning (85°C/60%RH, 168 h) – 0/1
• Thermal shock (-40°C to 125°C, 1000 cycles) – 0/1
• Life test (Ta=105°C, IF=350 mA, 1000 h) – 0/1
• High temperature / high humidity life test (85°C/85%RH, IF=350 mA, 1000 h) – 0/1

Judgment criteria: Forward voltage must not exceed 1.1× USL, reverse current not exceed 2× USL, and luminous flux must not drop below 0.7× LSL. These tests confirm the LED's robustness for automotive applications.

8. Application Examples and Design Considerations

Automotive Interior Lighting: The wide viewing angle allows for uniform dashboard illumination or ambient light strips. For turn signal applications, the high brightness (up to 93 lm) at 350 mA can meet SAE requirements when properly optics-enabled.

Current Derating: The absolute maximum forward current is 420 mA, but continuous operation at this level requires excellent thermal management. In many automotive designs, the LED is driven at 200–350 mA with derating based on ambient temperature. A series resistor or constant-current driver is essential to prevent thermal runaway.

Multiple LED Strings: When driving multiple LEDs in series, the forward voltage binning (e.g., D0) helps match voltages to reduce power dissipation in the current regulator. For parallel strings, ensure each string has its own current-limiting element to avoid current imbalance.

9. Technology Principle

The LED uses AlGaInP (Aluminum Gallium Indium Phosphide) as the active material. This quaternary compound semiconductor is lattice-matched to a GaAs substrate, enabling high internal quantum efficiency for red and amber wavelengths. The EMC package provides a low thermal resistance path and resistance to yellowing compared to conventional PPA materials. The forward voltage of 2.0–2.6 V is typical for red AlGaInP LEDs. The dominant wavelength is determined by the indium content in the quantum wells; the narrower the bandgap, the longer the wavelength.

10. Industry Trends and Future Outlook

Red LEDs continue to gain importance in automotive lighting due to their efficiency and long life. The trend toward miniaturization (smaller packages like 2.7×2.0 mm) allows more design flexibility. The AEC-Q102 qualification is becoming a mandatory requirement for Tier 1 automotive suppliers. With the rise of ADAS and autonomous driving, red signaling LEDs must meet even stricter reliability and performance standards. The RF-A4E27-R15H-S1 is well positioned to serve these emerging needs.

11. Frequently Asked Questions

Q1: Can I drive this LED at 700 mA peak current continuously?
No. The peak current of 700 mA is allowed only at a 1/10 duty cycle and 10 ms pulse width. Continuous operation must not exceed 420 mA.

Q2: What is the typical lifespan under automotive conditions?
The LED is qualified for 1000 hour life tests, but actual lifespan in the field depends on thermal conditions. With proper thermal management, the LED can last over 50,000 hours.

Q3: Can the LED be cleaned with acetone or other solvents?
Only isopropyl alcohol is recommended. Other solvents may attack the silicone encapsulant. Test compatibility before using any cleaning agent.

Q4: Why is the hot brightness lower than at 25°C?
LED efficiency decreases with temperature due to increased non-radiative recombination. Keep the junction temperature as low as possible.

12. Ordering Information

The standard packaging quantity is 4000 pieces per reel. The reel is 180 mm in diameter and sealed in a moisture barrier bag. For custom binning requirements (specific VF, flux, or wavelength range), contact the distributor or manufacturer. The part number is RF-A4E27-R15H-S1, and the bin code is printed on the label. Always store in accordance with MSL2 guidelines.