PLCC-4 Super Red LED Datasheet - 3.5x3.0x1.9mm - 2.35V - 0.1175W - English Technical Document

1. Product Overview

This document details the specifications for a high-performance Super Red LED in a PLCC-4 (Plastic Leaded Chip Carrier) surface-mount package. The device is engineered primarily for demanding automotive lighting applications, both interior and exterior. Its core advantages include high luminous intensity, a wide viewing angle, and robust construction meeting stringent automotive-grade reliability standards such as AEC-Q102, sulfur resistance (Class A1), and compliance with RoHS, REACH, and halogen-free requirements. The target market encompasses automotive OEMs and tier-1 suppliers developing advanced lighting systems.

2. In-Depth Technical Parameter Analysis

2.1 Photometric and Electrical Characteristics

The LED's performance is characterized under a typical forward current (IF) of 50mA. The typical luminous intensity (IV) is 1800 millicandelas (mcd), with a minimum of 1400 mcd and a maximum of 2800 mcd, indicating potential binning for brightness. The forward voltage (VF) is typically 2.35V, ranging from 2.0V to 2.75V, which is crucial for driver circuit design and power dissipation calculations. The dominant wavelength (λd) is centered at 630 nm (Super Red spectrum), with a range from 627 nm to 639 nm. A key feature is the very wide 120-degree viewing angle (φ), providing broad and uniform illumination suitable for signaling and ambient lighting.

2.2 Absolute Maximum Ratings and Thermal Management

Critical limits must not be exceeded to ensure device longevity. The absolute maximum continuous forward current is 70 mA, with a surge current (IFM) of 100 mA for pulses ≤10 μs. The maximum junction temperature (TJ) is 125°C, and the operating temperature range (Topr) is from -40°C to +110°C, suitable for harsh automotive environments. Thermal management is vital; the thermal resistance from junction to solder point (Rth JS) is specified with two values: a \"real\" measurement (Typ. 70 K/W, Max 95 K/W) and an \"electrical\" measurement (Typ. 50 K/W, Max 67 K/W). This parameter directly links power dissipation (Pd = VF * IF) to the temperature rise at the junction. The derating curve shows the forward current must be reduced as the solder pad temperature increases, e.g., to 57 mA at 110°C pad temperature.

3. Binning System Explanation

To ensure consistency in production, LEDs are sorted into bins based on key parameters.

3.1 Luminous Intensity Binning

Three intensity groups are defined: AB (1400-1800 mcd), BA (1800-2240 mcd), and BB (2240-2800 mcd). Corresponding luminous flux ranges (for reference) are also provided.

3.2 Dominant Wavelength Binning

Wavelength is binned in 3-nanometer steps, from 2730 (627-630 nm) to 3639 (636-639 nm). This allows selection of LEDs with very specific color points.

3.3 Forward Voltage Binning

Voltage bins are defined in 0.25V increments, from 1720 (1.75-2.00V) to 2527 (2.50-2.75V). Matching VF bins can be important for current balancing in multi-LED arrays.

4. Performance Curve Analysis

4.1 IV Curve and Relative Intensity

The Forward Current vs. Forward Voltage graph shows a characteristic exponential relationship. The Relative Luminous Intensity vs. Forward Current curve is nearly linear up to the typical 50mA, indicating good efficiency within the normal operating range.

4.2 Temperature Dependence

Several graphs illustrate thermal performance. The Relative Forward Voltage vs. Junction Temperature has a negative coefficient, decreasing by approximately 0.2V over a 150°C range, which can be used for temperature sensing. The Relative Luminous Intensity vs. Junction Temperature shows output decreasing as temperature rises, a critical factor for thermal design. The Dominant Wavelength shift vs. Junction Temperature indicates a red shift (increase in wavelength) with heating, which is typical for AlInGaP LEDs.

4.3 Spectral Distribution and Radiation Pattern

The Wavelength Characteristics graph shows a narrow spectral peak around 630 nm, confirming the pure red color. The Typical Diagram of Radiation Characteristics visually represents the 120-degree viewing angle pattern.

4.4 Pulse Handling Capability

A graph details the permissible pulse current vs. pulse width for various duty cycles. This is essential for designing pulsed operation circuits, such as in PWM dimming or communication systems.

5. Mechanical and Package Information

The LED uses a standard PLCC-4 package. The mechanical drawing (implied by section reference) would specify the exact dimensions (typically around 3.5mm x 3.0mm x 1.9mm), lead spacing, and lens geometry. Polarity is indicated by the package shape and/or a marking on the top or bottom. A recommended soldering pad layout is provided to ensure reliable solder joint formation and proper heat dissipation during reflow.

6. Soldering and Assembly Guidelines

The device is rated for reflow soldering at a peak temperature of 260°C for 30 seconds, following a standard profile with controlled ramp-up, soak, and cooling rates. Precautions include avoiding mechanical stress on the lens, preventing contamination, and ensuring the thermal pad is properly soldered for optimal heat transfer. Storage conditions should be within the specified -40°C to +110°C range in a dry environment.

7. Packaging and Ordering Information

Packaging is typically on tape and reel for automated assembly. The part number structure is decoded as follows: 67-41 (Family), SR (Super Red color), 050 (50mA test current), 1 (Gold lead frame), H (High brightness level), AM (Automotive application). This coding allows precise identification of the device's performance characteristics.

8. Application Recommendations

8.1 Typical Application Scenarios

Primary applications are automotive exterior lighting (e.g., center high-mount stop lights - CHMSL, rear combination lamps, side markers) and interior lighting (e.g., dashboard backlighting, switch illumination, ambient lighting). The high brightness and wide angle make it suitable for both direct view and light guide/piping applications.

8.2 Design Considerations

Designers must consider current limiting, typically using a constant-current driver or a resistor in series with a stable voltage source. Thermal management is paramount; the PCB layout must provide an adequate thermal pad and possibly thermal vias to dissipate heat. The ESD sensitivity of 2kV (HBM) necessitates standard ESD handling precautions during assembly. For sulfur-rich environments, the Class A1 sulfur robustness rating should be verified against the specific application environment.

9. Technical Comparison and Differentiation

Compared to standard red LEDs, this device's \"Super Red\" formulation offers higher luminous intensity and a more saturated color. The PLCC-4 package provides a more robust mechanical and thermal interface than smaller packages like 0603 or 0805. The combination of AEC-Q102 qualification, wide temperature range, and sulfur resistance specifically targets it for automotive use, differentiating it from commercial-grade components which may not survive the harsh automotive lifecycle.

10. Frequently Asked Questions (Based on Technical Parameters)

Q: What driver current should I use?
A: The typical operating current is 50mA, providing the specified 1800mcd. It can be driven up to 70mA continuously for higher output, but thermal derating must be applied as shown in the graph. Do not operate below 5mA.

Q: How do I interpret the two different thermal resistance values?
A: The \"real\" Rth JS is measured physically and is more conservative. The \"electrical\" Rth JS is derived from electrical parameters and may be lower. For reliable thermal design, using the higher \"real\" value (Max 95 K/W) is recommended.

Q: Can I use PWM for dimming?
A: Yes, the pulse handling capability graph provides guidelines. For example, at a 1% duty cycle (D=0.01), short pulses significantly higher than 70mA are permissible, enabling effective PWM dimming.

Q: Is a heatsink required?
A> For continuous operation at 50mA or above, especially in high ambient temperatures, effective heat sinking via the PCB's thermal pad is essential to keep the junction temperature below 125°C and maintain light output and longevity.

11. Practical Design and Usage Case

Case: Designing a CHMSL (Center High-Mount Stop Light)
A designer needs 15 LEDs for a CHMSL array. They select LEDs from the BA intensity bin (1800-2240 mcd) and the 3033 wavelength bin (630-633 nm) for color consistency. Using a 13.8V vehicle electrical system and targeting 50mA per LED, they design a circuit with three parallel strings of 5 LEDs each. A series resistor is calculated for each string based on the typical VF of 2.35V (5 * 2.35V = 11.75V). The resistor value is (13.8V - 11.75V) / 0.05A = 41 Ohms. A PCB with a solid copper pour under the LED's thermal pad is designed to act as a heatsink, keeping the solder pad temperature below 80°C to allow full 50mA operation as per the derating curve.

12. Operating Principle Introduction

This is an Aluminium Indium Gallium Phosphide (AlInGaP) semiconductor-based light-emitting diode. When a forward voltage exceeding its bandgap energy is applied, electrons and holes recombine in the active region, releasing energy in the form of photons. The specific composition of the AlInGaP layers determines the bandgap energy, which corresponds to the red wavelength of light emitted (around 630 nm). The epoxy lens of the PLCC package shapes the light output to achieve the 120-degree viewing angle.

13. Technology Trends and Developments

The trend in automotive LEDs is towards higher efficiency (more lumens per watt), increased power density, and greater integration (e.g., multi-chip packages, integrated drivers). There is also a push for enhanced color stability over temperature and lifetime. Furthermore, new package formats with improved thermal performance, such as ceramic substrates or advanced molded packages, are emerging to handle the higher power levels required for applications like adaptive driving beams (ADB) and micro-projection. The adherence to standards like AEC-Q102 and specific chemical resistance (sulfur, humidity) continues to be a critical differentiator for automotive-grade components.