PLCC-4 Red LED Datasheet - Package 3.5x2.8x1.9mm - Voltage 2.25V - Power 112.5mW - English Technical Document

1. Product Overview

This document details the specifications for a high-performance, surface-mount red LED in a PLCC-4 (Plastic Leaded Chip Carrier) package. The device is engineered primarily for demanding automotive lighting environments, both interior and exterior. Its core advantages include a high typical luminous intensity of 3550 millicandelas (mcd) at a standard drive current of 50mA, a wide 120-degree viewing angle for excellent visibility, and robust construction meeting key automotive and environmental standards.

The LED is qualified to the AEC-Q102 standard, ensuring reliability for automotive electronic components. It also features sulfur robustness (Class A1), making it resistant to corrosive atmospheres, and complies with RoHS, REACH, and halogen-free directives. This combination of high output, reliability, and compliance makes it a suitable choice for modern vehicle lighting systems.

2. In-Depth Technical Parameter Analysis

2.1 Photometric and Electrical Characteristics

The key operating parameters, measured under typical conditions (T_s=25°C, I_F=50mA), define the LED's performance envelope:

• Forward Current (I_F): The recommended operating current is 50mA, with an absolute maximum rating of 70mA. A minimum current of 5mA is specified for proper operation.
• Luminous Intensity (I_V): The typical value is 3550 mcd, with a minimum of 2240 mcd and a maximum of 5600 mcd at 50mA. The luminous flux measurement has a tolerance of ±8%.
• Forward Voltage (V_F): Typically 2.25V, ranging from a minimum of 1.75V to a maximum of 2.75V at 50mA, with a measurement tolerance of ±0.05V.
• Viewing Angle (2φ_½): 120 degrees, with a tolerance of ±5 degrees. This is the full angle where luminous intensity drops to half of its peak axial value.
• Dominant Wavelength (λ_d): For this red LED, the dominant wavelength falls within the range of 612nm to 627nm, with a measurement tolerance of ±1nm.

2.2 Thermal Characteristics

Thermal management is critical for LED performance and longevity. Two thermal resistance values are provided:

• Real Thermal Resistance (R_{th JS real}): Typical 70 K/W, max 95 K/W. This is measured directly from the junction to the solder point.
• Electrical Thermal Resistance (R_{th JS el}): Typical 50 K/W, max 67 K/W. This is an electrically derived value used for certain calculation models.
• Junction Temperature (T_J): The maximum allowable junction temperature is 125°C.
• Operating Temperature (T_opr): The ambient temperature range for operation is -40°C to +110°C.

2.3 Absolute Maximum Ratings

These ratings define the stress limits beyond which permanent damage may occur. They must not be exceeded under any conditions.

• Power Dissipation (P_d): 192 mW.
• Surge Current (I_FM): 100 mA for pulses ≤10μs with a duty cycle (D) of 0.005.
• Reverse Voltage (V_R): This device is not designed for reverse bias operation.
• ESD Sensitivity (HBM): 2 kV, tested per the Human Body Model (R=1.5kΩ, C=100pF).
• Soldering Temperature: Withstands reflow soldering at 260°C for 30 seconds.

3. Performance Curve Analysis

3.1 Spectral and Radiation Characteristics

The Relative Spectral Distribution graph shows the LED emits light primarily in the red region of the spectrum, centered around its dominant wavelength. The Typical Diagram Characteristics of Radiation illustrates the spatial intensity distribution, confirming the 120-degree viewing angle where intensity falls to 50% of the on-axis peak.

3.2 Current vs. Voltage and Intensity

The Forward Current vs. Forward Voltage (I-V) curve exhibits the typical exponential relationship of a diode. At 50mA, the voltage is approximately 2.25V. The Relative Luminous Intensity vs. Forward Current graph shows that light output increases with current but may become sub-linear at higher currents due to thermal effects.

3.3 Temperature Dependence

Several graphs detail performance changes with temperature:

• Relative Forward Voltage vs. Junction Temperature: The forward voltage decreases linearly with increasing junction temperature, a characteristic used for temperature sensing.
• Relative Luminous Intensity vs. Junction Temperature: Light output decreases as temperature rises. Maintaining a low junction temperature is essential for consistent brightness.
• Dominant Wavelength Shift vs. Junction Temperature: The peak emission wavelength shifts with temperature, which is important for color-critical applications.
• Forward Current Derating Curve: This crucial graph shows the maximum allowable forward current must be reduced as the solder pad temperature increases. For example, at the maximum solder pad temperature of 110°C, the current must be derated to 57mA.

3.4 Pulse Operation

The Permissible Pulse Handling Capability chart defines the safe operating area for pulsed current. It shows that for very short pulse widths (t_p), higher peak currents (I_F) are permissible, depending on the duty cycle (D).

4. Binning System Explanation

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

4.1 Luminous Intensity Bins

LEDs are grouped by their measured luminous intensity at the typical current. Bins range from BB (2240-2800 mcd) to CB (3550-4500 mcd). The typical part (3550 mcd) falls into the CA bin (2800-3550 mcd). Corresponding luminous flux values in lumens are provided for reference.

4.2 Dominant Wavelength Bins

The dominant wavelength is binned in 3nm steps, from 1215 (612-615nm) to 2427 (624-627nm). This allows selection of LEDs with very specific color points.

4.3 Forward Voltage Bins

Forward voltage is binned in 0.25V steps, from code 1720 (1.75-2.00V) to 2527 (2.50-2.75V). Matching V_F bins can help in designing balanced parallel LED strings.

5. Mechanical and Packaging Information

5.1 Mechanical Dimensions

The LED uses a standard PLCC-4 surface-mount package. The typical dimensions are approximately 3.5mm in length, 2.8mm in width, and 1.9mm in height (including the dome). Detailed dimensional drawings with tolerances would be found in the dedicated mechanical drawing section of the full datasheet.

5.2 Polarity Identification

The PLCC-4 package has a chamfered or notched corner that indicates the cathode (negative) pin. Correct orientation is essential for circuit operation.

5.3 Recommended Soldering Pad Layout

A land pattern design is recommended to ensure reliable soldering, proper thermal dissipation, and alignment during the reflow process. This pattern typically includes pads for the four electrical leads and a central thermal pad for heat sinking.

6. Soldering and Assembly Guidelines

6.1 Reflow Soldering Profile

The component is compatible with standard infrared or convection reflow soldering processes. The specified profile includes a preheat zone, a soak zone, a reflow zone with a peak temperature not exceeding 260°C for 30 seconds, and a controlled cooling zone. Adhering to this profile prevents thermal shock and ensures solder joint integrity.

6.2 Precautions for Use

• ESD Protection: Although rated for 2kV HBM, standard ESD handling precautions should be observed during assembly.
• Current Limiting: Always use a series resistor or constant-current driver to limit the forward current to the desired value, never connecting directly to a voltage source.
• Thermal Design: Implement adequate PCB copper area or heatsinking, especially when operating at high currents or in high ambient temperatures, to keep the junction temperature within limits.
• Cleaning: Use compatible cleaning solvents that do not damage the plastic package or lens.

7. Packaging and Ordering Information

7.1 Part Number Decoding

The part number 67-41-UR050 1H-AM is structured as follows:
67-41: Product family.
UR: Color (Red).
050: Test current (50mA).
1: Lead frame type (1=Gold).
H: Brightness level (High).
AM: Designates Automotive application.

7.2 Standard Packaging

The LEDs are typically supplied on embossed tape and reel for compatibility with automated pick-and-place assembly equipment. Standard reel quantities are industry-standard, such as 2000 or 4000 pieces per reel.

8. Application Suggestions

8.1 Typical Application Scenarios

• Automotive Exterior Lighting: Daytime running lights (DRLs), side marker lights, center high-mount stop lights (CHMSL), and interior illumination for badges or accents.
• Automotive Interior Lighting: Dashboard backlighting, switch illumination, footwell lighting, and ambient lighting.
• General Indicator Applications: Status indicators in industrial equipment, consumer electronics, or signage requiring high brightness and reliability.

8.2 Design Considerations

• Driver Selection: For automotive applications, consider drivers that can handle load-dump, reverse battery protection, and PWM dimming if required.
• Optical Design: The wide viewing angle may require secondary optics (lenses, light guides) to shape the beam for specific applications like DRLs.
• Series/Parallel Configuration: When connecting multiple LEDs, consider voltage binning for parallel strings and ensure the driver can provide the total required current and voltage.

9. Technical Comparison and Differentiation

Compared to standard non-automotive PLCC-4 LEDs, this device offers key advantages:

• Automotive Qualification (AEC-Q102): Undergoes rigorous stress testing for temperature cycling, humidity, and operational life, ensuring reliability in the harsh automotive environment.
• Sulfur Robustness (Class A1): The materials and construction resist corrosion from sulfur-containing atmospheres, common in some geographic regions.
• Extended Temperature Range: Rated for operation from -40°C to +110°C, exceeding the range of typical commercial-grade LEDs.
• High Luminous Intensity: The 3550 mcd typical output at 50mA is higher than many standard red PLCC-4 LEDs, providing more light for a given current.

10. Frequently Asked Questions (FAQs)

10.1 What is the recommended operating current?

The typical operating current is 50mA. It can be operated from 5mA up to the absolute maximum of 70mA, but performance parameters (intensity, voltage) are specified at 50mA. Always refer to the derating curve if operating at high ambient temperatures.

10.2 How do I calculate the series resistor value?

Use Ohm's Law: R = (V_supply - V_F) / I_F. For a 12V automotive supply and using the typical V_F of 2.25V at 50mA: R = (12V - 2.25V) / 0.05A = 195 Ohms. Choose the nearest standard value (e.g., 200 Ohms) and ensure the resistor's power rating is sufficient (P = I²R = 0.5W).

10.3 Can this LED be used for PWM dimming?

Yes, LEDs are ideal for PWM dimming. Ensure the PWM frequency is high enough to avoid visible flicker (typically >200Hz). The driver must be capable of switching the required current at the chosen frequency.

10.4 Why is thermal management important?

Excessive junction temperature reduces light output (lumen depreciation), shortens operational lifetime, and can cause a shift in dominant wavelength. Proper heatsinking maintains performance and reliability.

11. Practical Design and Usage Cases

11.1 Design Case: Automotive Center High-Mount Stop Light (CHMSL)

For a CHMSL requiring high brightness and fast response, multiple LEDs can be arranged in a line. Using a constant-current driver rated for the automotive voltage range ensures consistent brightness regardless of battery voltage fluctuations. The wide viewing angle of 120 degrees provides excellent visibility from various angles behind the vehicle. The AEC-Q102 qualification ensures the lights will function reliably over the vehicle's lifetime under all climatic conditions.

11.2 Design Case: Industrial Status Indicator Panel

In an industrial control panel, these LEDs can serve as high-brightness status or fault indicators. Their sulfur robustness makes them suitable for environments with potential chemical exposure. The PLCC-4 package allows for compact, surface-mount design on the PCB. Designers can select specific wavelength bins to maintain a consistent red color across all indicators on the panel.

12. Operating Principle Introduction

This device is a light-emitting diode (LED). It operates on the principle of electroluminescence in a semiconductor material. When a forward voltage is applied across the p-n junction, electrons and holes recombine, releasing energy in the form of photons (light). The specific semiconductor materials used determine the color of the emitted light; in this case, materials that produce red light with a dominant wavelength between 612-627nm. The plastic package incorporates a molded epoxy lens that shapes the light output and provides environmental protection.

13. Technology Trends

The trend in automotive and high-reliability LEDs continues toward higher efficacy (more light output per watt of electrical input), improved thermal performance allowing for higher drive currents in smaller packages, and enhanced color consistency and saturation. There is also a focus on developing packages that facilitate better optical control and integration with secondary optics. The drive for miniaturization persists, alongside the need for packages that simplify thermal management for the end designer, such as those with exposed thermal pads or advanced substrate materials.