PLCC-2 Red LED Datasheet - 120° Viewing Angle - 2.0V Typ - 40mW - Automotive Grade - English Technical Document

1. Product Overview

This document details the specifications for a high-performance, surface-mount red LED encapsulated in a PLCC-2 (Plastic Leaded Chip Carrier) package. The device is engineered primarily for the demanding environment of automotive electronics, offering a combination of high luminous output, wide viewing angle, and robust reliability certifications.

The core advantages of this component include its qualification to the AEC-Q102 standard for discrete optoelectronic devices, ensuring its suitability for automotive applications. It features sulfur robustness classified as A1, making it resistant to corrosive atmospheres. Furthermore, the product complies with RoHS, REACH, and halogen-free directives, aligning with global environmental and safety regulations. Its primary target markets are automotive interior and exterior lighting systems, including but not limited to dashboard clusters, indicator lights, and various illumination functions within the vehicle.

2. In-Depth Technical Parameter Analysis

2.1 Photometric and Optical Characteristics

The LED's key photometric performance is defined under a typical forward current (I_F) of 20mA. The typical luminous intensity (I_V) is 1400 millicandelas (mcd), with a specified range from a minimum of 900 mcd to a maximum of 2240 mcd depending on the binning selection. This high brightness is achieved while maintaining a very wide viewing angle (φ) of 120 degrees, defined as the off-axis angle where luminous intensity drops to half of its peak value. The dominant wavelength (λ_d) is in the red spectrum, ranging from 612 nm to 627 nm, which determines the perceived color of the light emitted.

2.2 Electrical and Thermal Parameters

The electrical characteristics are centered around a typical forward voltage (V_F) of 2.00 volts at 20mA, with permissible limits between 1.75V and 2.75V. The absolute maximum ratings define the operational boundaries: a maximum continuous forward current (I_F) of 50 mA, a maximum power dissipation (P_d) of 137 mW, and a surge current (I_FM) capability of 100 mA for pulses ≤ 10 µs. The device is not designed for reverse bias operation.

Thermal management is critical for LED performance and longevity. The thermal resistance from the junction to the solder point is specified through two methods: a real measurement (R_{th JS real}) with a typical value of 120 K/W (max 160 K/W) and an electrical measurement (R_{th JS el}) with a typical value of 100 K/W (max 120 K/W). The maximum permissible junction temperature (T_J) is 125°C, with an operating temperature range (T_opr) from -40°C to +110°C.

3. Binning System Explanation

To ensure consistency in application design, the LEDs are sorted into bins based on key parameters. This allows designers to select components that meet specific tolerance requirements for their circuits.

3.1 Luminous Intensity Binning

Luminous intensity is grouped into four primary bins: V2 (900-1120 mcd), AA (1120-1400 mcd), AB (1400-1800 mcd), and BA (1800-2240 mcd). The corresponding luminous flux ranges are also provided for reference, measured with a tolerance of ±8%.

3.2 Dominant Wavelength Binning

The dominant wavelength, which defines the color point, is binned in 3-nanometer steps. The bins are labeled 1215 (612-615 nm), 1518 (615-618 nm), 1821 (618-621 nm), 2124 (621-624 nm), and 2427 (624-627 nm), with a measurement tolerance of ±1 nm.

3.3 Forward Voltage Binning

Forward voltage is categorized into four bins to aid in driver design and current matching in multi-LED arrays: 1720 (1.75-2.00V), 2022 (2.00-2.25V), 2225 (2.25-2.50V), and 2527 (2.50-2.75V). The measurement tolerance is ±0.05V.

4. Performance Curve Analysis

The datasheet provides several graphs essential for understanding the LED's behavior under different operating conditions.

4.1 IV Curve and Relative Intensity

The Forward Current vs. Forward Voltage graph shows the exponential relationship typical of diodes. The Relative Luminous Intensity vs. Forward Current curve demonstrates that light output increases super-linearly with current before potentially saturating, emphasizing the importance of constant-current drive.

4.2 Temperature Dependence

Key graphs illustrate the LED's sensitivity to temperature. The Relative Luminous Intensity vs. Junction Temperature curve shows a decrease in light output as temperature increases. Conversely, the Relative Forward Voltage vs. Junction Temperature graph shows a negative temperature coefficient, where V_F decreases linearly with rising temperature. This property can sometimes be used for temperature sensing. The Dominant Wavelength Shift vs. Junction Temperature graph indicates a shift towards longer wavelengths (red shift) as temperature increases.

4.3 Spectral Distribution and Derating

The Relative Spectral Distribution graph confirms the monochromatic red output with a peak in the ~625 nm region. The Forward Current Derating Curve is crucial for thermal design, showing the maximum allowable continuous current as a function of the solder pad temperature. For example, at the maximum solder pad temperature of 110°C, the forward current must be derated to 34 mA. The Permissible Pulse Handling Capability chart defines the safe operating area for pulsed currents at various duty cycles.

5. Mechanical, Packaging, and Assembly Information

5.1 Mechanical Dimensions and Polarity

The component uses a standard PLCC-2 surface-mount package. The specific mechanical drawing (implied by section reference) would detail the length, width, height, and lead spacing. The part number includes an "R" indicating reverse polarity configuration; the cathode is typically indicated by a notch or a marked corner on the package. Designers must consult the detailed dimension drawing for exact measurements and footprint.

5.2 Soldering Pad Design and Reflow Profile

A recommended soldering pad layout is provided to ensure proper solder joint formation, thermal relief, and mechanical stability. The reflow soldering profile is specified with a peak temperature of 260°C for 30 seconds, which is consistent with standard lead-free (Pb-free) soldering processes. Adherence to this profile is necessary to prevent thermal damage to the LED package or the die attach.

5.3 Packaging and Handling Precautions

The device has a Moisture Sensitivity Level (MSL) of 2. This means the component can be stored for up to one year at ≤ 30°C / 60% relative humidity before requiring baking prior to reflow soldering. Standard ESD (Electrostatic Discharge) precautions must be observed, as the device is rated for 2 kV Human Body Model (HBM). Packaging information details the reel and tape specifications for automated assembly.

6. Application Guidelines and Design Considerations

6.1 Typical Application Scenarios

This LED is explicitly designed for automotive applications:
Interior Lighting: Dashboard backlighting, switch illumination, ambient lighting, and infotainment system indicators.
Exterior Lighting: Center High-Mount Stop Lights (CHMSL), side marker lights, and other signal functions where high brightness and wide angle are beneficial.
Clusters: Warning lights, tell-tale indicators, and gauge illumination.

6.2 Critical Design Considerations

• Current Drive: Always use a constant-current driver or a current-limiting resistor. The typical operating point is 20mA, but the design must ensure the current never exceeds the absolute maximum of 50mA under any condition, considering derating for temperature.
• Thermal Management: The thermal resistance path is through the solder pads. Ensure the PCB has adequate copper pour or thermal vias to dissipate heat, especially when operating at high ambient temperatures or currents.
• ESD Protection: Implement standard ESD control measures during handling and assembly. While rated for 2kV HBM, additional protection on the PCB may be necessary if the LED is exposed to user-accessible interfaces.
• Optical Design: The 120-degree viewing angle provides a very wide beam. For applications requiring a more focused beam, secondary optics (lenses) will be required.

7. Ordering Information and Part Number Decoding

The part number follows a specific structure: 67-21R-UR0201H-AM.
67-21: Product family.
R: Reverse polarity.
UR: Color code (Red).
020: Test current (20 mA).
1: Lead frame type.
H: Brightness level (High). Other levels include M (Medium) and L (Low).
AM: Designates automotive application grade.

When ordering, specific bin codes for luminous intensity, wavelength, and forward voltage may need to be specified to obtain the desired performance characteristics.

8. Technical Comparison and Differentiation

Compared to standard commercial-grade PLCC-2 LEDs, this device's key differentiators are its automotive qualifications. The AEC-Q102 certification involves rigorous stress testing for temperature cycling, humidity, high-temperature operating life, and other conditions specific to automotive environments. The sulfur robustness (Class A1) is another critical feature for automotive use, where exposure to sulfur-containing gases from tires, fuels, or atmospheric pollution can corrode silver-plated components and lead to failure. The wide operating temperature range (-40°C to +110°C) also exceeds typical commercial specifications.

9. Frequently Asked Questions (FAQ)

Q: What is the minimum forward current for this LED?
A: The datasheet specifies a minimum forward current of 5 mA. Operation below this current is not recommended in the derating graph.

Q: Can I drive this LED with a 3.3V supply without a resistor?
A: No. With a typical V_F of 2.0V, connecting it directly to 3.3V would cause excessive current flow, likely exceeding the maximum rating and destroying the LED. A series current-limiting resistor or constant-current driver is always required.

Q: How does the luminous intensity change with temperature?
A: As shown in the performance graphs, luminous intensity decreases as junction temperature increases. At the maximum junction temperature of 125°C, the relative luminous intensity is significantly lower than at 25°C. Thermal design is crucial to maintain brightness.

Q: What does "MSL: 2" mean for my production process?
A: MSL 2 means the components are packaged in a moisture-barrier bag with a humidity indicator card. Once the bag is opened, the components must be soldered within 1 year if stored at ≤ 30°C/60% RH. If exposed to higher humidity or exceeded the floor life, baking is required before reflow to prevent "popcorning" damage during soldering.

10. Design and Usage Case Study

Scenario: Designing a High-Reliability Dashboard Warning Indicator.
A designer needs a red "Engine Check" warning light that is clearly visible from a wide range of driver positions, operates reliably over the vehicle's 15-year lifespan, and functions in extreme climates.

Component Selection: This AEC-Q102 qualified LED is chosen for its reliability, wide 120° viewing angle ensuring visibility, and robust construction.
Circuit Design: The LED is driven by the vehicle's 12V system via a constant-current driver IC set to 20mA. The driver provides protection against load dump transients and reverse polarity events common in automotive electrical systems.
Thermal Design: The PCB is designed with a thermal pad connected to a large copper plane to dissipate heat, keeping the solder pad temperature well below 110°C even in a hot cabin environment.
Optical Design: A simple diffuser lens is placed over the LED to soften the light point and integrate it aesthetically into the cluster panel.
This approach leverages the LED's key specifications to create a durable, high-performance solution meeting automotive standards.

11. Operating Principle Introduction

This device is a Light Emitting Diode (LED), a semiconductor p-n junction diode. When a forward voltage exceeding the diode's threshold is applied, electrons from the n-type region recombine with holes from the p-type region within the active layer. This recombination process releases energy in the form of photons (light). The specific material composition of the semiconductor (typically based on Aluminum Gallium Indium Phosphide - AlGaInP for red LEDs) determines the wavelength, and thus the color, of the emitted light. The PLCC-2 package houses the semiconductor die, provides electrical connections via lead frames, and includes a molded epoxy lens that shapes the light output and protects the die.

12. Technology Trends and Developments

The trend in automotive LED lighting continues towards higher efficiency (more lumens per watt), increased power density, and greater integration. While this component is a discrete device, there is a growing use of multi-die packages and LED modules that integrate driver electronics and optics. Furthermore, advancements in phosphor technology and direct-emitting semiconductors are expanding color gamuts and improving color rendering for interior ambient lighting. The demand for enhanced reliability, longer lifetimes, and performance under higher temperature hoods (for exterior applications) continues to drive material science and packaging innovation in automotive-grade LEDs.