2020 Cube Light Red LED Datasheet - SMD Package - 2.2V Typ - 140mA - 26 lm - English Technical Document

1. Product Overview

This document details the specifications for the 2020 Cube Light, a high-brightness red Surface-Mount Device (SMD) LED engineered primarily for demanding automotive lighting environments. The component is characterized by its compact 2020 footprint, robust construction, and performance parameters tailored for reliability under harsh operating conditions. Its core advantages include compliance with stringent automotive qualification standards, a wide viewing angle for uniform illumination, and environmental compliance certifications.

The primary target market is the automotive industry, where it is suitable for various interior and exterior signal lighting functions. The design prioritizes long-term stability, thermal performance, and resistance to environmental stressors commonly encountered in vehicle applications.

2. Technical Parameter Deep-Dive

2.1 Photometric & Optical Characteristics

The LED's key photometric performance is defined at a standard test current of 140mA. The typical luminous flux output is 26 lumens (lm), with a specified minimum of 23 lm and a maximum of 39 lm, accounting for production binning. The dominant wavelength is typically 614 nm, placing it firmly in the red spectrum, with a range from 612 nm to 627 nm. A wide 120-degree viewing angle (with a ±5° tolerance) ensures a broad radiation pattern, which is beneficial for applications requiring wide-area illumination or visibility from multiple angles.

2.2 Electrical Parameters

The forward voltage (Vf) at the 140mA test condition has a typical value of 2.2V, ranging from a minimum of 1.75V to a maximum of 2.75V. The absolute maximum continuous forward current is rated at 250 mA. For surge conditions (pulse width ≤10 μs, duty cycle 0.005), the device can withstand a surge current (IFM) of up to 1000 mA. It is crucial to note that this LED is not designed for reverse bias operation.

2.3 Thermal & Reliability Ratings

Thermal management is critical for LED longevity. The junction-to-solder point thermal resistance is specified with two values: an electrical method result of 16-18 K/W and a real method result of 23-26 K/W. The maximum permissible junction temperature (Tj) is 150°C. The device is rated for an operating temperature range of -40°C to +125°C, matching the extremes required for automotive use. It features Electrostatic Discharge (ESD) protection rated at 2 kV (Human Body Model). The component is also qualified for lead-free reflow soldering with a peak temperature of 260°C for 30 seconds.

3. Binning System Explanation

To ensure consistency in production, LEDs are sorted into performance bins. Understanding these bins is essential for design consistency.

3.1 Luminous Flux Binning

LEDs are grouped based on their light output at 140mA. The primary bins are E9 (23-27 lm), F1 (27-33 lm), and F2 (33-39 lm). The typical value of 26 lm falls within the E9 bin.

3.2 Forward Voltage Binning

Components are also binned according to their forward voltage drop. Key bins include 1720 (1.75-2.0V), 2022 (2.0-2.25V), 2225 (2.25-2.5V), and 2527 (2.5-2.75V). The typical 2.2V value corresponds to the 2022 bin.

3.3 Dominant Wavelength Binning

The color (wavelength) is tightly controlled through bins such as 1215 (612-615 nm), 1518 (615-618 nm), up to 2427 (624-627 nm). The typical 614 nm is in the 1215 bin.

4. Performance Curve Analysis

4.1 IV Curve and Relative Luminous Flux

The Forward Current vs. Forward Voltage graph shows a characteristic exponential relationship. The Relative Luminous Flux vs. Forward Current curve indicates that light output increases with current but will eventually saturate and can degrade efficiency and lifetime at higher currents beyond recommendation.

4.2 Temperature Dependence

The Relative Luminous Flux vs. Junction Temperature graph is critical for thermal design. It shows that light output decreases as junction temperature increases. The Dominant Wavelength Shift vs. Junction Temperature graph indicates the color will shift (typically towards longer wavelengths) as temperature rises, which must be considered in color-critical applications.

4.3 Spectral Distribution and Derating

The Relative Spectral Distribution graph confirms a narrow-band red emission peak. The Forward Current Derating Curve mandates reducing the maximum allowable continuous current as the solder pad temperature increases to prevent exceeding the maximum junction temperature. For example, at a pad temperature of 125°C, the current must be derated to 250 mA.

5. Mechanical & Package Information

The component uses a standard 2020 SMD package (2.0mm x 2.0mm footprint). The mechanical drawing specifies the exact dimensions, including overall height, lead frame details, and lens geometry. Tolerances are typically ±0.1mm unless otherwise noted. A recommended soldering pad layout is provided to ensure proper solder joint formation, thermal transfer, and mechanical stability during reflow and operation. The polarity is indicated by a specific marking or pin configuration on the component body, which must be observed during placement.

6. Soldering & Assembly Guidelines

The LED is compatible with standard lead-free reflow soldering processes. A detailed reflow soldering profile is provided, specifying the critical parameters: preheat slope, soak time and temperature, time above liquidus (TAL), peak temperature (260°C max for 30 seconds), and cooling rate. Adherence to this profile is essential to prevent thermal shock, solder joint defects, or damage to the LED package. General precautions include using appropriate ESD protection during handling, avoiding mechanical stress on the lens, and ensuring the soldering environment is free from contaminants like sulfur.

7. Packaging & Ordering Information

The parts are supplied in standard tape-and-reel packaging suitable for automated pick-and-place assembly machines. The packaging information details reel dimensions, pocket spacing, and orientation. The part number follows a specific structure: 2020 - UR - 140 - D - M - AM.
- 2020: Product family.
- UR: Color (Red).
- 140: Test Current in mA.
- D: Lead Frame Type (Au + White glue).
- M: Brightness Level (Medium).
- AM: Automotive application designation.

8. Application Suggestions

8.1 Typical Application Scenarios

The primary application is automotive lighting. This includes, but is not limited to, center high-mount stop lights (CHMSL), rear combination lamps (tail/stop lights), side marker lights, and interior ambient lighting. Its AEC-Q102 qualification and wide temperature range make it suitable for these harsh environments.

8.2 Design Considerations

Driver Circuit: A constant-current driver is strongly recommended to ensure stable light output and prevent thermal runaway, as LED forward voltage has a negative temperature coefficient.
Thermal Management: The PCB layout must facilitate heat dissipation. Use the recommended solder pad design, ensure adequate copper area connected to the thermal pad, and consider the overall system thermal path to keep the solder pad temperature within safe limits for the desired operating current.
Optical Design: The 120° viewing angle may require secondary optics (lenses, light guides) to shape the beam for specific applications. The potential for wavelength shift with temperature should be evaluated for color-sensitive uses.

9. Technical Comparison & Differentiation

Compared to generic commercial-grade LEDs, this component's key differentiators are its automotive-grade qualifications (AEC-Q102), extended operating temperature range (-40°C to +125°C), and specific reliability testing (e.g., Sulfur Test Class A1). It also complies with Halogen-Free requirements, which is increasingly important for environmental and reliability reasons in automotive electronics. The combination of a medium brightness level (26 lm typ) with robust construction offers a balanced solution for applications where reliability is prioritized over ultimate brightness.

10. Frequently Asked Questions (Based on Technical Parameters)

Q: Can I drive this LED at its absolute maximum current of 250mA continuously?
A: Not necessarily. The 250mA rating is the absolute maximum under specific conditions. The safe continuous operating current depends on the thermal design. You must use the forward current derating curve based on your measured or estimated solder pad temperature (Ts). For example, if Ts is 100°C, the maximum allowed continuous current is significantly lower than 250mA.

Q: What is the difference between the real and electrical thermal resistance (Rth JS)?
A: The electrical method uses the LED's temperature-sensitive electrical parameters to estimate junction temperature, while the real method may use a physical sensor. The real method value (23-26 K/W) is generally considered more conservative and reliable for thermal design calculations.

Q: The datasheet mentions a Sulfur Test. Why is this important?
A: Sulfur-containing atmospheres (e.g., from certain rubbers, gaskets, or industrial environments) can corrode silver-based lead frames, leading to failure. A Sulfur Test Class A1 rating indicates the device has passed specific testing for resistance to sulfur corrosion, which is crucial for long-term reliability in enclosed automotive assemblies.

11. Practical Design Case Study

Consider designing a rear stop light module using this LED. A cluster of 10 LEDs in series would require a driver capable of providing 140mA at approximately 22V (10 * 2.2V typical), plus headroom. The PCB must be designed with thermal vias under each LED's thermal pad, connecting to a large internal ground plane for heat spreading. The derating curve must be consulted: if the PCB's temperature near the LEDs reaches 80°C in the worst-case ambient environment, the maximum permissible current per LED must be checked and potentially reduced from 140mA to ensure the junction temperature stays below 150°C. Optical simulation would be used to arrange the LEDs and design a diffuser to meet the required luminous intensity distribution and uniformity standards for automotive stop lights.

12. Operating Principle Introduction

This is a semiconductor-based light-emitting diode. When a forward voltage exceeding its characteristic forward voltage (Vf) is applied, electrons and holes recombine within the active region of the semiconductor chip, releasing energy in the form of photons (light). The specific material composition of the semiconductor (likely based on AlInGaP for red emission) determines the dominant wavelength of the emitted light. The SMD package incorporates a lead frame for electrical connection and thermal conduction, a silicone lens to protect the chip and shape the light output, and a white reflective cavity to enhance light extraction efficiency.

13. Technology Trends

The trend in automotive LED lighting continues towards higher efficiency (more lumens per watt), greater power density, and improved reliability. This allows for smaller, more energy-efficient lighting modules. There is also a focus on advanced functionalities like adaptive driving beams (ADB) and communication via light (Li-Fi), though these typically require more complex components. For standard signaling functions, the emphasis remains on cost-optimized, highly reliable, and qualified components like the one described, with ongoing improvements in thermal performance and lifetime under high-temperature operation.