LED Component Datasheet - Lifecycle Revision 2 - Release Date 2014-12-05 - English Technical Document

1. Product Overview

This technical document provides comprehensive specifications and application guidelines for a light-emitting diode (LED) component. The primary function of this component is to convert electrical energy into visible light with high efficiency and reliability. It is designed for integration into a wide range of electronic systems requiring illumination, indication, or backlighting.

The core advantage of this LED lies in its stable performance and consistent quality, as indicated by its documented lifecycle phase. It is engineered for longevity and stable operation under specified conditions, making it suitable for applications where maintenance is difficult or where long-term reliability is paramount. The target market includes consumer electronics, automotive lighting, industrial indicators, and general lighting fixtures.

2. In-Depth Technical Parameter Analysis

While specific numerical values for parameters like forward voltage, luminous flux, or wavelength are not provided in the excerpt, a standard LED datasheet would detail these critical characteristics. The following sections explain the typical parameters found in such documents.

2.1 Photometric and Color Characteristics

Photometric characteristics define the light output of the LED. Key parameters include luminous flux (measured in lumens, lm), which indicates the total perceived power of light emitted. The dominant wavelength or correlated color temperature (CCT) defines the color of the light, ranging from warm white to cool white for white LEDs, or specific colors like red, green, or blue for monochromatic LEDs. Color rendering index (CRI) is crucial for white LEDs, indicating how accurately the light reveals the true colors of objects compared to a natural light source.

2.2 Electrical Parameters

Electrical parameters are vital for circuit design. The forward voltage (Vf) is the voltage drop across the LED when it is operating at its specified current. The forward current (If) is the recommended operating current, typically given as a continuous DC value. Exceeding the maximum forward current can lead to rapid degradation or catastrophic failure. Reverse voltage (Vr) specifies the maximum voltage the LED can withstand when biased in the non-conducting direction.

2.3 Thermal Characteristics

LED performance is highly dependent on junction temperature. The thermal resistance (Rth j-a) from the semiconductor junction to the ambient environment is a key figure. A lower thermal resistance indicates better heat dissipation. The maximum junction temperature (Tj max) must not be exceeded to ensure long-term reliability. Proper thermal management, often involving a heatsink, is essential to maintain light output and lifespan.

3. Binning System Explanation

Due to manufacturing variations, LEDs are sorted into bins based on key parameters to ensure consistency within a production batch.

3.1 Wavelength/Color Temperature Binning

LEDs are binned according to their dominant wavelength (for colored LEDs) or correlated color temperature (for white LEDs). This ensures that all LEDs in an assembly have a nearly identical color appearance, which is critical for applications like display backlights or architectural lighting.

3.2 Luminous Flux Binning

Luminous flux bins group LEDs based on their light output at a standard test current. This allows designers to select components that meet specific brightness requirements and ensures uniformity in multi-LED arrays.

3.3 Forward Voltage Binning

Forward voltage bins categorize LEDs based on their Vf at a specified test current. Matching Vf bins can simplify driver design, especially for LEDs connected in series, as it helps maintain uniform current distribution.

4. Performance Curve Analysis

4.1 Current-Voltage (I-V) Characteristic Curve

The I-V curve shows the relationship between the forward voltage applied and the resulting current through the LED. It is non-linear, with a sharp increase in current once the forward voltage exceeds a threshold. This curve is essential for selecting the appropriate current-limiting method (e.g., resistor or constant-current driver).

4.2 Temperature Dependency

Graphs typically show how luminous flux and forward voltage change with increasing junction temperature. Luminous flux generally decreases as temperature rises, a phenomenon known as thermal droop. Forward voltage also decreases slightly with increasing temperature. Understanding these relationships is critical for designing systems that operate in varying thermal environments.

4.3 Spectral Power Distribution

For white LEDs, the spectral power distribution (SPD) graph shows the intensity of light emitted at each wavelength across the visible spectrum. It reveals the peaks of the blue pump LED and the broad emission of the phosphor. The SPD determines the color quality metrics like CRI and CCT.

5. Mechanical and Package Information

The physical package protects the semiconductor die and provides electrical connections and a path for heat dissipation.

5.1 Dimensional Outline Drawing

A detailed mechanical drawing specifies the package's exact length, width, height, and tolerances. It includes critical dimensions for PCB footprint design, such as pad spacing and component clearance.

5.2 Pad Layout and Solder Pad Design

The recommended PCB land pattern (footprint) is provided, showing the size, shape, and spacing of the copper pads. Adhering to this design ensures proper solder joint formation during reflow and reliable mechanical attachment.

5.3 Polarity Identification

The method for identifying the anode (+) and cathode (-) terminals is clearly indicated, usually via a marking on the package (e.g., a notch, a dot, a green line, or a shorter lead). Correct polarity is essential for operation.

6. Soldering and Assembly Guidelines

6.1 Reflow Soldering Profile

A recommended reflow temperature profile is provided, including preheat, soak, reflow peak temperature, and cooling rates. The peak temperature and time above liquidus (TAL) must be strictly controlled to prevent damage to the LED package or the internal wire bonds.

6.2 Precautions and Handling

LEDs are sensitive to electrostatic discharge (ESD). Handling should be performed at ESD-protected workstations using grounded equipment. Avoid mechanical stress on the lens. Do not clean with solvents that may damage the epoxy lens.

6.3 Storage Conditions

LEDs should be stored in a dry, cool environment, typically within a specified temperature and humidity range (e.g., <30°C, <60% RH). They are often shipped in moisture-sensitive bags with desiccants, and may require baking before use if the bag has been opened for an extended period.

7. Packaging and Ordering Information

7.1 Packaging Specifications

The component is supplied on tape and reel for automated assembly. The reel dimensions, tape width, pocket size, and component orientation on the tape are specified according to industry standards (e.g., EIA-481).

7.2 Label Information

The reel label contains critical information: part number, quantity, lot/batch number, date code, and binning codes for luminous flux, color, and voltage.

7.3 Part Numbering System

The part number is a code that uniquely identifies the product. It typically encodes key attributes such as package size, color, luminous flux bin, color temperature bin, and forward voltage bin. Understanding this nomenclature is essential for correct ordering.

8. Application Recommendations

8.1 Typical Application Circuits

Common drive circuits include simple series resistors for low-power applications and constant-current drivers for higher-power or precision applications. Diagrams and calculations for selecting the current-limiting resistor based on supply voltage and desired LED current are often provided.

8.2 Design Considerations

Key design factors include thermal management (PCB copper area, heatsinks), optical design (lenses, diffusers), and electrical design (driver compatibility, dimming method, protection against transients and reverse polarity).

9. Technical Comparison and Differentiation

Compared to older LED technologies or alternative light sources, this component likely offers advantages in efficiency (lumens per watt), longevity, physical size, and robustness. Its specific differentiation could be in a particular aspect like a very high CRI for color-critical applications, a low thermal resistance package for high-power operation, or a unique form factor for space-constrained designs.

10. Frequently Asked Questions (FAQ)

Q: What does "LifecyclePhase: Revision 2" indicate?
A: It signifies that this is the second revision of the product's technical documentation. Revisions can include updates to specifications, test methods, recommended applications, or reliability data based on ongoing product characterization and feedback.

Q: What is the implication of "Expired Period: Forever"?
A: This typically means the document has no set expiration date and is considered valid until superseded by a newer revision. The technical data remains the authoritative reference for this specific product revision.

Q: How should I interpret the release date?
A: The release date (2014-12-05) indicates when this specific revision of the datasheet was officially published. It is important to use the latest revision to ensure design accuracy.

Q: Can I drive this LED directly from a voltage source?
A: No. LEDs are current-driven devices. Connecting them directly to a voltage source without a current-limiting mechanism will typically result in excessive current, overheating, and failure. Always use a series resistor or a constant-current driver.

11. Practical Application Case Studies

Case Study 1: Backlight Unit for an LCD Display
An array of these white LEDs is used to provide uniform backlighting. Key design challenges included achieving consistent brightness and color temperature across the entire panel, which was addressed by using LEDs from tight luminous flux and CCT bins. Thermal management was solved by designing the metal chassis of the display to act as a heatsink.

Case Study 2: Automotive Interior Lighting
The LED is used for map reading lights. The design prioritized a specific warm white color temperature for user comfort. Reliability under wide temperature fluctuations and resistance to vibration were critical, met by the component's robust package and stable performance over temperature.

12. Operating Principle Introduction

An LED is a semiconductor p-n junction diode. When a forward voltage is applied, electrons from the n-type region and holes from the p-type region are injected into the junction region. When these charge carriers recombine, energy is released in the form of photons (light). The wavelength (color) of the emitted light is determined by the energy bandgap of the semiconductor material used (e.g., InGaN for blue/green, AlInGaP for red/amber). White LEDs are typically created by coating a blue LED chip with a yellow phosphor; the combination of blue and yellow light appears white to the human eye.

13. Technology Trends and Developments

The LED industry continues to evolve. Key trends include increasing luminous efficacy (more lumens per watt), improving color quality (higher CRI and more precise color rendering), and reducing cost. Miniaturization is another trend, enabling new applications in ultra-thin devices. There is also significant development in smart lighting, integrating sensors and communication capabilities directly with LED modules. Furthermore, research into new materials, such as perovskites for LEDs, aims to achieve even higher efficiencies and novel emission properties. The drive towards sustainability and energy efficiency globally continues to be a major catalyst for LED adoption and innovation.