LED Component Datasheet - Lifecycle Phase Revision 3 - Release Date 2013-07-05 - English Technical Document

1. Product Overview

This technical document provides the lifecycle and revision control information for a specific electronic component, likely an LED or similar semiconductor device. The core information presented is the formal declaration of the document's revision status and its release details. The "Lifecycle Phase: Revision" indicates the document is in a state of controlled updates and corrections. The "Expired Period: Forever" signifies that this particular revision of the document has no planned expiration date and is intended to be the definitive reference for this version of the product specification. The consistent release date across all entries points to a single, coordinated update event for the technical data.

The primary purpose of such a document is to ensure traceability and consistency in the manufacturing, procurement, and design processes. By locking a specific revision with a "Forever" expiry, it guarantees that all parties involved in the product lifecycle are referencing the exact same set of technical parameters and specifications, eliminating ambiguity that could arise from referencing outdated or draft documents.

2. Technical Parameters Deep Objective Interpretation

While the provided PDF excerpt focuses on document metadata, a complete datasheet for an electronic component would contain several critical technical sections. The absence of specific numerical parameters in the snippet necessitates a general explanation of what such sections typically entail.

2.1 Photometric and Electrical Characteristics

A comprehensive datasheet details the component's performance under specified conditions. For a light-emitting component, this includes Photometric Characteristics such as luminous flux (measured in lumens), dominant wavelength or correlated color temperature (CCT, measured in Kelvin), color rendering index (CRI), and viewing angle. Electrical Characteristics are equally critical, specifying the forward voltage (Vf) at a given test current, the maximum forward current, reverse voltage, and power dissipation. These parameters are essential for designing the appropriate driving circuitry and ensuring reliable operation within safe operating areas (SOA).

2.2 Thermal Characteristics

Thermal management is paramount for semiconductor reliability. The datasheet should specify the thermal resistance from the junction to the solder point or ambient air (Rth). It will also define the maximum junction temperature (Tj max). Understanding these values allows engineers to design adequate heat sinking or PCB layouts to prevent thermal runaway and ensure long-term performance and lifespan, as elevated temperatures directly degrade luminous output and accelerate failure mechanisms.

3. Binning System Explanation

Manufacturing variations are inherent in semiconductor production. A binning system categorizes components based on measured performance post-production to ensure consistency for the end-user.

3.1 Wavelength/Color Temperature Binning

Components are sorted into bins based on their precise dominant wavelength (for monochromatic LEDs) or correlated color temperature (for white LEDs). This ensures that products assembled with LEDs from the same bin have uniform color appearance, which is critical for applications like display backlighting or architectural lighting.

3.2 Luminous Flux Binning

LEDs are also binned according to their light output at a standard test current. This allows designers to select components that meet specific brightness requirements and maintain consistency across a production run.

3.3 Forward Voltage Binning

Sorting by forward voltage (Vf) helps in designing more efficient and consistent driver circuits. Grouping LEDs with similar Vf characteristics minimizes current imbalances in parallel configurations, leading to more uniform brightness and better overall system efficiency.

4. Performance Curve Analysis

Graphical data provides deeper insight into component behavior beyond single-point specifications.

4.1 Current-Voltage (I-V) Characteristic Curve

This curve plots the relationship between forward current (If) and forward voltage (Vf). It is non-linear, showing a turn-on voltage and then a region where voltage increases gradually with current. This curve is fundamental for driver design, especially for constant-current sources.

4.2 Temperature Dependency Curves

These graphs show how key parameters like forward voltage, luminous flux, and dominant wavelength shift with changes in junction temperature. Typically, Vf decreases with rising temperature, while light output also decreases. Understanding these relationships is crucial for designing systems that maintain performance across operating temperature ranges.

4.3 Spectral Power Distribution

For color-critical applications, a graph showing the relative intensity of light emitted at each wavelength is provided. For white LEDs, this shows the blue pump peak and the broader phosphor emission spectrum, defining the color quality.

5. Mechanical and Packaging Information

Precise physical specifications are necessary for PCB design and assembly.

5.1 Dimensional Outline Drawing

A detailed drawing with critical dimensions (length, width, height) and tolerances. It defines the component's footprint and profile, which must be accommodated in the mechanical design.

5.2 Pad Layout Design

The recommended PCB land pattern (pad size, shape, and spacing) is provided to ensure proper solder joint formation during reflow and reliable mechanical attachment.

5.3 Polarity Identification

The method for identifying the anode and cathode (e.g., a notch, a dot, or different lead lengths) is clearly indicated to prevent reverse mounting during assembly.

6. Soldering and Assembly Guidelines

Improper handling can damage components. These guidelines ensure assembly process compatibility.

6.1 Reflow Soldering Profile

A recommended temperature vs. time profile for reflow soldering is specified, including preheat, soak, reflow peak temperature, and cooling rates. Adhering to this profile prevents thermal shock and damage to the LED package or internal die.

6.2 Precautions and Handling

Instructions typically include warnings against applying mechanical stress, the need for electrostatic discharge (ESD) protection during handling, and avoidance of cleaning solvents that may damage the lens or encapsulant.

6.3 Storage Conditions

Recommended temperature and humidity ranges for long-term storage are provided to prevent moisture absorption (which can cause "popcorning" during reflow) and other degradation.

7. Packaging and Ordering Information

This section details how the component is supplied and how to specify it for purchase.

7.1 Packaging Specifications

Describes the tape and reel dimensions (for surface-mount devices), reel quantities, or other packaging formats like tubes or trays.

7.2 Labeling and Marking

Explains the codes printed on the component body or packaging, which often include part number, date code, and binning information.

7.3 Model Number Nomenclature

Breaks down the part number string to explain how each segment corresponds to specific attributes like color, flux bin, voltage bin, packaging type, etc., enabling accurate ordering.

8. Application Recommendations

8.1 Typical Application Circuits

Schematics for basic constant-current driver circuits, often using a simple resistor for low-power indicators or a dedicated LED driver IC for higher-power applications, may be provided.

8.2 Design Considerations

Key advice includes ensuring adequate heat sinking, avoiding operation at absolute maximum ratings for extended periods, considering thermal derating, and protecting against voltage transients or reverse polarity connection.

9. Technical Comparison

While not always in a single-datasheet, a comparative analysis might highlight advantages such as higher luminous efficacy (lumens per watt), better color uniformity, lower thermal resistance, or a more compact form factor compared to previous generations or alternative technologies, justifying its use in modern designs.

10. Frequently Asked Questions

Based on common technical queries: How does temperature affect brightness and color? What is the recommended drive current for a balance of efficiency and lifetime? Can multiple LEDs be connected in parallel directly? How should the LED be protected from ESD? What is the expected lifetime (L70/B50) under typical operating conditions?

11. Practical Use Cases

Examples include: Case 1: Backlighting Unit – Using tightly binned LEDs for uniform color and brightness across a liquid crystal display panel. Case 2: Architectural Linear Fixture – Designing with thermal parameters in mind to maintain output and color stability in an enclosed luminaire. Case 3: Automotive Signal Lamp – Selecting components that meet specific regulatory photometric requirements and can withstand harsh environmental conditions.

12. Principle Introduction

Light-emitting diodes are semiconductor devices that emit light through electroluminescence. When a forward voltage is applied across the p-n junction, electrons recombine with holes, releasing energy in the form of photons. The wavelength (color) of the light is determined by the energy bandgap of the semiconductor material. White LEDs are typically created by coating a blue or ultraviolet LED chip with a phosphor material that down-converts some of the emitted light to longer wavelengths, producing a broad spectrum perceived as white.

13. Development Trends

The field continues to advance towards higher efficiency (more lumens per watt), improved color rendering indices (CRI and R9 for red saturation), and higher reliability at elevated temperatures and currents. Miniaturization remains a trend, enabling new form factors. There is also significant development in human-centric lighting, tuning spectral content to influence circadian rhythms, and in micro-LED technology for next-generation displays. The drive for sustainability pushes for reduced use of critical materials and improved recyclability.