LED Component Technical Document - Revision 2 - Release Date 2014-12-10 - English Specification

1. Document Overview

This technical document provides essential information regarding the lifecycle status and release details of an electronic component, specifically an LED. The primary purpose is to inform users and engineers about the current revision of the product's technical specifications and its validity. The document is structured to present key administrative and technical data clearly and concisely.

The core information contained herein revolves around the document's revision control. Understanding the revision history is crucial for ensuring that the correct technical parameters are referenced during the design, procurement, and manufacturing processes. Using an outdated specification can lead to product incompatibility or performance issues.

2. Lifecycle and Release Information

The document explicitly states the lifecycle phase of the component's technical data. This section details the specific attributes related to the document's versioning and release schedule.

2.1 Lifecycle Phase

The Lifecycle Phase is identified as Revision: 2. This indicates that this document is the second major revision of the original technical specifications. A revision typically implies significant updates, corrections, or additions to the technical content, such as updated performance graphs, revised electrical parameters, new mechanical drawings, or changes in test methodologies. It is critical for users to verify they are working with the latest revision to incorporate all technical improvements and corrections.

2.2 Validity Period

The Expired Period is specified as Forever. This denotes that this particular revision of the document does not have a predefined expiration date. The technical specifications contained within are considered valid indefinitely, or until superseded by a newer revision. This is common for stable product specifications where the core technology and design are mature and not subject to frequent change. However, "Forever" should be interpreted as "until a new revision is issued," and users should periodically check for updates from the source.

2.3 Release Date

The Release Date is 2014-12-10 09:53:17.0. This timestamp provides the exact date and time when Revision 2 of this document was officially published and made available. The release date is a key piece of metadata for document control and traceability. It allows users to determine the vintage of the specifications and coordinate it with product manufacturing dates, firmware versions, or other time-sensitive design elements. A document released in 2014 suggests the component technology was finalized around that period.

3. Technical Parameters and Specifications

While the provided text snippet focuses on document metadata, a complete technical datasheet for an LED component would contain extensive technical parameters. Based on standard industry practice for LED documentation circa 2014, the following sections would be critically analyzed. The absence of specific values here necessitates a general explanation of what these parameters mean and their importance.

3.1 Photometric and Color Characteristics

This section would detail the light output and color properties of the LED. Key parameters typically include:

• Luminous Flux: The total visible light emitted by the LED, measured in lumens (lm). This is a primary indicator of brightness.
• Dominant Wavelength / Correlated Color Temperature (CCT): For colored LEDs, the dominant wavelength (in nanometers) defines the perceived color (e.g., 630nm for red). For white LEDs, the CCT (in Kelvin, e.g., 3000K, 6500K) defines whether the light is warm, neutral, or cool white.
• Color Rendering Index (CRI): For white LEDs, CRI indicates how accurately the light source reveals the true colors of objects compared to a natural light source. A higher CRI (closer to 100) is better for applications requiring accurate color perception.
• Viewing Angle: The angle at which the luminous intensity is half of the intensity at the center (e.g., 120 degrees). This defines the beam spread.

These parameters are essential for selecting the right LED for applications like general lighting, signage, backlighting, or indicators, where specific brightness, color quality, and light distribution are required.

3.2 Electrical Parameters

The electrical characteristics define how the LED must be driven. Critical parameters include:

• Forward Voltage (Vf): The voltage drop across the LED when it is emitting light at a specified current. This is crucial for designing the driver circuit (e.g., 3.2V typical).
• Forward Current (If): The recommended operating current for the LED (e.g., 20mA, 150mA, 350mA). Exceeding the maximum rated current can drastically reduce lifespan or cause immediate failure.
• Reverse Voltage (Vr): The maximum voltage the LED can withstand in the non-conducting direction without damage.
• Power Dissipation: The electrical power consumed by the LED, calculated as Vf * If, which relates to the thermal load.

Proper thermal management, often involving a heatsink, is directly linked to these electrical parameters to prevent overheating and ensure long-term reliability.

3.3 Thermal Characteristics

LED performance and lifespan are highly sensitive to temperature. Key thermal parameters are:

• Junction Temperature (Tj): The temperature at the semiconductor chip itself. The maximum allowable Tj is a critical limit.
• Thermal Resistance (Rth j-s or Rth j-a): This measures how effectively heat travels from the LED junction to the solder point (junction-to-solder) or to the ambient air (junction-to-ambient). A lower thermal resistance means better heat dissipation.
• Derating Curves: Graphs showing how the maximum allowable forward current decreases as the ambient or solder point temperature increases.

Ignoring thermal management is a leading cause of premature LED failure, including color shift, lumen depreciation, and catastrophic failure.

4. Binning and Classification System

Due to manufacturing variations, LEDs are sorted into performance bins. This system ensures consistency for the end-user.

• Flux Bin: LEDs are grouped based on their measured luminous flux output at a standard test current.
• Voltage Bin: Grouping based on forward voltage (Vf) ranges.
• Color/Wavelength Bin: For colored LEDs, bins are defined by wavelength ranges. For white LEDs, bins are defined by chromaticity coordinates on the CIE chart, often corresponding to MacAdam ellipses (e.g., 3-step, 5-step).

Understanding the binning codes is essential for applications requiring tight color or brightness matching across multiple LEDs.

5. Performance Curve Analysis

Graphical data provides deeper insight than single-point specifications.

• I-V Curve (Current vs. Voltage): Shows the relationship between forward current and forward voltage. It is non-linear, and the operating point is chosen on the steep part of the curve.
• Relative Luminous Flux vs. Forward Current: Shows how light output increases with current, typically in a linear region before efficiency drops at high currents.
• Relative Luminous Flux vs. Junction Temperature: Demonstrates the thermal quenching effect—light output decreases as temperature rises.
• Spectral Power Distribution: A graph plotting the intensity of light emitted at each wavelength. It defines the color characteristics and reveals peaks for phosphor-converted white LEDs.

6. Mechanical and Packaging Information

This section would include detailed dimensional drawings, often with top, side, and bottom views. Key elements are:

• Package Dimensions: Exact length, width, and height (e.g., 2.8mm x 3.5mm x 1.2mm for a 2835 package).
• Pad Layout (Footprint): The recommended solder pad pattern on the PCB for optimal soldering and thermal performance.
• Polarity Identification: Clear marking (e.g., a cut corner, a dot, a cathode mark) to indicate the anode and cathode for correct electrical connection.
• Lens Description: Details on the encapsulant lens material (e.g., silicone, epoxy) and shape (e.g., domed, flat).

7. Soldering and Assembly Guidelines

Proper assembly is critical for reliability. Guidelines typically cover:

• Reflow Soldering Profile: A time-temperature graph specifying the preheat, soak, reflow, and cooling phases. It includes peak temperature limits (e.g., 260°C for 10 seconds) to avoid damaging the LED package.
• Hand Soldering Instructions: If applicable, limits for iron temperature and contact time.
• Cleaning Recommendations: Guidance on using or avoiding flux cleaners.
• Storage Conditions: Recommended temperature and humidity for storing LEDs before use, often in moisture-sensitive device (MSD) bags with desiccant.

8. Application Notes and Design Considerations

This section provides practical advice for implementing the LED in a circuit.

• Driver Circuit Design: Emphasizes the need for a constant-current driver, not a constant-voltage source, to ensure stable light output and prevent thermal runaway. Discusses simple resistor-based drivers vs. active IC drivers.
• Thermal Management Design: Guidelines for PCB layout (using thermal vias, large copper areas), heatsinking, and ensuring the solder point temperature remains within specified limits.
• Optical Considerations: Advice on secondary optics (lenses, diffusers) and the impact of the LED's native viewing angle.
• ESD Precautions: Most LEDs are sensitive to electrostatic discharge (ESD). Handling and assembly should follow ESD-safe protocols.

9. Typical Application Scenarios

Based on common LED uses from the 2010s, this component could be designed for:

• General Lighting: LED bulbs, tubes, panels, and downlights for residential and commercial use.
• Backlighting: For LCD displays in televisions, monitors, and signage.
• Automotive Lighting: Interior lights, daytime running lights (DRLs), brake lights, and turn signals.
• Consumer Electronics: Status indicators, keyboard backlights, and decorative lighting in appliances.

10. Frequently Asked Questions (FAQ)

Q: What does "Revision: 2" mean for my design?
A: It means you must ensure your Bill of Materials (BOM) and all design files reference this specific revision. There may be parameter changes from Revision 1 that could affect circuit performance or compatibility.

Q: The release date is 2014. Is this product obsolete?
A: Not necessarily. "Forever" validity and a 2014 release suggest a mature, stable product that may still be in widespread production. However, you should confirm active production status with the supplier and check for any subsequent revisions or replacement products.

Q: The PDF snippet lacks technical specs. Where do I find them?
A> The provided text appears to be a header or footer from a larger document. The complete technical datasheet would contain all the sections detailed above (electrical, optical, thermal, mechanical). You would need to obtain the full document.

11. Technology Trends and Context (Circa 2014)

In 2014, the LED industry was in a period of rapid advancement in efficacy (lumens per watt) and cost reduction. Mid-power LED packages (like the 2835, 3030, 5630) were becoming dominant for general lighting, offering a good balance of performance, cost, and reliability. Phosphor-converted white LED technology was mature, with continuous improvements in CRI and color consistency. The industry was also focusing on improving reliability and lifetime predictions through better thermal management materials and designs. This document's release aligns with this era of consolidation and optimization of LED technology for mass-market lighting applications.