LED Component Lifecycle Specification - Revision 1 - Release Date 2013-08-15 - English Technical Document

1. Product Overview

This technical document provides comprehensive information regarding the lifecycle status and revision control for a specific electronic component, likely an LED or related semiconductor device. The core focus is on establishing the official revision baseline and its associated metadata. The document serves as a formal record for engineering, manufacturing, and quality assurance processes, ensuring all stakeholders reference the correct and current version of the component specifications.

The primary advantage of this documented lifecycle phase is traceability and version control. By clearly stating the revision number and release date, it prevents the use of outdated or incorrect technical data in design and production. This is crucial for maintaining product consistency, reliability, and compliance with internal or industry standards. The target market includes electronics manufacturers, design engineers, procurement specialists, and quality control personnel who require definitive information on component revisions.

2. Lifecycle and Revision Information

The document repeatedly and consistently specifies a single, critical set of metadata. This repetition underscores the importance of this information and may indicate it is a standard header or footer for each page or section of a larger datasheet.

2.1 Lifecycle Phase

The lifecycle phase is explicitly stated as "Revision." This indicates that the component or its documentation is not in an initial design (Prototype) or obsolete (End-of-Life) phase. The "Revision" phase signifies an active, production-ready component where the specifications have been reviewed, potentially updated from a previous version, and formally released for use. This status implies stability and suitability for incorporation into new designs.

2.2 Revision Number

The revision number is specified as "1." This is a fundamental identifier. Revision 1 typically represents the first formally released and controlled version of the document or component specifications after initial development and validation. It establishes the baseline against which all future changes (Revision 2, 3, etc.) will be measured. Engineers must verify they are using Revision 1 to ensure their designs align with the intended performance parameters.

2.3 Expiration Period

The expiration period is listed as "Forever." This is a significant declaration. It means that this specific revision of the document or the component's qualification under this revision has no predetermined end date for its validity. It does not imply the component will be manufactured forever, but rather that the technical data contained in Revision 1 remains the authoritative reference indefinitely, unless superseded by a new revision. This provides long-term stability for designs locked to this revision.

2.4 Release Date and Time

The release date and time are precisely recorded as "2013-08-15 09:41:20.0." This timestamp provides exact traceability. It marks the moment this revision was officially issued and became effective. This information is critical for auditing, change management, and resolving any discrepancies that might arise regarding when a particular specification came into force. The inclusion of the time to the second emphasizes the formal control process.

3. Technical Parameters and Performance Characteristics

While the provided text snippet focuses on administrative metadata, a complete technical datasheet for an LED component would contain extensive objective technical parameters. The following sections detail the typical content that would accompany such lifecycle information, based on standard industry practices for LED documentation.

3.1 Photometric and Color Characteristics

A detailed datasheet would include precise photometric measurements. This encompasses luminous flux (measured in lumens), which defines the total visible light output. The correlated color temperature (CCT) would be specified for white LEDs, typically in Kelvin (e.g., 2700K Warm White, 6500K Cool White). For colored LEDs, the dominant wavelength and color purity are key parameters. Chromaticity coordinates (e.g., CIE x, y) provide the exact color point on the standard color space diagram. Furthermore, parameters like Color Rendering Index (CRI) for white LEDs, which indicates how naturally colors appear under the light source, would be included. Viewing angle, which describes the angular distribution of light intensity (e.g., 120 degrees), is also a standard specification.

3.2 Electrical Parameters

Electrical specifications are fundamental for circuit design. The forward voltage (Vf) is crucial, typically specified at a given test current (e.g., 3.2V at 60mA). This parameter has tolerances and can vary with temperature and batch. The reverse voltage rating (Vr) indicates the maximum voltage the LED can withstand when reverse-biased without damage. The absolute maximum ratings for forward current (If) and pulsed forward current are defined to prevent device failure. Additionally, electrostatic discharge (ESD) sensitivity, often classified per the Human Body Model (HBM), is a critical reliability parameter.

3.3 Thermal Characteristics

LED performance and longevity are heavily dependent on thermal management. Key thermal parameters include the thermal resistance from the junction to the solder point or ambient air (Rth j-s or Rth j-a), expressed in degrees Celsius per watt (°C/W). This value dictates how effectively heat is conducted away from the light-emitting semiconductor junction. The maximum junction temperature (Tj max) is the highest temperature the LED chip can tolerate before performance degrades or failure occurs. The relationship between forward voltage, luminous flux, and color shift as a function of junction temperature is also a critical area of analysis for robust design.

4. Binning and Classification System

Due to manufacturing variations, LEDs are sorted into performance bins. The datasheet would define the binning structure.

4.1 Wavelength or Color Temperature Binning

LEDs are binned according to their chromaticity coordinates or dominant wavelength. For white LEDs, this involves grouping units into specific CCT ranges (e.g., 3000K ± 150K). For monochromatic LEDs, bins are defined by wavelength ranges (e.g., 525nm to 535nm). This ensures color consistency within a production batch.

4.2 Luminous Flux Binning

Flux bins group LEDs based on their light output at a standard test current. A bin code (e.g., FL1, FL2, FL3) corresponds to a minimum and maximum luminous flux range. Designers select a bin to achieve the required brightness level in their application.

4.3 Forward Voltage Binning

Voltage bins categorize LEDs by their forward voltage drop. This is important for power supply design, especially in series-connected strings, to ensure uniform current distribution and prevent over-driving individual LEDs.

5. Performance Curve Analysis

Graphical data provides deeper insight into device behavior under varying conditions.

5.1 Current vs. Voltage (I-V) Characteristic Curve

This curve shows the relationship between the forward current through the LED and the voltage across its terminals. It is non-linear, exhibiting a turn-on voltage threshold. The curve helps designers select appropriate driving circuitry (constant current vs. constant voltage) and understand power dissipation.

5.2 Temperature Dependency Curves

These graphs illustrate how key parameters change with junction temperature. Typically, they show the relative luminous flux decreasing as temperature increases, and the forward voltage decreasing with rising temperature. Understanding these relationships is essential for thermal design to maintain performance.

5.3 Spectral Power Distribution (SPD)

The SPD graph plots the relative intensity of light emitted at each wavelength. For white LEDs, it shows the blue pump peak and the broader phosphor-converted spectrum. This graph is used to calculate CCT, CRI, and understand the color quality of the light.

6. Mechanical and Package Information

Physical specifications ensure proper PCB layout and assembly.

6.1 Package Dimensions and Outline Drawing

A detailed mechanical drawing provides all critical dimensions: length, width, height, lead spacing, and tolerances. This is essential for creating the PCB footprint and ensuring clearance.

6.2 Pad Layout and Solder Pad Design

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

6.3 Polarity Identification

The method for identifying the anode and cathode is clearly indicated, usually via a marking on the package (e.g., a notch, dot, or cut corner) or asymmetric lead shapes.

7. Soldering and Assembly Guidelines

7.1 Reflow Soldering Profile

A recommended reflow temperature profile is provided, including preheat, soak, reflow peak temperature (typically not exceeding 260°C for a specified time), and cooling rates. Adhering to this profile prevents thermal damage to the LED package and internal die.

7.2 Handling and Storage Precautions

Instructions include handling to avoid mechanical stress on the leads, protection from moisture (MSL rating), and storage in dry, anti-static conditions to preserve solderability and prevent ESD damage.

8. Application Notes and Design Considerations

8.1 Typical Application Circuits

Schematics for basic driving circuits are often included, such as a simple series resistor circuit for low-power applications or constant current driver circuits for optimal performance and stability.

8.2 Thermal Management Design

Guidance is given on PCB design for heat sinking, such as using thermal vias, adequate copper area under the LED pad, and possibly attaching to a metal-core PCB or external heatsink for high-power applications.

8.3 Optical Design Considerations

Notes on the use of secondary optics (lenses, diffusers) and the impact of the LED's viewing angle on the final light distribution pattern in the application.

9. Reliability and Lifetime

While not in the snippet, a full datasheet discusses reliability. This includes lumen maintenance data, often presented as L70 or L50 curves (time until light output degrades to 70% or 50% of initial). Lifetime is usually quoted under specific operating conditions (current, temperature). Failure rate predictions or reliability test results may also be included.

10. Revision History and Change Control

The provided text IS the core of the revision history for this document. It establishes Revision 1. A full datasheet would have a table summarizing all revisions: revision number, release date, and a brief description of the changes made (e.g., "Updated absolute maximum ratings," "Added new flux bin," "Corrected typo in dimension drawing"). This traceability is vital for engineers to understand what has changed between versions they may be using.

11. Principle of Operation

Light Emitting Diodes (LEDs) are semiconductor devices that emit light through electroluminescence. When a forward voltage is applied across the p-n junction, electrons from the n-type material recombine with holes from the p-type material in the active region. This recombination process releases energy in the form of photons (light). The wavelength (color) of the emitted light is determined by the energy bandgap of the semiconductor materials used (e.g., InGaN for blue/green, AlInGaP for red/amber). White LEDs are typically created by coating a blue LED chip with a phosphor material that converts some of the blue light into longer wavelengths (yellow, red), resulting in a broad spectrum perceived as white light.

12. Industry Trends and Developments

The LED industry is characterized by continuous advancement. Key trends include increases in luminous efficacy (lumens per watt), leading to more energy-efficient lighting solutions. There is a strong focus on improving color quality metrics like CRI and R9 (saturated red rendering) for high-end lighting. Miniaturization continues, enabling denser pixel pitches in displays. The development of Micro-LED and Mini-LED technologies promises new applications in ultra-high-resolution displays and direct-view lighting. Furthermore, smart and connected lighting, integrating sensors and IoT capabilities, is expanding the functional role of LEDs beyond simple illumination. The industry also emphasizes sustainability through longer lifetimes, reduced material use, and recyclability.