LED Device Specification - Revision 2 - Lifecycle Information - Chinese Technical Documentation

1. Product Overview

This technical specification provides comprehensive information for the LED device, focusing on its lifecycle management and revision history. The document structure is designed to offer engineers and procurement specialists clear insight into the product's status, ensuring compatible and informed decisions when integrating it into new designs or maintaining existing production lines. The core information presented indicates the product is in a stable "Revision 2" phase, signifying its maturity and established performance characteristics.

The core advantage of this device lies in its documented and controlled lifecycle. A "Permanent" validity period implies long-term supply and support, which is crucial for applications with long lifecycle requirements such as industrial, automotive, or infrastructure. This stability reduces the risk of product obsolescence and simplifies supply chain planning. The target markets include applications requiring reliable, long-lasting lighting solutions, where consistent performance and device availability are paramount.

2. In-depth Technical Parameter Analysis

Although the provided PDF fragment focuses on management data, a complete LED technical specification typically includes the following parameter categories, which are crucial for design selection.

2.1 Photometric and Color Characteristics

Key parameters include dominant wavelength or correlated color temperature (CCT), which define the color of the emitted light (e.g., cool white, warm white, specific monochromatic light). Luminous flux, measured in lumens (lm), represents the perceived total light output. Chromaticity coordinates (e.g., CIE x, y) provide the precise color point on the chromaticity diagram. The Color Rendering Index (CRI) is crucial for applications requiring high color accuracy, indicating how naturally colors appear under LED light compared to a reference light source.

2.2 Electrical Parameters

Forward voltage (Vf) is a key parameter that specifies the voltage drop across an LED at a specific test current. This is crucial for designing drive circuits. The forward current (If) rating defines the maximum continuous current an LED can withstand, directly affecting light output and lifetime. Reverse voltage (Vr) specifies the maximum reverse voltage that can be applied without damaging the device. Electrostatic discharge (ESD) sensitivity, typically classified according to JEDEC or MIL-STD standards, indicates the device's robustness against static electricity.

2.3 Thermal Characteristics

LED performance and lifetime depend heavily on thermal management. The junction-to-ambient thermal resistance (RθJA) quantifies the efficiency of heat transfer from the LED semiconductor junction to the surrounding environment. A lower value indicates better heat dissipation. The maximum junction temperature (Tj max) is the highest temperature the semiconductor material can withstand without permanent degradation or failure. Maintaining the LED operating temperature below this limit through adequate heat sinking is critical to achieving the rated lifetime (typically defined as L70 or L50, the time for luminous flux output to decay to 70% or 50% of its initial value).

3. Detailed Explanation of the Grading System

Variations in the manufacturing process necessitate a binning system to group LEDs with similar characteristics.

3.1 Wavelength/Color Temperature Grading

LEDs are sorted into different bins based on their precise wavelength (for monochromatic LEDs) or correlated color temperature (for white LEDs). This ensures color consistency within a single batch and across different batches. Designers must specify the required bin or acceptable bin range to maintain uniform color appearance in their application.

3.2 Luminous Flux Binning

LEDs are also binned according to their light output at standard test current. This allows designers to select devices that meet specific brightness requirements and accurately predict the final light output of their assemblies.

3.3 Forward Voltage Binning

Grouping LEDs by forward voltage (Vf) helps design more efficient and consistent drive circuits. Using LEDs from the same Vf bin can improve current matching in parallel arrays and make power consumption more predictable.

4. Performance Curve Analysis

Graphical data is crucial for understanding device behavior under various conditions.

4.1 Current-Voltage (I-V) Characteristic Curve

This curve shows the relationship between the forward current through an LED and the voltage across its terminals. It is nonlinear, exhibiting a turn-on voltage threshold. This curve is essential for selecting appropriate current-limiting components or designing constant-current drivers.

4.2 Temperature Characteristics

Graphs typically show how forward voltage and luminous flux vary with junction temperature. Forward voltage generally decreases as temperature increases, while luminous flux decays. Understanding these relationships is key to thermal design and predicting performance in real-world operating environments.

4.3 Spectral Power Distribution

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

5. Mechanical and Packaging Information

PCB layout and assembly require precise physical dimensions.

5.1 Outline Dimensions Drawing

Detailed drawings including top, side, and bottom views, with all critical dimensions (length, width, height, lens shape) and tolerances. This ensures the device fits the designed footprint on the printed circuit board (PCB).

5.2 Pad Layout Design

Provides recommended PCB pad patterns (pad size, shape, and spacing) to ensure reliable solder joint formation during the reflow process and to provide adequate thermal and electrical connection.

5.3 Polarity Marking

Clear markings indicate the anode and cathode. This is typically shown via notches, dots, bevels, or different lead lengths. Correct polarity is crucial for the proper operation of the device.

6. Welding and Assembly Guide

6.1 Reflow Soldering Temperature Profile

Provides the recommended reflow soldering time-temperature profile, including preheating, soaking, reflow, and cooling stages. Specifies the maximum peak temperature and time above liquidus to prevent thermal damage to the LED package (especially the silicone lens and internal bonding).

6.2 Precautions and operating specifications

The guidelines include avoiding mechanical stress on the lens, preventing contamination of optical surfaces, and implementing appropriate ESD protection measures during handling. Recommendations for cleaning agents compatible with LED materials may also be included.

6.3 Storage Conditions

Specifies the ideal storage temperature and humidity range to maintain solderability and prevent moisture absorption. If the device is not properly baked before use, moisture absorption may cause the "popcorn" phenomenon during reflow soldering.

7. Packaging and Ordering Information

7.1 Packaging Specifications

Details the LED supply method: reel type (e.g., tape width, pocket size), number of reels, and device orientation within the reel (for automatic placement machines).

7.2 Label Information

Explains the information printed on the reel label, including part number, quantity, date code, lot number, and binning codes for luminous flux, color, and voltage.

7.3 Model Naming Rules

Parsed the structure of the part number, showing how different codes within the number represent specific attributes, such as color, luminous flux bin, voltage bin, package type, and special functions.

8. Application Suggestions

8.1 Typical Application Scenarios

Based on its technical parameters, this LED is suitable for general lighting (bulbs, tubes, panels), architectural lighting, signage, display backlighting, automotive lighting (interior, signal lights), and industrial lighting. The "permanent" lifetime indicates its suitability for applications with long service life expectations.

8.2 Key Design Considerations

Key considerations include: employing constant current drivers for stable operation; designing effective thermal paths to manage junction temperature; ensuring optical design (lenses, reflectors) matches the LED's viewing angle and luminous intensity distribution; and protecting the LED from electrical transients and reverse voltage.

9. Technical Comparison

While a direct comparison requires specific competitor devices, the advantages of devices with a clear "Revision 2" and "Permanent" lifecycle status include: reduced risk of premature obsolescence, reliability verification from mature designs, and potentially better supply and cost stability compared to newly introduced or discontinued devices. Technical parameters (when fully specified) will be compared against alternatives in terms of efficiency (lm/W), color quality (CRI, CCT consistency), reliability (lifetime rating), and package size.

10. Frequently Asked Questions (FAQ)

Q: What does "Lifecycle Stage: Revision 2" mean?
A: This indicates the product is in the mature stage of its lifecycle. The design is finalized and has entered mass production. "Revision 2" implies at least one prior version exists, and this version incorporates improvements or fixes.

Q: What does "Validity: Permanent" mean?
A: This typically means the manufacturer currently has no planned End-of-Life (EOL) date for this product. It is intended for long-term supply, which is beneficial for designs requiring a stable supply chain for many years.

Q: How should I interpret the Release Date?
A: The release date (2014-12-05) marks the official publication time of this specific revision of the specification or product. It helps track document versions and can be used to ensure designs are using the latest specifications.

Q: Can I mix LEDs of different bins in my product?
A: It is generally not recommended to mix bins, especially for color and luminous flux bins, as this can lead to visible color and brightness differences in the final product. For consistent performance, use LEDs from the same or adjacent bins.

11. Practical Application Cases

Scenario: Designing a Linear LED Luminaire for Office Lighting
A design engineer is designing a 4-foot LED troffer for an office ceiling. Using this datasheet, they will:
1. Select the appropriate luminous flux gear to achieve the target lumen value for each luminaire.
2. Select a specific CCT gear (e.g., 4000K) to meet office lighting standards.
3. Utilize the Vf gear and I-V curve to design the series-parallel array and specify the constant current driver.
4. Refer to the thermal resistance (RθJA) and derating curve to design an aluminum heat sink, keeping the junction temperature below Tj max to ensure the 50,000-hour L70 lifetime claim is met.
5. Use the mechanical drawing to create the PCB footprint dimensions and ensure proper spacing between LEDs on the Metal Core PCB (MCPCB).
6. Follow the reflow soldering temperature profile during SMT assembly to avoid damaging components.

12. Brief Introduction to Working Principles

A Light Emitting Diode (LED) is a semiconductor device that emits light through electroluminescence. When a forward voltage is applied across the p-n junction, electrons from the n-type region recombine with holes from the p-type region, releasing energy in the form of photons. The wavelength (color) of the emitted light is determined by the bandgap energy of the semiconductor material used (e.g., InGaN for blue/green light, AlInGaP for red/amber light). White LEDs are typically created by coating a blue or ultraviolet LED chip with phosphor materials. Part of the blue light is converted by the phosphor to longer wavelengths (yellow, red light), and the mixture of blue light and phosphor-converted light is perceived as white light.

13. Technology Development Trends

The LED industry continues to evolve, showing several key trends. Efficiency (lumens per watt) is steadily increasing, reducing energy consumption for the same light output. Color quality is constantly improving, with high-CRI LEDs becoming more common and affordable. Miniaturization continues, enabling new form factors for displays and lighting. There is growing focus on horticultural lighting, with spectra customized for plant growth. Smart lighting integrating built-in drivers and controls is expanding. Furthermore, reliability and lifetime predictions are becoming more accurate through advanced testing and modeling, supporting long-life claims as demonstrated in this document.