LED Component Technical Datasheet - Peak Wavelength Analysis - Electrostatic Bag and Carton Packaging Details - English Technical Document

1. Product Overview

This technical document provides comprehensive specifications for a light-emitting diode (LED) component. The primary focus is on the device's key optical parameter, the peak wavelength, and detailed packaging requirements to ensure proper handling and storage. The document is structured to serve engineers, procurement specialists, and quality assurance personnel involved in the integration of this component into electronic assemblies. The information is presented in a revision-controlled format, ensuring users reference the most current technical data.

2. Document Control and Lifecycle Information

The document is identified as Revision 4, indicating it is the fourth official version. The release date for this revision is recorded as June 10, 2013, at 16:24:33. The lifecycle phase is clearly marked as "Revision," and the expired period is noted as "Forever," signifying that this document version remains valid indefinitely unless superseded by a newer revision. This control information is critical for maintaining traceability and ensuring that all stakeholders are working from the same, approved set of specifications.

3. Technical Parameter Deep Dive

3.1 Photometric and Optical Characteristics

The core optical parameter specified in this document is the peak wavelength (λp). The peak wavelength is the specific wavelength at which the LED emits its maximum optical power. This parameter is fundamental in defining the perceived color of the LED. For instance, a peak wavelength around 450-470 nm typically corresponds to blue light, 520-550 nm to green, and 620-660 nm to red. The exact value of λp is a critical design factor for applications requiring specific color points, such as display backlighting, signage, or ambient lighting. The tolerance or binning associated with this peak wavelength, while not explicitly detailed in the provided excerpt, is a standard specification that would define the allowable variation from the nominal λp value, ensuring color consistency across production batches.

Other related optical parameters, such as luminous intensity, viewing angle, and spectral half-width, are essential for a complete performance profile but are not listed in the provided content. Designers must consider the peak wavelength in conjunction with the LED's driving current and junction temperature, as these factors can cause a shift in the emitted wavelength.

4. Packaging and Handling Specifications

4.1 Packaging Hierarchy and Materials

The packaging system for this LED component is designed to provide multiple layers of protection against electrostatic discharge (ESD), mechanical damage, and environmental contamination. The specified packaging levels are:

• Electrostatic Bag: The primary container for individual LED components or reels. This bag is made from a static-dissipative or conductive material that shields the sensitive semiconductor die inside the LED from electrostatic charges that could cause latent or catastrophic failure. Proper handling requires grounding oneself and the workstation before opening the bag.
• Inner Carton: This carton holds multiple electrostatic bags, providing structural rigidity and additional protection against physical shock and compression during handling and intra-factory logistics.
• Outside Carton: The outermost shipping container. It is designed to withstand the rigors of transportation, including stacking, vibration, and potential impacts. It protects the inner packages from moisture and dust.

4.2 Packing Quantity

The document explicitly mentions "Packing Quantity" as a key specification. This refers to the number of LED units contained within one electrostatic bag. This quantity is crucial for inventory management, production planning (e.g., setting up pick-and-place machines), and cost calculation. Common packing quantities include reels (e.g., 1000, 2000, 4000 pieces per reel) or trays/ammo packs for larger devices. The specific quantity must be confirmed from the full datasheet or packing list.

5. Soldering and Assembly Guidelines

While specific soldering profiles are not detailed in the provided text, standard Surface-Mount Device (SMD) LED assembly practices apply. These components are typically assembled using reflow soldering. The recommended profile includes a preheat stage to gradually raise the temperature and activate the flux, a soak zone to ensure uniform heating across the board, a peak reflow temperature where the solder paste melts and forms the joint, and a controlled cooling phase. The maximum peak temperature and the time above liquidus (TAL) must be within the LED's specified limits to prevent damage to the plastic lens, the semiconductor die, or the internal wire bonds. The use of an electrostatic bag prior to assembly underscores the necessity of ESD-safe practices throughout the handling and soldering process.

6. Storage and Shelf Life

Proper storage conditions are implied by the emphasis on electrostatic packaging. LEDs should be stored in their original, unopened electrostatic bags in a controlled environment. Recommended conditions typically include a temperature range of 5°C to 30°C and a relative humidity below 60% to prevent moisture absorption, which can lead to "popcorning" (package cracking) during reflow soldering. The bags should be kept away from direct sunlight and sources of ozone or other corrosive gases. Once the moisture barrier bag is opened, components should be used within a specified timeframe (e.g., 168 hours at factory floor conditions) or be re-baked according to the manufacturer's instructions to remove absorbed moisture.

7. Application Suggestions and Design Considerations

The primary application for an LED characterized by its peak wavelength is in illumination and indication. Designers must select the λp based on the desired color output. Key design considerations include:

• Drive Current: Operating the LED at or below its rated current is essential for longevity and stable color output. Exceeding the current rating can cause excessive heat, wavelength shift, and accelerated lumen depreciation.
• Thermal Management: LEDs generate heat at the junction. An effective thermal path, often via the printed circuit board (PCB) to a heatsink, is necessary to maintain a low junction temperature. High junction temperatures reduce light output efficiency and can permanently shift the peak wavelength.
• Optical Design: The lens or secondary optics used with the LED must be compatible with its emission pattern and wavelength to achieve the desired beam angle and optical efficiency.

8. Performance Curves and Characteristics Analysis

Although not present in the excerpt, a complete datasheet would include several key performance graphs for thorough analysis:

• Relative Luminous Intensity vs. Forward Current (I_F): This curve shows how light output increases with drive current, typically in a sub-linear fashion, highlighting the point of diminishing returns and potential overheating.
• Forward Voltage vs. Forward Current (I-V Curve): Essential for designing the driving circuit (e.g., choosing a current-limiting resistor or constant-current driver).
• Peak Wavelength vs. Junction Temperature: This graph quantifies the shift in λp as the LED heats up, which is critical for color-critical applications.
• Spectral Power Distribution: A plot showing the relative intensity of light emitted at each wavelength, providing a full picture beyond just the peak wavelength, including the spectral half-width.

9. Binning System Explanation

LED manufacturing yields natural variations in key parameters. A binning system categorizes LEDs into groups (bins) based on these parameters to ensure consistency. The primary bins typically relate to:

• Wavelength/Color Temperature Bin: Groups LEDs by their peak wavelength (for monochromatic LEDs) or correlated color temperature (CCT) and chromaticity coordinates (for white LEDs). This ensures a uniform color appearance when multiple LEDs are used together.
• Luminous Flux Bin: Groups LEDs by their total light output at a specified test current. This allows designers to select bins that meet specific brightness requirements.
• Forward Voltage Bin: Groups LEDs by the voltage drop across them at a specified test current. This can simplify power supply design and improve current matching in parallel arrays.

10. Mechanical and Package Information

The mechanical drawing, which is not included in the provided text, is a vital part of the datasheet. It would provide precise dimensions for the LED package, including length, width, height, and the size and position of the solder pads (land pattern). This drawing ensures the PCB footprint is designed correctly for reliable soldering and proper alignment. The polarity marking (typically a cathode mark, such as a notch, dot, or shortened lead) would also be clearly indicated to prevent reverse mounting during assembly.

11. Ordering Information and Model Numbering

The full datasheet would include a model number breakdown or ordering code that allows users to specify the exact variant they require. This code typically encodes key attributes such as the package type, color (peak wavelength), luminous flux bin, forward voltage bin, and sometimes packing quantity. Understanding this coding system is essential for accurate procurement.

12. Frequently Asked Questions (FAQ)

Q: Why is the peak wavelength so important?
A: The peak wavelength directly determines the dominant color of the light emitted. For applications requiring a specific color, such as traffic signals or color-mixed lighting systems, precise control of λp is non-negotiable.

Q: What is the purpose of the electrostatic bag?
A: LEDs contain sensitive semiconductor junctions that can be permanently damaged by static electricity discharges that are imperceptible to humans. The electrostatic bag provides a Faraday cage, shielding the components from external ESD events during storage and transport.

Q: How should I handle LEDs after opening the electrostatic bag?
A: Always work at an ESD-protected workstation with a grounded mat and wrist strap. Use grounded tools. If the components are not used immediately, they should be stored in a sealed, static-shielding container. For moisture-sensitive packages, adhere to the floor life after the bag is opened or follow baking procedures if exceeded.

13. Operational Principles

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 specific wavelength (color) of this light is determined by the bandgap energy of the semiconductor materials used in the active region (e.g., Indium Gallium Nitride for blue/green, Aluminum Gallium Indium Phosphide for red/amber). The peak wavelength (λp) corresponds to the most probable photon energy emitted from this recombination process.

14. Technology Trends

The LED industry continues to evolve with several key trends. Efficiency, measured in lumens per watt (lm/W), is constantly improving, reducing energy consumption for the same light output. There is a strong focus on improving color rendering index (CRI) and color consistency (reducing bin spread) for high-quality white lighting. Miniaturization of packages continues, enabling higher pixel density in direct-view displays. Furthermore, the integration of intelligent features, such as built-in drivers or color-tuning capabilities, is becoming more common. The emphasis on robust, ESD-protective, and moisture-resistant packaging, as indicated in this document, remains a fundamental requirement to ensure reliability in automated, high-volume manufacturing environments.