LED Component Datasheet - Lifecycle Revision 2 - Technical Documentation

1. Product Overview

This technical document provides comprehensive specifications and guidelines for a light-emitting diode (LED) component. The primary focus of this revision is to document the formal lifecycle phase and update the technical parameters to reflect the current manufacturing standards and performance characteristics. LEDs are semiconductor devices that convert electrical energy into visible light, widely used in applications ranging from indicator lights and backlighting to general illumination and automotive lighting due to their efficiency, longevity, and reliability.

The core advantage of this component lies in its standardized design, ensuring consistent performance across high-volume production runs. It is engineered for compatibility with automated surface-mount technology (SMT) assembly processes, making it suitable for integration into modern electronic products. The target market includes consumer electronics, industrial control systems, automotive interiors, and signage applications where reliable, low-power illumination is required.

2. Technical Parameters Deep Objective Interpretation

While the provided PDF snippet is limited, a detailed technical datasheet for an LED component typically contains the following critical parameter sections. The values below represent industry-standard ranges for a common mid-power SMD LED package; specific values would be defined in the full datasheet.

2.1 Photometric and Color Characteristics

The photometric properties define the light output and quality. Key parameters include:

• Luminous Flux (Φ_v): The total visible light emitted by the source, measured in lumens (lm). Typical values for a standard component can range from 20 lm to 120 lm depending on the color and drive current.
• Dominant Wavelength (λ_D): The perceived color of the light, measured in nanometers (nm). For white LEDs, this is replaced by Correlated Color Temperature (CCT).
• Correlated Color Temperature (CCT): For white LEDs, this describes the color appearance of the light, from warm white (e.g., 2700K-3000K) to cool white (e.g., 5000K-6500K).
• Color Rendering Index (CRI): A measure of how accurately the light source reveals the colors of objects compared to a natural light source. General lighting applications typically require a CRI of 80 or higher.

2.2 Electrical Parameters

Electrical parameters are crucial for circuit design and ensuring reliable operation.

• Forward Voltage (V_F): The voltage drop across the LED when it is emitting light at a specified forward current. It varies with color and semiconductor material (e.g., ~2.0V for red, ~3.2V for blue/white). A typical range is 2.8V to 3.4V for a white LED.
• Forward Current (I_F): The recommended operating current, typically 20mA, 60mA, or 150mA for different package sizes. Exceeding the maximum rated current can cause permanent damage.
• Reverse Voltage (V_R): The maximum voltage that can be applied in the reverse direction without damaging the LED, typically around 5V.

2.3 Thermal Characteristics

LED performance and lifespan are highly dependent on junction temperature.

• Thermal Resistance (R_θJC or R_θJA): The resistance to heat flow from the LED junction to the case (JC) or ambient air (JA). A lower value indicates better heat dissipation. Typical R_θJA might be 100-200 °C/W for an SMD package.
• Maximum Junction Temperature (T_J): The highest allowable temperature at the semiconductor junction, often 125°C or 150°C. Operating below this temperature is essential for long-term reliability.

3. Binning System Explanation

To ensure color and brightness consistency in production, LEDs are sorted into bins.

• Wavelength/Color Temperature Binning: LEDs are grouped based on their dominant wavelength or CCT. A typical binning scheme for white LEDs might have steps of 100K or 200K within a CCT range (e.g., 3000K, 3200K, 3500K).
• Luminous Flux Binning: LEDs are sorted according to their light output at a standard test current. Bins are defined by minimum and maximum lumen values (e.g., Bin A: 80-90 lm, Bin B: 90-100 lm).
• Forward Voltage Binning: Sorting based on V_F at a specific current helps in designing efficient driver circuits and achieving uniform brightness in parallel strings. Common bins might be in 0.1V steps.

4. Performance Curve Analysis

Graphical data is essential for understanding performance under varying conditions.

• I-V (Current-Voltage) Curve: This graph shows the relationship between forward current and forward voltage. It is non-linear, exhibiting a threshold voltage before current increases rapidly. This curve is vital for selecting current-limiting resistors or designing constant-current drivers.
• Temperature Characteristics: Graphs typically show how luminous flux and forward voltage change as a function of junction temperature. Light output generally decreases as temperature rises (thermal quenching), while forward voltage decreases slightly.
• Spectral Power Distribution (SPD): A plot of the relative intensity of light emitted at each wavelength. For white LEDs (phosphor-converted), this shows the blue pump LED peak and the broader phosphor emission spectrum.

5. Mechanical and Package Information

Precise mechanical data ensures correct PCB design and assembly.

• Package Dimensions: Detailed drawings with critical dimensions such as length, width, height, and lead spacing. A common SMD package like 2835 has nominal dimensions of 2.8mm x 3.5mm.
• Pad Layout (Footprint): The recommended copper pad pattern on the PCB for soldering. This includes pad size, shape, and spacing to ensure proper solder joint formation and mechanical strength.
• Polarity Identification: Clear marking on the LED package (often a notch, cut corner, or green marking on the cathode side) to indicate the anode and cathode for correct electrical connection.

6. Soldering and Assembly Guidelines

Proper handling is critical to prevent damage.

• Reflow Soldering Profile: A time-temperature graph specifying the preheat, soak, reflow, and cooling phases. Peak temperature must not exceed the LED's maximum tolerance (often 260°C for a few seconds) to avoid damaging the plastic lens or internal bonds.
• Precautions: Avoid mechanical stress on the lens. Use low-chloride, no-clean flux. Do not clean with ultrasonic methods after soldering. Ensure the soldering iron tip temperature is controlled if hand soldering is necessary.
• Storage Conditions: LEDs should be stored in a dry, anti-static environment with controlled temperature and humidity (e.g., <40°C, <60% RH) to prevent moisture absorption and oxidation of the leads.

7. Packaging and Ordering Information

Information for logistics and procurement.

• Packaging Specification: Typically supplied on embossed tape and reel compatible with automated pick-and-place machines. Reel size (e.g., 7-inch, 13-inch) and quantity per reel (e.g., 2000 pcs, 4000 pcs) are specified.
• Labeling Information: The reel label includes part number, quantity, lot number, date code, and binning information.
• Part Numbering Rule: The model number encodes key attributes like package size, color, CCT, flux bin, and voltage bin (e.g., LED2835-W-50-80-C1).

8. Application Suggestions

Guidance for effective implementation.

• Typical Application Circuits: Series connection with a current-limiting resistor for low-voltage DC supplies, or driven by a dedicated constant-current LED driver for optimal performance and efficiency, especially in multi-LED arrays or mains-powered applications.
• Design Considerations: Ensure adequate heat sinking on the PCB (thermal vias, copper area) to manage junction temperature. Consider optical design (lenses, diffusers) for the desired beam pattern. Account for forward voltage variation when designing parallel strings to prevent current imbalance.

9. Technical Comparison

This component, as a standardized SMD LED, offers differentiation through its balance of performance, cost, and reliability. Compared to through-hole LEDs, it enables miniaturization and automated assembly. Versus older LED packages, it typically offers higher efficacy (lumens per watt) and better thermal management due to an exposed thermal pad in some designs. The specific lifecycle revision (Revision: 2) indicates ongoing product refinement, potentially incorporating improvements in materials (e.g., more robust silicone lens) or semiconductor epitaxy for higher efficiency or better color consistency compared to earlier revisions.

10. Frequently Asked Questions

Answers based on typical technical parameter inquiries.

• Q: Can I drive this LED directly from a 5V supply? A: No. You must use a series current-limiting resistor or a constant-current driver. The resistor value is calculated as R = (Supply Voltage - V_F) / I_F. For a 3.2V LED at 20mA from a 5V supply, R = (5 - 3.2) / 0.02 = 90 Ohms.
• Q: Why do LEDs in parallel need individual resistors? A: Due to natural variations in V_F, LEDs connected directly in parallel will share current unevenly. One LED with a slightly lower V_F will draw more current, potentially leading to overheating and failure. Individual resistors help balance the currents.
• Q: What does "LifecyclePhase: Revision" mean? A: It indicates the product is in an active, supported state where documentation and specifications may be updated to reflect minor improvements, clarifications, or process changes without altering the product's form, fit, or core function.

11. Practical Use Case

Case: Backlighting for an Industrial Control Panel Display. A designer needs uniform, reliable, and long-lasting backlighting for a 5-inch LCD. They select this LED component in a cool white (6500K) variant. Multiple LEDs are arranged in an array on a flexible PCB strip around the edges of the display, utilizing side-firing or direct backlighting optics. A constant-current driver is designed to provide 60mA to each series string of 6 LEDs (total V_F ~19.2V). Thermal vias connect the LED pads to a large ground plane on the main PCB for heat dissipation. The high CRI ensures accurate color representation on the display. The "Revision 2" status gives confidence in the component's maturity and supply stability for this long-life industrial application.

12. Principle Introduction

An LED is a solid-state semiconductor device. It consists of a chip of semiconducting material doped with impurities to create a p-n junction. When a forward voltage is applied, electrons from the n-region recombine with holes from the p-region within the junction, releasing energy in the form of photons. The wavelength (color) of the emitted light is determined by the energy band gap of the semiconductor material. For example, Indium Gallium Nitride (InGaN) is used for blue and green LEDs, while Aluminum Gallium Indium Phosphide (AlGaInP) is used for red and amber. White LEDs are typically created by coating a blue or ultraviolet LED chip with a phosphor material that absorbs some of the blue light and re-emits it as yellow or a broader spectrum, combining to produce white light.

13. Development Trends

The LED industry continues to evolve with several clear trends. Efficiency (lumens per watt) is steadily increasing, reducing energy consumption for lighting. There is a strong focus on improving color quality, including higher CRI values (90+) and more precise color consistency (tighter binning). Miniaturization persists, enabling new applications in ultra-compact devices. Smart and connected lighting, integrating LEDs with sensors and controllers, is a growing field. Furthermore, research into novel materials like perovskites and quantum dots aims to achieve even higher efficiencies, better color rendering, and lower costs. The trend also includes enhancing reliability and lifetime under higher drive currents and operating temperatures.