LED SMD 3.0x3.0x0.55mm White Specification - Forward Voltage 3.0-3.8V - Power 3.42W - Luminous Flux up to 300lm - English Technical Document

1. Product Overview

This technical document details the specifications for a high-brightness white light emitting diode (LED) designed for surface-mount technology (SMT) applications. The LED is constructed using a blue semiconductor chip combined with a phosphor coating to produce white light. It is housed in a compact SMC (Surface-Mount Chip) package, making it suitable for automated assembly processes. The product is characterized by its high luminous output, wide viewing angle, and reliability under standard operating conditions.

1.1 Features

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• SMC Package: The device utilizes a robust surface-mount chip package designed for mechanical stability and efficient thermal management.
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• Extremely Wide Viewing Angle: A typical viewing angle (2θ1/2) of 120 degrees ensures broad and uniform light distribution, ideal for area lighting and backlighting.
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• SMT Assembly Compatibility: Fully compatible with standard surface-mount assembly lines, including pick-and-place machines and reflow soldering processes.
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• Tape and Reel Packaging: Supplied in tape and reel format to facilitate high-speed, automated manufacturing.
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• Moisture Sensitivity Level (MSL): Rated at Level 3 per industry standards. This requires that the device be baked if exposed to ambient conditions beyond the specified time before reflow soldering to prevent popcorn cracking.
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• RoHS Compliance: The product is manufactured in compliance with the Restriction of Hazardous Substances (RoHS) directive, ensuring it is free from lead, mercury, cadmium, and other restricted materials.
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1.2 Applications

This versatile LED is engineered for a wide range of lighting applications, including but not limited to:

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• Backlighting: Primary light source for LCD panels in televisions, computer monitors, and instrument displays.
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• Indicator Lights: Illumination for switches, push-buttons, and status symbols in consumer electronics and industrial equipment.
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• General Illumination: Suitable for indoor decorative lighting, accent lighting, and tubular light fixtures.
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• Display Systems: Use in indoor signage, informational displays, and advertising panels.
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• General Purpose Lighting: Any application requiring a compact, efficient, and bright white light source.
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2. Technical Parameters Deep-Dive Objective Interpretation

2.1 Electrical and Optical Characteristics

The core performance metrics are defined under standardized test conditions at a solder point temperature (Ts) of 25°C. These parameters are critical for circuit design and system integration.

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• Forward Voltage (VF): Measured at a forward current (IF) of 800mA, the voltage drop across the LED typically ranges from 3.0V to 3.8V, with a nominal value of 3.4V. This parameter is essential for determining the required driver voltage and power supply design.
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• Reverse Current (IR): With a reverse voltage (VR) of 5V applied, the leakage current is specified at a maximum of 10 µA. This indicates the diode's reverse-bias characteristics.
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• Luminous Flux (Φ): The total visible light output, measured in lumens (lm). At 800mA, the luminous flux has a typical value of 250lm, with a minimum of 210lm and a maximum of 300lm. This defines the brightness level of the LED.
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• Viewing Angle (2θ1/2): The full angle at which luminous intensity is half of the maximum intensity. A typical value of 120 degrees signifies a very wide beam pattern.
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• Thermal Resistance (RTHJ-S): The junction-to-solder point thermal resistance is typically 12°C/W. This value is crucial for thermal management calculations, as it defines how easily heat can dissipate from the semiconductor junction to the PCB.
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2.2 Absolute Maximum Ratings

These ratings define the stress limits beyond which permanent damage to the device may occur. Operation under or at these limits is not guaranteed and should be avoided in reliable designs.

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• Power Dissipation (PD): The maximum allowable power dissipation is 3420 mW. Exceeding this limit can lead to overheating and catastrophic failure.
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• Forward Current (IF): The maximum continuous forward current is 900 mA.
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• Peak Forward Current (IFP): A short-duration peak current of 1200 mA is permissible under pulsed conditions (1/10 duty cycle, 0.1ms pulse width).
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• Reverse Voltage (VR): The maximum allowable reverse voltage is 5V. Applying higher reverse voltage can break down the junction.
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• Electrostatic Discharge (ESD): The Human Body Model (HBM) ESD withstand voltage is 2000V. While the yield is over 90% at this level, proper ESD handling precautions during assembly are still mandatory.
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• Temperature Ranges: Operating temperature (TOPR) spans from -40°C to +85°C. Storage temperature (Tstg) ranges from -40°C to +100°C. The maximum junction temperature (TJ) is 125°C.
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3. Binning System Explanation

To ensure consistency in mass production, LEDs are sorted into bins based on key electrical and optical parameters measured at IF=800mA. This allows designers to select parts that meet specific application requirements for voltage and brightness.

3.1 Forward Voltage (VF) Binning

The forward voltage is categorized into bins denoted by codes like G0, H0, I0, J0, K0, etc. Each code corresponds to a specific voltage range (e.g., G0: 2.8-3.0V, H0: 3.0-3.2V). This helps in matching LEDs for series connections to ensure uniform current distribution.

3.2 Luminous Flux (Φ) Binning

The luminous flux output is binned using codes such as A210, A220, A230, etc., where the number indicates the minimum luminous flux in lumens for that bin (e.g., A210: 210-220 lm, A220: 220-230 lm). This enables precise control over the brightness level in the final application.

4. Performance Curve Analysis

While specific graphical data is referenced in the document as \"Typical optical characteristics curves,\" the electrical parameters allow for inferring key performance trends.

4.1 Current-Voltage (I-V) Relationship

The forward voltage increases with forward current in a non-linear manner, typical of diode characteristics. Designers must account for this when selecting current-limiting resistors or constant-current drivers to ensure the LED operates within its specified voltage range at the desired current.

4.2 Temperature Dependence

The forward voltage typically decreases with increasing junction temperature. Conversely, luminous output generally degrades as temperature rises. The specified thermal resistance of 12°C/W is a key factor; for example, dissipating 3W would raise the junction temperature by approximately 36°C above the solder point temperature. Proper heatsinking on the PCB is essential to maintain performance and longevity.

4.3 Spectral Characteristics

As a phosphor-converted white LED based on a blue chip, the emitted light spectrum consists of a primary blue peak from the chip and a broader yellow/white emission from the phosphor. The combined spectrum defines the correlated color temperature (CCT) and color rendering index (CRI), though specific values are not detailed in this document.

5. Mechanical and Packaging Information

5.1 Package Dimensions

The LED has a compact footprint with overall dimensions of 3.00mm in length, 3.00mm in width, and a height of 0.55mm. All dimension tolerances are ±0.1mm unless otherwise specified. The package includes a lens that contributes to the wide viewing angle.

5.2 Pad Design and Polarity Identification

The bottom view of the package shows two solder pads. The pad with the larger area or a specific marking (often a \"+\" or \"-\" symbol or a chamfered corner) denotes the anode (positive) terminal. The other pad is the cathode (negative). Correct polarity orientation during PCB layout and assembly is critical for proper operation. The recommended solder pad pattern is provided to ensure reliable solder joint formation and mechanical strength.

6. Soldering and Assembly Guidelines

6.1 SMT Reflow Soldering Instructions

The LED is designed to withstand standard infrared or convection reflow soldering profiles. A typical lead-free (SnAgCu) reflow profile with a peak temperature not exceeding 260°C is recommended. The temperature ramp rates and soak times should follow the guidelines for MSL Level 3 components to prevent thermal shock and moisture-related failures.

6.2 Handling and Repair Precautions

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• Soldering Iron Use: If manual soldering or rework is necessary, a temperature-controlled soldering iron with a tip temperature below 350°C and a very short contact time (less than 3 seconds) should be used to avoid damaging the plastic package or the internal wire bonds.
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• Repairing: Components should not be re-soldered more than twice. Excessive heat exposure can degrade performance.
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• Cautions: Avoid applying mechanical stress to the lens. Do not touch the lens surface with bare hands or contaminated tools, as oils and residues can affect light output and cause discoloration.
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7. Packaging and Ordering Information

7.1 Packaging Specifications

The LEDs are packaged in embossed carrier tape with specific pocket dimensions to hold the device securely. The tape is wound onto reels. Standard reel dimensions and the quantity per reel are defined to fit automated equipment.

7.2 Label and Moisture Protection

Each reel includes a label specifying part number, quantity, bin codes, date code, and other traceability information. The product is packed with moisture-resistant barriers (such as desiccant and humidity indicator cards) inside sealed bags, as required for MSL Level 3 components. These bags are then placed in protective cardboard boxes for shipment and storage.

8. Application Suggestions and Design Considerations

8.1 Thermal Management in Design

Given the power dissipation capability of up to 3.42W, effective thermal management on the printed circuit board (PCB) is paramount. Designers should use a PCB with adequate copper area (thermal pads or planes) connected to the LED's solder pads to act as a heatsink. Thermal vias can be used to transfer heat to inner or bottom layers. Maintaining the junction temperature well below the maximum rating of 125°C is essential for long-term reliability and preventing luminous flux depreciation.

8.2 Electrical Drive Considerations

To ensure stable and consistent light output, driving the LED with a constant current source is highly recommended, as opposed to a constant voltage source with a series resistor. This compensates for variations in forward voltage (both unit-to-unit and with temperature). The driver should be rated for the maximum continuous current of 900mA and provide appropriate over-current and reverse-voltage protection.

8.3 Optical Design for Target Applications

For backlighting applications, an array of these LEDs combined with a light guide plate (LGP) and diffuser films can create uniform surface illumination. The 120-degree viewing angle is beneficial for reducing the number of LEDs required. For indicator use, the wide angle ensures visibility from various directions.

9. Technical Comparison and Differentiation

While a direct comparison with other products is not provided in the source document, key differentiating features of this LED can be inferred from its parameters:

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• High Luminous Flux Density: Delivering up to 300lm from a 3.0x3.0mm footprint represents a high brightness-to-size ratio.
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• Balanced Thermal Performance: A thermal resistance of 12°C/W is competitive for an SMC package, enabling higher drive currents without excessive temperature rise when properly heatsinked.
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• Robust SMT Compatibility: The MSL Level 3 rating and compatibility with standard reflow profiles make it suitable for high-volume manufacturing environments with proper handling.
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10. Frequently Asked Questions Based on Technical Parameters

10.1 What is the maximum current I can drive this LED with?

The absolute maximum continuous forward current is 900mA. However, the recommended operating current for the specified luminous flux and voltage is 800mA. Operating at 900mA will produce more light but also generate more heat, requiring exceptional thermal management to stay within the junction temperature limit. The peak pulsed current can be 1200mA under specific conditions.

10.2 How do I interpret the binning codes when ordering?

You must specify both the forward voltage bin (e.g., I0 for 3.2-3.4V) and the luminous flux bin (e.g., A250 for 250-260 lm) to ensure you receive LEDs with the precise electrical and optical characteristics needed for your design, especially for series or parallel configurations.

10.3 What precautions are needed for storage before assembly?

As an MSL Level 3 component, the device must be stored in its original sealed moisture barrier bag. Once the bag is opened, the \"floor life\" (time allowed exposed to ambient factory conditions) is typically 168 hours (7 days) at ≤ 30°C/60% RH. If this time is exceeded, the components must be baked according to the recommended profile (e.g., 125°C for 24 hours) before reflow soldering.

11. Real-World Application Cases

11.1 Case Study: LCD Monitor Backlight Unit

An array of 50 of these LEDs can be arranged along the edge of a 24-inch monitor's light guide plate. Driven at 700mA each (derated for longer life), they provide sufficient luminous flux for a bright, uniform display. The SMT package allows for a slim monitor profile, and the wide viewing angle of the LEDs contributes to consistent edge-lit illumination.

11.2 Case Study: Industrial Control Panel Indicators

Used as status indicators on a factory machine control panel, a single LED per indicator, driven by a 5V supply through a simple current-limiting resistor calculated for ~800mA. The high brightness and wide viewing angle ensure the indicator is clearly visible to operators from various angles in a well-lit industrial environment.

12. Principle of Operation Introduction

The white light is generated through a process called phosphor conversion. The core of the LED is a semiconductor chip that emits blue light when electrical current passes through it in the forward direction (electroluminescence). This blue light is then partially absorbed by a layer of yellow (or a mix of red and green) phosphor material deposited on or around the chip. The phosphor re-emits this energy as light of longer wavelengths (yellow). The combination of the remaining blue light and the converted yellow light appears white to the human eye. The exact shade of white (cool, neutral, warm) is determined by the composition and thickness of the phosphor layer.

13. Technology Development Trends

The evolution of SMD white LEDs like this one is driven by several key trends: Increased Efficiency (lm/W): Ongoing research focuses on improving the internal quantum efficiency of the blue chip and the conversion efficiency of the phosphor to extract more lumens per watt of electrical input. Improved Color Quality: Developments in phosphor technology aim to enhance the Color Rendering Index (CRI) for more natural-looking light, especially for high-end display and general lighting. Miniaturization and Higher Power Density: The push for smaller packages capable of handling higher drive currents and power dissipation continues, enabling brighter and more compact lighting solutions. Enhanced Reliability and Lifetime: Advancements in packaging materials, die attach technologies, and phosphor stability are extending the operational lifetime and lumen maintenance of LEDs under harsh operating conditions.