SMD LED 120-Degree Viewing Angle Green - 2.8x3.8mm Package - 3.8V Max - 80mW Power - English Datasheet

1. Product Overview

This document details the specifications for a high-performance, surface-mount green LED designed for modern electronic applications. The device utilizes InGaN (Indium Gallium Nitride) technology to produce a bright green light source. Its primary design goals are compatibility with automated assembly processes, reliability in reflow soldering, and adherence to environmental standards. The LED is packaged in a standard EIA-compliant format on 8mm tape, supplied on 7-inch reels, making it suitable for high-volume production lines.

2. In-Depth Technical Parameter Analysis

2.1 Absolute Maximum Ratings

These ratings define the limits beyond which permanent damage to the device may occur. Operation under these conditions is not guaranteed.

• Power Dissipation (Pd): 80 mW. This is the maximum amount of power the LED can dissipate as heat at an ambient temperature (Ta) of 25°C. Exceeding this limit risks thermal damage to the semiconductor junction.
• Peak Forward Current (I_FP): 100 mA. This is the maximum allowable pulsed current, specified under a strict 1/10 duty cycle with a 0.1ms pulse width. It is significantly higher than the DC rating to allow for brief, high-intensity pulses.
• DC Forward Current (I_F): 20 mA. This is the recommended continuous operating current for standard operation and is the condition under which most optical characteristics are measured.
• Operating Temperature Range: -40°C to +85°C. The device is guaranteed to function within this ambient temperature range.
• Storage Temperature Range: -40°C to +100°C. The device can be stored without applied power within this wider range.

2.2 Electrical & Optical Characteristics

These parameters are measured at Ta=25°C and I_F=20mA, unless otherwise noted, and represent typical operating performance.

• Luminous Intensity (I_V): 280 to 900 mcd (millicandela). This wide range indicates the device is available in multiple brightness bins. The intensity is measured using a sensor filtered to match the human eye's photopic response (CIE curve).
• Viewing Angle (2θ_1/2): 120 degrees. This is a very wide viewing angle, defined as the full angle where the luminous intensity drops to half of its peak axial value. It is suitable for applications requiring broad illumination or visibility from wide angles.
• Peak Emission Wavelength (λ_P): 518 nm. This is the wavelength at which the spectral output of the LED is at its maximum intensity.
• Dominant Wavelength (λ_d): 520 to 535 nm. This is the single wavelength perceived by the human eye that defines the color of the light, derived from the CIE chromaticity diagram. It is the key parameter for color specification.
• Spectral Line Half-Width (Δλ): 35 nm. This parameter, also known as Full Width at Half Maximum (FWHM), describes the spectral purity of the light. A value of 35nm is typical for a green InGaN LED.
• Forward Voltage (V_F): 2.8V to 3.8V. This is the voltage drop across the LED when operating at 20mA. The range accommodates normal manufacturing variations and is further defined by bin codes.
• Reverse Current (I_R): 10 μA (max) at V_R=5V. This is a leakage current specification. Critical Note: The datasheet explicitly states the device is not designed for reverse operation. Applying a reverse voltage can damage the LED.

3. Bin Code System Explanation

To ensure consistency in production runs, LEDs are sorted into "bins" based on key parameters. This allows designers to select parts with tightly controlled characteristics for their application.

3.1 Forward Voltage Binning (D-Codes)

Bins ensure LEDs in a circuit have similar voltage drops, promoting current sharing in parallel configurations. Tolerance per bin is ±0.1V.

• D7: 2.80V - 3.00V
• D8: 3.00V - 3.20V
• D9: 3.20V - 3.40V
• D10: 3.40V - 3.60V
• D11: 3.60V - 3.80V

3.2 Luminous Intensity Binning (T/U/V-Codes)

This controls the brightness output. Tolerance per bin is ±11%.

• T1: 280.0 - 355.0 mcd
• T2: 355.0 - 450.0 mcd
• U1: 450.0 - 560.0 mcd
• U2: 560.0 - 710.0 mcd
• V1: 710.0 - 900.0 mcd

3.3 Dominant Wavelength Binning (AP/AR-Codes)

This ensures precise color consistency. Tolerance per bin is ±1nm.

• AP: 520.0 - 525.0 nm
• AQ: 525.0 - 530.0 nm
• AR: 530.0 - 535.0 nm

4. Performance Curve Analysis

While specific graphs are referenced (Fig.1, Fig.5), the datasheet indicates the availability of typical characteristic curves which would normally include:

• Relative Luminous Intensity vs. Forward Current: Shows how light output increases with current, typically in a sub-linear fashion at higher currents due to heating and efficiency droop.
• Forward Voltage vs. Forward Current: Demonstrates the diode's exponential I-V relationship.
• Relative Luminous Intensity vs. Ambient Temperature: Illustrates the decrease in light output as junction temperature rises, a critical factor for thermal management.
• Spectral Distribution: A plot of relative intensity versus wavelength, showing the peak at ~518nm and the 35nm FWHM.
• Viewing Angle Pattern: A polar plot showing the angular distribution of light intensity, confirming the 120-degree viewing angle.

5. Mechanical & Package Information

5.1 Device Dimensions

The LED conforms to a standard EIA package outline. Key dimensional tolerances are ±0.2mm unless otherwise specified. The package features a water-clear lens, which maximizes light extraction and provides the specified wide viewing angle.

5.2 Polarity Identification & PCB Footprint

The datasheet includes a recommended printed circuit board (PCB) attachment pad layout for infrared or vapor phase reflow soldering. This footprint is designed to ensure proper solder joint formation, reliable electrical connection, and adequate thermal relief. Polarity is indicated on the device body (typically a cathode mark) and must be correctly aligned with the corresponding anode and cathode pads on the PCB layout.

6. Soldering & Assembly Guidelines

6.1 Reflow Soldering Profile

The device is compatible with infrared reflow soldering processes. A lead-free soldering profile compliant with JEDEC standard J-STD-020B is suggested. Key parameters include:

• Pre-heat: 150°C to 200°C.
• Pre-heat Time: Maximum 120 seconds.
• Peak Temperature: Maximum 260°C.
• Time Above Liquidus: Recommended to follow solder paste manufacturer specifications and JEDEC guidelines to ensure reliable solder joints without subjecting the LED to excessive thermal stress.

Note: The profile must be characterized for the specific PCB design, component mix, solder paste, and oven used in production.

6.2 Hand Soldering

If hand soldering is necessary, extreme care must be taken:

• Iron Temperature: Maximum 300°C.
• Soldering Time: Maximum 3 seconds per joint.
• Limit: One soldering cycle only. Repeated heating can damage the package and the semiconductor die.

7. Packaging & Handling

7.1 Tape and Reel Specifications

The LEDs are supplied in industry-standard embossed carrier tape (8mm width) sealed with cover tape, wound onto 7-inch (178mm) diameter reels.

• Quantity per Reel: 2000 pieces.
• Minimum Order Quantity (MOQ) for Remainders: 500 pieces.
• Packaging Standard: Conforms to ANSI/EIA-481 specifications.
• Missing Components: A maximum of two consecutive empty pockets in the tape is allowed.

7.2 Moisture Sensitivity & Storage

The LED package is moisture-sensitive. Proper handling is required to prevent "popcorning" (package cracking) during reflow.

• Sealed Bag (with Desiccant): Store at ≤30°C and ≤70% RH. Use within one year of bag seal date.
• After Bag Opening: Store at ≤30°C and ≤60% RH. It is strongly recommended to complete the IR reflow process within 168 hours (7 days) of exposure.
• Extended Storage (Opened): Store in a sealed container with desiccant or in a nitrogen desiccator.
• Rebaking: Components exposed for more than 168 hours should be baked at approximately 60°C for at least 48 hours prior to soldering to remove absorbed moisture.

8. Application Notes & Design Considerations

8.1 Drive Method

LEDs are current-operated devices. For consistent and reliable operation:

• Constant Current Drive: Always use a constant current source or a current-limiting resistor in series with a voltage source to set the forward current (I_F).
• Avoid Parallel Connection: Connecting multiple LEDs directly in parallel from a single voltage source with one resistor is not recommended. Small variations in forward voltage (V_F) between LEDs will cause significant current imbalance, leading to uneven brightness and potential over-current in some devices. Use individual current-limiting resistors for each LED or separate constant current drivers.
• Reverse Voltage Protection: As the device is not designed for reverse bias, ensure circuit design prevents the application of any reverse voltage across the LED.

8.2 Thermal Management

Although power dissipation is relatively low (80mW), proper thermal design extends lifetime and maintains optical performance.

• PCB Layout: Use the recommended pad layout which often includes thermal relief connections.
• Copper Area: Increasing the copper area connected to the LED's thermal pad (if applicable) or cathode/anode pads helps dissipate heat.
• Ambient Temperature: Ensure the operating ambient temperature remains within the specified range. Derate the maximum forward current if the ambient temperature approaches the upper limit.

8.3 Cleaning

If post-solder cleaning is required:

• Recommended Solvent: Use only alcohol-based cleaners such as ethyl alcohol or isopropyl alcohol.
• Process: Immerse at normal room temperature for less than one minute.
• Avoid: Do not use unspecified chemical liquids which may damage the plastic lens or package material.

9. Technical Comparison & Differentiation

Key features that distinguish this LED in the market include:

• Extremely Wide Viewing Angle (120°): Offers superior side visibility compared to standard LEDs with narrower beams, ideal for status indicators and backlighting where wide-angle viewing is essential.
• RoHS & Green Product Compliance: Manufactured without hazardous substances like lead, mercury, and cadmium, meeting global environmental regulations.
• Full Compatibility with Automated Assembly: Tape-and-reel packaging, standard EIA footprint, and compatibility with IR reflow processes enable seamless integration into high-speed SMT (Surface Mount Technology) production lines.
• Comprehensive Binning: Three-parameter binning (V_F, I_V, λ_d) allows for precise selection for applications demanding tight uniformity in brightness, color, and electrical behavior.

10. Frequently Asked Questions (FAQ)

Q: Can I drive this LED with a 5V supply?
A: Yes, but you must use a series current-limiting resistor. Calculate the resistor value using R = (V_supply - V_F) / I_F. For a 5V supply and a typical V_F of 3.2V at 20mA, R = (5 - 3.2) / 0.02 = 90 ohms. Use the maximum V_F from the datasheet (3.8V) for a conservative design to ensure current does not exceed 20mA for any unit in the batch.

Q: What is the difference between Peak Wavelength and Dominant Wavelength?
A: Peak Wavelength (λ_P) is the physical wavelength where the LED emits the most optical power. Dominant Wavelength (λ_d) is a calculated value based on the CIE color chart that represents the single wavelength the human eye perceives the color to be. λ_d is the critical parameter for color specification in visual applications.

Q: Why is there a 168-hour floor life after opening the moisture barrier bag?
A: The plastic LED package can absorb moisture from the air. During the high-temperature reflow soldering process, this trapped moisture can vaporize rapidly, creating internal pressure that can crack the package ("popcorning"). The 168-hour limit is the safe exposure time assumed for the package to remain below a critical moisture level.

Q: Can I use this for automotive interior lighting?
A: The operating temperature range (-40°C to +85°C) covers typical automotive interior requirements. However, the datasheet specifies the LED is for "ordinary electronic equipment." For automotive applications, especially exterior or safety-critical ones, components typically require AEC-Q102 qualification and specific reliability testing. Consultation with the manufacturer for application-specific reliability data is essential.