SMD LED Yellow Green 120-Degree Viewing Angle - Package Dimensions - Forward Voltage 2.0V Typ - Power Dissipation 72mW - English Technical Datasheet

1. Product Overview

This document details the specifications for a surface-mount device (SMD) Light Emitting Diode (LED) utilizing a diffused lens and an AlInGaP (Aluminum Indium Gallium Phosphide) semiconductor material to produce a yellow-green light output. The device is designed for automated printed circuit board (PCB) assembly processes, making it suitable for high-volume manufacturing. Its compact form factor and compatibility with standard SMD placement equipment cater to space-constrained applications across various electronic sectors.

1.1 Core Features and Advantages

• Compliance: The product is compliant with relevant environmental regulations (e.g., RoHS).
• Packaging: Supplied in industry-standard 8mm tape on 7-inch diameter reels, facilitating automated pick-and-place operations.
• Process Compatibility: Fully compatible with automated placement equipment and infrared (IR) reflow soldering processes commonly used in surface-mount technology (SMT) assembly lines.
• Electrical Interface: I.C. (Integrated Circuit) compatible, allowing for direct drive from standard logic-level outputs with appropriate current limiting.
• Reliability: Subjected to preconditioning tests accelerated to JEDEC Level 3 standards to ensure robustness against moisture-induced stress during soldering.

1.2 Target Markets and Applications

This LED is engineered for a broad spectrum of electronic equipment where reliable, compact status indication or illumination is required. Primary application areas include:

• Telecommunication Equipment: Status indicators on routers, modems, and handsets.
• Office Automation: Panel indicators on printers, copiers, and scanners.
• Consumer Electronics & Home Appliances: Power, mode, or function indicators.
• Industrial Equipment: Machine status, fault, or operational mode signaling.
• General Indication: Front panel backlighting for symbols, icons, or general status luminaires.

2. In-Depth Technical Parameter Analysis

The following section provides a detailed, objective interpretation of the key electrical, optical, and thermal parameters that define the device's performance envelope.

2.1 Absolute Maximum Ratings

These ratings define the stress limits beyond which permanent damage to the device may occur. Operation at or near these limits is not recommended for reliable performance.

• Power Dissipation (Pd): 72 mW. This is the maximum allowable power the LED package can dissipate as heat at an ambient temperature (Ta) of 25°C. Exceeding this limit risks overheating the semiconductor junction, leading to accelerated degradation or failure.
• DC Forward Current (IF): 30 mA. The maximum continuous forward current that can be applied to the LED.
• Peak Forward Current: 80 mA (under pulsed conditions: 1/10 duty cycle, 0.1ms pulse width). This rating is relevant for brief, high-current pulses but should not be used for continuous operation.
• Operating Temperature Range: -40°C to +85°C. The ambient temperature range over which the device is specified to operate correctly.
• Storage Temperature Range: -40°C to +100°C. The temperature range for safe storage when the device is not powered.

2.2 Electro-Optical Characteristics

These parameters are measured under standard test conditions (Ta=25°C, IF=20mA) and represent the typical performance of the device.

• Luminous Intensity (Iv): Ranges from a minimum of 56.0 mcd to a maximum of 180.0 mcd, with a typical value implied within this binning range. Intensity is measured using a sensor filtered to match the photopic (human eye) response curve (CIE standard).
• Viewing Angle (2θ1/2): 120 degrees (typical). This is the full angle at which the luminous intensity drops to half of its value measured on-axis. A 120-degree angle indicates a wide, diffused light emission pattern suitable for broad-area illumination or viewing from wide angles.
• Peak Emission Wavelength (λP): Approximately 575 nm. This is the wavelength at the highest point of the optical emission spectrum.
• Dominant Wavelength (λd): Approximately 571 nm (typical). This is the single wavelength perceived by the human eye that defines the color of the LED, derived from the CIE chromaticity coordinates. It is the key parameter for color specification.
• Spectral Line Half-Width (Δλ): Approximately 15 nm (typical). This indicates the spectral purity; a value of 15nm is characteristic of AlInGaP-based yellow-green LEDs.
• Forward Voltage (VF): 2.0V (typical), with a maximum of 2.4V at 20mA. This is the voltage drop across the LED when operating at the specified current. It is crucial for designing the current-limiting circuitry.
• Reverse Current (IR): Maximum 10 μA at a Reverse Voltage (VR) of 5V. This parameter is for test purposes only; the device is not designed for operation under reverse bias.

3. Binning System Explanation

To ensure consistency in mass production, LEDs are sorted into performance bins. This allows designers to select parts that meet specific minimum criteria for their application.

3.1 Forward Voltage (Vf) Binning

LEDs are categorized based on their forward voltage drop at 20mA. This helps in designing power supplies and ensuring uniform brightness when multiple LEDs are connected in parallel.

• Bin D2: Vf = 1.8V to 2.0V
• Bin D3: Vf = 2.0V to 2.2V
• Bin D4: Vf = 2.2V to 2.4V

Tolerance within each bin is ±0.1V.

3.2 Luminous Intensity (Iv) Binning

This is the primary binning for brightness. Parts are sorted into groups with defined minimum and maximum luminous intensity values.

• Bin P2: 56.0 – 71.0 mcd
• Bin Q1: 71.0 – 90.0 mcd
• Bin Q2: 90.0 – 112.0 mcd
• Bin R1: 112.0 – 140.0 mcd
• Bin R2: 140.0 – 180.0 mcd

Tolerance on each intensity bin is ±11%.

3.3 Dominant Wavelength (Wd) Binning

This binning ensures color consistency. LEDs are grouped by their dominant wavelength, which directly correlates to the perceived hue.

• Bin B: λd = 564.5 – 567.5 nm
• Bin C: λd = 567.5 – 570.5 nm
• Bin D: λd = 570.5 – 573.5 nm
• Bin E: λd = 573.5 – 576.5 nm

Tolerance for each wavelength bin is ±1 nm.

4. Performance Curve Analysis

While specific graphs are referenced in the datasheet, their implications are critical for design.

4.1 Current vs. Voltage (I-V) Characteristic

The I-V curve for an LED is exponential. The typical forward voltage (2.0V) is specified at 20mA. Designers must use a current-limiting resistor or constant-current driver to ensure the operating point remains stable, as a small change in voltage can cause a large change in current, potentially exceeding maximum ratings.

4.2 Luminous Intensity vs. Forward Current

Luminous intensity is approximately proportional to forward current within the operating range. Operating above the recommended DC current (20mA) may increase brightness but will also increase junction temperature, potentially reducing lifespan and causing color shift.

4.3 Temperature Dependence

LED performance is temperature-sensitive. Typically, forward voltage decreases with increasing temperature, while luminous intensity also decreases. Operating at the upper limit of the temperature range (85°C) will result in lower light output compared to operation at 25°C.

5. Mechanical and Packaging Information

5.1 Device Dimensions and Polarity

The LED package has specific physical dimensions critical for PCB footprint design. The datasheet includes a detailed dimensional drawing. Polarity is indicated by a cathode mark (typically a notch, green dot, or other marking on the package). Correct orientation is essential for circuit operation.

5.2 Recommended PCB Pad Design

A land pattern (footprint) is provided for the PCB. Adhering to this recommended pad layout is crucial for achieving reliable solder joints during reflow soldering, ensuring proper mechanical attachment and thermal dissipation.

5.3 Tape and Reel Packaging Specifications

The device is supplied in embossed carrier tape with a protective cover tape, wound onto 7-inch (178mm) diameter reels. Key specifications include:

• Pocket Pitch: Defined in the tape dimensions.
• Components per Reel: 2000 pieces.
• Missing Components: A maximum of two consecutive empty pockets is allowed per specification.
• The packaging conforms to ANSI/EIA-481 standards for component packaging.

6. Soldering and Assembly Guidelines

6.1 IR Reflow Soldering Profile (Pb-Free)

A suggested temperature profile compliant with J-STD-020B is provided for lead-free solder processes. Key parameters include:

• Preheat: A gradual ramp to activate flux and minimize thermal shock.
• Soak Zone: A plateau to allow the entire assembly to reach a uniform temperature.
• Reflow (Liquidus): Peak temperature must not exceed 260°C, and the time above 217°C (liquidus temperature for typical Pb-free solder) should be controlled (e.g., 10 seconds max).
• Cooling: A controlled cool-down rate.

Note: The exact profile must be characterized for the specific PCB assembly, considering board thickness, component density, and solder paste used.

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 pad.
• Limit: Soldering should be performed only once to avoid thermal damage to the plastic package and internal wire bonds.

6.3 Cleaning

If post-solder cleaning is required, only specified solvents should be used to avoid damaging the LED's plastic lens and package. Recommended agents include ethyl alcohol or isopropyl alcohol. The LED should be immersed at normal temperature for less than one minute.

7. Storage and Handling Cautions

7.1 Moisture Sensitivity

The LED package is moisture-sensitive. Prolonged exposure to ambient humidity can lead to popcorn cracking during reflow soldering.

• Sealed Package: Store at ≤30°C and ≤70% RH. Use within one year of the pack date.
• Opened Package: For components removed from the moisture-barrier bag, the recommended storage ambient is ≤30°C and ≤60% RH.
• Floor Life: It is recommended to complete IR reflow soldering within 168 hours (7 days) after opening the original packaging.
• Extended Storage/Baking: 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.

7.2 Drive Method

LEDs are current-operated devices. To ensure uniform brightness when connecting multiple LEDs, they should be driven with a constant current source. Connecting LEDs directly in parallel with a single voltage source and resistor is not recommended due to variations in forward voltage (Vf) between individual devices, which can lead to significant differences in current and, consequently, brightness. A series connection with an appropriate current-limiting resistor or the use of individual resistors for each parallel LED is preferred.

8. Application Notes and Design Considerations

8.1 Current Limiting

Always use a series resistor or constant-current driver to set the forward current to the desired value (e.g., 20mA). The resistor value can be calculated using Ohm's Law: R = (Vsupply - Vf_LED) / I_desired. Use the maximum Vf from the datasheet (2.4V) for a conservative design to ensure the current does not exceed limits even with a low-Vf LED.

8.2 Thermal Management

While the power dissipation is low (72mW), effective thermal management on the PCB can help maintain performance and longevity, especially in high ambient temperature environments or when driving at higher currents. Ensuring a good thermal connection from the LED pads to the PCB copper can help dissipate heat.

8.3 Optical Design

The 120-degree viewing angle and diffused lens provide a wide, soft light emission. This makes the LED suitable for applications requiring even illumination over an area or where the indicator needs to be visible from a wide range of angles, without the need for secondary optics like light pipes in many cases.

9. Frequently Asked Questions (Based on Technical Parameters)

9.1 What is the difference between Peak Wavelength and Dominant Wavelength?

Peak Wavelength (λP) is the physical wavelength at the highest intensity point in the LED's emission spectrum. Dominant Wavelength (λd) is a calculated value based on human color perception (CIE coordinates) that represents the single wavelength of the perceived color. For design purposes, especially regarding color matching, the Dominant Wavelength and its binning are more relevant.

9.2 Can I drive this LED at 30mA continuously?

While the Absolute Maximum Rating for DC Forward Current is 30mA, the Electro-Optical Characteristics are specified at 20mA. Operating at 30mA continuously will generate more heat, potentially reducing luminous efficiency and lifespan. For reliable long-term operation, it is advisable to design for a current at or below the typical test condition of 20mA.

9.3 How do I interpret the binning codes when ordering?

You must specify the desired bin codes for Vf, Iv, and Wd based on your application's requirements for voltage consistency, brightness level, and color point. For example, an order might specify bins D3 (Vf), R1 (Iv), and D (Wd) to get parts with medium voltage, high brightness, and a specific yellow-green hue.

10. Operational Principles and Technology Context

10.1 AlInGaP Semiconductor Technology

This LED uses an Aluminum Indium Gallium Phosphide (AlInGaP) semiconductor material. This material system is highly efficient for producing light in the amber, yellow, and green regions of the visible spectrum. Compared to older technologies, AlInGaP LEDs offer higher brightness, better efficiency, and improved temperature stability.

10.2 Diffused Lens Function

The diffused (non-clear) lens contains scattering particles that mix the light emitted from the small semiconductor chip. This process broadens the viewing angle (to 120 degrees) and creates a more uniform, softer appearance by eliminating the bright "hot spot" typically seen in LEDs with clear lenses. This is ideal for applications where the LED is viewed directly.