SMD LED Yellow Green AlInGaP 120-Degree Viewing Angle - Package Dimensions - Forward Voltage 1.8-2.4V @20mA - Luminous Intensity 56-180mcd - English Technical Datasheet

1. Product Overview

This document details the specifications for a compact, high-performance Surface-Mount Device (SMD) Light Emitting Diode (LED). The device utilizes an Aluminum Indium Gallium Phosphide (AlInGaP) semiconductor material to produce a Yellow Green light output. It is designed in a standard EIA package format, making it compatible with automated pick-and-place assembly equipment and standard infrared (IR) reflow soldering processes. The LED is supplied on industry-standard 12mm tape mounted on 7-inch diameter reels, facilitating high-volume manufacturing.

1.1 Core Advantages and Target Market

The primary advantages of this LED include its miniature footprint, suitability for automated assembly, and compliance with lead-free (Pb-free) reflow soldering profiles. It is engineered for space-constrained applications where reliable performance and efficient assembly are critical. The target markets span a wide range of consumer and industrial electronics, including but not limited to telecommunications equipment (e.g., cordless and cellular phones), portable computing devices (e.g., notebook computers), networking hardware, home appliances, and indoor signage or display backlighting. Its primary function is as a status indicator, signal luminary, or for front-panel illumination.

2. In-Depth Technical Parameter Analysis

All electrical and optical characteristics are specified at an ambient temperature (Ta) of 25°C unless otherwise stated. Understanding these parameters is crucial for proper circuit design and ensuring long-term reliability.

2.1 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 design.

• Power Dissipation (Pd): 72 mW. This is the maximum amount of power the package can dissipate as heat.
• Continuous Forward Current (IF): 30 mA DC. The maximum steady-state current for reliable operation.
• Peak Forward Current: 80 mA, permissible only under pulsed conditions (1/10 duty cycle, 0.1ms pulse width).
• Reverse Voltage (VR): 5 V. The device is not designed for reverse bias operation; exceeding this voltage may cause breakdown.
• Operating Temperature Range: -40°C to +85°C. The ambient temperature range for normal functionality.
• Storage Temperature Range: -40°C to +100°C. The safe temperature range when the device is not powered.

2.2 Electro-Optical Characteristics at Ta=25°C (IF=20mA)

These are the typical performance parameters under standard test conditions.

• Luminous Flux (Φv): Ranges from a minimum of 0.17 lm to a maximum of 0.54 lm. The total visible light output.
• Luminous Intensity (Iv): Corresponds to the flux, ranging from 56 mcd (millicandela) to 180 mcd. This is a measure of perceived brightness in a specific direction.
• Viewing Angle (2θ1/2): 120 degrees (typical). Defined as the full angle at which the luminous intensity is half of the intensity at the center (0°). This indicates a wide, diffuse light pattern.
• Peak Emission Wavelength (λp): 574 nm (typical). The wavelength at which the spectral output is strongest.
• Dominant Wavelength (λd): Specified from 564.5 nm to 576.5 nm. This is the single wavelength perceived by the human eye that defines the color (Yellow Green).
• Spectral Line Half-Width (Δλ): 15 nm (typical). The bandwidth of the emitted spectrum at half the peak intensity, indicating color purity.
• Forward Voltage (VF): Ranges from 1.8 V (min) to 2.4 V (max) at 20mA. The voltage drop across the LED when conducting.
• Reverse Current (IR): Maximum of 10 μA at VR=5V. A small leakage current when a reverse voltage is applied.

3. Binning System Explanation

To ensure consistency in production, LEDs are sorted into performance bins. This allows designers to select parts that meet specific requirements for brightness, voltage, and color.

3.1 Luminous Flux/Intensity Binning

The luminous output is categorized into five bins (A2, B1, B2, C1, C2). For example, bin C2 offers the highest output with a luminous flux between 0.42 lm and 0.54 lm, corresponding to an intensity of 140-180 mcd. Bin A2 is the lowest output grade. Designers must consult the datasheet for the specific binning of their ordered part number to predict light output accurately.

3.2 Forward Voltage Binning

The forward voltage is binned into three categories (D2, D3, D4) with a tolerance of ±0.1V within each bin.

• Bin D2: VF = 1.8V - 2.0V
• Bin D3: VF = 2.0V - 2.2V
• Bin D4: VF = 2.2V - 2.4V

This is critical for designing current-limiting circuits, especially in battery-powered applications where voltage consistency affects current and thus brightness.

3.3 Hue (Dominant Wavelength) Binning

The color hue is controlled by binning the dominant wavelength into four groups (B, C, D, E), each with a tolerance of ±1 nm.

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

This ensures color uniformity across multiple LEDs used in an array or display.

4. Performance Curve Analysis

Graphical data provides deeper insight into device behavior under varying conditions.

4.1 Forward Current vs. Forward Voltage (I-V Curve)

The I-V curve is non-linear, characteristic of a diode. The forward voltage increases logarithmically with current. At the typical operating current of 20mA, the VF falls within the binned ranges specified. Designers must use this curve to ensure the driving circuit provides adequate voltage, especially at low temperatures where VF increases.

4.2 Relative Luminous Intensity vs. Forward Current

This curve shows that light output is approximately proportional to forward current in the standard operating range. However, driving the LED above its absolute maximum DC current (30mA) is not recommended, as it can lead to accelerated degradation, reduced lifetime, and potential failure due to excessive heat.

4.3 Relative Luminous Intensity vs. Ambient Temperature

The luminous intensity of AlInGaP LEDs decreases as the ambient temperature rises. This curve is vital for applications operating in elevated temperature environments. Designers may need to de-rate the expected light output or implement thermal management if consistent brightness is required across a wide temperature range.

4.4 Spectral Distribution

The spectral graph shows a narrow peak centered around 574 nm (Yellow Green) with a typical half-width of 15 nm. This confirms the color purity and the specific wavelength region of the emitted light.

5. Mechanical and Package Information

5.1 Device Package Dimensions

The LED conforms to a standard SMD package outline. All critical dimensions are provided in millimeters with a general tolerance of ±0.2 mm. The drawing includes the body length, width, height, and the location and size of the solder pads/terminals. The lens is specified as \"Water Clear.\"

5.2 Recommended PCB Attachment Pad Layout

A land pattern diagram is provided for designing the printed circuit board (PCB). This shows the recommended copper pad size and spacing to ensure proper solder joint formation during reflow, good mechanical adhesion, and effective heat dissipation from the LED terminals.

5.3 Polarity Identification

The datasheet should indicate the cathode/anode identification on the device package, typically via a marking, a notch, or a different pad size. Correct polarity must be observed during assembly to prevent damage.

6. Soldering and Assembly Guidelines

6.1 IR Reflow Soldering Profile

A detailed reflow temperature profile is provided, compliant with J-STD-020B for lead-free (Pb-free) processes. Key parameters include:

• Pre-heat/Soak: Ramp-up to 150-200°C.
• Time Above Liquidus (TAL): Recommended time maintained.
• Peak Temperature: Must not exceed 260°C.
• Time within 5°C of Peak: Should be limited (e.g., 10 seconds max).

The profile emphasizes a controlled ramp-up and cool-down to minimize thermal shock to the component.

6.2 Manual Soldering (Soldering Iron)

If manual rework is necessary, the iron tip temperature should not exceed 300°C, and the soldering time per lead should be limited to a maximum of 3 seconds. Soldering should be performed only once per pad to avoid damaging the package or internal die attach.

6.3 Cleaning

If post-solder cleaning is required, only specified alcohol-based solvents like ethyl alcohol or isopropyl alcohol should be used. The LED should be immersed at normal temperature for less than one minute. Unspecified chemical cleaners may damage the epoxy lens or package.

6.4 Storage and Moisture Sensitivity

The LEDs are moisture-sensitive. When sealed in the original moisture-proof bag with desiccant, they should be stored at ≤30°C and ≤70% RH and used within one year. Once the bag is opened, the \"floor life\" begins. Components should be stored at ≤30°C and ≤60% RH and are recommended to be IR-reflowed within 168 hours (7 days). For storage beyond this period, they should be kept in a sealed container with desiccant or in a nitrogen ambient. Components exceeding the floor life require a baking procedure (approximately 60°C for at least 48 hours) before soldering to remove absorbed moisture and prevent \"popcorning\" during reflow.

7. Packaging and Ordering Information

7.1 Tape and Reel Specifications

The device is supplied on embossed carrier tape with a protective cover tape. Detailed dimensions for the tape pocket, pitch, and reel are provided, conforming to ANSI/EIA-481 standards. The standard reel is 7 inches in diameter and contains 3000 pieces. A minimum packing quantity of 500 pieces is available for remainder orders. The tape ensures compatibility with high-speed automated assembly equipment.

8. Application Notes and Design Considerations

8.1 Typical Application Circuits

The LED requires a current-limiting element in series, such as a resistor. The resistor value (R) can be calculated using Ohm's Law: R = (Vsupply - VF) / IF, where VF is the forward voltage of the LED at the desired current IF. Using the maximum VF from the bin ensures the current does not exceed the limit even with component tolerances. For precision or variable brightness, constant current drivers are recommended.

8.2 Thermal Management

While the power dissipation is low (72mW max), effective thermal design on the PCB is still important for longevity, especially in high ambient temperatures or when driven at high currents. Ensuring adequate copper area connected to the thermal pads of the LED helps dissipate heat and maintains stable light output.

8.3 Design for Manufacturing (DFM)

Adhere to the recommended PCB pad layout and the specified reflow profile. Ensure the pick-and-place machine nozzle is compatible with the package size. Verify the tape feeder setup matches the tape and reel specifications.

9. Technical Comparison and Differentiation

Compared to older technology like Gallium Phosphide (GaP) LEDs, AlInGaP LEDs offer significantly higher luminous efficiency, resulting in brighter output at the same current. The 120-degree viewing angle provides a wider, more diffuse light pattern compared to narrow-viewing-angle LEDs, making it ideal for status indicators that need to be visible from various angles. The standard EIA package ensures drop-in compatibility with a vast ecosystem of assembly tools and existing PCB designs.

10. Frequently Asked Questions (FAQ)

10.1 What is the difference between luminous flux and luminous intensity?

Luminous flux (measured in lumens, lm) is the total amount of visible light emitted by the source in all directions. Luminous intensity (measured in candela or millicandela, mcd) is the amount of light emitted in a specific direction. This LED's datasheet provides both, with intensity measured along the central axis (0°).

10.2 Can I drive this LED without a current-limiting resistor?

No. An LED is a current-driven device. Connecting it directly to a voltage source will cause excessive current to flow, rapidly destroying it. Always use a series resistor or a constant-current driver.

10.3 Why does the light output decrease at high temperature?

This is a fundamental characteristic of semiconductor materials. Increased temperature affects the internal quantum efficiency of the light-emitting junction, reducing the number of photons generated per electron. The performance curves in the datasheet quantify this effect.

10.4 How do I interpret the bin codes when ordering?

The full part number may include suffixes denoting specific bins for luminous intensity (e.g., C2), forward voltage (e.g., D3), and dominant wavelength (e.g., E). Consult the manufacturer's ordering guide. If a specific bin is not called out, you will receive parts from the standard production distribution across the specified bins.

11. Practical Design and Usage Examples

11.1 Low-Power Status Indicator

In a battery-powered IoT sensor node, the LED can be used as a low-power \"heartbeat\" indicator. Using a microcontroller GPIO pin, the LED can be pulsed at a low duty cycle (e.g., 10ms on, 990ms off) to indicate device activity while consuming minimal average current, thus extending battery life.

11.2 Front Panel Backlighting for a Keypad

An array of these LEDs, placed behind a diffuser, can provide uniform backlighting for membrane keypads or legends on control panels. The wide 120-degree viewing angle helps achieve even illumination across the panel surface. Designers must ensure proper spacing and current drive to meet the desired brightness level.

12. Technology Principle Introduction

This LED is based on Aluminum Indium Gallium Phosphide (AlInGaP) semiconductor technology. When a forward voltage is applied across the p-n junction, electrons and holes are injected into the active region. They recombine, releasing energy in the form of photons. The specific ratio of Aluminum, Indium, Gallium, and Phosphide in the crystal lattice determines the bandgap energy, which directly defines the wavelength (color) of the emitted light—in this case, Yellow Green (~574 nm). The \"Water Clear\" epoxy lens encapsulates the semiconductor die, provides environmental protection, and shapes the light output pattern.

13. Industry Trends and Developments

The general trend in SMD LEDs is toward higher luminous efficacy (more light output per watt of electrical input), improved color consistency through tighter binning, and enhanced reliability under harsh environmental conditions. There is also ongoing development in miniaturization (smaller package sizes) and integration (e.g., LEDs with built-in ICs for control). For indicator applications, the focus remains on cost-effectiveness, reliability, and compatibility with advanced assembly processes like double-sided reflow. The technology described in this datasheet represents a mature and widely adopted solution for standard indicator needs.