SMD LED Yellow AlInGaP Datasheet - Package Dimensions - Forward Voltage 1.7-2.5V - Luminous Intensity 140-450mcd - English Technical Document

1. Product Overview

This document details the specifications for a surface-mount device (SMD) Light Emitting Diode (LED) utilizing an Aluminum Indium Gallium Phosphide (AlInGaP) semiconductor material to produce yellow light. SMD LEDs are designed for automated printed circuit board (PCB) assembly processes, offering a compact form factor ideal for space-constrained applications. Their primary function is to serve as status indicators, signal luminaries, or for front-panel backlighting in a wide array of electronic equipment.

1.1 Features

• Compliant with RoHS (Restriction of Hazardous Substances) directives.
• Packaged on 8mm tape wound onto 7-inch diameter reels for automated handling.
• Standardized EIA package footprint for design compatibility.
• Input/output compatible with integrated circuit (IC) logic levels.
• Designed for compatibility with automated pick-and-place assembly equipment.
• Suitable for infrared (IR) reflow soldering processes commonly used in surface-mount technology (SMT).
• Preconditioned to JEDEC Moisture Sensitivity Level 3, indicating a floor life of 168 hours at <30°C/60% RH after the sealed bag is opened.

1.2 Applications

This LED is suitable for various electronic systems requiring reliable visual indicators. Key application areas include telecommunications infrastructure, office automation equipment (printers, scanners), home appliances, and industrial control panels. Its specific uses encompass status indication (power on, standby, activity), symbolic illumination, and backlighting for front-panel displays or legends.

2. Technical Parameters Deep Objective Interpretation

2.1 Absolute Maximum Ratings

These values represent the stress limits beyond which permanent damage to the device may occur. Operation under or at these limits is not guaranteed. All ratings are specified at an ambient temperature (Ta) of 25°C.

• Power Dissipation (Pd): 75 mW. This is the maximum amount of power the LED package can dissipate as heat without exceeding its thermal limits.
• Peak Forward Current (I_FP): 80 mA. This is the maximum instantaneous forward current, permissible only under pulsed conditions (1/10 duty cycle, 0.1ms pulse width) to prevent overheating.
• DC Forward Current (I_F): 30 mA. This is the maximum continuous forward current recommended for reliable long-term operation.
• Operating & Storage Temperature Range: -40°C to +100°C. The device can function and be stored within this full temperature range.

2.2 Electrical & Optical Characteristics

These are the typical performance parameters measured under standard test conditions (Ta=25°C, I_F=20mA unless noted).

• Luminous Intensity (I_V): 140 - 450 mcd (millicandela). The amount of visible light emitted, measured within a specific viewing angle. The actual value is binned (see Section 3).
• Viewing Angle (2θ_1/2): 120 degrees (typical). This is the full angle at which the luminous intensity is half of its peak (on-axis) value. A 120° angle indicates a wide, diffuse emission pattern suitable for broad visibility.
• Peak Emission Wavelength (λ_P): 592 nm (typical). The wavelength at which the spectral power output is maximum.
• Dominant Wavelength (λ_d): 586 - 596 nm. This is the single wavelength perceived by the human eye that defines the color (yellow). It is derived from the CIE chromaticity coordinates and is also binned.
• Spectral Line Half-Width (Δλ): 15 nm (typical). The spectral width of the emitted light at half its maximum power. A value of 15nm is characteristic of AlInGaP LEDs, indicating a relatively pure color.
• Forward Voltage (V_F): 1.7 - 2.5 V. The voltage drop across the LED when driven at 20mA. This range accounts for normal semiconductor manufacturing variances.
• Reverse Current (I_R): 10 μA (max) at V_R=5V. LEDs are not designed for reverse bias operation; this parameter is for leakage current testing only.

3. Bin Rank System Explanation

To ensure color and brightness consistency in production, LEDs are sorted (binned) based on key parameters. This allows designers to select parts matching specific application requirements.

3.1 Luminous Intensity (I_V) Rank

LEDs are categorized into bins based on their measured luminous intensity at 20mA. The tolerance within each bin is +/-11%.

• R2: 140.0 - 180.0 mcd
• S1: 180.0 - 224.0 mcd
• S2: 224.0 - 280.0 mcd
• T1: 280.0 - 355.0 mcd
• T2: 355.0 - 450.0 mcd

3.2 Dominant Wavelength (WD) Rank

LEDs are also binned by their dominant wavelength to control color hue. The tolerance for each bin is +/- 1 nm.

• H: 586.0 - 588.5 nm
• J: 588.5 - 591.0 nm
• K: 591.0 - 593.5 nm
• L: 593.5 - 596.0 nm

A complete part number typically includes these bin codes to specify both brightness and color.

4. Performance Curve Analysis

While specific graphical data is referenced in the datasheet, the following interpretations are based on standard LED behavior and the provided parameters.

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

The forward voltage (V_F) has a positive temperature coefficient and increases logarithmically with current. The specified V_F range of 1.7V to 2.5V at 20mA is typical for yellow AlInGaP LEDs. Driving the LED at a constant current, rather than a constant voltage, is essential for stable light output.

4.2 Luminous Intensity vs. Forward Current

The light output (I_V) is approximately proportional to the forward current (I_F) within the recommended operating range. However, efficiency may drop at very high currents due to increased heat. The absolute maximum DC current is 30mA.

4.3 Temperature Characteristics

The luminous intensity of AlInGaP LEDs generally decreases as the junction temperature increases. For reliable performance across the -40°C to +100°C operating range, thermal management on the PCB (adequate copper area for heat sinking) should be considered, especially when operating near maximum current or in high ambient temperatures.

4.4 Spectral Distribution

The spectral output is centered around the peak wavelength of 592nm (yellow) with a typical half-width of 15nm. The dominant wavelength binning ensures the perceived color remains within a tight tolerance.

5. Mechanical & Packaging Information

5.1 Package Dimensions

The LED comes in a standard SMD package. Key dimensional notes include: all dimensions are in millimeters, and the general tolerance is ±0.2 mm unless otherwise specified. The lens color is clear, and the source color is yellow (AlInGaP).

5.2 Polarity Identification & Pad Design

The component has anode and cathode terminals. The recommended PCB attachment pad layout for infrared or vapor phase reflow soldering is provided to ensure proper solder joint formation and mechanical stability. Correct polarity orientation during assembly is crucial for device operation.

5.3 Tape and Reel Packaging

The LEDs are supplied on 8mm wide embossed carrier tape, sealed with a cover tape. The tape is wound onto 7-inch (178mm) diameter reels. Standard reel quantity is 5000 pieces. Packaging follows ANSI/EIA-481 specifications. A minimum order quantity of 500 pieces is available for remnants.

6. Soldering & Assembly Guidelines

6.1 Recommended IR Reflow Profile

For lead-free soldering processes, the profile should comply with J-STD-020B. Key parameters include a preheat zone (150-200°C, max 120 sec), a peak temperature not exceeding 260°C, and a time above liquidus (TAL) appropriate for the solder paste. The total time at peak temperature should be limited to 10 seconds maximum, and reflow should be performed a maximum of two times.

6.2 Hand Soldering

If hand soldering is necessary, use a soldering iron with a temperature not exceeding 300°C. The contact time should be limited to 3 seconds maximum, and it should be performed only once to prevent thermal damage to the plastic package and the semiconductor die.

6.3 Storage Conditions

Sealed Bag: Store at ≤30°C and ≤70% Relative Humidity (RH). The shelf life in the sealed moisture barrier bag with desiccant is one year.
After Bag Opening: The components have a Moisture Sensitivity Level (MSL) of 3. They must be subjected to IR reflow soldering within 168 hours (7 days) of being exposed to an environment of ≤30°C/60% RH. For longer storage after opening, store in a sealed container with desiccant or in a nitrogen-purged desiccator. Components exposed beyond 168 hours require baking at approximately 60°C for at least 48 hours before soldering to remove absorbed moisture and prevent \"popcorning\" during reflow.

6.4 Cleaning

If cleaning after soldering is required, use only specified solvents. Immerse the LED in ethyl alcohol or isopropyl alcohol at normal temperature for less than one minute. Do not use ultrasonic cleaning or unspecified chemical liquids, as they may damage the epoxy lens or package.

7. Application Suggestions

7.1 Typical Application Circuits

An LED is a current-driven device. To ensure consistent brightness, especially when driving multiple LEDs in parallel, always use a current-limiting resistor in series with each LED or each parallel string. The resistor value (R) can be calculated using Ohm's Law: R = (V_supply - V_F) / I_F, where V_F is the forward voltage of the LED at the desired current I_F (e.g., 20mA). Using the maximum V_F from the datasheet (2.5V) in the calculation will guarantee the current does not exceed the target even with part-to-part variation.

7.2 Design Considerations

• Thermal Management: Ensure the PCB layout provides adequate thermal relief, especially when operating at high currents or in high ambient temperatures, to maintain LED efficiency and longevity.
• ESD Protection: While not explicitly stated as sensitive, handling with standard ESD precautions is recommended for all semiconductor devices.
• Optical Design: The wide 120° viewing angle makes this LED suitable for applications requiring broad visibility. For focused beams, secondary optics (lenses) would be required.

7.3 Intended Use & Limitations

This LED is designed for use in ordinary electronic equipment. It is not rated for applications where failure could directly jeopardize life or health, such as in aviation, transportation control, medical life-support systems, or critical safety devices. For such applications, consult with the manufacturer for components with appropriate reliability qualifications.

8. Technical Comparison & Differentiation

This Yellow AlInGaP LED offers a balance of performance characteristics. Compared to older technology yellow LEDs (e.g., based on GaAsP), AlInGaP provides higher luminous efficiency, resulting in brighter output for the same drive current, and better color purity (narrower spectral width). The wide 120° viewing angle is a key differentiator from \"water clear\" lens LEDs that have a much narrower beam, making this part ideal for applications where the indicator needs to be seen from a wide range of angles without additional diffusers. The MSL 3 rating and compatibility with standard lead-free reflow profiles make it a robust choice for modern, high-volume SMT assembly lines.

9. Frequently Asked Questions (Based on Technical Parameters)

9.1 What resistor should I use with a 5V supply?

Using the maximum V_F of 2.5V and a target I_F of 20mA: R = (5V - 2.5V) / 0.02A = 125 Ohms. The nearest standard value of 120 Ohms or 130 Ohms would be suitable. The power rating of the resistor should be at least P = I²R = (0.02)² * 120 = 0.048W, so a standard 1/8W (0.125W) or 1/10W resistor is sufficient.

9.2 Can I drive this LED at 30mA continuously?

Yes, 30mA is the maximum recommended DC forward current. However, operating at the absolute maximum rating may reduce long-term reliability and increase junction temperature, which can decrease light output. For optimal lifespan and stability, driving at 20mA or lower is advisable if the luminous intensity meets the application requirement.

9.3 What does \"Bin Code\" mean when ordering?

The bin code specifies the guaranteed minimum and maximum for luminous intensity (e.g., T1: 280-355 mcd) and dominant wavelength (e.g., K: 591.0-593.5 nm). Specifying bin codes ensures you receive LEDs with consistent brightness and color from order to order, which is critical for multi-indicator panels or products where visual uniformity is important.

9.4 How long can I leave these LEDs on the bench after opening the bag?

For reliable soldering, you have 168 hours (7 days) at factory floor conditions (≤30°C/60% RH) after opening the moisture-sealed bag. If this time is exceeded, the LEDs must be baked at 60°C for 48 hours before attempting reflow soldering to prevent internal package damage from rapid moisture vaporization.

10. Practical Use Case

Scenario: Designing a status indicator panel for a network router. The panel requires 10 yellow LEDs to show link activity and system status. To ensure uniform appearance, the designer selects LEDs from the same intensity bin (e.g., S2: 224-280 mcd) and wavelength bin (e.g., J: 588.5-591.0 nm). Each LED is driven by a GPIO pin of a microcontroller via a 120-ohm current-limiting resistor to a 3.3V rail, resulting in a forward current of approximately ((3.3V - 2.1V typical)/120Ω) ≈ 10mA, which provides sufficient brightness while conserving power. The wide 120° viewing angle ensures the indicators are visible from anywhere in front of the device. The PCB layout includes the recommended solder pad footprint and is designed for assembly using a standard lead-free reflow profile with a peak temperature of 250°C.

11. 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 where they recombine. The energy released during this recombination is emitted as photons (light). The specific composition of the AlInGaP alloy determines the bandgap energy, which in turn defines the wavelength (color) of the emitted light—in this case, yellow (~592 nm). The clear epoxy lens encapsulates the semiconductor die, provides mechanical protection, and shapes the light output pattern to achieve the specified 120° viewing angle.

12. Development Trends

The general trend in SMD indicator LEDs continues toward higher luminous efficacy (more light output per unit of electrical input), enabling lower power consumption for the same brightness. Package sizes are also miniaturizing further, allowing for denser indicator arrays. There is a growing emphasis on tighter binning tolerances for both color and intensity to meet the demands of consumer electronics where visual consistency is paramount. Furthermore, compatibility with increasingly stringent environmental regulations (beyond RoHS, such as REACH) and the ability to withstand higher temperature lead-free soldering profiles remain key development drivers. The technology is mature, with incremental improvements focused on manufacturing yield, cost reduction, and reliability under harsh conditions.