SMD LED 0603 Yellow AlInGaP Datasheet - Dimensions 1.6x0.8x0.6mm - Voltage 1.8-2.4V - Power 72mW - English Technical Document

1. Product Overview

This document details the specifications for a surface-mount device (SMD) Light Emitting Diode (LED) in a miniature 0603 package format. The device is designed for automated printed circuit board (PCB) assembly processes, making it suitable for high-volume manufacturing. Its compact size is ideal for space-constrained applications where board real estate is at a premium.

1.1 Core Advantages and Target Market

The primary advantages of this LED include its compatibility with automated pick-and-place equipment and infrared (IR) reflow soldering processes, which are standard in modern electronics manufacturing. It is compliant with relevant industry standards, including RoHS (Restriction of Hazardous Substances). The device is packaged on tape and reel for efficient handling in production lines.

The target applications are broad, covering sectors such as telecommunications (e.g., status indicators in routers, phones), office automation (e.g., backlighting for keyboards, panel indicators), home appliances, industrial equipment, and various lighting applications for signals, symbols, and indoor signboards. Its primary function is as a status indicator or a low-level illumination source.

2. Technical Parameters: In-Depth Objective Interpretation

This section provides a detailed, objective analysis of the LED's key performance parameters under standard test conditions (Ta=25°C).

2.1 Absolute Maximum Ratings

These ratings define the limits beyond which permanent damage to the device may occur. They are not intended for continuous operation.

• Power Dissipation (Pd): 72 mW. This is the maximum amount of power the LED package can dissipate as heat without degrading performance or reliability.
• Continuous Forward Current (IF): 30 mA DC. The maximum steady-state current that can be applied.
• Peak Forward Current: 80 mA, but only under pulsed conditions (1/10 duty cycle, 0.1ms pulse width). This allows for brief, high-intensity flashes.
• Reverse Voltage (VR): 5 V. Exceeding this voltage in reverse bias can cause immediate failure.
• Operating Temperature Range: -40°C to +85°C. The ambient temperature range within which the LED is guaranteed to operate within specification.
• Storage Temperature Range: -40°C to +100°C. The temperature range for non-operational storage.

2.2 Electro-Optical Characteristics

These are the typical performance parameters measured at a forward current (IF) of 20 mA.

• Luminous Intensity (Iv): Ranges from a minimum of 140.0 mcd to a maximum of 450.0 mcd. The actual value depends on the production bin (see Section 3). This is a measure of the perceived brightness to the human eye.
• Viewing Angle (2θ1/2): Approximately 110 degrees. This is the full angle at which the luminous intensity drops to half of its peak (on-axis) value. A 110-degree angle indicates a relatively wide viewing pattern.
• Peak Wavelength (λP): Typically 591 nm, placing it in the yellow region of the visible spectrum.
• Dominant Wavelength (λd): Specified between 584.5 nm and 594.5 nm. This is the single wavelength perceived by the human eye that best matches the LED's color.
• Spectral Bandwidth (Δλ): Approximately 15 nm. This defines the spread of wavelengths emitted around the peak, influencing color purity.
• Forward Voltage (VF): Between 1.8 V and 2.4 V at 20 mA. This is the voltage drop across the LED when operating. The tolerance for any given unit is +/-0.1V from its bin value.
• Reverse Current (IR): Maximum of 10 μA at VR=5V. This is a leakage current under reverse bias conditions.

3. Binning System Explanation

To ensure consistency in production, LEDs are sorted into bins based on key parameters. This allows designers to select parts that meet specific requirements for color and brightness uniformity in their application.

3.1 Forward Voltage (VF) Binning

LEDs are categorized into three voltage bins (D2, D3, D4), each with a 0.2V range. This is crucial for designing current-limiting circuits, especially when multiple LEDs are connected in series, to ensure even current distribution.

3.2 Luminous Intensity (Iv) Binning

Intensity is sorted into five bins (R2, S1, S2, T1, T2), with minimum values ranging from 140.0 mcd to 355.0 mcd. This allows selection based on required brightness levels. A tolerance of +/-11% applies within each bin.

3.3 Dominant Wavelength (WD) Binning

Color consistency is managed through four wavelength bins (H, J, K, L), covering the range from 584.5 nm to 594.5 nm. This ensures a uniform yellow hue across all LEDs used in an assembly.

4. Performance Curve Analysis

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

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

The I-V characteristic is non-linear. A small increase in voltage beyond the typical VF can lead to a large, potentially destructive, increase in current. Therefore, LEDs must be driven by a current-limited source, not a constant voltage source.

4.2 Luminous Intensity vs. Forward Current

Light output is generally proportional to forward current, but this relationship may become non-linear at very high currents. Operating at or below the recommended 20mA ensures stable performance and longevity.

4.3 Temperature Dependence

LED performance is temperature-sensitive. Typically, forward voltage decreases with increasing temperature, while luminous efficiency (light output per unit of electrical power) also decreases. This must be considered for applications operating over a wide ambient temperature range.

5. Mechanical and Package Information

5.1 Package Dimensions

The device conforms to the standard 0603 (1.6mm x 0.8mm) footprint. The typical height is approximately 0.6mm. Detailed dimensional drawings should be consulted for precise PCB land pattern design.

5.2 Polarity Identification

The cathode is typically marked on the device, often by a green tint on the corresponding side of the lens or a notch in the package. The PCB footprint should include a polarity indicator (e.g., a dot or "K" marking) to prevent incorrect placement.

6. Soldering and Assembly Guidelines

6.1 Recommended IR Reflow Profile

The datasheet recommends a profile compliant with J-STD-020B for lead-free processes. Key parameters include:

• Pre-heat: 150-200°C for a maximum of 120 seconds to gradually heat the board and components.
• Peak Temperature: Maximum of 260°C.
• Time Above Liquidus (TAL): Recommended to be 10 seconds maximum, and the reflow process should not be performed more than twice.

These parameters are critical to prevent thermal shock, solder joint defects, or damage to the LED's internal structure.

6.2 Storage Conditions

LEDs are moisture-sensitive devices (MSD).

• Sealed Package: Store at ≤30°C and ≤70% RH. Use within one year of the pack date.
• Opened Package: Store at ≤30°C and ≤60% RH. If exposed to ambient air for more than 168 hours, a bake-out at 60°C for at least 48 hours is required before soldering to prevent "popcorning" during reflow.

6.3 Cleaning

If cleaning is necessary after soldering, only use specified solvents such as ethyl alcohol or isopropyl alcohol at room temperature for less than one minute. Unspecified chemicals may damage the epoxy lens or package.

7. Packaging and Ordering Information

7.1 Packaging Specification

The LEDs are supplied on 12mm wide embossed carrier tape wound onto 7-inch (178mm) diameter reels. Each reel contains 4000 pieces. The tape pockets are sealed with a cover tape to protect components during shipping and handling.

7.2 Part Number Interpretation

The part number (e.g., LTST-010KSKT) typically encodes information about the package size (010 for 0603), lens color (K for water clear), and the chip material/color (SKT likely indicating the specific AlInGaP yellow formulation). The exact decoding should be verified with the manufacturer's nomenclature guide.

8. Application Suggestions

8.1 Typical Application Circuits

An LED is a current-driven device. The most common driving method is using a series current-limiting resistor. The resistor value (R) is calculated using Ohm's Law: R = (Vcc - VF) / IF, where Vcc is the supply voltage, VF is the LED forward voltage (use max from bin for reliability), and IF is the desired forward current (e.g., 20mA). For constant brightness across a range of Vcc or temperature, a constant current driver circuit is recommended.

8.2 Design Considerations

• Thermal Management: Although power dissipation is low, ensuring adequate PCB copper area around the pads can help dissipate heat, especially in high ambient temperatures or when driven at higher currents.
• ESD Protection: LEDs can be sensitive to electrostatic discharge. Standard ESD handling precautions should be observed during assembly.
• Optical Design: The wide 110-degree viewing angle makes it suitable for applications where the indicator needs to be seen from various angles. For more directed light, secondary optics (lenses) may be required.

9. Technical Comparison and Differentiation

Compared to older through-hole LEDs, this SMD type offers significant advantages: much smaller size, suitability for automated assembly (lower cost), better reliability due to lack of leads, and compatibility with double-sided PCB assembly. Within the SMD LED family, the 0603 package offers a balance between miniaturization and ease of handling/manufacturing, being larger than 0402 but smaller than 0805 packages. The use of AlInGaP (Aluminum Indium Gallium Phosphide) technology for yellow light typically offers higher efficiency and better temperature stability compared to older technologies like GaAsP on GaP.

10. Frequently Asked Questions (Based on Technical Parameters)

10.1 Can I drive this LED directly from a 3.3V or 5V microcontroller pin?

No, not directly. A microcontroller GPIO pin is a voltage source, not a current source. Connecting the LED directly would attempt to pull current limited only by the pin's internal resistance and the LED's dynamic resistance, likely exceeding the absolute maximum current and destroying the LED. Always use a series current-limiting resistor or a dedicated LED driver.

10.2 Why is there such a wide range in Luminous Intensity (140-450 mcd)?

This range represents the total spread across all production bins. By specifying a particular bin code (e.g., T2), you can secure LEDs with a much tighter intensity range (355-450 mcd), ensuring consistent brightness in your product. The binning system allows for cost optimization by using different bins for different brightness requirements.

10.3 What happens if I solder this LED with a standard leaded solder profile?

Leaded solder profiles have higher peak temperatures (often > 260°C). Exceeding the recommended 260°C peak can cause several issues: degradation of the epoxy lens (yellowing), damage to the wire bonds inside the package, or thermal stress leading to early failure. Always use the recommended lead-free or a carefully controlled low-temperature profile.

11. Practical Design and Usage Case

Case: Designing a Status Indicator Panel for a Network Switch

A designer needs multiple yellow status LEDs for port activity indicators on a network switch front panel. The panel is space-constrained, requiring a small component. The 0603 package is selected. To ensure uniform appearance, the designer specifies a single wavelength bin (e.g., K: 589.5-592.0 nm) and a single intensity bin (e.g., S2: 224-280 mcd) for all LEDs in the Bill of Materials (BOM). The drive circuit uses a 3.3V rail. Assuming a VF of 2.2V (mid-bin D3) and a target IF of 20mA, the current-limiting resistor is calculated as R = (3.3V - 2.2V) / 0.020A = 55 Ohms. A standard 56-Ohm resistor is chosen. The PCB land pattern is designed according to the datasheet's recommended pad layout to ensure reliable soldering and proper self-alignment during reflow.

12. Operating Principle Introduction

An LED is a semiconductor diode. When a forward voltage is applied, electrons from the n-type semiconductor and holes from the p-type semiconductor are injected into the active region (the junction). When an electron recombines with a hole, energy is released. In an LED, this energy is released in the form of a photon (light). The specific wavelength (color) of the light is determined by the bandgap energy of the semiconductor materials used in the active region. For this yellow LED, the material system is AlInGaP, which has a bandgap corresponding to yellow light (~590 nm). The water-clear epoxy lens encapsulates the chip, provides mechanical protection, and helps shape the light output beam.

13. Technology Trends

The general trend in SMD LEDs is toward several key areas:

1. Increased Efficiency: Ongoing material science improvements (like better AlInGaP and InGaN epitaxy) yield more lumens per watt (lm/W), reducing power consumption for the same light output.
2. Miniaturization: Packages continue to shrink (e.g., 0402, 0201) to enable ever-smaller end products, though this presents challenges for thermal management and handling.
3. Higher Reliability and Stability: Improvements in packaging materials and processes lead to longer lifetimes and better performance consistency over temperature and time.
4. Integrated Solutions: There is a move toward LEDs with built-in current-limiting resistors or even simple driver ICs in the same package, simplifying circuit design for the end user.
5. Color Consistency: Tighter binning tolerances and improved manufacturing processes are continuously improving color uniformity across production batches.

This particular 0603 AlInGaP yellow LED represents a mature, reliable, and cost-effective solution within this evolving technological landscape.