SMD LED 19-21/G6C-AL1M2LY/3T Datasheet - Size 2.0x1.25x0.8mm - Voltage 1.7-2.3V - Brilliant Yellow Green - English Technical Document

1. Product Overview

The 19-21/G6C-AL1M2LY/3T is a surface-mount device (SMD) LED designed for modern electronic applications requiring compact size, high reliability, and consistent performance. This component belongs to the 19-21 package family, characterized by its miniature footprint, making it ideal for space-constrained designs.

1.1 Core Advantages and Product Positioning

The primary advantage of this LED is its significantly reduced size compared to traditional lead-frame type components. This miniaturization enables several key benefits for designers and manufacturers:

• Smaller Board Size: Allows for more compact PCB layouts.
• Higher Packing Density: Enables more components to be placed on a single board, increasing functionality.
• Reduced Storage Space: The smaller physical size of both the component and its packaging (8mm tape on 7-inch reels) optimizes logistics and inventory management.
• Lightweight Design: The minimal weight is crucial for portable and miniature applications where every gram counts.
• Manufacturing Compatibility: The device is fully compatible with standard automatic placement equipment and mainstream soldering processes, including infrared and vapor phase reflow, facilitating high-volume production.

1.2 Compliance and Environmental Standards

This product is designed with modern environmental and safety regulations in mind, ensuring broad market acceptance:

• Pb-free: Manufactured without lead, complying with RoHS (Restriction of Hazardous Substances) directives.
• Halogen-Free: Compliant with halogen-free requirements, with Bromine (Br) and Chlorine (Cl) content each below 900 ppm, and their sum below 1500 ppm.
• REACH Compliance: Adheres to the EU's REACH regulation concerning the registration, evaluation, authorization, and restriction of chemicals.

2. Technical Specifications and Objective Interpretation

This section provides a detailed, objective analysis of the device's electrical, optical, and thermal parameters as defined in the datasheet.

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 reliable designs.

• Reverse Voltage (V_R): 5V. Exceeding this voltage in reverse bias can cause immediate junction breakdown.
• Continuous Forward Current (I_F): 25 mA. The maximum DC current for continuous operation.
• Peak Forward Current (I_FP): 60 mA (Duty 1/10 @1kHz). Suitable for short pulse operation but not for DC.
• Power Dissipation (P_d): 60 mW. The maximum power the package can dissipate at Ta=25°C. Derating is necessary at higher ambient temperatures.
• Electrostatic Discharge (ESD) HBM: 2000V. Provides a measure of the device's robustness against static electricity, classified as Class 2 per the Human Body Model (HBM).
• Operating Temperature (T_opr): -40°C to +85°C. The ambient temperature range for reliable operation.
• Storage Temperature (T_stg): -40°C to +90°C.
• Soldering Temperature: Specifies the thermal profile limits for assembly.
  • Reflow Soldering: 260°C peak for a maximum of 10 seconds.
  • Hand Soldering: 350°C at the iron tip for a maximum of 3 seconds per terminal.

2.2 Electro-Optical Characteristics (Ta=25°C)

These are the typical performance parameters measured under standard test conditions (I_F = 5mA).

• Luminous Intensity (I_v): Ranges from 11.5 mcd (Min) to 28.5 mcd (Max), with a typical tolerance of ±11%. This defines the perceived brightness.
• Viewing Angle (2θ_1/2): 100 degrees (Typical). This wide viewing angle makes it suitable for applications where the LED may not be viewed head-on.
• Peak Wavelength (λ_p): 575 nm (Typical). The wavelength at which the spectral emission is strongest.
• Dominant Wavelength (λ_d): 569.5 nm to 577.5 nm. This parameter more closely correlates with the perceived color (Brilliant Yellow Green) and is subject to binning.
• Spectral Bandwidth (Δλ): 20 nm (Typical). The width of the emitted spectrum at half the maximum intensity (FWHM).
• Forward Voltage (V_F): 1.70V to 2.30V at I_F=5mA, with a typical tolerance of ±0.05V. This range is critical for current-limiting resistor calculation.
• Reverse Current (I_R): Maximum 10 μA at V_R=5V. The datasheet explicitly notes that the device is not designed for reverse operation; this parameter is for test purposes only.

3. Binning System Explanation

To ensure color and brightness consistency in production, LEDs are sorted into bins. This device uses three independent binning parameters.

3.1 Luminous Intensity Binning

LEDs are grouped based on their measured luminous intensity at I_F=5mA. The bin codes (L1, L2, M1, M2) represent ascending brightness levels, from 11.5-14.5 mcd (L1) to 22.5-28.5 mcd (M2). Designers can select a bin to meet specific brightness requirements.

3.2 Dominant Wavelength Binning

This binning ensures color consistency. The dominant wavelength is sorted into 2nm steps, with bin codes C16 (569.5-571.5nm) through C19 (575.5-577.5nm). A tighter bin selection results in a more uniform color appearance across multiple LEDs in an array.

3.3 Forward Voltage Binning

Forward voltage is binned in 0.1V steps, from code 19 (1.70-1.80V) to code 24 (2.20-2.30V). Knowing the V_F bin can help optimize the design of the current-limiting circuit for efficiency and to ensure consistent brightness when LEDs are driven in parallel.

4. Performance Curve Analysis

The datasheet provides several characteristic curves that are essential for understanding the device's behavior under non-standard conditions.

4.1 Relative Luminous Intensity vs. Forward Current

This curve shows that light output is not linearly proportional to current. It increases with current but may saturate or become less efficient at higher currents. Operating near the maximum rated current (25mA) may not yield proportional brightness gains and increases heat.

4.2 Relative Luminous Intensity vs. Ambient Temperature

LED efficiency decreases as junction temperature rises. This curve typically shows a decline in light output as ambient temperature increases from 25°C towards the maximum operating temperature (+85°C). This must be factored into designs for high-temperature environments.

4.3 Forward Current Derating Curve

This is a critical graph for thermal management. It shows the maximum allowable continuous forward current as a function of ambient temperature. As Ta increases, the maximum I_F must be reduced to prevent the junction temperature from exceeding safe limits and to maintain long-term reliability.

4.4 Spectrum Distribution and Radiation Pattern

The spectrum distribution plot confirms the monochromatic yellow-green output centered around 575nm. The radiation diagram (polar plot) visually represents the 100-degree viewing angle, showing the angular distribution of light intensity.

5. Mechanical and Package Information

5.1 Package Dimensions

The 19-21 package has nominal dimensions of 2.0mm in length, 1.25mm in width, and 0.8mm in height (tolerance ±0.1mm unless otherwise specified). The datasheet includes a detailed dimensional drawing showing pad layout, component outline, and the cathode identification mark. Accurate footprint design based on this drawing is essential for proper soldering and alignment.

5.2 Polarity Identification

The cathode is clearly marked on the device, as shown in the package diagram. Correct polarity must be observed during placement to ensure proper circuit operation.

6. Soldering and Assembly Guidelines

6.1 Reflow Soldering Profile

A detailed Pb-free reflow profile is provided:

• Pre-heating: 150-200°C for 60-120 seconds.
• Time Above Liquidus (217°C): 60-150 seconds.
• Peak Temperature: 260°C maximum.
• Time at Peak: 10 seconds maximum.
• Heating/Cooling Rate: Maximum 6°C/sec heating, 3°C/sec cooling.

It is critical to adhere to this profile to avoid thermal shock and ensure reliable solder joints without damaging the LED epoxy or die.

6.2 Critical Precautions

• Current Limiting: An external current-limiting resistor is mandatory. The LED is a current-driven device; a small change in forward voltage can cause a large change in current, leading to rapid failure (burn-out).
• Reflow Cycles: Reflow soldering should not be performed more than two times to prevent excessive thermal stress.
• Mechanical Stress: Avoid applying stress to the LED body during heating or bending the PCB after soldering.
• Hand Soldering: If necessary, use a soldering iron at ≤350°C for ≤3 seconds per terminal, with a power rating ≤25W. Allow a cooling interval of ≥2 seconds between terminals. Hand soldering carries a higher risk of damage.
• Repair: Avoid rework after soldering. If absolutely necessary, use a dual-head soldering iron to simultaneously heat both terminals and lift the component evenly to prevent pad damage.

7. Storage and Moisture Sensitivity

This component is moisture-sensitive. Improper handling can lead to "popcorning" (package cracking) during reflow due to rapid vaporization of absorbed moisture.

• Unopened Bag: Do not open the moisture-proof barrier bag until ready for use.
• Floor Life: After opening, LEDs must be used within 168 hours (7 days) if stored at ≤30°C and ≤60% Relative Humidity.
• Rebaking: If the storage time is exceeded or the desiccant indicator shows saturation, a bake at 60±5°C for 24 hours is required before use.
• Repackaging: Unused LEDs should be resealed in the moisture-proof bag with fresh desiccant.

8. Packaging and Ordering Information

8.1 Standard Packaging

The device is supplied in moisture-resistant packaging:

• Carrier Tape: 8mm wide tape.
• Reel: 7-inch diameter reel.
• Quantity: 3000 pieces per reel.
• Packaging: Includes desiccant and is sealed in an aluminum moisture-proof bag with appropriate labels.

8.2 Label Explanation

The reel label contains key information for traceability and identification:

• CPN: Customer's Product Number.
• P/N: Manufacturer's Product Number (e.g., 19-21/G6C-AL1M2LY/3T).
• QTY: Packing quantity.
• CAT: Luminous Intensity bin code (e.g., L1, M2).
• HUE: Chromaticity/Dominant Wavelength bin code (e.g., C17, C19).
• REF: Forward Voltage bin code (e.g., 20, 23).
• LOT No: Manufacturing lot number for traceability.

9. Application Suggestions

9.1 Typical Application Scenarios

• Backlighting: Ideal for dashboard indicators, switch backlighting, and flat backlighting for LCDs and symbols due to its wide viewing angle and consistent color.
• Telecommunication Equipment: Status indicators and keypad backlighting in phones, fax machines, and other communication devices.
• General Indication: Power status, mode indication, and other general-purpose visual feedback in consumer electronics, appliances, and industrial controls.

9.2 Design Considerations

• Current Drive: Always use a series resistor or constant current driver. Calculate the resistor value using R = (V_supply - V_F) / I_F, using the maximum V_F from the bin or datasheet to ensure current does not exceed limits under worst-case conditions.
• Thermal Management: For continuous operation at high ambient temperatures or near maximum current, consider PCB layout for heat dissipation. Avoid placing LEDs near other heat sources.
• ESD Protection: Implement standard ESD handling procedures during assembly. While the device has 2kV HBM protection, additional circuit-level protection may be needed in high-ESD-risk environments.
• Optical Design: The wide viewing angle may require light guides or diffusers if a more focused beam is desired. The water-clear resin lens provides good light extraction.

10. Technical Comparison and Differentiation

Compared to older through-hole LEDs or larger SMD packages, the 19-21 offers a compelling combination of miniaturization and performance. Its key differentiators are its very small 2.0x1.25mm footprint within the low-power indicator LED category and its use of AlGaInP semiconductor material, which provides high efficiency and saturated color in the yellow-green spectrum. Compared to some other miniaturized packages, it maintains a relatively standard pad layout and a robust moisture sensitivity level, making it a reliable choice for automated assembly.

11. Frequently Asked Questions (Based on Technical Parameters)

Q: Can I drive this LED directly from a 3.3V or 5V logic supply?
A: No. You must always use a current-limiting resistor. For example, with a 3.3V supply and a typical V_F of 2.0V at 5mA, a resistor of (3.3V - 2.0V) / 0.005A = 260Ω is required. Always use the maximum V_F from the datasheet (2.3V) for a conservative design: (3.3V - 2.3V) / 0.005A = 200Ω.

Q: Why is the storage and baking procedure so important?
A: SMD components absorb moisture from the air. During the high-temperature reflow soldering process, this moisture can turn to steam rapidly, creating enough internal pressure to crack the epoxy package ("popcorning"), leading to immediate or latent failure.

Q: What do the bin codes mean for my design?
A: If your application requires uniform appearance (e.g., an array of LEDs), you should specify tight bins for Dominant Wavelength (HUE) and Luminous Intensity (CAT). For a single indicator, standard bins are usually sufficient. The Forward Voltage (REF) bin can help if you are driving many LEDs in parallel to ensure even current distribution.

12. Practical Design and Usage Case

Scenario: Designing a multi-indicator status panel for a portable device.
A designer needs 5 identical yellow-green LEDs to show battery, connectivity, and mode statuses on a small, battery-powered gadget.

1. Component Selection: The 19-21 LED is chosen for its small size, low power consumption, and suitable color.
2. Binning Specification: To ensure all 5 LEDs look identical, the designer specifies a single, tight bin for both CAT (e.g., M1 only) and HUE (e.g., C18 only) on the purchase order.
3. Circuit Design: The device is powered by a 3.0V coin cell. Using the maximum V_F of 2.3V and a target I_F of 5mA for adequate brightness and long battery life, the current-limiting resistor is calculated: R = (3.0V - 2.3V) / 0.005A = 140Ω. A standard 150Ω resistor is selected.
4. PCB Layout: The compact 19-21 footprint allows the 5 LEDs to be placed closely together. The cathode mark on the silkscreen ensures correct orientation.
5. Assembly: The factory receives the reels, which are stored in their sealed bags until the production line is ready. The PCB undergoes a single reflow cycle using the specified profile.
6. Result: The final product has a clean, professional-looking indicator panel with uniformly bright and consistently colored LEDs, thanks to proper bin selection and circuit design.

13. Operating Principle Introduction

This LED is based on Aluminum Gallium Indium Phosphide (AlGaInP) semiconductor technology. When a forward voltage exceeding the diode's junction potential is applied, electrons and holes are injected into the active region from the n-type and p-type materials, respectively. These charge carriers recombine, releasing energy in the form of photons. The specific composition of the AlGaInP alloy determines the bandgap energy, which in turn defines the wavelength (color) of the emitted light—in this case, Brilliant Yellow Green (~575nm). The water-clear epoxy resin encapsulant protects the semiconductor die, acts as a lens to shape the light output, and enhances light extraction from the chip.

14. Technology Trends and Context

The 19-21 package represents the ongoing trend in electronics towards miniaturization and surface-mount technology. The move from leaded packages to SMDs like this one enables automated, high-speed pick-and-place assembly, significantly reducing manufacturing costs and increasing reliability by eliminating manual soldering steps. The use of AlGaInP material represents an advancement over older technologies like GaAsP, offering higher luminous efficiency and more vibrant, saturated colors. Furthermore, the compliance with Pb-free, halogen-free, and REACH standards reflects the industry-wide shift towards environmentally sustainable manufacturing processes and materials, which is now a critical requirement for global market access.