SMD LED 17-21/Y2C Brilliant Yellow Datasheet - Size 1.6x0.8x0.6mm - Voltage 2.0V - Power 60mW - English Technical Document

1. Product Overview

This document details the specifications for a surface-mount device (SMD) LED identified as 17-21/Y2C-AN1P2/3T. It is a mono-color, brilliant yellow LED designed for modern electronic applications requiring compact, efficient, and reliable indicator or backlighting solutions. The product is Pb-free and compliant with major environmental and safety standards including RoHS, EU REACH, and halogen-free requirements (Br <900 ppm, Cl <900 ppm, Br+Cl < 1500 ppm).

1.1 Core Advantages and Target Market

The 17-21 SMD LED package offers significant advantages over traditional lead-frame components. Its miniature footprint (1.6mm x 0.8mm) enables higher packing density on printed circuit boards (PCBs), leading to reduced board size and ultimately smaller end-user equipment. The lightweight nature of the SMD package makes it ideal for portable and miniature applications. Primary target markets include consumer electronics, telecommunications equipment (for indicators and keypad backlighting), automotive dashboard and switch backlighting, and general-purpose indicator applications where space and weight are critical constraints.

2. Technical Parameter Deep-Dive

This section provides an objective and detailed analysis of the LED's key electrical, optical, and thermal characteristics.

2.1 Absolute Maximum Ratings

These ratings define the stress limits beyond which permanent damage to the device may occur. Operation outside these limits is not recommended.

• Reverse Voltage (V_R): 5V. Exceeding this voltage in reverse bias can cause junction breakdown.
• Continuous Forward Current (I_F): 25 mA. The maximum DC current for reliable operation.
• Peak Forward Current (I_FP): 60 mA. This is permissible only under pulsed conditions (duty cycle 1/10 @ 1kHz).
• Power Dissipation (P_d): 60 mW. The maximum power the package can dissipate at Ta=25°C.
• Electrostatic Discharge (ESD) Human Body Model (HBM): 2000V. This indicates a moderate level of ESD robustness; proper handling procedures are still essential.
• Operating Temperature (T_opr): -40°C to +85°C. The ambient temperature range for normal operation.
• Storage Temperature (T_stg): -40°C to +90°C.
• Soldering Temperature (T_sol): Reflow: 260°C max for 10 seconds. Hand soldering: 350°C max for 3 seconds per terminal.

2.2 Electro-Optical Characteristics

Measured at a forward current (I_F) of 20 mA and an ambient temperature (T_a) of 25°C, unless otherwise specified.

• Luminous Intensity (I_v): 28.5 mcd (Min), 72.0 mcd (Max). The typical value is not specified, indicating a wide binning range (see Section 3). A ±11% tolerance applies.
• Viewing Angle (2θ_1/2): 140 degrees (Typical). This wide viewing angle makes the LED suitable for applications where visibility from off-axis angles is important.
• Peak Wavelength (λ_p): 591 nm (Typical). The wavelength at which the spectral emission is strongest.
• Dominant Wavelength (λ_d): 585.5 nm (Min), 594.5 nm (Max). This defines the perceived color of the light. A ±1nm tolerance applies.
• Spectral Bandwidth (Δλ): 15 nm (Typical). The width of the emitted spectrum at half the maximum intensity (FWHM).
• Forward Voltage (V_F): 1.7V (Min), 2.0V (Typ), 2.4V (Max) at I_F=20mA. This parameter is crucial for current-limiting resistor calculation in circuit design.
• Reverse Current (I_R): 10 μA (Max) at V_R=5V. The device is not designed for operation in reverse bias; this parameter is for leakage test purposes only.

3. Binning System Explanation

To manage manufacturing variations, LEDs are sorted into performance bins. This allows designers to select parts that meet specific brightness and color consistency requirements for their application.

3.1 Luminous Intensity Binning

Bins are defined by minimum and maximum luminous intensity values at I_F=20mA.

• N1: 28.5 mcd to 36.0 mcd
• N2: 36.0 mcd to 45.0 mcd
• P1: 45.0 mcd to 57.0 mcd
• P2: 57.0 mcd to 72.0 mcd

3.2 Dominant Wavelength Binning

Bins are defined by minimum and maximum dominant wavelength values at I_F=20mA.

• D3: 585.5 nm to 588.5 nm
• D4: 588.5 nm to 591.5 nm
• D5: 591.5 nm to 594.5 nm

The combination of an intensity bin code (e.g., P1) and a wavelength bin code (e.g., D4) fully specifies the LED's key optical performance.

4. Performance Curve Analysis

While specific graphs are not detailed in the provided text, typical electro-optical characteristic curves for such an LED would include:

• I-V (Current-Voltage) Curve: Shows the exponential relationship between forward voltage and current. The curve will have a knee voltage around the typical V_F of 2.0V.
• Luminous Intensity vs. Forward Current: Typically shows a near-linear increase in intensity with current up to the maximum rating, after which efficiency may drop.
• Luminous Intensity vs. Ambient Temperature: Shows the derating of light output as junction temperature increases. For AlGaInP LEDs, output generally decreases with rising temperature.
• Spectral Distribution: A plot showing the relative intensity across wavelengths, peaking at ~591 nm with a ~15 nm FWHM, confirming the brilliant yellow color.
• Forward Voltage vs. Ambient Temperature: Typically shows a negative temperature coefficient, where V_F decreases slightly as temperature rises.

5. Mechanical and Package Information

5.1 Package Dimensions

The LED comes in a standard 17-21 SMD package. Key dimensions (in mm, tolerance ±0.1mm unless noted) are: Length=1.6, Width=0.8, Height=0.6. The package includes a cathode mark for polarity identification during assembly. The exact pad layout (land pattern) is provided to ensure proper solder joint formation and mechanical stability on the PCB.

5.2 Polarity Identification

Correct polarity is essential for operation. The package features a distinct cathode mark. The datasheet provides a clear diagram showing the location of this mark relative to the internal chip and the external pads. Designers must align this with the corresponding footprint on the PCB layout.

6. Soldering and Assembly Guidelines

Adherence to these guidelines is critical for reliability and to prevent damage during the manufacturing process.

6.1 Reflow Soldering Profile

A lead-free (Pb-free) reflow profile is specified:

• Pre-heating: 150°C to 200°C for 60-120 seconds.
• Time Above Liquidus (217°C): 60-150 seconds.
• Peak Temperature: 260°C maximum, held for no more than 10 seconds.
• Heating Rate: Maximum 6°C/second up to 255°C.
• Cooling Rate: Maximum 3°C/second.

Reflow soldering should not be performed more than two times.

6.2 Hand Soldering

If hand soldering is necessary:

• Use a soldering iron with a tip temperature < 350°C.
• Apply heat to each terminal for < 3 seconds.
• Use an iron with a power rating < 25W.
• Allow a minimum 2-second interval between soldering each terminal.
• Exercise extreme caution as hand soldering poses a higher risk of thermal damage.

6.3 Storage and Moisture Sensitivity

The product is packaged in a moisture-resistant bag with desiccant.

• Do not open the bag until ready for use.
• After opening, unused LEDs must be stored at ≤ 30°C and ≤ 60% Relative Humidity.
• The "floor life" after opening is 168 hours (7 days).
• If the floor life is exceeded or the desiccant indicates moisture absorption, a bake-out at 60 ± 5°C for 24 hours is required before reflow.

7. Packaging and Ordering Information

7.1 Tape and Reel Specifications

The LEDs are supplied in 8mm carrier tape on 7-inch diameter reels. Each reel contains 3000 pieces. Detailed dimensions for the carrier tape pockets and the reel are provided to ensure compatibility with automated pick-and-place equipment.

7.2 Label Information

The reel label contains critical information for traceability and correct application:

• CPN: Customer's Product Number.
• P/N: Manufacturer's Product Number (17-21/Y2C-AN1P2/3T).
• QTY: Packing Quantity.
• CAT: Luminous Intensity Rank (e.g., N1, P2).
• HUE: Chromaticity/Dominant Wavelength Rank (e.g., D4, D5).
• REF: Forward Voltage Rank.
• LOT No: Manufacturing Lot Number for traceability.

8. Application Recommendations

8.1 Typical Application Scenarios

• Backlighting: Ideal for dashboard instruments, membrane switches, and symbol illumination due to its wide viewing angle and consistent color.
• Telecommunications: Status indicators and keypad backlighting in phones, fax machines, and networking equipment.
• Consumer Electronics: General status indication, power-on lights, and backlighting for small LCD displays in various portable devices.
• General Purpose Indication: Any application requiring a compact, reliable, bright yellow visual signal.

8.2 Critical Design Considerations

• Current Limiting: An external series resistor is MANDATORY to limit forward current. The LED's V_F has a range (1.7V-2.4V), so the resistor must be calculated for the worst-case (minimum V_F) to prevent overcurrent and burnout. The formula is R = (V_supply - V_F) / I_F.
• Thermal Management: While power dissipation is low, ensuring a good thermal path from the LED pads to the PCB is important for maintaining luminous intensity and longevity, especially in high ambient temperature environments.
• ESD Protection: Implement standard ESD precautions during handling and assembly. Although rated for 2000V HBM, additional circuit protection may be needed in sensitive environments.
• Optical Design: Consider the 140-degree viewing angle when designing light guides, lenses, or diffusers to achieve the desired illumination pattern.

9. Technical Comparison and Differentiation

Compared to older through-hole LED technologies, this SMD LED offers:

• Size Reduction: Drastically smaller footprint and profile, enabling miniaturization.
• Automation Compatibility: Designed for high-speed, automated pick-and-place and reflow soldering, reducing assembly costs.
• Improved Reliability: SMD construction often offers better resistance to vibration and thermal cycling.
• Wider Viewing Angle: The 140-degree viewing angle is typically superior to many traditional LEDs with narrower beams.

Within the SMD LED category, the use of an AIGaInP (Aluminum Gallium Indium Phosphide) chip material for yellow emission generally offers higher efficiency and better temperature stability compared to older technologies like GaAsP.

10. Frequently Asked Questions (FAQs)

Q1: How do I calculate the current-limiting resistor value?
A: Use the formula R = (V_supply - V_F) / I_F. For a 5V supply, using the minimum V_F from the datasheet (1.7V) and a target I_F of 20mA: R = (5 - 1.7) / 0.02 = 165 Ω. Choose the nearest standard value (e.g., 160 Ω or 180 Ω) and verify power rating.

Q2: Can I drive this LED without a resistor if my supply voltage matches the typical V_F (2.0V)?
A: No. The V_F has a range (1.7V-2.4V). A supply of 2.0V could overdrive LEDs with a lower actual V_F. Furthermore, V_F decreases with temperature, creating a risk of thermal runaway. Always use a series resistor.

Q3: What does the "brilliant yellow" color specification mean?
A: It refers to the specific hue of yellow produced by the AIGaInP chip, characterized by a dominant wavelength in the 585-595 nm range. It is a saturated, vivid yellow color.

Q4: Why is there a 7-day limit after opening the moisture-proof bag?
A: SMD packages can absorb moisture from the air. During reflow soldering, this trapped moisture can rapidly expand ("popcorn effect"), causing internal delamination or cracking. The 7-day floor life and baking instructions manage this risk.

11. Design and Usage Case Study

Scenario: Designing a status indicator panel for a portable medical device.
Requirements: Multiple status LEDs (Power, Battery Low, Error), very limited board space, must withstand occasional cleaning, consistent brightness and color across all units.
Implementation with 17-21/Y2C LED:

1. Component Selection: Specify LEDs from a single intensity bin (e.g., P1) and wavelength bin (e.g., D4) to ensure visual consistency.
2. PCB Layout: Utilize the small 1.6x0.8mm footprint to place 3-4 LEDs in a row within a very small area. Follow the recommended land pattern for reliable soldering.
3. Circuit Design: Use a common 3.3V rail. Calculate resistor for each LED: R = (3.3 - 1.7) / 0.02 = 80 Ω (use 82 Ω). Verify resistor power: P = I²R = (0.02)²*82 = 0.033W, so a 0603 or 0402 package resistor is sufficient.
4. Assembly Process: Keep reels sealed until the production line is ready. Follow the exact reflow profile. Perform visual inspection post-solder.
5. Result: A compact, reliable indicator panel with uniform bright yellow signals that meets the space, reliability, and aesthetic requirements.

12. Operating Principle

This LED is a semiconductor photonic device. Its core is a chip made from AIGaInP (Aluminum Gallium Indium Phosphide) materials. When a forward voltage exceeding the diode's junction potential (V_F) is applied, electrons and holes are injected into the active region of the semiconductor. These charge carriers recombine, releasing energy in the form of photons (light). The specific composition of the AIGaInP layers determines the bandgap energy, which directly corresponds to the wavelength (color) of the emitted light—in this case, brilliant yellow (~591 nm). The epoxy resin encapsulant protects the chip, acts as a lens to shape the light output (achieving the 140-degree viewing angle), and may contain phosphors or dyes, though for a water-clear brilliant yellow, it is typically unmodified.

13. Industry Trends and Context

The 17-21 SMD LED represents a mature and widely adopted package standard in the electronics industry. Current trends influencing this product segment include:

• Increased Miniaturization: While 17-21 (1608 metric) remains popular, there is a continuous push towards even smaller packages like 15-21 (1508) and 10-20 (1005) for ultra-compact devices.
• Higher Efficiency: Ongoing improvements in epitaxial growth and chip design aim to deliver higher luminous intensity (mcd) at the same or lower drive currents, improving overall system energy efficiency.
• Enhanced Color Consistency: Tighter binning specifications and advanced manufacturing controls are reducing variation within and across production lots, which is critical for applications requiring uniform appearance.
• Broadening Environmental Compliance: Beyond RoHS and REACH, there is growing attention to full material declarations and reducing the use of other substances of concern throughout the supply chain.
• Integration: A trend towards integrating multiple LED chips (RGB, or multiple monochrome) into a single package, or combining the LED with driver ICs, is observed for more advanced lighting and signaling solutions, though simple discrete LEDs like this one remain fundamental for basic indicator functions.

This LED, with its standard package, proven AIGaInP technology, and comprehensive compliance, is well-positioned within these trends as a reliable, general-purpose component.