SMD LED 15-21/G6C-FP1Q1L/2T Specification - 1.6x0.8x0.6mm - 2.0V Typ - 25mA - Brilliant Yellow Green - English Technical Document

1. Product Overview

The 15-21/G6C-FP1Q1L/2T is a surface-mount device (SMD) LED designed for modern, compact electronic applications. This component represents a significant advancement over traditional lead-frame LEDs, offering a substantial reduction in footprint and weight. Its primary function is to provide a reliable and efficient light source in a miniature package, enabling higher packing density on printed circuit boards (PCBs) and contributing to the overall miniaturization of electronic equipment. The "G6C" designation in the part number indicates the specific Brilliant Yellow Green color produced by the AlGaInP (Aluminum Gallium Indium Phosphide) semiconductor material housed within a water-clear resin lens.

The core advantages of this LED stem from its SMD construction. The elimination of leads reduces parasitic inductance and allows for automated pick-and-place assembly, streamlining high-volume manufacturing processes. Its small size, approximately 1.6mm x 0.8mm x 0.6mm, directly translates to reduced storage space requirements and enables the design of slimmer end products. Furthermore, the product is compliant with key environmental and safety regulations, being Pb-free, RoHS compliant, REACH compliant, and halogen-free, meeting the stringent requirements of the global electronics market.

2. In-Depth Technical Parameter Analysis

The performance and limitations of the LED are defined by its electrical, optical, and thermal specifications. A thorough understanding of these parameters is crucial for reliable circuit design and ensuring long-term performance.

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.

• Reverse Voltage (VR): 5V. Exceeding this voltage in reverse bias can cause junction breakdown.
• Continuous Forward Current (IF): 25mA. This is the maximum DC current recommended for continuous operation at 25°C.
• Peak Forward Current (IFP): 60mA. This current is permissible only under pulsed conditions (duty cycle 1/10 at 1kHz), allowing for brief periods of higher brightness.
• Power Dissipation (Pd): 60mW. This is the maximum power the package can dissipate as heat, calculated as VF * IF.
• Electrostatic Discharge (ESD): 2000V (Human Body Model). This rating indicates a moderate level of ESD sensitivity; proper handling procedures are necessary.
• Operating & Storage Temperature: -40°C to +85°C (operating), -40°C to +90°C (storage). This wide range makes it suitable for various environmental conditions.
• Soldering Temperature: Withstands reflow soldering at 260°C for 10 seconds or hand soldering at 350°C for 3 seconds per terminal.

2.2 Electro-Optical Characteristics

These are the typical performance parameters measured at a forward current (IF) of 20mA and an ambient temperature (Ta) of 25°C.

• Luminous Intensity (Iv): Ranges from 45.0 mcd (min) to 90.0 mcd (max), with a typical tolerance of ±11%. This defines the perceived brightness.
• Viewing Angle (2θ1/2): 130 degrees (typical). This wide angle provides a broad emission pattern, suitable for area illumination and indicator applications.
• Peak Wavelength (λp): 575 nm (typical). The wavelength at which the spectral power distribution is maximum.
• Dominant Wavelength (λd): Ranges from 570.0 nm to 574.5 nm. This is the single wavelength perceived by the human eye, defining the color hue (Brilliant Yellow Green). Tolerance is ±1nm.
• Spectral Bandwidth (Δλ): 20 nm (typical). The width of the emitted spectrum at half the maximum intensity.
• Forward Voltage (VF): Ranges from 1.70V to 2.30V at 20mA, with a typical tolerance of ±0.05V. This is the voltage drop across the LED when conducting.
• Reverse Current (IR): Maximum 10 μA at VR=5V. The device is not designed for reverse operation; this parameter is for leakage test purposes only.

3. Binning System Explanation

Due to inherent variations in semiconductor manufacturing, LEDs are sorted into performance bins. This system allows designers to select components that meet specific consistency requirements for their application.

3.1 Luminous Intensity Binning

LEDs are categorized into three bins (P1, P2, Q1) based on their measured luminous intensity at 20mA. For example, bin Q1 contains LEDs with intensity between 72.0 and 90.0 mcd. Selecting a single bin ensures uniform brightness across multiple LEDs in an array.

3.2 Dominant Wavelength Binning

To maintain consistent color, LEDs are binned by dominant wavelength into three groups (CC2, CC3, CC4), each covering a 1.5 nm range from 570.0 nm to 574.5 nm. This tight control is essential for applications where color matching is critical.

3.3 Forward Voltage Binning

Forward voltage is sorted into six bins (19 to 24), each representing a 0.1V step from 1.70V to 2.30V. Knowledge of the VF bin is important for designing efficient current-limiting circuits, especially when driving multiple LEDs in series, to ensure uniform current distribution.

4. Performance Curve Analysis

While the datasheet references typical electro-optical characteristic curves, these graphs are essential for understanding device behavior under non-standard conditions. Designers should anticipate the following relationships based on semiconductor physics:

• IV Curve (Current vs. Voltage): The forward current increases exponentially with forward voltage after exceeding the turn-on voltage (~1.7V). This underscores the critical need for a current-limiting device (resistor or driver).
• Luminous Intensity vs. Current: Intensity generally increases with current but may saturate or become less efficient at very high currents due to thermal effects and droop.
• Luminous Intensity vs. Temperature: The light output typically decreases as the junction temperature rises. This thermal derating must be considered in high-temperature environments or high-power applications.
• Spectral Shift vs. Temperature: The dominant wavelength may shift slightly with temperature, which can affect color perception in precision applications.

5. Mechanical and Package Information

5.1 Package Dimensions

The LED has a compact rectangular footprint. Key dimensions (in mm) include a body length of 1.6, width of 0.8, and height of 0.6. The solder pads are designed for reliable surface mounting. A cathode mark is clearly indicated on the package to ensure correct polarity orientation during assembly. All unspecified tolerances are ±0.1mm.

5.2 Packaging for Automated Assembly

The components are supplied in moisture-resistant packaging to prevent damage from ambient humidity. They are delivered on 8mm wide carrier tape wound onto 7-inch diameter reels, with 2000 pieces per reel. This format is fully compatible with standard automatic placement equipment. The reel and tape dimensions are specified to ensure compatibility with feeder systems.

6. Soldering and Assembly Guidelines

Proper handling is critical to prevent damage and ensure reliability.

6.1 Storage and Moisture Sensitivity

The LEDs are moisture-sensitive (MSL). The moisture-proof bag must not be opened until ready for use. After opening, unused components must be stored at ≤30°C and ≤60% RH and used within 168 hours (7 days). If exceeded, a baking treatment at 60±5°C for 24 hours is required before use.

6.2 Reflow Soldering Profile

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

• Pre-heating: 150-200°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/sec.
• Cooling rate: Maximum 3°C/sec.

Reflow soldering should not be performed more than twice. Stress on the LED body during heating and board warpage after soldering must be avoided.

6.3 Hand Soldering and Rework

If hand soldering is necessary, the iron tip temperature must be below 350°C, applied for no more than 3 seconds per terminal, using a low-power iron (<25W). A cooling interval of >2 seconds between terminals is required. Rework is strongly discouraged. If unavoidable, a dual-head soldering iron must be used to simultaneously heat both terminals, preventing mechanical stress on the solder joints. The impact of rework on device characteristics must be verified beforehand.

7. Packaging and Ordering Information

The labeling on the reel and bag provides critical traceability and specification data. Key fields include:

• P/N: Product Number (15-21/G6C-FP1Q1L/2T).
• CAT: Luminous Intensity Rank (e.g., Q1).
• HUE: Dominant Wavelength/Chromaticity Rank (e.g., CC4).
• REF: Forward Voltage Rank (e.g., 21).
• LOT No: Manufacturing Lot Number for traceability.

The part number itself encodes the key bins: FP1 (Intensity), Q1 (Intensity sub-bin), L (Wavelength), 2T (Voltage).

8. Application Recommendations

8.1 Typical Application Scenarios

• Backlighting: Ideal for dashboard indicators, switch illumination, and flat backlighting for LCDs and symbols due to its wide viewing angle and uniform light output.
• Telecommunication Equipment: Status indicators and keypad backlighting in phones and fax machines.
• General Indicator Use: Power status, signal alerts, and decorative lighting in consumer electronics.

8.2 Critical Design Considerations

• Current Limiting is Mandatory: An external series resistor or constant-current driver MUST be used. The exponential IV characteristic means a small voltage change causes a large current change, leading to rapid failure.
• Thermal Management: Ensure the PCB design allows for adequate heat dissipation, especially when operating near the maximum current or in high ambient temperatures, to prevent luminous output degradation and shortened lifespan.
• ESD Protection: Implement ESD safeguards during handling and assembly, and consider circuit-level protection if the LED is exposed to user interfaces.

9. Technical Comparison and Differentiation

Compared to older through-hole LEDs, this SMD type offers superior performance in modern electronics:

• Size & Density: Drastically smaller, enabling higher component density.
• Assembly Cost: Enables fully automated, high-speed assembly, reducing manufacturing costs.
• Performance: Typically offers better reliability and more consistent optical characteristics due to automated manufacturing processes.
• Regulatory Compliance: Built to meet contemporary environmental standards (Pb-free, Halogen-free, RoHS, REACH), which may be a challenge for older component types.

Its primary trade-off is the requirement for more precise PCB soldering processes compared to through-hole components.

10. Frequently Asked Questions (FAQs)

10.1 Why is a current-limiting resistor absolutely necessary?

The LED's forward voltage has a negative temperature coefficient and a manufacturing tolerance. Without a fixed current source (like a resistor), the operating point is unstable. A slight increase in voltage or temperature can cause a runaway increase in current, exceeding the Absolute Maximum Rating and destroying the device instantly.

10.2 Can I drive this LED directly from a 3.3V or 5V logic supply?

No, not directly. You must use a series resistor. The resistor value (R) is calculated using Ohm's Law: R = (V_supply - VF_LED) / I_desired. For example, with a 3.3V supply, a VF of 2.0V, and a desired current of 20mA: R = (3.3 - 2.0) / 0.02 = 65 Ohms. A standard 68 Ohm resistor would be appropriate.

10.3 What do the bin codes (P1, CC4, 21) mean for my design?

They define the performance spread. For a single indicator, any bin may suffice. For an array where uniform brightness and color are critical (e.g., a backlight), you must specify and use LEDs from the same luminous intensity (CAT) and dominant wavelength (HUE) bins. Voltage bin (REF) is less critical for visual performance but important for power supply design in series strings.

10.4 How critical is the 7-day floor life after opening the moisture barrier bag?

Very critical for reflow soldering. Absorbed moisture can vaporize during the high-temperature reflow cycle, causing internal delamination or "popcorning," which cracks the package and leads to failure. If the exposure time is exceeded, baking is required to drive out the moisture.

11. Practical Design and Usage Case

Scenario: Designing a multi-LED status indicator panel.

1. Specification: 10 LEDs need to indicate different system states. Uniform brightness and color are important for aesthetics.
2. Component Selection: Order all LEDs from the same CAT (e.g., Q1) and HUE (e.g., CC4) bins to guarantee consistency.
3. Circuit Design: Use a 5V rail. Assuming a typical VF of 2.0V from bin 20 and a target current of 20mA, calculate the series resistor: R = (5V - 2.0V) / 0.02A = 150 Ohms. Use ten independent 150-ohm resistors, one in series with each LED, connected between the LED cathode and ground. Drive the anodes from microcontroller GPIO pins.
4. PCB Layout: Place LEDs with consistent orientation (cathode mark). Ensure adequate spacing for heat dissipation. Follow the recommended solder pad geometry from the package dimension drawing.
5. Assembly: Keep components in sealed bags until the production line is ready. Follow the exact reflow profile. Inspect after soldering for proper alignment and solder joints.

This approach ensures reliable operation, consistent appearance, and long-term stability.

12. Operational Principle

This LED is a semiconductor photonic device. Its core is a chip made of AlGaInP (Aluminum Gallium Indium Phosphide) materials. When a forward voltage exceeding the diode's turn-on voltage (~1.7V) is applied, electrons and holes are injected into the active region of the semiconductor junction. These charge carriers recombine, releasing energy in the form of photons (light particles). The specific composition of the AlGaInP alloy determines the bandgap energy, which directly dictates the wavelength (color) of the emitted light—in this case, Brilliant Yellow Green (~575 nm). The water-clear epoxy resin encapsulant protects the chip, acts as a lens to shape the light output into a 130-degree viewing angle, and enhances light extraction from the semiconductor material.

13. Technology Trends and Context

The 15-21 SMD LED exists within the broader trend of electronics miniaturization and performance optimization. The shift from through-hole to surface-mount technology (SMT) for passive and active components, including LEDs, has been a dominant driver for decades, enabling the devices we use today. Key ongoing trends relevant to such components include:

• Increased Efficiency: Ongoing material science research aims to improve the lumens-per-watt (efficacy) of LEDs, reducing power consumption for the same light output.
• Enhanced Color Rendering & Consistency: Advances in phosphor technology and binning processes allow for tighter control over color point and spectrum, critical for displays and lighting.
• Integration: The trend towards placing driver circuitry, protection components, and multiple LED chips into a single package (e.g., LED modules or IC-leds) to simplify design and save board space.
• Smart & Connected Features: For lighting applications, integration of control interfaces (e.g., DALI, Zigbee) directly into LED packages is growing.
• Sustainability: The drive for halogen-free, Pb-free, and energy-efficient components continues to be a major regulatory and market force, as evidenced by this product's compliance listings.

While a basic indicator LED, the 15-21's specifications reflect the current industry standards for reliability, environmental compliance, and manufacturability required in a global supply chain.