SMD LED 15-21/B6C-ZQ1R1N/2T Datasheet - Blue - 2.0x1.25x0.8mm - 3.7V Max - 40mW - English Technical Document

1. Product Overview

The 15-21/B6C-ZQ1R1N/2T is a compact, surface-mount blue LED designed for modern electronic applications requiring high-density component placement and reliable performance. This device utilizes InGaN chip technology to produce a blue emission with a typical peak wavelength of 468 nm. Its miniature footprint and lightweight construction make it an ideal choice for space-constrained designs.

1.1 Core Advantages

The primary advantage of this LED is its significantly reduced size compared to traditional lead-frame type components. This enables smaller printed circuit board (PCB) designs, higher packing density, reduced storage space requirements, and ultimately, the development of more compact end-user equipment. Its compatibility with standard automated placement and soldering processes further enhances its suitability for high-volume manufacturing.

1.2 Target Market and Applications

This LED is targeted at a broad range of consumer, industrial, and telecommunications applications. Typical use cases include backlighting for instrument panels, switches, and symbols; indicator and backlighting functions in telecommunication devices such as telephones and fax machines; flat backlighting for LCDs; and general-purpose indicator applications.

2. Technical Specifications and In-Depth Interpretation

This section provides a detailed analysis of the device's electrical, optical, and thermal characteristics.

2.1 Absolute Maximum Ratings

The absolute maximum ratings define the stress limits beyond which permanent damage to the device may occur. These are not intended for normal operation.

• Reverse Voltage (VR): 5 V. Exceeding this voltage in reverse bias can cause junction breakdown.
• Forward Current (IF): 20 mA. This is the maximum continuous DC forward current.
• Peak Forward Current (IFP): 40 mA. This rating applies under pulsed conditions with a duty cycle of 1/10 at 1 kHz.
• Power Dissipation (Pd): 40 mW. This is the maximum power the package can dissipate at an ambient temperature of 25°C. Derating is necessary at higher temperatures.
• Operating Temperature (Topr): -40°C to +85°C. The device is guaranteed to function within this ambient temperature range.
• Storage Temperature (Tstg): -40°C to +90°C.
• Soldering Temperature (Tsol): For reflow soldering, a peak temperature of 260°C for a maximum of 10 seconds is specified. For hand soldering, the iron tip temperature should not exceed 350°C for a maximum of 3 seconds per terminal.

2.2 Electro-Optical Characteristics

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

• Luminous Intensity (Iv): Ranges from a minimum of 72.0 mcd to a maximum of 140.0 mcd, with a typical tolerance of ±11%. The actual value is determined by the bin code (Q1, Q2, R1).
• Viewing Angle (2θ1/2): Typically 130 degrees. This wide viewing angle makes the LED suitable for applications requiring broad illumination.
• Peak Wavelength (λp): Typically 468 nm.
• Dominant Wavelength (λd): Ranges from 465.0 nm to 475.0 nm, with a tolerance of ±1 nm. The specific bin is coded as X (465-470 nm) or Y (470-475 nm).
• Spectral Bandwidth (Δλ): Typically 25 nm, measured at half the peak intensity (FWHM).
• Forward Voltage (VF): Ranges from 2.70 V to 3.70 V at 20 mA, with a tolerance of ±0.1V. The specific bin is coded from 10 (2.7-2.9V) to 14 (3.5-3.7V).
• Reverse Current (IR): Maximum of 50 μA when a reverse voltage (VR) of 5V is applied. It is important to note that the device is not designed for operation in reverse bias; this parameter is for leakage current testing only.

2.3 Thermal Characteristics

While not explicitly listed in a separate table, thermal management is critical. The power dissipation rating of 40 mW and the operating temperature range define the thermal limits. Designers must ensure adequate PCB layout and, if necessary, thermal vias or heatsinking to maintain the junction temperature within safe limits, especially when operating at high ambient temperatures or near maximum current.

3. Binning System Explanation

The product is sorted into bins based on key performance parameters to ensure consistency within a production lot. This allows designers to select LEDs that meet specific application requirements.

3.1 Luminous Intensity Binning

Luminous intensity is categorized into three bins:
- Q1: 72.0 - 90.0 mcd
- Q2: 90.0 - 112.0 mcd
- R1: 112.0 - 140.0 mcd

3.2 Dominant Wavelength Binning

The color (dominant wavelength) is sorted into two bins:
- X: 465.0 - 470.0 nm
- Y: 470.0 - 475.0 nm

3.3 Forward Voltage Binning

Forward voltage is sorted into five bins to aid in current regulation circuit design:
- 10: 2.7 - 2.9 V
- 11: 2.9 - 3.1 V
- 12: 3.1 - 3.3 V
- 13: 3.3 - 3.5 V
- 14: 3.5 - 3.7 V

4. Performance Curve Analysis

The datasheet includes several typical characteristic curves that illustrate device behavior under varying conditions.

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

This curve shows the exponential relationship between forward voltage and current. It is crucial for selecting the appropriate current-limiting resistor. The curve typically shows that a small increase in voltage beyond the turn-on point results in a large increase in current, highlighting the necessity of current regulation.

4.2 Relative Luminous Intensity vs. Forward Current

This graph demonstrates how light output increases with forward current. It is generally linear over a range but will saturate at higher currents due to thermal and efficiency effects. Operating near the maximum rated current may not yield proportional increases in brightness and will reduce device lifetime.

4.3 Relative Luminous Intensity vs. Ambient Temperature

This curve shows the derating of light output as ambient temperature increases. Luminous intensity typically decreases as temperature rises. For reliable performance, thermal management must be considered in the application design.

4.4 Spectrum Distribution

The spectral plot shows the emission profile centered around the peak wavelength of 468 nm with a typical FWHM of 25 nm. This information is vital for color-sensitive applications.

4.5 Radiation Pattern

The radiation diagram illustrates the spatial distribution of light intensity, confirming the typical 130-degree viewing angle. The pattern is typically lambertian or near-lambertian for this type of package.

5. Mechanical and Package Information

5.1 Package Dimensions

The 15-21 SMD LED has a compact footprint. Key dimensions (in mm, tolerance ±0.1mm unless noted) include a body length of 2.0 mm, a width of 1.25 mm, and a height of 0.8 mm. The detailed drawing specifies pad spacing and overall outlines for PCB land pattern design.

5.2 Polarity Identification

The cathode is clearly marked on the package. Correct polarity must be observed during assembly to prevent device damage.

6. Soldering and Assembly Guidelines

6.1 Reflow Soldering Profile

The device is compatible with infrared and vapor phase reflow processes. A lead-free soldering profile is recommended:
- Preheat: 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.
- Maximum heating rate: 6°C/sec, maximum cooling rate: 3°C/sec.
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 below 350°C. Contact time per terminal should not exceed 3 seconds, with an interval of at least 2 seconds between soldering each terminal. The soldering iron power should be 25W or less to avoid thermal shock.

6.3 Storage and Moisture Sensitivity

The LEDs are packaged in moisture-resistant barrier bags with desiccant.
- Do not open the bag until ready for use.
- After opening, unused LEDs should be stored at ≤30°C and ≤60% RH.
- The "floor life" after bag opening is 168 hours (7 days).
- If the floor life is exceeded or the desiccant indicates moisture ingress, a bake-out at 60±5°C for 24 hours is required before use.

7. Packaging and Ordering Information

7.1 Packaging Specifications

The LEDs are supplied on 8mm wide embossed carrier tape, wound onto 7-inch diameter reels. Each reel contains 2000 pieces. Detailed reel and carrier tape dimensions are provided for automated feeder setup.

7.2 Label Information

The reel label contains critical information for traceability and identification: Customer Product Number (CPN), Product Number (P/N), Packing Quantity (QTY), and the specific bin codes for Luminous Intensity (CAT), Dominant Wavelength (HUE), and Forward Voltage (REF), along with the Lot Number.

8. Application Notes and Design Considerations

8.1 Current Limiting

Critical: An external current-limiting resistor must always be used in series with the LED. The forward voltage has a negative temperature coefficient and production tolerance. A direct connection to a voltage source, even slightly above the typical VF, can cause a large, uncontrolled current surge leading to immediate failure.

8.2 PCB Layout

Ensure the PCB land pattern matches the recommended footprint. Provide adequate copper area for heat dissipation, especially when operating at high currents or in high ambient temperatures. Avoid mechanical stress on the LED body during and after soldering.

8.3 ESD Precautions

The device has an ESD sensitivity rating of 150V (Human Body Model). Standard ESD handling precautions should be followed during assembly and handling.

9. Compliance and Environmental Information

The product is compliant with key environmental regulations:
- RoHS: The product is lead-free and complies with the Restriction of Hazardous Substances directive.
- REACH: Compliant with the EU's Registration, Evaluation, Authorisation and Restriction of Chemicals regulation.
- Halogen-Free: Compliant with halogen-free requirements (Bromine <900 ppm, Chlorine <900 ppm, Br+Cl <1500 ppm).

10. Frequently Asked Questions (FAQ)

10.1 Why did my LED fail immediately upon power-up?

The most common cause is the absence of a series current-limiting resistor. LEDs are current-driven devices. Connecting them directly to a voltage source causes excessive current flow. Always use a resistor calculated based on the supply voltage, the LED's forward voltage (use the maximum bin value for safety), and the desired operating current.

10.2 Can I use this LED outdoors?

The operating temperature range is -40°C to +85°C, which covers many outdoor conditions. However, the primary limitation for outdoor use is often the package's resistance to moisture and UV radiation, which is not specified for this standard commercial-grade component. For harsh environments, consider devices specifically rated for outdoor or automotive use.

10.3 How do I interpret the bin codes on the label?

The bin codes (e.g., ZQ1R1N) correspond to the specific performance sorting. "Q1" indicates the luminous intensity bin (72-90 mcd), "R1" is part of the internal product code, and "N" may relate to other characteristics. The label fields CAT, HUE, and REF explicitly state the Luminous Intensity, Dominant Wavelength, and Forward Voltage bins, respectively.

10.4 Is repair/rework allowed after soldering?

Repair is not recommended. If absolutely necessary, use a dual-head soldering iron to simultaneously heat both terminals to avoid mechanical stress on the solder joints or the LED body. Always verify that the LED's characteristics have not been degraded after any rework.

11. Design and Usage Case Study

11.1 Designing a Status Indicator Panel

Consider a control panel requiring multiple blue status indicators. Using the 15-21 LED, designers can achieve high-density layouts. For a 5V system, a series resistor value is calculated. Using the maximum VF from bin 14 (3.7V) and a target current of 15 mA (below the 20 mA max for longer life), the resistor value is R = (5V - 3.7V) / 0.015A ≈ 87 ohms. A standard 91-ohm or 100-ohm resistor would be suitable. The wide 130-degree viewing angle ensures visibility from various angles. The moisture sensitivity procedures must be followed during assembly if the PCBs are not soldered immediately after bag opening.

12. Technical Principle Introduction

This LED is based on an Indium Gallium Nitride (InGaN) semiconductor chip. When a forward voltage is applied, electrons and holes recombine in the active region of the semiconductor, releasing energy in the form of photons. The specific composition of the InGaN alloy determines the bandgap energy, which in turn defines the wavelength of the emitted light—in this case, blue. The chip is encapsulated in a clear resin lens which protects the die, provides mechanical stability, and shapes the light output beam.

13. Industry Trends and Context

The 15-21 package represents a mature form factor in the SMD LED market. Current industry trends are driving towards even smaller packages (e.g., 0402, 0201 metric sizes) for ultra-miniaturization, higher efficiency (more lumens per watt), and improved color consistency (tighter binning). There is also a strong focus on enhanced reliability under higher temperature and humidity conditions for automotive and industrial applications. This device fits well into applications where a proven, cost-effective, and readily available blue light source is required, balancing size, performance, and ease of manufacturing.