SMD Middle Power LED 67-22ST Datasheet - PLCC-2 Package - 2.0x1.6x0.7mm - 1.8-2.7V - 150mA - Far Red (720-750nm) - English Technical Document

1. Product Overview

This document details the technical specifications for a surface-mount device (SMD) Middle Power LED encapsulated in a PLCC-2 package. The device emits light in the Far Red spectrum, utilizing AlGaInP chip technology. It is designed for applications requiring efficient, compact light sources with a wide viewing angle.

1.1 Core Features and Advantages

The primary advantages of this LED include its high efficacy and middle power consumption profile, making it suitable for a balance between performance and thermal management. The package offers a wide viewing angle of 120 degrees, ensuring broad light distribution. It is constructed with environmentally friendly materials, being Pb-free, compliant with RoHS, EU REACH, and halogen-free standards (Br<900ppm, Cl<900ppm, Br+Cl<1500ppm). The product also follows ANSI binning standards for consistent performance categorization.

1.2 Target Applications and Markets

This LED is engineered for specific lighting applications that benefit from Far Red wavelengths. Its primary use cases include decorative and entertainment lighting, where specific color effects are desired. A significant application is in agriculture lighting, particularly horticulture, as Far Red light (720-750nm) plays a crucial role in plant photomorphogenesis, influencing processes like seed germination, stem elongation, and flowering. It is also suitable for general lighting use where its specific spectral output is applicable.

2. Technical Specifications and In-Depth Interpretation

2.1 Absolute Maximum Ratings

These ratings define the limits beyond which permanent damage to the device may occur. They are specified at a soldering point temperature (T_Soldering) of 25°C.

• Forward Current (I_F): 150 mA - The maximum continuous DC current recommended for reliable operation.
• Peak Forward Current (I_FP): 300 mA - Applicable only under pulsed conditions with a duty cycle of 1/10 and a pulse width of 10ms. Exceeding the continuous current rating even briefly can degrade the LED.
• Power Dissipation (P_d): 405 mW - The maximum power the package can dissipate, calculated from V_F * I_F and thermal limits.
• Operating Temperature (T_opr): -40°C to +85°C - The ambient temperature range for normal operation.
• Storage Temperature (T_stg): -40°C to +100°C.
• Thermal Resistance (R_{th J-S}): 50 °C/W - This critical parameter defines the temperature rise from the semiconductor junction to the soldering point per watt of power dissipated. A lower value indicates better heat transfer out of the chip.
• Junction Temperature (T_j): 115 °C - The maximum allowable temperature at the semiconductor junction itself.
• Soldering Temperature: The device can withstand reflow soldering at 260°C for 10 seconds or hand soldering at 350°C for 3 seconds. It is sensitive to electrostatic discharge (ESD), requiring proper handling procedures.

2.2 Electro-Optical Characteristics

These are typical performance parameters measured at T_Soldering = 25°C and I_F = 150mA, unless otherwise stated.

• Radiometric Power (Φ_e): 80 to 160 mW - The total radiant flux (optical power) emitted. The tolerance is ±11%.
• Forward Voltage (V_F): 1.8 to 2.7 V - The voltage drop across the LED at the specified current. The tolerance is ±0.1V. Lower V_F at a given current generally indicates higher electrical efficiency.
• Viewing Angle (2θ_1/2): 120 degrees - The full angle at which the luminous intensity is half of the maximum intensity (on-axis).
• Reverse Current (I_R): 10 µA (max) at V_R = 5V - LEDs are not designed for reverse bias; this parameter indicates leakage.

3. Binning System Explanation

The product is sorted into bins to ensure consistency. Designers must select appropriate bins for their application requirements.

3.1 Radiometric Power Binning

Binned at I_F=150mA. Codes C1 through C4 represent increasing output power ranges (e.g., C1: 80-100mW, C4: 140-160mW). The ±11% tolerance applies within each bin.

3.2 Forward Voltage Binning

Binned at I_F=150mA. Codes 25 through 33 represent voltage ranges in 0.1V steps from 1.8-1.9V (Bin 25) to 2.6-2.7V (Bin 33). The ±0.1V tolerance applies. Selecting LEDs from a tight voltage bin can simplify driver design for multi-LED arrays.

3.3 Peak Wavelength Binning

Binned at I_F=150mA. This defines the spectral output:

• FA3: 720 - 730 nm
• FA4: 730 - 740 nm
• FA5: 740 - 750 nm

The dominant/peak wavelength measurement tolerance is ±1nm. This precise binning is crucial for applications like horticulture where specific photon wavelengths trigger different plant responses.

4. Performance Curve Analysis

4.1 Spectrum Distribution

The provided spectrum graph shows a typical emission curve for an AlGaInP Far Red LED. The peak is within the binned range (720-750nm), with a relatively narrow spectral bandwidth (full width at half maximum - FWHM) characteristic of this semiconductor material, ensuring color purity.

4.2 Forward Voltage vs. Junction Temperature (Fig.1)

This curve shows that the forward voltage (V_F) has a negative temperature coefficient. As the junction temperature (T_j) increases from 25°C to 115°C, V_F decreases. This is a fundamental property of semiconductor diodes. For constant-current drivers, this is not a major concern, but it must be considered in thermal design and for circuits sensing V_F as a proxy for T_j.

4.3 Relative Radiometric Power vs. Forward Current (Fig.2)

The optical output is sub-linear with current. While output increases with current, the efficacy (mW/mA) typically decreases at higher currents due to increased heat and efficiency droop. Operating significantly below the maximum current (e.g., at 100mA instead of 150mA) can improve efficacy and longevity.

4.4 Relative Luminous Intensity vs. Junction Temperature (Fig.3)

This graph demonstrates thermal quenching. As T_j rises, the radiant output decreases. Maintaining a low junction temperature through effective thermal management (e.g., using a PCB with good thermal vias and a heatsink) is critical for maintaining stable light output and long lifetime.

4.5 Forward Current vs. Forward Voltage (Fig.4)

This is the classic I-V curve for a diode, showing the exponential relationship. The curve shifts with temperature (as seen in Fig.1). The graph provided is at T_S=25°C.

4.6 Maximum Driving Current vs. Soldering Temperature (Fig.5)

This derating curve is essential for reliability. It shows that the maximum allowable forward current must be reduced if the temperature at the soldering point (and by extension, the junction) increases. For example, if the soldering point reaches 100°C, the maximum continuous current is significantly less than 150mA. This graph is based on the given R_{th J-S} of 50°C/W.

4.7 Radiation Diagram (Fig.6)

The polar plot visualizes the 120-degree viewing angle, showing the relative intensity at different angles from 0° (on-axis) to 90°. The pattern appears Lambertian or near-Lambertian, which is common for this package type with a water-clear resin dome.

5. Mechanical and Package Information

5.1 Package Dimensions

The PLCC-2 package has nominal dimensions of 2.0mm (length) x 1.6mm (width) x 0.7mm (height). The dimensional drawing specifies key features including the anode and cathode pad locations, the lens, and mechanical tolerances (typically ±0.1mm unless otherwise noted). The chip is mounted in a reflector cup.

5.2 Polarity Identification

The package has a marked cathode (typically indicated by a green tint on the cathode pad, a notch, or a chamfer on that side of the package). Correct polarity is essential during assembly to prevent damage.

6. Soldering and Assembly Guidelines

6.1 Reflow Soldering Parameters

The device is rated for a maximum of 260°C for 10 seconds during reflow soldering. It is critical to follow a profile that preheats adequately to minimize thermal shock, reaches the necessary peak temperature for solder reflow, and cools at a controlled rate. The specific time above liquidus (TAL) should be controlled according to the solder paste manufacturer's specifications.

6.2 Hand Soldering

If hand soldering is necessary, the iron tip temperature must not exceed 350°C, and contact time should be limited to 3 seconds per pad. Use a low-power iron (e.g., 30W) with a fine tip. Apply heat to the PCB pad, not directly to the LED body, and then introduce solder.

6.3 Storage and Handling

The components are sensitive to moisture (MSL rating implied by the moisture-resistant packing). If the protective bag is opened or the exposure time limit is exceeded, baking is required before reflow to prevent \"popcorning\" damage. Always handle with ESD precautions.

7. Packaging and Ordering Information

7.1 Reel and Tape Specifications

The LEDs are supplied on embossed carrier tape wound onto reels. The reel dimensions, pocket spacing (pitch), and tape width are specified to be compatible with standard SMD pick-and-place equipment. Each reel contains 4000 pieces.

7.2 Moisture-Resistant Packing

The reels are sealed inside an aluminum moisture-proof bag with desiccant to maintain a dry environment and meet the Moisture Sensitivity Level (MSL) requirements.

7.3 Label Explanation

The reel label contains key information: Customer's Product Number (CPN), Product Number (P/N), Packing Quantity (QTY), and the specific bin codes for Luminous Intensity Rank (CAT), Dominant Wavelength Rank (HUE), and Forward Voltage Rank (REF), along with the Lot Number (LOT No).

8. Application Suggestions and Design Considerations

8.1 Thermal Management

Given the R_{th J-S} of 50°C/W, effective heat sinking is non-negotiable for reliable operation at full current. Use a PCB with a dedicated thermal pad connected to the LED's thermal path (often the cathode pad) and employ thermal vias to transfer heat to internal ground planes or an external heatsink. The derating curve (Fig.5) must be used to determine the maximum safe operating current for your specific board's thermal resistance.

8.2 Electrical Drive

Always drive LEDs with a constant current source, not a constant voltage. This ensures stable light output and protects the LED from thermal runaway. The driver should be rated for the forward voltage range of the selected bin (1.8-2.7V) at the desired operating current. Consider implementing pulse-width modulation (PWM) for dimming to avoid color shift that can occur with analog (current reduction) dimming.

8.3 Optical Integration

The wide 120-degree viewing angle may require secondary optics (lenses, reflectors) if a more focused beam is needed. The water-clear resin allows for high light extraction. For horticulture applications, ensure the fixture design provides uniform Far Red photon flux across the target area, often in combination with other wavelengths (e.g., deep red 660nm, blue).

9. Reliability and Quality Assurance

The datasheet lists a comprehensive set of reliability tests performed with a 90% confidence level and 10% Lot Tolerance Percent Defective (LTPD). Tests include:

• Resistance to Solder Heat (260°C/10s, 3x)
• Temperature Cycling (-40°C to +100°C)
• High Temperature/Humidity Life (85°C/85% RH, 1000hrs)
• High/Low Temperature Storage and Operating Life tests
• Pulse and Thermal Shock tests

These tests validate the robustness of the package construction, wire bonds, and semiconductor integrity under various environmental stresses.

10. Technical Principles and Trends

10.1 Operating Principle

This LED is based on an Aluminum Gallium Indium Phosphide (AlGaInP) semiconductor. When a forward voltage is applied, electrons and holes recombine in the active region, releasing energy in the form of photons. The specific bandgap energy of the AlGaInP alloy determines the emitted wavelength, in this case, in the 720-750nm Far Red range. The PLCC-2 package provides environmental protection, a primary lens for light extraction, and a thermal path.

10.2 Industry Context and Trends

Middle Power LEDs like this one fill a niche between low-power indicator LEDs and high-power illumination LEDs. They offer a good compromise between cost, efficacy (lm/W or mW/W), and ease of thermal management. The demand for Far Red LEDs has grown significantly with the expansion of controlled environment agriculture (CEA) and horticultural lighting, where specific light recipes are used to optimize plant growth, yield, and quality. Research continues into improving the external quantum efficiency (EQE) and reliability of AlGaInP LEDs, particularly in managing efficiency droop and maintaining performance at elevated temperatures.