SMD Reflector LED 67-21 Series Datasheet - P-LCC-2 Package - 3.5V Max - 110mW - Green/Yellow/Blue/Orange - English Technical Document

1. Product Overview

The 67-21 series represents a family of surface-mount device (SMD) light-emitting diodes (LEDs) featuring an integrated reflector within a P-LCC-2 package. This design is engineered to provide a wide viewing angle and optimized light output, making it particularly suitable for applications requiring efficient light coupling into light guides or pipes. The series is available in multiple colors including soft orange, green, blue, and yellow, with a white package body and a colorless clear window. Its low forward current requirement makes it an ideal choice for power-sensitive applications such as portable electronic devices.

1.1 Core Advantages and Target Market

The primary advantages of this LED series stem from its package design. The integrated inter-reflector significantly enhances light extraction and directionality, resulting in a consistent and broad emission pattern. This characteristic is crucial for backlighting symbols, switches, and LCD panels where uniform illumination is required. The device is fully compatible with standard automated pick-and-place equipment and is supplied on 8mm tape and reel for high-volume assembly. Its compatibility with various soldering processes, including vapor-phase reflow, infrared reflow, and wave soldering, offers flexibility in manufacturing. The product is also RoHS compliant and lead-free. Target markets include automotive interiors (dashboard and switch backlighting), telecommunications equipment (indicator and backlighting in phones/fax machines), and general consumer electronics requiring reliable indicator lights or backlighting solutions.

2. Technical Parameter Deep Dive

The electrical and optical performance of the LED is defined under specific test conditions, typically at a forward current (I_F) of 20mA and an ambient temperature (T_a) of 25°C. Understanding these parameters is essential for proper circuit design and ensuring long-term reliability.

2.1 Absolute Maximum Ratings

These ratings define the stress limits beyond which permanent damage to the device may occur. They are not for continuous operation. Key limits include a maximum reverse voltage (V_R) of 5V, a continuous forward current (I_F) of 30mA, and a peak forward current (I_FP) of 100mA under pulsed conditions (1/10 duty cycle at 1kHz). The maximum power dissipation (P_d) is 110mW. The device can operate within a temperature range of -40°C to +85°C and can be stored between -40°C and +90°C. Soldering temperature profiles are also specified to prevent package damage during assembly.

2.2 Electro-Optical Characteristics

The typical performance parameters provide the expected values under normal operating conditions. For the specific variant implied in the document (likely a green LED based on wavelength data), the luminous intensity (I_v) ranges from a minimum of 900 mcd to a maximum of 1800 mcd. The viewing angle (2θ_1/2), defined as the angle where intensity drops to half its peak value, is typically 120 degrees, confirming the wide-angle claim. The dominant wavelength (λ_d) for this example falls between 520nm and 535nm, placing it in the green spectrum. The forward voltage (V_F) ranges from 2.7V to 3.5V at 20mA. A current-limiting resistor is mandatory in the application circuit to prevent exceeding the maximum forward current, as LEDs exhibit a non-linear IV relationship where a small voltage increase can cause a large, potentially destructive, current surge.

3. Binning System Explanation

To ensure consistency in mass production, LEDs are sorted into performance bins based on key parameters. This allows designers to select parts that meet the specific needs of their application.

3.1 Luminous Intensity Binning

The luminous output is categorized into three bin codes: V2 (900-1120 mcd), W1 (1120-1420 mcd), and W2 (1420-1800 mcd). The tolerance for luminous intensity is ±11%. Designers must account for this variation when designing for minimum brightness requirements.

3.2 Dominant Wavelength Binning

The color (dominant wavelength) is binned into three codes: X (520-525 nm), Y (525-530 nm), and Z (530-535 nm), with a tight tolerance of ±1nm. This ensures color consistency within a batch, which is critical for applications where multiple LEDs are used adjacent to each other.

3.3 Forward Voltage Binning

The forward voltage is sorted into four bins: 10 (2.70-2.90V), 11 (2.90-3.10V), 12 (3.10-3.30V), and 13 (3.30-3.50V), with a tolerance of ±0.1V. Knowledge of the V_F bin is important for calculating the precise value of the current-limiting resistor to achieve the desired drive current, especially when operating from a low-voltage or tightly regulated power supply.

4. Mechanical and Package Information

The device uses a P-LCC-2 (Plastic Leaded Chip Carrier) package. Detailed package dimension drawings are provided in the datasheet, specifying the length, width, height, lead spacing, and pad geometry. These dimensions are critical for PCB footprint design. The package features a white body which aids in light reflection and a colorless clear epoxy lens. Polarity is indicated by the physical structure of the package, typically with a notch or a marked cathode. The recommended PCB pad pattern ensures proper soldering and mechanical stability.

5. Soldering and Assembly Guidelines

Proper handling and soldering are vital to maintain device integrity and performance.

5.1 Reflow Soldering Profile

For lead-free soldering, a specific temperature profile must be followed. The pre-heating stage should ramp from 150°C to 200°C over 60-120 seconds. The time above the liquidus temperature (217°C) should be maintained for 60-150 seconds, with a peak temperature not exceeding 260°C for more than 10 seconds. The maximum heating rate should be 3°C/sec, and the cooling rate should not exceed 6°C/sec. Reflow soldering should not be performed more than two times on the same device.

5.2 Hand Soldering

If hand soldering is necessary, extreme care must be taken. The soldering iron tip temperature should be below 350°C, and contact time with each terminal should not exceed 3 seconds. A low-power iron (≤25W) is recommended. A minimum interval of 2 seconds should be allowed between soldering each terminal to prevent thermal shock.

5.3 Storage and Moisture Sensitivity

The components are packaged in moisture-resistant bags with a desiccant and humidity indicator card. The bag should only be opened immediately before use in an environment controlled to less than 30°C and 60% relative humidity. Once opened, the components must be used within the specified floor life (not explicitly stated in the excerpt but typically defined by the Moisture Sensitivity Level, MSL). If the indicator card shows excessive moisture, the components must be baked at 60°C ±5°C for 24 hours before use.

6. Packaging and Ordering Information

The LEDs are supplied on 8mm wide embossed carrier tape, loaded into standard reels. A typical reel contains 2000 pieces, although minimum order quantities of 250, 500, or 1000 pieces may be available. The reel and tape dimensions are precisely specified to ensure compatibility with automated assembly equipment. The packaging label includes critical information such as the product number, quantity, and the specific bin codes for luminous intensity (CAT), dominant wavelength (HUE), and forward voltage (REF), along with the lot number for traceability.

7. Application Suggestions and Design Considerations

7.1 Typical Application Scenarios

• Automotive Interiors: Backlighting for dashboard instruments, control buttons, and switches. The wide viewing angle ensures visibility from different driver positions.
• Telecom/Consumer Electronics: Status indicators and keypad backlighting in phones, fax machines, and remote controls. The low current draw is beneficial for battery life.
• General Indicator Lights: Power status, mode selection, and alert indicators in various electronic devices.
• Light Pipe Applications: The optimized light output and wide angle make this series ideal for coupling into acrylic or polycarbonate light pipes, which then guide light to a desired location on a panel, allowing for flexible mechanical design.

7.2 Design Considerations

• Current Limiting: Always use a series resistor to set the forward current. Calculate the resistor value using R = (V_supply - V_F) / I_F. Use the maximum V_F from the datasheet (or the specific bin) to ensure the current never exceeds the maximum rating under worst-case conditions.
• Thermal Management: While power dissipation is low, ensure adequate PCB copper area or thermal vias if operating at high ambient temperatures or near the maximum current to maintain junction temperature within limits.
• ESD Protection: The device has an ESD withstand rating of 1000V (HBM). Implement standard ESD precautions during handling and assembly. For sensitive applications, consider adding transient voltage suppression on the lines connected to the LED.
• Optical Design: For light pipe applications, the distance and alignment between the LED and the pipe entrance are critical. The wide viewing angle helps but may require a reflector cup or tailored pipe design to maximize coupling efficiency.

8. Technical Comparison and Differentiation

The key differentiator of the 67-21 series is the integrated reflector within the P-LCC-2 package. Compared to standard SMD LEDs without this feature, it offers superior light output efficiency and a more controlled, wider beam pattern. This eliminates the need for an external reflector in many designs, saving space and cost. The combination of a wide 120-degree viewing angle and availability in multiple colors within the same package footprint provides design flexibility. Its compatibility with all major soldering processes also makes it a versatile drop-in component for various production lines.

9. Frequently Asked Questions (Based on Technical Parameters)

9.1 Why is a current-limiting resistor absolutely necessary?

LEDs are diodes with an exponential current-voltage (I-V) relationship. A small increase in voltage beyond the nominal forward voltage causes a very large increase in current. Without a resistor to limit this current, the LED will quickly draw excessive current, leading to overheating and catastrophic failure, even if the power supply voltage seems only slightly high. The resistor provides a linear, predictable voltage drop to stabilize the current.

9.2 Can I drive this LED with a voltage source directly?

No. Driving an LED directly with a voltage source is strongly discouraged and will likely destroy the device. It must be driven with a current source or, more commonly, a voltage source in series with a current-limiting resistor as described above.

9.3 What does the "binning" of parameters mean for my design?

Binning means the LEDs are tested and sorted into groups based on performance. If your design requires very consistent brightness or color across multiple units, you should specify the required bin codes (e.g., W2 for highest brightness, Y for a specific green hue) when ordering. If your design can tolerate more variation, you may accept a wider mix of bins, which could be more cost-effective.

9.4 How many times can I reflow solder this component?

The datasheet specifies that reflow soldering should not be performed more than two times. Each reflow cycle subjects the component to thermal stress, which can potentially degrade the internal wire bonds or the epoxy encapsulant. For rework, specific guidelines using a dual-head soldering iron are provided to minimize localized heating.

10. Practical Design and Usage Case

Scenario: Designing a backlit membrane switch panel. A designer is creating a control panel with 12 illuminated buttons. Each button uses a light pipe to channel light from an SMD LED mounted on the main PCB to the button cap. The 67-21 series is selected for its wide viewing angle, which ensures efficient coupling into the light pipe's entrance, and its low current draw, as the panel is powered by a 5V rail with limited current budget. The designer calculates the current-limiting resistor value using the maximum V_F of 3.5V to guarantee safe operation across all units: R = (5V - 3.5V) / 0.02A = 75 Ohms. A standard 75Ω or 82Ω resistor is chosen. The PCB layout places the LEDs precisely under the light pipe openings, and the assembly follows the specified reflow profile. By specifying a tight wavelength bin (e.g., Y: 525-530nm), the designer ensures all buttons have a consistent green color.

11. Operating Principle Introduction

Light-emitting diodes are semiconductor devices that emit light through electroluminescence. When a forward voltage is applied across the p-n junction, electrons from the n-type material recombine with holes from the p-type material in the active region. This recombination process releases energy in the form of photons (light). The specific wavelength (color) of the emitted light is determined by the bandgap energy of the semiconductor materials used (e.g., InGaN for green/blue). The integrated reflector in the 67-21 series is a shaped cavity around the semiconductor chip. It reflects light that would otherwise be emitted sideways or absorbed by the package back towards the top viewing direction, thereby increasing the useful light output and shaping the radiation pattern into a wider, more uniform beam.

12. Technology Trends

The general trend in SMD indicator LEDs continues towards higher efficiency (more light output per unit of electrical power), improved color consistency through advanced binning and manufacturing control, and enhanced reliability. Packaging technologies are evolving to allow for even wider viewing angles and better thermal management in smaller footprints. There is also a growing emphasis on compatibility with lead-free and high-temperature soldering processes to meet global environmental regulations and the demands of automotive-grade applications. The integration of optical features, like the reflector in this series, directly into the LED package is a key trend that simplifies end-product design and improves optical performance.