SMD Top View LED 67-21 Series Datasheet - P-LCC-2 Package - 2.5-3.5V - 90mW - Brilliant Green - English Technical Document

1. Product Overview

The 67-21 series represents a family of high-performance, surface-mount Top View LEDs designed for modern electronic applications requiring reliable, low-power indicator solutions. These LEDs are housed in a compact P-LCC-2 (Plastic Leaded Chip Carrier) package with a colorless clear window, offering a brilliant green emitted color achieved through AlGaInP chip technology. The core design philosophy centers on providing a wide viewing angle and optimized light output, making them particularly suitable for applications where visibility from various angles is critical.

The primary advantage of this series lies in its combination of optical performance and manufacturing compatibility. The package design incorporates an inter-reflector that enhances light coupling efficiency, directing more light through the top of the component. This feature, coupled with a low forward current requirement, makes these LEDs ideal for power-sensitive applications such as portable consumer electronics, automotive interiors, and telecommunications equipment. The device is fully compatible with standard automated pick-and-place equipment and common soldering processes, including vapor-phase reflow, infrared reflow, and wave soldering, facilitating high-volume production.

The target market is broad, encompassing automotive electronics for dashboard and switch backlighting, telecommunication devices for status indicators, general industrial control panels, and consumer electronics. Its suitability for light pipe applications is a key differentiator, allowing designers to guide light from the LED to a desired location on a front panel or display.

2. In-Depth Technical Parameter Analysis

This section provides a detailed, objective interpretation of the key electrical, optical, and thermal parameters specified in the datasheet, essential for proper circuit design and reliability assurance.

2.1 Absolute Maximum Ratings

The Absolute Maximum Ratings define the stress limits beyond which permanent damage to the LED may occur. These are not operating conditions.

• Reverse Voltage (VR): 5V - Applying a reverse bias exceeding 5V can damage the LED's semiconductor junction. The datasheet explicitly notes that LED components are not supposed to be reverse operated, emphasizing the importance of correct polarity in circuit design.
• Forward Current (IF): 25mA - This is the maximum continuous DC current that can be applied to the LED. Exceeding this value will generate excessive heat, leading to accelerated lumen depreciation and potential catastrophic failure.
• Peak Forward Current (IFP): 50mA - A pulsed current rating (at a duty cycle of 1/10 and 1kHz frequency). This allows for brief periods of higher brightness but must be managed with careful thermal consideration.
• Power Dissipation (Pd): 90mW - The maximum amount of power the package can dissipate as heat at an ambient temperature (Ta) of 25°C. This value derates with increasing ambient temperature.
• Operating & Storage Temperature: The device is rated for operation from -40°C to +85°C and can be stored from -40°C to +90°C, indicating robustness for harsh environments.
• ESD (HBM): 2000V - The Human Body Model electrostatic discharge rating. While 2000V is a standard level, proper ESD handling procedures during assembly are still mandatory to prevent latent defects.
• Soldering Temperature: Specifies profiles for reflow (260°C for 10 sec) and hand soldering (350°C for 3 sec). Adherence to these limits is crucial to prevent package cracking or internal bond wire damage.

2.2 Electro-Optical Characteristics

These parameters are measured under standard test conditions (Ta=25°C, IF=10mA) and define the device's performance.

• Luminous Intensity (Iv): 225 to 565 mcd (min to max) - This is the measured light output in a specific direction. The wide range indicates a binning system is used (detailed later). At a typical 10mA drive, the output is substantial for indicator purposes.
• Viewing Angle (2θ1/2): 120° (typical) - This is the full angle at which the luminous intensity drops to half of its peak value. A 120° angle is exceptionally wide, ensuring good visibility off-axis, which is the defining feature of "Top View" LEDs.
• Peak Wavelength (λp): 518 nm (typical) - The wavelength at which the spectral power distribution is maximum. This corresponds to a brilliant green color.
• Dominant Wavelength (λd): 517.5 to 535.5 nm - The single wavelength perceived by the human eye that matches the LED's color. This range is subdivided into bins.
• Spectral Bandwidth (Δλ): 35 nm (typical) - The width of the emitted spectrum. A narrower bandwidth indicates a more saturated, pure color.
• Forward Voltage (VF): 2.5 to 3.5 V - The voltage drop across the LED when driven at 10mA. This range is critical for designing the current-limiting resistor. The value has a tolerance of ±0.1V and is also binned.
• Reverse Current (IR): 10 μA max at VR=5V - A very low leakage current when the device is reverse-biased at its maximum rating.

3. Binning System Explanation

To ensure color and brightness consistency in production, the LEDs are sorted into bins based on key parameters. Understanding this system is vital for applications requiring uniform appearance.

3.1 Dominant Wavelength Binning (HUE)

The dominant wavelength is grouped into bins labeled B10 through B18, each covering a 2nm range from 517.5nm to 535.5nm. For example, bin B17 covers 531.5nm to 533.5nm. The tolerance for any given unit within a bin is ±1nm. Designers must specify the required bin(s) if color consistency across multiple LEDs is critical.

3.2 Luminous Intensity Binning (CAT)

The light output is binned into four groups: S2 (225-285 mcd), T1 (285-360 mcd), T2 (360-450 mcd), and U1 (450-565 mcd). The tolerance is ±11%. Selecting a higher bin (e.g., U1) guarantees a minimum higher brightness but may come at a premium cost.

3.3 Forward Voltage Binning (REF)

Forward voltage is binned for groups related to other parameters (e.g., Group B17 has voltage bins 9-13). These bins range from 2.50-2.70V (Bin 9) to 3.30-3.50V (Bin 13) with a ±0.1V tolerance. Knowing the VF bin can help optimize the current-limiting resistor value for more consistent current drive across units, especially in parallel arrays.

4. Performance Curve Analysis

The typical characteristic curves provide insight into how the LED behaves under non-standard conditions. These are representative graphs, not guaranteed minima/maxima.

4.1 Relative Luminous Intensity vs. Forward Current

This curve shows that light output increases with forward current but in a non-linear fashion. Driving the LED above the recommended 10-20mA range yields diminishing returns in brightness while significantly increasing power dissipation and junction temperature, which in turn reduces lifespan.

4.2 Relative Luminous Intensity vs. Ambient Temperature

This graph demonstrates the negative impact of temperature on light output. As the ambient temperature rises, the luminous intensity decreases. For example, at +85°C, the output may be only 70-80% of its value at 25°C. This must be factored into designs for high-temperature environments to ensure sufficient brightness.

4.3 Forward Current Derating Curve

Perhaps the most critical graph for reliability, this curve dictates the maximum allowable continuous forward current as a function of ambient temperature. As Ta increases, the maximum permissible IF must be reduced to keep the junction temperature within safe limits and prevent thermal runaway. At 85°C, the maximum continuous current is significantly lower than the 25mA absolute maximum rating at 25°C.

4.4 Forward Voltage vs. Forward Current & Spectrum Distribution

The VF vs. IF curve shows the diode's exponential characteristic. The spectrum distribution plot confirms the peak wavelength around 518nm (green) with the stated ~35nm bandwidth. The radiation diagram (polar plot) visually confirms the wide 120° viewing angle.

5. Mechanical and Package Information

5.1 Package Dimensions

The P-LCC-2 package has a standard footprint. Key dimensions include the overall body size, the lead spacing, and the placement of the cathode identifier (typically a notch or a green dot on the package). The exact dimensions are provided in the datasheet drawing with a standard tolerance of ±0.1mm unless otherwise noted. This information is essential for PCB pad layout design in CAD software.

5.2 Polarity Identification

Correct polarity is mandatory. The package includes a visual marker to identify the cathode. Misapplication of reverse voltage, even below the 5V rating, is discouraged as it can stress the device. The PCB silkscreen should clearly indicate polarity.

6. Soldering and Assembly Guidelines

6.1 Reflow Soldering Parameters

The component is rated for a peak reflow temperature of 260°C for up to 10 seconds. This aligns with standard lead-free (Pb-free) reflow profiles (e.g., IPC/JEDEC J-STD-020). The profile should be verified to ensure the LED's body temperature does not exceed this limit. Hand soldering, if necessary, should be performed quickly at 350°C for a maximum of 3 seconds per lead, using a grounded iron tip.

6.2 Moisture Sensitivity and Storage

The LEDs are packaged in moisture-resistant barrier bags with desiccant. The bag should only be opened immediately before use in a controlled environment (<30°C / 60% RH). Once opened, the components must be subjected to soldering within the timeframe specified by the Moisture Sensitivity Level (MSL) – which, based on the preconditioning note (JEDEC J-STD-020D Level 3), is likely 168 hours at <30°C/60% RH. Exceeding this floor life requires baking the components before use to remove absorbed moisture and prevent "popcorning" during reflow.

7. Packaging and Ordering Information

7.1 Tape and Reel Specifications

The product is available on 8mm carrier tape wound on standard reels. Common loaded quantities are 1000, 1500, or 2000 pieces per reel. The datasheet provides detailed dimensions for the carrier tape pockets, reel hub, and overall reel to ensure compatibility with automated feeders.

7.2 Label Explanation

The reel label contains critical information for traceability and verification: Product Number (P/N), quantity (QTY), and the specific bin codes for Luminous Intensity (CAT), Dominant Wavelength (HUE), and Forward Voltage (REF). The Lot Number (LOT No) provides full manufacturing traceability.

8. Application Recommendations

8.1 Typical Application Circuits

The fundamental drive circuit is a voltage source (Vcc), a current-limiting resistor (Rseries), and the LED in series. Rseries = (Vcc - VF) / IF. Using a current-limiting resistor is mandatory. As noted in the "Precautions for Use," even a slight voltage shift without a resistor can cause a large current change, leading to immediate burnout due to the diode's exponential I-V characteristic. For constant brightness across varying Vcc or temperature, consider using a dedicated LED driver IC or a simple constant-current circuit.

8.2 Thermal Management Considerations

While the package is small, thermal management is still important for longevity. The power dissipated is Pd = VF * IF. At 20mA and a typical VF of 3.0V, this is 60mW. Ensure the PCB provides adequate copper area (thermal relief pads) to conduct heat away from the LED's solder joints, especially when operating near maximum ratings or in high ambient temperatures. Avoid placing the LED near other heat-generating components.

8.3 Design for Light Pipe Applications

For light pipe use, align the LED centrally under the pipe's input surface. The wide viewing angle helps couple more light into the pipe. Consider the gap between the LED and the pipe; a small, controlled air gap or the use of optical silicone gel can improve coupling efficiency and reduce light loss. The colorless clear window of the LED is beneficial here as it does not introduce unwanted tint.

9. Technical Comparison and Differentiation

The 67-21 series differentiates itself primarily through its 120° wide viewing angle and optimized inter-reflector design for top emission. Compared to standard side-view or narrow-angle top-view LEDs, this makes it superior for applications where the viewer is not directly perpendicular to the LED, such as in automotive dashboards or front-panel indicators mounted at an angle. Its low current requirement (effective brightness at 10mA) also makes it more energy-efficient than LEDs requiring 20mA for similar output. The comprehensive binning system offers designers the ability to select for color and brightness consistency, a feature not always available in lower-cost generic LEDs.

10. Frequently Asked Questions (Based on Technical Parameters)

10.1 Can I drive this LED at 20mA continuously?

Yes, 20mA is below the Absolute Maximum Rating of 25mA. However, you must consult the Forward Current Derating Curve. At an ambient temperature of 25°C, 20mA is acceptable. If the ambient temperature is expected to reach 85°C, the derating curve will indicate a lower maximum allowable continuous current to ensure reliable operation. Always design with the worst-case ambient temperature in mind.

10.2 Why is a current-limiting resistor mandatory?

An LED is a diode with a non-linear, exponential current-voltage relationship. A small increase in voltage (e.g., from a power supply ripple or tolerance) can cause a very large, potentially destructive increase in current. The resistor provides a linear relationship (Ohm's Law) that dominates the circuit, making the current predictable and stable despite small voltage variations.

10.3 How do I interpret the bin codes when ordering?

To ensure a uniform appearance in your product, you should specify the allowable bins for your order. For example, you might specify "CAT: U1 or T2" for high brightness and "HUE: B16-B18" for a specific shade of green. Your distributor or manufacturer can provide parts matching these bin criteria. Ordering without specifying bins may result in a mix of colors and brightness levels.

11. Practical Design and Usage Case Studies

11.1 Case Study: Automotive Dashboard Switch Backlighting

In this application, multiple switches on a curved dashboard need to be evenly backlit. The wide 120° viewing angle of the 67-21 LED ensures that light is emitted towards the driver even when the LED is mounted flat on the PCB behind a angled switch cap. A light pipe may not even be necessary, simplifying assembly. The LED is driven at 10-15mA via the vehicle's 12V system using an appropriate dropping resistor or a regulated 3.3V/5V rail. The operating temperature range (-40°C to +85°C) comfortably covers the automotive interior environment.

11.2 Case Study: Industrial Panel Status Indicator with Light Pipe

A control panel has status indicators (Power, Fault, Ready) that need to be visible from several feet away and from various operator positions. The LEDs are mounted on a main PCB deep inside the enclosure. Clear acrylic light pipes channel the light to labeled icons on the front panel. The brilliant green color (518nm) of the 67-21 LED provides high visual contrast. The inter-reflector design maximizes the amount of light coupled into the base of the light pipe, ensuring a bright, clear indicator even in well-lit rooms.

12. Operational Principle Introduction

Light Emitting Diodes (LEDs) 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. The 67-21 series utilizes an AlGaInP (Aluminum Gallium Indium Phosphide) chip, which is a common material system for producing high-efficiency red, orange, yellow, and green LEDs. The "water clear" resin encapsulant does not contain a phosphor and allows the native color from the chip to be emitted, resulting in a saturated brilliant green.

13. Technology Trends and Context

The 67-21 series sits within broader industry trends. The move towards P-LCC-2 and similar compact surface-mount packages reflects the demand for miniaturization and automated assembly. The emphasis on wide viewing angles addresses the need for better user experience in consumer and automotive electronics. Compliance with RoHS (Restriction of Hazardous Substances), REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals), and Halogen-Free standards is now a baseline requirement for global market access, driven by environmental regulations and consumer preference. The detailed binning system highlights the industry's focus on color consistency and performance predictability, which are critical for brand image in final products. Future trends may push for even higher efficiency (more mcd/mA), narrower color tolerances, and packages that enable even better thermal management for higher drive currents.