Top View LED 67-21 Series Technical Data Sheet - Package 3.2x2.8x1.9mm - Forward Voltage 1.75-2.35V - Brilliant Red Color - English Documentation

1. Product Overview

The 67-21 series represents a family of surface-mount Top View LEDs designed for indicator and backlighting applications. This specific model features a brilliant red emission color achieved through AlGaInP chip technology. The device is housed in a compact P-LCC-2 package with a white body and a colorless clear window, which contributes to its wide viewing angle characteristics. A key design feature is the integrated inter-reflector within the package, which optimizes light coupling efficiency. This makes the LED particularly suitable for use with light pipes, where efficient light transmission from the source to the display point is critical. The low current requirement further enhances its suitability for power-sensitive applications such as portable electronic devices and automotive dashboards.

1.1 Core Advantages and Target Market

The primary advantages of this LED series include its wide viewing angle of 120 degrees, compatibility with standard automated placement and soldering processes (including vapor-phase, infrared reflow, and wave soldering), and its Pb-free, RoHS-compliant construction. The device is supplied on 8mm tape and reel for high-volume assembly. Its primary target markets are automotive electronics (for dashboard and switch backlighting), telecommunications equipment (for indicators in phones and fax machines), general switch and symbol illumination, and as a flat backlight source for LCDs. The combination of reliability, ease of assembly, and optical performance positions it as a versatile component for general-purpose indicator use.

2. In-Depth Technical Parameter Analysis

The performance of the LED is defined under standard test conditions of an ambient temperature (Ta) of 25°C. A comprehensive understanding of these parameters is essential for proper circuit design and performance prediction.

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. The key absolute maximum ratings are: a reverse voltage (V_R) of 5V, a continuous forward current (I_F) of 25mA, and a peak forward current (I_FP) of 100mA for pulsed operation at a 1/10 duty cycle and 1kHz frequency. The maximum power dissipation (P_d) is 100mW. The device can operate within a temperature range of -40°C to +85°C and can be stored between -40°C and +90°C. The soldering temperature profile is critical: for reflow soldering, a peak temperature of 260°C for a maximum of 10 seconds is specified, while for hand soldering, the iron tip temperature should not exceed 350°C for 3 seconds.

2.2 Electro-Optical Characteristics

The typical operating point for photometric and electrical specifications is at a forward current of 20mA. The luminous intensity (I_v) has a typical range from 140mcd to 360mcd, which is further divided into specific bins (R2, S1, S2, T1). The dominant wavelength (λ_d) for the brilliant red variant is between 621nm and 631nm, with a typical peak wavelength (λ_p) around 632nm. The spectral bandwidth (Δλ) is approximately 20nm. Electrically, the forward voltage (V_F) at 20mA ranges from 1.75V to 2.35V, and the reverse current (I_R) is guaranteed to be less than 10μA at the maximum reverse voltage of 5V. Tolerances are specified as ±11% for luminous intensity, ±1nm for dominant wavelength, and ±0.1V for forward voltage.

3. Binning System Explanation

To ensure consistency in brightness and color in production applications, the LEDs are sorted into bins based on key parameters. This allows designers to select the appropriate grade for their application needs.

3.1 Luminous Intensity Binning

The luminous output is categorized into four bins: R2 (140-180 mcd), S1 (180-225 mcd), S2 (225-285 mcd), and T1 (285-360 mcd). All measurements are taken at I_F=20mA. Selecting a higher bin (e.g., T1) guarantees a brighter LED, which may be necessary for applications requiring high visibility or when used behind light pipes with high attenuation.

3.2 Dominant Wavelength Binning

The color (hue) is controlled by binning the dominant wavelength. For this brilliant red series, the bins are grouped under code 'F', with sub-bins FF1 (621-626 nm) and FF2 (626-631 nm). A tighter wavelength distribution within an application ensures a uniform color appearance across multiple indicators.

3.3 Forward Voltage Binning

The forward voltage is binned into three groups under code 'B': B0 (1.75-1.95V), B1 (1.95-2.15V), and B2 (2.15-2.35V). Knowledge of the V_F bin is crucial for designing current-limiting circuitry, especially when driving multiple LEDs in series, to ensure uniform current distribution and brightness.

4. Performance Curve Analysis

The provided characteristic curves offer valuable insights into the LED's behavior under non-standard conditions.

4.1 Relative Luminous Intensity vs. Ambient Temperature

The curve shows that luminous intensity is inversely related to junction temperature. As the ambient temperature rises from -40°C to +110°C, the relative output decreases. At the maximum operating temperature of +85°C, the output is significantly lower than at 25°C. This thermal derating must be accounted for in designs where high ambient temperatures are expected, potentially requiring the selection of a higher intensity bin or active cooling.

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

The I-V curve is non-linear, typical of a diode. At the recommended 20mA operating point, the voltage falls within the binned range. The curve allows designers to estimate the voltage drop at different drive currents, which is essential for power supply design.

4.3 Relative Luminous Intensity vs. Forward Current

This curve demonstrates that light output is approximately proportional to forward current in the typical operating range. However, driving the LED above the absolute maximum rating of 25mA is prohibited, as it will reduce lifetime and reliability due to excessive heat generation.

4.4 Radiation Pattern and Spectrum Distribution

The radiation diagram confirms the wide 120-degree viewing angle, showing a Lambertian-like emission pattern. The spectral distribution plot shows a single peak centered around 632nm, which is characteristic of AlGaInP red LEDs, with a defined bandwidth ensuring color purity.

5. Mechanical and Package Information

The P-LCC-2 package has dimensions of approximately 3.2mm in length, 2.8mm in width, and 1.9mm in height (tolerance ±0.1mm unless otherwise noted). The technical drawing provides detailed measurements for the LED body, lens, and the critical solder pad footprint. Correct pad design is essential for reliable soldering and proper alignment during reflow. The polarity is indicated by the cathode mark on the package. The recommended PCB land pattern ensures sufficient solder fillet formation and mechanical stability.

6. Soldering and Assembly Guidelines

The device is fully compatible with standard SMT assembly processes. For reflow soldering, a profile with a peak temperature not exceeding 260°C for 10 seconds is mandatory to prevent damage to the plastic package and the internal die bond. A standard ramp-up and cooling rate should be followed. For hand soldering, extreme care must be taken: use a grounded iron with a tip temperature below 350°C, and limit the contact time to 3 seconds per pad. Avoid mechanical stress on the lens during and after assembly. Moisture sensitivity is addressed by shipping the components in sealed aluminum moisture-proof bags with desiccant.

7. Packaging and Ordering Information

The LEDs are supplied on 8mm carrier tape, with a standard loaded quantity of 2000 pieces per reel. The reel dimensions are specified for compatibility with automated feeders. The labeling on the reel includes critical information: Part Number (PN), Customer Part Number (CPN), quantity (QTY), lot number (LOT NO), and the specific bin codes for luminous intensity (CAT), dominant wavelength (HUE), and forward voltage (REF). This traceability is vital for quality control and consistent manufacturing.

8. Application Recommendations

8.1 Typical Application Scenarios

This LED is ideal for status indicators in consumer electronics, backlighting for membrane switches and panel legends, and illumination for light pipes in automotive dashboards or industrial control panels. Its wide viewing angle makes it suitable for applications where the indicator needs to be visible from various angles.

8.2 Design Considerations

Always use a current-limiting resistor in series with the LED. The resistor value (R) can be calculated using R = (V_supply - V_F) / I_F. Use the maximum V_F from the bin or datasheet to ensure the current does not exceed 20mA under worst-case conditions. For uniform brightness in multi-LED arrays, consider using constant current drivers or binning LEDs for consistent V_F. When using with light pipes, ensure the pipe material has high transmittance for red light and design the interface to minimize optical losses.

9. Reliability and Quality Assurance

The product undergoes a comprehensive suite of reliability tests with a 90% confidence level and 10% Lot Tolerance Percent Defective (LTPD). The test portfolio includes reflow soldering resistance, temperature cycling (-40°C to +100°C), thermal shock, high and low temperature storage, DC operating life at 20mA for 1000 hours, and high temperature/high humidity (85°C/85% RH) testing. These tests validate the LED's robustness for demanding automotive and industrial environments, ensuring long-term performance stability.

10. Technical Comparison and Differentiation

Compared to older through-hole LEDs, this SMD package offers significant space savings, better suitability for automated production, and improved reliability by eliminating manual soldering. Within the SMD LED landscape, the 67-21 series differentiates itself with its specific package geometry optimized for light pipe coupling and its wide 120-degree viewing angle, which is broader than many standard SMD LEDs. The availability of precise binning for intensity, color, and voltage provides an advantage for applications requiring high consistency.

11. Frequently Asked Questions (FAQs)

Q: Can I drive this LED without a current-limiting resistor?
A: No. An LED is a current-driven device. Connecting it directly to a voltage source will cause excessive current to flow, instantly destroying it. Always use a series resistor or a constant-current driver.

Q: What is the difference between peak wavelength and dominant wavelength?
A: Peak wavelength (λ_p) is the wavelength at which the spectral power distribution is maximum. Dominant wavelength (λ_d) is the single wavelength of monochromatic light that matches the perceived color of the LED. For color specification, dominant wavelength is more relevant.

Q: How do I interpret the bin codes on the label?
A: The CAT code corresponds to the luminous intensity bin (e.g., S1), the HUE code to the dominant wavelength bin (e.g., FF1), and the REF code to the forward voltage bin (e.g., B1). These ensure you receive LEDs with the specific performance characteristics you ordered.

Q: Is a heat sink required?
A: For normal operation at 20mA or below, a dedicated heat sink is not typically required for a single LED. However, thermal management through proper PCB layout (thermal relief pads, copper pours) is good practice, especially for high-density arrays or high ambient temperature applications.

12. Practical Design and Usage Examples

Example 1: Dashboard Indicator Cluster: In an automotive dashboard, multiple 67-21 LEDs (in red and other colors from the series) can be mounted on a single PCB. Each LED is paired with a dedicated light pipe to guide its light to a specific icon (e.g., check engine, oil pressure). The wide viewing angle ensures the icon is illuminated evenly for both the driver and passenger. The LEDs are driven via the vehicle's 12V system using appropriate series resistors, calculated using the maximum V_F to ensure brightness consistency across the temperature range inside the car.

Example 2: Industrial Control Panel: A machine operator panel uses these LEDs behind engraved acrylic panels to indicate machine states (Running - Green, Fault - Red, Standby - Yellow). The white package of the LED minimizes color contamination from the PCB. The designer selects LEDs from the same intensity and voltage bin to guarantee uniform brightness across all indicators. The SMD package allows for a very flat and compact panel design.

13. Operational Principle

This LED operates on the principle of electroluminescence in a semiconductor p-n junction. The chip material is Aluminum Gallium Indium Phosphide (AlGaInP). When a forward voltage exceeding the diode's threshold is applied, electrons from the n-region and holes from the p-region are injected into the active region where they recombine. In AlGaInP, this recombination releases energy in the form of photons (light) in the red portion of the visible spectrum (approximately 630nm). The specific composition of the AlGaInP layers determines the precise wavelength of the emitted light. The colorless clear epoxy lens encapsulates the chip, protects it from the environment, and shapes the emitted light into the desired radiation pattern.

14. Industry Trends and Context

The trend in indicator LEDs continues towards higher efficiency (more light output per unit of electrical input), smaller package sizes, and improved reliability. There is also a growing demand for tighter color and brightness consistency (binning) for aesthetic and functional reasons in consumer and automotive electronics. While this 67-21 series is a well-established product, newer LED technologies may offer higher efficacy. However, its combination of a proven package, wide availability, specific optical characteristics for light piping, and comprehensive reliability data ensures its continued relevance in many design applications where a balance of performance, cost, and proven reliability is required. The drive for miniaturization and higher integration in electronics also supports the use of such standardized, automatable SMD components.