SMD LED 91-21SURC/S530-A6/TR7 Datasheet - 2.0x1.25x1.1mm - 2.0V - 60mW - Brilliant Red - English Technical Document

1. Product Overview

This document provides the complete technical specifications for a surface-mount device (SMD) LED identified by the part number 91-21SURC/S530-A6/TR7. This component is a mono-color, brilliant red LED designed for modern electronic applications requiring miniaturization, reliability, and efficient assembly.

The core advantage of this LED lies in its compact EIA-standard package, which measures approximately 2.0mm x 1.25mm x 1.1mm. This small footprint enables significant reductions in printed circuit board (PCB) size, allows for higher component packing density, reduces required storage space, and ultimately contributes to the development of smaller end-user equipment. Its light weight further makes it an ideal choice for miniature and portable applications. Furthermore, the package is fully compatible with automated pick-and-place equipment, ensuring high placement accuracy and consistency in high-volume manufacturing environments.

The product is compliant with major environmental and safety directives. It is manufactured as a Pb-free (lead-free) component. The product itself remains within the specifications of the RoHS (Restriction of Hazardous Substances) compliant version. It also complies with EU REACH regulations and meets halogen-free requirements, with Bromine (Br) and Chlorine (Cl) content each below 900 ppm and their sum below 1500 ppm.

2. In-Depth Technical Parameter Analysis

2.1 Absolute Maximum Ratings

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

• Reverse Voltage (V_R): 5V. Exceeding this voltage in reverse bias can cause junction breakdown.
• Continuous Forward Current (I_F): 25 mA. This is the maximum DC current recommended for reliable long-term operation.
• Peak Forward Current (I_FP): 60 mA. This current can be applied under pulsed conditions with a duty cycle of 1/10 at 1 kHz.
• Power Dissipation (P_d): 60 mW. This is the maximum power the package can dissipate at an ambient temperature (T_a) of 25°C. Derating may be necessary at higher temperatures.
• Operating Temperature (T_opr): -40°C to +85°C. The device is designed to function within this ambient temperature range.
• Storage Temperature (T_stg): -40°C to +100°C.
• Electrostatic Discharge (ESD) Human Body Model (HBM): 2000V. Proper ESD handling procedures must be followed.
• Soldering Temperature: 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

The electro-optical characteristics are measured at a standard test condition of an ambient temperature of 25°C and a forward current of 20 mA, unless otherwise noted. These parameters define the light output and electrical performance.

• Luminous Intensity (I_v): The typical value is 1232 mcd (millicandela), with a minimum of 802 mcd. This indicates a very bright output for its size.
• Viewing Angle (2θ_1/2): 25 degrees (typical). This is a relatively narrow viewing angle, concentrating the light output in a forward-directed beam.
• Peak Wavelength (λ_p): 632 nm (typical). This is the wavelength at which the spectral power distribution is maximum.
• Dominant Wavelength (λ_d): 624 nm (typical). This is the single wavelength perceived by the human eye, defining the color as brilliant red.
• Spectral Bandwidth (Δλ): 20 nm (typical). This measures the width of the emitted spectrum at half the maximum intensity (FWHM).
• Forward Voltage (V_F): 2.0V (typical), with a range from 1.7V (min) to 2.4V (max) at 20 mA. An external current-limiting resistor is mandatory to prevent thermal runaway, as the LED's V_F has a negative temperature coefficient.
• Reverse Current (I_R): Maximum of 10 µA at a reverse voltage of 5V.

2.3 Device Selection and Binning

The LED uses an AlGaInP (Aluminum Gallium Indium Phosphide) chip material to produce its brilliant red color. The resin lens is water-clear, which maximizes light output and preserves color purity. The datasheet indicates the existence of a binning system for key parameters, though specific bin code details are not provided in the excerpt. Typically, such systems involve ranking for:

• Luminous Intensity (CAT): Groups LEDs based on their measured light output.
• Dominant Wavelength / Hue (HUE): Groups LEDs based on their precise color point.
• Forward Voltage (REF): Groups LEDs based on their V_F characteristics.

This binning allows designers to select LEDs with tightly matched performance for applications requiring consistency, such as backlighting arrays or status indicator clusters.

3. Performance Curve Analysis

While the specific graphs are not detailed in the text, typical electro-optical characteristic curves for such an LED would include:

• Relative Luminous Intensity vs. Forward Current (I_v vs. I_F): This curve shows how light output increases with current, typically in a sub-linear fashion at higher currents due to heating and efficiency droop.
• Forward Voltage vs. Forward Current (V_F vs. I_F): This is the diode's I-V curve, showing the exponential relationship. It is crucial for designing the driving circuit.
• Relative Luminous Intensity vs. Ambient Temperature (I_v vs. T_a): This curve demonstrates the thermal quenching effect, where light output decreases as the junction temperature rises. Understanding this is key for thermal management in high-power or high-ambient-temperature applications.
• Spectral Power Distribution: A graph showing the intensity of emitted light across different wavelengths, centered around 632 nm with a ~20 nm bandwidth.

4. Mechanical and Package Information

4.1 Package Outline Dimensions

The LED is housed in a standard SMD package. Key dimensions (typical, in mm, tolerance ±0.1 unless noted) include a body length of approximately 2.0 mm, a width of 1.25 mm, and a height of 1.1 mm. The package includes two anode/cathode terminals for soldering. A polarity indicator (likely a notch or a mark on the package) identifies the cathode. Detailed mechanical drawings should be consulted for precise pad layout design on the PCB to ensure proper soldering and alignment.

4.2 Packaging for Shipping and Handling

The components are supplied in a tape-and-reel format compatible with automated assembly. They are packaged on 12 mm wide tape mounted on a 7-inch diameter reel. Each reel contains 1000 pieces. For moisture sensitivity, the reels are sealed inside an aluminum moisture-proof bag along with a desiccant. A label on the bag provides critical information including the product number, lot number, quantity, and the aforementioned binning codes (CAT, HUE, REF).

5. Soldering, Assembly, and Handling Guidelines

5.1 Storage and Moisture Sensitivity

This LED is moisture-sensitive. Before opening the sealed bag, it should be stored at ≤ 30°C and ≤ 90% RH. After opening, the "floor life" (time components can be exposed to ambient factory conditions) is 72 hours at ≤ 30°C and ≤ 60% RH. Unused parts must be resealed in a moisture-proof bag with fresh desiccant. If the desiccant indicator has changed color or the exposure time is exceeded, a baking treatment at 60 ± 5°C for 24 hours is required before soldering.

5.2 Reflow Soldering Profile

A lead-free (Pb-free) reflow soldering profile is specified:

• Pre-heating: Ramp from ambient to 150-200°C in 60-120 seconds (max ramp rate 3°C/sec).
• Reflow: Time above liquidus (217°C) should be 60-150 seconds. The peak temperature must not exceed 260°C, and the time within 5°C of the peak should be a maximum of 10 seconds. The time above 255°C must not exceed 30 seconds.
• Cooling: Maximum cooling rate of 6°C/sec.

Reflow soldering should not be performed more than two times on the same component. No mechanical stress should be applied to the LED during heating or cooling.

5.3 Hand Soldering and Rework

If hand soldering is unavoidable, use a soldering iron with a tip temperature ≤ 350°C and apply heat to each terminal for ≤ 3 seconds. The iron power should be ≤ 25W. Allow a cooling interval of at least 2 seconds between soldering each terminal. Rework is strongly discouraged. If absolutely necessary, a specialized double-head soldering iron designed for SMD components should be used to simultaneously heat both terminals and lift the part without damaging the PCB pads or the component. The impact of rework on LED performance must be verified.

6. Application Suggestions and Design Considerations

6.1 Typical Applications

This high-brightness, compact SMD LED is suitable for a wide range of applications, including:

• Small status indicators in consumer and industrial indoor equipment.
• Flat backlighting for LCD panels, membrane switches, and symbols.
• Indicator and backlighting in office automation equipment (printers, scanners).
• Battery-powered device indicators (e.g., portable tools, medical devices).
• Indicator lights in audio/video equipment.
• Backlighting for automotive dashboards (secondary indicators) and control switches.
• Telecommunication equipment indicators (phones, fax machines).

6.2 Critical Design Considerations

• Current Limiting: An external series resistor is MANDATORY to set the forward current. The driver circuit must be designed to prevent current spikes or exceeding the absolute maximum ratings.
• Thermal Management: Although power dissipation is low, ensuring a good thermal path via the PCB pads is important for maintaining luminous intensity and long-term reliability, especially in high ambient temperatures or when driven near maximum current.
• ESD Protection: Implement appropriate ESD protection on input lines and follow proper handling procedures during assembly.
• Optical Design: The 25-degree viewing angle provides a directed beam. For wider illumination, secondary optics (diffusers, light guides) may be required.

7. Reliability and Quality Assurance

The product undergoes a comprehensive suite of reliability tests conducted with a 90% confidence level and a Lot Tolerance Percent Defective (LTPD) of 10%. Key test items include:

• Reflow Soldering Resistance (260°C/10s).
• Thermal Shock (-10°C to +100°C).
• Temperature Cycling (-40°C to +100°C).
• High Temperature/High Humidity Storage (85°C/85% RH, 1000 hrs with bias).
• High and Low Temperature Storage.
• DC Operation Life Test (1000 hrs at 20 mA).

These tests validate the LED's robustness under various environmental and operational stresses, ensuring it meets industry standards for quality and durability in end products.

8. Technical Comparison and Differentiation

Compared to older through-hole LED technologies, this SMD LED offers significant advantages: a drastically smaller footprint, suitability for high-speed automated assembly, and better thermal performance due to direct mounting on the PCB. Within the SMD LED category, its key differentiators are its specific combination of very high luminous intensity (1232 mcd typ) from a tiny 2.0mm package, a well-defined brilliant red color from AlGaInP technology, and comprehensive compliance with environmental standards (RoHS, REACH, Halogen-Free). The narrow viewing angle makes it superior for applications requiring a directed beam rather than omnidirectional emission.

9. Frequently Asked Questions (FAQ)

9.1 What resistor value should I use to drive this LED at 20 mA from a 5V supply?

Using Ohm's Law: R = (V_supply - V_F) / I_F. With a typical V_F of 2.0V, R = (5V - 2.0V) / 0.020A = 150 Ω. To account for the maximum V_F (2.4V) and ensure the current does not exceed 25 mA, calculate for the worst case: R_min = (5V - 1.7V) / 0.025A = 132 Ω. A standard 150 Ω resistor is a good starting point, providing approximately 20 mA with a typical LED. Always verify the actual current in the circuit.

9.2 Can I use PWM (Pulse Width Modulation) to dim this LED?

Yes, PWM is an effective method for dimming LEDs. The forward current during the "on" pulse should not exceed the peak forward current rating (60 mA at 1/10 duty cycle, 1 kHz). For dimming, ensure the PWM frequency is high enough (typically >100 Hz) to avoid visible flicker.

9.3 Why is the storage and handling procedure so strict?

The plastic resin package can absorb moisture from the air. During the high-temperature reflow soldering process, this trapped moisture can rapidly expand, causing internal delamination or "popcorning," which cracks the package and destroys the LED. The moisture-sensitive level (MSL) and baking procedures prevent this failure mode.

10. Operating Principle and Technology

This LED is based on AlGaInP semiconductor technology. When a forward voltage exceeding the diode's junction potential is applied, electrons and holes are injected into the active region where they recombine. In AlGaInP materials, this recombination releases energy primarily in the form of photons in the red to amber region of the visible spectrum. The specific alloy composition of Aluminum, Gallium, Indium, and Phosphorus determines the precise bandgap energy and thus the dominant wavelength of the emitted light, which is brilliant red in this case. The water-clear epoxy resin lens encapsulates the chip, provides mechanical protection, and shapes the light output beam.