Side-Emitting SMD LED Green 530nm - EIA Standard Package - 20mA - 76mW - Chinese Datasheet

1. Product Overview

This document details the specifications of a high-brightness side-view surface-mount device (SMD) LED. This component utilizes an InGaN semiconductor chip to produce green light. Its design is suitable for automated assembly processes and is compatible with infrared reflow soldering, making it ideal for high-volume production. The LED is packaged in 8mm tape on a 7-inch diameter reel, complying with EIA standard packaging specifications to ensure consistent pick-and-place operations.

1.1 Core Features and Advantages

• High Brightness:Utilizing ultra-high brightness InGaN chip technology.
• Side-Emitting:The encapsulation design emits light from the side, making it highly suitable for backlight applications in slim devices.
• Automation-friendly:Fully compatible with automatic placement equipment and standard infrared reflow soldering temperature profiles.
• Lead-free and RoHS compliant:This device complies with the Restriction of Hazardous Substances (RoHS) Directive.
• Integrated circuit compatible:Can be directly driven by standard integrated circuit outputs.

1.2 Target Applications

This LED is suitable for general indicator and backlight applications in consumer electronics, office equipment, communication devices, and household appliances. Its side-emitting characteristic makes it particularly suitable for edge-lit panels, status indicators on PCBs, and backlighting for LCD displays in portable devices.

2. Technical Specifications and In-depth Analysis

2.1 Absolute Maximum Ratings

These ratings define the limiting conditions beyond which permanent damage to the device may occur. Functional operation under these conditions is not guaranteed.

• Power Dissipation (Pd):76 mW. This is the maximum heat that the LED package can dissipate when the ambient temperature (Ta) is 25°C.
• Continuous Forward Current (IF):20 mA DC. Recommended steady-state operating current.
• Peak forward current:100 mA, allowed only under pulse conditions (1/10 duty cycle, 0.1ms pulse width). This allows for brief, high-intensity flashes.
• Operating temperature range:-20°C to +80°C. The ambient temperature range for reliable operation.
• Storage Temperature Range:-30°C to +100°C.
• Welding Temperature:Can withstand 260°C for 10 seconds, which is a typical requirement for Pb-free reflow processes.

2.2 Photoelectric Characteristics

Unless otherwise specified, these parameters are measured under the conditions of Ta=25°C and IF=20mA. They define the performance under normal operating conditions.

• Luminous Intensity (Iv):The range is from a minimum of 71.0 mcd to a typical maximum of 450.0 mcd. The intensity is measured using a sensor filtered to match the photopic response of the human eye (CIE curve).
• Perspective (2θ_1/2):130 degrees. This is the full angle at which the light intensity drops to half of its peak (axial) value, indicating a very wide emission pattern suitable for side lighting.
• Peak Wavelength (λ_P):530 nm. The wavelength at which the spectral power output reaches its maximum.
• Dominant Wavelength (λ_d):525 nm. This is the single wavelength perceived by the human eye that defines the LED's color, derived from the CIE chromaticity diagram.
• Spectral Bandwidth (Δλ):35 nm. The width of the emission spectrum at half of the maximum intensity (Full Width at Half Maximum - FWHM).
• Forward Voltage (V_F):Typical value 3.2V, range from 2.8V to 3.6V at 20mA. This is the voltage drop when the LED conducts current.
• Reverse Current (I_R):At a reverse voltage (V_R) of 5V, maximum 10 μA.Important Notice:This device is not designed for reverse bias operation; this parameter is for leakage test purposes only.

3. Binning System Description

To ensure production consistency, LEDs are binned according to their performance. This allows designers to select components that meet specific voltage, brightness, and color requirements.

3.1 Forward Voltage Binning

Binning is based on its forward voltage (V_F) at 20mA. The tolerance for each bin is ±0.1V.

• D7:2.80V – 3.00V
• D8:3.00V – 3.20V
• D9:3.20V – 3.40V
• D10:3.40V – 3.60V

3.2 Luminous Intensity Binning

Binning is based on its luminous intensity (I_v) at 20mA. The tolerance for each bin is ±15%.

• Q:71.0 mcd – 112.0 mcd
• R:112.0 mcd – 180.0 mcd
• S:180.0 mcd – 280.0 mcd
• T:280.0 mcd – 450.0 mcd

3.3 Dominant Wavelength Binning

Binning is based on its dominant wavelength (λ_d) at 20mA. The tolerance for each bin is ±1nm.

• AP:520.0 nm – 525.0 nm
• AQ:525.0 nm – 530.0 nm
• AR:530.0 nm – 535.0 nm

4. Analysis of Performance Curves

Although specific charts are referenced in the specification sheet, the typical performance trend can be described as follows:

4.1 Relationship Between Forward Current and Forward Voltage (I-V Curve)

LED yana nuna halayen diode na rashin layi na I-V. Ƙarfin lantarki na gaba yana ƙaruwa da logarithmic tare da ƙarfin lantarki. Yin aiki a ƙarfin lantarki da ya fi shawarar 20mA zai haifar da V_Fda ƙarfin watsi (zafi) su ƙaru ba daidai ba.

4.2 Relationship Between Luminous Intensity and Forward Current

A cikin kewayon aikin da aka shawarce, fitowar haske (ƙarfin haske) kusan yayi daidai da ƙarfin lantarki na gaba. Duk da haka, a cikin ƙarfin lantarki mai tsanani, yuwuwar yin aiki na iya raguwa saboda hauhawar yanayin zafi na junction.

4.3 Temperature Dependence

LED performance is sensitive to temperature. As the junction temperature increases:

• Forward Voltage (V_F):Slightly decreases.
• Luminous intensity (I_v):Decreases. This rate of decrease is a key factor in thermal management design.
• Wavelength (λ_d):May shift slightly, usually towards longer wavelengths (redshift).

5. Mechanical and Packaging Information

5.1 Package Dimensions and Polarity

The LED is housed in an EIA-compliant SMD package. The datasheet includes detailed dimension drawings. The cathode is typically marked, for example by a notch, a green dot, or different lead length/shape. Correct polarity is crucial for operation.

5.2 Recommended PCB Land Pattern

It provides a suggested pad layout to ensure reliable solder joints and correct alignment during the reflow soldering process. Following this pattern helps prevent tombstoning (component lifting on one end) and ensures good thermal and electrical connections.

6. Assembly, Soldering, and Operation Guide

6.1 Reflow Soldering Temperature Profile

Provides recommended infrared reflow soldering temperature profiles suitable for lead-free processes, compliant with JEDEC standards. Key parameters include:

• Preheat:150–200°C, maximum 120 seconds, to gradually heat the circuit board and activate the flux.
• Peak Temperature:Maximum 260°C.
• Time Above Liquidus:The temperature profile should limit the time the LED pins are above the solder's melting point to a maximum of 10 seconds, and the number of reflow cycles should not exceed two.

Note:The optimal temperature profile depends on the specific PCB design, solder paste, and oven. The provided curve is for reference only as a starting point.

6.2 Manual Soldering

If manual soldering is necessary, use a temperature-controlled soldering iron with the maximum temperature set to 300°C. Limit soldering time to within 3 seconds per pin and solder only once.

6.3 Cleaning

If cleaning is required after soldering, use only the specified solvents. Immerse the LED in ethanol or isopropyl alcohol at room temperature for no more than one minute. Do not use ultrasonic cleaning or unspecified chemicals, as they may damage the plastic lens or package.

6.4 Storage and Moisture Sensitivity

LEDs are moisture sensitive. If the original sealed moisture barrier bag (with desiccant) is unopened, it should be stored at ≤30°C and ≤90% relative humidity, and used within one year. Once the bag is opened, the storage environment must not exceed 30°C and 60% relative humidity. Components removed from the original packaging should be reflow soldered within one week. For storage outside the original bag for longer periods, they should be stored in a sealed container with desiccant or in a nitrogen dry cabinet. If stored in an open environment for more than one week, baking is recommended before assembly, at approximately 60°C for at least 20 hours, to remove absorbed moisture and prevent "popcorn" effect during reflow soldering.

6.5 Electrostatic Discharge (ESD) Protection

LED yana da hankali ga zubar da wutar lantarki. A yi aiki a cikin yankin kariya na ESD, amfani da bandeji na wuyan ƙasa, katifar hana tashin hankali, da kwantena masu ɗaukar wutar lantarki. Duk na'urorin dole ne a haɗa su da ƙasa daidai.

7. Packaging and Ordering Information

7.1 Tape and Reel Specifications

LEDs are supplied in 8mm wide embossed carrier tape and sealed with top cover tape. The carrier tape is wound on a standard 7-inch (178mm) diameter reel. Each reel contains 4000 pieces. For quantities less than a full reel, the minimum packaging quantity for the remaining batch is 500 pieces.

7.2 Part Number Structure

Part number LTST-S220TGKT encodes key attributes:

• LTST:Possibly indicates product series (Lite-On SMD LED).
• S220:Possibly indicates package style/size (side-view, 220 mil? - manufacturer-specific).
• TGKT:Possibly indicates color (green), brightness/wavelength/voltage binning codes, and possible tape/reel packaging. The exact decoding method varies by manufacturer.

8. Application Notes and Design Considerations

8.1 Current Limiting

LED is a current-driven device. Always use a series current-limiting resistor or a constant-current drive circuit. The resistor value can be calculated using Ohm's Law: R = (V_{Power Supply}- V_F) / I_F. Use the maximum V_Fvalue (3.6V) from the datasheet to ensure sufficient current under all conditions.

8.2 Thermal Management

Although the power consumption is low (76mW), proper PCB layout is crucial for long-term reliability. Ensure sufficient copper foil area around the LED pads to act as a heat sink, especially when operating at high ambient temperatures or near the maximum current.

8.3 Optical Design

The 130-degree side viewing angle provides broad, diffuse illumination. For applications requiring more focused light, external lenses or light guides may be necessary. Consider the interaction between the LED's emission pattern and adjacent components or the housing.

9. Technical Comparison and Differentiation

The primary differentiating feature of this LED is itsSide-view package和InGaN chip technologyCompared to top-emitting LEDs, it is designed to direct light parallel to the PCB surface, saving vertical space. Compared to older technologies like AlGaAs, InGaN technology achieves high brightness and efficiency in the green/blue spectral region.

10. Frequently Asked Questions (FAQ)

10.1 Can I drive this LED without a current-limiting resistor?

No.Haɗa LED kai tsaye zuwa tushen wutar lantarki zai haifar da wuce gona da iri na halin yanzu, yana lalata kayan aiki nan take. Resistor a jere ko mai daidaita halin yanzu mai aiki ya zama dole.

10.2 What is the difference between peak wavelength and dominant wavelength?

Peak wavelengthIt is the physical peak of the emission spectrum.Dominant WavelengthIt is the perceived color point on the CIE chromaticity diagram. For monochromatic light sources, the two are similar. For LEDs with a certain spectral width, the dominant wavelength is the color perceived by the human eye.

10.3 Why are there storage and baking requirements?

Plastic packaging absorbs moisture from the air. During high-temperature reflow soldering, this trapped moisture rapidly expands into steam, causing internal delamination or cracking ("popcorn" effect). Baking can remove this moisture.

11. Practical Design Example

Scenario:Design a side-emitting status indicator on a 5V digital logic board.

1. Component Selection:Select an LED from the appropriate brightness bin (e.g., medium brightness 'R' bin).
2. Current Setting:Decide to operate at a typical 20mA.
3. Resistance calculation:Use worst-case V_F= 3.6V. R = (5V - 3.6V) / 0.020A = 70 ohms. The closest standard value is 68 ohms. Recalculating current: I = (5V - 3.2V_{Typical value}) / 68Ω ≈ 26.5mA (safe, below absolute maximum DC current).
4. PCB layout:Place the LED according to the recommended land pattern. Add small thermal relief connections to the cathode pad connected to the ground plane to facilitate heat dissipation.
5. Assembly:Follow the lead-free reflow soldering temperature profile. If the moisture-sensitive handling time is exceeded, ensure the circuit board is baked.

12. Working Principle

LED is a semiconductor p-n junction diode. When a forward voltage is applied, electrons from the n-type material recombine with holes from the p-type material in the active region (InGaN chip). This recombination releases energy in the form of photons (light). The specific wavelength (color) of the light is determined by the energy band gap of the semiconductor material used. The energy band gap of InGaN is suitable for producing green, blue, and white light (using phosphors).

13. Technology Trends

The optoelectronics industry continues to advance in several key areas related to such components:

• Efficiency improvement (lm/W):Ongoing improvements in materials science and chip design enable more light output per unit of electrical input power.
• Miniaturization:Package size continues to shrink while maintaining or improving optical performance.
• Color Consistency Improvement:Tighter binning tolerances and advanced manufacturing processes reduce color variation between production batches.
• Higher reliability and lifespan:Better packaging materials and thermal management design extend the operational lifespan, especially under high-temperature conditions.
• Integration:Trends include integrating multiple LED chips (RGB), drivers, or control logic into a single package to enable smarter lighting solutions.

This side-emitting SMD LED represents a mature, reliable component built on proven InGaN technology, optimized for automated assembly, and delivers consistent performance across a wide range of indicator and backlight applications.