Reverse Mount SMD LED Blue Datasheet - EIA Package - 5mA - 45mcd - English Technical Document

1. Product Overview

This document details the specifications for a reverse mount, surface-mount device (SMD) light-emitting diode (LED) utilizing an Indium Gallium Nitride (InGaN) semiconductor material to produce blue light. The device features a water-clear lens and is packaged in a standard EIA-compliant format. It is designed for automated assembly processes, including pick-and-place equipment and infrared (IR) reflow soldering, making it suitable for high-volume manufacturing. The LED is classified as a green product, complying with RoHS (Restriction of Hazardous Substances) directives.

1.1 Core Advantages

• Reverse Mount Design: The chip is mounted in a specific orientation that is optimized for certain PCB layouts and light extraction.
• Automation Compatibility: Supplied on 8mm tape on 7-inch reels, fully compatible with standard automated placement and soldering equipment.
• High ESD Tolerance: Features an 8000V Electrostatic Discharge (ESD) threshold tested using the Human Body Model (HBM), offering good handling robustness.
• IC Compatible: Electrical characteristics allow for direct drive from standard logic-level integrated circuit outputs.
• Pb-Free Process Compatible: Withstands infrared reflow soldering profiles required for lead-free assembly.

2. In-Depth Technical Parameter Analysis

The following section provides a detailed breakdown of the device's absolute limits and operational characteristics. All parameters are specified at an ambient temperature (Ta) of 25°C unless stated otherwise.

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.

• Power Dissipation (Pd): 76 mW. The maximum total power the device can dissipate as heat.
• Peak Forward Current (I_FP): 100 mA. Permissible under pulsed conditions (1/10 duty cycle, 0.1ms pulse width).
• DC Forward Current (I_F): 20 mA. The maximum continuous forward current for reliable operation.
• Operating Temperature Range (T_opr): -20°C to +80°C.
• Storage Temperature Range (T_stg): -30°C to +100°C.
• Infrared Soldering Condition: Withstands 260°C peak temperature for 10 seconds, typical for lead-free reflow processes.

2.2 Electrical & Optical Characteristics

These are the typical performance parameters under standard test conditions (I_F = 5 mA, Ta=25°C).

• Luminous Intensity (I_V): Ranges from a minimum of 11.2 mcd to a maximum of 45.0 mcd. The typical value depends on the specific bin (see Section 3). Measured with a sensor filtered to the CIE photopic eye-response curve.
• Viewing Angle (2θ_1/2): 130 degrees. This wide viewing angle indicates a diffuse, non-focused light emission pattern, suitable for indicator and backlighting applications requiring wide angular visibility.
• Peak Emission Wavelength (λ_P): 468 nm. The specific wavelength at which the spectral power output is highest.
• Dominant Wavelength (λ_d): 465.0 nm to 475.0 nm. This is the single wavelength perceived by the human eye to define the color. It is derived from the CIE chromaticity diagram.
• Spectral Line Half-Width (Δλ): 25 nm. This parameter indicates the spectral purity or bandwidth of the emitted light. A value of 25nm is typical for a standard blue InGaN LED.
• Forward Voltage (V_F): 2.65 V to 3.15 V. The voltage drop across the LED when driven at 5 mA. This range must be considered for current-limiting resistor calculation in circuit design.
• Reverse Current (I_R): 10 μA maximum when a reverse voltage (V_R) of 0.55V is applied. Important Note: The device is not designed for operation under reverse bias; this test condition is for leakage characterization only.

3. Binning System Explanation

To ensure consistency in production, LEDs are sorted into bins based on key parameters. This allows designers to select parts that meet specific application requirements for color and brightness uniformity.

3.1 Forward Voltage Binning

Bins ensure LEDs have similar voltage drops, which can simplify power supply design in parallel arrays. Tolerance per bin is ±0.1V.

• Bin 1: 2.65V - 2.75V
• Bin 2: 2.75V - 2.85V
• Bin 3: 2.85V - 2.95V
• Bin 4: 2.95V - 3.05V
• Bin 5: 3.05V - 3.15V

3.2 Luminous Intensity Binning

This binning groups LEDs by their brightness output at 5 mA. Tolerance per bin is ±15%.

• L1: 11.2 mcd - 14.0 mcd
• L2: 14.0 mcd - 18.0 mcd
• M1: 18.0 mcd - 22.4 mcd
• M2: 22.4 mcd - 28.0 mcd
• N1: 28.0 mcd - 35.5 mcd
• N2: 35.5 mcd - 45.0 mcd

3.3 Dominant Wavelength Binning

This controls the perceived color (hue) of the blue light. Tolerance per bin is ±1 nm.

• Bin AC: 465.0 nm - 470.0 nm (slightly greener blue)
• Bin AD: 470.0 nm - 475.0 nm (slightly purer blue)

4. Performance Curve Analysis

While specific graphical curves are referenced in the datasheet (e.g., Fig.1, Fig.6), their implications are critical for design.

4.1 Luminous Intensity vs. Forward Current

The light output (I_V) is approximately proportional to the forward current (I_F) within the operating range. Driving the LED above 5 mA will increase brightness but also increase power dissipation and junction temperature, which can affect longevity and wavelength. The 20 mA DC maximum provides a significant brightness headroom from the 5 mA test point.

4.2 Forward Voltage vs. Forward Current & Temperature

The V_F of a diode has a negative temperature coefficient; it decreases as the junction temperature increases. This characteristic is important for constant-current drive designs, as a fixed voltage source could lead to thermal runaway if not properly current-limited. The specified V_F range at 25°C must be used as a guideline, understanding it will shift with operating temperature.

4.3 Spectral Distribution

The referenced spectral graph (Fig.1) would show a Gaussian-like distribution centered at the peak wavelength of 468 nm, with a full width at half maximum (FWHM) of 25 nm. This spectral width is relevant for applications sensitive to specific wavelengths, such as sensors or color-mixed lighting systems.

5. Mechanical & Package Information

5.1 Package Dimensions and Polarity

The device conforms to a standard EIA package outline. The "reverse mount" designation is crucial for PCB footprint design. The cathode and anode are located on specific sides of the package. The mechanical drawing provides exact dimensions (in mm) for land pattern design, including pad size and spacing to ensure proper soldering and alignment. The tolerance for most dimensions is ±0.10 mm.

5.2 Suggested Soldering Pad Layout

A recommended PCB land pattern (solder pad geometry) is provided to ensure reliable solder joint formation during reflow. Adhering to this pattern helps prevent tombstoning (component standing on end) and ensures proper thermal and electrical connection.

6. Soldering & Assembly Guidelines

6.1 IR Reflow Soldering Profile

A suggested reflow profile for lead-free (Pb-free) processes is included. Key parameters include:

• Pre-heat: 150–200°C range.
• Pre-heat Time: Maximum 120 seconds to allow for temperature stabilization and flux activation.
• Peak Temperature: Maximum 260°C.
• Time Above Liquidus: The device can withstand the peak temperature for a maximum of 10 seconds. Reflow should be performed a maximum of two times.

Note: The profile must be characterized for the specific PCB assembly, as board thickness, component density, and solder paste affect thermal transfer.

6.2 Hand Soldering

If manual soldering is necessary:

• Iron Temperature: Maximum 300°C.
• Soldering Time: Maximum 3 seconds per lead.
• Frequency: Should be performed only once to avoid thermal stress.

6.3 Cleaning

If post-solder cleaning is required:

• Use only specified solvents: ethyl alcohol or isopropyl alcohol at normal room temperature.
• Immersion time should be less than one minute.
• Unspecified chemicals may damage the LED package material (epoxy lens).

7. Storage & Handling

7.1 ESD Precautions

Despite the 8000V HBM rating, standard ESD precautions are recommended: use grounded wrist straps, anti-static mats, and properly grounded equipment when handling.

7.2 Moisture Sensitivity

The device has a Moisture Sensitivity Level (MSL) rating of 2a.

• Sealed Bag: Store at ≤30°C and ≤90% RH. Shelf life is one year when stored in the original moisture-barrier bag with desiccant.
• After Opening: Store at ≤30°C and ≤60% RH. Devices should be subjected to IR reflow within 672 hours (28 days) of exposure to ambient factory conditions.
• Extended Storage (Opened): Store in a sealed container with desiccant or in a nitrogen desiccator.
• Rebaking: If exposed for more than 672 hours, bake at approximately 60°C for at least 20 hours before soldering to remove absorbed moisture and prevent "popcorning" during reflow.

8. Packaging & Ordering

8.1 Tape and Reel Specifications

• Carrier Tape Width: 8 mm.
• Reel Diameter: 7 inches.
• Quantity per Reel: 3000 pieces.
• Minimum Order Quantity (MOQ): 500 pieces for remainder quantities.
• Pocket Coverage: Empty pockets are sealed with cover tape.
• Missing Components: A maximum of two consecutive missing LEDs is allowed per specification (ANSI/EIA 481).

9. Application Notes & Design Considerations

9.1 Typical Application Scenarios

• Status Indicators: On consumer electronics, appliances, and industrial control panels, benefiting from the wide viewing angle.
• Backlighting: For small LCD displays, keypads, or membrane switches.
• Decorative Lighting: In low-power accent lighting or signage.
• Sensor Activation: As a light source for optical sensors (proximity, object detection).

Important Disclaimer: This LED is intended for ordinary electronic equipment. It is not rated or recommended for safety-critical applications (e.g., aviation, medical life-support, transportation control) where failure could risk life or health.

9.2 Circuit Design Considerations

1. Current Limiting: Always use a series resistor or constant-current driver. Calculate the resistor value using the maximum V_F from the bin (e.g., 3.15V) and the minimum supply voltage to ensure the current never exceeds the absolute maximum rating, even under worst-case conditions.
2. Thermal Management: While power dissipation is low, ensure adequate PCB copper or thermal relief if operating near maximum current or in high ambient temperatures to maintain junction temperature within limits.
3. Reverse Voltage Protection: As the device is not designed for reverse bias, consider adding a protection diode in parallel (cathode to anode) if the LED could be exposed to reverse voltage transients in the circuit.

10. Frequently Asked Questions (FAQs)

10.1 What does "reverse mount" mean?

Reverse mount refers to the physical orientation of the LED semiconductor chip within the package. In a standard LED, light emits primarily from the top. In a reverse mount design, the chip is oriented to optimize light emission from the sides or through the PCB, often used when the LED is mounted in a cavity or requires a specific optical path. The PCB footprint will differ from a standard top-view LED.

10.2 Ina iya fitar da wannan LED a 20 mA a ci gaba?

Yes, 20 mA is the absolute maximum continuous DC forward current rating. For optimal longevity and stable performance, it is common practice to drive LEDs below their absolute maximum, often at 10-15 mA. Always refer to the derating curves (if available) for operation at high ambient temperatures.

10.3 Yaya zan fassara ƙimar ƙarfin haske?

Luminous intensity (mcd) ma'auni ne na haske da ake gani a takamaiman shugabanci (tare da axis). Kallon kusurwar digiri 130 yana nufin ana kiyaye wannan haske a kan mazugi mai faɗi sosai. Don aikace-aikacen da ke buƙatar hasken da aka mai da hankali, ana buƙatar na'urorin gani na biyu (ruwan tabarau). Tsarin binning (L1 zuwa N2) yana ba ku damar zaɓar mafi ƙarancin haske don ƙirarku.

10.4 Me ya sa yanayin ajiya yake da mahimmanci haka?

SMD components absorb moisture from the air. During the high-temperature reflow soldering process, this trapped moisture can vaporize rapidly, causing internal delamination, cracking, or "popcorning," which destroys the component. The MSL rating and baking instructions are critical for assembly yield and reliability.

11. Misalin Zane na Aiki

Scenario: Designing a simple power-on indicator for a 5V circuit.

1. Select Bin: Choose an intensity bin (e.g., M1 for 18-22.4 mcd) and a voltage bin (e.g., Bin 3 for ~2.9V) for calculation.
2. Calculate Series Resistor: Target I_F = 10 mA for a balance of brightness and longevity.
   R = (V_supply - V_F) / I_F = (5V - 2.9V) / 0.01A = 210 Ω.
   Use a standard 220 Ω resistor. Verify power rating: P_R = I²R = (0.01)² * 220 = 0.022W, so a 1/10W or 1/8W resistor is sufficient.
3. PCB Layout: Use the suggested soldering pad dimensions from the datasheet. Ensure polarity is correct according to the package marking diagram.
4. Assembly: Follow the recommended IR reflow profile. If boards are assembled in a humid environment and not used immediately, consider baking the LEDs before assembly if they have been out of the sealed bag for over 28 days.

12. Technology Introduction

This LED is based on InGaN (Indium Gallium Nitride) semiconductor technology grown on a substrate, typically sapphire or silicon carbide. When a forward voltage is applied, electrons and holes recombine in the active quantum well region, releasing energy in the form of photons. The specific ratio of indium to gallium in the alloy determines the bandgap energy and thus the peak wavelength of the emitted light, which in this case is in the blue spectrum (~468 nm). The water-clear epoxy lens encapsulates the chip, providing mechanical protection, shaping the light output (130-degree viewing angle), and enhancing light extraction efficiency.

13. Industry Trends

The development of blue LEDs, for which the 2014 Nobel Prize in Physics was awarded, was a foundational breakthrough enabling white LEDs (via phosphor conversion) and full-color displays. Current trends in SMD LEDs like this one focus on:

• Increased Efficiency: Higher luminous efficacy (more light output per electrical watt input).
• Miniaturization: Smaller package sizes (e.g., 0201, 01005) for denser electronics.
• Improved Color Consistency: Tighter binning tolerances for dominant wavelength and intensity, crucial for applications like display backlighting.
• Enhanced Reliability: Higher maximum operating temperatures and improved moisture resistance for automotive and industrial applications.
• Advanced Packaging: Integration of multiple LED chips (RGB, white) into a single package, or packages with built-in current limiting resistors or control ICs ("smart LEDs").