SMD LED Yellow 595nm Datasheet - EIA Package - 30mA - 75mW - English Technical Document

1. Product Overview

This document details the specifications for a high-performance, surface-mount yellow LED. The device utilizes an Ultra Bright AlInGaP chip technology, delivering high luminous intensity in a compact, industry-standard package. It is designed for compatibility with automated assembly processes, including infrared reflow soldering, making it suitable for high-volume manufacturing environments. The product is compliant with RoHS directives and is classified as a green product.

2. Technical Parameter Deep Dive

2.1 Absolute Maximum Ratings

The device's operational limits are defined at an ambient temperature (Ta) of 25°C. Exceeding these ratings may cause permanent damage.

• Power Dissipation (Pd): 75 mW. This is the maximum power the LED can dissipate as heat.
• Peak Forward Current (I_F(PEAK)): 80 mA. This is permissible only under pulsed conditions (1/10 duty cycle, 0.1ms pulse width) to prevent overheating.
• Continuous Forward Current (I_F): 30 mA DC. This is the recommended maximum current for continuous operation.
• Derating: The maximum forward current must be linearly reduced by 0.4 mA for every degree Celsius above 50°C ambient temperature to maintain reliability.
• Reverse Voltage (V_R): 5 V. Applying a higher reverse voltage can damage the LED's semiconductor junction.
• Operating & Storage Temperature Range: -55°C to +85°C.
• Infrared Soldering Condition: Withstands 260°C peak temperature for 5 seconds, compatible with lead-free (Pb-free) processes.

2.2 Electrical & Optical Characteristics

Key performance parameters are measured at Ta=25°C and a forward current (I_F) of 20 mA, unless otherwise stated.

• Luminous Intensity (I_V): Ranges from a minimum of 18.0 mcd to a typical value of 50.0 mcd. This is the perceived brightness as measured by a sensor filtered to match the human eye's photopic response (CIE curve).
• Viewing Angle (2θ_1/2): 130 degrees. This wide viewing angle indicates the LED emits light over a broad area, with the half-intensity points located 65 degrees off the central axis.
• Peak Emission Wavelength (λ_P): 595 nm. This is the wavelength at which the spectral power output is highest.
• Dominant Wavelength (λ_d): 592 nm. This is the single wavelength that best represents the perceived color of the LED, derived from CIE chromaticity calculations.
• Spectral Line Half-Width (Δλ): 16 nm. This parameter indicates the spectral purity; a smaller value means a more monochromatic light source.
• Forward Voltage (V_F): Typically 2.4 V, with a maximum of 2.4 V at 20 mA. This is the voltage drop across the LED when conducting current.
• Reverse Current (I_R): Maximum 10 µA when a 5V reverse bias is applied.
• Capacitance (C): Typically 40 pF measured at 0V bias and 1 MHz frequency.

3. Binning System Explanation

The luminous intensity of the LEDs is sorted into bins to ensure consistency within a production batch. The bin code defines the minimum and maximum intensity range.

• Bin Code M: 18.0 - 28.0 mcd
• Bin Code N: 28.0 - 45.0 mcd
• Bin Code P: 45.0 - 71.0 mcd
• Bin Code Q: 71.0 - 112.0 mcd
• Bin Code R: 112.0 - 180.0 mcd

A tolerance of +/-15% is applied to each intensity bin. This system allows designers to select LEDs with predictable brightness levels for their application.

4. Performance Curve Analysis

While specific graphs are referenced in the datasheet (e.g., Fig.1, Fig.6), typical curves for such devices include:

• I-V (Current-Voltage) Curve: Shows the exponential relationship between forward voltage and current. The curve will have a characteristic "knee" voltage around 2.0-2.4V.
• Luminous Intensity vs. Forward Current: Intensity generally increases linearly with current up to a point, after which efficiency may drop due to heating.
• Luminous Intensity vs. Ambient Temperature: Intensity typically decreases as ambient temperature rises due to reduced internal quantum efficiency and increased non-radiative recombination.
• Spectral Distribution: A plot of relative radiant power versus wavelength, peaking at 595nm with a 16nm half-width, confirming the yellow color emission.
• Viewing Angle Pattern: A polar plot illustrating the angular distribution of light intensity, confirming the 130-degree full viewing angle.

5. Mechanical & Packaging Information

5.1 Package Dimensions

The LED is housed in an industry-standard EIA package. All dimensions are in millimeters with a general tolerance of ±0.10 mm unless otherwise specified. The package features a water-clear lens.

5.2 Polarity Identification & Pad Design

The datasheet includes a suggested soldering pad layout to ensure proper solder joint formation and mechanical stability during reflow. The cathode is typically identified by a visual marker on the package, such as a notch, green marking, or a shorter lead. The recommended pad design helps prevent tombstoning and ensures correct alignment.

6. Soldering & Assembly Guidelines

6.1 Reflow Soldering Profile

A recommended infrared (IR) reflow profile is provided for lead-free (SnAgCu) solder paste processes. Key parameters include:

• Preheat: Ramp-up to 120-150°C.
• Soak/Preheat Time: Maximum 120 seconds to activate flux and equalize board temperature.
• Peak Temperature: Maximum 240°C.
• Time Above Liquidus: A specific duration (implied by the profile) to ensure proper solder joint formation without overheating the component.
• Critical Limit: The component body must not exceed 260°C for more than 5 seconds.

6.2 Hand Soldering

If hand soldering is necessary:

• Iron tip temperature should not exceed 300°C.
• Soldering time per lead should be limited to a maximum of 3 seconds.
• This should be performed only once to avoid thermal stress on the package.

6.3 Cleaning

Only specified cleaning agents should be used. Recommended solvents are ethyl alcohol or isopropyl alcohol at normal room temperature. The LED should be immersed for less than one minute. Unspecified chemicals may damage the plastic lens or package material.

6.4 Storage Conditions

• Recommended storage ambient: ≤30°C and ≤70% relative humidity.
• LEDs removed from their original moisture-barrier packaging should be reflow-soldered within 672 hours (28 days) to prevent moisture absorption.
• For extended storage outside the original bag, use a sealed container with desiccant or a nitrogen desiccator.
• Components stored out of bag for more than 672 hours require a baking pre-treatment (approximately 60°C for at least 24 hours) before soldering to drive out absorbed moisture and prevent "popcorning" during reflow.

7. Packaging & Ordering Information

7.1 Tape and Reel Specifications

The LEDs are supplied in 8mm carrier tape on 7-inch (178mm) diameter reels, compatible with standard automated pick-and-place equipment.

• Pieces per Reel: 3000.
• Minimum Order Quantity (MOQ) for Remainders: 500 pieces.
• Cover Tape: Empty component pockets in the carrier tape are sealed with a top cover tape.
• Missing Components: A maximum of two consecutive missing LEDs ("skips") is allowed per reel specification.
• The packaging conforms to the ANSI/EIA 481-1-A-1994 standard.

8. Application Recommendations

8.1 Typical Application Scenarios

This LED is suitable for general illumination and indication purposes in ordinary electronic equipment, including but not limited to:

• Status indicators on consumer electronics (TVs, routers, chargers).
• Backlighting for buttons, switches, or small panels.
• Decorative lighting in appliances.
• Signage and display elements.

Important Note: It is not recommended for safety-critical applications (e.g., aviation, medical life-support, transportation control) without prior consultation and qualification, as failure could jeopardize life or health.

8.2 Circuit Design Considerations

Drive Method: LEDs are current-operated devices. To ensure uniform brightness when driving multiple LEDs in parallel, it is strongly recommended to use an individual current-limiting resistor in series with each LED (Circuit Model A).

• Circuit Model A (Recommended): Vcc → Resistor → LED → GND. This compensates for minor variations in the forward voltage (V_F) of individual LEDs, ensuring each receives nearly the same current and thus emits similar brightness.
• Circuit Model B (Not Recommended for Parallel): Connecting multiple LEDs directly in parallel to a single current-limiting resistor (Vcc → Resistor → [LED1 // LED2 // ...] → GND) is discouraged. Small differences in V_F can cause significant current imbalance, where the LED with the lowest V_F hogs most of the current, appearing brighter and potentially being overstressed, while others appear dimmer.

The resistor value (R) can be calculated using Ohm's Law: R = (V_supply - V_F) / I_F, where V_F is the typical forward voltage (e.g., 2.4V) and I_F is the desired operating current (e.g., 20mA).

9. Electrostatic Discharge (ESD) Protection

The LED is sensitive to electrostatic discharge. ESD can cause latent or catastrophic damage, degrading performance or causing immediate failure.

Symptoms of ESD Damage: High reverse leakage current, abnormally low forward voltage (V_F), or failure to illuminate at low drive currents.

ESD Prevention Measures:

• Operators should wear a grounded wrist strap or anti-static gloves.
• All equipment, workbenches, and storage racks must be properly grounded.
• Use an ionizer to neutralize static charges that may accumulate on the LED lens due to handling friction.
• Handle components in an ESD-protected area (EPA).

Testing for ESD Damage: Check for illumination and measure V_F at a very low current (e.g., 0.1mA). For this AlInGaP product, a "good" LED should have a V_F > 1.4V at 0.1mA.

10. Technical Comparison & Differentiation

This LED differentiates itself through several key features:

• Chip Technology: Uses AlInGaP (Aluminum Indium Gallium Phosphide), which is known for high efficiency and stability in the red, orange, amber, and yellow color spectrum, compared to older technologies like GaAsP.
• Brightness: Offers high luminous intensity (up to 180 mcd in the highest bin) from a small package.
• Wide Viewing Angle: The 130-degree viewing angle provides broad, even illumination ideal for panel indicators.
• Process Compatibility: Fully compatible with automated SMT assembly and lead-free IR reflow soldering, reducing manufacturing complexity and cost.
• Standardization: The EIA-standard package footprint ensures easy second-sourcing and design portability.

11. Frequently Asked Questions (FAQs)

Q1: What is the difference between Peak Wavelength (λ_P) and Dominant Wavelength (λ_d)?
A1: Peak Wavelength is the physical point of highest spectral output. Dominant Wavelength is a calculated value representing the perceived color as defined by the CIE chromaticity diagram. They are often close but not identical.

Q2: Can I drive this LED at its maximum peak current (80mA) continuously?
A2: No. The 80mA rating is for very short pulses (0.1ms width) at a low duty cycle (10%). Continuous operation must not exceed the DC forward current rating of 30mA, and this should be derated above 50°C ambient temperature.

Q3: Why is an individual series resistor needed for each LED in parallel?
A3: It provides negative feedback, stabilizing the current. If one LED has a slightly lower V_F, the voltage drop across its resistor increases slightly, limiting the current rise and balancing brightness across all LEDs.

Q4: How critical is the 672-hour floor life after opening the moisture barrier bag?
A4: It is very important for process reliability. Absorbed moisture can vaporize rapidly during reflow, causing internal delamination or cracking ("popcorning"). Adhering to this guideline or performing a bake cycle is essential for high yield.

12. Design-in Case Study

Scenario: Designing a control panel with 10 yellow status indicators. The system power supply is 5V.

Design Steps:

1. Current Selection: Choose a drive current. For a balance of brightness and longevity, 20mA is selected from the datasheet test condition.
2. Circuit Topology: To ensure uniform brightness, use Circuit Model A: one resistor per LED.
3. Resistor Calculation: Using typical V_F = 2.4V, V_supply = 5V, I_F = 0.020A.
   R = (5V - 2.4V) / 0.020A = 2.6V / 0.02A = 130 Ω.
   The nearest standard 5% resistor value is 130 Ω or 120 Ω. Using 120 Ω would yield I_F ≈ (5-2.4)/120 = 21.7mA, which is acceptable.
4. Power Rating for Resistor: P = I² * R = (0.020)² * 120 = 0.048W. A standard 1/8W (0.125W) or 1/10W resistor is more than sufficient.
5. Layout: Follow the suggested soldering pad dimensions from the datasheet for optimal solder fillets and mechanical strength.
6. Assembly: Follow the recommended IR reflow profile. Ensure components are used within the 672-hour floor life or are baked accordingly.

13. Technology Principle Introduction

This LED is based on AlInGaP semiconductor material grown on a substrate. When a forward voltage is applied, electrons and holes are injected into the active region where they recombine. In a direct bandgap semiconductor like AlInGaP, this recombination often releases energy in the form of photons (light) – a process called electroluminescence. The specific wavelength of the emitted light (yellow, ~592-595nm) is determined by the bandgap energy of the AlInGaP alloy composition. The water-clear epoxy lens encapsulates the chip, provides mechanical protection, and shapes the light output beam (in this case, for a wide viewing angle).

14. Industry Trends

The market for SMD LEDs continues to evolve. General trends observable in components like this one include:

• Increased Efficiency: Ongoing improvements in epitaxial growth and chip design yield higher luminous efficacy (more light output per electrical watt).
• Miniaturization: While this is a standard package, the industry pushes for smaller footprints (e.g., 0402, 0201) for space-constrained applications.
• Enhanced Reliability: Improved packaging materials and processes lead to longer operational lifetimes and better performance under thermal and environmental stress.
• Standardization & Compatibility: Adherence to global standards (EIA, JEDEC) and process compatibility (lead-free, reflow) remains critical for seamless integration into modern electronics manufacturing.
• Color Consistency: Tighter binning specifications and advanced phosphor technologies (for white LEDs) are demanded for applications requiring precise color matching.