RF-AU0402TS-EB-B Amber LED Specifications - Size 1.0x0.5x0.4mm - Voltage 1.6-2.6V - Power 26mW - English Technical Data

1. Product Overview

1.1 General Description

The RF-AU0402TS-EB-B is an amber colored surface-mount LED fabricated using a high-efficiency amber chip. Its ultra-compact package dimensions of 1.0mm x 0.5mm x 0.4mm make it one of the smallest commercially available amber LEDs, suitable for space-constrained applications. The device is designed for automated SMT assembly and reflow soldering processes, offering excellent compatibility with modern PCB assembly lines.

1.2 Features

• Extremely wide viewing angle of 140 degrees, ensuring uniform light distribution over a broad area.
• Suitable for all SMT assembly and solder processes, including reflow and hand soldering.
• Moisture sensitivity level: Level 3 per JEDEC standard, requiring proper handling after bag opening.
• RoHS compliant, free from hazardous substances, meeting global environmental regulations.
• Low forward current operation (typical 5mA) enables low power consumption in battery-powered devices.
• Available in multiple brightness and wavelength bins for fine-tuned matching in applications requiring consistency.

1.3 Applications

• Optical indicators: status indicators, backlight for switches, and symbol displays.
• Display backlighting: small LCD or keypad backlights where space is limited.
• General purpose: toy lighting, decorative illumination, and portable electronics.

2. Technical Parameters

2.1 Electrical and Optical Characteristics

All parameters are measured at a solder pad temperature (Ts) of 25°C and a forward current of 5mA unless otherwise noted. The following key characteristics define the performance of this LED:

• Spectral Half Bandwidth (Δλ): Typical 15nm, indicating a relatively narrow emission spectrum centered around the amber wavelength region.
• Forward Voltage (VF): Ranges from 1.6V to 2.6V depending on bin code (A1 to E2). Binning is performed at 5mA, with each bin spanning 0.1V steps. The low forward voltage enables operation from low-voltage supplies.
• Dominant Wavelength (λD): Available in two ranges: A10 (600-602.5nm) and A20 (602.5-605nm), with additional bins B10 (605-607.5nm), B20 (607.5-610nm). This allows selection of exact amber hue.
• Luminous Intensity (IV): Binned into five ranges: A00 (8-12mcd), B00 (12-18mcd), C00 (18-28mcd), D00 (28-43mcd), and E00 (43-65mcd). Higher intensity bins are suitable for applications demanding greater brightness.
• Viewing Angle (2θ1/2): 140 degrees typical, providing a very wide radiation pattern for uniform illumination over a large area.
• Reverse Current (IR): Maximum 10μA at VR=5V, ensuring very low leakage in reverse bias.
• Thermal Resistance (RTHJ-S): Maximum 450°C/W, junction-to-solder point. This relatively high thermal resistance is typical for small package LEDs and necessitates careful thermal management when operating at higher currents.

2.2 Absolute Maximum Ratings

The absolute maximum ratings must not be exceeded, even momentarily, to prevent permanent damage:

• Power Dissipation (Pd): 26 mW
• Forward Current (IF): 10 mA (continuous); 60 mA for pulse operation at 1/10 duty cycle and 0.1ms pulse width.
• ESD Withstand (HBM): 2000 V
• Operating Temperature (Topr): -40°C to +85°C
• Storage Temperature (Tstg): -40°C to +85°C
• Junction Temperature (Tj): 95°C maximum

These limits are based on standardized measurements at Refond's laboratory. The actual maximum current may need to be derated based on thermal conditions; junction temperature must not exceed 95°C.

2.3 Binning System

The LED is sorted into multiple bins to provide tight control over forward voltage, dominant wavelength, and luminous intensity. This allows customers to select devices with consistent performance for their specific requirements. For forward voltage, bins A1 through E2 cover 1.6V to 2.6V in 0.1V increments. For wavelength, bins A10, A20, B10, B20 cover the range 600nm to 610nm in 2.5nm steps. Intensity bins A00 through E00 provide options from 8 mcd to 65 mcd. The bin code is clearly marked on the reel label for traceability.

3. Performance Curves Analysis

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

The I-V characteristic curve (Fig 1-6) shows the typical exponential relationship between forward voltage and forward current. At 5mA the forward voltage is approximately 2.0V for the typical bin. As current increases, the voltage rises slightly due to series resistance. The curve helps designers select appropriate current-limiting resistors for a given supply voltage.

3.2 Forward Current vs. Relative Intensity

Fig 1-7 illustrates that relative luminous intensity increases linearly with forward current in the low current region, but begins to saturate at higher currents. Operating at 5mA yields approximately 50% of the intensity at 10mA, providing a good balance between brightness and thermal dissipation.

3.3 Temperature Effects

Fig 1-8 and Fig 1-9 show how pin temperature affects relative intensity and forward current. As the junction temperature rises, the luminous intensity decreases gradually. For example, at 85°C the intensity may drop to about 80% of its value at 25°C. Thermal management is crucial when driving the LED near its maximum current or in high ambient temperatures.

3.4 Forward Current vs. Dominant Wavelength

Fig 1-10 demonstrates that the dominant wavelength shifts slightly with forward current (approximately 1-2nm over the operating range). This effect is minimal for most indicator applications but should be considered when precise color matching is required.

3.5 Spectral Distribution and Radiation Pattern

Fig 1-11 shows the relative spectral intensity versus wavelength, peaking around 600-610nm with a half-width of 15nm. The radiation pattern (Fig 1-12) indicates a very wide emission angle of 140 degrees, with nearly uniform intensity up to ±70 degrees from the optical axis.

4. Mechanical and Packaging Information

4.1 Package Dimensions

The LED is housed in a standard 0402 SMD package with dimensions 1.0mm length, 0.5mm width, and 0.4mm height. The package has two terminals: anode (marked with a polarity indicator) and cathode. Drawings in the datasheet (Fig 1-1 to 1-3) show top, bottom, and side views with tolerance of ±0.2mm unless otherwise specified.

4.2 Soldering Pad Design

Recommended soldering patterns (Fig 1-5) are provided to ensure reliable solder joints and proper heat dissipation. The pad dimensions are 0.5mm x 0.6mm for each terminal with a spacing of 0.6mm between them. It is critical to match the pad design to the package footprint to avoid tombstoning or weak joints.

4.3 Polarity Mark

The cathode is identified by a small mark on the package (Fig 1-4). The anode is the larger pad on the bottom. Proper polarity must be observed to avoid reverse bias damage.

4.4 Carrier Tape and Reel Dimensions

The LEDs are supplied in embossed carrier tape with a width of 8mm and a pitch of 2.0mm. Each reel holds 4,000 pieces. The tape features a top cover tape and a feeding direction polarity marking. Reel dimensions: outer diameter 178±1mm, width 8.0±0.1mm, hub diameter 60±1mm, and spindle hole 13.0±0.5mm.

4.5 Label Information

The reel label includes part number, specification number, lot number, bin code (for forward voltage, wavelength, and intensity), quantity, and date code. This ensures full traceability.

5. Soldering and Assembly Guidelines

5.1 Reflow Soldering Profile

The recommended reflow soldering profile is provided in Fig 3-1 and Table 3-1. Key parameters: preheat from 150°C to 200°C for 60-120 seconds; ramp-up rate ≤3°C/s; time above 217°C (TL) up to 60s; peak temperature (TP) 260°C for up to 10 seconds; cooling rate ≤6°C/s. Only two reflow cycles are allowed; if more than 24 hours elapse between cycles, the LEDs may absorb moisture and be damaged.

5.2 Hand Soldering and Repair

Hand soldering is permissible with iron temperature ≤300°C and duration ≤3 seconds, done only once. For repair, a double-head soldering iron is recommended to avoid thermal stress on the LED.

5.3 Cautions During Assembly

Do not mount LEDs on warped PCB sections or apply mechanical stress during or after soldering. Avoid rapid cooling after reflow. Ensure proper alignment to avoid short circuits.

6. Storage and Handling

6.1 Storage Conditions

Before opening the moisture barrier bag, store at ≤30°C and ≤75% RH for up to 1 year from the date of sealing. After opening, the LEDs must be used within 168 hours under ≤30°C and ≤60% RH. If storage time is exceeded, bake at 60±5°C for >24 hours before use.

6.2 Moisture Sensitivity

MSL Level 3 requires careful handling. If the bag is damaged or the desiccant has expired, baking is mandatory to prevent popcorn cracking during reflow.

6.3 ESD Protection

LEDs are sensitive to electrostatic discharge (ESD) and electrical overstress (EOS). Use grounded workstations, wrist straps, and ionizers. The HBM rating is 2000V, but proper ESD precautions are still recommended.

6.4 Environmental Considerations

The LED can be affected by sulfur and halogens in the environment. Sulfur compounds should be limited to <100ppm. Bromine <900ppm, Chlorine <900ppm, total halogens <1500ppm. Volatile organic compounds (VOCs) can penetrate silicone encapsulant and cause discoloration. Use only compatible materials in the fixture.

7. Application Notes

7.1 Current Limiting Resistor

Always use a series resistor to limit forward current to the desired level, as LEDs have a steep I-V curve. For a 5mA typical operating current, choose a resistor value that ensures current remains below 10mA absolute maximum even with worst-case supply voltage variation.

7.2 Thermal Management

Thermal design is critical. The thermal resistance of 450°C/W means that at 5mA and 2V, the power dissipation is 10mW, causing a temperature rise of approximately 4.5°C above ambient. At higher currents, the temperature rise increases proportionally. Adequate copper area on the PCB or forced air may be needed.

7.3 Circuit Design Considerations

Protection against reverse voltage is necessary; ensure that the circuit never applies reverse bias to the LED (e.g., during power off transitions). Also, avoid exceeding the absolute maximum rating for forward current, even momentarily.

8. Frequently Asked Questions

8.1 What is the recommended operating current?

The typical current is 5mA, which gives good brightness while staying well within the 10mA absolute maximum. For higher brightness, up to 10mA is allowed but with proper heat sinking to keep junction below 95°C.

8.2 How to select the correct forward voltage bin?

Choose a bin that matches your supply voltage minus resistor drop. For example, if supply is 3.3V and you want 5mA with a 300Ω resistor (drop ~1.5V), you need VF around 1.8V, which corresponds to bin B1 or B2.

8.3 Can I drive this LED directly from a microcontroller GPIO?

Most GPIO pins can source 5-10mA at 3.3V. With a proper series resistor, yes. But check the microcontroller's current capability; if insufficient, use a transistor driver.

8.4 How many reflow cycles are allowed?

Maximum two reflow cycles. If more than 24 hours pass between cycles, bake the LEDs before the second reflow to remove absorbed moisture.

9. Working Principle

This amber LED is a semiconductor light-emitting diode based on an amber chip (likely InGaAlP or GaAsP material). When forward biased, electrons and holes recombine in the active region, emitting photons with energy corresponding to amber light (600-610nm). The narrow spectral half-width of 15nm indicates high color purity.

10. Development Trends

The trend in LED packaging continues toward smaller footprints and higher efficiency. The 0402 package (1.0x0.5mm) represents the ultra-miniature direction, enabling denser PCB layouts and integration into portable devices. Future improvements may include lower thermal resistance, higher luminous efficacy, and extended operating temperature ranges. Environmental compliance (RoHS, halogen-free) becomes increasingly important in global markets.