LED 0402 Yellow 1.0x0.5x0.4mm - Forward Voltage 1.7-2.4V - Power 48mW - Technical Datasheet

1. Product Overview

The RF-YU0402TS-CE-B is a compact yellow SMD LED designed for general-purpose indication and backlighting applications. Housed in a miniature 1.0mm x 0.5mm x 0.4mm package, this LED utilizes a high-efficiency yellow chip to deliver a dominant wavelength range of 585nm to 595nm. With an extremely wide viewing angle of 140 degrees and compatibility with standard SMT assembly processes, it is suitable for space-constrained designs where reliable optical performance is required. The LED features a moisture sensitivity level of 3 and is RoHS compliant.

2. Technical Parameter Interpretation

2.1 Electrical / Optical Characteristics (at Ts=25°C)

The LED is characterized under a test current of 5mA. Key parameters include:

• Forward Voltage (VF): Binned into multiple groups from 1.7V to 2.4V, allowing precise voltage matching for series/parallel designs. Example bins: A2 (1.7-1.8V), B1 (1.8-1.9V), C1 (1.9-2.0V), D1 (2.2-2.3V), etc.
• Dominant Wavelength (λD): Ranges from 585nm to 595nm, with sub-bins such as D10 (585-587.5nm), D20 (587.5-590nm), E10 (590-592.5nm), E20 (592.5-595nm). This ensures consistent color appearance in production.
• Luminous Intensity (IV): Binned into six groups: A00 (8-12 mcd), B00 (12-18 mcd), C00 (18-28 mcd), D00 (28-43 mcd), E00 (43-65 mcd), F00 (65-100 mcd). Designers can select the appropriate brightness bin for their application.
• Viewing Angle (2θ1/2): Typical 140°, providing a wide emission cone suitable for indicator lights.
• Reverse Current (IR): Maximum 10 μA at VR=5V, ensuring low leakage.
• Thermal Resistance (RTHJ-S): 450°C/W (typical), which must be considered in thermal management.

2.2 Absolute Maximum Ratings

• Power Dissipation (Pd): 48 mW
• Forward Current (IF): 20 mA (continuous)
• Peak Forward Current (IFP): 60 mA (1/10 duty cycle, 0.1ms pulse width)
• Electrostatic Discharge (ESD, HBM): 2000 V
• Operating Temperature (Topr): -40°C to +85°C
• Storage Temperature (Tstg): -40°C to +85°C
• Junction Temperature (Tj): 95°C

Care must be taken to ensure that the junction temperature does not exceed the maximum rating, especially under high ambient temperatures or when multiple LEDs are driven close to their limits.

3. Binning System

3.1 Wavelength Binning

The dominant wavelength is divided into four main bins: D10, D20, E10, E20, each spanning 2.5nm intervals from 585nm to 595nm. This narrow binning ensures color consistency within a single reel.

3.2 Luminous Intensity Binning

Six intensity bins (A00 through F00) cover a range from 8 mcd to 100 mcd, with each bin having a ratio of approximately 1.5x. This allows designers to select the appropriate brightness level without overdriving the LED.

3.3 Forward Voltage Binning

Voltage is binned into 12 groups from 1.7V to 2.4V (e.g., A2, B1, B2, C1, C2, D1, D2). Matching voltage bins in parallel strings helps balance current distribution.

4. Performance Curves Analysis

4.1 Forward Voltage vs. Forward Current (Fig 1-6)

The curve shows a typical exponential relationship. At 5mA test current, VF is approximately 2.0V, increasing to about 2.8V at 25mA. Designers should account for this voltage variation when setting current-limiting resistors.

4.2 Forward Current vs. Relative Intensity (Fig 1-7)

Relative intensity increases nearly linearly with forward current up to 7.5mA, with saturation tendencies at higher currents. Operating near the test current (5mA) provides a good balance between brightness and efficiency.

4.3 Temperature Effects (Fig 1-8, Fig 1-9)

As ambient or pin temperature rises, relative intensity decreases (about 10% from 25°C to 75°C). The maximum forward current must be derated at higher temperatures to avoid exceeding the junction temperature limit.

4.4 Forward Current vs. Dominant Wavelength (Fig 1-10)

The dominant wavelength shifts slightly with current (about 1nm over 25mA range), which is typical for InGaN-based yellow LEDs. This shift is negligible for most indicator applications.

4.5 Spectral Distribution (Fig 1-11)

The emission peak is around 590nm with a full width at half maximum (FWHM) of approximately 15nm. The narrow spectrum ensures good color purity for yellow indicators.

4.6 Radiation Pattern (Fig 1-12)

The radiation pattern shows a typical Lambertian distribution with wide angular uniformity. Relative intensity remains above 0.6 at ±40°, confirming the 140° viewing angle.

5. Mechanical and Packaging Information

5.1 Package Dimensions

The LED measures 1.0mm (length) x 0.5mm (width) x 0.4mm (height). The bottom view shows two pads: Pad 1 (cathode) and Pad 2 (anode). Polarity is indicated by a notch on the top view. Soldering patterns recommend 0.5mm x 0.6mm pads with 0.6mm spacing.

5.2 Carrier Tape and Reel

Each reel contains 6,000 pieces. Carrier tape dimensions: 8mm width, 2.00mm feed pitch, with polarity mark. Reel diameter is 178mm (7 inches), hub diameter 60mm, and width 8.0mm.

5.3 Label Information

Labels include part number, spec number, lot number, bin code (for flux, chromaticity, VF, wavelength), quantity, and date code.

6. Soldering and Assembly Guidelines

6.1 Reflow Soldering Profile

Recommended profile: Preheat from 150°C to 200°C for 60-120 seconds, ramp-up rate ≤3°C/s, peak temperature 260°C (max 10 seconds), cooling rate ≤6°C/s. The LED can withstand up to 2 reflow cycles, but more than 2 may cause damage.

6.2 Hand Soldering

If hand soldering is necessary, keep iron temperature below 300°C and duration under 3 seconds. Only one hand soldering operation is allowed.

6.3 Storage and Moisture Control

Store unopened bags at 30°C/75% RH for up to 1 year. After opening, use within 168 hours at 30°C/60% RH. If moisture exposure exceeds limits, bake at 60±5°C for 24 hours before use.

7. Application Recommendations

7.1 Typical Applications

• Optical indicators on consumer electronics, appliances, and automotive panels
• Switch and symbol backlighting
• General-purpose status and alarm lights
• Small-format displays and signage

7.2 Design Considerations

• Always use current-limiting resistors to prevent overcurrent; a slight voltage shift can cause large current changes.
• Ensure adequate thermal management: keep junction temperature below 95°C, especially when operating near maximum current.
• Avoid exposing the LED to environments with high sulfur content (>100PPM) to prevent tarnishing of internal components.
• Minimize VOC outgassing from adhesives and potting materials to avoid discoloration of the silicone encapsulant.
• Protect against electrostatic discharge (ESD) – the LED is rated for 2000V HBM, but ESD precautions during handling and assembly are recommended.

8. Reliability and Testing

The LED has passed reliability tests including temperature cycling (−40°C to 100°C, 100 cycles), thermal shock (−40°C to 100°C, 300 cycles), high-temperature storage (100°C, 1000h), low-temperature storage (−40°C, 1000h), and life test (25°C, 5mA, 1000h). Acceptance criteria require forward voltage within 1.1x upper spec limit, reverse current within 2.0x upper limit, and luminous flux above 0.7x lower spec limit.

9. Principle of Operation

This LED uses a yellow-emitting semiconductor chip, typically based on the InGaN (indium gallium nitride) material system with appropriate phosphor or direct emission to achieve the 585–595nm wavelength. When forward biased, electrons and holes recombine at the p-n junction, releasing photons. The small chip size and efficient design enable high brightness at low current, making it ideal for battery-powered devices.

10. Development Trends

Miniaturization of SMD LEDs continues, with 0402 packages becoming a standard for high-density designs. Future trends include further improvements in luminous efficacy, wider color gamut, and enhanced thermal management. The adoption of lead-free and RoHS-compliant materials is now standard. Additionally, advanced binning techniques allow tighter control of color and brightness, enabling more uniform lighting arrays.