Blue LED Chip Specification 1.0x0.5x0.4mm - 2.6-3.4V - 20mA - 70mW - English Technical Data

1. Product Overview

The RF-BU0402TS-CE-B is a compact surface-mount blue LED fabricated using a high-efficiency blue chip. It is designed for general indication and display applications where a wide viewing angle and small footprint are required. The package dimensions are 1.0mm x 0.5mm x 0.4mm, making it suitable for space-constrained designs. Key features include an extremely wide viewing angle, compatibility with standard SMT assembly and reflow soldering, moisture sensitivity level 3, and RoHS compliance. Typical applications include optical indicators, switch backlighting, symbol displays, and general-purpose status lights.

1.1 General Description

The LED utilizes a blue chip that emits light in the 465–475 nm dominant wavelength range. It is encapsulated in a miniature 1.0mm x 0.5mm x 0.4mm package with a clear epoxy lens. The device is designed for automated surface-mount pick-and-place and can withstand up to two reflow cycles at 260°C peak temperature (per JEDEC standards).

1.2 Features

• Extremely wide viewing angle (typical 140°).
• Suitable for all SMT assembly and solder processes.
• Moisture sensitivity level: Level 3 (per IPC/JEDEC J-STD-020).
• RoHS compliant – free from lead and other restricted substances.
• Available in multiple brightness and voltage bins to suit various design requirements.

1.3 Applications

• Optical indicators in consumer electronics, appliances, and automotive interiors.
• Switch and symbol backlighting (keypads, pushbuttons).
• Display backlighting for small LCD or segment displays.
• General-purpose status indication in industrial and medical equipment.

2. Technical Parameters

All electrical and optical measurements are performed at a test condition of Ts = 25°C unless otherwise specified.

2.1 Electrical / Optical Characteristics (IF = 5 mA)

2.2 Absolute Maximum Ratings (Ts = 25°C)

Note: The maximum current should be decided after measuring the package temperature. The junction temperature must not exceed the rated maximum.

3. Binning System

The LED is categorized into multiple bins for forward voltage, dominant wavelength, and luminous intensity. This allows designers to select devices that meet exact circuit requirements, ensuring consistent brightness and color in multi-LED systems.

3.1 Forward Voltage Bins

Forward voltage is measured at IF = 5 mA. Bins are labeled F1 through J1, covering a range from 2.6V to 3.6V in 0.1V increments. For example, F1 spans 2.6–2.8V, F2 spans 2.7–2.9V, etc. The tolerance for measurement is ±0.1V.

3.2 Dominant Wavelength Bins

Wavelength bins are specified at IF = 5 mA. D10 covers 465.0–467.5 nm, D20 covers 467.5–470.0 nm, E10 covers 470.0–472.5 nm, and E20 covers 472.5–475.0 nm. Measurement tolerance is ±2 nm.

3.3 Luminous Intensity Bins

Intensity bins (IV) are ranked from B00 (12–18 mcd) to F20 (80–100 mcd). This wide range accommodates various brightness requirements in indicators, backlighting, and displays. Bin tolerance is ±10%.

4. Performance Curve Analysis

4.1 Forward Voltage vs. Forward Current

The typical forward voltage increases with forward current. At 5 mA the forward voltage is approximately 2.7–3.1V depending on the bin. The curve is nearly linear from 0 to 25 mA, with a slope of about 0.1–0.2 V per 10 mA.

4.2 Forward Current vs. Relative Intensity

Relative luminous intensity increases approximately linearly with forward current up to 20 mA. At 5 mA the intensity is about 0.3 relative to 20 mA. Operation at higher currents yields higher brightness but also increases junction temperature.

4.3 Ambient Temperature vs. Relative Intensity

As ambient temperature rises from 25°C to 100°C, the relative intensity drops by about 10–15%. This thermal derating must be considered in high-temperature applications.

4.4 Pin Temperature vs. Forward Current

The maximum allowable forward current decreases when the pin (solder point) temperature exceeds about 60°C. At 100°C pin temperature, the maximum continuous forward current is reduced to approximately 15 mA to keep the junction below 95°C.

4.5 Forward Current vs. Dominant Wavelength

Increasing forward current from 0 to 30 mA causes a slight shift in dominant wavelength (approximately +2 nm), which is typical for InGaN LEDs. This effect is small and usually negligible for indicator applications.

4.6 Relative Intensity vs. Wavelength (Spectrum)

The spectral distribution peaks around 470 nm with a full-width at half-maximum (FWHM) of about 15 nm. The emission is narrow, providing a saturated blue color.

4.7 Radiation Pattern

The LED exhibits a Lambertian-like radiation pattern with a wide viewing angle of 140° (half intensity angle 70°). This makes it suitable for wide-area indication.

5. Mechanical and Packaging Information

5.1 Package Dimensions

The LED is housed in a 1.0mm x 0.5mm x 0.4mm package (length x width x height). It has two anode/cathode pads on the bottom side with polarity marked by a notch (see polarity diagram). The recommended soldering pad layout is 0.5mm x 0.6mm per pad with a pad-to-pad spacing of 0.6mm.

5.2 Polarity and Soldering Patterns

The cathode is indicated by a small notch on the top or bottom view. The device is designed for reflow soldering with a typical solder mask opening of 0.25mm clearance. All dimensions are in millimeters with tolerances of ±0.2mm unless otherwise noted.

5.3 Carrier Tape and Reel Dimensions

Parts are packaged in 8mm wide carrier tape with a 2.0mm pitch. Each reel holds 4000 pieces. The reel outer diameter is 178mm ±1mm, hub diameter is 60mm ±0.1mm, and width is 8.0mm +1/-0mm. The tape is sealed with a top cover tape and includes a polarity mark for orientation.

6. Soldering and Assembly Guide

6.1 Reflow Soldering Profile

The recommended reflow profile follows JEDEC standards. Preheat from 150°C to 200°C over 60–120 seconds. The time above 217°C (TL) should be 60–150 seconds. The peak temperature (TP) must not exceed 260°C for more than 10 seconds. Cooling rate should be less than 6°C/s. Maximum two reflow cycles are allowed; if the time between two soldering operations exceeds 24 hours, the LEDs may be damaged.

6.2 Manual Soldering

If hand soldering is necessary, use a soldering iron tip temperature below 300°C for less than 3 seconds. Soldering by hand should be performed only once. Do not apply mechanical force during heating.

6.3 Repair

Repair is not recommended after soldering. If unavoidable, use a dual-head soldering iron and verify that LED characteristics are not degraded.

6.4 Storage and Moisture Management

The LED is moisture sensitive level 3. Before opening the aluminum bag, store at ≤30°C / ≤75% RH for up to one year from the date of sealing. After opening, the shelf life is 168 hours at ≤30°C / ≤60% RH. If the storage time is exceeded or the desiccant has faded, baking is required: 60°C ±5°C for at least 24 hours. Do not bake reels or trays at higher temperatures.

7. Packaging and Ordering Information

Standard packaging is 4000 pieces per reel. Each reel is sealed in a moisture barrier bag with a desiccant and a humidity indicator card. The label includes part number, specification number, lot number, bin code (for flux, chromaticity, forward voltage, and wavelength), quantity, and date code. Reels are packed in cardboard boxes for shipment.

8. Application Notes

8.1 Circuit Design Considerations

Always use current-limiting resistors in series with the LED to prevent forward current from exceeding the absolute maximum rating (20 mA continuous). Even small voltage shifts can cause large current changes. The driver circuit must be designed to allow forward voltage only when the LED is on; reverse voltage can cause migration and damage.

8.2 Thermal Management

Heat generation reduces light output and accelerates aging. Provide adequate heat sinking through solder pads and PCB copper planes. The junction temperature must remain below 95°C. In high ambient temperature environments, derate the forward current accordingly.

8.3 Environmental Restrictions

The operating environment should contain less than 100 ppm of sulfur compounds. Bromine and chlorine content in external materials (encapsulants, adhesives) must each be below 900 ppm, and their total below 1500 ppm. VOCs (volatile organic compounds) from fixture materials can penetrate the silicone encapsulant and cause discoloration; test materials before use.

9. Technical Comparison

Compared to standard 0603 or 0805 packages, the 1.0x0.5x0.4mm footprint saves PCB area while maintaining a wide 140° viewing angle. The low thermal resistance (450 K/W) allows efficient heat transfer. The narrow wavelength binning (±2.5 nm per bin) offers better color consistency than many generic blue LEDs. The high ESD rating (1000V HBM) provides robustness in manufacturing and field use.

10. Frequently Asked Questions (FAQ)

• What is the recommended forward current for typical applications? 5–10 mA is common for indicator use; up to 20 mA for higher brightness, but ensure thermal limits.
• Can I drive the LED with a PWM signal? Yes, but keep peak current below 60 mA and duty cycle below 10% to avoid overheating.
• How should I store unopened reels? At ≤30°C and ≤75% RH, in the original moisture barrier bag.
• What happens if the LED is exposed to ESD beyond 1000V? It may fail catastrophically or show leakage current increase. Use proper ESD protection during handling.
• Why does the forward voltage vary between bins? Manufacturing tolerances cause slight variations in chip properties. Binning ensures consistent electrical behavior in a given bin.

11. Application Case Studies

11.1 Backlighting a Small LCD Panel

Three blue LEDs (E00 bin) were placed in series with a 150Ω resistor and driven at 5V. Each LED received ~10 mA. The combined intensity (180 mcd) adequately backlit a 1.5-inch character display.

11.2 White Light Generation

By coating the blue LED with a yellow phosphor (not included), a white LED can be created. The narrow blue spectrum (465–475 nm) is suitable for phosphor conversion.

11.3 Automotive Interior Indicator

The wide viewing angle and small package allowed placement in a dashboard button. The LED survived thermal cycling tests per AEC-Q101 due to its robust construction.

12. Principle of Operation

The LED is based on an InGaN (indium gallium nitride) semiconductor chip. When forward biased, electrons recombine with holes in the active region, releasing energy as photons. The bandgap of the material determines the emission wavelength (~470 nm for blue). The chip is mounted on a leadframe and encapsulated with translucent epoxy to protect the junction and improve light extraction.

13. Development Trends

The trend for miniature blue LEDs continues toward even smaller footprints (e.g., 0.6x0.3x0.2mm) and higher efficiency (up to 30% WPE). Improved thermal management and ESD protection are being integrated. The use of blue LEDs for phosphor-converted white lighting is expanding in automotive, mobile, and general illumination markets. The industry is also adopting stricter binning standards to ensure color consistency in high-volume applications.