Blue SMD LED 3.2x1.0x1.5mm - Forward Voltage 3.2V - Power 70mW - Color Blue - Technical Specification

1. Product Overview

The RF-BNT112TS-CF is a surface-mount blue LED fabricated using a blue chip and silicone encapsulation. It comes in a compact package measuring 3.2mm x 1.0mm x 1.5mm, making it ideal for space-constrained applications. This LED offers an extremely wide viewing angle of 140 degrees, ensuring broad light distribution. It is designed for all SMT assembly and solder processes and complies with RoHS requirements. Moisture sensitivity is rated at Level 3, requiring proper handling and storage.

2. Technical Parameters & Binning System

2.1 Electrical & Optical Characteristics (Ta=25°C)

Note: Tolerance for VF measurement is ±0.1V, wavelength ±2nm, luminous intensity ±10%.

2.2 Absolute Maximum Ratings (Ta=25°C)

Note: Pulse condition 1/10 duty cycle, 0.1ms pulse width. The maximum current should be decided based on thermal conditions to ensure junction temperature does not exceed the rated maximum.

2.3 Binning System Explanation

The LED is sorted into wavelength and luminous intensity bins after production. Dominant wavelength bins include D10 (465-467.5nm), D20 (467.5-470nm), E10 (470-472.5nm), and E20 (472.5-475nm). Luminous intensity bins range from 90 mcd (1AP) to 260 mcd (1GK). Forward voltage is not binned into categories but measured with a tolerance of ±0.1V. The bin code on the label indicates the specific combination of wavelength and intensity for traceability.

3. Performance Curve Analysis

3.1 Forward Voltage vs. Forward Current

Fig 1-6 shows the typical forward voltage vs. forward current characteristic. At 20mA, the forward voltage is typically around 3.0-3.2V (within the 2.8-3.5V range). The curve demonstrates the expected exponential increase in current with voltage.

3.2 Forward Current vs. Relative Intensity

As shown in Fig 1-7, relative intensity increases nearly linearly with forward current up to 25mA, with slight saturation at higher currents. This linear relationship allows predictable brightness control by adjusting current.

3.3 Temperature Dependence

Fig 1-8 illustrates that relative intensity decreases with increasing ambient temperature. At 85°C, intensity drops to approximately 80% of the value at 25°C. Fig 1-9 provides derating guidelines: the maximum forward current must be reduced as pin temperature increases to avoid exceeding the junction temperature limit.

3.4 Wavelength vs. Forward Current

Fig 1-10 shows that the dominant wavelength shifts slightly (by about 1-2nm) as forward current increases from 0 to 30mA. This shift is typical for InGaN blue LEDs and should be considered in color-critical applications.

3.5 Spectral Distribution

The relative intensity vs. wavelength curve (Fig 1-11) shows a narrow spectral emission centered around 465-475nm with a half bandwidth of approximately 30nm. This blue emission spectrum is ideal for applications requiring pure blue light.

3.6 Radiation Pattern

Fig 1-12 presents the radiation characteristics. The LED has a wide viewing angle of 140°, with intensity dropping to 50% at approximately ±70° from the optical axis. This broad distribution is achieved by the lens design and is suitable for indicator and backlight applications.

4. Mechanical Dimensions & Soldering Pattern

4.1 Package Dimensions

The LED package measures 3.2mm (length) x 1.0mm (width) x 1.5mm (height). The top view shows a clear lens area; the side view indicates a thickness of 1.5mm including the lens. The bottom view reveals two metal pads (anode and cathode) with dimensions as shown in the drawing. Polarity marking is indicated on the bottom view: pad 1 is cathode and pad 2 is anode (or vice versa per marking). All dimensions have a tolerance of ±0.2mm unless otherwise noted.

4.2 Recommended Soldering Pattern

Fig 1-5 provides the recommended PCB land pattern: each pad is 0.70mm wide and 0.90mm long, with a spacing of 2.20mm between pad centers. This pattern ensures proper solder joint formation and heat dissipation. It is critical to mount the LED on a flat PCB surface and avoid warping.

4.3 Polarity Identification

The cathode is identified by a smaller pad or a corner mark on the bottom view. Correct polarity must be observed during assembly to prevent reverse voltage damage.

5. Soldering & Assembly Guidelines

5.1 Reflow Soldering Profile

The recommended reflow soldering profile (Fig 3-1) specifies: ramp-up rate ≤ 3°C/s (from Tsmin to Tp), preheating from 150°C to 200°C for 60-120 seconds, time above 217°C (TL) for 60s max, peak temperature (Tp) 260°C for 10s max (with time within 5°C of Tp ≤ 30s), and cooling rate ≤ 6°C/s. Total time from 25°C to peak should be ≤ 8 minutes.

5.2 Soldering Iron & Repair

If hand soldering is necessary, use a soldering iron with temperature below 300°C and duration less than 3 seconds. Only one hand soldering operation is allowed. For repair, a double-head soldering iron is recommended; however, it should be confirmed that the repair does not damage LED characteristics.

5.3 Cautions

• The LED uses silicone encapsulation which is soft; avoid applying mechanical pressure on the lens surface. Use appropriate pickup nozzles with controlled force.
• Do not mount on warped PCBs; avoid bending the PCB after soldering.
• Avoid rapid cooling after soldering; allow natural cooling to prevent thermal shock.
• Do not perform reflow soldering more than twice. If the interval between two soldering operations exceeds 24 hours, bake the LEDs before use (60±5°C for ≥24 hours).

6. Packaging Information

6.1 Packaging Specifications

Standard packaging: 3000 pieces per reel. Carrier tape dimensions and reel dimensions are provided in the datasheet (Fig 2-1, 2-2). The reel has a diameter of 178±1mm, width 8.0±0.1mm, hub diameter 60±1mm, and hole diameter 13.0±0.5mm.

6.2 Label Information

Each reel carries a label containing: Part Number, Spec Number, Lot Number, Bin Code (including luminous flux bin, chromaticity bin, forward voltage, wavelength), Quantity, and Date of manufacture.

6.3 Moisture Barrier Packaging

Reels are sealed in a moisture barrier bag with a desiccant and humidity indicator card. The bag is labeled with ESD handling precautions. Storage conditions before opening: ≤30°C, ≤75% RH, shelf life one year from date of packaging. After opening: ≤30°C, ≤60% RH, 24 hours. If storage conditions are exceeded, bake at 60±5°C for ≥24 hours.

7. Reliability Test Conditions

Failure criteria: Forward voltage > 1.1 x U.S.L., Reverse current > 2.0 x U.S.L., Luminous intensity < 0.7 x L.S.L. (U.S.L. = upper spec limit, L.S.L. = lower spec limit).

8. Handling Precautions

8.1 Material Compatibility

The LED package is sensitive to sulfur, bromine, and chlorine compounds. The environment and mating materials must have sulfur content below 100 PPM, bromine below 900 PPM, chlorine below 900 PPM, and total Br+Cl below 1500 PPM. Volatile organic compounds (VOCs) from fixture materials can penetrate silicone and cause discoloration and light output loss. Adhesives that outgas organic vapors should be avoided.

8.2 ESD Protection

LEDs are electrostatic-sensitive devices. Standard ESD precautions (grounded workstations, antistatic wrist straps, conductive containers) must be observed during handling and assembly.

8.3 Cleaning

Recommended cleaning agent: isopropyl alcohol. Other solvents must be tested for compatibility. Ultrasonic cleaning is not recommended as it may cause damage.

8.4 Mechanical Handling

Do not directly touch or apply pressure on the silicone lens. Use forceps or appropriate tools to handle the component by its side surfaces. Avoid stacking or dropping.

8.5 Circuit Design

Each LED must be driven with a current not exceeding the absolute maximum rating. A current-limiting resistor should be used in series. Ensure reverse voltage is never applied. Thermal design is critical: adequate heat sinking is required to keep junction temperature below 95°C.

8.6 Storage & Baking

If moisture barrier bag is punctured or the storage time after opening exceeds 24 hours, bake the LEDs at 60±5°C for ≥24 hours before use. Do not use if the bag shows signs of damage or if the desiccant has changed color.

9. Application Examples

The blue SMD LED is suitable for:

• Optical indicators in consumer electronics (e.g., status lights, notification LEDs)
• Backlighting for switches, symbols, and small displays
• General illumination for decorative or accent lighting
• Blue light source for sensors or photoelectric applications

When designing a circuit, the forward current should be set to 20mA typical. For pulsed operation (e.g., multiplexed displays), the peak current can be increased to 60mA with 1/10 duty cycle. The wide viewing angle (140°) makes the LED suitable for edge-lit designs where light must be emitted over a large area.

10. Design Considerations & Common Questions

10.1 Thermal Management

Given the thermal resistance of 450°C/W, even at 20mA (approx. 64mW power), the junction temperature rise above ambient is about 29°C. At 85°C ambient, junction may exceed 95°C; therefore derating is necessary. Use adequate copper pads and thermal vias to improve heat dissipation.

10.2 Color Uniformity

Because the LED is binned by dominant wavelength, designers should select the appropriate bin for their application. If multiple LEDs are used in the same fixture, order the same bin code to ensure consistent color.

10.3 Driving Circuit

A constant current source is recommended to maintain stable brightness and avoid overcurrent. The forward voltage variation (2.8-3.5V) must be accounted for in the power supply design.

10.4 ESD Sensitivity

The LED has an ESD rating of 1000V (HBM). While this is reasonably robust, proper handling procedures (grounded workstations, antistatic containers) should be followed to prevent damage.

11. Industry Trends & Technology Background

Blue LEDs based on InGaN technology have been foundational for modern solid-state lighting. This package uses a blue chip with silicone encapsulation, which offers high reliability and wide viewing angles. As the industry moves toward miniaturization, this 3.2x1.0mm package provides a compact solution for space-constrained applications. The trend toward higher efficacy and better color control continues, but for many indicator and backlight applications, this standard blue LED remains cost-effective and reliable.