Blue LED SMD Specification - Size 2.8x3.5x0.65mm - Voltage 2.8-3.4V - Power 1.224W - English Technical Document

1. Product Overview

This specification details the technical parameters and handling guidelines for a high-efficiency blue light-emitting diode (LED) designed for surface-mount applications. The device utilizes an InGaN (Indium Gallium Nitride) semiconductor material structure to produce blue light and is encapsulated in a robust PLCC (Plastic Leaded Chip Carrier) package. Its compact form factor and SMT compatibility make it suitable for automated assembly processes in high-volume manufacturing environments.

1.1 Core Advantages and Target Market

The primary advantages of this LED include an extremely wide viewing angle of 120 degrees, which ensures uniform light distribution, and compliance with RoHS (Restriction of Hazardous Substances) directives. The moisture sensitivity level is rated at Level 3, indicating specific handling requirements before soldering. The target markets encompass a broad range of applications including, but not limited to, architectural lighting for hotels and commercial spaces, indoor information displays, landscape accent lighting, and general illumination purposes where reliable blue light sources are required.

2. In-depth Analysis of Technical Parameters

The performance of an LED is defined by its electrical, optical, and thermal characteristics. Understanding these parameters is crucial for proper circuit design and ensuring long-term reliability.

2.1 Electrical and Optical Characteristics

All measurements are standardized at an ambient temperature (Ts) of 25\u00b0C. The forward voltage (VF) ranges from 2.8V to 3.4V when driven at a constant current of 300mA. This parameter is critical for driver design, as it determines the power supply requirements. The luminous flux (\u03a6v) output is between 26 lumens (lm) and 36 lm under the same 300mA condition, defining the device's brightness. The dominant wavelength (\u03bbd) specifies the color point, spanning from 465 nm to 475 nm, which is within the royal blue spectrum. The viewing angle (2\u03b81/2), where intensity drops to half, is typically 120 degrees, providing a very broad emission pattern. The reverse current (IR) is specified at a maximum of 10 \u03bcA at 5V reverse bias, indicating the diode's leakage characteristics.

2.2 Absolute Maximum Ratings and Thermal Management

Exceeding the absolute maximum ratings can cause permanent damage. The maximum permissible forward current (IF) is 360 mA for continuous DC operation. A higher peak forward current (IFP) of 400 mA is allowed but only under pulsed conditions with a 1/10 duty cycle and 0.1ms pulse width to prevent overheating. The maximum reverse voltage (VR) is 5V. The total power dissipation (PD) must not exceed 1224 mW. The junction-to-solder point thermal resistance (RTHJ-S) is 35\u00b0C/W. This value is vital for thermal design; it quantifies how much the junction temperature rises for every watt of power dissipated. The maximum allowable junction temperature (TJ) is 110\u00b0C. Proper heat sinking via the PCB pads is essential to maintain the junction temperature within safe limits, especially when operating at higher currents or in elevated ambient temperatures. The operating temperature range is from -40\u00b0C to +85\u00b0C, and the storage temperature range is from -40\u00b0C to +100\u00b0C.

3. Binning System Explanation

To ensure consistency in mass production, LEDs are sorted into bins based on key parameters measured at a test current of 300mA. This allows designers to select parts that meet specific performance criteria for their application.

3.1 Forward Voltage Binning

The forward voltage is categorized into three bins: G0 (2.8V - 3.0V), H0 (3.0V - 3.2V), and I0 (3.2V - 3.4V). Selecting LEDs from a tighter voltage bin can simplify driver design by reducing the voltage variation across the LED string.

3.2 Luminous Flux Binning

The luminous output is sorted into four bins: QIA (26-28 lm), REA (28-30 lm), RFA (30-33 lm), and RGA (33-36 lm). This binning is essential for applications requiring consistent brightness levels, such as in display backlighting modules.

3.3 Dominant Wavelength Binning

The color (dominant wavelength) is divided into four bins: D10 (465-467.5 nm), D20 (467.5-470 nm), E10 (470-472.5 nm), and E20 (472.5-475 nm). For color-critical applications, specifying a narrow wavelength bin ensures minimal color shift between different units.

4. Performance Curve Analysis

The provided characteristic curves offer valuable insights into the LED's behavior under varying operating conditions.

4.1 Forward Current vs. Forward Voltage (IV Curve)

The curve shows a non-linear relationship typical of diodes. The forward voltage increases with current, but the rate of increase is not linear. At the typical operating point of 300mA, the voltage is around 3.0V to 3.2V. Designers must ensure the current driver can supply the necessary voltage, especially considering the voltage bin spread and temperature effects.

4.2 Forward Current vs. Relative Luminous Intensity

This curve demonstrates that light output is approximately proportional to the forward current in the typical operating range. However, driving the LED beyond its maximum rated current will not yield proportional light increase and will severely shorten its lifespan due to excessive heat generation.

4.3 Temperature Dependence

Two key curves illustrate temperature effects: Relative Luminous Flux vs. Solder Point Temperature (Ts) and Forward Current vs. Ts. As temperature rises, the luminous output generally decreases, a phenomenon known as thermal quenching. Simultaneously, the forward voltage decreases slightly with increasing temperature. These effects must be compensated for in precision lighting systems, often through feedback control mechanisms in the driver circuitry.

5. Mechanical and Packaging Information

5.1 Package Dimensions and Tolerances

The device has a rectangular footprint measuring 2.80 mm in length and 3.50 mm in width, with a profile height of 0.65 mm. All dimension tolerances are \u00b10.2 mm unless otherwise specified. Detailed top, side, and bottom views, along with polarity identification (typically via a cathode mark or a cut corner) and recommended solder pad land patterns, are essential for PCB layout. Adhering to the recommended pad geometry ensures proper solder joint formation, mechanical stability, and optimal thermal conduction away from the LED die.

6. Soldering and Assembly Guidelines

6.1 SMT Reflow Soldering Instructions

This LED is compatible with standard infrared (IR) or convection reflow soldering processes. Due to its Moisture Sensitivity Level (MSL) 3 rating, the components must be baked before soldering if the sealed dry-bag has been opened and the exposure time to ambient humidity exceeds the specified limit (usually 168 hours at \u226430\u00b0C/60% RH). A typical reflow profile should have a preheat zone to slowly raise the temperature, a soaking zone to activate the flux and equalize temperatures, a peak reflow zone where the solder melts (typically with a peak temperature not exceeding 260\u00b0C for a duration recommended by the solder paste manufacturer), and a controlled cooling zone. Exceeding the maximum junction temperature of 110\u00b0C during this process must be avoided.

7. Packaging and Ordering Information

The components are supplied on embossed carrier tapes wound onto reels, suitable for automated pick-and-place machines. The carrier tape dimensions, reel dimensions, and label specifications ensure compatibility with standard SMT equipment. For moisture protection, the reels are packaged in sealed barrier bags with desiccant and humidity indicator cards. Outer packaging typically involves cardboard boxes for shipping. Specific tape width, pocket spacing, and reel diameter details are necessary for feeder setup on assembly lines.

8. Application Recommendations

Beyond the listed applications (hotels, markets, indoor displays, landscape lighting), this LED is well-suited for backlighting small LCD panels, status indicator lights in consumer electronics, decorative lighting strips, and automotive interior lighting (non-critical). Design considerations include: implementing a constant-current driver for stable light output, providing adequate thermal vias and copper area on the PCB for heat dissipation, avoiding electrical overstress from static discharge (ESD protection circuits are advised as the HBM ESD rating is 2000V), and ensuring optical design accounts for the 120-degree viewing angle for desired light distribution.

9. Frequently Asked Questions (Based on Technical Parameters)

9.1 What driver is needed for this LED?

A constant current driver is mandatory. The driver should be capable of providing up to 360 mA DC and must accommodate the forward voltage range of 2.8V to 3.4V per LED, including any series or parallel combinations.

9.2 How does temperature affect performance?

As temperature increases, light output decreases, and forward voltage decreases. For consistent performance, thermal management is crucial. Operating near the maximum current rating in a high ambient temperature may require derating the current.

9.3 What is the significance of the bin codes?

Bin codes like \"RF-BNRI35TS-EK-2T\" and the VF/\u03a6v/\u03bbd bin codes (e.g., H0, RFA, E10) specify the exact performance subset of the LED. Ordering by bin code ensures you receive LEDs with tightly grouped characteristics for your project.

10. Practical Case Study: Indoor Display Module

Consider a design for a fine-pitch indoor LED display panel. Using this blue LED, a designer would select a specific luminous flux bin (e.g., RFA for 30-33 lm) and wavelength bin (e.g., E10 for 470-472.5 nm) to ensure color and brightness uniformity across the screen. The LEDs would be driven at a current below the maximum, perhaps 280mA, to enhance longevity and reduce thermal load. The PCB would incorporate a solid ground plane and thermal relief pads under each LED. The wide viewing angle allows for good visibility even from oblique angles, which is ideal for signage and information displays.

11. Principle of Operation

This is a semiconductor diode based on an InGaN multi-quantum well structure. When a forward voltage exceeding the diode's turn-on threshold is applied, electrons and holes are injected into the active region where they recombine, releasing energy in the form of photons. The specific bandgap energy of the InGaN material determines the wavelength of the emitted light, in this case, blue. The epoxy or silicone lens of the PLCC package shapes the light output and provides environmental protection.

12. Industry Trends and Development

The LED industry continues to focus on increasing luminous efficacy (lumens per watt), improving color rendering index (CRI) for white light applications, and reducing cost per lumen. For monochromatic LEDs like this blue device, trends include pushing for higher power densities in smaller packages, achieving narrower wavelength distributions for purer colors, and enhancing long-term reliability under high-temperature operating conditions. The move towards more efficient and durable packaging materials also remains a key research area.