LTPL-C036UVG385 UV LED Datasheet - 3.7V Typ - 4.4W Max - 380-390nm Peak Wavelength - English Technical Document

1. Product Overview

The product is a high-performance, energy-efficient ultraviolet (UV) light source designed primarily for UV curing processes and other common UV applications. It represents an advancement in solid-state lighting by merging the long operational lifespan and high reliability inherent to Light Emitting Diodes (LEDs) with intensity levels competitive with traditional UV light sources. This technology offers significant design flexibility and creates new opportunities for solid-state UV solutions to replace conventional UV technologies like mercury-vapor lamps.

1.1 Core Advantages and Target Market

The key features of this UV LED series highlight its advantages for industrial and manufacturing integration. It is I.C. (Integrated Circuit) compatible, facilitating easier electronic control and integration into automated systems. The product is RoHS compliant and lead-free, meeting stringent international environmental and safety standards. A primary benefit is the reduction in total operating costs, achieved through higher electrical efficiency and lower power consumption compared to conventional sources. Furthermore, the extended lifetime and robustness of LED technology significantly reduce maintenance costs and downtime associated with lamp replacement.

2. Technical Parameters: In-Depth Objective Interpretation

2.1 Absolute Maximum Ratings

These ratings define the limits beyond which permanent damage to the device may occur. The absolute maximum DC forward current (If) is 1000 mA. The maximum power consumption (Po) is 4.4 Watts. The device is rated for an operating temperature range (Topr) from -40°C to +85°C and a storage temperature range (Tstg) from -55°C to +100°C. The maximum allowable junction temperature (Tj) is 110°C. It is critically important to avoid operating the LED under reverse bias conditions for extended periods, as this can lead to component failure.

2.2 Electro-Optical Characteristics

These parameters are specified at a standard test condition of 25°C ambient temperature and a forward current (If) of 700mA, which appears to be the typical operating point. The forward voltage (Vf) ranges from a minimum of 2.8V to a maximum of 4.4V, with a typical value of 3.7V. The radiant flux (Φe), which is the total optical power output in the UV spectrum, ranges from 1050 mW (min) to 1545 mW (max), with a typical value of 1230 mW. The peak wavelength (λp) is specified between 380 nm and 390 nm, categorizing it in the UVA spectrum. The viewing angle (2θ1/2) is typically 55 degrees. The thermal resistance from the junction to the solder point (Rthjs) is typically 5.0 °C/W, which is a key parameter for thermal management design.

3. Bin Code System Explanation

The product is classified into bins based on key performance parameters to ensure consistency in application. This allows designers to select LEDs with tightly grouped characteristics.

3.1 Forward Voltage (Vf) Binning

LEDs are sorted into four voltage bins (V0 to V3) at 700mA. The bins are: V0 (2.8V - 3.2V), V1 (3.2V - 3.6V), V2 (3.6V - 4.0V), and V3 (4.0V - 4.4V). The tolerance for this classification is +/- 0.1V.

3.2 Radiant Flux (mW) Binning

Optical output power is binned into five categories (PR to UV) at 700mA. The bins are: PR (1050-1135 mW), RS (1135-1225 mW), ST (1225-1325 mW), TU (1325-1430 mW), and UV (1430-1545 mW). The tolerance is +/- 10%.

3.3 Peak Wavelength (Wp) Binning

The UV spectrum is divided into two wavelength bins: P3R (380-385 nm) and P3S (385-390 nm), with a tolerance of +/- 3nm. The bin classification code is marked on each product packaging bag for traceability.

4. Performance Curve Analysis

4.1 Relative Radiant Flux vs. Forward Current

This curve shows the relationship between the LED's optical output and the drive current. Typically, radiant flux increases with current but may exhibit sub-linear growth at higher currents due to increased thermal effects and efficiency droop. Designers use this to determine the optimal drive current for balancing output and longevity.

4.2 Relative Spectral Distribution

This graph depicts the intensity of light emitted across different wavelengths, centered around the peak wavelength (380-390nm). It shows the spectral bandwidth, which is important for applications where specific photo-initiators are activated by certain wavelengths.

4.3 Radiation Pattern / Viewing Angle

The radiation characteristic plot illustrates the spatial distribution of light intensity. The typical 55-degree viewing angle (full width at half maximum) indicates a moderately wide beam, which is suitable for evenly illuminating an area in curing applications.

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

This fundamental electrical characteristic shows the exponential relationship between voltage and current in a diode. It is crucial for designing the appropriate driver circuitry, as a small change in voltage can cause a large change in current.

4.5 Relative Radiant Flux vs. Junction Temperature

This curve demonstrates the thermal dependence of optical output. UV LED output typically decreases as junction temperature rises. Effective heat sinking is essential to maintain high and stable output power, making this a critical design consideration.

5. Mechanical and Package Information

5.1 Outline Dimensions

The datasheet provides detailed mechanical drawings with all dimensions in millimeters. General dimension tolerances are ±0.2mm, while tolerances for the lens height and ceramic substrate length/width are tighter at ±0.1mm. A critical note specifies that the thermal pad on the bottom of the device is electrically neutral (isolated) from the anode and cathode electrical pads.

5.2 Recommended PCB Attachment Pad Layout

A detailed land pattern diagram is provided for printed circuit board (PCB) design. This includes the size and spacing for the anode, cathode, and thermal pad connections. Adhering to this layout ensures proper soldering, electrical connection, and most importantly, optimal thermal transfer from the LED junction to the PCB and heat sink.

6. Soldering and Assembly Guidelines

6.1 Reflow Soldering Profile

A detailed temperature vs. time graph defines the recommended reflow soldering process. Key parameters include preheat, soak, reflow peak temperature, and cooling rates. The notes emphasize that all temperatures refer to the top side of the package body. A rapid cooling process is not recommended. The lowest possible soldering temperature that achieves a reliable joint is always desirable to minimize thermal stress on the LED.

6.2 Hand Soldering Instructions

If hand soldering is necessary, the maximum recommended condition is 300°C for a maximum of 2 seconds, and this should be performed only once. Reflow soldering should not be performed more than three times maximum.

6.3 Cleaning Instructions

If cleaning is required after soldering, only alcohol-based solvents like isopropyl alcohol should be used. The use of unspecified chemical liquids is prohibited as they may damage the LED package material.

7. Packaging and Handling Information

7.1 Tape and Reel Specifications

The LEDs are supplied on embossed carrier tape and reels for automated pick-and-place assembly. Detailed dimensions for both the tape pockets and the standard 7-inch reels are provided. The tape is sealed with a top cover. A maximum of 500 pieces can be loaded per 7-inch reel. Specifications follow the EIA-481-1-B standard.

8. Application Suggestions and Design Considerations

8.1 Typical Application Scenarios

The primary application is UV curing, used in industries such as printing, coatings, adhesives, and dentistry. Other common UV applications include fluorescence excitation, counterfeit detection, and medical equipment sterilization (within its wavelength range).

8.2 Drive Method and Circuit Design

An LED is a current-operated device. To ensure intensity uniformity when multiple LEDs are connected in parallel within an application, it is strongly recommended to incorporate a current-limiting resistor in series with each individual LED. This compensates for minor variations in the forward voltage (Vf) between different units, preventing current hogging and ensuring even light output and longevity across the array.

8.3 Thermal Management

Given the typical thermal resistance of 5.0 °C/W and the sensitivity of output to junction temperature (as shown in the performance curves), effective heat sinking is non-negotiable for reliable, high-power operation. The PCB should be designed with adequate thermal vias and possibly connected to an external heatsink. The maximum junction temperature of 110°C must not be exceeded.

9. Reliability and Quality Assurance

9.1 Reliability Test Plan

The datasheet outlines a comprehensive reliability test regimen performed on the product. Tests include Low Temperature Operating Life (LTOL at -10°C), Room Temperature Operating Life (RTOL), High Temperature Operating Life (HTOL at 85°C), Wet High Temperature Operating Life (WHTOL at 60°C/90% RH), Thermal Shock (TMSK), and High Temperature Storage. All tests listed showed 0 failures out of 10 samples for the specified durations (500 or 1000 hours).

9.2 Failure Criteria

The criteria for judging device failure after reliability testing are clearly defined. A shift in forward voltage (Vf) beyond ±10% of its initial value at the typical operating current constitutes a failure. Similarly, a shift in radiant flux (Φe) beyond ±15% of its initial value is considered a failure.

10. Frequently Asked Questions (Based on Technical Parameters)

10.1 What is the recommended operating current?

While the absolute maximum current is 1000 mA, all electro-optical characteristics and bin codes are specified at 700 mA, indicating this is the intended typical operating point for optimal performance and lifetime.

10.2 How do I interpret the bin codes for my design?

Select bins based on your system's requirements. For current-driven circuits, the Vf bin is less critical if using individual current-limiting resistors. The radiant flux (mW) bin directly impacts curing speed or light intensity. The wavelength (Wp) bin must match the activation spectrum of your photo-initiator or application.

10.3 Can I drive multiple LEDs in parallel without resistors?

It is not recommended. Due to natural variations in Vf, LEDs connected directly in parallel will not share current equally. The LED with the lowest Vf will draw more current, potentially overheat and fail, causing a chain reaction. Always use a series resistor for each parallel branch or, better yet, use a constant-current driver designed for multiple channels.

11. Technical Introduction and Operating Principle

This device is a semiconductor-based Ultraviolet Light Emitting Diode. It operates on the principle of electroluminescence in a specially engineered semiconductor material (typically based on aluminum gallium nitride - AlGaN). When a forward voltage is applied across the p-n junction, electrons and holes recombine, releasing energy in the form of photons. The specific bandgap energy of the AlGaN material system determines that the emitted photons are in the ultraviolet range (380-390 nm UVA). The package is designed to extract this light efficiently while providing a robust thermal path to manage the heat generated at the semiconductor junction.