UVC3535CZ0115 LED Datasheet - 3.5x3.5x1.0mm Ceramic Package - 5.0-8.0V Forward Voltage - 0.13W Power - 270-285nm Wavelength - English Technical Document

1. Product Overview

The UVC3535CZ0115 series represents a high-reliability, ceramic-based LED solution engineered specifically for ultraviolet C (UVC) applications. This product is designed to deliver consistent performance in demanding environments where sterilization efficacy is paramount. Its core construction leverages a ceramic substrate, which provides superior thermal management compared to traditional plastic packages, leading to enhanced longevity and stable optical output. The series is positioned for applications requiring a compact yet powerful UVC source, combining a small 3.5mm x 3.5mm footprint with robust electrical and optical characteristics.

1.1 Core Features and Advantages

The defining features of this LED series contribute directly to its suitability for professional-grade UV systems. The high-power UVC output is the primary attribute, enabling effective germicidal action. The ceramic package material is a critical advantage, offering excellent heat dissipation that helps maintain junction temperature within safe limits, thereby preventing premature lumen depreciation. Integrated ESD protection up to 2KV (HBM) safeguards the device against electrostatic discharge events common during handling and assembly. A wide 150° viewing angle ensures broad and uniform irradiation coverage. Furthermore, compliance with RoHS, REACH, and halogen-free standards makes this product suitable for global markets with stringent environmental regulations.

1.2 Target Applications

The primary application for the UVC3535CZ0115 series is UV sterilization and disinfection. This includes, but is not limited to, water purification systems, air sanitization devices, surface disinfection equipment for medical and consumer use, and sterilization chambers for small tools or personal items. The 270-285nm wavelength range is particularly effective at inactivating microorganisms by damaging their DNA and RNA.

2. Technical Specifications and Objective Interpretation

This section provides a detailed, objective analysis of the key technical parameters specified in the datasheet, explaining their significance for design engineers.

2.1 Absolute Maximum Ratings

The Absolute Maximum Ratings define the stress limits beyond which permanent damage to the device may occur. These are not conditions for normal operation.

• Max. DC Forward Current (I_F): 100 mA. This is the absolute maximum current the LED can withstand momentarily. Continuous operation should be significantly below this value, typically at the recommended 20mA.
• Max. ESD Resistance (V_B): 2000 V (Human Body Model). This indicates a good level of built-in protection against electrostatic discharge, which is crucial for component handling during manufacturing.
• Max. Junction Temperature (T_J): 100 °C. The temperature of the semiconductor chip itself must not exceed this limit. Exceeding T_J max will drastically reduce lifetime and can cause immediate failure.
• Thermal Resistance (R_th): 20 °C/W. This parameter quantifies how effectively heat travels from the chip (junction) to the solder pad or case. A lower value is better. With 20°C/W, for every watt of power dissipated, the junction temperature will rise 20°C above the pad temperature.
• Operating & Storage Temperature: -40°C to +85°C (Operating), -40°C to +100°C (Storage). These ranges ensure the device can function and be stored in a wide variety of environmental conditions.

2.2 Photometric and Electrical Characteristics

The order code table provides the key performance metrics under typical test conditions.

• Radiant Flux: Minimum 1mW, Typical 2mW, Maximum 2.5mW. This is the total optical power output in the UVC spectrum, measured in milliwatts. It is the critical parameter for gauging sterilization effectiveness, not visual brightness.
• Peak Wavelength: 270-285 nm. This is the wavelength at which the LED emits the most optical power. The germicidal effectiveness peaks around 265nm, so this range is highly effective.
• Forward Voltage (V_F): 5.0-8.0V at I_F=20mA. This is relatively high for an LED, which is characteristic of UVC semiconductor technology. Designers must ensure the driver circuit can provide this voltage range.
• Forward Current (I_F): 20mA. This is the recommended drive current for obtaining the specified radiant flux and lifetime.

3. Binning System Explanation

To ensure consistency in mass production, LEDs are sorted into performance bins. The UVC3535CZ0115 uses three independent binning criteria.

3.1 Radiant Flux Binning

LEDs are sorted based on their minimum radiant flux output into bins Q0A (1-1.5mW), Q0B (1.5-2mW), and Q0C (2-2.5mW). This allows designers to select a bin that meets their minimum required optical power, potentially optimizing cost.

3.2 Peak Wavelength Binning

The wavelength is binned into three ranges: U27A (270-275nm), U27B (275-280nm), and U28 (280-285nm). For applications sensitive to a specific wavelength for maximum germicidal efficiency, specifying the appropriate bin is important.

3.3 Forward Voltage Binning

Voltage is binned in 0.5V steps from 5.0V to 8.0V (e.g., 5055 for 5.0-5.5V, 7580 for 7.5-8.0V). This is crucial for designing constant-current drivers, as knowing the V_F range helps specify the necessary compliance voltage of the driver, impacting efficiency and component selection.

4. Performance Curve Analysis

The typical characteristic curves provide insight into how the LED behaves under varying conditions.

4.1 Spectrum and Optical Power

The spectrum curve shows a peak in the 270-285nm range with a typical full width at half maximum (FWHM) of approximately 10-15nm, which is standard for UVC LEDs. The relative radiant flux vs. forward current curve is sub-linear; output increases with current but may not be perfectly proportional, and driving above the recommended current leads to diminishing returns and excessive heat.

4.2 Electrical and Thermal Behavior

The forward current vs. forward voltage (I-V) curve shows the exponential relationship typical of diodes. The forward voltage increases with current. The peak wavelength shows minimal shift with increasing current, indicating good spectral stability. The derating curve is critical: it shows the maximum allowable forward current must be reduced as the ambient temperature increases to prevent the junction temperature from exceeding 100°C. For example, at 85°C ambient, the maximum current is significantly lower than at 25°C.

4.3 Thermal Performance

The relative radiant flux vs. ambient temperature curve demonstrates the negative impact of heat on output. As temperature rises, the radiant flux decreases. This thermal quenching effect underscores the importance of effective PCB thermal design and heat sinking to maintain optimal performance.

5. Mechanical and Package Information

5.1 Mechanical Dimensions

The LED has a compact footprint of 3.5mm x 3.5mm with a height of 1.0mm (tolerance ±0.2mm). The technical drawing specifies the exact pad layout and dimensions. Pad 1 is the anode (+), Pad 2 is the cathode (-), and Pad 3 is a dedicated thermal pad. The thermal pad is essential for transferring heat from the ceramic body to the PCB. The recommended land pattern on the PCB should closely match this pad configuration to ensure proper soldering and thermal conduction.

5.2 Radiation Pattern

The polar diagram shows a typical lambertian-like emission pattern with a 150° viewing angle (2θ_1/2). The intensity is highest at 0° (perpendicular to the emitting surface) and decreases towards the edges. This wide angle is beneficial for applications requiring area coverage rather than a focused beam.

6. Soldering and Assembly Guidelines

6.1 Reflow Soldering Process

The UVC3535CZ0115 is designed for standard Surface Mount Technology (SMT) processes. The datasheet recommends that reflow soldering should not be performed more than twice to avoid excessive thermal stress on the ceramic package and internal bonds. Standard lead-free reflow profiles with a peak temperature typically below 260°C are applicable, but the specific profile should be verified. Stress on the LED during heating (e.g., from board flexure) must be avoided. After soldering, bending the PCB should be minimized to prevent mechanical stress on the solder joints.

6.2 Storage and Handling

The components are packaged in moisture-resistant barrier bags with desiccant to prevent moisture absorption, which can cause \"popcorning\" during reflow. Once the sealed bag is opened, the components should be used within a specified time frame (typically 168 hours at factory conditions) or baked according to standard IPC/JEDEC guidelines before reflow.

7. Packaging and Ordering Information

7.1 Tape and Reel Packaging

The LEDs are supplied on embossed carrier tape wound onto 7-inch or 13-inch reels. The standard packing quantity is 1000 pieces per reel. The tape dimensions (pocket size, pitch) are specified to be compatible with standard SMT pick-and-place equipment.

7.2 Product Nomenclature (Order Code)

The full order code, e.g., UVC3535CZ0115-HUC7085001X80020-1T, is a structured string that encodes all key specifications:
UVC: Product type.
3535: Package size.
C: Ceramic material.
Z: Contains Zener diode for ESD protection.
01: 1 LED chip.
15: 150° viewing angle.
H: Horizontal chip structure.
UC: UVC color.
7085: Wavelength bin code (270-285nm).
001: Radiant flux bin code (1mW min).
X80: Forward voltage bin code (5.0-8.0V).
020: Forward current (20mA).
1: Packing quantity code (1K pcs).
T: Tape packaging.

8. Application Suggestions and Design Considerations

8.1 Driver Circuit Design

A constant current driver is mandatory for driving this LED. Given the high forward voltage (5-8V) and low current (20mA), the driver must be carefully selected. Linear constant current regulators or switching LED drivers can be used, ensuring the output compliance voltage exceeds the maximum V_F of the selected bin. Thermal management on the PCB is non-negotiable. Use a PCB with sufficient copper thickness and area, connect the thermal pad to a large ground plane using multiple thermal vias, and consider the overall system airflow or heatsinking.

8.2 Safety and Lifetime Considerations

UVC radiation is harmful to eyes and skin. The end-product design must incorporate safety features such as interlock switches, shielding, and warning labels to prevent user exposure. The lifetime of UVC LEDs is typically defined as the time until the radiant flux degrades to a certain percentage (e.g., 70% or 50%) of its initial value. Driving at or below the recommended current and maintaining a low junction temperature through good thermal design are the primary factors in maximizing operational lifetime.

9. Technical Comparison and Differentiation

The UVC3535CZ0115 differentiates itself through its ceramic package, which offers superior thermal performance and reliability compared to plastic SMD packages commonly used for visible LEDs. The integrated Zener diode for ESD protection adds robustness. The 150° viewing angle is wider than some competitive UVC LEDs, which may have more focused beams. The detailed three-dimensional binning (flux, wavelength, voltage) provides designers with precise control over the performance parameters of their final product.

10. Frequently Asked Questions (FAQ)

Q: What is the typical lifetime of this LED?
A: Lifetime is highly dependent on drive current and operating temperature. When operated at the recommended 20mA and with the junction temperature kept low (e.g., below 85°C), lifetimes of 10,000 hours or more to L70 (70% of initial flux) can be expected. Refer to the derating curve and thermal management guidelines.

Q: Can I drive this LED with a constant voltage source?
A: No. LEDs are current-driven devices. A constant voltage source will not regulate the current, leading to thermal runaway and rapid failure. Always use a proper constant current driver.

Q: How do I select the right bin for my application?
A: Choose the Radiant Flux bin (Q0A/B/C) based on your minimum required optical power. Select the Wavelength bin (U27A/B, U28) if your application is optimized for a specific sub-range. The Voltage bin (5055...7580) is important for driver design; you can design for the worst-case (highest) voltage in your selected bin.

Q: Is a lens required?
A> For most sterilization applications where area coverage is needed, the built-in 150° pattern is sufficient. For focused beam applications, an external quartz or specialized UVC-transparent lens may be used. Standard acrylic or polycarbonate lenses block UVC light.

11. Practical Design and Usage Case

Case: Designing a Portable Water Sterilizer
A designer is creating a battery-powered UV water bottle. They select the UVC3535CZ0115 for its compact size and power. They choose the Q0C flux bin (2-2.5mW) to ensure sufficient dose for a small water volume. They design a PCB with a large copper pour connected to the thermal pad. A boost converter constant-current driver is selected to provide 20mA from a 3.7V Li-ion battery, with an output voltage capability exceeding 8V. The LED is placed inside a quartz sleeve within the water flow path. Safety interlocks ensure the LED only operates when the bottle is sealed.

12. Principle Introduction

UVC LEDs operate on the principle of electroluminescence in semiconductor materials, specifically aluminum gallium nitride (AlGaN) alloys. When a forward voltage is applied, electrons and holes recombine in the active region of the semiconductor, releasing energy in the form of photons. The wavelength of these photons is determined by the bandgap energy of the semiconductor material. For UVC emission around 270nm, a high aluminum content in the AlGaN layer is required. The ceramic package serves as a robust, thermally conductive, and hermetic enclosure that protects the sensitive semiconductor chip from environmental factors and efficiently removes heat.

13. Development Trends

The UVC LED market is driven by the global demand for chemical-free disinfection. Key trends include increasing wall-plug efficiency (optical power output per electrical power input), which reduces energy consumption and heat generation. There is ongoing development to lower the cost per milliwatt of optical power. Research is also focused on improving device lifetime and reliability. Furthermore, the development of LEDs at even shorter wavelengths (e.g., 222nm Far-UVC) is an active area of research, promising potentially safer disinfection for occupied spaces. System-level integration, such as driver-on-board modules, is also becoming more common to simplify end-product design.