UVC3535CZ0215 LED Datasheet - 3.5x3.5x0.99mm - 5.0-8.0V - 0.7W - 270-285nm - English Technical Documentation

1. Product Overview

The UVC3535CZ0215 series represents a high-reliability, ceramic-based UVC LED solution engineered for demanding ultraviolet applications. This product is designed to deliver consistent performance in environments where durability and optical output stability are critical.

1.1 Core Advantages

The primary advantages of this LED series stem from its material construction and electrical design. The ceramic package offers superior thermal management compared to plastic alternatives, directly contributing to longer operational lifespan and stable radiant flux output. The integrated Zener diode provides electrostatic discharge (ESD) protection rated up to 2,000V (Human Body Model), significantly enhancing the component's robustness against handling and environmental electrical transients. Furthermore, the product is compliant with major environmental and safety directives including RoHS, is lead-free, and adheres to EU REACH and halogen-free standards (Br<900ppm, Cl<900ppm, Br+Cl<1500ppm), making it suitable for global markets with strict regulatory requirements.

1.2 Target Applications

The dominant application for this UVC LED series is UV sterilization and disinfection. The 270-285nm wavelength range is particularly effective at inactivating microorganisms such as bacteria, viruses, and molds by damaging their DNA and RNA. Specific use cases include water purification systems, air disinfection units, surface sterilization devices in healthcare settings, and consumer-grade sanitization products. The 150° wide viewing angle facilitates designs requiring broad-area coverage without complex optical secondary lenses.

2. In-Depth Technical Parameter Analysis

A thorough understanding of the electrical, optical, and thermal parameters is essential for successful integration into an end product.

2.1 Absolute Maximum Ratings

These ratings define the stress limits beyond which permanent damage may occur. The maximum continuous forward current (I_F) is 150mA. The absolute maximum junction temperature (T_J) is 90°C. The device can operate within an ambient temperature range of -40°C to +85°C and be stored from -40°C to +100°C. The thermal resistance from junction to soldering pad (R_th) is specified as 20°C/W, a key figure for heatsink design.

2.2 Photometric and Electrical Characteristics

For the specific order code UVC3535CZ0215-HUC7085008X80100-1T, the minimum radiant flux is 8mW, typical is 10mW, and maximum is 15mW, all measured at the forward current (I_F) of 100mA. The forward voltage (V_F) at this current ranges from 5.0V to 8.0V. The peak wavelength emission is between 270nm and 285nm. Designers must account for this V_F range when selecting a constant current driver.

3. Binning System Explanation

The product is classified into bins to ensure consistency within a production lot. Three key parameters are binned.

3.1 Radiant Flux Binning

Radiant flux is sorted into two bins: Q1 (8-10mW) and Q2 (10-15mW). This allows designers to select LEDs based on the required optical power output for their application, with measurement tolerance of ±10%.

3.2 Peak Wavelength Binning

The peak wavelength is critical for sterilization efficacy. Bins are: U27A (270-275nm), U27B (275-280nm), and U28 (280-285nm), with a measurement tolerance of ±1nm. Applications targeting specific pathogen inactivation spectra can select the appropriate bin.

3.3 Forward Voltage Binning

Forward voltage is binned in 0.5V increments from 5.0V to 8.0V (e.g., 5055 for 5.0-5.5V, 5560 for 5.5-6.0V, etc.), with a measurement tolerance of ±2% at 100mA. This binning aids in designing efficient driver circuits and managing thermal load across multiple LEDs in series or parallel.

4. Performance Curve Analysis

The datasheet provides several characteristic curves essential for predicting real-world performance.

4.1 Spectrum and Relative Flux vs. Current

The spectrum curve shows a typical peak in the 270-285nm UVC range with minimal emission in other bands. The Relative Radiant Flux vs. Forward Current curve is nearly linear up to the rated 100mA, indicating good current-to-light conversion efficiency within the operating range.

4.2 Thermal and Electrical Relationships

The Peak Wavelength vs. Current curve shows minimal shift (<5nm) across the operating current range, indicating stable chromaticity. The Forward Current vs. Forward Voltage (I-V) curve demonstrates the diode's characteristic exponential relationship, crucial for driver design. The Relative Radiant Flux vs. Ambient Temperature curve shows output decreasing as temperature rises, a typical behavior for LEDs that must be compensated for in thermal management.

4.3 Derating Curve

Perhaps the most critical for reliability, the Derating Curve plots the maximum allowable forward current against ambient temperature. As ambient temperature increases, the maximum permissible current must be reduced to prevent the junction temperature from exceeding 90°C. For example, at 85°C ambient, the maximum current is significantly derated from the 150mA absolute maximum.

5. Mechanical and Package Information

5.1 Physical Dimensions

The package dimensions are 3.5mm (L) x 3.5mm (W) x 0.99mm (H), with a tolerance of ±0.2mm unless otherwise specified. This 3535 footprint is a common industry standard, facilitating PCB layout and pick-and-place assembly.

5.2 Pad Configuration and Polarity

The device has three pads: Pad 1 is the Anode (+), Pad 2 is the Cathode (-), and Pad 3 is a dedicated Thermal Pad. The thermal pad is essential for efficient heat transfer from the LED junction to the PCB and must be properly soldered to a corresponding copper pour on the board to achieve the specified thermal performance (R_th 20°C/W). Incorrect polarity connection will prevent the LED from illuminating and may damage the internal Zener protection diode.

6. Soldering and Assembly Guidelines

6.1 Reflow Soldering Process

The UVC3535CZ0215 is suitable for standard Surface-Mount Technology (SMT) processes. The datasheet emphasizes that reflow soldering should not be performed more than twice to avoid excessive thermal stress on the ceramic package and internal die attach materials. During heating, mechanical stress on the LED body must be avoided. After soldering, the PCB should not be bent, as this can crack the ceramic package or break the solder joints.

6.2 Storage Conditions

While not explicitly detailing storage humidity levels, the product is shipped in a moisture-resistant packaging system (see Packaging section), indicating it is sensitive to moisture absorption. It is recommended to follow standard JEDEC moisture sensitivity level (MSL) handling procedures for ceramic packages if the bag has been opened, typically involving baking before reflow if exposed beyond a certain time limit.

7. Packaging and Ordering Information

7.1 Tape and Reel Packaging

The LEDs are supplied on embossed carrier tape wound onto reels. The standard packing quantity is 1,000 pieces per reel. The carrier tape dimensions are provided to ensure compatibility with automated assembly equipment feeders.

7.2 Moisture-Resistant Shipping

The reels are sealed inside an aluminum moisture-proof bag along with desiccant to control humidity during storage and transport. The bag is labeled with relevant product information.

7.3 Product Nomenclature Decoding

The full order code UVC3535CZ0215-HUC7085008X80100-1T is structured as follows:

• UVC3535CZ0215: Base part number indicating UVC, 3.5x3.5mm Ceramic package with Zener, 2 chips, 150° angle.
• H: Chip type (Horizontal).
• UC: Color Rendering Index (UVC-specific code).
• 7085: Wavelength range 270-285nm.
• 008: Minimum Radiant Flux 8mW.
• X80: Forward Voltage range 5.0-8.0V.
• 100: Forward Current 100mA.
• 1: Packaging quantity code (1K pieces).
• T: Tape packaging.

8. Application Design Considerations

8.1 Driver Circuit Design

A constant current driver is mandatory for stable operation and longevity. The driver must be capable of delivering up to 100mA (or the chosen operating point) and withstand the maximum forward voltage of up to 8.0V per LED. When connecting multiple LEDs in series, the driver's compliance voltage must exceed the sum of the maximum V_F of all LEDs plus headroom. Parallel connection is generally not recommended without individual current balancing due to V_F binning variations.

8.2 Thermal Management

Effective heat sinking is non-negotiable. Using the thermal resistance (R_th) of 20°C/W and the power dissipation (P_D = V_F * I_F), the temperature rise from pad to junction can be calculated: ΔT = R_th * P_D. The PCB must have a sufficiently large and well-connected thermal pad (Pad 3) soldered to a copper plane, potentially with thermal vias connecting to inner or bottom layers. The derating curve must be consulted to ensure the junction temperature remains below 90°C at the intended operating current and maximum ambient temperature.

8.3 Optical and Safety Considerations

UVC radiation is harmful to human skin and eyes. The end-product design must incorporate safety features such as interlock switches, shielding, and warning labels to prevent exposure. The 150° viewing angle provides wide coverage but may require reflectors or enclosures to direct light efficiently to the target surface. Materials exposed to UVC must be resistant to degradation from prolonged UV exposure (e.g., certain plastics may yellow or become brittle).

9. Technical Comparison and Differentiation

The UVC3535CZ0215 differentiates itself through its ceramic package and integrated Zener diode. Compared to plastic-packaged UVC LEDs, the ceramic body offers superior thermal conductivity, leading to potentially lower junction temperature at the same drive current, which translates to longer lifetime (L70/B50) and more stable output. The 2KV ESD protection is a significant reliability advantage, reducing failure rates during assembly and handling. The explicit binning for wavelength, flux, and voltage provides designers with predictable performance parameters, enabling tighter system tolerances.

10. Frequently Asked Questions (FAQ)

10.1 What is the typical lifetime of this LED?

While the datasheet does not provide an L70/B50 lifetime graph, the lifetime of UVC LEDs is strongly influenced by operating junction temperature. Maintaining the junction temperature well below the 90°C maximum, ideally below 60-70°C, through effective thermal design is the primary factor in achieving thousands of hours of operational life.

10.2 Can I drive this LED with a constant voltage source?

No. LEDs are current-driven devices. A constant voltage source will not regulate the current, leading to thermal runaway and rapid failure due to the negative temperature coefficient of the LED's forward voltage. Always use a constant current driver or a circuit that actively regulates current.

10.3 How do I interpret the Radiant Flux (mW) specification for my sterilization application?

Radiant flux (in milliwatts) is the total optical power emitted in the UVC band. The required flux depends on the target pathogen's UV dose (measured in mJ/cm²), the distance to the target, exposure time, and optical system efficiency. You must calculate the required irradiance (μW/cm²) at the target and work backwards through your system's optical efficiency to determine the necessary LED flux.

11. Design and Usage Case Study

Scenario: Designing a handheld surface sanitizer wand. The design requires a compact form factor, battery operation, and effective disinfection in 5-10 seconds per pass. The UVC3535CZ0215 is selected for its small 3535 footprint and 150° angle, allowing a simple array of 3-5 LEDs to cover the wand's head area. A lithium-ion battery with a boost constant-current driver is designed to provide 80mA per LED (slightly derated for thermal margin in a handheld device). The PCB uses a 2-ounce copper layer with a large thermal pad under the LED array connected to the device's aluminum housing via thermal paste. The housing acts as the heatsink. An accelerometer-based safety switch ensures the LEDs only activate when the wand is facing downwards towards a surface, preventing accidental exposure. The wavelength bin U27B (275-280nm) is chosen for its balance of efficacy against common pathogens and material compatibility.

12. Operational Principle

UVC LEDs operate on the principle of electroluminescence in semiconductor materials, specifically aluminum gallium nitride (AlGaN) based structures. When a forward voltage is applied, electrons and holes recombine in the active region of the semiconductor chip, releasing energy in the form of photons. The specific wavelength of 270-285nm is achieved by carefully controlling the bandgap energy of the AlGaN layers through their aluminum composition. This short-wavelength, high-energy UV-C light is absorbed by the DNA and RNA of microorganisms, causing thymine dimers which inhibit replication and lead to inactivation or cell death.

13. Technology Trends

The UVC LED market is focused on increasing wall-plug efficiency (optical output power per electrical input power), which historically has been low compared to visible LEDs. Improvements in epitaxial growth, chip design, and package extraction efficiency are driving efficacy gains. Another trend is the development of LEDs at even shorter wavelengths (e.g., 220-230nm, known as Far-UVC), which may offer enhanced safety for human exposure while retaining germicidal properties. Additionally, higher power single-die emitters and multi-chip packages are emerging to increase irradiance and reduce the number of components needed in a system. The ongoing push for cost reduction is making UVC LED solutions increasingly competitive with traditional mercury-vapor lamps across more application segments.