LTPL-C16FUVD405 UV LED Datasheet - 3.2x1.6x1.6mm - 3.3V - 1.75W - 405nm - English Technical Document

1. Product Overview

The LTPL-C16F series represents a significant advancement in solid-state lighting technology, specifically engineered for ultraviolet (UV) applications. This product is a revolutionary, energy-efficient, and ultra-compact light source that successfully merges the exceptional lifetime and reliability inherent to Light Emitting Diodes (LEDs) with the high brightness levels traditionally associated with conventional lighting systems. This combination provides design engineers with unparalleled freedom, enabling the creation of new, compact form factors while delivering the optical power necessary to effectively displace older, less efficient lighting technologies in demanding environments.

1.1 Key Features

• Fully compatible with standard automatic placement and pick-and-place equipment for high-volume manufacturing.
• Designed to withstand both infrared (IR) and vapor phase reflow soldering processes, ensuring robust assembly.
• Packaged in a standardized EIA (Electronic Industries Alliance) form factor for ease of integration into existing designs.
• Input characteristics are compatible with standard integrated circuit (IC) drive levels.
• Manufactured as a green product, compliant with RoHS directives and free from lead (Pb) and other restricted substances.

1.2 Target Applications

This UV LED is specifically designed for applications requiring a focused source of 405nm ultraviolet light. Primary use cases include:

• UV Curing: Rapid polymerization and hardening of adhesives, coatings, and inks.
• UV Marking & Coding: Permanent marking on various substrates.
• UV Gluing: Fast-setting adhesive processes.
• Printing Ink Drying: Accelerated drying and curing of specialized UV-reactive inks.

2. Mechanical and Package Information

The device is housed in an ultra-compact surface-mount package. Critical outline dimensions are as follows (all values in millimeters, with a standard tolerance of ±0.1mm unless otherwise specified): The package body measures approximately 3.2mm in length, 1.6mm in width, and has a height of 1.6mm. Detailed mechanical drawings, including pad layout recommendations for infrared and vapor phase reflow soldering, are provided in the datasheet to ensure proper PCB footprint design for thermal and mechanical reliability.

3. Absolute Maximum Ratings

Stresses beyond these limits may cause permanent damage to the device. All ratings are specified at an ambient temperature (Ta) of 25°C.

• Power Dissipation (Po): 1.75 W
• DC Forward Current (If): 500 mA
• Operating Temperature Range (Topr): -40°C to +85°C
• Storage Temperature Range (Tstg): -40°C to +100°C
• Maximum Junction Temperature (Tj): 115°C

4. Electro-Optical Characteristics

Key performance parameters are measured at Ta=25°C under a test condition of If = 350mA, unless stated otherwise.

• Radiant Flux (Φe): 440 mW (Min), 500 mW (Typ), 590 mW (Max). Measurement tolerance is ±10%.
• Viewing Angle (2θ1/2): 135° (Typical).
• Peak Wavelength (λp): 395 nm (Min), 405 nm (Typ), 415 nm (Max). This defines the central emission in the near-UV spectrum. Tolerance is ±3nm.
• Forward Voltage (Vf): 3.1 V (Min), 3.3 V (Typ), 3.5 V (Max) at 350mA. Measurement tolerance is ±0.1V.
• Reverse Voltage (Vr): 1.2 V (Max) at a reverse current (Ir) of 10µA. Important Note: This parameter is tested for Zener function characterization only. The LED is not designed for operation under reverse bias. Extended reverse current exposure can lead to device failure.

ESD Caution: This component is sensitive to electrostatic discharge (ESD). Proper handling procedures, including the use of grounded wrist straps, anti-static mats, and equipment, are mandatory to prevent latent or catastrophic damage.

5. Bin Code and Classification System

To ensure consistent performance in production, devices are classified into bins based on key parameters. The bin code is marked on the packaging.

5.1 Forward Voltage (Vf) Binning

• Bin V3: Vf = 3.1V to 3.3V @ 350mA
• Bin V4: Vf = 3.3V to 3.5V @ 350mA

5.2 Radiant Flux (Φe) Binning

• Bin R1: Φe = 440 mW to 470 mW
• Bin R2: Φe = 470 mW to 500 mW
• Bin R3: Φe = 500 mW to 530 mW
• Bin R4: Φe = 530 mW to 560 mW
• Bin R5: Φe = 560 mW to 590 mW

5.3 Peak Wavelength (λp) Binning

• Bin P3U: λp = 395 nm to 400 nm
• Bin P4A: λp = 400 nm to 405 nm
• Bin P4B: λp = 405 nm to 410 nm
• Bin P4C: λp = 410 nm to 415 nm

6. Performance Curve Analysis

The datasheet provides several characteristic curves crucial for design optimization.

6.1 Relative Emission Spectrum

The spectral distribution curve shows a dominant peak centered at 405nm (typical), with a relatively narrow spectral bandwidth characteristic of LED technology. This monochromaticity is advantageous for applications requiring specific photo-initiation.

6.2 Relative Radiant Flux vs. Forward Current

This curve demonstrates the relationship between optical output and drive current. The radiant flux increases super-linearly with current at lower levels and tends to saturate at higher currents due to thermal and efficiency droop effects. Operating at or below the typical 350mA is recommended for optimal efficiency and lifetime.

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

The I-V characteristic is essential for driver design. It shows the exponential relationship typical of a diode. The typical forward voltage is 3.3V at 350mA. Driver circuits must be current-regulated, not voltage-regulated, to ensure stable optical output.

6.4 Relative Radiant Flux vs. Junction Temperature

This critical curve illustrates the negative impact of rising junction temperature (Tj) on light output. UV LED efficiency typically decreases as temperature increases. Effective thermal management through proper PCB layout (using thermal vias and adequate copper area) is paramount to maintaining high output and long-term reliability.

7. Assembly and Manufacturing Guidelines

7.1 Reflow Soldering Profile

A recommended reflow profile for lead-free (Pb-free) solder processes is provided. Key parameters include:

• Preheat: 150-200°C for up to 120 seconds.
• Peak Body Temperature: Maximum of 260°C.
• Time Above Liquidus: Recommended to be within 10 seconds (maximum of two reflow cycles allowed).
• A controlled, gradual cooling rate is advised. Rapid cooling is not recommended.
• Hand soldering with an iron should be limited to 300°C for a maximum of 3 seconds, for one time only.

7.2 Cleaning

If post-assembly cleaning is required, only specified chemicals should be used. Immersing the LED in ethyl alcohol or isopropyl alcohol at room temperature for less than one minute is acceptable. The use of unspecified chemicals may damage the package epoxy or lens.

7.3 Moisture Sensitivity

This product is classified as Moisture Sensitivity Level (MSL) 3 per JEDEC J-STD-020. Precautions are required to prevent popcorning during reflow.

• Sealed Bag: Store at ≤30°C and ≤90% RH. Use within one year of bag seal date.
• Opened Bag: Store at ≤30°C and ≤60% RH. Must be soldered within 168 hours (7 days) of exposure to factory ambient conditions.
• If the humidity indicator card shows 10% pink or higher, or the floor life is exceeded, baking at 60°C for at least 48 hours is required before use.

8. Packaging Specifications

The components are supplied on embossed carrier tape for automated handling.

• Tape Dimensions: Compliant with EIA-481-1-B specifications.
• Reel Size: Standard 7-inch (178mm) reel.
• Quantity per Reel: Maximum of 1500 pieces.
• Empty pockets are sealed with cover tape. The maximum allowable number of consecutive missing components is two.

9. Application Design Considerations

9.1 Drive Method

An LED is fundamentally a current-operated device. For stable and consistent performance, it must be driven by a constant current source, not a constant voltage source. A simple series resistor with a voltage source can be used for basic applications, but a dedicated LED driver IC or circuit is recommended for precise control, especially to manage thermal effects and ensure longevity.

9.2 Thermal Management

As shown in the performance curves, junction temperature directly impacts output efficiency and lifespan. Designers must implement effective thermal paths. This includes using a PCB with sufficient copper thickness, incorporating an array of thermal vias directly under the LED's thermal pad, and potentially adding external heatsinking if operating at high currents or in high ambient temperatures.

9.3 Optical Design

The 135-degree viewing angle provides a broad emission pattern. For applications requiring focused or collimated beams, secondary optics such as lenses or reflectors must be used. The material of these optics must be transparent to 405nm UV light; standard polycarbonate or acrylic may not be suitable and can degrade under prolonged UV exposure. UV-grade glass or specialized plastics are recommended.

10. Reliability and Application Notes

The LEDs are intended for use in standard electronic equipment. For applications where failure could jeopardize safety, health, or critical infrastructure (aviation, medical life-support, transportation control), a specific reliability assessment and consultation with the component manufacturer is mandatory prior to design-in. Proper adherence to the absolute maximum ratings, soldering guidelines, and storage conditions is essential to achieving the rated lifetime and reliability.