T20 Series Monochromatic LED Specification - 2016 Package - 2.0x1.6x0.75mm - 40mA - English Technical Document

1. Product Overview

The T20 series represents a family of high-performance, top-view monochromatic Light Emitting Diodes (LEDs) designed for general lighting applications. The specific model detailed in this document utilizes the compact 2016 surface-mount device (SMD) package. This series is engineered to deliver reliable and efficient light output in a thermally enhanced package suitable for automated assembly processes.

The core design philosophy focuses on balancing high luminous flux output with robust thermal management, enabling stable operation even under demanding conditions. The package is optimized for Pb-free reflow soldering, aligning with modern environmental and manufacturing standards, and is designed to remain compliant with RoHS directives.

2. Key Features and Applications

2.1 Product Features

• Top View White LED: Emits light perpendicular to the mounting plane, ideal for direct illumination.
• Thermally Enhanced Package Design: Improved thermal path from the LED chip to the PCB, helping to manage junction temperature and maintain performance and longevity.
• High Luminous Flux Output: Delivers bright light output for its compact size, with typical values varying by color (e.g., 10 lm for Green, 5.5 lm for Red at 40mA).
• High Current Capability: Rated for a forward current (IF) of 50 mA continuous, with a pulse rating (IFP) of 75 mA under specified conditions.
• Compact Package Size: The 2016 package measures approximately 2.0mm x 1.6mm, allowing for high-density PCB layouts.
• Wide Viewing Angle: A typical viewing angle (2θ1/2) of 120 degrees provides broad, even illumination.
• Pb-free Reflow Soldering Application: Compatible with standard SMT reflow processes using lead-free solder.
• RoHS Compliant: The product is designed and manufactured to meet Restriction of Hazardous Substances directives.

2.2 Target Applications

This LED series is versatile and finds use in various lighting scenarios, including:

• Interior Lighting: Integration into fixtures for residential, commercial, or industrial indoor spaces.
• Retrofits (Replacement): Serving as a direct replacement for older or less efficient light sources in existing fixtures.
• General Lighting: Providing primary or secondary illumination in a wide range of products.
• Architectural / Decorative Lighting: Used in accent lighting, signage, and aesthetic lighting designs where specific monochromatic colors are desired.

3. Technical Specifications Deep Dive

3.1 Electro-Optical and Electrical Characteristics

All measurements are specified at a junction temperature (Tj) of 25°C and a forward current (IF) of 40mA, unless otherwise noted. Tolerances must be considered for design margins.

3.1.1 Electro-Optical Characteristics

The luminous flux output is color-dependent. Typical and minimum values are provided:

• Red (RED): Typical 5.5 lm, Minimum 2.0 lm.
• Yellow (YELLOW): Typical 5.0 lm, Minimum 2.0 lm.
• Blue (BLUE): Typical 2.3 lm, Minimum 1.0 lm.
• Green (GREEN): Typical 10.0 lm, Minimum 8.0 lm.

Tolerance of luminous flux measurements is ±7%.

3.1.2 Electrical Characteristics

• Forward Voltage (VF): Varies by semiconductor material. Typical values range from 2.1V for Red to 3.0V for Green, with maximum limits up to 3.4V. Tolerance is ±0.1V.
• Reverse Current (IR): Maximum 10 μA at a reverse voltage (VR) of 5V for all colors.
• Viewing Angle (2θ1/2): Typical 120 degrees for all colors, defined as the off-axis angle where intensity is half the peak value.
• Electrostatic Discharge (ESD) Sensitivity: Rated at 1000V (Human Body Model, HBM) minimum for all colors, indicating a moderate level of ESD robustness for standard handling precautions.

3.2 Absolute Maximum Ratings

Stresses beyond these limits may cause permanent damage. Operating conditions should be designed to stay well within these ratings for reliability.

• Forward Current (IF): 50 mA (Continuous DC).
• Pulse Forward Current (IFP): 75 mA (Pulse width ≤100μs, Duty cycle ≤1/10).
• Reverse Voltage (VR): 5 V.
• Power Dissipation (PD): Red/Yellow: 130 mW; Blue/Green: 170 mW.
• Operating Temperature (Topr): -40°C to +105°C.
• Storage Temperature (Tstg): -40°C to +85°C.
• Junction Temperature (Tj): 110°C (Absolute maximum).
• Soldering Temperature (Tsld): Reflow profile with peak temperature of 230°C or 260°C for 10 seconds maximum.

Note: Exceeding these parameters may alter LED properties from the specified values.

4. Binning System Explanation

To ensure color and brightness consistency in production, LEDs are sorted into bins based on key parameters.

4.1 Luminous Flux Binning

At IF=40mA, Tj=25°C, flux is categorized into codes from AA to AG, with defined minimum and maximum lumen ranges. For example, code AF covers 10 to 14 lm. This allows designers to select LEDs matching their brightness requirements.

4.2 Wavelength Binning

The dominant wavelength is binned to control color purity. Ranges are specified for each color:

• Red: 620-625 nm, 625-630 nm, 630-635 nm.
• Yellow: 585-590 nm, 590-595 nm, 595-600 nm.
• Blue: 455-460 nm, 460-465 nm, 465-470 nm.
• Green: 520-525 nm, 525-530 nm, 530-535 nm.

Tolerance of wavelength measurement is ±1nm.

4.3 Forward Voltage Binning

Forward voltage is also binned to aid in circuit design for current regulation. Different code ranges are provided for lower voltage colors (Red/Yellow: 1.8-2.6V in steps) and higher voltage colors (Blue/Green: 2.6-3.4V in steps). Tolerance is ±0.1V.

4.4 Part Numbering System

The part number structure (e.g., T20**011F-*****) encodes specific attributes allowing precise identification and ordering. Key elements include Type code (20 for 2016 package), CCT/Color code, Color Rendering index (for white), number of serial/parallel chips, and a color code defining performance standards (e.g., F for ERP, M for ANSI).

5. Performance Curve Analysis

The datasheet references two key graphical representations of performance.

5.1 Color Spectrum

Fig 1. Color Spectrum: This graph would typically show the relative radiant power versus wavelength for each LED color (Red, Yellow, Blue, Green) at Tj=25°C. It visually defines the spectral purity and peak wavelength, which correlates directly with the perceived color. A narrow spectrum indicates high color saturation, which is typical for monochromatic LEDs.

5.2 Viewing Angle Distribution

Fig 2. Viewing Angle Distribution: This polar plot illustrates the spatial radiation pattern of the LED. For a top-view LED with a wide 120-degree viewing angle, the curve would show a broad, Lambertian-like distribution where intensity is highest at 0 degrees (perpendicular to the LED face) and decreases smoothly towards the edges. This pattern is crucial for designing optics and understanding illumination uniformity.

6. Mechanical and Package Information

6.1 Package Dimensions

The 2016 SMD package has nominal dimensions of 2.0mm in length, 1.6mm in width, and 0.75mm in height. A bottom-view diagram shows the solder pad layout and polarity marking. The anode and cathode pads are clearly identified, with the cathode typically indicated by a marking or a chamfered corner on the package. The dimensional tolerance is ±0.1mm unless otherwise specified.

6.2 Polarity Identification

Correct polarity is essential. The package includes a visual marker (e.g., a dot, line, or cut corner) to identify the cathode terminal. The solder pad pattern is asymmetrical to prevent incorrect placement during assembly.

7. Soldering and Assembly Guidelines

7.1 Reflow Soldering Profile

A detailed reflow profile is provided for lead-free soldering processes. Key parameters include:

• Preheat: Ramp from 150°C to 200°C over 60-120 seconds.
• Ramp-up Rate: Maximum 3°C/second to the peak temperature.
• Time Above Liquidus (T_L=217°C): 60-150 seconds.
• Peak Package Body Temperature (T_P): Maximum 260°C.
• Time within 5°C of T_P: Maximum 30 seconds.
• Ramp-down Rate: Maximum 6°C/second.
• Total Cycle Time: Maximum 8 minutes from 25°C to peak.

7.2 Important Cautions

1. Reflow Limit: It is recommended not to subject the LED to reflow soldering more than two times. If more than 24 hours pass after the first soldering before a second reflow, the LED may be damaged.
2. Post-Soldering Repair: Repairs (e.g., using a soldering iron) should not be performed on the LED after it has undergone reflow soldering, as localized heat can cause damage.
3. Power Dissipation: Care must be taken in the thermal design of the application to ensure the power dissipation does not exceed the absolute maximum rating, as this directly impacts junction temperature and lifetime.

8. Packaging and Ordering Information

8.1 Tape and Reel Packaging

For automated pick-and-place assembly, LEDs are supplied on embossed carrier tape and reels.

• Tape Dimensions: Specified to ensure compatibility with feeder equipment.
• Reel Capacity: Maximum 5000 pieces per reel.
• Cumulative Tolerance: The cumulative tolerance over 10 pitches is ±0.2mm.

8.2 Outer Packaging

Reels are further packaged in boxes for shipment and storage.

• Box Capacity: Standard configurations include 10 reels per box, with options for 30 or 60 reels per box.
• Labeling: Boxes and inner bags are labeled with critical information including Part Number, Manufacturing Date Code, Lot Number, Quantity, and product parameters. Desiccant is included in moisture barrier bags to protect the components.

9. Application Design Considerations

9.1 Driving the LED

LEDs are current-driven devices. A constant current source is highly recommended over a constant voltage source to ensure stable light output and prevent thermal runaway. The driver should be designed to provide the desired operating current (e.g., 40mA for nominal specs) while staying within the Absolute Maximum Ratings. The forward voltage binning information is useful for calculating the necessary voltage compliance of the driver.

9.2 Thermal Management

Despite the thermally enhanced package, effective heat sinking is critical for performance and longevity. The PCB layout should use adequate copper area (thermal pads) connected to the LED's solder pads to conduct heat away from the junction. Operating at or near the maximum current rating will generate more heat, necessitating more aggressive thermal design to keep the junction temperature (Tj) well below its maximum limit of 110°C.

9.3 Optical Integration

The wide 120-degree viewing angle makes these LEDs suitable for applications requiring broad, diffuse illumination without secondary optics. For focused beams, primary optics (lenses) or reflectors will be required. The small source size of the 2016 package is advantageous for optical control.

10. Technical Comparison and Differentiation

Within the landscape of monochromatic SMD LEDs, the T20/2016 series positions itself with specific advantages:

• vs. Smaller Packages (e.g., 0603, 0402): Offers significantly higher light output and better thermal performance due to its larger size, making it suitable for higher-power general lighting tasks rather than just indicator functions.
• vs. Larger Packages (e.g., 5050, 7070): Provides a more compact footprint for space-constrained designs while still delivering appreciable flux, offering a balance between size and performance.
• Thermal Enhancement: The explicit mention of a thermally enhanced package design is a key differentiator from many standard LED packages, implying better reliability under continuous operation.
• Comprehensive Binning: The detailed binning for flux, wavelength, and voltage provides designers with the tools needed for high-consistency applications, which may not be as rigorously defined for all LED series.

11. Frequently Asked Questions (FAQ)

11.1 What is the difference between the "Typ" and "Min" luminous flux values?

The "Typ" (Typical) value represents the average or most common output from production under test conditions. The "Min" (Minimum) value is the guaranteed lower limit; any LED meeting the specification will perform at or above this level. Designers should use the "Min" value for worst-case scenario calculations to ensure their application meets minimum brightness requirements.

11.2 Can I drive this LED at its maximum current of 50mA continuously?

While the Absolute Maximum Rating is 50mA, continuous operation at this level will generate maximum heat and likely push the junction temperature towards its limit unless exceptional thermal management is employed. For optimal longevity and stable performance, it is advisable to operate at or below the test current of 40mA, or to carefully model the thermal performance at 50mA.

11.3 How do I interpret the part number to order the correct LED?

You must reference the Part Numbering System table. You need to define each placeholder (X1 through X10) based on your requirements: package type (20 for 2016), desired color/wavelength, required flux bin, voltage bin, and the specific color code (e.g., F for ERP standards). Contact your supplier with the fully constructed part number for precise ordering.

11.4 Why is there a caution against a second reflow if 24 hours have passed?

This is likely related to moisture sensitivity. SMD packages can absorb moisture from the atmosphere. During a rapid reflow, this trapped moisture can vaporize and cause internal delamination or cracking ("popcorning"). If the device is not soldered within a specific timeframe after being removed from its moisture-proof bag, or if it is exposed for too long, it may require a baking process before a second reflow to drive out the moisture. The caution simplifies this by recommending against the practice altogether unless specific handling procedures are followed.

12. Practical Application Example

Scenario: Designing a decorative RGB wall washer light.

1. Component Selection: An engineer selects the Red, Green, and Blue LEDs from the T20 series. They choose specific wavelength bins (e.g., 625-630nm Red, 525-530nm Green, 465-470nm Blue) to achieve the desired color gamut. They also select a mid-range flux bin (e.g., code AC or AD) for balanced brightness.
2. Circuit Design: Three separate constant-current drivers are designed, one for each color channel, set to 40mA. The driver output voltage compliance is sized using the maximum VF from the datasheet (e.g., 3.4V for Green/Blue) plus some headroom.
3. PCB Layout: The LEDs are placed on the PCB with generous copper pours connected to their thermal pads. The layout follows the recommended solder pad pattern from the dimension diagram to ensure proper soldering and alignment.
4. Thermal Analysis: Given the enclosed fixture, the engineer calculates the expected thermal resistance from junction to ambient. They ensure that even with multiple LEDs on, the estimated Tj remains below 85°C for long life.
5. Assembly: The PCB assembly follows the specified reflow profile precisely. The LEDs are used within the recommended timeframe after the bag is opened to avoid moisture issues.

13. Operating Principle Introduction

A Light Emitting Diode (LED) is a semiconductor device that emits light when an electric current passes through it. This phenomenon is called electroluminescence. In a monochromatic LED like those in the T20 series, a semiconductor chip (typically made of materials like AlInGaP for Red/Yellow or InGaN for Blue/Green) is housed within the package. When a forward voltage exceeding the chip's bandgap voltage is applied, electrons and holes recombine in the active region of the semiconductor, releasing energy in the form of photons (light). The specific material composition and structure of the semiconductor determine the wavelength (color) of the emitted light. The package serves to protect the chip, provide electrical connections, and includes a phosphor (for white LEDs) or a clear dome/lens to shape the light output. The 2016 package's design focuses on efficiently extracting this light and managing the heat generated by non-radiative recombination and electrical resistance.

14. Technology Trends

The development of SMD LEDs like the T20 series follows several key industry trends:

• Increased Efficiency (lm/W): Ongoing material science and chip design improvements continuously push for higher luminous efficacy, meaning more light output per unit of electrical power consumed.
• Miniaturization with Power: The trend is to pack higher light output into ever-smaller packages, as seen with successors to the 2016, like the 1010 or even smaller chips. This enables sleeker product designs.
• Enhanced Reliability and Thermal Management: As power densities increase, advanced package materials (e.g., ceramic substrates, high-thermal-conductivity molding compounds) are being adopted to better manage junction temperature, which is the primary factor affecting LED lifespan.
• Standardization and Binning: The industry moves towards more precise and standardized binning systems to provide designers with predictable performance, crucial for applications requiring color and brightness consistency across thousands of units.
• Smart and Integrated LEDs: A growing trend is the integration of control circuitry (drivers, sensors, communication interfaces) directly into the LED package, creating "smart" LEDs for IoT and connected lighting systems, though this is more prevalent in white and RGB packages.