Green SMD LED Chip RF-GNB190TS-CF Specification - Size 1.6x0.8x0.7mm - Voltage 2.8-3.5V - Power 105mW - English Technical Document

1. Product Overview

This document details the technical specifications for a compact, surface-mount (SMD) light-emitting diode (LED) emitting green light. The device is designed for general indicator and illumination purposes in various electronic applications. Its primary characteristics include a small footprint, wide viewing angle, and compliance with standard SMT assembly processes.

1.1 General Description

The component is a color LED fabricated using a green semiconductor chip. It is housed in a compact package with dimensions of 1.6mm in length, 0.8mm in width, and 0.7mm in height. This miniature form factor makes it suitable for densely populated printed circuit boards (PCBs) where space is at a premium.

1.2 Key Features and Core Advantages

• Extremely Wide Viewing Angle: Provides uniform light distribution over a broad area, ideal for status indicators.
• SMT Compatibility: Fully compatible with standard surface-mount technology (SMT) assembly and reflow soldering processes.
• Moisture Sensitivity: Classified as Moisture Sensitivity Level (MSL) 3, indicating a moderate level of sensitivity to ambient humidity.
• Environmental Compliance: The product is compliant with the Restriction of Hazardous Substances (RoHS) directive.

1.3 Target Market and Application

This LED is targeted at a broad range of consumer electronics, industrial controls, and automotive interior applications. Typical use cases include:

• Optical status and power indicators.
• Backlighting for switches, symbols, and small displays.
• General-purpose decorative or functional lighting in compact devices.

2. In-Depth Technical Parameter Analysis

All electrical and optical characteristics are measured at a standard junction temperature (Ts) of 25°C. It is critical to note that these parameters can vary with operating temperature.

2.1 Electro-Optical Characteristics

The primary performance metrics define the LED's behavior under standard operating conditions (IF=20mA).

Forward Voltage (V_F): This parameter, which has a significant impact on driver circuit design, is binned into multiple grades ranging from 2.8V to 3.5V. Designers must select the appropriate bin to ensure consistent brightness and power consumption across a production run.

Dominant Wavelength (λ_D): Defines the perceived color of the light. The LED is available in specific wavelength bins from 515nm to 530nm, covering various shades of green. This allows for precise color matching in applications where color consistency is critical.

Luminous Intensity (I_V): A measure of the LED's brightness. It is categorized into bins with minimum values ranging from 260 mcd to 700 mcd (at 20mA), allowing selection based on required brightness levels. The viewing angle is specified as a typical 140 degrees, confirming the wide-angle emission.

Other Parameters: The spectral half bandwidth is approximately 15nm. The reverse leakage current (I_R) is guaranteed to be below 10 µA at 5V reverse bias. The junction-to-solder point thermal resistance (R_THJ-S) is specified at a maximum of 450 °C/W, which is a key figure for thermal management calculations.

2.2 Absolute Maximum Ratings

These are stress limits that must not be exceeded under any conditions to prevent permanent damage.

• Maximum Power Dissipation (P_d): 105 mW.
• Maximum Continuous Forward Current (I_F): 30 mA.
• Maximum Peak Pulse Current (I_FP): 60 mA (at 0.1ms pulse width, 1/10 duty cycle).
• Electrostatic Discharge (ESD) Tolerance: 1000V (Human Body Model).
• Operating & Storage Temperature Range: -40°C to +85°C.
• Maximum Junction Temperature (T_j): 95°C. This is the most critical limit for reliability; the operating current must be derated to ensure T_j stays below this value.

2.3 Binning System Explanation

The product employs a comprehensive binning system to ensure consistency.

• Voltage Binning (V_FG1 to V_J1): LEDs are sorted based on their forward voltage drop at 20mA. This allows designers to source parts with tightly controlled voltage characteristics, simplifying current-limiting resistor calculations and improving power supply efficiency.
• Wavelength Binning (D10 to F20): LEDs are sorted into specific 2.5nm wavelength bands. This is essential for applications requiring precise color points or uniform appearance across multiple LEDs.
• Luminous Intensity Binning (1AU to 1CM): Parts are grouped by their minimum luminous output. This enables brightness matching in multi-LED arrays or consistent indicator brightness across different product units.

3. Performance Curve Analysis

The provided graphs offer insights into the LED's behavior under non-standard conditions.

3.1 IV Curve and Relative Intensity

The Forward Voltage vs. Forward Current (IV) curve shows the non-linear relationship typical of a diode. The Relative Intensity vs. Forward Current curve demonstrates how light output increases with current, but designers must consider efficiency drop and thermal effects at higher currents.

3.2 Temperature Dependence

The Pin Temperature vs. Relative Intensity graph shows the negative impact of rising temperature on light output (thermal quenching). The Pin Temperature vs. Forward Current curve indicates that forward voltage decreases as temperature rises, which is a characteristic of semiconductor diodes. These graphs highlight the importance of effective thermal management in the PCB design.

3.3 Spectral and Radiation Characteristics

The Dominant Wavelength vs. Forward Current curve shows minimal shift with current for this LED type. The Relative Intensity vs. Wavelength graph depicts the spectral power distribution, centered around the dominant wavelength with a ~15nm bandwidth. The radiation pattern diagram visually confirms the very wide, lambertian-like emission profile.

4. Mechanical and Packaging Information

4.1 Package Dimension and Land Pattern

The mechanical drawings specify the exact outer dimensions and lead geometry. Key features include the anode and cathode identification marks. A recommended solder pad layout (land pattern) is provided to ensure reliable solder joint formation and proper alignment during reflow. The polarity is clearly marked on the package itself.

4.2 Packaging for Assembly

The product is supplied in tape-and-reel packaging compatible with automated pick-and-place machines. Specifications for the carrier tape dimensions (for component retention and spacing) and the reel dimensions are detailed. Labeling specifications for the reel are also defined to ensure traceability.

4.3 Moisture Handling and Storage

Due to its MSL 3 rating, the LEDs are packed with desiccant in a moisture barrier bag when shipped. Once the sealed bag is opened, the components must be subjected to a bake-out process if not used within the specified floor life (typically 168 hours at ≤ 30°C/60% RH for MSL 3) to prevent popcorning during reflow soldering.

5. Soldering and Assembly Guidelines

5.1 SMT Reflow Soldering Profile

Specific instructions are provided for the reflow soldering process. This includes the critical temperature profile (preheat, soak, reflow peak temperature, and cooling rates) that must be followed to prevent thermal damage to the LED package or the epoxy lens while ensuring reliable solder connections. The maximum recommended peak temperature is typically around 260°C, but the exact profile should be validated.

5.2 Handling and Usage Precautions

• Always observe proper ESD precautions during handling and assembly.
• Use the recommended solder paste and stencil aperture design.
• Avoid applying mechanical stress to the LED body.
• Do not exceed the absolute maximum ratings, especially junction temperature.
• When designing the driver circuit, use a current-limiting resistor or constant-current driver; never connect the LED directly to a voltage source.

6. Application Design Considerations

6.1 Driver Circuit Design

Due to the diode's exponential IV characteristic, a series current-limiting resistor is the simplest driving method for low-current indicator use. The resistor value is calculated as R = (V_supply - V_F) / I_F, using the maximum V_F from the selected bin to ensure current does not exceed the desired level. For higher power or precision applications, a constant-current driver is recommended to maintain stable brightness over voltage and temperature variations.

6.2 Thermal Management

With a thermal resistance of 450 °C/W, the temperature rise can be significant. For example, at 20mA and a V_F of 3.2V (64mW power), the temperature rise from the solder point to the junction would be approximately 29°C. Adequate PCB copper area (thermal pads connected to the cathode) is essential to dissipate heat and keep the junction temperature within safe limits, thereby ensuring long-term reliability and stable light output.

7. Technical Comparisons and Differentiation

Compared to larger SMD LEDs (e.g., 3528 or 5050 packages), this 1608 device offers a significantly smaller footprint, enabling miniaturization. Its wide 140-degree viewing angle is superior to narrower-angle LEDs for panel indication. The availability of multiple electrical and optical bins provides designers with flexibility for cost vs. performance optimization and for achieving high consistency in their end products.

8. FAQs Based on Technical Parameters

Q: What current should I drive this LED at?
A: The standard test condition is 20mA, which is a safe and typical operating point. The maximum continuous current is 30mA, but operation at this level requires careful thermal design.

Q: How do I choose the right bin?
A: Select the V_F bin based on your power supply voltage and desired driver efficiency. Choose the wavelength and intensity bins based on your application's color and brightness requirements. Using tighter bins increases consistency but may affect cost and availability.

Q: Is a heat sink required?
A> For continuous operation at 20mA or below in a typical indoor environment, the thermal pad on the PCB is usually sufficient. For higher currents, extended duty cycles, or high ambient temperatures, additional thermal management (more copper, airflow) should be considered.

9. Practical Application Example

Consider designing a status indicator panel with 10 uniform green LEDs. To ensure consistency:
1. Select LEDs from the same luminous intensity bin (e.g., 1CM for high brightness) and the same dominant wavelength bin (e.g., E20 for a specific green hue).
2. For a 5V supply, calculate the current-limiting resistor using the maximum V_F from the selected voltage bin (e.g., V_F max = 3.2V for I1 bin). R = (5V - 3.2V) / 0.020A = 90 Ohms. Use a 91-ohm standard value resistor.
3. Design the PCB with a connected copper pour under the LED's cathode pad to act as a heat spreader.
This approach guarantees visually matched indicators.

10. Principle of Operation and Technology Trends

Operating Principle: This LED is based on a semiconductor chip (likely InGaN). When a forward voltage is applied, electrons and holes recombine in the active region, releasing energy in the form of photons (light) with a wavelength corresponding to the green spectrum.

Industry Trends: The drive towards miniaturization in electronics continues to push for smaller package sizes like this 1608. Other trends include higher efficiency (more lumens per watt), improved color rendering, and the integration of smarter features, though this particular component remains a standard, discrete indicator LED focused on cost-effective reliability.