SMD LED 19-217/GHC-YR1S2/3T Specification - Brilliant Green - 120° Viewing Angle - 3.3V Typ. - 20mA - English Technical Document

1. Product Overview

The 19-217/GHC-YR1S2/3T is a surface-mount device (SMD) LED designed for modern electronic applications requiring compact size, high reliability, and efficient assembly. This component represents a significant advancement over traditional lead-frame LEDs, enabling substantial reductions in board space, increased packing density, and ultimately contributing to the miniaturization of end equipment. Its lightweight construction makes it particularly suitable for applications where space and weight are critical constraints.

The LED emits a brilliant green light, achieved through an InGaN (Indium Gallium Nitride) semiconductor chip encapsulated in a water-clear resin. This combination provides high luminous intensity and excellent color purity. The device is supplied in industry-standard 8mm tape on 7-inch diameter reels, ensuring full compatibility with high-speed automatic pick-and-place equipment used in modern electronics manufacturing.

1.1 Core Advantages and Compliance

The product offers several key advantages that align with contemporary manufacturing and environmental standards:

• Miniaturization: The SMD package is significantly smaller than leaded alternatives, directly enabling smaller PCB designs and higher component density.
• Automation Friendly: Packaged on tape-and-reel, it is fully compatible with automated assembly processes, reducing labor costs and improving placement accuracy.
• Environmental Compliance: The device is manufactured as a Pb-free (lead-free) component. It is designed to remain compliant with the EU's Restriction of Hazardous Substances (RoHS) directive.
• REACH & Halogen-Free: The product complies with the EU's REACH regulation concerning chemicals. It is also classified as halogen-free, with bromine (Br) and chlorine (Cl) content each below 900 ppm, and their combined total below 1500 ppm.
• Soldering Process Compatibility: It is suitable for both infrared and vapor phase reflow soldering processes, offering flexibility in production line setup.

2. Technical Parameter Deep-Dive

This section provides a detailed, objective analysis of the LED's electrical, optical, and thermal specifications as defined in the absolute maximum ratings and electro-optical characteristics tables.

2.1 Absolute Maximum Ratings

These ratings define the stress limits beyond which permanent damage to the device may occur. Operation at or beyond these limits is not advised.

• Continuous Forward Current (I_F): 25 mA. This is the maximum DC current that can be applied continuously to the LED anode.
• Peak Forward Current (I_FP): 50 mA. This higher current is permissible only under pulsed conditions, specifically at a duty cycle of 1/10 and a frequency of 1 kHz. Exceeding the continuous rating, even briefly in DC operation, risks catastrophic failure.
• Power Dissipation (P_d): 95 mW. This is the maximum power the package can dissipate as heat, calculated as Forward Voltage (V_F) multiplied by Forward Current (I_F). Designers must ensure operating conditions stay within this limit, considering ambient temperature.
• Electrostatic Discharge (ESD): Human Body Model (HBM) 150V. This is a relatively low ESD tolerance. Strict ESD handling procedures (use of grounded workstations, wrist straps, etc.) are essential during assembly and handling to prevent latent or immediate damage.
• Temperature Ranges:
  • Operating Temperature (T_opr): -40°C to +85°C. The device is guaranteed to function within this ambient temperature range.
  • Storage Temperature (T_stg): -40°C to +90°C.
• Soldering Temperature (T_sol):
  • Reflow Soldering: Peak temperature of 260°C for a maximum of 10 seconds.
  • Hand Soldering: Iron tip temperature not exceeding 350°C for a maximum of 3 seconds per terminal.

2.2 Electro-Optical Characteristics

These parameters, measured at a standard test condition of 25°C ambient temperature and a forward current of 20mA, define the device's performance.

• Luminous Intensity (I_v): Ranges from a minimum of 112 mcd to a maximum of 285 mcd. The specific value is determined by the product's bin code (see Section 3). The typical value is not stated, implying significant variation across the production spread.
• Viewing Angle (2θ_1/2): 120 degrees (typical). This is the full angle at which the luminous intensity drops to half of its peak value. A 120° angle indicates a very wide viewing pattern, suitable for applications requiring broad illumination or visibility from wide angles.
• Peak Wavelength (λ_p): 518 nm (typical). This is the wavelength at which the spectral power distribution is at its maximum.
• Dominant Wavelength (λ_d): Ranges from 520 nm to 535 nm. This is the single wavelength perceived by the human eye as the color of the light. It is closely related to chromaticity coordinates and is also subject to binning.
• Spectral Bandwidth (Δλ): 35 nm (typical). This is the width of the emitted spectrum at half of the maximum intensity (Full Width at Half Maximum - FWHM). A value of 35nm is characteristic of a relatively pure green color from an InGaN chip.
• Forward Voltage (V_F): Ranges from 2.7V (min) to 3.7V (max), with a typical value of 3.3V at I_F=20mA. This parameter is crucial for circuit design, particularly for calculating the current-limiting resistor value: R = (V_supply - V_F) / I_F.
• Reverse Current (I_R): Maximum of 50 μA when a reverse voltage (V_R) of 5V is applied. LEDs are not designed to be reverse-biased, and this parameter indicates the level of leakage under such a condition.

Critical Note on Tolerances: The datasheet specifies a luminous intensity tolerance of ±11% and a dominant wavelength tolerance of ±1nm. These are inherent manufacturing variations that are managed through the binning system described next.

3. Binning System Explanation

To manage natural variations in semiconductor manufacturing, LEDs are sorted (binned) based on key performance parameters. This allows designers to select parts that meet specific application requirements for brightness and color.

3.1 Luminous Intensity Binning

The LED is categorized into four distinct bins based on its measured luminous intensity at 20mA. The bin code is part of the product ordering code (e.g., S2 in GHC-YR1S2/3T).

• Bin R1: 112 mcd (Min) to 140 mcd (Max)
• Bin R2: 140 mcd to 180 mcd
• Bin S1: 180 mcd to 225 mcd
• Bin S2: 225 mcd to 285 mcd

Selecting a higher bin code (e.g., S2) ensures a brighter LED, which may be necessary for applications in high-ambient-light conditions or where maximum visibility is critical.

3.2 Dominant Wavelength Binning

The color (hue) of the green light is controlled by binning the dominant wavelength. This ensures color consistency within a batch of LEDs.

• Bin X: 520 nm (Min) to 525 nm (Max) – A greener, slightly shorter wavelength.
• Bin Y: 525 nm to 530 nm
• Bin Z: 530 nm to 535 nm – A slightly more yellowish-green, longer wavelength.

The specific bin (e.g., Y in GHC-YR1S2/3T) should be specified when color matching between multiple LEDs is important for the application's aesthetics or functional requirements.

4. Performance Curve Analysis

The datasheet provides several typical characteristic curves that illustrate how the LED's performance changes with operating conditions. Understanding these is key to robust design.

• Relative Luminous Intensity vs. Forward Current: This curve shows that light output is approximately proportional to forward current in the typical operating range. However, driving the LED above its rated current leads to super-linear heat generation and efficiency droop, reducing lifespan.
• Relative Luminous Intensity vs. Ambient Temperature: The light output of an LED decreases as the junction temperature increases. This curve quantifies that derating. For high-reliability applications or those operating in hot environments, thermal management (adequate PCB copper area, possible heatsinking) is necessary to maintain brightness.
• Forward Voltage vs. Forward Current: This is the diode's IV curve. It is non-linear, showing the typical exponential relationship. The voltage rises sharply once the turn-on threshold is passed. The specified V_F at 20mA is the operating point on this curve.
• Spectral Distribution: While not a detailed graph, the peak wavelength (518nm) and bandwidth (35nm) define a roughly Gaussian-shaped curve centered on green light.
• Radiation Pattern: The polar diagram confirms the 120° viewing angle, showing a Lambertian-like distribution where intensity is highest at 0° (perpendicular to the LED face) and falls off symmetrically to the sides.

5. Mechanical and Packaging Information

5.1 Package Dimensions

The LED features a standard SMD package. The dimensional drawing provides critical measurements for PCB land pattern (footprint) design, including body length, width, height, and the location and size of the solder pads. Adherence to these dimensions is necessary for reliable soldering and proper alignment during automated assembly. All unspecified tolerances are ±0.1mm.

5.2 Polarity Identification

The cathode is typically marked on the device, often by a green dot, a notch in the package, or a differently shaped pad. The PCB footprint should include a corresponding polarity marker (such as a silkscreen outline or a dot) to prevent incorrect placement. Connecting the LED in reverse bias, while limited to 5V per the I_R spec, should be avoided in circuit design.

6. Soldering and Assembly Guide

Proper handling and soldering are critical to achieving the reliability promised by the component specifications.

6.1 Storage and Moisture Sensitivity

The LEDs are packaged in a moisture-resistant bag with desiccant to prevent absorption of atmospheric moisture.

• Do not open the moisture-proof bag until the components are ready for use on the production line.
• After opening, unused LEDs should be stored in an environment of 30°C or less and 60% relative humidity or less.
• The "floor life" after opening the bag is 168 hours (7 days). If not used within this time, they must be re-baked according to the specified profile (typically 125°C for 24 hours) and re-bagged with fresh desiccant.
• If the desiccant indicator has changed color (e.g., from blue to pink), baking is required before use.

6.2 Reflow Soldering Profile

The recommended Pb-free reflow profile is crucial for forming reliable solder joints without damaging the LED.

• Pre-heating: Ramp from ambient to 150-200°C over 60-120 seconds. This gradual heating minimizes thermal shock.
• Soak/Preflow: Maintain between 150-200°C. This allows the PCB and components to thermally equalize and activates the flux.
• Reflow: Rapid ramp-up (max 6°C/sec) into the reflow zone. The peak temperature must reach above 217°C (the melting point of typical Pb-free solder) for 60-150 seconds. The absolute maximum peak is 260°C, and the time above 255°C must not exceed 30 seconds. The time at the actual peak (e.g., 260°C) must not exceed 10 seconds.
• Cooling: Controlled cool-down at a maximum rate of 3°C/sec to minimize stress on the solder joints.

Critical Restrictions:

1. Reflow should not be performed more than two times. A third reflow cycle risks damaging the LED's internal wire bonds or the epoxy encapsulant.
2. Avoid mechanical stress on the LED during the heating and cooling phases of soldering.
3. Do not warp or bend the PCB after soldering, as this can crack the solder joints or the LED itself.

6.3 Hand Soldering and Rework

Hand soldering is permissible but carries higher risk.

• Use a temperature-controlled soldering iron set to a maximum of 350°C.
• Apply heat to each terminal for a maximum of 3 seconds.
• Use an iron with a power rating of 25W or less to avoid excessive heat transfer.
• Allow a cooling interval of at least 2 seconds between soldering each terminal.
• Repair/Rework is strongly discouraged. If absolutely unavoidable, use a specialized double-head soldering iron designed for SMD components to simultaneously heat both terminals and lift the part without twisting. Always verify that the LED's characteristics have not been degraded after rework.

7. Packaging and Ordering Information

7.1 Reel and Tape Specifications

The product is supplied for automated assembly:

• Carrier Tape: 8mm wide tape.
• Reel: 7-inch (178mm) diameter reel.
• Quantity per Reel: 3000 pieces.

Detailed dimensional drawings for the carrier tape pockets and the reel are provided to ensure compatibility with feeder mechanisms on placement machines.

7.2 Label Explanation

The reel label contains several key identifiers:

• P/N: The manufacturer's product number (e.g., 19-217/GHC-YR1S2/3T).
• CAT: Luminous Intensity Rank (the bin code, e.g., S2).
• HUE: Chromaticity Coordinates & Dominant Wavelength Rank (the color bin, e.g., Y).
• REF: Forward Voltage Rank.
• LOT No: Traceability lot number.

8. Application Suggestions

8.1 Typical Application Scenarios

Based on its wide viewing angle, green color, and SMD format, this LED is well-suited for:

• Backlighting: Illumination of symbols, icons, or panels on dashboards, control panels, switches, and keypads.
• Status Indicators: Power, activity, or mode indicators in telecommunications equipment (telephones, fax machines), consumer electronics, and computer peripherals.
• LCD Backlighting: As a discrete light source for small, flat panel LCDs where edge-lighting is employed.
• General Purpose Indication: Any application requiring a compact, reliable, bright green indicator light.

8.2 Critical Design Considerations

1. Current Limiting is Mandatory: An LED is a current-driven device. You must use a series current-limiting resistor. The forward voltage has a range (2.7V-3.7V). A slight increase in supply voltage above V_F can cause a large, potentially destructive increase in current if not limited by a resistor. Calculate the resistor value using the maximum V_F from the datasheet to ensure safe operation under all conditions: R_min = (V_supply - V_{F_max}) / I_{F_desired}.
2. Thermal Management: While power dissipation is low (95mW max), operating at high ambient temperatures or high currents will reduce light output and lifespan. Provide adequate copper area on the PCB connected to the LED's thermal pads (if any) or the cathode/anode traces to act as a heatsink.
3. ESD Protection: Implement ESD protection on input lines if the LED is connected to user-accessible ports (like buttons or connectors). Always follow ESD-safe handling procedures during assembly.

9. Application Restrictions and Reliability Note

The datasheet includes a critical disclaimer regarding high-reliability applications. This LED is designed and specified for general commercial and industrial use. It may not be suitable for applications where failure could lead to serious injury, loss of life, or significant property damage without additional qualification and possibly a different product variant designed for such environments.

Examples of such restricted applications include:

• Military and aerospace systems (especially flight-critical).
• Automotive safety and security systems (e.g., airbag indicators, brake lights).
• Medical life-support or critical diagnostic equipment.

For these applications, it is imperative to consult with the component manufacturer to discuss specific requirements, potential deratings, and the availability of products qualified to higher reliability standards (such as AEC-Q100 for automotive). This datasheet guarantees performance only within the stated specifications and not for use beyond them or in unspecified conditions.

10. FAQ Based on Technical Parameters

Q: What resistor value should I use with a 5V supply?
A: Using the worst-case maximum V_F of 3.7V and a desired I_F of 20mA: R = (5V - 3.7V) / 0.020A = 65 ohms. The nearest standard value is 68 ohms. The power rating of the resistor is (5V-3.3V)^2 / 68Ω ≈ 0.042W, so a standard 1/8W (0.125W) resistor is sufficient.

Q: Can I drive this LED at 30mA for more brightness?
A: No. The Absolute Maximum Rating for continuous forward current is 25mA. Operating at 30mA exceeds this rating, which will significantly reduce the LED's lifespan and may cause immediate failure due to overheating. Always operate within the specified limits.

Q: The LED is dimmer in my final product than a sample. Why?
A> Common causes are: 1) Operating at a higher ambient temperature than 25°C, causing intensity drop. 2) Using a resistor value that results in a lower actual forward current. 3) Voltage drop in the supply lines. 4) Selecting an LED from a lower luminous intensity bin (e.g., R1 instead of S2).

Q: How do I ensure consistent green color across multiple units in my product?
A> You must specify and order LEDs from the same Dominant Wavelength bin (e.g., all from Bin Y). Mixing bins (X, Y, Z) will result in visible color differences between LEDs.

11. Design-in Case Study Example

Scenario: Designing a status indicator panel for a network router. The panel has 10 identical green "Link Active" indicators.

Design Choices:

1. Brightness Consistency: To ensure all 10 indicators appear equally bright, the designer specifies the highest luminous intensity bin available (S2: 225-285 mcd) in the purchase order.
2. Color Consistency: To prevent one indicator from looking slightly more yellow or blue-green than another, the designer also specifies a single dominant wavelength bin (e.g., Bin Y).
3. Circuit Design: The router's internal logic supply is 3.3V. Using the typical V_F of 3.3V, the voltage drop across a current-limiting resistor would be nearly zero. Therefore, a constant-current LED driver IC is chosen instead of a simple resistor to ensure stable brightness regardless of V_F variation and to improve efficiency. The driver is set to provide 20mA.
4. PCB Layout: The PCB footprint is designed exactly per the package dimension drawing. Additional copper pour is connected to the LED's solder pads on inner layers to aid in heat dissipation, as the router enclosure may get warm.
5. Assembly: The LEDs are ordered on 8mm tape-and-reel. The manufacturing team follows the specified reflow profile precisely, ensuring the peak temperature does not exceed 260°C. The moisture-sensitive devices are baked before use because the PCB assembly process involves multiple passes.

This systematic approach, based on a thorough understanding of the datasheet, results in a reliable, professional-looking product with uniform indicator performance.