SMD LED 12-21C/T3D-CP1Q2B12Y/2C Datasheet - Package 2.0x1.25x0.8mm - Voltage 2.7-3.4V - Power 40mW - Pure White - English Technical Document

1. Product Overview

The 12-21C/T3D-CP1Q2B12Y/2C is a compact, surface-mount LED designed for modern electronic applications requiring reliable, low-profile illumination. This component represents a significant advancement over traditional lead-frame LEDs, enabling substantial miniaturization and efficiency improvements in end-product design.

1.1 Core Advantages and Product Positioning

The primary advantage of this LED is its extremely small footprint. The package dimensions allow for higher packing density on printed circuit boards (PCBs), directly contributing to reduced board size and, consequently, smaller final equipment. Its lightweight nature makes it particularly suitable for portable and miniature applications where weight and space are critical constraints. The product is positioned as a versatile, general-purpose indicator and backlighting solution, compliant with major environmental and safety standards including RoHS, REACH, and Halogen-Free requirements (Br <900 ppm, Cl <900 ppm, Br+Cl < 1500 ppm).

1.2 Target Market and Applications

This LED is engineered for a broad range of applications across consumer electronics, automotive, and telecommunications sectors. Key application areas include backlighting for instrument clusters, switches, and symbols; indicator and backlighting functions in telecommunication devices such as telephones and fax machines; and general flat backlighting for LCD panels. Its compatibility with automatic placement equipment and standard infrared/vapor phase reflow soldering processes makes it ideal for high-volume manufacturing.

2. In-Depth Technical Parameter Analysis

A thorough understanding of the electrical and optical parameters is essential for reliable circuit design and ensuring long-term performance.

2.1 Absolute Maximum Ratings

These ratings define the stress limits beyond which permanent damage to the device may occur. They are not intended for normal operation.

• Reverse Voltage (V_R): 5 V. Exceeding this voltage in reverse bias can cause immediate junction breakdown.
• Forward Current (I_F): 10 mA (Continuous).
• Peak Forward Current (I_FP): 100 mA (Duty Cycle 1/10 @ 1 kHz). This allows for brief pulses of higher current, useful for multiplexing or achieving higher instantaneous brightness.
• Power Dissipation (P_d): 40 mW. This is the maximum power the package can dissipate as heat without exceeding its thermal limits.
• Electrostatic Discharge (ESD): Human Body Model (HBM) 150 V. This indicates moderate sensitivity to ESD, necessitating proper handling procedures in an ESD-protected environment.
• Operating Temperature (T_opr): -40°C to +85°C. This wide range suits automotive and industrial environments.
• Storage Temperature (T_stg): -40°C to +90°C.

2.2 Electro-Optical Characteristics (T_a = 25°C)

These parameters are measured under standard test conditions and define the device's performance.

• Luminous Intensity (I_v): 45.0 mcd (Min), 112.0 mcd (Max) at I_F = 5 mA. The typical value is not specified, indicating performance is managed through the binning system.
• Viewing Angle (2θ_1/2): 110 degrees (Typical). This wide viewing angle is characteristic of a diffused yellow resin package, providing a broad, even light distribution.
• Forward Voltage (V_F): 2.70 V (Min), 3.40 V (Max) at I_F = 5 mA. The tight tolerance of ±0.05V per bin ensures consistent voltage drop across production lots.
• Reverse Current (I_R): 50 μA (Max) at V_R = 5 V. This parameter is for test purposes only; the device is not intended for reverse-bias operation.

3. Binning System Explanation

The product is classified into bins based on key performance parameters to guarantee consistency for the end-user. This allows designers to select LEDs with tightly grouped characteristics for uniform appearance in an array.

3.1 Luminous Intensity Binning

LEDs are sorted into four bins (P1, P2, Q1, Q2) based on measured luminous intensity at 5 mA. The bins range from a minimum of 45.0 mcd (P1) to a maximum of 112.0 mcd (Q2). A tolerance of ±11% is applied within each bin. Selecting from a single bin is crucial for applications requiring uniform brightness.

3.2 Forward Voltage Binning

Forward voltage is binned into seven categories (Bin Codes 34 to 40), each spanning 0.1V, from 2.70-2.80V (Code 34) to 3.30-3.40V (Code 40). The ±0.05V tolerance per bin ensures predictable current draw when LEDs are driven in parallel with a common current-limiting resistor.

3.3 Chromaticity Coordinate Binning

The Pure White light is defined by chromaticity coordinates on the CIE 1931 diagram. The datasheet specifies four bins (1-4), each defined by a quadrilateral of (x, y) coordinate pairs. The tolerance for these coordinates is ±0.01. This binning ensures color consistency, which is vital for backlighting and indicator applications where color matching is important.

4. Mechanical and Package Information

4.1 Package Dimensions

The LED conforms to a standard SMD package with dimensions of approximately 2.0mm in length, 1.25mm in width, and 0.8mm in height (tolerance ±0.1mm unless otherwise noted). The package drawing clearly indicates the cathode mark, which is essential for correct PCB orientation. The recommended land pattern (footprint) is provided to ensure proper soldering and mechanical stability.

4.2 Polarity Identification

Correct polarity is critical. The package features a distinct cathode mark. The datasheet includes a detailed diagram showing this identification. Installing the LED in reverse polarity will prevent it from illuminating and applying the absolute maximum reverse voltage of 5V could damage the device.

5. Soldering and Assembly Guidelines

Adherence to these guidelines is mandatory to prevent thermal or mechanical damage during the assembly process.

5.1 Reflow Soldering Profile

The component is compatible with lead-free (Pb-free) reflow soldering processes. The specified temperature profile is critical:

• Pre-heating: 150-200°C for 60-120 seconds.
• Time Above Liquidus (217°C): 60-150 seconds.
• Peak Temperature: 260°C maximum, held for no more than 10 seconds.
• Heating Rate: Maximum 6°C/second.
• Time Above 255°C: Maximum 30 seconds.
• Cooling Rate: Maximum 3°C/second.

Reflow soldering should not be performed more than two times on the same component.

5.2 Hand Soldering

If hand soldering is necessary, extreme care must be taken. The soldering iron tip temperature must be below 350°C, and contact time per terminal must not exceed 3 seconds. A low-capacity iron (≤25W) is recommended. A minimum interval of 2 seconds should be observed between soldering each terminal to allow for cooling.

5.3 Storage and Moisture Sensitivity

The LEDs are packaged in moisture-resistant barrier bags with desiccant.

• Before Opening: Store at ≤30°C and ≤90% Relative Humidity (RH).
• After Opening (Floor Life): 168 hours (7 days) at ≤30°C and ≤60% RH.
• Baking: If the floor life is exceeded or the desiccant indicates moisture ingress, bake at 60 ±5°C for 24 hours before use.

Do not open the moisture-proof bag until the components are ready for assembly.

6. Packaging and Ordering Information

6.1 Standard Packaging

The LEDs are supplied in 8mm carrier tape on 7-inch diameter reels. Each reel contains 2000 pieces. The carrier tape and reel dimensions are specified in the datasheet to facilitate automated handling and setup of pick-and-place machines.

6.2 Label Explanation

The reel label contains critical information for traceability and verification:

• CPN: Customer's Product Number.
• P/N: Manufacturer's Product Number (e.g., 12-21C/T3D-CP1Q2B12Y/2C).
• QTY: Packing Quantity.
• CAT: Luminous Intensity Rank (Bin Code: P1, P2, Q1, Q2).
• HUE: Chromaticity Coordinates & Dominant Wavelength Rank (Bin Code: 1, 2, 3, 4).
• REF: Forward Voltage Rank (Bin Code: 34 to 40).
• LOT No: Manufacturing Lot Number for traceability.

7. Application Design Considerations

7.1 Current Limiting is Mandatory

LEDs are current-driven devices. An external current-limiting resistor is absolutely required. The forward voltage has a negative temperature coefficient and a manufacturing spread (as seen in the binning). A slight increase in supply voltage or a decrease in V_F due to temperature can cause a large, potentially destructive increase in forward current if no series resistor is used. The resistor value (R) can be calculated using Ohm's Law: R = (V_supply - V_F) / I_F, where I_F is the desired operating current (e.g., 5mA).

7.2 Thermal Management

While the power dissipation is low (40mW max), proper thermal design on the PCB is still important for longevity, especially in high ambient temperature applications. Ensure the PCB copper pad connected to the LED's thermal path (often the cathode) is sufficiently sized to act as a heat sink and is connected to larger copper planes if possible.

7.3 ESD Protection

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With an ESD rating of 150V (HBM), these devices are sensitive. Implement ESD control measures throughout handling, storage, and assembly. This includes the use of grounded workstations, wrist straps, and conductive containers.

8. Technical Comparison and Differentiation

Compared to larger, through-hole LEDs, the 12-21C offers a drastic reduction in size and weight, enabling modern miniaturized designs. Its wide 110-degree viewing angle, provided by the diffused yellow resin, offers more uniform light emission compared to clear resin packages with narrower beams, making it superior for area illumination and backlighting. The comprehensive binning system for intensity, voltage, and color provides a level of consistency that is essential for professional applications where visual uniformity is paramount, setting it apart from non-binned or loosely binned commodity LEDs.

9. Frequently Asked Questions (FAQ)

9.1 Can I drive this LED without a current-limiting resistor?

No. This is explicitly warned against in the "Precautions For Use" section. The LED is highly sensitive to voltage changes. Operating it directly from a voltage source, even a regulated one, is very likely to cause immediate failure due to overcurrent.

9.2 What is the difference between the P1, Q2, etc., bins?

These are luminous intensity bins. P1 represents the lowest brightness group (45.0-57.0 mcd), and Q2 represents the highest (90.0-112.0 mcd) when tested at 5mA. For consistent appearance in an array, all LEDs should be from the same intensity bin.

9.3 How many times can I reflow solder this component?

The datasheet specifies that reflow soldering should not be done more than two times. Each reflow cycle subjects the component to thermal stress, and exceeding two cycles may compromise the internal wire bonds or the epoxy resin.

9.4 The bag has been open for a week. Can I still use the LEDs?

Possibly, but they require baking first. The floor life after opening is 168 hours (7 days) under specified conditions. If this time is exceeded, you must perform the baking procedure (60 ±5°C for 24 hours) to drive out absorbed moisture and prevent "popcorning" or delamination during subsequent soldering.

10. Practical Design and Usage Case

Scenario: Designing a backlit membrane switch panel. A designer needs 20 white LEDs for even backlighting of icons. They would:

1. Select Bin: Choose all LEDs from the same Luminous Intensity bin (e.g., Q1) and Chromaticity bin (e.g., 2) to ensure uniform brightness and color.
2. Calculate Resistor: Using a 5V supply and a nominal V_F of 3.0V (from Bin 36), target I_F = 5mA. R = (5V - 3.0V) / 0.005A = 400Ω. A standard 390Ω or 430Ω resistor would be suitable.
3. PCB Layout: Use the recommended land pattern from the datasheet. Connect the cathode pad to a slightly larger copper pour for minor heat sinking.
4. Assembly: Keep components in sealed bag until ready. Use the specified lead-free reflow profile. Avoid hand soldering if possible.
5. Testing: Verify forward voltage and light output of a sample from the batch to confirm it aligns with the selected bin.

This process ensures a reliable, professional-grade result.

11. Operational Principle

The 12-21C LED is based on an InGaN (Indium Gallium Nitride) semiconductor chip. When a forward voltage exceeding the diode's junction potential (V_F) is applied, electrons and holes are injected into the active region of the semiconductor. Their recombination releases energy in the form of photons, a process called electroluminescence. The specific composition of the InGaN layers determines the wavelength of the emitted light, producing the "Pure White" spectrum specified. The yellow diffused resin encapsulant serves to protect the chip, shape the light output into a wide viewing angle, and may contain phosphors (though not explicitly stated for this "Pure White" type, it is common for white LEDs to use a blue chip with a yellow phosphor).

12. Industry Trends and Context

The 12-21C exemplifies key trends in LED technology: relentless miniaturization, increased efficiency (higher luminous intensity from a small package), and enhanced manufacturability via SMD packaging and tape-and-reel supply. The focus on environmental compliance (RoHS, Halogen-Free) reflects broader industry and regulatory demands. The detailed binning system highlights the market's need for predictable, consistent performance in mass-produced electronics. Future evolution in this product category would likely focus on further increasing luminous efficacy (more light per mA), improving color rendering index (CRI) for white LEDs, and perhaps integrating driver circuitry or multiple dice into similarly sized packages for smarter, more functional lighting solutions.