Red LED 0402 Specification - 1.0x0.5x0.4mm - Forward Voltage 1.6-2.4V - Power 48mW - Technical Datasheet

1. Product Overview

1.1 General Description

This LED is a surface-mount red light emitting diode fabricated using a red chip. The package dimensions are 1.0 mm x 0.5 mm x 0.4 mm, making it suitable for compact designs. It offers a wide viewing angle and is compatible with standard SMT assembly processes. The device is designed for general purpose indicator and display applications.

1.2 Features

• Extremely wide viewing angle of 140 degrees.
• Suitable for all SMT assembly and solder processes.
• Moisture sensitivity level: Level 3 (per JEDEC).
• RoHS compliant and free of hazardous substances.

1.3 Applications

• Optical indicators in consumer electronics.
• Switch and symbol backlighting.
• General electronic signage and display modules.

2. Technical Parameters

2.1 Electrical and Optical Characteristics (at Ts=25°C, IF=5mA)

The following are the key electrical and optical parameters measured at a forward current of 5 mA and ambient temperature of 25°C:

• Spectral Half Bandwidth: 15 nm (typical). This indicates the width of the emission spectrum at half maximum intensity.
• Forward Voltage (VF): Binned into 8 ranges from 1.6 V to 2.4 V, with increments of 0.1 V. Bins include A1 (1.6-1.7V), A2 (1.7-1.8V), B1 (1.8-1.9V), B2 (1.9-2.0V), C1 (2.0-2.1V), C2 (2.1-2.2V), D1 (2.2-2.3V), D2 (2.3-2.4V).
• Dominant Wavelength (λD): Available in three bins: F00 (625–630 nm), G00 (630–635 nm), H00 (635–640 nm).
• Luminous Intensity (IV): Sorted into six bins: A00 (8–12 mcd), B00 (12–18 mcd), C00 (18–28 mcd), D00 (28–43 mcd), E00 (43–65 mcd), F00 (65–100 mcd).
• Viewing Angle (2θ1/2): 140 degrees (typical), providing a wide radiation pattern.
• Reverse Current (IR): Maximum 10 μA at reverse voltage VR=5V.
• Thermal Resistance (RTHJ-S): Maximum 450 °C/W, indicating the junction-to-solder point thermal resistance.

2.2 Absolute Maximum Ratings

To prevent damage, the LED must not be operated beyond the following limits:

• Power Dissipation (Pd): 48 mW.
• Forward Current (IF): 20 mA continuous.
• Peak Forward Current (IFP): 60 mA (pulse width 0.1 ms, duty cycle 1/10).
• Electrostatic Discharge (ESD, HBM): 2000 V.
• Operating Temperature (Topr): -40 to +85 °C.
• Storage Temperature (Tstg): -40 to +85 °C.
• Junction Temperature (Tj): 95 °C.

3. Binning System

3.1 Voltage Binning

The forward voltage is tightly controlled through binning to ensure consistent performance in series and parallel circuits. There are eight voltage bins ranging from 1.6 V to 2.4 V, each covering a 0.1 V window. The bin codes are A1, A2, B1, B2, C1, C2, D1, and D2.

3.2 Wavelength Binning

Dominant wavelength is binned into three groups to meet specific color requirements: F00 (625–630 nm, deep red), G00 (630–635 nm, standard red), and H00 (635–640 nm, slightly longer red).

3.3 Luminous Intensity Binning

Luminous intensity is divided into six bins to provide flexibility in brightness selection. The bins range from A00 (lowest) to F00 (highest), with values from 8 mcd to 100 mcd.

4. Performance Curves

4.1 Forward Voltage vs Forward Current

The curve shows a logarithmic relationship: as forward current increases, forward voltage also increases gradually. At 5 mA, the typical voltage is around 1.8–2.0 V depending on the bin.

4.2 Forward Current vs Relative Intensity

Relative light output increases with forward current. The curve is nearly linear up to 20 mA, indicating good efficiency at typical drive currents.

4.3 Pin Temperature vs Relative Intensity

As the pin temperature rises, the relative intensity decreases. At 85°C, the intensity may drop to approximately 80–90% of the value at 25°C, depending on current.

4.4 Pin Temperature vs Forward Current

Higher temperatures require derating of forward current to avoid exceeding maximum junction temperature.

4.5 Forward Current vs Dominant Wavelength

Increasing forward current causes a slight shift in dominant wavelength, typically a few nanometers towards longer wavelengths.

4.6 Relative Intensity vs Wavelength

The emission spectrum has a peak around 625–640 nm with a half-width of 15 nm, providing a narrow red color.

4.7 Radiation Pattern

The radiation diagram shows a wide angle of 140 degrees, making the LED suitable for broad area illumination in indicator applications.

5. Mechanical and Package Information

5.1 Package Dimensions

The LED package measures 1.0 mm × 0.5 mm × 0.4 mm (length × width × height). The top view shows two electrodes: anode and cathode. The bottom view reveals solder pads of different sizes for easy identification. The polarity is marked with a notch or a dot on the top surface.

5.2 Polarity and Soldering Patterns

The recommended soldering pattern consists of two pads: one for the anode (larger) and one for the cathode (smaller). Proper alignment ensures correct polarity. The layout dimensions are provided in the datasheet: 0.6 mm for each pad with a spacing of 0.5 mm.

5.3 Tape and Reel Dimensions

Carrier tape uses 8 mm width, with a pitch of 2.00 mm for component pockets. The reel diameter is 178 mm, with a width of 8.0 mm. Each reel contains 4000 pieces.

6. Soldering and Assembly Guidelines

6.1 SMT Reflow Soldering

The recommended reflow profile involves a ramp-up rate of up to 3°C/s, preheating from 150°C to 200°C for 60–120 seconds, followed by a ramp to a peak temperature of 260°C (max) for a duration of 10 seconds. Cool down at a rate of up to 6°C/s. Total time from 25°C to peak should not exceed 8 minutes.

6.2 Hand Soldering

If hand soldering is necessary, use a soldering iron with a temperature below 300°C and complete the joint in less than 3 seconds. Only one hand soldering operation is allowed per LED.

6.3 Repair and Rework

Repair after soldering is not recommended. If unavoidable, use a double-head soldering iron and verify that the LED characteristics are not compromised. Avoid mechanical stress during cooling.

6.4 General Cautions

Do not mount LEDs on warped PCB areas. After soldering, do not warp the board or apply vibration. Rapid cooling after reflow is not permitted.

7. Packaging and Ordering Information

7.1 Carrier Tape and Reel

Standard packaging is 4000 pieces per reel in 8 mm carrier tape. The tape has feed holes and a top cover tape. The reel is labeled with part number, lot number, bin codes, quantity, and date.

7.2 Moisture Resistant Packing

The LEDs are shipped in moisture barrier bags with desiccant to maintain low moisture levels. MSL Level 3 requires that after opening, the devices must be used within 168 hours if stored at ≤30°C/60%RH. Baking at 60°C for 24 hours is required if the time limit is exceeded.

7.3 Reliability Test Summary

The product has passed standard reliability tests including reflow soldering (260°C, 10s, 2 cycles), temperature cycling (−40°C to 100°C, 100 cycles), thermal shock (−40°C/100°C, 300 cycles), high temperature storage (100°C, 1000h), low temperature storage (−40°C, 1000h), and life test (25°C, 5mA, 1000h). Criteria for failure are defined as VF shift >10%, IR >2x limit, or intensity drop >30%.

8. Application Recommendations

8.1 Typical Application Circuits

For indicator applications, a series current-limiting resistor should be used. For example, at 5V supply and 5mA current, a resistor around 640Ω (for VF≈1.8V) is appropriate. For higher brightness, drive up to 20mA with proper thermal management.

8.2 ESD Protection

The LED has an ESD withstand voltage of 2000V (HBM). However, standard ESD precautions (grounding, wrist straps, ionizers) are recommended during handling and assembly.

8.3 Thermal Design

Although the thermal resistance is relatively high (450°C/W), the low power dissipation means heat is manageable. Ensure good solder joint contact and avoid placing the LED near high-power heat sources.

9. Technical Comparison

9.1 Comparison with Standard 0402 Red LEDs

This LED offers a wider viewing angle (140°) compared to typical 120° devices. The tight binning options allow better color and brightness consistency. The ESD rating of 2 kV is higher than many standard LEDs (typically 1 kV). The thermal resistance is comparable to similar packages.

10. Common Questions

10.1 What is the recommended forward current?

The typical test current is 5 mA, but the LED can be driven up to 20 mA continuously. For pulsing, up to 60 mA at 10% duty cycle.

10.2 How should I store the LEDs after opening the bag?

Store at ≤30°C and ≤60% RH. Use within 168 hours. If not used, bake at 60°C for 24 hours before use.

10.3 Can I use these LEDs in outdoor applications?

The operating temperature range is -40 to +85°C, suitable for many outdoor applications if properly protected from moisture and mechanical stress.

11. Practical Application Examples

11.1 Status Indicator on a Smartphone Case

A 0402 red LED is used to indicate charging status. With a 5 mA drive, it provides sufficient visibility. The wide viewing angle ensures the indicator is seen from various angles.

11.2 Backlit Pushbutton in Automotive Console

Multiple 0402 LEDs are placed behind a symbol to provide uniform red backlighting. The compact size allows for dense packing.

12. Operating Principle

12.1 Red LED Working Principle

The LED is based on a semiconductor junction made from a red-emitting material (typically AlGaInP or GaAsP). When a forward bias is applied, electrons and holes recombine in the active region, emitting photons with energy corresponding to the red wavelength range (625–640 nm). The intensity is proportional to the current. The chip is encapsulated in a transparent epoxy or silicone package that directs light outward.

13. Development Trends

13.1 Miniaturization and Higher Efficiency

The trend in LED packaging is toward smaller footprints like 0402 and even 0201, without sacrificing brightness or reliability. Advances in chip design and phosphor technology (for white LEDs) continue to push efficacy higher. For red LEDs, improved AlGaInP structures have led to higher luminous efficacy and better temperature stability. Future developments may include integrated ESD protection and higher power capabilities in small packages.