IR LED 0402 SMD Datasheet - Size 1.0x0.5x0.5mm - Forward Voltage 1.5V - Peak Wavelength 940nm - English Technical Document

1. Product Overview

This document details the specifications for a high-reliability, miniature surface-mount infrared emitting diode. The device is housed in a compact 0402 package, molded in water-clear epoxy, and is spectrally matched with silicon photodiodes and phototransistors, making it ideal for sensing applications.

1.1 Core Advantages

• High Reliability: Designed for consistent performance in demanding applications.
• Miniature Footprint: The double-ended 0402 package allows for high-density PCB mounting.
• Process Compatibility: Suitable for both infrared and vapor phase reflow soldering processes.
• Environmental Compliance: The product is Pb-free, RoHS compliant, compliant with EU REACH, and meets halogen-free standards (Br <900 ppm, Cl <900 ppm, Br+Cl < 1500 ppm).

1.2 Target Applications

• PCB-mounted infrared sensors
• Infrared remote control units requiring high power output
• Optical scanners
• Various infrared application systems

2. Technical Parameter Deep Dive

2.1 Absolute Maximum Ratings

These ratings define the limits beyond which permanent damage to the device may occur. Operation under these conditions is not guaranteed.

Parameter	Symbol	Rating	Unit	Notes
Continuous Forward Current	IF	50	mA
Reverse Voltage	VR	5	V
Operating Temperature	Topr	-40 to +100	°C
Storage Temperature	Tstg	-40 to +100	°C
Soldering Temperature	Tsol	260	°C	Soldering time ≤ 5 seconds.
Power Dissipation (Ta=25°C)	Pd	100	mW

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

These are the typical performance parameters measured under standard test conditions (IF=20mA unless noted).

Parameter	Symbol	Min.	Typ.	Max.	Unit	Condition
Radiant Intensity	Ie	0.5	2.35	--	mW/sr	IF=20mA
Peak Wavelength	λp	--	940	--	nm	IF=20mA
Spectral Bandwidth (FWHM)	Δλ	--	45	--	nm	IF=20mA
Forward Voltage	VF	--	1.5	1.9	V	IF=20mA
Reverse Current	IR	--	--	10	μA	VR=5V
Viewing Angle (Half Angle)	2θ1/2	--	120	--	deg	IF=20mA

3. Performance Curve Analysis

The datasheet provides several characteristic curves essential for design engineers.

3.1 Forward Current vs. Forward Voltage (IV Curve)

The curve shows the exponential relationship between forward current (IF) and forward voltage (VF). At the typical operating point of 20mA, the forward voltage is approximately 1.5V. Designers must use a series current-limiting resistor to prevent exceeding the maximum forward current, as even a small increase in voltage can lead to a large, potentially destructive increase in current.

3.2 Forward Current vs. Ambient Temperature

This derating curve illustrates how the maximum allowable continuous forward current decreases as the ambient temperature increases. The device can handle its full rated current up to approximately 25°C. Beyond this, the maximum current must be reduced linearly to zero at the maximum junction temperature (implied by the 100°C operating limit). This is critical for ensuring long-term reliability in high-temperature environments.

3.3 Spectral Distribution

The spectral output graph confirms the peak emission wavelength at 940nm with a typical spectral bandwidth (Full Width at Half Maximum) of 45nm. This wavelength is near-optimal for silicon-based photodetectors, which have high sensitivity in this region, maximizing the signal-to-noise ratio in sensing applications.

3.4 Relative Radiant Intensity vs. Forward Current

This curve shows that radiant output is nearly linear with forward current in the typical operating range (up to about 40-50mA). This predictable relationship simplifies optical system design.

3.5 Relative Radiant Intensity vs. Angular Displacement

The polar plot depicts the emission pattern, characterized by a wide 120-degree half-angle. This provides a broad, diffuse infrared beam, ideal for applications requiring wide-area coverage or proximity sensing where alignment is not critical.

4. Mechanical and Package Information

4.1 Package Dimensions (0402)

The device conforms to a standard 0402 (Imperial) / 1005 (Metric) footprint. Key dimensions include a body length of approximately 1.0mm, width of 0.5mm, and height of 0.5mm. Terminal dimensions and spacing are provided for PCB land pattern design. All dimensional tolerances are typically ±0.1mm unless otherwise specified.

4.2 Polarity Identification

The package is double-ended. Polarity is typically indicated by a marking on the cathode (-) side or by an internal chip structure visible through the clear lens. The datasheet drawing should be consulted for the exact marking scheme.

5. Soldering and Assembly Guidelines

5.1 Storage and Moisture Sensitivity

The device is moisture-sensitive. Precautions must be taken to prevent popcorning or delamination during reflow:

• Store in original moisture-proof bag at ≤30°C / ≤90% RH.
• Use within one year of shipment.
• After opening the bag, store at ≤30°C / ≤60% RH and use within 168 hours (7 days).
• If the storage time is exceeded or the desiccant indicates moisture, bake at 60±5°C for a minimum of 24 hours before use.

5.2 Reflow Soldering Profile

A recommended Pb-free reflow temperature profile is provided. Key parameters include:

• Preheat and soak zone.
Maximum temperature ramp rate.
• Peak body temperature not to exceed 260°C.
• Time above liquidus (e.g., 217°C).
• Cooling rate.

Reflow soldering should not be performed more than two times.

5.3 Hand Soldering and Rework

If hand soldering is necessary:

• Use a soldering iron with a tip temperature <350°C.
• Limit iron power to 25W or less.
• Contact time per terminal should be ≤3 seconds.
• Allow a minimum 2-second interval between soldering each terminal.

Rework is strongly discouraged. If unavoidable, a dual-head soldering iron must be used to simultaneously heat both terminals and avoid mechanical stress on the package. The effect of rework on device characteristics must be verified beforehand.

6. Packaging and Ordering Information

6.1 Tape and Reel Specifications

The device is supplied on embossed carrier tape wound onto reels. A standard reel contains 3000 pieces. Detailed carrier tape dimensions (pocket size, pitch, tape width) and reel specifications are provided for automated pick-and-place machine setup.

6.2 Packing Procedure

Reels are packaged in sealed aluminum moisture barrier bags with desiccant and a humidity indicator card to maintain dry storage conditions.

6.3 Label Information

The package label includes critical information for traceability and verification:

• CPN (Customer Part Number)
• P/N (Manufacturer Part Number: IR16-213C/L510/TR8)
• QTY (Quantity)
• CAT (Binning/Rank Code)
• HUE (Peak Wavelength)
• LOT No. (Manufacturing Lot Number)
• Country of Origin

7. Application Design Considerations

7.1 Driving Circuit Design

The most critical design aspect is current limiting. An LED is a current-driven device. A series resistor (R_s) must be calculated based on the supply voltage (V_cc), the desired forward current (I_F), and the LED's forward voltage (V_F): R_s = (V_cc - V_F) / I_F. For a 5V supply and 20mA target current: R_s ≈ (5V - 1.5V) / 0.02A = 175Ω. A standard 180Ω resistor would be suitable. Always verify the actual current under worst-case V_F (min) to ensure it does not exceed maximum ratings.

7.2 Thermal Management

While the 0402 package has limited thermal mass, attention should be paid to power dissipation, especially in high-current or high-ambient-temperature applications. Ensure the PCB provides adequate copper area around the solder pads to act as a heat sink and follow the current derating guidelines with temperature.

7.3 Optical Design

The wide 120-degree viewing angle makes this LED suitable for applications requiring broad illumination. For longer-range or more directed beams, secondary optics (lenses) may be required. The water-clear lens ensures minimal absorption of the emitted infrared light.

8. Technical Comparison and Differentiation

Compared to other infrared LEDs, this 0402 device offers a key balance:

• vs. Larger Packages (e.g., 5mm): Significantly smaller footprint and lower profile, enabling miniaturization. Typically has lower total radiant power output but higher suitability for array or dense placement.
• vs. Other SMD IR LEDs (e.g., 0603): The 0402 package allows for the highest possible component density on a PCB, a critical advantage in space-constrained modern electronics like ultra-compact remote controls or sensors.
• vs. Non-Compliant Devices: Full compliance with RoHS, REACH, and halogen-free standards is a mandatory requirement for most commercial and industrial products today, simplifying the supply chain and end-product certification.

9. Frequently Asked Questions (FAQ)

9.1 What is the purpose of the 940nm wavelength?

940nm is in the near-infrared spectrum. It is invisible to the human eye but aligns well with the peak sensitivity of inexpensive silicon photodiodes and phototransistors. It also experiences less interference from ambient visible light compared to visible red LEDs, improving signal integrity in sensing applications.

9.2 Why is a current-limiting resistor absolutely necessary?

The I-V characteristic of an LED is exponential. Beyond the knee voltage, a tiny increase in voltage causes a very large increase in current. Without a series resistor to control the current, connecting the LED directly to a voltage source (even a small battery) will almost certainly drive it beyond its maximum current rating, causing instantaneous overheating and failure.

9.3 Can I use this for data transmission (like IR remote controls)?

Yes, this is a primary application. Its fast switching speed (implied by the GaAlAs material) and compatibility with high-current pulses make it suitable for modulated data transmission in remote controls, IR data association (IrDA) systems, and optical isolation.

9.4 How do I interpret the \"Radiant Intensity\" specification?

Radiant Intensity (I_e) of 2.35 mW/sr (typical) means the LED emits 2.35 milliwatts of optical power per steradian (a unit of solid angle) along its central axis. This is a measure of how \"bright\" the IR source is in its main direction. The total radiant flux (power in mW) can be estimated by multiplying intensity by the solid angle of the beam.

10. Design and Use Case Example

10.1 Simple Proximity Sensor

A common application is a reflectance-based proximity sensor. The IR LED is placed adjacent to a phototransistor on a PCB. A microcontroller drives the LED with a pulsed current (e.g., 20mA pulses). The phototransistor detects IR light reflected off an object. The strength of the detected signal correlates with the object's distance and reflectivity. The wide viewing angle of this LED ensures good coverage for detecting objects that may not be perfectly aligned.

11. Operating Principle

An Infrared Light Emitting Diode (IR LED) is a semiconductor p-n junction diode. When forward biased, electrons from the n-region recombine with holes from the p-region in the active region (GaAlAs chip). This recombination process releases energy in the form of photons (light). The specific wavelength of the emitted photons (940nm in this case) is determined by the bandgap energy of the semiconductor material used. The water-clear epoxy package encapsulates and protects the chip while allowing the infrared light to pass through with minimal loss.

12. Industry Trends

The trend in optoelectronics, as in all electronics, is toward miniaturization, higher integration, and improved efficiency. The 0402 package represents the ongoing push for smaller passive and active components. Future developments may include:

• Increased Power Density: Improving the luminous efficacy (radiant power output per electrical input) of ever-smaller chips.
• Integrated Solutions: Combining the IR emitter, driver, and detector into a single module or package to simplify design and improve performance.
• New Wavelengths: Development of emitters at other IR wavelengths (e.g., 850nm, 1050nm) for specific applications like eye-safe systems or different sensor optimizations.
• Advanced Packaging: Use of materials with better thermal conductivity to manage heat in high-power, miniature devices.