Table of Contents
- 1. Product Overview
- 1.1 General Description
- 1.2 Features
- 1.3 Applications
- 2. Technical Parameters
- 2.1 Package Dimensions
- 2.2 Electrical / Optical Characteristics (Ts=25°C, IF=20mA)
- 2.3 Absolute Maximum Ratings
- 3. Sorting System
- 4. Performance Curves Analysis
- 5. Mechanical and Packaging Information
- 5.1 Carrier Tape and Reel Dimensions
- 5.2 Label Specification
- 5.3 Moisture Resistant Packing
- 6. Welding and Assembly Guide
- 6.1 SMT Reflow Soldering
- 6.2 Hand Soldering and Repair
- 7. Packaging and Ordering Information
- 8. Application Considerations
- 8.1 Typical Applications
- 8.2 Design Precautions
- 9. Reliability and Testing
- 9.1 Reliability Test Items
- 9.2 Failure Criteria
- 10. Handling and Storage Precautions
- 11. Frequently Asked Questions
- 12. Working Principle
- 13. Development Trends
- 14. Case Study
- LED Specification Terminology
- Photoelectric Performance
- Electrical Parameters
- Thermal Management & Reliability
- Packaging & Materials
- Quality Control & Binning
- Testing & Certification
1. Product Overview
1.1 General Description
This yellow LED is fabricated using a yellow chip and packaged in a compact 1608 surface-mount package with dimensions 1.6mm × 0.8mm × 0.7mm. It is designed for general purpose optical indication and display applications, offering a wide viewing angle and compatibility with standard SMT assembly processes.
1.2 Features
- Extremely wide viewing angle of 140°.
- Suitable for all SMT assembly and soldering processes.
- Moisture sensitivity level: Level 3 (MSL 3).
- RoHS compliant.
1.3 Applications
- Optical indicators
- Switches, symbols, and displays
- General use
2. Technical Parameters
2.1 Package Dimensions
The LED package measures 1.6mm in length, 0.8mm in width, and 0.7mm in height. The top and bottom views show two terminals with polarity marking. The recommended soldering pattern suggests a pad layout with two 0.8mm pads separated by 2.4mm center-to-center distance, allowing for reliable solder joint formation.
2.2 Electrical / Optical Characteristics (Ts=25°C, IF=20mA)
| Parameter | Symbol | Min | Typ | Max | Unit |
|---|---|---|---|---|---|
| Spectral Half Bandwidth | Δλ | -- | 15 | -- | nm |
| Forward Voltage (B0) | VF | 1.8 | -- | 2.0 | V |
| Forward Voltage (C0) | VF | 2.0 | -- | 2.2 | V |
| Forward Voltage (D0) | VF | 2.2 | -- | 2.4 | V |
| Dominant Wavelength (2K) | λD | 585 | -- | 590 | nm |
| Dominant Wavelength (2L) | λD | 590 | -- | 595 | nm |
| Luminous Intensity (F20) | IV | 80 | -- | 100 | mcd |
| Luminous Intensity (G10) | IV | 100 | -- | 120 | mcd |
| Luminous Intensity (G20) | IV | 120 | -- | 150 | mcd |
| Luminous Intensity (H10) | IV | 150 | -- | 180 | mcd |
| Luminous Intensity (H20) | IV | 180 | -- | 230 | mcd |
| Viewing Angle | 2θ1/2 | -- | 140 | -- | deg |
| Reverse Current (VR=5V) | IR | -- | -- | 10 | μA |
| Thermal Resistance | RTHJ-S | -- | -- | 450 | °C/W |
2.3 Absolute Maximum Ratings
| Parameter | Symbol | Rating | Unit |
|---|---|---|---|
| Power Dissipation | Pd | 72 | mW |
| Forward Current | IF | 30 | mA |
| Peak Forward Current (1/10 Duty, 0.1ms) | IFP | 60 | mA |
| Electrostatic Discharge (HBM) | ESD | 2000 | V |
| Operating Temperature | Topr | -40 ~ +85 | °C |
| Storage Temperature | Tstg | -40 ~ +85 | °C |
| Junction Temperature | Tj | 95 | °C |
3. Sorting System
The LED is sorted into different bins based on forward voltage, dominant wavelength, and luminous intensity to ensure consistent performance in applications.
- Forward Voltage (VF): Three bins – B0 (1.8-2.0V), C0 (2.0-2.2V), D0 (2.2-2.4V).
- Dominant Wavelength (λD): Two bins – 2K (585-590nm), 2L (590-595nm).
- Luminous Intensity (IV): Five bins – F20 (80-100mcd), G10 (100-120mcd), G20 (120-150mcd), H10 (150-180mcd), H20 (180-230mcd).
4. Performance Curves Analysis
The typical optical characteristics curves provide insight into the device behavior under various operating conditions.
- Forward Voltage vs. Forward Current (Fig 1-6): Shows exponential increase of current with voltage, typical for an LED diode. At 20mA, the forward voltage falls within the sorted bins.
- Forward Current vs. Relative Intensity (Fig 1-7): Relative luminous intensity increases almost linearly with current up to the rated maximum, indicating good efficiency at lower currents.
- Pin Temperature vs. Relative Intensity (Fig 1-8): Higher pin temperature reduces light output; approximately 20% drop at 85°C compared to 25°C, highlighting the need for thermal management.
- Pin Temperature vs. Forward Current (Fig 1-9): Forward current decreases as temperature rises if constant voltage is applied, emphasizing the importance of current regulation.
- Forward Current vs. Dominant Wavelength (Fig 1-10): Dominant wavelength shifts slightly towards longer wavelengths (red shift) with increasing current, typical for yellow LEDs.
- Relative Intensity vs. Wavelength (Fig 1-11): Spectral distribution peaks around the dominant wavelength with a half bandwidth of 15nm, ensuring saturated yellow color.
- Radiation Pattern (Fig 1-12): The LED emits light over a wide angle of 140°, with uniform intensity distribution, suitable for indicator and backlighting applications.
5. Mechanical and Packaging Information
5.1 Carrier Tape and Reel Dimensions
The LED is packaged in carrier tape of width 8.0mm, with pocket pitch 4.0mm and internal pocket dimensions 1.8mm x 0.92mm. The reel diameter is 178mm ±1mm, with a hub diameter of 60mm ±1mm. Each reel contains 4000 pieces.
5.2 Label Specification
The label includes Part Number, Spec Number, Lot Number, Bin Code (including luminous flux bin, chromaticity bin, forward voltage bin, wavelength code), quantity, and date of manufacture.
5.3 Moisture Resistant Packing
Reels are sealed in a moisture barrier bag together with a desiccant and humidity indicator card. The moisture sensitivity level is MSL 3, requiring storage conditions below 30°C and 60% RH after opening, with a floor life of 168 hours.
6. Welding and Assembly Guide
6.1 SMT Reflow Soldering
| Parameter | Value |
|---|---|
| Average ramp-up rate (Tsmax to Tp) | Max 3°C/s |
| Preheat temperature (Tsmin to Tsmax) | 150°C to 200°C |
| Preheat time | 60 to 120 seconds |
| Time above 217°C (tL) | Max 60 seconds |
| Peak temperature (Tp) | 260°C |
| Time within 5°C of peak (tp) | Max 10 seconds |
| Cooling rate | Max 6°C/s |
| Time from 25°C to Tp | Max 8 minutes |
Reflow soldering should not exceed two times. If an interval of more than 24 hours occurs between two soldering processes, the LEDs may absorb moisture and be damaged. Do not apply mechanical stress during heating.
6.2 Hand Soldering and Repair
Hand soldering is allowed only once, with iron temperature below 300°C and duration less than 3 seconds. Repairing after soldering is discouraged; if unavoidable, use a double-head soldering iron and verify LED integrity.
7. Packaging and Ordering Information
The standard packaging unit is 4000 pieces per reel. The carrier tape is 8mm wide and conforms to EIA-481 standard. Reels are packed in moisture barrier bags and then placed into cardboard boxes for shipment. The box dimensions support safe transport of multiple reels.
8. Application Considerations
8.1 Typical Applications
Typical uses include optical indicators on electronic devices, switch backlighting, symbol illumination, and general display functions where a bright yellow indicator is needed.
8.2 Design Precautions
- Always use a current-limiting resistor in series with the LED to prevent current runaway from voltage variations.
- Thermal design is critical: ensure adequate heat sinking to keep junction temperature below 95°C.
- Environment sulfur content must be below 100PPM; halogen content (bromine and chlorine) individually below 900PPM and total below 1500PPM.
- Avoid exposure to volatile organic compounds (VOCs) that may outgas from adhesives or encapsulants, as they can discolor the silicone.
- Provide ESD protection during handling and assembly; typical HBM rating is 2000V.
9. Reliability and Testing
9.1 Reliability Test Items
| Test Item | Condition | Duration/Count | Accept/Reject |
|---|---|---|---|
| Reflow Soldering | 260°C, 10 sec | 2 times | 0/1 |
| Temperature Cycle | -40°C to 100°C, 30 min each | 100 cycles | 0/1 |
| Thermal Shock | -40°C to 100°C, 15 min | 300 cycles | 0/1 |
| High Temperature Storage | 100°C | 1000 hrs | 0/1 |
| Low Temperature Storage | -40°C | 1000 hrs | 0/1 |
| Life Test (IF=20mA, Ta=25°C) | 25°C, 20mA | 1000 hrs | 0/1 |
9.2 Failure Criteria
After reliability tests, the LED is considered failed if: Forward voltage (at IF=20mA) exceeds U.S.L × 1.1; Reverse current (at VR=5V) exceeds U.S.L × 2.0; Luminous flux is below L.S.L × 0.7.
10. Handling and Storage Precautions
- Store unopened bags at ≤30°C and ≤75% RH for up to one year from date of manufacture.
- After opening, the floor life is 168 hours at ≤30°C and ≤60% RH.
- If the moisture barrier bag is damaged or the humidity indicator shows excessive moisture, bake the LEDs at 60±5°C for at least 24 hours before use.
- Handle with ESD precaution: use grounded workstations, wrist straps, and conductive packaging.
- Do not bend or twist the PCB after soldering; avoid rapid cooling.
- Do not use adhesives that outgas organic vapor in the vicinity of the LED.
11. Frequently Asked Questions
Q: Why is a current-limiting resistor necessary?
A: The forward voltage of an LED varies with temperature and from unit to unit. A small change in voltage can cause a large change in current, potentially exceeding the maximum rating. A series resistor stabilizes the current.
Q: Can these LEDs be driven in parallel?
A: Paralleling LEDs without individual current limiting can cause current imbalance due to VF variations. It is recommended to use separate resistors or constant current drivers for each string.
Q: What is the typical lifetime of this LED?
A: Under standard operating conditions (20mA, 25°C), the LED is expected to operate for more than 50,000 hours, though the exact lifetime depends on thermal management and drive conditions.
12. Working Principle
This yellow LED is based on a semiconductor diode made from a yellow-emitting chip (typically Gallium Phosphide or a related compound). When forward biased, electrons and holes recombine in the active region, releasing energy in the form of photons. The wavelength of emitted light (around 585-595nm) corresponds to the bandgap energy of the material, producing a yellow color. The wide viewing angle is achieved through the package design and the use of a diffusing encapsulant.
13. Development Trends
Continuing trends in LED technology include further miniaturization of packages, higher luminous efficacy, improved color stability, and stricter environmental compliance. The 1608 package is already a compact form factor; future developments may include even smaller packages (e.g., 1006) with similar or higher performance. Advances in phosphor and chip materials may also extend the range of available colors and improve thermal performance.
14. Case Study
Application: Status Indicator on a Smart Home Device
A smart thermostat uses a yellow LED (similar to this product) to indicate Wi-Fi communication status. The LED is driven at 10mA to provide comfortable brightness without glare. A 180Ω series resistor is used with a 3.3V supply. The wide viewing angle ensures the indicator is visible from any direction. The device passes reliability tests including temperature cycling and high humidity storage, confirming robustness. The MSL 3 handling ensures no moisture-related defects during assembly.
LED Specification Terminology
Complete explanation of LED technical terms
Photoelectric Performance
| Term | Unit/Representation | Simple Explanation | Why Important |
|---|---|---|---|
| Luminous Efficacy | lm/W (lumens per watt) | Light output per watt of electricity, higher means more energy efficient. | Directly determines energy efficiency grade and electricity cost. |
| Luminous Flux | lm (lumens) | Total light emitted by source, commonly called "brightness". | Determines if the light is bright enough. |
| Viewing Angle | ° (degrees), e.g., 120° | Angle where light intensity drops to half, determines beam width. | Affects illumination range and uniformity. |
| CCT (Color Temperature) | K (Kelvin), e.g., 2700K/6500K | Warmth/coolness of light, lower values yellowish/warm, higher whitish/cool. | Determines lighting atmosphere and suitable scenarios. |
| CRI / Ra | Unitless, 0–100 | Ability to render object colors accurately, Ra≥80 is good. | Affects color authenticity, used in high-demand places like malls, museums. |
| SDCM | MacAdam ellipse steps, e.g., "5-step" | Color consistency metric, smaller steps mean more consistent color. | Ensures uniform color across same batch of LEDs. |
| Dominant Wavelength | nm (nanometers), e.g., 620nm (red) | Wavelength corresponding to color of colored LEDs. | Determines hue of red, yellow, green monochrome LEDs. |
| Spectral Distribution | Wavelength vs intensity curve | Shows intensity distribution across wavelengths. | Affects color rendering and quality. |
Electrical Parameters
| Term | Symbol | Simple Explanation | Design Considerations |
|---|---|---|---|
| Forward Voltage | Vf | Minimum voltage to turn on LED, like "starting threshold". | Driver voltage must be ≥Vf, voltages add up for series LEDs. |
| Forward Current | If | Current value for normal LED operation. | Usually constant current drive, current determines brightness & lifespan. |
| Max Pulse Current | Ifp | Peak current tolerable for short periods, used for dimming or flashing. | Pulse width & duty cycle must be strictly controlled to avoid damage. |
| Reverse Voltage | Vr | Max reverse voltage LED can withstand, beyond may cause breakdown. | Circuit must prevent reverse connection or voltage spikes. |
| Thermal Resistance | Rth (°C/W) | Resistance to heat transfer from chip to solder, lower is better. | High thermal resistance requires stronger heat dissipation. |
| ESD Immunity | V (HBM), e.g., 1000V | Ability to withstand electrostatic discharge, higher means less vulnerable. | Anti-static measures needed in production, especially for sensitive LEDs. |
Thermal Management & Reliability
| Term | Key Metric | Simple Explanation | Impact |
|---|---|---|---|
| Junction Temperature | Tj (°C) | Actual operating temperature inside LED chip. | Every 10°C reduction may double lifespan; too high causes light decay, color shift. |
| Lumen Depreciation | L70 / L80 (hours) | Time for brightness to drop to 70% or 80% of initial. | Directly defines LED "service life". |
| Lumen Maintenance | % (e.g., 70%) | Percentage of brightness retained after time. | Indicates brightness retention over long-term use. |
| Color Shift | Δu′v′ or MacAdam ellipse | Degree of color change during use. | Affects color consistency in lighting scenes. |
| Thermal Aging | Material degradation | Deterioration due to long-term high temperature. | May cause brightness drop, color change, or open-circuit failure. |
Packaging & Materials
| Term | Common Types | Simple Explanation | Features & Applications |
|---|---|---|---|
| Package Type | EMC, PPA, Ceramic | Housing material protecting chip, providing optical/thermal interface. | EMC: good heat resistance, low cost; Ceramic: better heat dissipation, longer life. |
| Chip Structure | Front, Flip Chip | Chip electrode arrangement. | Flip chip: better heat dissipation, higher efficacy, for high-power. |
| Phosphor Coating | YAG, Silicate, Nitride | Covers blue chip, converts some to yellow/red, mixes to white. | Different phosphors affect efficacy, CCT, and CRI. |
| Lens/Optics | Flat, Microlens, TIR | Optical structure on surface controlling light distribution. | Determines viewing angle and light distribution curve. |
Quality Control & Binning
| Term | Binning Content | Simple Explanation | Purpose |
|---|---|---|---|
| Luminous Flux Bin | Code e.g., 2G, 2H | Grouped by brightness, each group has min/max lumen values. | Ensures uniform brightness in same batch. |
| Voltage Bin | Code e.g., 6W, 6X | Grouped by forward voltage range. | Facilitates driver matching, improves system efficiency. |
| Color Bin | 5-step MacAdam ellipse | Grouped by color coordinates, ensuring tight range. | Guarantees color consistency, avoids uneven color within fixture. |
| CCT Bin | 2700K, 3000K etc. | Grouped by CCT, each has corresponding coordinate range. | Meets different scene CCT requirements. |
Testing & Certification
| Term | Standard/Test | Simple Explanation | Significance |
|---|---|---|---|
| LM-80 | Lumen maintenance test | Long-term lighting at constant temperature, recording brightness decay. | Used to estimate LED life (with TM-21). |
| TM-21 | Life estimation standard | Estimates life under actual conditions based on LM-80 data. | Provides scientific life prediction. |
| IESNA | Illuminating Engineering Society | Covers optical, electrical, thermal test methods. | Industry-recognized test basis. |
| RoHS / REACH | Environmental certification | Ensures no harmful substances (lead, mercury). | Market access requirement internationally. |
| ENERGY STAR / DLC | Energy efficiency certification | Energy efficiency and performance certification for lighting. | Used in government procurement, subsidy programs, enhances competitiveness. |