Table of Contents
- 1. Product Overview
- 1.1 Core Advantages and Target Market
- 2. Technical Parameter Deep-Dive
- 2.1 Absolute Maximum Ratings
- 2.2 Electro-Optical Characteristics
- 3. Binning System Explanation
- 3.1 Luminous Intensity Binning
- 3.2 Dominant Wavelength Binning
- 4. Performance Curve Analysis
- 5. Mechanical and Package Information
- 5.1 Package Dimensions
- 5.2 Polarity Identification
- 6. Soldering and Assembly Guidelines
- 6.1 Reflow Soldering Profile
- 6.2 Hand Soldering
- 6.3 Storage and Moisture Sensitivity
- 7. Packaging and Ordering Information
- 7.1 Tape and Reel Specifications
- 7.2 Label Information
- 8. Application Recommendations
- 8.1 Typical Application Scenarios
- 8.2 Critical Design Considerations
- 9. Technical Comparison and Differentiation
- 10. Frequently Asked Questions (FAQs)
- 11. Design and Usage Case Study
- 12. Operating Principle
- 13. Industry Trends and Context
1. Product Overview
This document details the specifications for a surface-mount device (SMD) LED identified as 17-21/Y2C-AN1P2/3T. It is a mono-color, brilliant yellow LED designed for modern electronic applications requiring compact, efficient, and reliable indicator or backlighting solutions. The product is Pb-free and compliant with major environmental and safety standards including RoHS, EU REACH, and halogen-free requirements (Br <900 ppm, Cl <900 ppm, Br+Cl < 1500 ppm).
1.1 Core Advantages and Target Market
The 17-21 SMD LED package offers significant advantages over traditional lead-frame components. Its miniature footprint (1.6mm x 0.8mm) enables higher packing density on printed circuit boards (PCBs), leading to reduced board size and ultimately smaller end-user equipment. The lightweight nature of the SMD package makes it ideal for portable and miniature applications. Primary target markets include consumer electronics, telecommunications equipment (for indicators and keypad backlighting), automotive dashboard and switch backlighting, and general-purpose indicator applications where space and weight are critical constraints.
2. Technical Parameter Deep-Dive
This section provides an objective and detailed analysis of the LED's key electrical, optical, and thermal characteristics.
2.1 Absolute Maximum Ratings
These ratings define the stress limits beyond which permanent damage to the device may occur. Operation outside these limits is not recommended.
- Reverse Voltage (VR): 5V. Exceeding this voltage in reverse bias can cause junction breakdown.
- Continuous Forward Current (IF): 25 mA. The maximum DC current for reliable operation.
- Peak Forward Current (IFP): 60 mA. This is permissible only under pulsed conditions (duty cycle 1/10 @ 1kHz).
- Power Dissipation (Pd): 60 mW. The maximum power the package can dissipate at Ta=25°C.
- Electrostatic Discharge (ESD) Human Body Model (HBM): 2000V. Hakanan yana nuna matakin matsakaici na ƙarfin ESD; hanyoyin sarrafawa da suka dace har yanzu suna da mahimmanci.
- Yanayin Zafi na Aiki (Topr): -40°C zuwa +85°C. Kewayon yanayin zafi na yanayi don aiki na yau da kullun.
- Storage Temperature (Tstg): -40°C to +90°C.
- Soldering Temperature (Tsol): Reflow: 260°C max for 10 seconds. Hand soldering: 350°C max for 3 seconds per terminal.
2.2 Electro-Optical Characteristics
Measured at a forward current (IF) of 20 mA and an ambient temperature (Ta) of 25°C, unless otherwise specified.
- Luminous Intensity (Iv): 28.5 mcd (Min), 72.0 mcd (Max). The typical value is not specified, indicating a wide binning range (see Section 3). A ±11% tolerance applies.
- Viewing Angle (2θ1/2): 140 degrees (Typical). This wide viewing angle makes the LED suitable for applications where visibility from off-axis angles is important.
- Peak Wavelength (λp): 591 nm (Typical). Wavelength din da emission spectral ya fi ƙarfi.
- Dominant Wavelength (λd): 585.5 nm (Min), 594.5 nm (Max). Wannan yana bayyana launin haske da ake gani. Ana amfani da ƙimar ±1nm.
- Spectral Bandwidth (Δλ): 15 nm (Typical). The width of the emitted spectrum at half the maximum intensity (FWHM).
- Forward Voltage (VF): 1.7V (Min), 2.0V (Typ), 2.4V (Max) at IF=20mA. This parameter is crucial for current-limiting resistor calculation in circuit design.
- Reverse Current (IR): 10 μA (Max) at VR=5V. The device is not designed for operation in reverse bias; this parameter is for leakage test purposes only.
3. Binning System Explanation
To manage manufacturing variations, LEDs are sorted into performance bins. This allows designers to select parts that meet specific brightness and color consistency requirements for their application.
3.1 Luminous Intensity Binning
Bins are defined by minimum and maximum luminous intensity values at IF=20mA.
- N1: 28.5 mcd to 36.0 mcd
- N2: 36.0 mcd to 45.0 mcd
- P1: 45.0 mcd to 57.0 mcd
- P2: 57.0 mcd mpaka 72.0 mcd
3.2 Dominant Wavelength Binning
Makundi yamefafanuliwa kwa thamani ya chini na ya juu zaidi ya wavelength kuu kwenye IF=20mA.
- D3: 585.5 nm to 588.5 nm
- D4: 588.5 nm to 591.5 nm
- D5: 591.5 nm to 594.5 nm
The combination of an intensity bin code (e.g., P1) and a wavelength bin code (e.g., D4) fully specifies the LED's key optical performance.
4. Performance Curve Analysis
While specific graphs are not detailed in the provided text, typical electro-optical characteristic curves for such an LED would include:
- I-V (Current-Voltage) Curve: Shows the exponential relationship between forward voltage and current. The curve will have a knee voltage around the typical VF of 2.0V.
- Luminous Intensity vs. Forward Current: Typically shows a near-linear increase in intensity with current up to the maximum rating, after which efficiency may drop.
- Luminous Intensity vs. Ambient Temperature: Shows the derating of light output as junction temperature increases. For AlGaInP LEDs, output generally decreases with rising temperature.
- Spectral Distribution: A plot showing the relative intensity across wavelengths, peaking at ~591 nm with a ~15 nm FWHM, confirming the brilliant yellow color.
- Forward Voltage vs. Ambient Temperature: Typically shows a negative temperature coefficient, where VF decreases slightly as temperature rises.
5. Mechanical and Package Information
5.1 Package Dimensions
The LED comes in a standard 17-21 SMD package. Key dimensions (in mm, tolerance ±0.1mm unless noted) are: Length=1.6, Width=0.8, Height=0.6. The package includes a cathode mark for polarity identification during assembly. The exact pad layout (land pattern) is provided to ensure proper solder joint formation and mechanical stability on the PCB.
5.2 Polarity Identification
Polarity ya daidai yana da mahimmanci don aiki. Kunshin yana da alamar cathode na musamman. Takardar bayanan tana ba da zane mai haske wanda ke nuna wurin wannan alamar dangane da guntu na ciki da kuma fakitin waje. Masu zane dole ne su daidaita wannan da daidaitaccen sawun ƙafa akan shimfidar PCB.
6. Soldering and Assembly Guidelines
Bin waɗannan jagororin yana da mahimmanci don amintacce kuma don hana lalacewa yayin tsarin masana'anta.
6.1 Reflow Soldering Profile
A lead-free (Pb-free) reflow profile is specified:
- Pre-heating: 150°C to 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 up to 255°C.
- Cooling Rate: Maximum 3°C/second.
6.2 Hand Soldering
If hand soldering is necessary:
- Use a soldering iron with a tip temperature < 350°C.
- Apply heat to each terminal for < 3 seconds.
- Use an iron with a power rating < 25W.
- Allow a minimum 2-second interval between soldering each terminal.
- Yi taka tsantsan sosai saboda yin amfani da wutar lantarki da hannu yana haifar da haɗarin zafi mafi girma.
6.3 Storage and Moisture Sensitivity
The product is packaged in a moisture-resistant bag with desiccant.
- Do not open the bag until ready for use.
- After opening, unused LEDs must be stored at ≤ 30°C and ≤ 60% Relative Humidity.
- "Floor life" bayan buɗewa shine sa'o'i 168 (kwanaki 7).
- Idan an wuce lokacin floor life ko kuma desiccant ya nuna ɗaukar danshi, ana buƙatar gasa a 60 ± 5°C na sa'o'i 24 kafin reflow.
7. Packaging and Ordering Information
7.1 Tape and Reel Specifications
The LEDs are supplied in 8mm carrier tape on 7-inch diameter reels. Each reel contains 3000 pieces. Detailed dimensions for the carrier tape pockets and the reel are provided to ensure compatibility with automated pick-and-place equipment.
7.2 Label Information
The reel label contains critical information for traceability and correct application:
- CPN: Customer's Product Number.
- P/N: Manufacturer's Product Number (17-21/Y2C-AN1P2/3T).
- QTY: Packing Quantity.
- CAT: Luminous Intensity Rank (e.g., N1, P2).
- HUE: Chromaticity/Dominant Wavelength Rank (e.g., D4, D5).
- REF: Forward Voltage Rank.
- LOT No: Manufacturing Lot Number for traceability.
8. Application Recommendations
8.1 Typical Application Scenarios
- Backlighting: Yana da kyau don kayan aikin dashboard, maɓalli na membrane, da hasken alama saboda faɗin kusurwar kallo da daidaitaccen launi.
- Sadarwa: Alamomin matsayi da hasken baya na maɓalli a cikin wayoyi, injunan faks, da kayan aikin sadarwa.
- Kayan Lantarki na Masu Amfani: General status indication, power-on lights, and backlighting for small LCD displays in various portable devices.
- General Purpose Indication: Any application requiring a compact, reliable, bright yellow visual signal.
8.2 Critical Design Considerations
- Current Limiting: An external series resistor is MANDATORY to limit forward current. The LED's VF has a range (1.7V-2.4V), so the resistor must be calculated for the worst-case (minimum VF) to prevent overcurrent and burnout. The formula is R = (Vsupply - VF) / IF.
- Thermal Management: Yayin da wutar lantake ba ta da ƙarfi, tabbatar da ingantacciyar hanyar zafi daga gadajen LED zuwa PCB yana da mahimmanci don kiyaye ƙarfin haske da tsawon rai, musamman a cikin yanayin yanayi mai zafi.
- ESD Protection: Ai amfani da matakan kariya na ESD na yau da kullun yayin sarrafawa da haɗawa. Ko da yake an ƙididdige shi don 2000V HBM, ana iya buƙatar ƙarin kariyar da'ira a cikin yanayi mai hankali.
- Optical Design: Consider the 140-degree viewing angle when designing light guides, lenses, or diffusers to achieve the desired illumination pattern.
9. Technical Comparison and Differentiation
Compared to older through-hole LED technologies, this SMD LED offers:
- Size Reduction: Drastically smaller footprint and profile, enabling miniaturization.
- Automation Compatibility: Designed for high-speed, automated pick-and-place and reflow soldering, reducing assembly costs.
- Improved Reliability: SMD construction often offers better resistance to vibration and thermal cycling.
- Wider Viewing Angle: The 140-degree viewing angle is typically superior to many traditional LEDs with narrower beams.
10. Frequently Asked Questions (FAQs)
Q1: How do I calculate the current-limiting resistor value?
A: Use the formula R = (Vsupply - VF) / IF. For a 5V supply, using the minimum VF from the datasheet (1.7V) and a target IF of 20mA: R = (5 - 1.7) / 0.02 = 165 Ω. Choose the nearest standard value (e.g., 160 Ω or 180 Ω) and verify power rating.
Q2: Can I drive this LED without a resistor if my supply voltage matches the typical VF (2.0V)?
A: No. The VF has a range (1.7V-2.4V). A supply of 2.0V could overdrive LEDs with a lower actual VF. Furthermore, VF decreases with temperature, creating a risk of thermal runaway. Always use a series resistor.
Q3: What does the "brilliant yellow" color specification mean?
A: It refers to the specific hue of yellow produced by the AIGaInP chip, characterized by a dominant wavelength in the 585-595 nm range. It is a saturated, vivid yellow color.
Q4: Why is there a 7-day limit after opening the moisture-proof bag?
A: Kayan SMD na iya ɗaukar danshi daga iska. A lokacin haɗa gabaɗaya, wannan danshin da ke ciki zai iya faɗaɗa cikin sauri ("tasirin guguwa"), wanda ke haifar da rabuwar ciki ko fashewa. Rayuwar ƙasa na kwanaki 7 da umarnin gasa suna sarrafa wannan haɗarin.
11. Design and Usage Case Study
Yanayi: Ƙirƙirar allon nuna matsayi don na'urar kiwon lafiya mai ɗaukuwa.
Requirements: Multiple status LEDs (Power, Battery Low, Error), very limited board space, must withstand occasional cleaning, consistent brightness and color across all units.
Implementation with 17-21/Y2C LED:
- Component Selection: Specify LEDs from a single intensity bin (e.g., P1) and wavelength bin (e.g., D4) to ensure visual consistency.
- PCB Layout: Utiliza la huella pequeña de 1.6x0.8mm para colocar 3-4 LEDs en fila dentro de un área muy reducida. Sigue el patrón de soldadura recomendado para una soldadura confiable.
- Circuit Design: Utiliza un bus común de 3.3V. Calcula la resistencia para cada LED: R = (3.3 - 1.7) / 0.02 = 80 Ω (usa 82 Ω). Verifica la potencia de la resistencia: P = I2R = (0.02)2*82 = 0.033W, so a 0603 or 0402 package resistor is sufficient.
- Assembly Process: Keep reels sealed until the production line is ready. Follow the exact reflow profile. Perform visual inspection post-solder.
- Result: A compact, reliable indicator panel with uniform bright yellow signals that meets the space, reliability, and aesthetic requirements.
12. Operating Principle
This LED is a semiconductor photonic device. Its core is a chip made from AIGaInP (Aluminum Gallium Indium Phosphide) materials. When a forward voltage exceeding the diode's junction potential (VF) is applied, electrons and holes are injected into the active region of the semiconductor. These charge carriers recombine, releasing energy in the form of photons (light). The specific composition of the AIGaInP layers determines the bandgap energy, which directly corresponds to the wavelength (color) of the emitted light—in this case, brilliant yellow (~591 nm). The epoxy resin encapsulant protects the chip, acts as a lens to shape the light output (achieving the 140-degree viewing angle), and may contain phosphors or dyes, though for a water-clear brilliant yellow, it is typically unmodified.
13. Industry Trends and Context
The 17-21 SMD LED represents a mature and widely adopted package standard in the electronics industry. Current trends influencing this product segment include:
- Increased Miniaturization: While 17-21 (1608 metric) remains popular, there is a continuous push towards even smaller packages like 15-21 (1508) and 10-20 (1005) for ultra-compact devices.
- Higher Efficiency: Ongoing improvements in epitaxial growth and chip design aim to deliver higher luminous intensity (mcd) at the same or lower drive currents, improving overall system energy efficiency.
- Enhanced Color Consistency: Tighter binning specifications and advanced manufacturing controls are reducing variation within and across production lots, which is critical for applications requiring uniform appearance.
- Broadening Environmental Compliance: Beyond RoHS and REACH, there is growing attention to full material declarations and reducing the use of other substances of concern throughout the supply chain.
- Integration: A trend towards integrating multiple LED chips (RGB, or multiple monochrome) into a single package, or combining the LED with driver ICs, is observed for more advanced lighting and signaling solutions, though simple discrete LEDs like this one remain fundamental for basic indicator functions.
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. | Kowane raguwar zafin jiki na 10°C na iya ninka tsawon rayuwa; yawan zafi yana haifar da raguwar haske, canjin launi. |
| 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. |
| Ufinyuaji wa Fosfori | 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 | Standard ya kukadiria maisha | Inakadiria maisha chini ya hali halisi kulingana na data ya LM-80. | 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. |