SMD LED 17-21 Deep Red Light Datasheet - Size 1.6x0.8x0.6mm - Voltage 1.75-2.35V - Power 60mW - Chinese Technical Documentation

1. Product Overview

This document details the specifications of a surface-mount deep red LED utilizing a compact 17-21 package. This component is designed for modern electronic assembly, offering a significant reduction in size and weight compared to traditional lead-frame LEDs. Its primary advantages include: enabling smaller printed circuit board (PCB) designs, higher component assembly density, and ultimately contributing to more compact and lightweight end-user devices.

1.1 Core Features and Compliance

该 LED 以 8mm 载带形式提供，卷绕在 7 英寸直径的卷盘上，完全兼容自动化贴片组装设备。它适用于红外（IR）和气相回流焊工艺。该器件为单色类型，发射深红光。采用无铅材料制造，并符合关键的环境与安全法规，包括欧盟 RoHS 指令、欧盟 REACH 法规以及无卤素要求（Br <900 ppm，Cl <900 ppm，Br+Cl < 1500 ppm）。

1.2 Target Applications

Wannan LED ya dace da aikace-aikacen nuna alama da hasken baya da yawa. Amfanin gama gari sun haɗa da: hasken baya na dashboard da maɓalli, alamun yanayi da hasken maɓalli a cikin na'urorin sadarwa kamar waya da na'urar fax, hasken baya na LCD mai lebur, da aikace-aikacen nuna alama na gama gari waɗanda ke buƙatar ƙaramin hasken ja mai dogaro.

2. Technical Parameters: An In-depth Objective Interpretation

The following sections provide a detailed and objective analysis of the LED's electrical, optical, and thermal characteristics based on datasheet parameters. Unless otherwise specified, all ratings are specified at an ambient temperature (Ta) of 25°C.

2.1 Absolute Maximum Ratings

These ratings define the limits beyond which permanent damage to the device may occur. Operation at or beyond these conditions is not guaranteed and should be avoided in circuit design.

• Reverse Voltage (VR):5V. Exceeding this reverse voltage may cause junction breakdown.
• Continuous Forward Current (IF):25 mA. This is the maximum DC current recommended for reliable long-term operation.
• Peak Forward Current (IFP):60 mA. This current is only permitted under pulse conditions with a duty cycle of 1/10 and a frequency of 1 kHz, and cannot be used continuously.
• Power Dissipation (Pd):60 mW. This is the maximum power that can be dissipated by the package without exceeding its thermal limits.
• Electrostatic Discharge (ESD) Human Body Model (HBM):2000V. This indicates the device's sensitivity to static electricity; proper ESD handling procedures must be followed.
• Operating Temperature (Topr):-40°C to +85°C. This is the specified ambient temperature range in which the device can operate.
• Storage Temperature (Tstg):-40°C to +90°C. This is the storage temperature range for the device when it is not powered.
• Welding Temperature (Tsol):For reflow soldering, the peak temperature is specified as 260°C for a maximum of 10 seconds. For manual soldering, the soldering iron tip temperature should not exceed 350°C, with a maximum of 3 seconds per terminal.

2.2 Photoelectric Characteristics

These parameters define the optical output and electrical behavior of the LED under normal operating conditions (IF=20mA, Ta=25°C).

• Luminous Intensity (Iv):The range is from a minimum of 36.00 mcd to a maximum of 90.00 mcd. No typical value is specified, indicating performance is managed through a binning system (see Section 3).
• Viewing Angle (2θ1/2):The typical full viewing angle at half intensity is 140 degrees, providing a wide emission pattern.
• Peak Wavelength (λp):The typical wavelength for maximum optical power output is 639 nanometers (nm), located in the deep red region of the spectrum.
• Dominant Wavelength (λd):The perceived color wavelength range is from 625.5 nm to 637.5 nm. This is also managed through binning.
• Spectral Bandwidth (Δλ):The typical full width at half maximum (FWHM) of the emission spectrum is 20 nm.
• Forward Voltage (VF):At 20mA, the range is from 1.75V to 2.35V. This parameter is binned.
• Reverse Current (IR):Maximum 10 μA when a 5V reverse voltage is applied. The datasheet clearly states that this device is not designed for reverse operation; this test parameter is for quality assurance only.

Important Note:The datasheet specifies manufacturing tolerances: luminous intensity (±11%), dominant wavelength (±1nm), and forward voltage (±0.1V). These apply to the binned values.

3. Binning System Description

To ensure consistency in mass production, LEDs are sorted (binned) based on key performance parameters. This allows designers to select components that meet specific brightness and color requirements for their applications.

3.1 Luminous Intensity Binning

Based on the luminous intensity measured at IF=20mA, LEDs are sorted into four bins (N2, P1, P2, Q1). For example, the intensity of a Q1 bin LED will be between 72.00 and 90.00 mcd.

3.2 Dominant Wavelength Binning

Perceived color (hue) is controlled through three wavelength bins (E6, E7, E8). LEDs in the E6 bin have a dominant wavelength between 625.50 nm and 629.50 nm, producing a slightly different shade of red compared to the E8 bin (633.50 nm to 637.50 nm).

3.3 Forward Voltage Binning

Forward voltage is divided into three groups (0, 1, 2). This is crucial for designing current-limiting circuits, especially when driving multiple LEDs in series, to ensure uniform current distribution. The VF of grade 0 LEDs ranges from 1.75V to 1.95V, while that of grade 2 LEDs ranges from 2.15V to 2.35V.

4. Performance Curve Analysis

Although the provided PDF excerpt indicates the "Typical Electro-Optical Characteristics Curves" section, the specific charts (e.g., IV curve, relative intensity vs. current, relative intensity vs. temperature, spectral distribution) are not included in the text content. In the complete datasheet, these curves are essential for design. They typically show:

• Forward Current vs. Forward Voltage (IV Curve):It shows a non-linear relationship, which helps determine dynamic resistance and the required drive voltage for a given current.
• Relative Luminous Intensity vs. Forward Current:Shows how light output increases with current, typically exhibiting saturation effects at high currents.
• Relative luminous intensity vs. ambient temperature:Shows the decrease in light output as junction temperature rises, which is crucial for thermal management.
• Normalized Spectral Distribution:Plot the relative intensity versus wavelength to visually confirm the peak wavelength (639nm) and spectral bandwidth (20nm).

Designers should refer to the complete datasheet containing graphs to accurately simulate the LED's behavior under non-standard conditions (different current or temperature).

5. Mechanical and Packaging Information

5.1 Package Dimensions and Polarity

This LED uses a standard 17-21 SMD package outline. The key dimensions (in millimeters) are critical for PCB pad pattern design. The package is marked with a cathode for polarity identification. A typical pad pattern should have two pads corresponding to the anode and cathode terminals, with recommended pad sizes and spacing to ensure proper soldering and mechanical stability. The exact dimensions should be obtained from the "Package Dimensions" drawing in the datasheet.

5.2 Moisture Sensitivity and Packaging

An tattara wannan na'urar a cikin jakar shinge mai hana danshi tare da busassun abu, don hana shan danshin yanayi, wanda zai iya haifar da "fashewar gasa" (tsagewar kunshe) yayin aikin sake zafi mai zafi. Alamar da ke kan jakar ta ƙunshi mahimman bayanai don gano asali da aikace-aikace: Lambar Samfurin Abokin Ciniki (CPN), Lambar Samfura (P/N), Adadin Kunshe (QTY), da takamaiman lambobin rarrabuwa don Ƙarfin Haskakawa (CAT), Babban Tsawon Tsawon (HUE) da Ƙarfin Lantarki na Gaba (REF).

5.3 Reel and Tape Specifications

Components are supplied in embossed carrier tape, wound on 7-inch reels. The carrier tape dimensions (pocket size, pitch) and reel dimensions (hub diameter, flange diameter) are standardized for compatibility with automated assembly equipment. The quantity per reel is specified as 3000 pieces.

6. Welding and Assembly Guide

Adhering to these guidelines is crucial for assembly yield and long-term reliability.

6.1 Storage and Operation

• Do not open the moisture barrier bag until ready for use.
• After opening, unused LEDs should be stored in an environment of ≤30°C and ≤60% relative humidity (RH).
• The "floor life" after opening the bag is 168 hours (7 days). Unused components exceeding this period must be rebaked (60±5°C, 24 hours) and repacked with new desiccant before use.
• Always follow ESD (Electrostatic Discharge) safe handling procedures.

6.2 Reflow Soldering Temperature Profile

Defines the lead-free reflow soldering temperature profile. Key parameters include:

• Preheat:150-200°C, for 60-120 seconds.
• Time above liquidus (217°C):60-150 seconds.
• Peak temperature:Maximum 260°C.
• Time within peak temperature ±5°C:Maximum 10 seconds.
• Maximum heating rate:6°C/sec.
• Time above 255°C:Maximum 30 seconds.
• Maximum cooling rate:3°C per second.

Key rules:The same LED should not undergo reflow soldering more than twice.

6.3 Manual Soldering and Rework

If manual soldering is necessary, use a soldering iron with a tip temperature ≤350°C and heat each terminal for ≤3 seconds. Use a low-power soldering iron (≤25W) and allow a cooling interval of ≥2 seconds between terminals. The datasheet strongly advises against rework after LED soldering. If absolutely necessary, a dedicated dual-tip soldering iron must be used to simultaneously heat both terminals during removal to avoid mechanical stress, and the impact on LED characteristics must be verified.

7. Application Recommendations and Design Considerations

7.1 Rate limiting must be used.

LED is a current-driven device. The datasheet explicitly warns that a series current-limiting resistor must be used. The forward voltage has a negative temperature coefficient. Due to the exponential I-V characteristic of the diode, a small change can lead to a large variation in current, potentially causing thermal runaway and failure.MustUse. The forward voltage has a negative temperature coefficient. Due to the exponential IV characteristic of the diode, a small change may lead to a huge change in current, which may cause thermal runaway and failure.

7.2 Thermal management.

Although the package is small, the 60mW power dissipation limit must be observed. Operation at high ambient temperature or high current will reduce light output and lifetime. If operating near the maximum ratings, ensure sufficient PCB copper area or thermal vias are used.

7.3 Optical Design

The 140° viewing angle provides a wide, diffuse light pattern suitable for area lighting or indicator lights that need to be visible from all angles. For more focused light, an external lens or reflector is required.

8. Technical Comparison and Differentiation

The key differentiation of this 17-21 deep red LED lies in its combination of specific semiconductor material (AIGaInP) and a highly compact surface-mount package.

• Compared to old through-hole LEDs:Provide huge space savings, weight reduction, and compatibility with high-speed automated assembly, thereby lowering overall manufacturing costs.
• Compared to other SMD red LEDs:Compared to some other material systems used for red light emission, the use of AIGaInP technology typically offers higher efficiency and better stability in temperature performance. The choice of the specific 639nm peak/deep red color may be due to its visual distinctiveness or effectiveness in certain sensor applications.
• Compared to larger SMD packages (e.g., 3528, 5050):The 17-21 package is significantly smaller, enabling ultra-miniaturized designs, but total light output is generally lower due to its smaller chip size and thermal limitations.

8.1 Working Principle

Light is generated through the process of electroluminescence within an AIGaInP (aluminum gallium indium phosphide) semiconductor chip. When a forward voltage is applied, electrons and holes are injected into the active region of the semiconductor junction. As these charge carriers recombine, they release energy in the form of photons (light). The specific composition of the AIGaInP alloy determines the bandgap energy, which directly defines the wavelength (color) of the emitted light—in this case, a deep red light at approximately 639 nm.

9. Frequently Asked Questions (Based on Technical Parameters)

Q: Can I drive this LED directly with a 3.3V or 5V logic supply?
A: No. You must always use a series current-limiting resistor. The required resistor value is calculated using Ohm's Law: R = (Supply Voltage - LED Forward Voltage) / Desired Current. For a conservative design, using maximum VF (2.35V), a 3.3V supply, and a target current of 20mA: R = (3.3 - 2.35) / 0.02 = 47.5Ω. A standard 47Ω or 51Ω resistor is suitable.

Q: Why is luminous intensity given as a range and in bins?
A: Due to inherent variations in semiconductor manufacturing processes, the performance of individual LEDs differs slightly. Binning classifies them into groups with guaranteed minimum and maximum values, allowing designers to select the appropriate brightness grade based on their cost and performance requirements.

Q: What happens if the floor life exceeds 7 days after opening the bag?
A: Absorbed moisture can turn into steam during the reflow soldering process, potentially causing internal delamination or cracking. These components must be reprocessed by baking at 60°C for 24 hours before use.

Q: Is this LED suitable for automotive dashboard lighting?
A: Although "dashboard backlighting" is listed as an application, the datasheet includes an "Application Restrictions" section. It warns that high-reliability applications like automotive safety/security systems may require different, more rigorously certified products. For non-critical dashboard lighting, it might be suitable, but for safety-critical indicator lights, products specifically compliant with automotive standards (e.g., AEC-Q102) should be procured.

10. Practical Design and Usage Cases

Scenario: Designing a compact status indicator panel.A designer needs to use multiple deep red status LEDs on a component-dense control board. They selected the 17-21 LED for its small size. They specified the Q1 brightness bin and E7 wavelength bin to ensure all indicators have a bright, consistent color. For the PCB layout, they used the recommended land pattern from the datasheet. They designed the drive circuit using a 3.3V regulator, a 51Ω current-limiting resistor per LED (yielding approximately 18-20mA current), and placed small thermal relief pads. During assembly, they ensured factory-sealed reels were used within their workshop shelf life and followed the specified reflow soldering temperature profile. This resulted in a reliable, compact indicator system.

11. Technology Trends

The overall trend in LED technology (including indicator lights) is developing towards several key areas:

• Efficiency Enhancement:Ongoing improvements in materials science aim to produce more light (lumens) per unit of electrical input power (watts), thereby reducing energy consumption and thermal load.
• Miniaturization:Packaging continues to shrink (e.g., from 17-21 to smaller form factors like 10-05) to enable smaller electronic devices.
• Higher Reliability and Robustness:Improvements in packaging materials and die attach technology enhance lifespan and resistance to thermal cycling and moisture.
• Integration:The trend is to integrate multiple LEDs (e.g., RGB), control ICs, and even passive components into a single, smarter modular package.
• Standardization and Compliance:More stringent and extensive environmental regulations (RoHS, REACH, Halogen-Free) continue to drive material changes across the industry.