LTST-C171TBKT-5A SMD Chip Blue LED Datasheet - 0.8mm Ultra-Thin Height - 2.8V-3.05V Forward Voltage - 76mW Power Consumption - Technical Documentation

1. Product Overview

This document provides the complete technical specifications for the LTST-C171TBKT-5A, a Surface Mount Device (SMD) Light Emitting Diode (LED) chip. This product belongs to an ultra-thin, high-brightness blue LED series specifically designed for modern electronic assembly processes. The primary application of this component is as an indicator light, backlight, or status display, widely used in compact electronic devices where space and height are critical limiting factors.

The core advantage of this LED lies in its extremely small form factor, with a height of only 0.80 millimeters. This makes it suitable for applications in ultra-thin consumer electronics, portable devices, and high-density PCBs. Its manufacturing process is compatible with automatic pick-and-place equipment, ensuring efficiency in large-scale assembly. The device also complies with the RoHS (Restriction of Hazardous Substances) directive, classifying it as a green product suitable for global markets with strict environmental regulations.

Target markets include manufacturers of office automation equipment, communication devices, home appliances, and various industrial control panels. Its compatibility with infrared (IR) and vapor phase reflow soldering processes makes it suitable for standard and lead-free (Pb-free) assembly lines used in mass production.

2. Bincike mai zurfi na sigogi na fasaha

This section provides an objective and detailed interpretation of the key technical parameters specified in the datasheet.

2.1 Matsakaicin iyaka na cikakke

Absolute maximum ratings define the stress limits that may cause permanent damage to the device. These are not normal operating conditions.

• Power Dissipation (Pd):76 mW. This is the maximum power the LED can dissipate as heat at an ambient temperature (Ta) of 25°C. Exceeding this limit may cause thermal damage to the semiconductor junction.
• DC Forward Current (IF):20 mA. This is the maximum recommended continuous forward current to ensure long-term reliable operation.
• Peak Forward Current:100 mA. This rating applies only under pulsed conditions with an extremely low duty cycle (1/10) and very short pulse width (0.1ms). It is associated with brief, high-intensity flashes and is not suitable for constant illumination.
• Reverse Voltage (VR):5 V. Applying a reverse bias voltage exceeding this value may cause the PN junction breakdown and failure of the LED.
• Operating Temperature Range:-20°C to +80°C. Ensures the device operates normally within this ambient temperature range.
• Storage Temperature Range:-30°C to +100°C. The device will not experience performance degradation when stored within this range.
• Soldering Temperature Tolerance:The datasheet specifies conditions for wave soldering (260°C, 5 seconds), infrared reflow soldering (260°C, 5 seconds), and vapor phase reflow soldering (215°C, 3 minutes). These are crucial for PCB assembly without damaging the LED package.

2.2 Halaye na lantarki da na gani

These parameters are measured under standard test conditions (Ta=25°C) and define the performance of the device.

• Luminous Intensity (Iv):At a forward current (IF) of 5 mA, the typical value is 15.0 mcd. The minimum guaranteed value is 11.2 mcd. This is the perceived brightness of the LED by the human eye, measured using a filter approximating the CIE photopic response curve.
• Forward Voltage (VF):At IF=5mA, the typical value is 2.80 V, and the maximum value is 3.05 V. This is the voltage drop across the LED when it conducts current. It is a key parameter for designing the current limiting circuit.
• Viewing Angle (2θ1/2):Typical value is 130 degrees. This wide viewing angle indicates that the LED emits light over a broad cone angle, making it suitable for applications where visibility from multiple angles is important.
• Peak Emission Wavelength (λP):468 nm. This is the wavelength at which the spectral power output is highest.
• Dominant Wavelength (λd):470.0 nm to 475.0 nm at IF=5mA. This is derived from the CIE chromaticity diagram and represents the single wavelength that best describes the color of the light as perceived by the human eye. For color specification, it is a more relevant parameter than the peak wavelength.
• Spectral Line Half-Width (Δλ):Typical value is 25 nm. This measures the bandwidth of the emission spectrum at half of its maximum intensity. A value of 25 nm is characteristic of blue InGaN LEDs.
• Reverse Current (IR):A VR=5V, mafi girman shine 10 μA. Wannan shine ƙaramin kwararar ruwa da ke gudana lokacin da LED ke cikin jujjuyawar baya a cikin iyakar ƙimar sa.

2.3 Halaye na zafi

Aikin zafi ana bayyana shi ta hanyar ƙimar rage daraja. Lokacin da yanayin zafi ya wuce 50°C, kowane haɓakar digiri 1, dole ne a rage madaidaicin kwararar gaba na DC da 0.25 mA. Wannan yana da mahimmanci don tabbatar da amincin aiki a yanayin zafi mafi girma. Misali, a matsakaicin yanayin aiki na 80°C, matsakaicin ƙimar ci gaba da gudana shine: 20 mA - [0.25 mA/°C * (80°C - 50°C)] = 20 mA - 7.5 mA = 12.5 mA.

3. Grading System Description

Don sarrafa bambance-bambancen halitta a cikin tsarin kera semiconductor, ana rarraba LED zuwa matakai daban-daban na aiki. Wannan yana ba masu zane damar zaɓar kayan aiki tare da ingantaccen sarrafa halaye don aikace-aikacensu.

3.1 Forward Voltage Grading

Dangane da ƙarfin lantarki na gaba (VF) da aka auna a 5 mA, ana rarraba LED zuwa matakai huɗu.

• Mataki 1: 2.65 V - 2.75 V
• Mataki 2: 2.75 V - 2.85 V
• Mataki 3: 2.85 V - 2.95 V
• Mataki 4: 2.95 V - 3.05 V

Matsakaicin kuskure a cikin kowane mataki shine ±0.1 V. Yin amfani da LED daga matakin wutar lantarki iri ɗaya a cikin da'irar layi daya yana taimakawa wajen samun rarraba ƙarfi da haske mafi daidaito.

3.2 Luminous Intensity Grading

Dangane da ƙarfin haskakawa (Iv) a 5 mA, ana rarraba LED zuwa matakai shida, daga L1 (mafi ƙanƙanta) zuwa N2 (mafi girma).

• L1: 11.2 mcd - 14.0 mcd
• L2: 14.0 mcd - 18.0 mcd
• M1: 18.0 mcd - 22.4 mcd
• M2: 22.4 mcd - 28.0 mcd
• N1: 28.0 mcd - 35.5 mcd
• N2: 35.5 mcd - 45.0 mcd

Kowane matakin ƙarfin yana da ƙarancin kusan ±15%. Wannan rarrabuwa yana da mahimmanci ga aikace-aikacen da ke buƙatar daidaiton haske tsakanin fitilun nuni da yawa.

3.3 Dominant Wavelength Grading

Ga wannan takamaiman nau'in, duk na'urorin suna cikin rukunin babban tsawon zango guda: AD, wanda ke tsakanin 470.0 nm zuwa 475.0 nm. Wannan rukunin yana da ƙarancin ±1 nm, yana tabbatar da fitowar hasken shuɗi mai matuƙar daidaito.

4. Performance Curve Analysis

Ko da yake takaddun ƙayyadaddun bayanai suna ambaton takamaiman lankwalan zane (Hoto 1, Hoto 6), ana iya siffanta halayen su na yau da kullun bisa ga ka'idodin LED na yau da kullun da kuma sigogin da aka bayar.

4.1 Current vs. Voltage (I-V) Characteristics

Jadawalin I-V na irin wannan LED na InGaN shuɗi ba mai layi ba ne. Ƙasa da bakin kofa na ƙarfafawa (kimanin 2.6-2.7V), kusan babu wani ƙarfin lantarki da ke gudana. Lokacin da ƙarfafawa ya kusanci kuma ya wuce ƙimar VF ta yau da kullun na 2.8V, ƙarfin lantarki yana ƙaruwa cikin sauri. Wannan shine dalilin da ya sa dole ne a sarrafa LED ta hanyar tushen iyakance ƙarfin lantarki, ba tushen ƙarfafawa mai dorewa ba. Ƙananan bambance-bambance a tsakanin VF na kowane na'ura (kamar yadda aka nuna a cikin rarrabuwa) suna faruwa ne saboda ƙananan bambance-bambance a cikin yadudduka na semiconductor da sarrafa guntu.

4.2 Luminous Intensity vs. Forward Current

A cikin wani yanki mai faɗi, fitar da haske (ƙarfin haske) yana kusan daidai da ƙarfin lantarki mai gaba. Duk da haka, a cikin ƙarfin lantarki mai girma sosai, inganci yana raguwa saboda ƙarin zafi (tasirin raguwar inganci). Ƙimar ƙarfin lantarki mai gaba na DC na 20 mA zaɓi ne don samun daidaito tsakanin haske mai kyau da dogon lokacin aminci.

4.3 Spectral Distribution

Jadawalin fitarwa na bakan zai nuna babban kololuwa a kusan 468 nm (shuɗi). Faɗin rabin 25 nm yana nuna tsaftar bakan. A cikin fitarwa na ingantaccen LED na InGaN shuɗi, ba za a sami wani ƙaramin kololuwa mai mahimmanci ba. Babban tsayin raƙuman ruwa na 470-475 nm yana sanya launin wannan LED a cikin daidaitaccen yanki na shuɗi.

4.4 Temperature Dependence

As the junction temperature increases, the forward voltage typically decreases slightly (negative temperature coefficient), while the luminous intensity and dominant wavelength may shift. The derating specification directly addresses the need to reduce current in high-temperature environments to manage junction temperature and maintain performance and lifetime.

5. Mechanical and Packaging Information

5.1 Package Dimensions

This LED uses an EIA standard package. A key mechanical feature is its ultra-thin profile, with a height (H) of 0.80 mm. All other dimensions (length, width, lead pitch) conform to the standard footprint for this package type, ensuring compatibility with automated assembly equipment and standard PCB pad patterns. The lens material is specified as "Water Clear," a colorless, transparent epoxy that does not diffuse light, resulting in a clear, focused beam from the chip.

5.2 Polarity Identification

The datasheet includes a package outline drawing that clearly indicates the cathode and anode terminals. Typically, the cathode is marked by a notch, a green dot, or a shorter lead/tab on the package body. Correct polarity must be observed during PCB assembly, as applying reverse bias may damage the device.

5.3 Recommended Pad Layout

A recommended land pattern (pad dimensions and spacing) is provided to ensure good solder joint formation, mechanical stability, and thermal relief during reflow. Adhering to this guideline is crucial for achieving high assembly yield and reliability.

6. Soldering and Assembly Guide

6.1 Reflow Soldering Profile

The datasheet provides two recommended infrared (IR) reflow profiles: one for conventional (tin-lead) soldering processes and one for lead-free processes. The key parameters are:

• Preheating:Gradually increase temperature to activate the flux and minimize thermal shock.
• Soak/Preheat Time:Maximum 120 seconds to prevent excessive oxidation.
• Peak Temperature:Maximum 260°C. The LED can only withstand this temperature for a very limited time.
• Time Above Liquidus (TAL):For lead-free processes, the profile must ensure the solder paste melts for the correct duration to form a reliable joint, typically referencing the time between specific temperature lines (e.g., 217°C for SnAgCu solder).

Strict adherence to these profiles is critical. Excessive time or temperature during reflow can damage the LED's epoxy lens, degrade semiconductor chip performance, or weaken internal wire bonds.

6.2 Storage Conditions

LEDs are moisture-sensitive devices. If removed from the original moisture barrier bag, they must be used within 672 hours (28 days) or baked prior to soldering to remove absorbed moisture. Long-term storage outside the original bag requires a controlled environment: a sealed container with desiccant or a nitrogen-purged dry box. Failure to follow these procedures may lead to "popcorning" during reflow, where internal vapor pressure causes the package to crack.

6.3 Cleaning

If post-solder cleaning is required, only specified solvents should be used. The datasheet recommends immersion in ethanol or isopropyl alcohol at room temperature for no more than one minute. Using harsh or unspecified chemicals may cloud, crack, or otherwise damage the LED's epoxy lens.

7. Packaging and Ordering Information

7.1 Tape and Reel Specifications

LEDs are supplied in industry-standard embossed carrier tape, wound on 7-inch (178 mm) diameter reels. This packaging is compatible with high-speed automatic placement machines.

• Quantity per reel:3000 pieces.
• Minimum packaging quantity:Minimum order quantity is 500 pieces for remaining stock.
• Cover tape:Empty component pockets are sealed with top cover tape.
• Missing component:According to quality standards, the maximum number of consecutive missing components in the tape is two.
• Standard:Packaging complies with ANSI/EIA 481-1-A-1994 specification.

8. Application Recommendations

8.1 Yanayin Aikace-aikace na Al'ada

• Status Indicator Light:Power-on, standby, charging, or error indicator lights in consumer electronics, appliances, and network equipment.
• Backlight:For small LCD displays, keyboards, or membrane switches in thin-profile devices.
• Panel Illumination:Illumination for instrument panels, control panels, and industrial HMI devices.
• Decorative Lighting:Accent lighting in compact spaces where an ultra-thin profile is critical.

8.2 Abubuwan da Ya Kamata a Lura a Zane na Lantarki

Key Point: LED is a current-driven device.The most important design rule is to control the forward current.

• Current Limiting Resistor (Circuit Model A):When multiple LEDs are connected in parallel, it is necessary toeachLED use an independent current limiting resistor in series. This is because the forward voltage (VF) may have slight variations between different LEDs (as defined by binning). Without separate resistors, LEDs with lower VF will draw disproportionately more current, leading to uneven brightness and potential overload of those units. The resistor value is calculated using Ohm's Law: R = (Power Supply Voltage - LED's VF) / Desired Current.
• Parallel Connection Without Resistor (Circuit Model B):This configurationis not recommended.because natural differences in I-V characteristics can lead to uneven brightness and unreliable operation.
• Series connection:Connecting LEDs in series ensures they all pass the same current. A single current-limiting resistor can be used for the entire series branch. The power supply voltage must be high enough to overcome the sum of all forward voltages in the branch.

8.3 Kariya daga Electrostatic Discharge (ESD)

LEDs are sensitive to electrostatic discharge. Precautions must be taken during handling and assembly:

• Operatzaileek lurperatutako eskumuturreko banda edo estatikoki babestutako eskularruak eraman behar dituzte.
• Lanpostu, tresna eta ekipo guztiak behar bezala lurperatu behar dira.
• LEDak ESD segurtasuneko paketatzean gorde eta garraiatu.

9. Kwatancen Fasaha da Bambance-bambance

LED urdin orokor edo zaharragoekin alderatuta, LED honen bereizketa-faktore nagusiak hauek dira:

• Itxura oso mehea (0.8mm altuera):It enables the design of thinner end products, a key requirement for modern smartphones, tablets, and ultrabooks.
• Standardized EIA Package:Ensures compatibility with automated assembly lines and existing PCB footprints, reducing design time and risk.
• Dual Soldering Process Compatibility:Certified for both standard (SnPb) and lead-free (SnAgCu) reflow processes, making designs compliant with global environmental regulations and future-proof.
• Full Binning:Provides designers the ability to select components with tightly controlled luminous intensity (Iv) and forward voltage (VF), resulting in more consistent performance in mass-produced products.
• High Brightness Option:Yana ba da zaɓi har zuwa matakin N2 (45.0 mcd), yana ba da sassauci ga aikace-aikacen da ke buƙatar ƙarin ganuwa.

10. Tambayoyin da ake yawan yi (Bisa sigogin fasaha)

10.1 Zan iya sarrafa wannan LED kai tsaye da wutar lantarki ta dabaru na 3.3V ko 5V?

A'a, ba za a iya tuƙa kai tsaye ba.Dole ne a yi amfani da resistor mai iyakancewa a jere. Misali, ta amfani da wutar lantarki na 3.3V, da manufar ƙarfin 5mA, ta amfani da ƙimar VF ta yau da kullun 2.8V: R = (3.3V - 2.8V) / 0.005A = 100 ohms. Idan babu resistor, LED zai yi ƙoƙarin ɗaukar ƙarfin da ya wuce kima, kawai ta hanyar iyakance wutar lantarki da juriyar cikin LED, wanda zai iya lalata shi.

10.2 Me ya sa ƙimar ƙarfin igiyar ruwa (100mA) ta yi yawa fiye da ƙimar DC (20mA)?

Ƙimar ƙarfin kololuwa tana aiki ne ga ɗan gajeren bugun jini (0.1ms) na ƙananan aiki (10%). A cikin waɗannan sharuɗɗan, haɗin semiconductor ba shi da lokaci don yin girma sosai. Don ci gaba da aiki (DC), tarin zafi shine abin iyakancewa, don haka ƙimar ƙaramin 20mA don tabbatar da dogon lokaci na aminci da hana guduwar zafi.

10.3 Menene bambanci tsakanin tsayin raƙuman ruwa mai kololuwa da babban tsayin raƙuman ruwa?

Tsayin zango (λP)Shi ne ainihin mafi girman batu akan lanƙwan fitarwa na bakan (468 nm).Babban tsayin zango (λd)Ƙimar lissafi ce (470-475 nm) wacce ta dace da launin da idon mutum ya fahimta akan taswirar launi ta CIE. Don ƙayyadaddun launi a aikace-aikace, babban tsayin zango shine mafi dacewa.

10.4 LED yana aiki daidai bayan walda, amma daga baya ya ƙare. Menene yuwuwar dalilin?

Dalilai na yau da kullun sun haɗa da: lalacewar ESD yayin aiki, matsanancin zafi yayin walda (wuce iyakar lokaci/zazzabi), kuskuren polarity akan PCB, yawan ƙarfin turawa saboda rashin ko kuskuren lissafin resistor mai iyakancewa, ko lalacewar da ruwa ya haifar saboda rashin adana kayan aikin da ke da hankali ga danshi (Popcorn effect).

11. Nazarin Lamarin Ƙirar Aiki

Scenario:Design a control panel with four blue status indicator lights. This panel is powered by a 5V power rail. Uniform brightness is crucial for aesthetics.

1. LED Selection:Select LEDs from the same luminous intensity bin (e.g., all from bin M1: 18.0-22.4 mcd) and the same forward voltage bin (e.g., all from bin 2: 2.75-2.85V) to minimize inherent variations.
2. Circuit Design:Use Circuit Model A. Connect each LED in parallel with its own series resistor. For a target current of 5mA and a conservative VF value of 2.85V (the maximum of bin 2), calculate R = (5V - 2.85V) / 0.005A = 430 ohms. The nearest standard values are 430Ω or 470Ω.
3. PCB Layout:Follow the recommended pad dimensions in the specification document. Ensure correct polarity alignment based on the package marking.
4. Assembly:Use the recommended lead-free reflow profile. Ensure the LED is used within 672 hours after opening the moisture barrier bag or undergo proper baking.
5. Result:Four indicator lights with consistent brightness and color, reliable long-term operation, and high manufacturing yield.

12. Ka'idodin Aiki

LTST-C171TBKT-5A is a semiconductor device based on indium gallium nitride (InGaN) material. When a forward bias voltage exceeding the junction's built-in potential is applied, electrons from the n-type region and holes from the p-type region are injected into the active region. When these carriers recombine, they release energy in the form of photons (light). The specific composition of the InGaN alloy in the active layer determines the bandgap energy, which in turn determines the wavelength (color) of the emitted light. For this device, the bandgap is engineered to produce photons in the blue spectrum (approximately 470 nm). A transparent epoxy lens encapsulates and protects the semiconductor chip, provides mechanical stability, and shapes the light output beam.

13. Trends na Fasaha

Bu tür SMD LED'lerin gelişimi, birkaç belirgin endüstri trendini takip eder:

• Küçültme:Daha ince ve daha kompakt elektronik ürünler elde etmek için sürekli olarak azaltılan paket boyutları (yer kaplama alanı ve yükseklik).
• Verimlilik Artışı:Taşınabilir cihazların pil ömrünü iyileştirmek için, aynı veya daha düşük sürücü akımında daha yüksek ışık şiddeti sağlamak amacıyla Internal Quantum Efficiency (IQE) ve ışık çıkarma verimliliğinde sürekli iyileştirmeler.
• Standardizasyon ve Otomasyon:Adhere to standardized package outlines and tape-and-reel formats to simplify large-scale automated manufacturing processes globally.
• Environmental Compliance:Elimination of hazardous substances (RoHS, REACH) and compatibility with lead-free (Pb-free) assembly processes are now standard requirements.
• Color Consistency:For applications where visual uniformity is critical (such as displays and signage), stricter binning tolerances for luminous intensity, forward voltage, and chromaticity coordinates are required.