Karatasi ya Kiufundi ya SMD LED LTST-S320TBKT - Mtazamo wa Upande - 3.2x1.6x1.2mm - 2.8-3.8V - 76mW - Bluu InGaN - Hati ya Kiufundi ya Kiswahili

1. Muhtasari wa Bidhaa Hati hii inatoa vipimo kamili vya kiufundi vya Kifaa cha Kuchomea cha Uso (SMD) cha Taa ya Kutoa Mwanga (LED) ya miniature, inayotazama upande. Kifaa hiki kimeundwa kwa ajili ya usanikishaji wa bodi ya mzunguko wa kuchapishwa (PCB) na inafaa kwa matumizi ambapo nafasi ni kikwazo muhimu. Muundo wake wa kompakt na utendaji wa kuaminika hufanya iwe sehemu bora kwa vifaa vya kisasa vya elektroniki.

1.1 Faida za Msingi na Soko Lengwa Faida kuu za LED hii ni pamoja na pato lake la mwangaza sana kutoka kwa chipu ya semiconductor ya InGaN (Indiamu Galiamu Nitraidi), pembe pana ya kuona ya digrii 130, na uwezo kamili wa kufanana na michakato ya kawaida ya uuzaji wa IR reflow inayotumiwa katika uzalishaji wa wingi. Kifurushi kina vipengele vya kupaka stani ili kuboresha uwezo wa kuuza na husambazwa kwenye tepi ya kawaida ya tasnia ya 8mm na reeli za inchi 7 kwa ajili ya ufanisi wa otomatiki ya kuchukua na kuweka.

Matumizi yanayolengwa yanajumuisha anuwai ya vifaa vya elektroniki vya watumiaji na viwanda. Kwa kawaida hutumiwa kwa dalili ya hali, mwanga wa nyuma wa kibodi, uangazaji wa alama kwenye paneli za udhibiti, na ujumuishaji katika maonyesho madogo. Uaminifu na utendaji wake unaufaa kwa vifaa vya mawasiliano, vifaa vya otomatiki ya ofisi, vifaa vya nyumbani, na mifumo mbalimbali ya udhibiti wa viwanda.

2. Uchambuzi wa Kina wa Vigezo vya Kiufundi Uelewa wa kina wa vigezo vya umeme na mwanga ni muhimu kwa ajili ya kubuni saketi sahihi na kufikia utendaji unaotarajiwa.

2.1 Viwango vya Juu Kabisa Viwango hivi hufafanua mipaka ambayo kuharibika kudumu kwa kifaa kunaweza kutokea. Vimebainishwa kwa joto la mazingira (Ta) la 25°C.

Mtawanyiko wa Nguvu (Pd): 76 mW. Hii ndiyo kiwango cha juu cha nguvu ambacho kifaa kinaweza kutawanya kwa usalama kama joto.

Umeme wa Mbele wa Endelevu (IF): 20 mA DC. Hii ndiyo umeme wa juu unaopendekezwa kwa uendeshaji wa muda mrefu unaoweza kutegemewa.

Umeme wa Mbele wa Kilele: 100 mA, inaruhusiwa tu chini ya hali ya mipigo (mzunguko wa kazi 1/10, upana wa mipigo 0.1ms). Kuzidi kiwango cha umeme wa DC, hata kwa muda mfupi, kunaweza kudhoofisha LED.

Safu ya Joto ya Uendeshaji: -20°C hadi +80°C. Kifaa kinahakikishiwa kufanya kazi ndani ya safu hii ya joto la mazingira.

• Safu ya Joto ya Uhifadhi: -30°C hadi +100°C.Joto la Uuzaji: Inastahimili uuzaji wa IR reflow na joto la kilele la 260°C kwa hadi sekunde 10, ambayo ni kawaida kwa michakato ya usanikishaji isiyo na risasi (Pb-free).
• 2.2 Sifa za Umeme na Mwanga Hizi ni vigezo vya kawaida vya utendaji vinavyopimwa kwa Ta=25°C na umeme wa mbele (IF) wa 20 mA, isipokuwa imesemwa vinginevyo.Nguvu ya Mwangaza (Iv): Inaanzia kiwango cha chini cha 28.0 millicandelas (mcd) hadi kiwango cha juu cha 180.0 mcd. Thamani halisi imedhamiriwa na kiwango cha bin cha kifaa (angalia Sehemu ya 3).
• Pembe ya Kuona (2θ1/2): Digrii 130. Hii ndiyo pembe kamili ambayo nguvu ya mwangaza hupungua hadi nusu ya thamani yake iliyopimwa kwenye mhimili wa kati. Kifurushi cha mtazamo wa upande kimeundwa kutolea mwanga perpendicular kwa ndege ya kufunga, na hii inafanya kuwa kigezo muhimu kwa matumizi ya uangazaji wa upande.Wavelength ya Utoaji wa Kilele (λP): Kwa kawaida 468 nanometers (nm), na kuweka katika eneo la bluu la wigo unaoonekana.
• Wavelength Kuu (λd): Inaanzia 465.0 nm hadi 475.0 nm. Hii ndiyo wavelength moja inayoonwa na jicho la mwanadamu ambayo hufafanua rangi.Nusu-Upana wa Mstari wa Wigo (Δλ): Takriban 25 nm. Hii inaonyesha usafi wa wigo au upana wa ukanda wa mwanga wa bluu unaotolewa.
• Voltage ya Mbele (VF): Inaanzia 2.8 Volts hadi 3.8 Volts kwa 20 mA. Hii ndiyo kushuka kwa voltage kwenye LED inapofanya kazi na ni muhimu kwa ubunifu wa kiendeshi.Umeme wa Nyuma (IR): Kiwango cha juu cha 10 microamperes (μA) wakati voltage ya nyuma (VR) ya 5V inatumika. LED hazijaundwa kwa uendeshaji wa upendeleo wa nyuma; kigezo hiki ni kwa madhumuni ya majaribio tu.
• 3. Maelezo ya Mfumo wa Kupanga Bin Kutokana na tofauti za uzalishaji, LED zimepangwa katika mabini ya utendaji. Mfumo huu huruhusu wabunifu kuchagua vifaa vilivyo na sifa zilizodhibitiwa kwa makini kwa utendaji thabiti wa matumizi.3.1 Kupanga Voltage ya Mbele (VF) LED zimepangwa kulingana na kushuka kwa voltage ya mbele kwa 20 mA. Mabini yanaanzia D7 (2.80V - 3.00V) hadi D11 (3.60V - 3.80V), na uvumilivu wa ±0.1V kwa kila bin. Kuchagua LED kutoka kwa bin sawa ya VF kunahakikisha mwangaza sawa na usambazaji wa umeme wakati vifaa vingi vimeunganishwa sambamba.

3.2 Kupanga Nguvu ya Mwangaza (Iv) Hii ndiyo kupanga kwa mwangaza wa msingi. Mabini yamefafanuliwa kama N (28.0-45.0 mcd), P (45.0-71.0 mcd), Q (71.0-112.0 mcd), na R (112.0-180.0 mcd), na uvumilivu wa ±15% kwa kila bin. Hii inaruhusu udhibiti sahihi wa kiwango cha pato la mwanga katika matumizi ya mwisho.

3.3 Kupanga Wavelength Kuu (λd) LED zimepangwa kulingana na nukta ya rangi. Kwa LED hii ya bluu, mabini ni AC (465.0-470.0 nm) na AD (470.0-475.0 nm), na uvumilivu mkali wa ±1 nm. Hii inahakikisha tofauti ndogo ya rangi kati ya LED tofauti katika safu au onyesho.

• 4. Uchambuzi wa Mkunjo wa Utendaji Data ya picha inatoa ufahamu wa kina zaidi juu ya tabia ya kifaa chini ya hali tofauti.4.1 Mkunjo wa Umeme wa Mbele dhidi ya Voltage ya Mbele (Mkunjo wa I-V) Tabia ya I-V sio ya mstari. Mkunjo unaonyesha kuwa ongezeko dogo la voltage zaidi ya kizingiti cha kuwasha (~2.8V) husababisha ongezeko la haraka la umeme. Kwa hivyo, LED lazima ziendeshwe na chanzo kilicho na kikomo cha umeme, sio chanzo cha voltage thabiti, ili kuzuia kukimbia kwa joto na uharibifu.
• 4.2 Nguvu ya Mwangaza dhidi ya Umeme wa Mbele Mkunjo huu unaonyesha kuwa pato la mwanga ni takriban sawia na umeme wa mbele ndani ya safu ya uendeshaji iliyopimwa. Hata hivyo, ufanisi (lumens kwa watt) unaweza kupungua kwa umeme wa juu sana kutokana na ongezeko la uzalishaji wa joto.4.3 Usambazaji wa Wigo Grafu ya pato la wigo inaonyesha kilele kimoja kilichozingatia karibu 468 nm, sifa ya LED za bluu zenye msingi wa InGaN. Nusu-upana dhaifu unaonyesha usawa mzuri wa rangi.
• 5. Taarifa ya Mitambo na Kifurushi 5.1 Vipimo vya Kifurushi Kifaa hiki kinafuata kiwango cha tasnia cha SMD. Vipimo muhimu ni pamoja na urefu wa mwili wa takriban 3.2 mm, upana wa 1.6 mm, na urefu wa 1.2 mm. Uvumilivu wote kwa kawaida ni ±0.1 mm. Ubunifu wa mtazamo wa upande humaanisha uso mkuu wa kutolea mwanga uko upande mdogo wa kifurushi.5.2 Mpangilio wa Pad ya PCB na Ubaguzi Muundo ulipendekezwa wa ardhi (ukubwa wa mguu) kwa ubunifu wa PCB umetolewa. Terminali ya cathode (hasi) kwa kawaida hutambuliwa na alama ya kuona kwenye kifurushi cha LED, kama vile mwanya, nukta ya kijani, au kona iliyokatwa. Silkscreen ya PCB inapaswa kuonyesha wazi ubaguzi ili kuzuia makosa ya usanikishaji. Ukubwa sahihi wa pad na nafasi ni muhimu kwa kufikia viunganisho vya kuuza vya kuaminika na kuzuia kujengwa kaburi wakati wa reflow.
• 6. Mwongozo wa Uuzaji na Usanikishaji 6.1 Profaili ya Uuzaji wa IR Reflow Kifaa hiki kimepimwa kwa michakato ya uuzaji isiyo na risasi (Pb-free). Profaili iliyopendekezwa inajumuisha eneo la joto la awali (150-200°C), kupanda kwa udhibiti, joto la kilele lisilozidi 260°C, na muda wa joto la kilele la sekunde 10 kiwango cha juu. Jumla ya mizunguko ya reflow inapaswa kuwa na kikomo cha mbili. Profaili hii inategemea viwango vya JEDEC ili kuhakikisha uadilifu wa kifurushi na viunganisho vya umeme vya kuaminika.6.2 Uhifadhi na Ushughulikiaji LED ni nyeti kwa unyevu (MSL 3). Wakati zimehifadhiwa kwenye mfuko wao wa asili uliofungwa wa kizuizi cha unyevu na dawa ya kukausha, zina maisha ya rafu ya mwaka mmoja kwa ≤30°C na ≤90% RH. Mara tu mfuko unapofunguliwa, vipengele vinapaswa kutumika ndani ya wiki moja chini ya hali ya mazingira ya ≤30°C na ≤60% RH. Ikiwa zimefichuliwa kwa muda mrefu, unyevu wa joto wa 60°C kwa angalau masaa 20 unahitajika kabla ya kuuza ili kuondoa unyevu uliokamatiwa na kuzuia "popcorning" (kupasuka kwa kifurushi wakati wa reflow).
• 6.3 Kusafisha Ikiwa usafishaji baada ya kuuza ni muhimu, vimumunyisho vya aina ya pombe tu kama vile isopropyl alcohol (IPA) au ethyl alcohol vinapaswa kutumika. LED inapaswa kuzamishwa kwenye joto la kawaida kwa chini ya dakika moja. Kemikali kali au zisizobainishwa zinaweza kuharibu lenzi ya epoxy au kifurushi.6.4 Tahadhari za Utoaji wa Umeme wa Tuli (ESD) LED hii ni nyeti kwa uharibifu kutoka kwa utoaji wa umeme wa tuli. Udhibiti sahihi wa ESD lazima uwe mahali wakati wa usindikaji na usanikishaji. Hii inajumuisha matumizi ya vituo vya kazi vilivyowekwa ardhini, mikanda ya mkono, mati ya sakafu ya conductive, na kifurushi cha kupinga tuli.
• 7. Taarifa ya Kifurushi na Uagizaji 7.1 Vipimo vya Tape na Reel Vipengele husambazwa kwenye tepi ya kubeba iliyochongwa na upana wa 8 mm. Tepi hiyo imejikunja kwenye reel ya kawaida ya kipenyo cha inchi 7 (178 mm). Kila reel ina vipande 3000. Tepi imefungwa na tepi ya kifuniko cha kinga. Kifurushi kinafuata viwango vya ANSI/EIA-481.7.2 Idadi ya Chini ya Uagizaji Kiwango cha kifurushi ni reel moja (vipande 3000). Kwa idadi chini ya reel kamili, kifurushi cha chini cha vipande 500 kinapatikana kwa hisa iliyobaki.
• 8. Vidokezo vya Utumizi na Mazingatio ya Ubunifu 8.1 Ubunifu wa Saketi ya Kiendeshi Daima tumia kiendeshi cha umeme thabiti au kizuizi cha umeme mfululizo na LED inapotumika kutoka kwa chanzo cha voltage. Thamani ya kizuizi inaweza kuhesabiwa kwa kutumia Sheria ya Ohm: R = (V_chanzo - VF_LED) / I_inayotaka. Kwa kuzingatia safu ya VF (2.8-3.8V), buni kwa hali mbaya zaidi ili kuhakikisha umeme hauzidi kamwe kiwango cha juu kabisa, hata na kifaa cha VF ya chini.8.2 Usimamizi wa Joto Ingawa mtawanyiko wa nguvu ni wa chini (76 mW), usimamizi bora wa joto bado ni muhimu kwa muda mrefu na kudumisha pato la mwanga. Hakikisha PCB ina eneo la kutosha la shaba linalounganishwa na pad ya joto ya LED (ikiwa inatumika) au pad za kuuza ili kuondoa joto. Kufanya kazi kwa joto la juu la mazingira au kwa umeme wa juu kabisa kutapunguza maisha ya kifaa.

8.3 Ujumuishaji wa Mwanga Profaili ya utoaji wa mtazamo wa upande ni bora kwa miongozo ya mwanga ya ukingo, uangazaji wa alama kwenye uso wima, au kutoa mwanga wa nyuma kwa funguo karibu na PCB. Fikiria pembe ya kuona ya digrii 130 wakati wa kubuni mabomba ya mwanga au vifaa vya kusambaza ili kuhakikisha uangazaji sawa wa eneo lengwa.

9. Ulinganisho wa Kiufundi na Tofauti Ikilinganishwa na SMD LED za mtazamo wa juu, toleo hili la mtazamo wa upande linatoa faida tofauti ya mitambo kwa miundo iliyofungwa na nafasi ambapo mwanga unahitaji kutolewa sambamba na ndege ya PCB. Matumizi ya chipu ya InGaN hutoa ufanisi wa juu na pato la bluu lenye mwangaza zaidi ikilinganishwa na teknolojia za zamani. Uwezo wake wa kufanana na IR reflow ya kawaida na kifurushi cha tepi-na-reel hufanya iwe na gharama nafuu kwa uzalishaji wa otomatiki wa wingi, na kuifanya iwe tofauti na LED zinazohitaji uuzaji wa mikono.

10. Maswali Yanayoulizwa Mara kwa Mara (FAQ) 10.1 Je, naweza kuendesha LED hii moja kwa moja kutoka kwa usambazaji wa 5V? Hapana. Kuiunganisha moja kwa moja kwa 5V kungesababisha umeme mwingi kupita, na kuharibu LED mara moja. Lazima daima utumie kizuizi cha umeme mfululizo au kiendeshi maalum cha LED cha umeme thabiti.

10.2 Je, ni tofauti gani kati ya wavelength ya kilele na wavelength kuu? Wavelength ya kilele (λP) ni wavelength ambayo pato la nguvu la wigo ni la juu kabisa. Wavelength kuu (λd) inatokana na kuratibu za rangi kwenye mchoro wa rangi wa CIE na inawakilisha rangi inayoonwa. Kwa chanzo cha rangi moja kama LED hii ya bluu, ziko karibu sana, lakini λd inafaa zaidi kwa ubainishaji wa rangi.

10.3 Kwa nini hali ya uhifadhi ni kali sana baada ya kufungua mfuko? Nyenzo za kifurushi cha epoxy zinaweza kukamata unyevu kutoka kwa hewa. Wakati wa mchakato wa joto la juu wa uuzaji wa reflow, unyevu huu uliofungwa unaweza kuyeyuka haraka, na kuunda shinikizo la ndani ambalo linaweza kupasua kifurushi ("popcorning"). Kiwango cha MSL 3 na utaratibu wa kupikia huzuia hali hii ya kushindwa.

11. Mfano wa Utumizi wa Vitendo Hali: Kubuni paneli ya dalili ya hali kwa router ya mtandao. Paneli ina nafasi ndogo, wima za alama za hali (Nguvu, Mtandao, Wi-Fi). LED ya mtazamo wa upande imewekwa kwenye PCB kuu nyuma ya kila nafasi. Pembe yake ya kuona ya digrii 130 inahakikisha alama inaangazwa sawasawa kutoka ndani ya nafasi. Mbunifu anachagua LED kutoka kwa bin sawa ya nguvu ya mwangaza (k.m., Bin Q) na bin ya voltage ya mbele (k.m., Bin D9) ili kuhakikisha taa zote za hali zina mwangaza na rangi sawa zinapoendeshwa na chanzo cha umeme sawa. Mpangilio wa PCB unafuata jiometri ya pad iliyopendekezwa, na nyumba ya usanikishaji hutumia profaili maalum ya reflow inayofuata JEDEC.

12. Kanuni ya Uendeshaji Hiki ni kifaa cha photoniki cha semiconductor. Kina msingi wa muundo mchanganyiko wa InGaN. Wakati voltage ya upendeleo ya mbele inatumika, elektroni na mashimo huingizwa kwenye eneo la kazi kutoka kwa tabaka za semiconductor za aina-n na aina-p, mtawaliwa. Wabebaji hawa wa malipo hujumuisha tena kwa mwangaza, na kutolea nishati kwa njia ya photon. Nishati maalum ya pengo la bendi ya nyenzo ya InGaN huamua wavelength ya mwanga unaotolewa, ambayo katika kesi hii iko katika wigo wa bluu (~468 nm). Lenzi ya epoxy hufunga chipu, hutoa kinga ya mitambo, na huunda boriti ya pato la mwanga.

13. Mienendo ya Teknolojia Teknolojia ya msingi ya LED za bluu, InGaN, ilikuwa maendeleo ya kuvunja ardhi katika taa ya hali imara, na kuwezesha LED nyeupe (kupitia ubadilishaji wa fosforasi) na maonyesho ya rangi kamili. Mienendo ya sasa katika teknolojia ya SMD LED inalenga kuongeza ufanisi wa mwangaza (pato zaidi la mwanga kwa watt), kuboresha fahirisi ya kuonyesha rangi (CRI) kwa LED nyeupe, kufikia uaminifu wa juu zaidi na maisha marefu zaidi, na kuwezesha ukubwa wa kifurushi kidogo zaidi kwa matumizi ya miniature sana. Maendeleo katika nyenzo za kifurushi pia yanalenga kusimamia joto bora na kutoa pembe pana zaidi za kuona au muundo wa boriti uliodhibitiwa zaidi.

. Performance Curve Analysis

Graphical data provides deeper insight into device behavior under varying conditions.

.1 Forward Current vs. Forward Voltage (I-V Curve)

The I-V characteristic is non-linear. The curve shows that a small increase in voltage beyond the turn-on threshold (~2.8V) causes a rapid increase in current. Therefore, LEDs must be driven by a current-limited source, not a constant voltage source, to prevent thermal runaway and destruction.

.2 Luminous Intensity vs. Forward Current

This curve demonstrates that light output is approximately proportional to forward current within the rated operating range. However, efficiency (lumens per watt) may decrease at very high currents due to increased heat generation.

.3 Spectral Distribution

The spectral output graph shows a single peak centered around 468 nm, characteristic of InGaN-based blue LEDs. The relatively narrow half-width indicates good color saturation.

. Mechanical and Package Information

.1 Package Dimensions

The device conforms to an industry-standard SMD footprint. Key dimensions include a body length of approximately 3.2 mm, a width of 1.6 mm, and a height of 1.2 mm. All tolerances are typically ±0.1 mm. The side-view design means the primary light-emitting surface is on the smaller side of the package.

.2 PCB Pad Layout and Polarity

A recommended land pattern (footprint) for PCB design is provided. The cathode (negative) terminal is typically identified by a visual marker on the LED package, such as a notch, green dot, or cut corner. The PCB silkscreen should clearly indicate polarity to prevent assembly errors. Proper pad size and spacing are critical for achieving reliable solder joints and preventing tombstoning during reflow.

. Soldering and Assembly Guidelines

.1 IR Reflow Soldering Profile

The device is rated for lead-free (Pb-free) soldering processes. The recommended profile includes a pre-heat zone (150-200°C), a controlled ramp-up, a peak temperature not exceeding 260°C, and a time at peak temperature of 10 seconds maximum. The total number of reflow cycles should be limited to two. This profile is based on JEDEC standards to ensure package integrity and reliable electrical connections.

.2 Storage and Handling

The LEDs are moisture-sensitive (MSL 3). When stored in their original sealed moisture-barrier bag with desiccant, they have a shelf life of one year at ≤30°C and ≤90% RH. Once the bag is opened, components should be used within one week under ambient conditions of ≤30°C and ≤60% RH. If exposed for longer, a bake-out at 60°C for at least 20 hours is required before soldering to remove absorbed moisture and prevent "popcorning" (package cracking during reflow).

.3 Cleaning

If post-solder cleaning is necessary, only alcohol-based solvents like isopropyl alcohol (IPA) or ethyl alcohol should be used. The LED should be immersed at room temperature for less than one minute. Harsh or unspecified chemicals can damage the epoxy lens or package.

.4 Electrostatic Discharge (ESD) Precautions

This LED is susceptible to damage from electrostatic discharge. Proper ESD controls must be in place during handling and assembly. This includes the use of grounded workstations, wrist straps, conductive floor mats, and anti-static packaging.

. Packaging and Ordering Information

.1 Tape and Reel Specifications

The components are supplied on embossed carrier tape with a width of 8 mm. The tape is wound on a standard 7-inch (178 mm) diameter reel. Each reel contains 3000 pieces. The tape is sealed with a protective cover tape. Packaging conforms to ANSI/EIA-481 standards.

.2 Minimum Order Quantities

The standard packing quantity is one reel (3000 pieces). For quantities less than a full reel, a minimum pack of 500 pieces is available for remainder stock.

. Application Notes and Design Considerations

.1 Driver Circuit Design

Always use a constant current driver or a current-limiting resistor in series with the LED when powered from a voltage source. The resistor value can be calculated using Ohm's Law: R = (V_source - VF_LED) / I_desired. Given the VF range (2.8-3.8V), design for the worst-case scenario to ensure the current never exceeds the absolute maximum rating, even with a low-VF device.

.2 Thermal Management

While the power dissipation is low (76 mW), effective thermal management is still important for longevity and maintaining light output. Ensure the PCB has adequate copper area connected to the LED's thermal pad (if applicable) or solder pads to conduct heat away. Operating at high ambient temperatures or at maximum current will reduce the device's lifetime.

.3 Optical Integration

The side-view emission profile is ideal for edge-lighting light guides, illuminating symbols on a vertical surface, or providing backlighting for keys adjacent to the PCB. Consider the 130-degree viewing angle when designing light pipes or diffusers to ensure even illumination of the target area.

. Technical Comparison and Differentiation

Compared to top-view SMD LEDs, this side-view variant offers a distinct mechanical advantage for space-constrained designs where light needs to be emitted parallel to the PCB plane. The use of an InGaN chip provides higher efficiency and brighter blue output compared to older technologies. Its compatibility with standard IR reflow and tape-and-reel packaging makes it cost-effective for automated, high-volume production, distinguishing it from LEDs requiring manual soldering.

. Frequently Asked Questions (FAQ)

.1 Can I drive this LED directly from a 5V supply?

No. Connecting it directly to 5V would cause excessive current to flow, destroying the LED instantly. You must always use a series current-limiting resistor or a dedicated constant-current LED driver.

.2 What is the difference between peak wavelength and dominant wavelength?

Peak wavelength (λP) is the wavelength at which the spectral power output is maximum. Dominant wavelength (λd) is derived from the color coordinates on the CIE chromaticity diagram and represents the perceived color. For a monochromatic source like this blue LED, they are very close, but λd is more relevant for color specification.

.3 Why is the storage condition so strict after opening the bag?

The epoxy packaging material can absorb moisture from the air. During the high-temperature reflow soldering process, this trapped moisture can vaporize rapidly, creating internal pressure that can crack the package ("popcorning"). The MSL 3 rating and baking procedure prevent this failure mode.

. Practical Application Example

Scenario: Designing a status indicator panel for a network router.The panel has small, vertical slots for status icons (Power, Internet, Wi-Fi). A side-view LED is mounted on the main PCB directly behind each slot. Its 130-degree viewing angle ensures the icon is evenly illuminated from within the slot. The designer selects LEDs from the same luminous intensity bin (e.g., Bin Q) and forward voltage bin (e.g., Bin D9) to guarantee all status lights have identical brightness and color when driven by a common current source. The PCB layout follows the recommended pad geometry, and the assembly house uses the specified JEDEC-compliant reflow profile.

. Operating Principle

This is a semiconductor photonic device. It is based on an InGaN heterostructure. When a forward bias voltage is applied, electrons and holes are injected into the active region from the n-type and p-type semiconductor layers, respectively. These charge carriers recombine radiatively, releasing energy in the form of photons. The specific bandgap energy of the InGaN material determines the wavelength of the emitted light, which in this case is in the blue spectrum (~468 nm). The epoxy lens encapsulates the chip, provides mechanical protection, and shapes the light output beam.

. Technology Trends

The underlying technology for blue LEDs, InGaN, was a groundbreaking development in solid-state lighting, enabling white LEDs (via phosphor conversion) and full-color displays. Current trends in SMD LED technology focus on increasing luminous efficacy (more light output per watt), improving color rendering index (CRI) for white LEDs, achieving higher reliability and longer lifetimes, and enabling even smaller package sizes for ultra-miniature applications. Advancements in packaging materials also aim to better manage heat and provide wider viewing angles or more controlled beam patterns.