Jagorar Sarrafa LED SMD3528 - Girman 3.5x2.8mm - Takardar Fasaha ta Hausa

1. Bayanin Samfur Samfurin SMD3528 wani kayan LED ne da aka tsara don aikace-aikacen PCB masu yawan girma. Girman sa na 3.5mm x 2.8mm ya sa ya dace da hasken baya (backlighting), fitilun nuni, da hasken gabaɗaya inda sarari ya yi ƙarami. Babban fa'idar wannan kayan shine a cikin ƙaƙƙarfan rufin siliki, wanda ke ba da ingantaccen aikin haske. Duk da haka, wannan fasalin yana buƙatar tsarin sarrafa da hankali don hana lalata tsarin ciki mai laushi, gami da igiyoyin zinare da guntun LED (die).

2. Hatsarori na Sarrafa Samfuran SMD3528 Sarrafa mara kyau shine babban sanadin rashin aiki ga LED na SMD3528. Abin da aka rufe da siliki yana da laushi kuma yana iya lalacewa daga matsin jiki.

2.1 Sarrafa da Hannu Ba a ƙarfafa sarrafa LED kai tsaye da yatsa ba. Gumi da mai daga fata na iya gurɓata saman ruwan tabarau na siliki, wanda zai haifar da raguwar haske da rage fitar da haske. Bugu da ƙari, yin amfani da matsi da yatsa na iya murƙushe siliki, yana iya karya igiyoyin zinare na ciki ko lalata guntun LED kanta, wanda zai haifar da gazawar nan take (LED mara rai).

2.2 Sarrafa da Sandar Kama (Tweezers) Yin amfani da sandunan kama na yau da kullun don ɗaukar jikin LED kuma yana da matsala. Ƙarshen sanduna na iya huda ko canza siffar siliki mai laushi, yana haifar da lalacewar ciki iri ɗaya da sarrafa da hannu. Bugu da ƙari, sandunan ƙarfe na iya karce saman ruwan tabarau, canza tsarin fitar da haske da kusurwa.

2.3 Sarrafa da Na'urar Kama da Iska (Vacuum Pick-and-Place) Haɗawa ta atomatik ta amfani da bututun iska shine hanyar da aka ba da shawarar. Duk da haka, yana da mahimmanci cewa ƙarshen bututun iska yana da diamita mafi girma fiye da rami na ciki na fakitin LED. Bututun da ya yi ƙanƙanta zai matsa kai tsaye cikin siliki, yana aiki azaman ma'anar matsi mai ma'ana wanda zai iya yanke igiyoyin haɗin ko murƙushe guntun.

2.4 Sarrafa Bayan Siyarwa Bayan aiwatar da siyar da giciye, dole ne a sarrafa PCBs da ke ɗauke da LED na SMD3528 da hankali. Tsara allunan kai tsaye a saman juna na iya yin matsi akan kumburin LED. Wannan matsin zai iya haifar da damuwa na injina, wanda zai haifar da lahani ko gazawar nan take. Dole ne a kiyaye mafi ƙarancin tsari na tsaye na 2cm sama da kayan LED lokacin da ake tsara tarukan. Kada a sanya kayan kumfa kai tsaye akan LED, saboda matsin daga kumfa kuma zai iya haifar da lalacewa.

3. Hatsarin Danshi, Adanawa, da Gasawa LED na SMD3528 an rarraba shi azaman na'urar mai saurin danshi (MSD). Danshin da aka sha zai iya tafasa cikin sauri yayin aiwatar da siyar da giciye mai zafi, yana haifar da rabuwar ciki, tsagewa, ko "popcorning," wanda ke haifar da gazawa.

3.1 Matakin Hatsarin Danshi (MSL) Wannan samfurin ya bi ka'idar IPC/JEDEC J-STD-020C don rarrabuwar saurin danshi/siyar da giciye don kewayawan filastik. Dole ne masu amfani su koma ga takamaiman ƙimar MSL da aka bayar akan fakitin samfur ko takardar bayanai.

3.2 Yanayin Adanawa Fakitin da ba a buɗe ba: A adana a cikin yanayi mai zafi tsakanin 5°C da 30°C da zafi na dangi ƙasa da 85%. Fakitin da aka buɗe: Dole ne a adana kayan a cikin yanayi mai bushewa. Yanayin da aka ba da shawarar shine zafi tsakanin 5°C da 30°C tare da zafi na dangi ƙasa da 60%. Don mafi kyawun kariya bayan buɗewa, adana kayan a cikin akwati mai rufi tare da busassun abu ko a cikin kabad mai bushewa da iskar nitrogen.

3.3 Rayuwar Bayan Budewa Da zarar an buɗe jakar shinge na danshi na asali, yakamata a yi amfani da kayan cikin sa'o'i 12 idan ba a sarrafa yanayin adanawa ba (misali, ba a cikin kabad mai bushewa ba). Dole ne a duba katin nuna zafi a cikin jakar nan da nan bayan buɗewa don tabbatar da cewa zafin ciki bai wuce matakan aminci ba.

3.4 Bukatu da Hanyar Gasawa Ana buƙatar gasawa don cire danshin da aka sha idan: An cire kayan daga fakitin su na asali mai rufi kuma an fallasa su ga iskar yanayi fiye da ƙayyadaddun rayuwar bayan buɗewa. Katin nuna zafi ya nuna an wuce matakin zafi. Kayan da suka riga sun yi siyar da giciye ba sa buƙatar gasawa. Hanyar Gasawa: Ana iya gasa kayan akan reel ɗin su na asali. A gasa a zafin jiki na 60°C (±5°C) na tsawon awanni 24. Kada a wuce 60°C, saboda yanayin zafi mafi girma na iya lalata fakitin LED ko kayan. Bayan gasawa, dole ne a yi siyar da giciye na kayan cikin sa'a ɗaya ko kuma a mayar da su nan da nan cikin yanayin adanawa mai bushewa (RH 20%).

4. Jagororin Siyarwa da Tsaftacewa 4.1 Siyar da Giciye (Reflow Soldering) Bari LED ya sanyaya zuwa zafin daki da kansu bayan aiwatar da siyar da giciye kafin kowane sarrafa ko tsaftacewa na gaba. Bincika haɗin giciye don daidaito. Giciye ya kamata ya nuna cikakken siffar siyar da giciye tare da santsi, sheki, da ƙaramin ramuka idan aka daga gefen PCB. 4.2 Tsaftacewa Bayan Siyarwa Ana ba da shawarar tsaftace PCB bayan siyarwa don cire ragowar flux. Abin da aka ba da shawarar: Yi amfani da flux mai narkewa da ruwa kuma a tsaftace shi da ruwa maras ions ko takamaiman mai tsaftacewa na ruwa, sannan a bushe. Ana iya amfani da barasa na isopropyl (IPA) idan ya cancanta. Ba a ba da shawarar ba / An hana: Kada a yi amfani da tsaftacewa ta ultrasonic. Girgizar mitar mafi girma na iya haifar da ƙananan tsagewa a cikin guntun LED ko igiyoyin haɗin. Kada a tsaftace PCBs da aka haɗa da ruwa mai sauƙi, saboda yana da wahala a bushe gabaɗaya kuma zai iya haifar da lalata gubar kayan. A guji ƙarfi masu narkewa na kwayoyin halitta kamar acetone, toluene, ko lacquer thinner. Waɗannan sinadarai na iya kai hari da lalata kayan ruwan tabarau na siliki, haifar da hazo, tsagewa, ko narkewa. Kada a taɓa yin amfani da masu tsaftacewa na sinadarai da ba a bayyana ba. Idan tsaftacewa da ruwa ba za a iya kaucewa ba, dole ne a bushe dukan tarin PCB gabaɗaya, yana iya buƙatar gasa mai ƙarancin zafi (misali, 60°C) don cire duk danshi kafin ƙarin sarrafa ko amfani.

5. Kariya daga Wutar Lantarki (ESD) LEDs na'urori ne na semiconductor kuma suna da saurin lalacewa daga fitar da wutar lantarki. Fararen, kore, shuɗi, da LED masu shuɗi suna da hankali musamman saboda abun da ke cikin kayan semiconductor.

5.1 Tushen Wutar Lantarki (ESD) Ana iya samar da ESD ta hanyoyi daban-daban: Gogayya: Haɗuwa da rabuwa na kayan daban-daban (misali, tirelolin filastik, tufafi, fakitin). Ƙarfafawa: Abu mai caji da aka kawo kusa da saman mai ɗaukar wuta zai iya haifar da caji.

5.2 Matakan Kariya Cikakken shirin sarrafa ESD yana da mahimmanci a yankin sarrafawa: Yi amfani da tashoshin aiki masu ƙasa tare da tabarmi masu ɗaukar wuta. Dole ne duk ma'aikata su sanya madaurin wuyan hannu masu ƙasa da suka dace. Yi amfani da kwantena, tireloli, da jakunkuna masu ɗaukar wuta don adanawa da jigilar kayan. Kiyaye yanayi mai sarrafawa tare da zafi sama da 40% RH idan zai yiwu, saboda yawan zafi yana rage tarin caji. Sarrafa kayan kawai a wuraren aiki masu aminci na ESD da aka keɓe.

6. Tunani game da Sarrafa Zafi Yayin da cikakken takardar da aka fitar ba ta yi cikakken bayani game da takamaiman ƙimar juriya na zafi ba, ingantaccen sarrafa zafi yana da mahimmanci ga aikin LED da tsawon rai. Fakitin SMD3528 yana watsar da zafi da farko ta hanyar fakitin giciye zuwa cikin PCB.

6.1 Zanen PCB don Sanyaya Zafi Don ƙara tsawon rai da kiyaye ingantaccen fitar da haske: Yi amfani da PCB tare da isasshen ɗaukar zafi. Ana ba da shawarar PCB na ƙarfe-core (MCPCBs) ko allunan da ke da jiragen tagulla masu kauri don aikace-aikacen ƙarfi mai ƙarfi ko yawan girma. Zana fakitin ƙafar PCB tare da fakitin taimakon zafi da aka haɗa zuwa manyan yankuna na tagulla ko takamaiman ramukan zafi waɗanda ke canja wurin zafi zuwa cikin sassa ko na baya na sanyaya zafi. Tabbatar da ingancin haɗin giciye yana da girma, saboda giciye shine farkon hanyar sadarwa ta zafi tsakanin LED da allon. 6.2 Tasirin Zafin Jiki Babban zafin haɗuwa yana haifar da: Hanzarta raguwar lumen (rage fitar da haske akan lokaci). Canjin launi, musamman ga fararen LED. Rage tsawon lokacin aiki. Ƙara ƙarfin gaba. Masu zane yakamata su koma takardar bayanai na takamaiman samfur don lanƙwasa lanƙwasa da matsakaicin ƙimar zafin haɗuwa.

• 7. Siffofin Sanyaya Zafi na Siyar da Giciye don Jerin 3528 Siffar siyar da giciye maras gubar ta yau da kullun tana dacewa. Muhimman sigogi don sarrafawa sun haɗa da: Dumama/Ramp: Matsakaicin matakin ramp (yawanci 1-3°C/daƙiƙa) don rage girgizar zafi. Yankin Jiƙa: Yana ba da damar dukan tarawa da kayan su kai zafin jiki ɗaya kuma yana kunna flux. Yankin Siyar da Giciye: Dole ne matsakaicin zafin jiki ya yi yawa don tabbatar da narkewar giciye da kyau amma bai kamata ya wuce matsakaicin juriya na zafi na fakitin LED ba (tuntubi takardar bayanai, yawanci kusan 260°C na 'yan daƙiƙo'i). Sanyaya: Matakin sanyaya mai sarrafawa yana taimakawa samar da haɗin giciye mai aminci. Yana da mahimmanci a yi bayanin firinta tare da ainihin PCBs da kayan don tabbatar da cewa LED ba su fuskanci yanayin zafi fiye da ƙayyadaddun su ba.8. Bayanan Aikace-aikace da Tunani na Zane 8.1 Aikace-aikace na Yau da Kullun Ana amfani da SMD3528 sosai a cikin: Rukunin hasken baya na nuni na LCD (BLUs). Hasken ƙwaƙwalwar gine-gine. Hasken ciki na mota. Alamomin matsayin na'urorin lantarki na masu amfani. Alamomi da hasken ado. 8.2 Zanen Kewayawa (Circuit) Koyaushe ku tuka LED tare da tushen kwanon yau da kullun, ba ƙarfin wutar lantarki ba. Resistor mai iyakancewa yana wajibi ne lokacin amfani da tushen wutar lantarki. Dole ne a bi ƙarfin gaba (If) da ƙaƙƙarfan kamar yadda aka ƙayyade a cikin takardar bayanai don hana yawan zafi da saurin lalacewa. 8.3 Zanen Hasken (Optical) Ruwan tabarau na siliki yana ba da kusurwar kallo ta yau da kullun. Don takamaiman tsarin katako, ƙila a buƙaci na'urorin gani na biyu (masu haskakawa, masu watsawa, ko ruwan tabarau na waje). Guji haɗuwa ta injina tsakanin na'urorin gani na biyu da kumburin LED don hana damuwa.
• 9. Binciken Rashin Aiki da Magance Matsaloli Yanayin gazawar na yau da kullun da tushen tushensu sun haɗa da: LED mara rai (Babu Hasken): Yawancin lokaci ana haifar da lalacewar ESD, karyewar igiyoyin haɗin daga damuwa na injina (sarrafawa, tsarawa), ko karyewar guntun. Ragewar Fitar da Hasken: Zai iya haifar da gurɓatar ruwan tabarau na siliki, yawan zafin haɗuwa, ko gazawar haɗin giciye wanda ke haifar da rashin ingantaccen canja wurin zafi. Aiki na Tsaka-tsaki: Yana iya nuna tsagewar haɗin giciye, igiyar haɗin da ta lalace tana yin haɗuwa na tsaka-tsaki, ko lalacewar ESD. Canjin Launi: An haifar da shi da farko ta hanyar aiki na tsawon lokaci a yanayin zafi mai girma, tuƙi wutar lantarki fiye da ƙayyadaddun, ko lalacewar phosphor (a cikin fararen LED). Bin jagororin sarrafa, adanawa, siyarwa, da zane a cikin wannan takarda shine mafi ingantaccen matakin rigakafi.Components must be stored in a dry environment. The recommended condition is temperature between 5\u00b0C and 30\u00b0C with relative humidity below 60%. For optimal protection after opening, store components in a sealed container with desiccant or in a nitrogen-purged dry cabinet.

.3 Floor Life

Once the original moisture barrier bag is opened, the components should be used within 12 hours if the storage environment is not controlled (e.g., not in a dry cabinet). The humidity indicator card inside the bag must be checked immediately upon opening to verify the internal humidity has not exceeded safe levels.

.4 Baking Requirements and Procedure

Baking is required to remove absorbed moisture if:

1. The components have been removed from their original vacuum-sealed packaging and exposed to ambient air for longer than the specified floor life.
2. The humidity indicator card shows the humidity level has been exceeded.

Components that have already undergone reflow soldering do not require baking.

Baking Procedure:

1. Components can be baked on their original reel.
2. Bake at a temperature of 60\u00b0C (\u00b15\u00b0C) for 24 hours.
3. Do not exceed 60\u00b0C, as higher temperatures may damage the LED packaging or materials.
4. After baking, components must be reflow soldered within one hour or immediately placed back into a dry storage environment (RH<%).

. Soldering and Cleaning Guidelines

.1 Reflow Soldering

Allow the LED to cool down to room temperature naturally after the reflow process before any subsequent handling or cleaning. Inspect the solder joints for consistency. The solder should show a complete reflow profile with a smooth, shiny appearance and minimal voids when viewed from the side of the PCB.

.2 Post-Soldering Cleaning

Cleaning the PCB after soldering is recommended to remove flux residues.

• Recommended:Use water-soluble flux and clean with deionized water or a specified aqueous cleaner, followed by drying. Isopropyl alcohol (IPA) can also be used if necessary.
• Not Recommended / Prohibited:
  • Do notuse ultrasonic cleaning. The high-frequency vibrations can cause micro-cracks in the LED chip or wire bonds.
  • Do notclean assembled PCBs with plain water, as it is difficult to dry completely and can lead to oxidation of the component leads.
  • Avoidstrong organic solvents such as acetone, toluene, or lacquer thinner. These chemicals can attack and degrade the silicone lens material, causing clouding, cracking, or dissolution.
  • Never use unspecified chemical cleaners.

If water cleaning is unavoidable, the entire PCB assembly must be thoroughly dried, potentially requiring a low-temperature bake (e.g., 60\u00b0C) to remove all moisture before further processing or use.

. ESD (Electrostatic Discharge) Protection

LEDs are semiconductor devices and are highly susceptible to damage from electrostatic discharge. White, green, blue, and purple LEDs are particularly sensitive due to their semiconductor material composition.

.1 Sources of ESD

ESD can be generated through various means:

• Friction:Contact and separation of dissimilar materials (e.g., plastic trays, clothing, packaging).
• Induction:A charged object brought near a conductive surface can induce a charge.

.2 Protection Measures

A comprehensive ESD control program is essential in the handling area:

• Use grounded workstations with conductive mats.
• All personnel must wear properly grounded wrist straps.
• Use conductive containers, trays, and bags for storage and transport of components.
• Maintain a controlled environment with humidity above 40% RH if possible, as higher humidity reduces static charge buildup.
• Handle components only at designated ESD-safe work areas.

. Thermal Management Considerations

While the provided document excerpt does not detail specific thermal resistance values, effective thermal management is critical for LED performance and longevity. The SMD3528 package dissipates heat primarily through its solder pads into the PCB.

.1 PCB Design for Heat Sinking

To maximize lifespan and maintain stable light output:\p>

• Use a PCB with adequate thermal conductivity. Metal-core PCBs (MCPCBs) or boards with thick copper planes are highly recommended for high-power or high-density applications.
• Design the PCB footprint with thermal relief pads connected to large copper areas or dedicated thermal vias that transfer heat to inner layers or a backside heat sink.
• Ensure the solder joint integrity is high, as the solder is the primary thermal interface between the LED and the board.

.2 Impact of Temperature

High junction temperature leads to:

• Accelerated lumen depreciation (reduced light output over time).
• Color shift, especially for white LEDs.
• Reduced operational lifetime.
• Increased forward voltage.

Designers should refer to the product's specific datasheet for derating curves and maximum junction temperature ratings.

. Reflow Soldering Profile Characteristics for 3528 Series

A standard lead-free reflow profile is typically suitable. Key parameters to control include:

• Preheat/Ramp:A gradual ramp rate (typically 1-3\u00b0C/second) to minimize thermal shock.
• Soak Zone:Allows the entire assembly and components to reach a uniform temperature and activates the flux.
• Reflow Zone:The peak temperature must be high enough to ensure proper solder melting but must not exceed the maximum temperature tolerance of the LED package (consult datasheet, typically around 260\u00b0C for a few seconds).
• Cooling:A controlled cool-down phase helps form reliable solder joints.

It is crucial to profile the oven with actual PCBs and components to ensure the LEDs do not experience temperatures beyond their specification.

. Application Notes and Design Considerations

.1 Typical Applications

The SMD3528 is widely used in:

• LCD display backlighting units (BLUs).
• Architectural accent lighting.
• Automotive interior lighting.
• Consumer electronics status indicators.
• Signage and decorative lighting.

.2 Circuit Design

Always drive LEDs with a constant current source, not a constant voltage. A current-limiting resistor is mandatory when using a voltage source. The forward current (If) must be strictly adhered to as specified in the datasheet to prevent overheating and rapid degradation.

.3 Optical Design

The silicone lens provides a typical viewing angle. For specific beam patterns, secondary optics (reflectors, diffusers, or external lenses) may be required. Avoid mechanical contact between secondary optics and the LED dome to prevent stress.

. Failure Analysis and Troubleshooting

Common failure modes and their likely root causes include:

• Dead LED (No Light):Often caused by ESD damage, broken wire bonds from mechanical stress (handling, stacking), or chip fracture.
• Diminished Light Output:Can result from silicone lens contamination, excessive junction temperature, or solder joint failure leading to poor heat transfer.
• Intermittent Operation:May indicate a cracked solder joint, a damaged wire bond making intermittent contact, or ESD-induced latent damage.
• Color Shift:Primarily caused by prolonged operation at high temperatures, driving current beyond specification, or degradation of the phosphor (in white LEDs).

Adherence to the handling, storage, soldering, and design guidelines in this document is the most effective preventative measure.