PCB Capacitors: Tataiso e Feletseng ea Boenjiniere

Selelekela

Li-capacitor tsa PCB ke likarolo tsa motheo tse sa sebetseng tse etsang mesebetsi ea bohlokoa lipotolohong tsa sejoale-joale tsa elektroniki, ho kenyeletsoa polokelo ea matla, ho sefa phepelo ea motlakase, ho thibela lerata le tlhokomelo ea botšepehi ba lets'oao. Ha lipotoloho tsa dijithale tse lebelo le phahameng le lisebelisoa tse matla a phahameng li ntse li ata haholo, ho khetha li-capacitor tsa PCB tse loketseng ho fetohile tsebo ea bohlokoa bakeng sa ho rala lihlahisoa tsa elektroniki tse tšepahalang.

Tataiso ena e hlahloba mefuta ea li-capacitor tse sebelisoang likopanong tsa PCB, mekhoa ea khetho, lintlha tsa moralo, le mekhoa e tloaelehileng ea ho hlōleha eo baenjiniere ba kopanang le eona lits'ebetsong tse sebetsang.

PCB Capacitors ke eng?

Li-capacitor tsa PCB li sebetsa ka ho boloka matla a motlakase sebakeng sa motlakase pakeng tsa lipoleiti tsa conductive tse arohaneng ke thepa ea dielectric. Lits'ebetsong tsa PCB, likarolo tsena li sebetsa likarolo tse ngata:

• Ho thibela DC ha u ntse u fetisa matšoao a AC
• Ho na le maqhubu a motlakase a thellang ka har'a lisebelisoa tsa motlakase
• Ho fana ka litsela tse tlase-tlase bakeng sa lerata le phahameng-frequency

Poleloana "capacitor in PCB" ha e hatise litšobotsi tsa motlakase feela empa hape le lintlha tsa ts'ebetso ea 'mele ho kenyelletsa boholo ba sephutheloana, theknoloji e ntseng e eketseha, inductance ea parasitic (ESL), equivalent series resistance (ESR), le ts'ebetso ea mocheso.

Ho fapana le dikarolo tse arohaneng tsa laboratori, di-capacitor tsa PCB di tlameha ho amohela dithibelo tsa tlhahiso tse kang diprofaele tsa ho tjheseletsa hape , kgatello ya mechini nakong ya kopano , le meedi ya sebaka hodima diboto tse nang le batho ba bangata . Di-capacitor tsa sesebediswa sa ho kenya hodima metsi (SMD) di laola meralo ya sejwalejwale ka lebaka la kgato ya tsona e nyane le ho tsamaellana le ditshebetso tsa kopano tse iketsahallang.

Mefuta ea PCB Capacitors

1. Ceramic Capacitors

Li-capacitor tsa ceramic tse nang le mekhahlelo e mengata (MLCCs) li emela mofuta oa li-capacitor tse sebelisoang haholo likopanong tsa PCB ka lebaka la boholo ba tsona bo bonyenyane, litšenyehelo tse tlase, le ts'ebetso e ntle ea maqhubu a phahameng. Sehlopha sa thepa ea dielectric se khetholla botsitso ba mocheso le litšobotsi tsa bokhoni:

• C0G (NP0) dielectrics - Mamello e matla ka ± 30ppm/°C botsitso bakeng sa nako e nepahetseng le lits'ebetso tsa RF
• Mefuta ea X7R - Botsitso bo itekanetseng bo nang le phapang ea ± 15% ho tloha ho -55 ° C ho ea ho +125 ° C bakeng sa ho kopanya ka kakaretso
• K'hemik'hale ea Y5V - Matla a phahameng a matla a nang le mocheso o moholo le ho itšetleha ka motlakase bakeng sa lits'ebetso tse ngata tse sa hlokahaleng

Li-capacitor tsena tsa ceramic li sebetsa hantle haholo ho li-decoupling, bypass, le ho sefa lits'ebetso moo maqhubu a fetang megahertz tse 'maloa, e leng se etsang hore e be tsa bohlokoa haholo haufi le lipotoloho tse kopaneng le balaoli ba matla.

2. Li-Capacitors tsa Electrolytic

Aluminium le tantalum electrolytic capacitor li fana ka boleng bo phahameng ba matla ho tloha ho li-microfarad ho isa ho millifarads ka liphutheloana tse batlang li kopane. Li-electrolytics tsa aluminium ke likarolo tsa polarized tse atisang ho sebelisoa lits'ebetsong tsa matla a mangata a matla moo polokelo e kholo ea matla e hlokahalang ka litšenyehelo tse itekanetseng. Li-capacitor tsa Tantalum li fana ka ESR e tlase le karabelo e ntle ea frequency ho feta mefuta e fapaneng ea aluminium empa li na le litšenyehelo tse phahameng 'me li hloka ho fokotsoa ka hloko ho thibela ho hloleha ho hoholo. Mefuta ena ka bobeli e bonts'a ts'ebetso e itšetlehileng ka mocheso le nako e lekanyelitsoeng ea ts'ebetso e fokotsehang ka mocheso o phahameng.

3. Li-Capacitor tsa lifilimi

Li-capacitor tsa lifilimi li sebelisa li-dielectric tsa lifilimi tsa polasetiki tse kang polyester, polypropylene, kapa polycarbonate, tse fanang ka botsitso bo botle, tahlehelo e tlase ea tahlehelo, le litekanyetso tse phahameng tsa motlakase. Likarolo tsena li sebetsa hantle lipotolohong tsa phetolo ea matla, lits'ebetso tsa molumo, le khatello ea EMI moo thepa e tlase ea ho khopama le ho ipholisa e le ea bohlokoa. Leha ho le joalo, litekanyo tsa bona tse kholo tsa 'mele ha li bapisoa le mefuta e meng ea ceramic kapa ea electrolytic e fokotsa ho amoheloa ha meralo e haelloang ke sebaka.

4. Tantalum Capacitors

Li-capacitor tsa Tantalum li fana ka ts'ebetso e phahameng ea volumetric, ESR e tlase, le ts'ebetso e tsitsitseng ho pholletsa le mocheso, e etsa hore e tšoanelehe bakeng sa liporo tsa motlakase tse kopanetsoeng le lits'ebetso tse tlase. Mefuta e fapaneng ea polymer tantalum e ntlafatsa le ho feta ESR le boitšoaro ba ho buuoa. Leha ho le joalo, li hloka ho fokotseha ha matla a motlakase - hangata ho pota 50% - ho thibela ho hloleha le ho se mamelle maqhubu a inrush. Leha ho na le mefokolo ena, li-capacitor tsa tantalum li lula e le khetho e tšepahalang moo boholo, botsitso le botsitso li tlang pele molemong oa moralo oa PCB.

5. Li-Supercapacitor

Li-Supercapacitor li koala lekhalo pakeng tsa li-capacitor tse tloaelehileng le libeteri, li fana ka boleng ba capacitance ho tloha ho li-farad ho isa ho li-farad tse likete. Lisebelisoa tsena li sebeletsa mesebetsi ea matla a bekapo, tlatsetso ea hona joale e phahameng, le lits'ebetso tsa ho kotula matla moo ho hlokahalang lipotoloho tse potlakileng tsa ho ntša tjhaja. Likopanong tsa PCB, li-supercapacitor li hloka matlafatso ea mechini ka lebaka la boima ba tsona bo boholo 'me li ka hloka lisebelisoa tse inehetseng tsa ho kenya.

6. Li-Capacitor tse khethehileng tsa PCB

Li-capacitor tsa RF li na le inductance e tlase ea parasitic le mamello e tiileng bakeng sa tokiso ea maqhubu a maqhubu a phahameng, ha li-capacitor tse nang le matla a phahameng li kenyelletsa insulation e ntlafalitsoeng le litlhoko tsa sebaka sa creepage. Li-capacitor tsa polokeho tse thathamisitsoeng e le X-capacitor (line-to-line) le Y-capacitor (line-to-ground) li fihlela litekanyetso tsa taolo bakeng sa ho hatella tšitiso ea motlakase ha li ntse li thibela likotsi tsa ts'oenyeho lisebelisoa tse tsamaisoang ke AC.

SMD vs Through-Hole Capacitors ho PCB Assembly

Li-capacitor tsa theknoloji tse hokelang holim'a metsi li laola tlhahiso ea PCB ea sejoale-joale ka lebaka la ho lumellana ha tsona le lisebelisoa tse iketsang tsa ho khetha le ho beha, ho fokotseha ha leoto, le ts'ebetso e phahameng ea maqhubu a phahameng e bakoang ke bolelele bo bokhutšoanyane ba lead. Li-capacitor tsa electrolytic tsa ceramic, tantalum, le aluminium tsa boleng bo bonyenyane li fumaneha habonolo liphuthelong tsa SMD ho tloha ho 0201 (0.6mm × 0.3mm) ho isa boholong ba mabokose a maholo.

Li-capacitor tse phunyeletsang li boloka melemo lits'ebetsong tse hlokang litekanyetso tse phahameng tsa motlakase, boleng bo boholo ba capacitance, kapa likhokahano tse matla tsa mechini moo ho thothomela le potoloho ea mocheso li amehang. Likarolo tse nang le lead ea radial le axial li nolofatsa ts'ebetso ea prototyping le tokiso ha li ntse li fana ka matšoao a bonahalang a polarity mefuteng ea electrolytic le tantalum.

Mesebetsi ea Bohlokoa ea PCB Capacitors

1. Decoupling Capacitors

Li-capacitor tse arolang li thibela ho feto-fetoha ha motlakase lireing tsa phepelo ea motlakase tse bakoang ke li-transients tsa motlakase tse potlakileng tse tsoang lipotolohong tse kopantsoeng tsa dijithale. Li behiloe haufi le li-pin tsa motlakase tsa IC, li-capacitor tsena li fana ka libaka tsa polokelo ea matla tsa lehae tse arabelang ka potlako ho feta kamoo phepelo ea motlakase e ka fanang ka motlakase ka mekhoa ea PCB. Litekanyetso tse ngata tsa capacitor hangata li bapisoa ho sebetsana le mefuta e fapaneng ea maqhubu: litekanyetso tse kholo (1-10µF) li sebetsana le liphetoho tsa mojaro oa maqhubu a tlase ha li-ceramic tse nyane (0.01-0.1µF) li laola lerata la ho fetola maqhubu a phahameng.

2. Bypass Capacitors

Li-capacitor tsa Bypass li theha litsela tse tlase tsa AC ho ea fatše, li thibela lerata le phahameng hole le li-circuits tse bobebe. Le hoja hangata e sebelisoa ka ho fapanyetsana le li-capacitor tse kopanyang, lisebelisoa tsa bypass li lebisa ka ho khetheha phalliso ea lerata ho e-na le ho boloka matla. Ts'ebetsong e nepahetseng ea bypass e nahana ka makhetlo a mangata a capacitor 'me e tiisa hore inductance ea parasitic ha e sekisetse tshebetso.

3. Filtering Capacitors

Ho sefa li-capacitor tse boreleli tsa motlakase phepelong ea motlakase, ho fokotsa tšitiso ea motlakase, le ho theha marang-rang a resonant hammoho le li-inductors. ESR ea li-capacitor tse sefang e ama ka kotloloho boholo ba voltage ea ripple le ho felloa ke matla. Likopo li tloha ho li-filters tse bonolo tsa RC tse thibelang lerata le phahameng ho ea ho marang-rang a rarahaneng a LC a bōpang karabelo ea maqhubu lipotolohong tsa boemo ba matšoao.

4. Li-Capacitor tsa polokelo ea Matla

Li-capacitor tsa boleng bo boholo li thibela phepelo ea motlakase khahlano le litlhoko tsa mojaro oa nakoana le ho boloka botsitso ba motlakase nakong ea tšitiso e khutšoane. Li-converter tsa Buck le boost li itšetleha ka li-capacitor tsa ho kenya le ho tsoa ho laola maqhubu a maqhubu a hona joale, ha li-motor drive li sebelisa li-capacitor tsa DC-link ho monya matla a nchafatsang.

Mokhoa oa ho khetha li-capacitors tsa PCB

1. Lisebelisoa tsa motlakase

Khetho ea boleng ba bokhoni e qala ka litlhoko tsa potoloho empa e tlameha ho ikarabella bakeng sa mamello le lintlha tse nyenyefatsang:

• Tekanyo ea motlakase - E lokela ho feta matla a phahameng a ho sebetsa ka 50-100% margin bakeng sa ho tšepahala
• ESR le ESL - E bohlokoa lits'ebetsong tsa maqhubu a holimo moo likarolo tsa parasitic li laolang impedance
• Karabelo ea khafetsa - Maqhubu a ikemetseng a etsa qeto ea mofuta o sebetsang oa ts'ebetso
• DC leeme liphello - Li-ceramic capacitor li ka lahleheloa ke 50-80% ea matla a lekantsoeng tlas'a motlakase o sebelisitsoeng

2. Khetho ea Lintho le Dielectric

Khetho ea thepa ea dielectric e leka-lekanya matla a capacitance, botsitso ba mocheso, le coefficient ea voltage. X7R ceramic e fana ka ts'ebeliso e sebetsang bakeng sa lits'ebetso tse ngata tse nang le ± 15% capacitance phapang ho feta -55 ° C ho + 125 ° C, ha C0G e boloka botsitso ba ± 30ppm / ° C bakeng sa lipotoloho tse nepahetseng tsa nako. Y5V e fihlella katleho e kholo ea volumetric empa e na le tahlehelo e kholo ea bokhoni maemong a mocheso le tlas'a leeme la DC.

3. Mabaka a Tikoloho le a Tšepahalang

Mofuta oa mocheso o sebetsang o etsa qeto ea khetho ea thepa ea dielectric le litlhoko tsa ho fokotseha, ka li-capacitor tsa electrolytic tse amehang ka ho khetheha ho mocheso o phahameng o potlakisang moea oa electrolyte. Ho pepeseha ha mongobo ho ama ho lutla ha hona joale mefuteng e itseng ea dielectric, athe khatello ea mochini e tsoang ho board flexure e ka senya li-capacitor tsa ceramic.

4. Litšitiso tsa Tlhahiso ea SMT

Khetho ea boholo ba sephutheloana e ama tlhahiso ea kopano le ts'epahalo, e nang le likaroloana tse nyane joalo ka 0201 le 0402 tse hlokang taolo e matla ea ts'ebetso empa e nolofalletsa meralo e phahameng. Reflow soldering profiles e tlameha ho lula ka har'a litlhaloso tsa moetsi oa capacitor ho thibela ho phatloha ho MLCC kapa khatello ea khatello ea mefuta e tiisitsoeng ea electrolytic. Ho feto-fetoha ha boto nakong ea ho ts'oaroa ho emela sesosa se ka sehloohong sa ho phatloha ha ceramic capacitor.

Litaelo tsa sebopeho sa PCB Capacitor

Melao ea ho Beha Li-Capacitor tsa PCB

Li-decoupling capacitor li tlameha ho behoa haufi ka hohle kamoo ho ka khonehang ho lithakhisa tsa matla tsa IC tseo li li tšehetsang, ka sebaka se lekantsoeng ka limilimithara ho fokotsa loop inductance:

• Phetoho ea maqhubu a holimo - Beha mokatong o le mong oa boto joalo ka IC ka palo e fokolang ea lipalo tseleng ea hajoale
• Bokhoni ba bongata - Beha haufi le sehokelo sa motlakase bakeng sa polokelo ea matla e fokolang khafetsa
• Tsamaiso ea ho futhumatsa - Nahana ka ho qhala ha mocheso ho tsoa lits'ebetsong tse phahameng tsa ripple-current
• Khatello ea mechine - Qoba ho beoa haufi le mapheo a boto, masoba a holang, kapa libaka tse phahameng haholo

Ho tsamaisa le ho hokahanya

Litsela tse pharalletseng, tse khutšoane lipakeng tsa li-capacitor le lintlha tsa khokahano ea tsona li fokotsa letoto la inductance le theolang katleho ea maqhubu a holimo. Matla le likhokahano tsa fatše li lokela ho sebelisa li-vias tse ngata ho tsamaisana le litsela tsa hona joale le ho fokotsa ts'oaetso ka kakaretso. Li-capacitor tse fokotsang maqhubu a phahameng li rua molemo ho tsoa ho likhokahanyo tse otlolohileng ka-ka-pad ho lifofane tsa fatše, ho felisa bolelele ba ho latela ka botlalo.

Mokhoa oa ho bokella le ho khutlisa

Sebaka se haufi le sefofane se ama ts'ebetso ea capacitor ka ho fokotsa loop inductance le taolo e ntlafetseng ea mocheso. Li-capacitor tsa maqhubu a phahameng li lokela ho bua ka lifofane tsa fatše tse sa sitisoeng holim'a likarolo tse haufi, ka tlhokomelo e hlokolosi ho khutlisetsa litsela tsa morao-rao tse latelang tsela e fokolang haholo. Arola lifofane tse fatše li qobella ho khutlisa maqhubu litseleng tse telele, ho eketsa mahlaseli le ho fokotsa khatello ea lerata.

Mekhoa e Tloaelehileng ea ho hloleha ea PCB Capacitors

Ho hloleha ha Mechini

Ho phatloha ha Ceramic capacitor ho bakoa ke khatello ea maikutlo nakong ea kopano, ho ts'oaroa, kapa ho palama libaesekele tse futhumetseng, ho bonts'a matla a fokotsehileng kapa lipotoloho tse bulehileng tse felletseng. Ho hloleha ho bakoang ke ho kobeha ha boto ho feta moeli oa ho robeha ha 'mele oa ceramic, haholo-holo ho ama boholo ba mekotla e meholo le li-capacitor tse behiloeng haufi le mats'oao a boto. Tlhahlobo ea optical e ikemetseng ha se hangata e lemohang mapetsong, e leng ho etsang hore tlhahlobo ea ts'ebetso e be ea bohlokoa.

Ho senyeha ha Electrolytic

Li-electrolytic capacitor li hloleha ka lebaka la ho omella ha electrolyte mochesong o phahameng, butle-butle li eketsa ESR le ho fokotsa bokhoni ho fihlela ts'ebetso e oela ka tlase ho meeli e amohelehang:

• Reverse voltage - E ka baka ho phatloha ho hoholo kapa ho phatloha ho li-electrolytic tsa aluminium
• Mokotla o feteletseng - E hlahisa mocheso o ka hare o potlakisang botsofali
• Ho chesa ha Tantalum - Li-voltage transients li ka baka liphoso tse makatsang tse hlokang ho fokotsoa ka nepo

Overvoltage le Liphello tsa Leeme

Ho senyeha ha overvoltage ho phunyeletsa thepa ea dielectric, ho theha li-circuits tse khutšoanyane tse ka senyang likarolo tse potolohileng. DC bias effects in high-capacitance X5R le X7R MLCCs e ka fokotsa bokhoni bo sebetsang ka 50-80% ho voltage rated rated, e hlokang metsoako e tšoanang kapa ho fallela ho boholo ba linyeoe tse kholo ho boloka ts'ebetso tlas'a maemo a ts'ebetso.

Lisebelisoa tsa PCB Capacitors

• Lisebelisoa tsa puisano e itšetlehile haholo ka li-capacitor tsa PCB bakeng sa boemo ba matla, ho kopanya mats'oao, le ho tsamaisana ha RF ho pholletsa le mefuta e fapaneng ea maqhubu.
• Lisebelisoa tsa bongaka batla li-capacitor tse tšepahalang haholo tse kopanang le litekanyetso tse thata tsa polokeho bakeng sa lisebelisoa tse hokahantsoeng le mokuli le lits'ebetso tsa bohlokoa tsa bophelo.
• Mekhoa ea ho laola indasteri sebelisa li-capacitor ho li-drive tsa makoloi, li-converter tsa matla, le li-interface tsa sensor tse sebetsang ho pholletsa le mocheso o atolositsoeng.
• Mechini ea motlakase ea bareki e kenyelletsa bongata bo boholo ba li-capacitor tse nyane tsa ceramic tse nolofalletsang li-smartphones tsa komporo le lisebelisoa tse aparoang.
• Lisebelisoa tsa motlakase tsa koloi ea motlakase sebelisa li-capacitor tse khethehileng tsa high-voltage tse laolang phallo ea matla a kilowatt-level.

fihlela qeto e

Mathata a Tloaelehileng a PCB Capacitor ao re a Bonang

Ka lilemo tse ngata tsa ho tšehetsa kopano ea PCB ho Highleap Electronics, re fumane hore litaba tse ngata tse amanang le capacitor-tahlehelo ea DC bias ho MLCCs, ho hlokomolohuoa ho fokotseha, kapa taolo e sa lekaneng ea mechine e laolang khatello ea kelello-e ka thibeloa ka tlhokomelo ea pele ea moralo. Mathata a ho arohana ha maqhubu a phahameng hangata a bakoa ke likokoana-hloko tsa sebopeho ho e-na le capacitor ka boeona.

Kameho ea Miniaturization le Maqhubu a Phahameng

Ha meralo e ntse e fokola le ho potlaka, litekanyetso tsa setso ha li sa bonts'a boitšoaro ba 'nete ba PCB. Liphoso tseo re kopanang le tsona hangata li khutlela morao ka ho beoa, litlamorao tsa ESL/ESR, kapa litaba tse fokotsang mocheso ho fapana le ho ba le maemo a fosahetseng a matla.

Boleng ba Tšebelisano ea Pele ea Boenjiniere

Sehlopha sa rona se khothaletsa lipuisano tsa pele ho hlahloba khetho ea capacitor , sebaka le mokhoa oa ho e etsa. Ka ho netefatsa moralo, ho leka likhetho tsa sephutheloana, le ho ntlafatsa lits'ebetso tsa kopano nakong ea prototyping, re thusa ho thibela mathata pele ho tlhahiso le ho netefatsa ts'ebetso e tsitsitseng le ts'epo.