PCB Capacitors: Yakazara Injiniya Guide

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MaPCB capacitors zvinhu zvakakosha zvinoitwa nemagetsi emazuva ano, zvinosanganisira kuchengetedza simba, kusefa magetsi, kudzvinyirira ruzha, uye kuchengetedza kuvimbika kwemasaini. Sezvo madhijitari edhijitari anomhanya zvakanyanya uye zvishandiso zvine simba rakawanda zvichiwedzera kuwanda, kusarudza maPCB capacitors akakodzera kwashanduka kuita hunyanzvi hwakakosha hwekugadzira zvigadzirwa zvemagetsi zvinovimbika.

Gwaro iri rinoongorora mhando dzemacapacitor anoshandiswa muPCB magungano, nzira dzekusarudza, kufunga kwemagadzirirwo, uye nzira dzakajairwa dzekutadza dzinosangana nemainjiniya mumashandisirwo anoshanda.

Chii chinonzi PCB Capacitors?

PCB capacitors inoshanda nekuchengetedza simba remagetsi mumunda wemagetsi pakati pemahwendefa e conductive akaparadzaniswa nedielectric material. MuPCB maapplication, izvi zvikamu zvinoshanda akawanda mabasa:

• Kuvhara DC paunenge uchipfuura masaini eAC
• Smoothing voltage ripples mumagetsi emagetsi
• Kupa yakaderera-impedance nzira dzepamusoro-frequency ruzha

Izwi rekuti "capacitor muPCB" rinosimbisa kwete maitiro emagetsi chete asiwo maitiro ekuita zvemuviri anosanganisira saizi yepasuru, tekinoroji yekukwira, parasitic inductance (ESL), yakaenzana nhevedzano kuramba (ESR), uye kupisa kwekuita.

Kusiyana nezvikamu zvakasiyana zvemarabhoritari, maPCB capacitors anofanira kugamuchira zvipingamupinyi zvekugadzira zvakaita se reflow soldering profiles , mechanical stress panguva yekuunganidza , uye nzvimbo dzakaganhurirwa pamapuranga ane vanhu vakawanda . MaSMD capacitors anonyanya kuumba magadzirirwo emazuva ano nekuda kwesimba rawo uye kuenderana kwawo nemaitiro ekuunganidza otomatiki.

Mhando dzePCB Capacitors

1. Ceramic Capacitors

Macapacitor eceramic akawanda (MLCCs) ndiwo anonyanya kushandiswa muPCB assemblies nekuda kwehukuru hwawo hudiki, mutengo wakaderera, uye mashandiro akanaka kwazvo e-frequency. Kupatsanurwa kwezvinhu zve dielectric kunosarudza kugadzikana kwetembiricha uye hunhu hwe capacitance:

• C0G (NP0) dielectrics -Kushivirira kwakasimba ne ± 30ppm/°C kugadzikana kwekuita nguva chaiyo uye mashandisirwo eRF.
• X7R maitiro - Kugadzikana kuri pakati nepakati ne ± 15% capacitance musiyano kubva -55 ° C kusvika + 125 ° C yezvakajairwa-chinangwa kubvisa
• Y5V chemistry - Yakakwira capacitance density ine yakakosha tembiricha uye kutsamira kwevoltage kune isiri-yakakosha yakawanda maapplication

Aya maceramic capacitors anokunda mukubvisa, kubvongodza, uye kusefa maapplication uko ma frequency anopfuura akati wandei megahertz, zvichiita kuti ive yakakosha padhuze nemasekete akabatanidzwa uye magetsi ekudzora.

2. Electrolytic Capacitors

Aluminium uye tantalum electrolytic capacitors inopa yakakwira capacitance kukosha kubva kumamicrofarad kusvika kumamilifaradhi mumapakeji akati wandei. Aluminium electrolytics inhengo dzepolarized dzinowanzoshandiswa mumagetsi ekupa yakawanda capacitance application uko hombe yekuchengetedza simba inodiwa nemutengo wakaderera. Tantalum capacitors inopa yakaderera ESR uye iri nani frequency mhinduro pane aruminiyamu akasiyana asi inotakura yakakwira mutengo uye inoda kungwarira voltage derating kudzivirira kutadza kunotyisa. Mhando dzose dziri mbiri dzinoratidza tembiricha-inotsamira kuita uye inogumira kushanda kweupenyu inodzikira patembiricha yakakwira.

3. Mafirimu Capacitors

Mafirimu capacitor anoshandisa epurasitiki firimu dielectrics senge polyester, polypropylene, kana polycarbonate, inopa kugadzikana kwakanyanya, kuderera kurasikirwa tangent, uye yakakwirira voltage ratings. Izvi zvikamu zvinoita zvakanaka mumagetsi ekushandura maseketi, maodhiyo maapplication, uye EMI kudzvanya uko kuderera kwakadzika uye kuzviporesa zvivakwa zvinokosheswa. Nekudaro, hukuru hwavo hwemuviri zvichienzaniswa neceramic kana electrolytic dzimwe nzira dzinodzikamisa kugamuchirwa munzvimbo-inomanikidzwa dhizaini.

4. Tantalum Capacitors

Tantalum capacitors inopa yakakwira volumetric kunyatsoita, yakaderera ESR, uye yakagadzikana kuita pane tembiricha, ichiita kuti ive yakakodzera kune compact magetsi njanji uye yakaderera-ripple application. Polymer tantalum akasiyana anovandudza ESR uye maitiro ekuvhiya. Nekudaro, ivo vanoda yakasimba voltage derating - kazhinji inotenderedza 50% - kudzivirira kutadza uye isinga shivirire inrush currents. Kunyangwe izvi zvisingakwanisi, tantalum capacitors inoramba iri sarudzo yakavimbika uko saizi, kugadzikana, uye kusimba kuri pamberi muPCB dhizaini.

5. Supercapacitors

MaSupercapacitor anovhara musiyano uripo pakati pemacapacitor echinyakare nemabhatiri, zvichipa huwandu hwe capacitance hunotangira pafarads kusvika kuzviuru zvefarads. Midziyo iyi inoshanda pakuchengetedza simba, kuwedzera simba remagetsi, uye kuunganidza simba uko kunodiwa nekukurumidza. PaPCB assemblies, masupercapacitor anoda kusimbiswa kwemuchina nekuda kwehukuru hwawo uye angangoda hardware yakatsaurirwa yekumisikidza.

6. Specialized PCB Capacitors

RF capacitors inoratidzira yakaderera parasitic inductance uye yakasimba kushivirira kune yakakwira-frequency wedunhu tuning, nepo yakakwira-voltage capacitor ichibatanidza yakawedzera insulation uye creepage kureba zvinodiwa. Chengetedzo macapacitor akaiswa seX-capacitor (mutsara-ku-mutsara) uye Y-capacitor (mutsara-kusvika-pasi) inosangana nemirairo yekudzvanya kukanganiswa kwemagetsi uku ichidzivirira njodzi dzinovhundutsa mumidziyo ine simba reAC.

SMD vs Kuburikidza neHole Capacitors muPCB Gungano

Ma capacitor etekinoroji anoiswa pamusoro pevhu ndiwo anonyanya kugadzirwa kwePCB dzemazuva ano nekuda kwekushanda kwawo nemidziyo yekusarudza otomatiki, kuderera kwetsoka, uye kushanda kwepamusoro-soro kunokonzerwa nekureba kwelead kupfupi. Ma capacitor e electrolytic eCeramic, tantalum, uye aluminium electrolytic capacitors anowanikwa zviri nyore mumapakeji eSMD kubva pa0201 (0.6mm × 0.3mm) kusvika kuhukuru hwemakesi makuru.

Ma capacitor anoburitswa mugomba rimwe nerimwe anoramba aine zvakanakira mukushandiswa kunoda ma voltage ratings epamusoro, capacitance values ​​makuru, kana kubatanidza kwakasimba kwemakanika uko kunonyanya kukonzera kudedera ne thermal cycling. Zvikamu zve radial ne axial lead zvinorerutsa mashandiro e prototyping nekugadzirisa uku zvichipa polarity markings inooneka pamhando dze electrolytic ne tantalum.

Akakosha Mabasa ePCB Capacitors

1. Decoupling Capacitors

Ma capacitor anobvisa magetsi anoderedza kushanduka kwemagetsi pamagetsi anokonzerwa nekufamba kwenguva refu kubva kuma digital integrated circuits. Akaiswa pedyo ne IC power pins, ma capacitor aya anopa nzvimbo dzesimba dzinoita basa nekukurumidza kupfuura simba guru rinogona kupa magetsi kuburikidza nePCB traces. Ma capacitor akawanda anowanzo enderana kuti agadzirise ma frequency ranges akasiyana: ma larger values ​​(1-10µF) anobata shanduko dze low-frequency load load ukuwo ceramics diki (0.01-0.1µF) dzichibata ruzha rwe high-frequency switching.

2. Bypass Capacitors

Bypass capacitors inogadzira yakaderera-impedance AC nzira kuenda pasi, ichivharira yakakwira-frequency ruzha kure neanonzwira edunhu node. Nepo ichiwanzo shandiswa kuchinjana ne decoupling capacitors, bypass application inonangana neruzha diversion pane kuchengetedza simba. Kuitwa kwakaringana bypass kunotarisa iyo capacitor's self-resonant frequency uye inova nechokwadi chekuti parasitic inductance haikanganisi kuita.

3. Kusefa Capacitors

Kusefa capacitors anotsvedzerera voltage ripples mumagetsi emagetsi, attenuate electromagnetic kupindira, uye kugadzira resonant network yakabatana nemainductors. Iyo ESR yekusefa capacitors inokanganisa zvakananga ripple voltage magnitude uye kupera simba. Zvishandiso zvinotangira kubva nyore RC mafirita anovharira yakakwirira-frequency ruzha kune yakaoma LC network inoumba frequency mhinduro mumasaini ekugadzirisa maseketi.

4. Energy Storage Capacitors

Huru-value capacitors buffer magetsi emagetsi zvichipesana neinotakura mitoro zvinodiwa uye inochengetedza kugadzikana kwevoltage panguva yekuvhiringwa kwenguva pfupi. Buck uye boost converters vanovimba nekupinza uye kubuda capacitors kubata pulsed ikozvino waveforms, nepo madhiraivha emotokari anoshandisa DC-link capacitor kutora simba rekuvandudza.

Maitiro ekusarudza PCB Capacitors

1. Magetsi Parameter

Capacitance kukosha kusarudzwa kunotanga nezvido zvedunhu asi inofanirwa kuzvidavirira nekushivirira uye zvinodzikisira zvinhu:

• Voltage chiyero -Inofanirwa kudarika yakanyanya kushanda voltage ne50-100% margin yekuvimbika
• ESR uye ESL -Yakakosha mune yakakwira-frequency application uko parasitic zvinhu zvinotonga impedance
• Kupindura kweruzhinji -Self-resonant frequency inosarudza inoshanda renji rekushandisa
• DC bias effects - Ceramic capacitors inogona kurasikirwa ne50-80% yeyakayerwa capacitance pasi pemhepo inoshandiswa

2. Zvinhu uye Dielectric Selection

Dielectric zvinhu sarudzo inoyera capacitance density, kugadzikana kwetembiricha, uye voltage coefficient. X7R ceramic inopa kuwirirana kunoshanda kune akawanda maapplication ane ± 15% capacitance musiyano pamusoro -55 ° C kusvika +125 ° C, nepo C0G inochengetedza ± 30ppm/ ° C kugadzikana kwemaseketi enguva chaiyo. Y5V inowana hukuru hwevhoriyamu kunyatsoshanda asi inotambura kurasikirwa kwakakura kwehunyanzvi pakupisa kwakanyanya uye pasi peDC bias.

3. Zvakatipoteredza uye Kuvimbika Zvinhu

Inoshanda tembiricha renji inotemesa dielectric zvinhu kusarudzwa uye kuderera zvinodiwa, ine electrolytic capacitor inonyanya kunzwira kune yakakwira tembiricha inomhanyisa evaporation ye electrolyte. Humidity exposure inokanganisa kuvuza ikozvino mune mamwe marudzi edielectric, nepo mechanic stress kubva kubhodhi flexure inogona kupaza ceramic capacitors.

4. SMT Manufacturing Constraints

Sarudzo yehukuru hwepakeji inokanganisa goho regungano uye kuvimbika, iine zvinhu zvidiki senge 0201 uye 0402 inoda kusimba kwekudzora maitiro asi ichigonesa yakakwirira density marongero. Reflow soldering thermal profiles inofanirwa kuramba iri mukati me capacitor mugadziri akatemerwa kudzivirira kupaza muMLCCs kana kumanikidza kuvaka muakavharirwa electrolytic mhando. Board flexure panguva yekubata inomiririra chikonzero chekutanga checeramic capacitor kupaza.

PCB Capacitor Layout Guidelines

Kuisa Mitemo yePCB Capacitors

Decoupling capacitor inofanirwa kuiswa padyo nepazvinobvira kune IC magetsi mapini avanotsigira, ane madaro akayerwa mumamirimita kudzikisa loop inductance:

• High-frequency bypass -Isa pane imwechete bhodhi layer seIC ine zvishoma kuburikidza nekuverenga munzira yazvino
• Bulk capacitance -Inzvimbo padyo nemagetsi ekubatanidza yekubatanidza kune yakaderera-frequency simba rekuchengetedza
• Thermal manejimendi - Funga nezvekupisa kupisa kubva kune yakakwirira-ripple-ikozvino maapplication
• Kunetseka kwechimiro -Dzivisa kuiswa padyo nebhodhi, maburi ekukwira, kana nzvimbo dzakakwirira-flex

Routing uye Connection

Yakafara, pfupi pfupi pakati pe capacitor nenzvimbo dzadzo dzekubatanidza inoderedza nhevedzano inductance iyo inoderedza kushanda kwepamusoro-frequency. Simba nevhu zvinongedzo zvinofanirwa kushandisa nzira dzakawanda kuti dzienderane nzira dzazvino uye kudzikisira zvachose impedance. High-frequency decoupling capacitors inobatsirwa kubva kune yakananga kuburikidza-mu-pad yekubatanidza kune ndege dzepasi, kubvisa kureba kwekutevera zvachose.

Stack-up uye Dzorera Nzira

Ground plane proximity inokanganisa capacitor performance kuburikidza nekuderedzwa loop inductance uye yakagadziridzwa yekupisa manejimendi. High-frequency capacitors inofanira kureva ndege dzepasi dzisina kuvhiringidzwa pazvikamu zviri pedyo, nekunyatsocherechedza kudzorera nzira dzazvino dzinotevera nzira yekudzivirira zvishoma. Kuparadzanisa ndege dzepasi dzinomanikidza kudzorera mafungu munzira dzakareba, kuwedzera mwaranzi uye kukanganisa kudzvinyirira ruzha.

Zvakajairwa Kukundikana Modes yePCB Capacitors

Mechanical Kukundikana

Ceramic capacitor kupwanya mhedzisiro kubva kumagetsi kusagadzikana panguva yekusangana, kubata, kana kupisa bhasikoro, kuratidza sekuderedzwa capacitance kana akazara akavhurika maseketi. Flexure-induced kutadza kunoitika kana bhodhi kukotama ichidarika chikumbaridzo checeramic muviri wekutyoka, kunyanya zvichikanganisa saizi hombe dzekesi uye macapacitor akaiswa padyo nemipendero yebhodhi. Automated optical inspection kashoma kuona makatsemuka, zvichiita kuti kushanda kwekuyedza kuve kwakakosha.

Electrolytic Degradation

Electrolytic capacitors inokundikana kuburikidza ne electrolyte yakaoma-kunze pane yakakwirira tembiricha, zvishoma nezvishoma ichiwedzera ESR uye ichideredza capacitance kusvikira kushanda kwawira pasi pemiganhu inogamuchirwa:

• Reverse voltage - Inogona kukonzera njodzi venting kana kuputika mualuminium electrolytics
• Yakawandisa ripple current -Inogadzira kupisa kwemukati kunowedzera kuchembera
• Tantalum ignition -Voltage transients inogona kukonzeresa kutadza kukuru kunoda kuderedzwa kwakafanira

Overvoltage uye Bias Effects

Overvoltage breakdown punctures dielectric material, inogadzira zvisingaperi masekete mapfupi anogona kukuvadza zvikamu zvakatenderedza. DC bias effects in high-capacitance X5R uye X7R MLCCs inogona kuderedza hunobudirira capacitance ne50-80% pa rated voltage, inoda kusanganiswa kwakafanana kana kutamira kune hukuru hwemakesi makuru kuchengetedza kushanda pasi pemamiriro ekushanda.

Zvikumbiro zvePCB Capacitors

• Michina yekukurukurirana inovimba zvakanyanya nePCB capacitors yemagetsi ekugadzirisa, chiratidzo chekubatanidza, uye RF impedance inoenderana neyakasiyana ma frequency mabhendi.
• Zvekushandisa pakurapa inoda yakakwirira-reliability capacitors inosangana neyakaomesesa chengetedzo miyero yemurwere-yakabatana michina uye hupenyu-akakosha ekutarisa masisitimu.
• Industrial control systems shandisa macapacitor mumadhiraivha emota, magetsi anoshandura, uye sensor interfaces inoshanda kune yakawedzera tembiricha marenji.
• Zvevatengi zvemagetsi Inosanganisira huwandu hukuru hwemaminiature ceramic capacitors anogonesa compact smartphones uye inopfeka michina.
• Magetsi emagetsi emagetsi emotokari shandisa yakakwira-voltage capacitors inogadzirisa kilowatt-level simba kuyerera.

mhedziso

Zvakajairwa PCB Capacitor Nyaya dzatinoona

Kwemakore ekutsigira PCB gungano paHighleap Electronics, takaona kuti nyaya dzakawanda dzine chekuita necapacitor — DC bias kurasikirwa muMLCCs, kufuratirwa kushomeka, kana kusakwana kwemakanika kudzora kushushikana — zvinodzivirika nekutanga dhizaini tarisiro. High-frequency decoupling matambudziko anowanzo kubva pakurongeka parasitics pane iyo capacitor pachayo.

Iyo Impact yeMiniaturization uye Yakakwira Frequencies

Sezvo madhizaini achive madiki uye nekukurumidza, echinyakare dhatabheti kukosha haacharatidzi chaiyo PCB maitiro. Kukundikana kwatinosangana nako kunowanzo dzokera kumashure kuburikidza nekuiswa, ESL/ESR mhedzisiro, kana tembiricha inodzikira nyaya pane zvisiri izvo capacitance kukosha.

Kukosha kweEarly Engineering Collaboration

Chikwata chedu chinokurudzira kubvunzana nekukurumidza kuti vaongorore kusarudzwa kwe capacitor , kuiswa kwayo, uye kugona kwayo kugadzira. Nekusimbisa marongerwo, kuyedza sarudzo dzemapakeji, uye kugadzirisa maitiro ekugadzira panguva yeprototyping, tinobatsira kudzivirira matambudziko tisati tagadzira uye kuona kuti mashandiro akasimba uye kuvimbika kwakasimba.