Amaphutha Okuklama Okujwayelekile kwe-PCB kanye Nemikhuba Engcono Kakhulu Yonjiniyela Be-Electronics

Ukuklama amabhodi wesekethe aphrintiwe (ama-PCB) kuyisici esiyinkimbinkimbi nesibalulekile sokuthuthukiswa komkhiqizo we-elekthronikhi. Ukugwema amaphutha avamile ekwakhiweni kwe -PCB kubalulekile ukuqinisekisa ukusebenza, ukuthembeka, kanye nokusebenza kahle kwezindleko zamadivayisi kagesi. Kulesi sihloko, sizohlola ngokujulile amaphutha okuklama i-PCB avame kakhulu futhi sinikeze ukuqonda okuningiliziwe, ulwazi lwangemuva, idatha efanele, kanye nezibonelo ezengeziwe zokusiza onjiniyela ukuthi bathuthukise imiklamo yabo ye-PCB.

Imikhondo enganele ye-High Currents

Enye yezinselelo eziyisisekelo ekwakhiweni kwe-PCB ukuphatha imisinga ephezulu. Lapho umkhondo we-PCB kufanele uthwale wamanje mkhulu kunamamilimitha angamakhulu ambalwa, ububanzi obuncane bungase bunganeli. Okucatshangelwayo okubalulekile ububanzi nobukhulu be-trace. Ukulandelelwa kwezendlalelo zangaphandle kungathwala okwamanje kakhulu ngenxa yokugeleza komoya okungcono nokunqamuka kokushisa. Isisindo sethusi, esikalwa ngama-ounces ngonyawo lwesikwele ngasinye, sinquma ukujiya komkhondo. Ukukhetha ububanzi bokulandelela obufanele kubalulekile, futhi onjiniyela bangasebenzisa izibali zobubanzi bokulandelela ngokusekelwe kumazinga omkhakha afana ne-IPC-2221. Ukunyuka kwezinga lokushisa okuvunyelwe kokulandela umkhondo kufanele kucaciswe ukuze kubalwe umthamo wayo wamanje wokuthwala. Ukuze uthole imisinga ephezulu, ukukhuphuka kwezinga lokushisa okungama-20C noma ngaphezulu kungase kudingeke.

Amaphutha Kumaphethini okufika

Amaphethini okufika, ngezinye izikhathi abizwa ngokuthi izinyathelo, adlala indima ebalulekile ekwakhiweni kwe-PCB. Nakuba isofthiwe yokuklama ye-PCB ihlinzeka ngamalabhulali ezingxenye ze-elekthronikhi, ukusebenzisa izingxenye ezingaphandle kwala malayibhulali kungase kudinge ukwakhiwa mathupha kwamaphethini okufika. Ngisho nengxenye encane yokuchezuka kwemilimitha esikhaleni se-pad-to-pad kungaholela ezinkingeni zokuqondanisa ngesikhathi sokusoda. Onjiniyela kufanele banake ngokucophelela ukunemba kwephethini yokufika ukuze baqinisekise ukubekwa kwengxenye efanele kanye ne-soldering.

Ukulungisa Ukwakheka Kwe-Antenna Kwemiklamo Engenantambo

Ubuchwepheshe obungenazintambo bugcwele ku-electronics wesimanje, futhi ukwakheka kwe-antenna ye-PCB kubalulekile ekusebenzeni kahle. Ukumatanisa kokuphazamiseka phakathi kwe-transceiver kanye ne-antenna kubalulekile ukuze kukhuliswe ukudluliswa kwamandla. Ulayini wokudlulisa oxhuma uthi kanye ne-transceiver ngokuvamile kufanele ube nokubambezeleka okungu-50-ohm. Amathuluzi akhethekile afana ne-AppCad esuka ku-Avago angasiza ukubala ubukhulu bomugqa wokudlulisela we-PCB ukuze kuzuzwe ukuvinjelwa okufanele. Ukwengeza, amasekhethi afanayo afana namanethiwekhi e-LC pi-network avame ukudingeka ukuze ulungise kahle i-antenna impedance.

Ukubekwa kwe-Decoupling Capacitors

Ama-Decoupling capacitor ayingxenye ebalulekile ekwakhiweni kwe-PCB, ikakhulukazi uma usebenzisana namasekhethi edijithali nawe-analog. Inhloso yabo eyinhloko ukuhlinzeka ngokuhlinzekwa kwamandla kagesi ahlanzekile futhi azinzile ezingxenyeni ezibucayi, ukuqinisekisa ukusebenza okufanele nokunciphisa ingozi yokuphazamiseka komsindo.

Ukuze uqonde ukubaluleka kokukhipha ama-capacitor, kubalulekile ukubamba ukuthi asebenza kanjani. Uma i-IC yedijithali ishintsha, idonsa ukushuba okufushane kwamandla kusuka kumandla kagesi. Ngaphandle kokuxhuma ama-capacitor, lokhu kuhlasela kungadala ukwehla kwamandla kagesi kuwo wonke amathrekhi nezindiza zamandla, okubangele ukushintshashintsha kwamandla kagesi kumaphini wamandla e-IC. Lokhu kuguquguquka kungaholela kumazinga anengqondo angalungile, i-signal jitter, kanye nokungasebenzi kahle kwedivayisi.

Ukubeka ama-decoupling capacitor eduze ngangokunokwenzeka kumaphini wamandla we-ICs kubalulekile ekusebenzeni kwawo ngempumelelo. Ngokwenza kanjalo, basebenza njengama-reservoirs endawo, bahlinzeka ngogesi osheshayo ngesikhathi sokushintsha nokuvimbela ukwehla kwamandla kagesi. Lokhu kuba seduze kunciphisa inductance kanye nokumelana namathrekhi axhuma ama-capacitor kuma-ICs, okuqinisekisa ukulethwa kweshaja okusheshayo nangempumelelo.

Lapho ukhetha ama-decoupling capacitor, onjiniyela kufanele bacabangele inani lamandla abo ngokucophelela. I-capacitance efanelekile incike ezidingweni zamandla kanye nemvamisa yokushintsha yezingxenye ezihloselwe ukuzisekela. Kuvamile ukusebenzisa ama-decoupling capacitor amaningi wamanani ahlukahlukene e-capacitance ku-PCB ukubhekana nobubanzi obuhlukahlukene bomsindo.

Ezingxenyeni ezizwela kakhulu njengeziguquli ze-analog-to-digital (ADCs), ingxenye eyengeziwe ingase idingeke—i-inductor. Ukubeka i-inductor ochungechungeni nge-decoupling capacitor kwakha isihlungi se-LC se-low-pass. Lesi sihlungi siwususa ngempumelelo noma yimuphi umsindo wokunikezela osele, sithuthukise nakakhulu ukusebenza kwezingxenye ezibucayi ze-analog.

Kafushane, ama-decoupling capacitor abalulekile ekugcineni amandla kagesi ahlanzekile futhi azinzile kuma-PCB. Onjiniyela kufanele bawabeke eduze kakhulu nezikhonkwane zamandla zama-ICs, bakhethe amanani afanele we-capacitance, futhi, kwezinye izimo, basebenzise ama-inductors ukuze benze izihlungi ze-low-pass. Ukunganaki ukubekwa okulungile nokukhethwa kwama-capacitor ahlukanisayo kungaholela ekungazinzini kokunikezwa kwamandla, ukuphazamiseka komsindo, nokusebenza okonakele kwamasekhethi kagesi.

Ukuthuthukisa Isakhiwo Sokushintsha Izilawuli

Izilawuli zokushintsha ziyinketho evamile yokulawulwa kwamandla kagesi emiklamo yesimanje ye-elekthronikhi ngenxa yokusebenza kahle kwazo nekhono lokonga impilo yebhethri. Kodwa-ke, ukwenza ngcono ukwakheka kwezilawuli ezishintshayo kubalulekile ukuze kuqinisekiswe ukusebenza kwazo okufanele futhi kuncishiswe izinkinga ezingaba khona.

Ukushintsha izilawuli zisebenza ngokushintsha ngokushesha i-voltage yokufaka nokuvala ukuze kukhiqizwe i-voltage ephumayo oyifunayo. Nakuba le ndlela isebenza kahle, ingethula umsindo ne-voltage ripple uma ingaphathwa kahle. Ukuze kuthuthukiswe ukwakheka kwezilawuli zokushintsha, onjiniyela kufanele balandele imihlahlandlela enconyiwe yomkhiqizi eduze.

Isici esisodwa esibalulekile sokushintsha ukwakheka kwesilawuli ukubekwa kwama-input capacitor. Lawa ma-capacitor abalulekile ekwehliseni ukuguquguquka kwamandla kagesi kanye nokunciphisa ukuphazamiseka kwe-electromagnetic (EMI). Ukuwabeka eduze ngangokunokwenzeka kumaphini okufaka nokukhiphayo omlawuli kubalulekile. Ukukhethwa kohlobo lwe-capacitor kanye nevelu ye-capacitance nakho kudlala indima ebalulekile ekunciphiseni umsindo nokuqinisekisa ukuzinza.

Okunye okucatshangelwayo ukwakheka kweluphu yempendulo kanye nezingxenye zesinxephezelo. Lezi zingxenye zibalulekile ekugcineni ukulawulwa kwamandla kagesi okuphumayo kuzinzile. Onjiniyela kufanele balandele ngokucophelela ukulandelelwa kwe-loop yempendulo kanye nenethiwekhi yesinxephezelo, kugcinwe kufushane ngangokunokwenzeka ukuze kuncishiswe imiphumela ye-parasitic.

Ukuphathwa kwe-Grounding kanye nokushisa nakho kuyizici ezibalulekile ekushintsheni ukwakheka kwesilawuli. Amasu afanele okumisa phansi, njengokumisa inkanyezi, asiza ukunciphisa izihibe zomhlabathi futhi athuthukise ukuvikeleka komsindo. Ukwengeza, ukuchithwa kokushisa okuphumelelayo kubalulekile, njengoba izilawuli zokushintsha zingakwazi ukukhiqiza ukushisa ngesikhathi sokusebenza. Ukuthululwa kwethusi okwanele kanye nama-vias okusiza ukushisa kufanele kufakwe ekwakhiweni kwe-PCB.

Kubalulekile ukuqaphela ukuthi idatha yesilawuli sokushintsha ngasinye singaba nezincomo ezithile zesakhiwo, futhi onjiniyela kufanele babheke la madokhumenti ukuze bathole isiqondiso. Ukudebeselela ukulandela le mihlahlandlela kungaholela ekwehleni kokusebenza kahle, ukwanda kwe-EMI, kanye nezinkinga ezingase zibe khona zokwethenjelwa.

Ukuphatha Okufanelekile Kwezimpumputhe Nezingcwatshwayo

Ukusetshenziswa kwe-vias kuvamile emiklamo ye-PCB, kodwa onjiniyela kufanele baqaphe lapho besebenzisa ama-vias angaboni futhi agqitshwe. Nge-Vis dlula kuzo zonke izingqimba zebhodi, okungase kwandise usayizi we-PCB nezinselele zomzila. I-Vis eyimpumputhe ixhuma ungqimba lwangaphandle kungqimba lwangaphakathi, kuyilapho ama-vias angcwatshwe axhuma izingqimba ezimbili zangaphakathi. Kodwa-ke, lawa ma-vias anemikhawulo esekelwe ekutheni izendlalelo zinqwabelane kanjani ebhodini. Bangakwazi futhi ukwandisa izindleko ze-prototyping kakhulu, ngakho ukuhlela ngokucophelela kubalulekile.

Ukuphatha I-High-Speed ​​Traces

Ukulandelela isignali yesivinini esikhulu kudinga ukunakwa ekulandeleni ubude nendlela. Amakristalu efrikhwensi ephezulu adinga umzila ngokucophelela wobuqotho besignali. Nakuba imiklamo eminingi esekelwe ku-microcontroller inezimpawu ezimbalwa zesivinini esikhulu, imikhiqizo esebenzisa ama-microprocessors anesivinini esikhulu anedatha yangaphandle namabhasi ekheli kufanele ibeke phambili ukulandelela ukulandelela ukusebenza kahle. Ukubonakaliswa kwesignali, ukuba sengozini yokuphazanyiswa yi-electromagnetic interference (EMI), kanye nezindleko eziphakeme kungabangelwa ukulandela umkhondo okude kakhulu.

1. Ukulandelela Ubude Nokulawulwa Kokuphazamiseka: Amasignali esivinini esikhulu azwela ukulandelela ubude. Ukugcina ubuqotho besignali nokunciphisa ukuwohloka kwesignali, onjiniyela kufanele balawule ngokucophelela ubude bokulandela isivinini esikhulu. Ukuchezuka kubude bokulandelela kungase kubangele isiginali yesikhathi i-skew kanye ne-jitter. Ukwengeza, ukulawulwa kwe-impedance kubalulekile kumasignali anesivinini esikhulu. Izindlela zokulandela umkhondo ezilawulwayo ziqinisekisa ukuthi isignali ihamba phansi ngokulandela umkhondo ngaphandle kokubonisa noma ukuwohloka kwesignali.
2. Ukubonakaliswa Kwesiginali: Ubude bokulandelela obuningi bungaholela ekukhanyeni kwesignali, lapho ingxenye yesiginali ikhombisa emuva ibheke emthonjeni. Ukubonakaliswa kwesignali kungabangela ukuwohloka kwesignali kanye nokusebenza kwesistimu kube nomthelela. Onjiniyela kufanele babale ubude bokulandelela kanye ne-impedance ukuze banciphise le miphumela.
3. I-Electromagnetic Interference (EMI): Amasignali anesivinini esikhulu akhiqiza i-EMI, engaphazamisa izingxenye eziseduze. Ukubekwa ngokucophelela kokulandelelwa kwesivinini esikhulu kanye nokusetshenziswa kwezindiza eziphansi nokuvikela kungasiza ukunciphisa izinkinga ze-EMI.
4. I-Cross-Talk: Ukulandelelwa kwesivinini esikhulu ezindaweni eziseduze kungabangela inkulumo-mpikiswano, lapho amasignali aphazamisana khona. Onjiniyela kufanele bacabangele ukuhlukaniswa kwezikhala, ukuzihlukanisa, nokuvikela ukuze kuncishiswe izinkulumo ezihlukene.
5. Ukumiswa: Ukunqanyulwa okufanele kokulandelelwa kwesivinini esiphezulu kubalulekile ukuze kuvinjwe ukubonakaliswa kwesignali nokugcina ubuqotho besignali. Izinqamuli zokunqamula noma ezinye izindlela zingadingeka.
6. Ukuhamba ngakubili okuhlukile: Amapheya ahlukile esivinini esikhulu, ajwayele ukusetshenziselwa amabhasi edatha, kufanele ahanjiswe ngendlela enobude obunembile obufanayo kanye ne-impedance elawulwayo ukuze kuqinisekiswe ubuqotho besignali.

Ngamafuphi, ukuphatha ama-trace asheshayo kubalulekile ekugcineni ubuqotho besignali kanye nokuthembeka kohlelo ekwakhiweni kwe-PCB. Onjiniyela kumele bacabangele ubude be-trace, ukulawulwa kwe-impedance , ukubonakaliswa kwesignali, i-EMI, ukukhuluma okuphambene, ukuphela, kanye nomzila we-differential pair lapho besebenza ngamasignali asheshayo. Ukunamathela emikhubeni emihle kakhulu nokusebenzisa amathuluzi okuklama akhethekile kungasiza ekubhekaneni nezinselele ezihambisana nama-trace asheshayo.

Ukubhekana Nokuphazamiseka Kwe-Electromagnetic (EMI)

I-EMI iyinselelo evamile ekwakhiweni kwe-PCB engaphazamisa ukusebenza kwemishini kagesi. I-EMI isho ukukhiqizwa okungahlosiwe, ukudluliselwa, noma ukwamukela amandla kazibuthe kagesi aphazamisa ukusebenza kahle kwamasekhethi kagesi. Ukuqinisekisa izisetshenziswa zikagesi ezithembekile, kubalulekile ukubhekana nokukhathazeka kwe-EMI phakathi nokwakhiwa kwe-PCB.

Isu elilodwa elisebenzayo lokunciphisa i-EMI ukuhlela izingxenye ze-PCB zibe amaqembu asebenzayo ngokusekelwe kuzici zabo zikagesi nemisebenzi ehlosiwe. Lokhu kuhlukaniswa kusiza ukuvimbela ukuphazamiseka phakathi kwezingxenye namasistimu angaphansi. Isibonelo, amabhulokhi e-analog nawedijithali kufanele ahlukaniswe ngokomzimba ukuze kuncishiswe amandla omsindo wedijithali othinta amasignali e-analog.

Ukwengeza, ukusetshenziswa kwezintambo ezivalekile neziqukathi zensimbi kungasiza ukuqukatha nokuvikela ukukhishwa kwe-electromagnetic. Izintambo ezivaliwe zivimbela i-EMI ekhishwayo ukuthi ingaphunyuki endaweni ebiyelwe nge-PCB, kuyilapho iziqukathi zensimbi zisebenza njengamakheji e-Faraday, zivimbela imithombo ye-EMI yangaphandle ukuthi iphazamise izingxenye zangaphakathi.

Ukunciphisa ama-engeli acijile ekulandeleleni nokugwema ukugoba kwe-engeli engakwesokudla kunganciphisa ukukhishwa kwe-EMI. Ama-engeli abukhali angasebenza njengama-antenna, akhipha amandla kazibuthe kagesi. Ngokusebenzisa amajika ahamba kancane noma amakhona ane-chamfered emzileni wokulandela umkhondo, onjiniyela bangawunciphisa lo mphumela.

Izindlela ezifanele zokubeka phansi zibalulekile ekuphathweni kwe-EMI. Ukubeka phansi inkanyezi, lapho wonke amaphuzu aphansi exhumeka endaweni ephakathi nendawo, kusiza ukuvimbela amaluphu aphansi futhi kuqinisekisa indlela enezihibe eziphansi zokubuya kwamaza. Izindiza eziphansi kanye nama-vias okuthunga nakho kungathuthukisa ukuma futhi kunciphise ukuthambekela kwe-EMI.

Ezimeni lapho i-EMI ihlala iyinkinga enkulu, ukusetshenziswa kwezihlangu ze-EMI noma izihlungi kungase kudingeke. Izingxenye zokuvikela noma izigaba ze-PCB ngezinto eziqhutshwayo zingaqukatha ukukhishwa, kuyilapho izihlungi zingacindezela umsindo ongafuneki emandleni nasezilayini zesignali.

Ekugcineni, ukukhuluma ne-EMI kubalulekile ekusebenzeni okuthembekile kwemishini kagesi, ikakhulukazi ezinhlelweni lapho ikhwalithi yesiginali kanye nokuba sengozini kokuphazamiseka kubalulekile. Onjiniyela kufanele bacabangele amasu okunciphisa i-EMI kuyo yonke inqubo yokuklama ye-PCB ukuze kuqinisekiswe ukusebenza kahle kwamasistimu kagesi.

Isakhiwo Se-antenna Esinembile Sokuxhumana Okungenantambo

Ukudizayina izinti zokuxhumana okungenantambo ku-PCB kudinga ukunemba nokubambelela ezimisweni zikazibuthe kagesi. Isakhiwo se-antenna sithinta kakhulu ukusebenza okungenantambo kwemishini kagesi, futhi ukunemba ekwakhiweni kwe-antenna kungaholela ekuncishisweni kwebanga, ukuwohloka kwesignali, nokuxhumana okungafanelekile.

Okunye okucatshangelwayo okuyisisekelo kusakhiwo se-antenna ukufaniswa kwe-impedance. Ukufanisa i-impedance kuqinisekisa ukuthi i-transceiver (efana nemojula engenantambo) kanye nothi banamanani ahambisanayo okuvimbela ukudluliswa kwamandla aphezulu. I-Impedance, kulo mongo, ibhekisela ku-impedance eyinkimbinkimbi kokubili kwe-transceiver kanye ne-antenna, hhayi nje ukumelana kwabo okulula.

Ukuze kuzuzwe ukufanisa okufanele kwe-impedance, ulayini wokudlulisa oxhuma uthi ku-transceiver ngokuvamile kufanele ube ne-impedance engu-50-ohm. Izibali ezikhethekile namathuluzi, njenge-AppCad evela ku-Avago, angasiza onjiniyela ekunqumeni ubukhulu bolayini wokudlulisa we-PCB odingekayo ukuze kufaniswe i-impedance enembile.

Ngokungeziwe ekufanisweni kwe-impedance, amasekhethi afanayo afana namanethiwekhi e-LC pi-network avame ukudingeka phakathi kwe-antenna ne-transceiver. Lawa masekethi ashuna kahle i-impedance ye-antenna ukuze ifane kahle neye-transceiver, iqinisekisa ukudluliswa kwamandla afanele.

Isakhiwo se-antenna esinembile sibalulekile ekuxhumaneni okungenantambo, njengoba amandla esignali nobubanzi buthinteka ngokuqondile. Ukungalungi kwesakhiwo kungase kubangele ukuboniswa kwesignali, i-impedance engafani, nokuncipha kwamabanga okuxhumana.

Ubuchwepheshe obungenantambo butholakala yonke indawo kuma-electronics wesimanje, okwenza ukwakheka kwe-antenna kube isici esibalulekile somklamo we-PCB. Onjiniyela kufanele banake ngokucophelela ukufanisa i-impedance, ubukhulu belayini yokudlulisa, namasekhethi afanayo ukuze kuzuzwe ukusebenza okungenazintambo okuphelele.

Ukubaluleka Kokubuyekezwa Kwephrojekthi kanye Nokubuyekezwa Kwedizayini

Ukubuyekezwa kwephrojekthi nokubuyekezwa kwedizayini kuvame ukunganakwa kodwa kuyizinyathelo ezibalulekile ekwakhiweni kwe-PCB. Ukubuyekeza umklamo njalo ngokuqhathanisa nemibandela yezinga eliphezulu, imisebenzi eyabelwe, noxhumo lwesekethe kusiza ukuhlonza nokuvimbela amaphutha edizayini avamile. Ukubuyekezwa kontanga okwenziwa amanye amalungu eqembu kunganikeza imininingwane ebalulekile futhi kuqinisekise ukuthi umklamo uhlangabezana nezinjongo zawo.

Isiphetho

Idizayini ye-PCB iyisici esiyinkimbinkimbi nesibucayi sobunjiniyela be-electronics. Ukugwema amaphutha avamile nokunamathela emikhubeni ehamba phambili kungathuthukisa kakhulu ukusebenza, ukwethembeka, kanye nokuphumelela kwezindleko zamadivayisi kagesi. Onjiniyela kufanele banake ngokucophelela ububanzi bokulandelela, amaphethini okufika, izakhiwo ze-antenna, ama-decoupling capacitor, nezinye izici zedizayini ezibucayi ukuze kuqinisekiswe imiklamo ye-PCB ephumelelayo. Ukubuyekezwa okuvamile kwephrojekthi kanye nokubuyekezwa komklamo kubalulekile ukuze kubanjwe futhi kulungiswe amaphutha ngaphambi kokuthi aholele kuma-prototypes abizayo kanye nokubambezeleka ekufinyeleleni emakethe. Ngokulandela lezi zimiso, onjiniyela bangakha amadizayini e-PCB aqinile futhi asebenzayo ahlangabezana nezidingo zemikhiqizo yesimanje ye-elekthronikhi.

Uma lesi sidingo sithinta ukutholakala noma ukukhishwa komkhiqizo, siqhathanise nokukhiqizwa kwe-PCB yethusi esindayo kanye nokwakhiwa kwe-PCB ye-RF microwave ngaphambi kokuthumela amafayela okugcina ukuze abuyekezwe.