I-Mastering PCB Design: Amasu, Imihlahlandlela kanye Nemikhuba Engcono Kakhulu

I-PCB ifana nohlaka lwamathambo kanye nohlelo lwezinzwa lwamasekethe kagesi, idlala indima ebalulekile kumaphrojekthi wobunjiniyela be-elekthronikhi. Kodwa-ke, abantu abaningi abaqondi noma abanalo ulwazi olwanele mayelana nokwakhiwa kwe-PCB.

Phakathi neminyaka yami yaseyunivesithi, ngaba nesithakazelo esikhethekile ebhodini lesifunda nomklamo wesifunda se-hardware, futhi ngazitadisha ngenkuthalo lezi zifundo. Ngaleso sikhathi, ngangikholelwa ukuthi ukuthola umsebenzi ohilela i-computer-aid design (CAD) endaweni yasehhovisi ngemva kokuthweswa iziqu kungaba kuhle. Ngemva kokuthweswa iziqu, ngathola isikhundla ngempumelelo enkampanini yama-electronic eGuangzhou, lapho ngasebenza khona njengonjiniyela we-PCB. Ekuqaleni, kwakudingeka ngifunde kahle imisebenzi ehlukahlukene, okuhlanganisa ukudweba okuhleliwe, ukukhetha izingxenye, ukuhlelwa kwe-PCB, i-prototype soldering, ukulungisa iphutha, ukudala i-bill of materials (BOM), nokulungiselela imiyalelo yomsebenzi. Lokhu okuhlangenwe nakho kwaphawula ukuqala kohambo lwami embonini yezogesi.

Iqhaza Elibalulekile Lemidwebo Yezinhlelo Kumklamo we-PCB

Nakuba umdwebo omuhle wohlelo ungenakuqinisekisa umzila omuhle, umzila wekhwalithi uqala ngohlelo oluhle. Lapho udala i-schematic, ukucatshangelwa okuphelele kuyadingeka, ngokucophelela ukugeleza kwesignali yesifunda sonke. Ukugeleza kwesignali okushelelayo nokuzinzile ukusuka kwesokunxele kuye kwesokudla kuhlelo kufanele kuhumushele ekugelezeni kwesignali okuhle okufanayo ku-PCB. Kutuswa ukunikeza ulwazi oluwusizo oluningi ngangokunokwenzeka kuhlelo.

Ngezinye izikhathi, lapho onjiniyela bokuklama isifunda bengatholakali, amakhasimende angase acele usizo lwethu ekuxazululeni izinkinga zesifunda. Abaklami, ochwepheshe, kanye nonjiniyela abenza lo msebenzi bavame ukwazisa, njengathi. Ngaphezu kolwazi oluvamile njengabaklami bezinkomba, ukusetshenziswa kwamandla, kanye nokubekezelelana, yiluphi olunye ulwazi okufanele lufakwe kuhlelo? Iziphakamiso ezilandelayo zingaphakamisa uhlelo olujwayelekile lube ngolusezingeni eliphezulu: faka ama-waveforms, ulwazi lomshini mayelana nendlu, ubude bemigqa ephrintiwe, izindawo ezingenalutho; khombisa ukuthi yiziphi izingxenye okufanele zibekwe ku-PCB; nikeza ulwazi lokulungisa, amabanga enani lezingxenye, ulwazi lokusaphazwa kokushisa, imigqa ephrintiwe ye-impedance elawulwayo , izichasiselo, izincazelo zesenzo sesifunda ezimfushane, nokuningi.

Imihlahlandlela yokusebenzisana okuphumelelayo ku-PCB Design

Uma ungazange uzenzele wena umzila, kubalulekile ukuthi unikeze isikhathi esanele sokubuyekeza ngokucophelela umsebenzi womklami womzila. Ngalesi sikhathi, ukuqapha okuncane kungadlula amakhambi ayikhulu. Ungacabangi ukuthi umuntu oholayo angayibamba imibono yakho. Imibono yakho neziqondiso zibaluleke kakhulu ezigabeni zokuqala zenqubo yokuklama umzila. Uma unikeza ulwazi olwengeziwe futhi lapho uhileleka kakhulu kuyo yonke inqubo yomzila, kuzoba ngcono i-PCB ewumphumela. Ukusungula indawo yokuqedela yesikhashana yomklami womzila—ukubuyekeza ngokushesha ukuqhubeka komzila ngokomzila owufunayo—kungavimbela umzila ukuba ungaphambuki endleleni, ngaleyo ndlela kunciphise amathuba okuphinda kusetshenzwe.

Imiyalo kanjiniyela womzila kufanele ihlanganise: incazelo emfushane yomsebenzi wesekethe, uhlelo lwe-PCB olukhombisa izindawo okokufaka nokuphumayo, imininingwane yesitaki ye-PCB (isb., ukushuba kwebhodi, inani lezendlalelo, imininingwane enemininingwane yesendlalelo ngasinye sesignali kanye nomhlabathi. indiza—amandla, umhlabathi, isignali ye-analog, isiginali yedijithali, nesiginali ye-RF); okubonisa ungqimba ngalunye oludingayo; izidingo zokubeka izingxenye ezibalulekile; izindawo eziqondile zezingxenye ze-bypass; imiphi imigqa ephrintiwe ebalulekile; yimiphi imigqa edinga ukuphrinta kwe-impedance okulawulwayo; yimiphi imigqa edinga ubude obufanisiwe; izilinganiso zengxenye; yimiphi imigqa ephrintiwe edinga ukuhlukaniswa (noma ivalwe ndawonye); yimiphi imigqa edinga ukuhlukaniswa (noma ivalwe ndawonye); yiziphi izingxenye ezidinga ukuhlukaniswa (noma zivalwe ndawonye); yiziphi izingxenye ezidinga ukubekwa phezu kwe-PCB futhi okudingeka zibekwe ngaphansi. Ungalokothi ukhononde ngokunikeza ukwaziswa okuningi kakhulu kwabanye—Ingabe kuncane kakhulu? Yebo; Ingabe kuningi kakhulu? Cha.

Ukufunda Emaphutheni: Ukubaluleka Kokubekwa Kwengxenye Ku-Complex PCB Designs

Cishe eminyakeni eyi-10 edlule, ngaklama ibhodi lesifunda elinezingqimba eziningi—zombili izinhlangothi zebhodi zazinezingxenye. Ibhodi lalivikelwe endlini ye-aluminiyamu enegolide elinezikulufu eziningi (ngenxa yezidingo eziqinile zokumelana nokushaqeka). Izikhonkwane zokuphakela ngokuchema zanikezwa ngebhodi. Lona kwakuwumshini oyinkimbinkimbi kakhulu. Ezinye izingxenye ebhodini zazisetshenziselwa ukuhlolwa kokusetha (SAT). Nokho, ngangizibalule ngokucacile izindawo zalezi zingxenye. Ungaqagela ukuthi lezi zingxenye zafakwa kuphi zonke? Kunjalo, zafakwa phansi ebhodini. Lapho unjiniyela womkhiqizo kanye nochwepheshe kufanele bahlukanise lonke umshini, baqedele ukulungiselelwa, bese bephinde baluhlanganise, abazange bajabule. Angiphindanga ngenza lelo phutha kusukela lapho.

Ukuthuthukisa Ukusebenza Kwe-PCB Nge-Strategic Circuit Layout

Njengakuma-PCB, isikhundla sinquma yonke into. Lapho isekethe ibekwe ku-PCB, lapho izakhi zayo ezithile zesekethe zifakwe khona, nokuthi yiziphi ezinye izifunda eziseduze nayo konke kubalulekile.

Ngokuvamile, izindawo okokufaka, okokukhiphayo, nezinto ezinikezwa amandla zinqunywa kusengaphambili, kodwa amasekhethi aphakathi kwawo adinga “ubuhlakani” obuthile. Yingakho ukunaka imininingwane yomzila kuzoletha imbuyiselo ebalulekile. Kusukela endaweni yezingxenye ezibalulekile, cabangela isekethe ethile nayo yonke i-PCB. Ukucacisa izikhundla zezingxenye ezibalulekile kanye nezindlela zesignali kusukela ekuqaleni kusiza ukuqinisekisa ukuthi umklamo ufeza imigomo yokusebenza elindelekile. Ukulungisa idizayini okokuqala kunganciphisa izindleko nengcindezi—futhi kunciphise umjikelezo wokuthuthukiswa.

Ukwengeza, ake sixoxe ngalawo “maphedi akhethekile” ku-PCB:

Okokuqala, i-teardrop pad I-teardrop ukuxhumana kokwehla phakathi kwephedi ne-conductor noma phakathi kwe-conductor ne-via. Inhloso yokubeka i-teardrop ukuvimbela indawo yokuxhumana phakathi komqhubi nephedi noma umqhubi kanye ne-via ukuthi inganqamuki lapho ibhodi lesifunda lingaphansi kwamandla amakhulu angaphandle, kanye nokwenza ibhodi lesifunda le-PCB libukeke lilihle kakhulu. Umsebenzi we-teardrop ukuvimbela ububanzi bomugqa wesignali kusukela ekunciphiseni ngokuzumayo, okungenza ukuxhumana phakathi komzila kanye ne-pad yengxenye kube bushelelezi futhi kuxazulule inkinga yokuphuka kalula koxhumano phakathi kwephedi kanye nomzila.

1. Ekushiseleni, ingavikela iphedi futhi ivimbele iphedi ukuthi ingawi ngesikhathi sokushisela okuningi.
2. Thuthukisa ukwethembeka koxhumano (ukugwema ukuqhekeka okubangelwa ukulinganisa nokususwa kwe-vias ekukhiqizeni)
3. I-impedance ebushelelezi, yehlisa ushintsho olubukhali lwe-impedance Ekwakhiweni kwe-PCB, ukuze wenze iphedi iqine ngokwengeziwe futhi ivimbele iphedi ukuthi inganqamuki kumqhubi ngesikhathi sokwenziwa kwebhodi lomshini, indawo yoguquko imvamisa ukuhlelwa phakathi kwephedi nomqhubi, emise okufana ne-conductor. i-teardrop, yingakho ngokuvamile ibizwa ngokuthi i-teardrop (Izinyembezi).

Okwesibili, izinyo lokukhipha amanzi. Le nto ibizwa ngokuthi izinyo lokukhipha amanzi, igebe lokukhipha amanzi, noma igebe lenhlansi. Igebe lenhlansi liyizinhlangothi ezimbili zonxantathu ezinama-engeli abukhali abheke komunye nomunye, kanti iziphetho zonxantathu zihlukaniswe kusukela ku-10 mils kuya ku-6 mils okungenani. Unxantathu owodwa usekelwe phansi, kanti omunye uxhunywe emgqeni wesignali. Lonxantathu awuyona ingxenye kodwa wenziwe ngezendlalelo ze-foil zethusi ezisetshenziswa enqubweni yokuqondisa i-PCB. Laba nxantathu badinga ukufakwa engqimbeni ephezulu (uhlangothi lwengxenye) ye-PCB futhi abakwazi ukumbozwa yi- solder resist.

1. Ngesikhathi sokuhlolwa kokuhlinzwa kokushintsha izinto zamandla noma ukuhlolwa kwe-ESD, amandla kagesi aphezulu azokhiqizwa kuzo zombili iziphetho ze-inductor yemodi evamile, okubangela i-arcing. Uma ibanga lezingxenye ezizungezile liseduze, lingalimaza izingxenye ezizungezile. Ngakho-ke, ithubhu yokukhipha noma i-varistor ingaxhunywa ngokuhambisana emikhawulweni yayo emibili ukuze inciphise i-voltage yayo futhi ngaleyo ndlela ibambe iqhaza ekucimeni i-arc. Nakuba ukubeka isivikeli sokuhlinza kuphumelela, kubiza kakhulu.
2. Enye indlela yokwengeza izinyo lokukhipha kuzo zombili iziphetho ze-inductor yemodi evamile ekwakhiweni kwe-PCB, ukuze i-inductor ikhiphe emikhawulweni emibili ekhonjiwe yezinyo lokukhipha, igweme ukukhishwa kwezinye izindlela, ngaleyo ndlela inciphise umthelela endaweni ezungezile futhi elandelayo. -izingxenye zesiteji.

Izikhala zokukhipha azidingi izindleko ezengeziwe, vele uzidwebe ku-PCB lapho udweba ibhodi, kodwa kubalulekile ukuqaphela ukuthi le ndlela yokukhipha igebe iyigebe lokukhipha umoya futhi lingasetshenziswa kuphela ezindaweni lapho i-ESD yenzeka khona ngezikhathi ezithile. Uma isetshenziswa ezindaweni lapho i-ESD ivela khona njalo, amadiphozithi ekhabhoni azonqwabelana emaphuzwini amabili kanxantathu ngenxa yokuphuma kaningi, ekugcineni kubangele isifunda esifushane esikhaleni sokuphuma futhi kubangele ukujikeleza okufushane unomphela komugqa wesiginali phansi, okuholela ekutheni ukwehluleka kwesistimu.

Eqinisweni, ziningi izinto ezijabulisayo ekwakhiweni kwe-PCB, kodwa ngokuzilolongela kuphela ungathola ukuqonda okujulile. Uma abangani benemizwa mayelana ne-PCB design ngemva kokufunda lesi sihloko, bangasithinta ukuze bashintshisane.

Ekuhleleni ukukhiqiza, kuyasiza futhi ukuqhathanisa lesi sihloko nokukhethwa kwezinto ze-PCB kanye nokuqhathaniswa kokuphela kobuso ngaphambi kokuqedela iphakheji yokwenziwa noma yokuhlanganiswa.

Isiphetho

Idizayini ye-PCB ibalulekile ku-elekthronikhi, yakha umnyombo wesekethe. Nokho, ukuqonda ngokuvamile kulinganiselwe. Ama-schematics aphelele, anemininingwane yezinhlobo zamagagasi, izinsimbi, nokubeka, kusekela umzila wekhwalithi. Ukubuyekeza okuqinile, ukuxhumana okucacile, kanye nendlela yokuqala/ukucaciswa kwengxenye kuvimbela izinkinga, kuqinisekisa ukwaneliseka, nokwandisa ukusebenza kahle. Amaphedi akhethekile (izinyembezi, amazinyo aphumayo) akhulisa ukwethembeka ngokuvimbela ukuhlukaniswa nokunciphisa amandla kagesi aphezulu. Isipiliyoni nokwabelana ngolwazi kuyisihluthulelo sokwenza kahle ukuklama kwe-PCB.