Ishicilelwe ibhodi yesekethe (I-PCB) ifunyanwa phantse kuzo zonke iintlobo zezixhobo ze-elektroniki. Ukuba kukho izinto ze-elektroniki kwisiqwenga sezixhobo, zikwabekwa kubungakanani obahlukeneyo bePCB. Ukongeza kokulungisa iindawo ezincinci ezincinci, owona msebenzi uphambili we-PCB kukubonelela ngombane phakathi kwezinto. Njengoko izixhobo ze-elektroniki ziba nzima ngakumbi nangakumbi, kuya kufuneka iindawo ezingakumbi nangakumbi, kwaye iintambo kunye namalungu akwi-PCB aye exineke ngakumbi nangakumbi. I-PCB esemgangathweni ijongeka ngoluhlobo. Bare Board (without parts on it) is also often referred to as “Printed Wiring Board (PWB).

I-substrate yebhodi ngokwayo yenziwe ngesixhobo esigqunyiweyo nesinganyangekiyo nokugoba. Izinto ezincinci zomgca ezinokubonwa ngaphezulu ngumfanekiso wobhedu. Ekuqaleni, ifoyile yobhedu igutyungelwe yibhodi yonke, kwaye icandelo eliphakathi litsaliwe kude kwinkqubo yokuvelisa, kwaye icandelo eliseleyo liba ngumnatha wemigca emincinci. Le migca ibizwa ngokuba ngabaqhubi okanye abaqhubi kwaye zisetyenziselwa ukubonelela ngokudibana kombane kwiindawo ezikwi-PCB.

Ukukhusela iindawo kwi-PCB, sithengisa izikhonkwane zabo ngqo kwi-wiring. Kwi-PCB esisiseko, iinxalenye zigxile kwelinye icala kwaye iingcingo zigxile kwelinye. Ke kufuneka senze imingxunya ebhodini ukuze izikhonkwane zingene ebhodini ziye kwelinye icala, ke izikhonkwane zamalungu zi-welding kwelinye icala. Ngenxa yoku, amacala angaphambili nangasemva e-PCB abizwa ngokuba yiCandelo leCandelo kunye neSolder Side ngokwahlukeneyo.

Ukuba kukho iindawo kwi-PCB enokususwa okanye ibuyiselwe emva kokwenza, iSokethi iya kusetyenziselwa ukufakela iinxalenye. Ngenxa yokuba isiseko sidityaniswe ngqo ebhodini, iinxalenye zinokudityaniswa ngokungafanelekanga. Iplagi ye-ZIF (iZero InserTIon Force) ivumela iinxalenye ukuba zifakwe kwaye zisuswe ngokulula. Ilever ecaleni kwesokethi inokubamba iindawo endaweni emva kokuzifaka.

Ukuqhagamshela ii-PCBS ezimbini enye kwenye, isixhobo sokuqhagamshela esiqhelekileyo sisetyenziswa rhoqo. Umnwe wegolide uqulethe iipads zethusi ezingenanto eziyinxalenye yeentambo zePCB. Ngokwesiqhelo, ukudibanisa, sifaka umnwe wegolide kwi-PCB enye kwi-Slot efanelekileyo (ebizwa ngokuba yi-Slot slot) kwenye i-PCB. In computers, display cards, sound cards, and similar interface cards are connected to the motherboard by means of a gold finger.

Umbala oluhlaza okanye omdaka kwi-PCB ngumbala wemaski e-solder. Lo maleko likhaka elikhuselayo elikhusele ucingo lobhedu kwaye lithintela iindawo ukuba zingadityaniswa kwindawo engeyiyo. Esinye isikrini sesilika siya kuprintwa kumaleko okumelana ne-solder. Ihlala ishicilelwe ngamagama kunye neesimboli (ubukhulu becala zimhlophe) ukubonisa indawo ezikuyo iindawo ebhodini. Screen printing surface is also known as icon surface

Igosa).

Iibhodi ezikwelinye icala

Njengoko besitshilo, kwi-PCB esisiseko, iinxalenye zigxile kwelinye icala kwaye iingcingo zigxile kwelinye. Because the wire appears on only one side, we call this TYPE of PCB single-sided. Ngenxa yokuba iiphaneli ezizodwa zazinezithintelo ezingqongqo kuyilo lwesekethe (kuba lalilinye icala, i-wiring ayinakuwela kwaye kufuneka ithathe indlela eyahlukileyo), kuphela ziisekethe zakuqala ezazisebenzisa ezo bhodi.

Iibhodi ezinamacala amabini

Ibhodi yesekethe ineentambo kumacala omabini. Kodwa ukuze usebenzise zombini iingcingo, kufuneka kubekho unxibelelwano olululo lombane phakathi kwala macala mabini. Le “bhulorho” phakathi kweesekethe ibizwa ngokuba ngumngxunya wesikhokelo (VIA). Imingxunya yesikhokelo yimingxunya emincinci kwi-PCB ezaliswe okanye egalelwe isinyithi enokuqhagamshelwa kwiingcingo kumacala omabini. Because a dual panel has twice the area of a single panel, and because the wiring can be interlaced (it can be wound around to the other side), it is better for more complex circuits than a single panel.

IiBhodi ezininzi

Ukuze wandise indawo enentambo, kusetyenziswa iibhodi zokubamba ngakwicala elinye okanye kabini. Ibhodi ye-multilayer isebenzisa iipaneli ezininzi eziphindwe kabini, kwaye umaleko wokugquma ubekwe phakathi kwepaneli nganye kwaye unamathele (ucofe). Inani leebhodi zebhodi limela iindidi ezininzi ezizimeleyo zokubamba iintambo, zihlala zilinani lezingqengqelo, kubandakanywa amacala amabini angaphandle. Most motherboards are built with four to eight layers, but it is technically possible to build up to 100 layers of PCBS. Uninzi lweekhompyuter ezinkulu zisebenzisa uninzi lweeebhodi zeebhodi zee-mama, kodwa ziye zasetyenziswa njengoko zinokuthi zithathelwe indawo ngamaqela eekhompyuter aqhelekileyo. Because the layers in a PCB are so tightly integrated, it’s not always easy to see the actual number, but if you look closely at the motherboard, you might be able to.

Umngxunya wesikhokelo (i-VIA) esisandula ukuwuchaza, ukuba usetyenziswe kwiphaneli ephindwe kabini, kufuneka ube kuyo yonke ibhodi

Kodwa kwi-multilayer, ukuba ufuna ukudibanisa eminye imigca, imingxunya yesikhokelo inokuchitha indawo yomgca kwezinye iindawo. Buried vias and Blind vias avoid this problem because they only penetrate a few layers. Blind holes connect several layers of internal PCBS to surface PCBS without penetrating the entire board. Imingxunya yokungcwatywa ixhunyiwe kuphela kwi-PCB yangaphakathi, ke ukukhanya akubonakali ngaphezulu.

Kwi-PCB ye-multilayer, wonke umaleko uqhagamshelwe ngqo kwicingo lomhlaba kunye nonikezelo lwamandla. Ke sihlela iileya njengoMqondiso, aMandla okanye oMhlaba. If the parts on the PCB require different power supplies, they usually have more than two power and wire layers.

Icandelo lokupakisha iteknoloji

Ngokusebenzisa iTekhnoloji yeHole

The technique of placing parts on one side of the board and welding the pins to the other side is called “Through Hole Technology (THT)” encapsulation. Eli candelo lithatha indawo enkulu kwaye umngxunya omnye ugqojoziwe kwipini nganye. Ke amalungu awo eneneni athabatha indawo kumacala omabini, kwaye amalungu adibeneyo akhulu kakhulu. Kwelinye icala, iinxalenye ze-THT ziqhagamshelwe ngcono kwi-PCB kunendawo zeTekhnoloji ePhakamileyo (SMT), esiza kuthetha ngayo kamva. Iziseko ezifana neziseko ezineentambo kunye nezixhobo ezifanayo kufuneka zinganyamezeli uxinzelelo, ke zihlala ziiphakheji ze-THT.

Umphezulu Onyuswe Technology

Kwizinto zeTekhnoloji ePhakamileyo (SMT), isikhonkwane sidityaniswe kwicala elinye kunye namalungu. This technique does not drill holes in the PCB for each pin.

Amalungu okuncamathisela umphezulu angadityaniswa kuwo omabini amacala.

I-SMT ikwanamalungu amancinci kune-THT. Compared to PCB with THT parts, PCB with SMT technology is much denser. SMT package parts are also less expensive than THT’s. Ayimangalisi into yokuba uninzi lweePCBS zanamhlanje zii-SMT.

Ngenxa yokuba amalungu kunye nezikhonkwane zamalungu zincinci kakhulu, kunzima kakhulu ukuzidibanisa ngesandla. However, given that current assembly is fully automated, this problem will only occur when repairing parts.

Inkqubo yoyilo

Kuyilo lwe-PCB, eneneni kukho amanyathelo amade kakhulu okudlula phambi kweentambo ezisesikweni. Oku kulandelayo yinkqubo ephambili yoyilo:

The system specifications

Okokuqala, ukucaciswa kwenkqubo yezixhobo ze-elektroniki kufuneka kucwangciswe. It covers system functionality, cost constraints, size, operation and so on.

System function block diagram

Inyathelo elilandelayo kukwenza idayagramu esebenzayo yenkqubo. Ubudlelwane phakathi kwezikwere kufuneka buphawulwe.

Divide the system into several PCBS

Ukwahlulahlula inkqubo kwi-PCBS ezininzi akupheleli nje ukunciphisa ubungakanani, kodwa kukwabonelela ngenkqubo yokufumana amandla okuphucula kunye nokutshintsha izinto. The system function block diagram provides the basis for our segmentation. Computers, for example, can be divided into motherboards, display cards, sound cards, floppy disk drives, power supplies, and so on.

Chonga indlela yokupakisha ekufuneka isetyenzisiwe kunye nobungakanani bePCB nganye

Once the technology and the number of circuits used for each PCB has been determined, the next step is to determine the size of the board. If the design is too large, then packaging technology will have to change, or re-split the action. Umgangatho kunye nesantya sedayagramu yesekethe nayo kufuneka ithathelwe ingqalelo xa kukhethwa itekhnoloji.

Zoba imizobo yesekethe yemizobo yazo zonke ii-PCB

Iinkcukacha zonxibelelwano phakathi kwamacandelo kufuneka ziboniswe kumzobo. I-PCB kuzo zonke iinkqubo kufuneka ichazwe, kwaye uninzi lwazo lusebenzisa i-CAD (Uyilo oluNcedisiweyo lweKhompyuter) okwangoku. Here is an example of a CircuitMakerTM design.

Umzobo wobume besekethe ye-PCB

Preliminary design of simulation operation

Ukuqinisekisa ukuba umzobo wesekethe owenziweyo uyasebenza, kufuneka uqale ulinganiswe kusetyenziswa isoftware yekhompyuter. Isoftware enjalo ingafunda iiplani kwaye ibonise indlela isekethe esebenza ngayo ngeendlela ezininzi. This is much more efficient than actually making a sample PCB and then measuring it manually.

Place the parts on the PCB

Indlela ezibekwe ngayo iindawo zixhomekeke kwindlela ezinxibelelana ngayo. Kufuneka zidityaniswe kwindlela efanelekileyo kakhulu. Ukufakelwa kweentambo ngokufanelekileyo kuthetha ukuba ukufutshane kwe-wiring kunye neendlela ezimbalwa (ezinciphisa inani lemingxunya yesikhokelo), kodwa siza kubuyela koku kwintambo yokwenyani. Here is what the bus looks like on a PCB. Placement is important in order for each part to have perfect wiring.

Uvavanyo lweentambo ezinokubakho ngokusebenza ngokuchanekileyo kwisantya esiphezulu

Ezinye zeekhompyuter zanamhlanje zinokujonga ukuba ukubekwa kwecandelo ngalinye kunokudityaniswa ngokuchanekileyo, okanye kujonge ukuba kungasebenza ngokuchanekileyo kwisantya esiphezulu. Eli nyathelo libizwa ngokuba lilungiselelo lamacandelo, kodwa asizukuya kude kakhulu koku. Ukuba kukho ingxaki kuyilo lwesekethe, iinxalenye zinokucwangciswa kwakhona ngaphambi kokuba isekethe ithunyelwe ngaphandle ebaleni.

Ukuthumela kwelinye ilizwe kwi-PCB

The connections in the sketch will now look like wiring in the field. Eli nyathelo lihlala lizenzekelayo, nangona utshintsho olwenziwa ngesandla ludla ngokufuneka. Below is the wire template for 2 laminates. Imigca ebomvu neluhlaza amele PCB iindawo maleko kunye maleko welding ngokwahlukeneyo. Isicatshulwa esimhlophe kunye nezikwere zibonisa ukumakisha kumgangatho wokuprinta kwescreen. Amachaphaza abomvu kunye nezangqa zimela ukubhola kunye nokukhomba imingxunya. Ngasekunene kakhulu sinokubona umnwe wegolide kumphezulu we-PCB. The final composition of this PCB is often referred to as the working Artwork.

Uyilo ngalunye kufuneka luhambelane neseti yemithetho, enjengezikhewu ezincinci ezigciniweyo phakathi kwemigca, ubuncinci bobubanzi bemigca, kunye neminye imiqobo esebenzayo. Ezi nkcukacha ziyahluka ngokwesantya sesekethe, amandla esignali ekufuneka sihanjisiwe, ubuntununtunu besekethe ekusebenziseni amandla kunye nengxolo, kunye nomgangatho wezinto kunye nezixhobo zokwenza. If the strength of the current increases, the thickness of the wire must also increase. Ukuze kuncitshiswe iindleko ze-PCB, ngelixa kuncitshiswa inani leengqimba, kuyafuneka ukuba unike ingqalelo ukuba le migaqo ihlangatyeziwe na. Ukuba ngaphezulu kwe-2 maleko afunekayo, umaleko wamandla kunye nongqameko lomhlaba zihlala zisetyenziselwa ukunqanda isiginali yokudlulisela kumaleko wesiginali uyachaphazeleka, kwaye unokusetyenziswa njengekhaka lomaleko wesiginali.

Ucingo emva kovavanyo lwesekethe

Ukuze uqiniseke ukuba umgca usebenza ngokufanelekileyo ngocingo, kufuneka uphumelele uvavanyo lokugqibela. Olu vavanyo lukwajonga unxibelelwano olungachanekanga, kwaye lonke unxibelelwano lulandela umzobo wesikim.

Ukuseka kunye nefayile

Kuba ngoku zikhona izixhobo ze-CAD zokuyila i-PCBS, abavelisi kufuneka babeneprofayili ehlangabezana nemigangatho ngaphambi kokuba benze iibhodi. Kukho imilinganiselo emiselweyo emiselweyo, kodwa eyona ixhaphakileyo kukuchazwa kweefayile zeGerber. Iseti yeefayile zeGerber zibandakanya isicwangciso somqondiso ngamnye, amandla kunye nomaleko womhlaba, isicwangciso sombane wokumelana ne-solder kunye nomphezulu wokuprinta kwescreen, kunye neefayile ezichaziweyo zokomba kunye nokushiya indawo.

Electromagnetic compatibility problem

Izixhobo zombane ezingakhelwanga kwinkcazo ye-EMC kunokwenzeka ukuba zikhuphe amandla ombane kwaye ziphazamisane nezixhobo ezikufuphi. I-EMC inyanzelisa ubuninzi kuthintelo lwe-electromagnetic (EMI), intsimi ye-electromagnetic (EMF) kunye nokuphazamiseka kwamaza omoya (RFI). Lo mmiselo unokuqinisekisa ukusebenza kwesixhobo kunye nezinye izixhobo ezikufutshane. I-EMC inyanzelisa imida engqongqo kwisixa samandla esinokusasazeka okanye sidluliselwe sisuka kwesinye isixhobo sisiya kwesinye, kwaye siyilelwe ukunciphisa ukubakho kwe-EMF yangaphandle, i-EMI, i-RFI, njalo njalo. Ngamanye amagama, injongo yalo mmiselo kukuthintela amandla ombane ukungangeni okanye ukuphuma kweso sixhobo. Le yingxaki enzima kakhulu ukuyisombulula, kwaye ihlala isonjululwa ngokusebenzisa amandla kunye nokubeka iziseko, okanye ukubeka iPCBS kwiibhokisi zentsimbi. The power and ground layers protect the signal layer from interference, and the metal box works equally well. Asiyi kude kakhulu kule micimbi.

Isantya esiphezulu sesekethe sixhomekeke ekuthobeleni i-EMC. I-EMI yangaphakathi, efana nelahleko yangoku phakathi kwabaqhubi, inyuka njengoko kunyuka rhoqo. Ukuba umahluko okhoyo phakathi kwezi zibini mkhulu kakhulu, qiniseka ukwandisa umgama phakathi kwabo. This also tells us how to avoid high voltage and minimize the current consumption of the circuit. Ireyithi yokulibaziseka kwentambo ikwabalulekile, ke ngokufutshane ngobude, kungcono. Ke i-PCB encinci ene-wiring elungileyo iya kusebenza ngcono ngesantya esiphezulu kune-PCB enkulu.