Ekuqaleni komklamo omusha, isikhathi esiningi besichithwa ekwakhiweni kwesekethe nokukhethwa kwezinto, kanye ne PCB ukwakheka nesiteji sokwenziwa kwentambo bekungajwayele ukubhekwa njengokuqondisisa ngenxa yokushoda kolwazi. Ukwehluleka ukunikela ngesikhathi esanele nomzamo ekwakhiweni kwe-PCB nasekwenzeni umzila wedizayini kungaholela ezinkingeni esiteji sokukhiqiza noma ukukhubazeka okusebenzayo lapho ukwakhiwa kuguqulwa kusuka kusizinda sedijithali kuya kokungokoqobo okungokoqobo. Ngakho-ke uyini ukhiye wokuqamba ibhodi lesifunda eliyiqiniso kokubili ephepheni nasekwimo yomzimba? Ake sihlole imihlahlandlela emihlanu ephezulu yokwakhiwa kwe-PCB ukuze sazi lapho siklama i-PCB ekhiqizwayo, esebenzayo.

1 – Hlela kahle ukwakheka kwengxenye yakho

Isigaba sokubekwa kwengxenye yenqubo yokuhlelwa kwe-PCB sobabili yisayensi nobuciko, esidinga ukubhekwa ngamasu wezinto eziyinhloko ezitholakala ebhodini. Ngenkathi le nqubo ingaba yinselele, indlela obeka ngayo i-elekthronikhi izonquma ukuthi kulula kangakanani ukwenza ibhodi lakho nokuthi lihlangabezana kahle kanjani nezidingo zakho zokuqala zedizayini.

Ngenkathi kukhona ukuhleleka okujwayelekile kokufakwa kwezinto, njengokufakwa kwezixhumi ngokulandelana, izinto zokufaka ze-PCB, amasekethe kagesi, amasekethe wokunemba, amasekethe abucayi, njll.

Ukuzijwayeza – Ukuqinisekisa ukuthi izinto ezifanayo zibekwe ohlangothini olufanayo kuzosiza ekufezeni inqubo yokuwelda esebenza kahle futhi engenamaphutha.

Ukubekwa – Gwema ukubeka izinto ezincane ngemuva kwezinto ezinkulu lapho zingathinteka khona ngokufaka okokufaka okuthile okukhudlwana.

Inhlangano – Kunconywa ukuthi zonke izingxenye ze-surface mount (SMT) zibekwe ohlangothini olufanayo lwebhodi futhi zonke izingxenye zemigodi (TH) zibekwe ngaphezulu kwebhodi ukunciphisa izinyathelo zomhlangano.

Umhlahlandlela wokugcina wokuklama we-PCB – lapho usebenzisa izinto zobuchwepheshe ezixubekile (izingxenye zomgodi nezingaphezulu), umenzi angadinga izinqubo ezengeziwe zokuhlanganisa ibhodi, elizokwengeza ezindlekweni zakho zizonke.

Ukuma okuhle kwento ye-chip (kwesobunxele) nokuma okungalungile kwento ye-chip (kwesokudla)

Ukubekwa kwengxenye enhle (kwesobunxele) nokubekwa kwengxenye embi (kwesokudla)

Cha. 2 – Ukubekwa kahle kwamandla, ukubekwa phansi kanye nokuxhunywa kwesiginali

Ngemuva kokubeka izinto, ungabeka ukunikezwa kwamandla, ukugxusha, nokuxhuma izintambo ukuqinisekisa ukuthi isiginali yakho inendlela ehlanzekile, engenazinkinga. Kulesi sigaba senqubo yokuhlelwa, gcina imihlahlandlela elandelayo engqondweni:

Thola ukunikezwa kwamandla nezendlalelo zendiza

Kuhlala kunconywa ukuthi ukufakwa kwamandla kanye nezendlalelo zezindiza zomhlaba zifakwe ngaphakathi kwebhodi ngenkathi zilingana futhi zigxile. Lokhu kusiza ukuvimbela ibhodi lakho lesifunda ekugoqeni, nakho okubalulekile uma izingxenye zakho zibekwe kahle. Ukuze unike amandla i-IC, kunconywa ukuthi usebenzise isiteshi esivamile sokuphakelwa kwamandla ngakunye, uqinisekise ububanzi bezintambo obuqinile futhi obuzinzile, futhi ugweme ukuxhumana kwamandla kaDaisy kocingo nedivayisi.

Izintambo zesiginali zixhunywe ngezintambo

Okulandelayo, xhuma umugqa wesiginali ngokuya ngomklamo kumdwebo wesikimu. Kunconywa ukuthi uhlale uthatha indlela emfushane kakhulu futhi uqonde ngqo phakathi kwezinto. Uma izingxenye zakho zidinga ukubekwa ngokuvundlile ngaphandle kokuchema, kunconywa ukuthi ngokuqinile uthinte izingxenye zebhodi ngokuvundlile lapho ziphuma khona ocingweni bese uzifaka zibheke ngocingo ngemuva kokuphuma kocingo. Lokhu kuzobamba ingxenye endaweni evundlile njengoba i-solder ifuduka ngesikhathi sokushisela. Njengoba kukhonjisiwe engxenyeni engenhla yesibalo esingezansi. Intambo yesiginali ekhonjiswe engxenyeni engezansi yesibalo ingadala ukuphambuka kwengxenye njengoba i-solder igeleza ngesikhathi sokushisela.

Ukuncoma izintambo (imicibisholo ikhomba ukuqondiswa kokugeleza kwe-solder)

Izintambo ezinganconyiwe (imicibisholo ibonisa ukuqondisa kokugeleza kwe-solder)

Chaza ububanzi benethiwekhi

Idizayini yakho ingadinga amanethiwekhi ahlukile azothwala imisinga eyahlukahlukene, ezonquma ububanzi benethiwekhi obudingekayo. Uma ucabanga ngale mfuneko eyisisekelo, kunconywa ukuthi unikeze ububanzi obungu-0.010 “(10mil) bezimpawu zamanje eziphansi ze-analog nezedijithali. Lapho umugqa wakho wamanje weqa ama-ampera ayi-0.3, kufanele unwetshwe. Nayi indawo yokubala yobubanzi bolayini wamahhala ukwenza inqubo yokuguqula ibe lula.

Inombolo yesithathu. – Ukuhlukaniswa okusebenzayo

Mhlawumbe uke wazibonela ukuthi amandla amakhulu nama-spikes wamanje kumasekethe wokuphakelwa kwamandla angaphazamisa kanjani amasekethe wakho wokulawula amandla aphansi. Ukunciphisa izinkinga ezinjalo zokuphazamiseka, landela imihlahlandlela elandelayo:

Ukuhlukaniswa – Qinisekisa ukuthi umthombo ngamunye wamandla ugcinwa uhlukile kumthombo wamandla nomthombo wokulawula. Uma kufanele uwaxhume ndawonye ku-PCB, qiniseka ukuthi isondele ekugcineni kwendlela yamandla ngangokunokwenzeka.

Isakhiwo – Uma ngabe ubeke indiza yaphansi ohlangothini oluphakathi, qiniseka ukuthi ubeka indlela encane ye-impedance ukunciphisa ubungozi bokuphazanyiswa kwesekethe yamandla futhi usize ukuvikela isignali yakho yokulawula. Imihlahlandlela efanayo ingalandelwa ukugcina i-digital ne-analog yakho ihlukile.

Ukubhangqa – Ukunciphisa ukuhlangana kwe-capacitive ngenxa yokubeka izindiza ezinkulu zomhlaba kanye ne-wiring ngaphezulu nangaphansi kwazo, zama ukuwela ulingise umhlaba kuphela ngemigqa yesiginali ye-analog.

Izibonelo zokuhlukaniswa ngento (i-digital ne-analog)

Cha. 4 – Xazulula inkinga yokushisa

Wake waba nokuwohloka kokusebenza kwesifunda noma ukulimala kwebhodi lesifunda ngenxa yezinkinga zokushisa? Ngoba akukho ukucatshangelwa kokushabalalisa ukushisa, kube nezinkinga eziningi ezikhungethe abaklami abaningi. Nayi eminye imihlahlandlela okufanele uyikhumbule ukusiza ukuxazulula izinkinga zokushabalalisa ukushisa:

Khomba izingxenye ezinenkinga

Isinyathelo sokuqala ukuqala ukucabanga ukuthi yiziphi izingxenye ezizokhipha ukushisa okukhulu okuvela ebhodini. Lokhu kungenziwa ngokuthola kuqala izinga “lokumelana nokushisa” eshidini ledatha lalokho bese ulandela imihlahlandlela ephakanyisiwe yokudlulisa ukushisa okwenziwe. Vele, ungangeza ama-radiator nabalandeli bokupholisa ukugcina izinto zipholile, futhi khumbula ukugcina izinto ezibucayi kude nanoma iyiphi imithombo yokushisa ephezulu.

Faka amapayipi omoya ashisayo

Ukwengezwa kwamaphayiphu omoya ashisayo kuyasiza kakhulu kumabhodi wesifunda angenzelwayo, abalulekile ezingxenyeni zokuqukethwe zethusi eziphakeme kanye nasekusebenziseni ama-wave soldering kumabhodi wesifunda ama-multilayer. Ngenxa yobunzima bokugcina ukushisa kwenqubo, kuhlala kunconywa ukusebenzisa amapayipi omoya ashisayo ezintweni ezihamba ngembobo ukwenza inqubo yokushisela ibe lula ngangokunokwenzeka ngokunciphisa izinga lokushabalalisa ukushisa ezikhonkwaneni zezinto.

Njengomthetho ojwayelekile, hlala uxhuma noma iyiphi imbobo noma imbobo exhunywe phansi noma indiza yamandla usebenzisa iphedi yomoya eshisayo. Ngokungeziwe kumaphakethe womoya oshisayo, ungangeza futhi amathonsi wezinyembezi lapho kutholakala khona ulayini wokuxhuma wepedi ukuze unikeze ukusekelwa okwengeziwe kwe-foil / ukwesekwa kwensimbi. Lokhu kuzosiza ekunciphiseni ukucindezela komshini nokushisa.

Ukuxhuma okujwayelekile kwephedi lomoya elishisayo

Isayensi yomoya eshisayo:

Onjiniyela abaningi abaphethe i-Process noma i-SMT efektri bavame ukuhlangana namandla kagesi wokuzenzakalela, njengokukhubazeka kwebhodi kagesi njengokuzenzakalela okungenalutho okuzenzekelayo, ukumisa phansi, noma ukumanzisa okubandayo. Akunandaba ukuthi ungaziguqula kanjani izimo zenqubo noma uvuselele ukushisa kwesithando somlilo ukuthi ungalungisa kanjani, kunengxenye ethile yethini ayikwazi ukugoqwa. Kwenzekani lapha?

Ngaphandle nje kwezakhi nezinkinga zamabhodi wesifunda, phenya ukubuya kwayo ngemuva kwengxenye enkulu kakhulu ye-welding esivele ikhona empeleni ivela kumklamo webhodi yesifunda (ukwakheka) ayikho, futhi okunye okuvame kakhulu kungxenyeni ye izinyawo zokushisela ezithile zixhunywe kushidi lethusi lendawo enkulu, lezi zingxenye ngemuva kokwenza kabusha izinyawo zokushisela i-soldering Ezinye izinto ezishiselwe ngesandla zingadala nezinkinga zokushisela okungekho emthethweni noma ukumboza ngenxa yezimo ezifanayo, kanti ezinye zize zehluleke ukuzishisela izingxenye ngenxa yokushisa okude kakhulu.

I-PCB ejwayelekile ekwakhiweni kwesifunda imvamisa idinga ukubeka indawo enkulu yocingo lwethusi njengokunikezwa kwamandla (i-Vcc, i-Vdd noma i-Vss) ne-Ground (GND, Ground). Lezi zindawo ezinkulu zocwecwe lwethusi ngokuvamile zixhunywe ngqo kumasekhethi athile wokulawula (i-ICS) nezikhonkwane zezinto ezisebenza ngogesi.

Ngeshwa, uma sifuna ukufudumeza lezi zindawo ezinkulu zoqweqwe lwethusi ekushiseni kwethini elincibilikayo, kuvame ukuthatha isikhathi esiningi kunamaphakethe (ukushisa kuhamba kancane), futhi ukushisa kokushisa kuyashesha. Lapho ukuphela okukodwa kwentambo enkulu yocingo yethusi kuxhunywe ezingxenyeni ezincane njengokumelana okuncane kanye namandla amancane, kanti omunye umkhawulo awunjalo, kulula ukuxhuma izinkinga ngenxa yokungahambelani kokuncibilika kothayela nesikhathi sokuqina; Uma ijika lokushisa le-welding reflow lingalungiswa kahle, futhi isikhathi sokufudumeza asanele, izinyawo ze-solder zalezi zinto ezixhunywe ocingweni olukhulu lwethusi kulula ukudala inkinga yokushisela okubonakalayo ngoba abakwazi ukufinyelela izinga lokushisa le-tin.

Ngesikhathi sokufaka isandla ngesandla, amalunga we-solder wezinto ezixhunywe kumafreyimu amakhulu ethusi azohamba ngokushesha okukhulu ukuqeda ngesikhathi esidingekayo. Amaphutha ajwayelekile kakhulu yi-soldering kanye ne-virtual soldering, lapho i-solder ifakwe kuphela kuphini lwento futhi ingaxhunywanga kuphedi lebhodi lesifunda. Kusukela ekubukekeni, ilunga lonke le-solder lizokwakha ibhola; Ngaphezu kwalokho, u-opharetha ukuze ashise izinyawo zokushisela ebhodini lesifunda futhi akhuphule njalo izinga lokushisa lensimbi okunamathisela ngomthofu, noma ukufudumeza isikhathi eside kakhulu, ukuze izingxenye zidlule ukushisa kokumelana nokushisa nomonakalo ngaphandle kokwazi. Njengoba kukhonjisiwe esithombeni esingezansi.

Njengoba silazi iphuzu lenkinga, singayixazulula inkinga. Ngokuvamile, sidinga lokho okubizwa ngokuthi yi-Thermal Relief pad design ukuxazulula inkinga yokushisela ebangelwa izinyawo zokushisela zezinto ezinkulu ezixhuma ucwecwe lwethusi. Njengoba kukhonjisiwe esithombeni esingezansi, i-wiring ngakwesobunxele ayisebenzisi iphedi lomoya elishisayo, ngenkathi izintambo ezingakwesokudla zamukele ukuxhumana okushisayo kwephedi yomoya. Kungabonakala ukuthi kunemigqa embalwa kuphela endaweni yokuxhumana phakathi kwephedi nefilili enkulu yethusi, engakhawulela kakhulu ukulahleka kwezinga lokushisa ephepheni futhi ifinyelele umphumela omuhle wokushisela.

Cha. 5 – Hlola umsebenzi wakho

Kulula ukuzizwa ukhungathekile ekugcineni kwephrojekthi yokwakha lapho ugoqa futhi ukhukhumeza zonke izingcezu ndawonye. Ngakho-ke, ukubheka kabili nokuphindwe kathathu umzamo wakho wokuklama kulesi sigaba kungasho umehluko phakathi kwempumelelo yokukhiqiza nokwehluleka.

Ukusiza ukuqedela inqubo yokulawulwa kwekhwalithi, sihlala sincoma ukuthi uqale ngokuhlolwa kwe-Rule Rule (ERC) kanye ne-design Rule check (DRC) ukuqinisekisa ukuthi umklamo wakho uhlangabezana ngokugcwele nayo yonke imithetho nezingqinamba. Ngazo zombili lezi zinhlelo, ungabheka kalula ububanzi bemvume, ububanzi bomugqa, izilungiselelo ezivamile zokukhiqiza, izidingo zejubane eliphezulu namasekhethi amafushane.

Lapho i-ERC ne-DRC yakho ikhiqiza imiphumela engenamaphutha, kunconywa ukuthi ubheke ukuxhunywa kwesiginali ngayinye, kusuka kuhlelo kuya ku-PCB, ulayini owodwa wesiginali ngesikhathi ukuqinisekisa ukuthi awuphuthelwa yiluphi ulwazi. Futhi, sebenzisa amandla okuphenya amathuluzi wakho wokuklama ukuqinisekisa ukuthi impahla yakho yokuhlelwa kwe-PCB ifana nesikimu sakho.