Kwinkqubo yoyilo kunye nemveliso ye-PCB, iinjineli azifuneki kuphela ukuthintela iingozi ngexesha lokwenziwa kwePCB, kodwa kufuneka ziphephe iimpazamo zoyilo. Eli nqaku lishwankathela kwaye lihlalutya ezi ngxaki zePCB eziqhelekileyo, ngethemba lokuzisa uncedo kuyilo kunye nomsebenzi wokuvelisa.
Ingxaki 1: Ibhodi yePCB yesekethe emfutshane
Le ngxaki yenye yeempazamo eziqhelekileyo eziya kubangela ngokuthe ngqo ukuba ibhodi yePCB ingasebenzi, kwaye kukho izizathu ezininzi zale ngxaki. Makhe sihlalutye nganye nganye ngezantsi.
Oyena nobangela mkhulu wesekethe emfutshane ye-PCB kuyilo lwephedi ye-solder engafanelekanga. Ngeli xesha, i-solder pad ejikelezayo ingatshintshwa ibe yimo ye-oval ukunyusa umgama phakathi kwamanqaku ukuthintela imijikelezo emfutshane.
Uyilo olungafanelekanga lwesalathiso samalungu e-PCB luya kubangela ukuba ibhodi ibe yifutshane kwaye isilele ukusebenza. Umzekelo, ukuba iphini ye-SOIC ihambelana ne-tin wave, kulula ukwenza ingozi yesiphaluka esifutshane. Ngeli xesha, ulwalathiso lwenxalenye lunokuguqulwa ngokufanelekileyo ukuze luyenze i-perpendicular kumaza e-tin.
Kukho enye into enokwenzeka eya kubangela ukusilela kwesekethe emfutshane yePCB, oko kukuthi, unyawo olugobileyo lweplug-in. Njengoko i-IPC ichaza ukuba ubude bepini bungaphantsi kwe-2mm kwaye kukho inkxalabo yokuba iindawo ziya kuwa xa i-angle yomlenze ogobileyo inkulu kakhulu, kulula ukubangela isiphaluka esifutshane, kwaye i-solder joint kufuneka ibe ngaphezu kwe-2. 2mm kude nesekethe.
Ukongeza kwezi zizathu zithathu zikhankanywe ngasentla, kukho kwakhona ezinye izizathu ezinokubangela ukusilela kwisekethe emfutshane yebhodi ye-PCB, njengemingxuma enkulu kakhulu ye-substrate, ubushushu obuphantsi kakhulu beziko le-tin, ukuthengiswa kakubi kwebhodi, ukusilela kwe-solder mask. , kunye nebhodi Ungcoliseko loMphezulu, njl., zizinto eziqhelekileyo ezibangela ukusilela. Iinjineli zinokuthelekisa ezi zizathu zingasentla kunye nesehlo sokungaphumeleli ukuphelisa kunye nokukhangela nganye nganye.
Ingxaki yesi-2: Abafowunelwa abamnyama nabaneenkozo bavela kwibhodi yePCB
Ingxaki yombala omnyama okanye amalungu amancinci amancinci kwi-PCB ininzi ngenxa yokungcoliswa kwe-solder kunye nee-oxides ezigqithisileyo ezixutywe kwi-tin etyhidiweyo, ezenza i-solder joint structure is too brittle. Qaphela ukuba ungayibhidanisi nombala omnyama obangelwa ukusebenzisa i-solder enomxholo we-tin ephantsi.
Esinye isizathu sale ngxaki kukuba ukubunjwa kwe-solder esetyenziswe kwinkqubo yokuvelisa kutshintshile, kwaye umxholo wokungcola uphezulu kakhulu. Kuyimfuneko ukongeza i-tin ecocekileyo okanye indawo ye-solder. Iglasi engcolileyo ibangela utshintsho olubonakalayo kwi-fiber build-up, njengokwahlula phakathi kweeleya. Kodwa le meko ayikho ngenxa yokungahambi kakuhle kwe-solder. Isizathu kukuba i-substrate ishushu kakhulu, ngoko kuyimfuneko ukunciphisa ukushisa kwangaphambili kunye ne-soldering okanye ukwandisa isantya se-substrate.
Ingxaki yesithathu: Amalungu e-solder e-PCB abe bugolide tyheli
Phantsi kweemeko eziqhelekileyo, i-solder kwibhodi ye-PCB yisilivere engwevu, kodwa ngamanye amaxesha i-golden solder joints ibonakala. Esona sizathu siphambili sale ngxaki kukuba iqondo lobushushu liphezulu kakhulu. Ngeli xesha, kufuneka unciphise kuphela ukushisa kwesithando somlilo.
Umbuzo 4: Ibhodi embi nayo ichatshazelwa kokusingqongileyo
Ngenxa yolwakhiwo lwePCB ngokwayo, kulula ukwenza umonakalo kwiPCB xa ikwimo engathandekiyo. Ukushisa okugqithisileyo okanye ukushisa okuguquguqukayo, ukufuma okugqithisileyo, ukunyakaza okuphezulu kunye nezinye iimeko zizinto zonke ezibangela ukuba ukusebenza kwebhodi kuncitshiswe okanye kukhutshwe. Ngokomzekelo, utshintsho kwiqondo lokushisa elisezantsi luya kubangela ukuguqulwa kwebhodi. Ngoko ke, iintambo ze-solder ziya kutshatyalaliswa, ibhodi yebhodi iya kugoba, okanye imikhondo yobhedu ebhodini ingaphulwa.
Ngakolunye uhlangothi, ukufuma emoyeni kunokubangela i-oxidation, i-corrosion kunye ne-rust kwiindawo zetsimbi, ezifana ne-trace copper eveziweyo, i-solder joints, iipads kunye ne-component lead. Ukuqokelelana kokungcola, uthuli, okanye inkunkuma kumphezulu wamacandelo kunye neebhodi zesekethe kunokunciphisa ukuhamba komoya kunye nokupholisa kwamalungu, okubangela ukufudumeza kwePCB kunye nokwehla kokusebenza. Ukungcangcazela, ukuwisa, ukubetha okanye ukugoba i-PCB kuya kuyikhubaza kwaye kubangele ukuba kubonakale ukuqhekeka, ngelixa i-high current okanye i-overvoltage iya kubangela ukuba i-PCB iphulwe okanye ibangele ukuguga ngokukhawuleza kwamacandelo kunye neendlela.
Ingxaki yesihlanu: I-PCB evulekileyo yesekethe
Xa umkhondo uphukile, okanye xa i-solder ikwi-pad kuphela kwaye ingekho kwinqanaba elikhokelela, isiphaluka esivulekile singenzeka. Kule meko, akukho kunamathela okanye unxibelelwano phakathi kwecandelo kunye nePCB. Njengeesekethe ezimfutshane, ezi zinokuthi zenzeke ngexesha lemveliso okanye ukuwelda kunye neminye imisebenzi. Ukushukuma okanye ukunweba kwebhodi yesiphaluka, ukuwayeka okanye ezinye izinto zokuguqulwa komatshini ziya kutshabalalisa umkhondo okanye i-solder joints. Ngokufanayo, iikhemikhali okanye ukufuma kunokubangela ukuba i-solder okanye iinxalenye zetsimbi zinxibe, ezinokubangela ukuba icandelo likhokelela ekuphuleni.
Ingxaki yesithandathu: iinxalenye ezikhululekileyo okanye ezilahlekileyo
Ngexesha lenkqubo yokubuyisela kwakhona, iindawo ezincinci zinokudada kwi-solder etyhidiweyo kwaye ekugqibeleni ziyishiye ijoyinti ye-solder ekujoliswe kuyo. Izizathu ezinokwenzeka zokufuduka okanye ukuthambeka ziquka ukungcangcazela okanye ukugxumeka kwamacandelo kwibhodi ye-PCB ethengisiweyo ngenxa yenkxaso enganeleyo yebhodi yesekethe, izicwangciso ze-oven reflow, iingxaki ze-solder paste, kunye nempazamo yomntu.
Ingxaki yesixhenxe: ingxaki ye-welding
Ezi zilandelayo zezinye zeengxaki ezibangelwa kukungasebenzi kakuhle kwe-welding:
Ukuphazamiseka kwe-solder joints: I-solder ihamba phambi kokuqina ngenxa yokuphazamiseka kwangaphandle. Oku kufana neendawo ezibandayo ze-solder, kodwa isizathu sahlukile. Inokulungiswa ngokufudumeza kwakhona kwaye uqinisekise ukuba i-solder joints ayiphazanyiswa ngaphandle xa ipholile.
I-Cold welding: Le meko iyenzeka xa i-solder ingakwazi ukunyibilika ngokufanelekileyo, okubangelwa iindawo ezinqabileyo kunye nokudibanisa okungathembekiyo. Ekubeni i-solder egqithisileyo ithintela ukunyibilika okupheleleyo, amajoyina abandayo anokuthi avele. Isilungiso kukubuyisela ukudibanisa kunye nokususa i-solder engaphezulu.
Ibhulorho ye-Solder: Oku kwenzeka xa i-solder iwela kwaye idibanisa ngokomzimba iinkokeli ezimbini kunye. Ezi zinokwenza udibaniso olungalindelekanga kunye neesekethe ezimfutshane, ezinokubangela ukuba amacandelo atshise okanye atshise imikhondo xa umsinga uphezulu kakhulu.
I-Pad: Ukumanzisa okungonelanga kwelothe okanye ilothe. I-solder eninzi kakhulu okanye encinci kakhulu. Iipads eziphakanyisiweyo ngenxa yokushisa kakhulu okanye i-soldering erhabaxa.
Ingxaki yesibhozo: impazamo yomntu
Uninzi lweziphene kwimveliso ye-PCB zibangelwa yimpazamo yomntu. Kwiimeko ezininzi, iinkqubo zokuvelisa ezingalunganga, ukubekwa ngendlela engafanelekanga kwamacandelo kunye neenkcukacha zokuvelisa ezingenamsebenzi zingabangela ukuya kwi-64% yeziphene zemveliso eziphephekayo. Ngenxa yezi zizathu zilandelayo, amathuba okubangela iziphene ayanda kunye nobunzima besiphaluka kunye nenani leenkqubo zokuvelisa: amacandelo ahlanganiswe ngokuxineneyo; iileya zesekethe ezininzi; iingcingo ezicolekileyo; amacandelo e-soldering; amandla kunye neenqwelomoya zomhlaba.
Nangona wonke umenzi okanye umhlanganisi unethemba lokuba ibhodi ye-PCB eveliswayo ayinaziphene, kodwa kukho iingxaki ezininzi zoyilo kunye nenkqubo yokuvelisa ezibangela iingxaki eziqhubekayo zebhodi ye-PCB.
Iingxaki eziqhelekileyo kunye neziphumo zibandakanya ezi ngongoma zilandelayo: i-solder engafanelekanga ingakhokelela kwiisekethe ezimfutshane, iisekethe ezivulekileyo, i-cold solder joints, njl.; ukungahambi kakuhle kweeleyile zebhodi kunokukhokelela ekudibaneni kakubi kunye nokusebenza kakubi ngokubanzi; I-insulation embi yeendlela zethusi kunokukhokelela kwimizila kunye neempawu Kukho i-arc phakathi kweengcingo; ukuba imikhondo yobhedu ibekwe ngokuqinileyo phakathi kwe-vias, kukho umngcipheko wesiphaluka esifutshane; ubukhulu obunganeleyo bebhodi yesiphaluka buya kubangela ukugoba kunye nokuphuka.