Ukubaluleka koKhetho lweSubstrate yePCB kuYilo lweMveliso yoMbane

  Iimpawu ezininzi ze-PCB zigqitywa yi-substrate. Ukukhetha okungafanelekanga kwe-substrate akuyi kuchaphazela kuphela ezinye iimpawu zeemveliso. Okufana nokumelana nobushushu, ubushushu bokusebenza kwemveliso, ukumelana nokugquma, ilahleko ye-dielectric, njl. Ngoko ke, ukuqonda iimpawu ze-PCB substrate, ukukhetha i-substrate kunye nokukhetha i-substrate ngokufanelekileyo ngomnye wemixholo ebalulekileyo yoyilo lwe-pcb.

  Nangona kunjalo, abaninzi abayili bePCB bakhethekileyo kuyilo lwesekethe. Abanye abaqulunqi be-PCB bakholelwa ukuba ukukhethwa kwe-substrate ngumbandela wenkqubo yokuvelisa i-PCB, ukungahoywa inqaku elibalulekileyo lokuba iinkcukacha zoyilo kufuneka zikhethwe ngokwemeko yenkqubo yemveliso. Ngenxa yoko, iimveliso ezilungiselelweyo azikwazi ukuhlangabezana neemfuno zenkqubo yokuvelisa ngobuninzi. Abasebenzi benkqubo yefektri ngamanye amaxesha abanalo ulwazi olwaneleyo lwezixhobo zePCB, okukhokelela ekukhethweni okungafanelekanga kweenkqubo zokuwelda ezihambelanayo kwimveliso, okukhokelela ekukhutshelweni kobuninzi beemveliso okanye iingxaki ezibalulekileyo zomgangatho wokuwelda.

  Eli phepha lihlalutya ngokufutshane iimpawu ze-PCB substrate esetyenziswa kushishino lwemveliso ye-elektroniki ngokubanzi kunye nokusebenza kwayo kwiinkqubo ezahlukeneyo zemveliso ngokukhankanya iingxaki ezifunyenwe kwiiprojekthi zoyilo zoqobo.

  Ngokuqonda ngakumbi inkqubo yokuvelisa, siyazi ukuba ngenxa yokuba le bhodi iyiphaneli enye kwaye ineemfuno zendibano ye-plug-ins kunye nezixhobo zokukhwela umphezulu, umzi-mveliso uye waphumeza inkqubo yokuqala yokusebenzisa i-reflow soldering kwi-weld surface Mount izixhobo, kwaye emva koko sebenzisa i-solder ye-wave. Ubushushu obumiselweyo bokuphinda kufakwe i-solder iyafuneka ukuze kuhlangatyezwane neemfuno zenkqubo yokufakwa kwe-lead-free soldering, kwaye ubushushu be-avareji ephezulu ye-welding iphezulu njenge-239 ℃. Ukusetwa kwenkqubo yayo yetekhnoloji idibana ngokupheleleyo nomgangatho wetekhnoloji wokuthengisela okungekho lead, kodwa ayihoywa eyona nto ibalulekileyo, eyingxaki yezinto zePCB. Ngokuphononongwa ngononophelo kwamaxwebhu oyilo lwe-PCB, safunda ukuba abaqulunqi bakhetha izinto ze-FR-1 kunye neendleko ezihambelanayo, ngokuqwalasela ukuba ukusebenza kombane ekufuneka le bhodi yesekethe ihlangabezane nayo kulula ekuqaleni koyilo. Kwaye FR1. Ayinakukwazi ukumelana nobushushu obuphezulu be-217 ℃ nangaphezulu kwindawo yokuqukuqela yenkqubo yokuthengisela i-lead-free reflow soldering ye-60 ukuya kwi-80 imizuzwana. Ukongezelela, izinto ngokwazo zilula ukufumana umswakama, ngoko ke i-popcorn phenomenon iyenzeka. Emva kokumisela unobangela wengxaki, uZhoumen ulungelelanise inkqubo yokuvelisa ukuba: icala elinye lokukhupha, ukunyanga, ukuthambisa amaza ukugqiba ukuwelda kwazo zonke izixhobo, apho ukunyangwa kweglue ebomvu kuphunyezwa yinkqubo yeedigri ezingama-120 kunye nemizuzwana eyi-120. Into yepopcorn ayizange iphinde yenzeke emva kokuveliswa kovavanyo

Ngokubanzi, iphepha le-FR4 lisetyenziswa kakhulu kwiimveliso ezininzi ze-elektroniki zabathengi, kwaye liyaziwa ngabayili abaninzi kunye neengcali zefektri. Emva koko siza kwazisa iintlobo, iipropati kunye neenkqubo ezifanelekileyo ze-substrates zebhodi yesekethe ezifunyanwa rhoqo yiZhoumen nganye nganye.

  Kukho iintlobo ezininzi ze-substrates ezisetyenziselwa i-PCB, kunye ne-CCL (i-copper clad laminate) yeyona nto ibalulekileyo yokuvelisa i-PCB. Ngokweentlobo zezixhobo zokuqinisa ezisetyenzisiweyo, zihlulwe ngokukodwa zibe ngamacandelo amane: iphepha elisekelwe, i-glass fiber cloth esekelwe, i-composite esekelwe kunye nesiseko sesinyithi. Kwiimveliso zethu ze-elektroniki zemihla ngemihla, isiseko sephepha kunye nelaphu leglasi lisetyenziswa kakhulu.

  I-substrate yephepha luhlobo lwe-laminate ene-copper-clad eqiniswe nge-fiber paper efakwe kwi-phenolic okanye i-epoxy resin. Kwi-CCL esekwe kwiphepha, amabanga aqhelekileyo ngala XPC, XXXPC, FR1, FR2, FR3, njl.

  Ngenxa yokukhululeka kwephepha, liyakwazi ukugqobhoza imingxuma kuphela, lingagqobhozi imingxuma ekusetyenzweni kwayo. Ukongeza, inokufakwa okuphezulu kwamanzi, ngoko ke i-substrate yephepha ngokubanzi ifanelekile kuphela ukwenza ipaneli enye. Ngenxa ye-coefficient enkulu yokwandiswa kwe-thermal kwindlela ye-z ye-substrate esekelwe ephepheni, ukutshintshwa kweqondo lokushisa kuya kukhokelela ekuqhekekeni kwemingxuma ene-metalized kunye ne-solder joints. Ngokuqhelekileyo akukhuthazwa ukusebenzisa i-metallised through-hole xa ukhetha imathiriyeli esisiseko yoyilo

  Ngokubanzi, izinto ezingalunganga eziphambili zezixhobo ezisekelwe ephepheni ngamandla abo omzimba, ukunganyangeki kwempembelelo embi, ukungazinzi komgangatho wezinto eziphathekayo, iipropati ze-dielectric ezingazinzanga kunye nomonakalo olula. Iingenelo zayo kubuchule bayo bokubethelela, ixabiso eliphantsi, kunye nokusebenza kombane kunokuhlangabezana neemfuno zoyilo lweemveliso zombane ezingafunwayo ngokubanzi. Phakathi kwabo, ukuqhutyelwa kwe-punching kwenza uqoqosho lokucubungula lweemveliso ezisekelwe ephepheni eziveliswe kwiibhetshi zivelele ngakumbi

  Ngokubhekiselele ekuxhathiseni ubushushu, ukuxhathisa ubushushu kuzo zonke izinto ezisisiseko sephepha diphu imiphezulu edityanisiweyo enobunzima obungaphezulu kwe-1.6 μ m iya kuhlangabezana nemfuneko yenkqubo yokungaqheleki kwe-5s kwi-260 ℃, kunye nokumelana nobushushu emoyeni kuya kuhlangabezana novavanyo. imeko yokungabikho kweqamza kwi-120 ℃ imizuzu engama-30. Ngokusekwe kwezi mpawu zingasentla, ezo substrates zinokuhlangabezana ngokubanzi neemeko ze-welding of soldering wave, dispensing and heal. Ngenxa yobushushu obuphezulu kunye nobude be-lead-free reflow soldering, ezo ndawo zisezantsi azifanelekanga ukuphinda zifakwe kwi-solder.

I-CCL esekelwe kwilaphu leglasi yilamineti egqunywe ngekopolo eqiniswe ngelaphu lefayibha yeglasi efakwe i-resin. Amanqanaba aqhelekileyo aqhelekileyo yi-G10, G11, FR4 kunye ne-FR5. I- FR4 epoxy glass cloth fiberboard (FR4 epoxy/E glass fiber) isetyenzisiwe iminyaka emininzi, kwaye ibonakalisiwe njengeyona nto iphumelele kakhulu esetyenziswa kakhulu kushishino lwebhodi yesekethe. Kwezinye iimveliso kwicandelo le-high-frequency, xa ilaphu eliqhelekileyo lefayibha yeglasi ye-FR4 epoxy lingasakwazi ukuhlangabezana neemfuno zokusebenza kwemveliso, i-epoxy resin esebenzayo ephezulu kunye nelaphu leglasi le-polyphthalimide ziye zaphuhliswa kwaye zasetyenziswa. Ezinye izinto ze-resin ziquka i-bismaleimide modified triazine resin (BT), i-diphenylene ether resin (PPO), i-maleic anhydride imine styrene resin (MS), i-polycyanate resin Ngokuphathelele izinto zokuqinisa ezifana ne-polyolefin resin, izinto ezihlangabezana nokusebenza okuphezulu ziquka i-S glass fiber, i-D glass fiber, njl.

  Kwiimveliso ze-elektroniki eziqhelekileyo ngaphandle kweemfuno ezikhethekileyo, izinto ze-FR4 ezinokushisa kweglasi ye-130 ukuya kwi-140 zingasetyenziswa. I-dielectric constant ngokuqhelekileyo iphakathi kwe-4.5 kunye ne-5.4. Kwi-substrates eqinile, encinci i-resin content, iphezulu i-dielectric constant

Ukuze uhlangabezane neemfuno zokumelana nobushushu obuphezulu bebhodi yesekethe, kuyimfuneko ukukhetha i-epoxy resin material ye-170 ukuya kwi-180 ℃. Olu hlobo lwezinto ezisisiseko lunozinzo olungcono lwe-dimensional, ngoko lusetyenziswa ikakhulu kwi-BGA, i-TAB kunye noyilo olufuna ukuwelda kobushushu obuphezulu kwindibano, njengokunyuswa komphezulu ngamacala amabini.

Ngokubanzi, iphepha le-fiberglass eliqinileyo le-FR4 epoxy linamandla aphezulu oomatshini, linokucutshungulwa kakuhle kwaye linokubholwa kakuhle, kunye nokuzinza kwalo okuhle, ukufunxwa kwamanzi okuncinci kunye nokulibaziseka okuhle komlilo, okwenza libe lelona candelo le-PCB lisetyenziswa kakhulu. Le nto inomlinganiselo wokusebenza obiza kakhulu. Ngenxa yokuba isetyenzisiwe ixesha elide kushishino, inkqubo yayo yokucubungula ithathwa njengenkqubo eqhelekileyo kushishino lwebhodi yesekethe.

  Ngokubhekiselele ekuxhathiseni ubushushu, ukumelana kwayo nokuntywiliselwa kwi-welding ye-260 ° kugcinwa kwimizuzwana engaphezu kwe-120, kwaye olu hlobo lwezinto ezisisiseko zinokuhlangabezana neemfuno zenkqubo yokuwelda kwakhona, ukuwelda kwecala eliphindwe kabini, i-wave soldering kunye ne-adhesive curing.

  Ukushwankathela, ii-substrates ezahlukeneyo zineepropati ezahlukeneyo kunye neeparamitha kwaye zilungelelanise iimeko ezahlukeneyo zenkqubo. Ukongeza ekuhlangabezaneni nokusebenza kombane, abaqulunqi kufuneka bamkele iinkcukacha zoyilo ezahlukeneyo ngokwenkqubo yePCB yokusetyenzwa kunye nendibano ukuze baziqhelanise neemfuno ezahlukeneyo kwimveliso yePCB kunye nendibano. Kwangaxeshanye, abasebenzi benkqubo abajongene nendibano kufuneka baqonde ngokupheleleyo iimfuno zokusebenza kunye nendibano yezixhobo zePCB xa kuqulunqwa amaxwebhu enkqubo, ukuze kuqinisekiswe ukuveliswa kweemveliso ezifanelekileyo ezihlangabezana neemfuno zokusebenza koyilo kunye neemfuno zomgangatho.