Iingxaki ezibonakalayo zesohlwayo PCB Mveliso

Ngophuhliso lwamashishini e-elektroniki, ukuhlanganiswa kwezinto ze-elektroniki kuphezulu kwaye kuphezulu, kwaye ivolumu incinci kwaye incinci, kwaye uhlobo lweBGA lokupakisha lusetyenziswa kakhulu. Ke ngoko, isekethe ye-PCB iya kuba ncinane kwaye incinci, kwaye nenani leendlela ziya kuba ngakumbi nangakumbi. Ukunciphisa ububanzi bomgca kunye nokushiyeka komgca kukusebenzisa eyona ndawo imiselweyo, kwaye ukonyusa inani leendlela kukusebenzisa indawo. Eyona nto iphambili kwibhodi yesekethe kwixa elizayo yi-2-3mil okanye ngaphantsi.

Kukholelwa ngokubanzi ukuba ngalo lonke ixesha ibhodi yesekethe yemveliso inyuka okanye inyuka kwinqanaba, kufuneka ityalwe kube kanye, kwaye imali yotyalo-mali inkulu. Ngamanye amagama, iibhodi zesekethe ezikumgangatho ophezulu ziveliswa ngezixhobo ezikumgangatho ophezulu. Nangona kunjalo, ayililo lonke ishishini elinokufikelela kutyalo-mali olukhulu, kwaye kuthatha ixesha elininzi kunye nemali ukwenza uvavanyo lokuqokelela idatha yenkqubo kunye nokuveliswa kwetyala emva kotyalo mali. Umzekelo, kubonakala ngathi yeyona ndlela ilungileyo yokwenza uvavanyo kunye nokuvavanywa kwetyala ngokwemeko ekhoyo yeshishini, kwaye emva koko uthathe isigqibo sokuba uza kutyala imali ngokweyona meko ikhoyo kunye neemeko zentengiso. Eli phepha lichaza ngokweenkcukacha umda wobubanzi bemigca ebhityileyo enokuveliswa phantsi kwemeko yezixhobo eziqhelekileyo, kunye neemeko kunye neendlela zokuvelisa umgca omncinci.

Inkqubo yokuvelisa ngokubanzi inokwahlulwa ibe yindlela yokutshixa umngxuma kunye nendlela ye-graphic electroplating, zombini ezinoncedo kunye nezinto ezingalunganga. Isiphaluka esifunyenwe ngendlela ye-asidi yokudibanisa sifana kakhulu, esilungele ukulawulwa kwe-impedance kunye nokungcola okungaphantsi kwendalo, kodwa ukuba umngxuma uphukile, uya kutshitshiswa; Ukulawulwa kwemveliso ye-alkali kulula, kodwa umgca awulingani kwaye ungcoliseko lokusingqongileyo lukhulu.

Okokuqala, ifilimu eyomileyo lelona candelo libalulekileyo kwimveliso yomgca. Iifilimu ezahlukeneyo ezomileyo zinezigqibo ezahlukeneyo, kodwa ngokubanzi zinokubonisa ububanzi bomda kunye nokushiya umgca kwe-2mil / 2mil emva kokuvezwa. Isisombululo soomatshini abasesichengeni esiqhelekileyo sinokufikelela kwi-2mil. Ngokubanzi, umgca wokuhamba kunye nokushiya umgca ngaphakathi koluhlu akunakubangela iingxaki. Kwi-4mil / 4mil umgca wokuqhawula umgca we-line okanye ngaphezulu, ubudlelwane phakathi koxinzelelo kunye noxinzelelo lwamayeza alulwelo. Apha ngezantsi kwe-3mil / 3mil yomda wokuqhawulwa komgca, umgca wombhobho ngoyena ndoqo wokuchaphazela isisombululo. Ngokubanzi, kusetyenziswa umlomo omilise okwe fan, kwaye uphuhliso lunokwenziwa kuphela xa uxinzelelo lumalunga ne-3bar.

Nangona amandla okuveza enefuthe elikhulu emgceni, uninzi lweefilimu ezomileyo ezisetyenziswa kwimarike ngokubanzi zinoluhlu olubanzi lokuvezwa. Inokuhlulwa kwinqanaba 12-18 (inqanaba lama-25 irula yokuvezwa) okanye inqanaba 7-9 (inqanaba lama-21 irula yokuveza). Ngokubanzi, amandla okuvezwa okuphantsi alungele isisombululo. Nangona kunjalo, xa amandla ephantsi kakhulu, uthuli kunye nezinto ezahlukeneyo emoyeni zinempembelelo enkulu kuwo, zikhokelela kwisekethe evulekileyo (umhlwa we-asidi) okanye isekethe emfutshane (i-alkali corrosion) kwinkqubo yexesha elizayo Ke ngoko, eyona mveliso kufuneka ibe kudityaniswe nococeko lwegumbi elimnyama, ukuze ukhethe ubuncinci bomgca wobubanzi kunye nomgama womgama webhodi yesekethe enokuveliswa ngokwale meko.

Iziphumo zokuphuhlisa iimeko kwisisombululo zicace gca xa umgca umncinci. Xa umgca ungaphezulu kwe-4.0mil / 4.0mil, iimeko eziphuhlisayo (isantya, uxinzelelo lwamayeza alulwelo, uxinzelelo, njl.) Impembelelo ayicacanga; xa umgca uyi-2.0mil / 2.0 / mil, imilo noxinzelelo lombhobho zidlala indima ephambili nokuba umgca ungaphuhliswa ngokwesiqhelo. Ngeli xesha, isantya sophuhliso sinokuhla kakhulu. Kwangelo xesha, uxinzelelo lwamayeza alulwelo lunefuthe kwinkangeleko yomgca. Isizathu esinokubakho kukuba uxinzelelo lombhobho omile okwe fan lukhulu, kwaye impembelelo isenokufikelela ezantsi kwifilimu eyomileyo xa isithuba somgca sincinci kakhulu. ukuphuhlisa umgca olungileyo. Isalathiso senye ipleyiti inefuthe elibonakalayo kwisisombululo kunye nodonga olusecaleni lwefilimu eyomileyo.

Oomatshini abahlukeneyo bokubhengeza banezigqibo ezahlukeneyo. Okwangoku, umatshini omnye wokuvezwa upholile ngumoya, umthombo wokukhanya kwendawo, omnye upholile ngamanzi kunye nomthombo wokukhanya. Isisombululo sayo sesi-4mil. Nangona kunjalo, iimvavanyo zibonisa ukuba inokufikelela kwi-3.0mil / 3.0mil ngaphandle kohlengahlengiso olukhethekileyo okanye ukusebenza; inokufikelela kwi-0.2mil / 0.2 / mil; Xa amandla ancitshisiwe, anokwahlulwa nge-1.5mil / 1.5mil, kodwa umsebenzi kufuneka ulumke Ukongeza, akukho mahluko ucacileyo phakathi kwesisombululo somhlaba we-Mylar kunye nomphezulu weglasi kulingo.

Ukubola kwe-alkali, kuhlala kukho isiphumo se-mushroom emva kwe-electroplating, exhaphake ngokucacileyo kwaye ingabonakali. Umzekelo, ukuba umgca mkhulu kune-4.0mil / 4.0mil, isiphumo se-mushroom sincinci.

Xa umgca uyi-2.0mil / 2.0mil, ifuthe likhulu kakhulu. Ifilimu eyomileyo yenza imilo yamakhowa ngenxa yokugcwala kwelothe kunye ne-tin ngexesha le-electroplating, kunye nefilimu eyomileyo exineneyo ngaphakathi, nto leyo eyenza kube nzima kakhulu ukususa ifilimu. Izisombululo zezi: 1. Sebenzisa ukubetha kwentloko ukubetha iyunifomu yokutyabeka; 2. Sebenzisa ifilimu eyomileyo ejiyileyo, ifilimu eyomileyo iyonke zii-35-38 microns, kunye nefilimu eyomileyo eqinileyo yi-50-55 microns, ebiza kakhulu. Ifilimu eyomileyo iphantsi kwe-asidi etching 3. I-electroplating ephantsi yangoku. Kodwa ezi ndlela azigqibelelanga. Ngapha koko, kunzima ukuba nendlela epheleleyo.

Ngenxa yempembelelo yamakhowa, ukususwa kwemigca ebhityileyo kunzima kakhulu. Ngenxa yokuba umhlwa we-sodium hydroxide ukukhokela kunye ne-tin kuya kubonakala kakhulu kwi-2.0mil / 2.0mil, inokusombululwa ngokuqina kwe-lead kunye ne-tin kunye nokunciphisa uxinzelelo lwe-sodium hydroxide ngexesha le-electroplating.

Kwi-alkaline etching, ububanzi bomgca kunye nesantya zahlukile kwimilo eyahlukeneyo kunye nezantya ezahlukeneyo. Ukuba ibhodi yesekethe ayinazo iimfuno ezizodwa kubukhulu belayini evelisiweyo, ibhodi yesekethe enobunzima be-foil ye-0.25oz yobhedu iya kusetyenziswa ukuyenza, okanye inxenye yesiseko sobhedu se-0.5oz iya kufakwa, i-copper plated iya kuba ncinci, i-tin ekhokelayo iya kutyeba, njl. njl. Zonke zidlala indima ekwenzeni imigca ecolekileyo ene-alkaline etching, kwaye umlomo uya kuba uyifeni. Umlomo wombhoxo usetyenziswa ngokubanzi kuphela yi-4.0mil / 4.0mil.

Ngexesha le-acid Ke ngoko, kufuneka unonophelo ngexesha lokuvelisa. Isiphumo somgca wokurhawulwa kweasidi kubhetele kunokutsalwa kwealkali, akukho siphumo se-mushroom, ukhukuliseko lwecala lungaphantsi kwe-alkali, kunye nefuthe lombhobho omile fan ngokucacileyo ungcono kunombhobho we-conical. .

Kwinkqubo yemveliso, isantya kunye nobushushu befilimu yokutyabeka, ucoceko lomgangatho wepleyiti kunye nococeko lwefilimu ye-diazo inefuthe elikhulu kwinqanaba lokufumana isiqinisekiso, ebaluleke kakhulu kwiiparamitha zokwenza ifilimu ukutyabeka nefilimu umphezulu; Ukulungiswa kwe-alkali, ukucoceka kokuvezwa kubaluleke kakhulu.

Ke ngoko, kuthathelwa ingqalelo ukuba izixhobo eziqhelekileyo zinokuvelisa i-3.0mil / 3.0mil (ibhekisa kububanzi bomgca wefilimu kunye nokushiya izithuba) iibhodi ngaphandle kohlengahlengiso olukhethekileyo; Nangona kunjalo, inqanaba lesidanga liyachaphazeleka bubuchule kunye nenqanaba lokusebenza kwendalo esingqongileyo kunye nabasebenzi. Nokumelana kwealkali kufanelekile imveliso iibhodi wesekethe ngezantsi 3.0mil / 3.0mil. Ngaphandle kokuba ubhedu olungenasiseko lincinci ukuya kuthi ga kwinqanaba elithile, umphumo wombhobho omile okwe fan ubonakala ungcono kunowomlomo wombhoxo.