PCBA uye SMT kugadzirisa kunowanzo kuve nemaitiro maviri, imwe inotungamira-isina maitiro uye imwe inotungamira maitiro. Munhu wose anoziva kuti mutobvu unokuvadza vanhu. Nokudaro, iyo inotungamira-isina nzira inosangana nezvinodiwa zvekuchengetedzwa kwezvakatipoteredza, iyo inowanzoitika uye sarudzo isingadzivisiki munhoroondo. . Hatifungi kuti PCBA inogadzira zvidyarwa pazasi pechiyero (pazasi pe20 SMT mitsetse) ine kugona kubvuma zvese zvinotungamira-isina uye zvinotungamira-isina SMT magadzirirwo mirairo, nekuti musiyano pakati pezvinhu, zvishandiso, uye maitiro anowedzera zvakanyanya mutengo uye kuoma. of management. Handizive kuti zviri nyore sei kuita lead-yemahara process yakananga.
Pazasi, mutsauko uripo pakati pekutungamirira uye nzira isina-lead inopfupikiswa muchidimbu sezvizvi. Pane zvimwe zvisina kukwana, uye ndinovimba munogona kundiruramisa.
1. Kuumbwa kwealloy kwakasiyana: iyo inowanzotungamira tin-lead kuumbwa ndeye 63/37, nepo lead-isina alloy kuumbwa kweSAC 305, ndiko kuti, Sn: 96.5%, Ag: 3%, Cu: 0.5%. Iyo inotungamira-isina maitiro haigone kuvimbisa zvachose kuti haina zvachose mutobvu, ine chete yakaderera zvakanyanya yemukati, senge lead iri pasi pe500 PPM.
2. Kusiyana kwakanyunguduka: nzvimbo yakanyunguduka ye-lead-tin ndeye 180 ° ~ 185 °, uye kutonhora kwekushanda kunenge 240 ° ~ 250 °. Nzvimbo yakanyunguduka yerata isina mutobvu i210°~235°, uye tembiricha yekushanda i245°~280°. Maererano nezvakaitika, kune yega yega 8% -10% kuwedzera kwetin content, iyo inonyunguduka inowedzera neanenge 10 madhigirii, uye tembiricha yekushanda inowedzera ne10-20 madhigirii.
3. Mutengo wakasiyana: mutengo werata unodhura kupfuura wemutobvu. Kana iyo solder yakakosha yakaenzana inotsiviwa netini, mutengo we solder uchakwira zvakanyanya. Nokudaro, mari yehutungamiri-isina nzira yakakwirira zvikuru kupfuura iyo yekutungamirira nzira. Nhamba dzinoratidza kuti tin bar ye wave soldering uye tin wire ye manual soldering, iyo inotungamira-isina nzira yakakwira 2.7 nguva yakakwira kupfuura iyo inotungamira maitiro, uye solder paste ye reflow soldering Mutengo unowedzerwa neanenge 1.5 nguva.
4. Nzira yacho yakasiyana-siyana: iyo inotungamirira nzira uye nzira isina kutungamirira inogona kuonekwa kubva kune zita. Asi zvakanangana nemaitiro, solder, zvikamu, uye zvishandiso zvinoshandiswa, senge wave soldering furnaces, solder paste maprinta, uye simbi dzekutengesa dzemanyorero solder, zvakasiyana. Ichi zvakare chikonzero chikuru nei zvichinetsa kubata ese ari maviri anotungamira uye asina-yemahara maitiro mune diki-chikero PCBA kugadzirisa chirimwa.
Mimwe misiyano senge process hwindo, solderability, uye kuchengetedzwa kwezvakatipoteredza zvinodiwa zvakasiyana. Iwindo rekuita rekutungamirira rakakura uye solderability ichava nani. Nekudaro, nekuti iyo inotungamira-isina maitiro ane hushamwari kwezvakatipoteredza, uye tekinoroji inoramba ichivandudza, iyo inotungamira-isina maitiro tekinoroji yakawedzera kuvimbika uye yakakura.