PCBA,Kugadziriswa kweSMT kunowanzo kuve nemhando mbiri dzemaitiro, imwe ndeye lead-isina maitiro, imwe yacho inotungamira maitiro, isu tese tinoziva kuti lead inokuvadza kuvanhu, saka lead-isina maitiro inosangana nezvinodiwa zvekuchengetedzwa kwezvakatipoteredza, ndiwo maitiro e nguva, chisarudzo chisingadzivisiki chenhau.
Pazasi, mutsauko uripo pakati penzira yekutungamirira uye nzira isina kutungamirira inopfupikiswa muchidimbu sezvinotevera.Kana tekinoroji yepasi rose SMT chip processing analysis isina kukwana, tinovimba unogona kugadzirisa zvimwe.
1. Kuumbwa kwealloy kwakasiyana: 63 / 37 yetin uye lead zvakajairika mukutungamirira, nepo sac 305 iri mune lead-isina alloy, kureva, SN: 96.5%, Ag: 3%, Cu: 0.5% .Lead yemahara process haigone kuvimbisa zvachose kuti hapana lead zvachose, inongove ine yakaderera yemukati ye lead, senge lead iri pasi pe500 ppm.
2. Mapoinzi ekunyungudika akasiyana: lead tin melting point i180 ° kusvika 185 ° uye tembiricha yekushanda inenge 240 ° kusvika 250 °.Nzvimbo yakanyungudika yerata isina mutobvu i210 ° kusvika 235 ° uye tembiricha yekushanda i245 ° kusvika 280 ° zvichiteerana.Maererano nezvakaitika, imwe neimwe ye8% - 10% inowedzera mune zvinyorwa zvetini, iyo inonyunguduka inowedzera inenge 10 degrees, uye kutonhora kwekushanda kunowedzera ne10-20 degrees.
3. Mutengo wacho wakasiyana: tini inodhura kupfuura mutobvu, uye apo iyo yakaenzana yakakosha solder inoshandura inotungamirira kune tini, mari ye solder inowedzera zvakanyanya.Naizvozvo, mutengo wemutobvu-isina maitiro wakakwira zvakanyanya kupfuura iwo wemutobvu maitiro.Nhamba dzinoratidza kuti mari yekutungamirira-isina nzira yakakwira 2.7 nguva yakakwira kupfuura iyo yekusatungamira-isina process, uye mutengo wesolder paste ye reflow soldering inenge 1.5 yakakwira kupfuura iyo yekusatungamira-isina process.
4. Nzira yacho yakasiyana-siyana: kune nzira dzinotungamirira uye dzisina kutungamirira, dzinogona kuonekwa kubva kune zita.Asi zvakananga kuti muitiro, ndiko kushandisa solder, zvinoriumba uye midziyo, akadai wave soldering choto, solder namatidza kudhinda muchina, soldering simbi nokuda manual welding, etc. Ichi ndichowo chikonzero chikuru nei zvakaoma kugadzirisa zvose zvinotungamirira- yemahara uye inotungamira maitiro mune diki-mwero PCBA yekugadzirisa chirimwa.
Misiyano mune zvimwe zvinhu, senge process hwindo, weldability uye kuchengetedzwa kwezvakatipoteredza zvinodiwa zvakasiyana.Iwindo rekuita rekutungamirira rakakura uye solderability iri nani.Nekudaro, nekuti nhanho-yemahara nzira inowirirana nezvinodiwa zvekuchengetedza kwezvakatipoteredza, uye nekuenderera mberi kwehunyanzvi hwetekinoroji chero nguva, tekinoroji-yemahara process tekinoroji yakawedzera kuvimbika uye yakakura.
Nguva yekutumira: Jul-29-2020
