1. An tattara PBGA a cikinInjin SMT, kuma ba a aiwatar da tsarin dehumidification kafin waldawa, wanda ke haifar da lalacewar PBGA a lokacin walda.
Siffofin marufi na SMD: marufi mara iska, gami da fakitin tukunyar tukunyar filastik da resin epoxy, marufin guduro na silicone (wanda aka fallasa ga iska ta yanayi, kayan yumbu mai yuwuwa).Duk fakitin filastik suna ɗaukar danshi kuma ba a rufe su gaba ɗaya.
Lokacin da MSD lokacin da aka fallasa zuwa haɓakareflow tandayanayin zafin jiki, saboda kutsawar damshin ciki na MSD don ƙafewa don samar da isasshen matsi, sanya akwatin filastik daga guntu ko fil akan layi da kai don haɗa lalacewar kwakwalwan kwamfuta da fashewar ciki, a cikin matsanancin yanayi, fashe yana ƙara zuwa saman MSD. , har ma yana haifar da balloon MSD da fashe, wanda aka sani da al'amarin "popcorn".
Bayan bayyanar da iska na dogon lokaci, danshin da ke cikin iska yana yaduwa cikin kayan marufi masu lalacewa.
A farkon reflow soldering, lokacin da zafin jiki ne mafi girma fiye da 100 ℃, da surface zafi na aka gyara yana ƙaruwa a hankali, da kuma ruwa a hankali tattara zuwa bonding part.
A lokacin da surface Dutsen waldi tsari, da SMD ne fallasa zuwa yanayin zafi fiye da 200 ℃.A lokacin babban yawan zafin jiki, haɗuwa da abubuwa kamar saurin faɗaɗa danshi a cikin abubuwan da aka gyara, rashin daidaituwar kayan, da lalacewar mu'amalar kayan na iya haifar da fashe fakiti ko lalatawa a maɓalli na ciki.
2. Lokacin walda gubar-free aka gyara kamar PBGA, sabon abu na MSD "popcorn" a cikin samarwa zai zama mafi m da tsanani saboda karuwar walda zafin jiki, kuma ko da kai ga samar ba zai iya zama al'ada.
Lokacin aikawa: Agusta-12-2021