Tsarin sake kwarara mara gubar yana da buƙatu mafi girma akan PCB fiye da tsarin tushen gubar.Juriya mai zafi na PCB ya fi kyau, canjin gilashin zafin jiki na Tg ya fi girma, haɓakar haɓakar thermal yana da ƙasa, kuma farashin yana da ƙasa.
Bukatun siyarwar da ba ta da gubar don PCB.
A reflow soldering, Tg ne na musamman dukiya na polymers, wanda kayyade m zafin jiki na abu kaddarorin.A lokacin SMT soldering tsari, da soldering zafin jiki ne da yawa mafi girma fiye da Tg na PCB substrate, da gubar-free soldering zafin jiki ne 34 ° C fiye da cewa da gubar, wanda ya sa shi sauki ga thermal nakasawa na PCB da lalacewa. zuwa sassa a lokacin sanyaya.Ya kamata a zaɓi kayan PCB na tushe tare da Tg mafi girma da kyau.
A lokacin waldi, idan yawan zafin jiki ya karu, Z-axis na tsarin multilayer PCB bai dace da CTE tsakanin kayan da aka lakafta ba, fiber gilashi, da Cu a cikin hanyar XY, wanda zai haifar da damuwa mai yawa akan Cu, kuma a cikin lokuta masu tsanani, zai haifar da plating na rami mai ƙarfe ya karye kuma ya haifar da lahani na walda.Domin ya dogara da masu canji da yawa, kamar lambar layin PCB, kauri, kayan laminate, shingen shinge, da rarraba Cu, ta hanyar lissafi, da sauransu.
A cikin ainihin aikinmu, mun ɗauki wasu matakai don shawo kan karyewar rami mai ƙarfe na allon multilayer: alal misali, zaren resin/gilasi ana cire shi a cikin ramin kafin yin amfani da wutar lantarki a cikin tsarin etching.Don ƙarfafa ƙarfin haɗin kai tsakanin bangon ramin da aka yi da ƙarfe da kuma allon multilayer.Zurfin etch shine 13 ~ 20µm.
Matsakaicin zafin jiki na FR-4 substrate PCB shine 240 ° C.Don samfurori masu sauƙi, yawan zafin jiki na 235 ~ 240 ° C na iya biyan bukatun, amma don samfurori masu rikitarwa, yana iya buƙatar 260 ° C don sayarwa.Saboda haka, kauri faranti da hadaddun kayayyakin bukatar yin amfani da high zafin jiki resistant FR-5.Saboda farashin FR-5 yana da girma, don samfuran yau da kullun, ana iya amfani da madaidaicin tushe CEMn don maye gurbin FR-4 substrates.CEMn wani tsattsauran ra'ayi ne mai kauri mai kauri mai kauri wanda samansa da ainihinsa an yi shi da abubuwa daban-daban.CEMn a takaice yana wakiltar samfura daban-daban.
Lokacin aikawa: Yuli-22-2023