1. Nauyin allon da kansa zai haifar da nakasar allo
Gabaɗayareflow tandaza su yi amfani da sarkar don fitar da allo gaba, wato, bangarorin biyu na allon a matsayin abin da ya dace don tallafawa dukkan allon.
Idan akwai abubuwa masu nauyi da yawa a jikin allo, ko girman allo ya yi yawa, zai nuna damuwa ta tsakiya saboda nauyinsa, wanda hakan zai sa allon ya lanƙwasa.
2. Zurfin V-Cut da haɗin haɗin haɗin gwiwa zai shafi lalacewar allon.
Ainihin, V-Cut shine mai laifi na lalata tsarin hukumar, saboda V-Cut shine yanke tsagi a kan babban takarda na allon asali, don haka yankin V-Cut yana da wuyar lalacewa.
Tasirin kayan lamination, tsari da zane-zane akan nakasar jirgi.
PCB allon an yi shi da core allo da Semi-warke takardar da waje tagulla foil da aka matse tare, inda core allon da tagulla foil suna nakasu da zafi lokacin da aka danna tare, da kuma adadin nakasawa ya dogara da coefficient na thermal fadada (CTE) na biyu kayan.
Matsakaicin haɓakar haɓakar thermal (CTE) na bangon jan ƙarfe yana kusan 17X10-6;yayin da Z-directional CTE na talakawa FR-4 substrate ne (50 ~ 70) X10-6 karkashin Tg batu;(250 ~ 350) X10-6 a sama da maki TG, kuma X-directional CTE gabaɗaya yana kama da na tagulla saboda kasancewar gilashin gilashi.
Nakasar da aka samu yayin sarrafa hukumar PCB.
PCB hukumar sarrafa tsari nakasawa haddasawa ne sosai hadaddun za a iya raba thermal danniya da inji danniya lalacewa ta hanyar iri biyu danniya.
Daga cikin su, an fi haifar da damuwa ta thermal a cikin aiwatar da dannawa tare, damuwa na inji yana haifar da mafi yawa a cikin allon allo, sarrafawa, tsarin yin burodi.Mai zuwa shine taƙaitaccen tattaunawa na jerin tsari.
1. Laminate mai shigowa abu.
Laminate suna da gefe biyu, tsari mai ma'ana, babu zane-zane, foil na jan karfe da gilashin gilashin CTE ba shi da bambanci sosai, don haka a cikin latsa tare kusan babu nakasar da ta haifar da CTE daban-daban.
Duk da haka, girman girman laminate da kuma bambancin zafin jiki tsakanin wurare daban-daban na farantin zafi na iya haifar da ƙananan bambance-bambance a cikin sauri da digiri na resin curing a wurare daban-daban na tsarin lamination, da kuma babban bambance-bambance a cikin danko mai ƙarfi. a farashin dumama daban-daban, don haka kuma za a sami damuwa na gida saboda bambance-bambance a cikin hanyar warkewa.
Gabaɗaya, wannan damuwa za a kiyaye cikin daidaito bayan lamination, amma a hankali za a saki a nan gaba aiki don samar da nakasawa.
2. Lamincewa.
Tsarin lamination na PCB shine babban tsari don samar da damuwa na thermal, kama da laminate lamination, kuma zai haifar da damuwa na gida wanda aka kawo ta hanyar bambance-bambance a cikin tsarin warkarwa, kwamitin PCB saboda kauri, rarraba hoto, ƙarin takaddar warkewa, da sauransu. Matsalolin zafinsa kuma zai fi wahalar kawarwa fiye da laminate na jan karfe.
Ana fitar da matsalolin da ke cikin hukumar PCB a cikin matakai masu zuwa kamar hakowa, siffatawa ko gasa, wanda ke haifar da nakasar allon.
3. Hanyoyin yin burodi irin su solder tsayayya da hali.
Kamar yadda solder tsayayya tawada curing ba za a iya stacked a saman juna, don haka da PCB hukumar za a sanya a tsaye a cikin tara yin burodi hukumar curing, solder tsayayya zafin jiki na game da 150 ℃, kawai sama da Tg batu na low Tg abu, Tg batu. sama da guduro don babban matsayi na roba, jirgi yana da sauƙi don lalacewa a ƙarƙashin tasirin nauyin kai ko tanda mai karfi.
4. Matakan solder iska mai zafi.
Talakawa jirgin zafi iska solder leveling tanderun zafin jiki na 225 ℃ ~ 265 ℃, lokaci ga 3S-6S.zafin iska mai zafi na 280 ℃ ~ 300 ℃.
Solder daidaita allo daga zafin daki zuwa cikin tanderun, fita daga cikin tanderun cikin minti biyu sannan zafin dakin bayan sarrafa ruwa.Dukkanin tsarin daidaita matakan siyar da iska mai zafi don tsarin zafi da sanyi kwatsam.
Saboda kayan aikin jirgi ya bambanta, kuma tsarin ba daidai ba ne, a cikin tsari mai zafi da sanyi yana daure da damuwa na thermal, yana haifar da ƙananan ƙwayar cuta da kuma gaba ɗaya nakasar warpage.
5. Adana.
PCB jirgin a cikin Semi-ƙare mataki na ajiya ne kullum a tsaye saka a cikin shiryayye, shiryayye tashin hankali daidaitawa bai dace ba, ko ajiya tsari stacking sa jirgin zai sa hukumar inji nakasawa.Musamman ga 2.0mm da ke ƙasa da tasirin allon bakin ciki ya fi tsanani.
Baya ga abubuwan da ke sama, akwai abubuwa da yawa waɗanda ke shafar nakasar allon PCB.
Lokacin aikawa: Satumba-01-2022