Apo kutonhora kwepamusoro Tg yakadhindwa bhodhi inokwira kune imwe nzvimbo, iyo substrate ichachinja kubva ku "girazi mamiriro" kusvika ku "rubber state", uye kutonhora panguva ino kunonzi girazi rekushandura tembiricha (Tg) yebhodhi.
Mune mamwe mazwi, Tg ndiyo tembiricha yepamusoro (° C) apo iyo substrate inochengetedza kuomarara. Kureva kuti, zvakajairwa PCB substrate zvinhu hazvingogadziri kupfava, deformation, kunyunguduka uye zvimwe zviitiko pakupisa kwakanyanya, asi zvakare zvinoratidza kudzikira kwakanyanya mumakina uye magetsi maitiro (ndinofunga haudi kuona izvi mune zvigadzirwa zvako) .
Kazhinji, Tg mahwendefa ari pamusoro pe130 madhigirii, yakakwira Tg kazhinji yakakura kupfuura 170 madhigirii, uye yepakati Tg inenge 150 madhigirii. Kazhinji PCB yakadhindwa bhodhi ine Tg≥:170℃ inonzi yakakwira Tg yakadhindwa bhodhi. Iyo Tg ye substrate inowedzera, uye kupisa kwekudzivirira, kunyorova kwemvura, kupikisa kwemakemikari, kugadzikana uye mamwe maitiro ebhodhi rakadhindwa zvichavandudzwa nekuvandudzwa. Iyo yakakwira iyo TG kukosha, zviri nani kupikisa tembiricha yebhodhi, kunyanya mukutungamira-isina maitiro, uko yakakwirira Tg maapplication akajairika. High Tg inoreva kupisa kwakanyanya.
Nekukurumidza kukurumidza kweindasitiri yemagetsi, kunyanya zvigadzirwa zvemagetsi zvinomiririrwa nemakomputa, kusimudzira kwekushanda kwepamusoro uye yakakwirira multilayers kunoda kupisa kwakanyanya kwePCB substrate zvinhu sevimbiso yakakosha.
Kubuda uye kukura kwepamusoro-density mounting tekinoroji inomiririrwa neSMT.CMT yakaita kuti maPCB awedzere kuparadzaniswa kubva pakutsigirwa kwekupisa kwekupisa kwe substrates maererano nekuvhura kudiki, kutenderera kwakanaka uye kutetepa. Naizvozvo, musiyano pakati peyakajairwa FR-4 uye yakakwira Tg FR-4: isimba remagetsi, kugadzikana kwedimensional, kunamatira, kunyura kwemvura, uye kuparara kwekupisa kwezvinhu pasi penzvimbo inopisa, kunyanya kana inopisa mushure mekunyorova kwemwando. Kune misiyano mumamiriro akasiyana akadai sekuwedzera kwekupisa, yakakwira Tg zvigadzirwa zviri pachena zviri nani pane zvakajairwa PCB substrate zvinhu. Mumakore achangopfuura, nhamba yevatengi inoda yakakwirira Tg yakadhindwa mabhodhi yakawedzera gore negore.