Ke piʻi ka mahana o kahi papa paʻi Tg kiʻekiʻe i kahi ʻāpana, e hoʻololi ka substrate mai ka "mokuʻāina aniani" a i "ke aupuni Ruber", a kapa ʻia ka mahana i kēia manawa ʻo ke aniani hoʻololi wela (Tg) o ka papa.

ʻO ia hoʻi, ʻo Tg ka wela kiʻekiʻe loa (°C) kahi e mālama ai ka substrate i ka paʻakikī. ʻO ia hoʻi, ʻaʻole wale nā ​​​​mea hoʻoheheʻe PCB maʻamau e hoʻoheheʻe, deformation, hoʻoheheʻe a me nā mea ʻē aʻe i nā mahana kiʻekiʻe, akā hōʻike pū kekahi i ka emi ʻana o nā ʻano mechanical a me nā uila (manaʻo wau ʻaʻole makemake ʻoe e ʻike i kēia i kāu huahana) .

ʻO ka maʻamau, ʻoi aku ka nui o nā papa Tg ma luna o 130 degere, ʻoi aku ka nui o Tg kiʻekiʻe ma mua o 170 degere, a ʻo ka Tg waena ma kahi o 150 degere. ʻO ka maʻamau ka papa paʻi PCB me Tg≥:170 ℃ kapa ʻia ka papa paʻi Tg kiʻekiʻe. Hoʻonui ʻia ka Tg o ka substrate, a e hoʻomaikaʻi a hoʻomaikaʻi ʻia ka pale ʻana o ka wela, ka pale ʻana i ka wai, ke kūpaʻa kemika, ke kūpaʻa a me nā ʻano ʻē aʻe o ka papa i paʻi ʻia. ʻOi aku ka kiʻekiʻe o ka waiwai TG, ʻoi aku ka maikaʻi o ka pale wela o ka papa, ʻoi aku ka maikaʻi ma ke kaʻina alakaʻi ʻole, kahi e maʻa mau ai nā noi Tg kiʻekiʻe. ʻO ka Tg kiʻekiʻe e pili ana i ka pale wela kiʻekiʻe.

Me ka hoʻomohala wikiwiki ʻana o ka ʻoihana uila, ʻoi aku ka nui o nā huahana uila i hōʻike ʻia e nā kamepiula, ʻo ka hoʻomohala ʻana i nā hana kiʻekiʻe a me nā multilayers kiʻekiʻe e koi ai i ka pale wela kiʻekiʻe o nā mea PCB substrate i mea hōʻoia nui.

ʻO ka puka ʻana a me ka hoʻomohala ʻana o ka ʻenehana hoʻokiʻekiʻe kiʻekiʻe i hōʻike ʻia e SMT.CMT ua hana ʻo ia i nā PCB i ʻoi aku ka hiki ke hoʻokaʻawale ʻia mai ke kākoʻo o ke kūpaʻa wela kiʻekiʻe o nā substrates ma ke ʻano o ka puka liʻiliʻi, ka pōʻai maikaʻi a me ka thinning. No laila, ʻo ka ʻokoʻa ma waena o ka FR-4 maʻamau a me ka Tg FR-4 kiʻekiʻe: ʻo ia ka ikaika mechanical, dimensional stability, adhesiveness, wai absorption, a me ka thermal decomposition o ka mea ma lalo o ka mokuʻāina wela, ʻoi aku hoʻi i ka wā i hoʻomehana ʻia ma hope o ka lawe ʻana i ka wai. Aia nā ʻokoʻa i nā kūlana like ʻole e like me ka hoʻonui ʻana i ka wela, ʻoi aku ka maikaʻi o nā huahana Tg kiʻekiʻe ma mua o nā mea substrate PCB maʻamau. I nā makahiki i hala iho nei, ua hoʻonui ʻia ka nui o nā mea kūʻai aku e koi ana i nā papa paʻi kiʻekiʻe Tg i kēlā me kēia makahiki.