High Tg PCB
E hoʻololi ka substrate o High Tg circuit board mai ka "aniani mokuʻāina" a i ka "state rubber" ke piʻi aʻe ka mahana i kekahi wahi, a kapa ʻia kēia wela ka mahana aniani hoʻololi (Tg) o ka papa. I nā huaʻōlelo ʻē aʻe, ʻo Tg ka mahana nui (℃) kahi e paʻa ai ka substrate. ʻO ia ka mea, nā mea substrate PCB maʻamau i ka mahana wela ʻaʻole hana wale i ka palupalu, deformation, hoʻoheheʻe a me nā phenomena ʻē aʻe, akā ʻo ka hana pū me ka mechanical, nā ʻano uila o kahi hāʻule nui loa (manaʻo wau ʻaʻole makemake mākou e ʻike i kā lākou huahana e hōʻike kēia kūlana).
Nui e olelo ana, o ka papa o Tg Ua oi ma mua o 130 degere, kiʻekiʻe Tg Ua oi ma mua o 170 degere, a me ka meakino Tg mea oi aku mamua o 150 degere.
ʻO Tg≥170 ℃ PCB maʻamau, i kapa ʻia he kiʻekiʻe Tg PCB.
Ke piʻi ka Tg o ka substrate, e hoʻomaikaʻi ke kūpale o ka papa kaapuni, ke kūpale o ka wai, kūpaʻa kemika, kū paʻa paʻa a me nā ʻano ʻē aʻe. ʻO ke kiʻekiʻe o ka waiwai TG, ʻoi aku ka maikaʻi o ke kūpaʻa wela o ka pā. A pili pinepine ka TG kiʻekiʻe i ke kaʻina alakaʻi-ʻole,
ʻO ke kiʻekiʻe Tg pili i ke kūpaʻa wela kiʻekiʻe. Me ka ulu wikiwiki ʻana o ka ʻoihana uila a me nā huahana uila i hōʻike ʻia e ke kamepiula, ʻo ke kūpaʻa wela kiʻekiʻe o nā kumuwaiwai substrate PCB i lilo i mea hōʻoia i ka wā e ulu ai i kahi hana kiʻekiʻe a kiʻekiʻe multilayer. He aha hou aʻe, ke ʻano a me ka hoʻomohala ʻana o ka ʻenehana hoʻonoho kiʻekiʻe-kiʻekiʻe i kūlike ʻia e SMT a me CMT e hoʻolilo i ka PCB i kahi kaʻawale mai ke kākoʻo o ke kūpaʻa wela kiʻekiʻe o ka substrate i ka puka liʻiliʻi, kaapuni maikaʻi a me ka lahilahi.
No laila, ʻo ka ʻokoʻa ma waena o ka fr-4 ākea a me ka Tg fr-4 kiʻekiʻe ma ka mokuʻāina wela, keu hoʻi i ka hihia o ka wela ma hope o ka lawe ʻana o ka wai. A he nui nā ʻokoʻa i ka ikaika mechanical, kūpaʻa dimensional, adhesion, omo wai, palaho wela, hoʻonui hoʻomehana a me nā kūlana ʻē aʻe o nā mea. ʻO nā huahana me Tg kiʻekiʻe he mea ʻoi aku ka maikaʻi 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 ka hana o ka papa kaapuni kiʻekiʻe Tg i kēlā me kēia makahiki.