Koi no ke alakai-free reflow soldering ma PCB

Ke alakai-noa reflow soldering kaʻina i nui kiʻekiʻe koi ma ka PCB ma mua o ke alakai-ma muli kaʻina.ʻOi aku ka maikaʻi o ka pale wela o ka PCB, ʻoi aku ka kiʻekiʻe o ke aniani hoʻololi Tg, ʻoi aku ka liʻiliʻi o ka hoʻonui ʻana o ka wela, a ʻoi aku ka haʻahaʻa.

Lead-free reflow soldering koi no PCB.

I ka reflow soldering, Tg he waiwai kū hoʻokahi o nā polymers, e hoʻoholo ana i ka wela koʻikoʻi o nā waiwai waiwai.I ka wā o ke kaʻina hana soldering SMT, ʻoi aku ka kiʻekiʻe o ka mahana kūʻai aku ma mua o ka Tg o ka PCB substrate, a ʻo ka 34 ° C ke kiʻekiʻe kiʻekiʻe o ke kumu kūʻai ʻana me ke alakaʻi, kahi e maʻalahi ai ka deformation thermal o ka PCB a me ka pōʻino. i nā ʻāpana i ka wā hoʻoluʻu.Pono e koho pono ʻia ke kumu PCB me ka Tg kiʻekiʻe.

I ka wā wili, inā piʻi ka mahana, ʻaʻole i kūlike ka Z-axis o ka multilayer structure PCB i ka CTE ma waena o nā mea laminated, aniani fiber, a me Cu ma ke kuhikuhi XY, e hoʻohua nui i ke koʻikoʻi ma ka Cu, a ma ʻO nā hihia koʻikoʻi, e wāwahi ʻia ka uhi ʻana o ka lua metala a hoʻopilikia i nā hemahema.No ka mea, hilinaʻi ia i nā ʻano like ʻole, e like me ka helu papa PCB, mānoanoa, laminate material, soldering curve, a me Cu distribution, via geometry, etc.

I kā mākou hana maoli, ua lawe mākou i kekahi mau hana e lanakila ai i ka haki o ka puka metala o ka papa multilayer: no ka laʻana, ua wehe ʻia ka resin / aniani fiber i loko o ka lua ma mua o ka electroplating i ke kaʻina hana etching recess.E hoʻoikaika i ka ikaika hoʻopaʻa ma waena o ka paia puka metala a me ka papa multi-layer.ʻO ka hohonu o ka etch he 13-20µm.

ʻO ka palena wela o ka FR-4 substrate PCB he 240°C.No nā huahana maʻalahi, hiki i ka wela kiʻekiʻe o 235 ~ 240 ° C ke hoʻokō i nā koi, akā no nā huahana paʻakikī, pono paha ka 260 ° C e soldered.No laila, pono e hoʻohana nā papa mānoanoa a me nā huahana paʻakikī e hoʻohana i ka FR-5 pale wela kiʻekiʻe.No ka mea he kiʻekiʻe ke kumu kūʻai o FR-5, no nā huahana maʻamau, hiki ke hoʻohana ʻia ka CEMn base composite e pani i nā substrates FR-4.ʻO CEMn kahi laminate i hoʻopaʻa ʻia me ke keleawe paʻa paʻa nona ka ʻili a me ke kumu o nā mea like ʻole.ʻO CEMn no ka pōkole e hōʻike ana i nā hiʻohiʻona like ʻole.