ʻO nā lapaʻau ākea ākea o PCB e hoʻokomo i ka paila kī, OSP, ka hoʻokomo gula, a me nā mea ʻē aʻe. ʻO ka “surface” ma ʻaneʻi e pili ana i nā wahi hoʻopili ma ka PCB e hāʻawi ana i nā pilina uila ma waena o nā mea uila a i ʻole nā ​​ʻōnaehana ʻē aʻe a me ke kaapuni o ka PCB, e like me nā pads. A i ʻole e hoʻopili i ka wahi pili. He maikaʻi loa ka solderability o ke keleawe keleawe ponoʻī, akā maʻalahi ka oxidize i ka wā e ʻike ʻia ai i ka lewa, a maʻalahi hoʻi e hoʻohaumia ʻia. ʻO kēia ke kumu e pono ai e mālama ʻia ka PCB.

1. Pīpī pā (HASL)

Ma kahi e lanakila ai nā mea hoʻoheheʻe ʻia, ʻo ke kūʻai aku ʻana i ka nalu ʻo ia ke ala kūʻai maikaʻi loa. ʻO ka hoʻohana ʻana i ka ʻenehana hoʻoheheʻe wela wela (HASL, Hot-air solder leveling) ʻenehana lapaʻau ʻili ua lawa ia e hoʻokō i nā koi kaʻina o ke kūʻai ʻana i ka nalu. ʻOiaʻiʻo, no nā manawa e koi ai i ka ikaika junction kiʻekiʻe (ʻoi aku ka pilina pili), hoʻohana pinepine ʻia ka electroplating o nickel/gold. . ʻO HASL ka ʻenehana lapaʻau nui i hoʻohana ʻia ma ka honua holoʻokoʻa, akā aia ʻekolu mau mea hoʻokele nui e hoʻokele i ka ʻoihana uila e noʻonoʻo i nā ʻenehana ʻē aʻe no HASL: ke kumukūʻai, nā koi kaʻina hana hou a me nā koi alakaʻi ʻole.

Mai ka manaʻo kumu kūʻai, nui nā mea uila e like me ke kamaʻilio kelepona a me nā kamepiula pilikino e lilo i mea kūʻai kaulana. Ma ke kūʻai wale ʻana ma ke kumukūʻai a i ʻole nā ​​​​kumukūʻai haʻahaʻa e hiki ai iā mākou ke lanakila ʻole i loko o ke ʻano hoʻokūkū ikaika. Ma hope o ka hoʻomohala ʻana o ka ʻenehana hui i SMT, pono nā pads PCB i ka paʻi ʻana i ka pale a me ka reflow soldering kaʻina i ka wā o ke kaʻina hana. I ka hihia o SMA, ua hoʻohana mau ka PCB surface treatment process i ka ʻenehana HASL ma mua, akā i ka hoʻomau ʻana o nā mea SMT i ka emi ʻana, ua liʻiliʻi nā pads a me nā stencil, a ua hōʻike ʻia nā drawbacks o ka ʻenehana HASL. ʻAʻole pālahalaha nā pads i hana ʻia e ka ʻenehana HASL, a ʻaʻole hiki i ka coplanarity ke hoʻokō i nā koi kaʻina o nā pad fine-pitch. Hoʻopili pinepine nā manaʻo pili i ka hopena o ke alakaʻi i ke kaiapuni.

2. Layer Hoʻopaʻa Paʻa Ola (OSP)

Organic solderability preservative (OSP, Organic solderability preservative) he mea ia e hoʻohana ʻia e pale i ka oxidation o ke keleawe ma mua o ke kūʻai ʻana, ʻo ia hoʻi, e pale i ka solderability o nā pā PCB mai ka pōʻino.

Ma hope o ka mālama ʻia ʻana o ka PCB me ka OSP, ua hoʻokumu ʻia kahi pūhui organik lahilahi ma luna o ka ʻili o ke keleawe e pale aku i ke keleawe mai ka oxidation. ʻO ka mānoanoa o Benzotriazoles OSP he 100 A°, ʻoiai ʻoi aku ka mānoanoa o Imidazoles OSP, maʻamau 400 A°. ʻO ke kiʻiʻoniʻoni OSP he mea akaka, ʻaʻole maʻalahi ke ʻike i kona ola ʻana me ka maka ʻōlohelohe, a paʻakikī ke ʻike. I ka wā o ke kaʻina hana (reflow soldering), hiki ke hoʻoheheʻe ʻia ka OSP i loko o ka solder paste a i ʻole acidic Flux, a i ka manawa like e hōʻike ʻia ka ʻili keleawe ikaika, a ma hope loa ua hoʻokumu ʻia nā pūhui intermetallic Sn/Cu ma waena o nā ʻāpana a me nā pads. No laila, maikaʻi loa nā hiʻohiʻona o OSP ke hoʻohana ʻia e mālama i ka ʻili kuʻi. ʻAʻole loaʻa iā OSP ka pilikia o ka pollution kepau, no laila ua pili kaiapuni.

Nā palena o OSP:

①. No ka mea, ʻaʻole ʻike ʻia ka OSP a me ka waihoʻoluʻu ʻole, paʻakikī ke nānā ʻana, a paʻakikī ke ʻike inā ua uhi ʻia ka PCB me OSP.

② Hoʻopili ʻia ʻo OSP ponoʻī, ʻaʻole ia e alakaʻi i ka uila. He lahilahi ka OSP o Benzotriazoles, ʻaʻole hiki ke hoʻopili i ka hoʻāʻo uila, akā no ka OSP o Imidazoles, ʻano mānoanoa ke kiʻi pale i hana ʻia, e pili ana i ka hoʻāʻo uila. ʻAʻole hiki ke hoʻohana ʻia ʻo OSP no ka mālama ʻana i nā ʻili pili uila, e like me nā papa keyboard no nā kī.

③ I ka wā o ke kaʻina hana hoʻoheheʻe o OSP, pono ka Flux ikaika, inā ʻaʻole hiki ke hoʻopau ʻia ke kiʻi pale, kahi e alakaʻi ai i nā hemahema wili.

④ I ka wā o ka mālama ʻana, ʻaʻole pono e ʻike ʻia ka ʻili o ka OSP i nā mea waikawa, a ʻaʻole kiʻekiʻe ka mahana, i ʻole e hoʻololi ka OSP.

3. gula kaiapuni (ENIG)

ʻO ka hana palekana o ENIG:

Hoʻopili ʻia ʻo Ni/Au ma ka ʻili keleawe ma ke ʻano kemika. ʻO ka mānoanoa deposition o ka papa o loko o Ni ka mea maʻamau 120 a 240 μin (ma kahi o 3 a 6 μm), a ʻo ka mānoanoa deposition o ka papa waho o Au he mea lahilahi, maʻamau 2 a 4 μin (0.05 a 0.1 μm). Hana ʻo Ni i kahi papa pale ma waena o ka solder a me ke keleawe. I ka wā kūʻai, e hehee koke ka Au ma waho i ka solder, a ʻo ka solder a me Ni e hana i kahi hui Ni / Sn intermetallic. ʻO ka uhi gula ma waho ka mea e pale ai i ka Ni oxidation a i ʻole passivation i ka wā o ka waiho ʻana, no laila e lawa pono ka ʻāpana gula a ʻaʻole lahilahi ka mānoanoa.

Immersion gula: Ma kēia kaʻina hana, ʻo ke kumu e waiho i kahi ʻāpana pale gula lahilahi a mau. ʻAʻole mānoanoa ka mānoanoa o ke gula nui, inā ʻaʻole e lilo nā ʻāpana solder i mea palupalu, e hoʻopilikia nui i ka hilinaʻi o ka welding. E like me ka nickel plating, he kiʻekiʻe ka mahana hana o ke gula immersion a lōʻihi ka manawa. I ka wā o ke kaʻina ʻana, e kū mai kahi hopena hoʻoneʻe – ma ka ʻili o ka nickel, hoʻololi ke gula i ka nickel, akā i ka wā i hiki ai ka neʻe ʻana i kahi pae, e pau koke ka neʻe ʻana. He kiʻekiʻe ka ikaika o ke gula, ke kūpaʻa abrasion, ke kūpaʻa wela kiʻekiʻe, a ʻaʻole maʻalahi ka oxidize, no laila hiki iā ia ke pale i ka nickel mai ka oxidation a i ʻole passivation, a kūpono no ka hana ʻana i nā noi ikaika kiʻekiʻe.

ʻO ka ʻili PCB i mālama ʻia e ENIG he palahalaha loa a he coplanarity maikaʻi, ʻo ia wale nō ka mea i hoʻohana ʻia no ka ʻili pili o ke pihi. ʻO ka lua, ʻoi aku ka maikaʻi o ka ENIG, e hoʻoheheʻe koke ke gula i loko o ka solder i hoʻoheheʻe ʻia, a laila e hōʻike ana i ka Ni hou.

Nā palena o ENIG:

ʻOi aku ka paʻakikī o ke kaʻina hana a ENIG, a inā makemake ʻoe e hoʻokō i nā hopena maikaʻi, pono ʻoe e kāohi pono i nā ʻāpana kaʻina. ʻO ka mea paʻakikī loa, ʻo ka PCB i mālama ʻia e ENIG e maʻalahi i nā pad ʻeleʻele i ka wā ENIG a i ʻole ke kūʻai ʻana, e loaʻa ana ka hopena pōʻino i ka hilinaʻi o nā hui solder. He paʻakikī loa ka hana hana o ka diski ʻeleʻele. Loaʻa ia ma ke kikowaena o Ni a me ke gula, a ua hōʻike pololei ʻia ʻo ia e like me ka nui o ka oxidation o Ni. ʻO ka nui o ke gula e hoʻopau i nā hui solder a pili i ka hilinaʻi.

Loaʻa i kēlā me kēia kaʻina hana lapaʻau i kona mau hiʻohiʻona ponoʻī, a ʻokoʻa hoʻi ka laulā o ka noi. E like me ka noi ʻana o nā papa like ʻole, koi ʻia nā koi lapaʻau ʻokoʻa. Ma lalo o ka palena o ke kaʻina hana, hana mākou i kekahi manawa i nā manaʻo i nā mea kūʻai aku e pili ana i nā hiʻohiʻona o nā papa. ʻO ke kumu nui ka loaʻa ʻana o kahi lapaʻau kūpono kūpono e pili ana i ka noi huahana a ka mea kūʻai aku a me ka hiki ke kaʻina hana o ka hui. s Koho.