Onse padziko mankhwala a PCB monga kupopera tini, OSP, kumiza golide, ndi zina zotero. “Pamwamba” apa amatanthauza malo olumikizirana pa PCB omwe amapereka kulumikizana kwamagetsi pakati pa zida zamagetsi kapena machitidwe ena ndi kuzungulira kwa PCB, monga mapepala. Kapena malo olumikizirana. Solderability wa mkuwa wopanda kanthu ndi wabwino kwambiri, koma ndi oxidize oxidize pamene akuwululidwa ndi mpweya, ndipo n’zosavuta kuipitsidwa. Ichi ndichifukwa chake PCB iyenera kuthandizidwa pamwamba.

1. Utsire malata (HASL)

Kumene zida za perforated zimalamulira, wave soldering ndiyo njira yabwino kwambiri yolumikizira. Kugwiritsa ntchito ukadaulo wa solder wotentha (HASL, Hot-air solder leveling) ukadaulo wamankhwala wapamtunda ndi wokwanira kukwaniritsa zofunikira pakuwotchera mafunde. Zoonadi, pazochitika zomwe zimafuna mphamvu zolumikizirana kwambiri (makamaka kulumikizana), electroplating ya faifi tambala/golide imagwiritsidwa ntchito nthawi zambiri. . HASL ndiye ukadaulo waukulu wamankhwala omwe amagwiritsidwa ntchito padziko lonse lapansi, koma pali zida zitatu zazikulu zoyendetsera zomwe zimayendetsa makampani amagetsi kuti aganizire njira zina zaukadaulo za HASL: mtengo, zofunikira zanjira zatsopano komanso zofunikira zopanda kutsogolera.

Kuchokera pamawonedwe amtengo wapatali, zida zambiri zamagetsi monga mauthenga a m’manja ndi makompyuta aumwini akukhala katundu wotchuka wa ogula. Pokhapokha pogulitsa pamtengo kapena mitengo yotsika titha kukhala osagonjetseka m’malo ampikisano owopsa. Pambuyo pakupanga ukadaulo wa SMT, mapadi a PCB amafunikira kusindikiza pazenera ndikuwonjezeranso njira zogulitsira panthawi ya msonkhano. Pankhani ya SMA, njira ya chithandizo cha PCB pamwamba imagwiritsabe ntchito teknoloji ya HASL poyamba, koma pamene zipangizo za SMT zikupitiriza kuchepa, mapepala ndi zotsegula za stencil zakhala zing’onozing’ono, ndipo zovuta zaukadaulo wa HASL zawonekera pang’onopang’ono. Mapadi okonzedwa ndi ukadaulo wa HASL sakhala athyathyathya mokwanira, ndipo ma coplanarity sangathe kukwaniritsa zofunikira zamapadi omveka bwino. Zinthu zachilengedwe nthawi zambiri zimangoyang’ana kwambiri momwe mtovu angakhudzire chilengedwe.

2. Organic Solderability Protective Layer (OSP)

Organic solderability preservative (OSP, Organic solderability preservative) ndi ❖ kuyanika organic ntchito kuteteza makutidwe ndi okosijeni wamkuwa pamaso soldering, ndiye kuti, kuteteza solderability wa PCB ziyangoyango kuwonongeka.

Pambuyo pa PCB pamwamba pa mankhwalawa ndi OSP, chinthu chochepa kwambiri cha organic chimapangidwa pamwamba pa mkuwa kuti chiteteze mkuwa ku okosijeni. The makulidwe a Benzotriazoles OSP zambiri 100 A °, pamene makulidwe a Imidazoles OSP ndi thicker, zambiri 400 A °. Filimu ya OSP ndi yowonekera, sikophweka kusiyanitsa kukhalapo kwake ndi maso, ndipo n’kovuta kuzindikira. Panthawi ya msonkhano (reflow soldering), OSP imasungunuka mosavuta mu solder phala kapena acidic Flux, ndipo panthawi imodzimodziyo mkuwa wa mkuwa umawonekera, ndipo potsiriza Sn / Cu intermetallic mankhwala amapangidwa pakati pa zigawo ndi mapepala. Chifukwa chake, OSP ili ndi mikhalidwe yabwino kwambiri ikagwiritsidwa ntchito popangira zowotcherera. OSP ilibe vuto la kuipitsidwa ndi mtovu, choncho ndi yogwirizana ndi chilengedwe.

Zochepa za OSP:

①. Popeza OSP ndi yowonekera komanso yopanda utoto, ndizovuta kuyang’ana, ndipo ndizovuta kusiyanitsa ngati PCB idakutidwa ndi OSP.

② OSP yokha ndi insulated, siyendetsa magetsi. OSP ya Benzotriazoles ndi yochepa kwambiri, yomwe singakhudze kuyesa kwa magetsi, koma kwa OSP ya Imidazoles, filimu yotetezera yomwe imapangidwa imakhala yochuluka kwambiri, yomwe idzakhudza kuyesa magetsi. OSP singagwiritsidwe ntchito pogwira malo olumikizana ndi magetsi, monga makiyibodi a makiyi.

③ Pakuwotcherera kwa OSP, Flux yamphamvu imafunika, apo ayi filimu yoteteza siyingathetsedwe, zomwe zingayambitse kuwonongeka kwa kuwotcherera.

④ Pakusungirako, pamwamba pa OSP sayenera kuwonetsedwa ndi zinthu za acidic, ndipo kutentha sikuyenera kukhala kwakukulu, apo ayi OSP idzasungunuka.

3. Kumizidwa golide (ENIG)

Chitetezo cha ENIG:

Ni/A imakutidwa pamwamba pa mkuwa ndi njira ya mankhwala. Makulidwe a mkati mwa wosanjikiza wa Ni nthawi zambiri amakhala 120 mpaka 240 μin (pafupifupi 3 mpaka 6 μm), ndipo makulidwe amtundu wakunja wa Au ndi woonda, nthawi zambiri 2 mpaka 4 μm (0.05 mpaka 0.1 μm). Ni amapanga chotchinga wosanjikiza pakati pa solder ndi mkuwa. Pa soldering, Au panja adzasungunuka mwamsanga mu solder, ndipo solder ndi Ni kupanga Ni / Sn intermetallic pawiri. Kupaka golide kunja ndikuteteza Ni oxidation kapena passivation panthawi yosungira, kotero kuti golide wosanjikiza ayenera kukhala wandiweyani mokwanira ndipo makulidwe asakhale ochepa kwambiri.

Kumizidwa kwa golide: Pochita izi, cholinga chake ndikuyika kansalu kakang’ono koteteza golide. Makulidwe a golide wamkulu sayenera kukhala wandiweyani kwambiri, apo ayi zolumikizira za solder zimakhala zolimba kwambiri, zomwe zingakhudze kwambiri kudalirika kwa kuwotcherera. Monga plating ya nickel, golide womiza ali ndi kutentha kwakukulu kogwira ntchito komanso nthawi yayitali. Panthawi yothira, kusuntha kudzachitika-pamtunda wa faifi tambala, golide amalowa m’malo mwa nickel, koma kusamutsidwa kukafika pamlingo wina, kusamukako kumangoyima. Golide ali ndi mphamvu zambiri, kukana kwa abrasion, kukana kutentha kwambiri, ndipo sikophweka kuti oxidize, kotero amatha kuteteza faifi tambala kuchokera ku okosijeni kapena passivation, ndipo ndi yoyenera kugwira ntchito muzochita zamphamvu kwambiri.

Malo a PCB omwe amathandizidwa ndi ENIG ndiwathyathyathya kwambiri ndipo ali ndi coplanarity yabwino, yomwe ndi yokhayo yomwe imagwiritsidwa ntchito polumikizana ndi batani. Kachiwiri, ENIG ali ndi solderability wabwino kwambiri, golide amasungunuka mwachangu mu solder wosungunuka, potero kuwulula Ni.

Zochepa za ENIG:

Njira ya ENIG ndiyovuta kwambiri, ndipo ngati mukufuna kupeza zotsatira zabwino, muyenera kuwongolera magawo azinthu. Chovuta kwambiri ndichakuti mawonekedwe a PCB omwe amathandizidwa ndi ENIG amakonda kukhala ndi mapepala akuda nthawi ya ENIG kapena soldering, zomwe zingakhudze kwambiri kudalirika kwa ma solder. Njira yopangira diski yakuda ndi yovuta kwambiri. Imapezeka pa mawonekedwe a Ni ndi golide, ndipo imawonetsedwa mwachindunji ngati makutidwe ndi okosijeni a Ni. Golide wochuluka kwambiri adzasokoneza ma solder ndi kukhudza kudalirika.

Njira iliyonse yochizira pamwamba imakhala ndi mawonekedwe ake apadera, komanso kuchuluka kwa ntchito kumasiyananso. Malinga ndi kagwiritsidwe ntchito ka matabwa osiyanasiyana, zofunikira zosiyanasiyana zamankhwala zimafunikira. Pansi pa malire a kupanga, nthawi zina timapanga malingaliro kwa makasitomala potengera mawonekedwe a matabwa. Chifukwa chachikulu ndikukhala ndi chithandizo choyenera chapamwamba potengera zomwe kasitomala akufuna komanso momwe kampaniyo imagwirira ntchito. s Kusankha.