Izinzuzo kanye nokubi kokuqedwa kwe-PCB surface

I-Printed Circuit Boards (PCBs) ayinsika yezinto zikagesi zesimanje, ezitholakala kukho konke kusukela kuma-smartphones kuya kumasathelayithi. Ukusebenza nokuthembeka kwazo kuncike kakhulu kwikhwalithi yokuqedwa kwendawo esetshenzisiwe. Lo mhlahlandlela uhlola ubunkimbinkimbi bokuqedwa kwe-PCB, udingida izinhlobo zazo, izinzuzo, ububi, kanye nesayensi engemuva kokusebenza kwazo.

Isingeniso se-PCB Surface Finishes

Ukuqedwa kobuso kuyisici esibalulekile sokwenziwa kwebhodi lesifunda eliphrintiwe (PCB). Banikeza imisebenzi eminingi:

• Vikela ithusi ekungcoleni nasekugqwaleni
• Nikeza ukuthengiselana okuhle kokunamathiselwe kwengxenye
• Qinisekisa conductivity phakathi kwamalunga
• Gwema ukuguga kanye nemihuzuko ngesikhathi sokuhlanganisa nokusebenzisa
• Vumela ukuhlolwa nokuhlolwa okusebenzayo

Lesi sihloko sihlola izinketho ezijwayelekile zokuqeda umphezulu we-PCB ngokujulile, izinzuzo kanye nemikhawulo yazo, kanye nemihlahlandlela yokukhetha.

I-Hot Air Solder Leveling (HASL)

I-HASL iyindlela evamile yokuqeda ama-PCB, asetshenziswa kusukela ngeminyaka yawo-1960. Izinyathelo zihlanganisa:

1. Isicelo se-Flux sokususa ama-oxide futhi sithuthukise ukusabalala kwe-solder.
2. Ukucwilisa amabhodi kubhavu we-solder encibilikisiwe (imvamisa i-tin-lead).
3. Ukulinganisa i-solder ewuketshezi usebenzisa amajethi omoya oshisayo noma i-nitrogen uma kuhoxiswa.

Lokhu kushiya ukumbozwa kwe-solder kumaphedi e-PCB nemikhondo. Imingcele yenqubo ebalulekile yizinga lokushisa lokugeza le-solder, isikhathi sokuchayeka, ingcindezi yommese womoya kanye nezinga lokushisa.

Ubukhulu be-HASL busukela ku-1-70 μm. Ubukhulu obujwayelekile bungama-20-30 μm. Ukuqedwa kwe-HASL okufiphele kunikeza ukuthengiselana okuhle kakhulu. I-solder coating ivimbela i-oxidation futhi ivumela ukwakheka kwamalunga athembekile e-solder.

Kodwa-ke, kukhona ukungalungi kwe-HASL:

• Ukushuba okungeyona into efanayo: Umthelela we-meniscus uholela ekufakweni kwediphozithi engalingani.
• Impilo yeshelufu enomkhawulo: Isiphetho sigcina si-oxidize ngokuhamba kwesikhathi.
• Ayilungele iphimbo elihle: Ingozi yokuhlanganisa i-solder kuma-PCB aminyene.
• Ukugoqa kwamabhodi amancane: Amazinga okushisa aphezulu angabangela i-warpage.
• I-Flux residue trapping: I-Flux ingabanjwa ngaphansi kwe-solder.
• Izinselelo ze-DFM: I-HASL ingadala izinkinga zokwenziwa.

Ukulungiswa njengokunciphisa izinga lokushisa lokugeza nge-solder kusiza ukuthuthukisa inqubo. Sekukonke, i-HASL inikeza ukusebenza okwamukelekayo ngezindleko eziphansi. Kodwa izinselele zikhona emiklamo yesimanje ye-pitch emihle.

I-Organic Solderability Preservatives (OSP)

Izembatho ze-OSP ziyizinto eziphilayo ezisetshenziswa endaweni ye-PCB. Aqukethe amakhemikhali afana ne-imidazoles noma i-benzimidazole esabela nge-copper oxide ukwenza amafilimu amancane e-polymeric.

Ugqinsi lwesendlalelo se-OSP ngu-0.1-0.2 μm. Izembatho zisebenza njengesivikelo sesikhashana ekulweni ne-oxidation. Kodwa futhi kufanele ikhishwe ngesikhathi sokudayiswa ukuze kuvezwe ithusi elingenalutho.

Izinzuzo ze-OSP:

• Inqubo elula ngokufafaza noma ukucwilisa
• Isiphetho esibushelelezi esiqhathaniswa ne-ENIG
• Izindleko eziphansi futhi ezingenamthofu
• Ifanele iphimbo elihle

Okumbi:

• Impilo yeshelufu enomkhawulo
• Izinkinga zokusebenza kabusha
• Ukuhlola optical okunzima
• Ukumelana okuphansi ezindaweni ezinokhahlo

I-OSP ilungele izinhlelo zokusebenza eziningi ze-elekthronikhi zabathengi. Kepha izimfuno zokuthembeka okuphezulu zingadinga ezinye iziqephu.

I-Silver yokucwiliswa kanye ne-Immersion Tin

Isiliva lokucwiliswa kanye nethini kuyizingqimba zensimbi ezifakwe ngamakhemikhali kuma-PCB ngokusabela kokugudluzwa. Ama-PCB acwiliswa ezixazululweni ezishisayo ngesiliva noma ama-tin ions. Ama-ion athatha indawo yama-athomu ethusi, afaka amabhodi.

Ukujiya okujwayelekile kungu-0.1-0.3 μm wesiliva lokucwiliswa kanye no-0.1-0.8 μm wethini lokucwiliswa.

Izinzuzo:

• I-solderability enhle kakhulu
• I-lead-free futhi ithobela i-RoHS
• Izindleko eziphansi kuneziqediwe zegolide
• Ukucubungula okulula kunokwemboza okungenagesi

Okumbi:

• Ukunciphisa kanye ne-oxidation ngokuhamba kwesikhathi
• Impilo yeshelufu enomkhawulo
• Ukubhuqa kuyingozi ngethayela
• Kudingeka kabusha okwengeziwe ngesiliva

Lokhu kuqedwa kufanela ama-electronics amaningi angabizi kakhulu. Kodwa kukhona ukukhathazeka kokuzinza ngemikhiqizo yesikhathi eside.

I-Electroless Nickel Immersion Gold (ENIG)

I-ENIG ihlanganisa ukufakwa kwe-nickel yokuqala engena-electroless okulandelwa ukucwiliswa kongqimba oluncane lwegolide. Ugqinsi lwe-nickel luwugqinsi oluyi-3-6 μm kanti igolide lingu-0.05-0.15 μm.

I-nickel isebenza njengesendlalelo sesithiyo sokusabalalisa futhi inikeza isisekelo esihle sokunamathisela. Igolide linikeza ukumelana nokugqwala okuhle kakhulu kanye ne-conductivity.

Izinzuzo ze-ENIG:

• Impilo yeshelufu enhle kakhulu
• Gqoka ukuvikeleka kungqimba lwegolide
• Ihambisana nomthofu
• Isiphetho esilinganayo nesibushelelezi

Okumbi:

• Izindleko eziphezulu ngenxa yegolide
• Ukulawulwa kwenqubo okuqinile kuyadingeka
• Ukulahleka kwe-solderability okungenzeka ngokuhamba kwesikhathi
• Idiphozithi ye-Brittle ebugqileni obungaphezu kuka-0.5 μm

I-ENIG ilungele ukuthembeka okuphezulu kanye nama-PCB ebanga lezempi lapho izindleko zingesona isithiyo.

I-Electrolytic Nickel/Igolide (Igolide Eliqinile/Igolide Elithambile)

I-Electrolytic nickel/igolide ibhekisela ku-nickel eyenziwe nge-electroplated nezingubo zegolide kuma-PCB. Kunezinhlobo ezimbili eziyinhloko:

Igolide Eliqinile

Igolide eliqinile linokuqukethwe okuphezulu kwe-nickel noma i-cobalt, okuholela ekuhlanzekeni okuphansi okungama-90-95%. Iyaqina futhi ayigugi.

Igolide eliqinile livame ukusetshenziselwa:

• Izixhumi zomphetho neminwe - Imelana nemijikelezo yokukhwelana
• Amaphoyinti okuxhumana - Iphatha ama-arc ashintshayo
• Izixhumi – Imelana nemihuzuko

Ubukhulu bungasukela ku-2-10 μm ngokuya ngezidingo zokugqoka.

Igolide Elithambile

Igolide elithambile liqukethe >99% igolide elimsulwa. Inikeza ukuqina okuphezulu nokumelana nokugqwala. Amasudi egolide athambile:

• I-wire bonding - Inika amandla ukubopha okuphezulu kwesivuno
• I-Soldering - Inikeza ukumanzisa okuhle kakhulu

Ubukhulu obujwayelekile bungu-0.05-2 μm.

Izinzuzo ze-Electrolytic Nickel/Gold

• Ukujiya okwenziwe ngokwezifiso njengoba kudingeka
• Inketho yegolide eliqinile koxhumana nabo/izixhumi
• Ihambisana nomthofu

Okumbi

• Kubiza kakhulu, ikakhulukazi igolide elithambile
• I-solderability yokuqala ephansi yegolide eliqinile
• I-Brittle ezindaweni eziphakeme kakhulu
• Kudingeka ukulandelelwa okwengeziwe kweminwe yegolide

I-Electrolytic nickel/igolide ivumela ukusebenza okuhle kodwa ngezindleko eziphezulu.

I-Electroless Nickel Electroless Palladium Immersion Gold (ENEPIG)

I-ENEPIG ithuthukisa i-ENIG ngokwengeza isendlalelo se-electroless palladium phakathi kwe-nickel negolide. Lokhu kuthuthukisa futhi ukumelana nokugqwala.

Ugqinsi lwesendlalelo se-nickel ngu-~3-6 μm. I-Palladium ingu-~0.1-0.5 μm kuyilapho igolide ingu-0.02-0.1 μm.

Izinzuzo ze-ENEPIG

• Iqeda ingozi yephedi emnyama nge-ENIG
• I-wire bondebility engcono kune-ENIG
• Ukugqwala okuphezulu nokumelana ne-oxidation
• Impilo yeshelufu ende

Okumbi

• Ukulawula inqubo eyinkimbinkimbi kakhulu
• Izindleko eziphezulu ngenxa yokufakwa kwezendlalelo eziningi
• Inqubo entsha, isakhula
• Ngokuvamile idinga i-flash gold plating yokugcina

I-ENEPIG inikeza ukuvikeleka okuphezulu kwezindawo ezinokhahlo. Kodwa futhi ukuphela kwe-PCB ebiza kakhulu.

Imaski Ye-Solder Ekwazi Ukuthwebula Uketshezi (LPSIM)

I-LPSIM noma i-Liquid Photoimageable Coatings (LPC) amamaski e-solder elapheka e-UV. Basebenza njengesiphetho sokuvikela unomphela, basusa isidingo sezingubo ezihambisanayo.

I-LPSIM isetshenziswa ngokuphrinta isikrini noma ngokufafaza. Ivezwa futhi yelashwe ukuze yakhe ungqimba oluqinile lwe-polymeric oluvikelayo.

Izinzuzo ze-LPSIM:

• Isivikelo esihle kakhulu emvelweni/emihuzuko
• Ukuhlanganiswa kwenqubo okuthuthukisiwe
• Ukulungiswa okuphezulu kunemaski yefilimu eyomile
• Imelana nokugeleza kabusha okuningi

Okumbi:

• Ukuhlolwa kwangemva kokufaka isicelo okunomkhawulo
• Izinyathelo zokucubungula eziningi eziyinkimbinkimbi
• Izindleko eziphezulu zempahla kanye nokucubungula
• Izinkinga zokumelana nokushaqeka okushisayo

Sekukonke, i-LPSIM ihlinzeka ngokuvikeleka okuthembekile kokusebenza okuphezulu. Kodwa ngezindleko eziphakeme kunezendabuko ze-solder masks.

Isiphetho

I-PCB surface finish inomthelela omkhulu ekwenziweni, izinqubo zokudayiswa, ukungabonakali, ukwethembeka kanye nezindleko. Ukuthuthukisa isiphetho kudinga ukuhlola ukuhwebelana okubalulekile ngokusekelwe endaweni yomjikelezo wokuphila womkhiqizo, ikhwalithi eqondiwe kanye nesabelomali. Lokhu kubuka konke kunikeza abaklami umbono ophelele ekukhetheni isiphetho esifanele ngezidingo zabo zohlelo lokusebenza.

Posts Related

1.Iyini Inqubo Yokukhiqiza I-PCB?
2. Yini ama-PCB?
3. Umhlahlandlela Ophelele we-PCB Surface Finishes: Ukukhethwa, Izakhiwo, kanye Nokucatshangelwa Kokwethenjelwa