Melemo le go tlhoka mesola ea PCB holim'a qetello

Printed Circuit Boards (PCBs) ke mokokotlo oa lisebelisoa tsa elektronike tsa morao-rao, tse fumanoang nthong e 'ngoe le e' ngoe ho tloha ho li-smartphone ho isa ho lisathelaete. Ts'ebetso ea bona le ts'epahalo ea bona e itšetlehile haholo ka boleng ba sephetho sa bokaholimo bo sebelisitsoeng. Tataiso ena e shebana le ho rarahana ha liphetho tsa PCB, ho bua ka mefuta ea tsona, melemo, mathata, le mahlale a ts'ebetsong ea tsona.

Kenyelletso ea PCB Surface Finishes

Lithako tse holimo ke karolo ea bohlokoahali ea boto ea potoloho e hatisitsoeng (PCB). Ba sebeletsa mesebetsi e mengata:

• Sireletsa koporo ho oxidation le ho bola
• Fana ka solderability e ntle bakeng sa lihokelo tsa likarolo
• Netefatsa conductivity pakeng tsa manonyeletso
• Hanela ho khathala le ho khojoa nakong ea kopano le tšebeliso
• Lumella tlhahlobo le tlhahlobo e sebetsang

Sengoliloeng sena se hlahloba likhetho tse tloaelehileng tsa ho qetela tsa PCB ka botebo, melemo le mefokolo ea tsona, le litataiso tsa khetho.

Mocheso oa Solder Leveling (HASL)

HASL ke mokhoa o tloaelehileng oa ho qeta li-PCB, o sebelisitsoeng ho tloha lilemong tsa bo-1960. Mehato e kenyelletsa:

1. Sesebelisoa sa Flux ho tlosa li-oxide le ho ntlafatsa ho ata ha solder.
2. Ho qoelisa mapolanka ka bateng e qhibilihisitsoeng ea solder (hangata tin-lead).
3. Ho leka-lekanya solder ea metsi ka ho sebelisa jete tsa moea o chesang kapa naetrojene ha e ntšoa.

Sena se siea seaparo sa solder holim'a liphahlo tsa PCB le mesaletsa. Lintlha tsa bohlokoa tsa ts'ebetso ke mocheso oa ho hlapa oa solder, nako ea ho pepeseha, khatello ea thipa ea moea le mocheso.

Botenya ba HASL bo tloha ho 1-70 μm. Botenya bo tloaelehileng ke 20-30 μm. Qetello e lerootho ea HASL e fana ka solderability e ntle haholo. Ho roala ka solder ho thibela oxidation le ho lumella ho thehoa ha manonyeletso a ka tšeptjoang a solder.

Leha ho le joalo, ho na le mathata a mang a HASL:

• Botenya bo sa lekanang: Phello ea meniscus e lebisa ho li-deposit tse sa lekanang.
• Bophelo bo fokolang ba shelofo: Qetello e qetella e oxidize ha nako e ntse e feta.
• Ha e tšoanelehe bakeng sa molumo o motle: Kotsi ea ho koala borokho ho li-PCB tse teteaneng.
• Warping ea mapolanka a masesaane: Mocheso o phahameng oa mocheso o ka baka warpage.
• Ho ts'oaroa ha masala a Flux: Flux e ka ts'oaroa ka tlas'a solder.
• Liphephetso tsa DFM: HASL e ka theha mathata a tlhahiso.

Liphetoho tse kang ho fokotsa mocheso oa ho hlapa ka solder li thusa ho ntlafatsa mokhoa ona. Ka kakaretso, HASL e fana ka ts'ebetso e amohelehang ka theko e tlase. Empa mathata a teng bakeng sa meralo e metle ea sejoale-joale.

Organic Solderability Preservatives (OSP)

Liaparo tsa OSP ke metsoako ea tlhaho e sebelisoang holim'a PCB. Li na le lik'hemik'hale tse kang imidazoles kapa benzimidazole tse sebetsanang le koporo oxide ho etsa lifilimi tse tšesaane tsa polymeric.

Botenya ba lera la OSP ke 0.1-0.2 μm. Liaparo li sebetsa e le tšireletso ea nakoana khahlanong le oxidation. Empa hape e tlameha ho tlosoa nakong ea soldering ho pepesa koporo e se nang letho.

Melemo ea OSP:

• Mokhoa o bonolo ka ho fafatsa kapa ho qoelisoa
• Qetello e boreleli e bapisoa le ENIG
• Theko e tlase ebile ha e na loto
• E loketse molumo o motle

go tlhoka mesola:

• Bophelo ba shelofo bo lekanyelitsoeng
• Mathata a ho sebetsa hape
• Tlhahlobo e thata ea optical
• Khanyetso e tlase ho maemo a thata

OSP e loketse lits'ebetso tse ngata tsa elektroniki tsa bareki. Empa litlhoko tse phahameng tsa ts'epo li ka hloka liphetho tse ling.

Silivera ea ho Koebetsoa le Tin ea ho Koa

Silevera e qoelisoang le thini ke likarolo tsa tšepe tse kentsoeng ka lik'hemik'hale ho li-PCB ka karabelo ea phalliso. Li-PCB li inetsoe ka har'a litharollo tse futhumetseng ka li-ion tsa silevera kapa tsa tin. Li-ion li nka sebaka sa liathomo tsa koporo, li tšela mapolanka.

Botenya bo tloaelehileng ke 0.1-0.3 μm bakeng sa silevera ea ho qoelisoa le 0.1-0.8 μm bakeng sa thini ea ho qoelisoa.

le menyetla:

• Excellent solderability
• Ha e na lead ebile e tsamaellana le RoHS
• Litsenyehelo tse tlase ho feta likhau tsa khauta
• Tshebetso e bonolo ho feta electroless plating

go tlhoka mesola:

• Ho senyeha le oxidation ka nako
• Bophelo ba shelofo bo lekanyelitsoeng
• Ho ipeha kotsing ka thini
• Rework e eketsehileng e hlokahalang ka silevera

Lisebelisoa tsena li lumellana le lisebelisoa tse ngata tsa elektronike tse sa bitseng chelete e ngata. Empa mathata a botsitso a teng bakeng sa lihlahisoa tsa nako e telele.

Electroless Nickel Immersion Gold (ENIG)

ENIG e kenyelletsa plating ea pele ea nickel e se nang motlakase e lateloang ke ho qoelisoa ha lesela le tšesaane la khauta. Botenya ba nickel ke 3-6 μm ha khauta e le 0.05-0.15 μm.

Nickel e sebetsa e le lera le thibelang phetisetso 'me e fana ka motheo o motle oa ho kopanya. Khauta e fana ka khanyetso e ntle haholo ea kutu le conductivity.

Melemo ea ENIG:

• Bophelo bo botle ba sethala
• Apara tšireletso ho tloha lera la khauta
• E lumellana le lead
• Phello e tšoanang le e boreleli

go tlhoka mesola:

• Litsenyehelo tse phahameng ka lebaka la khauta
• Ho hlokahala taolo e tiileng ea tšebetso
• Tahlehelo e ka bang teng ea solderability ka nako
• Brittle deposits ka botenya bo fetang 0.5 μm

ENIG e loketse li-PCB tse tšepahalang haholo le tsa sesole moo litšenyehelo e seng tšitiso.

Electrolytic Nickel/Gold (Hard Gold/Soft Gold)

Electrolytic nickel/ gold e bua ka nickel e entsoeng ka electroplated le liphahlo tsa khauta ho PCBs. Ho na le mefuta e 'meli ea mantlha:

Khauta e Thata

Khauta e thata e na le nickel e phahameng kapa cobalt content, e bakang bohloeki bo tlase ba hoo e ka bang 90-95%. E thata le ho feta, 'me ha e phele.

Khauta e thata e sebelisoa hangata bakeng sa:

• Lihokelo le menoana - E mamella linako tsa ho nyalana
• Lintlha tsa ho ikopanya - E sebetsana le li-arcs tse fetohang
• Lihokelo – E hanana le abrasion

Botenya bo ka tloha ho 2-10 μm ho latela litlhoko tsa moaparo.

Khauta e Bonolo

Khauta e bonolo e na le > 99% ea khauta e hloekileng. E fana ka conductivity e phahameng ka ho fetisisa le ho hanyetsa kutu. Lisutu tsa khauta tse bonolo:

• Khokahano ea mohala - E etsa hore ho be le kotulo e ngata
• Soldering - E fana ka mongobo o motle haholo

Botenya bo tloaelehileng ke 0.05-2 μm.

Melemo ea Electrolytic Nickel / Khauta

• Customisable botenya ha ho hlokahala
• Khetho ea khauta e thata bakeng sa mabitso / lihokelo
• E lumellana le lead

go tlhoka mesola

• E theko e boima haholo, haholo-holo khauta e bonolo
• Theko e tlase ea pele ea solderability ea khauta e thata
• Brittle ka botenya bo phahameng
• Mesaletsa e eketsehileng e hlokahalang bakeng sa menoana ea khauta

Electrolytic nickel / khauta e lumella ts'ebetso e ntlafalitsoeng empa ka litšenyehelo tse holimo.

Electroless Nickel Electroless Palladium Immersion Gold (ENEPIG)

ENEPIG e ntlafatsa ENIG ka ho eketsa lera le se nang motlakase pakeng tsa nickel le lijalo tsa khauta. Sena se ntlafatsa ho hanyetsa kutu.

Botenya ba lera la nickel ke ~ 3-6 μm. Palladium ke ~ 0.1-0.5 μm ha khauta e le 0.02-0.1 μm.

Melemo ea ENEPIG

• E felisa kotsi ea pad e ntšo ka ENIG
• Boitlamo bo betere ba terata ho feta ENIG
• Ho bola ho hoholo le ho hanyetsa oxidation
• Bophelo ba shelofo e telele

go tlhoka mesola

• Taolo ea ts'ebetso e rarahaneng haholo
• Litšenyehelo tse phahameng ka lebaka la li-depositions tse ngata
• Ts'ebetso e ncha, e ntseng e hola
• Hangata e hloka ho roala khauta e khanyang ea ho qetela

ENEPIG e fana ka tšireletso e phahameng bakeng sa tikoloho e thata. Empa hape ke pheletso e turang haholo ea PCB.

Li-Mask tsa Solder tse ka Sebetsang Mokelikeli (LPSIM)

LPSIM kapa Liquid Photoimageable Coatings (LPC) ke limaske tsa solder tse phekolehang ka UV. Li sebetsa e le tšireletso e sa feleng, e felisang tlhokahalo ea ho roala ka mokhoa o ts'oanang.

LPSIM e sebelisoa ka khatiso ea skrine kapa ho fafatsa. E pepesitsoe le ho phekoloa ho theha lera le thata le sireletsang la polymeric.

Melemo ea LPSIM:

• Tšireletso e babatsehang khahlanong le tikoloho / abrasion
• Khokahano e ntlafalitsoeng ea ts'ebetso
• Qeto e phahameng ho feta mask a filimi e omileng
• E mamella li-reflows tse ngata

go tlhoka mesola:

• Tlhahlobo e fokolang ea kamora kopo
• Mehato e rarahaneng ea ho sebetsa ka bongata
• Lisebelisoa tse phahameng le litšenyehelo tsa ho sebetsa
• Mathata a ho hanyetsa mocheso oa mocheso

Ka kakaretso, LPSIM e fana ka ts'ireletso ea ts'ebetso e phahameng e tšepahalang. Empa ka theko e phahameng ho feta limaske tse tloaelehileng tsa solder.

fihlela qeto e

Qetello ea bokaholimo ba PCB e na le tšusumetso e kholo ts'ebetsong ea tlhahiso, lits'ebetso tsa soldering, ho hlaka, ho ts'epahala le litšenyehelo. Ho ntlafatsa sephetho ho hloka ho lekola litšebelisano tsa mantlha ho ipapisitsoe le tikoloho ea bophelo ba sehlahisoa, lipehelo tsa boleng le tekanyetso. Tlhaloso ena e fana ka baqapi pono e pharaletseng ea ho khetha qetello e nepahetseng bakeng sa litlhoko tsa bona tsa kopo.

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