Ho Khetha Substrate e Nepahetseng bakeng sa Moralo oa PCB oa Maqhubu a Phahameng

Hobaneng ha Khetho ea Substrate e le Bohlokoa ho Moralo oa PCB oa Maqhubu a Phahameng

Letšoao la Botšepehi le Tšusumetso ea Lintho

Karolo e phahameng ea PCB e khetholla ka ho toba liparamente tsa motlakase tse laolang boleng ba lets'oao. Tangent ea tahlehelo ea dielectric e ama tahlehelo ea ho kenngoa ka ho qhalana ha matla, ha tieho ea ho phatlalatsoa e fapana le motso o sekoere oa kamehla ea dielectric. Taolo ea impedance e itšetlehile ka thepa e tsitsitseng ea dielectric ho pholletsa le spectrum ea maqhubu, kaha esita le liphetoho tse nyane tsa Dk li ka fetola impedance e ikhethang ka li-ohms tse 'maloa, tsa senya marang-rang a tsamaellanang le ho baka lipontšo.

Phapang Pakeng tsa Moralo oa Lebelo le Phahameng ka ho Fetisisa

Moralo oa lebelo le phahameng oa dijithale o shebana le sekhahla sa sekhahla le taolo ea boinahano ka taolo ea ho se tsoelepele ea impedance. Li-circuits tse phahameng tsa RF le microwave li etelletsa pele phokotso ea tahlehelo ea ho kenya, botsitso ba mohato, 'me e laoloa ke dielectric kamehla ho pholletsa le bandwidth ea ts'ebetso. Le ha sehokelo sa dijithale sa 10 Gbps se ka mamella tahlehelo e leka-lekaneng ea substrate, sehlopha sa 28 GHz se hloka lintlha tse ka tlase ho 0.002 ho boloka phaello e amohelehang le lerata.

Mathata a Tloaelehileng a Moralo

Khetho e sa nepahalang ea substrate ea PCB e nang le maqhubu a phahameng e iponahatsa e le tahlehelo e feteletseng ea ho kenya e fokotsang tekanyetso ea lihokelo le sebaka sa sistimi. Ho sisinyeha ha mekhahlelo ka mocheso ho baka liphoso tsa ho tsamaisa mahlaseli ka har'a li-array tse arotsoeng ka mekhahlelo le ho thothomela ha nako litsamaisong tsa ho nka lisampole. Ho se lumellane ha impedance ho tsoa thepa ea dielectric e sa tsitsang ho hlahisa maqhubu a emeng tahlehelo e mpe ea ho khutla, ha thepa e nang le tahlehelo e phahameng e fetola matla a lets'oao mocheso, e leng se behang ts'ebetso ea motlakase le taolo ea mocheso kotsing. Ha u khetha li-substrate tsa AD300 bakeng sa liboto tsa potoloho tsa RF , netefatsa tlhaloso e nepahetseng ea thepa, botenya bo fumanehang le tsela ea ts'ebetso pele u amohela stackup.

Lintlha tsa bohlokoa tsa lisebelisoa bakeng sa li-substrates tsa PCB tsa High Frequency

Dielectric Constant (Dk) le Ho tsitsa ha eona khafetsa

Dielectric kamehla e etsa qeto ea geometry ea phetisetso e hlokahalang ho fihlela sepheo sa sepheo. Sesebelisoa sa microstrip sa 50-ohm ka Dk 3.5 se hloka litekanyo tse fapaneng tsa bophara ho isa ho bophahamo ho feta sephetho se ts'oanang sa lik'hemik'hale tsa ceramic tsa Dk 10. Lisebelisoa tsa "Premium high frequency PCB substrate" li hlakisa mamello ea Dk ka har'a ± 0.05 le frequency coefficients ka tlase ho 50 ppm/GHz ho netefatsa ts'ebetso e sa lebelloang ho tloha DC ka maqhubu a millimeter-wave.

Dissipation Factor (Df kapa Loss Tangent)

Dissipation factor e lekanya tahlehelo ea dielectric ka karolelano ea lintho tse inahaneloang le likarolo tsa 'nete tsa tumello. Ho 10 GHz, substrate e nang le Df ea 0.004 e bonts'a tahlehelo ea dielectric habeli ha e bapisoa le thepa ea Df 0.002. Li-substrates tsa morao-rao tse phahameng tsa PCB li finyella lintlha tsa ho senya tse tlaase ho 0.0009 ho lisebelisoa tse thehiloeng ho PTFE, tse nolofalletsang li-circuits tsa millimeter-wave tse nang le litekanyetso tse amohelehang tsa tahlehelo ea ho kenya.

Thermal le Mechanical Thepa

Mekhahlelo ea bohlokoa ea mocheso bakeng sa ho ts'epahala ha substrate ea PCB e phahameng haholo:

• CTE e tšoana - Coefficient ka hare ho 5-10 ppm/°C ea koporo e thibela ho phatloha ha moqomo ka ho palama baesekele
• Mocheso oa phetoho ea khalase - Tg e ka holimo ho 180 ° C e mamella kopano e se nang loto e nang le moeli o lekaneng
• Ho khanna ho chesang - Maemo a fetang 1 W/mK a thusa meralo ea amplifier ea matla ntle le libaka tse hotspots
• Thermal botsitso - Paramethara e nyane ea motlakase e hoholeha ho pholletsa le -40°C ho ea ho +125°C sebaka se sebetsang

Copper Surface Rughness le Litahlehelo tsa Conductor

Ho maqhubu a ka holimo ho 5 GHz, phello ea letlalo e shebana le hona joale moo litlhōrō tsa mahoashe li eketsang khanyetso e matla haholo. Koporo e tloaelehileng ea electrodeposited e nang le 5-7 micrometer RMS roughness e ka ba habeli tahlehelo ea conductor ha e bapisoa le sub-micrometer boreleli foil. Lisebelisoa tsa "Premium frequency high frequency" tsa PCB li sebelisa li-foil tse phekotsoeng ka morao ho fokotsa ts'ebetso ena, joalo ka sekala sa kotlo e boima ka "square root of frequency".

Kakaretso ea Lisebelisoa tsa Common High Frequency PCB Substrate

PTFE (Teflon) le PTFE e Tlatsitsoeng ka Ceramic

Di-substrate tse hlwekileng tsa PTFE di fana ka di-factor tse fokolang haholo tsa ho qhalana ha motlakase tse ka bang 0.0010 le botsitso bo botle ba dielectric ho pholletsa le mocheso le maqhubu. Di-filler tsa ceramic di fetola dielectric constant ho tloha ho 2.1 ya tlhaho ya PTFE ho ya ho boleng bo entsweng pakeng tsa 2.2 le 10.2, ho nolofalletsa meralo ya impedance e laolwang. Disebediswa tsena di ipabola haholo ditshebedisong tsa maqhubu a millimeter ho kenyeletswa di-transceivers tsa satellite, di-module tsa radar, le di-antenna arrays tsa 5G tse kgolo tsa MIMO.

Letoto la Rogers RO4000 / RO4350B

Lelapa la RO4000 le sebelisa li-laminate tsa hydrocarbon-ceramic tse bolokang ho lumellana le lisebelisoa tse tloaelehileng tsa ts'ebetso ea FR-4. RO4350B e fihlella 3.48 ka ntlha ea ho qhala e ka bang 0.0037 ho 10 GHz, e fanang ka ts'ebetso e betere haholo ho feta FR-4 e ntlafalitsoeng. Tekanyo ena e etsa hore e be substrate ea PCB e ratoang haholo bakeng sa liteishene tsa motheo tsa 5G, radar ea likoloi, le lits'ebetso tsa backplane tse lebelo le phahameng tse hlokang ho rarahana ha mekhahlelo e mengata.

Lisebelisoa tsa Ceramic-Thehiloeng le Hydrocarbon-Ceramic Laminates

Li-substrate tsa ceramic tsa Alumina le aluminium nitride li fana ka conductivity ea mocheso e fetang 20 W/mK hammoho le li-constant tsa dielectric ho tloha ho 9 ho isa ho 10, e leng se loketseng li-amplifiers tsa RF tse matla haholo. Li-composites tsa hydrocarbon-ceramic li fana ka litharollo tse mahareng tse nang le conductivity ea mocheso e ka bang 0.6-0.8 W/mK, e lekaneng bakeng sa matla a mahareng a matla. Likhetho tsena tsa substrate tsa PCB tse nang le maqhubu a phahameng li nolofalletsa meralo e nyane ha li ntse li laola ho qhala ha mocheso lits'ebetsong tsa amplifier ea motlakase.

Lisebelisoa tsa Epoxy le Hydrocarbon tse fetotsoeng

Panasonic Megtron 6 le thepa e tšoanang e thehiloeng ho hydrocarbon li fihlella lintlha tsa ho qhalana hoo e ka bang 0.002-0.004 ho 10 GHz ka boenjiniere ba polymer. Li-substrate tsena li sebeletsa lits'ebetso tsa PCB tsa maqhubu a phahameng a mahareng ho tloha ho 2 ho isa ho 20 GHz moo kutloisiso ea litšenyehelo e thibelang litharollo tse hloekileng tsa PTFE empa litlhoko tsa ts'ebetso li feta bokhoni ba FR-4. E lumellana le ts'ebetso e tloaelehileng ea mekhahlelo e mengata, e lumellana le likhokahano tsa setsi sa data le li-module tsa radar tsa likoloi.

Mefuta e ntlafalitsoeng ea FR-4 le High-Tg FR-4

Mabaka a tloaelehileng a ho qhala ha FR-4 a ka bang 0.020 ho 1 GHz a fokotsa bandwidth e ka sebelisoang ho fihlela ka tlase ho 3 GHz bakeng sa litsela tsa bohlokoa tsa matshwao. Mefuta e fapaneng ea High-Tg e nang le litsamaiso tse ntlafalitsoeng tsa resin e fokotsa Df ho isa ho 0.010-0.015, e atolosa maqhubu a thusang ho fihlela ho 5-6 GHz. FR-4 e ntlafalitsoeng e sebetsa e le thepa e amohelehang ea PCB ea maqhubu a phahameng bakeng sa kabo ea oache le li-interface tsa memori moo lithibelo tsa litšenyehelo li busang.

Letlapa la Papiso: Thepa ea Dielectric le Tahlehelo

Ts'ebetso e sebetsang ea ho khetha Substrate ea PCB ea Maqhubu a Phahameng

Mohato oa 1 - Hlalosa Maqhubu a Ts'ebetso le Bandwidth

Hlalosa karolo e phahameng ka ho fetisisa ea maqhubu a maqhubu a mats'oao a hau, ebang ke maqhubu a mantlha a li-circuits tsa RF kapa maqhubu a phahameng ka ho fetesisa a meralo ea dijithale. Oscillator ea lehae ea 10 GHz e hloka tlhahlobo ea substrate ho 10 GHz, ha lets'oao la 10 Gbps NRZ le hloka sebopeho sa thepa ka har'a harmonic ea bohlano haufi le 25 GHz. Tlhaloso ena ea maqhubu hang-hang e felisa lisebelisoa tse sa lokelang.

Mohato oa 2 - Hlahloba Tahlehelo ea Lipontšo le Botsitso ba Dielectric

Theha lichelete tsa tahlehelo ea ho kenya ka ho fana ka phokotso e amohelehang ka har'a tlhahlobo ea tekanyetso ea khokahano ea hau. Lisebelisoa tsa substrate tsa PCB tse phahameng tse nang le Df ka tlase ho 0.002 lia hlokahala ha tahlehelo ea dielectric kaofela e tlameha ho lula ka tlase ho 0.5 dB ka mose ho trace ea 10-inch ho 28 GHz. Likopo tse batlang betere ho feta -20 dB tahlehelo ea ho khutla li hloka li-substrates tse nang le botsitso ba Dk ka har'a ± 2% ho pholletsa le mocheso le maqhubu.

Mohato oa 3 - Nahana ka Taolo ea Thermal le Ho sebetsana le Matla

Li-amplifiers tsa motlakase tse senyang li-watts tse fetang 5 ka sekwere-inch li hloka lisebelisoa tse phahameng tsa maqhubu a PCB tse nang le mocheso o fetang 1 W/mK kapa meaho e tšehelitsoeng ka tšepe. Bala ho nyoloha ha mocheso oa matekoane ho netefatsa hore Tg margins e amohela maemo a mabe ka ho fetesisa a ts'ebetso. Meralo e teteaneng ea dijithale e ka hlahisa mocheso o lekaneng oo maikutlo a mocheso a fetang metrics ea ts'ebetso ea motlakase.

Mohato oa 4 - Lekola Matla a Tlhahiso le Litšenyehelo

Lintlha tsa tlhahiso bakeng sa khetho e phahameng ea maqhubu a PCB:

• Tšebelisano-'moho - PTFE e hloka ho cheka ka mokhoa o khethehileng le ho tsamaisa litsela ho bapisoa le ts'ebetso e tloaelehileng ea RO4000
• Ho fumaneha ha mofani oa thepa - Li-substrates tsa Premium li thibela likhetho tsa moetsi le ho eketsa nako ea ho etella pele
• Ho rarahana ha moralo - Li-stackups tse ngata le mamello e tiileng li hloka balekane ba nang le boiphihlelo ba tlhahiso
• Bokhoni ba tšobotsi - Bophahamo bo fokolang ba ho latella, ka likarohano tsa likarolo, le lipalo tsa mekhahlelo li fapana ho ea ka mofuta oa thepa

Maemo a Mohlala: Millimeter-Wave vs High-Speed ​​Digital

Antenna ea 28 GHz phased array e batla PTFE e tletseng ceramic e nang le Dk 3.0 le Df ka tlase ho 0.0015 ho fokotsa tahlehelo ea ho kenya marang-rang, moo ntlafatso e 'ngoe le e 'ngoe ea 0.1 dB e ntlafatsang mefuta e mengata ka ho toba. Sefofane sa morao sa 56 Gbps PAM-4 se mamella tahlehelo e phahameng ho pota 0.004, se etsa hore Rogers RO4350B kapa Megtron 7 e sebetse likhethong tse phahameng tsa PCB tse lekanyang ts'ebetso ea motlakase le multilayer manufacturability.

Mehopolo ea Moralo le Tlhahiso bakeng sa Li-substrates tsa High Frequency PCB

Taolo ea Impedans le Ntlafatso ea Stack-up

Ho fihlella mamello ea impedance ea ±10% ho hloka taolo e nepahetseng ea botenya ba dielectric, boima ba koporo, le jiometri ea trace. Lisebelisoa tsa substrate tsa PCB tse nang le litlhaloso tse thata tsa Dk li nolofalletsa ho bala impedance e ka boleloang esale pele, empa boleng ba 'nete bo itšetlehile ka ho lekana ha stackup, phallo ea prepreg nakong ea lamination, le ho tšoana ha plating ea koporo. Sebelisa lipontšo tse fapaneng bakeng sa litsela tsa bohlokoa 'me u boloke botenya ba lera la dielectric bo tsitsitseng ka hare ho ±10%. Bakeng sa kaho ea RF ea RO4835T e tšesaane , ho sebetsana, lamination le botenya ba dielectric bo felileng li lokela ho hlahlojoa hammoho pele sebopeho sa lera le nang le likarolo tse ngata se amoheloa.

Qetello ea Bokaholimo le Khetho ea Foil ea Koporo

Khauta e qoelisoang ea nickel e se nang motlakase e hlahisa keketseho e nyane ea tahlehelo ea ho kenya empa e fana ka bophelo bo botle ba lishelefo le khokahano ea terata. Ho qoelisoa ha silevera le organic solderability li qeta ho fokotsa tahlehelo e eketsehileng ha ho ntse ho hloka ho tšoaroa ka hloko. Hlalosa foil e tlositsoeng ka morao kapa koporo ea boemo bo tlase haholo bakeng sa maqhubu a ka holimo ho 10 GHz, moo ho se be teng ha electrodeposited ho hlahisa tahlehelo e eketsehileng ea 20-40%.

Ka Moralo le Tsamaiso ea Phetoho

Likoti tse kentsoeng ka har'a likoti li etsa hore ho se ke ha hlola ho e-ba teng ho tloha ho capacitive pad loading le inductive barrel effects. Fokotsa litšusumetso ka ho phunya mokokotlo ho tlosa li-stubs tse sa sebelisoeng, kapa sebelisa lisebelisoa tse sa boneng kapa tse patiloeng ho tlosa li-stubs ka ho feletseng. Sebaka se pota-potileng terata se arohaneng ka tlase ho bolelele ba mashome a mabeli ho thibela li-resonances tsa parallel-plate ho li-stackups tsa PCB tsa maqhubu a phahameng.

Mekhoa ea ho lekanya le ho netefatsa

Mekhoa ea bohlokoa ea netefatso bakeng sa ts'ebetso e phahameng ea maqhubu a PCB:

• Tlhahlobo ea S-parameter - Litekanyo tsa marang-rang tsa Vector li netefatsa tahlehelo ea ho kenya, tahlehelo ea ho khutla, le moeli oa mohato
• Nako-domain reflectometry - E tsebahatsa li-impedance discontinuities libakeng tse itseng tsa 'mele
• Thermal cycling - Lipotoloho tse 500-1000 pakeng tsa -40 ° C le +125 ° C li netefatsa ho tšepahala ka ho beha leihlo khanyetso
• Sebopeho sa dielectric - Litekanyo tse arohaneng tsa resonator li tiisa Dk le Df ea liboto tse entsoeng

Ho Lekanya Tshebetso, Ditjeho, le Tlhahiso

Khoebisano lipakeng tsa Ts'ebetso ea Motlakase le Litšenyehelo tsa Ts'ebetso

Lisebelisoa tsa substrate tsa PCB tse tlase-tlase haholo li lokafatsa tefiso ea bona ea 3-5× ha tahlehelo ea ho kenya e beha meeli ea sistimi ka kotloloho, sekhahla sa data, kapa matla a matla. Bolelele bo bokhuts'oane bo ka tlase ho li-inch tse 2 le maqhubu a ka tlase ho 10 GHz hangata bo fihlella litlhaloso ka thepa ea mahareng e bitsang halofo e kaalo. Lekanya boleng ba tlhahiso ka ho bala tšusumetso ea boemo ba sistimi ho fapana le ho ntlafatsa litšenyehelo tsa likarolo ka thoko.

Phepelo le Lintlha tsa ho ba Teng

Lisebelisoa tse ikhethang tsa maqhubu a phahameng a PCB ka linako tse ling li tobana le mathata a kabo nakong ea tšitiso ea phepelo. Litlhaloso tsa lisebelisoa tse nang le mehloli e 'meli moo ts'ebetso ea motlakase e lumellang, e tšoanelehang ka bobeli Rogers le Taconic mekhoa e meng kapa Megtron le Isola khetho ho boloka phetoho ea tlhahiso. Mananeo a nako e telele a tlhahiso a rua molemo ka ho sebelisana le baphatlalatsi ba thepa ho boloka kabo ea bokhoni le ho buisana ka litheko tsa bongata.

Moralo o sebelisanang le Moetsi oa PCB

Kopanya balekane ba tlhahiso nakong ea khetho ea thepa le tlhaloso ea stackup ho e-na le ho tlatsa meralo ka thoko. Bahlahisi ba nang le boiphihlelo ba fana ka tataiso ea moralo bakeng sa tlhahiso mabapi le boholo bo fokolang ba likarolo, ka likarolo tsa likarolo, le mamello ea impedance e ka finyelloang ka thepa e itseng ea PCB substrate e phahameng. Kopa li-coupon tsa teko ea impedance le lisampole tsa tlhaloso ea thepa qalong ea prototyping ho netefatsa mehlala ea motlakase. Jara sehlopha sa laminate se khethiloeng le botenya ba dielectric ka khotheishene ea RF PCB e ikhethileng ea thepa e le hore theko e hlahlobe kaho e netefalitsoeng ke moralo oa hau.

Kakaretso le Quick Reference Guide

Frequency Range vs Recommended Material Table

Lintlha tsa Bohlokoa bakeng sa Baqapi

Khetho e atlehileng ea maqhubu a phahameng a PCB e etelletsa pele maemo a tsitsitseng a dielectric ho pholletsa le mocheso le maqhubu, e fokotsa ntho ea ho senya ho boloka botšepehi ba matšoao, le ho netefatsa hore thepa ea mocheso e tšehetsa ts'ebetso e tšepahalang. Bapisa bokhoni ba lisebelisoa le litlhoko tsa ts'ebetso ea tlhahiso qalong ea lipotoloho tsa moralo, ka ho hlokomela hore ts'ebetso e nepahetseng ea motlakase e hloka lihlahisoa tse ka fihlellehang. Netefatsa dikakanyo ka ho etsa mohlala le ho metha ho ena le ho itshetleha feela ka ketsiso.

Ho sebelisana le Moetsi oa Setsebi oa PCB

Khetho le ts'ebetso e rarahaneng ea substrate ea PCB e nang le maqhubu a phahameng e rua molemo haholo ho tsoa boqhetsekeng ba moetsi ba ho sebetsana le thepa, ntlafatso ea ts'ebetso, le netefatso ea liteko. Highleap Electronics e ikhethile ka ho etsa li-PCB tse nang le maqhubu a phahameng ho pholletsa le litsamaiso tsa Rogers, Taconic, le laminate tse tsoetseng pele, e fana ka likeletso tsa moralo, tlhahiso ea impedance e laoloang, le liteko tse felletseng tsa motlakase.

Sehlopha sa rona sa boenjiniere se sebelisana 'moho le baqapi ho ntlafatsa li-stackups, lisebelisoa tse tšoanelehang, le ho theha lits'ebetso tsa tlhahiso tse fanang ka sephetho se ts'oanang ho tsoa ho prototype ka bongata ba tlhahiso.