Ukubekezelela I-PCB ye-RF: Ukukhiqiza Okunembayo Kokusebenza Okuphakeme Kakhulu

Isingeniso

Ekukhiqizweni kwe-RF PCB, ukunemba kobukhulu kunquma ngqo ukusebenza kwesekethe. Amasignali emvamisa ephezulu azwela kakhulu ekushintsheni kwejometri, kanye nokuphambuka kwezinga le-micron ngobubanzi bomkhondo, ukujiya kwe-dielectric, noma isisindo sethusi okuthinta ukufaniswa kwe-impedance kanye nobuqotho besignali. Kumafrikhwensi angaphezu kwe-3 GHz, imininingwane yokubekezelelana kwe-RF PCB engamukeleka kuma-circuits edijithali ingabangela ukulahlekelwa okukhulu kokufakwa, amaphutha esigaba, kanye nokuwohloka kokulahlekelwa kokubuya. Ekuhleleni kokulawula kobukhulu be-CLTE-XT , umdwebo wokwenziwa kufanele uhlukanise ukuziphatha kokunwetshwa kwezinto ekubekezeleni kobukhulu obudingekayo kusekethe esiqediwe.

Ukufinyelela ukulawula ukubekezelelana okuqinile kudinga ukuqonda ubudlelwano phakathi kobukhulu bomzimba nokusebenza kukagesi, bese kusetshenziswa izilawuli zenqubo eziqinile kukho konke ukwakhiwa. Le ndatshana ihlola ukuthi amasu okukhiqiza anembayo akugcina kanjani ukunemba kwe-dimensional kubalulekile ekusebenzeni okuthembekile kwesekethe ye-RF.

Iqhaza Lokubekezelelana kwe-RF PCB Ekusebenzeni Kwesekethe

Izinguquko zokukhiqiza zihumusha ngqo ekushintsheni kokusebenza kukagesi kumasekethe e-RF . Ushintsho lwama-micron ayi-10 kububanzi bokulandelela lushintsha i-impedance yesici, ludala ukubonakaliswa okwehlisa ukudluliswa kwamandla esignali. Lapho ubukhulu be-dielectric buhluka ngisho nangama-5%, i-impedance shift ephumelayo ingahambisa umugqa wokudlulisela ongu-50-ohm ngaphandle kwamafasitela afanayo amukelekayo.

Kumaza okushintshashintsha kwe-RF, ubude bamaza bufana nobukhulu besici se-PCB, okwenza amasekethe abe bucayi ekuqondeni kobukhulu. Ushintsho lwejubane lesigaba esingu-2% kusuka ekushintsheni kobukhulu be-dielectric lusho iphutha elikhulu lobude bukagesi ezakhiweni zamagagasi ekota. Ngaphezu kwe-10 GHz, ukuphambuka kokubekezelelana kwe-RF PCB okubangela imiphumela engemihle kumaza aphansi kukhiqiza ukuhlukahluka kokulahlekelwa kokufakwa okungaphezu kwe-0.5 dB nge-intshi ngayinye yobude bokulandelela. Ezakhiweni eziqinile ze-Dk ephezulu, imikhawulo yokwenziwa kwe-Rogers enokuvumela okuphezulu kufanele ifakwe kwisabelomali sokubekezelelana kukagesi kanye nobukhulu be-dielectric kanye nobe-conductor.

Ukubekezelela Okubalulekile Kwezokukhiqiza kuma-RF PCB

I-Dielectric Thickness Control

Ukujiya kongqimba lwe-Dielectric kulawula ngokuqondile i-impedance kanye nesivinini sokusabalalisa. Izinqubo ezijwayelekile ze-FR-4 zifinyelela ukubekezelela ukujiya okungu-±10%, kodwa izinhlelo ze-RF ngokuvamile zidinga u-±5% noma ukulawula okuqinile. Ukuhluka kwe-dielectric engu-100-micron kusendlalelo esingu-250-micron kushintsha i-microstrip impedance cishe ngama-ohm angu-4, okwanele ukubangela ukungafani okuphawulekayo.

Ama-laminate avame kakhulu avela emindenini ekhethekile ye-RF laminate anikeza ukuqina okungcono, ngamazinga aphezulu afinyelela ukubekezelelana okungu-±3% ngokuqukethwe kwe-resin okulawulwayo kanye nemijikelezo yokucindezela.

Ukuhlukahluka Kokuqina Kwethusi

Isisindo sethusi sithinta kokubili ukumelana nokulandela umkhondo kanye nobubanzi bokulandelela obusebenzayo ngemva kokuqoshwa. Ikhopha elijwayelekile elinguhhafu weounce liyahlukahluka ngo-±10%, okuhumushela kumehluko wogqinsi lwama-micron angu-3-4. Lokhu kuhluka kushintsha isilinganiso sobubanzi nobude bemigqa yokudlulisela, i-impedance eshintshayo kanye nokulahlekelwa kwe-conductor.

I-Electrodeposited copper inikeza ukulawula okuqinile kunethusi eligoqiwe, ngezinqubo zokucwenga zokucwenga ezifinyelela ukufana kogqinsi okungu-±5% okubalulekile ekugcineni ukubekezelela kwe-RF PCB okungaguquki kuyo yonke indawo yamaphaneli.

Ukunemba Kokubhaliswa Kwesendlalelo

I-Multilayer RF PCBs idinga ukuqondanisa okunembile phakathi kwezingqimba zesignali nezindiza eziphansi. Amaphutha okubhalisa ama-microns angu-75 noma ngaphezulu abangela ukungaqhubeki kwe-impedance lapho i-vias ishintsha phakathi kwezendlalelo. Ukukhiqiza okuthuthukile kusebenzisa ukuqondanisa kwe-optical fiducial kanye nokucindezela okunembayo kwe-lamination ukuze kuzuzwe ukubhaliswa okungu-±50-micron.

Imiklamo ebucayi icacisa ukuqondanisa okungu-±25-micron kumasekhethi we-millimeter-wave lapho ngoshintsho kufanele kugcinwe okubambekayo okulawulwayo kuyo yonke indlela eqondile.

Etching Precision

I-Photolithographic etching inquma i-trace geometry yokugcina. Ukufakwa okujwayelekile kokukhiphayo kukhiqiza ukuhluka okungu-±20% kobubanzi bomugqa ngenxa ye-engeli ye-undercut ne-sidewall. Ngokulandelela okungu-200-micron, lokhu kuhluka kwama-micron angu-40 kushintsha i-microstrip impedance ngo-3-5 ohms.

Ukufakwa kokujula okulawulwayo kunciphisa ukuhluka kuye ku-±10%, kuyilapho izinqubo zokwengeza ingxenye eguquliwe zithola ukubekezelela okuphelele okungu-±10-micron. Isinxephezelo se-etch esisetshenziswa ngesikhathi sokukhiqiza umsebenzi wobuciko kufanele sibhekane nogqinsi lwethusi kanye nokuma kwephaneli.

Nge-Drill Tolerance

Ubukhulu obudlulayo kanye nobokungaboni buthinta kokubili ukumelana kwe-DC kanye ne -RF impedance . Ukubhoboza ngomshini kufinyelela ukubekezelelana kobubanzi obungu-±75-micron, kuyilapho ukubhoboza nge-laser kunikeza ukunemba okungu-±10-micron kuma-microvia. Ukwehluka kobukhulu obudlulayo obuvela ku-electroplating kudala ukungaqhubeki kwe-impedance, ikakhulukazi ekuvinjelweni okulawulwayo ngezakhiwo.

I-Stack-up kanye ne-Dielectric Uniformity ye-RF PCB Tolerance

Ukungaguquguquki kwesitaki se-laminate kunquma ukuthi amabhodi akhiqiziwe ayahambisana yini nokuhlosiwe kwedizayini ye-impedance. Umjikelezo wabezindaba ulawula ukugeleza kwe-resin, ingcindezi yokuhlanganisa, namazinga okushisa erempu athinta ukushuba kokugcina kwe-dielectric. Ukwehluka kokuqukethwe kwe-prepreg resin okungu-±5% kungashintsha ukujiya okucindezelwe ngama-microns ayi-15-20.

Umthelela Wokukhetha Okubalulekile

Ukukhetha izinto ezibonakalayo kuthinta ngqo imininingwane yokubekezelelana kwe-RF PCB efinyelelekayo. Ama-laminate asekelwe ku-PTFE avela ochungechungeni lwe-laminate olusezingeni eliphansi anikeza ukubekezelelana kobukhulu obungu-±0.5 mil (±12.7 microns) kuma-grade ajwayelekile, kanti ama-grade anembile afinyelela ku-±0.3 mil. Ama-ceramics e-hydrocarbon afana ne-laminate esezingeni eliphansi le-hydrocarbon-ceramic ahlinzeka ngokuqina kobukhulu kulo lonke izinga lokushisa, agcina ukujiya kungaphakathi kuka-±2% kusukela ku--40°C kuya ku-+140°C. Ekwakhiweni kwebhodi le-TMM elizinzile lokushisa , ukubekezelelana kobukhulu kanye nokuziphatha kwezinto ezihlobene nokushisa kudinga ukuhlolwa okuhlukile ngoba uhlaka oluqondile lodwa alusunguli ukuzinza kwe-RF.

Ukubekezelelana okungaguquki kwe-dielectric kwalezi zinto zokwenziwa, ngokuvamile okungu-±2%, kuhlanganisa nokulawula ukushuba ukuze kugcinwe ukuvinjelwa ngaphakathi kokucaciswa.

Cindezela Ukuthuthukisa Inqubo

Ukuthuthukiswa kwenqubo yabezindaba kusebenzisa amazinga okushisa alawulwayo kanye nezikhathi zokuhlala ukuze kuzuzwe ukwelashwa okufanayo kwenhlaka. Amapuleti amathuluzi avula kaningi kanye namapuleti okucindezela afakwe ngomshini kahle asabalalisa ingcindezi ngokulinganayo kuyo yonke indawo yephaneli, anciphisa ukujiya kwama-gradient. Ukuqapha amapharamitha abezindaba ngokulawula inqubo yezibalo kukhomba ukukhukhuleka ngaphambi kokuba izingxenye ziphume ngaphandle kwezicaciso zokubekezelela.

Ukunemba Kwenqubo kanye Namasu Wokulinganisa

Ukuqinisekiswa kokukhiqiza kuqala ngokuhlolwa kwezinto ezingenayo kusetshenziswa ama-micrometer alinganisiwe namasistimu okulinganisa okubona. Ukuskena kwe-laser kulinganisa ubukhulu be-foil yethusi ezindaweni eziningi ukuze kutholwe ukufana kwesisekelo. Ukuhlaziywa kwezingxenye ezihlukene zamasampuli e-laminate kuqinisekisa ukushuba kwe-dielectric kanye nesilinganiso se-resin-to-glass ngaphambi kokuba ukukhiqizwa kuqale.

Izindlela Zokuqapha Ezingaphakathi Kwenqubo

Ukuqapha okungaphakathi kwenqubo kusebenzisa amakhuphoni okuhlola i-impedance abekwe emaphethelweni ephaneli. I-time-domain reflectometry ikala i-impedance eqanjiwe ngokumelene nokuhlosiwe kwedizayini, ngemiphumela ebuyiselwe ukuze kulungiswe isinxephezelo se-etch kanye nemingcele yokucindezela. Amasistimu okuhlola okuzenzakalelayo aqinisekisa ububanzi bokulandelela ezindaweni eziningi, ukuthola inqubo ukukhukhuleka ngaphambi kokuthi wonke amaphaneli aphume ngaphandle kwezicaciso zokubekezelela kwe-RF PCB.

Ukulawulwa kwenqubo yezibalo

Ukulawulwa kwenqubo yezibalo kusungula izinkomba zekhono lamapharamitha abalulekile. Amandla okucubungula (Cp) ngaphezulu kuka-1.33 abonisa ukuthi ukuhlukahluka kwenqubo yemvelo kufanelana kahle nemikhawulo ebekiwe, kuyilapho i-Cpk ilandisa ngokubeka phakathi kwenqubo. Ukulandelela lawa mamethrikhi wogqinsi lwe-dielectric, isisindo sethusi, nokunemba kokubhaliswa kunikeza isexwayiso sangaphambi kwesikhathi sokucekelwa phansi kwemishini.

Ukuzuza Ukunemba Ekwenziweni Kwe-RF PCB

Ukulawulwa kwe-precision lamination kuqala ngokulungisa izinto ezibonakalayo. Amashidi e-Prepreg agcinwa endaweni elawulwayo yomswakamo futhi alethwe ekulinganeni okushisayo ngaphambi kokucindezela ukuze kuqinisekiswe ukuziphatha kokugeleza kwe-resin okungaguquki. Amaphrofayili omjikelezo wabezindaba asebenzisa amazinga okushisa ahamba kancane kanye nezikhathi zokuhlala ezinde zamalayini e-RF uma kuqhathaniswa ne-FR-4, okuvumela ukuhlanganiswa okufanayo ngaphandle kwezindawo ezibulawa inhlaka.

Ukulawulwa Kwenqubo Okuzenzakalelayo

Izindlela zokukhiqiza ezinembayo eziyinhloko zihlanganisa:

• I-algorithms yesinxephezelo se-etch ezenzakalelayo - Lungisa ububanzi bokulandelela ngokusekelwe kugqinsi lwethusi kanye nendawo yephaneli ukuze ulondoloze ubukhulu phakathi kwama-microns angu-±10 kulo lonke iphaneli.
• Amasistimu wokumba ama-laser - Nikeza ngokunemba kokuma kwama-microns angu-±10 ngokubekwa ngokulawula ukujula okugcina ungaboni ngobukhulu obungaphakathi kwama-microns angu-±15.
• Ukuqondanisa ungqimba lwe-X-ray - Qinisekisa ukubhaliswa ngaphambi kokukhishwa kokugcina, okuvumela ukulungiswa uma izikhundla zefiducial zibonisa ukungahambi kahle okudlula izimfuneko zokubekezelela i-RF PCB.
• Ukulawula i-Pulse Plating - Ikhiqiza ukufakwa kwekhopha okufana kakhulu kune-DC plating, igcina ukuhluka kogqinsi phakathi kwama-microns angu-±2 endaweni yonke yamaphaneli.

Ukubambisana kwedizayini nokukhiqiza kusungula ukucaciswa okungokoqobo kokubekezelelana, ngamafayela edizayini ahlanganisa izici zesinxephezelo ze-etch ezifaniswa nezinqubo ezithile zokukhiqiza.

Ukuqinisekiswa Kwekhwalithi Nokuhlolwa Kwe-RF PCB Tolerance

Ukuhlola kokugcina kuhlanganisa ukuhlolwa kukagesi nokuqinisekiswa kwe-dimensional ukuze kuqinisekiswe ukuhlangana kwamabhodi akhiqiziwe. Ukuhlolwa kwe-Flying probe kuqinisekisa ukuxhumana kwe-DC nezikhindi, kuyilapho ukulungiswa okuzinikele kokuhlolwa kwe-impedance kukala izici zomugqa wokudlulisela kusetshenziswa abahlaziyi benethiwekhi ye-vector. Ukuqhathanisa i-impedance elinganiselwe ngokumelene nokuhlosiwe kwedizayini kuwo wonke amakhuphoni okuhlola kuveza amandla enqubo nokufana.

Izindlela Zokuqinisekisa Ubukhulu

Imishini yokulinganisa enezixhumanisi ezintathu ihlinzeka ngokuqinisekiswa kwemishini kwezici ezibalulekile. Ukulinganisa kusetshenziswa izindawo, ukulandelela ububanzi, nobukhulu bephedi ezindaweni ezithile kudala idatha enobukhulu obuqinisekisa ukusebenza kahle kokulawula inqubo. Ukuhlaziywa kwezigaba ezihlukene kuhlola ngokulimaza amabhodi amasampula, kwembula ukujiya kwangempela kwe-dielectric, isisindo sethusi, nokubhaliswa kongqimba.

Ukubhalwa Kwemibhalo kanye Nokulandeleka

Amaphakheji okuhlolwa kwe-athikili yokuqala abhala ukuthobela kobukhulu ukuze kugunyazwe ikhasimende ngaphambi kokuqala kokukhiqiza. Lawa maphakheji afaka imiphumela yokuhlolwa kwe-impedance, izithombe ezihlukene, kanye nedatha yezibalo ebonisa amandla enqubo. Ukurekhoda le datha kudala ukulandeleka okuxhumanisa indawo ngayinye yokukhiqiza ekusebenzeni okulinganiselwe kuyilapho kuqinisekisa ukuthobelana nezimfuneko ze-IPC-6018 zamabhodi aphrintiwe e-microwave.

Isiphetho

Ukunemba kokukhiqiza kunquma ukuthi amasekhethi e-RF ayafeza yini ukusebenza kwawo okuklanyiwe. Ukulawula ukushuba kwe-dielectric, isisindo sethusi, ukunemba kokubhaliswa, nokunemba kwe-etch ngaphakathi kwezicaciso zokubekezelela ze-RF PCB eziqinile kuqinisekisa ukuthi i-impedance, ukulahleka kokufakwayo, nezici zesigaba kufana nokuqagela kokulingisa. Njengoba amaza okusebenza akhula, amawindi okubekezelela okwamukelekayo ayancipha, adinga umzamo ohlangene phakathi kwamaqembu aklamayo nawenza.

I-Highleap Electronics iletha ukukhiqizwa kwe-RF PCB ngokunemba ngokusebenzisa:

• Ukulawulwa kwe-lamination okuthuthukisiwe - Igcina ukushuba kwe-dielectric ngaphakathi ± 3% ukuze kuvikelwe okungaguquki kuzo zonke izindawo zokukhiqiza.
• Ukuqapha inqubo yezibalo - Ukulandelela ngesikhathi sangempela kwamapharamitha abalulekile kuqinisekisa ukunemba kobukhulu ngaphambi kokuhlolwa kokugcina.
• Amaphrothokholi okuhlola aphelele - Ukuqinisekiswa kwe-Impedans, ukuhlaziywa kwezigaba ezihlukene, nokuhlolwa kwe-athikili yokuqala kuqinisekisa ukuthobela ukubekezelelana.
• Ukuhambisana ne-IPC-6018 - Izinqubo zokukhiqiza zihlangabezana nezindinganiso zemboni zekhwalithi nokuthembeka kwebhodi eliphrintiwe nge-microwave.

Xhumana ne-Highleap Electronics ukuze uxoxe ngokuthi amakhono ethu okukhiqiza ngokunemba angaqinisekisa kanjani ukuthi amasekethe akho e-RF ahlangabezana nezidingo zikagesi ngokulawula ukubekezelelana okuqinile.