I-prototype yebhodi ye-pcb enezinhlangothi ezimbili FR4 TG140 impedance elawulwa yi-PCB
Ukucaciswa komkhiqizo:
Izinto eziyisisekelo: | I-FR4 TG140 |
Ubukhulu be-PCB: | 1.6+/-10%mm |
Ukubalwa Kwesendlalelo: | 2L |
Ukuqina Kwethusi: | 1/1 oz |
Ukwelashwa kwendawo: | I-HASL-LF |
Imaski ye-solder: | Okuluhlaza okucwebezelayo |
Isikrini sikasilika: | Emhlophe |
Inqubo ekhethekile : | Okujwayelekile |
Isicelo
Amabhodi wesifunda ane-impedance elawulwayo anezici ezilandelayo:
1. Lawula ngokuqinile inqubo yokukhiqiza yebhodi lesifunda, okuhlanganisa ukukhethwa kwezinto ezibonakalayo, izintambo eziphrintiwe, isikhala sesendlalelo, njll., ukuqinisekisa ukuzinza kwe-impedance yesekethe;
2. Sebenzisa amathuluzi athile omklamo we-PCB ukuze uqinisekise ukuthi i-impedance ihlangabezana nezidingo zokuklama;
3. Kuyo yonke i-PCB layout kanye nomzila, sebenzisa indlela emfushane futhi unciphise ukugoba ukuze uqinisekise ukuzinza kwe-impedance;
4. Nciphisa i-crossover phakathi komugqa wesignali kanye nolayini wamandla kanye nomugqa waphansi, futhi unciphise i-crosstalk kanye nokuphazanyiswa komugqa wesignali;
5. Sebenzisa ubuchwepheshe be-impedance obufanayo emugqeni wokudlulisa isignali wesivinini esiphezulu ukuze uqinisekise ukuhlanzeka nokuzinza kwesignali;
6. Sebenzisa ubuchwepheshe bokuxhuma i-interlayer ukunciphisa umsindo ohlangene kanye nemisebe ye-electromagnetic;
7. Ngokwezidingo ezihlukene ze-impedance, khetha ukujiya kongqimba olufanele, ububanzi bomugqa, isikhala somugqa kanye ne-dielectric constant;
8. Sebenzisa ithuluzi elithile lokuhlola ukwenza ukuhlolwa kwe-impedance ebhodini lesifunda ukuze uqinisekise ukuthi imingcele ye-impedance ihlangabezana nezidingo zokuklama.
Kungani ukulawula okujwayelekile kwe-impedance kungaba ukuchezuka okungu-10% kuphela?
Abangane abaningi bathemba ngempela ukuthi i-impedance ingalawulwa ibe ngu-5%, futhi ngike ngezwa nangemfuneko ye-impedance engu-2.5%. Eqinisweni, inqubo yokulawula i-impedance ingu-10% ukuphambuka, okuqinile kancane, kungafinyelela ku-8%, kunezizathu eziningi:
1, ukuchezuka kwento yepuleti ngokwayo
2. Ukuchezuka kwe-Etching phakathi nokucubungula kwe-PCB
3. Ukwenziwa kwezinga lokugeleza okubangelwa ukufakwa kwe-lamination ngesikhathi sokucutshungulwa kwe-PCB
4. Ngesivinini esiphezulu, i-roughage engaphezulu ye-copper foil, i-PP glass fiber effect, kanye nomphumela wokuhluka kwamafrikhwensi we-DF wemidiya kufanele iqonde ukuthintana.
Asetshenziswa kuphi amabhodi wesekethe anezidingo ze-impedance ngokuvamile asetshenziswa?
Amabhodi esekethe anezidingo ze-impedance avame ukusetshenziselwa ukudluliswa kwesignali yesivinini esikhulu, njengokudluliswa kwesignali yedijithali yesivinini esikhulu, ukudluliswa kwesignali yefrikhwensi yomsakazo kanye nokudluliswa kwesignali ye-millimeter wave. Lokhu kungenxa yokuthi i-impedance yebhodi lesifunda ihlobene nesivinini sokudlulisela kanye nokuzinza kwesignali. Uma idizayini ye-impedance ingenangqondo, izothinta ikhwalithi yokudlulisela yesignali futhi ibangele nokulahlekelwa kwesignali. Ngakho-ke, ezikhathini ezidinga izinga eliphezulu lokudlulisa isignali, ngokuvamile kuyadingeka ukusebenzisa amabhodi wesifunda anezidingo ze-impedance.
Imibuzo Evame Ukubuzwa
I-Impedance ikala ukuphikiswa kwesekethe kagesi lapho kusetshenziswa ukushintshana kwamanje kuwo. Kuyinhlanganisela ye-capacitance kanye nokungeniswa kwesekethe kagesi emazingeni aphezulu. I-impedance ilinganiswa ngo-Ohms, ngokufanayo nokumelana.
Izinto ezimbalwa ezithinta ukulawulwa kwe-impedance ngesikhathi sokuklanywa kwe-PCB zifaka ububanzi bokulandelela, ukushuba kwethusi, ukushuba kwe-dielectric kanye ne-dielectric constant.
1)I-Er ilingana ngokuphambene nevelu ye-impedance
2) Ubukhulu be-dielectric bulingana nevelu ye-impedance
3)Ububanzi bomugqa buqhathaniswa ngokuphambene nevelu ye-impedance
4)Ugqinsi lwethusi lulingana ngokuphambene nenani le-impedance
5)Isikhala semigqa silingana nenani le-impedance (umehluko we-impedance)
6) Ubukhulu bokumelana ne-solder buhambisana ngokuphambene nevelu ye-impedance
Kuzinhlelo zokusebenza zemvamisa ephezulu ezihambisana nokuphazamiseka kokulandelelwa kwe-PCB kubalulekile ekugcineni ubuqotho bedatha nokucaca kwesignali. Uma i-impedance ye-PCB trace exhumanisa izingxenye ezimbili ingafani nokuphazamiseka kwesici sezingxenye, kungase kwenyuswe izikhathi zokushintsha ngaphakathi kwedivayisi noma isekethe.
I-impedance ephelile, i-Differential impedance, i-Coplanar impedance kanye ne-Broadside Coupled Stripline