Nrog rau kev kho dua tshiab ntawm cov neeg siv khoom, nws maj mam txhim kho nyob rau hauv cov kev taw qhia ntawm kev txawj ntse, yog li qhov yuav tsum tau rau PCB pawg thawj coj saib impedance tau dhau los ua nruj dua, uas tseem txhawb kev loj hlob tsis tu ncua ntawm impedance tsim tshuab.
Dab tsi yog yam ntxwv impedance?
1. Qhov kev tiv thaiv tsim los ntawm kev sib hloov tam sim no hauv cov khoom muaj feem xyuam nrog cov capacitance thiab inductance. Thaum muaj hluav taws xob teeb liab waveform kis tau tus mob hauv tus neeg xyuas pib, qhov kev tiv thaiv nws tau txais yog hu ua impedance.
2. Resistance yog qhov kev tawm tsam uas tsim los ntawm cov khoom siv hluav taws xob ncaj qha, uas muaj feem xyuam rau qhov voltage, resistivity thiab tam sim no.
Kev siv cov yam ntxwv impedance
1. Cov khoom siv hluav taws xob muab los ntawm cov ntawv luam tawm siv rau kev sib kis ntawm cov teeb liab ceev ceev thiab cov khoom siv hluav taws xob siab yuav tsum yog qhov tsis muaj kev cuam tshuam tshwm sim thaum lub teeb liab kis tau tus mob, cov teeb liab tseem nyob twj ywm, qhov kev sib kis tau raug txo, thiab cov txiaj ntsig zoo sib xws. tuaj yeem ua tiav. Ua kom tiav, txhim khu kev qha, raug, tsis muaj kev txhawj xeeb, tsis muaj suab nrov kis tau tus mob.
2. Qhov loj ntawm impedance tsis tuaj yeem nkag siab yooj yim. Qhov loj dua qhov zoo lossis qhov me dua qhov zoo, qhov tseem ceeb yog qhov sib txuam.
Tswj tsis tau rau tus yam ntxwv impedance
Lub dielectric qhov tsis tu ncua ntawm daim ntawv, lub thickness ntawm dielectric txheej, kab dav, tooj liab thickness, thiab lub thickness ntawm solder daim npog qhov ncauj.
Kev cuam tshuam thiab kev tswj ntawm cov npog ntsej muag
1. Lub thickness ntawm lub qhov ncauj qhov ntswg muaj kev cuam tshuam me ntsis ntawm impedance. Thaum lub thickness ntawm lub npog ntsej muag nce los ntawm 10um, tus nqi impedance hloov tsuas yog 1-2 ohms.
2. Hauv kev tsim, qhov sib txawv ntawm lub npog ntsej muag thiab lub npog ntsej muag uas tsis yog-cov npog ntsej muag yog qhov loj, ib qho kawg 2-3 ohms, thiab qhov sib txawv 8-10 ohms.
3. Nyob rau hauv kev tsim cov impedance board, lub thickness ntawm lub ntsej muag solder yog nquag tswj raws li qhov yuav tsum tau ua.
Kev ntsuas impedance
Txoj kev yooj yim yog TDR txoj kev (lub sij hawm sau reflectometry). Lub hauv paus ntsiab lus tseem ceeb yog tias lub ntsuas hluav taws xob tso tawm cov teeb liab mem tes, uas yog folded rov qab los ntawm qhov ntsuas ntawm lub rooj tsav xwm Circuit Court los ntsuas qhov kev hloov pauv ntawm tus yam ntxwv impedance tus nqi ntawm emission thiab foldback. Tom qab kev tshuaj xyuas computer, tus yam ntxwv impedance yog cov zis.
Kev daws teeb meem impedance
1. Rau qhov kev tswj tsis tau ntawm impedance, kev tswj yuav tsum tau ua tiav los ntawm kev sib nrig sib hloov hauv ntau lawm.
2. Tom qab lamination nyob rau hauv ntau lawm, lub rooj tsavxwm yog hlais thiab soj ntsuam. Yog tias qhov tuab ntawm qhov nruab nrab raug txo, txoj kab dav tuaj yeem raug txo kom tau raws li qhov yuav tsum tau ua; Yog tias nws tuab heev, cov tooj liab tuaj yeem ua kom tuab kom txo tau tus nqi impedance.
3. Nyob rau hauv qhov kev xeem, yog tias muaj qhov sib txawv loj ntawm qhov kev xav thiab qhov tseeb, qhov muaj peev xwm loj tshaj plaws yog tias muaj teeb meem nrog kev tsim qauv engineering thiab kev tsim ntawm cov ntawv xeem.
Post lub sij hawm: Mar-15-2022