Qhov tseeb, lub impedance tswj niaj hnub yog 10% sib txawv. Ib qho kev nruj me ntsis tuaj yeem ua tiav 8%. Muaj ntau yam laj thawj:

1. Qhov sib txawv ntawm cov ntaub ntawv nws tus kheej

2. Etching sib txawv hauv PCB ua

3. Deviations xws li ntws tus nqi tshwm sim los ntawm lamination thaum lub sij hawm ua PCB

4. Thaum muaj kev kub ceev, qhov roughness ntawm qhov chaw ntawm cov ntawv ci tooj liab, cov iav fiber ntau ntawm PP, DF zaus hloov cov nyhuv ntawm qhov nruab nrab, thiab lwm yam.

Txhawm rau nkag siab impedance, koj yuav tsum nkag siab txog kev ua haujlwm. Hauv ob peb tsab xov xwm tom ntej no, cia peb saib qee qhov kev paub txog kev ua haujlwm. Thawj tus yuav saib lamination:

1. Lub hauv paus ntsiab lus ntawm PCB nias

Lub hom phiaj tseem ceeb ntawm lamination yog los ua ke PP nrog sib txawv hauv cov core boards thiab sab nrauv tooj liab foils los ntawm “kub thiab siab”, thiab siv cov ntawv ci tooj liab sab nrauv los ua lub hauv paus ntawm sab nraud. Thiab sib txawv PP muaj pes tsawg leeg nrog sib txawv puab phaj thiab nto tooj liab yuav nruab nrog txawv specifications thiab thickness ntawm Circuit Court boards. Cov txheej txheem nias yog cov txheej txheem tseem ceeb tshaj plaws hauv kev tsim khoom ntawm PCB multilayer boards, thiab nws yuav tsum ua kom tau raws li cov txheej txheem zoo ntawm PCB tom qab nias.

1. Thickness: Muab cov khoom siv hluav taws xob cuam tshuam, kev tswj hwm impedance, thiab kua nplaum txhaws ntawm cov txheej sab hauv.

2. Kev sib xyaw ua ke: Muab kev sib txuas nrog cov xim dub sab hauv (xim av) thiab cov ntawv ci tooj liab.

3. Dimensional stability: Qhov kev hloov pauv ntawm txhua txheej sab hauv yog zoo ib yam los xyuas kom meej qhov sib dhos ntawm lub qhov thiab cov nplhaib ntawm txhua txheej.

4. Board warping: Tswj lub tiaj tiaj ntawm lub rooj tsavxwm.

2. PCB nias txheej txheem

Cov xwm txheej uas yuav tsum tau ua raws li cov txheej txheem nias

A. Khoom siv:

Sab hauv core board ntawm tus neeg xyuas pib qauv yog ua

Tooj liab ntawv ci

Ua ntej

B. Cov txheej txheem txheej txheem:

siab kub

kev kub siab

3. Taw qhia rau PP ntawm cov khoom laminated

tus cwj pwm:

Properties ntawm prepreg

A. RC% (Cov ntsiab lus Resin): yog hais txog qhov hnyav feem pua ​​​​ntawm cov khoom siv cob hauv zaj duab xis tshwj tsis yog cov ntaub iav. Tus nqi ntawm RC% ncaj qha cuam tshuam rau cov resin lub peev xwm los sau qhov khoob ntawm cov xov hlau, thiab tib lub sijhawm txiav txim siab lub thickness ntawm dielectric txheej tom qab nias lub rooj tsavxwm.

B. RF% (Resin flow): yog hais txog qhov feem pua ​​ntawm cov resin ntws tawm ntawm lub rooj tsavxwm mus rau tag nrho qhov hnyav ntawm thawj prepreg tom qab nias lub rooj tsavxwm. RF% yog ib qho kev ntsuas qhia txog qhov fluidity ntawm cov resin, thiab nws kuj txiav txim siab lub thickness ntawm dielectric txheej tom qab nias lub phaj.

C. VC%. Tus nqi ntawm VC% ncaj qha cuam tshuam qhov zoo tom qab nias.

Function:

1. Raws li kev sib txuas nruab nrab ntawm cov txheej txheem sab hauv thiab sab nrauv.

2. Muab cov txheej txheej insulating tsim nyog. Zaj duab xis yog tsim los ntawm iav fiber ntau daim ntaub thiab cob. Lub thickness sib txawv ntawm tib lub iav fiber ntau daim ntaub zaj duab xis tom qab nias yog tsuas yog hloov kho los ntawm cov ntsiab lus sib txawv es tsis yog cov txheej txheem nias.

3. Impedance tswj. Ntawm qhov tseem ceeb ntawm plaub yam cuam tshuam, tus nqi Dk thiab lub thickness ntawm dielectric txheej yog txiav txim los ntawm cov yam ntxwv ntawm cov yeeb yaj kiab. Tus nqi Dk ntawm cov yeeb yaj kiab tsim tuaj yeem kwv yees los ntawm cov qauv hauv qab no.

Dk = 6.01-3.34RR: Resin ntsiab lus%

Yog li ntawd, tus nqi Dk siv thaum kwv yees qhov impedance tuaj yeem suav tau raws li qhov sib piv ntawm cov iav fiber ntau thiab cov resin hauv laminated zaj duab xis ua ke.

Qhov tseeb thickness ntawm PP tom qab filling yog xam raws li nram no:

Thickness tom qab PP nias

1. Thickness = theoretical thickness ntawm ib leeg PP-filling poob

2. Filling poob = (1-A nto puab txheej tooj liab ntawv residual tooj liab tus nqi) x puab txheej tooj liab ntawv ci thickness + (1-B nto puab txheej tooj liab ntawv nyiaj residual tooj liab tus nqi) x puab txheej tooj liab ntawv ci thickness / 3, puab txheej Residual tooj liab tus nqi = sab hauv thaiv cheeb tsam / tag nrho pawg thawj coj saib cheeb tsam

Qhov seem tooj liab tus nqi ntawm ob txheej sab hauv hauv daim duab saum toj no yog raws li hauv qab no:

Thov xyuam xim rau cov qauv saum toj no. Yog tias peb xam qhov poob ntawm cov txheej txheem thib ob, peb tsuas yog yuav tsum xam ib sab, tsis yog qhov seem tooj liab ntawm txheej txheej. raws li nram no:

Filling poob = (1- puab tooj liab ntawv residual tooj liab tus nqi) x puab tooj liab ntawv ci thickness

Compression qauv tsim

(1) Cov tub ntxhais nyias nyias nrog cov tuab loj dua yog nyiam (zoo dua qhov kev ruaj ntseg zoo)

(2) Tus nqi qis PP yog qhov nyiam (rau tib lub iav ntaub hom PP, cov ntsiab lus resin yeej tsis cuam tshuam rau tus nqi)

(3) Cov qauv symmetrical nyiam kom tsis txhob muaj PCB warpage tom qab cov khoom tiav. Cov duab hauv qab no yog cov qauv tsis muaj nplai thiab tsis pom zoo.

(4) Lub thickness ntawm lub dielectric txheej 》 lub thickness ntawm lub puab tooj liab ntawv × 2

(5) Nws yog txwv tsis pub siv PP nrog cov ntsiab lus qis hauv ib daim ntawv ntawm 1-2 txheej thiab n-1 / n txheej, xws li 7628 × 1 (n yog tus lej ntawm cov txheej)

(6) Rau 3 los yog ntau tshaj prepregs teem ua ke los yog lub thickness ntawm lub dielectric txheej yog ntau tshaj 25 mils, tshwj tsis yog rau lub sab nrauv thiab innermost txheej ntawm PP, nruab nrab PP yog hloov los ntawm lub teeb board.

(7) Thaum cov txheej thib ob thiab n-1 txheej yog 2oz hauv qab tooj liab thiab cov tuab ntawm 1-2 thiab n-1 / n txheej ntawm insulating txheej yog tsawg dua 14mil, nws yog txwv tsis pub siv ib leeg PP, thiab sab nraud. txheej yuav tsum tau siv siab resin ntsiab lus PP. Xws li 2116, 1080; yog tias qhov seem tooj liab tsawg dua 80%, sim kom tsis txhob siv ib qho 1080PP

(8) Cov txheej sab hauv ntawm tooj liab 1oz board, thaum 1-2 txheej thiab n-1 / n txheej siv 1 PP, PP yuav tsum siv cov ntsiab lus siab resin, tshwj tsis yog 7628 × 1

(9) Nws yog txwv tsis pub siv ib leeg PP rau cov laug cam nrog sab hauv tooj liab ≥ 3oz. Feem ntau, 7628 tsis siv. Ntau PPs nrog cov ntsiab lus siab resin yuav tsum tau siv, xws li 106, 1080, 2116…

(10) Rau cov laug cam uas tsis muaj tooj liab ntau dua 3 “× 3” lossis 1 “× 5”, PP feem ntau tsis siv los ua ib daim ntawv ntawm cov ntawv tseem ceeb.