BGA Reflow Tshuab

Tsis siv neeg BGA rework tshuab DH-A2 rau ntau yam chips kho

1. C4 (Controlled Collapse Chip Connection Controlled Collapse Chip Connection)

C4 yog ib daim ntawv zoo ib yam li ultrafine pitch BGA (saib daim duab 1). Lub suab dav dav ntawm lub pob solder txuas nrog silicon wafer yog 0.203-0.254mm, txoj kab uas hla ntawm lub pob solder yog 0.102-0.127mm, thiab Lub pob solder muaj pes tsawg leeg yog 97Pb / 3Sn. Cov pob no tuaj yeem ua tiav lossis ib nrab faib rau ntawm silicon wafer. Txij li cov ceramics tuaj yeem tiv taus qhov kub thiab txias dua, ceramics yog siv los ua substrates rau C4 kev sib txuas. Feem ntau, Au lossis Sn-plated kev sib txuas pads tau muab faib ua ntej rau ntawm qhov chaw ntawm cov ceramics, thiab tom qab ntawd kev sib txuas ntawm cov ntawv ci hauv daim ntawv C4 tau ua. Kev sib txuas C4 tsis tuaj yeem siv, thiab cov khoom siv sib dhos thiab cov txheej txheem uas twb muaj lawm tuaj yeem siv rau kev sib dhos vim tias qhov kub ntawm qhov kub ntawm 97Pb / 3Sn solder pob yog 320 degree, thiab tsis muaj lwm yam kev sib txuas ntawm solder hauv cov qauv sib txuas siv C4 kev sib txuas. . Nyob rau hauv C4 kev twb kev txuas, es tsis txhob solder paste to, luam ntawv high-temperature flux yog siv. Ua ntej, qhov kub-kub flux yog luam tawm ntawm cov ntaub qhwv ntawm lub substrate los yog cov pob solder ntawm silicon wafer, thiab tom qab ntawd cov khoom siv rau ntawm silicon wafer thiab cov ntaub ntawv sib txuas ntawm lub substrate yog qhov sib npaug, thiab txaus adhesion yog muab los ntawm lub flux los tuav tus txheeb ze txoj hauj lwm kom txog thaum lub reflow soldering tiav. Lub reflow kub siv rau kev sib txuas C4 yog 360 degree. Ntawm qhov ntsuas kub no, cov khoom siv tau yaj thiab cov silicon wafer nyob rau hauv lub xeev "tshem tawm". Vim yog qhov nro ntawm lub solder, lub silicon wafer yuav tau kho qhov txheeb ze ntawm lub pob solder thiab lub ncoo, thiab thaum kawg lub solder yuav vau. mus rau ib qhov siab los tsim ib qho kev sib txuas lus. Txoj kev sib txuas C4 feem ntau yog siv hauv CBGA thiab CCGA pob. Tsis tas li ntawd, qee cov tuam txhab lag luam kuj tseem siv cov thev naus laus zis no hauv ceramic multi-chip module (MCM-C) daim ntawv thov. Tus naj npawb ntawm I/Os siv C4 kev sib txuas hnub no yog tsawg dua 1500, thiab qee lub tuam txhab xav tias yuav tsim I/Os ntau tshaj 3000. Qhov zoo ntawm C4 kev sib txuas yog: (1) Nws muaj cov khoom siv hluav taws xob zoo thiab thermal. (2) Nyob rau hauv cov ntaub ntawv ntawm nruab nrab pob pitch, lub I / O suav yuav ua tau siab heev. (3) Tsis txwv los ntawm lub ncoo loj. (4) Nws tuaj yeem tsim nyog rau kev tsim khoom loj. (5) Qhov loj thiab qhov hnyav tuaj yeem txo qis heev. Tsis tas li ntawd, qhov kev sib txuas C4 tsuas muaj ib qho kev sib txuas sib txuas ntawm cov silicon wafer thiab cov substrate, uas tuaj yeem muab qhov luv tshaj plaws thiab tsawg tshaj plaws cuam tshuam cov teeb liab kis tau tus mob, thiab txo tus naj npawb ntawm cov interfaces ua rau cov qauv yooj yim thiab txhim khu kev qha. Tseem muaj ntau yam kev sib tw hauv kev sib txuas C4, thiab nws tseem nyuaj rau kev siv nws rau cov khoom siv hluav taws xob. Kev sib txuas C4 tsuas yog siv tau rau cov khoom siv hluav taws xob, thiab lawv yuav siv dav hauv cov khoom lag luam siab, siab-I / O- suav, xws li CBGA, CCGA, thiab MCM-C.

Daim duab 1

2 DCA (Direct Chip Attach)

Zoo ib yam li C4, DCA yog ib qho kev sib txuas zoo heev (saib daim duab 2). Lub silicon wafer ntawm DCA thiab silicon wafer nyob rau hauv lub C4 kev twb kev txuas muaj ib tug zoo qauv. Qhov sib txawv ntawm ob yog nyob rau hauv kev xaiv ntawm substrate. Lub substrate siv hauv DCA yog cov khoom siv luam ntawv. Lub pob solder muaj pes tsawg leeg ntawm DCA yog 97Pb / 3Sn, thiab cov solder ntawm qhov txuas txuas yog eutectic solder (37Pb / 63Sn). Rau DCA, txij li qhov sib nrug tsuas yog 0 nkaus xwb. sab saum toj ntawm cov ntaub ntawv sib txuas ua ntej sib dhos. Qhov ntim ntawm cov ntaub qhwv ntsej muag yog nruj heev, feem ntau yog solder ntau dua li lwm cov khoom siv ultra-nplua. Lub solder nrog lub thickness ntawm 0.051-0.102mm ntawm qhov txuas txuas yog feem ntau me ntsis dome-puab vim nws yog pre-plated. Nws yuav tsum tau leveled ua ntej lub thaj, txwv tsis pub nws yuav cuam tshuam qhov txhim khu kev qha kev sib raug zoo ntawm lub pob solder thiab lub ncoo.

Daim duab 2

Hom kev sib txuas no tuaj yeem ua tiav nrog cov khoom siv saum npoo av uas twb muaj lawm thiab cov txheej txheem. Ua ntej, cov flux yog dispensed mus rau silicon wafers los ntawm kev luam ntawv, ces cov wafers yog mounted thiab thaum kawg reflowed. Lub reflow kub siv nyob rau hauv DCA los ua ke yog hais txog 220 degree, uas yog qis dua lub melting point ntawm cov khoom solder tab sis siab tshaj qhov melting point ntawm eutectic solder ntawm cov ntaub ntawv sib txuas. Cov khoom siv ntawm cov khoom siv silicon ua raws li kev txhawb nqa nruj. Ib qho kev sib txuas sib txuas yog tsim los ntawm lub pob thiab lub ncoo. Rau cov solder sib koom ua ke nrog ob qhov sib txawv Pb / Sn compositions, qhov sib txawv ntawm ob lub solders tsis tau pom tseeb nyob rau hauv kev sib koom tes, tab sis ib qho kev hloov ntawm thaj tsam ntawm 97Pb / 3Sn rau 37Pb / 63Sn yog tsim. Vim qhov kev txhawb nqa nruj ntawm cov khoom siv, cov khoom siv hlau tsis "tso" hauv DCA lub rooj sib txoos, tab sis kuj muaj cov khoom kho tus kheej. DCA tau pib thov, tus naj npawb ntawm I/Os feem ntau yog qis dua 350, thiab qee lub tuam txhab npaj yuav tsim ntau tshaj 500 I/Os. Lub zog rau kev txhim kho thev naus laus zis no tsis yog qhov suav I / O ntau dua, tab sis feem ntau txo qhov loj, qhov hnyav thiab tus nqi. Cov yam ntxwv ntawm DCA zoo ib yam li C4. Txij li thaum DCA tuaj yeem siv cov cuab yeej siv saum npoo av uas twb muaj lawm kom paub txog kev sib txuas nrog PCB, muaj ntau daim ntawv thov uas tuaj yeem siv cov thev naus laus zis no, tshwj xeeb tshaj yog nyob rau hauv daim ntawv thov ntawm cov khoom siv hluav taws xob portable. Txawm li cas los xij, qhov zoo ntawm DCA thev naus laus zis tsis tuaj yeem hais ntau dhau. Tseem muaj ntau yam kev sib tw hauv kev tsim DCA thev naus laus zis. Tsis muaj ntau tus neeg sib sau ua ke siv cov thev naus laus zis no hauv kev tsim khoom tiag tiag, thiab lawv txhua tus tab tom sim txhim kho qib thev naus laus zis kom nthuav dav daim ntawv thov DCA. Txij li thaum DCA kev twb kev txuas hloov cov high-density-hais txog complexities rau lub PCB, nws ua rau kom qhov nyuaj ntawm PCB manufacturing. Tsis tas li ntawd, muaj ob peb lub tuam txhab tshwj xeeb hauv kev tsim cov silicon wafers nrog cov khoom siv. Tseem muaj ntau yam teeb meem tsim nyog yuav tsum tau ua tib zoo saib, thiab tsuas yog thaum cov teeb meem no daws tau tuaj yeem txhim kho DCA thev naus laus zis.

3. FCAA (Flip Chip Adhesive Attachment) Muaj ntau hom kev sib txuas FCAA, thiab nws tseem nyob rau theem pib ntawm kev txhim kho. Kev sib txuas ntawm silicon wafer thiab substrate tsis siv cov nplaum, tab sis kua nplaum. Hauv qab ntawm silicon nti hauv qhov kev sib txuas no tuaj yeem muaj cov khoom siv los yog cov khoom siv xws li cov pob qij txha. Adhesives siv nyob rau hauv FCAA muaj xws li isotropic thiab anisotropic hom, nyob ntawm seb cov kev twb kev txuas nyob rau hauv daim ntawv thov tiag tiag. Tsis tas li ntawd, kev xaiv ntawm substrates feem ntau suav nrog ceramics, cov ntaub ntawv luam tawm thiab cov khoom siv hluav taws xob hloov tau yooj yim. Cov thev naus laus zis no tseem tsis tau paub tab thiab yuav tsis tau piav qhia ntxiv ntawm no.