Cov pob me me, kub ntawm lub pob silicon, cov kev sib txuas uas tom qab ntawd yuav rov qab thiab txuas rau lub rooj tsav xwm hauv Circuit Court, yog electroplated los ntawm qhov sov, ua tib zoo sib npaug kub sulfite tov. Chemistry ntawm da dej no yog exquisitely rhiab heev. Ib qho atom tsis ncaj ncees ntawm cov hlau, npib tsib xee, lossis tooj liab dissolving los ntawm lub tshuab rhaub hlau yuav sib koom ua ke nrog cov kub, ua ib qho nyuaj, nkig intermetallic uas yuav ua rau lub pob hluav taws xob thiab cov khoom siv kho tshuab. Lub qhov cub tso rau hauv qhov muaj nuj nqis, da dej rhiab yuav tsum yog tshuaj tsis pom. PTFE yog qhov tsis pom qhov cua sov.
Kub Sulfite Plating txheej txheem rau wafer tsoo
Wafer bumping yog ib kauj ruam tseem ceeb hauv kev ntim khoom semiconductor siab heev. Tom qab cov kev sib txuas ua ke yog tsim los ntawm silicon wafer, cov khoom siv me me (feem ntau yog kub, solder, lossis tooj liab) yog tsim rau ntawm cov khoom nkag / tso tawm. Cov pob no tso cai rau cov nti rov qab thiab txuas ncaj qha mus rau lub substrate lossis Circuit Board - cov txheej txheem hu ua flip-chip ntim.
Rau kub kub, lub da dej electroplating feem ntau yog akub sulfitedaws. Tsis zoo li cov laus, cyanide-based kub da dej, kub sulfite yog non-cyanide, ua haujlwm nyob ze-nruab nrab rau me ntsis alkaline pH (feem ntau 8-10), thiab muab cov khoom zoo, ci kub. Lub da dej muaj:
Kub li sodium los yog potassium kub sulfite complex.
Proprietary stabilizers los tiv thaiv decomposition.
Brighteners thiab levelers kom ua tiav ib tug du, uniform pob nto.
Conductive ntsev (xws li, potassium sulfite los yog phosphate) los txhim kho kev faib tawm tam sim no.
Lub da dej yog tswj ntawm ib tug maj mam40-60 degree. Ntawm qhov kub no, tus nqi plating yog optimized, deposit stress yog minimized, thiab lub pob morphology tseem zoo thiab uniform. Tag nrho cov txheej txheem yog ua nyob rau hauv chav tsev huv si, feem ntau nyob rau hauv lub tank npog los tiv thaiv cov pa paug.
Yog vim li cas PTFE rhaub yog qhov kev lag luam Standard
Hauv ibPTFE rhaub kub sulfite wafer bumpingdaim ntawv thov, lub rhaub dej kub ua haujlwm rau tib lub hom phiaj, tsis muaj kev cuam tshuam: muab cov cua sov ruaj khov, tsis muaj kev qhia txog cov hlau tsis huv rau hauv da dej. Ib lub tshuab cua sov uas siv tau zoo (piv txwv li, titanium, stainless hlau, lossis txawm tias kub-plated hlau) yuav maj mam leach ions rau hauv cov tshuaj sulfite. Cov sulfite ligand yog ib tug me me complexing neeg sawv cev uas tuaj yeem tua ntau cov hlau, tshwj xeeb tshaj yog thaum kub siab. Txawm tias muaj pes tsawg tus hlau, npib tsib xee, tooj liab, lossis zinc (ib feem ntawm ib billion) tuaj yeem koom ua ke nrog kub thaum electroplating. Cov txawv teb chaws atoms tsim nyuaj, nkig intermetallic theem lossis hloov cov qauv ntawm cov pob kub kub, ua rau:
Nce kev tiv thaiv.
Txo shear zog.
Cov pob txha tawg thaum lub sij hawm thermosonic los yog thermocompression bonding.
Tsis zoo wetting ntawm lub substrate thaum sib dhos.
Lub PTFE-sheathed immersion rhaub tshem tawm qhov kev pheej hmoo tag nrho. Lub PTFE sheath yog kiag li inert rau me ntsis alkaline kub sulfite tov. Nws tsis hnov mob nrog da dej chemistry, tsis nqus cov khoom, thiab tso tawm kiag li xoom hlau ions. Cov khoom siv PTFE nws tus kheej yog qib high-purity nkauj xwb, tsis muaj cov fillers lossis additives uas tuaj yeem ua rau muaj kab mob paug. Lub tshuab cua sov tuaj yeem ua rau muaj kev nyab xeeb rau hauv da dej rau lub hlis lossis xyoo yam tsis muaj kev puas tsuaj rau cov tshuaj purity.
Ntxiv qhov zoo: Tsis-Stick nto thiab kub rov qab
Qhov du, tsis-stick nto ntawm PTFE muab qhov txiaj ntsig thib ob tseem ceeb. Kub plating da dej muaj ib tug nyiam tso hlau mus rau tej yam conductive los yog catalytically active nto. Yog tias siv lub tshuab hluav taws xob hlau, kub yuav plam tawm mus rau nws lub plhaub, ua ib txheej ntxhib, tsis sib xws. Qhov no yuav:
Khib kub kub (tam sim no muaj nqis tshaj $60,000 toj ib kg).
Hloov cov cua sov qhov chaw emissivity thiab cov yam ntxwv ntawm cov cua sov hloov.
Tsim ib qhov chaw ntawm flaking hais tias yuav kis tau tus wafer.
Yuav tsum tau muab lub tshuab ua kom sov ib ntus, ib kauj ruam ntawm kev saib xyuas tus nqi thiab txaus ntshai.
Lub PTFE rhaub, ua hluav taws xob insulating thiab tsis-catalytic, tsis txhawb kub deposition. Lub sheath tseem huv si, ci, thiab tsis muaj hlau buildup. Txhua yam kub uas ua los nag (xws li, vim yog da dej decomposition) feem ntau yog cov hmoov zoo uas tuaj yeem sau rau ntawm cov lim cais, tsis ua raws li lub tshuab cua sov.
Lub PTFE lub rhaub yog cov tshuaj tsis muaj suab nrov, muaj qhov sov so hauv chav da dej uas cov nti cov kev sib txuas kub tau yug los, tsis ntxiv dab tsi tab sis cov cua sov uas xav tau rau kev tso nyiaj zoo meej, zoo ib yam.
Xyuas kom Uniform Bump Height hla lub Wafer
Rau kev vam meej flip-chip kev sib raug zoo, cov pob kub yuav tsum muaj qhov siab sib xws ntawm tag nrho cov wafer (feem ntau nyob rau hauv ± 1-2 μm rau 50 μm pob). Txhua qhov kev hloov pauv ntawm qhov kub thiab txias hla lub plating da dej ncaj qha txhais rau hauv kev hloov pauv hauv plating tus nqi, vim tias cov tshuaj tiv thaiv deposition yog thermally qhib. Ib qho chaw txias hauv da dej ua rau cov pob luv luv; qhov kub kub ua rau cov pob txha siab dua. Thaum lub wafer tom qab sib dhos thiab sib koom ua ke, qhov tsis sib xws ntawm lub pob qhov siab ua rau qhib kev sib txuas (qhov chaw luv luv tsis sib cuag) los yog cov pob qij txha tawg (qhov chaw siab pob tau txais siab dhau).
Lub PTFE immersion rhaub yog tsim los muab cov cua sov sib xws, qis-watt-density. Ntau cov khoom cua sov tau muab faib raws qhov ntev ntawm PTFE sheath, los yog ntau lub tshuab cua sov yog arrayed nyob ib ncig ntawm lub plating tank. Lub chav da dej feem ntau yog circulated (los ntawm PTFE-lined twj tso kua mis los yog nitrogen bubbling) kom tshem tawm tej thermal gradients. Lub PTFE lub rhaub ua rau muaj qhov sib xws los ntawm kev tsis tsim cov chaw kub kub. Nws qhov kub thiab txias yog khaws cia qis (feem ntau yog 3-5℃saum lub da dej kub), thiab PTFE sheath kis cov cua sov sib npaug. Qhov tshwm sim yog ± 1℃qhov kub thiab txias tsis sib xws thoob plaws lub plating tank, ua kom muaj qhov sib npaug ntawm qhov siab ntawm qhov tuag mus rau qhov tuag.
Purity Note: Chav huv huv thiab dej zoo yuav tsum tau muaj
Cov kub sulfite plating tov siv rau wafer bumping tsis yog ib tug raug kev lag luam da dej. Nws yuav tsum ua tau raws li cov qauv purity semiconductor. Yog li ntawd, tag nrho cov cua sov thiab cov dej tuav yuav tsum tau tsim rau kev ua haujlwm ultraclean:
Lub tank npog:Lub plating tank yog haum nrog lub hau kaw ntom nti (feem ntau yog ua los ntawm polypropylene lossis PVDF) los tiv thaiv cov khoom hauv huab cua, plua plav, thiab cov organic tebchaw tsis tuaj yeem nkag mus rau hauv da dej. Lub PTFE rhaub yog mounted los ntawm ib tug kaw flange nyob rau hauv lub hau los yog sab phab ntsa.
High-purity DI dej: The bath is made up with semiconductor‑grade deionized (DI) water, typically with resistivity >18.2 MΩ·cm thiab tag nrho cov organic carbon (TOC)<1 ppb. Any contamination in the water would be concentrated during bath operation.
PTFE rhaub ua ntej ntxuav:Ua ntej kev teeb tsa, PTFE lub rhaub yog ntxuav kom huv thiab passivated. Kev tu ib ntus feem ntau suav nrog:
Degreasing nrog ib tug me me, tsis muaj residue detergent.
Yaug nrog DI dej.
Soaking nyob rau hauv ib tug dilute nitric los yog sulfamic acid tov (kom tshem tawm tej nto hlau kab los ntawm cov txheej txheem tsim).
Thaum kawg yaug nrog DI dej thiab ziab hauv qhov chaw huv.
Tsis muaj silicone lossis hydrocarbon tso tawm:Lub PTFE lub rhaub yuav tsum tau ntawv pov thawj tias tsis muaj cov tshuaj tua kab mob, cov yas yas, lossis lwm yam khoom siv ntxiv uas tuaj yeem ua rau cov kub tso nyiaj los yog ua raws li cov neeg ua haujlwm theem.
Kev Ua Haujlwm Ua Haujlwm rau Kev Ua Si Ntev Ntev
Txhawm rau kom ua tiav lub neej ntawm cov kub sulfite da dej thiab PTFE rhaub, cov kev coj ua hauv qab no tau pom zoo:
Tank idle cua sov:Thaum cov kab plating tsis ua haujlwm (piv txwv li, thaum hmo ntuj lossis hnub so), lub da dej kub yuav raug txo kom sov hauv chav tsev kom qeeb degradation ntawm cov organic additives. Lub PTFE rhaub yog muab tua. Ib qho tshwj xeeb, qis-wattage PTFE stand-by heater tuaj yeem siv los ua kom lub da dej kom siab tshaj qhov dej nag ntawm cov ntsev (feem ntau yog 30 degree), tab sis qhov no feem ntau zam kom txuag tau lub zog.
Lim:Lub da dej tsis tu ncua lim los ntawm 0.2 μm lossis 0.1 μm polypropylene lossis PTFE lim kom tshem tawm cov khoom (xws li cov kub precipitates). Lub PTFE lub rhaub yuav tsum tau muab tso rau kom tsis txhob muaj kev cuam tshuam ncaj qha ntawm cov lim dej rov qab, uas tuaj yeem ua rau muaj kev cuam tshuam hauv zos lossis kev co.
Periodic da dej tsom xam:Cov kub concentration, pH, thiab qib ntxiv yog ntsuas txhua hnub. Kev poob tam sim ntawd hauv plating kev ua tau zoo qee zaum tuaj yeem taug qab mus rau lub rhaub tsis ua haujlwm (piv txwv li, lub plhaub tawg ua rau cov kab hlau nkag mus). Nyob rau hauv tas li ntawd, lub da dej cuam tshuam yuav tsum tau muab pov tseg thiab hloov.
Kev tshuaj xyuas lub rhaub:Thaum lub sij hawm tu da dej (xws li, txhua hli), lub PTFE lub rhaub yog qhov pom kev soj ntsuam cov kab nrib pleb, discoloration, los yog kub buildup (tsis muaj leej twg yuav tsum muaj). Kev ntsuas megger (kev tiv thaiv kev tiv thaiv) yog ua kom ntseeg tau tias tsis muaj noo noo nkag mus rau hauv cov ntaub.
Xaus: Tiv thaiv Microchip Cov Kev Sib Txuas Tseem Ceeb
PTFE immersion rhaub yog qhov tseem ceeb, tsis muaj kab mob, thiab txhim khu kev qha tshav kub rau cov txheej txheem kub sulfite wafer bumping. Nws tiv thaiv qhov zoo ntawm microchip cov kev sib txuas tseem ceeb- cov pob kub me me uas nqa cov teeb liab thiab lub zog ntawm lub nti mus rau lub ntiaj teb sab nraud. Yog tsis muaj chemically inert, hlau-dawb cua sov tov, da dej yuav degrade, pob uniformity yuav raug kev txom nyem, thiab sib dhos yields yuav vau. Kev ua haujlwm ntawm lub tshuab hluav taws xob supercomputer, smartphone, lossis lub tsheb tsis muaj zog yog tiv thaiv los ntawm atomic purity ntawm ib qho yooj yim, yas rhaub. Nyob rau hauv ib puag ncig huv si ntawm semiconductor ntim, PTFE lub rhaub tsis yog ib qho khoom siv xwb; nws yog ib tug purity tus neeg zov, ib tug yield enabler, thiab ib tug ntsiag to tus khub nyob rau hauv lub creation ntawm lub ntiaj teb no lub siab tshaj plaws electronics.
