Xaiv ib hom tshuaj txhuam hmoov hmoov tsis yog ib qho teeb meem ntawm kev xaiv cov hmoov zoo tshaj plaws. Cov khoom yuav tsum me me txaus rau qhov xav tau tshaj plaws stencil apertures, tab sis tag nrho cov muab tshuaj txhuam yuav tsum haum rau cov alloy, flux system, stencil thickness, cia tej yam kev mob, reflow txheej txheem thiab yuav tsum tau ntau lawm stability.
Teb ceev:siv tsib- txoj cai pob ua thawj lub vijtsam rau qhov nqaim ntawm lub kaum sab xis aperture. Rau ib lub voj voog aperture, siv qhov kev saib xyuas ntau dua - suav kev ntsuas vim tias thaj chaw siv tau nqaim deb ntawm qhov nruab nrab. Tom qab ntawd xam cov cheeb tsam piv thiab validate qhov tshwm sim nrog rov luam ntawv thiab solder paste tshuaj xyuas.
Cov kab ke no pab tshem tawm kom pom tseeb qhov tsis zoo ntawm cov hmoov nplej. Nws tsis hloov cov khoom siv cov ntaub ntawv cov ntaub ntawv, stencil tsim tshuaj xyuas los yog txheej txheem validation.
Vim li cas Powder Size Matters hauv Stencil Printing
Solder muab tshuaj txhuamua ke cov hmoov txhuas nrog cov flux- muaj tsheb. Thaum lub sij hawm luam ntawv, cov tshuaj yuav tsum yob nyob rau hauv pem hauv ntej ntawm lub squeegee, sau lub aperture thiab cais los ntawm cov phab ntsa stencil thaum tseem tshuav ntawm PCB ncoo.
Cov hmoov me me cuam tshuam txog pes tsawg cov khoom tuaj yeem tuav tau qhov qhib me me. Txawm li cas los xij, particle loj tsuas yog ib feem ntawm cov txheej txheem. Covua hauj lwm hauv paus ntsiab lus ntawm solder pastekuj nyob ntawm flux chemistry, rheology thiab cua sov tus cwj pwm.
Rau kev xaiv hmoov, khaws peb nqe lus sib cais:
- Solder paste hmoov lojyog lub ntsiab lus dav dav - loj.
- Hom hmoovyog ib qho kev faib tawm xws li Hom 3, Hom 4, Hom 5 lossis Hom 6.
- Upper particle -loj txwvyog tus nqi siv rau thawj geometric ntsuam xyuas xam.
Tsis txhob xav tias txhua yam khoom uas muaj tib hom kev xaiv muaj kev tswj hwm zoo ib yam. Siv tus neeg muag khoom qhov kev qhia tshwj xeeb rau kev suav zaum kawg.
Tsib -Pob thiab voj voog -Aperture Screening Rules yog dab tsi?
Ob txoj kev sib piv cov hmoov loj tshaj plaws nrog rau qhov qhib stencil tsawg tshaj plaws. Lawv teb ib lo lus nug thaum ntxov:
Puas yog cov khoom me me txaus rau qhov aperture geometry yam tsis muaj cov neeg siv khoom siv tau dhau los txwv?
Lawv tsis ncaj qha ntsuas qhov muab tshuaj tso tawm, hloov pauv kev ua haujlwm lossis qhov kawg solder-kev sib koom ua haujlwm zoo.
Tsib -Ball Txoj Cai rau Rectangular Apertures
Tsib - txoj cai pob yog feem ntau siv rau qhov nqaim tshaj plaws ntawm lub kaum sab xis.
Yam tsawg kawg nkaus aperture dav ≈ 5 × sab sauv particle-loj txwv
Rau qhov muab tshuaj txhuam nrog qhov loj me me ntawm 38 μm:
5 × 38 μm = 190 μm
Lub aperture duab plaub uas yog 200 μm dav yog li nqaim dhau qhov screen geometric.
Txoj cai feem ntau yog nyob rau sab sauv kawg ntawm kev tswj particle faib, tsis yog qhov nruab nrab particle txoj kab uas hla. IPC cov ntaub ntawv qhia txog kev sib tham txog tsib -particle kev sib raug zoo raws li kev qhia txog kev tsim vaj tsev es tsis yog txoj kev tsim nyog ua tiav.
Conservative Screen rau Circular Apertures
Ib puag ncig aperture tsim teeb meem ntim sib txawv. Tsib hais tuaj yeem haum thoob plaws hauv nruab nrab txoj kab uas hla, tab sis qhov dav muaj tsawg tsawg ntawm qhov nruab nrab. Ib qho muab tshuaj txhuam uas tsuas yog dhau ntawm tsib lub duab plaub- kev suav pob tuaj yeem ua rau cov neeg nyob ib puag ncig tsawg thoob plaws thaj chaw ncig.
Ib qho kev sib tham sib tham txog kev saib xyuas engineering yog:
Yam tsawg kawg nkaus aperture txoj kab uas hla ≈ 8 × sab sauv particle-loj txwv
Rau qhov loj me me ntawm 38 μm:
8 × 38 μm = 304 μm
A 275 μm lub voj voog qhib tsis tau raws li qhov kev saib xyuas tus nqi, txawm hais tias kwv yees li xya sab sauv - qhov loj me tuaj yeem hla nws txoj kab uas hla. Kev sib xyaw ua ke tseem tuaj yeem luam tawm raws li zoo - tswj cov xwm txheej, tab sis nws muaj cov duab geometric tsawg dua li muab tshuaj txhuam nrog cov khoom me me.
Lub voj voog no - kev suav aperture yuav tsum raug kho raws li kev tshuaj ntsuam xyuas, tsis yog raws li qhov yuav tsum tau ua ntawm IPC lossis txoj cai hla thoob ntiaj teb.
Common Solder Paste Powder Hom
Cov kab hauv qab no feem ntau siv rau kev sib piv engineering. Paub meej qhov tseeb particle tis, xeem txoj kev thiab specification nrog cov ntaub ntawv cov khoom tam sim no ua ntej yuav los yog pom zoo ib tug txheej txheem.
| Hom hmoov | Common Particle Range | Upper Size siv rau kev tshuaj ntsuam | Tsib -Ball Threshold | Yim -Particle Circular Threshold |
|---|---|---|---|---|
| Hom 3 | 25–45 μm | 45 μm | 225 μm | 360 μm |
| Hom 4 | 20–38 μm | 38 μm | 190 μm | 304 μm |
| Hom 5 | 15–25 μm | 25 μm | 125 μm | 200 μm |
| Hom 6 | 5–15 μm | 15 μm | 75 μm | 120 μm |
Cov txiaj ntsig no piav qhia vim li cas Hom 4 tuaj yeem luam tawm cov yam ntxwv uas nyuaj rau Hom 3, thiab yog vim li cas Hom 5 lossis Hom 6 yuav raug txiav txim siab rau qhov zoo dua. Lawv tsis tau txhais hais tias txhua lub rooj sib txoos yuav tsum txav mus rau qhov tsawg tshaj plaws muaj hmoov.
Raws li qhov loj me me zuj zus, cov khoom me me tuaj yeem tuav lub aperture me me thiab zoo -feature txhais yuav txhim kho. Nyob rau tib lub sij hawm, tag nrho cov particle deg cheeb tsam nce, yog li oxidation tswj, cia, flux formulation thiab reflow tus cwj pwm yuav ua tau ntau rhiab heev. Qhov davlub cev muaj zog ntawm solder pasteyog li ntawd yuav tsum tau tshuaj xyuas ua ke nrog hmoov Hom.
Ua Haujlwm Piv Txwv 1: A 0.20 mm Rectangular Aperture
Xav txog lub aperture rectangular nrog qhov dav yam tsawg kawg nkaus:
0.20 hli=200 μm
Hom 3 Screen
5 × 45 μm = 225 μm
Lub 200 μm aperture yog me dua li 225 μm kev tshuaj ntsuam tus nqi.
Kev tshuaj ntsuam xyuas: Type 3 does not pass the conventional five-ball screen.
Hom 4 Screen
5 × 38 μm = 190 μm
Lub 200 μm aperture yog me ntsis loj dua 190 μm.
Kev tshuaj ntsuam xyuas:Hom 4 hla, tab sis nrog txwv geometric margin.
Hom 5 Screen
5 × 25 μm = 125 μm
Hom 5 muab ntau qhov particle ntau dua -size margin.
Qhov ntawd tsis cia li ua rau Hom 5 cov khoom zoo dua. Thaum Hom 4 twb muab kev tso tawm ruaj khov, kev rov ua tau zoo thiab kev ua haujlwm tsim nyog, hloov mus rau cov hmoov zoo tuaj yeem ntxiv cov nqi lossis cov txheej txheem rhiab heev yam tsis muaj kev daws teeb meem.
Txoj cai yuav tsum tshem tawm cov kev xaiv tsis tsim nyog. Nws yuav tsum tsis txhob xaiv tag nrho paste los ntawm nws tus kheej.
Ua Haujlwm Piv txwv 2: A 0.275 mm Circular Aperture
Tam sim no xav txog ib ncig aperture nrog ib txoj kab uas hla ntawm:
0.275 hli=275 μm
Hom 3 Screen
8 × 45 μm = 360 μm
Lub aperture yog qhov tseem ceeb hauv qab qhov kev saib xyuas 360 μm tus nqi.
Tswv yim siv:Hom 3 muaj txwv geometric margin rau lub voj voog no.
Hom 4 Screen
8 × 38 μm = 304 μm
Lub 275 μm aperture tseem nyob hauv qab qhov kev xav tau.
275 ÷ 38 ≈ 7.2
Kwv yees li xya sab saum toj - qhov loj me tuaj yeem ncav cuag txoj kab uas hla. Hom 4 tseem tuaj yeem luam tawm tau zoo thaum muab tshuaj txhuam, stencil thiab lub tshuab luam ntawv tswj tau zoo, tab sis nws tsis txaus siab rau yim - particle screen.
Hom 5 Screen
8 × 25 μm = 200 μm
Lub 275 μm aperture tshaj tus nqi no.
Tswv yim siv:Hom 5 muab cov khoom muaj zog dua - qhov loj me thiab tsim nyog rau kev txiav txim siab thaum Hom 4 tsis tuaj yeem tsim cov ntim ntim ruaj khov lossis tso tawm.
Vim li cas Pob- suav cov cai tsuas yog thawj lub vijtsam xwb
Ib qho muab tshuaj txhuam tuaj yeem dhau qhov geometric particle screen thiab tseem luam tawm tsis zoo. Hmoov-rau- kev sib piv aperture tsis yog tag nrho rau cov rog uas tuav muab tshuaj txhuam hauv cov stencil.
Thaj tsam piv
Thaj tsam piv piv rau thaj chaw qhib qhov qhib nrog qhov aperture - cheeb tsam phab ntsa. IPC-7525C txhais qhov geometry no hauv nws cov qauv kev taw qhia stencil.
Rau ib tug rectangular aperture:
luas luas=L × W ÷ [2 × T × (L + W)]
Qhov twg L yog aperture ntev, W yog aperture dav thiab T yog stencil thickness.
Rau lub voj voog aperture:
Thaj tsam piv=D ÷ 4T
Qhov twg D yog aperture txoj kab uas hla thiab T yog stencil thickness.
Chaw Ua Haujlwm - Piv piv piv piv
Xav txog lub aperture rectangular nrog:
- L=0.40 hli;
- W=0.20 hli;
- T=0.10 hli.
Luas=0.40 × 0.20 ÷ [2 × 0.10 × (0.40 + 0.20)]
Thaj tsam piv=0.08 ÷ 0.12 ≈ 0.67
Tus nqi no yog ze rau cov tsoos 0.66 siv feem ntau siv rau kev luam ntawv stencil. Nws tseem yog thawj qhov kev siv engineering es tsis yog kev lees paub thoob ntiaj teb. Muab tshuaj pleev ib ce, aperture- phab ntsa zoo, txheej thiab kev tswj cov txheej txheem tuaj yeem hloov qhov peev xwm tiag tiag.
Yog hais tias stencil thickness nce thaum lub aperture qhov ntev nyob twj ywm tib yam, phab ntsa cheeb tsam nce thiab tso tawm feem ntau yuav nyuaj dua. Lub pob- suav cov txiaj ntsig tsis hloov, uas yog vim li cas kev tshuaj xyuas particle thiab thaj tsam piv yuav tsum tau txiav txim siab cais.
Hloov Efficiency
Transfer efficiency piv cov muab tshuaj ntim tso rau ntawm PCB nrog lub theoretical aperture ntim:
Hloov Efficiency=Deposited Paste Volume ÷ Theoretical Aperture Volume × 100%
Tus nqi yuav tsum raug soj ntsuam ua ke nrog qhov sib txawv ntawm qhov ntim thiab luam tawm -rau - luam ntawv sib xws. Ib qho kev tso nyiaj txais tau tsis ua pov thawj tias cov txheej txheem ruaj khov.
Lwm Yam Tseem Ceeb Uas Ua Rau Aperture Tso Tawm
Stencil Phab Ntsa Zoo thiab Txheej
Muab tshuaj txhuam yuav tsum cais tawm ntawm phab ntsa aperture thiab nyob twj ywm rau ntawm PCB ncoo. Kev tso tawm tuaj yeem cuam tshuam los ntawm laser-txiav zoo, phab ntsa roughness, cov ntaub ntawv ci, electropolishing, nanocoating, hnav, qhuav muab tshuaj txhuam thiab cov kab mob sib kis ntawm cov stencil underside.
Ib qho yooj yim, zoo-paperture khaws cia yuav luam tawm ntau dua li qhov ntxhib lossis kab mob aperture nrog tib qhov loj me.
Nominal Size Versus As -Ua Aperture Size
Kev kos duab qhov ntev yog qhov muaj txiaj ntsig zoo rau kev xaiv thaum ntxov, tab sis qhov ua tiav aperture tuaj yeem sib txawv vim yog kev txiav, xov thiab tshuaj xyuas qhov ntev. Thaum tus qauv tsim nyob ze rau qhov particle- qhov loj me lossis cheeb tsam - qhov sib piv txwv, siv ntsuas raws li - ua kom pom qhov ntev es tsis yog cia siab rau tus nqi nominal CAD xwb.
Muab tshuaj Rheology thiab txheej txheem txheej txheem
Solder hmoov tsuas yog ib feem ntawm cov muab tshuaj txhuam. Lub tsheb flux cuam tshuam rau viscosity, shear thinning, filling, slump, sib cais tus cwj pwm, tiv thaiv kom qhuav thiab rov qab los tom qab lub tshuab luam ntawv nres.
Kev luam ntawv kuj tuaj yeem hloov pauv nrog kev nrawm nrawm thiab siab, sib cais ceev, kev txhawb nqa lub rooj tsavxwm, stencil- mus rau - board gasketing, chav nyob, hnub nyoog muab tshuaj txhuam thiab kev tu ntau zaus. Tshooj lus ntawmYuav ua li cas flux chemistry cuam tshuam rau electronics los ua kepiav qhia vim li cas lub tsheb tsis tuaj yeem tsis quav ntsej.
Thaum sau zoo nkaus li tau txais tab sis tso tawm tseem tsis sib xws, thawj zaug tshuaj xyuas gasketing, aperture mob, kev coj tus cwj pwm sib cais thiab muab tshuaj txhuam ua ntej xav tias qhov loj me yog qhov ua rau nkaus xwb.
Rau -Powder Hom Xaiv Cov Txheej Txheem Ua Haujlwm
Kauj ruam 1: Nrhiav qhov tsawg tshaj plaws Aperture
Tshawb xyuas qhov ua tiav stencil es tsis yog tsuas yog cov khoom feem ntau. Sau qhov dav me tshaj plaws, txoj kab uas hla tsawg tshaj plaws, qhov ntev aperture, cov duab txawv txawv thiab cov kauj ruam hauv zos -stencil thickness.
Kauj ruam 2: Sau lub Aperture Shape
Muab faib rau txhua qhov tseem ceeb xws li duab plaub, square, voj voog, rounded square, home phaj, qhov rais -pane los yog lwm qhov kev cai geometry. Siv tsib-pob npo feem ntau rau qhov nqaim ntawm cov duab plaub thiab siv qhov kev ntsuam xyuas ntau dua rau qhov qhib qhov rooj.
Kauj Ruam 3: Tau qhov tseeb Powder Specification
Nug tus neeg muag khoom rau cov hmoov Hom, nominal ntau yam, sab sauv particle-size limit, particle-shape specification, test method and lot- tswj cov ntaub ntawv. Tsis txhob xam los ntawm qhov nruab nrab txoj kab uas hla ib leeg.
Kauj ruam 4: Siv lub Geometric Screen
Xam cov duab plaub qhov dav tsawg kawg nkaus muab faib los ntawm sab sauv particle txoj kab uas hla. Tus nqi qis dua tsib qhia pom tias cov hmoov zoo dua, qhov loj dua lossis qhov kev hloov tsim yuav tsum raug ntsuas.
Rau lub voj voog aperture, qhov tshwm sim hauv qab li yim yim tsim nyog yuav tsum tau ceev faj ntxiv vim tias qhov dav siv tau qis dua ntawm qhov nruab nrab.
Kauj Ruam 5: Xam cov cheeb tsam piv txwv
suav nrog qhov tseeb stencil thickness. Yog hais tias lub rooj tsavxwm muaj ob qho tib si loj thiab me me deposits, sib piv hloov hmoov hom nrog lwm yam xws li ib tug nyias nyias, kauj ruam stencil, hloov aperture, txheej los yog lwm txoj kev deposition. Cov lus qhia rausolder paste daim ntawv thov txoj kevmuab cov txheej txheem dav dav.
Kauj Ruam 6: Siv tau nrog Repeated Printing thiab SPI
Ntsuas cov ntim ntim, hloov pauv kev ua tau zoo, ntim qhov sib txawv, aperture- rau- aperture zoo ib yam, luam tawm-rau- luam ntawv sib xws, tus cwj pwm tom qab ncua, tus cwj pwm hla lub neej stencil, kev sib kis hauv qab, kev sib txuas, kev poob qis thiab rov ua haujlwm.
Solder paste soj ntsuamtshwj xeeb tshaj yog muaj txiaj ntsig vim nws ntsuas qhov tso nyiaj ua ntej tso thiab rov qab tuaj yeem nkaum qhov teeb meem luam ntawv qub. Txoj kev dav dav rauntsuam xyuas kev ua tau zoo ntawm soldertuaj yeem txhawb txoj kev npaj tsim nyog kawg.
Hom Hmoov-Kev xaiv yuam kev
Xaiv hom hmoov nkaus xwb los ntawm Lub Npe Lub Npe
BGA suab lossis nti- kev xaiv cov khoom siv tsis tuaj yeem xav tau ib hom hmoov universal. Pad tsim, aperture qhov ntev, stencil thickness, aperture shape, paste formulation thiab txheej txheem muaj peev xwm txiav txim qhov tseeb yuav tsum tau.
Saib tsuas yog Qhov Nruab Nrab Particle Loj
Lub sab sauv kawg ntawm kev tswj kev faib khoom yog qhov cuam tshuam ntau dua rau kev ntsuas ntsuas geometric. Ob yam khoom uas sau nrog tib Hom tseem tuaj yeem muaj qhov sib txawv ntawm kev faib khoom thiab luam tawm tus cwj pwm.
Piv txwv tias Finer hmoov yog ib txwm zoo dua
Cov hmoov hmoov zoo tuaj yeem muab cov paj ntau dua rau cov apertures me me, tab sis nws tuaj yeem tsim qhov sib txawv cia, oxidation, reflow thiab cov nqi txiav txim siab. Xaiv cov hmoov coarsest uas muab cov txheej txheem ruaj khov validated.
Tsis quav ntsej Stencil Thickness lossis Zoo li
Pob- suav cov cai tsis suav nrog cov ntawv tuab, thiab qhov sib npaug nominal qhov ntev tsis ua rau lub voj voog thiab cov duab plaub sib npaug. Thaj tsam piv thiab geometry yuav tsum tau tshuaj xyuas ua ke.
Kho qhov Engineering Heuristic raws li tus qauv yuav tsum tau muaj
Tsib -txoj cai pob thiab kev tiv thaiv ib puag ncig- ntim npo txhawb kev xaiv thaum ntxov. Kev pom zoo yuav tsum cia siab rau cov duab kos tam sim no, cov khoom siv tshwj xeeb, cov qauv siv tau thiab cov ntaub ntawv txheej txheem tiag tiag.
Pom zoo Paste los ntawm Ib Daim Ntawv Luam
Cov txheej txheem uas ua haujlwm tam sim tom qab teeb tsa yuav coj txawv txawv tom qab ib ntus lossis ob peb teev ntawm stencil. Kev tsim nyog yuav tsum siv ntau cov ntawv luam tawm thiab lub qhov rais tsim tawm.
Dab tsi suav nrog hauv Solder Paste RFQ
Muab cov ntaub ntawv txheej txheem txaus rau tus neeg muag khoom kom pom zoo kom ua tiav cov txheej txheem es tsis yog tsuas yog hmoov Hom:
- solder alloy thiab lead -dawb lossis leaded yuav tsum tau;
- xav tau hmoov Hom, yog tias twb tau teev;
- tsawg tshaj plaws duab plaub aperture;
- nominal thiab ntsuas stencil thickness;
- tseem ceeb aperture duab;
- me me feem suab;
- luam ntawv, dispensing los yog jetting method;
- Kev faib tawm flux thiab kev tu kom huv;
- reflow huab cua;
- cia tej yam kev mob thiab xav tau stencil lub neej;
- kev tso tawm tam sim no, hloov pauv- teeb meem kev ua tau zoo lossis tsis raug;
- xav tau pob loj thiab noj.
Rau semiconductor thiab nplua - cov ntawv thov tshwj xeeb, tshuaj xyuas qhov muajsemiconductor solder pastekev xaiv. Qhov twg tus txheej txheem siv tsis yog -kev sib cuag deposition es tsis yog ib tug pa stencil,dav hlau - luam ntawv solder pastetej zaum yuav xav tau txoj kev xaiv sib txawv.
Alloy xaiv tseem yog ib feem ntawm tag nrho cov specification. Cov lus qhia rauCommon tin solder alloys rau PCB los ua ketuaj yeem pab txhais cov lus nug alloy ua ntej thov kev pom zoo.
FAQ
Q: Puas yog tsib - pob txoj cai yog qhov yuav tsum tau IPC?
A: Nws yog dav siv raws li cov txheej txheem engineering, tab sis nws tsis yog cov khoom tiav lossis cov txheej txheem tsim nyog. Cov qauv siv tau, kos duab, cov neeg siv khoom tshwj xeeb thiab cov ntaub ntawv siv tau ua ntej.
Q: Puas yog yim -pob txoj cai yog IPC qhov yuav tsum tau muaj rau lub voj voog apertures?
A: Nws yuav tsum raug kho raws li kev saib xyuas engineering heuristic rau lub voj voog ntim, tsis yog raws li qhov xav tau thoob ntiaj teb IPC. Qhov tseeb muaj peev xwm nyob ntawm qhov ua tiav stencil thiab paste txheej txheem.
Q: Hom 4 puas tuaj yeem luam tawm 0.20 hli duab plaub?
A: Siv 38 μm qhov loj me me, tsib - pob qhov pib yog 190 μm. Ib qho 200 μm qhib nqaim dhau ntawm lub vijtsam geometric, tab sis thaj tsam piv thiab rov kuaj xyuas dua yuav tsum tau kuaj xyuas.
Q: Puas yog Hom 5 ib txwm zoo dua li Hom 4?
A: Tsis yog. Hom 5 muab ntau qhov geometric margin rau me me apertures, tab sis qhov kev xaiv raug kuj yog nyob ntawm kev tso tawm, reflow tus cwj pwm, cia, nqi thiab ntau lawm stability.
Q: Hom 4.5 solder paste yog dab tsi?
A: Hom 4.5 yog tus neeg muag khoom lossis kev qhia tshwj xeeb uas siv rau kev faib tawm ntawm hom 4 thiab Hom 5. Tsis txhob xav tias universal ntau yam; siv cov ntaub ntawv cov khoom siv tiag tiag thiab cov khoom sab saud - qhov txwv loj.
Q: Puas yog thaj tsam piv tau hloov tsib- txoj cai pob?
A: Tsis yog. Particle suav tshuaj xyuas cov hmoov loj txheeb ze rau qhov aperture. Cheeb tsam piv ntsuas qhov qhib thaj tsam piv rau aperture- phab ntsa. Lawv teb cov lus nug sib txawv thiab tej zaum yuav xav tau ob qho tib si.
Q: Yuav ua li cas qhov kev xaiv zaum kawg raug txheeb xyuas?
A: Siv rov luam tawm dua, SPI cov ntaub ntawv, ncua kev sim, stencil- kuaj lub neej thiab rov qab tshuaj xyuas raws li kev npaj tsim khoom.
Xaus
Tsib - txoj cai pob thiab ib puag ncig zoo nkauj - aperture npo yog txoj hauv kev muaj txiaj ntsig zoo los sib piv cov hmoov nplej hmoov loj loj nrog stencil geometry. Lawv yog thawj lim dej, tsis lav.
Pib nrog qhov tsawg tshaj qhov tseem ceeb aperture thiab tus neeg muag khoom qhov tseeb sab saud - qhov txwv loj. Tom qab ntawd tshuaj xyuas stencil thickness, xam thaj tsam piv, tshuaj xyuas qhov ua tiav aperture thiab siv tau cov kev hloov pauv nrog rov luam ntawv thiab SPI.
Lub hom phiaj yog tsis qhia meej cov hmoov zoo tshaj plaws muaj. Nws yog xaiv cov hmoov thiab muab tshuaj txhuam uas tsim cov khoom ruaj khov, rov ua dua cov nyiaj tau los thoob plaws lub qhov rais tsim khoom.
Rau kev pom zoo raws li alloy, hmoov Hom, aperture geometry, stencil thickness thiab luam ntawv, siv covYIHMA daim ntawv nuglos yoghu rau pab neeg YIHMA.
