Peb txhua tus cia siab tias cov txheej txheem SMT zoo meej, tab sis qhov tseeb yog qhov phem.Cov hauv qab no yog qee qhov kev paub txog cov teeb meem tshwm sim ntawm SMT cov khoom lag luam thiab lawv cov kev tiv thaiv.
Tom ntej no, peb piav qhia txog cov teeb meem no.
1. Tombstone tshwm sim
Tombstoning, raws li qhia, yog ib qho teeb meem nyob rau hauv uas daim ntawv Cheebtsam sawv ntawm ib sab.Qhov teeb meem no tuaj yeem tshwm sim yog tias qhov nro ntawm ob sab ntawm qhov tsis sib npaug.
Txhawm rau tiv thaiv qhov no tshwm sim, peb tuaj yeem:
- Nce lub sij hawm nyob rau hauv lub active cheeb tsam;
- Optimize pad tsim;
- Tiv thaiv oxidation los yog kis kab mob ntawm cov khoom xaus;
- Calibrate qhov tsis sib xws ntawm solder paste tshuab luam ntawv thiab tso tshuab;
- Txhim kho tus qauv tsim.
2. Tus choj
Thaum solder paste tsim ib qho txawv txav ntawm cov pins lossis cov khoom, nws yog hu ua tus choj txuas.
Cov kev ntsuas muaj xws li:
- Calibrate lub tshuab luam ntawv los tswj cov duab luam;
- Siv cov tshuaj txhuam hniav nrog qhov tseeb viscosity;
- Optimizing lub aperture ntawm lub template;
- Optimize xaiv thiab tso cov cav tov los kho qhov chaw ua haujlwm thiab siv lub siab.
3. Cov khoom puas
Cov khoom siv yuav muaj cov kab nrib pleb yog tias lawv puas yog cov khoom siv raw lossis thaum muab tso thiab rov ua dua
Txhawm rau tiv thaiv qhov teeb meem no:
- Tshawb xyuas thiab pov tseg cov khoom puas;
- Tsis txhob sib cuag tsis tseeb ntawm cov khoom thiab cov tshuab thaum ua SMT;
- Tswj qhov cua txias qis dua 4 ° C ib ob.
4. kev puas tsuaj
Yog tias cov pins puas lawm, lawv yuav tshem tawm cov ntaub qhwv thiab qhov yuav tsis tuaj yeem ua rau cov ntaub qhwv.
Txhawm rau zam qhov no, peb yuav tsum:
- Tshawb xyuas cov khoom pov tseg qhov chaw nrog cov pins tsis zoo;
- Tshawb xyuas manually muab qhov chaw ua ntej xa lawv mus rau cov txheej txheem reflow.
5. Tsis ncaj ncees lawm txoj hauj lwm los yog orientation ntawm qhov chaw
Qhov teeb meem no suav nrog ntau qhov xwm txheej xws li misalignment lossis tsis ncaj ncees lawm kev taw qhia / polarity qhov twg cov khoom yog welded nyob rau hauv cov lus qhia.
Kev tiv thaiv:
- Kev kho qhov tsis zoo ntawm lub tshuab tso kawm;
- Txheeb xyuas qhov chaw muab tso rau hauv manually;
- Tsis txhob sib cuag yuam kev ua ntej nkag mus rau cov txheej txheem reflow;
- Kho lub airflow thaum lub sij hawm reflow, uas yuav tshuab ib feem ntawm nws txoj hauj lwm raug.
6. Solder paste teeb meem
Daim duab qhia txog peb qhov xwm txheej ntsig txog kev ntim tshuaj yaj yeeb:
(1) Ntau tshaj solder
(2) solder tsis txaus
(3) Tsis muaj solder.
Feem ntau muaj 3 yam ua rau muaj teeb meem.
1) Ua ntej, lub qhov template yuav raug thaiv los yog tsis raug.
2) Qhov thib ob, qhov viscosity ntawm cov tshuaj txhuam hniav yuav tsis raug.
3) Thib peb, tsis zoo solderability ntawm cov khoom lossis cov ntaub qhwv yuav ua rau tsis txaus lossis tsis muaj cov khoom siv.
Kev tiv thaiv:
- huv si template;
- Xyuas kom muaj kev sib raug zoo ntawm cov qauv;
- Precise tswj ntawm solder paste ntim;
- Muab pov tseg cov khoom siv lossis cov ntaub qhwv uas muaj qhov tsis zoo.
7. Cov pob qij txha tsis zoo
Yog tias qee cov kauj ruam tsis raug, cov pob qij txha yuav tsim cov duab sib txawv thiab tsis tau xav txog.
Lub qhov stencil tsis meej yuav ua rau (1) cov khoom siv.
Oxidation ntawm cov ntaub qhwv los yog cov khoom, lub sij hawm tsis txaus nyob rau hauv lub sij hawm ntub dej thiab qhov kub thiab txias tuaj yeem ua rau cov khoom siv solder thiab (2) solder qhov, tsis tshua muaj soldering kub thiab lub sij hawm luv luv soldering tuaj yeem ua rau (3) solder icicles.
Countermeasures yog raws li nram no:
- huv si template;
- Ci PCBs ua ntej SMT ua kom tsis txhob oxidation;
- Precisely kho qhov kub thiab txias thaum lub sij hawm vuam txheej txheem.
Cov saum toj no yog cov teeb meem zoo thiab cov kev daws teeb meem uas tau npaj los ntawm reflow soldering chaw tsim tshuaj paus Chengyuan Kev lag luam hauv cov txheej txheem SMT.Kuv vam tias nws yuav pab tau koj.
Post lub sij hawm: May-17-2023