Ib, Core cov teeb meem thiab tsis ua hauj lwm hom ntawm hluav taws xob rwb thaiv tsev
1. Rwb thaiv tsev degradation tshwm sim los ntawm ib puag ncig yam
Cov av noo siab: Thaum cov av noo siab tshaj 85% RH, cov dej molecules tsim txoj hauv kev ntawm cov ntaub ntawv rwb thaiv tsev, ua rau txo qis ntawm rwb thaiv tsev los ntawm ntau tshaj 50%.
Lub voj voog kub: Nyob rau hauv qhov kub sib txawv ntawm -40℃rau +85 degree, qhov sib txawv ntawm thermal expansion coefficient ntawm cov khoom yuav ua rau microcracks, txo qhov creepage nrug los ntawm 30%.
Tshuaj lom neeg muaj kuab paug: Corrosive tshuaj xws li ntsev tsuag thiab cov roj stains tuaj yeem ua rau cov txheej txheem rwb thaiv tsev, txo cov nplaim tsis kam mus rau 1/10 ntawm nws cov nqi pib hauv 24 teev.
2. Hom Failure Hom
Kev puas tsuaj hluav taws xob: Ntawm qhov hluav taws xob siab tshaj 500V, cov ntsiab lus tsis muaj zog (xws li tus pin soldering) muaj kev puas tsuaj tam sim ntawd, tso cov cua sov ntau.
Creepage corrosion: The conductive channel formed along the insulation surface continues to develop under high voltage difference (>1000V / mm), thaum kawg ua rau luv luv Circuit Court.
Static accumululation: Cov hluav taws xob zoo li qub (txog 15kV) tsim los ntawm kev sib txhuam lossis induction tuaj yeem nkag mus rau cov khoom siv rhiab xws li MOSFETs, ua rau muaj kev puas tsuaj mus tas li.
2, Kev xaiv thiab kev ua tau zoo ntawm cov khoom siv rwb thaiv tsev
1. Cov khoom siv rwb thaiv tsev yooj yim
PCB substrate: FR-4 (sab voltage Ntau dua lossis sib npaug ntawm 20kV / mm) lossis PTFE (tiv taus kub 260 degree) cov ntaub ntawv yuav tsum tau nyiam, thiab cov ntawv phenolic boards (tsuas muaj qhov hluav taws xob tsuas yog 5kV / mm) yuav tsum zam.
Sealing nplaum: siv ob -cov khoom siv epoxy resin (xws li EPON 828), nrog lub ntim resistivity ntawm 1 × 10 ¹⁵Ω· cm thiab kub tsis kam ntawm -60℃rau +180℃.
Rwb thaiv tsev gasket: xaiv polyimide (PI) zaj duab xis (thickness 0.1mm, withstand voltage 10kV), nrog ruaj khov dielectric tas li (3.4-3.6) thiab poob tangent<0.005.
2. Cov ntaub ntawv ib puag ncig tshwj xeeb
Cov ntaub ntawv pov thawj noo noo: Txau peb cov pov thawj xim (xws li Humisay 1B31) rau ntawm qhov chaw ntawm PCB, nrog rau qhov nqus dej tsawg dua 0.1%, uas tuaj yeem ua rau cov rwb thaiv tsev los ntawm 2 qhov kev txiav txim siab.
Arc resistant material: Ceramic coating (Al ₂ O ∝, thickness 50 μ m) is used in high-voltage contact areas, with an arc resistance time of>180 vib nas this (IEC 60112 tus qauv).
Conductive shielding layer: In severe electromagnetic interference scenarios, copper foil shielding (thickness 0.1mm, shielding effectiveness>80dB @ 1GHz) Ua kom ntseeg tau tias muaj kev sib txuas nrog hauv av xaim.
3, Rwb thaiv tsev optimization txheej txheem hauv kev tsim qauv
1. Creepage nrug thiab hluav taws xob clearance
Kev nyab xeeb tus qauv: Ua raws li IEC 60664-1, qhov kev ncua deb ntawm cov pa phem theem 3 (kev lag luam ib puag ncig) ntawm 240V ua hauj lwm voltage yuav tsum siab tshaj los yog sib npaug rau 3.2 hli, thiab cov hluav taws xob clearance yuav tsum siab tshaj los yog sib npaug zos rau 2.0mm.
Kev ntsuas optimization:
Teeb qhov sib cais (dav Ntau dua lossis sib npaug rau 1mm, qhov tob Ntau dua lossis sib npaug li 0.5mm) nyob ib puag ncig lub siab -voltage pins
Siv SMD Cheebtsam es tsis txhob dhau los ntawm - qhov khoom kom txo tau tus pin ntev
Teem daim kab xev tiv thaiv (dav Ntau dua lossis sib npaug li 2 hli) ntawm ntug ntawm PCB los tiv thaiv ntug tawm
2. Grounding thiab shielding tsim
Ib qho taw qhia hauv av: Sib nqus hlaws yog siv rau ntawm qhov sib txuas ntawm analog thiab digital circuits kom tsis txhob muaj kev cuam tshuam hauv av.
Shielding txheej kev kho mob:
Lub plhaub hlau yuav tsum ua kom ntseeg tau kev sib cuag nrog PCB hauv av dav hlau los ntawm daim hlau caij nplooj ntoos hlav (hu rau kev tiv thaiv<10m Ω)
Qhov kev pab them nqi ntawm cov txheej txheem braided ntawm cov shielded cable yuav tsum ntau dua los yog sib npaug rau 90%, thiab 360℃crimping txheej txheem yuav tsum tau siv rau kev txiav.
3. Qhov cuam tshuam ntawm thermal tsim ntawm rwb thaiv tsev
Thaum tshav kub kub dissipation txoj kev: xyuas kom meej tias lub dab dej kub yog khaws cia ntawm qhov deb ntawm Ntau dua los yog sib npaug li 5 hli los ntawm qhov siab -voltage cheeb tsam, los yog siv ib qho insulated thermal pad (xws li Bergquist GAP Pad) cais nws.
Kev ntsuas kub: Nruab NTC thermistor nyob ze ntawm cov khoom tseem ceeb xws li tus tsav tsheb rov qab ICs kom ua rau muaj kev tiv thaiv kev tiv thaiv thaum kub tshaj 85 degree.
4, Cov ntsiab lus tseem ceeb ntawm cov txheej txheem installation
1. Vuam thiab tu
Lead free soldering: Siv Sn Ag Cu alloy (melting point 217 degree) kom tsis txhob muaj kev puas tsuaj los ntawm cov hlau lead.
Flux residue: Siv tsis tu cov flux los yog siv ultrasonic tu (frequency 40kHz, lub sij hawm 3 feeb) tom qab soldering los xyuas kom meej ion residue<1.5 μ g/cm ².
2. Mechanical fixation
Rwb thaiv tsev screws: Siv PA66+30% GF cov khoom (nrog qhov hluav taws xob 15kV) kom tsis txhob siv cov ntsia hlau hlau ncaj qha rau hauv PCB.
Kev tswj lub siab: Tswj lub siab ruaj khov (0.5-0.7N · m) los ntawm lub tshuab hluav taws xob torque los tiv thaiv kev kub siab dhau los ua rau deformation ntawm rwb thaiv tsev gasket.
3. txheej txheem sealing
Nqus degassing: Ua ntej sealing, lub tshuab nqus tsev kho cov colloid (siab<10kPa, time 10 minutes) to eliminate local insulation weakness caused by bubbles.
Kev tswj kom zoo: Ob qho khoom siv epoxy resin yuav tsum tau kho ntawm 25℃rau 24 xuab moos, lossis kho kom sov (80℃/ 2 teev) txhawm rau txhawm rau txhawm rau txhawm rau sib txuas.
5, Kev ntsuas kev ua haujlwm rwb thaiv tsev thiab kev txheeb xyuas
1. Kev sim niaj hnub
Rwb thaiv tsev ntsuas: Siv 500V DC megohmmeter, thiab ntsuas tus nqi yuav tsum siab dua lossis sib npaug rau 100M Ω (IEC 60529 tus qauv).
Kev ntsuas hluav taws xob tiv thaiv: Siv 1500V AC (1 feeb) lossis 2121V DC (1 thib ob), thiab cov xau tam sim no yuav tsum yog<5mA (UL 60950 standard).
2. Kev simulation ib puag ncig
Kev ntsuas cua sov: Tom qab muab tso rau hauv ib puag ncig ntawm 85℃/ 85% RH rau 96 teev, qhov ntsuas hluav taws xob tsis zoo yuav tsum tsawg dua 50%.
Tshuaj tsuag ntsev: thaum raug 5% NaCl tov tshuaj tsuag ib puag ncig rau 48 teev, tsis muaj corrosion khoom ntawm qhov chaw.
Kub caij tsheb kauj vab: Ua 20 lub voj voog ntawm -40℃thiab +85℃yam tsis muaj kev puas tsuaj mus tas li ntawm kev ua haujlwm rwb thaiv tsev.
3. Kev txheeb xyuas kev ntseeg tau ntev
Kev ntsuas lub neej nrawm: Tom qab ua haujlwm tas li rau 1000 teev ntawm 60 degree, 85% RH, thiab 1.2 npaug ntawm qhov ntsuas hluav taws xob, qhov tsis ua haujlwm yuav tsum tsawg dua 0.1%.
HALT kuaj: Txheeb xyuas qhov tsim tsis muaj zog los ntawm cov xwm txheej hnyav xws li kev hloov pauv kub ceev (-55℃rau +125℃/ min) thiab random vibrations (50g RMS).
6, Cov ntaub ntawv thov raug
Hauv kev tswj hwm ntawm qee cov roj drilling platform, qhov ntsuas LCD yuav tsum ua haujlwm ruaj khov hauv 120℃roj paug ib puag ncig. Los ntawm kev siv cov kev ntsuas hauv qab no:
Siv PI nyias zaj duab xis rwb thaiv tsev gasket (thickness 0.2mm, kub tsis kam 300 degree)
Spray nano coating on the surface of PCB (contact angle>150 degree) tiv thaiv cov roj stains los ntawm adhering
Silicone roj hmab (Shore A 30, kub tsis kam -60℃rau +200 degree) yog siv rau sealing
Txheeb xyuas los ntawm "Oil Mist Corrosion Test" hauv IEC 60068-2-64 tus qauv
Lub kaw lus tau ua haujlwm tsis tu ncua rau 5 xyoos, nrog kev tiv thaiv kev tiv thaiv ib txwm khaws cia siab dua 500M Ω thiab tsis muaj hluav taws xob tawg lossis creepage faults tau tshwm sim.
