Daim duab 1.Hauv cov xaim- cov kev sib koom ua ke, cov epoxy rigid potting siv kho qhov kev ntxhov siab tom qab hla cov hlua khi hlua khi. Qhov kev ntxhov siab ua rau lub hauv siab pob taws - tus ntoo khaub lig tsis muaj zog tshaj - ntu hauv cov xaim - thiab qhov tsis ua haujlwm tshwm sim tom qab ntau lub voj voog thermal, tsis yog ntawm qhov kev sim thawj zaug.
Cov lus qhia tshwj xeeb hu ua nplaim taws -cov khoom siv hluav taws xob epoxy potting compound. Ib qho nyuaj, siab -modulus system tau xaiv - zoo-tus yam ntxwv, UL- teev, sau tseg Tg thiab lub zog dielectric. Pab pawg engineering tau ntseeg siab rau cov khoom siv xaiv. Rau lub hlis rau hauv kev tsim khoom, xaim daim ntawv cog lus tsis ua tiav pib tshwm hauv cov khoom xa rov qab. Tsis yog tag nrho cov khoom xa rov qab - kwv yees li 3% ntawm cov khoom xa tuaj los ntawm cov hnub tshwj xeeb. Hla-section tsom xam qhia txog kev sib txuas ntawm cov hlua khi ntawm pob taws, tsis muaj pov thawj ntawm dhau-tam sim no lossis kev poob siab. Lub metallurgy ntawm cov hlau yog qhov qub. Cov tuag txuas tsis zoo. Daim ntawv cog lus rub lub zog ntawm cov khoom tuaj yog nyob rau hauv specification.
Qhov kev tshawb nrhiav tsis pom - vim tias nws tsis nyob hauv daim ntawv txheeb xyuas qhov tsis ua haujlwm - yog qhov tawg tau tshwm sim ntawm pob taws ntawm lub voj voos vim tias cov epoxy khov kho thiab cog lus nyob ib puag ncig cov hlau, rub lub voj tom qab raws li nws shrink, concentrating kev ntxhov siab precisely ntawm lub pob taws qhov twg hlau hla lub cev -section AB. Cov khoom siv tsis yog cov chaw tsim khoom tsis raug. Nws yog qhov tsis ncaj ncees lawm modulus.
Feem ntau cov kev sib koom ua ke thiab cov hlau nplaum qaug zog ua tsis tiav hauv cov khoom sib dhos yog tsim los ntawm cov encapsulant, tsis yog los ntawm kev sib koom ua ke. Lub encapsulant siv cov kev ntxhov siab. Hloov qhov sib koom ua ke geometry, alloy, lossis hlau txoj kab uas hla tsis hais txog qhov kev ntxhov siab uas yog sab nraud rau qhov sib koom ua ke.
Dab tsi Rigid Epoxy Ua Thaum Kho
Thaum ob -cov khoom siv epoxy sib xyaw thiab xa mus rau hauv cov kab noj hniav uas muaj cov khoom siv hluav taws xob, tus ntoo khaub lig- txuas cov tshuaj tiv thaiv uas ua rau cov khoom kho tau zoo kuj ua rau lub ntim ntim. Rau feem ntau nruj epoxy potting systems, linear shrinkage yog nyob rau hauv thaj tsam ntawm 0.2-1.0%. Hauv cov ntsiab lus tseeb, 0.5% linear shrinkage hla 30 mm kho seem txhais tau tias 150 μm ntawm contraction. Qhov kev cog lus no yog txwv los ntawm cov khoom sib xyaw thiab cov kab noj hniav, uas tsis txav mus los. Cov resin tsis tuaj yeem cog lus ywj pheej - nws yog tuav los ntawm nws qhov adhesion rau txhua qhov chaw nws ntub. Qhov tshwm sim yog qhov kev ntxhov siab uas tau muab faib thoob plaws hauv cov ntim kho, nrog rau qhov siab tshaj plaws ntawm cov yam ntxwv nruj tshaj plaws: cov khoom siv lead ua, cov hlua khi, cov khoom siv, thiab cov potting - mus rau - vaj tse interface.
Nyob rau hauv nruj, siab -modulus system (Shore D 75–95), cov polymer kho tsis tuaj yeem deform loj heev los txo qhov kev ntxhov siab no. Qhov chaw ntxhov siab uas tau teeb tsa thaum kho tau tseem nyob hauv qhov kho tau raws li qhov xauv - hauv kev thauj khoom. Txhua qhov sib xyaw ua ke thiab txhua qhov sib txuas hauv kev sib cuag nrog lub potting yog nyob rau hauv kev ruaj ntseg, zoo li qub kev ntxhov siab los ntawm kev kho encapsulant - ua ntej cov kev pabcuam thauj khoom, ua ntej kev caij tsheb kauj vab, ua ntej kev co.
Qhov loj ntawm qhov kev ntxhov siab no nyob ntawm qhov shrinkage magnitude, modulus ntawm kho epoxy, modulus ntawm substrate thiab cov khoom, thiab cov geometry. Rau cov txheej txheem nruj nruj ntawm lub rooj tsav xwm hauv Circuit Court nrog los ntawm - qhov thiab SMT cov khoom, kho qhov kev ntxhov siab ntawm kev sib koom tes sib txuas tuaj yeem ncav cuag 5-15 MPa - zoo hauv qab lub zog tensile kawg ntawm kev sib koom tes, tab sis txaus los txo nws lub neej qaug zog thaum ua ke nrog kev pabcuam loads.
Thermal Cycling Amplification
Kho shrinkage kev nyuaj siab yog ib qho kev thauj khoom zoo li qub. Thermal cycling yog dynamic load. Hauv kev pabcuam, txhua qhov kev tawm mus los ntawm kev kho qhov kub thiab txias ua rau muaj kev ntxhov siab ntxiv ntawm txhua qhov sib txuas uas CTE ntawm epoxy txawv ntawm CTE ntawm cov khoom uas nyob ib sab. Qhov kev ntxhov siab amplitude ib lub voj voog yog nyob ntawm CTE mismatch, qhov kub thiab txias excursion magnitude, thiab nruj ntawm cov ntaub ntawv.
Rau cov tawv epoxy (CTE ~ 50–70 ppm /℃hauv qab Tg) sib txuas rau FR-4 PCB (CTE ~ 14–18 ppm /℃hauv- dav hlau, ~ 60–80 ppm /℃tawm- ntawm - dav hlau), tooj liab ~ 18 ppm lub cev (C) (CTE ~ 7-10 ppm / degree), thiab ib qho txhuas thaiv (CTE ~ 23 ppm / degree), CTE tsis sib haum ntawm txhua qhov sib cuam tshuam tsim kev ntxhov siab thaum txhua qhov kev hloov kub. Nyob rau hauv ib tug nruj encapsulant, qhov kev ntxhov siab shear tsis tuaj yeem daws tau los ntawm kev deformation ntawm lub encapsulant - nws kis tau mus rau qhov tsis muaj zog tshaj plaws hauv kev thauj khoom.
Qhov tsis muaj zog interface yog nyob ntawm qhov sib dhos geometry. Hauv xaim- cov qauv sib txuas, feem ntau nws yog daim ntawv cog lus pob taws lossis daim ntawv cog lus thib ob (daim ntawv cog lus). Nyob rau hauv zoo - suab SMT cov rooj sib txoos, nws yog qhov sib koom ua ke ntawm lub ces kaum- feem ntau cov haujlwm ua haujlwm, qhov twg qhov eccentricity los ntawm qhov nruab nrab ntawm qhov nruab nrab yog siab tshaj. Hauv coil lossis transformer sib dhos nrog cov khoom siv hlau sib xyaw, nws yog epoxy- mus rau - vaj tsev interface qhov twg CTE tsis sib haum ntawm cov khoom sau, cov xaim, thiab cov ntaub thaiv ua rau lub siab tshaj plaws shear.
Kev sib xyaw ua ke ntawm kev kho shrinkage zoo li qub kev ntxhov siab ntxiv rau cyclic thermal stress txiav txim siab lub neej qaug zog ntawm kev sib koom ua ke. Lub sij hawm kho shrinkage kev ntxhov siab nce qib kev ntxhov siab. Lub sij hawm thermal cycling muab lub cyclic amplitude. Ob leeg pab txhawb kev tawg; tus nqi ntawm tawg propagation nyob ntawm ob nqe lus.
Vim Li Cas Lub Sijhawm Tsis Ua Haujlwm Ua rau Misidentification
Kev ntxhov siab- hloov pauv tsis ua hauj lwm uas tau tsav los ntawm epoxy potting nruj tsis tshwm sim tam sim tom qab kho. Lub voj voog pib tawg yog nyob ntawm qhov sib xyaw ua ke ntawm kev ntxhov siab, uas yog kev ua haujlwm ntawm geometry thiab cov ntaub ntawv. Hauv kev sib koom ua ke, kev ua tsis tiav tshwm sim tom qab 100-500 thermal cycles hauv kev pabcuam, lossis tom qab ob peb lub hlis mus rau ib xyoos ntawm kev co tsis tu ncua. Qhov ncua sij hawm no ua rau muaj kev tsis txaus ntseeg tsis tu ncua:
Thaum kuaj thawj zaug- lub rooj sib txoos dhau tag nrho cov kev kuaj hluav taws xob, hi- lauj kaub, thiab kev tshuaj xyuas qhov muag. Txoj kev kho shrinkage kev ntxhov siab yog tam sim no tab sis qis dua qhov pib tawg. Tsis pom qhov ua tsis tiav.
Thaum ntxov siv- lub rooj sib txoos ua haujlwm ib txwm. Cov thermal cycles sib sau tsis tau mus txog qhov pib tawg. Tsis pom qhov ua tsis tiav.
Thaum 3-12 lub hlis hauv kev pabcuam- kev ua tsis tiav pib tshwm. Kev tshawb nrhiav tsom mus rau qhov ua tsis tiav lossis kev sib koom ua ke, tsis yog nyob rau hauv lub encapsulant. Hlau daim ntawv cog lus rub lub zog ntawm cov xaim xa rov qab tuaj yeem ua tau raws li cov lus qhia tuaj vim tias cov xov hlau tsis ua haujlwm tsis zoo li qub - cov neeg txheeb cais ntawm cov xov hlau tsis tau twb nyob hauv cov chav ua tsis tiav.
Thaum tsis ua hauj lwm tsom xam- cross-sections qhia kev tawg ntawm lub pob taws los yog solder sib koom ua ke. Qhov kev tshawb nrhiav ua rau qhov no ua rau kev qaug zog ntawm metallurgical, uas yog technically meej - qaug zog tawg tawm yog qhov kawg tsis ua haujlwm hom - tab sis tshem tawm lub hauv paus ua rau: nce kev ntxhov siab amplitude los ntawm nruj encapsulant.
Qhov tseeb hauv paus kev txheeb xyuas yuav tsum tau muab piv rau qhov tsis ua hauj lwm tus nqi thiab tawg qhov chaw qauv nrog dab tsi yuav xav tau los ntawm kev ntsuas kev ntxhov siab hauv cov potted geometry. Cov kab nrib pleb uas pib ntawm kev kwv yees siab siab - qhov chaw muaj kev ntxhov siab (cov pob luj taws hauv cov hlau- cov khoom sib txuas, cov khoom siv kaum hauv SMT arrays, cov hlau lead tawm hauv potted coils) faib sib npaug thoob plaws cov pej xeem - es tsis yog nyob ntawm qhov chaw random - zoo ib yam nrog cov txheej txheem kev ntxhov siab nyob rau hauv lub encaps.
Tsawg-Modulus Encapsulant Ua Dab Tsi txawv
Ib nrab - hloov pauv epoxy nrog Shore A 80-90 thiab elongation ntawm kwv yees li 140% teb rau kev kho cov shrinkage thiab thermal cycling kev ntxhov siab los ntawm deforming, es tsis hloov kev ntxhov siab rau cov khoom sib xyaw. Lub modulus ntawm Shore A 80 cov khoom yog kwv yees li ob qhov kev txiav txim siab qis dua Shore D 80 - tib txoj kev uas cov roj hmab band thiab cov pas nrig steel teb sib txawv rau tib lub zog siv. Cov roj hmab band deforms. Cov pas hlau xaim hluav taws xob.
Thaum qhov qis -modulus encapsulant kho thiab ntsws, nws tsis tuaj yeem ua rau muaj kev ntxhov siab siab ntawm kev sib cuam tshuam vim nws qhov tawv nqaij tsis txaus los txhawb nqa qhov kev ntxhov siab loj. Lub shrinkage tshwm sim, tab sis cov resin deforms kom haum nws es tsis xa cov contraction load rau cov khoom uas nyob ib sab. Lub xeev kev ntxhov siab nyob hauv qhov kho tau qis dua hauv cov txheej txheem nruj nrog tib qhov qis qis.
Thaum lub sij hawm thermal cycling, qhov qis -modulus system deforms kom haum rau qhov sib txawv CTE txav ntawm cov epoxy thiab cov khoom embedded. Lub shear stress ntawm lub interface yog txo vim hais tias lub encapsulant txav nrog lub substrate es tsis txhob tiv nws. CTE tsis sib haum tseem muaj nyob - cov ntaub ntawv tsis tau hloov pauv - tab sis qhov kev ntxhov siab uas tshwm sim los ntawm qhov tsis sib haum yog absorbed los ntawm lub encapsulant deformation es tsis yog hloov mus rau qhov sib koom ua ke.
Qhov no yog lub hauv paus engineering rau kev qhia txog ib nrab - hloov tau yooj yim. Nws tsis yog tias lub semi- hloov tau yooj yim ua rau lub rooj sib txoos muaj zog. Nws yog hais tias lub semi- hloov tau yooj yim tshem tawm cov encapsulant raws li qhov kev ntxhov siab, tso cai rau lub rooj sib txoos ua haujlwm raws li nws cov qauv tsim tsis muaj kev txwv ntxiv los ntawm cov potting compound.
Daim duab 2.Ib qho tawv epoxy tsis tuaj yeem deform kom haum raws li kev kho mob shrinkage - qhov kev ntxhov siab raug xa mus rau qhov tsis muaj zog tshaj plaws hauv kev thauj khoom. Ib qho kev hloov pauv ib nrab - nrog ~ 140% elongation deforms hloov pauv, tshem tawm cov encapsulant raws li qhov kev ntxhov siab yam tsis hloov pauv qhov sib koom ua ke.
Kev Lag Luam -Offs ntawm Tsawg Modulus: Semi - Yooj Yim Ua Tsis Tau
Cov khoom uas ua rau ib nrab- hloov pauv tau zoo rau kev daws kev ntxhov siab yog tib yam khoom uas ua rau nws tsis tsim nyog rau cov ntawv thov uas xav tau kev siv tshuab rigidity, kev txhawb nqa cov qauv, lossis kev ua haujlwm hnyav:
Dimensional stability nyob rau hauv sustained mechanical load.Ntug A 80-90 yuav nkag mus rau hauv kev txhawb nqa compressive lossis shear load. Yog hais tias lub potted los ua ke yog mechanically constrained los ntawm ib tug xovxwm - haum tus pin, tuav -down bracket uas exerts sustained quab yuam, los yog ib tug connector uas kis tau tus quab yuam mus rau hauv potted cheeb tsam, lub semi- saj zawg zog matrix yuav deform raws sij hawm. Yuav tsum muaj epoxy nruj rau kev thauj khoom -cov ntaub ntawv siv.
Thermal conductivity.Semi- cov tshuab hloov tau yooj yim muaj cov thermal conductivity zoo ib yam li cov txheej txheem nruj potting compounds - feem ntau 0.5–0.7 W/m·K. Yog tias tus qauv tsim kom muaj txheej txheej potting los ua cua sov los ntawm lub hwj chim- dissipating tivthaiv mus rau qhov chaw txias, ib nrab - qhov hloov pauv ntawm theem conductivity no yuav tsis muaj txiaj ntsig kev txhim kho thermal. Yuav tsum muaj cov txheej txheem thermally conductive rigid (1.0–1.5 W / m·K).
Thick -section cwj pwm.Cov cuab yeej elongation uas ua rau ib nrab- hloov pauv tau yooj yim siv tau rau kev daws kev ntxhov siab yog nrog los ntawm kev tsim hluav taws xob ntau dua rau ib chav tsev ntim ntawm qhov nruab nrab ntawm cov dej tuab, vim tias qib catalyst ntau dua xav tau rau chav tsev-kub kho ua rau cov tshuaj tiv thaiv sai dua. Cov ntim loj ntim rau hauv qhov sib sib zog nqus tuaj yeem tsim kom muaj cua sov txaus kom ua rau lub zos overtemperature. Ntu thickness thiab ncuav ntim yuav tsum tau validated ua ntej ntau lawm.
Creep nyob rau hauv lub Upper kev pab cuam kub.A Shore A 80–90 qhov system ua haujlwm nyob ze nws qhov kev pabcuam kub siab tshaj (100℃rau ib txwm ib nrab-cov tshuab hloov tau yooj yim) yuav nthuav tawm cov nqi nkag siab dua li cov txheej txheem nruj ntawm tib qhov kub. Cov ntawv thov uas qhov kev txiav txim siab me me nyob rau hauv thermal load yuav tsum siv lub zog nruj, siab -Tg system.
Daim Ntawv Thov Cov Txheej Txheem Qhov twg Encapsulant Modulus yog Tus Txheej Txheem Kev Xaiv
Cov xwm txheej hauv qab no qhia tau hais tias qhov kev ntxhov siab -hloov mechanism yog kev tswj tsis tau qhov kev pheej hmoo, thiab qhov encapsulant modulus - es tsis yog lub zog dielectric, thermal conductivity, lossis Tg - yuav tsum tsav cov khoom xaiv:
Hlau- cov khoom sib txuas (kub lossis tooj liab hlau, pob lossis daim ntawv cog lus) muab ntim rau hauv cov khoom sib xyaw ua ke, ua haujlwm nyob rau hauv thermal cycling lossis vibration.
Zoo-pitch SMT sib dhos (0.5 hli suab lossis finer) nrog ntau hom khoom sib txawv muaj CTEs sib txawv - ceramic passives, pob khoom polymer, thiab hlau- lub cev inductors nyob rau hauv tib lub potted cheeb tsam.
PCBs nrog nyias, tsis muaj kev txhawb nqa los yog hloov tau yooj yim substrates nyob rau hauv nruj potting - rigidity sib txawv ntawm lub substrate thiab lub potting generates siab interfacial kev nyuaj siab thaum kho.
Ferrite core assemblies (transformers, inductors, common-mode chokes) qhov twg lub cev ferrite CTE (~10 ppm/degree) txawv ntawm cov epoxy nyob ib puag ncig CTE (~ 50-70 ppm /℃).
Sib sau ua ke nyob rau hauv qhov chaw tsis tu ncua kev co (automotive, industrial motor drives, sab nraum zoov fixtures) qhov twg cov cumulative cyclic load yog tus tseem ceeb tsis ua hauj lwm tsav tsheb.
Txhua lub rooj sib txoos uas yav dhau los ua tsis tiav keeb kwm qhia tau hais tias tawg, sib tshuam qhib, lossis delamination uas cuam tshuam nrog thermal voj voog suav es tsis yog nrog cov xwm txheej tshwj xeeb.
Modulus Xaiv raws li kev txiav txim siab tsim, tsis yog qhov qub
Cov txheej txheem xaiv cov txheej txheem rau epoxy potting tebchaw nyob rau hauv feem ntau B2B procurement workflows pib nrog nplaim taws ntsuam xyuas (UL 94 V-0), tsiv mus rau dielectric zog, thiab ces ntsuam xyuas lub sij hawm kho thiab Tg. Modulus thiab elongation feem ntau tau teev tseg nyob rau hauv TDS thiab tsis tshua hnyav hnyav hauv kev xaiv thawj zaug. Qhov kev txiav txim no qhia txog kev ua raws li qhov yuav tsum tau ua - qhov ntsuas hluav taws xob raug cai, lub zog dielectric ntsuas tau, cov qauv ntsuas tsis nyob hauv cov khoom siv feem ntau.
Qhov tshwm sim yog tias cov rooj sib txoos nrog cov txheej txheem ua haujlwm tsis tu ncua yog niaj hnub potted nrog nruj, siab -modulus compounds vim tsis muaj qhov rooj xaiv uas nug cov lus nug modulus. Cov lus qhia dhau los ua raws li kev tshuaj xyuas. Qhov tsis ua hauj lwm tshwm sim hauv daim teb. Kev tshawb nrhiav tsis rov qab mus rau txoj kev xaiv.
Txoj hauv kev kom raug yog ntxiv cov kev ntsuam xyuas kev ntxhov siab rau cov qauv tsim thaum ntxov - ua ntej potting compound xaiv. Cov lus nug "qhov kev ntxhov siab dab tsi no encapsulant siv rau kev sib dhos thaum kho thiab kev pabcuam?" yuav tsum tau teb ua ntej qhia ib yam khoom, tsis yog tom qab thawj daim teb rov qab.
Qhov no yuav tsum tau paub txog qhov kwv yees ntawm qhov shrinkage ntawm tus neeg sib tw compound, lub modulus ntawm kho system, CTE ntawm lub substrate thiab cov khoom, thiab cov geometry ntawm lub potted seem. Tsis muaj ib qho ntawm cov no yuav tsum muaj kev txheeb xyuas qhov tseeb - thawj - kev kwv yees kwv yees los ntawm cov khoom siv thiab cov duab geometry txaus los txiav txim siab seb qhov kev hloov pauv kev ntxhov siab puas yuav yog kev tswj hwm tsis ua haujlwm ua ntej xaiv cov khoom tiav.
Yam khoom rau kev ntxhov siab-Sensitive Assembly Potting
E759/H759 yog ob-cov khoom, ib nrab- hloov pauv epoxy potting compound nrog Shore A 80-90 thiab kwv yees li 140% elongation thaum so. Nws yog UL 94 V-0 ntawv pov thawj raws li UL File E120665 ntawm qhov tsawg kawg nkaus thickness 1.58–1.74 mm. Kev pabcuam kub yog -30℃rau +100℃. Mix ratio yog 100:30 los ntawm qhov hnyav; Lub lauj kaub lub neej yog kwv yees li 60 feeb rau 60 g hnyav ntawm 25 degree. Kev kho yog nyob rau hauv chav tsev kub (7 hnub ntawm 25 degree) los yog kub ceev (50–60℃× 2 teev + 80℃× 2 teev).
Nws yog qhov tsim nyog thaum qhov kev pheej hmoo tseem ceeb yog kev hloov pauv hloov pauv kev ntxhov siab - xaim daim ntawv cog lus qaug zog, kev sib koom ua ke tawg, CTE- tsis sib haum xeeb delamination, lossis kev vibration- ua rau tawg. Nws tsis tsim nyog rau kev thauj khoom -cov kabmob cov txheej txheem potting, siab - tshav kub-flux thermal tswj, los yog cov rooj sib txoos uas yuav tsum tau muaj Shore D rigidity rau qhov ntev ntev. Kev xaiv yuav tsum tau ua pov thawj ntawm cov qauv neeg sawv cev raws li qhov tseeb thermal voj voog profile ntawm daim ntawv thov.
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Cov lus nug tseem ceeb Engineering
Kuv yuav kwv yees li cas seb puas muaj kev ntxhov siab hloov hauv kuv lub rooj sib txoos tam sim no?
Ib qho kev kwv yees thawj zaug tuaj yeem ua los ntawm qhov shrinkage ntawm lub potting compound (los ntawm TDS, feem ntau teev raws li % linear shrinkage), lub modulus ntawm kho system (txuas nrog Shore D - Shore D 80 sib haum mus rau roughly 1,500–2,500 MPa tensile. Kev ntxhov siab ntawm ib qho kev sib txuas tsis sib haum yog kwv yees li E × ε, qhov twg E yog epoxy modulus thiab ε yog qhov kev txwv tsis pub muaj zog. Yog tias qhov txiaj ntsig tshwm sim yog ib feem tseem ceeb ntawm kev sib koom ua ke los yog xaim daim ntawv cog lus qaug zog, kev hloov kev ntxhov siab yuav tshwm sim. Qhov no yog qhov kwv yees kwv yees - geometry thiab cov ntsiab lus ntawm kev thauj khoom cuam tshuam rau qhov kev ntxhov siab tiag tiag - tab sis nws txheeb xyuas seb lub tshuab tau lees paub cov ncauj lus kom ntxaws los yog kev sim ntsuas ua ntej ua tiav cov khoom xaiv.
Yog tias tam sim no lub rooj sib txoos siv cov epoxy nruj thiab muaj keeb kwm tsis ua haujlwm raws li kev ntxhov siab hloov pauv, qhov kev ntsuam xyuas qhov tseeb yog dab tsi rau ib nrab - hloov pauv hloov tau?
Pib los ntawm kev lees paub qhov tsis ua haujlwm los ntawm kev hla - ntu kev tshuaj ntsuam ntawm cov khoom xa rov qab - tawg qhov chaw pib, tawg txoj kev nthuav dav, thiab kev sib raug zoo nrog cov thermal voj voog suav. Tom qab ntawd tsim cov qauv kuaj ntawm qhov sib dhos tiag tiag nrog cov semi- hloov pauv tus neeg sib tw ntawm tib lub geometry thiab kho lub sijhawm, thiab khiav nrawm nrawm mus rau lub voj voog suav uas suav nrog tib qhov tsis ua haujlwm tau pom nyob rau hauv daim teb (feem ntau 2–5 × lub voj voog suav qhov chaw ua tsis tiav thawj zaug). Sib piv tus nqi tsis ua hauj lwm thiab qhov chaw pib tawg ntawm qhov nruj thiab ib nrab- cov qauv hloov tau yooj yim. Cov txheej txheem no yuav siv sij hawm 4-8 lub lis piam nyob ntawm qhov muaj cov khoom siv thermal cycling, tab sis nws tsuas yog lub hauv paus txhim khu kev qha rau kev txiav txim siab hloov khoom siv. Cov ntaub ntawv sib piv ib leeg tsis kwv yees hauv - kev pabcuam tus cwj pwm rau qhov tsis ua haujlwm no.
Puas yog qhov qis dua -modulus system muab kev tiv thaiv ib puag ncig tsawg dua li qhov nruj?
Lub semi- hloov tau yooj yim ntawm Shore A 80-90 khaws cov kev tiv thaiv ib puag ncig - nws kaw lub rooj sib txoos tiv thaiv kev ya raws, muab hluav taws xob rwb thaiv tsev, thiab ua tau raws li UL 94 V-0 nplaim taws ua haujlwm. Dab tsi nws tsis muab yog mechanical rigidity - nws yuav deform nyob rau hauv sustained compressive load. Rau kev tiv thaiv ib puag ncig hauv kev tsis yog-load- cov ntawv thov cov kabmob, Shore A 80–90 yog qhov txaus. Qhov kev sib piv uas tseem ceeb yog seb qhov kev txo qis hauv cov qauv ntawm Shore D mus rau Shore A yog qhov cuam tshuam rau cov khoom siv tshwj xeeb thauj khoom lub rooj sib txoos yuav pom hauv kev pabcuam, tsis yog qhov kev hloov pauv ib nrab muab "tsawg tiv thaiv" hauv qhov kev nkag siab zoo.
Cov kauj ruam tom ntej - Hu rau Fong Yong Tshuaj
