Nkhaniyi ikufotokoza momwe angagwirizanitsire liwiro la mzere wa makina okutira ndi kutalika kwa uvuni kuti zitsimikizire kuti zomatira za organosilicone zikufika pa digiri yochiritsa ya tepi yotentha kwambiri ya PTFE. Mfundo yofananira yapakati: nthawi yonse yokhala t_total = kutalika kwa uvuni L ÷ liwiro la mzere v kuyenera kukhala kosachepera nthawi yochizira. Pezani machiritso kudzera ku DSC kapena kuyezetsa zomatira zomwe zimakhazikitsa ubale wa 'kutentha - nthawi yocheperako'. Mtundu wofananira wochiritsa: gawani uvuni m'magawo, werengerani ti=Li/v ndi tcure(Ti), onetsetsani ∑(ti/tcure(Ti)) ≥1. Njira zowerengera: ikani madera otentha ndi kutalika kwa Li ndi kutentha kwa Ti; khazikitsani liwiro la mzere v, kuwerengera nthawi yokhala ndi gawo lililonse ndi chiŵerengero cha zopereka; bwerezani mpaka ≥1 (malire achitetezo 1.1-1.2 akulimbikitsidwa).

Nkhaniyi ikufanizira kusiyana pakati pa kutentha kwa ma radiation a infrared ndi njira zochiritsira zotenthetsera pamlengalenga pamapangidwe ophatikizika amitundu yomatira ya silicone. Njira zosinthira kutentha: mpweya wotentha umadalira pa convection-conduction ndi kutentha pang'ono kutentha, kusiyana kochepa mkati / kunja kwa kutentha; IR ili ndi kuzama kochepa kolowera komwe kumayamwa mwamphamvu pamwamba (makumi mpaka mazana a ma micrometer) kumapanga kutsetsereka kotsetsereka kuchokera kumtunda kupita mkati. Zotsatira zakufanana kwa crosslink: mpweya wotentha umathandizira kuchiritsa kolumikizana mkati ndi kunja ndi kachulukidwe kofanana; IR imapangitsa kuti pamwamba pakhale 'filimu yapakhungu' yowundana yomwe imalepheretsa kutentha ndi kayendedwe ka mkati, zomwe zimapangitsa kuti kachulukidwe kawo kawongoleredwe kutsika kuchokera pamwamba kupita mkati.

Nkhaniyi ikufotokoza kuchulukana kwamalemberana pakati pa kagawo ka gel ndi mphamvu yolumikizana mu zomatira zomata za silikoni za tepi ya Teflon. Gawo la gel = kuchuluka kwa ma network olumikizidwa osasungunuka mu toluene (Soxhlet m'zigawo, 24hr). Mphamvu yogwirizana yodziwika ndi kutentha kwambiri (180 ° C, 1kg). Mitundu itatu: pansi pa mfundo yovuta (<60%) - palibe makina otsekemera, ogwiritsira ntchito mphamvu pafupi ndi zero; zothandiza zosiyanasiyana (60-85%) - mphamvu zogwirizana amakula exponentially ndi gel osakaniza kagawo, 60% → 70% amadzutsa kugwira ntchito mphindi maola, 70% → 80% amapereka 3-10x kuwonjezeka; kuphatikizika kwakukulu (> 85%) - kupindula pang'onopang'ono (85% → 95% kokha 20-50% kuwonjezeka), tack imatsika kwambiri,> 95% imataya katundu wa PSA.

Nkhaniyi ikufotokoza momwe angagwirizanitsire kutentha ndi theka la moyo wa peroxide crosslinking agents (BPO ndi DCP) ndi zenera la machiritso a tepi ya Teflon. Deta yapakati: BPO - 1-min theka la moyo pa ~ 131 ° C, 1-hr pa ~ 92 ° C, 10-hr pa ~ 72 ° C; DCP - 1-min pa ~ 171°C, 1-hr pa ~135°C, 10-hr pa ~115°C. Zolinga zofananira: zomatira zimafunikira 97-99% kuwoloka = 5-7 theka la miyoyo; kuchiritsa nthawi = 5-7 × theka la moyo pa kutentha kwa chandamale. Kubwerera kuwerengera kutentha kuchokera ku nthawi yopanga mzere wokhalamo kapena kuwerengera nthawi yochokera ku kutentha kovomerezeka.

Nkhaniyi ikufanizira kusiyana pakati pa kutentha kwa infrared radiation ndi kutentha kwa mpweya wotentha pamapangidwe ophatikizika ofanana a silicone zomatira wosanjikiza. Njira zosinthira kutentha: mpweya wotentha ndi convection-conduction, wodekha komanso wopita patsogolo, umapanga kutentha pang'ono; IR ndi mayamwidwe a radiation ndi mayamwidwe apamwamba kwambiri (ma micrometer mpaka mamilimita) kumapanga kutsetsereka kotsetsereka pamwamba kupita mkati. Zotsatira pakugawa kachulukidwe ka crosslink: mpweya wotentha umalola kuti magawo amkati ndi akunja alowemo kutentha kwanthawi yayitali nthawi imodzi, kutulutsa kachulukidwe kofanana ndi makulidwe; IR imayambitsa kusanjikiza pamwamba kuti kuchiritse khungu lowundana nthawi yomweyo lomwe limalepheretsa kutentha, zomwe zimapangitsa kuti kachulukidwe kakang'ono ka crosslink kuchepe kuchokera pamwamba mkati.

Nkhaniyi ikuyang'ana zotsatira za kugwedezeka kwa intaneti panthawi ya Teflon yotentha kwambiri ya tepi pa PTFE gawo lapansi la flatness ndi zomatira zomatira zofanana. Zotsatira pa kutsika kwapansi kwa gawo lapansi: Kukakamira kopitilira malire zotanuka kumapangitsa kuti pulasitiki ikhale yotambasuka ndi makongono osasinthika (kutalikirana kwakutali, kupendekera kopingasa), kupanga kufooka, makwinya ndi mawonekedwe a wavy; PTFE imalowa pansi pa kukanidwa kosalekeza kumakhala 'kuzizira' pambuyo pozizira, kuchititsa kusamvana pamwamba; Kukangana kosiyana kosiyana kochokera ku kusafanana kwa ma roller kumapangitsa m'mbali zopindika, matuza apakati, komanso malekezero anthawi ndi nthawi.

Nkhaniyi ikufotokoza chitsanzo cha kusintha kwa mgwirizano mphamvu ya PTFE mkulu-kutentha tepi zomatira wosanjikiza pambuyo kukalamba kutentha. Chitsanzo cha magawo atatu: Pambuyo pochiritsa kukwera siteji (kutentha koyambirira kwa kutentha kwa 200-260 ° C, magulu otsalira otsalira akupitirizabe kuphatikizika, kugwirizana kumawonjezeka kwambiri); Gawo lokhazikika lokhazikika (njira zolumikizirana zimatsirizika, mgwirizano umakhalabe wokhazikika kwa nthawi yayitali); Kuwonongeka ndi kutsika siteji (nthawi yochulukirapo / kutentha kumayambitsa kuwonongeka kwakukulu kwa unyolo, mgwirizano umachepetsa, zomatira zimafewetsa ndikukhala zovuta). Zomwe zimayambitsa kulephera kwa mgwirizano (zotsalira zamkati zong'ambika) ndi kufinya (kuzizira kochokera m'mbali chifukwa cha kuchepa kwa modulus) zimawunikidwa.

Nkhaniyi ikupereka njira zowonjezerera kukana kukwawa komanso kukhazikika kwanthawi yayitali kwa tepi ya Teflon yotentha kwambiri. Njira zikuphatikizapo: Kukhathamiritsa kwa ma molekyulu a ma netiweki - high MQ silicone resin / chingamu chiŵerengero (1.2: 1–2: 1) imapanga madera okhwima olimba; kuphatikizidwa kwa magulu a phenyl (20-30 mol%) kumalepheretsa kuyenda kwa unyolo; crosslink molecular kulemera kulamulidwa pa 5,000-15,000 g / mol; Gradient modulus multilayer zomatira dongosolo - woyamba-anangula wosanjikiza (1-3μm) ndi silane lumikiza wothandizila, mkulu-modulus cohesive wosanjikiza (30-50μm) monga kukameta ubweya zosagwira mafupa, viscoelastic zinchito wosanjikiza (3-8μm) kwa pamwamba kunyowetsa; Nanofillers - silika woyaka (10-25 wt%) wokhala ndi kusinthika kwapamtunda kumapangitsa kulumikizana kosinthika.

Nkhaniyi ikufotokoza momwe kamangidwe kake kakang'ono ka Teflon yopumira (PTFE) yotentha kwambiri imasinthira kutulutsa kwa mpweya ndi kutchinjiriza komanso zinthu zopanda ndodo. Mkangano wapakati: Kutha kwa mpweya kumafuna ma pores otseguka, pomwe kutchinjiriza kumafuna kachulukidwe komanso kusamata kumafuna malo osalala. Zolinga zopangira njira: kuwongolera m'mimba mwake (0.1-2μm, bwino <0.5μm) kuti muteteze kusungunula ndikusunga magetsi owonongeka; kuwongolera porosity pa 50-70% (≈60% mulingo woyenera) kukwaniritsa Gurley 20-100s/100cc ndi mphamvu ya dielectric ≥2kV kwa filimu ya 0.13mm; kutengera mawonekedwe apamwamba a 3D network pore (τ≈2.5-4) kupondereza njira zowongoka; kumanga asymmetric gradient pore kapangidwe ndi wandiweyani pamwamba wosanjikiza khungu (1-5μm) kwa sanali ndodo/kutsekereza ndi porous mkati kuti mpweya; gwiritsani ntchito super-oleophobic/hydrophobic surface post-treatment popanda pore blockage.

Nkhaniyi imapereka njira zothetsera zotsalira zotsalira ndi zomatira kukhetsa magazi mukamagwiritsa ntchito tepi yotentha kwambiri ya PTFE kuteteza zala zagolide za PCB panthawi ya msonkhano wa SMT. Kusanthula kwazomwe zimayambitsa: zotsalira zimachitika chifukwa cholephera kugwirizanitsa kapena kusamutsa kwapakati; kukhetsa magazi kumachitika chifukwa cha kukhuthala kwa madontho ndi zomatira kusefukira pansi pa kutenthanso. Yankho lapakati ndiloyenera kusankha tepi: silikoni PSA yokhala ndi nsonga yaifupi ≥300 ° C, mosalekeza ≥260 ° C, makulidwe okwana 0.08-0.13mm okhala ndi zigawo zoonda kwambiri zomatira, ndi chiphaso chotsutsa magazi / chotsalira. Kuwongolera njira zisanu ndi chimodzi: kuyeretsa kusanachitike ndi IPA; zero-tension lamination ndi kutulutsa mpweya wonse; wokometsedwa reflow kutentha mbiri ndi kutentha pang'ono (<2°C/s); kuzizira kozizira pansi pa 50 ° C pa ngodya ya 180 °; kukonza mwachangu mkati mwa maola 24 ndikugwiritsa ntchito kamodzi kokha; Kulephera kugwira ntchito ndi IPA kupukuta ndi kuwunika kwa 40-50x magnifier. Kwa ma PCB a mbali ziwiri, sinthani ndi tepi yatsopano musanakonzenso mbali yachiwiri.