Waqtigan xaadirka ah, waxaa jira saddex nooc oo PCB ah oo lagu dabaqay LED awood sare leh oo loogu talagalay daadinta kulaylka: guddi labajibbaaran oo naxaas ah oo caadi ah (FR4), aluminium aluminium ah oo ku saleysan guddiga xasaasiga ah ee naxaasta (MCPCB), PCB filim dabacsan oo leh koollo ku yaal guddiga aluminium aluminium.
Saamaynta kuleylka kuleylka waxay la xiriirtaa lakabka naxaasta iyo dhumucda lakabka birta iyo kuleylka kuleylka dhexdhexaadiyaha. MCPCB oo leh lakab naxaas ah oo 35um ah iyo 1.5mm aluminium aluminium ah ayaa guud ahaan la isticmaalaa. PCB dabacsan ayaa lagu dhejiyay saxan aluminium alloy ah. Dabcan, MCPCBS oo leh kuleyl heer sare ah ayaa leh waxqabadka kulaylka ugu fiican, laakiin sidoo kale qiimaha ayaa kor u kacaya.
Halkan, xogta qaar ayaa laga soo qaatay tusaale ahaan CABBIRAYNTA TC ee Shirkadda NICHIA tusaale ahaan xisaabinta. Shuruudaha waa sida soo socota: LED: 3W LED white, model MCCW022, RJC=16℃/W. Nooca heerkulbeegga dhibicda heerkulbeegga K ee cabbiraya madaxa oo lagu alxanayo weelka kulaylka.
Guddiga tijaabada PCB: guddi labajibbaaran oo naxaas ah oo dahaarka leh (40 × 40mm), t = 1.6mm, bedka lakabka naxaasta ee dusha alxanka 1180mm2, bedka lakabka naxaasta ee dhabarka 1600mm2.
Xaaladda shaqada LED: IF-500mA, VF=3.97V
TC=71℃ waxaa lagu cabiray nooca K heerkulbeeg heerkulbeeg ah. Heerkulka deegaanka TA=25℃
1. TJ waa la xisaabiyaa
TJ=RJC x PD+TC=RJC (IF x VF)+TC
TJ=16℃/W(500mA×3.97V)
+71℃=103℃
2.RBA waa la xisaabiyaa
RBA=(TC-TA)/PD
= (71℃-25℃)/1.99W
=23.1℃/W
3. RJA waa la xisaabiyaa
RJA=RJC+RBA
=16℃/W+23.1℃W
=39.1℃W
Haddii TJmax nashqadeeyay uu yahay -90℃, TJ-ga loo xisaabiyay si waafaqsan shuruudaha kore ma buuxin karo shuruudaha naqshadeynta. Waa lagama maarmaan in la beddelo PCB-ga kulaylka wanaagsan ama la kordhiyo aagga kulaylka, oo tijaabi oo xisaabi mar labaad ilaa TJ≤TJmax.
Habka kale ayaa ah in marka qiimaha UC ee LED uu aad u weyn yahay, VF = 3.65V marka RJC = 9 ℃ / WIF = 500mA la beddelo, xaaladaha kale ayaa weli ah kuwo aan isbeddelin, T) waxaa loo xisaabin karaa sida:
TJ = 9 ℃ / W + 71 ℃ (500 ma * 3.65 V) = 87.4 ℃
Waxaa jira xoogaa khalad ah xisaabinta 71 ℃ ee kor ku xusan, 9 ℃W LED cusub waa in la alxamaa si dib loogu tijaabiyo TC (qiimaha la qiyaasay wax yar ayuu ka yar yahay 71℃). Runtii dhib ma laha. Ka dib markii la isticmaalo 9 ℃ / W LED, looma baahna in la beddelo walxaha PCB iyo aagga, kaas oo buuxiya shuruudaha naqshadeynta.
Kuleyl kuleyl oo ku yaal dhabarka PCB
Haddii TJmax-ka la xisaabiyay uu aad uga weyn yahay shuruudaha naqshadeynta, oo qaab-dhismeedku aanu ogolayn aag dheeri ah, tixgeli inaad PCB-ga dib ugu dhejiso "U" profile aluminium qaabaysan (ama saxan aluminium ah), ama ku dheji saxanka kulaylka. Labadan hab ayaa caadi ahaan loo isticmaalaa naqshadaynta nalalka LED-yada ee awoodda badan. Tusaale ahaan, tusaale ahaan xisaabinta sare, weelka kulaylka 10 ℃/W ayaa lagu dhejiyay dhabarka PCB oo leh TJ=103 ℃, TJ-geeduna wuxuu hoos ugu dhacayaa qiyaastii 80 ℃.
Waa in la ogaadaa in TC-da sare lagu cabbiro heerkulka qolka (guud ahaan 15 ~ 30 ℃). Haddii heerkulka deegaanka ee nalka LED TA uu ka weyn yahay heerkulka qolka, TJ-ga dhabta ah wuxuu ka sarreeyaa TJ-ga la xisaabiyay ee heerkulka qolka, markaa qodobkan waa in lagu tixgeliyaa naqshadeynta. Haddii baaritaanka lagu sameeyo heerkulbeegga, waxaa fiican in heerkulka la beddelo heerkulka ugu sarreeya marka la isticmaalayo.
Intaa waxaa dheer, haddii PCB lagu rakibay si toos ah ama toosan, xaaladaheeda kuleylku way kala duwan yihiin, taas oo saameyn gaar ah ku leh cabbirka TC. Qalabka qolofka, cabbirka iyo daloolka kuleylka kulaylka ee nalka ayaa sidoo kale saameyn ku leh kuleylka kuleylka. Sidaa darteed, waa in ay jiraan xoogaa dabacsanaan ah oo naqshadeynta ah.
Waqtiga boostada: Mar-23-2022
