Okwangoku, kukho iintlobo ezintathu zePCB esetyenziswa ngamandla aphezulu e-LED yokutshatyalaliswa kobushushu: ibhodi eqhelekileyo enamacala amabini yobhedu (FR4), ibhodi yobhedu e-aluminiyam esekelwe kubuthathaka (MCPCB), ifilimu eguquguqukayo yePCB encamathelayo kwibhodi yealluminiyam.
Impembelelo yokutshatyalaliswa kobushushu ihambelana nomgangatho wobhedu kunye nobukhulu bomgangatho wetsimbi kunye ne-thermal conductivity ye-insulating medium. I-MCPCB ene-35um yobhedu kunye ne-1.5mm ye-aluminium alloy isetyenziswa ngokubanzi. I-PCB eguquguqukayo incanyathiselwe kwipleyiti yealluminiyam. Ewe kunjalo, i-MCPCBS ene-thermal conductivity ephezulu ineyona ntsebenzo ingcono ye-thermal, kodwa ixabiso liyenyuka.
Apha, ezinye iinkcukacha zithathwe kumzekelo we-MEASURING TC yeNkampani ye-NICHIA njengemizekelo yokubala. Iimeko zezi zilandelayo: I-LED:3W i-LED emhlophe, imodeli MCCW022, RJC=16℃/W. Chwetheza i-K thermocouple point thermometer yokulinganisa intloko edityaniswe kwisinki yobushushu.
Ibhodi yovavanyo ye-PCB: ibhodi yobhedu ephindwe kabini (40 × 40mm), t = 1.6mm, indawo yobhedu ye-welding surface 1180mm2, indawo yobhedu yomqolo we-1600mm2.
Ubume bokusebenza be-LED: IF-500mA, VF = 3.97V
I-TC=71℃ ilinganiswe ngohlobo lwethemomitha yohlobo lwe-K thermocouple point. Ubushushu be-ambient TA=25℃
1. I-TJ ibalwa
TJ=RJC x PD+TC=RJC (IF x VF)+TC
TJ=16℃/W(500mA×3.97V)
+71℃=103℃
I-2.RBA ibalwa
RBA=(TC-TA)/PD
=(71℃-25℃)/1.99W
=23.1℃/W
3. I-RJA ibalwa
RJA=RJC+RBA
=16℃/W+23.1℃W
=39.1℃W
Ukuba i-TJmax eyiliweyo yi -90℃, i-TJ ibalwa ngokwemiqathango engentla ayikwazi ukuhlangabezana neemfuno zoyilo. Kuyimfuneko ukuba utshintshe i-PCB ngokutshatyalaliswa kobushushu obungcono okanye ukwandisa indawo yokutshatyalaliswa kobushushu, kwaye uvavanye kwaye ubale kwakhona kude kube yi-TJ≤TJmax.
Enye indlela kukuba xa ixabiso le-UC le-LED likhulu kakhulu, i-VF = 3.65V xa i-RJC = 9 ℃ / WIF = 500mA ithathelwa indawo, ezinye iimeko zihlala zingatshintshi, T) ingabalwa njenge:
TJ = 9 ℃ / W + 71 ℃ (500 ma * 3.65 V) = 87.4 ℃
Kukho impazamo ethile ekubaleni i-71℃ apha ngasentla, i-9℃W entsha ye-LED kufuneka idityaniswe ukuze iphinde ivavanye i-TC(ixabiso elilinganisiweyo lincinci kancinane kune-71℃). Ayinamsebenzi ncam. Emva kokusebenzisa i-9 ℃ / W LED, ayifuni ukutshintsha izinto zePCB kunye nommandla, ohlangabezana neemfuno zoyilo.
Isinki yobushushu ngasemva kwePCB
Ukuba i-TJmax ebalwayo inkulu kakhulu kunemfuneko yoyilo, kwaye isakhiwo asivumeli indawo eyongezelelweyo, cinga ukunamathela kwi-PCB emva kwe-"U" iprofayili ye-aluminium emile (okanye i-aluminium plate stamping), okanye ibambelele kwi-sink yokushisa. Ezi ndlela zimbini zisetyenziswa ngokuqhelekileyo kuyilo lwezibane ze-LED ezininzi zamandla aphezulu. Umzekelo, kulo mzekelo ubalo ungentla, i-10℃/W isinki yobushushu incamatheliswe ngasemva kwe-PCB nge-TJ=103℃, kwaye i-TJ yayo yehla ukuya malunga ne-80℃.
Kufuneka kuqatshelwe apha ukuba i-TC ingentla ilinganiswa kwiqondo lobushushu begumbi (ngokubanzi 15 ~ 30 ℃). Ukuba ubushushu be-ambient yesibane se-LED sesibane esikhulu kuneqondo lokushisa kwegumbi, i-TJ yangempela iphezulu kune-TJ ebalwayo elinganiswe kwiqondo lokushisa, ngoko le nto kufuneka ithathelwe ingqalelo kuyilo. Ukuba uvavanyo lwenziwa kwi-thermostat, kungcono ukulungisa iqondo lobushushu kwiqondo eliphezulu lobushushu xa lisetyenziswa.
Ukongeza, nokuba i-PCB ifakwe ngokuthe tye okanye ngokuthe nkqo, iimeko zayo zokutshatyalaliswa kobushushu ziyahluka, ezinempembelelo ethile kumlinganiselo we-TC. Izinto zegobolondo, ubungakanani kunye nomngxuma wokutshatyalaliswa kobushushu besibane nazo zinefuthe ekutshitshisweni kobushushu. Ngoko ke, kufuneka kubekho ikhefu kuyilo.
Ixesha lokuposa: Mar-23-2022
