Hona joale, ho na le mefuta e meraro ea PCB e sebelisoang ka matla a phahameng a LED bakeng sa ho qhala mocheso: boto e tloaelehileng ea koporo e nang le mahlakoreng a mabeli (FR4), alloy alloy based copper board (MCPCB), flexible film PCB e nang le sekhomaretsi holim'a boto ea motsoako oa aluminium.
Phello ea ho senya mocheso e amana le lera la koporo le botenya ba lera la tšepe le mocheso oa mocheso oa mochine o sireletsang.MCPCB e nang le lera la koporo la 35um le alloy ea aluminium ea 1.5mm hangata e sebelisoa.Flexible PCB e khomaretsoe ho poleiti ea motsoako oa aluminium.Ha e le hantle, MCPCBS e nang le mocheso o phahameng oa mocheso o na le ts'ebetso e ntle ka ho fetisisa ea mocheso, empa theko e ntse e phahama.
Mona, lintlha tse ling li nkuoe mohlaleng oa MEASURING TC ea Khamphani ea NICHIA e le mehlala ea lipalo.Maemo ke a latelang: LED:3W LED e tšoeu, ea mohlala MCCW022, RJC=16℃/W.Hlooho e lekanyang ea ntlha ea thermocouple ea K e cheselitsoeng ho teba ha mocheso.
Boto ea teko ea PCB: boto e entsoeng ka koporo e habeli (40 × 40mm), t = 1.6mm, sebaka sa koporo sa sebaka sa welding 1180mm2, sebaka sa koporo sa mokokotlo oa 1600mm2.
Boemo ba ho sebetsa ba LED: IF-500mA, VF = 3.97V
TC=71℃ e lekantsoe ka mofuta oa K thermocouple point thermometer.Thempereichara ea tikoloho TA=25℃
1. TJ e baloa
TJ=RJC x PD+TC=RJC (IF x VF)+TC
TJ=16℃/W(500mA×3.97V)
+71℃=103℃
2.RBA e baloa
RBA=(TC-TA)/PD
=(71℃-25℃)/1.99W
=23.1℃/W
3. RJA e baloa
RJA=RJC+RBA
=16℃/W+23.1℃W
=39.1℃W
Haeba TJmax e entsoeng e le -90℃, TJ e baloang ho latela maemo a ka holimo e ke ke ea finyella litlhoko tsa moralo.Hoa hlokahala ho fetola PCB ka mocheso o ntlafetseng oa mocheso kapa ho eketsa sebaka sa eona sa ho senya mocheso, le ho hlahloba le ho bala hape ho fihlela TJ≤TJmax.
Mokhoa o mong ke hore ha boleng ba UC ba LED bo le boholo haholo, VF = 3.65V ha RJC=9℃/WIF=500mA e nkeloa sebaka, maemo a mang a lula a sa fetohe, T) a ka baloa joalo ka:
TJ = 9 ℃ / W + 71 ℃ (500 ma * 3.65 V) = 87.4 ℃
Ho na le phoso e itseng palong ea 71 ℃ ka holimo, 9 ℃W LED e ncha e lokela ho chesetsoa ho hlahloba TC hape (theko e lekantsoeng e nyane ho feta 71 ℃).Ha ho na taba.Ka mor'a ho sebelisa 9 ℃/W LED, ha e hloke ho fetola thepa le sebaka sa PCB, se finyellang litlhoko tsa moralo.
Sekepe sa mocheso ka morao ho PCB
Haeba TJmax e baloang e le kholoanyane ho feta tlhokahalo ea moralo, 'me mohaho o sa lumelle sebaka se eketsehileng, nahana ka ho khomarela PCB ho khutlela "U" e entsoeng ka aluminium profil (kapa aluminium plate stamping), kapa ho khomarela mocheso oa mocheso.Mekhoa ena e 'meli e atisa ho sebelisoa ha ho etsoa mabone a LED a matla a mangata.Mohlala, mohlaleng o ka holimo oa lipalo, sinki ea mocheso ea 10℃/W e manehiloe ka morao ho PCB ka TJ=103℃, 'me TJ ea eona e theohela ho hoo e ka bang 80℃.
Hoa lokela ho hlokomeloa mona hore TC e ka holimo e lekanngoa mocheso oa kamore (ka kakaretso 15 ~ 30 ℃).Haeba mocheso o teng oa lebone la LED la TA o moholo ho feta mocheso oa kamore, TJ ea sebele e phahame ho feta TJ e baloang e lekantsoeng mocheso oa kamore, kahoo ntlha ena e lokela ho nkoa ka moralo.Haeba tlhahlobo e etsoa ka thermostat, ho molemo ho fetola mocheso ho mocheso o phahameng ka ho fetisisa oa tikoloho ha o sebelisoa.
Ho phaella moo, hore na PCB e kenngoa ka holimo kapa ka holimo, maemo a eona a ho senya mocheso a fapane, a nang le tšusumetso e itseng ho lekanya TC.Thepa ea khetla, boholo le lesoba la ho qhala mocheso la lebone le tsona li na le phello ea ho senya mocheso.Ka hona, ho lokela ho ba le bolokolohi bo itseng moqapong.
Nako ea poso: Mar-23-2022