Parizvino, kune marudzi matatu ePCB akaiswa ne-high-simba LED yekupisa kupisa: yakajairwa kaviri-sided copper coated board (FR4), aluminium alloy based sensitive copper board (MCCBB), inochinjika firimu PCB ine adhesive paaluminium alloy board.
Iyo yekupisa yekupisa mhedzisiro inoenderana nemhangura layer uye ukobvu hwesimbi simbi uye thermal conductivity ye insulating medium. MCPCB ine 35um copper layer uye 1.5mm aruminiyamu alloy inowanzoshandiswa. Flexible PCB inonamirwa kune aluminium alloy plate. Ehe, MCPCBS ine yakakwira yekupisa conductivity ine yakanakisa kupisa kwekuita, asi mutengo uri kukwira zvakare.
Pano, mamwe data anotorwa kubva kumuenzaniso weKUYERA TC yeNICHIA Kambani semuenzaniso wekuverenga. Mamiriro acho ndeaya: LED: 3W chena LED, modhi MCCW022, RJC = 16 ℃/W. Type K thermocouple point thermometer yekuyeresa musoro wakasundirwa kunyura yekupisa.
PCB test board: kaviri-layer mhangura yakanamwa bhodhi (40 × 40mm), t = 1.6mm, mhangura layer yenzvimbo yewelding pamusoro 1180mm2, nzvimbo yemhangura yekumashure 1600mm2.
Chimiro chekushanda kwe LED: IF-500mA, VF = 3.97V
TC = 71 ℃ yakayerwa nerudzi rweK thermocouple point thermometer. The ambient tembiricha TA=25℃
1. TJ inoverengwa
TJ=RJC x PD+TC=RJC (IF x VF)+TC
TJ=16℃/W(500mA×3.97V)
+71℃=103℃
2.RBA inoverengwa
RBA=(TC-TA)/PD
=(71℃-25℃)/1.99W
=23.1℃/W
3. RJA inoverengwa
RJA=RJC+RBA
=16℃/W+23.1℃W
=39.1℃W
Kana iyo yakagadzirwa TJmax iri -90 ℃, TJ yakaverengerwa maererano nemamiriro ari pamusoro haigone kuzadzisa zvinodiwa zvekugadzira. Izvo zvinodiwa kuti uchinje PCB nekupisa kupisa kuri nani kana kuwedzera nzvimbo yayo yekupisa kupisa, uye kuyedza uye kuverenga zvakare kusvika TJ≤TJmax.
Imwe nzira ndeyokuti kana UC kukosha kwe LED kwakanyanyisa, VF = 3.65V apo RJC = 9 ℃ / WIF = 500mA inotsiviwa, mamwe mamiriro ezvinhu anoramba asina kuchinja, T) inogona kuverengwa se:
TJ = 9 ℃ / W + 71 ℃ (500 ma * 3.65 V) = 87.4 ℃
Pane chimwe chikanganiso mukuverenga kwe71 ℃ pamusoro, itsva 9 ℃W LED inofanirwa kuiswa welded kuti iedzezve TC (iyo yakayerwa kukosha idiki zvishoma pane 71 ℃). Hazvina basa. Mushure mekushandisa 9 ℃/W LED, haidi kushandura PCB zvinhu nenzvimbo, inosangana nezvinodiwa zvekugadzira.
Kupisa kunyura kumashure kwePCB
Kana iyo yakaverengerwa TJmax yakakura kwazvo kupfuura dhizaini inodiwa, uye chimiro hachibvumire imwe nzvimbo, funga kunamatira PCB kumashure ku "U" yakaumbwa nearuminiyamu mbiri (kana aluminium plate stamping), kana kunamatira kune inopisa singi. Idzi nzira mbiri dzinowanzo shandiswa mukugadzirwa kwemarambi akawanda emagetsi e LED. Semuenzaniso, mumuenzaniso wekuverenga uri pamusoro, 10 ℃/W kupisa sink inonamirwa kuseri kwePCB ine TJ=103 ℃, uye TJ yayo inodonha kusvika pa80 ℃.
Zvinofanira kucherechedzwa pano kuti TC iri pamusoro inoyerwa pakamuri tembiricha (kazhinji 15 ~ 30 ℃). Kana iyo ambient tembiricha yemwenje we LED yakakura pane tembiricha yekamuri, iyo TJ chaiyo yakakwirira kupfuura yakaverengerwa TJ yakayerwa pakamuri tembiricha, saka chinhu ichi chinofanira kutariswa mukugadzira. Kana bvunzo ikaitwa mu thermostat, zviri nani kugadzirisa tembiricha kusvika kune yakanyanya ambient tembiricha kana ichishandiswa.
Pamusoro pezvo, ingave PCB yakaiswa yakachinjika kana yakatwasuka, mamiriro ayo ekupisa kupisa akasiyana, ayo ane chimwe chinokanganisa pachiyero cheTC. Iyo shell zvinhu, saizi uye kupisa kupisa gomba remwenje zvakare zvine chekuita nekupisa kupisa. Nokudaro, panofanira kuva nekusununguka mukugadzira.
Nguva yekutumira: Mar-23-2022
