LED????????

1
LED????????

• ???????
• ? ?

2
??

• LED??????????????????????????????????????????LE
  D?????????????,????????????,?????????????????????
  ?????????????, ??????????,?????????????????????

3
??????
LED???????????LED?????,??????LED??PN?????
????????????????????????
4
Thermal Resisitance Thermal Impedance
5
???????

• ????????????????????????????????????,?????????????
  ??
• ??????????????????,???????????????????????????????
  ??

6
?-????

• ? LED?????????
• ???
• ?????????????
• ??????
• ? ????????????
• ???????
• ? ?????????,??
• ??????

??????
?????????
?????????
7
?-????
? LED????? ??????? ????,????
1??????? ????????? ?????????
?????????????????????? ???
8
NC-100 Natural Convection Chamber
????(????)??????
9
????(????)????

• ? ????????(??)??????/??(?JA)
• ?????/??(?JHS)??????
• ? ?????1 ft3,?????????????????????,?????????,?????
  ?????????????,??????????????????????????
  ?????????,??????????????????????????T????????????

10
????????
???????????????/? ???????????????? ????????? ???
????????????? ???????????
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WT-100 Wind Tunnel
???????(????)?? ??/????(?JMA)??
?/???????? ?????????????? ????????0.5m/s
5m/s????? ??????20.3x20.3cm2 ? ? T????????????
????
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LED????
LED PN?????????????????????? PN?????????(??)
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LED????

• ??????????-??????(thermal path)??????????

?????????????????????
????,?????????????
?????????????????????
????
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??LED??
??LED???????????????????.
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LED?????????
???????,PN???????????????? ????K???--??????,??
????1,???IM,??????VFi? ????2,????????IH,??
????VH ????1,?????IM,???? ??VFf?
? ?VF VFi-- VFf ?Ti K ?VF TJTJi
?Ti ??TJi??????LED?? ??????
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LED???????????
????????????0.1,1.0,5.0,10.0???,???????????
17
??????
18
???????????
?????????????,??????,???????????????,?????????????
???????????????????????????
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??????
????????????? ??????????? (Tlow)??,??????
Vlow? ?????????(Thigh), ?????Vhigh????
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TCS-100 Temperature Calibration System
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TCS-100 Temperature Calibration System

• ? The TCS-100 is designed to simplify the
  gathering of data for K Factor calibration of
  diodes.
• ? The system contains a precision current source
  for supplying IM, a voltmeter for measuring VM,
  and a Type-T thermocouple measurement for
  monitoring the environment temperature.
• ? A 36-pin rear-panel mounted connector provides
  full Kelvin connection for up to 16 devices. Each
  device under test is selected by front-panel push
  button.

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(No Transcript)
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????
???????????????????? ?,??????????????????

• ???LED???,???????????,???
• ???????????????????????
• ???????????????????????
• ???????1-??ms???????LED??
• ??????,?????????????????

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Agilent ?????
25
????
???? ?????????,?????????PH?,????????????.
??? ?? ???? ? ??
???????? ??
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??????

• ??????????????????
• ?????????,?????????
• ????????????,???????PH,tH???????
• ???????????????????????????????
• ???????????????????????????

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LED????????

• A.??????
• ??????????????????
• (1) ????,LED?????????,??????
• ?????????????
• (2) LED???????????????????,?
• ??????????????????????
• (3)???LED???????,???????

?? ????(ºC) ?? ????(ºC)
LED?? 120 ??PCB LED 105
???LED -40--105 ???LED -40--75
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LED????????

• B.????????
• ?????????????????
• ??????TA
• C.?????????
• ???LED??120 ºC/W,TA70 ºC.
• ????????.
• ?PD(125 ºC-70 ºC)/ 120 ºC/W0.71W.

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????(??)
30
????(??)

• The term exposed surface area is the sum total of
  all surfaces of the heat sink exposed to
  convection. The "footprint area quantifies the
  projected area of the heat sink as shown in
  following diagram.
• A finned heat sink can fit more exposed surface
  area in a given foot print than a flat heat sink.

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????(??)
Flat Heat Sink 0.09" (2.3 mm) Thick
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??????

• ??LED LA E67B, IF50mA,Tjlt125?C,????????TS70
  ?CUF2.1V,?????????130 ?C/W.????
• ? Tj 130 ?C/W 50mA2.1V70 ?C
• 83.7 ?C
• Tjltmax Tjlt 125?C

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????
5x Magnification of an Infrared Image of a biased
AH101 at a case temperature near 85 C
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LED?????

• LED?? LED (??)??(??)???????(??)??(?
• ?)???.
• PP0 exp(-ßt) . (1)
• ßß0IFexp (-Ea/kTj). (2)
• Tj?th IFVFTa .. (3)
• ????(1)??????????????,??????
• ??????????.??,?DC50mA????300??
• ??,?????300????????.
• ???(1)(2)(3)?????LED?????????? .

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MTTF???

• ??????? MTTF A e(Ea/kT)
• A 3.71 x 10-12 (hrs) (Pre-exponential
• Factor)
• Ea 1.5 (eV) (Activation Energy for WJ
• GaAs devices) (???)
• k 8.617 x 10-5 (eV/ºC) (Boltzmanns
• Constant)

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MTTF???
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???

• ????????????????????????
• ?????????????????????
• ??????LED??,??????????
• ????LED????,????????????????????????,???????,?????
  ?????????
• ????,???????,?????.