CN103076551B - A kind of LED lamp thermal resistance forms proving installation and method - Google Patents
A kind of LED lamp thermal resistance forms proving installation and method Download PDFInfo
- Publication number
- CN103076551B CN103076551B CN201310000861.5A CN201310000861A CN103076551B CN 103076551 B CN103076551 B CN 103076551B CN 201310000861 A CN201310000861 A CN 201310000861A CN 103076551 B CN103076551 B CN 103076551B
- Authority
- CN
- China
- Prior art keywords
- led
- thermometric
- led lamp
- led unit
- thermal resistance
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
- 238000000034 method Methods 0.000 title claims abstract description 15
- 238000009434 installation Methods 0.000 title abstract description 4
- 238000005259 measurement Methods 0.000 claims abstract description 9
- 238000007537 lampworking Methods 0.000 claims description 13
- 238000012360 testing method Methods 0.000 claims description 5
- 238000013461 design Methods 0.000 abstract description 9
- 238000010438 heat treatment Methods 0.000 abstract description 8
- 239000004065 semiconductor Substances 0.000 abstract description 4
- 230000001052 transient effect Effects 0.000 abstract description 3
- 230000001066 destructive effect Effects 0.000 abstract description 2
- 230000017525 heat dissipation Effects 0.000 abstract description 2
- 238000010586 diagram Methods 0.000 description 4
- 238000005516 engineering process Methods 0.000 description 4
- 241000168254 Siro Species 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000009699 differential effect Effects 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 238000005286 illumination Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
- 239000000523 sample Substances 0.000 description 1
- 229910000679 solder Inorganic materials 0.000 description 1
- 238000009987 spinning Methods 0.000 description 1
Landscapes
- Led Devices (AREA)
- Testing Of Individual Semiconductor Devices (AREA)
Abstract
A kind of LED lamp thermal resistance forms proving installation and method belongs to semi-conductor LED illuminating and shows reliability design and examination technical field.Primary object of the present invention is: in actual LED lamp, choose, isolated part LED is as temperature element, devise the synchro switch mode and device that control outside lamp power, utilize collection circuit and the method for transient temperature rise conditional curve, the thermal resistance of the actual LED lamp of on-line measurement is formed.When the heating radiator that LED lamp is practical different, or heating radiator and LED component loose contact, the thermal resistance of its each several part is just different, formed by the thermal resistance measured under different designs and equipment, the heat dissipation design of LED lamp can be optimized, reduce the maximum junction temperature of light fixture, ensure LED lamp serviceable life and quality.The method and apparatus that this invention is mainly used in fast, non-destructive determination LED lamp thermal resistance is formed.
Description
Technical field:
This technology belongs to semi-conductor LED illuminating and display reliability design and examines technical field.The method and apparatus that this invention is mainly used in fast, non-destructive determination LED lamp thermal resistance is formed.
Background technology:
Semiconductor LED illuminating lamp tool or display panel use the power led device of some as light source, can produce a large amount of heat, cause the temperature at semiconductor PN place to raise, hydraulic performance decline during its work.General employing heat sink or increase heat abstractor etc., export to external environment condition by heat by LED chip concentrated area, ensure that junction temperature is lower than safe temperature, guarantees the quality of whole light fixture.
But can only measure the thermal resistance of single led chip in prior art, and cannot measure the thermal resistance after composition light fixture, conventional method just measures the temperature of its surface by the temperature probe on LED lamp surface.This is extremely not convenient to actual LED lamp design and devdlop.The present invention utilizes and gathers LED chip transient temperature rise conditional curve technology, convenient, nondestructively can obtain the information that LED lamp thermal resistance is formed, be optimal design LED lamp heat abstractor, improve heat dispersion, have obvious advance.
Summary of the invention:
Primary object of the present invention is: in actual LED lamp, choose, isolated part LED is as temperature element, devise the synchro switch mode and device that control outside lamp power, utilize collection circuit and the method for transient temperature rise conditional curve, the thermal resistance of the actual LED lamp of on-line measurement is formed.
LED lamp thermal resistance forms tester device, it is characterized in that:
This device comprises: have tested LED lamp working power switch 200 that tester 100, the tested person instrument 100 that can measure LED chip temperature rise and thermal resistance control, LED lamp power supply 201, thermometric LED unit assembly 301 and tested LED lamp 300;
Tester 100 comprises computing machine 101, capture card 102, thermometric LED unit measuring current source 103, computer-controlled thermometric LED unit component operation power switch 104, thermometric LED unit component operation power supply 105 and thermometric LED unit voltage and current collecting unit 106;
Wherein the relation of thermometric LED unit assembly 301 and tested LED lamp 300 is as follows; LED connected mode some LED strip connection before this in light fixture, the LED access power supply in parallel again of then multiple series connection; From multi-path parallel LEDs, isolating a channel Temperature Measuring LED unit assembly 301, remaining LED is tested LED lamp 300; Thermal resistance on the channel Temperature Measuring LED unit assembly 301 isolated, its environment temperature distribution situation is consistent with in actual LED lamp work, just represents whole light fixture thermal resistance;
Thermometric LED unit assembly 301 is connected respectively to the LED chip working current source 104 in tester 100, thermometric LED unit measuring current source 103, capture card 102 and voltage and current collecting unit 106, tested LED lamp 300 is connected to tested LED lamp working power switch 200, lamp power 201 connects 200, tested LED chip power supply 105 is connected 104, and tested LED lamp working power switch 200 and LED chip working current source 104 are connected to computing machine 101; Computing machine 101 connects capture card 102/ thermometric LED unit measuring current source 103 and voltage and current collecting unit 106.
Application said apparatus carries out the method for testing of LED lamp thermal resistance, it is characterized in that:
During measurement, the thermometric LED unit assembly 301 LED lamp isolated is linked into the thermometric LED unit component operation power switch 104 in tester 100 respectively, thermometric LED unit measuring current source 103, capture card 102 and voltage and current collecting unit 106, tested LED lamp 300 is accessed tested LED lamp working power switch 200, and link LED lamp power supply 201, thermometric LED unit component operation power supply 105 is accessed thermometric LED unit component operation power switch 104, LED lamp power switch 200 and thermometric LED unit component operation power switch 104 access computing machine 101, synchronously control by computing machine,
Start after process of measurement, computing machine 101 sends instruction and thermometric LED unit measuring current source 103 is loaded into thermometric LED unit assembly 301 always, through capture card 102, collects the thermometric LED unit assembly 301 both end voltage V now do not applied under working current
0;
Then, computing machine sends instruction and thermometric LED unit component operation power supply 105 is loaded into thermometric LED unit assembly 301 through thermometric LED unit component operation power switch 104, LED lamp power supply 201 is loaded into tested LED lamp 300 through tested LED lamp working power switch 200 simultaneously; The computing machine voltage and current collecting unit 106 that sends instructions collects operating voltage and the electric current of thermometric LED unit assembly 301, and calculates the operating power P=VI gathering thermometric LED unit assembly 301;
Treat that tested LED lamp 300 temperature no longer changes and reach stable state, computing machine 101 sends instruction, turn off thermometric LED unit component operation power supply 105 and lamp power 201, and the voltage that triggering collection card 102 gathers on tested LED unit assembly 301 changes V (t) in time simultaneously;
The temperature coefficient of thermometric LED unit assembly 301 is α, LED unit assembly 301 temperature rise change Delta T (t) in time=[V (t)-V
0]/α, the power P=VI loaded when thermometric LED unit assembly 301 works, tester calculates Δ T (t) curve, show that the thermal resistance of LED unit assembly 301 i.e. the thermal resistance of tested LED lamp 300 are formed.
Structure function method process is adopted to Fig. 2 temperature rise and the conditional curve of heat time, as the algorithm process in U.S. equipment thermal resistance tester Phase 11, obtains thermal resistance schematic diagram corresponding to fitting structure, see Fig. 3.
LED lamp is generally main comprises packaged LED and heating radiator, compact siro spinning technology therebetween.The thermal source of light fixture is LED chip, and namely PN junction place produces heat.In atmospheric environment, main heat sink approach is that heat is delivered to packaged LED outside through solder, shell, by passing to heating radiator behind the contact gap of shell and spreader surface, is finally delivered to ambient external environment.
Shown in Fig. 3, the space thermal resistance that the physical arrangement of LED lamp sinking path and differential structrue functional arrangement reflect is formed can one_to_one corresponding.In structure function figure, the first peak value horizontal ordinate is that LED chip is to case thermal resistance value, second peak value horizontal ordinate is that chip arrives spreader surface thermal resistance value, the difference of two peak values is the thermal contact resistance value between shell to spreader surface, 3rd peak value horizontal ordinate is the thermal resistance value of chip to external environment conditions such as air, and the difference of second and third peak value is heat radiator thermal resistance value.
In figure, y-axis represents the differential action of electric capacity, in the x-axis that its peak value is corresponding, value represents the thermal resistance value of different materials, the curve of the rightmost side represents the thermal resistance that LED lamp is total, and the value in the x-axis that leftmost peak value is corresponding represents the thermal resistance of chip, and the difference between all the other peak values represents the thermal resistance of diverse location;
Primary object:
1, devise by the circuit of actual LED lamp extraction thermometric LED unit assembly as temperature element;
2, design and Implement the LED lamp simultaneous switching circuit with thermometric LED unit assembly, ensure that the thermal resistance measuring actual LED lamp is formed;
3, LED one single chip thermal resistance measurement function is extended.
Accompanying drawing explanation
Fig. 1 is that LED lamp thermal resistance forms proving installation schematic diagram.
Wherein-101: computing machine; 102: capture card; 103: thermometric LED unit measuring current source; 104: thermometric LED unit component operation power switch; 105: thermometric LED unit component operation power supply; 106: thermometric LED unit voltage and current collecting unit; 200: tested LED lamp working power switch; 201:LED lamp power;
301: thermometric LED unit assembly; 300: tested LED lamp.
Fig. 2 is the conditional curve figure of temperature rise and heat time.
Fig. 3 is thermal resistance schematic diagram corresponding to fitting structure.
Fig. 4 is thermal resistance schematic diagram corresponding to fitting structure in embodiment.
Embodiment:
Select the LED down that Zhuhai Shengyuan Tongtai Electronics Co., Ltd. produces, use this patent to test its LED chip and form to the thermal resistance of heating radiator.This fitting structure is in parallel after some high-power LED chips are first connected, and LED chip shell directly coheres in spreader surface, and radiating mode is heat pipe for thermal conductivity.Before test, first be fixed in a confined space by unsettled for tested light fixture 300, select and be separated wherein one group of thermometric LED unit assembly 301 and be connected with thermometric LED unit component operation power switch 104 interface separately as by temperature measuring device, formed by the thermal resistance of measurement thermometric LED unit assembly 301 to heating radiator, reach the object obtaining heat radiator thermal resistance size, all the other LED are connected and are connected with tested LED lamp working power switch 200.During test, first send instruction by computer for controlling 101, small area analysis is connected thermometric LED unit assembly 301 by thermometric LED unit measuring current source 103 interface, and capture card 102 gathers the undressed junction voltage V making thermometric LED unit assembly 301 under electric current
0.Then 101 instruction is sent, by thermometric LED unit component operation power supply 105 and thermometric LED unit component operation power switch 104, access thermometric LED unit assembly 301, and synchro control 200 connects LED lamp power supply 201, light fixture 300 is made to be in illumination work state, thermometric LED unit voltage and current collecting unit 106 gathers voltage V and the electric current I of thermometric LED unit assembly 301, obtains power P=VI; When temperature reaches stable state, computing machine 101 sends instruction, turns off the LED lamp power supply 201 of thermometric LED unit assembly 301 thermometric LED unit component operation power supply 105 and tested LED lamp 300 simultaneously, starts capture card 102, gather on thermometric LED unit assembly 301 under little measuring current, junction voltage V
jt () temperature-fall period curve in time, until V
jt () no longer changes, reach new stable state.Now (V (t)-V
0)/α is exactly LED lamp temperature change procedure curve in time; Again divided by power P, be thermal resistance R
th=(V (t)-V
0)/α P, can obtain the cooling response curve of thermometric LED unit assembly 301 thus, implements the structure function processing capacity in thermal resistance tester to its curve, namely obtains from thermal source LED chip to the thermal resistance of light fixture external environment condition formation curve.
Measurement result as shown in Figure 3.As can be seen from the figure R
1=0.8K/W is that on tested light fixture thermometric LED unit assembly 301, LED ties shell thermal resistance, R
2=2.3K/W is for tying spreader surface thermal resistance, R
1with R
2difference 1.5K/W be thermal contact resistance between LED shell to spreader surface, R
3=4.97K/W is for tying air thermal resistance, R
2with R
3difference 2.67K/W be heat radiator thermal resistance, this model light fixture is heat pipe heat radiation mode, and therefore heat radiator thermal resistance value is less.If environment temperature is T in addition
0, when this light fixture is operated in stable state, LED junction temperature is R
3* P+ T
0.
When the heating radiator that LED lamp is practical different, or heating radiator and LED component loose contact, the thermal resistance of its each several part is just different, formed by the thermal resistance measured under different designs and equipment, the heat dissipation design of LED lamp can be optimized, reduce the maximum junction temperature of light fixture, ensure LED lamp serviceable life and quality.
Claims (1)
1. apply LED lamp thermal resistance and form the method for testing that tester device carries out LED lamp thermal resistance,
This device comprises: for measuring the tester of LED lamp temperature rise and thermal resistance, the tested LED lamp working power switch of tested person instrument control, LED lamp power supply, thermometric LED unit assembly and tested LED lamp;
Tester comprises computing machine, capture card, thermometric LED unit measuring current source, computer-controlled thermometric LED unit component operation power switch, thermometric LED unit component operation power supply and thermometric LED unit voltage and current collecting unit;
Wherein the relation of thermometric LED unit assembly and tested LED lamp is as follows; LED connected mode some LED strip connection before this in light fixture, the LED access power supply in parallel again of then multiple series connection; From multi-path parallel LEDs, isolate a channel Temperature Measuring LED unit assembly, remaining LED is tested LED lamp; Thermal resistance on the channel Temperature Measuring LED unit assembly isolated, its environment temperature distribution situation is consistent with in actual LED lamp work, just represents whole light fixture thermal resistance;
Thermometric LED unit assembly is connected respectively to thermometric LED unit component operation power switch, thermometric LED unit measuring current source, capture card and voltage and current collecting unit, tested LED lamp is connected to tested LED lamp working power switch, lamp power connects power source switch for lamp set, thermometric LED unit component operation power supply is connected thermometric LED unit component operation power switch, tested LED lamp working power switch and thermometric LED unit component operation current source are connected to computing machine; Computing machine connects capture card/thermometric LED unit measuring current source and voltage and current collecting unit;
It is characterized in that:
During measurement, thermometric LED unit assembly LED lamp isolated is linked into the thermometric LED unit component operation power switch in tester respectively, thermometric LED unit measuring current source, capture card and voltage and current collecting unit, tested LED lamp is accessed tested LED lamp working power switch, by tested for LED lamp plant-grid connection LED lamp working power switch, by thermometric LED unit component operation plant-grid connection thermometric LED unit component operation power switch, LED lamp power switch and thermometric LED unit component operation power switch access computing machine, synchronously control by computing machine,
Start after process of measurement, computing machine sends instruction and thermometric LED unit measuring current source is loaded into thermometric LED unit assembly always, through capture card, collects the thermometric LED unit assembly both end voltage V now do not applied under working current
0;
Then, computing machine sends instruction and thermometric LED unit component operation power supply is loaded into thermometric LED unit assembly through thermometric LED unit component operation power switch, LED lamp power supply is loaded into tested LED lamp through tested LED lamp working power switch simultaneously; The computing machine voltage and current collecting unit that sends instructions collects operating voltage and the electric current of thermometric LED unit assembly, and calculates the operating power P=VI gathering thermometric LED unit assembly;
Treat that tested LED lamp temperature no longer changes and reach stable state, computing machine sends instruction, turn off thermometric LED unit component operation power supply and lamp power, and the voltage that triggering collection card gathers on tested LED unit assembly changes V (t) in time simultaneously;
The temperature coefficient of thermometric LED unit assembly is α, LED unit assembly temperature rise change Delta T (t) in time=[V (t)-V
0]/α, the power P=VI loaded during thermometric LED unit component operation, tester calculates Δ T (t) curve, show that the thermal resistance of LED unit assembly i.e. the thermal resistance of tested LED lamp are formed.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310000861.5A CN103076551B (en) | 2013-01-01 | 2013-01-01 | A kind of LED lamp thermal resistance forms proving installation and method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310000861.5A CN103076551B (en) | 2013-01-01 | 2013-01-01 | A kind of LED lamp thermal resistance forms proving installation and method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN103076551A CN103076551A (en) | 2013-05-01 |
| CN103076551B true CN103076551B (en) | 2015-10-21 |
Family
ID=48153144
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201310000861.5A Expired - Fee Related CN103076551B (en) | 2013-01-01 | 2013-01-01 | A kind of LED lamp thermal resistance forms proving installation and method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN103076551B (en) |
Families Citing this family (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103293183B (en) * | 2013-05-15 | 2016-08-03 | 苏州大学 | A kind of method extracting LED information display system thermal capacitance and thermal time constant |
| CN103454568B (en) * | 2013-09-03 | 2015-09-09 | 南京华鼎电子有限公司 | A kind of method by temperature survey monitoring LED illumination lamp running status |
| CN103605085A (en) * | 2013-10-31 | 2014-02-26 | 桂林机床电器有限公司 | LED thermal characteristic test method based on structure function |
| CN103630851B (en) * | 2013-12-09 | 2015-12-30 | 天津工大瑞工光电技术研究院有限公司 | A kind of LED radiating module entire thermal resistance measuring method and measuring system |
| CN103926517B (en) * | 2014-04-24 | 2016-08-17 | 重庆大学 | The test device and method of power type LED thermal resistance |
| CN104391004B (en) * | 2014-11-27 | 2016-11-16 | 陕西科技大学 | A kind of test device and method of lossless light fixture heat dispersion |
| CN104470114A (en) * | 2014-12-01 | 2015-03-25 | 苏州立瓷电子技术有限公司 | Power supply circuit of LED lamp thermal resistance measurement system |
| CN104407280A (en) * | 2014-12-01 | 2015-03-11 | 苏州立瓷电子技术有限公司 | Thermal resistance measuring method of LED lamp |
| CN104569049B (en) * | 2015-02-13 | 2017-03-08 | 重庆大学 | A kind of high power LED device die bond layer heat dispersion fast evaluation method of no cold drawing |
| CN105241921B (en) * | 2015-11-07 | 2018-09-04 | 北京工业大学 | A kind of method and device of nondestructive measurement travelling-wave tubes thermal resistance |
| RU2624406C1 (en) * | 2016-03-29 | 2017-07-03 | Федеральное государственное бюджетное учреждение науки Институт радиотехники и электроники им. В.А. Котельникова Российской академии наук | Method of measuring the thermal impedance of leds |
| CN107490736B (en) * | 2017-08-07 | 2019-11-15 | 北京工业大学 | A kind of method and device of nondestructive measurement electronic functional module internal temperature and thermal resistance composition |
| CN109541428B (en) * | 2018-12-18 | 2021-03-02 | 北京工业大学 | Method and device for reducing HEMT thermal resistance measurement self-oscillation by adopting source-drain short circuit |
| CN109813751A (en) * | 2019-02-01 | 2019-05-28 | 山东开元电子有限公司 | LED street lamp radiator thermo-resistance measurement heating module |
| CN112285518A (en) * | 2020-10-12 | 2021-01-29 | 深圳康佳电子科技有限公司 | Simulation test method and system for thermal resistance of LED in module |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1743864A (en) * | 2005-10-14 | 2006-03-08 | 北京工业大学 | Semiconductor PN node diode device temperature rise measuring method and apparatus |
| CN101266280A (en) * | 2008-05-13 | 2008-09-17 | 上海大学 | High power light-emitting diode heat resistance and junction temperature test system |
| CN201773168U (en) * | 2010-09-08 | 2011-03-23 | 中国电子科技集团公司第十三研究所 | Thermal resistance tester of semiconductor power device |
| CN102193053A (en) * | 2010-03-08 | 2011-09-21 | 上海时代之光照明电器检测有限公司 | Method for measuring relation curve of forward voltage and junction temperature of LED (Light Emitting Diode) in lamp |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS54151375A (en) * | 1978-05-19 | 1979-11-28 | Nec Corp | Inspection method for semiconductor device |
| JPH1123503A (en) * | 1997-06-30 | 1999-01-29 | Sumitomo Electric Ind Ltd | Soil thermal resistance measuring instrument |
-
2013
- 2013-01-01 CN CN201310000861.5A patent/CN103076551B/en not_active Expired - Fee Related
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1743864A (en) * | 2005-10-14 | 2006-03-08 | 北京工业大学 | Semiconductor PN node diode device temperature rise measuring method and apparatus |
| CN101266280A (en) * | 2008-05-13 | 2008-09-17 | 上海大学 | High power light-emitting diode heat resistance and junction temperature test system |
| CN102193053A (en) * | 2010-03-08 | 2011-09-21 | 上海时代之光照明电器检测有限公司 | Method for measuring relation curve of forward voltage and junction temperature of LED (Light Emitting Diode) in lamp |
| CN201773168U (en) * | 2010-09-08 | 2011-03-23 | 中国电子科技集团公司第十三研究所 | Thermal resistance tester of semiconductor power device |
Non-Patent Citations (1)
| Title |
|---|
| LED器件热阻测试仪的研制;刘健等;《电子测试》;20080731(第7期);第53页左栏第2-7段 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN103076551A (en) | 2013-05-01 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103076551B (en) | A kind of LED lamp thermal resistance forms proving installation and method | |
| CN103162856B (en) | A kind of contactless great power LED method for testing junction temperature | |
| CN101266280A (en) | High power light-emitting diode heat resistance and junction temperature test system | |
| CN105510794A (en) | Heat resistance measurement method for pseudomorphic high electron mobility transistor (PHEMT) | |
| CN103616628B (en) | Schottky gate field-effect transistor temperature rise and thermal resistance measurement method and device | |
| CN102760727B (en) | Testing device and method of electromigration of interconnection line | |
| CN105203940B (en) | A kind of thermoelectric element reliability evaluation system and method | |
| CN106443401A (en) | Power MOS device temperature rise and thermal resistance component test device and method | |
| CN107490736B (en) | A kind of method and device of nondestructive measurement electronic functional module internal temperature and thermal resistance composition | |
| CN102116829A (en) | Method and device for measuring thermal resistance of diode | |
| CN104748885B (en) | The method that LED junction temperature is measured based on I V characteristic curves | |
| CN103592590B (en) | The test macro that a kind of LED component photoelectric heat is integrated and method | |
| CN106323496A (en) | Novel LED junction temperature measuring method | |
| CN106124955B (en) | The transient electrical test method of liquid cold plate thermal resistance | |
| CN103926517A (en) | Device and method for testing thermal resistance of power type LED | |
| CN105241921B (en) | A kind of method and device of nondestructive measurement travelling-wave tubes thermal resistance | |
| CN109709141A (en) | A kind of IGBT temperature rise and thermal resistance constitute test device and method | |
| CN105388181A (en) | Thermal resistance measurement sensor system | |
| CN105277583B (en) | A kind of device for simulating IGBT element heating | |
| CN202854290U (en) | Thermoelectric performance measuring apparatus | |
| CN100463148C (en) | Heat radiator | |
| CN106468678B (en) | A kind of pyroelectricity material device for measuring properties | |
| Elger et al. | Transient thermal analysis as in-situ method in accelerated stress tests to access package integrity of leds | |
| CN205139061U (en) | Device of nondestructive measurement travelling wave tube thermal resistance | |
| Hegedüs et al. | Lifetime test of pulse width modulated LEDs supplemented with thermal investigations |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20151021 |
|
| CF01 | Termination of patent right due to non-payment of annual fee |