SPRA953D December   2003  – March 2024 CSD13201W10 , CSD13202Q2 , CSD13302W , CSD13303W1015 , CSD13306W , CSD13380F3 , CSD13381F4 , CSD13383F4 , CSD13385F5 , CSD15380F3 , CSD15571Q2 , CSD16301Q2 , CSD16321Q5 , CSD16322Q5 , CSD16323Q3 , CSD16325Q5 , CSD16327Q3 , CSD16340Q3 , CSD16342Q5A , CSD16401Q5 , CSD16403Q5A , CSD16404Q5A , CSD16406Q3 , CSD16407Q5 , CSD16408Q5 , CSD16409Q3 , CSD16410Q5A , CSD16411Q3 , CSD16412Q5A , CSD16413Q5A , CSD16414Q5 , CSD16415Q5 , CSD16556Q5B , CSD16570Q5B , CSD17301Q5A , CSD17302Q5A , CSD17303Q5 , CSD17304Q3 , CSD17305Q5A , CSD17306Q5A , CSD17307Q5A , CSD17308Q3 , CSD17309Q3 , CSD17310Q5A , CSD17311Q5 , CSD17312Q5 , CSD17313Q2 , CSD17318Q2 , CSD17322Q5A , CSD17327Q5A , CSD17381F4 , CSD17382F4 , CSD17483F4 , CSD17484F4 , CSD17501Q5A , CSD17505Q5A , CSD17506Q5A , CSD17507Q5A , CSD17510Q5A , CSD17522Q5A , CSD17527Q5A , CSD17551Q3A , CSD17551Q5A , CSD17552Q3A , CSD17552Q5A , CSD17553Q5A , CSD17555Q5A , CSD17556Q5B , CSD17559Q5 , CSD17570Q5B , CSD17571Q2 , CSD17573Q5B , CSD17575Q3 , CSD17576Q5B , CSD17577Q3A , CSD17577Q5A , CSD17578Q3A , CSD17578Q5A , CSD17579Q3A , CSD17579Q5A , CSD17581Q3A , CSD17581Q5A , CSD17585F5 , CSD18501Q5A , CSD18502KCS , CSD18502Q5B , CSD18503KCS , CSD18503Q5A , CSD18504KCS , CSD18504Q5A , CSD18509Q5B , CSD18510KCS , CSD18510KTT , CSD18510Q5B , CSD18511KCS , CSD18511KTT , CSD18511Q5A , CSD18512Q5B , CSD18513Q5A , CSD18514Q5A , CSD18531Q5A , CSD18532KCS , CSD18532NQ5B , CSD18532Q5B , CSD18533KCS , CSD18533Q5A , CSD18534KCS , CSD18534Q5A , CSD18535KCS , CSD18535KTT , CSD18536KCS , CSD18536KTT , CSD18537NKCS , CSD18537NQ5A , CSD18540Q5B , CSD18541F5 , CSD18542KCS , CSD18542KTT , CSD18543Q3A , CSD18563Q5A , CSD19501KCS , CSD19502Q5B , CSD19503KCS , CSD19505KCS , CSD19505KTT , CSD19506KCS , CSD19506KTT , CSD19531KCS , CSD19531Q5A , CSD19532KTT , CSD19532Q5B , CSD19533KCS , CSD19533Q5A , CSD19534KCS , CSD19534Q5A , CSD19535KCS , CSD19535KTT , CSD19536KCS , CSD19536KTT , CSD19537Q3 , CSD19538Q2 , CSD19538Q3A , CSD22202W15 , CSD22204W , CSD22205L , CSD22206W , CSD23202W10 , CSD23203W , CSD23280F3 , CSD23285F5 , CSD23381F4 , CSD23382F4 , CSD25202W15 , CSD25211W1015 , CSD25213W10 , CSD25304W1015 , CSD25310Q2 , CSD25402Q3A , CSD25404Q3 , CSD25480F3 , CSD25481F4 , CSD25483F4 , CSD25484F4 , CSD25485F5 , CSD25501F3 , CSD75207W15 , CSD75208W1015 , CSD83325L , CSD85301Q2 , CSD85302L , CSD85312Q3E , CSD86311W1723 , CSD86330Q3D , CSD86336Q3D , CSD86350Q5D , CSD86356Q5D , CSD86360Q5D , CSD87312Q3E , CSD87313DMS , CSD87330Q3D , CSD87331Q3D , CSD87333Q3D , CSD87334Q3D , CSD87335Q3D , CSD87350Q5D , CSD87351Q5D , CSD87351ZQ5D , CSD87352Q5D , CSD87353Q5D , CSD87355Q5D , CSD87381P , CSD87384M , CSD87501L , CSD87502Q2 , CSD87503Q3E , CSD87588N , CSD88537ND , CSD88539ND , CSD88584Q5DC , CSD88599Q5DC , DS90UH940N-Q1 , LM22670 , LM22671 , LM22671-Q1 , LM22672 , LM22672-Q1 , LM22673 , LM22673-Q1 , LM22674 , LM22674-Q1 , LM22675 , LM22675-Q1 , LM22676 , LM22676-Q1 , LM22677 , LM22677-Q1 , LM22678 , LM22678-Q1 , LM22679 , LM22679-Q1 , LM22680 , LM22680-Q1 , LM25574 , LM25574-Q1 , LM25575 , LM25575-Q1 , LM25576 , LM25576-Q1 , LM2574 , LM2574HV , LM2575 , LM2575HV , LM2576 , LM2576HV , LM2577 , LM2585 , LM2586 , LM2587 , LM2588 , LM2590HV , LM2591HV , LM2592HV , LM2593HV , LM2594 , LM2594HV , LM2595 , LM2596 , LM2597 , LM2597HV , LM2598 , LM2599 , LM2670 , LM2671 , LM2672 , LM2673 , LM2674 , LM2675 , LM2676 , LM2677 , LM2678 , LM2679 , LM2698 , LM2736 , LM2840 , LM2840-Q1 , LM2841 , LM2841-Q1 , LM2842 , LM2842-Q1 , LM3100 , LM3102 , LM3102-Q1 , LM3103 , LM3691 , LM43600 , LM43601 , LM43602 , LM43603 , LM46000 , LM46001 , LM46002 , LM5574 , LM5574-Q1 , LM5575 , LM5575-Q1 , LM5576 , LM5576-Q1 , LMR10510 , LMR10515 , LMR10520 , LMR10530 , LMR12007 , LMR12010 , LMR12015 , LMR12020 , LMR14203 , LMR14206 , LMR16006 , LMR24210 , LMR24220 , LMR61428 , LMR62421 , LMR64010 , LMR70503 , SN74SSQE32882 , SN74SSQEA32882 , TMS320C28341 , TMS320C28342 , TMS320C28343 , TMS320C28343-Q1 , TMS320C28344 , TMS320C28345 , TMS320C28346 , TMS320C28346-Q1 , TMS320F280021 , TMS320F280021-Q1 , TMS320F280023 , TMS320F280023-Q1 , TMS320F280023C , TMS320F280025 , TMS320F280025-Q1 , TMS320F280025C , TMS320F280025C-Q1 , TMS320F280040-Q1 , TMS320F280040C-Q1 , TMS320F280041 , TMS320F280041-Q1 , TMS320F280041C , TMS320F280041C-Q1 , TMS320F280045 , TMS320F280048-Q1 , TMS320F280048C-Q1 , TMS320F280049 , TMS320F280049-Q1 , TMS320F280049C , TMS320F280049C-Q1 , TMS320F2801 , TMS320F2801-Q1 , TMS320F2802-Q1 , TMS320F28020 , TMS320F28021 , TMS320F28022 , TMS320F28022-Q1 , TMS320F28023 , TMS320F28023-Q1 , TMS320F28026 , TMS320F28026-Q1 , TMS320F28026F , TMS320F28027 , TMS320F28027-Q1 , TMS320F28027F , TMS320F28027F-Q1 , TMS320F28030 , TMS320F28030-Q1 , TMS320F28031 , TMS320F28031-Q1 , TMS320F28032 , TMS320F28032-Q1 , TMS320F28033 , TMS320F28033-Q1 , TMS320F28034 , TMS320F28034-Q1 , TMS320F28035 , TMS320F28035-Q1 , TMS320F28050 , TMS320F28051 , TMS320F28052 , TMS320F28052-Q1 , TMS320F28052F , TMS320F28052F-Q1 , TMS320F28052M , TMS320F28052M-Q1 , TMS320F28053 , TMS320F28054 , TMS320F28054-Q1 , TMS320F28054F , TMS320F28054F-Q1 , TMS320F28054M , TMS320F28054M-Q1 , TMS320F28055 , TMS320F2806 , TMS320F2806-Q1 , TMS320F28062 , TMS320F28062-Q1 , TMS320F28062F , TMS320F28062F-Q1 , TMS320F28063 , TMS320F28064 , TMS320F28065 , TMS320F28066 , TMS320F28066-Q1 , TMS320F28067 , TMS320F28067-Q1 , TMS320F28068F , TMS320F28068M , TMS320F28069 , TMS320F28069-Q1 , TMS320F28069F , TMS320F28069F-Q1 , TMS320F28069M , TMS320F28069M-Q1 , TMS320F28075 , TMS320F28075-Q1 , TMS320F2808 , TMS320F2808-Q1 , TMS320F2810 , TMS320F2810-Q1 , TMS320F2811 , TMS320F2811-Q1 , TMS320F2812 , TMS320F2812-Q1 , TMS320F28232 , TMS320F28232-Q1 , TMS320F28234 , TMS320F28234-Q1 , TMS320F28235 , TMS320F28235-Q1 , TMS320F28332 , TMS320F28333 , TMS320F28334 , TMS320F28335 , TMS320F28335-Q1 , TMS320F28374D , TMS320F28374S , TMS320F28375D , TMS320F28375S , TMS320F28375S-Q1 , TMS320F28376D , TMS320F28376S , TMS320F28377D , TMS320F28377D-Q1 , TMS320F28377S , TMS320F28377S-Q1 , TMS320F28379D , TMS320F28379D-Q1 , TMS320F28379S , TMS320LF2401A , TMS320LF2402A , TMS320LF2403A , TMS320LF2406A , TMS320LF2407A , TPS54020 , TPS54218 , TPS54318 , TPS54320 , TPS54418 , TPS54478 , TPS54618 , TPS54622 , TPS54623 , TPS54678 , TPS56121 , TPS56221

 

  1.   1
  2.   Semiconductor and IC Package Thermal Metrics
  3.   Trademarks
  4. 1RθJA Junction-to-Ambient and RθJMA Junction-to-Moving Air
    1. 1.1 Usage
    2. 1.2 Test Card Impact
    3. 1.3 Die Size Impact
    4. 1.4 Internal Package Geometrical Configuration
    5. 1.5 Altitude
    6. 1.6 Ambient Temperature
    7. 1.7 Power Dissipation
    8. 1.8 RθJA Effective
  5. 2RθJC Junction-to-Case
    1. 2.1 Copper (Cu) Cold Plate RθJC Measurement
    2. 2.2 RθJC Application
    3. 2.3 Rθ(CS)
    4. 2.4 RθJC(top) and RθJC(bot)
  6. 3ΨJT, Junction to Top of Package
    1. 3.1 Case Temperature Measurement
    2. 3.2 ΨJT vs RθJC When Using Heat Sinks
  7. 4Rθ(JB) Junction-To-Board
    1. 4.1 Rθ(JB) Measurement Method
  8. 5ΨJB Junction-to-Board Characterization Parameter
    1. 5.1 ΨJB Application
  9. 6Industrial and Commercial Temperature Ranges
  10. 7Miscellaneous Definitions
  11. 8References
  12. 9Revision History

4.1 Rθ(JB) Measurement Method

The primary method to measure Rθ(JB) is as follows:

  1. A test package containing a thermal test die is mounted on a test board.
  2. A fine wire thermocouple (36–40 gauge) is glued or soldered to the device pin closest to the die. In the case of BGA packages, the thermocouple is soldered or glued to the trace exiting from under the package edge that is closest to the die.
  3. The board is clamped in a special double cold plate fixture with insulation between the package and the cold plate surfaces, but with thermal contact between the cold plate and the board. The cold plate heat sinks the PCB.
  4. Power is dissipated in the die.
  5. The temperatures of the die and pin are monitored.
  6. When steady state is achieved, the delta between the junction and pin temperatures is divided by the total power dissipated.

This procedure is defined more precisely in JESD 51-8.

GUID-CDB6C965-607D-4720-AA44-2AD9DC3039C4-low.gif Figure 4-2 Rθ(JB) Measurement Method