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 , LMR62014 , 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

1.3 Die Size Impact

The chip or die pad inside a package can perform the same function as a heat spreader if the chip or pad is large enough. The function of the heat spreader is twofold. First, it spreads energy from the hot spot of the chip over a wider area on the package surface, thereby increasing convective energy loss. Second, it increases heat transfer from the pad to the lead fingers or to the package balls, which then conduct the heat to the PCB. Figure 1-2 shows the impact of die size on RθJA for a tape-based area array chip scale package (CSP). As shown, the RθJA for this package changes almost 8× with die size. It is important to re-measure or recalculate RθJA for a package if a die shrink is planned.

GUID-7386817F-BD83-44D5-A2EB-754A3DB1AA79-low.gifFigure 1-2 Die Size Impact on a CSP