Effect of PCB Thermal Conductivity on the Operating Temperature of an SO-8 Package in a Natural Convection Environment: Experimental Measurement versus Numerical Prediction

The steady state thermal performance of an isolated SO -8 package is experimentally characterised on five thermal test Printed Circuit Boards (PCBs) and the results compared against corresponding numerical predictions. The study includes the low and high conductivity JEDEC standard, FR4 test PCBs and typical application boards. With each PCB displaying a different internal structure and effective thermal conductivity, this study highlights the sensitivity of component operating temperature to the PCB, provides benchmark data for validating numerical models, and helps one assess the applicability of standard junction-to-ambient thermal resistance (θja) data for design purposes on non -standard PCBs. Measurements of junction temperature and component-PCB surface temperature distributions were used to identify the most appropriate modelling methodology for both the component and the PCB.

[1]  Valter Motta.  New Jedec Standards for Thermal Measurements , 1997 .

[2]  H. Pape,et al.  Generation and verification of boundary independent compact thermal models for active components according to the DELPHI/SEED methods , 1999, Fifteenth Annual IEEE Semiconductor Thermal Measurement and Management Symposium (Cat. No.99CH36306).

[3]  B. A. Zahn.  Evaluating thermal characterization accuracy using CFD codes-a package level benchmark study of IcePak/sup TM/ and Flotherm/sup R/ , 1998, ITherm'98. Sixth Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (Cat. No.98CH36208).

[4]  Vincent P. Manno,et al.  Experimental characterization of board conduction sheets , 1993, [1993 Proceedings] Ninth Annual IEEE Semiconductor Thermal Measurement and Management Symposium.

[5]  K. Azar,et al.  Experimental determination of thermal conductivity of printed wiring boards , 1996, Twelfth Annual IEEE Semiconductor Thermal Measurement and Management Symposium. Proceedings.

[6]  J. Punch,et al.  Still-air junction-to-ambient thermal resistance of different devices as functions of the effective thermal conductivity of printed circuit boards , 1998 .

[7]  Tien-Yu Tom Lee,et al.  THERMAL STRATEGY FOR MODELING THE WIREBONDED PBGA PACKAGES , 1999 .

[8]  H. I. Rosten,et al.  Development, validation and application of a thermal model of a plastic quad flat pack , 1995, 1995 Proceedings. 45th Electronic Components and Technology Conference.

[9]  J. Richard,et al.  FACTORS AFFECTING THE CALCULATION OF EFFECTIVE CONDUCTIVITY IN PRINTED CIRCUIT BOARDS , 1998 .

[10]  Mark Davies,et al.  The thermal characteristics of a board-mounted 160 lead plastic quad flat pack. , 1994 .

[11]  C. Lasance,et al.  An Experimental Method to Determine the Effective Thermal Conductivity of Printed Circuit Boards , 1994 .

[12]  Tien-Yu Tom Lee,et al.  THERMAL MODEL OF A COMPONENT PACKAGE FOR SYSTEM LEVEL APPLICATIONS , 1997 .

[13]  J. Lohan,et al.  Experimental validation of numerical heat transfer predictions for singleand multi-component printed circuit boards in natural convection environments , 1999, Fifteenth Annual IEEE Semiconductor Thermal Measurement and Management Symposium (Cat. No.99CH36306).

[14]  B. M. Guenin,et al.  Analysis of thermally-enhanced SOIC packages , 1996 .

[15]  E. Beyne,et al.  Thermal Management of Electronic Systems II , 1997 .

[16]  D. Mallik,et al.  Thermal characteristics of single and multi-layer high performance PQFP packages , 1990 .

[17]  Peter Rodgers,et al.  EXPERIMENTAL VALIDATION OF NUMERICAL HEAT TRANSFER PREDICTIONS FOR SINGLE- AND MULTI-COMPONENT PRINTED CIRCUIT BOARDS IN A FORCED CONVECTION ENVIRONMENT: PART I - EXPERIMENTAL AND NUMERICAL MODELLING , 1999 .

[18]  Darvin R. Edwards,et al.  Thermal performance of tape based ball grid array over molded packages , 1998, Fourteenth Annual IEEE Semiconductor Thermal Measurement and Management Symposium (Cat. No.98CH36195).

[19]  Darvin R. Edwards.  Development of JEDEC standard thermal measurement test boards , 1996, Twelfth Annual IEEE Semiconductor Thermal Measurement and Management Symposium. Proceedings.