7.4 Thermal Information
THERMAL METRIC(1) |
DLPA4000 |
UNIT |
PFD (HTQFP) |
100 PINS |
RθJA |
Junction-to-ambient thermal resistance (2) |
7.0 |
°C/W |
RθJC(top) |
Junction-to-case (top) thermal resistance (3) |
0.7 |
°C/W |
RθJB |
Junction-to-board thermal resistance |
N/A |
°C/W |
ψJT |
Junction-to-top characterization parameter (4) |
0.6 |
°C/W |
ψJB |
Junction-to-board characterization parameter (5) |
3.4 |
°C/W |
RθJC(bot) |
Junction-to-case (bottom) thermal resistance |
N/A |
°C/W |
(1) For more information about traditional and new thermal metrics, see the
Semiconductor and IC Package Thermal Metrics application report,
SPRA953.
(2) The junction-to-ambient thermal resistance under natural convection is obtained in a simulation on a JEDEC-standard, high-K board, but because the device is intended to be cooled with a heatsink from the top case of the package, the simulation includes a fan and heatsink attached to the DLPA4000 device . The heatsink is a 22 mm × 22 mm × 12 mm aluminum pin fin heatsink with a 12 × 12 × 3 mm stud. Base thickness is 2 mm and pin diameter is 1.5 mm with an array of 6 × 6 pins. The heatsink is attached to the DLPA4000 device with 100 um thick thermal grease with 3 W/m-K thermal conductivity. The fan is 20 × 20 × 8 mm with 1.6 cfm open volume flow rate and 0.22 in. water pressure at stagnation.
(3) The junction-to-case (top) thermal resistance is obtained by simulating a cold plate test on the package top. No specific JEDEC standard test exists, but a close description can be found in the ANSI SEMI standard G30-88.
(4) The junction-to-top characterization parameter, ψJT, estimates the junction temperature of a device in a real system and is extracted from the simulation data for obtaining RθJA, using a procedure described in JESD51-2a (sections 6 and 7), but modified to include the fan and heatsink described in note 2.
(5) The junction-to-board characterization parameter, ψJB, estimates the junction temperature of a device in a real system and is extracted from the simulation data for obtaining RθJA, using a procedure described in JESD51-2a (sections 6 and 7), but modified to include the fan and heatsink described in note 2.