MPC7445 datasheet(48/56 Pages) NXP

48 / 56 page

MPC7447A RISC Microprocessor Hardware Specifications, Rev. 5

Freescale Semiconductor

System Design Information

heat flux of adjacent components), heat sink efficiency, heat sink attach, heat sink placement, next-level

interconnect technology, system air temperature rise, altitude, and so on.

Due to the complexity and variety of system-level boundary conditions for today's microelectronic

equipment, the combined effects of the heat transfer mechanisms (radiation, convection, and conduction)

may vary widely. For these reasons, we recommend using conjugate heat transfer models for the board, as

well as system-level designs.

For system thermal modeling, the MPC7447A thermal model is shown in Figure 24. Four volumes

represent this device. Two of the volumes, solder ball-air and substrate, are modeled using the package

outline size of the package. The other two, die and bump-underfill, have the same size as the die. The

silicon die should be modeled 8.5

× 9.9 × 0.7 mm3 with the heat source applied as a uniform source at the

bottom of the volume. The bump and underfill layer is modeled as 8.5

× 9.9 × 0.07 mm3 (or as a collapsed

volume) with orthotropic material properties: 0.6 W/(m • K) in the xy-plane and 1.9 W/(m • K) in the

direction of the z-axis. The substrate volume is 25

× 25 × 1.2 mm3, and has 8.1 W/(m • K) isotropic

conductivity in the xy-plane and 4 W/(m • K) in the direction of the z-axis. The solder ball and air layer

are modeled with the same horizontal dimensions as the substrate and are 0.6 mm thick. They can also be

modeled as a collapsed volume using orthotropic material properties: 0.034 W/(m • K) in the xy-plane

direction and 3.8 W/(m • K) in the direction of the z-axis.

Figure 24. Recommended Thermal Model of MPC7447A

Bump and Underfill

Die

Substrate

Solder and Air

Die

Substrate

Side View of Model (Not to Scale)

Top View of Model (Not to Scale)

Conductivity

Value

Unit

Bump and Underfill (8.5

× 9.9 × 0.07 mm

)

0.6

W/(m • K)

0.6

1.9

Substrate (25

× 25 × 1.2 mm

)

8.1

4.0

Solder Ball and Air (25

× 25 × 0.6 mm3)

0.034

3.8

MPC7445 Datasheet(PDF) 48 Page - NXP Semiconductors

MPC7445 Datasheet(HTML) 48 Page - NXP Semiconductors

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56

Datasheet Download

Link URL