Measures For Heat Release In Designing The Board - Renesas R-IN32M4-CL2 User Manual

R-IN32M4-CL2 User's Manual: Board design edition 7. Thermal Design <R>
7.2.1

Measures for Heat Release in Designing the Board

(1) Thermal Vias
Placing as many vias to the power supply and GND areas as possible below the center of the package increases the
number of paths for the flow of heat in the z direction. We recommend placing one via for each power supply and GND
ball.
(2) Power Supply and GND Planes
Secure as large an area as is possible for the power supply and GND planes of the board. This enables the broad diffusion
of heat through vias in the direction of the surface plane. Dividing paths for heat dissipation from plane to plane
decreases the effectiveness of heat dissipation. Therefore, place the GND pattern in such a way that the paths are divided
as little as is possible. We recommend L2 for the GND layer.
(3) Increase the Number of Board Layers, and Bring the GND Pattern out to the Surface Layer
Increasing the number of Cu wiring layers in the printed circuit board expands the area for hear release. Where possible,
place areas of the GND pattern on the surface layer and connect them to the main GND pattern via thermal vias. This
further improves heat dissipation. The board should have at least four layers, and we recommend six.
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Dec. 28, 2018