# The Effect Of PCB Through Hole On Heat Dissipation

The effect of PCB through hole on heat dissipation

In natural convection heat dissipation products, the size of the hole in the PCB flexible printed circuit board has a great effect on heat dissipation. But how big is it, i don’t know. Let’s start with simple product analysis, the parameters of the hole of a single chip are the object, the influence of hole parameters on thermal conductivity is studied.

Condition:

4layer PCB flexible printed circuit board dimensions 100×100×1.6mm

Chip size: 40×40×3mm

Cross hole range: 40×40mm

Copper plating thickness: 0.025mm

Hole spacing: 1.2mm

Fill the hole: air

For the hole, the main parameters are the following parameters:

Hole diameter

Number of holes

The thickness of the plating copper

Of course, manual can also be calculated(parallel conduction):

But now that we have the software, we can use the software to quickly calculate the changes in various combinations:

1. The impact of hole diameter (other parameters unchanged)

 The thickness of the plating copper 0.025mm Cross hole range 1.2mm Number of holes 40×40 hole diameter Change parameters

 hole diameter Thermal conductivity via XY:W/m-K Thermal conductivity via Z:W/m-k 0.1 0.38 1.95 0.2 0.346 4.12 0.3 0.338 6.28 0.4 0.334 8.41 0.5 0.333 10.5

2. The impact of number of holes (other parameters unchanged)

 The thickness of the plating copper 0.025mm Cross hole range 1.2mm Number of holes Change parameters hole diameter 0.2mm

In order to ensure that the hole cover area is roughly the same, the spacing also changes with the number of holes

 Number of holes Cross hole range Thermal conductivity via XY:W/m-K Thermal conductivity via Z:W/m-k 10×10 5mm 0.327 0.56 15×15 3.33mm 0.33 0.84 20×20 2.5mm 0.334 1.23 25×25 2mm 0.337 1.72 30×30 1.66mm 0.34 2.33

3. The impact thickness of the perforated copper foil (other parameters unchanged)

 The thickness of the plating copper Change parameters Cross hole range 1.2mm Number of holes 40×40 hole diameter 0.3mm

In order to ensure that the hole cover area is roughly the same, the spacing also changes with the number of holes.

 thickness mm Thermal conductivity via XY:W/m-K Thermal conductivity via Z:W/m-k 0.017 0.325 4.482 0.025 0.338 6.283 0.035 0.355 8.376 0.045 0.374 10.29 0.055 0.394 12.04

Conclusion:

The purpose of heating the hole is to enhance Z’s ability to heat conduction, allow the heating component to cool quickly. Therefore, combined with the above date, we can find that increase the hole diameter ,increase the thickness of the plating and increase the number of holes can significantly strengthen the conduction of Z direction.