If the PCB heat dissipation area is not enough, will increasing the copper thickness help improve the heat dissipation of the PCB?

小太阳yy

If the PCB heat dissipation area is not enough, will increasing the copper thickness help improve the heat dissipation of the PCB? [Copy link]

 

If the PCB heat dissipation area is not enough, will increasing the copper thickness help improve the heat dissipation of the PCB?

For example, in actual applications, if the PCB area is not enough, should we prioritize increasing the area or increasing the copper thickness? Is increasing the copper thickness effective? Please give me some advice.

w494143467

A heat sink can also be added.

annysky2012

Increase area, increase copper thickness, add heat sink, add fan

chunyang

Increasing the copper thickness can improve heat dissipation, but the effect is usually not as good as increasing the area. The specific effect requires calculation or actual testing. There are many factors that affect thermal design, which need to be considered comprehensively.

小太阳yy

chunyang posted on 2021-9-28 20:33 Increasing copper thickness can improve heat dissipation, but the effect is usually not as good as increasing the area. Specific calculations or actual tests are required. There are many factors that affect thermal design, and a comprehensive...

I am also worried that simply increasing the copper thickness to increase heat dissipation is a bit risky.

gmchen

We have done experiments. For aluminum radiators, the heat dissipation effect is very small after the length of the radiator from the heat source is greater than about 70 times the thickness, and it can be considered that it is basically ineffective for heat dissipation. If the length-to-thickness ratio is less than 70, the heat dissipation effect is basically related to the heat dissipation surface area, and is related to the thickness but not much. Therefore, if the maximum length of the radiator from the heat source is greater than 70 times the thickness, increasing the thickness can significantly increase the heat dissipation. On the contrary, if the length-to-thickness ratio is less than 70, increasing the thickness will not help much for heat dissipation.

This experiment is based on the results of natural heat dissipation of an aluminum radiator (without a fan). Other conditions have not been tested, so the specific values are unknown, but I believe similar results would be obtained.

小太阳yy

gmchen posted on 2021-9-29 12:29 We have done experiments. For aluminum radiators, the heat dissipation effect of the part after the radiator length from the heat source is greater than about 70 times the thickness is very small, which can be...

Brother, I mean pure PCB, not heat sink

damiaa

Adding solder to the pcb helps.

topwon

From the perspective of heat dissipation, I think the copper thickness has little effect. It is better to expose the copper to reduce thermal resistance. I think the main purpose of adding copper thickness in the design is to reduce the resistance of the circuit and thus reduce the power consumption and heat generation on the wire.

gmchen

Xiaoyangyy posted on 2021-9-29 13:32 Brother, what I mean is a pure PCB, not a heat sink

The principle should be the same. If the line dimension of the PCB heat dissipation area is much larger than the copper foil thickness, increasing the copper foil thickness is effective. If the ratio of line dimension to thickness is not very large, it is estimated that increasing the thickness will be of limited help.

In addition, the exposed copper suggested above should be a good idea.

PowerAnts

Without data and basic arithmetic, you can only learn from Edison: Try!

PowerAnts

How much does opening a window help heat dissipation? Isn't it enough to check the thermal conductivity and thickness of the solder mask and the maximum heat flow per unit area? I'm very doubtful! The temperature difference between the inside and outside of 20um green oil is 0.02-0.05k. For black oil, auxiliary injection is better than green oil, and it's better not to open a window.

PowerAnts

PowerAnts published on 2021-10-1 00:25 How much help does opening a window have for heat dissipation? Isn't it enough to check the thermal conductivity and thickness of the solder mask and the maximum heat flow per unit area? Very doubtful! The temperature difference between the inside and outside of the 20um green oil is 0. ...

Treat replying to posts as solving your own problems, which is a kind of cultivation

PowerAnts

The purpose of opening a window is to steal tin. The resistivity of 6337 tin is 7 times that of electrolytic copper. The window opening rate of high-power wiring is 50%, stealing 0.5mm of tin, which is equivalent to 1oz becoming 1.5oz. However, for wave soldering, the tin sprayed by opening a window is useless. If the thickness of the tin spraying is not specified, the hot air knife of the manufacturer's ordinary process can only retain 3-5um, which is equivalent to increasing the copper thickness by less than 1um at most. If the silver of 200um thick tin is enough to make a 2oz board, it is better to paste copper strips.
So, paste copper or brass? Leave it to the readers to think about

PowerAnts

gmchen published on 2021-9-29 12:29 We have done experiments. For aluminum radiators, the heat dissipation effect of the part after the radiator length from the heat source is greater than about 70 times the thickness is very small, which can be...

Most projects use 20 times the heat sink, and the cross-sectional area of different parts of the heat sink is allocated according to the heat flow size. If the distance from the heat source to the coldest end is 100mm, the power of the aluminum plate with a heat source of 8mm and a cold end of 2mm is 40% greater than that of the 5mm average thickness. The thermal conductivity of different grades of aluminum alloys is different, and the angle varies from 4 to 7 degrees.