03-28-2021, 12:50 AM
I had very similar plans for improving the heat dissipation as yours, so it's realy good that we can share the ideas and results. I'll describe my plans below.
Did you use a 50x50 mm piece of copper sheet metal? I presume you glued it to the inside of the back cover, using thermal epoxy? Could you, please, post some pictures?
My plan was/is to reduce the thickness of the thermal pad between the back cover and the SoC. Out of the factory, the pad is really thick, which simply cannot be better than using a thinner thermal pad. So, I plan to use thermal epoxy to affix a piece of copper sheet metal to the inside of the back cover, right above where the SoC sits. That will allow use of a thinner thermal pad.
However, the back cover is rather thin and heat doesn't propagate well through it. So, another part of my plan was/is to use thermal epoxy to glue one or two flat heatpipes, about 10 cm in length, to the inside of the back cover, right next to where the thermal pad touches the back cover (more precisely, the aforementioned copper shim). That should allow heat to spread further across the back cover.
Based on your experience, would it be worth it?
Also, prolonged use of the CPU at 100% causes the battery charging IC (TI BQ24171) to overheat and stop charging the battery, as decribed in this post. Improving the spreading of the heat across the back cover should also reduce the heat soak into the components around the SoC, which includes the BQ24171.
Did you use a 50x50 mm piece of copper sheet metal? I presume you glued it to the inside of the back cover, using thermal epoxy? Could you, please, post some pictures?
My plan was/is to reduce the thickness of the thermal pad between the back cover and the SoC. Out of the factory, the pad is really thick, which simply cannot be better than using a thinner thermal pad. So, I plan to use thermal epoxy to affix a piece of copper sheet metal to the inside of the back cover, right above where the SoC sits. That will allow use of a thinner thermal pad.
However, the back cover is rather thin and heat doesn't propagate well through it. So, another part of my plan was/is to use thermal epoxy to glue one or two flat heatpipes, about 10 cm in length, to the inside of the back cover, right next to where the thermal pad touches the back cover (more precisely, the aforementioned copper shim). That should allow heat to spread further across the back cover.
Based on your experience, would it be worth it?
Also, prolonged use of the CPU at 100% causes the battery charging IC (TI BQ24171) to overheat and stop charging the battery, as decribed in this post. Improving the spreading of the heat across the back cover should also reduce the heat soak into the components around the SoC, which includes the BQ24171.
