Stop in for a cup of coffee
Here for example. It seems a sandy epoxy layer was added into the case first followed by a rubber RTV type layer to finish the encasement of the board. Not sure it was a good choice since silica based substrate acts as an insulator rather than dissapating heat effectively. The local temps around the board components must have gotten pretty high. No wonder it burned out.
Seems like they chose manufacturability ease over longevity. This approach makes manufacturing easy...but life span is sacrificed. They would have done better with a quality heat sink material to conduct the heat to the case. Instead, the RTV type material is encasing the upper part of the components like a silicone oven mitt and the layer under it can’t extract the heat well anyway.
Here for example. It seems a sandy epoxy layer was added into the case first followed by a rubber RTV type layer to finish the encasement of the board. Not sure it was a good choice since silica based substrate acts as an insulator rather than dissapating heat effectively. The local temps around the board components must have gotten pretty high. No wonder it burned out.
Seems like they chose manufacturability ease over longevity. This approach makes manufacturing easy...but life span is sacrificed. They would have done better with a quality heat sink material to conduct the heat to the case. Instead, the RTV type material is encasing the upper part of the components like a silicone oven mitt and the layer under it can’t extract the heat well anyway.