I want to understand a few terms.
My Questions :
- What does Maximum PCB operating Temperature for a PCB in general depend upon?
- Maximum PCB Operating temperature depends on Tg (Glass Transition temperature). Above this Tg value, the base material may deform or the properties of it may get changed. Am I correct?
If not, On what other factors does Tg depend upon?
If I am correct, how to find the value of Tg? Is it different for different dielectric materials?
What does PCB self heating mean? My understanding - When a board is in normal working condition, the temperature of PCB increase due to the active working components and hence raise the temperature of the PCB. Am I correct? Please help me understand this with the correct definition of PCB Self heating and what would be default value that needs to be taken as the PCB Self heating temperature as a thumb rule for worst case calculations?
Thermal Resistance Parameter (Junction to Ambient & Junction to Case)
- For example, lets take a part which I am using. TPS54260 - HVSOP Package.
In the above image, we have thermal information of Thermal Resistance between Junction to Ambient as 62.5degC/W and Junction to Case as 83degC/W.
Does it mean, if the IC dissipates 1W, the temperature at the Junction of the IC= (62.5+Ambient Temperature)degC ?
And the temperature at the case of the IC = (83+Ambient Temperature)degC ?
Is my understanding correct?
And what is the reason that Junction to case thermal resistance is higher value than junction to ambient temperature?
Junction to Ambient thermal resistance is just the sum of all the internal thermal resistances, right?
Please help to understand