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## Junction to Case Thermal Resistance

Level 1
Level 1

Hello,

I am slightly confused by the following data on the following datasheet for BSC026NE2LS5:

What is the difference between these two values? Why do they contrast this much?

Thank you!

1 Solution

## Re: Junction to Case Thermal Resistance

Moderator
Moderator

Dear @Mark1,

The thermal resistance in general is a function of the junction and the ambient temperature of the power product, and it can be calculated as-

Rth = (Tjmax- Ta)/P   (K/W).

Where,

• Rth= Thermal resistance
• Tjmax= Maximum junction temperature
• Ta= Ambient temperature
• P= Power dissipated

The Ta (Ambient temperature) is usually reduced by mounting heat sinks on the product package and assist the heat flow from junction to ambient and for the given product, it is mounted on the bottom side as shown below.

Also, Due to variation in Lead frame thickness at the top and bottom of the die, the Rthjc is affected.

https://www.infineon.com/dgdl/Infineon-BSC026NE2LS5-DataSheet-v02_01-EN.pdf?fileId=5546d4624bcaebcf0...

Kind Regards

Shivam

## Re: Junction to Case Thermal Resistance

Moderator
Moderator

Dear @Mark1,

The thermal resistance in general is a function of the junction and the ambient temperature of the power product, and it can be calculated as-

Rth = (Tjmax- Ta)/P   (K/W).

Where,

• Rth= Thermal resistance
• Tjmax= Maximum junction temperature
• Ta= Ambient temperature
• P= Power dissipated

The Ta (Ambient temperature) is usually reduced by mounting heat sinks on the product package and assist the heat flow from junction to ambient and for the given product, it is mounted on the bottom side as shown below.

Also, Due to variation in Lead frame thickness at the top and bottom of the die, the Rthjc is affected.

https://www.infineon.com/dgdl/Infineon-BSC026NE2LS5-DataSheet-v02_01-EN.pdf?fileId=5546d4624bcaebcf0...

Kind Regards

Shivam