Dear Technetters,

I am having an issue with the very different sizes of Thermal Pads used on a
Power PCB mix. A 4 Layer PCB with 2 Oz Copper for the inner layers and 1 Oz.
+ Plating on the outside. 

At the Soldering, the small components get too hot while solder (Lead-Free)
does not get up high enough on the component side. 

I am wondering if there is a formula to calculate the size / shape and
dimension of the optimum Thermal Pad (Frein Thermique). 

Thank you for your input

Meilleures Salutations
Very Best Regards
Roland
 
www.PCBspecialist.com 
Roland Jaquet
14 Champ Budin
1258 Perly, GENEVA
SWTZERLAND
GSM+41-79-203-3723

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