I am refering to the document SLMA002G PowerPAD™ Thermally Enhanced Package from TI. Kindly refer to page 9(screen shot attached). this is related to thermal vias present on the ther or open pad which solders to the open pad of an IC.
The statement in question is state below - The experiments conducted jointly with Solectron Texas indicate that a via drill diameter of 0.33 mm (13 mils) or smaller works well when 1 ounce copper is plated at the surface of the board and simultaneously plating the barrel of the via.
This means that if the layer is of 1 Oz then a drill dia of 13mils for via is enough for decent thermal dissipation,right ? What if the Cu is 0.5Oz how much would the drill dia need be changed ?