Issue link: https://iconnect007.uberflip.com/i/1285883
22 DESIGN007 MAGAZINE I SEPTEMBER 2020 component is smaller, the temperature here is 20 K lower. This is the effect of heat spread- ing in the inner layers. Without the two inner layers, the temperature would climb to 80°C (Figure 6). 3. EVB-USB580x_A This board is one of the standard examples of an Altium Designer [6] instal- lation. EVB-USB5806 [7] is a demonstration and evaluation platform for the 6-Port SS/HS USB Smart Hub on a four-layer PCB. Below U1, there is a Cu pad that mates with the internal heat slug. The pad is only in con- tact with GND and can only dissipate heat there. In the Internal2 and Bot- tom layers, potential separations limit the heat spreading around U1 (Figure 7). The result of the calculations is given in Fig- ure 8. The circular isotherms on top are the result of the full surface copper in i1 (GND). Figure 6: Top layer temperature. Due to the two flooded inner layers, the isotherm is oval-shaped. Figure 7: EVB-USB580x_A. General view of the top in pink, detail inner layer 1 (GND) green, detail inner layer 2 in brown, and detail of bottom in blue.