Total parasitic inductance after installation: 0.6+1.5=2.1nH. Note that at least two vias are actually required to install a capacitor, and the parasitic inductance is connected in series. If only two vias are used, the parasitic inductance introduced by the vias is 3nH. However, connecting several vias in parallel at one end of the capacitor can effectively reduce the total parasitic inductance, which is related to the installation method.
It can be seen that the resonant frequency of the capacitor is greatly shifted after installation, so that the high-frequency decoupling characteristics of the small capacitor are weakened. When designing the circuit parameters, the resonant frequency after installation should be calculated, because this is the actual performance of the capacitor on the circuit board.
The installation inductance has a great influence on the decoupling characteristics of the capacitor and should be kept as small as possible. In fact, how to minimize the parasitic inductance after installation is a very important issue.