In my circuit I am using a stepper motor driver, providing me up to 3 A current per trace. Thus I calculated the required trace width with a trace calculator, which told me to use a trace width of 0.07'' (or 1.78mm). Unfortunately, the chip itself does not allow me to connect them directly onto the IC legs. These are only 0.012'' (or 0.3mm) traces.
Therefore I created this routing:
Pin 1, 21, 24 and 26 are responsible for the high current. I used 0.012'' traces right after the pin connections, then switched to 0.016 and 0.024 and as soon as possible to 0.07''-traces (the big vias). Is that enough, or will the possible heat damage my board? How can I improve it (instead of soldering copper bars on it)?