Im designing a led driver for a friend of mine. The total consumption would be 0.5A (per Meter of led Strip) \* 9 Meter = 4.5A, or around 5A. The strips are connected via screw terminals. 
The problem is, that if I use a online width calculator, which says that the thickness should be ~7mm. If I would connect the Voltage Source with a Screw Terminal, the trace would interfere with the other pins of it. Could I just use 3mm (which fits) and then thicker the traces with solder or even solder wires to the points?
Thanks :)

Notes:
-PCB thickness is 35um
-aiming for single sided, to reduce amount of work.

~Straw

Pictures:
![Overview](https://i.stack.imgur.com/NJFzA.png)

![7mm Trace width](https://i.stack.imgur.com/dkyc6.png)