I am going to use brushless motors of 40vdc and 4 amps load. Should I use SMD or PCB? DOES SMD supports high watt diode and capacitors like PCB?

 

So that we are all using the same terminology. SMD is Surface Mount. PCB is printed circuit board. The term you are probably referring to is Through Hole, as in the leads go through a hole. PCB can have both SMD and Through Hole components.

Now that is cleared up, SMD or Through Hole for that type of load. Typically, SMD components are for smaller loads and through hole components can take larger loads. But I have found SMD components that can take a large load, but they are also expensive. In the end, it depends on a number of factors, including can you solder SMD components, can you afford the potentially more expensive SMD components that take high loads, and most important of all, does your project require SMD components because of space/weight constraints?

Take a look at Digikey/Mouser/Newark/Element14 (whichever you prefer) and see what you turn up. Let us know how it turns out.

 

Or, go "hybrid." That's the in thing . SMD for signals and low power, TH for the big stuff. It is not that SMD for high power aren't available, but they are the same size as TH of the same power and may cost more. For an example, look at some of the larger aluminum electrolytics in SMD and radial TH.

John

 

4A is not high current. You can find plenty of suitable SMD components for the same cost or less than thru-hole at this current level.

Your decision should be based on what you are comfortable soldering and working with.