The reflow oven temperature profile is suited for characteristics of a particular circuit board assembly, the size and depth of the ground plane layer within the board, the number of layers within the board, the number and size of the components, for example. The temperature profile for a particular circuit board will allow for reflow of solder onto the adjoining surfaces, without overheating and damaging the electrical components beyond their temperature tolerance. In the conventional reflow soldering process, there are usually four stages, called "zones", each having a distinct thermal profile: "preheat", "thermal soak" (often shortened to just "soak"), "reflow", and "cooling".