A while ago I decided to start designing my circuits using Surface Mount Devices (SMD).  There are many advantages to using SMD components over through-hole components.  Some of the major advantages are size and cost.  The smaller size means I can make the circuit boards smaller.  In addition, smaller components and smaller circuit boards means lower costs.  One of the disadvantages to SMD components is they are more difficult to solder than through-hole components.  The solution is to use what is called a reflow oven.  The following project details how I designed and built a reflow controller based on a MAX6675 Thermocouple interface and use it to control a common toaster oven in order to reflow surface mount circuits.  Check out the project here.