The maximum electric current (IMAX) and the maximum voltage (VMAX) values are not the absolute maximum rated values. Instead, considering performance coefficients and heat radiation design, it is recommended that products are used to around 70% of the maximum electric current and voltage values. If products are used with voltages and currents which exceed the maximum values, heat absorption will decrease and Joule heating will increase. As a result, not only will efficiency be reduced, but the increase in temperature will have an adverse effect on the solder connecting the semiconductor and could lead to a break down and reverse diffusion. The maximum temperature difference (ΔTMAX) is the temperature difference between the sides of the semiconductor when the heat absorption is zero (0W). Also, the maximum heat absorption, QMAX, is attained when the temperature difference between the sides of the semiconductor is zero. Neither of these are actual values but rather they are theoretical figures that should be used as a guide when choosing modules. The relationship between electric current, voltage, temperature difference, and heat absorption are all illustrated by function diagrams in the design examples of the product data and application notes.