Calculating Reflow Slope

Are you following solder paste manufacturer's spec?? I know still some time it is hard to maintain slope particularly with less zone reflow oven.

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We do not know how your KIC2000 calculates slope.

Here's an approach to calculating slope: * Subtract the lower temperature from the upper temperature. [Temp|upper-Temp|lower] = Temp|change * Subtract the time when the lower temperature was measured from the time when the upper temperature was measured. [Time|upper-Time|lower] = Time|change * Divide Temp|change by Time|change to determine slope.

Generally, people calculate slope over the entire time that the temperature is changing value, because doing that averages all the little variations in slope over the course of the measurement. Actually, you can use any time period to calculate the slope, because the slope of a straight line is constant along the entire line. You just need to use temperatures and elapsed times that correspond to one another.

Look here: http://www.motivatingmath.com/html/Algebra3-2.html

See when you "change the time to calculate the slope over to 1 second", you need to reduce the temperature change calculation to correspond to the reduction in time. Otherwise, your slope seems to increase.

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