Package attachment to thermal base by means of soldering

AN3232

22/26

Doc ID 17594 Rev 3

Note:

The profiling tolerance is + 0 °C, -X °C (based on the machine variation capability)

regardless of what is required to control the profile process, but at no time does it exceed -5

°C. The producer assures process compatibility at the peak reflow temperatures.

Package volume excludes external terminals (balls, bumps, lands, leads) and/or non-

integral heatsinks.

The maximum component temperature reached during reflow depends on package

thickness and volume. The use of convection reflow processes reduces the thermal

gradients between packages. However, thermal gradients due to differences on thermal

mass of SMD packages may still exist.

Ultimately, the most stressful aspect of soldering for packaging consisting of plastic or epoxy

layers is related to rapid transition between process steps. For this reason, it is

recommended to never exceed the ramping rates recommended in J-STD-020D at the

package level.