Going over IC max temp in reflow oven?

Question

I'm a beginner-ish in PCB making and I want my workflow to be faster by using an oven instead of doing all the solder by hand. I searched for few hours without answer to my question.

A low temperature solder paste melting point is 138°C, so around 165°C reflow. On the datasheet of all my IC, it is written that the Absolute Max temperature is 150°C.

I want to know if it's okay to go over the max temperature of ICs to solder them to a PCB in an oven. Am I forced to use low temperature solder paste, or can I go with higher melting point solder paste?

The main IC I have are power mosfets and a ESP32 Wrover (which is pre-packaged).

Answer 1

The components have a temperature profile used for soldering, which is separate from the absolute max temperature during use.

For example if you open the ESP32 datasheet, there is a temperature profile that allows it to be heated up to above reflow temperatures for 60-90 seconds to melt the solder and it can be up to 250°C during the reflow.

Answer 2

The absolute max temps of most IC's is 125C to 150C, which is usually related to the plastic or epoxy melting points (or where it deforms, most other materials are good to much higher than 250C like the metals and semiconductors when no electricity is flowing).

So one would think that an IC can't exceed 125C (ish), but it can briefly for a few seconds. And this is why the IC reflow profile should be followed. The IC reflow profile can be found in datasheets or on the manufacturers website.

The IC's reflow profile should work with most of not all general solder profiles