RE: Building a Reflow Oven: Part 2 – Some Measurements

mcb1 — Thu, 31 Jul 2014 05:59:30 GMT

Shabaz

I managed to have a talk with Jac.

She mentioned that there is a heat profile where the temperature is raised over a period, then a stable heat for another period then a rise to the temperature that the solder melts, and finally a cooling profile.

All of these require careful control, and there is no set profile as it depends on various factors, and then some experimenting and investigation to ensure the joints are made properly.

I'll keep jogging her for more details.

mark

RE: Building a Reflow Oven: Part 2 – Some Measurements

jw0752 — Thu, 31 Jul 2014 05:18:30 GMT

Your enclosure will probably modify your results. It looks like you are getting convection with cooler air coming in from the sides. I am not sure how to block that but it is part of the physics of the situation. Perhaps a curtain or baffle. Harking back to some proven technology, the good old toaster uses heat elements that are as large as the target to provide an even toasting. If you can get an element with a larger surface area you will have more intensity at any given temperature and your temperature rise time will be faster. If you can keep the element fairly low mass it will be more responsive to regulation. Large mass heaters tend to have inertia unless your controlling sensor is right on the element. I know almost nothing about the requirements of a reflow oven so if I am not connecting with the parameters just ignore the ideas. My experience comes from different technology.

John