Surfact Mount Oven Profiles

[wuchy143]

Hello,

I'm setting up my first profile for a Heller oven.(Heller 1707) I'm using Kester's NXG33 solder paste, 4 layer, .062" PCB. I have the profile matching the spec. very well. My only question/concern is shocking the board with too much heat as it hits the zone in my oven. Is there a rule of thumb for a decent *Celcius/second. I want to say I read 3*C/s but I can't find where I read that. Does anyone with more experience able to shed some light?

Thanks

 

[duffy]

I've taken the boards off my 74°F workbench and put them straight in my 500°F toaster oven with no problems - if THAT's any help.

 

[ronsimpson]

There are profiles on the internet.

I take a board at room temp and place it in a cold oven. Set the temp for max and watch the solder. At about 5 to 8 minutes the solder paste at the edges of the board turn from gray to silver. Then the solder in the center of the board flows. I watch the large components in the center of the board because they are last to flow. Then I open up the door and turn off the power. Don't bump the board until the solder sets up!!!

 

[RCinFLA]

https://www.electro-tech-online.com/custompdfs/2012/03/Solder_Reflow_LeadFree.pdf

https://www.electro-tech-online.com/custompdfs/2012/03/an353.pdf

ww1.microchip.com/downloads/en/AppNotes/00233D.pdf