@muneebr1 I’ve built many-a-board with modules. They can be tough to solder. They also fall apart when you’re heating them up (they themselves are typically just a small piece of FR4 with tightly placed components) So you should never move it while heat is being applied. (Unless you’re very very very confident you won’t screw it up. That’s me talking from looooots of experience )
You may think this is funny, but after all the years of doing this I use a skillet I got from Goodwill to reflow my one sided boards. If your board is one sided, I recommend going this direction. I’m using something like this:
It was inspired from an older Sparkfun tutorial here.
So far, I’ve used it to assemble a bunch of these boards.
Works well, as long as you don’t scorch the boards. (Especially if you’re using lead free solder)
The only way to tell when things are reflowing correctly is to watch the pads around the whole module. Do they look wet? If so, the pads underneath are likely to be as well. Sometimes you can observe the flux underneath bubbling/evaporating away. When the module adheres you may also see it shift into place. I use a good microscope (or magnifying glass) to watch duding the reflow process. That way I can estimate when it’s done.
Generally, a big module like that won’t have issues considering the pads are farther apart. I still recommend you get a stencil for your board. I also use OSH Stencils. I wrote up a tutorial a while back how to build a board using stencils. It may be useful for you.
I do use a hot air gun instead of the hotplate for that example though. (It’s equally a good alternative, but you have to be extremely careful not to roast your components. This is especially important for LEDs)
Also, for the stencil, you’ll want to place paste not flux. Here’s the type of solder paste that I use: https://www.digikey.com/product-detail/en/chip-quik-inc/SMD291SNL/SMD291SNL-ND/1160001