Electronic – How to solder large smd components on a PCB with 2oz copper

pcbreflowsolderingsurface-mount

I’ve got a large inductor that needs to be soldered to my board. The pads are hidden underneath the component so hand soldering is not an option. The data sheet says to reflow at 260c for 40 seconds max.

I did just that with a hot air gun and pre-heating underneath at 180c. I still couldn’t get any flow after a whole minute since the thermal mass is just so huge.

My super wide 2oz copper traces aren’t helping either. How do I solder this part?

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Best Answer

I've had this problem before, the only way I've solved it is to heat the whole underside of the board with an IR reflow station for BGA's or using a hot plate.

The underside of the board needs to be substantially warm because most of the heat is wicking out through the internal planes and to the air. 2oz copper doesn't help, it's 4x better at transferring heat than 0.5oz.

The PCB doesn't need to be very hot, maybe in the 100C to 150C range.

You can then use two soldering irons to heat the pads or a hot air gun to get the part on.