How would you solder the MCU & CPLD?

[rthorntn]

Hi,

I'm really asking about soldering just the MCU & DPLD for just now.

So I got some boards from pcbway, mainly to practice soldering although it would be cool if I could get them working.

I got this for $1 each:

https://www.pcbway.com/project/shareproject/CPLD_Fun_Board__Arduino_STM32F103_and_Altera_MAX_II_CPLD.html

And I have both a uyue 946C hot plate and an atten 852d hot air wand.

I have paste, I have a metal stencil for STM32F103C8T6 (48LQFP) and EPM240T100C5 (100TQFP).

The issue I see is the CPLD is on the front and the MCU on the back.  I don't see how I can just use the hot plate.  I think I will have to maybe hot plate the CPLD and hot air the MCU?

Thanks for looking.

Cheers
Richard

[rstofer]

Those should be fairly easy to solder by hand.  Google for 'drag soldering' and watch a couple of videos.

It is inevitable, and totally expected, that you will bridge a couple of pins.  Just make sure you have some very fine Solder Wick and plenty of flux.

Flux is the key to the process.  Run a ribbon of flux around the pads, place the device, tack 2 opposing corners and drag solder the rest.

It's really easy...  I don't have one of the club foot soldering tips, I just use my 1/8" chisel tip and it works well.  It doesn't hold as much solder so I can't always get all the pins down one side but it all works out.


If you want, you can use the hot plate method for one chip and just drag solder the other.  Drag solder the one with the widest pin spacing if they are different.

ETA:

Did I mention lots of flux?  Lots of flux!

https://www.amazon.com/MG-Chemicals-8341-10ML-Clean-Syringe/dp/B00425FUW2

[agehall]

I concur with rstofer. Dragsolder is the easiest way to go. If you need to you can also do a quick reflow to clean things up a bit afterwards.