How to manually place 0.5mm pitch bga

Question

I'm a hobbyist and I'm trying to place a 0.5mm pitch BGA with tweezers. I've yet to land the chip properly on 3 attempts. At ~$30/board, I need a better way.

What are my options?

I've seen some DIY manual pick and place rigs, but I don't really feel like spending 2 weeks to rig a frame that's only marginally better than placing it by hand. Professional rigs seem to start at ~$4,000, and I just don't have that to burn.

I'm using a SiLabs EFM32 part, and the only variant that has both USB and all 16 cap touch channels comes in a 0.5mm pitch BGA. I have a "plab B" board that uses an external cap touch chip so I can use a TQFP part instead, but I'd really like to at least try and see what I can do with this: I have a solder stencil and boards printed for the BGA: All I need to do is land the thing properly.

Using 1 chip will be simpler, smaller, have lower power consumption and a lower total cost. Most importantly, I have everything ready to go except rock-steady hands. Any advice is appreciated! I'd love to be able to drop this thing in and go!

Answer 1

There are services that will place components like this for a fee. I think last time I got a quote from this place, it was like $25 for the service and I had to handle all the shipping and parts and such. I didn't need it in the end, but I was glad I found the service.

A simple google search returns places such as:

• Asian Circuits
• Circuit Technology Center
• Circle Prime

I haven't used any of these but there are services that will mount the BGA for you.

If you can't wait however long it takes for them to do the mounting, you could try to make some sort of placement stencil, although if you don't have the most steady hands, I doubt that the stencil would assist you in the margins you need.

Answer 2

After much ado, I did manage to get this to work by using no-clean flux, no solder paste, and a hot air gun from a rework station. Worked fantastic!

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I appreciate the advice: it was very good, but I was really looking for some tips on how I could try and get the chip on the board myself. I'll look into PCBA next time I do a part this small!! :)

The problem was that I was using solder paste through a stencil. This was creating small mounds of solder on the pads. Per the specs, this is preferred for production runs, as the paste helps marry the solder balls to the pads, so this is what I tried first. The problem is that because I'm essentially dropping the part on, the balls would just ski down the little mounds of solder instead of sitting atop them - this put the solder paste between the solder balls, creating wonderful little shorts during reflow. There was no nudging the part into place, either, because this would just slide the paste off of the pads, still creating shorts.

Using JUST paste worked fine the first try, but I wouldn't recommend it in a reflow machine because when the paste liquefies, the chip sails a cm or so away from the pads, so it has to be re-positioned once or twice. Probably not the BEST bond, but worked perfectly fine for a prototype.