[Jack Gassett] is developing a new breakout board for an FPGA. The chip comes in a ball grid array (BGA) package which is notoriously difficult to solder reliably. Since he’s still in development, the test boards are being assembled in his basement. Of the first lot of four boards, only one is functional. So he’s setting out to rework the bad boards and we came along for the ride.
To reflow the surface mount components he picked up a cheap pancake griddle. The first thing [Jack] does is to heat up the board for about two minutes, then pluck off the FPGA and the FTDI chips using a vacuum tweezers. Next, the board gets a good cleaning with the help of a flux pen, some solder wick, and a regular soldering iron. Once clean, he hits the pads with solder paste from a syringe and begins the soldering process. BGA packages and the solder paste itself usually have manufacturer recommended time and temperature guidelines. [Jack] is following these profiles using the griddle’s temperature controller knob and the timer on an Android phone. In the video after the break you can see that he adjusts the timing based on gut reaction to what is going on with the solder. After cleaning up some solder bridges on the FTDI chip he tested it again and it works!
[youtube=http://www.youtube.com/watch?v=OkjOwuSEzKU&w=470]
Nice documentary. Well done. Thanks.
this is great :-)
i used clothing iron instead of pancake cooker.
nice tutorial? no shit.
this tutorial will do more damage than help for the ones trying to learn BGA rework.
If the author would only tried to make a google search on the topic and watched a few videos would already know why his yield is so poor.
I’m surprised HAD would promote a tutorial this full of bad practices. This is wrong.
just a few picks:
– flux DOES matter. you cant use some random bulshit chinese flux and expect good repetability. btw rosin based flux is no good choice
– heat profile does not matter at all. not for the diy homebrew guys. you can make surprisingly good quality BGA rework with a 10$ heat gun, just with a little practice.
– solder type (lead/leadfree) does matter a lot
– using aggressive chemicals just to clean off the board? when we have almost harmless LFFR flux removers for a few dollars?
and i could go on and on …
A toaster oven can be used for this job on small boards it is actually better to heat everything to the same temp and not just the bottom of the board.
ALL BGA data sheets have a soldering profile to follow. Problem with only heating the bottom is that when cooling after re-flow it is possible to develop micro cracks in the solder joints because of uneven cooling. Not to mention the lead free solder issues.
Nice try, but here are some tips.
1. You you cleaning the old BGA use hot-air and warm up the board. It is much easier.
2. Then you solder the BGA you need heat on both top and bottom. My tips is buildning a solder-machine from a old toaster. Search on youtube.
3. You should only use the flush on the BGA, not on the board.
I have changed a few thousand BGA in my job.
//Flogger
Thank you for the support, tips, and the criticism, it is helpful to get this type of feedback. :)
I would respectfully point out the purpose and the audience of the video. The purpose is to make a small number of prototype boards to verify that the design works before offering it as a product to be manufactured by a professional assembly house. The audience is basement tinkerers and hackers like myself who don’t have access to the resources to solder a BGA chip the “correct” way.
I actually have the correct LFFR flux cleaners that I could have used, but I showed Brakleen because anyone can run to their corner auto parts store and pick some up. It takes a surprising amount of research to find and order a good flux cleaner.
The spirit of the video is to show that you don’t need crazy tools to pull of using a BGA chip. :)
Jack.
Glad you got them fixed. They’re not much fun. At least you didn’t use a hot air gun to flow the solder, and end up with lots of little balls of solder running abut under the IC body!
Maybe next time you might want to make a screen print mask? I’m not sure of any easy DIY method, but maybe HAD readers do? (You can buy expensive steel masks for individual IC profiles.)
I do know that screen printing solder is much much easier than doing each pad with a syringe.
I like this vid, simple methods and it wasn’t over particular & technical which I like
@abobymouse: I too would love to find out how to do solder paste application with DIY screen printing techniques. Anyone tried this??
ColinB,
I do soldering with a stencil all the time. I actually used a mylar stencil for the rest of the board. :)
Next time I make a board with a stencil I’ll record it.
Jack.
I think he did a pretty good job for what he had lying around. I’ve seen better and I’ve worse. There where many times when I didnt have the proper equipment to reflow/reball,but I used what I had at my disposal and it worked fine.
Its all about doing and learning from your mistakes.
I use zephyr bga flux and no paste (just use balls). Alignment is hard so have a courtyard silkscreened. Then toast till toasty.
Thank you for the video Jack.
Nice vid, a bit more closeup work might have been nice but it was good to see. While you can take on board the criticisms from the guys who do this daily, don’t take them to heart – if it works, thats good, if there’s a better way that’s easily accessible then change it, if not don’t fret.
Hey man, haven’t watched your video all the way through but here it goes. So I am the kinda guy who hasn’t got a lot of money and doesn’t know that much about electronics yet.*I say yet as I am trying to learn so feel feel to give links to decent tutorials* any way’s have a few questions. doesn’t the the heat from the bottom, hurt/mess up the bottom of the board? the reason I ask is, I a owner of a x-xbox 360 that has been been j tagged But after a while of usage I have the ugly Red Ring of Death :(, it needs re bailing. But as i said i can’t afford to send it off to some random larry and have a chance i may never see it, or having keys stolen so they can play there xbox online get me? would this method work on a 360? has you or anyone else got any other solution, i Don’t own a Heat gun nore a solder iron, but a solder iron i can get from next door. thank you in advanced for any info