Attempting the impossible? BGA soldering... - Electronic Circuits Projects Diagrams Free

chris414 · 9th November 2009, 07:25 PM

Okay so i finally got the accelerometer I ordered ages ago, only to discover that in my haste I'd made the fatal error of not reading the datasheet properly... Does anyone know how i'd go about soldering that nightmare of BGA up there?^

jbeng · 9th November 2009, 07:33 PM

That's not a BGA. That's a QFN. Easier to solder than a BGA, but still not fun.

Jeff

chris414 · 9th November 2009, 07:41 PM

Oops my mistake... any advice? would i be able to touch a soldering iron to the connections without frying the circuitry inside?

DirtyLude · 9th November 2009, 08:39 PM

I've done it with a soldering iron before, but I now have a cheap hot air station and some cheap solder paste which works really well with these.

Is this a PCB with solder mask you are doing this with, or are you asking generally "now what" and don't have anything for this thing?

I did it a couple times on a home made board with a soldering iron. I first 'tinned' the pads by putting soldering on them and then soaking all of it up with solder braid. I then put solder on one set of pads on one side; put the chip down best I could and heated up the solder with the iron and adjusted the chip to the correct place. One it's one, you go around putting solder on all the other pads. The pads actually come up the sides of the package a bit, so you should be able to see if your solder is actually soaked into the pad/chip. Don't worry about too much solder, just soak up extra with a solder wick.

This worked for me the first time, but because the chip had a different version of firmware on it and it behaved 'wrong' I assumed it didn't work and messed with that chip a lot. I put a lot of heat on it without the chip having any problems, this chip was pretty hardy, but it's not a MEMs device either. It ended up looking pretty messy in the end with all my fixes, but it works fine.

I've also done some ADXL accels a while ago this way.

This was a DOSonChip device.

crutschow · 9th November 2009, 09:54 PM

If you want to solder it into a breadboard or vector board, you could solder small wires (such as wirewrap wire) to each pad with a low power, pointed tip soldering iron, and deadbug it (mount it upside-down with the pads on top).

kaptah · 9th November 2009, 11:27 PM

15watter from radio shack works beautifully. I filed the tip down to a nice size and it works great. i can soldierd to the tiniest of legs no prob with it.

RCinFLA · 10th November 2009, 03:33 AM

Get a butane soldering pen that has a hot gas nozzle attachment. Radio Shack used to sell a cheap one.

Better is Ungar pen.

indulis · 10th November 2009, 12:54 PM

If you have the paste, one of the guys here at work got pretty good results reflowing SMT components in a toaster oven (at home).

jbeng · 10th November 2009, 03:19 PM

One thing you have to be mindful of: does the large pad in the center of the chip need to be soldered down for heatsinking or grounding purposes? If so, you'll need to use a reflow method, because you obviously can't get under the chip with an iron. That's usually my biggest concern; damaging the chip during reflow by putting too much heat on it, while making sure it's soldered properly and maintaining alignment to the pads.

Jeff

cobra1 · 10th November 2009, 03:42 PM

solder the chip into an 18 pin dil socket thats what i did last time i used one of these

speakerguy79 · 10th November 2009, 04:52 PM

Solder paste + toaster oven is probably the most 'accessible' option for a hobbyist. Otherwise it is usually done with a hot air rework station in a professional environment (that's what our NASA certified techs do with those packages fwiw).

3v0 · 10th November 2009, 05:29 PM

I use a skillet to reflow solder paste.

The picture below is from the sparkFun site. SparkFun used this method for production for a while, maybe a few years. I use a Teflon fry pan on a gas range (burner).

The bad thing about the method is that the glue that holds the copper to the PCB gets hotter then it would with an oven or hot air. It has not been a problem for me.

The good thing is that the parts do not get as hot as they would with an oven or hot air.

This is a fast process, maybe 3 minutes to heat till the solder reflows and what time it takes to cool.

3v0

Lighty · 10th November 2009, 08:48 PM

Quote:

Originally Posted by 3v0

3v0

Being a novice, this is rather unexpected

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9th November 2009, 07:25 PM	#1
chris414	Attempting the impossible? BGA soldering... Okay so i finally got the accelerometer I ordered ages ago, only to discover that in my haste I'd made the fatal error of not reading the datasheet properly... Does anyone know how i'd go about soldering that nightmare of BGA up there?^

9th November 2009, 07:33 PM	#2
jbeng	That's not a BGA. That's a QFN. Easier to solder than a BGA, but still not fun. Jeff __________________ Nothing is impossible for the man who doesn't have to do it himself - Weiler's Law

9th November 2009, 07:41 PM	#3
chris414	Oops my mistake... any advice? would i be able to touch a soldering iron to the connections without frying the circuitry inside?

9th November 2009, 08:39 PM	#4
DirtyLude	I've done it with a soldering iron before, but I now have a cheap hot air station and some cheap solder paste which works really well with these. Is this a PCB with solder mask you are doing this with, or are you asking generally "now what" and don't have anything for this thing? I did it a couple times on a home made board with a soldering iron. I first 'tinned' the pads by putting soldering on them and then soaking all of it up with solder braid. I then put solder on one set of pads on one side; put the chip down best I could and heated up the solder with the iron and adjusted the chip to the correct place. One it's one, you go around putting solder on all the other pads. The pads actually come up the sides of the package a bit, so you should be able to see if your solder is actually soaked into the pad/chip. Don't worry about too much solder, just soak up extra with a solder wick. This worked for me the first time, but because the chip had a different version of firmware on it and it behaved 'wrong' I assumed it didn't work and messed with that chip a lot. I put a lot of heat on it without the chip having any problems, this chip was pretty hardy, but it's not a MEMs device either. It ended up looking pretty messy in the end with all my fixes, but it works fine. I've also done some ADXL accels a while ago this way. This was a DOSonChip device. Attached Thumbnails __________________ Mark Higgins

9th November 2009, 09:54 PM	#5
crutschow	If you want to solder it into a breadboard or vector board, you could solder small wires (such as wirewrap wire) to each pad with a low power, pointed tip soldering iron, and deadbug it (mount it upside-down with the pads on top). __________________ Carl Curmudgeon Elektroniker

9th November 2009, 11:27 PM	#6
kaptah	would this work? 15watter from radio shack works beautifully. I filed the tip down to a nice size and it works great. i can soldierd to the tiniest of legs no prob with it.

10th November 2009, 03:33 AM	#7
RCinFLA	Get a butane soldering pen that has a hot gas nozzle attachment. Radio Shack used to sell a cheap one. Better is Ungar pen.

10th November 2009, 12:54 PM	#8
indulis	If you have the paste, one of the guys here at work got pretty good results reflowing SMT components in a toaster oven (at home). Last edited by indulis; 10th November 2009 at 12:55 PM.

10th November 2009, 03:19 PM	#9
jbeng	One thing you have to be mindful of: does the large pad in the center of the chip need to be soldered down for heatsinking or grounding purposes? If so, you'll need to use a reflow method, because you obviously can't get under the chip with an iron. That's usually my biggest concern; damaging the chip during reflow by putting too much heat on it, while making sure it's soldered properly and maintaining alignment to the pads. Jeff __________________ Nothing is impossible for the man who doesn't have to do it himself - Weiler's Law

10th November 2009, 03:42 PM	#10
cobra1	solder the chip into an 18 pin dil socket thats what i did last time i used one of these

10th November 2009, 04:52 PM	#11
speakerguy79	Solder paste + toaster oven is probably the most 'accessible' option for a hobbyist. Otherwise it is usually done with a hot air rework station in a professional environment (that's what our NASA certified techs do with those packages fwiw).

10th November 2009, 05:29 PM	#12
3v0	I use a skillet to reflow solder paste. The picture below is from the sparkFun site. SparkFun used this method for production for a while, maybe a few years. I use a Teflon fry pan on a gas range (burner). The bad thing about the method is that the glue that holds the copper to the PCB gets hotter then it would with an oven or hot air. It has not been a problem for me. The good thing is that the parts do not get as hot as they would with an oven or hot air. This is a fast process, maybe 3 minutes to heat till the solder reflows and what time it takes to cool. 3v0 __________________ Please post questions to the forums. PM's are for personal communication. BCHS/3v0's Tutorials Junebug USB PIC programmer kit., USB Bit Whacker, The 15 Minute Printed Circuit Board! (+drill time) Last edited by 3v0; 10th November 2009 at 05:42 PM.