Printed Circuit Board Assembly & PCB Design SMT Electronics Assembly Manufacturing Forum

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


Steve Gregory

#13064

It IS possible to rework this BGA socket!! | 7 January, 1999

Hey ya'll!!

SUCCESS! I was able to get that monster off!...(Now I just gotta' be able to get it back on right...hehehe) If you remember, the whole reason I had to rework it was because somehow they got the hole positions wrong in the board for the two alignment pins at the bottom of the socket, which caused the socket to be soldered one row off on the board. I'm still trying to get to the bottom of how that happened...

But I called CTI this morning and talked to them about trying to rework this thing. I was told that they have heard of people reworking this socket, but it's pretty much been hit and miss, and trying this, or trying that. They said the one company that they know of who have got it down is SCI. I guess they build a lot of product that uses this socket and they've had their rework equipment modified to do this socket...you know, special preheater, nozzle, etc.

But, getting back to how I did it, it was a "Steve's start-up company mode special". Don't laugh too much, 'kay? Sometimes when you don't have all the things you want, you gotta make do with what you have...and I think if you use common sense, and take things slow, you can do just about anything anybody else can....maybe not as fast, but you can do it.

My rework system is one of them fancy Hakko 850's... you know, the full-vision (your own two-eyeballs), hand held unit. The nozzle I used was a 36mm square one that's normally used for QFP's...this one matched the basic shape of the pins in the socket. I had to take the cam lever, and the "Z-lok" cover off to expose more of the pin's surface to absorb the heat. I also used my trusty Fluke multimeter (it has a temperature function which you can plug a thermocouple into and see temps real-time) and threaded the tip of the thermocouple into the socket where it could tell me how hot it was getting down around the solder joints.

I was pretty liberal with the flux bottle, and really coated things to help me with heat transfer. Turned the Hakko on and watched my Fluke. It took about two and a half, to three minutes for me to indicate around 210-220 degrees centigrade inside the socket, and then I tested the socket with my tweezers gently at the corner to see if it would move, it moved easily, and I pulled it up without a hitch! Didn't even lift a pad!! YEEE-HAW! Not bad 'fer a in-gun-ear, huh? Usually, you don't want to let us get anything sharp or hot in our hands...(GRIN). The board had a little mole-hill where the socket was until it cooled back down and straightened out. The socket was actually in pretty good shape too, the plastic didn't degrade a bit.

Now, I just gotta figure out how to get this puppy located back over the pads accurately without those guidepins, I gotta clip them off...I'll let ya'll know how that goes...

-Steve Gregory-

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Ryan Jennens

#13065

Congratulations!! | 7 January, 1999

Congrats, Steve!!!!

There was never a doubt in my mind that you would get it. By the way, do you have any ideas how I could solder this BGA down when all I have to work with is a roll of duct tape, a swiss army knife, some fertilizer and a stick? (GRIN)

Relieved, Ryan Jennens

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Dave F

#13066

Re: It IS possible to rework this BGA socket!! | 7 January, 1999

Godd for you!!

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NAK

#13067

BGA | 11 January, 1999

Does your swiss army thingy have a magnifyng glass like mine?

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