Hi Guys,
I am trying to replace a 22 pin surface mount IC on a piece of Panasonic video quipment. I have all of the leads unsoldered but now I find that the IC is stuck to the board, maybe intentionally. It doesn't appear to be just the circuit board coating. It's more like the whole bottom surface is cemented.
I would appreciate hearing from anyone, off line, who has experience in removing a stuck IC from the board. I have tried flux removerand 91% Isopropal Alcohol with no luck. I hesitate to force it or destroy the chip since there are traces running beneath it. Any ideas of a safe solvent or another way to unstick this thing?
Roy wrote:
Hi Guys,
I am trying to replace a 22 pin surface mount IC on a piece of Panasonic video quipment. I have all of the leads unsoldered but now I find that the IC is stuck to the board, maybe intentionally. It doesn't appear to be just the circuit board coating. It's more like the whole bottom surface is cemented.
I would appreciate hearing from anyone, off line, who has experience in removing a stuck IC from the board. I have tried flux removerand 91% Isopropal Alcohol with no luck. I hesitate to force it or destroy the chip since there are traces running beneath it. Any ideas of a safe solvent or another way to unstick this thing?
Hi Roy,
are you sure it is cemented? Maybe it is an 'exposed pad' pad for thermal purposes. Take a look on Google how to handle.
73, Karl DL3DA in Goettingen
The IC may be held to the board with thermally setting epoxy. You can heat the IC with a hot air gun. This will over cure the epoxy and allow you to remove the IC without board damage. Use a small nozzle on the hot air gun and direct the heat to the IC. Use a dental pick as a pry bar under the IC to remove it as you are applying heat.
73 Glenn WB4UIV
At 05:38 PM 11/03/07, Roy wrote:
Hi Guys,
I am trying to replace a 22 pin surface mount IC on a piece of Panasonic video quipment. I have all of the leads unsoldered but now I find that the IC is stuck to the board, maybe intentionally. It doesn't appear to be just the circuit board coating. It's more like the whole bottom surface is cemented.
I would appreciate hearing from anyone, off line, who has experience in removing a stuck IC from the board. I have tried flux removerand 91% Isopropal Alcohol with no luck. I hesitate to force it or destroy the chip since there are traces running beneath it. Any ideas of a safe solvent or another way to unstick this thing?
-- Roy -- W0SL _______________________________________________ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
----- Original Message ----- From: "Roy" rdwelch@swbell.net To: "AMSAT BBS" amsat-bb@amsat.org Sent: Saturday, November 03, 2007 11:38 PM Subject: [amsat-bb] Surface Mount Repair
Hi Guys,
I am trying to replace a 22 pin surface mount IC on a piece of Panasonic video quipment. I have all of the leads unsoldered but now I find that the IC is stuck to the board, maybe intentionally. It doesn't appear to be just the circuit board coating. It's more like the whole bottom surface is cemented.
I would appreciate hearing from anyone, off line, who has experience in removing a stuck IC from the board. I have tried flux removerand 91% Isopropal Alcohol with no luck. I hesitate to force it or destroy the chip since there are traces running beneath it. Any ideas of a safe solvent or another way to unstick this thing?
-- Roy -- W0SL
Hi Roy, W0SL
If you are sure that the IC is gone and it must to be replaced then removing the stuck IC from the board is not strictly necessary.
1) Solder again all the original leads to the board. 2) Using a small and suitable scissor cut all leads at the point from where they just comes out from the IC 3) Open all leads a little bit apart 4) Superpose the new IC over the old one and solder all new leads to those original leads coming out from the board.
I did it several time when to remove a IC from the board is difficult and complicated.
Best 73" de
i8CVS Domenico
participants (4)
-
"Karl H. Görsmann" -
Glenn Little WB4UIV -
i8cvs -
Roy