Bga pad repair
 

Hi all,,:) as we see there are many thread discussing about bga chip and solutions, in this opportunity i'm trying to post a new topic " BGA PAD PEPAIR " anybody with your experiences, ideas or solutions would please to share with us...Have a nice day:)
example pic :
http://i675.photobucket.com/albums/v...g?t=1294809950

Hello,
BGA PAD repair requires good soldering skills and most important is steady hand, very good eye sight or you have to use very good quality lens (magnifier), buy a good quality solder gun with temp controller (should support lead free) with fine soldering tip, some lead free solder wire, copper de-soldering wick and a blade.

BGA PAD repair requires time and attention, some pads are dummy on the pad so need not worry if it has come out, some bga pads will be test points so no need to worry about it, but check for the pads which are important excluding the other two i have mentioned earlier, once the pads are noted for reconstruction, take the blade remove the conformal coating till the pth point or till it has broken and first solder copper de-solder wick strand to the end where the bga pad line is broken, then route copper wick strand to the bga pad where it will come into contact with bga ic solder ball , cut the strand using a blade. use lead free solder for bga contruction because if you use lead based solder the melting point is 183 deg and if the bga ic you are replacing is lead free (215-220 deg) chances are the copper strand you have used for reconstruction of the pad will move.

if possible will post photos of reconstructed pads.

bye

bga pad repair
 

Woow,..thank a lot for your great ideas on how to repair bga pads..seems Mr.Pentu is having many experiences in bga repair section..really hope you can share more about it..it would more clearly and exiting if you can put some pics on how you use de-soldering wick to rebuilt a missing bga pads as the picture i showed above..
Mr.Pentu do u know each bga pad on board has it function or not? or some just stand on hole and act like a ground.i see some just stand alone on hole without a wire joinned from board, but mostly are jointed as we can see..
thank for your time to share with us..:)

anybody has more exiting experiences in repairing bga pads? please share, thx...:)

Pentu and his team are expert in pad repairs. To know which pads are needed and which are not, find the chip's pinout diagram and you'll know which pins are connected to ground, which are test points and which are essential for the functioning of the chip.

B.R.

i want to post the photo of pad repair but when i upload it says upload fail
:confused:

hi Mr.Pentu:)
you may try to upload again..maybe the server is busy or the line is going down when you upload it,,never mind pls try again...
anyway last night i was trying to clean another acer aspire 4520 bga pads for reball, as usual i put a little flux first, then set solder tip for about 350-400 C to swipe all solder balls on pad slowly,.after that i use "BAKKU" solder wick to clean the lefted solder balls carefully on pad,,
i used to clean it from right side to left for whole pads, until now i still hv a problem to fix it well, i can see some pads will be lefted ( take off by solder wick ) when i cleaned it, i hv run it slowly and carefully but some pads still going to lefted,,
all i want to know is..am i using a wrong solder wick or having a wrong direction to clean the pads?any tips for this pls guide me to the right way for doing this better as i hv tried for more than 10pcs of bga pad on boards and all with fails...
thank you...

Remove excess solder directly with the solder tip and then apply tiny amount of flux to the wick and use it to remove solder, dont try to cover large area at a single time.

Pad re-work photo

http://i1237.photobucket.com/albums/...tu1970/PAD.jpg

For this type of repair you could use with success any sylver / graphite solution to redraw the print http://www.e-piese.ro/components/com...3a9b433d92.jpg

WBR,
gsm9l;)

After the IC is Placed

http://i1237.photobucket.com/albums/...erICPlaced.jpg

thanks for the suggestion, but they have specified temp tolerance of -60 degree to 120 degree in the catalogue, in BGA rework it exceeds well beyond these temperatures
thanks

halim XU for Acer 4520 give bottom temp more than what use for other boards

bye

Hi,Mr.Pentu
alright i'll try it for nxt board, now still learning to clean bga pads well to make sure no any pads lefted again..thank for your great suggestion..bye

Hi Pentu, thats some good quality work you have done.

Hi All,
I just trying to clean a v3000 bga pads ,again one of the bga pad lefted when i clean it with solder wick, but i can see the pad has no connection line with others / just stand alone on hole , is it has a function or not? is it fine if i just put some glue to fix it back on hole,,or anybody has v3000 bga scematic for make sure the fuction for each bga pads
please help..thanx