196-pin BGA replacement - Page 1
Forum section: electronics / repair

author: TheMG
author_rank: Frequent Contributor
timestamp: August 08, 2020, 04:55:56 pm
content: Ethernet controller damaged by lightning, needs to be replaced. Think this is doable with a simple hot air station (Quick 861DW)? I've never tackled anything BGA before.I know larger BGAs with a much higher pin count can be extremely tricky without a BGA rework machine, but this seems to be a fairly small low pin count BGA as far as BGAs go.I haven't ordered the replacement IC yet, will do so if there's at least a reasonable probability this will succeed.

author: wraper
author_rank: Unknown
timestamp: August 08, 2020, 05:00:54 pm
content: This should be trivial. 15x15 mm IC with 1 mm ball pitch is a piece of cake. Preheaeter is advised but as this likely is not even a lead-free you should be fine even without it.

author: TheMG
author_rank: Frequent Contributor
timestamp: August 08, 2020, 05:31:46 pm
content: The original is lead-free but I will go leaded with the replacement to improve my chances.$8 for the replacement IC so no huge loss if I make a mess of it. If successful, that's a $1500 device saved from the waste bin.

author: TheMG
author_rank: Frequent Contributor
timestamp: August 08, 2020, 07:15:01 pm
content: Got the old IC off the board, cleaned up and tinned the pads. One pad went MIA but it's not connected to anything anyways.My plan of attack is when I get the replacement chip apply some flux, set the IC down on the pads and apply heat until it reflows and hope for the best.Unfortunately it seems the only place I can easily source this IC (Intel GD82551ER) is ebay and it's like 1-2 months wait for shipping. Not that I'm in a hurry or anything, but it's the suspense of not knowing if I can revive this device while I wait for the IC to show up in the mail! I guess that's what you have to be prepared to deal with trying to source ICs that have long been obsolete and out of production.

author: aqibi2000
author_rank: Regular Contributor
timestamp: August 08, 2020, 10:54:46 pm
content: DO NOT tin the pads when attaching the replacement IC.Get some solder wick and remove what you have done

author: wraper
author_rank: Unknown
timestamp: August 08, 2020, 11:04:06 pm
content: Quote from: aqibi2000 on August 08, 2020, 10:54:46 pmAnd what he had done? Did you ever replace BGA? Don't use solder wick unless you absolutely need it. Solder wick is the easiest way how to tear off those small pads. Placing chip as is right now will work just fine.

author: wraper
author_rank: Unknown
timestamp: August 08, 2020, 11:34:36 pm
content: I noticed that at least one pad has excessive solder on it. And two other pads are coming off, you should push them down for them to stay flat and not touch them afterwords because it's extremely easy to completely tear them off.

author: Miti
author_rank: Super Contributor
timestamp: August 09, 2020, 10:03:54 am
content: I don’t know this particular chip but many Intel Ethernet chips need programming. Make sure this doesn’t.

author: aqibi2000
author_rank: Regular Contributor
timestamp: August 09, 2020, 01:21:32 pm
content: FYII’ve replaced hundreds of BGA chipsets, this is not even fine pitch. I’ve been using industrial grade using IR and BGA Rework stations and by rework by hand using hot air like the OP is suggested to do.Working or much larger and smaller packed which offer their own technicalities in thermal mass with IHS, and double sided BGA PCBs.If you know anything about rework it starts to get tricky when you’re working with 0.35mm solder balls on PCH.Remove the solder you have applied.

author: RomDump
author_rank: Regular Contributor
timestamp: August 09, 2020, 01:40:10 pm
content: Quote from: TheMG on August 08, 2020, 07:15:01 pmI would tryQwest Components. I know they are a bit expensive but I wouldn't trust E-bay unless American seller.Mouser is an authorized Intel reseller but they have none in-stock.

author: aqibi2000
author_rank: Regular Contributor
timestamp: August 09, 2020, 02:18:45 pm
content: With it being a Microprocessor it would need programmingUnless it’s just a transceiverHmmm

author: TheMG
author_rank: Frequent Contributor
timestamp: August 09, 2020, 07:33:28 pm
content: Quote from: aqibi2000 on August 09, 2020, 01:21:32 pmSo the new IC comes with pre-applied solder balls that are sufficient?Quote from: aqibi2000 on August 09, 2020, 02:18:45 pmFrom what I can understand of thedatasheetit appears as though the chip gets its configuration information from an externally connected EEPROM upon initialization. I don't think it has any internally stored configuration, but I could be wrong. It's quite an extensive datasheet.I hope I'm right about this otherwise this whole thing will be a futile exercise...

author: aqibi2000
author_rank: Regular Contributor
timestamp: August 09, 2020, 09:38:19 pm
content: Ideally I would reball the supplied chipset with leaded solder balls which will help keep temperatures lower when reattaching. Every little helpsBest practice in this case would be to also remove any lead free solder and flood the pads with lead and then just wick it off. Else if you try and reflow use lead temperature some of the pads remain LF then the solder will not flow. Also the solder ball size is predetermined taking into account the pad size and therefore would be sufficient.The actual reason I said to remove the solder from the motherboard pads is they will be uneven therefore when you positioned the pre-balled chip onto this it will not sit in alignment to the required position and will rock and go astray unless help with tweezers.It’s well worth the punt at the cost you’ve mentioned

author: TheMG
author_rank: Frequent Contributor
timestamp: August 09, 2020, 11:28:29 pm
content: The "GD" prefix part number is the leaded version. Lead-free would be "LU" prefix. So presumably if I get the GD82551ER it should have leaded solder balls already.

author: TheMG
author_rank: Frequent Contributor
timestamp: November 05, 2020, 07:28:27 pm
content: Well, I finally got the replacement IC I ordered on eBay.This went a lot better than I expected. I preheated the board a little to get it nice and warm, put some fresh flux on the pads, plopped the new pre-balled IC onto the board, and hit it with the hot air. Once the solder got hot enough to flow, the IC just magically settled right into place.Fired it up and it works! I'm able to access the device via the ethernet port yet again.