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BGA Baking in Reels?

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#53519

BGA Baking in Reels? | 1 February, 2008

I have never had this come up before. We have a customer that would like all their BGAs baked before production. No a problem, but one of them is in tape and reel. I don't know the temperature limits of tape and reel. Has anyone done this and at what temperatures? Any other info?

Thanks it's much appreciated.

B

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#53523

BGA Baking in Reels? | 1 February, 2008

Don't do it.!!!! Are you nucking futs?

Why is pre-bake required? Are you producing in high humidity? Is the package of the device poroues enough to suck in moisture?

Think, consider you will not get an even "bake", the outside of the reel will get hotter faster, meanwhile the inner core will still be cold. If baking is required, purchase in trays that are heat tolerant so you can safely bake without melting plastic all over your BGA's.

Don't use just any tray. Trays are labeled with temp in "C". Use the max. "C" tray for your bake cycle.

I've seen low heat trays used to bake 240 pin QFP. The mess was ugly and very expensive.

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#53524

BGA Baking in Reels? | 1 February, 2008

They have been having a lot of fallout and they believe it is one of the BGAs that is causing it. I tell all my customers that it is better to stay away from baking if possible and to practice proper storage techniques. But the thing is they insist on using the cheapest board house they can find. They are the only customer we have a problem with delam on. I keep telling them it is their boards, but they refuse to change vendors..instead they require I bake their boards and parts. I inspected every ball of the bgas we received today and found some defects from the manufacturer. Unidentified contaminants that brdige balls and deformed/flat balls and scratches. I am going to write it up in a report to give them when we deliver the assemblies. Also their BGA pad designs are non-uniform. This is why under the Xray the balls are all appear different sizes which makes the customer assume the paste print was insufficient. Some times their boards delam even after baking and sometimes they don't. They tell me they are storing them in a nitrogen cabinet now. I don't know...you can't polish a turd. I am not baking the bgas in the reel. We have a couple of customers that "always have problems" , but refuse to take advise from the people who have been building PCBs for 16years. We have other customers who have no problems at all. OUr processes are the same for both. Hmmmm.... Customers suck man :-)

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#53525

BGA Baking in Reels? | 1 February, 2008

We bake components in reels quite often using a low temp oven. If you look under JDEC standards they provide temps and baking times based off of the thickness of the part. The only problem with the low temp is that you could be looking at baking times up to and ecxceeding 30 days.

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#53529

BGA Baking in Reels? | 2 February, 2008

Operator: use http://www.jedec.org/DOWNLOAD/search/jstd033b.pdf

BillG: Sometimes, the recommended bake times are numbingly long, because the authors of J-STD-033 assumed that: * Component took-on a large amount of moisture * You want your component bone dry

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#53581

BGA Baking in Reels? | 6 February, 2008

We have some components on a reel that are 2.3 mm in thickness and need to be baked out. The reel has a warning not to exceed 50�C. According to J-STD-33, the proper bake out is 67 days @ 40�C.

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