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Lead free BGA on a Leaded Process


CL

#31700

Lead free BGA on a Leaded Process | 14 December, 2004

Good Morning Everyone,

I had a question regarding the use of a lead free BGA in a leaded process. All of the information I have gathered from various seminars state that this is OK. It will process more like a column grid array where the 63/37 will form the interconnection between the PCB pad and the BGA ball. The idea is that the ball will not become liquidous so there is a transition of materials that form the interconnect. Yesterday, a customer visited to discuss out Lead Free roadmap. They stated that they have reliability data that shows that this is not acceptable. Has anyone else heard or know of any data that supports this statement? Any help would be greatly appriciated.

Thanks In Advance

Chris

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Guest

#31713

Lead free BGA on a Leaded Process | 14 December, 2004

Yes, the (large) company where I work has the policy not to use leadfree BGA's in the "old" process, so it's not unusual. Be prepared to have more customers having this opinion.

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T2

#31841

Lead free BGA on a Leaded Process | 26 December, 2004

Chris,

We also do not allow the use of Lead-Free BGAs in a lead based process. It is actually one of the things that scares us most about converting to Pb-free.

Most of the suppliers that we have talked with are planning on moving to the SAC alloy for their BGA devices. Some of these suppleirs (like Freescale) are only offering SAC alloy BGAs for all of their new products. The SAC alloy has a liquidous temperature of 218C. So if you are running your 'standard' leaded process, and are trying to hit a peak reflow temp of 230C and hold it for 45-60 seconds, chances are a portion of the balls on a SAC alloy BGA may go liquidous. Obviously if they all don't go liquidous, there are going to be problems and reliability concerns.

The conversion to Lead-free, the WEEE and RoHS directives have to be the biggest issues that the electronics industry has had to come to terms with in the last 15-20 years. if you think that your industry is exempt from moving to Pb-free, you better start grilling your supply base to make sure that they will continue to supply your components (primarily BGAs) in lead based packages.

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WDLau

#31879

Lead free BGA on a Leaded Process | 3 January, 2005

Hi All,

How about leadfree proces but with leaded BGA, please comment

WDLau

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#31900

Lead free BGA on a Leaded Process | 4 January, 2005

We've had several conversations about that here on SMTnet. Search the fine SMTnet Archives. For instance: http://www.smtnet.com/forums/Index.cfm?CFApp=1&Message_ID=30307

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WDLau

#32035

Lead free BGA on a Leaded Process | 13 January, 2005

Hi Dave,

Then you think it is ok to use leaded (Sn/Pb) BGA with Lead free solder paste (SAC)and reflow process,

As someone told it is not reliable and it should not be allowed to go,

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#32054

Lead free BGA on a Leaded Process | 13 January, 2005

It depends. Probably it's fine for consumer products.

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