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Reply To: | TechNet E-Mail Forum. |
Date: | Thu, 8 Oct 1998 06:56:07 -0600 |
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Rod/Bill
I concur with those numbers as a worst case. Actually 20% max (5 - 10%
nom) can be pretty easily achieved with the correct thermal profiles and
the correct paste selection. Boiling point of the paste volatiles plays
a large part.
Jim Kittel
>-----Original Message-----
>From: Bill Davis [SMTP:[log in to unmask]]
>Sent: Wednesday, October 07, 1998 5:03 PM
>To: [log in to unmask]
>Subject: Re: [TN] Voiding in BGA
>
>Rod:
>The guidelines we have established here are as follows:
> Total combined voiding <25%
> Less than or equal to 3 separate voids
> No two voids can intersect, irrespective of size/percentage
>
>Another 2cents...
>
>> -----Original Message-----
>> From: Rod Martens [SMTP:[log in to unmask]]
>> Sent: Wednesday, October 07, 1998 2:48 PM
>> To: [log in to unmask]
>> Subject: Re: [TN] Voiding in BGA
>>
>> I've never seen an exact number for voiding, but would be interested
>> if anyone
>> does have one. As for personal experience, we have seen cases where a
>> single
>> large void or many small voids aligned at an interface negatively
>> impacted the
>> reliablility. Also, we saw a case where some degree of voiding
>> actually
>> increased the life of BGA's, most likely due to some sort of crack
>> arrest
>> mechanism. I would imagine that a good number for max. voiding would
>> need to
>> include not just % void, but also position in the joint.
>> My $0.02,
>> Rod Martens
>>
>> -----Original Message-----
>> From: Non-HP-FEiranova
>> /hp-ftcollins,[log in to unmask]
>> Sent: Wednesday, October 07, 1998 2:39 PM
>> To: Non-HP-TechNet /hp-ftcollins,[log in to unmask]
>> Cc: Non-HP-FEiranova
>> /hp-ftcollins,[log in to unmask]
>> Subject: [TN] Voiding in BGA
>>
>> To all:
>> Is there a specification to address the maximum voiding allowed
>> for PBGA and CBGA solder joints attached to FR-4 substrate ?
>> Can anybody share some personal experiences in this matter ?
>> Thanks
>>
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>> << File: [TN] Voiding in BGA.TXT >>
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