Larry, if the part you are describing is what I think it is, with Pb90 columns similar to a PowerPC, it may be exempt from the RoHS lead ban!
I would check on that before I jump into needless reballing or stripping off columns and replacing with solder balls, etc.
Because it has a ceramic body, the CTE of the part is much lower than the CTE of a typical substrate, thus the need for the Pb90 columns to provide a modulus of elasticity, and that is why it was made with Pb90 columns that have a much higher elasticity than a short fat cheese loaf of hard tin or even Sn36.
Stripping off the columns and replacing them with balls or columns of a different alloy may (will) simply cause a loss of reliability over time if the delta CTE is great enough during operating conditions.
So check this all out before you attempt to do anything.
Qualify, qualify, qualify. The job you save may be your own.
But if you HAVE to perform some kind of reballing, Steve's suggestion of using SixSigma Services is the absolute way to go. Excellent company.
dean
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Larry Brophy
Sent: Friday, December 07, 2018 9:36 AM
To: [log in to unmask]
Subject: Re: [TN] Ceramic Column Grid Array
Steve,
You are an absolute gent.
Many thanks,
Larry
From: Steve Gregory <[log in to unmask]>
Sent: Friday, December 7, 2018 3:31 PM
To: [log in to unmask]; [log in to unmask]
Subject: Re: [TN] Ceramic Column Grid Array
Hi Larry,
You want to go to these guys: http://www.sixsigmaservices.com/
Steve
On Fri, Dec 7, 2018 at 8:18 AM Larry Brophy <[log in to unmask] <mailto:[log in to unmask]> > wrote:
Hi all,
I have a 484 pin Column Grid Array from Microsemi that I have to use for a
new project.
The problem is that Microsemi only do this part as a lead part and have no
plans to do a unleaded version.
I need a ROHS version.
Reballing BGAs, I understand and can get done, but I don't know anyone that
can redo column. Any ideas?
Many thanks,
Larry
--
Steve Gregory
Kimco Design and Manufacturing
Process Engineer
(208) 322-0500 Ext. -3133
<http://fileserver1.kimco.net/PublicDocs/KDMsig200.png>
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