Hi Vlad - what data do you have that 10 micron thick layer of IMC results
in the failure of the BGA? There is TONS of subjective comments in the
published literature but no hard data of failures. As a basic materials
engineering principle, IMCs are brittle but that specific material
characteristic seems to be the only reason folks make statements that a
"thick" IMC is bad. Should we work to keep IMC layers minimized? Absolutely
but I don't believe, as technologists, we should keep propagating the myth
about thick IMC layers without having published, reviewable data.

Dave Hillman
Rockwell Collins
[log in to unmask]

On Wed, Sep 16, 2015 at 9:38 AM, Vladimir Igoshev <
[log in to unmask]> wrote:

> 10 microns thick layer is a perfect way for a disaster down the road :-).
>
> There are no parameters for E-Ni, but the appearance of the interface and
> a P-enriched layer ‎is important.
>
> Vladimir
>
> Sent from my BlackBerry 10 smartphone on the Rogers network.
>   Original Message
> From: Victor Hernandez
> Sent: Wednesday, September 16, 2015 10:11
> To: [log in to unmask]
> Reply To: TechNet E-Mail Forum
> Subject: Re: [TN] BGA Reworked Intermetallic
>
> On ENIG surface I don't see much of an increase in the IMC formation
> thickness. However, on Cu it is a different story. I have measured IMC
> formation greater tham 10 microns. Not sure of the below statement about
> E-NI parameter. Please explain!!!
>
> Victor,
>
> -----Original Message-----
> From: TechNet [mailto:[log in to unmask]] On Behalf Of Vladimir Igoshev
> Sent: Wednesday, September 16, 2015 8:12 AM
> To: [log in to unmask]
> Subject: Re: [TN] BGA Reworked Intermetallic
>
> The "magic" Number should stay the same 1-3 micron but you'd also have to
> keep an eye on what happened to the layer of E-Ni underneath.
>
> Regards,
>
> Vladimir
>
> SENTEC
>
> Sent from my BlackBerry 10 smartphone on the Rogers network.
> Original Message
> From: Datacom - Juliano Ribeiro
> Sent: Wednesday, September 16, 2015 09:09
> To: [log in to unmask]
> Reply To: TechNet E-Mail Forum
> Subject: [TN] BGA Reworked Intermetallic
>
> Hi to all,
>
>
>
> When we reworked the BGA, removed the component of the board and
> replacement another BGA, what's the intermetallic thickness ideal after the
> rework?
>
>
>
> p.s: Our pcb is ENIG finished and the solder is Tin Lead.
>
>
>
> _____________________________
>
> Juliano Bettim Ribeiro
>
> DATACOM
>
> ENGENHARIA DE PROCESSOS
> Rua América Nº 1000 - Eldorado do Sul - RS CEP: 92990-000
> +55 (51) 8446-2135
>
> +55 (51) 3933-3000
>
> Ramal: 3484
> [log in to unmask] www.datacom.ind.br
>
>
>
>
> ______________________________________________________________________
> This email has been scanned by the Symantec Email Security.cloud service.
> For more information please contact helpdesk at x2960 or [log in to unmask]
> ______________________________________________________________________
>
> ______________________________________________________________________
> This email has been scanned by the Symantec Email Security.cloud service.
> For more information please contact helpdesk at x2960 or [log in to unmask]
> ______________________________________________________________________
>
> ______________________________________________________________________
> This email has been scanned by the Symantec Email Security.cloud service.
> For more information please contact helpdesk at x2960 or [log in to unmask]
> ______________________________________________________________________
>
> ______________________________________________________________________
> This email has been scanned by the Symantec Email Security.cloud service.
> For more information please contact helpdesk at x2960 or [log in to unmask]
> ______________________________________________________________________
>

______________________________________________________________________
This email has been scanned by the Symantec Email Security.cloud service.
For more information please contact helpdesk at x2960 or [log in to unmask] 
______________________________________________________________________