Alumina comes in various grades from white to black.The colour comes from the additives used to
sinter the alumina.Today I saw some beautiful blue material, it had been processed with some
cobalt salts but this is not a usual condition.
Normal colours are
As noted in [volume] packaging applications - usually involving high temperature co-firing - it
is a coffee brown colour.
In hybrid thick film applications, lower volume and low temperature co-fire white alumina is the
norm.
Black alumina is used in opto-electronic/display applications.


Mike


----- Original Message -----
From: Phil Crepeau <[log in to unmask]>
To: <[log in to unmask]>
Sent: Tuesday, February 29, 2000 3:26 PM
Subject: Re: [TN] Color of ceramic BGA's


> hi,
>
> not all alumina packages are white.  we use many alumina packages that are brownish.  you may
say that there is something other than aluminal in these packages that make them brownish, but
the fact is that in this industry, when you say a package is alumina, it doesn't mean it's
white.
>
> phil
>
> -----Original Message-----
> From: Carey Pico [mailto:[log in to unmask]]
> Sent: Monday, February 28, 2000 9:30 PM
> To: [log in to unmask]
> Subject: Re: [TN] Color of ceramic BGA's
>
>
> Of course.  Alumina is white
>
> Carey
>
> -----Original Message-----
> From: d. terstegge <[log in to unmask]>
> To: [log in to unmask] <[log in to unmask]>
> Date: Monday, February 28, 2000 8:54 AM
> Subject: [TN] Color of ceramic BGA's
>
>
> Hi Technetters,
>
> During acceptance testing of our new pick&place machine we ran into a
> problem: the vision system can't see the solderballs on the white ceramic
> substrate of our Topline dummy-CBGA's. It's just not supported.
> I have never used CBGA's in our production, and I was wondering if real-life
> CBGA's can have this same color.
>
> Kind regards
>
> Daan Terstegge
> Unclassified mail
> Personal website: http://surf.to/smtinfo
>
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