Josep,
Steve does make a point. I did not address heavy Al wire bonding since you
did not make reference to it, however, I do not see what advantage oxygen
and moisture in a non-nitrogen, non-hermetic environment would bring to the
table as Steve suggests... perhaps he will enlighten us both.
Regards,
Bruce
> ----------
> From: Creswick[SMTP:[log in to unmask]]
> Reply To: TechNet E-Mail Forum.;Creswick
> Sent: Monday, March 05, 2001 11:25 AM
> To: [log in to unmask]
> Subject: Re: [TN] Al wire bonding
>
> Josep,
>
> You did not define two critial parameters - wire size, and how many you
> plan
> to do!
>
> I beg to differ with Bruce's response a bit.
>
> Fine wire aluminum wire on clean copper does work, although I much prefer
> the nickel plating too!
>
> Fine wire aluminum (1.25 - 2 mil) IS challenging! Normal Al wire doesn't
> work very consistently - it is too soft. One obtains too much bond
> deformation before a 'real' bond is formed. The trick is to use 'harder'
> wire (lower elongation), but then the problem shifts to problems of
> damaging
> the IC's bond pads. If you are not very experienced at wire bonding, this
> could be daunting!
>
> Specificially, heavy aluminum (5-10 mil diameter) works REALLY WELL on
> copper - its only 'fault' is that it must be operated in an non-nitrogen
> (ie. non-hermetic) environment to retain good pull strengths.
>
> Conclusions: If you have a couple parts to do, you might struggle though
> as
> suggested above. If you have large numbers of parts to do, make it easier
> on yourself (as Bruce suggests) and get them plated! (But I suggest that
> you test some sample plated parts before you plate up everything)
>
> PS - In many respects, automatic wire bonding is still an 'art', although
> science helps out at times.
>
> And I can honestly say that the views expressed above are NOT those of my
> employer.
>
>
> Steven Creswick
>
>
>
>
>
> At 01:41 PM 3/5/01 +0100, you wrote:
> >I'm unable to make a wire ultrasonic bonding (wedge bond) with Al wire
> >directly to cupper pad.
> >With your permission, I'd be interested to known if this bonding is
> possible
> >
> >Thanks in advanced
> >
> >
> >Josep M. Badia
> >Servei de Recursos Tècnics
> >Tèlf/Fax: 977 559630/559605
> >Univ. Rovira i Virgili
> >
> >-------------------------------------------------------------------------
> --
> ------
> >Technet Mail List provided as a free service by IPC using LISTSERV 1.8d
> >To unsubscribe, send a message to [log in to unmask] with following text in
> >the BODY (NOT the subject field): SIGNOFF Technet
> >To temporarily halt delivery of Technet send the following message: SET
> Technet NOMAIL
> >Search previous postings at: www.ipc.org > On-Line Resources & Databases
> >
> E-mail Archives
> >Please visit IPC web site (http://www.ipc.org/html/forum.htm) for
> additional
> >information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700
> ext.5315
> >-------------------------------------------------------------------------
> --
> ------
> >
> >
>
> --------------------------------------------------------------------------
> -------
> Technet Mail List provided as a free service by IPC using LISTSERV 1.8d
> To unsubscribe, send a message to [log in to unmask] with following text in
> the BODY (NOT the subject field): SIGNOFF Technet
> To temporarily halt delivery of Technet send the following message: SET
> Technet NOMAIL
> Search previous postings at: www.ipc.org > On-Line Resources & Databases >
> E-mail Archives
> Please visit IPC web site (http://www.ipc.org/html/forum.htm) for
> additional
> information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700
> ext.5315
> --------------------------------------------------------------------------
> -------
>
---------------------------------------------------------------------------------
Technet Mail List provided as a free service by IPC using LISTSERV 1.8d
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF Technet
To temporarily halt delivery of Technet send the following message: SET Technet NOMAIL
Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives
Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315
---------------------------------------------------------------------------------
|
