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 ---------------------------------------------------------------------------------