[Fwd: Re: Breaking wafers?]

Eric Tao erictao at stanford.edu
Wed Sep 8 15:31:47 PDT 2004


Just to echo this, I diced my wafers 3 times in the past month and it never 
happened to me either. All I did was just strictly following the 
instruction. However, increasing the dicing distance sounds reasonable to 
solve this "random" problem since it doesn't hurt.

-eric


At 03:24 PM 9/8/2004, afflannery at comcast.net wrote:

>Hi,
>
>
>
>Just for the record, we've diced about 5 wafers in the last 6 weeks 
>setting the diameter between 105 and 110. We've not had a problem with 
>breaking.
>
>I think the reason the blade sets down in the middle of the wafer is that 
>it thinks that it is the top. If you look at the pattern of dicing when 
>this happen, the edges of the incomplete cuts form a circle. I think it 
>gets confused as to its Y location relative to the wafer when you do your 
>alignment on a dicing lane at the edge, not in the center. I may make my 
>first cut at the edge, but I always align to a dicing lane in the center.
>
>Just my $0.02, and that's about all it is worth.
>
>
>
>Tony
>
>
>
>-------------- Original message --------------
>
> > Hi everyone!
> >
> > Thanks for your inputs! I think Karl has provided the historical
> > perspective, and explains why a larger diameter is useful. So, I'll
> > change the operating procedure to reflect these inputs (with the
> > recommendation to run at 150 mm, whatever the substrate size,
> > recognizing that this negates the entry speed feature). By the way,
> > this morning I tried using 200 mm as suggested by some, but it seems
> > that the stage sometimes gets stuck because it's hit a limit switch - so
> > based on this, I think 150 mm might be better (please let me know if
> > your experience suggests otherwise!)
> >
> > Thanks again --
> >
> > Mary
> >
> >
> > -------- Original Message --------
> > Subject: Re: Breaking wafers?
>! > Date: Tue, 7 Sep 2004 17:38:15 -0700 (PDT)
> > From: Karl Brandt
> > To: Mary Tang
> >
> >
> > Believe it or not, this was a problem from the first day we got the tool
> > from K&S. After repeated attempts by K&S to resolve it, they finally
> > threw
> > up their hands and said they simply had no idea what was wrong or how to
> > fix it. The accepted workaround has been to set the wafer diameter to
> > some
> > large diameter.
> >
> > -Karl
> >
> > *********************************************************************
> > Karl Brandt
> > http://people.ucsc.edu/~kbrandt/
> >
> >
> > On Tue, 7 Sep 2004, Mary Tang wrote:
> >
> > > Hi everyone --
> > >
> > > "rosti" dropped by my office to say that he was thinking about using the
> > > wafersaw, but was concerned about a problem he h! ad experienced a 
> couple
> > > of times in which the saw BROKE his wafer. He says that instead of
> > > starting on the edge, in these instances, the saw blade dropped onto the
> > > middle of the wafer and thus broke his wafers. The last instance that
> > > he observed was some time back last October or so.
> > >
> > > Now I'm worried! Usually, when a wafer is ready for dicing, you've
> > > expended a lot of time and energy into it -- you simply can't afford to
> > > have it smashed. I'm also really concerned because I've been training
> > > on the wafersaw for a couple of years now, but have not observed this
> > > problem nor had I heard about it from anyone (and here I thought I knew
> > > all the machine's quirks). I had heard that it used to be a problem,
> > > but not seen since the system was basically rebuilt a few years ago.
> > > Now, I'm hearing otherwise...
> > >
> > > Has anyone else had this problem? If so, coul! d you let me know
> > > approximately when it happened and how often (if you were "lucky", like
> > > rosti, and got hit more than once?) And maybe even the circumstances
> > > when it occurred (if you remember). Your feedback will help us decide
> > > what to do (if the darned thing is breaking wafers intermittently, we
> > > may need to take it off-line...)
> > >
> > > And, most importantly, if you observe this or any other problem, please,
> > > please, please report it on Coral! (I'm going back several years, and
> > > don't happen to see anything about the machine breaking wafers...)
> > >
> > > Thanks,
> > >
> > > Mary
> > >
> > >
> > > --
> > > Mary X. Tang, Ph.D.
> > > Stanford Nanofabrication Facility
> > > CIS Room 136, Mail Code 4070
> > > Stanford, CA 94305
> > > (650)723-9980
> > > mtang@! stanford.edu
> > > http://snf.stanford.edu
> > >
>&
>
>gt; >
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://snf.stanford.edu/pipermail/wafersaw/attachments/20040908/d90a241d/attachment.html>


More information about the wafersaw mailing list