Dean,

We did many assemblies with the Westbond 7200's [which are likely no longer
available], but they worked very well when either manually dispensing
adhesive and placing die, or when using pre-adhesive screened substrates.
I've seen a few of them on the used equipment market - just keep on ticking.
Nothing against the others, if they appear to suit your clients needs.

If just picking and placing die, they should get 200-250 placements per
hour, best case.  All depends on design, die, etc.

With the proper substrate layout [visual cues/design rules] the operators
could easily get device location within +/- 0.002" of nominal.  Theta was
typically less than 2-5°, depending on size of die and relationship to die
attach pad.  All of this shows up very quickly at the automatic wirebonders,
if the devices are inconsistently placed!  

My recommendation is that when using any of the manual machines to keep your
mind open for fixturing that best suits the users situation.  For example,
we enlarged the 'work table' to prevent accidental fall-offs of the work
holders.  The standard work holder typically only held one 2x2" waffle pack.
We made some for holding 3 2x2's.  Also made some when working with vac
release gel packs.  Because of the throat of the machine, one could only use
[at most] 2 4x4" waffle packs, and that was rare because the substrates were
typically just as large.

Most of my eutectic work was done on more specialized machines that are no
longer available.  Recommend that the eutectic bonders have good collet
heating capability and offer [as a minimum] adjustable mechanical scrub of
the die collet, if not the option for ultrasonic scrub.  'Cover gas' and
'cover gas blanketing' gets a 'show me it works first' response.  Some end
up pulling more oxidizing air in then they exclude.  With oxidizing alloys,
a touch of ultrasonics does help to break up and disperse the oxides a bit.
Mechanical scrub can do the same thing, but is more operator sensitive.
Also somewhat dependent on nature of substrate - thick film vs plated  vs
vacuum metalized glazed substrates, for example.  Obviously, need good temp
control over stage heat too..  Depending on their flow and product, a good
pre-heat of regulated duration can also be a big plus. 

If you require extreme placement accuracy, such as for laser facet to fiber
alignment, we need to have an entirely different discussion.


Steve Creswick
Sr Associate - Balanced Enterprise Solutions
http://www.linkedin.com/in/stevencreswick
                         616 834 1883



-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Stadem, Richard D.
Sent: Monday, March 17, 2014 8:41 AM
To: [log in to unmask]
Subject: [TN] Die Bonders

I am looking at purchasing 3 or 4 manual die bonding machines. I do not have
much experience in this process. My client will be using them to perform
eutectic gold/tin die bonding immediately, but they know they will also be
using epoxy die bonding in the near future. Some of the machines we are
looking at are Hybond, Westbond, and Tresky, as an example. Let me know
which machines you recommend.
I am looking for recommendations from other experienced users. You folks
have served me very well when I purchased the plasma cleaning equipment and
wirebonders for these clients recently. We are now on the third and final
phase of purchasing, qualification, and production startup, and they are
working great!
Please send me any information offline by sending a response to this email;
[log in to unmask]<mailto:[log in to unmask]>

Thank you so much for any feedback you can provide.
dean

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