July 2004
Jetting Pre-Applied Solder Ball Reinforcement
with the DispenseJet® DJ-9000
Carlsbad, CA - Asymtek has developed an improved
method for applying solder
ball reinforcement material to semiconductor packages
that can eliminate the need for dispensing secondary underfill
in printed circuit board assembly.
In this method, the DispenseJet®
DJ-9000 shoots a fluid stream of underfill adhesive as
small as 100 micrometers wide between balls on CSPs and other
BGA packages during the semiconductor packaging process. Other
methods of pre-applied underfill have resulted in contaminating
the solder balls, or have been too costly to ramp into production.
Jetting the underfill prior to board assembly without contaminating
the solder balls allows semiconductor packaging companies
to offer packages with improved reliability without the cost
of traditional underfilling.
Typically, CSPs or other BGA packages require adhesive underfill
to glue the component rigidly to the printed circuit board
assembly to prevent failures due to shock. If the primary
failure of a non-underfilled CSP or other BGA package occurs
at the ball-package interface, the pre-applied solder ball
reinforcement reduces the probability of joint failure at
that interface. The cured reinforcement material relieves
the stress at the ball-substrate interface by reducing the
geometric stress concentration factor at that point. Therefore,
the solder joint withstands more load during shock-loading
or thermal cycling.
Asymtek supplies award-winning automated fluid dispensing
systems, specializing in semiconductor, surface mount, and
electronics packaging applications. With over 20 years of
experience, Asymtek is committed to providing innovative dispensing
solutions and the best support to customers worldwide. Find
out more at: http://www.asymtek.com.
|
