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application. Literat u re
h a s b e e n c i t e d w i t h
comparable applications
mainly in microf luidics.
The available literature is
not showing any application
of these technologies for
silicon die fixation on a
wafer substrate. The work
discussed in this article
has shown the eff icacy
of the photostructurable
adhesive for the application
under analysis. Bonding
parameters and adhesive
layout and thickness have Figure 10: Cross-section image showing the
Figure 9: Resulting die shear strength for full contact between the been varied in order to resulting shape of the adhesive layer for full contact
silicon die and the adhesive layer after curing with respect to the b e t t e r u nd e r s t a nd t he layout for 3.0N @ 220°C.
variation of bonding temperature and applied force. b o nd i n g p r o c e s s. T he adhesive material varies significantly
die bonded with 220°C and 3.0N is results were analyzed using showing less edge covering.
shown. The resulting shape of the die shear testing and cross-sectional For additional analysis, a higher
adhesive material varies from the imaging. Trends for the dependency sample count at each set point needs
results of the previous analysis. The between force and pressure could be to be applied and more set points
image in Figure 10 shows that the edge demonstrated using die shear testing. need to be defined. Additionally, the
of the silicon die is covered less, which Cross-sectional images of the first layout material has to be further analyzed (e.g.,
is caused by the lack of possibility for variation show a proper covering of the rheological measurement, differential
the material to deform as a result of the edges of the die for higher temperatures. scanning calorimetry [DSC] analysis,
applied pressure. For variation 2 the resulting shape of the

Discussion
It is shown that for variation 1, the
temperature is the main influencing
parameter on die shear strength. It
is clearly evident that a threshold
temperature needs to be applied in order
to achieve sufficient bond strength.
Because of the high spread of measured
values, a higher sample count and
more sub-steps need to be analyzed in
order to better describe the dependency
between bond strength and the applied
temperature and bonding force. For
full contact between the silicon die and
the adhesive layer (second layout), the
influence of temperature was much
lower, but overall shear values have
been much higher. The cross-sectional
images clearly show that the edge
covering is less for variation 2 when
compared to layout 1. In order to better
understand the flowing behavior of
the material, temperature-dependent
rheological measurements need to be
conducted in the future.

Summary E-Tec Interconnect AG, Mr. Pablo Rodriguez, Lengnau Switzerland
This article introduced a bonding Phone : +41 32 654 15 50, E-mail: p.rodriguez@e-tec.com
technology using a photostructurable
adhesive layer with a thickness range
of 10 to 20µm for a silicon die bonding

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