Testing - Mil-Std-883 Method 2019
is the process of determining the strength of adhesion of a
semiconductor die to the package's die attach substrate (such as the die
pad of a lead frame or the cavity of a hermetic package), by subjecting
the die to a stress that's parallel to the plane of die attach substrate, resulting
in a shearing stress between: 1) the die-die attach material interface;
and 2) the die attach material-substrate interface.
purpose of die shear testing is to assess the over-all quality of the
process, including the integrity of the materials
and the capabilities of the processes used in mounting the die (and
other elements, if any) to the package substrate. Mil-Std-883
Method 2019 is the most widely-used industry standard for performing
die shear tester
consists of: 1) a
mechanism that applies the correct load to the die with an accuracy of
+/- 5% of full scale or 50 g, whichever tolerance is greater; 2) a die
contact tool which makes the actual contact with the full length of the
die edge to apply the force uniformly from one end of the edge to the
other; 3) provisions to ensure that the die contact tool is
perpendicular to the die attach plane; 4) provisions to ensure that the
fixture holding the die may be rotated with respect to the contact tool
so that the die edge and contact tool may always be aligned in parallel
to each other; and 5) a binocular microscope (10X min magnification) and
lighting system to facilitate the observation of the die and contact
tool while the test is being performed.
to the die during die shear testing must be sufficient to shear the die
from its mounting or twice the lower specification limit for the die
shear strength, whichever occurs first. The direction of the
applied force must be perpendicular to the die edge and parallel to the
die attach or substrate plane. After the initial contact has been made
and the application of force starts, the relative position of the tool
must not change vertically, i.e., it must be prevented from contacting
either the die attach material or the substrate.
from die shear testing include: 1) failure to meet the specified die
shear strength requirements; 2) a separation that occurs at less than
1.25X the minimum die shear strength and evidence of less than 50%
adhesion of the die attach material; and 3)
a separation that occurs at less than
2X the minimum die shear strength and evidence of less than 10% adhesion
of the die attach material.
mode of separation
must also be classified into and recorded as any of the following: 1)
shearing of the die itself with silicon remaining; 2) separation of the
die from the die attach material; and 3) separation of both the die and
die attach material from the package substrate.
The die shear strength requirements are
of Mil-Std-883 Method 2019.
Mil-Std-883 Methods; Package Failures
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