<s>
The	O
wafer	B-Algorithm
bond	I-Algorithm
characterization	I-Algorithm
is	O
based	O
on	O
different	O
methods	O
and	O
tests	O
.	O
</s>
<s>
Considered	O
a	O
high	O
importance	O
of	O
the	O
wafer	B-Architecture
are	O
the	O
successful	O
bonded	O
wafers	B-Architecture
without	O
flaws	O
.	O
</s>
<s>
The	O
bond	O
connection	O
is	O
characterized	O
for	O
wafer	B-Architecture
bond	O
development	O
or	O
quality	O
assessment	O
of	O
fabricated	O
wafers	B-Architecture
and	O
sensors	O
.	O
</s>
<s>
Wafer	B-Architecture
bonds	O
are	O
commonly	O
characterized	O
by	O
three	O
important	O
encapsulation	O
parameters	O
:	O
bond	O
strength	O
,	O
hermeticity	O
of	O
encapsulation	O
and	O
bonding	O
induced	O
stress	O
.	O
</s>
<s>
The	O
image	O
contrast	O
depends	O
on	O
the	O
distance	O
between	O
the	O
wafers	B-Architecture
.	O
</s>
<s>
Usually	O
if	O
using	O
monochromatic	O
color	O
IR	O
the	O
center	O
of	O
the	O
wafers	B-Architecture
is	O
display	O
brighter	O
based	O
on	O
the	O
vicinity	O
.	O
</s>
<s>
Deionized	O
water	O
is	O
used	O
as	O
the	O
acoustic	O
interconnect	O
medium	O
between	O
the	O
electromagnetic	B-Algorithm
acoustic	I-Algorithm
transducer	I-Algorithm
and	O
the	O
wafer	B-Architecture
.	O
</s>
<s>
This	O
method	O
works	O
with	O
an	O
ultrasonic	O
transducer	O
scanning	O
the	O
wafer	B-Architecture
bond	O
.	O
</s>
<s>
A	O
blade	O
of	O
a	O
specific	O
thickness	O
is	O
inserted	O
between	O
the	O
bonded	O
wafer	B-Architecture
pair	O
.	O
</s>
<s>
If	O
the	O
fracture	O
surface	O
toughness	O
is	O
very	O
high	O
,	O
it	O
is	O
very	O
difficult	O
to	O
insert	O
the	O
blade	O
and	O
the	O
wafers	B-Architecture
are	O
endangered	O
to	O
break	O
at	O
the	O
slide	O
in	O
of	O
the	O
blade	O
.	O
</s>
<s>
In	O
addition	O
,	O
the	O
measurement	O
inaccuracy	O
increases	O
with	O
a	O
high	O
surface	O
fracture	O
toughness	O
resulting	O
in	O
a	O
smaller	O
crack	O
length	O
or	O
broken	O
wafers	B-Architecture
at	O
the	O
blade	O
insertion	O
as	O
well	O
as	O
the	O
influence	O
of	O
the	O
fourth	O
power	O
of	O
the	O
measured	O
crack	O
length	O
.	O
</s>
<s>
Thereby	O
is	O
the	O
Young	O
's	O
modulus	O
,	O
the	O
wafer	B-Architecture
thickness	O
,	O
the	O
blade	O
thickness	O
and	O
the	O
measured	O
crack	O
length	O
.	O
</s>
<s>
It	O
is	O
commonly	O
used	O
to	O
characterize	O
the	O
wafer	B-Architecture
bond	O
strength	O
as	O
well	O
as	O
the	O
reliability	O
.	O
</s>
<s>
It	O
is	O
an	O
effective	O
,	O
reliable	O
and	O
precise	O
approach	O
for	O
the	O
development	O
of	O
wafer	B-Architecture
bonds	O
as	O
well	O
as	O
for	O
the	O
quality	O
control	O
of	O
the	O
micro	O
mechanical	O
device	O
production	O
.	O
</s>
<s>
Both	O
can	O
be	O
done	O
destructively	O
,	O
which	O
is	O
more	O
common	O
(	O
also	O
on	O
wafer	B-Architecture
level	O
)	O
,	O
or	O
non	O
destructively	O
.	O
</s>
<s>
To	O
pull	O
a	O
bond	O
requires	O
the	O
substrate	B-Architecture
and	O
interconnect	O
to	O
be	O
gripped	O
;	O
because	O
of	O
size	O
,	O
shape	O
and	O
material	O
properties	O
,	O
this	O
can	O
be	O
difficult	O
,	O
particularly	O
for	O
the	O
interconnection	O
.	O
</s>
<s>
applies	O
an	O
upward	O
force	O
under	O
the	O
wire	O
,	O
effectively	O
pulling	O
it	O
away	O
from	O
the	O
substrate	B-Architecture
or	O
die	O
.	O
</s>
<s>
White	O
light	O
interferometry	O
is	O
commonly	O
used	O
for	O
detecting	O
deformations	O
of	O
the	O
wafer	B-Architecture
surface	O
based	O
on	O
optical	O
measurements	O
.	O
</s>
<s>
Low-coherence	O
light	O
from	O
a	O
white	O
light	O
source	O
passes	O
through	O
the	O
optical	O
top	O
wafer	B-Architecture
,	O
e.g.	O
</s>
<s>
glass	O
wafer	B-Architecture
,	O
to	O
the	O
bond	O
interface	O
.	O
</s>
<s>
White	O
light	O
interferometry	O
is	O
utilized	O
to	O
detect	O
deformations	O
of	O
the	O
wafer	B-Architecture
.	O
</s>
<s>
Low	O
coherence	O
light	O
from	O
a	O
white	O
light	O
source	O
passes	O
through	O
the	O
top	O
wafer	B-Architecture
to	O
the	O
sensor	O
.	O
</s>
