Biasing and Operation
Assembly Techniques
Thermosonic wedge bonding is
the preferred method for wire
attachment to the bond pads.
Gold mesh can be attached
using a 2 mil round tracking
tool and a tool force of
approximately 22 grams with an
ultrasonic power of roughly 55
dB for a duration of 76 8 mS.
A guided wedge at an ultrasonic
power level of 64 dB can be
used for the 0.7 mil wire. The
recommended wire bond stage
temperature is 150 2 °C.
The AMMC-5620 is normally
biased with a single positive
drain supply connected to the
The backside of the AMMC-5620
chip is RF ground. For
microstripline applications, the
chip should be attached directly
to the ground plane (e.g., circuit
V
bond pads shown in Figure
DD
19. The recommended supply
voltage is 5 V, which results in
carrier or heatsink) using
electrically conductive epoxy
[1]
I
= 95 mA (typical).
.
DD
No ground wires are required
because all ground connections
are made with plated through-
holes to the backside of the
device.
For best performance, the
topside of the MMIC should be
brought up to the same height
as the circuit surrounding it.
This can be accomplished by
mounting a gold plated metal
shim (same length and width as
the MMIC) under the chip,
which is of the correct
Refer the Absolute Maximum
Ratings table for allowed DC
and thermal conditions.
Caution should be taken to not
exceed the Absolute Maximum
Rating for assembly temperature
and time.
thickness to make the chip and
adjacent circuit coplanar.
The chip is 100 µm thick and
should be handled with care.
This MMIC has exposed air
bridges on the top surface and
should be handled by the edges
or with a custom collet (do not
pick up die with vacuum on die
center.)
The amount of epoxy used for
chip and or shim attachment
should be just enough to
provide a thin fillet around the
bottom perimeter of the chip or
shim. The ground plane should
be free of any residue that may
jeopardize electrical or
mechanical attachment.
This MMIC is also static
sensitive and ESD handling
precautions should be taken.
The location of the RF bond
pads is shown in Figure 20.
Note that all the RF input and
output ports are in a Ground-
Signal-Ground configuration.
Notes:
1. Ablebond 84-1 LM1 silver epoxy is
recommended.
2. Buckbee-Mears Corporation, St. Paul, MN,
800-262-3824
RF connections should be kept
as short as reasonable to
minimize performance
degradation due to undesirable
series inductance. A single bond
wire is sufficient for signal
connections, however double-
bonding with 0.7 mil gold wire
[2]
or the use of gold mesh is
recommended for best
performance, especially near the
high end of the frequency range.
6