HMC7229CHIPS Datasheet, PDF (13/16 Pages) Analog Devices – Point to point radios

Data Sheet
HMC7229CHIPS
APPLICATIONS INFORMATION
MOUNTING AND BONDING TECHNIQUES FOR
MILLIMETER WAVE GaAs MMICs
Attach the HMC7229CHIPS directly to the ground plane
eutectically or with a conductive epoxy. To route the RF signal
to and from the HMC7229CHIPS, use a 50 Ω microstrip
transmission line on 0.127 mm (0.005 inches) thick alumina, thin
film substrates (see Figure 35).
0.102mm (0.004") THICK GaAs MMIC
0.076mm
(0.003")
RIBBON BOND
RF GROUND PLANE
0.127mm (0.005") THICK ALUMINA,
THIN FILM SUBSTRATE
Figure 35. Routing RF Signals
To minimize the bond wire length, place microstrip substrates
as close to the HMC7229CHIPS as possible. Typical chip to
substrate spacing is 0.076 mm to 0.152 mm (0.003 inches and
0.006 inches).
HANDLING PRECAUTIONS
To avoid permanent damage to the device, adhere to the following
precautions:
• All bare HMC7229CHIPS ship in either waffle or gel-based
ESD protective containers, sealed in an ESD protective bag.
After opening the sealed ESD protective bag, store all chips in
a dry nitrogen environment.
• Handle the HMC7229CHIPS in a clean environment.
Never use liquid cleaning systems to clean the chip.
• Follow ESD precautions to protect against ESD strikes.
• While applying bias, suppress instrument and bias supply
transients. To minimize inductive pickup, use shielded
signal and bias cables.
• Handle the HMC7229CHIPS along the edges with a vacuum
collet or a sharp pair of bent tweezers. The surface of the chip
has fragile air bridges and must not be touched with a vacuum
collet, tweezers, or fingers.
MOUNTING
The HMC7229CHIPS is back metallized and can be die mounted
onto a system with Au/Sn eutectic preforms or with electrically
conductive epoxy. The mounting surface must be clean and flat.
Eutectic Die Attach
It is best to use an 80% Au/20% Sn preform with a work surface
temperature of 255°C and a tool temperature of 265°C. When the
work surface is 255°C and tool temperature is 265°C, 90% nitrogen/
10% hydrogen gas is applied to the work surface, maintain the
tool tip temperature at 290°C. Do not expose the HMC7229CHIPS
to a temperature greater than 320°C for more than 20 sec. No
more than 3 sec of scrubbing is required for attachment.
Epoxy Die Attach
The ABLETHERM 2600BT is recommended for chip attachment.
Apply a minimum amount of epoxy to the mounting surface so
a thin epoxy fillet is observed around the perimeter of the
HMC7229CHIPS after placing the device into position on
the surface. Cure the epoxy per the schedule provided by the
manufacturer.
Wire Bonding
RF bonds made with 0.003 in. × 0.0005 in. Au ribbon are recom-
mended for the RF ports. These bonds must be thermosonically
bonded with a force of 40 g to 60 g. DC bonds of 1 mil (0.025 mm)
diameter, thermosonically bonded, are recommended. Create ball
bonds with a force of 40 g to 50 g and wedge bonds with a force of
18 g to 22 g. Create all bonds with a nominal stage temperature of
150°C. Apply a minimum amount of ultrasonic energy to achieve
reliable bonds. Keep all bonds as short as possible, less than 12 mil
(0.31 mm).
BIASING PROCEDURES
The basic connections for operating the HMC7229CHIPS are
shown in the Typical Application Circuit section and the Theory
of Operation section. The RF input and RF output are ac-coupled
by internal dc block capacitors. Follow the recommended bias
sequencing to avoid damaging the amplifier.
The amplifier gate bias can be supplied using either the VGG1 pin
or VGG2 pin. Use the VDD1 to VDD8 pins while applying the drain bias
to the amplifier. Testing to gather data for the HMC7229CHIPS
data sheet used the VGG1 pin with the VDD1 to VDD8 pins connected
together.
Use the following recommended bias sequence during power-up:
1. Connect GND to RF/dc ground.
2. Set VGG1 or VGG2 to −2 V.
3. Set VDD1 to VDD8 to 6 V.
4. Increase VGG1 or VGG2 to achieve a typical IDQ = 1200 mA.
5. Apply an RF signal the device.
Use the following recommended bias sequence during power-
down:
1. Turn off the RF signal
2. Decrease VGG1 or VGG2 to −2 V to achieve IDQ = 0 mA.
3. Decrease VDD1, VDD2, VDD3, and VDD4 to 0 V.
4. Increase VGG1 or VGG2 to 0 V.
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