HMC7229 Data Sheet
Rev. D | Page 14 of 16
MOUNTING AND BONDING TECHNIQUES FOR
MILLIMETER WAVE GaAs MMICs
Attach the HMC7229 directly to the ground plane eutectically
or with a conductive epoxy. To route the RF signal to and from the
HMC7229, use a 50 Ω microstrip transmission line on 0.127 mm
(0.005 inches) thick alumina, thin film substrates (see Figure 36).
RF GROUND P LANE
0.102mm ( 0.004") T HICK G aAs M M IC
RIBBON BOND
0.127mm ( 0.005") T HICK AL UM INA,
THIN FILM SUBSTRATE
0.076mm
(0.003")
14566-035
Figure 36. Routing RF Signals
To minimize the bond wire length, place microstrip substrates
as close to the HMC7229 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 HMC7229 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 HMC7229 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 HMC7229 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 HMC7229 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 HMC7229 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
HMC7229 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).