ADPA7002CHIP

Data Sheet

Rev. 0 | Page 22 of 23

MOUNTING AND BONDING TECHNIQUES FOR

MILLIMETER WAVE GaAs MMICS

Attach the die directly to the ground plane with conductive

epoxy (see the Handling Precautions section, Mounting section,

and Wire Bonding section for instructions).

Microstrip, 50 Ω transmission lines on 0.127 mm (5 mil) thick

alumina, thin film substrates are recommended to send the RF

to and from the chip. Raise the die 0.075 mm (3 mil) to ensure

that the surface of the die is coplanar with the surface of the

substrate.

Place the microstrip substrates as close to the die as possible to

minimize ribbon bond length. Typical die to substrate spacing

is 0.076 mm to 0.152 mm (3 mil to 6 mil). To ensure wideband

matching, a 15 fF capacitive stub is recommended to be placed

on the PCB board before the ribbon bond. See Figure 67 and

Figure 68 for details.

Figure 67. High Frequency Input Wideband Matching

Figure 68. High Frequency Output Wideband Matching

Handling Precautions

To avoid permanent damage to the die, follow these storage,

cleanliness, static sensitivity, transient, and general handling

precautions:



Place all bare die in either waffle or gel-based ESD

protective containers and then seal the die in an ESD

protective bag for shipment. After the sealed ESD

protective bag is opened, store all die in a dry nitrogen

environment.



Handle the chips in a clean environment. Do not attempt

to clean the chip using liquid cleaning systems.



Follow ESD precautions to protect against ESD strikes.



When the bias is applied, suppress instrument and bias

supply transients. Use a shielded signal and bias cables to

minimize inductive pickup.



Handle the chip along the edges with a vacuum collet or

with a sharp pair of tweezers. The chip surface has fragile

air bridges and must not be touched with a vacuum collet,

tweezers, or fingers.

Mounting

Before the epoxy die is attached to the ADPA7002CHIP, apply a

minimum amount of epoxy (must order separately) to the

mounting surface so that a thin epoxy fillet is observed around

the perimeter of the chip after it is placed into position. Cure

the epoxy per the schedule of the manufacturer.

Wire Bonding

RF bonds made with 0.003 inch × 0.0005 inch gold ribbon are

recommended to be used with the RF ports. These bonds must

be thermosonically bonded with a force between 40 g to 60 g.

DC bonds of 0.001 inch (0.025 mm) in diameter,

thermosonically bonded, are recommended for bond wire

connections. Create ball bonds with a force between 40 g to

50 g, and wedge bonds with a force between 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).

Alternatively, short (≤3 mil) RF bonds made with two 1 mil

wires can be used in place of the gold ribbon.

MMIC

PCB

50Ω

TRANSMISSION LINE

MATCHING STUB/BOND PAD

SHUNT CAPACITANCE = 15fF

3mil GOLD

RIBBON

3mil GAP

RFIN

MMIC

PCB

50Ω

TRANSMISSION LINE

MATCHING STUB/BOND PAD

SHUNT CAPACITANCE = 15fF

3mil GAP

RFOUT

3mil GOLD

RIBBON