Data Sheet

ADRF5448

APPLICATIONS INFORMATION

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Rev. 0 | 13 of 14

DIE ASSEMBLY

An assembly diagram of the ADRF5448 is shown in Figure 24.

Figure 24. Die Assembly Diagram

The ADRF5448 is designed to have the optimum RF input and

output impedance match with 3 mil × 0.5 mil gold ribbon wire and 3

mil loop height typical. The bonding diagrams are shown in

Figure 25 and Figure 26. Alternatively, using multiple wire bonds

with equivalent inductance yields similar performance. For RF rout-

ing from the device, coplanar wave guide or microstrip transmission

lines can be used. No impedance matching is required on the

transmission line pad because the device is designed to match

internally to the recommended ribbon bond. A spacing of 3 mils

from the RF transmission line to the device edge is recommended

for optimum performance.

DC pads can be connected using standard 1 mil diameter wire by

keeping the wire lengths as short as possible to minimize the para-

sitic inductance. The DC pads are large enough to accommodate

ribbon bonds, if preferred.

All bonds must be thermosonically bonded at a nominal stage

temperature of 150°C, and a minimum amount of ultrasonic energy

must be applied to achieve reliable bonds.

The ADRF5448 is metalized on the backside, and the ground

connection can be done by attaching the device directly to the RF

ground plane using a conductive epoxy. In this case, connecting the

ground pads is optional; however, still recommended to ensure a

solid ground connection.

Figure 25. Bonding Diagram Top View

Figure 26. Bonding Diagram Side View

HANDLING, MOUNTING, AND EPOXY DIE

ATTACH

Keep devices in ESD protective sealed bags for shipment, and

store all bare die in a dry nitrogen environment.

For manual picking, it is a common practice to use a pair of

tweezers for GaAs devices. However, for die on carrier devices, the

use of a vacuum tool is recommended to avoid any damage on the

device substrate. Handle these devices in a clean environment, and

do not attempt to clean devices using liquid cleaning systems.

To attach the die with epoxy, apply an amount of epoxy to the

mounting surface so that a thin epoxy fillet is observed around

the perimeter of the chip after it is placed into position. Set epoxy

cure temperatures per the recommendations of the manufacturer

and the maximum ratings of the device to minimize accumulated

mechanical stress after assembly.