MICROWAVE CORPORATION

5 - 80

For price, delivery, and to place orders, please contact Hittite Microwave Corporation:

12 Elizabeth Drive, Chelmsford, MA 01824 Phone: 978-250-3343 Fax: 978-250-3373

Order Online at www.hittite.com

5

HMC294

v01.0300

MIC Assembly Techniques

Mounting & Bonding Techniques for Millimeterwave GaAs MMICs

The die should be attached directly to the ground plane eutectically or with conductive epoxy (see HMC general Handling, Mounting,

Bonding Note).

50 Ohm Microstrip transmission lines on 0.127mm (5 mil) thick alumina thin film substrates are recommended for bringing RF to and

from the chip (Figure 1). If 0.254mm (10 mil) thick alumina thin film substrates must be used, the die should be raised 0.150mm (6

mils) so that the surface of the die is coplanar with the surface of the substrate. One way to accomplish this is to attach the 0.102mm (4

mil) thick die to a 0.150mm (6 mil) thick molybdenum heat spreader (moly-tab) which is then attached to the ground plane (Figure 2).

Microstrip substrates should be brought as close to the die as possible in order to minimize bond wire length. Typical die-to-substrate

spacing is 0.076mm (3 mils). Gold ribbon of 0.076 mm x 0.013 mm (3 mil x 0.5 mil) and minimal length <0.31 mm (<12 mils) is recom-

mended to minimize inductance on the RF ports.

Ribbon Bond

Ribbon Bond

GaAs MMIC DOUBLE-BALANCED

MIXER, 25 - 40 GHz