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

20 Alpha Road, Chelmsford, MA 01824 Phone: 978-250-3343 Fax: 978-250-3373

Order On-line at www.hittite.com

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 brought as close to the die as possible in

order to minimize bond wire length. Typical die-to-substrate spacing is

0.076mm to 0.152 mm (3 to 6 mils).

RF bypass capacitors should be used on the Vdd & Vgg inputs. 100pF

single layer capacitors (mounted eutectically or by conductive epoxy)

placed no further than 0.762 mm (30 mils) from the chip are recommended.

The photo in figure 3 shows a typical assembly for the HMC283 MMIC

chip.

0.102mm (0.004”) Thick GaAs MMIC

Ribbon Bond

RF Ground Plane

0.127mm (0.005”) Thick Alumina

Thin Film Substrate

0.076mm

(0.003”)

Figure 1.

0.102mm (0.004”) Thick GaAs MMIC

Ribbon Bond

RF Ground Plane

0.254mm (0.010”) Thick Alumina

Thin Film Substrate

0.076mm

(0.003”)

Figure 2.

0.150mm (0.005”) Thick

Moly Tab

HMC283

v03.1007

GaAs MMIC MEDIUM POWER

AMPLIFIER, 17 - 40 GHz

Figure 3: Typical HMC283 Assembly

Handling Precautions

Follow these precautions to avoid permanent damage.

Storage: All bare die are placed in either Waffle or Gel based ESD protective containers, and then sealed in an ESD

protective bag for shipment. Once the sealed ESD protective bag has been opened, all die should be stored in a dry

nitrogen environment.

Cleanliness: Handle the chips in a clean environment. DO NOT attempt to clean the chip using liquid cleaning

systems.

Static Sensitivity: Follow ESD precautions to protect against ESD strikes.

Transients: Suppress instrument and bias supply transients while bias is applied. Use shielded signal and bias

cables to minimize inductive pick-up.

General Handling: Handle the chip along the edges with a vacuum collet or with a sharp pair of bent tweezers. The

surface of the chip has fragile air bridges and should not be touched with vacuum collet, tweezers, or fingers.