HMC404 View Datasheet(PDF) - Hittite Microwave

Part Name

Description

Manufacturer

HMC404

GaAs MMIC SUB-HARMONICALLY PUMPED IRM MIXER, 26 - 33 GHz

Hittite Microwave 

v03.0907

HMC404

GaAs MMIC SUB-HARMONICALLY

PUMPED IRM MIXER, 26 - 33 GHz

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).

0.102mm (0.004”) Thick GaAs MMIC

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

0.076mm

(0.003”)

3 mil Ribbon Bond

3

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).

RF Ground Plane

Microstrip substrates should be brought as close to the die as possible in order

to minimize ribbon bond length. Typical die-to-substrate spacing is 0.076mm (3

mils). Gold ribbon of 0.075 mm (3 mil) width and minimal length <0.31 mm (<12

mils) is recommended to minimize inductance on RF, LO & IF ports.

An RF bypass capacitor should be used on the Vdd input. A 100 pF single layer

capacitor (mounted eutectically or by conductive epoxy) placed no further than

0.762mm (30 Mils) from the chip is recommended.

0.127mm (0.005”) Thick Alumina

Thin Film Substrate

Figure 1.

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.

0.102mm (0.004”) Thick GaAs MMIC

0.076mm

(0.003”)

3 mil Ribbon Bond

RF Ground Plane

0.150mm (0.005”) Thick

Moly Tab

0.254mm (0.010”) Thick Alumina

Thin Film Substrate

Figure 2.

Mounting

The chip is back-metallized and can be die mounted with AuSn eutectic preforms or with electrically conductive epoxy. The mounting

surface should be clean and flat.

Eutectic Die Attach: A 80/20 gold tin preform is recommended with a work surface temperature of 255 °C and a tool temperature

of 265 °C. When hot 90/10 nitrogen/hydrogen gas is applied, tool tip temperature should be 290 °C. DO NOT expose the chip

to a temperature greater than 320 °C for more than 20 seconds. No more than 3 seconds of scrubbing should be required for

attachment.

Epoxy Die Attach: Apply a minimum amount of epoxy to the mounting surface so that a thin epoxy fillet is observed around the

perimeter of the chip once it is placed into position. Cure epoxy per the manufacturer’s schedule.

Wire Bonding

RF bonds made with 0.003” x 0.0005” ribbon are recommended. These bonds should be thermosonically bonded with a force of

40-60 grams. DC bonds of 0.001” (0.025 mm) diameter, thermosonically bonded, are recommended. Ball bonds should be made

with a force of 40-50 grams and wedge bonds at 18-22 grams. All bonds should be made with a nominal stage temperature of 150

°C. A minimum amount of ultrasonic energy should be applied to achieve reliable bonds. All bonds should be as short as possible,

less than 12 mils (0.31 mm).

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

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