Datasheet HMC441 (Analog Devices) - 8

HMC441
v09.0917
GaAs pHEMT MMIC MEDIUM POWER AMPLIFIER, 6 - 18 GHz Mounting & Bonding Techniques for Millimeterwave GaAs MMICs
The die should be attached directly to the ground plane eutectical y 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 Wire Bond IP thin film substrates are recommended for bringing RF to and from the chip 0.076mm (0.003”) H (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 accom- plish this is to attach the 0.102mm (4 mil) thick die to a 0.150mm (6 mil) S - C thick molybdenum heat spreader (moly-tab) which is then attached to the RF Ground Plane R ground plane (Figure 2). IE Microstrip substrates should be located as close to the die as possible in order to minimize bond wire length. Typical die-to-substrate spacing is 0.127mm (0.005”) Thick Alumina Thin Film Substrate LIF 0.076mm to 0.152 mm (3 to 6 mils). Figure 1. P
Handling Precautions
M Follow these precautions to avoid permanent damage. 0.102mm (0.004”) Thick GaAs MMIC
Storage:
All bare die are placed in either Waffle or Gel based ESD pro- Wire Bond R A tective containers, and then sealed in an ESD protective bag for shipment. 0.076mm E Once the sealed ESD protective bag has been opened, all die should be (0.003”) stored in a dry nitrogen environment. W O
Cleanliness:
Handle the chips in a clean environment. DO NOT attempt to clean the chip using liquid cleaning systems. RF Ground Plane
Static Sensitivity:
Fol ow ESD precautions to protect against > ± 250V ESD strikes. 0.150mm (0.005”) Thick Moly Tab R & P
Transients:
Suppress instrument and bias supply transients while bias is 0.254mm (0.010”) Thick Alumina A applied. Use shielded signal and bias cables to minimize inductive pick-up. Thin Film Substrate E Figure 2.
General Handling:
Handle the chip along the edges with a vacuum col et or with a sharp pair of bent tweezers. The surface of the chip may have fragile air bridges and should not be touched LIN with vacuum col et, tweezers, or fingers.
Mounting
The chip is back-metal ized and can be die mounted with AuSn eutectic preforms or with electrical y 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 fil et is observed around the perimeter of the chip once it is placed into position. Cure epoxy per the manufacturer’s schedule.
Wire Bonding
Ball or wedge bond with 0.025mm (1 mil) diameter pure gold wire. Thermosonic wirebonding with a nominal stage temperature of 150 °C and a ball bonding force of 40 to 50 grams or wedge bonding force of 18 to 22 grams is rec- ommended. Use the minimum level of ultrasonic energy to achieve reliable wirebonds. Wirebonds should be started on the chip and terminated on the package or substrate. All bonds should be as short as possible <0.31mm (12 mils). For price, delivery, and to place orders: Analog Devices, Inc., One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106 Phone: 781-329-4700 • Order online at www.analog.com Application Support: Phone: 1-800-ANALOG-D
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