link to page 10 link to page 10 link to page 10 link to page 10 link to page 10 HMC903Data SheetMOUNTING AND BONDING TECHNIQUES FOR MILLIMETERWAVE GaAs MMICS The HMC903 is attached directly to the ground plane Storage eutectically or with conductive epoxy (see the General Handling All bare die are placed in either waffle or gel-based ESD protective section, the Mounting section, and the Wire Bonding section). containers and then sealed in an ESD protective bag for shipment. The 50 Ω microstrip transmission lines on 0.127 mm (5 mil) After opening the sealed ESD protective bag, store all die in a thick alumina thin film substrates are recommended for dry nitrogen environment. bringing RF to and from the HMC903 (see Figure 20). When Cleanliness using 0.254 mm (10 mil) thick alumina thin film substrates, the die is raised 0.150 mm (6 mil) so the surface of the die is coplanar Handle the chips in a clean environment. Do not attempt to with the surface of the substrate. One way to accomplish this is clean the chip using liquid cleaning systems. to attach the 0.102 mm (4 mil) thick die to a 0.150 mm (6 mil) Static Sensitivity thick molybdenum heat spreader (moly tab), which then attaches Fol ow ESD precautions to protect against ESD strikes. to the ground plane (see Figure 21). Transients Suppress instrument and bias supply transients while bias is 0.102mm (0.004") THICK GaAs MMIC applied. Use the shielded signal and bias cables to minimize inductive pickup. WIRE BOND0.076mmGeneral Handling(0.003") Handle the chip along the edges with a vacuum col et or with a sharp pair of bent tweezers. The surface of the HMC903 has RF GROUND PLANE fragile air bridges and must not be touched with the vacuum collet, tweezers, or fingers. 0.127mm (0.005") THICK ALUMINA 020 THIN FILM SUBSTRATEMounting 14481- The HMC903 is back metallized and can be die mounted with Figure 20. Routing RF Signal gold tin (AuSn) eutectic preforms or with electrical y conductive epoxy. The mounting surface must be clean and flat. 0.102mm (0.004") THICK GaAs MMICEutectic Die AttachWIRE BOND0.076mm(0.003") An 80% gold/20% tin preform is recommended with a work surface temperature of 255°C and a tool temperature of 265°C. When hot 90% nitrogen/10% hydrogen gas is applied, the tool tip temperature is 290°C. Do not expose the chip to a temperature RF GROUND PLANE greater than 320°C for more than 20 sec. No more than 3 sec of scrubbing is required for attachment. 0.150mm0.254mm (0.010") THICK ALUMINA(0.006") THICK 021 THIN FILM SUBSTRATEMOLY TABEpoxy Die Attach 14481- Apply a minimum amount of epoxy to the mounting surface so Figure 21. Routing RF Signal with Moly Tab that a thin epoxy fil et is observed around the perimeter of the Microstrip substrates are placed as close to the die as possible to HMC903 after it is placed into position. Cure epoxy per the minimize bond wire length. Typical die to substrate spacing is schedule of the manufacturer. 0.076 mm to 0.152 mm (3 mil to 6 mil). Wire BondingHANDLING PRECAUTIONS RF bonds made with two 1 mil wires are recommended. These Fol ow the precautions detailed in the following sections to bonds are thermosonically bonded with a force of 40 g to 60 g. avoid permanent damage to the device. DC bonds of 0.001 in (0.025 mm) diameter, thermosonical y bonded, are recommended. Create ball bonds with a force of 40 g to 50 g and wedge bonds at 18 g to 22 g. Create bonds with a nominal stage temperature of 150°C. A minimum amount of ultrasonic energy is applied to achieve reliable bonds. All bonds are as short as possible, less than 12 mil (0.31 mm). Rev. C | Page 10 of 13 Document Outline FEATURES APPLICATIONS GENERAL DESCRIPTION FUNCTIONAL BLOCK DIAGRAM TABLE OF CONTENTS REVISION HISTORY SPECIFICATIONS ELECTRICAL SPECIFICATIONS ABSOLUTE MAXIMUM RATINGS ESD CAUTION PIN CONFIGURATION AND FUNCTION DESCRIPTIONS INTERFACE SCHEMATICS TYPICAL PERFORMANCE CHARACTERISTICS THEORY OF OPERATION APPLICATIONS INFORMATION MOUNTING AND BONDING TECHNIQUES FOR MILLIMETERWAVE GaAs MMICS HANDLING PRECAUTIONS Storage Cleanliness Static Sensitivity Transients General Handling Mounting Eutectic Die Attach Epoxy Die Attach Wire Bonding TYPICAL APPLICATION CIRCUITS ASSEMBLY DIAGRAMS OUTLINE DIMENSIONS ORDERING GUIDE