The assembly lab is a dual-bay, 1500 square foot, Class 100 clean room for microelectronics prototype assembly, inspection, rework, and failure analysis. The Class 100 assembly laboratory is sufficiently clean to support critical tasks such as thin film spin coating and mask alignment, and exposure for photolithography.
North
bay of SPPDG Class 100 clean room. Left hand side: Two manual die bonders, manual wire bonder, hot gas rework station, ball grid array assembly station, ball grid array rework station, production-rated Palomar Model 3500 automatic pick-and-place component assembly machine; Right hand side: wafer dicing saw, wafer tape expander, wafer scriber, general inspection microscope, wide-field measurement microscope, high magnification measurement microscope, lead-forming station.
South bay of SPPDG Class 100 clean room. Left hand side: Ultra-high vacuum package sealer, Thermodyne 30400 furnace , MCS LF-5 plasma oven, Ecomet 3 grinder polisher, Isomet 2000 precision saw Logitech LP50 wafer thinner. Right hand side: two Palomar wedge bonders, Royce wire pull/shear tester, Palomar ball bonder, Karl Suss FC150 flip chip bonder, ESD storage cabinets.
Assembly Capabilities
The SPPDG assembly laboratory provides a collage of capabilities in first and second level packaging.
First Level Packaging
The assembly laboratory provides prototype high-end first level packaging capability. Specifically, an integrated circuit (IC) wafer from 3" to 8" in diameter can be thinned from its nominal 50 mil thickness down to as little as 2 mils (as required by the systems application), and then scribed or sawed into individual IC die. These die can be attached "face up" into single chip packages or multichip modules (MCMs) using eutectic solder reflow or epoxy die attachment methods (first Figure below), or attached "face down" using flip chip die attachment methods (second Figure below). For "face up" mounting, the power, ground and signal pins on the die can be connected to the IC package or MCM utilizing automatic wire bonding (both wedge and ball types). For "face down" mounting, the bare die can be "bumped" with gold balls in our facility to facilitate attachment. The flip chip attachment of bare die onto an interposer ball grip array (BGA) board or multichip module (MCM) substrate can be accomplished through either thermo-compression, thermo-sonic bonding or eutectic solder with better than 5 micron overlay accuracy in both X- and Y- dimensions.
Our laboratory can also provide very precise chip placement over a 6” x 6” area with better than 10 micron accuracy. To complement this packaging capability, the laboratory can also provide hermetic packaging of integrated circuit components.
IC and capacitor die attach in ceramic chip carrier.
Photomicrograph of flip chip die on liquid crystal polymer (LCP) printed circuit board material for 80 Gbps circuit demonstration.
Second Level Packaging
For second level packaging capability, the laboratory is equipped to handle various prototype printed circuit board assemblies. Surface mount attachment of packaged discretes, ICs, connectors, BGA devices, etc., is performed utilizing either an automated or manual pick and place machine with better than 12 micron X and Y overlay accuracy. Leaded and lead-free solders along with epoxies can be dispensed automatically or manually on those same machines or with a manual screen printer. Reflow is executed with a 5-zone combination IR and convection reflow belt oven. A substrate degreaser is also available.
The laboratory also has X-ray inspection capability for flip chip and BGA mechanical inspection. To address the processing of "reduction of hazardous substances" (ROHS) lead-free components, the laboratory also has X-ray fluorescence (XRF) capability for surface finish and BGA solder ball material characterization to determine proper solder reflow processes.
Sampling of Assembly Tool Set
Finetech Pico flip chip bonder (See first Figure below)
Karl Suss FC-150 flip chip bonder (See second Figure below)
Palomar Model 3500 automatic pick-and-place component assembly machine
X-Tek Hawk X-ray inspection system
Oxford XGT-1000WR XRF
Palomar 2460-V ball bonder & 2470-V wedge bonder
LPKF printed circuit board prototype unit (See third Figure below)
Finetech pico bonder A4V flip chip attach system.
Karl Suss FC-150 flip-chip precision die alignment, placement, and bonding, with 1-3 micron overlay accuracy and up to 50 kg of force.
EXAMPLE OF TOOL CAPABILITY LPKF Protomat S62 advanced circuit board router.
Rework and Failure Analysis
Rework and failure analysis can be performed for all assembly processes (for example see Figure immediately below), in some cases on bare substrates and bare die by utilizing the following capabilities:
YAG laser system
Hot gas rework station
Wire bond pull, IC die shear, and ball shear tester
Microsectioning equipment
Inspection microscopes (3.2X to 1000X magnification) with oblique viewing and X Y Z micro measurement capability
Hitachi Model S-4700 Scanning Electron Microscope with energy dispersive analysis capability (resides immediately adjacent to the Class 100 Assembly Facility, see second Figure below)
A photography room located immediately adjacent to the clean room facilities
A flip chip C4 BGA package cross section viewed with a scanning electron microscope at 1000x magnification.
Hitachi S-4700 field emission scanning electron microscope (SEM) used to photograph surfaces of wafers and die and cross sections of die, coupons, and boards.
Other Capabilities
A chemical hood exists for solvent cleaning and thin film etching
Ultrasonic cleaning capability
Access to machine shop with complete Computer Numeric Control (CNC) capability on the Mayo Foundation-Rochester campus
