Michelle Chew

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Stacking of wafers with low chip-yield and non uniform chips size is developed for MEMS and 3D packaging applications. Stacking of MEMS and ASIC wafers one over other is difficult due to difference in chip yield and chip size. A cap wafer which is used for sealing the MEMS wafer in the wafer level package (WLP) is used for stacking the known good dice from(More)
A bio-microfluidic package has been developed with integrated reservoir and valves for DNA (deoxyribonucleic acid) lab on a chip (LOC) application. A polymer material, PDMS (polydimethylsiloxane) is used for encapsulating the DNA chip. Channels, reservoirs and valves are formed on the PDMS material by casting method. A double sided adhesive tape is used to(More)
A disposable self-contained microfluidic package has been developed and tested for on-chip DNA extraction from human blood for practical lab-on-a-chip platform. The microfluidic package has been customized to allow easy interface between the microscale sample injection to the Si-based microscale sample preparation chip. For precise sample dispensing and to(More)
In this paper, characterization of 3 types of underfill for high performance applications has been presented. Characterizations of underfill materials such as adhesion testing, contact angle measurement on different surfaces, filler size distribution were conducted to understand the underfill materials. The adhesion test results revealed that failure is(More)
A bio-microfluidic package has been developed with integrated reservoir and valves for DNA (deoxyribonucleic acid) lab on a chip (LOC) application. A polymer material, PDMS (polydimethylsiloxane) is used for encapsulating the DNA chip. Channels, reservoirs and valves are formed on the PDMS material by casting method. A mold fabricated in acrylic material is(More)
Wire bonding technology has been widely used in the semiconductor industry for interconnection between device and substrate. Gold wire has been used in industry for many years; however with the increase in the price of gold in the past few years, copper wire has become an alternative. Copper wires have better electrical and thermal performance than gold(More)
A dry film photoresist was selected as the sacrificial material for a metal lift off process. However, a weak and inconsistent adhesion of the evaporated under bump metallurgy (UBM) and solder on the passivation surface was observed during the dry film stripping process. This problem may be due to the poor negative profile (88 to 89 degrees) of the(More)
In this paper, evaluation of underfill materials for 3D SiP packages where micro bump interconnections and solder bumps has been presented. Characterization of underfill materials was carried out in terms of adhesion testing on various chip passivation surfaces and process optimization for void free filling. Capillary underfill materials have been evaluated(More)
A bio-microfluidic cartridge has been developed with integrated reservoir and valves for Lab on a chip (LOC) applications, e.g. extracting DNA (Deoxyribonucleic Acid) from human blood. A combination of different materials such as thermoplastic and elastomer are used to fabricate the microfluidic cartridge. A conical shape reservoir with thin membrane(More)
A capillary force driven passive valve is designed and studied with different valve dimensions to understand the threshold pressure of the valve. A capillary force driven valve has been formed by creating a smaller cross-section compared to the normal fluidic channel. CFD-ACE+, an advanced CFD & multiphysics software is used to conduct simulation to(More)