Compared with polymer-based biochips, such as polydimethylsiloxane (PDMS), glass based chips have drawn much attention due to their high transparency, chemical stability, and good biocompatibility. This paper investigated the glass molding process (GMP) for fabricating microstructures of microfluidic chips. The glass material was D-ZK3. Firstly, a mold with protrusion microstructure was prepared and used to fabricate grooves to evaluate the GMP performance in terms of roughness and height. Next, the molds for fabricating three typical microfluidic chips, for example, diffusion mixer chip, flow focusing chip, and cell counting chip, were prepared and used to mold microfluidic chips. The analysis of mold wear was then conducted by the comparison of mold morphology, before and after the GMP, which indicated that the mold was suitable for GMP. Finally, in order to verify the performance of the molded chips by the GMP, a mixed microfluidic chip was chosen to conduct an actual liquid filling experiment. The study indicated that the fabricating microstructure of glass microfluidic chip could be finished in 12 min with good surface quality, thus, providing a promising method for achieving mass production of glass microfluidic chips in the future.

Through Silicon Via (TSV) technology is capable meeting effective, compact, high density, high integration, and high-performance requirements. In high-frequency applications, with the rapid development of 5G and millimeter-wave radar, the TSV interposer will become a competitive choice for radio frequency system-in-package (RF SIP) substrates. This paper presents a redundant TSV interconnect design for high resistivity Si interposers for millimeter-wave applications. To verify its feasibility, a set of test structures capable of working at millimeter waves are designed, which are composed of three pieces of CPW (coplanar waveguide) lines connected by single TSV, dual redundant TSV, and quad redundant TSV interconnects. First, HFSS software is used for modeling and simulation, then, a modified equivalent circuit model is established to analysis the effect of the redundant TSVs on the high-frequency transmission performance to solidify the HFSS based simulation. At the same time, a failure simulation was carried out and results prove that redundant TSV can still work normally at 44 GHz frequency when failure occurs. Using the developed TSV process, the sample is then fabricated and tested. Using L-2L de-embedding method to extract S-parameters of the TSV interconnection. The insertion loss of dual and quad redundant TSVs are 0.19 dB and 0.46 dB at 40 GHz, respectively.

This paper investigates the formation process of a typical microstructure in the glass microfluidic chip, i.e., cuboid microprotrusion, by the soda-lime glass molding process (GMP). The finite element models on the platform Abaqus/Standard were established for simulating the glass molding process. The glass viscoelasticity at pressing temperature was described by the General Maxwell model. The influence of the temperature, aspect ratio and side wall angle on the replication ratio was investigated, and the corresponding predicted molded profiles were demonstrated as well. The established simulation model was verified by experimental results eventually. It could provide a fundamental experience for optimizing glass molding parameters to fabricate microstructures on glass chips.

We report on the fabrication of highly uniform field emitter arrays (FEAs) with an integrated self-aligned extraction gate from bulk molybdenum. All critical dimensions of the emitter tip were determined by a single process step of Inductively Coupled Plasma (ICP) etching. In addition, the height difference between the emitter tip and the gate plane was controlled by the thickness of the SiO₂ dielectric layer. A 10 µm gate aperture molybdenum-FEAs (Mo-FEAs) at a typical 20 µm pitch with 6 µm height was achieved with 8.4 mA/cm² current density at gate voltages of 110 V and the turn-on field of 1.4 V/µm. These self-aligned Mo-FEAs could be expanded to active larger areas to increase the emission current.

Processing conditions are herein explored for the etching of bulk Mo by inductively coupled plasma towards nano tip arrays for field electron emission applications.