Fabrication of Glass Mixing Channels and Silicon Detection Cell with 45˚ Mirror Surfaces for the Indophenol Sensing Device

2005 ◽  
Vol 475-479 ◽  
pp. 1849-1852
Author(s):  
Kyu Shik Shin ◽  
Joon Shik Park ◽  
Kwang Bum Park ◽  
Hyo Derk Park ◽  
Jeong Rim Kim ◽  
...  

Design and fabrication of micro mixing cells and detection cells were investigated. Glass micro mixing cells with island structures among channels were fabricated using sand blaster methods. Depth and width of mixing channel were 200 ㎛ and 180 ㎛ and island size was 90 ㎛ by 90 ㎛. Two 45° mirrors surfaces faced on each other in one detection cell which were fabricated by silicon anisotropic etching using 20% TMAH (Tetramethylammonium hydroxide) solution with 20% or 30% IPA (iso propyl alcohol) at 80°C, respectively. Up side glass wafer for mixing cell and down side silicon wafer for detection cell were bonded using anodic bonding method at 350ı, -600 V and 300 N. Synthetic indophenol was injected at inlet and moved to the detection cell through the mixing channel. HeNe laser of 632.8 nm was focused on one side of a 45° mirror, and passed through indophenol solution until the other side of a 45° mirror. The light of 632.8 nm was absorbed in indophenol solution between two 45° mirrors at detection cell. By the Beer-Lambert’s law, indophenol concentration could be calculated from the measured result of the absorbance.

2011 ◽  
Vol 2011 (DPC) ◽  
pp. 002314-002335
Author(s):  
Akinori Shiraishi ◽  
Mitsutoshi Higashi ◽  
Kei Murayama ◽  
Yuichi Taguchi ◽  
Kenichi Mori

In recent years, downsizing of MEMS package and high accuracy MEMS device mounting have been strongly required from expanding applications that using MEMS not only for industrial and automobile but also for consumer typified mobile phone. In order to achieve that, it is appropriate to use Silicon package that can be mounted at wafer level packaging. Silicon package is made of monocrystal silicon wafer. The deep cavity is fabricated on monocrystal silicon wafer by Wet or Dry etching. And MEMS device can be mounted on the cavity. The electrical connecting between front side and back side of cavity portion is achieved by TSVs that located on the bottom of cavity. Hermetic seal can be achieved by using glass or silicon wafer bonding method. By using a driver device wafer (before dicing) as the cap for hermetic seal, smaller size and smaller number of parts module can be fabricated. In this report, methods and designs for hermetic seal with wafer level process were examined. Methods that applied were polyimide adhesive bonding, anodic bonding and Au-In solder bonding. Location of TSVs on the bottom of cavity and thickness of diaphragm with TSVs was also examined. Silicon package for piezo type gyro MEMS that designed by the result of evaluation was fabricated. This package used optimized Au-In solder bonding for hermetic seal and optimized location of TSVs for interconnection. That was designed over 50% thinner than conventional ceramic packages. Characteristics of hermetic seal were evaluated by Q factor of gyro MEMS that mounted inside of the silicon package. It is confirmed that performance of sealing are good enough for running of the MEMS.


2001 ◽  
Vol 681 ◽  
Author(s):  
Henry Allen ◽  
Kamrul Ramzan ◽  
Jim Knutti ◽  
Stan Withers

ABSTRACTA novel subminiature pressure sensor for blood pressure measurement has been fabricated. The device is only 250 microns wide and 70 microns thick. It is 1.1 mm in length. The sensor is housed in a guide-wire lead for use in measuring coronary artery blood pressure. The device has a 5 micron thick silicon diaphragm and senses pressure using a 1/2 bridge piezoresistive network. Glass is processed to provide depressions above the sensing area as well as above the connection area of the device. A full-thickness silicon wafer is processed using standard micromachining techniques. V-Groove notches are micro-machined on the top surface of the silicon to provide locators/guides for the lead-wires. Diaphragm windows are patterned on the back of the silicon wafer and the wafer is etched down to form the 5 micron diaphragm, using electro-chemical etch-stop techniques. The Glass and Silicon wafers are aggressively cleaned prior to bond. The glass and silicon wafers are then precisely aligned to better than 10 microns and bonded using anodic bonding techniques.The glass/silicon wafer sandwich then has the silicon thinned from 400 microns to 37 microns using both grinding and polishing. Then the full-thickness glass wafer is etched in HF to a thickness of 37 microns as well, for a composite 74-micron thick structure. The wafer is then diced to form the micro-mechanical structure.


Author(s):  
S. Theppakuttai ◽  
D. B. Shao ◽  
S. C. Chen

In this paper, we report a method to bond silicon and glass wafers directly using localized laser heating (pulsed Nd:YAG laser, 1064 nm, 12 ns). Laser energy was transmitted through the glass wafer and absorbed by the silicon wafer, resulting in a localized high temperature area. Pressure was applied upon the silicon and glass wafers to ensure immediate contact and good heat conduction between them. Scanning electron microscope (SEM) and chemical analysis were used to study bonding area and bonding mechanism. Numerical simulation was carried out in parallel using finite element method to predict the local temperature change of both the glass wafer and the silicon wafer during laser heating. The simulation was validated to some extent by the matching of melting time, which was obtained by using an additional probing laser (He-Ne, 633 nm, 20 mW) during the transient melting and re-solidification of the silicon. This bonding process is conducted locally while the entire wafer is maintained at room temperature, making it advantageous over traditional anodic bonding or fusion bonding.


Author(s):  
J. Wei ◽  
Z. P. Wang ◽  
L. Wang ◽  
G. Y. Li ◽  
Z. Q. Mo

In this paper, anodic bonding between silicon wafer and glass wafer (Pyrex 7740) has been successfully achieved at low temperature. The bonding strength is measured using a tensile testing machine. The interfaces are examined and analyzed by scanning acoustic microscopy (SAM), scanning electron microscopy (SEM) and secondary ion mass spectrometry (SIMS). Prior to bonding, the wafers are cleaned in RCA solutions, and the surfaces become hydrophilic. The effects of the bonding parameters, such as bonding temperature, voltage, bonding time and vacuum condition, on bonding quality are investigated using Taguchi method, and the feasibility of bonding silicon and glass wafers at low temperature is explored. The bonding temperature used ranges from 200 °C to 300 °C. The sensitivity of the bonding parameters is analyzed and it is found that the bonding temperature is the dominant factor for the bonding process. Therefore, the effects of bonding temperature are investigated in detail. High temperatures cause high ion mobility and bonding current density, resulting in the short transition period to the equilibrium state. Almost bubble-free interfaces have been obtained. The bonded area increases with increasing the bonding temperature. The unbonded area is less than 1.5% within the whole wafer for bonding temperature between 200 °C to 300 °C. The bonding strength is higher than 10 MPa, and increases with the bonding temperature. Fracture mainly occurs inside the glass wafer other than in the interface when the bonding temperature is higher than 225 °C. SIMS results show that the chemical bonds of Si-O form in the interface. Higher bonding temperature results in more oxygen migration to the interface and more Si-O bonds. The bonding mechanisms consist of hydrogen bonding and Si-O chemical reaction.


Author(s):  
Tianhong Cui ◽  
Kody Varahramyan ◽  
Yongjun Zhao ◽  
Jing Wang

This paper reports the simulation and fabrication of novel polymer-based tunneling sensors by hot embossing technique, one of the advanced polymer microfabrication technologies. ANSYS is the software tools used to simulate the mechanical microstructures of the polymer tunneling sensors. Following the optimum design of the sensors, the mold inserts of hot embossing are fabricated by anodic bonding of glass disk 5 mm think and silicon wafer, with high-aspect-ratio microstructures by ICP etching. Main structures of polymer-based tunneling sensors are hot embossed on PMMA, followed by plastic bonding to form lateral tunneling sensor platform.


Micromachines ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 818
Author(s):  
Milena Rašljić Rafajilović ◽  
Katarina Radulović ◽  
Milče M. Smiljanić ◽  
Žarko Lazić ◽  
Zoran Jakšić ◽  
...  

We present the design, simulation, fabrication and characterization of monolithically integrated high resistivity p-type boron-diffused silicon two-zone heaters in a model high temperature microreactor intended for nanoparticle fabrication. We used a finite element method for simulations of the heaters’ operation and performance. Our experimental model reactor structure consisted of a silicon wafer anodically bonded to a Pyrex glass wafer with an isotropically etched serpentine microchannels network. We fabricated two separate spiral heaters with different temperatures, mutually thermally isolated by barrier apertures etched throughout the silicon wafer. The heaters were characterized by electric measurements and by infrared thermal vision. The obtained results show that our proposed procedure for the heater fabrication is robust, stable and controllable, with a decreased sensitivity to random variations of fabrication process parameters. Compared to metallic or polysilicon heaters typically integrated into microreactors, our approach offers improved control over heater characteristics through adjustment of the Boron doping level and profile. Our microreactor is intended to produce titanium dioxide nanoparticles, but it could be also used to fabricate nanoparticles in different materials as well, with various parameters and geometries. Our method can be generally applied to other high-temperature microsystems.


Author(s):  
Jung-Yeul Jung ◽  
Ho-Young Kwak

A bubble-powered micropump was fabricated and tested in this study. The micropump consists of a pair of nozzle-diffuser flow controller and a pumping chamber. The two-parallel micro line heaters were fabricated to be embedded in the silicon dioxide layer above a silicon wafer which serves as a base plate for the micropump. The pumping chamber, the pair of nozzle-diffuser unit and microchannels including the liquid inlet and outlet port were fabricated by etching through another silicon wafer. A glass wafer having two holes of inlet and outlet ports of liquid serve as upper plate of the pump. The sequential photographs of bubble nucleation, growth and collapse were visualized by CCD camera. Clearly liquid flow through the nozzle during the period of bubble growth and slight back flow of liquid at the initial period collapsing can be seen. The mass flow rate was found to be dependent on the duty ratio and the operation frequency. The mass flow rate decreases as the duty ratio increases in the micropump with either circular or square pumping chamber.


2010 ◽  
Vol 16 (10) ◽  
pp. 1765-1769 ◽  
Author(s):  
Da-Yong Qiao ◽  
Song-Jie Wang ◽  
Wei-Zheng Yuan

Author(s):  
Qiong Shu ◽  
Juan Su ◽  
Gang Zhao ◽  
Ying Wang ◽  
Jing Chen

In this paper, Ti-Glass anodic bonding is investigated on both chip and wafer level. In concern of coefficients of thermal expansion (CTE) match, three different types of ion-containing glasses are evaluated: Pyrex 7740, D-263T and soda lime glass. By applying a potential between the two chips and heating them beyond 350°C, soda lime glass samples are successfully bonded with titanium. The influence of the bonding temperature on the bonding strength is revealed. For the first time, wafer level Ti-Glass bond is carried out, a 157-μm-thick titanium wafer is successfully bonded to a 1000-μm-thick soda glass wafer at 450°C and applying a voltage of 800V and a force of 1000N for 30min, over 60% of the surface are joined. The results are helpful to define potential applications in certain field of microsystems.


2012 ◽  
Vol 569 ◽  
pp. 153-158
Author(s):  
Ye Yuan ◽  
Hong Juan Cui ◽  
Xing Hua Wang ◽  
Ding Bang Xiao ◽  
Xue Zhong Wu

Based on the triple-stack structure of "sandwich" of three-axis micro-accelerometer, a anodic bonding technology about three-layer of glass-silicon-glass is brought out. As the advantage of the triple-stack structure is introduced, the process of traditional anodic bonding is expounded. Since the bonding in the first time has led the layers of glass and silicon felt together, the strength of the first bonding will be destroyed if the electrode loads on the bonding glass-silicon surface directly in the second time. For this problem, the methed using dielectric material to pass bonding voltage is proposed. The results of the experiment show that the proposed new three-stack bonding method is simple and feasible.


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