Development of New Evaluation Method for Adhesive Strength between Microsized Photoresist and Si Substrate of MEMS Devices

2007 ◽  
Vol 345-346 ◽  
pp. 1185-1188 ◽  
Author(s):  
Chiemi Ishiyama ◽  
Masato Sone ◽  
Yakichi Higo
Keyword(s):  
Adhesive Strength ◽  
Evaluation Method ◽  
Testing Machine ◽  
Micro Electro Mechanical System ◽  
Shear Loading ◽  
Cylindrical Shape ◽  
Mems Devices ◽  
Si Substrate ◽  
Loading Mode ◽  
Adhesive Shear Strength

An evaluation method for adhesive bending and shear strengths between microsized components and silicon substrate were developed to quantitively determine micro-sized adhesive strength for micro-electro mechanical system (MEMS) devices. Cylindrical shape is employed as a micro-sized adhesive specimen to simply analyze adhesive stresses of both shear and bending. Micro-sized adhesive tests between micro-sized SU-8 cylindrical specimen and Si substrate were performed using a mechamical testing machine for micro-sized material that has developed by our group. Delamination of all the specimens occurred within the SU-8 near by the substrate in a brittle manner under both bending and shear loading conditions. The adhesive bending stress is 57 % lower than the bend strength of the SU-8 material. The adhesive shear strength under bend loading is 15 % lower than the adhesive strength under shear loading and the delamination surface is different in each loading mode. All the results suggest that some defects at the interface must induce the stress concentration, which may make the apparent strength of SU-8 decrease.

Effects of Aspect Ratio of Micro-sized Photoresist Patterns on Bond Strength between a Si Substrate with AFM Fracture Observation

2008 ◽  
Vol 1139 ◽  
Author(s):  
Chiemi Ishiyama ◽  
Akinobu Shibata ◽  
Masato Sone ◽  
Yakichi Higo
Keyword(s):  
Aspect Ratio ◽  
Bond Strength ◽  
Testing Machine ◽  
Three Dimensional ◽  
Maximum Load ◽  
Initiation Site ◽  
Cylindrical Shape ◽  
Si Substrate ◽  
Cylinder Length ◽  
Loading Mode

AbstractBond strength between three dimensional micro-sized cylindrical patterns and Si substrate has been evaluated to clarify the effects of the cylinder length vs. diameter ratio, i.e. the aspect ratio, on the bond strength. Cylindrical shape was employed for avoiding ambiguity of loading point under bend conditions. Multiple cylindrical specimens of an epoxy type photoresist, SU-8 with various lengths were fabricated on a silicon substrate under the same photolithographic condition. Bond strength between micro-sized SU-8 and Si substrate under bend loading mode was measured by a mechanical testing machine for micro-sized materials. The maximum bend moment is 9.6 × 10−6 Nm in average and lineally increases with increasing the aspect ratio. On the other hand, the maximum load, i.e. maximum shear load is 106 mN in average and almost constant with increasing aspect ratio. This result suggests that the shear stress near the interface may cause the initiation of delamination. This phenomenon is discussed with three dimensional fracture observation and quantitative analysis of the line profile around the initiation site by AFM.

Development of Evaluation Method for Delamination Strength Between Micro-Sized Materials in MEMS Devices

2006 ◽  
Vol 977 ◽  
Author(s):  
Chiemi Ishiyama ◽  
Junichi Hata ◽  
Satoru Koyama ◽  
Masato Sone ◽  
Yakichi Higo
Keyword(s):  
Shear Stress ◽  
Mechanical Testing ◽  
Evaluation Method ◽  
Maximum Shear Stress ◽  
Testing Machine ◽  
Fracture Load ◽  
Displacement Curve ◽  
Mems Devices ◽  
Si Substrate ◽  
Load Displacement

AbstractEvaluation method for delamination strength of micro-sized materials has been developed using by FEM and measurement of load-displacement curve of micro-sized specimen. This evaluation method is applied to micro-sized cylindrical SU-8 specimens on Si substrate. The maximum shear stress between SU-8 and Si was analyzed with FEM. Fracture load required to delaminate the two materials was examined using a mechanical testing machine for micro-sized materials, which have been developed in our group. The delamination strength was determined from the maximum shear stress and the fracture load.

M2-1 Evaluation of Adhesive Strength between Micro-Sized Components and Si Substrate of MEMS Devices (M2 MaterialCharacterization)

2009 ◽  
Vol 2009.1 (0) ◽  
pp. 35-36
Author(s):  
Kosuke TANAKA ◽  
Masaaki OTSU ◽  
Kazuki TAKASHIMA ◽  
Chiemi ISHIYAMA ◽  
Yakichi HIGO
Keyword(s):  
Adhesive Strength ◽  
Mems Devices ◽  
Si Substrate

A Stress Singularity Parameter Approach for Evaluating the Interfacial Reliability of Plastic Encapsulated LSI Devices

1989 ◽  
Vol 111 (4) ◽  
pp. 243-248 ◽  
Author(s):  
T. Hattori ◽  
S. Sakata ◽  
G. Murakami
Keyword(s):  
Adhesive Strength ◽  
Evaluation Method ◽  
Stress Singularity ◽  
The Finite Element Method ◽  
Displacement Fields ◽  
Stress And Displacement Fields ◽  
Ni Alloy ◽  
Base Resin ◽  
Interfacial Reliability ◽  
Parameter Approach

Since the stress and displacement fields near a bonding edge show singularity behaviors, the adhesive strength evaluation method, using maximum stresses calculated by a numerical stress analysis such as the finite element method, is generally not valid. In this paper, a new method, which uses two stress singularity parameters, is presented for evaluating adhesive strength. This method is applied to several kinds of molded models, composed of epoxy base resin and Fe-Ni alloy sheets, and plastic encapsulated LSI models. Predictions about the initiation and extension of delamination are compared with the results of observations made by scanning acoustic tomography on these models.

Mechanical response of marble epistyles under shear: numerical analysis using an experimentally validated model

2018 ◽  
Vol 27 (3-4) ◽  
Author(s):  
Ermioni D. Pasiou ◽  
Stavros K. Kourkoulis
Keyword(s):  
Numerical Model ◽  
Stress Field ◽  
Mechanical Response ◽  
Specific Problem ◽  
Shear Loading ◽  
Filling Material ◽  
Experimental Protocol ◽  
Loading Mode ◽  
Traditional Design ◽  
Simple Contact

AbstractThe mechanical response of the restored “connections” of the epistyles of the Parthenon Temple on the Acropolis of Athens is studied assuming that the interconnected epistyles are under shear loading mode. The study is implemented by taking advantage of a numerical model, properly validated on the basis of the data of a recent relative experimental protocol. The main difficulty while studying the specific problem is the co-existence of three materials of completely different mechanical behaviors, i.e. the brittle marble of the epistyles, the ductile titanium of the connector and the cement-based material filling the grooves of the marble in which the connector is placed. The interfaces of this three-material-complex are simulated as simple contact with friction, the coefficient of which is, also, experimentally determined. Taking advantage of the data provided by the numerical model the stress field developed in the connector and the surrounding marble volume is described. Moreover, the forces imposed by the connector on the surface of the groove are quantitatively determined. Furthermore, the model permits a quantitative comparison between the mechanical response of the interconnected epistyles in the presence or in the absence of the “relieving space”. It is definitely concluded that the alternative design of the “connections”, according to which a small portion of the connector’s web is left uncovered by the filling material (relieving space), offers serious advantages against the traditional design, in the direction of reducing the intensity of the stress field developed in the marble volume surrounding the connector, thus, contributing to the protection of the authentic building material of the monument in the case of overloading of the epistyles.

scholarly journals Effect of Nd:YAG Laser with/without Graphite Coating on Bonding of Lithium Disilicate Glass-Ceramic to Human Dentin

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Amjad Abu Hasna ◽  
Stephanie Semmelmann ◽  
Fernanda Alves Feitosa ◽  
Danilo De Souza Andrade ◽  
Franklin R Tay ◽  
...  
Keyword(s):  
Bond Strength ◽  
Glass Ceramic ◽  
Nd:Yag Laser ◽  
Testing Machine ◽  
Glass Ceramics ◽  
Lithium Disilicate ◽  
Resin Cement ◽  
Cylindrical Shape ◽  
Universal Testing ◽  
Human Dentin

This study evaluated the effect of different surface treatments on the tensile bond strength between lithium disilicate glass-ceramics, resin cement, and dentin. Fifty truncated cone-shape glass-ceramics were divided into five groups (n = 10): G1, control: 10% hydrofluoric acid (HF); G2, Nd:YAG laser + silane; G3, Sil + Nd:YAG laser; G4, graphite + Nd:YAG laser + Sil; and G5, graphite + Sil + Nd:YAG laser. Fifty human third-molars were cut to cylindrical shape and polished to standardize the bonding surfaces. The glass-ceramic specimens were bonded to dentin with a dual-cured resin cement and stored in distilled water for 24 h at 37ºC. Tensile testing was performed on a universal testing machine (10 Kgf load cell at 1 mm/min) until failure. The bond strength values (mean ± SD) in MPa were G1 (9.4 ± 2.3), G2 (9.7 ± 2.0), G3 (6.7 ± 1.9), G4 (4.6 ± 1.1), and G5 (1.2 ± 0.3). Nd:YAG laser and HF improve the bond strength between lithium disilicate glass-ceramics, resin cement, and dentin. The application of a graphite layer prior to Nd:YAG laser irradiation negatively affects this bonding and presented inferior results.

Infrared Radiative Properties of Heavily Doped Silicon at Room Temperature

2007 ◽  
Author(s):  
S. Basu ◽  
B. J. Lee ◽  
Z. M. Zhang
Keyword(s):  
Carrier Mobility ◽  
Room Temperature ◽  
Radiative Properties ◽  
Multilayer Thin Films ◽  
Mems Devices ◽  
Si Substrate ◽  
Model Predictions ◽  
Doped Silicon ◽  
Infrared Spectrometer ◽  
Heavily Doped

This paper describes an experimental investigation on the infrared radiative properties of heavily-doped silicon (Si) at room temperature. Lightly-doped Si wafers were ion implanted with boron and phosphorus atoms to doping concentrations of 1×1020 and 1×1021 cm−3. Rapid thermal annealing was performed to activate the implanted dopants. A Fourier-transform infrared spectrometer was employed to measure the normal transmittance as well as reflectance of the samples in the spectral region from 2 to 20 μm. Accurate carrier mobility and ionization models were identified after carefully reviewing the available literature, and then incorporated into Drude model to predict the dielectric function of doped Si. The radiative properties of doped Si samples were calculated by treating the doped region as multilayer thin films of different doping concentrations on a thick Si substrate. The measured spectral transmittance and reflectance agree well with the model predictions. The results obtained from this study will facilitate the future applications of heavily-doped Si in semiconductor as well as MEMS devices.

Convenient Adhesive Strength Evaluation Method in Terms of the Intensity of Singular Stress Field

2018 ◽  
Vol 16 (01) ◽  
pp. 1850085 ◽  
Author(s):  
Nao-Aki Noda ◽  
Rong Li ◽  
Tatsujiro Miyazaki ◽  
Rei Takaki ◽  
Yoshikazu Sano
Keyword(s):  
Stress Field ◽  
Conventional Method ◽  
Adhesive Strength ◽  
Evaluation Method ◽  
Singular Stress ◽  
Strength Evaluation ◽  
Present Solution ◽  
Singular Stress Field

A convenient evaluation method is proposed for the debonding adhesive strength in terms of the intensity of singular stress field (ISSF) appearing at the end of interface. The same FEM mesh pattern is applied to unknown problems and reference problems. It is found that the ISSF is obtained accurately by focussing on the FEM stress at the adhesive corner. Then, the debonding condition can be expressed as a constant value of critical ISSF. The usefulness of the present solution is verified by comparing with the results of the conventional method.

Experimental Study on Fundamental Phenomena of Boiling by Using Heat Transfer Surface With Well-Defined Cavities Created by MEMS: The Effect of Spacing Between Cavities

2006 ◽  
Author(s):  
Takato Sato ◽  
Yasuo Koizumi ◽  
Hiroyasu Ohtake
Keyword(s):  
Heat Transfer ◽  
Nucleate Boiling ◽  
Micro Electro Mechanical System ◽  
Heat Transfer Surface ◽  
Cylindrical Shape ◽  
Main Role ◽  
Nucleate Boiling Heat Transfer ◽  
Mems Technology ◽  
Strong Convection ◽  
Artificial Cavity

Pool nucleate boiling heat transfer experiments were performed for water by using the well-controlled and -defined heat transfer surfaces. Artificial cavity(ies) was (were) created on the mirror-finished silicon plate of 0.525 mm thickness by utilizing the Micro-Electro Mechanical System (MEMS) technology. Each cavity had cylindrical shape. The diameter and the depth of the cavity were 10μm and 40μm, respectively. Experiments were performed in a range of a heat flux ∼6.0 × 104 W/m2 for distilled water. When the cavity interval was close, the horizontal and declining coalescence of bubble on the cavities were dominant. This vigorous bubble coalescence created strong convection. The heat carried by this convection took a main part in the heat transfer when cavities were close. As the cavity interval became wide, the horizontal and declining coalescence did not take place anymore. The coalescence was limited only to the vertical lift or no coalescence. In this situation, bubbles grew large on the cavities and absorbed latent heat sufficiently. Bubbles themselves took the main role of carrying heat away from the heat transfer surface when cavities were further apart.

Sign in / Sign up

Export Citation Format

Share Document