Low Temperature Anodic Bonding for MEMS Applications

2002 ◽  
Author(s):  
J. Wei ◽  
Z. P. Wang ◽  
L. Wang ◽  
G. Y. Li ◽  
Z. Q. Mo
Keyword(s):  
Low Temperature ◽  
Bonding Strength ◽  
Transition Period ◽  
Bonding Temperature ◽  
Testing Machine ◽  
Acoustic Microscopy ◽  
Anodic Bonding ◽  
Dominant Factor ◽  
Glass Wafer ◽  
Bonding Parameters

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.

A process analysis for microchannel deformation and bonding strength by in-mold bonding of microfluidic chips

2015 ◽  
Vol 35 (3) ◽  
pp. 267-275 ◽  
Author(s):  
Chunpeng Chu ◽  
Bingyan Jiang ◽  
Laiyu Zhu ◽  
Fengze Jiang
Keyword(s):  
Bonding Strength ◽  
Process Analysis ◽  
Bonding Temperature ◽  
Bonding Time ◽  
Production Cycle ◽  
Microfluidic Chips ◽  
Bonding Pressure ◽  
Bonding Parameters ◽  
Bonding Technology ◽  
Assembly Technology

Abstract A novel combination of thermal bonding and in-mold assembly technology was created to produce microfluidic chips out of polymethylmethacrylate (PMMA), which is named “in-mold bonding technology”. In-mold bonding experiments of microfluidic chips were carried out to investigate the influences of bonding process parameters on the deformation and bonding strength of microchannels. The results show that bonding temperature has the greatest impact on the deformation of microchannels, while bonding pressure and bonding time have more influence on deformation in height than in top width. Considering the bonding strength, the bonding temperature and the bonding pressure have more impact than the bonding time. The time is crucial for the sealing of the chips. By setting the bonding parameters reasonably, the microchannel deformation is <10%, while the bonding strength of the chips is 350 kPa. The production cycle of the chip is reduced to <5 min.

Evaluation and Characterization of Titanium to Glass Anodic Bonding

2008 ◽  
Author(s):  
Qiong Shu ◽  
Juan Su ◽  
Gang Zhao ◽  
Ying Wang ◽  
Jing Chen
Keyword(s):  
Bonding Temperature ◽  
Soda Lime ◽  
Anodic Bonding ◽  
Soda Lime Glass ◽  
Glass Wafer ◽  
Wafer Level ◽  
Different Types ◽  
Potential Applications ◽  
First Time

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.

High-Frequency and Low-Temperature Thermosonic Bonding of Lead-Free Microsolder Ball on Silver Pad Without Flux

2014 ◽  
Vol 136 (3) ◽  
Author(s):  
Fuliang Wang ◽  
Junhui Li ◽  
Lei Han
Keyword(s):  
Low Temperature ◽  
High Frequency ◽  
Bonding Strength ◽  
Bonding Temperature ◽  
Lead Free ◽  
High Bonding Strength ◽  
Solder Balls ◽  
Laser Soldering ◽  
Free Solder ◽  
Bonding Method

Lead-free solder balls are environment friendly; however, they require a high bonding temperature, which causes problems in the microelectronics package industry. To reduce the bonding temperature, a 60 kHz high-frequency thermosonic bonding method is proposed and realized using a lab bonder. Experimental results showed that this method could be used to bond a 300 μm-diameter Sn–Ag–0.5Cu microsolder ball onto a silver pad without flux at a low temperature of 160 °C in 3 s. A ball shear test showed that the high frequency led to a high bonding strength of 58.8 MPa, and a dimpled structure was observed at the bonding interface by SEM. Compare with the reflow method or laser soldering method, the proposed method requires a low bonding temperature and leads to a high bonding strength.

Low temperature Si-Si, SiO2-SiO2 covalent bonding structures with thin siloxane layer

2013 ◽  
Vol 2013 (1) ◽  
pp. 000424-000428
Author(s):  
Jeongyub Lee ◽  
Kunmo Chu ◽  
Yongyoung Park ◽  
Wooyoung Yang ◽  
Wenxu Xianyu ◽  
...  
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Layer Thickness ◽  
Bonding Strength ◽  
Oxygen Plasma ◽  
Coefficient Of Thermal Expansion ◽  
Bonding Temperature ◽  
Bonding Process ◽  
Oxygen Plasma Treatment ◽  
Adhesion Properties

We present new Si to Si, SiO2 to SiO2 bonding technologies for low temperature applications (&lt;200°C). Direct bonding process between Si (or SiO2) substrates makes high bonding strength without contamination problems. However, high temperature over 1000°C is needed for the reliable Si to Si and SiO2 to SiO2 direct bonding processes. To reduce the bonding temperature, thin siloxane layer and low-powered oxygen plasma treatment was used in this study. We used dimethyl siloxane layer having siloxane chains (-Si-O-)n and methyl ends. Siloxane layer is able to be bonded strongly with Si-based substrates at low temperature (&lt;200°C) when oxygen plasma is treated on it. Polymerized siloxane layer such as PDMS has much higher coefficient of thermal expansion (CTE) of 300ppm/K than Si of 2.6ppm/K. When the bonded structure is cooled or heated, the interfaces is possibly distorted and cracked by the high residual stress between siloxane layer and Si substrate. To solve these problems, we developed new fabrications of reducing the siloxane layer thickness to 3∼4nm, that is the monomer layer levels. Extremely thin thickness of siloxane layer prevented the problems of the CTE differences. The Si to Si bonding structure with siloxane layer showed strong adhesion properties in this study. The bonded body kept reliable bonding force when it was heated to high temperature (∼900°C). The feasible wafer-level bonding process was demonstrated. We investigated the siloxane layer thickness by TEM images. The bonding strength was confirmed by dicing test by 1mm and measured over 20MPa. We also expended this new development to SiO2 to SiO2 bonding structures. Low temperature bonding between non-Si substrates such as GaN was possible with thin siloxane layer when amorphous Si thin film was deposited on these substrates.

A Low Temperature, Non-Aggressive Wafer Level Hermetic Package With UV Cured SU8 Bond

2007 ◽  
Author(s):  
Yexian Wu ◽  
Guanrong Tang ◽  
Jing Chen
Keyword(s):  
Low Temperature ◽  
Bonding Temperature ◽  
Adhesive Layer ◽  
Glass Wafer ◽  
Wafer Level ◽  
Etching Technique ◽  
Micro Electro Mechanical Systems ◽  
Level 3 ◽  
A New Technique ◽  
Hermetic Package

In this paper, we present a new technique that could realize wafer level 3-D hermetic package in a very low bonding temperature (120°C) for MEMS (Micro-electro-mechanical Systems) devices. Microcavities were etched on a host glass wafer and were bonded with a carrier silicon wafer. MicroChem SU-8 photoresist is used as the intermediate adhesive layer between the host and carrier wafer. The devices were fabricated by self-aligning etching technique and were finally sealed by coating the structures with sputtered aluminum. Helium leak testing is carried out to verify the hermetic characteristics of the package, 99.7% of the tested devices were qualified. This technology shows a significant improvement of the hermeticity properties of adhesive bonded cavities, making it particularly suitable for applications on gas-tightness with low temperature, non-aggressive demands.

Low Temperature Wafer Bonding Process Using Sol-Gel Intermediate Layer

2004 ◽  
Author(s):  
S. S. Deng ◽  
J. Wei ◽  
C. M. Tan ◽  
W. B. Yu ◽  
S. M. L. Nai ◽  
...  
Keyword(s):  
Low Temperature ◽  
Bond Strength ◽  
Silicon Wafer ◽  
Process Parameters ◽  
Wafer Bonding ◽  
Intermediate Layer ◽  
Bonding Temperature ◽  
Sol Gel ◽  
Dominant Factor ◽  
Bond Quality

Silicon-to-silicon wafer bonding has been successful prepared using sol-gel intermediate layer, which is deposited by spinning acid catalyzed tetraethylthosilicate (TEOS) solution on both two silicon wafer surfaces. To investigate the effects of the process parameters, Draper-Lin small composite design is used, as it requires the minimum runs in the design of experiments. Four process parameters, bonding temperature, solution PH value, solution concentration and solution aging time, have been considered to influence the bond quality, including bond efficiency and bond strength. The bond efficiency is in the range of 40%–90% and bond strength is up to 35 MPa. Statistic analysis shows that the bonding temperature is the dominant factor for the bond quality, while the interaction between temperature and concentration is significant on bond strength. Various characterization techniques, including differential thermal analysis (DTA), atomic force microscopy (AFM), scanning electron microscope (SEM), contact angle measurement and ellipsometry, have been used to study the surface and interface properties. The residual organic species inside the sol-gel coating may be the origin of the significant effect of bonding temperature on the bond efficiency. The interaction effect on bond strength is attributed to the surface hydrophilicity and porosity of sol-gel coating. Higher concentration solution can form lower hydrophilic wafer surface, which results in lower bond strength when bonding temperature is at low level. Whereas, at high bonding temperatures, the increase of porosity of the sol-gel coating prepared by higher sol concentration can absorb more undesired hydrocarbon gas molecules and lead to higher bond strength. The bonding mechanism for the low temperature sol-gel intermediate layer bonding technique is related to the smooth coating surface, porous intermediate layer and water-absent bonding groups.

Research on Low Temperature Anodic Bonding Based on Interface Pretreatment of Dielectric Barrier Discharge Plasma

2015 ◽  
Vol 645-646 ◽  
pp. 356-361
Author(s):  
Ming Qiang Pan ◽  
Lin Ning Sun ◽  
Yang Jun Wang ◽  
Ji Zhu Liu ◽  
Tao Chen ◽  
...  
Keyword(s):  
Low Temperature ◽  
Dielectric Barrier Discharge ◽  
Barrier Discharge ◽  
Bonding Temperature ◽  
Anodic Bonding ◽  
Experimental Result ◽  
Dbd Plasma ◽  
Intimate Contact ◽  
Dielectric Barrier ◽  
Barrier Discharge Plasma

A simple composite bonding that combines dielectric barrier discharge (DBD) plasma activation with anodic bonding has been developed to achieve strong silicon/glass bonding at low temperature. The realization of low temperature bonding is attributed to enhance the hydrophilicity and smooth of silicon and glass surfaces and form lots of free radical after the DBD plasma (including-OH, -H, O, and heat) reacts with the interfaces. And these further reduce the difficulty of chemical bond switching, and improve the speed of the intimate contact formation. The experimental result show that the bonding temperature strongly decreased 100°C by using composite anodic bonding with DBD pretreatment which strength kept constant, and 10MPa bonding strength was obtained at 250°C/900V after the bonding interface was treated for 10s under the conditions of AC1.5KV/25KHz and the clearance 100μm.

scholarly journals Research on the Glass Silicon Anodic Direct Bonding Parameters

2015 ◽  
Vol 16 (2) ◽  
pp. 291
Author(s):  
Jia Li ◽  
Guo Hao ◽  
Guo Zhiping ◽  
Miao Shujing
Keyword(s):  
Wafer Bonding ◽  
Bonding Temperature ◽  
Bonding Time ◽  
Anodic Bonding ◽  
Bonding Quality ◽  
Mems Packaging ◽  
Bonding Parameters ◽  
Test Platform ◽  
Wafer Size

<p>By MEMS packaging test platform for bonding process of bonding temperature and bonding time,and test silicon specifications experimental study.Firstly,according to the anodic bonding principle,the main factors to detemine the effect of bonding quality.Secodly,change the bonding temperature,bonding time,and test wafer size and other parameters,glass silicon bonding contrast test.Finally,the calculation and analysis of comparative test of each group is bonded porosity,summanrized the factors that affect the quality of the bonding and bonding to achieve the best results in the bonding conditions.Experimental results indicate that when the bonding voltage of 1200V,bonding temperature of 445-455c,bonding time is 60s,the void fractin is less than 5%.Glass and Silicon wafer bonding quality can achieve the best. The experimental results in order to improve the glass silicon bonding quaity provides the basis.</p>

Optimization of Diffusion Bonding Process Parameters of Aluminium AA6061-Fly Ash Composites using Taguchi Method

2017 ◽  
Vol 9 (4) ◽  
Author(s):  
A. Sittaramane ◽  
G. Mahendran
Keyword(s):  
Fly Ash ◽  
Taguchi Method ◽  
Process Parameters ◽  
Diffusion Bonding ◽  
Bonding Strength ◽  
Bonding Temperature ◽  
Bonding Process ◽  
Bonding Pressure ◽  
Bonding Parameters ◽  
Response Table

This paper focused to determine optimal bonding parameters based on Taguchi method for maximizing bonding strength. The experiments were conducted on diffusion bonding machine using aluminium fly ash (AFA) composites. Three bonding parameters such as temperature, pressure and time, each at three levels were examined. Taguchi L27 orthogonal array was used as a design of experiment. The response table and the analysis of variance (ANOVA) were calculated to determine which process parameters significantly affect the bonding strength and also the % contribution of each parameter. The results show that the combination of factors and their levels of A2B3C3 i.e. the bonding done at a temperature of 475°C with a pressure of 10 MPa and time for 20 minutes yielded the optimum i.e. maximum bonding strength. Finally, ANOVA results indicated that all three process parameters significantly affected the bonding strength with a maximum contribution from the bonding temperature (85.93%), followed by bonding time (12.6%) and bonding pressure (1.48%). It is also observed that the bonding strength of the diffusion bonding process can be improved effectively through this approach.

Sol-Gel Coating Facilitating Si-to-Si Wafer Bonding at Low Temperature

2005 ◽  
Author(s):  
J. Wei ◽  
S. S. Deng ◽  
C. M. Tan
Keyword(s):  
Low Temperature ◽  
Bond Strength ◽  
Wafer Bonding ◽  
Intermediate Layer ◽  
Bonding Temperature ◽  
Sol Gel ◽  
Bond Quality ◽  
Bubble Generation ◽  
High Bond ◽  
High Bond Strength

Silicon-to-silicon wafer bonding by sol-gel intermediate layer has been performed using acid-catalyzed tetraethylthosilicate-ethanol-water sol solution. High bond strength near to the fracture strength of bulk silicon is obtained at low temperature, for example 100°C. However, The bond efficiency and bond strength of this intermediate layer bonding sharply decrease when the bonding temperature increases to elevated temperature, such as 300 °C. The degradation of bond quality is found to be related to the decomposition of residual organic species at elevated bonding temperature. The bubble generation and the mechanism of the high bond strength at low temperature are exploited.

Sign in / Sign up

Export Citation Format

Share Document