Rapid Silicon-to-Steel Bonding via Inductive Heating

2006 ◽  
Author(s):  
Brian D. Sosnowchik ◽  
Liwei Lin ◽  
Albert P. Pisano
Keyword(s):  
Bonding Temperature ◽  
Surface Preparation ◽  
Fatigue Tests ◽  
Bonding Process ◽  
Inductive Heating ◽  
Sensor Applications ◽  
Mems Sensor ◽  
Sensing Applications ◽  
Minimal Damage ◽  
Point Bend

In this work, we present a rapid, low temperature process for the bonding of silicon to steel through the use of inductive heating for MEMS sensor applications. The bonding process takes as short as three seconds with a maximum bonding temperature as low as 230°C at the steel surface. The bonding strength is strong, and causes minimal damage to steel. The process has also been shown to work using leaded and leadfree bonding solder with minimal surface preparation to the steel. Four characterization experiments – tensile and compressive 4-point bend, axial extension, and fatigue tests – have been performed to validate the bonding process and materials. As such, this work illustrates the promise of applying inductive heating for the rapid silicon bonding to steel components for MEMS sensing applications.

Extending WLCSP Packaging Technology Capabilities to Enable Miniaturized Sensor and MEMS Packaging Applications

2016 ◽  
Vol 2016 (DPC) ◽  
pp. 000397-000420
Author(s):  
Ted Tessier
Keyword(s):  
Smart Phone ◽  
Cost Effective ◽  
Wearable Electronics ◽  
Wafer Level ◽  
Technology Infrastructure ◽  
Sensor Applications ◽  
Mems Sensor ◽  
Sensing Applications ◽  
Communication Devices ◽  
Multiple Sensor

WLCSP has been widely deployed in portable computing and communication devices for efficient die level packaging of integrated semiconductor and integrated passive applications. More recently with the proliferation of smart phone capabilities and applications as well as the emergence of Internet of Things and Wearable Electronics, MEMS and sensor devices in minimized package formats have become increasingly pervasive. These include image sensors, light sensors, finger print sensors as well as accelerometer, gyroscope and other MEMS motion sensing devices. It is predicted that the widespread adoption of WLCSP packaging for sensing applications will accelerate the proliferation of the incorporation of multiple sensor technologies within future communication devices. A number of these MEMS/Sensor applications have been able to leverage the existing WLCSP technology infrastructure and has led to opportunities to packaging and cost-effective standardization and miniaturization. On the other hand, some significant new changes to WLCSP process flows have also emerged that have had to be addressed. This paper will provide an overview of MEMS and Sensor applications that are currently or will use 2D, 2.5D or 3D wafer level packaging formats. Process enhancements including the ability to process thinner substrates with the adoption of temporary carrier technologies will also be highlighted.

scholarly journals Rapid Growth of TiO2 Nanoflowers via Low-Temperature Solution Process: Photovoltaic and Sensing Applications

Materials ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 566 ◽  
Author(s):  
M. Akhtar ◽  
Ahmad Umar ◽  
Swati Sood ◽  
InSung Jung ◽  
H. Hegazy ◽  
...  
Keyword(s):  
Low Temperature ◽  
Anatase Phase ◽  
Three Dimensional ◽  
Solution Process ◽  
Dye Sensitized Solar Cell ◽  
Sensor Applications ◽  
Dye Sensitized ◽  
Sensing Applications ◽  
Density Growth ◽  
Temperature Solution

This paper reports the rapid synthesis, characterization, and photovoltaic and sensing applications of TiO2 nanoflowers prepared by a facile low-temperature solution process. The morphological characterizations clearly reveal the high-density growth of a three-dimensional flower-shaped structure composed of small petal-like rods. The detailed properties confirmed that the synthesized nanoflowers exhibited high crystallinity with anatase phase and possessed an energy bandgap of 3.2 eV. The synthesized TiO2 nanoflowers were utilized as photo-anode and electron-mediating materials to fabricate dye-sensitized solar cell (DSSC) and liquid nitroaniline sensor applications. The fabricated DSSC demonstrated a moderate conversion efficiency of ~3.64% with a maximum incident photon to current efficiency (IPCE) of ~41% at 540 nm. The fabricated liquid nitroaniline sensor demonstrated a good sensitivity of ~268.9 μA mM−1 cm−2 with a low detection limit of 1.05 mM in a short response time of 10 s.

Quantum transport, electronic properties and molecular adsorptions in graphene

2021 ◽  
Vol 35 (08) ◽  
pp. 2130001
Author(s):  
Yoshitaka Fujimoto
Keyword(s):  
Electronic Properties ◽  
Quantum Transport ◽  
Density Functional ◽  
Field Effect Transistors ◽  
Electronic Conductivity ◽  
Volume Ratio ◽  
Functional Study ◽  
Sensor Applications ◽  
Sensing Applications ◽  
High Electronic Conductivity

Molecular sensor applications are used in different fields including environmental monitoring and medical diagnosis. Graphene, a single atomic layer consisting of the hexagonally arranged carbon material, is one of the most promising materials for ideal channels in field-effect transistors to be used as electronic sensing applications owing to its lightweight, mechanical robustness, high electronic conductivity and large surface-to-volume ratio. This paper provides a review of molecular adsorptions, electronic properties and quantum transport of graphene based on the first-principles density-functional study. The adsorption properties of environmentally polluting or toxic molecules and electronic transport of graphene are revealed. The possibility of detecting these molecules selectively is also discussed for designing the graphene-based sensor applications.

Fabrication of large area nanogap electrodes for sensing applications

2013 ◽  
Vol 1530 ◽  
Author(s):  
A. Bendavid ◽  
L. Wieczorek ◽  
R. Chai ◽  
J. S. Cooper ◽  
B. Raguse
Keyword(s):  
Large Scale ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Beam Current ◽  
Fabrication Method ◽  
Large Area ◽  
Sensor Applications ◽  
Sensing Applications ◽  
Lift Off ◽  
Nanogap Electrodes

ABSTRACTA large area nanogap electrode fabrication method combinig conventional lithography patterning with the of focused ion beam (FIB) is presented. Lithography and a lift-off process were used to pattern 50 nm thick platinum pads having an area of 300 μm × 300 μm. A range of 30-300 nm wide nanogaps (length from 300 μm to 10 mm ) were then etched using an FIB of Ga+ at an acceleration voltage of 30 kV at various beam currents. An investigation of Ga+ beam current ranging between 1-50 pA was undertaken to optimise the process for the current fabrication method. In this study, we used Monte Carlo simulation to calculate the damage depth in various materials by the Ga+. Calculation of the recoil cascades of the substrate atoms are also presented. The nanogap electrodes fabricated in this study were found to have empty gap resistances exceeding several hundred MΩ. A comparison of the gap length versus electrical resistance on glass substrates is presented. The results thus outline some important issues in low-conductance measurements. The proposed nanogap fabrication method can be extended to various sensor applications, such as chemical sensing, that employ the nanogap platform. This method may be used as a prototype technique for large-scale fabrication due to its simple, fast and reliable features.

Vacuum Adhesive Bonding and Stress Isolation for MEMS Resonant Pressure Sensor Package

2011 ◽  
Vol 694 ◽  
pp. 896-900 ◽  
Author(s):  
Yu Xin Li ◽  
De Yong Chen ◽  
Jun Bo Wang
Keyword(s):  
Pressure Sensor ◽  
Bonding Strength ◽  
Adhesive Bonding ◽  
Thermal Stresses ◽  
Time Pressure ◽  
Bonding Temperature ◽  
Bonding Process ◽  
Temperature Drift ◽  
Stress Isolation ◽  
Sensor Package

This paper presents a method of low temperature adhesive bonding and stress isolation for MEMS resonant pressure sensor hermetic packaging using non-photosensitive benzo-cyclo-butene (BCB) from Dow Co. According to the bonding process, pre-bake time, pumping time, pressure placed on the sensor and the thickness of crosslink layer are the most important factors. Stress isolation is designed to minimize thermal stresses to the resonant pressure sensor package. Experimental results show that this bonding process is a viable for MEMS resonant pressure sensor with the bonding temperature below 250°C, measured bonding strength more than 30MPa, the temperature drift less than 0.05%/°C in the range of -40°C to 70°C(10% of that without stress isolation), and the bonding strength maintains well after thermal treatments, handling, bench testing and implantations.

Characterization of Wafer Level Metal Thermo-Compression Bonding

2010 ◽  
Vol 2010 (DPC) ◽  
pp. 002326-002360
Author(s):  
Erkan Cakmak ◽  
Bioh Kim ◽  
Viorel Dragoi
Keyword(s):  
Surface Treatment ◽  
Metal Surface ◽  
Bonding Temperature ◽  
Transient Liquid Phase ◽  
Bonding Process ◽  
Bending Test ◽  
Strength Analysis ◽  
Mems Devices ◽  
Wafer Level ◽  
Bond Quality

The process of wafer-level bonding is being successfully used to form MEMS devices. Wafer level bonding may be realized by different methods such as thermo compression, transient liquid phase, anodic, glass frit, or polymer bonding. These methods have different requirements and the choice of wafer level bonding method is defined by the application type. Metal TCB has a wide variety of applications with materials of choice including Au, Cu and Al. 3D electrical connections are created by the use of Cu-Cu TCB; while CMOS MEMS devices may be realized by Al-Al TCB. In this study the wafer level bonding process of Cu-Cu and Al-Al TCB are characterized. The effects and significance of various bonding process parameters and surface treatment methods are reported on the final bond interfaces integrity and strength. Analysis methods include SAM, SEM, AFM, and four point bending test. Al-Al TCB samples were investigated on the interfacial adhesion energy and bond quality. IAE and bond quality were found to be positively correlated with bonding temperature. A bonding temperature of 500 °C or greater is necessary to obtain bond strengths of 8–10 J/m2. A positive relation between IAE and bonding temperature was observed for Cu-Cu TCB. IAE's of greater then 10 J/m2 were obtained on bonded samples that do not show a post bond residual seam on the bonding interface. An acid based pre treatment was shown to impact the surface properties of the initial metal surface hence affecting the IAE. Post bond annealing processes showed the most significant impact on the IAE of the Cu-Cu TCB system. To obtain comparable IAE values the Al-Al TCB method requires a higher bonding temperature. However the Cu-Cu TCB is sensitive to the initial metal surface condition and requires surface treatment processes prior to bonding to obtain high quality bonding results.

Low Temperature Wafer Level Bonding Using Benzocyclobutene Adhesive Polymers

2012 ◽  
Vol 2012 (DPC) ◽  
pp. 1-24
Author(s):  
Michael Gallagher ◽  
Jong-Uk Kim ◽  
Eric Huenger ◽  
Kai Zoschke ◽  
Christina Lopper ◽  
...  
Keyword(s):  
Low Temperature ◽  
Wafer Bonding ◽  
Flip Chip ◽  
Bonding Temperature ◽  
Bonding Process ◽  
Curing Temperature ◽  
Wafer Level ◽  
Mechanical Adhesion ◽  
3D Stacking ◽  
Dry Etch

3D stacking, one of the 3D integration technologies using through silicon vias (TSVs), is considered as a desirable 3D solution due to its cost effectiveness and matured technical background. For successful 3D stacking, precisely controlled bonding of the two substrates is necessary, so that various methods and materials have been developed over the last decade. Wafer bonding using polymeric adhesives has advantages. Surface roughness, which is critical in direct bonding and metal-to-metal bonding, is not a significant issue, as the organic adhesive can smooth out the unevenness during bonding process. Moreover, bonding of good quality can be obtained using relatively low bonding pressure and low bonding temperature. Benzocyclobutene (BCB) polymers have been commonly used as bonding adhesives due to their relatively low curing temperature (~250 °C), very low water uptake (<0.2%), excellent planarizing capability, and good affinity to Cu metal lines. In this study, we present wafer bonding with BCB at various conditions. In particular, bonding experiments are performed at low temperature range (180 °C ~ 210 °C), which results in partially cured state. In order to examine the effectiveness of the low temperature process, the mechanical (adhesion) strength and dimensional changes are measured after bonding, and compared with the values of the fully cured state. Two different BCB polymers, dry-etch type and photo type, are examined. Dry etch BCB is proper for full-area bonding, as it has low degree of cure and therefore less viscosity. Photo-BCB has advantages when a pattern (frame or via open) is to be structured on the film, since it is photoimageable (negative tone), and its moderate viscosity enables the film to sustain the patterns during the wafer bonding process. The effect of edge beads at the wafer rim area and the soft cure (before bonding) conditions on the bonding quality are also studied. Alan/Rey ok move from Flip Chip and Wafer Level Packaging 1-6-12.

scholarly journals Large-Area Thermal Distribution Sensor Based on Multilayer Graphene Ink

Sensors ◽  
2020 ◽  
Vol 20 (18) ◽  
pp. 5188
Author(s):  
Tomi Koskinen ◽  
Taneli Juntunen ◽  
Ilkka Tittonen
Keyword(s):  
Signal To Noise Ratio ◽  
Graphene Film ◽  
Multilayer Graphene ◽  
Wearable Electronics ◽  
Large Area ◽  
Sensor Applications ◽  
Thermal Distribution ◽  
Sensing Applications ◽  
Detection Of Objects ◽  
Distribution Mapping

Emergent applications in wearable electronics require inexpensive sensors suited to scalable manufacturing. This work demonstrates a large-area thermal sensor based on distributed thermocouple architecture and ink-based multilayer graphene film. The proposed device combines the exceptional mechanical properties of multilayer graphene nanocomposite with the reliability and passive sensing performance enabled by thermoelectrics. The Seebeck coefficient of the spray-deposited films revealed an inverse thickness dependence with the largest value of 44.7 μV K−1 at 78 nm, which makes thinner films preferable for sensor applications. Device performance was demonstrated by touch sensing and thermal distribution mapping-based shape detection. Sensor output voltage in the latter application was on the order of 300 μV with a signal-to-noise ratio (SNR) of 35, thus enabling accurate detection of objects of different shapes and sizes. The results imply that films based on multilayer graphene ink are highly suitable to thermoelectric sensing applications, while the ink phase enables facile integration into existing fabrication processes.

Low Temperature Direct Cu-Cu Immersion Bonding for 3D Integration

2009 ◽  
Vol 1156 ◽  
Author(s):  
Rahul Agarwal ◽  
Wouter Ruythooren
Keyword(s):  
Citric Acid ◽  
Low Temperature ◽  
Bonding Temperature ◽  
Atmospheric Condition ◽  
High Strength ◽  
Bonding Process ◽  
3D Integration ◽  
Temperature And Pressure ◽  
Low Temperature Bonding

AbstractHigh yielding and high strength Cu-Cu thermo-compression bonds have been obtained at temperatures as low as 175°C. Plated Cu bumps are used for bonding, without any surface planarization step or plasma treatment, and bonding is performed at atmospheric condition. In this work the 25μm diameter bumps are used at a bump pitch of 100μm and 40μm. Low temperature bonding is achieved by using immersion bonding in citric acid. Citric acid provides in-situ cleaning of the Cu surface during the bonding process. The daisy chain electrical bonding yield ranges from 84%-100% depending on the bonding temperature and pressure.

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