Addressing the Challenges in Laser Micro-Machining and Bonding of Silicon Microchannel Cold-Plate and 3D-Manifold for Embedded Cooling Applications: Perfect Debris Removal

2019 ◽  
Author(s):  
Sougata Hazra ◽  
Ki Wook Jung ◽  
Madhusudan Iyengar ◽  
Chris Malone ◽  
Mehdi Asheghi ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Hierarchical Structures ◽  
Machining Process ◽  
Silicon Substrates ◽  
Post Process ◽  
Debris Removal ◽  
Commercial Applications ◽  
Substrate Surfaces ◽  
Uv Lasers ◽  
Microfabrication Techniques

Abstract Laser machining is an inexpensive and fast alternative to conventional microfabrication techniques that produce complicated three-dimensional, hierarchical structures. One of the major issues plaguing the use of laser micromachining to manufacture commercially usable devices is the formation of debris during cutting and the difficulty in removing these debris efficiently after the machining process. For silicon substrates, this debris can interfere with surrounding components and cause problems during bonding with other substrates by preventing uniform conformal contact. This study summarizes several post-process techniques that can be employed for complete debris removal during etching of Silicon samples using an Nd/YVO4 pulsed (∼ 1–3 kW) UV laser, detailing the advantages and drawbacks of each approach. A method that was found to be particularly promising to achieve very smooth surfaces with almost complete debris removal was the use of PDMS as a high rigidity protective coating. In the process, a novel technique to strip PDMS from Silicon surface was developed and a study was carried out to optimize the process. The result of this study is very valuable to the microfabrication industry where smooth and clean substrate surfaces are highly desirable. This work could facilitate adoption and significant improvements to the process of using UV lasers to create microstructures for commercial applications as well as in a research environment.

Thermal and Manufacturing Design Considerations for Silicon-Based Embedded Microchannel Three-Dimensional-Manifold Coolers (EMMC)—Part 3: Addressing Challenges in Laser Micromachining-Based Manufacturing of Three-Dimensional-Manifolded Microcooler Devices

2020 ◽  
Vol 142 (3) ◽  
Author(s):  
Sougata Hazra ◽  
Ki Wook Jung ◽  
Madhusudan Iyengar ◽  
Chris Malone ◽  
Mehdi Asheghi ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Hierarchical Structures ◽  
Laser Micromachining ◽  
Machining Process ◽  
Dimensional Manifold ◽  
Debris Removal ◽  
Commercial Applications ◽  
Substrate Surfaces ◽  
Silicon Based ◽  
Uv Lasers

Abstract Laser machining is an inexpensive and fast alternative to conventional microfabrication techniques and has the capability to produce complicated three-dimensional (3D), hierarchical structures. It is especially important while performing rapid prototyping and quick design studies of extreme heat flux cooling devices. One of the major issues plaguing the use of laser micromachining to manufacture commercially usable devices, is the formation of debris during cutting and the difficulty in removing these debris efficiently after the machining process. For silicon substrates, this debris can interfere with surrounding components and cause problems during bonding with other substrates by preventing uniform conformal contact. This study delves deep into the challenges faced and methods to overcome them during laser micromachining-based manufacturing of such complicated 3D-manifolded microcooler structures. Specifically, this work summarizes several postprocess techniques that can be employed for complete debris removal during etching of silicon samples using an Nd/YVO4 ultraviolet (UV) laser, detailing the advantages and drawbacks of each approach. A method that was found to be particularly promising to achieve very smooth surfaces with almost complete debris removal was the use of polydimethylsiloxane (PDMS) as a high-rigidity protective coating. In the process, a novel technique to strip PDMS from silicon surface was also developed. The result of this study is valuable to the microfabrication industry where smooth and clean substrate surfaces are highly desirable and it will significantly improve the process of using UV lasers to create microstructures for commercial applications as well as in a research environment.

scholarly journals Polymer cyclization for the emergence of hierarchical nanostructures

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Chaojian Chen ◽  
Manjesh Kumar Singh ◽  
Katrin Wunderlich ◽  
Sean Harvey ◽  
Colette J. Whitfield ◽  
...  
Keyword(s):  
Self Assembly ◽  
Three Dimensional ◽  
Hierarchical Structures ◽  
Structural Similarity ◽  
Vital Role ◽  
Nanomaterial Synthesis ◽  
Wide Range ◽  
Linear Poly ◽  
Polymer Folding ◽  
Dynamics Simulations

AbstractThe creation of synthetic polymer nanoobjects with well-defined hierarchical structures is important for a wide range of applications such as nanomaterial synthesis, catalysis, and therapeutics. Inspired by the programmability and precise three-dimensional architectures of biomolecules, here we demonstrate the strategy of fabricating controlled hierarchical structures through self-assembly of folded synthetic polymers. Linear poly(2-hydroxyethyl methacrylate) of different lengths are folded into cyclic polymers and their self-assembly into hierarchical structures is elucidated by various experimental techniques and molecular dynamics simulations. Based on their structural similarity, macrocyclic brush polymers with amphiphilic block side chains are synthesized, which can self-assemble into wormlike and higher-ordered structures. Our work points out the vital role of polymer folding in macromolecular self-assembly and establishes a versatile approach for constructing biomimetic hierarchical assemblies.

scholarly journals In-Process Measurement of Three-Dimensional Deformations Based on Speckle Photography

2021 ◽  
Vol 11 (11) ◽  
pp. 4981
Author(s):  
Andreas Tausendfreund ◽  
Dirk Stöbener ◽  
Andreas Fischer
Keyword(s):  
Evaluation Method ◽  
Process Analysis ◽  
Plane Deformation ◽  
Three Dimensional ◽  
Machining Process ◽  
Image Correlation ◽  
Speckle Photography ◽  
Process Measurement ◽  
Out Of Plane ◽  
Plane Deformations

In the concept of the process signature, the relationship between a material load and the modification remaining in the workpiece is used to better understand and optimize manufacturing processes. The basic prerequisite for this is to be able to measure the loads occurring during the machining process in the form of mechanical deformations. Speckle photography is suitable for this in-process measurement task and is already used in a variety of ways for in-plane deformation measurements. The shortcoming of this fast and robust measurement technique based on image correlation techniques is that out-of-plane deformations in the direction of the measurement system cannot be detected and increases the measurement error of in-plane deformations. In this paper, we investigate a method that infers local out-of-plane motions of the workpiece surface from the decorrelation of speckle patterns and is thus able to reconstruct three-dimensional deformation fields. The implementation of the evaluation method enables a fast reconstruction of 3D deformation fields, so that the in-process capability remains given. First measurements in a deep rolling process show that dynamic deformations underneath the die can be captured and demonstrate the suitability of the speckle method for manufacturing process analysis.

Solid and Hollow Micro and Nano Spherical Structures: in Polysilicon and Phosphosilicate Glass

1994 ◽  
Vol 372 ◽  
Author(s):  
M. M. Farooqui ◽  
A. G. R. Evans
Keyword(s):  
Ion Beam ◽  
Three Dimensional ◽  
Optical Components ◽  
Circular Symmetry ◽  
Spherical Structures ◽  
Phosphosilicate Glass ◽  
Micro Systems ◽  
Micro Structures ◽  
Microfabrication Techniques

Fabrication of three dimensional micro structures in silicon and silicon related materials is becoming increasingly important for the realisation of micro systems comprising of sensors, actuators, transducers and analytical assemblies. Fabrication of such devices so far has been mostly in form of structures defined by the crystal planes of silicon, or has involved sophisticated technologies such as ion beam machining, replication using LIGA, or micromachining techniques involving a sequence of alignment and etch stages using binary masks. Structures with circular symmetry are of great interest as micro optical components amongst others, and these are not easily amenable to microfabrication techniques commonly employed.

COMBINED EFFECT OF MECHANICAL GROOVING AND STAIN-ETCHED SURFACE ON OPTICAL AND ELECTRICAL PROPERTIES OF CRYSTALLINE SILICON SUBSTRATES

2014 ◽  
Vol 21 (03) ◽  
pp. 1450041 ◽  
Author(s):  
AHMED ZARROUG ◽  
LOTFI DERBALI ◽  
RACHID OUERTANI ◽  
WISSEM DIMASSI ◽  
HATEM EZZAOUIA
Keyword(s):  
Crystalline Silicon ◽  
Light Trapping ◽  
Front Surface ◽  
Minority Carrier Lifetime ◽  
Combined Effect ◽  
Machining Process ◽  
Silicon Substrates ◽  
Textured Surface ◽  
Crystalline Silicon Solar Cell ◽  
Simple Method

This paper investigates the combined effect of mechanical grooving and porous silicon (PS) on the front surface reflectance and the electronic properties of crystalline silicon substrates. Mechanical surface texturization leads to reduce the cell reflectance, enhance the light trapping and augment the carrier collection probability. PS was introduced as an efficient antireflective coating (ARC) onto the front surface of crystalline silicon solar cell. Micro-periodic V-shaped grooves were made by means of a micro-groove machining process prior to junction formation. Subsequently, wafers were subjected to an isotropic potassium hydroxide ( KOH ) etching so that the V-shape would be turned to a U-shape. We found that the successive treatment of silicon surfaces with stain-etching, grooving then alkaline etching enhances the absorption of the textured surface, and decreases the reflectance from 35% to 7% in the 300–1200 nm wavelength range. We obtained a significant increase in the overall light path that generates the building up of the light trapping inside the substrate. We found an improvement in the illuminated I–V characteristics and an increase in the minority carrier lifetime τeff. Such a simple method was adopted to effectively reinforce the overall device performance of crystalline silicon-based solar cells.

Development of Machining Method for Micromold

2010 ◽  
Vol 154-155 ◽  
pp. 310-313
Author(s):  
Xue Feng Bi ◽  
Jin Sheng Wang ◽  
Jia Shun Shi ◽  
Ya Dong Gong
Keyword(s):  
Tool Path ◽  
Simulation Software ◽  
Machining Process ◽  
Machining Parameters ◽  
Machining Simulation ◽  
Post Process ◽  
Micro Parts ◽  
G Code ◽  
Micro Machine ◽  
3D Software

Micromold manufacturing technology is very important for the mass production of micro parts. In this paper, modeling of micromold is established in 3D software firstly. The 3D modeling is input into machining simulation software Master CAM to simulate machining process. The machining parameters and cutting tool path are optimized in machining simulation. Machining G code of micromold obtained from post-process program of Master CAM is input into HMI system of Micro Machine Tool (MMT), and hence the micromold will be machined precisely in MMT.

An Approach to Generate Three Dimensional Machining Process Model According to Information from Design Model Based on Definition

2016 ◽  
Vol 693 ◽  
pp. 1684-1692 ◽  
Author(s):  
Hong Lei Zhang ◽  
Wen He Liao ◽  
Yu Guo ◽  
Wen An Yang
Keyword(s):  
Process Model ◽  
Three Dimensional ◽  
Design Model ◽  
Machining Process ◽  
Model Generation ◽  
Geometric Models ◽  
Model Based

Faced with the problem of generation for 3D machining process model, an approach to generate three dimensional machining process model according to information from design model based on definition is proposed. Compared with the existing methods, the approach utilizes multiple information of design model based on definition and takes many phases into consideration of 3D process model generation. The structure of 3D machining process model is defined and the course of 3D process model generation is researched, including multiple information acquirement, generation of procedure geometric models and annotation. Finally, the framework of system and application for 3D machining process model generation are presented for validation purposes.

3D-to-2D Mapping of Cutter Paths in NC Programming of Complex Engineering Parts

1993 ◽  
Author(s):  
Chao-Hwa Chang
Keyword(s):  
Three Dimensional ◽  
Machining Process ◽  
Milling Machine ◽  
Systematic Method ◽  
Nc Programming ◽  
Cutter Path ◽  
Nc Milling ◽  
Complex Engineering ◽  
High Level ◽  
Mapping Concept

Abstract The concept of mapping a three dimensional (3D) contouring cutter path with major motion in a plane parallel to the Z axis onto the X-Y plane or one perpendicular to the Z axis is introduced. A systematic method is developed that can be used to program, in APT or other high-level languages, complex contouring cutter motion based on the concept introduced. As a result, NC programming of contouring motion for many complex engineering parts on a 3-axis numerically controlled (NC) milling machine, which is often considered difficult, can be greatly simplified. Part examples are discussed; and the APT programs defining the cutter path based on the 3D-to-2D mapping concept, are also analyzed in detail. The concept and method introduced proved to be a powerful tool for programming the NC machining process for many parts, particularly dies and molds.

scholarly journals Analysis of Forces in Vibro-Impact and Hot Vibro-Impact Turning of Advanced Alloys

2011 ◽  
Vol 70 ◽  
pp. 315-320 ◽  
Author(s):  
Riaz Muhammad ◽  
Agostino Maurotto ◽  
Anish Roy ◽  
Vadim V. Silberschmidt
Keyword(s):  
Finite Element ◽  
Cutting Forces ◽  
Three Dimensional ◽  
Element Model ◽  
Machining Process ◽  
Strain Rates ◽  
Machining Processes ◽  
Machined Surface ◽  
Cutting Zone

Analysis of the cutting process in machining of advanced alloys, which are typically difficult-to-machine materials, is a challenge that needs to be addressed. In a machining operation, cutting forces causes severe deformations in the proximity of the cutting edge, producing high stresses, strain, strain-rates and temperatures in the workpiece that ultimately affect the quality of the machined surface. In the present work, cutting forces generated in a vibro-impact and hot vibro-impact machining process of Ti-based alloy, using an in-house Ultrasonically Assisted Turning (UAT) setup, are studied. A three-dimensional, thermo-mechanically coupled, finite element model was developed to study the thermal and mechanical processes in the cutting zone for the various machining processes. Several advantages of ultrasonically assisted turning and hot ultrasonically assisted turning are demonstrated when compared to conventional turning.

scholarly journals Research on a 3-DOF Motion Device Based on the Flexible Mechanism Driven by the Piezoelectric Actuators

Micromachines ◽  
2018 ◽  
Vol 9 (11) ◽  
pp. 578 ◽  
Author(s):  
Bingrui Lv ◽  
Guilian Wang ◽  
Bin Li ◽  
Haibo Zhou ◽  
Yahui Hu
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Machining Process ◽  
Element Analysis ◽  
3D Motion ◽  
Compliance Modeling ◽  
The Matrix ◽  
Static Performance ◽  
Flexible Mechanism

This paper describes the innovative design of a three-dimensional (3D) motion device based on a flexible mechanism, which is used primarily to produce accurate and fast micro-displacement. For example, the rapid contact and separation of the tool and the workpiece are realized by the operation of the 3D motion device in the machining process. This paper mainly concerns the device performance. A theoretical model for the static performance of the device was established using the matrix-based compliance modeling (MCM) method, and the static characteristics of the device were numerically simulated by finite element analysis (FEA). The Lagrangian principle and the finite element analysis method for device dynamics are used for prediction to obtain the natural frequency of the device. Under no-load conditions, the dynamic response performance and linear motion performance of the three directions were tested and analyzed with different input signals, and three sets of vibration trajectories were obtained. Finally, the scratching experiment was carried out. The detection of the workpiece reveals a pronounced periodic texture on the surface, which verifies that the vibration device can generate an ideal 3D vibration trajectory.

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