Optimization of Micro Drilling Process

2020 ◽  
pp. 97-110
Author(s):  
Apoorva Shastri ◽  
Aniket Nargundkar ◽  
Anand J. Kulkarni
Keyword(s):  
Drilling Process ◽  
Micro Drilling

Economic parameter design for ultra-fast laser micro-drilling process

2019 ◽  
Vol 57 (20) ◽  
pp. 6292-6314 ◽  
Author(s):  
Jianjun Wang ◽  
Yizhong Ma ◽  
Fugee Tsung ◽  
Gang Chang ◽  
Yiliu Tu
Keyword(s):  
Parameter Design ◽  
Drilling Process ◽  
Economic Parameter ◽  
Micro Drilling

The Downsizing Effects in EDM Drilling of Micro Holes

2013 ◽  
Vol 549 ◽  
pp. 503-510 ◽  
Author(s):  
Gianluca D'Urso ◽  
Giancarlo Maccarini ◽  
C. Merla
Keyword(s):  
Electrical Discharge Machining ◽  
Steel Plates ◽  
Drilling Process ◽  
Micro Edm ◽  
Micro Electrical Discharge Machining ◽  
Micro Holes ◽  
Micro Drilling ◽  
Micro Features ◽  
Electron Microscopes ◽  
Manufacturing Technologies

The recent miniaturization trend in manufacturing, has enhanced the production of new and highly sophisticated systems in various industrial fields. In recent years, machining of the so called difficult to cut materials has become an important issue in several sectors. Micro Electrical Discharge Machining (micro-EDM) thanks to its contactless nature, is one of the most important technologies for the machining of this type of materials and it can be considered as one of the most promising manufacturing technologies for the fabrication of micro components. One of the most relevant applications of micro-EDM is micro-drilling. Micro holes in fact, are widely used for example in micro-electromechanical systems (MEMS), serving as channels or nozzles to connect two micro-features, and in micro-mechanical components. The present study is about micro drilling of metal plates by means of micro-EDM technology. In particular, the aim of this work is to investigate the effects of the downsizing of the micro holes diameter on the drilling performances. The influence of the reduction of the diameters in terms of both process performances (e.g., tool wear, taper rate, diametrical overcut) and general quality of the holes was investigated. Steel plates having thickness equal to 0.8 mm were taken into account. The drilling process was carried out using a micro-EDM machine Sarix SX 200 with carbide electrodes having diameter equal to 300, 200, 100 and 50 μm. Since the standard electrodes adopted in this study had a diameter equal to 300 μm, a wire EDM unit was used to obtain the other electrodes. The relationship between the process parameters considered the most significant and the final output, was studied. Furthermore, the geometrical and dimensional properties of the micro-holes were analyzed using both optical and scanning electron microscopes. In particular, it is demonstrated that the diameter size has a significant influence on the final value of the diametrical overcut while peak current and frequency parameters have a negligible effect.

Manufacturing Quality Control Method Based on Bayesian Network Model

2010 ◽  
Vol 450 ◽  
pp. 292-295
Author(s):  
Ye Hong Dong ◽  
Dong Xiang ◽  
Guang Hong Duan
Keyword(s):  
Quality Control ◽  
Bayesian Network ◽  
Model Building ◽  
Control Method ◽  
Drilling Process ◽  
Quality Prediction ◽  
Shewhart Control ◽  
Drilling Quality ◽  
Micro Drilling ◽  
Manufacturing Mode

In order to address the problem of quality control faced in multi-type and small-batch manufacturing mode, the method based on Bayesian Network (BN) is proposed. The building, learning and evolving method as well as the quality prediction and diagnosis method of BN model are described in this paper. The combination of BN model and Shewhart control chart is also mentioned. The model building and evolving method was conducted in PCB micro-drilling process as example, verifying that the prediction accuracy increases with the evolved model. The drilling quality prediction was compared with that obtained through regression analysis and artificial neural network. The advantage of BN model in advanced manufacturing is proved.

Time and Frequency Domain Investigation of the Static and Dynamic Characteristics of Micro-Drilling

Manufacturing ◽  
2003 ◽  
Author(s):  
Anping Guo ◽  
Steve Batzer ◽  
John Roth
Keyword(s):  
Tool Wear ◽  
Dynamic Characteristics ◽  
Time History ◽  
Drilling Process ◽  
Dynamic Features ◽  
Proper Order ◽  
Micro Drilling ◽  
On Line ◽  
Wear Monitoring ◽  
Dynamic Time

In this paper, the dynamic characteristics of micro-drilling process under different cutting conditions and the resulting correlation to tool wear have been studied. Two types of drills, three spindle speeds and two kinds of workpiece materials were used. In-process cutting forces and accelerations were measured. The signals were analyzed in both the time and frequency domains. Some interesting phenomena were observed in the dynamic time-history response during drilling. Progressive functions with the proper order were obtained to describe the curve of the average thrust force with the number of the holes drilled. Dynamic features which were sensitive to tool wear were found. The changing trends of these dynamic features as the drill wear progresses show a feasibility to develop an on-line drill wear monitoring system by evaluating the changes in dynamic features.

Micro-drilling process control by using adaptive sliding controller

2014 ◽  
Vol 31 (2) ◽  
pp. 201-215
Author(s):  
Hung-Yi Chen
Keyword(s):  
Process Control ◽  
Controller Design ◽  
Sliding Mode ◽  
Learning Ability ◽  
Sliding Mode Controller ◽  
Drilling Process ◽  
Time Varying ◽  
Content Type ◽  
Micro Drilling ◽  
Fuzzy Compensator

Purpose – Recently, the micro-positioning technology has become more important for achieving the requirement of precision machinery. The piezo-actuator plays a very important role in this application area. A model-free adaptive sliding controller with fuzzy compensation is proposed for a piezo-actuated micro-drilling process control in this paper. The paper aims to discuss these issues. Design/methodology/approach – Due to the system's nonlinear and time-varying characteristics, this control strategy employs the functional approximation technique to establish the unknown function for releasing the model-based requirement of the sliding mode control. In addition, a fuzzy scheme with online learning ability is augmented to compensate for the finite approximation error and facilitate the controller design. Findings – The Lyapunov direct method can be applied to find adaptive laws for updating coefficients in the approximating series and tuning parameter in the fuzzy compensator to guarantee the control system stability. With the addition adaptive fuzzy compensator, as less as five Fourier series functions can be used to approximate the nonlinear time-varying function for designing a sliding mode controller for micro-drilling process control. Originality/value – The important advantages of this approach are to achieve the sliding mode controller design without the system dynamic model requirement and release the trial-and-error work of selecting approximation function.

A Study on Machining and Environmental Characteristics of Micro-Drilling Process Using Nanofluid Minimum Quantity Lubrication

2011 ◽  
Author(s):  
Jung Soo Nam ◽  
Pil-Ho Lee ◽  
Sang Won Lee
Keyword(s):  
Experimental Studies ◽  
Minimum Quantity Lubrication ◽  
Compressed Air ◽  
Drilling Process ◽  
Environmental Characteristics ◽  
Minimum Quantity ◽  
System A ◽  
Micro Drilling ◽  
Nanofluid Minimum Quantity Lubrication ◽  
Oil Mist

This paper presents two basic experimental studies of a micro-drilling process with nanofluid minimum quantity lubrication (MQL) in terms of machining and environmental characteristics. By using a miniaturized desktop machine tool system, a series of micro drilling experiments were conducted in the cases of dry, compressed air and nanofluid MQL. The experimental results imply that nanofluid MQL significantly reduces the adhesion of chips when compared with the cases of dry and compressed air micro-drilling. As a result, it is observed that the magnitudes of average drilling torque and thrust force are decreased and the tool life of micro drills is extended in the case of nanofluid MQL micro-drilling process. In addition, the empirical study on environmental characteristics of MQL micro-drilling process is conducted by measuring MQL oil mist with the oil sampling method. The results show that remaining MQL oil mist is tiny enough not to have a detrimental effect on human health.

Effect of Rapid-Feed Step-Drilling Cycle and Super-High-Speed Spindle for High-Speed Micro Drilling in Printed Wiring Boards

2010 ◽  
Vol 447-448 ◽  
pp. 836-840 ◽  
Author(s):  
Eiichi Aoyama ◽  
Toshiki Hirogaki ◽  
Keiji Ogawa ◽  
Satoshi Nojiri ◽  
Yutaka Takeda
Keyword(s):  
High Speed ◽  
Drilling Process ◽  
Printed Wiring Boards ◽  
Step Method ◽  
Processing Efficiency ◽  
High Productivity ◽  
Micro Holes ◽  
Drilling Quality ◽  
Micro Drilling ◽  
Drilling Conditions

A drilling technique using micro-drills of 0.2 mm or less in diameter and a super-high-speed spindle of 160000 rpm or more has been developed for drilling ultra-micro holes in printed wiring boards (PWBs). The drilling process requires higher reliability and quality to maintain the reliability of the electrical connection between circuit layers. On the other hand, higher processing efficiency is also required in PWBs manufacturing. To maintain high productivity, drilling is normally performed using a non-step method, but heat damage called B-RING occurs around the drilled holes with this method. To solve these problems without the loss of processing efficiency, we applied the rapid-feed step-drilling cycle method. We investigated the B-RING for drilling quality and evaluated the drilling time for processing efficiency under various drilling conditions. We found that using a rapid-feed step-drilling cycle with an appropriate number of steps and feed rates ensures a higher level of hole quality and processing efficiency compared with the conventional non-step drilling.

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