Investigation of Step Micro-Drilling Motion Based on Modeling of High Speed Spindle Driving Axis on Machine Tools Equipped with Vibration-Proof Mechanism

2014 ◽  
Vol 1017 ◽  
pp. 642-647
Author(s):  
Tatsuya Yamashita ◽  
Toshiki Hirogaki ◽  
Eiichi Aoyama ◽  
Ryousuke Shibata ◽  
Keiji Ogawa
Keyword(s):  
High Speed ◽  
Electrical Circuit ◽  
Drilling Process ◽  
Printed Wiring Boards ◽  
Proposed Model ◽  
Drilling Method ◽  
Drilling Technology ◽  
Micro Drilling ◽  
Increasing Demand ◽  
Balance Mechanism

Recently, there has been an increasing demand for miniaturization and multi-functionalization of electronic equipments due to the developments in information technology (IT). Thus, the miniaturization of printed wiring boards (PWBs) and fabrication of highly dense electrical circuit layers are needed to realize the miniaturization and densification of the semiconductor package PWBs. Micro-drilling technology has been attracing attention to machine the electronic micro-through holes with an ultra-high-speed spindle, more than 160 krpm. However, problems have emerged; the drill tool bends and suffers breakage in the drilling process and the heat damage around the drilled hole after a drilling process occurs due to the increase in the drilling aspect ratio between hole depth and diameter. In general, a step feed drilling method is considered an effective way to solve these problems. However, short stroke alternating motion in the spindle axis is needed to do the step drilling process and its motion causes various kinds of vibration. We constructed a machine tool with a novel counter balance mechanism in the spindle driving Z-axis and investigated a model to estimate a proper balance mass for the step drilling process. We compared the frequency response results from a proposed model with the experimental ones, and discussed a control on vibration due to the counter balance mechanism. The results demonstrate that a proposed vibration proof method was found to reduce the vibration in high-speed step-micro-drilling motion and to improve the drilled hole quality and the efficiency of micro-drilling process in the PWB manufacturing fields.

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.

Optimization of Feed Speed and Stroke for Step Micro Hole Drilling of Printed Wiring Boards by Response Surface Method

2012 ◽  
Vol 523-524 ◽  
pp. 509-514 ◽  
Author(s):  
Naoya Noguchi ◽  
Toshiki Hirogaki ◽  
Eiichi Aoyama ◽  
Keiji Ogawa ◽  
Yutaka Takeda
Keyword(s):  
Response Surface ◽  
Response Surface Method ◽  
High Speed ◽  
Hole Drilling ◽  
Feed Speed ◽  
Printed Wiring Boards ◽  
Step Cycle ◽  
Stroke Length ◽  
Surface Method ◽  
Micro Drilling

There have been few reports dealing with the drilling of printed wiring boards (PWBs) with micro-drills that are smaller than 0.2 mm in diameter, and super-high-speed spindles that are higher than 160,000 rpm. In these cases, preventing the micro-drill from breaking and keeping the position accuracy of the drilled hole has been difficult. We therefore focus on the high-speed step-drilling method and short stroke as a novel way of resolving these problems. On the other hand, determining the complicated combination of feed speed, rapid feed speed, and stroke length is difficult. Under these backgrounds, in this report we propose a fast-feed step cycle that use fast-feed command without the processing feed. Thus, we attempted to apply the response surface method to optimize these parameters. As a result, a proposed method was found to be effective to improve the drilled hole quality and drilling efficiency in such kinds of micro-drilling of the PWBs.

scholarly journals About transition processes in blasthole drilling at quarries

2020 ◽  
Vol 177 ◽  
pp. 01008
Author(s):  
Andrey Regotunov ◽  
Rudolf Sukhov ◽  
Gennady Bersenyov
Keyword(s):  
Rock Properties ◽  
Repair System ◽  
Drilling Process ◽  
Transition Processes ◽  
Material Resources ◽  
Drilling Performance ◽  
Drilling Method ◽  
Drilling Technology ◽  
Drilling Operations ◽  
Main Transition

As a system, the mining enterprise develops under constantly changing conditions of the external and internal environment. These conditions affect the state of the most important drilling subsystem: blasthole drilling technology, safety, performance, power consumption of the boring rigs and roller bits used. The main transition processes as necessary responses of the subsystem to changing conditions were identified as a result of fragmentary data analysis showing decisions taken over the past 15-20 years, which increase drilling activity efficiency and safety of smaller quarries of Russia, which contain a significant amount of material resources. The main transition processes contribute to the growth of drilling performance and consist of changing the following: bit design for specific rocks; drilling method; drilling mode; boring rig design; controlled parameters of drilling process and rock properties redetermination; parameters of maintenance and repair system. Based on the performed analysis, the systematization results of the main factors predetermining the need for transition processes implementation in the “drilling operations” subsystem were obtained and presented. The proposed approach allowed to reveal a holistic picture of the main interacting factors in the “drilling operations” subsystem. Based on the factors systematization presented in the article it is possible to envisage changes of individual factors depending on changes of other factors, not functionally related directly when planning drilling operations.

scholarly journals Study of High-Speed Mechanical Micro Drilling Process Fundamentals for Small Holes

2020 ◽  
Vol 1575 ◽  
pp. 012179
Author(s):  
Yang Li ◽  
Xiang Cheng ◽  
Siying Ling ◽  
Guangming Zheng ◽  
Hisham Manea
Keyword(s):  
High Speed ◽  
Drilling Process ◽  
Micro Drilling ◽  
Small Holes

The Effect of Spindle Speed and Feed Rate on Hole Diameter of High-Speed Micro-Drilling for Micro-Screen Manufacture

2020 ◽  
Vol 402 ◽  
pp. 125-130
Author(s):  
Muhammad Tadjuddin ◽  
Suhaeri ◽  
Muhammad Dirhamsyah ◽  
Aulia Udink ◽  
Fatur Rahmatsyah
Keyword(s):  
Feed Rate ◽  
High Speed ◽  
Tool Material ◽  
Spindle Speed ◽  
Machining Process ◽  
Drilling Process ◽  
Machining Parameters ◽  
A Value ◽  
Micro Drilling ◽  
Hole Dimensions

The micro-drill is one of the manufacturing processes that is developing, especially in the electronics, aerospace, pharmaceutical, and automotive industries. This paper describes the results of the high-speed microdrill process in stainless steel. The drilling process is used to make the micro screen. The cutting tool material is tungsten carbide with a diameter of 0.2 mm. Drilling holes arranged in a honeycomb configuration. The machining parameters used are spindle speed of 20,000 rpm, 22,000 rpm, 24,000 rpm, and feed rate of 1 mm/min, 1.5 mm/min, 2 mm/min. Micro-drilling holes are visually analyzed using a Scanning Electron Microscope (SEM) to measure the accuracy of the hole dimensions. The results of the machining process found that the most significant deviation of the hole dimension size with a value of 0.276 mm occurred at a spindle speed of 20,000 rpm with a feed of 1 mm/min. While the deviation of the smallest hole size with a value of 0.2019 mm occurred at a spindle speed of 24,000 rpm with a feed of 2 mm/min, these results conclude that the accuracy of the hole dimensions will increase in proportion to the increase in spindle speed and feeding.

Process Design and Control Method of Laser Via Hole Drilling of Printed Wiring Boards Based on High Speed Camera Monitor

2017 ◽  
Author(s):  
Koji Kanki ◽  
Toshiki Hirogaki ◽  
Eiichi Aoyama ◽  
Keiji Ogawa
Keyword(s):  
High Speed ◽  
Copper Foil ◽  
Control Method ◽  
Irradiation Time ◽  
Hole Drilling ◽  
Drilling Process ◽  
High Speed Camera ◽  
Printed Wiring Boards ◽  
Laser Method ◽  
Direct Laser

In recent years, the performance and miniaturization of portable information devices have rapidly advanced. The build-up process is often used in the manufacturing of printed wiring boards (PWBs) for high-density circuits. At present, CO2 laser beams are generally used in the build-up process to drill blind via holes (BVHs) that connect copper foils. The Cu direct-laser method is often used in this process, which irradiates laser to drill the copper foil and insulation layer simultaneously. Cu direct-laser involves a complex phenomenon because it drills copper and resin, with different decomposition points, at the same time. However, only few studies have been made in this field. This report focuses on monitoring Cu direct-laser drilling with a high-speed camera. We drilled holes with four different laser power outputs, 25 W, 50 W, 75 W, and 95 W and measured the size of the drilled holes. During the drilling process, the camera captured the emission of scattering materials in the PWBs. We have processed the images obtained from the camera to observe the scattering material. As a result, we found out that changes in the amount of scattering occur on four occasions: when the outer copper foil is drilled through, when the drilled depth reaches the inner copper foil, when the increase rate of the hole diameter is reduced, and when the inner copper foil is drilled through. Based on these results, the suitable laser irradiation time can be determined for different drilling conditions.

Effect of Diamond Coating on Drilling Force and Temperature during High Speed Micro Drilling of Bone

2016 ◽  
Vol 1136 ◽  
pp. 239-244
Author(s):  
Zi Han Zhao ◽  
Liang Wen ◽  
Jin Bang Song ◽  
De Dong Yu ◽  
Ming Chen ◽  
...  
Keyword(s):  
High Speed ◽  
Drilling Process ◽  
Diamond Coating ◽  
Bone Drilling ◽  
Drilling Force ◽  
Drilling Temperature ◽  
High Speed Drilling ◽  
Development Direction ◽  
Micro Drilling ◽  
Huge Impact

Bone drilling commonly exists in clinical practice and the heat and force generated by the drilling process has a huge impact on the surgery effect and the recovery of patients. High speed drilling, proved to have less injury and be more efficient when compared to the traditional low speed drilling, is considered to be the development direction of bone drilling-related surgeries. In order to make a further study of the controlling of the heat and force during the bone drilling process, the experiment designed to examine the influence of the diamond coating has been conducted and the result indicates that the diamond coating generally has little influence on the drilling force, however, it can increase the drilling temperature to a certain extent which indicates that the diamond coating is not suitable to apply to bone drills under the conditions of the conducted experiments. The result of this research could be of some help to the development of new kinds of medical drills.

Characteristics of Spatter in Micro-Drilling of Metal Sheet by Pulsed Nd:YAG Laser

2016 ◽  
Vol 10 (6) ◽  
pp. 874-881 ◽  
Author(s):  
Yasuhiro Okamoto ◽  
◽  
Hibiki Yamamoto ◽  
Akira Okada ◽  
Keyword(s):  
Initial Velocity ◽  
High Speed ◽  
Gas Flow ◽  
Thermal Damage ◽  
Drilling Process ◽  
3D Tracking ◽  
Workpiece Surface ◽  
Video Cameras ◽  
High Speed Video ◽  
Micro Drilling

In laser cutting and drilling process, molten material was scattered as spatter, which deteriorates the surface integrity of a workpiece because of the thermal damage. It is expected that the control of assist gas flow can reduce the adhesion of spatter. In order to investigate the improvement method of thermal damage due to the adhesion of spatter, it is required to clarify characteristics of spatter. Therefore, a method was developed to collect and analyze spatter based on the use of high-speed video cameras in the laser micro-drilling process, and the characteristics of spatter movement were numerically investigated by CFD analysis. The scattering velocity and angle of the spatter were investigated by recognizing and tracking spatter with the high-speed video observation. The movement of spatter was observed by using two high-speed video cameras, and analyzed by using a two-direction tracking method, in which the 3D tracking lines of spatter particles were reconstructed in the forward and backward frames, and the actual trajectory of individual spatter particle was obtained by averaging those tracking lines. These measurements revealed that the initial velocity of spatter was mainly distributed from 52 m/s to 200 m/s with an average velocity of 129 m/s. The initial angle of spatter was mainly distributed between 0 and 30 degrees from the workpiece surface in the upward direction. There was little correlation between the initial velocity and angle of spatter. The diameter of spatter was mainly distributed from 1μm to 4μm with an average diameter of 3.7μm. It is important to use the processing conditions achieving the smaller spatter diameter in order to reduce the thermal damage caused by spatter. Although coaxial assist gas flow has an influence on the spatter behavior, that time period is very short. Therefore, it is important to control the spatter behavior outside of the coaxial assist gas flow by using an additional gas flow to prevent the thermal damage to the workpiece surface.

Sign in / Sign up

Export Citation Format

Share Document