Experimental Research on Microburrs of High Speed Drilling of PCB Using Microdrill

2012 ◽  
Vol 497 ◽  
pp. 215-219 ◽  
Author(s):  
Xiao Hu Zheng ◽  
Zhi Qiang Liu ◽  
Cheng Yong Wang ◽  
Qing Long An ◽  
Ming Chen
Keyword(s):  
High Speed ◽  
Copper Foil ◽  
Great Influence ◽  
Burr Formation ◽  
Drilling Process ◽  
Fiber Plastic ◽  
High Speed Drilling ◽  
Micro Hole ◽  
Three Stages ◽  
Exit Burr

Microburrs have great influence on printed circuit board’s quality. PCB is composed of glass fiber plastic reinforcement material and copper foil. The PCB microburrs are generated in copper foil drilling process. These burrs are generated by copper extrusion and accumulation around the micro-hole. Enter burr and exit burr is quite different. Enter burrs are lower than exit burrs. The burr formation experienced three stages: First, Copper foil extrudes with the feed of microdrill; Second, Most of the Materials are cut off by drill tip and the rest of material; At last, rollover burrs appear when drill enters or exits uncut chip rolls.

Dynamic characteristics of a drill in the drilling process

2003 ◽  
Vol 217 (2) ◽  
pp. 161-167 ◽  
Author(s):  
B W Huang
Keyword(s):  
Dynamic Characteristics ◽  
High Speed ◽  
Thrust Force ◽  
Time Dependent ◽  
Drilling Process ◽  
Improve Quality ◽  
Vibration Model ◽  
High Speed Drilling ◽  
Spinning Speed ◽  
Twisted Beam

The dynamic characteristics of high-speed drilling were investigated in this study. To improve quality and produce a higher production rate, the dynamic characteristics of the drilling process need to be studied. A pre-twisted beam is used to simulate the drill. The moving Winkler-type elastic foundation is used to approximate the drilling process. A time-dependent vibration model for drilling is presented. The spinning speed, pre-twisted angle and thrust force effects of the drill are considered. The numerical analysis indicates that the natural frequency is suddenly reduced as the drill moves into a workpiece.

scholarly journals Technological Analysis of Turquoise Jewelry (Based on Finds from the Scythian Burial Ground of Ak-Dag I in Tyva)

2019 ◽  
Vol 18 (7) ◽  
pp. 74-86
Author(s):  
Pavel V. Volkov ◽  
Oleg A. Mitko ◽  
Yuliy S. Gubar ◽  
Roman V. Davydov ◽  
Ivan S. Polovnikov
Keyword(s):  
Elemental Composition ◽  
High Speed ◽  
Raw Material ◽  
Burial Ground ◽  
Fine Grained ◽  
Second Stage ◽  
Time Scanning ◽  
High Speed Drilling ◽  
Third Stage ◽  
Three Stages

Purpose. The article presents results of studying the elemental composition and manufacturing technology of turquoise jewelry found in barrow 1 of the Ak-Dag I burial ground of the early Scythian time. Scanning electron microscopy and energy dispersive X-ray spectroscopy were used to determine the elemental composition of the mineral. The presence and ratio of the number of elements in the table indicates that the items are made of turquoise. The basic elements of the mineral include oxides of copper, phosphorus, aluminum and iron. A relatively large amount of iron oxide gives turquoise minerals a more saturated green color. The composition of the samples under study is extremely rich in zirconium, which allows us to identify the field where the raw material was obtained. Results. A traceological study of the artifacts considered was based on the proven methodology of experimental-traceological analysis. As a result of experimental and technological research, we conclude that the process of manufacturing occurred in three stages. Initially, the formation of the main planes of the workpieces and grinding of the ends took place. At the second stage the artifacts were drilled, the starting points of drilling were located at the narrow ends of the items. The traces of work that are visible on the artifacts indicate the use of easel, high-speed drilling. At the third stage the artifacts were processed with a fine-grained abrasive, as a result of which the final products were given a smoothed shape. Conclusion. In general, the production technology of the artifacts considered can be described as relatively perfect. There were closest analogues of the products from the Ak-Dag I site found in the same region. A similar method of inclined drilling was also used by the Scythians of Altai on their stone products.

Dynamic Instability in a High Speed Drilling Process

2005 ◽  
Author(s):  
Bo-Wun Huang ◽  
Jao-Hwa Kuang
Keyword(s):  
High Speed ◽  
Multiple Scales ◽  
Thrust Force ◽  
Dynamic Instability ◽  
Work Piece ◽  
Drilling Process ◽  
Drilling Depth ◽  
High Speed Drilling ◽  
Spinning Speed ◽  
The Galerkin Method

The variation of dynamic instability in a high speed drilling process was investigated in this article. A pre-twisted beam is used to simulate the drill. The time dependent thrust force and drilling depth are considered in the equation of motion. A moving Winkler-Type elastic foundation assumption is employed to the drill tip to approximate the time varying boundary conditions in the drilling process. The Galerkin method is used to formulate the characteristic equation in a discrete form. The variation of instability regions of the drill system is solved and analyzed by employing the multiple scales perturbation method. Numerical results indicate that unstable regions are enlarged and shifted toward a lower frequency suddenly at the moment when the drill attaches the work piece. The effects of spinning speed, pre-twisted angle and thrust force of the drill on the variation of the dynamic instability in a high speed drilling process are also studied.

Study of drilling muds on the anti-erosion property of a fluidic amplifier in directional drilling

2015 ◽  
Author(s):  
Jiang-fu He ◽  
Peng-yu Zhang ◽  
Qi-lei Yin ◽  
Kun Yin ◽  
Hou-ping Liu
Keyword(s):  
Particle Size ◽  
Service Life ◽  
High Speed ◽  
Great Influence ◽  
Life Time ◽  
Solid Content ◽  
Drilling Process ◽  
Jet Velocity ◽  
Drilling Muds ◽  
Erosion Property

Due to some drawbacks of conventional drilling methods and drilling tools, the application of hydraulic hammers with a fluidic amplifier have been extensively popularized since its emergence in recent years. However, the performance life of a fluidic amplifier is still unsatisfactory in oil and gas wells drilling, especially the heavy wear or erosion of the fluidic amplifier leads to the reduction of service life time of hydraulic hammers, which is derived from the incision of drilling muds with high speed and pressure. In order to investigate the influence of drilling muds, such as particle size, solid content and jet velocity, on the antierosion property of a fluidic amplifier, several groups of drilling muds with different performance parameters have been utilized to numerical simulation on basis of Computational Fluid Dynamics (CFD). Simulation results have shown that the jet nozzle of fluidic amplifiers is primarily abraded, afterwards are the lateral plates and the wedge of the fluidic amplifier, which shows extraordinary agreement with the actual cases of fluidic amplifier in drilling process. It can be concluded that particle size, solid content and jet velocity have a great influence on the anti-erosion property of a fluidic amplifier, and the erosion rate linearly varies with the particle size of drilling muds, nevertheless exponentially varies with solid content and jet velocity of drilling muds. As to improve the service life time of a fluidic amplifier, the mud purification system or low solid clay-free mud system is suggested in the operation of directional well drilling.

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.

Finite Element-Based Study of the Mechanics of Microgroove Cutting

2013 ◽  
Vol 135 (3) ◽  
Author(s):  
Keith A. Bourne ◽  
Shiv G. Kapoor ◽  
Richard E. DeVor
Keyword(s):  
Finite Element ◽  
High Speed ◽  
Cutting Tool ◽  
Single Point ◽  
Chip Thickness ◽  
Cutting Process ◽  
Burr Formation ◽  
Process Mechanics ◽  
Exit Burr ◽  
Validation Experiments

In an earlier paper, a high-speed microgroove cutting process that makes use of a flexible single-point cutting tool was presented. In this paper, 3D finite element modeling of this cutting process is used to better understand process mechanics. The development of the model, including parameter estimation and validation, is described. Validation experiments show that on average the model predicts side burr height to within 2.8%, chip curl radius to within 4.1%, and chip thickness to within 25.4%. The model is used to examine chip formation, side burr formation, and exit burr formation. Side burr formation is shown to primarily occur ahead of a tool and is caused by expansion of material compressed after starting to flow around a tool rather than becoming part of a chip. Exit burr formation is shown to occur when a thin membrane of material forms ahead of a tool and splits into two side segments and one bottom segment as the tool exits a workpiece.

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