A Parameters Optimization of the CO2 Laser Drilling Process for HDI Microvia Fabrication

2012 ◽  
Vol 214 ◽  
pp. 451-454 ◽  
Author(s):  
You Zuo Hu ◽  
Wei He ◽  
Wei Dong Xue ◽  
Zhi Hua Tao ◽  
Yu Xing Huang ◽  
...  
Keyword(s):  
Pulse Width ◽  
Printed Circuit Boards ◽  
Laser Energy ◽  
Experimental Parameter ◽  
Laser Drilling ◽  
Parameters Optimization ◽  
Laser Source ◽  
Drilling Process ◽  
Beam Diameter ◽  
Via Holes

The blind via holes formation by laser drilling is one of the key technologies for demanding high density interconnect printed circuit boards. In this paper , the drilling conditions of drilling the blind via holes and the quality of the drilled holes are examined using a CO2 laser source against the FR4 board without copper foil.We chose laser energy,pulse shot,pulse width and diameter of beam as the experimental parameter . The results showed that laser energy and beam diameter played a more important role on changing the blind vias’ diameter than pulse shot and pulse width .While the pulse shot and pulse width take more important role in changing the depth of vias.

Experimental and Parametric Evaluation of Quality Characteristics in Nd:YAG Laser Micro-Drilling of Ti6Al4V and AISI 316

2017 ◽  
Author(s):  
Suman Chatterjee ◽  
Siba Sankar Mahapatra ◽  
Anshuman Kumar Sahu ◽  
Vijay K. Bhardwaj ◽  
Ambar Choubey ◽  
...  
Keyword(s):  
Heat Affected Zone ◽  
Repetition Rate ◽  
Pulse Repetition Rate ◽  
Pulse Width ◽  
Laser Energy ◽  
Laser Drilling ◽  
Pulse Repetition ◽  
Drilling Process ◽  
Maximum Information ◽  
Aisi 316

Titanium alloy of grade-5 (Ti6Al4V) and stainless steel of grade AISI 316 have wide applications in various engineering sectors due to their favorable material properties such as low thermal conductivity, high corrosion resistance and high strength to weight ratio. The literature survey suggests that Ti6Al4V and AISI 316 have the similar field of applications and comparative study of both the materials was limited. In the present study, laser drilling of Ti6Al4V and AISI 316 have been performed using Nd:YAG millisecond laser under identical machining conditions. The control parameters considered for the study are laser energy, pulse repetition rate, pulse width and flushing pressure having each at three different levels. To reduce the total number of experimental run and obtain maximum information for the experimental trials, Taguchi’s L27 orthogonal array has been adopted. Further, the study has been focused to understand the behavior based on experimental data on similarities and differences between laser drilling process of Ti6Al4V and AISI 316 are qualitative. The outcome of experiments in terms of circularity of hole and heat affected zone (HAZ) for laser drilled holes are studied. It is observed that HAZ increases with increase in laser energy and pulse repetition rate. It may be due to a higher average power of the laser beam, which is directly proportional to laser energy and pulse repetition rate. Higher the value of laser energy, higher will be the laser thermal energy and higher HAZ. Heat affected zone (HAZ) can be minimized with low laser energy and pulse width during laser drilling of Ti6Al4V and AISI 316. From the study, it is revealed that pulse repetition rate is the most significant parameter in the formation of circularity and HAZ.

Cu-Direct Laser Drilling of Blind Via-Hole in Multi-Layer PWBs: Process Visualization Using High-Speed Camera Images

2012 ◽  
Vol 516 ◽  
pp. 30-35 ◽  
Author(s):  
Kuniyoshi Obata ◽  
Toshiki Hirogaki ◽  
Eiichi Aoyama ◽  
Keiji Ogawa
Keyword(s):  
High Speed ◽  
Substrate Surface ◽  
Laser Drilling ◽  
Drilling Process ◽  
Positional Accuracy ◽  
Board Density ◽  
Process Visualization ◽  
Direct Laser ◽  
Via Holes ◽  
Direct Drilling

Electrical circuits of Printed Wiring Boards (PWBs) have become multi-layered. Therefore, the formation of micro-blind holes for interlayer electrical connections (blind via holes: BVH) is required. As a result, Cu-direct laser drilling is attracting attention. However, Cu-direct drilling is problematic in that it produces a copper overhang as a result of copper and resin, which have different decomposition points, being melted simultaneously. In addition, the state of PWB surface after the laser drilling is very important. However, this procedure restricts the board density that can be achieved as a result of the limited positional accuracy of the etching process. Consequently, using a Cu-direct drilling process, which does not require etching of the copper foil, to drill BVHs to connect copper foils using a CO2 laser beam has been receiving considerable attention for the next-generation high density PWB manufacturing. However, in the Cu process of generating a direct and overhang problem, there is the problem of accuracy on the substrate surface. In contrast, in-depth research on quality companies has not been performed. Thus, we observe the removal process. Furthermore, we demonstrated reduced overhang.

A Coupled Stagnation Flow and Knudsen Layer Analysis for Laser Drilling

1999 ◽  
Author(s):  
John J. Batteh ◽  
Michael M. Chen ◽  
Jyoti Mazumder
Keyword(s):  
Laser Energy ◽  
Flow Analysis ◽  
Laser Drilling ◽  
Knudsen Layer ◽  
Beam Radius ◽  
Drilling Process ◽  
Stagnation Flow ◽  
Recoil Pressure ◽  
Layer Analysis ◽  
Combined Action

Abstract The application of lasers in industrial drilling processes is rapidly increasing. Consequently there is a great need to understand the fundamental physics of the laser drilling process. Recent experiments have shown that material removal occurs via the combined action of vaporization and melt expulsion due to the vaporization-induced recoil pressure. The authors (Batteh et al., 1998) developed a quasi-steady stagnation flow analysis to study the physical mechanisms of laser drilling by examining the heat transfer and fluid flow in the molten metal. This paper presents an extension of that analysis by including the effects of nonequilibrium vaporization. A Knudsen layer analysis is used to model the nonequilibrium evaporation at the liquid-vapor interface and the compressible flow outside the Knudsen layer. The analysis gives the pressure, temperature, and density jumps across the Knudsen layer. Numerical results for the combined stagnation flow and Knudsen layer analysis are shown for several different materials over a range of laser intensities commonly used in laser drilling. Drilling trends are shown as functions of the laser energy and beam radius. The results show that a significant portion of the material removed occurs through melt expulsion due to the vaporization-induced recoil pressure. The results from both the equilibrium and Knudsen layer models for vaporization are compared, and the validity of equilibrium vaporization models are discussed.

scholarly journals Employment of Some Parameters to Enhance Laser-Drilling of Aluminum

2005 ◽  
Vol 10 ◽  
pp. 93
Author(s):  
Oday A. Hamadi
Keyword(s):  
Electric Field ◽  
Nd:Yag Laser ◽  
Laser Energy ◽  
Low Pressure ◽  
Laser Drilling ◽  
Sample Temperature ◽  
Drilling Process ◽  
Pulsed Nd:Yag Laser ◽  
Hole Depth

In this work, some parameters affecting drilling of aluminum samples by a pulsed Nd:YAG laser were studied. These parameters are multi-pulses irradiation, controlling sample temperature, low-pressure ambient and application of electric field on the sample. Results presented in this work explained that these parameters can enhance drilling process throughout increasing hole depth in aluminum samples at the same laser energy used for irradiation. 

Relevant Geometric Features in the Percussion Laser Microdrilling of Different Alloys

Volume 3 ◽  
2004 ◽  
Author(s):  
Paola Bassani ◽  
Edoardo Capello ◽  
Enrico Gallus ◽  
Elisabetta Gariboldi ◽  
Luca Longoni ◽  
...  
Keyword(s):  
Process Parameters ◽  
Pulse Energy ◽  
Pulse Length ◽  
Pulse Frequency ◽  
Laser Drilling ◽  
Laser Source ◽  
Drilling Process ◽  
Geometric Features ◽  
Hole Shape ◽  
Laser Sources

In the recent decade the laser drilling process has continually attracted new interests and has found increasing applications in the industry. Nowadays the most common industrial laser sources for laser drilling are the solid state ones with pulse length of the order of milliseconds, even if nanosecond and femtosecond pulse sources can also be found in industrial applications. The latter, short and ultrashort laser sources, are very promising since they are expected to generate the hole directly by vaporisation, leaving the hole surfaces free of molten and resolified layer, as well as very low amount of spatter. This paper reports an experimental study on microhole laser machining and on influence of some process parameters on the hole shape. The laser source used in the study was a pulsed, diode pumped, Q-switched Nd:YAG laser. The materials investigated were four different alloys (AISI 304 stainless steel, cp titanium, CuZn35 brass and IN718 alloy), provided as 0.5 mm thick commercial sheets. Since an experimental approach has been here preferred, the performed experimental plan has been designed by the analysis of variance technique. The influence of material type, as well as laser process parameters, like pulse frequency and pulse energy, have been investigated. Relevant geometrical features, like top and bottom hole diameter, taper angle, top and bottom aspect ratio, have been measured and analysed. Moreover, the geometric features of the top spatter as well as the metallurgical characteristics of heat affected zone has been investigated. The results have shown that pulse energy strongly affects both geometric and metallurgical hole features. On the other hand, pulse frequency does not seem to influence the hole shape in all material. The presence of spatter and metallographic analysis confirmed the production of molten layers in all material mainly around the hole entrance.

Study on Features of 532nm Laser as Laser Source of Lidar

2016 ◽  
Vol 851 ◽  
pp. 544-549
Author(s):  
Peng Zhang ◽  
Ming Ming Xi ◽  
Manman Wang ◽  
Pu Liu ◽  
Tao Liu ◽  
...  
Keyword(s):  
Experimental Data ◽  
Pulse Width ◽  
Laser Energy ◽  
Laser System ◽  
Frequency Doubling ◽  
Laser Cavity ◽  
Laser Source ◽  
Frequency Multiplication ◽  
Ktp Crystal ◽  
Solid Laser

The laser source of Lidar usually use the high power solid laser, the performance of Lidar depend on the laser features, so that to study the laser features is contribute to optimize the performance of Lidar. Set up and design a pulse solid laser of Nd3+:YAG as the working substance. Through adopt the KTP crystal frequency multiplication technology outside the laser cavity and electro-optic q-switch technique, the maximum dynamic pulse energy of 155mJ and pulse width of 9.6 ns with the 532nm laser is generated. Using the oscilloscope, photoelectric pulse sensor and laser energy meter to measurement the experimental data of the laser source features Through analyze and discuss the experimental data, the relationship between the pulse width, the static and dynamic ratio, the peak power of the pulse Nd3+:YAG laser, the frequency doubling efficiency of the KTP crystal and the input power of laser are given, the solid laser system and the experimental data can provide a basic equipment and reference data to the further study.

scholarly journals Effects of Beam Size and Pulse Duration on the Laser Drilling Process

2016 ◽  
Author(s):  
Nazia Afrin ◽  
Pengfei Ji ◽  
J. K. Chen ◽  
Yuwen Zhang
Keyword(s):  
Laser Beam ◽  
Pulse Duration ◽  
Material Removal ◽  
Convection Heat Transfer ◽  
Laser Drilling ◽  
Drilling Process ◽  
Beam Diameter ◽  
Beam Size ◽  
Laser Beam Diameter ◽  
Ablation Efficiency

A two-dimensional axisymmetric transient laser drilling model is used to analyze the effects of laser beam diameter and laser pulse duration on the laser drilling process. The model includes conduction and convection heat transfer, melting, solidification and vaporization, as well as material removal resulting from the vaporization and melt ejection. The validated model is applied to study the effects of laser beam size and pulse duration on the geometry of the drilled hole. It is found that the ablation effect decrease with the increasing beam diameter due to the effect of increased vaporization rate, and deeper hole is observed for the larger pulse width due to the higher thermal ablation efficiency.

scholarly journals Analysis and optimization of laser drilling process during machining of AISI 303 material using grey relational analysis approach

2021 ◽  
Vol 3 (3) ◽  
Author(s):  
V. Chengal Reddy ◽  
Thota Keerthi ◽  
T. Nishkala ◽  
G. Maruthi Prasad Yadav
Keyword(s):  
Surface Roughness ◽  
Process Parameters ◽  
Grey Relational Analysis ◽  
Pulse Frequency ◽  
Laser Drilling ◽  
Simultaneous Optimization ◽  
Fibre Laser ◽  
Drilling Process ◽  
Relational Analysis ◽  
Grey Relational

AbstractSurface roughness and heat-affected zone (HAZ) are the important features which influence the performance of the laser-drilled products. Understanding the influence of laser process parameters on these responses and identifying the cutting conditions for simultaneous optimization of these responses are a primary requirement in order to improve the laser drilling performance. Nevertheless, no such contribution has been made in the literature during laser drilling of AISI 303 material. The aim of the present work is to optimize the surface roughness (Ra) and HAZ in fibre laser drilling of AISI 303 material using Taguchi-based grey relational analysis (GRA). From the GRA methodology, the recommended optimum combination of process parameters is flushing pressure at 30 Pa, laser power at 2000 W and pulse frequency at 1500 Hz for simultaneous optimization of Ra and HAZ, respectively. From analysis of variance, the pulse frequency is identified as the most influenced process parameters on laser drilling process performance.

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