Influence of Cu Surface Treatment on the Cu-Direct Via Hole Drilling Efficiency of PWBs

2007 ◽  
Author(s):  
Toshiki Hirogaki ◽  
Eiichi Aoyama ◽  
Keiji Ogawa ◽  
Shogo Matsutani
Keyword(s):  
Laser Beam ◽  
Surface Treatment ◽  
Co2 Laser ◽  
Copper Foil ◽  
Copper Surface ◽  
Surface Shape ◽  
Hole Drilling ◽  
Black Oxide ◽  
Direct Drilling ◽  
The Relationship

This report describes the quality assessment of blind via holes (BVHs) of Printed Wiring Boards (PWBs) drilled by a CO2 laser using Cu-direct drilling. In the Cu-direct drilling method, the copper foil and the buildup layer are melted at the same time, and the surface is treated to increase the laser energy absorbed by the copper foil because an untreated copper surface reflects most of the 10.6-μm-wavelength CO2 laser beam. We used black-oxide and V-bond treatments as surface treatment. Previously, the only black-oxide treatment was paid attention to, but the new V-bond treatment is also investigated in this report. First, a straightforward method employing infrared thermography was proposed to determine the absorbance of the CO2 laser beam by the copper surface. Then, we used SEM to characterize the copper surfaces after surface treatment, and established the relationship between laser absorbance and surface shape. Subsequently, we observed the circumference of a point irradiated with the CO2 laser and explained melting processes were different from surface shape. Finally, we investigated the relationship between laser absorbance and BVH quality, and showed that a high absorbance improved BVH quality.

Cu-Direct Laser Drilling of Blind Via-Hole in Multi-Layer PWBs: Influence of Surface Treatment on Drilled Hole Quality

2009 ◽  
Author(s):  
Toshiki Hirogaki ◽  
Eiichi Aoyama ◽  
Keiji Ogawa ◽  
Tsukasa Ayuzawa
Keyword(s):  
Surface Treatment ◽  
Co2 Laser ◽  
Copper Foil ◽  
Laser Energy ◽  
Copper Surface ◽  
Laser Drilling ◽  
Hole Quality ◽  
Direct Laser ◽  
Overhang Length ◽  
Direct Drilling

This report describes the quality assessment of Blind Via Holes (BVHs) of Printed Wiring Boards (PWBs) drilled by a CO2 laser using Cu-direct drilling. In the Cu-direct drilling method, the copper foil and the build-up layer are melted at the same time, and the surface is treated to increase the laser energy absorbed by the copper foil since an untreated copper surface reflects most of the 10.6-μm-wavelength CO2 laser beam. However, there are few reports dealing with Cu-direct laser drilling of PWBs. In addition, when copper and resin with different processing thresholds are drilled at the same time, occurrences of a defect called overhang have been observed. So, in this report, first we propose a new method using thermography to measure the absorptance of a PWB surface for a CO2 laser. Moreover, we investigate how surface treatment of the outer copper foil influences the quality of a laser-drilled hole. Then, we observe the circumference of a point irradiated with the CO2 laser and explain how melting processes are different from surface treatment. Finally, based on the research we establish a method in order to cut down the overhang length as a parameter of drilled-hole quality. We also show that a high absorptance improves BVH quality.

Cu-Direct Via-Hole Drilling of Aramid Fiber Reinforced Build-Up Layer by CO2 Laser Beam

2005 ◽  
Author(s):  
Eiichi Aoyama ◽  
Toshiki Hirogaki ◽  
Keiji Ogawa ◽  
Nobuyuki Doi ◽  
Ryu Minagi
Keyword(s):  
Co2 Laser ◽  
Copper Foil ◽  
Effective Means ◽  
Hole Diameter ◽  
Hole Drilling ◽  
Printed Wiring Boards ◽  
Laser Absorption ◽  
Direct Laser ◽  
Via Hole ◽  
The Difference

This report describes the features of Cu-direct laser drilled hole quality on multi-layer Printed Wiring Boards (PWBs). Cu-direct laser drilling drills the outer copper foil and build-up layer at the same time, which makes it difficult to form a blind via hole (BVH) with high quality because the copper foil has high reflection coefficient for a CO2 laser with wavelength 10.6 μm. Therefore, this study focused on improving drilled hole qualities such as diameter and overhang. First, the influence of laser irradiation conditions on forming BVH and the drilled hole diameter were investigated in detail. Second, a new method employing thermography was proposed in order to evaluate the absorption of copper foil after surface treatment. Third, the effect of mixing fillers into the build-up layer in order to reduce the amount of overhang was shown to be effective both experimentally and theoretically. As a result, it is clear that decreasing the difference in the laser absorption rate of the outer copper foil is an effective means to control the hole diameter and reducing the heat characteristic difference between the outer copper foil and the build-up layer can effectively decrease overhang.

scholarly journals Control of TIG Arc with Scanning CO2 Laser Beam. Study on High Speed Surface Treatment by Arc with Laser. (3rd Report).

2000 ◽  
Vol 18 (4) ◽  
pp. 534-539 ◽  
Author(s):  
Akihiro UTSUMI ◽  
Jun MATSUDA ◽  
Masafumi YONEDA ◽  
Munehide KATSUMURA
Keyword(s):  
Laser Beam ◽  
Surface Treatment ◽  
Co2 Laser ◽  
High Speed

scholarly journals Hole Drilling in Polymethyl Methacrylate (PMMA) Using CO2 Laser

2014 ◽  
Vol 7 (1) ◽  
pp. 30-39
Author(s):  
Rana M. Taha
Keyword(s):  
Laser Beam ◽  
Polymethyl Methacrylate ◽  
Co2 Laser ◽  
Exposure Time ◽  
Laser Annealing ◽  
Hole Drilling ◽  
Work Piece ◽  
Drilling Tool ◽  
Hole Depth ◽  
Penetration Velocity

Laser sources are used in a large variety of applications for material processing. It is mainly used for welding, cutting, drilling, laser annealing, etc. This study narrows the scope down to one of the process, namely, laser drilling.The hole depth, width and penetration velocity of evaporation depend on different parameters such as power, material, exposure time, distance between drilling tool and the material, the drilling tool, etc. In this paper; the laser beam was used as drilling tool. 16W CO2 laser (10.6μm) and transparent Perspex (PMMA) which is the abbreviation of polymethyl methacrylate work piece with 8mm thickness were used. The distance between laser beam and the material was 5cm. Different powers for CO2 laser were used for different exposure time. Hole depth, time required for boiling, heat flow per unit area and penetration velocity of evaporation were calculated. Measured and calculated results were approximately the same. Many figures which representing the relations between laser power, time to reach boiling, hole width, hole depth and exposure time were obtained by using Matlab 2008 software program

Mechanical properties and fatigue behavior of CO2 laser beam welded armor steel joints

2020 ◽  
Vol 62 (7) ◽  
pp. 689-697
Author(s):  
Zulkuf Balalan ◽  
Furkan Sarsilmaz ◽  
Omer Ekinci
Keyword(s):  
Mechanical Properties ◽  
Laser Beam ◽  
Co2 Laser ◽  
Fatigue Behavior ◽  
Armor Steel ◽  
Steel Joints

scholarly journals Analyzing the Effects of the Kinematic System on the Quality of Holes Drilled in 42CrMo4 + QT Steel

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4046
Author(s):  
Mateusz Bronis ◽  
Edward Miko ◽  
Lukasz Nowakowski
Keyword(s):  
Cutting Speed ◽  
Hole Drilling ◽  
Internal Cooling ◽  
Hole Quality ◽  
The Third ◽  
Kinematic System ◽  
Turning Center ◽  
Dimensional Errors ◽  
The Relationship

This article discusses the relationship between the kinematic system used in drilling and the quality of through-holes. The drilling was done on a CTX Alpha 500 universal turning center using a TiAlN-coated 6.0 mm drill bit with internal cooling, mounted in a driven tool holder. The holes were cut in cylindrical 42CrMo4 + QT steel samples measuring 30 mm in diameter and 30 mm in length. Three types of hole-drilling kinematic systems were considered. The first consisted of a fixed workpiece and a tool performing rotary (primary) and linear motions. In the second system, the workpiece rotated (primary motion) while the tool moved linearly. In the third system, the workpiece and the tool rotated in opposite directions; the tool also moved linearly. The analysis was carried out for four output parameters characterizing the hole quality (i.e., cylindricity, straightness, roundness, and diameter errors). The experiment was designed using the Taguchi approach (orthogonal array). ANOVA multi-factor statistical analysis was used to determine the influence of the input parameters (cutting speed, feed per revolution and type of kinematic system) on the geometrical and dimensional errors of the hole. From the analysis, it is evident that the kinematic system had a significant effect on the hole roundness error.

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