Advanced metrology of Laser Groove Buried Contact processing for silicon CPV

2012 ◽  
Vol 1447 ◽  
Author(s):  
B Maniscalco ◽  
P M Kaminski ◽  
K Bass ◽  
A Abbas ◽  
G West ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Laser Power ◽  
Screen Printing ◽  
Crystalline Silicon ◽  
Focal Length ◽  
Surface Metrology ◽  
Ablation Process ◽  
Power Pulse ◽  
Laser Ablation Process ◽  
Contact Processing

ABSTRACTThe solar cells employed in low to medium (50 to 200 suns) concentration photovoltaic (CPV) are usually mono-crystalline silicon. Laser Groove Buried Contacts (LGBC) are preferred to screen printing in these cells due to the high currents generated in the system. In this paper, we report on the use of Coherence Correlation Interferometry (CCI) to accurately measure the width and depth of the laser-ablated grooves. In addition, the technique is also used to measure the surface roughness at the bottom of the trenches, since this can determine the success of the subsequent plating process, and at the top surface to optimize the debris control and obtain clean surfaces and well-shaped groove edges. The laser ablation process was also optimized to obtain the groove aspect ratio and surface quality required. Process parameters to be controlled include laser power, pulse energy, stage speed and focal length. The CCI technique is capable of providing all the groove and surface metrology required for this process optimization.

Modeling of Cut Depth and Surface Analyses of Silicon Wafer in Laser Micromachining Process

2016 ◽  
Vol 835 ◽  
pp. 242-247
Author(s):  
Seksit Mekloy ◽  
Viboon Tangwarodomnukun ◽  
Chaiya Dumkum
Keyword(s):  
Laser Ablation ◽  
Surface Morphology ◽  
Laser Power ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Surface Characteristics ◽  
Substrate Material ◽  
Ablation Process ◽  
Laser Ablation Process ◽  
Cut Depth

Silicon has widely been used as a substrate material in various microfabrication processes. Cut depth and surface morphology of silicon obtained from laser ablation process have to be well controlled to achieve the required features of micro-components being made. Though laser power has been known as a major factor affecting these responses, the detailed investigations of this factor on cut geometries and surface quality have still been deficiency. In this research, the cut geometries and surface characteristics of silicon induced by a pulse laser were experimentally investigated. The increase in laser power not only increased the cut dimensions, but also increased the debris deposition on and inside the cut channel. Furthermore, an analytical model was developed in this study to predict the cut depth of silicon in pulsed laser ablation, and an agreement between the prediction and experiment was also demonstrated.

Comparison of the laser ablation process on Zn and Ti using pulsed digital holographic interferometry

2010 ◽  
Vol 256 (14) ◽  
pp. 4633-4641 ◽  
Author(s):  
E. Amer ◽  
P. Gren ◽  
A.F.H. Kaplan ◽  
M. Sjödahl ◽  
M. El Shaer
Keyword(s):  
Laser Ablation ◽  
Holographic Interferometry ◽  
Ablation Process ◽  
Laser Ablation Process

The mechanism of process parameters influencing the AlSi10Mg side surface quality fabricated via laser powder bed fusion

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Shimin Dai ◽  
Hailong Liao ◽  
Haihong Zhu ◽  
Xiaoyan Zeng
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Process Parameters ◽  
Laser Power ◽  
Side Surface ◽  
Laser Powder Bed Fusion ◽  
Scanning Velocity ◽  
Content Type ◽  
Powder Bed

Purpose For the laser powder bed fusion (L-PBF) technology, the side surface quality is essentially important for industrial applicated parts, such as the inner flow parts. Contour is generally adopted at the parts’ outline to enhance the side surface quality. However, the side surface roughness (Ra) is still larger than 10 microns even with contour in previous studies. The purpose of this paper is to study the influence of contour process parameters, laser power and scanning velocity on the side surface quality of the AlSi10Mg sample. Design/methodology/approach Using L-PBF technology to manufacture AlSi10Mg samples under different contour process parameters, use a laser confocal microscope to capture the surface information of the samples, and obtain the surface roughness Ra and the maximum surface height Rz of each sample after analysis and processing. Findings The results show that the side surface roughness decreases with the increase of the laser power at the fixed scanning velocity of 1,000 mm/s, the side surface roughness Ra stays within the error range as the contour velocity increases. It is found that the Ra increases with the scanning velocity increasing and the greater the laser power with the greater Ra increases when the laser power of contour process parameters is 300 W, 350 W and 400 W. The Rz maintain growth with the contour scanning velocity increasing at constant laser power. The continuous uniform contour covers the pores in the molten pool of the sample edge and thus increase the density of the sample. Two mechanisms named “Active adhesion” and “Passive adhesion” cause sticky powder. Originality/value Formation of a uniform and even contour track is key to obtain the good side surface quality. The side surface quality is determined by the uniformity and stability of the contour track when the layer thickness is fixed. These research results can provide helpful guidance to improve the surface quality of L-PBF manufactured parts.

scholarly journals Micropatterning on Biodegradable Nanofiber Scaffolds by Femtosecond Laser Ablation Process

2016 ◽  
Vol 49 (6) ◽  
pp. 555-559
Author(s):  
Yongwoo Chung ◽  
Indong Jun ◽  
Yu-Chan Kim ◽  
Hyun-Kwang Seok ◽  
Seok Chung ◽  
...  
Keyword(s):  
Laser Ablation ◽  
Femtosecond Laser ◽  
Femtosecond Laser Ablation ◽  
Ablation Process ◽  
Laser Ablation Process ◽  
Nanofiber Scaffolds

Analysis of Roughness and Heat Affected Zone of Steel Plates Obtained by Laser Cutting

2014 ◽  
Vol 974 ◽  
pp. 169-173 ◽  
Author(s):  
Imed Miraoui ◽  
Mohamed Boujelbene ◽  
Emin Bayraktar
Keyword(s):  
Surface Roughness ◽  
Laser Beam ◽  
Heat Affected Zone ◽  
Laser Power ◽  
Laser Cutting ◽  
Major Effect ◽  
Steel Plates ◽  
Beam Diameter ◽  
Laser Beam Diameter ◽  
Cut Surface

In the present study, high-power CO2 laser cutting of steel plates has been investigated and the effect of the input laser cutting parameters on the cut surface quality is analyzed. The average roughness of the cut surface of the specimens, produced by different laser beam diameter and laser power, were measured by using roughness tester. The scanning electron microscopy SEM is used to record possible metallurgical alterations on the cut edge. The aim of this work is to investigate the effect of laser beam diameter and laser power on the cut surface roughness and on the heat affected zone width HAZ of steel plates obtained by CO2 laser cutting. An overall optimization was applied to find out the optimal cutting setting that would improve the cut surface quality. It was found that laser beam diameter has a negligible effect on surface roughness but laser power had major effect on roughness. The cut surface roughness decreases as laser power increases. Improved surface roughness can be obtained at higher laser power. Also, laser beam diameter and laser power had major effect on HAZ width. It increases as laser power increases.

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