Laser microwelding of radioactive microcapsules made of high-alloyd steel

2010 ◽  
Author(s):  
I. Avarvarei ◽  
O. Dontu ◽  
D. Besnea ◽  
I. Voiculescu ◽  
R. Ciobanu ◽  
...  
Keyword(s):  
Laser Microwelding

scholarly journals Analysis of Acoustic Emission (AE) Signals for Quality Monitoring of Laser Lap Microwelding

2021 ◽  
Vol 11 (15) ◽  
pp. 7045
Author(s):  
Ming-Chyuan Lu ◽  
Shean-Juinn Chiou ◽  
Bo-Si Kuo ◽  
Ming-Zong Chen
Keyword(s):  
Stainless Steel ◽  
Acoustic Emission ◽  
Frequency Domain ◽  
Monitoring System ◽  
Welding Quality ◽  
Steel Sheets ◽  
Signal Features ◽  
Ae Signal ◽  
Laser Microwelding ◽  
Ae Signals

In this study, the correlation between welding quality and features of acoustic emission (AE) signals collected during laser microwelding of stainless-steel sheets was analyzed. The performance of selected AE features for detecting low joint bonding strength was tested using a developed monitoring system. To obtain the AE signal for analysis and develop the monitoring system, lap welding experiments were conducted on a laser microwelding platform with an attached AE sensor. A gap between the two layers of stainless-steel sheets was simulated using clamp force, a pressing bar, and a thin piece of paper. After the collection of raw signals from the AE sensor, the correlations of welding quality with the time and frequency domain features of the AE signals were analyzed by segmenting the signals into ten 1 ms intervals. After selection of appropriate AE signal features based on a scatter index, a hidden Markov model (HMM) classifier was employed to evaluate the performance of the selected features. Three AE signal features, namely the root mean square (RMS) of the AE signal, gradient of the first 1 ms of AE signals, and 300 kHz frequency feature, were closely related to the quality variation caused by the gap between the two layers of stainless-steel sheets. Classification accuracy of 100% was obtained using the HMM classifier with the gradient of the signal from the first 1 ms interval and with the combination of the 300 kHz frequency domain signal and the RMS of the signal from the first 1 ms interval.

Computational and Experimental Study of Laser Microwelding Processes for Electronic Packaging

2001 ◽  
Author(s):  
Wei Han ◽  
Ryszard J. Pryputniewicz
Keyword(s):  
Experimental Study ◽  
Electronic Packaging ◽  
Thermal Effects ◽  
Resistance Welding ◽  
Alternative Methods ◽  
Number Of Components ◽  
Computational Data ◽  
Computational Methodology ◽  
Laser Microwelding

Abstract Advances in microelectronics depend on reliable packaging. As sizes of components decrease and number of components per package increases, demands on interconnections, or joining, of two parts, e.g., wire to tab, or tab to tab, increase rapidly. Since traditional joining techniques, such as resistance welding, may no longer produce satisfactory microinterconnections, alternative methods are being developed. One of such methods is based on laser microwelding. In this paper, we discuss fundamental processes involved in laser microwelding, outline a computational methodology to simulate thermal effects produced, describe facilities used, present results, and summarize correlations between the experimental and computational data for applications in electronic packaging.

Ultrafast Laser Microwelding

2007 ◽  
Vol 18 (12) ◽  
pp. 46 ◽  
Author(s):  
Takayuki Tamaki ◽  
Wataru Watanabe ◽  
Kazuyoshi Itoh
Keyword(s):  
Ultrafast Laser ◽  
Laser Microwelding
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