Electrical Characteristics Analysis of Bonded Cells for Shingled Modules

2020 ◽  
Vol 20 (11) ◽  
pp. 6653-6658
Author(s):  
Jeong Eun Park ◽  
So Mang Park ◽  
Won Seok Choi ◽  
Jae Joon Jang ◽  
Donggun Lim
Keyword(s):  
Laser Cutting ◽  
High Speed ◽  
Green Laser ◽  
Curing Temperature ◽  
Process Conditions ◽  
Laser Process ◽  
Cut Cell ◽  
Electrically Conductive Adhesive ◽  
Characteristics Analysis ◽  
A Cell

A shingled module fabricated using electrically conductive adhesive (ECA) can increase the light-receiving area and provide greater power than a conventional module fabricated using solder-coated copper ribbons. However, several issues such as damage from laser cutting and poor contact by the conductive paste may arise. In this study, a 15.675 × 3.1 cm2 c-Si cut cell was fabricated using a nanosecond green laser, and cell bonding was performed using ECA to fabricate shingled modules. If the laser process was performed with high speed and low power, there was insufficient depth for cut cell fabrication. This was because the laser only had a thermal effect on the surface. The cell was processed to a depth of approximately 46 μm by the laser, and it could be seen that the laser cutting proceeded smoothly when the laser process affected more than 25% of the wafer thickness. The cut cell was bonded by ECA, and the process conditions were changed. The highest efficiency of 20.27% was obtained for a cell bonded under the conditions of a curing time of 60 s and curing temperature of 150°C. As a result, the efficiency of the bonded cell was increased by approximately 2.67% compared to the efficiency of the conventional cut cell. This was because the shadow loss due to the busbar was reduced, increasing the active area of the module by eliminating the busbar from the illuminated area.

High-speed singulation of electronic packages using a frequency-doubled Nd:YAG laser in a water jet and realization of a 200-W green laser

2003 ◽  
Author(s):  
Frank R. Wagner ◽  
Wentao Hu ◽  
Akos Spiegel ◽  
Nandor Vago ◽  
Bernold Richerzhagen
Keyword(s):  
Nd:Yag Laser ◽  
High Speed ◽  
Green Laser ◽  
Water Jet ◽  
Electronic Packages

Strength of deposited high-speed steel in the process of gas laser cutting

2009 ◽  
Vol 51 (7-8) ◽  
pp. 352-355 ◽  
Author(s):  
L. E. Afanas’eva ◽  
I. A. Barabonova ◽  
N. S. Zubkov ◽  
M. S. Razumov
Keyword(s):  
Laser Cutting ◽  
High Speed ◽  
High Speed Steel ◽  
Gas Laser ◽  
Gas Laser Cutting

scholarly journals Vision-Based Finger Tapping Detection Without Fingertip Observation

2021 ◽  
Vol 33 (3) ◽  
pp. 484-493
Author(s):  
Shotaro Narita ◽  
◽  
Shingo Kagami ◽  
Koichi Hashimoto
Keyword(s):  
High Speed ◽  
Feature Vector ◽  
False Positive Rate ◽  
Finger Tapping ◽  
Surface Patch ◽  
Operating Characteristics ◽  
Machine Learning Approach ◽  
History Information ◽  
Characteristics Analysis ◽  
Positive Rate

A machine learning approach is investigated in this study to detect a finger tapping on a handheld surface, where the movement of the surface is observed visually; however, the tapping finger is not directly visible. A feature vector extracted from consecutive frames captured by a high-speed camera that observes a surface patch is input to a convolutional neural network to provide a prediction label indicating whether the surface is tapped within the sequence of consecutive frames (“tap”), the surface is still (“still”), or the surface is moved by hand (“move”). Receiver operating characteristics analysis on a binary discrimination of “tap” from the other two labels shows that true positive rates exceeding 97% are achieved when the false positive rate is fixed at 3%, although the generalization performance against different tapped objects or different ways of tapping is not satisfactory. An informal test where a heuristic post-processing filter is introduced suggests that the use of temporal history information should be considered for further improvements.

scholarly journals On multi-sensor monitoring of fiber laser fusion cutting

2021 ◽  
Vol 1135 (1) ◽  
pp. 012014
Author(s):  
Nikita Levichev ◽  
Joost R. Duflou
Keyword(s):  
Fiber Laser ◽  
Monitoring System ◽  
Laser Cutting ◽  
High Speed ◽  
Process Zone ◽  
Industrial Process ◽  
Industrial Applications ◽  
Laser Fusion ◽  
Thick Plates ◽  
Sensor Monitoring

Abstract Laser cutting is a well-established industrial process for sheet metal applications. However, cutting thick plates is still accompanied by problems because of the characteristic limited process parameter window. Since cutting by means of fiber lasers has become dominant, tailored solutions are required in such systems for industrial applications. The development of a robust real-time monitoring system, which adapts the process parameters according to a specific quality requirement, implies a significant step forward towards automated laser cutting and increases the process robustness and performance. In this work, a coaxial multi-sensor monitoring system is tested for fiber laser cutting of stainless steel thick plates. A high-speed camera and a photodiode sensor have been selected for this investigation. Experiments at different cutting speeds, representing primary cut quality cases, have been conducted and various features of the obtained process zone signals have been examined. Finally, the feasibility of industrial application of the developed setup for high-power fiber laser cutting is discussed, followed by several implementation recommendations.

scholarly journals Study of high Speed Laser Cutting of LED Module

2017 ◽  
Vol 24 (1) ◽  
pp. 91-101
Author(s):  
Won Yong Choi ◽  
Sung-Hoon Choa
Keyword(s):  
Laser Cutting ◽  
High Speed

Aerodynamic Characteristics Analysis of High-Speed Train on Cutting under Crosswinds

2013 ◽  
Vol 300-301 ◽  
pp. 62-67
Author(s):  
Kun Ye ◽  
Ren Xian Li
Keyword(s):  
High Speed ◽  
Three Dimensional ◽  
Aerodynamic Characteristics ◽  
High Speed Train ◽  
Aerodynamic Forces ◽  
Cutting Depth ◽  
Cutting Slope ◽  
Characteristics Analysis ◽  
Relationship Of ◽  
The Relationship

Cutting is an effective device to reduce crosswind loads acting on trains. The cutting depth, width and gradient of slope are important factors for design and construction of cutting. Based on numerical analysis methods of three-dimensional viscous incompressible aerodynamics equations, aerodynamic side forces and yawing moments acting on the high-speed train, with different depths and widths of cutting，are calculated and analyzed under crosswinds，meanwhile the relationship of the gradient of cutting slope and transverse aerodynamic forces acting on trains are also studied. Simulation results show that aerodynamic side forces and yawing moments acting on the train（the first, middle and rear train）decrease with the increase of cutting depth. The relationship between transverse forces (moments) coefficients acting on the three sections and the cutting depth basically is the three cubed relation. The bigger is cutting width，the worse is running stability of train. The relationship between yawing moments coefficients acting each body of the train and the cutting width approximately is the three cubed relation. The transverse Aerodynamic forces decreased gradually with the increase of the gradient of cutting slope, the relationship between yawing moments coefficients acting each body of the train and the gradient of cutting slope basically is the four cubed relation.

Modeling and Analysis for Thermal Control of Spindles for Reconfigurable Machines

2001 ◽  
Author(s):  
Jeffrey L. Stein ◽  
John E. Harder
Keyword(s):  
High Speed ◽  
Metal Cutting ◽  
Closed Loop ◽  
Dynamic Performance ◽  
Thermal Control ◽  
Open Loop ◽  
Limiting Factor ◽  
Process Conditions ◽  
Bearing Load ◽  
Bearing Loads

Abstract Control of thermally induced bearing loads remains an important but unsolved problem for precision, high-speed, metal cutting, machining spindles. Spindle dynamic performance, as well as spindle life, depends on bearing loads. Because these loads can change drastically with a change in process conditions, poor spindle dynamic performance, and dramatically reduced bearing life can result. The purpose of this paper is to evaluate the feasibility of controlling bearing loads by controlling the heat generated by a thermal actuator placed around the housing of the spindle. A mathematical model of the open loop response of a laboratory prototype spindle is developed and validated. The model is then used to evaluate the closed loop performance. The results show that closed loop control of the bearing load is achievable in steady state and under bandwidth limited transient conditions. The proposed system has reasonable command authority when additional heat is required, however, it is possible for the system to lose control when the heater is required to “provide” negative heat. This situation can be mitigated by proper choice of initial preload. As expected, measurement noise limits the control gain but is not a limiting factor. More open loop tests are suggested to validate the model under a broader set of conditions. In addition, closed loop validation is suggested. However, based on results obtained it appears bearing load control is achievable by controlling the thermal field around the spindle.

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