Flexible manufacturing method for long-period fibre gratings with arbitrary index modulation profiles

Author(s):  
M. Otto ◽  
F. Michael ◽  
T. Duthel ◽  
C. Schaffer
Author(s):  
Karthik Babu ◽  
Oisik Das ◽  
Vigneshwaran Shanmugam ◽  
Rhoda Afriye Mensah ◽  
Michael Försth ◽  
...  

Abstract3D printing or additive manufacturing (AM) is considered as a flexible manufacturing method with the potential for substantial innovations in fabricating geometrically complicated structured polymers, metals, and ceramics parts. Among them, polymeric composites show versatility for applications in various fields, such as constructions, microelectronics and biomedical. However, the poor resistance of these materials against fire must be considered due to their direct relation to human life conservation and safety. In this article, the recent advances in the fire behavior of 3D-printed polymeric composites are reviewed. The article describes the recently developed methods for improving the flame retardancy of 3D-printed polymeric composites. Consequently, the improvements in the fire behavior of 3D-printed polymeric materials through the change in formulation of the composites are discussed. The article is novel in the sense that it is one of the first studies to provide an overview regarding the flammability characteristics of 3D-printed polymeric materials, which will further incite research interests to render AM-based materials fire-resistant.


2009 ◽  
Vol 36 (8) ◽  
pp. 2042-2045 ◽  
Author(s):  
宋韵 Song Yun ◽  
朱涛 Zhu Tao ◽  
饶云江 Rao Yunjiang ◽  
赵英伟 Zhao Yingwei

2014 ◽  
Vol 2014 (DPC) ◽  
pp. 000815-000829 ◽  
Author(s):  
Tom Strothmann ◽  
Damien Pricolo ◽  
Seung Wook Yoon ◽  
Yaojian Lin

The demand for Wafer Level Chip Scale Packages (WLCSP) has experienced tremendous growth due to the surge in demand for advanced mobile products. The increased demand is seen for both 200mm wafers and 300mm wafers, however a significant segment of the market continues to be driven by 200mm designs. The infrastructure capacity supporting 200mm WLCSP has been stressed as a result of the mature status of 200mm technology and the rate of conversion of alternative package formats to WLCSP. This creates a dilemma for WLP service providers because adding 200mm capacity continues to require a significant amount of capital. Since 200mm volumes will most likely decline within the next 5 years, it is difficult to justify the use of capital when the depreciation term is longer than the anticipated life cycle of the product. Conventional methods of manufacturing wafer level packages require the use of equipment specifically sized to a given silicon wafer diameter although there is no technical requirement to maintain the round silicon format. The conventional method has been beneficial since it leveraged equipment and processes developed for the IC industry, however the equipment is very expensive for larger wafer diameters and the fine geometries required in advanced node IC products are not required for wafer level packaging. The problem is serious for 200mm and 300mm wafer bump lines, however the capital equipment cost for a future 450mm bumping line may well be prohibitive for wafer level packaging. A new manufacturing method has been developed to produce a wafer level package that severs the link between wafer diameter and wafer level packaging methods. The new manufacturing method is wafer size agnostic, so one manufacturing module can produce fan-in, fan-out, and 3D fan-out products regardless of the incoming wafer size. The same bill of materials, manufacturing methods and manufacturing location can produce wafer level packages from any size silicon wafer. In this method the wafer is diced prior to processing and then the die are recombined into a uniform panel size. Once recombined into a panel format, the product is processed with conventional wafer level packing techniques, including dielectric deposition, metal plating and solder ball drop. Since the manufacturing module is wafer size agnostic, there is no risk of capital for investment in the manufacturing infrastructure. A change in loading between 200mm, 300mm, and 450mm wafers does not adversely affect the utilization of the manufacturing module. The process also enables new advanced wafer level packages otherwise unattainable with conventional manufacturing methods. This presentation will describe the new manufacturing module approach and the results of process characterization for products produced in the module.


2010 ◽  
Vol 447-448 ◽  
pp. 795-800
Author(s):  
Daniel Scherer ◽  
Z. Yang ◽  
H. Hoffmann

This paper provides general information about the qualification of driving as an on-demand manufacturing concept for the production of individualized sheet metal products. Driving allows the creation of almost any 2D or 3D geometry, but it is a highly interactive, manual production process. Due to the inevitable variations of the incremental forming process (mechanical properties, tribology, wear etc.) and the high number of forming steps, it cannot be automated by traditional approaches. At the Institute of Metal Forming and Casting (Technische Universitaet Muenchen) a kraftformer machine has been equipped with measuring and controlling instrumentation. An optical online measurement system is installed to detect any geometry deformation of the current work piece and to visualize the deviation between the actual and the stored reference geometry during the whole production process. This variance comparison is the first step for planning any following incremental forming actions based on acquired and/or learned knowledge. The second step is the integration of an industrial robot for work piece handling and the automation of the whole manufacturing process. The last step is the integration of neural networks to predict production strategies for any desired unique geometry.


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