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1 – 9 of 9Discusses three simple and low‐cost flip chip assembly processes. First, flip chip on board using non‐conductive adhesive is evaluated. This process can give reasonable…
Abstract
Discusses three simple and low‐cost flip chip assembly processes. First, flip chip on board using non‐conductive adhesive is evaluated. This process can give reasonable reliability and high assembly yield, when the parameters for epoxy placement and bonding are optimised. Second, the flip chip assembly process using reflowable no‐flow underfill is discussed. Because the underfill epoxy is already placed in the gap between the IC chip and the substrate before reflow, it is not easy to control the solder joints’ collapse and obtain the desired solder‐joint shapes and stand‐off distance during reflow. Finally, the stud bump bonding process is also discussed. It is not easy although possible to maintain the optimal dipping of the conductive adhesive, when the average height of the gold bumps is small. Some solutions for overcoming the above‐mentioned difficulties are presented in this paper.
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This paper discusses flip chip on FR‐4 and ceramics using non‐conductive adhesive (NCA), anisotropic conductive film (ACF), or anisotropic conductive paste (ACP). Several ACF and…
Abstract
This paper discusses flip chip on FR‐4 and ceramics using non‐conductive adhesive (NCA), anisotropic conductive film (ACF), or anisotropic conductive paste (ACP). Several ACF and ACP materials with different types of adhesive resin and conductive particles and one NCA material were evaluated. Flip chips were assembled on test vehicles for temperature cycling and high‐temperature high‐humidity tests. The reliability performance of the processes was compared. Flip chip processes using NCA, ACF, or ACP could give satisfactory reliability and high assembly yield for some applications, when the bonding parameters were optimised.
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A reliable packaging process for flip chip on ceramic substrate using gold bumps and adhesive was successfully developed. The bonding parameters and flip chip assemblies using…
Abstract
A reliable packaging process for flip chip on ceramic substrate using gold bumps and adhesive was successfully developed. The bonding parameters and flip chip assemblies using four adhesive materials were investigated by means of design of experiments and yield runs. The packaging yield was 100 per cent. All the packages assembled during the yield runs passed various reliability tests. The packages attained 100 per cent reliability required for an industrial application.
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The stud bump bonding (SBB) process was evaluated for a flip chip in package application. An SBB packaging process, having a reduced number of process steps compared with the…
Abstract
The stud bump bonding (SBB) process was evaluated for a flip chip in package application. An SBB packaging process, having a reduced number of process steps compared with the typical SBB process, was proposed. The two separate steps of curing of conductive adhesive and underfill epoxy, which for the application targeted in this study needed a total of four hours for curing plus further time for cooling, were not required. This proposed process therefore resulted in a reduced packaging time. Several issues affecting the assembly are also discussed in this paper.
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Reports the research and development results on flip chip on FR‐4 and ceramics, using anisotropic conductive film (ACF), anisotropic conductive paste (ACP), or eutectic solder…
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Reports the research and development results on flip chip on FR‐4 and ceramics, using anisotropic conductive film (ACF), anisotropic conductive paste (ACP), or eutectic solder with underfill. Several types of ACF and ACP with different types of conductive particles and adhesives were investigated. Simple but high yield procedures for reworking flip chip on board using ACP and ACF were developed. Processes for flip chip on FR‐4 and ceramic boards using eutectic solder bumps with underfill were also evaluated. The flip chips were assembled on test vehicles for temperature cycling and high‐temperature high‐humidity tests. The reliability performance of the three processes (gold bumps with ACF, gold bumps with ACP, and eutectic solder bumps with underfill) is compared.
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This paper discusses processes of flip chip on FR‐4 using eutectic solder bumps with possible fewer process steps compared to the full assembly process. Some interesting results…
Abstract
This paper discusses processes of flip chip on FR‐4 using eutectic solder bumps with possible fewer process steps compared to the full assembly process. Some interesting results in terms of the reliability performance of flip chip on FR‐4 assemblies using eutectic solder have been obtained after an almost‐one‐year temperature cycling test. The process steps of underfilling and curing of underfill can be omitted when a suitable epoxy is used for encapsulation. When underfill is conducted, encapsulation is not necessarily needed from a reliability point of view.
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Zhaowei Zhong and Peng Kiong Yip
A three‐dimensional (3D) package consisting of a stack of three silicon chips was conceptually designed. A finite element simulation of this 3D package was conducted in order to…
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A three‐dimensional (3D) package consisting of a stack of three silicon chips was conceptually designed. A finite element simulation of this 3D package was conducted in order to compare the fatigue lives of the solder joints with those in a typical single flip chip package when subjected to a cyclic thermal loading. It was found that the proposed design of the 3D package was feasible in terms of its mechanical deformation response to the thermal cycle.
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Flip chips were assembled on to ceramic boards using eutectic tin‐lead solder with underfill and with/without encapsulation for temperature cycling and…
Abstract
Flip chips were assembled on to ceramic boards using eutectic tin‐lead solder with underfill and with/without encapsulation for temperature cycling and high‐temperature‐high‐humidity tests. After 1.5 years of testing, the reliability performance of the flip chip on board (FCOB) assemblies was compared. All of the FCOB assemblies with underfill, but without encapsulation, survived 5,778 cycles of the temperature cycling test following 5,005 hours of the high‐temperature and high‐humidity test. The results show that encapsulation may not necessarily enhance the reliability of flip chip assemblies and might therefore be omitted.
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Hui Zhang, Jinwen Tan, Chenyang Zhao, Zhicong Liang, Li Liu, Hang Zhong and Shaosheng Fan
This paper aims to solve the problem between detection efficiency and performance in grasp commodities rapidly. A fast detection and grasping method based on improved faster R-CNN…
Abstract
Purpose
This paper aims to solve the problem between detection efficiency and performance in grasp commodities rapidly. A fast detection and grasping method based on improved faster R-CNN is purposed and applied to the mobile manipulator to grab commodities on the shelf.
Design/methodology/approach
To reduce the time cost of algorithm, a new structure of neural network based on faster R CNN is designed. To select the anchor box reasonably according to the data set, the data set-adaptive algorithm for choosing anchor box is presented; multiple models of ten types of daily objects are trained for the validation of the improved faster R-CNN. The proposed algorithm is deployed to the self-developed mobile manipulator, and three experiments are designed to evaluate the proposed method.
Findings
The result indicates that the proposed method is successfully performed on the mobile manipulator; it not only accomplishes the detection effectively but also grasps the objects on the shelf successfully.
Originality/value
The proposed method can improve the efficiency of faster R-CNN, maintain excellent performance, meet the requirement of real-time detection, and the self-developed mobile manipulator can accomplish the task of grasping objects.
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