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Gang bonding process (GBP) using thermal compression bonder (TCB) is being developed recently as a means to massively stack multi chips. However, the GBP using the TCB has a difficulty in misalignment of stacked chips due to the difference in thermal expansion rate on the bonding head and the top surface of the chip. To overcome this problem, we have developed a facility for gang bonding without misalignment by thermal expansion of overhead. For bonding between chip and chip, non-conductive film (NCF) was used for the test vehicle. To achieve good quality bonding, wetting should occur on solder bumps and pads that connect chips and chips. For this, the NCF film must reach the lowest viscosity before solder bump melt and when the solder bump melts before the NCF cured. In addition to curing behavior between NCF and solder bump, press strength and time are also the core of the process. Therefore, a more detailed process for GBP is required than the existing process of the TCB method in the past. The design the optimal process for GBP only by experiment is timing-consuming and expensive. Therefore, we simulated the curing behavior of NCF and designed the customized process of the GBP. Firstly, the curing behavior of NCF was measured using the differential scanning calorimetry (DSC) and cure-kinetics was analyzed by building Kamal's model. Secondly, the viscosity behavior of NCF was measured using Rheometer and rheokineics was analyzed by constructing Macosko's model. Through this built model, NCF behavior was predicted during the gang manufacturing process using GBP and a suitable process was designed. We could find the optimal process through D.O.E in the designed process, and we checked the perfect wetting between solder bump and pad and the proper gap height between chip and chip.

Shipbuilding processes involve highly dangerous manual welding operations. Welding ship walls inside double-hulled structures presents a particularly hazardous environment for workers. This paper describes the ''Rail Runner X'' (RRX), a new robotic system that can move autonomously inside the walls of a double-hulled ship and automatically execute the required welding processes. The RRX robotic system is composed of a mobile platform and a welding robot consisting of a 3P3R serial manipulator. The robot is used to weld U-shaped trajectories located between two longitudinal stiffeners. The mobile platform enables traverse movements onto neighboring longitudinal stiffeners. The entire cross section of the robotic system is small enough to be placed inside the double-hulled structure via a conventional access hole from the outside shipyard floor. The overall engineering design process that led to the final robot solution developed is presented in this paper, including kinematic analysis data and experimental results for verifying the autonomous movement and welding performance.

‘Seoul National University’ and ‘Daewoo Shipbuilding & Marine Engineering’ in Korea jointly developed a mobile welding robot, the ‘Rail Runner’ (RRX), which is able to freely move in both transverse and longitudinal directions, and perform welding tasks in double hull structures. Recently, RRX2, (the second version of RRX), was presented at ‘Robotics and Applications 2007'. In this paper, the design, manufacturing, and application of RRX3, the third version of RRX, is described. The moving mechanism of RRX, which is able to move freely in a double hull structure, has two functions. 1) To move in a longitudinal direction by driving wheels using longi. faces as ‘rails', and 2) To move in a transverse direction by sliding along supporting longi. faces using extension arms. The body of the RRX3 is composed of a 12-axis, 6-axis mobile platform that supports the RRX moving mechanism and a 6-axis welding robot to do the welding job. The main point in designing RRX3 is to make it capable of passing through a 600mm×800mm sized access hole, the entrance into an enclosed double hull structure. The full size of the manufactured RRX3 is 1825mm×495mm×569mm, and thus the RRX3 is able to pass through an access hole. The weight is 250kg with a 6-axis mobile platform, 6-axis welding robot, and mounted controller.