OVERVIEW OF THE USE OF X-RAY EQUIPMENT IN ELECTRONICS QUALITY TESTS

Surface-mount technology is now widely used in the production of many components. The development of the miniaturised electronics industry forces the development of increasingly accurate inspection methods. X-ray and computed tomography are methods to accurately assess the quality of a circuit board. The article discusses the basics of image formation of the tested electronics, the development of the design of the devices used and examples of x-ray, computed tomography applications.

ANALYSIS OF MACHINE AVAILABILITY AT SURFACE-MOUNT TECHNOLOGY (SMT) LINE USING WITNESS SIMULATION

In the competition to excel in the Industrial 4.0 race, companies especially in Semiconductor Industry, strive to attain efficiency by removing process bottlenecks, improving productivity and increasing machine availability during operation. As so, this research was conducted to analyze the machine’s availability based on various preventive maintenance (PM) scheduling. A model was developed in WITNESS 14 Manufacturing Performance Edition software to imitate the Surface-mount Technology (SMT) line in a manufacturing system. The model was build based on a serial layout of five machines which are a screen printer, glue dispenser, chip shooter, pick and place and reflow oven. Then, the simulation was run to study the availability of each machine with relation to different stoppages intervals and duration based on the selected PM schedule. The findings of this project show that PM for an SMT line should be carried out every week with 30 minutes PM duration to achieve high machine availability and minimal machine downtime.

A Novel Placement Method for Mini-Scale Passive Components in Surface Mount Technology

This paper aims to propose a novel placing method, i.e., place-between-paste-and-pad (PB), for mini-scale passive components to enhance electronic assembly lines' yield. PB means a component is designed to be placed at the midpoint between the pastes and pads on the length direction while it aligns with the pads' center on the width direction. An experiment that involves 12 printed circuit boards (PCB) is designed and conducted to get comparative results. Four PCBs are employed for place-on-pad (PP), place-on-paste (PPS), and PB separately. On each board, 375 resistors R0402M (0.40 mm X 0.20 mm) are assembled horizontally. To study the components' misalignment under various solder paste offset conditions in different placement methods, a stencil with 25 solder paste offset settings is utilized. Based on this experiment's results, PB has superior performance to the other two methods to minimize components' misalignment. Regarding the number of acceptable components when post-reflow offsets are within 25% of components' dimensions, PB and PP have equivalent performances, and they both outperform PPS. Furthermore, PB is a low-cost placing strategy because PB needs not the real-time communication between the solder paste inspection machine and the pick-and-place machine. With the miniaturization trend in electronic products, the post-reflow components' misalignment is more frequently observed than before. The placement method proposed in this study is expected to offer a low-cost exploration in the component pick-and-place procedure to enhance the surface mount technology (SMT) assembly quality.