The increased demand for smaller and more reliable electronic devices, pressures companies to tune and innovate the production methodologies, always aiming to decrease the production time while maintaining the products’ quality. In the manufacturing of a Printed Circuit Board (PCB), there are two main types of electronic components, which are characterized by the connection they form to the main board, namely, Surface-Mount-Devices (SMD) and Through-Hole (TH) components. Both connections are achieved through soldering, which is an essential manufacturing process that greatly affects the quality of the final product, and may compromise the lifetime of the PCB.SMD components, generally of smaller size, are commonly soldered by a reflow process, which consists of four sub-steps, stencil printing, stencil removal, component placement, and reflow oven soldering. This is a fast and widely applied process that can be used to solder several components in one go. In turn, TH components are generally soldered by a wave soldering process, which involves pumping molten solder from a solder bath onto the bottom of the board. Then, through capillarity, the liquid solder fills the board apertures creating a connection between the component and the board upon solidification. Since a PCB is generally composed of both types of components, SMD and TH, this requires the use of both soldering processes. Additionally, since both processes are too different in nature, the manufacturing of the board requires two separated mounting lines which represent increased costs and production time. For this reason, nowadays, the tendency is to replace the wave soldering process with the reflow soldering process even for TH components. This achievement will provide lower costs and a reduction of time in the process associated with PCB manufacturing.To better understand the particularities of this transition, the present study investigates the usage of the reflow solder printing as a mean to deposit the solder paste on through-hole apertures. Given the potential of computational simulations to predict, improve and optimize the soldering processes, in the present study a simplified 2D numerical model was developed using the work-package ANSYS FLUENT and a multiphase approach.From the present work, promising results were obtained, demonstrating an opportunity for the development of a less time-consuming process with a good aperture filling. However, experimental tests are needed to validate the numerical simulations. The experimental apparatus is already under development and will be tested in the near future, before implementing the reflow process on the process line.

Numerical Simulation of Solder Paste Printing on Through-Hole Components

Paper Proceedings: https://asmedigitalcollection.asme.org/IMECE/IMECE2021/volume/85543

ASME 2021 International Mechanical Engineering Congress and Exposition (IMECE2021)

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