Diseño e Implementación de una Máquina CNC para la Fabricación de Placas de Circuito Impreso para Componentes SMD.

Abstract

It was designed and implemented a machine of computing numerical control (CNC) for the carving of printed circuit boards (PCB) for superficial montage devices (SMD) with 0.2mm precision, for the School of Electronics in Control and Industrial Networks in the Faculty of Computing and Electronics. This research work aims to reduce the costs of implementation of these electronic boards by means of the use of free software. The scientific method was used for the design of the control cabinet and mechanical adaptations, and the experimental method for the corresponding functioning test and the calculation of absolute and relative errors. For its implementations, it was used the mechanical structure of a CNC machine model 3020T, available in the market. The control of the machine was carried out with a board Arduino UNO programmed with the software GRBL designed for the control of CNC machines which receives commands and instructions from a computer through a USB port; these instructions come from a G code which is obtained through a free software called Flat Cam. The movement control of each axis was done with the JP-328A controller, which is designed based upon the TB6560AHQ, additionally it has race endings for the displacement control on X; Y axis. The machine can be used for the caving of PCB boards as well as the milling of MDF wooden pieces of low density using mills of adequate cut for this material. In the milling tests of 0.2mm, the results revealed a precision error lower than 1% by using the diameter of a mill tip of 0.1mm. As a conclusion, this error percentage resulted since there is not a thinner mill, no because of the machine movement precision. If the students of the School of Control require higher precision, it is recommended to use a laser carving machine like the ones used in the main factories which produce PCB.