Temperature Control System for Accelerated Aging Tests on Printed Circuit Boards

In this paper is presented an automated system that is dedicated for testing the electronic assemblies from the point of view of resistance to temperature variations. The system consists of a sealed thermal enclosure with a volume of one cubic decimeter and an accurate, digital control module that can perform preprogrammed temperature cycling tests on various equipped and unequipped printed circuit boards. The control architecture of the proposed design is based on the versatile PIC16F877 microcontroller. The cooling and heating of the thermal enclosure is actually realized using Peltier elements and resistors with the power of approximately 50W. The system can operate standalone or connected to a PC through a standard serial interface. When the external connection is used, the control module sends the locally displayed parameters and the measured data also to the PC. In addition, the bidirectional communication with PC allows the remote control and a closer integration of the proposed system into an extended testing network that can perform highly complex and customized climatic tests on electronic boards.