Abstract
The paper represents technical diagnostics of printed circuit boards in particular their solder joints performed by commonly used through-hole and surface mount technologies. Operation and technology cause mechanical interactions and forces between substrate of printed circuit board and electronic components. Such tensile, shear, bending or torque forces transmit through the contact joints, which appear to be the weakest links in the assembly. The experimental research was conducted by mechanical tensile and pure bending tests followed by using method of acoustic emission. Conducted tests demonstrated considerable sensitivity and applicability for the method of acoustic emission to detect defects and possibly to assess the ultimate strength of solder joints in nondestructive diagnostics performed under forces long before the final failure. In order to minimize errors while measuring small loads in tensile tests of ceramic capacitors the special appliance was designed. The experiment was conducted to verify the overheating effect to ultimate load of the solder joints. Surface mount technology for ceramic capacitors has been optimized by introducing high temperature preheating mode that improves adherence to the contact pads and increases tensile strength, what was also confirmed by acoustic emission analysis. The pure bending appliance was designed to provide instant monitoring of all solder joints by equal testing stress. By conducted pulsing test cycles the total count was identified as the most informative parameter of acoustic emission that correlates with types of defects and ultimate strength of the solder joints. The planar location model has been developed by the idea of remote detection of acoustic emission through the volume of homogeneous medium such as water, unlike detecting acoustic emission on the surface of printed circuit board where acoustic emission signal is likely to be distorted or even lost. Using method of acoustic emission and pure bending cycling test the method for technical diagnostics of solder joints has been designed. The results represented in the paper contribute to design and technology improvement in radio-electronics.
Highlights
Modern trend to manufacture ever smaller mechanical, optical and electronic products and devices compromises quality and reliability standards of their components
The comparative analysis was made among three types of solder joints for acoustic emission parameters recorded within the force range from 0 to
Data analysis testified that overheating of solder joints improves their adherence to the contact pads and increases their tensile strength
Summary
Modern trend to manufacture ever smaller mechanical, optical and electronic products and devices compromises quality and reliability standards of their components. Operation and even technology cause mechanical interactions and forces, acting between PCB substrate and electronic components, and spreading through their links. Despite existing of the wide range of methods for non-destructive or destructive SJ tests provided by the state standard [7,8,9] they do not always provide proper quality selection and control. Such methods use measuring electric (resistance), electrically parametric (amplitude frequency response) or physical parameters for quality control of Reliability Improvement of Printed Circuit Boards by Designing Methods for Solder Joint Technical Diagnostics. The experimental research was conducted by using mechanical tensile and pure bending tests simultaneously with method of acoustic emission with recording acoustic emission parameters against applied forces and mechanical characteristics in order to find relationship between parameters of acoustic emission and such defects of solder joints as cold joint and low solder adhesion
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
