Graduation Semester and Year
2022
Language
English
Document Type
Thesis
Degree Name
Master of Science in Mechanical Engineering
Department
Mechanical and Aerospace Engineering
First Advisor
Agonafer Dereje
Abstract
Micro-via are components that are used to form connections from one layer to another in most Multilayered Printed Circuit Boards (PCBs). The failure of Micro-via has always been a concern of the electronic industry. The failures are exaggerated during the reflow process due to the high thermal loading. Electronic components have become ubiquitous in our society. It is important to take some measures to reduce (or) eliminate the failures at interconnects in the Printed Circuit Board to obtain highly reliable Input/Output (I/O). This work is based on a hypothetical belief that the possible cause of failure is an insufficient or limited time for a Micro-via on the top layer to settle the grain structure from the induced internal stresses from reflow and assembly procedures of manufacturing High-Density Interconnect (HDI) Printed Circuit Board (PCB) with multiple layers along with the depth of via. This can be a valid reason for reliability issues related to Micro-vias that tend to cause failures. So, A finite element model of blind micro-via is developed to meet IPC standards and incorporated into a multi-layered PCB. According to IPC 2.6.27(B) test method, the model is tested with thermal cycling. Further models are modified to verify the effects of the hypothesis the model is modified to simulate the heterogeneous grain boundary by changing the modulus of the blind micro-via along with the depth. Since the blind micro-via goes through the minimum pressure and temperature cycle during the fabrication it is assumed that the annealing of the copper is not fully achieved. It is found that the stress distribution in the blind micro-via is higher for the heterogenous micro-via and is 10.4% higher than the homogenous micro-via for the same Thermal loading condition. Moreover, the stress in the micro-via with the modulus increasing along the depth is higher than the modulus decreasing along the depth.
Keywords
Micro via, Axisymmetric, Reliability
Disciplines
Aerospace Engineering | Engineering | Mechanical Engineering
License
This work is licensed under a Creative Commons Attribution-NonCommercial-Share Alike 4.0 International License.
Recommended Citation
Bazaru, Jayendra, "COMPUTATIONAL RELIABILITY ANALYSIS OF BLIND MICRO-VIA WITH 3D AND AXISYMMETRIC MULTI-LAYER PCB" (2022). Mechanical and Aerospace Engineering Theses. 1002.
https://mavmatrix.uta.edu/mechaerospace_theses/1002
Comments
Degree granted by The University of Texas at Arlington