https://doi.org/10.1140/epjp/s13360-023-04355-w
Regular Article
Structural optimization of thermal stresses in BGA solder joints based on improved BP neural network-genetic algorithm
1
Tsinghua Shenzhen International Graduate School, Tsinghua University, 518055, Nanshan, Shenzhen, Guangdong, China
2
Department of Precision Instrument, Tsinghua University, 100084, Haidian, Beijing, China
a
haoyu-wa21@mails.tsinghua.edu.cn
Received:
5
March
2023
Accepted:
4
August
2023
Published online:
14
August
2023
Ball grid array (BGA) packages are prone to thermal stresses that bring about failure problems such as deformation and fracture of solder joints due to the mismatch in the coefficients of thermal expansion with surrounding materials. This paper aims to reduce the thermal stress by optimizing the three-dimensional spatial structure of BGA solder joints. In order to improve the design efficiency and accuracy of the computational model, the non-solder mask-defined type pads with Anand model are used and thermodynamic simulation is done in COMSOL software. This paper proposes an intelligent algorithm combining response surface method and neural network-genetic algorithm, which improves the accuracy of the system and can use limited data to find the minimum stress combination, as opposed to the conventional method, which has the issue of insufficient generalization capability. Bringing this method into the model, the minimum stress value is only 89.2157 MPa, which is 14% lower than the thermal stress of the conventional BGA structure. The scheme in this paper can greatly improve the design efficiency and increase the device lifetime in the form of reduced thermal stress.
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© The Author(s), under exclusive licence to Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature 2023. Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
