Lifetime prediction of copper pillar bumps based on fatigue crack propagation

IF 2.6 4区材料科学 Q3 MATERIALS SCIENCE, MULTIDISCIPLINARY

Frontiers in Materials Pub Date : 2024-09-02 DOI:10.3389/fmats.2024.1470365

Yuege Zhou, Qingsheng Liu, Tengfei Ma, Shupeng Li, Xinyu Zhang

{"title":"Lifetime prediction of copper pillar bumps based on fatigue crack propagation","authors":"Yuege Zhou, Qingsheng Liu, Tengfei Ma, Shupeng Li, Xinyu Zhang","doi":"10.3389/fmats.2024.1470365","DOIUrl":null,"url":null,"abstract":"2.5D package realizes the interconnection of multiple dies through Si interposers, which can greatly improve the data transmission rate between dies. However, its multi-layer structure and high package density also place higher reliability requirements on the interconnection structure. As a key structure for interconnection, copper pillar bump (CPB) has small size, high heat generation, and thermal mismatch with silicon chips. The thermal fatigue failure of CPB has gradually become the main failure mode in 2.5D package. Due to the small size of CPB and the large proportion of intermetallic compound (IMC) layers, the lifetime prediction method of spherical solder joints is no longer suitable for CPB. Therefore, it is necessary to establish a fatigue lifetime prediction method for CPB. This paper establishes a method for obtaining the lifetime of CPB based on the basic theory of fatigue crack propagation. Using the extended finite element simulation method, the crack propagation lifetime of CPB under thermal cycling was obtained, and the influence of different IMC layer thickness on the fatigue lifetime of CPB was analyzed. The results indicated that the fatigue lifetime of cracks propagating in the IMC layer is lower than that of cracks propagating in the solder layer, and an increase in the thickness of the IMC layer leads to a significant decrease in the fatigue lifetime of CPB. The lifetime prediction method for CPB proposed in this paper can be used for reliability evaluation of 2.5D package, and has certain reference value for the study of the lifetime of CPB.","PeriodicalId":12524,"journal":{"name":"Frontiers in Materials","volume":null,"pages":null},"PeriodicalIF":2.6000,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Frontiers in Materials","FirstCategoryId":"88","ListUrlMain":"https://doi.org/10.3389/fmats.2024.1470365","RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"MATERIALS SCIENCE, MULTIDISCIPLINARY","Score":null,"Total":0}

引用次数: 0

Abstract

2.5D package realizes the interconnection of multiple dies through Si interposers, which can greatly improve the data transmission rate between dies. However, its multi-layer structure and high package density also place higher reliability requirements on the interconnection structure. As a key structure for interconnection, copper pillar bump (CPB) has small size, high heat generation, and thermal mismatch with silicon chips. The thermal fatigue failure of CPB has gradually become the main failure mode in 2.5D package. Due to the small size of CPB and the large proportion of intermetallic compound (IMC) layers, the lifetime prediction method of spherical solder joints is no longer suitable for CPB. Therefore, it is necessary to establish a fatigue lifetime prediction method for CPB. This paper establishes a method for obtaining the lifetime of CPB based on the basic theory of fatigue crack propagation. Using the extended finite element simulation method, the crack propagation lifetime of CPB under thermal cycling was obtained, and the influence of different IMC layer thickness on the fatigue lifetime of CPB was analyzed. The results indicated that the fatigue lifetime of cracks propagating in the IMC layer is lower than that of cracks propagating in the solder layer, and an increase in the thickness of the IMC layer leads to a significant decrease in the fatigue lifetime of CPB. The lifetime prediction method for CPB proposed in this paper can be used for reliability evaluation of 2.5D package, and has certain reference value for the study of the lifetime of CPB.

查看原文本刊更多论文

基于疲劳裂纹扩展的铜柱凸块寿命预测

2.5D 封装通过硅插芯实现了多个芯片的互连，可大大提高芯片间的数据传输速率。然而，其多层结构和高封装密度也对互连结构的可靠性提出了更高的要求。作为互连的关键结构，铜柱凸块（CPB）具有体积小、发热量大、与硅芯片热不匹配等特点。CPB 的热疲劳失效已逐渐成为 2.5D 封装的主要失效模式。由于 CPB 体积小、金属间化合物（IMC）层比例大，球形焊点的寿命预测方法已不再适用于 CPB。因此，有必要建立一种适用于 CPB 的疲劳寿命预测方法。本文基于疲劳裂纹扩展的基本理论，建立了一种获得 CPB 寿命的方法。利用扩展有限元模拟方法，得到了热循环条件下 CPB 的裂纹扩展寿命，并分析了不同 IMC 层厚度对 CPB 疲劳寿命的影响。结果表明，在 IMC 层中传播的裂纹的疲劳寿命低于在焊料层中传播的裂纹的疲劳寿命，而 IMC 层厚度的增加会导致 CPB 疲劳寿命的显著降低。本文提出的 CPB 寿命预测方法可用于 2.5D 封装的可靠性评估，对研究 CPB 的寿命具有一定的参考价值。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Frontiers in Materials Materials Science-Materials Science (miscellaneous)

CiteScore

4.80

自引率

6.20%

发文量

749

审稿时长

12 weeks

期刊介绍： Frontiers in Materials is a high visibility journal publishing rigorously peer-reviewed research across the entire breadth of materials science and engineering. This interdisciplinary open-access journal is at the forefront of disseminating and communicating scientific knowledge and impactful discoveries to researchers across academia and industry, and the public worldwide. Founded upon a research community driven approach, this Journal provides a balanced and comprehensive offering of Specialty Sections, each of which has a dedicated Editorial Board of leading experts in the respective field.