Development of Cu/Ni/SnAg Microbump Bonding Processes for Thin Chip-on-Chip Packages Via Wafer-Level Underfill Film
| Autor: | Ren-Chin Cheng, Chau-Jie Zhan, Kuo-Shu Kao, Tai-Hong Chen, Chang-Chun Lee, Tsung-Fu Yang |
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| Rok vydání: | 2012 |
| Předmět: |
Interconnection
Materials science business.industry Coplanarity Chip Industrial and Manufacturing Engineering Finite element method Electronic Optical and Magnetic Materials Microsystem Hardware_INTEGRATEDCIRCUITS Electronic engineering Optoelectronics Wafer Electrical and Electronic Engineering business Wafer-level packaging Flip chip |
| Zdroj: | IEEE Transactions on Components, Packaging and Manufacturing Technology. 2:1412-1419 |
| ISSN: | 2156-3985 2156-3950 |
| Popis: | 3-D integration provides a promising approach for the construction of complex microsystems through the bonding and interconnection of individually optimized device layers without sacrificing system performance. The use of traditional underfill processes is expected to face an arduous challenge as the filled gap of a large-scale chip is narrowed down to several micrometers. Consequently, the subsequent reliability of microbumps (μ-bumps) joints and the relative assembly compatibility of stacked chips of 3-D IC packages deteriorate. To resolve this critical issue, a novel technology for wafer-level underfill film (WLUF) is developed. This paper demonstrates the steps that the proposed technology would take. These steps include the alignment of the WLUF-coated chip to the substrate chip and the elimination of voids to make the proposed technology work. However, the coplanarity of stacked thin chips after assembling with the WLUF, is an urgent problem that needs to be understood in detail. Therefore, this paper presents a nonlinear finite element analysis (FEA) using a process-oriented simulation technique to estimate the warpage of stacked thin chips. For experimental validation, the effects of several key designed factors on the thermomechanical behavior of chip-on-chip package under various bonding forces are investigated. The analytic results indicate that a chip thickness of |
| Databáze: | OpenAIRE |
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