Characterization and Modeling of Fine-Pitch Copper Ball 4 Bonding on a Cu/Low-k Chip

Page view(s)
21
Checked on Nov 29, 2024
Characterization and Modeling of Fine-Pitch Copper Ball 4 Bonding on a Cu/Low-k Chip
Title:
Characterization and Modeling of Fine-Pitch Copper Ball 4 Bonding on a Cu/Low-k Chip
Journal Title:
Journal of Electronic Materials
Keywords:
Publication Date:
17 December 2014
Citation:
Abstract:
Cu ball bonding faces more challenges than Au ball bonding, for example, excessive deformation of the bond pad and damage of Cu/low-k structures, because of the much greater hardness of Cu free air balls. In this study, dynamic finite-element analysis (FEA) modeling with displacement control was developed to simulate the ball-bonding process. The three-dimensional (3D) FEA simulation results were confirmed by use of stress-measurement data, obtained by use of stress sensors built into the test chip. Stress comparison between two-dimensional (2D) and 3D FEA models showed the 2D plain strain model to be a reasonable and effective model for simulation of the ball-bonding process without loss of accuracy; it also saves computing resources. The 2D FEA model developed was then used in studies of a Cu/low-k chip to find ways of reducing Al bond pad deformation and stresses of low-k structures. The variables studied included Al pad properties, capillary geometry, bond pad design (Al pad thickness, Al pad coated with Ni layer), and the effect of ultrasonic bonding power.
License type:
PublisherCopyrights
Funding Info:
Description:
Full paper can be downloaded from the Publisher's URL provided.
ISSN:
0361-5235
1543-186X
Files uploaded:

File Size Format Action
pub14-002-ipp-mtmc-001-pp-2.pdf 1.82 MB PDF Open