Micro-Texture Dependence of the Strength of Fine Metallic Bumps Used for Electronic Packaging

Author(s):  
Fumiaki Endo ◽  
Naokazu Murata ◽  
Ken Suzuki ◽  
Hideo Miura

Electroplated copper bumps expected as fine metallic bumps for electronic packaging were investigated experimentally considering the change of micro texture dependence of their electroplating conditions and heat treatment after the electroplating. Not only Young’s modulus but also the strength of electroplated copper thin films changed drastically depending on the change of their micro texture, and these values were significantly different from conventional bulk copper. In addition, the strong anisotropy of Young’s modulus was observed between that along their thickness direction, and that parallel to their plane direction.

2007 ◽  
Vol 353-358 ◽  
pp. 2954-2957 ◽  
Author(s):  
Hideo Miura ◽  
Kazuhiko Sakutani ◽  
Kinji Tamakawa

The mechanical properties of copper thin films deposited by sputtering and electroplating were compared using tensile test and nano-indentation. Both the Young’s modulus and tensile strength of the films were found to vary drastically depending on the microstructure of the deposited films. The Young’s modulus of the sputtered film was almost same as that of bulk material. However, the Young’s modulus of the electroplated thin film was about a fourth of that of bulk material. The micro structure of the electroplated film was polycrystalline and a columnar structure with a diameter of a few hundred-micron. The strength of the grain boundaries of the columnar grains seemed to be rather week. In addition, there was a sharp distribution of Young’s modulus along the thickness direction of the film. Though the modulus near the surface of the film was close to that of bulk material, it decreased drastically to about a fourth within the depth of about 1 micron. There was also a plane distribution of Young’s modulus near the surface of the film.


Author(s):  
Muneyuki Otani ◽  
Kazuhiko Sakutani ◽  
Kinji Tamakawa ◽  
Ken Suzuki ◽  
Hideo Miura

The mechanical properties of copper thin films formed by cold-rolling and electroplating were measured using a tensile test and nano-indentation. Both the Young’s modulus and the tensile strength of the films were found to vary drastically depending on the microstructure of the films. The Young’s modulus of the cold-rolled film was almost same as that of the bulk material. However, the Young’s modulus of the electroplated thin film was about a fourth of that of the bulk material. The microstructure of the electroplated film was polycrystalline and a columnar structure with a diameter of a few hundred-micron. The strength of the grain boundaries of the columnar grains seemed to be rather week. Such a columnar structure with porous grain boundaries caused the cooperative grain boundary sliding. As a result, the effective elasticity of the film became rather low and the superplastic deformation of the film appearred under an uni-axial tensile load. In addition, there was a sharp distribution of Young’s modulus along the thickness direction of the film. Though the modulus near the surface of the film was close to that of the bulk material, it decreased drastically to about a half at the depth of 1 μm. There was also a planar distribution of Young’s modulus near the surface of the film.


Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 153
Author(s):  
Chuen-Lin Tien ◽  
Tsai-Wei Lin

This paper proposes a measuring apparatus and method for simultaneous determination of the thermal expansion coefficient and biaxial Young’s modulus of indium tin oxide (ITO) thin films. ITO thin films simultaneously coated on N-BK7 and S-TIM35 glass substrates were prepared by direct current (DC) magnetron sputtering deposition. The thermo-mechanical parameters of ITO thin films were investigated experimentally. Thermal stress in sputtered ITO films was evaluated by an improved Twyman–Green interferometer associated with wavelet transform at different temperatures. When the heating temperature increased from 30 °C to 100 °C, the tensile thermal stress of ITO thin films increased. The increase in substrate temperature led to the decrease of total residual stress deposited on two glass substrates. A linear relationship between the thermal stress and substrate heating temperature was found. The thermal expansion coefficient and biaxial Young’s modulus of the films were measured by the double substrate method. The results show that the out of plane thermal expansion coefficient and biaxial Young’s modulus of the ITO film were 5.81 × 10−6 °C−1 and 475 GPa.


1993 ◽  
Vol 308 ◽  
Author(s):  
Sandrine Bec ◽  
André Tonck ◽  
Jean-Luc Loubet

ABSTRACTPyrolysis of polymer precursors (polysilazane) is a technologically and economically interesting way to produce thin ceramic coatings. However, many cracks appear and decohesion occurs during pyrolysis when the ceramic coatings (SiOCN) are thicker than 0.5 micrometers. In order to understand these cracking phenomena, the coatings are mechanically characterized by nanoindentation at different stages of the pyrolysis heat treatment.During pyrolysis, the cracking temperature is detected by in-situ optical observation. The thickness of the coatings varies during pyrolysis from 3 micrometers at the polymeric state to 1 micrometer at the ceramic state. The coatings' properties, hardness and Young's modulus are evaluated after heat treatment, taking into account the substrate's influence. A large variation of these properties occurs at the cracking temperature. Both the hardness and the Young's modulus are multiplied by a factor of 10. By analysing these results, we show that cracking is correlated with the evolution of the coatings' mechanical properties during the transformation.


1999 ◽  
Vol 594 ◽  
Author(s):  
T. Y. Zhang ◽  
Y. J. Su ◽  
C. F. Qian ◽  
M. H. Zhao ◽  
L. Q. Chen

AbstractThe present work proposes a novel microbridge testing method to simultaneously evaluate the Young's modulus, residual stress of thin films under small deformation. Theoretic analysis and finite element calculation are conducted on microbridge deformation to provide a closed formula of deflection versus load, considering both substrate deformation and residual stress in the film. Silicon nitride films fabricated by low pressure chemical vapor deposition on silicon substrates are tested to demonstrate the proposed method. The results show that the Young's modulus and residual stress for the annealed silicon nitride film are respectively 202 GPa and 334.9 MPa.


2016 ◽  
Vol 18 (31) ◽  
pp. 21508-21517 ◽  
Author(s):  
Xiao-Ye Zhou ◽  
Bao-Ling Huang ◽  
Tong-Yi Zhang

Surfaces of nanomaterials play an essential role in size-dependent material properties.


1994 ◽  
Vol 60 (572) ◽  
pp. 1108-1113
Author(s):  
Hidetoshi Yanai ◽  
Nobuyuki Kishine ◽  
Yukari Komaba ◽  
Yukitaka Murakami

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