Browsing by Author "Chen, Ming-Yao"

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Effect of Sn Grain Orientation on Formation of Cu6Sn5 Intermetallic Compound Under Current Stressing
(2017-04-01)
Chen, Ming-Yao
;
Lin, Han-wen
;
Chen, Chih
;
材料科學與工程學系
;
Department of Materials Science and Engineering
Solder joints with Cu/Sn-Ag/Cu structure and bump height of 15 mu m have been used to investigate the electromigration phenomenon at different temperatures and current densities. Moreover, the grain orientation was analyzed using electron backscatter diffraction. It was found that the anisotropic properties of tin affected the formation rate of Cu-Sn intermetallic compounds (IMCs), and that the angle between the electron flow direction and tin grain orientation played an important role in the formation of Cu6Sn5 IMC. With changes in angle, the diffusion rate of copper atoms in tin also varied. When the c-axis of tin was parallel to the electron flux, copper atoms diffused rapidly, resulting in fast formation of Cu-Sn IMCs. On the other hand, if the angle between the c-axis of the grain and the electron flow direction was large, the tin grains were more resistant to Cu diffusion during current stressing, leading to a very slow IMC formation rate.
Electromigration in reduced-height solder joints with Cu pillars
(2016-04)
Chen, Ming-Yao
;
Liang, Y. C.
;
Chen, Chih
;
材料科學與工程學系
;
Department of Materials Science and Engineering
This paper investigates the current-enhanced surface diffusion of solder along the side walls of Cu pillars. Two solder joints, Cu pillar/10-A mu m-solder/Ni and Cu pillar/Ni/10-A mu m-solder/Ni, were subjected to a 1.2 x 10(4) /cm(2) current density at 125 A degrees C for various amounts of time. The Sn atoms may diffuse to the Cu pillars side walls and form Cu6Sn5 intermetallic compounds (IMCs). Because the Sn atoms are drawn from the solder joints, serious voids are formed in these joints. Side diffusion is more serious for the Cu pillar/Ni/10-A mu m-solder/Ni joints than the Cu pillar/10-A mu m-solder/Ni joints because, instead of forming Ni3Sn4 IMCs, the Sn atoms prefer diffusing into the Cu side walls to form Cu6Sn5 IMCs. This Sn side diffusion accelerates the depletion of solder in the joints and thus may be a serious reliability issue for solder joints with a reduced solder height.
Fine pitch "NCF-type Compliant-bumped COG"
(2007)
An, Chao-Chyun
;
Chang, Shyh-Ming
;
Chen, Ming-Yao
;
Kao, Kuo-Shu
;
Tsang, Jimmy
Non-Conductive-Film (NCF) type of Chip-on-Glass (COG) bonding method ensures the micro-order direct bonding between the IC electrode and glass substrate electrode. The binding force of the applied adhesive achieves electrical connections between the bumps on the IC chip and the electrodes on the glass substrate. The mathematical calculation results of bump stress and bump deformation are used to identify the environmental temperature range for the given COG bonding structure. Both of the calculation and experimental results demonstrate the feasibility of using the compliant bumps to achieve a high compressive stress, high bump deformation and low as well as stable connection resistance at various environmental temperatures. The 1,000 hrs 85 degrees C/85%RH reliability test result will be indicated.
The brand-new high density "NCF=-type compliant-bumped COG" in high resolution LCD
(2007-01-01)
Chang, Shyh-Ming
;
Kao, Kuo-Shu
;
An, Chao-Chyun
;
Chen, Ming-Yao
;
Tsang, Jimmy
Non-Conductive-Film (NCF) bonding method ensures the micro-order direct bonding between the IC electrode and circuit substrate electrode. The binding force of the applied adhesive achieves electrical connections between the bumps on the IC chip and the electrodes on the substrate. The stress analysis results are used to identify the appropriate temperature range for the given NCF bonding structure. Both analytical and experimental results demonstrate the feasibility of using the compliant bumps to achieve a high compressive stress and low as well as stable connection resistance at various environmental temperatures.
Theoretical stress calculation and experimental results of "NCF-type compliant-bumped COG"
(2007)
Chen, Ming-Yao
;
An, Chao-Chyun
;
Chang, Shyh-Ming
;
Kao, Kuo-Shu
;
Tsang, Jimmy
Non-Conductive-Film (NCF) bonding method ensures the micro-order direct bonding between the IC electrode and circuit substrate electrode. The binding force of the applied adhesive achieves electrical connections between the bumps on the IC chip and the electrodes on the substrate. The stress analysis results are used to identify the appropriate temperature range for the given NCF bonding structure. Both analytical and experimental results demonstrate the feasibility of using the compliant bumps to achieve a high compressive stress and low, and stable connection resistance at various environmental temperatures. In addition, the reliability test results will be discussed.