Daito T.,Osaka University |
Nishikawa H.,Osaka University |
Takemoto T.,Osaka University |
Matsunami T.,Okuno Chemical Industries Co.
Microelectronics Reliability | Year: 2013
Solder joints are required to have high impact strength for use in portable electronic products. To make solder joints with high impact strength, qualitative evaluation methods of impact strength are required. Ball impact tests have been widely adopted in evaluating the impact strength of solder joints because of their easy implementation. Impact load curves obtained from ball impact tests are used as an evaluation indicator of impact strength of solder joint. However, a relation between fracture behavior and impact load curve has not yet been clarified, and an explanation of the impact load curve has not yet been provided in detail. In addition to this, detailed study about the relation between IMC layer thickness and impact strength has not been performed, although the IMC layer thickness formed at the interface would significantly affect the impact strength of the solder joint. This study aimed to explain the impact load curve in the ball impact test and to reveal the effect of the IMC layer thickness on the impact strength of the solder joint. Sn-3.0Ag-0.5Cu solder was reflowed on an electroless Ni-P plated Cu substrate (Ni-P), and a ball impact test was then carried out to evaluate the impact strength. This study found that the ball impact test is effective to evaluate the interfacial strength of solder joints. In the impact load curve, it is estimated that the solder bump keeps deforming until the interfacial crack initiates (maximum load), and the interfacial crack initiates after the maximum load and propagates along the interface between the solder and Ni-P. The suitable evaluation of impact strength became possible by measuring the correspondence relation between the deformation distance of the solder bump after fracture and the energy until maximum load and the relation between the area fraction of the residual solder on the fractured pad and the energy after maximum load. And, it is proved that the impact strength decreased with increasing aging time because the growth of the IMC layer remarkably degraded the interfacial strength of the solder joint. © 2013 Elsevier Ltd. All rights reserved. Source
Okuno Chemical Industries Co. | Date: 2015-09-18
Chemical products for treating the surface of aluminum and aluminum alloys; industrial chemicals for use in plating; chemical agent for use in etching the surface of aluminum and aluminum alloys; chemical conversion treatment agent for treating the surface of aluminum and aluminum alloys; chemical rust prevention treatment agent for treating the surface of aluminum and aluminum alloys; metal and plastic plating chemical compositions; metal etching mordants; industrial chemicals.
Okuno Chemical Industries Co. | Date: 2014-07-24
Okuno Chemical Industries Co. | Date: 2013-04-18
The present invention provides a blackening treatment method for a black CrCo alloy plating film, the method comprising bringing a black CrCo alloy plating film having a Cr content of 1 to 15 wt. % into contact with a blackening treatment solution comprising an aqueous solution with a pH value of 1 to 5. According to the present invention, the blackish color of a less blackish plating film formed from a plating bath containing trivalent chromium is enhanced to further improve decorativeness. Furthermore, the corrosion resistance of the film can be more improved by performing electrolytic chromate treatment after blackening treatment.
Toyota Jidosha Kabushiki Kaisha and Okuno Chemical Industries Co. | Date: 2010-09-14
A production method of an electroless plating material of the present invention is a method for the production of an electroless plating material that has a surface to be plated by electroless plating, and includes an ozone treatment step in which a material body that is made of a resin is brought into contact with a solution that contains ozone to form a modified layer in a surface of the material body, and a superficial layer removal step in which, after the ozone treatment step, the surface of the material body is irradiated with ultraviolet rays to remove a superficial layer of the modified layer.