Although plating is a necessary process for SMT components, it alters the magnetic characteristics and inductance level of Ni-Cu-Zn ferrite components. The results of this work show that the following three factors in...Although plating is a necessary process for SMT components, it alters the magnetic characteristics and inductance level of Ni-Cu-Zn ferrite components. The results of this work show that the following three factors in plating affect these components, and the effects are different for Ni- and Sn-plating： （1） Plating layers exert stresses and react with the residual stress of components to change the inductance level, and the effect of the tin layer is greater than that of the nickel one; （2） The plating current induces a magnetic field inside the components directly and indirectly, and this remains as remanence inside the components and reduces the inductance level, and the effect level of Ni-plating is greater than that of Sn-plating; （3） The plating solution corrodes the interface of the termination and ferrite core of the components to release the residual stress, and causes an increase in inductance, and the effect of Sn-plating is greater than that of Ni-plating. In addition, the inductance level is the result of the net effect of these three factors, and if the sintering temperature is increased to change in the type of residual stress, the net effect will be changed.展开更多
Ni-Cu-Zn ferrite components are very sensitive to stress and this can cause unstable permeability.This work focuses on the source of stress,and the interaction between the residual stress after sintering and the furth...Ni-Cu-Zn ferrite components are very sensitive to stress and this can cause unstable permeability.This work focuses on the source of stress,and the interaction between the residual stress after sintering and the further stresses contributed by subsequent manufacturing processes of multilayer chip inductors.The results show that the sources of stress include cofiring of ferrite and silver coils,and the operations involved in the manufacturing processes.The results also show that the stresses pass through the interfaces between materials to the body of component and that the stresses induced in the subsequent manufacturing processes would accumulate or counteract with the residual stress in the component,although the stress can also be released by changing the connection status of these interfaces.The results also show that the compressive and tensile stresses cause different levels of inductance shift.展开更多
文摘Although plating is a necessary process for SMT components, it alters the magnetic characteristics and inductance level of Ni-Cu-Zn ferrite components. The results of this work show that the following three factors in plating affect these components, and the effects are different for Ni- and Sn-plating： （1） Plating layers exert stresses and react with the residual stress of components to change the inductance level, and the effect of the tin layer is greater than that of the nickel one; （2） The plating current induces a magnetic field inside the components directly and indirectly, and this remains as remanence inside the components and reduces the inductance level, and the effect level of Ni-plating is greater than that of Sn-plating; （3） The plating solution corrodes the interface of the termination and ferrite core of the components to release the residual stress, and causes an increase in inductance, and the effect of Sn-plating is greater than that of Ni-plating. In addition, the inductance level is the result of the net effect of these three factors, and if the sintering temperature is increased to change in the type of residual stress, the net effect will be changed.
文摘Ni-Cu-Zn ferrite components are very sensitive to stress and this can cause unstable permeability.This work focuses on the source of stress,and the interaction between the residual stress after sintering and the further stresses contributed by subsequent manufacturing processes of multilayer chip inductors.The results show that the sources of stress include cofiring of ferrite and silver coils,and the operations involved in the manufacturing processes.The results also show that the stresses pass through the interfaces between materials to the body of component and that the stresses induced in the subsequent manufacturing processes would accumulate or counteract with the residual stress in the component,although the stress can also be released by changing the connection status of these interfaces.The results also show that the compressive and tensile stresses cause different levels of inductance shift.
