Core-shell structure conductive microsphere with adjustable specific gravity as well as preparation method and application of core-shell structure conductive microsphere

Abstract

The invention discloses a core-shell structure conductive microsphere with adjustable specific gravity as well as a preparation method and application of the core-shell structure conductive microsphere. The conductive microsphere comprises a ceramic microsphere serving as a core and a metal shell layer coating the surface of the ceramic microsphere. The ceramic microsphere and metallized paste are used as raw materials, and the surface of the ceramic microsphere is coated with the metal shell layer with a certain thickness through a solid-phase sintering method. By adopting the metallization method disclosed by the invention, the bonding strength of the obtained metal shell layer and the surface of the ceramic microsphere core is high, the core-shell structure is compact, the metal shell layer is not easy to fall off, and the diameter of the obtained conductive microsphere with the core-shell structure is adjustable between 1-2000 [mu]m; meanwhile, the overall specific gravity of the core-shell structure microsphere can be adjusted by adjusting the diameter of the ceramic microsphere and the thickness of the coating metal shell layer, so that the conductive microsphere with different use requirements can be obtained; and further electroplating treatment can be carried out on the metal shell layer to improve the conductivity and smoothness of the metal shell layer, so that the application field of the conductive microsphere is widened.

Description

technical field [0001] The invention belongs to the field of materials, and in particular relates to a core-shell conductive microsphere with adjustable specific gravity, a preparation method and application thereof. Background technique [0002] With the development of mobile communication networks, commercial wireless frequency bands have become very dense, so that ordinary metal cavity filters cannot achieve high-rejection system compatibility, and the use of ceramic dielectric materials to make cavity filters can solve the above problems. Based on the above performance advantages, cavity filters made of ceramic dielectric materials have been developed rapidly. [0003] However, when the ceramic cavity filter pad is electroplated with a nickel-tin metal layer, the electroplating process requires the use of conductive balls as the cathode conductive medium, which is in contact with the silver metal pad of the filter, and then the nickel in the nickel-plating and tin-platin...

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Problems solved by technology

In addition, it is also required that the density of the conductive balls is close to the density of the ceramic medium of the filter to achieve better plating of the nickel-tin metal layer; The ball and filter are layered so that they do not function as a conductive medium

[0004] Conventionally used stainless steel balls have a specific gravity between 7.70-8.00, and their specific gravity is greater than that of ordinary ceramic media. When used as a conductive medium for barrel plating, it is easy to delaminate with the ceramic parts of the filter, resulting in lower plating yields. Low

Moreover, ordinary stainless steel balls are large in size, and the effect is poor when used as a conductive medium.

[0005] In order to overcome the above-mentioned technical defects, how to develop conductive microspheres with a density close to that of the filter ceramics and at the same time have a suitable size, so as to avoid the microspheres being too small to easily pass through the hole screen of the plating cylinder, free on the outside of the plating cylinder, and If the size is too large, the poor effect of the conductive medium will become a technical problem to be solved urgently

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