Free ground film, circuit board and preparation method of free ground film

Abstract

The invention relates to the field of electronics, and discloses a free ground film, a circuit board and a preparation method of the free ground film. The free ground film includes adhesive film layers and N conductor layers. A conductive adhesive layer is arranged between two adjacent conductor layers. An adhesive film layer is arranged on the side, which is away from the conductive adhesive layer, of each conductor layer. At least one conductor layer is provided with a through hole penetrating the upper and lower surfaces thereof, which is beneficial for volatiles in the adhesive film layersto be exhausted through the through hole of the conductor layer at high temperature. The volatiles in the adhesive film layers can be easily discharged. Separation between the free ground film and anelectromagnetic shielding film caused by blistering and layering of the free ground film is prevented, so as to ensure that interference charges are led out. When the free ground film is used for grounding of a printed circuit board, the electromagnetic shielding film is arranged on the printed circuit board. When the free ground film is laminated with the electromagnetic shielding film, the non-flat surface of each conductor layer penetrates each adhesive film layer and the insulating layer of the electromagnetic shielding film and is electrically connected with the shielding layer of the electromagnetic shielding film, so that interference charges are led out through the free ground film.

Description

technical field [0001] The invention relates to the field of electronics, in particular to a free grounding film, a circuit board and a method for preparing the free grounding film. Background technique [0002] With the rapid development of the electronics industry, electronic products are further developed toward miniaturization, light weight, and high-density assembly, which greatly promotes the development of flexible circuit boards, thereby realizing the integration of component devices and wire connections. Flexible circuit boards can be widely used in industries such as mobile phones, liquid crystal displays, communications and aerospace. [0003] Driven by the international market, functional flexible circuit boards dominate the flexible circuit board market, and an important indicator for evaluating the performance of functional flexible circuit boards is Electromagnetic Interference Shielding (EMI Shielding). With the integration of functions of communication equi...

AI Technical Summary

Problems solved by technology

However, in the process of implementing the present invention, the inventors have found that there are at least the following problems in the prior art: there are volatiles in the conductive adhesive layer under high temperature conditions, but because the conductor layer is relatively dense, the volatiles are difficult to discharge, resulting in free grounding Film bubbling and delamination cause peeling between the free grounding film and the electromagnetic shielding film, which in turn causes the grounding failure of the electromagnetic shielding film, and the interference charge cannot be exported

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