Electromagnetic shielding film, circuit board and preparation method of electromagnetic shielding film

Abstract

The invention relates to the technical field of electronics, and discloses an electromagnetic shielding film, a circuit board, and a preparation method of the electromagnetic shielding film. The electromagnetic shielding film comprises a shielding layer and an adhesive film layer. The adhesive film layer is arranged on the shielding layer. The surface, which is near the adhesive film layer, of theshielding layer is a non-flat surface. The shielding layer is provided with through holes penetrating the upper and lower surfaces thereof, which is beneficial for volatiles in the adhesive film layer to be exhausted through the through holes in the adhesive film layer at high temperature. Volatiles in the adhesive film layer can be easily discharged at high temperature. The electromagnetic shielding film is prevented from being peeled off from the ground layer of the circuit board due to bubbling and delamination of the electromagnetic shielding film. The electromagnetic shielding film is grounded, and interference charges are led out. In addition, the non-flat surface of the shielding layer pierces the adhesive film layer and is connected with the ground of the circuit board when the electromagnetic shielding film and the circuit board are pressed together. At the same time, gel substances are squeezed to the recesses of the non-flat surface to increase the adhesive capacity, whichprevents board burst, and ensures the connection of the shielding layer and the ground layer of the circuit board.

Description

technical field [0001] The invention relates to the field of electronic technology, in particular to an electromagnetic shielding film, a circuit board and a preparation method of the electromagnetic shielding 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 ...

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Problems solved by technology

However, in the process of implementing the present invention, the inventors 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 the shielding layer is relatively dense, and the volatiles are difficult to discharge, which in turn leads to blistering of the shielding film Delamination causes peeling between the electromagnetic shielding film and the ground layer of the circuit board, which leads to grounding failure and the inability to export interference charges

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