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

Abstract

The embodiment of the invention provides an electromagnetic shielding film, a circuit board and a preparation method of the electromagnetic shielding film, wherein the electromagnetic shielding film comprises a first shielding layer, a conducting resin layer, a second shielding layer, a third shielding layer and an adhesive film layer, which are sequentially stacked, a first through hole is formedin the second shielding layer, and a protrusion is arranged at the first through hole; the protrusion is formed by the conducting resin layer that flows from one side of the first through hole to theother side at a melting temperature and is immediately cooled; the third shielding layer is arranged on one side of the second shielding layer close to the protrusion and covers the protrusion, and aprotrusion portion is formed on the outer surface of the third shielding layer corresponding to the protrusion, the protrusion portion extends into the adhesive film layer, so that during the press fitting of the protrusion portion, the third shielding layer smoothly pierces the adhesive film layer and contacts a ground layer of the circuit board, and then the normal export of interference charges is ensured under the cooperation of the first shielding layer, the conducting resin layer, the second shielding layer and the third shielding layer, and a shielding function is realized.

Description

technical field [0001] The invention relates to the field of electronics, 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 shielding (Electromagnetic Interference Shielding, referred to as EMI Sh...

AI Technical Summary

Problems solved by technology

However, at high temperature, due to the expansion of the conductive adhesive layer, the conductive particles in the conductive adhesive layer that were originally in contact with each other or the conductive particles that were originally in contact with the circuit board ground layer were pulled apart, resulting in grounding failure, and the interference charge could not be quickly exported. , the shielding function cannot be realized

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