Low-loss high-uniformity bonding sheet and preparation method of multilayer microwave plate

Abstract

The invention relates to a low-loss high-uniformity bonding sheet and a preparation method of a multilayer microwave plate. The bonding sheet is composed of an upper thermosetting resin adhesive film and a lower thermosetting resin adhesive film of a fluorine-based composite film. The components of the upper thermosetting resin adhesive film and the lower thermosetting resin adhesive film are both thermosetting resin, an initiator and a filler, and a thermoplastic elastomer, a flame retardant, an antioxidant and a plasticizer can be added to the thermosetting resin, the initiator and the filler to achieve a specific function, wherein the thermosetting resin and the thermoplastic elastomer are matrixes, the cross-linking agent, the flame retardant, the antioxidant and the plasticizer are additives, and the filler is a reinforcing material; the additive and the reinforcing material are randomly distributed in the matrix; the thermosetting resin adhesive film is in a semi-cured or uncured state, has certain fluidity and is prepared on the upper surface and the lower surface of the fluorine-based composite film through a coating process. The components have the characteristic of high uniformity and do not contain glass fiber cloth, so that the influence of a glass fiber effect on high-frequency signal transmission is avoided.

Description

technical field [0001] The invention relates to the technical field of microwave copper-clad laminates, in particular to a low-loss and high-uniform bonding sheet and a method for preparing a multilayer microwave board. Background technique [0002] With the rapid development of electronic information technology, microwave circuit components are moving towards integration and miniaturization. The ordinary single-layer microwave composite dielectric substrate can no longer meet the actual requirements. The multilayer microwave Composite dielectric substrates have gradually become a hot spot in research and application. At the same time, the increase in transmission signal frequency also puts forward higher requirements on the loss factor of dielectric materials. The traditional epoxy resin system has been gradually eliminated by high-end applications due to its high loss factor. Fluorine-based resin materials represented by polytetrafluoroethylene have become the preferred s...

AI Technical Summary

Problems solved by technology

However, its large thermal expansion coefficient, non-hydrophilic and non-oleophilic surface, and high melting point (327°C) limit its application in adhesive sheets.

[0003] The new bonding sheet involved in Chinese patent CN212451274U includes a fluorine-containing resin layer and has a first surface and a second surface oppositely arranged, and the dielectric loss of the thermosetting resin arranged on the first surface and the second surface is less than or equal to 0.005, higher than Material requirements for microwave circuits, and the patent does not mention the thermal expansion coefficient performance of the bonding sheet

In high-frequency applications, the weaving structure of glass fiber cloth will cause differences in dielectric constant in small areas, which will cause "glass fiber effect", affect the stability and reliability of signal transmission, and cannot achieve high uniformity of dielectric constant ; and the thickness of the substrate formed by impregnation of glass fibers also fluctuates due to the weaving of glass fibers, resulting in low uniformity of dielectric constant

Multi-layer microwave boards made of adhesive sheets with low uniformity will cause wave distortion and other problems in high-frequency signal transmission.

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