A long-term bonded polytetrafluoroethylene copper-clad laminate and preparation method thereof

Abstract

The invention discloses a polytetrafluoroethylene copper-clad laminate with long-term bonding, which is composed of a copper foil layer, a first bonding layer, a polytetrafluoroethylene layer, a second bonding layer and an epoxy resin FR-4 layer , wherein the copper foil layer and the polytetrafluoroethylene layer are bonded through the first adhesive layer, and the polytetrafluoroethylene layer and the epoxy resin FR-4 layer are bonded through the second adhesive layer, and the polytetrafluoroethylene The layer is made by sintering polytetrafluoroethylene powder with a core-shell structure, and the individual particles of the polytetrafluoroethylene powder with a core-shell structure include polytetrafluoroethylene particles, coupling agent, polyetheretherketone . The polytetrafluoroethylene copper-clad laminate of the present invention has excellent bondability between layers, has low dielectric constant and dielectric loss, and does not affect the high frequency of polytetrafluoroethylene, and can meet the requirements of polytetrafluoroethylene copper-clad laminates. The use in the high-frequency field can be widely used in the manufacture of high-frequency PCB circuit boards such as 5G.

Description

technical field [0001] The invention belongs to the field of copper-clad laminates, and in particular relates to a long-acting bonded polytetrafluoroethylene copper-clad laminate and a preparation method thereof. Background technique [0002] With the rapid development of the high-frequency communication industry, more and more stringent requirements are put forward for the performance of copper clad laminates. Polytetrafluoroethylene (PTFE) resin, as a completely symmetrical polymer material without branched chain lines, has low dielectric constant and dielectric loss, and has become a typical resin for high-frequency copper clad laminates. However, PTFE's self-lubricating properties, extremely low surface energy and chemical inertness make it difficult to bond with other materials, which limits its application in the copper clad laminate industry. [0003] At present, in order to improve the bonding performance of PTFE, some methods have been proposed including: [0004]...

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Problems solved by technology

[0004] (1) Chemical treatment method, generally using sodium naphthalene solvent as corrosive liquid to tear off some fluorine atoms on the surface of PTFE, leaving a carbonized layer and polar groups such as hydroxyl, carbonyl, and unsaturated bonds on the surface, which improves the viscosity of PTFE Junction performance, but this method reduces the insulation performance of PTFE;

[0005] (2) High-temperature melting method, which changes the crystallization of PTFE surface at high temperature, and embeds substances with high surface energy and easy adhesion such as SiO 2 , Al powder, etc., which improve the bonding performance of PTFE, but this method requires high temperature treatment, harsh conditions, and high cost;

[0006] (3) Radiation grafting method, using 60CO as a radiation source to undergo graft polymerization on the surface of PTFE, so that a layer of bondable graft polymer is formed on the surface of PTFE to improve the bonding performance, but this method is complicated in process and harmful to people. severe bodily injury;

[0007] (4) Low-temperature plasma treatment method, under the action of an electric field, the gas is excited by high-energy electrons to generate rays, which can chemically react with the surface of PTFE to introduce oxygen-containing groups, generate polarity, increase surface tension, and improve the bonding performance of PTFE , but this method requires high-energy electron excitation, harsh conditions, and high cost;

[0009] The printed circuit board (PCB) copper clad laminates manufactured by the above method have a common outstanding problem that the bonding lacks long-term performance. In the process of over-high temperature baking oven or long-term use, PTFE and copper foil or PTFE and epoxy resin There will be problems such as blistering and delamination between FR-4 substrates, which will seriously affect the practical application of PTFE copper clad laminates.

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