Method for synthesizing polyimide precursor polymer resin and method for manufacturing single-sided flexible copper-clad plates

Abstract

The invention relates to a method for synthesizing polyimide precursor polymer resin and a method for manufacturing single-sided flexible copper-clad plates, which are applied to the technical field of microelectronics. An adhesive-free single-sided flexible copper-clad plate is obtained by the steps of: dissolving a monomer aromatic diamine in a non-proton polar solvent, stirring for dissolution, adding a silane coupling agent, stirring, adding an aromatic dianhydride monomer for polymerization to generate a polyimide precursor polymer resin solution, reacting and standing for defoaming; andcoating resin on a copper foil, pre-baking in an oven, removing the solvent, and heating in a gradient way in the high-temperature non-oxidation over (importing with nitrogen) so as to carry out complete imidization. The single-sided flexible copper-clad plate has the advantages that the heat resistance is good, the dimensional stability is strong, a substrate is thin, the peel strength is not less than 1.1kgf / cm, the polyimide resin is smooth and level after total etching, the elongation percentage is not less than 35%, the tensile strength is not less than 250MPa, the heat resistant temperature Tg of a polyimide insulation layer is not less than 328DEG C, and meanwhile, the plate has lower heat expansion coefficient, dielectric constant and water absorption rate.

Description

technical field [0001] The invention relates to the technical field of microelectronic materials, in particular to a method for synthesizing a polyimide prepolymer resin for an adhesive-free single-sided flexible copper-clad laminate and a method for manufacturing the single-sided flexible copper-clad laminate. Background technique [0002] Flexible printed circuit board, referred to as soft board, has the advantages of softness, lightness, thinness and flexibility. With the rapid trend of electronic products becoming lighter, thinner, shorter and smaller, it has been widely used in notebook computers, digital cameras, Mobile phones, liquid crystal displays and other electronic fields. [0003] Traditional soft board materials are mainly based on the three-layer structure of polyimide film / adhesive / copper foil, such as figure 1 As shown, the adhesive is mainly acrylic, and the soft board material with this structure has the following defects: [0004] 1. Poor heat resistan...

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Problems solved by technology

[0004] 1. Poor heat resistance: the long-term use temperature is limited to 100-200°C. When the temperature is higher than 120°C, the tear strength of the three-layer flexible board substrate will drop sharply due to the deterioration of the adhesive. When doing SMT welding, the temperature mostly exceeds 300°C. In addition, the temperature of the lamination process in the production of soft and rigid boards is also as high as 200°C. These applications are not suitable for the base material of the three-layer flexible board base material, and the application field is limited. ;

[0005] 2. The dimensional change rate of the three-layer flexible board is greatly affected by temperature, and the dimensional stability is poor;

[0006] 3. Poor chemical resistance: the base material of the three-layer rubberized soft board is poor in chemical resistance of the adhesive, and the tear strength decreases with time.

The secondary composite coating method also has very high requirements for the machine. Because two layers of resin are applied, the yield rate of the product is very low, and the polyimide resin of the adhesive layer in the middle is only 2-3um thick. The peel strength of adhesive flexible single-sided flexible copper clad laminates is also very low (0.4-0.7Kgf / cm), and the tensile strength (120-160MPa) and elongation (10-15%) of polyimide resin are also very low, see New Nippon Steel Chemical Patent JP2007059892, CN1678166

[0011] 1. Low peel strength (<0.8kgf / cm), the copper foil is easy to fall off from the substrate;

[0012] 2. The polyimide insulating layer is very brittle. After full etching, the tensile strength (<180MPa) and elongation (<15%) of polyimide are relatively low;

[0014] 4. The final product is seriously curled and warped

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