Copper foil substrate for flexible printed circuit boards

Abstract

The invention discloses a copper foil substrate for flexible printed circuit boards. The copper foil substrate comprises a first copper foil, a polyimide layer and a second copper foil, wherein the polyimide layer is positioned between the first copper foil and the second copper, the thickness of the polyimide layer ranges from 7 micrometers to 150 micrometers, a first reflective layer is arranged between the second copper foil and the polyimide layer, or further, a second reflective layer is arranged between the first copper foil and the polyimide layer. The copper foil substrate with small thickness and low lightness can be obtained by adjusting the thickness of the polyimide layer, and the lightness of the copper foil substrate can be changed by adjusting content of additives contained in the first reflective layer and the second reflective layer. In addition, compared with the conventional copper foil substrate, the copper foil substrate has the advantages of higher lightness and higher heat dissipation, and meets requirements on white shielding or heat dissipation for flexible copper foil circuit substrates of electronic products.

Description

technical field [0001] The invention relates to a copper foil substrate, in particular to a copper foil substrate used for a flexible printed circuit board. Background technique [0002] At present, electronic systems are developing in the direction of lightness, thinness, high heat resistance, multi-functionality, high density, high reliability, and low cost. Therefore, the selection of substrates has become a very important factor. A good substrate must have material properties of high thermal conductivity, high color shielding effect, high heat dissipation, high heat resistance, and low thermal expansion coefficient. Polyimide resin has high thermal stability and excellent heat dissipation, mechanical strength, and adhesiveness, and is often used in various electronic materials, such as flexible printed circuit boards (Flexible Printed Circuit). [0003] Polyimide resin has been widely used in electronic materials, among which, the polyimide copper foil substrate used fo...

AI Technical Summary

Problems solved by technology

Usually, the problem with the application of polyimide copper foil substrates is that the composition and thickness of the polyimide material are limited, so that the formed polyimide layer is mostly yellow or other highly transparent Chromaticity, resulting in subsequent use in soft boards, due to the light transmittance of the polyimide layer, the circuit design distribution of the circuit layer of the flexible printed circuit board is easy to interpret and plagiarized by the same industry, which in turn affects the product's marketing and sales. Company operations

On the other hand, for electronic products such as light-emitting components, a solder mask and a reflective layer are often laid on the circuit, and the production process is relatively complicated.

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