Transparent composite PI film, transparent composite PI substrate containing PI film and preparation method of transparent composite PI substrate

Abstract

The invention discloses a transparent composite PI film, a transparent composite PI substrate containing the PI film and a preparation method of the transparent composite PI substrate. The transparentcomposite PI substrate containing the PI film comprises: a first copper foil layer, an anti-UV transparent polyimide layer, an anti-UV transparent adhesive layer and a second copper foil layer; the light transmittance of the transparent composite PI film is larger than 88%, the haze is smaller than 1%, the L value of an L*a*b surface color system measured through an ultraviolet and visible lightbrightness meter is 92-99, the a value ranges from -2.0 to 2.0, the b value ranges from -2.0 to 2.0, the surface hardness is larger than 4H, and CTE is smaller than 30ppm; The glass-transition temperature of the anti-UV transparent polyimide layer is greater than 320DEG C; and the thickness of the transparent composite PI film is 8-70microm. The substrate provided by the invention has the advantages of extremely high penetration rate, extremely low haze, QUV irradiation resistance, high Tg, high deflection, low rebound force, voltage resistance and low CTE.

Description

technical field [0001] The invention belongs to the technical field of FPC (flexible circuit board) and its preparation, in particular to a double-sided copper foil substrate, which is mainly used in optical instruments, lighting instruments, touch screens, solar panels, flexible mobile phones, AMOLED (active matrix organic light emitting diodes) polar body), large-screen TV, vehicle-mounted display and other transparent substrates. Background technique [0002] Compared with traditional display technology, organic light-emitting diode (OLED) display technology has a series of advantages such as ultra-light, ultra-thin, wide viewing angle, high definition, low temperature resistance, and good shock resistance. Therefore, organic light-emitting display technology has made great progress in the past 20 years, and various high-performance and long-life organic light-emitting materials and devices have been continuously released. With the further development of organic light-em...

AI Technical Summary

Problems solved by technology

[0005] 1. The traditional PI film preparation method is casting method or film blowing method, followed by uniaxial or biaxial stretching, which requires high equipment and requires high temperature 500-800°C dehydration closed-loop treatment, the process is complicated and the cost is extremely high;

[0006] 2. It is difficult to make an ultra-thin 5-15um film, and the optical properties such as transmittance and haze are affected;

[0007] 3. Or without anti-UV absorber, it will turn yellow and become brittle under long-term ultraviolet light irradiation

[0009] 1. Transparent PET / PEN film and transparent glue are used to make transparent products, but because the melting point of PET / PEN is 225-260°C, the heat resistance is poor, and the FPC process that cannot withstand high temperature (288°C), such as SMT reflow soldering, needs to be applied. For flexible substrates;

[0010] 2. It is difficult to make an ultra-thin 5-15um film, and the optical properties such as transmittance and haze are affected, and its thickness is mostly above 25um;

[0011] 3. Due to the molecular structure, the overall CTE of PET / PEN materials is too large, which affects the design of downstream circuits, especially the design of thin circuits;

[0012] 4. Or without anti-UV absorber, it will turn yellow and become brittle under long-term ultraviolet light irradiation

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