KR102644252B1 - Electronic substrate manufacturing method using transparent polyimide sheet containing fluorine and electronic substrate manufactured thereof - Google Patents

Abstract

The present invention relates to a method of manufacturing an electronic board. Specifically, it uses transparent polyimide (PI) containing fluorine as a substrate to enable the use of lead, which melts above 200°C, thereby increasing the adhesion strength of electronic components to improve the product's quality. This relates to a method of manufacturing an electronic board using a transparent polyimide sheet containing fluorine to increase stability.

Description

Method for manufacturing electronic substrates using transparent polyimide sheets containing fluorine and electronic substrates manufactured thereby

The present invention relates to a method of manufacturing an electronic board. Specifically, it uses transparent polyimide (PI) containing fluorine as a substrate to enable the use of lead, which melts above 200°C, thereby increasing the adhesion strength of electronic components to improve the product's quality. This relates to a method of manufacturing an electronic board using a transparent polyimide sheet containing fluorine to increase stability.

Transparent substrates are used for various purposes. In particular, it is applied as a window cover substrate or protective film in various fields, including electronic products such as smartphones, tablet PCs, laptop PCs, AIO (All-In-One) PCs, LCD monitors, TVs, billboards, and touch panels. Transparent substrates are used as protective plates to protect internal items.

A typical example of a transparent substrate is glass, but transparent substrates made of plastic are widely used due to their strong brittleness (breakability).

Transparent plastic substrates include PC (polycarbonate) and PET. PE or PMMA are used.

Recently, the development of transparent substrates equipped with electrodes with fine line widths has been actively conducted. For example, LEDs can be mounted on a transparent substrate, and such a transparent LED substrate can be used as a display device (eg, LED signage) that provides various visual information to users.

Examples of such transparent substrates include Korea Patent Publication No. 10-2017-0009553, a transparent electrode substrate and its manufacturing method, and Korea Patent No. 10-2490506, a transparent display substrate manufacturing method with reduced shrinkage, and a transparent display substrate manufactured therefrom. etc. are disclosed.

The transparent electrode substrate and its manufacturing method include preparing a base material; Forming an alloy material layer on the base material; and forming a transparent conductive layer on the alloy material layer, wherein the step of forming the alloy material layer includes forming the alloy material layer by sputtering at a temperature of 50 to 80° C., and the alloy material layer includes, It contains ziconium kappa (ZrCu), and the base material has a thickness of 50 to 300㎛, and is made of polyethylene terephthalate (PET), polyurethane (PU), polyimide (PI), poly It includes at least one selected from the group consisting of ether sulfone (PES) and polycarbonate (PC).

The method of manufacturing a transparent display substrate with reduced shrinkage and the transparent display substrate manufactured therefrom include the steps of preparing a transparent base substrate of a flexible polymer material with a thickness of 100 to 300 ㎛; and pre-annealing the transparent base substrate at 150 to 198° C. for 1 to 5 minutes, wherein the maximum shrinkage rate of the transparent base substrate before performing the annealing and the maximum shrinkage rate of the transparent base substrate after performing the annealing The ratio satisfies 6 to 7: 1, and the average shrinkage rate of the transparent base substrate after performing the annealing is 0.1 to 0.2%, and the transparent base substrate is made of polyethylene naphthalene (PEN) or polyethylene terephthalate. (Poly Ethylene Terephthalate, PET), polyethylene (PE), and polycarbonate (PC).

However, when manufacturing such transparent substrates, copper (Cu) is generally deposited on polyethylene terephthalate (PET) and plated. Polyethylene terephthalate (PET) has a low melting point, so it is used when soldering electronic components. Since lead that melts at low temperatures must be used, there is a problem in that the adhesion strength of electronic components is low and use at high temperatures is limited.

Domestic Public Patent No. 10-2017-0009553 Domestic Registered Patent No. 10-2490506

The present invention is intended to solve the above problems, and uses transparent polyimide (PI) containing fluorine as a substrate to enable the use of lead, which melts above 200°C, thereby increasing the adhesion strength of electronic components and improving product stability. The purpose is to provide a method of manufacturing an electronic board using a transparent polyimide sheet containing fluorine to increase .

In addition, the present invention provides a transparent polyimide sheet containing fluorine that increases adhesion by increasing surface tension by performing surface treatment with an electron beam before depositing a metal on a transparent polyimide (PI) substrate containing fluorine. There is another purpose in providing a method of manufacturing an electronic board using the present invention.

In addition, the present invention provides a method of manufacturing an electronic board using a transparent polyimide sheet containing fluorine, which prevents cracks from occurring even when used in places with severe temperature changes due to the low coefficient of thermal expansion (CTE) of the board. There is a purpose.

The features of the present invention for achieving the above object are,

A protective film attachment process of attaching an OCA film, which is a protective film, to the bottom of a substrate that is a transparent polyimide sheet containing fluorine; A surface treatment process of placing the substrate with the OCA film attached on the bottom into a vacuum chamber, heating argon gas using an electron beam and colliding with the surface of the substrate to treat the surface to increase surface tension; A primary deposition process of placing the substrate in a vacuum chamber to increase adhesion strength to the surface-treated upper surface of the substrate, evaporating the alloy with an electron beam, and depositing the alloy on the substrate to form a primary deposition layer; A secondary deposition process of putting the substrate on which the primary deposition layer is deposited into a vacuum chamber, evaporating copper (Cu) with an electron beam, and depositing copper (Cu) on the substrate to form a secondary deposition layer; a primary plating process of forming a copper (Cu) plating layer through electrolytic plating on the substrate on which the first and secondary deposition layers are deposited; An etching process of wet etching the first and second deposition layers and the copper plating layer at once to form a metal circuit pattern; and a secondary plating process of forming a tin (Sn) plating layer on the copper plating layer on the upper surface of the metal circuit pattern through electrolytic plating to cover the color of the copper plating layer.

Here, the substrate has a thickness of 25 to 60㎛, transparency of 85 to 95%, and thermal expansion coefficient of 3 to 10 PPM.

Here, the OCA film is made of polyethylene terephthalate (PET) and has a thickness of 20 to 200 μm.

Here again, the alloy of the primary deposition layer is nickel (Ni)-copper (Cu) or nickel (Ni)-chromium (Cr).

Here again, when the alloy of the primary deposition layer is nickel (Ni)-copper (Cu), the ratio is 50 to 70:30 to 50% by weight.

Here again, when the alloy of the primary deposition layer is nickel (Ni)-chromium (Cr), the ratio is 70 to 98:2 to 30% by weight.

Here again, the primary deposition layer has a deposition thickness of 0.01 to 0.05 μm, and the secondary deposition layer has a deposition thickness of 0.05 to 0.2 μm.

Here again, the first plating process forms a copper (Cu) plating layer twice, with a thickness of 5 to 13 μm for the first plating and a thickness of 14 to 22 μm for the second plating.

Here again, the tin (Sn) plating layer has a plating thickness of 0.5 to 2 μm.

Another feature of the present invention is,

It features an electronic board manufactured by the electronic board manufacturing method using the above-mentioned transparent polyimide sheet containing fluorine.

According to the method of manufacturing an electronic board using a transparent polyimide sheet containing fluorine, which is configured as described above, it is possible to use lead that melts above 200°C by using transparent polyimide (PI) containing fluorine as a substrate. By doing so, the stability of the product can be improved by increasing the attachment strength of electronic components.

In addition, according to the present invention, surface treatment can be performed with an electron beam before depositing a metal on a fluorine-containing transparent polyimide (PI) substrate to increase surface tension and thereby increase adhesion.

In addition, according to the present invention, the coefficient of thermal expansion (CTE) of the substrate is low, so cracks can be prevented even when used in places where temperature changes are severe.

Figure 1 is a process diagram schematically showing a method of manufacturing an electronic substrate using a transparent polyimide sheet containing fluorine according to the present invention.
Figures 2 and 3 are explanatory diagrams to explain a method of manufacturing an electronic substrate using a transparent polyimide sheet containing fluorine according to the present invention.

Hereinafter, the method of manufacturing an electronic substrate using a transparent polyimide sheet containing fluorine according to the present invention will be described in detail with reference to the attached drawings.

In the following description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the gist of the present invention, the detailed description will be omitted. The terms described below are defined in consideration of the functions in the present invention, and may vary depending on the intention or custom of the user or operator. Therefore, the definition should be made based on the contents throughout this specification.

Figure 1 is a process diagram schematically showing a method of manufacturing an electronic substrate using a transparent polyimide sheet containing fluorine according to the present invention, and Figures 2 and 3 are a schematic diagram showing an electronic substrate manufacturing method using a transparent polyimide sheet containing fluorine according to the present invention. This is an explanatory diagram to explain the manufacturing method.

1 to 3, the method of manufacturing an electronic substrate using a transparent polyimide sheet containing fluorine according to the present invention includes a protective film attachment process (S10), a surface treatment process (S20), and a primary deposition process ( It consists of a second deposition process (S40), a first plating process (S50), an etching process (S60), and a second plating process (S70).

《Protective film attachment process-S10》

First, as shown in (a) of FIG. 2, the OCA film 20, which is a protective film, is attached to the bottom of the substrate 10, which is a transparent polyimide sheet containing fluorine.

At this time, the substrate 10 has a thickness of 25 to 60㎛, a transparency of 85 to 95%, and a thermal expansion coefficient of 3 to 10 PPM to prevent cracks due to the low thermal expansion coefficient even when using lead that melts above 200 ℃. It is preferable that the OCA film 20 is made of polyethylene terephthalate (PET) and has a thickness of 20 to 200 μm.

《Surface Treatment Process-S20》

When attachment of the OCA film 20 is completed, the substrate 10 with the OCA film 20 attached to the bottom is placed in a vacuum chamber, and argon gas is applied using an electron beam as shown in (b) of FIG. 2. It is heated and collides with the surface of the substrate 10 to treat the surface to increase surface tension.

In other words, the transparent polyimide film used as the substrate 10 is a polymer material that is in the spotlight as a material with excellent thermal stability, chemical resistance, and mechanical strength, and its application in the field of flexible printed circuit boards is expanding. there is. However, since there is no polar group on the surface, it has the disadvantage of reduced adhesion to metal.

In order to improve this disadvantage, in the present invention, fine curves with polar groups are formed on the surface of the substrate 10 to improve adhesion to the deposition layer and increase surface tension.

《Primary deposition process-S30》

When the surface treatment of the substrate 10 is completed, the substrate 10 is placed in a vacuum chamber to increase the adhesive strength on the upper surface of the surface-treated substrate 10, as shown in (c) of FIG. 2, and the alloy is added. The alloy is deposited on the substrate 10 by evaporation with an electron beam to form the primary deposition layer 30.

At this time, the alloy of the primary deposition layer 30 is nickel (Ni)-copper (Cu) or nickel (Ni)-chromium (Cr), and in the case of nickel (Ni)-copper (Cu), the ratio is 50 to 70: It is 30 to 50% by weight, and in the case of nickel (Ni) - chromium (Cr), the ratio is 70 to 98:2 to 30% by weight, and the deposition thickness is preferably 0.01 to 0.05㎛.

《Secondary deposition process-S40》

When the primary deposition is completed, as shown in (d) of FIG. 2, the substrate 10 on which the primary deposition layer 30 is deposited is placed in a vacuum chamber, and copper (Cu) is evaporated with an electron beam to form a substrate ( 10), copper (Cu) is deposited to form a secondary deposition layer 40.

At this time, the secondary deposition layer 40 preferably has a deposition thickness of 0.05 to 0.2 μm.

《First plating process-S50》

When secondary deposition is completed, as shown in (a) of FIG. 3, the substrate 10 on which the first and second deposition layers 30 and 40 are deposited is electroplated to form a copper (Cu) plating layer 50. forms.

At this time, the first plating process (S50) forms the copper (Cu) plating layer 50 twice, with a thickness of 5 to 13 μm for the first plating and a thickness of 14 to 22 μm for the second plating. Since the plating thickness can be up to 10~14㎛ in one plating, plating is performed twice.

《Etching Process-S60》

When the first plating is completed, the first and second deposition layers 30 and 40 and the copper plating layer 50 are wet-etched at once to form a metal circuit pattern (P), as shown in (b) of FIG. 3. To do so, a photoresist is attached to the metal circuit pattern (P) in the usual manner, and then etched with sulfuric acid and cleaned.

《Second plating process-S70》

When etching is completed, electrolysis is applied to cover the color of the copper plating layer 50 on the upper surface of the metal circuit pattern P formed on the substrate 10, as shown in (c) of FIG. 3. A tin (Sn) plating layer 60 is formed through plating.

At this time, the tin (Sn) plating layer 60 preferably has a plating thickness of 0.5 to 2 μm.

The present invention can be modified in various ways and can take various forms, and in the detailed description of the invention, only special embodiments thereof have been described. However, it should be understood that the present invention is not limited to the particular form mentioned in the detailed description, but rather is understood to include all modifications, equivalents and substitutes within the spirit and scope of the present invention as defined by the appended claims. It has to be.

10: Substrate 20: OCA film
30: primary deposition layer 40: secondary deposition layer
50: copper plating layer 60: tin plating layer

Claims (10)

It is a transparent polyimide sheet containing fluorine, its thickness is 25 to 60㎛, transparency is 85 to 95%, and the bottom of the substrate with a thermal expansion coefficient of 3 to 10 PPM is made of polyethylene terephthalate (PET). A protective film attachment process of attaching an OCA film, a 20-200㎛ protective film;
A surface treatment process of placing the substrate with the OCA film attached on the bottom into a vacuum chamber, heating argon gas using an electron beam and colliding with the surface of the substrate to treat the surface to increase surface tension;
In order to increase the adhesion strength to the upper surface of the surface-treated substrate, the substrate is placed in a vacuum chamber, the alloy is evaporated with an electron beam, and the alloy is deposited on the substrate to a thickness of 0.01 to 0.05 ㎛ to form a primary deposition layer. secondary deposition process;
The substrate on which the primary deposition layer is deposited is placed in a vacuum chamber, copper (Cu) is evaporated with an electron beam, and copper (Cu) is deposited on the substrate to a thickness of 0.05 to 0.2 μm to form a secondary deposition layer. secondary deposition process;
a primary plating process of forming a copper (Cu) plating layer through electrolytic plating on the substrate on which the first and secondary deposition layers are deposited;
An etching process of wet etching the first and second deposition layers and the copper plating layer at once to form a metal circuit pattern; and
It consists of a secondary plating process of forming a tin (Sn) plating layer on the upper surface of the metal circuit pattern through electrolytic plating to cover the color of the copper plating layer,
The first plating process is,
Electronics using a transparent polyimide sheet containing fluorine, which forms a copper (Cu) plating layer twice, with a thickness of 5-13㎛ for the first plating and a thickness of 14-22㎛ for the second plating. Substrate manufacturing method. delete delete According to claim 1,
The alloy of the primary deposition layer is,
A method of manufacturing an electronic board using a transparent polyimide sheet containing fluorine, characterized in that it is nickel (Ni)-copper (Cu) or nickel (Ni)-chromium (Cr). According to claim 4,
When the alloy of the primary deposition layer is nickel (Ni)-copper (Cu), the ratio is 50 to 70: 30 to 50% by weight. A method of manufacturing an electronic board using a transparent polyimide sheet containing fluorine. According to claim 1,
When the alloy of the primary deposition layer is nickel (Ni)-chromium (Cr), the ratio is 70 to 98: 2 to 30% by weight. A method of manufacturing an electronic substrate using a transparent polyimide sheet containing fluorine. delete delete According to claim 1,
The tin (Sn) plating layer is,
A method of manufacturing an electronic board using a transparent polyimide sheet containing fluorine, characterized in that the plating thickness is 0.5 to 2㎛. An electronic board manufactured by the electronic board manufacturing method using the transparent polyimide sheet containing fluorine according to claim 1.

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