WO2022137043A1

WO2022137043A1 - Method of forming circuit wiring on glass substrate and glass circuit board

Info

Publication number: WO2022137043A1
Application number: PCT/IB2021/061852
Authority: WO
Inventors: 오병두
Original assignee: 아피오테크 주식회사
Priority date: 2020-12-21
Filing date: 2021-12-16
Publication date: 2022-06-30
Also published as: KR20220089570A

Abstract

A method of forming a glass circuit board comprises the steps of: providing a glass substrate and a metal layer; and laminating the metal layer on the glass substrate by means of an adhesive layer interposed therebetween. The formed circuit board can maintain stable performance without undergoing a degradation process while having excellent thermal characteristics, and can also implement a low-resistance circuit.

Description

【Specification】

[Title of the invention] Method for forming circuit wiring on a glass substrate and a glass circuit board

[Technical Field] The present invention relates to the formation of circuit wiring on a glass substrate, and more particularly, to a method of forming a metal wiring on a substrate made of glass or glass-like material.

[Background Art] A conventional LCD backlight includes an LED on a PCB made of resin, and the LCD backlight can be mounted on the back side of the LCD plate. However, as the LEDs for LCD backlights become smaller (mini-LED) and the board mounting density increases, the amount of current supplied to the LEDs increases and the amount of heat generated may increase. In fact, about 100,000 to 1 million LEDs can be mounted on the LCD backlight. Korean Patent No. 10- 0755615 discloses "a backlight of a liquid crystal display using a light emitting diode", wherein the backlight uses a resin double-sided printed circuit board, and the printed circuit board is connected with a connector for connection contains Since the resin substrate uses the conventional printed circuit board technology, multi-layer circuit wiring is easy, so the LED driving IC can be mounted on the back side of the PCB by using the through hole. However, as mentioned above, as the number and density of LEDs increase, the amount of current used increases and the amount of heat generated increases, so that deformation and bending can easily occur. In addition, due to the poor flatness of the substrate, when viewed from the front of the display, the luminance of the LED may be seen partially, and the luminance deviation between the display tiles , the tile structure may be visually recognized. In addition, due to the dimensional tolerance due to the deformation of the substrate, it may be difficult to mount the mini LED with a small size in an accurate position.

【Detailed Description of the Invention】

[Technical Problem] The present invention provides a glass circuit board with excellent flatness, less mechanical deformation, and improved thermal durability by overcoming the disadvantages of a printed circuit board made of a resin material, which is vulnerable to thermal deformation, and a method for forming the same. The present invention provides a method of forming a circuit board capable of designing elements in a high-density integration using glass or a glass-like material, and a glass circuit board by the method. The present invention uses glass or a glass-like material to have excellent flatness of the circuit board, so that it can be directly bonded to the LCD panel (Opt i cal Bonding). The present invention provides a glass circuit board capable of maintaining stable performance without thermal deformation while having excellent thermal properties and capable of increasing the thickness of metal wiring to implement a low-resistance circuit, and a method for forming the same. The present invention can provide an optimal solution for use as a substrate for a mini LED backlight and as a substrate for a mini LED display.

【Technical solution】 According to an exemplary embodiment of the present invention, the method for forming a glass circuit board includes the steps of providing a glass substrate and a metal layer, and depositing a metal layer on the glass substrate through an adhesive layer interposed therebetween. It is possible to maintain stable performance without a process of deterioration while the circuit board has excellent thermal characteristics, and to implement a circuit with low resistance. have. As an adhesive layer that can be adhered by hot pressing, a metal layer and a glass substrate can be bonded. As an adhesive layer, an adhesive sheet is interposed between a thick metal film and a glass substrate, and the metal layer and glass substrate can be bonded by hot pressing. As the adhesive sheet, a prepreg sheet, a bonding sheet, etc. can be used, and these adhesive sheets and metal layers are supplied in a roll-to-roll method, which is very advantageous for automated processes. After laminating as a thick film on a glass substrate with a metal layer, the metal thick film can be turned to form wiring, but before laminating the metal layer on the glass substrate, a metal thick film is patterned to form a metal layer, It is also possible to deposit the patterned metal layer on the glass substrate. According to an exemplary embodiment of the present invention, the glass circuit board may include a glass substrate, an adhesive layer laminated on the glass substrate, and a metal layer laminated on the glass substrate via the adhesive layer. The adhesive layer can bond the metal layer and the glass substrate by a hot pressing process, and the adhesive layer can be formed using an adhesive sheet capable of hot pressing, for example, a prepreg sheet, a bonding sheet, etc. can be used. The metal layer may be provided in a state in which wiring is formed, or the metal layer may be provided as a metal thick film without wiring. The combination of the adhesive layer and the metal layer may be formed on only one surface of the glass substrate, or may be formed on both surfaces of the glass substrate. In addition, a multi-layer may be formed on one side or both sides of the glass substrate. For this, another adhesive layer and another metal layer may be further formed in the combination of the adhesive layer and the metal layer of the glass substrate to add another adhesive layer and a combination of the metal layer. A via hole may be further formed in the adhesive layer for electrical connection of the metal layer. In this specification, when a 'metal layer' is used, it may be a metal pattern layer on which wiring or other patterning is formed, or a metal thick film that is not patterned.

[Effects of the Invention] Since the glass circuit board of the present invention forms a metal layer on the glass substrate by using an adhesive layer rather than a method such as deposition, plating or printing directly on the glass substrate, a thermally and mechanically stable circuit board is formed. can do. That is, the glass circuit board of the present invention can form a thick metal film on the glass substrate compared to deposition and plating, so the resistance can be lowered, and a high-density metal film can be formed compared to methods such as metal paste printing containing resin, so the resistance can be lowered, and it is possible to prevent bending of the glass substrate due to stress generated during metal film formation such as deposition or plating. That is, the glass circuit board of the present invention can overcome the disadvantages of the printed circuit board made of a resin material, which is vulnerable to thermal deformation, and can form a strong adhesion between glass and metal compared to deposition or plating, so that it is easy to raise a thick metal layer, Compared to a substrate that is deteriorated and brittle such as deposition or plating, the glass circuit board of the present invention does not deteriorate and is not easily broken when handling the substrate, and can maintain excellent flatness. The glass circuit board of the present invention can be used as a mini LED backlight board capable of local dimming or zone dimming, and further can be used as a board module for mounting a high-resolution mini LED display LED and driver IC. Since the glass circuit board of the present invention can form a stable metal layer, it is possible to form the metal wiring as thick as several to several tens of m, and it is possible to implement a low resistance circuit. The adhesive layer or adhesive sheet of the present invention provides an effect of preventing scattering, and since it is easy to handle as much as it is easy to process, it may be advantageous to obtain approval for the safety standard of the final product. Since the present invention uses a glass substrate, when used as a backlight, glass-to-glass bonding (optical bonding or direct bonding) with a glass substrate such as an LCD panel may be possible, and as a result, the thickness of the display may be reduced. The present invention is a mini LED backlight substrate using a glass substrate, and it is possible to effectively implement the optical properties of local dimming to improve the contrast ratio of an LCD display.

[Brief Description of Drawings] Figure 1 is an exploded view of a glass circuit board for explaining a method of forming a glass circuit board according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of the glass circuit board of FIG. 1 . 3 is a cross-sectional view of a glass circuit board according to an embodiment of the present invention. 4 is a view for explaining a method of forming a roll-to-roll type glass circuit board according to an embodiment of the present invention. 5 is a view for explaining a method of forming a glass circuit board according to an embodiment of the present invention. 6 is a cross-sectional view illustrating a glass circuit board having an adhesive layer and a metal layer combination formed on both sides according to an embodiment of the present invention. 7 is a cross-sectional view of a glass circuit board for explaining a combination of an adhesive layer and a metal layer formed in a multi-layer according to an embodiment of the present invention.

[Mode for Implementation of the Invention] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, but the present invention is not limited or limited by the examples. For reference, the same numbers in the present description refer to substantially the same elements, and may be described by citing the contents described in other drawings under these rules, and the contents determined to be obvious to those skilled in the art or repeated may be omitted. Figure 1 is an exploded view of a glass circuit board for explaining a method of forming a glass circuit board according to an embodiment of the present invention, Figure 2 is a cross-sectional view of the glass circuit board of Figure 1, Figure 3 is an embodiment of the present invention It is a cross-sectional view of a glass circuit board according to. 1 to 3 , the glass circuit board according to the present embodiment may include a glass substrate 110 , a metal layer 121 , and an adhesive layer 130 . In order to form this, the glass circuit board forming method provides a glass substrate 110 and a metal layer 121, and the metal layer 121 is laminated on the glass substrate 110 via an adhesive layer 130 interposed therebetween. can be included in the process. Compared to resin substrates, glass substrates have superior thermal properties and It is possible to maintain stable performance without a deterioration process that may occur during the process, and since it is possible to form a relatively thick metal layer 121 , a low resistance circuit may be implemented. As shown, the glass substrate 110, the adhesive layer 130 and the metal layer 121 are laminated, and then these layers can be bonded by hot pressing at about 160 °C or higher. As the adhesive layer 130 , an adhesive sheet such as a prepreg or a bonding sheet may be used. The glass circuit board according to this embodiment is a circuit board that is thermally and mechanically stable, and it can form a strong adhesion between glass and metal, so it is easy to raise a thick metal layer (several to tens of um), and the glass circuit board does not deteriorate, Even when handling the circuit board, it may not break easily. In addition, since the glass substrate 110 is used, high-density, high-current LED mounting is possible, and it can be used as a substrate for a mini LED backlight. It can be usefully applied as a substrate for a mini LED display or a micro LED display. In addition, forming a metal layer by vapor deposition or plating can be considered, but using an adhesive layer, it is possible to form a metal wiring with a thickness of several to tens of m thick, so a low-resistance circuit can be implemented, and the resistance is low. , the line width can be reduced to a minimum, and a high-density circuit can be realized. The adhesive layer or adhesive sheet provides a scattering prevention effect even when the glass circuit board or LCD panel is damaged. have. In addition, since a glass substrate is used, when used as a substrate for backlight, glass-to-glass bonding (optical bonding or direct bonding) with a glass substrate such as an LCD panel may be possible. Referring to FIG. 3 , the metal layer 120 may also be provided as a metal pattern layer obtained by turning a thick metal film. As shown in FIG. 2 , the metal layer 121 may be provided in the form of a metal thick film, but the metal layer 120 may be provided in a patterned state, and the timing at which the pattern is formed may be both before and after bonding. That is, in the present specification, when a 'metal layer' is used, it may be understood as a concept including both a metal pattern layer on which wiring or other patterning is formed, or a non-patterned metal thick film. 4 is a view for explaining a method of forming a glass circuit board of a roll-to-roll method according to an embodiment of the present invention, and FIG. 5 is a view for explaining a method of forming a glass circuit board according to an embodiment of the present invention It is a drawing. For reference, although FIG. 4 is illustrated as being vertically arranged, it may actually be arranged horizontally. Referring to FIG. 4, the glass substrate 110 may be transported through a transport means 140 such as a conveyor, and the transported glass substrate 110 passes through the first roller sets 132 and 136, while the adhesive layer ( 130 ) may be deposited on the glass substrate 110 , and in this process, the adhesive layer 130 of the first release roll paper 134 may be transferred to the glass substrate 110 . In addition, while the glass substrate 110 on which the adhesive layer 130 is deposited passes through the second roller sets 122 and 126, the metal layer 121 may be deposited on the adhesive layer 130 of the glass substrate 110, and this In the process, the metal layer 121 of the second release roll paper 124 may be transferred to the glass substrate 110 . In addition, a copper foil film including a base substrate such as polyimide may be laminated on the adhesive layer as it is. In addition, a hot pressing process may be performed in the process of transferring the metal layer 121 , or alternatively, after completely transferring the metal layer 121 , the second roller set 122 , 126 may be passed and then hot pressing may be performed. have. In FIG. 4, a case in which the metal layer 121 of the metal thick film is transferred onto the glass substrate 110 and the adhesive layer 130 is shown, but as shown in FIG. 5, the metal layer 120 of the metal pattern layer is a second release roll paper ( 124) and it is also possible to transition. In this specification, the case where the adhesive layer and the metal layer are formed on one surface of the glass substrate has been described, but in another embodiment, the adhesive layer and the metal layer may be respectively formed on both sides of the glass substrate, and a plurality of layers (mul) using a combination of the adhesive layer and the metal layer It is also possible to form ti - layers). 6 is a cross-sectional view illustrating a glass circuit board having an adhesive layer and a metal layer combination formed on both sides according to an embodiment of the present invention, and FIG. 7 is an adhesive layer and a metal layer combination formed in a multi-layer according to an embodiment of the present invention. It is a cross-sectional view of a glass circuit board for Referring to FIG. 6 , the adhesive layer 130 and the metal layer 120 may be formed on one surface around the glass substrate 110 , and the other adhesive layer 130 ' and the other metal layer 120 ' may be formed on the other surface. . For this, the above-described forming method or the roll-to-roll method of forming method may be used in the same manner. Referring to FIG. 7 , a multi-layer may be formed on one or both surfaces of the glass substrate 110 . In this embodiment, an adhesive layer 130-2 and an additional adhesive layer 130-2 on the adhesive layer 130 and the metal layer 120 A metal layer 120 - 1 may be further formed. And for electrical connection between the metal layers 120 and 120-1 disposed vertically, a via hole 132-1 may be formed in the adhesive layer 130-1 therebetween, and a plating layer 134 around the via hole 132-1. - 1) may be selectively formed to functionally connect the upper and lower metal layers 120 and 120-1. Through this process, it is possible to implement multi-layers with three or more layers. As described above, although described with reference to preferred embodiments of the present invention, those skilled in the art can variously modify and modify the present invention within the scope without departing from the spirit and scope of the present invention as set forth in the following claims. You will understand that it can be changed.

Claims

【Claim Scope】

[Claim 11 A step of providing a glass substrate and a metal layer; and depositing the metal layer on the glass substrate via an adhesive layer.

[Claim 2] The method for forming a glass circuit board according to claim 1, wherein the metal layer and the glass substrate are laminated via the adhesive layer, and then the metal layer and the glass substrate are bonded together using hot pressing.

[Claim 3] The method according to claim 2, wherein an adhesive sheet is interposed between the metal thick film and the glass substrate as the adhesive layer, and the metal layer and the glass substrate are bonded to each other by hot pressing.

[Claim 4] The method according to claim 3, wherein at least one of the metal sheet and the adhesive sheet is supplied in a roll-to-roll (Rol 1-to-Rol 1) manner.

[Claim 5] The method according to claim 3, The adhesive sheet is a glass circuit board forming method, characterized in that using a prepreg sheet or a bonding sheet.

[Claim 6] The method for forming a glass circuit board according to claim 1, wherein after laminating the metal layer as a thick film on the glass substrate, the metal layer is turned to form a wiring.

[Claim 7] The method of claim 1, wherein before laminating the metal layer on the glass substrate, the metal layer is formed by turning a metal thick film, and laminating the patterned metal layer on the glass substrate A method of forming a glass circuit board, characterized in that

[Claim 8] Glass substrate; an adhesive layer laminated on the glass substrate; and a metal layer laminated on the glass substrate via the adhesive layer.

[Claim 9] The glass circuit board according to claim 8, wherein the adhesive layer is formed by bonding the metal layer to the glass substrate by a hot pressing process.

【Claim 10】 The glass circuit board according to claim 8, wherein the adhesive layer uses a prepreg sheet or a bonding sheet.

[Claim 11] The glass circuit board according to claim 8, wherein the metal layer is provided with wiring formed thereon.

[Claim 1] The glass circuit board according to claim 8, wherein the metal layer is provided as a metal thick film without wiring.

[Claim 13] The glass circuit board according to claim 8, wherein a combination of the adhesive layer and the metal layer is formed on both surfaces of the glass substrate.

[Claim 14] The glass circuit board according to claim 8, wherein the combination of the adhesive layer and the metal layer is formed as a multi-layer on one surface of the glass substrate.