Metal-clad laminate

Abstract

The present invention provides a metal-clad laminate, which includes a liquid crystal polymer film and a first metal layer arranged on the liquid crystal polymer film. The liquid crystal polymer biaxially stretched film that has not been heat-treated and the first metal material are simultaneously subjected to a high-temperature pressing process by a double-belt pressing device to form a liquid crystal polymer film and a first metal layer that are bonded to each other, and the thermal expansion coefficient of the liquid crystal polymer biaxially stretched film that has not been heat-treated in the mechanical direction and the transverse direction is ‑25 to 0 ppm / K. The liquid crystal polymer biaxially stretched film that has not been heat-treated is formed into a liquid crystal polymer film, the first metal material is formed into a first metal layer, and the process temperature of the high-temperature pressing process is greater than or equal to the melting point of the liquid crystal polymer biaxially stretched film that has not been heat-treated.

Description

Technical Field

[0001] The present invention relates to a metal-clad laminate, and in particular to a metal-clad laminate which is easy to manufacture, high in quality and high in yield. Background Art

[0002] With the evolution and development of electronic devices, electronic devices have become indispensable items in today's society. Metal-clad laminates have been widely used in most electronic devices as circuit boards, so the cost, quality and yield of metal-clad laminates directly affect most electronic devices. Therefore, the industry is committed to developing or manufacturing metal-clad laminates with low cost, high quality and high yield.

[0003] In recent years, due to the demand for 5G, in order to improve the reliability of metal-clad laminates in high-frequency areas, the dielectric constant (Dk) and dissipation factor (Df) of the material need to be reduced to achieve signal stability in high-frequency bands or high-speed transmission. Based on this demand, the characteristics of liquid crystal polymers have been verified to meet this demand.

[0004] Since liquid crystal polymers are crystalline, the molecular alignment crystallization produced by the extension of the liquid crystal polymer film will make the thermal expansion coefficient of the material negative. For example, when making a metal-clad laminate using copper foil as the metal layer, since the thermal expansion coefficient of the copper foil is 10-20ppm / K, when the liquid crystal polymer film with a negative thermal expansion coefficient is laminated with the copper foil with a positive thermal expansion coefficient, the metal-clad laminate will warp due to the mismatch of the thermal expansion coefficients. Accordingly, in Taiwan Patent No. I396486, the thermal expansion coefficient of this liquid crystal polymer film is mentioned, making it close to the thermal expansion coefficient of the copper foil. However, the heat treatment required for this liquid crystal polymer film involves a complex control process, and it is difficult to obtain a liquid crystal polymer film with stable quality. Summary of the invention

[0005] One of the purposes of the present invention is to provide a metal-clad laminate, which is formed by a high-temperature pressing process of a liquid crystal polymer biaxially stretched film that has not been heat-treated and a metal material using a double-belt press machine. For a specific liquid crystal polymer film, this process can simultaneously achieve the adjustment of the thermal expansion coefficient and the cladding of a metal layer (e.g., copper foil).

[0006] One embodiment of the present invention provides a metal-clad laminate, which includes a liquid crystal polymer film and a first metal layer, wherein the first metal layer is disposed on the liquid crystal polymer film. A double-belt laminating device is used to simultaneously perform a high-temperature laminating process on a liquid crystal polymer biaxially stretched film that has not been heat-treated and a first metal material to form a liquid crystal polymer film and a first metal layer that are bonded to each other, wherein the thermal expansion coefficient of the liquid crystal polymer biaxially stretched film that has not been heat-treated in the machine direction (MD) is -25 to 0 ppm / K, and the thermal expansion coefficient of the liquid crystal polymer biaxially stretched film that has not been heat-treated in the transverse direction (TD) is -25 to 0 ppm / K. The liquid crystal polymer biaxially stretched film that has not been heat-treated is formed as a liquid crystal polymer film, the first metal material is formed as a first metal layer, and the process temperature of the high-temperature laminating process is greater than or equal to the melting point (melting temperature) of the liquid crystal polymer biaxially stretched film that has not been heat-treated.

[0007] The present invention forms a liquid crystal polymer film and a metal layer bonded to each other by simultaneously performing a high-temperature pressing process on a liquid crystal polymer biaxially stretched film that has not been heat treated and a metal material through a double-belt pressing device, and the process temperature of the high-temperature pressing process is greater than or equal to the melting point of the liquid crystal polymer biaxially stretched film that has not been heat treated. Therefore, the quality and yield of the manufactured metal-clad laminate are high, and the manufacture of the metal-clad laminate is simple. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 FIG. 1 is a schematic cross-sectional view of a metal-clad laminate according to a first embodiment of the present invention.

[0009] Figure 2 FIG. 4 is a schematic diagram of a manufacturing process of a metal-clad laminate according to an embodiment of the present invention.

[0010] Figure 3 FIG. 4 is a schematic diagram of a manufacturing process of a metal-clad laminate according to another embodiment of the present invention.

[0011] Figure 4 FIG. 1 is a schematic cross-sectional view of a metal-clad laminate according to a second embodiment of the present invention.

[0012] Explanation of symbols in the accompanying drawings:

[0013] 100,200:system;

[0014] 102: a biaxially stretched liquid crystal polymer film that has not been heat-treated;

[0015] 104: a first metal material;

[0016] 106: second metal material;

[0017] 110: double belt pressing device;

[0018] 112: annular belt;

[0019] 114: rotating member;

[0020] 116: heater;

[0021] 122, 124, 126: unwinding roller;

[0022] 130: winding roller;

[0023] 212: heating element;

[0024] 214: clamping roller;

[0025] 216: heat treatment machine;

[0026] LCF: liquid crystal polymer film;

[0027] LPR: Pressing length;

[0028] M1: first metal layer;

[0029] M2: second metal layer;

[0030] MCB1, MCB2: Metal-clad laminate;

[0031] PR: Pressing area. DETAILED DESCRIPTION

[0032] In order to enable those skilled in the art to further understand the present invention, some embodiments of the present invention are listed below, and the components of the present invention and the effects to be achieved are described in detail with the accompanying drawings. It should be noted that the drawings are simplified schematic diagrams, and the materials and parameter ranges of key components are described based on current technology. Therefore, only the components and combination relationships related to the present invention are shown to provide a clearer description of the basic architecture, implementation method or operation of the present invention. The actual components and layout may be more complex, and the materials or parameter ranges used may change with the development of future technology. In addition, for the convenience of explanation, the components shown in the various drawings of the present invention may not be drawn in proportion to the actual number, shape, and size, and the details may be adjusted according to the design requirements.

[0033] In the following description and patent application, words such as "include", "contain", "have" are open words, and therefore should be interpreted as "including but not limited to..." Therefore, when the terms "include", "contain" and / or "have" are used in the description of the present invention, they specify the existence of corresponding features, regions, steps, operations and / or components, but do not exclude the existence of one or more corresponding features, regions, steps, operations and / or components.

[0034] It should be understood that in the following description and patent application, when "component B is formed by C", it means that component B is formed with the presence of C or using C, and the formation of component B does not exclude the existence or use of one or more other features, regions, steps, operations and / or components.

[0035] The ordinal numbers used in the specification and the patent application, such as "first", "second", etc., are used to modify components. They do not imply or represent any previous ordinal numbers of the (or those) components, nor do they represent the order of one component and another component, or the order of the manufacturing method. The use of these ordinal numbers is only used to make a component with a certain name clearly distinguishable from another component with the same name. The patent application and the specification may not use the same words. Accordingly, the first component in the specification may be the second component in the patent application.

[0036] It should be noted that the following embodiments can replace, reorganize, or mix features in several different embodiments to complete other embodiments without departing from the spirit of the present invention. The features between the embodiments can be mixed and matched as long as they do not violate the spirit of the invention or conflict with each other.

[0037] Please refer to Figure 1 , Figure 1 FIG. 1 is a schematic cross-sectional view of a metal-clad laminate according to a first embodiment of the present invention. Figure 1 As shown, the metal-clad laminate MCB1 of the present embodiment may include a liquid crystal polymer film LCF, a first metal layer M1 and a second metal layer M2. The first metal layer M1 and the second metal layer M2 may be respectively arranged on different surfaces of the liquid crystal polymer film LCF, so that the liquid crystal polymer film LCF may be located between the first metal layer M1 and the second metal layer M2, but not limited to this.

[0038] The liquid crystal polymer in the liquid crystal polymer film LCF may be polymerized from any suitable material. For example, the liquid crystal polymer may be polymerized from aromatic dihydroxy compounds, aliphatic dihydroxy compounds, aromatic dicarboxylic acids, aliphatic dicarboxylic acids, aromatic hydroxycarboxylic acids, aromatic diamines, aromatic hydroxyamines, aromatic aminocarboxylic acids, other suitable materials or combinations thereof, but the invention is not limited thereto. In the present embodiment, the liquid crystal polymer film LCF may be, for example, a soft insulating film, and therefore, the metal-clad laminate MCB1 including the liquid crystal polymer film LCF may be a soft metal-clad laminate, but the invention is not limited thereto.

[0039] In some embodiments, the liquid crystal polymer film LCF may also have a lower loss factor, for example, the loss factor of the liquid crystal polymer film LCF is 0.002. Therefore, when the metal-clad laminate MCB1 is applied to a circuit board, the signal in the circuit will be reduced in attenuation because the liquid crystal polymer film LCF has a lower loss factor. For example, the metal-clad laminate MCB1 with a liquid crystal polymer film LCF having a lower loss factor may be applied to high-frequency and / or high-speed circuit boards, but is not limited thereto. In addition, the liquid crystal polymer film LCF may also have the advantages of low price and / or low water absorption, so it is beneficial for the metal-clad laminate MCB1 with the liquid crystal polymer film LCF to be applied to circuit boards.

[0040] The thickness of the liquid crystal polymer film LCF may be any suitable thickness. For example, the thickness of the liquid crystal polymer film LCF in some embodiments may be 25 to 125 micrometers, but is not limited thereto. In some embodiments, the melting point of the liquid crystal polymer film LCF may be 250° C. to 350° C. or 278° C. to 325° C., but is not limited thereto.

[0041] The material of the first metal layer M1 and the material of the second metal layer M2 can be any suitable metal, and the material of the first metal layer M1 and the material of the second metal layer M2 can be the same or different. For example, the material of the first metal layer M1 and the second metal layer M2 can both be copper, so that the metal clad laminate MCB1 can be a copper clad laminate (CCL) or a flexible copper clad laminate (FCCL), but is not limited thereto.

[0042] The thickness of the first metal layer M1 and the second metal layer M2 can be designed according to the requirements. For example, the thickness of the first metal layer M1 and the second metal layer M2 can be 9 to 36 micrometers (μm), but not limited thereto. In addition, the centerline average roughness (Ra) of the surface of the first metal layer M1 and the second metal layer M2 can also be designed according to the requirements. For example, the centerline average roughness of the surface of the first metal layer M1 and the second metal layer M2 can be less than or equal to 2 micrometers, but not limited thereto.

[0043] In the metal-clad laminate MCB1 of the present embodiment, the peel strength of the first metal layer M1 to the liquid crystal polymer film LCF and the peel strength of the second metal layer M2 to the liquid crystal polymer film LCF can be designed according to the requirements. For example, the peel strength of the first metal layer M1 and the second metal layer M2 in the machine direction (machine direction, MD) can be greater than or equal to 0.6 Newton / millimeter (N / mm) or greater than or equal to 0.7 Newton / mm, and the peel strength of the first metal layer M1 and the second metal layer M2 in the transverse direction (transverse direction, TD) can be greater than or equal to 0.6 Newton / mm or greater than or equal to 0.7 Newton / mm, but not limited thereto. In the metal-clad laminate MCB1 with this design, the first metal layer M1 and the second metal layer M2 are less likely to peel off during use.

[0044] In the metal-clad laminate MCB1, the tensile strength of the liquid crystal polymer film LCF in MD and TD can be designed according to the requirements. In the present embodiment, the liquid crystal polymer film LCF can be made of a liquid crystal polymer biaxially stretched film (details will be described below), so the liquid crystal polymer film LCF has a sufficiently strong tensile strength in MD and TD, and can ensure that the liquid crystal polymer film LCF has similar mechanical properties in MD and TD. For example, the tensile strength of the liquid crystal polymer film LCF in MD can be greater than or equal to 80 megapascals (MPa), or greater than or equal to 100 MPa, and the tensile strength of the liquid crystal polymer film LCF in TD can be greater than or equal to 80 MPa, or greater than or equal to 100 MPa, but not limited thereto. In this case, according to the design of the tensile strength in MD and TD, the liquid crystal polymer film LCF is less likely to be damaged due to stretching during use. It should be noted that, in the present invention, the tensile strength of the liquid crystal polymer film LCF in MD and TD is measured after the first metal layer M1 and the second metal layer M2 are completely removed (for example, removed by an etching process).

[0045] In the metal-clad laminate MCB1, the thermal expansion coefficient of the liquid crystal polymer film LCF in MD and TD can be designed according to the requirements. For example, in some embodiments, the thermal expansion coefficient of the liquid crystal polymer film LCF in MD can be greater than 0ppm / K, and the thermal expansion coefficient of the liquid crystal polymer film LCF in TD can be greater than 0ppm / K, but it is not limited to this. In addition, in some embodiments, the thermal expansion coefficient of the liquid crystal polymer film LCF in MD and TD can preferably be similar to the thermal expansion coefficient of the first metal layer M1 and / or the second metal layer M2 in MD and TD (for example, but not limited to, 16 to 18ppm / K) to improve the quality of the formed metal-clad laminate MCB1. It should be noted that in the present invention, the thermal expansion coefficient of the liquid crystal polymer film LCF in MD and TD is measured after the first metal layer M1 and the second metal layer M2 are completely removed (for example, removed by an etching process). It should be noted that in the present invention, the thermal expansion coefficient is the dimensional change rate of the measured object at a temperature between 30°C and 200°C.

[0046] In the metal-clad laminate MCB1, the elongation of the liquid crystal polymer film LCF in MD and TD can be designed according to the requirements. For example, in some embodiments, the elongation of the liquid crystal polymer film LCF in MD can be greater than 10%, and the elongation of the liquid crystal polymer film LCF in TD can be greater than 10%, but it is not limited to this. It should be noted that in the present invention, the elongation of the liquid crystal polymer film LCF in MD and TD is measured after the first metal layer M1 and the second metal layer M2 are completely removed (for example, removed by an etching process).

[0047] In the metal-clad laminate MCB1, the Young's modulus of the liquid crystal polymer film LCF in MD and TD can be designed according to the requirements. For example, in some embodiments, the Young's modulus of the liquid crystal polymer film LCF in MD can be 2 to 4 GPa, and the Young's modulus of the liquid crystal polymer film LCF in TD can be 2 to 4 GPa, but it is not limited thereto. In the present invention, the Young's modulus of the liquid crystal polymer film LCF in MD and TD is measured after the first metal layer M1 and the second metal layer M2 are completely removed (for example, removed by an etching process).

[0048] In addition, the liquid crystal polymer film LCF in the metal-clad laminate MCB1 needs to have good dimensional stability so that the metal-clad laminate MCB1 has good quality; and if the dimensional stability of the liquid crystal polymer film LCF is not good, the liquid crystal polymer film LCF cannot be applied to products such as copper foil laminates and soft copper foil laminates. The present invention evaluates the dimensional stability of the liquid crystal polymer film LCF in MD and TD using the 2.2.4 test method of IPC-TM-650, wherein the 2.2.4 test method of IPC-TM-650 includes methods A, B and C, and the present invention evaluates the dimensional stability of the liquid crystal polymer film LCF in MD and TD using methods B and C, but is not limited thereto. For example, the dimensional stability in MD and TD is evaluated separately, and the dimensional stability is evaluated based on the difference between the linear dimensional change rates of the liquid crystal polymer film LCF measured in methods B and C (for example, the absolute value of the difference in the linear dimensional change rate may be less than or equal to 1%), but is not limited thereto.

[0049] The following will explain Figure 1 The method for manufacturing the metal-clad laminate board MCB1 is shown, but the method for manufacturing the metal-clad laminate board MCB1 is not limited to the following.

[0050] Please refer to Figure 2 , and also refer to Figure 1 , Figure 2 FIG. 1 is a schematic diagram of a manufacturing process of a metal-clad laminate according to an embodiment of the present invention. Figure 2 The system 100 for manufacturing the metal-clad laminate MCB1 is illustrated as a roll-to-roll system, but is not limited thereto. The system 100 for manufacturing the metal-clad laminate MCB1 can be any suitable system according to the requirements. Figure 1 and Figure 2 As shown, the system 100 can simultaneously perform a high temperature pressing process on the unheat-treated liquid crystal polymer biaxially stretched film 102, the first metal material 104 and the second metal material 106 to form a liquid crystal polymer film LCF, a first metal layer M1 and a second metal layer M2 that are bonded to each other, thereby forming a metal-clad laminate MCB1, wherein the unheat-treated liquid crystal polymer biaxially stretched film 102 is formed as a liquid crystal polymer film LCF, the first metal material 104 is formed as the first metal layer M1, and the second metal material 106 is formed as the second metal layer M2. It should be noted that whether the first metal material 104 and the second metal material 106 are the same or not depends on whether the material of the first metal layer M1 and the material of the second metal layer M2 are the same. Therefore, if the material of the first metal layer M1 and the material of the second metal layer M2 are both copper, then the first metal material 104 and the second metal material 106 are the same and are both copper.

[0051] The unheat-treated biaxially stretched liquid crystal polymer film 102 can be formed by any suitable molding method, and the film is not heat-treated after molding. Therefore, the unheat-treated biaxially stretched liquid crystal polymer film 102 has some parameters that are significantly different from those of the heat-treated biaxially stretched film. In some embodiments, the unheat-treated biaxially stretched liquid crystal polymer film 102 may have a lower coefficient of thermal expansion than the heat-treated biaxially stretched film. For example, the coefficient of thermal expansion of the unheat-treated biaxially stretched liquid crystal polymer film 102 in MD may be -25 to 0 ppm / K, and the coefficient of thermal expansion of the unheat-treated biaxially stretched liquid crystal polymer film 102 in TD may be -25 to 0 ppm / K, but not limited thereto. In some embodiments, the unheat-treated biaxially stretched liquid crystal polymer film 102 may have a higher tensile strength than the heat-treated biaxially stretched film. For example, the tensile strength of the unheat-treated biaxially stretched LCP film 102 in MD may be greater than or equal to 300 MPa, and the tensile strength of the unheat-treated biaxially stretched LCP film 102 in TD may be greater than or equal to 300 MPa, but the present invention is not limited thereto.

[0052] In addition, the melting point of the unheated liquid crystal polymer biaxially stretched film 102 can be 250°C to 350°C or 278°C to 325°C, but not limited thereto. In addition, the thickness of the unheated liquid crystal polymer biaxially stretched film 102 can be selected according to the requirements. For example, the thickness of the unheated liquid crystal polymer biaxially stretched film 102 can be 25 to 125 microns, but not limited thereto. The elongation and Young's modulus of the unheated liquid crystal polymer biaxially stretched film 102 can be selected according to the requirements. For example, the elongation of the unheated liquid crystal polymer biaxially stretched film 102 can be 1% to 10% in MD and TD, and the Young's modulus of the unheated liquid crystal polymer biaxially stretched film 102 can be 5 to 10 GPa in MD and TD, but not limited thereto.

[0053] exist Figure 2 In the roll-to-roll system 100 shown, the system 100 may include a double-belt press machine 110, a plurality of unwinding rollers 122, 124, 126, and a winding roller 130. The unwinding rollers 122, 124, 126 are respectively mounted with a roll of a liquid crystal polymer biaxially stretched film 102 that has not been heat-treated, a roll of a first metal material 104, and a roll of a second metal material 106, and the unwinding rollers 122, 124, 126 rotate to simultaneously deliver the liquid crystal polymer biaxially stretched film 102 that has not been heat-treated, the first metal material 104, and the second metal material 106 to the double-belt press machine 110.

[0054] This system 100 may also optionally include a winding roller (not shown) installed with a first insulating material in a roll shape and a winding roller (not shown) installed with a second insulating material in a roll shape, wherein the unheat-treated liquid crystal polymer biaxially stretched film 102, the first metal material 104, the second metal material 106, the first insulating material and the second insulating material are simultaneously conveyed to the double-belt pressing device 110.

[0055] The double-belt pressing device 110 is used to perform a high-temperature pressing process on the input raw materials to obtain a multi-layer structure that is bonded to each other, wherein the high-temperature pressing process includes a pressing process and a heat treatment process. In the present embodiment, the double-belt pressing device 110 may include a plurality of (e.g., two) annular belts 112, a plurality of rotating parts 114, and at least one heater 116. The two annular belts 112 are arranged adjacent to each other, and a pressing area PR is formed between the two annular belts 112, and the raw materials input into the double-belt pressing device 110 are transported to the pressing area PR between the two annular belts 112, so that the annular belts 112 can perform a pressing process and press the raw materials in the pressing area PR. Each annular belt 112 can surround at least two rotating parts 114, so that the annular belt 112 can rotate with the rotation of the rotating parts 114 to perform pressing and conveying at the same time. It should be noted that in Figure 2 In the laminating area PR, the laminating area PR is located between the centers of the two rotating members 114. Therefore, the annular belt 112 of the double-belt laminating device 110 can continuously perform the laminating process in the laminating area PR (i.e., continuously laminating the raw materials between the two annular belts 112) to increase the laminating process time and improve the laminating effect.

[0056] The heater 116 may be disposed between the two rotating members 114 so that the heater 116 can perform a heat treatment process to heat treat the raw materials in the pressing area PR. In this embodiment, the heater 116 may be disposed on both sides of the pressing area PR to uniformly heat treat the raw materials in the pressing area PR, but the present invention is not limited thereto. Figure 2 The use of the double-belt pressing device 110 allows the pressing process and the heat treatment process in the high-temperature pressing process to be performed simultaneously.

[0057] like Figure 2As shown, during the manufacturing process of the metal-clad laminate MCB1, when the unheat-treated liquid crystal polymer biaxially stretched film 102, the first metal material 104 and the second metal material 106 are simultaneously input into the pressing area PR of the double-belt pressing device 110 (the unheat-treated liquid crystal polymer biaxially stretched film 102 is between the first metal material 104 and the second metal material 106), the metal-clad laminate MCB1 can be formed by the double-belt pressing device 110. The double-belt pressing device performs a high-temperature pressing process on the unheat-treated liquid crystal polymer biaxially stretched film 102, the first metal material 104 and the second metal material 106 located in the pressing area PR to form a liquid crystal polymer film LCF, a first metal layer M1 and a second metal layer M2 that are bonded to each other, so as to produce a product as shown in FIG. Figure 1 The metal-clad laminate board MCB1 is shown.

[0058] Optionally, the first insulating material and the second insulating material may be additionally input into the lamination area PR of the double-belt lamination device 110, so that the first metal material 104 is located between the first insulating material and the unheat-treated liquid crystal polymer biaxially stretched film 102, and the second metal material 106 is located between the second insulating material and the unheat-treated liquid crystal polymer biaxially stretched film 102. After the high-temperature lamination process, the first insulating material may be formed into a first insulating layer (or called a first release layer), and the second insulating material may be formed into a second insulating layer (or called a second release layer), so that the first metal layer M1 is located between the first insulating layer and the liquid crystal polymer film LCF, and the second metal layer M2 is located between the second insulating layer and the liquid crystal polymer film LCF. Afterwards, the first insulating layer and the second insulating layer may be removed (e.g., torn off) at an appropriate time to form Figure 1 The metal-clad laminate MCB1 is shown.

[0059] In the high temperature pressing process, the process temperature may be greater than or equal to the melting point of the liquid crystal polymer biaxially stretched film 102 that has not been heat treated. For example, the process temperature of the high temperature pressing process may be greater than or equal to 278°C, greater than or equal to 284°C, or greater than or equal to 325°C, but is not limited thereto. In some embodiments, if the melting point of the liquid crystal polymer biaxially stretched film 102 that has not been heat treated is represented by Tm, the process temperature of the high temperature pressing process may be greater than or equal to Tm and less than or equal to Tm+40°C. For example, the process temperature of the high temperature pressing process may be greater than or equal to 278°C and less than or equal to 318°C, greater than or equal to 284°C and less than or equal to 324°C, or greater than or equal to 325°C and less than or equal to 365°C, but is not limited thereto.

[0060] In the high-temperature pressing process of the double-belt pressing device 110, the pressing pressure, pressing time (i.e., the time from the start of pressing to the end of pressing at a reference point) and pressing length LPR (i.e., the length of the pressing area PR, the length between the centers of the two rotating parts 114) of the pressing process can be designed according to requirements. For example, in some embodiments, the pressing pressure of the high-temperature pressing process may be 10 to 50 bar (for example, 20 bar, i.e., 2MPa), but is not limited thereto. It should be noted that if the pressure is lower than 10 bar, there will be problems with incomplete pressing, and if the pressure is higher than 50 bar, glue overflow is likely to occur. For example, in some embodiments, the pressing time of the high-temperature pressing process may be 30 to 360 seconds, preferably 90 to 180 seconds, but is not limited thereto. It should be noted that in Figure 2 In the embodiment, since the heater 116 can be disposed between the two rotating members 114, the heat treatment time of the high temperature pressing process (i.e., the time from the start of the heat treatment to the end of the heat treatment at a reference point) can be less than or equal to the pressing time. In other words, Figure 2 The laminating time of the high temperature laminating process of the double belt laminating device 110 shown can be regarded as the total process time of the high temperature laminating process, but is not limited thereto. For example, in some embodiments, in the high temperature laminating process, the laminating length LPR of the double belt laminating device 110 on the unheat-treated biaxially stretched liquid crystal polymer film 102 in the MD can be greater than or equal to 0.5 meters, or greater than or equal to 1 meter, but is not limited thereto.

[0061] Since the double-belt pressing device 110 used in this embodiment can perform the pressing process and the heat treatment process of the high-temperature pressing process simultaneously, in addition to simplifying the process (i.e., there is no need to use different equipment to separately perform the pressing process and the heat treatment process), the quality of the manufactured metal-clad laminate MCB1 can also be improved.

[0062] In detail, the lamination process needs to be performed at a high temperature to achieve a good lamination effect and to enhance the bonding strength between the metal and the liquid crystal polymer film LCF, while the heat treatment process is used to adjust the thermal expansion coefficient and / or mechanical properties of the liquid crystal polymer film LCF. Therefore, if the lamination process and the heat treatment process are performed separately by different equipment, more than two heating processes are required (both the lamination process and the heat treatment process require heating). In this embodiment, since the double-belt lamination device 110 can perform the lamination process and the heat treatment process of the high-temperature lamination process simultaneously, only one heating process is required to complete the lamination process and the heat treatment process.

[0063] In addition, since the double-belt laminating device 110 of the present embodiment can simultaneously perform the laminating process and the heat treatment process of the high-temperature laminating process, the laminating time is longer and the laminating area of ​​the double-belt laminating device 110 is also larger (i.e., the double-belt laminating device 110 has a longer laminating length LPR), so that the dimensional stability of the metal-clad laminate MCB1 manufactured by the double-belt laminating device 110 is higher (the dimensional stability of the liquid crystal polymer film LCF is higher). For example, in the liquid crystal polymer film LCF of the metal-clad laminate MCB1 manufactured by the double-belt laminating device 110 of the present embodiment, the absolute value of the difference between the linear dimensional change rate measured in method B and the linear dimensional change rate measured in method C can be less than or equal to 1%.

[0064] After the high temperature lamination process is completed, the metal-clad laminate MCB1 output from the double-belt lamination device 110 may be rolled into a roll by the winding roller 130 to complete the manufacture of the metal-clad laminate MCB1.

[0065] Please refer to Figure 3 , and also refer to Figure 1 , Figure 3 FIG. 1 is a schematic diagram of a manufacturing process of a metal-clad laminate according to another embodiment of the present invention. Figure 3 The system 200 for manufacturing the metal-clad laminate MCB1 is illustrated as a roll-to-roll system, but the invention is not limited thereto. The system 200 for manufacturing the metal-clad laminate MCB1 can be any suitable system according to the requirements. Figure 2 The difference between the system 100 shown in FIG. 1 is that the system 200 of the present embodiment converts Figure 2 The double-belt laminating device 110 shown is replaced with other equipment, so that the laminating process and the heat treatment process are performed by different equipment, that is, the laminating process and the heat treatment process of this embodiment are not performed at the same time. Figure 3 In the lamination process, the lamination is completed by heating with a heating element 212 (e.g., a heating roller) and lamination with a clamping roller 214, wherein the system 200 of this embodiment may use a device including both a heating element 212 and a clamping roller 214 to perform the lamination process, or the system 200 of this embodiment may use two devices including a heating element 212 and a clamping roller 214 to perform the lamination process. For example, the device used for lamination in the system 200 of this embodiment may include a roller press having at least a clamping roller 214, but is not limited thereto. Figure 3 In the embodiment, the heat treatment process is performed by a heat treatment machine 216 .

[0066] In this embodiment, the temperature and the pressing pressure of the pressing process can be designed according to requirements, and the heat treatment temperature and the heat treatment time of the heat treatment process can also be designed according to requirements.

[0067] It should be noted that in Figure 3 In the present invention, since the lamination process is performed by the clamping roller 214, and the lamination length of the clamping roller 214 (i.e., the length of the lamination zone) is very short, which may be less than 10 mm, or only 0.5 to 3 mm, Figure 3 In addition to being unable to simultaneously perform the lamination process and the heat treatment process, the system 200 is also different from the metal-clad laminate MCB1 manufactured by the double-belt lamination device 110. Figure 3 The dimensional stability of the metal-clad laminate MCB1 produced by the system 200 is relatively poor (the dimensional stability of the liquid crystal polymer film LCF is relatively poor). Figure 3 In the system 200, since the pressing process and the heat treatment process must be heated separately, the manufacturing process of the metal-clad laminate MCB1 must be heated more than twice.

[0068] Please refer to Figure 4 , Figure 4 FIG. 2 is a schematic cross-sectional view of a metal-clad laminate according to a second embodiment of the present invention. Figure 4 As shown, the difference between this embodiment and the first embodiment is that the metal-clad laminate board MCB2 of this embodiment does not have the second metal layer M2 , that is, the metal-clad laminate board MCB2 of this embodiment includes a liquid crystal polymer film LCF and a first metal layer M1 .

[0069] In the method for manufacturing the metal-clad laminate MCB2 of the present embodiment, Figure 2 For example, the system 100 can use a double-belt laminating device 110 to simultaneously perform a high-temperature laminating process on the unheat-treated liquid crystal polymer biaxially stretched film 102 and the first metal material 104 to form a liquid crystal polymer film LCF and a first metal layer M1 that are bonded to each other, thereby forming Figure 4 In the metal-clad laminate MCB2 shown, a liquid crystal polymer biaxially stretched film 102 that has not been heat-treated is formed as a liquid crystal polymer film LCF, and a first metal material 104 is formed as a first metal layer M1.

[0070] In addition, the system 100 may also optionally include a roll-out roller (not shown) equipped with a roll-shaped first insulating material and a roll-out roller (not shown) equipped with a roll-shaped second insulating material, wherein the unheat-treated liquid crystal polymer biaxially stretched film 102, the first metal material 104, the first insulating material and the second insulating material are simultaneously conveyed to the double-belt pressing device 110 to form a liquid crystal polymer film LCF, a first metal layer M1, a first insulating layer (or a first release layer) and a second insulating layer (or a second release layer), respectively, wherein the first metal layer M1 is located between the first insulating layer and the liquid crystal polymer film LCF, and the liquid crystal polymer film LCF is located between the second insulating layer and the first metal layer M1. Afterwards, the first insulating layer and the second insulating layer can be removed (e.g., torn off) at an appropriate time to form Figure 4 The metal clad laminate MCB2 is shown. In some embodiments, the second insulating layer may be a high temperature resistant release layer, but is not limited thereto.

[0071] The following will describe in detail the various properties of the unheat-treated liquid crystal polymer films (unheat-treated liquid crystal polymer biaxially stretched film 102, unheat-treated liquid crystal polymer uniaxially stretched film) used in the examples and comparative examples of the metal-clad laminate, the high-temperature pressing process conditions, and the various properties of the metal-clad laminate. Figure 1 Take the metal-clad laminate MCB1 of the present invention as an example, and the materials of the first metal layer M1 and the second metal layer M2 are both copper, but the present invention is not limited thereto. It should be noted that, unless otherwise specified, the materials used in the present invention are conventional materials or the materials described above. It should be noted that the metal-clad laminate MCB1 of the present invention is not limited to the examples given below.

[0072] Example 1 and Example 2 use the same unheat-treated liquid crystal polymer biaxially stretched film 102, and perform a high-temperature lamination process using a double-belt lamination device 110 to form a metal-clad laminate MCB1 including a liquid crystal polymer film LCF, a first metal layer M1, and a second metal layer M2, and various properties of the metal-clad laminate MCB1 of Example 1 and Example 2 are shown in Table 1. It should be noted that the difference between Example 1 and Example 2 lies in the process temperature of the high-temperature lamination process, wherein the process temperature of Example 1 is 300°C, and the process temperature of Example 2 is 325°C.

[0073] Comparative Examples 1 and 2 use the same unheat-treated uniaxially stretched liquid crystal polymer film (for example, one of the tensile strengths in MD and TD may be greater than 300 MPa, and the other may be less than 300 MPa or less than 100 MPa. In the following, the tensile strength in MD may be greater than the tensile strength in TD), and perform a high-temperature lamination process using a double-belt lamination device 110 to form a metal-clad laminate including a liquid crystal polymer film, a first metal layer, and a second metal layer, and various properties of the metal-clad laminates of Comparative Examples 1 and 2 are shown in Table 1. It should be noted that the difference between Comparative Examples 1 and 2 lies in the process temperature of the high-temperature lamination process, wherein the process temperature of Comparative Example 1 is 300° C., and the process temperature of Comparative Example 2 is 325° C.

[0074] [Table 1] High temperature pressing process temperature and various properties of metal-clad laminates of Examples 1 and 2 of the present invention and Comparative Examples 1 and 2

[0075]

[0076]

[0077] As can be seen from Table 1, if a liquid crystal polymer uniaxially stretched film that has not been heat-treated is used to form a liquid crystal polymer film, the formed liquid crystal polymer film has a low tensile strength in MD and / or TD. For example, in Comparative Examples 1 and 2 of Table 1, the liquid crystal polymer uniaxially stretched film that has not been heat-treated has a low tensile strength in TD (e.g., less than 300 MPa or less than 100 MPa), and therefore, the liquid crystal polymer film of the metal-clad laminate of Comparative Examples 1 and 2 also has a low tensile strength in TD (e.g., less than 100 MPa or less than 80 MPa), so that the liquid crystal polymer film may be damaged due to stretching in TD during use. Accordingly, the quality of Comparative Examples 1 and 2 is inferior to that of Examples 1 and 2, and / or Comparative Examples 1 and 2 cannot be used in some cases.

[0078] Examples 3 to 4 and Comparative Examples 3 to 4 use the same unheat-treated liquid crystal polymer biaxially stretched film 102 and perform a high-temperature pressing process using a double-belt pressing device 110 to form a metal-clad laminate MCB1 comprising a liquid crystal polymer film LCF, a first metal layer M1 and a second metal layer M2. The various properties of the metal-clad laminate MCB1 of Examples 3 to 4 and Comparative Examples 3 to 4 are shown in Table 2.

[0079] [Table 2] High temperature pressing process temperature and various properties of metal-clad laminates in Examples 3 to 4 of the present invention and Comparative Examples 3 to 4

[0080]

[0081]

[0082] As can be seen from Table 2, since the process temperature of Comparative Examples 3 and 4 is lower than the melting point of the unheat-treated liquid crystal polymer biaxially stretched film, the thermal expansion coefficient of the liquid crystal polymer film of Comparative Examples 3 and 4 is less than 0 ppm / K, and the peel strength of the first metal layer and the second metal layer is less than 0.6 N / mm. Therefore, the quality of Comparative Examples 3 and 4 is inferior to that of Examples 3 to 4, and Comparative Examples 3 and 4 cannot even be regarded as good products.

[0083] In summary, the present invention forms a liquid crystal polymer film and a metal layer bonded to each other by simultaneously performing a high-temperature pressing process on a liquid crystal polymer biaxially stretched film that has not been heat treated and a metal material through a double-belt pressing device, and the process temperature of the high-temperature pressing process is greater than or equal to the melting point of the liquid crystal polymer biaxially stretched film that has not been heat treated. Therefore, the quality and yield of the manufactured metal-clad laminate are high, and the manufacture of the metal-clad laminate is simple.

[0084] The above description is only a preferred embodiment of the present invention. All equivalent changes and modifications made according to the scope of the patent application of the present invention should fall within the scope of the present invention.

Claims

1. A metal-clad laminate, characterized in that: include: a liquid crystal polymer film; and a first metal layer disposed on the liquid crystal polymer film; wherein a high temperature pressing process is simultaneously performed on a liquid crystal polymer biaxially stretched film that has not been heat-treated and a first metal material by a double-belt pressing device to form the liquid crystal polymer film and the first metal layer that are bonded to each other, the thermal expansion coefficient of the liquid crystal polymer biaxially stretched film that has not been heat-treated in the mechanical direction is -25 to 0 ppm / K, and the thermal expansion coefficient of the liquid crystal polymer biaxially stretched film that has not been heat-treated in the transverse direction is -25 to 0 ppm / K, the tensile strength of the liquid crystal polymer biaxially stretched film that has not been heat-treated in the mechanical direction is greater than or equal to 300 megapascals, and the tensile strength of the liquid crystal polymer biaxially stretched film that has not been heat-treated in the transverse direction is greater than or equal to 300 megapascals; The unheat-treated biaxially stretched liquid crystal polymer film is formed as the liquid crystal polymer film, the first metal material is formed as the first metal layer, and the process temperature of the high-temperature pressing process is greater than or equal to the melting point of the unheat-treated biaxially stretched liquid crystal polymer film.

2. The metal-clad laminate according to claim 1, wherein: It also includes a second metal layer, and the liquid crystal polymer film is located between the first metal layer and the second metal layer, wherein the double-belt pressing device simultaneously performs the high-temperature pressing process on the unheat-treated liquid crystal polymer biaxially stretched film, the first metal material and a second metal material to form the liquid crystal polymer film, the first metal layer and the second metal layer that are bonded to each other, and the second metal material forms the second metal layer.

3. The metal-clad laminate according to claim 2, wherein: The first metal material is the same as the second metal material.

4. The metal-clad laminate according to claim 1, wherein: The first metal material is copper.

5. The metal-clad laminate according to claim 1, wherein: The melting point of the biaxially stretched liquid crystal polymer film that has not been heat-treated is 278° C. to 325° C.

6. The metal-clad laminate according to claim 1, wherein: The thickness of the biaxially stretched liquid crystal polymer film that has not been heat-treated is 25 to 125 micrometers.

7. The metal-clad laminate according to claim 1, wherein: The melting point of the biaxially stretched liquid crystal polymer film that has not been heat-treated is represented by Tm, and the process temperature of the high-temperature pressing process is greater than or equal to Tm and less than or equal to Tm+40°C.

8. The metal-clad laminate according to claim 1, wherein: The high temperature pressing process includes a pressing process and a heat treatment process, and the pressing process and the heat treatment process are performed simultaneously.

9. The metal-clad laminate according to claim 1, wherein: In the high temperature lamination process, the lamination length of the double belt lamination device on the unheat-treated biaxially stretched liquid crystal polymer film in the machine direction is greater than or equal to 0.5 meters.

10. The metal-clad laminate according to claim 1, wherein: The thickness of the first metal layer is 9 to 36 micrometers.

11. The metal-clad laminate according to claim 1, wherein: The centerline average roughness of the surface of the first metal layer is less than or equal to 2 micrometers.

12. The metal-clad laminate according to claim 1, wherein: The peel strength of the first metal layer in the mechanical direction is greater than or equal to 0.6 Newton / mm, and the peel strength of the first metal layer in the transverse direction is greater than or equal to 0.6 Newton / mm.

13. The metal-clad laminate according to claim 1, wherein: The tensile strength of the liquid crystal polymer film in the machine direction is greater than or equal to 80 megapascals, and the tensile strength of the liquid crystal polymer film in the transverse direction is greater than or equal to 80 megapascals.

14. The metal-clad laminate according to claim 1, wherein: The thermal expansion coefficient of the liquid crystal polymer film in the machine direction is greater than 0 ppm / K, and the thermal expansion coefficient of the liquid crystal polymer film in the transverse direction is greater than 0 ppm / K.

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