TW202007526A - High-frequency copper clad laminate and methods thereof - Google Patents

Abstract

The present invention provides a high-frequency copper clad laminate comprising: a copper layer, a dielectric layer and a core layer, wherein the core layer is disposed between the core layer and the dielectric layer, and the core layer is a liquid-crystal polymer core layer. With the high dielectric constant (Dk) and low dissipation factor (Df) of the liquid-crystal polymer core layer and the dielectric layer, the high-frequency copper clad laminate of the invention possesses excellent high- speed transmittance, low performance of loss, high Dk and low Df, low roughness, low water absorption, low resilience which is suitable for high density assembly, great ability of UV laser drilling and excellent mechanical properties. In addition, the present invention further provides a method of preparing the high-frequency copper foil substrate.

Description

High-frequency copper foil substrate and its manufacturing method

The present invention relates to the field of flexible printed circuit board (FPC) and its preparation technology, in particular to a high-frequency high-transmission substrate and its preparation method.

With the rapid development of information technology, wireless communication has become a necessity of life. The wireless communication system is composed of transmitting, receiving, and antenna. The antenna is responsible for the conversion of electromagnetic energy in the circuit and the air, and it is an indispensable basic equipment for the communication system. In antenna-related circuit design, sometimes passive components such as capacitors or inductors are used to match the antenna. With the development of electronic products toward thin, thin, flexible and high-frequency high-speed signal transmission, the active and passive components of related designs must be increased, and the density of circuits and components is bound to increase, causing problems such as electromagnetic interference, increased noise and reduced reliability. . To solve this problem, it is necessary to improve the integration of passive components such as capacitors. Buried capacitors can reduce circuit board area, improve device density and product reliability. Therefore, the development of substrate materials with high dielectric constant and low dielectric loss is an important issue in this field.

At present, high-frequency plates for printed circuit boards (PCB) are commercially available.

1. Add metal powder to the next layer to obtain a dielectric constant (Dk) value of more than 45, but at the same time the dielectric loss factor (Df) value also increases, which cannot really meet the needs of high frequency and high speed, and Such materials are prone to high leakage current in practical applications, which greatly reduces their applicability.

2. Only pure high-content, high-dielectric ceramic powder is added to the epoxy resin, but the ceramic powder dispersed in the epoxy resin is polarized due to its irregular dipole arrangement. Offset, which leads to a relatively limited increase in the dielectric constant value. In addition, due to the excessively high powder content, the mechanical strength of the substrate is reduced, and the adhesion between copper foils is also greatly reduced.

In the field of high-frequency high-speed materials used in flexible circuit board (FPC) processes, the high-frequency plates commonly used in the industry are liquid crystal polymer (LCP) boards and polytetrafluoroethylene (PTFE) substrates. The current PTFE substrate uses a hard board, which has the disadvantage of insufficient flexibility; in terms of electrical properties, when the thickness of the PTFE substrate is 6 mils (mil), its Dk value is 8.0; when its thickness is 20 mils The Dk value is 10; the Dk value of the impregnated glass fiber cloth contained in the PTFE substrate stack is not high, so it is difficult to achieve a Dk value of more than 10, and it is more difficult to produce a thickness of 2 to 6 mils High Dk substrate. The LCP maintains a constant dielectric constant in the radio frequency range up to 110GHz, and the dielectric loss factor is only 0.002, and the thermal expansion coefficient is small, which can realize high-frequency high-speed flexible circuit boards under the premise of higher reliability. However, the Dk value of general LCP is 2.9 to 3.3, which is not enough to meet the demand of high Dk value.

For example, in China Patent No. 201590948U, Taiwan Patent No. M377823, Japanese Patent No. 2010-7418A, and US Patent No. 2011/0114371, composite substrates with excellent workability, low cost, and low energy consumption are proposed. In the Chinese patent No. 202276545U, the Chinese patent No. 103096612B, the Taiwan patent No. M422159 and the Taiwan patent No. M531056, high-frequency substrates are made of fluorine-based materials. Chinese Patent No. 205105448U proposes a composite stacked high-frequency low-dielectric adhesive film, Chinese Patent No. 205255668U proposes a low-dielectric performance adhesive film, and Chinese Patent No. 105295753B proposes a high-frequency adhesive glue layer structure and its preparation Method, Chinese Patent No. 206490891U proposes a low dielectric loss single-sided copper clad substrate (FRCC) with a composite stacked structure. Taiwan Patent No. 098124978 discloses a capacitor substrate structure; Chinese Patent No. 206490897U proposes a FRCC substrate with high heat dissipation efficiency. Chinese Patent No. 206932462U proposes a composite liquid crystal polymer (LCP) high-frequency high-speed FRCC substrate. However, the above patents are still only high-frequency substrate materials with Dk values between 2.0 and 3.5, and cannot meet the demand for high Dk values with Dk values higher than 8.0.

In order to meet the market demand for high-frequency and high-speed flexible sheets, the liquid crystal polymer high-frequency copper foil substrate provided by the present invention uses a liquid crystal polymer core layer and a dielectric with high dielectric constant and low dielectric loss factor characteristics. The glue layer makes the liquid crystal polymer high-frequency copper foil substrate have excellent high-speed transmission, low loss, high Dk and low Df performance, low roughness, low water absorption, and low rebound suitable for high-density assembly Power, good UV laser drilling ability and excellent mechanical properties are superior to ordinary liquid crystal polymer films and polyimide (PI) type adhesive sheets, suitable for wearable devices such as 5G smart phones and electronic watches.

In order to solve the above technical problems, the present invention provides a high-frequency copper foil substrate comprising: a copper foil layer with a thickness of 1 to 35 microns ( μm ); a dielectric constant (Dk) value of 6 to 100 and dielectric loss A dielectric adhesive layer with a factor (Df) value of 0.002 to 0.010, wherein the thickness of the dielectric adhesive layer is 12 to 100 microns; and a core layer with a Dk value of 6 to 100 and a Df value of 0.002 to 0.010, where The core layer is located between the dielectric adhesive layer and the copper foil layer, and is a liquid crystal polymer core layer with a thickness of 12 to 100 microns.

In an embodiment, the high-frequency copper foil substrate is a single-sided copper-clad substrate structure with a thickness of 25 to 235 microns, wherein the single-sided copper-clad substrate structure includes a copper foil layer, a dielectric adhesive layer and The core layer between the copper foil layer and the dielectric adhesive layer.

In another specific embodiment, the high-frequency copper foil substrate has a double-sided copper-clad substrate structure with a first structure or a second structure.

The double-sided copper-clad substrate structure with the first structure includes a first copper foil layer, a dielectric adhesive layer, a first core layer and a second copper foil layer between the first copper foil layer and the dielectric adhesive layer And a second core layer between the second copper foil layer and the dielectric adhesive layer, wherein the thickness of the double-sided copper-clad substrate structure with the first structure is 38 to 370 microns.

The double-sided copper-clad substrate structure with the second structure includes a first copper foil layer, a dielectric adhesive layer, a first core layer and a second copper foil layer, wherein the first core layer is located on the first copper foil Between the first core layer and the second copper foil layer, and the thickness of the double-sided copper-clad substrate structure with the second structure is 26 to 270 microns .

In a specific embodiment, the core layer includes at least one of component A and component B, and the proportion of component A is 5 to 98% by weight of the total solid content of the core layer. The proportion is 2 to 90% by weight of the total solid content of the core layer. The component A is a liquid crystal polymer, and the component B is selected from the group consisting of ferroelectric ceramic powder, conductive powder, sintered silica, Teflon, a fluorine-based resin different from Teflon and flame resistant At least one of the groups of agents.

In a specific embodiment, the ferroelectric ceramic powder system is at least one selected from the group consisting of BaTiO ₃ , SrTiO ₃ , Ba(Sr)TiO ₃ , PbTiO ₃ , CaTiO ₃ and Mg ₂ TiO ₄ , and The total proportion of the ferroelectric ceramic powder is 0 to 90% by weight of the total solid content of the core layer. The conductive powder system is at least one selected from the group consisting of transition metal powder, alloy powder of transition metal, carbon black, carbon fiber, carbon nanotube, and metal oxide, and the total ratio of the conductive powder is It accounts for 0 to 45% by weight of the total solid content of the core layer.

In a specific embodiment, the ratio of the sintered carbon dioxide accounts for 0 to 45% by weight of the total solid content of the core layer, and the ratio of Teflon accounts for 0 to 45% by weight of the total solid content of the core layer. The proportion of the fluorine-based resin different from Teflon is 0 to 45% by weight of the total solid content of the core layer, and the proportion of the flame retardant is 0 to 45% by weight of the total solid content of the core layer.

In a specific embodiment, the dielectric adhesive layer includes at least one of a first component and a second component, and the sum of the ratio of the first component accounts for 5 to 98 of the total solid content of the dielectric adhesive layer The total weight ratio of the second component is 5 to 80% by weight of the total solid content of the dielectric adhesive layer. The first component is at least one selected from the group consisting of sintered silica, ferroelectric ceramic powder, conductive powder, Teflon, fluorine-based resin different from Teflon, and flame retardant, The second component is a polymer resin different from the liquid crystal polymer.

In a specific embodiment, the ferroelectric ceramic powder system is at least one selected from the group consisting of BaTiO ₃ , SrTiO ₃ , Ba(Sr)TiO ₃ , PbTiO ₃ , CaTiO ₃ and Mg ₂ TiO ₄ , and The sum of the proportions of the ferroelectric ceramic powder accounts for 0 to 90% by weight of the total solid content of the dielectric adhesive layer. The conductive powder system is at least one selected from the group consisting of transition metal powder, alloy powder of transition metal, carbon black, carbon fiber, carbon nanotube and metal oxide, and the total ratio of the conductive powder is It accounts for 0 to 45% by weight of the total solid content of the dielectric adhesive layer. The proportion of the sintered carbon dioxide is 0 to 45% by weight of the total solid content of the dielectric adhesive layer, and the proportion of the Teflon is 0 to 45% by weight of the total solid content of the dielectric adhesive layer, which is different from iron fluoride The proportion of the dragon's fluorine-based resin is 0 to 45% by weight of the total solid content of the dielectric adhesive layer, and the proportion of the flame retardant is 0 to 45% by weight of the total solid content of the dielectric adhesive layer.

The invention further provides a method for manufacturing the above-mentioned high-frequency copper foil substrate, which comprises: coating the precursor of the core layer on the copper foil layer; and drying the precursor of the dielectric layer after coating the core layer And pressing, so that the core layer is located between the copper foil layer and the dielectric adhesive layer, that is, the high-frequency copper foil substrate with the single-sided copper-clad substrate structure.

In an embodiment, the method includes pressing a release layer on the dielectric adhesive layer.

In another embodiment, the method for manufacturing a high-frequency copper foil substrate provided by the present invention includes: coating a first core layer and a second core layer on a first copper foil layer and a second copper foil layer, respectively Precursor; coating the precursor of the dielectric adhesive layer on the surface of the first core layer or the second core layer, followed by drying and pressing; and the core layer of the dielectric adhesive layer and the uncoated dielectric adhesive layer Pressing, so that the dielectric adhesive layer is located between the first core layer and the second core layer, and after pressing is cured at, for example, 180 ℃ for more than 5 hours, to obtain a double-sided copper-clad substrate structure with a first structure High frequency copper foil substrate.

In yet another embodiment, the method for manufacturing a high-frequency copper foil substrate provided by the present invention includes: a precursor of a first coating core layer on a first copper foil layer; coating on the first core layer After distributing the precursor of the dielectric adhesive layer, drying and pressing are performed so that the first core layer is located between the first copper foil layer and the dielectric adhesive layer; and the second copper is pressed on the dielectric adhesive layer A foil layer, the dielectric adhesive layer is located between the first core layer and the second copper foil layer, and after being pressed, cured at 180° C. for more than 5 hours to obtain the double-sided copper clad with the second structure High-frequency copper foil substrate with substrate structure.

The beneficial effects of the present invention are:

1. The high-frequency copper foil substrate of the present invention has high dielectric constant and low dielectric loss due to the liquid crystal polymer core layer and the dielectric adhesive layer, which makes the high-frequency copper foil substrate with excellent high speed Transmittance, low loss, high Dk and low Df performance, low roughness, low water absorption, low rebound for high-density assembly, good UV laser drilling ability and excellent mechanical properties, superior to ordinary liquid crystal Molecular film and polyimide (PI) type adhesive sheet, suitable for wearable devices such as 5G smart phones and electronic watches.

In addition, in the laser drilling process, it is suitable for the processing of laser hole diameters less than 50 microns, and it is not easy to shrink. In addition, the film thickness is uniform when pressed, and the impedance is well controlled, which is more suitable for high-frequency high-speed transmission flexibility circuit board.

On the other hand, the current coating method technology can only coat a film with a thickness of about 2 mils at most. Films with a thickness of more than 38 microns are not easy to produce. The high-frequency copper foil substrate of the present invention has a suitable thickness and can Good controllability, with thick film preparation technology, it is easier to produce substrates with a thickness of 100 microns, and at this thickness, the present invention still has the characteristics of high Dk and low Df.

In addition, it is known from the test data that the high-frequency copper foil substrate of the present invention has a water absorption rate of 0.04 to 0.06%, and has the characteristics of low water absorption rate.

In addition, as can be seen from the test data, the adhesion strength of the present invention is greater than 0.8 kilogram-force/square centimeter (kgf/cm ² ).

2. The matching structure of the high-frequency copper foil substrate of the present invention has a simple composition, which can simplify the downstream processing process.

The above description of the present invention is only an overview of the technical solutions of the present invention. In order to understand the technical means of the present invention more clearly and can be implemented in accordance with the content of the specification, the following is a detailed description of preferred embodiments of the present invention and the accompanying drawings as follows: Rear.

10, 20, 30 ‧‧‧ First copper foil layer

11, 21, 31‧‧‧ First core layer

12, 22, 32 ‧‧‧ dielectric adhesive layer

20’, 30’‧‧‧Second copper foil layer

21’‧‧‧second core layer

13‧‧‧ Release layer

Exemplary embodiments of the present invention will be described with reference to the accompanying drawings: FIG. 1 is a schematic structural view of a first embodiment of the present invention (single-sided copper-clad substrate with a release layer); FIG. 2 is a diagram of the present invention The structure diagram of the second embodiment (a double-sided copper-clad substrate with a first structure); FIG. 3 is the structure diagram of a third embodiment of the present invention (a double-sided copper-clad substrate with a second structure).

The following describes the implementation of the present invention by specific specific examples. Those skilled in the art can easily understand the advantages and effects of the present invention from the contents disclosed in this specification.

It should be noted that the structure, ratio, size, etc. shown in the drawings of this specification are only used to match the content disclosed in the specification, for those who are familiar with this skill to understand and read, not to limit the implementation of the present invention The limited conditions do not have technical significance. Any modification of structure, change of proportional relationship or adjustment of size should still fall within the scope of the invention without affecting the efficacy and the purpose of the invention. The technical content disclosed by the invention can be covered. At the same time, references such as "first", "second", "lower" and "upper" in this specification are only for the convenience of description, not to limit the scope of the invention, and the relative relationship Changes or adjustments are considered to be within the scope of the invention without substantial changes in technical content. In addition, all ranges and values herein are inclusive and combinable. Any value or point that falls within the range described herein, for example, any integer can be used as the minimum or maximum value to derive the lower range.

The single-sided copper-clad substrate structure described above includes a first copper foil layer 10 with a thickness of 1 to 35 micrometers ( μm ), a dielectric constant (Dk) value of 6 to 100 and A dielectric adhesive layer 12 having a dielectric loss factor (Df) value of 0.002 to 0.010, a first core layer 11 having a Dk value of 6 to 100 and a Df value of 0.002 to 0.010, and a separation formed on the dielectric adhesive layer 12 The mold layer 13, wherein the first core layer 11 is located between the first copper foil layer 10 and the dielectric adhesive layer 12, the dielectric adhesive layer 12 is located between the release layer 13 and the first core layer 11, The thickness of the dielectric adhesive layer is 12 to 100 microns, and the material forming the first core layer 11 includes liquid crystal polymers, and the thickness is 12 to 100 microns.

In an embodiment, the high-frequency copper foil substrate is a single-sided copper-clad substrate structure, a double-sided copper-clad substrate structure with a first structure, or a double-sided copper-clad substrate structure with a second structure.

FIG. 2 shows the above-mentioned double-sided copper-clad substrate structure with the first structure, which includes the first copper foil layer 20, the dielectric adhesive layer 22, the first copper foil layer 20 and the dielectric adhesive layer The first core layer 21 between 22, the second copper foil layer 20', and the second core layer 21' between the second copper foil layer 20' and the dielectric adhesive layer 22.

The above double-sided copper-clad substrate structure with the second structure, as shown in FIG. 3, includes a first copper foil layer 30, a dielectric adhesive layer 32, a first core layer 31, and a second copper foil layer 30' , Wherein the first core layer 31 is located between the first copper foil layer 30 and the dielectric adhesive layer 32, and the dielectric adhesive layer 32 is located between the first core layer 31 and the second copper foil layer 30' between.

The subsequent strength is greater than 0.8 kilogram-force per square centimeter (kgf/cm ² ).

In a specific embodiment, the core layer includes at least one of component A and component B, and the proportion of component A is 5 to 98% by weight of the total solid content of the core layer, such as 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 98% by weight, the component B The ratio is 2 to 90% by weight of the total solid content of the core layer, such as 2, 4, 6, 8, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90% by weight. The component A is a liquid crystal polymer, and the component B is selected from the group consisting of ferroelectric ceramic powder, conductive powder, sintered silica, Teflon, a fluorine-based resin different from Teflon and flame resistant At least one of the groups of agents.

In a specific embodiment, the ferroelectric ceramic powder system is at least one selected from the group consisting of BaTiO ₃ , SrTiO ₃ , Ba(Sr)TiO ₃ , PbTiO ₃ , CaTiO ₃ and Mg ₂ TiO ₄ , and The total proportion of the ferroelectric ceramic powder accounts for 0 to 90% by weight of the total solid content of the core layer, such as 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15 , 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90% by weight. The conductive powder system is at least one selected from the group consisting of transition metal powder, alloy powder of transition metal, carbon black, carbon fiber, carbon nanotube and metal oxide, and the total ratio of the conductive powder is 0 to 45% by weight of the total solid content of the core layer, for example 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 35, 40, 45 weight%.

In a specific embodiment, the proportion of the sintered carbon dioxide accounts for 0 to 45% by weight of the total solid content of the core layer, such as 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 , 15, 20, 25, 30, 35, 40, 45% by weight, the proportion of Teflon accounts for 0 to 45% by weight of the total solid content of the core layer, such as 0, 1, 2, 3, 4, 5 , 6, 7, 8, 9, 10, 15, 20, 25, 30, 35, 40, 45% by weight, the ratio of the fluorine-based resin different from Teflon accounts for 0 to 0 of the total solid content of the core layer 45% by weight, such as 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 35, 40, 45% by weight, and the proportion of the flame retardant is 0 to 45% by weight of the total solid content of the core layer, for example 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 35, 40, 45 weight%.

In a specific embodiment, the dielectric adhesive layer includes at least one of a first component and a second component, and the sum of the ratio of the first component accounts for 5 to 98 of the total solid content of the dielectric adhesive layer % By weight, for example 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 98% by weight, the sum of the proportions of the second component accounts for 5 to 80% by weight of the total solid content of the dielectric adhesive layer, such as 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80% by weight. The first component is at least one selected from the group consisting of sintered silica, ferroelectric ceramic powder, conductive powder, Teflon, fluorine-based resin different from Teflon, and flame retardant, The second component is a polymer resin different from the liquid crystal polymer.

In a specific embodiment, the ferroelectric ceramic powder system is at least one selected from the group consisting of BaTiO3, SrTiO3, Ba(Sr)TiO3, PbTiO3, CaTiO3, and Mg2TiO4, and the ferroelectric ceramic powder The sum of the ratios is 0 to 90% by weight of the total solid content of the dielectric adhesive layer, for example 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30 , 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90% by weight. The conductive powder system is at least one selected from the group consisting of transition metal powder, alloy powder of transition metal, carbon black, carbon fiber, carbon nanotube and metal oxide, and the total ratio of the conductive powder is 0 to 45% by weight of the total solid content of the dielectric adhesive layer, such as 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 35, 40 , 45% by weight.

In another embodiment. The ferroelectric ceramic powder in the core layer and the dielectric adhesive layer may be doped with one or more metal ions, or may not be doped.

In a specific embodiment, the proportion of the sintered carbon dioxide accounts for 0 to 45% by weight of the total solid content of the dielectric adhesive layer, for example 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 , 10, 15, 20, 25, 30, 35, 40, 45% by weight, the proportion of the Teflon is 0 to 45% by weight of the total solid content of the dielectric adhesive layer, for example 0, 1, 2, 3 , 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 35, 40, 45% by weight, the proportion of the fluorine-based resin different from Teflon accounts for the dielectric adhesive layer 0 to 45% by weight of the total solid content, for example 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 35, 40, 45% by weight, the The proportion of flame retardant is 0 to 45% by weight of the total solid content of the dielectric adhesive layer, such as 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 35, 40, 45% by weight.

In an embodiment, the polymer resin different from the liquid crystal polymer is selected from the group consisting of fluorine-based resin, epoxy resin, acrylic resin, urethane-based resin, silicone rubber-based resin, poly At least one of the group consisting of xylene resin, bismaleimide resin and polyimide resin.

In a specific embodiment, the fluorine-based resin contained in the core layer and the dielectric adhesive layer different from Teflon is selected from the group consisting of polyvinylidene fluoride, vinyl fluoride-vinyl ether copolymer, and tetrafluoroethylene- Ethylene copolymer, polychlorotrifluoroethylene-ethylene copolymer, tetrafluoroethylene, hexafluoropropylene-vinylidene fluoride copolymer, tetrafluoroethylene-perfluoroalkyl ethylene copolymer, polychlorotrifluoroethylene, polyvinyl chloride, At least one of the group consisting of tetrafluoroethylene-hexafluoropropylene copolymer, ethylene-fluoroethylene copolymer and tetrafluoroethylene-hexafluoropropylene-trifluoroethylene copolymer.

In this embodiment, both the first and second copper foil layers can be low-profile copper foil layers, and the surface roughness (Rz) value of the adhesive surface of the core layer or the dielectric adhesive layer is 0.1 to 2.0 microns ( μ m), and the surface roughness (Rz) value of the non-adhesive surface of the copper foil layer is 0.1 to 0.7 microns ( μ m).

The low-profile copper foil layer is a rolled copper foil layer (RA) or an electrolytic copper foil layer (ED).

The invention further provides a method for manufacturing the above single-sided copper-clad substrate structure, which comprises: coating the core layer precursor with N-methylpyrrolidone (NMP) as a solvent on a copper foil layer, and removing the solvent at 60 to 180°C , And tempered at 250 ℃ for 10 hours; and the precursor of the dielectric adhesive layer is coated on the core layer with methyl ethyl ketone (MEK) as a solvent, followed by drying and pressing, so that the core layer is located in the copper foil Between the layer and the dielectric adhesive layer.

In an embodiment, the method includes pressing a release layer on the dielectric adhesive layer.

The release layer is a release film, and its material is at least one selected from the group consisting of polypropylene, biaxially oriented polypropylene, and polyethylene terephthalate, and may have a double-sided release Release film or release paper with the ability to mold.

The present invention further provides a method for manufacturing the double-sided copper-clad substrate structure with the first structure described above, which comprises: coating the first core layer and the second core layer on the first copper foil layer and the second copper foil layer with NMP as a solvent For the precursor of the second core layer, remove the solvent at 60 to 180°C and temper at 250°C for 10 hours; after coating the precursor of the dielectric adhesive layer with MEK as the solvent on the first core layer or the second core layer Performing drying and pressing; and laminating the dielectric adhesive layer and the core of the uncoated dielectric adhesive layer so that the dielectric adhesive layer is located between the first core layer and the second core layer, and After pressing, it is cured at 180°C for more than 5 hours.

The present invention further provides a method for manufacturing the double-sided copper-clad substrate structure with the second structure described above, which comprises: coating the precursor of the first core layer with NMP as the solvent on the first copper foil layer at 60 to 180°C Remove the solvent and temper at 250°C for 10 hours; apply MEK as the solvent to the precursor of the dielectric adhesive layer on the first core layer, then dry and press to make the core layer be on the copper foil layer Between the dielectric adhesive layer; and pressing the second copper foil layer on the dielectric adhesive layer, so that the dielectric adhesive layer is located between the first core layer and the second copper foil layer, and after being pressed Cure at 180°C for more than 5 hours.

In an embodiment, the method includes pressing a release layer on the first or second copper foil layer.

Example 1

The precursor of the core layer was coated with NMP as a solvent on a 1 micron copper foil layer to form a core layer with a thickness of 12 micrometers. After removing the solvent at 160°C, it was tempered at 250°C for 10 hours. An electrolytic copper foil layer (Mitsui Metals, TQ-M4-VSP) with a layer surface roughness (Rz) value of 0.6 microns. Next, the precursor of the dielectric adhesive layer is coated on the core layer with MEK as a solvent to form a dielectric adhesive layer with a thickness of 12 microns, so that the core layer is located between the dielectric adhesive layer and the copper foil layer, After drying at 130°C, it is pressed together; and the release layer is pressed on the dielectric adhesive layer to obtain a high-frequency copper foil substrate with a single-sided copper-clad substrate structure. In addition, the composition ratio of the core layer of Examples 1 to 14 is shown in Table 1, and the composition ratio of the dielectric paste layer is shown in Table 2.

The stack structure of this embodiment is a copper foil layer (1 micrometer)/core layer (12 micrometers)/dielectric adhesive layer (12 micrometers).

Examples 2 to 7

The high-frequency copper foil substrate was prepared according to the method of Example 1, but the thicknesses of the copper foil layer, core layer and dielectric adhesive layer and the surface roughness (Rz) values of the copper foil layer were adjusted as shown in Table 3.

Example 8

The precursors of the first core layer and the second core layer were coated on the first copper foil layer of 12 microns and the second copper foil layer of 12 microns with NMP as the solvent to form a first core layer with a thickness of 75 microns and A second core layer with a thickness of 75 microns, after removing the solvent at 160 ℃, tempered at 250 ℃ for 10 hours, wherein the surface roughness (Rz) value of the first copper foil layer and the second copper foil layer is 1.7 Micron electrolytic copper foil layer (Nippon Mine, JXEFL-V2). Next, the precursor of the dielectric adhesive layer is coated on the surface of the first core layer or the second core layer with MEK as a solvent, dried at 130° C., and pressed; and the dielectric adhesive layer and the uncoated medium The core layer of the adhesive layer is laminated and pressed, and cured at 180°C for 5 hours, so that the dielectric adhesive layer is located between the first core layer and the second core layer, that is, the double-sided copper clad with the first structure is obtained High-frequency copper foil substrate with substrate structure.

The stacked structure of this embodiment is a first copper foil layer (12 microns)/first core layer (75 microns)/dielectric adhesive layer (50 microns)/second core layer (75 microns)/second copper foil layer ( 12 microns).

Examples 9 to 11

The high-frequency copper foil substrate was prepared according to the method of Example 8, but the thicknesses of the first copper foil layer, the second copper foil layer, the first core layer, the second core layer and the dielectric adhesive layer and the first and the first The surface roughness (Rz) values of the two copper foil layers are shown in Table 4.

Example 12

The precursor of the core layer was coated with NMP as the solvent on the first copper foil layer of 1 micrometer to form a first core layer with a thickness of 12 micrometers. After removing the solvent at 160 ℃, it was tempered at 250 ℃ for 10 hours. The first copper foil layer is an electrolytic copper foil layer (Mitsui Metals, TQ-M4-VSP) with a surface roughness (Rz) value of 0.7 microns. Next, the precursor of the dielectric adhesive layer is coated on the first core layer with MEK as a solvent to form a dielectric adhesive layer with a thickness of 12 microns, so that the first core layer is located between the dielectric adhesive layer and the first Between the copper foil layers, after drying at 130°C, they are pressed together: and a second copper foil layer of 1 micron is pressed onto the dielectric adhesive layer, wherein the second copper foil layer is the surface roughness (Rz) value It is a 0.6-micron electrolytic copper foil layer (Mitsui Metal, TQ-M4-VSP), which is cured at 180°C for 5 hours so that the dielectric adhesive layer is located between the first core layer and the second copper foil layer. The high-frequency copper foil substrate with a double-sided copper clad substrate structure with a second structure.

The stacked structure of this embodiment is a first copper foil layer (1 micrometer)/a first core layer (12 micrometers)/dielectric adhesive layer (12 micrometers)/second copper foil layer (1 micrometer).

Examples 13 to 14

The high-frequency copper foil substrate is prepared according to the method of Example 12, but the thickness of the first copper foil layer, the first core layer, the second core layer and the dielectric adhesive layer and the surface roughness of the first copper foil layer are adjusted ( Rz)值如表4.

Comparative example 1

The preparation method of the high-frequency copper foil substrate of Comparative Example 1 is the same as that of Example 1, except that the laminated structure of Comparative Example 1 does not contain a dielectric adhesive layer, and the first core layer is replaced with a liquid crystal polymer having a thickness of 38 microns ( LCP) substrate, and the first copper foil layer is an electrolytic copper foil layer with a thickness of 12 microns and a surface roughness (Rz) value of 1.7 microns (Nippon Mine, JXEFL-V2).

Comparative example 2

The preparation method of the high-frequency copper foil substrate of Comparative Example 2 is the same as that of Example 1, except that the laminated structure of Comparative Example 2 does not contain a dielectric adhesive layer, and the first core layer is replaced with polyimide with a thickness of 38 microns. (PI) substrate, and the first copper foil layer is an electrolytic copper foil layer (Fukuda, CF-T49A-DS-HD2) with a thickness of 12 microns and a surface roughness (Rz) value of 1.0 microns.

Comparative Example 3

The preparation method of the high-frequency copper foil substrate of Comparative Example 3 is the same as that of Example 12, except that the laminated structure of Comparative Example 3 does not contain a dielectric adhesive layer, and the first core layer is replaced with a liquid crystal polymer having a thickness of 38 microns ( LCP) substrate, and both the first copper foil layer and the second copper foil layer are electrolytic copper foil layers (Nippon Mine, JXEFL-V2) with a thickness of 12 microns and a surface roughness (Rz) value of 1.7 microns.

Comparative Example 4

The preparation method of the high-frequency copper foil substrate of Comparative Example 4 is the same as that of Example 12, except that the laminated structure of Comparative Example 4 does not contain a dielectric adhesive layer, and the first core layer is replaced with polyimide with a thickness of 38 microns. (PI) substrate, and both the first copper foil layer and the second copper foil layer are electrolytic copper foil layers (Fukuda, CF-T49A-DS-HD2) with a thickness of 12 microns and a surface roughness (Rz) value of 1.0 microns.

The dielectric constant (Dk), dielectric loss factor (Df), water absorption rate, and then the dielectric constant (Dk), the dielectric loss factor (Df) of the high-frequency copper foil substrates produced in the above Examples 1 to 14 and Comparative Examples 1 to 4 were tested according to the "Test Guidelines for Flexible Board Assembly Requirements" The strength, the rebound force of the copper-containing foil layer and the copper-free foil layer are described in Table 3 and Table 4 according to the structure of the single-sided copper foil substrate structure and the double-sided copper foil substrate structure, respectively.

It can be seen from Tables 3 and 4 that the high-frequency copper foil substrate of the present invention has excellent high-speed transmission, low loss, high Dk and low Df performance, low roughness, low water absorption, and good UV laser drilling ability And excellent mechanical properties, better than the general LCP film and PI-type adhesive sheet, suitable for wearable devices such as 5G smart phones and electronic watches.

The above-mentioned embodiments are only illustrative and not intended to limit the present invention. Anyone who is familiar with this skill can modify and change the above embodiments without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the rights of the present invention is defined by the scope of the patent application attached to the present invention, as long as it does not affect the effects and implementation purposes of the present invention, it should be covered in the disclosed technical content.

10‧‧‧The first copper foil layer

11‧‧‧The first core layer

12‧‧‧Dielectric adhesive layer

13‧‧‧ Release layer

Claims (13)

A high-frequency copper foil substrate comprising: a copper foil layer with a thickness of 1 to 35 micrometers (μm); a dielectric constant (Dk) value of 6 to 100, a dielectric loss factor (Df) value of 0.002 to 0.010 and A dielectric adhesive layer with a thickness of 12 to 100 microns; and a core layer with a Dk value of 6 to 100, a Df value of 0.002 to 0.010, and a thickness of 12 to 100 microns, wherein the core layer is located on the dielectric adhesive layer and Between the copper foil layers, the material forming the core layer includes liquid crystal polymer. The high-frequency copper foil substrate as described in item 1 of the patent scope, wherein the thickness of the high-frequency copper foil substrate is 25 to 235 microns. The high-frequency copper foil substrate as described in item 1 of the patent application scope includes another core layer and another copper foil layer, and the other core layer is located between the dielectric adhesive layer and another copper foil layer And the thickness of the high-frequency copper foil substrate is 38 to 370 microns. The high-frequency copper foil substrate as described in item 1 of the patent application range includes another copper foil layer, so that the dielectric adhesive layer is located between the core layer and another copper foil layer, and the high-frequency copper foil The thickness of the substrate is 26 to 270 microns. The high-frequency copper foil substrate as described in item 1 of the patent scope, wherein the core layer includes at least one of component A and component B, wherein component A is a liquid crystal polymer, and component B is selected Free ferroelectric ceramic powders, conductive powders, sintered silica, Teflon, fluorine-based resins different from Teflon and at least one of the group consisting of flame retardants, and the proportion of the component A It is 5 to 98% by weight of the total solid content of the core layer, and the proportion of the component B is 2 to 90% by weight of the total solid content of the core layer. The high-frequency copper foil substrate as described in item 5 of the patent application range, wherein the ferroelectric ceramic powder system is selected from the group consisting of BaTiO ₃ , SrTiO ₃ , Ba(Sr)TiO ₃ , PbTiO ₃ , CaTiO ₃ and Mg ₂ TiO ₄ at least one of the groups formed, and the total proportion of the ferroelectric ceramic powder accounts for 0 to 90% by weight of the total solid content of the core layer; and the conductive powder system is selected from transition metal powder, transition At least one of the group consisting of metal alloy powder, carbon black, carbon fiber, nano carbon tube and metal oxide, and the sum of the proportion of the conductive powder accounts for 0 to 45% by weight of the total solid content of the core layer . The high-frequency copper foil substrate as described in item 5 of the patent application scope, wherein the proportion of the sintered carbon dioxide accounts for 0 to 45% by weight of the total solid content of the core layer, and the proportion of the Teflon accounts for the total of the core layer 0 to 45% by weight of solid content, the ratio of the fluorine-based resin different from Teflon accounts for 0 to 45% by weight of the total solid content of the core layer, and the proportion of the flame retardant accounts for the total solid content of the core layer 0 to 45% by weight. The high-frequency copper foil substrate as described in item 1 of the patent application range, wherein the dielectric adhesive layer includes at least one of a first component and a second component, wherein the first component is selected from the group consisting of sintered dioxide At least one of the group consisting of silicon, ferroelectric ceramic powder, conductive powder, Teflon, fluorine-based resin and flame retardant different from Teflon, and the second component is different from the liquid crystal high Molecular polymer resin, and the sum of the proportion of the first component accounts for 5 to 98% by weight of the total solid content of the dielectric layer, the sum of the proportion of the second component accounts for the total of the dielectric layer 5 to 80% by weight of solid content. The high-frequency copper foil substrate as described in Item 8 of the patent application range, wherein the ferroelectric ceramic powder system is selected from the group consisting of BaTiO ₃ , SrTiO ₃ , Ba(Sr)TiO ₃ , PbTiO ₃ , CaTiO ₃ and Mg ₂ TiO ₄ at least one of the groups formed, and the sum of the proportion of the ferroelectric ceramic powder accounts for 0 to 90% by weight of the total solid content of the dielectric adhesive layer; the conductive powder system is selected from the group consisting of transition metal powder, Transition metal alloy powder, carbon black, carbon fiber, carbon nanotubes, and metal oxides are at least one group, and the sum of the proportion of the conductive powder is 0 to 0 of the total solid content of the dielectric adhesive layer 45% by weight; and the proportion of the sintered carbon dioxide accounts for 0 to 45% by weight of the total solid content of the dielectric adhesive layer, the proportion of Teflon accounts for 0 to 45% by weight of the total solid content of the dielectric adhesive layer, The ratio of the fluorine-based resin different from Teflon accounts for 0 to 45% by weight of the total solid content of the dielectric adhesive layer, and the ratio of the flame retardant accounts for 0 to 45 weight of the total solid content of the dielectric adhesive layer %. A method for preparing a high-frequency copper foil substrate includes: coating a precursor of a core layer on a copper foil layer; and drying and pressing together after coating a precursor of a dielectric adhesive layer on the core layer The core layer is located between the copper foil layer and the dielectric adhesive layer. The method for manufacturing a high-frequency copper foil substrate as described in item 10 of the patent application range includes pressing a release layer on the dielectric adhesive layer. A method for preparing a high-frequency copper foil substrate includes: coating precursors of a first core layer and a second core layer on a first copper foil layer and a second copper foil layer, respectively; on the first core layer or the second The surface of the core layer is coated with the precursor of the dielectric adhesive layer, followed by drying and pressing; and laminating the dielectric adhesive layer with the core of the uncoated dielectric adhesive layer so that the dielectric adhesive layer is located at the Between the first core layer and the second core layer. A method for preparing a high-frequency copper foil substrate includes: coating a precursor of a first core layer on a first copper foil layer; drying the precursor of a dielectric adhesive layer on the first core layer and then drying And pressing, so that the first core layer is located between the first copper foil layer and the dielectric adhesive layer; and pressing the second copper foil layer on the dielectric adhesive layer, so that the dielectric adhesive layer is located in the first Between a core layer and the second copper foil layer.

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