TWI785011B - Static bendable copper clad laminate, manufacturing method and bending forming method thereof - Google Patents

Abstract

The invention provides a statically bendable copper clad laminate, a manufacturing method and a bending forming method thereof. The copper clad laminate of the present invention comprises copper foil and a base cloth impregnated with a thermosetting resin composition adhered to the copper foil, the flexural modulus of elasticity of the copper clad laminate is >10GPa, and the peel strength between 60°C and 200°C is greater than 1.0 N/mm, and after removing the copper foil, it has a maximum stress value greater than 400MPa and a fracture strain value greater than 4%. The copper clad laminate can be formed into a copper clad laminate with a curved structure by one or several times of stamping.

Description

Static bendable copper clad laminate, manufacturing method and bending forming method thereof

The invention relates to the technical field of copper clad laminates, in particular to a statically bendable copper clad laminate, a manufacturing method thereof, and a bending forming method.

Copper-clad laminates mainly play the role of mechanical support and electrical connection in the application of the electronics industry. However, in the requirements of three-dimensional installation and partial three-dimensional support, traditional rigid copper-clad laminates are easy to break during bending due to their relatively high brittleness; traditional Flexible Copper Clad Laminates (FCCL), while good at bending, do not have enough support to be used alone for support. In addition, when rigid copper-clad laminates and flexible copper-clad laminates are used as rigid-flex boards, the processing procedures are complicated, the processing is difficult, and the cost is high.

Many electronic products and electromechanical industries have requirements for static bending applications of materials. The so-called static bending means that it only needs to be bent once during installation, or after one bending is formed, the bending area does not need to swing, that is, during work. It is static, unlike the laser head of a printer that swings back and forth; however, even in these static bending fields, in many cases, ordinary rigid copper clad laminates cannot meet the requirements of bending and forming.

Therefore, in many static bending application fields, the copper clad laminate material is required to have the processing ability of one or several times of bending and forming. The curved or concave-convex shape is fixed, which is convenient for subsequent static bending installation.

The present invention aims to provide a new type of rigid and tough copper clad laminate and its bending forming method without using flexible cladding (FCCL). The copper clad laminate can be plastically deformed within a certain temperature range and under the action of mechanical force. When the mechanical force is released and returned to normal temperature, the shape produced by the original deformation will not change, and the shape can be fixed.

The purpose of the present invention can be achieved through the following technical solutions.

One aspect of the present invention provides a statically bendable copper-clad laminate, the copper-clad laminate comprises copper foil and a base cloth impregnated with a thermosetting resin composition adhered to the copper foil, and the elastic flexural modulus of the copper-clad laminate is > 10GPa (Preferably >12GPa), the peel strength between 60°C and 200°C is greater than 1.0N/mm, and after removing the copper foil, it has a maximum stress value greater than 400MPa and a fracture strain value greater than 4%.

In some embodiments, the thermosetting resin composition comprises: a thermosetting resin; a curing agent; a toughening material; and a solvent, wherein based on 100 parts by weight of the thermosetting resin, the curing agent is 1 to 50 parts by weight, and the toughening material 20 to 60 parts by weight, and 5 to 50 parts by weight of the solvent.

In some embodiments, the thermosetting resin includes an epoxy resin, preferably a multifunctional epoxy resin; and/or, the curing agent includes a phenolic resin, an amine compound, an acid anhydride, an imidazole compound, a columium salt, a dicyandiamide At least one of amines and active esters; and/or, the toughening material includes rubber (preferably core-shell rubber), phenolic resin, polyvinyl butyral (PVB), nylon, nanoparticles (preferably SiO ₂ , TiO ₂ , or CaCO ₃ nanoparticles), olefinic block copolymers (preferably polymethacrylic acid, butadiene, and styrene block copolymers); and/or, the solvent Including at least one of dimethylformamide (DMF), ethylene glycol monomethyl ether (MC), propylene glycol methyl ether (PM), methyl ethyl ketone (MEK), toluene, and xylene.

In some embodiments, the base fabric includes glass fiber cloth or non-woven fabric.

Another aspect of the present invention provides a method for manufacturing the above-mentioned copper clad laminate, the method comprising: impregnating or coating the base cloth with a thermosetting resin composition, and heating at 100°C to 200°C for 1 minute to 10 minutes to form a prepreg; Lay it on the copper foil, and carry out thermocompression curing at a temperature not exceeding 180°C to 200°C for 40 minutes to 120 minutes to form a copper clad laminate.

Another aspect of the present invention provides a copper clad laminate bending forming method, the method comprising: putting the copper clad laminate described in any one of claims 1 to 4 into a mold for stamping and forming, and the mold is designed to form A curved structure with a bending angle of 10° to 90° and a bending radius of 1 mm to 25 mm.

In some embodiments, the copper clad laminate is heated to a temperature of 60° C. to 200° C. before being put into a mold.

In some embodiments, the stamping conditions include: 1) Stamping pressure: 100N-20000N; 2) Press-forming maintenance time: ≥2 sec; 3) Mold temperature: room temperature (20°C-35°C), Or heated to below 100°C.

In some embodiments, the forming temperature of the stamping forming is ±50° C. from the glass transition temperature of the thermosetting resin composition in the copper clad laminate, and the setting time is ≥2 sec.

Another aspect of the present invention also provides a copper-clad laminate with a curved structure, which is manufactured by one or several times of forming using the above-mentioned bending forming method, and has a bending angle of 10°-90° and a bending angle of 1 mm-25 mm. bend radius.

The present invention can have at least one of the following advantages: 1. The copper-clad laminate of the present invention can be plastically deformed within a certain temperature range and under the action of mechanical force. When the mechanical force is released and returned to normal temperature, the shape produced by the original deformation will not change It can be fixed and shaped, that is, it has a certain rigidity to withstand stress and produce deformation without breaking, and has a deformation strain number. 2. The production process of copper clad laminates is simple, without the use of flexible boards (FCCL), which improves efficiency and saves costs. 3. The copper clad laminate has the processing ability of one or several times of bending and forming. During the bending and forming process, it can better withstand the impact stress, without cracking or delamination, and it can be punched out of various three-dimensional bending or concave-convex shapes, which is convenient for subsequent static bending. Install and use.

The present invention unexpectedly finds that: use a thermosetting resin composition containing a toughening material to impregnate a base cloth such as glass fiber cloth to make a prepreg, laminate the prepreg with copper foil, and obtain a rigid and tough (or hard) prepreg after complete curing. And tough) characteristics of the copper clad laminate.

The stress-strain curve of a material with hard and ductile properties is shown in curve 2 in Figure 1. In Figure 1, the material properties represented by each curve are as follows: 1. Hard and brittle; 2. Hard and tough; 3. Hard and strong; 4. Soft and tough; 5. Soft and weak.

Based on the above findings, the present invention provides a statically bendable copper clad laminate, a manufacturing method thereof, and a bending forming method thereof. Various aspects of the invention are described in detail below.

cover copper plate

One aspect of the present invention provides a statically bendable copper-clad laminate, the copper-clad laminate comprising a copper foil and a base cloth adhered to the copper foil and impregnated with the above-mentioned thermosetting resin composition.

thermosetting resin composition

In the present invention, the thermosetting resin composition used for impregnating the base cloth may include: a thermosetting resin; a curing agent; a toughening material; and a solvent.

In certain embodiments, the thermosetting resin may include epoxy resin, phenolic resin, polyimide resin, urea-formaldehyde resin, melamine resin, unsaturated polyester, polyurethane resin, etc., among which epoxy resin is preferred.

Specific examples of epoxy resins may include bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, aralkyl epoxy resins, phenol novolac type epoxy resins type epoxy resin), alkylphenol novolac type epoxy resin (alkylphenol novolac type epoxy resin), bisphenol type epoxy resin, naphthalene type epoxy resin, dicyclopentadiene type epoxy resin, phenolic compound and phenolic hydroxyl Epoxides condensed from aromatic aldehydes, triglycidyl isocyanurate, alicyclic epoxy resins, etc. Depending on circumstances, these epoxy resins can be used alone or in combination of two or more.

Preferably, the epoxy resin is a polyfunctional epoxy resin containing two or more epoxy groups (preferably three or more epoxy groups) in one molecule. Commercially available epoxy resins can be used for this epoxy resin, for example, JER1003 (manufactured by Mitsubishi Chemical Corporation, with 7 to 8 methyl groups, difunctional, molecular weight of 1300), EXA-4816 (manufactured by Dickson, molecular weight of 824, majority methyl, difunctional), YP50 (manufactured by Nippon Steel Sumitomo Metal Chemical Co., Ltd., molecular weight 60,000 to 80,000, majority methyl, difunctional), DER593 (manufactured by Dow Chemical, multifunctional epoxy resin), EPIKOTE 157 (manufactured by Resolution, multifunctional epoxy resin) and the like.

In some embodiments, the curing agent in the thermosetting resin composition may be determined according to the type of the thermosetting resin. For epoxy resins, the curing agent may include at least one of phenolic resins, amine compounds, acid anhydrides, imidazole compounds, cobalt salts, dicyandiamide, and active esters.

其中式中X為苯環或萘環，j為0或1，k為0或1，n表示平均重複單元為0.25～1.25。The active ester curing agent is obtained by reacting a phenolic compound connected through an alicyclic hydrocarbon structure, a difunctional carboxylic acid aromatic compound or an acid halide and a monohydroxyl compound. The amount of difunctional carboxylic acid aromatic compound or acid halide is 1 mol, the amount of phenolic compound linked by alicyclic hydrocarbon structure is 0.05-0.75 mol, and the amount of monohydroxy compound is 0.25-0.95 mol. Active ester solidifying agent can comprise the active ester of following structural formula:

In the formula, X is a benzene ring or a naphthalene ring, j is 0 or 1, k is 0 or 1, and n represents an average repeating unit of 0.25 to 1.25.

In some embodiments, the curing agent is preferably phenolic resin, amine compound, imidazole compound and dicyandiamide. These curing agents can be used alone or in combination of two or more. Specific curing agents may include: phenolic resins (such as phenol novolak resin, cresol novolak resin, etc.); diaminodiphenylsulfone (DDS); dicyandiamide (DICY); dimethylimidazole (2-MI) Wait.

With respect to 100 parts by weight of the thermosetting resin, the amount of the curing agent is usually 1-50 parts by weight, for example, 1-40 parts by weight, or 1-30 parts by weight. For epoxy resin, the amount of curing agent can be controlled so that the epoxy equivalent of epoxy resin and the hydroxyl equivalent ratio of phenolic resin are 1:1~0.95; or the equivalent ratio of epoxy resin to amine group is 1:0.6~ 0.4.

In certain embodiments, the toughening material includes at least one of rubber, phenolic resin, polyvinyl butyral (PVB), nylon, nanoparticles, olefinic block copolymers. These toughening materials are selected based on their compatibility with thermosetting resins such as epoxy resins, their toughening effects (to achieve the corresponding stress and strain requirements (see subsequent descriptions)), etc. Among them, the rubber is preferably rubber with a core-shell structure, such as methyl methacrylate-butadiene-styrene (MBS) core-shell copolymer resin, rubber-epoxy core-shell resin, etc., and its representative commercially available Including M-521 and MX-395 of Japan Zhongyuan Company. Nanoparticles include SiO ₂ , TiO ₂ , or CaCO ₃ nanoparticles, etc., and the particle size is generally 10 nm to 500 nm. Olefinic block copolymers are block copolymers formed by the copolymerization of different types of olefins, such as polymethacrylic acid, butadiene and styrene block copolymers.

Toughening materials can be used alone or in combination of two or more. For example, nanoparticles can be mixed with another toughening material (such as core-shell rubber, phenolic resin, PVB, nylon, olefinic block copolymer, or mixtures thereof) in a weight ratio of 1:10 to 2:1 Use in combination.

In order to achieve a good toughening effect, the total amount of toughening material is generally 20-60 parts by weight relative to 100 parts by weight of thermosetting resin, for example, it can be 20-50 parts by weight, or 30-60 parts by weight.

In certain embodiments, solvents may include dimethylformamide (DMF), ethylene glycol methyl ether (MC), propylene glycol methyl ether (PM), propylene glycol methyl ether acetate (PMA), cyclohexanone, methyl ethyl ketone (MEK), toluene, xylene at least one. Relative to 100 parts by weight of thermosetting resin, the amount of solvent used is generally 5 to 50 parts by weight, such as 10 to 50 parts by weight, 20 to 50 parts by weight, etc., to form a glue with a viscosity of 300 cPa s to 600 cPa s .

In some embodiments, within the scope of not losing the effect of the present invention, the thermosetting resin composition may also contain fillers or auxiliary agents, such as flame retardants, leveling agents, colorants, dispersants, coupling agents, Foaming agent, etc. Wherein the flame retardant may be an organic flame retardant, such as one or more of tetrabromobisphenol A, DOPO, and phosphoric acid ester.

Base Fabric In certain embodiments, the base fabric comprises fiberglass cloth or nonwoven fabric. Glass fiber cloth can be used in various specifications such as 7628, 2116, 1080, 106, 1037, 1027, 1017 and so on.

Copper foil In some embodiments, the copper foil can be selected in different specifications such as 1OZ, 1/2OZ, 1/3OZ, etc.

Statically bendable copper clad laminate The statically bendable copper clad laminate of the present invention can be plastically deformed within a certain temperature range and under the action of mechanical force. When the mechanical force is released and returned to normal temperature, the shape produced by the original deformation will not change , can be fixed and formed.

In some embodiments, the elastic flexural modulus of the copper clad laminate is > 10GPa, the peel strength between 60°C and 200°C is greater than 1.0N/mm, and after removing the copper foil, it has a maximum stress value greater than 400MPa and greater than 4% strain at break.

The above stress and strain values are determined by the following tensile strength and tensile modulus test methods.

Material tensile strength and tensile modulus test method:

A. Test device/or material

Material testing machine An ISO3384 standard tensile and compression testing machine, the tensile fixture of the device can run at a stable rate. The error of the load measurement system does not exceed ±1%.

Etching system capable of complete removal of clad metal foil.

Vernier caliper (accurate to 0.02 mm) or micrometer (accurate to 0.002 mm)

(1) Size and shape of the sample The size of the sample is 250mm×25mm, and the thickness of the sample is recommended to be 0.4mm. rounded corners). (2) Quantity and sampling When the dispersion coefficient is less than 5%, use ten samples for each batch, five vertically and five horizontally (cut from the whole sample plate or small plate). When the dispersion coefficient is greater than 5%, the number of samples in each direction shall not be less than 10, and 10 effective samples shall be guaranteed. (3) Etch to remove all metal covering layers by etching.

B. Tensile test program

Measure the size of the sample Measure and record the width and thickness of the sample, the width is accurate to 0.02 mm, and the thickness is accurate to 0.002 mm.

Measurement (1) Clamp the sample so that the center line of the sample is consistent with the alignment center line of the upper and lower clamps. (2) Adjust the distance between the upper and lower clamps to make it 125 mm ± 0.5 mm. (3) The loading speed is 12.5 mm/min. (4) When setting the calculation of the tensile modulus of elasticity, take the part between 0.05% and 0.25% of the strain. (5) Carry out the test and draw the stress-strain curve. (6) Samples with obvious internal defects shall be discarded. (7) If the sample is damaged in the fixture or the distance between the fractured part of the sample and the clamping part is less than 10 mm, it shall be discarded.

C. Calculate

式中：

：拉伸強度，MPa F：破壞載荷或最大載荷，N b：試樣寬度，mm d：試樣厚度，mmCalculate the tensile strength of each sample according to the formula

In the formula:

: Tensile strength, MPa F: Failure load or maximum load, N b: Specimen width, mm d: Specimen thickness, mm

式中：

：拉伸彈性模量，MPa

：應變

時測得的拉伸應力值，MPa

：應變

時測得的拉伸應力值，MPaCalculate the tensile modulus of elasticity of each sample according to the following formula

In the formula:

: Tensile modulus of elasticity, MPa

:strain

Tensile stress value measured at , MPa

:strain

Tensile stress value measured at , MPa

Calculate the average tensile strength and tensile elastic modulus in MPa.

Figure 2 shows a typical stress-strain curve of the copper clad laminate obtained according to the above tensile strength and tensile modulus test methods. As shown in FIG. 2 , the copper clad laminate of the present invention (after etching to remove the metal covering layer) has a maximum stress value greater than 400 MPa and a fracture strain value greater than 4%.

The method of making copper clad laminate

Copper clad laminate of the present invention can be made according to the following method:

Making Prepregs

The base cloth is impregnated or coated with the thermosetting resin composition in the form of glue of the present invention, and then heated at 100°C to 200°C for 1 minute to 10 minutes (for example, 3 minutes to 10 minutes) to obtain a prepreg (semi-cured B-stage state). The resin content of the prepreg can be controlled between 40% and 70% by weight, and the resin fluidity of the prepreg can be controlled between 10% and 30%.

Making CCL

Laminate the cut prepreg on the copper foil, hot press at a heating rate of 1-3°C/min, the maximum pressure is 300PSI-500PSI, and the maximum temperature is 180°C-200°C for 30 minutes to 120 minutes (for example 60 minutes to 120 minutes), to obtain a copper clad laminate.

cover Bending method of copper plate

Another aspect of the present invention provides a method for bending and forming a copper clad laminate, the method comprising: putting the aforementioned copper clad laminate into a mold for stamping and forming.

In some embodiments, the mold is pre-designed according to different bending radii (2 mm-50 mm) and bending angles (10°-90°).

In certain embodiments, the copper clad laminate is heated to a temperature of 60°C to 200°C before being placed into a mold.

In some embodiments, the forming temperature of the stamping forming is ±50°C (preferably ±30°C) of the glass transition temperature of the thermosetting resin composition in the copper clad laminate, and the setting time is ≥2 sec.

In some embodiments, the conditions for stamping include: 1) Stamping pressure: 100N-20000N; 2) Press-forming maintenance time: ≥2 sec; 3) Mold temperature: room temperature (20°C-35°C), or heating to below 100°C.

In some embodiments, other mold clamping parameters may include: the mold clamping speed is 0-2000 mm/min, and the upper limit of the mold clamping pressure is 100N-20000N.

In some embodiments, the number of layers of the stamped copper clad laminate may be 4-14 layers, and the thickness may be 0.2 mm-1 mm.

In certain embodiments, one or several times of stamping may be performed to achieve various bending shapes.

Copper clad laminate with curved structure

Another aspect of the present invention provides a copper clad laminate with a curved structure, which can be manufactured by the above bending forming method.

In some embodiments, the copper clad laminate has a bending angle of 10°-90° and a bending radius of 1 mm-25 mm.

In some embodiments, the copper clad laminate can be manufactured by one or several moldings.

The technical solution of the present invention will be further described below in conjunction with specific embodiments. These examples are illustrative only and are not intended to limit the scope of the present invention.

Example 1:

1. Glue preparation: use 5 parts by weight of rubber (Japan Zhongyuan M-521), 10 parts by weight of core-shell rubber (Japan Zhongyuan MX-395) and 20 parts by weight of nano-SiO ₂ (Evonik Nanopol A 710) as a toughening material, mixed with 100 parts by weight of multifunctional epoxy resin (Dow Chemical DER593 resin), and added phenolic resin (Dow Chemical XZ92741 resin), so that the ratio of epoxy equivalent to hydroxyl equivalent is 1:1 , and an appropriate amount of MEK organic solvent to prepare a glue solution, and control the viscosity of the glue between 300 cPa·s and 600 cPa·s.

2. Production of prepregs: First, glue the glass fiber cloth (2116 glass fiber cloth) impregnated with the above glue, and then put it into an oven and bake it at 100°C to 200°C for 3 minutes to 10 minutes, so that the above resin composition can reach semi-cured B. step status.

3. Copper-clad laminate production: select 1OZ copper foil, combine it with the above prepreg, put it into the laminator, the heating rate is 1-3°C/min, the maximum pressure of the pressing plate is 300PSI-500PSI, and the maximum temperature of the material is 180°C-200°C for 60 minutes ~120 minutes.

4. Bending forming: (1) First heat the above copper clad laminate to 60°C; (2) After heating the copper clad laminate to a stable temperature, put it into the punching machine, press it with a pressure of 10000N for 5 seconds, then open the mold, and take out the copper clad laminate . The bending radius and bending angle of the obtained copper clad laminate are shown in Fig. 3 and Fig. 4 .

5. Test the appearance, elastic modulus, thermal shock (288°C/10S), reflow soldering (maximum stability 280°C) and other related characteristics of the above copper clad laminate, and test the tensile strength and tensile modulus according to the description in the manual method to determine the stress-strain value.

Example 2:

A copper clad laminate was fabricated in the same manner as in Example 1 except for the following glue preparation.

Glue preparation: 20 parts by weight of phenolic resin (HEXION 53BH35) and 10 parts by weight of core-shell rubber CSR (Japan Zhongyuan MX-395) are used as toughening materials, and 100 parts by weight of multifunctional epoxy resin ( Resolution company's EPIKOTE 157 resin), and add 2.5 parts by weight of dicyandiamide, and an appropriate amount of DMF organic solvent to prepare a glue solution. Control the viscosity of the glue and apply it to glass fiber dipping and gluing.

Bending forming: (1) First heat the above copper clad laminate to 120°C; (2) After heating the copper clad laminate to a stable temperature, put it into the punching machine, press it with 100N pressure for 100 seconds, then open the mold, and take out the copper clad laminate. The bending radius and bending angle of the copper clad laminate are the same as those in Embodiment 1.

According to the method described in Example 1, relevant properties such as appearance, elastic modulus, stress-strain value, thermal shock, and reflow soldering were tested.

Example 3:

A copper clad laminate was fabricated in the same manner as in Example 1 except for the following glue preparation.

Glue preparation: 20 parts by weight of PVB (Solutia B90), 8 parts by weight of nano-SiO ₂ (Evonik Nanopolo A 710) and 5 parts by weight of block copolymer (Arkoma Nanostrength ® M52N) were used as Toughening material, mixed with 100 parts by weight of multifunctional epoxy resin (DER593 resin of DOW Chemical Company), and added 3 parts by weight of dicyandiamide, and an appropriate amount of DMF or PM organic solvent, to prepare a glue solution to control the glue The viscosity is between 300 cPa·s and 600 cPa·s.

Bending forming: (1) First heat the above copper clad laminate to 200°C; (2) After heating the copper clad laminate to a stable temperature, put it into the punching machine, press it with a pressure of 20000N for 2 seconds, then open the mold, and take out the copper clad laminate. The bending radius and bending angle of the copper clad laminate are the same as those in Embodiment 1.

According to the method described in Example 1, relevant properties such as appearance, elastic modulus, stress-strain value, thermal shock, and reflow soldering were tested.

Example 4:

A copper clad laminate was fabricated in the same manner as in Example 1 except for the following glue preparation.

Glue preparation: choose 20 parts by weight of nylon (such as: DuPont ST801A in the United States), 8 parts by weight of nano-SiO ₂ (Evonik Nanopol A 710), and 100 parts by weight of multifunctional epoxy resin (DOW chemical DER593 resin) Mix, and add phenolic resin (EPIKURE YLH129B65 from Resolution Company) and an appropriate amount of MEK organic solvent according to the epoxy equivalent and hydroxyl equivalent 1:1 to prepare a glue solution, and control the glue viscosity between 300 cPa s ~ 600 cPa s between.

Bending forming: (1) First heat the above copper clad laminate to 100°C; (2) After heating the copper clad laminate to a stable temperature, put it into the punching machine and press it with a pressure of 10000N for 10 seconds, then open the mold and take out the copper clad laminate. The bending radius and bending angle of the copper clad laminate are the same as those in Embodiment 1.

According to the method described in Example 1, relevant properties such as appearance, elastic modulus, stress-strain value, thermal shock, and reflow soldering were tested.

Example 5:

A copper clad laminate was fabricated in the same manner as in Example 1 except for the following glue preparation.

Glue preparation: 25 parts by weight of block copolymer (Arkema Nanostrength ® M52N) and 8 parts by weight of nano-SiO ₂ (Evonik Nanopol A 710) were selected as toughening materials, and 100 parts by weight of cyanate Resin (HF-10 from Huifeng Company) was mixed, and 20 parts by weight of phenolic resin (EPIKURE YLH129B65 from RESOLUTION Company) and an appropriate amount of MEK organic solvent were added to prepare a glue solution, and the viscosity of the glue was controlled at 300 cPa·s～600 cPa Between s.

Bending forming: (1) First heat the above copper clad laminate to 200°C; (2) After heating the copper clad laminate to a stable temperature, put it into the punching machine, press it with a pressure of 10000N for 20 seconds, then open the mold, and take out the copper clad laminate. The bending radius and bending angle of the copper clad laminate are the same as those in Embodiment 1.

According to the method described in Example 1, relevant properties such as appearance, elastic modulus, stress-strain value, thermal shock, and reflow soldering were tested.

Embodiment 6:

A copper clad laminate was fabricated in the same manner as in Example 1 except for the following glue preparation.

Glue preparation: 20 parts by weight of phenolic resin (Nippon Steel Chemical ERF-001), 10 parts by weight of PVB (US Solutia B90) and 5 parts by weight of nano-SiO ₂ (Evonik Nanopolo A 710) were used as Toughened material, mixed with 50 parts by weight of PPO resin (MX90 from SABIC) and 100 parts by weight of epoxy resin (DOW Chemical DER593 resin), and added 20 parts by weight of phenolic resin (EPIKURE YLH129B65 from RESOLUTION Company), And an appropriate amount of MEK organic solvent to prepare a glue solution, and control the viscosity of the glue between 300 cPa·s and 600 cPa·s.

Bending and forming: (1) First heat the above copper clad laminate to 100°C; (2) After heating the copper clad laminate to a stable temperature, put it into the punching machine and press it with a pressure of 10000N for 50 seconds, then open the mold and take out the copper clad laminate. The bending radius and bending angle of the copper clad laminate are the same as those in Embodiment 1.

According to the method described in Example 1, relevant properties such as appearance, elastic modulus, stress-strain value, thermal shock, and reflow soldering were tested.

Comparative example 1:

Except for the following glue preparation, the copper-clad laminate was manufactured and bent in the same manner as in Example 1, and the corresponding performance was tested.

Glue preparation: Select 100 parts by weight of multifunctional epoxy resin (DOW chemical DER593 resin), add 2 to 3 parts by weight of dicyandiamide, and an appropriate amount of DMF organic solvent to prepare a glue solution, and control the viscosity of the glue at 300 cPa Between s～600 cPa s.

Comparative example 2:

Except for the following glue preparation, the copper-clad laminate was manufactured and bent in the same manner as in Example 1, and the corresponding performance was tested.

Glue preparation: select 10 parts by weight of NBR (Nippon Zhongyuan M-521) and 100 parts by weight of multifunctional epoxy resin (DOW chemical DER593 resin), add 2 to 3 parts by weight of dicyandiamide, and An appropriate amount of DMF organic solvent was prepared into a glue solution, and the viscosity of the glue was controlled between 300 cPa·s and 600 cPa·s.

The test results are compared in the following table:

The above are only part of the embodiments of the present invention. For those skilled in the art, various other corresponding changes and changes can be made according to the technical solutions and technical concepts of the present invention, and all these changes and changes should belong to the present invention. The scope of the scope of the patent application for the invention.

The present invention illustrates the detailed methods of the present invention through the above examples, but the present invention is not limited to the above detailed methods, that is, it does not mean that the present invention must rely on the above detailed methods to be implemented. Those skilled in the art should understand that any improvement of the present invention, the equivalent replacement of each raw material of the product of the present invention, the addition of auxiliary components, the selection of specific methods, etc., all fall within the scope of protection and disclosure of the present invention.

none

Figure 1 shows five types of stress-strain curves. Fig. 2 shows a typical stress (F)-strain (L) curve of the copper clad laminate of the present invention obtained according to the test method of tensile strength and tensile modulus. FIG. 3 shows the bending radius of the bent and formed copper clad laminate in Example 1 of the present application. FIG. 4 shows the bending angle of the bent and formed copper clad laminate in Example 1 of the present application.

Claims (9)

A statically bendable copper-clad laminate, characterized in that the copper-clad laminate comprises copper foil and a base cloth impregnated with a thermosetting resin composition adhering to the copper foil, and the copper-clad laminate has a pressure greater than 400Mpa after the copper foil is removed. The maximum stress value and the fracture strain value greater than 4%; the thermosetting resin composition comprises: a thermosetting resin; a curing agent; a toughening material; and a solvent; based on 100 parts by weight of the thermosetting resin, the curing agent is 1 to 50 parts by weight, the toughened material is 20 to 60 parts by weight, and the solvent is 5 to 50 parts by weight; and the toughened material includes rubber, phenolic resin, polyvinyl butyral, nylon, At least two of nanoparticles and olefinic block copolymers. According to the copper clad laminate according to claim 1, wherein the thermosetting resin includes epoxy resin; and/or, the curing agent includes at least one of phenolic resin, amine compound, acid anhydride, imidazole compound, perzium salt, active ester One; and/or, the solvent includes at least one of dimethylformamide, ethylene glycol methyl ether, propylene glycol methyl ether, propylene glycol methyl ether acetate, cyclohexanone, methyl ethyl ketone, toluene, and xylene. According to the copper clad laminate according to claim 1, wherein the rubber includes rubber with a core-shell structure; the nanoparticles include SiO ₂ , TiO ₂ , or CaCO ₃ nanoparticles; the olefinic block copolymer includes poly Block copolymer of methacrylic acid, butadiene and styrene. The copper clad laminate according to claim 1, wherein the base fabric comprises glass fiber cloth or non-woven fabric. A copper clad laminate bending forming method, characterized in that the method comprises: putting the copper clad laminate described in any one of claims 1 to 4 into a mold for stamping and forming, and the mold is designed to form a bending angle of 10°~90°, and the bending structure with a bending radius of 1mm~25mm. The method according to claim 5, wherein the copper clad laminate is heated to a temperature of 60° C. to 200° C. before being put into a mold. According to the method described in claim item 6, wherein the stamping forming conditions include: 1) stamping pressure: 100N~20000N; 2) press forming maintenance time:

2sec; and 3) Mold temperature: 20°C~35°C, or heated to below 100°C. The method according to claim 5, wherein the molding temperature of the stamping molding is the glass transition temperature of the thermosetting resin composition in the copper clad laminate ± 50°C, and the setting time is

2sec. A copper-clad laminate with a curved structure, characterized in that the copper-clad laminate with a curved structure is manufactured by one or several times of molding using the method described in any one of claim items 6 to 8, and its bending angle is 10°~90°, and the bending radius is 1mm~25mm.

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