CN109749360B

CN109749360B - Thermosetting resin composition, copper-clad plate capable of being bent statically and printed circuit board prepared from thermosetting resin composition

Info

Publication number: CN109749360B
Application number: CN201711092331.2A
Authority: CN
Inventors: 刘东亮; 杨中强; 吕吉; 叶锦荣; 陈文欣; 许永静; 陈飞
Original assignee: Shengyi Technology Co Ltd
Current assignee: Shengyi Technology Co Ltd
Priority date: 2017-11-08
Filing date: 2017-11-08
Publication date: 2021-11-30
Anticipated expiration: 2037-11-08
Also published as: WO2019090917A1; TW201922895A; CN109749360A; TWI772369B

Abstract

The invention provides a thermosetting resin composition, and a copper-clad plate and a printed circuit board which are prepared from the thermosetting resin composition and can be bent statically. The thermosetting resin composition of the present invention comprises: a thermosetting resin; a curing agent; and the toughening material comprises at least one of rubber, phenoxy resin, polyvinyl butyral (PVB), nylon, nano particles and an olefinic block copolymer, wherein the curing agent accounts for 1-50 parts by weight and the toughening material accounts for 20-60 parts by weight based on 100 parts by weight of the thermosetting resin. The copper-clad plate made of the thermosetting resin composition has the elastic bending modulus of more than 10GPa, the peel strength between 60 and 200 ℃ of more than 1.0N/mm, and after the copper foil is removed, the copper-clad plate has the maximum stress value of more than 400Mpa and the fracture strain value of more than 4 percent.

Description

Thermosetting resin composition, copper-clad plate capable of being bent statically and printed circuit board prepared from thermosetting resin composition

Technical Field

The invention relates to the technical field of electronic products, in particular to a thermosetting resin composition and a copper-clad plate and a Printed Circuit Board (PCB) which are prepared by using the thermosetting resin composition and can be bent statically.

Background

Thermosetting resins are used in a wide range of fields such as electronic materials and optical materials because of their excellent heat resistance, chemical resistance, moldability, insulation reliability and the like. In particular, epoxy resins are thermosetting resins, which are generally used for various purposes. Although epoxy resins have advantages in the above properties, they are known to be generally brittle and lack flexibility. As a result, the epoxy resin is deformed or damaged when external stress or thermal stress is applied thereto, and thus the use thereof in electronic products is greatly restricted.

Materials exhibiting excellent flexibility include thermoplastic resins such as silicone resin, polyurethane resin, and polyethylene, and various materials such as rubber and nylon. Regarding the flexibility of these resin materials, when applied to various parts, the materials are required to have good stress absorption during stress and to be less prone to cracking or delamination. However, after the material is subjected to stress forming, the material is easy to rebound and restore to the original shape after stress is released, in addition, the size expansion and shrinkage are large in the heating process, the size stability is poor, and under the condition that the size stability is required in the electronic industry such as a PCB (printed Circuit Board), the alignment difficulty between a fine line and an interlayer is very large, so that the material cannot be used independently.

With the development of electronic products towards the direction of light, thin, short, small and multifunctional integration and the increasingly insufficient cruising ability of batteries, the three-dimensional installation of PCBs and electronic components is more and more required. At present, in order to realize three-dimensional installation, a rigid-flex PCB (printed circuit board) technical route is mostly adopted. The traditional rigid-flexible PCB is characterized in that one PCB printed circuit board comprises one or more rigid zones and one or more flexible zones, the rigid PCB and the flexible PCB are sequentially laminated together, and the rigid PCB and the flexible PCB are electrically connected through metallized holes. The rigid-flex PCB not only can provide due supporting function for the rigid printed board, but also has the flexibility of the flexible board, and can meet the requirement of three-dimensional assembly. However, the rigid-flex PCB processing technology is complex and difficult, such as: the rigid PCB needs to be partially hollowed out and then is bonded with the FPCB through pressing, meanwhile, a non-glue-flowing bonding material is needed to be used between the partially hollowed rigid PCB and the flexible FPCB, and the material has a narrow laminated window and high pressing difficulty and is easy to have the defects of bubbles, white spots and the like; in addition, the Polyimide (PI) film of the Flexible Copper Clad Laminate (FCCL) has large surface inertness and low adhesion with hard boards and most of adhesive materials, while the rubber and acrylic resin system can be well adhered with the PI film, but the heat resistance, the dimensional stability and other properties are not good, so that the product reliability has hidden danger, the yield is low, and the cost is high. Many soft and hard combined PCBs are used in the field of static bending, so-called static bending, that is, only one time of bending is needed during installation, or after one-time bending forming, the bending area does not need to swing, that is, the PCB is static during working and does not swing back and forth like a printer laser head; however, even in these static bending fields, the conventional rigid PCB cannot meet the bending forming and using requirements.

Therefore, in the field of electronic products such as a plurality of static bending installation PCBs and the like, the material is required to have the processing capacity of one-time impact forming, impact stress can be well borne in the impact forming process, cracking and layering are avoided, various three-dimensional bending or concave-convex shapes are punched for fixing, and the subsequent installation and use of the PCBs are facilitated.

Disclosure of Invention

The invention aims to provide a novel thermosetting resin composition capable of being used for a copper-clad plate, the rigid and hard copper-clad plate which is made of the thermosetting resin composition and does not need to use a flexible plate (FCCL), and a PCB which is made of the copper-clad plate and can be statically bent and used for three-dimensional mounting.

The purpose of the invention can be realized by the following technical scheme.

One aspect of the present invention provides a thermosetting resin composition comprising: a thermosetting resin; a curing agent; and the toughening material comprises at least one of rubber, phenoxy resin, polyvinyl butyral (PVB), nylon, nano particles and an olefinic block copolymer, wherein the curing agent accounts for 1-50 parts by weight and the toughening material accounts for 20-60 parts by weight based on 100 parts by weight of the thermosetting resin.

In certain embodiments, the thermosetting resin comprises an epoxy resin, preferably a multifunctional epoxy resin; the curing agent comprises at least one of phenolic resin, amine compounds, acid anhydride, imidazole compounds, sulfonium salt, dicyandiamide and active ester.

In certain embodiments, the epoxy equivalent ratio of the epoxy resin to the hydroxyl equivalent ratio of the phenolic resin is 1:1 to 0.95; or the equivalent ratio of epoxy resin to amino group is 1: 0.6 to 0.4.

In certain embodiments, the rubber comprises a core-shell structured rubber; the nanoparticles comprise SiO₂，TiO₂Or CaCO₃Nanoparticles; the olefinic block copolymer includes a block copolymer of polymethacrylic acid, butadiene and styrene.

In some embodiments, the thermosetting resin composition further comprises 5 to 50 parts by weight of a solvent to form a dope of the resin composition (dope viscosity of 300-; preferably, the solvent includes at least one of Dimethylformamide (DMF), ethylene glycol methyl ether (MC), propylene glycol methyl ether (PM), Methyl Ethyl Ketone (MEK), propylene glycol methyl ether acetate (PMA), cyclohexanone, toluene, xylene.

The invention also provides a bending copper-clad plate, which comprises a copper foil and a base cloth impregnated with the thermosetting resin composition adhered on the copper foil, wherein the thermosetting resin composition is the thermosetting resin composition, and the base cloth is preferably glass fiber cloth or non-woven cloth.

In certain embodiments, the copper clad laminate has a flexural modulus of elasticity >10GPa, a peel strength between 60-200 ℃ of greater than 1.0N/mm, and, after removal of the copper foil, a maximum stress value of greater than 400Mpa and a strain to failure value of greater than 4%.

In some embodiments, the copper clad laminate is obtained by hot-pressing a semi-cured thermosetting resin composition impregnated or coated base fabric (prepreg) on a copper foil at a maximum temperature of 180-.

The invention also provides a bendable printed circuit board, which comprises the copper-clad plate; preferably, the area of the printed circuit board to be bent is only a simple circuit without a via hole.

In certain embodiments, the printed wiring board is stamped and formed.

The invention may have at least one of the following advantages:

1. the copper-clad plate can be plastically deformed within a certain temperature range under the action of mechanical force, and the shape generated by the original deformation can not be changed when the mechanical force is released and the copper-clad plate is recovered to the normal temperature, so that the copper-clad plate can be fixedly formed, namely, the copper-clad plate has certain rigidity to bear the stress action, generates deformation without breakage, and has deformation strain.

2. The production process flow of the copper-clad plate is simple, a flexible plate (FCCL) is not needed, the efficiency is improved, and the cost is saved.

3. The copper-clad plate can be used for producing a Printed Circuit Board (PCB) according to the traditional PCB manufacturing process, and the PCB for static bending and three-dimensional installation can be obtained through punch forming treatment.

Drawings

Fig. 1 shows five types of stress-strain curves.

FIG. 2 shows a typical stress (F) -strain (L) curve of the CCL of the present invention obtained according to tensile strength and tensile modulus test method.

Fig. 3 shows a bending radius of the PCB formed by bending in embodiment 1 of the present application.

Fig. 4 shows a bending angle of the PCB bent and formed in embodiment 1 of the present application.

Detailed Description

The present invention surprisingly found that: the thermosetting resin composition containing the toughening material is used for impregnating base fabrics such as glass fiber cloth and the like to prepare a prepreg, the prepreg is laminated and compounded with the copper foil, and the copper clad laminate with rigid and tough (or hard and tough) characteristics can be obtained after complete curing.

The stress-strain curve for a material with hard and tough characteristics is shown as curve 2 in fig. 1. In fig. 1, the material properties represented by the curves 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 thermosetting resin composition, a rigid and hard copper-clad plate made of the thermosetting resin composition, and a printed wiring board (PCB) made of the copper-clad plate. Various aspects of the invention are described in detail below.

Thermosetting resin composition

One aspect of the present invention provides a thermosetting resin composition comprising: a thermosetting resin; a curing agent; and a toughening material.

In certain embodiments, the thermosetting resin may include epoxy resins, phenolic resins, polyimide resins, urea-formaldehyde resins, melamine resins, unsaturated polyesters, polyurethane resins, and the like, with epoxy resins being preferred.

Specific examples of the epoxy resin may include: bisphenol a epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, aralkyl epoxy resin, phenol novolac epoxy resin (phenol novolac type epoxy resin), alkyl novolac epoxy resin (alkyl novolac type epoxy resin), bisphenol epoxy resin, naphthalene epoxy resin, dicyclopentadiene epoxy resin, epoxy compound obtained by condensing phenol compound and aromatic aldehyde having a phenolic hydroxyl group, triglycidyl isocyanurate, alicyclic epoxy resin, and the like. These epoxy resins may be used alone or in combination of two or more kinds depending on the case.

Preferably, the epoxy resin is a polyfunctional epoxy resin containing two or more epoxy groups (preferably three or more epoxy groups) in one molecule. As such an epoxy resin, commercially available epoxy resins, for example, JER1003 (manufactured by Mitsubishi chemical corporation, 7 to 8 methyl groups, bifunctional, molecular weight 1300), EXA-4816 (manufactured by Diegon, molecular weight 824, majority methyl groups, bifunctional), YP50 (manufactured by Nichikomo Metal chemical corporation, molecular weight 60000 to 80000, majority methyl groups, bifunctional), DER593 (manufactured by Dow chemical corporation, polyfunctional epoxy resin), EPIKOTE 157 (manufactured by Resolution, polyfunctional epoxy resin), and the like can be used.

In certain embodiments, the curing agent in the thermosetting resin composition may be determined according to the kind of the thermosetting resin. For the epoxy resin, the curing agent may include at least one of a phenol resin, an amine-based compound, an acid anhydride, an imidazole-based compound, a sulfonium salt, dicyandiamide, and an active ester.

The active ester curing agent is obtained by reacting a phenolic compound, a difunctional carboxylic aromatic compound or an acid halide and a monohydroxy compound which are connected through an aliphatic cyclic hydrocarbon structure. The dosage of the difunctional carboxylic acid aromatic compound or the acid halide is 1mol, the dosage of the phenolic compound connected through the aliphatic cyclic hydrocarbon structure is 0.05-0.75 mol, and the dosage of the monohydroxy compound is 0.25-0.95 mol. The active ester curing agent may include an active ester of the formula:

wherein X in the formula 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 0.25-1.25.

In certain embodiments, the curing agent is preferably a phenolic resin, an amine-based compound, an imidazole-based compound, and dicyandiamide. These curing agents may be used alone or in combination of two or more. Specific curing agents may include: phenolic resins (e.g., phenol novolac resins, cresol novolac resins, etc.); diamino Diphenyl Sulfone (DDS); dicyandiamide (DICY); dimethylimidazole (2-MI), and the like.

The curing agent is generally used in an amount of 1 to 50 parts by weight, for example, 1 to 40 parts by weight, or 1 to 30 parts by weight, relative to 100 parts by weight of the thermosetting resin. For epoxy resins, the amount of curing agent can be controlled such that the ratio of epoxy equivalents of the epoxy resin to hydroxyl equivalents of the phenolic resin is 1:1 to 0.95; or the equivalent ratio of epoxy resin to amino group is 1: 0.6 to 0.4.

In certain embodiments, the toughening material comprises at least one of rubber, phenoxy resin, polyvinyl butyral (PVB), nylon, nanoparticles, olefinic block copolymers. These toughening materials are selected according to compatibility with thermosetting resins such as epoxy resins, toughening effect (to achieve a corresponding stress strain requirement (described later)), and the like. Among them, the rubber is preferably a rubber having a core-shell structure, such as a methylmethacrylate-butadiene-styrene (MBS) core-shell type copolymer resin, a rubber-epoxy type core-shell resin, and the like, and representative thereof are commercially available including M-521, MX-395, and the like, from Bell-source Japan. The nanoparticles comprise SiO₂，TiO₂Or CaCO₃Nanoparticles and the like, the particle diameter of which is generally 10 to 500 nm. Olefinic block copolymers are block copolymers formed by the copolymerization of different types of olefins, for example, block copolymers of polymethacrylic acid, butadiene and styrene.

The toughening materials may be used alone or in combination of two or more. For example, the nanoparticles can be used in combination with another toughening material (e.g., core shell rubber, phenoxy resin, PVB, nylon, olefinic block copolymer, or mixtures thereof) in a weight ratio of 1:10 to 2: 1.

For good toughening, the total amount of toughening materials used is generally from 20 to 60 parts by weight, for example, from 20 to 50 parts by weight, or from 30 to 60 parts by weight, per 100 parts by weight of the thermosetting resin.

In certain embodiments, the thermosetting resin composition may further comprise an amount of solvent to formulate the above components into a glue. The solvent is generally used in an amount of 5 to 50 parts by weight, for example, 10 to 50 parts by weight, 20 to 50 parts by weight, etc., relative to 100 parts by weight of the thermosetting resin, to form a dope having a viscosity of 300-600 cPa.s.

The solvent may include at least one of 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.

In certain embodiments, the thermosetting resin composition may further contain fillers or auxiliaries and the like, such as flame retardants, leveling agents, colorants, dispersants, coupling agents, foaming agents and the like, within a range in which the effects of the present invention are not lost. Wherein the flame retardant can be one or more of organic flame retardant such as tetrabromobisphenol A, DOPO and phosphate.

Copper-clad plate

The invention also provides a bendable copper-clad plate, which comprises a copper foil and base cloth which is adhered on the copper foil and is impregnated by the thermosetting resin composition.

In certain embodiments, the base fabric comprises a fiberglass cloth or a non-woven fabric. The glass fiber cloth can be selected from 7628, 2116, 1080, 106, 1037, 1027, 1017 and other specifications.

In some embodiments, the copper foil can be selected from 1OZ, 1/2OZ, 1/3OZ, and the like.

In the present invention, the above-mentioned stress strain value is measured by the following tensile strength and tensile modulus test methods.

The method for testing the tensile strength and the tensile modulus of the material comprises the following steps:

A. test devices and/or materials

-material testing machine

A tensile compression tester according to ISO3384 standard, which can operate the tensile clamp at a stable speed. The error of the load measurement system does not exceed +/-1%.

An etching system capable of completely removing the metal-clad foil.

Vernier calipers (to the nearest 0.02mm) or micrometers (to the nearest 0.002mm)

-test sample

(1) Size and shape

The dimensions of the test specimen are 250mm × 25mm, the thickness of the test specimen is preferably 0.4mm, and the edge of the test specimen should be free from defects such as cracks, delamination and the like, otherwise, the test specimen is ground by sand paper or an equivalent tool (the edge is not formed into a round angle).

(2) Quantity and sampling

When the coefficient of variation is less than 5%, ten specimens, five pieces in the longitudinal direction and five pieces in the transverse direction (cut out on the whole sample plate or platelet) are used for each batch. When the dispersion coefficient is greater than 5%, the number of samples in each direction cannot be less than 10, and 10 valid samples are guaranteed.

(3) All the metal covering layer is etched and removed by an etching method.

B. Tensile test procedure

Measuring the dimensions of the sample

The width and thickness of the test specimen were measured and recorded, with the width being accurate to 0.02mm and the thickness being accurate to 0.002 mm.

-measuring

(1) And clamping the sample to make the center line of the sample consistent with the alignment center line of the upper clamp and the lower clamp.

(2) The distance between the upper clamp and the lower clamp is adjusted to be 125mm +/-0.5 mm.

(3) The loading speed was 12.5 mm/min.

(4) The tensile modulus calculation was set at a fraction between 0.05% and 0.25% strain.

(5) The test was performed and stress-strain curves were plotted.

(6) Specimens with significant internal defects should be discarded.

(7) The specimen should be rejected if the specimen breaks in the fixture or if the specimen breaks less than 10mm from the clamped position.

C. Computing

The tensile strength of each specimen was calculated as follows

In the formula:

τ T: tensile strength, MPa

F: breaking or maximum load, N

b: width of specimen in mm

d: thickness of the sample in mm

The tensile modulus of elasticity of each specimen was calculated as follows

In the formula:

E_t: tensile modulus of elasticity, MPa

σ': tensile stress value measured at 0.25% ε of Strain ε ″, MPa

σ': tensile stress value measured at 0.05% ε strain, (. epsilon.'), MPa

-calculating the average tensile strength and the tensile modulus of elasticity in MPa.

FIG. 2 shows a typical stress-strain curve of the CCL of the present invention obtained by the above-mentioned tensile strength and tensile modulus test method. 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 of more than 400MPa and a fracture strain value of more than 4%.

In certain embodiments, the copper-clad plate of the present invention can be made according to the following process.

Preparation of prepregs

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

-manufacturing copper clad laminate

And laminating the cut prepreg on a copper foil, carrying out hot pressing at the heating rate of 1-3 ℃/min, keeping the pressure at the maximum of 300-500PSI, and keeping the temperature at the maximum of 180-200 ℃ for 30-120 minutes (such as 60-120 minutes) to obtain the copper-clad plate.

In certain embodiments, the copper clad laminate of the present invention can be stamped and formed in a die. Preferably, the temperature for stamping is selected within. + -. 30 ℃ of the Tg value of the copper clad laminate (thermosetting resin composition).

Printed Circuit Board (PCB)

In another aspect of the invention, the PCB capable of being bent and formed comprises the copper-clad plate.

In some embodiments, the area of the PCB that needs to be bent is simply a trace, without vias.

In certain embodiments, the PCB is stamped and formed.

In certain embodiments, the PCB is stamped and formed to create the required steps to accommodate three-dimensional mounting.

In certain embodiments, the stamping forming of the PCB comprises the steps of: (1) firstly, heating a PCB to 60-200 ℃; (2) after the PCB is heated to a stable temperature, the PCB is put into a die stamping machine and is pressed for more than 2 seconds under the pressure of 100-. The mold may be heated or not heated as appropriate, and for example, the mold temperature may be normal temperature (20 to 35 ℃) or heated to 100 ℃ or lower.

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

Example 1:

1. glue solution preparation: 5 parts by weight of rubber (Japanese Brillouin M-521), 10 parts by weight of core-shell rubber (Japanese Brillouin MX-395) and 20 parts by weight of nano SiO₂The adhesive is prepared by mixing (winning Nanopol A710) serving as a toughening material with 100 parts by weight of multifunctional epoxy resin (DOW chemical DER593 resin), adding 10 parts by weight of Diamino Diphenyl Sulfone (DDS), 0.1 part by weight of dimethyl imidazole (2-MI) and a proper amount of DMF (dimethyl formamide) organic solvent, and controlling the viscosity of the adhesive to be 300-600 cPAS.

2. Manufacturing a prepreg: the 2116 glass fiber cloth is soaked by the glue for gluing, and then the glass fiber cloth is put into an oven for heating and baking for 3 to 10 minutes at the temperature of 100-.

3. Manufacturing a copper-clad plate: selecting 1OZ copper foil, combining with the prepreg, placing into a laminating machine, heating at a rate of 1-3 ℃/min, pressing at a maximum pressure of 300-.

4. Manufacturing a PCB: the copper-clad plate is used for producing the PCB according to the traditional PCB manufacturing process, and the PCB is only provided with a simple circuit in an area which needs to be bent and formed locally.

5. Bending and forming the PCB: (1) firstly, heating the PCB to 60 ℃; (2) heating the PCB to stabilize the temperature, putting the PCB into a stamping machine, pressing the PCB for 5 seconds at 10000N pressure, then opening the die, and taking out the PCB. The bending radius and bending angle of the resulting PCB are shown in fig. 3 and 4.

6. The PCB is tested for appearance, short circuit or open circuit, thermal shock, reflow soldering, ion migration resistance (CAF) and other related characteristics, and the stress strain value is determined according to the tensile strength and tensile modulus test method described in the specification.

Example 2:

except for the following glue solution configuration, the copper clad laminate and the PCB were manufactured in the same manner as in example 1, and the corresponding performances were tested.

Glue solution preparation: selecting 30 parts by weight of phenoxy resin (53 BH35 of HEXION company) as a toughening material, mixing with 100 parts by weight of multifunctional epoxy resin (EPIKOTE 157 resin of Resolution company), adding 2.5 parts by weight of Dicyandiamide (DICY), 0.1 part by weight of 2-methylimidazole and a proper amount of DMF organic solvent, preparing into glue solution, and controlling the viscosity of the glue solution to be 300-600 cPAS.

Example 3:

Glue solution preparation: 30 parts of PVB (U.S. Konno B90) and 6 parts of nano SiO₂(winning Nanopolo A710) and 10 parts by weight of a block copolymer (Achima)

M52N) as toughening material, mixing with 100 weight parts of multifunctional epoxy resin (DER 593 resin of DOW chemical company) and 20-30 weight parts of phenolic resin, adding 1 weight part of dicyandiamide and 0.1 weight part of 2-MI, and proper amount of MC and PM organic solvent, preparing into glue solution, and controlling the viscosity of the glue solution at 300 ℃600 cPAS.

Example 4:

Glue solution preparation: the preparation method comprises the steps of selecting 20 parts by weight of nylon (DuPont ST801A in America) and 10 parts by weight of nano SiO2 (Nanopol A710 in winning), mixing the nylon and the nano SiO2 with 100 parts by weight of multifunctional epoxy resin (DOW chemical DER593 resin), adding phenolic resin and a proper amount of MEK organic solvent according to the epoxy equivalent and hydroxyl equivalent of 1:1, preparing glue solution, and controlling the viscosity of the glue solution to be between 300 and 600 cPAS.

Example 5:

Glue solution preparation: selecting 25 weight parts of block copolymer (Acoma)

M52N) and 8 parts by weight of nano SiO₂(winning creation A710) is used as a toughening material, is mixed with 100 weight parts of multifunctional epoxy resin, is added with 8 to 10 weight parts of DDS curing agent, 0.1 weight part of 2-MI accelerant and a proper amount of DMF organic solvent, is prepared into glue solution, and the viscosity of the glue solution is controlled between 300 and 600 cPAS.

Example 6:

Glue solution preparation: selecting 20 weight parts of phenoxy resin (Nissie iron chemical ERF-001) and 8 weight parts of nano SiO₂(winning Nanopol A710) is used as a toughening material, and is mixed with 100 parts by weight of multifunctional epoxy resin (DOW chemical DER593 resin), phenolic resin and a proper amount of MEK organic solvent are added according to the epoxy equivalent and hydroxyl equivalent of 1:1 to prepare glue solution, and the viscosity of the glue solution is controlled to be 300-600 cPAS.

Comparative example 1:

Glue solution preparation: selecting 100 weight parts of multifunctional epoxy resin (DOW chemical DER593 resin), adding 2-3 weight parts of dicyandiamide, 0.1 weight part of 2-MI and a proper amount of DMF organic solvent to prepare glue solution, and controlling the viscosity of the glue solution to be between 300 and 600 cPAS.

Comparative example 2:

Glue solution preparation: 5-10 parts by weight of nitrile-butadiene rubber and 100 parts by weight of multifunctional epoxy resin are mixed, 3 parts by weight of dicyandiamide, 0.1 part by weight of 2-MI and a proper amount of DMF organic solvent are added to prepare a glue solution, and the viscosity of the glue solution is controlled between 300 and 600 cPAS.

The test results are given in the following table:

reflow test method (refer to JEDEC Standard 22-A113D)

(1) The heating rate is as follows: 3 ℃/sec Max (recommended)

(2)150 ℃ and 260 ℃ for more than 150 sec.

(3) The maximum temperature is maintained at 260 ℃ for more than 20sec, and the maximum temperature is maintained at 25-260 ℃ for 3-5 min.

T288 test method (test method of base Material for reference printed Board-method 2.4.24.1 delamination time (TMA method))

The temperature is raised to 288 ℃ from the initial temperature which is not higher than 35 ℃, the heating rate is 10 ℃/min, the temperature is kept unchanged after the temperature is raised to 288 ℃, the timing is started from the time when the temperature reaches 288 ℃ until the sample is layered at the temperature, and the time that the sample is kept not layered at the temperature of 288 ℃ is recorded, namely the layering time of T288.

Other performance tests may refer to IPC related test methods.

While the invention has been described with reference to specific embodiments, it will be understood by those skilled in the art that various changes and modifications may be made therein without departing from the spirit and scope of the invention as defined in the appended claims.

The present invention is illustrated in detail by the examples described above, but the present invention is not limited to the details described above, i.e., it is not intended that the present invention be implemented by relying on the details described above. It should be understood by those skilled in the art that any modification of the present invention, equivalent substitutions of the raw materials of the product of the present invention, addition of auxiliary components, selection of specific modes, etc., are within the scope and disclosure of the present invention.

Claims

1. The copper-clad plate capable of being bent and formed is characterized by comprising a copper foil and a thermosetting resin composition impregnated base cloth adhered to the copper foil, wherein the thermosetting resin composition comprises: a thermosetting resin; a curing agent; and a toughening material, wherein the curing agent is 1-50 parts by weight and the toughening material is 20-60 parts by weight based on 100 parts by weight of the thermosetting resin, and the toughening material comprises a combination of nanoparticles and at least one of rubber, phenoxy resin, polyvinyl butyral, nylon and olefinic block copolymer;

the nanoparticles are used in combination with at least one of rubber, phenoxy resin, polyvinyl butyral, nylon, olefinic block copolymers in a weight ratio of 1:10 to 2:1,

wherein the rubber comprises a core-shell structured rubber; the nanoparticles comprise SiO₂，TiO₂Or CaCO₃Nanoparticles; the olefinic block copolymer includes a block copolymer of polymethacrylic acid, butadiene and styrene.

2. The copper-clad plate of claim 1, wherein the thermosetting resin comprises an epoxy resin; the curing agent comprises at least one of phenolic resin, amine compound, acid anhydride, sulfonium salt and active ester.

3. The copper-clad plate capable of being bent and formed according to claim 2, wherein the epoxy resin is a multifunctional epoxy resin.

4. The copper-clad plate capable of being bent and formed according to claim 2, wherein the ratio of epoxy equivalent of the epoxy resin to hydroxyl equivalent of the phenolic resin is 1:1 to 0.95; or the equivalent ratio of epoxy resin to amino group is 1: 0.6 to 0.4.

5. The copper-clad plate of claim 2, wherein the curing agent comprises at least one of imidazole compound and dicyandiamide.

6. The copper-clad plate capable of being bent and formed according to claim 1, wherein the thermosetting resin composition further comprises 5-50 parts by weight of a solvent to form a glue solution of the resin composition, and the viscosity of the glue solution is 300-600 cPa-s.

7. The copper-clad plate of claim 6, wherein the solvent comprises at least one of dimethylformamide, ethylene glycol methyl ether, propylene glycol methyl ether, methyl ethyl ketone, propylene glycol methyl ether acetate, cyclohexanone, toluene and xylene.

8. The copper-clad plate capable of being bent according to claim 1, wherein the base fabric is glass fiber cloth or non-woven fabric.

9. The copper-clad plate capable of being bent according to claim 1, wherein the copper-clad plate has an elastic bending modulus of more than 10GPa, a peel strength between 60 and 200 ℃ of more than 1.0N/mm, and a maximum stress value of more than 400MPa and a fracture strain value of more than 4% after the copper foil is removed.

10. The copper-clad plate according to claim 1, wherein the copper-clad plate is obtained by hot-pressing a prepreg on a copper foil at a maximum temperature of 180-200 ℃ for 30-120 minutes, wherein the prepreg is obtained by heating a base fabric impregnated or coated with the thermosetting resin composition at 200 ℃ for 1-10 minutes.

11. A bendable printed wiring board, which comprises the bendable copper-clad plate according to any one of claims 1 to 10.

12. The printed wiring board of claim 11, wherein the area of the printed wiring board that requires bending is simply a circuit without vias.

13. The printed wiring board of claim 11, wherein the printed wiring board is stamped and formed.