阅读说明：本技术 一种用于金属基板的树脂组合物、包含其的树脂胶液以及金属基覆铜箔层压板 (Resin composition for metal substrate, resin glue solution containing resin composition and metal-based copper-clad laminate ) 是由 佘乃东 黄增彪 于 2019-04-22 设计创作，主要内容包括：本发明提供了一种用于金属基板的树脂组合物、包含其的树脂胶液以及金属基覆铜箔层压板,以树脂组合物总重量为100％计,包括如下组分：主体树脂5-40％和导热填料60-95％；其中,以主体树脂总重量为100％计,所述主体树脂包括柔性环氧树脂60-90％以及酚氧树脂10-40％,其中,所述柔性环氧树脂具有如式I所示结构。本发明提供的树脂组合物模量低,可以使冷热冲击产生的应力得到缓和,可以承受超过1000次的冷热循环实验。(The invention provides a resin composition for a metal substrate, a resin glue solution containing the resin composition and a metal-based copper-clad laminate, wherein the resin composition comprises the following components in percentage by weight of 100 percent of the total weight of the resin composition: 5-40% of main resin and 60-95% of heat-conducting filler; the main resin comprises 60-90% of flexible epoxy resin and 10-40% of phenoxy resin, wherein the total weight of the main resin is 100%, and the flexible epoxy resin has a structure shown in a formula I. The resin composition provided by the invention has low modulus, can relieve stress generated by cold and hot impact, and can bear more than 1000 times of cold and hot cycle experiments.)

1. A resin composition for a metal substrate, comprising the following components, based on 100% by weight of the total resin composition: 5-40% of main resin and 60-95% of heat-conducting filler;

wherein, the main resin comprises 60-90% of flexible epoxy resin and 10-40% of phenoxy resin, wherein the total weight of the main resin is 100%;

wherein the flexible epoxy resin has a structure as shown in formula I:

wherein R is selected from linear or branched alkylene of C2-C20, -CO-R₁-CO-or-R₂-O-R₃-O-R₄-；

Wherein R is₁Selected from C2-C20 linear or branched alkylene, R₂、R₄Each independently selected from C1-C10 linear or branched alkylene, R₃Selected from C2-C15 linear or branched alkylene, C6-C17 cycloalkyl or

n₁indicating an average repeat unit of 4 to 10.

2. The resin composition for metal substrates according to claim 1, wherein R is₃Selected from the group consisting of C2-C15 straight or branched chain alkylene, C6-C17 aliphatic cycloalkyl, ethyleneoxyethylene, di (ethyleneoxy) ethylene, tri (ethyleneoxy) ethylene, propyleneoxypropylene, di (propyleneoxy) propylene, tri (propyleneoxy) propylene, tetra (propyleneoxy) propylene, butyleneoxybutylene, di (butyleneoxy) butylene, tri (butyleneoxy) butylene, or tetra (butyleneoxy) butylene.

3. The resin composition for a metal substrate according to claim 1, wherein the host resin further comprises a biphenyl epoxy resin;

preferably, the biphenyl epoxy resin is added in an amount of 1-20% based on 100% of the total weight of the host resin.

4. The resin composition for a metal substrate according to any one of claims 1 to 3, wherein the resin composition further comprises a curing agent;

preferably, the addition amount of the curing agent is 1-10% based on the total weight of the main resin as 100%;

preferably, the curing agent is an amine curing agent;

preferably, the curing agent comprises any one or a combination of at least two of ethylenediamine, diethylenetriamine, triethylene tetramine, tetraethylene pentamine, isophorone diamine, m-phenylene diamine, m-aminomethane, diamino diphenyl sulfone, dicyandiamide, diamino dicyclohexyl methane, methyl cyclopentyl diamine, diamine methyl cyclohexyl diamine or diamino diphenyl methane;

preferably, the weight average molecular weight of the phenoxy resin is 30000-65000.

5. The resin composition for a metal substrate according to any one of claims 1 to 4, wherein the thermally conductive filler comprises any one or a combination of at least two of aluminum nitride, boron nitride, aluminum oxide, silicon carbide, zinc oxide, or carbon nanotubes, and further preferably any one or a combination of at least two of boron nitride, aluminum oxide, or silicon carbide.

6. The resin composition for a metal substrate according to any one of claims 1 to 5, wherein the resin composition further comprises a curing accelerator;

preferably, the curing accelerator is added in an amount of 0.1 to 2% based on 100% by weight of the total host resin.

7. A resin coating solution obtained by dissolving or dispersing the resin composition for metal substrates according to any one of claims 1 to 6 in a solvent.

8. An adhesive film comprising the resin composition for metal substrates according to any one of claims 1 to 6.

9. A metal-based copper clad laminate comprising a metal substrate laminated together from bottom to top, a thermally conductive insulating adhesive layer and a copper foil prepared from the resin composition for metal substrates according to any one of claims 1 to 6.

10. The metal-based copper-clad laminate according to claim 9, wherein the metal substrate comprises any one of an aluminum substrate, a copper substrate, an iron substrate, or a steel substrate;

preferably, the thickness of the metal substrate is 0.3-5.0 mm;

preferably, the thickness of the heat-conducting insulating bonding layer is 0.04-0.20 mm;

preferably, the copper foil is an electrolytic copper foil or a rolled copper foil;

preferably, the copper foil has a thickness of 0.012-0.210 mm.

Technical Field

The invention belongs to the field of laminated plates, and relates to a resin composition for a metal substrate, a resin glue solution containing the resin composition and a metal-based copper-clad laminated plate.

Background

With the mass production of electronic information products and the trend toward light, thin, small and multifunctional designs, the printed circuit board, which is the main support of electronic components, has been improved to provide high-density wiring, thin shape, fine aperture and high heat dissipation performance. Under this background, a metal-based copper clad laminate with high heat dissipation has been produced. When the metal-based copper foil-clad laminate is applied to high-power LED illumination, the thermal expansion coefficient of a high-power chip is far smaller than that of a metal substrate, and the stress difference required to be released by cold and hot impact is large, so that the weakest welding point or copper foil circuit is cracked, and the reliability is influenced. The general metal-based copper-clad laminate is formed by bonding a metal substrate, a heat-conducting insulating bonding layer and a copper foil, and when the heat-conducting insulating bonding layer exists, the stress generated by cold and hot shock can be relieved to a certain extent, but the requirement on reliability cannot be met. CN104708869A discloses a high-thermal-conductivity aluminum-based copper-clad plate and a preparation method thereof, wherein the copper-clad plate comprises a copper foil layer, a high-thermal-conductivity insulating layer and an aluminum plate which are sequentially arranged from inside to outside, the high-thermal-conductivity insulating layer is filled with alumina fibers, and the alumina fibers are prepared by micro-arc oxidation; the patent improves the heat dissipation capacity of the aluminum-based copper-clad plate and the reliability of the aluminum-based copper-clad plate, but does not solve the problem of how to solve the damage of the stress generated by cold and hot impact on a welding spot or a copper foil circuit. CN103468188A discloses a magnetic composite glue, which comprises 1-200 parts by weight of magnetic conductive powder, 10 parts by weight of resin, 1 part by weight of calcium carbonate, 0.1-1 part by weight of active dispersant and other additives, and 0.1-1 part by weight of latent curing accelerator, or comprises 1000-2000 parts by weight of magnetic conductive powder, 10 parts by weight of rubber, 1 part by weight of calcium carbonate, 1-5 parts by weight of active dispersant and other additives and 1-5 parts by weight of latent curing accelerator, the stress generated to a contact object is very small when the contact object is subjected to cold and hot shock cycles at the temperature of between 40 ℃ below zero and 125 ℃ after being solidified, the flaky substance with the strength of 1.5N cannot crack, and the solidified strength can still bear the destructive power of more than 50N after 200 cold and hot shock cycles at the temperature of between 40 ℃ below zero and 85 ℃. But whether it can be applied to the field of laminates is yet to be investigated.

In order to improve the flexibility and flexibility of the adhesive film material, a small amount of thermoplastic resin, rubber toughened epoxy resin or other toughened and modified epoxy resin is added into main resin of the adhesive film material, and the resin composition cannot be used as a heat-conducting insulating bonding layer of a metal-based copper clad laminate due to low thermal conductivity and poor cold and heat shock resistance.

Therefore, it is required to develop a thermally conductive resin composition that can be well resistant to thermal shock to be applied to a metal substrate.

Disclosure of Invention

The invention aims to provide a resin composition for a metal substrate, a resin adhesive solution containing the resin composition and a metal-based copper clad laminate. The resin composition provided by the invention can resist cold and hot shock changes, and can avoid the problem of cracks of welding spots or copper foil circuits caused by mismatching of thermal expansion coefficients of a chip and a substrate due to low modulus.

In order to achieve the purpose, the invention adopts the following technical scheme:

in a first aspect, the present invention provides a resin composition for a metal substrate, comprising the following components, based on 100% by weight of the total resin composition: 5-40% of main resin and 60-95% of heat-conducting filler.

Wherein, the main resin comprises 60-90% of flexible epoxy resin and 10-40% of phenoxy resin, wherein the total weight of the main resin is 100%.

Wherein the flexible epoxy resin has a structure as shown in formula I:

wherein R is selected from linear or branched alkylene of C2-C20, -CO-R₁-CO-or-R₂-O-R₃-O-R₄-；

Wherein R is₁Selected from C2-C20 linear or branched alkylene, R₂、R₄Each independently selected from C1-C10 linear or branched alkylene, R₃Selected from C2-C15 linear or branched alkylene, C6-C17 cycloalkyl orR₅Selected from C1-C10 linear or branched alkylene groups, and m is an integer from 1 to 10, such as 2, 3, 4, 5, 6, 7, 8, 9, etc.

n₁Meaning an average repeat unit of 4 to 10, e.g., 5, 6, 7, 8, 9, etc.

The C2-C20 can be C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18, C19 and the like.

The C1-C10 can be C2, C3, C4, C5, C6, C7, C8, C9 and the like.

The C2-C15 can be C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14 and the like.

The C6-C17 can be C7, C8, C9, C10, C11, C12, C13, C14, C15, C16 and the like.

In the invention, the main resin comprises the flexible epoxy resin with a specific structure, the flexible epoxy resin provided by the invention can ensure that the finally obtained resin composition has a lower modulus, and the lower modulus can well alleviate stress generated by cold and hot impact, thereby avoiding the problem of cracks of welding spots or copper foil circuits caused by mismatching of thermal expansion coefficients of a chip and a substrate.

Meanwhile, the main resin comprises the phenoxy resin, and the use of the phenoxy resin can avoid the problem that the finally obtained adhesive film or RCC (resin coated copper foil) is sticky when the addition amount of the flexible epoxy resin is too high. In addition, different from other epoxy resins, the phenolic resin is added into the flexible epoxy resin, so that the modulus of the composition can be prevented from being greatly improved, and the lower modulus of the composition is a guarantee that the composition can well alleviate stress generated by cold and hot impact.

When the metal-based copper clad laminate in the prior art is applied (such as an LED illuminating lamp), if a chip, a welding point, a copper foil circuit, a heat conduction insulation bonding layer and a metal substrate are all in normal positions at normal temperature, but once the metal substrate, the heat conduction insulation bonding layer and the copper foil circuit are subjected to thermal expansion, the metal substrate, the heat conduction insulation bonding layer and the copper foil circuit are all deformed, and cracks are easily caused in the welding point or the copper foil circuit after the thermal expansion is cooled.

The host resin is 5-40%, such as 8%, 10%, 12%, 15%, 18%, 20%, 22%, 25%, 28%, 30%, 32%, 35%, 38%, etc.

In the present invention, said R₃Selected from the group consisting of C2-C15 straight or branched chain alkylene, C6-C17 aliphatic cycloalkyl, ethyleneoxyethylene, di (ethyleneoxy) ethylene, tri (ethyleneoxy) ethylene, propyleneoxypropylene, di (propyleneoxy) propylene, tri (propyleneoxy) propylene, tetra (propyleneoxy) propylene, butyleneoxybutylene, di (butyleneoxy) butylene, tri (butyleneoxy) butylene, or tetra (butyleneoxy) butylene.

Preferably, the host resin further includes a biphenyl epoxy resin.

Preferably, the biphenyl epoxy resin is added in an amount of 1-20%, such as 2%, 5%, 8%, 10%, 12%, 15%, 18%, etc., based on 100% of the total weight of the host resin.

The biphenyl epoxy resin is added to the host resin, and the use of the biphenyl epoxy resin can increase the heat resistance of the resin composition.

Preferably, the resin composition further comprises a curing agent.

Preferably, the curing agent is added in an amount of 1-10%, such as 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, etc., based on 100% by weight of the total host resin.

Preferably, the curing agent is an amine curing agent.

Preferably, the curing agent comprises any one or a combination of at least two of ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, isophoronediamine, m-phenylenediamine, m-aminomethane, diaminodiphenylsulfone, dicyandiamide, diaminodicyclohexylmethane, methylcyclopentadiene, diaminomethylcyclohexanediamine, or diaminodiphenylmethane.

The flexible epoxy resin is 60-90%, such as 62%, 65%, 68%, 70%, 72%, 75%, 78%, 80%, 82%, 85%, 88%, etc.

Preferably, the epoxy equivalent of the flexible epoxy resin is 300-500g/eq, such as 320g/eq, 340g/eq, 360g/eq, 380g/eq, 400g/eq, 410g/eq, 420g/eq, 430g/eq, 44g/eq, 450g/eq, 560g/eq, 470g/eq, 480g/eq, 490g/eq, and the like.

10-40% of the phenoxy resin, such as 12%, 15%, 18%, 20%, 22%, 25%, 28%, 30%, 32%, 35%, 38% and the like.

If the content of the phenoxy resin is too low, there is a problem that the tackiness of the adhesive film or the RCC (resin-coated copper foil) cannot be prevented. If the content of the phenoxy resin is too high, a dense protective film is formed on the surface of the resin composition during drying, which hinders volatilization of a solvent, causes bubbling on the surface of a glue film or RCC (resin-coated copper foil), and affects electrical insulation of the laminate.

Preferably, the weight average molecular weight of the phenoxy resin is 30000-65000, such as 35000, 40000, 45000, 50000, 55000, 60000, and the like.

When the weight average molecular weight of the phenol resin is too small, cracks are formed in the heat conductive insulating adhesive layer after lamination, which affects the use of the metal-based copper clad laminate, and when the weight average molecular weight is too large, there is a problem that the tackiness of the adhesive film or RCC (resin coated copper foil) cannot be prevented.

The thermally conductive filler is 60-95%, such as 62%, 65%, 68%, 70%, 72%, 75%, 78%, 80%, 82%, 85%, 88%, 90%, 92%, etc.

The content of the heat-conducting filler influences the heat conductivity and the modulus of the resin composition, and the reduction of the heat-conducting filler simultaneously reduces the heat conductivity and the modulus; the addition of the thermally conductive filler will also increase both the thermal conductivity and the modulus. In order to ensure proper thermal conductivity and low modulus of the resin composition, the content of the thermally conductive filler is 60 to 95%.

Preferably, the thermally conductive filler includes any one or a combination of at least two of aluminum nitride, boron nitride, aluminum oxide, silicon carbide, zinc oxide, or carbon nanotubes, and further preferably any one or a combination of at least two of boron nitride, aluminum oxide, or silicon carbide.

Preferably, the resin composition further includes a curing accelerator.

Preferably, the curing accelerator is added in an amount of 0.1 to 2%, such as 0.2%, 0.5%, 0.8%, 1.0%, 1.2%, 1.5%, 1.7%, etc., based on 100% by weight of the total host resin.

In the formulation of the present invention, in addition to the above components, some additives such as antifoaming agent, dispersant, antioxidant and the like may be added within the range not departing from the gist of the present invention.

In a second aspect, the present invention provides a resin paste obtained by dissolving or dispersing the resin composition for a metal substrate according to the first aspect in a solvent.

The solvent which can be selected by the invention comprises any one or the combination of at least two of dimethylformamide, butanone, acetone, cyclohexanone or toluene solvent.

In a third aspect, the present invention provides an adhesive film comprising the resin composition for a metal substrate of the first aspect.

In a fourth aspect, the invention provides a metal-based copper clad laminate, which comprises a metal substrate, a heat-conducting insulating bonding layer and a copper foil, wherein the metal substrate is laminated together from bottom to top, and the heat-conducting insulating bonding layer and the copper foil are prepared from the resin composition for the metal substrate.

The resin composition for the metal substrate is used as a heat-conducting insulating bonding layer and is positioned between the metal substrate and the copper foil, so that the stress action of the metal substrate caused by cold and heat shock can be well buffered, and the problem of cracks of a welding point or a copper foil circuit caused by the mismatching of the thermal expansion coefficients of a chip and the substrate is avoided.

Preferably, the metal substrate includes any one of an aluminum substrate, a copper substrate, an iron substrate, or a steel substrate.

Preferably, the thickness of the metal substrate is 0.3-5.0mm, such as 0.5mm, 1.0mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4.0mm, 4.5mm, and the like.

Preferably, the thickness of the thermally conductive and insulating adhesive layer is 0.04-0.20mm, such as 0.05mm, 0.08mm, 0.10mm, 0.12mm, 0.15mm, 0.18mm, and the like.

If the thickness of the thermal conductive insulating adhesive layer is too thin, stress due to thermal shock may not be well relaxed.

Preferably, the copper foil is an electrolytic copper foil or a rolled copper foil.

Preferably, the copper foil has a thickness of 0.012-0.210mm, such as 0.018mm, 0.035mm, 0.070mm, 0.105mm, 0.140mm, 0.175mm, and the like.

In the present invention, the metal-based copper clad laminate is not limited, and can be prepared, for example, by the following preparation method: dissolving or dispersing the resin composition in a solvent to obtain a resin glue solution with a certain solid content, then coating the resin glue solution on a base film (such as a release film), drying to obtain a semi-cured heat-conducting insulating glue film, then removing the base film, and then combining the heat-conducting insulating glue film with a copper foil and a metal substrate to carry out high-temperature lamination to obtain the metal-based copper-clad laminate.

The following preparation method can also be adopted: and coating resin glue solution with certain solid content on a copper foil, drying to obtain the copper foil with the semi-cured heat-conducting insulating bonding layer, and then laminating the copper foil with a metal substrate to obtain the metal-based copper-clad laminate.

Compared with the prior art, the invention has the following beneficial effects:

(1) in the invention, the main resin comprises flexible epoxy resin which can ensure that the finally obtained resin composition has lower modulus, and the lower modulus can well alleviate stress generated by cold and hot impact, thereby avoiding the problem of cracks of welding spots or copper foil circuits caused by the mismatching of the thermal expansion coefficients of the chip and the substrate;

(2) the main resin comprises phenoxy resin, and the use of the phenoxy resin can avoid the problem that the finally obtained adhesive film or RCC (resin-coated copper foil) is sticky when the addition amount of the flexible epoxy resin is too high; the composition is different from other epoxy resins, the phenolic resin is added into the flexible epoxy resin, so that the modulus of the composition can be prevented from being greatly improved, and the lower modulus of the composition is a guarantee that the composition can well alleviate stress generated by cold and hot impact;

(3) the resin composition for the metal substrate provided by the invention has a low modulus below 1500MPa, and can reach 300MPa at the lowest; the metal-based copper-clad laminate prepared by the resin composition has good heat resistance, good cold and heat impact resistance and high operability, wherein the heat resistance at 288 ℃ is more than 6min and can reach more than 10min at most, and the cold and heat cycle resistance is more than 1000 times and can reach more than 1500 times at most.

Drawings

Fig. 1 is a schematic cross-sectional view of a metal-based copper clad laminate and a chip in a normal temperature state.

Fig. 2 is a schematic cross-sectional view of a prior art metal-based copper clad laminate and chip in a state of being subjected to thermal expansion.

FIG. 3 is a schematic cross-sectional view of a prior art solder joint pull-apart after thermal expansion cooling of a metal-based copper clad laminate and a die.

Fig. 4 is a schematic cross-sectional view of the metal-based copper-clad laminate and chip of the present invention in a state of thermal expansion.

Wherein, 1-chip; 2-welding spots; 3-copper foil circuit; 4-heat conducting insulating adhesive layer; 5-metal substrate.

Detailed Description

The technical solution of the present invention is further explained by the following embodiments. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitations of the present invention.

As can be seen from fig. 1 to 3, when the metal-based copper clad laminate in the prior art is applied (for example, an LED lighting lamp), if the chip, the solder joint, the copper foil circuit, the heat conductive insulating adhesive layer, and the metal substrate are all in normal positions at normal temperature, the metal substrate, the heat conductive insulating adhesive layer, and the copper foil circuit are all deformed when subjected to thermal expansion, and cracks are likely to occur in the solder joint or the copper foil circuit after the thermal expansion is cooled. When the resin composition for a metal substrate provided by the present invention can be used as a heat conductive insulating adhesive layer, as can be seen from fig. 4, when subjected to thermal expansion, only the metal substrate and the heat conductive insulating adhesive layer are deformed due to the small modulus thereof, and the copper foil layer is hardly deformed, so that a solder joint or a copper foil circuit is not cracked after the thermal expansion is cooled.

The following examples and comparative examples relate to the following materials and the following trade mark information:

(A) flexible epoxy resin

A-1: trade model EXA-4850-150, epoxy equivalent 450g/eq, manufactured by Dainippon ink Co., Ltd.;

a-2: a commercial product model EXA-4850-1000, an epoxy equivalent of 350g/eq, manufactured by Dainippon ink Co., Ltd.;

a-3: the product was obtained under the trade name EXA-4816, epoxy equivalent 403g/eq, manufactured by Dainippon ink K.K., and having the following structural formula:

wherein R is an aliphatic chain segment, and m is 0.5-3;

a-4: the product model DX7160, the epoxy equivalent 430g/eq, manufactured by Jiansheng materials science and technology Limited in Hunan, has the following structure:

wherein R is an aliphatic chain segment, and m is 0.5-3;

a-5: common bisphenol A epoxy resin, product model NPES-901, epoxide equivalent 475g/eq, manufactured by south Asia electronic materials;

(B) phenoxy resin

B-1: a commercial model of EPONOL Resin53-BH-35, weight average molecular weight 55000, manufactured by Momenti ye corporation;

b-2: commercial model PKHH, weight average molecular weight 50000, manufactured by Inchem;

b-3: commercial model ERF-001, weight average molecular weight 40000, Nissin iron chemical manufacturing;

b-4: a commercial model YP-50SB with a weight-average molecular weight of 25000, manufactured by Dongdu chemical synthesis;

b-5: a commercial model YP-50 with a weight average molecular weight of 70000, manufactured by Dongdu chemical synthesis;

(C) biphenyl epoxy resin

C-1: a product model NC-3000H, an epoxy equivalent of 285g/eq, manufactured by Nippon chemical Co., Ltd;

c-2: commercial product model YX-4000, epoxy equivalent 185g/eq, manufactured by Mitsubishi chemical corporation;

(D) curing agent

D-1: triethylene tetramine;

d-2: diamino diphenyl sulfone;

d-3: active ester, trade mark HPC-8000-;

(E) heat conductive filler

E-1: alumina, sumitomo japan;

e-2: boron nitride, american mezzo;

(F) curing accelerator

F-1: 2-methylimidazole.