TWI688063B - Copper foil and components for heat dissipation - Google Patents

Abstract

The invention provides a copper foil for heat dissipation with excellent heat dissipation characteristics. A copper foil for heat dissipation, characterized by having: a copper foil base material; and a polymer film on at least any one main surface of the copper foil base material.

Description

Copper foil and components for heat dissipation

The invention relates to a copper foil for heat dissipation and a heat dissipation component.

In recent years, with the miniaturization and high precision of electronic equipment, malfunctions caused by heat generation of electronic components used have become a problem. Traditionally, there have been various researches to release the heat of such components in electronic equipment. Development (Patent Literature 1 etc.).

【Prior Technical Literature】 【Patent Literature】

[Patent Document 1] Japanese Patent Laid-Open No. 08-078461

The mounting substrate of an electronic device usually has a component that generates heat due to use, but if the heat of the component cannot be properly released, there is a risk of failure.

Here, in an embodiment of the present invention, an object is to provide a copper foil for heat dissipation and a heat dissipation member having excellent heat dissipation characteristics.

That is, one embodiment of the copper foil for heat dissipation of the present invention is characterized by having: a copper foil base material; and a polymer film on at least any one main surface of the copper foil base material.

An embodiment of the copper foil for heat dissipation of the present invention, wherein the thickness of the polymer film is 0.1 μm to 10 μm.

An embodiment of the copper foil for heat dissipation of the present invention, wherein the thickness of the polymer film is 0.5 μm to 8 μm.

An embodiment of the copper foil for heat dissipation of the present invention, wherein the thickness of the polymer film is 1 μm to 5 μm.

According to an embodiment of the copper foil for heat dissipation of the present invention, the polymer film includes a polymer having at least one kind of hetero atom in the repeating unit.

An embodiment of the copper foil for heat dissipation of the present invention, wherein the polymer includes at least one selected from the group consisting of carbonyl group, carboxyl group, ether group, epoxy group, hydroxyl group, and halogen in the repeating unit .

An embodiment of the copper foil for heat dissipation of the present invention, wherein the aforementioned polymer includes a resin selected from the group consisting of polyester resin, polycarbonate resin, polyvinyl alcohol resin, cellulose resin, epoxy resin, nylon resin, and polyether At least one kind of resin and fluororesin group.

According to one embodiment of the copper foil for heat dissipation of the present invention, the aforementioned polymer comprises selected from polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, Cellulose acetate, cellulose triacetate, cellophane, bisphenol A epoxy resin, polycaprolactam, polydodecylamide, polyethylene oxide, polypropylene oxide, polyvinylidene fluoride, and At least one of the polytetrafluoroethylene groups.

According to an embodiment of the copper foil for heat dissipation of the present invention, at least any one main surface of the copper foil base material has a plating treatment layer; and the plating treatment layer has the polymer film.

An embodiment of the copper foil for heat dissipation of the present invention, wherein the surface roughness Ra of the plating surface of the plating layer is 0.30 to 1.50.

An embodiment of the copper foil for heat dissipation of the present invention, wherein the surface roughness Rz of the plating treatment surface of the plating treatment layer is 2.50 to 9.50.

An embodiment of the copper foil for heat dissipation of the present invention, wherein the plating layer has a roughened particle layer.

According to an embodiment of the copper foil for heat dissipation of the present invention, the plating layer has a coating layer on the roughened particle layer.

An embodiment of the copper foil for heat dissipation of the present invention, wherein the coating layer contains at least one selected from the group consisting of Cu, Zn, Ni, Co, Cr, W, and Fe.

In one embodiment of the copper foil for heat dissipation of the present invention, the coating layer contains Co and Ni.

An embodiment of the copper foil for heat dissipation of the present invention, wherein the coating layer includes: a coating lower layer and a coating upper layer on the coating lower layer; the coating lower layer contains Cu, Co, and Ni; the coating The upper layer contains Co and Ni.

According to an embodiment of the copper foil for heat dissipation of the present invention, the thickness of the coating layer is 0.001 to 1.0 μm.

According to an embodiment of the copper foil for heat dissipation of the present invention, the thickness of the coating layer is 0.002 μm to 0.5 μm.

According to an embodiment of the copper foil for heat dissipation of the present invention, the thickness of the coating layer is 0.005 μm to 0.3 μm.

In addition, one embodiment of the heat dissipation member of the present invention is characterized by including the above-mentioned copper foil for heat dissipation.

The embodiment of the present invention can provide a copper foil for heat dissipation with excellent heat dissipation characteristics.

1‧‧‧Layered body

10‧‧‧Insulation

20‧‧‧heater

30‧‧‧ Adhesive

40‧‧‧SUS board

50‧‧‧ Grease for heat dissipation

60‧‧‧Copper foil for heat dissipation

70‧‧‧Body tape

100‧‧‧Infrared thermal imager

[Fig. 1] A cross-sectional schematic diagram showing the evaluation method of the thermographic representation temperature in Examples 1 to 11 and Comparative Examples 1 to 3.

In the following, the present invention is not limited to each embodiment type, and the constituent elements can be modified and embodied as long as they do not deviate from the gist thereof. In addition, various inventions can be formed by appropriately combining the plural constituent elements described in each embodiment. For example, some constituent elements of all constituent elements shown in the embodiment may be deleted. Furthermore, the components of different implementation types can be combined appropriately.

In recent years, mobile devices such as smartphones and tablet PCs have been actively developed. Further, high-integration and high-output substrates are mounted on miniaturized devices, and the problem of heat dissipation is increasingly attracting attention. Here, as a result of intensive research and review, the inventors found that by having a polymer film on at least any one main surface of the copper foil substrate, the heat dissipation characteristics of the copper foil can be improved.

Hereinafter, a copper foil for heat dissipation according to an embodiment of the present invention will be described.

A copper foil for heat dissipation according to an embodiment of the present invention includes a copper foil substrate and a polymer film on at least any one main surface of the copper foil substrate. According to the present embodiment, by having a polymer film, it can have excellent heat dissipation characteristics.

(Copper foil substrate)

The type of copper foil substrate that can be used in this embodiment is not particularly limited. In addition, the copper foil base material typically used in this embodiment may be either electrolytic copper foil or rolled copper foil. In general, electrolytic copper foil is manufactured by electrolysis of copper on a drum of titanium or stainless steel by a copper sulfate plating bath, and rolled copper foil is manufactured by repeatedly performing plastic processing and heat treatment with a calender roll. Rolled copper foil is often suitable for applications requiring flexibility. In addition, the term "copper foil base material" in this specification also includes a copper alloy foil base material when used alone. The thickness of the copper foil base material is preferably 1 μm or more that does not cause wrinkles or the like during manufacturing. However, considering the thinness of smart phones or tablet PCs. The size of the miniaturization is preferably less than 20μm.

(Polymer film)

In this embodiment, in order to improve the heat radiation, the polymer film is preferably a polymer containing at least one kind of hetero atoms in the repeating unit. The reason is that the heat radiation characteristic is closely related to the chemical structure of the resin in the coating film, and it can be deduced that the polymer with more infrared absorption peaks showing a broad spectrum of strong, the higher the emissivity.

The polymer, which shows most broad-spectrum strong infrared absorption peaks, preferably contains at least one selected from the group consisting of carbonyl group, carboxyl group, ether group, epoxy group, hydroxyl group, and halogen in the repeating unit. This polymer is not particularly limited as long as it has a chemical structure that exhibits a broad spectrum of strong infrared absorption peaks, and examples include polyester resin, polycarbonate resin, polyvinyl alcohol resin (PVA), and fiber Plain resin, epoxy resin, nylon resin, polyether resin, and fluorine resin.

The polyester resin is not particularly limited, and examples thereof include polyethylene terephthalate, polybutylene terephthalate, and polytrimethylene terephthalate.

The polycarbonate resin is not particularly limited, and examples thereof include those produced from 2,2-bis(4-hydroxybenzene)propane (bisphenol A).

Polyvinyl alcohol resin refers to the saponification of polyvinyl acetate.

The cellulose resin is not particularly limited, and examples thereof include cellulose acetate, cellulose triacetate, and cellophane.

The epoxy resin is not particularly limited, and examples thereof include bisphenol A epoxy resin.

The nylon resin is not particularly limited, and examples thereof include polycaprolactam (nylon 6) and polydodecylamide (nylon 12).

The polyether resin is not particularly limited, and examples thereof include polyethylene oxide and polypropylene oxide.

The fluororesin is not particularly limited, and examples thereof include polyvinylidene fluoride and polytetrafluoroethylene.

The thickness of the polymer film is preferably 0.1 μm or more, preferably 0.5 μm or more, more preferably 1 μm or more, and even more preferably 2 μm or more in order to improve heat radiation. However, considering the thinness of smart phones or tablet PCs. The specification for miniaturization is preferably 10 μm or less, preferably 8 μm or less, more preferably 5 μm or less, and even more preferably 3 μm or less. In addition, the thickness of the polymer film refers to the average thickness of the polymer film.

For the method of measuring the thickness of the polymer film, an example of the method of the measuring device will be described below.

First, the thickness of the copper foil base material is measured at 3 points or more with an instrument thickness gauge to calculate the average value of 3 or more points. Next, the copper foil for heat dissipation which has a polymer film on the said copper foil base material is prepared. In addition, the thickness of the copper foil for heat dissipation is measured at 3 points or more with an instrument thickness gauge to calculate the average value of 3 or more points. The average thickness of the copper foil substrate is subtracted from the average thickness of the copper foil for heat dissipation to calculate the thickness of the polymer film (average thickness).

In addition, the case where the copper foil for heat dissipation has a roughened particle layer and a polymer film or a roughened particle layer, a coating layer, and a polymer film on the main surface of the copper foil base material is as follows. First, the thickness of the copper foil on which the roughened particle layer is formed on the main surface of the copper foil base material, or the roughened particle layer and the coating layer is formed is measured by 3 or more points by an instrument thickness gauge, and the average of 3 or more points is calculated value. Next, a copper foil for heat dissipation having a roughened particle layer and a polymer film or a roughened particle layer, a coating layer, and a polymer film on the main surface of the copper foil base material is prepared. In addition, the thickness of the copper foil for heat dissipation is measured at 3 points or more with an instrument thickness gauge to calculate the average value of 3 or more points. The thickness of the polymer film (average thickness) is calculated from the average value of the thickness of the copper foil for heat dissipation, subtracting the average value of the thickness of the aforementioned copper foil.

In addition, in this embodiment, in order to improve the adhesion between the copper foil substrate and the polymer film, a rust prevention layer may be formed on the copper foil substrate, and chromate treatment may be further applied to the surface. Silane coupling treatment, etc. Known ones can be used for the antirust layer and the silane coupling treatment.

(Plating layer)

In this embodiment, the copper foil substrate is further provided with a plating layer on at least any one main surface, and it is preferable to have a polymer film on the plating layer.

In the present embodiment, the surface roughness Ra of the plating surface of the plating layer is preferably 0.30 or more, preferably 0.40 or more, and more preferably 0.45 or more in order to dissipate the heat generated by the heating element. However, in order to prevent coarse particles from falling off due to external force, it is preferably 1.50 or less, preferably 1.30 or less, and more preferably 1.20 or less. In addition, the surface roughness Ra represents the arithmetic average roughness described in JIS B 0601:2013.

In addition, in the present embodiment, the surface roughness Rz of the plating surface is preferably 2.50 or more, preferably 3.00 or more, and more preferably 3.72 or more in order to dissipate the heat generated by the heating element. However, in order to prevent coarse particles from falling off due to external force, it is preferably 9.50 or less, 8.00 or less, and 7.74 or less. The surface roughness Rz represents the maximum height roughness described in JIS B 0601:2013.

In this embodiment, when the plating surface of the plating layer is measured using a laser microscope, the surface area ratio B/A of the surface area B of the plating surface relative to the projected area A of the plating surface is not particularly limited. For example, in order to further improve the heat radiation of the plating layer, the surface area ratio B/A is preferably 1.42 or more, preferably 1.60 or more, more preferably 1.81 or more, even more preferably 2.18 or more, and even more preferably 2.35 or more. However, even if the surface area ratio B/A is higher, the heat radiation of the plating layer is more excellent, but the roughened particles are likely to fall off due to external force, so the surface area ratio B/A is preferably 3.42 or less, and 3.25 or less. Good, 3.10 or less is even better, 2.98 or less is even better, and 2.88 or less is even better.

(Coarse particle layer)

In this embodiment, the plating layer is preferably provided with a coarsened particle layer in order to improve the heat radiation. That is, in this embodiment, the roughened particle layer and the polymer film are sequentially formed on at least any one main surface of the copper foil substrate. In addition, in the roughened particle layer, the roughening treatment can be performed, for example, by forming roughened particles with copper or a copper alloy. The roughening treatment can also be fine.

In the case of the roughened particle layer and the polymer film on the roughened particle layer, the polymer film is coated on the surface of the roughened particle. According to this, by coating the surface of the roughened particles with the polymer film, the surface area of the polymer film is increased, thereby further improving the heat radiation.

In addition, there are cases where the roughened particles are broken at the front end, or the coarsened particles are peeled off from the foundation, which is generally called the dusting phenomenon. In this dusting phenomenon, although the roughened particle layer subjected to roughening plating has excellent heat radiation, the roughened particles are liable to fall off due to external force, and peeling may occur due to "friction" when making or using copper foil. Here, in this embodiment, in order to suppress dusting, the surface of the roughened particles is covered with a polymer film. By this, the front end portion of the roughened particles is thickened by the polymer film, and the basis of the roughened particles is thickened by the coating layer and the polymer film. In this way, by forming a polymer film on the roughened particle layer, the roughened particles are less likely to fall off due to external force, and dusting can be suppressed.

(Coating)

In this embodiment, the plating layer preferably has a roughened particle layer and a coating layer on the roughened particle layer. That is, in this embodiment, at least any one main surface of the copper foil substrate is formed in this order: a roughened particle layer, a coating layer, and a polymer film. This coating layer is coated on the surface of the branch of coarsened particles. Further, on this coating layer, a polymer film is formed. Therefore, in the present embodiment, since the coating layer has a polymer film, the synergistic effect of the coating layer and the polymer film further improves the heat radiation and also improves the dusting characteristics.

The roughened particle layer, after the roughened particles are formed of copper or a copper alloy, can be further provided to contain a material selected from the group consisting of Cu, Zn, Ni, Co, Cr, etc. from the viewpoint of heat radiation, dusting, and adhesion. Smooth plating of at least one coating layer in the group consisting of W and Fe. For example, on the roughened particle layer, there is a coating lower layer and a coating upper layer on the coating lower layer. The coating lower layer contains Cu, Co, and Ni, and the coating upper layer preferably contains Co and Ni. In addition, these metals are preferably contained in all or part of the coating layer (for example, the upper part).

The thickness of the coating layer is preferably 0.001 μm or more, preferably 0.002 μm or more, more preferably 0.005 μm or more, and even more preferably 0.01 μm or more in order to improve the heat radiation. However, considering the thinness of smart phones or tablet PCs. The specification for miniaturization is preferably 1.0 μm or less, preferably 0.5 μm or less, more preferably 0.3 μm or less, and even more preferably 0.1 μm or less. The thickness of the coating layer refers to the average thickness of the coating layer.

For the method of measuring the thickness of the coating layer, an example of the method of measuring the weight will be described below.

First, a copper foil for heat dissipation in which a roughened particle layer and a coating layer are formed is prepared. A sample of 2 cm×2 cm was taken from the copper foil for heat dissipation, and the sample was dissolved in a 20% by volume nitric acid aqueous solution to obtain a solution. Next, this solution was quantitatively analyzed by atomic absorption spectroscopy using an atomic absorption spectrophotometer to determine the concentration of each metal contained in the coating layer in the aforementioned sample, and the metal concentration in each metal in the coating layer in the aforementioned sample was measured using this metal concentration The weight is quantified. The volume of the coating layer is calculated from the weight of each metal obtained and the density of the metal. Then, the volume of the obtained coating layer is divided by the product of the area of the sample (4 cm ² ) and the measured surface area ratio to calculate the thickness of the coating layer (average thickness).

In addition, in this embodiment, in order to improve the adhesion between the plating layer and the polymer film, an anti-rust layer may be formed on the plating layer, and chromate treatment or silane coupling may be further applied to the surface Processing and other processing. Known ones can be used for the antirust layer and the silane coupling treatment.

Next, an example of each formation condition (plating bath composition and plating conditions, thin film conditions) of the roughened particle layer, the coating layer, the rust prevention layer, and the polymer film when forming the above-mentioned plating treatment layer is shown below.

(A) Coarse particle layer

The roughened particle layer is preferably formed on the main surface on either side of the copper foil substrate by (A-1) forming the roughened particle layer under the conditions of forming 1. Further, in addition to the aforementioned (A-1) formation of the roughened particle layer 1, it is preferable to form a roughened particle layer in which the roughened particles are further grown by the condition of (A-2) formation of the roughened particle layer 2.

(A-1) Formation of roughened particle layer 1 (Cu plating)

The process of forming the roughened particle layer 1 is equivalent to the process of roughening plating (coarse plating). The rough plating is a plating performed by setting the current density above the limit current density.

Liquid composition: copper 10~20g/L; sulfuric acid 50~100g/L

Liquid temperature: 25~50℃

Current density: 20~58A/dm ²

Time: 0.5~5 seconds

(A-2) Formation of roughened particle layer 2 (Cu plating)

The process of forming the roughened particle layer 2 is equivalent to the process of roughening plating (coarse plating). The roughening plating is a plating performed by setting the current density to the limit current density.

Liquid composition: copper 15~50g/L; sulfuric acid 60~100g/L

Liquid temperature: 25~50℃

Current density: 20~58A/dm ²

Time: 1~10 seconds

In addition, the lower the current density, and/or the larger the Coulomb amount, the greater the effect of reducing the aforementioned surface roughness Ra may be.

In addition, the roughened particle layer may be formed by performing the treatment once or twice or more.

(B) Formation of coating

After the coating layer is formed on the roughened particle layer by (B-1) forming the coating lower layer, the coating upper layer is preferably formed by (B-2) forming the coating upper layer. The process of forming the lower coating layer and the upper coating layer is equivalent to the smooth plating process. Smooth plating is the plating that sets the current density at the limit current density. The coating lower layer can be formed under the following conditions. In addition, the coating lower layer may not be formed.

(B-1) Conditions for forming the underlayer

An example of the formation conditions of the coating underlayer is as follows.

Liquid composition: Cu10~20g/L; at least one element selected from the group consisting of Zn, Ni, Co, Cr, W, and Fe is individually 0.001~15g/L

pH: 2~3

Liquid temperature: 30~50℃

Current density: 10~50A/dm ²

Time: 0.1~2 seconds

(B-2) Formation conditions of the coated upper layer

An example of the formation conditions of the coating upper layer is as follows.

Liquid composition: Cu10~20g/L; at least one element selected from the group consisting of Zn, Ni, Co, Cr, W, and Fe is individually 0.001~15g/L

pH: 2~3

Liquid temperature: 30~50℃

Current density: 0.5~20A/dm ²

Time: 0.1~300 seconds

In addition, the coating lower layer and the coating upper layer may be formed by one or more treatments.

(C) Anti-rust layer

In addition, a rust prevention layer may be formed on the copper foil base material, the roughened particle layer, or the coating layer, especially a chromate layer. The preferred anti-rust treatment in this embodiment is the coating treatment of chromium oxide alone or the coating treatment of a mixture of chromium oxide and zinc/zinc oxide. The coating treatment of the mixture of chromium oxide and zinc/zinc oxide is to use a plating bath containing zinc salt or zinc oxide and chromate for electroplating to cover the zinc-chromium-based mixture formed by zinc or zinc oxide and chromium oxide. Treatment of rust layer.

The plating bath, typically, uses at least one of dichromates such as K ₂ Cr ₂ O ₇ and Na ₂ Cr ₂ O ₇ or CrO3; and water-soluble zinc salts such as ZnO and ZnSO ₄ . At least one such as 7H ₂ O; and mixed aqueous solution of alkali metal hydroxide. Representative plating bath compositions and electrolysis conditions are as follows, for example. In the following, although it indicates the conditions of electrolytic chromate treatment, it may be immersion chromate treatment.

Plating conditions for forming anti-rust layer

Liquid composition: potassium dichromate 1~10g/L; zinc 0~5g/L

pH: 3~4

Liquid temperature: 50~60℃

Current density: 0~2A/dm ² (for electrolytic chromate treatment)

Time: 1~10 seconds

(D) Formation of polymer film

The polymer film is formed on the main surface on either side of the copper foil substrate. Further, it is preferable to form a polymer film on the plating treatment layer, or to form a polymer film on the rust prevention layer.

The coating method is spraying with a spray of a coating solution containing a polymer; any of coating, dipping, and fluidized bed of a coating machine can be used. The thickness of the polymer film is adjusted to 0.1 to 10 μm by adjusting the solid concentration or coating amount. After that, if necessary, annealing treatment may be applied for the purpose of improving the ductility of the copper foil.

The heat dissipation member provided with the copper foil for heat dissipation of the present embodiment can be used, for example, to dissipate heat generated by the heat generating parts built in mobile devices such as smartphones and tablet PCs.

【Example】

Hereinafter, description will be made based on Examples and Comparative Examples. In addition, this embodiment is only representative of one example, and is not limited to this example. That is, it includes other aspects or modifications included in the present invention.

<Example 1>

A polymer film was formed on the main surface of either side of a rolled copper foil (JX Metal Co., Ltd., TPC foil) with a thickness of 12 μm within the range of conditions shown below. The coating conditions are as follows.

(A) Formation of polymer film (PVA)

Solvent: PVA6 mass% aqueous solution

Coating method: metal applicator

Film thickness: 1.5μm

First, for the rolled copper foil, the surface roughness Ra and Rz, and the surface area ratio were evaluated. In addition, with regard to the obtained copper foil for heat dissipation, the thickness of the polymer film, thermal imaging indicates temperature and dusting. The results are shown in Table 1. In addition, the evaluation methods of the surface roughness Ra and Rz, the surface area ratio, the thickness of the polymer film, the temperature indicated by the thermal imaging, and the dusting are individually described.

(Surface roughness Ra, Rz)

The surface roughness Ra (arithmetic mean roughness) of the surface of the roughened particle layer side surface of the samples of each example and comparative example was measured using a non-contact roughness measuring machine (laser microscope, LEXT OLS 4000 manufactured by Olympus) Surface roughness Rz (maximum height roughness). The laser wavelength of the same measuring machine is 405nm, and the magnification of the built-in lens is 20 times. Ra and Rz are measured at arbitrary 5 points, and the average value of these 5 points of Ra and Rz is regarded as the value of Ra and Rz. In addition, Ra and Rz were also measured on the surface of the copper foil base material before roughening used in each of the Examples and Comparative Examples that was intended to be roughened. In addition, the measurement of Ra and Rz is performed in the TD direction (the width direction, that is, the direction perpendicular to the rolling direction of the copper foil base material). The setting of the main items in the measurement conditions and analysis conditions is as follows.

<Measurement conditions>

Object lens: MPLAPONLEXT 100 (magnification: 100 times; opening number: 0.95)

Scanning mode: XYZ high precision (high resolution: 10nm, pixel number of captured data: 1024×1024)

Measuring range: horizontal 130μm × vertical 130μm

Measuring ambient temperature: 23~25℃

<Analysis conditions>

Analysis area setting: none (the measurement range is full-field analysis)

Boundary: none (none of λc, λs , λf )

Noise elimination and tilt correction: None

(Surface area ratio)

The surface area of the plated surface was measured using a non-contact type roughness measuring machine (laser microscope, LEXT OLS 4000 manufactured by Olympus). As the surface area ratio B/A, the surface area B of the plated surface relative to the projected area A of the plated surface was used. In addition, for those having a polymer film on the plating layer, the surface area of the plating layer was measured before applying the polymer film. The setting of the main items in the measurement conditions and analysis conditions is as follows.

<Measurement conditions>

The conditions for measuring the surface roughness Ra and Rz are the same as above.

In addition, since the measurement range is 130 μm in width×130 μm in length, the projected area A of the plated surface is: 16923 μm ² .

Measuring ambient temperature: 23~25℃

<Analysis conditions>

The conditions are the same as the analytical surface roughness Ra and Rz mentioned above.

However, regarding the threshold setting, it is a histogram; the threshold 1: 0%; the threshold 2: 100%.

(Thickness of polymer film)

The thickness of the copper foil for heat dissipation obtained in Example 1 was measured by an instrument thickness gauge (Ono Tester Co., Ltd., digital counter DG-1270), and the thickness of the rolled copper foil (12 μm) was deducted from the average value of 3 points To calculate the thickness of the polymer film.

(Thermal image indicates temperature)

Using an infrared thermal imager (Chino Co., Ltd. CPA-0150J), the measurement was performed according to the following measurement conditions. As shown in FIG. 1, the following are made in order from the following: heat insulation material 10, heater 20, adhesive (ARON ALPHA (registered trademark) 30), SUS plate 40, heat dissipating grease 50, The laminated body 1 made of the copper foil 60 for heat dissipation is arranged in a cladding made of a heat insulating member (not shown). Further, on the copper foil 60 for heat dissipation of the laminated body, a black body tape 70 having an emissivity of 0.9 is arranged so as to cover a half of the area of the copper foil 60 for heat dissipation. A direct current (current: 0.3A; voltage 4.0V) is applied to heat the heater 20 to the area covered by the black body tape 70 of the laminate 1 on the infrared thermal imager 100, indicating that the temperature shows a temperature of 88.0°C. Using the infrared thermal imager 100, the indicated temperature of the portion of the copper foil 60 for heat dissipation of the laminate 1 was measured based on the area covered by the black body tape 70 (88.0°C). In general, the infrared thermal imager 100 detects the infrared energy emitted from the surface of the sample and uses it as the temperature. When measuring the sample with the outermost surface with a low emissivity, the infrared energy released from the sample is extremely small, and the actual sample temperature will deviate from the temperature indicated by the thermal imaging. Here, the thermal imaging performance of the copper foil for heat dissipation obtained in Example 1 is compared with the thermal imaging temperature of the black body tape with known emissivity as a reference, and the thermal radiation of the copper foil for heat dissipation is evaluated. In addition, in Table 1, thermography indicates that the temperature is closer to the reference 88.0°C, which indicates that the emissivity is higher. That is, it indicates that the ability to emit infrared rays is excellent, and the heat radiation characteristics are good.

(Dust assessment)

The dusting evaluation was performed by attaching a transparent invisible tape (MonotaRO Co., Ltd., model number 125076) on the treated surface of the copper foil for heat dissipation obtained in Example 1 by the tape transfer method.

<Evaluation criteria>

◎: The tape is completely free of rough particle transfer.

○: The transfer of slightly coarsened particles is partially present.

×: A case where coarse particle transfer is observed on the entire surface (a case where the entire surface is observed even slightly) is observed.

<Example 2>

On the main surface of either side of the rolled copper foil (JX Metal Co., Ltd., TPC foil) with a thickness of 12 μm, except for (A) the formation of the polymer film, the solvent used was prepared as a PVA 8% by mass aqueous solution, and the polymer film The thickness was changed to 2.5 μm, and the others were the same as in Example 1, and a polymer film was formed.

For the obtained copper foil for heat dissipation, the thickness of the polymer film, thermal imaging temperature and dusting were evaluated. The results are shown in Table 1. The surface roughness Ra and Rz of the plated surface and the surface area ratio are the values of the copper foil for heat dissipation of Example 1.

<Example 3>

On the main surface of either side of the rolled copper foil (JX Metal Co., Ltd., TPC foil) with a thickness of 12 μm, except for (A) the formation of the polymer film, the solvent used was prepared as a PVA 8% by mass aqueous solution, and the polymer film The thickness was changed to 3.5 μm, and the others were the same as in Example 1, and a polymer film was formed.

For the obtained copper foil for heat dissipation, the thickness of the polymer film, thermal imaging temperature and dusting were evaluated. The results are shown in Table 1. The surface roughness Ra and Rz of the plated surface and the surface area ratio are the values of the copper foil for heat dissipation of Example 1.

<Example 4>

On the main surface of either side of a rolled copper foil (JX Metal Co., Ltd., TPC foil) with a thickness of 12 μm, except for (A) the formation of the polymer film, the solvent used was prepared as a PVA 10% by mass aqueous solution, and the polymer film The thickness was changed to 5.0 μm, and the others were the same as in Example 1 to form a polymer film.

For the obtained copper foil for heat dissipation, the thickness of the polymer film, thermal imaging temperature and dusting were evaluated. The results are shown in Table 1. The surface roughness Ra and Rz of the plated surface and the surface area ratio are the values of the copper foil for heat dissipation of Example 1.

<Example 5>

A roughened particle layer (Cu) and a coating layer (Cu-Ni) are sequentially formed on the main surface of either side of a rolled copper foil (JX Metal Co., Ltd., TPC foil) of 12 μm thickness within the range of conditions shown below -Co; Ni-Co), and polymer film (PVA). The composition of the plating bath used, the plating conditions, and the formation conditions of the polymer film are as follows. Furthermore, the thickness of the copper foil (roughened particle layer and coating layer) obtained before the formation of the polymer film and the thickness of the copper foil for heat dissipation obtained in Example 5 were measured by a meter thickness gauge at three points, and their values were calculated respectively. The average of the points. Next, the thickness of the polymer film (average thickness) is calculated by subtracting the average of the thickness of the copper foil from the average of the thickness of the copper foil for heat dissipation.

[Composition of plating bath and plating conditions]

(A) Formation of roughened particle layer 1 (Cu plating)

Liquid composition: copper 11g/L; sulfuric acid 50g/L

Current density: 40A/dm ²

Liquid temperature: normal temperature

Time: 1 second

Times: 2 times

(B) Formation of roughened particle layer 2 (Cu plating)

Liquid composition: copper 20g/L; sulfuric acid 100g/L

Current density: 19A/dm ²

Liquid temperature: 50℃

Time: 4.5 seconds

Times: 1 time

(C) Formation of coating underlayer (Cu-Ni-Co plating)

Liquid composition: copper 15.5g/L; nickel 9.5g/L; cobalt 7.5g/L

Current density: 15A/dm ²

pH: 2.5

Liquid temperature: 36℃

Time: 0.79 seconds

Times: 2 times

(D) Formation of overlying coating (Ni-Co plating)

Liquid composition: nickel 13g/L; cobalt 3g/L

Current density: 11.9A/dm ²

pH: 2.5

Liquid temperature: 40℃

Time: 1 second

Times: 2 times

(E) Formation of polymer film (PVA)

Solvent: PVA6 mass% aqueous solution

Coating method: metal applicator

Film thickness: 1.0μm

First, before forming the polymer film, the surface area ratio of the coating layer was evaluated. For the obtained copper foil for heat dissipation, the thickness of the polymer film, thermal imaging temperature and dusting were evaluated. The results are shown in Table 1.

<Example 6>

On the main surface of either side of a rolled copper foil (JX Metal Co., Ltd., HA-V2 foil) with a thickness of 12 μm, except that (E) the solvent used for the formation of the polymer film is prepared as a PVA 10% by mass aqueous solution, and the polymer The thickness of the film was changed to 5.0 μm, and the others were the same as in Example 5. A roughened particle layer (Cu), a coating layer (Cu-Ni-Co; Ni-Co), and a polymer film (PVA) were formed in this order.

First, for the obtained copper foil for heat dissipation, the thickness of the polymer film, thermal imaging temperature and dusting were evaluated. The results are shown in Table 1. The surface area ratio of the plated surface is the value of the copper foil for heat dissipation of Example 5.

<Example 7>

A roughened particle layer (Cu) and a coating layer (Cu) are sequentially formed on the main surface of either side of a rolled copper foil (JX Metal Co., Ltd., HA-V2 foil) of 12 μm thickness within the range of conditions shown below -Ni-Co; Ni-Co), anti-rust layer, and polymer film (PVA). The composition of the plating bath used, the plating conditions, and the formation conditions of the polymer film are as follows. Furthermore, the thickness of the copper foil (roughened particle layer, coating layer, and rust prevention layer) obtained before the formation of the polymer film and the thickness of the copper foil for heat dissipation obtained in Example 7 were each measured by a meter thickness gauge at three points, And calculate the average of its 3 points respectively. Next, the thickness of the polymer film (average thickness) is calculated by subtracting the average of the thickness of the copper foil from the average of the thickness of the copper foil for heat dissipation.

[Composition of plating bath and plating conditions]

(A) Formation of roughened particle layer 1 (Cu plating)

Liquid composition: copper 11g/L; sulfuric acid 50g/L

Current density: 45A/dm ²

Liquid temperature: normal temperature

Time: 0.68 seconds

Times: 2 times

(B) Formation of roughened particle layer 2 (Cu plating)

Liquid composition: copper 20g/L; sulfuric acid 100g/L

Current density: 4.11A/dm ²

Liquid temperature: 50℃

Time: 1.44 seconds

Times: 2 times

(C) Formation of coating underlayer (Cu-Ni-Co plating)

Liquid composition: copper 15.5g/L; nickel 9.5g/L; cobalt 7.5g/L

Current density: 30.3A/dm ²

pH: 2.5

Liquid temperature: 36℃

Time: 0.5 seconds

Times: 2 times

(D) Formation of coated upper layer 1 (Ni-Co plating)

Liquid composition: nickel 13g/L; cobalt 3g/L

Current density: 13.7A/dm ²

pH: 2.5

Liquid temperature: 40℃

Time: 0.34 seconds

Times: 1 time

(E) Formation of coated upper layer 2 (Ni-Co plating)

Liquid composition: nickel 13g/L; cobalt 3g/L

Current density: 14.9A/dm ²

pH: 2.5

Liquid temperature: 40℃

Time: 0.34 seconds

Times: 1 time

(F) Formation of anti-rust layer

Liquid composition: potassium dichromate 1~10g/L; zinc 0~5g/L

pH: 3~4

Liquid temperature: 50~60℃

Current density: 0~2A/dm ² (for electrolytic chromate treatment)

Coulomb volume: 0~2As/dm ² (for electrolytic chromate treatment)

(G) Formation of polymer film (PVA)

Solvent: PVA4 mass% aqueous solution

Coating method: metal applicator

Film thickness: 1.0μm

First, before forming the anti-rust layer, the surface roughness Ra and Rz of the coating layer and the surface area ratio were evaluated. In addition, the obtained copper foil for heat dissipation was evaluated for the thickness of the polymer film, thermal imaging temperature and dusting. The results are shown in Table 1.

<Example 8>

On the main surface on either side of a rolled copper foil (JX Metal Co., Ltd., HA-V2 foil) with a thickness of 12 μm, except for (G), the solvent used for the formation of the polymer film is prepared as a PVA 6% by mass aqueous solution and polymerized The thickness of the film was changed to 1.5 μm, and the others were the same as in Example 7. A coarse particle layer (Cu), a coating layer (Cu-Ni-Co; Ni-Co), a rust prevention layer, and a polymer were formed in this order. Membrane (PVA).

For the obtained copper foil for heat dissipation, the thickness of the polymer film, thermal imaging temperature and dusting were evaluated. The results are shown in Table 1. In addition, the surface roughness Ra and Rz and the surface area ratio of the plated surface are the values of the copper foil for heat radiation of Example 7.

<Example 9>

On the main surface on either side of a rolled copper foil (JX Metal Co., Ltd., HA-V2 foil) with a thickness of 12 μm, except for (G), the solvent used for the formation of the polymer film is prepared as a PVA 8% by mass aqueous solution and polymerized The thickness of the film was changed to 2.0 μm, and the others were the same as in Example 7. A coarse particle layer (Cu), a coating layer (Cu-Ni-Co; Ni-Co), a rust prevention layer, and a polymer were formed in this order. Membrane (PVA).

For the obtained copper foil for heat dissipation, the thickness of the polymer film, thermal imaging temperature and dusting were evaluated. The results are shown in Table 1. The surface roughness Ra and Rz of the plated surface and the surface area ratio are the values of the copper foil for heat dissipation of Example 7.

<Example 10>

On the main surface on either side of a rolled copper foil (JX Metal Co., Ltd., HA-V2 foil) with a thickness of 12 μm, except for (G), the solvent used for the formation of the polymer film is prepared as a PVA 8% by mass aqueous solution and polymerized The thickness of the film was changed to 2.5 μm, and the others were the same as in Example 7. A coarse particle layer (Cu), a coating layer (Cu-Ni-Co; Ni-Co), a rust prevention layer, and a polymer were formed in this order. Membrane (PVA).

For the obtained copper foil for heat dissipation, the thickness of the polymer film, thermal imaging temperature and dusting were evaluated. The results are shown in Table 1. In addition, the surface roughness Ra and Rz and the surface area ratio of the plated surface are the values of the copper foil for heat radiation of Example 7.

<Example 11>

On the main surface on either side of a rolled copper foil (JX Metal Co., Ltd., HA-V2 foil) with a thickness of 12 μm, the solvent used for the formation of (G) polymer film was prepared as a PVA 10% by mass aqueous solution and polymerized The thickness of the film was changed to 3.0 μm, and the others were the same as in Example 7. A coarse particle layer (Cu), a coating layer (Cu-Ni-Co; Ni-Co), a rust prevention layer, and a polymer were formed in this order. Membrane (PVA).

For the obtained copper foil for heat dissipation, the thickness of the polymer film, thermal imaging temperature and dusting were evaluated. The results are shown in Table 1. In addition, the surface roughness Ra and Rz and the surface area ratio of the plated surface are the values of the copper foil for heat radiation of Example 7.

<Comparative Example 1>

The rolled copper foil (JX Metal Co., Ltd., TPC foil) used in Example 1 was evaluated for surface roughness Ra and Rz, surface area ratio, thermal imaging temperature, and dusting. The results are shown in Table 1.

<Comparative Example 2>

A roughened particle layer (Cu) and a coating layer (Cu-Ni) are sequentially formed on the main surface of either side of a rolled copper foil (JX Metal Co., Ltd., TPC foil) of 12 μm thickness within the range of conditions shown below -Co; Ni-Co). The composition and plating conditions of the plating bath used are as follows.

[Composition of plating bath and plating conditions]

(A) Formation of roughened particle layer 1 (Cu plating)

Liquid composition: copper 11g/L; sulfuric acid 50g/L

Current density: 40A/dm ²

Liquid temperature: normal temperature

Time: 1 second

Times: 2 times

(B) Formation of roughened particle layer 2 (Cu plating)

Liquid composition: copper 20g/L; sulfuric acid 100g/L

Current density: 19A/dm ²

Liquid temperature: 50℃

Time: 4.5 seconds

Times: 1 time

(C) Formation of coating underlayer (Cu-Ni-Co plating)

Liquid composition: copper 15.5g/L; nickel 9.5g/L; cobalt 7.5g/L

Current density: 15A/dm ²

pH: 2.5

Liquid temperature: 36℃

Time: 0.79 seconds

Times: 2 times

(D) Formation of overlying coating (Ni-Co plating)

Liquid composition: nickel 13g/L; cobalt 3g/L

Current density: 11.9A/dm ²

pH: 2.5

Liquid temperature: 40℃

Time: 1 second

Times: 2 times

For the obtained copper foil for heat dissipation, the surface area ratio, thermal imaging temperature and dusting were evaluated. The results are shown in Table 1.

<Comparative Example 3>

A roughened particle layer (Cu) and a coating layer (Cu) are sequentially formed on the main surface of either side of a rolled copper foil (JX Metal Co., Ltd., HA-V2 foil) of 12 μm thickness within the range of conditions shown below -Ni-Co; Ni-Co), and anti-rust layer. The composition and plating conditions of the plating bath used are as follows.

[Composition of plating bath and plating conditions]

(A) Formation of roughened particle layer 1 (Cu plating)

Liquid composition: copper 11g/L; sulfuric acid 50g/L

Current density: 45A/dm ²

Liquid temperature: normal temperature

Time: 0.68 seconds

Times: 2 times

(B) Formation of roughened particle layer 2 (Cu plating)

Liquid composition: copper 20g/L; sulfuric acid 100g/L

Current density: 4.11A/dm ²

Liquid temperature: 50℃

Time: 1.44 seconds

Times: 2 times

(C) Formation of coating underlayer (Cu-Ni-Co plating)

Liquid composition: copper 15.5g/L; nickel 9.5g/L; cobalt 7.5g/L

Current density: 30.3A/dm ²

pH: 2.5

Liquid temperature: 36℃

Time: 0.5 seconds

Times: 2 times

(D) Formation of coated upper layer 1 (Ni-Co plating)

Liquid composition: nickel 13g/L; cobalt 3g/L

Current density: 13.7A/dm ²

pH: 2.5

Liquid temperature: 40℃

Time: 0.34 seconds

Times: 1 time

(E) Formation of coated upper layer 2 (Ni-Co plating)

Liquid composition: nickel 13g/L; cobalt 3g/L

Current density: 14.9A/dm ²

pH: 2.5

Liquid temperature: 40℃

Time: 0.34 seconds

Times: 1 time

(F) Formation of anti-rust layer

Liquid composition: potassium dichromate 1~10g/L; zinc 0~5g/L

pH: 3~4

Liquid temperature: 50~60℃

Current density: 0~2A/dm ² (for electrolytic chromate treatment)

Coulomb volume: 0~2As/dm ² (for electrolytic chromate treatment)

The obtained copper foil for heat dissipation was evaluated by thermal imaging to indicate the temperature and dusting. The results are shown in Table 1. The surface roughness Ra and Rz of the plated surface and the surface area ratio are the values of the copper foil for heat dissipation of Example 7.

In Examples 1 to 11, it can be confirmed that the heat generated by the heating element can be dissipated well due to the polymer film. In addition, in Examples 2 to 4, 6, and 9 to 11, it can be confirmed that the thickness of the polymer film is 2.0 μm or more, so that the heat generated by the heating element can be further dissipated. Further, in Examples 5 to 11, it can be confirmed that since the polymer film is formed on the coating layer formed by Ni-Co, the heat generated by the heating element can be further dissipated well, and the evaluation of dusting is also good.

【Industrial Utilization】

The heat dissipation member using the copper foil for heat dissipation according to an embodiment of the present invention has excellent heat dissipation characteristics. In this way, the present invention provides a useful technology that, while advancing the development of electronic equipment, meets the requirements of miniaturization or high performance, and does not cause malfunctions and defects due to the heat generated by the electronic components used.

Claims (18)

A copper foil for heat dissipation, comprising: a copper foil substrate; and a plating treatment layer on at least any one main surface of the copper foil substrate; a polymer film on the plating treatment layer; and the plating treatment layer The surface roughness Ra of the plated surface is 0.30~1.50. The copper foil for heat dissipation as described in item 1 of the patent application range, wherein the thickness of the polymer film is 0.1 μm to 10 μm. The copper foil for heat dissipation as described in item 1 of the patent application range, wherein the thickness of the polymer film is 0.5 μm to 8 μm. The copper foil for heat dissipation as described in item 1 of the patent application range, wherein the thickness of the polymer film is 1 μm to 5 μm. The copper foil for heat dissipation as described in any one of items 1 to 4 of the patent application range, wherein the polymer film includes a polymer having at least one kind of hetero atom in the repeating unit. The copper foil for heat dissipation as described in item 5 of the patent application range, wherein the polymer contains at least one selected from the group consisting of carbonyl group, carboxyl group, ether group, epoxy group, hydroxyl group and halogen in the repeating unit 1 kind. The copper foil for heat dissipation as described in item 5 of the patent application scope, wherein the polymer includes a resin selected from polyester resin, polycarbonate resin, polyvinyl alcohol resin, cellulose resin, At least one member selected from the group consisting of epoxy resin, nylon resin, polyether resin, and fluorine resin. The copper foil for heat dissipation as described in item 5 of the patent application range, wherein the polymer includes a group selected from polyethylene terephthalate, polybutylene terephthalate, and polypropylene terephthalate Ester, cellulose acetate, cellulose triacetate, cellophane, bisphenol A epoxy resin, polycaprolactam, polydodecylamide, polyethylene oxide, polypropylene oxide, polyvinylidene fluoride , And at least one of the polytetrafluoroethylene group. The copper foil for heat dissipation as described in item 1 of the patent application scope, wherein the surface roughness Rz of the plating surface of the plating layer is 2.50 to 9.50. The copper foil for heat dissipation as described in item 1 of the patent application range, wherein the plating layer has a roughened particle layer. The copper foil for heat dissipation as described in item 10 of the patent application range, wherein the plating layer has a coating layer on the roughened particle layer. The copper foil for heat dissipation as described in item 11 of the patent application range, wherein the coating layer contains at least one selected from the group consisting of Cu, Zn, Ni, Co, Cr, W, and Fe. The copper foil for heat dissipation as described in item 11 of the patent application range, wherein the coating layer contains Co and Ni. The copper foil for heat dissipation as described in item 11 of the patent application scope, wherein the coating layer has: a coating lower layer and a coating upper layer on the coating lower layer; the coating lower layer contains Cu, Co, and Ni; The aforementioned coating upper layer contains Co and Ni. The copper foil for heat dissipation as described in item 11 of the patent application range, wherein the thickness of the coating layer is 0.001 μm to 1.0 μm. The copper foil for heat dissipation as described in item 11 of the patent application range, wherein the thickness of the coating layer is 0.002 μm to 0.5 μm. The copper foil for heat dissipation as described in item 11 of the patent application range, wherein the thickness of the coating layer is 0.005 μm to 0.3 μm. A heat dissipation component characterized by having the copper foil for heat dissipation described in any one of the items 1 to 17 of the patent application range.

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