TWI616123B - Method for manufacturing heat dissipation laminated material for mounted substrate - Google Patents

Abstract

The present invention provides an exothermic laminate for mounting substrates that can respond to the weight reduction, miniaturization, and thickness reduction of electronic equipment and can mount heat generated by the electronic component more efficiently even if an electronic component with a large amount of heat is installed. method. A copper layer (20) is fixed on a surface of one side of the resin film (10), and a circuit pattern layer (21) is formed by selective etching of the copper layer (20). After the circuit pattern layer (21) is formed An aluminum foil (30) is fixed on a surface opposite to a surface on one side of the resin film (10).

Description

Manufacturing method of exothermic laminated material for mounting substrate

The present invention relates to a method for manufacturing a general exothermic laminate for mounting substrates, and in particular, it relates to a method for producing an exothermic laminate for mounting substrates for mounting electronic components with large heat generation, for example, for mounting light emitting diodes A method for producing an exothermic laminate for mounting substrates of light emitting elements such as (LED).

Mounting substrates having circuits formed on one or both sides of the insulating layer are used in a wide range of fields. The circuit is formed of a copper or aluminum foil or a paste composition. Electronic components are mounted on the formed circuit. The electronic components to be installed include, for example: resistance elements, capacitors, transistors, various power elements; high-density integrated circuits such as MPU, CPU; light-emitting elements such as light-emitting diodes (LEDs) and laser diodes; Array elements.

In recent years, the performance required for electronic devices has been increasing, and among the above-mentioned electronic components, power consumption of power components and high-density integrated circuits also tends to increase. Furthermore, high-brightness objects have been developed for light-emitting devices. However, with the increase in power consumption of power elements and high-density integrated circuits, or the increase in heat generation caused by the increase in brightness of light-emitting elements, the heat-generating electronic components themselves and other electronic components will be adversely affected. For example, heat-generating electronic components or other electronic components may malfunction due to heat, decrease performance due to heat, or shorten life due to heat. Therefore, a structure has been proposed for removing and dissipating the heat generated by the electronic component with high efficiency.

On the other hand, in recent years, mobile electronic devices such as mobile phones, digital cameras, music players, voice recorders, and game consoles require thinness and thinness in addition to weight reduction and miniaturization. If a mounting substrate for mounting an electronic component can be directly laminated on a support or a frame of a portable electronic device, it will be effective in reducing the thickness. That is, the mounting substrate is required to be flexible.

Furthermore, thin TVs such as LCD TVs have tended to become larger in recent years. However, while expecting a larger screen for a thin TV, it is also desirable to reduce the weight and thickness of the TV body as much as possible. In order to reduce thickness and reduce power consumption, LEDs have been used as light sources for liquid crystal backlight devices. The LED is directly mounted on an insulating substrate. In order to cope with such a technical tendency, it is necessary to dissipate heat generated from the LED to a surface opposite to the surface on which the LED is mounted via the laminate for mounting substrates. In particular, an edge-lit liquid crystal backlight device has a structure in which a large number of LEDs are mounted per unit area, and therefore requires higher heat dissipation than a laminated material for mounting a substrate.

Here, for example, Japanese Patent Application Laid-Open No. 2010-98246 (Patent Document 1) discloses that it can release heat generated by electronic components such as LEDs with high efficiency, is thin and lightweight, and can use plastic addition to work. The three-dimensionally structured metal substrate is a copper-based layer formed on one surface of a stainless steel foil, and is then bonded to a copper foil for circuit formation through an insulating layer.

However, the method of forming a circuit on the mounting surface of a metal substrate as described above, Generally, as described in Patent Document 1, a method of selectively etching a copper foil is used. In this case, a copper foil is bonded to a metal foil (a stainless steel foil in Patent Document 1), and then the copper foil is subjected to selective etching.

However, when the strength and thickness of the metal foil on the opposite side from the mounting surface side are low, the unevenness of the circuit formed on the mounting surface is pushed into the metal foil side on the opposite side from the mounting surface side, and the Printed on the surface of metal foil, causing unevenness and smoothness. In addition, if the surface of the metal foil on which the unevenness has been formed is adhered to a support or a frame of a portable electronic device and used, there is a problem that voids occur and the thermal conductivity decreases.

The reason is that the object of the present invention is to provide a mounting substrate that can more efficiently dissipate the heat generated by the electronic component even if an electronic component with a large amount of heat is mounted in response to the reduction in weight, size, and thickness of the electronic device. Manufacturing method of exothermic laminated material.

The method for manufacturing an exothermic laminate for mounting substrates of the present invention includes the following steps: (A) a step of fixing a conductive layer to a surface on one side of an insulating film; (B) selecting the conductive layer (C) a step of forming a circuit pattern layer by means of an etching process; and (C) a step of fixing an aluminum foil to a surface on the side opposite to a surface on one side of the insulating film after the circuit pattern layer is formed.

In the manufacturing method of the exothermic laminated material for mounting substrate of the present invention, the aluminum foil contains Available: 0.5% by mass to 3.0% by mass of manganese, 0.0001% by mass to 0.2% by mass of chromium, 0.2% by mass to 1.8% by mass of magnesium, 0.0001% by mass to 0.6% by mass of titanium, and more than 0 by copper Mass% to 0.005 mass%, silicon exceeds 0 mass% to 0.1 mass%, iron exceeds 0 mass% to 0.2 mass%, and the rest is composed of aluminum and unavoidable impurities.

Furthermore, in the method for manufacturing an exothermic laminate for mounting substrates of the present invention, the insulating film preferably contains polyimide, polyethylene naphthalate, polyethylene terephthalate, and polytetrafluoro One of the groups selected by ethylene.

Since the exothermic laminate for mounting substrates manufactured in accordance with the present invention is provided with aluminum foil which is excellent in lightness, heat release (thermal conductivity), and bendability, it can respond to the weight reduction, miniaturization, and thickness reduction of electronic equipment. . Furthermore, according to the present invention, after the circuit pattern layer is formed, an aluminum foil having a predetermined strength and hardness is fixed to a surface on the side opposite to the surface on one side of the insulating film, so that the aluminum foil surface does not have unevenness. Thereby, even if the exothermic laminated material for a mounting substrate manufactured according to the present invention is adhered to a support or a frame of a portable electronic device and used, there is no possibility that voids occur and the thermal conductivity is reduced. Therefore, even if an electronic component having a large amount of heat is mounted, a heat-generating laminate for a mounting substrate capable of efficiently dissipating heat generated by the electronic component can be manufactured.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

First, as shown in FIG. 1, an adhesive layer (not shown) is interposed on a surface on one side of a resin film 10 as an example of an insulating film, and a copper layer 20 as an example of a conductive layer is fixedly bonded.

Next, by selectively etching the copper layer 20, a circuit pattern layer 21 is formed as shown in FIG. 2.

Then, after the circuit pattern layer 21 is formed, an adhesive layer (not shown) is interposed on the surface opposite to the surface on one side of the resin film 10 to fix the aluminum foil 30.

Here, the aluminum foil 30 contains: 0.5 mass% to 3.0 mass% of manganese, 0.0001 mass% to 0.2 mass% of chromium, 0.2 mass% to 1.8 mass% of magnesium, 0.0001 mass% to 0.6 mass of titanium % Or less, copper exceeding 0% by mass and 0.005% by mass or less, silicon exceeding 0% by mass and 0.1% by mass, iron exceeding 0% by mass and 0.2% by mass, and the remainder being composed of aluminum and unavoidable impurities. The aluminum foil 30 has a high strength and a high hardness by containing the above composition, for example, a hardness of 170 Hv.

Since the exothermic laminated material for a mounting substrate of the present invention manufactured as described above is provided with the aluminum foil 30 which is excellent in lightness, heat release (thermal conductivity), and bendability, it can respond to weight reduction, miniaturization, and thinness of an electronic device. Into. In addition, after the circuit pattern layer 21 is formed, an aluminum foil 30 having a predetermined strength and hardness is adhered to a surface opposite to the surface on one side of the resin film 10, so that the aluminum foil 30 has no unevenness on the surface. Thereby, even if the exothermic laminated material for a mounting substrate manufactured by the present invention is adhered to the support of a portable electronic device On the body or the frame, there is still no case where voids occur and the thermal conductivity decreases. Therefore, even if an electronic component having a large amount of heat is mounted, a heat-generating laminate for a mounting substrate that can more efficiently dissipate heat generated by the electronic component can be manufactured.

(Resin film)

The resin film 10 is intended to withstand the mounting of electronic components with solder at about 250 ° C, and preferably has a glass transition temperature (Tg) of 250 ° C or higher. In order to ensure the insulation, the resin film 10 preferably has a dielectric breakdown voltage of 5 kV or more. The resin film 10 preferably has almost no heat shrinkage, that is, the heat shrinkage rate is 0.1% or less.

The resin film 10 is preferably formed of a film containing polyimide, polyethylene naphthalate, and polyethylene terephthalate. The material of the resin film 10 is more preferably a polyimide film.

The thickness of the resin film 10 is 10 μm or more and 100 μm or less, and more preferably 10 to 50 μm in order to exhibit stable insulation and heat release properties. If the thickness of the resin film 10 is less than 10 μm, a stable insulating effect cannot be obtained. When the thickness of the resin film 10 exceeds 100 micrometers, it will become a cause of a decrease in heat radiation.

(Copper layer)

The copper layer 20 is provided in order to form a circuit by etching etc. (it is used for wiring the electronic component mounted on the exothermic laminated material for mounting substrates). Although it can be formed by forming a copper film as the copper layer 20 on the polyimide resin layer as the resin film 10 by vapor deposition, it is preferable that the copper film is formed on the resin film 10 An electrolytic copper foil as the copper layer 20 is formed by interposing an adhesive layer and an additional layer thereon.

The thickness of the copper layer 20 is in order to easily form a circuit by etching and to be in a close-packed state on the resin film 10, and is preferably 5 μm or more and 100 μm or less, and more preferably 10 to 70 μm. If the thickness of the copper layer 20 is less than 5 μm, it will be difficult to smoothly laminate the resin film 10 (without wrinkles or the like). When the thickness of the copper layer 20 exceeds 100 μm, it is difficult to precisely perform circuit formation by etching.

(Aluminum foil)

The aluminum foil 30 is provided in order to dissipate heat generated from the electronic components mounted on the circuit pattern layer 21 of the heat-dissipating laminated material for mounting substrates. An exothermic laminated material for mounting a substrate may be disposed by laminating and fixing the lower surface of the aluminum foil 30 (the surface opposite to the side on which the resin film 10 is fixed) along the support or frame of the electronic device.

The aluminum foil 30 is preferably formed of an aluminum material having a high thermal conductivity. When the exothermic laminated material for mounting substrates is laminated along the support or frame of the electronic device, it is required to have good bendability. Therefore, the aluminum foil 30 is preferably an appropriately tempered aluminum material.

The thickness of the aluminum foil 30 is in order to contribute to the lightness, miniaturization, and thickness reduction of the electronic device, and to facilitate processing and to exhibit stable heat radiation. It is preferably 20 μm or more and 350 μm or less, more preferably 80 μm or more and 300 μm or less, particularly preferably 100 μm or more and 250 μm or less. When the thickness of the aluminum foil 30 is less than 20 μm, a stable heat releasing effect cannot be obtained. If the thickness of the aluminum foil 30 exceeds 350 μm, in addition to processing difficulties, it also hinders light weight, small size, and thinness. Type.

(Adhesive layer)

In order to ensure heat resistance, the adhesive layer is preferably formed of a general-purpose epoxy-based adhesive. Although the conductive filler improves the heat release property, it reduces the insulating property, and therefore does not contain the conductive filler in the adhesive layer.

The thickness of the adhesive layer is preferably 3 μm or more and 30 μm or less in order to exhibit good adhesion and not prevent heat release. If the thickness of the adhesive layer is less than 3 μm, insufficient adhesion and uneven adhesion are likely to be caused, which may cause a decrease in heat release property. If the thickness of the adhesive layer exceeds 30 μm, the laminate between the aluminum foil 30 and the resin film 10 and the laminate between the resin film 10 and the copper layer 20 are difficult, and thus cause a decrease in heat release.

Next, the embodiments of the present invention will be specifically described. It should be noted that the embodiments shown below are for illustration only, and the present invention is not limited to the following embodiments.

(Example)

According to the steps shown in FIG. 1 to FIG. 3, a sample of an example of an exothermic laminate for mounting a substrate is prepared. In addition, for comparison, a sample of Comparative Example 1 of an exothermic laminated material for mounting a substrate was prepared by using an aluminum foil having a lower hardness than the aluminum foil used in the present invention and following the steps shown in FIGS. 1 to 3. In addition, according to the steps shown in FIGS. 4 to 5, a sample of Comparative Example 2 of an exothermic laminate for mounting substrates was prepared.

(Example)

As shown in FIG. 1, a resin film 10 is a polyimide film having a thickness of 25 μm, and an epoxy-based adhesive is interposed on one side of the film, and then laminated in a dry manner. The method is a 35 μm thick electrolytic copper foil of the copper layer 20. The thickness of the adhesive layer was 15 μm.

Next, as shown in FIG. 2, the copper layer 20 is selectively etched by using an optical lithography method to form a circuit pattern layer 21 having an arbitrary circuit shape.

Then, as shown in FIG. 3, an epoxy-based adhesive is interposed on the other surface of the resin film 10, and then, by using a dry lamination method, the content is 0.5% by mass to 3.0% by mass of manganese, and 0.0001 of chromium. Mass% or more and less than 0.2% by mass, magnesium 0.2% or more and 1.8% by mass, titanium 0.0001% or more and 0.6% by mass or less, copper exceeding 0% by mass and 0.005% by mass or less, silicon exceeding 0% by mass and 0.1 Mass% or less, iron exceeding 0% by mass and 0.2% by mass or less, and the rest consisting of aluminum and unavoidable impurities, aluminum foil 30 (hardness: 170 Hv) with a thickness of 100 μm. The thickness of the adhesive layer was 15 μm.

(Comparative example 1)

Except that instead of the aluminum foil 30 with a thickness of 100 μm used in the embodiment, the aluminum foil with a thickness of 150 μm (material 1N30, H, hardness: 50 Hv) was used. Exothermic laminate for mounting substrates.

(Comparative example 2)

As shown in FIG. 4, the resin film 10 is a polyimide film having a thickness of 25 μm. An epoxy-based adhesive is interposed on one side of the film, and then a copper layer 20 having a thickness of 35 μm is prepared by dry lamination. Foil. The thickness of the adhesive layer was 15 μm. An epoxy-based connection is provided on the other surface of the resin film 10 The adhesive is applied, and an aluminum foil (material: 1N30, H, hardness: 50 Hv) with a thickness of 150 μm is adhered by a dry lamination method.

Next, as shown in FIG. 5, by selectively etching the copper layer 20 using an optical lithography method, a circuit pattern layer 21 having an arbitrary circuit shape is formed in the same manner as in the embodiment.

In the obtained exothermic laminates for mounting substrates in the obtained Examples, Comparative Examples 1 and 2, the presence or absence of unevenness on the surface of the aluminum foil 30 was visually confirmed.

The evaluation of the unevenness is visually observed from the aluminum foil 30 side, and a part of the outline of the circuit pattern formed on the circuit pattern layer 21 is embossed, and is rated as "having unevenness." Those who were flat were rated as "no bumps".

The surface of the aluminum foil 30 of the example is free of irregularities, while the surfaces of the aluminum foil 30 of the comparative examples 1 and 2 are relatively uneven.

All the implementation forms and examples disclosed this time are only for illustration, and should not be considered as limiting. The scope of the present invention is not the above embodiments and examples, but is shown by the scope of the patent application, and covers all modifications and changes within the meaning and scope equivalent to the scope of the patent application.

(Industrial availability)

According to the present invention, it is possible to manufacture an exothermic laminate for a mounting substrate that can respond to the weight reduction, miniaturization, and thickness reduction of an electronic device, and that can efficiently dissipate heat generated by the electronic component even if an electronic component with a large amount of heat is mounted.

10‧‧‧resin film

20‧‧‧ Copper

21‧‧‧Circuit pattern layer

30‧‧‧ aluminum foil

FIG. 1 is a diagram showing a schematic cross-sectional structure of a first step of a method for manufacturing a heat-sinking laminate for mounting substrates according to an embodiment of the present invention.

FIG. 2 is a diagram showing a schematic cross-sectional structure of a second step of the method for manufacturing a heat-sinking laminate for mounting substrates according to an embodiment of the present invention.

FIG. 3 is a view showing a schematic cross-sectional structure of a third step of a method for manufacturing a heat-sinking laminate for mounting substrates according to an embodiment of the present invention.

FIG. 4 is a diagram showing a schematic cross-sectional structure of a first step of a method for manufacturing a heat-sinking laminate for mounting substrates according to a comparative example of the present invention.

FIG. 5 is a schematic cross-sectional structure diagram of the second step of the manufacturing method of the exothermic laminate for mounting substrates in the comparative example of the present invention.

10‧‧‧resin film

21‧‧‧Circuit pattern layer

30‧‧‧ aluminum foil

Claims (2)

A method for manufacturing an exothermic laminate for mounting a substrate includes the steps of: fixing a conductive layer on a surface of one side of an insulating film; and forming a circuit pattern layer by selectively etching the conductive layer. A step of fixing an aluminum foil on a surface opposite to a surface on one side of the insulating film after forming the circuit pattern layer; the aluminum foil system contains: 0.5% by mass or more and 3.0% by mass of manganese Below, 0.0001% by mass to 0.2% by mass of chromium, 0.2% by mass to 1.8% by mass of magnesium, 0.0001% by mass to 0.6% by mass of titanium, 0% by mass to 0.005% by mass of copper, and more than 0% by mass of silicon Mass% to 0.1% by mass, iron exceeding 0% by mass to 0.2% by mass, and the balance is composed of aluminum and unavoidable impurities. For example, the method for manufacturing an exothermic laminate for mounting substrates in the scope of application for a patent, wherein the above-mentioned insulating film contains polyimide, polyethylene naphthalate, polyethylene terephthalate, and polymer One selected from the group consisting of tetrafluoroethylene.