KR20120082947A - Mounting board heat dissipating laminate - Google Patents

Abstract

The present invention provides a heat dissipating laminate for a mounting substrate that can cope with light weight, miniaturization and thinning of an electronic device, and can more efficiently dissipate heat generated in the electronic device even when an electronic device having a large heat generation amount is mounted. The heat dissipation laminated material 1 for mounting board | substrate of the aluminum base material layer 11, the resin layer 13 laminated | stacked and fixed by the adhesive layer 12 on the aluminum base material layer 11, and the resin layer 13 of The copper layer or the aluminum layer 15 which is laminated | stacked and fixed through the adhesive layer 14 is provided on it.

Description

Heat dissipation laminated material for mounting board {MOUNTING BOARD HEAT DISSIPATING LAMINATE}

BACKGROUND OF THE INVENTION Field of the Invention The present invention generally relates to heat dissipating laminates for mounting substrates, and in particular, heat dissipating laminates for mounting substrates for mounting electronic devices having large heat generation amounts, for example, light emitting diodes (LEDs) and the like. A heat dissipation laminated material for mounting substrates for mounting an element.

BACKGROUND OF THE INVENTION A mounting board having circuits formed on one or both surfaces of an insulating layer is used in a wide range of fields. The circuit is formed of a copper, aluminum foil, or paste composition. The electronic element is mounted on the formed circuit. Examples of the electronic device to be mounted include a resistor, a capacitor, a transistor, and various power devices; High density integrated circuits such as MPU and CPU; Light emitting elements, such as a light emitting diode (LED) and a laser diode, and these array elements are mentioned.

In recent years, the performance required for electronic devices is further increased, and the power consumption of power devices and high-density integrated circuits tends to increase among the above-mentioned electronic devices. Moreover, the thing of high brightness is developed for a light emitting element. However, an increase in the amount of heat generated by an increase in power consumption of a power device or a high-density integrated circuit or an increase in the brightness of a light emitting device adversely affects the heat generating electronic device itself or another electronic device. For example, a malfunction of the heat-generating electronic device itself or another electronic device by heat, deterioration of performance by heat, or shortening of life by heat may be considered. Accordingly, various structures have been proposed for efficiently removing and dissipating heat generated in electronic devices.

For example, Japanese Unexamined Patent Application Publication No. 2010-3733 (Patent Document 1) proposes a structure in which an electronic element is covered with a heat radiating member. Here, the thing which made the heat resistant member contain the filler which has favorable heat conductivity in the epoxy resin which has heat resistance is used.

Further, Japanese Laid-Open Patent Publication No. 2004-172370 (Patent Document 2) proposes a structure in which a heat dissipation substrate made of a mixture of an inorganic filler having a concave-convex shape, a mixture of a thermosetting resin, and a pregel material is provided on the component mounting surface side of the circuit mounting substrate. have.

However, these structures are not useful for electronic devices that require further reduction in weight and size. For this reason, a material having heat dissipation has been employed in a laminate for mounting substrates for mounting electronic devices. As such a material, for example, "FR? 4" of general-purpose glass epoxy and "CEM3" of glass composite type in which electrolytic copper foil is laminated are used. In addition, Japanese Patent Laid-Open No. 11-5276 (Patent Document 3) proposes a configuration of a laminated board (insulating layer) for a printed circuit which is cheaper than the above materials.

On the other hand, portable electronic devices such as mobile phones, digital cameras, audio players, voice recorders, game machines, etc. have recently been required to be thinner in addition to weight reduction and miniaturization. It is effective for thinning if the mounting substrate for mounting the electronic element can be directly laminated on the support or the housing of the portable electronic device. However, even if a conventional "FR? 4" or "CEM3" material is used as a laminate for mounting boards for mounting electronic devices, insulation is not sufficient, so there is a fear of a small level of electric shock or malfunction required for portable electronic devices. Safety to prevent cannot be secured. In addition, if the above material is to be used to ensure sufficient insulation, the thickness of the material is required to some extent, and not only becomes heavy as the laminate for mounting substrate, but also the flexibility is poor. For this reason, the laminate for mounting substrate cannot be laminated (attached) so as to be in close contact with the surface of the support or the housing of the portable electronic device.

In addition, thin TVs such as liquid crystal TVs tend to be larger in recent years. However, in thin TVs, it is desired to make the TV main body as light and thin as possible, while increasing the screen size. Moreover, in order to comply with such a request, in order to reduce weight and thickness of a liquid crystal backlight device, for example, as described in Unexamined-Japanese-Patent No. 2000-340019 (patent document 4), it is a side edge type liquid crystal backlight device. It is adopted. For example, as described in Japanese Patent Laid-Open No. 2009-272451 (Patent Document 5), LED is used as a light source of a liquid crystal backlight device for thinning and reducing power consumption. The LED is mounted directly on an insulated substrate. In order to cope with this technical trend, it is necessary to radiate heat generated from the LED to the surface on the side opposite to the surface on which the LED is mounted through the laminate for mounting substrate. In particular, since the side edge type liquid crystal backlight device mounts a large number of LEDs per unit area due to its structure, high heat dissipation is required by the laminate for mounting substrate.

Patent Document 1: Japanese Patent Application Laid-Open No. 2010-3733 Patent Document 2: Japanese Patent Application Laid-Open No. 2004-172370 Patent Document 3: Japanese Patent Laid-Open No. 11-5276 Patent Document 4: Japanese Patent Laid-Open No. 2000-340019 Patent Document 5: Japanese Unexamined Patent Application Publication No. 2009-272451

Accordingly, an object of the present invention is to provide a heat dissipation laminate for a mounting substrate that can cope with light weight, miniaturization and thinning of an electronic device, and can more efficiently dissipate heat generated in the electronic device even when an electronic device having a large heat generation amount is mounted. will be.

In order to achieve the above object, the inventors earnestly examined the structure of the material which can have not only the insulation originally required for the heat dissipation laminated material for mounting substrates, but also heat dissipation, flexibility, and light weight. This invention is made | formed based on the knowledge of the inventor obtained by the said examination result.

That is, the heat dissipation laminate for mounting substrates according to the present invention includes an aluminum base layer, a resin layer laminated and adhered on the aluminum base layer via an adhesive layer, and a copper layer laminated and fixed on the resin layer via an adhesive layer. (Iii) or an aluminum layer.

In the heat dissipation laminated material for mounting substrates of the present invention, the thickness of the aluminum base layer is preferably 20 µm or more and 350 µm or less.

Moreover, in the heat radiation laminated material for mounting board | substrates of this invention, it is preferable that the glass transition temperature of a resin layer is 250 degreeC or more.

Moreover, in the heat radiation laminated material for mounting board | substrates of this invention, it is preferable that the dielectric breakdown voltage of a resin layer is 5 kV or more.

Moreover, in the heat radiation laminated material for mounting board | substrates of this invention, it is preferable that the thickness of a resin layer is 10 micrometers or more and 100 micrometers or less.

Moreover, in the heat radiation laminated material for mounting board | substrates of this invention, it is preferable that a resin layer contains polyimide, polyethylene naphthalate, polyethylene terephthalate, a fluorinated resin, or a fluorinated resin copolymer.

In the heat dissipation laminated material for mounting substrates of the present invention, the thickness of the adhesive layer is preferably 3 µm or more and 30 µm or less.

According to the present invention, since the heat dissipation laminate for a mounting substrate includes an aluminum base layer excellent in light weight, heat dissipation (thermal conductivity) and flexibility, and a resin layer for insulating property, it is possible to cope with light weight, miniaturization and thinning of electronic devices. Even if an electronic element having a large amount of heat generation is mounted, it becomes possible to dissipate heat generated in the electronic element more efficiently.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows schematic sectional structure of the heat radiation laminated material for mounting board | substrates as one Embodiment which concerns on this invention.

EMBODIMENT OF THE INVENTION Hereinafter, one Embodiment of this invention is described based on drawing.

As shown in FIG. 1, the heat-dissipating laminate 1 for the mounting substrate includes an aluminum base layer 11, a resin layer 13 laminated and adhered on the aluminum base layer 11 via an adhesive layer 12, and And the copper layer 15 laminated and fixed on the resin layer 13 via the adhesive layer 14.

(Aluminum base layer)

The aluminum base layer 11 is provided so as to dissipate heat generated from an electronic element mounted on the copper layer 15 of the heat dissipation laminate 1 for the mounting substrate. The heat dissipation laminate 1 for the mounting substrate may be disposed so that the bottom surface (the opposite side of the side on which the resin layer 13 is fixed) to the aluminum base layer 11 is laminated and adhered along the support or the housing of the electronic device.

The aluminum base layer 11 is preferably formed of an aluminum material (aluminum foil) having high thermal conductivity, and particularly preferably made of an aluminum material of high purity (high purity of an industrial level such as JIS-based 1000 system). When using a refined aluminum material, it is preferable to use a hard aluminum material (JIS no. H18) which is easy to handle as a laminated material. Since the flexibility is required when laminating the heat dissipating laminate 1 for the mounting substrate along the support or the housing of the electronic device, it is preferable that the aluminum base layer 11 uses an appropriately tempered aluminum material.

The thickness of the aluminum base layer 11 is preferably 20 µm or more and 350 µm or less, more preferably 80 µm in order to contribute to light weight, miniaturization, and thickness of the electronic device, to facilitate processing, and to exhibit stable heat dissipation. 300 micrometers or less, More preferably, they are 100 micrometers or more and 250 micrometers or less. When the thickness of the aluminum base material layer 11 is less than 20 micrometers, the effect of stable heat dissipation cannot be acquired. If the thickness of the aluminum base material layer 11 exceeds 350 micrometers, processing will become difficult and it will interfere with light weight, compactness, and thickness reduction.

(Resin layer)

The resin layer 13 preferably has a glass transition temperature (Tg) of 250 ° C. or higher so that the resin layer 13 can withstand mounting of an electronic device by about 250 ° C. solder. In addition, in order to ensure insulation, the resin layer 13 preferably has an insulation breakdown voltage of 5 kV or more. In addition, it is preferable that the resin layer 13 has little thermal contraction, that is, the thermal contraction rate is 0.01% or less.

The resin layer 13 is preferably formed of a film containing polyimide, polyethylene naphthalate, polyethylene terephthalate, fluorinated resin, or fluorinated resin copolymer, and particularly as a material of the resin layer 13, a polyimide film This is suitably used. As the fluorinated resin used for the resin layer 13, for example, polyvinyl fluoride (PVF), polyvinylidene fluoride (PVDF), or polytetrafluoroethylene (PTFE) is suitable. Moreover, as a copolymer of fluorinated resin used for the resin layer 13, the ethylene copolymer (ETFE) of tetrafluoroethylene is suitable, for example.

In order for the thickness of the resin layer 13 to exhibit stable insulation and heat dissipation, 10 micrometers or more and 100 micrometers or less are preferable, More preferably, it is 10-50 micrometers. When the thickness of the resin layer 13 is less than 10 micrometers, the stable insulating effect cannot be acquired. When the thickness of the resin layer 13 exceeds 100 micrometers, it will become a cause of a heat radiation fall.

(Copper layer)

The copper layer 15 is provided in order to form the circuit for wiring the electronic element mounted on the heat radiation laminated material 1 for mounting substrates by etching etc. Although the copper film as the copper layer 15 may be deposited on the polyimide resin layer as the resin layer 13, the electrolytic copper (copper) as the copper layer 15 may be formed on the resin layer 13 via the adhesive layer 14. ) You may laminate | stack foil.

The thickness of the copper layer 15 is preferably 5 µm or more and 100 µm or less, more preferably 10 to 70 µm, in order to easily form a circuit by etching and to laminate the resin layer 13 in close contact with the resin layer 13. . When the thickness of the copper layer 15 is less than 5 micrometers, it becomes difficult to laminate | stack on the resin layer 13 neatly (so that wrinkles etc. may not arise). If the thickness of the copper layer 15 exceeds 100 micrometers, accurate circuit formation by an etching will become difficult.

In addition, in the heat-radiation laminated material 1 for mounting boards, the aluminum layer may be provided instead of the copper layer 15. That is, the aluminum layer may be laminated on the resin layer 13 instead of the copper layer 15. The aluminum layer may be deposited on the resin layer 13, or may be laminated on the resin layer 13 through the adhesive layer 14.

(Adhesive layer)

The adhesive layers 12 and 14 are preferably formed of a general-purpose epoxy adhesive to ensure heat resistance. The conductive filler increases the heat dissipation, but does not include the conductive filler in the adhesive layers 12 and 14 because it lowers the insulation.

It is preferable that each thickness of the contact bonding layers 12 and 14 is 3 micrometers or more and 30 micrometers or less in order to exhibit favorable adhesiveness and not to interfere with heat dissipation. When the thickness of each of the adhesive layers 12 and 14 is less than 3 µm, insufficient adhesion and adhesion unevenness tend to occur, which causes a decrease in heat dissipation. When the thickness of each of the adhesive layers 12 and 14 exceeds 30 m, it becomes difficult to laminate the aluminum base layer 11, the resin layer 13, the resin layer 13 and the copper layer 15. do.

Next, embodiments of the present invention will be described in detail. In addition, the Example shown below is an example and this invention is not limited to the following Example.

Example

The sample of the Example of the heat dissipation laminated material 1 for mounting board | substrates shown in FIG. 1 was produced. For comparison, the properties of the conventional heat dissipating laminate for mounting substrates were measured.

(Example 1)

As the resin layer 13, the polyimide film whose glass transition temperature (Tg) is 310 degreeC, the dielectric breakdown voltage is 9.4 kV, the thermal contraction rate is 0%, and thickness is 25 micrometers was prepared. Each characteristic value of glass transition temperature, the dielectric breakdown voltage, and the thermal contraction rate was measured by the method of mentioning later.

An electrolytic copper foil having a thickness of 35 μm was bonded to one surface of the resin layer 13 by a dry lamination method using an epoxy adhesive. The formed adhesive layer 14 had a thickness of 15 μm.

On the other side of the said resin layer 13, the aluminum foil whose thickness is 150 micrometers as the aluminum base material layer 11 was adhere | attached by the dry lamination method using an epoxy adhesive. The formed adhesive layer 12 had a thickness of 15 μm.

The breakdown voltage and thermal conductivity of the heat-dissipating laminated material 1 for mounting board | substrates manufactured as mentioned above were measured by the method of mentioning later. The result is shown in Table 1 with the thickness of the heat radiation laminated material 1 for mounting board | substrates.

(Conventional example 1)

The dielectric breakdown voltage and thermal conductivity of FR-4 (model number: R-1700 made by Panasonic Denko Co., Ltd.) which are commercially available heat-radiation laminated materials which laminated | stacked 35 micrometers thick electrolytic copper foil on glass epoxy resin were measured similarly. The result is shown in Table 1 with the thickness of the heat radiation laminated material for mounting board | substrates.

(Conventional example 2)

The dielectric breakdown voltage and thermal conductivity of CEM3 (Model No. R: 1786 manufactured by Panasonic Denko Co., Ltd.), which is a commercially available heat-dissipating laminate for laminating an electrolytic copper foil having a thickness of 35 μm on a glass composite resin, were measured in the same manner. The result is shown in Table 1 with the thickness of the heat radiation laminated material for mounting board | substrates.

Each characteristic value of the polyimide film as the resin layer 13 used for producing the heat dissipation laminated material 1 for mounting board | substrates of Example 1 was measured as follows.

(Glass transition temperature)

The glass transition temperature of the polyimide film was measured based on JIS K7121 and JIS K7122 using a differential scanning calorimeter (DSC).

(Breakdown voltage)

In accordance with JIS C2110: 1994, the voltage to be applied in the air at a temperature of 25 ± 5 ° C. and a relative humidity of 65 ± 5% was increased from 0 V at a rate of 1000 V for 1 second to measure the dielectric breakdown voltage of the polyimide film.

After preparing 10 pieces of polyimide films of the size of 200 mm x 200 mm and measuring 3 points per sheet, the remaining 20 points were discarded by each of the five values of the higher and lower values. The average value was obtained. This average value was evaluated as the dielectric breakdown voltage of the polyimide film.

(Heat shrinkage)

Five test pieces of a polyimide film having a width of 20 mm and a length of 150 mm were collected in the longitudinal direction and the transverse direction of the original polyimide film, respectively. Two marks were marked at a distance of about 100 mm at the center of each test piece. The distance between two marks was measured for each test piece (distance between marks before heating). And in accordance with JIS C2318: 1988, each test piece of the polyimide film is vertically suspended in a constant temperature box maintained at a temperature of 150 ° C. ± 3 ° C., heated for 2 hours, and then taken out of the constant temperature box for 30 minutes, and the test piece is placed at room temperature for 30 minutes. After standing, the distance between two marks was measured for each test piece (distance between marks before heating). For each test piece, the average value of the distance between the gauges measured before and after heating was determined. The heating shrinkage ratio of the polyimide film was calculated by substituting the average value of the distance between the marks before and after the heating in the following equation.

Heating shrinkage percentage (%) = ((L ₁ -L ₂ ) / L ₁ ) × 100

L ₁ : Distance between marks before heating (mm)

L ₂ : Distance between marks after heating (mm)

Insulation breakdown voltage and thermal conductivity of the heat dissipation laminated material 1 for mounting board | substrates of Example 1 and the heat dissipation laminated material for mounting boards of the conventional examples 1-2 were measured as follows.

(Breakdown voltage)

In accordance with ASTM D149, the voltage to be applied in the air at a temperature of 25 ± 5 ° C. and a relative humidity of 65 ± 5% was raised from 0 V at a rate of 500 V for 1 second to measure the dielectric breakdown voltage of the heat-radiating laminate for mounting substrate.

After preparing 10 sheets of heat-dissipating laminates for mounting substrates having a size of 100 mm x 100 mm and measuring three points for one sheet, the total measured values were discarded five of each of the values of the higher and lower values. The average value of 20 points was calculated | required. This average value was evaluated as the dielectric breakdown voltage of the heat dissipation laminated material for mounting substrates.

(Thermal conductivity)

The thermal conductivity of the heat-dissipating laminated material for mounting board | substrates was measured by the laser flash method using the passion water measuring apparatus (product number: TC-7000 of the ulvac-liko Co., Ltd. product).

Total thickness
[Mu m] Thermal conductivity
[W ／ mK] Dielectric breakdown voltage
[kV / mm] Example 1 240 0. 85 49 Conventional Example 1 1600 0. 37 60 Conventional Example 2 1600 0. 45 52

From the results in Table 1, the heat dissipation laminate 1 for the mounting substrate of Example 1 has a thinner layer thickness compared to the heat dissipation laminate for the mounting substrates of the conventional examples 1 to 2, resulting in excellent flexibility, high thermal conductivity, and It turns out that it shows the dielectric breakdown voltage of the same level as the heat-radiation laminated material for mounting board | substrates of Examples 1-2.

(Example 2)

In Example 2, aluminum was used instead of the copper of Example 1. In Example 2, an aluminum foil 1N30 material hard 50 µm foil manufactured by Toyo Aluminum Co., Ltd. was bonded to one surface of the resin layer 13 as the aluminum layer 15.

The dielectric breakdown voltage and the thermal conductivity of the heat dissipation laminate 1 for mounting substrates of Example 2 were measured in the same manner as in Example 1. The results are shown in Table 2.

Total thickness
[Mu m] Thermal conductivity
[W ／ mK] Dielectric breakdown voltage
[kV / mm] Example 2 255 0. 83 49

From the results in Table 2, the heat dissipation laminate 1 for the mounting substrate of Example 2 is thinner than the heat dissipation laminate for the mounting substrates of the conventional examples 1 to 2 (see Table 1), and thus has excellent flexibility and a high thermal conductivity. It turns out that it is high and exhibits the dielectric breakdown voltage of the same level as the heat-radiation laminated material for mounting boards of the prior art examples 1-2.

It should be understood that the disclosed embodiments and examples are merely illustrative in all respects and not restrictive. The scope of the present invention is shown not by the above embodiments and examples but by the claims, and is intended to include all modifications and variations within the meaning and range equivalent to the claims.

Industrial availability

Since the heat dissipation laminate for mounting boards of the present invention includes an aluminum substrate layer excellent in light weight, heat dissipation (thermal conductivity) and bendability, and a resin layer which insulates insulation, it is possible to cope with light weight, miniaturization and thinning of electronic devices. Even if this large electronic element is mounted, it becomes possible to dissipate heat generated by the electronic element more efficiently.

1: Heat dissipation laminate for mounting board
11: aluminum base layer
12, 14: adhesive layer
13: resin layer
15: copper layer
15: aluminum layer

Claims (7)

Aluminum base layer 11,
A resin layer 13 laminated and fixed on the aluminum base layer 11 via an adhesive layer 12;
A copper layer or an aluminum layer 15 laminated and fixed on the resin layer 13 via an adhesive layer 14.
Heat dissipation laminated material (1) for mounting boards.
The method of claim 1,
The thickness of the aluminum base material layer 11 is 20 micrometers or more and 350 micrometers or less
Heat dissipation laminated material (1) for mounting boards.
The method of claim 1,
The glass transition temperature of the said resin layer 13 is 250 degreeC or more
Heat dissipation laminated material (1) for mounting boards.
The method of claim 1,
The dielectric breakdown voltage of the resin layer 13 is 5 kV or more.
Heat dissipation laminated material (1) for mounting boards.
The method of claim 1,
The thickness of the said resin layer 13 is 10 micrometers or more and 100 micrometers or less
Heat dissipation laminated material (1) for mounting boards.
The method of claim 1,
The resin layer 13 includes one selected from the group consisting of polyimide, polyethylene naphthalate, polyethylene terephthalate, fluorinated resin, or fluorinated resin copolymer.
Heat dissipation laminated material (1) for mounting boards.
The method of claim 1,
The thickness of the said adhesive layers 12 and 14 is 3 micrometers or more and 30 micrometers or less
Heat dissipation laminated material (1) for mounting boards.

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