JP2020141142A - Flame-retardant heat dissipation sheet - Google Patents

Abstract

To provide a flame-retardant heat dissipation sheet that is flame retardant and has excellent heat dissipation effect and workability.SOLUTION: A flame-retardant heat dissipation sheet includes a heat conduction diffusion layer 100, a heat dissipation layer 200 laminated on one surface of the heat conduction diffusion layer 100, and a heat conductive adhesive layer 300 laminated on the other surface of the heat conduction diffusion layer 100. A release paper 400 is laminated on the heat conductive adhesive layer 300. Moreover, the heat conductive adhesive layer 300 includes a solid flame retardant, a soluble flame retardant, and a heat conductive filler as flame retardant functional materials in a heat resistant pressure adhesive, and the solid flame retardant and the heat conductive filler have a smaller diameter than the thickness dimension of the heat conductive adhesive layer 300..SELECTED DRAWING: Figure 1

Description

The present invention relates to, for example, a flame-retardant heat-dissipating sheet that dissipates heat from an electronic device.

The power consumption of the parts constituting the electric device, the electronic device, and the like is increased due to the improvement of the degree of integration and the improvement of the operating speed, and as a result, the amount of heat generated is increased. As the amount of heat generated increases, the temperature of the component itself rises. It is desired to suppress the temperature rise of the parts because the temperature rise of the parts leads to the malfunction of the parts, the shortening of the life due to the failure, the occurrence of burns to the user, and the like.
As a means for suppressing a temperature rise, a technique of bringing a heat radiating plate into contact with a component is known. By bringing the heat radiating plate into contact with the component, the heat generated in the component is conducted to the heat radiating plate, and as a result, the temperature rise of the component can be suppressed.
A material having high thermal conductivity such as metal, a metal sheet or a graphite sheet is used for the heat radiating plate. There is also a method of improving the radiation performance by performing surface treatment such as an oxide film (alumite treatment, metal heat sink) or resin coating (resin coating on the housing).

However, if the difference between the heat radiating plate temperature and the outside air temperature is small, the heat accumulated in the heat radiating plate will not be discharged and will remain accumulated in the heat radiating plate. Therefore, there is still room for improvement in the heat radiating plate as a means for suppressing the temperature rise.
In addition, when a metal sheet or graphite sheet is used, laminating with a resin film or the like is required to prevent a short-circuit accident, which causes an increase in cost and cannot be used for thin electronic devices. There is a problem.
Further, since the formation of the oxide film or the like is processed on the electronic component or the base material itself, consideration from the design stage is required, which makes retrofitting difficult. In addition, since partial heat treatment is difficult, the product design itself may be difficult.

Therefore, the heat-radioactive film and the heat-radioactive adhesive tape described in JP-A-2014-160718 were devised.

Japanese Unexamined Patent Publication No. 2014-160718

However, the above-mentioned heat radioactive film and the like have a problem of flame retardancy and have a problem that they cannot be used around a power supply device.

The present invention has been devised in view of the above circumstances, and an object of the present invention is to provide a flame-retardant heat-dissipating sheet having flame-retardant properties and surface insulating properties, and having excellent heat dissipation effect and workability.

The flame-retardant heat-dissipating sheet according to the present invention comprises a heat-conducting diffusion layer, a heat-dissipating layer laminated on one surface of the heat-conducting diffusion layer, and a heat-conducting adhesive layer laminated on the other surface of the heat-conducting diffusion layer. I have.

The heat conductive diffusion layer is a copper foil, the heat radiation layer is a flame-retardant heat-dissipating paint, and the heat conductive adhesive layer is a mixture of a heat-resistant adhesive and a flame-retardant functional material.

Further, the flame retardant functional material contains a solid flame retardant, a soluble flame retardant and a heat conductive filler.

Moreover, among the flame-retardant functional materials, the solid flame retardant and the heat-conducting filler have a diameter smaller than the thickness dimension of the heat-conducting adhesive layer.

It is preferable that a release paper is laminated on the heat conductive adhesive layer.

The flame-retardant heat-dissipating sheet according to the present invention is excellent in workability because it can be directly attached to an electronic component or the like that requires heat dissipation.
Further, since this flame-retardant heat-dissipating sheet has flame-retardant properties, it has an advantage that it can be used around a power supply device, which cannot be handled by conventional ones.
Further, in the flame retardant heat dissipation sheet according to the present invention, since the solid flame retardant and the soluble flame retardant are used in combination as the flame retardant functional material constituting the heat conductive adhesive layer, the amount of the flame retardant used can be reduced. , Adhesive strength can be secured. That is, if a large amount of only the solid flame retardant is used as the flame retardant, the heat-resistant adhesive added because the solid flame retardant is a powder type becomes dry and dry, and as a result, the adhesive strength decreases. However, the adhesive strength is ensured by using not only the solid flame retardant but also a liquid type soluble flame retardant with high adhesive strength.

Moreover, since the particle size of the flame-retardant functional material is made smaller than the thickness of the heat conductive adhesive layer, it is considered that the surface of the heat conductive adhesive layer becomes flatter and the adhesive strength is improved.

It is the schematic sectional drawing of the flame-retardant heat-dissipating sheet which concerns on embodiment of this invention. It is a graph which shows the heat dissipation effect by providing the heat dissipation layer in the flame-retardant heat dissipation sheet which concerns on embodiment of this invention.

As shown in FIG. 1, the flame-retardant heat-dissipating sheet 1000 according to the embodiment of the present invention includes a heat-conducting diffusion layer 100, a heat-dissipating layer 200 laminated on one surface of the heat-conducting diffusion layer 100, and the heat conduction. It has a heat conductive adhesive layer 300 laminated on the other surface of the diffusion layer 100. The release paper 400 is laminated on the heat conductive adhesive layer 300. The release paper 400 protects the heat conductive adhesive layer 300 and is peeled off before use.
In FIG. 1, the thickness of each part is exaggerated for the convenience of drawing.

First, as the heat conductive diffusion layer 100, a copper foil having a thickness of 35 μm is used, but the thickness may be 5 to 200 μm. Further, the thicker the heat conductive diffusion layer 100, the better the heat dissipation performance. If an aluminum foil is used for the heat conductive diffusion layer 100, it can be constructed at a low cost, but there is a problem that the heat dissipation performance is lowered because the heat conductivity is halved.
In the case of a 10 mm square 35 μm thick aluminum foil, the thermal conductivity of aluminum is 200 W / m. If K, the thermal resistance is as follows.
Thermal resistance of aluminum = 1 ÷ 200 × 0.035 ÷ (10 × 10) × 1000
= 0.00175K / W
On the other hand, in the case of a 10 mm square 35 μm thick copper foil, the thermal conductivity of copper is 420 W / m. If K, the thermal resistance is as follows.
Thermal resistance of copper = 1 ÷ 420 × 0.035 ÷ (10 × 10) × 1000
= 0.00083K / W
That is, when an aluminum foil is used for the heat conduction diffusion layer 100, heat resistance is generated about twice as much, so that the heat dissipation performance is deteriorated.

As the heat radiating layer 200, an acrylic urethane resin is used as a main agent, and a heat radiating material, a dispersant, a precipitation inhibitor, a diluting solvent, a solid flame retardant, a curing agent and the like are mixed therein.
The composition composition ratio is 10 to 40% (preferably 32.8%) for the acrylic urethane resin, 0.5 to 45% (desirably 11.3%) for the heat radiating material, and 0.2 to 1 for the dispersant. 5% (preferably 0.5%), anti-settling agent 0.2-1.5% (preferably 0.5%), diluent solvent 5-45% (preferably 5.0%), solid difficulties The fuel is 15-50% (preferably 28.5%) and the hardener is 5-30% (preferably 21.4%).
Since the heat radiating layer 200 has an insulating property, it does not cause a short circuit accident even if it is used inside an electronic device.
The composition of the heat radiating material was 0.5 to 45% (preferably 11.3%) in order to maintain the adhesion to the substrate after coating.
Further, since the amount of the solid additive (solid flame retardant, heat radiating material, etc.) is large, the dispersant is added to 0.2 in order to suppress the separation of the acrylic urethane resin and the additive in the paint liquid when the paint liquid is stored. By adding ~ 1.5% (preferably 0.5%) and 0.2 to 1.5% (preferably 0.5%) of the anti-precipitation agent, separation of the coating liquid is suppressed and quality stability is ensured. did.

As the acrylic urethane resin, select one that is transparent so as not to interfere with the heat dissipation material, and that is flexible and has a hard surface. By selecting a transparent material, the infrared radiation effect of earth-like graphite, which is a heat radiating material, can be enhanced. Flexibility is required because the flame-retardant heat-dissipating sheet 1000 needs to be bent.
Further, as the heat radiating material, earth-like graphite having an average particle size of 5 μm is used. The heat-dissipating material alone has a particle size of 5 μm or less, but when aggregated, the particle size becomes a maximum of 105 μm. As the heat radiating material, carbon-based or ceramic-based materials can be used in addition to earth-like graphite.
Further, as the diluting solvent, one in which the acrylic urethane resin as the main agent is dissolved, for example, n-butyl acetate is used.

As the curing agent, as with acrylic urethane resin as the main agent, select one that is transparent so as not to interfere with the heat radiating material, and that is flexible and has a hard surface.
Further, as the solid flame retardant, ammonium polyphosphate coated with melamine is used. In addition, as the solid flame retardant, an inorganic flame retardant such as a metal oxide and an organic flame retardant such as a phosphorus can also be used. As this solid flame retardant, one having an average particle size of 7 to 16 μm is used. This is because the heat radiation layer 200 has a film thickness of 20 μm, and therefore, in order to improve the appearance and productivity, a material having a particle size smaller than the film thickness is used so that unevenness is not formed.
Dispersants and anti-precipitants are also used to stabilize the quality of the paint.

The heat radiating layer 200 is mixed with an acrylic urethane resin, a heat radiating material, a dispersant, an inhibitor of precipitation, a diluting solvent, and a solid flame retardant, and then passed through a bead mill a plurality of times to reduce the particle size of each to 20 μm or less. In particular, since the maximum particle size when the heat radiating material is aggregated is 105 μm, pulverization by this bead mill is important.

It was found that the degree of mixing of the flame retardant with the paint constituting the heat radiating layer 200 is related to the degree of adhesion between the heat radiating layer 200 and the heat conductive diffusion layer 100 and the flame retardancy.
Experiments were conducted in accordance with the UL94V test for flame retardancy and the JIS K5600-5-6 test for adhesion.
The experimental results are shown in Table 1 below.

As shown in Table 1 above, considering the flame retardancy and the adhesion to the heat conductive diffusion layer 100, the minimum line is a mixing ratio of the flame retardant of 30%.
For safety reasons, a mixing ratio of at least 40% or more is desirable.
Acrylic urethane resin, which is the main component of paint, is a flammable material, so it is necessary to mix a large amount of flame retardant.
However, if too much flame retardant is added, the paint will not become liquid because the flame retardant is powder. In addition, if too much flame retardant is added, the viscosity becomes too high and frictional heat is generated during manufacturing, which is not suitable for mass production.
On the other hand, if the amount of flame retardant is small, flame retardancy cannot be ensured and there is a problem that combustion occurs.

Therefore, in order to at least set the mixing ratio of the flame retardant to 30% and maintain an appropriate viscosity as a paint, the following measures were added.
The viscosity was reduced by adding an additional 10% diluting solvent. This solves the problem that mass production cannot be performed due to frictional heat.
In the above formulation, it is optimal to add 5 to 45% (preferably 5.0%) of a diluting solvent. If it is out of this range, flame retardancy, heat dissipation, adhesion, mass productivity due to frictional heat, quality stability, etc. cannot be ensured, so the blending amount within the range is important.
In addition, by adding a flame retardant little by little, the increase in viscosity was moderated and the frictional heat was alleviated.
Furthermore, a highly solid and flexible acrylic urethane resin was used so that the coating film would not crack even when diluted.
In order to solve the problem that a large amount of flame retardant cannot be added, a highly viscous and high solid content acrylic urethane resin was used as the main agent.

By providing the heat radiating layer 200, the heat radiating effect of the flame-retardant heat radiating sheet 1000 is enhanced.
In order to confirm such an effect, those with and without the heat radiating layer 200 were compared under the following conditions. As a comparative example, the surface temperature of only the resistor, which is a heating element, was also measured.
A 1Ω resistor is fixed to the test sample using a heat conductive double-sided adhesive tape, installed in a constant temperature and humidity chamber with an ambient temperature of 25 ° C, and a voltage of 1.5V is applied to the resistor for 2000 seconds. The surface temperature of was measured.
(1) Only the heating element to which the flame-retardant heat-dissipating sheet 1000 or a similar one is not attached, and (2) When the flame-retardant heat-dissipating sheet 1000 having the heat-dissipating layer 200 is attached to the heating element, (2) 3) Table 2 below shows the temperature after 2000 seconds when a sheet without the heat radiation layer 200 is attached to the heating element.
The result is shown in FIG.

From Table 2 as well, it can be seen that the presence of the heat radiating layer 200 improves the heat radiating effect of the flame-retardant heat radiating sheet 1000.

In addition, the coating process of the heat radiating layer 200 to the heat conductive diffusion layer 100 was also devised.
Generally, coating on a metal foil such as copper foil is performed by a bonding process from transfer, but since the flame retardant heat radiating paint constituting the heat radiating layer 200 is highly filled with a flame retardant or a heat radiating material, Since the amount of acrylic urethane resin that is the main component that adheres to the heat conductive diffusion layer 100 is small, adhesion cannot be ensured in the bonding process from transfer.
Therefore, the coating step of the heat radiating layer 200 to the heat conductive diffusion layer 100 can be mass-produced by using both the direct coating method and the floating drying method.

First, the general coating process is as follows.
The paint is applied to the transfer film, passed through a drying oven, and wound into a roll.
The base material to which the paint is to be applied (in this case, the heat conductive diffusion layer 100) is set, and the paint is transferred to the base material by pressing the transfer film coated with the paint against the base material.
This method has the advantage that since the transfer film has flexibility, it can be applied to some extent with a thick and strong base material.
However, since the flame-retardant heat-dissipating paint is two-component, when it is applied to a transfer film and passed through a drying oven, the surface of the coating film dries and cannot be transferred to a base material.

On the other hand, in the direct coating method, the flame-retardant heat-dissipating paint is directly applied to the base material to be coated (in this case, the heat conductive diffusion layer 100), passed through a drying furnace, and wound into a roll. At the time of this winding, the base material is wound at high speed through a windless zone and a forced hot air blowing zone while applying strong tension.
However, in this direct coating method, the heat conductive diffusion layer 100, which is a copper foil, has a certain thickness and high strength, so that each device is worn and damaged. In addition, there is a problem that metal powder generated during abrasion is mixed into the product.
Therefore, this direct coating method alone cannot be used.

In order to solve this problem, the direct coating method and the floating drying method were used in combination.
That is, after the flame-retardant heat-dissipating paint is directly applied to the base material to be applied (in this case, the heat conduction diffusion layer 100), the base material is introduced into the drying furnace in a state of being floated by the wind. Since the base material is floated by the wind, even if the base material is hard, each device will not be damaged. In addition, since heat is also transferred uniformly, a uniform high-quality dry film is formed on the surface of the base material.

Further, the heat conductive adhesive layer 300 has a thickness dimension of 35 μm. The heat conductive pressure-sensitive adhesive used as the heat conductive pressure-sensitive adhesive layer 300 is mainly composed of an acrylic resin-based heat-resistant pressure-sensitive adhesive, and is a soluble flame retardant, a solid flame retardant, a heat conductive filler, and a curing agent as flame retardant functional materials. Use a mixture of.
The composition composition ratio is 30 to 70% (preferably 61.8%) for the heat-resistant adhesive, 5 to 40% (desirably 10.4%) for the soluble flame retardant, and 10 to 60% (preferably 10.6%) for the solid flame retardant. The amount is preferably 25.8%), the heat conductive filler is 1 to 5% (desirably 1.4%), and the curing agent is 0.3 to 3% (desirably 0.6%).

The heat-resistant pressure-sensitive adhesive as the main component of the heat-conducting pressure-sensitive adhesive that constitutes the heat-conducting pressure-sensitive adhesive layer 300 is an acrylic resin having excellent heat resistance, particularly excellent heat resistance in a heated state. To use.
Further, as the soluble flame retardant, a phosphazene-based one having a high affinity that is well mixed with the heat-resistant pressure-sensitive adhesive is selected.
As the curing agent, an isocyanate compound is selected, which has a high affinity and is well mixed with the heat-resistant pressure-sensitive adhesive.
As the solid flame retardant, melamine-coated ammonium polyphosphate or the like is used, and an average particle size of 7 to 16 μm is used.
As the heat conductive filler, a compound such as iron, silicon, magnesium, zinc, oxygen, etc., which is spheroidized and has a particle size of 35 μm or less is used.

The important point of this heat-resistant adhesive is that it has sufficient flame retardancy and thermal conductivity, and also has sufficient adhesive strength.
Generally, in order to ensure flame retardancy and thermal conductivity, it is important to mix a flame retardant functional material with the heat-resistant adhesive which is the main ingredient. However, there is a problem that the adhesive strength is lowered simply by mixing the flame-retardant functional material.

In order to solve this problem, the following measures were taken in the production of the heat-resistant adhesive. (1) The particle system of the flame-retardant functional material is made smaller than the thickness of the heat conductive adhesive layer 300.
(2) Optimize the dispersion of flame-retardant functional materials with respect to heat-resistant adhesives.
(3) Optimize the order of addition of flame-retardant functional materials.
(4) A solid type and a liquid type are used together as a flame retardant of a flame retardant functional material.

(1) Particle size of flame-retardant functional material First, in order to make the particle size of the flame-retardant functional material smaller than the thickness (35 μm) of the heat conductive adhesive layer 300, a solid which is one of the flame-retardant functional materials. As the flame retardant, a small flame retardant having an average particle size of 7 to 16 μm was selected, and as the heat conductive filler, a flame retardant smaller than 35 μm was selected by spheroidizing.
If the particle size of the flame-retardant functional material is smaller than the thickness (35 μm) of the heat conductive adhesive layer 200, the surface of the heat conductive adhesive layer 300 becomes flatter, and it is considered that the adhesive strength is improved.

(2) Dispersion of flame-retardant functional materials In addition, in order to optimize the dispersion of flame-retardant functional materials with respect to the high-viscosity heat-resistant adhesive that is the main ingredient, the flow in the stirring tank is perpendicular to the axial direction. This was done with a width current (radiant flow) that produces a directional flow.
In the case of a wide flow, it is possible to draw in a substance mixed from the upper surface to the bottom surface, and it is possible to generate a turbulent flow and a large shearing force. This width flow can be generated by a melting type stirring blade, a dissolver type stirring blade, or the like.
The particle size of the solid flame retardant is originally about 16 μm, but in reality, some of the solid flame retardants are condensed to about 50 μm. These large particles contributed to the decrease in adhesive strength.

In a high-viscosity fluid such as a heat-resistant adhesive, a width flow having a large shearing force and a physical destructive force is required to break up a fluid containing condensed and enlarged particles such as a solid flame retardant. Is the best.
When stirring is started, resistance is added to the heat-resistant adhesive and the heat-resistant adhesive around the stirring blade becomes hard. By directly colliding the hardened heat-resistant adhesive with the solid flame retardant, the condensed and enlarged particles of the solid flame retardant are physically destroyed and made smaller.

Note that the flow form other than the width flow, for example, the axial flow which is a flow parallel to the stirring axis direction and the swirling flow which is a flow rotating in the same direction as the stirring axis has the effect of lifting the settled one upward, but shearing. Due to its weak force and physical destructive force, it seems that the ability to crush solid flame retardants is inferior among high-viscosity heat-resistant adhesives.

(3) Order of addition of flame-retardant functional materials Furthermore, the order of addition of flame-retardant functional materials was optimized.
When a large amount of the flame-retardant functional material was added to the heat-resistant adhesive having a high viscosity, it was found that the surface area and surface condition of the flame-retardant functional material had a great influence on the adhesive strength.
That is, when a large amount of the flame-retardant functional material is added, the surface area of the flame-retardant functional material increases, which leads to an increase in the viscosity of the flame-retardant functional material. At the same time, an agglutination reaction occurs due to the surface condition of the flame-retardant functional material (surface tension due to the difference in affinity between the materials). As a result of these, the adhesive strength is reduced.

In general, a flame-retardant functional material was first added to a heat-resistant pressure-sensitive adhesive as a main ingredient, and then a diluent and a curing agent were added in this order.
However, in this general order, since the flame-retardant functional material is first added to the heat-resistant adhesive having a high viscosity, the surface area is increased and the viscosity is increased.
Therefore, the heat conductive pressure-sensitive adhesive constituting the heat-conducting pressure-sensitive adhesive layer 300 of the flame-retardant heat-dissipating sheet according to the embodiment of the present invention mixes each material in the following order.
Flame retardant functional materials, namely soluble flame retardants, solid flame retardants and heat conductive fillers, are added to the low viscosity diluent. The flame-retardant functional material is added to the diluent little by little.
Next, the diluent to which the flame-retardant functional material is added is added to the heat-resistant pressure-sensitive adhesive which is a high-viscosity main agent. For this reason, it is not necessary to add a large amount of powder (solid flame retardant or heat conductive filler) to the heat-resistant adhesive, which is a highly viscous liquid. Therefore, the powder should be added in a state where the surface tension of the heat-resistant adhesive is relaxed. And the adhesive strength does not decrease.

Ethyl acetate as a diluent, a solid flame retardant, and a heat conductive filler are placed in a polycup and stirred at a rotation speed of 500 rpm for 5 minutes.
After that, an acrylic resin-based heat-resistant adhesive and a soluble flame retardant, which are the main agents, are added, and the mixture is stirred at a rotation speed of 500 rpm for 5 minutes.
After that, a curing agent is added and the mixture is stirred at a rotation speed of 500 rpm for 5 minutes.
As an example, 34.5 g of ethyl acetate, 16.9 g of solid flame retardant, 0.9 g of heat conductive filler, 40.4 g of heat-resistant adhesive, 6.9 g of soluble flame retardant, and 0. Weigh 4g.

(4) Flame Retardant for Flame Retardant Functional Material As the flame retardant constituting the flame retardant functional material, a powder type solid flame retardant and a liquid type soluble flame retardant were used in combination.
If only a large amount of solid flame retardant is used as the flame retardant, the heat-resistant adhesive added because the solid flame retardant is a powder type becomes dry and dry, and as a result, the adhesive strength is reduced. .. Therefore, not only the solid flame retardant but also the liquid type soluble flame retardant having high adhesive strength is used in combination to secure the adhesive strength.

The flame-retardant heat-dissipating sheet constructed in this way was subjected to a flame-retardant test based on the UL94V test, and its flame retardancy was confirmed.
As a comparative example, a sheet in which the addition amounts of the solid flame retardant and the soluble flame retardant were 10%, 20%, and 30% was given.
The results are shown in Table 3 below. It was confirmed that only those in which the amount of the solid flame retardant and the soluble flame retardant added was 36.3% had flame retardancy.

In addition to the above-mentioned solid flame retardant and soluble flame retardant, the heat conductive pressure-sensitive adhesive is mixed with a heat conductive filler.
The heat conductive pressure-sensitive adhesive layer composed of the heat conductive pressure-sensitive adhesive has poor thermal conductivity because it uses a heat-resistant pressure-sensitive adhesive which is an acrylic resin as a main component.
Therefore, a heat conductive filler is mixed with the heat conductive pressure-sensitive adhesive to increase the heat conductivity and improve the heat dissipation effect.
Using a flame-retardant heat-dissipating sheet using the heat-conducting adhesive mixed with this heat-conducting filler as a heat-conducting adhesive layer, and a comparison sheet using a comparison adhesive not mixed with the heat-conducting filler, the following is used. Experiments were conducted and the heat dissipation effect was confirmed for each.

Cut a copper foil into 40 mm x 40 mm, attach a resistor with a resistance value of 1 Ω as a heating element to one side of it using each heat conductive adhesive, and apply a voltage of 1.5 V to this resistor for 30 minutes. The temperature of the resistor at the elapsed time was measured.
The experiment was carried out with the entire laboratory equipment covered with a windshield.
The experimental results are shown in Table 4 below.

From Table 4 above, it can be confirmed that the heat-dissipating effect of the flame-retardant heat-dissipating sheet 1000 in which the heat-conducting adhesive mixed with the heat-conducting filler is used as the heat-conducting adhesive layer 300 can be confirmed.

In the flame-retardant heat radiating sheet 1000, the heat radiating layer 200 has an insulating property, but the heat conductive diffusion layer 100 and the heat conductive adhesive layer 300 do not have an insulating property. Therefore, when the flame-retardant heat-dissipating sheet 1000 as a whole needs to have an insulating property, it is necessary to secure the insulating property by an appropriate method such as pouch processing.

100 Heat-conducting diffusion layer 200 Heat-dissipating layer 300 Heat-conducting adhesive layer 1000 Flame-retardant heat-dissipating sheet

Claims (9)

A heat conductive diffusion layer, a heat radiating layer laminated on one surface of the heat conductive diffusion layer, and a heat conductive adhesive layer laminated on the other surface of the heat conductive diffusion layer are provided, and the heat conductive diffusion layer is provided. It is a copper foil, the heat radiating layer is a flame-retardant heat-dissipating paint, the heat conductive adhesive layer is a mixture of a heat-resistant adhesive and a flame-retardant functional material, and the flame-retardant functional material is a solid flame-retardant. , A flame-retardant heat-dissipating sheet comprising a soluble flame-retardant and a heat-conducting filler. The flame retardant according to claim 1, wherein the heat radiating layer contains an acrylic urethane resin as a main component, and is a mixture of a heat radiating material, a dispersant, a precipitation inhibitor, a diluting solvent, a solid flame retardant, and a curing agent. Heat dissipation sheet. The flame-retardant heat-dissipating sheet according to claim 2, wherein the acrylic urethane resin is transparent. The flame-retardant heat-dissipating sheet according to claim 2 or 3, wherein the curing agent is transparent. The acrylic urethane resin is 10 to 40% (preferably 32.8%), the heat radiating material is 0.5 to 45% (desirably 11.3%), and the dispersant is 0.2 to 1.5% (desirably 11.3%). Desirably 0.5%), the anti-precipitation agent 0.2-1.5% (desirably 0.5%), the dilute solvent 5-45% (desirably 5.0%), the solid difficulty. The flame retardant according to claim 2, 3 or 4, wherein the fuel agent is 15 to 50% (preferably 28.5%), and the curing agent is 5 to 30% (desirably 21.4%). Heat dissipation sheet. The flame retardant heat dissipation according to claim 1, 2, 3, 4 or 5, wherein the solid flame retardant is 30% or more and 50% or less when the flame retardant heat dissipation paint is 100%. Sheet. Among the flame-retardant functional materials, the solid flame retardant and the heat conductive filler have a diameter smaller than the thickness dimension of the heat conductive adhesive layer according to claim 1, 2, 3, 4, 5 or The flame-retardant heat-dissipating sheet according to 6. The flame-retardant heat-dissipating sheet according to claim 2, 3, 4, 5, 6 or 7, wherein the heat-dissipating material is earth-like graphite having an average particle size of 5 μm. The flame-retardant heat-dissipating sheet according to claim 1, 2, 3, 4, 5, 6, 7 or 8, wherein a release paper is laminated on the heat-conducting adhesive layer.

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