CN219279780U - Composite insulating film for PTC with polyimide film as carrier - Google Patents

Abstract

The utility model discloses a composite insulating film for PTC taking a polyimide film as a carrier, which relates to the field of heat conduction insulating films, and has the technical scheme that: the heat conducting adhesive comprises a first release layer, a first heat conducting adhesive layer, a polyimide film layer, a second heat conducting adhesive layer and a second release layer which are sequentially arranged from top to bottom, wherein the D50 particle size of heat conducting powder of the first heat conducting adhesive layer is larger than that of heat conducting powder of the second heat conducting adhesive layer, the heat conductivity coefficient of the first heat conducting adhesive layer is 2.0W/m.K-9.0W/m.K, the heat conductivity coefficient of the second heat conducting adhesive layer is 0.5W/m.K-7.0W/m.K, the thickness of the first heat conducting adhesive layer is 0.25mm-0.7mm, and the thickness of the second heat conducting adhesive layer is 0.07mm-0.25mm. The utility model has the advantages of high heat conduction and low thermal resistance.

Description

Composite insulating film for PTC with polyimide film as carrier

Technical Field

The utility model relates to the field of heat conduction insulating films, in particular to a composite insulating film for PTC taking a polyimide film as a carrier.

Background

Positive temperature coefficient thermistor (PTC) ceramics are ferroelectric ceramics of a semiconducting nature that exhibit a stepwise increase in resistance above the curie temperature due to phase transitions. Due to such resistance-temperature characteristics, the material increases in resistance after temperature increases, and decreases in power; the resistance value is reduced after the temperature is reduced, and the power is increased, so that the effect similar to a thermostat can be generated. The conventional electrical heating assembly based on PTC ceramics is mostly formed by crimping or welding a PTC ceramic sheet covered with a planar electrode with a metal electrode sheet, and insulating the PTC ceramic sheet by wrapping a Polyimide (PI) insulating film. Polyimide films, although having good heat resistance and electrical insulation properties, have low thermal conductivity (< 0.8W/m·k), and thus have poor heat dissipation properties, which seriously hamper the derivation of the heat generation amount of PTC ceramics, and thus cause problems such as low thermal efficiency and reduced long-term use reliability.

In addition, the heat conducting strip that now commercially available also has bilayer structure's heat conducting strip, and this bilayer structure's heat conducting strip includes PI membrane and sets up the heat conduction glue film in PI membrane one side, and this type of heat conducting strip is in order to reach higher heat conduction effect, is filled with the heat conduction powder of great particle diameter and more quantity generally for the heat conducting strip bonding ability is relatively poor like this, and can not be comparatively inseparable laminating between PTC and heated object, and heat loss is great, and heat conductivility is not strong.

There is therefore a need to propose a new solution to this problem.

Disclosure of Invention

Aiming at the defects existing in the prior art, the utility model aims to provide the composite insulating film for the PTC, which takes the polyimide film as the carrier, and has the advantages of high heat conduction and low thermal resistance.

The technical aim of the utility model is realized by the following technical scheme: the composite insulating film for the PTC taking the polyimide film as the carrier comprises a first release layer, a first heat conducting adhesive layer, a polyimide film layer, a second heat conducting adhesive layer and a second release layer which are sequentially arranged from top to bottom, wherein the D50 particle size of heat conducting powder of the first heat conducting adhesive layer is larger than that of heat conducting powder of the second heat conducting adhesive layer, the heat conductivity coefficient of the first heat conducting adhesive layer is 2.0W/m.K-9.0W/m.K, the heat conductivity coefficient of the second heat conducting adhesive layer is 0.5W/m.K-7.0W/m.K, the thickness of the first heat conducting adhesive layer is 0.25mm-0.7mm, and the thickness of the second heat conducting adhesive layer is 0.07mm-0.25mm.

In one embodiment, the first and second layers of heat conductive adhesive each have a hardness of Shore0040-Shore0090.

In one embodiment, the D50 particle size of the heat conductive powder of the first heat conductive adhesive layer is less than or equal to 90 μm, and the D50 particle size of the heat conductive powder of the second heat conductive adhesive layer is less than or equal to 60 μm.

In one embodiment, a coupling agent layer is respectively arranged between the first heat conducting glue layer and the polyimide film layer and between the second heat conducting glue layer and the polyimide film layer.

In one embodiment, the coupling agent layer is a trimethoxyoctadecylsilane coupling agent layer.

In summary, the utility model has the following beneficial effects: when the PTC thermal insulation film is used, the first release layer and the second release layer are respectively torn off, the first thermal conductive adhesive layer is attached to the PTC, the second thermal conductive adhesive layer is attached to the target thermal body, the D50 particle size of the thermal conductive powder of the first thermal conductive adhesive layer is set to be larger than the D50 particle size of the thermal conductive powder of the second thermal conductive adhesive layer, a thermal conduction path is easier to form between the thermal conductive powder with large particle sizes, so that the first thermal conductive adhesive layer has better thermal conductivity, the heat of the PTC can be largely led out towards the direction of the target thermal body, the roughness of the thermal conductive powder with small particle size is relatively smaller, the contact area between the second thermal conductive adhesive layer and the target thermal body is larger, the attaching property is tighter, and the thermal interface resistance between the second thermal conductive adhesive layer and the target thermal body is favorably eliminated, so that the PTC thermal insulation film has the advantages of high thermal conductivity and low thermal resistance.

Drawings

Fig. 1 is a schematic structural view of a composite insulating film for PTC using a polyimide film as a carrier according to an embodiment of the present application.

In the figure: 1. a first release layer; 2. a first heat conducting adhesive layer; 3. a polyimide film layer; 4. a second heat conducting adhesive layer; 5. and a second release layer.

Detailed Description

The following description of the embodiments of the present utility model will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present utility model, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

As shown in fig. 1, an embodiment of the present application provides a composite insulating film for PTC using a polyimide film as a carrier, which includes a first release layer 1, a first heat conductive adhesive layer 2, a polyimide film layer 3, a second heat conductive adhesive layer 4 and a second release layer 5 that are sequentially set from top to bottom, where the D50 particle size of the heat conductive powder of the first heat conductive adhesive layer 2 is greater than the D50 particle size of the heat conductive powder of the second heat conductive adhesive layer 4.

The coefficient of thermal conductivity of the first thermal conductive adhesive layer 2 is 2.0W/m·k-9.0W/m·k, the coefficient of thermal conductivity of the second thermal conductive adhesive layer 4 is 0.5W/m·k-7.0W/m·k, the coefficient of thermal conductivity of the first thermal conductive adhesive layer 2 may be specifically 2.0W/m·k, 5.0W/m·k, 5.5W/m·k, 6W/m·k, 6.5W/m·k, 7W/m·k, 7.5W/m·k, 8.0W/m·k, 9.0W/m·k, the coefficient of thermal conductivity of the second thermal conductive adhesive layer 4 may be specifically 0.5W/m·k, 1W/m·k, 2.5W/m·k, 3W/m·k, 3.5W/m·k, 6W/m·k, 7.0W/m·k, the coefficient of thermal conductive adhesive layer 2 in this embodiment is preferably 6.5W/m·k, the coefficient of thermal conductive adhesive layer 2 is preferably 6.5W/m·k, the second thermal conductive adhesive layer 4 is preferably not the second thermal conductive adhesive layer is preferably the second thermal conductive adhesive layer 4, and the second thermal conductive adhesive layer is not preferably the second thermal adhesive layer is the thermal conductive adhesive layer is the thermal adhesive layer is the thermal adhesive layer is the adhesive layer, and the layer is the thermal adhesive layer.

The thickness of the first heat conducting glue layer 2 is 0.25mm-0.7mm, and the thickness of the second heat conducting glue layer 4 is 0.07mm-0.25mm.

Specifically, the thickness of the first heat conductive adhesive layer 2 may be 0.25mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, and the thickness of the second heat conductive adhesive layer 4 may be 0.07mm, 0.1mm, 0.15mm, 0.2mm, 0.25mm, and in this embodiment, it is preferable that the thickness of the first heat conductive adhesive layer 2 is 0.3mm, and the thickness of the second heat conductive adhesive layer 4 is 0.15mm.

When the composite insulating film for the PTC taking the polyimide film as the carrier is used, the first release layer 1 and the second release layer are respectively torn off, the first heat conducting adhesive layer 2 is attached to the PTC, the second heat conducting adhesive layer 4 is attached to the target heated body, the D50 particle size of the heat conducting powder of the first heat conducting adhesive layer 2 is set to be larger than the D50 particle size of the heat conducting powder of the second heat conducting adhesive layer 4, a heat conducting path is easier to form between the large-particle-size heat conducting powder, the first heat conducting adhesive layer 2 has better heat conductivity, the first heat conducting adhesive layer is connected with the PTC in a sleeving manner, the large-particle-size heat conducting powder is selected, the influence on the connection stability between the first heat conducting adhesive layer and the polyimide film layer is small, and therefore the heat of the PTC can be largely led out towards the direction of the target heated body, the roughness of the small-particle-size heat conducting powder is relatively small, so that the contact area between the second heat conducting adhesive layer 4 and the target heated body is larger, the adhesion is tighter, the interface thermal resistance between the second heat conducting adhesive layer 4 and the target heated body is favorable to be eliminated, and the PTC composite insulating film has the advantages of high heat conductivity and low heat conductivity.

In this embodiment, the hardness of the first heat conductive adhesive layer 2 and the second heat conductive adhesive layer 4 is Shore0055-Shore0065.

Specifically, the hardness of the first heat conductive adhesive layer 2 and the second heat conductive adhesive layer 4 may be Shore0050, shore0060, shore0090, and in this embodiment, the hardness of the first heat conductive adhesive layer 2 and the second heat conductive adhesive layer 4 is Shore0060, within this hardness, the hardness of the first heat conductive adhesive layer 2 and the second heat conductive adhesive layer 4 is moderate, and the adhesion and the supporting performance are better.

In this embodiment, the D50 particle size of the heat conductive powder of the first heat conductive adhesive layer 2 is less than or equal to 90 μm, and the D50 particle size of the heat conductive powder of the second heat conductive adhesive layer 4 is less than or equal to 60 μm.

It should be noted that, the first heat-conducting glue layer 2 and the second heat-conducting glue layer 4 are both heat-conducting silicone resin layers in the prior art, and the heat-conducting silicone resin layers are composed of heat-conducting silicone resin and heat-conducting powder mixed therein.

Specifically, the D50 particle size of the heat conductive powder of the first heat conductive adhesive layer 2 may be 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, or 90 μm, and the D50 particle size of the heat conductive powder of the second heat conductive adhesive layer 4 may be 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, or 60 μm, and in this embodiment, the D50 particle size of the heat conductive powder of the first heat conductive adhesive layer 2 is preferably 70 μm, and the D50 particle size of the heat conductive powder of the second heat conductive adhesive layer 4 is preferably 20 μm, so that the first heat conductive adhesive layer 2 has good adhesion performance and good adhesion performance while the second heat conductive adhesive layer 4 has good adhesion performance.

In this embodiment, coupling agent layers are respectively disposed between the first heat conductive adhesive layer 2 and the polyimide film layer 3, and between the second heat conductive adhesive layer 4 and the polyimide film layer 3.

Specifically, the coupling agent layer adopts the prior art, and is specifically a trimethoxyoctadecylsilane coupling agent layer.

Through the setting of coupling agent layer for can form chemical connection between first heat conduction glue film 2 and the polyimide rete 3, between second heat conduction glue film 4 and the polyimide rete 3, thereby can improve the stability of connection.

The above description is only a preferred embodiment of the present utility model, and the protection scope of the present utility model is not limited to the above examples, and all technical solutions belonging to the concept of the present utility model belong to the protection scope of the present utility model. It should be noted that modifications and adaptations to the present utility model may occur to one skilled in the art without departing from the principles of the present utility model and are intended to be within the scope of the present utility model.

Claims (5)

1. A composite insulating film for PTC using a polyimide film as a carrier, characterized in that: the heat conducting adhesive layer comprises a first release layer, a first heat conducting adhesive layer, a polyimide film layer, a second heat conducting adhesive layer and a second release layer which are sequentially arranged from top to bottom, wherein the D50 particle size of heat conducting powder of the first heat conducting adhesive layer is larger than that of heat conducting powder of the second heat conducting adhesive layer, the heat conductivity coefficient of the first heat conducting adhesive layer is 2.0W/m.K-9.0W/m.K, the heat conductivity coefficient of the second heat conducting adhesive layer is 0.5W/m.K-7.0W/m.K, the thickness of the first heat conducting adhesive layer is 0.25mm-0.7mm, and the thickness of the second heat conducting adhesive layer is 0.07mm-0.25mm.

2. The composite insulating film for PTC using a polyimide film as a carrier according to claim 1, wherein: the hardness of the first heat conducting glue layer and the second heat conducting glue layer is Shore0040-Shore0090.

3. The composite insulating film for PTC using a polyimide film as a carrier according to claim 1, wherein: the D50 particle size of the heat conducting powder of the first heat conducting adhesive layer is less than or equal to 90 mu m, and the D50 particle size of the heat conducting powder of the second heat conducting adhesive layer is less than or equal to 60 mu m.

4. The composite insulating film for PTC using a polyimide film as a carrier according to claim 1, wherein: and coupling agent layers are respectively arranged between the first heat conduction glue layer and the polyimide film layer and between the second heat conduction glue layer and the polyimide film layer.

5. The composite insulating film for PTC using a polyimide film as a carrier according to claim 4, wherein: the coupling agent layer is a trimethoxy octadecyl silane coupling agent layer.

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