CN208241968U - A thermally conductive flexible circuit board - Google Patents

Abstract

The utility model relates to the technical field of heat-conducting products, and specifically to a heat-conducting flexible circuit board material, comprising a copper foil layer, a second heat-conducting silicone layer, a first glass fiber layer and a first heat-conducting silicone layer which are sequentially bonded, one side of the copper foil layer is a frosted surface, and the second heat-conducting silicone layer is attached to the frosted surface. One side of the copper foil layer is a frosted surface, and the second heat-conducting silicone layer is attached to the frosted surface of the copper foil layer. The frosted surface improves the bonding strength between the copper foil layer and the second heat-conducting silicone layer, so that the copper foil layer and the second heat-conducting silicone layer are tightly bonded, thereby improving the thermal conductivity; the first heat-conducting silicone layer and the second heat-conducting silicone layer have good thermal conductivity, and the first glass fiber layer improves the flexibility, tensile strength and insulation performance of the heat-conducting flexible circuit board material of the utility model.

Description

A thermally conductive flexible circuit board

technical field

The utility model relates to the technical field of heat-conducting supplies, in particular to a heat-conducting flexible circuit board.

Background technique

With the increasingly thinner and thinner trend of electrical products, the heat dissipation requirements for heating elements of circuit components are getting higher and higher, and most types of circuit components do not have the function of heat conduction at present.

In order to prevent the working temperature rise of power electronic devices from being too high, a heat-conducting substrate is usually added between the heat-generating device and the surface of the heat sink or metal shell. The flexible and elastic characteristics of the heat-conducting substrate can be used to cover very uneven surfaces. On the surface, the heat is conducted from the separation device or the entire circuit element to the metal shell or the diffusion plate, which can improve the efficiency and service life of the heating electronic components, but the copper-based and aluminum substrates with thermal conductivity cannot meet some complex requirements due to their rigidity. Occasions, such as: circular lamps need arc-shaped heat-conducting substrates for heat conduction.

In the invention patent with the application number 201210290596.4, a self-adhesive flexible thermally conductive substrate is disclosed. The performance is poor, and it is very easy to cause a short circuit, so an improvement scheme is urgently needed.

Utility model content

In order to overcome the shortcomings and deficiencies in the prior art, the purpose of the utility model is to provide a heat-conducting flexible circuit board, which improves the flexibility and insulation performance of the circuit board.

The purpose of the utility model is achieved through the following technical solutions: a heat-conducting flexible circuit board plate, including a copper foil layer, a second heat-conducting silica gel layer, a first glass fiber layer and a first heat-conducting silica gel layer laminated in sequence, the copper One side of the foil layer is a frosted surface, and the second heat-conducting silicone layer is attached to the frosted surface.

Preferably, the first thermally conductive silica gel layer is a thermally conductive silica gel layer doped with nano thermally conductive fillers and glass fiber filaments, and the glass fiber filaments are uniformly distributed in the thermally conductive silica gel layer.

Preferably, the glass fiber filaments have a length of 1-3mm and a diameter of 0.01-0.05mm.

Preferably, the thickness of the heat-conducting flexible circuit board is 0.1-0.4mm.

Preferably, a second glass fiber layer and a third heat-conducting silica gel layer are interposed between the first glass fiber layer and the first heat-conducting silica gel layer, and the second glass fiber layer is sandwiched between the first heat-conducting silica gel layer. Between the silica gel layer and the third heat-conducting silica gel layer, the third heat-conducting silica gel layer is sandwiched between the first glass fiber layer and the second glass fiber layer.

Preferably, the first glass fiber layer and the second glass fiber layer are glass fiber nets woven from glass fibers, and the aperture of the glass fiber nets is 1-2 mm; the second thermally conductive silica gel layer and the third The thermally conductive silica gel layers are all thermally conductive silica gel layers doped with nano thermally conductive fillers.

Preferably, the thickness of the heat-conducting flexible circuit board is 0.25-0.5mm.

Preferably, a release film is provided on the bottom of the first thermally conductive silica gel layer, and the release film is a fluoroplastic film.

Preferably, the surface roughness of the frosted surface is Ra: 1-10 μm.

Preferably, the thickness of the copper foil layer is 0.018-0.1mm; the thermal conductivity of the first thermally conductive silica gel layer is 1-4W/m·k, and the thickness of the first thermally conductive silica gel layer is 0.02-0.05mm.

The beneficial effect of the utility model is that: in the heat-conducting flexible circuit board material of the utility model, one side of the copper foil layer is a frosted surface, and a second heat-conducting silica gel layer is attached to the frosted surface of the copper foil layer. The bonding strength of the second thermally conductive silica gel layer makes the copper foil layer and the second thermally conductive silica gel layer closely bonded to improve thermal conductivity; the first thermally conductive silica gel layer and the second thermally conductive silica gel layer have good thermal conductivity, and the first glass fiber layer Improve the flexibility, tensile capacity and insulation performance of the heat-conducting flexible circuit board material of the utility model.

Description of drawings

Fig. 1 is the structural representation of the utility model embodiment 1;

Fig. 2 is a schematic structural view of Embodiment 2 of the utility model.

Reference signs are: 1. Copper foil layer; 2. First thermally conductive silica gel layer; 3. Release film; 4. Second thermally conductive silica gel layer; 5. First glass fiber layer; 6. Third thermally conductive silica gel layer; 7 , the second glass fiber layer.

Detailed ways

In order to facilitate the understanding of those skilled in the art, the utility model will be further described below in conjunction with the embodiments and accompanying drawings 1-2, and the content mentioned in the implementation mode is not a limitation of the utility model.

Example 1

As shown in Figure 1, a heat-conducting flexible circuit board material includes a copper foil layer 1, a second heat-conducting silica gel layer 4, a first glass fiber layer 5 and a first heat-conducting silica gel layer 2 laminated in sequence, and the copper foil layer One side of 1 is a frosted surface, and the second heat-conducting silica gel layer 4 is attached to the frosted surface.

In actual use, etch the circuit surface on the non-frosted side of the copper foil layer 1, remove the excess copper foil in the copper foil layer 1, and use the remaining copper foil as a circuit for soldering electronic components, and paste the first heat-conducting silicone layer 2 on one side. On the surface of the heat sink or metal shell, so that the heat of the circuit components can be transferred to the heat-conducting flexible circuit board in time, and then conducted from the heat-conducting flexible circuit board to the heat sink or metal shell for heat dissipation, prolonging the service life of the circuit components. One side of the copper foil layer 1 is a frosted surface, and the second thermally conductive silica gel layer 4 is attached to the frosted surface of the copper foil layer 1, and the bonding strength between the copper foil layer 1 and the second thermally conductive silica gel layer 4 is improved through the frosted surface, so that the copper foil Layer 1 and the second thermally conductive silica gel layer 4 are closely bonded to improve thermal conductivity; the first thermally conductive silica gel layer 2 and the second thermally conductive silica gel layer 4 have good thermal conductivity, and the first glass fiber layer 5 improves the thermal conductivity of the utility model. The flexibility, tensile capacity and insulation properties of the board.

In the process of pressing, because the first heat-conducting silica gel layer 2 and the second heat-conducting silica gel layer 4 have fluidity, the heat-conducting silica gel is filled into the gap of the glass fiber mesh, which can further enhance the tensile capacity of the utility model. At the same time, the first heat-conducting silica gel layer 2 and the second heat-conducting silica gel layer 4 are bonded together to improve the thermal conductivity of the first heat-conducting silica gel layer 2 and the second heat-conducting silica gel layer 4 . In the prior art, under the action of pressure, the copper foil passes through the heat-conducting silica gel, and the copper foil forms a path with the existing metal copper mesh, causing a short circuit and seriously affecting the service life of the circuit components. The first glass fiber layer 5 has strong tensile performance and good insulation performance, which avoids short circuit.

In this embodiment, the first thermally conductive silica gel layer 2 is a thermally conductive silica gel layer doped with nano thermally conductive fillers and glass fiber filaments, and the glass fiber filaments are evenly distributed in the thermally conductive silica gel layer. The nano thermal conductive filler is nano aluminum nitride and/or nano graphene. Preferably, the nano-thermally conductive filler is nano-aluminum nitride and nano-graphene, and the thermally-conductive silica gel doped with nano-aluminum nitride and nano-graphene greatly improves the thermal conductivity and insulation performance of the thermally-conductive silica gel. In other embodiments, the first thermally conductive silica gel layer 2 may be a thermally conductive silica gel layer doped with nano thermally conductive fillers, so as to prevent the glass fiber filaments from affecting the thermal conductivity of the thermally conductive silica gel.

The nano-graphene, nano-aluminum nitride and glass fiber filaments involved in this embodiment are all existing technologies, and are only used here.

In this embodiment, the glass fiber filaments have a length of 1-3mm and a diameter of 0.01-0.05mm. Preferably, the glass fiber filaments have a length of 2 mm and a diameter of 0.03 mm. The glass fiber filaments have good flexibility and insulation properties, have large elongation within the elastic limit and high tensile strength, and can absorb large impact energy. , can greatly improve the flexibility, tensile capacity and insulation performance of the circuit board.

In this embodiment, the thickness of the thermally conductive flexible circuit board is 0.1-0.4 mm. Preferably, the thickness of the heat-conducting flexible circuit board is 0.2mm, and the heat-conducting flexible circuit board is very thin, so as to avoid the problem of occupying a large space in small electronic products.

In this embodiment, a release film 3 is provided at the bottom of the first heat-conducting silica gel layer 2, and the release film 3 is a fluoroplastic film. The fluoroplastic film is pasted on the bottom of the first heat-conducting silica gel layer 2, the first purpose of which is to prevent dust and other impurities from adhering to the first heat-conducting silica gel layer 2 and increase the thermal resistance of the first heat-conducting silica gel layer 2, Thereby reducing the heat conduction effect of the first heat-conducting silica gel layer 2; the second is to avoid affecting the self-adhesiveness and sealing performance of the first heat-conducting silica gel layer 2, and affecting the fit between the first heat-conducting silica gel layer 2 and the heat sink or metal shell, and cannot Give full play to the heat conduction effect of the first heat-conducting silica gel layer 2; in actual use, tear off the fluoroplastic film attached to the first heat-conducting silica gel layer 2, and then paste the first heat-conducting silica gel layer 2 on the heat sink or A metal case will do.

In this embodiment, the surface roughness of the frosted surface is Ra: 1˜10 μm. Preferably, the surface roughness of the frosted surface is Ra: 5 μm, further improving the bonding strength between the copper foil layer 1 and the second thermally conductive silica gel layer 4, so that the copper foil layer 1 and the second thermally conductive silica gel layer 4 are more tightly bonded , thereby improving the thermal conductivity, and reducing the processing difficulty of the frosted surface.

In this implementation, the thickness of the copper foil layer 1 is 0.018-0.1mm; the thermal conductivity of the first thermally conductive silica gel layer 2 is 1-4W/m·k, and the thickness of the first thermally conductive silica gel layer 2 is 0.02-0.05mm. Preferably, the thickness of the copper foil layer 1 is 0.075mm; the thermal conductivity of the first thermally conductive silica gel layer 2 is 2W/m·k, and the thickness of the first thermally conductive silica gel layer 2 is 0.05mm.

Example 2

As shown in Figure 2, the difference between this embodiment and the above-mentioned embodiment 1 is:

A second glass fiber layer 7 and a third thermal silica gel layer 6 are interposed between the first glass fiber layer 5 and the first thermally conductive silica gel layer 2, and the second glass fiber layer 7 is sandwiched between the first thermally conductive silica gel layer 2. Between a heat-conducting silica gel layer 2 and a third heat-conducting silica gel layer 6 , the third heat-conducting silica gel layer 6 is sandwiched between the first glass fiber layer 5 and the second glass fiber layer 7 . The second glass fiber layer 7 further improves the flexibility, tensile and insulating properties of the circuit board sheet.

In this embodiment, the first glass fiber layer 5 and the second glass fiber layer 7 are both glass fiber meshes woven from glass fibers, which are prior art and are only used here. The aperture of the glass fiber mesh is 1-2mm; the second thermally conductive silica gel layer 4 and the third thermally conductive silica gel layer 6 are both thermally conductive silica gel layers doped with nano thermally conductive fillers. Preferably, the pore size of the glass fiber mesh is 1 mm.

In the process of pressing and pasting the circuit board, because the second thermally conductive silica gel layer 4 and the third thermally conductive silica gel layer 6 have fluidity, the thermally conductive silica gel of the second thermally conductive silica gel layer 4 and the third thermally conductive silica gel layer 6 is filled to the first In the gap of the glass fiber layer 5, the tensile performance of the circuit board can be further enhanced, and at the same time, the second thermally conductive silica gel layer 4 and the third thermally conductive silica gel layer 6 are bonded together to improve the performance of the second thermally conductive silica gel layer. The thermal conductivity of layer 4 and the third thermally conductive silica gel layer 6; similarly, during the pressing process of the second glass fiber layer 7, the thermally conductive silica gel of the third thermally conductive silica gel layer 6 and the first thermally conductive silica gel layer 2 is filled to the second In the gap of the glass fiber layer 7, the tensile performance of the circuit board is further enhanced, and at the same time, the third thermally conductive silica gel layer 6 and the first thermally conductive silica gel layer 2 are bonded together to improve the performance of the third thermally conductive silica gel layer. 6 and the thermal conductivity of the first thermally conductive silicone layer 2.

In this embodiment, the thickness of the heat-conducting flexible circuit board is 0.25-0.5 mm. Preferably, its thickness is 0.3mm.

The above-mentioned embodiment is a preferred implementation of the utility model. In addition, the utility model can also be realized in other ways. Any obvious replacement is within the scope of protection of the utility model without departing from the concept of the utility model. Inside.

Claims (10)

1. a kind of thermal conductivity flexible circuit board plate material, it is characterised in that: including be successively bonded copper foil layer, the second heat conduction silicone, First glass layer and the first heat conduction silicone, the one side of the copper foil layer are frosting, the second heat conduction silicone patch Invest the frosting；First glass layer be it is fiberglass braided made of glass fiber mesh；Described first is thermally conductive Layer of silica gel is the heat conduction silicone of dopen Nano heat filling and glass fiber；Second heat conduction silicone is dopen Nano The heat conduction silicone of heat filling.

2. a kind of thermal conductivity flexible circuit board plate material according to claim 1, it is characterised in that: first heat conduction silicone Glass fiber be uniformly distributed in first heat conduction silicone.

3. a kind of thermal conductivity flexible circuit board plate material according to claim 2, it is characterised in that: first heat conduction silicone Glass fiber length be 1-3mm, diameter 0.01-0.05mm.

4. a kind of thermal conductivity flexible circuit board plate material according to claim 1, it is characterised in that: the thermal conductivity flexible circuit board Material with a thickness of 0.1-0.4mm.

5. a kind of thermal conductivity flexible circuit board plate material according to claim 1, it is characterised in that: first glass layer The second glass layer and third heat conduction silicone, second glass fibre are folded between first heat conduction silicone Layer is located between first heat conduction silicone and third heat conduction silicone, and the third heat conduction silicone is located in described the Between one glass layer and the second glass layer.

6. a kind of thermal conductivity flexible circuit board plate material according to claim 5, it is characterised in that: second glass layer Be it is fiberglass braided made of glass fiber mesh, the aperture of second glass layer is 1-2mm；The third is thermally conductive Layer of silica gel is the heat conduction silicone of dopen Nano heat filling.

7. a kind of thermal conductivity flexible circuit board plate material according to claim 5, it is characterised in that: the thermal conductivity flexible circuit board Plate with a thickness of 0.25-0.5mm.

8. a kind of thermal conductivity flexible circuit board plate material according to claim 1, it is characterised in that: first heat conduction silicone Bottom be provided with release film, the release film is fluorine plastic film.

9. a kind of thermal conductivity flexible circuit board plate material according to claim 1, it is characterised in that: the surface of the frosting is thick Rugosity is Ra:1~10 μm.

10. a kind of thermal conductivity flexible circuit board plate material according to claim 1, it is characterised in that: the thickness of the copper foil layer For 0.018-0.1mm；First heat conduction silicone with a thickness of 0.02-0.05mm.