Production method of high-frequency resin multilayer co-extrusion film substrate for satellite antenna

Abstract

The invention discloses a preparation method of a high-frequency resin multilayer co-extrusion film substrate for a satellite antenna. The preparation method comprises the following steps: S1, uniformly mixing polytetrafluoroethylene dispersion resin powder and an extrusion aid with a high-dielectric filler and a low-dielectric filler respectively to prepare a high-dielectric paste material and a low-dielectric paste material; s2, co-extruding the high-dielectric paste and the low-dielectric paste to obtain a three-layer composite sheet with a low-dielectric surface layer and a high-dielectric core layer; s3, calendering the three-layer composite sheet obtained in the step S2 to obtain a calendered sheet; and S4, heating the calendered sheet to obtain the high-frequency resin multi-layer co-extrusion film substrate for the satellite antenna. According to the production method of the high-frequency resin multi-layer co-extrusion film substrate for the satellite antenna, high-medium paste and low-medium paste are jointly extruded into a three-layer composite sheet from an extruder, and the technological process is remarkably shortened; the high-frequency resin multi-layer co-extrusion film substrate for the satellite antenna is prepared by calendering and heating the three layers of composite sheets, and the high-frequency resin multi-layer co-extrusion film substrate is not prone to layering and foaming after being heated.

Description

Technical Field

[0001] The invention relates to the technical field of copper clad laminates, and in particular to a method for producing a high-frequency resin multi-layer co-extruded film substrate for satellite antennas. Background Art

[0002] As electronic products are developing towards higher functionality and smaller size, circuit boards, as one of the core components of electronic products, are also developing towards thinner thickness, more layers, and higher density. In addition to the need to improve the substrate material and mechanical structure to achieve thinness, shortness, and lightness, the high-frequency parasitic effects unique to high-frequency circuits also need to be considered. Therefore, generally, substrates with low dielectric loss materials are used, high dielectric constant materials are used for power boards and ground boards, and / or low dielectric constant materials are used around signal lines to maintain signal transmission quality. Furthermore, multi-layer composite substrates and substrates made of high and low dielectric constant materials are used.

[0003] CN116494612A provides a method for preparing a polytetrafluoroethylene-based copper-clad laminate, comprising the following steps: preparing a PFA-based film; preparing a PTFE-based film, wherein the PTFE-based film is made of a mixed material of carbon black and PTFE; hot pressing the PFA-based film and the PTFE-based film to obtain a PFA-PTFE composite film, wherein the PTFE-based film is connected to a side of a mixed material of PFA and silicon dioxide in the PFA-based film; treating the surface of the silicon dioxide side in the PFA-PTFE composite film to make the surface of the silicon dioxide side porous; hot pressing a copper foil, a PFA-PTFE composite film, and a glass fiber board to obtain a polytetrafluoroethylene-based copper-clad laminate.

[0004] CN116494612A provides a method for hot pressing a PFA-based film and a PTFE-based film to obtain a composite film, i.e., a double-layer composite substrate. However, this method has more operating procedures when preparing a multi-layer composite substrate, and the layers are prone to stratification and bubbling after heating. Summary of the invention

[0005] One of the purposes of the present invention is to overcome the defects existing in the prior art and provide a method for producing a high-frequency resin multi-layer co-extruded film substrate for satellite antennas. The co-extruded film substrate is not easy to delaminate and bubble after being heated.

[0006] In order to achieve the above technical effects, the technical solution of the present invention is: a method for preparing a high-frequency resin multi-layer co-extruded film substrate for a satellite antenna, comprising the following steps:

[0007] S1: respectively mixing polytetrafluoroethylene dispersed resin powder and extrusion aid with high dielectric filler and low dielectric filler to prepare high dielectric paste and low dielectric paste;

[0008] S2: co-extruding the high dielectric paste and the low dielectric paste to obtain a three-layer composite sheet having a low dielectric surface layer and a high dielectric core layer;

[0009] S3: calendering the three-layer composite sheet obtained in S2 to obtain a calendered sheet;

[0010] S4: heating the calendered sheet to obtain a high-frequency resin multi-layer co-extruded film substrate for a satellite antenna.

[0011] Extrusion aids are also called lubricants. Their function is to increase the lubrication between polytetrafluoroethylene molecules and reduce the pushing resistance. Examples include solvent oil, petroleum ether, aviation kerosene, paraffin oil, ethylene dichloride, gasoline, I SOPAR series isoparaffin solvents, etc. The weight percentage of the extrusion aid is 20% to 50%.

[0012] A preferred technical solution is that the high dielectric filler is at least one selected from strontium titanate, barium titanate, lanthanum oxide, and bismuth selenate; and the low dielectric filler is silicon dioxide.

[0013] The preferred technical solution is that the mass ratio of polytetrafluoroethylene dispersed resin powder, extrusion aid and high dielectric filler in the high dielectric paste is 1:(1.88-3.13):(3-5); and / or the mass ratio of polytetrafluoroethylene dispersed resin powder, extrusion aid and low dielectric filler in the low dielectric paste is 1:(0.19-0.31):(0.19-0.31).

[0014] A preferred technical solution is that the number average molecular weight of the polytetrafluoroethylene dispersed resin powder in the high dielectric paste is 20 million to 30 million, and / or the number average molecular weight of the polytetrafluoroethylene dispersed resin powder in the high dielectric paste is 20 million to 30 million.

[0015] A preferred technical solution is that the average particle size of the high dielectric filler is 4 to 6 μm; and / or the average particle size of the silicon dioxide is 1.5 to 3.5 μm.

[0016] The preferred technical solution is that the co-extrusion die temperature of the high dielectric paste is 55-65°C, and the extrusion pressure is 18-22Mpa; the co-extrusion die temperature of the low dielectric paste is 55-65°C, and the extrusion pressure is 13-17Mpa. The co-extrusion die temperature of the high dielectric paste is, for example, 55°C, 57°C, 59°C, 61°C, 63°C, 65°C, or an interval value between any two of the above points; the co-extrusion die extrusion pressure of the high dielectric paste is, for example, 18Mpa, 20Mpa, 22Mpa, or an interval value between any two of the above points; the co-extrusion die temperature of the low dielectric paste is, for example, 55°C, 57°C, 59°C, 61°C, 63°C, 65°C, or an interval value between any two of the above points; the co-extrusion die extrusion pressure of the low dielectric paste is, for example, 13Mpa, 15Mpa, 17Mpa, or an interval value between any two of the above points. Preferably, the co-extrusion die temperature of the high dielectric paste is 60° C. and the extrusion pressure is 20 MPa; preferably, the co-extrusion die temperature of the low dielectric paste is 60° C. and the extrusion pressure is 15 MPa.

[0017] A preferred technical solution is that the thickness ratio of the low dielectric surface layer and the high dielectric core layer of the calendered sheet is 1:(4.13-6.88):1.

[0018] The preferred technical solution is that the calendering pressure of the three-layer composite sheet obtained by calendering S2 in S3 is 20-35Mpa, and the calendering temperature is 170-190°C. The calendering pressure in S3 is, for example, 20Mpa, 25Mpa, 30Mpa, 35Mpa point values ​​or interval values ​​between any two of the above point values, and the calendering temperature in S3 is, for example, 170°C, 172°C, 174°C, 176°C, 178°C, 180°C point values ​​or interval values ​​between any two of the above point values. Preferably, the calendering pressure in S3 is 25Mpa, and the calendering temperature is 180°C.

[0019] The preferred technical solution is that the heating in S4 is step-wise heating, and the specific process is as follows:

[0020] The calendered sheet is placed into the oven at a speed of 0.1-1 m / min, kept in a constant temperature zone of 120°C for 5 minutes, then enters a constant temperature zone of 180°C, kept in a constant temperature zone for 5 minutes, then enters a constant temperature zone of 280°C for 10 minutes.

[0021] The second object of the present invention is to provide a high-frequency resin multi-layer co-extruded film substrate for a satellite antenna, which is prepared by the above-mentioned production method of the high-frequency resin multi-layer co-extruded film substrate for a satellite antenna. The thickness of the high-frequency resin multi-layer co-extruded film substrate for a satellite antenna is 1 to 5 mm.

[0022] The advantages and beneficial effects of the present invention are:

[0023] The production method of the high-frequency resin multi-layer co-extruded film substrate for satellite antenna extrude high and low dielectric pastes from an extruder into a three-layer composite sheet, which significantly shortens the process flow;

[0024] The high-frequency resin multi-layer co-extruded film substrate for satellite antennas is obtained by calendering and heating the three-layer composite sheet, which is not easy to delaminate and bubble after being heated. DETAILED DESCRIPTION

[0025] The specific implementation of the present invention is further described below in conjunction with the examples. The following examples are only used to more clearly illustrate the technical solutions of the present invention, and cannot be used to limit the protection scope of the present invention.

[0026] PTFE resin powder, average particle size 450 μm, Daikin;

[0027] Extrusion aid: Isopar-M solvent oil, ExxonMobil;

[0028] Low dielectric filler: SiO2 powder, average particle size 2-3μm, China Ceramics;

[0029] High dielectric fillers: strontium titanate powder, average particle size 5μm, McLean; barium titanate powder, average particle size 5μm, McLean; lanthanum oxide powder, average 5μm, McLean; bismuth selenate powder, average particle size 5μm, Zhongnuo New Materials.

[0030] Example 1

[0031] S1, 200g of polytetrafluoroethylene resin powder, 200g of strontium titanate, barium titanate, lanthanum oxide, bismuth selenate mixed powder and 500g of extrusion aid are mixed to obtain a high dielectric paste; 800g of polytetrafluoroethylene resin powder, 200g of silicon dioxide powder and 200g of the auxiliary agent are fully mixed to obtain a low dielectric paste;

[0032] S2, high and low dielectric pastes are loaded into the extruder, and the co-extrusion die temperature of the high dielectric paste is set to 60°C, and the extrusion pressure is set to 20Mpa; the co-extrusion die temperature of the low dielectric paste is set to 60°C, and the extrusion pressure is set to 15Mpa; the sheet extruded by the extruder is a three-layer composite sheet, the middle layer corresponds to the high dielectric paste, and the surface layer corresponds to the low dielectric paste;

[0033] S3. The three-layer composite sheet is fed into a calender. The calendering pressure of the calender is set to 25 MPa and the temperature is set to 180°C. A 150 um calendered sheet is obtained. The thickness ratio of the low dielectric surface layer and the high dielectric core layer of the calendered sheet is 1:5.5:1.

[0034] S4. Place the calendered sheet into an oven at a speed of 1 m / min, keep it in a constant temperature zone of 120°C for 5 minutes, then enter the constant temperature zone of 180°C, keep it in a constant temperature zone of 280°C for 10 minutes, then cool it to room temperature to obtain a high-frequency resin multi-layer co-extruded film substrate for satellite antennas.

[0035] Example 2

[0036] Embodiment 2 is based on embodiment 1, and the difference is S1:

[0037] 800g of polytetrafluoroethylene resin powder, 200g of mixed powder of strontium titanate, barium titanate, lanthanum oxide, bismuth selenate and 200g of extrusion aid are mixed to obtain a high dielectric paste; 700g of polytetrafluoroethylene resin powder, 300g of silicon dioxide powder and 220g of the auxiliary agent are fully mixed to obtain a low dielectric paste.

[0038] Example 3

[0039] Embodiment 3 is based on embodiment 1, and the difference is S3:

[0040] The calendering pressure of the calendering machine was set to 40 MPa and the temperature was set to 180°C. A 150 um calendered sheet was obtained. The thickness ratio of the low dielectric surface layer and the high dielectric core layer of the calendered sheet was 1:5.5:1.

[0041] Example 4

[0042] Embodiment 4 is based on embodiment 1, and the difference is S4:

[0043] The calendered sheet is placed in an oven at a speed of 5m / min, kept in a constant temperature zone of 120°C for 5 minutes, then enters a constant temperature zone of 180°C, kept in a constant temperature zone of 280°C for 10 minutes, and then cooled to room temperature to obtain a high-frequency resin multilayer co-extruded film substrate for satellite antennas.

[0044] Comparative Example

[0045] Comparative Example 1 is based on Example 1, except that S2 and S3:

[0046] High and low dielectric pastes are loaded into the extruder, and the extrusion die temperature of the high dielectric paste is set to 60°C and the extrusion pressure is set to 20Mpa; the extrusion die temperature of the low dielectric paste is set to 60°C and the extrusion pressure is set to 15Mpa; the extruder extrudes high dielectric sheets and low dielectric sheets in sequence, and heats and calenders the high dielectric sheets and the low dielectric sheets under calendering pressure of 25Mpa and calendering temperature of 180°C, respectively, to obtain a low dielectric calendered sheet with a thickness of 20um and a high dielectric calendered sheet with a thickness of 110um, and then the 20um low dielectric calendered sheet is stacked on the upper and lower surfaces of the high dielectric calendered sheet and calendered, the calendering pressure is 25Mpa, and the calendering temperature is 180°C, to obtain a calendered sheet with a thickness of 150um.

[0047] Embodiment and comparative example performance test:

[0048] The dielectric constant, dielectric loss, thermal expansion coefficient, and heat resistance of the substrates prepared in the embodiments and comparative examples were tested according to the test standards IPC-TM-6502.5.5.5, IPC-TM-6502.1.24, and IPC-TM-650 2.4.13.1;

[0049] The performance test results of the examples and comparative examples are as follows:

[0050]

[0051] In Example 2, the ratio of polytetrafluoroethylene dispersed resin powder, extrusion aid and high dielectric filler in the high dielectric paste was changed, and the dielectric constant of the substrate was reduced; in Example 3, the calendering pressure of the calendering machine was increased, and the dielectric constant of the substrate was reduced; in Example 4, the speed of placing the calendered sheet into the oven was increased, and the dielectric constant of the substrate was reduced; in Comparative Example 1, high and low dielectric pastes were extruded separately and then compositely calendered, and the heat resistance was deteriorated.

[0052] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing a high-frequency resin multilayer co-extruded film substrate for a satellite antenna, characterized in that: The following steps are involved: S1: respectively mixing polytetrafluoroethylene dispersed resin powder and extrusion aid with high dielectric filler and low dielectric filler to prepare high dielectric paste and low dielectric paste; S2: co-extruding the high dielectric paste and the low dielectric paste to obtain a three-layer composite sheet having a low dielectric surface layer and a high dielectric core layer; S3: calendering the three-layer composite sheet obtained in S2 to obtain a calendered sheet; S4: heating the calendered sheet to obtain a high-frequency resin multi-layer co-extruded film substrate for a satellite antenna.

2. The method for producing a high-frequency resin multi-layer co-extruded film substrate for a satellite antenna according to claim 1, characterized in that: The high dielectric filler is at least one selected from strontium titanate, barium titanate, lanthanum oxide, and bismuth selenate; and the low dielectric filler is silicon dioxide.

3. The method for producing a high-frequency resin multi-layer co-extruded film substrate for a satellite antenna according to claim 1, characterized in that: The mass ratio of polytetrafluoroethylene dispersed resin powder, extrusion aid and high dielectric filler in the high dielectric paste is 1: (1.88-3.13): (3-5); and / or the mass ratio of polytetrafluoroethylene dispersed resin powder, extrusion aid and low dielectric filler in the low dielectric paste is 1: (0.19-0.31): (0.19-0.31).

4. The method for producing a high-frequency resin multi-layer co-extruded film substrate for a satellite antenna according to claim 1, characterized in that: The number average molecular weight of the polytetrafluoroethylene dispersed resin powder in the high dielectric paste is 20 million to 30 million; and / or the number average molecular weight of the polytetrafluoroethylene dispersed resin powder in the high dielectric paste is 20 million to 30 million.

5. The method for producing a high-frequency resin multi-layer co-extruded film substrate for a satellite antenna according to claim 1, characterized in that: The average particle size of the high dielectric filler is 4-6 μm; and / or the average particle size of the silicon dioxide is 1.5-3.5 μm.

6. The method for producing a high-frequency resin multi-layer co-extruded film substrate for a satellite antenna according to claim 1, characterized in that: The co-extrusion die temperature of the high dielectric paste is 55-65° C., and the extrusion pressure is 18-22 MPa; the co-extrusion die temperature of the low dielectric paste is 55-65° C., and the extrusion pressure is 13-17 MPa.

7. The method for producing a high-frequency resin multi-layer co-extruded film substrate for a satellite antenna according to claim 1, characterized in that: The thickness ratio of the low dielectric surface layer and the high dielectric core layer of the calendered sheet is 1:(4.13-6.88):

1.

8. The method for producing a high-frequency resin multi-layer co-extruded film substrate for a satellite antenna according to claim 1, characterized in that: The calendering pressure of the three-layer composite sheet obtained by calendering S2 in S3 is 20-35 MPa, and the calendering temperature is 170-190°C.

9. The method for producing a high-frequency resin multi-layer co-extruded film substrate for a satellite antenna according to claim 1, characterized in that: The heating in S4 is step-wise heating, and the specific process is as follows: The calendered sheet is placed into the oven at a speed of 0.1-1 m / min. After being kept in the 120°C constant temperature zone for 5 minutes, it enters the 180°C constant temperature zone. After being kept in the 180°C constant temperature zone for 5 minutes, it enters the 280°C constant temperature zone for 10 minutes.

10. A high-frequency resin multi-layer co-extruded film substrate for satellite antenna, characterized in that: The high-frequency resin multi-layer co-extruded film substrate for satellite antenna is produced by the production method of any one of claims 1 to 9, and the thickness of the high-frequency resin multi-layer co-extruded film substrate for satellite antenna is 1~5mm.

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