A method for realizing electronic circuit preparation on the surface of PTFE

Abstract

The present application relates to a kind of methods for realizing electronic circuit preparation on PTFE surface, comprising the following steps: first, high-power laser is used to carry out etching roughening treatment to PTFE surface, then, using chemical etching treatment to improve its surface energy, then, using adhesive, and under vacuum hot pressing, copper foil is bonded together with PTFE substrate, and PTFE base copper-clad plate is prepared, then circuit board manufacturing process is used to prepare line part, finally, using laser etching to ablate the adhesive existing outside electronic circuit.The present application is more conducive to realize batch industrial production, and effectively improve the bonding strength between PTFE substrate and surface copper layer.

Description

Technical Field

[0001] This invention belongs to the technical field of combining laser surface etching, surface chemical reagent treatment and adhesive treatment, and specifically relates to a method for fabricating electronic circuits on a PTFE surface. Background Technology

[0002] Polytetrafluoroethylene (PTFE) is an ideal material for fabricating high-frequency electronic circuit boards due to its low dielectric constant, low dielectric loss, and low water absorption. In addition, it has good chemical corrosion resistance, aging resistance, lubricity, and radiation resistance, as well as excellent high and low temperature resistance, and can work for a long time in a temperature range of -250 to 260℃. As a result, electronic boards made of this material are widely used in many fields such as electronic engineering, aviation, aerospace, and automobile manufacturing.

[0003] However, since PTFE is a perfluorinated linear polymer compound formed by the covalent bonding of carbon and fluorine, it has extremely low surface energy and exhibits intrinsic superhydrophobic properties, making it difficult to wet and thus a non-stick material. Therefore, it is difficult to directly construct electronic circuits on the surface of PTFE films, which greatly limits its application in electronic devices.

[0004] Currently, numerous methods have been applied to the fabrication of electronic circuits on PTFE surfaces. For example, patent document CN106756902A discloses a method for metallizing the surface of polytetrafluoroethylene (PTFE) materials. This method involves first pre-depositing a layer of graphene oxide film on the PTFE surface, then covering it with a film containing metal elements, and finally achieving PTFE surface metallization through laser processing and chemical plating. This fabrication process has many advantages, such as being non-contact and low-pollution. However, the bonding strength between PTFE and the copper-plated layer only passed the test using 3M 610 adhesive tape, whose bonding strength is only 0.6 MPa. This relatively low bonding strength limits its application in industrial production, especially in mass production.

[0005] Patent document CN103540980A discloses a method for copper plating on the surface of polytetrafluoroethylene (PTFE) material. First, the PTFE surface is mechanically roughened by sandblasting. Then, a mixed solution of chromic anhydride and hydrofluoric acid is used for chemical roughening. Next, sensitization and activation treatments are performed. Finally, chemical copper plating is carried out. Although this invention can obtain a copper-plated metal layer on PTFE, it is difficult to fabricate electronic circuits because the chemical surface treatment lacks regional selectivity.

[0006] Patent document CN114025493A discloses a method for preparing a high-strength copper plating layer based on PTFE. This method first uses a high-energy-density ultraviolet laser to roughen the surface of PTFE. Then, a metal salt film is pre-placed on the roughened PTFE sheet surface. Next, infrared or visible light lasers are used at a lower laser energy density for full-scan processing. Finally, chemical plating is performed to prepare a high-strength copper plating layer on the PTFE surface. In this invention application, the bonding strength between PTFE and the surface copper plating layer can reach up to 6.81 MPa. Although this bonding strength is high, there is still a need for further improvement. Summary of the Invention

[0007] This invention addresses the technical problems existing in the prior art by providing a method for fabricating electronic circuits on the surface of PTFE, thereby solving at least one of the problems in the prior art, such as low bonding strength between PTFE and electronic circuits, difficulty in adapting to mass production, and low industrial application value.

[0008] The technical solution of the present invention to solve the above-mentioned technical problems is as follows:

[0009] A method for fabricating electronic circuits on a PTFE surface includes the following steps:

[0010] (1) Laser roughening treatment: The PTFE surface is roughened using a high-power laser;

[0011] (2) Chemical etching treatment: The surface of PTFE roughened in step (1) was chemically etched using a naphthalene-sodium treatment solution;

[0012] (3) Preparation of PTFE-based copper clad laminate: Using an adhesive, copper foil is bonded to the PTFE substrate in step (2) under vacuum hot pressing to prepare PTFE-based copper clad laminate;

[0013] (4) Preparation of PTFE-based circuit board: Using circuit board manufacturing process, PTFE substrate circuit is prepared on PTFE copper-clad board in step (3);

[0014] (5) Laser ablation of adhesive outside electronic circuits: Laser etching is used to ablate the excess adhesive outside the PTFE-based electronic circuit board in step (4).

[0015] Based on the above technical solution, the present invention can be further improved as follows.

[0016] Furthermore, the laser used in step (1) is an ultraviolet pulsed laser with a pulse width in the femtosecond or picosecond range. The pulsed laser power is 4 to 16W, the laser scanning rate is 300 to 1200 mm / s, the scanning interval is 8 to 30 μm, the laser pulse frequency is 100 kHz to 1 MHz, and the scanning method is grid scanning or parallel line scanning.

[0017] Furthermore, the sodium naphthalene treatment solution used in step (2) is prepared using tetrahydrofuran, refined naphthalene and metallic sodium as raw materials, and the concentration of the sodium naphthalene treatment solution is 0.50 to 2.0 mol / L.

[0018] Furthermore, the treatment time of the sodium naphthalene treatment solution in step (2) is 30 to 90 minutes.

[0019] Furthermore, the adhesive used in step (3) is an epoxy resin adhesive, and the raw materials of the epoxy resin adhesive include the following components by mass parts: 40 parts of E-51 epoxy resin, 60 parts of E-44 epoxy resin, 15-25 parts of polyethylene polyamine, 10-14 parts of No. 1 additive, 40-60 parts of No. 2 additive, and an appropriate amount of solvent.

[0020] Further, in step (3), after the epoxy resin adhesive raw materials are mixed, stirred and cured, the epoxy resin adhesive is evenly coated on the copper foil using a resin coating machine, and then stacked in the order of upper layer, middle layer and lower layer as copper foil layer, PTFE substrate and copper foil layer, and sent into a vacuum hot press for pressing.

[0021] Furthermore, in step (3), the hot pressing temperature of the vacuum hot press is 90-120℃, the relative pressure is 1.1-1.4 MPa, and the hot pressing time is 10-30 min.

[0022] Furthermore, the laser used in step (5) is an infrared pulsed laser with a pulse width on the order of nanoseconds. The pulsed laser power is 3 to 10W, the laser scanning rate is 500 to 1500 mm / s, the scanning distance is preferably 5 to 25 μm, and the laser pulse frequency is 50 kHz to 10 MHz.

[0023] Furthermore, the laser used in step (5) is a full-area scanning method.

[0024] The beneficial effects of this invention are:

[0025] (1) It is more conducive to mass industrial production. This invention does not require operation in a vacuum environment or in a chemical atmosphere. It is convenient and simple to operate and is more suitable for application in mass industrial production.

[0026] (2) Effectively improves the bonding strength between the PTFE substrate and the surface copper layer. This invention, through the combined application of laser surface etching technology and chemical etching modification technology, simultaneously modifies the surface roughness and surface energy of PTFE, effectively improving the bonding strength between the PTFE substrate and the surface copper layer. This is beneficial for the preparation of PTFE substrate electronic products with stable performance. Attached Figure Description

[0027] Figure 1 This is the PTFE surface structure after laser mesh scanning etching roughening in Embodiment 1 of the present invention.

[0028] Figure 2 This is a schematic diagram of the structure of the PTFE-based copper-clad laminate in Embodiment 1 of the present invention.

[0029] Figure 3 This is a schematic diagram of the determination of the bonding strength of the copper layer on the surface of a PTFE substrate using the solder welding vertical tensile method in Embodiment 1 of the present invention.

[0030] In the diagram: 1. PTFE substrate, 2. Adhesive, 3. Copper foil layer, 4. Tin-lead solder, 5. Force gauge. Detailed Implementation

[0031] The principles and features of the present invention are described below. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0032] Unless otherwise stated, the raw materials used in this invention are conventional materials in this technical field and are all commercially available. Unless otherwise specified, the test methods and detection methods in the following embodiments are conventional methods, and the equipment and instruments used in the tests are all commercially available. Parts not described in detail in this specification belong to the prior art.

[0033] The present invention discloses a method for fabricating electronic circuits on a PTFE surface, comprising the following steps:

[0034] (1) Laser roughening treatment: High-power laser is used to roughen the PTFE surface to improve its surface roughness.

[0035] The purpose of laser etching in step (1) is to roughen the PTFE surface. After laser treatment, the area will be covered with a large number of protrusions and pores composed of micron and nano-sized structures, which effectively improves the roughness of the PTFE surface.

[0036] The laser used in step (1) is preferably an ultraviolet (UV) laser. UV lasers have short wavelengths and high frequencies, resulting in high single-photon energy. During PTFE etching, they primarily function through photochemical reactions. This wavelength allows for the creation of richer micron- and nano-sized structures on the PTFE surface, which is beneficial for improving the bond strength between PTFE and the adhesive. In contrast, infrared and visible light lasers have longer wavelengths and lower frequencies, resulting in lower single-photon energy. These lasers exhibit greater thermal effects during PTFE etching, leading to fewer micron- and nano-sized structures on the PTFE surface and thus suboptimal bond strength between PTFE and the surface adhesive.

[0037] The laser used in step (1) is preferably a pulsed laser. Because PTFE has a high etching threshold, if a continuous laser is used, its low peak power results in poor etching and material reduction, making it difficult to obtain a rough surface on the PTFE surface. In contrast, pulsed lasers have high single-pulse peak power, resulting in better etching and material reduction. This allows for the construction of deep trenches on the PTFE surface, filled with numerous micron and nanometer-sized structures, which is beneficial for improving the bonding strength between PTFE and its surface adhesive.

[0038] The pulse width of the laser in step (1) is on the order of femtoseconds or picoseconds, and its corresponding peak power density is much higher than that of lasers with pulse widths on the order of nanoseconds and milliseconds. In addition, there is a certain degree of multiphoton absorption during the etching process, so the etching process of PTFE is mainly based on photochemical action, which can form richer micro- and nano-sized structures on the PTFE surface. This is beneficial to improving the surface roughness of PTFE after laser etching.

[0039] (2) Chemical etching treatment: The surface of the roughened PTFE in (1) was chemically etched using a naphthalene-sodium treatment solution to improve its surface energy.

[0040] In step (2), the high chemical reactivity of the sodium naphthalene treatment solution can be used to break the CF bonds in PTFE, causing some of the F atoms on its surface to detach. The remaining carbon atoms react with oxygen-containing substances in the solution to generate polar groups such as -OH, -COOH and -C=O on the surface of the PTFE substrate, thereby increasing its surface energy. This is beneficial for improving the bonding strength between the adhesive and PTFE.

[0041] (3) Preparation of PTFE-based copper clad laminate: Using an adhesive, copper foil is bonded to the PTFE substrate in step (2) under vacuum hot pressing to prepare PTFE-based copper clad laminate.

[0042] In step (3), vacuum hot pressing not only promotes the rapid curing of the epoxy resin adhesive, but also allows the adhesive to fully penetrate into the micron and nano-sized structures formed by laser roughening on the PTFE surface under pressure. This helps to form an interlocking mechanical structure between the PTFE and the adhesive at the interface, thereby improving the bonding strength between the adhesive and PTFE. Simultaneously, the vacuum hot pressing operation can also effectively enhance the bonding strength between the adhesive and the copper foil.

[0043] (4) Preparation of PTFE base circuit board: Using circuit board manufacturing process, PTFE base circuit board is prepared on PTFE copper clad board in step (3).

[0044] (5) Laser ablation of adhesive outside electronic circuits: Low-power laser etching is used to ablate the excess adhesive outside the PTFE-based electronic circuit board in step (4).

[0045] The laser used in step (5) is preferably an infrared pulsed laser, with a pulse width preferably in the nanosecond range. The pulsed laser power is preferably 3–10W, the laser scanning rate is preferably 500–1500 mm / s, the scanning spacing is preferably 5–25 μm, and the laser pulse frequency is preferably 50 kHz–10 MHz. This is because infrared lasers have a longer wavelength and lower frequency, resulting in lower single-photon energy. In addition, their pulse width is in the nanosecond range, leading to lower peak power. Under the combined effect of these two factors, laser etching can ablate and remove the adhesive outside the electronic circuitry when the pulsed laser power is 3–10W, the laser scanning rate is 500–1500 mm / s, the scanning spacing is 5–25 μm, and the laser pulse frequency is 50 kHz–10 MHz. However, because PTFE material has a high etching threshold, laser etching will not ablate the PTFE substrate under the adhesive.

[0046] In step (5), the preferred laser scanning method is full-area scanning. This is because, under the specified processing parameters, the laser etching peak power is lower than the etching threshold of PTFE material but higher than the etching threshold of adhesive material. Therefore, by using full-area scanning, precise processing positioning is not required, and the adhesive outside the electronic circuit can be ablated without damaging the PTFE substrate beneath the adhesive. In other words, the micron and nanostructures formed on the PTFE surface during the first high-power laser processing will not be damaged or affected. Thus, step (5) cleverly combines the high etching threshold of PTFE material with full-area scanning, eliminating the need for precise positioning in laser processing. This effectively improves processing efficiency, shortens processing time, and makes the processing more convenient.

[0047] The following are embodiments of the present invention.

[0048] Example 1

[0049] (1) Laser roughening treatment: The cleaned PTFE substrate is placed on the laser processing platform, and the PTFE substrate is fixed by the negative pressure adsorption device in the platform. The required processing pattern is imported into the computer using laser processing control software. A femtosecond pulsed laser with a wavelength of 355nm is used, with the laser output power set to 4W, the scanning speed to 300mm / s, the pulse frequency to 100KHz, and the laser scanning spacing to 8μm. The PTFE surface is roughened on the focal plane using a grid scanning method.

[0050] Figure 1 The image shows the PTFE surface after laser etching roughening treatment. As can be seen, under the action of laser grid scanning etching, the PTFE surface is covered with a micron-sized columnar protrusion array structure. At the same time, a large number of nano-sized pores and protrusions are also distributed on the surface of these columnar protrusion structures, which greatly improves the roughness of the PTFE surface. This is beneficial to improving its adhesion strength with adhesives.

[0051] (2) Chemical etching treatment: First, a sodium naphthalene treatment solution with a concentration of 0.50 mol / L was prepared using tetrahydrofuran, refined naphthalene and metallic sodium as raw materials. Then, the side of the PTFE substrate that was roughened by laser was placed in the sodium naphthalene treatment solution and chemically etched for 90 min.

[0052] (3) Preparation of PTFE-based copper clad laminate: Epoxy resin adhesive was used as the adhesive, and its raw materials included the following components by mass: 40 parts of E-51 epoxy resin, 60 parts of E-44 epoxy resin, 15 parts of polyethylene polyamine, 10 parts of dioctyl phthalate, 40 parts of 200-mesh quartz powder, and 50 parts of xylene. First, the raw materials of the epoxy resin adhesive were mixed, stirred, and cured. Then, the epoxy resin adhesive was uniformly coated onto the copper foil using a resin coating machine. Then, the layers were stacked in the following order: upper layer, middle layer, and lower layer, consisting of copper foil layer, PTFE substrate, and copper foil layer respectively. The layers were then placed in a vacuum hot press and hot-pressed for 30 minutes at 90°C (hot pressing temperature) and 1.4 MPa (relative pressure) to obtain the PTFE-based copper clad laminate.

[0053] Figure 2 This is a schematic diagram of the structure of the stacked PTFE-based copper-clad laminate.

[0054] (4) Preparation of PTFE-based circuit board: Using circuit board manufacturing process (such as thermal transfer PCB board manufacturing process), PTFE substrate electronic circuit is prepared on the PTFE copper-clad board in step (3).

[0055] (5) Laser ablation of epoxy resin adhesive outside electronic circuits: A 1064nm nanosecond pulsed laser is used. The laser output power is set to 3W, the scanning speed is 500mm / s, the pulse frequency is 50KHz, and the laser scanning distance is 5μm. Parallel line scanning is used to focus the laser on the epoxy resin adhesive outside the electronic circuits and process it. The purpose is to ablate the excess adhesive outside the PTFE-based electronic circuit board.

[0056] like Figure 3 As shown, the bonding strength of the copper layer on the surface of the PTFE substrate was measured using the solder welding vertical tensile method. The test results showed that the bonding strength of the copper layer on the surface was 6.05 MPa.

[0057] Example 2

[0058] (1) Laser roughening treatment: The clean PTFE substrate is placed on the laser processing platform, and the PTFE sheet is fixed by the negative pressure adsorption device in the platform. The required processing pattern is imported into the computer using laser processing control software. A picosecond pulsed laser with a wavelength of 355nm is used, with the laser output power set to 16W, the scanning speed to 1200mm / s, the pulse frequency to 1MHz, and the laser scanning spacing to 30μm. The PTFE surface is roughened on the focal plane using a grid scanning method.

[0059] (2) Chemical etching treatment: First, a sodium naphthalene treatment solution with a concentration of 2.0 mol / L was prepared using tetrahydrofuran, refined naphthalene and metallic sodium as raw materials. Then, the side of the PTFE substrate that was roughened by laser was placed in the sodium naphthalene treatment solution and chemically etched for 30 min.

[0060] (3) Preparation of PTFE-based copper clad laminate: Epoxy resin adhesive is used as the adhesive, and its raw materials include the following components by mass: 40 parts of E-51 epoxy resin, 60 parts of E-44 epoxy resin, 25 parts of polyethylene polyamine, 14 parts of dioctyl phthalate, 60 parts of 200-mesh quartz powder, and 100 parts of xylene. First, the raw materials of the epoxy resin adhesive are mixed, stirred, and cured. Then, the epoxy resin adhesive is uniformly coated onto the copper foil using a resin coating machine. Then, the layers are stacked in the following order: upper layer, middle layer, and lower layer, which are copper foil layer, PTFE substrate, and copper foil layer, respectively. The layers are then fed into a vacuum hot press and hot-pressed at 120°C and 1.1 MPa for 10 minutes to obtain the PTFE-based copper clad laminate.

[0061] (4) Preparation of PTFE-based circuit board: Using circuit board manufacturing process, PTFE substrate electronic circuit is prepared on PTFE copper-clad board in step (3).

[0062] (5) Laser ablation of epoxy resin adhesive outside electronic circuits: A 1064nm nanosecond pulsed laser is used. The laser output power is set to 10W, the scanning speed is 1500mm / s, the pulse frequency is 10MHz, and the laser scanning distance is 25μm. Parallel line scanning is used to focus the laser on the epoxy resin adhesive outside the electronic circuits for processing. The purpose is to ablate the excess adhesive outside the PTFE-based electronic circuit board.

[0063] Similarly, the bonding strength of the copper layer on the surface of the PTFE substrate was measured using the solder welding vertical tensile method. The test results showed that the bonding strength of the copper layer on the surface was 5.94 MPa.

[0064] Example 3

[0065] (1) Laser roughening treatment: The cleaned PTFE substrate is placed on the laser processing platform, and the PTFE sheet is fixed by the negative pressure adsorption device in the platform. The required processing pattern is imported into the computer using laser processing control software. A picosecond pulsed laser with a wavelength of 355nm is used, with the laser output power set to 10W, the scanning speed to 800mm / s, the pulse frequency to 200KHz, and the laser scanning spacing to 20μm. The PTFE surface is roughened on the focal plane using a grid scanning method.

[0066] (2) Chemical etching treatment: First, a sodium naphthalene treatment solution with a concentration of 1.0 mol / L was prepared using tetrahydrofuran, refined naphthalene and metallic sodium as raw materials. Then, after the PTFE substrate was roughened by laser, one side was placed in the sodium naphthalene treatment solution for chemical etching treatment for 45 min.

[0067] (3) Preparation of PTFE-based copper clad laminate: Epoxy resin adhesive was used as the adhesive, and its raw materials included the following components by mass: 40 parts of E-51 epoxy resin, 60 parts of E-44 epoxy resin, 18 parts of polyethylene polyamine, 12 parts of dioctyl phthalate, 45 parts of 200-mesh quartz sand, and 100 parts of xylene. First, the raw materials of the epoxy resin adhesive were mixed, stirred, and cured. Then, the epoxy resin adhesive was uniformly coated onto the copper foil using a resin coating machine. Then, the layers were stacked in the following order: upper layer, middle layer, and lower layer, consisting of copper foil layer, PTFE substrate, and copper foil layer respectively. The layers were then fed into a vacuum hot press and hot-pressed at 120°C and 1.2 MPa for 15 minutes to obtain the PTFE-based copper clad laminate.

[0068] (4) Preparation of PTFE-based circuit board: Using circuit board manufacturing process, PTFE substrate electronic circuit is prepared on PTFE copper-clad board in step (3).

[0069] (5) Laser ablation of resin outside electronic circuits: A 1064nm nanosecond pulsed laser is used. The laser output power is set to 8W, the scanning speed is 800mm / s, the pulse frequency is 400KHz, the laser scanning distance is 20μm, and the parallel line scanning method is adopted. The laser focus is focused on the epoxy resin glue part outside the electronic circuit to process it. The purpose is to ablate the excess adhesive outside the PTFE-based electronic circuit board.

[0070] Similarly, the bonding strength of the copper layer on the surface of the PTFE substrate was measured using the solder welding vertical tensile method. The test results showed that the bonding strength of the copper layer on the surface was 8.63 MPa.

[0071] By comparison, it can be seen that the bonding strength between the PTFE substrate and the surface copper layer in this invention can reach 8.63 MPa. This bonding strength is much higher than that in patent document CN106756902A. At the same time, compared with the bonding strength in patent document CN114025493A, this invention can increase the bonding strength between the PTFE substrate and the surface copper layer by more than 25.0%.

[0072] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for implementing electronic circuit fabrication on a PTFE surface, characterized by, The method comprises the following steps: (1) laser roughening treatment: high-power laser is used to roughen the surface of PTFE; (2) chemical etching treatment: naphthalene sodium treatment solution is used to etch the surface of PTFE after roughening in step (1); (3) preparation of PTFE-based copper-clad plate: an adhesive is used to bond copper foil and PTFE substrate in step (2) together under the action of vacuum hot pressing to prepare PTFE-based copper-clad plate; (4) preparation of PTFE-based circuit board: a circuit board manufacturing process is used to prepare PTFE-based circuit board on the PTFE-based copper-clad plate in step (3); (5) laser ablation of adhesive outside the electronic circuit: laser etching is used to ablate the excess adhesive outside the PTFE-based electronic circuit board in step (4); In step (2), the naphthalene sodium treatment solution is prepared from tetrahydrofuran, refined naphthalene and sodium metal, and the concentration of the naphthalene sodium treatment solution is 0.50-2.0 mol / L; In step (3), the adhesive is epoxy resin adhesive, and the raw materials of the epoxy resin adhesive include the following components by mass fraction: E-51 epoxy resin 40 parts, E-44 epoxy resin 60 parts, polyethylene polyamine 15-25 parts, 1# additive 10-14 parts, 2# additive 40-60 parts, and solvent in an appropriate amount; In step (1), the laser is ultraviolet band pulsed laser, the pulse width is femtosecond or picosecond order, the pulsed laser power is 4-16 W, the laser scanning rate is 300-1200 mm / s, the scanning interval is 8-30 μm, the laser pulse frequency is 100 KHz-1 MHz, and the scanning mode is grid scanning or parallel line scanning; In step (5), the laser is infrared band pulsed laser, the pulse width is nanosecond order, the pulsed laser power is 3-10 W, the laser scanning rate is 500-1500 mm / s, the scanning interval is 5-25 μm, and the laser pulse frequency is 50 KHz-10 MHz; In step (5), the scanning mode of the laser is full-area scanning mode, under the above processing parameters, the laser etching peak power is lower than the etching threshold of PTFE material but higher than the etching threshold of the adhesive material; by using full-area scanning, the adhesive outside the electronic circuit can be ablated without precise processing positioning, and the PTFE substrate under the adhesive will not be damaged, i.e., the micron structure and nanometer structure formed on the PTFE surface in the first high-power laser processing process will not be destroyed and affected.

2. The method for realizing electronic circuit preparation on the surface of PTFE according to claim 1, characterized in that, In step (2), the treatment time of the naphthalene sodium treatment solution is 30-90 min.

3. The method of claim 1, wherein the PTFE surface is a surface of a PTFE film. In step (3), after the raw materials of the epoxy resin adhesive are mixed, stirred and aged, the epoxy resin adhesive is uniformly coated on the copper foil by using a resin coating machine, and then the copper foil layer, the PTFE substrate and the copper foil layer are sequentially stacked in the order of upper layer, middle layer and lower layer, and then the stack is sent into a vacuum hot press for pressing.

4. The method for realizing electronic circuit preparation on the surface of PTFE according to claim 3, characterized in that, In step (3), the hot pressing temperature of the vacuum hot press is 90-120℃, the relative pressure is 1.1-1.4 MPa, and the hot pressing time is 10-30 min.

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