PDS antenna manufacturing method and electronic equipment

Abstract

The invention discloses a PDS antenna manufacturing method and electronic equipment, and the manufacturing method comprises the steps: groove manufacturing: manufacturing a groove in a stainless steel surface, and enabling the groove to extend to the junction of the stainless steel surface and a plastic surface; film layer manufacturing, wherein a composite film layer comprising a nickel layer and a silver layer or a composite film layer comprising a nickel layer and a gold layer is formed in the area, located in the groove, of the stainless steel surface, and the surface of the composite film layer is lower than the plastic surface; tinning: manufacturing a tin welding layer on the surface of the composite film layer, wherein the tin welding layer is basically flush with the plastic surface; and silver paste printing: printing silver paste patterns on the surface of the tin welding layer and the surface of the plastic, and curing to obtain the PDS antenna. The PDS antenna manufactured by the invention has better binding force with the composite film layer through the tin welding layer, so that the binding force between the PDS antenna and the stainless steel surface is indirectly improved.

Description

Technical Field

[0001] This application relates to the technical field of antennas, and specifically relates to a manufacturing method of a PDS antenna and an electronic device. Background Art

[0002] In the field of electronic device manufacturing, as an important component for signal reception and transmission, the performance of an antenna is crucial for the communication quality of the device.

[0003] With the development of electronic devices towards miniaturization and high performance, injection molded parts made of stainless steel and plastic are increasingly used. Compared with pure plastic casings, they have excellent high-temperature resistance and dimensional stability. However, when performing a direct silver paste printing process (Printing Direct Structure, PDS) on the surface of stainless steel, there will be a problem of poor adhesion strength between the silver paste and the stainless steel. Therefore, it is urgent to develop a new manufacturing method for PDS antennas. Summary of the Invention

[0004] Aiming at the above technical problems, this application provides a manufacturing method of a PDS antenna and an electronic device, which can improve the problem of poor adhesion strength between the silver paste and stainless steel of the PDS antenna manufactured by the existing method.

[0005] To solve the above technical problems, in a first aspect, an embodiment of this application provides a manufacturing method of a PDS antenna. The carrier of the PDS antenna includes a stainless steel surface and a plastic surface. The manufacturing method includes: Groove manufacturing: manufacturing a groove on the stainless steel surface, and the groove extends to the junction of the stainless steel surface and the plastic surface; Film layer manufacturing: forming a composite film layer including a nickel layer and a silver layer, or a composite film layer including a nickel layer and a gold layer, on the area of the stainless steel surface located in the groove, and the surface of the composite film layer is lower than the plastic surface; Tinning: manufacturing a tin soldering layer on the surface of the composite film layer, and the tin soldering layer is basically flush with the plastic surface; Silver paste printing: printing a silver paste pattern on the surface of the tin soldering layer and the plastic surface, and curing to obtain the PDS antenna.

[0006] Optionally, the step of film layer manufacturing includes: Providing a stainless steel sheet; Forming the composite film layer on the surface of the stainless steel sheet; Welding the side of the stainless steel sheet facing away from the composite film layer into the groove.

[0007] Optionally, the step of tinning includes: Coating a tin layer on the surface of the composite film layer; Hot press the tin layer under the conditions of 145~185°C and a pressure of 5~10 N / mm 2 to obtain the tin soldering layer.

[0008] Optionally, in the step of silver paste printing, PDS silver paste with a first viscosity is used; After the step of tin plating, it further includes: Ink filling: Set PDS silver paste with a second viscosity at the junction between the tin soldering layer and the plastic, wherein the second viscosity is less than the first viscosity.

[0009] Optionally, the first viscosity is 4-6 Pa·s, and the second viscosity is 2-3 Pa·s.

[0010] Optionally, the composite film layer further includes: a chromium layer formed on the surface of the groove.

[0011] Optionally, the thickness of the chromium layer is 0.1~0.3 μm; and / or, the thickness of the nickel layer is 2~4 μm; and / or, the thickness of the silver layer is 1~3 μm; and / or, the thickness of the gold layer can be 0.2~0.5 μm.

[0012] Optionally, the plastic is polyphenylene sulfide; Before the step of tin plating, it further includes: Surface etching: Laser etch the surface of the plastic to make the surface roughness of the plastic Ra 0.5~1.2 μm.

[0013] Optionally, the wavelength of the laser is 355 nm, the power is 5~15 W, the frequency is 20~50 kHz, and the scanning speed is 50~200 mm / s.

[0014] In a second aspect, the present application further provides an electronic device, including a housing and a PDS antenna. The inner surface of the housing includes a stainless steel surface and a plastic surface. The PDS antenna is formed on the stainless steel surface and the plastic surface and is formed by using the manufacturing method described in each of the above embodiments.

[0015] As described above, in the manufacturing method of the PDS antenna of the present application, a composite film layer is formed on the stainless steel surface. Among them, the nickel layer has a good bonding force with the stainless steel and provides a more active surface for the silver layer or the gold layer. The silver layer or the gold layer can provide a soldering base surface for the tin soldering layer to improve the adhesion of the solder. Finally, print the silver paste pattern (i.e., the PDS antenna pattern) and cure it to complete the production of the PDS antenna. The PDS antenna has a better bonding force with the composite film layer through the tin soldering layer, thereby indirectly improving the bonding force between the PDS antenna and the stainless steel surface. Brief Description of the Drawings

[0016] The drawings herein are incorporated into and constitute a part of this specification, showing embodiments consistent with the present application, and are used together with the specification to explain the principles of the present application. To more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, for those of ordinary skill in the art, without creative effort, other drawings can also be obtained based on these drawings.

[0017] Figure 1 is a schematic flowchart of a method for manufacturing a PDS antenna provided by an embodiment of the present application; Figure 2 is a schematic partial cross-sectional view of a housing provided by an embodiment of the present application; Figure 3 is a schematic view after making a groove in the housing; Figure 4 is a schematic view after making a composite film layer on the housing; Figure 5 is a schematic view after making a tin welding layer on the housing; Figure 6 is a schematic view after printing a silver paste pattern on the housing; Figure 7 is a schematic partial cross-sectional view of another housing after forming a PDS antenna provided by an embodiment of the present application; Figure 8 is a schematic view of the morphology of the PPS surface before and after etching in an embodiment of the present application, where (a) is before etching and (b) is the morphology after etching.

[0018] The realization of the purpose of the present application, functional features and advantages will be further described with reference to the embodiments and the drawings. Through the above drawings, the clear embodiments of the present application have been shown, and there will be more detailed descriptions hereinafter. These drawings and text descriptions are not intended to limit the scope of the concept of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. Detailed Embodiments

[0019] Exemplary embodiments will be described in detail herein, and the examples are shown in the drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. On the contrary, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0020] As described above, when manufacturing a PDS antenna on an injection-molded housing made of stainless steel and plastic, there will be a problem of poor adhesion strength between the silver paste and the stainless steel. Based on this, the present application provides a method for manufacturing a PDS antenna and an electronic device.

[0021] Please refer to Figure 1 , Figure 1 FIG. is a schematic flow chart of a method for manufacturing a PDS antenna provided by an embodiment of the present application. The carrier of the PDS antenna includes a stainless steel surface 10 and a plastic surface 20. The manufacturing method may include: S101, groove manufacturing: manufacturing a groove on the stainless steel surface, and the groove extends to the junction of the stainless steel surface and the plastic surface.

[0022] In this embodiment, the carrier of the PDS antenna, that is, the housing, is injection-molded from stainless steel and plastic. Exemplarily, the stainless steel may be 316L stainless steel, which has good corrosion resistance and mechanical properties. The plastic may be one or more composites of high molecular polymers such as PP (polypropylene), ABS (acrylonitrile-butadiene-styrene copolymer), PC (polycarbonate), and TPU (thermoplastic polyurethane). Preferably PPS (polyphenylene sulfide), and glass fiber may be added simultaneously, such as a glass fiber content of 40%. PPS is a thermoplastic engineering plastic with excellent mechanical strength, high temperature resistance, chemical resistance, and good thermal stability. The injection-molded parts of 316L stainless steel and PPS can form a housing with stable dimensions, good high temperature resistance, and corrosion resistance.

[0023] Please refer to Figure 2 and Figure 3 , Figure 2 FIG. is a partial cross-sectional view of a housing provided by an embodiment of the present application. Figure 3 FIG. is a schematic view after manufacturing a groove for the housing. Before manufacturing the groove 11, the stainless steel surface may be first cleaned. For example, plasma cleaning may be used to remove oil stains, foreign matters, etc. on the stainless steel surface. Then, the groove 11 is manufactured on the stainless steel surface 10, and the groove 11 extends to the junction of the stainless steel surface 10 and the plastic surface 20. Exemplarily, the groove 11 may be manufactured by CNC machining.

[0024] S102, film layer manufacturing: forming a composite film layer including a nickel layer and a silver layer, or a composite film layer of a nickel layer and a gold layer, on the area of the stainless steel surface located in the groove, and the surface of the composite film layer is lower than the plastic surface.

[0025] Please refer to Figure 4 , Figure 4Schematic diagram after making a composite film layer on the housing. Since the adhesion strength between the silver paste and the stainless steel is poor and the contact resistance between the silver paste and the stainless steel is too large, in this embodiment, a composite film layer 30 including a nickel layer 32 and a silver layer 33 can be formed first in the area of the stainless steel surface 10 located in the groove 11, and the surface of the composite film layer 30 is lower than the plastic surface 20. It should be noted that the silver layer 33 can be replaced by a gold layer.

[0026] The nickel layer 32, as an intermediate layer, can enhance the bonding force, prevent the diffusion of elements (such as Fe, Cr, etc.) in the stainless steel, improve the surface characteristics, and provide a more active surface for the subsequent formation of the silver layer 33 or the gold layer. The silver layer 33 or the gold layer can provide a welding base surface to improve the adhesion of the solder. Exemplarily, the nickel layer 32, the silver layer 33, and the gold layer can all be fabricated by physical vapor deposition (PVD) process.

[0027] Preferably, the composite film layer 30 can further include: a chromium layer 31 formed on the surface of the groove 11, that is, the chromium layer 31 is located below the nickel layer 32. The chromium layer 31 can enhance the corrosion resistance of the stainless steel surface 10, thereby improving the reliability of the housing.

[0028] As an example, the thickness of the chromium layer 31 can be 0.1 - 0.3 μm, the thickness of the nickel layer 32 can be 2 - 4 μm, the thickness of the silver layer 33 can be 1 - 3 μm, and the thickness of the gold layer can be 0.2 - 0.5 μm.

[0029] S103. Tin plating: Make a tin soldering layer on the surface of the composite film layer, and the tin soldering layer is substantially flush with the plastic surface.

[0030] Please refer to Figure 5 , Figure 5 Schematic diagram after making a tin soldering layer on the housing. A tin soldering layer 40 can be made on the surface of the composite film layer 30, and the tin soldering layer 40 is substantially flush with the plastic surface 20, that is, the tin soldering layer 40 fills the groove 11.

[0031] As an example of the tin plating step, tin plating can include: Coating a tin layer on the surface of the composite film layer 30. The tin layer is preferably low-temperature tin with a melting point of 135 - 145 °C, and further preferably a low-temperature tin wire with a melting point of 138 - 140 °C. The coating thickness of the tin layer can be 80 - 140 μm to ensure uniform coverage of the composite film layer 30.

[0032] Then, hot press the tin layer at 145 - 185 °C and a pressure of 5 - 10 N / mm2 to form a tin soldering layer 40, so that the tin soldering layer 40 forms a Sn - Ag (Sn - Au) alloy layer with the silver layer 33 (or the gold layer) to enhance the interface bonding force, and the tin soldering layer 40 is substantially flush with the plastic surface 20.

[0033] After the tin soldering layer 40 is completed, the surface of the tin soldering layer 40 can also be cleaned. As some examples, dry ice cleaning, alcohol ultrasonic cleaning, sodium hydroxide solution cleaning, etc. can be used for cleaning to remove the residual flux on the surface and ensure the cleanliness of the tin surface, such as a cleanliness ≥ 99.5%.

[0034] S104, silver paste printing: Print a silver paste pattern on the surface of the tin soldering layer and the plastic surface, and cure it to obtain the PDS antenna.

[0035] Please refer to Figure 6 , Figure 6 For the schematic diagram after printing the silver paste pattern on the housing, after the tin soldering layer 40 fills the groove 11, a silver paste pattern (i.e., the PDS antenna pattern) 50 can be printed on the surface of the tin soldering layer 40 and the plastic surface 20. That is, print the silver paste pattern 50 on the surface of the housing, and the silver paste pattern 50 straddles the tin soldering layer 40 (above the stainless steel surface 10) and the plastic surface 20, and then cure it to obtain the PDS antenna. Exemplarily, it can be baked at 150 °C for 1 h to completely cure the silver paste.

[0036] For the manufacturing method of the PDS antenna in this embodiment, a composite film layer 30 is formed on the stainless steel surface 10. Among them, the nickel layer 32 has a good bonding force with the stainless steel and provides a more active surface for the silver layer 33 or the gold layer. And the silver layer 33 or the gold layer can provide a soldering base surface for the tin soldering layer 40 to improve the adhesion of the solder. Finally, print the silver paste pattern (i.e., the PDS antenna pattern) 50 and cure it to complete the manufacturing of the PDS antenna. The PDS antenna has a better bonding force with the composite film layer 30 through the tin soldering layer 40, thereby indirectly improving the bonding force between the PDS antenna and the stainless steel surface 10. In addition, there is also a problem of excessive contact resistance between the PDS antenna manufactured by the traditional method and the stainless steel surface. This embodiment can also reduce the contact resistance between the two.

[0037] It should be noted that the composite film layer 30 can be directly formed in the groove 11 of the stainless steel by a coating method, but this method requires masking protection for other areas that do not need to be coated (such as coating a protective glue on the plastic surface 20 for protection), and it will waste coating materials and the cost is relatively high. Another method for forming the composite film layer 30 is provided in the embodiment of the present application. Please refer to Figure 7 , Figure 7 For the partial cross-sectional schematic diagram of another housing after forming the PDS antenna provided by the embodiment of the present application, this method can specifically include: Provide a stainless steel sheet 12, form a composite film layer 30 on the surface of the stainless steel sheet 12, and then weld the side of the stainless steel sheet 12 facing away from the composite film layer 30 to the groove 11, for example, by laser welding. The laser pulse width can be 50 - 100 ns, and the power can be 30 - 50 W. Exemplarily, the composite film layer 30 can be fabricated on a large-sized stainless steel sheet, and then the large-sized stainless steel sheet can be cut into stainless steel sheets 12 of the target size. Finally, laser welding is performed to weld the stainless steel sheet 12 in the groove 11, thereby achieving the purpose of forming the composite film layer 30 on the stainless steel surface 10.

[0038] In the process of forming the composite film layer 30 in this embodiment, no masking is required, the process is simple, and the utilization rate of the coating material is 100% except for normal process losses, which can reduce costs.

[0039] In one embodiment, in the step of silver paste printing, the PDS silver paste used has a first viscosity. After the tinning step, a supplementary ink step may further be included. For example, a PDS silver paste with a second viscosity can be set at the junction between the tin soldering layer 40 and the plastic by a dispensing device and pre-baked, for example, baked at 80 - 100 °C for 5 - 10 min. Among them, the second viscosity is less than the first viscosity. That is, the silver paste in the printing step uses a high-viscosity silver paste, and the supplementary ink step uses a low-viscosity silver paste. Since there are gaps at the interface between the tin soldering layer and the plastic, by setting a PDS silver paste with a second viscosity at the junction, the gaps can be better backfilled, thereby avoiding broken lines in the silver paste pattern at the gaps, and thus improving the production yield and reliability of the PDS antenna.

[0040] As an example, the viscosity of the high-viscosity silver paste can be 4 - 6 Pa·s, and the viscosity of the low-viscosity silver paste can be 2 - 3 Pa·s (at 25 °C, using a rotational viscometer LV-3, rotor No. 21, rotor speed of 10 rpm, tested after pre-shearing for 1 minute).

[0041] As an example of a low-viscosity silver paste, the solid particle size in the silver paste is ≤10 μm, the silver content is 85%, and the epoxy resin is 15%). The viscosity is 2 Pa・s. The gap is filled by a precision dispensing machine, and the filling height can be slightly higher than the plastic surface by 0.05 mm to ensure complete coverage of the gap.

[0042] In one embodiment, the plastic is polyphenylene sulfide (abbreviated as PPS, and 40% glass fiber can be added). Before the tinning step, a surface etching step may further be included: laser etching the plastic surface 20 to make the roughness of the plastic surface 20 be Ra0.5 - 1.2 μm. The silver paste preferably uses an epoxy system resin base, which can form a more stable bond with PPS.

[0043] PPS is a non-polar polymer with low surface energy and low roughness (Ra ≤ 0.2 μm). The main force between PPS and PDS silver paste is van der Waals force. The adhesion of the silver paste attached only by van der Waals force is insufficient (usually ≤ 2B in the cross-cut test) and cannot meet the requirements of high reliability. In this embodiment, to solve this problem, the surface of PPS can be modified by laser etching to increase the mechanical anchoring force of the silver paste on the PPS surface. In addition, during laser etching, the C-S-C bonds in the PPS molecular chain can be broken to generate polar functional groups such as C-O, C=O, and S-O, increasing the surface energy from about 35 mN / m to 55 - 65 mN / m and increasing the chemical bond binding sites with the silver paste, thereby improving the adhesion of the silver paste on the PPS surface. The principle is as follows: (1) The main chain of PPS breaks under the action of laser to generate free radicals.

[0044]

[0045] (2) The free radicals are oxidized in the air to generate polar oxygen-containing groups, such as sulfonic acid group (-SO3H), carboxyl group (-COOH), hydroxyl group (-OH), etc.

[0046]

[0047] (3) The interfacial reaction between the cured silver paste and the modified PPS, and its reaction principle can be one or more of the following various ways: A. Hydrogen bond binding

[0048] B. Sulfonic acid group and epoxy group

[0049] C. Carboxyl group and epoxy group

[0050] D. Hydroxyl group and epoxy group .

[0051] In one embodiment, the wavelength of the laser used for PPS surface etching is 355 nm, the power is 5 - 15 W, the frequency is 20 - 50 kHz, and the scanning speed is 50 - 200 mm / s. A three-dimensional microstructure with a roughness of Ra 0.5 - 1.2 μm can be formed on the PPS surface to improve the mechanical anchoring force.

[0052] The following further illustrates the present application with specific embodiments.

[0053] I. Sample preparation (1)Make grooves on the stainless-steel surface of the injection-molded part (the material is 316L stainless steel and PPS containing 40% glass fiber). The size of the grooves is 2*2*0.25 mm.

[0054] (2)Clean the surface of the injection-molded part using the plasma cleaning process.

[0055] (3)Deposit a nickel layer (thickness 3 μm) and a gold layer (thickness 0.3 μm) successively on a 316L stainless-steel sheet (thickness 0.06 mm) through physical vapor deposition, and cut out a 2*2 mm stainless-steel sheet.

[0056] (4)Weld the 2*2 mm stainless-steel sheet into the groove by laser welding (pulse width 75 ns, power 40 W) with the coated side facing up.

[0057] (5)Coat a tin layer with a thickness of approximately 80 μm on the surface of the groove to ensure uniform coverage of the underlying silver layer.

[0058] (6)Conduct hot pressing at 165 °C and 8 N / mm² to form a Sn-Ag alloy layer between the tin welding layer and the silver layer.

[0059] (7)Laser-etch the PPS surface using a pulsed ultraviolet laser. The laser wavelength is 355 nm, the power is 10 W, the frequency is 35 kHz, and the scanning speed is 100 mm / s. The surface morphology of the PPS before and after laser etching is as Figure 8 shown, where (a) is before etching and (b) is the morphology after etching. The roughness increases significantly after etching.

[0060] (8)Clean the surface of the entire substrate using sodium hydroxide solution.

[0061] (9)Apply silver paste (viscosity 2 Pa・s) at the junction of the tin welding layer and PPS, and pre-bake at 90 °C for 8 min to preliminarily cure the silver paste.

[0062] (10)Print PDS silver paste (epoxy system resin-based) on the surface of the tin welding layer and the PPS surface through pad printing. Control the silver paste film thickness to 12 μm, and bake at 150 °C for 1 h to completely cure the silver paste and form an antenna pattern.

[0063] II. Testing and Result Analysis (1)Adhesion strength test: Bond a PC rod to the 2×2 mm silver paste using 511 glue and conduct a vertical pull-off force test. The test value is 3.2 kgf, meeting the requirement of ≥2.5 kgf.

[0064] (2) Cross-cut test: For the PPS specimen without laser etching, silver paste was directly printed. The cross-cut test result was 2B (the standard for the shedding of the scribed squares, the larger the value, the better the adhesion), and the pull-off force was 0.6 kgf. The cross-cut test result of the sample in this example was 4B, and the pull-off force was 2.8 kgf, proving that the adhesion of the silver paste has been greatly improved.

[0065] (3) Gap (at the junction of PPS and the tin soldering layer) detection: Observed under a microscope, the result showed that the gap filling rate was 100%, and no silver paste wire breakage occurred after boiling in water.

[0066] (4) Dyn value (surface energy) detection: The Dyn value on the PPS surface increased from 32 to 34 dyn / cm, and the surface energy was significantly improved.

[0067] (5) Reliability test: The test conditions and results are shown in Table 1. Among them, "double 85" means storing at a temperature of 85°C ± 2°C and a humidity of 85% ± 3% for 168H; "high temperature" means storing at a temperature of 70°C ± 2°C for 168H; "low temperature" means storing at a temperature of -40°C ± 2°C for 168H; "temperature shock" means performing temperature conversion between -40 ± 2°C / 1H and 70 ± 2°C / 1H, with the conversion time less than 30S, and storing for 12 cycles.

[0068] Table 1 Contact resistance (mΩ) measured before and after the reliability experiment

[0069] The test results showed that for the sample without the composite film layer, the contact resistance fluctuated greatly, which was caused by poor adhesion. While for the sample in this example, the contact resistance was small and the value was stable, and after the reliability experiment, the contact resistance hardly changed.

[0070] This application also provides an electronic device, which includes a housing and a PDS antenna. The inner surface of the housing includes a stainless steel surface 10 and a plastic surface 20. The PDS antenna is formed on the stainless steel surface 10 and the plastic surface 20, and is formed by using the manufacturing method described in any of the above embodiments. As some examples, the electronic device can be a mobile phone, a tablet, etc.

[0071] For other manufacturing principles and processes of the electronic device in this example, refer to the description of the manufacturing method of the PDS antenna in the foregoing embodiments of the present invention, which will not be elaborated here.

[0072] It should be understood that the terms "comprising" and "including" indicate the presence of the stated features, steps, operations, elements, components, items, types, and / or groups, but do not exclude the presence, occurrence, or addition of one or more other features, steps, operations, elements, components, items, types, and / or groups. The terms "or", "and / or", "including at least one of the following", etc. used in this application can be interpreted inclusively, or mean any one or any combination. For example, "including at least one of the following: A, B, C" means "any one of the following: A; B; C; A and B; A and C; B and C; A and B and C", and again, "A, B or C" or "A, B and / or C" means "any one of the following: A; B; C; A and B; A and C; B and C; A and B and C". An exception to this definition occurs only when the combination of elements, functions, steps, or operations is inherently mutually exclusive in some way.

[0073] It should be understood that although the terms first, second, third, etc. may be used herein to describe various information, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from each other. For example, without departing from the scope of this application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, as used herein, the singular forms "a", "an", and "the" are intended to also include the plural forms, unless the context indicates otherwise.

[0074] It should be understood that the orientation or positional relationship indicated by the terms "top", "bottom", "upper", "lower", "vertical", "horizontal", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the device referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0075] The above are only the preferred embodiments of this application, and do not limit the patent scope of this application accordingly. The various technical features of the technical solution of this application can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the various technical features in the above embodiments are described. Any equivalent structural or equivalent process transformation made by using the content of the specification and drawings of this application, or directly or indirectly applied in other related technical fields, as long as the combination of these technical features does not conflict, is equally included in the patent protection scope of this application.

Claims

1. A manufacturing method of a PDS antenna, characterized in that The carrier of the PDS antenna includes a stainless steel surface and a plastic surface, and the manufacturing method includes: Groove manufacturing: manufacturing a groove on the stainless steel surface, and the groove extends to the junction of the stainless steel surface and the plastic surface; Film layer manufacturing: forming a composite film layer including a nickel layer and a silver layer, or a composite film layer of a nickel layer and a gold layer in the area of the stainless steel surface located in the groove, and the surface of the composite film layer is lower than the plastic surface; Tinning: manufacturing a tin soldering layer on the surface of the composite film layer, and the tin soldering layer is substantially flush with the plastic surface; Silver paste printing: printing a silver paste pattern on the surface of the tin soldering layer and the plastic surface, and curing to obtain the PDS antenna.

2. The manufacturing method according to claim 1, wherein The steps of the film layer manufacturing include: Providing a stainless steel sheet; Forming the composite film layer on the surface of the stainless steel sheet; Welding the side of the stainless steel sheet facing away from the composite film layer into the groove.

3. The manufacturing method according to claim 1, characterized in that, The steps of the tinning include: Coating a tin layer on the surface of the composite film layer; Hot press the tin layer under the conditions of 145~185°C and a pressure of 5~10 N / mm 2 to obtain the tin soldering layer.

4. The manufacturing method according to claim 1, wherein Using PDS silver paste with a first viscosity in the step of the silver paste printing; After the step of the tinning, it further includes: Ink filling: setting PDS silver paste with a second viscosity at the junction between the tin soldering layer and the plastic, wherein the second viscosity is less than the first viscosity.

5. The manufacturing method according to claim 4, wherein The first viscosity is 4 - 6 Pa·s, and the second viscosity is 2 - 3 Pa·s.

6. The manufacturing method according to claim 1, characterized in that, The composite film layer further includes: a chromium layer formed on the surface of the groove.

7. The manufacturing method according to claim 6, wherein The thickness of the chromium layer is 0.1 - 0.3 μm; and / or, The thickness of the nickel layer is 2 - 4 μm; and / or, The thickness of the silver layer is 1 - 3 μm; and / or, The thickness of the gold layer can be 0.2 - 0.5 μm.

8. The manufacturing method according to any one of claims 1-7, characterized in that, The plastic is polyphenylene sulfide; Before the step of the tinning, it further includes: Surface etching: performing laser etching on the plastic surface to make the roughness of the plastic surface be Ra 0.5 - 1.2 μm.

9. The manufacturing method according to claim 8, characterized in that, The wavelength of the laser is 355 nm, the power is 5 - 15 W, the frequency is 20 - 50 kHz, and the scanning speed is 50 - 200 mm / s.

10. An electronic device, characterized in that, Including a housing and a PDS antenna, the inner surface of the housing includes a stainless steel surface and a plastic surface, the PDS antenna is formed on the stainless steel surface and the plastic surface, and is formed by using the manufacturing method according to any one of claims 1 - 9.

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