Method for preparing metal pattern through laser activation on 3D printing resin / ceramic surface

Abstract

The invention provides a method for preparing a metal pattern on the surface of 3D printing resin / ceramic through laser activation, which comprises the following steps: taking one or more of metal salt solutions as a carrier, immersing a 3D printing workpiece subjected to surface treatment in the metal salt carrier solution, and controlling a certain distance between the activated surface of a matrix and the liquid level; a metal salt solution is decomposed through a laser activation technology to generate activated seeds, the activated seeds are embedded into the surface of an activated base material, a metal particle / base material blend is formed, and finally a metal layer is selectively prepared in an activated area through a chemical plating method. A certain anchoring effect is generated between the metal layer and the dielectric layer due to the fact that the seed layer is embedded in the dielectric layer, and therefore the metal layer prepared through chemical plating has excellent binding force.

Description

Technical Field

[0001] The invention belongs to the field of laser technology, and in particular relates to a method for preparing metal patterns by laser activation on the surface of a 3D printing resin / ceramic. Background Art

[0002] Plastic engineering materials such as polyetheretherketone (PEEK), polyimide (PI) and polyphenylene sulfide (PPS) have broad application prospects in the electronics industry, aviation, aerospace and other industries, such as frequency-selective antenna covers, fairings and functional components, due to their excellent radiation resistance, high temperature resistance, mechanical properties, good chemical corrosion resistance and low dielectric properties.

[0003] At the same time, the 3D printing technology that has emerged in recent years can easily and quickly prepare various shapes of special-shaped weight-reducing structures, especially non-expanded curved structures such as honeycomb sandwich antenna covers. Its excellent mechanical temperature resistance and low dielectric properties provide a good carrier for communication products such as frequency-selective antennas and conformal antennas. It is worth paying attention to how to prepare a highly reliable and highly conductive continuous metal layer on the surface of 3D printing resins and ceramics to give the product electrical functional characteristics.

[0004] At present, the preparation of patterned metal layers on the surfaces of resins such as PEEK and ceramics is mainly carried out by evaporation / sputtering, chemical plating, and then mechanical processing or laser engraving to achieve patterning. The entire preparation process is relatively long and milling and laser metallization processing of thin shell surfaces is difficult (that is, conformal processing of curved surfaces is difficult), and it is also easy to produce burrs on the boundaries of metal graphics and transition etching of the substrate. Chinese patent application CN114134489A discloses a chemical plating method for metal layers on the surfaces of polyetheretherketone and modified polyetheretherketone, and Chinese patent application CN116641029A discloses a method for preparing titanium coatings by sputtering. Neither of these two technical solutions involves subsequent metal patterning processing methods.

[0005] Compared with the above methods, laser selective chemical plating technology can quickly realize the preparation of metal patterns through the combination of calibrated area activation and chemical plating, which is suitable for thin shell surfaces. Chinese patent application CN114786342A discloses a method for preparing flexible and bendable metal patterns by laser selective area activation combined with subsequent chemical plating technology after coating the surface of the substrate with a laser activated suspension solution and drying it. However, this method causes the surface roughness of the substrate to increase due to the direct action of the laser on the substrate, which causes the surface roughness of the metal layer after chemical plating to increase. The dried sensitizer suspension has a strong bonding force with some substrates, which is easy to be not cleaned cleanly, resulting in the risk of overflow plating, and the heat-affected zone of the laser action causes the edge of the chemically plated metal pattern to be rough. Chinese patent application CN114243303A discloses the use of spraying activator solution, and after drying, the non-graphic area is removed by laser processing, and the activator retained in the graphic area is used as a seed source for chemical plating to form a metal layer. Since the activator layer prepared by the spraying method is difficult to ensure the uniformity of the activator, it is difficult to remove it cleanly during the subsequent laser processing or it will damage the substrate. In addition, the temperature resistance of the activator used and the bonding strength with PEEK are difficult to ensure, so it is rarely used in engineering applications.

[0006] It can be seen that although processes such as evaporation, magnetron sputtering and chemical plating have solved the problem of preparing metal coatings, laser, milling and other subtractive processes are still needed to pattern the metal coatings. The entire preparation process is relatively long and conformal processing of curved surfaces is difficult. Although laser selective chemical plating technology can quickly prepare metal graphics, laser selective activation can easily cause the roughness of the substrate to increase (the existing technology uses femtosecond lasers to reduce thermal damage to the substrate and thus reduce the roughness, but femtosecond lasers are expensive), and the activation liquid that is not cleaned properly can easily cause the risk of overflow plating and the laser heat-affected zone causes rough edges of the chemically plated graphics, and the chemically plated seed layer formed on the substrate is of a single type.

[0007] In view of the above problems, the present invention considers it necessary to explore a method for preparing metal patterns by laser activation of 3D printing resin / ceramic surface. Summary of the invention

[0008] The purpose of the present invention is to solve the shortcomings of the prior art and provide a method for preparing metal patterns by laser activation on the surface of 3D printed resin / ceramic. The method can realize the rapid preparation of high-precision metallized patterns on the surface of 3D printed resin / ceramic and form different metal layer activation areas on the same substrate surface.

[0009] To achieve the above purpose, the technical solution provided by the present invention is:

[0010] A method for preparing metal patterns by laser activation of a 3D printing resin / ceramic surface, which is special in that it comprises the following steps:

[0011] S1. Surface preparation

[0012] The surface of the 3D printed workpiece made of resin or ceramic is mechanically polished (using sandpaper, grinder, polisher, etc.), and the holes exposed by the polishing are sealed with resin glue. After curing, mechanical polishing is performed again to ensure that the roughness of the workpiece surface is less than Ra0.3, and then ultrasonic cleaning is performed to ensure the surface smoothness to obtain a processed 3D printed workpiece;

[0013] The printed workpiece is subjected to surface pretreatment, mainly because the step lines of the printed workpiece will affect the roughness of the coating and the uniformity of laser activation, which may affect the bonding strength of the coating;

[0014] S2. Immersion

[0015] Immerse the 3D printed workpiece treated with S1 in the metal salt carrier solution, and control the distance between the activated surface of the workpiece and the liquid surface to be no more than 5 mm;

[0016] The metal salt carrier solution is a single-component metal salt carrier solution or a multi-component metal salt carrier solution (i.e., the solution includes at least two different components of metal salt carriers), and the prepared concentration is 0.1 to 50 g / L;

[0017] S3. Activation

[0018] After using the laser to control the focal length, the surface of the 3D printed workpiece under the liquid surface is scanned and activated according to the design pattern to form a chemical plating area on the surface of the 3D printed workpiece. The laser power is selected to be 0.03-10W, which is related to the immersion depth and the selected salt solution. It needs to be determined by experimental tests. The testing means are known to those skilled in the art. When selecting the metal salt carrier solution, it is only necessary to activate the metal layer of the seed to have a chemical bond with the subsequent chemically plated metal to ensure the normal growth of the subsequent chemically plated metal layer.

[0019] S4. Chemical Plating

[0020] After the 3D printed workpiece with the chemical plating area is taken out and cleaned, a metal seed layer is deposited on the surface of the workpiece by using a chemical plating process for general chemical plating treatment to complete the preparation of the metal pattern;

[0021] Among them, the 3D printed workpiece with the chemical plating area should be taken out and cleaned within 2 hours. Otherwise, too long a time will cause part of the metal salt solution to dry out (that is, the solution becomes a dry film through the evaporation of natural solvents, such as some highly active metal salt solutions), which will not be cleaned thoroughly and may easily cause the risk of overflow plating.

[0022] Furthermore, between S3 and S4, including:

[0023] Step A: According to design requirements, use the corresponding metal salt carrier solution, repeat S2-S3, and form a chemical plating area with different metal seed sources or a chemical plating area with a composite metal seed source on the surface of the 3D printed workpiece.

[0024] That is, if you want to form electroplating areas with different seed sources on the workpiece, you can activate different areas of the workpiece with lasers in different salt solution carriers, and use different specific electroplating solutions to achieve electroplating of different metal layers on the same workpiece surface; you can also immerse the same area of ​​the substrate in different salt solutions and activate the same area with lasers to form an electroplating area with a composite metal seed source, which will have higher compatibility with the subsequent electroplating solution.

[0025] Furthermore, graphene oxide or carbon powder is added to the metal salt carrier solution at a ratio of 0.5 to 3 g / L, and the graphene oxide or carbon powder can be used as a reducing agent in the laser activation process to promote the laser activation effect;

[0026] The average particle size of the graphene oxide or carbon powder is less than 200 nm. The smaller the average particle size, the larger the specific surface area and the better the reduction effect. The added concentration cannot be too high, otherwise it will affect the absorption of light energy by the carrier in the metal salt solution.

[0027] Furthermore, the solvent in the single-component metal salt carrier solution is ultrapure deionized water;

[0028] The preparation process of the multi-component metal salt carrier solution is as follows:

[0029] ①. Mixing each component metal salt carrier with ultrapure deionized water to form multiple single-component metal salt carrier solutions;

[0030] ② The obtained multiple single-component metal salt carrier solutions are mixed in a desired ratio to obtain a mixed metal salt carrier solution;

[0031] ③. Mix equal volumes of the mixed metal salt carrier solution and alcohol;

[0032] After overall mixing, ultrasound is required for 20 to 30 minutes before laser activation, and different laser activation energies should be selected according to the type of the prepared metal salt carrier solution;.

[0033] Furthermore, the temperature of the metal salt carrier solution is 40-60° C., which is beneficial to promoting the activity of the carrier solution ions during the laser activation process.

[0034] Further, in S3, the laser is a nanosecond laser (such as an ultraviolet nanosecond laser, 315nm, 355nm, 395nm, 410nm, etc.), a picosecond laser or a femtosecond laser; wherein, the picosecond laser or the femtosecond laser is a high-end laser with a relatively high cost. Considering the cost, the use of an ultraviolet nanosecond laser in the present invention can reduce the damage to the substrate and the influence of the roughness during the activation process;

[0035] The laser selects a multi-mode light source, and the generated light spot is a flat-top type with a spot diameter of less than 20 μm. Compared with a Gaussian spot, the overall energy distribution of the flat-top spot is more uniform. Therefore, in the activation area formed by scanning the spot, the distribution of metal seeds is also more uniform, which is crucial to the uniformity of the subsequent electroless plating metal layer.

[0036] Furthermore, in S3, when scanning the surface of the 3D printed polyetheretherketone workpiece under the liquid surface, a cross-type linear scan is performed according to the graph, and the scanning frequency is 80-120kHz, the scanning speed is 60-100mm / s, the defocus amount is 0-2mm, the overlap rate is 70-100%, and the laser pulse width is controlled to be 0.05-0.2us. The thickness of the deposited metal layer can be increased by increasing the number of scans.

[0037] Furthermore, in S4, after the 3D printed workpiece forming the chemical plating area is taken out, ultrasonic cleaning is adopted (the cleaning solution can be a mixture of deionized water and alcohol, or it can be pure water. In terms of cleaning effect, alcohol and some salt solutions are more soluble and have low surface tension, so they are easier to clean. Of course, suitable cleaning solutions can also be selected according to different types of metal salt carriers. For example, silver nitrate solution can be cleaned with sodium hydroxide solution), and the cleaning times are not less than 3 times.

[0038] Furthermore, in S4, during the electroless plating process, nitrogen is added to the electroless plating solution, and the flow rate is controlled at 0.1-0.5 L / min, which is beneficial to promote the exchange between the solution and the electroless plating area and reduce the metal oxides in the electroless plating area.

[0039] Furthermore, the material of the 3D printed workpiece is polyetheretherketone (PEEK), polyphenylene sulfide (PPS), polyimide (PI), polyamide (PA), polycarbonate (PC), and acrylonitrile-butadiene-styrene copolymer (ABS).

[0040] In addition, the present invention provides a 3D printed workpiece, which is special in that the metal pattern thereon is prepared by the above method.

[0041] Principle of the present invention:

[0042] The present invention uses one or more metal salt solutions (such as AgNO3, PdCl2, NiCl2, HAuCl4, H2PtCl6, FeCl3, ZnCl2, etc.) as carriers, immerses the surface-treated 3D printed workpiece (such as 3D printed PEEK workpiece) in the metal salt carrier solution, controls the activation surface of the substrate to be at a certain distance from the liquid surface, decomposes the metal salt solution by laser activation technology to generate activation seeds embedded in the surface of the activated substrate (such as the surface of the polyetheretherketone substrate), forms a metal particle / substrate blend (also called a metal activation layer, such as a metal particle / polyetheretherketone blend), and finally adopts a chemical plating method to selectively prepare a metal layer in the activated area, and a certain anchoring effect is generated between the metal layer and the dielectric layer (i.e., the metal activation layer, the polyetheretherketone activation area) due to the seed layer embedded in the dielectric layer, so that the metal layer prepared by chemical plating has excellent bonding strength. And because the activation process occurs in the carrier liquid, the thermal effect of the laser can be further reduced, and the damage of the laser to the heat-affected zone of the workpiece can be reduced. Furthermore, in order to obtain multiple types of seed layers on a workpiece surface, the substrate can be immersed in different types of metal salt carrier solutions (i.e., activation solutions) in a certain order and activated in different areas to obtain different seed layer areas on a substrate surface, so that different metal layers can be plated in different areas in subsequent chemical plating steps.

[0043] The advantages of the present invention are:

[0044] 1. The present invention uses a laser-induced deposition technology in a liquid environment to prepare a metal activation layer on the surface of a resin / ceramic workpiece through the pyrolysis of a laser. The activation layer serves as a catalytic center for subsequent chemical plating, so that a metal pattern can be selectively prepared on the surface of the workpiece. This method has a short preparation cycle, low cost, high precision, and strong metal layer bonding. At the same time, it will not change the internal structure of the resin / ceramic, and can effectively ensure that the dielectric constant and dielectric loss of the resin / ceramic dielectric plate will not increase due to the introduction of metal particles.

[0045] 2. The present invention can prepare high-precision and smooth metal patterning on the surface of 3D printing resin / ceramic. Compared with the existing laser activation method, the use of ordinary lasers (such as nano ultraviolet and infrared) can reduce the damage to the substrate and the impact of roughness during the activation process, thereby improving the smoothness and quality of the subsequent electroless plating surface metal layer, reducing roughness, and making it easier to apply industrially.

[0046] 3. The present invention can prepare composite metal seed sources and different metal seed sources in different regions on the same substrate surface through laser activation, thereby having higher compatibility with the electroplating solution. At the same time, different metal layers can be prepared by matching different seed sources with different electroplating solutions, avoiding the need for traditional electroplating to use metal layer stacking to electroplate different metal layers.

[0047] 4. The present invention is flexible and versatile and can be applied to various types of substrates, such as ceramics, PEEK, LCP, PPS, PI, PA, PC, ABS and other types of medium substrates. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 The surface morphology of the polyetheretherketone printed part provided by the present invention before being processed;

[0049] Figure 2 The morphology of the polyetheretherketone printed part after polishing provided by the present invention is (Ra0.14-Ra0.22);

[0050] Figure 3 The three-dimensional macroscopic morphology of polyetheretherketone after laser treatment provided by the present invention;

[0051] Figure 4 The metal pattern is prepared by the method of the present invention;

[0052] Figure 5 is the SEM microscopic morphology of the metal pattern prepared by the method of the present invention;

[0053] Figure 6 It is a laser activated polyetheretherketone curved metal pattern. DETAILED DESCRIPTION

[0054] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments:

[0055] Example 1

[0056] This embodiment demonstrates a method for preparing metal patterns by laser activation on the surface of 3D printed PEEK. Specifically, AgNO3 is selected as the salt solution (Sinopharm Chemical Reagent Co., Ltd.), a 3D printed polyetheretherketone sample (Shanghai Yuanzhu) is selected, and a 355nm ultraviolet nanosecond laser (Jept Seal-355-10s) is selected as the laser; the selected carbon powder particles D50 are 120nm (Ruijiang Metal Materials Co., Ltd.); the sealing glue comes from Delo DA255 glue.

[0057] Step 1: Surface polishing and sealing of 3D printed PEEK samples

[0058] First, you need to 3D print the polyetheretherketone sample, such as Figure 1As shown, the surface is polished to make it smooth. The print pattern will affect the roughness of the coating and the uniformity of laser activation, which may affect the bonding strength of the coating. Use 400-grit sandpaper for rough grinding to expose the holes that may exist in the printing. If there are holes, use sealing glue (DA255) to seal the holes and then cure them at 120℃ for 10min; continue to use 800-grit and 2000-grit sandpaper for polishing and 5000-grit sandpaper for fine polishing. The surface roughness of the sample reaches the range of Ra0.14~0.22, as shown in the figure. Figure 2 shown.

[0059] Step 2: 3D printed PEEK sample cleaning operation

[0060] Organic matter on the surface of the material will affect the effect of subsequent copper plating and the bonding strength, so this embodiment uses deionized water and ethanol to clean the surface of polyetheretherketone. First, put the polyetheretherketone into deionized water for ultrasonication for 10 minutes, then put it into ethanol for ultrasonication for 10 minutes, and finally put it into deionized water for cleaning for 10 minutes. The whole process is repeated more than 3 times to make the surface clean;

[0061] Step 3: Prepare AgNO3 carrier solution

[0062] Dissolve 0.75g AgNO3 in 50ml ultrapure deionized water to a solution concentration of 15g / L;

[0063] Based on the above solution, carbon powder with an average particle size of 120 nm was added at a ratio of 1 g / L, and placed under ultrasonic conditions for 40 minutes until it was completely dispersed;

[0064] Step 4: Immerse the processed 3D printed polyetheretherketone sample in the prepared AgNO3 mixed carrier solution, and adjust the distance from the activated surface of the sample to the liquid surface to 3 mm through a device (such as an existing thread adjustment device); adjust the laser focus to be located on the surface of the workpiece to be activated, and control the defocus amount within the range of 0 to 0.5 mm;

[0065] Step 5: Selectively activate the sample surface with laser. Scan the sample surface with 355nm pulsed ultraviolet nanosecond laser according to the metallization pattern. The scanning frequency is 120Khz, the scanning speed is 90mm / s, the overlap rate is 97%, the laser pulse width is controlled to be 0.08us, the scanning track is 0° and 90° cross scanning, the scanning number is 500 times, and the pattern is selectively formed, such as Figure 3 As shown, it can be seen that the roughness of the treated area has changed to a certain extent, indicating that the laser has activated the surface of the substrate;

[0066] Step 6: Take out the activated sample from the carrier solution. In order to further remove the AgNO3 adhering to the surface, the sample can be treated in a NaOH solution with a concentration of less than 3% for 5 to 10 minutes, and then washed in deionized water for 30 minutes. Repeat this for more than 3 times and dry for later use.

[0067] Step 7: Prepare the plating solution

[0068] A (8 g / L CuSO4·5H2O, 24 g / L potassium sodium tartrate, 14 g / L NaOH) and B (12 ml / L formaldehyde) were mixed in a ratio of 1:1 to prepare a chemical plating solution.

[0069] Step 8: Chemical Plating

[0070] The polyetheretherketone sample was placed in the electroless plating solution at 45°C, with 0.3L / min nitrogen introduced for 30 minutes.

[0071] Step 9: Clean the surface to get the coating

[0072] like Figure 4 and Figure 5 As shown, Figure 4 The copper layer formed after chemical plating can be seen in the figure. It can be seen that the metal pattern prepared by the method of the present invention has no obvious overflow area and the pattern boundary is clear; Figure 5 This is a scanning electron microscope image of the electroless plating layer. The overall metal layer is distributed relatively evenly, and there is no missed plating area, indicating that the activation is uniform and sufficient.

[0073] Similarly, the method of the present invention can also be used to prepare metal patterns on curved antennas, such as Figure 6 As shown, the graphic boundaries are clear and there is no obvious overflow area.

[0074] Example 2

[0075] This embodiment demonstrates a method for preparing iron metal patterns on a ceramic substrate by laser activation. Specifically, FeCl3 is selected as the salt solution (Sigma-Aldrich), an alumina ceramic substrate (thickness 1 mm) is selected as the substrate, and a 1064nm carbon dioxide laser (Dazzle Laser) is selected as the laser; the selected graphene oxide D50 is 120nm (Ruijiang Metal Materials Co., Ltd.).

[0076] Step 1: Substrate surface pretreatment

[0077] The surface roughness of the selected ceramic substrate should be lower than Ra0.3 as much as possible. If the roughness is too large, it may affect the electroless plating effect. Place the ceramic substrate in a mixture of deionized water and alcohol for more than 30 minutes, clean it with deionized water, and dry it for later use;

[0078] Step 2: Prepare carrier solution

[0079] Dissolve 2g FeCl3 powder in 500ml ultrapure deionized water to a solution concentration of 4g / L;

[0080] Based on the above solution, graphene oxide powder with an average particle size of 120 nm was added at a ratio of 2 g / L, and placed under ultrasonic conditions for 40 minutes until it was completely dispersed;

[0081] Step 3: Immerse the cleaned and spare ceramic substrate in the prepared FeCl3 mixed carrier solution, and adjust the distance from the activated surface of the ceramic substrate to the liquid surface to 0.8mm through the device; adjust the laser focus to the surface of the sample to be activated, and control the defocus amount within the range of 0 to 0.2mm;

[0082] Step 4: Selectively activate the surface of the sample with laser. The carbon dioxide laser scans the surface of the sample according to the metallization pattern. The scanning frequency is 300Khz, the scanning speed is 60mm / s, the overlap rate is 80%, the laser pulse width is controlled to be 0.05us, the scanning trajectory is -45° and +45° cross scanning, the scanning number is 300 times, and the pattern is selectively formed.

[0083] Step 5: Take out the activated sample from the carrier solution, wash it in deionized water for 30 minutes, repeat for more than 3 times, and dry it for later use;

[0084] Step 6: Prepare the chemical copper plating solution

[0085] The specific ratio is: anhydrous copper sulfate 15g / L, HIQSA solution 2-5ppm, formaldehyde 30g / L, NaOH 8-12g / L, PEG-6000 0.5-1.5ppm, SPS 0.2-1ppm, EDTA.2Na 30-32g / L;

[0086] Step 7: Chemical copper plating

[0087] The activated samples were placed in the electroless copper plating solution at 50°C with 0.5L / min nitrogen introduced for 30 minutes.

[0088] Example 3

[0089] This embodiment demonstrates a method for preparing a platinum-gold composite metal pattern by laser activation on a polyimide (PI) film. Specifically, H2PtCl6 is selected as the salt solution (8wt% Sigma-Aldrich) and HAuCl4 (30wt% Sigma-Aldrich), a polyimide film (50μm), and an 840nm infrared nanosecond laser (Hyper Laser) is selected as the laser; the average particle size of the selected graphene oxide is 160nm (Sigma-Aldrich).

[0090] Step 1: Sample surface pretreatment

[0091] The selected polyimide film has a thickness of 50 μm and Ra of 0.02. The polyimide film is placed in a mixture of deionized water and alcohol and ultrasonicated for more than 30 minutes, cleaned with deionized water, and dried for standby use;

[0092] Step 2: Prepare platinum salt and gold salt carrier solutions respectively

[0093] Dissolve H2PtCl6 solution in 100 ml ultrapure deionized water to make the solution concentration reach 3 g / L;

[0094] Dissolve HAuCl4 solution in ultrapure deionized water to a concentration of 0.25 g / L;

[0095] Adding graphene oxide powder with an average particle size of 160 nm to the above two metal salt carrier solutions respectively, wherein the ratio of graphene powder to platinum salt solution is 0.5 g / L, and the ratio of graphene powder to gold salt solution is 3 g / L, and placing them under ultrasonic conditions for 40 minutes respectively, so as to be completely dispersed;

[0096] Step 3: First, immerse the cleaned and ready-to-use polyimide film in the prepared platinum salt mixed carrier solution, and adjust the distance from the activated surface of the polyimide base film to the liquid surface to 1.2 mm through the device; adjust the laser focus to the surface of the sample to be activated, and control the defocus amount within the range of 0 to 0.3 mm;

[0097] The surface of the sample was selectively activated by laser. An 840nm nanosecond laser was used to scan the surface of the sample according to the metallization pattern. The scanning frequency was 300Khz, the scanning speed was 100mm / s, the overlap rate was 90%, the laser pulse width was controlled to be 0.02us, the scanning trajectory was cross-scanning at 0° and 90°, the scanning number was 1000 times, and a platinum metal pattern was selectively formed.

[0098] Step 4: Take out the activated sample from the platinum salt mixed carrier solution, wash it in deionized water for 30 minutes, repeat more than 3 times, and dry it for later use;

[0099] Step 5: Immerse the spare polyimide film in the prepared gold salt mixed carrier solution, and adjust the distance from the activated surface of the polyimide base film to the liquid surface to 0.3mm through the device; adjust the laser focus to the surface of the sample to be activated, and control the defocus amount within the range of 0 to 0.1mm;

[0100] The surface of the sample is selectively activated by laser. An 840nm nanosecond laser is used to scan the surface of the sample according to the metallization pattern. The scanning area can be overlapped with the previous scanning area or separated from the area according to the pattern design requirements. The specific laser activation parameters are: scanning frequency 500Khz, scanning speed 40mm / s, overlap rate 95%, laser pulse width controlled at 0.03us, scanning trajectory cross-scanning at -45° and 45°, scanning times 800 times, and a gold layer pattern is selectively formed.

[0101] Step 6: Take out the activated sample from the gold salt mixed carrier solution, wash it in deionized water for 30 minutes, repeat more than 3 times, and dry it for later use;

[0102] Step 7: Select commercial electroless plating solutions for platinum metal and gold layers respectively, and perform thickening treatments respectively;

[0103] Chemical plating thickening: Place the activated samples in different plating solutions at 60°C, introduce 0.1L / min nitrogen, and keep the plating time at 30 minutes.

[0104] Example 4

[0105] This embodiment demonstrates a method for preparing nickel metal patterns on polyphenylene sulfide (PPS) by laser activation. Specifically, NiCl2 is selected as the salt solution (Shanghai McLean Biochemical Technology Co., Ltd.), a polyphenylene sulfide substrate is selected as the substrate (Guocai New Materials, thickness 2mm), a 532nm laser is selected as the laser (Nanjing Lite-On); and the average particle size of the carbon powder particles is selected as 80nm (Bohuas Nanotechnology).

[0106] Step 1: Prepare carrier solution

[0107] Dissolve NiCl2 powder in 300 ml ultrapure deionized water and control the solution concentration to 1.8 g / L;

[0108] Based on the above solution, carbon powder with an average particle size of 80 nm was added at a ratio of 0.6 g / L, and placed under ultrasonic conditions for 30 minutes until it was completely dispersed;

[0109] Step 2: Immerse the cleaned and ready-to-use polyphenylene sulfide substrate in the prepared NiCl2 mixed carrier solution, and adjust the distance between the surface of the PPS substrate to be activated and the liquid surface to 0.5 mm through the device; adjust the laser focus to the surface of the sample to be activated, and control the defocus amount within the range of 0 to 0.5 mm;

[0110] Step 3: Selectively activate the surface of the sample by laser, and use a 532nm wavelength nanolaser to scan the surface of the sample according to the metallization pattern. The scanning frequency is 600Khz, the scanning speed is 50mm / s, the overlap rate is 60%, the laser pulse width is controlled to be 0.03us, the scanning trajectory is -45° and +45° cross scanning, the scanning number is 800 times, and the nickel metal layer pattern is selectively formed.

[0111] Step 4: Take out the activated sample from the carrier solution, wash it in deionized water for 30 minutes, repeat for more than 3 times, and dry it for later use;

[0112] Step 5: Prepare the gold plating solution

[0113] The specific ratio is: potassium gold cyanide 0.02 mol / L, sodium ascorbate 1.00 mol / L, cuprous cyanide (calculated as copper) 10.00 mg / L, potassium cyanide 0.0005 mol / L, and appropriate amount of citric acid (based on the pH value being adjusted to 7);

[0114] Step 6: Chemical gold plating

[0115] The activated samples were placed in a gold plating solution at 90°C with 0.5L / min nitrogen gas introduced for 30 minutes.

[0116] Similarly, the samples after chemical plating in Example 2 to Example 4 were observed and tested, and it was found that the prepared metal patterns had clear boundaries, the metal layer was evenly distributed, and there was no obvious overflow or leakage area.

[0117] In summary, the present invention prepares a metal layer on the surface of an FDM (melt extrusion) resin / ceramic print part by laser activation and chemical plating.

[0118] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should be included in the protection scope of the present invention.

Claims

1. A method for preparing metal patterns by laser activation of 3D printing resin / ceramic surface, characterized in that: The following steps are involved: S1. Surface preparation Mechanically polish the surface of the 3D printed workpiece made of resin or ceramic, use resin glue to seal the holes exposed by the polishing, and then perform mechanical polishing again after curing to ensure that the roughness of the workpiece surface is less than Ra0.3, and then ultrasonically clean it to obtain a processed 3D printed workpiece; S2. Immersion Immerse the 3D printed workpiece treated with S1 in the metal salt carrier solution, and control the distance between the activated surface of the workpiece and the liquid surface to be no more than 5 mm; The metal salt carrier solution is a single-component metal salt carrier solution or a multi-component metal salt carrier solution, and the prepared concentration is 0.1 to 50 g / L; S3. Activation After using the laser to control the focal length, the surface of the 3D printed workpiece under the liquid surface is scanned and activated according to the design pattern to form a chemical plating area on the surface of the 3D printed workpiece. The laser power is selected to be 0.03~10W; S4. Chemical Plating After the 3D printed workpiece with the chemical plating area is taken out and cleaned, a metal seed layer is deposited on the surface of the workpiece by chemical plating process to perform universal chemical plating treatment to complete the preparation of metal patterns; Among them, the 3D printed workpiece with the chemical plating area formed should be cleaned within 2 hours after being taken out.

2. The method for preparing metal patterns by laser activation of 3D printing resin / ceramic surface according to claim 1, characterized in that: Between S3 and S4, including: Step A: According to design requirements, use the corresponding metal salt carrier solution, repeat S2-S3, and form a chemical plating area with different metal seed sources or a chemical plating area with a composite metal seed source on the surface of the 3D printed workpiece.

3. The method for preparing metal patterns by laser activation of 3D printing resin / ceramic surface according to claim 1, characterized in that: Adding graphene oxide or carbon powder to the metal salt carrier solution at a ratio of 0.5 to 3 g / L; The average particle size of the graphene oxide or carbon powder is less than 200 nm.

4. The method for preparing metal patterns by laser activation of 3D printing resin / ceramic surface according to claim 1, characterized in that: The solvent in the single-component metal salt carrier solution is ultrapure deionized water; The preparation process of the multi-component metal salt carrier solution is as follows: ①. Mixing each component metal salt carrier with ultrapure deionized water to form multiple single-component metal salt carrier solutions; ② The obtained multiple single-component metal salt carrier solutions are mixed in a desired ratio to obtain a mixed metal salt carrier solution; ③. Mix equal volumes of the mixed metal salt carrier solution and alcohol.

5. The method for preparing metal patterns by laser activation of 3D printing resin / ceramic surface according to any one of claims 1 to 4, characterized in that: The temperature of the metal salt carrier solution is 40-60°C.

6. The method for preparing metal patterns by laser activation of 3D printing resin / ceramic surface according to claim 5, characterized in that: In S3, the laser is a nanosecond laser, a picosecond laser or a femtosecond laser; The laser selects a multi-mode light source, and the generated light spot is flat-top type, and the diameter of the light spot is less than 20 μm.

7. The method for preparing metal patterns by laser activation of 3D printing resin / ceramic surface according to claim 6, characterized in that: In S3, when scanning the surface of the 3D printed workpiece under the liquid surface, a cross-type linear scan is performed according to the graph, and the scanning frequency is 80-120kHz, the scanning speed is 60-100mm / s, the defocus is 0-2mm, the overlap rate is 70-100%, and the laser pulse width is controlled to be 0.05-0.2us.

8. The method for preparing metal patterns by laser activation of 3D printing resin / ceramic surface according to claim 7, characterized in that: In S4, after the 3D printed workpiece with the chemical plating area formed is taken out, ultrasonic cleaning is performed, and the number of cleaning times is not less than 3 times; During the electroless plating process, nitrogen is charged into the electroless plating solution, and the flow rate is controlled at 0.1 to 0.5 L / min.

9. The method for preparing metal patterns by laser activation of 3D printing resin / ceramic surface according to claim 1, characterized in that: The material of the 3D printing workpiece is polyetheretherketone, polyphenylene sulfide, polyimide, polyamide, polycarbonate, and acrylonitrile-butadiene-styrene copolymer.

10. A 3D printed workpiece, characterized in that: The metal pattern thereon is prepared by the method described in any one of claims 1-9.

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