Selective metallization method for transparent plastic base material

Abstract

The invention provides a selective metallization method for a transparent plastic base material, and belongs to the field of metallization of transparent plastic materials. According to the method, the surface of a transparent plastic base material is coated with laser sensitizer ink through a blade coating method, then the uncoated surface of the plastic base material is subjected to laser irradiation etching treatment, laser penetrates through the plastic material to conduct activating treatment on a laser sensitizer, and a needed conductive metal pattern is obtained after chemical copper plating. The adhesive force between the prepared metal pattern and the transparent plastic material reaches the ASTM D33595B standard, the thickness of the metal copper layer reaches 5 [mu] m or above, the conductivity reaches 107 S / m, the industrial application requirement is completely met, compared with photoetching, ink printing and laser direct forming technologies, a mask is not needed, the use amount of a laser sensitizer can be greatly reduced, and the cost is reduced. Meanwhile, the laser-induced activation efficiency is improved, and the method has very good economic benefits, is simple in process and is suitable for industrial production and application.

Description

Technical Field

[0001] The present invention belongs to the field of metallization of transparent plastic materials, and particularly relates to the preparation of metallized patterns on the surface of transparent plastic substrates by coating laser sensitizer inks and laser-induced activation. Background Art

[0002] The surface selective metallization of transparent plastic materials combines the excellent properties of both metal and plastic materials and is widely used in fields such as electronic communication, instruments, and decoration. Existing methods for the selective metallization of insulating materials mainly include photolithography, ink printing, laser-assisted processing and manufacturing, etc. In the traditional laser direct structuring (LDS) technology, special laser sensitizers first need to be added to the plastic substrate, and the laser sensitizers near the substrate surface are activated by laser to function. The laser sensitizers inside the plastic substrate are inevitably wasted, which increases the production cost. To improve the utilization efficiency of laser sensitizers, the laser sensitizers are coated on the surface of the transparent substrate, and a metal copper layer is obtained through laser-induced activation and electroless copper plating reactions. However, the current technology irradiates and etches the surface of the side coated with the laser sensitizer by laser, so the effect of laser activation is not good, and the adhesion between the copper layer and the plastic substrate after electroless copper plating is poor and easy to fall off.

[0003] In order to overcome the defects of poor adhesion and low conductivity of the existing selective metallization of transparent plastic materials, it is necessary to find or develop a method with high laser activation efficiency, simple process flow, and small addition amount of laser sensitizers. The present invention combines the coating of laser sensitizer and the laser irradiation and etching of the surface of the side not coated with the laser sensitizer, and the required metallized pattern is obtained after the electroless copper plating reaction, which can be used for conductive metal circuits, decorative graphics, electric heaters, etc. Summary of the Invention

[0004] The present invention mainly overcomes the deficiencies in the prior art and provides a method for the selective metallization of transparent plastic substrates, belonging to the field of metallization of transparent plastic materials; this method uses a doctor blade coating method to coat a laser sensitizer ink on the surface of the transparent plastic substrate, and then uses laser irradiation and etching to process the surface of the uncoated plastic substrate. The laser passes through the plastic material to activate the laser sensitizer, and the required conductive metal pattern is obtained after electroless copper plating; the adhesion between the metal pattern prepared by the present invention and the transparent plastic material reaches the ASTM D3359 5B standard, the thickness of the metal copper layer reaches more than 5 μm, and the conductivity reaches 10 7 S / m, fully meeting the requirements of industrial applications. Compared with photolithography, ink printing, and laser direct structuring technology, the present invention does not require a mask and can greatly reduce the usage amount of laser sensitizers, while improving the laser-induced activation efficiency, having very good economic benefits, simple process, and being suitable for industrial production applications.

[0005] To achieve the above technical objectives, the technical solution adopted by the present invention is as follows: A method for selective metallization of a transparent plastic substrate, comprising the following steps: Step S1: Prepare a laser sensitizer ink by mixing a general laser sensitizer with a solvent, and coat it on one side surface of the transparent plastic substrate by means of scraping. Step S2: Use laser irradiation to etch the other side surface of the transparent plastic that is not coated with the laser sensitizer ink, so that the laser penetrates through the plastic material to perform laser-induced activation treatment on the laser sensitizer ink. Step S3: Clean the transparent plastic substrate after the laser-induced activation treatment in Step S2, and rinse off the excess laser sensitizer ink; then carry out electroless copper plating reaction to prepare the required selective metallization pattern.

[0006] Further, the general laser sensitizer is any one or more of copper oxide, cuprous oxide, basic copper phosphate, copper oxalate, basic copper carbonate, copper acetylacetonate, copper nitrate, and copper pyrophosphate containing copper element in the molecular structure; the average particle size of the laser sensitizer containing copper element is 30-200 nm.

[0007] Further, the general laser sensitizer is any one or more of antimony tin oxide, zinc oxide, molybdenum oxide, and cobalt oxide without copper element in the molecular structure; the average particle size of the laser sensitizer without copper element is 50-150 nm.

[0008] Further, the solvent is one or more of methanol, ethanol, propanol, tetrahydrofuran, cyclohexane, dichloromethane, and water.

[0009] Further, the transparent plastic substrate is any one of polyethylene terephthalate, polycarbonate, polymethyl methacrylate, polystyrene, polypropylene, transparent nylon, thermoplastic polyurethane elastomer, silicone rubber, styrene thermoplastic elastomer, polyphenylene sulfide, liquid crystal polymer, and cycloolefin copolymer.

[0010] Further, the laser is a pulsed laser, the wavelength of the laser is 355-1064 nm, the laser frequency is 5-100 kHz, the laser power is 1-30 W, and the laser scanning speed is 100-3000 mm / s.

[0011] Further, the conditions for electroless copper plating are: using a formaldehyde system or a sodium hypophosphite system as a reducing agent, copper salt to provide copper ions, potassium sodium tartrate, sodium ethylenediaminetetraacetate, and sodium citrate as complexing agents, and sodium hydroxide to adjust the pH value of the copper plating solution; the reaction time for electroless copper plating is 2-60 min, the thickness of the electroless copper plating layer is 3-15 μm, and the adhesion between the metal copper layer and the transparent plastic substrate reaches the ASTM D3359 5B standard.

[0012] Further, the average particle size of the general laser sensitizer is 5 - 300 nm.

[0013] Further, the laser sensitizer ink is composed of the following components by weight percentage: 1% - 90% of the general laser sensitizer and 10% - 90% of the solvent.

[0014] Further, the uses of the metallized pattern include conductive metal circuits, decorative graphics, and electric heaters.

[0015] Beneficial effects Compared with the prior art, the present invention has the following advantages: According to the method of the present invention, after coating with the laser sensitizer ink, laser irradiation to etch the uncoated surface of the transparent plastic, and electroless copper plating, the thickness of the obtained copper layer on the surface of the transparent plastic material reaches more than 5 μm, and the adhesion between the copper plating layer and the transparent plastic material reaches the 5B standard of ASTM D3359, achieving a technical effect completely unexpected by those skilled in the art; moreover, the laser sensitizer ink provided by the present invention, without the need for a mask, combines laser irradiation etching and selective metallization, and is suitable for high-precision conductive metal patterns. In addition, the present invention can significantly reduce the dosage of the laser sensitizer, reduce the cost of selective metallization, and is particularly suitable for industrialization. Description of the drawings

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. The drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained according to the provided drawings without creative efforts.

[0017] Figure 1 It is a physical diagram of the selective metallization of the transparent plastic substrate in the embodiment of the present invention; Figure 2 It is a scanning electron microscope image of the electroless copper plating layer in the embodiment of the present invention; Figure 3 It is a crosshatch tape adhesion test result diagram of the electroless copper plating layer in the embodiment of the present invention. Detailed implementation manners

[0018] In order to make the purpose, technical solutions and advantages of the present invention clearer, the following further describes the present invention in detail with reference to the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0019] Definitions of terms used in the present invention: Unless otherwise stated, the initial definitions provided for groups or terms in this document apply to the groups or terms throughout the specification; for terms that are not specifically defined herein, they should be given the meaning that a person skilled in the art would give them based on the disclosure and context.

[0020] Obviously, based on the above contents of the present invention, according to common technical knowledge and customary means in this field, without departing from the above basic technical ideas of the present invention, other various forms of modifications, replacements or changes can be made.

[0021] The following further describes the above content of the present invention in detail through specific embodiments in the form of examples. However, this should not be construed as limiting the scope of the above subject matter of the present invention to the following examples. All technologies implemented based on the above content of the present invention fall within the scope of the present invention.

[0022] The transparent plastic materials and experimental processing equipment used in the specific implementation cases of the present invention are all known products and are obtained by purchasing commercial products.

[0023] Polyethylene terephthalate (PET), polycarbonate (PC), polymethyl methacrylate (PMMA), polystyrene (PS), polypropylene (PP), transparent nylon (PA), polyimide (PI), thermoplastic polyurethane (TPU), silicone rubber, styrene-based thermoplastic elastomer, polyphenylene sulfide (PPS), liquid crystal polymer (LCP), cyclic olefin copolymer (COC), basic copper phosphate, copper oxalate, antimony tin oxide, cyclohexane, and ethanol were purchased from Aladdin.

[0024] Example 1: 10 wt.% basic copper phosphate and 90 wt.% ethanol were thoroughly stirred and mixed to prepare a laser sensitizer ink. The laser sensitizer ink was then coated on the surface of a transparent PI substrate with a coating thickness of approximately 20 μm. The surface of the transparent plastic side not coated with the laser sensitizer was etched and irradiated by laser. The laser used was a near-infrared pulsed laser with a laser wavelength of 1064 nm, a laser power of 15 W, a laser frequency of 10 kHz, and a laser scanning speed of 500 mm / s. After laser-induced activation, the excess laser sensitizer ink was washed off with deionized water; copper was plated using a chemical plating process, with formaldehyde as a reducing agent, copper salt providing copper ions, potassium sodium tartrate, sodium ethylenediaminetetraacetic acid, and sodium citrate as complexing agents, and sodium hydroxide used to adjust the pH value of the copper plating solution to 12.5, and the plating effect was evaluated. The adhesion between the copper plating layer and the substrate was evaluated according to the ASTM D3359 standard, and the thickness of the copper plating layer was tested according to ASTM B568 (2009). The test results are shown in Table 1. Figure 1 As shown, Figure 1This is a physical diagram of the selective metallization of a transparent plastic substrate in an embodiment of the present invention.

[0025] Example 2: Prepare a laser sensitizer ink by fully stirring and mixing 20 wt.% cupric basic phosphate and 80 wt.% ethanol. The test method is the same as that in Example 1. The laser used is a near-infrared pulsed laser with a laser wavelength of 1064 nm, a laser power of 10 W, a laser frequency of 20 kHz, and a laser scanning speed of 700 mm / s. Evaluate the adhesion effect between the copper plating layer and the substrate according to the ASTM D3359 standard, and measure the thickness of the copper plating layer according to ASTM B568 (2009). The test results are shown in Table 1.

[0026] Example 3: Prepare a laser sensitizer ink by fully stirring and mixing 30 wt.% cupric basic phosphate and 70 wt.% ethanol. The test method is the same as that in Example 1. The laser used is a near-infrared pulsed laser with a laser wavelength of 1064 nm, a laser power of 5 W, a laser frequency of 30 kHz, and a laser scanning speed of 900 mm / s. Evaluate the adhesion effect between the copper plating layer and the substrate according to the ASTM D3359 standard, and measure the thickness of the copper plating layer according to ASTM B568 (2009). The test results are shown in Table 1.

[0027] Example 4: Prepare a laser sensitizer ink by fully stirring and mixing 40 wt.% cupric basic phosphate and 60 wt.% ethanol. The test method is the same as that in Example 1. The laser used is a visible light pulsed laser with a laser wavelength of 532 nm, a laser power of 15 W, a laser frequency of 40 kHz, and a laser scanning speed of 1100 mm / s. Evaluate the adhesion effect between the copper plating layer and the substrate according to the ASTM D3359 standard, and measure the thickness of the copper plating layer according to ASTM B568 (2009). The test results are shown in Table 1.

[0028] Example 5: Prepare a laser sensitizer ink by fully stirring and mixing 50 wt.% cupric basic phosphate and 50 wt.% ethanol. The test method is the same as that in Example 1. The laser used is a visible light pulsed laser with a laser wavelength of 532 nm, a laser power of 10 W, a laser frequency of 50 kHz, and a laser scanning speed of 1300 mm / s. Evaluate the adhesion effect between the copper plating layer and the substrate according to the ASTM D3359 standard, and measure the thickness of the copper plating layer according to ASTM B568 (2009). The test results are shown in Table 1.

[0029] Example 6: Prepare a laser sensitizer ink by thoroughly stirring and mixing 60 wt.% cupric basic phosphate with 40 wt.% ethanol. The test method is the same as that in Example 1. The laser used is a visible light pulsed laser with a laser wavelength of 532 nm, a laser power of 5 W, a laser frequency of 60 kHz, and a laser scanning speed of 1500 mm / s. Evaluate the adhesion effect between the copper plating layer and the substrate according to the ASTM D3359 standard, and measure the thickness of the copper plating layer according to ASTM B568 (2009). The test results are shown in Table 1.

[0030] Example 7: Prepare a laser sensitizer ink by thoroughly stirring and mixing 70 wt.% cupric basic phosphate with 30 wt.% ethanol. The test method is the same as that in Example 1. The laser used is an ultraviolet pulsed laser with a laser wavelength of 355 nm, a laser power of 15 W, a laser frequency of 60 kHz, and a laser scanning speed of 1700 mm / s. Evaluate the adhesion effect between the copper plating layer and the substrate according to the ASTM D3359 standard, and measure the thickness of the copper plating layer according to ASTM B568 (2009). The test results are shown in Table 1.

[0031] Example 8: Prepare a laser sensitizer ink by thoroughly stirring and mixing 80 wt.% cupric basic phosphate with 20 wt.% ethanol. The test method is the same as that in Example 1. The laser used is an ultraviolet pulsed laser with a laser wavelength of 355 nm, a laser power of 10 W, a laser frequency of 70 kHz, and a laser scanning speed of 2000 mm / s. Evaluate the adhesion effect between the copper plating layer and the substrate according to the ASTM D3359 standard, and measure the thickness of the copper plating layer according to ASTM B568 (2009). The test results are shown in Table 1.

[0032] Example 9: Prepare a laser sensitizer ink by thoroughly stirring and mixing 90 wt.% cupric basic phosphate with 10 wt.% ethanol. The test method is the same as that in Example 1. The laser used is an ultraviolet pulsed laser with a laser wavelength of 355 nm, a laser power of 5 W, a laser frequency of 80 kHz, and a laser scanning speed of 2500 mm / s. Evaluate the adhesion effect between the copper plating layer and the substrate according to the ASTM D3359 standard, and measure the thickness of the copper plating layer according to ASTM B568 (2009). The test results are shown in Table 1.

[0033] Example 10: Prepare a laser sensitizer ink by thoroughly stirring and mixing 10 wt.% copper oxalate with 90 wt.% cyclohexane. Then coat the laser sensitizer ink on the surface of a transparent PET substrate. Use a laser to perform etching irradiation on the surface of the transparent plastic without the coated laser sensitizer. The laser used is a near-infrared pulsed laser with a laser wavelength of 1064 nm, a laser power of 15 W, a laser frequency of 20 kHz, and a laser scanning speed of 600 mm / s. After laser-induced activation, wash off the excess laser sensitizer ink with deionized water; perform copper plating through an electroless plating process, using formaldehyde as the reducing agent, copper salt to provide copper ions, potassium sodium tartrate, sodium ethylenediaminetetraacetate, and sodium citrate as complexing agents, and sodium hydroxide to adjust the pH value of the copper plating solution to 12.5. Evaluate the adhesion effect between the copper plating layer and the substrate according to ASTM D3359 standard, and measure the thickness of the copper plating layer according to ASTM B568 (2009). The test results are shown in Table 1.

[0034] Example 11: Prepare a laser sensitizer ink by thoroughly stirring and mixing 20 wt.% copper oxalate with 80 wt.% cyclohexane. The test method is the same as that of Example 10. The laser used is a near-infrared pulsed laser with a laser wavelength of 1064 nm, a laser power of 10 W, a laser frequency of 40 kHz, and a laser scanning speed of 800 mm / s. Evaluate the adhesion effect between the copper plating layer and the substrate according to ASTM D3359 standard, and measure the thickness of the copper plating layer according to ASTM B568 (2009). The test results are shown in Table 1.

[0035] Example 12: Prepare a laser sensitizer ink by thoroughly stirring and mixing 30 wt.% copper oxalate with 70 wt.% cyclohexane. The test method is the same as that of Example 10. The laser used is a near-infrared pulsed laser with a laser wavelength of 1064 nm, a laser power of 5 W, a laser frequency of 60 kHz, and a laser scanning speed of 1000 mm / s. Evaluate the adhesion effect between the copper plating layer and the substrate according to ASTM D3359 standard, and measure the thickness of the copper plating layer according to ASTM B568 (2009). The test results are shown in Table 1.

[0036] Example 13: Prepare a laser sensitizer ink by thoroughly stirring and mixing 40 wt.% copper oxalate with 60 wt.% cyclohexane. The test method is the same as that of Example 10. The laser used is a visible light pulsed laser with a laser wavelength of 532 nm, a laser power of 15 W, a laser frequency of 60 kHz, and a laser scanning speed of 1500 mm / s. Evaluate the adhesion effect between the copper plating layer and the substrate according to ASTM D3359 standard, and measure the thickness of the copper plating layer according to ASTM B568 (2009). The test results are shown in Table 1.

[0037] Example 14: 50 wt.% copper oxalate and 50 wt.% cyclohexane were fully stirred and mixed to prepare a laser sensitizer ink. The test method was the same as that in Example 10. The laser used was a visible light pulsed laser with a laser wavelength of 532 nm, a laser power of 10 W, a laser frequency of 70 kHz, and a laser scanning speed of 1800 mm / s. The adhesion effect between the copper plating layer and the substrate was evaluated according to the ASTM D3359 standard, and the thickness of the copper plating layer was measured according to ASTM B568 (2009). The test results are shown in Table 1.

[0038] Example 15: 60 wt.% copper oxalate and 40 wt.% cyclohexane were fully stirred and mixed to prepare a laser sensitizer ink. The test method was the same as that in Example 10. The laser used was a visible light pulsed laser with a laser wavelength of 532 nm, a laser power of 5 W, a laser frequency of 80 kHz, and a laser scanning speed of 2000 mm / s. The adhesion effect between the copper plating layer and the substrate was evaluated according to the ASTM D3359 standard, and the thickness of the copper plating layer was measured according to ASTM B568 (2009). The test results are shown in Table 1.

[0039] Example 16: 70 wt.% copper oxalate and 30 wt.% cyclohexane were fully stirred and mixed to prepare a laser sensitizer ink. The test method was the same as that in Example 10. The laser used was an ultraviolet pulsed laser with a laser wavelength of 355 nm, a laser power of 15 W, a laser frequency of 80 kHz, and a laser scanning speed of 2500 mm / s. The adhesion effect between the copper plating layer and the substrate was evaluated according to the ASTM D3359 standard, and the thickness of the copper plating layer was measured according to ASTM B568 (2009). The test results are shown in Table 1.

[0040] Example 17: 80 wt.% copper oxalate and 20 wt.% cyclohexane were fully stirred and mixed to prepare a laser sensitizer ink. The test method was the same as that in Example 10. The laser used was an ultraviolet pulsed laser with a laser wavelength of 355 nm, a laser power of 10 W, a laser frequency of 60 kHz, and a laser scanning speed of 2500 mm / s. The adhesion effect between the copper plating layer and the substrate was evaluated according to the ASTM D3359 standard, and the thickness of the copper plating layer was measured according to ASTM B568 (2009). The test results are shown in Table 1.

[0041] Example 18: Prepare a laser sensitizer ink by thoroughly stirring and mixing 90 wt.% copper oxalate with 10 wt.% cyclohexane. The test method is the same as that of Example 10. The laser used is an ultraviolet pulsed laser with a laser wavelength of 355 nm, a laser power of 5 W, a laser frequency of 60 kHz, and a laser scanning speed of 3000 mm / s. Evaluate the adhesion effect between the copper-plated layer and the substrate according to ASTM D3359 standard, and measure the thickness of the copper-plated layer according to ASTM B568 (2009). The test results are shown in Table 1.

[0042] Example 19: Prepare a laser sensitizer ink by thoroughly stirring and mixing 10 wt.% antimony tin oxide with 90 wt.% water. Then coat the laser sensitizer ink on the surface of a transparent LCP substrate. Use a laser to perform etching irradiation treatment on the surface of the transparent plastic without coating the laser sensitizer. The laser used is a near-infrared pulsed laser with a laser wavelength of 1064 nm, a laser power of 18 W, a laser frequency of 20 kHz, and a laser scanning speed of 600 mm / s. After laser-induced activation, wash off the excess laser sensitizer ink with deionized water; perform electroless copper plating through a chemical plating process, using sodium hypophosphite as a reducing agent, copper salt to provide copper ions, potassium sodium tartrate, sodium ethylenediaminetetraacetate, and sodium citrate as complexing agents, and sodium hydroxide to adjust the pH value of the electroless copper plating solution to 12.5. Perform electroless copper plating through a chemical plating process and evaluate the plating effect. Evaluate the adhesion effect between the copper-plated layer and the substrate according to ASTM D3359 standard, and measure the thickness of the copper-plated layer according to ASTM B568 (2009). The test results are shown in Table 1.

[0043] Example 20: Prepare a laser sensitizer ink by thoroughly stirring and mixing 20 wt.% antimony tin oxide with 80 wt.% water. The test method is the same as that of Example 19. The laser used is a near-infrared pulsed laser with a laser wavelength of 1064 nm, a laser power of 14 W, a laser frequency of 30 kHz, and a laser scanning speed of 800 mm / s. Evaluate the adhesion effect between the copper-plated layer and the substrate according to ASTM D3359 standard, and measure the thickness of the copper-plated layer according to ASTM B568 (2009). The test results are shown in Table 1.

[0044] Example 21: Prepare a laser sensitizer ink by fully stirring and mixing 30 wt.% antimony tin oxide with 70 wt.% water. The test method is the same as that in Example 19. The laser used is a near-infrared pulsed laser with a laser wavelength of 1064 nm, a laser power of 10 W, a laser frequency of 40 kHz, and a laser scanning speed of 1000 mm / s. Evaluate the adhesion effect between the copper-plated layer and the substrate according to the ASTM D3359 standard, and measure the thickness of the copper-plated layer according to ASTM B568 (2009). The test results are shown in Table 1.

[0045] Example 22: Prepare a laser sensitizer ink by fully stirring and mixing 40 wt.% antimony tin oxide with 60 wt.% water. The test method is the same as that in Example 19. The laser used is a visible-light pulsed laser with a laser wavelength of 532 nm, a laser power of 18 W, a laser frequency of 50 kHz, and a laser scanning speed of 1200 mm / s. Evaluate the adhesion effect between the copper-plated layer and the substrate according to the ASTM D3359 standard, and measure the thickness of the copper-plated layer according to ASTM B568 (2009). The test results are shown in Table 1.

[0046] Example 23: Prepare a laser sensitizer ink by fully stirring and mixing 50 wt.% antimony tin oxide with 50 wt.% water. The test method is the same as that in Example 19. The laser used is a visible-light pulsed laser with a laser wavelength of 532 nm, a laser power of 14 W, a laser frequency of 60 kHz, and a laser scanning speed of 1500 mm / s. Evaluate the adhesion effect between the copper-plated layer and the substrate according to the ASTM D3359 standard, and measure the thickness of the copper-plated layer according to ASTM B568 (2009). The test results are shown in Table 1.

[0047] Example 24: Prepare a laser sensitizer ink by fully stirring and mixing 60 wt.% antimony tin oxide with 40 wt.% water. The laser used is a visible-light pulsed laser with a laser wavelength of 532 nm, a laser power of 10 W, a laser frequency of 60 kHz, and a laser scanning speed of 2000 mm / s. The test method is the same as that in Example 19. Evaluate the adhesion effect between the copper-plated layer and the substrate according to the ASTM D3359 standard, and measure the thickness of the copper-plated layer according to ASTM B568 (2009). The test results are shown in Table 1.

[0048] Example 25: Prepare a laser sensitizer ink by thoroughly stirring and mixing 70 wt.% antimony tin oxide with 30 wt.% water. The test method is the same as that of Example 19. The laser used is an ultraviolet pulsed laser with a laser wavelength of 355 nm, a laser power of 18 W, a laser frequency of 70 kHz, and a laser scanning speed of 2000 mm / s. Evaluate the adhesion effect between the copper-plated layer and the substrate according to ASTM D3359 standard, and measure the thickness of the copper-plated layer according to ASTM B568 (2009). The test results are shown in Table 1.

[0049] Example 26: Prepare a laser sensitizer ink by thoroughly stirring and mixing 80 wt.% antimony tin oxide with 20 wt.% water. The test method is the same as that of Example 19. The laser used is an ultraviolet pulsed laser with a laser wavelength of 355 nm, a laser power of 14 W, a laser frequency of 80 kHz, and a laser scanning speed of 2000 mm / s. Evaluate the adhesion effect between the copper-plated layer and the substrate according to ASTM D3359 standard, and measure the thickness of the copper-plated layer according to ASTM B568 (2009). The test results are shown in Table 1.

[0050] Example 27: Prepare a laser sensitizer ink by thoroughly stirring and mixing 90 wt.% antimony tin oxide with 10 wt.% water. The laser used is an ultraviolet pulsed laser with a laser wavelength of 355 nm, a laser power of 10 W, a laser frequency of 80 kHz, and a laser scanning speed of 2500 mm / s. The test method is the same as that of Example 19. Evaluate the adhesion effect between the copper-plated layer and the substrate according to ASTM D3359 standard, and measure the thickness of the copper-plated layer according to ASTM B568 (2009). The test results are shown in Table 1.

[0051] Comparative Example 1: Based on Example 1, the difference is only that the laser sensitizer ink in Example 1 is not coated; directly use a laser to etch and activate one side of the PI substrate and perform selective metallization. The laser used is a near-infrared pulsed laser with a laser wavelength of 1064 nm, a laser power of 15 W, a laser frequency of 10 kHz, and a laser scanning speed of 500 mm / s. Conduct electroless copper plating through an electroless plating process and evaluate the plating effect. Evaluate the adhesion effect between the copper-plated layer and the substrate according to ASTM D3359 standard, and measure the thickness of the copper-plated layer according to ASTM B568 (2009). The test results are shown in Table 1.

[0052] Comparative Example 2: Based on Example 1, 10 wt.% of basic copper phosphate and 90 wt.% of ethanol were fully stirred and mixed to prepare a laser sensitizer ink. Then, the laser sensitizer ink was coated on the surface of a transparent PI substrate, and the coating thickness was about 20 μm. The side surface of the transparent plastic coated with the laser sensitizer was subjected to etching irradiation treatment using a laser. The laser used was a near-infrared pulsed laser with a laser wavelength of 1064 nm, a laser power of 15 W, a laser frequency of 10 kHz, and a laser scanning speed of 500 mm / s. After laser-induced activation, the excess laser sensitizer ink was washed off with deionized water; copper plating was carried out by electroless plating process, formaldehyde was used as a reducing agent, copper salt provided copper ions, potassium sodium tartrate, sodium ethylenediaminetetraacetate, and sodium citrate were used as complexing agents, and sodium hydroxide was used to adjust the pH value of the copper plating solution to 12.5 to evaluate the plating effect. According to ASTM D3359 standard, the adhesion effect between the copper plating layer and the substrate was evaluated, and according to ASTM B568 (2009), the thickness of the copper plating layer was measured. The test results are shown in Table 1.

[0053] Comparative Example 3: Based on Example 25, 70wt.% of antimony tin oxide and 30wt.% of water were fully stirred and mixed to prepare a laser sensitizer ink. The test method was the same as that of Example 19, and the only difference was that the side surface of the transparent plastic coated with the laser sensitizer was subjected to etching irradiation treatment using a laser. The laser used was an ultraviolet pulsed laser with a laser wavelength of 355 nm, a laser power of 18 W, a laser frequency of 70 kHz, and a laser scanning speed of 2000 mm / s. According to ASTM D3359 standard, the adhesion effect between the copper plating layer and the substrate was evaluated, and according to ASTM B568 (2009), the thickness of the copper plating layer was measured. The test results are shown in Table 1.

[0054] Table 1 Test Results of Examples 1 - 27 and Comparative Examples 1 - 3 As Figure 2 shown, the results indicate that a method for selective metallization of a transparent plastic substrate proposed by the present invention uses laser sensitizer coating and laser irradiation etching to obtain a conductive metal pattern. The laser sensitizer was respectively coated on the surfaces of PI, PET, and LCP substrates, and then the other side of the transparent plastic substrate was subjected to laser-induced activation treatment using near-infrared laser, visible light laser, and ultraviolet laser respectively. After electroless copper plating, the required conductive metal pattern was obtained. As Figure 3 shown, Figure 3 is the cross-cut tape test result diagram of the electroless copper plating layer in the embodiment of the present invention. The adhesion between the metal pattern prepared by the present invention and the transparent plastic material reaches the ASTM D3359 5B standard, the thickness of the metal copper layer is above 5 μm, and the conductivity reaches 10 7S / m, fully meeting the requirements of industrial applications and achieving technical effects that are completely unexpected to those skilled in the art. Compared with photolithography, ink printing, and laser direct forming technologies, the present invention does not require a mask and can significantly reduce the amount of laser sensitizer used, while significantly improving the laser-induced activation efficiency, having very good economic benefits, a simple process, and being suitable for industrial production applications.

[0055] Finally, it should also be noted that the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, such that a process, method, article or apparatus comprising a series of elements not only includes those elements but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or apparatus.

[0056] Although the preferred embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications to these embodiments once they learn the basic creative concept. Therefore, the appended claims are intended to be construed as including the preferred embodiments and all changes and modifications falling within the scope of the present invention.

[0057] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these modifications and variations.

Claims

1. A method for selectively metallizing a transparent plastic substrate, characterized in that, The method includes the following steps: Step S1: Prepare a laser sensitizer ink by mixing a general laser sensitizer with a solvent, and coat it on one side surface of a transparent plastic substrate by means of blade coating; Step S2: Use laser irradiation to etch the other side surface of the transparent plastic without the coated laser sensitizer ink, so that the laser passes through the plastic material to perform laser-induced activation treatment on the laser sensitizer ink; Step S3: Clean the transparent plastic substrate after the laser-induced activation treatment in Step S2, and rinse off the excess laser sensitizer ink; then carry out electroless copper plating reaction to prepare the required selective metallization pattern.

2. The method for selectively metallizing a transparent plastic substrate as described in claim 1, characterized in that, The general laser sensitizer is any one or more of cupric oxide, cuprous oxide, basic copper phosphate, copper oxalate, basic copper carbonate, copper acetylacetonate, copper nitrate, copper pyrophosphate containing copper element in the molecular structure; the average particle size of the laser sensitizer containing copper element is 30 - 200 nm.

3. The method for selective metallization of a transparent plastic substrate as described in claim 1, characterized in that, The general laser sensitizer is any one or more of antimony tin oxide, zinc oxide, molybdenum oxide, cobalt oxide without copper element in the molecular structure; the average particle size of the laser sensitizer without copper element is 50 - 150 nm.

4. The method for selectively metallizing a transparent plastic substrate as described in claim 1, wherein The solvent is one or more of methanol, ethanol, propanol, tetrahydrofuran, cyclohexane, dichloromethane, water.

5. The method for selectively metallizing a transparent plastic substrate as described in claim 1, characterized in that, The transparent plastic substrate is any one of polyethylene terephthalate, polycarbonate, polymethyl methacrylate, polystyrene, polypropylene, transparent nylon, thermoplastic polyurethane elastomer, silicone rubber, styrene thermoplastic elastomer, polyphenylene sulfide, liquid crystal polymer, cycloolefin copolymer.

6. The method for selectively metallizing a transparent plastic substrate as described in claim 1, characterized in that, The laser is a pulsed laser, the wavelength of the laser is 355 - 1064 nm, the laser frequency is 5 - 100 kHz, the laser power is 1 - 30 W, and the laser scanning speed is 100 - 3000 mm / s.

7. The method for selectively metallizing a transparent plastic substrate as described in claim 1, characterized in that, The conditions for electroless copper plating are as follows: formaldehyde system or sodium hypophosphite system is used as the reducing agent, copper salt provides copper ions, potassium sodium tartrate, sodium ethylenediaminetetraacetate, sodium citrate are used as complexing agents, and sodium hydroxide adjusts the pH value of the copper plating solution; the reaction time of electroless copper plating is 2 - 60 min, the thickness of the electroless copper plating layer is 3 - 15 μm, and the adhesion between the metallic copper layer and the transparent plastic substrate reaches the ASTM D3359 5B standard.

8. The method for selectively metallizing a transparent plastic substrate as described in claim 1, characterized in that, The average particle size of the general laser sensitizer is 5 - 300 nm.

9. The method for selectively metallizing a transparent plastic substrate as described in claim 1, characterized in that, The laser sensitizer ink is composed of the following components by weight percentage: 1% - 90% of the general laser sensitizer and 10% - 90% of the solvent.

10. The method for selectively metallizing a transparent plastic substrate as described in claim 1, wherein The uses of the metallization pattern include conductive metal circuits, decorative graphics, and electric heaters.

Images