Reel-to-reel pretreatment method for chemical plating

Abstract

The invention discloses a roll-to-roll pretreatment method for chemical plating. The roll-to-roll pretreatment method comprises the following steps: S1, carrying out plasma pretreatment on a substrate material; s2, carrying out roll-to-roll coating and grafting; s3, carrying out reel-to-reel seed layer adsorption; s4, carrying out post-treatment on the coiled material; through plasma pretreatment, pollutants on the surface of the material can be efficiently cleaned, the surface of the substrate material can be activated, and hydroxyl groups can be excited, so that compared with the steps of oil removal, water washing, coarsening, acid pickling activation and the like in the traditional chemical plating pretreatment process, the method is more efficient and thorough, the tedious operation steps are reduced, and the production efficiency is improved; according to the method, a coating containing a large number of active groups is coated in a roll-to-roll mode, the coating thickness and the grafting temperature are controlled, the active groups in the coating react with hydroxyl on the surface of a substrate material, stable chemical bonds are formed, and compared with a traditional method, the binding force between a plating layer and the substrate material can be more effectively improved through the method.

Description

Technical Field

[0001] The present invention relates to the technical field of surface modification of materials, and specifically to a roll-to-roll pretreatment method for electroless plating. Background Art

[0002] In fields such as the electronic information industry, coating technology plays a very important role. Coating technology mainly includes electroless plating and electroplating, and electroless plating has attracted much attention due to its applicability to large-size coating technology.

[0003] In the traditional electroless plating process, the modification of the substrate material is a crucial link in the entire electroless plating process, directly determining the success or failure of electroless plating and the quality of the coating. The pretreatment process of traditional electroless plating mainly includes steps such as degreasing, water washing, roughening, pickling and activation. The process is cumbersome, and the activation sites mainly rely on the substrate material to generate, resulting in a limited density of the anchored seed layer, thus affecting the quality of the electroless coating and the strength of the bonding with the substrate. Summary of the Invention

[0004] The purpose of the present invention is to provide a roll-to-roll pretreatment method for electroless plating to solve the problems raised in the above background art.

[0005] To achieve the above purpose, the present invention provides the following technical solution: A roll-to-roll pretreatment method for electroless plating, the method comprising the following steps:

[0006] S1: Plasma pretreatment of the substrate material: A plasma device is arranged at the front end of the roll-to-roll pretreatment equipment for cleaning material contaminants and activation treatment, removing the contaminants on the material surface, and simultaneously exciting the hydroxyl groups on the surface of the substrate material;

[0007] S2: Roll-to-roll coating application and grafting: A coating containing a large number of active groups is applied by roll-to-roll coating. The coating thickness is controlled by the distance between the rollers, and the coating thickness is 50 nm to 1 μm. At the same time, the grafting temperature is controlled at 50 - 90°C, and a photoinitiator is used to initiate the reaction of the active groups in the coating, so that the active groups in the coating react with the hydroxyl groups on the material surface;

[0008] Roll-to-roll coating includes a coating device, which includes a coating supply tank. Intersection slots are opened on both sides of the coating supply tank. A substrate is inserted through the coating supply tank, and the substrate passes through the intersection slots. An inlet roller and a take-up roller are respectively arranged on both sides of the substrate. A first transmission shaft is rotatably connected to the coating supply tank through a bearing, and a first coating roller is arranged on the first transmission shaft. Support plates are arranged on both sides of the coating supply tank. A transmission screw is rotatably connected to the support plate. The transmission screw is of a double-screw structure with opposite thread helix directions. Slide seats are arranged on both sides of the transmission screw, and the slide seats are connected to the transmission screw through internal and external threads. A guide rod is arranged between the two support plates. One end of the guide rod passes through the slide seat. A connecting rod is hinged to the bottom of the slide seat. The ends of the two connecting rods are hinged to a storage box. An installation plate is arranged at one end of the storage box. A discharge port is opened at the bottom of the storage box, and the discharge port is directly opposite to the second coating roller. A fixing block is arranged at the bottom of the storage box. A second transmission shaft is rotatably connected between the two fixing blocks through a bearing, and a second coating roller is arranged on the second transmission shaft. The substrate is located between the second coating roller and the first coating roller. A connecting pipe is inserted into the storage box. A support block is arranged inside the support plate. One end of the connecting pipe passes through the support block and extends into the interior of the coating supply tank. A suction pump is arranged on the connecting pipe;

[0009] S3: Roll-to-roll seed layer adsorption: The pre-treatment coating and the seed layer adsorption are carried out separately;

[0010] S4: Rolled material post-treatment: By surface laminating, the laminating temperature is controlled at 80 - 110 °C.

[0011] Preferably, the plasma power is 500 - 3000 w.

[0012] Preferably, the humidity is controlled above 30%.

[0013] Preferably, the coating material is a polymer or macromolecule with more active groups.

[0014] Preferably, the seed layer is noble metals such as Ag and Pd.

[0015] Preferably, the temperature during the adsorption process is controlled at 50 - 90 °C.

[0016] Preferably, a surfactant is added to the seed liquid to improve the spreading ability of the seed liquid.

[0017] Preferably, the noble metal concentration in the seed liquid is 0.1% - 0.5%.

[0018] Preferably, the protective film uses a non-sticky release film.

[0019] Preferably, the material for laminating uses an aqueous adhesive.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0021] 1. Through plasma pretreatment, the present invention can efficiently clean the pollutants on the material surface and activate the surface of the substrate material, exciting hydroxyl groups, which is more efficient and thorough than the steps of degreasing, water washing, roughening, pickling activation, etc. in the traditional electroless plating pretreatment process, reducing cumbersome operation steps and improving production efficiency.

[0022] 2. By roll-to-roll coating a coating containing a large number of active groups and controlling the coating thickness and grafting temperature, the present invention enables the active groups in the coating to react with the hydroxyl groups on the surface of the substrate material to form stable chemical bonds. This method can more effectively improve the bonding force between the coating and the substrate material than the traditional method.

[0023] 3. By separately performing the pretreatment coating application and the seed layer adsorption, the present invention helps to increase the density of the seed layer, ensuring the uniform distribution of the seed layer on the surface of the substrate material, thereby improving the quality of the subsequent electroless coating. By controlling the temperature of the adsorption process and adding a surfactant, the spreading ability and adsorption efficiency of the seed solution are improved, further optimizing the adsorption effect of the seed layer.

[0024] 4. The double-sided simultaneous coating design of the present invention allows the substrate to complete the coating of both sides when passing through the device once, significantly improving production efficiency. Through the precise drive screw and slide system, the distance between the coating rollers can be adjusted to ensure the uniformity of the coating thickness and improve product quality. The double-screw structure and guide rod of the drive screw enable the adjustment of the distance between the coating rollers to adapt to different substrate thicknesses and coating requirements, increasing the flexibility of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the roll-to-roll pretreatment for electroless plating of the present invention.

[0026] Figure 2 It is a schematic diagram of the structure of the roll-to-roll coating device of the present invention.

[0027] Figure 3 It is a schematic diagram of the adjustment of the roll-to-roll coating device of the present invention.

[0028] Figure 4 It is a schematic diagram of the structure of the coating supply tank of the present invention.

[0029] Figure 5 It is a schematic diagram of the bottom of the storage box of the present invention.

[0030] In the figure: coating supply tank 1; insertion slot 11; base material 2; first coating roller 3; first transmission shaft 31; support plate 4; transmission screw 5; sliding seat 6; guide rod 61; connecting rod 7; storage box 8; mounting plate 81; discharge port 82; fixing block 9; second coating roller 91; second transmission shaft 92; support block 10; connecting pipe 101; suction pump 102. Detailed implementation manner

[0031] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0032] Please refer to Figures 1 to 5 , the present invention provides a technical solution: a roll-to-roll pretreatment method for electroless plating, the method comprising the following steps:

[0033] S1: Plasma pretreatment of the base material: Select a PET base material, and set a plasma device at the front end of the roll-to-roll pretreatment equipment for cleaning material contaminants and activation treatment, removing the material surface contaminants, and at the same time exciting the hydroxyl groups on the surface of the base material. The plasma power is 500 - 3000w, the treatment speed is 6 - 15m / min, and a humidity sensor is used to monitor the humidity in the treatment process in real time. During the treatment process, the humidity is controlled above 30% to facilitate the generation of surface hydroxyl groups;

[0034] S2: Roll-to-roll coating application and grafting: Apply a coating containing a large number of active groups through roll-to-roll coating. The coating thickness is controlled by the distance between the rollers, and the coating thickness is 50nm to 1μm. This is the optimal thickness range verified by experiments, which can not only ensure the density of active groups in the coating, but also ensure sufficient contact area between the coating and the base material, thereby improving the success rate of grafting;

[0035] The coating material uses polymers or macromolecules with more active groups, such as polyethylene glycol, polyvinyl alcohol, alkyl amides, etc. At the same time, the grafting temperature is controlled at 50 - 90°C, and an ultraviolet lamp is used as the light source to activate the photoinitiator. The photoinitiator is used to initiate the reaction of active groups in the coating. The photoinitiator can generate free radicals under light of a specific wavelength, and these free radicals can activate the active groups in the coating and promote cross-linking reactions with the hydroxyl groups on the surface of the base material;

[0036] Roll-to-roll coating includes a coating device, which includes a paint supply tank 1. The paint supply tank 1 stores paint and provides paint for the coating process. Interpenetrating grooves 11 are provided on both sides of the paint supply tank 1. A substrate 2 is inserted through the paint supply tank 1, and the substrate 2 passes through the interpenetrating grooves 11. Feed rollers and take-up rollers are respectively arranged on both sides of the substrate 2 (not shown in the drawings). Driven by the feed rollers and take-up rollers, the substrate continuously passes through the paint supply tank for coating. The feed rollers send the substrate into the interpenetrating grooves, and the take-up rollers collect the coated substrate.

[0037] A first transmission shaft 31 is rotatably connected to the paint supply tank 1 through a bearing. A first motor is installed at the end of the first transmission shaft 31, and a first coating roller 3 is fixedly sleeved on the first transmission shaft 31.

[0038] Support plates 4 are fixed on both sides of the paint supply tank 1. A transmission screw 5 is rotatably connected to the support plates 4. The transmission screw 5 has a double-screw structure with opposite thread directions. Slide seats 6 are arranged on both sides of the transmission screw 5. The slide seats 6 are connected with the transmission screw 5 by internal and external threads. A guide rod 61 is fixed between the two support plates 4, and one end of the guide rod 61 passes through the slide seat 6.

[0039] A connecting rod 7 is hinged to the bottom of the slide seat 6. The ends of the two connecting rods 7 are hinged to a storage box 8. One end of the storage box 8 is fixed with a mounting plate 81 by bolts. A discharge port 82 is opened at the bottom of the storage box 8, and the discharge port 82 is directly opposite to the second coating roller 91. The paint in the storage box 8 flows to the coating roller through the discharge port 82.

[0040] A fixed block 9 is connected to the bottom of the storage box 8. A second transmission shaft 92 is rotatably connected between the two fixed blocks 9 through a bearing. A second motor is installed at the end of the second transmission shaft 92, and a second coating roller 91 is fixedly sleeved on the second transmission shaft 92. The substrate 2 is located between the second coating roller 91 and the first coating roller 3. The second motor drives the coating roller to rotate through the transmission shaft and works in cooperation with the first coating roller 3 to achieve double-sided coating.

[0041] A connecting pipe 101 is inserted into the storage box 8. A support block 10 is fixedly connected to the inner side of the support plate 4. One end of the connecting pipe 101 passes through the support block 10 and extends into the interior of the paint supply tank 1. A suction pump 102 is installed on the connecting pipe 101. The suction pump 102 sucks the paint from the paint supply tank 1 to the storage box 8 through the connecting pipe 101 to ensure the continuous supply of paint.

[0042] The substrate enters the coating supply tank 1 driven by the feeding roller, passes through the insertion slot 11, the first coating roller 3 and the second coating roller 91 rotate driven by the motor, and the coating is evenly applied to both sides of the substrate. The coating is sucked from the coating supply tank 1 to the storage box 8 through the connecting pipe 101 and flows to the second coating roller 91 through the discharge port 82. The sliding seat 6 and the transmission screw 5 allow the operator to adjust the distance between the coating rollers to control the coating thickness. Finally, the coated substrate is collected by the take-up roller, completing the entire roll-to-roll double-sided coating process.

[0043] S3: Roll-to-roll seed layer adsorption: Separating the pre-treatment coating application and the seed layer adsorption is mainly to increase the density of the seed layer on the outermost surface of the pre-treatment, improve the quality of the subsequent electroless plating layer, and also further reduce the consumption of the precious metal seed layer. The seed layer is precious metals such as Ag and Pd. The temperature during the adsorption process is controlled at 50 - 90 °C. On the one hand, it accelerates the adsorption kinetic process, and on the other hand, it dries the pre-treatment layer. A surfactant is added to the seed solution to improve the spreading ability of the seed solution. The precious metal concentration in the seed solution is 0.1% - 0.5%;

[0044] S4: Post-treatment of the rolled material: Through surface laminating, the laminating temperature is controlled at 80 - 110 °C. The protective film uses a non-sticky release film, and the laminating material uses a water-based adhesive to reduce the impact on the environment.

[0045] Example 1:

[0046] A roll-to-roll pre-treatment method for electroless plating, the method comprising the following steps:

[0047] S11: Plasma pre-treatment of the substrate material: Selecting a PET substrate material, using a roll-to-roll pre-treatment device, with a plasma device set at the front end, a power of 2000 w, a processing speed of 10 m / min, and during the processing, the humidity is controlled at 40%;

[0048] S12: Roll-to-roll coating application and grafting: Using a polymer coating material containing a large number of active groups, the coating thickness is 100 nm, controlled by the distance between the rollers, the grafting temperature is controlled at 70 °C, and a photoinitiator is used to initiate the reaction of the active groups in the coating;

[0049] S13: Roll-to-roll seed layer adsorption: Immersing the pretreated PET material in a solution containing an Ag seed solution, the Ag concentration in the seed solution is 0.2%, and the temperature during the adsorption process is controlled at 70 °C. A surfactant is added to the seed solution to improve the spreading ability of the seed solution;

[0050] S14: Post-treatment of the rolled material: Using a non-sticky release film as the protective film, the laminating temperature is controlled at 90 °C. The laminating material uses a water-based adhesive.

[0051] Example 2:

[0052] S21: Roll-to-roll coating and grafting: Use a polymer coating material containing a large number of active groups, with a coating thickness of 100 nm, controlled by the distance between rollers, the grafting temperature is controlled at 70 °C, and a photoinitiator is used to initiate the reaction of active groups in the coating;

[0053] S22: Roll-to-roll seed layer adsorption: Immerse the pretreated PET material in a solution containing Ag seed solution, with the Ag concentration in the seed solution being 0.2%, and the adsorption process temperature is controlled at 70 °C. A surfactant is added to the seed solution to improve the spreading ability of the seed solution;

[0054] S23: Post-treatment of the rolled material: Use a non-sticky release film as the protective film, and the film laminating temperature is controlled at 90 °C. The material for film lamination is a water-based adhesive.

[0055] Compared with Example 1, the results show that for the PET material without plasma pretreatment, the surface coating layer is uneven, the adhesion of the coating layer is poor, and the conductivity is reduced.

[0056] Example 3:

[0057] S31: Plasma pretreatment of the substrate material: Select a PET substrate material, use a roll-to-roll pretreatment device, with a plasma device set at the front end, a power of 2000 w, a processing speed of 10 m / min, and during the processing, the humidity is controlled at 40%;

[0058] S32: Roll-to-roll coating and grafting: Use a polymer coating material containing a large number of active groups, with a coating thickness of 500 nm, controlled by the distance between rollers, the grafting temperature is controlled at 70 °C, and a photoinitiator is used to initiate the reaction of active groups in the coating;

[0059] S33: Roll-to-roll seed layer adsorption: Immerse the pretreated PET material in a solution containing Ag seed solution, with the Ag concentration in the seed solution being 0.2%, and the adsorption process temperature is controlled at 70 °C. A surfactant is added to the seed solution to improve the spreading ability of the seed solution;

[0060] S34: Post-treatment of the rolled material: Use a non-sticky release film as the protective film, and the film laminating temperature is controlled at 90 °C. The material for film lamination is a water-based adhesive.

[0061] Compared with Example 1, the results show that when the coating thickness is 500 nm, the adhesion of the coating layer is further improved, but the conductivity decreases slightly.

[0062] Example 4:

[0063] S41: Plasma pretreatment of the substrate material: Select a PET substrate material and use a roll-to-roll pretreatment device. A plasma device is set at the front end with a power of 2000 w and a processing speed of 10 m / min. During the processing, the humidity is controlled at 40%;

[0064] S42: Roll-to-roll coating and grafting: Use a polymer coating material containing a large number of active groups. The coating thickness is 500 nm, which is controlled by the distance between the rollers. The grafting temperature is controlled at 70 °C, and a photoinitiator is used to initiate the reaction of the active groups in the coating;

[0065] S33: Roll-to-roll seed layer adsorption: Immerse the pretreated PET material in a solution containing an Ag seed solution. The Ag concentration in the seed solution is 0.3%. The temperature during the adsorption process is controlled at 70 °C. A surfactant is added to the seed solution to improve the spreading ability of the seed solution;

[0066] S44: Post-treatment of the rolled material: Use a non-sticky release film as the protective film, and the laminating temperature is controlled at 90 °C. The material for laminating is a water-based adhesive.

[0067] Compared with Example 1, the results show that when the Ag concentration in the seed solution is 0.3%, both the coating uniformity and the bonding strength are improved.

[0068] In summary, through plasma pretreatment, the present invention can efficiently clean the pollutants on the material surface and activate the surface of the substrate material, stimulating hydroxyl groups, which is more efficient and thorough than the steps of degreasing, water washing, roughening, pickling and activation in the traditional electroless plating pretreatment process, reducing cumbersome operation steps and improving production efficiency; by roll-to-roll coating a coating containing a large number of active groups and controlling the coating thickness and grafting temperature, the active groups in the coating react with the hydroxyl groups on the surface of the substrate material to form stable chemical bonds. This method can more effectively improve the bonding strength between the coating and the substrate material than the traditional method; by separating the pretreatment coating and the seed layer adsorption, it helps to increase the density of the seed layer, ensure the uniform distribution of the seed layer on the surface of the substrate material, thereby improving the quality of the subsequent electroless coating. By controlling the adsorption process temperature and adding a surfactant, the spreading ability and adsorption efficiency of the seed solution are improved, further optimizing the adsorption effect of the seed layer; due to the increase in the density of the seed layer, the usage amount of precious metals can be reduced, the production cost can be lowered, while maintaining the high quality of the coating, and non-sticky release film and water-based adhesive are used for post-treatment to reduce the impact on the environment.

[0069] Although the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made therein without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A roll-to-roll pre-treatment method for chemical plating, characterized in that: The method comprises the following steps: S1: Plasma pre-treatment of substrate materials: A plasma device is set at the front end of the roll-to-roll pre-treatment equipment to clean material contaminants and activate the material, remove contaminants on the material surface, and stimulate hydroxyl groups on the surface of the substrate material; S2: Roll-to-roll coating and grafting: A coating containing a large number of active groups is applied by roll-to-roll coating. The coating thickness is controlled by the distance between the rollers. The coating thickness is 50nm to 1μm. At the same time, the grafting temperature is controlled at 50-90℃. A photoinitiator is used to initiate the reaction of the active groups in the coating, so that the active groups in the coating react with the hydroxyl groups on the surface of the material. The roll-to-roll coating comprises a coating coating device, which comprises a coating supply pool (1), both sides of the coating supply pool (1) are provided with through slots (11), a substrate (2) is inserted into the coating supply pool (1), and the substrate (2) is arranged through the through slots (11), a first transmission shaft (31) is rotatably connected to the coating supply pool (1) through a bearing, a first coating roller (3) is arranged on the first transmission shaft (31), support plates (4) are arranged on both sides of the coating supply pool (1), a transmission screw (5) is rotatably connected to the support plate (4), the transmission screw (5) is a double screw structure, and the thread rotation direction is opposite, a slide seat (6) is arranged on both sides of the transmission screw (5), the slide seat (6) and the transmission screw (5) are connected by internal and external threads, a guide rod (61) is arranged between the two support plates (4), one end of the guide rod (61) is arranged through the slide seat (6), and the slide seat The bottom of (6) is hinged with a connecting rod (7), the ends of the two connecting rods (7) are hinged with a material storage box (8), one end of the material storage box (8) is provided with a mounting plate (81), the bottom of the material storage box (8) is provided with a discharge port (82), the discharge port (82) is arranged opposite to the second coating roller (91), the bottom of the material storage box (8) is provided with a fixing block (9), the two fixing blocks (9) are rotatably connected with a second transmission shaft (92) through a bearing, the second coating roller (91) is arranged on the second transmission shaft (92), the substrate (2) is located between the second coating roller (91) and the first coating roller (3), a connecting pipe (101) is inserted into the material storage box (8), a supporting block (10) is arranged on the inner side of the supporting plate (4), one end of the connecting pipe (101) passes through the supporting block (10) and extends to the inside of the coating supply tank (1), and a suction pump (102) is arranged on the connecting pipe (101); S3: Roll-to-roll seed layer adsorption: pretreatment coating application and seed layer adsorption are performed separately; S4: Coil post-processing: surface coating, the coating temperature is controlled at 80-110℃.

2. The roll-to-roll pre-treatment method for chemical plating according to claim 1, characterized in that: The plasma power is 500-3000w.

3. The roll-to-roll pre-treatment method for chemical plating according to claim 1, characterized in that: The humidity is controlled at above 30%.

4. The roll-to-roll pre-treatment method for chemical plating according to claim 1, characterized in that: The coating material is a polymer or macromolecule with more active groups.

5. The roll-to-roll pre-treatment method for chemical plating according to claim 1, characterized in that: The seed layer is made of precious metals such as Ag and Pd.

6. The roll-to-roll pre-treatment method for chemical plating according to claim 1, characterized in that: The temperature of the adsorption process is controlled at 50-90°C.

7. The roll-to-roll pre-treatment method for chemical plating according to claim 1, characterized in that: A surfactant is added to the seed liquid to improve the spreading ability of the seed liquid.

8. The roll-to-roll pre-treatment method for chemical plating according to claim 5, characterized in that: The noble metal concentration of the seed solution is 0.1%-0.5%.

9. The roll-to-roll pre-treatment method for chemical plating according to claim 1, characterized in that: The protective film is a non-sticky release film.

10. The roll-to-roll pre-treatment method for chemical plating according to claim 1, characterized in that: The laminating material is a water-based adhesive.

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