KR20220079745A - Method for manufacturing the rf filter made by pps injection product - Google Patents

Abstract

The present invention relates to a method for manufacturing an RF filter using a PPS resin injection having excellent propagation characteristics by forming a plating layer on the surface of an injection molding made of PPS resin, which is an engineering plastic, without using nickel. The manufacturing method includes the steps of: 1) removing the skin layer on the surface of the PPS resin injection product; 2) expanding the interstitial pores on the surface of the PPS resin injection molding; 3) removing the glass fibers on the surface of the PPS resin injection molding through the interstitial pores and improving the surface roughness; 4) adsorbing a catalyst metal to enable electroless plating on the surface of the PPS resin injection molding; 5) plating the conductive metal on the PPS resin injection molded product to which the catalyst metal has been adsorbed in step 4).

Description

Rf filter manufacturing method using PPS resin injection molding {METHOD FOR MANUFACTURING THE RF FILTER MADE BY PPS INJECTION PRODUCT}

The present invention relates to a method for manufacturing an RF filter using a PPS resin injection molded product having excellent propagation characteristics by forming a plating layer on the surface of the injection molding product made of PPS resin, which is an engineering plastic, without using nickel.

Recently used antennas for wireless communication devices or antennas or RF filters for wireless communication repeaters are mainly provided in a minimized volume by plating conductors with excellent radio and frequency reception/transmission properties on the surface of accessories that make up products. At this time, the material of the terminal body or accessories is mainly injection molded into a predetermined shape using polycarbonate (PC, polycarbonate) or polyphenylene sulfide (PPS). As a made resin, it is hard like metal and resists acid and heat well, so it is used to manufacture machine parts and household products instead of metal. It will be used to manufacture electrical parts and the like.

Due to the characteristics of such PPS, direct plating on the surface was impossible. Therefore, conventionally, the double injection method has been used as a method for plating the surface. However, this double injection method requires a large number of molds, increasing the manufacturing cost. In addition to the fact that the work process is very complicated, there was a problem that lowered the efficiency and productivity of the work. There was also a problem that the defective rate of the product was increased and there was a limit in the field of application.

The technical problem to be solved by the present invention is to provide a method for manufacturing an RF filter using a PPS resin injection having excellent propagation characteristics by forming a plating layer on the surface of the injection molding made of PPS resin, which is an engineering plastic, without using nickel.

RF filter manufacturing method using a PPS resin injection molding according to the present invention for solving the above technical problem, 1) removing the skin layer on the surface of the PPS resin injection molding; 2) expanding the interstitial pores on the surface of the PPS resin injection molding; 3) removing the glass fibers on the surface of the PPS resin injection molding through the interstitial pores and improving the surface roughness; 4) adsorbing a catalyst metal to enable electroless plating on the surface of the PPS resin injection product; 5) plating the conductive metal on the PPS resin injection molded product to which the catalyst metal has been adsorbed in step 4).

And in the present invention, step 5) includes: a) improving adhesion by precipitating copper (Cu) on the catalyst metal; b) uniformly plating copper to a predetermined thickness on the surface of the PPS resin injection molding; c) peeling the copper plating; d) copper plating the PPS resin injection product from which the copper plating has been peeled off in step c) is preferably divided into sub-steps.

In addition, in step c) in the present invention, it is preferable to remove the remainder except for the anchor formed in the gap pore during copper plating on the surface of the PPS resin injection molding using a nitric acid solution.

In addition, in the present invention, step c) is preferably carried out for 10 minutes at a temperature of 30 ~ 50 ℃ using a 65 ~ 68% nitric acid solution.

In addition, in the present invention, in step d), it is preferable to sequentially repeat steps 4) and 5) twice or more.

According to the RF filter manufacturing method using the PPS resin injection molding of the present invention, a copper plating layer is formed on the surface of the injection product made of PPS resin, which is a PPS resin injection molding engineering plastic, without using nickel. effect can be achieved.

1 is a partial cross-sectional view schematically showing the internal structure of a PPS resin injection product.
2 is a flowchart of a method for manufacturing an RF filter using a PPS resin injection molding according to an embodiment of the present invention.
3 is a detailed process diagram of a step of expanding interstitial pores according to an embodiment of the present invention.
4 is a detailed process diagram of the glass fiber removal / surface roughness improvement step according to an embodiment of the present invention.
5 is a detailed process diagram of a catalyst metal adsorption step according to an embodiment of the present invention.
6 is a detailed process diagram of a conductive metal plating step according to an embodiment of the present invention.

Hereinafter, specific embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The RF filter manufacturing method using the PPS resin injection molding according to the present embodiment starts with the skin layer removing step (S100), as shown in FIG. 2 . In this step (S100), by using an acidic skin layer removal solution, the elastomer and rubber forming the skin layer 10 on the surface of the PPS resin injection-molded product 1 are removed to remove the surface of the PPS resin injection-molded product. Expose interstitial pores and additives.

As shown in FIG. 1, the PPS (PolyPhenylene Sulfide) resin injection product 1 has a skin layer 10 formed on the surface, a core layer 30 is formed therein, and the skin layer 10 and It has a cross-sectional structure in which the middle layer 20 is formed between the core layers 30 . Here, the skin layer 10 is made of an elastomer, rubber, oil, etc. administered during the injection process. In addition, the middle layer 20 has a structure in which PPS crystals and an elastic polymer are mixed, and the core layer 30 is a layer made of only PPS crystals.

Therefore, in the skin layer removal step (S100), specifically, the PPS resin injection product 1 is immersed for 50 to 70 minutes at a temperature of 70 to 75° C. using a skin layer removal solution having a concentration of 35 to 37% hydrochloric acid (HCl). to remove the elastomer, rubber, and oil constituting the skin layer 10 .

Next, as shown in FIG. 2 , the step of expanding the interstitial pores ( S200 ) is performed. In this step (S200), the cracks on the surface of the PPS resin injection product 1 from which the skin layer 10 has been removed through the previous step (S100) are expanded.

In this embodiment, it is preferable that the interstitial pore expansion step (S200) is divided into sub-steps of the ultrasonic degreasing step (S210) and the interstitial pore expansion step (S220) as specifically illustrated in FIG. 3 . First, in the ultrasonic degreasing step (S210), a commercially available alkaline degreasing agent is used to remove the residual chemicals remaining on the surface of the PPS resin injection product (1) in the skin layer removal step (S100), and at the same time, impurities are physically removed using ultrasonic waves. removed with

Next, in the interstitial pore expansion step (S220), as shown in FIG. 3 , the PPS resin injection-molded product 1 is used with a sodium hydroxide (NaOH) solution to expand the interstitial pores (crack) on the surface of the PPS resin injection-molded product, and , Expose the glass fiber added as an additive to the PPS resin injection product. This step (S220) is preferably carried out by immersing the PPS resin injection in sodium hydroxide solution at a temperature of 90 ~ 95 ℃ for 50 ~ 70 minutes.

Next, as shown in FIG. 2 , the glass fiber removal and surface roughness improvement step ( S300 ) is performed. In this step (S300), the glass fiber on the surface of the PPS resin injection product 1 is removed through the interstitial pores expanded in the previous step (S200), and the surface roughness is improved.

In this embodiment, as specifically shown in FIG. 4, this step (S300) is preferably divided into small steps of the ultrasonic degreasing step (S310) and the additive removal and surface roughness improvement step (S320). First, in the ultrasonic desorption step (S310), the residual chemicals remaining on the surface of the PPS resin injection product 1 in the gap pore expansion step (S200) are removed using a commercially available alkali degreasing agent, and impurities are physically removed using ultrasonic waves. Remove.

Next, in the additive removal and surface roughness improvement step (S320), as shown in FIG. 4, in the gap pore expansion step (S200) using ammonium fluoride (NH ₄ F) to the surface of the PPS resin injection product (1). The surface roughness is improved by removing the additives and minerals including the exposed glass fibers and at the same time improving the surface roughness of the PPS resin molded product 1 .

Next, as shown in FIG. 2 , a physical etching step ( S400 ) is performed. In this step (S400), the rear surface of the PPS resin injection molded product 1 is physically etched, and specifically, the surface of the PPS resin injection molding product 1 is physically etched by irradiating a laser to the rear surface of the PPS resin injection molding product 1 . will do When pores are formed by physically etching the back side of the PPS resin injection molding in this way, the gas inside the injection molding is continuously discharged through these pores during the plating process, and the gas is discharged only in a specific direction of the product after the plating process. There is an advantage in that there is no problem of plating damage or deterioration of properties in the course of use.

Here, the 'rear' of the PPS resin injection molding refers to a surface on which a gate is formed during the injection process of the PPS resin injection molding, and this surface forms the rear surface when the product is completed. In addition, in this embodiment, it is more preferable to physically etch the gate portion and the periphery of the back surface of the PPS resin injection molding using a diode laser having a wavelength of 800 to 1100 nm.

On the other hand, in the PPS resin injection molding method according to the present embodiment, after performing the physical etching step (S400), it is preferable that the step of cleaning the PPS resin injection molding using a commercially available alkali degreasing agent and ultrasonic waves is further performed.

On the other hand, in the PPS resin injection molding method according to this embodiment, before performing the physical etching step (S400), the PPS resin injection molding 1 is put into a high-temperature dryer set at a temperature of 200 ~ 240 ° C. For 3 ~ 5 hours Annealing by drying may be further performed.

Next, as shown in FIG. 2, the catalyst metal adsorption step (S500) proceeds. In this step (S500), the catalyst metal is adsorbed on the surface of the PPS resin injection product 1 to enable electroless plating. The PPS resin injection product is a product molded by injection of a non-conductive synthetic resin, and electroless plating cannot be directly applied to the surface thereof.

Therefore, in this embodiment, the catalyst metal compound is adsorbed into the interstitial pores of the surface of the PPS resin injection molding to enable electroless plating by immersing the PPS resin injection molded product in a catalyst adsorption solution.

In this embodiment, as specifically shown in FIG. 5, the catalytic metal adsorption step (S500) is preferably divided into substeps of the tin chloride adsorption step (S510) and the palladium substitution precipitation step (S520). First, the tin chloride adsorption step (S510) is a step of immersing the PPS resin injection molded product in a first activation solution containing divalent tin chloride (SnCl ₂ ) to adsorb the tin chloride into the uneven and interstitial pores on the surface of the PPS resin injection molding product. to be.

At this time, the first activation solution is preferably a divalent tin chloride (SnCl ₂ ) solution and a mixed solution of hydrochloric acid, and in the tin chloride adsorption step (S510), the material adsorbed into the interstitial pores of the PPS resin injection product 1 is Divalent tin chloride (SnCl ₂ ) is reduced to stable tetravalent tin chloride (SnCl ₄ ).

Next, in the palladium substitution precipitation step (S520), as shown in FIG. 5 , the PPS resin injection product (1) in which tin chloride is adsorbed to the second activation solution containing palladium (Pd) in the previous step (S510) It is a step of substituting and precipitating palladium in the tin chloride on the surface of the PPS resin injection by depositing.

In this step (S520), the second activation solution is preferably a mixed solution of palladium solution and sulfuric acid, and copper ions are substituted on the palladium metal thus formed in a subsequent plating process to start copper plating.

Meanwhile, in the PPS resin injection molding method according to this embodiment, before the catalyst metal adsorption step (S500) is performed, the PPS resin injection molding is immersed in a hydrochloric acid (HCl) solution so that the surface of the PPS resin injection molding is well coated with the first activation solution. It is preferable that the step of coating so as to penetrate further proceeds.

Next, as shown in FIG. 2 , a conductive metal plating step S600 is performed. In this step (S600), the conductive metal is plated with the catalyst metal as an anchor on the surface of the PPS resin injection product 1 on which the palladium metal is adsorbed inside the interstitial pores in the catalyst metal adsorption step (S500).

In this embodiment, the conductive metal plating step (S600) is specifically performed, as shown in FIG. 6, of the copper strike step (S610), the copper build step (S620), the copper peeling step (S630) and the copper plating (S640). It is preferable to proceed in small steps. First, in the copper strike step (S610), copper (Cu) is deposited on palladium, which is the catalyst metal, to improve adhesion, and in this step, copper is thinly raised for a short time of 1 to 5 minutes. That is, in this step (S610), copper ions are substituted on the palladium metal adsorbed in the interstitial pores of the PPS resin injection product in the catalyst metal adsorption step.

Next, the copper build step (S620) is a step of uniformly and thickly plating copper to a predetermined thickness on the surface of the PPS resin injection product on which copper is thinly plated in the previous step (S610). In this step (S620), it is preferable to use a commercially available electroless copper plating solution to plate copper to a thickness of 6 μm or more on the surface of the PPS resin injection product.

Next, the copper stripping step (S630) is a step of peeling the copper plating formed in the previous step (S620). In the present embodiment, this step (S630) is performed in a manner of removing the remainder except for the anchor formed in the interstitial pores during the copper plating of the surface of the PPS resin injection molding 1 using a nitric acid solution.

To this end, it is preferable that the copper stripping step (S630) be performed for 10 minutes at a temperature of 30 to 50° C. using a 65 to 68% nitric acid solution specifically, as it is possible to peel off the remaining copper plating layer leaving only the anchor formed in the interstitial pores. do.

Next, as shown in FIG. 6 , the copper plating step (S640) of the PPS resin injection product from which the copper plating has been peeled off in the copper stripping step (S630) is performed again. In this embodiment, it is preferable that this step (S640) is specifically performed in such a way that the catalyst metal adsorption step (S500), the copper strike step (S610), and the copper build step (S620) are sequentially performed.

If the copper plating layer is formed by repeating the copper plating and peeling in this way, the anchors formed in the gap pores are evenly distributed on the PPS resin injection product, thereby improving the plating distribution.

Of course, these copper plating and copper peeling processes may be repeated two or more times if necessary.

1: PPS (PolyPhenylene Sulfide) resin injection
10: skin layer 20: middle layer
30: core layer

Claims (5)

1) removing the skin layer on the surface of the PPS resin injection molding;
2) expanding the interstitial pores on the surface of the PPS resin injection molding;
3) removing the glass fibers on the surface of the PPS resin injection molding through the interstitial pores and improving the surface roughness;
4) adsorbing a catalyst metal to enable electroless plating on the surface of the PPS resin injection product;
5) A method of manufacturing an RF filter using a PPS resin injection molded product comprising; plating a conductive metal on the PPS resin injection molded product to which the catalyst metal has been adsorbed in step 4). According to claim 1, wherein step 5),
a) depositing copper (Cu) on the catalyst metal to improve adhesion;
b) uniformly plating copper to a predetermined thickness on the surface of the PPS resin injection molding;
c) peeling the copper plating;
d) copper plating the PPS resin injection molded product from which the copper plating has been removed in step c); The method of claim 2, wherein in step c),
A method for manufacturing an RF filter using a PPS resin molded product, characterized in that removing the rest except for the anchor formed in the interstitial pores during copper plating on the surface of the PPS resin molded product using a nitric acid solution. The method of claim 2, wherein step c) comprises:
A method of manufacturing an RF filter using a PPS resin injection, characterized in that it is performed for 10 minutes at a temperature of 30 to 50° C. using a 65 to 68% nitric acid solution. The method of claim 2, wherein step d) comprises:
A method for manufacturing an RF filter using a PPS resin injection, characterized in that the steps 4) and 5) are sequentially repeated two or more times.

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