CN112134007B - Method for preparing 5G antenna oscillator conductive pattern through selective thickening and differential etching - Google Patents

Abstract

The invention belongs to the technical field of conductive pattern manufacturing, and particularly relates to a method for preparing a 5G antenna oscillator conductive pattern by selective thickening and differential etching, which comprises the steps of firstly, selectively thickening the surface of an initial conductive layer part to obtain a thickened conductive layer with uneven thickness, then, differentially etching all surfaces of the thickened conductive layer with equal thickness until all first metal layers are removed, and preparing a formed three-dimensional conductive pattern at one time; meanwhile, the second metal layer is prepared through the positive phase insulating layer, so that the initial conducting layer can be thickened, the barrier line does not need to be manufactured, the conducting circuit is high in accuracy, the conducting circuit only needs to be thickened along the line trend region of the conducting circuit, the conducting layer is not needed to be removed in a large-area and large-volume mode subsequently, the cost is saved, and the efficiency is improved.

Description

Method for preparing 5G antenna oscillator conductive pattern through selective thickening and differential etching

Technical Field

The invention belongs to the technical field of conductive pattern manufacturing, and particularly relates to a method for preparing a 5G antenna oscillator conductive pattern through selective thickening and differential etching.

Background

The fifth Generation mobile communication technology (5th-Generation, abbreviated as 5G) is the latest Generation cellular mobile communication technology, and its peak theoretical transmission speed can reach tens of Gb per second, which is hundreds of times of the transmission speed of 4G network. The oscillator is the most important functional component in the antenna, has the functions of guiding and amplifying electromagnetic waves, and guarantees the reliability, stability and durability of the antenna performance through the structural design, the manufacturing method and the assembly process. The traditional antenna oscillator manufacturing process adopts the mode of die-casting and molding metal materials (aluminum alloy or zinc alloy) or combining sheet metal parts, plastic fixing parts and conductive circuits.

At present, the conducting circuit of the 5G antenna element is mainly manufactured by two main processes of layer reduction and layer addition.

Wherein, the layer reduction process comprises the following steps: (1) based on PCB single-side 'layer reduction' process: a dry film is pasted on a PCB and a conductive pattern is formed through exposure and etching, but the method can only prepare a single surface every time, and the three-dimensional conductive pattern of the 5G antenna oscillator cannot be prepared and formed at one time; (2) based on the integral 'layer reduction' process: the method comprises the steps of carrying out chemical plating and electroplating on the whole 5G antenna oscillator to form a metal layer with required thickness, removing the photosensitive resist of a negative phase pattern by using laser, carrying out chemical etching to remove the large-area negative phase metal layer, and finally removing the residual photosensitive resist on a positive phase pattern to obtain a required three-dimensional conductive pattern.

The layer-adding process comprises the following steps: (1) based on the laser direct structuring technology: coating a metal compound layer on the surface layer 3D of the vibrator plastic, irradiating an organic metal compound by laser to form a planar conductive pattern, and then thickening by chemical plating/electroplating to obtain a three-dimensional conductive pattern, but the width of a conductive circuit is difficult to control by the method, and the process reliability is low; (2) based on the selective plating technique: the method comprises the steps of carrying out integral chemical plating on vibrator plastics, then using laser to manufacture and form a barrier line, separating an electroplating area and an non-electroplating area, and carrying out electroplating thickening on the electroplating area to obtain a three-dimensional conductive pattern with required thickness.

Disclosure of Invention

Therefore, the technical problem to be solved by the invention is to overcome the defects of poor process accuracy, low efficiency and high cost of the existing 5G antenna oscillator conductive pattern preparation process, so that a method for preparing the 5G antenna oscillator conductive pattern through selective thickening and differential etching is provided.

In order to solve the technical problems, the technical scheme adopted by the invention is as follows:

the invention provides a method for preparing a 5G antenna oscillator conductive pattern by selective thickening and differential etching, which comprises the following steps:

S1, providing a plastic fixing piece;

s2, preparing a first metal layer on the surface of the plastic fixing piece to form an initial conducting layer;

s3, forming an insulating layer on the surface of the initial conducting layer;

s4, selectively etching the insulating layer along the direction of the pre-designed conductive pattern circuit to expose the initial conductive layer;

s5, preparing a second metal layer on the exposed surface of the initial conductive layer to form a thickened conductive layer;

s6, removing the insulating layer;

and S7, etching all the surfaces of the thickened conducting layer in equal thickness until all the first metal layers are removed, and forming a 5G antenna oscillator conducting pattern.

Preferably, in the method for preparing the 5G antenna element conductive pattern by selective thickening and differential etching, in step S2, the initial conductive layer is formed by an electroless plating method;

the thickness of the initial conductive layer is 0.05-1 μm.

Further preferably, in the method for preparing the conductive pattern of the 5G antenna element by selective thickening and differential etching, the first metal layer is selected from at least one of metal Cu and metal Ni, and the initial conductive layer is formed by an electroless plating method;

wherein, the plating solution component of the chemical plating Cu comprises: 0.6-0.8 g/L NiSO₄·7H₂O, and 28-30 g/L CuSO ₄·5H₂O, 60-70 g/L NaH₂PO₂·H₂O, 0.8-1.0 g/L Na₃C₆H₅O₇·2H₂O, 30-35 g/L H₃BO₃The temperature is 49-51 ℃;

the plating solution for chemical Ni plating comprises the following components: 17-22 g/L NiCl₂·6H₂O, 10-25 g/L NaH₂PO₂·H₂O and 8-15 g/L CH3COONa at the temperature of 90-95 ℃.

Preferably, in the method for preparing the 5G antenna element conductive pattern by selective thickening and differential etching, in step S3, the thickness of the insulating layer is 1-5 μm.

Further preferably, in the method for preparing a conductive pattern of a 5G antenna element by selective thickening and differential etching, in step S5, the second metal layer is selected from metal Cu, and the thickened conductive layer is formed by an electroplating method;

wherein, the plating solution for electroplating Cu comprises the following components: 60-75 g/L of CuSO₄180-200 g/L of H₂SO₄50-100 mg/L of Cl^﹣；

The cathode current density is 2-4A/cm²Anode current density of 1-2A/cm²At a temperature of28～32℃。

Further preferably, in the method for preparing a conductive pattern of a 5G antenna element by selective thickening and differential etching, in step S5, the plating solution for electroplating Cu further includes at least one of 8-16 mg/L MHT brightener, 20-25 mg/L GS leveler, and 3-6 mg/L GS brightener.

Further preferably, in the method for preparing a 5G antenna element conductive pattern by selective thickening and differential etching, in step S6, the insulating layer is removed by dipping alkali liquor or spraying alkali liquor.

Further preferably, in the method for preparing a 5G antenna element conductive pattern by selective thickening and differential etching, in step S7, the thickened conductive layer is etched by using a chemical etching solution;

wherein the chemical etching solution comprises 45-300 g/L FeCl₃40-50 g/L hydrochloric acid;

the etching temperature is 30-50 ℃.

Further preferably, in the method for manufacturing a 5G antenna element conductive pattern by selective thickening and differential etching, in step S1, the plastic fixing member is made of any one material selected from PPS, LCP, and ABS.

The technical scheme of the invention has the following advantages:

1. the invention provides a method for preparing a 5G antenna oscillator conductive pattern by selective thickening and differential etching, which comprises the following steps: providing a plastic fixing piece; preparing a first metal layer on the surface of the plastic fixing piece to form an initial conductive layer; forming an insulating layer on the surface of the initial conducting layer; selectively etching the insulating layer along the pre-designed conductive pattern circuit to expose the initial conductive layer; preparing a second metal layer on the surface of the exposed initial conductive layer to form a thickened conductive layer; removing the insulating layer; and etching all the surfaces of the thickened conductive layer with equal thickness to remove all the first metal layers to form a 5G antenna element conductive pattern.

According to the method for preparing the 5G antenna oscillator conductive pattern through selective thickening and differential etching, the surface of an initial conductive layer is selectively thickened to obtain a thickened conductive layer with uneven thickness, then all surfaces of the thickened conductive layer are subjected to equal-thickness differential etching until all first metal layers are removed, and a formed three-dimensional conductive pattern can be prepared at one time; meanwhile, the second metal layer is prepared through the positive phase insulating layer, so that the initial conducting layer can be thickened, a barrier line does not need to be manufactured, the conducting circuit is high in accuracy, the conducting circuit only needs to be thickened along the line direction area of the conducting pattern, the conducting layer is not needed to be removed in a large-area large-size mode subsequently, the cost is saved, and the efficiency is improved.

2. According to the method for preparing the 5G antenna oscillator conductive pattern through selective thickening and differential etching, the initial conductive layer is formed through a chemical plating method, the thickness of the initial conductive layer is 0.05-1 mu m, compared with an integral 'layer reduction' process, a plating layer is thinner, the preparation efficiency is improved, and the preparation cost is reduced.

3. According to the method for preparing the 5G antenna oscillator conductive pattern through selective thickening and differential etching, the insulating layer is selectively etched, the initial conductive layer is exposed, a 'normal phase' insulating layer pattern is formed, the thickened conductive layer is formed through preparing the second metal layer, the space limitation of the insulating layer is met, the accuracy of the conductive line finally formed by the thickened conductive layer is high, and the process is more reliable. Moreover, compared with the integral 'layer reduction' process, the method only removes the insulating layer position corresponding to the conductive pattern circuit.

4. According to the method for preparing the 5G antenna oscillator conductive pattern through selective thickening and differential etching, when the conductive layer is thickened through chemical etching liquid etching, the initial conductive layer is thin and can be completely removed quickly, at the moment, the electroplated and thickened partial metal layer is etched in the same thickness, and due to the fact that the overall thickness of the thickened conductive layer is different, a differential etching effect is formed, and the rest is the required conductive pattern.

The method finishes the removal of large-area unnecessary metal layers in one-time etching, and has advantages in speed and cost compared with the method for removing metal coatings in large volume by 'layer-reducing' chemical etching and selective electroplating; moreover, because the initial conducting layer is very thin, when the initial conducting layer is completely etched, the influence on the metal layer of the conducting pattern circuit is very small, and the reliability of the conducting pattern is ensured.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

Fig. 1 is a flowchart of a method for preparing a conductive pattern of a 5G antenna element by selective thickening and differential etching according to embodiment 1 of the present invention;

the attached drawings are marked as follows:

1-plastic fixing parts; 2-an initial conductive layer; 3-an insulating layer; 4-thickening the conductive layer; 5-conductive pattern.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in a specific case to those of ordinary skill in the art.

In addition, the technical features involved in the different embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

Example 1

The embodiment provides a method for preparing a 5G antenna element conductive pattern by selective thickening and differential etching, as shown in fig. 1, the method includes the following steps:

s1, providing a plastic fixing piece

The vibrator has the function of guiding and amplifying electromagnetic waves, and is one of key parts of the antenna. Traditional antenna element mainly adopts metal material to make, and in the 5G communication era, great change can take place for the structure of antenna: on one hand, the number of the 5G antenna single-sector oscillators reaches 64-128, even 256, and the oscillators made of metal materials have the problems of high cost, large weight increase and the like; on the other hand, the 5G working frequency is higher and higher, the wavelength is shorter and shorter, the requirement on the size precision of the oscillator is higher and higher, and the size precision of the oscillator made of the metal material cannot meet the requirement of the 5G antenna, so that the electric properties of the antenna, such as gain, a directional diagram, beam pointing, polarization characteristics and the like, are affected.

For the above reasons, the present invention uses the plastic fixing member 1, which is made of any material selected from PPS, LCP, and ABS, and the shape thereof is not limited to a planar or three-dimensional structure composed of a circle, a cylinder, a rectangle, a cuboid, an ellipse, an ellipsoid, a triangle, or a pyramid, and the size thereof is not limited.

In this embodiment, the plastic fixing member 1 is an arch structure composed of a plurality of cuboids, the cross-sectional structure is shown in fig. 1, the material is PPS, the mechanical strength is high, the toughness is excellent, and the dielectric loss is extremely low, so that the electrical performance of the 5G antenna oscillator is ensured. The plastic fixing piece 1 can be directly formed by injection molding, and the surface of the plastic fixing piece is firstly subjected to roughening and cleaning treatment in sequence and then is subjected to activation treatment by adopting a surfactant.

S2, preparing an initial conducting layer

Preparing first metal layers on all surfaces of the plastic fixing piece 1 through a chemical plating method to form an initial conducting layer 2, wherein the thickness of the initial conducting layer is 0.05-1 mu m.

The material of the first metal layer can be one selected from metal Cu or metal Ni, or a mixture of metal Cu and metal Ni.

The chemical Cu plating process comprises the following steps:

the electroless Cu plating solution comprises the following components: 0.6-0.8 g/L NiSO₄·7H₂O, and 28-30 g/L CuSO₄·5H₂O, 60-70 g/L NaH ₂PO₂·H₂O, 0.8-1.0 g/L Na₃C₆H₅O₇·2H₂O, 30-35 g/L H₃BO₃。

And (3) immersing the activated plastic fixing piece 1 into the plating solution at the temperature of 49-51 ℃ for plating for 20-30 minutes, then washing with deionized water, and drying in an oven at the temperature of 70-80 ℃ for 20-30 minutes.

The chemical Ni plating process comprises the following steps:

the chemical Ni plating solution comprises the following components: 17-22 g/L NiCl₂·6H₂O, 10-25 g/L NaH₂PO₂·H₂O, 8-15 g/L CH₃COONa；

And (3) immersing the activated plastic fixing piece 1 into the plating solution at the temperature of 90-95 ℃ for plating for 15-25 minutes, then washing with deionized water, and drying in an oven at the temperature of 65-75 ℃ for 25-35 minutes. The pH value of the plating solution is kept between 5.0 and 5.5 in the plating process.

In this embodiment, the first metal layer is made of Ni, and the plating solution is NiCl (nickel, copper, nickel, and copper₂·6H₂O, 18g/L NaH₂PO₂·H₂O, 12g/L CH₃COONa, the plating temperature is 95 ℃, the plating is carried out for 15 minutes, and then the drying is carried out for 25 minutes at 65 ℃, so that the initial conducting layer 2 with the thickness of 0.5 mu m is obtained, the thickness is thin, the preparation efficiency is high, and the preparation cost is low.

S3, preparing an insulating layer

And preparing the insulating layer 3 on all the surfaces of the initial conducting layer 2 by immersion film forming, electrophoresis film forming, coating film forming and other modes, wherein the thickness is 1-5 mu m.

Specifically, the plastic fixing member 1 with the initial conductive layer 2 is entirely immersed in a liquid photoresist so that the initial insulating layer 3 is formed on all surfaces thereof, and then dried to form the insulating layer 3 with a thickness of 2.5 μm.

S4, selectively etching the insulating layer

Drawing the conductive pattern with a computer according to the customer's requirements, and then using fiber laser or CO₂The laser selectively etches the insulating layer 3 in accordance with the conductive pattern trace to expose the initial conductive layer 2, forming a "normal phase" insulating layer pattern. The second metal layer is prepared through the positive phase insulating layer, so that the thickening of the initial conducting layer can be realized, the manufacturing of a barrier line is not needed, and the accuracy of the conducting line is high.

The laser head can be a single laser head or a plurality of laser heads can work simultaneously by the movement processing of the galvanometer; during the etching process, the turning over of the plastic fixture 1 may be accomplished by the apparatus.

Specifically, as shown in fig. 1, etching is performed in a region A, B, C, D, E, F of the insulating layer 3.

S5, preparing a thickened conducting layer

A second metal layer is prepared on the surface of the exposed initial conductive layer 2 by an electroplating method to form a thickened conductive layer 4. Only need follow the regional bodiness of conductive pattern circuit trend, follow-up need not large tracts of land bulky conducting layer that goes, practiced thrift the cost, promoted efficiency.

The material of the second metal layer may be the same as or different from that of the first metal layer. In this embodiment, the second metal layer is made of Cu.

The Cu electroplating process comprises the following steps:

The plating solution comprises the following components: 60-75 g/L CuSO₄180-200 g/L of H₂SO₄50-100 mg/L of Cl^﹣(ii) a The cathode current density is 2-4A/cm²The current density of the anode is 1-2A/cm²The temperature is 28-32 ℃.

In this embodiment, in order to ensure that the thickness of the second metal layer is larger than that of the first metal layer, the plating solution composition is CuSO with a concentration of 70g/L₄180g/L of H₂SO₄75mg/L NaCl; cathode current density 3A/cm²Anode current density 1.5A/cm²The plating time was 30 minutes at 30 ℃ to finally obtain a second conductive layer 5 μm thick.

In order to make the surface smoothness of the second conductive layer good, an additive such as at least one of 8-16 mg/L MHT brightener, 20-25 mg/L GS leveler and 3-6 mg/L GS brightener is added into the plating solution for electroplating Cu. In this example, 5mg/L of GS brightener was selected.

S6, removing the insulating layer;

and (4) immersing the whole vibrator obtained in the step (S5) in alkali liquor or spraying alkali liquor, and removing the insulating layer 3 (photoresist). The alkali liquor is selected from 5-10% of KOH solution by mass fraction, the obtained thickened conductive layer 4 has uneven surface and different section thicknesses, and the thickness is 5.5 mu m which is the sum of the thicknesses of the first conductive layer and the second conductive layer at the positions of the areas A-F; at other positions, the thickened conductive layer 4 is still the first conductive layer thickness, i.e. 0.5 μm.

S7, thickening the conducting layer by differential etching

And (3) performing differential etching on all the surfaces of the thickened conducting layer 4 to ensure that the etching thickness is equal to the thickness of the first metal layer, and removing all the first metal layers to form a 5G antenna oscillator conducting pattern. Since the initial conductive layer 2 is thin, it can be removed completely and quickly, and at this time, the electroplated and thickened part of the metal layer (i.e. the second metal layer) is etched in the same thickness, and since the thickened conductive layer 4 has different thickness to form a differential etching effect, the remaining area (i.e. the area a-F) is the required conductive pattern 5.

The chemical etching solution is used in the etching process, and the components of the chemical etching solution comprise 45-300 g/L FeCl₃40-50 g/L hydrochloric acid, and the etching temperature is 30-50 ℃. In this example, the chemical etching solution has a composition of 150/L FeCl₃45g/L hydrochloric acid, and an etching temperature of 35 ℃.

It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications therefrom are within the scope of the invention.

Claims (10)

1. A method for preparing a 5G antenna element conductive pattern through selective thickening and differential etching is characterized by comprising the following steps:

s1, providing a plastic fixing piece;

s2, preparing a first metal layer on the surface of the plastic fixing piece to form an initial conducting layer;

s3, preparing an insulating layer on the surface of the initial conducting layer;

s4, selectively etching the insulating layer along the direction of a pre-designed conductive pattern circuit to expose the initial conductive layer;

s5, preparing a second metal layer on the exposed surface of the initial conductive layer to form a thickened conductive layer;

s6, removing the insulating layer;

and S7, etching all the surfaces of the thickened conducting layer with equal thickness to remove all the first metal layers to form a 5G antenna oscillator conducting pattern.

2. The method for preparing a 5G antenna element conductive pattern by selective thickening and differential etching according to claim 1, wherein the thickness of the second metal layer is larger than that of the first metal layer.

3. The method for preparing a conductive pattern of a 5G antenna element by selective thickening and differential etching as claimed in claim 1 or 2, wherein in step S2, the initial conductive layer is formed by an electroless plating method;

The thickness of the initial conductive layer is 0.05-1 mu m.

4. The method for preparing a conductive pattern of a 5G antenna element by selective thickening and differential etching as claimed in claim 3, wherein the first metal layer is selected from at least one of metal Cu and Ni, and the initial conductive layer is formed by an electroless plating method;

wherein, the plating solution for chemical plating of Cu comprises the following components: 0.6-0.8 g/L NiSO₄·7H₂O, 28-30 g/L CuSO₄·5H₂O, 60-70 g/L NaH₂PO₂·H₂O, 0.8-1.0 g/L Na₃C₆H₅O₇·2H₂O, 30-35 g/L H₃BO₃The temperature is 49-51 ℃;

the plating solution for chemical Ni plating comprises the following components: 17-22 g/L NiCl₂·6H₂O, 10-25 g/L NaH₂PO₂·H₂O and 8-15 g/L CH3COONa at the temperature of 90-95 ℃.

5. The method for preparing the conductive pattern of the 5G antenna element by selective thickening and differential etching according to claim 1 or 2, wherein in the step S3, the thickness of the insulating layer is 1-5 μm.

6. The method for preparing a conductive pattern of a 5G antenna element by selective thickening and differential etching as claimed in claim 1 or 2, wherein in step S5, the second metal layer is selected from metal Cu, and the thickened conductive layer is formed by an electroplating method;

wherein, the plating solution for electroplating Cu comprises the following components: 60-75 g/L of CuSO ₄180-200 g/L of H₂SO₄50-100 mg/L of Cl^﹣；

Cathode current density of 2-4A/cm²Anode current density of 1-2A/cm²The temperature is 28-32 ℃.

7. The method for preparing a 5G antenna element conductive pattern through selective thickening and differential etching according to claim 6, wherein in step S5, the Cu-electroplating solution further comprises at least one of 8-16 mg/L MHT brightener, 20-25 mg/L GS leveler and 3-6 mg/L GS brightener.

8. The method for preparing a conductive pattern of a 5G antenna element by selective thickening and differential etching as claimed in claim 1 or 2, wherein in step S6, the insulating layer is removed by dipping or spraying an alkali solution.

9. The method for preparing a 5G antenna element conductive pattern by selective thickening and differential etching according to claim 1 or 2, wherein in step S7, the thickened conductive layer is etched by a chemical etching solution;

wherein the chemical etching solution comprises 45-300 g/L FeCl₃40-50 g/L hydrochloric acid;

the etching temperature is 30-50 ℃.

10. The method for preparing a 5G antenna element conductive pattern through selective thickening and differential etching according to claim 1 or 2, wherein in step S1, the plastic fixing piece material is selected from any one of PPS, LCP and ABS.

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