阅读说明：本技术 通过激光蚀刻和化学抛光降低立体线路喷涂成本的方案 (Scheme for reducing three-dimensional line spraying cost through laser etching and chemical polishing ) 是由 陈设 高亢 刘强 于 2021-09-15 设计创作，主要内容包括：本发明提供通过激光蚀刻和化学抛光降低立体线路喷涂成本的方案,涉及塑胶表面的立体线路的和后续喷涂制造工艺领域。本发明技术方案能够大幅提高镀层区域做在一级外观面上面的时候进行喷涂的良率,显著降低喷涂的厚度,使用本发明专利所述的方案可以把喷涂的次数控制4涂4烤,减少甚至完全消除打磨的必要,喷涂实际厚度控制在60～90微米左右即可实现无痕的喷涂效果。传统的塑料部件立体线路工艺做到线路无痕的喷涂往往需要7涂7烤,外加多次打磨,喷涂涂层的厚度达到150微米左右。良率的提升,喷涂厚度和喷涂步骤的减少可以大幅降低喷涂的成本。(The invention provides a scheme for reducing the spraying cost of a three-dimensional line through laser etching and chemical polishing, and relates to the field of manufacturing processes of the three-dimensional line on the surface of plastic and subsequent spraying. According to the technical scheme, the yield of spraying when the coating area is arranged on the first-level appearance surface can be greatly improved, the spraying thickness is remarkably reduced, the spraying frequency can be controlled to be 4-coating and 4-baking by using the scheme disclosed by the invention, the polishing requirement is reduced and even completely eliminated, and the traceless spraying effect can be realized by controlling the actual spraying thickness to be about 60-90 micrometers. The traditional three-dimensional circuit process for the plastic parts has the advantages that the traceless spraying of the circuit usually needs 7-coating and 7-baking, and multiple times of polishing are added, so that the thickness of a sprayed coating reaches about 150 micrometers. The yield is improved, the spraying thickness and the spraying steps are reduced, so that the spraying cost can be greatly reduced.)

1. The scheme for reducing the spraying cost of the three-dimensional line through laser etching and chemical polishing is characterized by comprising the following specific process steps:

line laser forming and deep etching: in order to ensure the smoothness and the etching depth of the plastic circuit area after laser processing and etching and the plating performance of subsequent chemical plating, the selection of laser equipment and a light source comprises the following steps:

a. selecting a light source with shorter wavelength and lighter thermal expansion effect, such as a green light, blue light or purple light laser light source;

b. selecting a small spot diameter of 0.03mm or less to better control the smoothness of the scanned area;

c. when the optical fiber laser light source is used, in order to prevent the problems of plastic expansion and too coarse caused by the heat effect of light spots, the power and the scanning mode of the laser are preferably a low-power low-frequency repeated laser scanning mode;

d. in order to ensure that the laser scanning etched area is not too rough and has wave-shaped laser scanning stripes to influence the smoothness of the circuit, a low-power multiple (two or more) cross scanning mode is preferably adopted during laser scanning;

e. in order to prevent the problem that the edge of a plastic scanning area is protruded due to the fact that the light spot is plated on the plastic recasting area/flanging along the edge, the laser energy of the contour line adopts a differential laser parameter method (the position energy is smaller than the energy of an internal scanning area, or the energy scanned by the laser each time is set in an energy range with smaller flanging risk), the size of the recasting area/flanging at the position is reduced, and the risk of step protrusion caused by plating on the position is reduced;

f. the laser equipment has the capability of flexibly adjusting the laser angle and the laser focal length of a product, and has an automatic focusing mechanism for angle adjustment and dynamic focusing, and in addition, when the three-dimensional surface is machined, the height difference of the machined surface is considered, and the software of the laser equipment can automatically adjust the focal length, so that the consistency of plating can be improved;

step two, chemical plating trial plating: in order to ensure the quality of the sprayed coating, the smoothness of the coating and the size of a step need to be strictly controlled, and in order to ensure the result, the parameters of the laser and the etching depth need to be optimized. The purpose of chemical plating trial plating is to determine whether the laser parameters are easy to plate, meet the test requirements of reliability such as plating layer hundreds, and determine and judge the optimal laser parameters, etching depth and plating layer thickness by combining with a slicing experiment;

step three, etching depth and plating step slicing experiment: the device is a metallographic microscope with a size measuring function, a metallographic polishing machine or an imager with a surface three-dimensional scanning function to determine the depth of a laser spot and a scanning area;

determining the etching depth, the laser parameters and the plating thickness: in combination with slice monitoring data of the coating, such as depth of laser etching, step size of the coating edge and coating finish, the corresponding optimal laser processing parameters, chemical polishing time requirements and coating thickness can be determined. The thickness of the copper plating before polishing is controlled to be 1-5 microns in depth of laser etching; the optimal value of the coating thickness of the whole chemical plating finished product is consistent with the depth of laser etching, so that the surface of the coating is basically flush with the surface of the plastic in theory, and the masking effect of spraying is facilitated.

Fifthly, batch production, namely laser processing and chemical copper plating;

and sixthly, performing chemical polishing and coating surface protection treatment.

2. The solution for reducing the cost of three-dimensional line painting by laser etching and chemical polishing as claimed in claim 1, wherein the light source with relatively light thermal expansion effect with shorter wavelength in the first step is preferably a green, blue or violet light source.

3. The solution for reducing the cost of spacial line painting by laser etching and chemical polishing as claimed in claim 1, wherein the chemical polishing uses but is not limited to the following:

chromate system processes that utilize the strong oxidizing properties of hexavalent chromium to polish copper;

the three-acid system process mainly utilizes the coordination of inorganic acids such as nitric acid, sulfuric acid, hydrochloric acid and the like to carry out polishing;

the hydrogen peroxide system polishing solution mainly utilizes the strong oxidizing property of hydrogen peroxide to polish copper.

4. The scheme for reducing the spraying cost of the three-dimensional line through laser etching and chemical polishing as claimed in claim 1, wherein the surface plating treatment in the sixth step is to prevent the oxidation of the plating layer and meet the requirement of practical use of subsequent products, nickel and nickel passivation protection can be plated when welding is not needed, and gold plating can be performed when welding is needed.

Technical Field

The invention relates to the field of spraying and manufacturing processes of three-dimensional lines on plastic surfaces, in particular to a scheme for reducing spraying cost of three-dimensional lines through laser etching and chemical polishing.

Background

The laser direct forming is a manufacturing process of adding a special metal complex into plastic particles, activating and decomposing the metal complex through laser forming to form fine metal particles, and then performing chemical nickel plating and copper plating around the metal particles to manufacture circuits on the surface of a plastic structural member. The latest process of the plastic part three-dimensional circuit can realize that the three-dimensional circuit is manufactured on the surface of the plastic by the metal such as nickel-plated copper and the like through laser coarsening and forming on the surface of the common plastic and combining chemical pretreatment and activation.

The technical routes all need to carry out laser processing on the surface of the plastic by laser, and then combine chemical plating to deposit metal on the laser processed area to realize the three-dimensional circuit manufacturing. When laser beam machining plastic surface, the facula is protruding around, leads to plastic surface roughness to increase, simultaneously because reasons such as heat effect, the edge of the metallic coating of three-dimensional circuit further plates the size of the step that produces and between the plastic face because of plastic arch and protruding position and has apparent influence to the effect of spraying. The worse the surface roughness of the coating, the higher the edge step, and the more difficult the traceless effect of the first-level appearance surface is to be realized. For these reasons, the products manufactured by these three-dimensional line processes have high defective rate of spraying when the lines are on the first-class appearance surface, and the thickness requirement of spraying is very thick, which affects the appearance quality of the products and seriously increases the spraying cost.

Disclosure of Invention

Technical problem to be solved

Aiming at the defects of the prior art, the invention provides a scheme for reducing the spraying cost of the three-dimensional circuit through laser etching and chemical polishing, and solves the problems that when a circuit of a product manufactured by a three-dimensional circuit process is on a first-level appearance surface, the spraying reject ratio is high, the spraying thickness requirement is very thick, the appearance quality of the product is influenced, and the spraying cost is seriously increased.

(II) technical scheme

In order to achieve the purpose, the invention is realized by the following technical scheme: the scheme for reducing the spraying cost of the three-dimensional line by laser etching and chemical polishing comprises the following specific process steps:

line laser forming and deep etching: in order to ensure the smoothness and the etching depth of the plastic circuit area after laser processing and etching and the plating performance of subsequent chemical plating, the selection of laser equipment and a light source comprises the following steps:

a. selecting a light source with shorter wavelength and lighter thermal expansion effect;

b. selecting a small spot diameter of 0.03mm or less to better control the smoothness of the scanned area;

c. in order to ensure that the laser scanning etched area is not too rough and has wave-shaped laser scanning stripes to influence the smoothness of the circuit, a mode of two or more times of cross scanning is preferably adopted during laser scanning;

d. the laser equipment has the capability of flexibly adjusting the laser angle and the laser focal length of a product, and has an automatic focusing mechanism for angle adjustment and dynamic focusing, so that the relation between the laser processing surface of the product and a laser beam can be better controlled, the consistency of laser engraving effects on different surfaces can be realized as far as possible, in addition, when the three-dimensional surface is processed, the height difference of the processed surface is considered, the software of the laser equipment can preferably automatically adjust the focal length, and the consistency of the carbonization effects of different processed areas can be better ensured;

e. in order to prevent the problem that the edge of a plastic scanning area is raised due to the fact that light spots are plated on the plastic recasting area/flanging along the edge, the size of the recasting area/flanging at the position is reduced by adopting a differential laser parameter method (the position energy is smaller than that of the internal scanning area) for the laser energy of the contour line, and the risk of step raising caused by plating on the position is reduced;

f. the laser equipment has the capability of flexibly adjusting the laser angle and the focal length of a product, and has an automatic focusing mechanism for angle adjustment and dynamic focusing.

Step two, chemical plating trial plating: in order to ensure the spraying quality, the smoothness of a coating and the size of a step need to be strictly controlled, the laser parameters and the etching depth need to be optimized to ensure the result, and the purpose of chemical plating trial plating is to determine whether the laser parameters are easy to plate, meet the test requirements of reliability such as coating check, and determine the optimal laser parameters, etching depth and coating thickness by combining with a slicing experiment;

step three, etching depth and plating step slicing experiment: the used equipment is a metallographic microscope and a metallographic polishing machine with a size measurement function;

determining the etching depth, the laser parameters and the plating thickness: in combination with slice monitoring data of the coating, such as depth of laser etching, step size of the coating edge and coating finish, the corresponding optimal laser processing parameters, chemical polishing time requirements and coating thickness can be determined. The thickness of the copper plating before polishing is controlled to be 1-5 microns in depth of laser etching; the optimal value of the plating thickness of the whole chemical plating finished product is consistent with the depth of laser etching;

fifthly, batch production, namely laser processing and chemical copper plating;

and sixthly, performing chemical polishing and surface coating treatment.

Preferably, the light source with relatively low thermal expansion effect in the short wavelength in the first step is preferably a green, blue or violet light source.

Preferably, the metallographic microscope is replaced by a scanner with a magnification of more than 500 times or a three-dimensional scanning function, and the test instrument with the three-dimensional surface scanning function is simpler in laser processing or coating surface effect analysis, more intuitive in analysis data and result and capable of greatly reducing related detection and analysis time.

Preferably, the chromate system process polishes copper, or the three-acid system process (the process mainly utilizes the combination of inorganic acids such as nitric acid, sulfuric acid and hydrochloric acid to polish) or the hydrogen peroxide system polishing solution (the system mainly utilizes the strong oxidizing property of hydrogen peroxide to polish copper).

Preferably, the surface plating treatment in the sixth step is to prevent the oxidation of the plating layer and meet the requirement of the practical use of subsequent products, nickel plating and nickel passivation protection can be carried out when welding is not needed, and gold plating can be carried out when welding is needed.

(III) advantageous effects

The invention provides a scheme for reducing the spraying cost of a three-dimensional line by laser etching and chemical polishing.

The method has the following beneficial effects:

1. the technical scheme of the invention can obviously improve the smooth finish of the three-dimensional circuit coating, the step size of the coating edge and the smoothness of the circuit edge.

2. According to the technical scheme, the yield of spraying when the coating area is arranged on the first-level appearance surface can be greatly improved, the spraying thickness is remarkably reduced (6-coating 6-baking or even 7-coating 7-baking is realized in the thickness of spraying of the traditional three-dimensional line process, and the trace-free effect of the line area can be realized only when the actual sprayed film thickness reaches about 150 micrometers). The yield is improved, the spraying thickness and the spraying steps are reduced, so that the spraying cost can be greatly reduced.

Drawings

FIG. 1 is a flow chart of a scheme of the present invention for reducing the cost of three-dimensional line painting by laser etching and chemical polishing;

FIG. 2 is a comparison of the edge and surface roughness of the coating before and after chemical polishing (left side is the effect of the coating on the cut and front after chemical polishing, and right side is the effect of the unpolished cut and front);

FIG. 3 is a three-dimensional scanning image of the plating surface of the three-dimensional circuit;

FIG. 4 is a graph showing the height variation of etched and unetched regions of a plastic surface after laser etching;

FIG. 5 is a photograph showing a comparison of plastic surfaces scanned with red and violet light (red light on the left and violet light on the right);

fig. 6 is an effect diagram of laser processing of the LDS and the general three-dimensional line process.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. 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.

The first embodiment is as follows:

as shown in fig. 1 to 6, the embodiment of the present invention provides a solution for reducing the cost of three-dimensional line spraying by laser etching and chemical polishing, which includes the following specific process steps:

line laser forming and deep etching: in order to ensure the smoothness and the etching depth of the plastic circuit area after laser processing and etching and the plating performance of subsequent chemical plating, the selection of laser equipment and a light source comprises the following steps:

a. selecting a light source with shorter wavelength and lighter thermal expansion effect, such as a green light, blue light or purple light laser light source;

b. selecting a small spot diameter of 0.03mm or less to better control the smoothness of the scanned area;

c. when the optical fiber laser light source is used, in order to prevent the problems of plastic expansion and too coarse caused by the heat effect of light spots, the power and the scanning mode of the laser are preferably a low-power low-frequency repeated laser scanning mode;

d. in order to ensure that the laser scanning etched area is not too rough and has wave-shaped laser scanning stripes to influence the smoothness of the circuit, a low-power multiple (two or more) cross scanning mode is preferably adopted during laser scanning;

e. in order to prevent the problem that the edge of a plastic scanning area is raised due to the fact that light spots are plated on the plastic recasting area/flanging along the edge, the size of the recasting area/flanging at the position is reduced by adopting a differential laser parameter method (the position energy is smaller than that of the internal scanning area) for the laser energy of the contour line, and the risk of step raising caused by plating on the position is reduced;

f. the laser equipment has the capability of flexibly adjusting the laser angle and the laser focal length of a product, and has an automatic focusing mechanism for angle adjustment and dynamic focusing, and in addition, when the three-dimensional surface is machined, the height difference of the machined surface is considered, and the fact that the laser equipment can automatically adjust the focal length can help to improve the consistency of plating;

step two, chemical plating trial plating: in order to ensure the spraying quality, the smoothness of a coating and the size of a step need to be strictly controlled, the laser parameters and the etching depth need to be optimized to ensure the result, and the purpose of chemical plating trial plating is to determine whether the laser parameters are easy to plate, meet the test requirements of reliability such as coating check, and determine the optimal laser parameters, etching depth and coating thickness by combining with a slicing experiment;

step three, etching depth and plating step slicing experiment: the used equipment is a metallographic microscope and a metallographic polishing machine with a size measurement function;

determining the etching depth, the laser parameters and the plating thickness: in combination with slice monitoring data of the coating, such as depth of laser etching, step size of the coating edge and coating finish, the corresponding optimal laser processing parameters, chemical polishing time requirements and coating thickness can be determined. The thickness of the copper plating before polishing is controlled to be 1-5 microns in depth of laser etching; the optimal value of the plating thickness of the whole chemical plating finished product is consistent with the depth of laser etching;

fifthly, batch production, namely laser processing and chemical copper plating;

and sixthly, performing chemical polishing and surface coating treatment.

In the first step, the light source with shorter wavelength and relatively lighter thermal expansion effect is preferably a green light source, a blue light source or a purple light source, and the metallographic microscope is an imaging instrument with the magnification of more than 500 times, and the following chemical polishing modes are used, but not limited to: chromate system processes that utilize the strong oxidizing properties of hexavalent chromium to polish copper; the three-acid system process mainly utilizes the coordination of inorganic acids such as nitric acid, sulfuric acid, hydrochloric acid and the like to carry out polishing; the hydrogen peroxide system polishing solution mainly utilizes the strong oxidizing property of hydrogen peroxide to polish copper, the surface plating treatment in the sixth step is to prevent the oxidation of the plating and meet the actual use requirement of subsequent products, nickel plating and nickel passivation protection can be realized when welding is not needed, and gold plating can be realized when welding is needed.

Example two:

the line laser forming and deep etching method comprises the following steps:

A. cold light source method: in order to ensure the smoothness and the etching depth of a plastic circuit area after laser processing and etching and the plating performance of subsequent chemical plating, a laser light source is selected, when a common plastic surface three-dimensional circuit process is used, green light, blue light or purple light is better selected, and the protruding degree of the periphery of a light spot caused by the heat effect of the laser light source is obviously smaller than that of a laser light source of red light. The depth and finish of the laser etch is easier to achieve when using green, blue or violet light sources because the spot relief due to their thermal effect is smaller compared to red light.

B. Small diameter spot method: the slightly smaller diameter of the light spot, such as 0.03mm, can obviously improve the smoothness of a laser scanning area, meanwhile, the energy is more concentrated after the light spot becomes smaller, the thermal expansion effect of plastic around the light spot is reduced, and the flanging effect is reduced.

C. Sub-nanosecond or picosecond laser method: in order to further reduce the problem of light spot edge protrusion caused by the thermal effect of the laser light spot, the adoption of a sub-nanosecond or picosecond laser is beneficial to further reducing the protrusion degree caused by the thermal expansion of the laser light spot edge due to the short laser pulse time and the high laser light spot intensity, for example, a red light source is selected, and a red light device with adjustable pulse width or a sub-nanosecond or picosecond red light device with shorter pulse width is preferably selected. The red light source with adjustable pulse width is selected, and the flanging problem caused by the heat effect around the light spot can be reduced to a certain extent under the reasonable laser parameter setting of low power and low frequency.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.