KR101457259B1 - Method of manufacturing plastic metallized three-dimensional circuit - Google Patents

Abstract

A method of manufacturing a metal-encapsulated plastic 3D circuit includes providing a 3D plastic body; Performing surface pretreatment on the plastic body; Performing a metal coating process on the plastic body to deposit a thin metal film; Performing a photoresist coating process to form a photoresist protective film on the thin metal film; Exposing and developing the photoresist protective film to form a patterned photoresist protective film; Performing an etching process on the exposed thin metal film to form a patterned metal circuit film; Peeling the patterned metal circuit film to form a metal protective film; And performing a surface treatment on the patterned metal circuit film to form a metal protective film. In this way, the 3D circuit pattern is formed directly on the 3D plastic body without providing additional circuit carriers to meet the demand for compact and compact electronic devices.

Description

[0001] METHOD OF MANUFACTURING PLASTIC METALLIZED THREE-DIMENSIONAL CIRCUIT [0002]

The present invention relates to a method of manufacturing a metal-clad three-dimensional (3D) circuit and a method of forming a 3D patterned metal circuit on the surface of a plastic body of a 3D structure.

With the rapid development of the wireless communication field, more attention has been drawn to the demand for the quality of signal transmission, the miniaturization and the lighter weight of all types of electronic communication devices. Generally, antennas of various types of mobile video communication products, such as tablet computers and cellular phones, have difficulties in designing the body structure, the arrangement of the circuit corresponding to the appearance, and the internal structures of the products to meet the demand for miniaturization.

According to the currently available molding technology, that is, laser direct structuring (LDS), a specific plastic material activated by the laser is injection-molded into a predetermined body structure, and a circuit pattern a laser beam of a specific wavelength is used to activate the metal crystal grains in the plastic material. Finally, a metal metallization process is performed on the body to obtain the desired circuit. The LDS technology also applies to other products without limitation, such as cellular phones, antennas for mobile computers, light-emitting diode modules, automotive interiors, and the like.

However, plastic materials for LDS use must be doped with metal catalysts, and the proportions of other constituents of the added metal catalyst must be changed, depending on the type and nature of the plastic material used. In addition, the conditions for laser activation depend on the other metal catalysts added. Therefore, in the use of LDS technology, it is necessary to adjust the laser wavelength, and to control the parameters for the metal metallization process followed by the plastic material used and the added metal catalyst. That is, LDS technology requires laser equipment capable of providing a laser beam of a specific wavelength, and metal sheeting equipment capable of setting different parameters and controlling parameters, thus requiring significantly more expensive equipment and manufacturing costs.

In addition, in using LDS technology, the rise of the surface temperature of the body causes metal crystal grains to be removed or broken at a portion of the body surface, or deposition of metal crystal grains on the surface of the body occurs at portions where it is not expected to form a circuit Which reduces the selectivity of the deposited conducting circuits in subsequent metal coating processes and thus short-circuiting problems between adjacent electrical elements. In order to avoid the possibility of shorting and problems arising in the subsequent metal coating process, it is necessary to control the space between the circuit paths during the LDS.

However, large spaces between circuit paths often cause other problems, such as lack of circuit density. Therefore, the present inventors have made efforts to develop a method of manufacturing a metal-clad plastic three-dimensional circuit in order to overcome the problems and disadvantages in the conventional techniques for forming circuits in a miniaturized electric device.

The main object of the present invention is that the three-dimensional circuit structure can be formed in any three-dimensional plastic body, and the metal circuit layer of the three-dimensional circuit can be three-dimensionally arranged to form an array of patterned circuits. Dimensional circuit of a metal-clad plastic three-dimensional circuit which can be selectively formed on any one or more of the surfaces of the plastic body, the method comprising the steps of: the present invention can be applied to a variety of differently modified three-dimensional structures such as circuit boards, connectors, electronic devices, steering wheels, and the like.

In order to achieve the above objects and other objects, a method of manufacturing a metal-clad plastic three-dimensional circuit according to the present invention comprises the following steps:
(1) providing a plastic body of a 3D structure;
(2) performing a surface pretreatment on the surface of the plastic body, said surface pretreatment comprising surface degreasing, surface lubrication, sensitization and activation treatment carried out in the specified order;
(3) performing a metal coating process, either low-temperature sputtering or plastic water-plating, on the pretreated surface of the plastic body to deposit a thin metal film;
(4) performing a photoresist coating process on the surface of the thin metal film through either dip coating or spray coating to form a photoresist protective film;
(5) A step of exposing and developing the photoresist protective film to form a patterned photoresist protective film. The exposure process is one of a single-sided exposure and a double-sided exposure Direct irradiation from one of a laser light source and an ultraviolet (UV) light source for the position of the photoresist protection film defined by the area of the photoresist protection film defined by the specific 3D exposure circuit pattern or the specific 3D exposure circuit pattern, The 3D exposed circuit pattern is a directly scanned pattern;
(6) performing an etching process on a portion of the thin metal film not covered with the patterned photoresist protective film to form a patterned metal circuit film under the patterned photoresist protective film;
(7) performing a stripping process to peel the patterned photoresist protective film from the patterned metal circuit film; And
(8) Performing a surface treatment on the surface of the patterned metal circuit film to form a metal protective film made of metal by a chemical plating process.

In the present invention, the plastic body may be made of a material selected from the group consisting of polyethylene (PE), polystyrene (PS), polycarbonate (PC), ABS resin (acrylonitrile-butadiene-styrene) (ABS), polyethylene terephthalate Polyethylene terephthalate (PET), polybutylene terephthalate (PBT), liquid crystal polymers (LCP), polyamide (PA6 / 6T), nylon, A material selected from the group consisting of polyoxymethylene (POM), polypropylene (PP), extruded or injected fiberglass, and composites thereof is injection molded, Or extrusion molding.

In an embodiment, surface degreasing includes the use of an acid or an alkaline cleaning agent to remove dust and grease from the surface of the body.

Surface roughening has been used for mechanical abrasion, blasting (to reduce roughness), to degrade the degreased surfaces of the plastic body, to the extent that plastic body surfaces are modified to hydrophilic porous surfaces. blasting, chemical etching or plasma etching, advantageously increasing the bonding force between the plastic body and the later formed metal film. In an embodiment of the invention, the chemical etching is carried out using a surface roughening reagent such as a mixed solution of chromium and sulfuric acid, persulfide, hydrogen peroxide, permanganate or sulfuric acid-based compounds, agent or the use of a strong oxidant produced by a diaphragm electrolysis system.

In the sensitization treatment, stannous chloride is mixed with tin ions, including Sn2 +, which is contained in the acidic solution, and then added to the roughened surface of the plastic body formed by surface lubrication So that tin ions are absorbed on the roughened surface of the plastic body.

In the activation treatment, palladium chloride is mixed with palladium ions, including Pd2 +, which is contained in an acidic solution, followed by subsequent formation of a thin metal film in a metal coating process via metal deposition To form active metal particles in a continuous implantation reaction to promote the formation of active metal particles.

In addition, in the metalization process, a metal material is deposited on the surface of the plastic body to form a thin metal film; And the deposited metal material is selected from the group consisting of nickel (Ni), cobalt (Co), palladium (Pd), tin (Sn), copper (Cu)

The photoresist coating process includes dip coating, pad printing or spray coating of a liquid photoresist to coat a photoresist protective film on the surface of a thin metal film. do; The liquid photoresist for forming the photoresist protective film may be a positive photoresist or a negative photoresist.

 In the present invention, the 3D exposure circuit pattern serves as a 3D circuit pattern mask for selective exposure.

In the present invention, the development process is performed by spraying a developing agent or soaking the developer; The etching process is performed by spraying an etching agent or soaking the etching solution; The stripping process is performed by spraying a stripping agent or soaking the stripping solution.

In the present invention, the surface treatment includes the use of a chemical plating process to form the metal protective film; And the metal protective layer is selected from the group consisting of nickel (Ni), copper (Cu), gold (Au), silver (Ag), tin (Sn), chromium (Cr)

In accordance with the method of manufacturing a metal-encapsulated plastic 3D circuit according to the present invention, the body can be made of a common plastic material without the need for the use of specific materials with metal catalyst added. Thus, a wide range of plastic materials can be considered for use to reduce the cost of materials. In addition, 3D circuits with complicated circuit patterns are flexibly manufactured without being limited by mold arrangements, processing facilities or complex circuit structures, as in conventional circuit forming techniques.

In addition, the patterned metal circuit is formed integrally with the body, and is used to save the assembling procedure of the metal performing the plating on the body of the plastic body which is manufactured independently of the metal body, There is a strong bonding force between the metal and the plastic to solve the problem of separation between the metal body and the plastic body.

The above structure and the technical means applied by the present invention in order to achieve the above object and other objects can be certainly understood with reference to the following embodiments and the detailed description of the drawings accompanying the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a flow chart showing the steps involved in a method of manufacturing a metal-clad plastic 3D circuit in accordance with an embodiment of the present invention;
Figure 2 schematically shows a surface pretreatment of a plastic body according to the method of the invention;
Figure 3 schematically shows the metal coating process and the metal coating process performed on the plastic body according to the method of the present invention;
Figure 4 schematically shows the exposure and development process performed on the plastic body according to the method of the present invention;
5 schematically shows an etching process and a stripping process carried out on a plastic body according to the method of the present invention; And
Fig. 6 schematically shows that the plastic body is subjected to surface treatment according to the method of the present invention to form a metal protective film.

The present invention will now be described in detail with reference to several embodiments and accompanying drawings. The accompanying drawings are merely intended to facilitate an easy reference of the present invention and are not intended to limit the invention in any way.

FIG. 1 is a flow chart illustrating the steps involved in a method of fabricating a metal-encapsulated plastic 3D circuit in accordance with an embodiment of the present invention, and FIGS. 2 to 6 illustrate other steps of the method of the present invention. Please refer to Fig. 1 together with Fig. 2 to Fig.

In the first step of the method, a body 10 of 3D structure is provided. The plastic body 10 is formed by a method of injection molding extrusion molding.

In an embodiment, the plastic body is made of polyethylene (PE), polystyrene (PS), polycarbonate (PC), acrylonitrile-butadiene-styrene (ABS), polyethylene terephthalate Polyethylene terephthalate (PET), polybutylene terephthalate (PBT), liquid crystal polymers (LCP), polyamide (PA6 / 6T), nylon, A material selected from the group consisting of polyoxymethylene (POM), polypropylene (PP), extruded or injected fiberglass, and all the resulting compounds.

As shown in FIG. 2, according to the method of the present invention, the plastic body 10 is of the same construction as an injection molding bowl defined internally as a recess. There are a number of other 3D structures, such as irregularly shaped protrusions, visa and curved surfaces, in the recess of the body.

In the present invention, the main body 10 may be made of a general plastic material without using a specific material to which a metal catalyst is attached. Thus, a wide range of plastic materials can be considered for use in reducing material costs. In addition, 3D circuits with complicated circuit patterns are flexibly manufactured without being limited by mold arrangements, processing facilities or complex circuit structures, as in conventional circuit forming techniques.

In the second step of the method, a surface pretreatment 11 is carried out on the surface of the plastic body 10. The surface pretreatment 11 includes surface degreasing, surface roughening, sensitization treatment, and activation treatment.

An acid or alkaline cleaner is used to remove dust and grease from the surface of the plastic body 10 in the surface degreasing.

In the surface roughening process, the mechanical surface 10 is roughened to degrade the degreased surfaces of the plastic body 10 by more than modifying it to hydrophilic porous surfaces. Mechanical abrasion, blasting, chemical etching, or plasma etching is used. These advantageously increase the bonding force between the plastic body 10 and the metal film formed thereafter.

 In a practicable example, the chemical etching is carried out using a mixed solution of chromium and sulfuric acid, persulfide, hydrogen peroxide, a permanganate or sulfuric acid based compound, or a diatomic electrolytic system the use of a surface roughening agent such as a strong oxidizing agent produced by the diaphragm electrolysis system.

In the sensitization treatment, stannous chloride is mixed with tin ions (Sn2 +) contained in the acidic solution and holes in the roughened surface of the plastic body to be absorbed on the surface of the plastic body .

In this activation treatment, palladium chloride is mixed with the palladium ions (Pd < 2 + >) contained in the acidic solution, and is subjected to continuous deposition in order to facilitate the subsequent formation of the metal film of the plastic body through metal deposition Forming active metal particles in the implantation reaction.

As shown in FIG. 2, surface degreasing, surface roughening, sensitization treatment, and activation treatments can be used to remove dust and grease, Active metal particles that promote the formation of metal films of the plastic body to absorb tin ions and through metal deposition to modify the surface to hydrophilic porous surfaces, Is performed on the inner and outer surfaces of the plastic body 10 to activate the implantation reaction to form the plastic body 10.

In the third step of the method, a thin metal film 12 is deposited on the pretreated surface of all plastic bodies 10 as a result of the metal coating process being performed on the surface of the plastic body. In the metal coating process, a metal material is deposited on the surface of the plastic body 10 to form a thin metal film by low-temperature sputtering or plastic water plating.

In an embodiment, the deposited metal may be Ni, Co, Pd, Sn, Cu, and all the resulting compounds thereof.

As shown in FIG. 3, the metal deposition is carried out on the surface of the plastic body 10 pretreated in the second step, resulting in a thin metal film 12 having irregularly shaped protrusions, a visa, And curved surfaces. Due to the vias formed in the plastic body, the thin metal films 12 on the inner and outer surfaces of the plastic body 10 are electrically connectable to one another.

In the fourth step of the method, a photoresist coating process is performed so that a photoresist protective film 13 can be formed on the surface of the thin metal film 12. [ The photoresist process includes dip coating, pad printing, or spray coating of a liquid photoresist to form a photoresist protective film 13 on the thin metal film 12. [ In the pad printing, a printing pad is used to transfer the liquid photoresist to the thin metal film 12 to form a photoresist protective film 13 having a 3D circuit pattern.

In an embodiment, the liquid photoresist for forming the photoresist protective film 13 may be a positive photoresist or a negative photoresist.

As shown in FIG. 3, the photoresist protective film 13 is formed by a metal coating (not shown) in a third step including the above-mentioned irregularly shaped protrusions, a visa, and curved surfaces, Is formed in the plastic body 10 in the region where the process is to be performed.

In the fifth step of the method, the exposure and development process 17 is performed in the photoresist protection film 13 to form the patterned photoresist protection film 14. The exposure process may be one or two-sided exposure; The developing process may be performed by spraying or soaking the developing solution.

In an embodiment, the exposure process includes an ultraviolet (UV) light source directly illuminating a region or location of a photoresist protection film defined by irradiation of a laser light source or a specific 3D exposure circuit pattern. The 3D exposed circuit pattern may be a 3D mask mold, a pad printing circuit pattern, or a directly scanned pattern. In addition, the 3D mask mold is made of a metal material, a plastic material, or a silicon material; And a light slot for a specific circuit pattern and serves as a 3D circuit pattern mask for selective exposure.

4, in the present invention, as a result of the double-side exposure being performed on the plastic body 10, a first exposure pattern 171 is formed on the inner surface of the plastic body 10, while a second exposure pattern 172 are formed on the outer surface of the plastic main body 10. Then, the photoresist protection film is partially exposed by the developer, thereby forming a patterned photoresist protection film 14.

In the sixth step of the method, an etching process is performed to form a patterned metal circuit film 15 under the patterned photoresist protective film 14 in the thin metal film 12 exposed from the patterned photoresist protective film 14 . Therein, the etching process is performed by spraying an etchant or soaking the etchant. '

As shown in FIG. 5, the thin metal film 12 positioned below and protected under the patterned photoresist protection film is etched by an etchant to directly form the patterned metal circuit film 15 corresponding to the patterned photoresist protection film 14 It is not etched.

In the seventh step of the method, a stripping process is performed to peel off the patterned photoresist protective film 14 from the patterned metal circuit film 15. Wherein the stripping process is carried out by spraying or soaking the stripping solution.

As shown in Fig. 5, the patterned photoresist protective film 14 covering the patterned metal circuit film 15 is completely stripped using the stripping solution exposing the patterned metal circuit film 15. [0035]

In the eighth step of the method, the surface treatment is carried out to form the metal protective film 16 in the patterned metal circuit film 15. The surface treatment includes a chemical plating process. That is, it refers to electroless plating for forming the metal protective film 16.

In an embodiment, the metal protective film 16 is formed of nickel (Ni), copper (Cu), gold (Au), silver (Ag), tin (Sn), chromium (Cr) .

6, in the present invention, the chemical plating process is performed on the patterned metal circuit film 15 formed on the inner surface or the outer surface of the plastic body 10, It has an increased thickness for forming the protective film 16, which gives the metal circuit film more improved antioxidant ability and weldability.

In summary, with the method of manufacturing a metal-encapsulated plastic 3D circuit according to the present invention, a 3D circuit can be formed in any 3D plastic body. The metal circuit film of the 3D circuit can be selectively formed on the surfaces of one or more 3D plastic bodies that achieve a patterned circuit arrangement, and can be formed of antennas, LED carriers, circuit boards, Such as those that do not require the provision of additional circuit carriers in the body, connectors, electronic devices, steering wheels, and the body, for example. Thus, the volume of the body that meets the requirements for use in miniaturized, compact and lightweight electronic devices can be reduced.

The present invention has been described in terms of embodiments and is understood by many changes and modifications in the above-described embodiments, which can be carried out without departing from the scope or spirit of the invention, which is intended to be limited only by the appended claims.

Claims (16)

A method of manufacturing a metallized plastic three-dimensional (3D) circuit comprising the steps of:
(1) providing a plastic body of a 3D structure;
(2) performing a surface pretreatment on the surface of the plastic body, said surface pretreatment comprising surface degreasing, surface lubrication, sensitization and activation treatment carried out in the specified order;
(3) performing a metal coating process, either low-temperature sputtering or plastic water-plating, on the pretreated surface of the plastic body to deposit a thin metal film;
(4) performing a photoresist coating process on the surface of the thin metal film through either dip coating or spray coating to form a photoresist protective film;
(5) A step of exposing and developing the photoresist protective film to form a patterned photoresist protective film. The exposure process is one of a single-sided exposure and a double-sided exposure Direct irradiation from one of a laser light source and an ultraviolet (UV) light source for the position of the photoresist protection film defined by the area of the photoresist protection film defined by the specific 3D exposure circuit pattern or the specific 3D exposure circuit pattern, The 3D exposed circuit pattern is a directly scanned pattern;
(6) performing an etching process on a portion of the thin metal film not covered with the patterned photoresist protective film to form a patterned metal circuit film under the patterned photoresist protective film;
(7) performing a stripping process to peel the patterned photoresist protective film from the patterned metal circuit film; And
(8) Performing a surface treatment on the surface of the patterned metal circuit film to form a metal protective film made of metal by a chemical plating process. The method according to claim 1,
The plastic body may be made of polyethylene (PE), polystyrene (PS), polycarbonate (PC), ABS resin (ABS), polyethylene terephthalate PET, polybutylene terephthalate (PBT), liquid crystal polymers (LCP), polyamide (PA6 / 6T), nylon, polyoxymethylene, (POM), polypropylene (PP), extruded or injected fiberglass, and combinations thereof. The metal-coated plastic A method of manufacturing a 3D circuit. The method according to claim 1,
Wherein the plastic body is formed by a method selected from the group consisting of injection molding and extrusion molding. delete The method according to claim 1,
Wherein said surface degreasing comprises the use of an acid or alkaline cleaner to remove dust and grease from the surface of the plastic body. The method according to claim 1,
The surface roughening is performed by mechanical abrasion, blasting to degrade the degreased surfaces of the plastic body to such an extent that the plastic body surface is deformed into hydrophilic porous surfaces. ), Chemical etching, and plasma etching, which increases the bonding force between the plastic body and the metal film formed later on the plastic body / RTI > The method according to claim 6,
The surface lubrication uses chemical etching to achieve surface deformation of the plastic body surface,
The use of a surface roughening agent comprising a mixed solution of chromium and sulfuric acid, persulfide, hydrogen peroxide, permanganate or sulfuric acid-based compounds, and
And the use of a strong oxidant produced by a diaphragm electrolysis system. ≪ RTI ID = 0.0 > 11. < / RTI > The method according to claim 1,
In the sensitization treatment, stannous chloride is mixed with tin ions, including Sn2 +, which is contained in the acidic solution, and then added to the roughened surface of the plastic body formed by surface lubrication Wherein the tin ions are absorbed on the roughened surface of the plastic body. The method according to claim 1,
In the activation treatment, palladium chloride is mixed with palladium ions, including Pd2 +, which is contained in an acidic solution, followed by subsequent formation of a thin metal film in a metal coating process via metal deposition Characterized in that active metal particles are formed in a continuous implantation reaction to promote the formation of active metal particles. The method according to claim 1,
In the metal coating process, a metal material is deposited on the surface of the pretreated plastic body to form a thin metal film; Characterized in that the deposited metal material is selected from the group consisting of nickel (Ni), cobalt (Co), palladium (Pd), tin (Sn), copper (Cu) Method of manufacturing a plastic 3D circuit. The method according to claim 1,
Said photoresist coating process comprising coating a liquid photoresist on the surface of a thin metal film to form a photoresist protective film; Wherein the liquid photoresist for forming the photoresist protective film is selected from the group consisting of a positive photoresist and a negative photoresist. delete delete delete The method according to claim 1,
The developing step is carried out by spraying a developing solution onto the photoresist protective film or by soaking the photoresist protective film in the developing solution;
The etching process is performed by spraying an etchant on a portion of the thin metal film or by soaking a portion of the thin metal film in the etchant;
Wherein the stripping step is performed by spraying a stripping agent onto the patterned photoresist protective film or by soaking the patterned photoresist protective film with the stripping liquid. The method according to claim 1,
The metal protective layer may be formed of a material selected from the group consisting of Ni, Cu, Au, Ag, Sn, Cr, Characterized in that the method comprises the steps of:

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