KR20090051633A - Built-in antenna, its manufacturing method and mobile communication terminal equipped with the same - Google Patents

Abstract

The present invention relates to a built-in antenna, a method for manufacturing the same, and a mobile communication terminal having the same. The built-in antenna has a metal film 12 formed by plating along a desired pattern on the surface of the synthetic resin film 11 or the substrate. The metal thin film 12 is composed of a printed layer printed on a film using ink for plating pretreatment, a first metal layer formed by chemical plating on the printed layer, and a second metal layer formed by electroplating on the first metal layer. Plating pre-treatment ink is cyclohexanone, butyl carbitle, toluene as solvent as the main component of polycarbonate, polystyrene, and acrylic rubber, which are non-halogen flame retardant resins, in a 180 ° C to 200 ° C atmosphere. It is stirred for 2 hours to 3 hours, and preferably, a conductive carbon and a binder for promoting adhesion are used as additives. The built-in antenna may be attached to an inner surface of a main body case of a mobile communication terminal such as a mobile phone or mounted as part of a circuit board in the main body. Therefore, it is very advantageous for miniaturization and weight reduction of the terminal, and in particular, it is possible to mass-produce several kinds of different antennas at once, which is economical and provides an effect of improving mobile phone performance in a fine pattern.

Built-in Antenna, Film, Substrate, Metal Thin Film, Plating, Printed Layer

Description

Built-in antenna, method for manufacturing the same, and mobile communication terminal having the same {INTERNAL ANTENNA, METHOD OF MANUFACTURING SAME, AND MOBILE COMMUNICATION TERMINAL HAVING SAME}

The present invention relates to an attachment-type antenna element, a method of manufacturing the same, and a mobile communication terminal having the antenna, which can be easily attached to a mobile phone case by forming an antenna pattern on a thin sheet or a synthetic resin substrate made of a non-conductive material.

In the past, antennas of mobile communication terminals such as mobile phones have been predominantly made of external protrusions such as helical antennas and whip antennas, but recently, in order to improve the miniaturization and design of the terminal body, and to improve the SAR (SAR) Planar Inverted-F Antenna (PIFA) with built-in flat panel structure mounted on the board, metal printed circuit board in PCB form, ceramic chip antenna, low-temperature co-fired ceramic (LTCC) antenna, and various built-in antennas in three-dimensional form Has been put into practical use.

As a form of such a built-in antenna, the Republic of Korea Patent Publication No. 10-0605421, 10-0735701, etc. is proposed to implement the antenna by forming a metal thin film pattern on a substrate of a non-conductive material.

In forming a metal thin film pattern on a substrate of such a non-conductive material, conventionally, a pattern is formed by a method of applying and drying a metal paste, followed by etching, and thus a thin copper plate is attached with an adhesive or manufactured by an insert mold method. In addition, the manufacturing process was complicated and a lot of defects occurred, there was a problem in that there is a limit in thinning.

On the contrary, Korean Patent Laid-Open Publication No. 10-2006-0040464 discloses a method of digging grooves of a predetermined depth along an antenna pattern on a substrate which is a non-conductive material, applying metal paste to the entire surface of the substrate including the grooves, and drying the metal paste. A method of forming an antenna pattern in which metal is embedded along the groove is proposed, but this method requires a mechanical processing process, which is difficult to mass-produce, and the dried metal face component is removed from the substrate groove during the processing process. There were still problems such as this occurring a lot.

Meanwhile, Korean Patent Publication No. 10-0573309 describes cutting a nonconductive synthetic resin film such as plastic, polycarbonate, and polyethylene resin along a desired antenna pattern, and manufacturing the antenna by plating it with metal and attaching it to an external case of a terminal. A solution is proposed. As such, in order to plate the surface of a non-conductive material such as a plastic product, a pretreatment process for imparting conductivity to a portion to be plated must be preceded. Pretreatment to impart conductivity generally includes etching and activation processes. Etching is the process of roughly scraping off the part to be plated to form holes for physically trapping precious metal particles such as palladium, and the activation step is for example colloid containing tin and palladium. After the product is immersed in the solution for a certain time, sulfuric acid treatment is used to capture the palladium metal particles in the holes formed by the etching. The palladium metal particles captured as described above provide conductivity to the surface of the product, and the surface of the product to which conductivity is provided can be plated by electroplating or electroless plating like the metal.

Conventionally, for example, ABS-based resin paints have been proposed as a pretreatment for plating to coat metal films on thermoplastic resins or thermosetting resins, but only some plastic products such as ABS resins have been proposed. It is effective, but the plating is not practical for other plastic products, such as polycarbonate, such that the catalytic metal capturing ability is not greatly improved and adhesion is weak due to easy peeling. Here, the adhesion can be improved by lengthening the above-described etching time to deepen the hole for physical capture of the catalytic metal, but there is a limit to the improvement, but rather, the surface of the product is excessively modified so that the original performance is improved. It is unpreferable etc. to fall.

SUMMARY OF THE INVENTION An object of the present invention is to provide an antenna which is plated with a synthetic resin film or a substrate which is a non-conductive material as a built-in type, which is advantageous for miniaturization and design improvement of a mobile communication terminal such as a mobile phone.

Another object of the present invention is to provide a method for manufacturing an antenna coated with a non-conductive resin film or a substrate as a built-in type, which is advantageous for miniaturization and design improvement of a mobile communication terminal such as a mobile phone.

Still another object of the present invention is to provide a mobile communication terminal having an antenna which is plated with a synthetic film or a substrate which is a non-conductive material as a built-in type, which is advantageous for miniaturization and design improvement of a mobile communication terminal such as a mobile phone.

The built-in antenna according to the present invention for achieving the above object is characterized by consisting of a non-conductive synthetic resin film or substrate, and a metal thin film formed by plating along a desired antenna pattern on one or both surfaces of the film or substrate.

Here, the metal thin film is a printed layer printed with ink for pretreatment for imparting conductivity along the pattern on the surface of the film or substrate, a first metal layer formed by chemical plating on the printed layer, and a second electroplated on the chemical plating layer. It consists of a metal layer.

Preferably, a backing layer may be provided with an adhesive layer that can be adhered to the installation.

The printing layer may be formed of a polycarbonate, polystyrene, acrylic rubber, or a resin containing at least one of them as a main ingredient, and cyclohexanone, butyl carbitle, and toluene as solvents. The ink may be printed by stirring for 3 hours to 3 hours, and preferably a conductive carbon and / or a binder for promoting adhesion may be further added to the ink.

In the manufacture of a built-in antenna consisting of a nonconductive synthetic resin film or substrate and a metal thin film formed by plating along a desired pattern on one or both surfaces of the film or substrate, degreasing the surface of the film or substrate. Printing a desired pattern with an ink as described in claims 4 to 7 on the surface of the degreased product to form and drying a printed layer, and immersing the printed layer in chromium and sulfuric acid solution to capture catalyst metal on the printed layer. Etching to form a hole, activating to trap a catalyst metal in the hole of the etched print layer, forming a first metal layer by chemical plating on the printed layer on which the catalyst metal is captured, Forming a second metal layer by plating; and preferably, the printing layer is formed to have a thickness of 0.4 μm to 0.6 μm.

The built-in antenna according to the present invention can be used by simply attaching to the inner surface of the outer case of the mobile communication terminal such as a mobile phone, for example, when the synthetic resin film is used as a material, and when using the synthetic resin substrate as a material of the printed circuit board. It can be used as a part. Therefore, the antenna device can be performed without increasing the volume of the terminal body, which is very advantageous for miniaturization and weight reduction of the terminal body, and enables the creation of various designs of the outer case.

The ink used in the built-in antenna according to the present invention has a strong adhesion to the surface of the non-conductive material and excellent capturing ability of the catalytic metal component after etching. Therefore, in the pretreatment step for the plating on the non-conductive material, the conductivity is easily given to enable subsequent plating. The present invention provides the effect of enabling the plating of a material which has been difficult by the conventional method such as polycarbonate with a particularly strong adhesive force.

The present invention also forms a large hole for capturing the catalytic metal by etching in the ink layer printed on the surface of the product, so that the metal thin film can be plated without damaging the product.

The present invention also prints a part of the product in a desired pattern, so that only the part can be pre-treated and then plated, so that it is possible to form an antenna metal thin film having a fine pattern, thereby improving antenna performance required by the terminal. Very effective.

The present invention can also plate various patterns and a large number of antenna elements in one plating bath at a time, which is suitable for mass production and thus can provide an inexpensive internal antenna.

Hereinafter, embodiments of the present invention will be described.

1 to 3 is a film antenna 10 made of a thin and flexible synthetic resin film. The film 11 which is a base material of the film antenna 10 is made of polycarbonate or polystyrene resin, for example. The metal thin film 12 is formed on one side of the film 11 by plating. The metal thin film 12 has feed parts 13 and 14 on one side thereof, and may be formed in various patterns including the line width and the length thereof according to the frequency characteristics required by the product to be used. An adhesive layer 15 is provided on the back surface of the film 11 shown in FIG. 2, and the adhesive layer 15 is covered with a release paper 16. That is, the release paper 16 can be removed and the adhesive layer 15 can be simply attached to the inner surface of the main body case 21 of the mobile phone 20 as shown in FIG. 3. The film-type antenna 10 attached to the inner surface of the main body case 21 is mounted on the circuit board 23 inside the main body case 21 by soldering a separate feed line 22 to the above-described power supply units 13 and 14. It may be connected to an antenna receiving circuit (not shown).

4 and 5 are substrate type antennas 30 made of a rigid synthetic resin substrate. Similarly, a metal thin film 32 is formed on one side of the synthetic resin substrate 31 as a base material of the substrate-type antenna 30 by plating, and the feed portions 33 and 34 of the metal thin film 32 are the substrate 31. It can extend to the side and back of the). The substrate-type antenna 30 can be simply mounted as part of the circuit board 23 mounted inside the main body case 21 of the mobile phone 20 as shown in FIG. 5, in which case the connector 24 is used. The extended feeders 33 and 34 can be simply connected to the circuit board 23.

The rapid thin films 12 and 32 formed by plating on one side or both sides of the film 11 or the substrate 31 described above are printed layers 2 printed on the respective substrates as shown in FIG. The first metal layer 6 formed of chemical plating on the metal sheet 6 and the second metal layer 7 formed of electroplating on the first metal layer 6 are formed.

The printing layer 2 is printed by, for example, stamping using a pretreatment ink for plating. The pretreatment ink stock solution for plating is 500 g to 600 g of cyclohexanone, 400 g to 500 g of butyl carbite, toluene with respect to 1,000 g of a mixed resin containing any one or any of non-halogen flame retardant resins, polystyrene and acrylic rubber as a main component. Using 200g to 400g, it can be formulated by stirring with a stirrer for 2 to 3 hours while heating and maintaining at 180 ℃ to 200 ℃.

Conductive carbon 100g ~ 200g may be preferably added to the ink stock solution. The conductive carbon enables the printing of fine patterns by preventing the static electricity by activating the conductivity of the printing layer, and ensuring sufficient etching time by improving the thickness and hardness of the printing layer on the product surface.

The ink stock solution may also be preferably added to the binder 50 to 100g to increase the adhesive strength to the surface of the product to be plated.

Hereinafter, the Example regarding an ink composition is described.

(Example 1)

1,000 g of polycarbonate, a non-halogen flame retardant resin, was used as a main raw material, and 500 g of cyclohexanone, 400 g of butyl carbitle, and 200 g of toluene were used as a solvent, followed by stirring for 2 to 3 hours while heating to 180 ° C to 200 ° C in a beaker. Stock solution composition. This ink could be used as a spray on the surface of the product to be plated, but it was not suitable for printing fine parts because of its poor adhesion. Therefore, 50 g of an adhesive promoting binder was added to form an ink suitable for stamping printing.

Experimental Example

An antenna substrate such as the film or the substrate described above was deposited on a liquid composition of 30 to 40 g / l to remove oil and water, and then the desired pattern was printed by stamping the stock solution of the ink according to Example 1, followed by chromic anhydride. Immerse in 500g / l, 200g / l sulfuric acid, 30g / l aqueous solution of chromium, and etch, immerse in palladium-tin colloidal solution to activate and sulfuric acid, and then primary copper plating with known chemical plating, followed by electroplating Secondary nickel plating was carried out as shown in FIGS. 7A to 7F.

In the drawings, reference numeral 1 denotes a polycarbonate substrate such as the above-described film or substrate, 2 a printed layer printed by stamping on the surface of the substrate 1, 3 a hole formed in the etching step of the printed layer, 4 printed in the activation step Palladium-tin compound trapped in the hole 3 of the layer 2, 5 is palladium metal particles having tin film removed in the sulfuric acid treatment step after activation, 6 is a copper plating layer as a first metal layer formed by chemical plating, and 7 is It is a nickel plating layer as a 2nd metal layer formed by electroplating.

As a result of the above experimental example, the thickness of the printing layer 2 was 0.4 to 0.5 µm, and the printing layer 2 was partially peeled off within 1 to 2 minutes of the etching time by the chromium sulfuric acid solution. After X-cutting at 5mm intervals, the test was performed after the office transparent adhesive tape (aka Scotch tape) was bonded and peeled off. As a result, each X-cutting plated layer was lifted from the surface of the product. That is, it could be plated without difficulty, but it was found that the adhesive strength with the product was slightly decreased.

(Example 2)

In the ink stock solution of Example 1 described above, 100 g of carbon was added, and the rest was performed in the same manner to form an ink and plating was performed as in the above experimental example. As a result, the thickness of the printed layer 2 was increased from 0.5 μm to 0.6 μm, and the etching time 3 to 4 minutes was secured to form the holes 3 large and deep. In addition, no lifting phenomenon of the X-cutting plating layer was found in the test under the same conditions.

(Example 3)

1,000 g of polystyrene was used as the main raw material, 500 g of cyclohexanone, 500 g of butyl carbitle, and 300 g of toluene were used as solvents, and 120 g of conductive carbon and 60 g of a binder for promoting adhesion were added to form an ink stock solution for stamping. Plating was performed.

(Example 4)

1,000 g of acrylic rubber is used as the main raw material, 600 g of cyclohexanone, 400 g of butyl carbitle, and 300 g of toluene are used as solvents, and 120 g of conductive carbon and 60 g of a binder for promoting adhesion are added to form a stamping ink stock solution. Plating was performed as well.

Experimental results of Examples 3 and 4 resulted in almost the same results as the experimental results of Example 2.

The above embodiment shows a preferred embodiment for the polycarbonate substrate. The present invention can of course be applied to all plastic substrates, including polycarbonate, and substrates made of glass or fiber.

1 is a perspective view showing a structure in which the built-in antenna according to the present invention formed on a flexible synthetic resin film.

2 is a cross-sectional view of the antenna shown in FIG.

Figure 3 is a schematic cross-sectional view showing a state in which the antenna shown in Figure 1 mounted on a known mobile phone.

4 is a perspective view showing a structure in which the built-in antenna according to the present invention is formed on a rigid synthetic resin substrate.

5 is a schematic cross-sectional view showing a state in which the antenna shown in FIG. 4 is mounted on a known cellular phone.

Figure 6 is a cross-sectional view showing a layer structure of the antenna metal thin film according to the present invention.

7a to 7f are schematic diagrams sequentially showing a manufacturing process of a built-in antenna according to the present invention.

Explanation of symbols on the main parts of the drawings

1: description

2: printing layer

6: Copper plating layer (1st metal layer)

7: Nickel plated layer (second metal layer)

10: film antenna

12,32: metal thin film

Claims (10)

A built-in antenna comprising a nonconductive synthetic resin film or substrate and a metal thin film formed by plating along a desired antenna pattern on one or both surfaces of the film or substrate. The printing layer of claim 1, wherein the metal thin film is printed on the surface of the film or substrate with a pretreatment ink for imparting conductivity along a pattern thereof, a first metal layer formed by chemical plating on the printing layer, and an electrical layer on the chemical plating layer. Built-in antenna, characterized in that consisting of a second metal layer formed by plating. The built-in antenna of claim 1 or 2, wherein an adhesive layer capable of being adhered to the installation is provided on the rear surface of the film. The method according to claim 2, wherein the printing layer is a polycarbonate, polystyrene, acrylic rubber, or any one or at least any one of the resin as a main raw material and cyclohexanone, butyl carbitle, toluene as a solvent 180 ℃ ~ 200 Built-in antenna, characterized in that printed in the ink was stirred for 2 to 3 hours in the atmosphere of ℃. The cyclohexanone 500 to 600 g, the butyl carbiter 500 to 600 g, with respect to 1,000 g of the resin according to claim 4, wherein the ink is based on any one or at least one of the above-described polycarbonate, polystyrene, and acryl rubber. Built-in antenna, characterized in that the mixture of toluene at a ratio of 200 ~ 400g. The built-in antenna of claim 5, wherein 100 g to 200 g of conductive carbon is added to the ink. The built-in antenna of claim 5, wherein 100 g to 200 g of conductive carbon and 50 g to 100 g of a binder for promoting adhesion are added to the ink. In manufacturing a built-in antenna consisting of a non-conductive synthetic resin film or substrate and a metal thin film formed by plating along a desired pattern on one or both surfaces of the film or substrate, Degreasing the surface of the film or substrate, printing a desired pattern with the ink as described in claims 4 to 7 on the surface of the degreased product to form and drying a print layer, and immersing the print layer in a chromium sulfate solution. Etching to form a hole for capturing the catalyst metal in the printed layer, activating the trapped catalyst metal in the hole of the etched print layer, and chemically plating the first metal layer on the printed layer in which the catalyst metal is trapped. And forming a second metal layer by electroplating on the first metal layer. The method of manufacturing an antenna according to claim 5, wherein the printed layer is 0.4 μm to 0.6 μm. A mobile communication comprising a non-conductive synthetic resin film or substrate and a built-in antenna composed of a metal thin film formed by plating along a desired pattern on one or both surfaces of the film or substrate and configured to communicate radio waves through the antenna. terminal.

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