JP2002368482A - Electromagnetic wave shielding member and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electromagnetic wave shielding member which is much more improved in visibility. SOLUTION: A colored conductive layer is deposited particularly to the rear surface. Namely, this electromagnetic wave shielding member is provided at a substrate 1 with the colored conductive layer 2 consisting of a nitride (metal nitride) with a metal having electric resistance of 10<-4> to 10<-6> Ω.cm. Moreover, it is also possible to form a two- to three-layer structure by providing a metal conductive layer 3 of the metal itself on the colored conductive layer and moreover by providing the colored conductive layer on the conductive layer 3. The metal nitride layer is formed by sputtering the metal in the nitrogen gas. Since this member has a higher visibility like the electromagnetic wave shielding property when it is processed to a transparent member having a mesh pattern, it can be used more effectively to an image display apparatus such as PDP or the like. When the colored conductive layer is the copper nitride, it can be used as the good conductive layer of dark green color which is effective for visibility.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved electromagnetic shielding member and a method of manufacturing the same. The transparent member obtained by forming the member into a net-like pattern is effectively used to shield electromagnetic waves emitted from an image display device such as a CRT or PDP.

[0002]

2. Description of the Related Art Electromagnetic waves emitted from various types of electronic information devices have adverse effects on the operation of other electronic devices and have adverse effects on the human body. Some are already in practical use. For example, as a familiar example, recently developed and commercialized PDPs (plasma displays) all prevent (suppress) electromagnetic waves that adversely affect the action of image display technology itself (since they are more likely to be emitted). It is actually the situation that measures are taken and sold.

The basic measure for preventing electromagnetic waves is to appropriately process a material having a lower electric resistance and mount it on an electronic information device. For example, in the case of a PDP, the following method is adopted. I have. A mesh-shaped conductive pattern made of copper or the like is provided on a (plastics) transparent substrate such as a PET film, and the surface of the conductive pattern is colored (black). This coloring is performed to enhance the visibility. Then, the entire surface is covered with a transparent base material (such as a glass plate) having a supporting property and integrated. The transparent plate obtained in this way is a transparent plate having a sufficient electromagnetic wave shielding property, and is used by mounting it on the front surface of the PDP screen.

[0004] For the patterning, for example, the following method is employed. In the case of a conductive pattern of copper, a transparent substrate (such as a PET film) is first chemically plated with copper and then electrolytically plated to provide a copper layer of a desired thickness. Next, this is meshed by photo-etching or the like. Finally, the surface (exposed portion) of the formed copper mesh pattern is colored. In addition, there is a method in which a mesh made of copper-plated fibers is adhered to the base material, and the mesh is held and fixed by the glass plate or the like. In the manufacture of these, sufficient consideration should be given to efficient electromagnetic shielding, transparency (brightness), satisfactory visibility (there is no tiredness for a long time), etc. Using a highly-reactive base material,
The specifications (width, height, pitch / opening ratio, etc.) of the pattern are determined.

The present inventors first provided a conductive thin film layer as an electromagnetic shielding transparent member by first sputtering a conductive material such as copper as a target in an inert gas such as argon. Then, after electroplating a layer of a thick conductive material such as copper on the layer, photo-etching (photolithography and etching with an acid) is performed to form a mesh pattern, and finally the upper layer is colored. Has filed several patent applications. This technology has been evaluated as excellent and has already been put to practical use in some cases.

[0006]

By the way, electromagnetic wave shielding
As the demand for solder members increases, the required quality and performance are also increasing. For example, with respect to PDPs, further improvement in visibility has been required. In order to respond to this demand for improvement, the present inventors have first started a new study of the effect of presently developing visibility (due to single-sided coloring of the surface). As a result, it was surprisingly found that the visibility was changed not only by coloring on the front surface but also by coloring on the back surface. The reason is that if there is a color with poor visibility on the back side, this color will be reflected on the screen, and as reflected light, it will be mixed with the original image color and appear in the eyes. Was.

Accordingly, the present invention and the like have started the research and development of a member for an electromagnetic wave shield having a conductive layer whose back surface is also colored based on the results of the above-mentioned study. As a result, a very effective solution was finally found, and the present invention was able to be reached.

[0008]

Means for Solving the Problems That is, the present invention relates to claim 1
As described in, the substrate (1)^-4-10 ^-6
Nitride with metal having electrical resistance of Ω · cm (nitride
That the colored conductive layer (2) of metal) is provided.
It is a member for electromagnetic wave shielding which is a feature. And further
The invention of a multi-layer configuration in which a laminating means is added to the invention.
Claims 2 and 3 are provided. Each of the above inventions
Claim 4 is also provided as a preferred invention.

Further, claims 5 to 7 are provided as inventions relating to a method of manufacturing the electromagnetic wave shielding member. Further, in each of these manufacturing methods, claim 8 is provided as a preferred invention. The present invention is as described above,
This will be described in more detail in the following embodiment.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, in particular, 10 ^-4 to 10 ^-6 Ω
The reason why a nitride with a metal having an electrical resistance of cm (that is, volume resistivity) (that is, metal nitride) was selected is as follows. However, the nitride includes a metal azide formed by a bond of three nitrogen atoms, but this is not included. The reason is lack of security.

First, the metal nitride compound itself is a good conductor. This means that electromagnetic wave shielding can be effectively performed even with a single layer alone, and when a thicker layer is desired with another metal layer, the metal nitride layer itself acts as a cathode electrode. Alternatively, the thickness can be immediately increased by electroplating.

Further, the metal nitride itself is a colored body colored gray-blue, brown, green-black, orange-red, etc. (for example, copper nitride is dark green, chromium nitride is Gray brown, nickel nitride is black, calcium nitride is black, aluminum nitride is gray blue, zinc nitride is green black). This means that a coloring step by chemical oxidation or the like, which is required with copper or the like, is not required for the expression of visibility, which is extremely effective in the manufacturing process and is also seen in a mesh pattern of copper or the like. In other words, there is no concern about a change in electric resistance caused by a separate chemical coloring. Here, as described later, as the color of the metal nitride, ionized nitrogen adopts any one of six oxidation states, so that the number of bonds between metal atoms and nitrogen atoms may not be constant. As a result, the color tone is slightly changed, but the color is also a change in the same color system, and this does not impede the present invention.

[0013] Further, dissolving (etching) with the same inorganic acid component as the simple metal. This is because, for example, in the case of a member for electromagnetic wave shielding in which the lower layer and the upper layer are formed of different metal layers, in many cases, two different etching liquids are used in forming a mesh pattern by a photo etching method. Although the etching operation is performed twice, the patterning can be performed by one etching under the same etching solution conditions. Further, this is because the adhesion to the substrate (1) on which the conductive layer is formed is also good. In general, the conductive metal layer is often oxidized in the air, so that some means for preventing rust is employed. However, it is also advantageous that the metal nitride layer is not required.

More specifically, the metal nitride 10
The metal of ⁻⁴ to 10 ⁻⁶ Ω · cm is a metal that is more positive than nitrogen and is selected from a group of metals ranging from 3 to 6 groups and 1 to 8 groups in the periodic table. However, some of them are not so desirable, so it is desirable to carefully consider them before actually selecting them. For example, as a less desirable metal, a metal which is easily hydrolyzed by moisture, for example, an alkali metal or a metal which lacks stability against heat or impact found in silver nitride or the like is not preferable. In addition, nitrides which are hardly dissolved in acids and which are too stable (this is also difficult to etch when formed into a mesh pattern by a photoetching method), such as titanium, niobium, which are close to nitrogen in the periodic table, Tantalum and the like are not preferred.

[0015] The above points, and the ease of manufacture and ease of handling. Preferred metals in consideration of colors effective for visual recognition and the like include the following. It is copper, calcium, zinc, aluminum, tin, chromium, nickel, cobalt. Further, among these, as described in claim 4, other metals except tin and cobalt are preferable.

According to the first aspect of the present invention, the metal nitride serves as a colored conductive layer (2) and is constituted by a single layer (2) on the surface of the substrate (1). First, the thickness of the layer is different depending on whether the single layer is used as the member for shielding the electromagnetic wave or in a case where the member is formed into a laminated structure. In other words, this is because a predetermined thickness is a necessary condition for effective electromagnetic wave shield development. It is desired to set the layer thickness so that the sheet resistance is at least about 10 ⁻² Ω / □ or less.

The substrate (1) is generally an electrically insulating ceramic, glass or plastic sheet-like material having a thickness of about 0.1 to 5 mm. Chemical resistance, physical properties, etc.) are determined by the use form and the like. For applications such as a PDP, in which the inside (image) is to be viewed through the substrate, the substrate must be as transparent as possible as the first condition. Therefore, in applications where transparency is not required, it may be semi-opaque.

In many cases, a plastic substrate is used. This includes, for example, polymethyl methacrylate,
Polystyrene or copolymer of styrene and acrylonitrile or methyl methacrylate, poly (4-methylpentene-1), polypropylene or amorphous by copolymerization of ethylene or the like with cyclic olefin monomer such as cyclopentene, norbonene, tetracyclododecane Molded substrates made of a crystalline cyclic olefin polymer, polyethylene terephthalate (PET), polyethylene naphthalate, polyarylate, polyether sulfone, polycarbonate, various liquid crystalline polymers, and the like.

On the other hand, in claim 2, the colored conductive layer made of metal nitride provided on the substrate (1) of claim 1 is used as a lower layer (2a), and a conductive layer made of the metal itself is further formed on this layer. An electromagnetic shielding member having two layers, provided as an upper layer (3). Here, the reason why the two-layer structure is provided is that there are also the following effects. With the metal nitride layer alone, it is difficult to obtain the conductive layer thickness required for efficient electromagnetic wave shielding easily and promptly in production, or the mesh pattern formed only with the metal nitride is required. If the electrical resistance is weak in terms of strength (resistance to impact, environmental atmosphere, etc.), or if the electrical resistance required by the metal nitride layer alone is slightly higher, the layers are laminated with a metal having a lower resistance. This is because there is a case where it is desired to cover

As described above, the layer thickness structure in the case of the two layers is appropriately determined within the range so as to secure at least the entire thickness (lower layer + upper layer) necessary for efficient electromagnetic shielding. However, it is preferable that the upper layer (3) is thicker than the lower layer (2a) because of the significance of providing the upper layer (3).

The combination of the material of the lower layer (2a) and the material of the upper layer (3) is generally the same as that of the metal nitride in the lower layer in terms of obtaining higher interlayer adhesion. It is desirable to use metal as the upper layer. However, because the lower layer contains nitrogen atoms, the interlayer adhesion is surprisingly good even in a different combination, so that a different combination is effective as long as a more effective action and effect can be obtained.

In the case of the two-layer structure, since the lower layer (2a) has already been provided with an effective color for visual recognition, the lower layer (2a) can be visually recognized from the back surface, but the upper layer (3) is visible. Does not have an effective color for Therefore, it is necessary to separately color the surface by some means. Taking only this point, it is the same as what is generally done, but since the condition of visual recognition from the back side of the main problem of the present invention has already been achieved, even if this conventional coloring means is adopted Thus, the present invention has been successfully achieved.

A third aspect of the present invention, which is provided as another laminated structure, is an invention comprising three layers in which the same layer as the lower layer (2a) is further laminated on the upper layer (3) in the second aspect. That is, the conductive metal layer of the upper layer (3) is
a), a lower (2a) conductive coloring layer made of metal nitride is sequentially laminated on both sides, and a lower layer (2b) and an upper layer (2c) are sequentially laminated. The effect of the electromagnetic wave shielding member having three layers is as follows. In other words, in the two layers of the second aspect, as described above, the metal surface layer of the upper layer (3) needs to be separately colored by some means in order to impart visibility. By laminating a colored conductive metal nitride layer on the upper layer (2c), the surface can be colored at once. Of course, since this upper metal nitride layer is also a good conductor, the upper layer thickness also contributes to the addition of the total thickness necessary for efficient electromagnetic wave shielding, so that the thickness of the intermediate layer (3a) is reduced accordingly. Although it can be changed as appropriate, in many cases the electromagnetic wave shielding is limited to two layers.
Since the required layer thickness is obtained for the field, the thickness of this upper layer is
The surface coloring function may be simply expressed and the thickness may be thinner than any of the other two layers.

The thickness of the three layers may be appropriately determined in order to ensure at least the total thickness (lower layer + intermediate layer + upper layer) necessary for efficient electromagnetic wave shielding. Due to the effect of laminating the metal conductive upper layer (3) described in claim 2, generally, the intermediate layer (3a) made of the same metal is set to be thicker than the (2b) layer and the (2c) layer on both sides. I do. The lower layer (2b) and the upper layer (2
As described above, c) generally means that the upper layer may be thin, but there is a slight difference in color tone, and it may be better to increase the thickness of the lower layer. You decide by looking. In addition, since the color density differs depending on the layer thickness even for the same color, when a transparent substrate is used, it is necessary to determine an appropriate layer thickness in consideration of this point so that a deep color effective for visual recognition is obtained.

The members for electromagnetic wave shielding provided in claims 1 to 3 have been described above. Next, a method for manufacturing each member will be described. In addition, each manufacturing method is provided as a preferable manufacturing mode, and the manufacturing is not limited thereto.

First, with respect to claim 1, which is the main invention, it is manufactured by the method described in claim 5. That is, sputtering is performed in the nitrogen gas with the metal itself as a target on the substrate (1) to form a film on the entire surface. When the metal is sputtered in a nitrogen gas, the metal changes to a metal nitride, which becomes a layer (2) having excellent conductivity in a deeply colored state and is fixedly adhered. It is thought to be. That is, first, the nitrogen gas is ionized (takes any one of -III, I, II, III, IV, and V oxidation states) in a plasma atmosphere. The metal atoms (which are also ionized) sputtered out by the sputtering react immediately with the nitrogen ions in the oxidized state to become the corresponding metal nitride. This is to say that a film is formed in close contact with the substrate as a colored metal nitride conductive layer.

It is desirable to set the sputtering conditions as follows. First, as a sputtering method, any of a commonly used conventional method and a magnetron sputtering method is used, and the latter method, which can perform sputtering at low temperature and high speed, is preferable. As for the nitrogen gas concentration at the time of sputtering, it is necessary to first remove the air in the sputtering chamber to make the gas atmosphere substantially 100%. This is because, if any oxygen is present, there is a risk that an inconvenient metal oxide may be formed. At that time, the nitrogen gas atmosphere concentration (pressure)
It must be at least at the concentration required to produce a predetermined thickness of metal nitride. Generally 1 to 10 ^-3
It is sufficient if Pa is maintained. As the target metal of 10 ⁻⁴ to 10 ⁻⁶ Ω · cm, an ingot having the highest possible purity is used. Further, the applied power of sputtering may be generally about 3 to 30 W / cm ² . The sputtering time is determined by layer thickness setting conditions including the intensity of the applied power and the distance between the sample and the target. It is desired that this be confirmed by preliminary testing in advance.

As for the substrate (1), at least its surface is previously degreased and cleaned. It is preferable to repeat the pretreatment by an electric (corona or glow) or chemical (oxidizing agent) method, particularly for a plastic substrate.
As described above, spattering using a metal nitride itself as a target also forms a metal nitride layer, but the adhesion to the substrate is slightly lacking (for unknown reasons). There is a tendency.

Next, a sixth aspect of the present invention will be described. The manufacturing method provided herein is, in addition to the manufacturing method of claim 5, manufactured by two steps of further laminating a conductive layer of the metal itself as an upper layer (3) due to the effect of the two layers. is there. That is, preferably, the metal nitride layer is formed by first performing sputtering in a nitrogen gas atmosphere on the substrate (1) whose surface has been pretreated by any means described above, using the metal itself as a target. Thus, a lower layer (2a) is formed. The sputtering conditions here are basically performed within the conditions described in claim 5.

Next, a conductive metal upper layer (3) made of the metal itself is laminated on the lower layer (2a). As the laminating means, any one of a method of sputtering the metal in argon gas and a method of electrolytic plating using the metal itself as a target can be adopted. First, the conditions in the case of performing the sputtering are basically performed in the first step except that the sputtering atmosphere is changed from a nitrogen gas to an argon gas (an inert gas) and the atmosphere concentration is changed. It is performed within the range of the condition. By changing to argon gas, the metal is stacked as a metal layer without any chemical change. Therefore, the argon gas must not contain an active gas such as air (oxygen). The gas concentration (pressure) may be about 1 to 10 ⁻³ Pa. still,
The use of argon gas here is merely for the reason that it is generally used as an effective inert gas, and therefore other inert gases that do not react with the metal at all under sputtering conditions may be used.

On the other hand, in the case of electrolytic plating, first, this method is capable of laminating a thicker metal layer (3) in a shorter time (as opposed to the sputtering). It should be noted that depending on the type of metal, it is not always said that all can be performed by electrolytic (electro) plating. Therefore, it is limited to a metal layer that can be effectively formed by the plating, and the difficult metal is dealt with by sputtering.

Metals on which the metal layer (3) can be formed by the electrolytic plating are copper, nickel, chromium, zinc, and tin which are generally used. As the electroplating conditions, the lower metal nitride layer serves as a cathode,
Basically, the plating is carried out in a plating bath containing a plating component which is generally used, and the bath temperature, pH, current density of the cathode and the anode at that time are also within the generally-used plating conditions.

The two-layer formation is carried out under the above-mentioned conditions. In particular, when this electrolytic plating method is used, it can be carried out by the following method. On the colored conductive layer (2a) made of the metal nitride formed in the first step, the metal itself is continuously sputtered to laminate a metal thin film layer. Accordingly, the sputtering time is shorter because the thickness is smaller than the film thickness formed in the second step. The film thickness is about 1/30 to 1/50 of the metal conductive thick film layer (3) provided in the second step. Finally, the electrolytic plating in the second step is performed to form a thick metal layer (3). This method is effective when the lower colored conductive layer (2a) made of metal nitride is not very resistant to moisture or the plating bath itself. That is, it is possible to perform the electrolytic plating safely without considering the moisture while protecting the colored conductive layer (2a) with a more stable single metal film.

Next, a seventh aspect of the present invention will be described. The manufacturing method provided here is manufactured by performing a third step of further laminating the colored conductive layer made of the metal nitride on the two metal conductive layers. That is, first, preferably, the substrate (1) whose surface has been pretreated by any of the above-described means is subjected to sputtering in a nitrogen gas with the metal itself as a target, and the colored conductive layer (2b) is made of metal nitride. Provide. Next, the intermediate layer (3a) is formed by sputtering or electrolytic plating in an argon gas with the metal itself as a target.
Is laminated. Finally, the colored conductive layer (2c) is laminated on the intermediate layer by using the metal itself as a target again in a nitrogen gas to perform sputtering in a nitrogen gas. Since the lower layer (2b) and the upper layer (2c) have already been colored, it is not necessary to separately perform a coloring step for the upper layer.

The conditions of the sputtering or electrolytic plating performed in each of the above steps, except for the thickness of the layer to be formed,
This is performed within the range described in 6. Also, in many cases, each layer is formed of a layer based on the same metal, but may be different.

Further, as the metal used in the manufacturing method according to any one of claims 5 to 7, any of copper, nickel and chromium, which can be used for either sputtering or electrolytic plating, is preferable. Further, copper or nickel is preferred because it has a lower electric resistance.

The electromagnetic shielding members thus obtained may be used as they are or appropriately processed depending on the application. Examples of the processing are CRT,
There is an electromagnetic shield transparent plate used for PDP. This is because first, the conductive surface of the member is changed to a mesh-shaped conductive pattern represented by a mesh. This processing method is generally performed by a photo-etching method (acid etching after photoengraving). In this member, in particular, for the acid etching, the same etching solution (for example, an aqueous solution of about 1 to 3% of ammonium persulfate) is used under the same conditions. This has the advantage that etching can be performed quickly and the mesh pattern of the original mask film is reproduced. (Conventionally, in the case of a heterogeneous laminate, etching can be performed with the same etching solution and under the same conditions. (Each layer was easily etched or lacked reproducibility. For this reason, etching was often performed under conditions suitable for the material of each layer.) In this processing method, an additive method generally called can be used. This is particularly the case when using the electrolytic plating method. That is, first, a thin layer made of metal nitride is formed on the substrate (1) (in some cases, a metal thin film layer is further laminated). Then, a photoresist is coated on the entire surface. (Mesh) A line pattern mask is brought into close contact with the substrate, exposed to ultraviolet light, and developed to dissolve and remove the pattern line portion. Then, electrolytic plating is performed on the exposed pattern wire portion. After the resist in the non-pattern line portion is removed, acid etching is finally performed. Since the lower layer of the non-pattern line portion is thinner than the electrolytic plating layer,
Since this portion is etched faster, the line pattern portion remains almost intact and a desired conductive pattern is obtained.

As for the reproducibility of the mesh pattern, for example, the electromagnetic wave from the PDP is screened by the mesh pattern.
The minimum required electrical resistance is 1Ω / □,
Since a mesh pattern having a line width of 10 μm and a pitch of 100 μm can be produced, a precise pattern can be obtained. In addition, higher transparency and visibility are sufficiently ensured, and an improved electromagnetic shielding material can be manufactured as compared with the conventional one.

Incidentally, when actually used for a PDP, the obtained transparent shield plate is further provided with a mesh conductive pattern surface (in the case of claim 2, a metal pattern surface of an upper layer separately). Is colored by an oxidation treatment or the like), but is protected by, for example, a transparent sheet (for example, a glass plate) by adhesive coating (at this time, the ground electrode is also pulled out from one end). Fixedly supported. This becomes an electromagnetic shield panel, which is mounted on the front of the screen of the PDP and used.

[0040]

The present invention will be described in more detail with reference to the following examples together with comparative examples. The surface electric resistance, the electric resistance of the conductive mesh, the electromagnetic wave shielding property, the transparency and the visibility in this example were measured as follows.

● Surface electrical resistance The conductive surface of the obtained film for transparent shielding was measured with a resistance measuring device “Loresta-EP, MCP-T” manufactured by Mitsubishi Chemical Corporation.
360 type ”(probe / ESP, applied voltage 10
0V), and is expressed as S · ρs.

Electric resistance of the conductive mesh pattern The conductive surface of the conductive mesh-patterned sample was measured for surface electric resistance (Ω / Ω) measured under the same conditions as the above-mentioned surface electric resistance.
□) and is represented by P · ρs. Note that S · ρs, P · ρ
s is a value measured at 15 different positions and averaged.

Electromagnetic Wave Shielding The electromagnetic wave attenuation obtained by measuring a sample formed into a conductive mesh pattern in a frequency range of 0 to 1 GHz using a measuring device manufactured by Kansai Electronics Industry Promotion Center. Value shown in (dB) (value generally called KEC method).

● Transparency A turbidity meter “Type NDH-20D” manufactured by Nippon Denshoku Industries Co., Ltd. (JIS)
K7105 / 1981).

● Visibility A transparent glass plate (air-cooled) (thickness: 3.2 mm) was bonded and fixed to the conductive surface of the conductive mesh-patterned sample through a coreless double-sided adhesive. The image was actually mounted on a PDP screen and observed by three persons, and the difference from the comparative sample was observed. The comparison here was performed by sensuously knowing the sharpness (easiness of seeing) that was instantaneously felt when viewed, and the tiredness of the eyes when the user continued watching for a long time. This check was performed on both surfaces of the sample (observation from the front side of the glass plate and observation from the back side of the PET film). In addition, as a comparative sample, a single-sided colored electromagnetic wave sealing plate manufactured in Example 1 described in Japanese Patent Application Laid-Open No. 2000-156591 filed by the present applicant (that is, the back surface has a red color of copper itself) The surface was a black pattern colored with copper oxide).

(Example 1) (Example of Claim 1) First, a thickness of 125.0 μm pretreated by single-sided glow discharge.
m, a stretched PET film 1 (Tt = 90%) having a size of 500 × 1000 mm was sputtered under the following conditions to uniformly deposit a conductive colored layer 2 of copper nitride. ◎ Equipment ・ ・ Magnetron sputtering 、 ◎ Target ・ ・ Pure copper ingot (Purity 99.99
%), ◎ Gas atmosphere: First, the vacuum chamber was evacuated to 10 ⁻⁴ Pa, then dry nitrogen gas with a purity of 99.99% was gradually introduced and replaced to maintain the internal pressure at 10 ⁻² Pa. ◎ Distance between target and PET film 1 ··· 130
mm, ◎ Input power: 10 W / cm ² (DC), ◎ Vacuum chamber temperature: 80 ° C, ◎ Sputtering time: 100 minutes.

On the film-formed surface obtained under the above conditions, a layer 2 of copper nitride exhibiting a dark green (dark green) close to black was formed. S · ρs is (1 ± 0.2) × 10
⁻² Ω / □. The electromagnetic shielding property is 0.1
45dB at GHz, 46dB at 0.5GHz, 1GHz
Was 51 dB. The adhesion of the layer was tested with Cello Tape (registered trademark) (three peel tests).
There was no peeling at all. This example is illustrated in the sectional view of FIG. 1 for reference.

(Example 2) (Example of claim 2) Sputtering is performed under the same conditions as in Example 1 except that the sputtering time is changed to 30 seconds, and first, a copper nitride layer 2a as a lower layer is uniformly formed on the entire surface. A film was formed. In this case, the color of the layer 2a was dark green as in Example 1. The vacuum chamber was thoroughly cleaned and prepared for the next operation.

Then, a conductive copper layer 3 was laminated on the copper nitride layer of the lower layer 2a under the following conditions. ◎ The apparatus and target are the same as in Example 1. ◎ Gas atmosphere: First, the vacuum chamber is evacuated to 10 ⁻⁴ Pa, and then dry argon gas of 99.99% purity is gradually introduced and replaced. Then, the internal pressure was maintained at 10 ⁻² Pa. ◎ Distance between target and PET film 1 ··· 130
mm, input power: 15 W / cm ² (DC), vacuum chamber temperature: 80 ° C., sputtering time: 10 minutes.

The color of the upper layer 3 obtained under the above conditions is red,
It was exactly copper itself. That is, the PET film was dark green on the back side and red on the front side. When S · ρs of this product was measured, it was (1.4 ± 0.2) × 10 ⁻² Ω / □.
Met. The electromagnetic shielding property is 4 GHz at 0.1 GHz.
4dB, 45dB at 0.5GHz, 49dB at 1GHz
Met. In addition, the adhesion of the layer is determined by cello tape (registered trademark).
(Three peel tests), there was no peeling from the lower layer 2a. This example is illustrated in the sectional view of FIG. 2 for reference.

(Example 3) (Example of claim 3) Under the same conditions as in Example 2, first, copper was sputtered in nitrogen gas, and then copper was sputtered in argon gas to form a nitride. A conductive coloring layer 2b (lower layer) made of copper and an intermediate layer 3a made of copper were sequentially laminated thereon. Finally, the conductive colored layer 2c made of copper nitride was sputtered on the intermediate layer under the same conditions as the lower layer to complete the process. The resulting product was a dark green PET film as a whole, and the S · ρs was measured.
0.2) × 10 ⁻² Ω / □. Electromagnetic shielding is 44 dB at 0.1 GHz and 45 d at 0.5 GHz.
B, 49 dB at 1 GHz. The adhesion of the three layers was tested using Cello Tape (registered trademark) (three peel tests), but no peeling was observed from any part. This example is illustrated in the sectional view of FIG. 3 for reference.

(Embodiment 4) (Claim 3 based on nickel)
Example) First, using the same PET film as in Example 1, sputtering was performed under the following conditions, and a conductive coloring layer of nickel nitride as a lower layer was uniformly formed on the entire surface. ◎ Equipment ・ ・ Magnetron sputtering 、 ◎ Target ・ ・ Pure nickel ingot (Purity 99.9
9%), ◎ Gas atmosphere: First, the vacuum chamber was evacuated to 10 ⁻⁴ Pa, then dry nitrogen gas with a purity of 99.99% was gradually introduced and replaced to maintain the internal pressure at 10 ⁻² Pa. did. ◎ Distance between the target and the PET film 1 70 m
m, ◎ Input power: 3W / cm ² (DC), ◎ Vacuum chamber temperature: 100 ° C, ◎ Sputtering time: 5 minutes.

The film formation surface obtained under the above conditions exhibited a slightly grayish black color, and a nickel nitride lower layer was formed.
The S · ρs of this is (6 ± 0.2) × 10 ⁻¹ Ω /
Was □

Next, the vacuum was released once, the vacuum chamber was sufficiently cleaned, and a nickel conductive layer serving as an intermediate layer was laminated on the nickel nitride lower layer under the following conditions. That is, during the lower layer forming condition, the gas atmosphere is changed to dry argon gas (purity 9).
(9.99%), except that the sputtering time was changed to 10 minutes. The obtained intermediate layer had a silvery white color, and a nickel intermediate layer was laminated. When S · ρs of this product was measured, it was (5 ± 0.2) ×
10 ⁻² Ω / □.

Finally, on the intermediate layer, sputtering was performed under the same conditions as those for forming the lower layer, and a conductive coloring layer made of nickel nitride as an upper layer was formed. The silver white of the intermediate layer was covered with a gray-black nickel nitride layer of the same color as that of the lower layer, and the whole became a gray-black PET film. When S · ρs of this product was measured,
(4.7 ± 0.2) × 10 ⁻² Ω / □. The electromagnetic shielding property is 42 dB and 0.5 GH at 0.1 GHz.
It was 43 dB at z and 46 dB at 1 GHz. In addition, the adhesion of the entire layer was tested with Cello Tape (registered trademark) (3.
Peeling test), there was no peeling from any of them.

(Embodiment 5) First, under the same conditions as in Embodiment 2,
After the copper nitride layer as a lower layer was provided on the PET film, a copper thin film layer was laminated on the lower layer. However, the sputtering time of the copper thin film layer was 2 minutes. The total thickness of both layers up to here was about 0.1 μm.

Next, copper electroplating was performed using the above-mentioned two-layer (conductive) PET film as a cathode and a pure copper plate as an anode to laminate the plated copper layer on the copper thin film layer. ◎ Plating bath ・ ・ General electrolytic bath mainly composed of copper sulfate and sulfuric acid ◎ Cathode current density ・ 3A / dm ² ◎ Plating time ・ ・ 6 minutes ◎ Plating bath temperature ・ ・ 30 ℃.

After the above-mentioned electrolytic plating, the plate was thoroughly washed with water and dried, and when the total thickness was measured, it was 129.1 μm. Therefore, the thickness of the plated copper layer is about 4 μm. The surface was red, and S · ρs was (6 ± 0.3) × 10 ⁻³ Ω / □.

Finally, a copper nitride layer was laminated on the copper plating intermediate layer under the same sputtering conditions as the lower layer, and the process was completed. When S · ρs on the surface of the copper nitride layer was measured, it was (5.9 ± 0.2) × 10 ⁻³ Ω / □. Electromagnetic shielding is 44 dB at 0.1 GHz and 0.5 dB.
It was 47 dB at 1 GHz and 51 dB at 1 GHz. still,
The adhesive strength of the entire layer was tested using Cello Tape (registered trademark) (three peeling tests), and none of the layers was peeled off.

(Reference Example 1) (Production Example in Case of Mesh Conduction Pattern) Using the PET film for electromagnetic wave shielding (cut to 450 × 900 mm) obtained in Example 5 above, first, the following conditions were used. After photolithography was performed to develop a mesh pattern, acid etching was performed to change to a corresponding mesh pattern. First, a positive photoresist was applied to the copper nitride layer on the upper surface of the film by a roll coater to a thickness of 2 μm and dried. Then, a positive mask film (a lattice pattern having a line width of 17 μm and a pitch of 300 μm) is vacuum-contacted to the photosensitive surface and exposed (ultraviolet light, exposure intensity 13
0 mJ / cm ² ). Next, with an alkaline developer,
The exposed portion was dissolved and removed (the resist film of the unexposed line portion remained, and the exposed non-linear portion was dissolved and removed).

Then, an etching solution containing a 5% by weight aqueous solution of ammonium persulfate as a main component and adjusted to a temperature of 30 ° C. is sprayed uniformly onto the developing surface of the developed PET film for 3 minutes. The non-linear portion was removed by etching. Immediately after etching, wash thoroughly with water,
Subsequently, the film was immersed in a 5% by weight aqueous solution of caustic soda for 50 seconds to remove and remove the remaining resist film.

The obtained conductive pattern on the PET film surface was observed with a magnifying microscope (500 times), and the reproducibility of the lattice pattern was checked. It was reproduced almost exactly as it was. When the line width was measured, it was 15 ± 0.2 μm. When the color of the pattern was confirmed from the front and back surfaces, it was also confirmed that the pattern exhibited a dark green color. The measured transparency Tt was 81%, and P · ρs was (1.2 ± 0.1) × 1.
0 ^-1 Ω / □. The aperture ratio of the pattern was 90% when calculated from an actually measured reproduction mesh.

(Reference Example 2) The surface of the mesh-patterned PET film obtained in Reference Example 1 and a glass plate (thickness 3.2 mm, Tc = 94%, air-cooled reinforced plate) were attached without a core. Adhesive bonding with double-sided adhesive film, electromagnetic wave shielding for PDP
I made a metal plate. At the time of this bonding, preliminary bonding was performed while pressing with a rolling beforehand, and finally complete bonding was performed under a pressurized environment. This is effective as a method for preventing air bubbles from entering the bonding surface. An earth electrode was provided at the end of the film, and a lead wire was drawn out and prepared for use.

When the electromagnetic shielding property was measured, it was 36 dB at 0.1 GHz and 37 dB at 0.5 GHz.
B, 41 dB at 1 GHz. Further, the Tt of this electromagnetic wave shield plate was measured to be 79%, confirming that there was no problem in transparency.

Then, the visibility is checked in the following order.
Compared. First, the image was mounted on the comparative sample with the glass surface facing the front, and the image was viewed. The sharpness felt instantaneously at that time was memorized, and then immediately detached and replaced with the sample of this example, and similarly viewed from the glass surface side. As a result, the comparative sample was turbid and felt hard to see, but in the case of the sample of this example, a clear and easy-to-view image could be captured.

Next, observation from the back side (PET film substrate side) was performed in the same manner, and the visibility was compared. As a result, in the sample of the present example, the same visibility as that observed from the glass surface side was confirmed, but in the comparative sample, the result was almost the same as that in the above case (it is considered to be unfavorable for the visual effect). It can be seen that the reddish color is not good regardless of the observation from the front or the back). Thereafter, the feeling of eye fatigue due to long-term observation was also compared. As compared with the feeling of fatigue (eyelid condition) in the comparative sample, it was extremely small in the present sample.

[0067] The generation confirmation of the copper nitride layer and the nickel nitride layer is performed by ULVAC (ULVAC-PHI).
Was performed by elemental analysis using an ESCA (X-ray photoelectron spectroscopy) 5400-type measuring instrument manufactured by Toshiba Corporation. Alternatively, the ammonium persulfate solution of the etching solution used in Reference Example 1 can be similarly etched using, for example, a hydrogen peroxide-sulfuric acid aqueous solution or a ferric chloride aqueous solution.

[0068]

Since the present invention is configured as described above, the following effects can be obtained.

In the conductive metal layer constituting the member for electromagnetic wave shielding, a colored and highly conductive metal nitride is used at least for the lower layer, so that the visibility is improved without impairing the good conductivity. You can now improve.

By forming a metal nitride layer on the upper layer in the same manner, the coloring step conventionally provided as a separate step is no longer required. As a result, there is no concern about a change in conductivity due to the conventional coloring, and the device can be manufactured with more stable manufacturing quality.

Since it has a deeply colored layer that is easy to see from both the front and back sides, it is possible to use it without worrying about the front and back sides. With the development of the electromagnetic wave shielding member having the above characteristics, the visibility required for a PDP or the like has been improved, and its use has become more advantageous.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a first embodiment.

FIG. 2 is a sectional view of a second embodiment.

FIG. 3 is a cross-sectional view of a third embodiment.

[Explanation of symbols]

 1 PET film (transparent substrate) 2, 2a, 2b, 2c (dark green) copper nitride layer 3, 3a (red) copper layer

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4K044 AA16 AB02 AB10 BA02 BA06 BA10 BA11 BB04 BB15 BB16 BC09 CA13 CA18 5E321 AA21 BB23 BB41 GG05 GH01

Claims (8)

[Claims] The substrate (1) has a ^{thickness of} 10 ^-4 to 10 ^-6 Ω · c.
nitride with a metal having an electrical resistance of m (metal nitride)
2. A member for shielding electromagnetic waves, comprising a colored conductive layer (2) according to claim 1. 2. A substrate (1) wherein a colored conductive layer (2) made of a metal nitride is sequentially laminated on a lower layer (2a), and a conductive layer made of the metal itself is laminated on an upper layer (3). For electromagnetic shielding. 3. A substrate (1) in which the conductive layer of the metal itself is an intermediate layer (3a), and the colored conductive layer of the metal nitride is sequentially laminated on both sides (2b, 2c). A member for shielding electromagnetic waves, characterized in that: 4. The method according to claim 1, wherein said metal is one of copper, nickel, chromium, aluminum, calcium and zinc.
4. The member for shielding electromagnetic waves according to any one of claims 1 to 3. 5. The method according to claim 1, wherein the metal itself is bonded to a substrate (1).
2. The method for producing a member for electromagnetic wave shielding according to claim 1, wherein a sputtering is performed in a nitrogen gas as a get to form a colored conductive layer (2) by a metal nitride layer. 6. The following (A) to (B) with respect to the substrate (1).
The method according to claim 2, wherein the steps described in (1) are sequentially performed. (A) a first step of forming a colored conductive layer of metal nitride as a lower layer (2a) by sputtering in a nitrogen gas with the metal itself as a target, and (B) argon with the metal itself as a target. A second step of forming a conductive upper layer (3) by the metal itself by performing sputtering or electrolytic plating in a gas. 7. The following (C) to (E) with respect to the substrate (1):
4. The method according to claim 3, wherein each of the steps is performed sequentially. (C)
A first step of forming a colored conductive layer of metal nitride as a lower layer (2b) by sputtering in a nitrogen gas with the metal itself as a target, and (D) in an argon gas with the metal itself as a target. By performing sputtering or electrolytic plating, the conductive intermediate layer (3
a) a second step of forming a), and (E) a third step of forming a colored conductive layer of metal nitride as the upper layer (2c) by performing sputtering in nitrogen gas using the metal itself as a target. 8. The method according to claim 5, wherein the metal is one of copper, nickel and chromium.