WO2008099527A1

WO2008099527A1 - Flexible circuit board and process for producing the same

Info

Publication number: WO2008099527A1
Application number: PCT/JP2007/068314
Authority: WO
Inventors: Tsunemi Oiwa; Masatosi Kondo
Original assignee: Hyomen Shori System Co, Ltd.
Priority date: 2007-02-16
Filing date: 2007-09-10
Publication date: 2008-08-21
Also published as: TW200836609A

Abstract

A flexible circuit board of high reliability that excels in the adherence of a copper based metal layer, permitting microetching. Resin film (1) on its surface is provided with silicon nitride layer (2) according to sputtering technique wherein nitrogen is contained in an amount of 0.5 to 1.33 in terms of equivalent to silicon, and further provided with copper based metal layer (3). Accordingly, the adherence of the copper based metal layer (3) is high. Further, as the silicon nitride layer (2) is an insulator, etching thereof is not needed with the copper based metal layer only to be etched, so that side etching is less likely to occur, allowing execution of microetching. Still further, even in the event of penetration of moisture or oxygen from the side of resin film (1) at high temperature, it would be blocked by the silicon nitride layer (2), so that any oxidation or adherence deterioration of the copper based metal layer (3) would not occur to thereby provide flexible circuit board (6) of high reliability.

Description

Patent application title: FLEXIBLE CIRCUIT BOARD AND METHOD OF MANUFACTURING THE SAME

The present invention relates to a flexible circuit board in which a copper-based metal layer is formed on the surface of a resin film such as polyimide film, for example, and a method of manufacturing the same. In recent years, with the miniaturization and high performance of electronic devices, the density of mounting technology that interfaces with components such as elements and boards has been increased, and the corresponding flexible printed circuit (FPC) has been developed. High definition is required.

As a method of producing a flexible printed circuit board, which is one of such circuit boards, a copper film is formed on a heat resistant film, the copper film is pattern etched, and an IC or the like is bonded to form a flexible circuit. There is a way to make the board.

With regard to the flexible circuit board used for this circuit, a method of laminating copper foil and polyimide film, and a nickel-chromium alloy sputtered film for giving adhesion on polyimide film. In general, a copper sputtered film is formed to impart conductivity and a copper film is formed thereon by a plating method. Of these two, the sputtering method described later has characteristics such as the ability to thin copper, and is promising from the point of future prospects.

However, as the thickness of the copper film becomes thinner, the Since the sputtered film of nickel-chromium alloy for imparting adhesion is difficult to etch, there is a problem that side etching progresses and fine patterns with a line width of 35 μm or less can not be formed. Furthermore, in the storage test at high temperature, the permeation of moisture and oxygen from the polyimide film side causes the nickel-chromium alloy to be oxidized and the adhesion to be lowered, which is a problem in terms of reliability.

In order to solve these problems, in place of the nickel-chromium alloy, another metal such as, for example, nickel-copper alloy has been proposed (Patent Document 1 below). However, although the method of Patent Document 1 improves in terms of fine patterns, there are problems with reliability and the like.

As a countermeasure against this, there has been proposed a method of forming an oxide on the polyimide surface opposite to the copper sputtered film (Patent Documents 1 and 2 below). However, these methods increase the number of film formation processes and complicate the apparatus, leading to a cost increase.

As a countermeasure against this, oxides such as silicon oxide and zirconium oxide have been proposed at the interface between the film and copper sputtering (Patent Document 3 below). However, this method does not have sufficient adhesion.

Therefore, use a compound film of nitrogen and a metal such as silicon, chromium and nickel, and a film containing less nitrogen on the copper side to obtain adhesion with copper, and improve adhesion and prevent moisture permeation. It has been proposed to do this (patent document 4 below). Further, it has been proposed to form a copper oxynitride layer instead of a nitride (Patent Document 5 below).

Patent Document 1 Patent No. 3 4 4 7 0 7

Patent Document 2 Japanese Patent Application Laid-Open No. 2 0 0 5-2 1 9 2 5 9

Patent Document 3 Japanese Patent Application Laid-Open No. 1 1 1 3 3 7 2 9

Patent Document 4 Japanese Patent Application Laid-Open No. 2000-05-3 4 7 4 3 8 Patent Document 5 Japanese Patent Application Laid-Open No. 2005-0554 25 9 Disclosure of the Invention

Problems that Invention is to Solve

However, the compound film with nitrogen on the polyimide side formed by the method of Patent Document 4 has a considerably large film thickness because the nitriding reaction is not sufficiently promoted and it does not form a stoichiometric nitride. There is a problem that sufficient adhesion can not be obtained unless it is done. Furthermore, since the chemical reaction can not be promoted even if nitrogen gas is introduced in vacuum deposition, silicon and tantalum etc. do not become nitrides, and only films close to the metallic state can be obtained, thus improving the reliability. I can not do it. In addition, the presence of metal layers such as silicon, nickel, chromium and the like to improve adhesion results in that etching by post-process etching becomes difficult, and side etching occurs during micropatterning. There is still a problem that On the other hand, even with devices, the number of targets increases, so there are problems such as the devices becoming larger. Further, the method of Patent Document 5 mentioned above is not sufficient in terms of the adhesion to the polyimide film.

The present invention has been made in view of these circumstances, and an object thereof is to provide a flexible circuit board which is excellent in adhesion of a copper-based metal layer, is capable of fine etching, and has high reliability, and a method of manufacturing the same. . Means to solve the problem

In order to achieve the above object, in the flexible circuit board of the present invention, a silicon nitride layer is formed on the surface of a resin film by a sputtering method in which nitrogen is contained in an equivalent amount of 0.5 to 1.33 to silicon. The first point is that a copper-based metal layer is further formed. In order to achieve the above object, the flexible circuit board of the present invention has a silicon oxide layer formed by a sputtering method in which nitrogen is contained in an equivalent amount of 0.3 to 1.1 on the surface of a resin film relative to silicon. And the formation of a copper-based metal layer is referred to as the second aspect.

In order to achieve the above object, the flexible circuit board of the present invention has a silicon nitride layer or a silicon oxynitride layer formed by a sputtering method on the surface of a resin film, and is further selected from silicon, aluminum and nickel. A third aspect of the present invention is that a metal film having a thickness of 0.5 to 5 nm is formed, and a copper-based metal layer is further formed.

In addition, in order to achieve the above object, according to the method for producing a flexible circuit board of the present invention, a silicon nitride layer containing 0.5 to 1.33 equivalents of nitrogen relative to silicon on the surface of the resin film. The first summary is to provide a silicon nitride sputter process for forming a copper-based metal layer and a copper-based metal formation process for forming a copper-based metal layer.

In addition, in order to achieve the above object, according to the method for producing a flexible circuit board of the present invention, a silicon oxynitride layer containing nitrogen in an equivalent amount of 0.3 to 1.1 with respect to silicon on the surface of a resin film. According to a second aspect of the present invention, the method further comprises the steps of forming a silicon oxynitride sputtering step of forming a copper-based metal layer and forming a copper-based metal layer of a copper-based metal layer.

Further, in order to achieve the above object, according to the method for producing a flexible circuit board of the present invention, a first sputtering step of forming a silicon nitride layer or a silicon oxynitride layer by a sputtering method on the surface of a resin film And a second sputtering process for forming a metal film having a thickness of 0.5 to 5 nm selected from Ge, aluminum, and nickel, and a copper-based metal forming process for forming a copper-based metal layer. As the third summary. Effect of the invention

That is, according to the first aspect of the present invention, a silicon nitride layer is formed on a surface of a resin film by a sputtering method in which nitrogen is contained in an equivalent amount of 0.5 to 1.3 with respect to silicon. A layer was formed. Thus, the adhesion of the copper-based metal layer is improved by forming the silicon nitride layer containing 0.5 to 1.33 equivalent amounts of nitrogen as the intermediate layer. Furthermore, since the silicon nitride layer is an insulator, there is no need for etching, and only the copper-based metal layer needs to be etched, so that fine etching can be performed without much side etching. In addition, even if moisture or oxygen penetrates from the resin film side under high temperature, it is blocked by the silicon nitride layer, oxidation of the copper-based metal layer does not occur and adhesion strength is not generated, and the reliability is also excellent. It becomes a flexible circuit board.

That is, according to the second aspect of the present invention, a silicon oxynitride layer is formed on a surface of a resin film by a sputtering method in which nitrogen is contained in an equivalent amount of 0.3 to 1.1 with respect to silicon. A layer was formed. Thus, the adhesion of the copper-based metal layer is improved by forming the silicon oxynitride layer containing 0.3 to 1.1 of nitrogen equivalently as the intermediate layer. Furthermore, since the silicon oxynitride layer does not need to be etched because it is an insulator, it is sufficient to etch only the copper-based metal layer, so that it is possible to perform fine etching without much side etching. In addition, even if moisture or oxygen penetrates from the resin film side at high temperature, it is blocked by the silicon nitride layer and oxidation of the copper-based metal layer does not occur and adhesion is not deteriorated. It is an excellent flexible circuit board.

In the third aspect of the present invention, a silicon nitride layer or a silicon oxynitride layer is formed on a surface of a resin film by a sputtering method, and a thickness selected from silicon, aluminum and nickel is further provided. Form a metal film of ~ 5 nm, Furthermore, a copper-based metal layer was formed. Thus, by forming a silicon nitride layer or a silicon oxynitride layer and a metal film having a thickness of 0.5 to 5 nm selected from silicon, aluminum, and nickel as an intermediate layer, Adhesion of the metal layer is good. Furthermore, since the silicon nitride layer or the silicon oxynitride layer does not need to be etched because it is an insulator, it is only necessary to etch only a thin metal film such as a thin silicon and a copper-based metal layer. Fine etching is possible without much occurrence of In addition, even if moisture or oxygen penetrates from the resin film side under high temperature, it is blocked by the silicon nitride layer or the silicon oxynitride layer, and oxidation of the copper-based metal layer and adhesion decrease. The flexible circuit board has excellent reliability.

In the first method for manufacturing a flexible circuit board according to the present invention, the silicon nitride sputtering step is carried out while applying a high-frequency bias voltage to an electrode roll for sending a resin film in a region facing a target. Since the electrode roll on the resin film side is shifted to the apparent negative potential side with respect to the surroundings due to the high frequency bias voltage, a sufficient amount of nitrogen in the silicon nitride can be secured and the adhesion of the silicon nitride layer is also significantly improves.

In the second method for manufacturing a flexible circuit board according to the present invention, the above-mentioned oxynitride silicon sputtering process is carried out while applying a high frequency bias voltage to an electrode roll for sending a resin film in a region facing a target. In this case, the electrode roll on the resin film side is apparently shifted to the negative potential side with respect to the surrounding area due to the high frequency bias voltage, so that sufficient amount of nitrogen in the silicon nitride can be secured and adhesion of the silicon nitride layer The power also improves significantly.

In the third method for manufacturing a flexible circuit board of the present invention, the second method described above When the sputtering process is performed while applying a high frequency bias voltage to the electrode roll that sends the resin film in the region facing the target, the electrode roll on the resin film side is against the surrounding due to the high frequency bias voltage. By apparently shifting to the negative potential side, the adhesion of the metal film is also greatly improved. Brief description of the drawings

FIG. 1 is a cross-sectional view showing a flexible circuit board according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a flexible circuit board according to a second embodiment of the present invention.

Fig. 3 is a block diagram showing a sputtering apparatus.

Fig. 4 is a block diagram showing a plating apparatus.

Fig. 5 is a block diagram showing a second example of the sputtering apparatus.

Fig. 6 is a block diagram showing a third example of the sputtering apparatus.

Fig. 7 is a block diagram showing a fourth example of the sputtering apparatus.

FIG. 8 is a cross-sectional view showing a flexible circuit board according to another embodiment of the present invention.

FIG. 9 is a cross-sectional view showing a flexible circuit board according to a seventh embodiment of the present invention.

Fig. 10 is a block diagram showing a sputtering apparatus.

FIG. 11 is a cross-sectional view showing a flexible circuit board according to another embodiment of the present invention.

Explanation of sign

1: Resin film

1 a: film with seed layer 2 a: Silicon nitride layer

2 b: Silicon oxynitride layer

3: Copper-based metal layer

3 a: Copper film

4: Copper sputtered film

5: Copper plating layer

6: Flexible circuit board

7: Metal film

0: Plasma chamber

1: 1st Snotto Room

2: 2nd Suno ⁰ Room

3: Supply roll

: Tottori 'Ronole

5: Plasma processing equipment

: First entry

7: second role

: Silicon target

: Copper target

: High frequency power supply

1: DC power supply,

1 a: DC power supply

b: DC power supply,

: High frequency power supply

Common Renore

: Metal target

: Mezusa tank 2 6: Washing tank

2 7: Drying tank

2 8: Supply roll

2 9: One way

3 0: DC power supply

3 1: Anode

3 2: Cathode roll

3 3: Copper supply part

3 4: Copper wire

3 5: Crucible

3 6: Heater

3 7; landing mode BEST MODE FOR CARRYING OUT THE INVENTION

Next, the best mode for carrying out the present invention will be described.

In this flexible circuit board 6, a silicon nitride layer 2a is formed on the surface of the resin film 1 by a sputtering method in which nitrogen is contained in an equivalent amount of 0.5 to 1.33 with respect to silicon, and a copper-based metal is further formed. Layer 3 is formed. In this example, the copper-based metal layer 3 is composed of a copper sputter film 4 formed by a sputtering method and a copper plating layer 5 formed by a plating method.

Examples of the above-mentioned resin film 1 include polyimide film, polyethylene terephthalate, polyethylene carbonate, and liquid crystal polymer film, which have heat resistance, mechanical stability, mechanical strength, electrical characteristics, etc. It is excellent in point and can be used suitably.

On the surface of the resin film 1, as an intermediate layer, a silicon nitride layer 2a containing 0.5 to 1.33 equivalent amounts of nitrogen relative to silicon is formed by reactive sputtering. . If the amount of nitrogen to silicon is less than 0.5 equivalently, the reliability at high temperature becomes a problem, and conversely, if it exceeds 1.33 equivalently, the adhesion becomes weak.

The thickness of the silicon nitride layer 2 a is preferably about 5 to 15 nm. If the thickness is less than 5 nm, moisture permeation from the resin film 1 side can not be sufficiently prevented under high temperature, and there is a problem with reliability. On the other hand, if it exceeds 15 nm, the film may be cracked or distorted. As the film peels off, the adhesion is rather weak. In particular, 8 to 12 nm is desirable, and the adhesion and reliability of the copper-based metal layer 3 are excellent.

In this example, the copper-based metal layer 3 is composed of a copper sputtered film 4 formed on the silicon nitride layer 2 a and a copper plated layer 5 formed on the copper sputtered film 4. There is. As the copper-based metal constituting the copper sputtered film 4 and the copper plating layer 5, that is, the copper-based metal layer 3, copper or a copper alloy can be used.

The sputtered copper film 4 is preferably formed to a thickness of about 50 to 100 nm. If the thickness is less than 50 nm, discoloration of the coating layer called "burn" tends to occur during copper plating in the next step, which makes it difficult to adjust the setting of copper plating conditions and, in some cases, adhesion To reduce the On the other hand, when lO O O n is exceeded, the sputtering time becomes long and the production rate is significantly reduced.

The thickness of the copper plating layer 5 can be appropriately determined by the electrical conductivity and the line width of the pattern, etc., but 0.2 μπ! It is set to about 15 μm. If it is less than 0.2 / m, it will be a problem in terms of electrical conductivity, and conversely it will exceed 15 im If this is the case, it may be difficult to form a fine pattern.

In this flexible circuit board 6, a silicon oxynitride silicon layer 2b is formed on the surface of the resin film 1 by a sputtering method in which nitrogen is contained in an equivalent amount of 0.3 to 1.1 with respect to silicon, and a copper-based metal is further formed. Layer 3 is formed. In this example, the copper-based metal layer 3 is composed of a copper sputter film 4 formed by a sputtering method and a copper plating layer 5 formed by a plating method.

On the surface of the resin film 1, as an intermediate layer, a silicon oxynitride layer 2b containing nitrogen in an equivalent of 0.3 to 1.1 by nitrogen equivalent to silicon is formed by reactive sputtering. . If the amount of nitrogen to silicon is less than 0.3 equivalent weight, the reliability at high temperature becomes a problem, and conversely, if the equivalent weight exceeds 1.1, the adhesion becomes weak.

The thickness of the silicon oxynitride layer 2 b is preferably about 5 to 20 nm. If the thickness is less than 5 nm, moisture permeation from the resin film 1 side can not be sufficiently prevented under high temperature, and there is a problem with reliability. On the other hand, if it exceeds 20 nm, the film may be cracked or distorted. As the film peels off, the adhesion is rather weak. In particular, 8 to 15 nm is desirable, and the adhesion and reliability of the copper-based metal layer 3 are excellent.

In this example, the copper-based metal layer 3 is formed of the copper sputtered film 4 formed on the silicon oxynitride layer 2 b and the copper plating layer 5 formed on the copper sputtered film 4. It is configured. As the copper-based metal constituting the copper sputtered film 4 and the copper plating layer 5, that is, the copper-based metal layer 3, copper or a copper alloy can be used.

Except for this point, it is the same as the flexible circuit board 6 of the first embodiment. The same symbols are attached to similar parts.

FIGS. 3 and 4 show an apparatus for manufacturing the flexible circuit board 6 described above. FIG. 3 shows a sputtering apparatus for forming the silicon nitride layer 2 a, the silicon oxynitride layer 2 b and the copper sputtered film 4, and FIG. 4 shows a plating apparatus for forming the copper plating layer 5.

The sputtering apparatus shown in FIG. 3 includes a plasma chamber 10 for performing plasma processing as a pretreatment, a first sputtering chamber 11 for performing a first sputtering process, and a first sputtering process for performing a first sputtering process. 2 Sputtering chamber 1 2 The plasma chamber 10, the first sputtering chamber 11 and the second sputtering chamber 12 are each connected to a vacuum pump (not shown) so that the pressure can be adjusted independently.

The plasma chamber 10 is supplied with the resin film 1 wound in a roll shape, the silicon nitride layer 2 and the copper in the first sputtering chamber 11 and the second sputtering chamber 12 respectively. A take-up roll 1 4 is provided for taking up the film 1 a with a seed layer on which the sputtered film 4 is formed. Further, the plasma chamber 10 is provided with a plasma processing apparatus 15 which performs plasma processing as a pretreatment to the resin film 1 supplied from the supply roll 13.

A gas obtained by adding 5 to 60% by volume of oxygen or nitrogen or a mixed gas thereof to argon gas is introduced into the plasma processing apparatus 15 as a gas for plasma processing. Then, a plasma is generated by applying a DC voltage, an AC voltage, or a high frequency voltage to the electrodes, and the resin film 1 is allowed to pass through the plasma atmosphere to carry out the plasma treatment. By this plasma treatment, functional groups are generated on the surface of the resin film 1, and the adhesion of the silicon nitride layer 2a and the silicon oxynitride layer 2b is enhanced. Even if argon gas alone is used as the plasma processing gas Good, but the effect is enhanced by mixing oxygen and nitrogen.

The resin film 1 plasma-treated in the plasma chamber 10 is supplied to the first sputtering chamber 11 to form a silicon nitride oxide film and a silicon oxynitride film by reactive sputtering. The first sputtering chamber 11 is provided with a silicon target 18 and a first roll 16 for feeding the resin film 1 plasma-treated in the area facing the silicon target 18. .

First, the method of the first embodiment for forming the silicon nitride layer 2a will be described. A negative voltage is applied to the silicon target 18 from the DC power supply 21. On the other hand, a high frequency bias voltage is applied to the first roll 16 by a high frequency power source 2. Then, a mixed gas of argon and nitrogen is introduced as a reactive sputtering gas. The ratio of argon gas to nitrogen gas is preferably in the range of 95: 5 to 50:50. If the amount of nitrogen gas is too low, the amount of nitrogen in the film becomes too low, and adhesion and reliability are obtained. I can not. On the other hand, if there is too much nitrogen gas, the deposition rate of the film will be slower, and more nitrogen than stoichiometry will be produced.

Further, the above-mentioned silicon nitride sputtering process is performed while applying a high frequency bias voltage to the first roll 16 which functions as a running roll called a can roll for cooling the film. This provides energy to promote the reaction and promotes the chemical reaction. The high frequency bias voltage is preferably in the range of 0.5 to 0.5 WZ cm ² . If it is less than 0.50 WZ cm ² , the adhesion can not be obtained, and if it exceeds 0.2 W / cm ² , the polyimide film is deteriorated and there is a problem with reliability. Without application of the high frequency Baiasu voltage, nitrogen components contained in the nitride silicon layer 2 a to be formed is significantly less, the adhesion strength and reliability such obtained Rere ₀ In this way, a silicon nitride sputtering process is performed on the surface of the resin film 1 to form a silicon nitride layer 2 a containing nitrogen in an equivalent amount of 0.5 to 1.33 with respect to silicon.

The resin film 1 on which the silicon nitride layer 2a is formed by the above-described silicon nitride sputtering process is supplied to the second sputtering chamber 12, and a copper sputtering process is performed.

The second sputtering chamber 12 is provided with a copper target 19 and a second roll 17 for feeding the resin film 1 in a region facing the copper target 19.

A negative potential voltage is applied to the copper target 19 by a DC power supply 21.

Then, copper sputtering is performed using argon gas as a sputtering gas to form a copper sputtered film 4.

The gas pressure of the plasma chamber 10, the first sputtering chamber 11 and the second sputtering chamber 12 may be substantially the same, but it is preferable to make the second sputtering chamber 12 the highest. If the gas pressure in the second sputtering chamber 12 becomes low, nitrogen gas flows from the first sputtering chamber 11 or the plasma chamber 10, and copper nitride is formed, and in some cases, the conductivity may be lost. is there.

The film 1 a with a seed layer on which the copper sputtered film 4 is formed is again sent to the plasma chamber 10 and is removed by the drying roll 14.

Next, the film 1a with a silicon layer on which the silicon nitride layer 2a and the copper sputtered film 4 are formed is subjected to a copper plating process with a continuous copper plating apparatus to form a copper plating layer 5.

The continuous copper plating device shown in Fig. 4 comprises a plating tank 2 5, a water washing tank 2 6 and a drying tank 2 7, and the film 1 a with a seed layer supplied by a supply roll 28 is copper in a copper sulfate bath or the like. The flexible circuit board of the present invention is formed by forming the plating layer 5 Take up the winding roll 2 9. In the figure, reference numeral 30 is a DC power supply, 31 is an anode, and 32 is a cathode roll.

In this example, the copper sputtering process and the copper plating process are the copper-based metal forming process of the present invention for forming the copper-based metal layer 3.

Next, the method of the second embodiment for forming the silicon oxynitride layer 2b will be described.

A negative voltage is applied to the silicon target 18 from the DC power supply 21. On the other hand, a high frequency bias voltage is applied to the first roll 16 by a high frequency power supply 20. Then, a mixed gas of argon, oxygen and nitrogen is introduced as a reactive sputtering gas. The ratio of argon gas to oxygen nitrogen mixed gas is preferably in the range of 90:10 to 60:40, and the ratio of oxygen gas to nitrogen gas in the oxygen nitrogen mixed gas is 10:90 to 2 0: 10 is a preferred range. If the amount of nitrogen gas is too low, the amount of nitrogen in the film will be too low to obtain adhesion and reliability. On the other hand, if there is too much nitrogen gas, the deposition rate of the film will be slower and more nitrogen than stoichiometry will be found.

In addition, the above silicon oxynitride sputter process is a first roll that functions as a traveling roll called a can roll for film cooling.

This is done while applying a high frequency bias voltage to 16. This provides energy to promote the reaction and promotes the chemical reaction. The high frequency bias voltage is preferably in the range of 0.5 to 0.5 cm ² . If it is less than 0.50 WZ cm ² , the adhesion can not be obtained, and if it exceeds 0.3 WZ cm ² , the polyimide film is deteriorated and there is a problem in reliability. Without the application of the high frequency bias voltage, the nitrogen component contained in the formed silicon oxynitride layer 2 b is considerably reduced, and adhesion and reliability can not be obtained. Thus, on the surface of the resin film 1, an oxynitride silicon sputtering process is performed to form an oxynitride silicon layer 2b containing nitrogen in an equivalent amount of 0.5 to 1.33 with respect to silicon.

The resin film 1 on which the silicon oxynitride layer 2 b is formed in the above-described silicon oxynitride sputtering process is supplied to the second sputtering chamber 12, and a copper sputtering process and a copper plating process are performed. The copper sputtering process and the copper plating process are the same as the method of the first embodiment described above.

As described above, in the first embodiment, the silicon nitride layer 2 a is formed on the surface of the resin film 1 by the sputtering method in which nitrogen is contained in an equivalent amount of 0.5 to 1.33 with respect to silicon. Further, a copper-based metal layer 3 was formed. Thus, the adhesion of the copper-based metal layer 3 is improved by forming the silicon nitride layer 2 a containing 0.5 to 1.33 nitrogen equivalently as the intermediate layer. . Furthermore, since the silicon nitride layer 2 a is an insulator, there is no need for etching, and only the copper-based metal layer 3 needs to be etched, so it is possible to perform fine etching without much side etching. Become. Moreover, even if moisture or oxygen permeates from the resin film 1 side under high temperature, it is blocked by the silicon nitride layer 2a, and oxidation of the copper-based metal layer 3 and deterioration of adhesion does not occur. It becomes flexible circuit board 6 with excellent reliability.

In addition, since the above-mentioned silicon nitride sputtering process is performed while applying a high frequency bias voltage to the first roll 16 which sends the resin film 1 in the region facing the silicon target 18, the resin is applied by the high frequency bias voltage. The first roll 16 on the side of the film 1 apparently shifts to the negative potential side with respect to the periphery, so that a sufficient amount of nitrogen in the silicon nitride can be secured. The adhesion of the silicon nitride layer 2 a is also significantly improves.

As described above, according to the second embodiment, the surface of the resin film 1 contains 0.5 to 1.33 equivalent amounts of nitrogen relative to silicon. A silicon oxynitride layer 2 b was formed, and a copper-based metal layer 3 was further formed. Thus, the adhesion of the copper-based metal layer 3 is considered to be good by forming the silicon oxynitride layer 2 b containing 0.5 to 1.33 equivalent amounts of nitrogen as the intermediate layer. Become. Furthermore, since the silicon oxynitride layer 2b is an insulator, there is no need for etching, and only the copper-based metal layer 3 needs to be etched, so that side etching does not occur so much and fine etching can be performed. Become. In addition, even if moisture or oxygen penetrates from the resin film 1 side at high temperature, it is blocked by the silicon oxynitride layer 2b, and oxidation of the copper-based metal layer 3 or deterioration of adhesion does not occur. Flexible circuit board 6 with excellent reliability.

In addition, since the above-mentioned silicon oxynitride process is performed while applying a high frequency bias voltage to the first port 16 for sending the resin film 1 in the region facing the silicon target 18, the resin by the high frequency bias voltage is used. Since the first roll 16 on the film 1 side apparently shifts to the negative potential side with respect to the surroundings, a sufficient amount of nitrogen in the silicon oxynitride can be secured and adhesion of the silicon oxynitride layer 2 b is also achieved. The power is also greatly improved.

FIG. 5 is a diagram for explaining a third embodiment of the present invention.

In this sputtering apparatus, a high frequency bias voltage is applied to the second port 17 of the second Spack chamber 12 by the high frequency power supply 22, and the copper sputtering process is performed in the area facing the copper target 19. While applying the high frequency bias voltage to the second roll 1 Ί which sends The power of the high frequency bias voltage is preferably in the range of 0.55 W / cm ² or more, and if it is less than this, a sufficient improvement in adhesion can not be obtained. The other parts are the same as in the first and second embodiments, and the same reference numerals are given to the same parts. By doing this, the adhesion of the copper sputtered film 4 is further improved. Otherwise, the same operation and effect as those of the first and second embodiments can be obtained. FIG. 6 is a diagram for explaining a fourth embodiment of the present invention.

In this sputtering apparatus, a common port 23 is provided between the first sputtering chamber 1 1 and the second sputtering chamber 12, and a high frequency bias voltage is supplied to the common port 23 by the high frequency power supply 22. It is applied. Then, the silicon nitride sputtering process, the silicon oxynitride sputtering process and the copper sputtering process are performed using the common roll 23 and are all performed while applying a high frequency bias voltage. The other parts are the same as in the first and second embodiments, and the same reference numerals are given to the same parts. By doing this, the adhesion of the copper sputtered film 4 is further improved. The other effects are the same as those of the first to third embodiments.

FIG. 7 is a diagram for explaining a fifth embodiment of the present invention.

This sputtering apparatus is provided with a deposition chamber 37 for performing vacuum deposition instead of the second sputtering chamber 12. In the deposition chamber 37, a copper supply portion 33 for supplying a copper wire 34 to be deposited, a pot 35 for melting the supplied copper wire 34, a heater 36 for heating the crucible 35 and In place of the copper sputtered film 4, a copper vapor-deposited film is formed. The other parts are the same as in the first to fourth embodiments, and the same reference numerals are given to the same parts. Also in this example, the same effects as those of the first to fourth embodiments can be obtained.

FIG. 8 is a diagram showing a sixth embodiment of the present invention.

As the copper-based metal layer 3, the flexible circuit board 6 is formed by forming a copper film 3 a by ion plating or vacuum evaporation and omitting copper plating. It is effective when the thickness of the copper film 3 a is 1 / m or less.

FIG. 9 is a cross-sectional view showing a flexible circuit board 6 according to a seventh embodiment of the present invention.

In this flexible circuit board 6, a silicon nitride layer 2 a or a silicon oxynitride layer 2 b is formed on the surface of the resin film 1 by sputtering. Further, a metal film 7 having a thickness of 0.5 to 5 nm selected from carbon, aluminum, and nickel is formed, and a copper-based metal layer 3 is further formed. In this example, the copper-based metal layer 3 is composed of a copper sputter film 4 formed by sputtering and a copper plating layer 5 formed by plating.

Examples of the above-mentioned resin film 1 include polyimide film, polyethylene terephthalate, polyethylene carbonate, and liquid crystal polymer film, in terms of heat resistance, mechanical stability, mechanical strength, electrical characteristics and the like. It is excellent and can be suitably used.

A silicon nitride layer 2a or a silicon oxynitride layer 2b is formed on the surface of the resin film 1 as a middle layer by reactive sputtering.

The silicon nitride layer 2 a is preferably a silicon nitride layer 2 a containing 0.5 to 1.33 of nitrogen equivalent to silicon. If the amount of nitrogen to silicon is less than 0.5 equivalently, the reliability at high temperature becomes a problem, and conversely, if it exceeds 1.33 equivalently, the adhesion becomes weak. The thickness of the silicon nitride layer 2 a is preferably about 5 to 15 nm. If the thickness is less than 5 nm, moisture permeation from the resin film 1 side can not be sufficiently prevented under high temperature, and there is a problem with reliability. On the contrary, if the thickness exceeds 15 nm, the film is cracked or distorted. Because of peeling, the adhesion is rather weak. In particular, 8 to 12 nm is desirable, and the adhesion and reliability of the copper-based metal layer 3 are excellent.

The silicon oxynitride layer 2 b is preferably a silicon oxynitride layer 2 b containing nitrogen in an equivalent amount of 0.3 to 1.1 with respect to the silicon. If the amount of nitrogen to silicon is less than 0.3 equivalently, the reliability at high temperature becomes a problem, and conversely, if it exceeds 1.1 equivalently, the adhesion becomes weak. The thickness of the silicon oxynitride layer 2 b is preferably about 5 to 20 nm. is there. If it is less than 5 nm, the permeation of water from the resin film 1 side can not be sufficiently prevented under high temperature, and there is a problem with reliability. On the other hand, if it exceeds 20 nm, the film may be cracked or distorted. As the film peels off, the adhesion is rather weak. In particular, 8 to 15 nm is desirable, and the adhesion and reliability of the copper-based metal layer 3 are excellent.

Next, a metal film 7 selected from kein, aluminum and nickel is formed. The thickness is preferably 0.5 to 5 nm, more preferably 1 to 3 nm. When the thickness of the metal film 7 is less than 0.5 nm or more than 5 nm, the effect of improving the adhesion of the copper-based metal layer 3 is small. The film forming method may be a vapor deposition method or the like, but the sputter method is preferable in view of the relationship between the degree of vacuum and the like and the adhesion.

In this example, the copper-based metal layer 3 is a copper sputtered film 4 formed on the silicon nitride layer 2 a or the silicon oxynitride layer 2 b, and a copper plating formed on the copper sputtered film 4. It consists of 5 layers. As the copper-based metal constituting the copper sputter film 4 and the copper plating layer 5, ie, the copper-based metal layer 3, copper or a copper alloy can be used.

The thickness of the copper plating layer 5 can be appropriately determined depending on the electrical conductivity, the line width of the pattern, and the like, but is set to about 0.2 m to 15 μm. If it is less than 0.2 im, it will be a problem in terms of electrical conductivity, and conversely, if it exceeds 15 μπι, it may be difficult to form a fine pattern. FIGS. 10 and 4 are diagrams showing an apparatus for manufacturing the flexible circuit board 6. 2 shows a sputtering apparatus for forming the silicon nitride layer 2 a, the silicon oxynitride layer 2 b, the metal film 7 and the copper sputtered film 4, and FIG. 3 shows a plating apparatus for forming the copper plated layer 5. Respectively.

The sputtering apparatus shown in FIG. 10 includes a plasma chamber 10 in which plasma processing is performed as a pretreatment, a first sputtering chamber 11 in which a first sputtering step is performed, and a second sputtering step in which a second sputtering step is performed. 2 Sputtering chamber 1 2 is provided. The plasma chamber 10, the first sputtering chamber 11 and the second sputtering chamber 12 are each connected to a vacuum pump (not shown) so that the pressure can be adjusted independently.

The plasma chamber 10 is supplied with the resin film 1 wound into a roll, and the silicon nitride layer 2 a or the silicon nitride layer 2 a in the first sputtering chamber 11 and the second sputtering chamber 12 respectively. A take-up roll 14 is provided for taking up a film 1 a with a seed layer on which the silicon oxynitride layer 2 b, the metal film 7 and the copper sputtered film 4 are formed. Further, the plasma chamber 10 is provided with a plasma processing apparatus 15 for performing plasma processing as a pretreatment on the resin film 1 supplied from the supply roll 13. A gas obtained by adding 5 to 60% by volume of oxygen or nitrogen or a mixed gas thereof to argon gas is introduced into the plasma processing apparatus 15 as a gas for plasma processing. Then, a plasma is generated by applying a DC voltage, an AC voltage, or a high frequency voltage to the electrodes, and the resin film 1 is allowed to pass through the plasma atmosphere to carry out the plasma treatment. By this plasma treatment, a functional group is generated on the surface of the resin film 1 and functions to enhance the adhesion of the silicon nitride layer 2 a and the silicon oxynitride layer 2 b. Although argon gas alone may be used as the plasma processing gas, the effect is enhanced by mixing oxygen and nitrogen. The resin film 1 subjected to plasma treatment in the plasma chamber 10 is supplied to the first sputtering chamber 11 to form a silicon nitride or silicon oxynitride film by reactive sputtering. The first sputtering chamber 11 is provided with a silicon target 18 and a first roll 16 for feeding the resin film 1 plasma-treated in the area facing the silicon target 18. .

First, the method of the first example for forming the silicon nitride layer 2 a will be described.

A voltage of negative potential is applied to the silicon target 18 by the DC power supply 21. On the other hand, a high frequency bias voltage is applied to the first roll 16 by a high frequency power supply 20. Then, a mixed gas of argon and nitrogen is introduced as a reactive sputtering gas. The ratio of argon gas to nitrogen gas is preferably in the range of 95: 5 to 50:50. If the amount of nitrogen gas is too low, the amount of nitrogen in the film becomes too low, and adhesion and reliability are obtained. I can not. On the other hand, if there is too much nitrogen gas, the deposition rate of the film will be slower, and more nitrogen than stoichiometry will be generated.

The silicon nitride sputtering process applies a high frequency bias voltage to the first roll 16 which functions as a roll for running, which is called a roller roll for film cooling. Do. This provides energy to promote the reaction and promotes the chemical reaction. The high frequency bias voltage is preferably in the range of 0.5 to 0.5 W / cm ² . If it is less than 0.50 WZ cm ² , adhesion can not be obtained, and if it exceeds 0.2 W / cm ² , the polyimide film will be deteriorated, resulting in problems in reliability. Without the application of the high frequency bias voltage, the nitrogen component contained in the formed silicon nitride layer 2 a is considerably reduced, and adhesion and reliability can not be obtained.

In this way, nitrogen is added to the surface of resin film 1 with respect to silicon. A silicon nitride sputtering process is performed to form a silicon nitride layer 2a containing an equivalent weight of 0.5-3.

The resin film 1 on which the silicon nitride layer 2a is formed in the above-described silicon nitride sputtering process is supplied to the second sputtering chamber 12 and has a thickness of 0.5 to 5 nm selected from silicon, aluminum and nickel. While the metal sputtering process for forming the metal film 7 is performed, the copper sputtering process is performed. In the second sputtering chamber 12, a metal target 24 and a copper target 19 consisting of metals selected from Ge, aluminum, and nickel, and the metal target 24 and the copper target 19 are faced. In the area, a second roll 1 7 for feeding the resin film 1 is provided.

A negative potential voltage is applied to the metal target 24 by a DC power supply 21 a. Then, using argon gas as a sputtering gas, metal sputtering is performed to form a metal film 7.

At this time, a high frequency bias voltage is applied by the high frequency power supply 22 to the second roll 1 which functions as a traveling roll called a roller for cooling the fnorem. It is preferred to do. This provides energy to promote the reaction and promotes the chemical reaction. The high frequency bias voltage is preferably in the range of 0.3 to 0.3 Wz cm ² . 0. Adhesion is somewhat weaker than 0 3 cm less than ^2, 0. When 2 exceeds WZ cm ^2, deteriorated Porii Mi de film, problems in reliability.

A negative potential voltage is applied to the copper target 19 by a DC power supply 21. Then, a copper sputtering process is performed using argon gas as a sputtering gas to form a copper sputtered film 4.

Also, the copper sputter process is carried out by the high frequency power supply 22 with respect to the second roll 17 which feeds the resin film 1 in the area facing the copper target 19. It can also be performed while applying a bias voltage. At this time, the power of the high frequency bias voltage is preferably 0.3 WZ cm ² or more, and if it is less than this, the effect of improving the adhesion can not be obtained. By doing so, the adhesion of the copper sputtered film 4 is further improved.

The gas pressure of the plasma chamber 10, the first sputtering chamber 11 and the second sputtering chamber 12 may be substantially the same, but it is preferable to make the second sputtering chamber 12 the highest. If the gas pressure in the second sputtering chamber 12 becomes low, nitrogen gas flows from the first sputtering chamber 11 or the plasma chamber 10, copper nitride is formed, and in some cases, the conductivity may be lost. It is.

The film 1 a with a seed layer on which the copper sputtered film 4 is formed is again sent to the plasma chamber 10 and wound off by the winding roll 14.

Next, the film 1a with a seed layer on which the silicon nitride layer 2a or the silicon oxynitride layer 2b, the metal film 7 and the copper sputtered film 4 are formed is subjected to a copper plating process using a continuous copper plating apparatus. The copper plating layer 5 is formed.

The continuous copper plating device shown in Fig. 4 comprises a plating tank 2 5, a water washing tank 2 6 and a drying tank 2 7, and the film 1 a with a shield layer supplied by the supply roll 28 is a copper sulfate bath or the like. A copper plating layer 5 is formed to form the flexible circuit board 6 of the present invention, and the winding roll 29 is scraped. In the figure, reference numeral 30 is a DC power supply, 31 is an anode, and 32 is a cathode roll.

Next, a method of the second example for forming the silicon oxynitride layer 2b will be described. A negative voltage is applied to the silicon target 18 from the DC power supply 21. On the other hand, a high frequency bias voltage is applied to the first roll 16 by a high frequency power supply 20. Then, a mixed gas of argon, oxygen and nitrogen is introduced as a reactive sputtering gas. With argon gas The ratio of the oxygen-nitrogen mixed gas is preferably in the range of 90:10 to 60:40, and the ratio of oxygen gas to nitrogen gas in the oxygen-nitrogen mixed gas is in the range of 10:90 to 40: 6. 0 is a preferred range. If the amount of nitrogen gas is too low, the amount of nitrogen in the film will be too low to obtain adhesion and reliability. On the other hand, if there is too much nitrogen gas, the film deposition rate will be slower and more nitrogen than stoichiometry will be found.

Further, the above-mentioned silicon oxynitride process is performed while applying a high frequency bias voltage to the first roll 16 which functions as a traveling roll called a can roll for cooling the film. This provides energy to promote the reaction and promotes the chemical reaction. The power of the above-mentioned high frequency bias voltage 0.5 to 0.5 Wz cm ² is a preferable range. 0. Not obtained adhesion force is less than 0 5 cm ^2, 0. 3 exceeds WZ cm ^2, it deteriorated Porii Mi de film, problems in reliability. Without the application of the high frequency bias voltage, the nitrogen component contained in the formed silicon oxynitride layer 2 b is considerably reduced, and adhesion and reliability can not be obtained.

Thus, on the surface of the resin film 1, a silicon oxynitride sputtering process is performed to form a silicon oxynitride layer 2b containing nitrogen in an equivalent amount of 0.5 to 1.33 with respect to silicon.

The resin film 1 on which the silicon oxynitride layer 2b is formed by the above-mentioned silicon oxynitride sputtering process is supplied to the second sputtering chamber 12, and a metal film sputtering process, a copper sputtering process and a copper plating process are performed. The metal film sputtering process, the copper sputtering process and the copper plating process are the same as the method of the first example described above.

As described above, in the present embodiment, the silicon nitride layer 2 a or the silicon oxynitride layer 2 b is formed on the surface of the resin film 1 by the spack method. Further, a metal film 7 having a thickness of 0.5 to 5 nm selected from carbon, aluminum and nickel was formed, and a copper-based metal layer 3 was further formed. Thus, as the intermediate layer, the silicon nitride layer 2a or the silicon oxynitride layer 2b and the metal film 7 with a thickness of 0.5 to 5 nm selected from carbon, aluminum, and nickel were formed. Thus, the adhesion of the copper-based metal layer 3 is improved. Furthermore, since the silicon nitride layer 2 a or the silicon oxynitride layer 2 b is an insulator, there is no need to etch, and only the extremely thin metal film 7 such as silicon and the copper-based metal layer 3 can be etched. Since it is sufficient, fine etching can be performed without much side etching. Moreover, even if moisture or oxygen permeates from the resin film 1 side at high temperature, it is blocked by the silicon nitride layer 2 a or the silicon oxynitride layer 2 b, and oxidation of the copper-based metal layer 3 or The flexible circuit board 6 has excellent adhesion and no reduction in adhesion.

In addition, the metal sputtering process as the second sputtering process of the present invention is carried out while applying a high frequency bias voltage to the second roll 17 sending the resin film 1 in the region facing the metal target 24. Since the second roll 17 on the resin film 1 side is apparently shifted to the negative potential side with respect to the surroundings due to the high frequency bias voltage, the adhesion of the metal film 7 is also greatly improved.

As the sputtering apparatus described above, a common roll is provided between the first sputtering chamber 1 1 and the second sputtering chamber 1 2, and a high frequency bias voltage may be applied to the common roll by a high frequency power supply. . The silicon nitride or silicon oxynitride sputter process, the metal sputter process and the copper sputter process may be performed using a common roll and may be performed while applying a high frequency bias voltage.

FIG. 11 shows a second embodiment of the present invention. As the copper-based metal layer 3, the flexible circuit board 6 is formed by forming a copper film 3 a by ion plating or vacuum evaporation and omitting copper plating. It is effective when the thickness of the copper film 3 a is 1 Z m or less. Examples will be described below.

Example 1

An electroconductive film was produced using the film forming apparatus shown in FIG. As the polyimide film, a 25 cm wide, 25 cm wide, Kanemitsu-made polyimide film N P I having a width of 25 cm was used. The film transport speed was 0.8 m / min. A mixed gas of 30% nitrogen and argon is added to the plasma processing chamber gas, the gas flow rate is adjusted so that the gas pressure in the plasma processing chamber becomes 0.5 Pa, and an AC voltage of 380 V is applied. The plasma was generated, and the film was passed into the plasma atmosphere.

In the next reactive sputtering chamber, the flow rate is adjusted to 0.4 Pa under a mixed gas condition of 70% argon and 30% nitrogen, and the DC voltage is 40 V, width 26 cm A high frequency of 13.56 MHz was applied to 160 W for the first ronore 16 with a diameter of 20 cm. The thickness of the formed film was 10 nm and the composition was S i N 1.2.

Next, a copper snotter was deposited under conditions of argon gas pressure: 0.6 Pa and DC voltage: 400 V using a second roll 17 having a width 26 cm and a diameter 40 cm. Next, using a copper plating apparatus shown in FIG. 4, a plating was carried out so that the thickness of copper became 10 μm, and a flexible circuit board 6 of the present invention was produced.

[Evaluation method]

Etching was performed so that the copper plating film remained in a width of 3 mm, and a tensile test was conducted in the vertical direction as defined in JIS C 5 0 16 to measure adhesion. Also, the reliability was measured at 180 ° C for samples etched to a width of 3 mm. It was left for 1 day, and the adhesion was similarly measured. Example 2

In Example 1, film formation was carried out under the same conditions except changing the film composition and film thickness by changing the nitrogen gas concentration such as silicon nitride sputter, DC voltage and high frequency power. Comparative example 1

As Comparative Example 1, a silicon nitride film having a composition of S i N O 3 was formed by changing the nitrogen gas concentration, DC voltage, and high frequency power in the silicon nitride film forming chamber.

The conditions for producing silicon nitride and the evaluation results in Example 1, Example 2 and Comparative Example 1 are shown in Table 1 below.

table 1

Example 3

Using the apparatus shown in FIG. 5, under the conditions of Example 1, film formation was performed under the same conditions except that high frequency power was applied to the copper sputtering nozzle.

The high frequency bias conditions at the time of copper sputtering in Example 3 and the evaluation results are shown in Table 2 below. Table 2

[Result of evaluation]

According to the standard, the initial value is 0.5 mm or more, and there is no stipulation after high temperature storage, but in general, it should be 0.4 mm or more. Also from the evaluation results, in each example, good results were obtained both in the initial adhesion and after storage at high temperature. On the other hand, in the case of the comparative example, both the initial adhesion and the high temperature storage showed low values. Example 4

An electroconductive film was produced using the film forming apparatus shown in FIG. For polyimido de norem, a 25 m-thick, 25 cm-wide, Kanei-forced polyimido film NPI was used. The film transport speed was 1 m / min. A mixed gas of 10% oxygen and 20% nitrogen is added to argon in the plasma processing chamber gas, the gas flow rate is adjusted so that the gas pressure in the plasma processing chamber becomes 0.5 Pa, and AC voltage A voltage of 380 V was applied to generate a plasma, and the film was passed through the plasma atmosphere.

In the next reactive sputtering chamber, the flow rate was adjusted to 0.4 Pa under the conditions of a mixed gas of 70% argon, 10% oxygen, and 20% nitrogen, and a DC voltage of 40 0 V, A high frequency of 1 3.56 MHz was applied to 2 4 5 W to a 1st ROM 1 16 having a width 26 cm and a diameter of 2 0 cm. The thickness of the formed film was 12 nm, and the composition was S i ON 0.7. Next, a copper snotter was deposited under conditions of argon gas pressure of 0.6 Pa and DC voltage of 400 V using a second roll 17 having a width of 26 cm and a diameter of 4 O cm. Next, the copper plating apparatus shown in FIG. 4 was used to make a copper thickness of 10 μm, and a flexible circuit board of the present invention was produced.

[Evaluation method]

Etching was performed so that the copper plating film remained in a 3 mm width, and a tensile test was conducted in the vertical direction as defined in J I S C 5 0 16 to measure adhesion. The reliability was also measured by keeping the sample etched to a width of 3 mm at 180 ° C. for 1 day, and measuring adhesion in the same manner. Example 5

The film formation was carried out under the same conditions as in Example 1 except that the nitrogen gas concentration, direct current voltage and high frequency power of silicon oxynitride sputter process were changed, and the film composition and the film thickness were changed. Comparative example 2

As Comparative Example 2, a silicon oxynitride film having a composition of Si N 0.3 was formed by changing the nitrogen gas concentration, DC voltage, and high frequency power in the silicon oxynitride film forming chamber. .

The conditions for producing silicon oxynitride and evaluation results in Example 4, Example 5 and Comparative Example are shown in Table 3 below. Table 3 Sample No Gas pressure Gas composition DC voltage RF power Film composition Film thickness Adhesion (N / mm)

(Pa) (Ar02: N2) (V) (W / cm2) (nm) Initial 180 ° C-1 day Example 4 0.5 7: 1: 2 440 0.15 SiONO.7 12 0.6 0.7

Example 5-1 0.5 7: 1: 2 425 0.15 SiON 0.7 6 0.8 0.7

Example 5-2 0.6 6: 1: 3 465 0.18 SiON 0.7 28 0.5 0.8

Example 5-3 0.5 7: 2: 1 450 0.1 SiO 1.5 N 0.3 15 0.5 0.6

Example 5-4 0.6 6: 0.5: 3.5 440 0.2 SiO 0.3 1.1 12 0.7 0.8

Comparative Example 2-1 0.5 7: 2: 1 450 0.03 SiO 1.8 N 0.1 15 0.1 0.3

Comparative Example 2-2 0.6 6: 0.3: 3.7 440 0.25 SiO 0.2 N 1.2 12 0.2 0.4

Example 6

Using the apparatus shown in FIG. 5, under the conditions of Example 4, the film was formed under the same conditions except that high frequency power was applied to the copper sputtering nozzle.

The high frequency bias conditions at the time of copper sputtering in Example 6 and the evaluation results are shown in Table 4 below. Table 4

[Result of evaluation]

According to the standard, the initial value is 0.5 NZ mm or more, and there is no stipulation after high temperature storage, but it is generally accepted that it should be 0.4 NZ m rn or more. Also from the evaluation results, in each example, good results were obtained both in the initial adhesion and after storage at high temperature. On the other hand, in the case of the comparative example, both the initial adhesion and the high temperature storage showed low values. Example Ί

The conductivity imparting film was formed using the film forming apparatus shown in FIG. As the polyimide film, a 25 μm thick, 25 cm wide, Kanemitsu-made polyimide film N P I was used. The film transport speed was 0.8 m / min. A mixed gas of 30% nitrogen to argon is added to the plasma processing chamber gas, the gas flow rate is adjusted so that the gas pressure in the plasma processing chamber becomes 0.5 Pa, and an AC voltage of 300 V is applied. The plasma was generated and the film was passed into the plasma atmosphere.

In the next reactive sputtering chamber, the flow rate is adjusted to 0.4 P a under a mixed gas condition of 70% argon and 30% nitrogen, and a DC voltage of 40 V, width 2 6 A high frequency of 13.56 MHz was applied to 160 W at 1 cm of the first ronore 16 with a diameter of 20 cm. The thickness of the film formed was 10 nm and the composition was S i N 1. 2.

Next, a silicon sputter for forming a silicon film as the metal film 7 used a second roll 17 having a width of 26 cm and a diameter of 40 cm. The silicon sputtering was formed under conditions of argon gas pressure of 0.6 Pa and DC voltage of 320 V. In addition, a copper snow bream. The film was formed under conditions of argon gas pressure of 0.6 Pa and DC voltage of 400 V using a width 26 cm and a diameter 4 O c m second roll 17. Next, using a copper plating apparatus shown in FIG. 3, a flexible circuit board 6 of the present invention was produced by plating so that the thickness of copper would be 10 m. Example 8

The film formation was performed under the same conditions as in Example 1 except that the film composition and the film thickness were changed by changing the nitrogen gas concentration, the direct current voltage and the high frequency power as silicon oxynitride sputtering process. Example 9

In Example 1, film formation was performed under the same conditions except that the metal film 7 was changed to a silica film to form an aluminum film and a nickel film, and the voltage was changed so as to obtain the same film thickness. did. -Example 1 0

The film formation was carried out under the same conditions as in Example 1 except that the thickness of the silicon film as the metal film 7 was changed. Example 1 1

A film was formed under the same conditions as in Example 1, except that a high frequency bias voltage was applied to the second port 17 during copper sputtering. Example 1 2

The conductivity imparting film was formed using the film forming apparatus shown in FIG. For polyvinyl dophinorem, a 25 μm thick, 25 cm wide, Kanemitsu-made polyimide film N P I having a thickness of 25 cm was used. The film transport speed was 1 m / min. A mixed gas of 10% oxygen and 20% nitrogen is added to argon in the plasma processing chamber gas, and the gas flow rate is adjusted so that the gas pressure in the plasma processing chamber becomes 0.5 Pa, and AC voltage 38 A voltage of 0 V was applied to generate a plasma, and the film was passed through the plasma atmosphere.

In the next reactive sputtering chamber, the flow rate is adjusted to 0.4 P a under the conditions of a mixed gas of 70% argon, 10% oxygen, and 20% nitrogen, and a DC voltage of 40 V, A high frequency of 1 3.56 MHz was applied to 2 45 W to a first roll 16 having a width 26 cm and a diameter of 20 cm. The thickness of the formed film was 12 nm, and the composition was S i ON 0.7. Next, a silicon sputter for forming a silicon film as the metal film 7 used a second roll 17 having a width of 26 cm and a diameter of 4 O cm. The silicon sputtering was carried out under the conditions of an atmospheric pressure of 0.6 Pa and a DC voltage of 320 V. In addition, copper sputtering was performed under the conditions of argon gas pressure 0.6 Pa and DC voltage 400 V. Next, using a copper plating apparatus shown in FIG. 3, the thickness was made to be 15 μm so that the flexible circuit board 6 of the present invention was produced. Example 1 3

The film formation was carried out under the same conditions as Example 12 except that the nitrogen gas concentration, DC voltage and high frequency power in the silicon oxynitride sputtering step were changed to change the film composition and film thickness. Example 1 4

An aluminum film and a nickel film were formed as the metal film 7 in Example 12 in the same manner as the metal film 7 except that the voltage was changed so as to obtain the same film thickness. Example 1 5

A film was formed under the same conditions as in Example 6, except that the film pressure of the silicon film as the metal film 7 was changed. Example 1 6

A film was formed under the same conditions as Example 12, except that a high frequency bias voltage was applied to the second roll 17 in the copper sputtering. Experimental example 1 In Example 7, film formation was performed under the same conditions except changing the film composition and film thickness by changing the nitrogen gas concentration, DC voltage, and high frequency power in the silicon nitride film forming chamber. Experimental example 2

A film was formed under the same conditions as Example 10 except that the thickness of the silicon film as the metal film 7 was changed.

[Evaluation method]

Etching was performed so that the copper plating film remained in a 3 m width, and a tensile test was conducted in the vertical direction as defined in J I S C 5 0 16 to measure adhesion. Also, the reliability was measured by similarly holding the sample etched to a width of 3 mm at 180 ° C. for 1 day. The conditions for producing silicon nitride and the evaluation results in Examples 7 to 10 are shown in Table 5 below.

Table 5

The high frequency bias conditions and evaluation results at the time of copper sputtering in Example 11 are shown in Table 6 below. Table 6

The conditions for producing silicon oxynitride and the evaluation results in Examples 1 to 15 are shown in Table 7 below.

Table 7

The high frequency bias conditions and evaluation results at the time of copper sputtering in Example 16 are shown in Table 8 below.

Table 8

The conditions for producing silicon nitride and the evaluation results in Experimental Examples 1 to 2 are shown in Table 9 below.

Table 9 Sample No. Gas pressure Gas composition DC voltage RF power Film composition Film thickness Metal film Adhesion (N / mm) (Pa) (ArN2) (V) (W / cm2) (nm) (nm) Initial 1 80 ° C- 1 Experimental Example 1-1 0.5 8: 2 385 0.098 SiN 1.2 3 Silicon 2 0.9 0.3 Experimental Example 1 1 2 0.5 7: 3 430 0.15 SiN 1.1 20 Silicon 2 0.3 0.6 Experimental Example 1 3 0.5 9: 1 400 0.01 SiN 0.3 10 Silicon 2 0.3 0.2 Experimental Example 1-4 0.6 5: 5 415 0.25 SiN 1.4 10 Silicon 2 0.9 0.3 Experimental Example 2-1 0.5 7: 3: 410 0.098 Si 1.2 10 Silicon 0.3 0.4 0.5 Experimental Example 2- 2 0.5 7: 3 410 0.098 SiN 1.2 10 silicon 6 0.4 0.7

[Result of evaluation]

According to the standard, the initial value is 0.5 Nz m or more, and there is no stipulation after high temperature storage, but in general, it should be 0.4 N Z m or more. From the evaluation results, good adhesion was obtained both in the initial stage and after storage at high temperature, and from the fact that it is an insulator, a flexible circuit board with a fine pattern without any etching problems was obtained.

Claims

The scope of the claims

1. On the surface of the resin film, a silicon nitride layer was formed by a sputtering method containing 0.5 to 1.33 equivalent amounts of nitrogen relative to silicon, and a copper-based metal layer was further formed. Flexible circuit board.

2. On the surface of the resin film, 0.3 to 1 in nitrogen equivalent to silicon.

1 A flexible circuit board characterized in that a silicon oxynitride layer is formed by a sputtering method and a copper-based metal layer is further formed.

3. A silicon nitride layer or a silicon oxynitride layer is formed by sputtering on the surface of the resin film, and a metal film with a thickness of 0.5 to 5 nm selected from Ge, Al and Ni is formed. Furthermore, a copper-based metal layer is formed.

4. A silicon nitride sputter process to form a silicon nitride layer containing 0.5 to 1.33 equivalents of nitrogen relative to silicon on the surface of the resin film, and a copper based metal to form a copper based metal layer. A method of manufacturing a flexible circuit board, comprising the steps of: forming a flexible circuit board;

5. The method for manufacturing a flexible circuit board according to claim 4, wherein the silicon nitride sputtering process is performed while applying a high frequency bias voltage to an electrode roll for sending a resin film in a region facing a target.

6. On the surface of the resin film, the nitrogen equivalent is 0.3 to 1 with respect to silicon.

1. A silicon oxynitride sputtering process for forming a silicon oxynitride layer contained And a copper based metal forming step of forming a copper based metal layer.

7. The method of manufacturing a flexible circuit board according to claim 6, wherein the silicon oxynitride process is performed while applying a high frequency bias voltage to an electrode roll for sending a resin film in a region facing the target.

8. A first sputtering process for forming a silicon nitride layer or a silicon oxynitride layer by a sputtering method on the surface of a resin film, and further, a thickness 0.5 to 5 selected from silicon, aluminum and nickel. A method of manufacturing a flexible circuit board, comprising: a second sputtering process for forming a metal film of 5 nm; and a copper-based metal forming process for forming a copper-based metal layer.

9. The method for manufacturing a flexible circuit board according to claim 8, wherein the second sputtering process is performed while applying a high frequency bias voltage to an electrode roll for sending a resin film in a region facing the target.