JPH0718421A - Substrate of high molecular material coated with electric conductive metallic film and its production - Google Patents

Abstract

PURPOSE:To produce a substrate of a high molecular material coated with an electric conductive metallic film and less liable to a change or deterioration in the adhesive strength of the metallic film to the substrate with the lapse of time even after film formation. CONSTITUTION:The objective substrate 1 of a high molecular material coated with an electric conductive metallic film 1c has a hydrogen ion (H<+>) implanted layer 1a in the surface part of the substrate 1 and an intermediate metallic film 1b on the outside of the layer 1a. The outside of the metallic film 1b is coated with the electric conductive metallic film 1c.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is for producing a film as a base for producing a so-called tab (TAB) package on which electronic parts such as an integrated circuit (IC) are mounted, and a flexible printed circuit (FPC). The present invention relates to a substrate, which is usually made of a polymer material such as a synthetic resin, such as a film to be the substrate, coated with a conductive metal film, and a method for producing the same.

[0002]

2. Description of the Related Art Integrated circuits (IC) and large scale integrated circuits (L)
Along with the practical application of (SI), a technique for wiring on a substrate made of various polymer materials has been established for mounting them. Although various methods have been tried as the wiring method, the following method is the most popular at present. That is, as the wiring substrate, for example, a polymer material film made of polyethylene terephthalate or a polyimide resin having excellent insulation and heat resistance is used, and a conductive metal film which is a wiring precursor, for example, copper (Cu), is formed on the substrate. A film or an aluminum (Al) film is formed by vacuum vapor deposition, sputtering, or the like. Further, for example, a desired wiring pattern is formed on the substrate covered with the film with a resist, and then unnecessary conductive metal film portions are removed by etching, and then the resist is removed with a solvent or the like.

[0003]

However, when the conductive metal film as the wiring precursor is formed on the polymer material substrate as described above, the adhesion between the substrate and the conductive metal film formed thereon is high. However, the film may peel off when the substrate is exposed to a high temperature or a low temperature after the film formation. There is also a problem that the film adhesion to the substrate decreases with time.

As a means for solving such a problem, nickel (Ni), titanium (Ti), and chromium are first formed on the substrate in order to improve the adhesion between the conductive metal film, which is a wiring precursor, and the substrate. It is also practiced to form an intermediate film made of a metal such as (Cr) and cover the outside with a conductive metal film. However, even a conductive metal film formed by such a method can be formed. Although the adhesive strength immediately after the film is strong, the adhesive strength significantly decreases with time.

Therefore, the present invention relates to a polymer material substrate coated with a conductive metal film, in which the adhesive force between the conductive metal film and the substrate is unlikely to change or decrease with time even after film formation. It is an object to provide a manufacturing method thereof.

[0006]

Means for Solving the Problems The present inventor has conducted extensive studies to solve the above problems and has obtained the following findings. That is, first,
The decrease in the adhesive force between the conductive metal film and the polymer material substrate is caused by oxygen (O) derived from water (H ₂ O) existing inside the substrate, the conductive metal film or the film and the substrate. It has been speculated that this is due to the oxidation and deterioration of the intermediate metal film formed at the interface with and for the purpose of strengthening the adhesion between the two. Therefore, when a hydrogen ion-implanted layer was formed on the surface of the substrate prior to the formation of the conductive metal film or the intermediate metal film, the adhesion of the conductive metal film or the intermediate metal film to the substrate was maintained for a long period of time. I found that.

Based on the above findings, the present invention is a polymeric material substrate coated with a conductive metal film, which has a layer in which hydrogen ions (H ⁺ ) are implanted in the surface portion of the substrate. A substrate characterized by being coated with a conductive metal film on the outside and a method for producing the same, wherein a polymer material substrate is irradiated with hydrogen ions (H ⁺ ) so that a hydrogen ion ( H ⁺ ) -implanted layer is formed, and then a conductive metal film is formed outside the ion-implanted layer.

The conductive metal film may be formed directly on the ion-implanted layer of the substrate, but may be formed on the ion-implanted layer by forming an intermediate metal film. The material of the polymeric material substrate in the present invention is not particularly limited, and for example, polyethylene terephthalate (P
ET), polyimide resin, etc. are considered.

In the substrate, the material of the conductive metal film is, for example, Cu, Al, silver (Ag), platinum (Pt), gold, which has high electric conductivity, excellent flexibility, and easy quality uniformity. (Au) and the like are possible. The material of the intermediate metal film formed at the interface between the substrate and the conductive metal film may be Ni, Ti, Cr or the like.

The method of the ion source used in the H ⁺ irradiation is not particularly limited, and for example, a non-mass separation type high frequency type,
Kauffman type, bucket type, etc. are conceivable. Further, hydrogen gas (H ₂ ) or the like can be considered as a source gas for generating H ⁺ . The irradiation energy and the irradiation amount in the H ⁺ irradiation differ depending on the materials of the substrate, the intermediate metal film and the conductive metal film, but the irradiation energy is 500e.
V to 10 KeV, irradiation dose is 1 × 10 ¹⁵ to 1 × 10 ²⁰
Ions / cm ² is preferable. When the irradiation energy is less than 500 eV, H ⁺ is not injected into the inside of the substrate, and when it is more than 10 KeV, the damage given to the substrate increases, and the adhesive force between the conductive metal film and the substrate decreases conversely. If the dose is less than 1 × 10 ¹⁵ ions / cm ² , the effect of H ⁺ implantation is insufficient, and if it is greater than 1 × 10 ²⁰ ions / cm ² , the damage to the substrate increases. However, the adhesive force between the conductive metal film and the substrate is decreased.

In the above H ⁺ irradiation, H that reaches the substrate
The number of ⁺ can be monitored by an ion current measuring device, for example, a Faraday cup equipped with a secondary electron suppressing electrode. The H ⁺ incident angle of the substrate is not particularly limited as long as the target ion-implanted layer can be obtained. As the method of forming the conductive metal film and the intermediate metal film, electron beam, resistance, laser,
Vacuum deposition for depositing a substance containing a target metal element by means such as high frequency, ion beam of the substance, magnetron, sputtering by means such as high frequency, plasma of an inert gas vapor deposition particles when depositing the substance, Ion plating or the like is conceivable in which ionization is performed by a means such as an electron beam, and irradiation of the ions is also used in the vapor deposition.
Further, a film may be formed on the substrate by an ion beam mixing technique in which vapor deposition or sputtering of the substance and irradiation of an ion species composed of an element different from the substance are used in combination.

The number of atoms of a substance vapor-deposited or sputtered in the above film formation can be monitored by a film thickness monitor, for example, a film thickness monitor using a crystal oscillator type film thickness meter, and ions arriving on the substrate in the ion beam mixing technique. The number of H
^{As in} the case of ⁺ irradiation, it can be monitored using an ion current measuring device. As the substance to be vapor-deposited, sputtered or ion-plated to form the intermediate metal film, a simple substance of Ni, a simple substance of Ti, a simple substance of Cr or the like can be considered.

Since the substrate of the present invention is used as an electrode on the outside by means such as wet plating, it is conceivable to increase the thickness of the conductive metal film to an arbitrary thickness.

[0014]

According to the method of the present invention, H is first applied to the polymer material substrate.
^By irradiating ^+, a layer in which H ⁺ has been injected is formed on the surface portion of the substrate, and a conductive metal film is formed directly or after an intermediate metal film is formed thereon. To be done. According to the substrate of the present invention thus formed, the adhesion between the conductive metal film and the polymer material substrate is good, and the good adhesion is maintained thereafter.

The reason why the film adhesiveness of the substrate of the present invention is less likely to change or decrease with time is because H injected into the surface portion of the substrate.
⁺ Traps oxygen (O) derived from water (H ₂ O) existing inside the substrate in the process of the oxygen flowing out to the outside of the substrate, so that the oxygen can be a conductive metal film or an intermediate metal. It is thought that this is because it is possible to prevent the film from penetrating into the film and thereby prevent the film from being deteriorated due to oxidation.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a sectional view of a substrate coated with a conductive metal film according to one embodiment of the present invention, and FIG. 2 shows a schematic structure of a film forming apparatus used in the method of manufacturing the substrate shown in FIG. .
The film forming apparatus in FIG. 2 includes film forming vacuum containers 2a, 2b, and 2c. The auxiliary vacuum chambers 3b and 3a are sequentially connected to one side of the container 2a, and the auxiliary vacuum chamber 3c is connected to one side of the container 2c.
3d are sequentially connected.

Partition walls between the auxiliary vacuum chambers 3a and 3d at the end and the outside, partition walls between the auxiliary vacuum chambers (3a and 3b) and (3c and 3d), the auxiliary vacuum chamber 3b, the vacuum container 2a and the auxiliary vacuum chamber. 3c and each of the partition walls of the vacuum container 2c, the vacuum containers (2a and 2
Each of the partition walls between b) and (2b and 2c) is provided with through holes 4a, 4h, 4b, 4g, 4c, 4f, 4d, and 4e which are as small as possible and through which the film-shaped substrate 1 can pass.

Vacuum containers 2a, 2b, 2c, auxiliary vacuum chamber 3
Vacuum pump connection 2 is provided on each of a, 3b, 3c and 3d.
a1, 2b1, 2c1, 3a1, 3b1, 3c1, 3d
1 is provided, and a vacuum pump (not shown) is connected to these, so that the inside of each container and each chamber can be evacuated and the inside of the vacuum containers 2a, 2b, 2c can be maintained at a predetermined film forming vacuum degree.

A substrate feeding reel 5 is arranged outside the auxiliary vacuum chamber 3a, and a substrate winding reel 5 is arranged outside the auxiliary vacuum chamber 3d. The reel 5 is rotatable, and the reel 6 is connected to a motor 62 via a joint device 61. By turning on the motor 62, the reel 6 can be rotationally driven clockwise in the drawing. At the center of the containers 2a, 2b, 2c, rotatable body guide drums 7a, 7b, 7 are provided.
c is installed, and it is possible to support and guide the film-shaped substrate 1 wound around the reel 5 from the reel 6 around the reel. Also, in the figure, 14a, 14b, 14c, 14
Reference numeral d denotes a substrate guide roller that supports and guides the substrate.

An ion source 8 is arranged below the drum 7a in the lower part of the container 2a, and in the lower part of the container 2b, 2c,
Directly below the drums 7b and 7c are sputter devices 9 and 1, respectively.
0 is arranged. The ion source 8 is, but not limited to, a bucket type here, and the sputtering apparatus 9, 10
Is a planar type high frequency magnetron sputtering apparatus.
In the sputtering devices 9 and 10, 9a and 10a are targets to be sputtered, 9b and 10b are permanent magnets, and 9
c and 10c are high frequency power supplies.

Further, the containers 2b and 2c are provided with sputtering gas supply units 11a and 11b. Further, in the container 2a, an ion current measuring device 12 for monitoring the amount of ion irradiation, here, a Faraday cup equipped with a secondary electron suppressing electrode is arranged, and in the containers 2b, 2c, the number of atoms of the vapor deposition substance reaching the substrate is reached. And film thickness monitor 1 for monitoring film thickness
3a, 13b, here a film thickness monitor using a crystal oscillator is arranged.

According to the film forming apparatus described above, the present invention
The law is implemented as follows. The film to be formed on the reel 5
The film-shaped polymer material substrate 1 is wound in advance and
Through holes 4a, 4b, 4c, 4d, 4
Connect to another reel 6 through e, 4f, 4g, and 4h.
Tie. In this state, the joint device 61 is engaged. This
And the auxiliary vacuum chambers 3a, 3b, 3c, 3d and
The inside of the vacuum containers 2a, 2b, 2c is replaced by a vacuum pump (not shown).
To evacuate the inside of the vacuum container 2a to about 1 x 10^-6~ 1 x 1
0^-FourAbout 1 × 10 in the Torr and vacuum containers 2b and 2c^-6~
1 x 10 ^-FourThe degree of vacuum is Torr.

In the container 2a, the hydrogen ion (H ⁺ ) 8a is irradiated from the ion source 8 to the substrate 1 along the drum 7a. The irradiation energy of H ⁺ is 500 eV to 10 KeV
It is desirable to set the dose to about 1 × 10 ¹⁵ to 1 × 1
It is desirable to set it to about 0 ²⁰ ions / cm ² . The amount of ion irradiation is monitored by an ion current measuring device 12, here, a Faraday cup equipped with a secondary electron suppressing electrode.

Next, in the container 2b, atoms, molecules, or ions containing the constituent elements of the intended intermediate metal film are vapor-deposited from the sputtering device 9 onto the substrate 1 into which hydrogen ions have been implanted, thereby forming an intermediate product. A metal film is formed. That is,
First, an inert gas, here an argon (Ar) gas, is used as a sputtering gas in the container 2b, and the amount of the inert gas is about 1 in the container 2b.
It is introduced until it reaches a value of × 10 ^-4 to 1 × 10 ^-2 Torr, and at the same time, high frequency power is applied from the high frequency power supply 9c. Plasma is generated by the action of this electric field and the magnetic field generated by the permanent magnet 9b, whereby the target 9a containing the constituent elements of the target intermediate metal film layer is sputtered, and the sputtered particles consisting of the constituent elements of 9a are attached to the drum 7b. Base 1
An intermediate metal film is formed by vapor deposition.

Further, in the container 2c, high frequency power is applied from the high frequency power source 10c of the sputtering device 10 in the same manner as the sputtering in the container 2b, so that the target 10a containing the constituent elements of the target conductive metal film is sputtered. Then, a conductive metal film is formed on the substrate 1 along the drum 7c. Other conditions are the same as in the case of forming the intermediate metal film.

The above-mentioned intermediate metal film and conductive metal film are the film thickness monitors 13a and 13b, here the film thickness monitor using a crystal oscillator, and the number of vapor-deposited atoms and film thickness reaching the substrate 1 are determined. A desired film thickness can be obtained by monitoring. As a result of the above-described film forming operation, as shown in FIG. 1, the surface portion of the substrate 1 has a layer 1a into which H ⁺ has been implanted, the outer side thereof has an intermediate metal film 1b, and the outer side thereof has a conductivity. The base 1 covered with the conductive metal film 1c is formed. In the substrate 1, due to the presence of the ion-implanted layer 1a, good adhesion between the substrate 1 and the inside of the intermediate metal film 1b formed for the purpose of improving the adhesion between the conductive metal film 1c and the substrate 1 is maintained for a long time. The conductive metal film 1c is held on the substrate 1 for a long period of time.

Next, a specific example of the method of manufacturing the substrate of the present invention by the film forming apparatus shown in FIG. 2 and the substrate coated with the conductive metal film obtained by the method will be described. Example As the substrate 1, a film-shaped substrate made of polyimide having a width of 200 mm and a thickness of 50 μm was used, and film formation was performed under the following conditions.

H ⁺ injection layer forming step: The inside of the vacuum container 2a is set to a vacuum degree of 7 × 10 ^-6 Torr. After that, hydrogen gas (H ₂ ) having a purity of 6N (99.9999%) is applied to the ion source 8.
Is introduced until the inside of the container 2a reaches 5 × 10 ⁻⁵ Torr,
Ionize the ions 8a to the substrate 1 at 2 KeV
With irradiation energy of 1 × 10 ¹⁶ ions / cm
Illuminated as ² .

Intermediate Metal Film Forming Step: The inside of the vacuum container 2b is set to a vacuum degree of 1 × 10 ⁻⁵ Torr. Then gas source 1
Ar gas was introduced from 1a until the inside of the container 2a reached 1 × 10 ⁻³ Torr, and at the same time, high frequency power having a frequency of 13.56 MHz was applied by the high frequency power source 9c, and the generated plasma generated a purity of 3N (99.9%). Nickel (N
i) The pellets were sputtered to form a Ni film 1b on the base 1 having the H ⁺ injection layer 1a. The thickness of the Ni film 1b was 0.05 μm.

Conductive metal film forming step: The inside of the vacuum container 2c was set to a vacuum degree of 1 × 10 ⁻⁵ Torr. After that, Ar gas from the gas source 11b is introduced into the container 2c at 1 × 10 ⁻³ Torr.
Until a high frequency power source 10c applies a high frequency power having a frequency of 13.56 MHz, and the generated plasma causes a purity of 4N (99.99%) copper (C
u) The pellet was sputtered to form a Cu film 1c on the substrate 1 having the Ni film 1b. The film thickness of the Cu film 1c was 0.3 μm.

The substrate 1 formed with the film in the above process is further
For testing, the Cu film was formed by the wet plating method.
The total thickness of the Cu film formed and the Cu film 1c is 30
μm. To test the adhesion of this Cu film,
As a comparative example, using the device of FIG. ⁺No irradiation, other
The conditions of are similar to those of the specific example of the above-mentioned embodiment, and the Ni film 1 and
A polyimide film having a Cu film (Comparative Example 1), and
And using the device of FIG.⁺Irradiation and Ni film formation
The other conditions are the same as in the specific example of the above-described embodiment, and the Cu film is formed.
Prepare a polyimide film (Comparative Example 2) that has only formed
did. Then, heat the three at a temperature of 150 ° C.
Of Cu film according to the method according to JISC-5016.
A peel strength test was performed. The test peel width is 2 mm
Then peeled off at an angle of 90 ° at a speed of 5 cm / min
It was

The results are shown in FIG. In the substrate having the H ⁺ injection layer according to the example, the Cu film peeling strength after film formation and before the heat treatment was strong, and the Cu film peeling strength was reduced by 20% after the heat treatment for about 40 hr, but after that, It can be seen that the strength is almost maintained. On the other hand, in the substrate having no H ⁺ injection layer according to Comparative Example 1, the Cu peeling strength after film formation and before the heat treatment is as strong as that of the substrate according to the embodiment, but after the heat treatment for about 50 hr, the Cu film peeling strength is high. It is about 80% lower.

Furthermore, the H ⁺ injection layer and Ni according to Comparative Example 2 were used.
The peel strength of the substrate having no film is not lowered even by the heat treatment, but the peel strength is as low as about 1/3 of that of the substrate according to the example from the beginning. Incidentally, without forming the intermediate Ni film, the C was directly formed on the substrate under the same conditions as in the above-mentioned embodiment.
When a u film was formed and the same strength test was performed, the decrease in the strength with time was small as in the above-mentioned Examples.

From the above results, it became clear that the adhesion between the Cu film and the substrate is maintained by forming the H ⁺ injection layer on the surface of the substrate.

[0035]

According to the present invention, a polymeric material substrate coated with a conductive metal film, in which the adhesion between the conductive metal film and the substrate is unlikely to change or decrease with time even after film formation. And a manufacturing method thereof.

[Brief description of drawings]

FIG. 1 is an enlarged cross-sectional view of a part of a substrate according to an embodiment of the present invention.

FIG. 2 is a diagram showing a schematic configuration of an example of a film forming apparatus used for manufacturing the substrate shown in FIG.

FIG. 3 is a diagram showing changes in Cu film peeling strength over time of the substrate shown in FIG.

[Explanation of symbols]

1 Substrate 1a Hydrogen Ion (H ⁺ ) Injection Layer 1b Intermediate Metal Film 1c Conductive Metal Film 2a, 2b, 2c Vacuum Container 2a1, 2b1, 2c1, 3a1, 3b1, 3c1, 3
d1 vacuum pump connection part 3a, 3b, 3c, 3d auxiliary vacuum chambers 4a, 4b, 4c, 4d, 4e, 4f, 4g, 4h through hole 5 substrate feeding reel 6 substrate winding reel 61 joint device 62 motors 7a, 7b, 7c Substrate guide drum 8 Ion source 9, 10 Sputtering device 9a, 10a Target 9b, 10b Permanent magnet 9c, 10c High frequency power supply 11a, 11b Sputtering gas supply unit 12 Ion current measuring instrument 13a, 13b Film thickness monitor 14a, 14b, 14c, 14d Substrate guide roller

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Osamu Imai 47 Umezu Takaunemachi, Ukyo-ku, Kyoto City Nissin Electric Co., Ltd. (72) Inventor Kiyoshi Ogata 47 Umezu Takaune-cho, Ukyo-ku, Kyoto City Nissin Electric Co., Ltd.

Claims (6)

[Claims] 1. A polymer material substrate coated with a conductive metal film, which has a layer into which hydrogen ions (H ⁺ ) are implanted at a surface portion of the substrate, the outside of which is coated with a conductive metal film. A polymeric material substrate coated with a conductive metal film. 2. An intermediate metal film is formed between the hydrogen ion-implanted layer of the substrate and the conductive metal film.
The substrate described. 3. The substrate according to claim 2, wherein the intermediate metal film is a film made of nickel, titanium or chromium. 4. A polymer material substrate is irradiated with hydrogen ions (H ⁺ ), whereby the hydrogen ion (H
⁺ ) Is formed, and then a conductive metal film is formed on the outside of the ion-implanted layer, and a method for producing a polymer material substrate covered with a conductive metal film. 5. The method according to claim 4, wherein an intermediate metal film is formed on the ion-implanted layer of the substrate and the conductive metal film is formed on the intermediate metal film prior to the formation of the conductive metal film. Substrate manufacturing method. 6. The method for manufacturing a substrate according to claim 5, wherein the intermediate metal film is formed of nickel, titanium or chromium.