JP2003007499A - Electrode for corona electric discharge, and surface treatment equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrode for corona electric discharge, in which a crevice cannot be generated easily between an electrode and dielectric components, and a part of the dielectric components cannot be dispersed easily at the time of a charge processing, and to provide surface treatment equipment using it. SOLUTION: This electrode 11 for corona electric discharge is used for the surface treatment equipment 1, which carries out the surface treatment of a processing object surface of a substrate 16 by corona electric discharge. It is constituted with a stick-like metal electrode 11a, a 1st dielectric component 11b which is formed of a hard-nature material and covers the metal electrode 11a along with the perimeter of the longer direction of the metal electrode 11a, and a 2nd dielectric component 11c, which is formed of a material, which has pliability, is filled up in the crevice between the metal electrode 11a and the 1st dielectric component 11b and is stuck to both of the metal electrode 11a and the 1st dielectric component 11b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a corona discharge electrode formed by coating a metal electrode with a dielectric member, and a substrate surface treatment apparatus using the corona discharge electrode.

[0002]

2. Description of the Related Art With the recent development of information communication technology, there is an increasing demand for a liquid crystal display used for a display section of a personal computer, a portable information terminal or the like, or a monitor screen section of a digital camera. A method of manufacturing a liquid crystal display includes an electrode process of forming an electrode pattern on a glass substrate, a panel assembly process of injecting liquid crystal by laminating two glass substrates at a predetermined interval, a assembled panel together with a driver IC and the like. And a mounting step of mounting.

In the electrode process, there is a process of cleaning the surface of the glass substrate before forming the undercoat film and before forming the electrode pattern. Further, in the panel assembling step, there is a step of cleaning the surface of the glass substrate after forming the overcoat film and before injecting the liquid crystal. In these cleaning steps, a wet cleaning method using a chemical or an organic solvent has been used.

However, such a wet cleaning method has technical problems such as a slight residue remaining after cleaning, a large scale of the cleaning processing apparatus, and the necessity of processing waste liquid after cleaning. It was Therefore, a treatment using plasma discharge, a treatment using corona discharge, or the like has come to be used.

Similarly, with the development of information and communication technology,
Multilayer printed circuit boards are rapidly spreading. Such a multilayer printed circuit board is composed of a laminated body in which an insulating layer made of a polymer or the like and a conductive layer made of a metal or the like formed in contact with the insulating layer are alternately stacked to be integrated. There is. In a multilayer printed circuit board,
In order to form a three-dimensional electric circuit, electrically conducting holes called via holes are provided in the insulating layer, and the electrically conductive layers are electrically connected. In the present application, a via hole refers to a blind via hole or the like that does not penetrate the substrate, and distinguishes a through hole that penetrates the substrate.

When forming a hole for a via hole in a multilayer printed circuit board, a residue called a smear containing a constituent material of an insulating layer remains on the bottom surface or inner wall surface of this hole, and a metal burr forming a conductive layer is generated. It may happen. Since the smear hinders the exposure of the conductive layer and causes poor conduction of the via hole, desmear treatment is performed to remove the smear with an oxidant solution such as potassium permanganate solution.

By the way, the required diameter of the via hole is, for example, φ50 as the multi-layer printed circuit board is mounted at a high density.
It has become as small as about μm, and smear cannot be sufficiently removed by the conventional wet processing. Therefore, instead of a wet desmear treatment using an oxidant solution, a dry desmear treatment that does not rely on a solution or the like is being used. As a dry desmear treatment, a treatment using plasma discharge, a treatment using corona discharge with a needle electrode or a linear electrode, and the like are known.

[0008]

In the conventional processing technique using corona discharge by needle-shaped electrodes, when the surface to be processed is widely and widely distributed, a large number of needle-shaped electrodes are provided or needles are formed. It was necessary to move the electrode in a rectangular shape, and it was difficult to uniformly process the surface to be processed.

On the other hand, in the conventional processing technique using the corona discharge by the linear electrode, although the difficulty of alignment in the needle electrode is reduced, the discharge is apt to become unstable and the current is concentrated in one place. Occurrence may occur and it may be transferred to arc discharge, which may damage the surface to be treated.

In order to cope with such a situation, the present inventors have found a means for preventing the discharge from becoming unstable by coating the surface of the rod-shaped electrode with a dielectric member. The present inventors further conducted technical studies and found a problem to be solved when coating a dielectric member on the electrode surface. One problem to be solved is that when a dielectric member composed of a hard material such as glass or ceramics is to be coated on the electrode surface, a gap is apt to occur between the electrode and the dielectric member, That is, it is difficult to obtain stable discharge. Another problem to be solved is that when a flexible material such as silicone rubber or fluororubber is used to cover the electrode surface to form a dielectric member on the electrode surface, a gap between the electrode and the dielectric member is required. Although there is no gap in the surface, a part of the dielectric member scatters (sputters) during the discharge process, and fine particles are generated to stain the surface to be processed.

Therefore, the present invention provides a corona discharge electrode and a surface treatment apparatus using the same, in which a gap is unlikely to be formed between the electrode and the dielectric member and a part of the dielectric member is less likely to scatter during discharge processing. This is an issue.

[0012]

The electrode for corona discharge of the present invention is used in a surface treatment apparatus for treating the surface to be treated of a substrate by corona discharge, and comprises a rod-shaped metal electrode and a hard material. And a first dielectric member that covers the metal electrode along the outer circumference in the longitudinal direction of the metal electrode, and is formed using a material having flexibility. The metal electrode and the first dielectric member A second dielectric member, which is filled in a gap between the member and is in close contact with both the metal electrode and the first dielectric member, is configured.

According to the present invention, since the rod-shaped metal electrode is covered with the first dielectric member made of a hard material, current concentration does not occur at a specific place during corona discharge. The surface to be treated is not contaminated by the scattering of the dielectric member. Moreover, since the gap between the metal electrode and the first dielectric member is filled with the second dielectric member, the gap between the metal electrode and the first dielectric member and the second dielectric member is reduced. Corona discharge is more stable without voids.

In the corona discharge electrode of the present invention, the hard material forming the first dielectric member is selected from the group consisting of glass, alumina, polycrystalline sapphire, single crystal sapphire, zirconia and steatite. You may do it. By doing so, current concentration does not occur at a specific location during corona discharge, and the surface to be treated is not contaminated by the scattering of the dielectric member.

In the corona discharge electrode of the present invention, the flexible material used for forming the second dielectric member is made of one-component silicone rubber, two-component silicone rubber or two-component silicone rubber. It may be selected from the group consisting of fluororubber. With this configuration, the gap between the metal electrode and the first dielectric member can be filled and cured, and the space between the metal electrode and the first dielectric member and the second dielectric member can be increased. Since there are no voids in the corona, the corona discharge becomes more stable.

The surface treatment apparatus of the present invention is for subjecting the surface to be treated of the substrate to a surface treatment by corona discharge, and is composed of a rod-shaped metal electrode and a hard material.
A first dielectric member that covers the metal electrode along the outer circumference in the longitudinal direction of the metal electrode, and a gap formed between the metal electrode and the first dielectric member that is formed using a flexible material. The corona discharge electrode, which is filled with the metal and has a second dielectric member in close contact with both the metal electrode and the first dielectric member, is arranged at a position facing the surface to be treated. Has been done.

According to the present invention, since the rod-shaped metal electrode is covered with the first dielectric member made of a hard material, current concentration does not occur at a specific place during corona discharge. The surface of the substrate to be processed is not contaminated by the scattering of the dielectric member. Moreover, since the gap between the metal electrode and the first dielectric member is filled with the second dielectric member, the gap between the metal electrode and the first dielectric member and the second dielectric member is reduced. Corona discharge is more stable without voids in the first dielectric member, and heat generation in the first dielectric member and the second dielectric member can be suppressed.

In the surface treatment apparatus of the present invention, the hard material forming the first dielectric member is selected from the group consisting of glass, alumina, polycrystalline sapphire, single crystal sapphire, zirconia and steatite. You may
With this configuration, current concentration does not occur at a specific location during corona discharge, and the surface of the substrate to be processed is not contaminated due to scattering of the dielectric member.

Further, the surface treatment apparatus of the present invention comprises a flexible material used for forming the second dielectric member,
It may be selected from the group consisting of one-component silicone rubber, two-component silicone rubber, and two-component fluororubber. With this configuration, the gap between the metal electrode and the first dielectric member can be filled and cured, and the space between the metal electrode and the first dielectric member and the second dielectric member can be increased. Since there are no voids in the corona, the corona discharge becomes more stable.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described with reference to the drawings. When possible, the same parts are designated by the same reference numerals, and overlapping description will be omitted.

A surface treatment apparatus 1 which is an embodiment of the present invention will be described with reference to FIG. FIG. 1 is a diagram showing the configuration of the surface treatment apparatus 1. The surface treatment apparatus 1 includes a base 1
3, a transport roller 12, a corona discharge electrode 11, a transport stand 14, and a high-frequency high-voltage power supply 15. Subsequently, each component will be described.

The transport roller 12 is attached to the base 13 by a locking means (not shown), and is constructed as an assembly of a plurality of roller-shaped members capable of rotating at an arbitrary speed and timing. By rotating the transport roller 12, the transport target placed on the transport roller 12 can be moved in the direction of arrow A at a predetermined speed and timing.

The carrier 14 is mounted on the carrier roller 12, and the substrate 16 is mounted thereon. The carrier 14 is formed of a metal plate larger than the substrate 16 and is connected to the high-frequency high-voltage power supply 15 via the external circuit 15b, and may be grounded or not grounded.

The high-frequency high-voltage power supply 15 is connected to the corona discharge electrode 11 via the high-voltage side external circuit 15a and to the carrier table 14 via the low-voltage side external circuit 15b. 5 kV to 14 at a high frequency of 5 kHz to 500 kHz for the electrode 11 and the carrier 14.
It is possible to apply an alternating voltage of kV. 5
If it is less than kV, corona discharge may not occur or may become non-uniform, and if it is 14 kV or more, there is a risk of causing damage to the surface to be processed of the substrate 16.

The corona discharge electrode 11 will be described with reference to FIG. FIG. 2 is a view showing a II cross section of FIG. 1. The corona discharge electrode 11 is attached to an electrode supporting beam (not shown), and both ends of the electrode supporting beam are fixed by supporting members (not shown). The support member is configured to be movable up and down while supporting the electrode support beam.
An example of such a supporting member is a structure having a base portion, a screw portion, an adjusting knob, a supporting portion, and a position needle. More specifically, the base portion is fixed to the base 13, and a female screw is formed on the side opposite to the side fixed to the base 13, and the male screw of the screw portion is screwed. Has been done. An adjusting knob is attached to an end portion of the screw portion opposite to the side where the male screw is formed, and the screw portion can be moved up and down with respect to the base portion by turning the adjusting knob. The support portion fixes the corona discharge electrode and the screw portion, and the screw portion is rotatably attached to the support portion. The position hand is attached to the support part and indicates the scale formed on the base part, and the discharge distance a between the corona discharge electrode 11 and the substrate 16 can be adjusted.

The discharge distance a between the corona discharge electrode 11 and the substrate 16 is preferably 0.5 mm or more and 5 mm or less,
If it is less than 0.5 mm, it is difficult to maintain the distance between the corona discharge electrode 11 and the substrate 16, and if it is 5 mm or more, the voltage applied to the corona discharge becomes too high, and the transformer becomes large and the power consumption becomes large. Further, the variation of the discharge distance a is adjusted to be ⅕ or less of the discharge distance a.

The corona discharge electrode 11 includes a pipe-shaped metal electrode 11a and a pipe-shaped first dielectric member 11 as well.
b, and the second dielectric member 11c filled in the gap between the metal electrode 11a and the first dielectric member 11b. The length of the metal electrode 11a is at least longer than one side of the substrate 16, and stainless steel is used as the material. The first dielectric member 11b is longer than the metal electrode 11a, and its inner diameter d2 is larger than the outer diameter of the metal electrode 11a. Quartz glass is used as the material forming the first dielectric member 11b, but it is preferable that the first dielectric member 11b is made of a hard material that does not scatter during corona discharge. Materials such as alumina, polycrystalline sapphire, single crystal sapphire, zirconia, and steatite are used.

As the second dielectric member 11c, one-component silicone rubber is used after being thermally cured. As the one-pack type silicone rubber, condensation type, alcohol type, oxime type, and acetone type which have good adhesiveness and little corrosive property are preferably used. The material used for the second dielectric member 11c does not change its characteristics depending on the temperature after curing, and is highly flexible because it absorbs and absorbs external stress.
The one with high adhesion is used. As such a material, in addition to the one-pack type silicone rubber, a two-pack type silicone rubber or fluororubber is also used. As the fluororubber, types such as UDF-HFP series, TFE-P series, fluorosilicone series, fluorovinyl ether series, and fluorophosphazene series are used.

Next, a method of manufacturing the corona discharge electrode 11 will be described with reference to FIG. FIG. 3 is a diagram showing a method of manufacturing the corona discharge electrode 11. First, the metal electrode 1
1a, the 1st dielectric member 11b, and the guide member 31 are prepared (FIG.3 (a)). The guide member 31 includes a rod-shaped portion 31b inserted into the hollow portion of the metal electrode 11a and a taper portion 31a attached to one end of the rod-shaped portion 31b.
It consists of and. The tapered portion 31a has a truncated cone shape, a portion attached to one end of the rod-shaped portion 31b has a circular shape having a diameter substantially the same as the outer diameter d1 of the metal electrode 11a, and a portion on the opposite side has a diameter of the metal electrode. Outer diameter d1 of 11a
It has a smaller circular shape. The guide member 31 is inserted in the hollow portion of the metal electrode 11a along the direction of arrow B.

Next, a second dielectric member 11c (one-component silicone rubber) is provided on the inner circumference of the first dielectric member 11b.
The coating is applied so that the coating thickness is larger than the difference between the outer diameter d1 of the metal electrode 11a and the inner diameter d2 of the first dielectric member 11b (FIG. 3B). Then, the metal electrode 11a is inserted into the first dielectric member 11b in the direction of arrow D from the side where the guide member 31 is attached. At that time, if it is rotated in the direction of arrow C, it can be smoothly inserted (FIG. 3).
(B)). Slowly insert the metal electrode 11a to a position where it is completely inserted into the first dielectric member 11b (FIG. 3).
(C)). After that, the guide member 31 is removed in the direction of arrow E (FIG. 3D), and the metal electrode 11a and the first dielectric member 11b are heated slowly at the same time in the direction of arrow F while being heated at 60 to 80 ° C. The second dielectric member 11c is accelerated and hardened to complete the corona discharge electrode 11 (FIG. 3D).

FIG. 3 (e) is a view showing a II-II cross section of FIG. 3 (d). As shown in FIG. 3E, the second dielectric member 11c includes the metal electrode 11a and the first dielectric member 1
It is in close contact with both 1b. In addition, as in the portion H of FIG. 3E, the metal electrode 11a is connected to the first dielectric member 11b.
Even if the second dielectric member 11c is scraped off when it is inserted into, it is sufficient if it is in close contact with the portion in contact with the metal electrode 11a. Similarly, when removing the guide member 31, as shown in FIG.
Even if the second dielectric member 11c is scraped off like the G portion of (e), it is sufficient if the second dielectric member 11c is in close contact with the portion in contact with the metal electrode 11a.

FIG. 4 is a view showing a section taken along line III-III in FIG. 3 (d). Metal electrode 11a and first dielectric member 11
The positional relationship with b is preferably concentrically arranged as shown in FIG. 4 (a), but as shown in FIG. 4 (b), the arrangement position of the metal electrode 11a is eccentric, and It may be configured so as to partially contact the dielectric member 11b.

A method of treating the surface of the substrate 16 using the surface treatment apparatus 1 according to the embodiment of the present invention will be described with reference to FIGS. A glass plate of 330 mm × 300 mm is used as the substrate 16. The metal electrode 11a has a length of 36
A stainless pipe having a diameter of 0 mm, an outer diameter d1 of 15 mm, and a wall thickness of 2 mm is used. In addition, the first dielectric member 11
b has a length of 400 mm, an inner diameter d2 of 16 mm,
A quartz glass tube with a wall thickness of 1 mm is used.

First, the surface of the substrate 16 is polished to eliminate irregularities and undulations on the surface, and then the substrate 16 is placed on the carrier 14 with the surface to be processed facing up. In the direction of 5 mm / sec. The discharge distance a between the corona discharge electrode 11 and the substrate 16 is 1
mm. Further, the variation of the discharge distance a is adjusted to be ⅕ or less of the discharge distance a.

When the substrate 16 passes directly under the corona discharge electrode 11, a high frequency high voltage power supply 15 applies an alternating voltage of 10 kV and 20 kHz to the corona discharge electrode 11 and the carrier 14. As described above, when the voltage is applied to the corona discharge electrode 11 and the carrier 14, the electric field increases, and when the electric field reaches a certain critical value, corona discharge occurs. At this time, the corona discharge generated from the corona discharge electrode 11 removes foreign matters on the surface to be processed of the substrate 16 and makes the surface hydrophilic. Such corona discharge treatment,
The substrate 16 is moved to the corona discharge electrode 11 by the transport roller 12.
It is possible to process the entire substrate 16 by moving it while moving it in a direction orthogonal to the longitudinal direction. As a result of the experiments conducted by the present inventors under these conditions, the corona discharge treatment had a sufficient effect, and the scattering of the first dielectric member 11b was very small even after long-term use.

In order to confirm the effect under other conditions, the present inventors have determined that the metal electrode 11a has a length of 360 m.
m, an outer diameter d1 is 6 mm, a solid stainless steel rod is used, and the first dielectric member 11b is made of alumina having a length of 400 mm, an inner diameter d2 of 7.5 mm, and a wall thickness of 1 mm. A corona discharge electrode 11 was formed using one-component silicone rubber as the body member, and corona discharge treatment was performed. The transport speed was 5 mm / sec, and an alternating voltage having a voltage of 11 kV and a frequency of 20 kHz was applied to the corona discharge electrode 11. Even under this condition, the corona discharge treatment has a sufficient effect, and the first dielectric member 11 can be used even for a long time.
The scattering of b was very slight.

When a glass substrate used for a liquid crystal display is subjected to surface treatment by the surface treatment apparatus 1 according to the present embodiment, it is performed in the electrode process before the undercoat film is formed or the electrode pattern is formed. The surface treatment is performed in the step of cleaning the surface of the glass substrate before or in the step of cleaning the surface of the glass substrate after forming the overcoat film and injecting the liquid crystal in the panel assembling step.

Further, the substrate is not limited to the glass substrate, and the printed board can be surface-treated. In this case, the printed board is sucked onto the carrier 14 to remove the distortion of the printed board, and then the surface treatment is performed. Numerical conditions at that time are as follows: the carrier speed of the carrier 14 is 5 mm / sec, the discharge distance a between the corona discharge electrode 11 and the printed circuit board is 1.5 mm, and the corona discharge electrode 11 and the carrier 14 are applied. AC voltage is
It is preferable that the voltage is 9.2 kV and the frequency is 10 kHz. When the printed board is surface-treated, a via hole is formed in the printed board, the surface treatment is performed by the surface treatment apparatus 1 according to the present embodiment to remove smear, and then plating is performed. A conductive plating layer is formed in the process.

The operation and effect of the embodiment of the present invention will be described. Since the pipe-shaped or solid rod-shaped metal electrode 11a made of stainless steel is covered with the first dielectric member 11b made of quartz glass or alumina which is a hard material, a current is applied to a specific portion during corona discharge. Concentration does not occur, and the substrate 16 is formed by scattering the dielectric member.
The surface to be processed does not get dirty. In addition, the metal electrode 11
Since the gap between a and the first dielectric member 11b is filled with the second dielectric member 11c made of one-component silicone rubber, the metal electrode 11a and the first dielectric member 11 are filled.
Since there is no gap between b and the second dielectric member 11c, the corona discharge becomes more stable.

[0040]

According to the present invention, since the rod-shaped metal electrode is covered with the first dielectric member made of a hard material, current concentration occurs at a specific location during corona discharge. Therefore, the surface to be treated is not contaminated by the scattering of the dielectric member. Moreover, since the gap between the metal electrode and the first dielectric member is filled with the second dielectric member, the gap between the metal electrode and the first dielectric member and the second dielectric member is reduced. Corona discharge becomes more stable because voids are not generated in. Therefore, the object of the present invention is to provide a corona discharge electrode in which a gap is less likely to be formed between the electrode and the dielectric member, and a portion of the dielectric member is less likely to scatter during discharge processing, and a surface treatment apparatus using the same. I was able to.

[Brief description of drawings]

FIG. 1 is a diagram showing a surface treatment apparatus 1 according to an embodiment of the present invention.

FIG. 2 is a view showing a II cross section of FIG.

3 is a diagram showing a method of manufacturing a corona discharge electrode 11 used in the surface treatment apparatus 1 of FIG.

FIG. 4 is a view showing a cross section taken along the line III-III of FIG.

[Explanation of symbols]

1 ... Surface treatment device, 11 ... Corona discharge electrode, 11a ...
Metal electrode, 11b ... 1st dielectric member, 11c ... 2nd dielectric member, 12 ... conveyance roller, 13 ... base, 14 ... conveyance stand, 15 ... high frequency high voltage power supply, 16 ... substrate.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H05K 3/42 610 H05K 3/42 610A // H05K 3/46 3/46 NY (72) Inventor Kobe Kazuno 1126, Nomachi, Hamamatsu, Shizuoka Prefecture 1126, Hamamatsu Photonics Co., Ltd. (72) Inventor, Tomonori Ota 1126, Nomachi, Hamamatsu City, Shizuoka Prefecture 1126, Hamamatsu Photonics Co., Ltd. F-term (reference) 2H088 FA17 FA30 HA01 HA02 MA20 2H090 HC18 JB02 JC19 4G075 AA30 BC10 CA18 CA25 DA02 EB24 EC06 EC21 ED09 ED11 FA12 FB02 FB04 FB06 FB12 FB13 FC11 FC15 5E317 AA24 BB01 BB11 CD01 CD27 GG16 5E346 AA43 FF03 GG16 H16

Claims (6)

[Claims] 1. A corona discharge electrode used in a surface treatment apparatus for treating a surface to be treated of a substrate by corona discharge, comprising a rod-shaped metal electrode and a hard material. A first dielectric member covering the metal electrode along the outer periphery in the longitudinal direction, and a gap formed between the metal electrode and the first dielectric member, the gap being formed using a material having flexibility. And a second dielectric member that is filled in the second dielectric member that is in close contact with both the metal electrode and the first dielectric member. 2. The hard material forming the first dielectric member is selected from the group consisting of glass, alumina, polycrystalline sapphire, single crystal sapphire, zirconia, and steatite. 1. The electrode for corona discharge according to 1. 3. The flexible material used to form the second dielectric member is selected from the group consisting of one-component silicone rubber, two-component silicone rubber, and two-component fluororubber. The electrode for corona discharge according to claim 1, wherein 4. A surface treatment apparatus for treating the surface to be treated of a substrate by corona discharge, comprising a rod-shaped metal electrode and a hard material, and extending along the outer periphery in the longitudinal direction of the metal electrode. A first dielectric member that covers the metal electrode, and a flexible material that is formed in a gap between the metal electrode and the first dielectric member. A surface on which a corona discharge electrode including a second dielectric member that is in close contact with both the metal electrode and the first dielectric member is disposed at a position facing the surface to be treated. Processing equipment. 5. The hard material composing the first dielectric member is selected from the group consisting of glass, alumina, polycrystalline sapphire, single crystal sapphire, zirconia, and steatite. 4. The surface treatment device according to 4. 6. The flexible material used to form the second dielectric member is selected from the group consisting of one-component silicone rubber, two-component silicone rubber, and two-component fluororubber. The surface treatment apparatus according to claim 4, wherein