JPH09139565A - Electrode pattern formation method - Google Patents

Abstract

(57) Abstract: To provide a simple electrode pattern forming method that does not need to provide an adhesive or adhesive insulating resin layer unlike a plating pattern transfer method. SOLUTION: A transfer substrate 3 is formed by forming an insulating layer 2 having a pattern opposite to an electrode to be formed on a conductive plate material 1.
Then, the electrode material 4 is plated on the conductive parts of the transfer substrate 3 other than the insulating layer 3, and only the pattern of the electrode material 4 is bonded to the glass substrate 5 by the anodic bonding method.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a printed wiring board,
The present invention relates to a method for forming an electrode pattern on a plasma display panel substrate or the like.

[0002]

Usually, in the electrode pattern as described above, a thin film of an electrode material is formed on the entire surface of a substrate on which an electrode is to be formed by a sputtering method or the like, and the thin film is formed by a photolithography method (resist film formation). , Exposure, development, etching, and resist stripping), but this method has the drawback of requiring long steps. Therefore, in order to simplify this photolithography method as much as possible, a method of using an electrode material having photosensitivity is also used, but in any case, a thin film must be formed on the entire surface of the substrate. It has the drawback of requiring a large amount of material.

On the other hand, there is known a method of forming an electrode pattern on a substrate by using a transfer plate formed by forming a pattern of an insulating material on a conductive material. That is, a metal pattern is selectively formed in advance only on a conductive portion (that is, a portion corresponding to an electrode pattern after transfer) of the transfer plate by a plating method, and an adhesive or tacky material is formed only on the plated pattern. This is a method in which an electrodeposition type insulating resin layer is formed by an electrodeposition method, and then the plate is pressure-bonded and peeled off from the substrate to transfer only the two-layer structure pattern portion of the insulating resin layer and plating. However, although this plating pattern transfer method has an advantage that the electrode pattern can be formed by a simple method similar to the printing method, it requires a step of forming an adhesive or adhesive insulating resin layer. In the case of a plasma display panel, there is a problem that the insulating resin layer burns during firing, and the electrode pattern is peeled off from the glass substrate.

The present invention has been made in view of the above circumstances, and an object thereof is a simple method in which it is not necessary to provide an insulating resin layer having an adhesive property or an adhesive property unlike the plating pattern transfer method. Another object is to provide a simple electrode pattern forming method.

[0005]

To achieve the above object, the electrode pattern forming method of the present invention is characterized by comprising at least the following steps. (1) A step of forming a transfer substrate by forming an insulating layer having a pattern opposite to that of an electrode to be formed on a conductive plate material. (2) A step of plating an electrode material on a conductive portion of the transfer substrate other than the insulating layer. (3) A step of facing the transfer substrate and a glass substrate and bonding only the pattern of the electrode material to the glass substrate by an anodic bonding method.

When the electrode material is electroplated on the above-mentioned transfer substrate, the conductive portion without the insulating layer can be plated, but the portion hidden by the insulating layer is not plated. Therefore,
If the pattern of the insulating layer is formed on the plate material in advance, the electrode material can be plated in a desired pattern. Then, this electrode material is bonded onto the glass substrate by the anodic bonding method. That is, the transfer substrate having the electrode material formed on the conductive portion other than the insulating layer and the glass substrate are opposed to each other, and the surfaces of both substrates are brought into contact with each other by heating and applying a voltage of several hundreds of V, and the electrode material Only are physically bonded to the glass substrate.

[0007]

DETAILED DESCRIPTION OF THE INVENTION An electrode pattern forming method of the present invention will be described with reference to FIGS.

First, as shown in FIG. 1, an insulating layer 2 having a pattern opposite to that of an electrode to be formed is formed on a plate material 1 having conductivity, and a transfer substrate 3 is manufactured.

The plate material 1 used for the transfer substrate 3 is required to have a flat surface and to have an equal elongation as much as possible due to thermal expansion during bonding with the glass substrate. Therefore, as the plate material 1 of the transfer substrate 3, a glass plate having a conductive layer on its surface, SUS, Invar 36 (F
e: Ni = 64: 36), Invar 42 (Fe: Ni =
58:42), Kovar (Fe: Ni: Co = 54: 2)
9:17), materials such as Ti are preferable. Further, it is preferable that the surface roughness (Rmax) is polished to 1000 Å or less. Examples of this polishing method include a lapping polishing method and an electric field composite polishing method.

The insulating layer 2 has an insulating film formed on the plate material 1,
It is obtained by patterning the insulating film by a photolithography method. As the insulating film, a SiNx film or SiOx film formed by a CVD method, a SiNx film formed by a reactive vapor deposition film, a SiOx film or a shot glass film, a coating glass, a coating film of a ceramic precursor polymer, a curable resin, etc. (baked if necessary), etc. Is used. Examples of ceramic precursor polymers include silazane polymers and silanol compounds. The photolithography method is
Specifically, after performing the steps of forming a resist film, exposing through a mask, and developing, a step of etching the insulating film by dry etching is taken. Note that dry etching can be performed with a high aspect ratio by performing reactive ion etching. After that, the resist is peeled off to complete the transfer substrate 3 on which the insulating layer 2 having a pattern opposite to the electrode to be formed is formed on the plate material 1 as shown in FIG.

As another method for producing the transfer substrate, a portion of the plate material where the insulating layer is to be formed may be previously etched to form a recess, and the insulating layer may be formed in the recess. In this case, a photoresist layer is patterned on the plate material, the surface of the plate material corresponding to the pattern openings is etched to form recesses, and then an insulating layer is formed on the entire surface, and then the photoresist layer and the photoresist layer are formed thereon. It is simpler to adopt the method of peeling the insulating layer (lift-off method).

After the transfer substrate 3 is manufactured as described above, as shown in FIG. 2, the electrode material 4 is plated on the conductive portions of the transfer substrate 3 other than the insulating layer 2.

The electrode material 4 is Au among transition metals.
It is necessary to use a material other than a metal that does not oxidize, such as Pt and Pt, or a metal that becomes ions that can move in the glass, such as Ag, and that can be plated. Therefore, C
u, Zn, Cr, Fe, Co, Ni, Cd, In, Sn
And the like are preferably used. Among these, a nickel film using a nickel sulfamate plating solution is preferable in order to reduce the internal stress of the plating film in particular. Further, if necessary, an additive may be added in order to achieve smoothness of the plated film surface. As the additive, brighteners # 61, # 63, # 610 and wetting agent # 62, which are preferably manufactured by Ebara Eugelite, are preferably used.
Is mentioned.

When SUS is used for the plate material 1, passivation treatment is performed after cleaning and degreasing treatment. As a result, a passivation film is formed on the SUS surface, and the plating film formed thereon can be easily peeled off. As an example of this passivation treatment, 50 g / l of "Economy cleaner (12% by weight sodium phosphate, 41% by weight sodium silicate, 42.5% by weight sodium carbonate, 4.5% by weight anionic activator)" manufactured by Murata The SUS substrate may be dipped in the aqueous solution of 1 to be treated at a current density of 1 mA / cm ² for 10 minutes. Further, the passivation treatment can also be performed by anodic oxidation with an aqueous citric acid solution.

On the other hand, when Invar or Kovar is used for the plate 1, the plate 1 is first plated with Ni (0.5 to 5).
μm: Adhesion to the substrate, peeling is not possible), then chromic acid treatment (5-60 in 1 wt% potassium dichromate aqueous solution)
It is preferable to perform Ni plating (5 to 20 μm: peelable) again after the second dipping: passivation film formation), because the electrode material 4 can be transferred from the transfer substrate 3 smoothly.

Next, as shown in FIG. 3, the transfer substrate 3 and the glass substrate 5 are opposed to each other, and only the pattern of the electrode material 4 is bonded to the glass substrate 5 by the anodic bonding method.

This joining method is performed as follows. As shown in the figure, when a negative voltage of several hundreds V is applied to the glass substrate 5 side, the alkali ions in the glass are moved by the electric field and a space charge layer of negative charge is generated near the interface. At this time, the glass substrate 5 and the transfer substrate 3 are attracted by electrostatic attraction, the voltage applied to the space charge layer further increases, and the charging current flows during that time. Eventually, the glass substrate 5 and the transfer substrate 3 come into contact with each other, and oxygen ions in the space charge layer partially move due to a strong electric field, and then the electrode material 4 and oxygen of the glass substrate 5 form a covalent bond at the interface. At this time, the applied voltage is entirely applied to the space charge layer, the electrostatic attraction is maximized, and the current stops flowing. Finally, the transfer substrate 3 and the glass substrate 5 to which the electrode material 4 is bonded by the anodic bonding method are peeled off to obtain the glass substrate 5 on which the pattern of the electrode material 4 as shown in FIG. 4 is transferred.

Since the anodic bonding method is performed in this manner, as described above, as the electrode material 4, a metal that does not oxidize such as Au or Pt or a metal that becomes an ion that can move in the glass such as Ag is used. Can not. Further, regarding the glass substrate 5 to which the electrode pattern is transferred, a large amount of an alkali component such as an alkali metal in the glass increases the electrostatic attractive force and leads to bonding at a low temperature. Therefore, the alkali component is preferably 10% or more.

[0019]

【Example】

(Example 1) As a conductive plate material, the surface was polished by an electrolytic composite polishing method to obtain a surface roughness (Rmax) of 0.0.
A 3 mm thick stainless plate having a thickness of 3 mm was prepared. This was passivated by the above-mentioned method using "Economy Cleaner" manufactured by Murata.

Next, a coating liquid for forming a SiO ₂ film (“OCD-Type 7” manufactured by Tokyo Ohka Kogyo Co., Ltd.) was applied to this plate material and baked at 450 ° C. to form an insulating film. Then, a resist (“OFPR80” manufactured by Tokyo Ohka Kogyo Co., Ltd. is formed on the insulating film.
0 ") was applied, exposure and development were performed through the mask to form an etching mask having openings corresponding to the electrode pattern to be formed. Then, through this etching mask, dry etching method (“DE
A-506T "was used) to pattern the insulating film, and then the resist was removed by ultrasonic cleaning using an organic solvent. In this way, a transfer substrate having an opening corresponding to the electrode pattern was produced.

Next, the transfer substrate and the Ni electrode are placed facing each other and immersed in a plating bath having the following composition, and the Ni electrode is connected to the direct current anode and the transfer substrate is connected to the cathode, respectively, at 1 A / cm. Apply current for 3 minutes at a current density of ² and apply N of 3 μm thickness to the bare part of the plate that is not covered with an insulating layer.
An i-plated film was formed.

(Example of composition of plating bath) Plating solution: Nickel sulfamate 350 g / l (manufactured by Nippon Kagaku Sangyo) Additive: Brightener # 61 (manufactured by EBARA Eugelite) (timely replenishment) Brightener # 63 (Ebara Euge) Light) 10 to 15 ml / l Brightening agent # 610 (made by Ebara Eugelite) 3 to 7 ml / l Wetting agent # 62 (made by Ebara Eugelite) 0.5 to 3 ml / l pH buffer: boric acid 40 g / l

Of the above additives, especially brightener # 61,
The internal stress of the plated film can be controlled by adjusting # 63.

Subsequently, Ni formed on the transfer substrate
The glass substrate (“blue sheet glass” manufactured by Asahi Glass) was faced to be in contact with the plating film, and the plating film was bonded to the glass substrate by an anodic bonding method. Specifically, the anode of the DC power source is connected to the transfer substrate and the cathode is connected to the glass substrate, respectively.
A negative voltage of 0V was applied. As a result, an electrostatic attractive force was generated between the transfer substrate (specifically, the electrode formed by plating on the transfer substrate) and the glass substrate, and chemical bonding occurred at the interface to bond the plated film to the glass substrate. The heating temperature at that time is 350 ° C. Finally, the transfer substrate was peeled off to form an electrode pattern on the glass substrate.

(Example 2) Ti plate material (thickness: 0.4 m)
m) on the surface by spin coating (rotation speed 1500 rpm,
For 40 seconds, a photoresist (“O” manufactured by Tokyo Ohka Kogyo Co., Ltd.
FPR800 ″), and then exposed and developed through a mask having a line width of 5 μm and a predetermined shape to form an etching mask having openings corresponding to the electrode pattern to be formed.

Then, HF (2.5 wt%)-H ₂ O ₂
The bare portion of the plate material is etched (2 seconds, etching depth 2 μm) in a (15 wt%) solution, and then immersed in a HF-NH ₄ F solution (30 seconds for improving the adhesion of the insulating layer to the substrate). ) And roughened the surface of the plate material.

Next, a ceramic precursor polymer ("PHPS-1" manufactured by Tonen) was applied onto this substrate by a spin coating method (rotation speed 1500 rpm, 20 seconds) and was temporarily placed in an oven (80 ° C, 30 minutes). After baking, the resist and the ceramic precursor polymer formed thereon were removed by using ultrasonic waves in acetone. Then, the substrate was baked (400 ° C., 1 hour in the air) to form a transfer substrate having a ceramic insulating layer.

Thereafter, in the same manner as in Example 1, a Ni plating film was formed on the transfer substrate, the plating film was bonded to the glass substrate by the anodic bonding method, and finally the transfer substrate was peeled to remove the glass. An electrode pattern was formed on the substrate.

[0029]

As described above, according to the present invention,
Since the electrode material pattern is formed on the transfer substrate by the plating method and only the electrode material pattern is bonded to the glass substrate by the anodic bonding method to form the electrode pattern, the conventional plating pattern transfer method is used. As described above, it is not necessary to provide a sticky or adhesive insulating resin layer, and an electrode pattern having resistance to heat treatment such as firing can be formed.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a transfer substrate.

FIG. 2 is a cross-sectional view showing a state in which a conductive portion of a transfer substrate is plated with an electrode material.

FIG. 3 is an explanatory diagram showing an anodic bonding method.

FIG. 4 is a cross-sectional view showing a glass substrate on which an electrode pattern is transferred.

[Explanation of symbols]

 1 plate material 2 insulating layer 3 transfer substrate 4 electrode material 5 glass substrate

Claims (1)

[Claims] 1. An electrode pattern forming method comprising at least the following steps. (1) A step of forming a transfer substrate by forming an insulating layer having a pattern opposite to that of an electrode to be formed on a conductive plate material. (2) A step of plating an electrode material on a conductive portion of the transfer substrate other than the insulating layer. (3) A step of facing the transfer substrate and a glass substrate and bonding only the pattern of the electrode material to the glass substrate by an anodic bonding method.