JP4649557B2 - Wiring manufacturing method - Google Patents

Description

  The present invention relates to a method for forming a metal wiring by a plating method on a desired surface region such as a glass substrate, a substrate having an insulating film formed on the glass substrate, or a resinous substrate.

  As a method of forming wiring on the surface of a glass substrate or plastic substrate, generally, after forming a wiring metal on the substrate by plating or sputtering, a photosensitive resin is applied, exposed and developed, and then etched. A method of patterning into a desired shape is performed by such a method.

  Also, a method of embedding a wiring metal in a groove formed by applying a photosensitive resin on a substrate and patterning the photosensitive resin into a desired shape by etching or the like is performed by an electroless plating method or the like.

  FIG. 5 is a diagram showing a flow of a conventional general electroless plating method on a glass substrate or a plastic substrate. In FIG. 5, the glass substrate and plastic are washed, then degreased with an alkaline solution, subjected to surface etching with an acid solution, and then subjected to photosensitive resin coating and patterning, followed by application of a catalyst. The sensitizing treatment liquid immersion and the catalyst imparting liquid immersion are performed, and the immersion is further performed in the electroless plating liquid.

FIG. 6 is a schematic view of the state of a solution containing nickel, which is a typical metal for electroless plating, depending on the pH and oxidation-reduction potential. An alkaline solution with a high pH shows nickel precipitation in a region where the absolute value of the oxidation-reduction potential is relatively large, and an acidic solution with a low pH shows precipitation of nickel in a region where the absolute value of the oxidation-reduction potential is relatively small. It has been known. Note that examples of documents described in the prior art include the following documents.
Japanese Patent Laid-Open No. 2001-203448 “Multilayer Printed Wiring Board and Manufacturing Method Thereof” JP 2000-294926 “Manufacturing method of multilayer printed wiring board”

  There are a number of problems with the conventional method described above. That is, on the surface of a glass substrate or plastic substrate, a wiring metal is formed on the substrate by plating or sputtering, then a photosensitive resin is applied, exposed and developed, and then patterned into a desired shape by etching or other methods. In this method, the metal film formed by sputtering is etched, and the photosensitive resin is peeled off to form the wiring. Therefore, the photosensitive resin material in most areas where the wiring is not formed is discarded. The efficiency is reduced.

  Further, in the wiring formed in this way, when the wiring thickness is increased for the purpose of reducing resistance and parasitic capacitance, the step between the metal wiring and the substrate becomes large, resulting in poor alignment of the liquid crystal and TFT leakage. This will cause problems such as an increase in current.

  In addition, since the wiring metal sputtering step includes a decompression step, there is a problem that an increase in process cost and process time is inevitable as the glass substrate becomes larger.

  On the other hand, in the method of embedding the wiring metal in the groove of the photosensitive resin on the substrate by the electroless plating method without using the decompression step (see FIG. 5), the surface potential of the glass substrate or plastic substrate viewed from the solution is If it is sufficiently lower than the surface potential of the photosensitive resin as seen from the solution, the potential state of the solution containing metal ions is set to the middle of those potentials, so that only the surface of the glass or plastic substrate Metal can be deposited and selective plating can be performed without causing deposition on the surface of the photosensitive resin.

  However, unless there is a sufficient difference between the surface potentials of the two, it is difficult to control the solution containing metal ions to the potential between them, and it will be deposited on both the glass surface and the photosensitive resin surface. Become.

  Further, even when there is a sufficient difference between the potentials of both surfaces, unless the oxidation-reduction potential of the solution containing metal ions is controlled to be substantially constant, the oxidation-reduction potential changes with the passage of process time, If the oxidation-reduction potential is lower than any surface, it will precipitate on both surfaces, and if it is higher than any surface, no precipitation will be obtained on either surface.

  Further, in the formation of wirings in a semiconductor integrated circuit, a method is employed in which a seed layer is also formed by sputtering, and the film thickness is increased by electrolytic plating using this as an electrode.

Although it is inherently more advantageous in terms of process to form the seed layer using the electroless plating method, the reason for using the sputtering method without using this is that the adhesion to the substrate is sufficient. This is because it is necessary to use a substance that adversely affects device characteristics such as a transistor as a reducing agent, a stabilizer, etc. in the electroless plating method.
The present invention has been made for the purpose of solving such problems.

In order to solve the above problems, the invention claimed in the present application is as follows.
(1) A substrate having a photosensitive resin layer formed on a substrate, and having a region G1 where the substrate is exposed by exposing and developing at least a part of the photosensitive resin and a region R1 where the photosensitive resin remains. A wiring formation method by electroless plating performed on
(IA) Using a cationic surfactant, a potential difference forming process for making the surface potential in the photosensitive resin region R1 more positive than that in the substrate exposed region G1,
(IB) After the potential difference forming process,
(IB-1) a catalyst nucleus imparting solution having a redox potential that is more positive than the surface potential of the substrate exposed region G1 and more negative than the surface potential of the photosensitive resin region R1, and
(IB-2) Application of catalyst nuclei to be treated using an electroless plating solution having a redox potential that is more positive than the surface potential of the substrate exposed region G1 and more negative than the surface potential of the photosensitive resin region R1. And plating process,
A wiring formation method characterized in that a substrate on which wiring is formed is obtained.
(2) A photosensitive resin layer is formed on a substrate, and at least a part of the photosensitive resin is exposed and developed to have a region G1 where the substrate is exposed and a region R1 where the photosensitive resin remains. In the wiring formation method by electroless plating performed on the photosensitive resin region R1, the surface potential of the photosensitive resin region R1 is more positive than the substrate exposed region G1 by the cationic surfactant treatment, and the surface potential of the substrate exposed region G1 is increased. A wiring formation method using a catalyst nucleus imparting solution and an electroless plating solution having an oxidation-reduction potential that is more positive than the surface potential of the photosensitive resin region R1 and more negative than the surface potential of the photosensitive resin region R1.
(3) The treatment in the potential difference forming process or the cationic surfactant treatment is such that the potential difference between the photosensitive resin region R1 and the substrate exposed region G1 is 0.05 V or more, preferably 0.1 V or more. The wiring formation method according to (1) or (2), characterized in that:
(4) The wiring according to any one of (1) to (3), wherein the substrate is any one of a glass substrate, a substrate having an insulating film formed on the glass substrate, and a resinous substrate. Forming method.
( 5 ) The catalyst nucleus-imparting liquid is obtained by dissolving a compound serving as a catalyst nucleus in ozone-added water whose pH and oxidation-reduction potential are controlled. Any one of (1) to ( 4 ), A method of forming a wiring according to claim 1.
( 6 ) The electroless plating solution is obtained by dissolving metal ions to be precipitated in ozone-added water or hydrogenated water with controlled pH and oxidation-reduction potential, (1) to ( 5 ) The wiring formation method according to any one of the above.
( 7 ) The substrate is preliminarily immersed in hydrofluoric acid or a solution containing hydrofluoric acid in the solute, and the substrate exposed region G1 and the photosensitive resin region R1 are formed with a photosensitive resin. The wiring formation method according to any one of 1) to ( 5 ).
( 8 ) The substrate is dipped in hydrofluoric acid or a solution containing fluoric acid in the solute prepared in the range of 0.05% to 0.1% in the range of 3 seconds to 10 seconds. The wiring formation method according to any one of (1) to ( 5 ), characterized in that the substrate exposed region G1 and the photosensitive resin region R1 are formed of a conductive resin.
(9) The wiring forming method according to any one of (1) to ( 5 ), wherein the substrate is preliminarily immersed in an alkaline solution, and G1 and R1 are formed on the substrate with a photosensitive resin.
(10) The substrate is dipped in an alkali solution adjusted in advance in a range of 10% to 20% in a range of 3 minutes to 10 minutes, and G1 and R1 are formed with a photosensitive resin thereon. The wiring formation method according to any one of (1) to ( 5 ).
In these inventions (1) to (10),% is% by weight (the same applies to the following).

In addition to the above inventions, the following are also included in the present invention.
(5 ') said substrate, characterized in that it is dipped in advance alkaline solution prior to cationic surfactant treatment, the wiring forming method according to any one of (1) to (4).
(6 ') said substrate, characterized in that it is dipped in the range of advance 10% of the alkaline solution that has been adjusted in the range of 20% to 10 minutes 3 minutes prior to cationic surfactant treatment, (1) The wiring formation method according to any one of (5).
(9 ′) The substrate is immersed in hydrofluoric acid or a solution containing hydrofluoric acid in the solute after the cationic surfactant treatment, (1) , (2), (3) , (4), (7) or (8) .
(10 ′) The substrate was treated with a hydrofluoric acid adjusted to a range of 0.05% to 0.1% or a solution containing hydrofluoric acid in the solute for 3 to 10 seconds after the cationic surfactant treatment. The wiring forming method according to any one of (1) , (2), (3), (4), (7), (8), and (9) , characterized by being immersed in a range.

Furthermore, the present invention includes the following inventions.
(11) is formed a photosensitive resin layer on a substrate has a region R1 at least partially exposed and developed by the region G1 which exposed the base photosensitive resin is left of the photosensitive resin, no a substrate which can be subjected to electrolytic plating process, the substrate, by being dipped in a cationic surfactant after the photosensitive resin coating, between the substrate exposed region G1 and the photosensitive resin region R1 A substrate for electroless plating, which is provided with a potential difference.
(12) is formed a photosensitive resin layer on a substrate has a region R1 at least partially exposed and developed by the region G1 which exposed the base photosensitive resin is left of the photosensitive resin, no a method of forming a substrate that can be subjected to electrolytic plating process, the method, by being dipped in a cationic surfactant after the photosensitive resin coating, and the substrate exposed region G1 and the photosensitive resin region R1 A method for forming a substrate for electroless plating, characterized by providing a potential difference between the two.

That is, the present invention is a photosensitive resin is formed on a substrate, said substrate having a region R1 in which at least a portion of the exposed and developed with region G1 which exposed the base photosensitive resin is left of the photosensitive resin in, photosensitive resin region R1 surface potential than the substrate exposed region G1 is positively by cationic detergent treatment, the positive side than the surface potential of the G1, and than the surface potential of the R1 A wiring formation method using a catalyst nucleus imparting solution having a negative oxidation-reduction potential and an electroless plating solution.

Further, examples of the substrate, a glass substrate, a substrate having an insulating film formed on a glass substrate, a resin substrate.
Moreover, as a catalyst nucleus provision liquid, what is obtained by melt | dissolving the compound used as a catalyst nucleus in the ozone addition water which controlled pH can be used.
Further, as the electroless plating solution, a solution obtained by dissolving metal ions to be precipitated in ozone-added water with controlled pH or hydrogenated water with controlled pH can be used.
Further, the substrate may be obtained by being immersed in 3 minutes in the 10 minute range in the alkaline solution is adjusted in a range from advance 10% to 20% to form a G1 and R1 in the photosensitive resin thereto.
Further, the substrate is obtained by being dipped in a range hydrofluoric acid or hydrofluoric acid which is adjusted in a range from a pre-0.05% 0.1% 3 seconds in a solution containing its solute 10 seconds, to G1 and R1 can be formed with a photosensitive resin.

  According to the method of the present invention, since the photosensitive resin is used for creating the wiring, the wiring creating region can be determined simply by developing the photosensitive resin. The photosensitive resin peeled or dissolved by development can be easily regenerated because only the wiring region having a relatively small area ratio is discarded and does not contain impurities such as metal.

  Also, the step between the surface of the wiring metal embedded in the photosensitive resin and the surface of the photosensitive resin is reduced, and the thickness of the wiring can be determined by the film thickness of the photosensitive resin. Wiring can be created and formed so as not to adversely affect the alignment characteristics and the electrical characteristics of the transistor.

  In addition, since the present invention does not include a decompression step, an increase in process cost can be suppressed even when the substrate is large, as compared with wiring formation using a conventional sputtering method.

  Further, in the present invention, ozone-added water is used in preparing a catalyst nucleus imparting solution that is indispensable for electroless plating, and the electroless plating solution contains a desired metal in ozone-added water or hydrogenated water. By dissolving the compound, it is possible to eliminate the use of a large amount of an acid / alkali solvent as has been done in conventional electroless plating.

  At the same time, by controlling the amount of carbon dioxide gas or the like dissolved in the ozone-added water, it is possible to control the pH on the acidic side, and by controlling the amount of ammonia gas or the like dissolved in the hydrogen-added water. Since the pH can be controlled to the acidic side, the waste liquid can be treated very easily. Here, each said gas is an illustration, and if it is a gas which can be used for pH control in this invention, an appropriate | suitable thing can be used.

FIG. 1 is a flowchart showing the basic configuration of the wiring forming method of the present invention. The method in FIG. Is a photosensitive resin layer is formed on a substrate, said having at least a portion of the exposed and developed to expose the said base region and a photosensitive resin is left area of the photosensitive resin A wiring formation method by electroless plating performed on the substrate U, the method comprising:
Using (IA) cationic surface active agents, and the potential difference formation process SIA for the surface potential of the photosensitive resin region more positive than that in the substrate exposed region,
(IB) After the potential difference forming process SIA,
(IB-1) said substrate is more positive than the surface potential of the exposed region and catalytic core imparting solution having a redox potential of more negative than the surface potential of the photosensitive resin region, and,
(IB-2) the substrate exposed area catalyst nucleus applied and plating processes positive a and using an electroless plating solution having a redox potential of more negative than the surface potential of the photosensitive resin region than the surface potential of the Process SIB,
It is basically composed.

With this configuration, the surface potential in the photosensitive resin region is made more positive than that in the substrate exposed region by the potential difference formation process SIA, then by the catalyst nucleus applied and plating processes SIB, relative potential difference formed substrate The catalyst core is applied and the plating process is performed to obtain the base P on which the wiring is formed. The catalyst nucleus application and plating process SIB includes a catalyst nucleus application process SIB-1 and a plating process SIB-2.

  Examples of the cationic surfactant used in the present invention include an amine salt type, a quaternary ammonium salt type, a pyridinium salt type, and the like.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited by the specific conditions shown by these Examples and Examples.

A wiring manufacturing method according to the first embodiment of the present invention will be described with reference to FIG.
FIG. 3 is a process diagram of the wiring manufacturing method of the first embodiment, and non-alkali glass was used for the glass substrate. Here, silica glass having a relatively small heat shrinkage rate may be used.

  A desired wiring formation region G1 was obtained by applying a photosensitive resin to the surface of alkali-free glass and developing after exposure. The photosensitive resin used here is selected from those having a sufficiently high light transmittance in a desired light wavelength region. Here, a resin mainly composed of cycloolefin was used.

  A glass substrate having the region G1 and the photosensitive resin region R1 remaining after development was immersed in a 15% potassium hydroxide solution for 5 minutes, and then washed with pure water. The solution used here is an alkaline solution adjusted in advance in the range of 10% to 20%, and the same effect can be obtained if the immersion time is in the range of 3 minutes to 10 minutes. In addition, as temperature conditions, it carried out at room temperature (the same applies below).

Further, this substrate was immersed in 0.05% cationic surfactant for 1 minute and then immersed in a 0.1% hydrofluoric acid solution for 5 seconds, and the surface potential of the photosensitive resin region R1 was changed from that of the substrate exposed region G1. Was also positive. At this time, the cationic surfactant adhering to the glass surface was removed by etching the glass with hydrofluoric acid to obtain a substrate having an increased surface potential difference between the glass surface and the photosensitive resin surface. The acidic solution used here is a solution containing hydrofluoric acid or hydrofluoric acid adjusted in the range of 0.05% to 0.1% in the solute, and the immersion time is the same if it is in the range of 3 seconds to 10 seconds. The effect is obtained.

  Next, the substrate was washed with a solution prepared with tin chloride and hydrochloric acid, and washed and then immersed in a solution prepared with palladium chloride and hydrochloric acid for 1 minute each to obtain a substrate having the catalyst nucleus attached only to the exposed glass surface. The catalyst nucleus imparting solution used here has a redox potential that is more positive than the surface potential of G1 and more negative than the surface potential of R1.

  This was immersed in an electroless plating solution in which nickel ions were dissolved to deposit nickel only on the desired glass exposed surface. The electroless plating solution used here has a redox potential that is more positive than the surface potential of G1 and more negative than the surface potential of R1. Nickel was controlled to fill the groove of the photosensitive resin and finish the deposition at the same height as the surface of the photosensitive resin, so that the surface of the metal wiring and the surface of the photosensitive resin were almost flat.

A wiring manufacturing method according to the second embodiment of the present invention will be described with reference to FIG.
Figure 3 shows the preparation of preparation and the electroless plating solution of the catalyst nuclei imparting solution in Example 2.

Manufacturing process, an alkaline solution as shown in Example 1, after passing through an acid solution treatment step, by dissolving a palladium chloride-tin solution to the ozone added water prepared by dissolving tin chloride, and the ozone-containing water Each of the glass substrates was immersed for 1 minute in the resulting catalyst nucleus imparting solution to obtain a substrate having the catalyst nuclei attached only to the exposed glass surface. The solution used here has a redox potential that is more positive than the surface potential of G1 and more negative than the surface potential of R1.

Nickel sulfate was dissolved in an alkaline hydrogen water-added water in which the prepared ammonia gas was dissolved to form a plating solution. The previously obtained substrate was immersed in this for 1 minute to deposit nickel only on the glass surface. The solution used here has a redox potential that is more positive than the surface potential of G1 and more negative than the surface potential of R1. Nickel was controlled to fill the groove of the photosensitive resin and finish the deposition at the same height as the surface of the photosensitive resin, so that the surface of the metal wiring and the surface of the photosensitive resin were almost flat.

A wiring manufacturing method according to the third embodiment of the present invention will be described with reference to FIG.
FIG. 4 shows a process for producing a photosensitive resin region on the substrate surface in Example 3.

  Preparation of the photosensitive resin area | region in the board | substrate surface performed temporary drying after photosensitive resin application | coating, Then, it immersed in 0.05% cationic surfactant for 1 minute, and performed through the process of exposure and image development after that.

  The obtained substrate is not provided with a surfactant on the glass exposed surface, but is provided only on the surface of the photosensitive resin region, and the surface potential of this region is more positive than the glass exposed region G1. Yes.

  By subjecting the substrate to the catalyzing imparting step in Example 1 and Example 2 and the electroless plating step, nickel can be deposited only in the glass exposed region of the substrate.

In the first, second and third embodiments, the photosensitive resin region R1 has a positive surface potential as compared with the substrate exposed region G1 by the cationic surfactant treatment, but the potential difference at this time is 0.05V. As described above, preferably 0.1 V or more, a sufficient effect can be obtained. Furthermore, the potentials of the catalyst nucleus imparting solution and the electroless plating solution having a redox potential that is positive with respect to the surface potential of G1 and negative with respect to the surface potential of R1 are substantially intermediate between those of R1 and G1. It is more preferable to control the potential in order to maximize the selectivity of wiring formation.
Each of the above embodiments uses a glass substrate, but wiring is formed in the same manner on a glass substrate having an insulating film formed on its surface, a plastic substrate such as plastic, or other substrates. be able to.

Moreover, in the said Example, although nickel is used as a wiring metal, copper, chromium, and another metal can be used without being specifically limited. For example, when it is necessary to lower the wiring resistance, the metal can be selected as appropriate, such as using copper as the metal having a low resistivity.
In the above embodiment, the wiring metal is formed by the electroless plating method. However, in order to improve the wiring formation speed, the electroless plating method and the electroplating method may be combined.

  According to the present invention, it is possible to form a wiring on a glass substrate without using a conventional decompression process, and it can be applied to a liquid crystal TFT substrate, an organic EL display wiring, a plasma display wiring, a semiconductor substrate, a ceramic substrate, a circuit substrate, and the like. Application is possible.

The flowchart which shows the structure of the wiring formation method of this invention Process drawing of Example 1 of this invention Process drawing of Example 2 of this invention Photosensitive resin region production process diagram of Example 3 of the present invention Process diagram of wiring formation by electroless plating on general glass substrate and plastic substrate Schematic diagram of nickel pH and redox potential

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Substrate exposed surface 2 Photosensitive resin surface 3 Precipitated metal U Pretreatment substrate SIA Potential difference formation process SIB Catalyst nucleus application and plating process SIB-1 Catalyst nucleus application process SIB-2 Plating process P Substrate with wiring formed

Claims (10)

A photosensitive resin layer is formed on a substrate, and the substrate having a region G1 where the substrate is exposed by exposing and developing at least a part of the photosensitive resin and a region R1 where the photosensitive resin is left. A method of forming a wiring by electroless plating, the method comprising:
(IA) Using a cationic surfactant, a potential difference forming process for making the surface potential in the photosensitive resin region R1 more positive than that in the substrate exposed region G1,
(IB) After the potential difference forming process,
(IB-1) a catalyst nucleus imparting solution having a redox potential that is more positive than the surface potential of the substrate exposed region G1 and more negative than the surface potential of the photosensitive resin region R1, and
(IB-2) Application of catalyst nuclei to be treated using an electroless plating solution having a redox potential that is more positive than the surface potential of the substrate exposed region G1 and more negative than the surface potential of the photosensitive resin region R1. And plating process,
A wiring formation method characterized in that a substrate on which wiring is formed is obtained. A photosensitive resin layer is formed on a substrate, and at least a part of the photosensitive resin is exposed to light and developed, and this is performed on the substrate having a region G1 where the substrate is exposed and a region R1 where the photosensitive resin remains. In the wiring forming method by electroless plating, the photosensitive resin region R1 has a surface potential more positive than the substrate exposed region G1 by the cationic surfactant treatment, and is more positive than the surface potential of the substrate exposed region G1. A method of forming a wiring, comprising using a catalyst nucleus imparting solution and an electroless plating solution having a redox potential on the side and on the negative side of the surface potential of the photosensitive resin region R1. The treatment in the potential difference forming process or the cationic surfactant treatment is performed so that the potential difference between the photosensitive resin region R1 and the substrate exposed region G1 is 0.05 V or more, preferably 0.1 V or more. The wiring formation method according to claim 1, wherein: 4. The wiring forming method according to claim 1, wherein the base is any one of a glass substrate, a substrate having an insulating film formed on the glass substrate, and a resinous substrate. Catalyst nuclei imparting solution is characterized in that is obtained by dissolving the compound of the catalyst nucleus in ozone-containing water having a controlled pH and redox potential, the wiring of any one of claims 1 to 4 Forming method. Electroless plating solution, the ozone-containing water or hydrogenated water to control the pH and redox potential, characterized in that obtained by dissolving the metal ions to be deposited, any one of claims 1 to 5 The wiring formation method of description.
The substrate is preliminarily immersed in hydrofluoric acid or a solution containing hydrofluoric acid in a solute, and a substrate exposed region G1 and a photosensitive resin region R1 are formed on the substrate with a photosensitive resin. The wiring formation method according to any one of 5 . The substrate is dipped in hydrofluoric acid or a solution containing hydrofluoric acid in the solute in a range of 0.05% to 0.1% in a range of 3 seconds to 10 seconds. and forming a substrate exposed area G1 and the photosensitive resin region R1, the wiring forming method according to any one of claims 1 to 5.
It said substrate is dipped in advance alkaline solution, and forming a G1 and R1 in the photosensitive resin to the wiring formation method according to any one of claims 1 to 5. The substrate is dipped in an alkaline solution adjusted in advance in a range of 10% to 20% in a range of 3 minutes to 10 minutes, and G1 and R1 are formed on the photosensitive resin by using this. Item 6. The wiring forming method according to any one of Items 1 to 5 .

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