JP2013065680A - Manufacturing method of electronic circuit and electronic circuit board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of an electronic circuit, capable of forming an electronic circuit with a few kinds of materials, and to provide an electronic circuit board.SOLUTION: A conductor 43 which connects between electronic components in an electronic circuit is formed by coating a liquid L, containing metal particles, on a substrate. A resistor 42 having electric resistance higher than that of the conductor 43 is formed by coating the liquid L on the substrate and oxidizing the metal particles contained in the liquid L. Thus, the conductor 43 and the resistor 42 are formed from a same material and an electronic circuit can be formed with a few kinds of materials.

Description

  The present invention relates to a method for manufacturing an electronic circuit having a resistor as an electronic component and an electronic circuit board.

  In general, as a method for forming a conductive film on a substrate, various methods such as an evaporation method, a sputtering method, a spin coating method, a printing method such as screen printing and offset printing, and an ink jet method are known.

  For example, in Patent Document 1, a plurality of pattern forming materials such as a semiconductive material and a conductive material are applied and solidified on a substrate by an inkjet head to form a conductor (wiring) and a resistor (resistor). Is described.

Japanese Patent Laid-Open No. 11-274671

  However, if a pattern forming material is prepared for each component to be formed on a substrate such as a conductor and a resistor as in the method of manufacturing an electronic circuit described in Patent Document 1, a large number of pattern forming materials are required. Labor and time are required for development.

  Further, in a method typified by the inkjet method or the printing method, a conductive film is formed by directly applying a liquid containing a conductive material over a substrate. Therefore, when the pattern forming material to be used increases, there is a problem that the device structure, device control, and the like become complicated.

  For example, in the case of the ink jet method, it is necessary to provide an ink jet head for each pattern forming material, and the control becomes complicated by increasing the number of ink jet heads.

  Therefore, an object of the present invention is to provide an electronic circuit manufacturing method and an electronic circuit board in which an electronic circuit is formed with a small number of materials.

  The present invention relates to a method of manufacturing an electronic circuit in which an electronic component is connected by a conductor to form a circuit, and the electronic component has a resistor having a higher electrical resistance than the conductor, and the conductor includes metal particles. The resistor is formed by applying a liquid onto a substrate, and the resistor is formed by applying the liquid onto the substrate and oxidizing the metal particles contained in the liquid.

  Further, in an electronic circuit board on which an electronic circuit having a resistor having a higher electrical resistance than the conductor is formed as an electronic component connected by a conductor, the conductor is a liquid containing metal particles solidified on the board. The resistor is formed by oxidizing metal particles of the conductor.

  According to the present invention, a liquid containing metal particles is used as a pattern forming material, and this liquid is applied onto a substrate to form a conductor. Further, since the resistor is formed by oxidizing the liquid metal particles forming the conductor and increasing the electric resistance, the conductor and the resistor can be formed using the same pattern forming material. As a result, the pattern forming material used when forming the electronic circuit can be reduced, and the structure and control of the electronic circuit manufacturing apparatus can be simplified because there are few types of pattern forming materials. .

The schematic diagram of the electronic circuit manufacturing apparatus which concerns on embodiment of this invention. Sectional drawing which shows the electronic circuit board which concerns on embodiment of this invention. It is a figure which shows the manufacturing process of an electronic circuit board, Comprising: (a) is a figure which shows the state before wiring, (b) is a figure which shows the state which wired the conductor between electrodes, (c) Masks the conductor, The figure which shows the state which oxidized the part which forms a resistor, (d) The figure which shows the state which removed the mask. The flowchart figure which shows the manufacturing method of the 1st electronic circuit board. The flowchart figure which shows the manufacturing method of a 2nd electronic circuit board. The flowchart figure which shows the manufacturing method of a 3rd electronic circuit board.

[Configuration of electronic circuit manufacturing equipment]
Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 6. In the following description, an electronic component means a component that is generally connected by a conductor on an electronic circuit, such as an electronic element or a sensor. Specifically, the electronic elements are resistors (resistors), transistors, capacitors, electrodes, and the like, and the sensors are display device elements, flow sensors, pressure sensors, image sensors, and the like.

  First, based on FIG. 1, the structure of the electronic circuit manufacturing apparatus used in this Embodiment is demonstrated. As shown in FIG. 1, the electronic circuit manufacturing apparatus is configured by an ink jet apparatus 1. The ink jet device 1 includes a stage device 2 on which an electronic circuit board (hereinafter also simply referred to as a substrate) W is placed, a drawing unit 10 that draws an electronic circuit on the substrate, and a control device that controls the drawing unit 10 and the stage device 2. 20 and an oxidizer 30 which will be described in detail later.

  The stage apparatus 2 includes a stage 3 on which a substrate W is placed, an X-axis drive stage 4 that supports the stage 3 so as to be movable in the X-axis direction, and a Y that supports the stage 3 so as to be movable in the Y-axis direction. And an axis drive stage 5. These XY axis drive stages 4 and 5 can move the position of the substrate W freely in the XY axis directions.

  The drawing unit 10 includes an inkjet head 11, an ink tank 12, and a position detection mechanism 13. The ink tank 12 stores a liquid L containing a pattern forming material, and supplies the liquid L to the inkjet head 11. The inkjet head 11 is located above the stage 3 and has a discharge nozzle that discharges the liquid L onto the substrate, and is configured to apply the liquid L to a target position on the workpiece. The position detection mechanism 13 is configured to detect the landing position of the liquid L ejected from the inkjet head 11.

  The control device 20 includes a drawing control unit 21 and a discharge control unit 22. The drawing control unit 21 controls the landing position of the liquid L by moving the stage device 2 based on the information from the position detection mechanism 13 and the design data of the electronic circuit to be drawn, and supplies the liquid L to the discharge control unit 22. The discharge command is issued. The discharge controller 22 discharges the liquid L from the inkjet head 11 based on the discharge command from the drawing controller 21.

  As described above, the electronic circuit manufacturing apparatus controls the landing position of the liquid L to be applied onto the substrate by the control device 20, so that a line-shaped conductive film or an arbitrary-shaped conductive film is formed based on the design data. An electronic circuit is formed by drawing on the substrate.

[Liquid composition]
Next, the liquid L for drawing the electronic circuit will be described in detail. FIG. 2 is a diagram schematically showing the electronic circuit board W on which the electronic circuit 40 is formed. The electronic circuit 40 includes first and second electrodes 41a and 41b and a resistor 42 as electronic components, and the electronic component composed of the electrodes 41a and 41b and the resistor 42 is connected by a conductor 43. An electronic circuit is formed on the insulating layer 44.

  The liquid L has a conductive material as a pattern forming material, and specifically has metal particles containing silver (Ag) or copper (Cu). In addition, these Ag or Cu does not necessarily need to be a single metal particle, and a material containing a metal other than Ag and Cu, such as Ag—Pd and Ag—Cu, may be used as the metal particle.

  In addition, the liquid L can be selected as either a water-based or oil-based solvent as long as the metal particles can be dispersed. However, the liquid L has an organic substance that covers the surface of the metal particles so as to disperse the metal particles in the solvent. Yes.

  Furthermore, the metal as the conductive material is in the form of particles in order to increase the surface area as much as possible. And the particle size is 1 nm or more which exists as a particle | grain at least, and it is preferable that it is 100 nm or less from which the ratio of a surface atom becomes 0.1% or more among the total number of atoms which form particle | grains.

Further, the relationship of Equation 1 is established between the particle size of the metal particles and the melting point _{Tmf of the} metal particles. Therefore, it is more preferable that the particle size of the metal particles is selected between 1 nm and 30 nm in consideration of the relationship with the melting point T _mf of the metal particles. That is, it is preferable that the particle size of the metal particles is set so that the melting point _Tmf of the metal particles is higher than the firing temperature when firing the electronic circuit.

Ｔ_ｍｆ：金属粒子の融点、σ_ｓ：金属粒子を構成する金属固相の表面張力、σ_ｌ：金属粒子を構成する金属固相の表面張力、ｒ：粒子半径、Ｌ_０：金属の融解潜熱、Ｔ_０：金属の融点

T _mf : melting point of metal particle, σ _s : surface tension of solid phase of metal constituting metal particle, σ _l : surface tension of solid phase of metal constituting metal particle, r: particle radius, L ₀ : latent heat of fusion of metal , T ₀ : melting point of metal

  In addition, when the liquid L is applied on a substrate using an inkjet method, the liquid L needs to be a low-viscosity liquid in order to eject the liquid from a fine nozzle hole, and is generally 1 to 20 mPa · s. A liquid adjusted to a viscosity is used. The diameter of the nozzle hole of the inkjet head 11 is 5 μm to 50 μm, and the primary particle size of the metal particles is preferably 0.2 μm or less in order to discharge stably. Furthermore, it is preferable that the surface tension, the viscosity coefficient, etc. of this liquid L are adjusted according to the coating method.

[Configuration of Oxidizer]
Next, the oxidation apparatus 30 (see FIG. 1) that oxidizes the metal particles of the liquid L applied on the substrate will be described in detail. The electronic circuit manufacturing apparatus 1 is formed with the resistor 42 having a higher electrical resistance than the conductor 43 by oxidizing the metal particles of the conductor 43, and has an oxidizer 30 as a portion for oxidizing the metal particles. ing.

  The oxidation device 30 only needs to oxidize metal particles (resistance precursor) applied to the portion where the resistor 42 is formed. For example, an ultraviolet irradiation treatment device, a heat treatment device, an oxidation device using an oxidizing agent, ozone It consists of a processing device.

  Examples of the oxidizing agent include hydrogen peroxide solution, chlorate, bromate, iodate, etc. Any method can be used as long as the metal particles (Ag or Cu in this embodiment) can be oxidized. Any oxidizing agent may be used.

[Electronic circuit manufacturing method]
[First Electronic Circuit Manufacturing Method]
Next, a method for manufacturing an electronic circuit will be described in detail with reference to FIGS. First, as shown in FIG. 3A, when the electronic circuit 40 is formed on the substrate W, the insulating layer 44 is formed on the surface of the substrate W on which the electronic circuit 40 is formed. Then, electronic components (for example, the electrodes 41a and 41b) formed without using the liquid L are formed on the insulating layer.

  When an electronic component formed without using the liquid L is disposed, an electronic circuit is drawn by the liquid L using the inkjet head 11 as shown in FIG. Specifically, the liquid L is applied to the portion on the substrate where the conductor 43 is formed, and the liquid L is applied to the portion that becomes the resistor 42 (step S2 in FIG. 4). The liquid L applied on these substrates is gradually dried and solidified over time to become a conductor 43 and a resistance precursor 42a which is a previous stage of the resistor 42.

  When the liquid L applied on the substrate is dried, the conductor 43 is masked with a protective film (mask) 45, leaving the resistance precursor 42a, as shown in FIG. And only the metal particle of the part used as the resistor 42 is selectively oxidized with the oxidation apparatus 30, and the resistor 42 is formed (step S3 of FIG. 4). Thereby, the conductor 43 and the resistor 42 are formed on the substrate.

  Next, when the resistor 42 is formed, as shown in FIG. 3D, the mask covering the conductor 43 is removed (step S4 in FIG. 4), and the conductor 43 and the resistor 42 are fired. To do. When the substrate W is baked, the surfaces of the metal particles are fused and conducted, and organic substances covering the surfaces of the metal particles are removed. Thereby, an electronic circuit is formed on the substrate (step S5 in FIG. 4).

  In the present invention, since the surface of the metal particles is oxidized to control the conductivity, the firing temperature is set at least below the melting point of the formed metal. More specifically, the firing temperature is set to a temperature at which the metal oxide on the surface of the metal particles is not reduced to metal. For example, when the metal material is silver, the firing temperature is 250 ° C. or lower, more preferably 200 ° C. or lower. Set to In the case where the metal material is copper, when the firing atmosphere is in the air, it is combined with oxygen in the air and forms an oxide. Therefore, the firing is preferably performed at least in a nitrogen atmosphere, preferably in a vacuum.

  Further, the firing step may be performed before the resistance precursor oxidation step.

[Example 1]
Next, an electronic circuit 40 formed by using silver particle-containing ink (NPS-J, manufactured by Harima Chemical Co., Ltd.) as the liquid L is formed, and the change in electrical resistance when a part of the conductor 43 is oxidized is examined. Example 1 will be described.

  First, an Au film having a thickness of 0.1 μm and a 1 cm square is formed on the substrate as electrodes 41a and 41b by sputtering, and is formed at two places with an interval of 2 cm, and a conductor having a linear pattern is formed between these electrodes. (Electronic circuit) was formed (see FIG. 3B). More specifically, the above silver particle-containing ink is applied 300 times between the electrodes under the conditions of landing accuracy within ± 5 μm, discharge amount 25 pl, 100 μm pitch, and baked at 140 degrees for 1 hour. An electronic circuit having a straight line pattern with a thickness of 0.5 μm was obtained.

  The electrical resistance of the electronic circuit 40 was measured using a FP-μ2100 flying prober manufactured by Miyachi Systems Co., Ltd. and found to be 53.3Ω.

  Next, a parylene film having a film thickness of 1.6 μm was formed as a protective film on the electronic circuit board W by the LABCOTER PDS2010 type manufactured by Parylene Japan (see FIG. 3C). At this time, a part of the conductor (electronic circuit) and the electrode part were masked so that no parelin film was formed.

  Then, when UV light having a wavelength of 185 nm and 254 nm by a low-pressure mercury lamp is irradiated for 30 minutes to oxidize a part of the conductor to form silver oxide, the electric resistance of the electronic circuit 40 is 666.7Ω, and the resistance value due to oxidation is An increase was confirmed.

  Next, ethylene glycol was heated to 140 ° C. as a reducing agent, and when this substrate was immersed for 10 minutes, the electrical resistance value was measured again. As a result, it was 328.6Ω. Further, when immersed in ethylene glycol at 140 ° C. for 10 minutes, the resistance value becomes 109.4Ω, and then when immersed in ethylene glycol at 140 ° C. for another 10 minutes, the resistance value becomes 60.8Ω, almost the level before oxidation. I'm back.

  As described above, an electronic circuit including a resistor was produced from one type of ink by forming a wiring using a liquid containing metal particles and oxidizing a part thereof. Furthermore, the electronic circuit 40 having an arbitrary resistance value can be manufactured by changing the oxidation time or reducing the oxidized resistor portion.

[Example 2]
Next, Example 2 in which an electronic circuit 40 is formed using a copper particle-containing ink (manufactured by ULVAC, Inc., Cu1T) as the liquid L, and changes in the electrical resistance of the electronic circuit 40 are examined will be described. The drawing conditions in this example were the same as those in Example 1, and an electronic circuit having a straight line pattern of 300 μm width and 0.7 μm film thickness connecting electrodes 41a and 41b was formed.

In the baking, the substrate W was placed in a vacuum hot plate and baked at an atmospheric pressure of 10 Torr and 300 degrees for 30 minutes. In this state, N ₂ + 4% H ₂ gas was introduced and held for 30 minutes, and then the atmospheric pressure was set to 30 Torr and N ₂ + 4% H ₂ gas was introduced and held for 30 minutes.

  The electric resistance of the conductor (electronic circuit) thus obtained was measured and found to be 3.62Ω.

  Next, a parylene film was formed on the electronic circuit board in the same pattern as in Example 1. The film thickness is 1.6 μm. Thereafter, the electronic circuit board was heated to 200 ° C. in the atmosphere and held for 1 hour. At this time, the portion 17 where the parylene film is not formed in the conductive film is oxidized to become copper oxide, but the portion where the parylene film is formed does not come into contact with air, so that no oxidation reaction occurs.

  In the wiring obtained in this way, the resistor 42 is formed so as to be sandwiched between the conductors 43. When the electric resistance value of the conductive wiring in which a part of the conductor 43 was oxidized to form the resistor 42 was measured, it was 285 KΩ, and it was confirmed that the resistance value increased due to oxidation.

  As described above, an electric wiring including a resistor was formed from one type of ink by forming a wiring using ink containing metal particles and oxidizing a part thereof.

  As described above, the conductor 43 is formed by applying the liquid L containing metal particles on the substrate, and the resistor 42 can also be formed using the liquid L by oxidizing the metal particles. . Thereby, an electronic circuit can be formed with a small amount of material, and the electronic circuit 40 can be formed efficiently at low cost.

  In addition, a metal such as silver or copper is used as the pattern forming material, and the surface of the metal particles can be easily oxidized by increasing the surface area by making the metal into particles.

  In particular, the conductor 43 and the resistor 42 formed on the substrate have a particle size of 100 nm or less, and the ratio of surface atoms out of the total number of atoms forming the particles is 0.1% or more. Thus, the conductivity can be easily controlled. That is, since the particle size of the metal particles is small, the surface area of the metal particles is large, and the conductivity can be easily manipulated by forming a metal oxide on the surface of the metal particles.

  Furthermore, since the firing temperature is set to at least the melting point of the metal used as the pattern forming material, it is possible to suppress the reduction of the oxidized metal particles as much as possible. In addition, since the particle growth of the metal particles does not proceed sufficiently in the firing step, the particle shapes of the conductor 43 and the resistor 42 can be left. Therefore, even when the resistance precursor 42a is oxidized after the liquid applied on the substrate is baked as in the first and second embodiments, the conductivity can be easily manipulated.

[Method for Manufacturing Second Electronic Circuit]
Next, a second electronic circuit manufacturing method, which is different from the first electronic circuit manufacturing method, in the method of forming the resistor 42 will be described with reference to the flowchart of FIG.

  First, in forming the electronic circuit 40, as in the first electronic circuit manufacturing method, the insulating layer 44 is formed on the substrate, and the electronic component is formed on the insulating layer 44 without using the liquid L. (Step S1 in FIG. 5).

  Next, the liquid L is applied by the inkjet head 11 only to the portion where the resistor 42 is formed in the electronic circuit 40 to form the resistor precursor 42a (step S2 in FIG. 5). Then, the resistance precursor 42a is oxidized by the oxidizer 30 to form the resistor 42 (step S3 in FIG. 5).

  When the resistor 42 is formed, the inkjet head 11 applies the liquid L between the electronic components (for example, between the electrodes 41a and 41b and the resistor 42) to form the conductor 43 (step S4 in FIG. 5). .

  When the resistor 42 and the conductor 43 are formed on the substrate, the resistor 42 and the conductor 43 are baked in the same manner as in the first electronic circuit manufacturing method to form an electronic circuit (step S5 in FIG. 5). .

  In this way, after applying the liquid L on the substrate in advance only at the portion where the resistor 42 is to be formed and oxidizing all the formed conductor (resistance precursor), the conductor 43 may be wired between the electronic components. The electronic circuit 40 can be formed on the substrate.

[Third electronic circuit manufacturing method]
Next, a third electronic circuit manufacturing method, which is different from the first and second electronic circuit manufacturing methods, is described based on the flowchart of FIG.

  First, in forming the electronic circuit 40, the insulating layer 44 is formed on the substrate, and the electrons formed on the insulating layer 44 without using the liquid L, as in the first electronic circuit manufacturing method. Parts are arranged (step S1 in FIG. 6).

  When the electronic component formed without using the liquid L is arranged, the electronic circuit is drawn by the inkjet head 11 as in the first method for manufacturing the electronic circuit (step S2 in FIG. 6). Specifically, the liquid L is applied to a portion on the substrate where the conductor 43 is formed and a portion to be the resistor 42.

  Next, the oxidation device 30 oxidizes the metal particles in the portions that become the conductor 43 and the resistor 42 to form the resistor 42 (step S3 in FIG. 6).

  When the resistor 42 is formed, the resistor 42 is masked to selectively reduce the oxidized metal particles of the conductor 43 (step S4 in FIG. 6).

  When the conductor 43 is reduced, the mask covering the resistor 42 is removed (step S5 in FIG. 6), and the conductor 43 and the resistor 42 are baked to form an electronic circuit on the substrate (FIG. 6). Step S6).

  In this way, the portion where the resistance precursor to be the resistor 42 is formed is covered and sealed with a protective film or the like, and the electronic circuit 40 is formed even if the oxide is reduced using a reducing agent only at the portion where the conductor 43 is formed. can do.

  In the present embodiment, the manufacturing method of the first to third electronic circuits has been described. However, the conductor 43 is formed of metal particles, and the resistor 42 is formed by oxidizing a part of the metal particles of the conductor 43. The electronic circuit may be formed by any method as long as it is formed.

  In addition to the metal particles, a material in which a metal material is dissolved in the solution can be used as the material of the liquid L containing the conductive material. In addition to copper and silver, metal particles such as aluminum can be used as the liquid. You may use as a metal particle contained.

  Further, electronic components that are not formed using the liquid L such as the electrodes 41a and 41b described above may be disposed on the substrate after the conductor 43 and the resistor 42 are formed. Further, the liquid L can form the above-described various electronic components other than conductors and resistors.

  Furthermore, since the electrical conductivity of the conductive film of the present invention can be controlled by controlling the oxidation state of the metal particle surface, the electrical conductivity in the resistor has a distribution by providing the distribution in the oxidation state in the resistor. You can also. Further, the oxidation device 30 for oxidizing the metal particles may be provided integrally with the inkjet device 1 or may be provided separately.

  Moreover, you may perform the said baking process before an oxidation process. Further, the organic substance of the liquid L may be removed by a chemical reaction other than a method of performing a heat treatment such as baking, dissociating the bond between the metal particles and the organic substance, and volatilizing and removing the organic substance.

  In addition to the inkjet method, the electronic circuit formation method described above may be performed by a dispenser method, a screen printing method, an offset printing method, or the like. Can be applied.

  Furthermore, although one inkjet head 11 that applies the liquid L is described, as long as the inkjet head 11 applies the same liquid L, a plurality of inkjet heads 11 may be used to increase the speed. In addition, a plurality of discharge nozzles may be provided in one inkjet head 11. Further, as a discharge method of the ink jet head 11, there is a piezo method in which a liquid material is discharged by a change in volume of a piezoelectric element, or a thermal method in which a liquid material is discharged by suddenly generating bubbles by applying heat. Various methods may be used.

  In addition to silicon substrates, electronic circuit boards can have any required strength, such as paper phenol, paper epoxy, glass, glass epoxy, Teflon (registered trademark), alumina, ceramic substrates, polyimide and polyester films. Such a thing may be used. Furthermore, an electrode, a functional element, or the like can be formed on the substrate W as necessary. For the electrode, Au, Pt, Ag, Al, Cu, Ti, Cr, or the like may be used, and two or more metal materials may be used in order to improve the adhesion to the substrate W.

  The insulating layer 44 may be formed using any method such as a method of forming an oxide film by a sputtering method, a CVD method, a thermal oxidation method, or the like. The material of the insulating layer 44 is made of silicon oxide, silicon nitride, silicon carbide, SiNC, SiOC, epoxy resin, alumina, polyimide resin, polyamide resin, polyamideimide resin, polyurea resin, silicon ladder polymer, or polyparaxylene. Is preferred. Further, the insulating layer 44 is not necessarily provided on the substrate.

  Further, any type of protective film may be used as the protective film as a mask. Furthermore, although the reducing agent mentioned above may be glycol and alcohol, it is preferable to use ethylene glycol, diethylene glycol or propylene glycol used in this example.

11: inkjet head, 40: electronic circuit, 41a, 41b, 42: electronic component, 42: resistor, 43: conductor, 45: mask (protective film), L: liquid, W: substrate

Claims (8)

In the method of manufacturing an electronic circuit having a resistor having a higher electrical resistance than the conductor as the electronic component, forming a circuit by connecting the electronic component with a conductor,
The conductor is formed by applying a liquid containing metal particles on a substrate,
The resistor is formed by applying the liquid on a substrate and oxidizing the metal particles contained in the liquid.
A method for manufacturing an electronic circuit. The liquid contains at least copper or silver as the metal particles, and includes an organic substance covering the surface of the metal particles.
The method for manufacturing an electronic circuit according to claim 1. The metal particles have a particle size of 100 nm or less.
The manufacturing method of the electronic circuit of Claim 1 or 2. Firing the conductor and the resistor at a temperature equal to or lower than the melting point of the metal constituting the metal particles;
The method for manufacturing an electronic circuit according to claim 1. Applying the liquid on a substrate by an inkjet head to form the conductor, and applying the liquid to a portion that becomes the resistor;
Masking the conductor and selectively oxidizing the metal particles of the portion to be the resistor to form the resistor;
Removing a mask covering the conductor, and
The manufacturing method of the electronic circuit of any one of Claims 1 thru | or 4. Applying the liquid to the portion of the circuit where the resistor is formed by an inkjet head;
Oxidizing the coated liquid metal particles to form the resistor; and
Applying the liquid between the electronic components by the ink-jet head and forming the conductor,
The manufacturing method of the electronic circuit of any one of Claims 1 thru | or 4. Applying the liquid on a substrate by an inkjet head to form the conductor, and applying the liquid to a portion that becomes the resistor;
A step of oxidizing the metal particles of the conductor and the resistor to form the resistor;
Masking the resistor and selectively reducing oxidized metal particles of the conductor;
Removing the mask covering the resistor,
The manufacturing method of the electronic circuit of any one of Claims 1 thru | or 4. In an electronic circuit board on which an electronic circuit having a resistor having a higher electrical resistance than the conductor is formed as an electronic component connected by a conductor,
The conductor is formed by solidifying a liquid containing metal particles on a substrate,
The resistor is formed by oxidizing metal particles of the conductor,
An electronic circuit board characterized by that.

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