JP2016207905A - Electronic device manufacturing method, electronic device, circuit board manufacturing method, and circuit board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a circuit board which has high reliability of conductivity of a circuit pattern and is capable of electrifying a large current while the circuit board is curved.SOLUTION: The manufacturing method includes: a first step for coating a board surface with a solution in which conductive nano-size particles with a particle diameter being smaller than 1 μm and an insulation material are dispersed, or a solution in which conductive nano-size particles each coated with an insulation material layer are dispersed, in a desired shape and forming a film including the conductive nano-size particles each coated with the insulation material; and a second step for irradiating the formed film with light in a predetermined pattern, sintering the conductive nano-size particles with the light and forming a first circuit pattern that is a conductive nano-size particle layer of a predetermined pattern. A step for curving the board is implemented before the first step, or after the first step and before the second step.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an electronic device manufacturing method using a circuit board having a through hole.

  As a method of manufacturing a circuit board having a through hole, a method of forming a conductive through hole by forming a circuit pattern on a substrate, then opening a through hole in the circuit board, and filling the through hole with a conductive material Is used.

  In recent years, a technical field called printed electronics for forming circuit patterns by printing has been actively studied. For example, in Patent Document 1, a non-conductive film containing copper nanoparticles is deposited by an inkjet printer or the like, and the formed film is irradiated with light from above to fuse the copper particles to form a conductive circuit. Techniques to do this are disclosed.

JP, 2014-116315, A

  Since the conductive through hole formed by the above-described conventional method is made of a member different from the circuit pattern and the conductive material in the through hole, the strength of the joint portion is weak, and disconnection occurs due to stress or heat. Sometimes.

  The objective of this invention is providing the manufacturing method of the electronic device which can form the circuit material of a circuit board, and the electrically-conductive material in a through hole with the same member.

  In order to achieve the above object, the present invention provides a solution in which conductive nano-sized particles having a particle size of less than 1 μm, conductive micro-sized particles having a particle size of 1 μm or more, and an insulating material are dispersed, Alternatively, a solution in which conductive nano-sized particles and conductive micro-sized particles respectively coated with an insulating material layer are dispersed is applied to the surface of the substrate in a desired shape. Thereby, a film containing conductive nano-sized particles and conductive micro-sized particles coated with an insulating material is formed. On the other hand, light is irradiated to a predetermined position from the surface opposite to the film of the substrate, and a through hole is formed in the substrate by the light. As the through hole is formed in the substrate, a part of the coating film having fluidity flows into the through hole and fills the through hole. By irradiating the coating film that has flowed into the through hole with light, the conductive nano-sized particles and the conductive micro-sized particles of the film in the through hole are sintered to form a conductor, and the conductor in the through hole is formed. Fill with.

  According to the present invention, since the circuit pattern of the circuit board and the conductive material in the through hole can be formed from the same member, disconnection is hardly generated at the junction between the conductive portion in the through hole and the circuit pattern.

(A)-(g) Explanatory drawing which shows the manufacturing method of the through hole 70 and the conductor 52 of 1st Embodiment. (A)-(f) Explanatory drawing which shows another manufacturing method of the through-hole 70 and the conductor 52 of 1st Embodiment. (A)-(d) Explanatory drawing which shows another manufacturing method of the through hole 70 and the conductor 52 of 1st Embodiment. (A)-(e) Explanatory drawing which shows another manufacturing method of the through hole 70 and the conductor 52 of 1st Embodiment. (A) Top view of electronic device of 2nd Embodiment, (b) AA sectional drawing, (c) BB sectional drawing. (A)-(g) Explanatory drawing which shows the manufacturing process of the electronic device of 2nd Embodiment. (A)-(f) Explanatory drawing which shows the manufacturing process of the electronic device of 2nd Embodiment. The top view of the state which removed the (a) board | substrate 10-2 of the electronic device of 3rd Embodiment, (b) AA sectional drawing, (c) BB sectional drawing.

  An electronic device manufacturing method according to an embodiment of the present invention will be described.

<First Embodiment>
First, a substrate 10 is prepared as shown in FIG.

  Next, as shown in FIG. 1B, conductive nano-sized particles (hereinafter referred to as conductive nanoparticles) having a particle size (for example, average particle size) of less than 1 μm, and particle sizes (for example, average particles) Conductive nano-size particles (hereinafter referred to as conductive micro-particles) having a diameter (diameter) of 1 μm or more and conductive nanoparticles at least coated with a solution in which an insulating material is dispersed in a solvent or an insulating material layer And a solution in which conductive microparticles are at least dispersed in a solvent. As the solvent, an organic solvent or water can be used. This solution is applied to the surface of the substrate 10 in a desired shape. The applied solution has a smooth surface on the substrate 10 to form a coating film (film 51). In the film 51, conductive nanoparticles and conductive microparticles are dispersed, and the periphery of the conductive nanoparticles and the conductive microparticles is covered with an insulating material. Therefore, the film 51 is non-conductive at this stage.

  Here, the coating film 51 is held on the substrate in a liquid state in which the viscosity is adjusted so as to be able to flow into the through hole in FIG. The viscosity is appropriately selected depending on the size of the through hole. For example, the type and concentration of the solvent to be used, the type of additive such as an insulating material, and the type of additive such as a viscosity modifier are adjusted.

  Next, as shown in FIG. 1C, a predetermined position is irradiated with light from the surface opposite to the film 51 of the substrate 10, and a through hole (through hole) 70 is formed in the substrate 10 by the light 101. As a result, the film 51 is dropped into the through hole 70 to fill the through hole 70 (FIG. 1D). The light 101 is weakened when the through hole 70 is formed. When the conductive nanoparticles are melted at a temperature lower than the melting point of the bulk of the material constituting the particles by the irradiation of the light 101, the insulating material layer around the conductive nanoparticles is evaporated by the irradiation of the light 101. Or soften. Since the molten conductive nanoparticles are bonded to the surrounding conductive microparticles, the conductive microparticles can be sintered at a lower temperature than the bulk by light irradiation starting from the conductive nanoparticles. Therefore, by irradiating the light 101, the conductive nanoparticles and the conductive microparticles of the film 51 in the through hole are sintered to form the conductor 52, and the inside of the through hole 70 is filled with the conductor 52. it can.

  Moreover, leakage of the coating film 51 from the through hole 70 can be prevented by adjusting the viscosity of the coating film 51 and managing the irradiation time of the light 101 to be sintered.

  Irradiation conditions (time and output) of the light 101 are set in consideration of drying or evaporating a viscosity-adjusted solvent or additive (viscosity adjusting material or the like) during firing.

  It is also possible to color the substrate 10 at the position where the through hole 70 is formed in advance to a color that absorbs the light 101. Thereby, the through hole 70 can be formed easily.

  Further, as shown in FIGS. 1C and 1D, a predetermined region of the film 51 around the through hole 70 is irradiated with light 102 to sinter the conductive nanoparticles and the conductive microparticles. Then, a circuit pattern 50 continuous with the conductor 52 in the through hole 70 is formed. In addition, although the electroconductive nanoparticle after light irradiation has couple | bonded particles, the particle shape is maintained to some extent.

  The conductor 52 and the circuit pattern 50 in the through hole 70 formed in such a process are continuous and become one member. Therefore, the strength of the joint portion between the conductor 52 and the circuit pattern 50 is strong, and it is difficult to break even when subjected to stress or heat.

  Subsequently, as shown in FIG. 1E, a coating film 51 is formed on the back surface of the substrate 10, and the light 102 is irradiated as shown in FIG. A circuit pattern in which the front and back circuit patterns 50 are connected can be formed through the through hole 70 filled with the body 52.

  Here, after the through hole 70 and the conductor 52 are formed, the peripheral circuit pattern 50 is formed. However, the present invention is not limited to this procedure. For example, in order to form the circuit pattern 50 in FIG. 1C, the light 102 reaches the region where the through hole 70 is to be formed while performing the sintering by moving the light 102 along a predetermined pattern. For example, if the light intensity is increased and irradiated as the light 101 and the through hole 70 is formed, the light intensity is immediately decreased to form the conductor 52 as the light 102, and then the light 102 is again formed into a predetermined pattern. It is also possible to make it a procedure to move along.

  Further, as in the steps of FIGS. 2A to 2F, the film 51a is laminated only by dropping the solution as shown in FIGS. 2C and 2D only in the region where the through hole 70 is to be formed. It is also possible to keep it. 2E and 2F, even when the light 101 is irradiated to form the through hole 70 and the inside thereof is filled with the conductor 52, the upper surface of the film 51 is directly above the through hole 70. It will flatten out without being depressed.

  Further, in order to prevent the film 51 from being baked before the softened film 51 is filled with the heat generated by the irradiation of the light 101 that forms the through hole 70, FIGS. 3A to 3D are used. The heat transfer member 80 can be disposed so as to contact the film 51 before irradiating the light 101 for forming the through hole 70 as in the process of FIG. For example, as shown in FIG. 3C-1, the heat transfer member 80 is mounted so as to be in contact with the film 51 on the region where the through hole 70 is formed. Thereby, the heat generated in the film 51 on the through hole formation region can be conducted to the heat transfer member 80, and the firing of the film 51 on the formation region of the through hole 70 can be suppressed. As the heat transfer member 80, a member made of a material having a large heat capacity, for example, a member made of aluminum, copper, iron, or the like can be used. The size of the heat transfer member 80 is desirably set to cover at least the through-hole formation region. The heat transfer member 80 is removed after the inside of the through hole 70 is filled with the softened film 51 as shown in FIG. That is, the irradiation of the light 102 for sintering the film 51 in a predetermined region around the through hole 70 is performed with the heat transfer member 80 removed as shown in FIG.

  The heat transfer member 80 is preferably a surface-treated member so as not to be bonded to the film 51.

  Further, without using the heat transfer member 80, it is also possible to prevent the film 51 from being fired before the film 51 softened in the through hole 70 by applying cold air to the film 51 to lower the temperature. It is.

  Furthermore, as shown in FIGS. 4A to 4E, the coating film 51 that has flowed into the through hole 70 from the upper surface side of the substrate 10 may not fill the entire through hole 70 (FIG. 4 ( In this case, after the coating film 51 formed on the surface side of the substrate 10 as shown in Fig. 4 (c-3) is sintered to form the conductor 52, in Fig. 4 (c-4) Then, a part of the coating film 51 formed from the back side of the substrate 10 is caused to flow into the space remaining in the through hole 70 and further irradiated with light 101 and 102 to be sintered (FIG. 4D). A circuit pattern in which the front and back circuit patterns 50 are connected can be formed through the through hole 70 filled with the conductor 52.

  Note that the region of the film 51 that is not irradiated with light remains non-conductive because sintering does not occur. The nonconductive film 51 may be removed in a subsequent process. For example, the film 51 can be removed using an organic solvent or the like.

  Any material may be used for the substrate 10 as long as it can support the first circuit pattern 40, has at least a surface insulating property, and can withstand light irradiation when forming the circuit pattern 50. It may be a material. It is further desirable if the substrate 10 is a material that can be bent. For example, a polyethylene terephthalate (PET) substrate, a polyethylene naphthalate (PEN) substrate, a glass epoxy substrate, a paper phenol substrate, a flexible printed substrate, a ceramic substrate, a glass substrate, a metal substrate whose surface is covered with an insulating layer, and the like can be used. .

  As the substrate 10, either a light transmissive substrate or a non-light transmissive substrate can be used.

  When the light-transmitting substrate 10 is used, light for firing the circuit pattern 50 can be irradiated from the back side of the substrate 10 as shown in FIGS. In the case of the light-transmitting substrate 10, the transmittance is preferably 50% or more and 95% or less, and more preferably 70% or more and 90% or less, from the viewpoint of forming the through hole 70 and firing with the light transmitted through the substrate. It is preferable that

  When a non-light-transmissive substrate is used, light 102 for firing the circuit pattern 50 can be irradiated from the surface side of the substrate 10 as shown in FIG.

  Further, the substrate 10 of the present embodiment can be a film-like substrate.

  As a material of the conductive nanoparticles constituting the circuit pattern 50, one or more of conductive metals and conductive metal oxides such as Ag, Cu, Au, Pd, ITO, Pt, and Fe can be used. .

Insulating materials for coating the conductive nanoparticles include organic materials such as styrene resin, epoxy resin, silicone resin, and acrylic resin, inorganic materials such as SiO ₂ , Al ₂ O ₃ , and TiO _2, and organic and inorganic materials. One or more of these hybrid materials can be used. In addition, the thickness of the insulating material layer covering the conductive nanoparticles and the conductive microparticles in the film 51 is preferably about 1 nm to 10000 nm.

The conductor 52 and the circuit pattern 50 include, for example, conductive particles having a particle size (for example, an average particle size) of 1 μm to 100 μm. The wiring width of the circuit pattern 50 can be 10 μm or more, and can be formed to about 100 μm, for example. The thickness of the circuit pattern 50 can be formed to about 1 μm to 100 μm, for example, about 20 μm. The electrical resistance value of the second circuit pattern 50 is preferably 10 ⁻⁴ Ω / cm ² or less, and particularly preferably a low resistance of the order of 10 ⁻⁶ Ω / cm ² or less.

  The wavelength of the light irradiated in the steps of FIG. 1C, FIG. 2E, etc. may be ultraviolet, visible, or infrared light, but is absorbed by the conductive nanoparticles contained in the film 51. Select the wavelength to be used. When Ag, Cu, Au, Pd, or the like is used as the conductive nanoparticles, visible light of 400 to 600 nm can be used, for example. Desired patterns for irradiating light (through hole 70 and circuit pattern 50) can be formed by passing light through a mask having an opening. Alternatively, a light beam condensed to an irradiation diameter smaller than the size of the through hole 70 and the wiring width of the circuit pattern 50 may be used to scan the light beam in a desired pattern on the film 51.

  In this embodiment, the film 51 is formed by sintering conductive nanoparticles and conductive microparticles. However, the present invention is not limited to this, and a conductive material having a particle size (for example, an average particle size) of 1 μm or less. It is also possible to form the conductive body 52 and the circuit pattern 50 in the through hole 70 by sintering the conductive nanoparticles. The details of each process other than the particle size are the same as those described above. Thereby, a thin circuit pattern can be formed.

<Second Embodiment>
In the second embodiment, electronic components are mounted on a circuit board having a through hole 70 and a circuit pattern 50 formed by the same method as in the first embodiment, as shown in FIGS. A method for manufacturing an electronic device will be described.

  The electronic device of FIG. 5 includes a substrate 10 provided with a circuit pattern 50 (50a, 50b) (also referred to as a second circuit pattern 50), an electronic component 30, and a resistor 240. A part 50 a of the circuit pattern 50 is mounted on one surface of the substrate 10, and the other portion 50 b is mounted on the other surface of the substrate 10. The second circuit pattern 50 a on one surface and the second circuit pattern 50 b on the other surface are connected in the thickness direction of the substrate 10 by the conductor 52 in the through hole 70.

  In addition, a region 20 for mounting the electronic component 30 is provided on the substrate 10, and a first circuit pattern 40 that is electrically connected to the electronic component 30 is disposed in the region 20. The second circuit pattern 50 is connected to the first circuit pattern 40 at the periphery of the region 20. The second circuit pattern 50 supplies current to the first circuit pattern 40 from the power source 60 disposed outside the region 20.

  The conductor 52 and the second circuit pattern 50 in the through hole 70 are formed of a layer containing conductive nanoparticles and conductive microparticles, as in the first embodiment. On the other hand, a part or all of the first circuit pattern 40 is constituted by a layer containing conductive nanoparticles having a particle size of less than 1 μm.

  Specifically, as shown in FIGS. 5A and 5B, the second circuit pattern 50 is disposed on both sides of the region 20 for mounting the electronic component 30. The first circuit patterns 40 are arranged in at least one pair in the region 20 and are connected to the second circuit patterns 50 on both sides of the region 20, respectively. A non-conductive layer 41 is disposed between the pair of first circuit patterns 40. The electrode 31 of the electronic component 30 is directly fixed to the pair of first circuit patterns 30.

  The thickness of the second circuit pattern 50 is larger than the thickness of the first circuit pattern 40 as shown in FIG. In the present embodiment, the first circuit pattern 40 is formed only in the region 20 on which the electronic component 30 is mounted, which requires fine wiring, and the outside of the region 20 is configured by the thick second circuit pattern 50. Thus, a large current can be supplied to the electronic component 30.

In the first circuit pattern 40, the conductive nanoparticles include conductive particles having a particle size of 0.01 μm to 1 μm. The wiring width of the first circuit pattern 40 (sintered portion) can be set to 1 μm or more, for example. The first circuit pattern 40 can be formed to a thickness of about 10 nm to 10 μm. The electrical resistance value of the first circuit pattern 40 is preferably 10 ⁻⁴ Ω / cm ² or less, and particularly preferably a low resistance of the order of 10 ⁻⁶ Ω / cm ² or less.

  Since the particle size and wiring width of the conductive particles of the second circuit pattern 50 are the same as those of the circuit pattern 50 of the first embodiment, the description thereof is omitted.

  A manufacturing method will be described. First, the substrate 10 is prepared. Here, a transparent substrate is used as the substrate 10.

  Next, a solution in which conductive nanoparticles, conductive microparticles, and an insulating material are dispersed in a solvent, or conductive nanoparticles and conductive microparticles coated with a layer of an insulating material are dispersed in the solvent. 1 (a) and 1 (b) is applied to one surface of the substrate 10 to form a film 51, and FIGS. 1 (c) and 1 (d) described in the first embodiment. Through this process, the second circuit pattern 50a, the through hole 70, and the conductor 52 filling it are formed.

  The region of the film 51 that has not been irradiated with light remains non-conductive because sintering does not occur. Note that the region of the non-conductive film 51 that is not sintered may be left as it is, or may be removed as shown in FIG.

  The second circuit pattern 50a may be formed by forming the film 51 only on the region where the second circuit pattern 50a is to be formed using a printing method or the like and irradiating the entire film 51 with light. it can.

  Next, the film 51 is formed on the other surface of the substrate 10 by the steps of FIGS. 1A and 1B of the first embodiment, and the film 51 is irradiated with light to sinter the second circuit pattern 50b. Is formed on the other surface of the substrate 10. At this time, the second circuit pattern 50b is formed so as to cover the position of the through hole 70, whereby the second circuit pattern 50a on one surface and the second circuit pattern 50b on the other surface are electrically connected to each other in the through hole 70. They can be joined by the body 52.

  In the region where the resistor 240 is to be formed, a gap is provided in the middle of the second circuit pattern 50a.

  Next, a process of forming the first circuit pattern 40 and the resistor 240 on the substrate 10 will be described with reference to FIGS.

  Through the above-described steps, the substrate 10 in which the second circuit pattern 50 (50a, 50b), the through hole 70 and the conductor 52 are formed in the shape of FIGS. 5A and 5B is formed (FIG. 6A). ), FIG. 7 (a)). In order to form the first circuit pattern 40 and the resistor film 140 of the resistor 240, the conductive nanoparticle and the conductive material coated with a layer of the insulating material or a solution in which the insulating material is dispersed in a solvent. A solution in which nanoparticles are dispersed in a solvent is prepared. The same conductive nanoparticles and insulating material as in the first embodiment can be used.

  As shown in FIGS. 6B and 7B, the above solution is applied to the inside of the region 20 on the surface of the substrate 10 and the gap of the second circuit pattern 50 where the resistor 240 is to be formed. The applied solution has a smooth surface on the substrate 10 as shown in FIGS. 6C and 7C, and forms coating films (films 41 and 141), respectively. The ends of the films 41 and 141 are overlapped with the ends of the second circuit pattern 50, respectively. If necessary, the membranes 41 and 141 are heated and dried. Conductive nanoparticles are dispersed in the films 41 and 141, and the periphery of the conductive nanoparticles is covered with an insulating material.

  Subsequently, as shown in FIG. 6D, the electronic component 30 is mounted in alignment with a predetermined position of the film 41, and the electrode 31 of the electronic component 30 is in close contact with the film 41 as shown in FIG. 6E. Let

  Next, as shown in FIGS. 6 (f) and 7 (d), the films 41 and 141 are each irradiated with light in a desired pattern, and the conductive nanoparticles are sintered by the light. Thus, a pair of first circuit patterns 40 is formed in the region 20 as shown in FIG. 6G, and the resistor film 140 is formed in the gap where the resistor 240 is to be formed as shown in FIG. Form.

  The light irradiating the film 41 is irradiated from the back side of the substrate 10 as shown in FIG. 6F, while the light irradiating the film 141 is irradiated from the front side of the substrate 10 as shown in FIG. You may do and may irradiate from the back side.

  The wavelength of the light to be irradiated is a wavelength that is absorbed by the conductive nanoparticles contained in the films 41 and 141, and a wavelength that is less absorbed by the substrate 10 is selected and used. Irradiation light may be any of ultraviolet, visible, and infrared light. For example, when Ag, Cu, Au, Pd, or the like is used as the conductive nanoparticles, visible light of 400 to 600 nm can be used.

  The irradiation pattern of the light applied to the film 41 includes a region where the electrode 31 of the electronic component 30 of the film 41 is in contact. Since the position of the electrode 31 of the mounted electronic component 30 can be confirmed and the irradiation pattern can be determined using the electrode position as a reference, positional deviation between the circuit pattern and the electronic component can be suppressed. In order to form the first circuit pattern 40 that is continuous with the second circuit pattern 50, it is desirable to irradiate the light to the region overlapping the second circuit pattern 50. By light irradiation, the conductive nanoparticles are melted at a temperature lower than the melting point of the bulk of the material constituting the particles. The insulating material layer around the conductive nanoparticles is evaporated or softened by light irradiation. Therefore, the molten conductive nanoparticles are fused directly with the adjacent particles, or are fused with the adjacent particles through the softened insulating material layer. Thereby, electroconductive nanoparticles can be sintered and the area | region irradiated with light becomes the electroconductive 1st circuit pattern 40. FIG. In addition, although the electroconductive nanoparticle after light irradiation has couple | bonded particles, the particle shape is maintained to some extent. That is, a part of the particle shape of the conductive nanoparticles remains in the conductive nanosize particle layer.

  On the other hand, for the resistor film 140, the resistance value is measured by the process of FIG. 7E, and when the resistance value is larger than a predetermined range, the edge of the resistor film 140 is shown in FIG. Then, the resistor film 140 is spread, and the resistor film 140 is additionally formed. On the other hand, when the resistance value is smaller than the predetermined range, the resistor film 140 is trimmed and removed by irradiating light. As a result, the resistance value can be adjusted to fall within a predetermined range.

  Thereafter, the unsintered films 41 and 141 may be removed.

  Similarly, after the pair of first circuit patterns 40 are formed on the other surface of the substrate 10, the electronic component 30 is mounted and connected to the first circuit pattern 40.

  In the above description, the film 141 that forms the resistor 240 is formed of the same coating liquid as the film 41 that forms the first circuit pattern 40 at the same timing, but the film 141 that forms the resistor 240 is the second film. It is also possible to form the circuit pattern 50a and the conductor 52 with the same coating solution as the film 51 at the timing of forming the film 51. That is, conductive microparticles can be contained in the coating liquid that forms the film 141 that forms the resistor 240.

  In addition, in the coating solution for forming the film 141, the amount of conductive microparticles or the amount of the insulator material may be adjusted according to the target resistance value and the thickness of the resistor film. it can. When the conductive microparticles are included in the coating solution for forming the film 141, the resistor film 140 is formed in a state where a part of the particle shape of the conductive microparticles and the conductive nanoparticles remains.

  In addition, in the coating solution for forming the film 141 that forms the resistor 240, the insulating material dispersed together with the conductive nanoparticles and the conductive microparticles, or the insulating material covering the conductive nanoparticles and the conductive microparticles is Although it evaporates at the time of light irradiation to sinter conductive nanoparticles and conductive microparticles, it does not completely evaporate and may partially remain in the resistive film. Since a part of the insulating material remains in the resistance film, the resistance value is increased accordingly. That is, the resistance value is adjusted by adjusting the residual amount of the insulating material dispersed together with the conductive nanoparticles and conductive microparticles, or the insulating material covering the conductive nanoparticles and conductive microparticles in the resistive film. Can be adjusted.

  In addition, the coating liquid for forming the film 141 that forms the resistor 240 includes powder, particles composed of indium oxide, copper oxide, silver oxide, Cr, C, and the like together with conductive nanoparticles and conductive microparticles. Can be dispersed to adjust the resistance value. By dispersing these powders and particles, the resistor film 140 is in a state in which these powders and particles are interposed in the sintered conductive nanoparticles and conductive microparticles, and partially conductive nanoparticles and conductive microparticles. The resistance of the resistor film 140 is higher than that of particles that inhibit the particle sintering and do not disperse. These powders and particles can be nano-sized or micro-sized.

  Through the above steps, the second circuit pattern 50 shown in FIGS. 5A to 5C, the through hole 70 filled with the conductor 50, the fine first circuit pattern 40 having a desired pattern, and the resistor film 140 can be simultaneously formed by a simple process of coating and light irradiation. Since these are integrally connected by light sintering, they are not easily disconnected. In addition, the resistance value of the resistor film 140 can be increased or decreased by light irradiation, and a resistor having a desired resistance value can be easily formed. Therefore, a large current can be supplied from the low-resistance thick film second circuit pattern 50 to the electronic component 30 via the first circuit pattern 40, and an excessive current flows through the electronic component 30 by the resistor 240. Can be prevented.

  In addition, since the conductive nanoparticles are melted during the sintering, the conductive nanoparticles are also bonded to the electrode 31 of the electronic component 30 and the first circuit pattern 40 and the electrode 31 can be fixed. That is, the electrode 31 is directly bonded to the first circuit pattern 40 without using bumps or the like. Since this manufacturing method performs light irradiation with the electronic component 30 mounted, the light irradiation can be performed with a pattern based on the position of the electrode 31 after mounting. Therefore, the bonding between the electrode 31 of the electronic component 30 and the first circuit pattern 40 is reliably obtained with high accuracy.

  In order to increase the fixing strength of the first circuit pattern 40 and the electrode 31, it is preferable to irradiate light while heating the electronic component or to irradiate light while applying pressure.

  6B and 7B, the conductive nanoparticles and the insulating material dispersed in a solvent, or the conductive nanoparticles coated with a layer of the insulating material are used. When the solution dispersed in the solvent is applied onto the substrate 10, the films 41 and 141 may be formed using a printing method. As a printing method, inkjet printing, flexographic printing, gravure offset printing, screen printing, or the like can be used. In this case, in the process of FIG. 6D and FIG. 7D, the first circuit pattern 40 and the resistance film 140 are formed by irradiating and sintering the entire films 41 and 141 formed by printing. can do. The resistor film 140 is irradiated by adjusting the irradiation light intensity so that only a part in the thickness direction is sintered, and the resistance value is adjusted by spreading the resistor film 140 in the thickness direction. It can also be done. This method has an advantage that the nonconductive film 41 is not formed around the first circuit pattern 40 and the resistor film 140.

  When the substrate 10 is bent as shown in FIGS. 5B and 5C, the substrate 10 is bent before the first light irradiation step (FIGS. 1C and 2E). It is preferable. Thereby, disconnection and thinning of the second circuit pattern 40 can be prevented. In particular, when the bending process is performed after the sintering process, the resistance film 140 expands and contracts to change the resistance value of the resistance film, thereby reducing the role as a protection circuit. By implementing, a desired resistance value can be obtained.

  At this time, the film 41 including conductive nanoparticles may be formed before or after the bending process. When the substrate 10 is bent in a state where the film 41 is formed, cracks may occur in the film 41 itself, but the conductive nanoparticles melted by light irradiation fuse with adjacent particles, and in this fusion process Since the cracks in the film 41 disappear, the first circuit pattern 40 without cracks can be formed.

  In the second embodiment, light is irradiated from the back side of the film 41 using the light transmissive substrate 10. However, the film 41 and the film 141 are formed using the non-light transmissive substrate 10 as the substrate 10. It is also possible to irradiate light from the upper surface. In that case, after the film 41 is irradiated with light to form the first circuit pattern 40, bumps 42, solder balls or the like are mounted on the first circuit pattern 40 as necessary, and the electronic component 30 is The electrodes 31 are mounted so as to be aligned on the first circuit pattern 40. When bumps are arranged, the bumps are aligned so that the positions of the bumps coincide with the positions of the electrodes 31 of the electronic component 30. Thereafter, heating or ultrasonic waves are applied to connect the electrode 31 of the electronic component 30 to the first circuit pattern 40 and fix the electronic component 30.

  According to the present embodiment, while various electronic components are mounted on the substrate 10 with high density, an electronic device can be manufactured by collectively forming a circuit including a through hole and mounting the electronic component with a small number of manufacturing processes. Moreover, since the circuit pattern can be easily changed by light irradiation, it is possible to easily cope with a design change.

<Third Embodiment>
An electronic device manufacturing method according to the third embodiment will be described with reference to FIG.

  In the third embodiment, an electronic component 30 (30-a, 30-b) having an electrode 31 on both the upper surface and the lower surface is used. The electronic component 30-a is sandwiched between the two substrates 10-1 and 10-2 from above and below. Furthermore, another board 10-3 is arranged under the board 10-1, and the electronic component 30-b is sandwiched between the boards 10-1 and 10-3. The substrates 10-1, 10-2, and 10-3 are all light transmissive.

  Similarly to the second embodiment, the second circuit pattern 50-1a, the through hole 70, the first circuit pattern 40-1a, and the resistor film 140 are formed on one surface of the substrate 10-1. A second circuit pattern 50-1b and a first circuit pattern 40-1b are formed on the other surface. Then, the first circuit pattern 40-1a of the substrate 10-1 and the electrode 31-1 on the lower surface of the electronic component 30-a are fixed. The first circuit pattern 40-1b of the substrate 10-1 and the electrode 31-2 on the upper surface of the electronic component 30-b are fixed.

  On the other hand, the film 41-2 is formed on the other transparent substrate 10-2. The substrate 10-2 is mounted on the electronic component 30-a so that the film 41-2 is in contact with the electrode 31-2 on the upper surface. Then, light is irradiated in a predetermined pattern from the back surface (upper surface) side of the other substrate 10-2 to the upper film 41-2. Thereby, the first circuit pattern 40-2 connected to the electrode 31-2 on the upper surface of the electronic component 30 is formed. At the same time, the first circuit pattern 40-2 and the electrode 31-2 on the upper surface of the electronic component 30 are fixed.

  Further, a film 41-3 is formed on the transparent substrate 10-3. The substrate 10-3 is mounted under the electronic component 30-b so that the film 41-3 is in contact with the electrode 31-1 on the lower surface. Then, the upper film 41-3 is irradiated with light in a predetermined pattern from the back surface (lower surface) side of the substrate 10-3. Thereby, the first circuit pattern 40-3 connected to the electrode 31-1 on the lower surface of the electronic component 30-b is formed. At the same time, the first circuit pattern 40-3 and the electrode 31-1 on the lower surface of the electronic component 30 are fixed.

  Thereby, an electronic device in which the electronic components 30-a and 30-b are sandwiched between the three transparent substrates 10-1, 10-2, and 10-3 can be manufactured.

  Note that the order in which the upper and lower electrodes 31 of the electronic component 30 are connected to the substrates 10-1, 10-2, and 10-3 is not limited to the above order, but is connected first from the side that requires high positional accuracy. It is desirable to do.

  In the configuration of FIG. 8, the second circuit pattern 50-1 formed on the transparent substrate 10-1 and the second circuit pattern 50-2 formed on the transparent substrate 10-2 are vertically Linked in the direction. Similarly, the second circuit pattern 50-1 formed on the transparent substrate 10-1 and the second circuit pattern 50-3 formed on the transparent substrate 10-3 are connected in the vertical direction by the vertical conduction portion 50-5. Yes. The upper and lower conductive portions 50-4, 5 are formed by overlapping the substrates 10-1, 10-2, 10-3 after forming a coating film to be the second circuit patterns 50-1, 50-2, 50-3. The second circuit patterns 50-1, 50-2, and 50-3 are formed in contact with the second circuit patterns 50-1, 50-2, and 50-3 by sintering with light irradiation. They can be formed simultaneously.

  According to this embodiment, it is possible to manufacture an electronic device by mounting various electronic components on the substrate 10 with high density and mounting them in a small number of manufacturing processes. Moreover, since the circuit pattern can be easily changed by light irradiation, it is possible to easily cope with a design change.

  As described above, according to this embodiment, a method for manufacturing a resistor is also provided. That is, a solution in which conductive nano-sized particles having a particle size of less than 1 μm and an insulating material are dispersed, or a solution in which the conductive nano-sized particles coated with an insulating material layer are dispersed is desired on the substrate surface. A first step of forming a film by applying the light in a shape, and irradiating a part of the film with light in a predetermined pattern to sinter the conductive nano-sized particles with the light, thereby conducting the conductive in the predetermined pattern And a second step of forming a resistor film that is a nano-sized particle layer.

  Moreover, according to this Embodiment, the manufacturing method of the circuit board which has a curved board | substrate is also provided. That is, in the first step, a solution in which conductive nanosize particles having a particle diameter of less than 1 μm and an insulating material are dispersed, or a solution in which the conductive nanosize particles coated with an insulating material layer are dispersed is used. Then, it is applied to the substrate surface in a desired shape to form a film containing the conductive nano-sized particles coated with the insulating material. In the second step, the film is irradiated with light in a predetermined pattern, and the conductive nanosize particles are sintered by the light to form a first circuit pattern that is a conductive nanosize particle layer of the predetermined pattern. . A step of bending the substrate is further performed before the first step or after the first step and before the second step.

  As the electronic device of the present embodiment, any device can be applied as long as the electronic component is mounted on a substrate. For example, the present invention can be applied to an instrument panel (instrument display panel) of a car or a display unit of a game machine. In addition, since the substrate can be curved, it can be applied to wearable electronic devices (glasses, watches, displays, medical devices, etc.) and curved displays.

DESCRIPTION OF SYMBOLS 10 ... Board | substrate, 20 ... Area for electronic component mounting, 30 ... Electronic component, 40 ... 1st circuit pattern, 41 ... Membrane, 42 ... Bump, 50 ... 2nd circuit pattern, 60 ... power supply, 80 ... heat transfer member

Claims (8)

The conductive nano-sized particles having a particle size of less than 1 μm, the conductive micro-sized particles having a particle size of 1 μm or more, and the conductive material respectively coated with a solution in which an insulating material is dispersed or an insulating material layer The conductive nanosize particles and the conductive microsize particles coated with the insulating material by applying a solution in which the conductive nanosize particles and the conductive microsize particles are dispersed in a desired shape to the surface of the substrate. A first step of forming a film containing
A second step of filling a through hole provided in the substrate with a conductor,
The second step includes
The substrate is irradiated with light at a predetermined position from the surface opposite to the film, the through-hole is formed in the substrate by the light, and a part of the film is caused to flow into the through-hole to form the through-hole. 2-1 step of filling with the film;
An electronic device comprising: a second step 2-2 for forming the conductor by sintering conductive nano-sized particles and conductive micro-sized particles of the film in the through hole by light irradiation. Manufacturing method. A method of manufacturing an electronic device according to claim 1,
A circuit continuous to the conductor in the through hole by irradiating a predetermined region of the film around the through hole with light to sinter the conductive nano-sized particles and the conductive micro-sized particles. An electronic device manufacturing method, further comprising a third step of forming a pattern. A method for manufacturing an electronic device according to claim 2,
The substrate is light transmissive, and in the third step, the film is irradiated with light from the surface of the substrate opposite to the film through the substrate. A method for manufacturing an electronic device according to claim 2,
The conductive nanosize coated with an insulating material layer or a solution in which conductive nanosize particles having a particle size of less than 1 μm and an insulating material are dispersed in a region where the electronic component on the substrate is to be mounted A fourth step of applying a solution in which particles are at least dispersed to the surface of the substrate in a desired shape to form a film containing the conductive nano-sized particles coated with the insulating material layer;
The film formed in the fourth step is irradiated with light in a predetermined pattern on the film, the conductive nanosize particles are sintered by the light, and the conductive nanosize particle layer having the predetermined pattern is the first layer And a fifth step of forming a circuit pattern. A method for manufacturing an electronic device according to claim 2,
A solution in which conductive nano-sized particles having a particle diameter of less than 1 μm and an insulating material are dispersed in the region on which the electronic component is to be mounted, or the conductive nano-sized particles coated with an insulating material layer A solution in which is dispersed in a desired shape on a substrate surface to form a film containing the conductive nano-sized particles coated with the insulating material layer;
The electronic component is mounted on the film formed in the fourth step so that the electrode is in contact with the film, and the film is irradiated with light in a predetermined pattern from the side opposite to the film of the substrate, and the light And forming a first circuit pattern connected to the electrodes of the electronic component by forming a layer obtained by sintering the conductive nanosize particles of the predetermined pattern and sintering the conductive nanosize particles of the predetermined pattern, An electronic device manufacturing method comprising: a fifth step of fixing the first circuit pattern and the electrode of the electronic component. A substrate, a region provided on the substrate for mounting an electronic component, a first circuit pattern disposed in the region and electrically connected to the electronic component, and connected to the first circuit pattern A second circuit pattern for supplying a current to the first circuit pattern from the outside of the region; a through hole filled with a conductor continuous with the second circuit pattern; An electronic component connected to one circuit pattern,
A part or all of the second circuit pattern and the conductor of the through hole are obtained by sintering conductive nano-sized particles having a particle size of less than 1 μm and conductive micro-sized particles having a particle size of 1 μm or more. An electronic device comprising a material. The conductive nano-sized particles having a particle size of less than 1 μm, the conductive micro-sized particles having a particle size of 1 μm or more, and the conductive material respectively coated with a solution in which an insulating material is dispersed or an insulating material layer The conductive nanosize particles and the conductive microsize particles coated with the insulating material by applying a solution in which the conductive nanosize particles and the conductive microsize particles are dispersed in a desired shape to the surface of the substrate. A first step of forming a film containing
A second step of filling a through hole provided in the substrate with a conductor,
The second step includes
The substrate is irradiated with light from a surface on the opposite side to the film, a through hole is formed in the substrate by the light, a part of the film is caused to flow into the through hole, and the through hole is formed in the film. 2-1 step of filling with,
A circuit board comprising: a step 2-2 for sintering the conductive nano-sized particles and the conductive micro-sized particles of the film in the through hole to form the conductor by light irradiation. Manufacturing method. A substrate, a region provided on the substrate for mounting an electronic component, a first circuit pattern disposed in the region and electrically connected to the electronic component, and connected to the first circuit pattern A second circuit pattern for supplying current to the first circuit pattern from the outside of the region, and a through hole filled with a conductor continuous with the second circuit pattern,
A part or all of the second circuit pattern and the conductor of the through hole are obtained by sintering conductive nano-sized particles having a particle size of less than 1 μm and conductive micro-sized particles having a particle size of 1 μm or more. A circuit board comprising a material.

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