JP2018049982A - Electronic device manufacturing method and electronic device - Google Patents

Abstract

Disclosed is a method for mounting an electronic component on a substrate by photo-baking conductive particles, while preventing damage to the substrate from light irradiation and forming a flexible conductive region. To do. A solution in which conductive particles and an insulating material are dispersed, or a solution in which conductive particles coated with an insulating material layer are dispersed is applied to the surface of a substrate that transmits light, and the insulating material is used. A first step of forming a film of coated conductive particles, a second step of mounting an electronic component having an electrode so that the electrode is in contact with the film, and a region directly below the electrode of the film from the back side of the substrate Conductive electrode connection regions that pass through the substrate and are irradiated with a light beam of a predetermined size, sinter conductive particles in only a partial region of the film, and are respectively fixed to the electrode and the surface of the substrate facing the electrode. A third step of forming. [Selection] Figure 1

Description

  The present invention relates to a method for manufacturing an electronic device in which an electronic component is mounted on a transparent substrate.

  Conventionally, as a method of mounting electronic components on a substrate, bump balls are formed on a substrate on which a circuit pattern has been formed in advance using Au wires, etc., electronic components are mounted on the balls, and electrical by heat and ultrasonic irradiation. In addition, a method for fixing an electronic component to a circuit pattern is known. There is also a method of applying a solder paste to a circuit pattern on a substrate, mounting an electronic component thereon, electrically connecting it by heating and melting the solder, and fixing the electronic component to the circuit pattern. Are known.

  As a method for forming a circuit pattern, a method of masking and etching a copper foil is widely used. However, this method requires a complicated manufacturing process, takes time, and an expensive manufacturing apparatus. Therefore, Patent Document 1 discloses a technique for facilitating the manufacturing process of a substrate on which electronic components are mounted and improving productivity. In this technology, a wiring pattern is formed on a substrate by printing or the like with a conductive ink in which metal nanoparticles and a dispersant such as a polymer are dispersed in a liquid medium, and then an external part of the electronic component is immersed on the wiring pattern. Then, the metal nanoparticles of the wiring pattern are photobaked by irradiating light from the back side of the substrate. In addition, after the wiring pattern is printed, the liquid medium is removed so that the content of the liquid medium is in the range of 0.01 to 3% by mass, and then the electronic component is mounted. This prevents the wiring pattern from collapsing when the electronic component is mounted on the wiring pattern, and prevents voids from being generated inside the wiring pattern during light firing.

JP 2014-17364 A

  However, in the technique of Patent Document 1, a liquid medium in which metal nanoparticles are dispersed is printed in advance in the shape of a wiring pattern, and the metal nanoparticles are photobaked by irradiating light from the back surface of the substrate to the entire substrate. The entire substrate is irradiated with strong light capable of firing the particles. For this reason, when a thin flexible resin substrate is used, the substrate may be deformed by light irradiation. In addition, since the metal nanoparticles are photo-fired so that no voids are generated inside the wiring pattern, the wiring pattern after baking is small in flexibility, and when a flexible substrate is used, the wiring pattern There is a possibility of cracking or peeling off from the substrate.

  An object of the present invention is a method of mounting an electronic component on a substrate by photo-baking conductive particles, and is capable of forming a flexible conductive region that is less likely to be damaged by light irradiation on the substrate. It is to provide a method.

  In order to achieve the above object, the method of manufacturing an electronic device according to the present invention includes a solution in which conductive particles and an insulating material are dispersed, or conductive particles coated with an insulating material layer. First, a solution is applied to the surface of a light-transmitting substrate to form a film of conductive particles coated with an insulating material, and an electronic component having an electrode is mounted so that the electrode is in contact with the film. In two steps, the region directly under the electrode of the film is transmitted through the substrate from the back side of the substrate and irradiated with a light beam of a predetermined size, and the conductive particles in only a partial region of the film are sintered, and the electrode and the substrate And a third step of forming conductive electrode connection regions fixed to surfaces facing the electrodes.

  In the method for manufacturing an electronic device of the present invention, it is difficult to damage the substrate by light for baking conductive particles, and a flexible conductive region can be formed.

(A)-(c) Explanatory drawing which shows the manufacturing method of the electronic device of 1st Embodiment. Explanatory drawing which shows that the electrode connection area | region 40 formed in 1st Embodiment is porous. (A)-(d) Explanatory drawing which shows the manufacturing method of the electronic device of 2nd Embodiment. (A)-(d) Explanatory drawing which shows another manufacturing method of the electronic device of 2nd Embodiment. (A)-(d) Explanatory drawing which shows another manufacturing method of the electronic device of 2nd Embodiment. (A)-(f) Explanatory drawing which shows the manufacturing method of the electronic device of 3rd Embodiment. (A)-(f) Explanatory drawing which shows the manufacturing method of the electronic device of 3rd Embodiment. (A) Sectional drawing of the direction perpendicular | vertical to the upper surface of the board | substrate 10 of the electronic device manufactured by 4th Embodiment, (b) is C-C 'sectional drawing. The electronic device of 5th Embodiment (a) Top view, (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>
A method for manufacturing an electronic device according to the first embodiment will be described with reference to FIGS.

  First, as shown in FIG. 1A, a substrate 10 that transmits light is prepared, and a solution in which conductive particles and an insulating material are dispersed, or conductive particles coated with an insulating material layer are dispersed. The solution is applied to the surface of the substrate 10 in a desired shape. Thereby, a film 41 of conductive particles covered with an insulating material is formed on the surface of the substrate 10. A wiring pattern 11 may be formed on the substrate 10 in advance. When the wiring pattern 11 is arranged in advance, the wiring pattern 11 may be arranged in a shape embedded in the concave portion of the substrate 10 as described in FIGS. 1A, 1B, and 1C. The wiring pattern 11 may be arranged on the upper surface of the substrate 10 so as to be a convex portion. If necessary, the film 41 is heated to evaporate the solvent and dry it. In the film 41, for example, conductive particles represented by conductive nanoparticles are dispersed, and the periphery of the conductive nanoparticles is covered with an insulating material. Therefore, in this step, the film 41 is nonconductive.

  Next, as shown in FIG. 1B, the electronic component 30 having the electrode 31 is mounted so that the electrode 31 is in contact with the film 41.

  Next, as shown in FIG. 1C, a region 12 immediately below the electrode 31 of the film 41 is irradiated with a light beam 12 having a predetermined irradiation diameter through the substrate 10 from the back side of the substrate 10. In the region of the film 41 irradiated with the light flux 12, the conductive particles absorb the energy of light and the temperature rises. As a result, the conductive particles melt at a temperature lower than the bulk melting point of the material constituting the particles, and with the increase in the temperature of the conductive particles, much of the surrounding insulating material layer evaporates, and some of them If it remains, it softens. Therefore, the melted conductive nanoparticles are fused directly with the adjacent particles, or are fused with the adjacent particles through the softened insulating material layer. Thereby, electroconductive particles are sintered and the electroconductive electrode connection area | region 40 is formed. At this time, since the molten conductive particles are fixed to the surface of the electrode 31 and the surface of the substrate 10 that are in direct contact with each other, the conductive electrode connection region 40 to be formed is the electrode 31 and the electrode 31 of the substrate 10. It adheres to the surface facing each. When the wiring pattern 11 is formed on the surface of the substrate 10 immediately below the electrode 31, the electrode connection region 40 is also fixed to the surface of the wiring pattern and is electrically connected. Thereby, an electronic device in which the electronic component 30 is mounted on the substrate 10 can be manufactured.

  As described above, the temperature of the conductive particles in the region of the film 41 that has been irradiated with the light flux 12 rises when irradiated with light. This heat is used to sinter the conductive particles, and is conducted to the electronic component 30 through the surrounding film 41, the substrate 10, and the electrode 31 to be radiated. Therefore, only the region of the film 41 that has been irradiated with the light beam 12 or only the region that has been irradiated with the light beam 12 and its neighboring region reaches the temperature at which the conductive particles are sintered, and the outer region thereof. The temperature of the film 41, the substrate 10 and the electronic component 30 does not reach the temperature at which the materials constituting them are melted or altered.

  That is, in this embodiment, by irradiating only the partial region of the film 41 (the region directly below the electrode 31) with the light flux 12, heat conduction is performed not only to the substrate 10 and the electronic component 30 but also to the surrounding film 41. Since heat can be dissipated, temperature rise of the substrate 10 and the electronic component 30 can be suppressed. Therefore, even if the substrate 10 is easily deformed by heat, such as a thin flexible resin, it is possible to prevent the deformation, distortion, white turbidity, and the like due to light sintering. Further, when the substrate 10 is flexible, the flexibility can be maintained. Further, the electronic component 30 is hardly damaged by heat.

  In the step of FIG. 1C, it is desirable to form the electrode connection region 40 to be porous as shown in FIG. That is, adjacent conductive particles are not completely melted and mixed with each other, but are sintered at the contact interface to form pores 40a in at least a part between the sintered conductive particles. It is desirable to perform photo sintering at such a temperature. For example, by using a laser beam as the luminous flux 12 and irradiating the film 41 with an irradiation intensity that does not melt the substrate 10 that passes through, relatively large energy is applied to the region of the film 41 irradiated with the luminous flux 12 in a short time. The conductive particles can be heated to melt and sinter, and the irradiation with the laser light beam 12 is stopped, so that the conductive particles are quickly cooled by heat conduction to the surrounding film 41, the substrate 10 and the electronic component 30. Therefore, the porous electrode connection region 40 can be formed.

  In other words, when the film 41 is sintered with the laser beam 12, the porous electrode connection region 41 can be formed by adjusting the irradiation intensity of the beam 12 so that the film 41 has an appropriate temperature. . As a specific example, a stretched polyethylene terephthalate (PET) film (melting point: about 250 ° C., heat resistant temperature: about 150 ° C.) is used as the substrate 10, and the laser beam 12 is maintained so that the shape of the substrate 10 is maintained. When the strength is adjusted and the film 41 is irradiated from the back surface of the substrate 10 and the conductive particles of the film 41 are sintered, the porous electrode connection region 40 can be formed.

  In the case where the electrode connection region 40 is porous, the electrode connection region 40 itself has followability (flexibility). Therefore, even when the flexible substrate 10 is deformed, the electrode connection region 40 is accompanied accordingly. Accordingly, the electrode connection region 40 is not easily peeled off from the substrate 10, and cracks and the like are not easily generated. Therefore, it is possible to provide a flexible mounting substrate in which disconnection hardly occurs.

  In the step of FIG. 1C, the irradiation diameter of the light beam 12 on the film 41 may be smaller than that of the electrode 31. In this case, the light beam 12 may be scanned when the required size of the electrode connection region 40 is larger than the irradiation diameter.

  The wavelength of the irradiated light beam 12 is a wavelength that is absorbed by the conductive particles contained in the film 41 and is not easily absorbed by the substrate 10. 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 particles, visible light of 400 to 600 nm can be used.

  Further, the light beam 12 may be formed into a predetermined beam shape through a mask having an opening.

  The region of the film 41 that has not been irradiated with light remains non-conductive because sintering does not occur. The nonconductive film 41 may be removed in a subsequent process. For example, the film 41 can be removed using an organic solvent or the like. Further, it may be separately made conductive by means such as heating.

  As a material of the substrate 10, at least the surface is insulative, has translucency that enables irradiation of the light beam 12, and can withstand a temperature reached by the substrate 10 when the film 12 is irradiated with the light beam 12. Any material can be used as long as it is possible. For example, organic materials such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC), polystyrene (PS), polyimide, epoxy, silicone, glass epoxy substrate, paper phenol, and inorganic materials such as ceramic and glass are used. be able to. Alternatively, a flexible printed circuit board or a metal board whose surface is covered with an insulating layer may be used as long as at least a part of the irradiated light is transmitted. The substrate 10 may be a film.

  As a material for the conductive particles contained in the film 41, one or more of conductive metals and conductive metal oxides such as Au, Ag, Cu, Pd, Ni, ITO, Pt, and Fe may be used. it can. The particle diameter of the conductive particles may be only nanoparticles of less than 1 μm, or nanoparticles of less than 1 μm and microparticles of 1 μm or more may be mixed.

As an insulating material contained at least in the film 41 or an insulating material covering the conductive particles of the film 41, organic materials such as styrene resin, epoxy resin, silicone resin, and acrylic resin, and SiO ₂ , Al One or more of inorganic materials such as ₂ O ₃ and TiO ₂ and organic and inorganic hybrid materials can be used. Moreover, it is preferable that the thickness of the insulating material layer which coat | covers a conductive nanoparticle in the film | membrane 41 is about 1 nm-10 micrometers. If the insulating material layer is too thin, the voltage resistance of the non-conductive film 41 decreases. Moreover, when an insulating material layer is too thick, the electrical conductivity of the electrode connection area | region 40 after sintering by light irradiation will fall, and a thermal resistance value will become large.

  The conductive particles and the insulating material or the conductive particles coated with the insulating material layer are dispersed in a solvent to form a solution to be applied in the step of FIG. As the solvent, an organic solvent or water can be used.

The electrode connection region 40 can be formed to have a size of, for example, 1 μm or more and a thickness of about 1 nm to 10 μm. The electrical resistance value of the electrode connection region 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.

  Any electronic component 30 may be used. For example, a light emitting element (LED, LD), a light receiving element, an integrated circuit, and a display element (liquid crystal display, plasma display, EL display, etc.) are used. be able to. In FIG. 1, only one electronic component 30 is mounted on the substrate 10, but it is of course possible to mount two or more electronic components 30.

  In addition, as a method for forming the film 41 in the process of FIG. 1A, any method may be used as long as the film 41 having a desired film thickness can be formed. When the film 41 is formed by printing, gravure printing, flexographic printing, inkjet printing, screen printing, or the like can be used.

<Second Embodiment>
A second embodiment will be described with reference to FIGS.

  In the first embodiment, the electrode connection region 40 is formed in the film 41. However, in the second embodiment, not only the electrode connection region 40 but also the circuit pattern 43 connected to the electrode connection region 40 is irradiated with the light flux 12. Thus, the film 41 is formed.

  The timing of forming the circuit pattern 43 may be after the step of forming the electrode connection region 40 (FIGS. 3A to 3C) as shown in FIG. As shown in FIG. 4D, after the step of forming the film 41 and mounting the electronic component 30 on the film (FIGS. 4A and 4B), the step of forming the electrode connection region 40 (FIG. 4D). It may be before)). Further, as shown in FIG. 5B, after the step of forming the film 41 (FIG. 5A), the step of mounting the electronic component 30 and forming the electrode connection region 40 (FIG. 5C). ), Before (d)).

  In any case, the substrate 10 is transmitted from the back side of the substrate 10, and a part of the film 41 is irradiated with the light beam 12 in a predetermined pattern, and the conductive particles of the pattern irradiated with the light beam 12 are irradiated. Sinter. Thereby, the circuit pattern 43 connected to the electrode connection region 40 is formed.

  At this time, by scanning the light flux 12, a circuit pattern having a desired shape can be formed with the light flux 12 having a predetermined irradiation diameter. Further, the light beam 12 having a beam shape formed in a desired pattern shape may be irradiated through a mask or the like.

  Similarly to the electrode connection region 40, the circuit pattern 43 is also formed by irradiating only a part of the film 41 with the light beam 12. Therefore, the heat of the sintered part is conducted to the surrounding film 41 and the substrate 10 to dissipate heat. Therefore, the temperature rise of the substrate 10 can be suppressed. Therefore, even if the substrate 10 is easily deformed by heat, such as a thin flexible resin, it is possible to prevent the deformation, distortion, white turbidity, and the like due to light sintering. Further, when the substrate 10 is flexible, the flexibility can be maintained.

  The circuit pattern 43 is also preferably porous, as is the electrode connection region 40. This is because the circuit pattern 43 has followability, is difficult to peel off from the substrate 10, and is not easily broken.

  It is desirable to adjust the irradiation energy of the light beam 12 so that the light beam 12 irradiated when forming the circuit pattern 43 becomes porous. Note that heat is not conducted to the electronic component 30 because the electronic component 30 is not mounted immediately above the circuit pattern 43. Therefore, it is desirable to irradiate the light beam 12 for firing the circuit pattern 43 under different conditions from the irradiation condition of the light beam 12 for photo-firing the electrode connection region 40. For example, the firing can be performed by making the irradiation energy per unit area when the circuit pattern 43 is light-fired smaller than that when the electrode connection region 40 is light-fired.

  Note that the manufacturing process of FIG. 3 or FIG. 4 can improve the manufacturing efficiency because the light beam 12 for forming the electrode connection region 40 and the circuit pattern 43 can be irradiated continuously or simultaneously. Can do.

  In the second embodiment, processes and configurations other than those described above are the same as those in the first embodiment, and thus description thereof is omitted.

<Third Embodiment>
A method for manufacturing an electronic device according to the third embodiment will be described.

  The third embodiment further includes a step of forming the second circuit pattern 44 connected to the circuit pattern 43 formed in the second embodiment by light baking. The second circuit pattern 44 is thicker than the circuit pattern 43 and has a low electrical resistance. Thereby, power from the external power source can be efficiently conducted to the circuit pattern 43 and supplied to the electronic component 30.

  Specifically, as shown in FIG. 6A, a solution in which conductive particles and an insulating material are dispersed, or a solution in which conductive particles coated with an insulating material layer are dispersed is applied to the surface of the substrate 10. To form a second film 45 of conductive particles coated with an insulating material, which is thicker than the film 41.

  Then, as shown in FIG. 6B, the second film 45 is irradiated with the light beam 12 through the substrate 10 from the back side of the substrate 10, and the conductive particles of the second film 45 are irradiated with the light beam 12. And the second circuit pattern 44 is formed.

  These steps can be performed before the step of forming the electrode connection region 40 and the circuit pattern 43 described in the second embodiment shown in FIGS. Note that the steps of FIGS. 6C to 6F can be replaced with other steps such as FIGS. 3 to 5 described in the second embodiment.

  Moreover, you may perform the process of forming the 2nd film | membrane 45 in the middle of the process demonstrated by 2nd Embodiment like Fig.7 (a)-(f). For example, the step of forming the film 45 may be performed as shown in FIG. 7A at any stage prior to the step of photobaking the circuit pattern 43 by irradiation with the light flux 12 (FIG. 7E). Well (as another example, for example, the second film 45 may be formed after the film 41 is formed), and the step of photobaking the second circuit pattern 44 by irradiation with the light beam 12 is performed by the circuit pattern 43 7 (f) can be performed simultaneously or continuously with the step of photo-baking (FIG. 7 (e)). As a result, the circuit pattern 43 and the second circuit pattern 44 can be formed by irradiating the film 41 and the second film 45 with the light beam 12 simultaneously or successively, so that the manufacturing efficiency can be improved. 7B to 7E can be replaced with other steps such as FIGS. 3 to 5 described in the second embodiment.

  The conductive particles contained in the film 45 may be only nano-sized particles, or may be configured to further include micro-sized particles having a particle size of 1 μm or more in addition to the nano-sized particles. Is possible. When the conductive particles include both nanoparticles and microsize particles, the second circuit pattern having a thick film can be easily formed. Specifically, when the film 45 includes both nanoparticles and microsize particles, the thick film 45 can be formed relatively easily as compared with the case where only the nanoparticles are included. In addition, since the film 45 includes both nanoparticles and microsize particles, when the light beam 12 is irradiated onto the film 45, the conductive nanoparticles are melted at a lower temperature than the conductive microparticles, and the adjacent conductive nanoparticles and In order to fuse with the conductive microparticles, sintering starts from the nanoparticles. Therefore, it is possible to sinter at a lower temperature than when the film 45 includes only micro-sized particles.

  The second circuit pattern 44 is desirably porous, like the circuit pattern 43 and the electrode connection region 40. Therefore, it is desirable to adjust the irradiation energy of the light beam 12 in the same manner as when forming the circuit pattern 43 so that the porous second circuit pattern is formed.

When the second circuit pattern 44 contains microparticles, it is desirable that the contained micro-sized conductive particles have a particle diameter of 1 μm to 100 μm. The wiring width of the second circuit pattern 44 can be 10 μm or more, and can be formed to about 100 μm, for example. The thickness of the second circuit pattern 44 can be formed to about 1 μm to 100 μm, for example, about 20 μm. The electric resistance value of the second circuit pattern 44 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.

  In the third embodiment, processes and configurations other than those described above are the same as those in the first and second embodiments, and thus description thereof is omitted.

<Fourth Embodiment>
In the fourth embodiment, as shown in FIG. 1 in the first embodiment, the wiring pattern 11 is provided in advance on the substrate 10. In this embodiment, the wiring pattern 11 and the electrode 31 are arranged so as to overlap each other as shown in FIGS. 8A and 8B, but a light transmission part such as an opening for transmitting the light flux 12 to the wiring pattern 11. 11a is provided. Thereby, the film | membrane 41 can be irradiated with the light beam 12 irradiated from the back surface of the board | substrate 10 through the light transmissive part 11a, and the electrode connection area | region 40 can be provided. Accordingly, even the light-shielding wiring pattern 11 can be arranged so as to overlap the electrode 31. Therefore, since the area where the wiring pattern 11, the electrode connection region 40, and the electrode 31 overlap can be increased, the reliability of the electrical connection between the wiring pattern 11 and the electrode 31 can be improved. Further, the wiring pattern 11 itself may be light transmissive, and in that case, the film 41 is irradiated through the wiring pattern 11 without providing the light transmitting portion 11 a in the wiring pattern 11. An electrode connection region 40 can be provided. A transparent conductive member such as ITO may be used as the light transmissive wiring pattern. Moreover, it is good also as a wiring pattern which has a light transmittance by making a fine mesh shape in a wiring pattern, or providing the micropore for light transmission. Furthermore, by using a porous wiring pattern material, a wiring pattern having optical transparency can be obtained.

<Fifth Embodiment>
An example of the entire configuration of an electronic circuit device that can be manufactured by the manufacturing methods of the first to fifth embodiments will be described with reference to FIGS. 9A, 9 </ b> B, and 9 </ b> C.

  The electronic circuit device shown in FIG. 9 includes a substrate 10 having a circuit pattern and an electronic component 30. A region 20 for mounting the electronic component 30 is provided on the substrate 10, and a circuit pattern 43 (hereinafter referred to as a first circuit pattern 43) that is electrically connected to the electronic component 30 is disposed in the region 20. ing. A second circuit pattern 44 is disposed on the substrate 10, and the second circuit pattern 44 is connected to the first circuit pattern 43 at the peripheral edge of the region 20. The second circuit pattern 44 supplies current to the first circuit pattern 43 from the power supply 60 disposed outside the region 20.

  The 1st circuit pattern 43 and the electrode connection area | region 40 are comprised by the porous conductor which sintered the conductive nanoparticle whose particle size is less than 1 micrometer. Since the first circuit pattern 43 and the electrode connection region 40 are formed by sintering only the portion irradiated with light, the fine first circuit pattern 43 and the electrode connection are adjusted in accordance with the size and arrangement of the electrodes 31 of the electronic component 30. The region 40 can be formed in a desired shape. If there is a region of the film 41 that is not irradiated with light, it is not sintered and remains non-conductive and remains continuously in the first circuit pattern 43. Note that the region of the non-conductive film 41 that is not sintered may be left as it is or may be removed in a later step.

  The thickness of the second circuit pattern 44 is larger than the thickness of the first circuit pattern 43 as shown in FIG. In the present embodiment, the first circuit pattern 43 is formed only in the region 20 where 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 44. Thus, a large current can be supplied to the electronic component 30.

  The power source 60 does not necessarily have to be disposed on the substrate 10. For example, a connector may be disposed on the substrate 10 instead of the power supply 60. In this case, a power supply not mounted on the substrate 10 can be connected to the connector via a cable or the like. The connector is connected to the second circuit pattern. It is also possible to use a power generation device such as a solar battery as the power source 60.

  The substrate 10 can also have a curved shape as shown in FIGS. 9B and 9C. In this case, the first circuit pattern 43 and the second circuit pattern 44 are arranged along the curved surface of the substrate 10. In the present embodiment, the electrode connection region 40, the first circuit pattern 43, and the second circuit pattern 44 are formed of a porous conductor formed by photo-sintering conductive particles. Even if the substrate 10 is curved, it is difficult to disconnect.

  As described above, according to the electronic device manufacturing method of the present embodiment, it is difficult to damage the substrate due to light irradiation while being a method of mounting electronic components on the substrate by photo-baking the conductive particles, In addition, a flexible conductive region can be formed. Further, by irradiating light from the back side of the substrate 10 that transmits light, the electrode connection region 40 connected to the electrode 31 of the electronic component 30 and the circuit patterns 43 and 44 having desired patterns can be directly formed. it can. Since light irradiation can be performed using the position of the electronic component 30 after mounting as a reference, an error in the position between the electronic component 30 and the electrode connection region 40 can be prevented, and poor connection due to misalignment can be reduced. Therefore, a separate bonding material such as solder can be dispensed with.

  Further, since the fine first circuit pattern can be formed with high density by light irradiation, the electronic component 30 can be mounted with high density.

  Furthermore, since it is not necessary to design a circuit pattern in which the mounting deviation of the electronic component 30 and the bonding material supply deviation (position / quantity) are predicted, the first circuit pattern 43 can be designed with higher definition. Can be mounted at higher density.

  Further, the first circuit pattern can be formed by being connected to the thick second circuit pattern 44. Therefore, a large current can be supplied to the electronic component 30 through the first circuit pattern 43 from the low-resistance thick film second circuit pattern 44.

  Since the electrode connection region 40 can be formed after the electronic component 30 is mounted, the mounting position accuracy of the electronic component 30 is improved. Furthermore, in the area smaller than the terminal part of the electronic component 30, the electrode connection region 40 and the electrode can be electrically connected and fixed. In addition, since the electronic component 30 can be fixed on the substrate 10 at the same time, the production tact can be improved.

  According to the present embodiment, it is possible to manufacture an electronic device by collectively mounting various electronic components with high accuracy and high density in a small number of manufacturing processes. In addition, since the circuit pattern can be easily changed by controlling the light irradiation position, it is possible to easily cope with a design change.

  In the embodiment described above, sintering was performed by irradiating with a light beam. However, if the method is to supply energy to only a part of the film and heat it, the same action and method can be used even if a method other than the light beam irradiation is used. An effect is obtained. For example, a method in which microwaves are converged and irradiated, or a method in which a needle-like probe is brought into contact with or close to the film to locally supply current and power can be used.

  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, 31 ... Electrode, 40 ... Electrode mounting area, 43 ... Circuit pattern, 41 ... Membrane, 44 ... second circuit pattern

Claims (20)

A solution in which conductive particles and an insulating material are dispersed, or a solution in which the conductive particles coated with an insulating material layer are dispersed is applied to the surface of a substrate that transmits light, and is coated with the insulating material. A first step of forming a film of the conductive particles;
A second step of mounting an electronic component having an electrode so that the electrode is in contact with the film;
The region directly below the electrode of the film is irradiated with a light beam having a predetermined irradiation diameter through the substrate from the back side of the substrate, and the conductive particles in only a partial region of the film are sintered. And a third step of forming conductive electrode connection regions fixed to the electrodes and the surfaces of the substrate facing the electrodes, respectively.   The method for manufacturing an electronic device according to claim 1, wherein the electrode connection region formed in the third step is porous.   3. The method of manufacturing an electronic device according to claim 1, wherein the light beam irradiated in the third step is a laser beam. 4.   2. The method of manufacturing an electronic device according to claim 1, wherein an irradiation diameter of the light flux on the film is smaller than that of the electrode. 3.   5. The method of manufacturing an electronic device according to claim 1, wherein the method is performed after the first step and before the second step, or after the second step and before the third step. In addition, a part of the film other than the region where the electrode connection region is formed in the third step is transmitted from the back side of the substrate through the substrate, and a predetermined pattern is irradiated with the light beam, and the light beam is irradiated The method further comprises a fourth step of forming a circuit pattern in contact with the electrode connection region when the electrode connection region is formed in the third step by sintering the conductive particles of the formed pattern. An electronic device manufacturing method.   5. The method of manufacturing an electronic device according to claim 1, wherein after the third step, a part of the film is allowed to pass through the substrate from the back side of the substrate, and is predetermined. The method further comprises a fourth step of forming a circuit pattern connected to the electrode connection region by irradiating the pattern with a light beam and sintering the conductive particles of the pattern irradiated with the light beam. A method for manufacturing an electronic device.   7. The method of manufacturing an electronic device according to claim 5, wherein the light beam is scanned in at least one of the third step and the fourth step.   7. The method of manufacturing an electronic device according to claim 5, wherein the irradiation condition of the light beam in the fourth step is different from the irradiation condition of the light beam in the third step. 8. Electronic device manufacturing method.   9. The method of manufacturing an electronic device according to claim 8, wherein the irradiation energy per unit area of the light flux on the film is larger in the third step than in the fourth step. Manufacturing method. 10. The method of manufacturing an electronic device according to claim 5, wherein a solution in which conductive particles and an insulating material are dispersed or the conductive particles coated with an insulating material layer is dispersed. A fifth step of forming a second film of the conductive particles coated with the insulating material, which is thicker than the film formed in the first step, by applying the prepared solution to the surface of the substrate; ,
A second circuit pattern is obtained by irradiating the second film with a light beam through the substrate from the back side of the substrate and sintering the conductive particles of the second film with the light beam. And a sixth step of forming the electronic device.   11. The method of manufacturing an electronic device according to claim 10, wherein the fifth and sixth steps are performed before the first step.   It is a manufacturing method of the electronic device of Claim 10, Comprising: The said 5th process is performed in the stage before the said 4th process, and the said 6th process is simultaneous with the said 4th process, or continuously. A method of manufacturing an electronic device, comprising: irradiating the film and the second film with a light beam simultaneously or successively.   13. The method of manufacturing an electronic device according to claim 1, wherein the conductive particles included in the film formed in the first step have a nanosize having a particle size of less than 1 μm. A method for manufacturing an electronic device, comprising particles.   14. The method of manufacturing an electronic device according to claim 13, wherein the conductive particles contained in the film formed in the first step have a particle size of 1 μm or more in addition to the nano-sized particles. A method for manufacturing an electronic device, further comprising size particles.   13. The method of manufacturing an electronic device according to claim 10, wherein the conductive particles contained in the second film formed in the fifth step are nano particles having a particle diameter of less than 1 μm. A method for producing an electronic device, comprising size particles and microsize particles having a particle size of 1 μm or more.   16. The method of manufacturing an electronic device according to claim 10, wherein the second circuit pattern formed in the sixth step is porous. A method for manufacturing an electronic device. 2. The method of manufacturing an electronic device according to claim 1, wherein a light-shielding circuit pattern is formed in advance on the substrate, and in the second step, the electrode of the electronic component is the light-shielding circuit pattern. And are arranged so that part overlaps,
In the third step, the light beam is irradiated from the back surface side of the substrate onto a light transmission part formed in a part of the light-blocking circuit pattern, further directly below the film just below the electrode. An electronic device manufacturing method. The method for manufacturing an electronic device according to claim 1, wherein a light-transmitting circuit pattern is formed in advance on the substrate, and in the second step, the electrode of the electronic component is the light-transmitting electrode. Arranged so that part of the circuit pattern overlaps,
In the third step, the light flux is irradiated from the back surface side of the substrate onto the light-transmitting circuit pattern further directly under the film directly under the electrode. A light-transmissive substrate, a circuit pattern disposed on the substrate, and the substrate were mounted on the substrate. An electronic component having an electrode, and an electrode connection region for connecting the circuit pattern and the electrode;
The circuit pattern and the electrode connection region are both made of a porous conductor, the circuit pattern is directly fixed to the surface of the substrate, and the electrode connection region is directly fixed to the surface of the substrate and the electrode. An electronic device characterized by that.   20. The electronic device according to claim 19, wherein the circuit pattern is light transmissive.

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