JP7670731B2 - Electrical circuit forming method and electrical circuit forming device - Google Patents

Description

The present invention relates to a method for forming an electrical circuit that electrically connects metal wiring and electronic components.

The following patent document describes a method for forming an electrical circuit that electrically connects metal wiring and electronic components.

JP 2003-152161 A

The objective of this specification is to provide an appropriate electrical connection between metal wiring and electronic components.

In order to solve the above problems, the present specification discloses a method for forming an electric circuit, including a wiring forming step of forming metal wiring on a resin layer, a first application step of applying a conductive fluid by a dispenser to a position on the metal wiring where an electrode of an electronic component is to be mounted, a first curing step of hardening the conductive fluid applied in the first application step, a second application step of applying the conductive fluid by the dispenser to a position on the resin layer where a component body of the electronic component is to be mounted, a mounting step of mounting the electronic component such that the electrode comes into contact with the conductive fluid hardened in the first curing step and the component body comes into contact with the conductive fluid applied and not hardened in the second application step, and a second curing step of hardening the conductive fluid applied in the second application step after the electronic component is mounted in the mounting step.

In the present disclosure, a conductive fluid is applied to the intended mounting position of an electrode of an electronic component on a metal wiring, and the conductive fluid is cured. A conductive fluid is also applied to the intended mounting position of the component body of the electronic component. The electronic component is then mounted so that the electrode contacts the cured conductive fluid and the component body contacts the uncured conductive fluid, and the uncured conductive fluid is then cured. This allows for an appropriate electrical connection between the metal wiring and the electronic component.

FIG. 1 is a diagram showing a circuit forming device. FIG. 2 is a block diagram showing a control device. 1 is a cross-sectional view showing a heat-sensitive release film attached onto a base. FIG. 2 is a cross-sectional view showing a circuit board with a resin laminate formed thereon. FIG. 2 is a cross-sectional view showing a circuit board having wiring formed on a resin laminate. 1 is a cross-sectional view showing a circuit board in a state in which a conductive resin paste is applied onto wiring. 1 is a cross-sectional view showing a circuit board in a state in which a conductive resin paste is applied onto a resin laminate. FIG. 2 is a cross-sectional view showing a circuit board with electronic components mounted thereon. 1 is a cross-sectional view showing a circuit board in a state in which a thermosetting resin has been injected between an upper surface of a resin laminate and a lower surface of a component body of an electronic component. FIG. 4 is a cross-sectional view showing a circuit board with an electronic component pressed against a resin laminate. FIG. 1 is a cross-sectional view showing a circuit board in a state in which a thermosetting resin is discharged around an electronic component. 1 is a cross-sectional view of a circuit board in a state in which it is heated while being compressed;

1 shows the circuit forming device 10. The circuit forming device 10 includes a conveying device 20, a first modeling unit 22, a second modeling unit 23, a third modeling unit 24, a fourth modeling unit 25, a compression unit 26, a mounting unit 27, and a control device (see FIG. 2) 28. The conveying device 20, the first modeling unit 22, the second modeling unit 23, the third modeling unit 24, the fourth modeling unit 25, the compression unit 26, and the mounting unit 27 are arranged on a base 29 of the circuit forming device 10. The base 29 is generally rectangular in shape, and in the following description, the longitudinal direction of the base 29 is referred to as the X-axis direction, the lateral direction of the base 29 is referred to as the Y-axis direction, and the direction perpendicular to both the X-axis direction and the Y-axis direction is referred to as the Z-axis direction.

The transport device 20 includes an X-axis slide mechanism 30 and a Y-axis slide mechanism 32. The X-axis slide mechanism 30 includes an X-axis slide rail 34 and an X-axis slider 36. The X-axis slide rail 34 is disposed on the base 29 so as to extend in the X-axis direction. The X-axis slider 36 is held by the X-axis slide rail 34 so as to be slidable in the X-axis direction. The X-axis slide mechanism 30 also includes an electromagnetic motor (see FIG. 2) 38, and the X-axis slider 36 is moved to any position in the X-axis direction by the drive of the electromagnetic motor 38. The Y-axis slide mechanism 32 also includes a Y-axis slide rail 50 and a stage 52. The Y-axis slide rail 50 is disposed on the base 29 so as to extend in the Y-axis direction and is movable in the X-axis direction. One end of the Y-axis slide rail 50 is connected to the X-axis slider 36. The stage 52 is held on the Y-axis slide rail 50 so as to be slidable in the Y-axis direction. Furthermore, the Y-axis slide mechanism 32 has an electromagnetic motor (see FIG. 2) 56, and the stage 52 moves to an arbitrary position in the Y-axis direction by driving the electromagnetic motor 56. As a result, the stage 52 moves to an arbitrary position on the base 29 by driving the X-axis slide mechanism 30 and the Y-axis slide mechanism 32.

The stage 52 has a base 60, a holding device 62, a lifting device (see FIG. 2) 64, and a heater (see FIG. 2) 66. The base 60 is formed in a flat plate shape, and a substrate is placed on the upper surface. The holding devices 62 are provided on both sides of the base 60 in the X-axis direction. The substrate is fixedly held by clamping both edges in the X-axis direction of the substrate placed on the base 60 between the holding devices 62. The lifting device 64 is disposed below the base 60 and raises and lowers the base 60. The heater 66 is built into the base 60 and heats the substrate placed on the base 60 to a desired temperature.

The first modeling unit 22 is a unit that models the wiring of the circuit board, and has a first printing section 72 and a baking section 74. The first printing section 72 has an inkjet head (see Figure 2) 76 that ejects metal ink in a linear shape. The metal ink is a dispersion of nanometer-sized metal particles, such as silver particles, in a solvent. The surfaces of the metal particles are coated with a dispersant to prevent aggregation in the solvent. The inkjet head 76 also ejects the metal ink from multiple nozzles, for example, by a piezoelectric method using piezoelectric elements.

The baking section 74 has an infrared irradiation device 78 (see Figure 2). The infrared irradiation device 78 is a device that irradiates the ejected metal ink with infrared rays, and the metal ink irradiated with infrared rays is baked to form wiring. Note that baking of metal ink is a phenomenon in which the application of energy causes the evaporation of the solvent and the decomposition of the protective film for the metal particles, i.e., the dispersant, and the like, and the metal particles come into contact or fuse together, thereby increasing the conductivity. Then, as the metal ink is baked, metal wiring is formed.

The second modeling unit 23 is a unit that models the resin layer of the circuit board, and has a second printing unit 84 and a curing unit 86. The second printing unit 84 has an inkjet head (see FIG. 2) 88 that ejects ultraviolet curable resin. The ultraviolet curable resin is a resin that hardens when exposed to ultraviolet light. The inkjet head 88 may be, for example, a piezo type that uses a piezoelectric element, or a thermal type that heats the resin to generate bubbles and ejects the resin from multiple nozzles.

The curing section 86 has a flattening device (see FIG. 2) 90 and an irradiation device (see FIG. 2) 92. The flattening device 90 flattens the top surface of the UV-curable resin discharged by the inkjet head 88, for example by leveling the surface of the UV-curable resin while scraping off excess resin with a roller or blade, thereby making the thickness of the UV-curable resin uniform. The irradiation device 92 has a mercury lamp or LED as a light source, and irradiates the discharged UV-curable resin with ultraviolet light. This hardens the discharged UV-curable resin, forming a resin layer.

The third modeling unit 24 is a unit that models the connection between the electrodes of electronic components and the wiring on the circuit board, and has a third printing unit 100. The third printing unit 100 has a dispenser (see Figure 2) 106 that dispenses conductive resin paste. The conductive resin paste is a resin that hardens when heated at a relatively low temperature and has micrometer-sized metal particles dispersed in it. The metal particles are in the form of flakes, and the viscosity of the conductive resin paste is relatively high compared to metal ink. The amount of conductive resin paste dispensed by the dispenser 106 is controlled by the inner diameter of the needle, the pressure during dispensing, and the dispensing time.

The conductive resin paste dispensed by the dispenser 106 is then heated by the heater 66 built into the base 60, and the resin in the heated conductive resin paste hardens. At this time, the resin in the conductive resin paste hardens and shrinks, and the flake-shaped metal particles dispersed in the resin come into contact with each other. This allows the conductive resin paste to exhibit conductivity. The resin in the conductive resin paste is an organic adhesive, and exerts its adhesive force by hardening when heated.

The fourth modeling unit 25 is a unit that models resin for fixing electronic components to a circuit board, and has a fourth printing unit 110. The fourth printing unit 110 has a dispenser 116 (see FIG. 2) that dispenses thermosetting resin. Thermosetting resin is a resin that hardens when heated. The dispenser 116 is, for example, a piezo type that uses a piezoelectric element. The thermosetting resin dispensed by the dispenser 116 is heated by a heater 66 built into the base 60 and hardens.

The compression unit 26 is a unit for compressing the circuit board, and has a compression section 120. The compression section 120 has a compression plate (see FIG. 10) 122, a rubber sheet (see FIG. 10) 124, and a cylinder (see FIG. 2) 126. The rubber sheet 124 is made of silicon rubber and has a sheet shape with a plate thickness. The compression plate 122 is made of steel and has a plate shape. The rubber sheet 124 is attached to the lower surface of the compression plate 122, and the compression plate 122 is pressed against the circuit board by the operation of the cylinder 126. As a result, the circuit board is compressed by the compression plate 122 via the rubber sheet 124. The force compressing the board can be controllably changed by controlling the operation of the cylinder 126.

The mounting unit 27 is a unit that mounts electronic components on a circuit board, and has a supply section 130 and a mounting section 132. The supply section 130 has a plurality of tape feeders (see FIG. 2) 134 that feed taped electronic components one by one, and supplies the electronic components at a supply position. The supply section 130 is not limited to the tape feeder 134, and may be a tray-type supply device that picks up and supplies electronic components from a tray. The supply section 130 may be configured to include both a tape-type and a tray-type supply device, or other types of supply devices.

The mounting section 132 has a mounting head (see FIG. 2) 136 and a moving device (see FIG. 2) 138. The mounting head 136 has a suction nozzle (not shown) for suctioning and holding electronic components. The suction nozzle suctions and holds electronic components by sucking air when negative pressure is supplied from a positive and negative pressure supply device (not shown). Then, the positive and negative pressure supply device supplies a slight positive pressure to the suction nozzle, which releases the electronic components. The moving device 138 moves the mounting head 136 between the supply position of electronic components by the tape feeder 134 and the board placed on the base 60. As a result, in the mounting section 132, the electronic components supplied from the tape feeder 134 are held by the suction nozzle, and the electronic components held by the suction nozzle are mounted on the board.

2, the control device 28 includes a controller 140 and a plurality of drive circuits 142. The plurality of drive circuits 142 are connected to the electromagnetic motors 38, 56, the holding device 62, the lifting device 64, the heater 66, the inkjet head 76, the infrared irradiation device 78, the inkjet head 88, the flattening device 90, the irradiation device 92, the dispenser 106, the dispenser 116, the cylinder 126, the tape feeder 134, the mounting head 136, and the moving device 138. The controller 140 includes a CPU, ROM, RAM, etc., and is mainly a computer, and is connected to the plurality of drive circuits 142. As a result, the operation of the conveying device 20, the first modeling unit 22, the second modeling unit 23, the third modeling unit 24, the fourth modeling unit 25, the compression unit 26, and the mounting unit 27 is controlled by the controller 140.

In the circuit forming device 10, a resin laminate is formed on the base 60 using the above-mentioned configuration, and wiring is formed on the upper surface of the resin laminate. Then, the electrodes of the electronic components are electrically connected to the wiring via the conductive resin paste, and the electronic components are fixed by the resin to form a circuit board.

Specifically, as shown in FIG. 3, a heat-sensitive peeling film 150 is first laid on the upper surface of the base 60 of the stage 52. The heat-sensitive peeling film 150 has adhesiveness, so it adheres appropriately to the upper surface of the base 60. Then, a circuit board is formed on the heat-sensitive peeling film 150, and the heat-sensitive peeling film 150 adheres closely to the base 60, preventing the circuit board from shifting during circuit formation. Note that the adhesiveness of the heat-sensitive peeling film 150 decreases when heated, so that after the circuit board is formed on the heat-sensitive peeling film 150, the heat-sensitive peeling film 150 can be easily peeled off from the base 60 together with the circuit board formed on the heat-sensitive peeling film 150 by heating the heat-sensitive peeling film 150.

Once the heat-sensitive peel-off film 150 is laid on the base 60, the stage 52 is moved below the second modeling unit 23. Then, in the second modeling unit 23, a resin laminate 152 is formed on the heat-sensitive peel-off film 150 as shown in FIG. 4. The resin laminate 152 has a cavity 154, and is formed by repeatedly ejecting ultraviolet curing resin from the inkjet head 88 and irradiating the ejected ultraviolet curing resin with ultraviolet light by the irradiation device 92.

In detail, in the second printing section 84 of the second modeling unit 23, the inkjet head 88 ejects a thin film of ultraviolet curable resin onto the upper surface of the heat-sensitive peelable film 150. Next, once the ultraviolet curable resin has been ejected in a thin film, the ultraviolet curable resin is flattened by the flattening device 90 in the curing section 86 so that the film thickness of the ultraviolet curable resin is uniform. Then, the irradiation device 92 irradiates the thin film of ultraviolet curable resin with ultraviolet light. As a result, a thin film resin layer 155 is formed on the heat-sensitive peelable film 150.

Next, the inkjet head 88 ejects a thin film of ultraviolet curable resin onto the thin film resin layer 155. The thin film of ultraviolet curable resin is then flattened by the flattening device 90, and the irradiation device 92 irradiates the ejected thin film of ultraviolet curable resin with ultraviolet light, thereby laminating a thin film of resin layer 155 on top of the thin film of resin layer 155. In this manner, ejection of ultraviolet curable resin onto the thin film of resin layer 155 and irradiation with ultraviolet light are repeated, and a plurality of resin layers 155 are laminated to form a first laminate 156.

Next, the inkjet head 88 ejects the ultraviolet curing resin so that a predetermined portion of the upper surface of the first laminate 156 is exposed. The ultraviolet curing resin is then ejected in a thin film, which is then flattened in the curing section 86 so that the film thickness of the ultraviolet curing resin is uniform. The irradiation device 92 then irradiates the thin film of ultraviolet curing resin with ultraviolet light. This forms a thin film layer 157 of resin on the first laminate 156.

Next, the inkjet head 88 ejects the ultraviolet curing resin in a thin film only on the portion above the thin film layer 157. That is, the inkjet head 88 ejects the ultraviolet curing resin in a thin film on the thin film layer 157 so that a predetermined portion of the upper surface of the first laminate 156 is exposed. Then, the thin film of the ultraviolet curing resin is flattened by the flattening device 90, and the irradiation device 92 irradiates the ultraviolet curing resin ejected in a thin film with ultraviolet light, so that the thin film layer 157 is laminated on the thin film layer 157. In this way, the ejection of the ultraviolet curing resin on the thin film layer 157 and the irradiation of ultraviolet light are repeated, and a plurality of thin film layers 157 are laminated to form the second laminate 158. As a result, the second laminate 158 is formed on the first laminate 156, and the step portion between the first laminate 156 and the second laminate 158 functions as the cavity 154 to form the resin laminate 152.

When the resin laminate 152 is formed by the above-mentioned procedure, the stage 52 is moved below the first modeling unit 22. Then, in the first printing section 72 of the first modeling unit 22, the inkjet head 76 ejects the metal ink 160 in a line shape according to the circuit pattern onto the cavity 154 of the resin laminate 152, that is, onto the upper surface of the first laminate 156, as shown in FIG. 5. Next, in the baking section 74 of the first modeling unit 22, the infrared irradiation device 78 irradiates the metal ink 160 ejected according to the circuit pattern with infrared rays. As a result, the metal ink 160 is baked, and a wiring 162 is formed in the cavity 154. In FIG. 5, three wirings 162 are formed, but when distinguishing between the three wirings 162, the wiring on the left side in FIG. 5 is described as wiring 162a, the wiring in the center is described as wiring 162b, and the wiring on the right side is described as wiring 162c.

Next, when the wiring 162 is formed in the cavity 154 of the resin laminate 152, the stage 52 is moved below the third modeling unit 24. Then, in the third printing section 100 of the third modeling unit 24, the dispenser 106 dispenses conductive resin paste 166 onto both ends of the wiring 162b and onto the ends of the wiring 162a and wiring 162c that face both ends of the wiring 162b, as shown in FIG. 6. When the conductive resin paste 166 is dispensed onto the ends of the wiring 162 in this manner, the resin laminate 152 is heated at 105 degrees for one hour by the heater 66 built into the base 60. As a result, the conductive resin paste 166 is heated through the resin laminate 152 and hardened, thereby exhibiting conductivity.

In this way, when the conductive resin paste 166 discharged onto the end of the wiring 162 is cured by heating, the dispenser 106 in the third printing unit 100 discharges the conductive resin paste 170 onto the bottom surface of the cavity 154 between the wiring 162a and the wiring 162b, that is, onto the top surface of the first laminate 156, and onto the top surface of the first laminate 156 between the wiring 162b and the wiring 162c, as shown in FIG. 7. Then, when the conductive resin paste 170 is discharged onto the top surface of the first laminate 156, the stage 52 is moved below the mounting unit 27 while the conductive resin paste 170 is not heated and is in an uncured state. In other words, the conductive resin paste 166 discharged onto the wiring 162 is heated and cured, but the conductive resin paste 170 discharged onto the first laminate 156 is not heated and is in an uncured state while the stage 52 is moved below the mounting unit 27.

In the mounting unit 27, the electronic component 172 (see FIG. 8) is supplied by the tape feeder 134, and the electronic component 172 is held by the suction nozzle of the mounting head 136. The electronic component 172 is composed of a component body 176 and two electrodes 178 arranged on the lower surface of the component body 176. The mounting head 136 is then moved by the moving device 138, and the electronic component 172 held by the suction nozzle is mounted on the upper surface of the resin laminate 152 as shown in FIG. 8. In FIG. 8, two electronic components 172 are mounted on the upper surface of the resin laminate 152, and the two electronic components 172 are different in size. For this reason, the larger electronic component is referred to as electronic component 172a, and the smaller electronic component is referred to as electronic component 172b. Then, the two electronic components 172a and 172b are attached to the upper surface of the resin laminate 152 so that the electronic component 172a is electrically connected to the two wirings 162a and 162b, and the electronic component 172b is electrically connected to the two wirings 162b and 162c.

Specifically, the electronic component 172a is mounted so that the electrode 178 contacts the conductive resin paste 166 in a cured state on the wiring 162a, b. At this time, the component body 176 of the electronic component 172a contacts the conductive resin paste 170 in an uncured state discharged between the wiring 162a, b. Also, the electronic component 172b is mounted so that the electrode 178 contacts the conductive resin paste 166 in a cured state on the wiring 162b, c. At this time, the component body 176 of the electronic component 172b contacts the conductive resin paste 170 in an uncured state discharged between the wiring 162b, c. In other words, the conductive resin paste 166 is discharged at the intended mounting position of the electrode 178 on the wiring 162, and the conductive resin paste 170 is discharged at the intended mounting position of the component body 176. Therefore, when electronic component 172 is attached to resin laminate 152, electrode 178 comes into contact with hardened conductive resin paste 166 on wiring 162, and component body 176 comes into contact with unhardened conductive resin paste 170.

In this way, by mounting the two electronic components 172a and 172b, the electronic component 172a is electrically connected to the two wirings 162a and 162b, and the electronic component 172b is electrically connected to the two wirings 162b and 162c. However, since the electronic component 172 is mounted so that the electrode 178 contacts the conductive resin paste 166 in a cured state, the contact area between the electrode 178 and the conductive resin paste 166 at this point is small. On the other hand, since the component body 176 of the electronic component 172 contacts the conductive resin paste 170 in an uncured state, the contact area between the component body 176 and the conductive resin paste 170 becomes somewhat large. Therefore, the electronic component 172 is fixed to the upper surface of the resin laminate 152 in the component body 176 by the adhesive force of the conductive resin paste 170. Then, the resin laminate 152 is heated to 105 degrees for one hour by the heater 66 built into the base 60. As a result, the conductive resin paste 170 is heated through the resin laminate 152 and hardened.

Next, the stage 52 is moved below the fourth modeling unit 25. Then, in the fourth printing section 110 of the fourth modeling unit 25, the dispenser 116 dispenses the thermosetting resin 180 between the lower surface of the component body 176 of the electronic component 172 and the upper surface of the resin laminate 152, as shown in FIG. 9. As a result, the thermosetting resin 180 is sealed between the upper surface of the resin laminate 152 and the lower surface of the component body 176 of the electronic component 172. That is, the thermosetting resin 180 is sealed between the upper surface of the resin laminate 152 and the lower surface of the component body 176. Note that the amount of the thermosetting resin 180 dispensed by the dispenser 116 is controlled so that the thermosetting resin 180 does not protrude from between the upper surface of the resin laminate 152 and the lower surface of the component body 176. Then, the resin laminate 152 is heated to 70 degrees for 30 minutes by the heater 66 built into the base 60. As a result, the thermosetting resin 180 is heated and hardened through the resin laminate 152. Note that the thermosetting resin 180 does not harden completely even when heated at 70 degrees for 30 minutes. Therefore, the thermosetting resin 180 is in a semi-hardened state at this point.

When the thermosetting resin 180 injected between the upper surface of the resin laminate 152 and the lower surface of the component body 176 is semi-cured in this manner, the stage 52 is moved below the compression unit 26. Then, in the compression section 120 of the compression unit 26, as shown in FIG. 10, the electronic component 172 attached to the resin laminate 152 is compressed from above to below by the compression plate 122 via the rubber sheet 124. During compression by the compression plate 122, the operation of the cylinder 126 is controlled, and the compression force by the compression plate 122 is set to 200 kgf. The two electronic components 172a, b are attached to the cavity 154 of the resin laminate 152, but the depth dimension of the cavity 154 is smaller than the height dimension of the two electronic components 172. Therefore, the upper surfaces of the two electronic components 172a, b extend above the cavity 154, and the two electronic components 172 can be compressed from above to below by the compression plate 122. Furthermore, as described above, the sizes of the two electronic components 172 are different, and therefore the height dimensions are also different, but a rubber sheet 124 is attached to the lower surface of the compression plate 122. As a result, when the two electronic components 172a, b are compressed, the rubber sheet 124 elastically deforms, and the two electronic components 172a, b with different height dimensions can be appropriately compressed.

When the electronic components are compressed in the compression unit 26, the resin laminate 152 is heated at 85 degrees for 45 minutes by the heater 66 built into the base 60. As a result, the thermosetting resin 180 is heated and hardened through the resin laminate 152. The thermosetting resin 180 is completely hardened by being heated at 85 degrees for 45 minutes. As a result, the thermosetting resin 180 is completely hardened while being sealed between the upper surface of the resin laminate 152 and the lower surface of the component body 176. As the electronic components 172 are compressed, that is, the electronic components 172 mounted on the resin laminate 152 are pressed against the resin laminate 152, the conductive resin paste 166 in contact with the electrodes 178 of the electronic components 172 is deformed, and the contact area between the electrodes 178 and the conductive resin paste 166 is increased. In particular, the Young's modulus of the conductive resin paste 166 is low in the hardened state. The Young's modulus is a proportional constant between the amount of strain and stress in the elastic range, and is the ratio of stress to the amount of strain. Therefore, when an object with a high Young's modulus and an object with a low Young's modulus are deformed with the same stress, the object with the low Young's modulus deforms more than the object with the high Young's modulus. In other words, an object with a low Young's modulus is easily deformed. In this way, the conductive resin paste 166 with a low Young's modulus is deformed by being pressed by the electrode 178, and the contact area between the electrode 178 and the conductive resin paste 166 increases. This ensures the electrical connection between the electronic component 172 and the wiring 162. In addition, when the electronic component 172 mounted on the resin laminate 152 is pressed against the resin laminate 152, the conductive resin paste 170 in contact with the component body 176 of the electronic component 172 is also deformed, and the contact area between the component body 176 and the conductive resin paste 170 also increases. In this way, the contact area between the component body 176 and the conductive resin paste 170 is also increased, and the adhesive strength of the conductive resin paste 170 allows the electronic component 172 to be suitably fixed to the resin laminate 152 .

Then, when the compression by the compression plate 122 in the compression unit 26 is completed, the stage 52 is moved below the fourth modeling unit 25. Then, in the fourth printing section 110 of the fourth modeling unit 25, the dispenser 116 dispenses the thermosetting resin 190 around the electronic component 172 so as to cover the side of the component body 176 of the electronic component 172, as shown in FIG. 11. Then, the heater 66 built into the base 60 heats the resin laminate 152 at 85 degrees for 45 minutes. As a result, the thermosetting resin 190 is heated through the resin laminate 152 and hardens. The thermosetting resin 190 is completely hardened by being heated at 85 degrees for 45 minutes. As a result, the thermosetting resin 190 hardens while covering the side of the component body 176. That is, in electronic component 172 mounted on resin laminate 152, thermosetting resins 180, 190 are sealed between the upper surface of resin laminate 152 and the lower surface of component body 176, and harden in a state covering the side surfaces of component body 176. As a result, electronic component 172 mounted on the upper surface of resin laminate 152 is fixed by the hardened resin.

In this way, the electronic components 172 mounted on the upper surface of the resin laminate 152 are fixed by the hardened resin, and the circuit board 200 is formed on the upper surface of the base 60 on the heat-sensitive release film 150. Then, in order to peel the heat-sensitive release film 150 from the formed circuit board 200, the heat-sensitive release film 150 is heated by a heater 66 built into the base 60. At this time, the circuit board 200 is also heated, which may cause the circuit board 200 to warp. Therefore, when the heat-sensitive release film 150 is heated, the heat-sensitive release film 150 is heated while compressing the circuit board 200.

When the electronic components 172 mounted on the upper surface of the resin laminate 152 are fixed by the hardening of the thermosetting resin 190, the stage 52 is moved below the compression unit 26. Then, in the compression section 120 of the compression unit 26, as shown in FIG. 12, the entire circuit board 200 is compressed downward by the compression plate 122 through the rubber sheet 124. During compression by the compression plate 122, the operation of the cylinder 126 is controlled, and the compression force by the compression plate 122 is set to 5 kg. During compression by the compression plate 122, the heat-sensitive release film 150 is heated at 130 degrees for one hour by the heater 66 built into the base 60. This reduces the adhesiveness of the heat-sensitive release film 150, and the circuit board 200 can be easily peeled off from the base 60 together with the heat-sensitive release film 150. Then, by peeling the heat-sensitive release film 150 from the circuit board 200, the formation of the circuit board 200 is completed.

By forming the circuit board 200 by such a method, the conductivity between the wiring 162 and the electrode 178 of the electronic component 172 can be properly ensured, compared to a circuit board formed by a conventional method. In detail, in the conventional method, after the conductive resin paste 166 is discharged onto the wiring 162, the electronic component 172 is mounted before the conductive resin paste 166 is hardened. In other words, the electronic component 172 is mounted so that the electrode 178 contacts the conductive resin paste 166 in an unhardened state. Then, the conductive resin paste 166 in contact with the electrode 178 is heated and hardened. However, the conductivity of the conductive paste decreases when it is deformed or stress is applied during thermal hardening. For this reason, when a circuit board is formed by the conventional method, the conductivity between the wiring 162 and the electrode 178 of the electronic component 172 cannot be properly ensured.

In view of this, in the circuit forming device 10, as described above, when the conductive resin paste 166 is discharged onto the wiring 162, the conductive resin paste 166 is heated and cured before the electronic component 172 is attached. In other words, the conductive resin paste 166 is heated and cured without being deformed or subjected to stress. This makes it possible to prevent a decrease in conductivity when the conductive resin paste 166 is cured. Then, the electronic component 172 is attached so that the electrode 178 contacts the conductive resin paste 166 in the cured state. In this way, the conductive resin paste 166 is cured before the electronic component 172 is attached, and the electronic component 172 is attached so that the electrode 178 contacts the conductive resin paste 166 in the cured state, thereby appropriately ensuring the conductivity between the wiring 162 and the electronic component 172.

Furthermore, in the circuit forming device 10, when the electronic component 172 is attached to the resin laminate 152, the electronic component 172 attached to the resin laminate 152 is pressed against the resin laminate 152 in the compression unit 26. At this time, the electrode 178 is pressed against the conductive resin paste 166, increasing the contact area between the electrode 178 and the conductive resin paste 166, and the electrode 178 and the conductive resin paste 166 are brought into close contact with each other. In this way, by increasing the contact area between the electrode 178 and the conductive resin paste 166 and bringing the electrode 178 and the conductive resin paste 166 into close contact with each other, the conductivity between the wiring 162 and the electronic component 172 can be appropriately ensured.

As described above, the circuit board 200 is formed from a plurality of materials, such as ultraviolet curing resin, metal ink, conductive resin paste, and thermosetting resin, and therefore stress is likely to occur at the connection between the electronic component 172 and the wiring 162 when the temperature changes due to the difference in the linear expansion coefficient of the plurality of materials. For this reason, it is desirable to suitably fix the electronic component 172 in the resin laminate 152 in order to ensure the connection between the electronic component 172 and the wiring 162. In view of this, in the circuit forming device 10, before the electronic component 172 is mounted on the resin laminate 152, the conductive resin paste 166 in contact with the electrode 178 is heated, but the conductive resin paste 170 in contact with the component body 176 is not heated. In other words, when the electronic component 172 is mounted on the resin laminate 152, the component body 176 comes into contact with the conductive resin paste 170 in an uncured state. For this reason, the contact area between the component body 176 and the conductive resin paste 170 becomes somewhat large. As a result, electronic component 172 can be fixed to resin laminate 152 by the adhesive force of conductive resin paste 170. Furthermore, after conductive resin paste 170 is heated and hardened, electronic component 172 attached to resin laminate 152 is pressed against resin laminate 152 in compression unit 26. At this time, component body 176 is pressed against conductive resin paste 170, increasing the contact area between component body 176 and conductive resin paste 170. This allows electronic component 172 to be further suitably fixed to resin laminate 152.

In addition, in the electronic component 172 mounted on the resin laminate 152, the thermosetting resins 180, 190 are sealed between the upper surface of the resin laminate 152 and the lower surface of the component body 176, and harden while covering the side surface of the component body 176. This allows the electronic component 172 mounted on the upper surface of the resin laminate 152 to be suitably fixed by the thermosetting resin. Furthermore, when the heat-sensitive peeling film 150 is heated, the circuit board 200 is compressed, thereby preventing warping of the circuit board 200. In this way, the electronic component 172 can be suitably fixed to the resin laminate 152 by preventing warping of the circuit board 200.

As shown in FIG. 2, the controller 140 of the control device 28 has a resin layer forming section 210, a wiring forming section 212, a first applying section 214, a first curing section 216, a second applying section 218, a mounting section 220, a second curing section 222, an injection section 224, a third curing section 226, and a peeling section 228. The resin layer forming section 210 is a functional section for forming a resin laminate 152 with ultraviolet curing resin. The wiring forming section 212 is a functional section for forming wiring 162 with metal ink 160. The first applying section 214 is a functional section for applying conductive resin paste 166 to the intended mounting position of the electrode 178 on the wiring. The first curing section 216 is a functional section for curing the conductive resin paste 166 applied on the wiring. The second applying section 218 is a functional section for applying conductive resin paste 170 to the intended mounting position of the component body 176. The mounting section 220 is a functional section for mounting the electronic component 172 so that the electrode 178 contacts the cured conductive resin paste 166 and the component body 176 contacts the uncured conductive resin paste 170. The second curing section 222 is a functional section for curing the conductive resin paste 170 in contact with the component body. The injection section 224 is a functional section for injecting the thermosetting resin 180 between the upper surface of the resin laminate 152 and the lower surface of the component body 176. The third curing section 226 is a functional section for curing the thermosetting resin 180 injected between the upper surface of the resin laminate 152 and the lower surface of the component body 176 while pressing the electronic component 172 against the resin laminate 152. The peeling section 228 is a functional section for heating and peeling off the heat-sensitive release film 150 while applying pressure to the entire circuit board 200.

In the above embodiment, the rubber sheet 124 is an example of an elastic body. The heat-sensitive peeling film 150 is an example of a peeling sheet. The resin laminate 152 is an example of a resin layer. The wiring 162 is an example of a metal wiring. The conductive resin pastes 166 and 170 are an example of a conductive fluid. The electronic component 172 is an example of an electronic component. The component body 176 is an example of a component body. The electrode 178 is an example of an electrode. The thermosetting resin 180 is an example of a curable resin. The process performed by the resin layer forming unit 210 is an example of a resin forming process. The process performed by the wiring forming unit 212 is an example of a wiring forming process. The process performed by the first applying unit 214 is an example of a first applying process. The process performed by the first curing unit 216 is an example of a first curing process. The process performed by the second applying unit 218 is an example of a second applying process. The process performed by the mounting unit 220 is an example of a mounting process. The process performed by the second curing unit 222 is an example of a second curing process. The process performed by the injection unit 224 is an example of an injection process. The process performed by the third curing unit 226 is an example of a third curing process. The process performed by the peeling unit 228 is an example of a peeling process.

The present invention is not limited to the above embodiment, and can be implemented in various forms with various modifications and improvements based on the knowledge of those skilled in the art. For example, in the above embodiment, the thermosetting resin is discharged between the upper surface of the resin laminate 152 and the lower surface of the component body 176 of the electronic component 172. If the thermosetting resin overflows between the upper surface of the resin laminate 152 and the lower surface of the component body 176, it is desirable to suck up the overflowing thermosetting resin. The thermosetting resin may be sucked up manually by an operator or automatically by a sucking device or the like.

In addition, in the above embodiment, the circuit board is compressed by the compression plate 122 via the rubber sheet 124, but the circuit board may be compressed by the compression plate 122 via various members as long as they are elastically deformable members. For example, silicon-based resin, urethane-based resin, etc. can be used as the elastically deformable member.

In addition, in the above embodiment, a conductive resin paste 166 is used as the fluid that electrically connects the wiring 162 and the electrode 178 of the electronic component 172, but various fluids can be used as long as they exhibit conductivity.

In the above embodiment, ultraviolet curable resin and thermosetting resin are used as the curable resin, but two-liquid mixed curable resin, thermoplastic resin, etc. may be used. In the above embodiment, ultraviolet curable resin is used as the resin forming the resin laminate 152, and thermosetting resin is used as the resin fixing the lower surface and periphery of the electronic component 172. In other words, the resin forming the resin laminate 152 and the resin fixing the lower surface and periphery of the electronic component 172 are different thermosetting resins, but the resin forming the resin laminate 152 and the resin fixing the lower surface and periphery of the electronic component 172 may be the same thermosetting resin.

In the above embodiment, the conductive resin paste is dispensed by the dispenser 106, but it may be transferred by a transfer device or the like. The conductive resin paste may also be printed by screen printing.

124: Rubber sheet (elastic body), 150: Heat-sensitive release film (release sheet), 152: Resin laminate (resin layer), 162: Wiring (metal wiring), 166: Conductive resin paste (conductive fluid), 170: Conductive resin paste (conductive fluid), 172: Electronic component, 176: Component body, 178: Electrode, 180: Thermosetting resin (hardening resin), 210: Resin layer forming section (resin layer forming process), 212: Wiring forming section (wiring forming process), 214: First application section (first application process), 216: First curing section (first curing process), 218: Second application section (second application process), 220: Mounting section (mounting process), 222: Second curing section (second curing process), 224: Injection section (injection process), 226: Third curing section (third curing process), 228: Peeling section (peeling process)

Claims (8)

a wiring forming step of forming metal wiring on the resin layer;
a first application step of applying a conductive fluid to a position on the metal wiring where an electrode of an electronic component is to be mounted, using a dispenser ;
a first curing step of curing the conductive fluid applied in the first application step;
a second application step of applying a conductive fluid to a position on the resin layer where a component body of the electronic component is to be mounted by the dispenser ;
a mounting step of mounting the electronic component such that the electrode contacts the conductive fluid that has been hardened in the first hardening step and the component body contacts the conductive fluid that has been applied in the second application step and has not been hardened;
a second curing step of curing the conductive fluid applied in the second application step after the electronic components are mounted in the mounting step. an injection step of injecting a curable resin between the electronic component and the resin layer after the conductive fluid is cured in the second curing step;
2. The method for forming an electric circuit according to claim 1, further comprising: a third curing step of curing the curable resin while pressing the electronic component against the resin layer after the curable resin is injected in the injection step. The third curing step comprises:
3. The method for forming an electric circuit according to claim 2, wherein the hardening resin is hardened while a plate-like elastic body is placed on the electronic component and the electronic component is pressed against the resin layer via the elastic body. a compression step of pressing the electronic component against the resin layer after the conductive fluid is cured in the second curing step,
2. The method for forming an electrical circuit according to claim 1, wherein the conductive fluid has a Young's modulus low enough that, in its hardened state, the conductive fluid is deformed by being pressed by the electrode in the compression step, thereby increasing the contact area between the electrode and the conductive fluid. a resin layer forming step of forming the resin layer on a release sheet that is peeled off by heating;
5. The method for forming an electric circuit according to claim 1, further comprising: a peeling step of heating the release sheet while applying pressure to the entire resin layer after the circuit is formed, to peel off the release sheet from the resin layer. a first modeling unit that ejects metal ink to model metal wiring;
a second modeling unit that ejects a curable resin to model a resin layer;
a third modeling unit having a dispenser that dispenses a conductive fluid;
A heater and
Equipped with
The resin layer is formed by the second modeling unit,
forming a metal wiring on the resin layer by the first modeling unit;
applying the conductive fluid to a position on the metal wiring where an electrode of an electronic component is to be attached by the dispenser ;
The conductive fluid applied onto the metal wiring is hardened by the heater;
applying a conductive fluid to a position on the resin layer where a component body of the electronic component is to be mounted by the dispenser ;
An electrical circuit forming apparatus which hardens the conductive fluid on the resin layer with the electronic component mounted such that the electrode contacts the hardened conductive fluid on the metal wiring and the component body contacts the unhardened conductive fluid on the resin layer. a mounting unit for mounting the electronic component,
7. The electrical circuit forming apparatus according to claim 6, wherein the mounting unit mounts the electronic component such that the electrode contacts the hardened conductive fluid on the metal wiring and the component body contacts the unhardened conductive fluid on the resin layer. The compression unit further includes a plate-shaped elastic body.
After the conductive fluid on the resin layer is hardened, the compression unit presses the electronic component against the resin layer via the elastic body in a state in which the elastic body is placed on the mounted electronic component;
8. The electrical circuit forming device according to claim 6, wherein the conductive fluid has a Young's modulus low enough that, in a hardened state, the conductive fluid is deformed by being pressed against the electrodes by the compression unit, thereby increasing the contact area between the electrodes and the conductive fluid.

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