Patent Description:
Conventionally, a technique for molding a molded object using a resin material has been developed. For example, Patent Literature <NUM> discloses a technique related to a molding device for molding a molded object using an ultraviolet curable resin. The molding device of Patent Literature <NUM> is provided with a roller for flattening the ultraviolet curable resin discharged from the discharge unit. The roller rotates in a state of being in contact with the discharged layer of the ultraviolet curable resin, so that the ultraviolet curable resin on the surface of the layer is scraped off to flatten the surface. <CIT> and <CIT> disclose methods according to the preamble of claim <NUM>.

In a flattening step using the roller described above, flattening is executed by transferring a predetermined amount of the ultraviolet curable resin from the layer of the ultraviolet curable resin to the surface of the roller, and scraping off the ultraviolet curable resin. In a case where the transfer amount of the ultraviolet curable resin to the roller is small, there is a possibility that unevenness may remain on the surface of the layer of the ultraviolet curable resin, and the surface may not be sufficiently flattened. Therefore, a flattening technique for increasing the transfer amount of the ultraviolet curable resin to the roller is desired.

The present disclosure has been made in view of the above-described actual circumstances, and an object thereof is to provide a molding method capable of flattening a discharged resin material by using a roller.

In order to solve the above-described problems, a molding method according to the present disclosure includes a discharging step of discharging a resin material on a cured resin layer, a flattening step of transferring a part of the resin material discharged by the discharging step from the cured resin layer to a roller to flatten the resin material, and a curing step of irradiating the resin material flattened by the flattening step with light having a predetermined light amount to cure the resin material, and forming a new cured resin layer on the cured resin layer, in which the discharging step, the flattening step, and the curing step are repeatedly executed, and the cured resin layer is laminated, and the light amount is used in which a first contact angle of the resin material with respect to the cured resin layer is larger than a second contact angle of the resin material with respect to the roller.

As a result, when the discharge, flattening, and curing of the resin material are repeatedly executed, the light amount in which the first contact angle of the resin material with respect to the cured resin layer is larger than the second contact angle of the resin material with respect to the roller is used. As a result, by setting the first contact angle of the cured resin layer relatively larger than the second contact angle of the roller, the resin material is easily repelled from the cured resin layer, and the resin material is easily transferred to the roller. Accordingly, by adjusting the light amount in the curing step, the amount of transfer to the roller in the flattening step can be increased, and the resin material can be further flattened using the roller. It is possible to suppress the unevenness of the surface of the cured resin layer.

Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the drawings. <FIG> illustrates mounting board manufacturing apparatus <NUM>. Mounting board manufacturing apparatus <NUM> is provided with conveyance device <NUM>, first molding unit <NUM>, second molding unit <NUM>, mounting unit <NUM>, third molding unit <NUM>, and control device <NUM> (refer to <FIG> and <FIG>). Conveyance device <NUM>, first molding unit <NUM>, second molding unit <NUM>, mounting unit <NUM>, and third molding unit <NUM> are disposed on base <NUM> of mounting board manufacturing apparatus <NUM>. Base <NUM> has normally rectangular in a plan view. In the following description, a longitudinal direction of base <NUM> will be referred to as an X-axis direction, a shorter direction of base <NUM> will be referred to as a Y-axis direction, and a direction orthogonal to both the X-axis direction and the Y-axis direction will be referred to as a Z-axis direction.

Conveyance device <NUM> is provided with X-axis slide mechanism <NUM> and Y-axis slide mechanism <NUM>. X-axis slide mechanism <NUM> includes X-axis slide rail <NUM> and X-axis slider <NUM>. X-axis slide rail <NUM> is disposed to extend in the X-axis direction on base <NUM>. X-axis slider <NUM> is held by X-axis slide rail <NUM> to be slidable in the X-axis direction. Furthermore, X-axis slide mechanism <NUM> includes electromagnetic motor <NUM> (refer to <FIG>) and moves X-axis slider <NUM> to any position in the X-axis direction by driving electromagnetic motor <NUM>. In addition, Y-axis slide mechanism <NUM> includes Y-axis slide rail <NUM> and stage <NUM>. Y-axis slide rail <NUM> is disposed to extend in the Y-axis direction on base <NUM>. One end portion of Y-axis slide rail <NUM> is connected to X-axis slider <NUM>. Therefore, Y-axis slide rail <NUM> is movable in the X-axis direction. Stage <NUM> is held by Y-axis slide rail <NUM> so as to be slidable in the Y-axis direction. Y-axis slide mechanism <NUM> includes electromagnetic motor <NUM> (refer to <FIG>) and moves stage <NUM> to any position in the Y-axis direction by driving electromagnetic motor <NUM>. As a result, by driving X-axis slide mechanism <NUM> and Y-axis slide mechanism <NUM>, stage <NUM> is moved to any position on base <NUM>.

Stage <NUM> includes base plate <NUM>, holding device <NUM>, and lifting and lowering device <NUM>. Base plate <NUM> is formed in a flat plate shape, and base material <NUM> is placed on an upper surface thereof. Holding device <NUM> is provided on both side portions of base plate <NUM> in the X-axis direction. Holding device <NUM> fixedly holds base material <NUM> with respect to base plate <NUM> by interposing both edge portions in the X-axis direction of base material <NUM> placed on base plate <NUM>. In addition, lifting and lowering device <NUM> is disposed below base plate <NUM>, and lifts and lowers base plate <NUM> in the Z-axis direction.

First molding unit <NUM> is a unit for molding wiring on base material <NUM> placed on base plate <NUM> of stage <NUM>, and includes first printing section <NUM> and firing section <NUM>. First printing section <NUM> has ink jet head <NUM> (refer to <FIG>) and linearly discharges conductive ink on base material <NUM> placed on base plate <NUM>. The conductive ink is an example of a fluid containing metal particles of the present disclosure. The conductive ink includes, for example, fine particles of metal (such as silver) having a nanometer size as the main component dispersed in a solvent, and is cured by firing with heat. The conductive ink includes, for example, metal nanoparticles having a size of several hundred nanometers or less. The surface of the metal nanoparticle is coated with, for example, a dispersant to suppress aggregation in the solvent.

Ink jet head <NUM> discharges conductive ink from multiple nozzles, for example, by a piezo method using piezoelectric elements. In addition, the device for discharging conductive ink (fluid containing metal nanoparticles) is not limited to an inkjet head including multiple nozzles, and may be a dispenser including one nozzle, for example. In addition, the type of metal nanoparticles included in the conductive ink is not limited to silver, and may be copper, gold, or the like. In addition, the number of types of metal nanoparticles included in the conductive ink is not limited to one type, and may be multiple types.

Firing section <NUM> includes irradiation device <NUM> (refer to <FIG>). Irradiation device <NUM> is provided with, for example, an infrared heater that heats the conductive ink discharged on base material <NUM>. The conductive ink is fired by applying heat from an infrared heater to form wiring. The firing of the conductive ink referred to herein means, for example, a phenomenon in which by applying energy, a solvent is vaporized or a protective film of the metal nanoparticles, that is, a dispersant is decomposed, and the metal nanoparticles are brought into contact with each other or fused to increase the conductivity. The wiring can be formed by firing the conductive ink. The device for heating the conductive ink is not limited to an infrared heater. For example, mounting board manufacturing apparatus <NUM> may include an infrared lamp, a laser irradiation device for irradiating the conductive ink with laser light, or an electric furnace in which base material <NUM> from which the conductive ink is discharged is placed in a furnace and heated, as a device for heating the conductive ink.

In addition, second molding unit <NUM> is a unit for molding a resin layer on base material <NUM> placed on base plate <NUM>, and includes second printing section <NUM> and curing section <NUM>. Second printing section <NUM> includes ink jet head <NUM> (refer to <FIG>), and discharges ultraviolet curable resin <NUM> on base material <NUM> placed on base plate <NUM> (refer to <FIG>). Ultraviolet curable resin <NUM> is a resin that is cured by irradiation with ultraviolet rays. A method by which ink jet head <NUM> discharges ultraviolet curable resin <NUM> may be, for example, a piezo method using a piezoelectric element, or may be a thermal method in which a resin is heated to generate air bubbles and discharged from multiple nozzles.

Curing section <NUM> includes flattening device <NUM> (refer to <FIG>) and irradiation device <NUM> (refer to <FIG>). Flattening device <NUM> is a device for flattening an upper surface of ultraviolet curable resin <NUM> discharged on base material <NUM> by ink jet head <NUM>. For example, as illustrated in <FIG>, flattening device <NUM> includes roller <NUM> and collection section <NUM>. Flattening device <NUM> scrapes off the excess resin by roller <NUM> while leveling the surface of ultraviolet curable resin <NUM>, so that the thickness of ultraviolet curable resin <NUM> is uniform. Roller <NUM> has, for example, a cylindrical shape, and moves while rotating the surface of ultraviolet curable resin <NUM> in a flowable state based on the control of flattening device <NUM> to flatten the surface. Collection section <NUM> has, for example, a blade protruding toward the surface of roller <NUM>, and stores and discharges ultraviolet curable resin <NUM> scraped by the blade. For example, collection section <NUM> discharges collected ultraviolet curable resin <NUM> to a waste liquid tank. Collection section <NUM> may return the collected ultraviolet curable resin <NUM> to the supply tank again. Flattening device <NUM> scrapes off an excess of ultraviolet curable resin <NUM> while leveling the surface of ultraviolet curable resin <NUM> to flatten the surface of ultraviolet curable resin <NUM>.

In addition, irradiation device <NUM> includes, for example, a mercury lamp or an LED as a light source. As illustrated in <FIG>, irradiation device <NUM> irradiates ultraviolet curable resin <NUM> (refer to <FIG>) discharged on base material <NUM> with ultraviolet rays. As a result, ultraviolet curable resin <NUM> discharged on base material <NUM> is cured, and thin-film cured resin layer <NUM> can be formed.

Mounting unit <NUM> is a unit for disposing an electronic component on base material <NUM> placed on base plate <NUM>, and includes supply section <NUM> and mounting section <NUM>. Supply section <NUM> includes multiple tape feeders <NUM> (refer to <FIG>) for feeding the taped electronic components one by one, and supplies the electronic components at each supply position. The electronic component is, for example, a sensor element such as a temperature sensor. The supply of the electronic components is not limited to the supply by tape feeder <NUM>, and may be performed by a tray.

Mounting section <NUM> includes mounting head <NUM> (refer to <FIG>) and moving device <NUM> (refer to <FIG>). Mounting head <NUM> includes a suction nozzle for picking up and holding an electronic component. The suction nozzle picks up and holds the electronic component by suction of air by supplying a negative pressure from a positive and negative pressure supply device (not illustrated). The electronic component is separated by supplying a slight positive pressure from the positive and negative pressure supply device. In addition, moving device <NUM> moves mounting head <NUM> between the supply position of tape feeder <NUM> and base material <NUM> placed on base plate <NUM>. As a result, mounting section <NUM> holds the electronic component by the suction nozzle, and disposes the electronic component held by the suction nozzle on base material <NUM>.

Third molding unit <NUM> is a unit for applying a conductive paste on base material <NUM> placed on base plate <NUM>. The conductive paste is, for example, a viscous fluid in which micro-sized metal particles (for example, micro filler) are included in an adhesive made of resin. The micro-sized metal microparticles are, for example, metal in a flake state (silver or the like). The metal microparticles are not limited to silver, and may be gold, copper, or the like, or multiple types of metals. The adhesive contains, for example, an epoxy resin as the main component. The conductive paste is cured by heating, and is used, for example, to form a connection terminal to be connected to the wiring. The connection terminal is, for example, a bump connected to a component terminal of an electronic component, an external electrode connected to an external device, or the like.

Third molding unit <NUM> includes dispenser <NUM> as a device for applying a conductive paste. The device for applying the conductive paste is not limited to the dispenser, and may be a screen printing device or a gravure printing device. In addition, In the present disclosure, the term "applying" is a concept including an operation of discharging a fluid from a nozzle or the like, an operation of adhering a fluid on a target object by screen printing or gravure printing, an operation of applying a fluid with a pin, and the like. Dispenser <NUM> discharges the conductive paste on base material <NUM> or the resin layer. The discharged conductive paste is heated and cured by, for example, firing section <NUM> of first molding unit <NUM> to form a connection terminal (external electrode or the like).

Here, the conductive paste includes, for example, metal microparticles having a size of several tens of micrometers or less. The adhesive (resin or the like) is cured by heating, and the conductive paste is cured in a state where the metals in a flake state are in contact with each other. As described above, the conductive ink is, for example, metal integrated by fusing the metal nanoparticles by heating, and the conductivity is increased as compared with a state where the metal nanoparticles are merely in contact with each other. On the other hand, the conductive paste is cured by bringing micro-sized metal microparticles into contact with each other by curing an adhesive. Therefore, the resistance (electrical resistivity) of the wiring formed by curing the conductive ink is significantly low, for example, several to several tens of micro Ω·cm, and is lower than the resistance (several tens to several thousands of micro Ω·cm) of the wiring in which the conductive paste is cured. Accordingly, the conductive ink is suitable for molding a molded object requiring a low resistance value, such as circuit wiring having a low resistance.

On the other hand, the conductive paste can improve the adhesion with another member by curing the adhesive when curing, and is excellent in the adhesion with another member as compared with the conductive ink. Another member referred to herein is a member to which a conductive paste is adhered by discharging or the like, and is, for example, a resin layer, wiring, a component terminal of an electronic component, or the like. Accordingly, the conductive paste is suitable for molding a molded object requiring mechanical strength (tensile strength or the like), such as a connection terminal for fixing an electronic component to a resin layer. In mounting board manufacturing apparatus <NUM> of the present embodiment, a mounting board having improved electrical properties and mechanical properties can be manufactured by selectively using such a conductive ink and a conductive paste to utilize the characteristics.

Next, a configuration of control device <NUM> of mounting board manufacturing apparatus <NUM> will be described. As illustrated in <FIG> and <FIG>, control device <NUM> is provided with controller <NUM>, multiple drive circuits <NUM>, and storage device <NUM>. Multiple drive circuits <NUM> are connected to electromagnetic motors <NUM> and <NUM>, holding device <NUM>, lifting and lowering device <NUM>, ink jet head <NUM>, irradiation device <NUM>, ink jet head <NUM>, flattening device <NUM>, irradiation device <NUM>, tape feeder <NUM>, mounting head <NUM>, and moving device <NUM> (refer to <FIG>). Furthermore, drive circuit <NUM> is connected to third molding unit <NUM> (refer to <FIG>).

Controller <NUM> is provided with CPU, ROM, RAM, and the like, is mainly a computer, and is connected to multiple drive circuits <NUM>. Storage device <NUM> is provided with RAM, ROM, a hard disk, and the like, and stores control program <NUM> for controlling mounting board manufacturing apparatus <NUM>. Controller <NUM> can control the operations of conveyance device <NUM>, first molding unit <NUM>, second molding unit <NUM>, mounting unit <NUM>, third molding unit <NUM>, and the like by executing control program <NUM> with CPU. In the following description, the fact that controller <NUM> executes control program <NUM> to control each device may be simply referred to as a "device". For example, the fact that "controller <NUM> causes stage <NUM> to move" means that "controller <NUM> executes control program <NUM>, controls the operation of conveyance device <NUM> through drive circuit <NUM>, and causes stage <NUM> to move by the operation of conveyance device <NUM>".

Mounting board manufacturing apparatus <NUM> of the present embodiment manufactures molded object <NUM> (refer to <FIG>) in which multiple cured resin layers <NUM> are laminated by the above-described configuration. For example, in control program <NUM> of storage device <NUM>, three-dimensional data of each layer obtained by slicing molded object <NUM> at completion is set. Controller <NUM> controls first molding unit <NUM> and the like based on the data of control program <NUM> to discharge, cure, and the like ultraviolet curable resin <NUM> to form molded object <NUM>.

First, when base material <NUM> is set on base plate <NUM> of stage <NUM>, controller <NUM> molds molded object <NUM> on base material <NUM> while moving stage <NUM>. As illustrated in <FIG>, release film <NUM> which can be released by heat, for example, is adhered to the upper surface of base material <NUM>, and molded object <NUM> is formed on release film <NUM>. Release film <NUM> is released from base material <NUM> together with molded object <NUM> by heating. A method of separating base material <NUM> and molded object <NUM> is not limited to a method using release film <NUM>. For example, a member (support material or the like) that is melted by heat may be disposed between base material <NUM> and molded object <NUM>, and may be melted and separated. In addition, molded object <NUM> may be directly molded on base material <NUM> without using a separating member such as release film <NUM>.

When base material <NUM> is set, controller <NUM> forms cured resin layer <NUM> on release film <NUM> as illustrated in <FIG>. Controller <NUM> molds molded object <NUM> having a predetermined shape by laminating multiple cured resin layers <NUM>. For example, controller <NUM> discharges, cures, or the like ultraviolet curable resin <NUM> based on the three-dimensional data of control program <NUM> to form cured resin layer <NUM>.

<FIG> illustrates a step of manufacturing molded object <NUM>. First, as illustrated in step <NUM> in <FIG> (hereinafter, simply referred to as "S"), ink jet head <NUM> of second printing section <NUM> discharges droplets of ultraviolet curable resin <NUM> on release film <NUM>. Discharged ultraviolet curable resin <NUM> adheres on release film <NUM> and spreads in a thin film shape.

Next, as illustrated in S13, controller <NUM> rotates roller <NUM> of flattening device <NUM> in a state of being in contact with thin-film ultraviolet curable resin <NUM> to perform flattening. Roller <NUM> scrapes up ultraviolet curable resin <NUM> in a flowable state while rotating. Scraped ultraviolet curable resin <NUM> adheres to the surface of roller <NUM>, is scraped by a blade (not illustrated) of collection section <NUM>, and is collected in collection section <NUM>.

Next, as illustrated in S15, irradiation device <NUM> irradiates ultraviolet curable resin <NUM> on release film <NUM> with ultraviolet rays to semi-cure ultraviolet curable resin <NUM> to form cured resin layer <NUM> in the semi-cured state. Controller <NUM> repeatedly executes the processes of S11, S13, and S15 to laminate cured resin layer <NUM> in the semi-cured state. Controller <NUM> may not execute a flattening step S13 every time between a discharging step S11 and the semi-curing step S15.

The semi-cured state described above means, for example, a state where ultraviolet curable resin <NUM> is not completely stable at the level of physical properties, but in a case where ultraviolet curable resin <NUM> is discharged on cured resin layer <NUM> subjected to be semi-cured, ultraviolet curable resin <NUM> is cured to such an extent that discharged ultraviolet curable resin <NUM> is not mixed with cured resin layer <NUM> and can be laminated on cured resin layer <NUM> in the semi-cured state. In other words, ultraviolet curable resin <NUM> is cured to such an extent that cured resin layer <NUM> can be further laminated on cured resin layer <NUM> semi-cured. Controller <NUM> controls the intensity (intensity of light) of the ultraviolet rays irradiated from irradiation device <NUM> on ultraviolet curable resin <NUM>, the scanning speed at which the ultraviolet rays are scanned with respect to ultraviolet curable resin <NUM>, the number of times of scanning, and the like, thereby changing the light amount of ultraviolet rays to cause ultraviolet curable resin <NUM> to be in the semi-cured state. As a result, cured resin layer <NUM> in the semi-cured state can be laminated in the Z-axis direction.

Here, in the flattening step S13, when the transfer amount of ultraviolet curable resin <NUM> discharged on the surface of cured resin layer <NUM> to be transferred to roller <NUM> is small, it is not possible to sufficiently suppress the unevenness formed on the surface of cured resin layer <NUM> after the semi-curing. The fact that "suppressing the unevenness" as used herein means, for example, reducing the number of unevenness to be formed, reducing the difference in height of the unevenness, or the like.

<FIG> schematically illustrates a state of the flattening step by roller <NUM> in S13. Controller <NUM> of the present embodiment irradiates with ultraviolet rays from irradiation device <NUM> using the light amount in which first contact angle θ1 of ultraviolet curable resin <NUM> discharged on cured resin layer <NUM> in S11 with respect to cured resin layer <NUM> is larger than second contact angle θ2 of ultraviolet curable resin <NUM> with respect to roller <NUM> in S15.

Specifically, the applicant has investigated the relationship between the light amount of ultraviolet rays irradiated on ultraviolet curable resin <NUM> and first contact angle θ1. <FIG> illustrates the relationship between the integrated light amount with respect to ultraviolet curable resin <NUM> and first contact angle θ1. For example, the horizontal axis in <FIG> indicates the integrated light amount of ultraviolet rays irradiated on flattened thin-film ultraviolet curable resin <NUM> in the semi-curing step S15, and indicates that the integrated light amount increases in the right direction. The integrated light amount is an integration of the time during which the ultraviolet rays are irradiated per unit area and the intensity of light, and is, for example, Joules (J/cm<NUM>) per unit square centimeter. The integrated light amount indicates, for example, the integrated light amount of a specific wavelength band (several hundred nm) that acts on the curing of ultraviolet curable resin <NUM> among the wavelengths of light included in the ultraviolet rays. In addition, the vertical axis indicates first contact angle θ1, and indicates that the angle increases in the up direction, that is, the wettability decreases and it comes to be difficult to wet (easy to repel).

First contact angle θ1 can be calculated, for example, by the formulas illustrated in the following equations <NUM> and <NUM>. <MAT> herein, <MAT> <MAT>.

In the above equations, r is the outer diameter of the droplet of ultraviolet curable resin <NUM> discharged from ink jet head <NUM>, as illustrated in <FIG>. In addition, R is the outer diameter of ultraviolet curable resin <NUM> after being dropped on cured resin layer <NUM>. A method of calculating first contact angle θ1 is not limited to the method using the above mathematical expression. For example, first contact angle θ1 may be calculated by analyzing an image captured of ultraviolet curable resin <NUM> actually dropped.

Graph <NUM> indicated by solid lines in <FIG> illustrates a case where ultraviolet curable resin <NUM> containing a surface adjusting agent having a liquid-repellent function is used as ultraviolet curable resin <NUM>. As illustrated in graph <NUM>, in a case where ultraviolet curable resin <NUM> containing a material having a liquid-repellent property is used, first contact angle θ1 increases as the integrated light amount of ultraviolet rays irradiated in the semi-curing step S15 increases, and the state is saturated to a predetermined angle. As first contact angle θ1 increases, ultraviolet curable resin <NUM> discharged on cured resin layer <NUM> is easily repelled from cured resin layer <NUM>. Accordingly, next, when the flattening step S13 is executed, the transfer amount of ultraviolet curable resin <NUM> transferred from cured resin layer <NUM> to roller <NUM> can be increased.

<FIG> illustrates the relationship between the integrated light amount with respect to ultraviolet curable resin <NUM> and the size of the unevenness formed on the surface of cured resin layer <NUM> after the semi-curing. Similar to <FIG>, the horizontal axis in <FIG> indicates the integrated light amount of ultraviolet rays irradiated on flattened thin-film ultraviolet curable resin <NUM> in the semi-curing step S15, and indicates that the integrated light amount increases in the right direction. In addition, the vertical axis indicates a difference in height between the maximum value (most protruding position) and the minimum value (most recessed position) of the unevenness formed on the surface of cured resin layer <NUM>, and indicates that the difference in height of the unevenness is increased in the up direction, that is, the unevenness increases. An estimation method of the size of the unevenness is not particularly limited, but can be measured, for example, by observing the surface of cured resin layer <NUM> after being semi-cured with a laser microscope.

In the measurements of <FIG> and <FIG>, for example, the shape and material of roller <NUM>, the material of ultraviolet curable resin <NUM>, the amount of droplets of ultraviolet curable resin <NUM> to be discharged, and the like were made constant. That is, among the factors affecting the size of first contact angle θ1 and the formation of the unevenness, a factor other than the light amount of ultraviolet rays was fixed under a certain condition. As illustrated in <FIG> and <FIG>, for example, by setting the integrated light amount to be first reference light amount X1 or more, first contact angle θ1 can be made equal to or more than a certain angle, and the size of the unevenness formed on the surface of cured resin layer <NUM> can be suppressed to be equal to or less than a certain size. It is considered that this is because ultraviolet curable resin <NUM> is easily repelled on cured resin layer <NUM>, second contact angle θ2 is relatively reduced, and ultraviolet curable resin <NUM> is easily transferred from cured resin layer <NUM> to roller <NUM>. That is, it is considered that the transfer amount of ultraviolet curable resin <NUM> increased. The applicant confirmed that second contact angle θ2 is reduced by several degrees to ten and several or more as compared with first contact angle θ1 in a case where the ultraviolet rays are irradiated with first reference light amount X1. It was confirmed that the difference in the unevenness was reduced to approximately ten and several µm.

Accordingly, in the molding method of the present embodiment, in a case where ultraviolet curable resin <NUM> containing a material having a liquid-repellent property is used, it is preferable to set the integrated light amount to a predetermined first reference light amount X1 or more, so that first contact angle θ1 is larger than second contact angle θ2. In ultraviolet curable resin <NUM> containing a material having a liquid-repellent property, when the light amount in the semi-curing step S15 is increased, the contact angle of ultraviolet curable resin <NUM> with respect to cured resin layer <NUM>, that is, first contact angle θ1 tends to be increased (refer to graph <NUM> in <FIG>). Therefore, in a case where ultraviolet curable resin <NUM> containing a material having a liquid-repellent property is used, by setting the integrated light amount in the semi-curing step S15 to predetermined first reference light amount X1 or more, ultraviolet curable resin <NUM> can be made easier to repel from cured resin layer <NUM>, and the transfer amount can be further increased.

Although the method of changing the integrated light amount of ultraviolet rays irradiated in S15 is not limited, for example, the integrated light amount may be changed by changing at least one of the intensity of light, the scanning speed, or the number of scans. The intensity of light is the intensity of ultraviolet rays irradiated from irradiation device <NUM> in S15. In addition, the scanning speed is the speed at which the ultraviolet rays are scanned in a case where irradiation device <NUM> or base material <NUM> is moved to move the irradiation position of the ultraviolet rays, and the ultraviolet rays are scanned with respect to ultraviolet curable resin <NUM> in S15. In addition, the number of scans is the number of scans of the ultraviolet rays with respect to ultraviolet curable resin <NUM> in one step S15.

As a result, by changing the intensity of light, the scanning speed, and the number of scans, the integrated light amount with respect to ultraviolet curable resin <NUM> can be adjusted to perform flattening. In particular, by changing only the intensity of light, it is possible to make the execution time of the semi-curing step S15 more uniform as compared with the case where the scanning speed or the number of scans is changed. This is because in a case where the scanning speed or the number of scans is changed, the work time for irradiating ultraviolet curable resin <NUM> with the ultraviolet rays from irradiation device <NUM> changes. In other words, by changing only the intensity of light, it is possible to suppress change in the takt time of the manufacturing step including the semi-curing step.

On the other hand, graph <NUM> indicated by dashed lines in <FIG> illustrates a case where ultraviolet curable resin <NUM> not containing a surface adjusting agent having a liquid-repellent function is used as ultraviolet curable resin <NUM>. As illustrated in graph <NUM>, in a case where ultraviolet curable resin <NUM> not containing a material having a liquid-repellent property is used, first contact angle θ1 tends to decrease as the integrated light amount of ultraviolet rays irradiated in the semi-curing step is increased, contrary to graph <NUM> (with the material having a liquid-repellent property).

Accordingly, in ultraviolet curable resin <NUM> not containing a material having a liquid-repellent property, the more the curing proceeds, the smaller first contact angle θ1 of ultraviolet curable resin <NUM> with respect to cured resin layer <NUM>. In a case where ultraviolet curable resin <NUM> not containing a material having a liquid-repellent property is used, for example, it is preferable to irradiate with ultraviolet rays having an integrated light amount equal to or less than second reference light amount X2. As a result, by setting the integrated light amount in the semi-curing step to be predetermined second reference light amount X2 or less, it is possible to suppress the decrease of first contact angle θ1 and increase the transfer amount.

In addition, in the semi-curing step S15 in <FIG>, cured resin layer <NUM> in the semi-cured state is formed without completely curing ultraviolet curable resin <NUM>. As a result, for example, in a case where ultraviolet curable resin <NUM> is discharged on cured resin layer <NUM> subjected to be semi-cured, cured resin layer <NUM> is semi-cured to such an extent that discharged ultraviolet curable resin <NUM> is not mixed with cured resin layer <NUM> and ultraviolet curable resin <NUM> can be laminated on cured resin layer <NUM> in the semi-cured state. As a result, cured resin layer <NUM> in the semi-cured state can be laminated. On the other hand, when ultraviolet curable resin <NUM> is completely cured until the physical properties are stabilized, the execution time of one step illustrated in S15 (irradiation time of ultraviolet rays or the like) increases, resulting in a delay in the manufacturing time of molded object <NUM>. On the other hand, in the molding method, the execution time of step S15 can be shortened by semi-curing to an extent that can be laminated. By finally and completely curing laminated cured resin layer <NUM>, it is possible to shorten the manufacturing time of molded object <NUM> while achieving flattening.

As illustrated in <FIG>, controller <NUM> repeatedly executes the steps S <NUM>, S13, and S15, laminates cured resin layer <NUM> in the semi-cured state, and then executes the main curing step of completely curing the laminated cured resin layer <NUM> (S <NUM>). Controller <NUM> increases the integrated light amount as compared with S15 to execute the curing of cured resin layer <NUM>. For example, controller <NUM> causes the intensity of the ultraviolet rays of S17 larger than the intensity of the ultraviolet rays of S15. As a result, it is possible to mold molded object <NUM> that is completely stable at the level of physical properties and cured to such an extent that the droplets of ultraviolet curable resin <NUM> do not mix. As described above, the transfer amount of S13 is increased, cured resin layer <NUM> having a small unevenness on the surface can be laminated, and cured resin layer <NUM> can be laminated with high accuracy. In addition, the unevenness of the surface of final molded object <NUM> can be reduced to, for example, approximately ten and several µm. The semi-curing step S15 immediately before the main curing step S17 is executed may be omitted. That is, last S15 may be included in S17 and executed.

The structure, manufacturing procedure, and the like of molded object <NUM> described above are examples. In the following description, as another example of molded object <NUM>, a case where wirings or the like are formed on a surface flattened by roller <NUM> will be described. <FIG> illustrates an example of a manufacturing step after that of <FIG>. As illustrated in <FIG>, for example, after executing the flattening step S13, controller <NUM> executes the semi-curing step S15 or the main curing step S17.

Here, as illustrated in S15 (or S17) in <FIG>, on upper surface 149A of cured resin layer <NUM> semi-cured, there is a possibility that uneven portions 149B caused by the curved surface shape of the droplets are formed. The difference in the height of uneven portions 149B may be, for example, the size less than several tens (or <NUM>) µm, and there is a limit to the transfer of the liquid by roller <NUM> alone. Therefore, even when cured resin layer <NUM> flattened by adjusting the integrated light amount of ultraviolet rays is laminated, it may be difficult to flatten the surface of final molded object <NUM> (refer to <FIG>) to a fine unevenness.

Therefore, as illustrated in S19, controller <NUM> discharges ultraviolet curable resin <NUM> from ink jet head <NUM> on upper surface 149A of cured resin layer <NUM> semi-cured in S15 or mainly cured in S17. Ultraviolet curable resin <NUM> discharged on upper surface 149A of cured resin layer <NUM> forms a thin film layer spread in a thin film shape on upper surface 149A. The thin film layer is formed, for example, by setting a minimum discharge amount at which ultraviolet curable resin <NUM> can be discharged by ink jet head <NUM> in the discharging step S19, and scanning upper surface 149A only once. For example, the thin film layer is preferably the thinnest thickness that can be formed in ink jet head <NUM>. Ultraviolet curable resin <NUM> spread in a thin film shape adheres to upper surface 149A and then enters uneven portion 149B.

Next, as illustrated in S21, controller <NUM> irradiates toward upper surface 149A from which ultraviolet curable resin <NUM> is discharged with ultraviolet rays by irradiation device <NUM>, and discharged ultraviolet curable resin <NUM> is semi-cured. The semi-cured state in S21 is a semi-cured state having higher fluidity than the semi-cured state in S15 described above. For example, the semi-cured state of S19 is a gel-like state where the viscosity is increased from the state of droplets at discharging to fluid. Controller <NUM> reduces, for example, the intensity, the number of scans, the scanning speed, the scanning time, and the like of the ultraviolet rays irradiated on ultraviolet curable resin <NUM> as compared with S15, thereby causing ultraviolet curable resin <NUM> to be in a semi-cured state where the fluidity is enhanced than the state of S15.

Ultraviolet curable resin <NUM> enters uneven portion 149B while changing the viscosity by irradiating with ultraviolet rays. Controller <NUM> repeatedly executes the steps S19 and S21. As a result, ultraviolet curable resin <NUM> spreads so as to close uneven portion 149B to be semi-cured. On upper surface 149A, smooth surface 149C that is flatter than the surface of molded object <NUM> formed in S11, S13, S15, and S17 is formed. The applicant has confirmed that by forming smooth surface 149C, the height of the unevenness of upper surface 149A of cured resin layer <NUM> is improved to several µm. By forming such smooth surface 149C, wirings having a more uniform thickness can be formed on cured resin layer <NUM>.

For example, as illustrated in S23, controller <NUM> causes the integrated light amount larger than that of S21 to mainly cure cured resin layer <NUM> having smooth surface 149C. Next, as illustrated in S25, wiring <NUM> is formed on smooth surface 149C cured in S23. Controller <NUM> forms wiring <NUM> having a desired wiring pattern, for example, by discharging conductive ink from ink jet head <NUM> (refer to <FIG>) of first molding unit <NUM> to smooth surface 149C, and curing the conductive ink by irradiation device <NUM>.

Accordingly, controller <NUM> repeatedly executes steps S11, S13, and S15, and executes step S19 of discharging ultraviolet curable resin <NUM> on laminated cured resin layer <NUM>. Next, controller <NUM> executes step S21 of irradiating ultraviolet curable resin <NUM> discharged in S19 with light having the light amount smaller than the light amount of the semi-curing step S15 to cure ultraviolet curable resin <NUM> without being flattened by roller <NUM>, and forming smooth surface 149C on cured resin layer <NUM>.

As described above, fine uneven portions 149B that cannot be eliminated by roller <NUM> may be formed on upper surface 149A flattened by roller <NUM>. Therefore, ultraviolet curable resin <NUM> is discharged on cured resin layer <NUM>, and discharged ultraviolet curable resin <NUM> is cured without being flattened. In addition, ultraviolet curable resin <NUM> is semi-cured by irradiating with light having the light amount smaller than the light amount of S15. As a result, ultraviolet curable resin <NUM> discharged on cured resin layer <NUM> enters fine uneven portion 149B formed on upper surface 149A of cured resin layer <NUM> by the leveling effect, spreads and is smoothed (fills uneven portion 149B), and forms, for example, smooth surface 149C having a surface unevenness of ±<NUM> or less. It is possible to further suppress the unevenness of the surface of cured resin layer <NUM>. Therefore, the light amount smaller than the light amount of S15 described above is, for example, not the light amount that is semi-cured to the extent that the cured resin layer <NUM> semi-cured such as S15 can be laminated, and is the light amount such that the droplets of cured resin layer <NUM> discharged onto cured resin layer <NUM> can enter (mix) uneven portion 149B of cured resin layer <NUM> and exert a leveling effect.

Controller <NUM> executes a step of discharging conductive ink on smooth surface 149C, and a step of curing the discharged conductive ink to form wiring <NUM> on smooth surface 149C (S25). When the unevenness occurs on cured resin layer <NUM>, in a case where wiring <NUM> is formed on cured resin layer <NUM> by a three-dimensional lamination molding method, there is a possibility that the thickness of wiring <NUM> may be uneven or wiring <NUM> may be disconnected. In other words, a connection failure occurs. On the other hand, by discharging conductive ink on smooth surface 149C formed on cured resin layer <NUM> and curing the conductive ink, it is possible to form wiring <NUM> having a more uniform thickness (having higher electrical characteristics) on the cured resin layer.

Furthermore, as illustrated in S25, controller <NUM> may form bump <NUM> on wiring <NUM> to mount electronic component <NUM>. Specifically, after forming wiring <NUM>, controller <NUM> controls third molding unit <NUM> to discharge the conductive paste on wiring <NUM> by dispenser <NUM>. Controller <NUM> discharges the conductive paste in accordance with a position connected to component terminal <NUM> of wiring <NUM> (position of bump <NUM>).

Next, controller <NUM> moves stage <NUM> below mounting unit <NUM>, and mounts electronic component <NUM> by mounting section <NUM>. Mounting head <NUM> (refer to <FIG>) of mounting section <NUM> picks up and holds electronic component <NUM> by the suction nozzle, and disposes component terminal <NUM> of electronic component <NUM> so as to be located at the positions of the conductive paste. Controller <NUM> heats and cures the conductive paste by firing section <NUM> of first molding unit <NUM> to form bump <NUM>. As a result, component terminal <NUM> of electronic component <NUM> is electrically connected to wiring <NUM> via bump <NUM>. In this manner, mounting board manufacturing apparatus <NUM> of the present embodiment can execute flattening and smoothing upper surface 149A of cured resin layer <NUM>, and can manufacture a mounting board on which electronic component <NUM> is mounted on smooth surface 149C.

Incidentally, in the above example, ultraviolet curable resin <NUM> is an example of a resin material. Step of S11 is an example of a discharging step. Step of S13 is an example of a flattening step. Step of S15 is an example of a curing step. Step of S19 is an example of a second discharging step. Step of S21 is an example of a second curing step. Step of S25 is an example of a third discharging step and a third curing step.

Hereinbefore, according to the present embodiment described above, the following effects are obtained. The molding method of the present embodiment includes the step S11 of discharging ultraviolet curable resin <NUM> on cured resin layer <NUM>, and the step S13 of transferring a part of ultraviolet curable resin <NUM> discharged in S11 from cured resin layer <NUM> to roller <NUM> to flatten ultraviolet curable resin <NUM>. In addition, the molding method includes the step S15 of irradiating ultraviolet curable resin <NUM> flattened in S13 with ultraviolet rays having a predetermined integrated light amount to cure ultraviolet curable resin <NUM>, and forming new cured resin layer <NUM> on cured resin layer <NUM>, and repeatedly executes S11, S13, and S15 to laminate cured resin layer <NUM>. In S15, controller <NUM> uses an integrated light amount in which first contact angle θ1 of ultraviolet curable resin <NUM> with respect to cured resin layer <NUM> is larger than second contact angle θ2 of ultraviolet curable resin <NUM> with respect to roller <NUM>.

As a result, by making first contact angle θ1 of cured resin layer <NUM> relatively larger than second contact angle θ2 of roller <NUM>, ultraviolet curable resin <NUM> is easily repelled from cured resin layer <NUM>, and is easily transferred to roller <NUM>. Accordingly, by adjusting the integrated light amount in S15, the amount of transfer to roller <NUM> in S13 can be increased, and ultraviolet curable resin <NUM> can be further flattened by using roller <NUM>. It is possible to suppress the unevenness of upper surface 149A of cured resin layer <NUM>. The fact that "suppressing the unevenness" means, for example, reducing the number of unevenness, reducing the difference in height of the unevenness, or the like.

The present disclosure is not limited to the above-described examples, but can be performed in various forms in which various modifications and improvements are made based on the knowledge of those skilled in the art. For example, in the above example, the ultraviolet curable resin cured by irradiation with ultraviolet rays is adopted as the resin material of the present disclosure, but the present disclosure is not limited thereto. For example, the resin material can adopt various curable resins such as a thermosetting resin cured by heat. In this case, in a case where the thermosetting resin is heated by an infrared heater or the like, flattening can be achieved by adjusting the light amount (infrared light or the like) irradiated from a heat source to be heated in the same manner as ultraviolet rays. In addition, the light amount in the present disclosure is not limited to the integrated light amount per unit area, but may be the light amount irradiated to ultraviolet curable resin <NUM> per unit time in step S15. In addition, controller <NUM> may not execute the manufacturing step in <FIG>. Accordingly, controller <NUM> may not form wiring <NUM> or the like on cured resin layer <NUM> and may not mount electronic component <NUM>. In addition, the three-dimensional lamination molding method in the present disclosure is not limited to an ink jet method or a stereo lithography method (SL), and other methods such as, for example, a fused deposition molding (FDM) method can be employed.

Claim 1:
A molding method comprising:
a discharging step (S11) of discharging a resin material (<NUM>) on a cured resin layer (<NUM>);
a flattening step (S13) of transferring a part of the resin material (<NUM>) discharged by the discharging step (S11) from the cured resin layer (<NUM>) to a roller (<NUM>) to flatten the resin material (<NUM>); and
a curing step (S15) of irradiating the resin material (<NUM>) flattened by the flattening step (S13) with light having a predetermined light amount to cure the resin material (<NUM>), and forming a new cured resin layer (<NUM>) on the cured resin layer (<NUM>),
wherein
the discharging step (S11), the flattening step (S13), and the curing step (S15) are repeatedly executed, and the cured resin layer (<NUM>) is laminated, and
characterized in that
the light amount is used in which a first contact angle (θ1) of the resin material (<NUM>) with respect to the cured resin layer (<NUM>) is larger than a second contact angle (θ2) of the resin material (<NUM>) with respect to the roller (<NUM>).