Patent Description:
As disclosed in the Patent Literature below, in a general printed substrate, a solder resist is formed on an upper surface of a base composed of an insulating layer and a conductor layer.

For example, the solder resist is formed on the upper surface of the base, such as an inner layer circuit board or the like, with using a mask, but even when only a part of the circuit pattern needs to be changed, a new mask is required for being made, which is not practical manner. Therefore, it is an object to provide a printed substrate forming method and the like with high practicality.

<CIT> discloses a method to form a printed substrate.

The invention is defined by the features of claims <NUM> and <NUM>. In order to solve the problems described above, the present description discloses a printed substrate forming method according to claim <NUM>.

In addition, in order to solve the above-described problems, the present description discloses a printed circuit board forming device according to claim <NUM>.

According to the present disclosure, a part of the printed substrate is formed of, for example, curable resin discharged by an inkjet head or the like. In this way, it is possible to change a part of the printed substrate easily, and thus, the practicality is improved.

<FIG> and <FIG> illustrate circuit forming system <NUM>. Circuit forming system <NUM> is configured with custom section forming device <NUM> illustrated in <FIG> and general-purpose section forming device <NUM> illustrated in <FIG>.

Custom section forming device <NUM> is a so-called 3D printer, and includes conveyance device <NUM>, first shaping unit <NUM>, second shaping unit <NUM>, mounting unit <NUM>, and control device (refer to <FIG>) <NUM>. Conveyance device <NUM>, first shaping unit <NUM>, second shaping unit <NUM>, and mounting unit <NUM> are arranged on base <NUM> of custom section forming device <NUM>. Base <NUM> has a substantially rectangular shape, and in the following description, the longitudinal direction of base <NUM> will be referred to as the X-axis direction, the lateral direction of base <NUM> will be referred to as the Y-axis direction, and the direction orthogonal to both the X-axis direction and the Y-axis direction will be referred to as the Z-axis direction.

Conveyance device <NUM> includes 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 on base <NUM> so as to extend in the X-axis direction. X-axis slider <NUM> is held by X-axis slide rail <NUM> so as to be slidable in the X-axis direction. Furthermore, X-axis slide mechanism <NUM> includes electromagnetic motor (refer to <FIG>) <NUM>, and by driving electromagnetic motor <NUM>, X-axis slider <NUM> moves to any position in the X-axis direction. Y-axis slide mechanism <NUM> includes Y-axis slide rail <NUM> and stage <NUM>. Y-axis slide rail <NUM> is disposed on base <NUM> so as to extend in the Y-axis direction and is movable in the X-axis direction. One end of Y-axis slide rail <NUM> is coupled to X-axis slider <NUM>. On Y-axis slide rail <NUM>, stage <NUM> is held so as to be slidable in the Y-axis direction. Furthermore, Y-axis slide mechanism <NUM> includes electromagnetic motor (refer to <FIG>) <NUM>, and by driving electromagnetic motor <NUM>, stage <NUM> moves to any position in the Y-axis direction. 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 on a flat plate shape, and the printed substrate is placed on the upper surface. Holding devices <NUM> are provided on both sides of base plate <NUM> in the X-axis direction. Both edges of the printed substrate in the X-axis direction placed on base plate <NUM> are pinched by holding device <NUM>, the printed substrate is fixedly held. In addition, lifting and lowering device <NUM> is disposed below base plate <NUM>, and lifts and lowers base plate <NUM>.

First shaping unit <NUM> is a unit for shaping a wiring on the printed substrate placed on base plate <NUM> of stage <NUM>, and includes first printing section <NUM> and firing section <NUM>. First printing section <NUM> includes inkjet head (refer to <FIG>) <NUM>, and inkjet head <NUM> discharges metal ink in a line shape. The metal ink is ink in which fine metal particles are dispersed in a solvent. Inkjet head <NUM> discharges the metal ink from multiple nozzles by a piezo type using a piezoelectric element, for example.

Firing section <NUM> includes laser irradiation device (refer to <FIG>) <NUM>. Laser irradiation device <NUM> is a device for causing the discharged metal ink to be irradiated with laser, and the metal ink irradiated with the laser is fired to form the wiring. Firing of the metal ink is a phenomenon in which conductivity is increased by vaporizing solvent or decomposing a metal fine particle protective film by applying energy and contacting or fusing the metal fine particles. Then, by the metal ink being fired, the metal wiring is formed. In addition, the ink firing may be performed by a collective heating method at a temperature at which necessary energy can be applied without using a laser.

In addition, second shaping unit <NUM> is a unit for shaping a resin layer on the printed substrate placed on base plate <NUM> of stage <NUM>, and includes second printing section <NUM>, discharge section <NUM>, and curing section <NUM>. The second printing section <NUM> includes inkjet head (refer to <FIG>) <NUM>, and inkjet head <NUM> discharges UV curable resin. The UV curable resin is resin that is cured by being irradiated with the ultraviolet rays. The inkjet head <NUM> may be, for example, a piezo type using the piezoelectric element, or may be a thermal type in which the resin is heated to generate bubbles which is discharged from multiple nozzles.

Discharge section <NUM> includes dispense head (refer to <FIG>) <NUM>, and dispense head <NUM> discharges the conductive UV curable resin. The conductive UV curable resin is the resin on which the metal fine particles are dispersed on the resin cured by being irradiated with the ultraviolet rays. Then, the resin is cured and shrinks by being irradiated with the ultraviolet rays, the metal fine particles are brought into close contact with each other, and the conductive UV curable resin exhibits the conductivity. Since a viscosity of the conductive UV curable resin is relatively high compared to that of the metal ink, dispense head <NUM> discharges the conductive UV curable resin from one nozzle having a diameter larger than the diameter of the nozzle of inkjet head <NUM>. Dispense head <NUM> may be, for example, a transfer head that performs a paste-transfer with a stamp, and the conductive UV curable resin may be, for example, conductive thermosetting resin.

Curing section <NUM> includes flattening device (refer to <FIG>) <NUM> and irradiation device (refer to <FIG>) <NUM>. Flattening device <NUM> is for flattening the upper surface of the UV curable resin discharged by inkjet head <NUM>, and for example, by scraping off the excess resin with a roller or a blade while leveling the top surface of the UV curable resin, a thickness of the UV curable resin is uniformed. In addition, irradiation device <NUM> includes a mercury lamp or an LED as a light source, and causes the discharged UV curable resin or the conductive UV curable resin to be irradiated with the ultraviolet rays. In this way, the discharged UV curable resin is cured to form the resin layer, and the conductive UV curable resin is cured to form the wiring.

Mounting unit <NUM> is a unit for mounting the electronic components on the printed substrate placed on base plate <NUM> of stage <NUM>, and includes supply section <NUM> and mounting section <NUM>. Supply section <NUM> includes multiple tape feeders (refer to <FIG>) <NUM> for feeding the taped electronic components one by one, and supplies the electronic components to the supply position. Not limited to tape feeder <NUM>, supply section <NUM> may be a tray-type supply device that picks up and supplies the electronic components from the tray. Furthermore, supply section <NUM> may be configured to include both the tape type and the tray type, or other type of supply device.

Mounting section <NUM> includes mounting head (refer to <FIG>) <NUM> and movement device (refer to <FIG>) <NUM>. Mounting head <NUM> includes a suction nozzle (not illustrated) for picking up and holding the electronic component. The suction nozzle is supplied with a negative pressure from a positive and negative pressure supply device (not illustrated), and then, picks up and holds the electronic component by suction of air. Then, by a slight positive pressure being supplied from the positive and negative pressure supply device, the electronic component is separated. In addition, movement device <NUM> moves mounting head <NUM> between the supply position of the electronic component by tape feeder <NUM> and the printed substrate placed on base plate <NUM>. As a result, in mounting section <NUM>, the electronic component supplied from tape feeder <NUM> is held by the suction nozzle, and the electronic component held by the suction nozzle is mounted on the printed substrate.

As illustrated in <FIG>, control device <NUM> includes controller <NUM> and multiple drive circuits <NUM>. Multiple drive circuits <NUM> are respectively connected to electromagnetic motors <NUM> and <NUM>, holding device <NUM>, lifting and lowering device <NUM>, inkjet head <NUM>, laser irradiation device <NUM>, inkjet head <NUM>, dispense head <NUM>, flattening device <NUM>, irradiation device <NUM>, tape feeder <NUM>, mounting head <NUM>, and movement device <NUM>. Controller <NUM> includes a CPU, a ROM, a RAM, and the like and is mainly a computer, and is connected to multiple drive circuits <NUM>. As a result, the operations of conveyance device <NUM>, first shaping unit <NUM>, second shaping unit <NUM>, and mounting unit <NUM> are controlled by controller <NUM>.

In addition, general-purpose section forming device <NUM> is a general printed substrate manufacturing device, and includes inner layer plate forming unit <NUM>, solder resist forming unit <NUM>, rust prevention unit <NUM>, solder printing unit <NUM>, mounting unit <NUM>, heating unit <NUM>, and conveyor device <NUM> as illustrated in <FIG>.

Inner layer plate forming unit <NUM> is a unit that forms inner layer plate (refer to <FIG>) <NUM>, and forms inner layer plate <NUM> using a pressure-boding device (not illustrated), a photosensitive device (not illustrated), a surface treatment device (not illustrated), and the like. Specifically, for example, in an inner layer pattern forming method of a subtract method, a copper foil is pressure-bonded to insulating layer (refer to <FIG>) <NUM> such as an interlayer material or a prepreg by the pressure-boding device. At this time, since an unevenness is formed on the pressure-bonded surface of the copper foil, an unevenness is formed on the pressure-bonded surface of insulating layer <NUM>. Then, a photosensitive mask resist on the copper foil is exposed by the photosensitive device in accordance with the wiring pattern and developed. Subsequently, the unnecessary copper foil is etched. As a result, inner layer plate <NUM> configured to include insulating layer <NUM> and copper pattern (refer to <FIG>) <NUM> is formed.

In addition, for example, in a semi-additive inner layer pattern forming method, unevenness is formed on a top surface of insulating layer <NUM> by a surface treatment device. As a method of forming the unevenness on the top surface of insulating layer <NUM>, there is a method in which the surface of insulating layer <NUM> is chemically roughened with potassium permanganate or the like to form the unevenness, or a method in which the top surface of insulating layer <NUM> is physically roughened by blasting or the like to form the unevenness. Then, by an electroless plating process, a copper thin film is formed on the surface of insulating layer <NUM> on which the unevenness is formed. Furthermore, a plating resist is formed on the top surface of the copper thin film along the wiring pattern, and then, electrolytic plating process is performed. As a result, the copper plating is deposited on the places where the plating resist is not formed. Then, by removing the plating resist and etching the copper thin film, inner layer plate <NUM> composed of insulating layer <NUM> and copper pattern <NUM> is formed.

In addition, solder resist forming unit <NUM> is a unit that forms solder resist (refer to <FIG>) <NUM> on the top surface of inner layer plate <NUM>, and forms solder resist <NUM> by a printing device (not illustrated), the irradiation device (not illustrated), or the like. Specifically, an exposure mask (not illustrated) is brought into close contact with the top surface of inner layer plate <NUM>, and the UV curable resin is printed on the exposure mask by the printing device. A through-hole is formed on the exposure mask so that a portion of copper pattern <NUM> other than pad (refer to <FIG>) <NUM> is exposed, the UV curable resin is irradiated with ultraviolet rays by the irradiation device through the exposure mask so that the UV curable resin is cured, and in the subsequent development step, the unexposed solder resist on pad <NUM> is dissolved, so that solder resist <NUM> is formed on the top surface of inner layer plate <NUM> in a state where pad <NUM> exposed. When a positive solder resist is used, the mask design of the exposed part and the unexposed part is negative-positive reversed.

In addition, rust prevention unit <NUM> is a unit for preventing the rust on pad <NUM> of copper pattern <NUM>, and prevent the rust on pad <NUM> with a palladium removing device (not illustrated), a plating device (not illustrated), or the like. Specifically, first, a palladium removing process is performed on the top surface of inner layer plate <NUM> on which solder resist <NUM> is formed. This is because the metal catalyst used in the pre-process remains on the top surface of inner layer plate <NUM>. Then, after the palladium removing process, inner layer plate <NUM> having solder resist <NUM> formed thereon is subjected to the electroless nickel-gold plating process in the plating device. As a result, pad <NUM> is covered with nickel-gold plating (refer to <FIG>) <NUM>.

In addition, solder printing unit <NUM> is a unit that prints solder on the opening of solder resist <NUM>, that is, pad <NUM> exposed from solder resist <NUM>, and the solder is printed on pad <NUM> by the printing device (not illustrated). Specifically, a solder mask (not illustrated) is brought into close contact with the top surface of solder resist <NUM>, and the solder paste is printed on the solder mask by a printing device. The through-hole is formed on the solder mask so that pad <NUM> of copper pattern <NUM> is exposed, and solder paste (refer to <FIG>) <NUM> is printed on the upper surface of pad <NUM> covered with nickel-gold plating <NUM>.

Mounting unit <NUM> is a unit for mounting electronic components (refer to <FIG>) <NUM> on the upper surface of solder resist <NUM>, and mounts electronic components <NUM> using a tape feeder (not illustrated), a mounting head (not illustrated), and a movement device (not illustrated). Specifically, the tape feeder, the mounting head, and the movement device included in mounting unit <NUM> are the same as tape feeder <NUM>, mounting head <NUM>, and movement device <NUM> included in mounting unit <NUM> of custom section forming device <NUM>. Therefore, in mounting unit <NUM>, electronic component <NUM> supplied from the tape feeder is held by the suction nozzle, and electronic component <NUM> held by the suction nozzle is mounted on the upper surface of solder resist <NUM>. At this time, electronic component <NUM> is mounted on the upper surface of solder resist <NUM> so that electrode <NUM> of electronic component <NUM> comes in contact with solder paste <NUM> discharged on the upper surface of pad <NUM>.

Heating unit <NUM> is a unit for heating solder paste <NUM>, and solder paste <NUM> is heated by a reflow furnace or the like. As a result, electronic component <NUM> is fixedly mounted on the upper surface of solder resist <NUM> in a state of being electrically connected to copper pattern <NUM> of inner layer plate <NUM>.

Conveyor device <NUM> is a device that conveys the printed substrate in an order of inner layer plate forming unit <NUM>, solder resist forming unit <NUM>, rust prevention unit <NUM>, solder printing unit <NUM>, mounting unit <NUM>, and heating unit <NUM>. As a result, the printed substrate is manufactured by the work in each unit.

In circuit forming system <NUM>, by the above-described configuration, in a predetermined region (hereinafter, referred to as a "general-purpose region"), a printed substrate forming step is performed by general-purpose section forming device <NUM>. In addition, in a region different from the general-purpose region (hereinafter referred to as a "custom region"), the printed substrate forming step is performed by custom section forming device <NUM>.

Specifically, first, in inner layer plate forming unit <NUM> of general-purpose section forming device <NUM>, inner layer plate <NUM> illustrated in <FIG> is formed. Next, formed onner layer plate <NUM> is conveyed into solder resist forming unit <NUM> by conveyor device <NUM>. Then, in solder resist forming unit <NUM>, as illustrated in <FIG>, solder resist <NUM> is formed only on general-purpose region <NUM> of inner layer plate <NUM>. In the exposure mask used when forming the solder resist, the through-hole is not formed on the portion covering custom region <NUM>, and the resin for the solder resist is not exposed in custom region <NUM>. When a positive solder resist is used, the mask design of the exposed part and the unexposed part is negative-positive reversed.

Subsequently, when solder resist <NUM> is formed, inner layer plate <NUM> is conveyed into rust prevention unit <NUM> by conveyor device <NUM>. Then, in rust prevention unit <NUM>, the nickel-gold plating process is performed after the palladium removing process is performed. As a result, as illustrated in <FIG>, in general-purpose region <NUM>, pad <NUM> exposed from solder resist <NUM> is covered with nickel-gold plating <NUM>. In addition, in custom region <NUM> also, pad <NUM> exposed from insulating layer <NUM> is covered with nickel-gold plating <NUM>.

Next, when pad <NUM> is covered with nickel-gold plating <NUM>, inner layer plate <NUM> is conveyed into solder printing unit <NUM> by conveyor device <NUM>. Then, as illustrated in <FIG>, in solder printing unit <NUM>, solder paste <NUM> is printed on the opening of solder resist <NUM> formed on general-purpose region <NUM>, that is, the upper surface of pad <NUM> exposed from solder resist <NUM>. In the solder mask used for printing the solder paste, the through-hole is not formed on the portion covering custom region <NUM>, and solder paste <NUM> is not printed in custom region <NUM>.

Subsequently, when the printing of solder paste <NUM> is completed, inner layer plate <NUM> on which solder paste <NUM> is printed is taken out from general-purpose section forming device <NUM>. Then, in custom section forming device <NUM>, inner layer plate <NUM> is set on base plate <NUM> of stage <NUM>, and stage <NUM> is moved below second shaping unit <NUM>. In second shaping unit <NUM>, as illustrated in <FIG>, resin layer <NUM> is formed on the upper surface of inner layer plate <NUM> in custom region <NUM>. The resin layer <NUM> includes opening <NUM> for exposing pad <NUM> of inner layer plate <NUM>, and is formed by repeatedly performing the discharging of the UV curable resin from inkjet head <NUM> and the discharged UV curable resin being irradiated with the ultraviolet rays emitted by irradiation device <NUM>.

Specifically, in second printing section <NUM> of second shaping unit <NUM>, inkjet head <NUM> discharges the UV curable resin in a thin film shape on the upper surface of inner layer plate <NUM> in custom region <NUM>. At this time, inkjet head <NUM> discharges the UV curable resin so that the upper surface of pad <NUM> of inner layer plate <NUM> is exposed. Subsequently, when the UV curable resin is discharged in a thin film shape, in curing section <NUM>, irradiation device <NUM> causes the thin film shaped UV curable resin to be irradiated with the ultraviolet rays. As a result, thin film <NUM> is formed on the upper surface of inner layer plate <NUM>.

Subsequently, inkjet head <NUM> discharges the UV curable resin only in the upper portion of thin film <NUM> in a thin film shape. That is, inkjet head <NUM> discharges the UV curable resin on thin film <NUM> in a thin film shape so that pad <NUM> of inner layer plate <NUM> is exposed. Then, by the UV curable resin discharged in the thin film shape is irradiated with the ultraviolet rays by irradiation device <NUM>, thin film <NUM> is laminated on thin film <NUM>. In this way, by repeatedly performing the discharging of the UV curable resin on thin film <NUM> excluding pad <NUM> and the irradiation with the ultraviolet rays, and the multiple thin films <NUM> are laminated, resin layer <NUM> having opening <NUM> is formed. When the thin films are laminated, the UV curable resin discharged on thin films <NUM> slightly flows into openings <NUM>. Therefore, an inner wall surface that defines opening <NUM> is an inclined surface.

By the way, when thin film <NUM> on the upper end surface of resin layer <NUM> is formed, thin film <NUM> becomes a flat surface by flattening device <NUM>. Specifically, when forming thin film <NUM> on the upper end surface of resin layer <NUM>, when inkjet head <NUM> discharges the UV curable resin in the thin film shape, the UV curable resin is flattened by flattening device <NUM> so that the discharged UV curable resin has a uniform film thickness. Then, the flattened UV curable resin is irradiated with ultraviolet rays by irradiation device <NUM>. As a result, the upper end surface of resin layer <NUM> becomes a flat surface.

In flattening device <NUM>, the UV curable resin is flattened by rollers or the like, however, when the flattened UV curable resin is positioned below the maximum height in general-purpose region <NUM>, the rollers or the like and the upper end part of general-purpose region <NUM> interfere with each other. Therefore, resin layer <NUM> is formed such that the upper end surface of resin layer <NUM> is higher than the maximum height in general-purpose region <NUM> when resin layer <NUM> is formed. That is, resin layer <NUM> is formed such that the upper end surface of resin layer <NUM> is higher than the upper end surface of solder paste <NUM> of general-purpose region <NUM>. In this way, a proper operation of the roller can be ensured.

Next, when resin layer <NUM> is formed, stage <NUM> is moved below first shaping unit <NUM>. Then, in first printing section <NUM>, inkjet head <NUM> discharges the metal ink in a line shape to the inner part of opening <NUM> of resin layer <NUM>, that is, from pad <NUM> exposed to opening <NUM> up to upper surface of opening <NUM> via the inner wall surface of opening <NUM>. Next, in firing section <NUM>, laser irradiation device <NUM> irradiates the metal ink with laser light. At this time, the energy of the laser light is absorbed by the metal ink, and thus, the metal ink generates heat and is fired. As a result, as illustrated in <FIG>, wiring <NUM> is formed from pad <NUM> exposed to opening <NUM> up to the upper surface of opening <NUM> via the inner wall surface of opening <NUM>. In addition, the ink fire may be performed by a collective heating method at a temperature at which necessary energy can be applied without using a laser.

Subsequently, when wiring <NUM> is formed, stage <NUM> is moved below second shaping unit <NUM>. In second shaping unit <NUM>, as illustrated in <FIG>, resin layer <NUM> is formed so as to cover the inner part of opening <NUM> and resin layer <NUM>. In this resin layer <NUM>, opening <NUM> is formed so that a part of wiring <NUM> formed on the upper surface of resin layer <NUM> is exposed. Similarly to resin layer <NUM>, resin layer <NUM> is formed by repeatedly performing the discharging of the UV curable resin by inkjet head <NUM> and the irradiation with the ultraviolet rays by irradiation device <NUM>.

Next, when resin layer <NUM> is formed, in discharge section <NUM> of second shaping unit <NUM>, as illustrated in <FIG>, dispense head <NUM> discharges conductive UV curable resin <NUM> to the inner part of opening <NUM> of resin layer <NUM>, that is, the upper surface of wiring <NUM> exposed via the opening <NUM>. At this time, dispense head <NUM> discharges conductive UV curable resin <NUM> so that the inner part of opening <NUM> is filled with conductive UV curable resin <NUM> and conductive UV curable resin <NUM> protrudes upward from the opening at the upper end of opening <NUM>. Then, by conductive UV curable resin <NUM> being irradiated with the ultraviolet rays by irradiation device <NUM>, conductive UV curable resin <NUM> exhibits the conductivity. Here, a conductive thermosetting resin may be used instead of conductive UV curable resin. Instead of the dispenser, other printing methods such as a stamp may be used.

Subsequently, stage <NUM> is moved to mounting unit <NUM>. In mounting unit <NUM>, electronic component (refer to <FIG>) <NUM> is supplied by tape feeder <NUM>, and mounting head <NUM> holds electronic component <NUM>. Then, as illustrated in <FIG>, by the operation of movement device <NUM>, electronic component <NUM> held by mounting head <NUM> is mounted on the upper surface of resin layer <NUM>. At this time, electronic component <NUM> is mounted on the upper surface of resin layer <NUM> so that electrode <NUM> of electronic component <NUM> comes in contact with conductive UV curable resin <NUM> discharged to opening <NUM> of resin layer <NUM>. In this way, electronic component <NUM> is fixedly mounted on the upper surface of resin layer <NUM> in a state of being electrically connected to pad <NUM> of inner layer plate <NUM>, that is, copper pattern <NUM>, via nickel-gold plating <NUM>, wiring <NUM>, and conductive UV curable resin <NUM>.

In addition, when electronic component <NUM> is mounted on the upper surface of resin layer <NUM>, inner layer plate <NUM> on which electronic component <NUM> is mounted is taken out from the custom section forming device <NUM>. Then, in general-purpose section forming device <NUM>, inner layer plate <NUM> on which electronic component <NUM> is mounted is conveyed into mounting unit <NUM> by conveyance device <NUM>.

In mounting unit <NUM>, electronic component <NUM> supplied from tape feeder is held by suction nozzle, and electronic component <NUM> held by the suction nozzle is mounted on the upper surface of solder resist <NUM> as illustrated in <FIG>. At this time, electronic component <NUM> is mounted on the upper surface of solder resist <NUM> so that electrode <NUM> of electronic component <NUM> comes in contact with solder paste <NUM> discharged on the upper surface of pad <NUM>.

Subsequently, inner layer plate <NUM> on which electronic component <NUM> is mounted on the upper surface of solder resist <NUM> is conveyed into heating unit <NUM> by conveyor device <NUM>. Then, heating unit <NUM> is heated by a reflow furnace. As a result, electronic component <NUM> is fixedly mounted on the upper surface of solder resist <NUM> in a state of being electrically connected to copper pattern <NUM> of inner layer plate <NUM> via nickel-gold plating <NUM> and solder paste <NUM>.

As described above, in circuit forming system <NUM>, resin layers <NUM> and <NUM>, wiring <NUM>, and the like are formed on custom region <NUM> by custom section forming device <NUM>, and electronic component <NUM> is mounted on the upper surface of resin layer <NUM>. In addition, in general-purpose region <NUM>, solder resist <NUM> and the like are formed by general-purpose section forming device <NUM>, and electronic component <NUM> is mounted on the upper surface of solder resist <NUM>. That is, in general-purpose region <NUM>, the board is formed according to a general method of manufacturing a printer substrate, and in custom region <NUM>, the board is formed according to the method of manufacturing a printer board using the 3D printer. As a result, it is possible to manufacture the printed substrate by taking advantages of each of the method of manufacturing the general printer board and the method of manufacturing the printer board using the 3D printer.

Specifically, in the method of manufacturing the general printed substrate, the printed substrate is manufactured using the exposure mask, or the like, therefore, the printed substrates having the circuit patterns according to the exposure masks or the like can be manufactured in large quantities, and thus, the productivity can be improved, and it is advantageous in terms of cost. On the other hand, if it is desired to change the manufacturing conditions of only a part of inner layer plate <NUM>, it is needed to create a new exposure mask, and thus, considering the mask creation cost, the mask creation period, and the like, the customizability and on-demand performance are low.

In addition, in the method of manufacturing the printed substrate using 3D printer, the circuit pattern can be changed only by changing a program that controls the operation of inkjet head <NUM> or the like, and it is possible to easily change the manufacturing conditions of only a part of one inner layer plate <NUM>. Therefore, in the method of manufacturing the printed substrate using the 3D printer, the customizability and the on-demand performance are extremely high. However, resin layers <NUM> and <NUM> formed of UV curable resin are immature as the materials for the printed substrates from a viewpoint of expansion coefficient, hardness, and the like, and the resistivity and thickness of wiring <NUM> formed by metal-containing liquid are inferior in resistivity, thickness, or the like of the wiring by the copper plating. In addition, in the method of manufacturing the printed substrate using the 3D printer, compared to a general method of manufacturing the printed substrate, the productivity is low and the cost required for UV curable resin, metal-containing liquid, and the like is disadvantageous in terms of cost.

In view of above description, in circuit forming system <NUM>, a general-purpose portion of the printed substrate is manufactured by a general method of manufacturing the printed substrate, that is, by general-purpose section forming device <NUM>, and a highly customizable portion of the printed substrate is manufactured by the method of manufacturing the printed substrate using the 3D printer, that is, by custom section forming device <NUM>.

Specifically, for example, in the printer board used for wearable devices, the power supply section, the control section, the output section, and the like are general-purpose portion and are manufactured by general-purpose section forming device <NUM>. On the other hand, a sensing section for detecting a predetermined detection value is manufactured by custom section forming device <NUM> because the customizability is high differently from that of the wearable devices according to the purpose.

That is, in the general-purpose portion such as the power supply section and the control section, the manufacturing step is performed on general-purpose region <NUM> described above, and in a high-customizability portion such as the antenna pattern and the sensing section, the manufacturing step for custom region <NUM> is performed. In this way, it is possible to manufacture the printed substrate by taking advantage of each of the method of manufacturing the general printer board and the method of manufacturing the printer board using the 3D printer, and for example, it is possible to appropriately deal with the manufacturing of various kinds in small quantity of printed substrates.

In addition, in circuit forming system <NUM>, when inner layer plate <NUM> is formed on inner layer plate forming unit <NUM> of general-purpose section forming device <NUM>, unevennesses are formed on the upper surface of insulating layer <NUM>. In second shaping unit <NUM> of custom section forming device <NUM>, resin layer <NUM> is formed on the upper surface of insulating layer <NUM> on which the unevennesses are formed. As a result, the adhesion between insulating layer <NUM> and resin layer <NUM> is increased, and the strength and reliability of the printed substrate are ensured.

In addition, in rust prevention unit <NUM> of general-purpose section forming device <NUM>, after the palladium removing process is performed, the nickel-gold plating process is performed, and pad <NUM> of copper pattern <NUM> is covered with nickel-gold plating <NUM>. Therefore, nickel-gold plating <NUM> is formed only on pad <NUM> of inner layer plate <NUM>, and it is possible to prevent nickel-gold plating <NUM> from being formed on insulating layer <NUM>. As a result, pad <NUM> can be appropriately rust-prevented by nickel-gold plating <NUM>, and the conductivity of the conductive section is ensured.

In the embodiment described above, in solder printing unit <NUM> of general-purpose section forming device <NUM>, solder paste <NUM> is printed on the upper surface of pad <NUM> using the solder mask, but solder paste <NUM> may be discharged on the upper surface of pad <NUM> by a dispenser head or the like. In such a case, not before resin layer <NUM> is formed on custom region <NUM> but after resin layer <NUM> is formed, solder paste <NUM> may be discharged on the upper surface of pad <NUM>. In addition, if solder paste <NUM> is discharged on the upper surface of pad <NUM> after resin layer <NUM> is formed, the maximum height of general-purpose region <NUM> when resin layer <NUM> is formed is the upper surface of solder resist <NUM>. Therefore, resin layer <NUM> is formed such that the upper end surface of resin layer <NUM> becomes higher than the upper end surface of solder resist <NUM> of general-purpose region <NUM>.

In addition, in the embodiment described above, the nickel-gold plating process is performed before resin layer <NUM> is formed, but the nickel-gold plating process may be performed after resin layer <NUM> is formed. In such a case, as illustrated in <FIG>, nickel-gold plating <NUM> is formed only on the upper surface of pad <NUM> exposed from opening <NUM> of resin layer <NUM>. As described above, by performing the nickel-gold plating process after resin layer <NUM> is formed, it becomes possible to omit the palladium removing process in rust prevention unit <NUM>. This is because the top surface of insulating layer <NUM>, which is the target of the palladium removing process, is covered with resin layer <NUM>.

In addition, in the embodiment described above, solder resist <NUM> is formed only in general-purpose region <NUM> and not in custom region <NUM>, but solder resist <NUM> may be formed on both general-purpose region <NUM> and custom region <NUM>. In such a case, in custom region <NUM>, as illustrated in <FIG>, resin layer <NUM> is formed on the upper surface of solder resist <NUM>. At this time, opening <NUM> is formed on resin layer <NUM> so that the upper surface of nickel-gold plating <NUM> covering pad <NUM> is exposed. Resin layer <NUM> is formed by the same method as resin layer <NUM>. As described above, by forming solder resist <NUM> in custom region <NUM> and forming resin layer <NUM> on the upper surface of solder resist <NUM>, resin layer <NUM> can be thinned. As a result, it is possible to shorten the formation time of resin layer <NUM>.

Incidentally, the unevenness is formed on the top surface of solder resist <NUM> on which resin layer <NUM> is formed. As a result, the adhesion between resin layer <NUM> and solder resist <NUM> can be improved. As a method of forming unevenness on the top surface of solder resist <NUM>, there is a method in which the surface of solder resist <NUM> is chemically roughened with potassium permanganate or the like to form unevenness, a method in which the surface of solder resist <NUM> is physically roughened by blasting or the like to form the unevenness. In addition, by increasing the wettability of the top surface of solder resist <NUM>, the adhesion between resin layer <NUM> and solder resist <NUM> can be increased. As a method for increasing the wettability of the top surface of solder resist <NUM>, there is a method in which plasma treatment is performed on the top surface of solder resist <NUM>.

In addition, in the embodiment described above, the nickel-gold plating process is performed to prevent pad <NUM> from rust, but rust preventing process other than the nickel-gold plating process can be used. Specifically, for example, nickel-palladium-gold plating process, organic solderability preservative (OSP) process, or the like can be adopted.

Incidentally, in the embodiment described above, custom section forming device <NUM> is an example of the printed substrate forming device. First shaping unit <NUM> is an example of a wiring forming device. Second shaping unit <NUM> is an example of the resin layer forming device. Inner layer plate <NUM> is an example of the base. Insulating layer <NUM> is an example of the insulating layer. Copper pattern <NUM> is an example of the conductor layer. Solder resist <NUM> is an example of the solder resist. Pad <NUM> is an example of the conduction section. Resin layer <NUM> is an example of the resin layer. Opening <NUM> is an example of the opening section. Wiring <NUM> is an example of the wiring. The step performed by first shaping unit <NUM> is an example of the wiring forming step. The step performed by second shaping unit <NUM> is an example of the resin layer forming step. The step performed by rust prevention unit <NUM> is an example of the rust prevention step and the unevenness forming step. The step of forming the unevenness on the top surface of solder resist <NUM> and the step of improving the wettability of the top surface of solder resist <NUM> are examples of the surface treatment step.

The present invention is not limited to the embodiment described above, and can be embodied in various aspects with various modifications and improvements based on the knowledge of those skilled in the art. For example, in the embodiment described above, circuit forming system <NUM> is configured with two devices, custom section forming device <NUM> and general-purpose section forming device <NUM>, but may be configured by one device having both the function of custom section forming device <NUM> and the function of general-purpose section forming device <NUM>.

Claim 1:
A printed substrate forming method comprising:
providing a base (<NUM>) which is composed of an insulating layer (<NUM>) and a conductor layer (<NUM>), wherein the base comprises a predetermined region (<NUM>) on which a solder resist is formed with through-holes in the solder resist so that a portion of the conductive layer (<NUM>) is exposed to form conduction sections (<NUM>) and which is provided with solder paste (<NUM>) on the upper surface of these conduction sections (<NUM>);
printing a first resin layer (<NUM>) with curable resin in a specific region (<NUM>), wherein the specific region (<NUM>) is a region other than the predetermined region (<NUM>), wherein the first resin layer (<NUM>) has first openings (<NUM>) in the resin layer (<NUM>) for exposing other conduction sections (<NUM>);
forming a wiring (<NUM>) by discharging metal-containing liquid which contains metal fine particles from the conduction sections (<NUM>) exposed by the first openings (<NUM>) onto a top surface of the resin layer (<NUM>) via the inner wall surface of the first openings (<NUM>), and firing the metal-containing liquid;
printing a second resin layer (<NUM>) in the specific region so as to cover the inner part of the first openings (<NUM>) and the first resin layer (<NUM>), wherein the second resin layer (<NUM>) has second openings (<NUM>) so that a part of the wiring (<NUM>) is exposed; and
dispensing a conductive UV-curable resin or a conductive thermosetting resin (<NUM>) to the inner part of the second openings (<NUM>).