JP2007296425A - Pattern forming method, droplet ejecting apparatus and circuit module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pattern forming method by which the drying efficiency of droplets is improved to reduce the forming defect of a pattern comprising the droplets, a droplet ejecting apparatus and a circuit module. <P>SOLUTION: Laser beam Le emitted from a semiconductor laser LD is led to an irradiation position along the tangential direction of a pattern forming surface 4Sa by a reflection mirror 27 mounted on a carriage 20. A controlling means scans the droplets Fb landed on the pattern forming surface 4Sa along the scanning direction to make the laser beam Le incident on the end part of the droplets Fb positioned at an irradiation position Pe. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a pattern forming method, a droplet discharge device, and a circuit module.

  2. Description of the Related Art In recent years, circuit modules on which electronic components such as semiconductor elements are mounted include those having a low temperature co-fired ceramic multilayer substrate (Low Temperature Co-fired Ceramics: LTCC multilayer substrate). Since the LTCC multilayer substrate can fire the laminated green sheets at a low temperature of 900 ° C. or lower, a low melting point metal such as silver or gold can be used for the internal wiring, and the resistance of the internal wiring can be reduced.

In the manufacturing process of such an LTCC multilayer substrate, a metal paste or metal ink is used to draw a wiring pattern on each green sheet before lamination. As this drawing method, Patent Document 1 proposes a so-called ink jet method in which metal ink is discharged as fine droplets. The ink jet method draws a wiring pattern by joining minute droplets, and therefore can quickly respond to changes in internal wiring design (for example, high density of internal wiring or narrowing of wiring width and wiring pitch). be able to.
JP 2005-57139 A

  By the way, the droplet landed on the green sheet varies with time in size, shape, and the like based on the surface state of the green sheet and the surface tension of the droplet. The size of the wiring pattern is regulated according to the drying timing of the droplet whose size or shape varies. For example, a droplet made of metal ink having an outer diameter of 30 μm reaches the lyophilic green sheet and expands the outer diameter to 70 μm after 100 milliseconds, and after 200 milliseconds, the outer diameter decreases. Further, the thickness is set to 100 μm. Therefore, if the drying timing of the droplets varies within a range from 100 milliseconds to 200 milliseconds, the line width of the corresponding wiring pattern varies within a range of about 70 μm to 100 μm.

  Therefore, in order to suppress variation in pattern size, laser drying in which laser light is irradiated to the droplets that have landed on the green sheet has been proposed. In laser drying, droplets are dried only in the laser light irradiation region. For this reason, the drying timing of the landed droplets can be controlled with high accuracy, and variations in pattern size can be suppressed.

  However, in a droplet discharge device used for the ink jet method, in general, the gap between the droplet discharge head and the object is narrowed to several hundred μm in order to ensure the droplet landing accuracy. For this reason, when drying a droplet immediately after landing, that is, a droplet located immediately below the droplet discharge head, it is along a substantially tangential direction of the target in a narrow gap between the droplet discharge head and the target. The laser beam must be irradiated. As a result, the optical cross section (beam spot) of the laser light formed on the object is enlarged, and the intensity of the laser light necessary for drying the droplets cannot be secured. For this reason, there is a risk of insufficient drying of the droplets, resulting in poor pattern formation.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to improve the drying efficiency of droplets and reduce the formation failure of patterns composed of droplets, and droplet ejection. An apparatus and a circuit module are provided.

  According to the pattern forming method of the present invention, a pattern forming material is discharged as a droplet onto a substrate, and the droplet landed on the substrate is dried to form a pattern composed of the droplet on the substrate. In the method, the end of the droplet landed on the substrate is irradiated with laser light along a substantially tangential direction of the substrate to dry the droplet.

  According to the pattern forming method of the present invention, the end portion of the droplet that has landed on the substrate receives laser light that is close to the substantially tangential direction of the substrate, that is, the normal direction of the surface of the droplet. Therefore, the amount of reflection on the droplet surface can be reduced as compared with the case where the laser beam incident on the droplet enters from the top of the droplet. As a result, the absorption efficiency of the laser beam with respect to the droplet can be improved, the drying efficiency of the droplet can be improved, and the formation failure of the pattern made of the droplet can be reduced.

  According to the pattern forming method of the present invention, a pattern forming material is discharged as a droplet onto a substrate, and the droplet landed on the substrate is dried to form a pattern composed of the droplet on the substrate. In the method, when the droplet landed on the substrate has a hemispherical shape, the droplet is dried by irradiating a laser beam toward the center of the droplet.

  According to the pattern forming method of the present invention, a substantially hemispherical droplet receives a laser beam along a substantially normal direction of the droplet surface. Therefore, the amount of reflection of laser light incident on the droplet can be reduced on the droplet surface. As a result, the absorption efficiency of the laser beam with respect to the droplet can be improved, the drying efficiency of the droplet can be improved, and the formation failure of the pattern made of the droplet can be reduced.

In this pattern forming method, the droplets may be dried by irradiating laser light along a substantially tangential direction of the substrate toward the center of the droplets.
According to this pattern forming method, even when various members (for example, a droplet discharge head that discharges droplets) are positioned on the droplet region, the irradiated laser beam is shielded by the same member. Can be guided to the region of the droplet without any problem. Further, the drying efficiency of the droplet can be improved by the amount of irradiation of the laser beam from the substantially normal direction of the droplet surface. Therefore, pattern formation defects can be reduced without restricting the degree of freedom regarding the application range of the substrate and the apparatus configuration of the droplet discharge device.

  The droplet discharge device of the present invention is a droplet discharge device including a droplet discharge head that discharges a pattern forming material to a substrate, and directs laser light along a substantially tangential direction of the substrate toward the substrate. Laser irradiation means for irradiating; scanning means for scanning the substrate relative to the droplet discharge head and the laser irradiation means along one direction; and an end of the droplet landed on the substrate. Control means for driving and controlling the scanning means so as to be positioned in the laser light region.

  According to the droplet discharge device of the present invention, the laser irradiation means is incident on the end portion of the droplet landed on the substrate with the laser beam along the substantially tangential direction of the substrate. Therefore, the laser beam along the substantially normal direction of the droplet surface is incident on the end of the droplet landed on the substrate. As a result, the laser beam incident on the droplet can reduce the reflection amount on the surface of the droplet and improve the absorption efficiency of the laser beam with respect to the droplet. Therefore, it is possible to improve the drying efficiency of the droplets and reduce the formation failure of the pattern composed of the droplets.

In the droplet discharge device, the scanning unit relatively scans the substrate along the one direction and the opposite direction of the one direction, and the laser irradiation unit includes the one direction and the one direction. When the control means moves the droplet landed on the substrate relative to the laser irradiation means along the one direction, The scanning means is driven and controlled so that the end of the droplet is positioned in the laser light region substantially along the one direction, and the droplet landed on the substrate is moved along the opposite direction of the one direction to the laser. The scanning unit may be driven and controlled so that the end of the droplet is positioned in a laser light region along a direction substantially opposite to the one direction when moving relative to the irradiation unit.

  According to this droplet discharge device, the laser irradiation means has a laser beam along the substantially scanning direction of the droplet with respect to the end portion of the droplet that is relatively scanned in one direction and the opposite direction of the one direction. Is incident. Therefore, the scanning direction of the droplet and the incident direction of the laser beam on the droplet can be made substantially the same direction. As a result, the drying efficiency of the droplets can be improved with higher reproducibility, and the formation failure of the pattern composed of droplets can be more reliably reduced.

  In the liquid droplet ejection apparatus, the control unit may be configured so that when the liquid droplets that have landed on the substrate have a hemispherical shape, the end of the liquid droplet is positioned in the laser light region. May be driven and controlled.

  According to this droplet discharge device, the laser beam along the substantially tangential direction of the substrate is incident on the end portion of the droplet having a hemispherical shape. Therefore, the laser beam from the substantially normal direction is incident on the droplet surface corresponding to the end of the droplet. As a result, the amount of reflection of the laser light applied to the droplet on the surface of the droplet can be further reduced, and the absorption efficiency of the laser light with respect to the droplet can be improved more reliably.

  The droplet discharge device of the present invention is a droplet discharge device provided with a droplet discharge head for discharging a pattern forming material to a substrate as a droplet, and a laser irradiation means for irradiating a laser beam toward the substrate; A scanning unit that scans the substrate relative to the droplet discharge head and the laser irradiation unit along one direction; and the droplet that has landed on the substrate has a hemispherical shape. Control means for driving and controlling the scanning means so that the center of the laser beam is positioned at the irradiation position of the laser beam.

  According to the droplet discharge device of the present invention, the laser irradiation unit makes the laser beam directed toward the center of the droplet having a hemispherical shape incident. Therefore, laser light is incident on the droplet having a hemispherical shape along a substantially normal direction of the surface of the droplet. As a result, the amount of reflection of laser light incident on the droplet can be reduced on the surface of the droplet, and the absorption efficiency of the laser light with respect to the droplet can be improved. Therefore, it is possible to improve the drying efficiency of the droplets and reduce the formation failure of the pattern made of the droplets.

In this droplet discharge apparatus, the laser irradiation unit may irradiate a laser beam along a substantially tangential direction of the substrate.
According to this droplet discharge device, laser light is irradiated along a substantially tangential direction of the substrate. Therefore, even when the landed droplet has a hemispherical shape in a region facing the droplet discharge head, the laser light is incident along a substantially normal direction of the droplet surface. Therefore, the droplet immediately after landing can be dried, and the degree of freedom of the shape and size of the pattern can be increased.

In the droplet discharge device, the scanning unit relatively scans the substrate along the one direction and the opposite direction of the one direction, and the laser irradiation unit includes the one direction and the one direction. When the control means moves the droplet landed on the substrate relative to the laser irradiation means along the one direction, The scanning unit is driven and controlled so that the center of the droplet is positioned at the irradiation position of the laser beam substantially along the one direction, and the droplet landed on the substrate is moved along the opposite direction of the one direction to the laser. The scanning unit may be driven and controlled so that the center of the droplet is positioned at a laser beam irradiation position along a direction substantially opposite to the one direction when moving relative to the irradiation unit.

  According to this droplet discharge device, the laser irradiation means has a laser beam along the substantially scanning direction of the droplet with respect to the end portion of the droplet that is relatively scanned in one direction and the opposite direction of the one direction. Is incident. Therefore, the scanning direction of the droplet and the incident direction of the laser beam on the droplet can be made substantially the same direction. As a result, the drying efficiency of the droplets can be improved with higher reproducibility, and the formation failure of the pattern composed of droplets can be more reliably reduced.

  The liquid droplet ejection apparatus further includes a carriage on which the liquid droplet ejection head is mounted, and the laser irradiation unit is mounted on the carriage and emits the laser light, and is mounted on the carriage and is mounted on the carriage. And an irradiation optical system for irradiating the droplet with laser light emitted from a semiconductor laser.

  According to this droplet discharge device, a droplet discharge head mounted on a carriage discharges a droplet toward a substrate, and a semiconductor laser mounted on the carriage and an irradiation optical system are droplet regions landed on the substrate. Irradiate with laser light. Therefore, the relative position of the laser beam can be maintained with respect to the landing position of the droplet. Therefore, the end of the landed droplet and the center of the droplet exhibiting a hemispherical shape can be positioned more reliably at the irradiation position of the laser beam. As a result, the laser beam along the normal direction of the droplet surface can be more reliably irradiated onto the region of the droplet. Furthermore, the droplet discharge device can be reduced in size and weight.

In this droplet discharge device, the pattern forming material may be a metal ink in which metal fine particles are dispersed, and the substrate may be a low-temperature fired ceramic substrate.
According to this droplet discharge device, the laser light irradiates the region of the metal ink droplet landed on the low-temperature fired ceramic substrate, thereby reducing the reflection amount on the surface of the droplet. Therefore, it is possible to improve the drying efficiency of the metal ink, and it is possible to reduce defective formation of a pattern made of the metal ink (for example, a wiring pattern or an element pattern of a low-temperature fired ceramic substrate).

  The circuit module of the present invention is a circuit module comprising: a substrate; a circuit element formed on the substrate; and a metal wiring formed on the substrate and electrically connected to the circuit element. Was formed by the droplet discharge device.

  According to the circuit module of the present invention, formation defects of metal wiring can be reduced.

Hereinafter, an embodiment embodying the present invention will be described with reference to FIGS. First, the circuit module 1 of the present invention will be described.
In FIG. 1, a circuit module 1 includes an LTCC multilayer substrate 2 formed in a plate shape, and a plurality of semiconductor chips 3 that are wire-bonded or flip-chip connected above the LTCC multilayer substrate 2. ing.

  On the LTCC multilayer substrate 2, a plurality of low-temperature fired ceramic substrates (hereinafter simply referred to as insulating layers 4) formed in a sheet shape are laminated. Each insulating layer 4 is a sintered body made of a glass ceramic material (for example, a mixture of a glass component such as borosilicate alkali oxide and a ceramic component such as alumina), and has a thickness of several hundred μm. Yes.

Between each insulating layer 4, various circuit elements 5 such as a resistance element, a capacitive element, and a coil element, and a plurality of internal wirings 6 as metal wirings that electrically connect each circuit element 5 are formed. ing. Each circuit element 5 and each internal wiring 6 are sintered bodies of metal fine particles such as silver and silver alloy, and are formed by using the droplet discharge device 10 of the present invention. Via wirings 7 having a stacked via structure or a thermal via structure are formed in each insulating layer 4, and each circuit element 5 and each internal wiring 6 are electrically connected between the layers. Each via wiring 7 is a sintered body of fine metal powder such as silver or silver alloy, like each circuit element 5 and each internal wiring 6.

Next, a manufacturing method of the LTCC multilayer substrate 2 will be described with reference to FIG.
In FIG. 2, first, via holes 7H are punched and formed on a green sheet 4S as a substrate that enables the insulating layer 4 to be cut out, by punching or laser processing. Next, screen printing using a metal paste is performed a plurality of times on the green sheet 4S, and the via hole 7H is filled with the metal paste to form a via pattern 7F made of the metal paste. Next, the upper surface of the green sheet 4S (hereinafter, simply referred to as the pattern formation surface 4Sa) using the metal ink F (in this embodiment, aqueous silver ink) as a pattern formation material in which metal nanoparticles are dispersed in an aqueous solvent. Inkjet printing is applied.

  More specifically, the droplet Fb of the metal ink F is ejected onto the pattern formation surface 4Sa on the area for forming the circuit element 5 and the internal wiring 6 (hereinafter simply referred to as the pattern formation area). The droplets Fb landed on are dried. Then, the discharging operation and the drying operation are repeated, and the element pattern 5F and the wiring pattern 6F corresponding to the pattern formation region are drawn. At this time, the droplets Fb that have landed on the pattern formation region are dried by making the laser beam Le incident on the landed droplets Fb.

  When the element pattern 5F, the wiring pattern 6F, and the via pattern 7F are formed on the green sheet 4S, a plurality of green sheets 4S are stacked together, and a region corresponding to the LTCC multilayer substrate 2 is cut out as a stacked body 4B and fired. That is, the green sheet 4S, the element pattern 5F, the wiring pattern 6F, and the via pattern 7F are collectively laminated and fired simultaneously. Thus, the LTCC multilayer substrate 2 having the insulating layer 4, the circuit element 5, the internal wiring 6, and the via wiring 7 is formed.

Next, the droplet discharge device 10 for drawing the element pattern 5F and the wiring pattern 6F will be described with reference to FIG. FIG. 3 is an overall perspective view showing the droplet discharge device 10.
In FIG. 3, the droplet discharge device 10 includes a base 11 formed in a rectangular parallelepiped shape. A pair of guide grooves 12 extending along the longitudinal direction (Y arrow direction) is formed on the upper surface of the base 11. Above the guide groove 12, a stage 13 is provided as a scanning unit that moves along the guide groove 12 in the Y arrow direction and the counter-Y arrow direction. A placement portion 14 is formed on the upper surface of the stage 13, and the green sheet 4S with the pattern formation surface 4Sa on the upper side is placed. The placement unit 14 positions and fixes the placed green sheet 4S with respect to the stage 13, and conveys the green sheet 4S in the Y arrow direction and the anti-Y arrow direction. In the present embodiment, in FIG. 3, the Y arrow direction is defined as the scanning direction. Moreover, the conveyance speed along the scanning direction of the green sheet 4S is defined as the scanning speed Vy.

  On the base 11, guide members 16 formed in a gate shape are installed on both sides in the X arrow direction orthogonal to the scanning direction so as to straddle the base 11. On the upper side of the guide member 16, an ink tank 17 extending in the direction of the arrow X is disposed. The ink tank 17 stores the metal ink F, and supplies the metal ink F to a droplet discharge head (hereinafter simply referred to as “discharge head”) 21 disposed below at a predetermined pressure.

A pair of upper and lower guide rails 18 extending in the X arrow direction are formed on the side opposite to the Y arrow direction of the guide member 16 over substantially the entire width in the X arrow direction. A carriage 20 is attached to the pair of guide rails 18 and moves along the guide rails 18 in the X arrow direction and the counter X arrow direction. On the bottom surface 20a of the carriage 20 and on the scanning direction side, the ejection head 2 is disposed.
1 is installed. 4 is a perspective view of the ejection head 21 as viewed from the lower side (the green sheet 4S side), and FIG. 5 is a cross-sectional view taken along line AA of FIG. FIG. 6 is a schematic side view of the carriage 20.

  In FIG. 4, the discharge head 21 is formed in a rectangular parallelepiped shape extending in the X arrow direction. A nozzle plate 22 is provided on the lower side of the discharge head 21 (the green sheet 4S side: the upper side in FIG. 4). The nozzle plate 22 is formed in a plate shape extending in the direction of the arrow X, and a nozzle forming surface 22a is formed on the lower surface (the upper surface in FIG. 4). The nozzle formation surface 22a is formed substantially parallel to the pattern formation surface 4Sa of the green sheet 4S, and when the green sheet 4S is positioned directly below the ejection head 21, the distance between the nozzle formation surface 22a and the pattern formation surface 4Sa. (Platen gap) is kept at a predetermined distance (in this embodiment, 300 μm). In the nozzle forming surface 22a, a plurality of nozzles N penetrating in the normal direction of the nozzle forming surface 22a are arranged along the X arrow direction.

  In FIG. 5, cavities 23 communicating with the ink tanks 17 are formed above the nozzles N, respectively. The cavity 23 supplies the metal ink F from the ink tank 17 to the corresponding nozzle N. A vibration plate 24 is attached to the upper side of each cavity 23 to vibrate in the vertical direction and expand and contract the volume in the cavity 23. A plurality of piezoelectric elements PZ corresponding to the nozzles N are disposed on the upper side of the vibration plate 24.

  Each piezoelectric element PZ contracts and expands in the vertical direction to vibrate the corresponding region of the diaphragm 24 in the vertical direction, and the metal ink F is supplied from the corresponding nozzle N to a predetermined volume (in this embodiment, 10 pl) of liquid. A droplet Fb is discharged. The droplet Fb flies in the direction opposite to the arrow Z of the corresponding nozzle N and lands on a position on the opposing pattern formation surface 4Sa. In the present embodiment, the position on the pattern forming surface 4Sa and corresponding to the anti-Z arrow direction of each nozzle N, that is, the position where the droplet Fb lands is defined as the landing position P.

  The landing droplet Fb repeats stretching vibration along the surface direction of the pattern formation surface 4Sa, and then exhibits a hemispherical shape with a thickness in the Z arrow direction of 10 μm or more, and eventually spreads wet along the pattern formation surface 4Sa. . In the present embodiment, the time required for the landed droplet Fb to have a hemispherical shape is defined as the irradiation standby time T. Further, the distance that the droplet Fb is scanned during the irradiation standby time T is defined as the irradiation standby distance WF (= scanning speed Vy × irradiation standby time T), and the irradiation standby distance WF in the scanning direction from the landing position P. A position that is displaced by a distance is defined as the irradiation position Pe.

  That is, the droplet Fb that lands on the landing position P is displaced by the irradiation standby distance WF in the scanning direction from the landing position P when the irradiation standby time T elapses from the time of landing, and a hemispherical surface whose center is the irradiation position Pe. Present. In the present embodiment, the shape of the landed droplet Fb is observed using a landing observation camera such as an ultra-high speed camera, and the irradiation waiting time T (for example, 500 micron) is determined based on the change over time of the droplet shape. Second).

  In FIG. 6, an emission hole H penetrating to the inside of the carriage 20 is formed on the bottom surface 20 a of the carriage 20 in the anti-scanning direction (anti-Y arrow direction) of the ejection head 21. The exit hole H is formed so that the width in the X arrow direction is substantially the same as the width of the ejection head 21 in the X arrow direction. On the upper side of the emission hole H, a semiconductor laser LD constituting laser irradiation means is disposed.

The semiconductor laser LD emits a strip-like collimated linearly polarized laser beam Le extending downward substantially in the X-arrow direction of the emission hole H downward. The wavelength of the laser beam Le emitted from the semiconductor laser LD is set in the range of the absorption wavelength of the metal ink F (in this embodiment, 808 nm).

  Inside the exit hole H, a cylindrical lens 25 constituting an irradiation optical system is disposed. The cylindrical lens 25 is a lens having a curvature only in the Y arrow direction, and the width in the X arrow direction is the same size as the width of the ejection head 21 in the X arrow direction. When receiving the laser beam Le from the semiconductor laser LD, the cylindrical lens 25 converges only the component of the laser beam Le in the Y arrow direction (or anti-Y arrow direction) and emits it downward. The convergent laser beam Le has a beam waist width of 10 μm or less.

  Below the exit hole H, a mirror stage 26 extending below the carriage 20 and a reflection mirror 27 that is rotatably supported by the mirror stage 26 and constitutes an irradiation optical system are disposed. The mirror stage 26 supports the reflection mirror 27 so as to be rotatable about a rotation axis along the X arrow direction. The reflection mirror 27 is a galvanometer mirror having a reflection surface 27 m on the cylindrical lens 25 side, and the width in the X arrow direction is the same size as the width of the ejection head 21 in the X arrow direction.

  The reflection mirror 27 receives the laser beam Le from the cylindrical lens 25 by the reflection surface 27m, reflects the laser beam Le along the substantially tangential direction of the pattern formation surface 4Sa, and normal lines of the laser beam Le and the pattern formation surface 4Sa. And the angle (irradiation angle θe) is approximately 90 ° (88 ° in this embodiment). Further, the reflection mirror 27 guides the beam waist of the reflected laser beam Le to the irradiation position Pe located below the ejection head 21. The laser beam Le guided to the irradiation position Pe is incident inward from the end of the droplet Fb on the side opposite to the scanning direction when the landed droplet Fb is positioned at the irradiation position Pe.

  In the present invention, the end of the droplet Fb is a region of the surface (gas-liquid interface) of the landed droplet Fb, and the surface direction (anti-Y) of the pattern formation surface 4Sa from the center of the droplet Fb. This is the region that is the farthest away in the direction of the arrow. For example, when the droplet Fb has a hemispherical shape, the outer periphery of the bottom of the droplet Fb becomes the end of the droplet Fb. Further, when the droplet Fb has a disk shape, the side surface of the droplet Fb becomes the end of the droplet Fb.

  At the end of the droplet Fb, the angle between the normal of the droplet surface and the tangent of the pattern formation surface 4Sa is the normal of the other droplet surface (for example, the top surface of the droplet Fb) and the pattern formation surface. It becomes smaller than the angle formed with the 4Sa tangent. Therefore, at the end of the droplet Fb, the angle (“incident angle”) between the normal of the droplet surface and the laser light Le is smaller than the “incident angle” on the other droplet surfaces.

  Moreover, the droplet Fb of the present embodiment has a hemispherical shape when the center thereof is located at the irradiation position Pe. The laser beam Le guided to the irradiation position Pe enters from the hemispherical droplet surface toward the center of the droplet Fb. Therefore, when the center of the droplet Fb is located at the irradiation position Pe, the laser beam Le incident on the droplet Fb is incident along the substantially normal direction of the droplet surface regardless of the incident direction. The “incident angle” is set to approximately 0 °.

  On the other hand, the laser beam Le incident on the droplet Fb is reflected as reflected light by the portion not transmitted to the droplet Fb. The reflectance of the laser beam Le is derived by the following formulas when the polarization state is P-polarized light (reflectance Rp) and when it is S-polarized light (reflectance Rs), respectively. However, the refractive index of air is N1, the refractive index of the droplet Fb is N2, and the “incident angle” is θ.

  However,

  The reflectance Rp and the reflectance Rs each decrease as the “incident angle” decreases, and when the “incident angle” becomes approximately 0 °, both become several percent. Therefore, the laser light Le incident along the substantially tangential direction toward the end of the droplet Fb or the laser beam Le incident toward the center of the hemispherical droplet Fb has an “incident angle” approximately. In order to obtain 0 °, most of the light is transmitted through the droplet Fb and absorbed.

  As a result, the absorptance of the laser beam Le can be improved, and the corresponding droplet Fb is surely dried to form a layer pattern FP that is not insufficiently dried. Then, by laminating the layer patterns FP in order, the wiring pattern 6F can be formed, and the formation defects can be reduced.

Next, the electrical configuration of the droplet discharge device 10 configured as described above will be described with reference to FIG.
In FIG. 7, a control device 40 as a control means includes a CPU, a ROM, a RAM, and the like, and moves the stage 13 and the carriage 20 in accordance with the stored various data and various control programs, as well as the semiconductor laser LD and the piezoelectric devices. The drive of the element PZ is controlled.

  An input device 41 having operation switches such as a start switch and a stop switch is connected to the control device 40. The input device 41 inputs information related to the position coordinates of the pattern formation region (layer pattern FP) with respect to the drawing plane (pattern formation surface 4Sa) to the control device 40 as drawing information Ia in a predetermined format. The control device 40 receives the drawing information Ia from the input device 41 and generates bitmap data BMD.

  The bitmap data BMD is data that specifies whether each piezoelectric element PZ is turned on or off according to the value (0 or 1) of each bit. The bitmap data BMD is data that defines whether or not the droplets Fb are ejected to respective positions on the drawing plane (pattern formation surface 4Sa) through which the ejection head 21 passes. That is, the bitmap data BMD is for discharging the droplet Fb to each target position defined in the pattern formation region.

An X-axis motor drive circuit 42 is connected to the control device 40 and outputs a drive control signal corresponding to the X-axis motor drive circuit 42. In response to the drive control signal from the control device 40, the X-axis motor drive circuit 42 rotates the X-axis motor MX for moving the carriage 20 forward or backward. An X-axis encoder XE is connected to the X-axis motor drive circuit 42, and a detection signal from the X-axis encoder XE is input. Based on the detection signal from the X-axis encoder XE, the X-axis motor drive circuit 42 generates a signal related to the moving direction and moving amount of the carriage 20 (each landing position P) with respect to the pattern forming surface 4Sa and outputs the signal to the control device 40. To do.

  A Y-axis motor drive circuit 43 is connected to the control device 40 and outputs a drive control signal corresponding to the Y-axis motor drive circuit 43. In response to the drive control signal from the control device 40, the Y-axis motor drive circuit 43 rotates the Y-axis motor MY for moving the stage 13 forward or backward. That is, the control device 40 scans the stage 13 (pattern formation surface 4Sa) during the irradiation standby time T by the irradiation standby distance WF via the Y-axis motor drive circuit 43 and reaches the landing position P. Is scanned to the irradiation position Pe.

  A Y-axis encoder YE is connected to the Y-axis motor drive circuit 43, and a detection signal is input from the Y-axis encoder YE. The Y-axis motor drive circuit 43 generates a signal related to the moving direction and moving amount of the stage 13 (pattern forming surface 4Sa) based on the detection signal from the Y-axis encoder YE, and outputs the signal to the control device 40. The control device 40 calculates the relative position of the landing position P with respect to the pattern forming surface 4Sa based on the signal from the Y-axis motor drive circuit 43, and every time the target position is located at the corresponding landing position P, the discharge timing signal LP. Is output.

  The control device 40 is connected to the semiconductor laser drive circuit 44, and outputs a drawing start signal S1 when starting a drawing operation, and outputs a drawing end signal S2 when ending the drawing operation. The semiconductor laser drive circuit 44 inputs the drawing start signal S1 from the control device 40, emits the laser light Le to the semiconductor laser LD, and inputs the drawing end signal S2 from the control device 40, and inputs the laser light to the semiconductor laser LD. Le emission is stopped. In other words, the control device 40 drives and controls the semiconductor laser LD during the drawing operation via the semiconductor laser driving circuit 44, and performs the irradiation operation of the laser light Le.

  A discharge head drive circuit 45 is connected to the control device 40, and a piezoelectric element drive voltage COM1 for driving each piezoelectric element PZ is output in synchronization with the discharge timing signal LP. Further, the control device 40 generates an ejection control signal SI synchronized with a predetermined clock signal based on the bitmap data BMD, and serially transfers the ejection control signal SI to the ejection head drive circuit 45. The ejection head drive circuit 45 sequentially converts the ejection control signal SI from the control device 40 into serial / parallel corresponding to each piezoelectric element PZ. Each time the ejection head drive circuit 45 receives the ejection timing signal LP from the control device 40, the ejection head drive circuit 45 latches the serial / parallel converted ejection control signal SI and supplies the piezoelectric element drive voltage COM1 to each selected piezoelectric element PZ. To do.

Next, a method for drawing the element pattern 5F and the wiring pattern 6F using the droplet discharge device 10 will be described.
First, as shown in FIG. 3, the green sheet 4S is placed on the stage 13 so that the pattern formation surface 4Sa is on the upper side. At this time, the stage 13 arranges the green sheet 4S in the anti-scanning direction of the carriage 20.

From this state, the drawing information Ia is input from the input device 41 to the control device 40, and the control device 40 generates and stores bitmap data BMD based on the drawing information Ia. Next, when the green sheet 4S is scanned, the control device 40 causes the carriage 20 (discharge head 31) to pass through the X-axis motor drive circuit 42 so that each target position passes the corresponding landing position P. Move to the position of. When the carriage 20 is arranged and moved, the control device 40 moves the Y
The scanning of the green sheet 4S is started via the shaft motor drive circuit 43.

  When scanning of the green sheet 4S is started, the control device 40 outputs a drawing start signal S1 to the semiconductor laser drive circuit 44, and emits laser light Le from the semiconductor laser LD. The laser beam Le emitted from the semiconductor laser LD is reflected by the reflecting mirror 27 in the substantially tangential direction of the green sheet 4S and guided to the irradiation position Pe on the pattern forming surface 4Sa.

When the scanning of the green sheet 4S is started, the control device 40 outputs an ejection control signal SI generated based on the bitmap data BMD to the ejection head drive circuit 45.
When the scanning of the green sheet 4S is started, the control device 40 outputs the ejection timing signal LP to the ejection head driving circuit 45 every time the landing position P is located at the corresponding target position. That is, every time the control device 40 selects the nozzle N for discharging the droplet Fb based on the discharge control signal SI and the landing position P corresponding to the selected nozzle N is located at the target position, the target position A droplet Fb is discharged toward the surface. The ejected droplets Fb land on corresponding target positions on the pattern formation surface 4Sa.

  The droplet Fb that reaches the target position moves by the irradiation standby distance WF in the scanning direction and reaches the corresponding irradiation position Pe after the irradiation standby time T has elapsed from the time of landing by scanning the green sheet 4S by the control device 40. To do. The droplet Fb that reaches the irradiation position Pe has a hemispherical shape centered on the irradiation position Pe. Then, the laser beam Le enters the droplet Fb reaching the irradiation position Pe from the end in the anti-scanning direction toward the irradiation position Pe.

  Since the “incident angle” of the laser beam Le incident on the droplet Fb is approximately 0 °, most of the laser beam Le is transmitted through the droplet Fb and absorbed. As a result, the absorption rate of the laser beam Le incident on the droplet Fb can be improved, and the corresponding droplet Fb is reliably dried to form a layer pattern FP that is not insufficiently dried. Thereafter, similarly, the layer pattern FP is sequentially laminated, whereby the wiring pattern 6F can be formed, and the formation defects can be reduced.

Next, effects of the present embodiment configured as described above will be described below.
(1) According to the above embodiment, the reflection mirror 27 mounted on the carriage 20 guides the laser light Le emitted from the semiconductor laser LD to the irradiation position Pe along the substantially tangential direction of the pattern forming surface 4Sa. Then, the control device 40 scans the droplet Fb landed on the pattern formation surface 4Sa along the scanning direction, and makes the laser beam Le enter the end of the droplet Fb located at the irradiation position Pe.

  Therefore, the angle (“incident angle”) formed by the incident direction of the laser light Le incident on the droplet Fb and the normal direction of the corresponding droplet surface can be reduced. As a result, the laser beam Le incident on the droplet Fb can reduce the amount of reflection on the droplet surface and improve the absorption efficiency of the laser beam with respect to the droplet. Therefore, it is possible to improve the drying efficiency of the droplets and reduce the formation failure of the pattern composed of the droplets.

  (2) According to the above embodiment, when the control device 40 scans the droplet Fb that has landed on the pattern formation surface 4Sa along the scanning direction, and the droplet Fb has a hemispherical shape, The laser beam Le is incident on the end.

  Therefore, the angle formed by the incident direction of the laser beam Le incident on the droplet Fb and the normal direction of the corresponding droplet surface can be further reduced. As a result, the drying efficiency of the droplets can be further improved, and the formation failure of the pattern composed of droplets can be further reduced.

(3) According to the above embodiment, the reflection mirror 27 mounted on the carriage 20 guides the laser beam Le emitted from the semiconductor laser LD to the irradiation position Pe on the pattern forming surface 4Sa. Then, the control device 40 scans the droplet Fb landed on the pattern formation surface 4Sa along the scanning direction, and at the timing when the droplet Fb has a hemispherical shape, the center of the droplet Fb is set to the irradiation position Pe. .

  Therefore, the angle (“incident angle”) formed by the incident direction of the laser light Le incident on the droplet Fb and the normal direction of the corresponding droplet surface can be set to approximately 0 °. As a result, the laser beam Le incident on the droplet Fb can reduce the amount of reflection on the droplet surface and improve the absorption efficiency of the laser beam with respect to the droplet. Therefore, it is possible to improve the drying efficiency of the droplets and reduce the formation failure of the pattern composed of the droplets.

  (4) According to the above-described embodiment, the reflection mirror 27 reflects the laser light Le emitted from the semiconductor laser LD along the substantially tangential direction of the pattern formation surface 4Sa. Therefore, even when the irradiation position Pe is located immediately below the ejection head 21, the laser beam Le can be guided to the irradiation position Pe. As a result, the droplet Fb immediately after landing can be dried, and the degree of freedom in the shape and size of various patterns can be increased.

  (5) According to the above embodiment, the carriage 20 mounts the ejection head 21, the semiconductor laser LD, the cylindrical lens 25, and the reflection mirror 27. Therefore, the relative position of the laser beam Le with respect to the landed droplet Fb can be maintained. As a result, the laser beam Le can be incident on the end of the droplet Fb with higher reproducibility. Further, the laser beam Le can be guided to the center of the droplet Fb having a hemispherical shape with higher reproducibility. As a result, the dry state of the element pattern 5F and the wiring pattern 6F can be stabilized, and the formation defects of the circuit element 5 and the internal wiring 6 can be further reduced.

In addition, you may change the said embodiment as follows.
In the above embodiment, the laser light Le is configured to enter from the end of the droplet Fb toward the center of the droplet Fb. For example, the laser beam Le may be incident from the end of the droplet Fb toward the inside other than the center of the droplet Fb. That is, the laser beam Le along the substantially tangential direction of the pattern forming surface 4Sa may be configured to enter the end portion of the droplet Fb.

  In the above embodiment, the laser beam Le along the substantially tangential direction of the pattern forming surface 4Sa is configured to enter the end of the droplet Fb. However, the present invention is not limited to this, and if the laser light Le is incident toward the center of the droplet Fb having a hemispherical shape, the incident direction and the incident position are substantially the tangential direction of the pattern forming surface 4Sa and the droplet Fb, respectively. It is not limited to the center.

  In the above embodiment, the laser irradiation means is disposed in the Y arrow direction of the droplet discharge head, and the laser beam Le is irradiated only along the substantially Y arrow direction. For example, a pair of laser irradiation means (semiconductor laser LD, cylindrical lens 25, and reflection mirror 27) centered on the ejection head 21 are arranged on the Y arrow direction side and the anti-Y arrow direction side of the carriage 20, for example. You may make it the structure to mount. And you may make it the structure which irradiates the laser beam Le which follows a substantially Y arrow direction, and the laser beam Le which follows a substantially anti-Y arrow direction toward each different droplet Fb.

  At this time, when the controller 40 scans the landed droplet Fb along the Y arrow direction, the control device 40 emits the laser beam Le along the Y arrow direction toward the droplet Fb (the center position). A configuration for selective irradiation is preferable. In addition, when the controller 40 scans the landed droplet Fb along the anti-Y arrow direction, the control device 40 selects the laser light Le along the substantially anti-Y arrow direction toward the droplet Fb (center position). The structure to irradiate is preferable.

  According to this, the landed droplet Fb (substrate) can be relatively scanned in both the Y arrow direction and the counter Y arrow direction. In addition, the laser beam Le in the substantially same direction as the scanning direction of the droplet Fb can be incident on the end of each droplet Fb. As a result, the drying efficiency of the droplets Fb can be improved with higher reproducibility, and the formation failure of the pattern composed of droplets can be more reliably reduced.

  In the above embodiment, each droplet Fb is configured to be dried by the common laser beam Le. For example, the laser beam Le emitted from the semiconductor laser LD may be divided so as to correspond to each nozzle N, and each divided laser beam Le may be irradiated only with the corresponding droplet Fb.

  Alternatively, a configuration may be adopted in which the semiconductor lasers LD are arranged in the number corresponding to the number of the nozzles N, and the laser light Le from each semiconductor laser LD is irradiated to the corresponding droplet Fb region. At this time, the control device 40, the semiconductor laser drive circuit 44, and the ejection head drive circuit 45 are preferably configured as follows.

  That is, as shown in FIG. 8, the control device 40 outputs the semiconductor laser drive voltage COM2 for driving each semiconductor laser LD to the semiconductor laser drive circuit 44 in synchronization with the ejection timing signal LP. The ejection head drive circuit 45 sequentially outputs the latched ejection control signal SI to a delay circuit 44 a provided in the semiconductor laser drive circuit 44. The semiconductor laser driving circuit 44 receives the ejection control signal SI from the ejection head driving circuit 45 by the delay circuit 44a and waits until the droplet Fb ejected based on the ejection control signal SI reaches the irradiation position Pe. Then, at the timing when the droplet Fb reaches the irradiation position Pe, the semiconductor laser drive voltage COM2 is supplied to each semiconductor laser LD selected based on the ejection control signal SI. According to this, since the laser beam Le is irradiated only on the landed droplet Fb, the utilization efficiency of the laser beam Le can be improved.

  In the above embodiment, the droplet Fb is dried by the laser beam Le. However, the configuration is not limited thereto, and the droplet Fb may be dried and fired by the laser beam Le. According to this, the firing failure of the element pattern 5F and the wiring pattern 6F can be reduced by the laser light Le irradiated locally.

  In the above embodiment, the bitmap data BMD is generated based on the drawing information Ia. However, the present invention is not limited to this, and the bitmap data BMD previously generated by the external device may be input from the input device 41 to the control device 40.

  In the above embodiment, the laser beam Le from the semiconductor laser LD is configured to irradiate the region of the droplet Fb via the galvanomirror. Not limited to this, the laser beam Le from the semiconductor laser LD may irradiate the region of the droplet Fb via the prism mirror, or the laser beam Le emitted from the cylindrical lens 25 may be directly applied to the droplet Fb. The structure which irradiates may be sufficient.

  In the above embodiment, the droplet discharge head is embodied as the piezoelectric element drive type droplet discharge head 21. However, the present invention is not limited to this, and the droplet discharge head may be embodied as a resistance heating type or electrostatic drive type discharge head.

  In the above embodiment, all the circuit elements 5 and the internal wiring 6 are formed by the ink jet method. However, the present invention is not limited to this, and only a relatively fine circuit element 5 or internal wiring 6 may be formed by the ink jet method described above.

  In the above embodiment, the pattern forming material is embodied in metal ink. For example, the pattern forming material may be embodied as a liquid material in which an insulating film material or an organic material is dispersed. That is, the pattern forming material may be any material that is dried by receiving laser light and forms a solid phase pattern.

  In the above embodiment, the pattern is embodied as the element pattern 5F and the wiring pattern 6F. However, the present invention is not limited to this, and the pattern may be embodied in various metal wirings provided in a liquid crystal display device, an organic electroluminescence display device, a field effect display device (FED, SED, etc.) provided with a planar electron-emitting device. Good. Alternatively, the pattern may be embodied as an identification code composed of a plurality of line patterns or dot patterns. That is, the pattern may be a solid phase pattern formed by dry droplets.

The perspective view which shows the circuit module of this invention. Similarly, explanatory drawing explaining the manufacturing method of a circuit module. Similarly, a perspective view showing a droplet discharge device. Similarly, a perspective view showing a droplet discharge head. Similarly, an explanatory view explaining a droplet discharge head. Similarly, an explanatory view for explaining a semiconductor laser. Similarly, the electric block circuit diagram explaining the electrical constitution of a droplet discharge device. The electric block circuit diagram explaining the electric constitution of the droplet discharge apparatus of the example of a change.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Circuit module, 4S ... Green sheet as a board | substrate, 5 ... Circuit element, 5F ... Element pattern which comprises pattern, 6 ... Internal wiring as metal wiring, 6F ... Wiring pattern which comprises pattern, 10 ... Droplet discharge Device: 13 ... Stage as scanning means, 20 ... Carriage, 21 ... Droplet ejection head, 40 ... Control device as control means, F ... Metal ink as pattern forming material, Fb ... Droplet, Le ... Laser light, LD: a semiconductor laser constituting laser irradiation means, Pe: irradiation position.

Claims (12)

In a pattern forming method in which a pattern forming material is discharged onto a substrate as droplets, and the droplets landed on the substrate are dried to form a pattern of the droplets on the substrate.
A pattern forming method comprising: irradiating an end portion of the droplet landed on the substrate with laser light along a substantially tangential direction of the substrate to dry the droplet. In a pattern forming method in which a pattern forming material is discharged onto a substrate as droplets, and the droplets landed on the substrate are dried to form a pattern of the droplets on the substrate.
A pattern forming method comprising: irradiating a laser beam toward the center of a droplet when the droplet landed on the substrate has a hemispherical shape to dry the droplet. In the pattern formation method of Claim 2,
A pattern forming method, wherein the droplet is dried by irradiating a laser beam along a substantially tangential direction of the substrate toward a center of the droplet. In a droplet discharge apparatus equipped with a droplet discharge head for discharging a pattern forming material to a substrate as a droplet,
Laser irradiation means for irradiating the substrate with laser light along a substantially tangential direction of the substrate;
Scanning means for scanning the substrate relative to the droplet discharge head and the laser irradiation means along one direction;
Control means for driving and controlling the scanning means so that the end of the droplet landed on the substrate is positioned in the region of the laser beam;
A droplet discharge apparatus comprising: The droplet discharge device according to claim 4,
The scanning means relatively scans the substrate along the direction opposite to the one direction;
The laser irradiation means irradiates the substrate with laser light along substantially the one direction and substantially opposite to the one direction,
When the control means moves the droplet landed on the substrate relative to the laser irradiation means along the one direction, the end of the droplet is a region of the laser light substantially along the one direction. When the liquid droplets landed on the substrate are moved relative to the laser irradiation unit along the opposite direction of the one direction. The droplet discharge apparatus characterized in that the scanning means is driven and controlled so that is positioned in a laser light region along a direction substantially opposite to the one direction. In the droplet discharge device according to claim 4 or 5,
The control means drives and controls the scanning means so that an end portion of the droplet is positioned in the region of the laser beam when the droplet landed on the substrate has a hemispherical shape. Droplet discharge device. In a droplet discharge apparatus equipped with a droplet discharge head for discharging a pattern forming material to a substrate as a droplet,
Laser irradiation means for irradiating a laser beam toward the substrate;
Scanning means for scanning the substrate relative to the droplet discharge head and the laser irradiation means along one direction;
Control means for driving and controlling the scanning means so that the center of the droplet is positioned at the irradiation position of the laser beam when the droplet landed on the substrate has a hemispherical shape;
A droplet discharge apparatus comprising: In the droplet discharge device according to claim 7,
The liquid droplet ejection apparatus, wherein the laser irradiation unit irradiates a laser beam along a substantially tangential direction of the substrate. In the droplet discharge device according to claim 7 or 8,
The scanning means relatively scans the substrate along the direction opposite to the one direction;
The laser irradiation means irradiates the substrate with laser light along substantially the one direction and substantially opposite to the one direction,
When the control means moves the droplet landed on the substrate relative to the laser irradiation means along the one direction, the position of the laser light irradiation center of the droplet substantially along the one direction. The scanning means is driven and controlled so that the liquid droplets landed on the substrate move relative to the laser irradiation means along the direction opposite to the one direction. A liquid droplet ejection apparatus, wherein the scanning unit is driven and controlled so as to be positioned at a laser beam irradiation position along a direction substantially opposite to the one direction. In the droplet discharge device according to any one of claims 4 to 9,
A carriage on which the droplet discharge head is mounted;
The laser irradiation means includes
A semiconductor laser mounted on the carriage and emitting the laser beam;
An irradiation optical system for irradiating the droplets with laser light emitted from the semiconductor laser mounted on the carriage;
A droplet discharge apparatus comprising: In the droplet discharge device according to any one of claims 4 to 10,
The pattern forming material is a metal ink in which metal fine particles are dispersed,
The droplet discharge device, wherein the substrate is a low-temperature fired ceramic substrate. In a circuit module comprising a substrate, a circuit element formed on the substrate, and a metal wiring formed on the substrate and electrically connected to the circuit element,
The circuit module, wherein the metal wiring is formed by the droplet discharge device according to any one of claims 4 to 11.

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