JP2008066526A - Pattern forming method, manufacturing method of circuit module, droplet discharging device, circuit module, and circuit module manufacturing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pattern forming method for increasing the density of a pattern formed of droplets, to provide a manufacturing method of a circuit module, to provide a droplet discharging device, to provide the circuit module, and to provide a circuit module manufacturing device. <P>SOLUTION: Metal ink is made into droplets Fb and they are discharged to a unit irradiation region S1. The region of the droplets Fb reaching the unit irradiation region S1 is irradiated with a pinning laser L1 for pinning the droplets Fb along an almost tangential direction of a discharge face 4Ga. Then, the region of the droplets Fb is irradiated with a pre-drying laser L2 for preliminarily drying the droplets Fb, which has higher energy than the pinning laser L1, along the almost tangential direction of the discharge face 4Ga. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

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

Generally, a low-temperature fired ceramic multilayer substrate (LTCC: Low Temperature Co-fired Ceramics multilayer substrate) using glass ceramic is known as a circuit module 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 the multilayer substrate, a wiring pattern is drawn on each green sheet before lamination using a metal paste or metal ink. For this drawing method, a so-called ink jet method is used in which metal ink is discharged as fine droplets (for example, Patent Document 1 and Patent Document 2). In the ink jet method, the discharged droplets are joined to draw a wiring pattern. Therefore, it is possible to quickly cope with a change in the shape of the wiring pattern.
JP 2003-318542 A JP 2005-57139 A

  In the ink jet method, when the wiring pattern is densified or narrowed, it is necessary to suppress (pinning) the wetting and spreading of the droplet immediately after landing (for example, within several tens of microseconds after landing). is there. However, in the ink jet method, since the droplets are dried using a drying furnace or the like, the landed droplets spread and get wet during the drying process to increase the size of the droplets. For this reason, in the said inkjet method, there existed a limit in the density increase and narrowing of a wiring pattern.

  It is considered that such a problem can be solved by irradiating a droplet immediately after landing with a laser and pinning the droplet immediately after landing. However, if the intensity of the irradiating laser is too strong, the landed droplets are rapidly heated and scattered easily. On the other hand, if the intensity of the irradiating laser is too weak, it is easy to combine the pinned droplets with the overstrike droplets when ejecting additional droplets onto the pinned droplets (overstrike). Spread wet.

  The present invention has been made to solve the above-described problems, and its object is to produce a pattern forming method, a droplet discharge device, a circuit module, and a circuit module that enable a high-density pattern of droplets. It is to provide a method and a circuit module manufacturing apparatus.

  The pattern forming method of the present invention includes a droplet discharge step of discharging a droplet of a pattern forming liquid onto a substrate, and a first laser beam on the substrate before the droplet that has landed on the substrate spreads to a predetermined size. A first laser irradiation step of irradiating along a substantially tangential direction and fixing the droplet at a landing position of the droplet, and a second laser having higher energy than the first laser on the fixed droplet And a second laser irradiation step of irradiating along the substantially normal direction of the substrate and pre-drying the droplets.

  According to the pattern forming method of the present invention, it is possible to irradiate a droplet region with lasers having different intensities under irradiation positions, irradiation directions, and irradiation timings according to the intensity. In other words, the first laser along the substantially tangential direction of the substrate can prevent the droplet from abruptly rising in temperature and avoid the scattering of the droplet, and can suppress the spreading of the droplet immediately after landing. It can be fixed (pinned). In addition, the pinned droplet can be pre-dried by the second laser along the substantially normal direction of the substrate, and overstrike to the droplet can be allowed. Therefore, it is possible to increase the density of the pattern made of droplets.

  According to another aspect of the present invention, there is provided a circuit module manufacturing method comprising: a droplet discharge step of discharging a metal ink droplet onto a substrate; and the first laser is applied to the substrate before the droplet that has landed on the substrate spreads out to a predetermined size. First laser irradiation step of irradiating along the substantially tangential direction and fixing the droplet at the landing position of the droplet, and a second laser having higher energy than the first laser in the fixed droplet And a second laser irradiation step of preliminarily drying the droplets.

  According to the method for manufacturing a circuit module of the present invention, it is possible to increase the density of a pattern formed by droplets.

  The droplet discharge device of the present invention includes a carriage, a relative movement unit that relatively moves the substrate in one direction with respect to the carriage, and a droplet that is mounted on the carriage and discharges a droplet of a pattern forming liquid onto the substrate. An ejection head; and a first laser irradiation unit that is mounted on the carriage and irradiates a region of the droplet landed on the substrate along a substantially tangential direction of the substrate, and fixes the droplet. A second laser mounted on the carriage and having an energy higher than that of the first laser is applied to the fixed droplet region along a substantially normal direction of the substrate to preliminarily dry the droplet. A second laser irradiation means.

  According to the droplet discharge device of the present invention, the first laser irradiation unit and the second laser irradiation unit are configured to apply lasers having different intensities to droplet regions under irradiation positions, irradiation directions, and irradiation timings according to the intensity. Irradiate. That is, the first laser irradiating means can prevent the droplet from scattering by suppressing the rapid temperature rise of the droplet by the first laser along the substantially tangential direction of the substrate. It is possible to fix (pinning) while suppressing the spread of wetting. Further, the second laser irradiation means can pre-dry the pinned droplets by the second laser along the substantially normal direction of the substrate, and can allow overstrike to the droplets. Therefore, it is possible to increase the density of the pattern made of droplets.

  The droplet discharge device includes a laser light source that emits a laser, and a dividing unit that divides the laser from the laser light source, wherein the first laser irradiation unit transmits one of the lasers divided by the dividing unit. A first optical system that irradiates the region of the droplet as a first laser, wherein the second laser irradiation unit uses the other laser divided by the dividing unit as the second laser to The configuration may include a second optical system that irradiates the region.

  According to this droplet discharge device, both the first laser and the second laser can be irradiated by a common laser light source. Therefore, the number of laser light sources can be reduced, and the droplet discharge device can be reduced in size and cost.

  In the liquid droplet ejection apparatus, the relative movement unit is a stage that reciprocates the substrate, and the first laser irradiation unit and the second laser irradiation unit are respectively a forward movement direction and a return direction of the liquid droplet discharge head. A configuration arranged in the moving direction is preferable.

According to this droplet discharge device, the droplet that has landed on the substrate is irradiated with the first laser and the second laser in at least one of the forward movement direction and the backward movement direction of the droplet discharge head. Therefore, it is possible to increase the density of the pattern composed of droplets regardless of the reciprocation of the stage.

  In this droplet discharge apparatus, the carriage includes a plurality of droplet discharge heads and a plurality of second laser irradiation units corresponding to the plurality of droplet discharge heads, and the plurality of droplet discharge units. The heads are arranged with a predetermined pitch width along the one direction, and each of the plurality of second laser irradiation means is arranged with the same pitch width as the pitch width of the droplet discharge head in the one direction. It may be a configuration.

  According to this droplet discharge device, the distance between each droplet discharge head and the second laser irradiation means corresponding to the droplet discharge head is kept constant in one direction. Therefore, the droplets ejected from each of the plurality of droplet ejection heads receive the corresponding second laser with the same elapsed time from the landing time. Therefore, the pre-dried state of each droplet can be made the same, and the uniformity of the densified pattern can be ensured.

  In this droplet discharge apparatus, each of the plurality of second laser irradiation units is preferably arranged between the adjacent droplet discharge heads when viewed from the normal direction of the substrate.

  According to this droplet discharge device, the second laser is irradiated from a region between adjacent droplet discharge heads. Therefore, the irradiation interval of the second laser can be shortened, and the waiting time of the pinned droplets can be shortened. Therefore, the landed droplets can be dried more reliably in the pinned state.

  In this droplet discharge apparatus, it is preferable that the width of the second laser irradiation unit in the one direction is smaller than the width of the droplet discharge head in the one direction.

  According to this droplet discharge device, a plurality of droplet discharge heads can be brought close to each other in one direction. Therefore, the second laser irradiation means can be arranged without reducing the degree of freedom in arranging the droplet discharge heads.

  In the liquid droplet ejection apparatus, the carriage includes a plurality of liquid droplet ejection heads, the plurality of liquid droplet ejection heads are arranged along the other direction, and the second laser irradiation unit includes the other direction. It is preferable to irradiate the second laser common to the droplets from the droplet discharge heads adjacent to each other.

  According to this droplet discharge device, the droplet discharge heads adjacent in the other direction share the second laser irradiation means. Therefore, the number of second laser irradiation means can be reduced, and the pattern can be easily densified with a simpler configuration.

  In the liquid droplet ejection apparatus, it is preferable that the liquid droplet ejection head is disposed between the substrate and the second laser irradiation unit when viewed from the tangential direction of the substrate.

  According to this droplet discharge device, the droplet discharge head and the second laser irradiation unit can be separated in the normal direction of the substrate. Therefore, the degree of freedom in design of the droplet discharge head and the second laser irradiation unit can be expanded by the distance between the droplet discharge head and the second laser irradiation unit.

  In this droplet discharge apparatus, the droplet discharge head preferably has a flow path extending in a normal direction of the substrate.

  According to this droplet discharge device, the flow path of the droplet discharge head is disposed in parallel with the second laser. Therefore, interference between the second laser and the flow path can be avoided more reliably.

  In this droplet discharge device, the droplet preferably has a surfactant that repels other droplets in a pre-dried state.

  According to this droplet discharge device, the pre-dried droplets suppress the wetting and spreading of the overlapping droplets. Therefore, it is possible to easily increase the thickness of the pattern having a higher density.

  The circuit module of the present invention is a circuit module comprising a substrate, a circuit element formed on the substrate, and a wiring formed on the substrate and electrically connected to the circuit element. It was formed by the droplet discharge device.

  According to the circuit module of the present invention, a circuit module having high-density wiring can be provided.

  The circuit module manufacturing apparatus of the present invention includes a carriage, relative movement means for moving the substrate in one direction relative to the carriage, and a droplet that is mounted on the carriage and discharges a droplet of a pattern forming liquid onto the substrate. An ejection head; and a first laser irradiation unit that is mounted on the carriage and irradiates a region of the droplet landed on the substrate along a substantially tangential direction of the substrate, and fixes the droplet. A second laser mounted on the carriage and having an energy higher than that of the first laser is applied to the fixed droplet region along a substantially normal direction of the substrate to preliminarily dry the droplet. A second laser irradiation means.

  According to the circuit module manufacturing apparatus of the present invention, a circuit module having a high density pattern can be manufactured.

(First embodiment)
Hereinafter, a first embodiment of 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 semiconductor chip 3 connected to the upper side of the LTCC multilayer substrate 2 by wire bonding.

  The LTCC multilayer substrate 2 is a laminate of a plurality of LTCC substrates 4 formed in a sheet shape. Each LTCC substrate 4 is a sintered body 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.

  Each LTCC substrate 4 has various circuit elements 5 such as a resistance element, a capacitor element, and a coil element, an internal wiring 6 that electrically connects each circuit element 5, a predetermined structure that exhibits a stack via structure and a thermal via structure. A plurality of via holes 7 having a hole diameter (for example, 20 μm) and via wirings 8 filled in the via holes 7 are formed.

Each internal wiring 6 (region with gradation in FIG. 1) is a sintered body of metal fine particles such as silver or a silver alloy, and is formed by a pattern forming method using the droplet discharge device of the present invention. . A position on the LTCC substrate 4 where each internal wiring 6 is formed is a target formation position.

  Next, a droplet discharge device 10 for manufacturing the LTCC multilayer substrate 2 will be described with reference to FIGS. FIG. 2 is an overall perspective view illustrating the droplet discharge device 10. 3 to 6 are views for explaining the droplet discharge head 20.

  In FIG. 2, the droplet discharge device 10 has 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 relative moving means that moves along the guide groove 12 in the Y arrow direction and the counter-Y arrow direction. A placement unit 14 is formed on the upper surface of the stage 13 to place the LTCC substrate 4 (hereinafter simply referred to as a green sheet 4G) before firing. The placement unit 14 positions and fixes the placed green sheet 4G with respect to the stage 13, and conveys the green sheet 4G in the Y arrow direction (forward movement direction) and the anti-Y arrow direction (reverse movement direction). To do.

  The green sheet 4G has a high reflectance with respect to a laser having a wavelength of 400 nm to 1200 nm (visible region or near infrared region: hereinafter simply referred to as a selected wavelength). When the green sheet 4G receives a laser having a selected wavelength, it reflects most of the laser and suppresses its own temperature rise.

  A gate-type guide member 15 is installed on the base 11 so as to straddle a direction (X arrow direction) orthogonal to the forward movement direction. An ink tank 16 extending in the direction of the arrow X is disposed on the upper side of the guide member 15. The ink tank 16 stores the metal ink F as a pattern forming liquid and supplies the stored metal ink F to a droplet discharge head (hereinafter simply referred to as a discharge head) 20 as a droplet discharge means at a predetermined pressure. To do.

  The metal ink F is an ink having a high absorption rate with respect to a laser having a selected wavelength. As the metal ink F, for example, a water-based metal ink in which metal fine particles (particles of Au, Ag, Ni, Mn, etc.) having a particle diameter of several nm to several tens of nm are dispersed in an aqueous solvent can be used.

  The metal ink F contains a surfactant that exhibits liquid repellency with respect to the metal ink F in a dry state. That is, the dried metal ink F repels the overprinted metal ink F and suppresses the wetting and spreading of the overprinted metal ink F. Surfactants include acetylene glycol surfactants (for example, Surfynol 104PG (2,4,7,9-tetramethyl-5-decyne-4,7 manufactured by Air Products and Chemicals, Inc.). Diol (Surfinol: registered trademark)) can be used.

  When the metal ink F receives a laser of a selected wavelength at a predetermined intensity, the energy of the laser is converted into the heat energy of the metal ink F without causing a sharp temperature rise, and a part of the solvent or dispersion medium is evaporated. Thicken the outer edge of the surface. The thickened metal ink F at the outer edge stops (pins) its own wetting and spreading along the surface direction of the green sheet 4G. The metal ink F in the pinned state receives a laser having a weak enough intensity to avoid scattering of the metal ink F, but easily merges with the metal ink F that has been struck and overflows from the pinned region. Spreads wet.

In this embodiment, the intensity of the laser for pinning the metal ink F is set to pinning intensity (for example, 50 mW / mm ² ).

When the metal ink F receives a laser of a selected wavelength with an intensity stronger than the pinning intensity, the metal ink F effectively absorbs the energy of the laser and converts it into thermal energy, and evaporates part of the solvent or dispersion medium to preliminarily. Dry (pre-dry). The preliminarily dried metal ink F is:
The time until the overprinted metal ink F leaks from the pinned region is made sufficiently long (longer than the drying time including natural drying).

In the present embodiment, the intensity of the laser for predrying the metal ink F is set to a predrying intensity (for example, 150 mW / mm ² ).

  The guide member 15 is formed with a pair of upper and lower guide rails 18 extending in the X arrow direction over substantially the entire width in the X arrow direction. A pair of upper and lower guide rails 18 is attached with a carriage 19 having a U-shape when viewed from the X arrow direction. The carriage 19 is guided by the guide rail 18 and moves in the X arrow direction and the counter X arrow direction.

  The bottom piece 19a of the carriage 19 is formed with a pair of rectangular holes (irradiation holes 19h) that extend in the vertical direction and extend in the X arrow direction. Four droplet discharge heads (hereinafter simply referred to as discharge heads) 20 are disposed on the bottom piece 19a of the carriage 19 between the pair of irradiation holes 19h. Also, a pair of pinning laser heads PL as first laser irradiation means are disposed on both side ends of the bottom piece 19a of the carriage 19 in the Y-arrow direction. Furthermore, a pair of preliminary drying laser heads DL as second laser irradiation means are disposed on the upper piece 19b of the carriage 19 at positions opposite to the pair of irradiation holes 19h.

  FIG. 3 is a view of each ejection head 20 as viewed from the green sheet 4G side (lower side), and is a view for explaining an arrangement position of each ejection head 20. FIG. It is principal part sectional drawing for demonstrating.

  3 and 4, a nozzle plate 21 is provided below each discharge head 20. A nozzle forming surface 21a substantially parallel to the green sheet 4G is formed on one side surface of the nozzle plate 21 that faces the green sheet 4G. When the green sheet 4G is positioned directly below the ejection head 20, the nozzle plate 21 holds the distance (platen gap) between the nozzle forming surface 21a and the green sheet 4G at a predetermined distance (for example, 600 μm).

  In FIG. 3, each nozzle plate 21 is formed with a pair of nozzle rows NL made up of a plurality of nozzles N arranged along the direction of the X arrow. In each nozzle row NL, 180 nozzles N are formed per inch. In FIG. 4, for convenience of explanation, only 10 nozzles N are shown per row.

  In the pair of nozzle rows NL, each nozzle N of one nozzle row NL interpolates between the nozzles N of the other nozzle row NL when viewed from the direction of the arrow Y (forward movement direction). That is, each ejection head 20 has 180 × 2 = 360 nozzles N per inch when viewed from the forward movement direction (maximum resolution is 360 dpi).

  Further, in the pair of ejection heads 20 (ejection head pair 20P) provided in the forward movement direction, each nozzle N of one ejection head 20 is located between each nozzle of the other ejection head 20 as viewed from the forward movement direction. Is interpolated. That is, each pair of ejection heads 20 </ b> P has 360 × 2 = 720 nozzles N per inch when viewed from the forward movement direction. Accordingly, the droplet discharge device 10 is configured so that the maximum resolution is 720 dpi.

  In the present embodiment, an area on the green sheet 4G and surrounded by a position facing each nozzle N of the ejection head pair 20P is defined as a unit irradiation area S1.

  In FIG. 4, a supply tube 20 </ b> T as a flow path is connected to the upper side of the ejection head 20. The supply tube 20 </ b> T is disposed so as to extend upward in the vertical direction, and supplies the metal ink F from the ink tank 16 to the inside of the ejection head 20.

  On the upper side of the nozzle N, a cavity 22 communicating with the supply tube 20T is formed. The cavity 22 accommodates the metal ink F from the supply tube 20T and supplies the metal ink F to the corresponding nozzle N. On the upper side of the cavity 22 is attached a vibration plate 23 that vibrates in the vertical direction and expands and contracts the volume in the cavity 22. A piezoelectric element PZ corresponding to the nozzle N is disposed on the upper side of the vibration plate 23. The piezoelectric element PZ contracts and expands in the vertical direction to vibrate the diaphragm 23 in the vertical direction. The vibration plate 23 that vibrates in the vertical direction causes the metal ink F to be ejected from the corresponding nozzles N as droplets Fb of a predetermined size. The discharged droplet Fb flies in the direction opposite to the Z arrow of the corresponding nozzle N, and lands on the upper surface (discharge surface 4Ga) of the green sheet 4G.

  FIG. 5A and FIG. 5B are views of the respective ejection head pairs 20P as viewed from the lower side and the side opposite to the X arrow direction, the ejection head pairs 20P, the pinning laser head PL, and the preliminary drying. It is a figure for demonstrating the arrangement position of laser head DL.

  In FIG. 5, a pinning laser head PL is provided in each of the ejection head pair 20P in the forward and backward directions. Each of the pinning laser heads PL is disposed symmetrically with respect to the corresponding ejection head pair 20P when viewed from the lower side. Each pinning laser head PL emits a laser light source (for example, a semiconductor laser) that emits a laser having a selected wavelength (for example, 808 nm) and a laser from the laser light source along a substantially tangential direction of the ejection surface 4Ga. An irradiation optical system.

  Each pinning laser head PL irradiates a laser in accordance with the reciprocation of the green sheet 4G. That is, as shown in FIG. 5, when the green sheet 4G is moved forward, the pinning laser head PL positioned in the forward movement direction of the discharge head pair 20P is placed in the unit irradiation region S1 of the corresponding discharge head pair 20P. A laser (pinning laser L1 as a first laser: a thin line in FIG. 5) is irradiated. On the contrary, as shown in FIG. 6, the pinning laser heads PL positioned in the backward movement direction of the ejection head pair 20P are unit irradiation regions S1 of the corresponding ejection head pair 20P when the green sheet 4G is moved backward. A pinning laser L1 (thin line in FIG. 6) is irradiated toward

  Each of the pinning laser heads PL irradiates the unit irradiation region S1 with the pinning laser L1, and a beam spot of pinning intensity over the entire unit irradiation region S1 (region with gradation of FIG. 5A: pinning). Spot). The intensity of the pinning spot is made uniform as much as the pinning laser L1 is irradiated along the substantially tangential direction of the ejection surface 4Ga.

  Each droplet Fb that lands on the unit irradiation region S1 (pinning spot) converts the energy of the pinning laser L1 into the thermal energy of the metal ink F, and evaporates a part of the solvent or dispersion medium to increase the viscosity. In other words, the droplets Fb that land on the unit irradiation region S1 evaporate part of their solvent or dispersion medium instantaneously and substantially stop the wetting and spreading along the surface direction of the ejection surface 4Ga (pinned). )

Accordingly, each pinning laser head PL can always form a uniform pinning spot over the entire unit irradiation region S1 regardless of the reciprocation of the green sheet 4G. The droplet discharge device 10 can maintain the droplet diameter immediately after landing on the landed droplet Fb, and can surely avoid scattering of the landed droplet Fb. In addition, since the droplet discharge device 10 uses a laser having a high reflectance with respect to the green sheet 4G as the pinning laser L1, thermal damage to the green sheet 4G can be reduced.

  In FIG. 5, a preliminary drying laser head DL is disposed between each ejection head pair 20P and a pinning laser head PL corresponding to each ejection head pair 20P. Each pre-drying laser head DL is arranged symmetrically with respect to the corresponding ejection head pair 20 </ b> P when viewed from the lower side. Each pre-drying laser head DL is disposed on the upper side in the forward movement direction or on the upper side in the backward movement direction of the ejection head pair 20P, and the degree of freedom of its own arrangement position and the arrangement position of each ejection head pair 20P is two-dimensionally ( (Discharge surface 4Ga direction). Thus, each preliminary drying laser head DL can avoid physical interference with the ejection head pair 20P and the supply tube 20T.

  Each predrying laser head DL has a laser light source (for example, a semiconductor laser) that emits a laser having a selected wavelength (for example, 808 nm) and a laser from the laser light source along a substantially normal direction of the ejection surface 4Ga. And an irradiation optical system for irradiation.

  Each pre-drying laser head DL irradiates a laser according to the reciprocation of the green sheet 4G, similarly to the pinning laser head PL. That is, as shown in FIG. 5, when the green sheet 4G is moved forward, the preliminary drying laser head DL positioned in the forward movement direction of the discharge head pair 20P is respectively in the forward movement direction side of the corresponding discharge head pair 20P. Is irradiated with a laser (preliminary drying laser L2 as the second laser: thick line in FIG. 5). On the other hand, as shown in FIG. 6, the preliminary drying laser head DL positioned in the backward movement direction of the ejection head pair 20P is moved backward when the green sheet 4G is moved backward. Is irradiated with a pre-drying laser L2 (thick line in FIG. 6).

  Each preliminary drying laser head DL irradiates the preliminary drying laser L2 in the forward or backward movement direction of the corresponding unit irradiation region S1, and the preliminary drying laser head DL is opposed to substantially the entire width in the X arrow direction of the corresponding unit irradiation region S1. A dry intensity beam spot (preliminary dry spot) is formed.

  Each droplet Fb pinned in the unit irradiation region S1 passes through the preliminary drying spot by the forward or backward movement of the green sheet 4G. Each droplet Fb passing through the predrying spot is preliminarily dried by converting the energy of the predrying laser L2 into the thermal energy of the metal ink F and evaporating a part of the solvent or the dispersion medium.

  Thus, each preliminary drying laser head DL can always form a drying spot having the same intensity on the traveling direction side of the unit irradiation region S1 regardless of the reciprocation of the green sheet 4G. Then, the droplet discharge device 10 can surely perform preliminary drying without scattering the droplets Fb, and enables the droplets Fb to be overprinted. In addition, since the droplet discharge device 10 uses a laser having a high reflectance with respect to the green sheet 4G as the preliminary drying laser L2, it is possible to reduce thermal damage to the green sheet 4G.

  Next, the electrical configuration of the droplet discharge device 10 will be described with reference to FIG.

  In FIG. 7, the control device 30 includes a CPU 30A, a ROM 30B, a RAM 30C, and the like. The control device 30 performs laser irradiation of the reciprocating process of the stage 13 and the carriage 19, the droplet discharge process of the discharge head 20, the pinning laser head PL and the preliminary drying laser head DL in accordance with the stored various data and various control programs. Execute processing.

An input / output device 31 having various operation switches and a display is connected to the control device 30. The input / output device 31 displays the processing status of various processes executed by the droplet discharge device 10. The input / output device 31 inputs bitmap data BD for forming the internal wiring 6 to the control device 30.

  The bitmap data BD 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 BD is data that defines whether or not the droplets Fb are ejected to each position on the drawing plane (ejection surface 4Ga) through which the ejection head 20 (each nozzle N) passes. That is, the bitmap data BD is data for discharging the droplet Fb to the target formation position of the internal wiring 6 defined on the discharge surface 4Ga.

  An X-axis motor drive circuit 32 is connected to the control device 30. The control device 30 outputs a drive control signal corresponding to the X-axis motor drive circuit 32 to the X-axis motor drive circuit 32. In response to the drive control signal from the control device 30, the X-axis motor drive circuit 32 rotates the X-axis motor MX for moving the carriage 19 in the forward or reverse direction.

  A Y-axis motor drive circuit 33 is connected to the control device 30. The control device 30 outputs a drive control signal corresponding to the Y-axis motor drive circuit 33 to the Y-axis motor drive circuit 33. In response to the drive control signal from the control device 30, the Y axis motor drive circuit 33 rotates the Y axis motor MY for moving the stage 13 in the normal direction or the reverse direction.

  A head drive circuit 34 is connected to the control device 30. The control device 30 outputs a discharge timing signal LT synchronized with a predetermined discharge frequency to the head drive circuit 34. The control device 30 outputs a drive voltage COM for driving each piezoelectric element PZ to the head drive circuit 34 in synchronization with the ejection frequency. The control device 30 generates a discharge control signal SI synchronized with a predetermined frequency using the bitmap data BD, and serially transfers the discharge control signal SI to the head drive circuit 34. The head driving circuit 34 sequentially converts the ejection control signal SI from the control device 30 into serial / parallel conversion corresponding to each piezoelectric element PZ. Each time the head drive circuit 34 receives the ejection timing signal LT from the control device 30, the head drive circuit 34 latches the serial / parallel converted ejection control signal SI, and applies the driving voltage COM to each piezoelectric element PZ selected by the ejection control signal SI. Supply.

  A laser drive circuit 35 is connected to the control device 30. The control device 30 outputs a drive control signal corresponding to the laser drive circuit 35 to the laser drive circuit 35. The laser drive circuit 35 drives and controls the pinning laser head PL corresponding to the reciprocation of the green sheet 4G in response to a control signal from the control device 30. Further, the laser drive circuit 35 drives and controls the preliminary drying laser head DL corresponding to the reciprocation of the green sheet 4G in response to a control signal from the control device 30.

  Next, a manufacturing method of the LTCC multilayer substrate 2 using the droplet discharge device 10 will be described.

  As shown in FIG. 2, the green sheet 4G is placed on the stage 13 so that the ejection surface 4Ga is on the upper side. At this time, the stage 13 arranges the green sheet 4G in the anti-Y arrow direction of the carriage 19. From this state, the bitmap data BD is input from the input / output device 31 to the control device 30. The control device 30 stores the bitmap data BD from the input / output device 31.

Next, the control device 30 sets the carriage 19 via the X-axis motor drive circuit 32 so that each nozzle row NL passes over the target formation position of the internal wiring 6 when the green sheet 4G is moved forward. . When the carriage 19 is set, the control device 30 starts the forward movement of the green sheet 4G via the Y-axis motor drive circuit 33.

  When starting the forward movement of the green sheet 4G, the control device 30 selectively drives the pinning laser head PL positioned in the forward movement direction of the ejection head pair 20P via the laser driving circuit 35 to irradiate the pinning laser L1. To start. In addition, when starting the forward movement of the green sheet 4G, the control device 30 selectively drives the preliminary drying laser head DL positioned in the forward movement direction of the ejection head pair 20P to start irradiation of the preliminary drying laser L2.

  Further, when the forward movement of the green sheet 4G is started, the control device 30 generates an ejection control signal SI using the bitmap data BD, and transfers the ejection control signal SI and the driving voltage COM to the head driving circuit 34. Then, every time the target formation position of the internal wiring 6 is located immediately below the nozzle row NL, the control device 30 drives and controls each piezoelectric element PZ via the head drive circuit 34 to drop droplets on the selected nozzle N. Fb is discharged (droplet discharge step).

  Each ejected droplet Fb lands on a corresponding unit irradiation region S1, that is, a pinning spot, and receives a pinning laser L1. The droplet Fb that has received the pinning laser L1 is pinned substantially at the same time as landing and is fixed at a desired droplet diameter (first laser irradiation step).

  Each pinned droplet Fb passes through the preliminary drying spot by the forward movement of the green sheet 4G, and is preliminary dried by receiving the preliminary drying laser L2 (second laser irradiation step).

  Thereafter, in the same manner, each of the ejected droplets Fb is repeatedly irradiated with the pinning laser L1 and the preliminary drying laser L2, thereby forming the internal wiring 6 having a predetermined size.

  When the internal wiring 6 is formed on the green sheet 4G, a plurality of green sheets 4G are stacked and fired at once. Thereby, the LTCC multilayer substrate 2 having the highly densified internal wiring 6 can be formed.

  Next, the effect of 1st embodiment comprised as mentioned above is described below.

  (1) According to the first embodiment, the metal ink F is discharged as the droplet Fb to the unit irradiation region S1, and the droplet Fb is pinned to the region of the droplet Fb that has landed on the unit irradiation region S1. The pinning laser L1 was irradiated along the substantially tangential direction of the ejection surface 4Ga. Next, a predrying laser L2 for predrying the droplet Fb having a higher energy than that of the pinning laser L1 was applied to the region of the droplet Fb along the substantially normal direction of the ejection surface 4Ga.

  Therefore, the pinning laser L1 along the substantially tangential direction of the ejection surface 4Ga can suppress the rapid temperature rise of the droplet Fb to avoid the scattering of the droplet Fb, and can also prevent the droplet Fb immediately after landing. It can be fixed while suppressing wetting and spreading. Moreover, the pinned droplet Fb can be preliminarily dried by the preliminary drying laser L2 along the substantially normal direction of the ejection surface 4Ga, and overstrike to the droplet Fb can be allowed. Therefore, it is possible to increase the density of the internal wiring 6 made of the droplets Fb.

  (2) According to the first embodiment, the pinning laser head PL and the preliminary drying laser head DL are arranged in the forward and backward movement directions of the ejection head pairs 20P, respectively. When the stage 13 moves forward, the pinning laser head PL and the preliminary drying laser head DL positioned in the forward movement direction of each ejection head pair 20P are selectively driven. On the other hand, when the stage 13 is moved backward, the pinning laser head PL and the preliminary drying laser head DL positioned in the backward movement direction of each ejection head pair 20P are selectively driven.

  Accordingly, it is possible to irradiate the region of the forwardly moving droplet Fb and the region of the backwardly moving droplet Fb with the pinning laser L1 and the preliminary drying laser L2 at the same timing. As a result, regardless of the reciprocation of the stage 13, it is possible to increase the density of the pattern composed of droplets.

  (3) According to the first embodiment, each predrying laser head DL is disposed on the upper side in the forward movement direction or on the upper side in the backward movement direction of the ejection head pair 20P. Therefore, each preliminary drying laser head DL can secure the degree of freedom of its own arrangement position and the arrangement position of each ejection head pair 20P in a two-dimensional direction (surface direction of the ejection surface 4Ga). Therefore, each preliminary drying laser head DL can avoid physical interference with the ejection head pair 20P and the supply tube 20T, and can expand the degree of freedom of design of the droplet ejection device 10.

  (4) According to the first embodiment, each discharge head 20 has the supply tube 20T extending in the normal direction of the discharge surface 4Ga, and the supply system of the metal ink F is parallel to the preliminary drying laser L2. To do. Therefore, interference between the preliminary drying laser L2 and the metal ink F supply system can be avoided more reliably.

(5) According to the first embodiment, the droplet Fb includes a surfactant that repels other droplets Fb in a pre-dried state. Therefore, the preliminarily dried droplets Fb can suppress the wetting and spreading of the overstripped droplets, and can easily increase the thickness of the pattern having a high density.
(Second embodiment)
Next, a second embodiment embodying the present invention will be described with reference to FIG. In the second embodiment, the preliminary drying laser head DL in the first embodiment is changed, and the other configurations are the same as those in the first embodiment. Therefore, in the following, the pre-drying laser head DL which is a change point will be described in detail.

  In FIG. 8, the two pre-drying laser heads DL are arranged close to the forward and backward movement directions of the corresponding ejection head pair 20P. The two predrying laser heads DL irradiate the predrying laser L2 immediately before the forward movement direction and the backward movement direction of the corresponding unit irradiation region S1, respectively.

  A common preliminary drying laser head DLC is disposed between the two ejection head pairs 20P. The common pre-drying laser head DLC irradiates the pre-drying laser L2 over substantially the entire width of the two unit irradiation regions S1 in the X arrow direction when viewed from the forward movement direction (or the backward movement direction). That is, the common pre-drying laser head DLC is preliminarily moved immediately before the forward movement direction side (or the backward movement direction side) of the subsequent unit irradiation region S1 when the green sheet 4G moves forward (or backward movement). The drying laser L2 (thick line in FIG. 8) is irradiated.

  Next, the effect of 2nd embodiment comprised as mentioned above is described below.

  (6) According to the second embodiment, the common preliminary drying laser head DLC irradiates the preliminary drying laser L2 toward the region of the droplet Fb from the two ejection head pairs 20P. Therefore, the number of the preliminary drying laser heads DL can be reduced, and the density of the internal wiring 6 can be increased with a simpler configuration.

(7) Moreover, the common preliminary drying laser head DLC irradiates the preliminary drying laser L2 from between the two ejection head pairs 20P. Therefore, the preliminary drying laser L2 can be irradiated immediately before the subsequent unit irradiation region S1 in the forward movement direction (or the backward movement direction). For this reason, the waiting time of the pinned droplet Fb can be shortened, and each landed droplet Fb can be preliminarily dried in a pinned state.
(Third embodiment)
Next, a third embodiment embodying the present invention will be described with reference to FIG. In the third embodiment, the preliminary drying laser head DL in the first embodiment is changed, and the other configurations are the same as those in the first embodiment. Therefore, in the following, the pre-drying laser head DL which is a change point will be described in detail.

  In FIG. 9, a plurality of preliminary drying laser heads DL are arranged above each ejection head 20. Each pre-drying laser head DL is formed in a size in which the width in the forward direction is smaller than the width in the forward direction of the ejection head 20, and is arranged on the upper side in the forward direction and the upper side in the backward direction of each ejection head 20. ing. The preliminary drying laser heads DL are arranged such that the pitch width of the array along the forward movement direction is the same as the pitch width of the array along the forward movement direction of the ejection head 20.

  That is, each preliminary drying laser head DL is disposed in a region between adjacent ejection heads 20 when viewed from the normal direction of the ejection surface 4Ga, and the forward movement direction and the backward movement direction of each ejection head 20. The pre-drying laser L2 is irradiated immediately before.

  Next, effects of the third embodiment configured as described above will be described below.

  (8) According to the third embodiment, each preliminary drying laser head DL irradiates the preliminary drying laser L <b> 2 from between the adjacent ejection heads 20. Therefore, the preliminary drying laser L2 can be irradiated immediately before the forward movement direction (or the backward movement direction) of each ejection head 20. For this reason, the waiting time of the pinned droplet Fb can be further shortened, and each landed droplet Fb can be preliminarily dried in a pinned state.

  (9) According to the third embodiment, the preliminary drying laser heads DL are arranged so that the pitch width of the arrangement along the forward movement direction is the same as the pitch width of the arrangement along the forward movement direction of the ejection head 20. Is done. Therefore, the distance between each ejection head 20 and the preliminary drying laser head DL corresponding to the ejection head 20 is kept constant in the forward movement direction or the backward movement direction. For this reason, the droplets Fb ejected from each ejection head 20 receive the corresponding pre-drying laser L2 with the same elapsed time from landing. As a result, the preliminary drying state of each droplet Fb can be made the same, and the uniformity of the high-density internal wiring 6 can be ensured.

  (10) According to the third embodiment, the width of the preliminary drying laser head DL in the forward movement direction is smaller than the width of the ejection head 20 in the forward movement direction. Accordingly, the ejection heads 20 can be brought close to each other in the forward movement direction, and the preliminary drying laser heads DL can be arranged without reducing the degree of freedom of arrangement of the ejection heads 20.

  In addition, you may change the said embodiment as follows.

In the above embodiment, the pinning laser head PL and the predrying laser head DL are configured by different laser light sources. Not limited to this, one laser light source, splitting means for splitting and outputting the laser from the laser light source (for example, a beam splitter, a half mirror, etc.), and the beam shape of the laser beam L1 for pinning one of the split lasers A pinning optical system that is shaped into a shape and a preliminary drying optical system that shapes the other divided laser into the beam shape of the preliminary drying laser L2 may be used. Then, the laser from one laser light source may be divided, and the divided lasers may be irradiated as the pinning laser L1 and the preliminary drying laser L2, respectively.

  According to this, the number of laser light sources can be reduced, and the droplet discharge device 10 can be reduced in size and cost.

  Furthermore, when the laser beam from one light source is polarized and divided, a configuration in which the pinning laser L1 is p-polarized light is preferable. The pinning laser L1 is incident on the droplet Fb along the substantially tangential direction of the ejection surface 4Ga. Therefore, by making the pinning laser L1 into p-polarized light, the surface reflection of the droplet Fb can be reduced and the absorption efficiency can be improved as compared with the case of irradiation with s-polarized light. Therefore, the droplet Fb can be pinned more reliably.

  In addition, when a laser beam from one light source is polarized and divided, a configuration in which a liquid crystal electro-optical element is provided between the light source and the dividing unit is preferable. The liquid crystal electro-optic element rotates the polarization plane of the laser from the light source to define the intensity of the pinning laser L1 and the intensity of the preliminary drying laser L2. Therefore, the intensity distribution of the pinning laser L1 and the predrying laser L2 can be easily changed by driving and controlling the liquid crystal electro-optical element.

  In the above embodiment, a pinning spot is formed in the unit irradiation region S1, and the droplet diameter immediately after landing is maintained in the landed droplet Fb. For example, the pinning spot may be separated from the unit irradiation region S1 by a predetermined distance, and the landed droplets Fb may be wet and spread by a predetermined distance in the forward or backward time. In other words, any configuration may be used as long as the landed droplet Fb is irradiated with the pinning laser L1 before the landed droplet Fb spreads to a predetermined size.

  In the above embodiment, the pinning laser head PL is arranged for each ejection head pair 20P. For example, the pinning laser head PL may be arranged for each ejection head 20. Further, the pinning laser head PL may be arranged for each nozzle row NL. In other words, any configuration may be used as long as the landed droplet Fb is irradiated with the pinning laser L1 before the landed droplet Fb spreads to a predetermined size.

  In the above embodiment, the substrate is embodied in the green sheet 4G. For example, the substrate may be embodied as a polyimide substrate, a glass epoxy substrate, or the like. In this case, it is preferable that the selected wavelength of the laser is set in a region where the polyimide substrate or the glass-epoxy substrate has a high reflectance.

  In the above embodiment, the droplet discharge head is embodied as the piezoelectric element drive type droplet discharge head 20. 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 droplet discharge head.

  In the above embodiment, the pattern forming material is embodied in the metal ink F. 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 only needs to be a material that is fixed by receiving the first laser and dried by receiving the second laser.

  In the above embodiment, the pattern is embodied in the internal wiring 6 of the LTCC multilayer substrate 2. However, the present invention is not limited to this, and the pattern may be embodied in various 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. . That is, the pattern may be a solid phase pattern formed by dry droplets.

The side sectional view showing the circuit module of the present invention. Similarly, a perspective view showing a droplet discharge device. Similarly, a diagram illustrating a droplet discharge head. FIG. Similarly, a sectional side view showing a droplet discharge head. Similarly, both (a) and (b) are diagrams for explaining the position of the laser head. Similarly, both (a) and (b) are diagrams for explaining the position of the laser head. Similarly, the electric block circuit diagram explaining the electrical constitution of a droplet discharge device. (A), (b) is a figure explaining the arrangement position of the laser head of a modification. (A), (b) is a figure explaining the arrangement position of the laser head of a modification.

Explanation of symbols

F ... Metal ink as pattern forming material, Fb ... Droplet, L1 ... Laser for pinning as first laser, L2 ... Laser for preliminary drying as second laser, PL ... Laser for pinning as first laser irradiation means Head, DL: Laser head for preliminary drying as second laser irradiation means, 1 ... Circuit module, 4G ... Green sheet as substrate, 5 ... Circuit element, 6 ... Internal wiring as pattern, 10 ... Droplet ejection device, 13... Stage as relative moving means, 19... Carriage, 20... Droplet discharge head, 20 T.

Claims (14)

A droplet discharge step of discharging a droplet of the pattern forming liquid onto the substrate;
A first laser that irradiates a first laser along a substantially tangential direction of the substrate and fixes the droplet at a landing position of the droplet before the droplet that has landed on the substrate spreads to a predetermined size. Irradiation process;
Irradiating the fixed droplet with a second laser having higher energy than the first laser along a substantially normal direction of the substrate, and pre-drying the droplet;
A pattern forming method comprising: A droplet discharge step of discharging a droplet of metal ink onto the substrate;
A first laser that irradiates a first laser along a substantially tangential direction of the substrate and fixes the droplet at a landing position of the droplet before the droplet that has landed on the substrate spreads to a predetermined size. Irradiation process;
Irradiating the fixed droplet with a second laser having higher energy than the first laser along a substantially normal direction of the substrate, and pre-drying the droplet;
A method of manufacturing a circuit module, comprising: A carriage,
Relative movement means for moving the substrate in one direction relative to the carriage;
A droplet discharge head mounted on the carriage and discharging droplets of a pattern forming liquid onto the substrate;
First laser irradiation means mounted on the carriage and irradiating a region of the droplet landed on the substrate along a substantially tangential direction of the substrate to fix the droplet;
A second laser mounted on the carriage and having an energy higher than that of the first laser is applied to the fixed droplet region along a substantially normal direction of the substrate to preliminarily dry the droplet. A second laser irradiation means;
A droplet discharge apparatus comprising: In the droplet discharge device according to claim 3,
A laser light source for emitting a laser;
Splitting means for splitting the laser from the laser light source;
With
The first laser irradiation unit includes a first optical system that irradiates one of the laser beams divided by the dividing unit as the first laser to the region of the droplet,
The second laser irradiation means has a second optical system that irradiates the fixed droplet region with the other laser divided by the dividing means as the second laser,
A droplet discharge device characterized by the above. In the droplet discharge device according to claim 3 or 4,
The relative movement means is a stage that reciprocates the substrate;
The first laser irradiating means and the second laser irradiating means are respectively disposed in the forward movement direction and the backward movement direction of the droplet discharge head;
A droplet discharge device characterized by the above. In the liquid droplet ejection device according to any one of claims 3 to 5,
The carriage includes a plurality of droplet discharge heads and a plurality of second laser irradiation means corresponding to the plurality of droplet discharge heads,
The plurality of droplet discharge heads are arranged at a predetermined pitch width along the one direction,
Each of the plurality of second laser irradiation means is arranged in the one direction with the same pitch width as the pitch width of the droplet discharge head;
A droplet discharge device characterized by the above. The droplet discharge device according to claim 6,
Each of the plurality of second laser irradiation means is disposed between adjacent droplet discharge heads when viewed from the normal direction of the substrate;
A droplet discharge device characterized by the above. In the droplet discharge device according to claim 7,
The width in the one direction of the second laser irradiation means is smaller than the width in the one direction of the droplet discharge head;
A droplet discharge device characterized by the above. In the droplet discharge device according to any one of claims 3 to 8,
The carriage is equipped with a plurality of the droplet discharge heads,
The plurality of droplet discharge heads are arranged along the other direction,
The second laser irradiation means irradiates the second laser common to the droplets from the droplet discharge heads adjacent along the other direction;
A droplet discharge device characterized by the above. In the droplet discharge device according to any one of claims 3 to 9,
The droplet discharge head is disposed between the substrate and the second laser irradiation means when viewed from the tangential direction of the substrate;
A droplet discharge device characterized by the above. In the droplet discharge device according to any one of claims 3 to 10,
The droplet discharge head includes a flow path extending in a normal direction of the substrate;
A droplet discharge device characterized by the above. In the droplet discharge device according to any one of claims 3 to 11,
The droplets have a surfactant that repels other droplets in a pre-dried state;
A droplet discharge device characterized by the above. In a circuit module comprising a substrate, a circuit element formed on the substrate, and a wiring formed on the substrate and electrically connected to the circuit element,
The circuit module, wherein the wiring is formed by the droplet discharge device according to any one of claims 3 to 12. A carriage,
Relative movement means for moving the substrate in one direction relative to the carriage;
A droplet discharge head mounted on the carriage and discharging a droplet of metal ink onto the substrate;
First laser irradiation means mounted on the carriage and irradiating a region of the droplet landed on the substrate along a substantially tangential direction of the substrate to fix the droplet;
A second laser mounted on the carriage and having an energy higher than that of the first laser is applied to the fixed droplet region along a substantially normal direction of the substrate to preliminarily dry the droplet. A second laser irradiation means;
A circuit module manufacturing apparatus comprising:

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