JP2008155083A - Pattern forming device and circuit board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pattern forming device simple in constitution, making a liquid droplet discharge head to be hardly affected by the ambient temperature and capable of enhancing the stability of the discharge amount of liquid droplets to form a pattern of high precision, and a circuit board. <P>SOLUTION: The liquid droplet discharged head 30 has a heat sink 40 attached to its side surface. The heat sink 40 is formed of an aluminum plate and the joint 40a thereof is connected to the support plate 29 of a carriage by a set screw 42 so that the joint 40b thereof is brought into contact with the side surface of the discharge head 30. Further, the heat sink 40 is covered with a heat insulating member 43 to cut off the radiant heat from a green sheet 4G by the heat insulating member 43. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a pattern forming apparatus and a circuit board.

In recent years, an inkjet method in which a functional liquid is ejected as droplets by a droplet ejection head to form a desired pattern on a substrate has attracted attention as an effective means (for example, Patent Document 1).
In general, the inkjet method is a two-dimensional relative movement between a substrate placed on a stage, a droplet ejection head that ejects functional liquid containing a functional material as droplets onto the substrate, and the substrate and the droplet ejection head. It has a mechanism to make it. Then, the droplets discharged from the droplet discharge head are arranged at an arbitrary position on the substrate surface. At this time, for each droplet that is sequentially arranged on the substrate surface, the droplets are sequentially arranged so that the wetted and spread areas of the droplets overlap each other, thereby forming a pattern covered with the functional liquid without any gaps on the substrate surface. can do.

By the way, when the substrate surface has liquid repellency with respect to the functional liquid, the force with which the droplets in contact with each other attract each other due to the surface tension is stronger than the force with which the substrate surface and the functional liquid attract, Phenomenon that functional fluid concentrates locally. When such local concentration occurs, the substrate surface is not uniformly covered with the functional liquid, and in the worst case, a part of the substrate surface is exposed due to the lack of the functional liquid.

For this reason, when the droplets in contact with each other are stacked, it is necessary to land the next droplet after the previously landed droplet is sufficiently dried, and it takes time to form a pattern. Therefore, a method has been proposed in which the substrate is heated in advance and the landed droplets are dried quickly (for example, Patent Document 2 and Patent Document 3).
JP 2004-347695 A JP 2004-306372 A JP-A-11-281985

However, the distance between the nozzle forming surface of the droplet discharge head and the substrate is very narrow. As a result, when forming a pattern on the substrate by discharging droplets with the substrate heated as described above,
The droplet discharge head is heated by heat from the heated substrate. As a result, the functional liquid discharged from the droplet discharge head is heated and the viscosity is lowered. In addition, there are various problems such as fluctuations in nozzle pitch due to thermal expansion of the nozzle plate and drying of the solution adhering to the inside of the droplet discharge head.

The present invention has been made in order to solve the above-described problems, and an object of the present invention is to make the droplet discharge head less susceptible to the ambient temperature with a simple configuration, and to reduce the droplet discharge amount. An object of the present invention is to provide a pattern forming apparatus and a circuit board capable of improving the stability and forming a highly accurate pattern.

The pattern forming apparatus of the present invention forms a pattern on the substrate by moving the droplet discharge head relative to the substrate and discharging droplets of the functional liquid toward the substrate with the droplet discharge head. In the pattern forming apparatus, a heat radiating means is brought into contact with the droplet discharge head.

According to the pattern forming apparatus of the present invention, even if the droplet discharge head is warmed by the ambient temperature, the function liquid is suppressed from being affected by the ambient temperature because the heat is released by contacting the heat radiating means. And kept at a constant temperature. As a result, it is possible to always discharge a certain amount of droplets.

In addition, the droplet discharge head can be made independent of the ambient temperature with a simple configuration in which the heat radiating means is brought into contact with the droplet discharge head.
In this pattern forming apparatus, the droplet discharge head is connected and fixed to a support plate of a carriage that reciprocates, and the heat radiating means is connected and fixed to the support plate in surface contact. Forming equipment.

According to this pattern forming apparatus, since the heat dissipation means is brought into surface contact with the support plate, the heat dissipation means is
With a simple configuration, the heat of the droplet discharge head can be efficiently radiated to the support plate.
In this pattern forming apparatus, the heat radiating means is connected and fixed to the support plate so that the position thereof can be adjusted.

According to this pattern forming apparatus, the heat radiating means can be brought into surface contact with the support plate easily and reliably.
In this pattern forming apparatus, the heat dissipation means is a metal.

According to this pattern forming apparatus, since the heat radiating means is formed of a metal having good thermal conductivity, the heat of the droplet discharge head can be efficiently radiated.
In this pattern forming apparatus, the metal is aluminum.

According to this pattern forming apparatus, since the heat radiating means is formed of aluminum having good thermal conductivity, the heat of the droplet discharge head can be efficiently radiated.
In this pattern forming apparatus, the metal is copper.

According to this pattern forming apparatus, since the heat radiating means is formed of copper having good thermal conductivity, the heat of the droplet discharge head can be efficiently radiated.
In this pattern forming apparatus, the heat dissipating means is covered with a heat insulating member.

According to this pattern forming apparatus, since the heat radiating means is shielded from the ambient temperature for the heat insulating member, the heat of the droplet discharge head can be efficiently radiated.
In this pattern forming apparatus, the support plate is provided with a cooling means.

According to this pattern forming apparatus, since the cooling means is provided on the support plate, the heat radiating means can efficiently radiate the heat of the droplet discharge head to the support plate.
In this pattern forming apparatus, the cooling means includes a refrigerant and a circulation channel for circulating the refrigerant formed on the support plate.

According to this pattern forming apparatus, the heat radiating means can radiate the heat of the droplet discharge head to the support plate more efficiently with a simple configuration in which the refrigerant is circulated through the circulation flow path formed on the support plate.

In this pattern forming apparatus, the substrate is a low-temperature firing sheet composed of a porous substrate and ceramic particles and a resin, and the functional liquid is a liquid in which metal particles are dispersed as a functional material. .

According to this pattern forming apparatus, a pattern made of a metal film can be neatly formed in a short time on a porous substrate.
The circuit board of the present invention is a circuit board on which a circuit element is mounted and a wiring electrically connected to the mounted circuit element is formed, and the circuit board according to any one of claims 1 to 11 Wiring formed by a pattern forming apparatus was provided.

  According to the circuit board of the present invention, productivity can be further increased.

Hereinafter, the present invention is referred to as an LTCC multilayer substrate (LTCC: Low Temperature Co-fired Ceramics).
1 is a circuit module formed by mounting a semiconductor chip on a multilayer substrate), and is embodied in the formation of a wiring pattern drawn on a plurality of low-temperature fired substrates (green sheets) constituting the LTCC multilayer substrate. Description will be given with reference to FIG.

First, a circuit module formed by mounting a semiconductor chip on an LTCC multilayer substrate will be described. FIG. 1 shows a cross-sectional view of a circuit module 1. The circuit module 1 has an LTCC multilayer substrate 2 formed in a plate shape, and a semiconductor chip 3 connected by wire bonding to the upper side of the LTCC multilayer substrate 2. is doing.

The LTCC multilayer substrate 2 is a laminate of a plurality of low-temperature fired substrates 4 formed in a sheet shape.
Each low-temperature fired substrate 4 is a sintered body (porous substrate) 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 the thickness thereof is It is formed with several hundred μm.

The low-temperature fired substrate 4 is called a green sheet 4G (see FIG. 2) before being sintered. The green sheet 4G is prepared by mixing a glass ceramic material powder and a dispersion medium together with a binder, a foam stabilizer, and the like to form a slurry, which is formed into a plate shape, and then dried.

Each low-temperature fired substrate 4 includes various circuit elements 5 such as a resistance element, a capacitance element, and a coil element,
Internal wiring 6 that electrically connects each circuit element 5, a plurality of via holes 7 having a predetermined via diameter (for example, 20 μm) that exhibits a stacked via structure and a thermal via structure, and the via holes 7
The via wiring 8 filled in is appropriately formed based on the circuit design.

Each internal wiring 6 on each low-temperature fired substrate 4 is a sintered body of metal fine particles such as silver or a silver alloy, and wiring is performed using a droplet discharge device 20 as a pattern forming apparatus shown in FIG. A pattern is formed.

FIG. 2 is an overall perspective view illustrating the droplet discharge device 20.
In FIG. 2, the droplet discharge device 20 has a base 21 formed in a rectangular parallelepiped shape.
A pair of guide grooves 22 extending along the longitudinal direction (Y direction) is formed on the upper surface of the base 21. Above the guide groove 22, a stage 23 is provided that moves in the Y direction and the anti-Y direction along the guide groove 22.

A placement portion 24 is formed on the upper surface of the stage 23, and a green sheet 4G as a base before firing is placed thereon. The placement unit 24 moves the green sheet 4G placed on the stage 2
3, the green sheet 4G is conveyed in the Y direction and the anti-Y direction. A rubber heater H is disposed on the upper surface of the stage 23. The entire upper surface of the green sheet 4G placed on the placement unit 24 is heated to a predetermined temperature by the rubber heater H.

A gate-shaped guide member 25 is laid on the base 21 so as to straddle a direction (X direction) orthogonal to the Y direction. On the upper side of the guide member 25, a cooling tank T1 and an ink tank T2 are disposed. The cooling tank T1 includes a cooling mechanism (not shown), cools the water W as a refrigerant by the cooling mechanism, and stores it as cooling water. The cooling tank T <b> 1 includes a circulation mechanism (not shown), supplies the cooling water W to the support plate 29 of the carriage 28, and collects the cooling water W heat-exchanged in the support plate 29 again.

The ink tank T2 stores the metal ink F as a functional liquid, and supplies the stored metal ink F to a droplet discharge head (hereinafter simply referred to as a discharge head) 30 at a predetermined pressure. The metal ink F supplied to the ejection head 30 is ejected from the ejection head 30 as droplets Fb (see FIG. 4) toward the green sheet 4G.

As the metal ink F, a dispersed metal ink in which metal fine particles as a functional material, for example, metal fine particles as a functional material having a particle size of several nm are dispersed in a solvent can be used.
Examples of the metal fine particles used in the metal ink F include gold (Au), silver (Ag), and copper (
Cu), aluminum (Al), palladium (Pd), manganese (Mn), titanium (Ti
), Tantalum (Ta), nickel (Ni), and the like, oxides thereof, and superconductor fine particles. The particle diameter of the metal fine particles is preferably 1 nm or more and 0.1 μm or less. If it is larger than 0.1 μm, the discharge nozzle N of the discharge head 30 may be clogged. On the other hand, if it is smaller than 1 nm, the volume ratio of the dispersant to the metal fine particles increases, and the ratio of the organic matter in the resulting film becomes excessive.

The dispersion medium is not particularly limited as long as it can disperse the metal fine particles and does not cause aggregation. For example, in addition to aqueous solvents, alcohols such as methanol, ethanol, propanol, butanol, n-heptane, n-octane, decane, dodecane, tetradecane, toluene, xylene, cymene, durene, indene, dipentene, tetrahydronaphthalene, decahydronaphthalene , Hydrocarbon compounds such as cyclohexylbenzene,
Also, polyols such as ethylene glycol, diethylene glycol, triethylene glycol, glycerin, 1,3-propanediol, polyethylene glycol, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol methyl ethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol methyl Ether compounds such as ethyl ether, 1,2-dimethoxyethane, bis (2-methoxyethyl) ether, p-dioxane,
Further examples include polar compounds such as propylene carbonate, γ-butyrolactone, N-methyl-2-pyrrolidone, dimethylformamide, dimethyl sulfoxide, cyclohexanone, and ethyl lactate. Of these, water, alcohols, hydrocarbon compounds, and ether compounds are preferable and more preferable dispersion media in terms of fine particle dispersibility, dispersion stability, and ease of application to the droplet discharge method. Examples thereof include water and hydrocarbon compounds.

In the metal ink F that has landed on the green sheet 4G, the evaporation of the solvent or the dispersion medium is promoted because the green sheet 4G is heated. The metal ink F that has landed on the green sheet 4G thickens from the outer edge of the surface as it dries. That is, the solid content (particles) concentration in the outer peripheral portion is faster than the central portion and reaches the saturated concentration. Thicken from the outer edge. 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 is fixed to the green sheet 4G even if it is fixed to the green sheet 4G and overprinted.
Since the outer diameter of the droplet Fb does not change, it is not attracted to the next droplet Fb.

The guide member 25 is formed with a pair of upper and lower guide rails 27 extending in the X direction over substantially the entire length in the X arrow direction. A carriage 28 is attached to the pair of upper and lower guide rails 27. The carriage 28 is guided by the guide rail 27 and is in the X direction and anti-X direction.
Move in the direction. A droplet discharge head 30 is mounted on the carriage 28.

3 shows a bottom view of the ejection head 30 as viewed from the green sheet 4G side, and FIG. 5 and 6 are a perspective view and an exploded perspective view of a main part for explaining the mounting state of the ejection head 30 and the carriage 28. FIG.

As shown in FIG. 6, the ejection head 30 has a rectangular parallelepiped shape that is long in the X direction, and its upper surface 3.
A port P0 for introducing the metal ink F of the ink tank T2 is provided at 0a. Also,
A flange 30 b is formed on the upper side surface of the discharge head 30. The ejection head 30 is inserted from above into a rectangular through hole 29a formed in the support plate 29 of the carriage 28 and elongated in the X direction. At this time, the flange 30b formed on the ejection head 30 serves not only to prevent detachment, but also serves as a connecting portion (not shown) that is connected and fixed to the support plate 29 with screws or the like. That is, the ejection head 30 is inserted into the carriage 28 by inserting the through hole 29a formed in the support plate 29 from above (anti-Z direction) and fixing the flange 30b to the support plate 29 with a screw (not shown). To be attached. The support plate 29 is made of stainless steel in this embodiment.

A nozzle plate 31 is provided below the discharge head 30 protruding from the support plate 29 of the carriage 28. The lower surface (nozzle formation surface 31a) of the nozzle plate 31 is formed substantially parallel to the upper surface 4Ga of the green sheet 4G. When the green sheet 4G is positioned directly below the ejection head 30, the nozzle plate 31 sets a distance (platen gap) between the nozzle forming surface 31a and the upper surface 4Ga of the green sheet 4G to a predetermined distance (for example, 500).
μm).

In FIG. 3, a pair of nozzle rows NL composed of a plurality of nozzles N arranged along the X direction is formed on the nozzle forming surface 31a. In the pair of nozzle rows NL, 180 nozzles N are formed per inch. In FIG. 3, for convenience of explanation, only 10 nozzles N are shown per row.

In the pair of nozzle rows NL, the nozzles N of one nozzle row NL interpolate between the nozzles N of the other nozzle row NL when viewed from the X direction. That is, the ejection head 30 is
180 × 2 = 360 nozzles N per inch (maximum resolution is 360 dpi)
Is).

In FIG. 4, a supply tube 30 </ b> T that forms a flow path is connected to the port P <b> 0 of the discharge head 30.
Are connected. The supply tube 30T is disposed so as to extend in the Z direction, and supplies the metal ink F from the ink tank T2 to the ejection head 30.

On the upper side of each nozzle N, a cavity 32 communicating with the supply tube 30T is formed. The cavity 32 accommodates the metal ink F from the supply tube 30T and supplies the metal ink F to the corresponding nozzle N. On the upper side of the cavity 32, a vibration plate 33 is attached, which vibrates in the vertical direction and expands and contracts the volume in the cavity 32. A piezoelectric element PZ corresponding to the nozzle N is disposed on the upper side of the vibration plate 33. The piezoelectric element PZ contracts and expands in the vertical direction to vibrate the diaphragm 33 in the vertical direction. Diaphragm 3 that vibrates vertically
3 ejects the metal ink F from the corresponding nozzles N into droplets Fb of a predetermined size. The discharged droplets Fb fly in the anti-Z direction of the corresponding nozzle N and land on the upper surface 4Ga of the green sheet 4G.

On the side surfaces of the ejection head 30 protruding from the support plate 29 in the Y direction and the anti-Y direction, heat radiating plates 40 as heat radiating means are arranged so as to be in surface contact with each other. In this embodiment, the heat radiating plate 40 is made of an aluminum plate that is a metal having high thermal conductivity, and is formed in an L-shaped cross section. The heat radiating plate 40 includes a connecting portion 40 a that connects to the support plate 29 and a contact portion 40 b that contacts the ejection head 30. The connecting portion 40a has a long hole 4 that is long in the Y direction at a predetermined interval.
1 is formed. The heat radiating plate 40 is connected and fixed to the support plate 29 by inserting a set screw 42 into the long hole 41 and screwing it into the support plate 29. More specifically, with the set screw 42 loosened, the position of the heat radiating plate 40 is adjusted to bring the contact portion 40b of the heat radiating plate 40 into surface contact with the side surface of the ejection head 30. With the contact portion 40b in surface contact with the side surface of the ejection head 30, the set screw 4
2, the heat sink 40 is connected to the support plate 29. Accordingly, the heat of the discharge head 30 is radiated from the heat sink 40.
The ejection head 30 that is conducted to the support plate 29 via is less affected by the surrounding atmosphere (temperature) and is maintained at a constant temperature. For example, when the ejection head 30 is replaced, the set screw 42 is loosened so that the ejection head 30 can be easily pulled upward from the support plate 29.

A heat insulating member 43 is disposed on the outer surface of the heat radiating plate 40. The heat insulating member 43 is the heat sink 4
Like 0, it has an L-shaped cross section and is fixed to the support plate 29 together with the heat sink 40 by the set screw 42. The heat insulating member 43 is fixed to the support plate 2 by a set screw 42 together with the heat sink 40.
When fixed to 9, the outer surface of the heat radiating plate 40 (excluding the side surfaces in the X direction and the anti-X direction) is covered with a heat insulating member 43. As a result, the heat sink 40 is shielded from the atmosphere (temperature) around the ejection head 30 by the heat insulating member 43.

As shown in FIG. 6, a groove 4 is formed on the upper surface of the support plate 29 so as to surround the through hole 29a.
4 is recessed. Both ends of the groove 44 are opposed to each other across the wall. On the upper surface of the support plate 29, a closing plate 45 is tightly connected and closes the opening of the groove 44 to form a circulation channel 46. An inlet port P1 and a lead-out port P2 are formed in the closing plate 45 where both ends of the groove 44 are located. The introduction port P1 is connected to the cooling tank T1 via a tube (not shown), and supplies the cooling water W cooled in the cooling tank T1 to the circulation flow path 46. Derivation port P2 is
The cooling water W connected to the cooling tank T1 through a tube (not shown) and circulated through the circulation flow path 46 is sent back to the cooling tank T1.

Therefore, the support plate 29 is cooled by the cooling water W flowing through the circulation flow path 46. As a result, when the ejection head 30 is heated, the heat is efficiently radiated to the support plate 29 via the heat radiating plate 40.

Next, the electrical configuration of the droplet discharge device 20 configured as described above will be described with reference to FIG.
In FIG. 7, the control device 50 includes a CPU 50A, a ROM 50B, a RAM 50C, and the like. The control device 50 executes a transfer process of the stage 23, a transfer process of the carriage 28, a droplet discharge process of the discharge head 30, a heating process of the rubber heater H, and the like according to the stored various data and various control programs.

An input / output device 51 having various operation switches and a display is connected to the control device 50. The input / output device 51 displays the processing status of various processes executed by the droplet discharge device 20. The input / output device 51 generates bitmap data BD for forming the internal wiring 6,
The bitmap data BD is input to the control device 50.

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 stored in the ejection head 30.
This is data defining whether or not the wiring droplets Fb are ejected to each position on the drawing plane (upper surface 4Ga of the green sheet 4G) passing directly under (each nozzle N). That is, the bitmap data BD is stored in the wiring droplet F at the target formation position of the internal wiring 6 defined on the upper surface 4Ga.
This is data for discharging b.

An X-axis motor drive circuit 52 is connected to the control device 50. The control device 50 outputs a drive control signal to the X-axis motor drive circuit 52. In response to the drive control signal, the X-axis motor drive circuit 52 rotates the X-axis motor MX for moving the carriage 28 forward or backward. A Y-axis motor drive circuit 53 is connected to the control device 50. The control device 50
A drive control signal is output to the Y-axis motor drive circuit 53. In response to the drive control signal, the Y-axis motor drive circuit 53 rotates the Y-axis motor MY for moving the stage 23 forward or backward.

A head drive circuit 54 is connected to the control device 50. The control device 50 outputs a discharge timing signal LT synchronized with a predetermined discharge frequency to the head drive circuit 54. The control device 50 outputs a drive voltage COM for driving each piezoelectric element PZ to the head drive circuit 54 in synchronization with the ejection frequency.

The control device 50 uses the bitmap data BD to generate a pattern formation control signal SI synchronized with a predetermined frequency, and serially transfers the pattern formation control signal SI to the head drive circuit 54. The head drive circuit 54 sends the pattern formation control signal SI to each piezoelectric element P.
Serial / parallel conversion is performed sequentially corresponding to Z. The head drive circuit 54 is connected to the control device 50.
Each time the ejection timing signal LT is received, the pattern formation control signal SI subjected to serial / parallel conversion is latched, and the drive voltage COM is supplied to each of the piezoelectric elements PZ selected by the pattern formation control signal SI.

A rubber heater drive circuit 55 is connected to the control device 50. The control device 50 outputs a drive control signal to the rubber heater drive circuit 55. In response to the drive control signal, the rubber heater drive circuit 55 drives the rubber heater H and controls the heating of the green sheet 4G placed on the stage 23 so as to reach a predetermined temperature. In the present embodiment, the predetermined temperature of the green sheet 4G (the temperature of the upper surface 4Ga) is equal to or higher than the temperature of the metal ink F when ejected from the ejection head 30 and less than the boiling point of the liquid composition contained in the metal ink F (liquid The temperature is controlled to be a temperature of less than the lowest boiling point in the composition. That is, green sheet 4G
Is heated above the temperature of the metal ink F when discharged from the discharge head 30 and is not dried by the discharge head 30 when discharged, and the landed droplet Fb is heated and dried quickly at a temperature higher than that. In addition, the green sheet 4G is heated below the boiling point of the droplet Fb to land the droplet Fb
To prevent bumping on the green sheet 4G.

Next, a method for forming a wiring pattern of the green sheet 4G using the droplet discharge device 20 will be described.
As shown in FIG. 2, the green sheet 4G is placed on the stage 23. At this time, the stage 23 arranges the green sheet 4G in the anti-Y direction of the carriage 28. In this green sheet 4G, a via hole 7 is formed, and a via wiring 8 is formed in the via hole 7,
The internal wiring 6 is formed on the upper surface 4Ga.

From this state, bitmap data BD for forming a wiring pattern of the internal wiring 6 by the droplet Fb is input from the input / output device 51 to the control device 50. The control device 50 stores bitmap data BD for forming the internal wiring 6 from the input / output device 51. At this time, the control device 50 drives the rubber heater H provided on the stage 23 via the rubber heater drive circuit 55 so that the entire green sheet 4G placed on the stage 23 is uniformly at the predetermined temperature. Heating is controlled. That is, the upper surface 4Ga of the green sheet 4G is equal to or higher than the temperature of the metal ink F when discharged from the discharge head 30 and less than the boiling point of the liquid composition contained in the metal ink F (less than the lowest boiling point in the liquid composition). The temperature is controlled.

Next, the control device 50 drives the X-axis motor MX via the X-axis motor drive circuit 52 so that the predetermined position of the green sheet 4G passes in the Y direction directly under the discharge head 30.
The carriage 28 is moved (feeded) to a predetermined position. Next, the control device 50 drives the Y-axis motor MY via the Y-axis motor drive circuit 53 to move (scan) the stage 23 (green sheet 4G) in the Y direction.

When the green sheet 4G starts to move forward (scan), the control device 50 generates a pattern formation control signal SI based on the bitmap data BD, and outputs the pattern formation control signal SI and the drive voltage COM to the head drive circuit. To 54. That is, the control device 50 drives and controls each piezoelectric element PZ via the head drive circuit 54, and each time the discharge head 30 faces the landing position for forming the internal wiring 6, the liquid is discharged from the selected nozzle N. The droplet Fb is discharged. The droplet Fb landed on the green sheet 4G is the droplet Fb when the green sheet 4G is discharged.
Since it is heated to a temperature equal to or higher than this temperature, drying is started and quickly dried.

In the present embodiment, as shown in FIGS. 8A to 8D, each droplet Fb to be ejected sequentially reaches a landing position for forming the corresponding internal wiring 6. More specifically, in this embodiment,
The liquid droplets Fb landed and arranged first for pattern formation partially dry and become green sheets 4G.
The liquid droplet Fb that is fixed (pinned) with respect to the liquid droplet (the state in which its own wetting and spreading has been stopped) is ejected from the next ejection head 30 and landed on the green sheet 4G. Are ejected from the ejection head 30 at a position indicated by a one-dot chain line in FIG.

That is, the ejection timing of the droplet Fb ejected from the ejection head 30 is the time required for the droplet Fb to be ejected from the ejection head 30 and fixed (pinned) to the green sheet 4G.
After the ejection head 30 ejects the previous droplet Fb, it is determined by the moving time required until the green sheet 4G reaches the ejection position where a part of the next droplet Fb overlaps the previous droplet Fb. Accordingly, the discharge timing (discharge interval time) is set in advance through experiments or the like based on the heating temperature of the green sheet 4G, the moving speed of the stage 23, and the like.

Accordingly, the ejection head 30 moves to the droplet F with respect to the green sheet 4G moving forward in the Y direction.
When b is discharged at a predetermined timing (discharge interval time), the green sheet 4G first
The droplets Fb that have landed are quickly dried.

Then, as shown in FIG. 8B, when the droplet Fb is fixed to the green sheet 4G, the droplet Fb that has entered the fixed state is partially overlapped. The next droplet Fb is landed and arranged at the position indicated by the alternate long and short dash line in FIG. At this time, the previous droplet Fb in the fixed state is not attracted to the next droplet Fb that is landed and arranged so that a part of the droplets overlaps. Further, the next droplet Fb that has been landed and arranged so that a part thereof overlaps, the green sheet 4G is heated in the non-overlapping part, so that the drying immediately starts and is quickly dried and fixed. Therefore, the next droplet Fb is not attracted to the previous droplet Fb.

As a result, the droplets Fb that sequentially land at the landing positions for forming the internal wiring 6 by moving the green sheet 4G in the Y direction are dried without being deviated from the landing positions.
As shown in FIG. 8D, a wiring pattern P for the internal wiring 6 is formed. Moreover,
Since the green sheet 4G is heated and the green sheet 4G of the air permeable substrate is used, the landed droplet Fb quickly dries and enters a fixed state. Therefore, the discharge timing of the next landed droplet Fb can be shortened. In addition, the wiring pattern P for the internal wiring 6 can be formed in a short time. Furthermore, since the heating temperature of the green sheet 4G is controlled to a temperature lower than the boiling point of the droplet Fb, the landed droplet Fb does not bump and the formation of the wiring pattern P is not disabled.

While the green sheet 4G is moving in the Y direction, the nozzle plate 3 of the ejection head 30 is always used.
1 is heated by the heat of the heated green sheet 4G. At this time, the heat radiating plate 40 that is in surface contact with the side surface of the ejection head 30 radiates heat to be accumulated in the ejection head 30 to the support plate 29. Accordingly, the temperature rise of the ejection head 30, that is, the temperature rise of the metal ink F (
(Viscosity reduction) is suppressed, and thermal expansion of the nozzle plate 31 is suppressed. As a result, fluctuations in the discharge amount due to a decrease in the viscosity of the metal ink F and fluctuations in the nozzle pitch due to thermal expansion of the nozzle plate 31 are suppressed, and clogging due to drying of the ink F in the vicinity of the nozzles N is suppressed. .

When the ejection head 30 completes scanning from end to end of the green sheet 4G, the control device 50 causes the droplet Fb to be ejected to a new position on the green sheet 4G for forming the internal wiring 6. The carriage 2 is driven by driving the X-axis motor MX via the shaft motor drive circuit 52.
8 (ejection head 30) is moved (feeded) in the X direction by a predetermined amount. Thereafter, the control device 50 causes the stage 23 (green sheet 4G) to move back (scan) in the anti-Y direction.

When the green sheet 4G starts moving backward (scanning), the control device 50 controls the driving of each piezoelectric element PZ via the head driving circuit 54 based on the bitmap data BD as described above, and forms the internal wiring 6. Each time the ejection head 30 faces the landing position for the purpose, the droplet Fb is ejected from the selected nozzle N. Also in this case, as described above, the droplets Fb that have landed on the green sheet 4G first start drying immediately and are quickly dried. Then, when the droplet Fb is fixed to the green sheet 4G, the next droplet Fb is landed and arranged so that a part of the droplet Fb enters the fixed state.

Thereafter, the stage 23 is reciprocated (scanned) in the Y direction and the anti-Y direction, and the ejection head 30 is fed in the X direction. During the reciprocating movement of the stage 23, the droplet Fb is moved at a timing based on the bitmap data BD. Repeat the discharge operation. As a result, the wiring pattern P of the internal wiring 6 is drawn on the green sheet 4G by the landed droplets Fb.

When the wiring pattern P of the internal wiring 6 is drawn on one green sheet 4G, the control device 50 controls the carriage 28 (X-axis motor MZ) to guide the ejection head 30 to standby and temporarily stop it. And it prepares for drawing of the wiring pattern P of the next new green sheet 4G.

That is, the ejection head 30 is constantly drawing the wiring pattern P on the green sheet 4G,
Although it is about to be heated and stored by heat radiation from the heated green sheet 4G, it is radiated by the heat radiating plate 40, and the temperature rise of the discharge head 30 is suppressed. Moreover, since the support plate 29 to which the heat radiating plate 40 is connected is cooled by the cooling water W, the heat radiating plate 40 radiates the heat of the ejection head 30 to the support plate 29 more efficiently. Furthermore, the heat sink 40
Since the heat radiating plate 40 is covered with the heat insulating member 43, the heat radiating from the green sheet 4G is blocked, and the heat accumulated in the discharge head 30 is radiated more efficiently.

Incidentally, FIG. 9 shows the transition of the temperature of the discharge head 30 (surface temperature of the nozzle plate 31) during the drawing of the wiring pattern P on one green sheet 4G. In the figure, the two-dot chain line indicates the transition of the temperature of the ejection head not provided with the heat radiating plate 40, and the solid line indicates the heat radiating plate 40.
The transition of the temperature of the ejection head 30 provided with the above is shown.

It can be seen that the ejection head 30 not provided with the heat radiating plate 40 gradually rises in temperature due to the heated green sheet 4G when drawing is repeated by reciprocating in the Y direction and the anti-Y direction. On the other hand, when the ejection head 30 provided with the heat radiating plate 40 is drawn by repeatedly reciprocating in the Y direction and the anti-Y direction, the heated green sheet 4G.
The temperature rise will continue at a very small value.

Next, effects of the embodiment configured as described above will be described below.
(1) According to the above embodiment, the heat radiation plate 4 is provided on the side surface of the ejection head 30 in the droplet ejection device 20.
0 was attached to dissipate the heat of the discharge head 30, and the temperature rise of the discharge head 30 due to heat dissipation from the green sheet 4G was suppressed. Accordingly, it is possible to prevent changes in the viscosity of the droplets Fb due to the temperature rise of the discharge head 30, clogging due to drying, and expansion of the nozzle plate 31 in advance. As a result, the discharge weight of the droplets Fb can be stabilized, and a highly accurate pattern P can be formed in a short time.

(2) According to the said embodiment, the heat sink 40 is formed with a cross-sectional L-shaped aluminum plate,
The connecting portion 40a is moved to the carriage 28 so that the contact portion 40b contacts the side surface of the ejection head 30.
The support plate 29 is connected by a set screw 42. Therefore, the heat radiating plate 40 can suppress the temperature rise in the discharge head 30 with a very simple configuration and simple assembly. In addition, the heat radiating plate 40 can be easily added to an existing droplet discharge device.

(3) According to the said embodiment, the heat sink 40 was coat | covered with the heat insulation member 43, and it blocked | interrupted that the heat sink 40 was heated by the heat radiation from the green sheet 4G. Therefore, the heat accumulated in the ejection head 30 is radiated more efficiently.

(4) According to the above embodiment, the circulation plate 46 is provided in the support plate 29 of the carriage 28, and the support plate 29 is cooled by circulating the cooling water W from the cooling tank T <b> 1 through the circulation channel 46. Accordingly, the heat radiating plate 40 that is connected and fixed in direct surface contact with the support plate 29 can efficiently radiate the heat accumulated in the ejection head 30 to the support plate 29.

(5) According to the above embodiment, the heat radiating plate 40 can be connected and fixed to the support plate 29 so that the position can be adjusted through the set screw 42 in the long hole 41 formed in the connecting portion 40a. Therefore, the heat radiating plate 40 can be fixed to the support plate 29 in a state in which the heat radiating plate 40 is reliably in surface contact with the side surface of the ejection head 30. For example, when the discharge head 30 is replaced, the discharge head 30 can be pulled upward from the support plate 29 by loosening the set screw 42 and slightly shifting the heat radiating plate 40. Can be easily.

(6) According to the above embodiment, since the green sheet 4G is heated to a temperature equal to or higher than the temperature of the metal ink F when ejected from the ejection head 30, the landed droplets Fb are quickly heated and dried. Next, the ejection timing of the droplets Fb to be landed can be shortened, and the wiring pattern P can be formed in a short time.

(7) According to the above embodiment, since the heating temperature of the green sheet 4G is controlled to a temperature lower than the boiling point of the droplet Fb, the landed droplet Fb does not bump. Therefore, a high-density and high-definition wiring pattern P can be formed.

(8) According to the above embodiment, when the previously landed droplet Fb enters the fixed state, the next droplet Fb is landed and arranged so as to overlap a part thereof. Accordingly, the previous droplet Fb in the fixed state is not attracted to the next droplet Fb that is landed and arranged so that a part thereof overlaps, and a high-density and high-definition wiring pattern P is formed.

(9) According to the above embodiment, the entire upper surface of the green sheet 4G is heated uniformly with the rubber heater H so as to have a predetermined temperature. Accordingly, the droplets Fb landed on the green sheet 4G evaporate from the outer peripheral portion, and the solid content (particles) concentration in the outer peripheral portion reaches a saturated concentration faster than the central portion, so Stops spreading its own wet along.
That is, since the droplets Fb that have been landed are fixed from the outer peripheral portion, the outer shape at the time of landing is not deformed. As a result, a high-density and high-definition pattern can be formed.

(10) According to the above-described embodiment, the time for which the landed droplet Fb is fixed is obtained in advance, and the droplet Fb is ejected using the time as the ejection interval time. Then, the next droplet can be discharged.

In addition, you may change the said embodiment as follows.
In the above embodiment, the liquid droplet ejection apparatus 20 (pattern forming apparatus) including the heating unit (rubber heater H) for heating the substrate (green sheet 4G) is embodied, but the heating unit for heating the substrate is not provided. The present invention may be applied to a pattern forming apparatus. In this case, the circulation channel 46 provided in the support plate 29 may be omitted, or the heat insulating member 43 may be omitted.

In the above embodiment, the stage 23 is provided with heating means (rubber heater H), the substrate (green sheet 4G) is heated, and the droplets Fb of the metal ink F are discharged onto the green sheet 4G.
Although it was a pattern forming device for drawing a wiring pattern, it is not limited to this,
The functional liquid may be any functional liquid that is ejected to form the pattern P. For example, the present invention may be applied to a pattern forming apparatus that forms an alignment film of a liquid crystal display device on a substrate by discharging a functional liquid containing an alignment film material into droplets using a droplet discharge device. Furthermore, it is applied to a pattern forming device that applies liquid crystal to a range surrounded by a sealing material formed on an element substrate of a liquid crystal display device by discharging a liquid crystal material as a functional liquid as droplets with a droplet discharge device. May be. Furthermore, the present invention may be applied to a pattern forming apparatus that forms a color filter used in a liquid crystal display device by discharging a functional liquid containing a color filter material as droplets with a droplet discharge device. You may apply to the pattern formation apparatus which discharges the functional liquid containing an insulating material as a droplet with a droplet discharge apparatus, and forms an insulating layer on a board | substrate.

In the above embodiment, the droplets Fb are arranged on the green sheet 4G and the pattern P is formed. Instead of the green sheet 4G, a polyimide substrate, a glass substrate, an epoxy substrate, a glass epoxy substrate, a ceramic substrate, or It may be changed to a silicon substrate or the like.

In the above embodiment, the support plate 29 is provided with the circulation flow path 46, and the cooling water W is circulated through the circulation flow path 46 to cool the support plate 29. However, for example, when the temperature around the ejection head 30 is not so high and only the heat radiating plate 40 can suppress the temperature of the ejection head 30 to a temperature that does not interfere with ejection, the support plate 29 is cooled. You may implement without providing in a means.

In the above embodiment, the heat radiating plate 40 is covered with the heat insulating member 43. However, for example, when the temperature around the discharge head 30 is not so high and only the heat radiating plate 40 can suppress the temperature of the discharge head 30 to a temperature that does not hinder the discharge, the heat insulating member 43 is omitted. May be.

In the above embodiment, with respect to the side surface of the discharge head 30 protruding downward from the support plate 29,
The heat sink 40 was covered so as to be in surface contact. As shown in FIGS. 10 and 11, the discharge head 3 is positioned up to the flange 30 b of the discharge head 30, that is, above the support plate 29.
The heat radiating plate 40 may be brought into surface contact up to the 0 side surface.

In this case, the heat radiating plate 40 together with the ejection head 30 is also inserted from above into a rectangular through hole 29 a formed in the support plate 29 of the carriage 28 and extending in the X direction, and is connected and fixed to the support plate 29. In FIG. 11, for convenience of explanation, the closing plate 45 that closes the opening of the groove 44 is omitted.

In the above embodiment, one ejection head 30 with respect to the carriage 28 (support plate 29).
However, the present invention may be applied to the droplet discharge device 20 in which the carriage 28 includes a plurality of discharge heads 30. For example, as shown in FIG.
A plurality of ejection heads 30 are arranged side by side in a stepped manner in the X direction with respect to the support plate 29, and the heat radiating plate 40 is in surface contact with each ejection head 30.
You may apply to.

In the above embodiment, when the droplet Fb is landed and arranged partially overlapping the previous droplet Fb,
After the previous droplet Fb is fixed to the green sheet 4G, it is arranged to land, but before the previous droplet Fb is fixed to the green sheet 4G, the next droplet Fb is landed and arranged. You may carry out like this.

In the above embodiment, the next droplet Fb is landed and arranged so as to partially overlap the previous droplet Fb, but the next droplet Fb is landed and arranged so as not to partially overlap. You may carry out like.

In the above embodiment, the first droplet Fb to be fixed is overlapped with the previously landed droplet Fb at a pitch that is half of the landing diameter. The degree of overlap may be changed as appropriate.

In the above embodiment, the wiring pattern P is formed by landing so that a part of the droplets Fb sequentially discharged overlaps in order. For example, the wiring pattern P may be formed by discharging the droplets Fb in the order shown in FIGS.

That is, as shown in FIG. 13A, when the previous droplet Fb is landed at a predetermined position for pattern formation, the landing position A1 indicated by a one-dot chain line separated from the landed droplet Fb. Then, the next droplet Fb is landed. When the droplet Fb is disposed at the landing position A1, the droplet Fb to be discharged next is landed at the landing position A2 indicated by a one-dot chain line in FIG. 13B so that a part of the droplet Fb is overlapped with the first droplet Fb. Arrange to land on.

When the droplet Fb is arranged at the landing position A2, the droplet Fb to be discharged next is landed as indicated by a one-dot chain line in FIG. 13C so that a part thereof overlaps the droplet Fb arranged at the landing position A1. The landing is made at position A3. Thereafter, similarly, the landing positions A4 and A5 are arranged in the order shown in FIGS. 13 (d) and 13 (e).
If the droplet Fb is landed on the wiring pattern P, the wiring pattern P of the internal wiring 6 by the droplet Fb can be drawn as shown in FIG.

In the above embodiment, the green sheet 4G is heated by the rubber heater H, but may be heated by other heating means.
In the above embodiment, the droplet discharge means is embodied in the piezoelectric element drive type droplet discharge head 30. 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.

The side sectional view of a circuit module. The whole perspective view of a droplet discharge device. The bottom view which looked at the droplet discharge head from the green sheet side. The principal part sectional side view of a droplet discharge head. The perspective view for demonstrating the attachment state of a discharge head and a carriage. The principal part disassembled perspective view for demonstrating the attachment state of a discharge head and a carriage. The electric block circuit diagram for demonstrating the electrical structure of a droplet discharge apparatus. (A)-(d) is a figure which shows the discharge order of the droplet of a pattern formation. The figure which shows transition of the temperature of a droplet discharge head. Explanatory drawing for demonstrating the structure of the heat sink of another example. The principal part disassembled perspective view for demonstrating the attachment state of the heat sink of another example. The figure which shows the heat sink provided in the discharge head of another example. (A)-(f) is a figure which shows formation of a pattern in another order.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Circuit module, 2 ... LTCC multilayer substrate, 4 ... Low-temperature baking board | substrate, 5 ... Circuit element, 4G
... Green sheet as substrate, 6 ... internal wiring, 20 ... droplet discharge device, 23 ... stage,
28 ... Carriage, 29 ... Support plate, 30 ... Droplet discharge head, 31a ... Nozzle formation surface, 40
... Heat dissipation plate, 41 ... Elongated hole, 42 ... Set screw, 43 ... Heat insulation member, 44 ... Groove, 45 ... Blocking plate, 4
6 ... circulation flow path, 50 ... control device, F ... metal ink as functional liquid, Fb ... droplet, PZ ... piezoelectric element, P ... pattern for wiring, H ... rubber heater, W ... cooling water.

Claims (11)

A pattern forming apparatus for forming a pattern on the substrate by moving a droplet discharge head relative to the substrate and discharging droplets of a functional liquid toward the substrate by the droplet discharge head;
A pattern forming apparatus, wherein a heat radiating means is brought into contact with the droplet discharge head. The pattern forming apparatus according to claim 1,
The droplet discharge head is connected and fixed to a support plate of a carriage that reciprocates,
The pattern forming apparatus, wherein the heat dissipating means is in surface contact with the support plate to be connected and fixed. The pattern forming apparatus according to claim 2,
The pattern forming apparatus, wherein the heat dissipating means is connected and fixed to the support plate so as to be position adjustable. In the pattern formation apparatus of any one of Claims 1-3,
The pattern forming apparatus, wherein the heat dissipating means is a metal. In the pattern formation apparatus of Claim 4,
The pattern forming apparatus, wherein the metal is aluminum. In the pattern formation apparatus of Claim 4,
The said metal is copper, The pattern formation apparatus characterized by the above-mentioned. In the pattern formation apparatus of any one of Claims 1-6,
The pattern forming apparatus, wherein the heat dissipating means is covered with a heat insulating member. In the pattern formation apparatus of any one of Claims 2-7,
The pattern forming apparatus, wherein the support plate is provided with cooling means. The pattern forming apparatus according to claim 8, wherein
The said cooling means consists of a refrigerant | coolant and the circulation flow path for circulating the said refrigerant | coolant formed in the said support plate, The pattern formation apparatus characterized by the above-mentioned. The pattern forming apparatus according to claim 1,
The substrate is a porous substrate and a low-temperature firing sheet composed of ceramic particles and a resin,
The pattern forming apparatus, wherein the functional liquid is a liquid in which metal particles are dispersed as a functional material. A circuit board on which a circuit element is mounted and wiring electrically connected to the mounted circuit element is formed,
A circuit board having wiring formed by the pattern forming apparatus according to claim 1.

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