JP2009142735A - Pattern forming method and pattern forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide pattern forming method and a pattern forming apparatus by which the handleability of a substrate, on which a pattern formed by droplets is drawn, is enhanced to improve a working efficiency. <P>SOLUTION: A green sheet 4G is sucked and fixed to a stage 23 by connecting an air passage S1 to an air suction pump P1 through a solenoid selector valve V1 to make the pressure in the rear surface side of an air permeable porous substrate 24 negative and to diffuse the negative pressure state into the air permeable porous substrate 24 to make the whole rear surface of the green sheet 4G placed on the air permeable porous substrate 24 negative. On the other hand, the green sheet 4G is detached from the stage 23 by connecting the air passage S1 to an accumulation tank T1 through the solenoid selector valve V1 to make the pressure on the rear surface side of the air permeable porous substrate 24 positive and to diffuse the positive pressure state into the air permeable porous substrate 24 to make the whole rear surface of the green sheet 4G placed on the air permeable porous substrate 24 positive. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a pattern forming method and a pattern forming apparatus.

Low temperature co-fired ceramics (LTCC) technology enables the simultaneous firing of a green sheet and a metal, so that an element-embedded substrate incorporating various passive elements between ceramic layers can be realized. In the system-on-package (SOP) mounting technology, this element-embedded substrate (hereinafter simply referred to as an LTCC multilayer substrate) is used in order to reduce the parasitic effects that occur in the combination of electronic components and surface-mounted components. The manufacturing method involved has been intensively developed.

In the manufacturing method of the LTCC multilayer substrate, a drawing process for drawing a pattern such as a passive element or a wiring on each of a plurality of green sheets, a crimping process for laminating a plurality of green sheets having the pattern, and a crimping body, A firing step of batch firing is sequentially performed.

In order to increase the density of various patterns in the drawing process, a so-called ink jet method is proposed in which conductive ink is discharged as fine droplets (for example, Patent Document 1). The ink-jet method uses droplets of several picoliters to several tens of picoliters, and enables pattern miniaturization and narrow pitch by changing the ejection position of the droplets.

In general, when a droplet is ejected using a droplet ejection device to draw a pattern on a green sheet, the stage and the droplet ejection head are moved relative to each other so that the liquid is placed on the upper surface of the green sheet placed on the stage. A droplet of conductive ink is discharged from the droplet discharge head, and a pattern is drawn on the upper surface of the green sheet. At this time, the green sheet placed on the stage is heated to a predetermined temperature so that a pattern is drawn. This is to shorten the drying time of the droplets landed on the green sheet and increase the production efficiency.

In addition, the green sheet used for drawing has a carrier film attached to the back surface thereof in a peelable manner. The carrier film is a plastic film that is used to reinforce and support the green sheet in the drawing process and various subsequent processes, and is peeled off from the green sheet during the laminating process of stacking a plurality of green sheets. It has become.
JP 2005-57139 A

By the way, since the green sheet placed on the stage is drawn and fixed to the stage by a vacuum chuck during drawing, the positioning and fixing are firmly performed and do not shake during drawing. When drawing is completed, the suction operation to the green sheet is stopped, the suction is released, and the green sheet placed on the stage is grasped and removed, and the next new green sheet is placed.

However, when the green sheet drawn from the stage is gripped and removed, the green sheet cannot be removed smoothly, requiring labor and reducing work efficiency. This is because the carrier film adhered to the back surface of the green sheet bites into the suction port of the vacuum chuck while it is adsorbed, and when it is removed, it is caught and cannot be removed smoothly. In particular, since the green sheet is heated, the carrier film is also softened by heating,
It was easy to dig deeper into the suction port of the vacuum chuck.

The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a pattern forming method capable of improving the handling efficiency of a substrate on which a pattern formed by droplets is drawn and improving the working efficiency. And providing a pattern forming apparatus.

The pattern formation method of the present invention is a pattern formation method for drawing a pattern on the upper surface of a substrate placed on a stage by discharging droplets containing conductive fine particles from a droplet discharge head, the lower surface of the substrate The substrate was placed on and fixed to the stage while being dispersed in each of the above positions, and the substrate was heated to draw a pattern on the substrate, and the pattern was drawn on the substrate. Thereafter, the step of dispersing the substrate at each position on the lower surface of the substrate to bring it into a positive pressure state and detaching the substrate from the stage.

According to the pattern forming method of the present invention, when a pattern is drawn, the entire back surface of the substrate is in a negative pressure state, and the entire back surface of the substrate is sucked on average. The substrate can be securely fixed to the stage without applying force to the substrate.

In addition, after the pattern is drawn on the substrate, the entire back surface of the substrate is in a positive pressure state so that the substrate can be lifted, and the handling work of picking up the substrate from the stage should be performed very smoothly. Can do. In addition, since the entire back surface of the substrate is brought into a positive pressure state on average, a large local force that deforms the substrate is not applied to the substrate, and the substrate can be detached from the stage.

In this pattern forming method, the substrate is a low-temperature firing sheet composed of ceramic particles and a resin, and the conductive fine particles contained in the droplets are metal fine particles dispersed in the droplets. Good.

According to this pattern forming method, the low-temperature firing sheet can be reliably fixed to the stage without receiving a large local force that causes deformation. In addition, the low-temperature firing sheet can be handled smoothly without receiving a large local force that causes the handling operation to be taken up from the stage to be deformed.

In the pattern forming apparatus of the present invention, the stage and the droplet discharge head are moved relative to each other, and droplets containing conductive fine particles are discharged from the droplet discharge head onto the upper surface of the substrate placed on the stage. A pattern forming apparatus for drawing a pattern on an upper surface of the substrate, the breathable porous member being placed on the substrate placing portion of the stage and placing the substrate, and the breathable porous member An adsorbing means for adsorbing and fixing the substrate to the stage with a negative pressure on the lower surface of the substrate placed on the air-permeable porous member; and the air-permeable porous member via the air-permeable porous member Desorption means for desorbing the substrate from the stage with a positive pressure on the lower surface of the substrate placed on the material member is provided.

According to the pattern forming apparatus of the present invention, when the pattern is drawn, the lower surface of the substrate placed on the breathable porous member by the adsorbing means is in a negative pressure state. At this time, since the air-permeable porous member is a gas-permeable porous material, the negative pressure state diffuses in the air-permeable porous member and the back surface of the substrate placed on the air-permeable porous member. The whole is in a negative pressure state.

Therefore, since the entire back surface of the substrate is sucked on average, a large local force that deforms the substrate is not applied to the substrate, and the substrate is reliably fixed to the stage.
In addition, when the drawing of the pattern is finished, the lower surface of the substrate placed on the breathable porous member is put into a positive pressure state by the detaching means, so that the back surface of the substrate becomes a positive pressure state. Therefore, the handling operation of picking up the substrate from the stage can be performed very smoothly.

In addition, since the air-permeable porous member is porous having air permeability, the positive pressure state diffuses in the air-permeable porous member and the entire lower surface of the substrate placed on the air-permeable porous member. To a positive pressure state. Therefore, since the entire back surface of the substrate is floated on the average, a large local force that deforms the substrate is not applied to the substrate.

In this pattern forming apparatus, the stage may be provided with heating means for heating the air-permeable porous member and heating the substrate through the air-permeable porous member.
According to this pattern forming apparatus, since the substrate is heated, the landed droplets are quickly dried, so that the pattern can be formed in a short time.

In this pattern forming apparatus, the breathable porous member may be a porous ceramic substrate.
According to this pattern forming apparatus, the low-temperature firing sheet can be reliably fixed to the stage without applying a large local force that causes deformation. In addition, the handling operation of picking up the low-temperature firing sheet from the stage can be performed smoothly without applying a large local force to the low-temperature firing sheet.

In this pattern forming apparatus, the substrate may be a low-temperature firing sheet composed of ceramic particles having a support sheet attached to the lower surface and a resin.
According to this pattern forming apparatus, the support sheet attached to the lower surface of the low-temperature firing sheet is
The entire back surface is in a negative pressure state on average, and the entire back surface is in a positive pressure state on average.

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 board), and an embodiment embodied in the formation of a wiring pattern drawn on a plurality of low-temperature firing sheets (green sheets) constituting the LTCC multilayer board. 1 to 8 will be described.

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.

And as for the low-temperature baking board | substrate 4, the thing before the sintering is called the green sheet 4G (refer FIG.2,4,5) as a sheet | seat for low-temperature baking. 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 dried into a plate shape, and has air permeability. . That is, the green sheet 4G is a breathable substrate.

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 and silver alloy, and wiring pattern formation using a droplet discharge device 20 as a pattern forming device shown in FIG. Formed by the method.

FIG. 2 is an overall perspective view illustrating a droplet discharge device 20 as a pattern forming device.
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 arrow direction) is formed on the upper surface of the base 21. Above the guide groove 22, a stage 23 that moves along the guide groove 22 in the Y arrow direction and the counter-Y arrow direction is provided.

The stage 23 mounts a green sheet 4G, which is the low-temperature fired substrate 4 before firing, on its upper surface. As shown in FIG. 4, the green sheet 4 </ b> G placed on the stage 23 has a carrier film 4 </ b> F as a support sheet attached to the back surface in a peelable manner.

The carrier film 4F is a film for supporting the green sheet 4G in the drawing process and various subsequent processes. For example, a plastic film excellent in peelability from the green sheet 4G and mechanical resistance in each process can be used. . Carrier film 4F
For example, a polyethylene terephthalate film, a polyethylene naphthalate film, a polyethylene film, or a polypropylene film can be used.

The green sheet 4G is a layer made of a glass ceramic composition containing glass ceramic powder, a binder, and the like. The film thickness of the green sheet 4G is several tens of μm when the capacitor element is formed as the circuit element 5, and is formed to be 100 μm to 200 μm in the other layers. The green sheet 4G is a state in which a glass ceramic composition slurried with a dispersion medium is applied onto a carrier film 4F using a sheet forming method such as a doctor blade method or a reverse roll coater, and the applied film can be handled. Obtained by drying.

As the dispersion medium, for example, a surfactant, a silane coupling agent, or the like can be used as long as it can uniformly disperse the glass ceramic powder.
The glass ceramic powder is a powder having an average particle diameter of 0.1 μm to 5 μm. For example, a glass composite ceramic obtained by mixing borosilicate glass with ceramic powder such as alumina or forsterite can be used. As the glass ceramic powder, ZnO-M
BaO, a crystallized glass ceramic using gO-Al2O3-SiO2 based crystallized glass
-Al2O3-SiO2 ceramic powder and Al2O3-CaO-SiO2-MgO-B
Non-glass ceramics using 2O3 ceramic powder or the like may be used.

The binder is an organic polymer that functions as a binder for the glass ceramic powder and can be easily decomposed and removed in a subsequent firing step. As the binder, for example, butyral,
Binder resins such as acrylic and cellulose can be used. Examples of the acrylic binder resin include alkyl (meth) acrylate, alkoxyalkyl (meth) acrylate, polyalkylene glycol (meth) acrylate, and cycloalkyl (meth).
A homopolymer of a (meth) acrylate compound such as acrylate can be used. Moreover, as an acrylic binder resin, it can be obtained from a copolymer obtained from two or more of the (meth) acrylate compounds, or from other copolymerizable monomers such as (meth) acrylate compounds and unsaturated carboxylic acids. Can be used.

The binder is, for example, an adipate ester plasticizer, dioctyl phthalate (DO
P), a dibutyl phthalate (DBP) phthalate ester plasticizer, and a plasticizer such as a glycol ester plasticizer may be contained.

As shown in FIG. 5, the stage 23 includes a stage main body 23a and the stage main body 23a.
A rubber heater H serving as a heating means and a breathable porous substrate 24 serving as a breathable porous member are stacked in a fitting recess 23b formed on the upper surface.

The stage main body 23a is disposed on the upper surface of the base 21, and moves in the Y arrow direction and the anti-Y arrow direction along the guide groove 22 based on the driving of a Y-axis motor MY described later. The rubber heater H is disposed at the bottom of a fitting recess 23b that is recessed on the upper surface of the stage body 23a. The breathable porous substrate 24 is laminated on the upper surface of the rubber heater H, which is a fitting recess 23b. Further, the upper surface of the breathable porous substrate 24 is flush with the upper surface of the stage main body 23a.

The air-permeable porous substrate 24 is a ceramic substrate and is formed of a porous substrate having air permeability, and a green sheet 4G having a carrier film 4F attached thereon is placed on the entire upper surface thereof. The breathable porous substrate 24 is heated by a rubber heater H, and the green sheet 4G is heated to a predetermined temperature by the heat of the heated breathable porous substrate 24.

Further, as shown by a broken line in FIG. 5, the stage main body 23a is formed with an air flow path S1 that communicates with the bottom surface of the fitting recess 23b. The rubber heater H communicates with the air flow path S1 and communicates with the lower surface of the air-permeable porous substrate 24 disposed on the upper surface of the rubber heater H.
Is formed.

The air flow path S1 of the stage main body 23a is connected to a tube TU whose base end opening end is connected to the side surface of the stage main body 23a. The tube TU is connected via an electromagnetic switching valve V1 to an air suction pump P1 that constitutes an adsorbing means that sucks air and a pressure accumulation tank T1 that accumulates nitrogen gas.

When the air flow path S1 is connected to the air suction pump P1 via the electromagnetic switching valve V1, the tube TU and the air flow path S are driven by driving the air suction pump P1.
1. The back side of the air-permeable porous substrate 24 is brought into a negative pressure state through the communication path S2. At this time, since the air-permeable porous substrate 24 is a gas-permeable porous substrate, the negative pressure state diffuses in the gas-permeable porous substrate 24 and is placed on the gas-permeable porous substrate 24. Green sheet 4G (
The entire back surface of the carrier film 4F) is in a negative pressure state, and the green sheet 4G is placed on the stage 2
3. Fix to 3 with suction.

On the contrary, when the air flow path S1 is connected to the pressure accumulation tank T1 constituting the desorption means via the electromagnetic switching valve V1, the nitrogen gas accumulated in the pressure accumulation tank T1 becomes the tube TU, the air flow path S1, the communication path. It is led out to the back surface of the breathable porous substrate 24 through S2, and the back surface side is brought into a pressurized (positive pressure) state. At this time, since the air permeable porous substrate 24 is a gas permeable porous substrate, the positive pressure state diffuses in the gas permeable porous substrate 24, and the gas permeable porous substrate 24.
The entire back surface of the green sheet 4G (carrier film 4F) placed thereon is brought into a positive pressure state, and the green sheet 4G is detached from the stage 23.

As shown in FIG. 2, a gate-type guide member 25 is installed on the base 21 so as to straddle a direction orthogonal to the Y arrow direction (X arrow direction). On the upper side of the guide member 25, an ink tank 26 extending in the X arrow direction is disposed. The ink tank 26 stores the metal ink F (see FIG. 4), and the stored metal ink F is 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 dispersion metal ink in which metal fine particles as conductive fine particles, for example, metal fine particles 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.

The metal ink F that has landed on the green sheet 4G evaporates part of the solvent or dispersion medium from the surface side. At this time, since the green sheet 4G is heated by the rubber heater H through the breathable porous substrate 24, evaporation of the solvent or the dispersion medium is promoted.

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. Even if the metal ink F in the pinned state is fixed to the green sheet 4G and overprinted, it is fixed to the green sheet 4G, and the outer diameter of the droplet Fb does not change. It is not attracted to the droplet Fb.

The guide member 25 is formed with a pair of upper and lower guide rails 28 extending in the X arrow direction over substantially the entire width in the X arrow direction. The pair of upper and lower guide rails 28 includes a carriage 2
9 is attached. The carriage 29 is guided by the guide rail 28 and moves in the X arrow direction and the counter X arrow direction. A droplet discharge head 30 is mounted on the carriage 29.

3 shows a bottom view of the ejection head 30 as viewed from the green sheet 4G side, and FIG. A nozzle plate 31 is provided below the discharge head 30. The lower surface (nozzle formation surface 31a) of the nozzle plate 31 has a green sheet 4G.
Are formed substantially parallel to the upper surface (discharge surface 4Ga). When the green sheet 4G is positioned immediately below the ejection head 30, the nozzle plate 31 holds a distance (platen gap) between the nozzle formation surface 31a and the ejection surface 4Ga at a predetermined distance (for example, 600 μm).

In FIG. 3, a pair of nozzle rows NL made up of a plurality of nozzles N arranged along the direction of the arrow Y are formed on the nozzle forming surface 31a. Each pair of nozzle rows NL has 1
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, each nozzle N of one nozzle row NL is viewed from the Y arrow direction.
Interpolation is performed between the nozzles N of the other nozzle row NL. In other words, the ejection head 30 has 180 × 2 = 360 nozzles N per inch in the Y arrow direction (the maximum resolution is 36).
0 dpi).

In FIG. 4, a supply tube 30 </ b> T is connected to the upper side of the discharge head 30. The supply tube 30T is disposed so as to extend in the Z arrow direction, and supplies the metal ink F from the ink tank 26 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 droplet Fb flies in the direction opposite to the arrow Z of the corresponding nozzle N, and the green sheet 4G
Land on the discharge surface 4Ga.

Next, the electrical configuration of the droplet discharge device 20 configured as described above will be described with reference to FIG.
In FIG. 6, the control device 50 has a CPU 50A, a ROM 50B, a RAM 50C, and the like. In accordance with the stored various data and various control programs, the control device 50 performs the transport process of the stage 23, the transport process of the carriage 29, the droplet discharge process of the discharge head 30, the heating process of the rubber heater H, the air suction pump P1 and the pressure accumulation. A switching process of the tank T1 is executed.

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 (ejection surface 4Ga) through which each nozzle N passes. That is, the bitmap data BD is data for discharging the wiring droplet Fb to the target formation position of the internal wiring 6 defined on the discharge surface 4Ga.

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. The X-axis motor drive circuit 52 is connected to the control device 5
In response to the drive control signal from 0, the X-axis motor MX for moving the carriage 29 is rotated forward or reverse. A Y-axis motor drive circuit 53 is connected to the control device 50. The control device 50 outputs a drive control signal to the Y-axis motor drive circuit 53. In response to the drive control signal from the control device 50, the Y-axis motor drive circuit 53 responds to the stage 23 (stage body 23).
The Y-axis motor MY for moving a) is rotated forward or reverse.

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 generates a pattern formation control signal SI synchronized with a predetermined frequency using the bitmap data BD, and serially transfers the pattern formation control signal SI to the head drive circuit 54. The head drive circuit 54 receives the pattern formation control signal SI from the control device 50.
Are sequentially converted into serial / parallel corresponding to each piezoelectric element PZ. Each time the head drive circuit 54 receives the ejection timing signal LT from the control device 50, the head drive circuit 54 latches the serial / parallel converted pattern formation control signal SI and applies it to each piezoelectric element PZ selected by the pattern formation control signal SI. A drive voltage COM is supplied.

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 a drive control signal from the control device 50, the rubber heater drive circuit 55 drives the rubber heater H to bring the green sheet 4G placed on the stage 23 (breathable porous substrate 24) to a predetermined temperature. The heating is controlled so that

In the present embodiment, the predetermined temperature of the green sheet 4G (temperature of the ejection 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 ( The temperature is controlled to be a temperature of less than the lowest boiling point in the liquid composition. That is, the metal ink F when the green sheet 4G is discharged from the discharge head 30.
When the liquid is heated to a temperature equal to or higher than that temperature and is not discharged by the discharge head 30, the landed droplet Fb is quickly heated and dried at a temperature higher than that, and the green sheet 4G is less than the boiling point of the droplet Fb. The landed droplet Fb is prevented from bumping on the green sheet 4G.

A suction pump drive circuit 56 is connected to the control device 50. The control device 50 outputs a drive control signal to the suction pump drive circuit 56. The suction pump drive circuit 56 is connected to the control device 5.
In response to the drive control signal from 0, the air suction pump P1 is driven and the air-permeable porous substrate 2 is driven.
The green sheet 4G placed on the stage 4 is controlled to be placed on and fixed to the stage 23 in a predetermined negative pressure state.

A valve drive circuit 57 is connected to the control device 50. The control device 50 outputs a drive control signal to the valve drive circuit 57. The valve drive circuit 57 switches and controls the electromagnetic switching valve V <b> 1 in response to the drive control signal from the control device 50. And the electromagnetic switching valve V1
Then, the air flow path S1 of the stage main body 23a is connected to either the air suction pump P1 or the pressure accumulation tank T1, and the green sheet 4G is fixed to or detached from the stage 23.

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 2 so that the discharge surface 4Ga is on the upper side.
3 (breathable porous substrate 24). At this time, the stage 23 is the green sheet 4
G is arranged at the home position of the carriage 29 in the direction opposite to the arrow Y. The green sheet 4G has a via hole 7, a via wiring 8 is formed in the via hole 7, and an internal wiring 6 is formed on the discharge 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 connects the electromagnetic switching valve V1 via the valve drive circuit 57 to the air flow path S1.
The green sheet 4G (carrier film 4F) placed on the breathable porous substrate 24 by driving the air suction pump P1 via the suction pump drive circuit 56. The back surface of the is controlled to be in a negative pressure state.

Further, the control device 50 drives the rubber heater H provided on the stage main body 23a via the rubber heater driving circuit 55, and the entire green sheet 4G reaches the predetermined temperature uniformly via the breathable porous substrate 24. So that the heating is controlled. That is, the discharge surface 4 of the green sheet 4G
Ga is controlled to be a temperature not lower than the temperature of the metal ink F when discharged from the discharge head 30 and lower than the boiling point of the liquid composition contained in the metal ink F (less than the lowest boiling point in the liquid composition). ing.

That is, at this time, the green sheet 4G is fixed to the stage 23 and is controlled to be heated to a predetermined temperature.
Next, the control device 50 determines that the ejection head 30 has a predetermined position immediately above the green sheet 4G.
The Y-axis motor MY is driven via the Y-axis motor drive circuit 53 so as to pass in the arrow direction, and the stage 23 is conveyed. Then, the control device 50 passes the X-axis motor drive circuit 52 through the X-axis motor drive circuit 52.
The shaft motor MX is driven to start scanning (forward movement) of the ejection head 30.

When the control device 50 starts scanning (forward movement) of the ejection head 30, the control device 50 generates a pattern formation control signal SI based on the bitmap data BD, and drives the pattern formation control signal SI and the drive voltage COM. Output to the circuit 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 is positioned at the landing position for forming the internal wiring 6, the liquid is discharged from the selected nozzle N. The droplet Fb is discharged. The droplets Fb that have landed on the green sheet 4G are heated to a temperature equal to or higher than the temperature of the droplets Fb at the time of discharge, and thus drying starts and is quickly dried.

In the present embodiment, as shown in FIGS. 7 and 8A to 8D, each droplet Fb to be ejected sequentially reaches a landing position for forming the corresponding internal wiring 6. In detail,
In the present embodiment, the droplets Fb landed and arranged first for pattern formation are partially dried and fixed (pinned) to the green sheet 4G (in a state where their own wetting and spreading are stopped). 7 and FIG. 8 (a) so that a part of the droplet Fb discharged from the next discharge head 30 and landing on the green sheet 4G overlaps the previous droplet Fb. The ink is ejected from the ejection head 30 at a position indicated by a chain line.

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. In addition, the next droplet Fb that has been landed and disposed so as to partially overlap is immediately dried and quickly fixed in a non-overlapping portion because the green sheet 4G is heated. 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 ejection head 30 in the X arrow direction are dried without shifting 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.

When the ejection head 30 completes scanning from end to end of the green sheet 4G, that is, the control device 50 scans (forwards) the ejection head 30 in the direction of the arrow X, and the first droplet F
When the operation of b is completed, the stage is driven by driving the Y-axis motor MY via the Y-axis motor drive circuit 53 in order to discharge the droplet Fb to a new position on the green sheet 4G for forming the internal wiring 6. After transporting 23 by a predetermined amount in the Y direction, the ejection head 30 is scanned (returned) in the anti-X arrow direction.

When scanning (return) of the ejection head 30 is started, the control device 50 drives and controls each piezoelectric element PZ via the head drive circuit 54 based on the bitmap data BD as described above.
Each time the ejection head 30 is positioned at the landing position for forming the internal wiring 6, the droplet Fb is ejected from the selected nozzle N. Also in this case, the green sheet 4 is first formed in the same manner as described above.
The droplets Fb that have landed on G immediately start drying and are quickly dried. When the droplet Fb is fixed to the green sheet 4G, the droplet F that has entered the fixed state
The next droplet Fb is landed and arranged so that part of it overlaps b.

Thereafter, the ejection head 30 is reciprocated in the X arrow direction and the counter-X arrow direction, the stage 23 is conveyed in the Y arrow direction, and the timing of the droplet Fb based on the bitmap data BD during the reciprocation of the ejection head 30. 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 drawing of the wiring pattern P on the green sheet 4G is completed, the control device 50 moves and arranges the stage 23 at the position (home position) shown in FIG. 2 where the green sheet 4G is first placed on the stage 23. When the stage 23 is disposed at the home position shown in FIG. 2, the control device 50 stops driving the air suction pump P <b> 1 via the suction pump drive circuit 56.

Subsequently, the control device 50 controls the electromagnetic switching valve V1 through the valve driving circuit 57 so that the air flow path S1 and the pressure accumulating tank T1 are connected, and the green sheet placed on the breathable porous substrate 24. The back surface of 4G (carrier sheet 4F) is controlled to be in a positive pressure state.

By making the back surface of the green sheet 4G into a positive pressure state, the green sheet 4G is released from the stage 23 (breathable porous substrate 24) and can be detached. At this time, since the back surface of the green sheet 4G is in a positive pressure state and the green sheet 4G appears to float, the handling work of picking up the green sheet 4G from the stage 23 can be performed very smoothly. .

Next, effects of the embodiment configured as described above will be described below.
(1) According to the above-described embodiment, when the drawing of the wiring pattern P on the green sheet 4G is completed, the electromagnetic switching valve V1 is switched so that the air flow path S1 and the pressure accumulation tank T1 are connected, Nitrogen gas was placed on the back surface of the green sheet 4G (carrier film 4F) placed on the breathable porous substrate 24 so as to be in a positive pressure state.

Accordingly, since the back surface of the green sheet 4G (carrier film 4F) is in a positive pressure state and the green sheet 4G appears to float, the handling work of picking up the green sheet 4G from the stage 23 should be performed very smoothly. Can do.

Moreover, since the air permeable porous substrate 24 is a gas permeable porous substrate, the positive pressure state diffuses in the gas permeable porous substrate 24 and is placed on the gas permeable porous substrate 24. The entire back surface of the green sheet 4G (carrier film 4F) is brought into a positive pressure state.

Accordingly, since the entire back surface of the green sheet 4G (carrier film 4F) is floated on average, a large local force is not applied to the green sheet 4G. Therefore, the green sheet 4G is detached from the stage 23 without being deformed. be able to.

(2) According to the above embodiment, when the wiring pattern P is drawn on the green sheet 4G, the electromagnetic switching valve V1 is switched so that the air flow path S1 and the air suction pump P1 are connected, and the air suction pump P1. Was driven so that the back surface of the green sheet 4G (carrier film 4F) placed on the breathable porous substrate 24 was in a negative pressure state. At this time,
Since the air permeable porous substrate 24 is a porous substrate having air permeability, the negative pressure state diffuses in the air permeable porous substrate 24 and is placed on the air permeable porous substrate 24. 4
The entire back surface of G (carrier film 4F) is brought into a negative pressure state.

Accordingly, since the entire back surface of the green sheet 4G (carrier film 4F) is sucked on average, a large local force is not applied to the green sheet 4G, so that the green sheet 4G is reliably deformed to the stage 23 without being deformed. It is fixed by suction.

(3) According to the above embodiment, since the green sheet 4G is heated, the landed droplet Fb
Is quickly dried, the discharge timing of the droplet Fb to be landed next can be shortened, and the wiring pattern P can be formed in a short time.

In addition, you may change the said embodiment as follows.
In the above embodiment, the breathable porous substrate 24 is formed of a breathable porous ceramic substrate. However, the present invention is not limited to this, and is negatively distributed to each position on the back surface of the green sheet 4G. Any structure can be used as long as it is a pressure state and a positive pressure state.

In the above embodiment, the stage 23 is fitted with the fitting recess 23b formed in the stage main body 23a.
In addition, a rubber heater H and a breathable porous substrate 24 were accommodated. For example, the rubber heater H may be disposed on the upper surface of the stage main body 23a, and the breathable porous substrate 24 may be disposed on the upper surface of the rubber heater H in order.

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 green sheet 4G is heated by the rubber heater H, but may be heated by other heating means.
In the above embodiment, the functional liquid is embodied as the metal ink F. For example, the present invention may be embodied in a functional liquid containing a liquid crystal material. That is, any functional liquid that is ejected to form a pattern may be used.

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. Explanatory drawing for demonstrating the structure of a stage. The electric block circuit diagram for demonstrating the electrical structure of a droplet discharge apparatus. Explanatory drawing for demonstrating the effect | action of pattern formation. (A)-(d) is a figure which shows the discharge order of the droplet of a pattern formation.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Circuit module, 2 ... LTCC multilayer substrate, 4 ... Low-temperature baking board | substrate, 4G ... Green sheet, 4F ... Carrier film, 6 ... Internal wiring, 20 ... Droplet discharge apparatus, 23 ... Stage, 2
3a ... stage body, 23b ... fitting recess, 24 ... breathable porous substrate, 30 ... droplet discharge head, 50 ... control device, F ... metal ink, Fb ... droplet, H ... rubber heater, PZ ... piezoelectric element , P ... pattern, H ... rubber heater, P1 ... air suction pump, T1 ... pressure accumulation tank, V1
... Electromagnetic switching valve.

Claims (6)

A pattern forming method for drawing a pattern on an upper surface of a substrate placed on a stage by discharging droplets containing conductive fine particles from a droplet discharge head,
Dispersing at each position on the lower surface of the substrate in a negative pressure state, placing and fixing the substrate on the stage, heating the substrate, and drawing a pattern on the substrate;
A pattern forming method, comprising: after the pattern is drawn on the substrate, dispersed in each position on the lower surface of the substrate to be in a positive pressure state, and detaching the substrate from the stage. In the pattern formation method of Claim 1,
The substrate is a low-temperature firing sheet composed of ceramic particles and a resin,
The pattern forming method, wherein the conductive fine particles contained in the droplets are metal fine particles and are dispersed in the droplets. By moving the stage and the droplet discharge head relative to each other, on the upper surface of the substrate placed on the stage,
A pattern forming apparatus for drawing a pattern on an upper surface of the substrate by discharging a droplet containing conductive fine particles from the droplet discharge head,
A breathable porous member provided on the substrate mounting portion of the stage and mounting the substrate;
An adsorbing means for adsorbing and fixing the substrate to the stage with a negative pressure on the lower surface of the substrate placed on the air-permeable porous member via the air-permeable porous member;
Desorption means for detaching the substrate from the stage with a positive pressure on the lower surface of the substrate placed on the breathable porous member is provided via the breathable porous member. Pattern forming apparatus. In the pattern formation apparatus of Claim 3,
A pattern forming apparatus, wherein the stage is provided with heating means for heating the air-permeable porous member and heating the substrate through the air-permeable porous member. In the pattern formation apparatus of Claim 3 or 4,
The air-permeable porous member is a porous ceramic substrate. In the pattern formation apparatus of any one of Claims 3-5,
The said board | substrate is a sheet | seat for low-temperature baking comprised from the ceramic particle | grains by which the support sheet was stuck to the lower surface, and resin, The pattern formation apparatus characterized by the above-mentioned.

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