JP2006007163A - Spray coating apparatus and spray coating method using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To form a coat with a uniform thickness on the surface of a work such as a substrate. <P>SOLUTION: A spray coating apparatus has a work supporting table 3 in a coating chamber 1 and sprays a coating liquid on a work 2 loaded on the work supporting table 3 to make the coat on the surface of the work 2. And this apparatus is equipped with a coating nozzle 5 spraying the coating liquid on the work 2, a solvent supplying nozzle 8, 8 spraying a solvent contained in the coating liquid outside 7 spraying area of the coating liquid, in the coating chamber 1, and further equipped with a means 11 discharging a misty sprayed solvent 9a outside the chamber and a means 14 controlling a concentration of the solvent outside 7 spraying area in the chamber 1. A spray coating method has a step spraying of the coating liquid from the coating nozzle 5 to form the coat on the surface of the work 2 loaded on the work supporting table 3 while controlling the concentration, outside 7 spraying area, of the solvent sprayed from the solvent supplying nozzle 8, 8. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a spray coating apparatus used for spraying a coating liquid onto a workpiece such as a silicon substrate to form a coating film, and a spray coating method using the same.

As a conventional coating apparatus, there are a turntable arranged in a coating chamber, a coating nozzle for dropping a coating solution onto the surface of a work detachably fixed to the turntable, and a solvent having a high concentration in the coating chamber. The thing provided with the solvent spray nozzle which sprays is known (for example, refer patent document 1). In order to spin-coat a coating film on a workpiece using this coating apparatus, after dripping the coating liquid from the coating nozzle onto the workpiece fixed to the rotary table, the rotary table is rotated at a high speed and the solvent spray nozzle is used. After a solvent having a high concentration is sprayed into the coating chamber and filled with a solvent gas atmosphere, the rotating table is stopped to form a coating film on the surface of the workpiece.
However, when such a coating apparatus is used, an air flow of a solvent gas is generated in the coating chamber, and thus application unevenness occurs due to the air flow when the coating liquid is applied. Also, with solvent gas, if the inside of the coating chamber is heated or the internal pressure is low, the solvent concentration of the gas will drop rapidly, making it difficult to control the solvent concentration inside the chamber and causing coating unevenness. Resulting in.

As another example of a conventional coating apparatus, a rotary coating apparatus as shown in FIG. 6 is known (see, for example, Patent Document 2).
The rotary coating apparatus of FIG. 6 includes a rotary table 102 disposed in the coating chamber 105, and a two-fluid nozzle that sprays a coating liquid together with a solvent vapor onto the surface of a work 101 held by suction on the rotary table 102. The spray nozzle 104 is provided. The spray nozzle 104 has an injection port 104a into which solvent vapor is injected from the solvent vapor supply source 108, an injection port 104b into which coating liquid is injected from the coating liquid supply source 109, and one injection port 104c.
In order to spray coat the surface of the workpiece 101 using this rotary coating apparatus, the rotating table 102 holding the workpiece 101 is rotated by the suction, and the spray nozzle 104 sprays on the rotating workpiece 101. A coating solution is formed on the surface of the workpiece 101 by spraying the coating solution together with the solvent vapor from the opening 104 c in the form of a mist and depositing the coating solution on the surface of the workpiece 101.
JP-A-5-259050 Japanese Patent Laid-Open No. 9-029158

  However, when the coating apparatus of FIG. 6 is used, when applying the coating liquid to the workpiece 101, the spray method is used, and the coating liquid is sprayed together with the solvent vapor, so that the solvent concentration in the chamber has elapsed over time. (The difference in the solvent concentration is particularly large in the first half and the second half of the application), resulting in a difference in the drying speed of the solvent, resulting in coating unevenness. Since the concentration of the solvent is close to 0 immediately after the start of application, if the application liquid is sprayed from the spray nozzle 104 in this state, the coating film is dried immediately, and the concentration of the solvent becomes higher at the end of application. This is because the drying speed of the coating film becomes slow (because the inside of the coating chamber is filled with the solvent).

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a spray coating apparatus capable of forming a coating film having a uniform thickness on the surface of a workpiece such as a substrate, particularly a workpiece having irregularities.
Another object of the present invention is to provide a spray coating method capable of forming a coating film having a uniform thickness on the surface of a workpiece such as a substrate.

The spray coating apparatus of the present invention has a work support base in the coating chamber, and spray coats a coating liquid onto the work placed on the work support base to form a coating film on the surface of the work. A device,
A coating nozzle that sprays the coating liquid onto the workpiece and a solvent supply nozzle that sprays a solvent of the coating liquid outside the spray spray area of the coating liquid are provided in the coating chamber,
Further, means for discharging the sprayed mist solvent out of the coating chamber and means for controlling the concentration of the solvent outside the spray spray area in the coating chamber are provided.

In the spray coating apparatus of the present invention having the above-described configuration, the solvent sprayed from the solvent supply nozzle is preferably the same type as the solvent contained in the coating liquid sprayed from the coating nozzle, more preferably the same. It is desirable that Here, the same type of solvent includes the case where the concentration is different even though the component names are the same.
In the spray coating apparatus of the present invention configured as described above, it is preferable to use an ultrasonic atomizing nozzle or a dropping nozzle that does not affect the air flow in the spray spray area as the solvent supply nozzle.
Moreover, in the spray coating apparatus of the present invention having any one of the above structures, the solvent mist sprayed from the solvent supply nozzle preferably has a particle size of 60 μm or less.

The spray coating method of the present invention uses the spray coating apparatus of the present invention having any one of the above configurations, and controls the application while controlling the concentration of the solvent sprayed from the solvent supply nozzle outside the spray spraying area. And spraying the coating liquid from a nozzle for forming a coating film on the surface of the work placed on the work support.
Moreover, in the spray coating method of the present invention having the above-described configuration, the method includes the step of spraying the solvent from the solvent supply nozzle and supplying it to the surface of the workpiece before the step of forming a coating film on the surface of the workpiece. It is preferable.
In the spray coating method of the present invention having any one of the above structures, after the step of forming a coating film on the surface of the workpiece, the solvent is sprayed onto the surface of the workpiece from the solvent supply nozzle. It is preferable to provide a step of smoothing the surface of the film.

Further, a method for manufacturing a three-dimensional circuit board according to the present invention is a method for manufacturing a three-dimensional circuit board using the pre-coating method of the present invention having any one of the above-described configurations,
A coating liquid composed of a resist and a solvent thereof is used as the coating liquid, and a work having irregularities on the surface is used as the work placed on the work support.
Moreover, in the manufacturing method of the three-dimensional circuit board of the said structure, it is preferable to provide the process of forming a circuit pattern with a photolithographic technique after the process of forming a coating film on the surface of the said workpiece | work.

In the spray coating apparatus of the present invention, a coating nozzle for spraying the coating liquid onto the workpiece and a solvent supply nozzle for spraying a solvent of the coating liquid outside the spray spray area of the coating liquid are disposed in the coating chamber. A means for discharging the sprayed mist-like solvent out of the coating chamber (a mist-like solvent discharging means); and a concentration of the solvent outside the spray spray area of the coating liquid in the coating chamber. Since the control means (solvent concentration control means) is provided, the solvent concentration outside the spray spray area of the coating liquid is detected by the organic solvent sensor, and the detected value of the solvent concentration is outside the desired range. In some cases, the solvent concentration control means controls the amount of solvent sprayed from the solvent supply nozzle and the amount of atomized solvent discharged from the mist-like solvent discharge means. Allows controlled to the spray coating liquid, or solvent concentration of the coating chamber before and after spraying of the coating solution has a desired concentration.
Further, since the solvent is sprayed outside the spray spray area of the coating liquid, even if the solvent is sprayed while spraying the coating liquid onto the workpiece, the spray spray area of the coating liquid is affected by the air current caused by the atomized solvent. Hateful.
Also, by spraying the solvent from the solvent supply nozzle before, during or after spraying the coating liquid, the solvent particles can be sprayed directly onto the workpiece, and the work to improve the uniformity of the coating film is performed. Can do.
Therefore, according to the spray coating apparatus of the present invention, the influence of the air current due to the mist-like solvent is hard to give to the spray spray area of the coating liquid, and the solvent in the coating chamber before or after spraying the coating liquid is sprayed. Since it can control so that a density | concentration may become a desired density | concentration, the drying speed of a coating liquid can be controlled and a uniform coating film can be formed on the surface of workpiece | work, such as a board | substrate.

Further, according to the spray coating method of the present invention, the concentration of the solvent sprayed from the solvent supply nozzle outside the spray spray area is controlled using the spray coating apparatus of the present invention having any one of the above configurations. While having a step of spraying the coating liquid from the coating nozzle and forming a coating film on the surface of the work placed on the work support, the drying speed of the coating liquid can be controlled, A uniform coating film can be formed on the surface of a workpiece such as a substrate.
For example, after spraying a mist of solvent from the solvent supply nozzle to adjust the inside of the coating chamber to a target solvent concentration to a certain extent, spraying of the mist of the coating liquid from the coating nozzle is started. The drying rate of the coating film can be balanced by forcibly exhausting the mist solvent from the solvent discharge means.
Also, when making the coating film formed on the surface of the workpiece uniform, increase the amount of mist solvent sprayed from the solvent supply nozzle to increase the solvent concentration in the coating chamber, thereby suppressing the drying of the coating film. With this, it is possible to promote the binding of the paint.
When accelerating the drying of the coating film formed on the surface of the workpiece by spraying the coating liquid from the coating nozzle onto the workpiece placed on the workpiece support in the coating chamber, the mist from the solvent supply nozzle By stopping the spraying of the solvent and forcibly exhausting the atomized solvent by the atomized solvent discharging means to reduce the solvent concentration in the coating chamber, drying of the coating film can be promoted.
In addition, when the workpiece forming the coating film has irregularities or slopes on the surface, when increasing the film thickness of the coating film to be formed on the top surface, the mist-like spraying from the solvent supply nozzle at the beginning of application The amount of the solvent is increased to increase the concentration of the solvent in the coating chamber, and the mist-like coating liquid and the mist-like solvent adhering to the top surface are caused to flow on the slope. In addition, when the coating film on the slope is thicker than the top surface, the solvent concentration in the coating chamber is not so high.
In the present invention, the spray spraying solvent (the solvent contained in the coating liquid sprayed from the coating nozzle) and the solvent supplied outside the spray spraying area of the coating liquid are used as the solvent for the coating liquid. It doesn't have to be the same. However, if the solvent for spraying and the solvent supplied to the outside of the spraying area are the same type, preferably the same solvent, the configuration of the apparatus becomes simple and the control becomes easy.

Next, embodiments of the present invention will be described in detail with reference to the drawings.
The present invention is of course not limited to the embodiments described below, and in the following drawings, the constituent parts are shown so that the scale of each constituent part can be easily shown in the drawings. The scale is changed every time.
(First embodiment)
FIG. 1 is a diagram showing a schematic configuration of a spray coating apparatus according to the first embodiment, and FIG. 2 is an enlarged sectional view showing a solvent supply nozzle provided in the spray coating apparatus of FIG.

  The spray coating apparatus according to the present embodiment includes a workpiece support 3 on which a workpiece 2 is placed in a coating chamber 1, and an application nozzle 5 that sprays a coating solution onto the workpiece 2 placed on the workpiece support 3. And a plurality of (two in the drawing) solvent supply nozzles 8 for spraying the solvent outside the spray spray area 6 of the coating liquid, and the sprayed mist solvent (solvent) in the coating chamber 1 A means (mist-like solvent discharging means) 11 for discharging the mist 9 out of the coating chamber 1 and a means for detecting the concentration of the solvent outside the spray spray area 7 of the coating liquid in the coating chamber 1 (solvent concentration detection) And a controller 14 as a means (solvent concentration control means) for controlling the concentration of the solvent outside the spray spray area 7 of the coating liquid in the coating chamber 1. It is of vignetting schematic configuration.

A rotating shaft 3a of a motor (not shown) is attached to the lower surface of the work support base 3. When the motor is driven, the work support base 3 is also rotationally driven by the rotary shaft 3a. Moreover, it is preferable that the workpiece support 3 is configured to be able to move and rotate with respect to the X axis and the Y axis in addition to the rotation in the horizontal direction. The workpiece support 3 may be provided with a heating means for heating the workpiece 2 placed on the workpiece support 3.
The workpiece 2 is placed on the upper surface of the workpiece support 3. The work support 3 can hold the work 2 by suction.
As the workpiece 2, a substrate such as a silicon substrate, a printed substrate, a plastic substrate, or a Cu substrate, or a substrate of this type having a concavo-convex surface or a three-dimensional shape is used.

  A coating nozzle 5 is disposed above the work support 3. The coating nozzle 5 is connected to a coating liquid supply pipe 5a to which a coating liquid 4 is supplied from a coating liquid supply source (not shown), and a valve for controlling the flow rate of the coating liquid is connected to the coating liquid supply pipe 5a. 5b is provided. When the coating liquid is sprayed from the coating nozzle 5 toward the workpiece support 3, a region where a mist of the coating liquid (coating liquid mist) 4 a is generated is a spray spray area 6 for the coating liquid ( The area inside the dashed-dotted line 6 in FIG. The coating liquid 4 varies depending on the workpiece 2 placed on the workpiece support 3 and the treatment applied to the workpiece 2, but includes a resist and a resist thinner (solvent). The resist includes a negative resist, a positive resist, and a solder. A resist or the like is used.

Solvent supply nozzles 8 and 8 are disposed on both sides of the coating nozzle 5. Each solvent supply nozzle 8 is connected to a solvent supply pipe 8a to which a solvent 9 is supplied from a solvent supply source (not shown), and each solvent supply pipe 8a is provided with a valve 8b for controlling the flow rate of the solvent. ing. When the solvent 9 is sprayed from these solvent supply nozzles 8, 8, the area where the spray of the mist-like solvent (solvent mist) 9 a is generated is 7 outside the spray spray area of the coating liquid (outside the one-dot chain line 6 in FIG. 1). Area).
The spray coating apparatus of this embodiment is provided with two sets of atomized solvent spraying means including a solvent supply nozzle 8, a solvent supply source (not shown), a solvent supply pipe 8a, and a valve 8b.

  As the solvent 9, a solvent of a coating solution is used. For example, xylene, ethyl lactate, 3methylmethoxypropionate (MMP), ethylethoxypropionate (EEP), acetone, n-butyl acetate (NBA), A solvent used as a resist thinner such as ethyl cellosolve acetate (ECA), propylene glycol monomethyl ether (PGME), propylene glycol monomethyl ether acetate (PGMEA) is used.

Each solvent supply nozzle 8 is composed of an ultrasonic atomizing nozzle as shown in FIG. 2 that does not affect the air flow in the spray spray area 6. A vibrator 8c is provided in the ultrasonic atomizing nozzle 8, and when the liquid solvent 9 is supplied to the ultrasonic atomizing nozzle 8 and the vibrator 8c is driven to oscillate ultrasonic waves, The solvent mist 9 a composed of the 9 particles 9 c is generated, and the solvent mist 9 a is sprayed from the discharge port of the nozzle 8.
As the vibrator 8c, a solid type vibrator, a bolted Langevin type vibrator, a piezoelectric polymer film, a piezoelectric ZnO thin film, or the like is used.
In the solvent supply nozzle 8 composed of an ultrasonic atomizing nozzle as shown in FIG. 2, the pressure of the liquid solvent 9 is lowered in order to reduce the spraying speed of the solvent mist 9a. The spray speed of the solvent mist 9a is about 0.2 m / second or less. If the spray speed of the solvent mist 9a is too fast, the air current in the spray spray area 6 is adversely affected and cannot be uniformly applied to the workpiece 2.

  The particle diameter of the solvent mist 9a sprayed from the solvent supply nozzle 8 is preferably 60 μm or less. If the particle size of the solvent mist 9a is larger than 60 μm, it becomes a crater when it hits the substrate (workpiece) and causes uneven coating.

  An exhaust pipe as a mist-like solvent discharge means 11 is disposed outside the spray spray area 7 below the work support 3, and an exhaust port of the exhaust pipe opens to the spray spray area outside 7. A valve (not shown) and a negative pressure source (not shown) for controlling the exhaust amount are provided in the exhaust pipe. The mist-like solvent discharge means 11 may also serve as an air supply function.

Further, a semiconductor type organic solvent sensor 13 is provided outside the spray spray area 7 of the coating liquid so that the concentration of the solvent outside the spray spray area 7 can be detected. Further, the organic solvent sensor 13 is connected to a controller 14 provided outside the coating chamber 1, and sends a detected value of the solvent concentration to the controller 14.
The controller 14 is connected to the valves 8b and 8b and the mist-like solvent discharge means 11, and when the detected value of the solvent concentration is outside the desired range, the valve 8b and 8b are controlled to control the solvent supply nozzle 8. 8 by controlling the spray amount of the solvent sprayed from 8 or by controlling the valve or negative pressure source provided in the exhaust pipe 11 to control the discharge amount of the mist-like solvent discharged from the exhaust pipe 11. It is possible to control the solvent concentration in the coating chamber 1 during spraying of the liquid or before and after spraying of the coating liquid so as to be a desired concentration.
Further, the controller 14 is connected to the valve 5b, and is configured to be able to adjust the amount of coating liquid sprayed from the coating nozzle 5 by controlling the valve 5b.

The concentration of the solvent outside the spray area 7 needs to be controlled within an appropriate range when each solvent is used. When the concentration of the solvent is low, the particles are dried before the particles are bonded, and pinholes are generated in the coating film. When the concentration of the solvent is too high, the coating film does not dry, and liquid dripping or cutting occurs in the unevenness.
The solvent concentration is appropriately changed depending on the shape of the work 2 and the thickness of the coating film formed on each part of the work 2.
Here, the preferable concentration of the solvent outside the spray spray area 7 may have different values before and after spraying the coating liquid and during spraying.

Next, a spray coating method for forming a coating film on the surface of a workpiece using the spray coating apparatus shown in FIGS. 1 and 2 will be described.
First, the work 2 is placed on the upper surface of the work support 3 in the coating chamber 1 and held on the work support 3 by suction.
Next, the work support 3 is rotated together with the work 2 by driving the motor and rotating the rotating shaft 3a.
Next, the solvent mist 9a is sprayed from the solvent supply nozzles 8 and 8 so that the concentration of the solvent outside the spray spray area 7 is within a range of 0 ppm to a maximum of 400 ppm so as to have an appropriate predetermined value. By filling the mist atmosphere, the solvent mist 9 a is supplied to the surface of the workpiece 2. The solvent concentration range 0 ppm to 400 ppm outside the spray spray area 7 is selected from the group consisting of ethyl lactate, propylene glycol monomethyl ether (PGME), and propylene glycol monomethyl ether acetate (PGMEA). One of the cases is that the same kind of solvent is used as the solvent contained in the coating liquid to be sprayed. Here, the predetermined value differs depending not only on the type of solvent but also on the shape of the workpiece, and so must be set individually in each case.

  Next, the solvent concentration of the solvent sprayed from the solvent supply nozzles 8, 8 outside the spray spray area 7 is detected by the organic sensor 13, and the solvent supply nozzle is detected by the controller 14 based on the detected value of the solvent concentration. By controlling the spray amount of the solvent sprayed from 8, 8 or controlling the discharge amount of the mist-like solvent discharged from the exhaust pipe 11, the solvent concentration outside the spray spray area 7 becomes a predetermined concentration. While being controlled, the mist-like coating liquid 4a is sprayed from the coating nozzle 5 onto the surface of the rotating workpiece 2 to form the coating film 15. Here, the coating film 15 formed on the workpiece 2 immediately after spraying the mist-like coating liquid 4a has irregularities 15a on the surface as shown in FIG.

Next, after stopping spray spraying of the mist-like coating liquid 4a from the coating nozzle 5, by spraying the solvent mist 9a from the solvent supply nozzles 8, 8, the inside of the coating chamber 1 is made a solvent mist atmosphere, As shown in FIG. 3B, when the solvent mist 9a is sprayed on the coating film 15 having unevenness formed on the surface of the workpiece 2, the unevenness 15a of the coating film 15 is flattened by the solvent mist 9a. The coating film 15 having a smooth surface as shown in FIG.
Next, the spraying of the solvent mist 9a from the solvent supply nozzles 8 and 8 is stopped, and the solvent mist 9a is forcibly exhausted through the exhaust pipe 11 to reduce the solvent concentration in the coating chamber 1, thereby drying the coating film 15. Is promoted, the workpiece 2 on which the coating film 15 having a uniform thickness is formed is obtained.

When forming a coating film on the surface of the workpiece using the spray coating apparatus shown in FIGS. 1 to 2, a mist-like solvent 9a is sprayed from the solvent supply nozzles 8 and 8 to evacuate the inside of the coating chamber 1. After adjusting to a certain target solvent concentration, spraying of the mist-like coating liquid 4a is started from the coating nozzle 5, and the mist-like solvent 9a is forcibly exhausted from the exhaust pipe 11 in the latter half of the coating. Thus, the drying speed of the coating film may be balanced.
In the spray coating apparatus of the above-described embodiment, the case where the solvent supply nozzle 8 is constituted by an ultrasonic atomizing nozzle has been described. However, even if the dropping nozzle does not affect the airflow in the spray area. Good.

(Second Embodiment)
FIG. 4 is a diagram illustrating a schematic configuration of a spray coating apparatus according to the second embodiment.
The spray coating apparatus of the second embodiment is different from the spray coating apparatus of the first embodiment shown in FIG. 1 in that a shutter 30 is provided in the upper part of the coating chamber 1 and a mist-like solvent. The configuration of the spray means is different.
The shutter 30 is moved in the horizontal direction (left and right in FIG. 4) to partition the coating chamber 1 into an upper solvent mist generating chamber 32 and a lower spray coating chamber 33, or to open the solvent mist generating chamber 32. It communicates with the spray coat chamber 33.
It should be noted that the shutter is not limited to one that moves horizontally, and is more preferably one that changes the aperture area by a diaphragm mechanism.

The mist-like solvent spraying means provided in the spray coating apparatus of this embodiment is disposed in the solvent storage tank 38 provided in the solvent mist generating chamber 32 in which the solvent 9 is stored, and the solvent storage tank 38. The vibrator 38c, a solvent supply pipe 8a connected to the solvent storage tank 38, a solvent supply source (not shown) for supplying the solvent 9 to the solvent supply pipe 8a, and a valve 8b provided in the solvent supply pipe 8a. Two sets of the mist-like solvent spraying means are provided. The solvent storage tanks 38 are disposed in the solvent mist generating chamber 32 so as to be above both sides (left and right) of the coating nozzle 5.
The mist-like solvent spraying means oscillates an ultrasonic wave by driving the vibrator 38c while supplying the solvent 9 from the solvent supply source to the solvent supply pipe 8a and storing the solvent 9 in the solvent storage tank 38. As a result, a solvent mist 9a is generated.
The region where the solvent mist 9a is generated from the solvent storage tanks 38, 38 with the shutter 30 opened and the flow of the solvent mist 9a occurs mainly outside the spray spray area 7 of the coating liquid (indicated by the one-dot chain line 6 in FIG. 4). Outer region).
Also in this embodiment, the controller 14 is connected to the valves 8b and 8b and the mist-like solvent discharging means 11.

Next, a spray coating method for forming a coating film on the surface of a workpiece using the spray coating apparatus shown in FIG. 4 will be described.
First, the work support 3 is rotated together with the work 2 in the same manner as in the first embodiment.
First, the shutter 30 is opened, and the solvent 9 is supplied from the solvent supply source to the solvent supply pipe 8a to store the solvent 9 in the solvent storage tank 38. Then, the vibrator 38c is driven to generate ultrasonic waves. The solvent mist 9a is generated by oscillating, and the solvent mist 9a is slowly moved toward the spray coat chamber 33 to supply the solvent mist 9a to the surface of the workpiece 2.

  Next, the concentration of the solvent moving from the solvent mist generating chamber 32 outside the spray spray area 7 is detected by the organic sensor 13, and the controller 14 detects the concentration from the solvent storage tanks 38, 38 based on the detected value of the solvent concentration. By controlling the amount of solvent mist to be generated or controlling the amount of solvent mist discharged from the exhaust pipe 11, the concentration of the solvent outside the spray spray area 7 is controlled so as to become a predetermined concentration. The mist-like coating liquid 4a is sprayed from the nozzle 5 onto the surface of the rotating workpiece 2 to form a coating film 15 having irregularities 15a on the surface as shown in FIG.

Next, after the spray of the mist-like coating liquid 4a from the coating nozzle 5 is stopped, a solvent mist 9a is generated from the solvent storage tanks 38, 38, and the inside of the spray coat chamber 33 is changed to a solvent mist atmosphere. 3B, when the solvent mist 9a is sprayed on the coating film 15 having irregularities formed on the surface of the workpiece 2, the coating film 15 having a smooth surface as shown in FIG.
Next, the shutter 30 is closed or the vibration of the vibrator 38 c and the supply of the solvent 9 to the solvent storage tank 38 are stopped so that the solvent mist 9 a does not move to the spray coat chamber 33. When the drying of the coating film 15 is promoted by forcibly exhausting the solvent mist 9a to reduce the solvent concentration in the spray coating chamber 33, the workpiece 2 on which the coating film 15 having a uniform thickness is formed is obtained.

(Third embodiment)
FIG. 5 is a diagram illustrating a schematic configuration of a spray coating apparatus according to the third embodiment.
The spray coating apparatus of the third embodiment is different from the spray coating apparatus of the first embodiment shown in FIG. 1 in that a shutter 30 is provided in the upper part in the coating chamber 1 and a mist-like solvent. The configuration of the spray means is different.
The shutter 30 is moved in the horizontal direction in the same manner as provided in the second embodiment, thereby dividing the coating chamber 1 into an upper solvent mist generating chamber 32 and a lower spray coating chamber 33, or a solvent mist generating chamber. 32 is opened to communicate with the spray coat chamber 33.

The mist-like solvent spraying means provided in the spray coating apparatus of this embodiment includes a solvent mist supply pipe 38a having one end opened in the solvent mist generating chamber 32, and a solvent mist 9a in the solvent mist supply pipe 38a. A solvent mist supply source (not shown) to be supplied and a valve 38b provided in the solvent mist supply pipe 38a, one end of the solvent mist supply pipe 38a is connected to one side of the coating nozzle 5 ( It is arranged in the solvent mist generating chamber 32 so as to be above the right side in the drawing.
When the solvent mist 9a is supplied from the solvent mist supply source to the solvent mist supply pipe 38a, the mist-like solvent spray means supplies the solvent mist 9a into the solvent mist generating chamber 32 from one end of the supply pipe 38a. It has become.
When the solvent mist 9a is supplied into the solvent mist generating chamber 32 with the shutter 30 opened, the solvent mist 9a moves to flow toward the spray coat chamber 33. Here, the region where the flow of the solvent mist 9a occurs is mainly outside the spray spray area 7 of the coating liquid (the region outside the one-dot chain line 6 in FIG. 6).
Also in this embodiment, the controller 14 is connected to the valve 38b and the mist-like solvent discharging means 11.

Next, a spray coating method for forming a coating film on the surface of a workpiece using the spray coating apparatus shown in FIG. 5 will be described.
First, the work support 3 is rotated together with the work 2 in the same manner as in the first embodiment.
First, the shutter 30 is opened, the solvent mist 9a is supplied from the solvent mist supply source to the solvent mist supply pipe 38a, and the solvent mist 9a is supplied from one end of the supply pipe 38a to the solvent mist generating chamber 22. The solvent mist 9a is slowly moved toward the spray coating chamber 33, and the solvent mist 9a is supplied to the surface of the workpiece 2.

  Next, the concentration of the solvent moving from the solvent mist generating chamber 32 outside the spray spray area 7 is detected by the organic sensor 13 and supplied from the solvent mist supply pipe 38a by the controller 14 based on the detected value of the solvent concentration. The nozzle for application while controlling the concentration of the solvent outside the spray area 7 to be a predetermined concentration by controlling the amount of solvent mist to be discharged or controlling the amount of solvent mist discharged from the exhaust pipe 11 The mist-like coating liquid 4a is sprayed from 5 onto the surface of the rotating work 2 to form a coating film 15 having irregularities 15a on the surface as shown in FIG.

Next, after the spraying of the mist-like coating liquid 4a from the coating nozzle 5 is stopped, the solvent mist 9a is supplied from the solvent mist supply pipe 38a to the solvent mist generating chamber 32, and this solvent mist 9a is supplied to the spray coating chamber 33. When the inside of the spray coat chamber 33 is moved to a solvent mist atmosphere to disperse the solvent mist 9a on the coating film 15 having irregularities formed on the surface of the workpiece 2 as shown in FIG. The coating film 15 having a smooth surface as shown in FIG.
Next, the shutter 30 is closed or the supply of the solvent mist 9a to the solvent mist supply pipe 38a is stopped so that the solvent mist 9a does not move to the spray coat chamber 33, and the exhaust pipe 11 removes the solvent mist 9a. When drying of the coating film 15 is promoted by applying forced evacuation to reduce the solvent concentration in the spray coating chamber 33, the workpiece 2 having the coating film 15 having a uniform thickness is obtained.

The spray coating method of the above embodiment can also be applied to a method for manufacturing a three-dimensional circuit board. In that case, a coating liquid composed of a resist and its solvent is used as the coating liquid 4 and is mounted on the work support 3. As the work 2 to be placed, a work having irregularities and slopes on the surface is used.
Further, in this method of manufacturing a three-dimensional circuit board, a three-dimensional circuit board is obtained by including a step of forming a circuit pattern by a photolithography technique after the step of forming a coating film on the surface of the workpiece.

The figure which shows schematic structure of the spray coat apparatus of the 1st Embodiment of this invention. FIG. 2 is an enlarged cross-sectional view illustrating a solvent supply nozzle provided in the spray coating apparatus of FIG. 1. The figure which shows the spray-coating method of embodiment of this invention in order of a process. The figure which shows schematic structure of the spray coat apparatus of the 2nd Embodiment of this invention. The figure which shows schematic structure of the spray coat apparatus of the 3rd Embodiment of this invention. The schematic block diagram which shows the other example of the conventional coating device.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Coating chamber, 2 ... Work, 3 ... Work support stand, 4 ... Coating liquid, 4a ... Spray-like coating liquid (coating liquid mist), 5 ... Coating nozzle 5a ... coating solution supply pipe, 5b ... valve, 6 ... spray spray area of coating solution, 7 ... outside spray spray area of coating solution, 8 ... nozzle for solvent supply, 8c .. Vibrator, 9 ... Liquid solvent, 9a ... Atomized solvent (solvent mist), 9c ... Solvent particles, 11 ... Exhaust pipe (mist-like solvent discharging means), 13 ... Organic solvent sensor (solvent concentration detection means), 14 ... Controller (solvent concentration control means), 15 ... Coating film, 15a ... Unevenness, 30 ... Shutter, 32 ... Solvent mist Generation chamber, 33 ... spray coat chamber, 38 ... solvent reservoir, 38a ... solvent mist supply pipe 38b ··· valve, 38c ··· vibrator

Claims (9)

A spray coating apparatus that has a workpiece support in the coating chamber and sprays a coating liquid onto the workpiece placed on the workpiece support to form a coating film on the surface of the workpiece,
A coating nozzle for spraying the coating liquid onto the workpiece and a solvent supply nozzle for spraying a solvent of the coating liquid outside the spray spray area of the coating liquid are provided in the coating chamber,
The spray further comprises means for discharging the sprayed mist solvent out of the coating chamber and means for controlling the concentration of the solvent outside the spray spray area in the coating chamber. Coat equipment.   The spray coating apparatus according to claim 1, wherein the solvent sprayed from the solvent supply nozzle is the same type as the solvent contained in the coating liquid sprayed from the coating nozzle.   The spray coating apparatus according to claim 1, wherein the solvent supply nozzle is an ultrasonic atomizing nozzle or a dropping nozzle that does not affect an air flow in the spray spray area.   4. The spray coating apparatus according to claim 1, wherein the solvent mist sprayed from the solvent supply nozzle has a particle size of 60 μm or less. 5.   The spray coating apparatus according to any one of claims 1 to 4, wherein the coating is applied from the coating nozzle while controlling a concentration of the solvent sprayed from the solvent supply nozzle outside the spray spraying area. A spray coating method comprising a step of spraying a liquid to form a coating film on the surface of the work placed on the work support.   6. The spray coat according to claim 5, further comprising a step of spraying the solvent from the solvent supply nozzle and supplying the spray to the surface of the workpiece before the step of forming a coating film on the surface of the workpiece. Method.   The step of spraying the solvent onto the surface of the work from the nozzle for supplying the solvent after the step of forming a paint film on the surface of the work is provided with a step of smoothing the surface of the paint film. The spray coating method according to 5 or 6. A method of manufacturing a three-dimensional circuit board using the spray coating method according to any one of claims 5 to 7,
A method for producing a three-dimensional circuit board, wherein a coating liquid comprising a resist and a solvent thereof is used as the coating liquid, and a work having irregularities on the surface is used as the work placed on the work support.   The method for manufacturing a three-dimensional circuit board according to claim 8, further comprising a step of forming a circuit pattern by a photolithography technique after the step of forming a coating film on the surface of the workpiece.

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