JP2002329951A - Mounting substrate coating equipment and coating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide mounting substrate coating equipment or a coating method which are suitable for using silicon liquid as coating agent which has intrinsic physical properties such as compressibility and gas absorption. SOLUTION: The mounting substrate coating equipment is provided with a coating liquid tank, a jetting part and a liquid sending means. The jetting part is equipped with an on-off valve, and the jetting of coating liquid against a surface of the mounting substrate is controlled by an on/off operation of the valve. The liquid sending means constitutes a liquid sending system in which a free drop liquid sending using a height difference and an open system pressurized liquid sending interlocked with the coating liquid jetting by opening the valve in the jetting part are combined.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and a method for coating a mounting substrate with a coating solution for moisture-proof insulation. More particularly, the present invention relates to a mounting substrate coating apparatus and a coating method suitable for using a silicon liquid as the coating liquid.

[0002]

2. Description of the Related Art A mounting board on which a semiconductor, various electronic parts or connectors are mounted has been conventionally coated with a moisture-proof insulating agent in order to protect the various parts from moisture, electric leakage and the like. As such, urethane resins are widely used. However, in recent years, heat resistance has been required of the mounting substrate, and there is a problem that urethane resin cannot sufficiently meet such a requirement. Furthermore, when using a solvent-based resin, it is necessary to pay close attention to its use and disposal because of its adverse effects on the human body and the environment.

[0003] By the way, on the mounting board, there are parts which must be subjected to the above-mentioned moisture proof and insulating treatment, but on the other hand, parts such as radiation fins and connectors which must not be subjected to the moisture proof and insulating treatment are mounted. Coating with an insulating material must be performed selectively avoiding these components. Examples of the coating method include spray coating, brush coating, and coating with a single nozzle. However, spray coating is not suitable for selective coating of mounted components because the moisture-proof insulating agent is easily scattered. The coating by this nozzle is excellent in selectivity, but has a drawback that it is inefficient and unsuitable for mass processing. Therefore, recently, a flat pattern nozzle (Japanese Patent Application Laid-Open No. 62-154794) has been used to draw a locus of movement of the nozzle by a robot.

[0004]

As a resin having higher heat resistance than urethane resin, silicon can be cited. In addition, since silicon is a solventless resin, it has the advantages of being environmentally friendly, safe and sanitary. However, the coating of the mounting substrate using the silicon liquid has a possibility that (1) due to the compressibility of silicon, when the liquid is sent under pressure, the liquid may be rapidly expanded at the discharge port and scattered.
(2) Due to the gas absorbency of silicon, it is easy to embrace the gas inside, especially under negative pressure. (3) Silicon for substrate coating contains a large amount of insoluble additives, so damage to the mechanism of the device such as wear may occur. (4) Since silicon is a moisture-curing reactive resin, there are various problems based on the inherent properties of silicon that a film (slag) is formed on the liquid surface in the presence of moisture. For this reason, conventionally, it has been difficult to automate or mass-process the coating, particularly using a silicon liquid.

Therefore, a first object of the present invention is to provide a coating apparatus or a coating method which can solve the above-mentioned problems caused by the physical properties inherent to silicon and can use silicon as a coating agent. In other words, a first object of the present invention is to consider a physical property of silicon, and a coating apparatus suitable for the physical property of the silicon.
As well as providing a coating method.

A second object of the present invention is to provide a coating apparatus and a coating method for coating a substrate with high productivity and efficiency in a coating apparatus and a coating method for a mounting substrate suitable for silicon. is there.

[0007]

The present inventors have made various studies to solve the above-mentioned problems, and as a means for sending a silicon liquid, a liquid sending method using gravity (free fall using a height difference). Combination of the liquid supply and the pressurized liquid supply under the open state enables the silicon liquid to be supplied to the discharge port with a reduced pressure load, thereby causing inconvenient discharge and gas due to the compressibility of the silicon liquid. It was found that the phenomenon of gas entrapment due to absorptivity could be eliminated, and it was confirmed that the mounting substrate coating using a silicon liquid as a coating agent could be automated. In addition, by sending the coating liquid using a continuous tank provided with a partition plate with a specific structure, impurities can be easily removed from the silicon liquid, reliability of the coating device can be ensured, and the coating can be dried under dry conditions. Alternatively, it has been found that the formation of a liquid surface at the time of coating can be avoided by performing the process under a nitrogen gas replacement condition.

Further, based on such knowledge, the present inventors have studied for the purpose of developing a coating method and an apparatus having high productivity, which is a second object.
As a coating method, dipping method on the back of the mounting board,
In addition, a nozzle discharge method that can selectively apply to the component is adopted for the surface that is the component mounting surface, and the coating process can be performed quickly by performing this process simultaneously. In addition, the selective application method using multiple nozzles enables high efficiency. It has been found that efficiency and mass production are possible.

The present invention has been developed based on these findings. That is, the present invention provides the following items 1 to 11
Item 1 is a coating apparatus for a mounting substrate that can use a silicon liquid as a coating liquid. A mounting having a coating liquid tank for dip-coating the coating liquid on the back surface of the mounting substrate, a discharge unit for discharging and applying the coating liquid on the surface of the mounting substrate, and a liquid sending unit for sending the coating liquid from the coating liquid tank to the discharge unit. A substrate coating apparatus, wherein the discharge unit is provided with an on-off valve, and the discharge of the coating liquid is controlled by opening and closing the valve. A mounting substrate coating apparatus characterized by comprising a liquid supply system combining an open system pressure liquid supply interlocked with a coating liquid discharge by opening and closing an opening / closing valve of a part. Item 2. The discharge unit is disposed above the coating liquid tank, and the mounting substrate is disposed between the discharge unit and the coating liquid tank and coating is performed at this position, so that the coating liquid can be circulated and sent. Item 4. The mounting substrate coating apparatus according to Item 1. Item 3. An item configured to simultaneously perform front surface coating by discharging the coating liquid from the discharge part and back surface coating by immersion in the coating liquid tank with respect to the mounting substrate disposed between the discharge part and the coating liquid tank. 3. The mounting substrate coating apparatus according to 1 or 2. Item 4. The discharge unit includes a plurality of discharge nozzles, and each discharge nozzle is controlled so as to selectively discharge and apply a coating liquid in accordance with a position of a component mounted on a mounting board surface. Item 4. The mounting substrate coating apparatus according to any one of Items 1 to 3. Item 5. The coating liquid tank is composed of at least three successive low-water tanks including a mounting substrate immersion tank. It is partitioned by a weir so that it falls into the downstream tank, and the most downstream tank and the most downstream front tank are separated by a partition plate whose lower part is opened. Item 5. The mounting substrate according to any one of Items 1 to 4, wherein the mounting substrate is configured to flow into the tank, and further provided with an outlet in the most downstream tank so that the water level of the continuous tank is gradually lowered. Coating equipment. Item 6. Further, it has a mounting substrate transport means and a vertical driving means, and the mounting substrate is moved to the coating position between the discharge portion and the mounting substrate immersion tank of the coating liquid tank by the mounting substrate transport means, and the coating liquid is moved by the vertical driving means. Item 1 to Item 5 wherein, by raising the bath, the back surface of the mounting substrate arranged at the coating position is immersed in the coating liquid of the mounting substrate immersion bath to apply the back surface of the mounting substrate. A mounting substrate coating apparatus according to any one of the above. Item 7. After immersion coating of the back surface of the mounting substrate, the mounting substrate is horizontally moved in the traveling direction by the mounting substrate transfer means while the back surface is immersed in the coating liquid of the mounting substrate immersion tank, and then the coating liquid tank is lowered by the vertical driving means. Item 7. The mounting substrate coating apparatus according to Item 6, wherein the back surface is detached from the coating liquid, and the mounting substrate is horizontally moved in the advancing direction by the mounting substrate transport means to arrange the next mounting substrate at the coating position. . Item 8. Item 8. The mounting substrate coating apparatus according to any one of Items 1 to 7, further comprising a unit for removing an excess coating solution from the coated mounting substrate. Item 9. Items 1 to 8 wherein the coating step is performed under dry conditions or nitrogen gas replacement conditions.
The mounting substrate coating apparatus according to any one of the above. Item 10. Item 10. The mounting substrate coating apparatus according to any one of Items 1 to 9, wherein the mounting substrate coating apparatus includes a curing reaction section in addition to the coating process section, wherein the setting is such that the curing reaction is performed under high humidity. Item 11. Item 11. The mounting substrate coating apparatus according to any one of Items 1 to 10, wherein a silicon liquid is used as the coating liquid.

The mounting substrate coating apparatus of the present invention is an apparatus suitable for using a silicon liquid as a coating liquid. However, the coating liquid is not particularly limited to this, and the coating liquid may be formed of a urethane resin or the like. A wide variety of moisture-proof insulating agents used for coating a substrate can be used.

Further, the present invention is a method for coating a mounting substrate described in the following items 12 to 17. In addition, the coating method can be paraphrased as a method of manufacturing a mounting substrate coated with a coating liquid. Item 12. Item 12. A method for coating a mounting substrate, comprising a step of coating the mounting substrate with a coating liquid using the apparatus according to any one of the above items 1 to 11. Item 13. A method for coating a mounting substrate, comprising a step of discharging and applying a coating liquid onto a mounting substrate surface using a nozzle, wherein the coating liquid is supplied to a nozzle discharge port by free-fall liquid feeding using gravity and open system pressure feeding. A method for coating a mounting substrate, wherein the method is performed in combination with a liquid. Item 14. A method for coating a mounting substrate, comprising a step of dipping the back surface of the mounting substrate in a coating liquid tank and a step of discharging and applying the surface of the mounting substrate with a coating liquid, wherein the surface application of the mounting substrate is selectively performed using a plurality of nozzles. Item 14. The method for coating a mounting substrate according to Item 13, wherein the method is performed by coating. Item 15. The first step of immersing the back surface of the mounting substrate in the coating liquid in the coating liquid tank and simultaneously coating the surface of the mounting substrate selectively using the discharge unit, the back surface of the mounting substrate was immersed in the coating liquid of the immersion tank. The method for coating a mounting substrate according to claim 13, further comprising a second step of horizontally moving the mounting substrate in the moving direction in the state, and a third step of detaching the mounting substrate from the coating liquid in the immersion tank. Item 16. The coating liquid is applied to the mounting substrate under a dry condition or a nitrogen gas replacement condition, and then the coated liquid is cured by placing the coated mounting substrate under a high humidity condition. The method for coating a mounting board according to any one of the above. Item 17. Item 17. The method for coating a mounting substrate according to any one of Items 12 to 16, wherein a silicon liquid is used as the coating liquid.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, the back surface of a mounting substrate is coated by a dipping method, and the surface on which various components are mounted is coated by a nozzle discharge method so as to be selectively coated.

[0013] The mounting substrate coating apparatus of the present invention is characterized in that it is suitable for using a silicon liquid as a coating agent. That is, the apparatus of the present invention is a mounting substrate coating apparatus including a liquid sending unit and a discharge unit suitable for the physical properties of the silicon liquid.

[0014] In the following description, the coating liquid may be referred to as a silicon liquid.

[0015] Specifically, the liquid sending means is gravity (difference in height)
Is used in combination with free-flow liquid sending using an open system and pressurized liquid sending with an open system, whereby the coating liquid is adjusted so that a pressure load of a certain level or more is not applied to the coating liquid. With such a configuration, in the apparatus of the present invention, it is possible to avoid inconveniences due to inherent physical properties such as compressibility and gas absorbency of the silicon liquid. Here, the open system pressurized liquid supply is a liquid supply method in which the pressure is applied in a state where the discharge port (discharge port) of the liquid supply path is opened and the liquid is supplied in the direction of the discharge port. Is used as a means for sending the liquid to the discharge port. In this case, an opening / closing valve is provided in the discharge unit, and the opening and closing of the valve controls the discharge of the coating liquid onto the mounting substrate surface,
The above-described pressurized liquid sending is performed in conjunction with the discharge by opening the on-off valve.

The coating apparatus of the present invention comprises: a coating liquid tank for dip-coating a coating liquid on the back surface of a mounting board; a discharge section for discharging and coating the coating liquid on the surface of the mounting board; and a discharging section from the coating liquid tank. A coating liquid having a liquid feeding means for feeding a coating liquid to the mounting substrate, wherein the coating liquid flowing out of the coating liquid tank is preferably supplied to a discharge portion through the liquid feeding means, and then discharged to the mounting substrate from the discharge portion. This is a device having a so-called circulating liquid feeding system in which the coating liquid is sent while being circulated by re-supplying the remaining coating liquid to the coating liquid tank again.

Such a circulating liquid feeding system is shown in FIGS. It is to be noted that this figure is an example of a specific embodiment showing the concept of the liquid feeding system of the present invention, and the present invention is not limited to such a specific embodiment.

Here, a coating liquid tank (1), a discharge section (2), and a liquid supply means (3) for supplying the coating liquid from the coating liquid tank to the discharge section are provided. A tank (31) arranged at a lower position than the coating liquid tank (1), a tube (32) for feeding the coating liquid from the coating liquid tank (1) to the tank (31), and a lower part of the tank (31). Pump (3)
4) a tube (35) for feeding the coating liquid from the pump (34) to the discharge section. The discharge part (2) is disposed above the coating liquid tank (1), and the coating position (coating position) where the mounting substrate A is disposed between the discharge part (2) and the coating liquid tank (1) to perform coating. 41) is provided. With such a circulating liquid feeding system, the coating liquid first flows into the tank (31) through the tube (32) by the free fall liquid feeding using a height difference from the coating liquid tank (1). Pumped to the pump (34) through the lower conduit (33), and then to the pump (34)
Is sent to the discharge section (2) through the tube (35) by the pressurized liquid sending. And when coating
The coating liquid sent to the discharge section (2) is dropped and discharged onto the surface of the mounting substrate A disposed below the coating liquid. As a result, excess coating liquid not used for coating flows again into the coating liquid tank (1),
The liquid is again sent to the discharge section (2) via the liquid sending means (3).

Here, as the method for feeding the coating liquid from the inside of the pump (34) to the discharge section (2), the above-described open-type pressurized liquid feeding is adopted. Specifically, at the same time as opening and closing the on-off valve (21) provided in the discharge part (2) to discharge-coat the coating liquid on the mounting substrate surface,
The pump (34) operates to feed the coating liquid under pressure. In FIGS. 1 and 2, a piston pump is exemplified as the pump (34), but there is no particular limitation as long as it is a pressurizing unit that can feed the coating liquid to the discharge unit by pressurization.
As described above, since the coating liquid is pressurized in conjunction with the opening of the discharge unit (2), the coating liquid is adjusted so as not to apply a pressure load exceeding a certain level. When a silicon liquid is used as the coating liquid, the pressure that can be applied to the silicon liquid is 0.2 MPa or less, and preferably 0.1 MPa or less.

The discharge part (2) discharges the coating liquid supplied through the tube (35) to the surface of the mounting substrate A disposed below the part, and has a function of coating the substrate surface with the coating liquid. For example, as shown in FIGS. 1 and 2, a discharge nozzle (22) having an on-off valve (21) in communication with the tube (35) can be used.

The number of discharge nozzles may be one, but it is preferable to provide two or more discharge nozzles from the viewpoint of the efficiency of the coating operation. In this case, the distal end of the tube (35) branches into a plurality of tubes according to the number of discharge nozzles, and the distal end of the branch tube (23) is connected to the discharge nozzle (22). The branch tube (23) or the discharge nozzle (22) is provided with an on-off valve (21) for each tube or nozzle. The coating liquid supplied to the discharge section (2) is supplied to a discharge nozzle (22)
Is discharged onto the mounting board A arranged at the lower part through
Thus, the surface of the substrate on which various components are mounted is coated. The position of the discharge nozzle (22) or its operation is
It is preferable to control and manage with a computer or the like so that the target part is selectively coated while avoiding the part which should not be coated according to the component mounting surface of the mounting board, and the coating is completed in a short time. . That is, the discharge section (2) preferably has a function of selectively and efficiently silicon-coating the surface of the mounting board in accordance with the mounted components and their positions, in addition to the above functions.

In this way, the surface of the mounting substrate A is coated by discharging the coating liquid from the discharging part (2). The coating liquid discharged extra here is disposed below the mounting substrate A. It can be received in the coating liquid tank (1). Also the coating position (4
By providing 1) above the coating liquid tank (1) and arranging the mounting substrate A at this position, dip coating on the back surface of the mounting substrate A can also be performed. Here, the dip coating of the coating liquid on the back surface of the mounting substrate is performed by a vertical driving means (5) provided below the coating liquid tank (1).
By raising the coating liquid tank (1). At this time, the coating liquid tank (1) is set so that the back surface of the mounting substrate A is immersed in the coating liquid, specifically, until the surface of the substrate and the liquid level of the coating liquid substantially match (stroke in FIG. 1). S) Raise. By performing such backside dip coating and the above-described surface discharge coating simultaneously, a more efficient coating process can be performed.

In the circulating liquid feeding system, it is preferable that the volume of the circulating coating liquid is always kept constant. The adjustment of the volume is not limited, but can be performed, for example, by controlling and managing such that a constant amount of the coating liquid is always stored in the tank (31). Specifically, the control system automatically supplies the coating liquid from the coating liquid supply unit (38) when the coating liquid in the tank falls below a predetermined lower limit (for example, about 1/3 of the tank internal capacity). A method of supplying the coating liquid into the tank through the port (36) can be exemplified.

The coating apparatus of the present invention basically needs to have a liquid feeding system including the above-mentioned coating liquid tank (1), discharge section (2), and liquid sending means (3). However, when a silicon liquid is used as the coating liquid, since impurities and a film component (solid content) formed by surface hardening are mixed therein, a coating liquid purifying means is provided in addition to the above configuration. Is preferred.

The means for purifying the coating liquid, particularly the silicon liquid, will be described with reference to FIG.

In order to purify the coating liquid, as shown in FIG. 3, the coating liquid tank (1) includes at least a mounting substrate immersion tank (11) configured to gradually lower the water level.
It can be implemented by using a continuous tank. In the continuous tank, first, an immersion tank (11) and a second tank (next downstream tank) (12) located downstream of the immersion tank (11) are separated by a weir (14) having a predetermined height. The second tank beyond the weir (14)
It is configured to fall into (12). As a result, a coating (slag) formed on the liquid surface by the curing reaction also flows out to the second tank (12). And the most downstream tank of the continuous tank (Fig. 3
In the third tank (13), an outlet (15) is provided so that the water level in the continuous tank becomes lower in order. And the most downstream tank
(13) and its front tank (the most downstream tank, the second tank in FIG. 3) are separated by a partition plate (16) having an opening at the lower part. The suspended matter (17) such as slag is blocked, and the purified coating liquid is configured to flow into the most downstream tank (13) through the lower opening. And the purification | coating coating liquid which flowed into the said most downstream tank flows into the tank (31) from the outlet (15) through the tube (32) (FIGS. 1, 2). Since the purifying means is carried out by using a liquid supply using a difference in water level (free-fall liquid supply), it is suitable as a liquid supply method of the silicon liquid, and is incorporated in a part of the above-mentioned circulation liquid supply system. It can be carried out. Specifically, the substrate surface discharge coating is applied to the immersion tank (11) of the coating liquid tank.
The excess of the coating liquid falls into the immersion tank (11) by flowing in the upper part of the immersion tank (11). The third tank (13) which flows into the tank (12) and has a lower water level from the two tanks
When moving to the second tank, impurities such as slag are separated and removed by a partition plate (16) installed between the second tank and the third tank, and the coating liquid thus purified is discharged to the outlet ( 15)
The liquid flows out of the coating liquid tank (1) through the liquid supply unit (3), and is sent to the discharge unit (2) via the above-described liquid sending unit (3).

Further, when immersing the back surface of the mounting substrate in the coating liquid of the immersion tank (11), the gas is easily chewed, and if left as it is, a film is formed with air bubbles contained therein. In order to eliminate this inconvenience and to prepare a mounting board of stable quality, it is necessary to remove air bubbles mixed in the back surface of the substrate or to remove unpainted portions caused by air bubbles (hereinafter, such means are collectively referred to as an air bubble removing method). Is preferably provided.

The means for removing such bubbles will be described with reference to FIG.

The removal of air bubbles or the elimination of the uncoated portion can be carried out by combining the dip coating of the back surface of the mounting substrate and the transport of the mounting substrate. As described above, the back surface of the mounting substrate is applied by moving the immersion tank (11) by the vertical driving means (5).
It is performed by raising until the coating liquid is immersed on the back surface of the mounting board (stroke S in the figure).
At this time, by moving the mounting board in the advancing direction (right direction in the figure) with a certain distance (distance a in the figure) while immersed in the liquid, the coating liquid can be brought into contact with the coating liquid due to the presence of bubbles mixed on the back side. The coating liquid can be contact-applied to a portion that did not exist. The moving distance a is not particularly limited, but may be about 80% of the longitudinal dimension of the substrate. The moving speed at this time is not particularly limited, but if it is too fast, the liquid surface rises on the front surface in the traveling direction, and the liquid adheres to the mounted parts to be prevented from being coated. . When the immersion movement of the substrate is completed, the coating liquid tank (1) including the immersion tank is lowered to the original position by the vertical drive means (5), and then the mounting substrate is horizontally moved in the movement direction for a fixed distance (distance b in the figure). I do. This movement can be performed at a high speed in order to shorten the coating process. When the immersion movement and the high-speed movement have been completed, the mounting substrate is at a distance (a + b).
As a result, the movement of one substrate is completed, and the processing substrate to be coated next is arranged at the coating position (41).

In FIG. 3, the coating liquid tank (1)
Is mounted on the gantry (54) and moved up and down by a vertical drive means (5) provided below the gantry (54). At this time, the stand (54)
Vertical bearings (52) guided by slide bearings (51) (Fig. 1) at two places on both sides of the gantry to move up and down each time
It is preferable to provide, for example, a vertical drive source (53) at the center. In addition, as the vertical drive source, an air cylinder and a servomotor with a speed reducer can be exemplified.

Further, it is preferable that the coating apparatus of the present invention is provided with a means for removing excess coating liquid applied to the front and back surfaces of the mounting substrate after coating. As a result, the coating thickness of the substrate can be made uniform. For example, as such means, there is a method of blowing off excess coating liquid from the substrate surface by air. When a silicon liquid is used as the coating liquid, dry air is adopted in consideration of the moisture curability of the silicon liquid. More specifically, as shown in FIG. 3, the coated mounting substrate A ′ transported in the traveling direction by one substrate feed (a + b) from the coating position.
A dry air blowing device (61) such as an air knife is installed above and below the tip of the mounting part (42), and the dry air is blown from the top and bottom at high speed to the front and back surfaces of the board, so that the excess coating liquid adhering to the front and back surfaces of the mounting board is Can be removed. By providing the substrate disposing portion (42) above the coating liquid tank, such removal can be performed on the coating liquid tank, whereby excess coating liquid can be dropped and collected in the coating liquid tank. Can be.

The mounting substrate coating apparatus of the present invention may be provided with at least the above-mentioned "coating process section". Another component is a "curing reaction" for curing the applied coating liquid to form a film. Department "
And, if necessary, a mounting substrate supply unit for supplying a mounting substrate to be coated to the coating process unit, and / or a mounting substrate storage unit for storing the coated mounting substrate. it can. FIG. 4 shows an example of a mounting substrate coating apparatus provided with such components.

In FIG. 4, the mounting board coating apparatus is roughly divided into a coating section (7) and a post-processing section (8), and the coating section (7) is provided with a mounting board supply section (71) and the mounting section. The coating process section (7) coats the mounting board sequentially supplied and transported from the board supply section.
The post-processing section (8) includes a curing reaction section (81) for curing the coating liquid on the substrate application surface coated in the coating processing section to form a film, and a mounting board for storing the coated mounting board. A storage section (82) is provided. Further, the mounting substrate coating apparatus further includes a mounting substrate transporting unit, which can transport the mounting substrate from the coating unit (7) to the post-process unit (8).

For supplying or storing the mounting substrate, a magazine rack system widely used in the art can be used. To supply and transport the mounting board A from the mounting board storage section (71) to the coating process section (72), first, the boards are pulled out one by one from the magazine rack (73), and the drawn-out boards are transferred to the transfer chain (43). An example is a method of transporting in the traveling direction by the attached chuck (44) (from left to right in FIG. 1).

In the coating section (72), coating of the mounting substrate is performed by nozzle discharge on the surface of the substrate on which various components are mounted, and by immersion on the back surface of the substrate. When a silicon liquid is used as the coating liquid, the silicon liquid is a moisture-curing reactive resin, so that when exposed to moisture, the liquid surface is hardened and covered with slag, which makes coating difficult. In order to solve this, the coating process section (72), preferably the entire coating section (7) may be covered with a cover (74), and the inside thereof may be made under dry conditions or nitrogen-substituted gas conditions. When the former drying condition is adopted, it is preferable to adjust the humidity so as to be 5% or less.

When the coating is completed, the mounting substrate A 'is transported to the curing reaction section (81). When a silicon liquid is used as the coating liquid, since the silicon is a moisture-curing reactive resin as described above, the curing reaction section (8
1) Preferably, the entire post-process section (8) is covered with a cover (84), and the inside is desirably subjected to high humidity conditions, whereby the curing can be carried out quickly. Humidifiers can be used to achieve high humidity. In FIG. 4, a humidifier (85) is installed below the conveyed mounting substrate A '. In this case, it is preferable to provide a steam outlet (86) so that steam can be sprayed from the humidifier to the back and side surfaces of the substrate. Next, the substrates A 'are transported to the mounting substrate storage section (82), and can be stored one by one in a magazine rack (83) provided in the storage section.

The coating section (7) and the post-process section (8) are mounted on a common substrate (9), so that the apparatus can be easily transported or moved as a single unit. Machine accuracy during use can be maintained.

The apparatus for coating a mounting substrate of the present invention and a method for coating a mounting board using the apparatus will be described with reference to FIGS.

The mounting boards A stored in the mounting board storage section (71) are pulled out one by one from the magazine rack (73) of the mounting board storage section (71), and the chucks attached to the transport chain (43) are pulled out. By (44), it is supplied and conveyed to the coating process part (72) (FIG. 1). The mounting board A transported to the coating process section (72) has a coating position above the immersion tank (11).
The coating liquid is applied to the front and back surfaces of the substrate at this position.

Specifically, the mounting substrate is positioned at the coating position.
As soon as it is located at (41) and stops, the piston pump (34)
Is activated, and the opening and closing valve (21) of the discharge section (2) is opened to pressurize and send the coating liquid to the discharge section (2), and the coating liquid is discharged from the discharge nozzle (22) to the coating position (41).
Is discharged onto the surface of the mounting substrate A that has been waiting for the first time. Furthermore, at the same time, the vertical drive source (air cylinder) (53)
The immersion tank (1) installed on the gantry (54) by
The coating liquid layer (1) containing (1) slowly rises toward the standby position of the mounting substrate. As a result, the back surface of the mounting substrate is immersed in the coating liquid in the immersion tank. At this time, the immersion tank (11) preferably rises with a rising stroke S such that the surface of the substrate and the liquid level of the coating liquid substantially coincide with each other, and specifically, a range of 40 to 100 mm can be selected. . The coating apparatus of the present invention is provided with a circulation liquid sending system for circulating the coating liquid between the immersion tank (11) and the discharge section (2), and the immersion tank (11) is provided with a weir (14). Since the coating liquid, which has been increased due to the falling inflow from the discharge section (2), flows out to the next downstream tank (12), the liquid level of the immersion tank is always kept constant, whereby the rising stroke S is also kept constant. Can be maintained.

When the rising stroke S is reached, the discharge application on the substrate surface is also completed.

Next, immediately after the mounting substrate is placed in the dipping tank (1
While immersed in 1), it horizontally moves in the traveling direction at a low speed (movement distance a). By the immersion movement of the substrate, the remaining coating due to the air bubbles entrapped on the rear surface is eliminated, and the coating liquid can be uniformly applied to the entire rear surface.

As soon as the immersion movement of the substrate is completed, the vertical drive source (53) is driven to descend, and the immersion tank (11) descends to its original position (downstroke S). Next, the substrate A ′ to which the coating liquid has been applied horizontally moves at a high speed in the traveling direction (movement distance b). By this movement, the mounting substrate A to be coated next is arranged at the coating position (41). That is, the substrate is transported in the traveling direction by one substrate feed by the immersion movement and the high-speed movement (a + b). Although not particularly limited, the production efficiency for one substrate is preferably 3 substrates / minute for A4 size.

Next, the substrate A ′ to which the coating liquid has been applied is transferred to the mounting substrate placement portion (4
Dry air blowing device (61) provided above and below the tip of 2)
As a result, dry air is blown onto the front and back surfaces at a high speed, whereby excess coating liquid is removed, and the coating thickness can be made uniform. In addition, it is preferable to perform the above-mentioned coating process under dry conditions or nitrogen replacement gas conditions. For example, drying conditions include a condition in which the humidity is 5% or less.

The mounting substrate A 'on which the coating liquid has been applied to the back surface and the front surface is held by the chuck (44) attached to the transport chain (43) and transported to the curing reaction section (81) by the transport means. Is done. Here, when the mounting substrate A ′ is placed under high humidity, the surface of the silicon liquid used as the coating liquid is hardened, and a desired moisture-proof / insulating coating is formed on the substrate surface. The mounting board on which the moisture-proof / insulating coating is formed is then transported to the mounting board storage section (82) by the transport means, and stored one by one in a magazine rack (83) provided in the storage section.

[0046]

The apparatus and method for coating a mounting substrate according to the present invention is an apparatus and a method suitable for using silicon having excellent moisture resistance and heat resistance as a coating agent for a mounting substrate. The mounting substrate can be automatically coated. Thus, according to the apparatus and method of the present invention, a mounting substrate having excellent heat resistance can be manufactured based on the heat resistance of silicon.

The coating apparatus of the present invention employs a free-falling method and an open system pressure-feeding method as a liquid-feeding system to quantitatively send the silicon liquid regardless of the physical properties such as compressibility and gas absorption. Liquid can be discharged. In addition, the coating apparatus of the present invention is economical and environmentally friendly because the coating liquid can be used without waste and without waste by having the circulation liquid sending system.

The coating apparatus of the present invention is provided with means for removing contaminants in the coating liquid in the circulating liquid supply system, thereby ensuring the safety and reliability of the apparatus and using a purified coating liquid at all times. Thus, the mounting substrate can be applied, whereby a mounting substrate with stable quality can be manufactured. The coating apparatus of the present invention has a configuration in which the coating with the silicon liquid is performed under the drying condition or the nitrogen gas replacement condition, so that the silicon liquid can be prevented from being cured at the time of coating or before the coating.

Further, the coating apparatus of the present invention provides efficient coating by simultaneously performing surface discharge application and back surface immersion application of a mounting substrate, and by performing surface discharge application using a plurality of selective nozzles. This makes it possible to produce a large number of mounting boards. For example, according to the apparatus of the present invention, it is possible to perform coating on a large mounting substrate (A4 size) at a rate of 1600 sheets / 8 hours.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing a circulating liquid supply system in a coating process section of a mounting board coating apparatus of the present invention.

FIG. 2 is a view of the circulating liquid feeding system shown in FIG. 1 as viewed from an I direction.

FIG. 3 is a view of a coating process section of the apparatus shown in FIG. 1 as viewed from a direction II.

FIG. 4 is an overall schematic view of a mounting board coating apparatus according to the present invention.

[Explanation of symbols]

 1. Coating liquid tank 11. Mounting substrate immersion tank 12. Next downstream tank (most downstream front tank, second tank) 13. Most downstream tank (third tank) 14. Weir 15. Outflow port 16. Partition 17. Coating liquid Contaminants (suspension) 2. Discharge section 21. On-off valve 22. Discharge nozzle 3. Liquid sending means 31. Tank 32. Tube 33. Conduit 34. Pump 35. Tube 36. Supply port 37. Tank lid 38. Coating liquid replenishment part 4. Transportation means 41. Coating position 42. Substrate placement part 43. Transportation chain 44. Chuck 45. Mounting substrate movement line 46. Chain gear rotation axis 47. Chain gear 5. Vertical drive means 51. Slide bearing 52. Vertical motion bearing part 53. Vertical drive source 54. Stand 61. Dry air blowing device (air knife) 7. Coating section 71. Mounting board supply section 72. Coating supply section 73. Magazine rack 74. Cover Post-process section 81. Cure reaction section 82. Mounting board storage section 83. Magazine rack 84. Cover 85. Humidifier 86. Steam outlet 9. Common board S: Up (down) stroke A: Mounting board (before coating) A ': Mounting board (coated)

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B05D 7/24 302 B05D 7/24 302Y F term (Reference) 4D075 AB03 AB04 AB41 AC12 AC84 CA47 DA06 DC19 EB42 4F040 AA12 AB04 AC02 BA35 4F041 AA05 AB02 BA07 4F042 AA06 CA01 CB02 CB20 CC14 DE01 5E314 AA01 BB02 BB11 BB12 CC03 CC04 EE01 FF01 GG01 GG03

Claims (12)

[Claims] A coating liquid bath for dip-coating the coating liquid on the back surface of the mounting substrate; a discharge unit for discharging and coating the coating liquid on the surface of the mounting substrate; and a feeding unit for feeding the coating liquid from the coating liquid tank to the discharge unit. A mounting substrate coating apparatus having a liquid means, wherein the discharge section is provided with an on-off valve, and discharge of the coating liquid is controlled by opening and closing the valve. A mounting substrate coating apparatus, comprising: a liquid supply system in which a liquid is combined with an open-system pressurized liquid supply interlocked with the coating liquid discharge by opening the on-off valve of the discharge unit. 2. A discharge section is provided above the coating liquid tank, and a coating substrate can be disposed between the discharge section and the coating liquid tank and coating is performed at this position, whereby the coating liquid can be circulated and sent. 2. The mounting substrate coating apparatus according to claim 1, wherein the coating apparatus is configured as follows. 3. A coating substrate disposed between a discharge section and a coating liquid tank is simultaneously coated with a front surface by discharging the coating liquid from the discharge section and a backside coating by immersion in the coating liquid tank. The mounting substrate coating apparatus according to claim 1 or 2, which is configured. 4. The discharge unit includes a plurality of discharge nozzles,
4. The discharge nozzle according to claim 1, wherein each of the discharge nozzles is controlled so as to selectively discharge and apply the coating liquid in accordance with the position of the component mounted on the mounting substrate surface. Mounting substrate coating equipment. 5. A coating liquid tank comprising at least three successive low water level tanks including a mounting substrate immersion tank, wherein the mounting substrate immersion tank and the next downstream tank are provided with a coating liquid overflowing from the immersion tank. It is partitioned by a weir so that it falls into the next downstream tank beyond the weir. 5. The liquid discharger according to claim 1, wherein the liquid is configured to flow from the front tank to the most downstream tank, and the further most downstream tank is provided with an outflow port so that the water level of the continuous tank gradually decreases. 6. A mounting substrate coating apparatus according to any one of the above. 6. A mounting substrate transfer means and a vertical drive means, wherein the mounting substrate is moved and arranged at a coating position between a discharge portion and a mounting substrate immersion tank of a coating liquid tank by the mounting substrate transfer means. By raising the coating liquid tank by the driving means, the back surface of the mounting substrate arranged at the coating position is immersed in the coating liquid of the mounting substrate immersion tank to apply the rear surface of the mounting substrate. Item 6. A mounting substrate coating apparatus according to any one of Items 1 to 5. 7. The mounting substrate is horizontally moved in a traveling direction by a mounting substrate transport means while the back surface is immersed in a coating liquid in a mounting substrate dipping tank after the dip coating of the mounting substrate, and then the coating is performed by a vertical driving means. 7. The apparatus according to claim 6, wherein the liquid tank is lowered so that the back surface is detached from the coating liquid, and the mounting substrate is horizontally moved in the advancing direction by the mounting substrate transport means to arrange the next mounting substrate at the coating position. The mounting substrate coating apparatus according to the above. 8. The mounting substrate coating apparatus according to claim 1, further comprising means for removing an excess coating solution from the coated mounting substrate. 9. The apparatus according to claim 1, wherein the coating step is performed under a dry condition or a nitrogen gas replacement condition. 10. A mounting substrate coating apparatus having a curing reaction section in addition to a coating processing section, wherein the curing reaction is set to be performed under high humidity. Mounting board coating equipment. 11. The apparatus according to claim 1, wherein a silicon liquid is used as the coating liquid. 12. A method for coating a mounting substrate, comprising a step of coating the mounting substrate with a coating liquid using the apparatus according to claim 1.