JPH0469835B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for forming a film on an electronic circuit board and an apparatus used to carry out the method, and more specifically to a circuit incorporating a large number of electronic circuit components. The present invention relates to a method and apparatus for forming an insulating film on a substrate by airlessly spraying a molten resin onto the substrate.

(Prior art) Conventionally, acrylic resin has been applied to electronic circuit boards to form a film for insulation or moisture proofing, and the methods include film coating and air spraying. It is used. As a film coating method, the Nordson film coating method manufactured by Nordson Corporation in the United States is well known, and in this method, as shown in FIG. 13b, molten resin is sprayed in a film form from a nozzle 200 to coat an electronic circuit board. It is something. In addition, in the air spray method, as shown in Figure 13c,
Coating is performed by atomizing and spraying molten resin using compressed air.

(Problems to be Solved by the Invention) However, in the case of the film coating method, since molten resin is coated in the form of a film, a relatively large amount of resin is required to form the film, resulting in a coating film (film coating). The coating becomes relatively thick, leading to waste of resin and causing so-called dripping after application. Furthermore, it is necessary to control the nozzle 200 in the height (z) direction so that the maximum width part of the film matches the surface height of the circuit component, so if the amount of movement in the z direction is increased, the spray pattern width will become non-uniform. The thickness of the coating film becomes non-uniform; on the other hand, when the minimum thickness is maintained, the coating film becomes excessively thick and drips also occur.

Furthermore, since the resin is discharged from the nozzle in the form of a film, the film may break 201 or contain air bubbles 202 near the boundaries of the uneven parts of the part, as shown in FIG. 13b. However, there were disadvantages in that areas with insufficient coating tended to occur. Furthermore, since it is applied in the form of a film, it cannot be applied sufficiently to the back surface of hollow supporting parts such as IC pins or lead wires, causing poor insulation or moisture proofing. Therefore, in order to deal with these inconveniences, a thicker coating film is required, and a larger amount of resin and solvent are required, making dripping more likely. When liquid drips in this way, it is inconvenient that, for example, it is not possible to immediately coat the back side of the substrate, and it is also impossible to dry the substrate while saving space by turning the substrate upside down. There is also the disadvantage that a wide range of coatings are required, and furthermore, there is also the problem that the drying time becomes longer if the coating film is thick.

On the other hand, in the case of the air spray method, it is necessary to extremely reduce the viscosity of the molten resin in order to atomize and spray the molten resin with compressed air.As a result, the amount of solvent consumed increases and the coating film thickness increases with one spray. In some cases, it was not possible to obtain a sufficient thickness, and the drying and spraying steps had to be repeated many times to obtain the desired thickness. Furthermore, when blowing off the resin attached to the nozzle tip with air, so-called stringing tends to occur.
There were also inconveniences such as unevenness occurring on the coated surface and a decrease in marketability. In particular, in the case of the air spray method, it is necessary to mask areas that should not be coated, such as LEDs (light emitting diodes), in advance because of the atomized spray, which poses the problem of requiring an extra work process. .

Therefore, the purpose of the present invention is to eliminate the above-mentioned drawbacks of the prior art, and by properly controlling the injection pressure and viscosity of the resin, no dripping occurs and the consumption of resin and solvent is minimized. It is an object of the present invention to provide a method and apparatus for forming a film on an electronic circuit board, which allows coating both the upper and lower surfaces of the circuit board to a desired thickness.

(Means and effects for solving the problem) In order to achieve the above object, the method for forming a film on an electronic circuit board according to the first invention includes a step of positioning the electronic circuit board at a predetermined position, and an insulating resin agent. 50
It is melted to a viscosity of 23 to 44 cps under the temperature condition of ℃, and while adjusting the pressure to 3 to 5 kg/cm ² , it is pumped to an injection nozzle equipped with a cat-eye hole shape, and is sprayed onto one surface of the positioned electronic circuit board. A process of airless injection while moving so as to draw an approximately elliptical injection pattern in plane and with its long axis approximately parallel to the direction of board movement, and a process of reversing the electronic circuit board after airless injection. , a step of performing airless spraying on the other side of the electronic circuit board after inversion, similar to that described in the above step, and a step of drying the electronic circuit board after airless spraying. did.

Further, the film forming apparatus for an electronic circuit board according to the second invention includes a transport rail for receiving the electronic circuit board, moves along the transport rail, and transfers the electronic circuit board to a first spraying position and a subsequent reversing position. , a transport claw that sequentially transports the electronic circuit board to a second spraying position at the subsequent stage and a drying position at the subsequent stage, an abutment clamp that fixes the electronic circuit board at the first and second spraying positions, and is movable and approximately An insulating resin having a cat's-eye nozzle hole shape and melted to a viscosity of 23 to 44 cps at a temperature of 50°C and maintained at a pressure of 3 to 5 kg/cm ² through an adjusting means is applied onto the substrate over a planar length approximately. An injector that airlessly sprays the electronic circuit board while moving to draw a circular spray pattern and with its long axis substantially parallel to the direction of board movement; The apparatus is configured to include a reversing mechanism for reversing, and a heater for heating and drying the electronic circuit board that is sprayed airlessly and transported to the drying position via the transport claw.

(Embodiments) Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. For convenience of understanding, the second invention, the device, will be explained first.

Figure 1 shows the overall configuration of this device. As shown in the figure, this apparatus consists of a conveyance section A, a model discrimination section B, a first injection section C, a reversing section D, a second injection section E, an initial drying section F, and a second drying section G. Furthermore, this apparatus is equipped with a control unit consisting of a computer, and each part of this apparatus operates in response to control commands according to a program stored in the control unit. This will be explained below.

The transport section A is composed of a rail 12 and a transport claw 14, and an electronic circuit board 16 (hereinafter abbreviated as "board") attached to a housing of an electronic control unit of an automobile or the like is placed on the rail 12. It is configured to be pushed by a conveying claw 14. The conveyance claw 14 moves the rail 12 in response to a command from the control unit 10 as described later.
The board 1 rises from the lower rest position and is placed on the rail 12.
6 is moved forward a predetermined distance and pushed, and then descended and then returned to the rest position. Incidentally, a driving means such as a motor for driving this conveying claw 14 is omitted from illustration.

Model discrimination B consists of a light transmission sensor section 18. As shown in the figure, the sensor section 18 is installed on the side of the rail 12, and includes three light receiving elements 1 such as phototransistors that receive light from a light source (not shown).
It is composed of 8a, 18b, and 18c. The three light-receiving elements are arranged in parallel in the direction of board movement, and have different outputs depending on the state of blocking transmitted light due to the shape of the casing in which the board is mounted, and are connected to the control unit via a signal line (not shown). Send on 10. Therefore, the control unit 10 can determine the type of board from the output.

The first injection part C includes an abutting clamp 20 and a restraining clamp 22, as shown in FIG. 3b,
Both clamps 20 and 22 are configured to press the substrate 16 transferred via the transfer claw 14 from both sides and fix it in a predetermined position. FIG. 5 shows details of the abutting clamp 20 (holding clamp 22), including outer cases 20a, 22a and inner cases 20b, 22b accommodated therein.
The rods 20c and 22c are attached to the tip of the inner case, and when compressed air or hydraulic pressure is sent from a power supply source (not shown) in response to a command from the control unit 10, the inner case 20
b, 22b move forward and move the rod 22c to the substrate 16.
It is configured such that it comes into contact with the casing to which it is attached.
Note that FIG. 1 is shown in a simplified manner for convenience of illustration.

The first injection section C further includes an injection mechanism 26. The injection mechanism 26 includes an X-axis arm 28 that is movable in the substrate advancing direction, a Y-axis arm 30 that is attached perpendicularly to the arm 28 and that is movable in the transverse direction, and an injector that is attached to the Y-axis arm 30. 32
Consisting of As shown in FIG. 1, the injector 32 is connected to a resin tank 36 via a pressure-feeding pipe 34, and the resin tank 36 contains a mixture of an acrylic resin for insulation and a solvent consisting of toluene/xylene. There is. A pump 40 that operates by receiving driving force from compressed air or the like from a drive source 38 is inserted into the pressure-feeding pipe 34 that connects the resin tank 36 and the injector 32, and pressurizes the resin in the resin tank 36 to a predetermined pressure. Injector 32
to be pumped to. A surge tank 41 is provided in the pressure feeding path, which removes the pulsations in the hydraulic pressure generated by the pump 40 and supplies resin at a constant hydraulic pressure. Furthermore, a heater 42 is inserted in the pressure feeding path to control the temperature of the pressure fed resin.
More specifically, in addition to managing the viscosity to a set value,
A regulator 44 is inserted to keep the hydraulic pressure constant. Further, a return side pipe 46 is connected to the injector 32 in parallel with the pumping side pipe 34, and the molten resin is configured to circulate through the injector 32 via both pipelines 34, 36. Incidentally, the reference numeral 48 indicates a filter, and the reference numeral 50 indicates a distributor. Further, an exhaust duct 52 is provided below the rail 12 to recover toluene and the like contained in the molten resin. Although not shown, in this device, the upper part of the rail 12 is covered with a housing and is isolated from the outside air.

Here, the above-described injection mechanism 26 will be further explained with reference to FIGS. 6 to 10. As shown in FIG. 7, the X-axis arm 28 includes a slider 28b connected to a threaded rod 28a by a ball screw. The slider 28b is moved by the threaded rod being rotated by a servo motor 28d connected via a coupling 28c. As shown by the imaginary line in the figure, the slider 28b of the X-axis arm
A Y-axis arm 30 is attached to the Y-axis arm 3.
The injector 3 described above is placed on the slider 30b of
2 is attached via the attachment member 54. FIG. 8 is a sectional view showing details of this injector 32. A piston rod 32a is housed inside the injector 32, and a valve 32b is provided at the tip thereof. Spring 32c is piston rod 32
The valve 32b is biased in the closing direction via a,
When the solenoid valve 32d opens and compressed air is supplied from the air supply source 32e, the valve 32b is pushed upward and the circulating resin is guided into the passage 32f, and the nozzle 3
It is injected from a 2g Cat Eye 32h. 9th
The figure is a front view of the nozzle 2g viewed from the substrate 16 side in FIG. 8. The cat eye 32h is formed in the shape of a long hole as shown in the figure, and has a slightly larger diameter in the width direction near the center.
Moreover, FIG. 10 shows its injection pattern.

Returning to the description of the entire apparatus, the reversing section D includes a reversing mechanism 60 as shown in FIG. 12 (omitted in FIG. 1 for convenience of illustration). The reversing mechanism 60 includes plate bodies 62, 6 arranged oppositely on both sides.
2 and rotary disks 64, 64 which are rotatable from the plate body and similarly arranged opposite to each other. As shown, circular and I-shaped openings are bored in the plate body 62 and the rotating disk 64, and rails 12a are spanned over appropriate positions of the I-shaped openings on the rotating disk side. Note that this rail 12a is cut and separated from the rails 12 before and after the reversing portion D.
Further, a pulley 66 is provided on the side of the rotating disk 64, and a belt 68 is stretched around it, and when the pulley 66 rotates in accordance with the rotation of the motor 70, the board 16 on the rail 12a is rotated accordingly. It is composed as follows. The reference numeral 72 indicates a limit switch, and the reference numerals 74 and 74 indicate protrusions. During rotation, the protrusion 74 comes into contact with the limit switch 72 at a predetermined position, that is, a position rotated 180 degrees, and stops the rotation. Note that the board 16 on the rail 12a is fixed from both sides via restraint means (not shown).

The second injection section E has substantially the same configuration as the first injection section C described above. That is, it similarly includes an abutting clamp 78 and a holding clamp 80, as well as an X-axis arm 82, a Y-axis arm 84, and an injector 86, and the injector 86 is connected to the pressure-feeding pipe 8.
8 and a return pipe 90. Note that the reference numeral 92 indicates a filter, and the reference numeral 94 indicates an exhaust duct. Here, to further explain the resin return path, the return side pipes 46 and 90 of both injection parts are connected to a three-way valve 87 via a distributor 50 and a filter 92. By means of this three-way valve 87, the returned resin returns to the pump 40 through a branch path 89 and is sent out again during normal times, and returns to the resin tank 36 through a branch path 91 when liquid is drained when work is stopped.
Note that the valve 87 is closed when the apparatus is stopped. A back pressure regulator 93 is provided in the branch path 89, and controls the pressure of the return resin to ensure the injection pressure from the nozzle. Further, reference numeral 95 has the same configuration as the regulator 44 for the first injection part C and has a setting of 3.
~5Kg/cm ² regulator is shown.

The initial drying section F includes heaters 96, 96, which are installed at appropriate positions on the substrate 16, and are configured to blow hot air onto the substrate 16 to initially cure the coated surface. Also, heaters 96,9
Fans 97, 97 are provided at the back of the rail 12 to supply fresh air, and hot air is sucked through a blower (not shown) provided on the side of the rail 12.

The second drying section G is equipped with a belt conveyor 104 composed of rollers 100, 100 and an endless belt 102 stretched between them, and a suitable number of box-shaped cups 106 are mounted on the endless belt 102. be done. The cup 106 is configured to partially house the substrate 16 therein and hold the substrate 16 in an inverted position on top of the conveyor belt. The reason why the substrate 16 is turned upside down is to reduce the space it occupies in the transport direction. or,
At the top of the belt conveyor 104, fans 108a, 108b, 108c,
108d are arranged in parallel, and fan 1
A heater 110 is provided below 08a.
Note that the reference numeral 112 indicates a controller that controls the temperature of the heater 110, and the reference numeral 114 indicates an exhaust duct.

Next, the first invention, the film forming method, will be explained while explaining the operation of the present apparatus. Figure 2 shows the flowchart of the control unit 10 that controls the operation of this device.
FIG. 3 is a process diagram showing an embodiment of the first invention.

The operation of this device will be explained according to the flow chart in FIG. 2. In step 130, the board 16 is transported by the transport claws 14 on the rail with its component mounting side facing up. As shown in a, the model is first determined by the light transmission sensor section 18. In this case, three pairs of light receiving elements 18a, 18
The outputs of b and 18c are as shown in FIG. 4, for example, and three types of substrates can be distinguished from the output results. In the figure, "0" indicates no output from the light receiving element, and "1" indicates output. In particular, the output of the light receiving element 18a is also used to determine the presence or absence of the substrate 16.

After the model discrimination is completed, the substrate 16 is then pushed to the first injection section C by the conveyance claw 14 in step 132. The substrate 1 at the first injection part C
6 is pressed and positioned by the abutment clamp 20 and the restraining clamp 22 from a direction perpendicular to the conveyance path (step 134). In this case, since the transport claw 14 is in contact with the rear of the substrate 16, it is fixed in a predetermined position by being pressed from the side by the rods 20c, 22c of both clamps.
Note that the protruding pressure of the protruding clamp 20 is relatively large,
The holding clamp 22 is set relatively small. Therefore, the fixed position in this case is step 130.
Control unit 10 according to the board model determined by
Determined by the stored program.

Next, in step 136, molten resin is injected onto the component side of the substrate 16 via the injection mechanism 26. In this case, the acrylic resin and the solvent (toluene or xylene) are mixed in the resin tank 36 at a ratio of 1:1, and by setting the temperature of the heater 42 to 50°C, the viscosity of the resin is increased from 23°C to 23°C.
The injection pressure from the injector 32 is set to 44CPS, preferably around 36cps, and the injection pressure from the injector 32 is 3 to 5.
Kg/cm ² , preferably around 4 Kg/cm ² , so the cat eye 32 of the injector 32
The molten resin discharged from h is sprayed in the form of atomization, as shown in FIG. 13a. In the case of the forming method according to the present invention, compared to the conventional air spray method, since the spraying is performed without the aid of compressed air, the spraying pattern is relatively narrow as shown in FIG. 10, and the mask work is performed. This is not necessary, and the thickness of the coating film can be made relatively thin compared to conventional film coating methods, and the spray can be applied sufficiently to the back side of the hollow support portion by spreading the spray around. What is characteristic here is that at a temperature of 50℃
Regulator 44,95 melted resin at 44cps
Since the pressure is adjusted to 3 to 5 kg/cm ² through the injector 32 and discharged from the cat eye 32h, the pressure is increased at the constriction section at both ends of the cat eye 32h, creating tension between the resin particles, as shown in the figure. The reason is that a film is formed around the resin being sprayed as shown in the figure. This film becomes thickest near the exit of the Cat's Eye 32h, and
It becomes thinner as it descends, and when it descends by 40 mm, the tension between the particles is lost and the particles disperse and become atomized. FIG. 13a is an explanatory cross-sectional view of the jetting state before the jetting pattern shown in FIG. 10 is formed, viewed from the direction perpendicular to the long axis, that is, from the lateral direction. Although the thickness is thinner than that of the atomized resin, it is formed so as to wrap around the longitudinal direction of the atomized resin and prevent it from scattering. In this case, the film thickness is about a few hundred microns.
The injection mechanism 26 moves according to the stored program of the control unit 10, and the injector 32 (or nozzle 32g) moves along the rail while keeping the long axis of the cat eye 32h parallel to the traveling direction of the board 16, as shown in FIG. 12, while reciprocating in a direction perpendicular to 12, moving in the substrate advancing direction (or backward direction),
The molten resin is injected from the same height that is appropriately set to the substrate 16, for example, 40 mm or more. Although the height of the nozzle is not controlled in this embodiment, it goes without saying that the height direction may be adjusted.
During this airless spraying, the moving speed and pitch "p" (Fig. 11) of the nozzle are controlled according to the amount of coating per unit area, in other words, the effective area of the coating. In section 120, injection is stopped. This is to avoid overcoating on the moving path and to prevent waste of resin or occurrence of liquid dripping. In addition, the moving speed and feed pitch p of the nozzle should be determined when the size (height) of the parts is large and the integration density is high, or where there are parts such as CPUs, connectors, etc. that are highly important for insulation and moisture-proof leakage. Then, the speed should be slowed down or the pitch p should be narrowed.

Next, in step 138 shown in FIG. 2, it is confirmed that the coating on the component side of the board 16 is completed, and then in step 140, the rods 20c and 20c of both clamps are
22c is separated from the substrate 16 to release the positioning state. Subsequently, the substrate 16 is transported in the advancing direction by the transport claw 14, and is transported into the reversing mechanism 60 of the reversing section D, where it is rotated by half a rotation, and its solder side is directed upward (steps 144, 146). FIG. 3c shows this situation. That is, since the coating is applied to only the minimum necessary thickness by airless spraying, no liquid drips, and the substrate can be immediately turned over.

When the reversing operation is completed, the transport claw 14 is raised as the reversing mechanism 60 stops, and the substrate 16 is transferred to the reversing mechanism 6.
0 and transferred to the second injection section E (step 148). At this position, the same operations as those in the first injection section described above are performed to perform positioning and injection (steps 150, 152). Figure 3d shows this situation. Subsequently, when it is confirmed that the solder side coating is completed (step 154), both clamps 78 and 80 are retracted, the positioning of the board 16 is released (step 156), and the board 16 is transferred to the initial drying section F. (Step 158). Note that the application order may be such that the solder side is applied first and the component side is applied last.

In this initial drying section F, as shown in Figure 3e,
Heating and drying is performed by drawing in outside air using the fan 97 and heater 96, and the coated surface is initially cured (step 160).

When this initial drying is finished, the substrate 16 is transferred to the transport claw 1
4 to the second drying section G, and the tip thereof is inserted into the cup 106 as shown in FIG. 162). In this state, heated air is first blown by the heater 110 and the fan 108a to heat and dry the substrate. Next, three fans 108b, 108
c and 108d to dry at room temperature (step 164). Note that the drying time in this second drying section G is, for example, 13 minutes. As mentioned above, since the coating is applied to only the minimum necessary thickness by airless spraying, there is no dripping even if the substrate is left upside down for a long time (13 minutes) with only a short initial drying time. This state is shown in Figures 3g and 3h. Finally, as shown in FIG. 3i, the board 16 is taken out from the belt conveyor and the process ends
166). Note that it is convenient to provide an opening on the side surface of the cup 106 to improve air permeability, as this will facilitate drying.

In the above embodiment, the type determination of the electronic circuit board 16 was performed only before the first injection part, but the invention is not limited to this, and it may be performed at a position after positioning is completed. It may be executed again after positioning is completed in front of part E, which makes it possible to reconfirm the model when resuming work after work has been temporarily interrupted, and avoids erroneous coating. .

(Effects of the Invention) As described above, the present invention includes forming a film around the atomized resin to prevent it from scattering while spraying the resin agent onto one of the upper surfaces of the electronic circuit board. Since it is configured to perform airless spraying while at the same time turning around and spraying airlessly on the other surface on the upper side, problems such as dripping or unnecessarily thick coating may occur in the area where the spray was applied earlier during coating. The required thickness can be achieved with minimal resin and solvent consumption. In addition, since there is no dripping in the area where the spray was applied earlier during coating, the substrate can be immediately turned over and spraying on the back side can be carried out quickly, and the thickness of the coating film is not required. Since it is not thick, the drying time can be minimized, and the drying process line length can be shortened. Furthermore, since the resin is atomized and applied, even if there are irregularities on the component mounting surface, it can be reliably applied to the side surfaces or the back of hollow support parts such as IC pins, and the spray pattern is spread out unnecessarily. This has the advantage of eliminating the need for mask work. In addition, since the spray pattern is designed to draw a spray pattern that is approximately elliptical in plane, and to spray airlessly while moving so that its long axis is approximately parallel to the direction in which the substrate travels, for example, Compared to the case of moving and spraying while drawing a circular spray pattern consisting of In this case, since there is little overlap between the coated films, coating unevenness can be reduced.

[Brief explanation of drawings]

FIG. 1 is an explanatory perspective view showing the overall configuration of a film forming apparatus for an electronic circuit board according to the second invention, and FIG. 2 is a flowchart showing the control operation of a control unit in the apparatus.
3 is an explanatory process diagram showing an embodiment of the method of forming a film on an electronic circuit board according to the first invention, FIG. 4 is an output diagram of a light transmission sensor showing the model discrimination operation, and FIG. 5 is an abutting clamp ( Fig. 6 is an explanatory perspective view showing the external shape of the injection mechanism, Fig. 7 is an explanatory sectional view of its X-axis and Y-axis arms, and Fig. 8 is an explanatory sectional view of the injector. ,
FIG. 9 is a front view of the nozzle of the injector, the first
Fig. 0 is an explanatory diagram of the injection pattern, Fig. 11 is an explanatory diagram showing the movement locus of the nozzle, Fig. 12 is an explanatory perspective view showing details of the reversing mechanism, and Figs. It is an explanatory view showing airless injection in . 10... Control unit, 12, 12a... Rail,
14... Conveyance claw, 16... Electronic circuit board, 18... Light transmission sensor section, 26... Injection mechanism, 32... Injector, 32g... Nozzle, 36... Resin tank, 60...
Reversing mechanism, 64... Rotating disk, 66... Pulley, 68
...belt, 70...servo motor, 86...injector, 96...heater, 104...belt conveyor,
106...Cup, 108a, 108b, 108
c, 108d...Fan, 110...Heater, A...Transportation section, B...Model identification section, C...First injection section, D...Reversing section, E...Second injection section, F...Initial drying section, G...Second drying section.

Claims (1)

[Claims] 1 a. A step of positioning the electronic circuit board at a predetermined position; b. A step of adjusting the insulating resin material to a viscosity of 23 to 23 at a temperature of 50°C.
It is melted at 44 cps, and while adjusting the pressure to 3 to 5 Kg/cm ² , it is force-fed to an injection nozzle equipped with a cat-eye hole shape, and a spray pattern having a roughly elliptical planar shape is formed on one surface of the positioned electronic circuit board. c) reversing the electronic circuit board after airless jetting; d) electronic circuit after reversing. An electronic circuit board characterized by comprising: a step of performing airless spraying on the other surface of the substrate in the same manner as described in step b; and e) a step of drying the electronic circuit board after the airless spraying. film formation method. 2 a. A transport rail for receiving the electronic circuit board; b. Moving along the transport rail, the electronic circuit board is placed at a first spraying position, a reversing position at a subsequent stage, a second spraying position at a subsequent stage, and a drying position at a subsequent stage. c) an abutment clamp for fixing the electronic circuit board at the first and second injection positions; d) a movable nozzle hole having a roughly cat-eye shape; and a temperature of 50°C. Viscosity under conditions 23 ~
Pressure 3-5 through regulating means melted to 44cps
The insulating resin agent held at Kg/cm ² is sprayed onto the substrate in such a way as to draw a roughly elliptical spray pattern in plan.
and an injector that injects airlessly while moving so that its long axis is approximately parallel to the board collection direction; e) a reversing mechanism that reverses the electronic circuit board transported to the reversing position via the transport claw; and f An apparatus for forming a film on an electronic circuit board, comprising: a heater that heats and dries the electronic circuit board that is airlessly sprayed and transported to a drying position via the transport claw. 3. The reversing mechanism includes two rotating disks that are arranged opposite to each other, and between which a separated conveyor rail section is spanned between a first injection position on the front stage side and a drying position on the rear stage side; and a driving means for driving a rotating disk.
An apparatus for forming a film on an electronic circuit board as described in 1.