JP2969239B2 - Moisture-proof insulation paint coating equipment for printed circuit boards - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention incorporates an automatic coating device using a brush inside a storage tank storing a moisture-proof insulating paint,
The present invention relates to an apparatus for applying a moisture-proof insulating paint on a printed circuit board, which performs a moisture-proof insulation process on a solder surface of the printed circuit board by the application apparatus.

[0002]

2. Description of the Related Art It is necessary to apply a moisture-proof insulating paint to a solder surface of a printed circuit board on which electronic components are mounted in order to ensure the performance of an electronic circuit.

Conventionally, as a method of applying this moisture-proof insulating paint, as shown in FIGS. 12 and 13, a container 59 storing a moisture-proof insulating paint made of an organic solvent such as toluene is installed in an outdoor exhaust duct device 60, and manually. The brush 61 is immersed in the moisture-proof insulating paint in the container 59, the paint adhered to the brush 61 is applied to the solder surface of the printed board 62, and after the application, the printed board 62 is placed in the outdoor exhaust duct device 60 for several tens minutes. It was common to leave the paint for a while and dry the paint at room temperature by forcible exhaustion.

[0004]

However, in such a conventional method, since an organic solvent such as toluene is manually applied with a brush as described above, the paint and volatile gas are scattered,
There are safety and hygiene issues due to direct contact with the worker's skin.

[0005] In addition, for the purpose of taking measures against the environment of workers and workplaces, and safety measures, for example, the entire device is enclosed and an outdoor exhaust duct device 60 is provided.
Therefore, there is a problem that the size of the entire apparatus is increased.

Further, since the brush coating method is used by a worker, labor is required, the production cost is increased, it is difficult to make the coating film thickness uniform, and dust or the like settled at the bottom of the container is printed on the printed circuit board by brush. There is a problem that it adheres to the painted surface of No. 62 and hinders the electronic circuit.

Further, since the paint is applied to the printed circuit board 62 and then dried at room temperature by forcible exhaustion, it takes a long time to dry and a large number of printed circuit boards 6 in the drying apparatus.
There is a problem that the drying apparatus becomes large when drying 2 is attempted.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, and to stop the manual brush application method and the room temperature drying method, and to provide a moisture-proof insulation of a printed circuit board using an automatic application device using a brush and a hot air supply device. A paint application device is provided.

[0009]

In order to solve the above-mentioned problems, the present invention provides an opening corresponding to the size of a printed circuit board on an upper surface thereof, and a storage tank in which a moisture-proof insulating paint is stored inside; A coating head drive installed substantially horizontally on the upper surface side of the storage tank so as to be substantially parallel to one side of the unit, a coating head moving in the left-right direction along the coating head drive, and a rod drive on the upper side And a lower part of the brush is suspended in the storage tank, and the brush mounting body is configured to operate integrally with the coating head. The brush mounting body is rotatably mounted on the brush mounting body and is immersed in the non-painting storage tank. A moist-proof insulating paint application device for a printed circuit board is constituted by a brush portion and a brush rotating body that moves up and down by driving of the rod driving body and rotates the brush portion upward at the time of painting to hold the brush portion at a predetermined angle.

[0010] The brush portion is moved from a substantially horizontal state during painting to approximately 4
It is effective to rotate upward to an angle of 5 °, and then shift to the left and right to paint on the solder surface of the printed circuit board. Further, it is preferable to provide a cam plate for inverting the brush portion on the bottom surface of the storage tank facing the start point and the end point of the coating head.

It is desirable to provide a suitable number of dust stirring prevention plates on the bottom surface of the storage tank.

Further, the brush portion has a substantially U-shaped brush mounting frame,
An appropriate number of brushes are mounted in the mounting frame, and the mounting position can be changed by moving a screw along a slit provided on a side surface of the brush mounting frame. You can also.

[0013] Further, a drying apparatus comprising a drying furnace having an opening corresponding to the size of the printed circuit board on the upper surface in the vicinity of the storage tank, and a hot air blower for supplying hot air to the drying furnace is provided. Covering the upper surface of the apparatus and the storage tank with an exhaust cover having an exhaust port is effective in terms of drying of paint, safety and hygiene, and can reduce the size of the entire apparatus.

[0014]

According to the above construction, the brush portion is immersed substantially horizontally in the paint in the storage tank during non-painting, but at the time of painting, the rod driving body is driven to lower the brush rotating body to rotate upward. After that, it moves along the coating head driving body, and paints the solder surface of the printed circuit board installed in the opening of the storage tank from the inside of the storage tank. At this time, if the brush portion is fixed obliquely upward at an angle of approximately 45 °, the brush portion smoothly moves over the solder surface of the printed circuit board and paints.

On the other hand, when the brush portion moves to the end point position, the brush portion contacts the cam surface of the cam plate provided immediately below and reverses, moves again to the start point side along the coating head driving body, and returns to the solder surface of the printed circuit board. Paint.

When the area of the solder surface of the printed circuit board changes, the relationship between the slit provided in the brush mounting frame of the brush portion and the screw is adjusted, or the brush is replaced to match the width of the solder surface.

Further, the printed circuit board after the coating is transferred onto a drying furnace of a drying device adjacent to the storage tank, and a hot air blower is driven to dry the paint by hot air.

The harmful gas generated during these operations is collected by an exhaust cover provided on the upper surface of the harmful gas and discharged to the outside through the exhaust port.

[0019]

An embodiment of the present invention will be described below with reference to the accompanying drawings.

In FIG. 1, reference numeral 1 denotes a printed board made of bakelite or the like, on which semiconductor chips and other electronic components are mounted on a front surface, and a solder surface for electrically connecting these electronic components is formed on a back surface. Reference numeral 2 denotes a storage tank, on the upper surface of which an opening 3 corresponding to the size of the printed circuit board 1 is provided, an upward guide body 4 is provided around the opening 3, and a moisture-proof insulating paint (hereinafter referred to as paint) 5 is provided therein. Are stored, and one or more dust stirring prevention plates 6 having an appropriate height are provided on the inner bottom surface.

It is desirable that the opening area of the opening 3 can be adjusted according to the size of the printed circuit board 1.

Reference numeral 7 denotes a coating head driving body, and a guide rod 8 having a built-in permanent magnet type cylinder mechanism (not shown);
A guide rod 9 attached to the lower surface of the rod 8 and a connecting body 10 connected to both ends of the guide rods 8 and 9
And is installed substantially horizontally on the upper surface side of the storage tank 2 so as to be substantially parallel to one side of the opening 3.

Reference numeral 11 denotes a compressed air supply device, and the speed control valve 1
The compressed air is supplied to the connecting body 10 of the coating head driving body 7 through the guide rod 8, and compressed air is supplied into the guide rod 8 to move the cylinder therein to the left and right. 13,1
Reference numerals 4 denote left and right approach sensors of the coating head driving body 7 mounted on the connecting body 10, respectively.

Reference numeral 16 denotes a coating head, and guide rods 8 and 9
And a magnet (not shown) is built therein so as to be opposed to the permanent magnet of the guide rod 8.

Reference numeral 17 denotes a brush mounting member comprising an inverted L-shaped plate fixed to the coating head 16, and a cylinder mechanism 1 which moves up and down by a compressed air supply device 18 on a horizontal portion on the upper surface.
A rod driving body 20 with a built-in 9 is attached, and the lower part of the hanging part is connected to the paint 5 in the storage tank 2 through the guide slit 15.
And a spring fixing pin 21 is mounted on the way.

Reference numerals 22 and 23 denote vertical approach sensors attached to the vertical position of the rod driving body 20.

Reference numeral 24 denotes a vertically moving rod, the upper end of which is connected to a cylinder mechanism 19 in a rod driving body 20, and the other end penetrates through a horizontal portion of the brush mounting body 17 and hangs at the tip thereof.
The horizontal part of the upper surface of the brush rotating body 25 composed of a plate is fixed.

The brush rotator 25 has a hanging portion facing the storage tank 2 through the guide slit 15, and has a guide slit 26 cut out upwardly from a substantially central portion of the lower surface to cut the spring fixing pin into the slit 26. 21 is inserted.

Reference numeral 27 denotes a rotating plate, which is located between the lower part of the hanging part of the brush mounting member 17 and the lower part of the hanging part of the brush rotating body 25, and whose center is rotatable on the brush mounting member 17 by a rotating shaft 28. Installed.

Reference numeral 29 denotes a brush portion, and a connecting member 30 fixed to one end of a rotating shaft 28 on the opposite side of the rotating plate 27;
A substantially U-shaped brush attachment frame 3 attached to the coupling tool 30
1 and a brush 3 attached by screws 32 in a brush attachment frame 31 so as to be immersed in the paint 5 above the bottom surface of the storage tank 2
3 is comprised.

One or more brushes 33 are mounted in the brush mounting frame 31 in accordance with the width of the solder surface of the printed circuit board 1, and screws 32 extend along slits 34 provided on the side surfaces of the brush mounting frame 31. The mounting position can be changed by moving.

Numeral 35 denotes a cam roller, which is fixed to the outer periphery of the rotary plate 27 so as to contact the lower ends on both sides of the hanging part with a guide slit 26 provided in the hanging part of the brush rotating body 25 therebetween.

Reference numeral 36 denotes a tension spring,
When the rotating plate 27 is rotated and the cam roller 35 comes into contact with a predetermined position at the lower end of the hanging portion of the brush rotating body 25, the cam plate 35 is positioned by the compression spring force. I have to.

Reference numerals 37 and 38 denote cam plates, which are provided on the bottom surface of the storage tank 2 facing the start point and the end point of the coating head 16, and contact the cam rollers 35 of the rotary plate 27 on the surfaces facing each other. Taper surfaces 39 and 40 in contact
Is provided.

The tapered surfaces 39, 40 are inclined at an angle of about 15 ° toward the inside as they go below the upper end surfaces of the cam plates 37, 38, and guide the cam roller 35 up and down along this inclination. Like that.

Reference numeral 41 denotes an exhaust port provided at a corner on the upper surface of the storage tank 2.

Reference numeral 42 denotes a drying device, which is installed near the storage tank 2 and has a drying furnace 44 having an opening 43 on the upper surface corresponding to the size of the printed circuit board 1, and hot air flowing into the drying furnace 44. It is composed of a heater 45 with a built-in heater.
A warm air guide plate 46 for guiding warm air to the opening 43 side inside
And a guide body 47 at the periphery of the opening 43 and an exhaust port 48 at a corner of the upper surface.

A bifurcated exhaust duct 49 has one end connected to the exhaust port 41 of the storage tank 2 and the exhaust port 48 of the drying furnace 44.
The other end is connected to the exhaust port 51 of the exhaust cover 50.

The exhaust cover 50 includes the storage tank 2 and the drying device 42.
And an exhaust blower 52 is provided at an exhaust port 51.

Reference numeral 53 denotes a constant liquid level device, which is a storage container 54 containing the paint 5 and an outflow passage 55, a throttle valve 56 provided in the middle thereof,
It comprises a discharge nozzle 57 inserted into the storage tank 2 and a liquid level adjusting nut 58 for adjusting the vertical position of the nozzle 57. When the paint 5 in the storage tank 2 decreases, the container 54 and the storage tank 2 The paint 5 is automatically supplied into the storage tank 2 by the pressure relationship described above.

The embodiment of the present invention has the above configuration, and its operation will be described below.

Before use of the apparatus, that is, during non-coating, the coating head 16 is moved to the starting point side of the coating head driver 7, that is, as shown in FIGS.
As shown in FIG. 3, since it is located at the right end of the guide rods 8 and 9 and the rod driving body 20 is not operating, the cylinder mechanism 19 and the vertically moving rod 24 connected thereto are
And the brush rotating body 25 is moving upward, and the cam roller 35 of the rotating plate 27 is simultaneously moved by the compression spring force of the tension spring 36 hooked between the cam roller 35 and the spring fixing pin 21 of the brush mounting body 17. It is pulled upward about the rotation shaft 28 as shown by an arrow a in FIG.

At this time, the brush 3 attached to the rotating shaft 28
Numeral 3 is immersed in a substantially intermediate depth position in the storage tank 2 so as to maintain a substantially horizontal state by the action of the cam roller 35 and the tension spring 36 abutting on the lower end of the brush rotating body 25 described above.

Next, when coating the printed circuit board 1,
First, the printed circuit board 1 is placed on the opening 3 of the storage tank 2 with the solder surface facing down.

When the apparatus is started in this state, compressed air is supplied into the rod driving unit 20 by the compressed air supply unit 18, and the cylinder mechanism 19, the vertically moving rod 24 and the brush rotating body 25 connected thereto are lowered. The cam roller 3 pressed down and abutted on the lower left end surface of the hanging part of the brush rotating body 25
5 is also depressed and stops when it is lowered to a predetermined position, and the state is maintained by the compression spring force of the tension spring 36 as shown by the arrow b in FIG.

At the same time, the brush 33 is also lifted up to the obliquely upward state via the rotating shaft 28, and the state is maintained to enter the painting operation state. This state is the lower approach sensor 23
Is detected by the cylinder mechanism 19 according to the signal.
Stop the operation of.

The angle of inclination of the brush 33 is approximately 4 upward.
Preferably, the angle is held at 5 °, and this angle can be set by the stroke of the vertically moving rod 24.

The speed at which the brush 33 is lifted obliquely upward can be arbitrarily set by adjusting the amount of compressed air sent from the compressed air supply device 18 into the rod driving body 20. The splashing of the paint 5 attached can be prevented.

Next, when compressed air is supplied into the guide rod 8 of the coating head driving body 7 in this state, the permanent magnet therein moves to the left, and at the same time, the coating head 16 moves along the guide rods 8 and 9. Shifting to the left, the brush part 29 integrated therewith also shifts to the left, and the paint 33 is applied to the solder surface of the printed circuit board 1 by the brush 33.

Thereafter, the coating head 16 is moved to the guide rod 8,
9, the cam roller 35 of the rotary plate 27 abuts against the tapered surface 40 of the cam plate 38 provided on the bottom left side in the storage tank 2, and when the coating head 16 further moves to the left, it is moved to the end position. The left approach sensor 14 detects and stops the coating head 16, and the cam roller 35 separates from the brush rotating body 25 and moves downward along the tapered surface 40 of the cam plate 38, and the tapered surface 40.
Is also separated from the tapered surface 40 past the lower end position, and rotated 90 ° counterclockwise by the spring force of the tension spring 36,
Conversely, it is held at an angle of 45 ° from the left side. After the reversal of the brush 33, the brush 33 maintains a predetermined inclined state. However, the cylinder mechanism 19 of the rod driving body 20 is raised to raise the vertical moving rod 24 and the brush rotating body 25 once to bring the brush 33 into a substantially horizontal state, and the paint 5 The brush 33 may be immersed inside and moved up again to hold the brush in an inclined state, and these can be arbitrarily set by the electric sequence of the control circuit.

Thereafter, the coating head driver 7 is driven to move the permanent magnet in the guide rod 8 to the right, and the coating head 16 is also moved to the right to perform the coating operation again.

When the coating is completed and the coating head 16 is near the starting point, the cam roller 35 of the rotating plate 27 comes into contact with the tapered surface 39 of the cam plate 37. When the coating head 16 moves further, the power of the coating head driver 7 is changed. As a result, the cam roller 35 becomes the tapered surface 39 of the cam plate 37.
And the brush 33 is reversed in the same manner as the above-described reversing operation.

In this state, the rod driving body 20 is operated from the previous starting point state, and the vertically moving rod 24 and the brush rotating body 25 are moved.
Is the same as the state in which is lowered.

Thereafter, the cylinder mechanism 1 of the rod driving body 20
When the vertical movement rod 24 and the brush rotating body 25 are raised by moving the brush 9 upward, the brush 33 is in a substantially horizontal state, and all the other mechanisms are in a non-painting state. This state is detected by the upper approach sensor 22, and the operation of the cylinder mechanism 19 is stopped by the signal.

Thus, a series of painting operations is completed.
The number of coating operations can be arbitrarily set by an electric sequence of the control circuit.

When the paint in the storage tank 2 is reduced by this coating operation, the paint is automatically supplied from the storage container 54 to the storage tank 2 from the discharge nozzle 57 through the outflow passage 52.

At this time, the discharge amount of the paint 5 can be arbitrarily set by adjusting the vertical position of the storage container 54 and the vertical position of the discharge nozzle 57.

When the coating operation is completed, the printed circuit board 1 is removed from the opening 3 of the storage tank 2, moved to the drying device 42 side, placed on the opening 43 of the drying furnace 44, and the hot air blower 45 is driven.

As a result, the warm air is guided to the solder surface of the printed circuit board 1 by the warm air guide plate 46 to dry the paint 5 on the solder surface, and the exhaust is collected in the exhaust duct 49 and the exhaust cover 50 by the exhaust blower 52. And is discharged from the exhaust port 51.

According to the above-described embodiment, the brush 33 is not dried at the intermediate depth position in the storage tank 2 while the brush 33 is kept substantially horizontal at the time of non-painting.

Further, at the time of coating, the brush 33 is rotated obliquely upward from a substantially horizontal state at an angle of approximately 45 °, and then shifted to the solder side of the printed circuit board 1, so that the paint 5 is agitated for each coating and the surface is solidified. The brush 33 can smoothly move on the solder surface of the printed circuit board 1, and the paint can be applied uniformly.

Further, since the solder surface of the printed circuit board 1 is painted downward, that is, toward the inside of the storage tank 2, the brush 3
3 can be coated with plenty of paint 5 and excess paint can be automatically collected in the storage tank 2.

In addition, since the brush 33 is rotated once at the start point position and the end point position and can be applied twice by reciprocating operation, there is no uneven coating on the solder surface.

Further, since the dust agitation preventing plate 6 is provided on the bottom surface of the storage tank 2, dust and the like do not adhere to the brush 33 even when the brush 33 is rotated or painted.

Further, the brush 33 is connected to the U-shaped brush mounting frame 31.
The brushes 33 are fixed in place by the screws 32 and the slits 34 of the mounting frame 31, so that replacement of the brush 33 and adjustment of the mounting position are easy, and a commercially available brush can be used.

Further, since a drying device after coating is installed near the coating device for the printed circuit board 1 and the whole is covered with one exhaust cover 50, workability and safety are improved.
In addition, since the exhaust duct 49 can be shared, the size of the entire apparatus can be reduced.

In the above embodiment, the coating head driving unit 7 and the rod driving unit 20 are constituted by using the compressed air supply device and the cylinder mechanism. However, the present invention is not necessarily limited to this. For example, by using a gear mechanism or the like. Painting head 16
Alternatively, the rod driving body 20 may be driven.

The brush mounting member 17 and the brush rotating member 25 do not always need to be formed by inverted L-shaped plates, and their shapes can be changed as appropriate.

Further, the brush 33 is moved from the substantially horizontal state to about 45 degrees.
Although the coating is performed after rotating upward to an angle of .degree., The angle can be appropriately changed according to the conditions of the storage tank 2 and the printed circuit board 1, and the like.

[0070]

As described above, according to the present invention, the solder surface of the printed circuit board is placed on the storage tank in which the paint is stored so as to face the paint, and the brush is automatically arranged along the coating head drive. Since it is shifted to the left and right and painted on the solder surface, it is safer than the conventional one that performs painting work manually,
Can solve hygiene problems.

Also, the non-painting brush is immersed in the paint while being kept substantially horizontal in the storage tank, and the brush is rotated upward to apply the paint, so that the brush is dried or the paint surface is solidified. There is no.

In addition, since it is possible to apply a sufficient amount of paint to the brush, it is possible to apply the paint uniformly without forming uneven coating, and the excess paint can be automatically collected in the storage tank. .

Further, when the brush is lifted up from a substantially horizontal state to an angle of about 45 ° and painted, the movement of the brush is smooth, and when the brush is reversed at the end point and reciprocated, the paint unevenness is further reduced. A uniform coating film can be formed.

When a dust agitation prevention plate is provided on the bottom of the storage device, no dust or the like adheres to the brush, so that no dust or the like adheres to the solder surface of the printed circuit board.

Further, when the brush is sandwiched between the U-shaped brush mounting frames and fixed by the relationship between the screw and the slit, replacement of the brush and adjustment of the brush width are easy.

Further, when a drying device having a hot air blower is provided adjacent to the storage tank and the drying device is covered with an exhaust cover, the workability of drying is good and safe, and the size of the entire device is reduced. Can be.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional front view of the entire apparatus according to the present invention.

FIG. 2 is a partial cross-sectional front view for explaining the operation of the brush unit.

FIG. 3 is a partial cross-sectional front view for explaining the operation of the brush unit.

FIG. 4 is a perspective view for explaining the operation of the brush unit.

FIG. 5 is a perspective view for explaining the operation of the brush unit.

FIG. 6 is a perspective view for explaining the operation of the brush unit.

FIG. 7 is a top view of the storage tank.

FIG. 8 is a sectional view of the brush portion.

FIG. 9 is a perspective view of the brush unit.

FIG. 10 is a sectional view of an identification liquid level device.

FIG. 11 is a sectional view of the printed circuit board.

FIG. 12 is a conventional perspective view for explanation.

FIG. 13 is a perspective view for explanation of the related art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Printed circuit board 2 Storage tank 3 Opening 5 Paint 6 Dust stirring prevention plate 7 Painting head drive 8, 9 Guide rod 16 Painting head 17 Brush mounting body 20 Rod drive 25 Brush rotating body 29 Brush part 33 Brush 37, 38 Cam Plate 39, 40 Cam surface 42 Drying device 44 Drying oven 50 Exhaust cover 53 Constant liquid level device

Claims (6)

(57) [Claims] An opening (3) corresponding to the size of a printed circuit board (1) is provided on the upper surface, and a moisture-proof insulating paint (5) is provided inside.
(2), a coating head drive (7) installed substantially horizontally on the upper surface of the storage tank (2) so as to be substantially parallel to one side of the opening (3), and The coating head (16) moving in the left-right direction along the head driver (7)
A brush driving body (17) having a rod driving body (20) mounted on an upper side thereof, a lower part hanging down in a storage tank (2) and operating integrally with the coating head (16); The brush portion (2) rotatably mounted on the brush mounting body (17) and immersed substantially horizontally in the non-coating storage tank (2).
9) and a brush rotator (25) that moves up and down by driving the rod driver (20) to rotate the brush portion (29) upward at the time of coating and to maintain the brush rotator at a predetermined angle. Moisture-proof insulation paint coating equipment for printed circuit boards. 2. A brush according to claim 1, wherein the brush portion (29) rotates upward from a substantially horizontal state to an angle of approximately 45 ° during painting and is held by a brush rotating body (25), and the brush (29) 33. An apparatus for applying a moisture-proof insulating paint on a printed circuit board, wherein the solder-coated surface of the printed circuit board is coated by the method according to 33). 3. A cam plate (37) according to claim 1, wherein the brush portion (29) is turned over on the bottom surface of the storage tank (2) facing the start and end positions of the coating head (16). , (38), an apparatus for applying a moisture-proof insulating paint on a printed circuit board. 4. The method according to claim 1, wherein a suitable number of dust-prevention plates (6) are provided on the bottom surface of the storage tank (2). apparatus. 5. The brush (29) according to claim 1, wherein the brush portion (29) has a substantially U-shaped brush mounting frame (31) and a suitable number of brushes (31) mounted in the mounting frame (31). 33), and the mounting position of the brush (33) can be changed by moving a screw (32) along a slit (34) provided on a side surface of the brush mounting frame (31). An apparatus for applying a moisture-proof insulating paint on a printed circuit board. 6. The drying furnace according to claim 1, wherein a drying furnace (44) having an opening (43) on the upper surface in the vicinity of the storage tank (2) in accordance with the size of the printed circuit board (1); A drying device (42) including a hot air blower (45) for supplying hot air to the drying furnace (44) is provided.
2) An apparatus for applying a moisture-proof insulating paint on a printed circuit board, wherein an upper surface of the storage tank (2) is covered with an exhaust cover (50) having an exhaust port (51).