JPH0338269A - Flux coating apparatus - Google Patents

Abstract

PURPOSE:To uniformly apply flux by mounting a plurality of nozzles injecting flux, a nozzle support and an excessive flux discharge means to the under surface of a printed circuit board. CONSTITUTION:A printed circuit board 9 is inserted in an engaging groove 42 to be fed in a flux coating machine 1. When the leading end of the printed circuit board 9 reaches the place of nozzles 26, this state is detected by an optical sensor and the nozzles 26 are operated to inject flux in a mist form. The flux from each of the nozzles 6 expands radially to be applied to the printed circuit board 9. By expanding the flux radially, outer peripheral region parts overlap each other to apply the flux in a uniform thickness. When a dust collector 63 is operated, the air above a feed passage is sucked and excessive flux is not bonded to the surface of the board 9 and subjected to pulverization treatment by a filter part. By this constitution, certain soldering is performed.

Description

Detailed Description of the Invention (a) Industrial Application Field The present invention uses an activator (hereinafter referred to as flux) that makes soldering easy and reliable when soldering to a printed circuit board.
The present invention relates to a flux coating device that coats a printed circuit board with flux as a pretreatment thereof.

(b) Prior Art When soldering a printed circuit board loaded with a large number of electrical circuit components, flux is generally applied to the printed circuit board before soldering. This flux may be in the form of a paste or in the form of a viscous solvent. Flux melts at high heat during soldering and improves solder adhesion.

By the way, as a method of applying this flux to a printed circuit board, the following methods (types) have been conventionally adopted within the shell.

■ A foam type that forms a large amount of flux bubbles on the surface of the flux solvent placed in a flux tank, and applies the flux by letting the bottom surface of the printed circuit board come into contact with the flux bubbles and passing them through.

■ Air, etc. is sent into a flux solvent tank to form a flux jet that partially swells up on the surface of the flux solvent, and the bottom surface of the printed circuit board is brought into contact with the tip of this jet and applied by passing through the jet. type.

(c) Problems to be Solved by the Invention However, in the conventional methods related to the bubble type described above and the jet type described above, it is difficult to apply flux to a printed circuit board with a uniform thickness, and There are areas where a lot of flux is applied and it is applied thickly, and on the other hand, there are areas where the flux is applied too thinly or not at all.

Therefore, when the next soldering process is carried out with such uneven flux application, there will be areas where the soldering is not done or where the soldering is insufficient, resulting in poor soldering. This will occur more frequently on printed circuit boards.

On the other hand, since flux is originally an insulating substance, it is necessary to remove it from the printed circuit board after soldering so that it does not remain as a non-conducting part in the circuit network of the printed circuit board.

Therefore, the printed circuit board after this soldering is usually cleaned using a separate cleaning device that uses Freon as a cleaning agent to remove the flux as well as impurities such as microscopic dust and grime adhering to the printed circuit board. It is carried out. However, in recent years, there has been a tendency for restrictions to be imposed on the use of fluorocarbons due to environmental protection issues such as their negative impact on the formation of the atmospheric layer (ozone layer), and the use of fluorocarbon cleaning equipment has become inappropriate.

In this way, it is best if the flux can be applied thinly and uniformly to the lower surface of the printed circuit board so that cleaning with Freon is not required after application of the flux.

However, with conventional methods, it is very difficult to apply flux uniformly, and it is difficult to apply flux uniformly to printed circuit boards of various sizes. There wasn't.

The present invention has been developed in view of the above-mentioned points, and provides a flux coating device that enables uniform flux coating regardless of the size of printed circuit boards, and also provides a simple and easy-to-handle flux coating device. The purpose is to

(d) Means for Solving the Problems The flux coating device according to the present invention has a plurality of nozzles disposed below the conveyance path of the printed circuit board for spraying flux in the form of mist, and a dust collector provided externally. The configuration is such that air is sucked in above the conveyance path and excess flux is discharged to the outside, where it is then processed by a dust collector. In addition to being able to slide freely on the support, the nozzle support can be raised and lowered to slightly adjust its height relative to the printed circuit board surface, and the nozzle support can be moved as a whole so that the nozzle is centered on the printed circuit board. It is something that exists.

(E) Function When the printed circuit board is transported by the transport means, flux is sprayed in a mist form from the nozzle to perform coating.

On the other hand, air is sucked above the printed circuit board due to the operation of the dust collector. Combined with this upward suction flow of air, the flux is effectively sprayed in atomized form, and the flux is thinly and uniformly applied to the printed circuit board. The surplus flux after application is guided by suction air to a dust collector via a collection duct and an exhaust duct, and is pulverized by the dust collector.

Here, if the width of the printed circuit board is different, the nozzles are slid and adjusted to widen or narrow the distance between the nozzles to achieve an appropriate arrangement according to the width of the printed circuit board. In other words, the radially expanding flux application area covers the entire width of the printed circuit board, thereby making it possible to apply the flux with a uniform thickness.

Also, when adjusting the flux layer thickness, move the nozzle up and down to bring the nozzle injection port closer to or away from the printed circuit board, adjust the fluff layer thickness, set the optimal thickness, and adjust the flux to be used. Achieve an appropriate thickness depending on the viscosity of the material. After doing this, move the entire nozzle support so that the nozzle is in the center of the printed circuit board, making it possible to coat and form a very uniform and thin flux layer on any printed circuit board, regardless of its size. It easily and reliably intimidates people.

(f) Example The present invention will be explained in detail below.

FIG. 1 shows the configuration of the flux coating apparatus of the present invention, which is comprised of a flux coating machine according to an embodiment of the present invention, a duct for discharging surplus flux after coating, and a dust collector for collecting and pulverizing the surplus flux. The figure is shown below.

In the same figure, a printed circuit board with a large number of circuit components mounted thereon is loaded into the flux coating machine 1 from the front side in a direction perpendicular to the drawing through an inlet 2, and flux is applied to the lower surface of the printed circuit board.

The next process, soldering, is carried out from behind, so it is released from the rear. The printed circuit board is sent slightly upward from the loading port toward the loading port. Then, flux is sprayed and applied in the form of mist to the printed circuit board in a flux coating machine 1. Reference numeral 61 designates a bellows-shaped duct that guides excess flux out of the flux applied to the printed circuit board to the dust collector. The duct 61 is supported by chain hanging tools 62, 62, . . . from the ceiling surface. 63
is a dust collector, which is equipped with a suction fan (not shown) at an appropriate location inside the flux applicator l to suck and draw out surplus flux from the flux applicator l through the duct 61, and also has a part of filter (not shown) for the suctioned surplus flux. Be prepared.

In a part of the filter, excess flux is pulverized and collected, and the air that has passed through part of the filter is exhausted to the outside from an exhaust duct 61 provided at the front.

When a part of the filter is vibrated by a vibration device (not shown), the powdered flux collected on a part of the filter is removed and accumulated in a suitable receiver provided below. This will be handled as appropriate when the receiver is removed.

Next, the flux coating machine 1 will be explained.

The external appearance is as shown in FIG. 2, and the main internal structure is as shown in FIG. 3. In Fig. 2.3, the flux applicator 1 consists of a lower case 3 serving as a square base and a trapezoidal upper case 4 above it. is provided, and various necessary parts are housed inside, such as an air tank 6 for operating the flux injection nozzle, which will be described later, an alcohol tank 7 for cleaning the support piece that conveys the printed circuit board, and a pump 8 for circulating alcohol. There is. A plurality of flux injection nozzles are installed in an upper part of the lower case 3 near the bottom surface of the upper case 4 to spray flux in the form of a mist and apply it to the lower surface of the printed circuit board 9. On the other hand, on the right side of the upper case 4, there is a printed circuit board 9.
An inlet 2 is provided, and an outlet (not shown) is provided on the opposite left side. The conveying means for holding the printed circuit board 9 and conveying it in a slightly upward horizontal direction from the loading port 2 to the loading port is composed of a pair of conveying chains 1O210' installed opposite each other, and this conveying chain 10.1
A large number of L-shaped support pieces 11.11... installed at 0'.
During this time, grip both edges of the printed circuit board 9. 1
2.12 shows the cover of the conveyor chain 10) 10',
One of the conveyor chains 10 and 10' is fixed, and the other 10' is fixed in the front and back direction (arrow a
), and the facing interval can be adjusted according to the width of the printed circuit board 9 being transported.

Numeral 13 is a rotating handle for this purpose, and when it is manually rotated in either the left or right direction, the conveyor chain 10' moves back and forth. Note that the detailed moving mechanism will be described later. On the right side of the front of the upper case 4, there are a power button and various operation buttons.
It has an operation panel section 17 with operation knobs 14, adjustment heirs 15, and various meters 16 attached, and a part of the left side thereof has a glass window so that the internal operating status can be monitored. 18, and has an opening/closing cover 20 whose entirety can be opened upward by a handle 19 for inspection, repair, etc. From the top surface of the upper case 4, the upper end of the cylindrical portion of a surplus flux collection hood, which will be described later, protrudes and serves as a duct connection port 21 with the exhaust duct 61. As shown in FIG. 3, a collection hood 23 is disposed in the upper case 4 so as to cover the upper part of the conveyance path 22 of the printed circuit board 9, and this collection hood 23 is installed inside the dust collector 63. A suction fan sucks the air around the bottom, and as a result, among the mist-like flux applied to the bottom surface of the printed circuit board 9, the remaining flux after application (surplus flux) is sent to the outside through the collection hood 23 along with the air. This makes suction and extraction more effective. Therefore, this collection hood 23 and the exhaust duct 61 constitute a surplus flux discharge means. 24 is a flux discharge pump, 25 is a flux storage tank, and 25' is a flux controller. In this embodiment, there are three nozzles 26, 26, which spray flux in the form of a mist, and fixed rods 27 are arranged at equal intervals. It is fixedly attached to. These nozzles 26
26.26, by loosening the fixing screw 28, it becomes possible to freely slide left and right (arrows) on the fixing rod 27, and the mounting position can be adjusted.

29 is a spline shaft that serves as the driving force for the conveyor chain 10.10' and is rotated by a motor. 30.30 is a bevel gear fixed to the spline shaft 29, 31.31' is a rotating shaft that directly drives and rotates the conveying chain 10.10', and a bevel gear 32. 32, to which the rotational force of the spline shaft 29 is transmitted, and a conveyor chain 1 at the upper end.
Sprocket 33.33 on which one end of 0.10' is hung
has. The other end of the conveyor chain 10.10' is hung on a rotating shaft that pairs with each of these rotating shafts 31.31' (located at the rear of each rotating shaft 31.31' in the drawing), and is attached to the upper end of this rotating shaft. It also has a sprocket. The conveyor chain 10.10' has an L supporting the printed circuit board 9.
Letter-shaped support pieces 11, 11... are attached. 34
When the IID of the printed circuit board 9 to be transported changes, it is rotated forward and backward by the rotary handle 13, causing one transport chain 10' to reciprocate horizontally along the axis, while the other transport chain is in a fixed state. 10 is a rotating shaft that allows adjustment of the distance between the two.

Regarding the above-mentioned position adjustment of the flux injection nozzles 26, 26.26, the drive mechanism of the conveyance chain 10.10', and the interval adjustment mechanism of the conveyance chain 10.10', see FIGS. 4 to 8. Further explanation will be given based on these figures to the order of 0 as will be understood. 1^ indicates the main body of the flux coating machine 1. A printed circuit board 9 with a large number of circuit components mounted thereon is inserted into the main body IA from the upper entrance side, and after being coated with flux, is inserted from the lower exit side. It will be carried out. A spline shaft 29 and a motor 48 for driving the spline shaft 29 are provided at the exit side position of the base frame IB.
The rotational force is transmitted to the spline shaft 29 by the power chain 35.

The spline shaft 29 has a plurality of grooves 36, 3 on its surface.
6... are formed in the axial direction, and these grooves 36, 36...
The bevel gears 30, 30 are coupled to the spline shaft 29 by fitting the teeth 37, 37, . . . on the inner circumference thereof. Of the pair of rotating shafts 31.38.31'38' on which the conveyor chain 10.10' is stretched, one rotating shaft 31.
31' A 0-rotation shaft 31 is provided with a bevel gear 32.32 at the lower end and meshes with a bevel gear 30.30 of the spline shaft 29.
．． Reference numeral 31' denotes vertically elongated cylindrical bearing parts 40, 40 with bearings 39 and 39 disposed on the upper and lower sides, which support them in a vertical state. The remaining rotating shafts 38 and 38' have a similar bearing structure. Sprockets 33, 33° 33, 33 are integrally formed at the upper end of each rotating shaft 31, 38, 31', 38', and each pair of sprockets 33, 33
, 33.33, a conveyor chain 10.10' is stretched. As shown in FIG.
．． It is a well-known structure connected by 41..., and the connecting bin 4
1.41...The teeth of the sprockets 33 and 33 engage in between to rotate. And this chain piece 10a.

10a... L-shaped support pieces 11, 11... are caulked and fixed vertically. A locking groove 42 opening in a substantially V-shape is formed at the tip of the horizontal bent portion at the lower end of the support piece 11.

Therefore, both side edges of the printed circuit board 9 are engaged between the locking grooves 42, 42 in the support pieces 11, 11... of the opposing conveyor chains 10, 10', and the printed circuit board 9 is held horizontally. and transport it. Furthermore, transfer chain conveyors 43, 43 are provided which are rotatably operated by receiving rotational power from the spline shaft 29 so that the printed circuit board 9 that has been carried out can be smoothly transferred to the next process. One of them is shown in FIG.

That is, 44 is a drive gear fixed to the spline shaft 29, and a transfer chain conveyor 43, 43 is hung between it and the other driven gear 45, and the lower edges of the printed circuit board 9 are connected to the transfer chain conveyor 43, 43. 43 and transported. And this transfer chain 43
．． Reference numeral 43 has adjustment slots 64, 64, and the mounting screws 65 and 65 that can be moved therein so that they can be moved in and out slightly forward and backward. Furthermore, on the entrance side where the printed circuit board 9 is received, there are also transfer chain conveyors 43' and 4 having the same structure.
3' is provided, and this transfer chain conveyor 4
3', 43' is transmitted from the rotating shaft 38.3', 43'.
The receiver is configured to be transmitted from 38'. Furthermore, the locking grooves 4 of the support pieces 11, 11, . . . of the printed circuit board 9
One rotating shaft 3 rotates the conveyor chains to, to' in order to remove flux attached to the shafts 2 and 42.
From 8.38', there is provided a support piece cleaning brush 46.46 which rotates by receiving rotational power.

The brushes 46, 46 are led from the alcohol tank and face pores through which the alcohol liquid is discharged, and the flux is dropped together with the alcohol liquid.

By the way, in addition to the spline shaft 29, the base frame IB includes:
Two rotating wheels 34, 34 that are rotatably supported by bearings 47, 47, . On the other hand, conveyor chain 1
0' and its rotating shafts 31', 3g', etc., one support frame 50' is slidably attached to the rotating shafts 34, 34. For this purpose, nut members st, st are attached to the support frame 50', and the nut members 51, 51
The rotation shafts 34 and 34, which are screwed into the screws 49 and 49 of the rotation shafts 34 and 34, have a power transmission chain 52 hooked to one end of the shaft. When the rotary handle 13 is manually rotated in either the forward or reverse direction, the supporting frame 50', which is attached to the rotation shafts 34, 34 by the nut members 51 and 51, is rotated in the left and right directions (arrows) in the drawing. a) It is movable.

The width of the interval between opposing conveyor chains 10, 10' can be varied. This means that even if the l1liTD of the printed circuit board 9 changes, the conveyance path width can be adjusted to match the width, and the support pieces 11. It is possible to transport. Note that the other conveyor chain 10. The other support frame 50 provided with the rotating shafts 31, 38, etc. is the base frame IB.
It is fixed with screws 53 and 53.

Next, the attachment mechanism of the nozzles 26, 26.26 and their position adjustment will be explained. The nozzle fixing frame 54 has a guide rod 55 and a fixing rod 27, and each nozzle 26, 26, 26 has its mounting portion 26', 26', 26' slidably inserted into the guide rod 55, and the fixing rod 27・Fixing screw 28.28.28
By tightening the nozzles 26, 26.26 are fixed. Fixing screws 28 , 28 .

When 28 is loosened, the nozzles 26, 26, 26 can freely move along the guide rod 35, so they can be adjusted to appropriate positions and fixed again by tightening the fixing screws 28, 28, 28. If the mounting position of the nozzles 26, 26.26 can be adjusted in this way, the nozzles 26, 26.2 can be adjusted according to the width of the printed circuit board.
By appropriately adjusting and changing the interval between the nozzles 26 and 6,
The flux sprayed from ゜26.26 is printed on the printed circuit board 9.
It becomes possible to apply the coating uniformly to the surface.

In addition, the entire nozzle fixing frame 54 is fixed with a vertical movement adjustment screw 56.
Assuming that the nozzle can be moved up and down slightly by
By moving the nozzle 6 closer to or farther away from the lower surface of the printed circuit board 9, the layer thickness of the flux applied to the lower surface of the printed circuit board 9 can be adjusted and the optimum thickness can be set. A mechanism is adopted in which the nozzles 26, 26.26 attached to the nozzle fixing frame 54 at appropriate intervals are automatically brought to the center of the printed circuit board 9 as a whole. That is, another frame 57 is provided that is integrally connected to the nozzle fixing frame 54, and both ends of this frame 57 are connected to each other. ! 57', 57
' is inserted into the support rod 58. And this both end walls 5
On the inside of 7' and 57'.

When the motor 59 rotates, both ends of a drive rod 60, which reciprocates in the left-right (arrow) direction, come into contact with each other through a suitable power transmission mechanism, such as a worm or a gear.

With this configuration, the drive rod 60 can be connected to the motor 5.
9 moves in one direction, the frame body 57 is pushed by it and slides on the support rod 58, and the entire nozzle fixing frame 54 is moved to control the nozzles 26, 26, and 26 to come to the center of the printed circuit board 9. I can do it. If the motor 59 is rotated in the opposite direction, the nozzle fixing frame 54 will move in the opposite direction. The forward and reverse operations of the motor 59 are performed using the operation buttons 14 of the operation panel section 17, etc. Therefore, even if the width of the printed circuit board 9 changes, the nozzles 26, 26, 26 set in the nozzle fixing frame 54 will not change. In addition, the position can be adjusted so that it is always centered on the printed circuit board 9.

The position of the nozzle fixing frame 54 can be adjusted by pressing the operation button 1.
Instead of the manual adjustment according to No. 4, it is also possible to perform automatic adjustment by driving and controlling the motor 59 using the set position of the nozzle fixing frame 54 determined by calculation as a target value, and controlling the positioning of the nozzle fixing frame 54.

By the way, in the conveyance path 22, the nozzles 26, 26.2
At approximately the same position as 6, an optical sensor (not shown) is provided to detect the arrival and completion of the printed circuit board 9. This optical sensor is activated when the tip of the printed circuit board 9 being conveyed blocks the light, and starts ejecting flux from the nozzle 26° 26.26. The flux jet is bent while passing through the printed circuit board 9, and when the trailing end passes the optical sensor, the projected light is detected again and the nozzles 26, 26 .
The flux injection from 26 is stopped.

Next, the operation of the flux coating device configured as described above will be explained.

The printed circuit board 9 is transferred to the transfer chain conveyor 43 on the entrance side.
．． 43', the receiver is passed to the conveyor chain 10, 10', and the opposing locking grooves 4 of the supporting pieces 11, 11...
When the tip of the printed circuit board 9 reaches the intermediate position of the conveyance path 22, which is sandwiched between the nozzles 26, 26, 26 and carried into the flux coating machine 1, the optical sensor is activated. Detecting this, the nozzle 26°26
．． 26 is activated and the flux is sprayed in a mist.

The flux from each nozzle 26, 26.26 spreads radially and is applied to the printed circuit board 9. At this time, as the flux spreads radially, the amount of flux in the outer peripheral area of the coated surface is smaller than in the inner central area, but the outer peripheral area of the flux from the adjacent nozzle overlaps with this outer peripheral area, and the amount of flux increases. There is no major imbalance,
The flux can be evenly applied to the lower surface of the printed circuit board 9 in a thin and uniform thickness. The printed circuit board 9 is conveyed to the exit side while flux is applied to the lower surface of the printed circuit board 9. When the rear end of the printed circuit board 9 finally reaches a state where it passes through the nozzle 26, an optical sensor detects this and the nozzle 26
Stop flux injection from. - side, dust collector 63
When operated, air above the conveyance path 22 is sucked inside the flux coating machine 1 by the suction fan 1. Therefore.

When the printed circuit board 9 is passing through the conveyance path 22 and the flux is being sprayed from the nozzle 26, the excess flux after being sprayed onto the printed circuit board 9 is sucked out by this suction air. In other words, there is no room for excess flux to adhere to the surface of the substrate 9, and it is collected by the filter of the dust collector 63 via the collection hood 23 and the exhaust duct 61, and is pulverized by a part of the filter. . Once the appropriate amount of powdered flux has been accumulated, the dust case can be removed from the dust collector 63 and thrown away.Then, the printed circuit board 9 that has been coated is transferred to the conveyor chain 10.
Transfer chain conveyor 43.4 on the exit side from ゜lO′
3, and then sent to the next process, the soldering process. Here, when the printed circuit board 9 comes out from the flux applicator 1, it is in a slightly diagonally upward position, and it advances to the primary solder tank in that position, so that it can be soldered well. In this way, by spraying flux in the form of a mist toward the bottom surface of the printed circuit board and sucking air above the printed circuit board, it is possible to apply the flux uniformly and thinly to the board. This prevents flux from entering or adhering to the surface.

If the flux can be applied thinly and uniformly, the next step, soldering, can be carried out well, and the flux will not completely melt into the solder, so cleaning the board to remove the flux can be omitted. can. Currently, the amount of flux applied.

The substrate is cleaned with fluorocarbons, but eliminating the need for fluorocarbon cleaning can be an effective measure to prevent the environmental destruction caused by the use of fluorocarbons, which is a problem today.

If the width of the printed circuit board 9 changes, by operating the rotation handle 13 and rotating the rotation shafts 48, 48,
The transport chain 10' is moved to adjust the transport path width. Accordingly, the operation button 14 for advancing or retracting the nozzle on the operation panel section 17 is pressed to drive the motor 59, and the nozzle fixing frame 54 is moved through the drive rod 60 and the frame body 57.
Move the nozzles 26, 2 to the center position of the printed circuit board 9.
6. Adjust the settings so that 26 is located.

At this time, if necessary, by adjusting the mounting position of each nozzle 26, 26, 26 to make the nozzle spacing appropriate, the flux can be more uniformly applied. Furthermore, depending on the viscosity of the flux used.

The height position of the nozzles 26, 26, 26 is changed using the vertical adjustment screw 56, and the amount of flux applied is adjusted to obtain an appropriate thickness.

Also, when applying flux to the printed circuit board 9, the locking grooves 4 of the support pieces 11, 11, . . .
2, 42..., but this is automatically cleaned with alcohol and rotating brushes 46, 46. Furthermore, the entrance side of the conveyor chain 10.10',
Transfer chain conveyors 43.4 each arranged on the exit side
3' is the mounting screw 6 in the adjustment slot 64, 64...
By moving 5.65..., the length can be freely adjusted back and forth, and communication with the conveyance means on the other side can be reliably established.

In the above embodiment, an example was shown in which the position of each nozzle 26, 26.26 was manually adjusted, but it is also possible to automatically adjust the position using a simple configuration.

FIG. 11 is a configuration diagram showing one example, showing only the nozzle mounting mechanism.

As shown in this figure, three threaded rods 70 are rotatably arranged in parallel in the horizontal direction on the nozzle fixing frame 54, and the nozzle 26 is attached to each of these threaded rods 70. At this time, it goes without saying that the part of the attachment part 26' of the nozzle 26 to be attached to the threaded rod 70 is threaded and screwed into the threaded rod 70.

At the tip of the screw stud 70 protruding from the side wall of the fixed frame 54,
A toothed ring whose circumferential surface is rotatable is provided, and an electromagnetic clutch 71 is provided so that the toothed ring and the end shaft of the threaded rod 70 are clutch-coupled. It meshes with the toothed ring on the circumferential surface of the electromagnetic clutch 71 to wind the toothed belt 72. At this time, the toothed belt 72 is
Toothed rings of three electromagnetic clutches 71 and pulse motor 7
The gear 74 fixed to the output shaft of No. 3 rotates at the same time.

Of course, instead of using the toothed belt 72, a gear mechanism may be used to transmit the rotation of the gear 74 to the toothed ring of each electromagnetic clutch 71.

With this configuration, the latch ON signal C1-03 is selectively applied to each electromagnetic clutch 71, and the nozzle 26 is moved to the target distance from the home position shown in the figure to the desired position. By applying a corresponding number of pulse signals S, each nozzle 26 can be automatically set at a desired position.

(G) Effects of the Invention As described above, the flux coating device of the present invention is provided with a plurality of nozzles that spray flux in a bag shape at an appropriate position below the conveyance path for conveying printed circuit boards. Air is sucked above the road, excess flux is collected together with the sucked air by a collection hood, and is then led to a dust collector via an exhaust duct. Therefore, with this configuration,
Flux can be applied evenly and thinly to printed circuit boards.

Since problems such as areas where the flux is not applied or the flux being applied too thick do not occur, reliable soldering can be achieved in the first soldering process.

- Excess flux is removed from the printed circuit board and pulverized by a dust collector, so there is no risk of contaminating the surrounding environment.Furthermore, the flux can be applied evenly and thinly, and excess flux is eliminated. By being able to
This makes it possible to omit the need to clean the substrate with fluorocarbons after applying flux, greatly contributing to the elimination of the use of fluorocarbons, which has become a problem in recent years for environmental protection, and has great industrial value.

In particular, even if the width of the printed circuit board changes, just by sliding the nozzle, the nozzle spacing can be changed appropriately.
The flux is reliably applied over the entire surface of the printed circuit board, and any size of printed circuit board can be coated, making it highly mass-producible and versatile. In addition, by moving the nozzle up and down, it is easy to adjust the thickness of the flux layer according to the properties of the applied flux.Furthermore, since the nozzle can be moved so that it is always centered on the printed circuit board, the flux is uniform. It has the effect of being able to completely apply a very thin film.

[Brief explanation of drawings]

Fig. 1 is a front view of the configuration of the flux coating device of the present invention, which is composed of a flux coating machine, a duct for discharging surplus flux after coating, and a dust collector for collecting and pulverizing surplus flux. External perspective view of coating machine,
Fig. 3 is a side view schematically showing the main internal components of the flux coating machine, Fig. 4 is a plan view of the main parts of the flux coating machine mainly showing the printed circuit board conveying chain and the flux injection nozzle, and Fig. 5 The figure is a plan view of the main parts of the flux coating machine, mainly showing the driving force section of the conveyor chain for printed circuit boards and the variable width mechanism of the conveyor chain. Figure 6 is a side cross-section of the main parts in the direction of the ^-A arrow in Fig. 4. 7 is a partial sectional view of a conveyor chain to which rotational power is transmitted from a sprocket gear, FIG. 8 is an external perspective view of the conveyor chain, and FIG. 9 is a chain provided at the front end of the conveyor chain that extends forward and backward. Fig. 10 is a plan view of the arrangement of the flux coating device, and Fig. 11 is a configuration diagram of the nozzle mounting mechanism that enables automatic adjustment of the nozzle position. . 1...Flux coating machine, 9...Printed circuit board, 1
0.10'... Conveyance chain, 11... Support piece, 1
3... Rotating handle, 22... Conveyance path, 23...
Collection hood, 26... nozzle, 28... fixing screw,
29... Spline shaft, 33... Sprocket, 3
1.31', 38.38'...Rotation axis, 34,
34... Rotation shaft, 42... Support piece locking groove, 43,
43'... Transfer chain conveyor, 48... Motor, 54... Nozzle fixing part, 59... Motor, 60...
... Drive rod, 61... Exhaust duct. 63... Dust collector. Figure 2 Figure 7 Figure 0 4 Figure 0 Figure 1

Claims (2)

[Claims] (1) A plurality of nozzles that spray atomized flux onto the lower surface of a printed circuit board that is conveyed in a substantially horizontal direction by a conveyance means with a variable conveyance path width, a nozzle support that supports these nozzles, and the conveyor. A flux applicator comprising a surplus flux discharging means for collecting surplus flux by air sucked above the road and discharging it to the outside; and a dust collector for processing the discharged surplus flux into powder; The nozzles supported by the body are slidable and arranged side by side in the width direction of the conveyance path, and are configured to be able to rise and fall slightly up and down, and are arranged so that the nozzles are positioned at the center according to the width of the printed circuit board. A flux coating device characterized in that the support is configured to be movable as a whole. (2) Printed circuit board transport equipped with a holding claw circulating body in which two rows of holding claws that hold the printed circuit board on both sides are arranged in parallel at variable intervals, in which a plurality of holding claws circulate in synchronization along the printed circuit board transport path. a mechanism, a plurality of nozzles that are arranged below the printed circuit board in the middle of the printed circuit board conveyance in this printed circuit board conveyance mechanism and spray atomized flux onto the lower surface of the conveyed printed circuit board; A plurality of threaded rods are screwed together and supported movably in the road width direction, a nozzle fixing frame that rotatably holds these threaded rods, a pulse motor, and the rotational force of the pulse motor is transmitted from the side wall of the nozzle fixing frame. a power transmission mechanism that selectively transmits power to the tips of each of the protruding threaded rods; a movement mechanism that integrally moves the nozzle fixing frame, the power transmission mechanism, and the pulse motor up and down; A flux application device comprising: a surplus flux discharge device that collects surplus flux and discharges it to the outside; and a flux recovery device that pulverizes and recovers the discharged surplus flux.