JPH09239300A - Spray type flux coating apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the flow velocity of a mist like flux from lowering at the corner parts of both side end parts of the wiring board formed by a cover preventing the scattering of mist like flux and a wiring board. SOLUTION: The scattering preventing cover 27 preventing the bonding of the mist like flux 8 sprayed from a spray nozzle 7 to a part other than a wiring board 1 is provided so as to conceal the part of a feed conveyor 6 provided to the spray region of the flux 8 when looked from the spray nozzle 7 and a bypass passage 29 for allowing the flux 8 sprayed in a mist form to flow out to the outside of the scattering preventing cover 27 is provided to the scattering preventing cover 27 to make it possible to uniformly apply the flux 8 to the corner parts of both side end parts 1a of the wiring board 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spray type flux applicator for spraying and applying flux onto a plate-like work such as a wiring board on which electronic parts are mounted.

[0002]

2. Description of the Related Art A spray-type flux coating device is capable of thinly and uniformly coating flux on a flux coating work such as a wiring board, and has an excellent controllability of the coating amount.

FIG. 4 is a perspective view showing main components of a conventionally used spray type flux coating apparatus, showing a carrier system 2 of a wiring board 1 and a flux spray system 3. That is, the parallel double-sided conveyor belt 4 or the conveyor chain 5
The side end portions 1a of the wiring board 1 are placed and supported on a carrying conveyor 6 made up of and carried, and the spray nozzle 7 arranged on the lower side of the wiring board 1 (on the side to which the flux is applied) transfers the wiring board 1 to the wiring board 1.
Flux 8 is sprayed onto the coated surface of
This is a mechanism in which the flux 8 is applied to the surface and applied.

In the spray type flux applicator illustrated in FIG. 4, the flux 8 is sprayed while the spray nozzle 7 is reciprocally moved in a direction orthogonal to the transfer direction A of the wiring board 1 by a swing device such as a reciprocator 9. (The substantial sprayed area has an elliptical shape as shown by a broken line) It is a device of a mechanism for applying and applying to the wiring substrate 1, and the uniformity of application is remarkably excellent.

The transfer conveyor 6 has a drive motor 10
And the drive shaft 11, the drive pulley (in the case of the conveyor belt 4) 12, or the drive sprocket (the conveyor chain 5)
13), a driven pulley 14 and a driven sprocket 15 for tensioning the conveyor belt 4 or the conveyor chain 5, and the conveyor belt 4 or the conveyor chain 5 is driven to rotate.

FIGS. 5 (a) and 5 (b) are views showing a main part of a traveling system of the transfer conveyor 6 and a support mechanism of the wiring board 1.
It is the perspective view which looked at the cross section by the II line of FIG. 4 from the diagonal direction. 5A shows the case of the conveyer conveyor 6 constituted by the conveyer belt 4, and FIG. 5B shows the case of the conveyer conveyor 6 constituted by the conveyer chain 5.

That is, the conveyor belt 4 shown in FIG.
In the case of, the side end portion 1a of the wiring board 1 is placed on and supported by the conveyance belt 4 which is guided by the guide rails 21 and is conveyed, and the board guide 22 is provided on both side end portions 1a of the wiring board 1. It is a member that regulates the position and realizes stable straight traveling.

In the case of the transport chain 5 shown in FIG. 5 (b), the side end portion 1a of the wiring board 1 is placed on and supported by the pin 24 of the transport chain 5 guided by the guide rails 23 and transported. The guide plate 25 is a member for restricting the positions of both side end portions 1a of the wiring board 1 to realize stable linear conveyance.

Incidentally, there is an advantage that the vertical dimension L ₁ of the transport conveyor 6 when the transport belt 4 is used can be made smaller than the vertical dimension L ₂ of the transport conveyor 6 when the transport chain 5 is used. This can reduce the hide zone when the wiring substrate 1 is viewed from the spray nozzle 7 in the spray-type flux coating device, so that the portion where the wiring substrate 1 is placed on the conveyor belt 4 can be reduced. It has an advantage that the sprayed flux 8 can be spread evenly to the corners and the flux 8 can be applied uniformly.

FIG. 6 is a side sectional view showing a conventional exhaust system of a spray type flux coating device, and the same reference numerals as those in FIG. 4 denote the same parts. That is, an exhaust hood 26 as an exhaust means is provided at a position facing the spray nozzle 7 with the transport conveyor 6 interposed therebetween, and exhaust is performed by an atmosphere intake means such as a blower (not shown), and the exhaust hood 26 is applied to the wiring board 1.・ It is a mechanism to inhale and discharge the floating mist-like flux 8 that has not been applied. Further, in order to prevent the floating flux 8 that has been applied / not applied to the wiring board 1 from adhering to the transfer conveyor 6, a scattering prevention cover 27 is provided so as to shield the spray nozzle 7 side of the transfer conveyor 6. There is.

FIG. 7 is a perspective view showing the whole of the shatterproof cover 27 of FIG. Further, FIG. 8 shows the scattering prevention cover 2
7 and the arrangement structure of the exhaust hood 26.
It is an end view seen from the II-II line.

That is, the scattering prevention cover 27 is arranged so as to cover the bottom surface and the side surface of the transfer conveyor 6, and the mist-like flux 8 sprayed from the spray nozzle 7 does not adhere to the transfer conveyor 6 and the wiring board. The floating mist-like flux 8 that is applied / applied to 1 and is not applied / applied is exhausted together with the surrounding atmosphere by the exhaust hood 26. The accumulation portion 28 of the scattering prevention cover 27 is for accumulating the flux 8 attached to the scattering prevention cover 27 and flowing down (this is a very small amount).

[0013]

The scattering prevention cover 27 is essential in order to shield the transport conveyor 6 from the sprayed flux 8 and prevent the adhesion of the flux 8.
If this is not done, the flux 8 adheres and accumulates on the conveyor belt 4, the conveyor chain 5 and the guide rail 21,
This is because the flux 8 adheres to and contaminates the wiring board 1 that is transported via the transport belt 4 and the transport chain 5, and the traveling stability of the transport belt 4 and the transport chain 5 deteriorates.

However, at the corners 100 (shown by ellipses in FIGS. 6 and 7) indicated by the circles in FIGS. 6 to 8, when the wiring board 1 is transported to the upper part of the scattering prevention cover 27, the scattering occurs. Since the flux 8 ejected from the spray nozzle 7 and sprayed by the presence of the prevention cover 27 flows as shown by the arrow in FIG. 6, the flow velocity of the flux 8 is relatively reduced as compared with other portions, and the corner portion The side end portion 1a of the wiring board 1 shown by 100
The amount of flux applied and the amount of flux will be small but small. The extent to which the flux coating / coating is reduced is a very small portion of the corner 100, which is less than several mm, but in a high-density mounting board in which components are mounted up to the side end 1a of the wiring board 1. In some cases, it may be difficult to obtain uniform solderability in the subsequent step in the soldering step (the wiring board 1 carrying direction A).
If the length is long). In addition, the floating flux 8 having a low flow velocity easily adheres to the scattering prevention cover 27 before the exhaust hood 26 sucks the flux 8.

An object of the present invention is to realize a spray-type flux coating device capable of uniformly coating flux on every corner of a plate-like work such as a wiring board, and to provide a high quality wiring board. To be able to manufacture.

[0016]

The spray-type flux coating apparatus of the present invention prevents the flow rate of the spray flux at both end portions of a plate-like work from decreasing and causes the spray flux to flow out of the scattering prevention cover. A bypass passage is provided for the purpose. Further, it is characterized in that the atomized flux floating on the work without being applied or applied is exhausted by the exhaust means.

[0017]

According to each claim, there are the following actions.

(1) In the invention described in claim 1, since the spray flux flows out from the corner formed between the scattering prevention cover and the plate-shaped work (wiring board) through the bypass passage, The spray flux spreads at the corners without decreasing the flow velocity, and the flux is applied and evenly applied to every corner of the plate-like work. Moreover, the flux does not adhere to unnecessary portions.

(2) According to the second aspect of the present invention, by directing the outlet / outlet of the bypass passage to the exhaust means, the atomized flux flowing out from the bypass passage is directly sucked into the exhaust means and discharged. Further, the intake air of the exhaust means allows the atmosphere to positively flow out from the corners formed between the scattering prevention cover and the plate-like work, so that the flux can be evenly applied to every corner of the plate-like work. Will be able to. Further, the adhesion of flux to unnecessary portions is further eliminated.

[0020]

EXAMPLES Next, examples of practical application of the spray type flux coating apparatus according to the present invention will be described.

FIG. 1 is a sectional view showing an embodiment of the present invention and corresponds to the sectional view of the conventional apparatus shown in FIG. 2 is a perspective view showing the entire shape of the shatterproof cover of FIG. 1, and corresponds to the perspective view of FIG. 7 of the conventional device. Note that FIG. 1 illustrates an example in which the conveyor belt 4 is used for the conveyor 6.

That is, the wiring board 1 and the scattering prevention cover 2
A bypass passage 29 is provided in the vicinity of a corner formed between the bypass conveyor 29 and the conveyer 6 so as to avoid the conveyer conveyor 6. It is provided toward 26.

As a result, the flux 8 sprayed from the spray nozzle 7 can flow out through the bypass passage 29, and the flow velocity of the spray flux 8 does not decrease at the corner portion 100 indicated by the circle, without any decrease. The flux 8 is evenly applied / applied to the side end 1a of the wiring board 1 of the portion 100. Further, since the floating flux 8 is immediately guided to the exhaust hood 26 through the bypass passage 29, the scattering prevention cover 27, the conveyor belt 4,
The flux 8 does not adhere to the portion of the transport chain 5 or the like shown in FIG. 3 where the adhesion of the flux is not originally required.

Incidentally, by adjusting the size of the outlet 30 of the bypass passage 29 and the position with the exhaust hood 26 to adjust the intake flow rate, the atmospheric flow rate at the corner 100 and the spray flow rate of the air ejected from the spray nozzle 7 are adjusted. It is also possible to adjust the equilibrium with.

Further, the bypass passage 29 is connected to an intake means such as a blower provided in a duct or the like, and the rotation speed of the blower is adjusted by the speed adjusting means to adjust the intake flow rate, and the outflow from the corner portion 100. By adjusting the atmosphere flow rate to be adjusted, it is possible to adjust the equilibrium between the atmosphere flow rate in the corner portion 100 and the spray flow rate of the air ejected from the spray nozzle 7.

FIG. 3 is a sectional view showing another embodiment of the present invention, and the same reference numerals as those in FIG. 1 indicate the same parts. That is, it is a diagram showing an example in which the transport chain 5 is used for the transport conveyor 6.

The transport chain 5 may be used in the same manner as in the example of FIG. 1, but the guide rail 23 is provided with a hole 31 through which the bypass passage 29 can pass, as shown in FIG. Can be configured. That is, by providing the bypass passage 29 as close to the wiring board 1 as possible, the corner portion 10 of the wiring board 1 is provided.
The flux 8 can be evenly applied and applied to 0.

The operation is the same as that when the conveyor belt 4 is used for the conveyor 6 in FIG.

[0029]

As described above, according to the present invention, there are the following effects corresponding to each claim.

According to the first aspect of the present invention, the flux can be evenly applied to the corners of a plate-like work such as a wiring board where the flux is hard to adhere. Uniform solderability can be obtained, and a high-quality wiring board or the like can be manufactured. In addition, the flux does not adhere to unnecessary parts such as the conveyer, and a clean flux application environment can be realized.

According to the spray flux coating device of the second aspect, the effect described in the first aspect can be further enhanced.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a perspective view showing the overall shape of the shatterproof cover of FIG.

FIG. 3 is a sectional view showing another embodiment of the present invention.

FIG. 4 is a perspective view showing main components of a conventionally used spray type flux coating device.

5 is a perspective view of a cross section taken along the line I-I of FIG. 4 as seen from an oblique direction, FIG. 5 (a) shows a case of a conveyer conveyor constituted by a conveyer belt, and FIG. 5 (b) is a conveyer chain. The case of a transfer conveyor configured by is shown.

FIG. 6 is a side sectional view showing a conventional exhaust system of a spray type flux coating device.

7 is a perspective view showing the overall shape of the shatterproof cover of FIG.

FIG. 8 is an end view taken along the line II-II in FIG.

[Explanation of symbols]

 1 Wiring Board 1a Side End 4 Conveyor Belt 5 Conveyor Chain 6 Conveyor 7 Spray Nozzle 8 Flux 9 Reciprocator 21 Guide Rail 23 Guide Rail 26 Exhaust Hood 27 Scatter Prevention Cover 29 Bypass Passage 30 Outlet 31 Hole 100 Corner

Claims (2)

[Claims] 1. A spray-type flux coating apparatus for supporting and transporting a plate-shaped work by a transport conveyor, spraying flux from a spray nozzle facing the work to coat and apply the flux to the work, A scattering prevention cover that prevents the flux sprayed from the spray nozzle from adhering to a portion other than the work is provided so that at least the transfer conveyor portion in the spray area as viewed from the spray nozzle is hidden.
The spray-type flux applying device, wherein the spray-preventing cover is provided with a bypass passage for flowing the sprayed flux to the outside of the scattering-preventing cover. 2. The spray-type flux coating device according to claim 1, further comprising an exhaust unit for discharging the flux, which is floating without being applied or applied to the work, out of the sprayed flux, and the bypass. A spray-type flux coating device, characterized in that an outlet / outlet of a passage is provided toward an exhaust means.