JPH0946032A - Mounting apparatus for electronic component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mounting apparatus for electronic components having a spray-type flux applying device, which prevents the contamination of the mechanism part of the carrier device and the like by the flux scattered by a spray without cleaning, can securely supply the required flux into a small- diameter through hole and can perform highly reliable solder connection. SOLUTION: A pair of covers 22 and 15 are arranged at the upper side and lower side of an electronic circuit board 1. Thus, the space around the electronic circuit board 1 is closed, so that the enclosed structure is obtained. A screening plate 14 is provided at the opening part of the lower cover 15 having a lift device 20, and the gap formed between a carrier jig 3 and the board 1 is closed with the screening plate. Flux is sprayed and applied from the rear surface of the board 1 by a spray device 6 provided in the lower cover 15. At this time, the space in the upper cover 22 is made to be a negative- pressure state with a suction duct 23. The flux is led to the level at the upper end of the through hole of the electronic circuit board 1 and applied in the entire through hole.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic component mounting apparatus, and more particularly, to a spray type flux applying apparatus used for soldering after mounting and assembling electronic components on an electronic circuit board. The present invention relates to a mounting device for electronic components.

[0002]

2. Description of the Related Art In order to eliminate environmental problems caused by CFC cleaning, non-cleaning of flux is being studied as an important issue in the soldering technology for electronic circuit boards. In order to realize this non-cleaning, it is very effective to reduce the adhered amount of flux as much as possible, but as a means to do so, the conventional foaming method in which the flux is made into bubbles and jetted and applied to the electronic circuit board is used. Instead of the formula-based flux application, a spray method is adopted in which flux can be sprayed from a spray nozzle and applied evenly and thinly.

FIG. 2 shows an outline of a conventional flux spray coating device. The situation in which the flux 7 atomized by the spray device 6 is applied to the back surface of the electronic circuit board 1 is shown. As shown in the figure, the structure is such that the scattered flux adheres not only to the back surface of the substrate 1 but also to the conveyer conveyor 4, the conveyer jig 3, and the like. There was a lot of work to do.

As a flux coating device for atomizing and spraying this kind of flux with a spray nozzle, for example, JP-A-6-224546, JP-A-6-77634, and JP-A-6-97639. The gazette etc. are mentioned.

[0005]

In the above-mentioned conventional spray-type flux applying method, since the flux is made into a fine mist and jetted onto the component surface of the electronic circuit board, the flux scattered by the bounce or the like is conveyed inside the apparatus. Since it adheres to the mechanical part and the like and the device cannot operate normally, it was necessary to frequently clean the device to remove the flux.

Further, in the current spray method, only droplets of flux adhere to only the surface of the electronic circuit board of the electronic circuit board, and the atomized flux is present in the through holes into which the leads of the electronic parts are inserted. However, there is a problem that it is difficult to obtain a good soldering quality in the subsequent soldering. This problem is becoming more serious as the density of electronic circuit boards is increased and the diameter of through holes is reduced.

Therefore, an object of the present invention is to solve the above-mentioned problems of the prior art. Specifically, it prevents contamination of the transport mechanism and the like to eliminate the need for cleaning, and further reduces the diameter of the through hole. Another object of the present invention is to provide an electronic component mounting apparatus that can reliably supply the necessary flux into the through holes and realize good solder connection.

[0008]

Means for Solving the Problems The above-mentioned object is to convey and position an electronic circuit board held by a conveying jig to a predetermined position where a flux coating device is arranged by a conveyor, and the conveyed electronic circuit board. A mounting device for electronic components, comprising: a flux coating device that spray-coats flux from the back surface of a circuit board.
There is a built-in spray device that can move the nozzle position arbitrarily, and a shielding plate that surrounds the periphery of the electronic circuit board held by the conveyor jig on the conveyor is installed in the upper opening in front and back according to the size of the electronic circuit board. A cover is provided slidably, and a cover moving mechanism that raises and lowers the cover is configured to be atomized by raising the cover during spray application and closing the space around the electronic circuit board. This is achieved by an electronic component mounting device configured to prevent the generated flux from being scattered to the device mechanism part.

[0009] More preferably, the cover is a lower cover, and an upper cover having a suction duct on the upper side thereof is also arranged via the transfer jig to close the upper space of the transfer jig with the upper cover. The structure is such that the space inside the upper cover is kept in a negative pressure state during spray application, and atomized flux is guided into the through holes of the electronic circuit board. This allows flux to be easily drawn into the through hole based on the pressure difference between the front and back surfaces of the through hole, even when the leads of electronic components are inserted into the through hole, enabling reliable and good solder connection. And

The upper cover having the suction duct includes
An exhaust pump is provided to keep the inner space of the upper cover in a negative pressure state. Also, the upper cover is provided with a cover moving mechanism that moves up and down similarly to the lower cover, and lowers when the electronic circuit board is conveyed to the position of the flux coating device by the conveyor, and rises when coating is completed. However, it may be configured to facilitate the movement of the transfer jig to the soldering device.

Further, an air-impermeable elastic body frame, for example, a rubber skirt is arranged in the opening of the upper cover so as to maintain the airtightness between the conveying jig and the opening of the upper cover. You can also In this case, it is possible to omit the installation of a cover moving mechanism for moving the upper cover up and down, and for example, the rubber skirt may be fixed at a height at which it always contacts the carrying jig.

Before and after the flux applying device, a device for inserting leads of electronic parts into the through holes of the electronic circuit board and a soldering device are provided, which makes it possible to carry out electronic parts consistently from component insertion to solder connection. Mounting device is realized.

[0013]

According to the flux spray coating device constructed as described above, the flux is prevented from entering the mechanism portion of the device, the stable operation of the device is achieved, and the maintainability is improved. Further, it becomes possible to apply a uniform flux to the inner wall of the through hole of the electronic circuit board, which has the effect of improving the soldering quality.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be specifically described below with reference to the drawings. <Embodiment 1> FIG. 1 shows a mounting process diagram by flow soldering according to the present invention. In the step of soldering the electronic circuit board 1 in the figure, first, the electronic circuit board 1 is attached to the board transfer jig 3 in the board attaching / detaching step 2,
It is sent to the flux applying step 5 by the upper transfer conveyor 4. Then, the flux 7 is discharged from the spray device 6, and the flux is applied to the back surface of the substrate 1.

Electronic circuit board 1 coated with flux
Is transported to the flow soldering step 8 by the transport conveyor 4, and the board 1 passes over the jet solder bath 9 for soldering. Electronic circuit board 1 after soldering
Is transported from the lifter device 10 to the lifter device 12 through the return conveyor 11, returned to the substrate mounting / removing process 2 and the soldered substrate 1 is taken out from the transport jig 3.

FIG. 3 (a) is a plan perspective view showing a flux shielding structure according to an embodiment of the present invention, and FIG. 3 (b).
FIG. 3 is a sectional view taken along line AA ′ of FIG. That is, FIG.
(A) shows a state in which the gaps formed between the transfer jig 3 and the substrate 1 are closed by using the shielding plates 14a and 14b so that the atomized flux 7 is not scattered on the upper surface of the electronic circuit substrate 1. Is shown. Reference numeral 3a in the figure denotes a protrusion supported by a conveyor 4 provided on the transfer jig 3.

As is apparent from FIG. 3B, the shielding plates 14a and 14b are attached to the slit groove 16 provided in the upper opening of the lower cover 15. That is, the slit groove 16 is formed by two shield plates 14 that are orthogonal to each other.
Corresponding to a and 14b, they are provided in the opening of the lower cover 15, respectively. By sliding the shielding plate in the groove according to the size of the electronic circuit board 1, its mounting position can be freely changed.

In this method of fixing the shield plate 14, the spring pin 17 is provided in the lower cover 15, and when the shield plate 14 is inserted into the slit groove 16, the spring pin 17 is fitted in the mounting hole 18 provided in the shield plate 14. By putting in
The position can be changed and fixed easily. In addition, instead of fixing the shield plate with the spring pin 17,
For example, a spring may be provided at one end of the groove to press the shield plate 14 to adjust the mounting position steplessly.

Further, since the electronic circuit board 1 generally has a large number of external sizes, in order to accommodate this, the transfer jig 3 is moved so that the mounting position can be adjusted steplessly. Possible substrate holding claws 19a, 19b are provided.

Lower cover 15 with shield 14 attached
Is moved up and down by an elevating device 20 (a configuration in which an elevating cylinder is moved up and down by a hydraulic mechanism) connected to a collar-shaped projection 31 provided on the outer wall of the conveyor jig 3. When I got to the fixed position,
Ascends to a position where the carrier jig 3 comes into close contact with the back surface of the frame.

As a result, the space below the electronic circuit board 1 is a space closed by the board 1, the shielding plate 14, and the lower cover 15, and when the flux 7 is discharged from the spray device 6, the fog is generated. It is possible to prevent the flux that is formed into a floating state and the flux that is scattered by splashing from entering the upper surface of the substrate 1, the transport conveyor 4, the transport jig 3, and the like. The lower end of the lower cover 15 is open,
A flux tray 21 is placed and arranged so as to prevent the flux attached to the inner wall of the lower cover 15 from flowing down. The shielding plate 14 and the lower cover 15 were made of stainless steel plate.

<Embodiment 2> FIG. 4 is a cross-sectional view of an essential part showing another embodiment of the present invention, in which a cover (upper cover 22) is also installed on the upper side of the transfer jig 3 of FIG. A suction duct 23 connected to an exhaust pump (not shown) is attached to the upper cover 22. The upper cover 22 is fixed to the apparatus housing 24 so that the upper cover 22 is located right above the transport jig 3 when the transport jig 3 is transported on the conveyor 4 and reaches the position of the coating device. At this time, since a gap is created between the upper cover 22 and the transport jig 3, a rubber-like skirt 25 is attached to the opening of the upper cover 22 to close the gap.

As a result, the space above the electronic circuit board 1 is closed by the board 1, the shielding plate 14 and the upper cover 22. At this time, air is constantly sucked from the suction duct 23, and the space above the substrate 1 gradually becomes a negative pressure state. When the space above the substrate 1 is in a negative pressure state, when the flux is ejected to the lower surface of the substrate 1 by the spray device 6, the atomized flux 7 becomes an electronic component as shown in the sectional view of the main part of FIG. 26 is guided to the hole of the through hole 27 into which the lead 26a of 26 is inserted,
The flux can be sufficiently penetrated into the through holes 27, and as a result, good quality soldering can be performed.

FIG. 6 is a fragmentary perspective view of a flux coating apparatus for forming a vertically closed space of the electronic circuit board 1 of the present invention and spray-coating the flux. In this flux applying apparatus, every time the outer size of the electronic circuit board 1 changes, the setup operation of the mechanical parts at three locations is performed in accordance with the change. One is the lower cover 1
The position of the nozzle is adjusted by adjusting the mounting position of the shield plate 14 attached to the nozzle 5 and operating the centering mechanism 28 so that the spray device 6 is aligned with one axis center of the substrate 1. Further, since the spray device 6 applies the flux while moving the nozzle along the other axis according to the substrate size, it is necessary to adjust the slide distance of the slide drive unit 29.

After the above-mentioned setup work, the electronic circuit board 1 is held by the board holding claws 19a and 19b of the carrying jig 3 and carried on the carrying conveyor 4 in the arrow direction.
When the carrying jig 3 arrives at the flux applying section, it is stopped at a fixed position by the stopper 30. Since the air is constantly sucked from the suction duct 23, the space on the side of the upper cover 22 gradually becomes a negative pressure state.

The lower cover 15 is provided after the transport jig 3 arrives.
It is lifted by the lifting cylinder 20 and pressed against the lower surface of the transfer jig 3 to form a closed space. After the space on the side of the lower cover 15 is closed, the spray device 6 starts discharging the flux and sprays the flux while moving from the front to the rear of the electronic circuit board 1 by the slide mechanism unit 29. After the application of the flux is completed, the spray device 6 and the lower cover 14 are returned to their original positions, the stopper 30 that has stopped the transfer jig 3 is released, and the transfer jig 3 is transferred to the next soldering step. To be done.

As a result, the flux is drawn into the through holes of the electronic circuit board 1 and uniformly applied, thereby ensuring the solder connection. Further, even if the flux is sprayed, the upper and lower covers 22 and 21 do not scatter to the outside and block the flux, so that cleaning of the device is not necessary. In addition, the flux collected in the flux tray is reused.

The negative pressure state of the upper cover inner space at the time of applying the flux is performed by adjusting the exhaust amount of the exhaust pump connected to the suction duct, but preferably the flux is in the through holes of the electronic circuit board 1. It is a negative pressure state that is sucked up to the level of the upper end, and it is desirable that the pressure is not reduced so much that it overflows to the surface of the electronic circuit board.

[0029]

As described above in detail, according to the present invention, the intended purpose can be achieved. That is, by providing the flux coating device of the present invention, the spray-coated flux adheres only to the back surface of the electronic circuit board and the shield plate and the inner wall of the cover installed below, so that the flux or mist that scatters when hitting the board. Floating flux, etc. will not infiltrate into the mechanical parts such as the board transfer jig and the transfer conveyor, and the frequency of cleaning the mechanical parts, which was frequently done in the past, will be reduced, and maintenance work will be easier. The effect is obtained. Further, by sucking air in the closed space above the substrate, the flux is guided from the through hole into which the electronic component is inserted, and the permeability of the flux to the inner wall of the through hole is improved, thereby improving the This has the effect of providing soldering quality.

[Brief description of drawings]

FIG. 1 is a soldering process diagram for mounting an electronic component according to an embodiment of the present invention on an electronic circuit board.

FIG. 2 is a schematic view of a conventional flux spray coating device.

FIG. 3 is an explanatory diagram of a main part configuration of a flux spray coating device according to an embodiment of the present invention.

FIG. 4 is a sectional view of the essential parts of a flux spray coating apparatus according to another embodiment of the present invention.

FIG. 5 is a cross-sectional view of an electronic circuit board for explaining how flux is induced in a through hole of the electronic circuit board according to the present invention.

FIG. 6 is a partially cutaway perspective view of a flux spray coating device according to another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Electronic circuit board, 2 ... Electronic circuit board attaching / detaching process, 3 ... Electronic circuit board carrying jig, 4 ... Upper carrying conveyor, 5 ... Flux applying process, 6 ... Flux spraying device, 7 ... Flux, 8 ... Flow soldering Steps: 9 ... Jet solder bath, 10 ... Lifter device, 11 ... Return conveyor, 12 ... Lifter device, 13 ... Atomized flux, 14 ... Shielding plate, 15 ... Lower cover, 16 ... Shielding plate insertion slit groove, 17 ... Shielding plate positioning spring pin, 18 ... Shielding plate positioning hole, 19 ... Electronic circuit board holding claw, 20 ... Lower cover elevating device, 21 ... Flux pan, 22 ... Upper cover, 23 ... Air suction duct, 24 ... Flux applying device housing Body, 25 rubber skirt, 26 ... Electronic component, 27 ... Electronic component insertion hole (through hole), 28 ... Spray part sensor Mechanism, 29 ... spray unit slide drive unit, 30 ... substrate conveying jig stop 31 ... lower cover outer peripheral flange-shaped projecting mating.

Claims (6)

[Claims] 1. A means for carrying and positioning an electronic circuit board held by a carrying jig to a predetermined position where a flux coating device is arranged by a conveyor, and a flux is sprayed from the back surface of the carried electronic circuit board. An electronic component mounting apparatus comprising: a flux coating device for coating; a spraying device capable of arbitrarily moving the nozzle position of the flux coating device is built in; And a cover moving mechanism for moving the cover up and down, and a cover provided around the electronic circuit board held by the slide plate so as to be slidable back and forth according to the size of the electronic circuit board. , As a result, the cover rises during spray application and the space around the electronic circuit board is closed, and atomized flux is scattered to the mechanical parts of the device. Mounting apparatus of electronic components comprising the so as to prevent that. 2. A structure in which the cover is a lower cover, and an upper cover having a suction duct is provided above the cover via the transfer jig to close an upper space of the transfer jig with the upper cover. 2. The mounting apparatus for electronic components according to claim 1, wherein the space inside the upper cover is kept in a negative pressure state during spray application to guide atomized flux into the through holes of the electronic circuit board. 3. The upper cover having the suction duct includes:
3. The electronic component mounting apparatus according to claim 2, further comprising an exhaust pump that holds the space inside the upper cover in a negative pressure state. 4. The structure according to claim 2, wherein an air-impermeable elastic body frame is provided in the opening of the upper cover to maintain airtightness between the conveying jig and the opening of the upper cover. Electronic component mounting equipment. 5. An electronic component mounting apparatus according to claim 2, wherein the upper cover is provided with a cover moving mechanism for moving up and down. 6. The electronic component according to claim 1, further comprising a device for inserting leads of the electronic component into a through hole of an electronic circuit board and a soldering device before and after the flux applying device. Mounting device.