JP2636730B2 - Printed circuit board suction device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printed board suction apparatus for positioning a printed board by vacuum suction, and more particularly to a printed board suction apparatus suitable for positioning a printed board of a cream solder printing machine.

[0002]

2. Description of the Related Art Conventionally, when a cream solder is printed on a printed circuit board using a cream solder printing machine,
The back surface of the printed circuit board is held and positioned by vacuum suction using a printed circuit board suction device.
As a conventional printed board suction device, for example, in Japanese Patent Application Laid-Open No. Hei 1-209136, a board receiving pedestal having a printed board suction hole formed on the entire surface thereof and an air suction path connected to the board receiving pedestal. A vacuum pump that sucks air from the substrate and sucks the printed circuit board onto the board receiving table; and an outside air intake valve and a filter connected to the air suction path. A printed circuit board suction device has been proposed which removes unnecessary cream solder sucked from a through hole of the printed circuit board to a vacuum pump while adjusting the suction force.

However, if a suction hole is formed in the entire surface of the board receiving table as in the above-described printed board suction device, the divided grooves and through holes of the printed board overlap with the suction hole to cause air leakage. There is a problem that the suction force of other parts is reduced.

In view of the above, conventionally, a dedicated board receiving stand having a suction hole formed only at a position where no air leakage occurs according to the shape of a printed board on which cream solder is to be printed has been manufactured.
The printed circuit board was held effectively.

[0005]

However, in the above-described conventional printed board suction apparatus, a dedicated board receiving table corresponding to the shape of the printed board is used.
Each time the external dimensions, shape, and formation position of through holes, etc., of the printed circuit board to be printed are changed, the board support must be re-created, which requires a great deal of cost and time to manufacture a new board support. there were. In addition, every time the printed circuit board to be printed is changed, it is necessary to change the board receiving table, which causes a problem that the working efficiency is reduced.

In Japanese Utility Model Application Laid-Open No. 3-38700, a board support is formed by a plurality of suction blocks having suction holes formed therein, and these suction blocks are rearranged in accordance with the shape of the printed circuit board. There has been proposed a printed board suction device capable of holding printed boards of various shapes.
However, in this printed board suction apparatus, the suction blocks have to be rearranged every time the printed board is changed, and there is a problem that the working efficiency is reduced.

In Japanese Patent Application Laid-Open No. 3-101186, at the time of printing, the operation of the suction means at the position corresponding to the squeegee for printing the cream solder on the printed circuit board is stopped, and the cream solder is sucked from the through hole to the vacuum pump. There has been proposed a printed circuit board suction device capable of preventing the occurrence of the problem and improving the suction force of the printed circuit board. However, in this printed circuit board suction device, air leaks from divided grooves and through holes of a printed circuit board in a place where it is not compatible with a squeegee, and the problem that the suction force of the vacuum pump cannot be completely reduced cannot be eliminated. was there.

In Japanese Patent Publication No. 221942, unnecessary suction holes of the board holder are appropriately closed with a closing member so that a single board holder can hold printed boards of various shapes. There has been proposed a printed circuit board suction device capable of preventing a reduction in suction force of a vacuum pump. However, in this printed circuit board suction device, it is not possible to automatically select and close unnecessary suction holes, and when the shape of the printed circuit board changes, the suction holes must be manually closed with a closing member. However, there is a problem that the working efficiency is reduced.

Further, since all of the above-mentioned conventional printed circuit board suction devices have a configuration using a substrate receiving table having a flat suction surface of the printed circuit board, a double-sided printed circuit board having components mounted on the back surface of the substrate is used. There is a problem that it cannot be absorbed and held.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and enables automatic selection of an appropriate suction portion of a printed circuit board and a double-sided mounting printed circuit board. It is another object of the present invention to provide a printed board suction device capable of effectively holding a double-sided mounted printed board.

[0011]

In order to achieve the above object, a printed circuit board suction device according to the present invention is a printed circuit board suction device for positioning a printed circuit board by vacuum suction using a plurality of suction portions. A pressure sensor that detects the pressure in each suction section and a valve that opens and closes the air suction path are connected to each of the air suction paths that connect the suction section and the vacuum pump .
Thus, by comparing each pressure and a set value in the plurality of suction units,
By outputting a close signal to a valve connected to the suction unit having a pressure higher than the set value in the suction unit, the valve is closed, and suction of air in the suction unit having a pressure higher than the set value is stopped. More specifically, the suction section is a suction hole formed in the thickness direction of the substrate receiving table, or a suction nozzle that can move up and down.

[0012]

According to the printed circuit board suction device of the present invention having the above structure, when the vacuum pump starts sucking air, the pressure in the suction portion (suction hole) closed by the back surface of the printed circuit board decreases, and In addition, the pressure in the suction portion that is not blocked by being overlapped with the dividing groove or the through hole on the back surface of the printed circuit board increases due to air leakage. Here, when the pressure in the suction section becomes higher than a predetermined set value, the pressure sensor detects this and the controller detects the pressure.
The set pressure is compared with the pressure detected by the
Close the valve connected to the suction unit where the force is higher than the set value . As a result, the suction of air from the suction unit where air is leaking is stopped, the suction force of the suction unit where air is not leaking increases, and the printed circuit board is effectively held. Also, when the plurality of suction portions are formed by suction nozzles that can move up and down, even in the case of a double-sided printed circuit board having components mounted on the back surface of the board, suction is performed according to the shape of the components mounted on the back surface of the board. The position of the nozzle in the height direction is automatically adjusted, and the double-sided printed circuit board is sucked and held without damaging the components.

[0013]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a printed circuit board suction apparatus according to an embodiment of the present invention. First, a printed board suction device according to a first embodiment of the present invention will be described. FIG. 1 is a perspective view illustrating a printed board suction device according to the present embodiment. FIG. 2 is a block diagram showing the printed board suction device. In the printed board suction device of the present embodiment, the suction portion of the printed board is constituted by a plurality of suction holes formed in the thickness direction of the board receiving table.

In these drawings, reference numeral 1 denotes a substrate support, on which a plurality of suction holes 1a are formed in the thickness direction. These suction holes 1 a are attached to the vacuum pump 2 via the air suction paths 3. Here, in this embodiment, a rubber hose is used for the air suction path 3. 4
Is a pressure sensor, which is connected to the suction hole 1a side of the air suction passage 3 connecting each suction hole 1a and the vacuum pump 2, detects a pressure in the air suction passage 3 connected to the suction hole 1a, and outputs a signal. . As the pressure sensor 4, for example,
A piezoelectric conversion element such as a pressure-sensitive diode or a pressure-sensitive transistor is used. Reference numeral 5 denotes a valve, which is connected to the vacuum pump 2 side of an air suction path 3 connecting each suction hole 1a and the vacuum pump 2. The valve 5 is connected to the air suction passage 3 based on a closing signal or an opening signal from the controller 6.
Open and close. The controller 6 is electrically connected to the vacuum pump 2, the pressure sensor 4, and the valve 5 (see FIG. 2). Set values for determining the presence or absence of air leakage are set in the controller 6 in advance, and the pressure in each air suction passage 3 is compared with the set values based on a signal from the pressure sensor 4. Then, a closing signal is output to the valve 5 connected to the air suction passage 3 in which the pressure in the air suction passage 3 is higher than the set value. Reference numeral 10 denotes a squeegee, which prints a cream solder 13 on a printed board 11 placed on the board receiving table 1 via a screen mask 12.

Next, the operation of the printed circuit board suction device of this embodiment will be described with reference to FIG. FIG. 3 is a flowchart showing the operation of the printed board suction device.
When the printed board 11 is placed on the board receiving table 1 and the vacuum pump 2 is operated, the controller 6 outputs an open signal to open all the valves 5. Thereby, all the suction holes 1a start sucking air (S1 to S3).

As a result, the pressure in the air suction passage 3 connected to the suction hole 1a closed by the back surface of the printed circuit board 11 is reduced, and overlaps with a dividing groove or a through hole formed on the back surface of the printed circuit board 11. The pressure in the air suction passage 3 connected to the suction hole 1a which is not blocked and becomes high due to air leakage. The controller 6 detects the pressure in each air suction passage 3 by the pressure sensor 4 and compares the pressure in each air suction passage 3 with a set value. Then, a close signal is output to the valve 5 connected to the air suction passage 3 having a pressure higher than the set value to close the valve 5 (S4, S4
5).

On the other hand, the valve 5 connected to the air suction passage 3 lower than the set value is kept open. As a result, suction of air from the suction hole 1a where air is leaking is stopped, and the printed circuit board 11 is effectively held and positioned. Thereafter, the squeegee 10 prints the cream solder 13 on the printed circuit board 11 (S6). When the printing of the cream solder 13 is completed and the operation of the vacuum pump 2 is stopped, the vacuum pump 2 outputs a close signal and closes all the valves 5 (S7, S8).

According to the printed circuit board suction apparatus of the present embodiment having the above-described configuration, an appropriate suction position of the printed circuit board can be automatically selected. 11 can be held effectively. Accordingly, it is not necessary to replace the board receiving table 1 due to the change in the shape of the printed board 11, and it is possible to reduce the cost of cream solder printing, and
Work efficiency is improved by reducing man-hours. Further, in the present printed board suction device, since air is not sucked from the suction hole 1a overlapping the through hole of the printed board 11, unnecessary cream solder is sucked into the vacuum pump 2 through the through hole. Can be prevented.

Next, a printed circuit board suction device according to a second embodiment of the present invention will be described with reference to FIG. FIG.
FIG. 2 is a partially enlarged cross-sectional view illustrating the printed board suction device according to the present embodiment. In the printed board suction device of the present embodiment,
The suction section of the printed circuit board is configured as a plurality of suction nozzles that can move up and down. In the figure, reference numeral 7 denotes a base which is moved in the vertical direction by a driving means (not shown), and has a plurality of guide holes 7a formed in the thickness direction.

Each of the guide holes 7a has a suction nozzle 8
Are attached elastically via a spring 9 and movably up and down. The upper end of each suction nozzle 8 protrudes from the base 7, and the lower end of each suction nozzle 8 is connected to the air suction path 3 below the base 7.

Further, the tips of the suction nozzles 8 are formed by suction cup-shaped elastic bodies 8a. This elastic body 8
“a” is for alleviating the impact at the time of contact with the mounted component of the double-sided printed circuit board 14 to protect the mounted component, and to enhance the adhesion after the contact.

According to the printed circuit board suction apparatus of this embodiment having the above-described structure, when the double-sided printed circuit board 14 having components mounted on the back surface of the substrate is placed on the suction nozzles 8, the double-sided printed circuit board 14 The position of the suction nozzle 8 in the height direction is automatically adjusted according to the shape of the component mounted on the back surface of the substrate, and the double-sided printed circuit board is suctioned and held without damaging the mounted component.

The printed circuit board suction device of the present invention comprises:
It is not limited to the above embodiment. For example, in the above-described embodiment, the case has been described in which the present printed board suction device is used for a cream solder printing machine. However, the present printed board suction device can also be used for positioning a printed board in an assembly line system of an electronic device or the like. . In the above embodiment, the controller 6 compares the pressure in each air suction path 3 with a set value and outputs a close signal to the valve 5. However, the present invention is not limited to this. Alternatively, a configuration may be used in which a signal that outputs a signal to the controller 6 only when a pressure equal to or higher than a predetermined value is detected is used, and a closing signal is output from the controller 6 based on a signal from the pressure sensor.

[0024]

As described above, according to the printed circuit board suction apparatus of the present invention, it is possible to automatically select the optimum suction position of the printed circuit board and the double-sided mounted printed circuit board. The printed board and the double-sided printed board can be effectively held.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a printed circuit board suction device according to a first embodiment of the present invention.

FIG. 2 is a block diagram illustrating the present printed board suction device.

FIG. 3 is a flowchart showing the operation of the printed board suction device.

FIG. 4 is a partially enlarged cross-sectional view illustrating a printed board suction device according to a second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate receiving stand 1a Suction hole 2 Vacuum pump 3 Air suction path 4 Pressure sensor 5 Valve 6 Controller 7 Base 7a Guide hole 8 Suction nozzle 8a Elastic body 9 Spring 10 Squeegee 11 Printed circuit board 12 Screen mask 13 Cream solder 14 Double-sided mounting print substrate

Claims (5)

(57) [Claims] 1. A printed circuit board suction device for positioning a printed circuit board by vacuum suction using a plurality of suction sections, wherein a pressure in each suction section is applied to each of air suction paths connecting the plurality of suction sections and a vacuum pump. The pressure sensor for detecting and the valve for opening and closing the air suction path are connected, and the controller compares each pressure in the plurality of suction units with a set value, and the suction unit in which the pressure in the suction unit is higher than the set value. A printed circuit board suction device, wherein a closed signal is output to a connected valve to close the valve and stop suction of air in a suction portion having a pressure higher than a set value. 2. The printed board suction device according to claim 1, wherein the suction portion is a suction hole formed in a thickness direction of the board receiving table. 3. The printed board suction device according to claim 1, wherein the suction portion is a suction nozzle that can move up and down. 4. The printed circuit board suction device according to claim 3, wherein the tip of the suction nozzle is formed of an elastic body. 5. The printed board suction device according to claim 3, wherein the suction nozzle is elastically attached to each guide hole of the base by a spring.