JP2689403B2 - Electronic component mounting method for picking up components - Google Patents

Description

Description: TECHNICAL FIELD [0001] The present invention relates to a method for determining a suction state of a component vacuum-sucked by a suction nozzle in an electronic component mounting machine.

[Prior art and its problems] Recently, when electronic components are automatically mounted on a printed circuit board, the electronic components in the component supply unit are vacuum-sucked by a suction nozzle, taken out, and transferred to a predetermined position on the printed circuit board. An electronic component mounting machine that is designed to be mounted is used. Also, while the electronic components of the component supply unit are vacuum-sucked by the suction nozzle and taken out, and transferred to the mounting position of the printed circuit board,
If a component is not sucked and held in a normal state, it cannot be mounted correctly when it is mounted on a printed circuit board.Therefore, it is necessary to judge whether the component is sucked in a normal state. There are various sizes, shapes, and the like, and it is necessary to accurately determine the suction state of these various different parts. For this reason, conventionally, there is a device that uses a camera or a photoelectric sensor to determine the suction state. However, if this is done, the device becomes large and the cost increases, so a simple digital output type vacuum sensor can be used. Although there were many, there were the following defects.

First, the schematic structure of a conventionally used electronic component mounting machine will be described with reference to FIG. 5. The electronic component mounting machine 1 is provided with a component supply unit 2 in which components are housed on the upper side thereof, and a print is performed on the upper center. A substrate transfer unit 3 for transferring and positioning a substrate is provided, and a suction nozzle is provided below a mounting head unit 4 provided above the substrate transfer unit 3.
Is moved by the XY robot 5 in the X and Y directions, and an operation panel 6 for inputting a device operation and a loading program on the side, and a control unit (not shown) for controlling the operation
And the like. To explain the operation with reference to FIG. 6, the component 2a at the tip of each component 2a of the component supply unit 2 is always located at the component suction position a, while the printed circuit board 7 transported by the substrate transport unit 3 is Stops in place. The suction nozzle 4a of the mounting head unit 4 is XY
The robot 5 moves to the component suction position a to suck the tip 2a by vacuum, and after suction, the XY robot 5 moves to a predetermined position on the printed circuit board 7 to mount the component 2a on the specified printed circuit board 7. The component 2a is mounted at a position and the above operation is sequentially repeated to mount the component 2a. The component supply unit 2
After the component 2a is picked up, the next component 2a is set by the part feeder or the like so that the next component 2a is located at the component pick-up position a.
The selection of the mounted component 2a, the mounting position on the printed circuit board 7, the procedure, etc. are all pre-programmed. Also,
When the suction posture of the component 2a is normal by the suction nozzle 4a as shown in FIG. 7, it is mounted on the normal position of the printed circuit board 7. However, when the suction posture is abnormal as shown in FIG. If it is not adsorbed, it will be mounted in an abnormal position or will not be mounted, the component mounting board will be defective, not only repair man-hours will be required, but also a defective board of a level that cannot be sorted by inspection. When mixed, the quality of the product using the substrate is greatly affected. In order to prevent such non-installation or improper installation, the suction posture is determined and it can be mounted only when suction is performed in the normal posture.
(OK) is instructed, and NG (unavailable) is instructed when an abnormal posture is sucked or not sucked, and control is performed such that the component suction operation is repeated after the component suction is released.

Here, an explanation will be given of a component suction determination method in a suction state using a conventional digital output type vacuum sensor. First, as shown in FIG. 9, the determination device is generally configured to generate a vacuum on the air circuit 8 of the suction nozzle 4a. There is a device 9, and a digital output type vacuum sensor 10 is provided in the middle of the air circuit 8. Then, a negative pressure is generated in the air circuit 8 by the vacuum generator 9, and the component 2a is vacuum-sucked by the suction nozzle 4a. When the suction state at this time is normal suction as shown in FIG. The amount of air leakage between the component and the component 2a is small, the air circuit 8 maintains a high degree of vacuum, and the vacuum degree at that time is detected by the digital output type vacuum sensor 10, and the judgment value set in advance in the sensor 10 (see FIG. 7). (Slightly lower than the vacuum level in the state), it is determined whether the actual vacuum level is higher or lower, and in the case of normal adsorption as shown in FIG. 7, a higher vacuum level than the determination value is shown. Therefore, the sensor 10 transmits the OK information to the CPU 11 of the control unit, and when the CPU 11 receives the OK information, the XY robot 5 moves the board 7 to the designated position and the parts
Instruct to install 2a. On the other hand, in the case of the abnormal adsorption as shown in FIG. 8, the air leak amount is large, the vacuum degree of the air circuit 8 becomes smaller than the judgment value, and the sensor 10 causes the CPU 11 to fail.
Information is transmitted to the XY robot 5, and then the XY robot 5 issues a component suction instruction again after releasing the suction component. The relationship between the degree of vacuum and the judgment value at this time is as shown in FIG. 10. In this FIG. 10, the horizontal axis shows the elapsed time with the component suction start time as 0, and the vertical axis shows the atmospheric pressure as 0. It represents the degree of vacuum, and in the case of normal suction in FIG. 7, the suction nozzle 4a starts from an unloaded state (vacuum degree H ₀ at that time), and after suction of parts, the degree of vacuum increases with the passage of time and eventually becomes steady. In this state, the degree of vacuum shows a substantially constant value, and the degree of vacuum H _{1 in the} steady state is higher than the judgment value H _J , but the curve at this time is 12. On the other hand, when the abnormal adsorption as shown in FIG. 8 starts at state H ₀ of no load, after the component suction, but reaches a steady state higher vacuum degree over time, the vacuum degree of H ₂ at that time Is lower than the judgment value H _J , the curve at this time is 13, and the degree of vacuum is measured and judged at time t ₁ after reaching the steady state from the component suction start time. The above operation is shown in the flowchart of FIG. However, the degree of vacuum in the air circuit 8 may vary even when the suction nozzle 4a is in an unloaded state.

In one case, a vacuum is usually used as the vacuum generator 9, and compressed air from an air compressor is used to generate a vacuum. In this case, the compressed air of the normal air compressor is also used for other devices, the compressed air pressure reaching the convum fluctuates, and the convum, that is, the degree of vacuum generated by the vacuum generator 9 fluctuates accordingly.

In other cases, as shown in FIG. 12, when the suction holes 4b of the suction nozzle 4a suck a small amount of cream solder or adhesive on the substrate 7 to cause clogging 4c, a cross-sectional area of the suction holes 4b is generated. Becomes substantially smaller, and the degree of vacuum of the air circuit 8 rises. The problem that occurs in this case will be described by way of example when the cylindrical component 2b is sucked.

FIG. 13 (a) shows a state where the cylindrical component 2b is normally sucked, FIG. 13 (b) shows an abnormal state where the flat end face of the cylindrical component 2b is sucked, and FIG. 13 (c) is It shows an abnormal state in which the corners of the cylindrical part 2b are adsorbed. At this time, the vacuum degree of the air circuit 8 is the highest in the case of FIG. 13 (b), the intermediate degree in the case of FIG. 13 (a), and the lowest in the case of FIG. 13 (c). The curve is shown in Fig. 14 and is shown in Fig. 13 (a).
In the case of, the curve 14 is formed, in the case of FIG. 13 (b), the curve 15 is formed, and in the case of FIG. 13 (c), the curve 16 is formed.

In addition, ΔH _J is the normal adsorption judgment area that is experimentally determined and set by two digital output type vacuum sensors.
And curve 16 are abnormally adsorbed, that is, NG is determined.

However, as described above, when the vacuum degree of the suction nozzle 4a in the unloaded state changes, the vacuum degree curve also changes accordingly. That is, as shown in FIG. 15, with respect to the degree of vacuum H ₀ immediately before the suction of the component, if the suction starts from a low level, the vacuum degree curve becomes low overall, and if the suction starts from a high level, the degree of vacuum curve Will be higher overall.

Therefore, as shown in FIG. 15, the curve corresponding to the curve 15 shown in FIG. 14 in which adsorption started from a low level H ₀ ′ is 15 ′.
The curve corresponding to the curve 16 shown in FIG. 14 in which the adsorption started from the high level H ₀ ″ is 16 ′, and both the curves 15 ′ and 16 ′ are OK for the normal adsorption determination area ΔH _J described above. That is, the abnormal suction as shown in FIGS. 13 (b) and 13 (c) is erroneously determined to be OK, and the mounting operation on the substrate 7 is performed. The component suction state determination device used cannot cope with the pressure fluctuation of the air circuit 8, and thus has a problem that a wrong determination is made and a defective substrate is generated.

[Object of the Invention] The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to easily respond to pressure fluctuations in the suction nozzle air circuit system to enable accurate determination. Another object of the present invention is to provide a component suction determination method for an electronic component mounting machine.

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the present invention vacuum-adsorbs a component by a suction nozzle of a mounting head in an electronic component mounting machine, and detects vacuum degree information of the vacuum suction by an analog output type vacuum sensor. In the method for determining the component suction state of the suction nozzle, the difference between the no-load vacuum degree and the reference no-load vacuum degree in various states of the suction nozzle, and the vacuum degree determination level at the time of component vacuum suction corresponding to the difference The range is stored in advance for each of the various states, and the difference between the no-load vacuum degree before component suction detected by the vacuum degree sensor and the reference no-load vacuum degree is calculated, and the difference is calculated from the stored values. Set the vacuum degree judgment level range corresponding to the difference, and collate the set vacuum degree judgment level range with the vacuum degree information at the time of component vacuum suction detected by the vacuum sensor. The main point is to determine the component suction state.

[Embodiment] One embodiment of the present invention will be described below with reference to FIGS. The vacuum generator 9 is attached to the air circuit 8 of the suction nozzle 4a, and the analog output type vacuum sensor 17 is attached to the air circuit 8 between the suction nozzle 4a and the vacuum generator 9. The degree of vacuum immediately before adsorption is detected, and the information on the degree of vacuum is transmitted to the CPU 11, but various states of the adsorption nozzle 4a, that is, the adsorption nozzle.
The suction hole 4b of 4a sucks a small amount of cream solder or adhesive etc. to cause clogging, etc., and the no-load vacuum degree or the suction nozzle 4a depending on the size of the cross-sectional area of the suction hole 4b. The CPU 11 stores a no-load vacuum degree in various states such as a change in air pressure, a change in atmospheric pressure, different nozzles having different inner diameters, and a vacuum degree determination level range corresponding to the no-load vacuum degree in vacuum suction of components. The CPU 11 compares this degree of vacuum with the reference degree of vacuum H ₀ and corrects the OK determination area as much as the difference. This correction value is obtained experimentally, and the CPU1
Fill in 1. Further, the CPU 11 instructs the suction nozzle 4a via the XY robot 5.

 In addition, 2a is a component to be sucked.

Incidentally, when describing the details corrected by FIGS. 2 and 3 diagram, commensurate with FIG. 2 'shows a state in which suction is started from the differential pressure △ H _0' low degree of vacuum H ₀ than H ₀ Only
The reference OK judgment area ΔH _J has been corrected to ΔH _J ′. Thus, curve 15 described above in the section of the prior art problems by Figure 15 'is corrected OK determination area △ H _J' is determined as NG off the.

Further, FIG. 3 shows the state when adsorption starts from a vacuum degree H ₀ ″ which is higher than H ₀ , and the reference OK judgment area ΔH _J becomes ΔH _J ″ as much as the differential pressure ΔH ₀ ″. Therefore, the curve 16 'described in the section of the problem of the prior art according to Fig. 15 is judged to be NG out of the corrected OK judgment area ΔH _J ″.

As described above, with the constant OK determination area ΔH _J , as shown in FIG.
What is judged to be OK even in the case of abnormal suction as shown in FIGS. (B) and (c) is the actual degree of vacuum and the reference vacuum of the air circuit 8 of the suction nozzle 4a immediately before the start of suction of parts as in this embodiment. CP that received the information detected by the sensor 17
U11 corrects and sets the OK judgment area to ΔH _J ′ or ΔH _J ″ so that it will be judged as NG, and the component suction judgment method of this embodiment can make an accurate judgment. To

 Next, the steps of the suction operation will be described with reference to FIG.

I OK determination area (ΔH _J ′ or ΔH _J ″) to correct the difference between the actual vacuum degree (H ₀ ′ or H ₀ ″) of the air circuit 8 system of the suction nozzle 4a and the reference vacuum degree (H ₀ ). ) Experimentally, and input to CPU11.

The II CPU 11 stores the information I, and the III CPU 11 instructs the suction operation of the component 2a.

The sensor 17 detects the vacuum degree (H ₀ ′ or H ₀ ″) of the air circuit 8 immediately before the IV suction nozzle 4a sucks the component 2a, and the CP
The vacuum information is transmitted to U11.

The V CPU 11 determines the difference (△) between the information and the reference vacuum degree (H ₀ ).
Calculate H ₀ ′ or ΔH ₀ ″).

The OK determination area (ΔH _J ′ or ΔH _J ″) corrected by the CPU 11 is set based on the information of VI II and the difference in vacuum degree (ΔH ₀ ′ or ΔH ₀ ″) immediately before adsorption of V.

VII The suction nozzle 4a sucks the component 2a.

The sensor 17 detects the degree of vacuum of the air circuit 8 when t ₁ hour has passed after the VIII component 2a is sucked (a steady suction state is reached).

The CPU 11 judges the degree of vacuum detected by IX VII by the OK judgment area (ΔH _J ′ or ΔH _J ″) set by VI.

When the judgment in X IX becomes NG, the suction of the component 2a is released, then the process returns to III and the suction operation start of the same type component is started again.
PU11 gives instructions.

When the determination in XI IX becomes OK, the CPU 11 instructs the component mounting.

The XII component 2a is mounted on the board 7.

[Effects of the Invention] As described in detail above, a suction nozzle of a mounting head in an electronic component mounting machine vacuum-sucks a component, and vacuum degree information of the vacuum suction is detected by an analog output type vacuum sensor. The difference between the no-load vacuum degree in various states and the reference no-load vacuum degree, and the vacuum degree determination level range at the time of component vacuum suction corresponding to the difference are stored in advance for each of the various states. By calculating the difference between the no-load vacuum degree before component suction detected by the above and the reference no-load vacuum degree, a vacuum degree determination level range corresponding to the calculated difference is set from the stored values, and the set vacuum is set. Level determination level range and the vacuum degree information at the time of component vacuum suction detected by the vacuum sensor are collated to determine the component suction state, so that the suction nozzle air circuit system has no load. Even if the degree of vacuum changes, the accurate determination can be easily made by the range of the degree-of-vacuum determination level at the time of normal suction of the component set corresponding to the change. Also, since only one analog output type vacuum sensor needs to be used for the determination,
The entire device can be downsized and the manufacturing cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a diagram showing a vacuum degree judgment level range at the time of normal suction when the no-load vacuum degree immediately before suction of components is lower than a reference value. Three
Figure is a diagram showing the vacuum level judgment level range during normal suction when the no-load vacuum level immediately before component pick-up is higher than the reference value. Fig. 4 is the flow chart of Fig. 1. Fig. 5 is an electronic component mounting machine. FIG. 6 is an explanatory view showing a component mounting head portion and its periphery, FIG. 7 is an explanatory diagram showing a state where components are normally adsorbed, and FIG. 8 is an explanation showing a state where components are abnormally adsorbed. Fig. 9 is a block diagram showing a conventional component suction determination method, Fig. 10 is a vacuum degree vs. time diagram of a suction nozzle in the case of normal suction and abnormal suction, and Fig. 11 is a conventional component suction determination method. Flow chart, FIG. 12 is a vertical cross-sectional view showing a state where the suction holes are clogged, FIG. 13 shows three types of suction states of a cylindrical part, FIG. 13 (a) is normal, and FIG. 13 (b). , (C)
Indicates an abnormal state. FIG. 14 is a diagram showing the degree of vacuum versus time for each of the cases shown in FIGS. 13 (a), (b), and (c) according to the conventional method for determining the component suction when the suction vacuum degree with no load is a reference value. FIG. 15 is a vacuum versus time diagram for FIGS. 13 (b) and 13 (c) according to the conventional component suction determination method when the suction vacuum degree when no load is applied is increased or decreased. 1 ... Electronic component mounting machine, 2a ... Component, 4 ... Mounting head part (mounting head), 4a ... Suction nozzle, 11 ... CPU, 17
...... Analog output type vacuum sensor.

Front page continuation (72) Inventor Makoto Kumagai 1 5400 Higashioneko, Higashine, Yamagata Prefecture Yamagata Casio Co., Ltd. (56) Reference JP-A 1-228735 (JP, A) , U) Actual development Sho 63-197026 (JP, U)

Claims (1)

(57) [Claims] 1. A method of vacuum suctioning a component by a suction nozzle of a mounting head of an electronic component mounting machine, detecting vacuum degree information of the vacuum suction by a vacuum sensor, and determining a component suction state of the suction nozzle. The difference between the no-load vacuum degree in each state of the suction nozzle and the reference no-load vacuum degree, and the vacuum degree determination level range at the time of component vacuum suction corresponding to the difference are stored in advance for each of the various states. The difference between the no-load vacuum degree before component suction detected by the degree sensor and the reference no-load vacuum degree is calculated, and the vacuum degree judgment level range corresponding to the calculated difference is set from the stored values. Electronic component mounting characterized in that the component suction state is determined by collating the vacuum degree determination level range with the vacuum degree information at the time of component vacuum suction detected by the vacuum sensor. Method for component suction on machine.