JP2009194078A - Electronic component mounting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily acquire back pressure characteristics even when an ejector is still fitted to an electronic component mounting device, and to easily decide whether negative pressure generating capability is good. <P>SOLUTION: The electronic component mounting device includes a suction nozzle 20 mounted on a mounting head and sucking an electronic component with negative pressure, the ejector 24 applying the negative pressure through connected piping 22, to the suction nozzle, a valve 26 controlling the flow rate of gas flowing in the piping, a flowmeter 28 detecting the flow rate of the gas controlled by the valve, and a pressure manometer 30 measuring negative pressure-side pressure by the ejector, wherein the mounting device has a decision means of: measuring back pressure characteristics of the ejector during the operation of the ejector from the relation between the flow rate detected by the flow meter and the pressure detected by the pressure manometer; and comparing the measured back pressure characteristics with a previously generated propriety criterion to decide the negative pressure generating capability of the ejector. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an electronic component mounting apparatus, and more particularly to an electronic component mounting apparatus including a negative pressure adsorption device that adsorbs an electronic component by negative pressure.

  Compared to the method of holding and transporting electronic components by suction at the tip of the suction nozzle with a negative pressure, the method is simpler, space-saving, and faster than the method of holding and transporting by electronic chuck. For this reason, it is widely used in electronic component mounting apparatuses.

  There are several types of devices that generate negative pressure for this purpose, such as vacuum pumps. Among them, the ejector, which is a type of vacuum generator that generates negative pressure from the pressure difference in the piping path when pressurized air is supplied, is space-saving. In addition, since switching between negative pressure and positive pressure is also good, it is widely used in electronic component mounting apparatuses (see, for example, Patent Document 1).

  However, the ejector's ability to generate negative pressure decreases depending on the environment and frequency of use, and causes defective suction of components. Ejectors with reduced capacity can be dealt with by replacing them with new ones. However, in electronic component mounting devices that are operating on a daily production schedule that is closely assembled, The time loss due to the replacement of parts in this case directly affects the profit and cannot be easily replaced.

  Therefore, it is an effective means for avoiding loss to predict the occurrence of a problem from a decrease in the negative pressure generation capability of the ejector and to replace the ejector systematically.

  In general, the negative pressure generation capability of an ejector incorporated in an electronic component mounting apparatus is determined by a vacuum ultimate pressure. However, there is a problem when trying to determine the negative pressure generation capability of the ejector only by the vacuum ultimate pressure.

  For example, if the part to be adsorbed and the nozzle are in close contact with each other with no gap, the air flow rate is 0. Therefore, the negative pressure generation capability of the ejector can be reduced by looking at the pressure when the suction flow rate becomes 0. The ultimate pressure can be easily determined.

  However, in the situation where the occurrence of a gap in the contact portion between the nozzle and the component is unavoidable, for example, when there are many irregularities in the surface shape like an electronic component such as a connector, etc. Since air is always sucked from the gap, the negative pressure generation capability of the ejector cannot be determined based on the ultimate pressure detected at a flow rate of zero.

  When determining the negative pressure generation capability of the ejector other than the vacuum ultimate pressure at a flow rate of 0, it is necessary to obtain a back pressure characteristic that represents the relationship between the flow rate of air sucked by the ejector and the pressure value.

Japanese Patent No. 3905793

  However, since the conventional electronic component mounting apparatus did not have a function for acquiring the back pressure characteristics, in order to acquire the back pressure characteristics, the ejector was temporarily removed from the apparatus and a dedicated measuring instrument provided separately. It has to be attached and measured, and the loss increases in terms of time and work. Therefore, the ejector once assembled in the apparatus has not been performed because it is difficult to obtain the back pressure characteristics.

  The present invention has been made to solve the above-described conventional problems, and can easily obtain the back pressure characteristics even when the ejector is attached to the apparatus. It is an object of the present invention to provide an electronic component mounting apparatus that can be carried out without any loss.

  The present invention provides an electronic component mounting apparatus that includes a mounting head that holds electronic components by suction from a component supply unit and is mounted on a substrate, and a suction nozzle that is mounted on the mounting head and sucks the electronic components by negative pressure; An ejector for supplying a negative pressure to the suction nozzle through a pipe connected to the suction nozzle; a valve for adjusting a flow rate of the gas flowing through the pipe; a flow meter for detecting a flow rate of the gas adjusted by the valve; and the ejector A pressure gauge for measuring the pressure on the negative pressure side of the ejector, and from the relationship between the flow rate detected by the flow meter and the pressure detected by the pressure gauge during operation of the ejector, A determination means for measuring the pressure characteristic, comparing the measured back pressure characteristic with a quality criterion prepared in advance, and determining the negative pressure generation capability of the ejector; It is obtained by solving the above problems.

  According to the present invention, the ejector for supplying the negative pressure to the suction nozzle mounted on the mounting head can acquire the back pressure characteristic by appropriately measuring the flow rate and the pressure when the negative pressure is generated. By comparing with the created pass / fail judgment criteria, it is possible to easily judge pass / fail of the negative pressure generating ability of the ejector even when the ejector is attached to the apparatus.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a perspective view showing an outline of an electronic component mounting apparatus according to an embodiment of the present invention.

  The electronic component mounting apparatus 10 includes a mounting head 11. The mounting head 11 is moved in the X direction by an X-axis guide 12 and moved in the Y direction by a Y-axis guide 13 integrally with the X guide 12. As a result, an electronic component (not shown) is sucked and held from a tape feeder (component supply unit) 14 by a suction nozzle, which will be described later, and after being recognized by the component recognition camera 15, it is mounted on the positioned substrate S. It is possible.

  As schematically shown in FIG. 2, the mounting apparatus 10 of the present embodiment is attached to the mounting head 11 and connected to the suction nozzle 20 that sucks an electronic component (not shown) by negative pressure, and the suction nozzle 20. And an ejector 24 attached to the mounting head 11 for supplying a negative pressure through the pipe 22. Further, a valve 26 for adjusting the flow rate of the gas passing through the pipe 22, a flow meter 28 for detecting the flow rate of the gas adjusted by the valve 26, and a pressure gauge 30 for measuring the pressure on the negative pressure side by the ejector 24 It has. Here, the valve 26, the flow meter 28, and the pressure gauge 30 may be disposed anywhere as long as they are on the suction side (negative pressure side) of the ejector 24.

  In the present embodiment, as shown in FIG. 3, the gas control circuit corresponding to FIG. 2 is used to control the opening degree of the valve 26 by the control unit 32 included in a control device (not shown) that controls the entire mounting device 10. It can be adjusted.

  In addition, detection values are input to the control unit 32 as sensor outputs from the flow meter 28 and the pressure gauge 30, respectively, corresponding to an arbitrary opening adjustment position of the valve 26.

  On the other hand, the controller 32 determines whether the negative pressure generation capability is good or not with respect to the back pressure characteristic of the ejector 24 measured from the relationship between the flow rate detected by the flow meter 28 and the pressure detected by the pressure gauge 30. A reference line representing a pass / fail criterion for determination is experimentally created and stored in advance. FIG. 4 shows an example of this pass / fail judgment reference line.

  In the present embodiment, the control unit (determination means) 32 compares the relationship between the flow rate and pressure (back pressure characteristics) appropriately detected during operation of the ejector 24 with the pass / fail judgment reference line, thereby providing the ejector. The negative pressure generation capability of 24 is determined.

  That is, as shown in the flow chart of FIG. 5, the ejector 24 is operated to turn on the vacuum to suck the electronic component (step 1), detect the pressure when the component is sucked (step 2), and detect the flow rate. (Step 3).

  Next, the relationship between the detected pressure and flow rate is compared with the pass / fail judgment reference line in FIG. 4 (step 4), and if it is below the pass / fail judgment reference line, a warning is issued.

  Further, even when parts are not picked up, the flow rate is adjusted by the valve 26 as necessary so that the relation between the flow rate and the pressure can be detected.

  According to the embodiment described in detail above, since the mounting head 11 has the pressure detection function and the flow rate detection function during the operation of the ejector 24, the pressure and the flow rate are detected when the electronic component is attracted or at any time. By comparing the relationship between the detected pressure and flow rate with a predetermined pass / fail judgment reference line, it is possible to provide a function for judging pass / fail.

  As a result, the following effects were obtained.

  (1) Since it is possible to determine the quality of the ejector without removing the ejector from the electronic component mounting apparatus, it is possible to reduce time and work loss.

  (2) Since it is possible to easily judge whether the ejector is good or bad, it is possible to quickly know the decline in the ejector's capacity and to perform planned production.

The perspective view which shows the outline | summary of the electronic component mounting apparatus of one Embodiment which concerns on this invention The schematic diagram which shows the relationship between the suction nozzle and ejector which are contained in the negative pressure generation part of the mounting head with which the electronic component mounting apparatus of this embodiment is equipped. Gas control circuit diagram showing an outline of the determination control unit of the negative pressure generation unit Diagram showing the relationship between ejector back pressure characteristics and pass / fail criteria Flow chart showing the operation of this embodiment

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Electronic component mounting apparatus 11 ... Mounting head 12 ... X-axis guide 13 ... Y-axis guide 14 ... Tape feeder 15 ... Component recognition camera 20 ... Adsorption nozzle 22 ... Piping 24 ... Ejector 26 ... Valve 28 ... Flow meter 30 ... Pressure gauge S ... Board

Claims (1)

In an electronic component mounting apparatus equipped with a mounting head that sucks and holds electronic components from a component supply unit and mounts them on a substrate.
A suction nozzle that is mounted on the mounting head and sucks electronic components by negative pressure;
An ejector for supplying a negative pressure to the suction nozzle through a connected pipe;
A valve for adjusting the flow rate of the gas flowing in the pipe;
A flow meter for detecting a flow rate of gas adjusted by the valve;
A pressure gauge for measuring the pressure on the negative pressure side by the ejector, and
During the operation of the ejector, the back pressure characteristic of the ejector is measured from the relationship between the flow rate detected by the flow meter and the pressure detected by the pressure gauge, and the measured back pressure characteristic is created in advance. An electronic component mounting apparatus comprising: a determination unit that determines a negative pressure generation capability of the ejector in comparison with a pass / fail determination criterion.