JP2007048921A - Electronic component image acquiring method and apparatus thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image acquiring method and an apparatus for acquiring sharp and adequate images by always imaging components in the focusing state, even if the components are actually fluctuated in the thickness. <P>SOLUTION: An attracting nozzle 13a is moved downward to obtain quantity of downward movement Z1 and Z2 of the attracting nozzle when the front end of nozzle and the imaging surface of component 11 are crossing the laser beam 14c projected from a laser beam emitter 14a. Since such Z1-Z2 correspond to thickness of the components, the attracting nozzle 13a is moved downward in accordance with the detected component thickness until the imaging surface (lower surface) of component is matched with the focusing surface of the imaging apparatus 16. Under this condition, a component 11 is imaged with the imaging apparatus 16 so that the component 11 is always imaged in the focusing state to obtain sharp and adequate image even if thickness of component 11 is actually fluctuated. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electronic component image acquisition method and apparatus for acquiring an image of an electronic component by imaging the electronic component sucked by a suction head with an imaging device in an electronic component mounting apparatus, for example.

  In the electronic component mounting apparatus, before mounting the component (electronic component) sucked by the suction head on the substrate, the suction component is imaged by the imaging device, and the center position and inclination of the suction component are recognized from the captured image. A so-called component recognition is performed, and the suction displacement is corrected based on the recognition result, and the component is mounted at a predetermined position on the board in a correct posture.

With such a configuration, if the captured image of the component is out of focus, the component recognition cannot be performed with high accuracy, and the component mounting accuracy is deteriorated. On the other hand, as described in Patent Document 1 below, when imaging a component sucked by the suction head, the surface to be imaged (lower surface) of the component based on the thickness data of the component registered in advance. A technique has been proposed in which the suction head is positioned so that the position of the suction head coincides with the in-focus plane of the imaging apparatus. According to this technique, if the actual thickness of the component matches the pre-registered thickness at the time of imaging, the imaged surface of the component matches the in-focus surface, so the captured image of the component is out of focus. Never become.
Japanese Patent No. 2801331

  However, in the technique such as Patent Document 1, when the tolerance of parts to be imaged is large and the variation in the actual thickness of the parts is large, the position of the surface to be imaged varies depending on the parts during imaging, and the focusing surface of the imaging apparatus Therefore, there is a problem that defocusing occurs and the accuracy of component recognition deteriorates.

  In addition, if an incorrect value is registered when the thickness of the component is registered in advance and the system of the electronic component mounting apparatus is operated without causing an error in that state, it will remain in a state where defocusing occurs when imaging the component. In this case, there is a problem that component recognition is performed, component recognition accuracy deteriorates, and component mounting accuracy deteriorates.

  Therefore, an object of the present invention is to obtain a sharp and appropriate image by always imaging a component in an in-focus state regardless of variations in the actual thickness of the electronic component or a difference between the thickness registered in advance and the actual thickness. An object of the present invention is to provide an image acquisition method and apparatus for electronic components that can be acquired.

In order to solve the above problems, the present invention (Claim 1)
An image acquisition method for acquiring an image of an electronic component by imaging an electronic component sucked by a suction head with an imaging device,
Measure the thickness of the electronic component sucked by the suction head,
In accordance with the actually measured thickness of the electronic component, the position of the suction head or the position of the imaging device is controlled so that the imaging surface of the electronic component comes to the in-focus surface of the imaging device.

The present invention also provides:
An image acquisition device for acquiring an image of an electronic component by imaging an electronic component sucked by a suction head with an imaging device,
Actual measurement means for actually measuring the thickness of the electronic component sucked by the suction head;
Control means for controlling the position of the suction head or the position of the imaging device so that the surface to be imaged of the electronic component comes to the in-focus surface of the imaging device according to the measured thickness of the electronic component;
It is characterized by having.

  According to the present invention, the positions of the imaging surface of the electronic component and the focusing surface of the imaging device are matched on the basis of the actually measured thickness of the electronic component attracted by the suction head. Regardless of the actual thickness variation or the difference between the pre-registered thickness and the actual thickness, it is possible to capture a part in the focused state and acquire a sharp and appropriate image. Therefore, the accuracy of component recognition at the time of component mounting is improved, and the mounting accuracy of components on the board is improved. Further, it is not necessary to strictly manage the thickness data of the electronic component, and an excellent effect that the management burden can be reduced is obtained.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Here, an embodiment of an electronic component mounting apparatus including an image acquisition device that acquires an image of an electronic component sucked by the suction head will be described.

  FIG. 1 schematically shows a mechanical configuration of a component mounting apparatus. As shown in the figure, the component mounting apparatus 1 includes a component supply unit 12 that supplies electronic components mounted on the circuit board 10, a circuit board conveyance path 15 that extends in the left-right direction slightly behind the center, An X-axis moving mechanism 2 and a Y-axis moving mechanism 3 disposed above these are provided.

  The X-axis moving mechanism 2 is equipped with a suction head 13 having a suction nozzle 13a for sucking parts, and the X-axis moving mechanism 2 moves the suction head 13 in the X-axis direction. Further, the suction head 13 is moved in the Y axis direction together with the X axis moving mechanism 2 by the Y axis moving mechanism 3. Although not shown in detail in FIG. 1, the suction head 13 rotates around the θ axis (nozzle axis) and a Z axis moving mechanism that moves the suction nozzle 13a in the Z axis direction (up and down direction). A θ-axis rotating mechanism is provided.

  In addition, the suction head 13 is equipped with an image pickup device (CCD camera or the like) 17 that picks up a substrate mark on the substrate 10 and can recognize the substrate mark and correct the positional deviation of the substrate. Further, a laser unit 14 is provided below the suction head 13 (nozzle 13a side). As shown in FIGS. 2 to 4, the laser unit 14 includes a laser light emitting unit 14 a and a laser light receiving unit 14 b that are arranged to face each other with the suction nozzle 13 a interposed therebetween.

  In addition, a component imaging device (CCD camera or the like) 16 is disposed on the side of the component supply unit 12, and the suction head 13 comes to the upper side of the imaging device 16 after suctioning the components and is sucked by the suction nozzle 13a. The imaged part is imaged by the imaging device 16. In addition, an operation monitor 18 is provided on the upper front surface of the mounting apparatus 1, thereby operating the mounting apparatus 1 and displaying a device status related to the operation.

  Further, a control unit 19 is provided in the lower main body of the mounting apparatus 1. The control unit 19 includes a main control device 22 and an image processing device 21 in the control system of the mounting apparatus shown in FIG.

  The CPU 221 of the main control device 22 controls the entire mounting device. The X-axis motor 23, the Y-axis motor 24, and the Z-axis motor 25 move the suction head 13 in the X-axis, Y-axis, and Z-axis directions. And the driving of the θ-axis motor 26 that rotates the suction nozzle 13a around the θ-axis is controlled. The main control device 22 also controls the light emission control 222 for controlling on / off of the light emission of the laser light emitting unit 14a of the laser unit 14 and the laser light emitting unit 14a of the laser unit 14 when the component is imaged. And a memory 224 for storing various data.

  On the other hand, in the image processing device 21, an image signal (analog signal) of the component 11 output from the imaging device 16 is input to the image processing device 21 and A / D converted into digital component image data by the A / D converter 211. And stored in the image memory 212. The image processing apparatus 21 stores component data such as the shape of the component 11, component dimensions, lead width, lead pitch, and lead length, and data such as suction position and mounting position for each component. A portion 215 is provided. The CPU 216 of the image processing device 21 reads and executes the component recognition program 214 stored in the memory, processes the component image data stored in the image memory 212 using the component data in the component data storage unit 215, and Calculate center and component tilt. The work memory 213 is used as a work memory at the time of image processing.

  A component adsorption deviation is calculated from the component center position and the component inclination calculated by the image processing described above, and this deviation amount is transmitted to the main control device 22 via the interface 217. The main control device 22 reflects the deviation amount when driving the X-axis motor 23, the Y-axis motor 24, and the θ-axis motor 26, corrects the adsorption deviation, and mounts the component 11 on the substrate 10.

  In the present invention, in order to perform focusing control according to the thickness of the component, the thickness of the component is measured by the laser unit 14 attached to the suction head 13.

  As shown in FIG. 3, the laser light emitting unit 14a irradiates the laser light 14c horizontally toward the laser light receiving unit 14b at a predetermined height below the bottom of the suction head 13 and H1. The laser beam 14c may be a strip-shaped laser beam that is thin in the Z direction (linear) and spreads two-dimensionally in the XY plane, or one or a plurality of laser beams. The laser light receiving unit 14 b receives the laser light 14 c and outputs an output signal corresponding to the amount of received light to the main control device 22. The CPU 221 of the main control device 22 receives an output signal from the laser light receiving unit 14b and detects a change in the signal, and the CPU 221 determines the drive amount (rotation amount) of the Z-axis motor 25 by a rotary encoder (not shown). Detecting and detecting the descending amount of the suction nozzle 13a.

  With such a configuration, the actual measurement of the thickness of the component 11 is performed as follows. First, as shown in FIG. 3, the Z-axis motor 25 is driven and the suction nozzle 13a is sequentially lowered from the initial position H2 in a state where the suction nozzle 13a is not picking up components. Then, the suction nozzle 13a when the position of the tip (lower end) of the nozzle 13a in the Z-axis direction coincides with the laser beam 14c, the laser beam 14c is shielded by the tip, and the voltage of the output signal of the laser receiving unit 14b changes. Is detected from the initial position H2 (rotation amount of the Z-axis motor 25) Z1 and stored in the memory 224.

  Next, the suction nozzle 13a is sequentially lowered from the initial position H2 with the component 11 being sucked by the suction nozzle 13a as shown in FIG. Then, from the initial position H2 of the suction nozzle 13a when the position of the imaging surface (lower surface) of the component 11 coincides with the laser beam 14c and the laser beam 14c is shielded by the lower surface of the component and the output of the laser receiving unit 14b changes. Is detected (the amount of rotation of the Z-axis motor 25) Z2, and the value is stored in the memory 224. Then, Z1-Z2 is calculated as an actual measurement value of the thickness of the component 11.

  Next, a series of operations from component suction to mounting will be described along the flow shown in FIG.

  The X-axis motor 23 and the Y-axis motor 24 are driven to move the suction head 13 onto the component supply unit 12, and the Z-axis motor 25 is further driven to lower the suction nozzle 13 a from the initial position H <b> 2 for the component suction operation. Enter (step S1).

  The lowering amount Z1 (FIG. 3) of the suction nozzle 13a when the suction nozzle 13a is lowered and the laser beam 14c is shielded by the nozzle tip is detected (step S2) and stored in the memory 224.

  When the component 11 is sucked by the suction nozzle 13a, the suction nozzle 13a returns to the initial position H2, the suction head 13 is moved above the imaging device 16, and the imaging axis of the imaging device 16 is moved as shown in FIG. It stops at a position that coincides with the axis of the suction nozzle 13a. At this time, it is assumed that the surface (focusing surface) on which the subject photographed by the imaging device 16 is in focus is further below the initial position H2 by H3.

  Subsequently, the suction nozzle 13a is lowered from the initial position H2, and the lowering amount Z2 of the suction nozzle 13a when the laser beam 14c is shielded by the imaging surface (lower surface) of the component 17 is detected (step S4). Is stored in the memory 224. Then, Z3 = H3− (Z1−Z2) is calculated, and when the suction nozzle 13a is lowered by Z3 from the initial position H2, the lowering of the suction nozzle 13a is stopped. In this process, the lowering amount of the suction nozzle 13a is controlled according to the thickness (Z1-Z2) of the component, and when the suction nozzle 13a is stopped, the imaging surface of the component 11 is focused on the imaging device 16. (Step S5).

  Next, the illumination device 20 is turned on to illuminate the sucked component 11, and the imaging device 16 images the component 11 (step S6).

  The captured image of the component 11 is input to the image processing device 21, and the image processing device 21 performs image processing by a known method to calculate the center position and inclination of the component 11 (step S7).

  The main controller 22 controls the driving of the X-axis motor 23, the Y-axis motor 24, and the θ-axis motor 26 based on this calculation result, corrects the amount of adsorption deviation, and mounts the component 11 on the circuit board 10. (Step S8).

  As described above, according to the present embodiment, the part 11 is always imaged in the focused state regardless of the variation in the actual thickness of the part 11 or the difference between the thickness registered in advance and the actual thickness. A sharp and appropriate image can be acquired, and the accuracy of component recognition can be improved.

  In the above embodiment, the lowering amount Z1 of the suction nozzle when the laser beam is shielded by the tip of the nozzle is measured by the first lowering operation of the suction nozzle at the time of component suction. At this time, the descending amount Z1 may be measured in advance. Further, if the once-falling amount Z1 is measured, the value is stored in the memory, so it is not necessary to measure the descending amount Z1 for each adsorption operation.

  In the above-described embodiment, the component thickness is measured based on the lowering operation of the suction nozzle 13a, but the suction nozzle 13a is temporarily moved to a position below the light projection surface of the laser light 14c, The suction nozzle 13a may be moved upward from the position, and the thickness of the part may be measured by detecting the amount of rise of the suction nozzle 13a when the tip of the suction nozzle and the lower surface of the part cross the laser beam 14.

  In addition, the suction nozzle is lowered or raised while the component is sucked to the suction nozzle 13a, and the time when the lower surface of the component and the upper surface of the component (corresponding to the tip of the suction nozzle) cross the laser beam 14 is measured. The thickness of the component can also be measured by multiplying the suction nozzle raising / lowering speed (constant).

  Further, by imaging a range in the Z-axis direction larger than the thickness of the component 11 sucked by the suction nozzle 13 by a two-dimensional imaging device, the component thickness may be directly measured from the image.

  For chip parts that do not require relatively high accuracy, a laser beam is generated by a laser unit attached to the suction head, and the part sucked by the suction nozzle is rotated within the belt-shaped laser light. Component recognition is performed by looking at the change in the shadow of the component. Accordingly, when the above-described component thickness is detected using this laser unit, the thickness of the component can be measured without adding a new component.

  Further, means for moving the imaging device 16 in the Z-axis direction is provided, and in step S5 in FIG. 6, instead of moving the sucked component 11 in the Z-axis direction, the imaging device 16 is moved in the Z-axis direction according to the component thickness. The in-focus surface and the imaged surface of the component 11 can be made to coincide with each other.

It is the perspective view which showed roughly the mechanical structure of the electronic component mounting apparatus by which this invention is used. It is a block diagram which shows the structure of the control system of the apparatus. It is explanatory drawing of operation | movement which measures the thickness of the electronic component adsorbed | sucked by the suction nozzle with the same apparatus. It is explanatory drawing of the operation | movement which measures the thickness of an electronic component. It is explanatory drawing of the operation | movement which makes the to-be-imaged surface of an electronic component correspond with the focusing surface of an imaging device. It is a flowchart figure which shows the control procedure of operation | movement from adsorption | suction of components to mounting.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electronic component mounting apparatus 2 X-axis moving mechanism 3 Y-axis moving mechanism 10 Circuit board 11 Electronic component 12 Component supply part 13 Suction head 13a Suction nozzle 14 Laser unit 16 Component imaging device 20 Illumination device 21 Image processing device 22 Main control device 221 CPU
23 X-axis motor 24 Y-axis motor 25 Z-axis motor 26 θ-axis motor

Claims (2)

An image acquisition method for acquiring an image of an electronic component by imaging an electronic component sucked by a suction head with an imaging device,
Measure the thickness of the electronic component sucked by the suction head,
In accordance with the actually measured thickness of the electronic component, the position of the suction head or the position of the imaging device is controlled so that the surface to be imaged of the electronic component comes to the focusing surface of the imaging device. Image acquisition method. An image acquisition device for acquiring an image of an electronic component by imaging an electronic component sucked by a suction head with an imaging device,
Actual measurement means for actually measuring the thickness of the electronic component sucked by the suction head;
Control means for controlling the position of the suction head or the position of the imaging device so that the surface to be imaged of the electronic component comes to the in-focus surface of the imaging device according to the measured thickness of the electronic component;
An image acquisition apparatus for electronic parts, comprising:

Images