JP3914061B2 - Component mounting equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a member mounting device for mounting a member such as an electronic component, cream solder, or adhesive resin on a substrate or a component on the substrate, and in particular, alignment of mounting or confirmation of a mounting state, or The present invention relates to a member mounting apparatus provided with an imaging device unit that captures an image for confirming the presence of a substrate.
[0002]
[Prior art]
Various components such as a surface mounter that mounts electronic components on the substrate, a screen printer that prints cream solder etc. in a predetermined pattern on the substrate, and a dispenser that attaches adhesive resin to the mounted components on the substrate. In some cases, the mounting apparatus is provided with an imaging device section for performing mounting position alignment, mounting state confirmation, substrate presence confirmation, and the like.
[0003]
As a sensor device of such an imaging apparatus unit, an area sensor or a line sensor in which minute photoelectric conversion elements are integrated can be used. Further, the imaging device unit may be provided with an illumination device in order to give an appropriate illuminance to the imaging object.
[0004]
[Problems to be solved by the invention]
The recognition of an object to be imaged captured from an imaging device unit is required to have higher accuracy with the recent miniaturization and miniaturization of electronic components and mounting patterns. For high-accuracy recognition, for example, it is necessary to appropriately maintain the illuminance of the imaging target, and thereby obtain imaging data distributed over a wide range within the dynamic range at the output of the imaging device unit. This is because if the image is biased toward the black side or the white side, the image has poor gradation (the image to be captured is not clear), and the image data becomes unsuitable for highly accurate recognition.
[0005]
Therefore, in order to maintain the illuminance of the object to be imaged, it is necessary to make the luminous intensity of the illuminating device constant. In general, however, the illuminating device has a change in luminous intensity with time. For example, an LED (light emitting diode) lamp has many advantages such as small size, power saving, and low cost, but has temperature characteristics peculiar to semiconductors, and its luminous intensity changes over time due to self-heating. Therefore, if no measures are taken, the illuminance of the object to be imaged fluctuates due to the change in luminous intensity, thereby causing a phenomenon in which the gradation of the image captured by the imaging device unit is biased toward the black side or white side.
[0006]
The present invention has been made in consideration of the above-described circumstances, and in a component mounting apparatus that mounts a member such as an electronic component, cream solder, or adhesive resin on a substrate or a component on the substrate, the mounting position It is an object of the present invention to provide a member mounting apparatus provided with an imaging device unit that obtains an image having a gradation that is higher than that in the past for confirmation of alignment, mounting state, or substrate presence.
[0007]
[Means for Solving the Problems]
In order to solve the above-described problems, the present invention provides a substrate support device that can support a substrate in a substantially horizontal posture, and is provided above the substrate support device and moves at least in a horizontal direction on the supported substrate. A member mounting device having a mounting device for mounting a member and an imaging device provided above the substrate support device and imaging the substrate from above, and is provided in connection with the imaging device. A luminance contrast detecting means for detecting luminance from the imaging data obtained by the imaging device and further detecting a luminance contrast which is a difference between a luminance value near the white side peak and a luminance value near the black side ; , arranged in connection to said imaging device, comprising a correction means for correcting the imaging data obtained by the image pickup device using the detected brightness, the correction means, the luminance contrast detection Smaller the luminance contrast detected by stage than the first predetermined value, and the most black side of the vicinity of the luminance value a second predetermined value the resulting imaging data value is larger than the imaging data Is obtained when the brightness contrast is smaller than a third predetermined value and the brightness value near the white side peak of the imaging data is smaller than a fourth predetermined value. Is characterized by magnifying.
[0008]
That is, in this member mounting apparatus, by detecting the brightness contrast that is the difference between the brightness value near the white side peak and the brightness value near the black side from the imaging data obtained by the imaging device. The value of the imaging data is corrected. This is because the illuminance of the imaging object can be detected equivalently by detecting the luminance contrast. Specifically, when the detected brightness is large and the imaging data is biased toward the white side, this corresponds to a state where the brightness is biased toward the white side and the contrast is lowered. Therefore, when the decrease in luminance contrast is detected and the value on the low luminance side, that is, the luminance value near the black side is greater than the predetermined value, it is determined that the illuminance of the imaging object is large. By this determination, the value of the obtained imaging data is reduced and multiplied. Further, when the detected luminance is small and the image data is biased toward the black side, this corresponds to a state where the luminance contrast is lowered due to the bias toward the black side. Therefore, when the decrease in luminance contrast is detected and the value on the high luminance side, that is, the luminance value near the white side peak is smaller than the predetermined value, it is determined that the illuminance of the imaging object is small. The value of the imaging data obtained by this determination is magnified.
[0009]
Therefore, the imaging data can be corrected to follow the illuminance of the imaging object as a result, and can be an image distributed over a wide range within the dynamic range. Therefore, it is possible to obtain an image having gradation as compared with the prior art.
[0010]
In addition, the member mounting apparatus of this invention typically includes a surface mounter (mounter), a screen printer, and a dispenser. Therefore, as "members" in these, in surface mounters, resistors, capacitors, transistors, electronic components such as integrated circuits (ICs), in screen printers, paste-like compositions such as cream solder and resistor paste, in dispensers And coating agents such as adhesive resins and surfactants.
[0011]
The mounting device corresponds to what is generally called a head unit in a surface mounter, and includes, for example, a plurality of suction heads for mounting electronic components. For example, the head unit is configured to be movable in the X-axis (left / right) and Y-axis (front / rear) directions as a whole, and the respective suction heads are moved in the Z-axis (up / down) direction and the R-axis (around the vertical axis) direction. It can be moved up and down or rotated. Thus, the electronic component is sucked from the component feeder and placed at a predetermined position on the substrate.
[0012]
The mounting apparatus corresponds to what is generally called a squeegee unit in a screen printing machine, and includes a squeegee for printing and adhering the paste-like composition to a substrate through through holes (pits) of a screen mask. The squeegee moves, for example, in one direction (both directions) in the left-right direction (X direction) while pressing the screen mask in the front-rear direction (Y direction) linearly. Thereby, the paste-like composition which exists on a screen mask is guide | induced to the board | substrate side through a through-hole.
[0013]
The mounting apparatus corresponds to what is generally called a dispenser head in a dispenser, and includes, for example, a plurality of nozzles for discharging a coating agent. For example, the dispenser head is configured to be movable in the X-axis (left and right) and Y-axis (front-rear) directions as a whole, and each nozzle is configured to be movable up and down in the Z-axis (up and down) direction. Thereby, a predetermined coating agent is applied and adhered to a predetermined position on the substrate.
[0014]
An image pickup apparatus that picks up an image of a substrate from above, for example, confirms the presence of the substrate by recognizing a mark (fiducial mark) on the substrate, accurately detects the support position of the substrate, or onto the substrate after mounting the member. It is provided in order to confirm the member mounting state .
[0015]
Contact name and illuminance, usually refers to a psychophysical quantity based on visibility, including the amount based on the wavelength sensitivity of the imaging device is not limited to this here. Therefore, for example, when the imaging device is an infrared camera, the amount can be set based on the amount of infrared rays. The same applies to the following.
[0016]
According to another aspect of the present invention, there is provided a substrate support device capable of supporting a substrate in a substantially horizontal posture, and a mounting device that is provided above the substrate support device and moves at least in a horizontal direction and mounts a member on the supported substrate. A device-mounted device having an imaging device and an imaging device for imaging the above-described packaging device from below, the luminance being detected from imaging data obtained by the imaging device, connected to the imaging device And a brightness contrast detecting means for detecting a brightness contrast which is a difference between a brightness value near the white side peak and a brightness value near the black side, and is connected to the imaging device and is detected. by using the luminance; and a correcting means for correcting the imaging data obtained by the imaging device, said correction means, the luminance contrast detected by the luminance contrast detection means first place Smaller than the value, and while the value of the luminance in the vicinity of the most black side of the imaging data is reduced multiplying the value of the imaging data to which the obtained is greater than a second predetermined value, the luminance contrast third When the brightness value near the white side peak of the imaging data is smaller than a predetermined value and smaller than a fourth predetermined value, the value of the obtained imaging data is magnified.
[0017]
In this case, an imaging device that images the mounting device from below is provided. In the case of a surface mounter, this imaging device is provided, for example, to accurately detect the position and orientation of an electronic component in a state where the suction head sucks the electronic component. This detection result can be used, for example, to improve mounting position accuracy on the substrate.
[0018]
Also in this case, the value of the imaging data is corrected by detecting the luminance contrast from the imaging data obtained by the imaging device.
[0019]
Also, the present invention provides, as an embodiment, further comprising one to become light reflective object of the imaged object by the imaging device, said correction means, obtained by imaging in advance the light reflective object The predetermined value is determined using the illuminance of the light reflective object.
[0020]
That is, a light-reflective object is imaged under a certain imaging condition in advance, and this imaging data is used as a later reference. This defines the imaging data to a standard predetermined value, corrects the image pickup data on the basis of a predetermined value of this.
[0021]
Accordingly, it is possible to obtain an image distributed over a wide range within the dynamic range following the change in illuminance of the imaging object. Therefore, for example, it is possible to obtain an image with no gradation on the black side or the white side regardless of a change in illumination over time, and a gradation property. Further, since the imaging light reflective object of constant reflectivity in a certain original with imaging conditions, it can be determined the predetermined value by appropriate criteria.
[0022]
Moreover, the present invention further includes, as an embodiment, a light reflective object that is one of objects to be imaged by the imaging device, and the correction unit obtains an image obtained by imaging the light reflective object in advance. further correcting the value of the imaging data obtained on the basis of the illuminance unevenness in the region. In this case, the illuminance variation is a ratio between an average value of illuminance at a plurality of coordinates set in advance in the imaging region and the illuminance at each coordinate.
[0023]
According to the correction, such as this, there exists the illuminance unevenness in the imaging area, even if the span affects the value of the imaging data obtained, corrected by the equivalent imaging and the absence of illumination variation Data can be obtained. In such corrected image data, in addition to ensuring gradation, the fidelity to the object to be imaged is further improved, and it is useful for highly accurate recognition of substrate marks and members. is there.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 are diagrams showing the configuration of a surface mounter to which the present invention can be applied. 1 is a plan view, and FIG. 2 is a front view.
[0025]
As shown in FIGS. 1 and 2, the surface mounter includes a base 1, a conveyor 2, a component supply unit 3, a tape feeder 4, a head unit 5, a head unit support member 6, a Y-axis fixed rail 7, and an X-axis. A guide member 8, a Y-axis servo motor 9, a Y-axis ball screw 10, an X-axis servo motor 11, an X-axis ball screw 12, a fixed camera 15, and a moving camera 16 are provided. The head unit 5 includes a plurality of suction heads 13, a plurality of suction nozzles 14, and a reference reflector 17.
[0026]
On the base 1, a printed circuit board conveying conveyor 2 is disposed, and the printed circuit board P is conveyed on the conveyor 2 and stopped at a predetermined mounting work position by a clamp mechanism (not shown). . Component supply units 3 are arranged on the outer sides of the conveyor 2 in the Y direction. A large number of tape feeders 4 for supplying various components are arranged in the component supply unit 3, and the tape feeders 4 are fixed in a state where they are adjacent and positioned.
[0027]
Each tape feeder 4 is configured such that a tape containing and holding small electronic components such as ICs, transistors and capacitors at predetermined intervals is led out from a reel (not shown). As the tape is picked up, the tape is sent out intermittently.
[0028]
A head unit 5 is provided above the base 1, and the head unit 5 is configured to be movable in the X-axis direction and the Y-axis direction as described below.
[0029]
That is, the support member 6 of the head unit 5 is arranged on the base 1 so as to be movable on the fixed rail 7 in the Y-axis direction, and the head unit 5 moves on the support member 6 along the guide member 8 in the X-axis direction. Supported as possible. The Y-axis servo motor 9 moves the support member 6 in the Y-axis direction via the ball screw 10, and the X-axis servo motor 11 moves the head unit 5 in the X-axis direction via the ball screw 12. It is like that.
[0030]
The head unit 5 is provided with a plurality of suction heads 13 for mounting components. In this example, six suction heads 13 are arranged in a line in the X-axis direction. The suction head 13 can move in the Z-axis direction and rotate around the R-axis (the central axis of the suction nozzle 14) with respect to the frame of the head unit 5, and this lifting and lowering can be performed by a servo motor (not shown). Made. A suction nozzle 14 is provided at the lower end of the Z-axis of each suction head 13, and negative pressure is supplied to each suction nozzle 14 from a negative pressure supply unit (not shown) during component suction. As a result, the component is sucked to the suction nozzle 14 by the suction force.
[0031]
The head unit 5 is further provided with a moving camera 16 having a CCD (charge coupled device) area sensor as an image sensor. The moving camera 16 picks up an image of a mark (fiducial mark) marked on the substrate after stopping at the working position of the printed circuit board P, thereby confirming the presence of the substrate, detecting a deviation from the normal position, and the like. Is to do. The detected deviation from the normal position is used to correct the position of the suction head 13 when the component is mounted on the substrate P by the suction head 13 (this correction value will be described as δ1 as described later). .)
[0032]
In the head unit 5, a reference reflector 17 is disposed outside the arrangement of the suction heads 13. In the reference reflector 17, the surface facing the base 1 has a certain area, and this surface has a diffuse reflection surface with a substantially uniform reflectance. The reference reflector 17 is used to acquire data serving as reference data when an image of a state in which the suction head 13 sucks a component is captured by a fixed camera 15 described later.
[0033]
A fixed camera 15 having a line sensor as an image sensor is provided in each of two locations within the movable area of the head unit 5 and in the vicinity of the component supply unit 3 on the base 1 and in line symmetry with respect to the conveyor 2. . The fixed camera 15 images the suction head 13 after picking up the component from below, detects whether or not the component is accurately picked up by each nozzle 14 from the picked-up data, and further detects the pick-up position deviation. . The detected suction position deviation is used to correct the position of the suction head 13 when the component is mounted on the substrate P by the suction head 13 (this correction value will be described as δ2 as described later).
[0034]
Note that a dedicated illumination unit for illuminating the imaging object may be provided in the vicinity of the cameras 16 and 15 for the moving camera 16 or the fixed camera 15.
[0035]
Next, the control unit of the surface mounter will be described with reference to FIG. FIG. 3 is a block diagram showing the configuration of the control system of the surface mounter as one embodiment of the present invention. In the figure, the same components as those already described are denoted by the same reference numerals. In the illustrated configuration of the control system, there are some parts that are less important as an embodiment of the invention (for example, control of the conveyor 2).
[0036]
As shown in FIG. 3, the control device 30 includes an overall control unit 35, a storage unit 37 therefor, an image processing unit 33, a storage unit 34 therefor, and an interface 32 with a servo device such as an X-axis servo device.
[0037]
Each of the moving camera 16 and the fixed camera 15 has an imaging unit that performs imaging, and an imaging output thereof is supplied and connected to the image processing unit 33. In the above example, the fixed cameras 15 are provided at two locations of the surface mounter, but the other camera is also connected to the control device 30 in the same manner.
[0038]
The interface 32 has connections with an X-axis servo device 43, a Y-axis servo device 44, and a head unit servo device 40 (Z-axis servo device 41,..., R-axis servo device 42,...) As illustrated. The X-axis servo device 43 is configured to include the X-axis servo motor 11 in FIGS. 1 and 2, and the Y-axis servo device 44 is configured to include the Y-axis servo motor 9 in FIG.
[0039]
The overall control unit 35 performs processing for overall control of the operations of the X-axis servo device 43, the Y-axis servo device 44, and the head unit servo device 40. Actually, it may be configured by hardware such as a microprocessor and software such as a control program.
[0040]
The storage unit 37 stores information necessary for processing performed by the overall control unit 35. Information is taken in and out from the overall control unit 35 as necessary.
[0041]
The image processing unit 33 processes imaging data obtained by the moving camera 16 and the fixed camera 15, thereby recognizing information included in the imaging data and supplying the information to the overall control unit 35. Information to be recognized will be described later. Note that the image processing unit 33 can also be substantially constituted by hardware such as a microprocessor and software such as a control program.
[0042]
The storage unit 34 stores information necessary for processing performed by the image processing unit 33. Information is taken in and out from the image processing unit 33 as necessary.
[0043]
The interface 32 outputs a servo control signal generated by processing by the overall control unit 35 to the X-axis servo device 43, the Y-axis servo device 44, and the head unit servo device 40, and these servo devices 43 , 44, 40 for inputting sensor outputs.
[0044]
Next, the operation of the surface mounter shown in FIGS. 1 and 2 by the control system shown in FIG. 3 will be described with reference to FIG. 4 is a flowchart showing an operation flow of the surface mounter shown in FIGS. 1 and 2 by the control system shown in FIG.
[0045]
First, the printed circuit board P on which all components are already mounted by the surface mounter is carried out by the conveyor 2, and the printed circuit board P not loaded with components is newly carried by the conveyor 2 and clamped at a predetermined position (step 51). Then, the mounted list is initialized (step 52). The mounted list is stored and held in the storage unit 37.
[0046]
Next, the moving camera 16 is moved onto the substrate by the X-axis servo device 43 and the Y-axis servo device 44 (step 53). Then, if necessary, the correction coefficient for the imaging data of the mobile camera 16 is acquired (or updated), and the mark on the board is imaged. In a predetermined case, the imaging processing unit 33 performs correction processing based on the correction coefficient for the imaging data. Perform (step 54). A corrected image (however, an image that has not been corrected except in a predetermined case) is referred to as imaging data 1. Details of step 54 will be described later.
[0047]
Next, the image data 1 is processed by the image processing unit 33, and the substrate mark is recognized, thereby detecting and detecting the displacement of the substrate (the X direction, the Y direction, and the θ direction around the axis perpendicular to the XY plane). A mounting position correction value δ1 of each component is obtained from the positional deviation. The correction value δ1 is transferred to the overall control unit 35 and stored / stored in the storage unit 37 (step 55).
[0048]
Next, the integrated control unit 35 examines the mounted list to determine whether there is unmounted data (step 56). If there is no unmounted data, the mounting of all the components is complete, so the processing ends for this board. If there is unmounted data, the overall control unit 35 searches the data and determines the work procedure such as the mounting order (step 57).
[0049]
Next, according to the determined work procedure, the X-axis servo device 43 and the Y-axis servo device 44 are controlled, and the suction head 13 is moved to the component suction position to suck the component (step 58). This component suction is repeated so that the components are sucked by all the predetermined nozzles 14 (step 59). Note that the suction position control of the suction head 13 in this suction operation takes into account the positional deviation of the suction head 13 detected by imaging of the fixed camera 15 described later, and the positional deviation of the suction head 13 with respect to the component is determined. You may carry out by controlling so that it may become small.
[0050]
Next, the head unit 5 is moved onto the fixed camera 15 by controlling the X-axis servo device 43 and the Y-axis servo device 44. In this example, the fixed camera 15 is a line camera, and moves so as to scan the head unit 5 in a direction (X direction) orthogonal to the line direction (step 60).
[0051]
Then, if necessary, after obtaining (or updating) the unevenness correction coefficient from the imaging data of the reference reflector 17, the suction head 13 to which the component is sucked is imaged, and the correction coefficient for the fixed camera 15 is acquired from this imaging data. . Further, in a predetermined case, the image processing unit 33 performs correction processing based on the correction coefficient on the captured image data, and also performs correction processing using the unevenness correction coefficient. This corrected image is set as imaging data 2 (step 61). Details of step 61 will be described later.
[0052]
Next, the imaging data 2 is processed by the image processing unit 33 to recognize the sucked component, thereby detecting the position shift of the suction component, and the mounting position correction value δ2 of each suction component is determined from the detected position shift. It is determined (step 62). The correction value δ <b> 2 is transferred to the overall control unit 35 and stored / stored in the storage unit 37. Then, the overall control unit 35 obtains δ (= δ1 + δ2) as a final mounting position correction value from the correction value δ1 and the correction value δ2 obtained and held as described above, and stores and holds this in the storage unit 37. (Step 63).
[0053]
Next, the X-axis servo device 43 and the Y-axis servo device 44 are controlled to move the suction head 13 to the corrected mounting position and mount the component (step 64). This component mounting is repeated for all predetermined nozzles 14 (step 65). When the mounting of all the predetermined nozzles 14 is completed, the process returns to step 56 and the operation / processing is similarly performed on the unmounted data.
[0054]
Here, “if necessary, obtain (or update) a correction coefficient for the imaging data of the mobile camera 16 and then image a mark on the board, and in a predetermined case, the image processing unit 33 corrects the imaging data based on the correction coefficient. Details of “the step of performing the process” (step 54) will be described with reference to FIG. Figure 5 is a flowchart showing an example of a detailed process of step 54 definitive in FIG.
[0055]
First, the overall control unit 35 determines whether or not a condition for obtaining (or updating) a correction coefficient for the mobile camera 16 is satisfied (step 541). This condition can be set in advance and stored in the storage unit 37. For example, every n printed boards, every time a set time elapses, every time a set number of parts are mounted, every time this surface mounter is activated, every time a voltage supplied to the illumination unit is detected and a change of a certain level or more occurs in the detected voltage, Each time the LED lamp of the illuminating unit is replaced, the condition can be set. If these conditions are not satisfied, the process proceeds to step 543 described later.
[0056]
When the condition is satisfied, the following processing is performed to obtain a correction coefficient. That is, imaging data is obtained by imaging the substrate, and for example, a value obtained by dividing (normalized) the average value in the screen by, for example, the median value of the full scale is obtained and used as a correction coefficient. For example, if the average value is 0.5 and the full scale is 1, the correction coefficient is 1, and if the average value is 0.4 and the full scale is 1, the correction coefficient is 0.8 and the average value is 0.6 and full. If the scale is 1, the correction coefficient is 1.2. The obtained correction coefficient is stored / stored in the storage unit 34 (step 542).
[0057]
Next, the board mark is imaged to obtain imaging data. The captured image data is processed by the image processing unit 33, thereby detecting the luminance of the data (step 543). As a simple method, the luminance can be obtained by obtaining an average value in the screen.
[0058]
Next, it is determined whether or not the detected luminance is within a predetermined range (step 544). If it is within the predetermined range, it is determined that the image of the object to be imaged has an appropriate illuminance and gradation is ensured, and the process is terminated without correcting the image data of the substrate mark.
[0059]
When it is larger than the predetermined range, the illuminance of the object to be imaged is increased from an appropriate range, and the image data of the board mark is corrected on the assumption that image data with poor gradation is obtained. The correction is performed by performing an operation for dividing the imaging data by the correction coefficient. That is, in this case, the correction coefficient should be greater than 1, and the correction is performed by dividing by a value greater than 1, so the imaged data is reduced (step 545).
[0060]
If it is smaller than the predetermined range, the illuminance of the imaging object has decreased from the appropriate range, and the imaging data of the board mark is corrected assuming that imaging data with poor gradation is obtained. The correction is performed by performing an operation for dividing the imaging data by the correction coefficient. That is, in this case, the correction coefficient should be smaller than 1, and the correction is performed by dividing by a value smaller than 1, so that the imaged data is enlarged (step 546).
[0061]
By correcting the image data of the substrate mark as described above, the distribution of each value of the image data has an appropriate spread, and the image data with ensured gradation can be obtained. Therefore, it is possible to recognize the mark from the imaging data 1 with high accuracy in correspondence with the case where the illuminance varies with time.
[0062]
It should be noted that step 545 and step 546 are the same as the actual processing contents to be performed, and are different depending on the correction coefficient value. Therefore, the determination in step 544 is the same as determining whether it is within the predetermined range or out of the predetermined range, and if it is out of the predetermined range, the process of step 545 (= step 546) is the same. The same applies to the case where step 545 and step 546 are referred to in the following description.
[0063]
Next, “if necessary, obtain (or update) a correction coefficient for the imaging data of the mobile camera 16, image a mark on the board, and in a predetermined case, the imaging data is corrected based on the correction coefficient by the image processing unit 33. The details of the “step of performing processing” (step 54) will be described with reference to FIG. FIG. 6 is a flowchart showing another example of detailed processing of step 54 in FIG. In FIG. 6, the same steps as those described in FIG. 5 are denoted by the same reference numerals, and the description thereof is omitted.
[0064]
This example is obtained to use a luminance contrast rather than the luminance to determine that the image intensity also is secured and gradation appropriate for the imaged object. This is because, as already described, the illuminance of the object to be imaged can be detected equivalently by detecting the luminance contrast.
[0065]
To describe the processing procedure, after step 541 or 542, the substrate is imaged, and the brightness contrast is detected in the image processing unit 33 from the obtained imaging data (step 591). The brightness contrast can be detected simply by the difference between the value near the white peak in the screen and the value near the black side.
[0066]
When it is determined that the detected luminance contrast is smaller than the first predetermined value and the value on the low luminance side of the imaging data , that is, the value near the black side in the screen is larger than the second predetermined value In (Step 592), the processing of Step 545 already described is performed on the assumption that the illuminance of the imaging target has increased from an appropriate range and imaging data with poor gradation is obtained. This is because the brightness contrast is smaller than the first predetermined value, it is determined that the image has poor gradation, and it is determined that the gradation deterioration is biased to the white side. 2 is compared with a predetermined value. The first predetermined value and the second predetermined value can be determined experimentally in consideration of the characteristics of the mobile camera 16, for example.
[0067]
Further, if the detected brightness contrast is rather smaller than the third predetermined value, and high-luminance side of the value of the imaging data, that value around white side peak in the screen is determined to be less than the fourth predetermined value In (Step 593), the processing of Step 546 already described is performed on the assumption that the illuminance of the imaging object has decreased from an appropriate range and imaging data with poor gradation is obtained. This is because the brightness contrast is smaller than the third predetermined value, it is determined that the image has poor gradation, and it is determined that the gradation deterioration is biased toward the black side. 4 is compared with a predetermined value. The third predetermined value and the fourth predetermined value can be determined experimentally in consideration of the characteristics of the mobile camera 16, for example. The third predetermined value may be the same as the first predetermined value.
[0068]
Similar to the processing shown in FIG. 5, the processing described above makes the distribution of each value of the imaging data have an appropriate spread, and imaging data in which gradation is ensured can be obtained. Therefore, it is possible to recognize the mark from the imaging data 1 with high accuracy in correspondence with the case where the illuminance varies with time.
[0069]
Next, “if necessary, obtain (or update) the nonuniformity correction coefficient from the imaging data of the reference reflector 17 and then image the suction head 13 to which the component has been sucked. The correction coefficient for the fixed camera 15 is obtained from this imaging data. Further, in a predetermined case, the image processing unit 33 performs a correction process based on the correction coefficient and also performs a correction process using the unevenness correction coefficient on the captured image data (step 61). Will be described with reference to FIG. FIG. 7 is a flowchart showing an example of detailed processing of step 61 in FIG. In FIG. 7, the same steps as those already described are denoted by the same reference numerals, and the description thereof is omitted.
[0070]
First, the overall control unit 35 determines whether or not the condition for updating the reference data is satisfied (step 611). This condition can be set in advance and stored in the storage unit 37. For example, the condition can be set such that a predetermined time has passed since the surface mounter was turned on. If this condition is not satisfied, the process proceeds to step 613 described later.
[0071]
If the condition is satisfied, the process proceeds to step 612 described below. First, the reference reflector 17 is imaged by the fixed camera 15 while moving the head unit 5 to obtain image data d (x, y) of the reference reflector 17. Here, when the reference reflector 17 has a short length in the Y direction, the head unit 5 is stepped in the Y direction and the head unit 5 is moved a plurality of times in the X direction to image the reference reflector 17. Reference image data d (x, y) having a sufficient length in the Y direction can be obtained.
[0072]
The reference reflector 17 has, for example, a uniform diffuse reflectance (that is, gray as a color) that can obtain an appropriate output of the fixed camera 15 that is moderately moderate when captured by the fixed camera 15 in a standard state. is doing. Therefore, the average value Bav of the imaging data d (x, y) of the reference reflector 17 becomes a reference for determining whether the image captured by the fixed camera 15 thereafter is good or bad.
[0073]
Further, along with the acquisition of the average value Bav, an unevenness correction coefficient W (x, y) (= Bav / d (x, y)) for correcting (unevenness correction) the imaging data for each coordinate (x, y) is obtained. Ask. This unevenness correction coefficient corrects an image captured by the fixed camera 15 thereafter for each coordinate (x, y). The above processing is step 612.
[0074]
Next, the suction head 13 to which the component is sucked is imaged to obtain imaging data, and a luminance average value Avd is obtained as the luminance of the imaging data. Further, a value obtained by dividing (normalized) the luminance average value Avd by, for example, the median value of the full scale is obtained, and this is used as a correction coefficient. For example, if the average value is 0.5 and the full scale is 1, the correction coefficient is 1, and if the average value is 0.4 and the full scale is 1, the correction coefficient is 0.8 and the average value is 0.6. If the scale is 1, the correction coefficient is 1.2. The obtained correction coefficient is stored / stored in the storage unit 34 (step 613).
[0075]
The calculation / update of the correction coefficient in step 613 is not performed every time, for example, every n printed boards, every set time, every set number of components, every time this surface mounter is activated, every lighting unit It is also possible to detect the voltage supplied to the power source only when a certain change or more occurs in the detected voltage, or when the LED lamp of the illuminating unit is replaced, etc.
[0076]
Next, it is determined whether or not the detected luminance average value Adv is within a predetermined range with reference to Bav obtained in advance (step 614). If it is within the predetermined range, the illuminance of the object to be imaged has not changed or has changed, and it is very small and the gradation is secured. Transition to processing.
[0077]
If it is larger than the predetermined range, the illuminance of the object to be imaged has increased from an appropriate range, and imaging data with poor gradation is obtained. It is corrected by processing. That is, in this case, the correction coefficient should be greater than 1, and the correction is performed by dividing by a value greater than 1, so the imaged data is scaled down.
[0078]
If it is smaller than the predetermined range, it is assumed that the illuminance of the imaging object has decreased from the appropriate range and imaging data with poor gradation is obtained. It is corrected by processing. That is, in this case, the correction coefficient should be smaller than 1, and the correction is performed by dividing by a value smaller than 1, so that the image data is enlarged.
[0079]
By correcting the image pickup data of the suction head 13 as described above, the distribution of each value of the image pickup data has an appropriate spread, and it is possible to obtain image pickup data in which gradation is ensured. Accordingly, it is possible to contribute to the recognition of the component suction status of the suction head with high accuracy in correspondence with the case where the illuminance varies with time.
[0080]
After the uniform correction processing is performed on the imaging data as described above (or in some cases, the uniform correction processing is not performed), the imaging data of the suction head 13 is then converted into a correction coefficient (unevenness correction) for each coordinate. The coefficient is corrected by W (x, y) (step 615). By this correction, it is possible to obtain imaging data (imaging data 2) of the suction head 13 from which uneven illumination and sensitivity variations of the photoelectric conversion elements of the fixed camera 15 are eliminated.
[0081]
More specifically, the value at each coordinate of the imaging data of the suction head 13 is multiplied by the unevenness correction coefficient W (x, y) corresponding to the coordinate (x, y). W (x, y) is a value proportional to the reciprocal of the imaging data d (x, y) when the reference reflector 17 is imaged, that is, multiplying by W (x, y) means that the reference reflection This is equivalent to obtaining the reflectance of the suction head 13 based on the diffuse reflectance of the body 17. That is, imaging data that eliminates uneven illumination and variations in sensitivity of the photoelectric conversion elements of the fixed camera 15 can be obtained. Therefore, it is possible to obtain imaging data that can recognize the suction state with high accuracy.
[0082]
Next, “if necessary, obtain (or update) the nonuniformity correction coefficient from the imaging data of the reference reflector 17 and then image the suction head 13 to which the component has been sucked. The correction coefficient for the fixed camera 15 is obtained from this imaging data. Further, in a predetermined case, the image processing unit 33 performs correction processing based on the correction coefficient and also performs correction processing using the unevenness correction coefficient in the image data 33 in a predetermined case (step 61). An example will be described with reference to FIG. FIG. 8 is a flowchart showing another example of detailed processing of step 61 in FIG. In FIG. 8, the same steps as those already described are denoted by the same reference numerals, and the description thereof is omitted.
[0083]
In this example, luminance contrast is used instead of luminance to determine that the imaged object has an appropriate illuminance and has a good gradation. This is because, as already described, the illuminance of the object to be imaged can be detected equivalently by detecting the luminance contrast.
[0084]
In the process shown in FIG. 8, step 661 is performed instead of step 613 in FIG. 7, and step 592 and step 593 are performed instead of step 614 in FIG.
[0085]
Step 661 is substantially the same as step 613, and is obtained by adding a process for obtaining the luminance contrast from the imaging data. The essential method is similar to that already described in step 591 of FIG. Steps 592 and 593 are the same as those already described with reference to FIG.
[0086]
Also in the process shown in FIG. 8, as in the process shown in FIG. 7, the suction state can be recognized from the imaging data with high accuracy corresponding to the case where the illuminance changes with time.
[0087]
As described above, in the surface mounter according to the embodiment of the present invention, the imaging data is corrected following the illuminance of the imaging target as a result, and an image distributed over a wide range within the dynamic range can be obtained. Therefore, it is possible to obtain an image having gradation as compared with the prior art.
[0088]
In the above description, the imaging data correction system having the reference reflector 17 is described for the fixed camera 15, and the imaging data correction system having no reference reflector is described for the moving camera 16, respectively. Any of these may be used. That is, a correction system that does not have the reference reflector 17 may be applied to the fixed camera 15, and the movable camera 16 may be a correction system that uses the reference reflector by providing a reference reflector near the substrate. it can.
[0089]
Further, the case where the present invention is applied to a surface mounting machine has been described above, but this can also be applied to a screen printing machine. This will be described below with reference to FIG. FIG. 9 is a front view showing a configuration of a screen printing machine to which the present invention can be applied.
[0090]
As shown in FIG. 9, the screen printing machine 70 includes a squeegee unit 71, a frame support member 77, a squeegee unit moving mechanism 78, a fixed camera 79, mask holding mechanisms 80a and 80b, a printing stage 83, a lifting and rotating unit 84, a table. 85. The squeegee unit 71 includes a forward movement squeegee 72, a backward movement squeegee 73, a frame 74, and air cylinders 75 and 76.
[0091]
A screen mask 81 can be stretched between the mask holding mechanisms 80a and 80b. A substrate 82 can be placed and held on the printing stage 83.
[0092]
The squeegee unit 71 is connected to the frame support member 77 as a whole and supported by the squeegee unit moving mechanism 78 so as to be movable in the X direction. A squeegee 72 for forward movement and a squeegee 73 for backward movement are attached to the frame 74 of the squeegee unit 71, and each of these squeegees 72 and 73 has a linear lower end in the Y direction. The air cylinders 75 and 76 can be moved up and down.
[0093]
When the paste-like composition is printed on the substrate 82 via the screen mask 81 by the squeegee 72 or 73, one of the air cylinders 75 or 76 is moved in accordance with forward movement (right direction in the figure) or backward movement (left direction in the figure). The squeegee 72 or 73 is pressed against the screen mask 81. The squeegee unit 71 moves in the X direction as a whole while maintaining this pressed state. Thereby, the paste-like composition can be printed on the substrate 82.
[0094]
The mask holding mechanisms 80a and 80b sandwich both ends of the screen mask 81 in the X direction. A printing stage 83 on which the substrate 82 is placed and held is moved below the sandwiched screen mask 81 and is fixed at predetermined positions of X, Y, Z, and θ (around an axis perpendicular to the XY plane). obtain.
[0095]
That is, the printing stage 83 can be moved up and down (Z direction) and rotated (θ direction) by the lifting and rotating unit 84, and can be moved in the X and Y directions together with the lifting and rotating unit 84 by the table 85.
[0096]
The moving operation of the lifting / lowering rotation unit 84 and the printing stage 83 will be described. First, the substrate 82 is unloaded and loaded at a position indicated by a one-dot chain line on the right side of the drawing. The unloading is the substrate 82 that has already been printed, and the unloading is the substrate 82 on which printing is to be performed.
[0097]
Next, the printing stage 83 and the lifting / lowering rotation unit 84 on which the substrate 82 is placed and held move on the table 85 to the left solid line position. Then, the lifting / lowering rotation unit 84 moves the printing stage 83 to a predetermined rotational position and a Z-direction position (the one-dot chain line position on the left side of the figure). This results in a printable substrate position. The substrate 82, the printing stage 83, and the like that have finished printing move to the one-dot chain line position on the right side of the drawing by the movement opposite to the above, and the substrate 82 is carried out.
[0098]
In the screen printer 70 having the above-described configuration, a fixed camera 79 is provided above the board carry-out / carry-in position. The function of the fixed camera 79 is to confirm the presence of the substrate and the printing state. For example, the presence of the board can be confirmed by imaging and recognizing the mark marked on the board with the fixed camera 70 as in the case of the surface mounter. Moreover, confirmation of a printing state can be confirmed by imaging and recognizing the printed paste-like composition.
[0099]
In this embodiment, the imaging data is corrected for the fixed camera 79 by the configuration described with reference to FIG. Therefore, also in the screen printing machine, the imaging data of the fixed camera 79 is corrected following the illuminance of the imaging object as a result, and an image distributed over a wide range within the dynamic range can be obtained. Therefore, it is possible to obtain an image having gradation as compared with the prior art.
[0100]
Next, the case where this invention is applied to a dispenser is demonstrated with reference to FIG. FIG. 10 is a front view showing a configuration of a dispenser to which the present invention can be applied.
[0101]
As shown in FIG. 10, the dispenser includes a base 91, a conveyor 92, a head unit 95, an X-axis guide member 98, a Y-axis servo motor 99, an X-axis servo motor 101, an X-axis ball screw 102, and a moving camera 106. To do. The head unit 95 includes a plurality of dispenser heads 93a and 93b and a plurality of nozzles 104a and 104b.
[0102]
A printed circuit board transporting conveyor 92 is disposed on the base 91, and the printed circuit board is transported on the conveyor 92 and stopped at a predetermined adhesion work position by a clamp mechanism (not shown).
[0103]
A head unit 95 is provided above the base 91, and the head unit 95 is configured to be movable in the X-axis direction and the Y-axis direction as described below. That is, a support member (not shown) of the head unit 95 is disposed on the base 91 so as to be movable on a fixed rail (not shown) in the Y-axis direction, and the head unit 95 is placed on the support member in the X-axis direction. The guide member 98 is supported so as to be movable. The Y-axis servo motor 99 moves the support member in the Y-axis direction via a ball screw (not shown), and the X-axis servo motor 101 moves the head unit 95 in the X-axis direction via the ball screw 102. Movement is to be performed.
[0104]
The head unit 95 includes a plurality of dispenser heads 93a and 93b for applying the coating agent. In this example, two dispenser heads 93a and 93b are arranged in a line in the X-axis direction. The dispenser heads 93a and 93b can move in the Z-axis direction with respect to the frame of the head unit 95, and are moved up and down by a servo motor (not shown). Nozzles 104a and 104b are provided at the lower end of the Z-axis of each dispenser head 93a and 93b.
[0105]
The head unit 95 is further provided with a moving camera 106 using a CCD area sensor as an image sensor. This moving camera 106 images the mark on the board after stopping at the working position of the printed circuit board, thereby confirming the presence of the board, detecting the deviation from the normal position, or confirming the dispensed state. And so on. The detected deviation from the normal position can be used to correct the position of the dispenser heads 93a, 93b when the coating agent is deposited on the substrate by the dispenser heads 93a, 93b.
[0106]
Note that a dedicated illumination unit that illuminates the imaging object may be provided in the vicinity of the camera 106 for the moving camera 106.
[0107]
In this embodiment, the imaging data is corrected by the configuration described with reference to FIG. Therefore, even in such a dispenser, the imaging data of the moving camera 106 is corrected following the illuminance of the imaging object as a result, and an image distributed over a wide range within the dynamic range can be obtained. Therefore, it is possible to obtain an image having gradation as compared with the prior art.
[0108]
【The invention's effect】
As described above in detail, according to the member NoSo apparatus of the present invention, the imaging data is corrected by was detected brightness. The correction is performed so that the value of the obtained imaging data is reduced when the detected luminance is larger than the predetermined range, and the obtained imaging data is obtained when the detected luminance is smaller than the predetermined range. The value of is scaled up. Therefore, the imaging data can be corrected to follow the illuminance of the imaging target as a result, and can be an image distributed over a wide range within the dynamic range. Therefore, it is possible to obtain an image having gradation as compared with the prior art.
[Brief description of the drawings]
FIG. 1 is a schematic plan view showing a configuration of a surface mounter to which the present invention can be applied.
FIG. 2 is a schematic front view showing a configuration of a surface mounter to which the present invention can be applied.
FIG. 3 is a block diagram showing a configuration of a control system of the surface mounter according to the embodiment of the present invention.
4 is a flowchart showing an operation flow of the surface mounter shown in FIGS. 1 and 2 by the control system shown in FIG. 3;
5 is a flowchart showing an example of detailed processing in step 54 in FIG. 4;
6 is a flowchart showing another example of detailed processing in step 54 in FIG. 4;
FIG. 7 is a flowchart showing an example of detailed processing in step 61 in FIG. 4;
8 is a flowchart showing another example of detailed processing in step 61 in FIG. 4;
FIG. 9 is a schematic front view showing the configuration of a screen printing machine to which the present invention can be applied.
FIG. 10 is a schematic front view showing the configuration of a dispenser to which the present invention can be applied.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Base 2 ... Conveyor 3 ... Parts supply part 4 ... Tape feeder 5 ... Head unit 6 ... Head unit support member 7 ... Y-axis fixed rail 8 ... X-axis guide member 9 ... Y-axis servo motor 10 ... Y-axis ball screw 11 ... X-axis servo motor 12 ... X-axis ball screw 13 ... Suction head 14 ... Suction nozzle 15 ... Fixed camera 16 ... Moving camera 17 ... Reference reflector 30 ... Control device 32 ... Interface 33 ... Image processing unit 34 ... Storage unit 35 ... Overall Control unit 37 ... storage unit 40 ... head unit servo unit 41 ... Z-axis servo unit 42 ... R-axis servo unit 43 ... X-axis servo unit 44 ... Y-axis servo unit 70 ... screen printer 71 ... squeegee unit 72 ... forward movement Squeegee for time 73 ... Squeegee for reverse operation 74 ... Frame 75, 76 ... Air cylinder 77 ... Frame support member 78 ... Squeegee unit moving mechanism 79 ... fixed cameras 80a, 80b ... mask holding member 81 ... screen mask 82 ... substrate 83 ... printing stage 84 ... elevating and rotating unit 85 ... table 91 ... base 92 ... conveyor 93a, 93b ... dispenser head 95 ... head Unit 98 ... X-axis guide member 99 ... Y-axis servo motor 101 ... X-axis servo motor 102 ... X-axis ball screws 104a, 104b ... Nozzle 106 ... Moving camera

Claims (4)

A substrate support device capable of supporting the substrate in a substantially horizontal posture; a mounting device provided above the substrate support device and moving at least in the horizontal direction to mount a member on the supported substrate; and the substrate An imaging device that is provided above a support device and that images the substrate from above;
A luminance that is provided in connection with the imaging device, detects luminance from imaging data obtained by the imaging device, and is a difference between a luminance value near the white side peak and a luminance value near the black side Luminance contrast detection means for detecting contrast ;
A correction unit that is connected to the imaging device and corrects imaging data obtained by the imaging device using the detected luminance;
The correction unit is configured such that the luminance contrast detected by the luminance contrast detection unit is smaller than a first predetermined value and the luminance value near the black side of the imaging data is larger than a second predetermined value. When the value of the obtained imaging data is reduced and multiplied while the luminance contrast is smaller than a third predetermined value and the luminance value near the white side peak of the imaging data is smaller than a fourth predetermined value. A member mounting device characterized in that the value of the obtained imaging data is enlarged. A substrate support device capable of supporting a substrate in a substantially horizontal position, a mounting device provided above the substrate support device and moving in at least a horizontal direction to mount a member on the supported substrate; An imaging device for imaging the mounting device from below,
A luminance that is provided in connection with the imaging device, detects luminance from imaging data obtained by the imaging device, and is a difference between a luminance value near the white side peak and a luminance value near the black side Luminance contrast detection means for detecting contrast ;
A correction unit that is connected to the imaging device and corrects imaging data obtained by the imaging device using the detected luminance;
The correction unit is configured such that the luminance contrast detected by the luminance contrast detection unit is smaller than a first predetermined value and the luminance value near the black side of the imaging data is larger than a second predetermined value. When the value of the obtained imaging data is reduced and multiplied while the luminance contrast is smaller than a third predetermined value and the luminance value near the white side peak of the imaging data is smaller than a fourth predetermined value. A member mounting device characterized in that the value of the obtained imaging data is enlarged. A light-reflective object that is one of objects to be imaged by the imaging device;
The member mounting according to claim 1 , wherein the correction unit determines the predetermined value using an illuminance of the light reflective object obtained by imaging the light reflective object in advance. Equipment. A light-reflective object that is one of objects to be imaged by the imaging device;
The correction means further corrects the value of the obtained imaging data based on the illuminance variation in the imaging region obtained by imaging the light-reflective object in advance , and the illuminance variation The member mounting apparatus according to claim 1, wherein the member mounting device is a ratio between an average value of illuminance of a plurality of coordinates set in advance in an area and illuminance of each coordinate .

Images