JP4986760B2 - Surface mount equipment - Google Patents

Description

  The present invention relates to a surface mounting apparatus, and more particularly, to a surface mounting apparatus that reduces the burden of mounting position correction in a surface mounting apparatus including a plurality of mounting heads.

  FIG. 1 is a plan view showing a conventional surface mounting apparatus 10 having two mounting heads. The surface mounting apparatus 10 has a dual gantry configuration in which mounting heads 12 and 14 for mounting electronic components movable in a plane are assembled to the X-axis support members 16 and 18, respectively. The mounting heads 12 and 14 are provided with recognition cameras 12C and 14C, respectively.

  The mounting head 12 includes a main body portion 12A, a suction mounting portion 12B including a suction nozzle, and a camera 12C, and the suction mounting portion 12B and the camera 12C are attached to the main body portion 12A. The main body 12A is supported by an X-axis support member 16, and the mounting head 12 having the main body 12A can be moved in the X-axis direction by a ball screw 16A driven by an X-axis servomotor 16B. Both ends of the X-axis support member 16 are supported by a Y-axis support member 22 installed on the base 20, and can be moved in the Y-axis direction by a Y-axis ball screw 22A driven by a Y-axis servo motor 22B. It is like that. Therefore, the mounting head 12 can move in the XY plane.

  The mounting head 14 includes a main body portion 14A, a suction mounting portion 14B including a suction nozzle, and a camera 14C, and the suction mounting portion 14B and the camera 14C are attached to the main body portion 14A. The main body 14A is supported by an X-axis support member 18, and the mounting head 14 having the main body 14A can be moved in the X-axis direction by a ball screw 18A driven by an X-axis servomotor 18B. Both ends of the X-axis support member 18 are supported by a Y-axis support member 22 installed on the base 20, and can be moved in the Y-axis direction by a Y-axis ball screw 22C driven by a Y-axis servo motor 22D. It is like that. Therefore, the mounting head 14 can move in the XY plane.

  In the surface mounting apparatus 10, the printed circuit board 24 is conveyed by a conveyor 26 and fixed in the surface mounting apparatus 10. The mounting heads 12 and 14 can mount components on the printed circuit board 24 simultaneously or alternately.

  Conventionally, when an electronic component is mounted on a printed circuit board 24 in a surface mounting device, before mounting the component, in order to increase mounting accuracy on the printed circuit board 24 regardless of whether the number of mounting heads is singular or plural. In addition, a plurality of reference marks 24A provided on the printed circuit board 24 are recognized by a recognition camera provided in the mounting head to recognize the fixed position of the printed circuit board 24, and the mounting position is corrected to replace the electronic component with the printed circuit board 24. I am trying to put it on.

  The surface mounting apparatus 10 that has been described has a dual gantry configuration as described above and includes two mounting heads 12 and 14. For this reason, the recognition cameras 12C and 14C provided in the mounting heads 12 and 14 respectively recognize a plurality of reference marks 24A provided on the printed circuit board 24, and correct the mounting positions in the mounting heads 12 and 14, respectively. Thus, electronic components were mounted on the printed circuit board 24.

  In addition, as described in Patent Document 1, in the mounting position correction method, a plurality of recognition marks are provided in the apparatus in addition to the reference mark 24A provided on the printed circuit board 24, and the plurality of recognition marks are read. There is also a method of correcting the mounting position by calculating an expansion coefficient due to thermal expansion of the drive shaft.

JP-A-8-18289

  However, in the conventional surface mount apparatus 10 having a dual gantry configuration, the recognition cameras 12C and 14C of the two mounting heads 12 and 14 respectively read the reference mark 24A of the printed circuit board 24, and each time the printed circuit board 24 is changed. It is necessary to recognize the reference mark 24A of the printed circuit board 24 by the recognition cameras 12C and 14C of the two mounting heads 12 and 14, respectively. Has been an obstacle to increasing the productivity when the is mounted on the printed circuit board 24.

  The mounting position correction method described in Patent Document 1 is a method of calculating an expansion coefficient due to thermal expansion of the drive shaft and correcting the mounting position based on the obtained expansion coefficient. However, it does not contribute to increase the productivity when electronic components are mounted on a printed circuit board in a surface mount apparatus having a dual gantry configuration.

  The present invention has been made in view of such problems, and provides a surface mount apparatus for a multi-gantry having a plurality of mounting heads, which improves productivity when mounting electronic components on a substrate. Is an issue. As a matter of course, the multi-gantry surface mounting apparatus includes a dual gantry surface mounting apparatus including two mounting heads.

  The present inventor has found that the above-mentioned problems can be solved by the following means, and has reached the present invention.

That is, the multi-gantry surface mounting apparatus according to the present invention includes a plurality of mounting heads each including a camera, and each of the plurality of mounting heads mounts an electronic component on a printed circuit board on which a reference mark is marked. In the surface mount device, the height of the printed circuit board held when the electronic component is mounted is approximately the same as the height of the printed circuit board , and is recognized by the cameras provided in the plurality of mounting heads. A plurality of common recognition marks used to obtain a difference between the results, a calculation unit that performs a calculation based on a result of the recognition of the plurality of common recognition marks and the reference mark by the camera, and holds a result of the calculation And a control unit for correcting the electronic component mounting position on the printed circuit board based on the result of the calculation, By performing the recognition of the serial reference mark by one of the cameras, without recognizing the reference mark by the other of the camera, the other the cameras only recognize the plurality of common recognition mark, the plurality of The mounting position of the electronic component on the printed circuit board is corrected in all the mounting heads.

  According to the present invention, since the plurality of common recognition marks are provided at the same height as the height position of the printed circuit board held when the electronic component is mounted, the recognition of the reference marks on the printed circuit board is performed by the plurality of mounting heads. By using one camera mounted on one of the mounting heads, the electronic component mounting position on the printed circuit board can be found on all of the mounting heads without recognizing the reference mark by the cameras of the other mounting heads. Can be corrected.

  Therefore, in the mounting operation by the multi-gantry surface mounting apparatus, the time other than the component mounting can be shortened, and the productivity when mounting the electronic component on the substrate can be improved.

  Hereinafter, embodiments according to the present invention will be described in detail with reference to the drawings. However, the same components as those of the conventional surface mounting apparatus 10 are denoted by the same reference numerals, and description thereof is omitted.

  FIG. 2 is a plan view showing the surface mounting apparatus 50 according to the embodiment of the present invention. This surface mount device 50 is different in appearance in that two common recognition mark portions 52 and 54 are provided in the conventional surface mount device 10. The two common recognition mark portions 52 and 54 are provided in the vicinity of the transport conveyor 26 on the base 20 and at positions that do not hinder the movement of the printed circuit board 24 transported on the transport conveyor 26. .

  The common recognition mark parts 52 and 54 are obtained by marking the common recognition marks 52B and 54B on the upper surfaces of the pile-like parts 52A and 54A. The shape of the pile-like portions 52A and 54A is a pile-like shape having a horizontal cross section of about 20 mm × 20 mm and a height of about 200 mm, made of steel, and is surface-treated in black. The common recognition marks 52B and 54B are circles having a diameter of about 1 to 2 mm, and are formed by embedding white ceramic in the upper surfaces of the pile-shaped portions 52A and 54A. The height of the pile-shaped parts 52A and 54A is about 200 mm in order to match the height position of the common recognition marks 52B and 54B with the height position of the printed circuit board 24 held when the electronic component is mounted. Note that the shape of the common recognition marks 52B and 54B does not have to be a circle, but may be any shape that can recognize the center coordinates (for example, the center of gravity position) (for example, a regular triangle or a square).

  The mechanism by which the mounting heads 12 and 14 can move in the XY plane is the same as that of the conventional surface mounting apparatus 10 and will not be described.

  Next, a control block diagram shown in FIG. 3 shows a configuration in which the common recognition marks 52B and 54B are recognized by the cameras 12C and 14C mounted on the mounting heads 12 and 14, and the surface mounting apparatus 50 is controlled based on the recognition result. Will be described.

  The surface mounting apparatus 50 includes a control device 60 that controls the mounting heads 12 and 14, the X-axis servomotors 16B and 18B, and the Y-axis servomotors 22B and 22D. The control device 60 includes a control unit 62, a calculation unit 64, an image processing unit 66, and a storage unit 68.

  The image processing unit 66 performs predetermined image processing on the image data of the common recognition marks 52B and 54B recognized by the cameras 12C and 14C, and outputs the processed image data to the calculation unit 64. The calculation unit 64 performs a predetermined calculation based on the input image processing result, and outputs the calculation result to the control unit 62. The control unit 62 instructs the servo motors 16B, 18B, 22B, and 22D based on the input calculation result, corrects the mounting position, and then instructs the suction mounting units 12B and 14B to perform the electronic component. Is mounted on the printed circuit board 24. The storage unit 68 stores the calculation result obtained by the calculation unit 62.

  Next, the operation of recognizing the common recognition marks 52B and 54B by the cameras 12C and 14C mounted on the mounting heads 12 and 14 and controlling the surface mounting apparatus 50 based on the recognition result is shown in FIGS. A detailed description will be given in accordance with an actual mounting operation using a flowchart.

  Here, in the stage before the operation according to the flowcharts shown in FIGS. 4 and 5, the camera 12 </ b> C mounted on the mounting heads 12 and 14 before the surface mounting device 50 is assembled at the factory and shipped. 14C, the common recognition marks 52B and 54B are recognized, the image processing unit 66 performs predetermined image processing, the calculation unit 64 performs predetermined calculation, and the calculation result is the storage unit 68 of the control device 60 of the apparatus main body. Are stored as default values (initial values).

Conserved operation result (specified value (initial value)), the coordinates of the common recognition mark 52B which is recognized by the mounting head 12 (X _1252-0, Y _1252-0) and, 54B of the coordinates (X _1254-0 , Y _1254-0 ) and the angle θ _12-0 formed by the straight line connecting the coordinate positions of the recognized common recognition marks 52B and 54B and the X axis, and the coordinates of the common recognition mark 52B recognized by the mounting head 14 ( X _1452-0 , Y _1452-0 ), 54B coordinates (X _1454-0 , Y _1454-0 ), and the angle formed by the straight line connecting the recognized coordinate positions of the common recognition marks 52B, 54B and the X axis θ _14-0 . The angle θ _12-0 can be calculated by θ _12-0 = tan ⁻¹ ((Y _1254-0 −Y _1252-0 ) / (X _1254-0 −X _1252-0 )), and the angle θ _{14− 0} can be calculated by θ _14-0 = tan ⁻¹ ((Y _1454-0 −Y _1452-0 ) / (X _1454-0 −X _1452-0 )).

  Before the surface mounting apparatus 50 is shipped to the factory where the electronic components are mounted and the electronic components are actually mounted, first, steps S1 to S5 in FIG. 4 are performed. It is confirmed whether or not an abnormality has occurred in a part related to the coordinate system of the mounting apparatus 50 (for example, X-axis, Y-axis support member, X-axis, Y-axis ball screw, etc.).

Specifically, to recognize a common recognition mark 52B, 54B by the mounting head 12, the coordinate position of the common recognition mark 52B (X _1252-1, Y _1252-1) and the coordinate position of the common recognition mark 54B (X _1254-1 , Y _1254-1 ) is stored in the storage unit 68 of the control device 60 (step S1), the common recognition marks 52B and 54B are recognized by the mounting head 14, and the coordinate position ( _X1452-1 ) of the common recognition mark 52B is recognized. , Y _1452-1) and the coordinate position of the common recognition mark 54B (X _1454-1, stores the Y _1454-1) in the storage unit 68 (step S2).

Then, an angle θ _12-1 formed by the straight line connecting the coordinate positions of the common recognition marks 52B and 54B based on the recognition result by the mounting head 12 and the X axis is calculated by the calculation unit 64, and based on the recognition result by the mounting head 14. An angle θ _14-1 formed by a straight line connecting the coordinate positions of the common recognition marks 52B and 54B and the X axis is calculated by the calculation unit 64 (step S3). The calculation formulas for calculating the angles θ _12-1 and θ _14-1 are the same as the calculation formulas for calculating the angles θ _12-0 and θ _14-0 before shipping.

Next, the coordinate positions (X _1252-1 , Y _1252-1 ) and (X _1254-1 , Y _1254-1 ) of the common recognition marks 52B and 54B based on the recognition result by the mounting head 12 are specified values (initial values). _Compared with (X _1252-0 , Y _1252-0 ), (X _1254-0 , Y _1254-0 ), the angle θ _12-1 is compared with the specified value (initial value) θ _12-0 and the mounting head 14 based on the recognition results of the common recognition marks 52B and 54B based on the recognition results of 14 ( _X1452-1 , _Y1452-1 ) and ( _X1454-1 , _Y1454-1 ) as specified values (initial values) ( _X1452-0 ) , Y _1452-0 ) and (X _1254-0 , Y _1254-0 ), _whether the angle θ _14-1 is within the standard value compared with the specified value (initial value) θ _14-0 The control unit 62 determines whether or not (Step S4).

  If it is not within the standard value, a message indicating an abnormal value is displayed on the display unit of the device body to stop the operation of the device (step S5), and the product is returned to the assembly factory for repair or delivered by an engineer. Visit the previous parts mounting factory for repairs. If it falls within the standard value, the electronic component mounting operation (steps S6 to S13 in FIG. 5) can be continued.

  Conventionally, this check has not been performed, and even if the result of recognizing the printed circuit board 24 is incorrect, whether the printed circuit board 24 is in a poorly fixed state or whether an abnormality has occurred in a portion related to the coordinate system of the surface mounting device 50. I couldn't judge.

Next, in the mounting operation of the electronic component, first, the difference between the recognition result of the common recognition marks 52B and 54B by the mounting head 12 and the recognition result of the common recognition marks 52B and 54B by the mounting head 14 is calculated as an arithmetic unit of the apparatus main body. 64 (step S6). Specifically, the difference (relative error) between the recognition result by the mounting head 12 and the recognition result by the mounting head 14 is obtained for the coordinate positions of the common recognition marks 52B and 54B. Further, a difference (relative error) between the angle θ _12-1 and the angle θ _14-1 is obtained.

  Next, the printed circuit board 24 is transported to the mounting position by the transport conveyor 26 and fixed (step S7). Then, the reference mark 24A of the printed circuit board 24 fixed at the mounting position is recognized only by the mounting head 12 (step S8).

  Based on the recognition result of the reference mark 24A on the printed circuit board 24 by the mounting head 12 and the recognition result of the common recognition marks 52B and 54B by the mounting heads 12 and 14 (relative error calculated in step S6), the calculation unit 64 performs a calculation. Based on the calculation result, the control unit 62 corrects the mounting coordinate position with respect to the printed circuit board 24 in each of the mounting heads 12 and 14 (step S9). The mounting head that has recognized the reference mark 24A of the printed circuit board 24 in step S8 is only the mounting head 12, and the mounting head 14 does not recognize it, but the recognition results of the common recognition marks 52B and 54B by the mounting heads 12 and 14 ( (Relative error calculated in step S6) is obtained, so that the mounting coordinate position with respect to the printed circuit board 24 is also corrected in the mounting head 14 by recognizing the reference mark 24A of the printed circuit board 24 only by the mounting head 12. Can do.

  In step S9, after the mounting coordinate position with respect to the printed circuit board 24 is corrected in each of the mounting heads 12 and 14, an electronic component is mounted on the printed circuit board 24 by the mounting heads 12 and 14 according to an instruction from the control unit 62. This is done (step S10).

  It is determined whether or not the mounting of the electronic component on one printed circuit board 24 is completed (step S11). When the mounting of the electronic component on the printed circuit board 24 is completed, the printed circuit board 24 is surface-mounted by the transport conveyor 26. It carries out to the exterior of the apparatus 50 (step S12). If the mounting of the electronic component on the printed circuit board 24 is not completed, the process returns to step S10, and the mounting of the electronic component on the printed circuit board 24 by the mounting heads 12 and 14 is continued.

  In step S12, after the printed circuit board 24 after the electronic component mounting is completed is carried out of the surface mounting apparatus 50, it is determined whether or not the electronic components have been mounted on all the printed circuit boards 24 on which the electronic component is to be mounted. (Step S13) When the mounting of the electronic components on all the printed circuit boards 24 is completed, the series of mounting operations is completed. If the mounting of the electronic components on all the printed circuit boards 24 is not completed, the process returns to step S7 to start mounting the electronic components on the new printed circuit board 24.

  The embodiment described above is a dual gantry surface mounting apparatus having two mounting heads, but the number of mounting heads may be plural, and the surface mounting of a multi gantry having three or more mounting heads. It is good also as an apparatus.

Plan view showing a conventional surface mounting apparatus having two mounting heads The top view which shows the surface mounting apparatus which concerns on embodiment of this invention Control block diagram of the surface mounting apparatus The first half of a flowchart showing the operation of the surface mounting apparatus Second half of flowchart showing operation of surface mount device

Explanation of symbols

DESCRIPTION OF SYMBOLS 10, 50 ... Surface mount apparatus 12, 14 ... Mounting head 12A, 14A ... Main-body part 12B, 14B ... Adsorption mounting part 12C, 14C ... Camera 16, 18 ... X-axis support member 16A, 18A ... X-axis ball screw 16B, 18B ... X-axis servo motor 20 ... Base 22 ... Y-axis support member 22A, 22C ... Y-axis ball screw 22B, 22D ... Y-axis servo motor 24 ... Printed circuit board 24A ... Reference mark 26 ... Conveyor conveyor 52, 54 ... Common recognition mark section 52A 54A ... Pile-shaped part 52B, 54B ... Common recognition mark 60 ... Control device 62 ... Control part 64 ... Calculation part 66 ... Image processing part 68 ... Storage part

Claims (1)

In a multi-gantry surface mounting apparatus that includes a plurality of mounting heads each equipped with a camera, and each of the plurality of mounting heads mounts an electronic component on a printed circuit board on which a reference mark is marked,
Provided at a height position similar to the height position of the printed circuit board held at the time of electronic component mounting , recognized by the cameras provided in each of the plurality of mounting heads, and the difference between the recognition results of each of the cameras A plurality of common recognition marks used to determine the
A calculation unit that performs a calculation based on a result of recognizing the plurality of common recognition marks and the reference mark by the camera;
A storage unit for holding the result of the operation;
Based on the result of the calculation, provided with a control unit for correcting the electronic component mounting position on the printed circuit board,
By recognizing the reference mark by one camera, the other cameras only recognize the plurality of common recognition marks without recognizing the reference mark by the other cameras . A multi-gantry surface mounting apparatus for correcting mounting positions of electronic components on the printed circuit board in all of the mounting heads.

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