CN1533233A - Component mounting method and device - Google Patents

Abstract

A component mounting method and device. The component is picked up by the suction nozzle installed so that it can be rotated and raised and lowered, and the suction offset calculated from the suction posture is corrected, and the component is mounted on the predetermined position of the board. Identify the suction posture of the component, obtain the positional deviation and the angular deviation (step S6), and when the angular deviation is less than or equal to a predetermined value, only the positional deviation is corrected (step S8), and the component is installed. In such a structure, since the suction nozzle is not rotated for angle correction when the suction angle deviation is small, the influence of the eccentricity error of the nozzle center position due to the nozzle rotation is eliminated, thereby improving component mounting accuracy. Furthermore, the mounting performance of electronic components on the substrate can be further improved, and mounting errors of components can be reduced.

Description

Component mounting method and apparatus

technical field

The present invention relates to a component mounting method and device, in particular to a component mounting method and device that use suction nozzles to absorb electronic components such as ICs and install them on specified positions on printed circuit boards.

Background technique

The conventionally known mounting machine (component mounting device) has X-axis and Y-axis orthogonal to each other, and the X-axis components are placed on the Y-axis constituted by guide rails etc. The mounting head moves freely on the X-axis component along the X-axis, so that the mounting head moves on the XY plane.

In this device, the nozzle unit has nozzles for absorbing electronic components, and the nozzle unit as a whole is rotatably mounted on the mounting head, and the nozzle can be moved up and down along the rotation axis of the nozzle unit.

When using such a mounting machine to mount electronic components such as ICs on a predetermined position on a substrate, the mounting head is first moved to the component supply unit, where the suction nozzle is lowered to suction the desired electronic components. Then, while the suction nozzle is raised while the electronic component is being sucked, the electronic component is moved above the component recognition camera by moving the mounting head, and the electronic component is recognized by the component recognition camera there. Here, based on the image captured by the component recognition camera, the amount of adsorption displacement of the electronic component relative to the rotation axis of the suction nozzle component (the positional displacement amount between the component center and the suction center and the suction angle displacement amount) is obtained. The offset amount sets the mounting target position during mounting, that is, the position of the mounting head and the rotation angle of the nozzle member, and simultaneously obtains the correction amount from the target position with respect to each drive unit (Patent Document 1).

After the correction amount is obtained as described above, the mounting head and the nozzle unit are driven by the corrected correction amount, and when the nozzle unit reaches the target position, the nozzle is lowered to mount the electronic component on the substrate.

Patent Document 1 JP-P-5-10746 Gazette (Figure 1)

However, in the above-mentioned installation machine, the central axis of the suction nozzle and the rotation axis of the suction nozzle parts should generally be consistent. However, due to the accuracy of parts or assembly accuracy, etc., as shown in FIG. S is in a slightly inclined state with respect to the rotation axis P of the suction nozzle member 50 in the vertical direction. In this case, at the front end 51a of the suction nozzle 51, since the central axis S of the suction nozzle 51 is eccentric with respect to the rotation axis P of the suction nozzle member 50, when the suction nozzle member 50 is rotated, the front end 51a of the suction nozzle 51 Then, a swing centered on the rotation axis P is formed as shown by the locus Sa in the figure.

Moreover, the distance between the central axis S of the front end portion 51a of the suction nozzle 51 and the rotation axis P of the suction nozzle member 50, the so-called distance, increases as the suction nozzle 51 descends. Therefore, when the suction nozzle member 50 is rotated, the suction The swing of the nozzle 51 also tends to expand as indicated by the locus Sa in FIG. 8( b ). In the state where the suction nozzle 51 is raised, even if the front end portion 51a is coincident with the rotation axis P of the suction nozzle member 50 (not eccentric), the central axis S of the suction nozzle 51 is in the above-mentioned inclined state, even if the suction nozzle member 50 is not rotated. In this case, the position of the front end of the suction nozzle 51 also deviates from the rotation axis P as the suction nozzle 51 descends.

In addition, the above-mentioned eccentricity of the suction nozzle 51 may include twisting elements. That is, there may be cases where the center axis S of the suction nozzle 51 is inclined in a positional relationship that is twisted with respect to the rotation axis P of the suction nozzle member 50. In this case, as the suction nozzle 51 descends, not only The eccentric amount of 51a increases, and the front end 51a of the suction nozzle 51 in the lowered position deviates by an angle θ in the circumferential direction from the front end 51a of the suction nozzle 51 in the raised position.

Therefore, on the premise that the central axis of the suction nozzle and the rotation axis of the suction nozzle part are in a coaxial state, in the state where the suction nozzle is raised, correction processing or offset correction in accordance with the displacement of electronic components is performed. method, if the center of the front end of the suction nozzle is eccentric with respect to the rotation axis of the suction nozzle part or the suction nozzle is inclined, when the electronic component is actually mounted on the substrate, as the suction nozzle rotates or descends, the front end of the suction nozzle will shift. A defect that prevents electronic components from being mounted at predetermined mounting positions on a substrate.

Therefore, in the installation machine, as shown in Figure 8(a) and (b), it is assumed that the center axis of the suction nozzle is eccentric or inclined relative to the rotation axis of the suction nozzle part, or the plane position of the front end of the suction nozzle when the suction nozzle is raised and lowered is also considered. For offset, it is necessary to set the target position during installation. As described in the above-mentioned Patent Document 1 (paragraph 0004), the jig components are mounted on the jig substrate, and the installation error is calculated using a two-dimensional measuring device. This method has the advantage of obtaining comprehensive correction data that can also obtain data for correcting the error amount of the drive system relative to the target position. However, this method has the disadvantage that it can be done when the product is shipped, but it is very difficult to install and set after purchase.

Contents of the invention

The present invention is proposed to solve the above problems, and its purpose is to provide a component mounting method and device that can further improve the mounting performance of electronic components on a substrate, reduce component mounting errors, and mount components in correct positions.

In order to solve the above-mentioned problems, the present invention provides a rotatable and liftable suction nozzle mounted on a mounting head that can move on a horizontal plane to suck up components, and the suction offset calculated according to its suction posture A component mounting method in which the component is corrected and then mounted at a predetermined position on a substrate, in which the amount of positional deviation and the amount of angular displacement are obtained from the suction posture of the component, and the amount of angular displacement If it is less than or equal to the specified value, install the part at the same angle as the suction angle when recognizing the part.

In addition, the present invention provides a rotatable and liftable suction nozzle installed on a mounting head that can move on a horizontal plane to suck up a component, correct the suction offset obtained from its suction posture, and then A component mounting device for mounting the component at a predetermined position on a substrate, the device having a structure including: a component recognition camera that captures an image of the suction component; and recognizing the suction posture of the component based on the image of the component, A means for calculating a positional shift amount and an angular shift amount during suction, and mounts the component at the same angle as the suction angle when the component is recognized when the angular shift amount is equal to or smaller than a predetermined value.

In this structure, when the suction angle deviation is small, the suction nozzle is not rotated for angle correction, so the influence of the error caused by the eccentricity of the nozzle center position when the nozzle is rotated is eliminated, so that the component mounting accuracy can be improved. In addition, by setting the focus point of the component recognition camera on approximately the same plane as the surface of the substrate on which the component is mounted, it is possible to absorb the amount of change in the horizontal plane caused by the rise and fall of the nozzle and improve the mounting accuracy.

Description of drawings

FIG. 1 is a plan view showing the structure of a component mounting device.

Fig. 2 is a front view showing the structure of the component mounting device.

Fig. 3 is a block diagram showing the configuration of a control system of the component mounting device.

Fig. 4 is an explanatory diagram showing, on a plane, the central axis S of the nozzle front end at various angles of the nozzle lowering position with respect to the rotational axis P of the nozzle member.

Fig. 5 is a plan view showing a jig substrate provided with marks in a grid pattern.

Fig. 6 is a flow chart showing the flow of component mounting.

Fig. 7(a) is an explanatory diagram showing when the electronic component is sucked, (b) is an explanatory diagram showing each coordinate position when the electronic component is rotated and moved through the central axis S of the front end, and (c) is an explanatory diagram showing the electronic component is moved to the final target. An overview of the location.

Fig. 8(a) is an explanatory diagram showing a state when the suction nozzle is raised when eccentricity occurs, and (b) is an explanatory diagram showing a state when the suction nozzle of (a) is lowered.

In the figure: 3-base plate; 4-component supply part; 5-mounting head unit; 9-Y-axis servo motor; 15-X-axis servo motor; 17-Z-axis servo motor; 18-R-axis servo motor; 19-base plate Recognition camera; 25-component recognition camera; 37-image recognition device.

Detailed ways

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

FIG. 1 shows a component mounting apparatus 1 for mounting electronic components on a substrate, FIG. 2 shows a part centered on a mounting head unit 5, and FIG. 3 shows a block diagram of a control system configuration. The component mounting apparatus 1 is provided with an X-axis servo motor 15 having a position detector 16 , and a Y-axis servo motor 9 having a position detector 10 . Drive the X-axis servo motor 15 according to the instructions of the control device 60 composed of CPU, RAM, ROM, etc., so that the screw shaft 13 rotates, the mounting head unit 5 supported by the support body 14 moves in the X-axis direction, and drives the Y-axis servo motor. The motor 9 rotates the screw shaft 8, and the support body 14 of the mounting head unit 5 moves along the guide rail 7, whereby the mounting head unit 5 can be moved in the XY direction.

In addition, the mounting head unit 5 also has three suction nozzle members. One nozzle part 20 will be described below, but the other nozzle parts have the same structure (only one nozzle part is shown in FIG. 3 ). The suction nozzle part 20 has a suction nozzle 21 on its central axis and a nozzle holding part 20a around it, and the suction nozzle part as a whole can be rotated around the central axis (R axis) relative to the frame of the mounting head unit 5 by the R-axis servo motor 18 At the same time, the suction nozzle 21 can be moved up and down relative to the nozzle holding member 20a by the Z-axis servo motor 17 (movement in the Z-axis direction). In this case, the moving positions of the Z-axis and R-axis of the adsorption nozzle 21 can be detected by the position detectors 22 and 23 provided on the servo motors 17 and 18, and the moving positions of the X-axis and Y-axis can be detected by the position Detectors 16, 10 perform the detection.

In addition, the component mounting device 1 is also provided with a plurality of component supply units 4 of component supply devices 4a such as a conveyor belt mechanism for accommodating electronic components arranged in parallel. 21 picks up the electronic components and mounts them on the substrate 3 conveyed along the conveyor belt 2 . In this case, there is a mechanical error caused by the moving axis, etc., so that the movement command value from the control device 60 that outputs the movement command to each axis does not necessarily match the actual movement arrival position, and there is an inherent positional deviation at each position on the substrate. , so in order to correct the inherent positional offset, the mounting head unit 5 of the mounting device is equipped with a substrate recognition camera 19, which is used to obtain the inherent offset of each position on the substrate in advance, and perform the calibration operation as described below. . The substrate recognition camera 19 images the substrate mark formed on the substrate 3 , recognizes the position of the mark through image processing, and corrects the positional deviation of the substrate when electronic components are mounted.

On the other hand, between the conveyor belt 2 (upper side in FIG. 1 ) and the component supply unit 4, a component recognition camera 25 for component recognition is provided, and the electronic component is captured by the component recognition camera 25, and the image is captured by the CPU 37a, memory 37b, A/D converter 37c, etc., the image recognition device 37 (FIG. 3) performs processing to recognize the position (suction posture) of the electronic component 62. In this case, the focus point position 25a of the component recognition camera 25 (FIG. 2) is set on the board mounting surface. Specifically, after the electronic component supplied from the component supply unit 4 is sucked by the suction nozzle 21 , the mounting head unit 5 is moved while the suction nozzle 21 is raised, and the suctioned electronic component is kept at a predetermined focus above the component recognition camera 25 . The dot position 25 a (correction position), whereby the electronic component is imaged as an in-focus image by the component recognition camera 25 .

The image of the electronic component captured by the component recognition camera 25 is subjected to image processing in the image recognition device 37 to obtain the amount of suction displacement (positional displacement and angular displacement) of the electronic component relative to the central axis S of the suction nozzle component 20 , the moving position of the rotation axis P of the nozzle member 20 at the time of attachment, that is, the target position of the nozzle member 20 is determined based on the amount of suction displacement.

In addition, as shown in FIG. 3, input devices such as a keyboard 31 and a mouse 32 for inputting board data and part data are provided in the part mounting device, and the generated board data and part data can be stored in a hard disk, flash memory, etc. storage device 33 . In addition, a monitor 34 is provided, and component data, calculation data, and images captured by the board recognition camera 19 and the component recognition camera 25 can be displayed on the screen.

In addition, a memory unit (RAM) is provided in the control device 60 of the component mounting apparatus for storing the eccentric amount of the nozzle center position caused by the rotation posture of the suction nozzle 21, and the rotation posture (0, 90, 180, 270 degrees) The eccentricity of the nozzle center position is pre-datad and stored. That is, in the structure of the component mounting apparatus described above, the front end of the suction nozzle 21 is at the focal point position 25a, the component height at the time of recognition is at substantially the same height position as the surface of the substrate 3, and the suction nozzle component 20 is positioned at the reference angle ( For example, when the rotation angle is 0°), as shown by the dotted line in Figure 4, although the central axis S of the suction nozzle 21 should be consistent with the rotation center P of the suction nozzle part 20, due to component manufacturing errors and assembly errors, the suction nozzle When the central axis S of the suction nozzle 21 is inclined relative to the rotation axis P of the suction nozzle part 20, as shown by the solid line in the figure, the central axis S of the suction nozzle 21 is located at an eccentric distance Nax relative to the rotation axis P of the suction nozzle part 20. , Nay (4th quadrant) position. Therefore, in order to correct the error due to the eccentricity, the eccentricity amount of the height position within 360 degrees is obtained in advance and stored in the storage unit.

In this embodiment, as shown in FIG. 5 , when the device is started or maintained, a jig substrate 41 having calibration measurement points (markers) 42 arranged in a plurality of grids is imaged by a substrate recognition camera 19. The position of each measuring point 42 detected by the imaging is compared with the position data specified by the CAD data to obtain the inherent positional deviation of each mounting position, and store it in the storage unit (RAM) of the control device 60 . As for the position recognition method of the measurement point, the method used in the conventionally known technology is used.

As described above, the target position of the rotation axis P of the suction nozzle part 20 during mounting is determined according to the adsorption deviation of the electronic component relative to the central axis S of the suction nozzle part 20, and the control device 60 calculates according to the determined final target position. Relative to the inherent position offsets of each servo motor 9, 15, 17, 18, add the correction amount of the position offset of the correction substrate and the adsorption offset, drive and control each servo motor 9, 15, 17, 18, and electronically Components 62 are mounted at predetermined substrate positions.

Next, referring to FIG. 7 and referring to the flow chart of FIG. 6, the suction and mounting operations of the electronic components of the above-mentioned mounting machine and the position correction when mounting the electronic components will be described.

First, the mounting operation is started, and the control device 60 reads from the storage device 33 the pre-set data such as the type of electronic component to be mounted or the mounting position, etc., which are suitable for the substrate (step S1), and the mounting operation suitable for the substrate is started. . At this time, the control device 60 resets the counter that is counted up every time an electronic component is mounted (step S2), and at the same time starts driving the conveyor belt 2 for conveying the substrate, whereby the substrate 3 to be mounted is carried in and positioned in a predetermined operation. position, the mounting head unit 5 is moved in the XY direction, the board recognition camera 19 is positioned on a predetermined board mark, and mark position recognition and board position recognition are performed (step S3).

Then, the mounting head unit 5 is moved in the XY direction while the suction nozzle 21 is positioned at a desired electronic component supply position of the component supply unit 4, and then the suction nozzle 21 is lowered to suction the electronic component 62 from the component supply unit 4 ( Steps S4, S5). Then, the suction nozzle 21 rises while the electronic component is sucked, the mounting head unit 5 moves above the component recognition camera 25, the electronic component 62 is arranged at the recognition position (focus point position) 25a of the component recognition camera 25, and the electronic component is held The posture at the time of mounting on the substrate is captured by the component recognition camera 25 at the focal point position. The captured image of the electronic component is subjected to image processing by the image recognition device 37 to obtain the amount of suction displacement, that is, the amount of positional displacement between the component center and the suction center and the angular displacement from the reference angle (step S6).

In addition, the control device 60 sets the mounting position of the electronic component with respect to the substrate 3 based on the rotation axis P of the nozzle member 20 . That is, when picking up an electronic component, it is assumed that the suction nozzle part 20 is held at a reference angle, and that the rotation axis P and the central axis S of the suction nozzle part 20 coincide with the center of the electronic component. The rotation axis P and the rotation angle of the suction nozzle member 20 set the mounting position.

Therefore, when picking up an electronic component, when the rotation axis P of the suction nozzle part 20 and the central axis S of the nozzle 21 coincide with the center Q of the electronic component and the electronic component is picked up at a reference angle, the above-mentioned mounting position and mounting position The moving position of the suction nozzle member 20 (including the moving position in terms of the rotation angle of the suction nozzle member 20 ) is matched. However, as shown in FIG. 7( a ), for example, when the rotation axis P of the suction nozzle member 20 does not coincide with the nozzle center axis S and the center Q of the electronic component 62 and is sucked in a state inclined to the rotation direction, in order to correct The angular offset θ obtained in step S6 is used to rotate the suction nozzle around the rotation axis P for angle correction. Due to the eccentricity of the rotation axis P and the central axis S of the suction nozzle, the distance between the rotation center P and the component center Q The position deviates from the result obtained at the time of recognition in step S6.

That is, in the case where the origin of the component recognition camera is the same as the suction center (S), if the vector from the component center (Q) to the suction center (S) is A=(Ax, Ay), and the vector from the rotation center (P) The vector to the adsorption center (S) is B=(Bx, By), and the vector from the rotation center (P) to the component center (Q) is C=(Cx, Cy), because A is the component recognition result, and B is Known items, so when the suction nozzle is rotated around the rotation center (P) to correct the adsorption angle offset (-θ), the vector from the corrected rotation center (P) to the component center (Q) is C 'for:

C'＝[cos(-θ)·(Ax+Bx)-sin(-θ)·(Ay+By),

sin(-θ)·(Ax+Bx)+cos(-θ)·(Ay+By)]

In addition, in the case where the origin of the part recognition camera and the center of rotation (P) are the same, C is the part recognition result, C=(Cx, Cy), then

C'=[cos(-θ)·Cx-sin(-θ)·Cy,

sin(-θ)·Cx+cos(-θ)·Cy]

After correcting the angle, move the center of rotation P to the position offset by C'.

It can be considered that if the amount of displacement of the suction angle is small and the correction angle θ is a sufficiently small value, then the displacement of the suction center S from the rotation center P is sufficiently small by the correction angle. Therefore, it is judged in step S7 whether or not the angular shift amount θ is smaller than a predetermined value. In the case of less than or equal to the specified value, in order to avoid the fluctuation of the positional offset caused by the above-mentioned angle correction, the angular offset obtained in step S6 is not corrected, only the positional offset is corrected, and the final target is performed. Position setting (step S8). In this case, the nozzle is not rotated in order to correct the angle, so the component is mounted at the component suction angle at the time of component recognition, that is, at the same angle as the inclination angle relative to the reference angle, and the nozzle rotation position caused by the nozzle rotation position can be eliminated. The influence of the error caused by the eccentricity of the center position. In addition, when recognizing a part, the tip of the suction nozzle 21 is located at the focal point position 25a of the part recognition camera 25, and the height of the part is at approximately the same height as the surface of the substrate 3, so the amount of change in the level caused by the rise and fall of the nozzle can also be absorbed. .

On the other hand, if the angular deviation is greater than the predetermined value, after correcting the angular deviation θ, the above-mentioned positional deviation of C' is corrected to set the final target position (step S9). Thereby, the final target position of the rotation axis P of the nozzle member 20 is determined, and the inherent positional displacement amount of a drive system is corrected (step S10). Figure 7(b) and (c) respectively show the coordinate values after correcting the angle, the final target coordinate (position) of the rotation center, the target coordinate and the logical target coordinate after correcting the intrinsic position offset.

When the target position is set in this way, the mounting head unit 5 moves in the XY direction by driving the drive units through the control device 60, and the nozzle member 20 moves to the final target position while rotating while performing angle correction. When arriving at this final target position, suction nozzle 21 descends at this position, and electronic component is installed on the substrate, after electronic component is installed, at the specified moment, the electronic component counter of control device is counted up (steps S11, S12) ).

Under the situation that component mounting is not all completed, return to step S4, carry out the same processing (step S13), on the other hand, after all component mounting is completed, drive conveyer belt 2, the substrate that will be positioned at predetermined work position is carried out, for example Transport to the subsequent process (step S14), and end this flow.

Invention effect

As described above, according to the present invention, when the suction angle deviation is small, the suction nozzle is not rotated in order to correct the angle, so the influence of the error caused by the eccentricity of the nozzle center position during the nozzle rotation is eliminated, so that the component mounting can be improved. precision. In addition, by setting the focus point of the component recognition camera on the same surface as the surface of the substrate on which the component is mounted, it is possible to absorb the amount of change in the horizontal plane caused by the rise and fall of the nozzle and improve the mounting accuracy.

Claims (4)

1. component mounting method, utilization is installed in can be in the rotatable and liftable adsorption mouth on the installation head that moves on the horizontal plane, parts have been adsorbed, the absorption side-play amount of obtaining according to its absorption posture is proofreaied and correct, then these parts are installed in assigned position on the substrate, it is characterized in that

Obtain position offset and angular deflection amount according to the absorption posture of described parts,

In described angular deflection amount during smaller or equal to setting, the identical angle installing component of absorption angle with identification component the time.

2. component mounting method according to claim 1 is characterized in that, the component height during the absorption posture of identification component is and the roughly the same height of substrate surface.

3. apparatus for mounting component, utilization is installed in can be in the rotatable and liftable adsorption mouth on the installation head that moves on the horizontal plane, parts have been adsorbed, the absorption side-play amount of obtaining according to its absorption posture is proofreaied and correct, then these parts are installed in assigned position on the substrate, it is characterized in that having:

The component identification video camera that described adsorption element is made a video recording; With

According to the absorption posture that the image of described parts comes identification component, the position offset during computing absorption and the unit of angular deflection amount,

In described angular deflection amount during smaller or equal to setting, the identical angle installing component of absorption angle with identification component the time.

4. apparatus for mounting component according to claim 2 is characterized in that, the component height during the absorption posture of identification component is and the roughly the same height of substrate surface.

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