CN1960622B - Correction method of head position of component mounting device and dummy nozzle - Google Patents

Abstract

The present invention provides a head position correction method and a dummy nozzle of a component mounting device, which can accurately identify the actual offset between the board recognition camera and the head position in simple steps, and perform appropriate correction. Install the dummy nozzle (32) on the head (14n), and use the OCC camera (second camera) (26) equipped on the holder (12) with the head (14n) to identify the VCS on the side of the base (10) The position of the camera (first camera) (20), according to the design offset (On) of the OCC camera (26) and the head (14n), move the head (14n) to the identified VCS camera (20) position, use the VCS camera (20) to photograph the mark (36) of the virtual nozzle (32) at the position after the movement, thereby the deviation (OnR) of the head (14n) after the movement from the center of the VCS camera (20) Obtained as an offset correction amount.

Description

Correction method of head position of component mounting device and dummy nozzle

technical field

The present invention relates to a method of correcting the head position of a component mounting device and a dummy nozzle suitable for use in the correction.

Background technique

For example, Patent Document 1 discloses a component mounting apparatus for mounting electronic components such as ICs, LSIs, flip chips, resistor chips, and chip capacitors at predetermined positions on a substrate. This component mounting apparatus has a head having a nozzle for vacuum-adsorbing these components, and the direction of the X-Y direction (horizontal driving) and the Z-axis direction (vertical driving) of the head (specifically, a holder for holding the head) are combined. Combination of movement and the head's own rotation around the Z axis (theta drive), and the parts supplied to the parts feeder (partsfeeder) are mounted on the substrate,

In such a component mounting apparatus, if the position of the nozzle on the X-Y plane recognized by the control device deviates from the actual position of the nozzle, the mounting accuracy of the component on the board will of course be impaired. The position of the head (nozzle) can be judged based on the imaging result of the camera (the second camera in the present invention) for substrate recognition mounted together on the holder (holder) on which the head is mounted. There is a predetermined distance (offset offset) between the camera and the actual head, so if the offset changes from a preset value due to thermal expansion of the holder itself, etc., as a result, it will be recognized by the control device. There is a deviation between the head position and the actual head position.

Therefore, in the component mounting apparatus of this patent document 1, this offset amount is corrected as follows. First, the mark formed on the base side of the mounting device is configured to be movable forward and backward, and aligned with the center of the chip recognition camera (the first camera in the present invention). Then, the board recognition camera is moved from the origin of the X-Y plane to the design predetermined values X1, Y1 that can be expected to enter the field of view of the board recognition camera, and the board recognition camera is used to capture images to obtain the actual initial position of the mark. Location MXO, MYO. Next, the mark is also observed with a chip recognition camera to detect initial positions MCXO and MCYO. Afterwards, the mark is retracted from the field of view of the camera for chip recognition, and the head to be calibrated is moved from the origin by predetermined values X2 and Y2 in design, and guided to the camera for chip recognition, and the initial position NX0 of the nozzle on the camera for chip recognition is obtained. , NYO.

When performing calibration, perform the same operation as above, and obtain respective differences ΔX1=MX1-MX0, ΔX2= NX1-NXO, ΔY1=MY1-MYO, ΔY2=NY1-NYO. ΔX=ΔX1+ΔX2 and ΔY=ΔY1+ΔY2 are the obtained correction amounts.

In addition, this patent document 1 also discloses a structure as another embodiment in which the mark located at the center of the camera for chip recognition has deviated by observing how much (MCX0 → MCX1) the mark has shifted when the operation is judged, and the amount of change is (described as "positional deviation due to variation in cylinder operation") is added to the calculation of the above-mentioned deviations ΔX and ΔY observed by the substrate recognition camera.

[Patent Document 1] Japanese Patent No. 3129134

However, in the method of correcting the head position of the component mounting apparatus in the above-mentioned Patent Document 1, there are very many types of positional relationships to be considered, and any positional relationship must be judged by observing the time-varying operation. Because of the correction amount, as a result, two sets of information of various types are required both before operation and at the time of judgment, and there is a problem that the steps for judgment are complicated.

In addition, when observing the nozzle of the head with a camera for chip recognition, it is extremely difficult to actually accurately identify the center of the nozzle. From this point of view, it cannot be said that the accurate head (axis center) can be detected. Location.

Contents of the invention

The present invention was made to solve the existing problems, and the object of the present invention is to provide a head that can directly and accurately recognize the amount of displacement between the camera for board recognition and the actual head position in simple steps, and can perform appropriate correction. The correction method of the position and the dummy nozzle used in the correction method.

A head position correction method of a component mounting device according to the present invention, wherein the component mounting device absorbs a component using a nozzle mounted on a head movable in an X-Y direction on a base, arranges the component on a substrate, and places the component on a substrate. The mounting device has a first camera configured on the base and a second camera that is movably assembled on the base together with the head, and the calibration method includes: a first step (step 54), The dummy object of the nozzle is assembled on the head, that is, the inspection jig (dummy nozzle) whose center in the X-Y direction is marked; the second step (step 56), using the second camera to identify the first the center position of the camera; a third step (step 64) of moving the head to the position identified in the second step, taking into account the design offset between the second camera and the head to be corrected The center position of the first camera; and the fourth step (step 76), using the first camera to photograph the mark of the inspection jig at the moved position, thereby aligning the moved head with the second A shift of the center of a camera is detected as a correction amount for a designed shift amount between the second camera and the head, thereby solving the above-mentioned problem.

In the present invention, the inspection jig on which the center of itself is first marked is prepared as a dummy nozzle. This is because the center of the head (nozzle) can be grasped more accurately. Next, the first camera (chip recognition camera described later) arranged on the base side (chip identification camera described later) is confirmed by the second camera (substrate recognition camera described later: equivalent to an OCC camera) mounted movably on the base together with the head. Use a camera: equivalent to a VCS camera) at the center of the moment. Then, the head is moved to the center position of the first camera identified in the above steps, taking into account the (known) design offset between the second camera and the head to be calibrated. That is, in order that the head to be calibrated just comes to the center of the first camera, the second camera is moved to a position where a designed offset is calculated based on the center position of the first camera actually grasped by the second camera itself. . The second camera uses its own lens to accurately "measure" the existing position of the first camera. Therefore, when using the first camera to photograph a dummy nozzle, if the mark of the dummy nozzle deviates from the imaging center of the first camera, the deviation can be understood as the actual offset relative to the design difference between the second camera and the head. The offset produced the deviation. Therefore, by detecting this deviation as a correction amount, it is possible to directly and accurately recognize the amount of deviation between the second camera and the head at the current moment.

The amount of displacement between the camera for board recognition and the actual head position can be directly and accurately recognized with simple steps, and appropriate correction can be performed.

Description of drawings

FIG. 1 is a flowchart showing a control flow of a method of correcting a head position of a mounting device according to an example of an embodiment of the present invention.

FIG. 2 is a schematic block diagram showing a main part of a mounting device A to which the above-mentioned calibration method is applied.

Fig. 3 is a schematic front view and a bottom view of a dummy nozzle used in carrying out the above calibration method.

FIG. 4 is a flow chart showing a flow of control for determining a trigger for performing the correction of the correction method described above.

FIG. 5 is a flowchart showing a main part control flow of a partially modified example of FIG. 4 .

Detailed ways

An example of an embodiment of the present invention will be described in detail below with reference to the drawings.

As shown in FIG. 2 , the electronic component mounting device A to which the present invention is applied has a so-called gantry type XY driving mechanism, and the XY driving mechanism has an X axis 2 and a Y axis 4, and is held in a base 10. The device (cage) 12 is movable in the X-Y direction. Heads 14 (14-1, ... 14-4) are installed on the holder 12, and nozzles 16 (16-1, ... 16-4) attached to the heads 14 are used to absorb components (not shown). The components are arranged at predetermined positions on the substrate 18 placed above the base 10 . In this embodiment, four heads 14 - 1 to 14 - 4 are attached to one holder 12 . For convenience, the head to be calibrated is denoted by 14n, and the nozzle is denoted by 16n.

On the base 10 of the mounting apparatus A, a VCS camera (camera for chip identification: first camera) 20 for detecting the suction state of components, a nozzle replacement unit 22 and a calibration block 24 are provided. Furthermore, an OCC camera (substrate recognition camera: second camera) 26 is attached to the holder 12 in addition to the head 14 . The VCS camera 20 is marked with camera marks (VCS marks) 20 a and 20 b for making the OCC camera 26 confirm the position of the VCS camera 20 .

In the present embodiment, when the mounting device is activated, the marks (measurement points) provided on the calibration block (not shown) are photographed by the OCC camera 26, and the X-Y position of each mark detected by the photograph is compared with a predetermined position. The positional data is obtained to obtain the inherent positional deviation of the mounting device A, and is stored in a control device not shown. For the position recognition itself using the mark of the calibration block, a conventionally known method is used.

Through the recognition operation by the OCC camera 26 using the mark of the calibration block, the X-Y position of the holder 12 relative to various units (for example, the VCS camera 20, the nozzle replacement unit 22, etc.) mounted on the base 10 is determined. Coordinates are corrected. Then, the marks 18a, 18b drawn on the substrate 18 to be mounted are imaged by the same OCC camera 26, thereby correcting the X-Y coordinates of the holder 12 with respect to the mounting coordinates. The (design) relative distances (design offsets 01, . . . 04 of the heads 14-1, . . . Acquired in advance as a parameter at the time of assembly, when positioning each head 14n (any one of 14-1 to 14-4) at the target coordinates, the offset amount of the head 14n to be used relative to the OCC camera 26 On is added to the X-Y coordinate value of the OCC camera datum. Then, the correction of the offset On is performed through the steps shown in FIG. 1 at an appropriate timing described later.

Here, a dummy nozzle (a jig for inspection) 32 used for this calibration is shown in FIG. 3 .

The dummy nozzle 32 is configured to have the same shape as a normal nozzle (not shown) between the head 14n and the pickup portion (mounting mechanism) 34, and can be mounted on the head 14n in exactly the same manner as a normal nozzle. However, in order to sufficiently function as a jig, a clear mark 36 is drawn at a position corresponding to its own center in the X-Y direction (that is, the axis center of the head 14n) instead of the suction port. In addition, for example, there is a eaves portion 38 painted green in the vicinity of the center in the Z-axis direction to further improve the visibility of the mark 36 . In general, it is difficult to clearly determine the center of the nozzle in terms of its function of absorbing the component. It is more difficult to determine the axis of the head 14n in the state where the nozzle is not assembled. Therefore, in the present invention, the dummy nozzle 32 as a dedicated jig is purposely attached to the head 14n, and the center thereof can be easily identified by the mark 36.

Next, the procedure for correcting the offset will be described in detail using FIG. 1 .

First, in step 52 (shown as S52 in FIG. 1 , the same below), the holder 12 is moved to the position where the nozzle replacement unit 22 is stored, where the nozzles previously assembled on the head 14n (to be calibrated) will be replaced. To remove, the dummy nozzle 32 as a jig shown in FIG. 3 is taken out from the nozzle replacement unit 22 and replaced and assembled (step 54 ). This replacement is performed automatically in the same manner as normal nozzle replacement, based on instructions from a control device (not shown).

After the dummy nozzle 32 is assembled, the positions of the camera marks (VCS marks) 20a, 20b formed on the VCS camera 20 are recognized by the OCC camera 26 on the holder 12 (step 56). In this installation device A, VCS marks 20a, 20b are marked at two positions on the diagonal line of the VCS camera 20, respectively, so the OCC camera 26 recognizes the positions of these two VCS marks 20a, 20b, and uses the middle point to identify . Determine the center position 20c of the VCS camera 20 . Next, proceeding to step 58, the head 14n to be calibrated is moved to the center position 20c of the VCS camera 20 identified in step 56 in consideration of the design offset On (step 58).

After the movement, in step 60 , the head 14n is lowered along the Z axis (axis center of the head 14n ), and the height is set to a height at which the mark 36 of the dummy nozzle 32 can be imaged. After the descent is completed, the θ axis of the head 14n is rotated to a position of 0 degrees (step 62), and the mark 36 of the dummy nozzle 32 is photographed by the VCS camera 20 (step 64). Then, in steps 66 to 76, the θ axis of the head 14n is rotated/stopped every 90 degrees, and the mark 36 is imaged by the VCS camera 20 at each position. As a result, a total of four images are obtained, so the process proceeds to step 78, and the rotation center of the head 14n (real axis center of the head 14n) is calculated based on the trajectory obtained for the marker 36 . As a result, even if the dummy nozzle 32 is mounted with a slight deviation from the real axis of the head 14n, the real axis of the head 14n can be reliably obtained (step 76).

Here, the OCC camera 26 identifies and determines the actual position of the VCS camera 20 based on its own imaging data, and moves the holder 12 for holding the OCC camera 26 to a position deviated from the known, OCC position relative to the design. The position of the offset On between the camera 26 and the head 14n, so it can be said that the calculated deviation from the center of the real axis and the center of the VCS camera 20 directly reflects the (known) design offset On actual deviation. Therefore, in step 90, this deviation ΔOn is the correction amount of the offset On, and On+ΔOn is acquired as the actual offset OnR.

However, in this calibration, in order to maintain high accuracy (calibration precision), the dummy nozzle 32 as a dedicated jig is attached to the head 14n. Therefore, measurement for calibration needs to be performed with as few timings as possible without hindering production. From this point of view, since mounting apparatus A always mounts predetermined nozzles on the head 14n except during substrate conveyance, measurement for calibration is performed during substrate conveyance, and it is preferable to finish measurement during substrate conveyance as much as possible. However, since the original nozzle replacement may occur during the substrate transfer, it is difficult to always end the measurement during the substrate transfer. Therefore, instead of measuring every time a substrate is transported, the elapsed time from the reference time set at specific intervals, the number of substrates produced (number of processed sheets) ), at least one of the specific position at the time of the previous measurement, or the temperature change of the component is used as a parameter, and the above-mentioned program for correction is executed when these parameters exceed the set value. Which parameter is used as a reference to start the program can be set in advance by the user.

FIG. 4 shows a control flow for determining the measurement timing for performing this correction. In step 100, when it is confirmed that the production of a specific substrate has been completed, the transfer of the next substrate is started (step 102). At the same time, the control flow goes to step 104, where it is judged whether the reference parameter set by the user is "time". When it is a time reference, go to step 106 to judge whether the elapsed time from the reference time has exceeded the set value, and when it is judged to have exceeded the set value, go to step 108 to obtain the actual offset OnR of the head 14n.

On the other hand, when the reference parameter set by the user is "number of production sheets", the process proceeds from step 104 to step 112, and at step 114 it is judged whether the number of production sheets has reached the set value. Until the set value is reached, the previous flow is repeated, and when the set value is reached, the process proceeds to step 116 to acquire the actual offset OnR of the head 14n. In addition, in step 118, the count of the number of sheets produced is cleared.

When the reference parameter set by the user is the "temperature" of a specific position or part, go through steps 104 and 112 and enter step 120, where it is judged that the temperature change has exceeded the set value, and the actual temperature of the head 14n is obtained in step 122. Offset OnR. And, in step 124, the temperature at the time of obtaining the actual offset is stored. Also, when the reference parameter is set to "temperature", when the temperature drops for some reason, the offset amount obtained in advance at a specific temperature can be reused under the same temperature condition.

FIG. 5 shows an example of another embodiment to which this reuse is applied.

Fig. 5 further considers practicality, changes the part of steps 108, 116, 122 in Fig. 4 (the part of frame A1 in Fig. 4) into frame A2, most of which are the same as the steps in Fig. 4 except frame A1 → frame A2. Therefore, the same step numbers are assigned to the steps that are substantially the same as those in FIG. 4 .

In the control flow of Fig. 5, when it is judged that the temperature change has exceeded the set value in step 120 (that is, when it is judged that the condition related to the temperature change is established), the detection of the deviation (acquisition of the actual offset OnR) is not immediately entered. ), and first, in step 170, it is judged whether there is a detected value already taken under the same condition for the deviation.

When there is no detected value, in step 122, the actual offset OnR of the head 14n is obtained, and it is confirmed that the temperature at this time is within the practical temperature range (step 172), and then the obtained (detected) actual offset is The displacement OnR is stored as the detected value of the actual displacement OnR of the temperature (step 174).

As a result, in step 170, when it is determined that there is a detected value under the same temperature condition, the detection of the actual offset OnR is not performed again, and the detected value can be reused (steps 122, 172, 174 are skipped). .

On the other hand, when it is determined in step 106 that the elapsed time from the reference time has exceeded the set value, and when it is determined in step 114 that the number of sheets produced has reached the set value, the same method as in the previous embodiment is adopted, Enter steps 108 and 116 respectively to obtain the actual offset OnR of the head 14n. However, in this embodiment, it is confirmed that the temperature at this time is within the practical temperature range (when updating, it is between the actual offset OnR acquired this time and the actual offset OnR (detected value) already acquired at this temperature. (difference within the normal range) (steps 180, 182), newly store or update (rewrite) the obtained actual offset OnR as the detected value of the offset at the temperature.

By performing such a control flow, each time the actual offset value OnR is acquired under a condition deemed appropriate, the data is stored or updated as a detected value at that temperature, and the frequency of actual offset detection can be gradually reduced. As a result, the influence on productivity can be gradually reduced, and the data itself can be sequentially replaced with the closest data with high reliability.

In addition, in this embodiment, as shown in steps 172 , 180 , and 182 , when the obtained actual offset OnR is stored and saved as a detected value, it is assumed that the temperature at that time is within the practical temperature range. And, when updating (rewriting) the detected value, the condition is that the difference between the actual offset OnR acquired this time and the actual offset OnR (detected value) already acquired at the temperature is within the normal range. This is because "inappropriate detected values" are prevented from being saved due to the influence of temporary disturbances. However, this confirming step (S172, S180, S182) is not necessarily a step. Especially when the number of stored detected values is small after the operation starts, these steps can be freely omitted, or the threshold for judging the normal range can be relaxed.

In addition, in the above-mentioned embodiment, the axis center of the head 1 can be accurately obtained even when the dummy nozzle is mounted obliquely by rotating the dummy nozzle around the axis of the head to obtain the center. However, in the present invention In this case, this step is not absolutely necessary, and the mark may be directly read without rotating the dummy nozzle. In addition, even in the case of rotation, it is not necessary to perform reading every 90 degrees, as long as it is less than 120 degrees (more than 3 times), the rotation axis center of the determination head 14n can be eliminated to eliminate the influence of inclined mounting. In addition, needless to say, the more times of imaging, the more accurate information can be obtained.

Furthermore, in the above-mentioned embodiment, the user has adopted a configuration in which the measurement of the actual offset amount is performed when the conditions are met, but the present invention does not have any idea on how to set the trigger for the measurement for the correction. special limited. The trigger may also be set based on parameters other than the above parameters, or may be set in combination with the above parameters. For example, a trigger may be set when the number of sheets to be processed exceeds a predetermined value and the temperature change exceeds a set value.

It can be applied to the correction of the amount of misalignment between the second camera and the head of a mounting device for mounting various components. In addition, the dummy nozzle is not limited to this calibration method, and it can be used at any time when it is necessary to accurately measure the center of the head (nozzle).

Claims (9)

1. the bearing calibration of a position of an apparatus for mounting component, described apparatus for mounting component utilization be assemblied in pedestal upper edge X-Y direction movably the head on nozzle come adsorption element, with this component configuration on substrate, described apparatus for mounting component have first camera that is configured on the described pedestal and with described first second camera of assembling movably on described pedestal, the bearing calibration of a position of described apparatus for mounting component is characterised in that

Described bearing calibration comprises:

First step, the dummy of the described nozzle of assembling is the inspection anchor clamps that self center of described X-Y direction is labeled on described head;

Second step utilizes described second camera to discern the center of described first camera;

Third step, consider described second camera and the described head that will proofread and correct between design on side-play amount, this is moved to the center of first camera that identifies in described second step; And

The 4th step, locational described inspection after utilizing described first camera to move is with the described mark of anchor clamps, thus after will moving this from departing from of the center of described first camera detect for described second camera with described between design on the correcting value of side-play amount.

2. the bearing calibration of a position of apparatus for mounting component as claimed in claim 1, wherein,

In described the 4th step,

Make described head around its axle center rotation, and along the circumferential direction take the described mark of 3 described inspections at least with anchor clamps,

By axle center, detect described departing from according to this resulting this mark of image pickup result more than 3 times.

3. the bearing calibration of a position of apparatus for mounting component as claimed in claim 2, wherein,

Carry out 4 shootings on the described circumferencial direction altogether every 90 degree in a circumferential direction.

4. the bearing calibration of a position of apparatus for mounting component as claimed in claim 1 is characterized in that,

Among the certain location when elapsed time during with the production number of described substrate, from benchmark, the mensuration of last time or the variations in temperature of parts at least one is as parameter, when these parameters reach condition more than the set point and set up, carry out the described detection that departs from.

5. as the bearing calibration of a position of any described apparatus for mounting component in the claim 1～4, it is characterized in that,

When the variations in temperature of certain location the during mensuration of last time or parts reaches the above condition of set point and sets up at least, carry out the described detection that departs from, and,

The condition that this variations in temperature is relevant is set up and is carried out described departing from when detecting, this detected departing from as the detected value that departs under this temperature stored,

After temperature conditions when identical, do not depart from detection once more, and utilize this detected value again.

6. the bearing calibration of a position of apparatus for mounting component as claimed in claim 5 is characterized in that,

Installed and when predetermined condition is set up, also carried out the described program that departs from detection, and when this predetermined condition is set up, no matter whether the existence of described detected value, all depart from detection, wherein, this predetermined condition is that the variations in temperature of described certain location or parts reaches the above condition of set point condition in addition, and

This predetermined condition is set up and has been carried out described departing from when detecting, and this detected departing from as the detected value that departs under this temperature is newly stored, or detectedly depart from the detected value that renewal has been stored with this.

7. the bearing calibration of a position of apparatus for mounting component as claimed in claim 5 is characterized in that,

When the detected value stored of the conditioned disjunction of temperature in the applied temps scope of this moment and the difference of this obtained detected value are controlled at predetermined value with at least one side establishment among the interior condition, carry out the storage of described detected value.

8. the bearing calibration of a position of apparatus for mounting component as claimed in claim 6 is characterized in that,

When the detected value stored of the conditioned disjunction of temperature in the applied temps scope of this moment and the difference of this obtained detected value are controlled at predetermined value with at least one side establishment among the interior condition, carry out the storage or the renewal of described detected value.

9. nominal nozzle, described nominal nozzle is used for the bearing calibration of claim 1, and described nominal nozzle is characterised in that,

Described nominal nozzle can be installed on the head of apparatus for mounting component, the nozzle that described apparatus for mounting component utilization is assemblied on the movably described head of pedestal upper edge X-Y direction comes adsorption element, with this component configuration on substrate, described nominal nozzle has the mark of expression from the center on described X-Y direction, and has as being used to discern the function of the inspection of the position of described head on described X-Y direction with anchor clamps.

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