JP3552840B2 - Component mounting device - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a component mounting apparatus that holds components such as electronic components and mounts them on an object such as a printed wiring board.
[0002]
[Prior art]
Electronic components, for example, components such as so-called bare chips, use a component mounting device for mounting on a printed wiring board or a liquid crystal panel. The component mounting device includes a holding head for detachably holding the component. The holding head holds the component and mounts the component at a predetermined position on an object such as a printed wiring board or a liquid crystal panel. I have.
By the way, when a bare chip is electrically connected to a wiring pattern of a liquid crystal panel, for example, it is performed as follows. That is, the bumps (protruding electrodes) of the bare chip are connected to the wiring pattern of the liquid crystal panel (for example, transparent electrode ITO) by thermocompression bonding using, for example, an anisotropic conductive film (ACF). The thickness of the anisotropic conductive film is, for example, about 20 to 30 μm.
In FIG. 12, the holding head 4 holds the bare chip 3, and when the holding head 4 is lowered in the direction of the arrow Z, the pump 3 a of the bare chip 3 is connected to the wiring pattern 2 of the liquid crystal panel 1 via conductive particles . And are electrically connected.
[0003]
[Problems to be solved by the invention]
However, as described above, since the thickness W of the anisotropic conductive film 5 is 20 to 30 μm and the diameter of the conductive particles is very small, 3 to 5 μm, there are the following problems. As shown in FIGS. 12 and 13, when the component holding surface 4 a of the holding head 4 is parallel to the upper surface 6 a of the table 6 holding the liquid crystal panel 1, that is, parallel to the upper surface 1 a of the liquid crystal panel 1. , The pumps 3a, 3a can be reliably electrically connected to the wiring patterns 2, 2 by the anisotropic conductive film 5.
However, as shown in FIG. 14, when the component holding surface 4a of the holding head 4 and the upper surface 6a of the object holding means are not parallel, a gap is formed between the bump 3a on one side and the conductive particles of the wiring pattern 2. As a result, there is a problem that both the bumps 3a, 3a cannot be firmly electrically connected to the wiring patterns 2, 2.
Therefore, in order to measure the parallelism between the component holding surface 4a of the holding head 4 and the upper surface 6a of the table 6, for example, the component holding surface 4a of the holding head 4 is placed on a liquid crystal panel 1 by using a pressure measurement film (not shown). The contact pressure of the component holding surface 4a is indicated by the distribution density and the density of the color by pressing and pressing a pressure paper, for example, a pre-scale (trade name) manufactured by Fuji Photo Film Co., Ltd. It is conceivable to check the inclination. However, this method of checking the inclination of the component holding surface 4a cannot be performed inline in an actual component mounting operation.
[0004]
Further, a method of pressing the component holding surface 4a of the holding head 4 against a high-precision glass plate to check the inclination of the component holding surface 4a based on the appearance of the Newton ring generated on the glass plate is also conceivable. The measuring device is very expensive and in-line is difficult.
SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problem, and has as its object to provide a component mounting apparatus that can securely mount a component such as an electronic component to an object.
[0005]
[Means for Solving the Problems]
According to the present invention, there is provided a component mounting apparatus for holding a component and mounting the component on an object, a holding head for detachably holding the component, an object holding means for holding the object, and a holding head. And a parallelism detecting means for detecting a degree of parallelism of the object holding means with respect to the object. The parallelism detecting means brings the part holding surface of the holding head closer to the object holding means side. A sensor that sequentially contacts a plurality of locations on the component holding surface of the holding head, and a component holding device that sequentially contacts the plurality of locations on the component holding surface of the holding head with respect to the direction in which the component holding surface approaches the object holding means. Position measuring means for sequentially measuring the position of each part of the surface; a plurality of measurement positions on the component holding surface of the holding head obtained by the position measuring means after mounting a predetermined number of components; The parallelism of the component holding surface of the holding head with respect to the object is compared by comparing each of the reference positions of the component holding surface obtained by the position measuring means when the surface is parallel to the object of the object holding means. This is achieved by a component mounting apparatus that includes a confirmation unit for confirming.
[0006]
According to the present invention, the holding head can detachably hold the component. The object holding means holds the object.
The parallelism detecting means detects the parallelism of the object holding means with respect to the object and the component holding surface of the holding head. The sensor of the parallelism detecting means brings the component holding surface of the holding head closer to the object holding means side so as to sequentially contact a plurality of portions of the component holding surface of the holding head. The position measuring means sequentially measures the position of each part of the component holding surface in the direction in which the component holding surface approaches the object holding means when the sensor is sequentially brought into contact with a plurality of positions of the component holding surface as described above. On the other hand, when the component holding surface of the holding head is parallel to the object of the object holding means, a plurality of reference positions of the component holding surface obtained by the position measuring means are obtained.
The checking means compares the measured positions of the plurality of parts on the component holding surface of the holding head obtained as described above with the reference positions of the plurality of parts of the component holding surface obtained in advance, thereby holding the object on the holding object. Check the parallelism of the component holding surface of the head.
In this way, when a predetermined number of components are mounted on the object, the parallelism of the component holding surface of the holding head with respect to the object can be checked at a certain interval. Parts can be securely attached to objects.
[0007]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.
The embodiments described below are preferred specific examples of the present invention, and therefore, various technically preferable limitations are given. However, the scope of the present invention particularly limits the present invention in the following description. It is not limited to these forms unless otherwise stated.
1 and 2 show a preferred embodiment of the component mounting apparatus of the present invention. The component mounting apparatus 10 includes a base 11, a head moving unit 30, an electronic component supply unit 16, a holding head (tool) 20, a stage (object holding unit) 40, a parallelism detecting unit 60, and the like.
[0008]
The base 11 supports the head moving unit 30, the electronic component supply unit 16, the camera 17, the stage 40, and the like.
The head moving unit 30 in FIG. 1 is a moving unit that moves the holding head 20 in the X direction. The head moving means 30 includes the support 9 and the guide member 12 held by the support 9. The motor M of the guide member 12 has a feed screw 12 a, which meshes with a nut 13 a of the electronic component transport device 13. Therefore, by operating the motor M and rotating the feed screw 12a, the electronic component transport device 13 can be moved and positioned in the X direction.
The electronic component transport device 13 includes the holding head 20 described above, and can operate the motor M3 to index the movable body 22 in the r direction. The movable body 22 detachably holds the holding head 20. The electronic component transport device 13 includes a motor M2 and a camera 14. By operating the motor M2, the movable body 22 and its holding head 20 can be moved and positioned in the Z direction.
[0009]
The stage 40 shown in FIGS. 1 and 2 is movable along the guide rails 41, 41. When the motor M4 is operated, the feed screw 42 is rotated. Positioning is possible by moving in the Y direction. The stage 40 mounts an object, for example, a liquid crystal panel or a printed wiring board. For example, in this embodiment, the object is the liquid crystal panel 19.
Note that the X, Y, and Z directions in FIG. 1 described above are orthogonal to each other.
Thus, the holding head 20 of the electronic component transport device 13 sucks and holds the electronic component 18 supplied to the electronic component supply unit 16 and moves in the X direction, and the camera 17 changes the suction state of the electronic component 18. By taking an image, the suction posture of the electronic component 18 held by the holding head 20 is recognized.
Then, the electronic component transport device 13 moves in the X direction, and the camera 14 provided in the electronic component transport device 13 recognizes the alignment mark on the pattern of the liquid crystal panel 19, and Check the component mounting position. Thereby, the holding head 20 of the electronic component transport device 13 mounts the electronic component 18 at the mounting position of the liquid crystal panel 19 (for example, indicated by TM in FIG. 2).
[0010]
FIG. 3 shows the stage 40 of FIG. 1, the electronic component transport device 13 and the parallelism detecting means 60.
The movable body 22 of the electronic component transport device 13 holds the holding head 20 in a replaceable manner. The holding head 20 detachably sucks and holds the electronic component 18 by the operation of the vacuum suction source 77.
As shown in FIGS. 4 and 5, the holding head 20 has a component holding surface 20a, and a suction passage 20b is formed in the center of the component holding surface 20a. The component holding surface 20a is a rectangular flat surface when viewed from below. The component holding surface 20a can suction-hold the upper surface side of the electronic component 18 by the operation of the vacuum suction source 77.
The movable body 22 in FIG. 3 can be moved and positioned in the arrow Z direction by the motor M2. This motor M2 is, for example, a stepping motor. The rotational position of the motor M2 can be measured by the encoder 63. The rotational position of the motor M2 digitally measured by the encoder 63 can be sent to the checking unit 64 of the control unit 100 as a value of the position of the movable body 22 and the holding head 20 in the direction of the arrow Z.
[0011]
The parallelism detecting means 60 includes the checking means 64, the position measuring means 66, and the sensor 68.
The sensor 68 is provided at an end of the stage 40 as shown in FIGS. 3 and 4, and has a contact 68a. The contact 68a faces in the direction of arrow Z. As the sensor 68, for example, a contact sensor that operates when a force required for operation is applied can be employed.
The contact 68a of the contact sensor 68 is a sensor that sequentially contacts a plurality of positions (P1 to P3) on the component holding surface 20a of the holding head 20, as shown in FIGS. When the component holding surface 20a of the holding head 20 is brought into contact with the contact 68a, the motor M2 in FIG. 3 is operated to lower the movable body 22 and the holding head 20 in the direction of arrow Z (downward). This is performed by bringing the component holding surface 20a of the holding head 20 closer to the stage 40 side.
[0012]
The position measuring means 66 in FIG. 3 includes the motor M2 and the encoder 63 described above. The position measuring means 66 sequentially contacts the contact 68a of the sensor 68 with a plurality of parts of the component holding surface 20a of the holding head 20. The measuring means sequentially measures the position of each part of the component holding surface 20a with respect to the direction in which the component holding surface 20a approaches the stage 40. The direction in which the component holding surface 20a approaches the stage 40 is the Z direction (downward) in FIG.
[0013]
As described above, the checking means 64 shown in FIG. 3 measures the measurement positions at a plurality of locations (indicated by P1, P2, and P3 in FIG. 4) of the component holding surface 20a of the holding head 20, and the plurality of locations (in FIG. P1, P2, and P3), the parallelism of the component holding surface 20a with the liquid crystal panel 19, which is the object, is confirmed.
The plurality of reference positions (P1 to P3) refer to the component holding surface 20a obtained by measuring by the position measuring means 66 when the component holding surface 20a of the holding head 20 is parallel to the liquid crystal panel 19 on the stage 40. These are a plurality of positions (P1 to P3).
1 and 3 controls the operations of the motors M1 to M4 and the vacuum suction source 77, receives the ON / OFF signal of the sensor 68 and the image signals of the cameras 14 and 17, and obtains the encoder value of the encoder 63. .
[0014]
Next, an operation example of the above-described component mounting apparatus will be described with reference to FIG.
As described above, the measurement locations on the component holding surface 20a in FIG. 4 are, for example, three locations P1 to P3.
First, when the mounting operation is started as shown in FIG. 9 (step ST1), the holding head 20 shown in FIG. 3 has the component holding surface 20a, the stage 40, and the upper surface 40a of the stage 40 in a state where the electronic component 18 is not mounted. Then, it is confirmed whether or not the upper surface 19a of the liquid crystal panel 19 is parallel.
For example, by pressing the holding head 20 against a normally used pressure measurement film, the contact pressure of the component holding surface 20a is displayed in a color distribution density or shade. In this case, the pressure measurement film is placed on the liquid crystal panel 19 in FIG. By comparing the light and shade of the color obtained by the pressure measurement film with a standard color sample visually, an approximate pressure value at each position of the component holding surface 20a can be known. These pressure values are determined based on, for example, the pressures of the measured values P1, P2, and P3 in FIGS. Thus, the parallelism between the component holding surface 20a of the holding head 20 and the liquid crystal panel 19 is checked.
[0015]
When the parallelism of the component holding surface 20a can be confirmed to some extent, master data is acquired as follows (step ST2 in FIG. 9). That is, by operating the motor M2 of FIG. 1 and the motor M of FIG. 1 and appropriately operating the motor M4 for the stage 40, the contact 68a of the sensor 68 is changed as shown in FIG. At the measurement positions P1, P2, and P3. This situation is shown in FIGS.
Referring to FIG. 6, the component holding surface 20a is lowered in the arrow Z1 direction, and the position P1 of the component holding surface 20a contacts the contact 68a. Similarly, in FIG. 7, the contact 68a contacts the position P2, and in FIG. 8, the contact 68a contacts the position P3.
By sequentially bringing the three positions P1 to P3 into contact with the contact 68a in this manner, the position of each of the positions P1 to P3 in the Z direction can be determined by the confirmation means 64 based on the encoder value from the encoder 63 in FIG. The master data SM1, SM2, SM3 as shown in FIG. Master data SM1 corresponds to position P1, master data SM2 corresponds to position P2, and master data SM3 corresponds to position P3.
[0016]
Next, as shown in step ST3 of FIG. 9, the electronic component transport device 13 of FIG. 1 moves to the electronic component supply unit 16 side, and the holding head 20 sucks the electronic component 18 of the electronic component supply unit 16. Then, the posture of the electronic component 18 is imaged by the camera 17, and then the electronic component transport device 13 moves onto the liquid crystal panel 19 of the stage 40. At this time, based on the result of the camera 17 capturing the attitude of the electronic component 18, the motor M3 operates to correct the orientation of the electronic component 18. Then, when the camera 14 detects the alignment mark of the liquid crystal panel 19, the electronic component 18 can be mounted on the predetermined position of the liquid crystal panel 19 by operating the motor M2.
[0017]
When a predetermined number of such electronic components 18 are mounted on the liquid crystal panel 19, for example, five (steps ST3 and ST4), the process proceeds to step ST5 in FIG. In step ST5 of FIG. 9, it is checked whether or not the parallelism of the component holding surface 20a of the holding head 20 on which, for example, five electronic components have been mounted, to the liquid crystal panel 19 has changed (decreased). That is, as shown in FIG. 4, in a state where the holding head 20 is not holding the electronic component 18 by suction, the contact 68a is brought into contact with the three positions P1 to P3 of the component holding surface 20a of the holding head 20. . This situation is performed in the same manner as shown in FIGS. Thereby, sensor detection data SD1 to SD3 as shown in FIG. 10 are obtained.
These sensor detection data SD1 and SD2 are obtained by giving the encoder value of the encoder 63 in FIG.
[0018]
The confirmation means 64 compares the sensor detection data SD1 to SD3 with the master data SM1 to SM3, respectively, as shown in step ST6 of FIG. As a result of the comparison, as shown in FIG. 10, if the absolute values of the sensor detection data and the master data are within a predetermined allowable value, it is determined that the parallelism of the head is secured. Then, the process returns to step ST3 of FIG. 9 again, and the work of mounting the next predetermined number (for example, five) of electronic components is started.
Otherwise, if the comparison result in FIG. 10 exceeds the predetermined position, it is necessary to adjust the parallelism of the component holding surface 20a of the holding head 20 as shown in step ST7 in FIG. For example, an operator manually adjusts the parallelism of the holding head so that the component holding surface 20 a of the holding head 20 is parallel to the liquid crystal panel 19. When the adjustment of the parallelism is completed, the process returns to step ST5 to acquire the sensor detection data of the component holding surface 20a after the adjustment of the parallelism, and thereafter compares the master data with the sensor detection data. It returns to step ST3.
In this way, the parallelism of the component holding surface 20a of the holding head with respect to the liquid crystal panel 19 can be appropriately adjusted in-line during the component mounting operation. , It can be reliably connected electrically. When the required number of electronic components have been mounted, the mounting operation is completed.
In steps other than the adjustment of the parallelism of the component holding surface 20a of the holding head 20, components can be mounted by automatic operation according to a command from the control unit 100.
[0019]
Next, reference is made to FIG.
FIG. 11 illustrates a method when the motor M2 in FIG. 3 moves the holding head 20 closer to the contact 68a of the sensor 68.
FIG. 11A shows a state in which the component holding surface 20a is sent from the distance L to the contact 68a with a small feed amount FP for M2 such as a stepping motor. That is, the line LN-LN in FIG. 11 indicates the height position of the component holding surface 20a of the holding head 20 in the direction of the arrow Z, and the other lines LN1 and LN1 correspond to the component holding surface 20a and the tip of the contact 68a. Is shown. If the holding head 20 is moved in the direction of the arrow Z (downward) (Z1) by operating the motor M2 with a fine pulse like the feed amount FP, it takes a considerable time to move the distance L.
[0020]
Therefore, in the embodiment of the present invention, for example, the following feeding method of the holding head 20 is adopted.
That is, as shown in FIG. 11 (B), first, the motor M2 sends a large amount of the feed amount BFP according to a command from the control unit 100, and at which feed amount pulse, the component holding surface 20a contacts the contact 68a. The contact point C is obtained. For example, when it is found that the component holding surface 20a has come into contact with the contact 68a by the pulse BFP1 of the third feed amount, next, when the holding head 20 is sent, the holding head 20 is sent from the line LN3 to the contact 68a. I will send it to you.
FIG. 11C shows a state in which the holding head 20 is being sent to the contact 68a by a small feed amount FP from the lines LN3 to LN3. By sending by the feed amount FP, the position P1 at which the component holding surface 20a contacts the contact 68a can be obtained. Similarly, in FIG. 11D, the position P2 at which the component holding surface 20a contacts the contact 68a is detected by sending the sheet at the feed amount FP. In FIG. 11 (E), the position P3 at which the component holding surface 20a contacts the contact 68a can be detected by feeding with the feed amount FP.
In this manner, in the method according to the embodiment of the present invention, the distance L2 for bringing the holding head 20 closer to the sensor 70 can be considerably smaller than the distance L in the conventional method. The measurement time when adjusting the parallelism of the component holding surface 20a of the head 20 to the liquid crystal panel 19 can be reduced.
[0021]
The present invention is not limited to the above embodiment.
In the above-described embodiment, the encoder 63 detects the rotation position of the motor M2 digitally as the position measuring means 66 and sends the digital value to the confirming means 64 to determine the position of the holding head 20 in the Z direction. Detected. Instead of the combination of the encoder 63 and the motor M2, a position measuring device or the like for the Z direction of the holding head 20 using a commonly used laser beam or a commonly used glass scale can be used.
The glass scale is a commercially available scale device utilizing the interference phenomenon of diffracted light, and uses a fine diffraction grating recorded as a hologram for the scale.
[0022]
In addition, as shown in FIG. 4, the contact 68a contacts the component holding surface 20a at three points of the measurement positions P1 to P3. However, the present invention is not limited to this. Of course, the parallelism may be measured.
In FIG. 1, the holding head 20 moves in the X direction, moves in the Z direction, and moves on the stage 40 side in the Y direction. However, the present invention is not limited to this, and the holding head 20 may move in the X, Y, and Z directions, or the stage 40 may move in the X, Y, and Z directions. Alternatively, the holding head 20 may move in any one of the X, Y, and Z directions, and the stage 40 may move along the remaining two axes.
Further, in the above-described embodiment, a liquid crystal panel is taken as an example of an object, but the present invention is not limited to this, and may be, for example, a printed wiring board or an object in another field. The components are not limited to electronic components, but may be components in other fields.
[0023]
【The invention's effect】
As described above, according to the present invention, a component such as an electronic component can be securely mounted on an object.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a preferred embodiment of a component mounting apparatus according to the present invention.
FIG. 2 is an enlarged perspective view showing the vicinity of an electronic component conveying device and the vicinity of a stage of the component mounting device of FIG. 1;
FIG. 3 is a side view showing a parallelism detecting unit, an object holding unit, and the like of the component mounting apparatus of the present invention.
FIG. 4 is a perspective view showing the vicinity of a holding head and a sensor.
FIG. 5 is a bottom view showing a component holding surface of the holding head.
FIG. 6 is a diagram showing a state in which a measurement position P1 of the component holding surface contacts a contact.
FIG. 7 is a diagram showing a state in which a measurement position P2 of the component holding surface contacts a contact.
FIG. 8 is a diagram showing a state in which a measurement position P3 of the component holding surface contacts a contact.
FIG. 9 is a diagram illustrating an operation of the component mounting apparatus and an example of parallelism measurement.
FIG. 10 is a diagram showing a comparative example of sensor detection data obtained in the parallelism measuring step and master data obtained in advance.
FIG. 11 is a diagram showing an example of a holding head feeding method.
FIG. 12 is a side view showing an example in which electronic components are electrically connected to a commonly used liquid crystal panel.
FIG. 13 is an enlarged view showing a part of FIG. 12;
FIG. 14 is a view showing a state in which the electronic component is mounted at an angle as compared with FIG. 13;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Component mounting apparatus, 18 ... Electronic components, 19 ... Object (liquid crystal panel), 20 ... Heating head, 20a ... Component holding surface, 40 ... Object holding means ( Stage), 60: parallelism detecting means, 64: checking means, 66: position measuring means, 68: sensor

Claims (3)

In a component mounting device that holds components and mounts them on an object,
A holding head for detachably holding parts,
Object holding means for holding the object,
A component holding surface of the holding head, and a parallelism detecting unit that detects a parallelism of the object holding unit with respect to the target,
The parallelism detection means is
A sensor for sequentially contacting a plurality of locations on the component holding surface of the holding head by bringing the component holding surface of the holding head closer to the object holding means side;
Position measurement means for sequentially measuring the position of each part of the component holding surface with respect to the direction in which the component holding surface approaches the object holding means when the sensor is sequentially brought into contact with a plurality of parts of the component holding surface of the holding head,
A plurality of measurement positions of the component holding surface of the holding head obtained by the position measuring device after mounting a predetermined number of components, and the position measuring device when the component holding surface of the holding head is parallel to the object of the object holding device. Check means for checking the parallelism of the component holding surface of the holding head with respect to the target object by comparing each of the obtained reference positions of the component holding surface with a plurality of reference positions,
A component mounting apparatus comprising: The component mounting device according to claim 1, wherein the sensor is provided on the object holding unit. The component mounting apparatus according to claim 1, wherein the direction in which the component holding surface approaches the object holding means is a direction in which the component is mounted on the object.

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