JPH08148895A - Electronic component mounting device - Google Patents

Abstract

PURPOSE: To provide an electronic component mounting device, which makes narrow its visual field to a small-sized electronic component and can shorten a read time for the electronic component. CONSTITUTION: An electronic component mounting device is provided with a main scanning direction processing part A, which compares the number of times of a transfer command signal, which is outputted, with a variable setpoint given equivalently to the length of the visual field of the device in a subscanning direction in an image developed in an image processing part 48, a subscanning direction processing part B, which outputs a processing completion signal within the visual field to the processing part 48 when the variable setpoint becomes a variable setpoint given the number of times of the transportation command signal, and a control means C, which gives a variable setpoint set so as to vary large and small values according to the size of an electronic component 15 to the processing part B.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic component mounting apparatus capable of reading an image of an electronic component at high speed.

[0002]

2. Description of the Related Art In most of the electronic component mounting apparatuses at present, electronic components picked up from a parts feeder are
Before mounting on an object such as a board or a lead frame, observation is performed using a camera, a positional deviation with respect to an ideal position is obtained by an image processing unit, and this positional deviation is corrected and then mounted on the object. Here, as this camera, two-dimensional images are read, and one-dimensional images are read in the main scanning direction orthogonal to the moving direction of electronic parts, and the read one-dimensional images are accumulated in the sub-scanning direction. There are two of them, which are made into two dimensions, but in the present invention, the latter is targeted.

Prior to addressing the problems of the prior art, the operating principle of the one-dimensional CCD camera will be described.
5 and 6 are operation explanatory views of a conventional one-dimensional CCD camera. In FIG. 5, reference numeral 1 is a one-dimensional CCD camera, and of the one-dimensional CCD camera 1, 2 is set so as to be orthogonal to the moving direction of the electronic component, and is a photosensitive member that accumulates electric charges according to the intensity of the received light. The photosensitive element array 3 in which elements are juxtaposed in a line is provided with elements corresponding to each photosensitive element one to one,
A shift register to which the charges of the photosensitive element array 2 are transferred,
Reference numeral 4 denotes a shift gate which permits or prohibits the transfer from the photosensitive element array 2 to the shift register 3. Normally, the shift gate 4 prohibits transfer, and charges are accumulated in each photosensitive element. When the shift gate 4 inputs the transfer command signal, the charges of the respective photosensitive elements are transferred to the corresponding elements of the shift register 3 at once. Then, the charges transferred to the shift register 3 are synchronized with the clock signal and output from the output unit 5 to 1
The image signals are individually output.

If the charge of each photosensitive element of the photosensitive element array 2 is A ₁ , A ₂ , ..., A _n-1 , A _n, it is assumed that the shift gate 4 inputs a transfer command signal. The charges A ₁ , A ₂ , ..., A _n-1 , A _n are transferred to the shift register 3 at a time, and thereafter, image signals are sequentially output in synchronization with the clock signal as shown by an arrow N1 in FIG. To be done. Here, as shown in FIG. 6, consider the state before the output of all image signals is completed. At this time, if the shift gate 4 inputs the transfer command signal, the charge mixing occurs in the element on the output section 5 side of the shift register 3 and a completely random value is output. In particular,
In the state of FIG. 6, new charges B ₁ , B ₂ , ..., B _n-1 , B _n are accumulated in the photosensitive element array 2,
If the shift gate 4 permits the transfer, the charge A _n and the charge B ₅ ,
The charge A _n-4 and the charge B ₁ are mixed. Therefore, the shift gate 4 cannot be opened by issuing the transfer command signal until the output of all the charges of the shift register 3 is completed. This means that the output timing of the image signal is determined by the number of elements of the shift register 3 (that is, the number of photosensitive elements of the photosensitive element array 2) and the clock.

[0005]

In recent years, electronic parts having a very large size have also appeared. FIG. 7 is an explanatory diagram showing a relationship between an electronic component and a visual field set in the conventional electronic component mounting apparatus. In FIG. 7, S1 shows an image of a large-sized electronic component (for example, large QFP), and S2 shows an image of a small-sized electronic component (for example, square chip). As shown in FIG. 7, even if the large-sized electronic component is slightly displaced, the edge portion of the large-sized image S1 also has the field of view V1.
The width of the photosensitive element array 2 is extremely wide so as to enter the area. Therefore, due to the reasons described above, the processing time for one line in the main scanning direction is long, and the length Y1 in the sub scanning direction is also made large in order to accommodate large-sized electronic components. Therefore, in the conventional electronic component mounting apparatus, even when capturing an image of a small-sized electronic component, the reading time is the same as when capturing an image of a large-sized electronic component, so that the small-sized electronic component is mounted on the board. There was a problem that the time became unnecessarily long.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an electronic component mounting apparatus capable of reducing the image reading time when mounting a small-sized electronic component and mounting at high speed.

[0007]

SUMMARY OF THE INVENTION In an electronic component mounting apparatus of the present invention, a large number of photosensitive elements are arranged in a line in the main scanning direction, and a photosensitive element array is accumulated in each photosensitive element of the photosensitive element array. A shift register to which electric charges are transferred, a shift gate that permits or prohibits the transfer of electric charges from the photosensitive element array to the shift register, and the electric charges transferred to the shift register are sequentially output as image signals at a timing of a clock signal or an integral multiple thereof. A one-dimensional CCD camera having an output unit for outputting to an image processing unit, and a photosensitive element array in which a main scanning direction is set in a direction intersecting with a moving direction of a mounting head, and a shift gate Main scanning direction processing unit that outputs a transfer command signal that permits transfer to the device, the number of transfer command signals output by the main scanning direction processing unit, and the image developed by the image processing unit When the number of transfer command signals reaches the given variable set value, the image processing unit sends the in-field processing completion signal to the image processing section when the number of transfer command signals reaches the given variable set value. And a control means for giving the sub-scanning direction processing unit a variable set value that is set so as to be variable in size depending on the size of the electronic component.

[0008]

With the above arrangement, the control means gives a variable set value to the sub-scanning direction processing section according to the size of the electronic component. As a result, for a small size object, the number of times the main scanning direction processing unit outputs the transfer command signal from the start of processing until the sub scanning direction processing unit outputs the in-field processing completion signal, that is, the sub direction. The length of the field of view in the scanning direction is reduced.
As a result, a narrow field of view is set for a small size object, and the total reading time (approximately the transfer time of the shift register multiplied by the number of times the transfer command signal is output) is shortened, resulting in higher speed. Read processing can be realized.

[0009]

Embodiments of the present invention will now be described with reference to the drawings.

FIG. 1 is a plan view of an electronic component mounting apparatus in one embodiment of the present invention, FIG. 2 is a side view of a mounting head in one embodiment of the present invention, and FIG. 3 is an electronic component mounting in one embodiment of the present invention. FIG. 4 is a block diagram of the apparatus, and FIG. 4 is an explanatory view of the field of view of the electronic component mounting apparatus in one embodiment of the present invention. In the figure, the same components as those of FIG. 5 showing the conventional configuration are designated by the same reference numerals and the description thereof will be omitted.

In FIG. 1, 10 is an XY table as a positioning means for positioning a substrate 11 as an object, 12 is a base provided at a position distant from the XY table 10, and 13 is on the base 12 in the X direction. The supply table is slidably mounted, and a group of parts feeders 14 for supplying electronic components 15 of various types (that is, various sizes) are arranged in parallel on the supply table 13. 16 is a ball screw which is long in the X direction and is rotatably supported by the base 12.
Reference numeral 17 denotes a supply table moving motor that rotates the ball screw 16. Although not shown, the supply table 1
A ball nut that is screwed into a ball screw 16 is fixed to the lower surface of 3, and the supply table 13 can be moved in the X direction by driving the supply table moving motor 17.

Reference numeral 18 denotes a mounting head table that is long in the Y direction and is fixedly provided with respect to the base 12, and that is a mounting head table as a moving means. A mounting head 20 is slidably guided by the guide 19. Reference numeral 21 denotes a ball screw rotatably supported in the mounting head table 18, and a ball nut 22 fixed to the mounting head 20 is screwed into the ball screw 21. The ball screw 21 is mounted on the mounting head moving motor 23. The mounting head 20 is rotated in the Y direction (that is, the parts feeder 1 by the rotation force).
4 and the substrate 11). The mounting head moving motor 23 is driven by the drive circuit D23 shown in FIG. 3, and moves the mounting head 20 at a constant low speed above the recognition box 30 and at a high speed in other cases. The rotation state of the mounting head moving motor 23 is sensed by the encoder 24, and the current position of the mounting head 20 can be known by counting the pulse signal of the encoder 24 by the current position counter CT shown in FIG. It has become. Reference numeral 30 is a recognition box disposed between the parts feeder 14 and the substrate 11, 31 is a recognition box 30, and a one-dimensional CC for observing the electronic component 15 held by the mounting head 20 in the moving path upward.
The D cameras 32 are provided on both sides of the one-dimensional CCD camera 31, and are light sources for irradiating the electronic component 15 with light. 1
The configuration of the dimensional CCD camera 31 itself is the same as that shown in FIG.

Next, referring to FIG. 2, the mounting head 2
Details of 0 will be described in detail. Reference numeral 25 is an elevating frame supported so as to be able to move up and down, 26 is a vertical ball screw, 27 is a ball nut fixed to the elevating frame 25 by screwing with the ball screw 26, 28 is a Z motor for rotating the ball screw 26, and 29 is an elevating frame. A vertical θ-axis rotatably supported by 25, 33 is a head main body integrally provided on the θ-axis 29, which has a nozzle 34 for adsorbing the electronic component 15, and 35 is horizontal. This is a rotating θ motor.
Therefore, when the Z motor 28 is driven, the electronic component 15 held by the nozzle 34 can be lowered to bring the electronic component 15 closer to the recognition box 30, and the drive circuit D28 shown in FIG. When you drive
The posture can be corrected by rotating the electronic component 15 in the θ direction.

Next, a rough block of the recognition system will be described with reference to FIG. In FIG. 3, A is a clock C
The time elapsed after outputting the transfer command signal for permitting the transfer to the shift gate 4 with reference to the clock signal generated by L is compared with the constant time indicated by the constant setting value given from the control means C, The main scanning direction processing unit outputs the next transfer command signal to the shift gate 4 when the predetermined time has elapsed. That is, the main scanning direction processing section A controls the processing for one line (main scanning direction) of the one-dimensional CCD camera 31 so as not to mix the charges as described in the section of the conventional technique. Is.

Next, B is the number of transfer command signals output from the main scanning direction processing unit A and the sub scanning direction (orthogonal to the main scanning direction, the electronic component 15 is moved in the image developed by the image processing unit 48). (Parallel to the direction) and the variable set value provided from the control means C is compared so as to correspond to the length of the field of view, and when the field length in the sub-scanning direction reaches the given variable set value, the image The sub-scanning direction processing unit outputs a processing completion signal within the visual field to the processing unit 48. That is, the sub-scanning direction processing unit B controls, so to speak, the process of capturing a plurality of lines, and widens the field of view of the image developed in the image processing unit 48 according to a given variable set value. Perform the process of narrowing.

Reference numeral C is a control means for controlling the whole, which controls the drive circuits D23 and D28 in order to control the movement of the electronic component 15 as described above, and the main scanning direction control section A has a photosensitive element array. A fixed set value is given in consideration of the number of photosensitive elements of 2 and the transfer time from the shift register 3, and the electronic component 15 approaches the sub-scanning direction processing unit B above the recognition box 30 to move the mounting head. When the operation of the motor 23 is switched from the high speed movement to the constant low speed movement, a start signal is output and a variable set value according to the size of the electronic component 15 currently attracted to the nozzle 34 is given. When the image processing unit 48 receives the in-field processing completion signal, the image processing unit 48 processes the read image signal and outputs the processing result to the control means C. The processing content of the image processing unit 48 is electronic. It is possible to arbitrarily select whether to detect the presence or absence of the component 15 or to detect the amount of displacement. The in-field processing completion signal is also output to the control means C. When the in-field processing signal is input, the control means C commands the drive circuit D23 to switch the mounting head moving motor 23 from the constant low speed moving state to the high speed moving state. .

Next, the contents of the control means C will be described. Reference numeral 40 denotes the type of the electronic component 15 to be adsorbed to the nozzle 34, its size, and a field of view appropriately set according to the size (for the image S2 of a small size electronic component, as shown in FIG. The number of pixels (that is, the number of lines) in the sub-scanning direction of the narrow visual field V2 and the wide visual field V1 of the length Y1 for the image S1 of the large-sized electronic component.
A variable setting value given to the main scanning direction processing unit A, a storage unit including a memory for storing a constant setting value given to the main scanning direction processing unit A, and the like.
Reference numeral 1 is a controller that performs input / output by referring to data in the storage unit 40.

Next, the contents of the main scanning direction processing section A will be described. 42 is a shift trigger counter presetter in which a constant set value is set by the controller 41, 44 is reset by a transfer command signal output from the comparator 43, and the clock signal is up-counted to the comparator 43 to display the main scanning direction current value. A shift trigger counter for output, 43 is a shift trigger counter presetter 42
Is a comparator for opening the shift gate 4 by comparing the current value in the main scanning direction indicated by the shift trigger counter 44 with the constant reference value. The transfer command signal is also output to the screen trigger counter 47 of the sub-scanning direction processing unit B at the same time.

Next, the contents of the sub-scanning direction processing section B will be described. Reference numeral 45 is a screen trigger counter presetter in which a variable set value is set from the controller 41, and 47 is reset by the in-field processing completion signal output from the comparator 46, and the transfer command signal is up-counted to display the sub scanning direction current value. The output screen trigger counter, 46 compares whether or not the sub scanning direction present value indicated by the screen trigger counter 47 has reached the variable reference value indicated by the screen trigger counter presetter 45, and when it reaches, the controller 41, the image processing unit 48 and This is a comparator that outputs an in-field processing completion signal to the image trigger counter 47 and resets the screen trigger counter 47.

The electronic component mounting apparatus of this embodiment has the above-mentioned structure, and its operation will be described below. In this operation, it is assumed that the small-sized electronic component shown in the image S2 of FIG. 4 is first mounted, and then the large-sized electronic component shown in the image S1 of FIG. 4 is mounted.

When mounting a small-sized electronic component, the supply table moving motor 17 is driven and the part feeder 14 for supplying a small-sized electronic component moves to the movement path of the mounting head 20. Also the controller 4
1 drives the mounting head moving motor 23 to move the mounting head 20 to the parts feeder 14 side at high speed, drives the Z motor 28, and lowers the nozzle 34 to pick up an electronic component. Further, the controller 41 reads the information about the width of the field of view (that is, the number of pixels corresponding to the length Y2 in FIG. 4) set for the small-sized electronic component, and sets it in the screen trigger counter presetter 45 as a variable set value. set.

Next, the controller 41 is the parts feeder 1
4 from the reading start position in front of the photosensitive element array 2, that is, until the nozzle 34 approaches the photosensitive element array 2 up to a distance half the length of the visual field in the sub-scanning direction.
Is moved at a high speed, and when the reading position is reached, a fixed set value corresponding to the number of photosensitive elements (pixel number W in FIG. 4) of the photosensitive element array 2 is set in the shift trigger counter presetter 42, and A start signal is output to the trigger counter 47. At this time, the values of the shift trigger counter 44 and the screen trigger counter 47 are initialized to zero.

Then, the controller 41 switches the mounting head moving motor 23 to a constant low speed state so that the electronic parts pass over the one-dimensional CCD camera 31 at a low speed. At this time, the following operation is performed. That is, when the light near the electronic component illuminated by the light source 32 is incident on each photosensitive element of the photosensitive element array 2, the clock signal is input to the shift trigger counter 44 at a high frequency and is output by the shift trigger counter 44. The current value in the scanning direction is counted up and rises. At this time, the comparator 43 compares the constant reference value of the shift trigger counter presetter 42 and the current value in the main scanning direction of the shift trigger counter 44, and only a certain time required for the transfer of the shift register 3 has elapsed since the start signal was output. , When the constant reference value and the current value in the main scanning direction match, a transfer command signal is output to the shift gate 4,
The charges accumulated in each photosensitive element of the photosensitive element array 2 are collectively transferred to the shift register 3 within this fixed time.
The transfer command signal advances the current value in the sub-scanning direction of the screen trigger counter 47 by one line. At this stage, the current value in the sub-scanning direction is compared with the variable reference value indicated by the screen trigger counter presetter 45 in the comparison by the comparator 46. Since it is below the threshold, the in-field processing completion signal is not output. Then, the image signals are output from the output unit 5 to the image processing unit 48 one by one in synchronization with the clock signal. At this time, charges corresponding to the next line on the image are simultaneously accumulated in each photosensitive element of the photosensitive element array 2, and the shift trigger counter 44 continues to count up after being reset by the previous transfer command signal. . Then, when the above-mentioned certain time has elapsed from the previous transfer command signal, the next transfer command signal is output, and the above processing is repeated.

When the above-mentioned processing is repeated, the current value in the sub-scanning direction indicated by the screen trigger counter 47 is increased by the line for which the processing has been completed, and finally the reading for the line indicated by the length Y2 in FIG. 4 is completed. At this time, the current value in the sub-scanning direction matches the variable reference value, the in-field processing completion signal is output, and the screen trigger counter 47 is reset.
Then, the controller 41 moves the mounting head moving motor 2
3 is switched to high speed movement and moved to the substrate 11 side. Here, the image processing unit 48 outputs the processing result such as the positional deviation amount to the controller 41, and the controller 41 causes the θ motor 3 to operate.
The position correction is performed by 5, etc., and the Z motor 28 is driven to lower the nozzle 34 to mount the electronic component on the substrate 11.

Next, when a large-sized electronic component is mounted, the variable set value given to the screen trigger counter presetter 45 is large (for example, in the electronic component of the image S1 in FIG. 4, the line corresponding to the length Y1). Therefore, the time from the output of the start signal to the output of the in-field processing completion signal is increased by (Y1 / Y2) times. Others are the same as the above, and thus the description is omitted.

Although the present invention has been described above, various design changes may be made. For example, the shift trigger counter 44 counts up the clock signal, and the comparator 43 compares the count value (main scanning direction current value) with a constant reference value set in the shift trigger counter presetter 42 to obtain a transfer command signal. Is output every time a fixed time elapses, the pulse signal output from the encoder 24 may be counted by the shift trigger counter 44. In this case, a transfer command signal is output every time the mounting head 20 moves a distance corresponding to the constant reference value set in the shift trigger counter presetter 42. However, the photosensitive element is generated due to unevenness of the moving speed of the mounting head 20. The exposure time of the array 2 may vary and the image quality may deteriorate. Therefore, it is preferable that the transfer command signal is output every time a predetermined time elapses as in the present embodiment.

Further, in this embodiment, a variable setting value for determining the length of the visual field in the sub-scanning direction is set according to the size of the electronic component. Alternatively, the variable set value may be set for each class.

[0028]

According to the electronic component mounting apparatus of the present invention, a photosensitive element array in which a large number of photosensitive elements are arranged in a line in the main scanning direction and charges accumulated in each photosensitive element of the photosensitive element array are transferred. Shift register, a shift gate that permits or prohibits the transfer of charges from the photosensitive element array to the shift register, and the charges transferred to the shift register to the image processing unit in the subsequent stage as sequential image signals at a timing of a clock signal or an integral multiple thereof. A one-dimensional CCD having an output unit for outputting, and a photosensitive element array having a main scanning direction set in a direction intersecting the movement direction of the mounting head in the middle of the movement path.
The main scanning direction processing unit that outputs a transfer command signal that permits transfer to the camera and the shift gate, the number of transfer command signals that the main scanning direction processing unit outputs, and the sub scanning direction in the image developed by the image processing unit. Sub-scan that compares the given variable set value corresponding to the length of the field of view and outputs the in-field processing completion signal to the image processing unit when the number of transfer command signals reaches the given variable set value Since the direction processing unit and the sub-scanning direction processing unit are provided with a control unit that gives a variable set value that is set to be large or small according to the size of the electronic component,
As for the reading of small-sized electronic components, the variable setting value is made small so that the visual field in the sub-scanning direction can be narrowed, and the reading process can be speeded up accordingly.

[Brief description of drawings]

FIG. 1 is a plan view of an electronic component mounting apparatus according to an embodiment of the present invention.

FIG. 2 is a side view of the mounting head according to the embodiment of the present invention.

FIG. 3 is a block diagram of an electronic component mounting apparatus according to an embodiment of the present invention.

FIG. 4 is an explanatory view of a field of view of an electronic component mounting apparatus according to an embodiment of the present invention.

FIG. 5 is an operation explanatory diagram of a conventional one-dimensional CCD camera.

FIG. 6 is an operation explanatory view of a conventional one-dimensional CCD camera.

FIG. 7 is an explanatory diagram showing a relationship between an electronic component and a visual field set in a conventional electronic component mounting apparatus.

[Explanation of symbols]

 1 1-dimensional CCD camera 2 photosensitive element array 3 shift register 4 shift gate 5 output section 10 XY table 11 substrate 14 parts feeder 15 electronic parts 42 shift trigger counter presetter 43 comparator 44 shift trigger counter 45 screen trigger counter presetter 46 comparator 47 Screen trigger counter 48 Image processing unit A Main scanning direction processing unit B Sub scanning direction processing unit C Control means V1 Field of view V2 Field of view Y1 Length Y2 Length

Claims (3)

[Claims] 1. A mounting head for receiving an electronic component and mounting it on an object positioned by a positioning means, a clock for generating a clock signal, and a large number of photosensitive elements arranged in a line in the main scanning direction. A photosensitive element array, a shift register to which the charge accumulated in each photosensitive element of the photosensitive element array is transferred, a shift gate that permits or prohibits the transfer of the charge from the photosensitive element array to the shift register, and a shift register to the shift register. And an output unit that sequentially outputs the transferred charges as an image signal to an image processing unit in a subsequent stage according to the clock signal, and the photosensitive element array intersects the movement direction of the mounting head in the middle of the movement path of the mounting head. A one-dimensional CCD camera in which the main scanning direction is set in the direction, and a main scanning direction that outputs a transfer command signal that permits transfer to the shift gate A processing unit, the number of transfer command signals output by the main scanning direction processing unit, and a variable set value provided corresponding to the length of the visual field in the sub scanning direction in the image developed by the image processing unit. In comparison, when the number of times of the transfer command signal reaches a given variable set value, a sub-scanning direction processing unit that outputs an in-field processing completion signal to the image processing unit, and an electronic component to the sub-scanning direction processing unit An electronic component mounting apparatus, comprising: a control unit that gives a variable set value that is set so as to change in size according to the size of the electronic component mounting apparatus. 2. A main scanning direction processing section is reset by a transfer command signal, and a shift trigger counter which counts up a clock signal and outputs a main scanning direction current value, and a constant provided by the control means. A shift trigger counter presetter that outputs a constant reference value based on a set value, and a comparator that outputs a transfer command signal when the main scanning direction current value and the constant reference value match each other. Item 1. The electronic component mounting apparatus according to item 1. 3. A sub-scanning direction processing section is reset by a field-of-view processing completion signal, and a screen trigger counter for counting up a transfer command signal to output a sub-scanning direction current value, and the control means. A screen trigger counter presetter that outputs a variable reference value based on the obtained variable set value, and a comparator that outputs an in-field processing completion signal when the sub scanning direction current value and the variable reference value match. The electronic component mounting apparatus according to claim 1, wherein: