JPH07174518A - Apparatus for detecting position of part - Google Patents

Abstract

PURPOSE:To detect accurately the position of a part, wherein many pins are arranged, even if the size and the shape of the part, the width of the pin and the interval between the pins are different. CONSTITUTION:The transmitted light or the reflected light at the pin part of a semiconductor chip 10 when light from a lamp 12 is cast on the semiconductor chip 10 wherein many pins are arranged, is received by a CCD camera 14. The position of the semiconductor chip 10 is detected based on the received signal. In this part-position detecting apparatus, an illuminance switching device 24, which adjusts the illuminance of the illuminated light in correspondence with the size and the shape of the semiconductor ship, the width of the pin and the interval of the pins, is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a component position detecting device, and more particularly to a component position detecting device suitable for application to a chip mounter used for mounting semiconductor chips.

[0002]

2. Description of the Related Art Generally, in a chip mounter for mounting a semiconductor chip on a substrate or the like, it is necessary to mount the chip accurately at a predetermined position. Therefore, before mounting the chip mounter (from the center and the reference direction). Tilt) must be detected.

FIG. 6 shows a chip mounter which detects the position of a QFP (Quad Flat Package) type semiconductor chip (component) 10 in which pins are arranged around four directions by a transmission type component position detecting device. FIG. 3 is a front view of an essential part showing a state in which a light is emitted from above the chip 10 by a lamp 12 provided with a large number of light emitting diodes LD, and a CCD arranged below the chip 10.
The light transmitted through the pins is received by the camera 14, and the position of the chip 10 is detected based on the received light signal at that time. Reference numeral 15 in the figure is a glass plate for supporting the chip 10.

Further, as a device for detecting the position of the chip 10, there is also a reflection type device whose essential structure is shown in FIG. In this device, as shown in FIG. 7 (A), below the chip 10 whose back surface is held by the vacuum nozzle 16, FIG.
A lamp 12 having a hole at the center thereof is arranged as shown in the plan view, and the reflected light from the chip 10 is captured by a camera 14 from below the hole of the lamp 12. In addition, the lamp 12 shown in FIG.
Corresponds to the -A cross section.

Since the principle of detection by the above-mentioned transmission type and reflection type detection devices is basically the same, a method for detecting the position of the chip 10 will be described for the transmission type detection device.

FIG. 8 shows the relationship between the field of view 18 and the chip 10 when the camera 10 captures the chip 10 having a large size. The light received through the position of line A in the drawing is received. The signal is shown conceptually in FIG. In FIG. 9, the broken line circle B of FIG. 8 is enlarged and shown in the upper part, and the maximum value (MA of the light receiving level of the camera 14 is shown in the lower part).
X) and the minimum value (MIN), and the actually detected wave-shaped light-receiving signal, and the line showing the maximum value of the light-receiving level is shown by a bold line indicating the width and the pin interval corresponding to the pin P. There is.

Conventionally, when the pin position is detected from the received light signal of FIG. 9, a constant threshold value Th) shown by a broken line in the figure is set, and the position of the pin is detected from the intensity of the received light signal equal to or higher than the threshold value Th. ing.

[0008]

However, in the above-mentioned conventional component position detecting device, the illuminance by the light source (lamp) is set to be constant, and the threshold value Th is set to be constant.
There were the following problems.

That is, as shown in the relationship between the field of view 18 and the chip 10 in FIG. 10, in the case of a small chip 10 having substantially the same pin width and pin spacing as in the case of FIG.
As shown in 1, the minimum value of the received light signal rises, and the level difference between the maximum value and the minimum value of the signal becomes small. this is,
It is considered that this is because the chip 10 is small and the amount of light incident on the camera 14 is generally increased.

Conventionally, since the threshold value Th is constant, if it is set near the intermediate value of the amplitude of the received light signal as shown in FIG. 9 according to the large chip 10 shown in FIG. If the small chip 10 is detected below, the margin of the level difference of the received light signal becomes small as shown in FIG. 11, and the threshold Th is located below the amplitude of the received light signal, so that the detection accuracy is deteriorated. become.

On the contrary, when the chip size is the same as that in FIG. 8 and the pin width and the pin interval are small, the light receiving signal level is lowered as a whole as shown in FIG.
h is located above the amplitude. As can be seen from the relationship between the spatial frequency of the received light signal corresponding to the pin pitch (pin width + pin interval) and the input level of the signal actually input to the camera 14, the pin pitch is 0.65 mm. (Width 0.32mm, spacing 0.33mm) and pin pitch 0.50mm (width 0.20mm, spacing 0.30mm), the input level is lower when the pin pitch is 0.50mm. It is considered that this is because the amount of transmitted light decreases.

Therefore, when the chip 10 is detected by the transmission type detection device, when the illuminance and the threshold value Th are fixed and fixed as in the conventional case, the threshold value Th is the amplitude of the received light signal. On the other hand, there is a case where the chip is out of the appropriate range, so that there is a problem that the position cannot be accurately detected in the case of chips having different dimensions, pin widths, and pin intervals.

On the other hand, in the case of the reflection type detector, although the change in the received light level due to the size of the chip is small, FIG.
When the pin width and the pin interval are large, the light receiving level changes depending on the pin width and the pin interval, as shown in FIG.

The present invention has been made to solve the above-mentioned conventional problems, and chips such as semiconductor chips in which a large number of pins are arranged have different dimensional shapes, pin widths, and pin intervals. Even in such a case, it is an object to provide a component position detection device that can accurately detect the position of the chip.

[0015]

SUMMARY OF THE INVENTION According to the present invention, when light is emitted from a light source to a chip having a large number of pins, transmitted light at the pin portion of the chip is received by a light receiving means, and a light receiving signal thereof is received. In the component position detecting device for detecting the position of the component based on the, when the size and shape of the chip is smaller than the reference, by providing an illuminance adjusting means for reducing the illuminance of the irradiation light, it is possible to solve the above problems. is there.

According to the present invention, when light is emitted from a light source to a chip on which a large number of pins are arranged, transmitted light or reflected light at the pin portion of the chip is received by a light receiving means, and the light receiving signal is received. In a component position detection device that detects the position of a component based on the above, if the pin spacing when receiving transmitted light or the pin width when receiving reflected light is smaller than the reference, illuminance adjustment that raises the illuminance of irradiation light By providing the means, the above problems are similarly solved.

[0017]

In the present invention, when the size of the chip (component) is not the standard, the illuminance adjusting means for lowering the illuminance of the irradiation light is provided, so that the component having a large number of pins is irradiated with light. Then, when the transmitted light at that time is received by the light receiving means and the position of the component is detected based on the received light signal, a light receiving signal that causes a detection error due to the size and shape of the chip being below the reference is detected. Since it is possible to adjust to a level suitable for the above, it becomes possible to improve the position detection accuracy of the chip.

Further, in the present invention, the illuminance adjusting means for increasing the illuminance of the irradiation light is provided when the pin interval when receiving the transmitted light or the pin width when receiving the reflected light is smaller than the reference. Since the pin spacing is less than the reference when detecting transmitted light and the pin width is less than when detecting reflected light, a detection signal that causes a detection error can be set to an appropriate light receiving level. Similarly, highly accurate position detection becomes possible.

In the present invention, the standard of the dimension and shape of the chip and the standard of the pin width or the pin interval are detected in advance for each of various chips and are determined based on the actually measured data obtained.

[0020]

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

FIG. 1 is a block diagram showing a schematic structure of a chip mounter to which the position detecting device of the first embodiment according to the present invention is applied.

The detection apparatus of this embodiment is the same as the transmission type shown in FIG. 6, and the detection apparatus is the CCD camera 14
And a host computer 22 connected to the control device 20 so that data can be transmitted and received.
And an illuminance switching device 24 for adjusting the illuminance by the lamp 12 based on the information input from the control device 20. The host computer 22 stores a predetermined threshold value, a reference chip size, a pin width, a pin interval for the threshold value, and information such as illuminance to be set for chips below the reference value.

The control device 20 has a built-in C
A PU (Central Processing Unit) calculates the position of the chip 10 based on the light reception signal input from the camera 14, and also conveys and mounts the chip 10 at a predetermined position based on the detected position information. , Host computer 22
It is possible to control the operation of outputting a switching signal to the illuminance switching device 24 and the like so that the illuminance of the irradiation light from the lamp 12 is appropriately set based on the information according to the type of the chip 10 input from the. ing.

FIG. 2 is a circuit diagram showing the relationship between the circuit configuration built in the illuminance switching device 24 and the n light emitting diodes LD1 to LDn mounted on the lamp 12. As shown in FIG.

Here, three types of resistors R, 2R, and 4R can be connected in parallel to the transistor T by a relay, and the electromagnetic coil RY for opening and closing the relay is connected.
1, RY2, RY3 are activated based on the input signal from the control device 20, and the resistors are set to a desired combination, whereby the voltage applied to the light emitting diodes LD1 to LDn is adjusted to switch to a desired illuminance. It is like this.

In the present embodiment, when the position of the chip 10 is detected, the illuminance suitable for the chip 10 is determined based on the information such as the dimensions and shape of the chip and the pin width and the pin interval which are input from the host computer 22. Since it can be adjusted, its position (center, inclination, etc.) can be accurately detected.

That is, the case where the threshold value Th is set in accordance with the almost intermediate value of the amplitude of the received light signal shown in FIG. 9 will be described as a reference. In the case of the small chip shown in FIG. By reducing the illuminance by 12,
As shown in FIG. 3, since the low level value can be further reduced as compared with the light receiving level shown in FIG. 11, the lower limit of the signal amplitude can be adjusted to a level sufficiently lower than the threshold Th, so that the detection accuracy can be improved. It is possible to raise.

In the case of the chips of the same size with small pin width and pin spacing shown in FIG. 12, conversely, by raising the illuminance as compared with the case of FIG. 9, the light receiving level is entirely changed as shown in FIG. Since it can be increased, the detection accuracy can be similarly improved.

As described above in detail, according to this embodiment, the illuminance can be appropriately switched according to the size and shape of the semiconductor chip 10, the pin width, and the pin interval.
It becomes possible to accurately detect the position of
It is possible to improve the mounting accuracy of 0.

Next, a second embodiment according to the present invention will be described.

The present embodiment is substantially the same as the first embodiment except that the reflection type detection device shown in FIG. 7 is applied to the chip mounter shown in FIG. 1 instead of the transmission type detection device. Are the same.

According to this embodiment, the threshold Th is set to the value shown in FIG.
If it is set to the value shown in FIG. 5, it is possible to raise the high level value of the received light signal shown in FIG. 15 by appropriately raising the illuminance, as shown in FIG.
The detection accuracy can be improved as in the case of the first embodiment.

The present invention has been specifically described above, but the present invention is not limited to the above-mentioned embodiments, and various modifications can be made without departing from the scope of the invention.

For example, the illuminance adjusting means is not limited to the one having the circuit configuration shown in FIG. 2, but is not limited as long as it can adjust the voltage applied to the light emitting diode, and the light emitting body is not limited. It is not limited to light emitting diodes.

In the above-mentioned embodiment, the case where the component is a QFP type chip has been shown, but a so-called SOP (Small Outline Package) type chip in which pins are arranged in two directions is also used. Any component may be used as long as the pins are arranged.

Further, in the above-mentioned embodiment, the case where the illuminance set in advance for each type of semiconductor chip is shown, but the present invention is not limited to this, and the fixed threshold value is approximately the middle of the amplitude of the light receiving signal. The illuminance may be automatically controlled so as to match the value.

[0037]

As described above, according to the present invention,
It is possible to accurately detect the position of a component such as a semiconductor chip in which a large number of pins are arranged, even if the size, shape, pin width, and pin interval are different.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of a chip mounter to which a component position detecting device according to a first embodiment of the present invention is applied.

FIG. 2 is a circuit diagram showing a configuration of a circuit incorporated in the illuminance switching device.

FIG. 3 is a diagram showing a light reception signal detected by a transmission type detection device with a small chip at a reduced illuminance.

FIG. 4 is a diagram showing a light reception signal obtained by detecting a large chip having a small pin pitch by increasing the illuminance by a transmission type detection device.

FIG. 5 is a diagram showing a light reception signal detected by increasing the illuminance of a chip with a narrow pin width by a reflection type detection device.

FIG. 6 is a schematic front view showing the configuration of the main parts of a transmission type component position detection device.

7A and 7B are a front view and a plan view of a lamp, showing a main configuration of a reflective component position detecting device.

FIG. 8 is an explanatory diagram showing the relationship between the field of view of the camera and the large chip.

FIG. 9 is a diagram showing a light reception signal obtained by detecting a large chip having a small pin pitch by a conventional method.

FIG. 10 is an explanatory diagram showing the relationship between the field of view of the camera and the small chip.

FIG. 11 is a diagram showing a light reception signal obtained by detecting a small component having a small pin pitch by a conventional method.

FIG. 12 is a diagram showing a light reception signal obtained by detecting a large chip having a smaller pin pitch by a conventional method.

FIG. 13 is a diagram showing the relationship between the spatial frequency of the received light signal and the camera input signal level.

FIG. 14 is a diagram showing a light reception signal obtained by detecting a large chip having a large pin pitch with a conventional reflection type device.

FIG. 15 is a diagram showing a light receiving signal obtained by detecting a large chip having a small pin pitch with a conventional reflection type device.

[Explanation of symbols]

 10 ... Semiconductor chip 12 ... Lamp 14 ... CCD camera 16 ... Vacuum nozzle 18 ... Field of view 20 ... Control device 22 ... Host computer 24 ... Illuminance switching device

Claims (2)

[Claims] 1. A light receiving means receives the light transmitted through a pin portion of the chip when the light source irradiates the chip on which a large number of pins are arranged, and detects the position of the component based on the received light signal. In the component position detecting device, the component position detecting device is provided with an illuminance adjusting means for reducing the illuminance of the irradiation light when the size and shape of the chip are smaller than the reference. 2. A light receiving unit receives transmitted light or reflected light at a pin portion of the chip when light is emitted from a light source to a chip provided with a large number of pins, and a component of the component is detected based on the received light signal. In the component position detection device that detects the position, if the pin spacing when receiving transmitted light or the pin width when receiving reflected light is smaller than the reference, illuminance adjusting means for raising the illuminance of the irradiation light is provided. A component position detection device characterized by the above.