JPH0643102A - Observing apparatus for chip - Google Patents

Abstract

PURPOSE:To obtain an observing apparatus of a chip which enables selection of observing a lead of the chip as a dark one in a bright background and observing it as a bright one in a dark background. CONSTITUTION:A light source 8 emitting a plurality of kinds of lights different in spectral characteristics is provided and a filter 3 having different transmittances for the discrete lights and a light-reflecting plate 2 are provided. When the light of the light source 8 is changed over, the brightness of a lead L and the light-reflecting plate 2 at the back of the lead L is changed over and, therefore, observation of the lead L as a dark one in a bright background and observation of the lead L as a bright one in a dark background can be selected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chip observing apparatus, and more particularly, to observing a chip electrode in a bright background darkly and in a dark background brightly observing the chip. Regarding the device.

[0002]

2. Description of the Related Art A chip mounter for automatically mounting chip-type electronic components (hereinafter referred to as "chips") such as ICs, LSIs, resistance chips, and capacitor chips on a board is
A chip is vacuum-sucked to the lower end of the nozzle of the transfer head, and the chip is transferred above the substrate so that the electrode of the chip is aligned with the electrode of the substrate and mounted.

In this case, since the electrodes of the chip must be mounted so that they are correctly aligned with the electrodes of the substrate, the chip adsorbed by the nozzle is observed by a camera before the transfer head mounts the chip on the substrate. The positional deviation of the chip, especially the positional deviation of the electrode thereof, is optically detected, the detected positional deviation is corrected, and then the chip is mounted on the substrate.

As an apparatus for observing such a chip, for example, as disclosed in Japanese Patent Laid-Open No. 2-99000, a light diffusing plate such as a white acrylic resin plate is provided below the transfer head. A means is known in which light is emitted from below toward the light diffusion plate and the reflected light is received by the camera below. According to this means, the electrodes of the chip P are placed in a bright background as shown in FIG. L can be observed darkly.

On the contrary, by providing a dark-colored light absorbing plate under the transfer head, irradiating light from below toward the chip vacuum-adsorbed by the nozzle, and observing with the camera below. As shown in FIG. 4, a means for observing the electrode L of the chip P brightly in a dark background is known. In any case, the chip observing device clearly recognizes the electrodes by observing the electrodes of the chip and the background thereof with clear contrast of light and dark.

[0006]

The transfer head transfers and mounts various types of chips on a substrate. Depending on the types of chips, the transfer heads are mounted in two bright and dark patterns shown in FIGS. It is desirable to observe. However, conventionally, there has been no means for observing the two light / dark modes with the same observation device, and therefore, the means for observing the electrode L in a dark background as shown in FIG. 3 or the dark background as shown in FIG. The bright observation method was adopted as an alternative.

Therefore, according to the present invention, according to the type of chip,
It is possible to observe the electrode darkly in a bright background and brightly observe it in a dark background, and to provide an observation device of a chip that can easily select these two observation modes. To aim.

[0008]

To this end, the present invention is directed to a light reflecting plate disposed behind a chip vacuum-adsorbed on the lower end of a nozzle, and a light reflecting plate below the light reflecting plate and superposed on the light reflecting plate. Arranged differently and having different transmittances for plural kinds of light, a light source for irradiating the plural kinds of light toward the filter and the light reflection plate, a switching means for switching the kind of the light, the filter and the light reflection. A camera is provided on which light transmitted / reflected is incident on the plate.

[0009]

According to the above structure, it is easy to observe the electrode of the chip darkly in the light background and brightly in the dark background by switching the kind of light according to the kind of the chip. You can observe the chip while selecting.

[0010]

【Example】

(Embodiment 1) Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a side view of a chip observation apparatus.
A light reflecting plate 2 such as an aluminum plate is arranged under the transfer head 1, and a blue transparent filter 3 is provided under the light reflecting plate 2 so as to overlap with each other. At the lower end of the nozzle 4 protruding downward from the transfer head 1, a chip P having a lead L as an electrode such as QFP or SOP is vacuum-sucked. Light reflector 2
The filter 3 is arranged behind the chip P which is vacuum-adsorbed on the lower end 1 of the nozzle 4. In this embodiment, the light reflection plate 2 and the filter 3 are laminated, but a gap may be provided between them. The transfer head 1 vacuum-adsorbs a chip P provided in a parts feeder (not shown) onto a nozzle 4 and picks it up, and transfers and mounts it on a substrate (not shown). The displacement of the lead L of the chip P attracted to the nozzle 4 is detected by the observation device.

Reference numeral 5 denotes a case provided below the moving path of the transfer head 1, and a half mirror 6 is provided inside the case.
The camera 7 is installed with an inclination, and a camera 7 for receiving the light reflected by the half mirror 6 is provided on the side thereof. Further, on the back surface of the half mirror 6, a light source 8 that irradiates the transfer head 1 with light is provided. In this embodiment, the light source 8 is an LED and selectively emits two types of light, green light and red light, which have different spectral characteristics. Reference numeral 9 is a control unit as switching means for switching between green light and red light. Of course, the green light source and the red light source may be provided separately. Reference numeral 10 denotes an auxiliary plate, which is made of the same material as that of the light reflection plate 2 and the filter 3 described above.
a is overlapped (see also FIG. 7). Reference numeral 13 is a slit for fitting into the nozzle 4. This auxiliary plate 1
0 is held by the rod 12 of the cylinder 11, and when the rod 12 protrudes and retracts, it advances to the position just below the transfer head 1 and retreats laterally. The role of the auxiliary plate 10 will be described later.

FIG. 2 shows the spectral characteristics of green light G and red light R,
The characteristic of the light transmittance BF of the filter 3 is shown. As shown in the figure, the peak wavelength of the green light G is around 565 nm and is concentrated around this wavelength, while the peak wavelength of the red light R is around 660 nm. Further, the transmittance of the filter 3 is high near 610 nm (80%) and remarkably low above it (10%). Therefore, the filter 3 hardly transmits the red light R, but most of the green light G is transmitted.

FIG. 3 shows an image obtained by observing the chip P by turning off the red light R and turning on the green light G. In this image, the chip P is observed dark in the light background.
FIG. 5 shows the reason. FIG. 5A shows the brightness of the reflecting surface (aluminum mirror surface) of the light reflecting plate 2. The half mirror 6 has a transmittance of 0.5, the filter 3 has a transmittance of 0.8 (see FIG. 2), and the reflector (aluminum mirror) 2 has a reflectance of 0.8. Therefore, the green light G emitted from the light source 8 is the half mirror 6 → the filter 3 → the light reflection plate 2 → the filter 3 → the half mirror 6
Is transmitted and reflected to enter the camera 7, the effective rate of the green light G is the product of the respective transmittances and reflectances, and is as follows.

Product (effective rate) = 0.5 × 0.8 × 0.8 ×
0.8 × 0.5 = 0.128 Further, the green light G emitted from the light source 8 to the lead L (reflectance 0.1) passes through the half mirror 6 → the lead L → the half mirror 6 and reaches the camera 7. Since it is incident, the effective rate is as follows (see also FIG. 5B).

Product (effective rate) = 0.5 × 0.1 × 0.5 = 0.025 That is, the effective rate 0.128 of the aluminum mirror surface (light reflecting plate 2) which is the back plate of the chip P is Since the effective rate of the lead L is relatively larger than 0.025, the lead L of the chip P is observed dark in a bright background as shown in FIG. The molded body M of the chip P
Is black and absorbs light, so that it is observed as dark as the lead L.

When the green light G is turned off and the red light R is turned on, the chip P is brightly observed in a dark background as shown in FIG. In this case, the transmittance of the red light R of the filter 3 is 0.1 (see FIG. 2), and the effective rate of the reflecting surface (aluminum mirror surface) of the light reflecting plate 2 is 0.002.
The effective rate of the lead L is 0.025, exactly as in the case of FIG. Therefore, the effective rate of the lead L is 0.0
Since 25 is relatively much larger than the effective rate 0.002 of the aluminum mirror surface (light reflecting plate 2) which is the back plate thereof, the lead L of the chip P as shown in FIG.
Is brightly observed on a dark background.

By the way, in the case of the large chip P, the leads L are laterally projected from the light reflection plate 2 and the filter 3. In this case, the rod 12 of the cylinder 11 is projected to move the auxiliary plate 10 forward just above the chip P, and the upper part of the chip P is covered with this auxiliary plate 10. Since this auxiliary plate 10 is also formed by stacking the reflection plate 2a and the filter 3a made of the same material as the light reflection plate 2 and the filter 3,
The same effective rate as that shown in FIGS. 5 and 6 is obtained, and the chip P is observed as shown in FIGS. 3 and 4.

(Embodiment 2) FIG. 8 is a side view of a chip observation apparatus according to another embodiment. The light reflection plate 2 and the filter 3 are shaped so as to be able to reflect light emitted from obliquely downward, that is, V-shaped or conical. 20
Is a lamp case, on the upper surface of which a first light source 21
And a second light source 22. The first light source 21 emits green light G (peak wavelength 565 nm), and the second light source emits red light R (peak wavelength 660 nm). When the light reflection plate 2 and the filter 3 are V-shaped, the light source 2
Line-shaped light sources 1 and 22 are used, and when the reflection plate 2 and the filter 3 are conical, ring-shaped light sources are used.

The lamp case 20 is supported by the lens barrel 23, and the camera 7 is arranged below the lens barrel 23.
The irradiation of the light from the first light source 21 and the light from the second light source 22 is switched by the control unit 9.

The first light source 21 is turned on and the second light source 22 is turned on.
When is turned off, the green light G emitted from the first light source 21 passes through the filter 3 → reflector 2 → filter and is incident on the camera. Therefore, the effective rate is as follows.

Product (Effective Rate) = 0.8 × 0.8 × 0.8 = 0.512 The reflectance (effective rate) of the lead L is 0.1 as described above.
Is. Therefore, in this case, the lead L is darkly observed in the light background as shown in FIG.

When the first light source 21 is turned off and the second light source 22 is turned on, the red light R emitted from the second light source 22 passes through the filter 3 → reflector 2 → filter 3 Since it is incident on the camera 7, its effective rate is as follows.

Product (Effective Rate) = 0.1 × 0.8 × 0.1 = 0.008 Since the reflectance (effective rate) of the lead L is 0.1,
In this case, the lead L is brightly observed in the dark background as shown in FIG.

(Embodiment 3) The reflector 2 and the filter 3 shown in FIG. 9 are the same as those in Embodiment 2. Further, in this example, the first light source 24 that emits the green light G is the transfer head 1
The second light which is provided on the side of and emits red light R
The light source 25 is provided below the transfer head 1.

The operation of this is exactly the same as that of the second embodiment, and when the first light source 24 is turned on, the lead L is observed darkly in the bright background as shown in FIG. When the light source 25 is turned on, it is brightly observed in a dark background as shown in FIG. As described above, various optical systems can be considered.

The present invention is not limited to the above-mentioned embodiments. For example, the light source may be something other than green light or red light, and the point is to use a light source for irradiating a plurality of kinds of light having different spectral characteristics. By switching the type of light emitted to the transfer head 1 side, the chip can be observed with the two contrasts of light and dark shown in FIGS. Further, in the above-mentioned embodiment, a leaded chip such as QFP has been described as an example, but it goes without saying that the present invention can be applied to an electrode observing means such as a capacitor chip or a resistor chip.

[0028]

According to the present invention, the chip is observed dark in a bright background by a simple operation of switching the type of light irradiated to the transfer head side according to the type of chip adsorbed by the nozzle. And observing the chip brightly in a dark background can be easily selected, and the entire structure can be made compact.

[Brief description of drawings]

FIG. 1 is a side view of a chip observation apparatus according to an embodiment of the present invention.

FIG. 2 is a light transmittance and spectral characteristic diagram of a filter according to an embodiment of the present invention.

FIG. 3 is an image view of a chip according to an embodiment of the present invention.

FIG. 4 is an image view of a chip according to an embodiment of the present invention.

FIG. 5A is a calculation diagram of a light effective rate according to an embodiment of the present invention. FIG. 5B is a calculation diagram of a light effective rate according to an embodiment of the present invention.

FIG. 6 is a calculation diagram of a light effective rate according to an embodiment of the present invention.

FIG. 7 is a perspective view of a transfer head in an advanced state of an auxiliary plate according to an embodiment of the present invention.

FIG. 8 is a side view of a chip observation apparatus according to another embodiment of the present invention.

FIG. 9 is a side view of a chip observation apparatus according to another embodiment of the present invention.

[Explanation of symbols]

 1 Transfer Head 2 Light Reflecting Plate 3 Filter 4 Nozzle 7 Camera 8, 21, 22, 24, 25 Light Source 9 Switching Means

Claims (1)

[Claims] 1. A light reflecting plate disposed behind a chip vacuum-adsorbed at a lower end portion of a nozzle, and a light reflecting plate disposed below the light reflecting plate so as to be overlapped with the light reflecting plate. Different filters, a light source that irradiates a plurality of types of light toward the filter and the light reflection plate, a switching unit that switches the type of this light, and the light that is transmitted / reflected into the filter and the light reflection plate enters. And a camera for observing the electrodes of the chip.