JPH05142157A - Appearance inspecting device for soldered state - Google Patents

Abstract

PURPOSE:To obtain an appearance inspecting device which can improve the accuracy of appearance inspections by eliminating the dead area of laser light and can inspect the appearance of a soldered state by simultaneously bringing the upper surfaces of a chip and substrate into the visual field of a camera. CONSTITUTION:This appearance inspecting device is provided with a laser device 4 which emits laser light 6 for irradiating a substrate S from the top, optical element 8 which transforms the laser light 6 into fan-shaped slit light 6a, and optical element 11 which again transforms the slit light 6a into parallel slit light 6b. In addition, this inspecting device is also provided with a camera 12 which observes the reflected light 6c of the parallel slit light 6b by the substrate S from an obliquely upper position and a driving means 20 which integrally moves the laser device 4 and camera 12 in the vertical direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a soldering state visual inspection apparatus for fixing a chip to a substrate, which converts fan-shaped laser slit light into parallel slit light and irradiates it from above the substrate. By eliminating the blind spots when observing the soldering state with a laser device, the inspection accuracy of the visual inspection is improved, and by vertically moving these laser device and camera integrally, chips and solder can be attached to the camera. It is designed so that it can be incorporated into the field of view.

[0002]

2. Description of the Related Art After bonding a chip to a substrate by soldering,
A visual inspection is performed to determine the quality of the soldered state. Conventionally, such visual inspection has been performed by visual inspection, but in recent years, automatic inspection by optical means has become increasingly popular. The automatic visual inspection is generally performed by a camera, and the one disclosed in Japanese Patent Laid-Open No. 1-79874 is proposed. This product is equipped with a top camera for observing the chip from vertically above and a side camera for observing it from diagonally above. It is supposed to be inspected.

As described above, the conventional means in which the top camera and the side camera are combined has the advantages that the inspection area is wide and the inspection speed is fast. However, since the camera can detect two-dimensional plane information, but cannot detect height information, it has a disadvantage that it cannot perform visual inspection that requires precise height information such as visual inspection of solder. There is.

By the way, a laser device has been developed as means for obtaining accurate height information, and a visual inspection device in a soldered state using this laser device is known.
Next, this conventional appearance inspection apparatus in a soldered state will be described. FIG. 4 is a front view of this conventional appearance inspection apparatus in a soldered state, and FIG. 5 is a side view of the same.

A laser device 100 is arranged above a substrate S on which the chip P is mounted, and irradiates the substrate S with laser light 102. Reference numeral 103 denotes a kamaboko-shaped expander lens, which is housed in the laser device 100,
The laser light 102 is converted into fan-shaped slit light. 10
Reference numeral 4 denotes a camera, which is disposed obliquely above the substrate S and observes the reflected light of the laser light 102. H is solder for bonding the chip P onto the substrate S. Reference numerals 106 and 107 denote a base to which the laser device 100 and the camera 104 are fixed, and reference numeral 108 denotes an XY table that moves the substrate S in the XY directions.

This conventional apparatus has the above-mentioned structure, and its operation will be described below. As shown in FIGS. 4 and 5, the XY table 108 is driven to position the substrate S below the laser device 100, and then the laser device 10 is moved.
The laser light 102 is generated by driving 0. The laser light 102 is converted into a fan-shaped slit light by the expander lens 103 and irradiated on the substrate S, and the reflected light is observed by the camera 104 from obliquely above. In FIG. 3, A is the field of view of the camera 104, and the height h1 of the upper surface of the chip P and the height h2 of the upper surface of the substrate S are used as judgment elements to judge the quality of the soldered state.

[0007]

However, since the laser light 102 applied to the substrate S is fan-shaped slit light, all or part of the solder H enters the blind spot of the chip P as shown in FIG. Therefore, the entire surface of the solder H cannot be irradiated with the laser light 102, and there is a problem that the inspection accuracy is lowered.

Also, due to variations in the height of the upper surface of the substrate S, deviation of the installation position of the camera 104, etc., the field of view A of the camera 104 deviates in the vertical direction as indicated by the chain line and broken line in FIG. In some cases, only one of the upper surface of the substrate S and the upper surface of the substrate S can be captured in the field of view A of the camera 104. When the position of the field of view A is deviated in this way, only one of the heights h1 and h2 can be detected. Therefore, there is a problem that the quality of the soldering state cannot be determined. Of course, in the worst case, the upper surface of both the chip P and the substrate 5 may not be captured in the visual field A.

Therefore, according to the present invention, the blind spot of the laser beam can be eliminated to improve the inspection accuracy of the visual inspection, and the vertical deviation of the visual field of the camera can be eliminated, so that the upper surface of the chip and the upper surface of the substrate can be improved. It is an object of the present invention to provide a visual inspection device capable of incorporating the height into the visual field of a camera.

[0010]

To this end, the present invention provides a laser device for irradiating a substrate with laser light from above, an optical element for converting the laser light into fan-shaped slit light, and the fan-shaped slit light. An optical element for re-converting to parallel slit light, a camera integrally assembled with the laser device and observing the reflected light of the parallel slit light applied to the substrate from obliquely above, and these laser devices and the camera. A visual inspection apparatus in a soldered state is configured by a driving unit that moves up and down integrally.

[0011]

According to the above structure, the laser light generated by driving the laser device is converted into the fan-shaped slit light by the optical element, and then the fan-shaped slit light is re-converted into the parallel slit light by the other optical element. It is converted and irradiated onto the substrate. Therefore, the laser light is surely applied to the solder, and the reflected light is observed by the camera obliquely above to judge whether the soldering state is good or bad.

Further, by operating the driving means to move the laser device and the camera up and down integrally, the upper surface of the chip and the upper surface of the substrate can be taken into the visual field of the camera at the same time, and good appearance inspection can be performed.

[0013]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a perspective view of a soldering appearance inspection apparatus of the present invention. 1 is a bracket. The bracket 1 is attached to a Z table 20, and the Z table 20 is an XY table 2 which is movable in XY directions.
Is attached to. Reference numeral 3 denotes a main body, which is rotatably attached to the lower portion of the bracket 1. Reference numeral 4 denotes a laser device, which is provided inside the main body 3 and irradiates the substrate S with laser light 6 from above.

Reference numeral 7 is a reflecting mirror for the laser beam 6, which is arranged below the laser device 4. Reference numeral 8 denotes a semi-cylindrical expander lens as an optical element, which is provided on the side of the reflecting mirror 7 and converts the laser light 6 reflected by the reflecting mirror 7 into a fan-shaped slit light 6a. Reference numeral 9 is a reflecting mirror for this slit light 6a, and this expander lens 8
It is installed on the side of. Reference numeral 10 is a motor for X-direction scanning, and by rotating the reflecting mirror 9,
The laser light is scanned in the X direction. Reference numeral 11 denotes a lens as an optical element, which is provided below the reflecting mirror 9 in a pair, and re-converts the fan-shaped slit light 6a into parallel slit light 6b.

Reference numeral 12 denotes a camera, which is provided in the main body 3 and observes the reflected light 6c of the parallel slit light 6b irradiated on the substrate S from obliquely above. Reference numeral 13 denotes a reflecting mirror, which is provided below the camera 12 to reflect the reflected light 6
c is reflected to the camera 12 side. 14 is an XY table, and by driving this XY table 14,
The substrate S placed on this is moved in the XY directions. P is a chip mounted on the substrate S, and H is a solder for bonding the chip P to the substrate S.

Reference numeral 15 is a motor as a driving means, which is attached to the upper portion of the bracket 1. Reference numeral 16 denotes a rotating shaft of the motor 15, which is inserted into a through hole 17 formed in the bracket 1 and attached to the upper portion of the main body 3. As described above, the optical system such as the laser device 4 and the camera 12 is integrally assembled to the main body portion 3. Therefore, when the Z table 20 is driven, the optical system is integrally moved up and down, and the motor 15 is driven. Then, it rotates horizontally.

The present apparatus has the above-mentioned structure, and its operation will be described below. First, in FIG. 1, the XY table 2
Is driven to move the main body 3 onto the substrate S. Next, when the laser device 4 is driven to emit the laser light 6,
The laser light 6 is reflected by the reflecting mirror 7, converted into a fan-shaped slit light 6a by the expander lens 8, further reflected by the reflecting mirror 9, and transmitted through the lens 11 arranged below.

As shown in FIG. 2, while passing through the lens 11, the slit light 6a is reconverted into parallel slit light 6b and is irradiated so as to divide the chip P and the solder H in the X direction. In FIG. 1, the reflected light 6c of the irradiated parallel slit light 6b is reflected by the reflecting mirror 13 provided obliquely above and enters the camera 12, and as shown in FIG. By detecting the height h1 and the height h2 of the upper surface of the substrate S, the quality of the soldered state of the chip P is determined. As described above, this means converts the fan-shaped slit light 6a into the parallel slit light 6b and then irradiates the chip P and the solder H.
The blind spot as in the conventional means shown in FIG. 4 is eliminated, and the solder light H can be reliably irradiated with the slit light 6b.

Further, as shown by the chain line in FIG. 1, when the chip P is mounted on the substrate S at the rotation angle θ, the motor 15 is driven to horizontally move the main body 3 by this angle θ in the arrow direction. Rotate to correct the angle. In this case, since the optical systems such as the laser device 4 and the camera 12 are integrally assembled to the main body portion 3, the positional relationship of these optical systems does not change, and therefore, the slit light 6b divides the chip P. The optics can be integrally rotated horizontally so that they are illuminated.

As described with reference to FIG. 3,
Due to the variation in the height of the upper surface of the substrate S and the deviation of the installation position of the camera 12, either the upper surface of the chip P or the upper surface of the substrate S protrudes out of the visual field A of the camera 12, and the height of one of them is increased. Although only h1 or h2 may be detected, in this case, according to this means, the Z table 20 is driven to move the camera 12 up and down, and both upper surfaces are simultaneously captured in the field of view A. Detecting each height h1, h2,
The quality of the soldered state can be determined.

[0021]

As described above, according to the present invention, a laser device for irradiating a substrate with laser light from above, an optical element for converting the laser light into fan-shaped slit light, and the fan-shaped slit light are parallel to each other. Soldering state from an optical element that reconverts to slit light, a camera that observes the reflected light of the parallel slit light that is irradiated on the substrate from diagonally above, and a drive unit that vertically moves these laser device and camera integrally Since the appearance inspection device is configured, it is possible to improve the inspection accuracy of the appearance inspection by eliminating the blind spot when observing the soldering state with the laser device, and to integrate these laser device and camera. Adjust the camera height so that the upper surface of the chip and the upper surface of the substrate can be simultaneously captured in the field of view of the camera by moving them up and down to a good visual inspection of the soldered state It can be.

[Brief description of drawings]

FIG. 1 is a perspective view of an appearance inspection device in a soldering state according to the present invention.

FIG. 2 is a front view of a soldering state according to the present invention during appearance inspection.

FIG. 3 is an observation view according to the present invention and conventional means.

FIG. 4 is a front view of the appearance inspection apparatus according to the conventional means during the appearance inspection.

FIG. 5 is a side view of an appearance inspection device according to a conventional means.

[Explanation of symbols]

 6 laser light 6a fan-shaped slit light 6b parallel slit light 6c reflected light 8 optical element 11 optical element 12 camera 20 driving means H solder S substrate

Claims (1)

[Claims] 1. A laser device for irradiating a substrate with laser light from above, an optical element for converting the laser light into fan-shaped slit light, and an optical element for re-converting the fan-shaped slit light into parallel slit light. A camera for integrally observing the reflected light of the parallel slit light with which the substrate is irradiated by being integrally assembled with the laser device, and a driving means for integrally moving the laser device and the camera up and down. A visual inspection device in a soldered state characterized by the above.