JP2001194121A - Method and apparatus for visual inspection of electronic component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and apparatus for visual inspection of electronic components whereby the visual inspection can be automatically carried out with high efficiency through little operational effort without requiring manual operation such as inversion of samples for inspection. SOLUTION: As a plurality of electronic components to be inspected are sequentially flown in air toward a component capturing area at predetermined time intervals, an image of the surface part of each of the electronic components is taken by an electronic camera and the visual inspection of the electronic components is continuously carried out based on the images taken.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an electronic component, in particular,
The present invention relates to a method and an apparatus for inspecting the appearance of a semiconductor chip such as an LD element or a microelectronic component such as a chip capacitor.

[0002]

2. Description of the Related Art Conventionally, an electronic camera such as a CCD (Charge Coupled Device) camera has been used in a production line of an electronic component such as a semiconductor integrated circuit device, an LD device (laser diode device), a resistor, a capacitor or a coil device. By using an intermediate product of electronic components, for example, a semiconductor integrated circuit chip, or a so-called intermediate product in which a chip capacitor or the like is soldered to a lead frame, such an intermediate product is completed by applying a resin mold or the like. The surface of the finished part or the like is photographed, and a photographed image such as a reproduced video displayed on a display device by a photographed image signal from the electronic camera is used. Inspection on the resin molding condition of the finished parts and the soldering condition of the leads, that is, It has been known to perform the watch inspection.

However, in the above-described conventional appearance inspection, it is necessary for an operator to take the electronic components of the sample to be inspected one by one and bring the surface of the electronic components to be inspected closer to the electronic camera for focusing. is there. In particular, when performing a visual inspection of a plurality of surface parts such as an upper surface, a lower surface, a left side surface, and a right side surface of an electronic component, the focusing operation must be performed a plurality of times, and such a visual inspection man-hour is considerably large. However, this has been a major obstacle in reducing the manufacturing cost.

In the case where the electronic components are ultra-small such as an LD chip or a chip capacitor, when photographing each surface portion of the chip, a worker holds the chip by using tweezers or the like and flips the chip one by one. The efficiency of the appearance inspection of such a chip-type electronic component was not great.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems in the appearance inspection of electronic parts of the conventional type, and its main purpose is to prevent the appearance inspection person from reversing the sample to be inspected. An electronic component that can be performed automatically and with high efficiency without requiring any manual work and with little work effort, and that is useful for visual inspection performed in the mass production process of chip-type electronic components. An object of the present invention is to provide a visual inspection method and apparatus.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a method for inspecting a plurality of objects to be inspected on a straight horizontal moving path of a predetermined length installed at a predetermined height position toward a front end thereof. The electronic components of the sample are moved in a row in a row at a predetermined speed Vs, and the surface of the electronic components in the electronic component row is moved from an injection port provided before the front end of the horizontal moving path to the electronic component. The compressed air flow is injected at a constant pressure at an inclination angle with respect to the horizontal movement direction of the electronic component, and the electronic components having received the injection pressure are propelled forward at a predetermined speed Vf greater than the moving speed Vs, so that these electronic components are propelled forward. Parts
Sequentially, from the front end of the horizontal moving path at a substantially constant time interval, it is caused to naturally fall into a component capturing area arranged in a lower part in front of the horizontal moving path, and from the front end of the horizontal moving path. , One after another, the surface portion of each electronic component that flies in a substantially constant trajectory toward the component capture area,
At least one, preferably two to four electronic cameras arranged at appropriate positions in accordance with the flight trajectory are photographed to obtain photographed images of the surface of each electronic component, and based on these reproduced photographed images, And performing an appearance inspection.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to the accompanying drawings showing one embodiment thereof. The visual inspection apparatus of this embodiment is suitable for visual inspection of a vertically long hexahedron of microelectronic components, that is, four surfaces excluding both vertical end faces of a rectangular parallelepiped chip capacitor.

In FIG. 1, which shows a schematic configuration of the entire appearance inspection apparatus, the apparatus is indicated by the numeral 1 in general. This device 1 is roughly composed of a parts feeder 3,
It comprises a nozzle member 7, a component capturing container 17, an electronic camera 19, and an image processing unit 21. These main components 3, 7, 17, 19 and 21 are housed in the rack 2. The chip capacitor 4 to be inspected in this apparatus is formed by baking an electrode thin film on the surface of a rectangular parallelepiped high dielectric ceramic chip.
05 type (1.0mm × 0.5mm × 0.5mm) or 0402 type (0.4mm
(mm × 0.2mm × 0.2mm) chip capacitor.

The parts feeder 3 is, for example, a commercially available parts feeder CS11-10-01 (manufactured by Murata Seiko Co., Ltd.)
Can be used. FIG. 3 shows a detailed side view of the parts feeder 3.

[0010] For example, approximately 4000 chip capacitors 4 for one production lot are randomly placed in the receiving section 5 of the parts feeder 3 and supplied to the receiving section 5. 6, the longitudinal axes of the chip capacitors 4 are aligned in the carrying direction by a known method (vibration carrying method in the present embodiment), and the chip capacitors 4 are successively placed one by one in a state where the longitudinal end surfaces of the chips are in contact with each other. Constant speed Vs,
For example, it is fed out at about 200 cm / min. The chip feeding speed from the supply port 6 in the parts feeder 3 can be adjusted by a speed adjusting knob (not shown), and the shape and dimensions of a chip capacitor (electronic component) to be carried out or a component (chip) flight trajectory to be described later. It can be adjusted according to the conditions.

The nozzle member 7 is formed by combining a stainless steel base member 8 and two stainless steel half members 9 as shown in FIG. According to the shape of the electronic component to be inspected, that is, the chip capacitor 4 in this embodiment, the nozzle member 7 has a rectangular cross section and a cross section of the chip capacitor 4 as shown in FIG. A straight through hole 10 having a cross-sectional shape slightly larger than the cross-sectional shape is formed. The nozzle member 7 is formed with a through hole 12 extending forward with a predetermined inclination angle with respect to the longitudinal axis of the through hole 10, and an inner wall surface of the through hole 10 is formed inside the front opening end 11. In other words, a slit-shaped injection port 13 is formed at a position on the front side.

The nozzle member 7 is mounted horizontally at the same height as the supply port 6 of the parts feeder 3, and the rear opening end of the through hole 10 of the nozzle member 7 is connected to the supply port of the parts feeder 3. It is directly connected to 6. In this way, the through-hole 10 is connected to the front opening end 11 of the through-hole 10 by the chip capacitor 4 continuously and successively fed from the supply port 6.
, A linear component movement path is formed that guides the robot so as to move forward in a line in a state where the vertical end surfaces are in contact with each other. On the other hand, the through-holes 12 provided in the nozzle member 7 in an inclined shape are connected to a compressed air source (not shown) that outputs compressed air at a constant pressure, and the compressed air flow from the compressed air source is supplied to a slit-shaped injection port A compressed air flow path is formed for injecting compressed air toward the front surface of the first chip capacitor 4 in a row of chip capacitors that moves forward in the through hole 10 from 13.

As shown in FIG. 5, the parts feeder 3
From the component supply port 6 of the chip capacitor row which is continuously fed out one after another into the through hole 10 of the nozzle member 7 connected to the supply port 6, and advances through the through hole 10 at a substantially constant speed Vs. In the present embodiment, the surface of the chip capacitor 4, that is, the upper surface of the chip capacitor 4, receives compressed air pressurized to a constant pressure injected from the slit-shaped injection port 13, As a result, the chip capacitor 4 moves toward the front opening end 11 of the through hole 10 at a higher speed V than the moving speed Vs of the capacitor 4.
The chip capacitor 4 is caused to travel at f, and jumps out from the front opening end 11 while maintaining a horizontal posture. In this manner, the chip capacitors 4 in the chip capacitor row that moves forward through the through holes 10 of the nozzle member 7 in a tandem manner have substantially the same mass, and are applied to each chip capacitor 4 from the injection port 13. Since the air injection pressure is substantially constant, the initial speed Vo that protrudes from the front opening end 11 of each chip capacitor 4 is equal to the traveling speed Vf described above.
Therefore, each of the chips 4 in the above-mentioned chip capacitor row is separated from the front opening end 11 of the nozzle member 7 by
As shown in FIG. 6, the robots sequentially fly out at substantially equal time intervals, and fall naturally while drawing a substantially parabolic flight trajectory or along a substantially parabolic flight trajectory 15.

At a suitable position in front of and below the front opening end 11 of the nozzle member 7, as shown in FIGS. 1 and 2, a component capturing opening 18 at the top, that is, a component capturing region having a component capturing area is provided. Container 17 is arranged. More specifically, the component capturing container 17 is located in a vertical plane including a flight trajectory 15 of the chip capacitor 4 which protrudes from the front opening end 11 of the through hole 10 of the nozzle member 7 and flies in the air. Is installed at a position where it falls naturally into the component capturing opening 17 (also referred to as a component capturing area). The flight trajectory of the tip 4 is determined by the front opening end 11 of the nozzle member 7.
Is calculated according to the natural fall equation derived according to Newton's law as the initial velocity Vo at.

FIG. 6 shows that the mass of the chip capacitor 4 is about 0.
0013g shows a parabolic flight trajectory when the initial flight speed Vo is 200 cm / sec. In this case, the chip capacitor 4 is intermittently connected from the front opening end 11 of the nozzle member 7.
Is about 0.1 second, so that about 600 chip capacitors 4 are inspected per minute. The time interval can be set to about 0.05 to 0.2 seconds for the above-described 1005 type or 0402 type chip capacitor 4. The initial speed Vo of the chip capacitor 4 is basically determined according to the shape and mass of the chip capacitor to be inspected and the moving speed Vs fed from the parts feeder 3.

As shown in FIGS. 1 and 2, four electronic cameras 19 are arranged in front of the front opening end 11 of the nozzle member 7 and near the front opening end 11. In these electronic cameras 19, focusing is adjusted in advance in accordance with the flight trajectory of the chip capacitor 4 that has protruded from the front opening end 11 of the nozzle member 7, and the operation timing of the shutter of each electronic camera 19 is adjusted. The surface portions on the four surfaces of the flying chip capacitor 4 are respectively photographed: upper, lower, left and right. These electronic cameras 19 are configured using, for example, a CCD (capacitively-coupled device), and are each connected to an image processing unit 21 (see FIG. 1).
A digital image signal, that is, a bit signal, which represents a captured image of the surface of the chip capacitor captured by the above, is transmitted to the image processing unit 21.

The image processing unit 21 performs image processing by a known method on the basis of photographed image signals of the four surface portions of the chip capacitor 4 transmitted from the four electronic cameras 19, and processes the photographed image. Is generated, and the reproduced captured image signal is represented by, for example, C
The image is transmitted to a video monitor 23 using an RT (cathode ray tube) and the captured image is displayed on a CRT screen. At the same time,
In the arithmetic processing unit of the image processing unit 21, based on the image data signal representing the appearance inspection criteria for the surface portion of the chip capacitor 4 and the reproduced captured image signal,
An inspection and determination regarding the appearance of the chip capacitor 4 is performed. The appearance inspection determination can be performed with respect to the shape, size, or adhesion state of chips, cracks, or attached electrode films on the surface of the chip capacitor 4.

In the judgment processing of the visual inspection, when the judgment measured value based on the photographed image is within the range of the judgment reference value, it is judged as “non-defective”, and the judgment measurement value is within the range of the judgment reference. When it is out of the range, it is determined to be "defective". Based on these determination signals, the quantity of non-defective products and defective products is displayed on a known digital counter 24 provided in the operation box 20 (only the count display portion of the digital counter is shown in FIG. 1). The appearance inspection determination processing by such an arithmetic processing unit is related to the determination processing, that is, the flying chip capacitor 4 corresponding to the image captured by the electronic camera 19 will be described in detail later as shown in FIG. The process is completed before the compressed air injection nozzle mechanism 28 passes through a position corresponding to the set position.
When the result of the visual inspection is "defective", a signal indicating the "defective" is transmitted to the compressed air injection nozzle mechanism 28.

An air injection nozzle mechanism 28 for injecting compressed air, as shown in FIGS. 2 and 6, protrudes from the front opening end 11 of the through hole 10 of the nozzle member 7 and flies in the air. 4 is located in the vertical plane including the flight trajectory 15 of the chip 4 and in the vicinity of the flight trajectory 15 of the chip 4, and the defective determination component capturing container 27 is located at a position facing the tip of the compressed air injection nozzle 29. Be placed.

When the compressed air injection nozzle mechanism 28 receives the "defective" judgment signal from the image processing unit 21, it operates and the compressed air injection nozzle 29 in the injection nozzle mechanism 28 determines the defective. A compressed air pressure (this is also referred to as an external force) is instantaneously applied in a lateral direction with respect to a traveling direction of the corresponding flying chip capacitor 4. The defective product judgment chip 4 which has received the compressed air pressure has its trajectory 1
5 and is captured in the defective determination component capturing container 27 disposed at a position facing the tip of the compressed air injection nozzle 29. On the other hand, when the compressed air injection nozzle mechanism section 28 receives the "good" determination signal from the image processing unit 21, it does not operate and holds the closed state of the compressed air injection nozzle 29. Such a chip capacitor 4 has a flight orbit 15
And falls naturally into the component capturing opening 18 of the good determination component capturing container 17.

In the appearance inspection apparatus of the above embodiment, the parts feeder 3 is not limited to the vibration transportation type, and similarly, the longitudinal axis of the chip of each sample to be inspected is aligned with the supply port 6 and continuously. Any other type, for example, a belt conveyor type may be used as long as it is fed out.

Further, the nozzle member 7 extends toward the front opening end 11 of the through hole 10 at a predetermined inclination angle with respect to the longitudinal axis of the through hole 10 and is not shown in the same manner as the above-described inclined through hole 13. Two or three inclined through-holes may be formed, and a slit-shaped injection port corresponding to each of the inclined through-holes may be formed in a wall portion inside the front opening end 11 of the through-hole 10. . With this configuration, the nozzles 7 are fixed to the left and right side surfaces or the both side surfaces and the upper surface of the chip capacitor 4 in the chip capacitor row moving forward in the through hole 10 of the nozzle member 7 from the injection hole of each through hole. By blowing the compressed air flow, the chip condenser 4 can be more stably accelerated.

[0023]

In the appearance inspection of the electronic component according to the present invention, the inspector does not require any manual work as in the conventional system, and the entire process of the appearance inspection is completely automatically performed. And can be performed with high efficiency. In particular, the man-hours required for appearance inspection of chip-type microelectronic components are ms.
(Milliseconds), and if applied to the mass production process of such microelectronic components, it is possible to effectively reduce the manufacturing cost.

[Brief description of the drawings]

FIG. 1 shows a front view of the entire chip capacitor appearance inspection apparatus according to the present invention.

FIG. 2 is a plan view of a main part of the appearance inspection apparatus.

FIG. 3 is a side view of a parts feeder applicable to the appearance inspection apparatus.

FIG. 4 is an exploded perspective view of a nozzle member used in the apparatus of the present invention.

FIG. 5 is a conceptual diagram for explaining a mechanism for ejecting an electronic component in the nozzle member.

FIG. 6 is a graph showing a time chart of a flight trajectory of an electronic component in the visual inspection device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 electronic component appearance inspection device of the present invention 3 parts feeder 4 chip capacitor (electronic component) 6 supply port 7 nozzle member 10 through hole (component moving path) 11 front opening end 12 inclined through hole (compressed air flow path) 13 Injection port 15 Flying trajectory of electronic component 17 Good determination component capture container 18 Component capture opening (component capture area) 19 Electronic camera 21 Image processing unit (image processing processor) 23 Video monitor 27 Defective determination component capture container 28 Compressed air injection nozzle mechanism Part 29 Compressed air injection nozzle

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Tsuyoshi Yura 43F, Mercurio Kyoto 207, Higashikujo Shimodenda-cho, Minami-ku, Kyoto, Kyoto 2F065 AA49 AA51 BB05 BB15 CC25 DD06 FF04 JJ03 JJ05 JJ09 JJ26 LL30 NN11 PP11 QQ03 QQ25 QQ51 RR05 RR06 RR09 SS02 SS03 SS13 TT01 TT03

Claims (12)

[Claims] When a surface of an electronic component is photographed and the appearance of the electronic component is inspected based on the photographed image, the surface of the electronic component is placed on a linear horizontal moving path of a predetermined length provided at a predetermined height position. Moving the electronic components of a plurality of samples to be inspected toward the front end in a line at a predetermined speed Vs; at a position before the front end of the horizontal moving path, a predetermined pressure is applied at an inclination angle to the horizontal moving direction. The compressed air is injected toward the surface of the electronic component in the row of electronic components, and the electronic component receiving the injection pressure is moved at the moving speed V
By moving the electronic component on the horizontal moving path at a predetermined speed Vf greater than s, the electronic components are sequentially sequentially separated from the front end of the horizontal moving path at a substantially constant time interval to a lower part in front of the front end. Jumping out so as to fall naturally into the component capturing area set in the electronic camera; and, from the front end of the horizontal moving path, the surface of each electronic component flying toward the component capturing area one after another. Obtaining a photographed image of the surface of each electronic component by photographing the electronic component. 2. An image of a surface portion of an electronic component flying from a front end of a horizontal moving path to a component capturing area, and the electronic component is taken until the captured electronic component reaches the component capturing area. Inspection of the chip appearance is completed based on the photographed image of the electronic component, and as a result, when it is determined that the electronic component is defective, an external force is instantaneously applied to the flying electronic component corresponding to the defective product determination, whereby the electronic component is inspected. While forcibly deviating from the trajectory flying toward the component capturing area, when the determination result is determined to be non-defective, an electronic component corresponding to the non-defective determination is thrown into the component capturing area. Item 1. The method according to Item 1. 3. The initial velocity Vo of each electronic component jumping out of the front end of the horizontal moving path by adjusting the injection flow rate of the compressed air in accordance with the form and weight of the electronic component of the sample to be inspected.
The method according to claim 1 or 2, wherein the time interval T is adjusted. 4. An electronic component of a sample to be inspected is a chip capacitor having a rectangular parallelepiped shape, and sequentially from a front end of a horizontal moving path.
2. A time interval for ejecting the chip capacitor in the direction of the component capturing area is set to about 0.05 to 0.2 second.
A method according to claim 3. 5. The method for inspecting the appearance of a chip capacitor of a sample to be inspected, wherein the shape, size, or state of adhesion of a chip, a crack, or an attached electrode film on a surface portion of the chip capacitor is evaluated. The method according to claim 4. 6. An apparatus for photographing a surface portion of an electronic component and inspecting the appearance of the electronic component based on the photographed image, wherein a supply port communicated with a storage portion for storing electronic components of a plurality of samples to be inspected. A part feeder, which feeds an electronic component at a predetermined speed Vs continuously from a nozzle member; a nozzle member horizontally disposed at a predetermined height position, and a linear component moving path communicating with a supply port of the part feeder. A through-hole that forms a compressed air flow path extending at a predetermined angle of inclination with respect to the longitudinal axis of the through-hole, and forms an injection port on a wall portion inside the front opening end of the through-hole. A nozzle member having a hole; a compressed air source for supplying compressed air at a constant pressure to the through-hole of the nozzle member; a component capturing opening disposed at the top of the nozzle member, which is disposed in front of and below the front opening end of the nozzle member. Parts with In a vertical plane including a flight trajectory of the electronic component of the sample to be inspected, which jumps out of the front opening end of the through-hole of the nozzle member and falls naturally toward the component capturing opening of the component capturing container. An electronic camera disposed on the electronic component for photographing a surface portion of the electronic component in flight; and an electronic camera connected to the electronic camera for reproducing a captured image based on an image signal from the electronic camera and for reproducing the reproduced captured image of the electronic component. An image processing unit for judging the quality of the appearance of the electronic component in comparison with an appearance standard; a plurality of electronic components to be inspected being brought into contact with each other through a through hole of the nozzle member from the parts feeder to determine At the same time, the compressed air is supplied at a speed Vs, and compressed air is supplied from the compressed air source to the inclined through-hole of the nozzle member at a constant pressure. The compressed air is injected toward the surface of the electronic component in the electronic component row moving in a line in the through hole, and the electronic component receiving the injection pressure is subjected to the predetermined speed Vf greater than the moving speed Vs. By running in the through hole, the plurality of electronic components from the front opening end of the through hole,
The appearance inspection of the electronic component is continuously performed through the electronic camera and the image processing unit while being sequentially jumped out at a substantially constant time interval so as to naturally fall into the component capturing opening of the component capturing container. A visual inspection device for an electronic component. 7. The electronic component, wherein the electronic component is located in a vertical plane including a flight trajectory of an electronic component flying out of a front opening end of a through hole of the nozzle member and flying toward a component capturing opening of the component capturing container. In the vicinity of the flight trajectory, an air injection nozzle capable of applying an impact pressure in a direction transverse to the traveling direction of the flying electronic component is arranged, and a chip appearance inspection based on a photographed image of the electronic component traveling in the flight trajectory is performed. When a defective product is determined, an external force is instantaneously applied from the air injection nozzle to the flying electronic component corresponding to the defective product determination to forcibly deviate the electronic component from the flight trajectory. An apparatus according to claim 6. Further, another component capturing container is provided at a position opposite to the air injection nozzle, and the pressure of the electronic component is forcibly deviated from a predetermined flight trajectory by the injection air pressure from the injection nozzle. The apparatus according to claim 7, wherein the electronic parts determined to be “good” are collected. 9. A two- or three-compressed air passage extending at a predetermined angle to the longitudinal axis of the through hole of the nozzle member, and a wall inward from a front opening end of the through hole. The device according to any one of claims 6 to 8, wherein an injection port portion of each of the compressed air flow paths is formed in the portion. 10. The device according to claim 6, wherein the electronic camera is a CCD camera. 11. A judgment criterion for an appearance inspection of a chip capacitor in an image processing unit is based on a shape, a size, or an adhesion state of a chip, a crack, or an attached electrode film on a surface portion of the chip capacitor. Item 11. The apparatus according to any one of Items 10. 12. The electronic component of the sample to be inspected is a rectangular parallelepiped chip capacitor, and the appearance of the four sides of the chip capacitor excluding both longitudinal end surfaces is inspected.
Apparatus according to any of claims 11 to 13.