WO2002054478A1

WO2002054478A1 - Apparatus for inspecting surface mounted chip

Info

Publication number: WO2002054478A1
Application number: PCT/KR2001/001876
Authority: WO
Inventors: Hak Chul Kang
Original assignee: Yient Co., Ltd.
Priority date: 2000-12-29
Filing date: 2001-11-07
Publication date: 2002-07-11
Also published as: KR20020007123A; JP2004532973A; TW550771B; KR100375983B1

Abstract

Small components vision inspection requires precise and accurate placement of components for camera to collect the component images. The new small 6-side component handling system can reliably and accurately place small components on the edge of a rotating disc for precise inspection at a high speed.

Description

APPARATUS FOR INSPECTING SURFACE MOUNTED CHIP

TECHNICAL FIELD Surface Mount 6-side Component Handling, Vision Inspection and Sorting System

BACKGROUND ART

The invention is a part of system which can accurately and reliably inspect the surface of surface mount electrical components such as MLCC (Multi-Layer Ceramic Capacitor). The invention consist of the housing block and the rotating assembly that can supply compressed air and vacuum, the lower and upper discs along with the a set of cameras. The invention is designed to accurately and reliably inspect the surface of surface mount electrical components such as MLCC

(Multi-Layer Ceramic Capacitor).

As the demand for faster and more compact computer increases, the computer industry is demanding smaller and efficient electrical components. In addition, the trend in the high tech consumer electronic goods is becoming smaller thus smaller electrical components.

Today these electrical components such as MLCCs are becoming so small in the units of tenth of millimeters. In a typical computerized product, a several hundred to thousand components are used in a component. However, small component size makes it quite difficult for human eyes to inspect and sort defective components from the good. The most commonly used inspection system employs a rotating glass plate to position and inspect the component. As the glass plate is rotated, the components are placed on the outer edge of the glass plate. At this point, the system takes a picture and analyzes the component for any defect.

Previous technology compares the images taken from the component against the standard pattern sets. If the image significantly deviates from the pattern then the component is considered to be defective. The problem, however, occur when outside illumination or contaminants alters the image, causing the system to sort fair component in a defect bin.

Another technical challenge is the component placement system using the glass plate. Too often the components are not placed accurately on the edge of the plate, causing the system to categorize the component as defective. Moreover, poorly designed ejecting system make it difficult for the system to accurately place the components that are determined to be bad or good accurately into the respective bins at a high speed.

Hence the technical objective is to overcome these mechanical short-comings of the previously designed vision inspection system. First the system ought to place the component accurately and reliably, allowing the system to collect accurate images of the component. Second, the system should be designed to remove any contaminants that may distort the image. Finally, the handling ought to be gentle, not damaging the component during the handling process. DISCLOSURE OF INVENTION

To achieve the stated objective, the vision inspection system consist of housing block, which two discs can be attached on the face and rotated, the compressed air and vacuum supply system, and the set of camera. In addition, the component feeder is attached to the system to continuously supply the component reliably.

The discs consist of two round flat plate put together. The disc has a number of slots through which the vacuum is supplied. Air holes equal to the number of vacuum slots are found on one side of the disc through. On the edge of disc is the v-slot in which the components are placed. Air holes are placed approximately 0.03 to 0.05mm apart.

To supply the vacuum to the air slots on the disc, the housing block houses the compressed air and vacuum chambers Please refer to the attached Fig. Fig 1 is a side view of the vision inspection machine while Fig 2 is the frontal view. On top of base (2) is the fixed housing block (4) which can be rotated and is connected to lower and upper discs (14, 16). Attached to the upper disc (14) is the feeder (12). Near the discs are the four cameras (18a, 18b, 18c, 18d).

Inside the housing block (4) is the rotational axle (42) which is connected to motor and vacuum supply unit, and compressed air supply unit. Solenoid sorting mechanism (20) is located below the lower disc. Attached to the solenoid sorting mechanism (20) is the guide block (50) which directs the sorted components to the collection bins.

Fig 3 is a schematic diagram of the lower and upper discs (14, 16). The Fig details the connecting point of the lower (14) and the upper disc (16). The disc contains 50 vacuum slots (44) which are directed to the center of the disc. The two plates forming the disc are held air tight to prevent vacuum leakage. At the top where the two plates are forging is the v-slot where the 6-side component can be placed.

The disc is attached to the rotational axle (42) which is attached to the protrusion (6) of the housing block (42). The upper disc (14) rotates in counter-clockwise direction while the lower disc (16) rotates in clockwise direction. Fig 3 only contains simplified a diagram of the main plate.

Fig 4 contains a schematic diagram of the upper and lower discs and housing blocks. The protrusions (6) of the housing block (4) is in contact with 50 air holes (62) located on the surface of the supporting plate on the discs (14, 16). The holes (44) are connected to the vacuum chambers located inside the discs which are connected to the vacuum slots (62). As shown in the Fig,, the distance between each air hole is approximately 0.03 to 0.05mm.

Fig 5 is a view of compressed air/vacuum separation chamber insider the housing block. Air/vacuum separation chamber (64) inside the housing block (4) is connected to the compressed air supply via air duct (42).

As shown in Fig 1 and 2, the cameras (18a, 18b, 18c, 18d) are positioned around the discs (14, 16). The components supplied to the upper disc (16) are placed on the v-slot, exposing the two sides. The camera (18a, 18b) takes the picture of the two exposed sides. As the upper disc (16) rotates to the bottom, the component is transfer to the lower disc (16) and placed on the v-slot of the lower disc. As the disc rotates, cameras (18c, 18d) takes the picture of the two exposed surface of the component

Components (1) being supplied continuously through the feeder (12) on to the rotating disc (14) and placed on the v-slot evenly. The components are located at the tip of the vacuum channels (46). Vacuum is supplied to the channels (46) which are connected to the air duct (44) and vacuum slots. Therefore, the components are held by the vacuum and are able to rotate with the disc without falling off the disc surface.

After a picture of the exposed side of the components is taken, the component (1) located on disc (14) rotates in the counter-clockwise direction until it reaches the lowest point. At this point, the vacuum holding the component ceases to be supplied from the vacuum channel (46). As the disc (14) rotates the air holes (44) on the side of the disc (14) are in contact with the vacuum slot located on the surface of the protrusion (6) of the housing block (4). As the component reaches the lowest point, the air ceases to be supplied to air hole (44) since it reaches the air/vacuum separation chamber. At this point, the component becomes detached from the vacuum channel (46), and transfers to the edge of lower disc (16). As the component continues to rotate the camera takes the picture.

As the vacuum is used most of the contaminants are removed. Moreover, the component position is consistently accurate and reliably. There is a little possibility for friction or collision with another components.

BRIEF DESCRIPTION OF DRAWINGS

Fig 1 and 2 are frontal and side view of SMT chip component inspection system. Fig 3 is a schematic diagram of housing block in which the lower and upper rotating discs are attached.

Fig 4 details how the discs are attached to the housing block. Fig 5 is details the inside of housing block which contains the vacuum/air separation chamber.

Fig 6 outlines the moving path of components placed on the lower and upper discs.

Fig 7 describes the position of component placed on the disc

Components on the Drawings:

2 : Base

4 ; Housing Block

12 : Feeder

14, 16 : Lower and Upper Disc 18a, 18b, 18c, 18d : Camera

20 : Solenoid Sorting Mechanism

44 : Air hole

50 : Guide Block

62 : Semi-circular Vacuum Slot 64 : Air/Vacuum Separation Chamber

BEST INVENTION FOR CARRYING OUT THE INVENTION

The system is designed to inspect MLCC and other SMT components. The housing block is designed with axles, which hold the rotating discs, and the compressed air/vacuum supply system. In addition, the system also has a pair of camera around each disc.

The above system is complemented with the component feeding mechanism which is situated near the upper rotating disc. The discs described within consist of two round plates put together.

The disc described within has air holes on the side of one of the plates. On the face of the plates are the air channels slots which are directed outward from the center. The two plates can be put together to form an airtight disc with the air channels directing the air flow.

On outer edges of the discs, the two plates form v-slot to place the component.

The upper and lower discs rotate in the opposite direction. The protruded contact area between the above mentioned housing block and the surfaces of lower & upper discs is semi-circular vacuum slot.

The vacuum slot on the surface of the housing block is designed to face the air holes - thereby supplying the vacuum to the air channels on the disc - existing on the surface of the disc.

Surface of the housing block that is comes into contact with the discs is slightly protruded.

The two discs attached to the protruded surface of the housing block are positioned approximately 0.03 to 0.05mm distance. On the lower part of the vacuum slot, the vacuum/air separation chamber exist to cease the vacuum supplies to the air channel of the disc.

In the air/vacuum separation chamber on the housing block is the air duct which supplies compressed air. The compressed air is blown through the air holes and channels to detach any components that are held to the outer edge of the disc.

Claims

1. In the vision inspection system that is designed to inspect MLCC and other SMT components, the system consist of 1) The described housing block;

2) The described housing block with the rotating axles;

3) The two - upper and lower - discs attached to the housing block through which compressed air and vacuum is supplied to the discs via the housing block; Cameras which are centered around the discs.

2. In connection with Claim 1, the system is complemented by the component feeding mechanism which is positioned near the top portion of the upper disc.

3. In connection with the discs mentioned in Claim 1, each disc consists of two round plates put together.

4. In connection with Claim 3, the round plates that construct the disc have numerous air channels that radiates from the center.

On one side of the place are the holes which are connected to air channels to supply the compressed air and vacuum. The two plates put together forms an airtight disc with vacuum/compressed air flow is directed only through the air channels.

5. In connection with Claim 4, on and around the outer edges of the discs which are form ed by the two round plates is the v-shape slot to position the component.

6. In connection with Claim 3, the upper and lower discs rotate in the opposite direction.

7. In connection with Claim 1, the contact area between the above mentioned housing block and the surfaces of lower & upper discs is protruded from the housing block. On the surface of the contact area is the semi-circular vacuum slot.

8. In connection with Ciaim7, the semi-circular vacuum slot is positioned so to be contact with the air holes found on the surface of one of the plates.

9. In connection with Claim 7, a small cap between the upper and lower discs exists when the two discs are attached to the protruded areas of housing block

10. In connection with Claim 7 and 9, the gap between the two discs attached to the protruded surface of the housing block is approximately 0.03 to 0.05mm.

11. In connection with Claim 7, on the lower part of the semi-circular vacuum slot the vacuum/air separation chamber exist to supply compressed air to a selected air channel of the disc.

12. In connection with Claim 11, the vacuum/air separation chamber is connected to the compressed air source via the air duct formed inside the housing block is the air/vacuum separation chamber.

13. In connection with Claim 12, the contact area between the air/vacuum separation chamber and the disc is made of the material that allows movement. Moreover, the material is elastic and is able to absorb the pressure exerted on the disc via vacuum.