JPH1163951A - External appearance inspection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an external appearance inspection device capable of performing ball measurement such as a ball pitch, a ball radius, a ball position degree at a high speed, and performing a mark package void inspection in the same tact. SOLUTION: There are provided a pickup device 1 conveying a package P received in a tray T1 to a measurement position S3 at a position in which a terminal face is directed downward; mark package void inspecting means disposed above the pickup position S1; and measuring means 4, 5 inspecting a terminal side of the package P conveyed to the measuring position S3 by imaging measurement (or laser displacing measurement). With this arrangement, the package void inspecting means inspects a next package P in a process in which the pakage P which is previously finished inspection is conveyed to the measuring position S3, whereby a mark package void inspection is performed in the same tact.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a visual inspection device for a BGA / CSP package or the like.

[0002]

2. Description of the Related Art As a visual inspection apparatus for a BGA / CSP package, there is a laser displacement measuring apparatus.

This laser displacement measuring apparatus scans a back surface (terminal side) of a package with a laser beam while the package is stored in a tray in an inverted state, and thereby warps the package and shapes and pitches of the terminals. It is a device for non-contact measurement.

In a laser displacement measuring apparatus for measuring a ball grid array type package, in addition to measuring the presence or absence of a ball, a ball pitch, a ball diameter and a ball position, a ball coplanarity (ball) is measured from the terminal side of the package. A three-dimensional laser displacement measuring device for measuring the flatness of an array has been put to practical use.

[0005]

However, BGA / C
The SP package is usually stored in a tray with the terminals facing down (positive direction).

Therefore, using a laser displacement measuring device,
When performing a terminal inspection of a ball type BGA / CSP package, it is necessary to perform ball measurement with a laser displacement measuring device in a state where the tray is inverted and the package posture is inverted. There is a drawback that marks such as a company name and a product number attached by (or a laser marker) cannot be inspected.

In addition, in the laser displacement measuring device, the inspection is performed with the ball facing upward, so that when a defective product comes out and is refilled with a good product, the pickup device or the like comes into contact with the ball side. There is a possibility that the ball may be damaged.

In addition, if the tray for the manufacturing process and the shipping tray are different after the completion of the inspection for the in-tray inspection, an extra transfer operation is required as one process.

Further, the scanning of the laser beam is performed along the column direction or the row direction of the ball array. However, the scanning position of the laser beam is not necessarily adjusted due to the positioning error of the package storage tray with respect to the inspection stage. There is also a problem that the ball coplanarity measurement is not always reliable, because it does not always coincide with the vertex.

The present invention has been made in view of such circumstances, and enables ball measurement such as ball pitch, ball diameter, and ball position to be performed at a high speed without reversing the package while maintaining a normal posture. It is an object of the present invention to provide a visual inspection apparatus capable of performing mark and package void inspection within the same tact.

[0011]

In order to achieve the above object, an appearance inspection apparatus according to the present invention is a package such as a BGA / CSP type IC, which has a mark on an upper surface or the like and a terminal for electrical connection on a rear surface. A device for inspecting the appearance of a package formed, as shown in FIGS. 1 and 2, picking up a package P stored in a tray T1 with a terminal surface facing down and measuring it at a measurement position S3. And package void inspection means (CCD camera 3) arranged above the pickup position S1 of the package P from the tray T1.
And the package P transported to the measurement position S3 while the upper portion is held by the pickup device 1 (FIG. 3).
(See FIG. 2), the measuring device (CCD cameras 4 and 5) for inspecting the terminal side by image processing measurement (or laser displacement measurement), and the package void inspection device has completed the mark / package void inspection first. Package P
While the pickup device 1 is being transported to the measurement position S3, it is characterized in that the next package P located at the pickup position S1 is inspected.

According to the appearance inspection apparatus of the present invention having the above-described structure, the terminal of the package P (for example, ball pitch, ball diameter, ball position, etc. Ball measurement) and
The mark / package inspection of the package upper surface can be performed in the same tact.

Here, in the appearance inspection apparatus of the present invention,
As an example of the pickup device, as shown in FIG. 1, if the index table 1 in which the package suction pads 1a...
1 pickup position S1 to measurement position S
3 from the measurement position S3 to the non-defective product storage position S5 (or the defective product discharge position S).
7) The package P can be transported simultaneously. Moreover, the pickup operation of the package P at the pickup position S1, the terminal (ball) measurement at the measurement position S3, and the storage operation (or discharge operation) of the package P at the non-defective product storage position S5 (or the defective product discharge position S7) are substantially performed. Since the operations can be performed simultaneously, there is no waste in the operation of the pickup device, and the mark / package void inspection and terminal measurement of the package P can be performed efficiently.

In the appearance inspection apparatus of the present invention, the appearance inspection data by the mark / package void inspection on the upper surface of the package and the inspection data by the image processing measurement (or laser displacement measurement) on the terminal side of the package are transferred to the CRT.
It may be configured to output to a video monitor device such as a printer or a recording device such as a printer to display and record.

Further, in the appearance inspection apparatus of the present invention, when inspecting a package having a ball formed on the back surface as a terminal for electrical connection, a ball image of the package is obtained as shown in FIG. An image is taken by two imaging systems, that is, a two-dimensional imaging system that can take an image in a direction orthogonal to the forming surface and a three-dimensional imaging system that can take an image in an oblique direction to the ball forming surface. Determine the pitch, ball diameter and ball position, and
Ball coplanarity data may be obtained by calculating three-dimensional data based on an output signal of a two-dimensional imaging system and two-dimensional data obtained by the two-dimensional imaging system.

Further, in the appearance inspection apparatus of the present invention,
It is determined whether the package is non-defective based on each output signal of the mark / package void inspection means and the terminal measurement means arranged at the measurement position, and the non-defective / defective product is classified based on the judgment result. You may comprise so that it may be accommodated in a tray.

The mark / package void inspection means and terminal measurement means used in the visual inspection apparatus of the present invention are not particularly limited as long as they can perform mark / package void inspection and ball measurement. In view of the above, it is preferable to use a CCD camera.

[0018]

Embodiments of the present invention will be described below with reference to the drawings.

First, as shown in FIGS. 1 and 2, the appearance inspection apparatus of this embodiment is composed of an index table 1 and X-positioning tables arranged at positions facing each other with the table 1 interposed therebetween.
Y drive mechanisms 2a and 2b are provided.

The index table 1 has a substantially cross shape in plan view, and is provided with suction pads 1a... 1d of the package P at the ends of each side thereof.

The index table 1 is intermittently driven to rotate at a 90 ° pitch (about 1 second per pitch) by a rotating mechanism (not shown), and each of the pads 1a, 1b,
1c, 1d are pickup positions S1,
The measuring position S3, the non-defective product storing position S5, and the defective product discharging position S7 are sequentially arranged. Further, the index table 1 is provided with an elevating mechanism (not shown), and when the pads 1a... 1d are located at the respective positions S1, S3, S5, S7, an elevating movement described later is given. .

The pads 1a,..., 1d of the index table 1 having the above-described structure can individually hold and release (absorb) the upper portion of the package P. The rotation / elevation operation of the index table 1 and the holding / releasing operation of the package P at each of the pads 1a... 1d are performed by an arithmetic processing unit 7 (see FIG. 4) described later.
Is controlled by a control signal from

The XY moving mechanism 2a is a table for individually moving the loader tray T1 in the X-axis and the Y-axis. The XY moving mechanism 2a moves the loader tray T1 in the row direction (X-axis direction) and the column direction in response to a control signal from the arithmetic processing unit 7. Direction (Y-axis direction)
Then, the packages P to be inspected are moved sequentially at the storage pitch of the packages P,.
It is configured to be arranged in.

The XY moving mechanism 2b is a device for individually moving the non-defective tray T2 disposed at a position (at an angle of 180 °) facing the loader tray T1 in the X-axis and the Y-axis, respectively. Similarly, according to the control signal from the arithmetic processing unit 7, the non-defective tray T2 is moved in the row direction (X-axis direction) and the column direction (Y-axis direction) at the storage pitch of the packages PP. The storage locations of the inspected packages P in the non-defective product tray T2 are sequentially arranged in the non-defective product storage position S5.

Below the XY moving mechanism 2a and the XY moving mechanism 2b, a stocker 21a for storing the loader trays T1... T1 and a stocker 21b for storing the non-defective trays T2.

In this embodiment, as shown in FIG. 2, a mark package which can take a plane image (two-dimensional image) of the package P disposed at the pickup position S1 just above the pickup position S1. A void inspection CCD camera 3 (hereinafter referred to as appearance inspection CCD camera 3) and its illumination light source 3a are arranged.

As shown in FIG. 3, the pad 1a, 1b, 1c or 1d of the index table 1 is transported to the measurement position S3.
A two-dimensional measurement CCD camera 4 for capturing a two-dimensional image of the balls B,... B of the package P, the upper part of which is held, and a light source 4a for illumination thereof.

Further, as shown in FIG. 3, a three-dimensional measuring CCD for taking a three-dimensional image of the balls B,... The camera 5 and its illumination light source 5a are arranged.

In this example, the CCD camera 3 for visual inspection, which is arranged just above the pickup position S1, has 400,000 pixels. Also, the measurement position S
Since the two CCD cameras (for ball measurement) arranged in 3 require high resolution, the two-dimensional measurement CCD camera 4
4 million pixels and a 1 million pixel CCD camera 5 for three-dimensional measurement.

The timing of the drive (ON) of each of the three CCD cameras 3, 4, and 5 is controlled by the arithmetic processing unit 7, and the appearance inspection CCD camera 3 controls each of the pads 1a, 1
When b, 1c and 1d reach the point S2, S4, S6 or S8 shown in FIG. 1, that is, the pads 1a, 1b, 1
It is turned ON when c or 1d moves by an angle of 45 ° from the pickup position S1. In addition, C for measurement
The CD cameras 4 and 5 have respective pads 1a, 1b, 1c, 1
When d stops at the measurement position S3 once (about 0.1 to 0.2 seconds), it turns on in synchronization with this. The illumination light sources 3a, 4a, 5a of the CCD cameras 3, 4, 5 are used.
Are also driven (ON) at the same timing as above.

As shown in FIG. 4, the output signals of the appearance inspection CCD camera 3 and the measurement CCD cameras 4 and 5 driven at the above timings are output from the image processing devices 63, 64,
65 sequentially, predetermined signal processing (binary processing etc.)
Is applied to the arithmetic processing unit 7.

The arithmetic processing unit 7 includes, for the image data subjected to image processing by the image processing unit 6,
Based on the image data from the CD camera 3, the presence / absence of a mark, missing characters, presence / absence of a package void, and the like are determined.

Further, based on the image data from the two-dimensional measurement CCD camera 4, the ball pitch, the ball diameter and the ball position are determined, and the image data from the three-dimensional measurement CCD camera 5 and the two-dimensional measurement CCD camera 4
Then, ball coplanarity data is obtained based on the ball plane image data based on the output of (1), and it is determined whether or not the inspection data on those balls is within an allowable range of preset reference data.

Then, the arithmetic processing unit 7 calculates the mark / package void determination result, the ball pitch
If any one of the ball diameter, ball position, and ball coplanarity determination results is unsuccessful, the defective package P is transported to the defective product discharge position S7 without being released at the non-defective product storage position S5, and the NG tray ( (Not shown) is supplied to the index table 1.

In addition to the above operations, the arithmetic processing unit 7 also transmits the presence or absence of package voids and the quality of marks, the ball pitch, the ball diameter, the ball position and the ball coplanarity data to a video monitor device 8 such as a CRT,
(Floppy disk drive) 9 and output to external devices such as a printer 10.

Here, the calculation method for obtaining the ball coplanarity data will not be described in detail in this specification, but the image data from the three-dimensional measurement CCD camera 5 is converted into the ball plane image data and the three-dimensional measurement CCD camera. 5
Can be easily obtained by calibration using the inclination (30 °) with respect to the ball forming surface.

Next, the inspection operation of this embodiment will be described. First, a predetermined number of packages PP are stored (3 rows.times.n columns) in the loader tray T1 with the ball B forming surface facing downward.
Is moved to the pickup position S by the XY moving mechanism 2a.
Positioned relative to 1. In this example, the package P at the upper right corner (see FIG. 1) of the loader tray T1 is located at the pickup position S1 in the initial positioning, and the non-defective tray T2 is correspondingly positioned by the XY moving mechanism 2b. Is located at the non-defective product storage position S5.

In this example, in the initial state, the pad 1a of the index table 1 is located at the defective product discharge position S7, and the index table 1 is in the position shown in FIG. It is arranged at the rising end of the lifting stroke as shown by the solid line.

When the inspection operation is started, first, the index table 1 is rotated.
The index table 1 is at an angle of 45 ° and each pad 1
a, 1b, 1c, 1d are points S8, S2, S4,
At the time of being located at S6, the CCD camera 3 for visual inspection above the pickup position S1 and its illumination light source 3a
Are simultaneously driven, and the image data, that is, the mark / package void inspection data of the package P (first) located at the pickup position S1 is processed by the arithmetic processing unit 7.
It is taken in.

Thereafter, the pads 1a, 1b, 1c, 1d of the index table 1 are moved to the positions S1, S3,
At the time when the index table 1 is located at S5 and S7, the rotation of the index table 1 is stopped, and then the index table 1 is lowered. At the lower end of the index table 1, the first package P in the loader tray T1 is sucked by the pad 1a. The sucked package P is taken out of the loader tray T1 by raising the index table 1.

When the above-described pickup operation of the package P is completed and the index table 1 has risen to the rising end, the index table 1 starts rotating.
Such a pickup operation is completed in about 0.1 to 0.2 seconds.

When the pick-up operation of the package P is completed (or after the operation is completed), the loader tray T1 is moved by one pitch (package storage pitch) in the X-axis direction by the XY drive mechanism 2a. A package P (second) for inspection is placed at the pickup position S1.

Next, in the process of transporting the first package P toward the measurement position S3 by rotating the index table 1, each of the pads 1a, 1b, 1
When c and 1d reach the points S2, S4, S6, and S8, respectively, the second position arranged at the pickup position S1 is reached.
The second image data is collected by the visual inspection CCD camera 3, and the image data is taken into the arithmetic processing unit 7.

Next, when the pads 1a, 1b, 1c, 1d reach the positions S3, S5, S7, S1 respectively by the rotation of the index table 1, the index table 1 stops and descends. At this time, at the pickup position S1, the second package P is taken out by the pad 1b by the same operation as described above. In the measurement position S3, the index table 1
When the camera reaches the lower end, two measurement CCD cameras 4
, 5 and their illuminating light sources 4a and 5a are simultaneously driven, image data of the balls B,... B of the first package P is collected, and this image data is taken into the arithmetic processing unit 7. At the time when such data is collected, the arithmetic processing unit 7 obtains the ball pitch, the ball diameter, the ball position, and the ball coplanarity, and obtains the ball inspection data and the mark, The quality of the first package P is determined using the package void inspection data.

After the ball measurement of the first package P is completed, the index table 1 is lifted, and the second package P at the pickup position S1 is picked up.
When the pickup operation is completed (or after the operation is completed), the loader tray T1 is moved by one pitch (package storage pitch) in the X-axis direction by the XY drive mechanism 2a, and the package P ( Third) is located at the pickup position S1.

When the pick-up operation of the second package P is completed, the index table 1 is rotated. In this rotation process, each of the pads 1a, 1b,
When 1c and 1d reach the points S4, S6, S8 and S2, respectively, the third image data arranged at the pickup position S1 is collected by the visual inspection CCD camera 3, and then the respective pads 1a and 1b , 1c, 1d
Reaches the positions S5, S7, S1, S3, respectively, the following operations are performed at the respective positions S1, S3, S5.

At the pickup position S1, the package P (third) by the pad 1c is operated by the same operation as described above.
) Is taken out. When the pickup operation of the third package P is completed (or after the operation is completed), the fourth package P in two rows is moved by the X-axis and Y-axis movement of the loader tray T1 by the XY drive mechanism 2a. It is located at the pickup position S1.

At the measurement position S3, ball measurement of the second package P by the two measurement CCD cameras 4 and 5 is performed by the same operation as described above.

In the non-defective product storage position P5, if the first package P transported to this position by the pad 1a is a non-defective product, the index table 1
And the first package P is accommodated in the non-defective product tray T2. On the other hand, when the first package P is defective, the state where the package P is sucked by the pad 1a is maintained even when the index table 1 reaches the lower end.

In the non-defective product storage position P5, the first
When the package P is a good product and this package P is stored in the good product tray T2, the loader tray T2
Is moved by one pitch (package storage pitch) in the X-axis direction by the XY drive mechanism 2b, and the place where the next package P is stored is located in the non-defective product storage position S5.

When the operation at each of the positions S1, S3, S5 is completed, the index table 1 rotates,
In this rotation process, after the image data of the fourth package P is collected, each of the pads 1a, 1b, 1c,
1d returns to the initial rotation position (the position shown in FIG. 2). In this state, the fourth package P is picked up (adsorbed by the pad 1d) at the pickup position S1, the ball of the third package P is measured at the measurement position P3, and the non-defective product storage position P5 is measured.
Of the second package P in the non-defective product tray T2 at the same time (in the case of a non-defective product). The package P (first) whose inspection result is defective and not stored in the tray at the non-defective product storage position S5 is discharged to the NG tray at this time.

Thus, one cycle of the operation of the index table 1 has been completed.
The ball measurement, the mark / package void inspection of the fifth and subsequent packages P, and the ball measurement are sequentially performed by the same operation.

As described above, in the embodiment of the present invention, in the process of tray-to-tray (transport from the loader tray T1 to the non-defective tray T2), the package P does not need to be turned over, and the mark void package inspection and Ball measurement can be performed simultaneously.

By the way, in the conventional appearance inspection apparatus, even if the inspection tact is shortened, the upper surface appearance inspection (mark / package void inspection) is limited to about 3 seconds. In the appearance inspection apparatus of the present invention having the configuration shown in FIG. 1, the tact time can be suppressed to 1.2 seconds or less.

In the embodiment of the present invention, the high pixel C
Since a CD camera is used, ball pitch, ball diameter, ball position, and ball coplanarity can be measured with high accuracy.

For example, a two-dimensional measurement CC for ball measurement
When the D camera 4 has 4 million pixels and the three-dimensional measurement CCD camera 5 has 1 million pixels, it is possible to perform ball measurement with high repetition accuracy of ± 5 to 10 μm.

It should be noted that an enormous amount of time is required for image processing of a 4 million pixel super high pixel CCD camera, but by using a large-capacity simultaneous parallel image processing board group, the processing time can be kept within the above-mentioned inspection tact time. It is possible to put.

In the above embodiment, the package P
The three-dimensional measurement CCD camera 5 that captures the ball image of
Since the package P is arranged obliquely with respect to the ball forming surface, distortion (shrinkage) occurs in the obtained image in the direction of camera tilt. Keep going.

As the calibration method, a software method using image processing, or a combination of the optical system of the three-dimensional measurement CCD camera 5 with a perspective correction lens and a cylindrical lens, etc., so that the entire field of view can be obtained even when imaged obliquely. It is also possible to adopt a hardware calibration method such as focusing on the subject.

In the above embodiment, a flat cross index table is used, but the shape of the table is such that it can be picked up by the CCD camera 2 at the pickup position S1 in the process of transporting the package P. Any shape can be adopted as shown in FIG.
As shown in the figure, semicircular notches C
The index table 101 having a shape provided with C may be used.

In the above embodiment, an example is shown in which pads for adsorbing a package are provided at four locations in the index table. However, the number of pads arranged is not particularly limited as long as it is plural. Further, the present invention can be implemented by using another pickup device that can move in the vertical direction with respect to the XY axis, instead of such a rotation type index table.

In the above embodiment, the CCD camera 5 for three-dimensional measurement is arranged at the measurement position S3 in order to measure the ball coplanarity. However, when the ball coplanarity is unnecessary, the ball is placed below the inspection stage. It is sufficient to dispose only the two-dimensional measurement CCD camera 4 that captures a plane image.

In the above embodiment, an example in which the inspection on the terminal side of the package is performed by image processing measurement has been described. However, the present invention is not limited to this, and the laser displacement measurement is used as the inspection on the terminal side of the package. You may.

[0064]

As described above, according to the appearance inspection apparatus of the present invention, terminals such as the ball pitch, the ball diameter, and the ball position can be measured at high speed and with high accuracy.
Also, the inspection of the upper surface mark of the package and the package void can be performed within the same tact. In addition, since these inspections can be performed without reversing the package in the normal orientation, the pickup device does not contact the ball portion of the package from picking up the package to storing it in the shipping tray, and the ball is damaged. There is no fear.

Further, since the tray-to-tray system is used, the inspection apparatus of the present invention can also omit the step of transferring from the manufacturing process tray to the shipping tray, and can be eliminated.

[Brief description of the drawings]

FIG. 1 is a plan view showing a schematic configuration of an embodiment of the present invention.

FIG. 2 is a front view showing a schematic configuration of the embodiment.

FIG. 3 shows a measurement position S in the embodiment of the present invention.
Diagram showing configuration 3

FIG. 4 is a block diagram showing a configuration of a signal processing system according to the embodiment of the present invention.

FIG. 5 is a plan view showing a modification of the index table.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Index table 1a, 1b, 1c, 1d Pad 2a XY moving mechanism (for load tray T1) 2b XY moving mechanism (for good tray T2) 3 CCD camera for mark / package void inspection 3a Light source for illumination 4 CCD for two-dimensional measurement Camera 4a Lighting source for illumination 5 CCD camera for three-dimensional measurement 5a Lighting source for illumination 63, 64, 65 Signal processor 7 Processing unit P Package T1 Load tray T2 Good tray S1 Pickup position S3 Measurement position S5 Good storage position S7 Defective product discharge position

Claims (2)

[Claims] 1. A device for inspecting the appearance of a package such as a BGA / CSP type IC having a mark on an upper surface or the like and a terminal for electrical connection formed on a rear surface, wherein the terminal surface is directed downward. A pickup device that picks up a package stored in a tray in a facing position and conveys it to a measurement position, a mark / package void inspection unit arranged above a pickup position of a package from the tray, and a pickup device that has an upper portion. Measuring means for inspecting the terminal side of the package conveyed to the measurement position while being held by image processing measurement or laser displacement measurement, wherein the package void inspection means is a package which has completed the mark / package void inspection first. While the pickup device is transporting to the measurement position, Located in-up position, the appearance inspection apparatus characterized by being configured to perform the inspection of the next package. 2. In order to speed up the time tact of the whole appearance inspection apparatus, an index table for moving a package in the order of a pickup position of a tray, a measurement position, and another tray is used as the pickup device. The visual inspection device according to claim 1, wherein