JP2001041902A - Foreign matter inspecting apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a foreign matter inspecting apparatus simple in constitution capable of detecting the foreign matter present between a plurality of the lead terminals provided in an IC package with high accuracy. SOLUTION: A foreign matter inspecting apparatus is equipped with a light source 13 for irradiating a plurality of the lead terminals 3 arranged to the side part of an IC package 1 in a protruded state with light, a line sensor 14 having a visual field region of which the width is larger than the length of the lead terminals and counterposed in an optical relation to the terminal row and unidimensionally scanning the light transmitted through the terminal row in the longitudinal direction of the lead terminals to detect the same and a scanning means for displacing the optical opposed position of the line sensor and the terminal row in the arranging direction of the lead terminals to mechanically scan the detection region of the terminal row by the line sensor and the adhesion of foreign matter to the lead elements is judged from the optical data (detection image) obtained through the line sensor and the scanning means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a foreign matter inspection apparatus capable of easily detecting foreign matter adhering between a plurality of lead terminals protruding from a side portion of an IC package or the like.

[0002]

2. Related Background Art Recently, semiconductor integrated circuits (ICs) have been remarkably miniaturized.
P (Qaud Flat Package) and SOP (Small Outline Pac)
In such a case, the arrangement pitch between the plurality of lead terminals tends to be narrower. In addition, printed circuit boards on which this type of IC package is mounted tend to be shipped without cleaning because of consideration for the environment and the like, and are being established as a general mounting process.

[0003] Under such circumstances, if foreign matter adheres between the lead terminals of the above-described IC package, required performance cannot be obtained in an electronic circuit mounted on a printed circuit board, or a short circuit may occur. May be caused. For this reason, the presence or absence of foreign matter attached to the lead terminals is checked in advance to remove foreign matter attached between the lead terminals, or the IC package itself with foreign matter attached to the lead terminals is removed from the object to be mounted on the printed circuit board. Need to be eliminated.

[0004]

Conventionally, the inspection of the adhesion of foreign matter between lead terminals in this type of IC package is performed exclusively by processing the image of the IC package taken using a CCD camera or the like. However, in order to detect fine foreign matter adhering to a plurality of lead terminals arranged at a high pitch with a small gap, a camera with a high resolution (resolution) is required, and an expensive inspection device is required. It cannot be denied.

In the above-described image processing, generally, the entire IC package to be inspected is uniformly illuminated, the entire image is captured, and a lead terminal on the side of the package to be inspected from the input image. Is performed by cutting out the image portion provided. Then, by identifying the image component of the lead terminal from the partial image, the image component other than the lead terminal is regarded as the component of the foreign material adhered to the lead terminal, and the adhesion of the foreign material is detected. Because of this, image processing is complicated and ICs not directly related to inspection
Since it is necessary to take an image of even the main body of the package and process the image, there is a problem that the processing efficiency is very poor.

The present invention has been made in view of such circumstances, and has as its object to simply remove foreign matter adhering between a plurality of lead terminals protrudingly provided on a side portion of an IC package or the like. Another object of the present invention is to provide an inexpensive and highly practical foreign substance inspection device capable of efficiently detecting the foreign matter.

[0007]

In order to achieve the above-mentioned object, a foreign matter inspection apparatus according to the present invention is provided on an arrangement surface of a plurality of lead terminals protruding from a side portion of a package such as a QFP or an SOP. A light source that emits light toward the light source, and a line sensor that has a viewing area having a width greater than the length of the lead terminal in the package and is optically arranged to face the terminal row, and is illuminated by the light source. A line sensor for one-dimensionally scanning and detecting light transmitted through the terminal row in the longitudinal direction of the lead terminal, and displacing an optically opposing position between the line sensor and the terminal row in the arrangement direction of the lead terminals. Scanning means for mechanically scanning a terminal row detection site by the line sensor, and in the image processing means, obtained through the line sensor under the scanning means. It is characterized by determining the adhesion of foreign matters from the academic information (detection image) to between the lead terminals.

That is, according to the present invention, the light transmitted through the arrangement surface of a plurality of lead terminals is obtained by one-dimensional scanning in the longitudinal direction of the lead terminals using a line sensor, and the detection position of the transmitted light by the line sensor is determined. By mechanically scanning in the arrangement direction of the lead terminals, an image composed of the transmitted light component on the arrangement surface of the plurality of lead terminals is easily obtained, and the presence or absence of foreign matter between the lead terminals is efficiently inspected. It is characterized by doing so.

According to a preferred aspect of the present invention, an optical path from the light source to the line sensor is folded back to form an optical path crossing the arrangement surface of the lead terminals via a prism or a reflecting mirror. This makes it easy to optically oppose the arrangement of the lead terminals arranged on the side of the package and the line sensor, and also makes the whole device compact.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A foreign matter inspection apparatus according to one embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing a schematic configuration of a foreign matter inspection apparatus according to this embodiment. Reference numeral 1 denotes an IC package used for inspecting the presence or absence of foreign matter between lead terminals. This IC package 1 has, for example, a QFP (Qaud Flat Packag) having a structure in which a terminal row including a plurality of lead terminals 3 is arranged one-dimensionally on four sides (sides) of a rectangular package body 2.
e) Type SOP (Small Outline Packa)
Of course, it may be of the ge) type.

A foreign matter inspection apparatus for optically inspecting the adhesion of foreign matter to the lead terminals 3 of the IC package 1 is as follows.
For example, a light source 13 that includes a projector 11 and an objective lens 12 incorporated on the upper surface of the device main body 10 and irradiates the terminal array of the IC package 1 with light from above, and a light source 13 provided on the back side of the device main body 10 A line sensor 14 that is optically opposed to the terminal row of the IC package 1 and detects light transmitted through the terminal row. In particular, the line sensor 14 has a linear light receiving surface extending over the entire length of the lead terminal 3, and is optically opposed to the light receiving surface so as to be aligned with the direction in which the lead terminal 3 extends (longitudinal direction). The line sensor 14 is configured to detect the light transmitted through the terminal row including the plurality of lead terminals 3 by one-dimensional scanning over the entire length of the lead terminals 3.

FIG. 2 shows a schematic optical system of an optical path from the light source 13 to the line array 14 for irradiating the terminal array of the IC package 1 and receiving the light transmitted through the terminal array. , Two prisms (reflecting mirrors) which are interposed in the optical path and
It is folded back by 90 ° at intervals of 16. The IC is placed in the optical path region sandwiched between the prisms 15 and 16.
A terminal row provided on one side of the package 1 is selectively interposed, and the presence or absence of foreign matter adhering between these lead terminals 3 is optically inspected.

In particular, the prism 15 is provided so as to reflect light emitted in the horizontal direction from the light source 13 downward and to illuminate the terminal array of the IC package 1 substantially uniformly from above. The prism 16 is provided below the prism 15 with its reflection surface parallel to the direction in which the lead terminals 3 of the IC package 1 are arranged. It is provided so as to reflect toward the apparatus body 10 side. The light reflected by the prism 16 in this manner, that is, the I
The transmitted light of the terminal array in the C package 1 is guided to the light receiving surface of the line sensor 14 via the light receiving lens 17.

The line sensor 14 is provided with the IC that is guided from the prism 16 through the light receiving lens 17 in this manner.
With respect to the transmitted light of the terminal row of the package 1, the longitudinal direction is provided on the rear surface side of the device main body 10 so that the longitudinal direction thereof is vertically aligned so that the linear light receiving surface thereof extends along the longitudinal direction of the lead terminal 3. . The line sensor 14 is a prism 1
The one-dimensional scanning and detection of the transmitted light at the terminal of the IC package 1 guided through the
The information of the transmitted light from the tip to the base is obtained.

Incidentally, the IC package 1 is subjected to an inspection by selectively positioning one of the terminal rows composed of a plurality of lead terminals 3 between the above-described prisms 15 and 16. Then, the IC package 1 is mechanically moved, for example, in the arrangement direction of the lead terminals 3 with respect to the apparatus main body 10, that is, along one side of the IC package 1. As a result of the mechanical movement of the IC package 1, as shown in FIG. Scanning is performed in the arrangement direction of the lead terminals 3 (mechanical scanning means). As a result, in conjunction with the one-dimensional scanning by the line sensor 14, the entire terminal row is subjected to optical inspection for foreign substances. Note that the IC package 1 is fixedly provided, and the inspection area of the terminal row detected by one-dimensional scanning of the line sensor 14 by moving the apparatus main body 10 side in the arrangement direction of the lead terminals 3 is changed to the lead terminal 3. Of course, it is also possible to configure to mechanically scan over the entire width in the arrangement direction.

According to the foreign matter inspection apparatus thus configured, the line sensor 14 is driven to one-dimensionally scan the transmitted light of the terminal row composed of the plurality of lead terminals 3 in the longitudinal direction of each lead terminal 3. By simultaneously moving the IC package 1 (or the apparatus main body 10) in the arrangement direction of the lead terminals 3 while detecting the
For example, it is possible to obtain an image as shown in FIG. That is, IC package 1
Only the image of the terminal row portion provided with the plurality of lead terminals 3 at the end can be obtained as transmitted light information. In addition, if the mechanical scanning speed in the arrangement direction of the terminal rows is made slower than the one-dimensional scanning speed of the line sensor 14, the pitch (scanning interval) of the one-dimensional scanning by the line sensor 14 is sufficiently reduced. Therefore, even if the arrangement pitch of the plurality of lead terminals 3 is narrow, it is possible to obtain transmitted light information with a sufficiently high resolution in the arrangement direction. Therefore, such a detected image is input to an image processing means (not shown) realized by a computer or the like, and the shaded lines arranged in a predetermined direction are drawn to the lead terminals 13.
Of these image components (shaded lines)
Is obtained, it is possible to detect this as a component of a foreign substance attached between the lead terminals 3 or the like with high accuracy.

Further, the image detected by the line sensor 14 in this manner is, for example, when the light emitted from the light source 13 has a certain spread angle, for example, the optical distance L1 from the terminal row to the light receiving lens 17 and the light receiving According to the ratio of the optical distance L2 from the lens 17 to the line sensor 14, the length [L2
/ L1] times. Therefore, even if an inexpensive line sensor 14 incorporated in a facsimile apparatus or the like is used, fine foreign matter adhering between the plurality of lead terminals 3 having a fine arrangement pitch is enlarged in combination with the above-described mechanical scanning. And can be detected with high accuracy. In other words, fine foreign matter adhering between the plurality of lead terminals 3 having a fine arrangement pitch can be reliably detected simply and effectively without using an expensive imaging device such as a CCD camera.

Also, two opposing prisms 15, 16
According to the present apparatus in which the optical path from the light source 13 to the line sensor 14 is folded back using the light source 13, the light source 13 is
0, and a line sensor 14
Can be provided, so that the entire apparatus can be easily made compact. Moreover, by providing the line sensor 14 at the back of the device main body 10, the optical path length from the terminal surface of the IC package 1 to the line sensor 14 can be made sufficiently long, and the light transmitted through the terminal surface as described above. Can be detected in an enlarged manner, and the detection accuracy can be easily improved. Furthermore, since it is only necessary to position the IC package 1 on the side of the apparatus main body 10, it is possible to improve the handling property.

Moreover, according to the present apparatus, the transmitted light in the terminal row where the plurality of lead terminals 3 are arranged on the side of the IC package 1 is partially detected while the line sensor 14 performs one-dimensional scanning. Therefore, the above-described foreign substance inspection processing on the detection information (image) obtained via the line sensor 14 is also easy. In addition, since it is only necessary to detect whether or not the transmitted light is received, the detection process can be easily executed digitally. That is, as shown in FIG. 4, information on a terminal row portion which is detected to be larger than the actual size is obtained as a binary image (digital image) including the presence or absence of transmitted light of the portion, and one-dimensional scanning of the line sensor 14 It is only necessary to focus on a plurality of image components A extending in the direction and lining up in the mechanical scanning direction and to determine the presence of an image component that short-circuits these image components A, so that the image processing is very simple. is there. In addition, since the transmitted light image of the terminal surface is detected by being enlarged as described above, by using appropriate image processing, the foreign matter such as a foreign matter having a risk of short-circuiting or a foreign matter having a possibility of affecting characteristics can be obtained. Can be determined.

In order to obtain the information of the transmitted light of the terminal row as described above, it is only necessary to obtain from the light source 13 the light for illuminating the terminal row composed of the plurality of lead terminals 3 from above. Since there is no need for uniform illumination, the configuration of the light source 13 can be greatly simplified. In particular, the light source 13 only needs to irradiate light having a certain spread angle from above the lead terminals 3, and the objective lens 12 uses the objective lens 12 so as to collectively illuminate the entire terminal row including a plurality of lead terminals 3. Since it is only necessary to set the illumination area, effects such as simplification of the configuration of the entire illumination system can be obtained.

The present invention is not limited to the above embodiment. For example, instead of the light source 13 that uniformly illuminates the entire terminal row, the light emitted from the light source 13 may be slit light having a predetermined width extending in the longitudinal direction of the lead terminal 3. It is also possible to use a known reflecting mirror in place of the prisms 15 and 16, and to arrange the light source 13 directly above the arrangement surface of the lead terminals 3 without using this kind of reflecting mirror, and to provide a line below it. Of course, it is also possible to dispose the sensors 14 facing each other.

Further, the mechanical scanning direction for the terminal row is not limited to the direction orthogonal to the one-dimensional scanning direction by the line sensor 14, but moves across the entire width of the lead terminal 3 intersecting the one-dimensional scanning direction. Any direction is acceptable. However, in this case, regardless of the mechanical scanning in the oblique direction, the width of the light receiving portion of the line sensor 14 is changed so that the entire width from the root portion of the lead terminal 3 to the tip portion thereof can be one-dimensionally scanned. Must be set longer than the length of. Further, since the line sensor 14 having a visual field region having a width larger than the length of the lead terminal is used, foreign matter adhering to the tip of the lead terminal 3 can be easily detected by using appropriate image processing. In addition, the present invention can be variously modified and implemented without departing from the gist thereof.

[0023]

As described above, according to the present invention, the light transmitted through a terminal row composed of a plurality of lead terminals disposed on the side of a package is transmitted to a longitudinal direction of the lead terminal using a line sensor. While detecting by one-dimensional scanning in the direction, the detection site of the transmitted light by the line sensor is mechanically scanned in the arrangement direction of the lead terminals, so that minute foreign matter adhering between the lead terminals with a minute arrangement pitch can be removed. Detection can be performed easily and with high accuracy. In addition, under simple lighting, an inexpensive line sensor can be effectively used to perform a foreign object inspection with high accuracy.

Further, according to the second aspect of the present invention, effects can be obtained such that the device can be made compact and its handling can be improved.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a schematic configuration of a foreign matter inspection apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing a schematic optical system of the foreign matter inspection device shown in FIG. 1;

FIG. 3 is a diagram schematically illustrating the concept of one-dimensional scanning by a line sensor on a terminal row and the mechanical scanning thereof.

FIG. 4 is a view showing an example of a detection image obtained by the foreign substance inspection device shown in FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 IC package 3 Lead terminal 10 Device main body 13 Light source 14 Line sensor 15 Prism (reflection mirror) 16 Prism (reflection mirror) 17 Light receiving lens

Claims (2)

[Claims] 1. A foreign matter inspection device for inspecting the adhesion of a foreign matter to a terminal row composed of a plurality of lead terminals protrudingly arranged on a side portion of a package, comprising: And a light source that irradiates the terminal row with a viewing area having a width larger than the length of the lead terminal and is arranged optically opposite to the terminal row. A line sensor that detects by scanning in a three-dimensional manner; a scanning unit that displaces an optically opposing position between the line sensor and the terminal row in the direction in which the lead terminals are arranged; An image processing means for judging the adhesion of the foreign matter to the terminal row from the obtained optical information. 2. The foreign matter according to claim 1, wherein an optical path from the light source to the line sensor is folded back to form an optical path crossing the arrangement surface of the lead terminals via a prism or a reflecting mirror. Inspection equipment.