KR100796739B1 - Method for inspecting semiconductor - Google Patents

Abstract

A method for testing a semiconductor device is provided to quickly verify defects such as a crack at an edge thereof by inspecting image data of the device in a pixel unit. Image data is obtained from an upper surface of a semiconductor device(S10), and then an outline region is designated on the basis of variations of pixel values of the obtained image data(S20). While the outline region progresses in one direction in the unit of pixel, a vertical variation is measured in which a position of each pixel having a pixel value within a set range is perpendicular to a progress direction(S30). If the vertical variation occurs in a predetermined position, it is determined as a corner of the device, and if the vertical variation is deviated from the predetermined position, it is determined as defective(S40).

Description

Method for inspecting semiconductor

1 is a flowchart illustrating a method of inspecting a semiconductor device according to the present invention.

2 is a plan view illustrating a semiconductor device having cracks at edges thereof.

3A is a conceptual diagram illustrating image data of a cracked semiconductor device in pixel units.

3B is a conceptual diagram illustrating image data of a semiconductor device having burrs in pixel units.

3C is a conceptual diagram illustrating image data of a chipping semiconductor device in pixel units.

***** Explanation of symbols for main parts of drawing *****

1: semiconductor device 2: tray

2a: Marker

The present invention relates to a method for inspecting a semiconductor device, and more particularly, to a method for inspecting a semiconductor device for inspecting a semiconductor device for inspecting a top surface of the semiconductor device for cracks or the like.

After the packaging process, the semiconductor device is shipped to the customer tray after inspection of DC test and burn-in test. The semiconductor device to be shipped is subjected to a marking process in which a label such as a serial number and a manufacturer's logo is displayed on the surface of the semiconductor device by a laser.

In addition, the semiconductor device finally inspects the appearance of the semiconductor device, such as whether the lead or the ball grid is broken, cracks, or scratches, and whether the marking formed on the surface is good. It goes through the process.

On the other hand, as the inspection time of the appearance state of the semiconductor device and whether or not the marking is good is relatively added, the inspection time affects the time for performing the entire process.

In particular, when the inspection process of the appearance and marking of the semiconductor device is performed inefficiently, there is a problem in that the productivity is reduced by being accumulated in the inspection process and lowering the overall working efficiency.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for inspecting a semiconductor device capable of quickly inspecting whether a semiconductor device is good, such as occurrence of cracks in an outline part, by inspecting image data of a semiconductor device in pixel units in order to solve the above problems. There is.

The present invention was created to achieve the object of the present invention as described above, the present invention comprises the image acquisition step of acquiring the image data for the upper side of the semiconductor device; An outline region designation step of designating an outline region based on a change in pixel value in the image data obtained in the image acquisition step; A vertical change amount measuring step of measuring a vertical change amount of each pixel having a pixel value within a set range while moving the outline region in one direction on the basis of a pixel unit and perpendicular to a moving direction; And a change amount determining step of determining that the vertical change amount is at an edge of the semiconductor device when the vertical change amount occurs at a predetermined position, and determining that the vertical change amount is a defect when the vertical change amount deviates from a predetermined position. do.

In the change amount determining step, it is determined that there is a burr when the vertical change amount deviates outward from the outline region, and when the vertical change amount deviates inward from the outline region, it is determined that there is a crack, and the vertical change amount If generated at the edge of the semiconductor device can be determined as chipping (chipping).

The change amount determining step may determine that there is a vertical change amount when the vertical change amount continuously changes above a preset value.

In the image acquisition step, an edge may be displayed in the outline region designation step to obtain image data on an upper side of the semiconductor device, and the edge displayed in the image data in the outline region designation step may be recognized as an edge of the semiconductor device. .

The present invention also discloses a semiconductor device inspection apparatus which performs the above-described method for inspecting a semiconductor device.

Hereinafter, a method of inspecting a semiconductor device according to the present invention will be described in detail with reference to the accompanying drawings.

In the method for inspecting a semiconductor device according to the present invention, a semiconductor device for inspecting whether a crack is generated by analyzing an image obtained by acquiring image data of the semiconductor device 1 by an apparatus for image acquisition such as a scanner or a camera Used for inspection equipment.

The semiconductor device inspection apparatus includes an image acquisition device for acquiring an image of a tray 2 on which one or more semiconductor devices 1 for inspection are mounted, and a semiconductor device 1 seated on the tray 2. City).

Marker 2a may be formed on the tray 1 to recognize edges of the image data of the semiconductor device 1.

As shown in FIG. 1, the method for inspecting a semiconductor device according to the present invention includes an image acquisition step S10, an outline region designation step S20, a vertical change amount measurement step S30, and a change amount determination step S40. It is composed.

In the image acquisition step S10, an image of the semiconductor device 1 to be inspected, in particular, image data of an upper side is obtained by an image acquisition device such as a camera. In this case, a high magnification lens or the like may be used as the image acquisition device to increase the resolution.

The image data of the semiconductor device 1 is as shown in FIG. 2, and is preferably composed of monochrome such as black and white in consideration of the fact that the inspection item is a crack or the like, and has a constant resolution (1024 × 768) while being 0 ~. It consists of pixels with 255 values.

When image data is acquired in the image acquisition step S10, an outline region specifying step S20 and a vertical change amount measuring step S30 are performed as a procedure for analyzing the acquired image. At this time, in the image acquisition step (S10), it is possible to rotate the rotated image, or to correct the image data such as brightness adjustment.

The outline region specifying step (S20) is a step of specifying an outline region in advance in order to measure a vertical change amount h, which is a position change amount in a vertical direction of a pixel, and designating the outline region based on a change in pixel value in the acquired image data. .

For example, in the outline region, as shown in FIG. 2, it can be seen that the pixel value suddenly changes from a low value to a high value or from a high value to a low value. The range value is specified as the outline area.

Meanwhile, when the mark 2a is formed on the tray 2 in the image acquisition step, the mark 2a may be recognized as an edge in the image data of the semiconductor device 1 based on the mark 2a in the outline region step S20.

When the outline region is designated by the outline region step (S20), the position of each pixel having a pixel value within the set range while the outline region is advanced in one direction based on the pixel unit is a vertical change amount which is a position change amount in a direction perpendicular to the progress direction. (h) to perform the vertical change amount measuring step (S30).

That is, as shown in FIGS. 3A to 3B, the image data has pixel values distributed in the horizontal direction (X direction) and the vertical direction (Y direction), and in one direction (X direction or Y direction) in the portion corresponding to the outline region. Direction, the position (X value and Y value) of the pixel having a pixel value within a preset range along the outline area is measured.

In FIGS. 3A to 3B, pixels having pixel values within a preset range are pixels of shaded portions, and in the case of cracks, as shown in FIG. 3A, distribution of pixels having pixel values within a preset range is outlined. In the case of burrs distributed into the area or partially protruding outwardly, as shown in FIG. 3B, in the case of chipping such as in the case of being distributed out of the outline area or cut off of the edges, it is shown in FIG. 3C. As can be seen, some incline at the corners.

That is, as shown in FIGS. 3A to 3B, when there is a crack, burr, or chipping, the image data is moved in the direction perpendicular to the traveling direction (X direction or Y direction) in the outline area (Y direction or X direction). The position changes continuously, and the change amount of the position is measured as the vertical change amount h.

In more detail, the image data of the semiconductor device 1 compares the pixel values of adjacent pixel values along the advancing direction sequentially in each pixel value in the outline region.

In this case, since the vertical change amount h is negligible in the case of one or two pixels, it is necessary to set the lower limit value n of the vertical change amount h in advance. It may be determined that there is a vertical change amount h only when the vertical change amount is more than the lower limit n.

When the vertical change amount h is measured as described above, the change amount determination step S40 of determining whether the semiconductor device 1 is defective is performed according to the vertical change amount h.

That is, when the vertical change amount h occurs at a predetermined position, it is determined as a corner of the semiconductor device 1, and when the vertical change amount h is out of a predetermined position, it is determined as bad.

In this case, as shown in FIG. 3B, when the vertical change amount h moves outward from the outline area, it is determined that there is a burr, and the vertical change amount h is shown in FIG. 3A. In the case of moving away from the inside, it may be determined that there is a crack, and when the vertical change amount h is generated at the edge of the semiconductor device 1, it may be determined as chipping.

After the change amount determination step as described above is performed, the determination result is stored by a control unit (not shown) corresponding to each semiconductor device 1 to be inspected and classified by a sorting module according to the determination result.

The method for inspecting a semiconductor device according to the present invention has an advantage in that it is possible to quickly inspect whether a semiconductor device is good, such as crack generation in an outline part, by inspecting image data of a semiconductor device in pixel units.

In addition, the inspection method of the semiconductor device according to the present invention has the advantage that can be confirmed whether the occurrence of cracks, burrs, chipping, etc. by one outline inspection can improve the inspection speed.

Although the preferred embodiments of the present invention have been described above by way of example, the scope of the present invention is not limited to these specific embodiments, and may be appropriately changed within the scope described in the claims.

Claims (5)

An image acquiring step of acquiring image data of an upper surface of the semiconductor device; An outline region designation step of designating an outline region based on a change in pixel value in the image data obtained in the image acquisition step; A vertical change amount measuring step of measuring a vertical change amount of each pixel having a pixel value within a set range while moving the outline region in one direction on the basis of a pixel unit and perpendicular to a moving direction; And a change amount determining step of determining that the vertical change amount is at an edge of the semiconductor device when the vertical change amount occurs at a predetermined position, and determining that the vertical change amount is a defect when the vertical change amount deviates from a predetermined position. The method of claim 1, In the change determination step, When the amount of vertical change deviates outward from the outline area, it is determined that there is a burr, If the amount of vertical change deviates inward from the outline area, it is determined that there is a crack, And if the vertical change amount is generated at the edge of the semiconductor device, determining as chipping. The method of claim 1, The change amount determination step And determining that there is a vertical change amount when the vertical change amount continuously changes above a preset value. The method of claim 1, In the image acquisition step In the outline region designation step, corners are displayed to acquire image data of the upper surface of the semiconductor device. And identifying an edge displayed in the image data as an edge of the semiconductor device in the outline region designation step. A device for inspecting a semiconductor device which performs the method for inspecting the semiconductor device according to claim 1.

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