JP2005045194A - Probe-mark reader and probe-mark reading method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a probe-mark reader reading a probe mark for a short time without causing trouble to users, and a probe-mark reading method. <P>SOLUTION: This probe-mark reader is a device reading the probe mark that is formed on the electrode pad of a semiconductor chip that is included in a semiconductor wafer 90. There are provided a CCD camera 20 imaging this semiconductor wafer 90 to output it as a picture signal Si, an optical part 21 magnifying an object point to be imaged by this CCD camera 20 optically, a light source 30 illuminating the object point to be imaged by the CCD camera 20 by the flash generated for only a short time from the point when a flash signal Sf is given, an XY stage 40 changing the position to be imaged by the CCD camera 20 by mounting the semiconductor wafer 90 movably to the X direction and the Y direction on the basis of a motor control signal Sm, and a computer 10 controlling these and receiving the picture signal Si to store the image after a trimming process. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a needle mark reading device and a needle mark reading method for reading a needle mark formed on an electrode pad by an electrical characteristic inspection of a predetermined object to be inspected (for example, a semiconductor chip).

  In order to inspect the electrical characteristics of a semiconductor chip formed on a semiconductor wafer, a needle-like inspection probe is usually pressed against an electrode pad in the semiconductor chip. Here, since the electrode pad is typically made of aluminum, the electrode pad is covered with an insulating aluminum oxide film formed by being oxidized at the time of inspection. Therefore, the inspection probe is pressed against the electrode pad with a certain force so as to break through the coating. As a result, a needle mark (contact mark) is formed on the electrode pad by the inspection probe. By reading the state of the needle mark such as the presence / absence, position, and depth of the needle mark, it is determined whether or not the inspection probe is correctly pressed against the electrode pad.

  Conventional needle mark reading devices for reading the state of the needle mark include those for observing the state of the needle mark with a microscope, those for photographing the needle mark in a photograph, and those for picking up the needle mark with a CCD camera. In JP-A-5-3230, a semiconductor wafer on which a semiconductor chip is formed is placed on a stage, and an image obtained by photographing a needle mark formed on an electrode pad with a CCD camera is stored and appropriately stored. Is disclosed. With this configuration, it is possible to check the change over time of the needle mark and manage the change over time such as the needle pressure of the inspection probe and the needle displacement.

In addition, a device that detects an object different from the electrode pad, for example, a tape inspection device that reads a repeated pattern (see, for example, Patent Document 2), or a mark position detection device that detects an alignment mark on a wafer (for example, Patent Document 2). And a material surface inspection apparatus (see, for example, Patent Document 3) for inspecting foreign matters and scratches on the wafer surface by synchronizing the flash emission with the position of the target object while moving the target object. There is a configuration in which an object is continuously photographed.
JP-A-5-3230 JP-A-9-222231 JP-A-10-281729 JP 11-326233 A

  However, in the conventional needle mark reading device (see, for example, Patent Document 1), since the needle mark formed on the electrode pad is directly observed or photographed, the semiconductor wafer placed on the stage or the like is selected by the user. Positioning is performed by being moved. For this reason, in many cases, it takes much time and time to read one by one the needle marks that are tens of thousands to hundreds of thousands on the entire wafer.

  In addition, there are devices that detect an object different from the electrode pad and continuously shoot while moving the object as described above (see, for example, Patent Documents 2 to 4). According to this, it is possible to take an image for a short time without taking time and effort for the user. However, these devices repeat imaging at the same cycle, and imaging is performed at high speed by keeping the imaging interval constant. Therefore, it is not planned to image at high speed an object that is not necessarily arranged at regular intervals, such as an electrode pad, and whose arrangement position may change (depending on the wafer). Therefore, it is not easy to use the above apparatus for an apparatus that reads a large number of needle marks formed on a large number of electrode pads.

  Furthermore, in recent years, inspections are often performed a plurality of times as the number of electrical test items for a chip increases and the test contents become complicated. In that case, the inspection is often performed while shifting the position of the inspection probe little by little so that the electrode pad having a thickness of about 1 micron does not have a hole. A plurality of needle marks are formed on the electrode pad that has undergone such multiple inspections. Therefore, it is difficult to determine which of the plurality of needle marks is the needle mark formed by the final inspection. Here, for example, by calculating the difference between the last pre-inspection image and the post-inspection image in pixel units, it is possible to determine the position or the like of the needle mark from the captured image of the electrode pad. However, such a difference calculation takes a very long time.

  Therefore, an object of the present invention is to provide a needle mark reading device and a needle mark reading method, and a needle mark inspection device and a needle mark inspection method for reading a needle mark in a short time without trouble for the user. is there.

  A further object of the present invention is to provide a needle mark reading device and a needle mark reading method that determine the position and the like of a needle mark at high speed from an image obtained by photographing an electrode pad.

A first invention is a needle mark reading device for reading a needle mark formed on the electrode pad when inspecting an electrical characteristic of a predetermined object including a plurality of electrode pads,
Illumination means for illuminating the electrode pad;
Imaging means for imaging the electrode pad illuminated by the illumination means, and outputting an image obtained by imaging as an electrical signal;
Imaging position changing means for continuously changing the imaging position to be imaged by the imaging means;
Storage means for receiving the electrical signal from the imaging means and storing the image obtained from the electrical signal;
An image of the electrode pad to be imaged is given to the imaging unit for a predetermined time in the vicinity of the time point at which the electrode pad is to be imaged by the imaging unit.

According to a second invention, in the first invention,
The imaging position changing means can sequentially take images of all the electrode pads with a time interval equal to or longer than the imaging time for acquiring one image in the case where images are continuously taken by the imaging means. The imaging position is changed at a predetermined moving speed.

According to a third invention, in the first invention,
The illumination means is a flash means that emits flash light, and the flash light is emitted for a predetermined time in the vicinity of a time point when the electrode pad is to be imaged by the imaging means, whereby the imaging means should be imaged. An image of the electrode pad is provided.

According to a fourth invention, in the first invention,
Storage means for storing arrangement information which is data relating to the arrangement positions of the plurality of electrode pads;
Based on the arrangement information stored in the storage means, the position where the electrode pad is to be imaged is calculated by the imaging means, and the imaging position matches the position where the electrode pad is to be imaged by the imaging position changing means. And trigger means for causing the image pickup means to pick up an image at the time of the above.

According to a fifth invention, in the first invention,
Based on the image stored in the storage means, further comprising needle mark inspection means for determining the quality of a predetermined needle mark included in the image,
The needle mark inspection means
Corresponds to a vector from the position of the needle mark as a model registered in advance in relation to a predetermined electrode pad selected from the plurality of electrode pads to the position of the needle mark formed on the predetermined electrode pad An initial vector calculating means for calculating an initial vector;
The different electrode pad within a predetermined determination range including a position separated from the position of the needle mark which is a model registered in advance in relation to an electrode pad different from the predetermined electrode pad by the direction and distance of the initial vector. And needle mark quality determining means for determining whether or not a needle mark to be formed is detected.

According to a sixth invention, in the fifth invention,
The needle mark inspection means determines whether or not the needle mark overlaps a predetermined area set in the vicinity of the periphery of the electrode pad including the needle mark detected by the needle mark quality determination means. Further comprising means.

According to a seventh invention, in the fifth invention,
The needle mark inspection unit generates classification header information including information for identifying each electrode pad included in the object to be inspected and a determination result of the needle mark pass / fail determination unit, and associates it with an image of the corresponding electrode pad. It further comprises a classification header creating means for storing the classification header information in the storage means.

In an eighth aspect based on the fifth aspect,
The initial vector calculation means includes
By calculating the difference of the image of the predetermined electrode pad that is captured in advance before the inspection of the electrical characteristics from the image stored in the storage means, the needle marks formed by the inspection of the electrical characteristics are obtained. Detecting means for detecting;
Calculation means for calculating an initial vector corresponding to a vector from the position of the needle mark as a model registered in advance in relation to the predetermined electrode pad to the position of the needle mark detected by the detection means. It is characterized by.

According to a ninth invention, in the fifth invention,
The initial vector calculating means is formed on each electrode pad from the position of a needle mark that is a model registered in advance in association with each electrode pad of the four electrode pads located near the corner of the object to be inspected. Calculate the initial vector based on the vector up to the position of the needle mark to be performed,
The needle mark pass / fail determination means includes a predetermined determination including a position that is separated from the position of the initial vector by a direction and a distance from a position of a needle mark that is a model registered in advance in association with an electrode pad different from the four electrode pads. It is determined whether or not a needle mark to be formed on the electrode pad is detected within the range.

A tenth aspect of the invention is a needle mark inspection apparatus for inspecting a needle mark formed on the electrode pad when inspecting an electrical characteristic of a predetermined object to be inspected including a plurality of electrode pads.
Needle marks included in an image of the electrode pad obtained by imaging the electrode pad from a position of a needle mark that is a model registered in advance in association with a predetermined electrode pad selected from the plurality of electrode pads Initial vector calculation means for calculating an initial vector corresponding to the vector up to the position of
The different electrode pad within a predetermined determination range including a position separated from the position of the needle mark which is a model registered in advance in relation to an electrode pad different from the predetermined electrode pad by the direction and distance of the initial vector. It is characterized by comprising needle mark quality determination means for determining whether or not a needle mark to be formed is detected.

An eleventh aspect of the invention is a needle mark reading method for reading a needle mark formed on the electrode pad when inspecting electrical characteristics of a predetermined object to be inspected including a plurality of electrode pads.
An illumination step of illuminating the electrode pad;
An imaging step of imaging the electrode pad illuminated in the illumination step and outputting an image obtained by imaging as an electrical signal;
An imaging position changing step for continuously changing the imaging position to be imaged in the imaging step;
Receiving the electrical signal output in the imaging step, and storing the image obtained from the electrical signal,
An image of the electrode pad to be imaged in the imaging step is provided for a predetermined time in the vicinity of the time point at which the electrode pad is to be imaged in the imaging step.

In a twelfth aspect based on the eleventh aspect,
In the imaging position changing step, the images of all the electrode pads can be sequentially taken with a time interval equal to or longer than the imaging time for acquiring one image in the case of imaging continuously in the imaging step. The imaging position is changed at a predetermined moving speed.

In a thirteenth aspect based on the eleventh aspect,
In the illumination step, an image of the electrode pad to be imaged in the imaging step is provided by emitting a flash for a predetermined time in the vicinity of a time point at which the electrode pad is to be imaged in the imaging step. .

In a fourteenth aspect based on the eleventh aspect,
Based on the image stored in the storage step, further includes a needle mark inspection step of determining the quality of a predetermined needle mark included in the image,
The needle mark inspection step includes
Corresponds to a vector from the position of the needle mark as a model registered in advance in relation to a predetermined electrode pad selected from the plurality of electrode pads to the position of the needle mark formed on the predetermined electrode pad An initial vector calculating step for calculating an initial vector;
The different electrode pad within a predetermined determination range including a position separated from the position of the needle mark which is a model registered in advance in relation to an electrode pad different from the predetermined electrode pad by the direction and distance of the initial vector. A needle mark quality determining step for determining whether or not a needle mark to be formed is detected.

A fifteenth aspect of the invention is a needle mark inspection method for inspecting a needle mark formed on the electrode pad when inspecting electrical characteristics of a predetermined object to be inspected including a plurality of electrode pads.
Needle marks included in an image of the electrode pad obtained by imaging the electrode pad from a position of a needle mark that is a model registered in advance in association with a predetermined electrode pad selected from the plurality of electrode pads An initial vector calculating step for calculating an initial vector corresponding to the vector up to the position of
The different electrode pad within a predetermined determination range including a position separated from the position of the needle mark which is a model registered in advance in relation to an electrode pad different from the predetermined electrode pad by the direction and distance of the initial vector. A needle mark quality determining step for determining whether or not a needle mark to be formed is detected.

In a fifteenth aspect based on the fifteenth aspect,
It further includes a needle mark position determination step for determining whether or not the needle mark overlaps a predetermined region set in the vicinity of the periphery of the electrode pad including the needle mark detected by the needle mark quality determination step. And

In a fifteenth aspect based on the fifteenth aspect,
Classification header information including information for identifying each electrode pad included in the object to be inspected and a determination result in the needle mark pass / fail determination step is generated, and the classification header information is associated with an image of the corresponding electrode pad and the predetermined classification header information The method further includes a step of creating a classification header stored in the storage unit.

In an eighteenth aspect based on the fifteenth aspect,
The initial vector calculating step includes:
A detection step of detecting a needle mark formed by the inspection of the electrical characteristics by calculating a difference from the image of the predetermined electrode pad imaged in advance before the inspection of the electrical characteristics from the image;
A calculation step of calculating an initial vector corresponding to a vector from the position of the needle mark as a model registered in advance with respect to the predetermined electrode pad to the position of the needle mark detected in the detection step. It is characterized by.

In a nineteenth aspect based on the fifteenth aspect,
In the initial vector calculating step, a pattern is formed on each electrode pad from a position of a needle mark that is a model registered in advance in association with each electrode pad of the four electrode pads positioned in the vicinity of the corner of the object to be inspected. Calculate the initial vector based on the vector up to the position of the needle mark to be performed,
In the needle mark pass / fail determination step, a predetermined determination including a position separated by a direction and a distance of the initial vector from a position of a needle mark that is a model registered in advance in association with an electrode pad different from the four electrode pads. It is determined whether or not a needle mark to be formed on the electrode pad is detected within the range.

Furthermore, as a means to solve the problem,
A needle mark inspection device for inspecting a needle mark formed on the electrode pad when inspecting electrical characteristics of a predetermined object to be inspected including a plurality of electrode pads,
Needle marks included in an image of the electrode pad obtained by imaging the electrode pad from a position of a needle mark that is a model registered in advance in association with a predetermined electrode pad selected from the plurality of electrode pads Initial vector calculation means for calculating an initial vector corresponding to the vector up to the position of
The different electrode pad within a predetermined determination range including a position separated from the position of the needle mark which is a model registered in advance in relation to an electrode pad different from the predetermined electrode pad by the direction and distance of the initial vector. In addition to the needle mark quality determination means for determining whether or not a needle mark to be formed is detected, a needle mark inspection apparatus having the following first to fourth configurations having the following technical features is also considered. It is done.

  The first configuration is a needle mark position determination unit that determines whether or not the needle mark overlaps a predetermined region set in the vicinity of the periphery of the electrode pad including the needle mark detected by the needle mark quality determination unit. Is further included.

  The second configuration generates classification header information including information for identifying each electrode pad included in the object to be inspected and a determination result of the needle mark quality determination unit, and associates the image with the corresponding electrode pad image. The apparatus further includes a classification header creating unit that stores the classification header information in the storage unit.

In a third configuration, the initial vector calculation means includes:
By calculating the difference of the image of the predetermined electrode pad that is captured in advance before the inspection of the electrical characteristics from the image stored in the storage means, the needle marks formed by the inspection of the electrical characteristics are obtained. Detecting means for detecting;
Calculation means for calculating an initial vector corresponding to a vector from the position of the needle mark as a model registered in advance in relation to the predetermined electrode pad to the position of the needle mark detected by the detection means. It is characterized by.

According to a fourth configuration, the initial vector calculating means is configured to calculate the initial vector from a position of a needle mark that is a model registered in advance in association with each electrode pad of the four electrode pads located in the vicinity of the corner of the object to be inspected. Calculate the initial vector based on the vector up to the position of the needle mark formed on each electrode pad,
The needle mark pass / fail determination means includes a predetermined determination including a position that is separated from the position of the initial vector by a direction and a distance from a position of a needle mark that is a model registered in advance in association with an electrode pad different from the four electrode pads. It is determined whether or not a needle mark to be formed on the electrode pad is detected within the range.

  According to the first aspect, the imaging position is continuously changed by the imaging position changing means, and the image of the electrode pad to be imaged is given to the imaging means for a short time near the imaging time point. The image of the electrode pad is obtained. With this configuration, an image of the electrode pad can be acquired and the needle mark can be read in a short time without any effort for the user.

  According to the second aspect of the invention, the image pickup position changing means sequentially picks up images at a predetermined speed with a time interval longer than the shooting time. With this configuration, the imaging position can be moved at high speed. In addition, when the moving speed is constant, the imaging condition at each imaging position can be made constant.

  According to the third aspect of the invention, the electrode pads that are illuminated for a short time by the flash of the illumination means are sequentially imaged by the imaging means. With this configuration, image blurring can be prevented, and an image can be acquired with a device configuration that is easier and less expensive than a physical shutter device or the like.

  According to the fourth aspect of the invention, since the imaging positions of all the electrode pads to be imaged are calculated based on the arrangement information by the trigger means, they are not necessarily arranged at equal intervals and are arranged by the semiconductor wafer. It is possible to read a large number of needle marks formed on a large number of electrode pads that may change at high speed.

  According to the fifth invention, an initial vector is calculated from a predetermined electrode pad selected from a plurality of electrode pads, and in needle mark inspection of other electrode pads, the needle is based on the initial vector and a predetermined determination range. Judge the quality of the mark. Thereby, even if a plurality of needle marks are included in an image obtained by photographing the electrode pad, it is possible to determine at high speed whether or not the needle marks formed by the final electrical characteristic inspection are good.

  Further, when detecting the needle mark formed by the final electrical characteristic inspection by the difference calculation in pixel units, there is a possibility that misdetection due to deviation at the time of image acquisition may occur. Since the relative position detection based on is performed, the needle mark inspection can be accurately performed without being affected by a shift at the time of image acquisition or a change in brightness of pixels.

  According to the sixth aspect, since it is determined whether or not the region occupied by the needle mark overlaps the region of the protection portion (passivation portion) that is normally formed near the periphery of the electrode pad, these regions overlap. In this case, it is possible to determine by the needle mark position determining means that there is a possibility that a problem such as poor conduction in the electrical characteristic inspection may occur.

  According to the seventh aspect, the created classification header information can efficiently specify and take out from the storage means an image of the electrode pad to be inspected at the time of a detailed inspection to be performed later. .

  According to the eighth aspect of the invention, time-consuming image difference calculation is performed only when the initial vector is calculated, and in other needle mark inspections, the quality of the needle mark is determined based on the initial vector and a predetermined determination range. . Thereby, even if a plurality of needle marks are included in an image obtained by photographing the electrode pad, it is possible to determine at high speed whether or not the needle marks formed by the final electrical characteristic inspection are good.

  According to the ninth aspect of the invention, the initial vector is calculated by paying attention to the four electrode pads located near the corner of the device under test (for example, a semiconductor chip). Slight deviations in the X, Y or rotation directions that occur can be averaged sufficiently accurately, and the initial vector is calculated with a small number of electrode pads, so that the quality of the needle marks can be determined at high speed.

  According to the tenth aspect of the invention, unlike the fifth aspect of the invention, the imaging means is not premised. However, as with the fifth aspect of the invention, a plurality of needle marks are included in the image of the electrode pad photographed in advance. Even if it is a case, the quality etc. of the needle mark formed by the last electrical characteristic test | inspection can be determined at high speed. Further, when detecting the needle mark formed by the final electrical characteristic inspection by the difference calculation in pixel units, there is a possibility that misdetection due to deviation at the time of image acquisition may occur. Since the relative position detection based on is performed, the needle mark inspection can be accurately performed without being affected by a shift at the time of image acquisition or a change in brightness of pixels.

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.
<1. Overall configuration>
FIG. 1 is a block diagram showing a configuration of a needle mark reading device according to an embodiment of the present invention. This needle mark reading device is a device that reads the needle marks formed on the electrode pads of the semiconductor chip included in the semiconductor wafer 90, and the CCD camera 20 that images the semiconductor wafer 90, and the CCD camera 20 images. The optical unit 21 that optically enlarges the image of the target location to be imaged, the light source 30 that illuminates the target location to be imaged by the CCD camera 20, and the mounting table on which the semiconductor wafer 90 is mounted are arranged in the X direction. And an XY stage 40 that changes the position to be imaged by the CCD camera 20 by moving in the Y direction, and a computer 10 that controls these. Here, it is assumed that no light source other than the light source 30 exists.

  The CCD camera 20 is fixed at a predetermined position above the XY stage 40 on which the semiconductor wafer 90 is placed, and a plurality of images of a predetermined portion of the semiconductor wafer 90 enlarged by the optical unit 21, that is, a plurality of CCD cameras 20 are formed in the semiconductor wafer 90. A vicinity of a predetermined electrode pad included in the semiconductor chip is captured as a two-dimensional image based on a trigger signal St from the computer 10, and the two-dimensional image obtained by the imaging is output as an image signal Si. Specifically, the CCD camera 20 is configured such that when a trigger signal St is given, a shutter built in the CCD camera 20 is opened, and after a flash is emitted by a light source 30 described later, the shutter is closed. Take an image. The CCD camera 20 is an imaging device that uses a black and white or color charge coupled device (CCD) as an image sensor. Instead, an imaging device that uses a metal oxide semiconductor (MOS) or other photoelectric device. An imaging device having a conversion function may be used.

  The optical unit 21 causes the CCD camera 20 to form an optically magnified image (about 10 to 20 times here) of a predetermined portion of the semiconductor wafer 90 by one or more built-in lenses. The optical unit 21 may be omitted when the resolution of the CCD camera 20 is sufficiently high.

  The light source 30 is a xenon flash lamp that is fixed at a predetermined position above the semiconductor wafer 90 and illuminates a predetermined portion to be imaged by the CCD camera 20. The light source 30 illuminates the predetermined portion by emitting a high-intensity flash for a short time of about several microseconds from the time when the flash signal Sf output immediately after the trigger signal St is output from the computer 10 is given. To do. The time illuminated by this flash is very short compared to the shutter speed (several milliseconds) of a normal camera, but this prevents blurring of an image obtained by imaging caused by movement of the semiconductor wafer 90 as a subject. Because. The reason for illuminating with the high-intensity light source 30 is to obtain a sufficient amount of light necessary for imaging by the CCD camera 20 in a short time. Therefore, since this light source 30 should just be a light source which can emit high-intensity light only for a short time, it may be LED or a laser light source, for example. Here, since the time from the output of the trigger signal St to the output of the flash signal Sf is negligibly short, it is assumed that these signals are output almost simultaneously in the following. Further, the flash signal Sf is specifically generated by inputting the trigger signal St to a delay circuit having a very short delay time.

  The XY stage 40 has a semiconductor wafer 90 mounted on a movable mounting table provided on the upper surface side thereof, and a motor (for example, a stepping motor, a servo motor) for moving the mounting table in the X direction and the Y direction. And a linear motor or the like) and an encoder (for example, various motor encoders or a linear scale) for determining the movement distance of the mounting table in the X direction and the Y direction. The motor included in the XY stage 40 is controlled based on a motor control signal Sm from the computer 10 and drives the above mounting table to move to a predetermined position. The encoder included in the XY stage 40 is an X-Encoder Pulse (hereinafter abbreviated as “X pulse signal”) which is a pulse signal generated each time the mounting table moves by a unit distance in the X direction. Y-Up Pulse (hereinafter referred to as “Y pulse signal”), which is a pulse signal generated every time the mounting table moves by a unit distance in the Y direction, and X, where the mounting table is a reference position in the X direction. X-Reset (hereinafter referred to as “X reset signal”) that is a signal that is generated when positioned on the axis, and a signal that is generated when the mounting table is positioned on the Y axis that is the reference position in the Y direction Encoder signal Se including Y-Reset (hereinafter referred to as “Y reset signal”).

  This needle mark reading device moves the semiconductor wafer 90 mounted on the mounting table by the XY stage 40 at a constant speed in the X direction, and sets the electrode pad illuminated at a predetermined timing by the flash of the light source 30 to the CCD. Images are taken sequentially by the camera 20. Further, every time the imaging operation in the X direction is completed, the semiconductor wafer 90 is moved by a predetermined distance (that is, one line) in the Y direction, and the imaging operation in the X direction is repeated, thereby being included in the semiconductor chip of the semiconductor wafer 90. Image all electrode pads. FIG. 2 is a diagram for explaining such an imaging operation.

  2 is a schematic diagram showing a positional relationship between the XY stage 40 (mounting table) and the semiconductor wafer 90. The XY coordinate system and its origin are shown in the upper left part of the figure, but these are the XY coordinate system of the XY stage 40 and its origin. Further, the XY coordinate system is the same as the coordinate system of the image obtained by imaging with the CCD camera 20, and the origin position is the same as the center position of the image obtained by imaging (hereinafter referred to as "imaging position"). Thus, the position of the CCD camera 20 is set with respect to the XY stage 40.

  The diagram shown in the lower half of FIG. 2 is a diagram showing the locus of the imaging position when the CCD camera 20 images the electrode pad 92 in the semiconductor chip 91 included in the semiconductor wafer 90. P1 in the figure indicates the imaging position (hereinafter referred to as “start position”) when the imaging operation is started, and P2 in the figure indicates the imaging position (hereinafter referred to as “end position”) when the imaging operation is ended. ). The CCD camera 20 sequentially images the electrode pads 92 arranged in the X direction (as one line) from the start position P1 by the movement of the mounting table included in the XY stage 40 in the -X direction at a predetermined timing. When the imaging position exceeds the right end side of the semiconductor chip 91, the electrode pad 92 to be imaged is moved by one line in the Y direction due to the movement of the mounting table included in the XY stage 40 in the -Y direction. Subsequently, as the mounting table included in the XY stage 40 moves in the X direction, the electrode pads 92 arranged in the −X direction are similarly imaged sequentially at a predetermined timing. The above imaging operation is repeated, and all the electrode pads 92 in the semiconductor chip 91 are imaged, whereby the imaging position reaches the end position P2. Such an imaging operation is performed on all semiconductor chips. The above imaging operation is controlled by the computer 10. Hereinafter, the configuration and imaging operation of the computer 10 will be described.

<2. Computer Configuration and Imaging Operation>
The computer 10 is a general computer system such as a personal computer or a workstation. FIG. 3 is a block diagram showing a schematic configuration of the computer 10. The computer 10 includes a CPU (Central Processing Unit) 11 that performs various arithmetic processes, an input device such as an external keyboard and mouse, and an input / output interface 12 for connecting a display device such as an LCD or CRT to an internal bus 17. A RAM (Random Access Memory) 13 for temporarily storing data and programs, a ROM (Read Only Memory) 14 for storing predetermined programs in advance, a hard disk 16 as a large-capacity storage device, A hard disk 16 and a disk interface 15 for connecting the internal bus 17 are provided.

  The computer 10 receives an image signal Si from the CCD camera 20 by executing a predetermined program stored in the RAM 13 from an external storage medium such as a CD-ROM or a communication line via the input / output interface 12 or the like. Then, the trigger signal St is given to the CCD camera 20, the flash signal Sf is given to the light source 30, the encoder signal Se is received from the XY stage 40, and the motor control signal Sm is given to the XY stage 40. Hereinafter, each functional configuration and imaging operation of the computer 10 including these software processes will be described with reference to the drawings.

  FIG. 4 is a block diagram illustrating a functional configuration of the computer 10. The computer 10 receives an encoder signal Se and outputs a trigger signal St and a flash signal Sf at a predetermined timing, an XY stage control unit 120 that receives the encoder signal Se and outputs a motor control signal Sm, An image reading unit 130 that receives the image signal Si, a temporary storage unit 140 that temporarily stores the image data Di, an image trimming unit 150 that performs a predetermined trimming process on the image data Di, and the trimmed image data A large-capacity storage unit 160 that stores Di ′ for a needle mark inspection to be performed later, and a needle mark inspection unit 170 that performs a needle mark inspection based on image data Di ′ stored in the large-capacity storage unit 160 Prepare. The needle mark inspection unit 170 performs a needle mark inspection performed after an imaging operation described below, which will be described later.

  The trigger signal generation unit 110 performs an operation of writing predetermined data in a predetermined address of the RAM 13 in advance, and outputs the trigger signal St and the flash signal Sf at predetermined timing based on the encoder signal Se. Hereinafter, this operation will be described in detail with reference to FIG.

  FIG. 5 is a diagram for explaining the operation of generating the trigger signal St. As shown in FIG. 5, the trigger signal generator 110 includes, as functional components related to generation of the trigger signal St, a Y coordinate read address counter 112, an X coordinate read address counter 114, a selector 116, a memory 118, It has. The Y coordinate read address counter 112 counts the pulses indicated by the Y pulse signal (Y-Up Pulse) and outputs the count value as a memory address signal (Y coordinate address signal) corresponding to the Y coordinate. When Y-Reset) is input, the counter value is forcibly set to an address value corresponding to a predetermined Y coordinate corresponding to the reference position in the Y direction. The X coordinate read address counter 114 counts the pulses indicated by the X pulse signal (X-Encoder Pulse) and outputs the count value as a memory address signal (X coordinate address signal) corresponding to the X coordinate. When (X-Reset) is input, the counter value is forcibly set to an address value corresponding to a predetermined X coordinate corresponding to the reference position in the X direction. The Y coordinate address signal and the X coordinate address signal output from the Y coordinate read address counter 112 and the X coordinate read address counter 114 are input to the selector 116. The selector 116 also has a signal (hereinafter referred to as “write address signal”) indicating a write address for writing data (write DATA) to a memory address corresponding to the coordinates corresponding to the center of the electrode pad, and The data (hereinafter referred to as “write data”) is also input. The selector 116 selects one of two types of address signals, that is, a write address signal, a read address signal composed of a Y coordinate address signal, and an X coordinate address signal, and supplies the selected address signal to the memory 118. When the write address signal is selected at this time, write data is also given to the memory 118, and the write data is written to the address indicated by the write address signal in the memory 118. On the other hand, when the read address signal is selected, data at the address indicated by the read address signal is read from the memory 118 and output from the trigger signal generator 110 as the trigger signal St.

  The trigger signal generation unit 110 having the above-described configuration is an array of the semiconductor chips 91 included in the semiconductor wafer 90 from the wafer information storage unit 105 that stores information on the semiconductor wafer 90 given from the outside of the needle mark reading device. And array information Ia (for example, information on coordinates indicating the position of each electrode pad 92 in a predetermined coordinate system set with respect to the semiconductor chip 91) related to the array of the electrode pads 92 and the like are received as the array information Ia. Based on this, coordinates corresponding to the center positions of all electrode pads 92 to be imaged included in the semiconductor chip 91 (hereinafter referred to as “pad center coordinates”) are calculated. The calculated coordinates are converted into corresponding memory addresses, and data (here, “1”) indicating the center coordinates of the pad is written into the memory addresses in the memory 118. Specifically, as described above, the memory address is input to the selector 116 as a write address (Write Address), and write data (Write Data) of “1” is input to the selector 116. The selector 116 writes “1” to the corresponding address in the memory 118. Here, the memory address is set to uniquely correspond to the X coordinate. Therefore, since the straight line connecting the center coordinates of each electrode pad 92 in the X direction matches the straight line connecting the imaging position in the X direction, the X coordinate of the imaging position is specified by specifying the memory address.

  FIG. 6 is a schematic diagram for explaining the relationship between such an imaging position and a memory address. A square frame arranged along a straight line connecting the center coordinates of the electrode pad 92 shown in the figure in the X direction represents a memory address, and a number in the frame represents data written in the memory address. In FIG. 6, “1” is written in the memory address corresponding to the center coordinates of the pad, and the trigger signal generation unit 110 outputs the trigger signal St when the imaging position matches the position corresponding to this address. To do.

  Specifically, as shown in FIG. 5, every time a Y pulse signal included in the encoder signal Se from the XY stage 40 is input, a predetermined memory address corresponding to the Y coordinate is set by the Y coordinate reading address counter 112. , To the selector 116. When an X reset signal is input, a predetermined memory address corresponding to the X axis is set. Further, when a Y reset signal is input, reading is started from the first position of the memory address. Furthermore, each time an X pulse signal is input, the memory address is incremented by the X coordinate read address counter 114, and data is read sequentially from the memory address by the selector 116, and when “1” is read. The trigger signal St is immediately output. With this configuration, the electrode pad 92 is imaged when the center coordinate of the pad matches the imaging position.

  Strictly speaking, the time when the image is captured is the time when the flash signal Sf immediately after the trigger signal St is output, but there is no practical difference between the two because they are almost the same. Here, as shown in FIG. 2, it is assumed that the straight line connecting the center positions of the electrode pads 92 in the Y direction is parallel to the Y axis. That is, the arrangement pattern of the electrode pads 92 in the X direction is repeated in the Y direction.

  The XY stage control unit 120 receives an encoder signal Se indicating the position of the mounting table of the XY stage 40 on which the semiconductor wafer 90 is mounted, and generates a predetermined motor control signal Sm for moving the mounting table to a predetermined position. To the XY stage 40. Specifically, as described above with respect to the diagram shown in the lower half of FIG. 2, the stage for moving the XY stage 40 is moved so that the imaging position when imaging by the CCD camera 20 follows the locus indicated by the arrow in the diagram. Perform feedback control. This moving speed is a constant speed, and is equal to or longer than the time for acquiring one image (hereinafter referred to as “shooting time”) when images are sequentially acquired by the CCD camera 20 sequentially. The imaging position is determined to move from the center position of a certain electrode pad to the center position of the electrode pad adjacent in the X direction of the electrode pad in a long time. This is because if it is moved within a time shorter than this imaging time, it becomes impossible to image all the electrode pads (center position). Note that the shooting time is about 30 milliseconds, for example. The moving speed is not necessarily constant, but it is preferable that the moving speed is constant because the imaging condition at each imaging position is constant.

  The image reading unit 130 receives the image signal Si obtained by the CCD camera 20, and generates and outputs image data Di that is a captured image of the electrode pad and its vicinity from the image signal Si. The image data Di is temporarily stored in a predetermined area of the RAM 13 by the temporary storage unit 140.

  The image trimming unit 150 performs trimming processing on the image data Di stored by the temporary storage unit 140 to delete a predetermined area outside the captured image near the electrode pad 92, thereby trimming the image data Di. Generate '.

  FIG. 7 is a schematic diagram for explaining this trimming process. An image 51 in the figure corresponds to the image data Di, and the center coordinate of the electrode pad 92 matches the imaging position. A trimming boundary line 52 indicated by a dotted line includes a captured image of the electrode pad 92 and is set as a boundary line surrounding an area slightly larger than the surrounding area. The center position of the area inside the trimming boundary line 52 is It is set so as to coincide with the center coordinates of the electrode pad 92. Therefore, since the trimming boundary line 52 for the image 51 can be easily set, it is not necessary to perform trimming processing by recognizing the captured image of the electrode pad 92 by a known image recognition processing method, and the trimming boundary line 52 can be easily obtained. Trimmed image data Di ′ composed of a captured image of the internal electrode pad 92 can be generated. The trimmed image data Di ′ is stored in the hard disk 16 via the disk interface 15 by the large-capacity storage unit 160. Note that the image data Di ′ stored by the large-capacity storage unit 160 is a target for a needle mark inspection to be performed later by the needle mark inspection unit 170. A processing procedure related to the imaging operation of the computer 10 corresponding to the above functions will be described below with reference to the drawings.

  FIG. 8 is a flowchart illustrating a processing procedure related to the imaging operation of the computer 10. The trigger signal generator 110, which is a function of the computer 10, receives the array information Ia related to the array of the semiconductor chips 91 and the array of the electrode pads 92 included in the semiconductor wafer 90 from the wafer information storage unit 105 described above. The center coordinates of all electrode pads 92 included in the chip 91 are calculated, the calculated coordinates are converted into corresponding memory addresses, and data “1” indicating the pad center coordinates is stored in the memory address. An initial setting process for writing is performed (step S10). Here, the center coordinates of all the electrode pads 92 included in all the semiconductor chips may be calculated and written to the corresponding memory addresses.

  Next, the XY stage control unit 120 moves a predetermined position for moving the position of the mounting table of the XY stage 40 on which the semiconductor wafer 90 is mounted so that the predetermined start point P1 is aligned with the imaging position of the CCD camera 20. A motor control signal Sm is generated and applied to the XY stage 40. Furthermore, when the predetermined start point P1 is set to the imaging position of the CCD camera 20, the mounting table is moved in the X direction at a constant moving speed based on the encoder signal Se indicating the position of the mounting table that is continuously received. A predetermined motor control signal Sm for movement is applied to the XY stage 40 (step S20).

  Next, the trigger signal generation unit 110 determines whether the center coordinates of the pad match the imaging position based on the encoder signal Se (Step S30). If they do not match, the determination in step S30 is repeated. If they match, the trigger signal generator 110 outputs the trigger signal St (step S40). As described above, the flash signal Sf is output immediately after the trigger signal St is output.

  Next, the image reading unit 130 receives the image signal Si obtained by the CCD camera 20, generates image data Di that is a captured image of the electrode pad and its vicinity from the image signal Si, and the temporary storage unit 140 stores the image signal Di. Data Di is temporarily stored (step S50).

  Next, since the imaging position of the CCD camera 20 exceeds the center coordinates of the electrode pad 92 at the farthest end in the X direction, the XY stage control unit 120 finishes reading the image in the X direction based on the encoder signal Se. It is determined whether or not to perform (step S60). If not finished, the process returns to step S30, and the process of sending a trigger signal at the trigger time is repeated until the image reading in the X direction is finished (S60 → S30 → S40 → S50 → S60). When the reading of the image in the X direction is terminated, it is further determined whether or not the imaging position has reached the end point P2 (step S70). If not, the process from step S80 to S110 described below is performed, then the process returns to step S30, and the above process is repeated until the imaging position reaches the end point P2 (S70 → S80 → S90 → S100 → 110). → S30 → S40 → S50 → S60 → S70). Here, the processing from step S80 to S110 will be described.

  If it is determined in step S70 that the imaging position has not reached the end point P2, the XY stage control unit 120 adjusts the imaging position of the CCD camera 20 to the Y coordinate corresponding to the next electrode pad row. Then, a predetermined motor control signal Sm for moving the position of the mounting table of the XY stage 40 on which the semiconductor wafer 90 is mounted is generated and applied to the XY stage 40 (step S80).

  Next, the image trimming unit 150 performs a trimming process on the image data Di stored in the temporary storage unit 140 to cut out a predetermined area other than the area including the captured image of the electrode pad 92, thereby trimming the image. Data Di ′ is generated (step S90). This trimming process is performed collectively for all image data Di (specifically, captured images of all electrode pads 92 arranged in the X direction) stored by the temporary storage unit 140.

  Next, the image trimming unit 150 creates data obtained by adding additional information including a predetermined number and an annotation used for the needle mark inspection by the needle mark inspection unit 170 to the trimmed image data Di ′. (Step S100). Furthermore, the large-capacity storage unit 160 stores the data to which the additional information is added by the image trimming unit 150 (step S110). Thereafter, as described above, the process returns to step S30, and the above process is repeated until the imaging position reaches the end point P2.

  The above processing from step S90 to S110 is performed using the moving time for moving the position of the mounting table of the XY stage 40 in the processing of step S80. When the processing speed of the computer 10 and the storage speed of the hard disk 16 are sufficiently high, these processes may be performed immediately after the image capturing process of step S50. Moreover, these processes may be performed in parallel with the process of step S80 (and processes executed thereafter).

  If it is determined in step S60 that the imaging position has reached the end point P2, the image reading operation regarding the semiconductor chip ends. If there is a semiconductor chip from which an image is further read, the above-described processing is started from the beginning after the needle mark inspection operation described below is completed.

<3. Computer needle mark inspection operation>
Next, a processing procedure related to the needle mark inspection operation of the computer 10 will be described with reference to the drawings. Here, the needle mark inspection operation includes an image of an electrode pad including a needle mark as a model and an electrical characteristic inspection (hereinafter referred to as “probe test”) that forms a needle mark to be a target of the needle mark inspection operation. The captured image of the electrode pad 92 included in the semiconductor chip 91 before performing the above is required. Therefore, an overall processing procedure including the needle mark inspection operation will be described.

  FIG. 11 is a flowchart showing an overall processing procedure when performing a needle mark inspection in the present embodiment. In step S1, imaging for registering ideal needle marks formed on all electrode pads included in a predetermined semiconductor chip as a model (model registration imaging process) is performed. Specifically, when there is no abnormality in a predetermined inspection probe to be subjected to needle mark inspection (for example, when it is new), other needle marks are used to clarify the position of the newly formed needle mark. Needle marks are formed on a dummy wafer or a new chip that does not exist using the predetermined inspection probe. Since the needle marks formed in this manner are almost in an ideal state without any abnormality in their positions, etc., all the images of the electrode pads on which the needle marks are formed are imaged for use in the following needle mark inspection operations. Do. Since this imaging operation is exactly the same as the imaging operation described with reference to FIG.

  In step S2, by analyzing the image of the electrode pad including the needle mark that becomes the model obtained by the imaging process for model registration (step S1), the center-of-gravity coordinates of the needle mark that becomes the model are calculated and stored ( Model registration processing) is performed. A known method is used to calculate the barycentric coordinates by such image analysis. For example, the pixel constituting the area occupied by the needle mark or the boundary included in the image is detected based on the luminance of the pixel, and the barycentric coordinate of the needle mark is calculated based on the coordinates of these pixels. Note that the barycentric coordinates are coordinates in a predetermined coordinate system set in advance with respect to the semiconductor chip 91, and that the array information Ia including information related to the coordinate system is stored in the wafer information storage unit 105 as described above. did. The barycentric coordinates are calculated for all needle marks, and are stored in the large-capacity storage unit 160 together with information such as a predetermined number used when the needle mark inspection unit 170 performs the needle mark inspection. In the following, various calculations are performed based on the barycentric coordinates of the needle mark, but if it is the coordinates of a feature point (for example, the pixel coordinate of the minimum Y coordinate) indicating the property included in all the needle marks, It can also be used instead of the barycentric coordinates.

  Here, the information obtained by the processes in steps S1 and S2 can be used repeatedly until the predetermined inspection probe is abnormal. Therefore, these processes need only be performed once when the inspection probe is used for the first time. Further, when the predetermined inspection probe can be attached to any of the plurality of inspection apparatuses, the information may be shared by the plurality of inspection apparatuses via a predetermined network. Good.

  In step S3, imaging of the electrode pads included in the semiconductor chip 91 before the probe test (difference calculation imaging processing) is performed. This imaging process may be performed for all the electrode pads included in the predetermined semiconductor chip 91, or may be performed only for the four electrode pads arranged near the corners of the semiconductor chip 91. Further, it may be performed on electrode pads of all semiconductor chips included in the semiconductor wafer 90. By performing the difference calculation between the image obtained by this imaging process and the image after the probe test, even when a plurality of needle marks are formed on one electrode pad, the needle marks formed by the probe test are formed. Only can be detected. However, in this embodiment, the difference calculation is not performed for all the electrode pads, but the detailed contents thereof will be described later. In addition, since the image of the electrode pad obtained by this imaging process for difference calculation can be used in the detailed inspection of the needle mark (step S7 described later), when used for this detailed inspection, the above-described imaging processing is performed for all semiconductors. It is preferably performed on the chip.

  In step S <b> 4, a probe test is performed on all semiconductor chips included in a predetermined semiconductor wafer 90 by a predetermined probe test apparatus equipped with the predetermined inspection probe. By this probe test, a needle mark to be subjected to a needle mark inspection is formed on the electrode pad.

  In step S5, imaging of the electrode pad including the needle trace formed by the probe test (imaging processing for needle trace inspection) is performed by the present needle trace reading device. This operation is the imaging operation described with reference to FIG. Unlike the case of the model registration imaging process (step S1), the image of the electrode pad acquired by imaging here is different (for example, before the previous time) in addition to the needle marks formed by the probe test. There may be one or more needle marks formed by the probe test.

  In step S6, a predetermined needle mark inspection process is performed based on the electrode pad image obtained by the needle mark inspection imaging process (step S5). Details of this process will be described later.

  In step S7, further detailed inspection is performed based on the result obtained in step S6 (needle mark inspection processing). For example, an image of an electrode pad including a needle mark determined to be defective by the needle mark inspection process is read from the large-capacity storage unit 160, and the shape and size of the needle mark are analyzed in detail. This detailed inspection is typically performed by visual inspection of the operator. This detailed inspection may be omitted as necessary.

  Next, a detailed procedure of the needle mark inspection process shown in step S6 will be described. FIG. 12 is a flowchart showing a processing procedure related to the needle mark inspection operation of the computer 10.

  First, the needle mark inspection unit 170, which is a function realized by the computer 10, is a vector (how much the position of the needle mark formed by the probe test changes from the position of the needle mark registered as a model ( Hereinafter, initial vector calculation processing for calculating “initial vector” is performed (step S210). Here, detailed processing (subroutine) of the initial vector calculation processing will be described with reference to FIG. FIG. 13 is a flowchart showing the procedure of this subroutine.

  The needle mark inspection unit 170 includes four electrode pads (hereinafter referred to as four electrode pads) arranged in the corners of the semiconductor chip 91, that is, in the vicinity of the four corners, of the image of the electrode pad obtained by the image processing for needle mark inspection (step S5). The image data of “corner pad” is read from the large-capacity storage unit 160 (step S211).

  Next, the needle mark inspection unit 170 detects the needle mark formed by the probe test from the corner pad image obtained in step S211 (step S212). Here, when only one needle mark is included in the corner pad image, it is extremely easy to detect the needle mark, but as described above, the needle pad formed by the probe test is included in the corner pad image. In addition to the marks, one or more needle marks formed by different (previous and previous) probe tests may be included. In this case, by calculating the difference between the corner pad image obtained in the difference calculation imaging process (step S3) from the corner pad image obtained in step S211, the current pad test is performed. The needle marks formed by the probe test are detected. FIG. 14 is a diagram for explaining the difference calculation. Image A in the figure shows an image of a corner pad before the probe test, and image B shows an image of the corner pad after the probe test. When the difference between the image A and the image A is calculated, the common part of both images indicated by the dotted line in the image C is removed, so that only the needle mark formed by the current probe test is included as shown in the image C. An image of the corner pad is obtained. Hereinafter, this needle mark is referred to as a corner needle mark.

  Subsequently, the needle mark inspection unit 170 calculates the barycentric coordinates of the corner needle marks from the corner pad image including the corner needle marks obtained in step S212 (step S213). The known method for calculating the center-of-gravity coordinates is as described above in the model registration process (step S2), and the center-of-gravity coordinates are coordinates in a predetermined coordinate system preset for the semiconductor chip 91. It is also as described above.

  Next, the needle mark inspection unit 170 calculates the center position Ci of these barycentric coordinates from the barycentric coordinates of the corner needle marks obtained in step S213 (step S214). Since the center of gravity of the needle mark does not necessarily match the center position of the electrode pad, the center position Ci is the vicinity that does not match the center position of the semiconductor chip 91.

  Further, the needle mark inspection unit 170 is a needle mark that becomes a model of an electrode pad located in the vicinity of the four corners of the semiconductor chip among the barycentric coordinates of the needle mark that becomes a model stored by the model registration process (step S1). The center-of-gravity coordinates (hereinafter referred to as “model corner needle marks”) are read from the large-capacity storage unit 160 (step S215).

  Subsequently, the needle mark inspection unit 170 calculates the center position Cm of these barycentric coordinates from the barycentric coordinates of the model corner needle marks read in step S215 (step S217). The center position Cm is the center position of the semiconductor chip 91 and its vicinity that does not coincide with the center position Ci.

  Finally, the needle mark inspection unit 170 calculates a vector (hereinafter referred to as “initial vector”) from the center position Cm calculated in step S216 to the center position Ci calculated in step S214 (step S214). This initial vector is used as a vector indicating the deviation from the needle mark registered in the model to the needle mark formed by the probe test in the subsequent processing. When the subroutine processing described above ends, the processing returns to the processing shown in FIG.

  Here, the reason why the initial vector is calculated based on the center position Ci calculated based on the center of gravity coordinates of the corner needle marks and the center position Cm calculated based on the center of gravity coordinates of the model corner needle marks will be described with reference to FIG. explain in detail. FIG. 15 is a schematic diagram for explaining the initial vector calculation. The semiconductor chip 910 shown in the figure has six electrode pads 921 to 926, and these electrode pads include needle marks 931 to 936 formed by a probe test. In the drawing, needle marks 831 to 836 registered as models corresponding to these needle marks are indicated by dotted lines, and the center of gravity of the needle marks is indicated by the center position of the cross mark. The intersection of the line segment connecting the center of gravity of the corner needle marks 933 and 934 of the semiconductor chip 910 and the line segment connecting the center of gravity of the corner needle marks 931 and 936 becomes the center position Ci of these needle marks. Similarly, the intersection of the line segment connecting the center of gravity of the model corner needle marks 833 and 834 and the line segment connecting the center of gravity of the model corner needle marks 831 and 836 becomes the center position Cm of these needle marks.

  The initial vector Vi, which is a vector from the center position Cm to the center position Ci, is shifted from the center of gravity of the model corner needle marks 831, 833, 834, 836 to the center of gravity of the corresponding corner needle marks 931, 933, 934, 936. Is not exactly equal to the vector. Because the inspection probe (for example, a new article) having a needle mark as a model is almost ideally arranged, all the vectors indicating the direction in which the inspection probe is shifted should be the same and equal to the initial vector. However, an inspection probe that has undergone a plurality of probe tests has a deviation from an ideal arrangement due to aging, such as bending, chipping, and wear, and further, a deviation from the ideal position occurs when the semiconductor chip 910 is positioned. Because. In particular, when the semiconductor chip 910 is mounted on the XY stage 40, a slight deviation often occurs from the ideal position in the X and Y directions or in the rotational direction. Then, a relatively large variation in the amount of deviation in the rotational direction is observed in the corner pads of the semiconductor chip 910. Therefore, in the present embodiment, in order to average the deviation amount in the rotational direction and other deviation amounts, the initial vector is calculated as described above, focusing on the corner needle marks. In order to completely average the deviation amount, it is preferable to calculate a vector from the needle traces as models to the needle traces formed by the probe test for all the electrode pads, but the calculation amount increases. Therefore, the process takes a lot of time. Therefore, it is not preferable for detecting a needle mark at high speed. In this respect, the above-described configuration for calculating the initial vector by paying attention to the four corner pads can particularly average the deviation amount in the rotational direction sufficiently accurately and calculate the initial vector at high speed. Is preferred.

  In this embodiment, the initial vector is calculated based on the center position Ci and the center position Cm, but the corresponding corner needle is calculated from the average position of some or all of the center of gravity positions of the model corner needle marks 831, 833, 834, and 836. A vector to the average position of some or all of the gravity center positions of the marks 931, 933, 934, and 936 may be used as the initial vector. Further, the initial vector may be calculated based on a model corner needle mark and a predetermined needle mark other than the corner needle mark.

  Referring to FIG. 12 again, when the initial vector calculation process (step S210) ends, next, the needle mark inspection unit 170 performs a determination range calculation process for determining the quality of the needle mark (step S220). . As described above, the needle mark formed on the electrode pad by the probe test is in the vicinity of the position moved by the direction and distance indicated by the initial vector from the model needle mark unless there is an abnormality in the inspection probe. A range indicating a limit for being in the vicinity is referred to as a determination range here. This determination range includes a deviation amount of a needle mark position formed by a predetermined inspection probe as one model, and a maximum deviation amount of all needle mark positions formed by an inspection probe as all models. It is necessary to determine in consideration of the amount of deviation caused by the secular change due to the multiple probe tests. Hereinafter, a description will be given with reference to FIGS. 16 and 17.

  FIG. 16 is a schematic diagram for explaining the shift amount generated by the first probe Pr1, and FIG. 17 is a schematic diagram for explaining the shift amount generated by the second probe Pr2. In these drawings, Ra indicates the amount of displacement of the needle mark position formed by the first and second probes Pr1 and Pr2 having different shapes, and the dotted line indicates the range of the displacement. The deviation Ra is obtained by numerical calculation in advance from the amount of bending or bending calculated based on the shapes of the first and second probes Pr1 and Pr2, the rigidity of the metal that is the material, the applied load, and the like. be able to.

  In addition, RM indicates the maximum deviation amount of all needle mark positions formed by all the inspection probes used when the first and second probes Pr1 and Pr2 are modeled inspection probes. Yes. This deviation amount RM can be easily obtained from the positions of the needle marks registered in all models. For example, the difference between the minimum value and the maximum value is calculated for the X and Y coordinates of the center of gravity coordinates of the needle mark registered in the model, and Ra is added to the value obtained by dividing the larger value by 2 It is conceivable that the value obtained is RM. The reason why the deviation amount RM is larger than the deviation amount Ra is that there is a slight variation in the shape or the like of each inspection probe, or the attachment position is slightly displaced from the calculated position.

  Further, RT indicates the maximum deviation amount of all the needle mark positions formed by all the inspection probes in consideration of deviation caused by aging due to a plurality of probe tests. This deviation amount RT can be easily obtained from the positions of all the actually formed needle marks, but on the other hand, since the calculation amount increases, the processing takes a lot of time. Therefore, it is not preferable for detecting a needle mark at high speed. Therefore, the deviation amount RT is calculated by multiplying the deviation amount RM by a predetermined coefficient larger than 1 obtained by empirically considering the influence of the aging. The calculation may be performed in consideration of the deviation amount of the four corner needle marks. The needle mark inspection unit 170 sets the inside of a circle having the radius of the calculated deviation amount RT as the determination range.

  Subsequently, the needle mark inspection unit 170 reads an image of the electrode pad to be subjected to the needle mark inspection from the large-capacity storage unit 160 (step S230). Next, the needle mark inspection unit 170 performs a quality determination process of the needle marks included in the read electrode pad image (step S240). Here, a detailed process (subroutine) of the pass / fail determination process will be described. FIG. 18 is a flowchart showing the procedure of this subroutine.

  The needle mark inspection unit 170 reads the barycentric coordinates of the needle mark registered as a model corresponding to the electrode pad read in step S230 from the large-capacity storage unit 160 (step S241).

  Next, the needle mark inspection unit 170 calculates the coordinates of a point that is separated by the direction and distance of the initial vector calculated in step S230 from the barycentric position of the needle mark that is the model read in step S230. The center coordinates of the range are set (step S242). Ideally, there is a barycentric coordinate of the needle mark formed by the probe test in the vicinity of this point (the above-mentioned central coordinate), and therefore the determination range may be set around this point.

  Subsequently, the needle mark inspection unit 170 sets, as the determination range, a circle centered on the center coordinates of the determination range calculated in step S242 and having a radius of the deviation amount RT calculated in step S220 (step S243). Although the determination range is circular here, it may have any shape such as a square.

  Furthermore, the needle mark inspection unit 170 detects a needle mark from a predetermined region of the electrode pad image within the determination range set in step S243 (step S244). A known image processing method such as a detection method based on pixel luminance is used for detection of the needle marks. As described above, in the present embodiment, since the needle mark only in a predetermined region within the determination range is detected, it is not necessary to examine the entire image of the electrode pad. Therefore, the needle mark can be detected at high speed.

  Subsequently, the needle mark inspection unit 170 determines whether or not a needle mark is detected in step S244 (step S245). When the needle mark is detected, it is determined that the needle mark is good, and the determination result is temporarily stored in a memory or the like, and the process returns to the process of FIG. 12 (step S246). If the needle mark is not detected, it is determined that the needle mark is defective, the determination result is temporarily stored in a memory or the like, and the process returns to the process of FIG. 12 (step S247). In step S244, when a part of the needle mark is detected within the determination range, the entire needle mark is not detected, so that the needle mark is not detected.

  FIG. 19 is a diagram illustrating an example of needle mark detection in the needle mark quality determination process as described above. The electrode pad image 927 shown in the figure includes needle marks 937 formed by the current probe test and needle marks 957a, 957b, and 957c formed by the previous probe test. In the figure, the needle mark 837 registered as a model corresponding to the needle mark 937 is indicated by a dotted line, and the barycentric position of the needle mark is indicated by the center position of the cross mark. Referring to FIG. 19, since there is a needle mark 937 within a circle having a radius RT from the center coordinate of the determination range, the needle mark is detected from an image within this circular determination range. Therefore, this needle mark 937 is determined to be good.

  FIG. 20 is a diagram illustrating another example of needle mark detection in the needle mark quality determination process. Since each element in this figure is the same as that in FIG. 19, the same reference numeral is assigned to the same element, and the description thereof is omitted. However, unlike the example shown in FIG. 19, the example shown in FIG. 20 has a needle mark 937 outside the circle with the radius RT from the center coordinate of the determination range. Not detected. Therefore, this needle mark 937 is determined to be defective.

  Referring to FIG. 12 again, when the above-described quality determination process (step S240) of the needle mark is completed, the needle mark inspection unit 170 then determines that the needle mark is defective based on the determination result of the quality determination process. If YES, the process of step S260 is omitted and the process of step S270 is performed. If the needle mark is good, the process of step S260 is performed (step S250).

  Subsequently, the needle mark inspection unit 170 performs a needle mark position determination process for determining whether or not the needle mark position is good for the needle marks determined to be good (step S260). Usually, a protective part (passivation part) is formed in the vicinity of the periphery of the electrode pad, and if the area occupied by the needle mark overlaps the area of the protective part, problems such as poor conduction in the probe test may occur. is there. Therefore, when the above overlap occurs, it is necessary to determine that the needle mark position is defective. Therefore, specifically, the maximum and minimum values of the X and Y coordinates of the needle mark are calculated, and by determining whether or not these coordinates are within the region of the protection unit, the quality of the needle mark position is determined. Determine.

  FIG. 21 is a diagram showing the maximum and minimum values of the X coordinate and Y coordinate of the needle mark. In the figure, Xmax indicates the maximum value of the X coordinate of the needle mark, Xmin indicates the minimum value of the X coordinate, Ymax indicates the maximum value of the Y coordinate, and Ymin indicates the minimum value of the Y coordinate. In the image 927 of the electrode pad shown in the figure, a protective part is formed in the vicinity of the periphery, and since Xmax, Xmin, Ymax, and Ymin are not in the protective part, the region occupied by the needle mark 937 is the protective part. It can be determined that there is no duplication.

  Of course, if the area occupied by the needle mark 937 is close to this protective part, there is a possibility that a problem may occur, and therefore a detailed inspection (step S7) may be required. Therefore, in the needle mark position determination process, the degree of proximity between the area occupied by the needle mark 937 and the protection unit is also determined. Hereinafter, a description will be given with reference to FIG. FIG. 22 is a diagram showing a boundary line for determining the degree of proximity. When any value of Xmax, Xmin, Ymax, Ymin is a coordinate corresponding to the outside of the first boundary line 901, it can be said that the needle mark is very close to the inside of the protection part or the protection part. If the position is determined to be defective and the coordinates correspond to the inside of the first boundary line 901 and the coordinates correspond to the outside of the second boundary line 902, the needle mark does not overlap with the protective part. Since it can be said that they are relatively close to each other, it is determined that the needle mark position needs to be investigated, and when the coordinates correspond to the inside of the second boundary line 902, it can be said that the needle mark is away from the protection unit. Therefore, it is determined that the needle mark position is good. Such a determination result (whether it is defective, needs investigation, or is good) is temporarily stored in a memory or the like.

  Referring to FIG. 12 again, when the above-described needle mark position determination process (step S260) is completed, needle mark inspection unit 170 then performs a predetermined classification based on various determination results temporarily stored in a memory or the like. Processing for creating a header is performed (step S270). This classification header includes, for example, test date, test machine number, needle model (model needle mark) number, wafer product name, wafer lot number, chip number, pin (electrode pad) number, needle determination (needle mark pass / fail determination) result, Needle position determination results, predetermined needle mark detection parameters, and the like are included. The needle determination (needle mark pass / fail determination) result is obtained by data indicating “good” or “bad”, which is a result obtained by the needle mark pass / fail determination process (step S240), and the determination range calculation process (step S220). And a deviation amount RT. The needle position determination result includes data indicating “defective”, “required investigation”, or “good” which is a result obtained by the needle mark position determination process (step S260). The predetermined needle mark detection parameter includes the barycentric coordinates of the needle mark, the values of Xmax, Xmin, Ymax, and Ymin, and may further include the area and aspect ratio of the needle mark obtained by predetermined calculation. The classification header including the above contents is associated with (associated with) the image file of the electrode pad and stored in the large-capacity storage unit 160 (a predetermined folder thereof). With such a classification header, an electrode pad image to be inspected can be efficiently designated and taken out at the time of a detailed inspection (step S7) to be performed later.

  Next, the needle mark inspection unit 170 determines whether or not the images of all the electrode pads included in the semiconductor chip 91 have been read and inspected (step S280). If all images have not been read, the process returns to step S230 to read the next electrode pad image, and the above processing is repeated until all images are read (S230 → S240 → S250 → (S260) → S270 → S280 → S230). When all the images are read, the inspection of all the needle marks included in the semiconductor chip 91 is completed. Subsequently, the imaging operation of the electrode pad included in the next semiconductor chip included in the semiconductor wafer 90 is performed, and the same processing (steps S210 to S270) as described above is started in order to perform the needle mark inspection of the electrode pad. Is done. This process is repeated until the imaging operation and the needle mark inspection operation for all the semiconductor chips included in the semiconductor wafer 90 are completed.

  Note that the needle mark inspection operation of the computer 10 including the above processing (steps S210 to S270) is performed after the imaging operation of the electrode pad of the semiconductor chip is completed. If the processing speed of the computer 10 is sufficiently high, one electrode Each time the pad is imaged, a needle mark inspection operation may be performed on the electrode pad. Further, these operations may be performed in parallel.

<4. Effect>
According to the one embodiment, the needle mark reading device moves the semiconductor wafer 90 placed on the placement table by the XY stage 40 at a constant speed in the X direction, and is illuminated by the flash of the light source 30. The pad is sequentially imaged by the CCD camera 20. With this configuration, the present needle mark reading device can read the needle mark by acquiring an image of the electrode pad in a short time without any trouble for the user.

  In addition, according to the above-described embodiment, the needle mark reading apparatus is configured to sequentially image the electrode pads that are illuminated for a short time by the flash of the light source 30 by the CCD camera 20. With this configuration, the needle mark reading device can prevent a blur in the captured image, and can acquire an image with a device configuration that is easier and less expensive than control by a physical shutter device or the like. it can.

  Furthermore, according to the above-described embodiment, the trigger signal generation unit 110 included in the present needle mark reading device includes the array information on the array of the semiconductor chips 91 and the array of the electrode pads 92 stored in the wafer information storage unit 105. Based on Ia, coordinates corresponding to the center positions of all electrode pads 92 to be imaged are calculated. This makes it possible to read a large number of needle marks formed on a large number of electrode pads that are not necessarily arranged at equal intervals and whose arrangement position may change depending on the semiconductor wafer.

  Furthermore, according to the above-described embodiment, the needle mark reading device performs time-difference image calculation only when calculating the initial vector. In other needle mark inspections, the initial vector and a predetermined determination range ( The quality of the needle mark is determined based on the deviation amount RT). As a result, even if a plurality of needle marks are included in the image obtained by photographing the electrode pad, the quality of the needle marks formed by the last probe test, the quality of the needle mark positions, and the like can be determined at high speed. . For example, if the difference calculation is performed by subtracting the image before the probe test from the electrode pad image for 1000 pins, the time required for one difference calculation is about 200 milliseconds, Since the time required to read one image is about 30 milliseconds, all the needle mark inspections take about 230 seconds (about 4 minutes). On the other hand, when the needle mark inspection in the present embodiment is performed on the image of the electrode pad for 1000 pins, the time required for detecting one needle mark is about 10 milliseconds. The inspection is completed in about 10 seconds. Therefore, it can be seen that the needle mark inspection in the present embodiment is performed at a very high speed. In addition, the above difference calculation in units of pixels may cause erroneous detection due to misalignment at the time of image acquisition. However, according to the needle mark inspection operation in the present embodiment, relative position detection based on the initial vector is performed. Therefore, the needle mark inspection can be accurately performed without being affected by a shift at the time of image acquisition or a change in brightness of pixels.

<5. Modification>
In the above embodiment, since the center coordinates of the electrode pad 92 (the image 51 including the captured image) coincide with the imaging position, the electrode pad 92 included in the image data Di is configured as one, There may be a plurality of electrode pads 92 to be imaged at one time. For example, when the image pickup position matches the midpoint position of a straight line connecting the center positions of adjacent electrode pads, that is, the intermediate position of adjacent electrode pads, the number of electrode pads 92 included in the image data Di is two. The

  FIG. 9 is a diagram illustrating an image 51 including captured images of the two electrode pads 92a and 92b with this configuration. The center positions of the regions inside the trimming boundary lines 52a and 52b corresponding to the electrode pads 92a and 92b can be easily calculated from the array information Ia regarding the array of the electrode pads 92a and 92b indicated by the wafer information storage unit 105. Can do. Therefore, the trimming boundary lines 52a and 52b for the image 51 can be easily set. Therefore, it is not necessary to perform the trimming process by recognizing the captured images of the electrode pads 92a and 92b by a known image recognition process. It is possible to generate two trimmed image data Di ′ composed of captured images of the electrode pads 92a and 92b inside the boundary lines 52a and 52b.

  Here, when the CCD camera 20 has a very high resolution, it is possible to obtain more images of the electrode pads by a single imaging operation. FIG. 10 is a diagram illustrating an image 51 including captured images of the four and a half electrode pads 92a to 92e. Similarly, the center positions of the trimming boundary lines 52a to 52e corresponding to the captured images of the electrode pads 92a to 92e can be easily calculated from the array information Ia regarding the electrode pad array and the like indicated by the wafer information storage unit 105. Therefore, it is possible to easily generate a plurality of trimmed image data Di ′ including captured images of the electrode pads 92a to 92e inside the trimming boundary lines 52a to 52e. However, although the entire electrode pad 92e is not captured here, it is discarded, but the entire image may be generated by combining with the remaining portion of the image to be captured next.

  As described above, according to the configuration in which images of two or more electrode pads are acquired by a single imaging operation, images of two or more electrode pads are sequentially obtained in a shooting time when one image is acquired by the CCD camera 20. Since it can be acquired, the XY stage 40 (mounting table) can be moved at a moving speed that is twice or more. Therefore, with this configuration, the present needle mark reading device can acquire the image of the electrode pad and read the needle mark in a shorter time. In the above modification, the plurality of electrode pads to be imaged are adjacent to each other in the X direction as shown in FIG. 10, but each of the plurality of electrode pads adjacent to the Y direction or each of the X direction and the Y direction is used. A configuration may be employed in which a plurality of adjacent electrode pads are imaged at a time. In this configuration, since the moving distance in the Y direction of the imaging position performed after reading in the X direction can be increased (for example, movement of two or more rows), an electrode pad image can be acquired in a short time. Needle marks can be read.

  In the above embodiment, the CCD camera 20 obtains a non-blurred captured image by emitting a high-intensity flash for a short time of about several microseconds from the time when the light source 30 is given the flash signal Sf. Yes. However, in the case of a configuration for acquiring a non-blurred captured image, the optical path is normally interrupted at some point along the optical path from the light source 30 through the semiconductor wafer 90 to the light receiving element built in the CCD camera 20. The shutter may be newly provided with a shutter device that operates to open the optical path for a short time at a predetermined time. The shutter device may be realized electronically. According to these configurations, the light source 30 is not limited to a flash such as a xenon flash lamp. Further, in order to acquire a captured image without blurring by the CCD camera 20, the XY stage 40 may be controlled so that the moving speed is decelerated before the electrode pad is moved to the imaging position. However, in this configuration, since the acceleration and deceleration are repeated, the average speed becomes slow. Therefore, the structure of the said embodiment moved at a fixed fast speed is more suitable.

  In the above embodiment, the position of the semiconductor wafer 90 to be imaged is moved by the XY stage 40 so that the imaging position moves continuously. However, instead of the XY stage 40, the position of the CCD camera 20 or imaging A configuration in which a camera moving device or a camera swing device that moves the imaging position in the X direction and the Y direction by changing the angle may be provided. Further, the XY stage 40 is omitted, and the reflecting mirror is arranged so that the image of the electrode pad 92 is given to the CCD camera 20 via the reflecting mirror, and the angle of the reflecting mirror is changed, whereby the imaging of the CCD camera 20 is performed. The reflection angle changing device that moves the position in the X direction and the Y direction may be provided. Furthermore, the structure which moves an imaging position continuously by combining these structures suitably may be sufficient.

  In the above embodiment, the electrode pads 92 included in one semiconductor chip in the semiconductor wafer 90 are sequentially imaged, but the entire semiconductor wafer 90 may be sequentially imaged. In other words, when imaging in the X direction, the electrode pads 92 included in a plurality of semiconductor chips may be sequentially imaged. Even when imaging is performed in this way, it is possible to easily determine which semiconductor chip corresponds to the imaged electrode pad based on the array information Ia related to the array of semiconductor chips indicated by the wafer information storage unit 105. Can do.

  In the above embodiment, the feedback control is performed based on the encoder signal Se from the XY stage 40, but the position where the XY stage 40 should be placed by the XY stage control unit 120 without being based on the encoder signal Se. May be configured to be controlled based on the desired position.

  In the above embodiment, the needle mark inspection operation is performed on the image of the electrode pad obtained by continuously imaging the semiconductor wafer 90 on the XY stage 40 (mounting table) moving at a constant speed by the CCD camera 20. However, in order to realize the above-described needle mark inspection operation, it is sufficient that a captured image of the electrode pad exists. Therefore, as a premise of the needle mark inspection operation, it is not always necessary to perform the imaging operation. For example, an image of an electrode pad may be acquired by a conventional imaging operation, or may be captured by a device different from the present device. An image of the electrode pad may be provided to the apparatus, and the needle mark inspection operation may be performed based on the provided image. Thus, the description of the above embodiment can also be applied to a needle mark inspection apparatus that performs only the needle mark inspection operation.

  In the embodiment and the modification, the electrode pad 92 included in the semiconductor chip is imaged. However, the present invention images or inspects the electrode pad included in a predetermined inspection object other than the semiconductor chip. It can be applied to any configuration. In such a case, the coordinates of each electrode pad in a predetermined coordinate system set for the object to be inspected can be easily calculated based on predetermined arrangement information relating to the arrangement of the electrode pads and the like. .

It is a block diagram which shows the structure of the needle mark reading apparatus which concerns on one Embodiment of this invention. It is a figure for demonstrating the imaging operation which concerns on the said one Embodiment. It is a block diagram which shows the schematic structure of the computer in the said one Embodiment. It is a block diagram which shows the function structure of the computer in the said one Embodiment. It is a figure for demonstrating the operation | movement which generates the trigger signal St in the said one Embodiment. It is a schematic diagram for demonstrating the relationship between the imaging position and memory address in the said one Embodiment. It is a schematic diagram for demonstrating the trimming process in the said one Embodiment. It is a flowchart which shows the process sequence relevant to the imaging operation of the computer in the said one Embodiment. It is a figure which illustrates the image 51 containing the picked-up image of the two electrode pads 92a and 92b in the modification of the said one Embodiment. It is a figure which illustrates the image 51 containing the picked-up image of the four and a half electrode pads 92a-92e in the modification of the said one Embodiment. It is a flowchart which shows the whole process sequence at the time of performing the needle mark inspection in this embodiment. It is a flowchart which shows the process sequence relevant to the needle mark test | inspection operation | movement of the computer in the said one Embodiment. It is a flowchart which shows the detailed process sequence of the initial vector calculation process in the said one Embodiment. It is a figure for demonstrating the difference calculation of the image in the said one Embodiment. It is a schematic diagram for demonstrating the initial vector calculation in the said one Embodiment. It is a schematic diagram for demonstrating the deviation | shift amount produced by the 1st probe in the said one Embodiment. It is a schematic diagram for demonstrating the deviation | shift amount produced by the 2nd probe in the said one Embodiment. It is a flowchart which shows the detailed procedure of the quality determination process of the needle mark in the said one Embodiment. It is a figure which shows an example of the needle mark detection in the needle mark quality determination process in the said one Embodiment. It is a figure which shows another example of the needle mark detection in the needle mark quality determination process in the said one Embodiment. It is a figure which shows the maximum value and minimum value of the X coordinate of a needle mark in the said one Embodiment, and a Y coordinate. It is a figure which shows the boundary line for determining the proximity | contact degree of the area | region which the needle mark occupies in the said one embodiment, and a protection part.

Explanation of symbols

10: Computer 11: CPU
12 ... I / O interface 13 ... RAM
14 ROM
DESCRIPTION OF SYMBOLS 15 ... Disk interface 16 ... Hard disk 17 ... Internal bus 20 ... CCD camera 30 ... Light source 40 ... XY stage 90 ... Semiconductor wafer 91 ... Semiconductor chip 92 ... Electrode pad 110 ... Trigger signal generation part 120 ... XY stage control part 130 ... Image reading Unit 140 ... temporary storage unit 150 ... image trimming unit 160 ... large-capacity storage unit 170 ... needle mark inspection unit

Claims (19)

A needle mark reading device for reading a needle mark formed on the electrode pad when inspecting electrical characteristics of a predetermined object to be inspected including a plurality of electrode pads,
Illumination means for illuminating the electrode pad;
Imaging means for imaging the electrode pad illuminated by the illumination means, and outputting an image obtained by imaging as an electrical signal;
Imaging position changing means for continuously changing the imaging position to be imaged by the imaging means;
Storage means for receiving the electrical signal from the imaging means and storing the image obtained from the electrical signal;
The needle mark reading device, wherein an image of the electrode pad to be imaged is given to the imaging unit for a predetermined time in the vicinity of a time point when the electrode pad is to be imaged by the imaging unit.   The imaging position changing means can sequentially take images of all the electrode pads with a time interval equal to or longer than an imaging time for acquiring one image in the case of continuous imaging by the imaging means. The needle mark reading device according to claim 1, wherein the imaging position is changed at a predetermined moving speed.   The illumination means is a flash means that emits flash light, and the flash light is emitted for a predetermined time in the vicinity of a time point when the electrode pad is to be imaged by the imaging means, whereby the imaging means should be imaged. The needle mark reading device according to claim 1, wherein an image of the electrode pad is provided. Storage means for storing arrangement information which is data relating to the arrangement positions of the plurality of electrode pads;
Based on the arrangement information stored in the storage means, the position where the electrode pad is to be imaged is calculated by the imaging means, and the imaging position matches the position where the electrode pad is to be imaged by the imaging position changing means. The needle mark reading device according to claim 1, further comprising a trigger unit that causes the imaging unit to capture an image at the time when the image is captured. Based on the image stored in the storage means, further comprising needle mark inspection means for determining the quality of a predetermined needle mark included in the image,
The needle mark inspection means
Corresponds to a vector from the position of the needle mark as a model registered in advance in relation to a predetermined electrode pad selected from the plurality of electrode pads to the position of the needle mark formed on the predetermined electrode pad An initial vector calculating means for calculating an initial vector;
The different electrode pad within a predetermined determination range including a position separated from the position of the needle mark which is a model registered in advance in relation to an electrode pad different from the predetermined electrode pad by the direction and distance of the initial vector. The needle mark reading device according to claim 1, further comprising a needle mark quality determination unit that determines whether or not a needle mark to be formed is detected.   The needle mark inspection means determines whether or not the needle mark overlaps a predetermined area set in the vicinity of the periphery of the electrode pad including the needle mark detected by the needle mark quality determination means. The needle mark reading device according to claim 5, further comprising means.   The needle mark inspection unit generates classification header information including information for identifying each electrode pad included in the object to be inspected and a determination result of the needle mark pass / fail determination unit, and associates it with an image of the corresponding electrode pad. The needle mark reading device according to claim 5, further comprising a classification header creating means for storing the classification header information in the storage means. The initial vector calculation means includes
By calculating the difference of the image of the predetermined electrode pad that is captured in advance before the inspection of the electrical characteristics from the image stored in the storage means, the needle marks formed by the inspection of the electrical characteristics are obtained. Detecting means for detecting;
Calculation means for calculating an initial vector corresponding to a vector from the position of the needle mark as a model registered in advance in relation to the predetermined electrode pad to the position of the needle mark detected by the detection means. The needle mark reading device according to claim 5, wherein: The initial vector calculating means is formed on each electrode pad from the position of a needle mark that is a model registered in advance in association with each electrode pad of the four electrode pads located near the corner of the object to be inspected. Calculate the initial vector based on the vector up to the position of the needle mark to be performed,
The needle mark pass / fail determination means includes a predetermined determination including a position that is separated from the position of the initial vector by a direction and a distance from a position of a needle mark that is a model registered in advance in association with an electrode pad different from the four electrode pads. 6. The needle mark reading device according to claim 5, wherein it is determined whether or not a needle mark to be formed on the electrode pad is detected within a range. A needle mark inspection device for inspecting a needle mark formed on the electrode pad when inspecting electrical characteristics of a predetermined object to be inspected including a plurality of electrode pads,
Needle marks included in an image of the electrode pad obtained by imaging the electrode pad from a position of a needle mark that is a model registered in advance in association with a predetermined electrode pad selected from the plurality of electrode pads Initial vector calculation means for calculating an initial vector corresponding to the vector up to the position of
The different electrode pad within a predetermined determination range including a position separated from the position of the needle mark which is a model registered in advance in relation to an electrode pad different from the predetermined electrode pad by the direction and distance of the initial vector. A needle mark inspection apparatus comprising: needle mark quality determination means for determining whether or not a needle mark to be formed is detected. A needle mark reading method for reading a needle mark formed on the electrode pad when inspecting electrical characteristics of a predetermined object to be inspected including a plurality of electrode pads,
An illumination step of illuminating the electrode pad;
An imaging step of imaging the electrode pad illuminated in the illumination step and outputting an image obtained by imaging as an electrical signal;
An imaging position changing step for continuously changing the imaging position to be imaged in the imaging step;
Receiving the electrical signal output in the imaging step, and storing the image obtained from the electrical signal,
The needle mark reading method, wherein an image of the electrode pad to be imaged in the imaging step is provided for a predetermined time in the vicinity of a time point at which the electrode pad is to be imaged in the imaging step.   In the imaging position changing step, the images of all the electrode pads can be sequentially taken with a time interval equal to or longer than the imaging time for acquiring one image in the case of imaging continuously in the imaging step. The needle mark reading method according to claim 11, wherein the imaging position is changed at a predetermined moving speed.   In the illumination step, an image of the electrode pad to be imaged in the imaging step is provided by emitting a flash for a predetermined time in the vicinity of a time point at which the electrode pad is to be imaged in the imaging step. The needle mark reading method according to claim 11. Based on the image stored in the storage step, further includes a needle mark inspection step of determining the quality of a predetermined needle mark included in the image,
The needle mark inspection step includes
Corresponds to a vector from the position of the needle mark as a model registered in advance in relation to a predetermined electrode pad selected from the plurality of electrode pads to the position of the needle mark formed on the predetermined electrode pad An initial vector calculating step for calculating an initial vector;
The different electrode pad within a predetermined determination range including a position separated from the position of the needle mark which is a model registered in advance in relation to an electrode pad different from the predetermined electrode pad by the direction and distance of the initial vector. The needle mark reading method according to claim 11, further comprising a needle mark quality determination step for determining whether or not a needle mark to be formed is detected. A needle mark inspection method for inspecting a needle mark formed on the electrode pad when inspecting electrical characteristics of a predetermined object to be inspected including a plurality of electrode pads,
Needle marks included in an image of the electrode pad obtained by imaging the electrode pad from a position of a needle mark that is a model registered in advance in association with a predetermined electrode pad selected from the plurality of electrode pads An initial vector calculating step for calculating an initial vector corresponding to the vector up to the position of
The different electrode pad within a predetermined determination range including a position separated from the position of the needle mark which is a model registered in advance in relation to an electrode pad different from the predetermined electrode pad by the direction and distance of the initial vector. A needle mark inspection method comprising: a needle mark quality determination step for determining whether or not a needle mark to be formed is detected.   It further includes a needle mark position determination step for determining whether or not the needle mark overlaps a predetermined region set in the vicinity of the periphery of the electrode pad including the needle mark detected by the needle mark quality determination step. The needle mark inspection method according to claim 15.   Classification header information including information for identifying each electrode pad included in the object to be inspected and a determination result in the needle mark pass / fail determination step is generated, and the classification header information is associated with an image of the corresponding electrode pad and the predetermined classification header information The method for inspecting a needle mark according to claim 15, further comprising a step of creating a classification header stored in the storage means. The initial vector calculating step includes:
A detection step of detecting a needle mark formed by the inspection of the electrical characteristics by calculating a difference from the image of the predetermined electrode pad imaged in advance before the inspection of the electrical characteristics from the image;
A calculation step of calculating an initial vector corresponding to a vector from the position of the needle mark as a model registered in advance with respect to the predetermined electrode pad to the position of the needle mark detected in the detection step. The needle mark inspection method according to claim 15, wherein: In the initial vector calculating step, a pattern is formed on each electrode pad from a position of a needle mark that is a model registered in advance in association with each electrode pad of the four electrode pads positioned in the vicinity of the corner of the object to be inspected. Calculate the initial vector based on the vector up to the position of the needle mark to be performed,
In the needle mark pass / fail determination step, a predetermined determination including a position separated by a direction and a distance of the initial vector from a position of a needle mark that is a model registered in advance in association with an electrode pad different from the four electrode pads. The needle mark inspection method according to claim 15, wherein it is determined whether or not a needle mark to be formed on the electrode pad is detected within a range.

Images