Pressure-bonded ball diameter detecting apparatus and pressure-bonded ball diameter detecting method

Improving detectability of a diameter of a pressure-bonded ball bonded by a bonding apparatus by calculating the diameter of the pressure-bonded ball by obtaining a first tentative radius by subtracting a distance between a line representing an outline of a pad short side and a curving line representing an outline of a pressure-bonded ball from a distance between the line representing the outline of the pad short side and a bonding-control-center position of the pressure-bonded ball; obtaining a second tentative radius by subtracting a distance between a line representing an outline of a pad short side that faces toward the pad with which the first tentative radius is calculated and an outline of a pressure-bonded ball from a distance between the line representing the outline of the pad short side and a bonding-control-center position of the pressure-bonded ball; and averaging the same number of the first and the second tentative radii.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a pressure-bonded ball diameter detecting apparatus capable of detecting a diameter of a pressure-bonded ball bonded by a bonding apparatus and a pressure-bonded ball diameter detecting method.

2. Related Art

Wire-bonding apparatuses that connect between a pad as an electrode of a semiconductor chip and a lead as an electrode of a lead frame with a wire as a thin metal wire are widely used in a manufacturing process of semiconductor devices. Such wire-bonding apparatuses typically employ a method of sequentially bonding between a pad and a lead with a wire by forming a tip end of the wire that is inserted through a capillary and extends from a tip of the capillary into an initial ball by, for example, sparking, moving the capillary down toward the pad and pressure-bonding the initial ball to the pad using the capillary tip thereby forming a pressure-bonded ball, moving the capillary upward and then toward the lead from the pressure-bonded ball while feeding the wire from the capillary tip thereby looping the wire, moving the capillary down toward the lead and pressure-bonding the wire to the lead using the capillary tip, moving the capillary upward to cut the wire, and then moving the capillary to a position of a pad to be processed next.

In order to connect a pad and a lead in a good condition using a wire-bonding apparatus, it is necessary to make a size of a pressure-bonded ball to be a predetermined designed value. This is because a pressure-bonded ball smaller than the designed value can often result in poor bonding and a pressure-bonded ball larger than the designed value can often cause the pressure-bonded ball to protrude from the pad and to be brought into contact with an adjacent pad.

However, the size of the pressure-bonded ball can often vary during bonding due to a heating temperature of a heat block of a bonding apparatus and such. Accordingly, it is required to detect the size of the pressure-bonded ball during bonding so as to confirm that the pressure-bonded ball is bonded at a designed size. Japanese Unexamined Patent Application Publication No. H07-297220 proposes a method of detecting edges of a pressure-bonded ball based on at least three directions of lines respectively connecting a central position of a pad and points within the pad and outside the pressure-bonded ball, and calculating a position, a size, and/or a shape of the pressure-bonded ball based on the three edges of the pressure-bonded ball.

As a size of pads has increasingly become smaller along with fine-pitching of devices in recent years, there are manufactured semiconductor devices in which a diameter of a wire that extends from the pad is substantially the same as that of a pressure-bonded ball. When acquiring an image, using a camera, of a pressure-bonded ball that has been pressure-bonded to a pad of such a semiconductor chip, almost a half of a circumference of an outer shape of the pressure-bonded ball is hidden under the wire that extends from the pressure-bonded ball, and it is not possible to detect its edge by image processing.

Therefore, in bonding for fine-pitch semiconductor chips in which the diameter of the pressure-bonded ball is substantially the same as that of the wire, the method of calculating the central position and the size of the pressure-bonded ball based on the central position of the pad and the three edges of the pressure-bonded ball as proposed by Japanese Unexamined Patent Application Publication No. H07-297220 poses a problem that it is often not possible to detect the coordinates of the edges depending on a position of the pad and a position of the pressure-bonded ball as the intersection point of an X axis and a Y axis that respectively passing the center of the pad and the edges of the pressure-bonded ball are covered with the wire, and thus the size and shape of the pressure-bonded ball is often difficult to detected.

BRIEF SUMMARY OF THE INVENTION

An object of the present invention is to improve detectability of a diameter of a pressure-bonded ball bonded by a bonding apparatus.

A pressure-bonded ball diameter detecting apparatus according to the present invention includes:

a camera for capturing:an image of each of rectangle-shaped pads of each of a first pad group and a second pad group that are provided on a surface of a semiconductor chip, the first pad group including the rectangle-shaped pads arranged along a short side direction of the pads and wires each extending from a pressure-bonded ball that is bonded to each rectangle-shaped pad and across a short side of the corresponding rectangle-shaped pad, the second pad group facing toward the first pad group in a long side direction of the rectangle-shaped pads and including the rectangle-shaped pads arranged along the short side direction of the pads and wires each extending from a pressure-bonded ball that is bonded to each rectangle-shaped pad toward a direction opposite of a direction to which each wire of the first pad group extends; andan image of each pressure-bonded ball bonded to each rectangle-shaped pad of the semiconductor chip by a bonding apparatus; and

an image processing unit connected to the bonding apparatus and for processing the images captured with the camera, the image processing unit being configured to include:outline acquiring means for acquiring, from each image captured with the camera, an outline of each pressure-bonded ball and an outline of a short side of each pad, the side being opposite of a direction to which each wire extends from the corresponding pressure-bonded ball;bonding-control-center position acquiring means for acquiring, from the bonding apparatus, a bonding-control-center position of each pressure-bonded ball; andpressure-bonded ball diameter calculating means for calculating a diameter of the pressure-bonded balls by calculating first tentative radii and second tentative radii and averaging the first tentative radii and the second tentative radii of the same number, each first tentative radius being obtained by subtracting a distance in a longitudinal direction of the pads between the outline of the short side of one of the pads included in the first pad group and the outline of the corresponding pressure-bonded ball from a distance in the longitudinal direction of the pads between the outline of the short side of the pad included in the first pad group and the bonding-control-center position of the corresponding pressure-bonded ball, each second tentative radius being obtained by subtracting a distance in the longitudinal direction of the pads between the outline of the short side of one of the pads included in the second pad group and the outline of the corresponding pressure-bonded ball from a distance in the longitudinal direction of the pads between the outline of the short side of the pad included in the second pad group and the bonding-control-center position of the corresponding pressure-bonded ball.

A pressure-bonded ball diameter detecting method according to the present invention includes:

an image capturing step of capturing, using a camera, an image of each of rectangle-shaped pads of each of a first pad group and a second pad group that are provided on a surface of a semiconductor chip, the first pad group including the rectangle-shaped pads arranged along a short side direction of the pads and wires each extending from a pressure-bonded ball that is bonded to each rectangle-shaped pad and across a short side of the corresponding rectangle-shaped pad, the second pad group facing toward the first pad group in a long side direction of the rectangle-shaped pads and including the rectangle-shaped pads arranged along the short side direction of the pads and wires each extending from a pressure-bonded ball that is bonded to each rectangle-shaped pad toward a direction opposite of a direction to which each wire of the first pad group extends, and an image of each pressure-bonded ball bonded to each rectangle-shaped pad of the semiconductor chip by a bonding apparatus;

an outline acquiring step of acquiring, from each image captured with the camera, an outline of each pressure-bonded ball and an outline of a short side of each pad, the side being opposite of a direction to which each wire extends from the corresponding pressure-bonded ball;

a bonding-control-center position acquiring step of acquiring, from the bonding apparatus, a bonding-control-center position of each pressure-bonded ball; and

a pressure-bonded ball diameter calculating step of calculating a diameter of the pressure-bonded balls by calculating first tentative radii and second tentative radii and averaging the first tentative radii and the second tentative radii of the same number, each first tentative radius being obtained by subtracting a distance in a longitudinal direction of the pads between the outline of the short side of one of the pads included in the first pad group and the outline of the corresponding pressure-bonded ball from a distance in the longitudinal direction of the pads between the outline of the short side of the pad included in the first pad group and the bonding-control-center position of the corresponding pressure-bonded ball, each second tentative radius being obtained by subtracting a distance in the longitudinal direction of the pads between the outline of the short side of one of the pads included in the second pad group and the outline of the corresponding pressure-bonded ball from a distance in the longitudinal direction of the pads between the outline of the short side of the pad included in the second pad group and the bonding-control-center position of the corresponding pressure-bonded ball.

The present invention provides an advantageous effect of improving detectability of a diameter of a pressure-bonded ball bonded by a bonding apparatus.

DETAILED DESCRIPTION OF THE INVENTION

Exemplary embodiments according to the present invention will be described below with reference to the accompanying drawings. Referring toFIG. 1, a pressure-bonded ball diameter detecting apparatus30according to this exemplary embodiment is provided with a camera32that acquires an image of a pad of a fine-pitch semiconductor chip23and a pressure-bonded ball that has been bonded to the pad, an image processing unit31that processes the image acquired with the camera32, and a display unit33that is connected to the image processing unit31and displays a diameter of the pressure-bonded ball. Further, a wire-bonding apparatus10that bonds a wire to the fine-pitch semiconductor chip23to form the pressure-bonded ball on the pad by is provided with a bonding stage17that suction-fixes a substrate21to which the semiconductor chip23is mounted, a bonding arm15to which a capillary13is attached at a tip of the arm, and a bonding head12provided with a Z motor that is not shown in the drawing and that drives the bonding arm15such that the capillary13attached to the tip of the arm moves in an approaching and retreating direction with respect to the semiconductor chip23, an X-Y table11that freely moves the bonding head12in an X direction and a Y direction, and a control unit60that controls the movement of the bonding head12and the X-Y table11. The control unit60forms the wire that extends from a tip of the capillary13into an initial ball by, for example, a discharge flame off that is not shown in the drawing, sets a central position of the capillary13to be aligned with a bonding position of the pad with the X-Y table11, and drives the Z motor of the bonding head to pressure-bond the initial ball onto the pad, thereby forming the pressure-bonded ball.

The camera32is provided with an optical system including a lens and such, and an imaging area such as a CCD that converts an image formed by the optical system into electrical signals, and connected to the image processing unit31. The image processing unit31is configured by a computer including such as a CPU and a memory therein. Further, the display unit33provides a numerical display of a diameter of the pressure-bonded ball using such as an LED. The control unit60of the wire-bonding apparatus10is also configured by a computer including such as a CPU and a memory therein. The image processing unit31and the control unit60are connected via a signal circuit such as a data bus.

Referring toFIG. 2, the semiconductor chip23to which the wire is bonded by the wire-bonding apparatus10includes a first pad group100in which rectangle-shaped pads130are arranged along a short side direction of the pads and wires124each extend from a pressure-bonded ball150that is bonded to each of the rectangle-shaped pads130across a short side of the corresponding rectangle-shaped pad130, and a second pad group200in which rectangle-shaped pads230are arranged along the short side direction of the pads and wires224each extend from a pressure-bonded ball250that is bonded to each of the rectangle-shaped pads230across a short side of the corresponding rectangle-shaped pad230. The semiconductor chip23also includes a third pad group300in which rectangle-shaped pads330are arranged along a short side direction of the pads and wires324each extend from a pressure-bonded ball350that is bonded to each of the rectangle-shaped pads330across a short side of the corresponding rectangle-shaped pad330, and a fourth pad group400in which rectangle-shaped pads430are arranged along the short side direction of the pads and wires424each extend from a pressure-bonded ball450that is bonded to each of the rectangle-shaped pads430across a short side of the corresponding rectangle-shaped pad430.

The first pad group100and the second pad group200respectively include the three rectangle-shaped pads130and the three rectangle-shaped pads230that are arranged such that long sides of the rectangle-shaped pads130and230are aligned along the X direction and the short sides are aligned along the Y direction. The first pad group100and the second pad group200are disposed on a surface of the semiconductor chip on both sides in the X direction, which is a long side direction of the rectangle-shaped pads130and230, so as to face toward each other in the X direction. All of the rectangle-shaped pads130and230respectively included in the first pad group100and the second pad group200are in the same size whose length along the long side is P1and whose length along the short side is P2. The length P1along the long side corresponds to a length that allows bonding on one end and probing on the other end of the pad, and the length P2along the short side corresponds to a length that addresses the fine-pitch. Each of the wires124extending from the respective pressure-bonded balls150bonded to the rectangle-shaped pads130of the first pad group100extends toward a negative side in the X direction across the short side of the corresponding rectangle-shaped pad130on the negative side in the X direction (a left side inFIG. 2). The wire124extending from the rectangle-shaped pad130in the middle of the three pads extends substantially along the long side direction of the rectangle-shaped pad130, and each of the wires124extending from the rectangle-shaped pads130on both sides of the middle pad extends at an angle with respect to the long side direction of the rectangle-shaped pad130. Each of the wires224extending from the respective pressure-bonded balls250bonded to the rectangle-shaped pads230of the second pad group200extends toward a positive side in the X direction across the short side of the corresponding rectangle-shaped pad230on the positive side in the X direction (a right side inFIG. 2). The wire224extending from the rectangle-shaped pad230in the middle of the three pads extends substantially along the long side direction of the rectangle-shaped pad230, and each of the wires224extending from the rectangle-shaped pads230on both sides of the middle pad extends at an angle with respect to the long side direction of the rectangle-shaped pad230. In this manner, each wire124of the first pad group100and each wire224of the second pad group200extend respectively in opposite directions with respect to the X direction.

The third pad group300and the fourth pad group400respectively include the three pads330and the three pads430that are arranged such that long sides of the rectangle-shaped pads330and430are aligned along the Y direction and the short sides are aligned along the X direction. The third pad group300and the fourth pad group400are disposed on a surface of the semiconductor chip on both sides in the Y direction, which is a long side direction of the rectangle-shaped pads330and430, so as to face toward each other in the Y direction. All of the rectangle-shaped pads330and430respectively included in the third pad group300and the fourth pad group400are in the same size whose length along the long side is P1and whose length along the short side is P2, similarly to the rectangle-shaped pads130and230. Each of the wires324extending from the respective pressure-bonded balls350bonded to the rectangle-shaped pads330of the third pad group300extends toward a positive side in the Y direction across the short side of the corresponding rectangle-shaped pad330on the positive side in the Y direction. The wire324extending from the rectangle-shaped pad330in the middle of the three pads extends substantially along the long side direction of the rectangle-shaped pad330, and each of the wires324extending from the rectangle-shaped pads330on both sides of the middle pad extends at an angle with respect to the long side direction of the rectangle-shaped pad330. Each of the wires424extending from the respective pressure-bonded balls450bonded to each rectangle-shaped pads430of the fourth pad group400extends toward a negative side in the Y direction across the short side of the corresponding rectangle-shaped pad430on the negative side in the Y direction. The wire424extending from the rectangle-shaped pad430in the middle of the three pads extends substantially along the long side direction of the rectangle-shaped pad430, and each of the wires424extending from the rectangle-shaped pads430on both sides of the middle pad extends at an angle with respect to the long side direction of the rectangle-shaped pad430. In this manner, each wire324of the third pad group300and each wire424of the fourth pad group400extend respectively in opposite directions with respect to the Y direction.

The following describes detection of diameters of the pressure-bonded balls150and250in the X direction of the semiconductor chip23to which the wire bonding has been finished as shown inFIG. 2, with reference toFIG. 3A,FIG. 3B,FIG. 4A,FIG. 4B,FIG. 5A, andFIG. 5B.

The CPU of the image processing unit31adjusts a position of the camera32so that the field of view of the camera32includes the rectangle-shaped pad130of the first pad group100, and then outputs an instruction for acquiring an image. Based on this instruction, the image processing unit31acquires images of the rectangle-shaped pads130and the pressure-bonded balls150from the camera32and stores the acquired images in the memory.

Referring toFIG. 3A, each acquired image includes the rectangle-shaped pad130, the pressure-bonded ball150that pressure-bonded to the rectangle-shaped pad130, and the wire124that extends from the pressure-bonded ball150toward the negative side in the X direction. The length P2along the short side of the rectangle-shaped pad130is small as the pad is disposed at a fine-pitch, and the diameter of the pressure-bonded ball150is also small so as to be contained within the short side of the rectangle-shaped pad130. Therefore, the diameter of the pressure-bonded ball150is only slightly larger than that of the wire124, and the short side of the rectangle-shaped pad130on the negative side in the X direction across which the wire124extends in the acquired image is mostly hidden under the wire124as shown inFIG. 3A.

Further, also shown inFIG. 3A, a central point153of the pressure-bonded ball150represented as an intersection point between a center line151along the X direction and a center line152along the Y direction is slightly displaced to the positive sides both in the X direction and the Y direction from a bonding control center163represented as an intersection point between a center line161along the X direction and a center line162in the Y direction and which is a position instructed to the X-Y table11from the control unit60of the wire-bonding apparatus10.

The CPU of the image processing unit31outputs an instruction for processing the image stored in the memory and acquiring an outline of the rectangle-shaped pad130and an outline of the pressure-bonded ball150. The CPU of the image processing unit31reads image data stored in the memory, carries out such as a digitizing process, for example, thereby recognizing and acquiring the outline of the rectangle-shaped pad130as lines representing the respective sides from the two-dimensional image, and acquiring the outline of the pressure-bonded ball150as a curving line.

As shown inFIG. 4A, upon processing of the image, the four sides that define the rectangle-shaped pad130are acquired as five line segments including a line segment132between a point131and a point133, a line segment134between the point133and a point135, a line segment136between the point135and a point137, a line segment138between the point137and a point139, and a line segment140between the point139and a point141. A portion between the point131and the point141is hidden under the wire124that extends from the pressure-bonded ball150, and a height of this portion is different from that of a surface of the rectangle-shaped pad130. In the image focused on the surface of the rectangle-shaped pad130, a contrast in the portion relating to the wire124is low due to a focus error, and an outline cannot be acquired. Accordingly, it is not possible to recognize an outer line of this side by, for example, the digitizing process and a line segment for this portion is not acquired.

For the outline of the pressure-bonded ball150, it is possible to acquire the outline by, for example, digitizing a high-contrast portion in the image focused on the surface of the rectangle-shaped pad130. However, as the height of the portion for the wire124that extends from the pressure-bonded ball150is different from that of the surface of the rectangle-shaped pad130, a contrast in the portion relating to the wire124is low due to a focus error in the image focused on the surface of the rectangle-shaped pad130, and the outline cannot be acquired. Accordingly, the outline of the pressure-bonded ball150is acquired as a curving line157between a point154and a point155excluding a rising portion to the wire124as shown inFIG. 4A.

The CPU of the image processing unit31determines whether or not a line segment representing the side that extends along the Y direction and that is substantially as long as the short side of the rectangle-shaped pad130, i.e., the short side that is opposite of the side across which the wire124extends is recognized in the acquired line segments132,134,136,138, and140representing the respective sides of the rectangle-shaped pad130. If a line segment representing the side opposite of the side across which the wire124extends is not recognized in the acquired line segments, the CPU determines that it is not possible to calculate the diameter of the pressure-bonded ball150using the acquired line segments, moves the camera32to subsequent one of the rectangle-shaped pads130in the first pad group100, and repeats the operation of acquiring the image and acquiring the line segments until the line segment representing the side of the rectangle-shaped pad130opposite of the side across which the wire124extends is acquired. In this exemplary embodiment, the line segment136is the line segment representing the short side opposite of the side across which the wire124extends, and the CPU of the image processing unit31recognizes that the line segment representing the short side opposite of the side across which the wire124extends is acquired.

Then, as shown inFIG. 5A, the CPU of the image processing unit31sets a tangent line170that extends along the Y direction and is brought into contact with the curving line157representing the outline of the pressure-bonded ball150. The setting of the tangent line170can be carried out by image processing in which a line segment that extends along the Y direction is moved in the X direction, and acquiring a line segment that passes through a point156where a number of intersection points between the line segment and the curving line157is reduced from two to one as the tangent line170. Alternatively, it is possible to obtain the tangent line170by setting an approximate circular arc that represents the curving line assuming that the curving line157is a circular arc representing the outline of the pressure-bonded ball150, and obtaining a line that passes the point156that is brought into contact with the approximate circular arc by calculation.

When the tangent line170is set, the CPU of the image processing unit31acquires a distance between the tangent line170and the line segment136as a distance Gx1between the outline of the pressure-bonded ball150and the outline of the short side of the rectangle-shaped pad130opposite of the side across which the wire124extends, and stores the distance Gx1in the memory.

The CPU of the image processing unit31acquires the position of the bonding control center163of the rectangle-shaped pad130that is being processed from the control unit60of the wire-bonding apparatus10. The bonding control center163is acquired as numbers of pixels between the bonding control center163and the center of the acquired image both in the X direction and the Y direction. Then, the CPU of the image processing unit31acquires a distance Lx1between the bonding control center163and the line segment136by acquiring numbers of pixels between the bonding control center163and the line segment136. The distance Lx1is a distance between the position of the bonding control center163and the outline of the short side of the rectangle-shaped pad130opposite of the side across which the wire124extends. Then, the CPU of the image processing unit31calculates a first tentative radius ra1by subtracting the distance Gx1from the distance the Lx1. As shown inFIG. 5A, the first tentative radius ra1is a value acquired by adding an amount of displacement δ1in the X direction between the central point153of the pressure-bonded ball150and the position of the bonding control center163to a radius of the pressure-bonded ball150.

The image processing unit31repeats the operation as described above, and acquires a predetermined number of the first tentative radii ra1from the first pad group100and stores the first tentative radii ra1in the memory.

The image processing unit31acquires a second tentative radius ra2from the second pad group200in the same manner as in the acquiring of the first tentative radius ra1from the first pad group100. The second tentative radius ra2is acquired from the second pad group200by the same method as previously described with reference toFIG. 3A,FIG. 4A, andFIG. 5A, and reference numerals for the rectangle-shaped pads, the points, and the line segments included in the second pad group200are read in the 200s as shown inFIG. 3B,FIG. 4B, andFIG. 5B.

As shown inFIG. 5B, when a tangent line270is set, similarly to the case of the first pad group100, the CPU of the image processing unit31acquires a distance between the tangent line270and a line segment236as a distance Gx2between the outline of the pressure-bonded ball250and the outline of the short side of the rectangle-shaped pad230opposite of the side across which the wire224extends, and stores the distance Gx2in the memory.

The CPU of the image processing unit31acquires a position of a bonding control center263of the rectangle-shaped pad230that is being processed from the control unit60of the wire-bonding apparatus10, and acquires a distance Lx2between the bonding control center263and the line segment236. The distance Lx2is a distance between the position of the bonding control center263and the outline of the short side of the rectangle-shaped pad230opposite of the side across which the wire224extends. Then, the CPU of the image processing unit31calculates the second tentative radius ra2by subtracting the distance Gx2from the distance Lx2. As shown inFIG. 5B, the second tentative radius ra2is a value acquired by subtracting an amount of displacement δ2in the X direction between a central point253of the pressure-bonded ball250and the position of the bonding control center263from a radius of the pressure-bonded ball250.

The image processing unit31, similarly to the case of the first pad group100, acquires a predetermined number of the second tentative radii ra2from the second pad group200and stores the second tentative radii ra2in the memory.

The CPU of the image processing unit31reads the first tentative radii ra1and the second tentative radii ra2of the same number from the memory and calculates an average of these values. The first tentative radius ra1is a value acquired by adding an amount of displacement δ1in the X direction between the central point153of the pressure-bonded ball150and the position of the bonding control center163to a radius of the pressure-bonded ball150, and the second tentative radius ra2is a value acquired by subtracting an amount of displacement δ2in the X direction between a central point253of the pressure-bonded ball250and the position of the bonding control center263from a radius of the pressure-bonded ball250. In the wire-bonding apparatus10, as the amount of displacement5is substantially the same as the amount of displacement δ2, calculating the average of the first tentative radii ra1and the second tentative radii ra1of the same number can offset the amount of displacement5and the amount of displacement δ2, and whereby an average radius of the pressure-bonded balls150and250in the X direction is obtained. Then, the image processing unit31doubles the obtained average radius of the pressure-bonded balls150and250in the X direction, and displays the doubled value on the display unit33of the pressure-bonded ball diameter detecting apparatus30as a diameter of the pressure-bonded balls150and250in the X direction.

In the same manner as described above, the image processing unit31obtains an average radius of the pressure-bonded balls350and450in the Y direction from the third pad group300and the fourth pad group400, doubles the obtained average radius, and displays the doubled value in the display unit33as a diameter in the Y direction.

According to the exemplary embodiment as described above, it is possible to obtain the average diameter of the pressure-bonded balls150-450based on the distances respectively between the short sides of the rectangle-shaped pads130-430opposite of the sides across which the wires124-424extend and the outlines of the pressure-bonded balls150-450as well as the distances respectively between the bonding control centers163-463and the short sides of the rectangle-shaped pads130-430opposite of the sides across which the wires124-424extend, without obtaining the central positions of the pressure-bonded balls150-450. Therefore, the exemplary embodiment described above provides an advantageous effect of improving detectability of the diameters of the pressure-bonded balls150-450in bonding for fine-pitch semiconductor in which the diameters of the pressure-bonded balls150-450are substantially the same as those of the wires124-424.

According to the exemplary embodiment described above, the pressure-bonded ball diameter detecting apparatus30includes the camera32that is separately provided. However, it is possible to use a camera provided for the wire-bonding apparatus10as the camera32. Further, according to the exemplary embodiment described above, an image of each rectangle-shaped pad and each pressure-bonded ball is sequentially taken and the first tentative radius ra1and the second tentative radius ra2are obtained. However, it is possible to acquire an image of the plurality of rectangle-shaped pads130and230and the pressure-bonded balls150and250included in the first pad group100and the second pad group200, carry out the image processing at the same time, for example, and calculate the first tentative radius ra1and the second tentative radius ra2.

The above exemplary embodiment describes the detection of the diameter of the pressure-bonded ball formed by the wire-bonding apparatus10. However, the present invention can be applied to detection of a diameter of a pressure-bonded ball formed by any type of bonding apparatuses such as a bump bonding apparatus, in addition to the pressure-bonded ball formed by the wire-bonding apparatus10.