JP3340114B2 - Inspection equipment for semiconductor devices and component mounting machines - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inspection apparatus for a semiconductor device for inspecting a position shift of a tip of an external connection terminal formed on a semiconductor device, and a component mounting machine having the same.

[0002]

2. Description of the Related Art Conventionally, for detecting a bending of a pin of a pin grid array having an external connection terminal of a semiconductor device, particularly a pin-shaped external connection terminal having a high possibility of bending, a surface on which the external connection terminal of the semiconductor device is formed. Is irradiated with light from a ring-shaped light source, and a flat image of the surface on which the external connection terminal is formed is captured by a TV camera in a state where the shadow of the external connection terminal is made as thin as possible. Then, the plane image is subjected to image processing based on the luminance difference, the area of the tip of the external connection terminal that shines brightly is specified, and the position of the center of gravity of the specified area is determined, so that the two-dimensional plane of the tip of the external connection terminal is obtained Measure the position at. The position of the tip of the external connection terminal is inspected by determining whether the measured position of the tip of the external connection terminal is within a predetermined reference area, and whether the pin is bent. The method of detecting whether or not it is used was adopted.

[0003]

However, the above-mentioned inspection method is intended for a linear pin having an external connection terminal standing upright at a right angle to the electrode pad. As shown in FIG. 1, a metal wire 12 whose middle part is bent to the side of the electrode pad 10 and is formed in a crank shape as shown in FIG. 1 is erected on the electrode pad 10. The external connection terminals 14 are not considered as inspection targets.

[0004] Such a crank-shaped external connection terminal 14
In the semiconductor device having the external connection terminal 14, when the planar image of the external connection terminal 14 is captured, even if the external connection terminal 14 has no abnormality such as bending, the electrode pad 10 and the external connection terminal 1
4 is different from the conventional external connection terminal in that the position of the tip A is shifted. For this reason, when the conventional ring-shaped illumination 18 is used, the bright spot B of the electrode pad 10 and the bright spot C of the front end A are located close to each other as shown in FIG. Under such circumstances, it is difficult to identify the position of the distal end A of the external connection terminal 14 while distinguishing between the bright point B of the electrode pad 10 and the bright point C of the distal end A. There is a problem that it is difficult to inspect the position of the portion A accurately.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to solve the above-mentioned problem, and an object of the present invention is to provide a semiconductor device capable of accurately detecting a positional deviation of a tip of an external connection terminal formed of a metal wire bent in a crank shape. An object of the present invention is to provide a device inspection device and a component mounting machine having the same.

[0006]

According to the present invention, there is provided an inspection apparatus for a semiconductor device, comprising:
An irradiation unit that irradiates light to the surface of the semiconductor device on which the external connection terminals are formed, an imaging unit that captures a planar image of the surface on which the external connection terminals are formed using an optical system, and an imaging unit that is obtained by the imaging unit. An inspection unit for inspecting a positional shift of a tip of the external connection terminal based on the image data obtained, wherein the external connection terminal is provided upright on an electrode pad, and an intermediate portion is provided. The irradiation unit is formed of a metal wire formed in a crank shape by being bent to the side of the electrode pad.
Light is applied to a surface on which the external connection terminal is formed from a direction opposite to a bending direction of the halfway portion.

According to this, generally, a metal wire is connected to an electrode pad by ball bonding of a gold wire. Therefore, the surface shape of the electrode pad is a hemispherical surface with a bulged center, and the surface for forming external connection terminals is formed. The portion that shines upon receiving the light applied to the external connection terminal becomes a hemisphere in a direction opposite to the bending direction of the middle portion of the external connection terminal. On the other hand, the opposite hemispherical surface is not illuminated and does not shine. For this reason, the bright spot by the electrode pad has a substantially half-moon shape in which the bright spot side at the tip of the external connection terminal is darkened, and the entire bright spot formed by the conventional electrode is circularly shaped by the conventional ring illumination. The distance between the luminescent spot of the electrode pad and the luminescent spot at the tip of the external connection terminal is wider than in the case described above. For this reason, the process of specifying the position of the tip of the external connection terminal by distinguishing the bright point of the electrode pad from the bright point of the tip of the external connection terminal becomes easy to perform, and it becomes possible to perform an accurate positional displacement inspection.

The optical system is characterized in that it is a telecentric optical system in which an aperture stop is arranged on a focal plane in a back image space. By using a telecentric optical system to capture the image on the external connection terminal side with substantially parallel light, errors in the peripheral portion due to fluctuations in the height of the semiconductor device to be inspected (height of the measuring section) are eliminated (angle of view) Parallax is lost). Thus, it is possible to perform a highly accurate positional deviation inspection of the tip of the external connection terminal. Further, the imaging unit is arranged at a position outside a region where illumination light from the illumination unit is specularly reflected by a surface of the semiconductor element on which an external connection terminal is formed. Thus, the reflected light from the distal end of the external connection terminal can be reliably detected by the imaging unit, and a highly accurate positional displacement inspection of the distal end of the external connection terminal can be performed.

According to a third aspect of the present invention, there is provided a component mounter provided with a holding head for holding and releasing a semiconductor device, a head moving mechanism for moving the holding head three-dimensionally, and an inspection position. Or the semiconductor device inspection apparatus according to claim 2, wherein the holding head controls the holding / opening of the semiconductor device by the holding head and the head moving mechanism controls the movement of the holding head, and the semiconductor device is held by the holding head. A control unit that moves the device to a test position, controls the semiconductor device test device, and tests a position shift of a tip of an external connection terminal of the semiconductor device.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a semiconductor device inspection apparatus and a component mounter using the same according to the present invention will be described below with reference to the accompanying drawings. First,
FIGS. 1 and 2 show the configuration of a semiconductor device to be inspected.
This will be described with reference to FIG. External connection terminal 14 of semiconductor device 16
Is formed on a metal wire 12 which is erected on the electrode pad 10, and has a halfway portion bent to the side of the electrode pad 10 (to the right in FIGS. 1 and 2) and formed in a crank shape, and has a spring property. Present. The method of forming the external connection terminal 14 is as follows. The metal wire 12 is formed on the electrode pad 10 formed in advance on the external connection terminal formation surface 16a of the semiconductor device 16 by using a capillary.
After the thin gold wire is ball-bonded and then raised upward, it is once bent to the side of the electrode pad 10 (in other words, to the side of the raised portion),
Then, after being raised up again, discharge cutting is performed to form the entire shape into a crank shape (also referred to as a horizontal Z shape). Then, due to the structure fixed by ball bonding, the surface shape of the root portion 12a of the metal wire 12 connected to the electrode pad 10 has a hemispherical shape with a raised central portion.

For this reason, a general PGA (Pin grid a)
rray) Unlike the case where a rigid pin, which is manufactured to a predetermined length in advance, such as a board, is attached to the board, the gold wire must be bent and manufactured. There is a high possibility that the tip of the external connection terminal 14 is displaced in the vertical direction or the horizontal direction, for example, because there is a possibility that a slight variation may occur in the time required until the wire is cut. In addition, since the strength of the external connection terminal 14 is extremely lower than that of the pins of the PGA substrate, the external connection terminal 14 is easily bent if the handling is poor during transportation or the like. There is a high possibility that the position will shift in the direction or the left and right direction.

Therefore, after the external connection terminals 14 are formed, the manufacturer views the formation surface 16a of the external connection terminals 14 of the semiconductor device 16 from the front and places the tip of each external connection terminal 14 at a predetermined position. It is necessary to inspect whether or not the part A is located before shipping. Similarly, at the supply destination, it is necessary to confirm the position of the distal end portion A of the external connection terminal 14 again before mounting the semiconductor device 16 having the external connection terminal 14 formed thereon on a substrate. . Therefore, a semiconductor device inspection device and a component mounting machine incorporating the inspection device are required.

Next, the structure and operation of the semiconductor device inspection apparatus 20 will be described with reference to FIGS.
The irradiation unit 22 emits light to the surface (formation surface) 16 a of the semiconductor device 16 on which the external connection terminals 14 are formed, and emits light to the electrode pads 10.
Irradiation is performed only from the direction opposite to the sideward bending direction of the halfway portion of the external connection terminal 14 with reference to FIG. 5 and not from directly above, but obliquely from the side (see FIG. 5).
The irradiating unit 22 is not a point light source but uses a linear or planar light source in which light rays are close to parallel light.
It is preferable that the light is irradiated on all of the plurality of external connection terminals 14 erected on the formation surface 16a of the camera under the above-mentioned condition, and the plane image is taken in by an imaging unit described later. It is also effective in view of cost to use a widely used and inexpensive ring-shaped illumination, and to arrange a light shielding plate on a part of the illumination so that light can be emitted from one direction, thereby forming the irradiation unit 22. It is. Further, it is possible to adopt a configuration in which the parallel light can be emitted even when the LEDs are arranged in a plane.

Here, instead of the conventional structure in which light is applied from the peripheral circumference using the ring-shaped illumination, the operation is achieved by applying light to the formation surface 16a in one direction and obliquely laterally.
The effect will be described with reference to FIGS. As already described, the surface 16a of the semiconductor device 16 on which the external connection terminal 14 is formed as shown in FIG.
When light is applied from all directions using a ring-shaped illumination or the like, the tip A of the external connection terminal 14 shines and the external connection terminal 1 formed on the surface of the electrode pad 10.
The base portion 12a of FIG. 4 also has a hemispherical shape with a raised central portion, so that it shines over the entire surface.
As shown in (b), the shining area is circular. As a result,
Since the relatively wide circular bright spot B is generated close to the bright spot C generated by the front end A of the external connection terminal 14, the bright spot C generated by the front end A of the external connection terminal 14 is separated and detected. This makes it difficult to detect the position of the distal end portion A with high accuracy. As a result, the accuracy of the position shift inspection is reduced, and a test that can be used practically cannot be performed.

On the other hand, as shown in FIG. 5A, the external connection terminals 16 of the semiconductor device 16 are formed on the surface 16a on which the external connection terminals 14 are formed, obliquely from the horizontal direction and in a certain direction. When light is irradiated only from the direction opposite to the bending direction of the terminal 14, the surface of the electrode pad 10 having a hemispherical surface, more specifically, the surface of the base portion 12 a of the metal wire 12 serving as the external connection terminal 14, on the irradiation side Light hits the hemisphere, but does not hit the opposite hemisphere. Therefore, the shape of the luminescent spot B of the electrode pad 10 becomes a substantially half-moon shape in which the luminescent spot C side of the tip end portion A of the external connection terminal 14 becomes dark as shown in FIG. Than when the shape of the luminescent spot B of the electrode pad 10 is circular,
The distance L between the bright spot B of the electrode pad 10 and the bright spot C of the tip A of the external connection terminal 14 increases. For this reason, since the bright spot C of the tip A of the external connection terminal 14 can be easily and reliably separated in the image processing, the inspection process for specifying the position of the tip A of the external connection terminal 14 can be easily performed. This makes it possible to perform an accurate positional displacement inspection.

When the density of the external connection terminals 14 erected on the formation surface 16a is high, a plurality of formation surfaces 16a are formed instead of taking in a flat image of the entire formation surface 16a at a time and performing image processing. It is also conceivable to divide the image into a region having a predetermined area, capture an image in units of the divided region, and perform image processing. In this case, a parallel light is applied to the external connection terminal 14 in one region serving as a processing unit. Any structure that can irradiate light in a state close to is possible, and the size of the irradiation unit 22 and the imaging unit can be reduced. When the illumination unit 22 illuminates the formation surface 16a of the external connection terminal 14 of the semiconductor device 16, an LED having high directivity of light is used as a light source, or illumination light is illuminated as parallel light using a cylindrical lens. By doing so, light is likely to be reflected only from the tip of the external connection terminal 14, and the imaging unit 24 can accurately inspect the position shift of the tip of the external connection terminal 14.

The imaging section 24 uses an optical system 26 to convert a planar image of the formation surface 16a of the external connection terminal 14 into a camera (CC).
D camera 28). In order to accurately inspect the position of the distal end portion A of the external connection terminal 14, it is necessary to capture the planar image in a state in which the peripheral portion has little distortion.
Therefore, the aperture stop is constituted by a telecentric optical system in which the aperture stop is arranged on the focal plane in the back image space, which is disclosed in Japanese Patent Application Laid-Open No. 7-325036, and the apparatus is downsized. In the telecentric optical system, all principal rays in the object space are parallel to the axis, so that the image around the lens has less distortion. Therefore, even with a small-diameter lens, it is possible to inspect the positional deviation of the tip A of the external connection terminal 14 with high accuracy. Further, the imaging unit 24 has a function of performing a binarization process so that the captured image data can be digitally processed and inspected by an inspection unit described later, and a function of performing a differentiation process in order to enhance recognition accuracy. An image processing unit 30 is provided. The image processing unit 30 may be configured separately from the imaging unit 24.

The system control unit 32 has a function as an inspection unit. Based on image data of a plane image obtained by the imaging unit 24, the system control unit 32 detects a positional shift of the tip A of each external connection terminal 14 by pattern matching or the like. It has the function of inspecting using the method described above. Thereby, it is possible to inspect the external connection terminal 14 in which the distal end portion A is displaced from the regular position. Further, the system control unit 32 controls the light intensity of the irradiation unit 22 by:
It is also possible to automatically control the captured image data to be appropriate. The data storage unit 34 stores reference data for pattern matching and the like in advance.

The semiconductor device 1 according to the present embodiment
In the case where the surface 16a of the external connection terminal 14 is irradiated with light from an oblique lateral direction opposite to the bending direction of the external connection terminal 14, the position of the distal end of the external connection terminal 14 is inspected. Of the reflected light from the formation surface 16a of the external connection terminal 14 of the semiconductor device 16 so that the reflected light is not incident on the imaging unit 24, so that processing of image data captured by the imaging unit 24 can be performed. This can be performed with high accuracy, and the positional displacement of the external connection terminal 14 can be accurately inspected. FIG. 7 shows the imaging unit 2 with the optical axis perpendicular to the surface 16 a of the semiconductor device 16 where the external connection terminals 14 are formed.
In the case where the optical system 26 and the camera 28 of FIG.
°. As shown in the drawing, the imaging unit 24 is arranged at a predetermined distance from the surface 16a of the semiconductor device 16 on which the external connection terminals 14 are formed, so that the imaging unit 24 is specularly reflected on the surface 16a of the semiconductor device 16 where the external connection terminals 14 are formed. The reflected light and the reflected light from the part bent substantially parallel to the surface 16a on which the metal wire 12 is formed do not enter the imaging unit 24, and the displacement of the external connection terminal 14 can be accurately inspected.

The optical system 26 and the camera 28 detect the positional shift of the external connection terminal 14 by focusing on the tip of the external connection terminal 14. For this reason,
The reflected light from the semiconductor device 16 and the metal wire 12 appears on the background of the visual field. A large number of external connection terminals 14 are arranged close to each other, and since the outer surface is a curved surface, reflected light from the external connection terminals 14, particularly, reflected light from a portion of the metal wire 12 bent parallel to the forming surface 16 a. Influence cannot be ignored. Therefore, the arrangement in which the reflected light from the formation surface 16 a of the external connection terminal 14 of the semiconductor device 16 and the bent portion of the metal wire 12 does not enter the imaging unit 24 can accurately correct the displacement of the tip of the external connection terminal 14. It is effective in enabling inspection. FIG. 8 illustrates the optical system 2 of the imaging unit 24.
In this example, the optical axes of the camera 6 and the camera 28 are inclined from a direction perpendicular to the surface 16a of the semiconductor device 16 on which the external connection terminals 14 are formed. When the optical system 26a and the camera 28a are arranged in the direction of the light reflected specularly on the surface 16a on which the terminal 14 is formed, as described above, the surrounding light is more reflected than the light reflected from the tip of the external connection terminal 14. Reflected light becomes stronger,
It becomes difficult to accurately inspect the position shift of the external connection terminal 14. Also in this case, accurate inspection becomes possible by arranging the optical system 26 and the camera 28 at positions where reflected light from the formation surface 16 of the external connection terminals 14 of the semiconductor device 16 does not enter.

Next, the semiconductor device inspection apparatus 20 described above is used.
FIG. 4 shows the configuration and outline operation of the component mounter 36 using
And FIG. The holding head 38 is configured to freely hold and open the semiconductor device 16 by a technique such as suction. The component mounter 36 may mount electronic components other than the semiconductor device 16 in such a case. In this case, the holding head 38 is configured to hold other electronic components. The holding head 38 includes a head moving mechanism 40
The semiconductor device 16 is three-dimensionally moved, and is rotated so that the direction of the semiconductor device 16 held by suction can be changed. Then, the suction / release control of the holding head 38 and the drive control of the head moving mechanism 40 are performed by the head control unit 42.

The component mounter 36 includes the semiconductor device 1
A transport line 46 for transporting a substrate 44 on which electronic components including the semiconductor device 6 are mounted;
8 and other small electronic components for tape feeder 50
A component supply unit 52 to which is mounted is provided. Also,
The above-described semiconductor device inspection device 20 for detecting the positional deviation of the tip A of the external connection terminal 14 of the semiconductor device 16 held by the holding head 38 is also provided between the transport line 46 and the component supply unit 52. I have. In the case where the semiconductor device inspection device 20 is an inspection device dedicated to the semiconductor device 16 having the external connection terminal 14 having the crank shape, and there is another electronic component to be inspected, The inspection device for electronic components is, for example, a semiconductor device inspection device 2
0. Inspection device 20 for semiconductor device
May be switched to ring-shaped illumination, and may be used for inspection of other electronic components.

In the component mounter 36 of the present embodiment, as an example, the system controller 32 of the semiconductor device inspection apparatus 20 also controls the head controller 42, and the head controller 42 sucks the holding head 38. Controlling the opening operation and the moving operation of the holding head 38; Therefore, the system control unit 32 functions as a control unit in the component mounter 36. With the configuration described above, the holding head 38 is connected to the component supply unit 5.
2, the electronic component is sucked, and the electronic component is
When the external connection terminal 14 is the semiconductor device 16 formed in a crank shape, the external connection terminal 14 is transported to the inspection position E where the semiconductor device inspection device 20 is arranged, and the positional deviation of the tip A of the external connection terminal 14 is inspected. Is done. When the inspection result is good, the holding head 38 moves to the mounting position of the semiconductor device 16 on the substrate 44 and mounts the semiconductor device 16 at a predetermined mounting position. Thereafter, the suction is released, and the operation shifts to the mounting operation of the next electronic component. The external connection terminal 1
If the inspection result of the positional deviation of the leading end portion A of No. 4 is bad, the semiconductor device 16 is transported to a disposal position (not shown), opened, and held for the next new semiconductor device 16. Move to the component supply unit 52.

Further, the semiconductor device inspection apparatus 20 has a configuration for inspecting the positional deviation of the distal end portion A in a two-dimensional plane parallel to the formation surface 16a of the external connection terminal 14, and also has the object of the optical system 26. The depth is appropriately limited, only the vicinity of the distal end A of the external connection terminal 14 at the regular height enters the subject depth, and other images are blurred. When you move out of depth,
By utilizing the fact that the area of the bright spot at the tip end portion A changes (increases), it is also possible to adopt a configuration in which the displacement in the vertical direction is also inspected.

[0025]

According to the semiconductor device inspection apparatus and the component mounter according to the present invention, the semiconductor device having the external connection terminal formed of a metal wire whose middle part is bent in a crank shape can be used as the external connection terminal. There is an effect that the displacement of the tip can be accurately inspected.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a main part for describing a structure of an external connection terminal of a semiconductor device to be inspected by a semiconductor device inspection apparatus according to the present invention.

FIG. 2 is a plan view of FIG.

FIG. 3A is a conventional semiconductor device inspection apparatus, and FIG.
FIG. 4 is an explanatory view for explaining a method of inspecting external connection terminals of the semiconductor device of FIG. 1, and FIG. 4B is an explanatory view showing a plane image of a formation surface of external connection terminals to be taken in;

FIG. 4 is a block diagram illustrating a configuration of a semiconductor device inspection apparatus according to the present invention and a component mounter using the same.

5A is an explanatory diagram illustrating a method of inspecting an external connection terminal of the semiconductor device of FIG. 1 in the inspection device for a semiconductor device according to the present embodiment, and FIG. FIG. 5 is an explanatory diagram showing a planar image of a formation surface of a.

FIG. 6 is a plan view illustrating the configuration of the component mounter of FIG. 4;

FIG. 7 is an explanatory diagram showing a method for inspecting an external connection terminal in the semiconductor device inspection apparatus of the present embodiment.

FIG. 8 is an explanatory diagram showing another method of inspecting external connection terminals in the semiconductor device inspection apparatus of the present embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Electrode pad 14 External connection terminal 16 Semiconductor device 16a Forming surface of external connection terminal 20 Inspection device for semiconductor device 22 Irradiation unit 24 Imaging unit 26 Optical system 32 System control unit

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-9-178445 (JP, A) JP-A-7-86320 (JP, A) JP-A-3-278600 (JP, A) Table 2001-513594 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H05K 13/08 H05K 13/04

Claims (4)

(57) [Claims] An irradiation unit that irradiates light to a surface of the semiconductor device on which the external connection terminals are formed; an imaging unit that captures a planar image of a surface on which the external connection terminals are formed using an optical system; An inspection device for a semiconductor device, comprising: an inspection unit configured to inspect a positional shift of a tip of the external connection terminal based on image data obtained by an imaging unit; wherein the external connection terminal is provided upright on an electrode pad. An intermediate portion is formed of a metal wire formed in a crank shape by being bent to the side of the electrode pad; and the irradiating portion is formed on a surface on which the external connection terminal is formed, in a direction opposite to a bending direction of the intermediate portion. An inspection device for semiconductor devices, wherein light is emitted from the device. 2. The inspection apparatus for a semiconductor device according to claim 1, wherein said optical system is a telecentric optical system in which an aperture stop is arranged on a focal plane in a back image space. 3. The imaging device according to claim 1, wherein the imaging unit is arranged at a position outside a region where illumination light from the illumination unit is specularly reflected by a surface of the semiconductor element on which an external connection terminal is formed. The inspection device for a semiconductor device according to claim 1. 4. The inspection for a semiconductor device according to claim 1, wherein the holding head holds and releases the semiconductor device, a head moving mechanism that moves the holding head three-dimensionally, and the inspection device is provided at an inspection position. The apparatus performs holding / opening control of the semiconductor device by the holding head and movement control of the holding head by the head moving mechanism, holds the semiconductor device by the holding head and moves the semiconductor device to an inspection position, A component mounting machine, comprising: a control unit that controls the semiconductor device inspection device to inspect a position shift of a tip end of an external connection terminal of the semiconductor device.