WIRE SHAPE MEASUREMENT DEVICE, WIRE THREE-DIMENSIONAL IMAGE GENERATION METHOD, AND WIRE SHAPE MEASUREMENT METHOD

Abstract

Provided is a wire shape measurement device of a semiconductor device comprising a substrate, a semiconductor element, and a wire connecting an electrode of the semiconductor element to an electrode of the substrate. The wire shape measurement device comprises: cameras that capture two-dimensional images of the semiconductor device; and a control unit that examines the shape of the wire based on the two-dimensional images of the semiconductor device acquired by the cameras. The control unit performs pattern matching using information on the position at which the wire is connected to the substrate or the semiconductor element and thickness information of the wire, and by utilizing the pattern matching, the control unit: generates a three-dimensional image of the wire from the two-dimensional images of the semiconductor device acquired by the cameras; and performs shape measurement of the wire based on the generated three-dimensional image of the wire.

Claims

1. A wire shape measurement device for a semiconductor device, which comprises: a substrate; a semiconductor element mounted on the substrate; and a wire connecting an electrode of the semiconductor element and an electrode of the substrate, or connecting one electrode of the semiconductor element and another electrode of the semiconductor element, the wire shape measurement device comprising: a plurality of cameras capturing two-dimensional images of the semiconductor device; and a control unit measuring a shape of the wire based on the two-dimensional images of the semiconductor device acquired by the cameras, wherein the control unit: respectively captures the two-dimensional images of the semiconductor device with the plurality of cameras, sets two-dimensional coordinate detection regions at predetermined intervals in a region that connects a start point and a terminal point of connection of the wire with the substrate or the semiconductor element in each of the two-dimensional images, searches the two-dimensional coordinate detection regions for a linear image corresponding to a diameter of the wire by pattern matching that superimposes a reference pattern and a detected image, repeats a plurality of times an operation of taking a center position of the linear image corresponding to the diameter of the wire as two-dimensional coordinates of the wire in the two-dimensional coordinate detection region, and respectively extracts two-dimensional coordinates corresponding to a portion of the wire from the two-dimensional images of the semiconductor device acquired by the cameras, calculates respective three-dimensional coordinates of a plurality of portions of the wire based on the two-dimensional coordinates respectively extracted and a position of each of the cameras, generates a three-dimensional image of the wire based on the three-dimensional coordinates calculated, and measures the shape of the wire based on the three-dimensional image of the wire generated.

2. (canceled)

3. (canceled)

4. The wire shape measurement device according to claim 1, wherein the cameras are respectively arranged on both sides of the wire so that optical axes of the cameras intersect a direction in which the wire extends.

5. The wire shape measurement device according to claim 1, wherein the control unit inspects the shape of the wire based on the three-dimensional image of the wire generated.

6. The wire shape measurement device according to claim 5, wherein the control unit inspects the shape of the wire by comparing the three-dimensional image of the wire generated with a reference shape of the wire.

7. The wire shape measurement device according to claim 6, wherein the control unit: extracts a shape parameter of the wire from the three-dimensional image of the wire generated, and inspects the shape of the wire by comparing the shape parameter extracted with a reference value of the shape parameter.

8. A wire three-dimensional image generation method for a semiconductor device, which comprises: a substrate; a semiconductor element mounted on the substrate; and a wire connecting an electrode of the semiconductor element and an electrode of the substrate, or connecting one electrode of the semiconductor element and another electrode of the semiconductor element, the wire three-dimensional image generation method comprising: an image capturing step of respectively capturing two-dimensional images of the semiconductor device with a plurality of cameras; a two-dimensional coordinate extraction step of setting two-dimensional coordinate detection regions at predetermined intervals in a region that connects a start point and a terminal point of connection of the wire with the substrate or the semiconductor element in each of the two-dimensional images, searching the two-dimensional coordinate detection regions for a linear image corresponding to a diameter of the wire by pattern matching that superimposes a reference pattern and a detected image, repeating a plurality of times an operation of taking a center position of the linear image corresponding to the diameter of the wire as two-dimensional coordinates of the wire in the two-dimensional coordinate detection region, and respectively extracting two-dimensional coordinates corresponding to a portion of the wire from the two-dimensional images of the semiconductor device acquired by the cameras; a three-dimensional coordinate calculation step of calculating respective three-dimensional coordinates of a plurality of portions of the wire based on the two-dimensional coordinates respectively extracted and a position of each of the cameras; and a three-dimensional image generation step of generating a three-dimensional image of the wire based on the three-dimensional coordinates calculated.

9. (canceled)

10. (canceled)

11. A wire shape measurement method for a semiconductor device, which comprises: a substrate; a semiconductor element mounted on the substrate; and a wire connecting an electrode of the semiconductor element and an electrode of the substrate, or connecting one electrode of the semiconductor element and another electrode of the semiconductor element, the wire shape measurement method comprising: an image capturing step of respectively capturing two-dimensional images of the semiconductor device with a plurality of cameras; a two-dimensional coordinate extraction step of setting two-dimensional coordinate detection regions at predetermined intervals in a region that connects a start point and a terminal point of connection of the wire with the substrate or the semiconductor element in each of the two-dimensional images, searching the two-dimensional coordinate detection regions for a linear image corresponding to a diameter of the wire by pattern matching that superimposes a reference pattern and a detected image, repeating a plurality of times an operation of taking a center position of the linear image corresponding to the diameter of the wire as two-dimensional coordinates of the wire in the two-dimensional coordinate detection region, and respectively extracting two-dimensional coordinates corresponding to a portion of the wire from the two-dimensional images of the semiconductor device acquired by the cameras; a three-dimensional coordinate calculation step of calculating respective three-dimensional coordinates of a plurality of portions of the wire based on the two-dimensional coordinates respectively extracted and a position of each of the cameras; a three-dimensional image generation step of generating a three-dimensional image of the wire based on the three-dimensional coordinates calculated; and a measurement step of measuring a shape of the wire based on the three-dimensional image of the wire generated.

12. The wire shape measurement method according to claim 11, comprising an inspection step of inspecting the shape of the wire based on the three-dimensional image of the wire generated.

13. The wire shape measurement method according to claim 12, wherein the inspection step inspects the shape of the wire by comparing the three-dimensional image of the wire generated with a reference shape of the wire.

14. The wire shape measurement method according to claim 13, wherein the inspection step extracts a shape parameter of the wire from the three-dimensional image of the wire generated, and inspects the shape of the wire by comparing the shape parameter extracted with a reference value of the shape parameter.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] FIG. 1 is an elevational view showing the wire shape measurement device according to the embodiment.

[0027] FIG. 2 is a plan view showing the wire shape measurement device according to the embodiment.

[0028] FIG. 3 is a flowchart showing an operation of the wire shape measurement device according to the embodiment.

[0029] FIG. 4 is a perspective view showing an arrangement of a wire and cameras of the wire shape measurement device according to the embodiment.

[0030] FIG. 5 is an explanatory view showing a two-dimensional image acquired by imaging a wire with a camera arranged on the Y-direction plus side of the semiconductor device of the wire shape measurement device according to the embodiment.

[0031] FIG. 6 is an explanatory view showing a two-dimensional image acquired by imaging a wire with a camera arranged on the Y-direction minus side of the semiconductor device of the wire shape measurement device according to the embodiment.

DESCRIPTION OF THE EMBODIMENTS

[0032] Hereinafter, a wire shape measurement device 100 according to an embodiment will be described with reference to the drawings. As shown in FIG. 1 and FIG. 2, the wire shape measurement device 100 is a device for measuring the shape of a wire 30 of a semiconductor device 10, which includes a substrate 11, a semiconductor element 20 mounted on the substrate 11, and the wire 30 connecting an electrode 25 of the semiconductor element 20 and an electrode 12 of the substrate 11. The wire shape measurement device 100 includes a plurality of cameras 41 to 44 that capture two-dimensional images of the semiconductor device 10, and a control unit 50 that inspects the shape of the wire 30 based on the two-dimensional images acquired by the cameras 41 to 44. In the following description, an X direction and a Y direction are orthogonal to each other in a horizontal plane, and a Z direction is a vertical direction.

[0033] As shown in FIG. 2, the cameras 41 and 42 are arranged so that the optical axes 41a and 42a extend in the X direction, and are arranged so as to image the semiconductor device 10 from diagonally above in the X direction. Further, the cameras 43 and 44 are arranged so that the optical axes 43a and 44a extend in the Y direction, and are arranged so as to image the semiconductor device 10 from diagonally above in the Y direction. Therefore, the cameras 41 and 42 are arranged on both sides of the wire 30 extending in the Y direction so that the optical axes 41a and 42a intersect the wire 30 extending in the Y direction, and the cameras 43 and 44 are arranged on both sides of the wire 30 extending in the X direction so that the optical axes 43a and 44a intersect the wire 30 extending in the X direction. Each of the cameras 41 to 44 is connected to the control unit 50, and data of the image acquired by each camera is input to the control unit 50. The control unit 50 is a computer including a CPU 51 that processes information internally, and a memory 52 that stores data, programs, etc.

[0034] Next, an operation of the wire shape measurement device 100 according to the embodiment will be described with reference to FIG. 3 to FIG. 6. In the following description, as shown in FIG. 4, a three-dimensional image of the wire 30 which extends in the X direction between the electrode 25 of the semiconductor element 20 and the electrode 12 of the substrate 11 is generated based on a two-dimensional image captured by the camera 43 arranged diagonally above the wire 30 on the Y-direction plus side and a two-dimensional image captured by the camera 44 arranged diagonally above the wire 30 on the Y-direction minus side, and the shape of the wire 30 extending in the X direction is inspected by using the generated three-dimensional image. In FIG. 4, reference numerals 35 to 37 and 39 indicate portions of the wire 30 located in two-dimensional coordinate detection regions 60 (described later with reference to FIG. 5 and FIG. 6) for detecting two-dimensional coordinates of the wire 30, which are set at predetermined intervals AX in the middle of an X-axis that connects a start end 31 and a terminal end 32 of the wire 30.

[0035] As shown in step S101 of FIG. 3, the CPU 51 of the control unit 50 reads the coordinates (xs, ys), (xe, ye) of the start end 31 of the wire 30 connected to the electrode 25 of the semiconductor element 20 and the terminal end 32 connected to the electrode 12 of the substrate 11 from the memory 52. Here, the coordinates are connection position information of a position where the wire 30 is connected to the semiconductor element 20. Further, the CPU 51 of the control unit 50 reads a diameter of the wire 30 which is thickness information of the wire 30 from the memory 52.

[0036] Next, as shown in step S102 of FIG. 3, the control unit 50 captures images of the semiconductor device 10 with the cameras 43 and 44, and as shown in step S103 of FIG. 3, stores the captured images in the memory 52.

[0037] When the wire 30 is imaged by the camera 43 arranged on the Y-direction plus side of the semiconductor device 10, as shown in FIG. 5, the two-dimensional image of the wire 30 acquired by the camera 43 is an image curved toward the Y-direction minus side according to the change in the height of the wire 30. Further, when the wire 30 is imaged by the camera 44 arranged on the Y-direction minus side of the semiconductor device 10, as shown in FIG. 6, the two-dimensional image of the wire 30 acquired by the camera 44 is an image curved toward the Y-direction plus side according to the change in the height of the wire 30.

[0038] Next, as shown in step S104 of FIG. 3 and FIG. 5, the control unit 50 sets the two-dimensional coordinate detection regions 60 for detecting the two-dimensional coordinates of the wire 30 at the predetermined intervals AX in the middle of the X-axis that connects the start end 31 and the terminal end 32 of the wire 30 in the image acquired by the camera 43. Then, as shown in step S105 of FIG. 3, the control unit 50 searches the two-dimensional coordinate detection regions 60 for a linear image having a thickness the same as the diameter of the wire 30 by using pattern matching. Then, when the control unit 50 detects an image having a thickness the same as the diameter of the wire 30, the control unit 50 acquires the two-dimensional coordinates of the center point of the image as (x31, y31), (x32, y32), (x33, y33) and stores them in the memory 52. The two-dimensional coordinates (x31, y31), (x32, y32), (x33, y33) are two-dimensional coordinates corresponding to the portions 35 to 36 of the wire 30 shown in FIG. 4. Then, the control unit 50 repeats the operation of acquiring the two-dimensional coordinates from the start end 31 to the terminal end 32, and acquires the two-dimensional coordinates (x31, y31) to (x3e, y3e) of the center point of the image having a thickness the same as the diameter of the wire 30 in all the two-dimensional coordinate detection regions 60 from the start end 31 to the terminal end 32. These two-dimensional coordinates are two-dimensional coordinates corresponding to the portions 35 to 39 of the wire 30, respectively.

[0039] Similarly, as shown in FIG. 6, the control unit 50 sets the two-dimensional coordinate detection regions 60 in the image acquired by the camera 44, and searches the two-dimensional coordinate detection regions 60 for a linear image having a thickness the same as the diameter of the wire 30 by using pattern matching. Then, when the control unit 50 detects an image having a thickness the same as the diameter of the wire 30, the control unit 50 acquires the two-dimensional coordinates of the center point of the image as (x41, y41) to (x4e, y4e) and stores them in the memory 52. These two-dimensional coordinates are two-dimensional coordinates corresponding to the portions 35 to 39 of the wire 30, respectively. Then, when the control unit 50 determines YES in step S106 of FIG. 3, the control unit 50 proceeds to step S107 of FIG. 3.

[0040] Since the two-dimensional coordinates (x31, y31) acquired from the image of the camera 43 and the two-dimensional coordinates (x41, y41) acquired from the image of the camera 44 in step S105 of FIG. 3 are two-dimensional coordinates corresponding to the same portion 35 of the wire 30 shown in FIG. 4, three-dimensional coordinates of the portion 35 of the wire 30 can be calculated from the two two-dimensional coordinates and the positions of the cameras 43 and 44. Similarly, since the two-dimensional coordinates (x32, y32) and (x33, y33) acquired from the image of the camera 43 and the two-dimensional coordinates (x42, y42) and (x43, y43) acquired from the image of the camera 44 are two-dimensional coordinates corresponding to the same portions 36 and 37 of the wire 30 shown in FIG. 4, three-dimensional coordinates of the portions 36 and 37 of the wire 30 can be calculated from these coordinates.

[0041] Therefore, in step S107 of FIG. 3, the control unit 50 calculates the three-dimensional coordinates of a plurality of portions 35 to 39 from the start end 31 to the terminal end 32 of the wire 30 shown in FIG. 4 based on the two-dimensional coordinates (x31, y31) to (x3e, y3e) from the start end 31 to the terminal end 32 of the wire 30 acquired by the camera 43, the two-dimensional coordinates (x41, y41) to (x4e, y4e) from the start end 31 to the terminal end 32 of the wire 30 acquired by the camera 44, and the positions of the cameras 43 and 44.

[0042] Then, in step S108 of FIG. 3, the control unit 50 connects the three-dimensional coordinates of the plurality of portions 35 to 39 calculated to generate a three-dimensional image of the wire 30. Therefore, the three-dimensional image of the wire 30 is a curve that is bent three-dimensionally.

[0043] In step S109 of FIG. 3, the control unit 50 measures the dimensions of the shape of the wire 30 based on the generated three-dimensional image of the wire 30. Further, the control unit 50 compares the generated three-dimensional image of the wire 30 with a reference shape such as a reference loop shape of the wire 30 to detect the difference between the two dimensions, and determines that the shape of the wire 30 is abnormal if the difference exceeds a predetermined threshold value.

[0044] In addition, the control unit 50 may also measure the shape parameters of the wire 30 from the generated three-dimensional image of the wire 30, for example, the shape dimensions such as the loop height which is the height from the start end 31 of the wire 30, the thickness of the crimp ball formed at the start end 31, the diameter of the crimp ball, etc., and compare each measured shape dimension with a reference value to perform the inspection.

[0045] As described above, since the wire shape measurement device 100 can generate the three-dimensional image of the wire 30 from the two-dimensional images of the semiconductor device 10 acquired by the cameras 43 and 44 by pattern matching using the two-dimensional coordinates (xs, ys) and (xe, ye) of the start end 31 and the terminal end 32 of the wire 30 and the diameter of the wire 30, the three-dimensional image can be generated accurately in a short time. Thus, it is possible to perform shape measurement and shape inspection on the wire 30 with high accuracy in a short time.

[0046] After inspection of the shape of the wire 30 extending in the Y direction, shape measurement and shape inspection are performed by performing the same processing based on the two-dimensional images captured by the cameras 41 and 42.

[0047] Furthermore, the two-dimensional images acquired by the four cameras 41 to 44, instead of the two cameras 41 and 42 or the two cameras 43 and 44, may be processed to generate the three-dimensional image of the wire 30. In addition, the two-dimensional images of four or more cameras may be processed to generate the three-dimensional image of the wire 30.

[0048] The above-described embodiment illustrates that the wire 30 for shape measurement or shape inspection connects the electrode 25 of the semiconductor element 20 and the electrode 12 of the substrate 11, but the present invention is not limited thereto. For example, the present invention can also be applied to the inspection of the shape of the wire 30 that continuously connects the electrode 25 of the semiconductor element 20 of each layer, the electrode 25 of the semiconductor element 20 of the lowermost layer, and the electrode 12 of the substrate 11 in the semiconductor device 10 which laminates a plurality of semiconductor elements 20 on the substrate 11. In such a case, the wire 30 connects one electrode 25 of the semiconductor element 20 of one layer and another electrode 25 of the semiconductor element 20 of another layer, and connects the electrode 25 of the semiconductor element 20 of the lowermost layer and the electrode 12 of the substrate 11.

[0049] Further, when a wire shape measurement method is executed using the wire shape measurement device 100 according to the embodiment, capturing the two-dimensional images of the semiconductor device 10 with the cameras and storing them in the memory 52, as shown in steps S102 and S103 shown in FIG. 3, corresponds to an image capturing step. Further, generating the three-dimensional image of the wire 30 from the captured two-dimensional images, as shown in steps S104 to S108 of FIG. 3, constitutes a three-dimensional image generation step, and measuring the shape of the wire 30 based on the three-dimensional image, as shown in step S109 of FIG. 3, constitutes a measurement step. In addition, inspecting the shape of the wire 30 based on the three-dimensional image, as shown in step S109 of FIG. 3, constitutes an inspection step.

[0050] Further, the step of extracting the two-dimensional coordinates, as in steps S104 to S106 of FIG. 3, constitutes a two-dimensional coordinate extraction step; the step of calculating the three-dimensional coordinates based on the extracted two-dimensional coordinates, as shown in step S107 of FIG. 3, constitutes a three-dimensional coordinate calculation step; and the step of generating the three-dimensional image of the wire 30 from the calculated three-dimensional coordinates, as shown in step S108 of FIG. 3, constitutes an image generation step.

[0051] Further, when a wire three-dimensional image generation method is executed using the wire shape measurement device 100 according to the embodiment, capturing the two-dimensional images of the semiconductor device 10 with the cameras and storing them in the memory 52, as shown in steps S102 and S103 of FIG. 3, corresponds to the image capturing step. In addition, generating the three-dimensional image of the wire 30 from the captured two-dimensional images, as shown in steps S104 to S108 of FIG. 3, constitutes the three-dimensional image generation step.

DESCRIPTIONS OF REFERENCE NUMERALS

[0052] 10 semiconductor device; 11 substrate; 12, 25 electrode; 20 semiconductor element; 30 wire; 31 start end; 32 terminal end; 41 to 44 camera; 41a to 44a optical axis; 50 control unit; 51 CPU; 52 memory; 60 two-dimensional coordinate detection region; 100 wire shape measurement device.