JPH04255242A - Bonding state inspecting device - Google Patents

Abstract

PURPOSE:To make it possible to inspect the bonding state of bonding wires with high accuracy while the state is observed through a monitoring TV. CONSTITUTION:A bonding state inspecting device is provided with a TV camera 12 for imaging the part to be inspected of a hybrid IC (a hybrid integrated circuit element) 14 lightened by a lightening means 11, a bonding position data memory 17, which stores positions to be connected by a wire bonding with each other and stores the positions, and a whole control means 21 for calculating a bonding position of the IC 14 on an X-Y table 15 on the basis of data on the above positions and enables and X-Y table position control means 16 to control the position of the above X-Y table so as to move the above inspected part to a position in the field of the camera 12 on the basis of the above calculated result.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wire bonding condition inspection apparatus used to inspect the appearance of a hybrid integrated circuit device after a wire bonding process.

0002

[Prior Art] A hybrid integrated circuit device (hereinafter referred to as a hybrid IC) consists of one or more conductive IC chips placed on a ceramic substrate on which a circuit pattern is printed, along with circuit components such as small resistors and capacitors. After the IC chips are attached using adhesive or soldering (die bonding), a gold wire with a diameter of about 25 μm is stretched between the electrodes of the IC chip and the circuit pattern on the ceramic, or between the electrodes of the IC chips. (wire bond), an electrical connection is made. This wire bonding process is normally performed as follows. First, the tip of a gold wire passed through a thin ceramic tube is heated and melted by an electric arc, and due to surface tension it becomes a ball shape larger than the inner diameter of the ceramic thin tube. Next, the tip of the ball-shaped gold wire at the tip of the ceramic thin tube is pressed against a heated electrode section called a bonding pad of the IC chip, and connection is made by forming an alloy between them. This is called the first bond or ball bond. Next, the ceramic thin tube, with the gold wire still passed through it, is moved onto the electrode on the substrate to which electrical connection is to be made, and the gold wire is pressed against this electrode to similarly form a connection by forming an alloy. This is called the second bond or stitch bond. moreover,
After the ceramic capillary moves upward, the gold wire is pulled upward to break from the constriction of the stitch bond portion, completing the bonding of one bonding wire. After all the bonding wires have been bonded, the molding process begins, but since the inside cannot be seen once it is molded, an external appearance inspection is normally performed just before that, and in particular, it is important to inspect the bonding condition of the gold wires. most important.

FIG. 24 is a perspective view showing a conventional bonding condition inspection device. In the figure, 1 is a stereoscopic microscope, and 3
2 is a mounting table that supports the stereomicroscope and on which the hybrid IC 14 to be inspected is placed; 2 is a worker looking into the stereomicroscope 1; 4 and 5 are the hands of the worker. According to this, the worker 2 looks into the stereomicroscope 1 while holding the hybrid IC 14 on the mounting table 3 with his left and right hands 4 and 5, and checks whether the gold wire is properly bonded at the position where it should be bonded. Check and separate good and defective products. At this time, since it is not possible to see the whole thing in one field of view, all the bonding locations are confirmed while moving the hybrid IC using the left and right hands 4 and 5.

Further, the bonding state at this time may be as shown in FIG. 23. That is, FIG. 23(a)
The gold wire 7 is attached to the bonding pad 6a on the IC chip 6.
The ball bond portions 7a of the circuit patterns 8
23(b) shows a state in which the gold wire 7 is bent, and FIG. 23(c) shows a state in which the gold wire 7 is connected to another gold wire. 23(d) shows the state in which the ball bond part 7a is displaced, and FIG. 23(e) shows the state in which the ball bond part 7a is in the vicinity of the line 7.
(f) shows the incorrect bonding position, and Fig. 23 (g)
) respectively indicate the state in which the gold wire 7 is broken. In other words, conventionally, such a bonding state has been inspected using the stereoscopic microscope 1, relying entirely on intuition.

[0005]

[Problem to be Solved by the Invention] Since the conventional bonding condition inspection device is constructed as described above, when the circuit becomes complicated and the number of bonding wires, which are gold wires 7, increases, all of these This made it difficult to check all the necessary information, leading to problems such as mistakenly missing inspections. In particular, when bonding is forgotten, there is no bonding trace left on the IC chip 6, so the above-mentioned oversight is likely to occur. Further, even if the bonding state or wire shape is incorrectly bonded between the electrodes, it is easy to confirm that the bonding is normal and overlook the bonding error. Furthermore, when the bonding wire approaches the limit value of pass/fail due to bending or proximity, the judgment varies depending on the subjectivity of the operator, making it difficult to maintain stable inspection standards.

[0006] This invention was made in order to solve the above-mentioned problems, and by inspecting the bonding condition of all bonding wires without overlooking them and comparing them with reference values when necessary, it eliminates subjectivity as much as possible. It is an object of the present invention to provide a bonding condition inspection device capable of performing an external appearance inspection with high accuracy. Incidentally, there is a similar prior art disclosed in Japanese Patent Laid-Open No. 150433/1983.

[0007]

[Means for Solving the Problems] A bonding state inspection device according to the present invention includes a television camera that images an inspection area of a hybrid IC illuminated by an illumination means, and a bonding state that associates and stores positions to be connected by wire bonding. Hybrid IC in the XY table based on the position data memory and the above position data
and an overall control means for calculating the bonding position of the XY table, and the XY table position control means controls the XY table position so as to move the inspection area to the viewing position of the television camera based on the calculation result. This is what I did.

[0008]

[Operation] The bonding inspection apparatus according to the present invention determines the bonding position of the bonding wire to be inspected by the overall control means according to the bonding position data memory, sequentially images the bonding wire, and
To accurately determine whether the bonding condition displayed on a monitor is good or bad, and thereby to accurately grasp the bonding condition without incorporating the subjectivity of an inspector.

[0009]

[Embodiment] An embodiment of the present invention will be described below. In FIG. 1, 11 is an illumination means for illuminating the inspection site;
Reference numeral 12 denotes a television camera that images the inspection site, 13 a monitor television that displays the captured image, 14 a hybrid IC to be inspected, 15 an XY table on which the hybrid IC 14 is placed, and 16 a control for the position of the XY table 15. XY table position control means; 17 is a bonding position data memory that associates and stores the positions of two points to be connected by wire bonding; 18 is a pointing device that indicates a point on an image displayed on a monitor television; 19 is a pass/fail judgment Determination input means for inputting results; 20 is determination result output means for outputting determination results; and 21 is overall control means for controlling the entire apparatus. FIG. 2 also shows the contents of the bonding position data memory 17, including the positioning mark position coordinates on the substrate, the positioning mark position coordinates of the IC chip, and each design value of the ball bond position coordinates and stitch bond position coordinates for each bonding wire. Data is stored in advance. Note that here, in order to simplify the explanation, only one IC chip is used. Hybrid IC
The z-axis (vertical direction) coordinate of the bonding position on 14 is not constant, and therefore data is stored as three-dimensional coordinates (x, y, z). Further, the coordinates are displayed in an XY table coordinate system.

Next, the operation of this bonding state inspection apparatus will be explained according to the flowchart shown in FIG. First, the hybrid IC 14, which is the object to be inspected, is fixed on the XY table 15 (step ST31), and then the illumination means 11 is turned on (step ST32). In addition, the XY table 15 is controlled by the XY table position control means 16 so that the "first positioning mark position of the board" in the bonding position data memory 17 is located at the center of the field of view of the television camera 12. The first positioning mark of is displayed (step ST
33). FIG. 4 shows an example in which such a positioning mark 42 is displayed. Normally, because there is a positioning error when fixing the hybrid IC 14 to the XY table 15, the positioning mark 42 is displayed slightly off the center of the screen 41. . Therefore, the operator operates the pointing device 18 to input the exact position of the first positioning mark on the board to the overall control means 21 (step ST34).
).

Next, in the same manner, the exact position of the second positioning mark on the board is input to the overall control means 21. The first positioning mark and the second positioning mark on the substrate are provided at diagonal positions on the substrate of the hybrid IC 14 (step ST35). By inputting the precise positions of the first and second positioning marks 42 on the substrate, the overall control means 21 controls the hybrid IC 14 for each coordinate data position indicated in the bonding position data memory 17.
The XY table can be moved so that the required position of the hybrid IC 14 is at the center of the field of view of the television camera 12 by correcting positioning errors including rotational deviations (step ST36). In the following description, it is assumed that the positioning error of the hybrid IC 14 has been corrected.

Next, the bonding position data memory 17
The XY table 15 is controlled by the XY table position control means 16 so that the "first positioning mark position of the IC chip" is located at the center of the field of view of the television camera 12, and the first positioning mark of the IC chip is displayed on the monitor television 13. is displayed (step ST37). This mark is the same mark as the positioning mark on the board. Since the IC chip is mounted with some deviation from the designed position within the allowable range during die bonding, the positioning mark is displayed slightly off the center of the screen. Therefore, the operator operates the pointing device 18 to input the exact position of the positioning mark to the overall control means 21 (step ST3).
8).

Next, in the same manner, the exact position of the second positioning mark of the IC chip is input to the overall control means 21 (step ST39). As a result, this positioning mark is displayed (step ST3a). The first positioning mark and the second positioning mark of the IC chip are provided at diagonal positions of the IC chip. By inputting the precise positions of the first and second positioning marks of the IC chip, the overall control means 21 includes the rotational deviation of the IC chip for each ball bond position specified in the bonding position data memory 17. The position of the ball bond position on the XY table is calculated by correcting the die bond shift. In the following explanation, it will be assumed that correction of this die bond shift with respect to the ball bond position is performed in addition to correction of the hybrid IC positioning error.

Next, the overall control means 21 calculates the ball bond position and die bond position of the bonding wire #1 to be inspected, and moves the XY table so that the entire bonding wire is in the center of the field of view of the television camera 12. A command is issued to the position control means 16 to move the bonding wire #1 to the camera field of view position (step ST36).
). Thereby, an image of the inspection site is captured by the television camera 12 (step ST3c). Next, this image is displayed on the monitor television 13 (step ST3d).
An inspection operator looks at the image and determines whether the object is a good item or a defective item, and the overall control means 21 uses the judgment input means 19.
The determination result is input for (step ST3e). Furthermore, the series of processes from steps ST3b to ST3e are as follows:
This process is repeated until all bonding wires on the hybrid IC 14 to be tested are finished (step ST3f).
), then the test result is sent by the judgment result output means 20 to a printing means such as a memory, an external storage device, a printer, etc., and the test operation is completed. In the explanation of the operation of this embodiment, the lights are turned on after fixing the hybrid IC 14, but the order may be reversed.

Furthermore, although it has been explained that one bonding wire is displayed on one screen on the monitor television 13, it is possible to display a plurality of bonding wires on one screen if possible.
The quality determination result for each bonding wire may be input from the determination result input means 19. moreover,
For long wires that do not fit into the camera's field of view, inspection may be performed by dividing the display into two or more screens. Further, in the above embodiment, the case where there is one IC chip has been described, but the same applies to the case where a plurality of hybrid ICs 14 are installed. Furthermore, although a cross mark is shown as the positioning mark in the above embodiment, any shape may be used as long as the center of the mark is easily recognized, such as a circle mark. In this case, the corners of the originally formed circuit pattern can be used instead of the positioning marks without providing any special positioning marks. In the above embodiment, the hybrid IC 14 is moved, but the viewing position may be controlled by moving the television camera 12.

Furthermore, the bonding position data memory 17
shows an example in which the coordinate data is displayed using the coordinate values of the XY table, but it is also possible to display only the origin coordinates of the board using the coordinate values of the XY table, and displaying the rest using relative coordinates from the origin of the board. Alternatively, the origin coordinates of the IC chip may be expressed as relative coordinates from the origin of the substrate, and the ball bond positions may be expressed as relative coordinates from the origin of the IC chip. Furthermore, the lens section of the television camera 12 may be a three-lens stereoscopic microscope to which the television camera 12 is attached, and the left and right images may be switched and displayed on the monitor television 13 as necessary. 1 TV camera each on the left and right eyepieces
3 may be installed and the left and right screens may be switched as necessary, or two monitor televisions 13 may be installed to display left and right images at the same time. Alternatively, instead of using a stereomicroscope, two independent television cameras may be installed at slightly different angles to obtain the same field of view. Furthermore, a plurality of cameras with different magnifications may be arranged, and the magnification of the image displayed on the monitor screen may be switched as necessary. In the above embodiment, a case has been described in which the positioning error of the hybrid IC 14 is corrected by operating the pointing device 18 and inputting the accurate position of the positioning mark to the overall control means 21. The positioning mark position may be detected by image recognition such as the above, and the positioning error may be automatically corrected.

FIG. 5 is a block diagram showing another embodiment of the present invention, in which lighting control means 51 is provided to control the lighting means 11 in accordance with the control output of the overall control means 21. In addition, the flow of operation of this embodiment inspection device is shown in Fig. 6.
The operation is explained below. First, as in the case of FIG. 3, the hybrid IC 14, which is the object to be inspected, is fixed on the XY table 15 (step ST31). Next, the illumination means 11 is turned on (step ST32), and the hybrid IC 14, which is the object to be inspected, is positioned by inputting the positioning mark position using the pointing device 18 by the operator (step ST61). This process corresponds to steps ST33 to ST3a in FIG. 3 explained in the above embodiment, so a detailed explanation will be omitted. After positioning, the overall control means 21 then controls the hybrid IC.
14, and moves the XY table to the imaging site determined based on each coordinate data position specified in the bonding position data memory 17 (step ST36). Next, the lighting means are controlled. In other words, according to preset lighting conditions,
The illumination means 11 is controlled by the illumination control means 51 (step ST62). FIG. 7 shows an example of illumination means 11 whose illumination direction can be controlled. In the figure, 701 to 716 are high-intensity LEDs as light emitting elements, and these are arranged on two concentric circles on the horizontal donut-shaped disk 9. These LEDs 701 to 716 can be lit independently one by one, but they are electrically divided into eight sets of blocks B0 to B7, making it possible to light them in units of blocks B0 to B7. ing.

FIG. 8 is a schematic diagram of a wire bond section as an inspection object placed within the field of view of the television camera 12, in which five bonding wires W1 to W5 are connected from the IC chip 14a to the surrounding bonding pad 6a. An example of bonding is shown below. When imaging bonding W1 and W2, each LED of blocks B0 and B4
701, 702, 709, and 710 are turned on. As a result, the bonding wires W1 and W2 are imaged brighter than the background. When you want to clearly image the ball part or stitch part, each LED 705 of blocks B2 and B6 is also used.
, 706, 713, and 714 are turned on. Note that if the LEDs of the other blocks B1, B3, B5, and B7 are turned on, parts other than the bonding wires W1 and W2 will be imaged brightly, and the contrast of the bonding wires W1 and W2 will decrease, which is not good. In the case of bonding wire W3, each LED of blocks B3 and B7 (blocks B1 and B5 are also added as necessary) is lit in the same way. In the case of bonding wires W4 and W5, each LED of blocks B2 and B6 is lit. Figure 9 shows the LE of Figure 7.
D This is a schematic view of the diagonal illumination section and the bonding wire to be inspected from the side, and here each LED on the concentric circle is
are installed so that the light exit angles are different between the inner and outer rows. Here, the inner LEDs 701 and 709 can illuminate the object at an incident angle closer to the vertical than the outer LEDs 702 and 710. Therefore, in order to image the bonding wire W1 with a large step difference as shown in the figure, the outer LED 702 is mainly turned on, and in order to image the bonding wire W2 where the wire angle is close to horizontal, the inner LED 702 is turned on.
Turn on 9. In either case, each wire W is reflected by the illumination light and enters the objective lens 81.
1, W2 is imaged brightly against the background. If the background surface is smooth, the LEDs 701 and 70 on both the inside and outside
Even if wires 9, 702, and 710 are turned on, the background is rarely imaged brightly, and each wire W1, W2 can be imaged brightly and with high contrast. As explained above, by using an illumination means that can control the incident angle and direction using LEDs, images of wires, balls, and stitch parts can be captured under optimal illumination conditions according to the direction or angle (step) of the wire. becomes possible. When such illumination is performed, an image of the inspection site is then captured by the television camera 12 (step ST3c), and this image is displayed on the monitor television 13 (step ST3d). Then, the inspection operator looks at the image and determines whether the object is a good item or a defective item, and inputs the judgment to the overall control means 21 using the judgment input means 19 (step ST3e).
. In this way, the series of processing from step ST3b to step ST3e is repeated until all wires on the hybrid IC 14 to be tested are finished (step ST3e).
T3f), and then the test results are sent to the judgment result output means 20.
The data is sent to a printing means such as a memory, an external storage device, or a printer (step ST3g), and the inspection operation is completed.

Although this embodiment shows the case where so-called oblique illumination using LEDs is controlled, a light emitting element other than LEDs may be used, and epi-illumination means coaxial with the camera may be provided to control the illumination at the same time. It's okay. In addition, wires W1, W
2 has been explained about the case where the image is to be imaged brightly against the background, but conversely, if you want to image the background brightly and the wire darkly, turn on strong epi-illumination, and if necessary, turn on only a part of the oblique illumination. It is effective if you do it.

FIG. 10 is a block diagram showing still another embodiment of the present invention, in which guide mark generation means for controlling the monitor television 13 in accordance with the output of the overall control means 21 is provided. The flow chart of FIG. 11 shows the operation flow of the bonding state inspection apparatus in this embodiment. The operation will be explained below. First, the hybrid IC 14, which is the object to be inspected, is fixed on the XY table 15 (step ST31). next,
The illumination means 11 is turned on (step ST32). The hybrid IC 14, which is the object to be inspected, is positioned by inputting the positioning mark position using the pointing device 18 by the operator (step ST61). This process is performed in step ST33 in FIG. 3 explained in the above embodiment.
to step ST3a, detailed explanation will be omitted. When positioning is performed in this way,
Next, the overall control means 21 corrects positioning errors including rotational deviations of the hybrid IC 14 and moves the XY table to the imaging region determined based on each coordinate data position instructed in the bonding position data memory 17. (step ST36). Further, an image of the inspection site is captured by the television camera 12 (step ST3c) and displayed on the monitor television 13 (step ST3d).

[0021] Then, the guide mark is displayed superimposed on the image of the wire to be inspected (step S
T101). This guide mark is as shown in Fig. 12, and is a tolerance database 9 set for each wire.
The guide mark is generated by the guide mark generating means 92 using the tolerance data within 1 and the data of the bonding position data memory 17. In other words, the cross-shaped mark 111 displayed overlapping the ball part in FIG. 12 means that the intersection point is the ball center reference coordinates, and the operator can check if the actual ball center coordinates are out of alignment with this mark. Determine if there is. A cross mark 112 displayed overlapping the stitch portion also indicates the same stitch center reference coordinates. In addition, a rectangular frame 113 displayed overlapping the wire W1 indicates the bending tolerance range for defective bending of the wire W1, and if a part of the actual wire W1 protrudes outside this frame 113, the bending It is judged as defective. Double circle mark 11 overlapping the ball part
4 indicates the minimum value (inner circle) and maximum value (outer circle) of the ball size, and if the actual ball does not have a size within these ranges, it is determined to be defective. These several types of marks are displayed in the same color for one wire W1 so that they can be distinguished from the mark for the adjacent wire W2. Therefore, even if a "wrong bond" defect occurs like wire W2, it can be easily determined. The operator selects the guide marks 111, 112, 113,
114 and the actual wire image, it is determined whether the object is a good product or a defective product, and the determination input means 19 inputs the determination to the overall control means 21 in step ST3e. The series of processes from step ST3b to step ST3e is repeated until all wires W1 to Wn on the hybrid IC 14 to be tested are finished (step ST3f), and then the test results are sent from the determination result output means 20. The information is sent to a printing means such as a memory, an external storage device, or a printer (step ST3g), and the inspection operation is completed.

In this embodiment, cross marks 111 and 112 are used to indicate the coordinates, rectangular marks 113 are used to express the range, and colors are used to indicate the corresponding wires W1 and W2. It goes without saying that the same effect can be achieved even if it is realized using ``'' marks, line segments, marks with numbers, etc. Further, the double circle mark 114 for checking the ball size does not need to overlap the ball bond part, and may be displayed with a slightly shifted position. Furthermore, the same effect can be expected even if this double circle mark 114 is displayed near the stitch bond portion.

FIG. 13 is a block diagram showing still another embodiment of the present invention, in which the television camera 12 is provided with a focus control section 121. Further, FIG. 14 is a flowchart showing the operation flow of the bonding state inspection apparatus in this embodiment. This operation will be explained below. First, the hybrid IC 14, which is the object to be inspected,
is fixed on the Y table 15 (step ST31),
Next, the illumination means 11 is turned on (step ST32
). Further, the hybrid IC 14, which is the object to be inspected, is positioned by inputting a positioning mark position using the pointing device 18 of the operator (step ST61). Since this process corresponds to steps ST33 to ST3a in FIG. 3 explained in the above embodiment, detailed explanation will be omitted. When the positioning is performed, the overall control means 21 then corrects the positioning error including the rotational deviation of the hybrid IC 14, and positions the imaged portion determined based on each coordinate data position instructed in the bonding position data memory 17. , move the XY table (step ST3b). The focus position is controlled by the focus control unit 121 attached to the television camera 12 (step ST131). This is possible by having a bonding position data memory 17 described in three-dimensional coordinates as shown in FIG. This focal point is determined, for example, as the midpoint between the z-coordinate of the ball part and the z-coordinate of the stitch part (if a plurality of wires are included in the image, their center of gravity).

Next, an image of the inspection area is taken by the television camera 12 (step ST3c), and the monitor television 1
3 (step ST3d). The operator looks at the wire image, determines whether the object is a good product or a defective product, and inputs the determination result to the overall control means 21 using the determination input means 19 (step ST3e). These steps S
The series of processing from T3b to step ST3e is repeated until all wires on the hybrid IC 14 to be tested are finished (step ST3f), and then the test results are sent to the memory, external storage device, It is sent to a printing means such as a printer (step ST
3g), end the inspection operation. In this embodiment, a focus movement mechanism attached to the television camera 12 is used as a focus control unit for controlling the focus, but a z-axis movement mechanism may be provided at the bottom or top of the XY table on which the inspection object is transferred. Even if it is provided, the same effect can be obtained.

FIG. 15 is a flowchart showing the operation flow of a bonding condition inspection apparatus according to another embodiment of the present invention, and its configuration is the same as that shown in FIG. The operation will be explained below. First, the hybrid IC 14, which is the object to be inspected, is fixed on the XY table 15 (step ST31), and then the illumination means 1
1 is lit (step ST32). Next, the hybrid IC 14, which is the object to be inspected, is positioned by inputting a positioning mark position using the pointing device 18 by the operator (step 61). Since this process corresponds to steps ST33 to ST3a in FIG. 3 explained in the above embodiment, detailed explanation will be omitted. Once the positioning is performed, the overall control means 2
1 corrects positioning errors including rotational deviation of the hybrid IC 14, and moves the XY table to the imaging region determined based on each coordinate data position instructed in the bonding position data memory 17 (step ST3b).
. Furthermore, an image of the inspection site is captured by the television camera 12 (step ST3c) and displayed on the monitor television 13 (step ST3d). Figure 16 shows the TV monitor 13.
FIG. 2 is a schematic diagram of a part of the inspection target displayed on the screen of FIG. Here, a case will be described in which the operator measures the diameter of a ball on the screen. The operator first points to pointing point A 151 and pointing point B 152 in the figure using the pointing device 18 that can specify any point on the screen. These points form opposite ends of the diameter of the ball section. The coordinates of point A on the image are (Xa, Ya), and the coordinates of point B are (X
b, Yb), and the pixel/actual distance ratio determined by the geometric parameters of the imaging means and the distance to the object is x
If direction Kx and y direction Ky [mm/pixel], then A-B
The actual distance L [mm] between them is as shown in Equation 1.

[0026]

[Math 1]

The overall control means 21 outputs the result to the monitor television 13. The operator performs the above-mentioned measurements as necessary (step ST141), looks at the wire image, determines whether the object is a good product or a defective product, and transmits the determination result to the overall control means 21 from the determination input means 19. is input (step ST3c). Further, the series of processing from step ST3b to step ST3e is repeated until all wires on the hybrid IC 14 to be tested are finished (step ST3f). After that, the test results are sent to the memory and external device by the judgment result output means 20. The information is sent to a printing means such as a storage device or a printer (step ST3g), and the inspection operation is completed.

FIG. 17 is a flowchart showing the operation flow of a bonding condition inspection apparatus according to yet another embodiment of the present invention, and its configuration is the same as that shown in FIG. The operation will be explained below. First, the hybrid IC 14, which is the object to be inspected, is placed on the XY table 1.
5 (step ST31), and then the illumination means 11 is turned on (step ST32). Subsequently, the hybrid IC 14, which is the object to be inspected, is positioned by inputting the positioning mark position by the operator's pointing device 18 (step ST61).
. This process is performed at step ST in FIG. 3 explained in the above embodiment.
33 to step ST3a, detailed explanation will be omitted. When the positioning is performed, the overall control means 21 then corrects the positioning error including the rotational deviation of the hybrid IC 14, and images the imaged region determined based on each coordinate data position specified in the bonding position data memory 17. The XY table is moved to (step ST3b). Further, an image of the inspection site is captured by the television camera 12 (step ST3c), and the image is taken by the monitor television 1.
3 (step ST3d). FIG. 18 is a schematic diagram of a part of the inspection target displayed on the monitor screen. Here, a case will be described in which the operator measures the amount of wire bending on the screen. The operator first points to pointing point A171, pointing point B172, and pointing point C173 in the figure using the pointing device 18 that can point at any point on the screen. Point A and point B are the actual ball center coordinates and stitch center coordinates displayed in the image, respectively, and point C is the point on the wire where the amount of wire bending is maximum. Let the coordinates of point A on the image be (Xa,
Ya), the coordinates of point B are (Xb, Yb), and the coordinates of point C are (
Xc, Yc), and the pixel/actual distance ratio determined by the geometric parameters of the imaging means and the distance to the object are Ky in the x direction and Ky in the y direction [mm/pixel], then point A
The shortest distance Δd between the straight line l obtained by connecting and point B and point C
[mm] is as shown in Equation 2.

[0029]

[Math 2]

Further, the overall control means 21 outputs the result to the monitor television 13. The operator performs the above-mentioned measurements as necessary, determines whether the object is a good product or a defective product by looking at the wire image, and inputs the determination result to the overall control means 21 using the determination input means 19 (step ST3
e). Further, the series of processes from step ST3b to step ST3e is repeated until all wires on the hybrid IC 14 to be tested are finished (step ST3e).
T3f), and then the test results are sent to the judgment result output means 20.
The data is sent to a printing means such as a memory, an external storage device, or a printer (step ST3g), and the inspection operation is completed.

FIG. 19 is a block diagram showing another embodiment of the present invention, which includes a wire attribute data memory 181 that controls the XY table position control means 16 according to the output of the overall control means 21, and an imaging region determination means 182. has been established. Further, the flowchart of FIG. 20 shows the flow of the operation of the bonding state inspection apparatus in this embodiment. The operation will be explained below. First, the hybrid IC 14, which is the object to be inspected, is fixed on the XY table 15 (step ST31), and then the illumination means 11 is controlled by the illumination control means 41 to be in the illumination state necessary for positioning ( Step ST32
). Next, the hybrid IC 14, which is the object to be inspected, is positioned by inputting the position of the positioning mark using the pointing device 18 by the operator (step ST61). This process corresponds to steps ST33 to ST3a in FIG. 3 explained in the above embodiment, so a detailed explanation will be omitted. When the positioning is performed in this way, the overall control means 21 then corrects the positioning error including the rotational deviation of the hybrid IC 14, and corrects each coordinate data position and wire attribute specified in the bonding position data memory 17. The imaging region is determined based on the optimum illumination conditions for each wire specified in the data memory 181 (step ST191).

[0032] This imaging region determining operation will now be described in detail. FIG. 21 is a flowchart showing the flow of the imaging region determination operation, and here, explanation will be given along this flow. First, imaging wire candidates that can be included in the same camera field of view are found (step ST201). For this purpose, each coordinate data position specified in the bonding position data memory 17 and the optimum illumination condition data for each wire specified in the wire attribute data memory 181 are used. FIG. 22 shows these wire coordinate data and optimum illumination condition data organized into one table by wire number. Further, FIG. 23 is a diagram schematically showing a part of the hybrid IC 14, and the wire numbers in FIG. 22 and FIG. 23 correspond to each other. For example, wire W1 has ball center coordinates (x
, y, z) = (50, 73, 16), indicating that the stitch center coordinates are (x, y, z) = (45, 30, 0). In addition, the illumination conditions are as follows: LED oblique illumination shown in the embodiment of FIG. 7 is used, and LED block B0 of FIG.
For ~B7, enter "1" if it lights up, and enter "0" if it does not light up. From FIG. 22, wire W1
The optimum lighting condition is that only blocks B0 and B4 are lit and the others are not lit. This condition must be determined for each wire in advance. Assume an effective imaging field that is the same size as the camera field of view, or set smaller than that, and try to fit as many wires as possible into it. In FIG. 23,
Wires W1 and W enter the effective imaging field of view f1.
2, W3 is selected as a candidate. Next, among the plurality of wires, only those with the same lighting conditions are selected (step ST2
02). From the table of FIG. 22, it can be seen that the wires W1, W2, and W3 are all under the same illumination condition, and all three wires W1 to W3 are selected to calculate the visual field position (step ST203). Similarly, the field of view f2 causes the wire W4 to move, and the field of view f3 causes the wires W5 and W6 to move.
, W7, and the wires W8 and W10 are inspected by the field of view f4, respectively. The reason why the wires W4 and W5 do not have the same field of view even though they are located close to each other is because the lighting conditions for the wires W4 and W5 are different.

Returning to the flowchart of FIG. 20, the illumination control means 51 controls and lights up the illumination means in accordance with the illumination conditions instructed in the wire attribute data memory 181 (step ST192). Furthermore, the XY table 15 is actually moved to move the wire to be inspected to the camera viewing position (step ST3b). Next, an image of the inspection area is captured by the television camera 12 (step ST3c), and when this image is displayed on the monitor television 13 (step ST3d), the inspection operator looks at the image and determines whether the object is good or defective. The determination result is input from the determination input means 19 to the overall control means 21 (step ST3e). Such step ST191
A series of processes from to step ST3e are repeated until all wires on the hybrid IC 14 to be tested are finished (step ST3f), and then the test results are transferred from the judgment result output means 20 to the memory, external storage device, or printer. etc. (step ST3g),
Finish the inspection operation. In this embodiment, LED oblique illumination as shown in FIGS. 7 to 9 is used as the illumination means, but epi-illumination coaxial with the camera may also be added. In that case, the epi-illumination is stored in the wire attribute data memory 181. Write down the conditions in advance.

[0034]

As described above, according to the present invention, there is provided a television camera that images the inspection area of a hybrid IC illuminated by the illumination means, and a bonding position data memory that stores the positions to be connected by wire bonding in association with each other. The XY table position control means is provided with a bonding position data memory for storing the positions to be connected in association with each other, and an overall control means for calculating the bonding position of the hybrid IC on the XY table based on the data of the said position. Based on the above calculation results, the XY table position is controlled so as to move the inspection area to the viewing position of the television camera.
There is an effect that the bonding state of the bonding wires of the hybrid IC can be accurately and without oversight while looking at the image displayed on the monitor television without relying on the intuition of the worker performing the inspection.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a bonding condition inspection device according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing data contents in a bonding position data memory in FIG. 1;

FIG. 3 is a flowchart showing the operation of the bonding state inspection device of FIG. 1;

FIG. 4 is an explanatory diagram showing positioning marks on the hybrid IC.

FIG. 5 is a block diagram showing a bonding condition inspection device according to another embodiment of the present invention.

FIG. 6 is a flowchart showing the operation of the bonding state inspection device of FIG. 5;

7 is a plan view showing the lighting device in FIG. 5. FIG.

FIG. 8 is a plan view of a wire bonding portion.

FIG. 9 is an explanatory diagram showing an optical positional relationship between a lighting device and a bonding wire.

FIG. 10 is a block diagram showing a bonding state inspection device according to still another embodiment of the present invention.

FIG. 11 is a flowchart showing the operation of the bonding state inspection device of FIG. 10;

FIG. 12 is an explanatory diagram showing guide marks displayed on a monitor television.

FIG. 13 is a block diagram showing a bonding condition inspection device according to another embodiment of the present invention.

FIG. 14 is a flowchart showing the operation of the bonding state inspection device of FIG. 13;

FIG. 15 is a flowchart showing another example of the operation of the bonding state inspection device.

FIG. 16 is an explanatory diagram showing a method of giving coordinates of two points on a monitor television screen.

FIG. 17 is a flowchart showing still another example of the operation of the bonding state inspection device.

FIG. 18 is an explanatory diagram showing a method of giving coordinates of three points on a monitor television screen.

FIG. 19 is a block diagram showing a bonding state inspection device according to another embodiment of the present invention.

FIG. 20 is a flowchart showing the operation of the bonding state inspection device of FIG. 19;

FIG. 21 is a flowchart showing the flow of processing for automatically determining an examination site.

FIG. 22 is a table showing the relationship between the contents of a bonding position data memory consisting of ball positions, stitch positions, and illumination conditions and the contents of wire attribute data.

23 is a plan view showing the hybrid IC in FIG. 19. FIG.

FIG. 24 is a perspective view showing a conventional bonding state inspection device.

FIG. 25 is an explanatory diagram showing good and bad bonding states of the bonding wire.

[Explanation of symbols]

11 lighting means 12 television camera 14 hybrid integrated circuit element (hybrid IC
) 15 XY table 16 XY table position control means 17 Bonding position data memory 21 Overall control means Note that in the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1. An XY table on which a wire-bonded hybrid integrated circuit element is placed, an illumination means for illuminating an inspection area of the hybrid integrated circuit element on the XY table, and an image of the illuminated inspection area. A bonding position data memory stores the television camera and the position to be connected by wire bonding in association with each other, and a bonding position of the hybrid integrated circuit element in the XY table is calculated based on data from the bonding position data memory. A bonding state inspection device comprising an overall control means and an XY table position control means for controlling the XY table so as to move the inspection part to the viewing position of the television camera based on the calculation result of the overall control means. .