JP4073175B2 - Bonding equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a pad (electrode) on an IC chip to be bonded in an assembling process of a semiconductor device, and an external lead formed on a lead frame or the like to be bonded to which the IC chip is attached. The present invention relates to a bonding apparatus for connecting a wire with a bonding wire or the like.
[0002]
[Prior art]
Conventionally, a wire bonding apparatus as shown in FIG. 9 is known as a bonding apparatus for connecting pads (electrodes) on an IC chip and external leads.
[0003]
As shown in FIG. 9, the wire bonding apparatus includes a camera 1 as an imaging means including a camera head 1a, an optical lens 1b (hereinafter referred to as a lens), a bonding arm 2 having a capillary 2a attached to the tip thereof, and bonding. XY as positioning means for positioning by moving two-dimensionally in the X and Y directions by mounting the bonding head 3 for driving the arm 2 up and down, the bonding means and the imaging means comprising the bonding arm 2 and the bonding head 3 A table 4 and a transfer device 5 having a bonding stage 7 on which a bonding operation is performed by a bonding head 3 including a capillary 2a and a bonding arm 2 are provided. The bonding stage 7 includes a plurality of IC chips 6 in the longitudinal direction. Reed towels attached side by side And a heater 7a to heat the over arm L / F and the like.
[0004]
  As shown in FIG. 9, the wire bonding apparatus includes an image processing device 30 that receives an imaging signal from the camera 1, a monitor 9 that receives an output from the image processing device 30, a control device 10 that includes a microprocessor, A signal for manually moving the XY table 4 is output to the control device 10.manipulator17 and a drive device 11 that issues a drive signal to the bonding head 3 and the XY table 4 in response to a command signal from the control device 10. An operation switch 18 is connected to the control device 10.
[0005]
As shown in FIGS. 9 and 10, in the wire bonding apparatus, the lead frame L \ F is carried into the bonding stage 7 heated at the start of the operation by the transfer device 5, and the earliest IC chip 6 is bonded. Positioned at the working position. In this state, the bonding arm 2 and the XY table 4 are operated to perform a bonding operation on the earliest IC chip 6. For example, the IC chip 6 is formed in a square shape, and a large number of pads 6a are arranged in parallel along the outer periphery of the upper surface of the IC chip 6. The IC chip 6 is attached to the land portion 14 formed in the lead frame L \ F. The lead frame L \ F is provided with leads 20 corresponding to the pads 6a.
[0006]
Next, self-teach performed in advance prior to the bonding operation will be described. The self-teach is for setting various conditions related to bonding positions on the pads 6a and leads 20 to be bonded.
[0007]
  As shown in FIG. 9, the operator moves the XY table 4 by operating the manipulator 17 while viewing the image based on the image pickup signal from the camera 1 on the monitor 9, and is provided on the screen of the monitor 9. When the intersection O of the cross line 9a is aligned with at least one fixed point on the IC chip 6 and when the alignment is performed at two points, as shown in FIGS. 9 and 10, the intersection O of the cross line 9a is self-adjusted. In accordance with two fixed points on the IC chip 6 set by teaching, the positions of the XY table 4 at this time are defined as a first reference point a and a second reference point b. Note that the operatormanipulator17 is operated to move the camera 1 on the XY table 4, and the intersection point O of the cross line 9a provided on the screen of the monitor 9 is set to a fixed point on the IC chip, the center point of the pad, the center point of the lead, etc. The operation to adjust toCalled. As is clear from FIG.Of camera 1Optical lens 1bThe position of the XY table is different from the position of the coordinate of the XY table, and the case where the position is viewed from the screen of the monitor 9 is the alignment, and the position coordinate of the XY table at that time is the first reference point a or the second reference point b. It is.
[0008]
Then, the position coordinates of the first reference point a and the second reference point b of the XY table 4 at a fixed point on the IC chip 6 are stored in a memory (storage device) in the control device 10, and the first coordinate of the XY table 4 is also stored. An image centered on a fixed point of the IC chip 6 in the window 9b on the monitor 9 at the reference point a and the second reference point b is used as a reference pattern (a window 9b on the monitor 9 shown in FIG. 9) of the image processing apparatus 30. It is stored in a memory (storage device).
[0009]
  Next, the alignment at the first reference point a and the second reference point b described above is the alignment of the IC chip 6, but in addition, the alignment is performed at 0 point or at least one point on the lead frame L / F. Need to do. As shown in FIG. 10, when there are two pads and one lead, the lead frame L / F is self-taught.The position of the XY table 4 at this time is set as the third reference point c in accordance with one fixed point on the upper side.
[0010]
Then, the position coordinates of the third reference point c of the XY table 4 are stored in the memory in the control device 10, and the lead frame L / in the window 9b on the monitor 9 at the third reference point c of the XY table 4 is stored. An image centered on a fixed point on F is stored in the memory of the image processing apparatus 30 as a reference pattern.
[0011]
As described above, all the pads 6a and the leads 20 are aligned, and the position coordinates of the bonding points are stored in the memory in the control device 10.
[0012]
Next, the wire bonding operation by the bonding apparatus will be described.
[0013]
In the wire bonding operation, first, the displacement amount of the IC chip 6 and the lead 20 is detected.
[0014]
As shown in FIG. 10, the position of the IC chip 6 in which the plurality of IC chips 6 are aligned and adhered with the conductive bonding material in the longitudinal direction on the lead frame L / F is a predetermined position to be adhered. In some cases, the position is deviated from the position (6 ′ indicated by a broken line in FIG. 10 is a predetermined position of the IC chip 6, and the above-described first reference point a and second reference point b are also pre- Exists as a fixed point). Further, when the lead frame L / F is transported onto the bonding stage 7 by the transport device 5, the position of the lead frame L / F on the bonding stage 7 may vary in the X direction.
[0015]
For this reason, before performing the wire bonding operation, the positions of two fixed points on the IC chip 6 set by self-teach are detected, and the amount of deviation of the IC chip 6 from the predetermined position is calculated.
[0016]
The displacement amount of the IC chip 6 is calculated by moving the camera 1 mounted on the XY table 4 to the first reference point a and the second reference point b, and after the movement of the XY table 4 is completed, the camera 1 uses the IC chip 6. The image signal is input to the image processing device 30 to perform image recognition, and fixed points on the IC chip 6 from the first reference point a and the second reference point b (a ′, b shown in FIG. 10). Each deviation amount up to ') (ΔXa, ΔYa and ΔXb, ΔYb in FIG. 10) is obtained. The position of the pad 6a to be bonded of the IC chip 6 is calculated by calculating the bonding position coordinate of each pad 6a stored in advance based on the deviation amount data.
[0017]
Further, the position of the lead 20 serving as the second bonding point is also detected by detecting the position of c ′, which is a fixed point on the lead frame L / F, and calculating a deviation amount from a predetermined position on the lead frame L / F. To do. That is, the amount of deviation of the lead frame L / F is determined by moving the camera 1 mounted on the XY table 4 to the third reference point c set in advance by self-teaching and moving the lead frame L / F from the third reference point c. The amount of deviation up to c ′, which is a fixed point on F, is obtained. Based on this deviation amount, the bonding position coordinates of the lead 20 stored in advance are calculated to determine the position of the lead 20.
[0018]
After detecting the positions of the pads 6a and the leads 20 of the IC chip 6 described above, the XY table 4 is operated, and the capillary 2a in which a wire having a ball formed at the tip of the bonding arm 2 is inserted is based on the bonding position coordinates. Positioning is performed immediately above the pad 6a, the bonding arm 2 is driven by the bonding head 3 shown in FIG. 9, the capillary 2a is lowered, and the ball on the pad 6a is crushed to perform thermocompression bonding. At this time, the capillary 2a is also excited using an ultrasonic excitation means (not shown).
[0019]
When the connection to the first bonding point is completed, the ascending / descending operation of the bonding arm 2 and the operation of the XY table 4 are performed in a timely manner, and the wire is drawn according to a predetermined loop control. Bonding to the upper second bonding point is performed, and the wire is pressed onto the lead 20. Thereafter, the wire is cut in the process of raising the bonding arm 2 to a predetermined height, and the connection between the pair of pads 6a and the leads 20 is completed. Thereafter, the above-described series of operations is repeated for each pad 6a provided on the IC chip 6 and each lead 20 disposed corresponding to the pad 6a.
[0020]
[Problems to be solved by the invention]
As described above, in the conventional wire bonding apparatus, when performing wire bonding, the first reference point a, the second reference point b, and the third reference point c, which are set in advance by self-teaching, are set to the XY table. After the camera 1 mounted on 4 is moved and the movement of the XY table 4 is completed, the camera 1 images the IC chip 6 and the lead frame L / F, which are parts to be bonded, and the image signal is sent to the image processing device 30. The input image is processed and the fixed points on the IC chip 6 (in this case, a ′ and b ′) and the lead frame from the reference points of the first reference point a, the second reference point b, and the third reference point c. Each deviation amount up to a fixed point on L / F (in this case, c ′) is obtained, and the bonding position coordinates of the pad 6a and the lead 20 stored in advance are corrected based on the deviation amount, and each corrected amount is corrected. Pack Wire bonding connection to the location and position of each lead 20.
[0021]
However, when fixed points on the IC chip 6 (in this case, a ′ and b ′) are out of the field of view of the camera 1, or near fixed points on the surface of the IC chip 6 (in this case, a ′ and b ′). If the contrast of the pattern changes and the image of the camera 1 is different from the reference pattern (in this case, the window 9b), up to a fixed point (in this case, a ′ and b ′) on the IC chip 6 by the image processing device 30. In some cases, the amount of deviation cannot be detected. That is, when the contrast of the pattern near the fixed point on the surface of the IC chip 6 is remarkably changed, the image processing apparatus 30 cannot recognize it because the identity with the reference pattern is lost. Therefore, when the image processing apparatus 30 cannot detect such a deviation amount, the wire bonding apparatus issues an error signal to the outside and stops its operation. As an error process in this case, the operator operates the manipulator 17 to align the fixed points that could not be detected.
[0022]
However, for example, the operator may forget the alignment position of the pad, which is a fixed point on the IC chip 6, or may align with another pad instead of the designated pad. In particular, when the operator changes, such a situation is likely to occur, and if the operator aligns with a pad other than the one specified, an incorrect amount of displacement is detected and the position of the pad is not accurately calculated. The position may deviate from the center of the pad, and the ball and the wiring pattern of the IC chip 6 may be short-circuited to cause a defect in the IC chip.
[0023]
Therefore, the present invention displays an image of a fixed point on the IC chip stored in advance at the time of alignment on the monitor as a reference image, so that the operator can perform alignment at an accurate position while viewing the reference image. An object is to provide an apparatus.
[0024]
[Means for Solving the Problems]
  The bonding apparatus according to the present invention includes a bonding unit that performs bonding on a component to be bonded, a positioning unit that moves the bonding unit relative to the component to be bonded two-dimensionally, and a positioning unit.MountedAn image pickup means for picking up an image of the part to be bonded, an image cutout means for cutting out an image pickup signal from the image pickup means as image data, and an image storage for receiving the image data from the image cutout means and storing an image of the part to be bonded A bonding apparatus comprising: means; image superimposing means for superimposing image data read from the image storage means on an imaging signal from the imaging means; and display means for displaying a video signal from the image superimposing means,At the time of self-teaching, the positioning means stores the position of the alignment point set on the part to be bonded in order to detect the shift amount of the part to be bonded as a reference point, and the image storage means stores the reference point.Storing the image data cut out by the image cutout means from the image pickup signal of the image pickup means at a reference image,When bonding the same kind of parts to be bonded to the reference image stored in the image storage means, the positioning means is used as the reference point.The image superimposing means superimposes the reference image stored in the image storage means on the image pickup signal from the image pickup means and outputs the image to the display means.
[0025]
  Further, the image cut-out means of the bonding apparatus according to the present invention is provided by the imaging means.The alignment point on the part to be bondedThe specified range is cut out as image data from the image pickup signal including.
[0026]
  Further, the image storage means of the bonding apparatus according to the present invention is capable of performing self-teaching.The reference point of the positioning meansA mark for alignment is attached to the image data cut out by the image cutout means from the image pickup signal of the image pickup means and stored as a reference image.
[0027]
Further, the image superimposing means of the bonding apparatus according to the present invention displays the reference image stored in the image storage means at a designated position of the display means.
[0028]
  In addition, the bonding apparatus according to the present inventionThe alignment point on the part to be bondedAn image signal from the imaging means at a position aligned with the image data is converted into image data, and the converted image data;The reference image stored in the image storage meansAnd a coincidence degree detecting means for detecting the coincidence degree.
[0029]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of a bonding apparatus according to the present invention will be described below with reference to the drawings. Parts having the same configuration and function as those of the conventional wire bonding apparatus shown in FIGS. 9 and 10 will be described using the same reference numerals. 1 is a block diagram showing a configuration of a bonding apparatus according to the present invention, FIG. 2 is a block diagram showing a circuit configuration of the image recognition apparatus shown in FIG. 1, FIG. 3 is a block diagram showing a configuration of an image superimposing circuit, and FIG. FIG. 4 is a diagram showing a relationship between a control signal for controlling a switch circuit of an image superimposing circuit on a monitor display area of a monitor and an analog signal of a D / A converter displayed on the monitor.
[0030]
  As shown in FIG. 1, a bonding apparatus according to the present invention has a lens 1b attached to the tip and a camera head 1a with a built-in image pickup device, and a camera 1 as an image pickup means for picking up an image of a part to be bonded. , A bonding head 3 as a bonding means including a capillary 2a attached to the tip of the bonding arm 2, and an XY table as a positioning means capable of moving the camera 1 and the bonding head 3 in the two-dimensional directions of the X direction and the Y direction. 4 and a transfer device 5 that transfers a lead frame L / F mounted with an IC chip 6 as a part to be imaged by the camera 1 to the bonding stage 7, and an image that receives an output from the camera 1 and performs image recognition. An image recognition device 8 as a recognition means and an output from the image recognition device 8 A monitor 9 as a display means, a microprocessor 10 for generating a control signal to a drive device 11 as a drive means, and a control device 10 including a memory (storage device) for storing information, and the XY table 4 are manually moved. A signal for output to the control device 10manipulator17 and a driving device 11 as a driving means for issuing a driving signal to the bonding head 3 and the XY table 4 in response to a command signal from the control device 10, and an operation switch 18 is provided in the control device 10. It is connected.
[0031]
As shown in FIG. 2, the image recognizing device 8 sends a camera control signal such as a horizontal and vertical synchronization signal to the camera 1 by a clock signal generation circuit 8a and a clock from the clock signal generation circuit 8a and a signal from the control circuit 8f. A camera control signal generation circuit 8b for output, an amplifier 8c for amplifying an imaging signal from the camera 1, and a converter 8e for sampling a signal output from the amplifier 8c and converting it into a multivalued digital value (image data). And a range designated from the image data output from the converter 8e (for example, according to the embodiment of the present invention, the horizontal and vertical cutout start time and cutout end time specified by the control circuit 8f). Image data output from the converter 8e is cut out. Image cutout as image cutout means for cutting out image data An image processing circuit 8d that detects a deviation amount by performing image recognition such as matching between the path 8k, image data output from the converter 8e, and a standard pattern, and data and IC of the reference image cut out by the image cut-out circuit An image memory 8g as image storage means for storing a reference pattern for detecting a deviation amount of a fixed point such as the chip 6, an image memory control circuit 8q for controlling writing and reading of the image memory 8g, and an image processing circuit 8d. A control circuit 8f incorporating a microcomputer for controlling the camera control signal generation circuit 8b, the image memory 8g, etc., and an image superimposing means for superimposing the image data read from the image memory 8g on the video signal from the amplifier 8c. Display control for switching the display signal to the monitor 9 by the control signal from the image superimposing circuit 8p and the control circuit 8f And road 8m, consisting output circuit 8h communicating with the control device 10.
[0032]
As shown in FIG. 3, the image superimposing circuit 8p includes a switch circuit and a D / A converter. The D / A converter converts image data read from the image memory 8g into an analog signal, and inputs the switch circuit. Output to terminal (B). The video signal from the amplifier 8c is input to one input terminal (A) of the switch circuit. The switch circuit selects the input signals of the input terminals (A) and (B) by the control signal input from the image memory control circuit 8q to the input terminal (C) and outputs the signal to the output terminal (O). It is configured.
[0033]
4 shows the relationship between the control signal for controlling the switch circuit of the image superimposing circuit 8p on the monitor display area of the monitor 9 and the analog signal of the D / A converter displayed on the monitor 9. In FIG. As shown in FIG. 4, a high level signal '1' is supplied between the time Ths in the horizontal control signal as the control signal and between the time Tvs in the vertical control signal and the input terminal ( By inputting to C), the analog signal of the reference image on the image memory 8g is output from the switch circuit.
[0034]
Further, by changing the time from Ths to The in the horizontal control signal and the time from Tvs to Tve in the vertical control signal, the reference image read from the image memory 8g can be displayed at an arbitrary position in the monitor display area. it can. The control for displaying the reference image at an arbitrary position on the monitor display area of the monitor 9 is such that the control circuit 8f of the image recognition device 8 receives a control signal from the control device 10 by operating the operation switch 18, and the control circuit A control signal is output to the image memory control circuit 8q from 8f and is performed by the image memory control circuit 8q.
[0035]
As shown in FIG. 2, the image processing circuit 8d of the image recognition device 8 can perform matching between the image data output from the converter 8e and the reference image data stored in the image memory 8g. Therefore, the degree of coincidence can be detected by the matching process between the image data of the imaging signal from the camera 1 and the reference image data stored in the image memory 8g by the image processing circuit 8d.
[0036]
Further, the memory of the control device 10 shown in FIG. 1 incorporates a control program that controls each operation such as self-teaching and displacement detection described below.
[0037]
  The self-teach for setting various conditions for detecting the amount of deviation of a fixed point of the IC chip 6 etc. in the bonding apparatus according to the present invention will be described below. FIG. 5 is a flowchart showing the flow of self-teach for setting conditions for detecting the amount of deviation of the fixed point of the IC chip. It should be noted that the detection of the shift amount of the fixed point of the IC chip 6 or the like of the bonding apparatus according to the present invention can be performed by a full auto mode in which the shift amount is automatically detected by the image recognition device 8 or by an operator.manipulatorIt is possible to perform the operation in a semi-auto mode in which the amount of deviation is detected by operating 17. Hereinafter, the automatic detection of the shift amount by the image recognition device 8 is referred to as a full auto mode, and the operatormanipulatorThe detection of the shift amount by operating 17 is referred to as a semi-auto mode.
[0038]
  First, the operator visually observes an image based on an imaging signal from the camera 1 on the monitor 9.manipulator17 is moved to move the XY table 4 so that the intersection point O of the cross line 9a provided on the screen of the monitor 9 is set as a fixed point on the IC chip 6 for semi-auto mode (see FIG. 8). A matching is made to (a) shown (step S1 in FIG. 5).
[0039]
As shown in FIG. 8, if the semi-auto mode first reference point at the position of the XY table 4 shown in FIG. 1 is a, this corresponds to the first alignment point as a fixed point on the IC chip 6, and The second reference point b for the semi-auto mode corresponds to a second alignment point as a fixed point on the IC chip 6. The first reference point a and the second reference point b for the semi-auto mode are used as position coordinates on the XY table 4 and are different from the reference pattern shown on the window 9b of the monitor 9 shown in FIG. .
[0040]
As shown in FIG. 5, after completion of the alignment of the first alignment point (a shown in FIG. 8), the operation switch 18 shown in FIG. 1 is pressed to notify the controller 10 of the completion of alignment. After confirming that the operation switch 18 has been pressed, the control device 10 stores the position coordinates of the XY table 4 in the memory in the control device 10 as a semi-automatic first reference point (a shown in FIG. 8). Further, the image in the window 9b on the monitor 9 of the first semi-automatic reference point (a shown in FIG. 8) is used as the reference image of the first alignment point (a shown in FIG. 8) as the image memory 8g of the image recognition device 8. (Step S2). Then, the control circuit 8f shown in FIG. 2 writes alignment mark data in the image memory 8g with the position corresponding to the intersection O of the cross line 9a of the reference image stored in the image memory 8g as the center (step S3). .
[0041]
Next, while manipulating the manipulator 17 while observing the image based on the imaging signal from the camera 1 on the monitor 9, the XY table 4 is moved so that the intersection point O of the cross line 9 a provided on the screen of the monitor 9 is full. The first detection point (D shown in FIG. 8) as a fixed point on the IC chip 6 for auto mode is aligned (step S4).
[0042]
  In full auto modeAs shown in FIG. 8, the window 9b on the screen of the monitor 9 is positioned by moving the XY table 4 within the frame of each side surrounding the outer periphery of the IC chip 6, and the intersection O of the cross line 9a of the window 9b isThe position of the XY table 4As the first reference point for full auto mode,Position of the IC chip 6 at the intersection O of the cross line 9aIs a first detection point D as a fixed point on the IC chip.Also, as shown in FIG.The window 9b on the screen of the monitor 9 is positioned by moving the XY table 4 within the frame of each side surrounding the outer periphery of the IC chip 6, and the intersection point O of the cross line 9a of the window 9b is set.The position of the XY table 4The second reference point for full auto modePosition of the IC chip 6 at the intersection O of the cross line 9aIs a second detection point E as a fixed point on the IC chipIt is said.That is,Alignment points as fixed points for miauto modeThe difference betweenAs shown in FIG. 8, the detection points as fixed points for the full auto mode areThe frame of the window 9b is in the frame of each side that surrounds the outer periphery of the IC chip 6.It is set.This is detected by the influence of the adhesive or the like to which the IC chip 6 is attached when part or all of the window 9b is set to protrude from the frame of each side surrounding the outer periphery of the IC chip 6. This is to avoid affecting the accuracy.
[0043]
  Next, as shown in FIG. 5, the first detection point (D shown in FIG. 8)Completion of alignmentLater, the operation switch 18 is pressed to notify the controller 10 of the completion of alignment. After confirming that the operation switch 18 has been pressed, the control device 10 uses the position coordinates of the XY table 4 as the first reference point for full auto mode (D shown in FIG. 8) in the memory in the control device 10, and The image in the window 9b on the monitor 9 at the first reference point for full auto mode (D shown in FIG. 8) is stored as a reference pattern in the image memory 8g of the image recognition device 8 (step S5). As shown in FIG. 8, the first alignment point a for the semi-auto mode and the first detection point D for the full-auto mode are set at different positions, but this is the same on the IC chip 6. It is also possible to set a point (position). The same applies to the second alignment point b for the semi-auto mode and the second detection point E for the full-auto mode.
[0044]
  Next, the operator moves the XY table 4 by operating the manipulator 17 while visually observing the image based on the imaging signal from the camera 1 on the monitor 9, and the intersection of the cross lines 9 a provided on the screen of the monitor 9. O is aligned with a second alignment point (b shown in FIG. 8) as a fixed point on the IC chip 6 for semi-auto mode (step S6). Of the second alignment point (b shown in FIG. 8)Completion of alignmentLater, the operation switch 18 is pressed to notify the control device 10 of completion of alignment. After confirming that the operation switch 18 has been pressed, the control device 10 stores the position coordinates of the XY table 4 in the memory within the control device 10 as a semi-automatic second reference point (b shown in FIG. 8). Further, the image in the window 9b on the monitor 9 of the semi-automatic second reference point (b shown in FIG. 8) is used as the reference image of the second alignment point (b shown in FIG. 8) as the image memory 8g of the image recognition device 8. (Step S7). Then, the control circuit 8f shown in FIG. 2 writes alignment mark data in the image memory 8g with the position corresponding to the intersection O of the cross line 9a of the reference image stored in the image memory 8g as the center (step S8). .
[0045]
  Next, while manipulating the manipulator 17 while observing the image based on the imaging signal from the camera 1 on the monitor 9, the XY table 4 is moved so that the intersection point O of the cross line 9 a provided on the screen of the monitor 9 is full. The second detection point (E shown in FIG. 8) as a fixed point on the IC chip 6 for auto mode is adjusted (step S9). Of the second detection point (E shown in FIG. 8) for full auto modeCompletion of alignmentLater, the operation switch 18 is pressed to notify the controller 10 of the completion of alignment. After confirming that the operation switch 18 has been pressed, the control device 10 uses the position coordinates of the XY table 4 as the second reference point for full auto (E shown in FIG. 8) in the memory in the control device 10, and The image in the window 9b on the monitor 9 at the second reference point (E shown in FIG. 8) for the auto mode is stored as a reference pattern in the image memory 8g of the image recognition device 8 (step S10).
[0046]
With the above operation, the self-teach relating to the setting of the fixed point detection data of the IC chip 6 in the semi-auto mode and the full-auto mode is completed.
[0047]
  Next, the operator moves the XY table 4 by operating the manipulator 17 while visually observing the image based on the imaging signal from the camera 1 on the monitor 9, and the intersection of the cross lines 9 a provided on the screen of the monitor 9. Align O with the third alignment point (c shown in FIG. 8) as a fixed point on the lead for semi-auto mode. Of the third alignment point (c shown in FIG. 8)Completion of alignmentLater, the operation switch 18 is pressed to notify the control device 10 of completion of alignment. After confirming that the operation switch 18 has been pressed, the control device 10 stores the position coordinates of the XY table 4 in the memory in the control device 10 as a semi-automatic third reference point (c shown in FIG. 8). In addition, the image in the window 9b on the monitor 9 of the semi-automatic third reference point (c shown in FIG. 8) is used as the reference image of the third alignment point (c shown in FIG. 8). Is remembered. Then, the control circuit writes the alignment mark data in the image memory 8g with the position corresponding to the intersection O of the cross line 9a of the reference image stored in the image memory 8g as the center.
[0048]
  Next, while visually observing the image based on the imaging signal from the camera 1 on the monitor 9manipulator17 is moved to move the XY table 4, and a third detection point (F shown in FIG. 8) is defined as a fixed point on the lead for the full auto mode with the intersection O of the cross line 9a provided on the screen of the monitor 9. ). Of the third detection point (F shown in FIG. 8)Completion of alignmentLater, the operation switch 18 is pressed to notify the controller 10 of the completion of alignment. As shown in FIG. 8, the third detection point (F shown in FIG. 8) as a fixed point on the lead for the full auto mode is also shown in FIG.An image in the window 9b is stored as a reference pattern.
[0049]
After confirming that the operation switch 18 has been pressed, the control device 10 uses the position coordinates of the XY table 4 as the third reference point for full auto mode (F shown in FIG. 8) in the memory in the control device 10, and Images in the window 9b on the monitor 9 at the third reference point for full auto mode (F shown in FIG. 8) are respectively stored in the image memory 8g of the image recognition device 8 as a reference pattern.
[0050]
Next, the manipulator 17 is operated to the intersection O of the cross line 9a provided on the screen of the monitor 9 to move the XY table 4 to a predetermined position on the lead 20 or the pad 6a, that is, a position where bonding is to be performed. When the alignment is completed as accurately as possible, the position of the XY table 4 is stored in the memory in the control device 10 as the position coordinates of the bonding point.
[0051]
Thereafter, a predetermined number or all of the pads 6a and the leads 20 are aligned, and the position coordinates of the bonding points are stored in the memory in the control device 10.
[0052]
With the above, self-teaching such as setting of position coordinates and setting of image data for performing the wire bonding operation is completed.
[0053]
Next, the detection of the shift amount by the operator at the time of error stop in the detection of the shift amount in the full auto mode in the wire bonding operation by the bonding apparatus will be described with reference to the flowchart shown in FIG.
[0054]
As shown in FIG. 6, the amount of deviation of the IC chip 6 is detected by moving the camera 1 mounted on the XY table 4 to the first reference point for full auto mode (D shown in FIG. 8) (step S20). After the movement of the XY table 4 is completed, the IC chip 6 is imaged by the camera 1 and the imaged signal is input to the image recognition device 8 (step S21). The image recognizing device 8 converts the image pickup signal from the camera 1 into image data, and performs an image processing for matching processing between the converted image data and the reference pattern of the first reference point for full auto mode (D shown in FIG. 8). Performed by the circuit 8d (shown in FIG. 2), the amount of deviation from the first reference point for full auto mode (D shown in FIG. 8) is calculated (step S22). The phenomenon of deviation in this case is when the IC chip 6 'is displaced as shown in FIG. 10, as in the case of the IC chip 6, and the amount of deviation in the case of this deviation is calculated.
[0055]
Next, it is determined whether or not the matching rate in the matching process in step S22 is greater than or equal to a predetermined reference value (step S23). If the matching rate is equal to or greater than a predetermined reference value, it is determined that the detection of the deviation amount is normal, the detected deviation amount is stored (step S24), and the camera 1 mounted on the XY table 4 is stepped. Move to the second reference point (E shown in FIG. 8) for full auto mode in S32. If the matching rate is less than the predetermined reference value, it is determined that the deviation amount is abnormally detected, an error signal is output, and the operation is stopped (step S25).
[0056]
Next, the operator cancels the error signal output from the bonding apparatus and operates the operation switch 18 to switch the detection mode from the full auto mode to the semi-auto mode (step S26).
[0057]
When the bonding apparatus is switched to the semi-auto mode, the camera 1 mounted on the XY table 4 moves from the first reference point for full auto mode (D shown in FIG. 8) to the first reference point for semi-auto (a shown in FIG. 8). (Step S27). After the movement of the XY table 4 is completed, the image recognition device 8 reads the reference image of the first alignment point (a shown in FIG. 8) stored in the image memory 8g, and the video signal from the camera 1 is read by the image superimposing circuit 8p. Is superimposed and output to the display control circuit 8m, and an image with the reference image superimposed is displayed on the monitor 9 (step S28). FIG. 7 is a diagram illustrating an example in which an image on which a reference image is superimposed is displayed on a monitor. The reference image can be displayed at an arbitrary position on the monitor 9 by operating the operation switch 18.
[0058]
Next, the operator operates the manipulator 17 while viewing the reference image on the monitor 9 to move the XY table 4 and sets the intersection point O of the cross line 9a provided on the screen of the monitor 9 to the first alignment point. (A) shown in FIG. 8 is aligned (step S29). The operator operates the operation switch 18 and presses the alignment completion switch. After the switch is pressed, the image processing circuit 8d of the image recognition device 8 stores the image data output from the converter 8e and the image memory 8g. Matching with the image data of the reference image of the first reference point for semi-auto mode (a shown in FIG. 8), the image data of the imaging signal from the camera 1 and the first reference point for semi-auto mode stored in the image memory 8g The degree of coincidence with the image data of the reference image in (a) shown in FIG. 8 is detected. The detected degree of coincidence is displayed on the monitor 9 (step S30). At this time, the degree of coincidence may be output to the control device 10 to determine whether the degree of coincidence is greater than or equal to a reference value. If the degree of coincidence is less than the reference value, the operator may be warned.
[0059]
The control device 10 stores the movement amount of the XY table 4 from the first reference point for semi-auto mode (a shown in FIG. 8) as a deviation amount (step S31).
[0060]
Next, the camera 1 mounted on the XY table 4 moves to the second reference point for semi-auto mode (b shown in FIG. 8). In the case of transition from step S24, the process moves to the second reference point for full auto mode (E shown in FIG. 8) (step S32). After the movement of the XY table 4, the operation switch 18 is used to switch to the full auto mode, and the shift amount detection operation in the full auto mode is resumed. Further, in the semi-auto mode, the operator operates the manipulator 17 while looking at the reference image on the monitor 9 to move the XY table 4 so that the intersection of the cross lines 9a provided on the screen of the monitor 9 is the second alignment point. (B shown in FIG. 8) may be matched.
[0061]
The position of the pad 6a to be bonded of the IC chip 6 is calculated by calculating the bonding position coordinate of each pad 6a stored in advance based on the deviation amount data.
[0062]
Further, the position of the lead 20 serving as the second bonding point is also detected by detecting the position of one fixed point on the lead frame L / F, and the amount of deviation from a predetermined position on the lead frame L / F is calculated. Based on the calculated deviation amount, the bonding position coordinates of the lead 20 stored in advance are calculated to obtain the position of the lead 20.
[0063]
Based on the calculated position coordinates of the pad 6a and the lead 20, the wire bonding operation is performed on each pad 6a provided on the IC chip 6 and each lead 20 disposed corresponding to the pad 6a.
[0064]
As described above, when detection is not possible in the full auto mode, switching to the semi-auto mode makes it possible for the operator to make a match while looking at the reference image and aligning the correct position.
[0065]
Although the bonding apparatus according to the present invention has been described with respect to the wire bonding apparatus, it can also be applied to the detection of the position of an IC chip, a lead on a tape carrier, etc. in the tape bonding apparatus.
[0066]
【The invention's effect】
As described above, according to the bonding apparatus of the present invention, an image in the vicinity of a fixed point to be aligned of the parts to be bonded is registered as image information in advance, and the fixed point of the bonded parts is registered using the image information. By displaying the registered image information on the monitor at the time of alignment, the operator can accurately perform alignment with reference to the displayed image, so that it is possible to prevent the occurrence of bonding failure.
[0067]
In addition, according to the bonding apparatus of the present invention, even if the operator changes, it is possible to accurately perform alignment with reference to the displayed image, so that the operating rate of the bonding apparatus is improved, and the semiconductor device in the bonding process The number of production can be increased.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of a bonding apparatus according to the present invention.
2 is a block diagram showing a circuit configuration of the image recognition apparatus shown in FIG. 1. FIG.
FIG. 3 is a block diagram illustrating a configuration of an image superimposing circuit of the image recognition apparatus.
FIG. 4 is a diagram illustrating a relationship between a control signal for controlling a switch circuit of an image superimposing circuit and an analog signal of a D / A converter displayed on a monitor.
FIG. 5 is a diagram showing a self-teach flowchart for setting conditions for detecting a fixed point deviation amount of an IC chip;
FIG. 6 is a flowchart illustrating detection of a deviation amount by an operator when an error is stopped in detecting a deviation amount in the full auto mode.
FIG. 7 is a diagram illustrating an example in which an image on which a reference image is superimposed is displayed on a monitor.
FIG. 8 shows the position of the IC chip attached to the lead frame,Alignment and detection points in self-teachFIG.
FIG. 9 is a block diagram showing a configuration of a conventional wire bonding apparatus.
FIG. 10 is a diagram showing the position of the IC chip attached to the lead frame and showing the amount of deviation of the fixed point of the IC chip from the reference point.
[Explanation of symbols]
L / F Lead frame
1 Camera
1a Camera head
1b Optical lens (lens)
2 Bonding arm
2a Capillary
3 Bonding head
4 XY table
5 Transport device
6 IC chip
6a pad
7 Bonding stage
7a heater
8 Image recognition device
8a Clock signal generation circuit
8b Camera control signal generation circuit
8c amplifier
8d image processing circuit
8e converter
8f control circuit
8g image memory
8h I / O circuit
8k image cropping circuit
8m display control circuit
8p image superposition circuit
8q image memory control circuit
9 Monitor
9a Cross line
9b wind
10 Control device
11 Drive device
14 Land
17manipulator
18 Operation switch
20 leads
30 Image processing device

Claims (5)

A bonding means for bonding to a part to be bonded;
Positioning means for positioning by moving the bonding means relative to the part to be bonded two-dimensionally;
An imaging means mounted on the positioning means for imaging the part to be bonded;
Image cutout means for cutting out an image pickup signal from the image pickup means as image data;
Image storage means for receiving image data from the image cutout means and storing an image of the part to be bonded;
Image superimposing means for superimposing the image data read from the image storage means on the imaging signal from the imaging means;
A bonding apparatus comprising display means for displaying a video signal from the image superimposing means,
At the time of self-teaching, the positioning means stores the position of the alignment point set on the part to be bonded in order to detect the amount of deviation of the part to be bonded as a reference point, and the image storage means stores the reference point at the reference point . Storing the image data cut out by the image cutout means from the image pickup signal of the image pickup means as a reference image;
After the positioning means has moved to the reference point during bonding of the same kind of parts to be bonded as the reference image stored in the image storage means, the image superimposing means adds the image storage means to the image pickup signal from the image pickup means. A bonding apparatus that superimposes the reference image stored in the image and outputs the superimposed image to the display means. The bonding apparatus according to claim 1, wherein the image cutout unit cuts out a specified range as image data from an image pickup signal including the alignment point on the part to be bonded from the image pickup unit. The image storage means attaches an alignment mark to the image data cut out by the image cutout means from the image pickup signal of the image pickup means at the reference point of the positioning means during self-teaching and stores it as a reference image The bonding apparatus according to claim 1.   The bonding apparatus according to claim 1, wherein the image superimposing unit displays the reference image stored in the image storage unit at a specified position of the display unit. An imaging signal from the imaging unit at a position aligned with the alignment point on the part to be bonded at the time of bonding is converted into image data, the converted image data, and the reference stored in the image storage unit The bonding apparatus according to claim 1, further comprising a coincidence degree detecting unit that detects a coincidence degree with the image .

Images