JP3564332B2 - Bonding equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a bonding apparatus used in an assembly process of a semiconductor device, and in particular, with respect to capturing an image of a part to be bonded by an imaging unit, pads (electrodes) on an IC chip and leads to which the IC chip is attached. The present invention relates to a bonding apparatus capable of detecting a deviation amount of an IC chip before bonding and detecting a position of a lead in a bonding apparatus that connects external leads formed on a frame or the like.
[0002]
[Prior art]
Conventionally, a wire bonding apparatus shown in FIG. 7 is known as a bonding apparatus for connecting pads (electrodes) on an IC chip and external leads.
[0003]
As shown in FIG. 7, the wire bonding apparatus includes a camera 1 as an image pickup means including a camera head 1a, an optical lens 1c (hereinafter referred to as a lens), a bonding arm 2 having a capillary 2a attached to the tip, A bonding head 3 for driving the bonding arm 2 up and down, a bonding means composed of the bonding arm 2 and the bonding head 3, and a camera 1 as the imaging means are mounted and moved two-dimensionally in the X and Y directions. It has an XY table 4 as positioning means for positioning, and a transfer device 5 having a bonding stage 7 for performing a bonding operation by the bonding head 3 including the capillary 2a and the bonding arm 2 and the like. The bonding stage 7 has a heater 7a for heating the lead frame and the like.
[0004]
As shown in FIG. 7, the wire bonding apparatus further includes an image processing device 30 that receives a video signal from the camera 1, a monitor 9 that receives an output from the image processing device 30, and a control device including a microprocessor. 10 and a driving device 11 that issues a driving signal to the bonding head 3 and the XY table 4 in response to a command signal from the control device 10.
[0005]
In the wire bonding apparatus, at the start of work, the lead frame L \ F on which a plurality of IC chips 12 are arranged and adhered in the longitudinal direction is carried onto the bonding stage 7 heated by the transfer device 5 and the earliest IC chip is loaded. 12 is positioned at the bonding work position.
[0006]
Then, the bonding arm 2 and the XY table 4 are operated by the control device 10 and the driving device 11 to perform the bonding work on the earliest IC chip 12.
[0007]
As shown in FIG. 9, the IC chip 12 is square, for example, and a large number of pads 12a are arranged in parallel along the outer periphery of the upper surface at predetermined intervals, and land portions 14 formed on the lead frame L \ F (FIG. 9). Is attached). The lead frame L \ F is provided with leads 15 corresponding to the pads 12a.
[0008]
Next, the bonding process will be described. Before that, the 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 12a and leads 15 to be bonded.
[0009]
First, the operator manually operates the XY table 4 using a manipulator (not shown) or the like while visually observing an image based on the video signal from the camera 1 on the monitor 9. Are matched with at least two regular points on the IC chip 12 as the first reference point and the second reference point. At this time, the coordinates of the first reference point and the second reference point are stored in the memory in the control device 10, and the image in the window 9b on the monitor 9 at the first reference point and the second reference point is used as the reference pattern. It is stored in the memory of the processing device 30. Next, it is adjusted to a third reference point as a regular point at one place on the lead frame L / F. At this time, the coordinates of the third reference point are stored in the memory in the control device 10, and the image in the window 9b on the monitor 9 at the third reference point is stored in the memory of the image processing device 30 as a reference pattern.
[0010]
Next, as shown in FIGS. 7 and 9, the intersection of the cross lines 9a provided on the screen of the monitor 9 is set as accurately as possible to a predetermined position on the lead 15 or the pad 12a, that is, a position to be bonded. (Match). The coordinates of the intersection of the cross line 9a can be viewed as coordinates on the XY table 4, and the coordinates of each bonding point are stored when the alignment is completed. By such teaching, the coordinates of the reference bonding point are stored in the memory in advance.
[0011]
Next, the bonding process will be described. In the bonding process, first, the position where the IC chip 12 and the lead 15 are to be bonded is detected.
[0012]
That is, the position of the IC chip 12 on which the plurality of IC chips 12 are arranged and adhered in the longitudinal direction with the conductive bonding material on the lead frame L / F, as shown in FIG. In some cases, the position is shifted from the position (12 ′ indicated by a broken line in FIG. 9 is a predetermined position of the IC chip 12).
[0013]
Therefore, before wire bonding, the first reference point (a in FIG. 9) and the second reference point (b in FIG. 9), which are at least two regular points on the IC chip 12, are placed on the XY table 4. After the mounted camera 1 is moved and the movement of the XY table 4 is completed, the IC chip 12 is imaged by the camera 1, the image signal is input to the image processing device 30 to perform image recognition, and the first stored in advance. Each deviation amount (ΔXa, ΔYa and ΔXb, ΔYb in FIG. 7) from the reference point and the second reference point to the fixed points (a ′, b ′ shown in FIG. 7) on the IC chip 12 is obtained, and this deviation is obtained. Based on the quantity data, the bonding coordinates of each pad 12a stored in advance are calculated, and the position of the pad 12a to be bonded of the IC chip 12 is calculated.
[0014]
The position of the lead 15 serving as the second bonding point is also moved to the third reference point, which is at least one regular point on the lead frame L / F, by moving the camera 1 mounted on the XY table 4 to XY. After the movement of the table 4 is completed, the camera 1 picks up an image, inputs the picked-up image signal to the image processing device 30, performs image recognition, and a fixed point on the lead frame L / F from the third reference point stored in advance (the third point) The position of the lead 15 is calculated by calculating the pre-stored bonding coordinates of the lead 15 based on the amount of deviation.
[0015]
Further, when the number of leads 15 is large and the positions of the leads 15 are varied, the position of each lead 15 is detected by a lead locator (a function for detecting the bonding position of the lead by image recognition) to bond the leads. The coordinates are corrected and the actual position of the lead 15 is obtained.
[0016]
FIG. 8 is a diagram showing an example of the timing of the video signal capturing operation of the camera when detecting the position of the part to be bonded in the conventional bonding apparatus. That is, the figure number is an example of the timing of the video signal capturing operation of the camera of the image processing apparatus 30 in the position detection on the IC chip 12, the position detection on the lead 15, and the position detection of each lead 15 by the lead locator. Is shown.
[0017]
FIG. 8A shows a vertical synchronization signal output from the image processing apparatus 30 to the camera 1.
[0018]
The vertical synchronization signal is constantly output to the camera 1 at a predetermined cycle (16.7 milliseconds). The camera 1 starts image accumulation when the vertical synchronization signal output from the image processing device 30 is “OFF” (time T20, T23, T25 in FIG. 8), and the vertical synchronization signal changes to “ON” (FIG. 8). 8 until the time T22, T24, and T26). Next, the camera 1 outputs the accumulated image signal to the image processing apparatus 30 as a video signal using the next vertical synchronization signal ((c) of FIG. 8).
[0019]
That is, as shown in FIG. 8, the image signals (1), (3), and (5) shown in FIG. 8 accumulated by the camera 1 by the vertical synchronization signal are the video signals (FIG. (2), (4), (6)) shown in FIG.
[0020]
Next, as shown in FIG. 8D, after the XY table 4 moves and stops at the image capturing position (time T21 in FIG. 8), the control device 10 sends the video signal of the camera 1 to the image processing device 30. An image capture command for capturing the image into the memory is issued ((e) of FIG. 8).
[0021]
The image processing apparatus 30 converts the image signal accumulated by the camera 1 in (3) shown in FIG. 8B to the video signal from the camera 1 in the next vertical synchronization signal (shown in FIG. 8C). (4) is converted into a digital value, the video signal is captured and stored in the storage device (memory) of the image processing device 30. Therefore, the image signal (1) shown in FIG. 8B is a video signal in this case because the XY table 4 captures the moving image as shown in FIG. 8D. In (2), image capture is not performed.
[0022]
After the image processing device 30 completes the capture of the image (3) shown in FIG. 8B (image (3) shown in FIG. 8F), the XY table 4 moves to the next detection position. Start. Further, the image processing device 30 processes the image data stored in the memory to perform position detection processing.
[0023]
After detecting the positions of the pad 12a and the lead 15 of the IC chip 12 described above, the bonding arm 2 moves the capillary 2a through which a wire having a ball formed at the tip is inserted, based on the image information from the camera 1. By the operation of the XY table 4, it is positioned directly above the pad 12a.
[0024]
After this positioning is completed, the bonding arm 2 is driven by the bonding head 3 shown in FIG. 7, the capillary 2a is lowered, and the ball 18a on the pad 12a is crushed to perform thermocompression bonding. At this time, the capillary 2a is also excited by an ultrasonic excitation means (not shown).
[0025]
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 18 is pulled out according to a predetermined loop control. Bonding to the second bonding point on 15 is performed.
[0026]
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 12a and the leads 15 is completed.
[0027]
Thereafter, the above-described series of operations are repeated for each pad 12a provided on the IC chip 12 and each lead 15 disposed corresponding to the pad 12a.
[0028]
[Problems to be solved by the invention]
In recent years, the number of leads 15 has increased due to the increase in the number of pins in an IC package, and the operation time of a lead locator for detecting the position of each lead has become longer.
[0029]
For example, when the number of leads 15 in the lead frame L / F is 200, and the number of leads 15 in the imaging range of the camera 1 is 5, in order to capture images of all leads into the image processing apparatus 30, It is necessary to repeat the image capturing operation 40 times. For this reason, it is an issue to shorten the operation time of the read locator by shortening the time of the image capturing operation by the reed locator.
[0030]
However, in the conventional wire bonding apparatus, the image storage start and storage time of the camera 1 are defined by the vertical synchronization signal, and the image capturing operation needs to be performed while taking the timing with the vertical synchronization signal. For this reason, the image capture operation time cannot be shortened below the period of the vertical synchronization signal.
[0031]
Therefore, according to the present invention, when the XY table 4 reaches a predetermined position, the camera image is accumulated, and the accumulation time is varied to accumulate the image in a short time to shorten the image capture time. Accordingly, it is an object to provide a high-speed wire bonding apparatus by shortening the operation time of the position detection and the lead locator.
[0032]
[Means for Solving the Problems]
A bonding apparatus according to the present invention includes a bonding unit that performs bonding to a component to be bonded, a positioning unit that performs positioning relative to the bonding unit and the component to be bonded in a two-dimensional manner, and the positioning unit. In a bonding apparatus comprising: an imaging unit that images the mounted component to be bonded; an image recognition unit that processes a signal from the imaging unit to recognize an image; and a control unit that controls a bonding apparatus. When the positioning means reaches a predetermined position during movement, the image recognition means outputs an image accumulation start signal and an image accumulation time control signal of the bonded parts to the imaging means, and the imaging means Receives the image accumulation start signal output from the image recognition means, and simultaneously receives the image Image output means for starting the product, storing the image for a predetermined time based on the storage time of the image output from the image recognition means, and outputting a video signal to the image recognition means after completion of the image storage. is there.
[0033]
In addition, 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 performs positioning relative to the bonding unit and the component to be bonded in a two-dimensional manner, and the positioning In a bonding apparatus having an image pickup means for picking up an image of the part to be bonded mounted on the means, an image recognition means for processing a signal from the image pickup means to recognize an image, and a control means for controlling the bonding apparatus The image recognizing unit outputs an image accumulation start signal and an image accumulation time control signal of the bonding target component to the imaging unit after the positioning unit is stopped at a predetermined position. When the image accumulation start signal output from the image recognition means is received, the image is accumulated at the same time. The image is accumulated for a predetermined time based on the accumulation time of the image output from the image recognition means, and after the image accumulation is completed, a video signal is output from the image output means to the image recognition means. The image pickup means starts moving after image storage is completed.
[0034]
Further, in the bonding apparatus according to the present invention, the image recognition means outputs an image accumulation start signal and an image accumulation time to the image pickup means, and at the same time, starts and is lit on the illumination means for illuminating the parts to be bonded. A signal for controlling the brightness of the image pickup device is output, and illumination is performed by the illumination means during the image accumulation period of the image pickup means and with a predetermined brightness.
[0035]
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 bonding apparatus shown in FIG. 7 will be described using the same reference numerals.
[0036]
As shown in FIG. 1, a bonding apparatus according to the present invention controls an imaging device 25 as an imaging means provided with a CCD camera 25a, a lens 1c, etc., an illumination lamp 20a for illuminating a part to be bonded, and the illumination lamp 20a. An illumination device 20 as an illumination means comprising an illumination control device 20b, a bonding head 3 including a capillary 2a attached to the tip of the bonding arm 2, the imaging device 25, the illumination lamp 20a and the bonding head 3 in the X direction and Transport for transporting a lead frame L / F carrying an XY table 4 as positioning means movable in a two-dimensional direction in the Y direction and an IC chip 12 as a semiconductor component imaged by the imaging device 25 to the bonding stage 7 A video signal from the conveying device 5 as a means and the imaging device 25. An image recognition device 8 as an image recognition means, a monitor 9 as a display means for receiving an output from the image recognition device 8, a microprocessor for generating a control signal to a drive device 11 as a drive means, and information stored therein And a drive device 11 as a drive means for issuing a drive signal to the bonding head 3 and the XY table 4 in response to a command signal from the control device 10.
[0037]
Below, the detail of a structure of each apparatus of a bonding apparatus is demonstrated.
[0038]
The XY table 4 as positioning means is provided with servo motors (not shown) for driving the X axis and the Y axis, respectively, and the rotation of the servo motor is converted into a linear motion by a ball screw (not shown). It is configured to be movable in the direction. Further, a rotary encoder (not shown) as position detecting means for outputting a two-phase signal (this two-phase signal is A phase and B phase) according to the rotation angle of the servo motor is built in the servo motor. ing. The A-phase and B-phase signals output from the rotary encoder are converted into UP or DOWN pulse signals by the signal converter 11a of the driving device 11 shown in FIG. The UP or DOWN pulse signal converted by the signal converter 11a is input to the counter circuit 11b of the driving device 11 shown in FIG. 4, and the number of pulses is counted by the counter circuit 11b. That is, the position of the XY table 4 can be managed by the count data of the counter circuit 11b. Further, the drive device 11 includes a coincidence detection circuit 11c that detects whether or not the target position has been reached when the XY table 4 is moved. The coincidence detection circuit 11c is configured to output a coincidence signal to the control device 10 when the target position data output from the control device 10 and the count data of the counter circuit 11b coincide.
[0039]
The imaging device 25 as the imaging means includes at least an optical lens 1c and a CCD camera 25a, and a solid-state imaging device 1aa is built in the CCD camera 25a as shown in FIG. The solid-state imaging device 1aa photoelectrically converts light energy into an electric signal, and outputs a charge accumulated in the photosensitive accumulation unit 1ab and a photosensitive accumulation unit 1ab that temporarily accumulates the electric charge as the converted electric signal. A charge transfer unit 1ac composed of a CCD (Charge Coupled Device) for transfer to the unit, and an output unit 1ad for converting the charge from the charge transfer unit 1ac into a voltage signal. Note that the charge transfer unit 1ac in FIG. 3 transfers interline transfer CCDs, that is, charges based on signals photoelectrically converted by the photosensitive storage unit 1ab to the vertical register Vr, and then transfers them in the vertical direction, from the horizontal register Hr. The charge is read out line by line. The solid-state imaging device 1aa also includes a clock control unit 1ae that supplies a driving clock to the photosensitive storage unit 1ab, the charge transfer unit 1ac, and the like.
[0040]
As shown in FIG. 3, the electrical signal obtained by the solid-state imaging device 1aa is proportional to the light intensity and the storage time for storing the light. Therefore, by changing the accumulation time for accumulating light, the level of the electrical signal obtained by the solid-state imaging device 1aa also changes. That is, when the accumulation time for accumulating light is shortened, the level of the electrical signal from the solid-state imaging device 1aa is reduced. For this reason, when the accumulation time is varied, the level of the output signal from the solid-state imaging device 1aa can be made constant by setting the brightness of the illumination lamp 20a to be inversely proportional to the image accumulation time.
[0041]
The CCD camera 25a of the image pickup device 25 as the image pickup means has a storage function for starting storage of an image by an external control signal such as the image recognition device 8 and a charge storage as an electric signal of the photosensitive storage unit 1ab. It has an accumulation time control function to variably control the time to do.
[0042]
The lighting device 20 as a lighting means for illuminating the bonding component includes an illuminating lamp 20a composed of one or more light emitting diodes (LEDs), and an illumination control device 20b that controls current supply to the light emitting diodes such as blocking and the like. It consists of and.
[0043]
The lighting device 20 can be turned on / off and the brightness of the illumination can be variably controlled by a signal from the image recognition device 8. In other words, the illumination control device 8b of the illumination device 20 is configured to receive a brightness data of the illumination lamp 20a from the outside and to flow a predetermined current to the light emitting diode.
[0044]
As shown in FIG. 2, the image recognition device 8 includes a clock signal generation circuit 8a and a camera control signal that outputs a control signal to the CCD camera 25a in accordance with a clock from the clock signal generation circuit 8a and a signal from the control circuit 8f. A generation circuit 8b, an amplifier 8c for amplifying a video signal output from the CCD camera 25a, a converter 8e for converting the signal output from the amplifier 8c into a multivalued or binarized digital value, and the conversion An image processing circuit 8d for performing image recognition such as pattern matching between a digital value of the video signal output from the image generator 8e and reference pattern data, an image memory 8g for storing a reference pattern for detecting misregistration, and the image processing A control circuit 8f incorporating a microcomputer for controlling the circuit 8d, the camera control signal generation circuit 8b, the illumination control circuit, and the like; And output circuit h that communicates with the control device 10, consisting of illumination control signal generation circuit 8j for controlling the lighting control device 20b.
[0045]
In the following, in the position detection operation of the lead locator for detecting the position of the IC chip 12 as a part to be bonded in the bonding apparatus according to the present invention, the position detection of the lead 15 and the individual position of the lead 15. The control when the camera image is taken into the image recognition apparatus 8 will be described.
[0046]
In addition, when performing wire bonding in the bonding apparatus according to the present invention, it is assumed that self-teach for performing various condition settings and the like is performed in advance. That is, the pad 12a of the IC chip 12 as the first bonding point, the lead 15 as the second bonding point, the reference point on the IC chip 12, information on the coordinate position of the reference point of the lead 15, etc., and the reference pattern This is a condition setting such as image information. Accordingly, position information for bonding and the like is stored in a memory (not shown) in the control device 10 shown in FIG. 1, and image information and the like are stored in an image memory 8g of the image recognition device 8, respectively.
[0047]
FIG. 5 is a diagram illustrating a timing chart of the operation of capturing the camera image into the image recognition device 8 in the position detection operation.
[0048]
As shown in FIG. 5A, the XY table 4 on which the imaging device 25 and the illumination lamp 20a are mounted starts to move from time T1 and stops at the target position at time T2. As shown in FIG. 5B, the driving device 11 outputs a coincidence signal to notify the control device 10 that the XY table 4 is at a predetermined position (target position). The control device 10 issues a command to the image recognition device 8 to take in the video signal from the imaging device 25 as the imaging means.
[0049]
The image recognition apparatus 8 outputs an image accumulation start signal and an image accumulation time control signal (St in FIG. 5) shown in (c) of FIG. 5 to the imaging apparatus 25 as an imaging unit.
[0050]
The imaging device 25 receives the image accumulation start signal output from the image recognition device 8 and starts image accumulation at the same time (time T2 in FIG. 5D), and the image output from the image recognition device 8 The image is accumulated for a predetermined time based on the accumulation time (time T3 in FIG. 5D). After the image capturing device 25 completes image storage, the image capturing device 25 outputs a video signal to the image recognizing device 8 ((f) in FIG. 5).
[0051]
In addition, the image recognition device 8 outputs an image accumulation start signal and an image accumulation time to the imaging device 25, and at the same time outputs a lighting start and brightness control signal indicated by Lt in FIG. To 20b. The illumination control device 20b controls the illumination lamp 20a so that the illumination lamp 20a is turned on and illuminated at a predetermined brightness during the image accumulation period of the imaging means.
[0052]
The control device 10 issues a command to the drive device 11 to move to the next moving point after the image accumulation period of the imaging device 25 ends (time T3 in FIG. 5) with respect to the XY table 4. After stopping at time T5 shown in FIG. 5, the above-described operation is repeated, and the camera image capturing operation to the image recognition device 8 is repeated.
[0053]
Next, FIG. 6 shows a timing chart for capturing a camera image while the XY table 4 is moving.
[0054]
The XY table 4 equipped with the imaging device 25 and the illumination lamp 20a starts to move at time T10 ((a) in FIG. 6), and accelerates and decelerates based on the speed drive waveform V shown in (b) in FIG. It moves at a lower speed than time T11 in FIG. When the XY table 4 reaches a predetermined position, the coincidence detection circuit 11c of the drive device 11 outputs a coincidence signal to the control device 10 (time T12 in FIG. 6C).
[0055]
The control device 10 issues a command to the image recognition device 8 to take in the video signal from the imaging device 25 as the imaging means. The image recognition device 8 outputs an image accumulation start signal and an image accumulation time control signal (St in FIG. 6) shown in FIG.
[0056]
The imaging device 25 receives the image accumulation start signal output from the image recognition device 8 and simultaneously starts image accumulation (time T12 in FIG. 5E), and the image output from the image recognition device 8 The image is accumulated for a predetermined time based on the accumulation time (time T13 in FIG. 6E). After the image capturing device 25 completes image storage, the image capturing device 25 outputs a video signal to the image recognition device 8 ((g) in FIG. 6).
[0057]
In addition, the image recognition device 8 outputs an image accumulation start signal and an image accumulation time to the imaging device 25, and at the same time outputs a lighting start and brightness control signal indicated by Lt in FIG. Output to. The illumination control device 20b controls the illumination lamp 20a so that the illumination lamp 20a is turned on and illuminated at a predetermined brightness during the image accumulation period of the imaging device 25. That is, as is clear from the illumination control signal Lt shown in FIG. 5 (e), the illumination control signal Lt shown in FIG. 6 (f) has a high brightness level because the image accumulation time is short. Yes.
[0058]
Next, when the coincidence signal shown in FIG. 6C is input while the XY table 4 is moving, the control device 10 repeats the above-described operation from time T15 shown in FIG. The camera image capturing operation to the apparatus 8 is repeated.
[0059]
The camera image capturing operation during movement of the XY table 4 shortens the image accumulation time, reduces the movement time of the XY table 4 at a low speed, and illuminates brightness data that is inversely proportional to the image accumulation time. By giving it to the control device 20b, an image having a constant brightness can be obtained from the imaging device 25 in a short time.
[0060]
The operation of the bonding apparatus according to the present invention will be described below. Note that the camera image capture in the following description is performed when the XY table 4 is stopped.
[0061]
As shown in FIG. 1, when the lead frame L / F is transferred onto the bonding stage 7 by the transfer device 5 from a magazine (not shown) in which the lead frame L / F is stored, the control device 10 The driving device 11 is driven based on the reference point information stored in advance in the memory, and the image pickup device 25 mounted on the XY table 4 is moved to the coordinates of the first reference point on the IC chip 12. At this time, the imaging device 25 is located at the coordinates of the first reference point.
[0062]
After confirming the completion of movement of the XY table 4, the control device 10 issues a command to the image recognition device 8 to take in the video signal from the imaging device 25 as the imaging means. The image recognition device 8 outputs an image accumulation start signal and an image accumulation time control signal to the imaging device 25 as an imaging means. At the same time, the image recognition device 8 outputs an illumination control signal to the illumination control device 20b.
[0063]
The imaging device 25 receives the image accumulation start signal output from the image recognition device 8 and starts image accumulation at the same time, and performs image accumulation based on the image accumulation time output from the image recognition device 8. Do the time.
[0064]
After the image capture device 25 completes image accumulation, the control device 10 drives the drive device 11 based on the reference point information stored in the memory in the control device 10 to connect the image capture device 25 mounted on the XY table 4 to the IC. Move to the position of the second reference point on the chip 12.
[0065]
While the XY table 4 is moving, the video signal of the imaging device 25 is input to the amplifier 8 c of the image recognition device 8.
[0066]
The control device 10 outputs a control signal for detecting detection of the shift amount to the control circuit 8f of the image recognition device 8.
[0067]
The control circuit 8f of the image recognition device 8 reads the image information stored as the reference pattern of the first reference point from the memory 8e, transfers it to the image processing circuit 8d, and outputs a control signal for position detection processing to the image processing circuit 8d. To do. The video signal of the imaging device 25 amplified by the amplifier 8c is converted into a digital signal by the converter 8e and input to the image processing circuit 8d. The image processing circuit 8d performs matching between the signal digitized by the converter 8e and the reference pattern transferred from the memory 8e, and detects a deviation amount. The detected deviation amount is output from the control circuit 8f to the control device 10.
[0068]
After confirming the completion of the movement of the XY table 4 to the second reference point, the control device 10 issues a command to the image recognition device 8 to capture the video signal from the imaging device 25 as the imaging means.
[0069]
The image recognition device 8 outputs an image accumulation start signal for the part to be bonded and a control signal for the image accumulation time to the imaging device 25 as an imaging means. Further, the image recognition device 8 outputs an illumination control signal to the illumination control device 20b.
[0070]
After the image storage device 25 completes image accumulation, the control device 10 drives the drive device 11 based on the reference point information stored in the memory of the control device 10 to lead the image pickup device 25 mounted on the XY table 4 to the lead frame. Move to the position of the third reference point on L / F.
[0071]
While the XY table 4 is moving, the video signal of the imaging device 25 is input to the amplifier 8 c of the image recognition device 8.
[0072]
The control device 10 outputs a control signal for detecting displacement detection to the control circuit 8 f of the image recognition device 8.
[0073]
The control circuit 8f of the image recognition device 8 reads the image information stored as the reference pattern of the second reference point from the memory 8e, transfers it to the image processing circuit 8d, and outputs a control signal for position detection processing to the image processing circuit 8d. To do. The imaging signal of the imaging device 25 amplified by the amplifier 8c is converted into a digital signal by the converter 8e and input to the image processing circuit 8d. The image processing circuit 8d performs matching between the signal digitized by the converter 8e and the reference pattern transferred from the memory 8e, and detects a deviation amount. The detected deviation amount is output from the control circuit 8f to the control device 10.
[0074]
The control device 10 calculates the bonding coordinates stored in the memory based on the deviation amount data from each reference point, and obtains the position of each pad 12a to be bonded.
[0075]
After confirming the completion of the movement of the XY table 4 to the third reference point, the control device 10 issues a command to the image recognition device 8 to take in the video signal from the imaging device 25 as the imaging means. The image recognition device 8 outputs an image accumulation start signal for the part to be bonded and a control signal for the image accumulation time to the imaging device 25 as an imaging means. Further, the image recognition device 8 outputs an illumination control signal to the illumination control device 20b.
[0076]
The control device 10 outputs a control signal for detecting a shift amount to the control circuit 8f of the image recognition device 8.
[0077]
The control circuit 8f of the image recognition device 8 reads the image information stored as the reference pattern of the third reference point from the memory 8e, transfers it to the image processing circuit 8d, and outputs a control signal for position detection processing to the image processing circuit 8d. To do. The video signal of the imaging device 25 amplified by the amplifier 8c is converted into a digital signal by the converter 8e and input to the image processing circuit 8d. The image processing circuit 8d performs matching between the signal digitized by the converter 8e and the reference pattern transferred from the memory 8e, and detects a deviation amount. The detected deviation amount is output from the control circuit 8f to the control device 10.
[0078]
The control device 10 calculates the position coordinates of the lead 15 stored in the memory based on the deviation amount data from the third reference point to obtain the position of each lead 15.
[0079]
Next, detection of the bonding position of each lead 15 by the lead locator will be described. The control device 10 drives the driving device 11 based on the obtained position coordinates of each lead 15, and moves the imaging device 25 mounted on the XY table 4 so that the plurality of leads 15 are located in the imaging area. .
[0080]
After confirming the completion of the movement of the lead 15 of the XY table 4 to the detection position, the control device 10 issues a command to the image recognition device 8 to take in the video signal from the imaging device 25 as imaging means. The image recognition device 8 outputs an image accumulation start signal for the part to be bonded and a control signal for the image accumulation time to the imaging device 25 as an imaging means. Further, the image recognition device 8 outputs an illumination control signal to the illumination control device 20b.
[0081]
After the imaging device 25 completes image accumulation, the control device 10 moves the XY table 4 to the next lead detection position based on the position information of the lead 15 stored in the memory of the control device 10.
[0082]
The control device 10 outputs a control signal for detecting the lead position to the control circuit 8 f of the image recognition device 8. The image processing circuit 8 d of the image recognition device 8 detects the positions of the bonding points of the plurality of leads 15 based on the image signal from the imaging device 25. The detected position of each lead 15 is output to the control device 10 from the control circuit 8f.
[0083]
In the subsequent read locate operation, the above-described operation is repeated a predetermined number of times to detect the position of the lead 15.
[0084]
The position of the lead 15 detected by the lead locator is wire-bonded using the position of the pad 12a calculated from the amount of displacement of the IC chip 12 as the second bonding point and the position of the pad 12a as the first bonding point.
[0085]
The image capturing of the image pickup apparatus 25 according to the present invention is not limited to the above-described IC chip shift amount detection and lead locator, but a bonding apparatus with a bonding inspection function for inspecting the bonding state after bonding based on the image of the image pickup apparatus 25. Can also be applied.
[0086]
【The invention's effect】
As described above, according to the wire bonding apparatus according to the present invention, when the XY table reaches a predetermined position, the accumulation of the image of the camera is started, and the accumulation time is made variable to accumulate the image in a short time. As a result of this, the image capture time is shortened, the operation time of the reed locator can be shortened, and the number of bonding parts produced can be increased.
[0087]
Further, it is possible to capture an image while the XY table is moving, and it is possible to further shorten the time for capturing the image. A more stable image can be obtained even when the image is captured while the XY table is moving.
[Brief description of the drawings]
FIG. 1 is a schematic view showing a configuration of a wire bonding apparatus according to the present invention.
FIG. 2 is a block diagram illustrating a circuit configuration of the image recognition apparatus.
FIG. 3 is a diagram illustrating a circuit configuration of a solid-state image sensor.
FIG. 4 is a block diagram of a signal converter, a counter circuit, and a coincidence detection circuit in the driving device.
FIG. 5 is a timing diagram illustrating capturing of an image from the imaging apparatus when the XY table is stopped.
FIG. 6 is a timing diagram illustrating capturing of an image from the imaging apparatus when the XY table is moved.
FIG. 7 is a schematic view showing a configuration of a conventional wire bonding apparatus.
FIG. 8 is a timing diagram showing image capture from a conventional camera.
FIG. 9 is a diagram showing an IC chip position and a lead position on a lead frame;
[Explanation of symbols]
L / F Lead frame
1 Camera
1a Camera head
1c Optical lens (lens)
2 Bonding arm
2a Capillary
3 Bonding head
4 XY table
5 Transport device
7 Bonding stage
7a Heater 7
8 Image recognition device
8a Clock signal generation circuit
8b Camera control signal generation circuit
8c amplifier
8d image processing circuit
8e converter 8e
8f Control circuit 8f
8g image memory
8h I / O circuit
8j Lighting control signal generation circuit
9 Monitor
9a Cross line
9b wind
10 Control device
11 Drive device
12 IC chip
12a Pad 1
14 Land
15 lead
20 Lighting device
20a Lighting lamp
20b Lighting control device
25 Imaging device
25a CCD camera
30 Image processing device

Claims (3)

A bonding means for bonding to a part to be bonded;
Positioning means for positioning relative to the bonding means and the part to be bonded in a two-dimensional manner;
Imaging means for imaging the part to be bonded mounted on the positioning means;
Image recognition means for processing a signal from the imaging means to recognize an image;
In a bonding apparatus having a control means for controlling the bonding apparatus,
When the positioning means reaches a predetermined position during movement, the image recognition means outputs an image accumulation start signal of the part to be bonded and a control signal of an image accumulation time to the imaging means,
The imaging means receives the image accumulation start signal output from the image recognition means, and simultaneously starts image accumulation, and performs image accumulation for a predetermined time based on the image accumulation time output from the image recognition means. A bonding apparatus comprising image output means for outputting a video signal to the image recognition means after completion of image storage. A bonding means for bonding to a part to be bonded;
Positioning means for positioning relative to the bonding means and the part to be bonded in a two-dimensional manner;
Imaging means for imaging the part to be bonded mounted on the positioning means;
Image recognition means for processing a signal from the imaging means to recognize an image;
In a bonding apparatus having a control means for controlling the bonding apparatus,
The image recognition means, after the positioning means stops at a predetermined position, outputs an image accumulation start signal and an image accumulation time control signal to the image pickup means,
The imaging means receives the image accumulation start signal output from the image recognition means, and simultaneously starts image accumulation, and performs image accumulation for a predetermined time based on the image accumulation time output from the image recognition means. Then, after the image accumulation is completed, a video signal is output from the image output means to the image recognition means,
The bonding apparatus according to claim 1, wherein the positioning unit starts moving after the imaging unit completes image accumulation. The image recognition means outputs an image accumulation start signal and an image accumulation time to the image pickup means, and simultaneously outputs a signal for controlling lighting start and lighting brightness to an illumination means for illuminating the part to be bonded. 3. The bonding apparatus according to claim 1, wherein the illuminating unit illuminates and illuminates at a predetermined brightness during an image accumulation period of the imaging unit.

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