JPH1084005A - Die-bonding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate the setting operation of a lifti-up pin before die-bonding in a die-bonding device. SOLUTION: A contact sensor, which detects the state wherein a tool 18 comes in contact with a chip 50, is provided. After the tool 18 has been brought down to an attracting position (a), the chip 50 is lifted up by raising the contact sernsor (b). The movement of the lift-up pin 9 is controlled from the moving position of the lift-up pin 9 at the point of time when the chip 50 comes in contact with the tool 18 is detected by the contact sensor. Accordingly, the setting operation of the reference movement position of the lift-up pin 9 and the movement position of the lift-up pin 9 when an attraction operation is conducted, are unnecessitated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a die bonding apparatus.

[0002]

2. Description of the Related Art Conventionally, in a die bonding apparatus which is arranged on a semiconductor device manufacturing line and bonds a chip to an object such as a lead frame, a substrate or a package, a wafer attached to a sheet is cut into a plurality of pieces. Is provided. The die bonding apparatus generally slides up and down on the back side of a sheet and pushes up on individual chips through the sheet and pushes up individual chips through the sheet, and on the tip of a bonding arm that moves in the X, Y, and Z directions. A tool that is freely held and sucks the chip pushed up by the push-up pin. Then, after the chip that has been sucked by the tool is transferred to the object by the operation of the bonding arm, bonding is performed. It should be noted that a predetermined urging force is applied to the tool when moving relative to the bonding arm upward.

[0003] On the other hand, the operating position of the push-up pin is set in accordance with the suction position of the tool prior to die bonding. In this setting operation, the operator manually operates the bonding arm and adjusts the respective positions with a scope. The adjustment is performed using a tool or a jig. The setting operation is also performed when the push-up pin is replaced due to wear or the like, or when the type of chip to be handled is changed.

[0004]

However, in the above-mentioned setting operation for the push-up pin, since the reference position of the operation is different for each different tool and fine adjustment is required, the operation is checked many times. Has to be performed while repeating, and it takes a lot of time.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and has as its object to provide a die bonding apparatus which facilitates a setting operation for a push-up pin prior to die bonding.

[0006]

In order to solve the above problems, according to the first aspect of the present invention, a bonding arm,
A tool provided on the bonding arm, and a push-up pin that operates vertically below the supplied chip and pushes up the chip, and moves the chip pushed up by the push-up pin with the operation of the bonding arm. In a die bonding apparatus in which a tool is sucked and bonded to an object, a detecting means for detecting that the tool abuts on the chip is provided in a sucking operation in which the tool sucks the chip, and the detecting means comprises: A pin operating position obtaining means for obtaining an operating position of the push-up pin in a push-up direction at a point in time when it is detected that the tool has contacted the chip, and the push-up operation is performed based on the operating position obtained by the pin operating position obtaining means. And a pin control means for controlling the operation of the pin.

In this configuration, the pin control means needs to set the vertical operation position of the push-up pin in advance in order to control the operation of the push-up pin based on the operation position acquired by the pin operation position acquisition means. Disappears.

Further, in the invention according to claim 2, a reference operation position setting for setting a reference operation position as a reference of an up-down operation position of the push-up pin based on the operation position acquired by the pin operation position acquisition means. Means, reference operation position storage means for storing the reference operation position set by the reference operation position setting means, the pin control means,
The operation of the push-up pin is controlled based on the reference operation position stored in the reference operation position storage means.

In this configuration, the pin control means, after being set by the reference operation position setting means, controls the operation of the push-up pin based on the operation position stored in the pin operation position storage means, so that the suction operation is performed once. If this is done, the setting operation for the push-up pins performed prior to the die bonding can be automatically performed.

According to the third aspect of the present invention, the push-up operation position storage means for storing the operation position acquired by the pin operation position acquisition means, the operation position previously stored in the push-up operation position storage means, and And a suction operation inspecting means for inspecting the suction operation based on the operation position obtained by the pin operation position obtaining means at the time of the suction operation.

In such a configuration, for example, if a foreign object exists between the tool and the sucked chip during the suction operation, or if the tip of the tip push-up pin is damaged, the pin operation position obtaining means obtains the tip when the suction operation is performed. A difference occurs between the operation position and the operation position stored in advance in the push-up operation position storage means, and the difference is inspected by the suction operation inspection means. Therefore, it is possible to know the occurrence of a defect during the suction operation from the inspection result by the suction operation inspection means while performing the die bonding.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a die bonding apparatus according to the present invention. The die bonding apparatus includes a transfer rail 1 for transferring a lead frame, a wafer supply unit A, and a bonding unit B. An XY table 2 is provided in the wafer supply unit A. On the XY table 2, a wafer holding mechanism unit 5 that holds a sheet 3 to which a wafer divided into a plurality of chips is attached by using a wafer ring 4 is provided via a support 6. A push-up mechanism 7 is provided below the wafer holding mechanism 5. Thrust mechanism 7
Has a push-up head 8 and push-up pins 9 for pushing up a chip 50 supplied by moving up and down inside the sheet 3 from the back side of the sheet 3 (see FIG. 5).

On the other hand, the bonding section B is provided with a bonding head drive section 12 driven by an X-axis motor (not shown), a Y-axis motor 10 and a Z-axis motor 11. The bonding head drive unit 12 is provided with a bonding arm 13 extending upwardly of the transport rail 1 and operating in a vertical direction. The bonding head, which is the tip of the bonding arm 13, is provided with a mounting portion 14 as shown in FIG. A collet holder 15 is supported by the mounting portion 14 so as to be slidable in the vertical direction and rotatable. A collet 16 for sucking the chip pushed up by the push-up pin 9 is fitted in the collet holder 15. Further, a permanent magnet 17 whose upper part is formed into a spherical shape is exposed and attached to the upper part of the collet holder 15. The collet holder 15 and the collet 1
6 constitutes a tool 18.

The bonding head supports a load transmission arm 19 formed in a substantially U-shape so as to be able to turn up and down around a fulcrum O located at the bent portion. At one end of the load transmitting arm 19, a suspending member 20 extending directly above the collet holder 15 is provided.
Is provided. A permanent magnet is provided inside the suspension member 20 (not shown), and the tool 18 is rotatably suspended by the magnetic force of the permanent magnet and the permanent magnet 17 on the collet holder 15 side. On the other end side of the load transfer arm 19, a load mechanism C is formed. That is, between the other end of the load transmitting arm 19 and the adjusting screw 21 supported on the bonding arm 13 side, a coil spring 22 that urges the other end upward in the drawing is stretched. The bonding arm 13 is provided with a stopper 23 for determining an upward rotation limit position on the other end side of the load transmitting arm 19, whereby a tool magnetically attached to and suspended from one end of the load transmitting arm 19 is provided. 18 is stopped at a certain position, and a downward load is applied when trying to move upward from that position.

On the lower surface on the other end side of the load transmitting arm 19,
A mover 26 that constitutes a linear motor 25 together with a stator 24 provided on the bonding arm 13 is provided. The linear motor 25 supplies the electric power (voltage or current) to the stator 24 to move the movable element 26 close to or away from the movable element 26. The linear motor 25 increases or decreases the spring force of the coil spring 22 by changing the supplied electric power. The above-described downward load transmitted to the tool 18 via the load transmission arm 19 is changed. In addition, a landing sensor 27 serving as a detecting means of the present invention is provided on the bonding arm 13 side in the vicinity of the coil spring 22. The landing sensor 27 detects when the load transmitting arm 19 is slightly turned to the right in the figure, and thereby detects the load transmitting arm 1.
It detects that the tool 18 magnetically attached to one end side of 9 moves upward relative to the bonding arm 13. That is, it detects that the tool 18 has contacted the chip.

Further, the die bonding apparatus is provided with a controller 31 shown in FIG. 3, which is control means of the present invention. The controller 31 includes a pin lifting motor 32 for raising and lowering the push-up pins 9 provided in the push-up mechanism 7 of the wafer supply unit A, an X-axis motor 33, a Y-axis motor 10 for the bonding unit B,
A Z-axis motor 11, a head actuator 34 for driving the bonding head drive unit 12, a landing sensor 27, and a mode switch 35 for setting various operation modes are connected. The mode switch 35 is specifically composed of a plurality of operation switches assigned for each operation mode. Inside the controller 31, although not shown, a ROM in which a control program of the die bonding apparatus is stored in advance and a RAM in which various data necessary for executing the control program are stored and updated as necessary are provided. The controller 31 controls the operation of the die bonding apparatus based on the control program. The control of the drive system such as the X-axis motor 33 by the controller 31 is performed based on the number of pulses obtained by counting the pulses sent from each. The bonding arm 13 is driven by the Z-axis motor 11 in the vertical direction.

Next, the operation of the die bonding apparatus having the above configuration will be described with reference to a flowchart showing the processing contents of the controller 31 according to the present invention. FIG.
Shows a tool height setting process prior to the actual die bonding operation. The controller 31 starts operating when an operation switch for setting operation is operated, operates the bonding arm 13, and moves the tool 18 at the home position to just above the positioned chip 50 (SA1). Next, the tool 18 is lowered at a high speed (SA2). In such a case, the Z-axis motor 1
1 and the number of pulses P indicating the amount by which the tool 18 has descended from the home position is sequentially acquired. When the number of pulses P reaches the preset number of pulses N1, (S
(YES in A3) The descending speed is changed to a low speed (SA4).
When the movement of the tool 18 relative to the bonding arm 13 is detected after the tool 18 comes into contact with the chip 50 (YES in SA5), the tool 18 is stopped at that time (SA6). Next, a value obtained by subtracting a preset pulse number x indicating the amount of upward movement of the tool 18 in the dead zone of the landing sensor 27 and a pulse number Z1 indicating the offset amount from the pulse number P at that time. That is, the pulse number P1 indicating the suction position of the tool 18
Is stored (SA7). Subsequently, after the chip 50 is attracted to the tool 18 and the tool 18 is lifted and moved to just above the bonding point in the lead frame on the transport rail 1 (SA8), the step SA
Go to 9. The operation of the tool 18 associated with the above processing is shown in FIGS.

Then, the tool 18 is lowered at a high speed,
The pulse number P is sequentially obtained, and when the pulse number P reaches the preset pulse number N2 (YES in SA10), the descending speed is changed to a low speed (SA11). Eventually chip 50
After the tool abuts on the lead frame, the tool 18 moves relatively upward with respect to the bonding arm 13, and when this is detected (YES in SA12), the tool 18 is stopped at that time (SA13). Next, a value obtained by subtracting the above-mentioned pulse number x from the pulse number P at that time, that is, the pulse number P2 indicating the bonding position of the tool 18 is stored (SA14). Thereafter, the tool 18 is moved to the home position (SA15), and the process ends.
Thus, the vertical operation position of the tool 18 during the suction operation or the bonding operation is automatically set. Therefore, the setting operation prior to the die bonding can be performed extremely easily.

FIG. 6 shows a process of setting the height of the push-up pins prior to the actual die bonding.
The controller 31 starts operation by operating an operation switch for setting operation, and proceeds to step SA in FIG.
The same processing as in 1 to SA4 is performed (SB1 to SB4). Eventually, when the pulse number P reaches the pulse number P1 indicating the suction position stored in step SA7 in FIG. 4 (YE in SB5).
S), that is, when the tool 18 reaches the set suction position, the tool 18 is stopped at that time (SB6). Next, the pin lifting motor 32 is driven to raise the push-up pin 9 (SB7). Eventually, when the push-up pin 9 comes into contact with the chip 50 and the tool 18 moves upward relative to the bonding arm 13 and the landing sensor 27 detects it (YES in SB8), the push-up pin 9 is released. Stop (SB9).

Next, the pin elevating motor 3 at that time is
From the number of pulses Q sent from 2, the number of pulses x
And a value obtained by subtracting the pulse number M indicating the push-up operation amount set in advance, that is, the pulse number Q0 indicating the reference operation position of the push-up pin 9 is stored (SB10). Subsequently, the push-up pin 9 is lowered (SB11), and when the pulse number Q reaches the pulse number Q0 (YE in SB12).
S), that is, when it reaches the operation reference position, the push-up pin 9 is stopped at that time (SB13). Then, after moving the tool 18 to the home position (SB1
4), the setting process ends. The operations of the push-up pin 9 and the tool 18 associated with the above-described processing are shown in FIGS.
(D). Thereby, the tip 5 of the push-up pin 9
The operation position and the operation reference position at the time of the suction operation of 0 are automatically set. Therefore, the setting operation regarding the push-up pins 9 performed prior to the die bonding can be easily performed. The setting operation is also performed when the push-up pin 9 is replaced due to wear or the like, or when the type of the tip 50 is changed.

FIG. 8 is a flowchart showing the processing contents of the controller 31 in die bonding.
That is, the controller 31 starts the operation by operating the operation switch for starting the operation, moves the tool 18 to the suction position and stops it in the same procedure as steps SB1 to SB6 in FIG. ), The push-up pin 9 is raised (SC2). Eventually, the landing sensor 27
The bonding arm 13 in the tool 18
When an upward movement relative to is detected (SC3
YES), the number of pulses Q and the number of pulses (Q0 +
x + M) is determined to be within a range of ± K (a preset value) (SC4). That is, the operating position of the push-up pin 9 at that time and the step SB1 in FIG.
It is determined whether or not the difference from the operating position at the time of setting, which is indirectly stored based on the number of pulses Q0 acquired at 0, is within a predetermined allowable range. Here, if the result of this determination is YES, step SC
Go to 5.

On the other hand, if the decision result in the step SC3 is NO, for example, there is a foreign substance between the tool 18 and the sucked chip 50, or the tip of the push-up pin 9 is damaged as shown in FIG. If not, the process proceeds to step SC18 to notify the occurrence of a trouble,
After stopping all the operations (SC19), the process is temporarily terminated. After that, it is in a standby state for an operation command. Thus, it is possible to notify the occurrence of a problem during the suction operation of the chip 50 while performing the die bonding. As a result, it is possible to improve the yield by immediately discovering a defect at the time of the suction operation, which causes a bonding failure.

In step SC5, step SC5
The number of pulses Q at the time of YES at 3 is the number of pulses (Q0
+ X + M + M1). M1 is
This is a preset number of pulses indicating the excess push-up amount. After the pushed-up tip 50 comes into contact with the tool 18, the tip 50 is further pushed up and the tool 18 moves upward by a predetermined amount. If the result is YES, the push-up pin 9 is stopped (SC6). Thereafter, the chip 50 is sucked to the tool 18, the tool 18 is moved to a position immediately above the bonding point (SC
7) The push-up pin 9 is moved to the reference operation position indicated by the preset pulse number Q0 (SC8). Thus, the suction operation of the chip 50 ends. As described above, after the tip 50 contacts the tool 18, the tip 50 is further pushed up by a predetermined amount by the push-up pin 9, so that the tool 1 at the time of sucking the tip 50 is moved.
8 is prevented from being displaced.

Next, the tool that has just moved to the position just above the bonding point is lowered at high speed (SC9), and the Z-axis motor 11
When the number of pulses P sent from the above becomes the above-mentioned number of pulses N2 (YES in SC10), the descending speed is changed to a low speed (SC11). Eventually, after the chip 50 comes into contact with the lead frame, the tool 18 moves upward with respect to the bonding arm 13 and when it is detected (SC1
2; YES), whether the difference between the value obtained by subtracting the pulse number x from the pulse number P at that time and the pulse number P2 stored in advance is within a range of ± K (a preset value). Is determined (SC13). That is, it is determined whether or not the difference between the operating position of the push-up pin 9 at that time and the operating position at the time of setting stored in advance is within a predetermined allowable range.

If the result of this determination is NO, for example, as shown in FIG. 10A, the distance between the tool 18 and the sucked chip 50 (or between the chip 50 and the lead frame 55)
In the case where the foreign matter 100 is present between the steps (a) and (b), or the tip of the tool 18 is damaged as shown in FIG. 10 (b), the processing in steps SC18 and SC19 described above is performed. Is temporarily terminated, and a standby state for an operation command is set. Thus, it is possible to notify the occurrence of a defect during the bonding operation while performing the die bonding. As a result, it is possible to improve the yield by immediately finding a defect at the time of the bonding operation, which causes the bonding defect.

On the other hand, if the result of the determination in step SC13 is Y
If it is ES, it is further determined whether or not the pulse number P at the time of YES in step SC12 has become the pulse number (P2 + Z2) (SC14). Z2 is a preset number of pulses indicating the amount of sinking of the tool 18, and when the bonding arm 13 moves further downward after the chip 50 lands and a predetermined bonding load is applied to the chip 50, The result of the determination is YES, at which point the tool 18 is stopped (SC15). Subsequent step S
At C16, the tool 18 performs a scrub operation to bond the chip 50 to the lead frame 55. Thereafter, the tool 18 is moved to the home position (SC1).
7), the process ends.

Note that steps SC4 and SC14 described above are performed.
In the controller 31, the difference between the number of pulses indicating the operating position of the push-up pin 9 during the suction operation or the operating position of the tool 18 during the bonding operation and the number of pulses indicating the operating position stored in advance is determined in advance. Although the determination is merely made as to whether or not the value is within a predetermined allowable range, the present invention is not limited to this, and the height of the operation position at the time of inspection with respect to the operation position stored in advance may be inspected. Further, based on the inspection result, the type of the trouble that has occurred during the suction operation or the bonding operation may be determined and reported.

On the other hand, in the present embodiment, when setting and controlling the operating positions of the push-up pin 9 and the tool 18 (bonding arm), the preset number of pulses x is subtracted or added, whereby the landing sensor 27 is set. Although the operation position is corrected in consideration of the amount of upward movement of the tool 18 in the dead zone of FIG.
In the case of using a filter having no dead zone, the correction is unnecessary. Further, in the present embodiment, the landing sensor 27 detects the upward movement of the tool 18 relative to the bonding arm 13 by using the load transmitting arm 19.
That is, since the detection is performed indirectly via another member, the tool 18 is not used during the suction operation of the chip 50 or the bonding operation.
The movement of the tool 18 can be detected without being affected by chattering occurring in the tool 18. Therefore, it is possible to more accurately know the point in time when the tool 18 has moved upward relative to the bonding arm 13. As a result, the push-up pin 9 and the tool 18 (bonding arm 1)
The operation position of 3) can be controlled more accurately.

In this embodiment, the push-up pins 9 and 9 are set by a setting operation prior to die bonding.
And the operation position of the tool 18, that is, the operation position of the bonding arm 13 is previously set and stored in the controller 31. However, the present invention is not limited thereto. The operating position of the push-up pin 9 and the tool 18 (bonding arm 13) at the time of die bonding may be controlled based on the operating position at the time of detecting the upward movement.
In that case, it is not necessary to set those operation positions in advance.

[0030]

As described above, according to the first aspect of the present invention, the operation of the push-up pin is controlled by the pin control means based on the operation position acquired by the pin operation position acquisition means, and the vertical movement of the push-up pin is controlled. It is no longer necessary to set the operating position in advance. Therefore, setting work prior to die bonding becomes extremely easy.

According to the second aspect of the present invention, if the pin control means controls the operation of the push-up pin based on the reference operation position stored in the pin operation position storage means and performs the suction operation only once, The setting work on the push-up pins performed prior to the bonding can be automatically performed. Therefore, setting work prior to die bonding becomes extremely easy.

Further, according to the third aspect of the present invention, it is possible to know the occurrence of a defect during the suction operation from the inspection result by the suction operation inspection means while performing the die bonding. Therefore, it is possible to immediately find a defect at the time of the suction operation, which causes a bonding failure, and as a result, it is possible to improve the yield.

[0033]

[Brief description of the drawings]

FIG. 1 is a side view of a die bonding apparatus according to an embodiment of the present invention.

FIG. 2 is an enlarged view of a main part of FIG. 1 showing a bonding head.

FIG. 3 is a block diagram illustrating a die bonding apparatus.

FIG. 4 is a flowchart showing a tool height setting process prior to die bonding.

FIG. 5 is an explanatory diagram illustrating an operation of a tool accompanying a tool height setting process.

FIG. 6 is a flowchart showing push-up pin push-up height setting processing prior to die bonding.

FIG. 7 is an explanatory diagram showing operations of a tool and a push-up pin in a push-up pin push-up height setting process.

FIG. 8 is a flowchart showing processing contents at the time of die bonding.

FIG. 9 is a state diagram illustrating an example of a problem that occurs during a chip suction operation.

FIG. 10 is a state diagram showing an example of a defect that occurs during a bonding operation.

[Explanation of symbols]

 9 push-up pin 11 Z-axis motor 13 bonding arm 18 tool 27 landing sensor (detection means) 31 controller

Claims (3)

[Claims] 1. A bonding arm, a tool provided on the bonding arm, and a push-up pin that operates in a vertical direction below a supplied chip and pushes up the chip.
In a die bonding apparatus in which the tool pushed up by the push-up pin is sucked by the tool and bonded to an object, the tool performs a suction operation of sucking the chip.
Detecting means for detecting that the tool has contacted the chip; and a pin for acquiring an operating position of the push-up pin in the pushing direction at the time when the detecting means detects that the tool has contacted the chip. A die bonding apparatus comprising: an operating position obtaining unit; and a pin control unit that controls the operation of the push-up pin based on the operating position obtained by the pin operating position obtaining unit. 2. A reference operation position setting means for setting a reference operation position serving as a reference of a vertical operation position of the push-up pin, based on the operation position acquired by the pin operation position acquisition means; Reference operation position storage means for storing the reference operation position set by the setting means, wherein the pin control means controls the operation of the push-up pin based on the reference operation position stored in the reference operation position storage means. The die bonding apparatus according to claim 1, wherein: 3. A push-up operation position storage means for storing an operation position acquired by said pin operation position acquisition means, an operation position previously stored in said push-up operation position storage means, and said pin operation during said suction operation. The die bonding apparatus according to claim 1, further comprising: a suction operation inspection unit that performs an inspection on the suction operation based on the operation position acquired by the position acquisition unit.