JP2004247377A - Die bonder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a die bonder that can be contrived to reduce its cost. <P>SOLUTION: This die bonder is provided with a dispenser 162 which applies a bonding agent to the bonding point of a lead frame, and a bonding head 124 which picks up a chip and transfers the chip to the bonding point coated with the bonding agent. An elevating/lowering unit 123 is provided with a mobile base 151 supported through a unit elevating/lowering mechanism 153, a first base 142 which moves downward as the base 142 is pressed by the mobile base 151 when the base 151 is lowered by means of the unit elevating/lowering mechanism 153, and a second base which can move freely in the vertical direction. The unit 123 is also provided with a cam mechanism 176 which is actuated when the mechanism 176 is pressed by the mobile base 151 raised by the unit elevating/lowering mechanism 153 and moves the second base downward. The bonding head 124 is installed to the first base 142 and the dispenser 162 is installed to the second base. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a die bonding apparatus for bonding a chip such as a semiconductor to a lead frame.
[0002]
[Prior art]
Conventionally, when bonding a semiconductor chip to a lead frame, a die bonding apparatus has been used.
[0003]
The die bonding apparatus includes a transfer rail on which a lead frame is transferred, a feed mechanism for feeding the lead frame on the transfer rail at a pitch, a dispenser for applying an epoxy agent to bonding points of the lead frame in advance, and a wafer ring. The stage includes a stage for supporting, a push-up mechanism for pushing up a chip on a sheet stretched over a wafer ring from below, and a bonding head for picking up the chip pushed up by the push-up mechanism.
[0004]
The dispenser is provided in a dispenser driving mechanism that moves the dispenser to each bonding point set on the lead frame, and is connected to the dispenser driving mechanism via a dispenser elevating mechanism provided with a driving shaft that moves the dispenser up and down. Supported.
[0005]
The bonding head is provided in a head drive mechanism that moves the bonding head between a pickup point and a bonding point of a lead frame, and is connected via a head elevating mechanism having a drive shaft provided in the head drive mechanism. It is supported.
[0006]
[Problems to be solved by the invention]
However, such a die bonding apparatus requires a drive shaft for raising and lowering the dispenser and a drive shaft for raising and lowering the bonding head, resulting in an increase in cost.
[0007]
The present invention has been made in view of such a conventional problem, and an object of the present invention is to provide a die bonding apparatus capable of reducing cost.
[0008]
[Means for Solving the Problems]
In order to solve the above problems, in a die bonding apparatus according to the present invention, there is provided a dispenser for applying a bonding agent to a bonding point of a lead frame, and bonding for picking up a chip and transferring the chip to the bonding point where the bonding agent is applied. In a die bonding apparatus having a head, a movable base supported via a lifting mechanism by a lifting unit moved in a horizontal direction by a driving mechanism, and a movable base lowered by the lifting mechanism A first base movably supported up and down, a second base movably supported vertically, and the second base when actuated by being pressed by the movable base raised by the elevating mechanism. A cam mechanism that moves downward, and the dispenser is mounted on one of the first base and the second base. Rutotomoni were other is provided with the bonding head.
[0009]
As an example, a case where a bonding head is provided on a first base of a lifting unit and a dispenser is provided on a second base will be described. However, a dispenser is provided on a first base, and a bonding head is provided on a second base. Can obtain the same effect.
[0010]
When applying the bonding agent to the bonding point of the lead frame, the drive unit moves the elevating unit to recognize the lead frame, and then disposes a dispenser provided in the elevating unit on the bonding point. In this state, the movable base is raised by the lifting mechanism of the lifting unit, and the cam mechanism is operated by the movable base to move the second base downward. Accordingly, the dispenser provided on the second base is lowered, and the dispenser applies a bonding agent to the bonding point.
[0011]
On the other hand, when transferring the chip picked up by the bonding head to the bonding point to which the bonding agent has been applied, the lifting mechanism is moved by the driving mechanism, and the bonding head provided in the lifting unit is moved onto the bonding point. Deploy. In this state, the movable base is lowered by the lifting mechanism of the lifting unit, and the first base is pressed by the movable base to move downward. As a result, the bonding head provided on the first base is lowered, and the chip held by the bonding head is placed on the bonding point.
[0012]
As described above, by raising or lowering the movable base by the lifting mechanism provided in the lifting unit, the bonding head or the dispenser provided on the first base and the second base is selectively lowered. Further, the dispenser and the bonding head are moved by a drive mechanism that moves the elevating unit.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a die bonding apparatus 1 according to the present embodiment. The die bonding apparatus 1 is an apparatus for bonding a chip 2 such as a semiconductor to a lead frame 3.
[0014]
As shown in FIG. 2, the die bonding apparatus 1 is provided with a pair of slide rails 12, 12 extending in the Y direction 11, and the two slide rails 12, 12 are arranged from the near side. It extends to the back side. A pair of wafer support rails 13 is provided on the inner side of both slide rails 12, and a wafer changer 14 is provided on the front side thereof.
[0015]
The two wafer support rails 13 are formed in an L-shaped cross section so that the wafer ring 21 can slide along the wafer support rails 13 while supporting the edge of the wafer ring 21. It is configured. A holding position 22 for holding the supported wafer ring 21 is set between the two wafer supporting rails 13, 13. Immediately below the holding position 22, as shown in FIG. A stage 24 having a circular groove for holding the wafer ring 21 at the holding position 22 in a state where the sheet 23 stretched on the lower surface is sucked from the lower surface is disposed. It is supported so as to be able to move up and down by a lifting mechanism. The stage 24 is formed in a ring shape with an open center.
[0016]
As shown in FIG. 3, the wafer changer 14 includes an upright tower 41, a cassette lifter 42 slidably supported by the tower 41, and a lift mechanism 43 for moving the cassette lifter 42 up and down along the tower 41. And The cassette lifter 42 is configured to be moved vertically by the lift mechanism 43. The upper surface of the cassette lifter 42 constitutes a support surface 47 for supporting a detachably set wafer cassette 46, and a positioning portion 48 for positioning the wafer cassette 46 protrudes from the support surface 47. I have.
[0017]
The wafer cassette 46 is formed of a box having handles 51, 51, and internally has a plurality of upper and lower wafer storage sections 52,. Each wafer accommodating portion 52 is open on the wafer support rail 13 side. By operating the lift mechanism 43, the entrance of each of the wafer accommodating portions 52,... Is selectively moved up and down in accordance with the height position of the wafer support rails 13, 13, as shown in FIG. As described above, the wafer cassette 46 can be lowered below the height position of the push-up mechanism 103 which will be described later, which is at a lower position than the wafer support rails 13, 13.
[0018]
As shown in FIG. 4, a wafer ring moving mechanism 61 for moving the wafer ring 21 of the wafer support rails 13, 13 is provided on the side of the wafer support rails 13, 13. The wafering moving mechanism 61 includes a replacement rail 62 extending along the wafer support rails 13, 13, and a slider 63 slidably supported by the replacement rail 62. The slider 63 is configured to be moved along the replacement rail 62 by a drive mechanism including a belt and a pulley. An extending exchange arm 64 is provided. A gripper 65 for holding the wafer ring 21 is provided at the end of the exchange arm 64 so as to be freely opened and closed.
[0019]
Thereby, the wafer ring 21 supported by the wafer support rails 13 at the holding position 22 is pressed by the gripper 65 in a closed state, and is positioned at the height position of the wafer support rails 13. The wafer cassette 46 is configured to be accommodated in the wafer accommodating section 52. Further, the wafer ring 21 of the wafer accommodating portion 52 at the height position of the wafer support rails 13, 13 is pulled out while being held by the gripper 65, and is moved along the wafer support rails 13, 13 to hold the wafer ring 21. It is configured to be able to move to the position 22.
[0020]
As shown in FIG. 1, a first Y table 71 is slidably supported on the rear side of the slide rails 12, and a second Y table 72 is slidably supported on the front side. I have.
[0021]
A tray drive mechanism 81 is provided above the second Y table 72, and a drive mechanism that moves the second Y table 72 along the slide rails 12, 12 is provided in the tray drive mechanism 81. I have. As shown in FIG. 2, the tray driving mechanism 81 is provided with support arms 82, 82 extending toward the first Y table 71 at a position higher than the wafer support rails 13, 13. The support arms 82, 82 are provided with work support rails 85, 85 extending in the X direction 84 for supporting the strip-shaped lead frame 3 received from the work loader 83.
[0022]
The tray drive mechanism 81 is provided with a drive arm 91 which is slid in the X direction 84 and driven up and down in the Z direction 86 by a built-in drive mechanism. The length dimension is set to reach between the support rails 85, 85. At the end of the drive arm 91, a work tray 92 is provided for holding the lead frame 3 supported by the work support arms 82, 82 while holding the lead frame 3 mounted thereon.
[0023]
As a result, the lead frame 3 sucked and held on the work tray 92 is moved to an arbitrary position in the X direction 84 and the Y direction 11 by the tray drive mechanism 81 and moved onto the wafer ring 21 held by the stage 24. It is configured to be able to. When the lead frame 3 is ejected out of the work supporting rails 85, the work tray 92 is lowered to release the residual pressure of the vacuum for sucking the lead frame 92. Is configured to prevent rubbing.
[0024]
As shown in FIGS. 1 and 5, a lower arm 101 extending toward the first Y table 71 is provided below the second Y table 72. At the tip of the lower arm 101, a push-up mechanism 103 is provided via a push-up section moving mechanism 102. The push-up mechanism 103 is driven in the X direction 84 by the push-up section moving mechanism 102, and The 2Y table 72 is driven in the Y direction 11 by a driving mechanism that moves along the slide rails 12, 12, and can be moved to a pickup point 104 for picking up the chip 2. The push-up mechanism 103 includes a push-up stage 105 that slides on the lower surface of the sheet 23 of the wafer ring 21 and a push-up pin in the stage 105 while being disposed in the opening of the stage 24. By moving up, the chip 2 at the pickup point 104 can be pushed up higher than the surrounding chips 2,.
[0025]
The push-up mechanism 103 is provided at a position separated by a predetermined distance from the work tray 92 toward the first Y table 71. Thereby, the length in the Y direction 11 from the pickup point 104 on the push-up pin of the push-up mechanism 103 to the bonding point 111 of the lead frame 3 held on the work tray 92 is set to be always constant. The bonding point 111 determined by the position of the work tray 92 and the pickup point 104 determined by the position of the push-up mechanism 103 do not overlap.
[0026]
As shown in FIG. 1, the first Y table 71 is provided with a unit driving mechanism 121, and the unit driving mechanism 121 is provided with the first Y table 71 on the slide rails 12, 12. A drive mechanism is provided that moves along. The unit drive mechanism 121 is provided with an elevating unit 123 on the second Y table 72 side via an X-direction driving mechanism 122. The chip 2 is detachably attached to the elevating unit 123. Bonding head 124 is provided. Accordingly, when picking up the chip 2 of the wafer ring 21, the bonding head 124 is moved in accordance with the chip 2 to be picked up, and the pickup point 104 of the chip 2 by the bonding head 124 is fixed to the wafer ring 21. The stage 24 is configured to be variable.
[0027]
As shown in FIG. 6, an extruding claw 132 for sending out the bonded lead frame 3 from above the work supporting rails 85, 85 is tiltably supported on the base 131 of the elevating unit 123. A recognition camera 133 is provided on the side of the push claw 132, and is configured to acquire an image of the lower part of the elevating unit 123 and perform image analysis (position and angle correction) by a control device (not shown). ing.
[0028]
On the side of the recognition camera 133, slide rails 141 extending vertically are provided. On the slide rail 141, an L-shaped first base 142 is vertically moved via a slider. It is freely supported. The first base 142 is urged upward by a coil spring (not shown), while being in contact with a stopper 144 provided on a top plate 143 of the elevating unit 123, the upper limit position is regulated. The bonding head 124 is provided on the first base 142.
[0029]
A movable base 151 is provided on a side portion of the first base 142, and the movable base 151 is also supported by the slide rail 141 so as to be vertically movable. A unit elevating mechanism 153 composed of a ball screw operated by a drive motor 152 is provided on a side portion of the movable base 151, and the movable base 151 moves up and down in accordance with the rotation of the drive motor 152. Thus, when the movable base 151 is lowered, the contact portion 155 presses the first base 142 downward, and moves the first base 142 together with the bonding head 124 downward.
[0030]
As shown in FIG. 7, a second base 161 is supported on the side of the base 131 of the elevating unit 123 through a vertically extending slide rail (not shown) so as to be vertically movable. The base 161 is provided with a dispenser 162 for applying an epoxy agent as a bonding agent to the lead frame 3. The second base 161 is urged downward by a coil spring 163, and an L-shaped piece 164 provided at an end of the second base 161 is rotatable on a side plate 165 of the lifting unit 123. A cam follower 167 at one end of a cam plate 166 rotatably supported by the cam follower 167 from above.
[0031]
The other end of the cam plate 166 is urged downward by a coil spring 172 supported by a bottom plate 171, and this other end abuts on an L-shaped piece 173 provided on the side plate 165. In this state, downward rotation is restricted. As shown in FIG. 6, an operation plate 175 extending from the movable base 151 is in sliding contact with a cam follower 174 provided at the other end of the cam plate 166 from below, and a cam mechanism 176 is formed. ing. Accordingly, when the movable base 151 is raised and the operation plate 175 presses and pushes up the other end of the cam plate 166, one end of the cam plate 166 allows the second base 161 to descend. Then, the second base 161 is configured to move downward together with the dispenser 162.
[0032]
This embodiment according to the above configuration will be described with reference to the flowcharts shown in FIGS.
[0033]
That is, when a control device (not shown) executes the bonding process, the strip-shaped lead frame 3 is supplied from the work loader 83 to the work supporting rails 85, 85 and held on the work tray 92 (S1). The recognition camera 133 of the elevating unit 123 is moved onto the frame 3 to acquire an image of the lead frame 3, and the bonding points 111 at various locations are recognized (S2). The work tray 92 is moved so that the recognized bonding point 111 is separated from the pickup point 104 of the chip 2 by a predetermined offset amount (S3).
[0034]
Then, the push-up pin of the push-up mechanism 103 driven by the push-up section moving mechanism 102 is moved to the pickup point 104 (S4). At this time, since the distance of the pickup point 104 to the bonding point 111 in the Y direction 11 is determined, the movement is performed only in the X direction 84.
[0035]
Next, the dispenser 162 of the lifting unit 123 is moved onto the lead frame 3 to apply an epoxy agent to each of the bonding points 111,... (S5).
[0036]
Specifically, the elevating unit 123 is moved to the bonding point 111 by the unit driving mechanism 121, and the dispenser 162 provided in the elevating unit 123 is arranged on the bonding point 111. In this state, the movable base 151 is moved up by the unit elevating mechanism 153 of the elevating unit 123, and the cam mechanism 176 is operated by the movable base 151 to move the second base 161 downward. Accordingly, the dispenser 162 provided on the second base 161 can be lowered, and the bonding agent can be applied to the bonding point 111 by the dispenser 162.
[0037]
Thereafter, the recognition camera 133 of the lifting unit 123 is moved on the wafer fixed on the stage 24 to recognize the position of the chip 2 to be picked up (S6), and the bonding head 124 is moved to the pickup point 104 to move the bonding head. The chip 2 is picked up at 124 (S7).
[0038]
Specifically, the elevating unit 123 is moved by the unit driving mechanism 121, and the bonding head 124 provided in the elevating unit 123 is arranged on the pickup point 104. In this state, the movable base 151 is lowered by the unit lifting mechanism 153 of the lifting unit 123, and the movable base 151 presses the first base 142 to move downward. Accordingly, the bonding head 124 provided on the first base 142 is lowered, and the chip 2 at the pickup point 104 can be picked up by the bonding head 124.
[0039]
Then, the bonding head 124 is moved to the bonding point 111, and the chip 2 is placed and fixed on the epoxy applied to the bonding point 111 (S8).
[0040]
Also in this case, the elevating unit 123 is moved by the unit driving mechanism 121, and the bonding head 124 provided in the elevating unit 123 is arranged on the bonding point 111. In this state, the movable base 151 is lowered by the unit lifting mechanism 153 of the lifting unit 123, and the movable base 151 presses the first base 142 to move downward. Accordingly, the bonding head 124 provided on the first base 142 can be lowered, and the chip 2 held by the bonding head 124 can be placed at the bonding point 111.
[0041]
As described above, the movable base 151 is moved up or down by the unit elevating mechanism 153 provided in the elevating unit 123, so that the bonding head 124 provided on the first base 142 and the dispenser provided on the second base 161 are provided. 162 can be selectively lowered.
[0042]
Therefore, the configuration can be simplified as compared with the related art in which a dispenser elevating mechanism for elevating and lowering the dispenser 162 and a head elevating mechanism for elevating and lowering the bonding head 124 are separately provided. Further, since the unit elevating mechanism 153 can be shared, the number of drive shafts for elevating and lowering the dispenser 162 and the bonding head 124 can be reduced, and a cost advantage can be obtained. Further, the weight of the entire apparatus can be reduced.
[0043]
In addition, the dispenser 162 and the bonding head 124 can be moved by the unit drive mechanism 121 that moves the elevating unit 123. Thereby, the structure can be further simplified.
[0044]
Then, it is determined whether the bonding to the lead frame 3 held on the work tray 92 has been completed (S9), and the above steps S3 to S8 are repeated until the bonding is completed. Is tilted and the lead frame 3 is pushed out to the right side of the apparatus by the pushing claws 132 (S10), and the process returns to the main routine and waits until the next bonding process starts.
[0045]
FIG. 10 is a flowchart showing a wafer replacement process executed when the wafer ring 21 is replaced. When the bonding of the chips 3 of the wafer ring 21 held on the stage 24 is completed (SB1), the first and second Ys are replaced. The tables 71 and 72 are moved to the back side along the slide rails 12 and 12 to open the upper space of the wafer changer 14 (SB2), and the empty wafer accommodating portion 52 of the wafer cassette 46 is moved by the cassette lifter 42 to the wafer support rail. After being adjusted to the height position of 13, 13 (SB3), the stage 24 is lowered to release the holding state of the wafer ring 21 (SB4), and the wafer ring 21 is held by the gripper 65 in the closed state. 52 (SB5).
[0046]
Then, the wafer cassette 46 is moved up and down by the cassette lifter 42 so that the wafer accommodating portion 52 accommodating the unused wafer ring 21 is positioned at the height of the wafer support rails 13 (SB6). Is gripped by the gripper 65 and pulled out of the wafer accommodating portion 52, and is moved along the wafer support rails 13 to the holding position 22 (SB7), and the stage 24 is raised to fix the wafer ring 21. After that (SB8), the first and second Y tables 71 and 72 are returned to their home positions, and the wafer cassette 46 is lowered by the cassette lifter 42 to a position lower than the height position of the push-up mechanism 103 (SB9). Return to the main routine.
[0047]
【The invention's effect】
As described above, in the die bonding apparatus according to the present invention, the movable base is raised or lowered by the lifting mechanism provided in the lifting unit, so that the bonding head or the dispenser provided on the first base and the second base are provided. Can be selectively lowered.
[0048]
Therefore, the number of drive shafts can be reduced and a cost merit can be obtained as compared with the related art that requires a drive shaft for raising and lowering the dispenser and a drive shaft for raising and lowering the bonding head. Further, the weight of the entire apparatus can be reduced.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing an embodiment of the present invention.
FIG. 2 is a plan view corresponding to FIG.
FIG. 3 is a front view of a main part showing the wafer changer of the embodiment.
FIG. 4 is a plan view of a main part showing the wafer changer of the embodiment.
FIG. 5 is an explanatory diagram showing a relationship between a pickup point and a bonding point according to the embodiment.
FIG. 6 is a front view of a main part showing the lifting unit according to the embodiment.
FIG. 7 is a side view of FIG. 6;
FIG. 8 is a flowchart showing a bonding process of the embodiment.
FIG. 9 is a flowchart following FIG. 8;
FIG. 10 is a flowchart showing a wafer exchange process of the embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Die bonding apparatus 2 Chip 3 Lead frame 21 Wafer ring 81 Tray moving mechanism 92 Work tray 104 Pickup point 111 Bonding point 121 Unit driving mechanism 123 Elevating unit 124 Bonding head 142 First base 151 Movable base 153 Unit elevating mechanism 161 Second base 162 Dispenser 176 Cam mechanism

Claims (1)

In a die bonding apparatus including a dispenser that applies a bonding agent to a bonding point of a lead frame, and a bonding head that picks up a chip and transfers the chip to the bonding point where the bonding agent is applied,
The lifting unit moved horizontally by the drive mechanism,
A movable base supported via a lifting mechanism,
A first base supported by the movable base lowered by the elevating mechanism and vertically movable to be moved downward by being pressed by the movable base;
A second base movably supported up and down,
A cam mechanism that moves the second base downward when pressed by the movable base raised by the elevating mechanism to operate;
A die bonding apparatus, wherein the dispenser is provided on one of the first base and the second base and the bonding head is provided on the other.

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