JP2001156083A - Manufacturing method of semiconductor device and die bonding apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve collect changing frequency. SOLUTION: A die bonding apparatus 21 is provided with a dismounting jig 66 engaging with a collet 40 mounted to a shank 36, and a mounting jig 69 for mounting a new collet 40A to the shank 36 from which the collet 40 was dismounted. On changing collets, the collet mounted to the shank 36 is engaged with the dismounting jig 66 at a put-down device 30 of the die bonding apparatus 21 to remove the collet 40 from the shank 36. Then the shank 36 is moved to the position of the dismounting jig 69 by the put-down device, and the new collet 40A is mounted thereto. As the collet can automatically be changed, performance of frequency for changing collets can extremely be improved, damage and contamination on the die surface by the damage and the contamination of the collet can be protected, resulting in prevention of defective die bonding due to flawaand biassed abrasion of the collet.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device manufacturing technique, and more particularly, to a die bonding technique. The technology that is effective for technology

[0002]

2. Description of the Related Art In a method of manufacturing a semiconductor device, the following die bonding apparatus may be used in a die bonding step of fixing a die to a lead frame.
That is, the collet attached to the lower end of the collet shank is pressed against the upper surface of the die and held by vacuum suction, and is pressed onto the adhesive applied on the upper surface of the tab of the lead frame, so that the die adheres to the tab. It is fixed via the material layer.

[0003] As an example describing the die bonding technology, see "VLSI Packaging Technology (Lower)", pages 17 to P, issued on May 31, 1993 by Nikkei BP Co., Ltd.
22.

[0004]

In such a die bonding apparatus, it is necessary to increase the frequency of exchanging a collet in contact with the die surface in order to prevent scratches and contamination on the die surface. However, since the collet replacement requires labor, not only the work time is lengthened, but also there is a problem that errors due to human error and individual differences occur, and the frequency of collet replacement is inevitably reduced. Have been.

An object of the present invention is to provide a die bonding technique that can increase the frequency of collet replacement.

The above and other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

[0007]

The outline of a typical invention among the inventions disclosed in the present application is as follows.

[0008] That is, the die bonding apparatus includes a removing jig for engaging a collet attached to the collet shank, and an attaching jig for attaching a new collet to the collet shank from which the collet has been removed.

When the collet is replaced, the collet attached to the collet shank is engaged with the removal jig by the operation of the die bonding device and is removed from the collet shank. The collet shank from which the collet has been removed is moved to the position of the mounting jig by the operation of the die bonding device, and a new collet is mounted by the operation of the die bonding device. Therefore, according to the die bonding apparatus described above, the collet for vacuum-sucking the semiconductor die can be automatically replaced by the operation of the die bonding apparatus, so that the collet replacement frequency can be increased.

[0010]

FIG. 1 is a perspective view showing a die bonding apparatus according to an embodiment of the present invention. 2A and 2B show a collet, wherein FIG. 2A is a plan view, FIG. 2B is a front sectional view, and FIG. 2C is a bottom view. 3 shows a collet exchange device, (a) is a plan view, (b) is a side sectional view along the line bb of (a), (c) is a side surface along the line cc of (a) It is sectional drawing. FIG. 4 et seq. Are explanatory diagrams for explaining the operation.

In the present embodiment, the method of manufacturing a semiconductor device according to the present invention is configured such that the die bonding step is performed by the die bonding apparatus shown in FIG. The die bonding apparatus according to the present invention is configured to bond a die to a tab in each unit lead frame of a multiple lead frame.

As shown in FIG. 1, the multiple lead frame 11 is made of a conductive and heat conductive material such as an iron-based material such as 42 alloy or a copper-based material (copper or copper alloy) such as oxygen-free copper. A material having good properties is used and formed into a horizontally long rectangular flat plate shape by press working. The multiple lead frame 11 is formed in a multiple structure in which unit lead frames 12 are repeatedly formed in one direction and connected in a row. Each unit lead frame 12 has a tab 13 for fixing a die. Have been.

As shown in FIG. 1, the die 14, which is the other work, is supplied to the die bonding apparatus 21 while being held by the wafer ring 15 in the following process. That is, the die 14 is manufactured by forming a semiconductor integrated circuit in a state of a semiconductor wafer in a so-called pre-process in a semiconductor device manufacturing process. An adhesive sheet is adhered to the back surface of the semiconductor wafer on which the semiconductor integrated circuit is built. The wafer sheet attached to the wafer ring is divided into individual dies 14 in a dicing process. At this time, since the adhesive sheet is stuck, the individual dies 14 do not fall apart. The wafer sheet divided into the dies 14 is stretched from an adhesive sheet and mounted on the wafer ring 15. In the stretched wafer sheet, adjacent dies 14 are spaced from each other. Then, in this state, the group of dies 14 is supplied to the die bonding step, and the die bonding apparatus 2
1 pickup device 50.

The die bonding apparatus 21 includes a feeder 22 for feeding the multiple lead frames 11 as a workpiece in one direction (hereinafter, referred to as an X direction). The upstream end and the downstream end of the feeder 22 are provided. The unit is provided with a loading device 23 for supplying the multiple lead frames 11 to the feeder 22 and an unloading device 24 for discharging the bonded multiple lead frames 11 from the feeder 22. .

Downstream of the loading device 23 of the feeder 22, a silver paste application device 26 for applying a silver paste 25 as an adhesive to the tub 3 is provided. A dispenser 27 is connected to the silver paste application device 26. The silver paste application device 26 discharges a predetermined amount of the silver paste 25 by a control of the dispenser 27 and applies the silver paste 25 onto the tub 3.

Downstream of the silver paste application device 26 in the feeder 22, a put-down device 30 for bonding a die to a tub is provided. The put-down device 30 includes an X-axis robot 31, and the X-axis robot 31 is configured to reciprocate a stand 32 mounted thereon in a feed direction of the feeder 22 (hereinafter, referred to as an X direction). ing. A Y-axis robot 33 is installed on the stand 32. The Y-axis robot 33 is configured to reciprocate an arm 34 supported vertically downward in a direction orthogonal to the X direction (hereinafter, referred to as a Y direction). Have been. A Z-axis robot 35 is installed at the tip of the arm 34, and the Z-axis robot 35 is supported vertically downward by a collet shank (hereinafter, referred to as a shank).
36 is configured to reciprocate in a vertical direction (hereinafter, referred to as a Z direction). A collet 40 for holding the die 14 by vacuum suction is detachably attached to the tip of the shank 36.

In this embodiment, the collet 40 is shown in FIG.
It is configured as shown in FIG. That is, the collet 40 includes a main body 41 formed of a substantially cylindrical shape using rubber or resin and having an outer diameter larger than the outer diameter of the collet shank 36. The lower surface of the main body 41 has a frusto-conical suction surface portion. 42 are formed. A circular suction port 43 is provided concentrically at the center of the suction surface portion 42, and a suction hole 44 is provided on the center line of the column of the main body 41 so as to communicate with the suction port 43. On the center line of the cylinder of the main body 41, a shank mounting opening 45 is formed concentrically with the suction hole 44, and at the upper end of the shank mounting opening 45, an angle of attack 46 is formed in a conical shape in which the angle of attack 46 is widened upward. Is formed. In the present embodiment, the shape of the collet 40 is circular, but it is needless to say that the shape of the collet 40 is not limited to a circle, and is shown by an imaginary line in FIG. As described above, the shape of the collet 40 may be a shape that forms the overhang OH with respect to the collet shank 36.

X-axis robot 31 of put-down device 30
The wafer ring 15 is located on the opposite side of the feeder 22
A pick-up device 50 for picking up the dies 14 one by one is provided. An XY table 5 for moving the wafer ring 15 in the XY directions
1 is provided. Immediately below the XY table 51, push-up rods 52 for pushing up the dies 14 held by the wafer ring 15 one by one are provided. Above the XY table 51, a visual observation system 53 for detecting the quality of the dies 14 is provided. Have been.

The pickup device 50 is a ΘZ robot 54
The ΘZ robot 54 is configured to reciprocally rotate and move the arm 55 up and down. A collet 56 for holding the die by vacuum suction is provided at the tip of the arm 55.
Is attached. An alignment stage 57 is provided on one side of the XY table 51. The alignment stage 57 is configured to mechanically align the position of the die 14 with four blades.

A collet changing device 60 shown in FIGS. 1 and 3 is provided on one side of the pickup device 50. That is, as shown in FIGS. 1 and 3, the collet exchanging device 60 includes a frame (mounting frame) 61 having an open upper surface and formed in a substantially rectangular box shape in plan view. It is installed on a machine base (not shown) of the die bonding apparatus 21. Frame 61
A tray 62 having an open top surface and formed in a rectangular box shape in a plan view is placed on the inner bottom surface, and a handle 63 is provided on one end side (hereinafter, referred to as a front end side) of the upper end of the tray 62. It is bent. At the left end of the rear end wall of the tray 62, an intake 64 is opened over the entire height.
An inclined surface member 65 is mounted at a position facing the inlet 64 in the room so that the inclined surface faces the inlet 64.

The inclined surface member 6 on the upper surface of the frame 61
A removal jig 66 formed in a substantially rectangular flat plate shape is fixed horizontally just above 5, and a removal opening 67 is provided at the center of the rear end of the removal jig 66 toward the front. Notched. The removal opening 67 is formed in a semi-elliptical notch shape (U-groove shape) having an inner diameter slightly larger than the outer diameter of the shank 36 and smaller than the outer diameter of the collet 40, and is formed on the opening side. At the end, an angle of attack 68 is formed to extend rearward. The removal opening 67 of the removal jig 66 is not limited to the U-groove shape.
It may have a groove shape.

A mounting jig 69 is horizontally disposed on the right side of the removing jig 66 of the frame 61 and is detachably mounted. A pocket for accommodating the collet 40 is provided on the upper surface of the mounting jig 69. 70 (six in the illustrated example) are arranged in a matrix. The pocket 70 has an inner diameter substantially equal to that of the collet 40 and is formed in a cylindrical hole shape whose depth is substantially equal to the height of the collet 40. The mounting jig 69 is provided with a pocket 70 corresponding to each standard of the collet 40.
Are provided in plural standards, and are exchanged corresponding to the collet 40 to be used.

At the front side of the removal jig 66 of the frame 61, an attachment confirmation stage (hereinafter referred to as a confirmation stage) 71 is formed. The confirmation stage 71 is configured as a horizontal plane portion, and the height of the horizontal plane with respect to the Z-axis robot 35 is preset in the Z-axis robot 35 as a reference plane height.

Next, the die bonding process of the method of manufacturing a semiconductor device according to one embodiment of the present invention using the die bonding apparatus having the above-described configuration will be described.

The multiple lead frames 11 supplied from the loading device 23 to the feeder 22 are stepped forward one pitch at a time, reach the position of the silver paste coating device 26, and stop intermittently. When the tab 13 of the multiple lead frame 11 is intermittently stopped at the position of the silver paste application device 26, the silver paste 25 is applied on the tab 13 by the silver paste application device 26.

When the intermittent stop period of the step feed operation for the multiple lead frames 11 has elapsed, the multiple lead frames 11 are stepped again by the feeder 22. Thereafter, the above-described operation is repeated in the silver paste coating device 26, so that the silver paste 25 is sequentially applied to the tab 13 of each unit lead frame 12.

On the other hand, in the pickup device 50, X
The Y table 51 positions the non-defective die 14 on the wafer ring 15 directly above the push-up bar 52 based on observation by the visual observation system 53. Subsequently, the push-up bar 52 pushes up the good die 14. The pushed-up die 14 is held in vacuum by a collet 56, conveyed by an arm 55 to an alignment stage 57, and transferred to the alignment stage 57. In the alignment stage 57, the die 14 is mechanically aligned by four blades.

The collet 56 having the die 14 transferred to the alignment stage 57 returns just above the wafer ring 15 of the pickup device 50, receives the next die 14, and waits for the next operation.

The collet 40 mounted on the shank 36 of the put-down device 30 picks up the die 14 of the alignment stage 57 while holding it by vacuum suction.
The robot is conveyed to the put-down stage set above the robot 2 by the operation of the X-axis robot 31, the Y-axis robot 33, and the Z-axis robot 35.

When the tab 13 is intermittently stopped at the put down stage in accordance with the step feed to the multiple lead frame 11, the collet 40 is lowered by the Z-axis robot 35, and the die is placed on the silver paste 25 applied to the tab 13. 1
4 is pressed to adhere to the tab 13.

When the intermittent stop period of the stepwise feed operation for the multiple lead frames 11 has elapsed, the die 14 is
The collet 40 that has been emptied by bonding to the X-axis robot 3
1. It is moved to the alignment stage 57 by the operation of the Y-axis robot 33 and the Z-axis robot 35. After picking up the next die 14, the collet 40 is moved to the put down stage and waits for the next bonding operation.

By simultaneously performing the above operations, a silver paste application step, a pickup step, and a put-down step are performed for each unit lead frame 12 as the multiple lead frames 11 are stepped forward, respectively.
The die 14 is bonded (die-bonded) to the tab 13 with a silver paste 25.

If the surface of the suction surface 42 of the collet 40 is contaminated by dust or scum of the silver paste 25, the surface of the die 14 is damaged or contaminated. Also, if die bonding is performed by the collet 40 in a state where the collet 40 is scratched or unevenly abraded, the die 14 may be bonded to the tab 13 in a state of being inclined or displaced. In order to prevent such defects from occurring, it is desirable to increase the frequency of replacement of the collet 40.

In the present embodiment, the collet 40 is automatically replaced by utilizing the operation of the put-down device 30 to increase the frequency of replacing the collet 40. Is prevented. Less than,
A method of automatically replacing the collet 40 will be described.

When the collet 40 is automatically exchanged, the shank 36 of the put-down device 30 is moved to the position of the removal jig 66 of the collet exchange device 60 by the X of the put-down device 30.
The robot is moved by the operation of the axis robot 31, the Y-axis robot 33, and the Z-axis robot 35, and is inserted into the removal opening 67 of the removal jig 66 as shown in FIG. In this state, the upper surface of the collet 40 attached to the lower end of the shank 36 is attached to the removal opening 67 on the lower surface of the removal jig 66.
In a state of being engaged with the outer edge portion.

In this engaged state, when the shank 36 is raised by the operation of the Z-axis robot 35, the collet 40 is pulled out of the shank 36 by the removal jig 66 as shown in FIG. Removed. In other words, the overhang-shaped portion of the collet 40 is caught by the edge of the U-groove-shaped removal opening 67 of the removal jig 66, thereby being removed from the collet shank 36. The collet 40 removed from the shank 36 falls on the inclined surface of the inclined surface member 65, rolls on the inclined surface, and is stored in the tray 62.

The shank 36 from which the collet 40 has been removed by the removal jig 66 is moved to the position of the attachment jig 69 of the collet exchange device 60 by the X-axis robot 31, the Y-axis robot 33 and the Z-axis robot 35 of the put-down device 30. 5A, and as shown in FIG. 5A,
The collet held in the pocket 70 (hereinafter, referred to as a new collet 40A) is inserted into the shank mounting opening 45. At this time, since the angle of attack 46 is formed at the upper end of the shank attachment port 45, the shank 36 is inserted into the shank attachment port 45 even if there is some displacement.

Subsequently, as shown in FIG. 5B, when the shank 36 is raised by the Z-axis robot 35, the new collet 40A of the pocket 70 is attached to the lower end of the shank 36. become.

When the new collet 40A is attached to the lower end of the shank 36, the shank 36 is moved to the collet changing device 60 as shown in FIG.
Is moved to the position of the confirmation stage 71 by the operation of the X-axis robot 31, the Y-axis robot 33, and the Z-axis robot 35 of the put-down device 30.

Subsequently, as shown in FIG. 6B, the shank 36 is lowered by the Z-axis robot 35, and the suction surface portion 42 of the new collet 40A is pressed against the upper surface of the confirmation stage 71. In this case, the controller of the Z-axis robot 35 is measured by reading the amount of movement of the descent distance Z ₁ of the shank 36. Then, the controller calculates a difference (Z ₁ −Z ₀ ) between the measured descending distance Z ₁ and a preset reference descending distance Z _0, and determines whether the absolute value of the difference is within the range of the intersection Σ. Determine whether or not. That is, | Z ₁ −Z ₀ | ≦ Σ is calculated. If so, the shank 36 of the new collet 40A
The attachment to the shank 36 of the new collet 40A is determined to be defective when it is determined that the attachment to the shank 36 is out of the range of intersection.

If it is determined that the attachment of the new collet 40A to the shank 36 is defective, the shank 36 to which the new collet 40A is attached is removed from the removal jig 66.
X-axis robot 31, Y-axis robot 33 and Z
It is returned by the operation of the shaft robot 35, and the new collet 40A is removed by the above operation. When it is determined that the device is defective, the device is often not mounted. In such a case, the removal step may be performed.

Next, the shank 36 is moved to the position of the mounting jig 69 by the operation of the X-axis robot 31, the Y-axis robot 33, and the Z-axis robot 35.
New collet 40 held in a separate pocket 70
A new collet 40A is inserted into the shank mounting opening 45 of A by the operation described above, and another new collet 40A is mounted on the lower end of the shank 36.

Another new collet 40A is a shank 36
When it is attached to the lower end of the
Is moved again to the position of the confirmation stage 71 by the operation of the X-axis robot 31, the Y-axis robot 33 and the Z-axis robot 35, and the attachment is confirmed by the operation described above.

By repeating the above operation, the new collet 40A is properly attached to the lower end of the shank 36. However, the new collet 40A is normally properly mounted on the lower end of the shank 36 by the first mounting operation. That is, since the number of collets can be replaced by the number of new collets 40A prepared in the mounting jig 69, the replacement frequency can be increased.

According to the above embodiment, the following effects can be obtained.

1) Since the collet exchange operation can be automatically performed by automatically performing the exchange operation of the collet to the shank, damage and contamination of the die surface due to damage and contamination of the collet can be prevented. In addition, it is possible to prevent die bonding failures caused by scratches and uneven wear of the collet.

2) According to the above 1), the quality and reliability of the die bonding process and the production yield can be improved,
Consequently, the productivity of the method for manufacturing a semiconductor device can be increased.

3) Since the collet exchange operation is automatically performed by utilizing the operation of the die bonding apparatus itself, it is not necessary to provide an operating mechanism in the collet exchange apparatus. It is possible to suppress an increase in the cost of the manufacturing method of the semiconductor device.

Although the invention made by the inventor has been specifically described based on the embodiment, the invention is not limited to the embodiment, and various modifications can be made without departing from the gist of the invention. Needless to say.

For example, the mounting confirmation stage is not limited to confirming the descending distance of the shank based on the measurement value measured by the operation amount of the Z-axis robot. May be configured. Further, the attachment confirmation stage may be omitted.

The present invention is not limited to the configuration in which the collet of the put-down device is automatically replaced, but may be configured to automatically replace the collet of the pickup device. To automatically change the collet of the pickup device,
The operation of the ΘZ robot can be used. Desirably, both the put-down device and the collet of the pick-up device are automatically replaced.

In the above description, the invention made by the present inventor has been mainly described with respect to the case where the die, which is the field of application as the background, is die-bonded to the tab of the lead frame. However, the present invention is not limited to this. Can be applied to a general die bonding technique of vacuum-adsorbing with a collet.

[0053]

The effects obtained by typical aspects of the invention disclosed in the present application will be briefly described as follows.

By automatically performing the work of exchanging the collet for the shank, the frequency of exchanging the collet can be increased, thereby preventing the damage or contamination of the die surface due to the damage or contamination of the collet. Can also
It is possible to prevent the occurrence of defective die bonding due to the damage and uneven wear of the collet.

[Brief description of the drawings]

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

FIG. 2 shows a collet, (a) is a plan view,
(B) is a front sectional view, and (c) is a bottom view.

3 (a) is a plan view, FIG. 3 (b) is a side sectional view taken along line bb of FIG. 3 (a), and FIG.
(C) is a side sectional view taken along line cc of (a).

FIGS. 4A and 4B are side sectional views showing a collet removing operation, in which FIG. 4A shows an engaged state, and FIG. 4B shows a state after removal.

FIGS. 5A and 5B are side sectional views showing a mounting operation of the collet, in which FIG. 5A shows an inserted state, and FIG. 5B shows a state after mounting.

FIGS. 6A and 6B are side cross-sectional views showing a collet attachment confirmation operation, in which FIG. 6A shows a state before measurement and FIG. 6B shows a state after measurement.

[Explanation of symbols]

11: Multiple lead frame, 12: Unit lead frame, 13: Tab, 14: Die (semiconductor die), 15: Wafer ring, 21: Die bonding device, 22: Feeder, 23: Loading device, 24: Unloading device , 25 ... Silver paste (adhesive) 26 ... Silver paste coating device, 27 ... Dispenser, 30 ... Put down device, 31 ... X axis robot, 32 ... Stand, 33 ... Y axis robot, 34 ... Arm, 35 ... Z axis Robot, 36 ...
Collet shank, 40 ... Collet, 40A ... New collet, 41 ... Main body, 42 ... Suction surface part, 43 ... Suction port,
44: suction hole, 45: shank mounting port, 46: angle of attack, 50: pickup device, 51: XY table, 5
2 ... push-up rod, 53 ... visual observation system, 54 ... Z robot, 55 ... arm, 56 ... collet, 57 ... alignment stage, 60 ... collet exchange device, 61 ... frame, 62 ... tray, 63 ... handle, 64 ... take Entrance, 65 ...
Inclined surface member, 66: Removal jig, 67: Removal port, 68: Angle of attack, 69: Mounting jig, 70: Pocket, 71: Mounting confirmation stage.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroshi Maki 3-3-2 Fujibashi, Ome City, Tokyo Inside Hitachi Tokyo Electronics Co., Ltd. (72) Inventor Koji Hosaka 3-2-2 Fujibashi, Ome City, Tokyo Hitachi East Kyoto Electronics Co., Ltd. F-term (reference) 5F047 FA08 FA79

Claims (4)

[Claims] 1. A collet attached to a collet shank and vacuum-sucking a semiconductor die is engaged with a removal jig by an operation of a die bonding apparatus, is removed from the collet shank, and the collet shank from which the collet is removed is removed. The die is moved to the position of the mounting jig by the operation of the die bonding apparatus, a new collet is mounted by the operation of the die bonding apparatus, and the collet shank to which the new collet is mounted is operated by the operation of the die bonding apparatus. The method according to claim 1, wherein the semiconductor device is moved to an attachment confirmation stage to confirm attachment of a new collet. 2. The method according to claim 1, wherein the mounting of the new collet is confirmed by measuring a vertical moving distance of the collet shank by the operation of the die bonding apparatus. . 3. A removal jig attached to a collet shank for engaging a collet for vacuum-sucking a semiconductor die,
A mounting jig for mounting a new collet to the collet shank from which the collet has been removed, wherein the removing jig and the mounting jig are respectively arranged in a movable range of the collet shank. Die bonding equipment. 4. The die bonding apparatus according to claim 3, wherein an attachment confirmation stage for confirming attachment of a new collet attached to the collet shank is provided in a movable range of the collet shank. .