JP2658915B2 - Semiconductor chip transfer equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor chip transfer apparatus for transferring a semiconductor chip separated and divided from a wafer, attached to a resin sheet and having electronic circuit elements and electronic circuits formed thereon, to a stage of a die bonding apparatus. .

[0002]

2. Description of the Related Art Generally, a die bonding apparatus is peeled off one by one from a resin sheet to which a plurality of semiconductor chips on which electronic circuit elements and electronic circuits are formed are pasted by a tool and transferred to a base of a lead frame or a ceramic package. This is a type of semiconductor device assembling apparatus for bonding and fixing semiconductor chips.

Although not shown in the drawings, a semiconductor chip transfer device attached to the die bonding apparatus pushes up a needle from below a resin sheet to which a plurality of semiconductor chips are arranged vertically and horizontally, peels off the semiconductor chips, and removes the semiconductor chips at a predetermined height. In this apparatus, the semiconductor chip is pushed up, the pushed up semiconductor chip is sucked by a die collet having a vacuum suction hole, and the die collet is moved to a stage of a die bonding apparatus to release the vacuum, thereby transferring the semiconductor chip to the stage.

As one of the adjustment operations of the semiconductor chip transfer apparatus, there is a height adjustment of a needle and a collet which are tools. This adjustment operation is an adjustment operation for determining to which position the needle should be raised and the collet lowered to which position to hold the semiconductor chip by suction. If this adjustment work is not performed properly, for example, the semiconductor chip is mounted diagonally on the die collet, the position to be mounted on the base is shifted, or the semiconductor chip due to the impact due to excessive pushing up of the needle A minute crack may be generated to cause a crack during resin sealing.

Conventionally, this adjustment work method involves visually observing the height position of a semiconductor chip pushed up by a needle with monoculars or the like, and confirming whether or not the semiconductor chip is at a normal position or horizontal, and checking the height of the needle. Had to adjust. However, this adjustment requires a long time and requires considerable skill. Such a device having a height adjusting mechanism that does not require a long time and does not require a skill is disclosed in
No. 93144, No. 9.

FIG. 4 is a diagram showing an example of a conventional semiconductor chip transfer device. As shown in FIG. 4, a semiconductor chip transfer device having this height adjustment mechanism attaches a dummy conductive detection plate 21 to a holder 22 instead of a resin sheet to which a semiconductor chip is attached, and moves the needle 2 up and down.
3 or the die collet 24 is the conductive detection plate 21
Needle height position detection circuit 2 for detecting contact with the needle
6 and a die collet height position detection circuit 25 are provided.

The tool height adjustment in the semiconductor chip transfer apparatus is performed before the main work when the lot of the wafer before being separated into the semiconductor chips changes, when the die collet or the needle is exchanged, or when the wafer is changed to a different kind of wafer. This operation is performed in advance, and the main work is performed after adjusting the lower limit height position of the die collet 24 and the upper limit height position of the push-up needle 23 each time.

In this method of adjusting the tool height position, first, a conductive detection plate 21 is attached to a holder 22 at a position where a resin sheet and a semiconductor chip are placed. Next, the die collet 24 is lowered and the needle 23 is raised. As a result, the die collet 24 and the needle 23 come into contact with the conductive detection plate 21, and the collet height position detection circuit 25 and the needle height position detection circuit 26
Are closed, and a current flows from the DC power supply. Due to this conduction, the operation mechanism of the die collet 24 and the push-up needle 23 stops. Next, the die collet 24 and the needle 23
The tool height position is automatically obtained from the stop position of the tool and the height position of the conductivity detection plate 21, and the detected data is used as a reference height to correct the tool origin position.

As described above, by quantitatively detecting the height positions of the die collet and the needle, it is possible to adjust the height in a very short time without any skill without any skill.

[0010]

The tool height position adjusting mechanism in the above-described conventional chip transfer apparatus can be adjusted in a very short time without any skill without any skill, but it is necessary to change wafer lots, change tools, or use different types of tools. Each time the wafer is changed, the die bonding apparatus must be stopped and the height position of the tool must be adjusted, which causes an operating loss to the die bonding apparatus.

[0011] Further, although the thickness of the semiconductor chip which has been polished and processed on both sides and is divided does not vary, the thickness of the member attached to the resin sheet is not uniform as compared with the conductive detection plate. Therefore, even if the height of the tool is adjusted with the conductive detection plate, there is a concern that minute cracks may be generated in the semiconductor chip due to excessive pushing of the needle.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a semiconductor chip transfer apparatus capable of increasing the operating rate of a die bonding apparatus and transferring a semiconductor chip without generating a minute crack.

[0013]

A feature of the present invention is that a resin sheet having a plurality of semiconductor chips arranged vertically and horizontally is applied to the front surface with an adhesive applied thereto and a conductive film is adhered to the back surface,
A frame member that surrounds the plurality of semiconductor chips attached to the resin sheet and holds the periphery of the resin sheet so as not to be loosened, a holding table on which the frame member is placed, and an upper part from below the holding table. A needle for pushing up the semiconductor chip from the resin sheet by pushing up to a predetermined position, a vertical drive mechanism for vertically moving the needle, and a die collet for vertically moving a die collet for sucking and holding the semiconductor chip pushed up A mechanism, a detection circuit for detecting that the needle comes into contact with the conductive film of the resin sheet and outputting a signal, and inputting the signal of the detection circuit to temporarily suspend the needle push-up operation, and After lowering the collet and bringing the collet into contact with the upper surface of the semiconductor chip, the half of the collet is positioned at the height of the lower surface of the die collet. A height position obtained by adding the thickness of the body chip is calculated, and the needle temporarily suspended to the obtained position is thrust up to break through the resin sheet and the conductive film to make contact with the lower surface of the semiconductor chip and the needle. A control device for raising the semiconductor chip to the predetermined position while holding the needle between the needle and the die collet.

Further, it is desirable that the speed of the needle after the temporary stop is reduced from the speed before the temporary stop.

[0015]

Next, the present invention will be described with reference to the drawings.

FIG. 1 is a view showing an embodiment of a semiconductor chip transfer apparatus according to the present invention. This semiconductor chip transfer device,
As shown in FIG. 1, an adhesive for applying a plurality of semiconductor chips 27 arranged vertically and horizontally is applied to the front surface and a conductive film 3 is adhered to the back surface. A frame 9 that surrounds the semiconductor chip 27 and holds the periphery of the resin sheet 2 so as not to be loosened, a holding table 9a on which the frame 9 is placed, and a semiconductor chip that is pushed upward from below the holding table 9a to a predetermined position. A needle 4 for peeling the semiconductor chip 27 from the resin sheet 2, a vertical drive mechanism 8 for vertically moving the needle 4, a die collet moving mechanism 7 for vertically moving the die collet 5 for sucking and holding the semiconductor chip 27 that has been pushed up, A needle height position detection circuit 1 for detecting that the needle 4 contacts the conductive film 3 and outputting a signal;
Is input to lower the dicollet 5 so as to contact the upper surface of the semiconductor chip 27 and temporarily suspend the upward movement of the needle 4. After this operation, the dicollet is adjusted to the thickness of the semiconductor chip whose upper surface is in contact with the die collet 5. A height position obtained by adding the height position of the lower surface of 5 is calculated, and the vertical drive mechanism 8 is restarted at the calculated height position, the needle 4 is pushed up and the resin sheet 2 and the conductive film 3 are pierced and the semiconductor chip is pierced. A control unit 6 is provided for raising the semiconductor chip to the predetermined position while holding and holding the lower surface and the tip of the semiconductor chip 27 between the die collet 5 and the needle 4.

Although not shown in the drawings, a turning arm for moving the semiconductor chip adsorbed on the die collet 5 onto the stage of the die bonding apparatus is attached to the housing of the die collet moving mechanism 7. .

Here, a sheet member composed of the resin sheet 2 and the attached conductive film 3 is made of a resin base material such as vinyl chloride, polypyroprene, or the like, which is made of conductive carbon, tin oxide, or indium oxide. The filler may be dispersed, but in consideration of the variation in sheet resistance, it is preferable to attach an inexpensive metal foil such as an inexpensive aluminum wheel to the resin base material. Further, the needle height position detection circuit 1 is composed of a DC power supply for supplying a current to a closed circuit due to the contact between the needle 4 and the conductive film 3, and a shunt resistor for obtaining a detection voltage by the flowing current.

The control unit 6 includes pulse motors 15a, 15b
Power supply unit 1 that supplies pulsed power to rotate
1 and a calculation unit 12 for calculating the amount of rise of the die collet 5 and the amount of protrusion of the needle 4 from the thickness of the semiconductor chip
A setting unit 13 for setting in advance the thickness of the semiconductor chip 27, the moving speed of the die collet 5 and the needle 4, and an operation program; and a signal from the needle height position detection circuit 1 and the setting unit 13 and a driving power supply unit. A command signal is given to the arithmetic unit 11 and the arithmetic unit 12 so that the die collet 5 and the needle 4
And a sequence control unit 10 for controlling the operation of.

A vertical drive mechanism 8 for moving the needle 4 up and down.
The nuts meshing with the feed screw 18 are connected to the gears 19a, 19
and a pulse motor 15b that rotates through the motor b. The die collet moving mechanism 7 for moving the die collet 5 up and down is provided with a pulse motor 15
The cam 16 rotates at a constant speed, and a cam follower 17 that comes into contact with the cam 16 and is attached to the arm 14.

FIGS. 2A to 2F show a die collet and a needle in the order of operation for explaining the operation of the semiconductor chip transfer device of FIG. 1, and FIG. 3 shows the die collet in each operation of FIG. FIG. 4 is a diagram illustrating height positions of the needle and the needle. Next, the operation of the semiconductor chip transfer device will be described with reference to FIGS.

First, in the state shown in FIG. 2A, the die collet 5 and the needle 4 are stopped at the origin position at time t0. In the next state of FIG. 2B, that is, at time t1,
At the beginning of the suction operation, the die collet 5 descends and the needle 4 starts to push up. Then, at time t2, as shown in FIG.
And the needle height position detection circuit 1 described with reference to FIG.
Is closed, a detection current flows, and a detection signal is generated and transferred to the sequence control unit 10.

Next, when the sequence control unit 10 inputs the detection signal, the die collet 5 moves to the position h set in advance.
The speed is reduced from c2, and the needle 4 temporarily stops while coming into contact with the upper surface of the semiconductor chip. At the same time as the pause, the origin (hc0, hn0) and the thickness of the semiconductor chip 27 and the moving distance (hn0− hn3) is set in advance to the setting unit 1.
3 to the arithmetic unit 12 and the lower limit height hc of the collet 5
The thickness of the semiconductor chip 27 is added to the height position up to 3 and the height position of the lower surface of the collet 5 which is in contact with the upper surface of the semiconductor chip 27, and the thrust height position Δh1 of the needle 4 is obtained.

Next, the obtained distance signal at the height position Δh1 is converted into a pulse signal of a corresponding pulse count number, sent to the setting memory section of the drive power supply section 11, and
The needle 4 is raised until the number of output pulses sent to the first pulse motor 15a reaches the pulse count number in the setting memory section, and as shown in FIG. 2D, the needle 4 is broken through the conductive film 3 and the resin sheet 2. The tip is brought into contact with the lower surface of the semiconductor chip 27. And die collet 5
Is evacuated to vacuum the semiconductor chip 27. In addition, it is desirable that the pushing speed of the needle 4 that breaks through the conductive film 3 and the resin sheet 2 be reduced from the speed of the previous operation to reduce the impact given to the semiconductor chip.

Next, the die collet 5 and the needle 4 are simultaneously raised by Δh2 while holding the semiconductor chip 27, and the semiconductor chip 27 is peeled off from the resin sheet 2 in the state shown in FIG. Here, the distance Δh2 should be determined according to the adhesive force of the resin sheet, but it is not necessary to increase the distance until the semiconductor chip 27 is completely separated from the resin sheet 2. This is because excessive push-up may damage the rear surface of the semiconductor chip 27. Then, as shown in FIG. 2F, the die collet 5 is raised with the semiconductor chip 27 being sucked. Then, the die collet 5 is turned to transfer the semiconductor chip 27 to the stage of the die bonding apparatus.

In the embodiment described above, the pulse motor is used for the vertical movement drive mechanism and the die collet moving mechanism. However, a resolver for detecting the positions of the needle and the die collet, a detector such as a magnescale, and the like are provided. For example, an inexpensive DC motor can be used instead of a pulse motor.
Further, the mechanism itself can also be used with a hydraulic mechanism that is a variable speed mechanism that moves linearly, a linear motor, or the like.

[0027]

As described above, the present invention comprises a conductive film to be attached to the back of a resin sheet to which a semiconductor chip is attached, and a circuit for detecting that a needle comes into contact with the conductive film. Each time a semiconductor chip attached to the semiconductor chip is pushed up and peeled off from the resin sheet, the needle push-up is temporarily stopped, and the minimum needle push-up height enough to break through the resin film and the conductive film for bonding the semiconductor chip concerned. The position is calculated based on the thickness of the semiconductor chip with little variation, and the thrust height of the needle is suppressed to contact the resin sheet, the conductive film and the tip of the piercing needle with the lower surface of the semiconductor chip, and then the needle The semiconductor chip is lifted while holding it between the die and die collect, and peeled off from the resin sheet. , Even if there are variations in the thickness of the laminated member including a sticking was semiconductor chip on the resin sheet, an effect that occurrence of cracks pressing the impact loads at the time of contact between the needle and the semiconductor chip can be eliminated is obtained.

Further, the tool height position is adjusted based on the thickness of the semiconductor chip every time the semiconductor chip is peeled off from the resin sheet, so that the conventional method is required every time a wafer lot is changed, a tool is replaced, or a wafer of a different type is changed. This eliminates the need to perform the tool height position adjustment, which has the effect of significantly improving the operating rate of the die bonding apparatus.

[Brief description of the drawings]

FIG. 1 is a diagram showing one embodiment of a semiconductor chip transfer device of the present invention.

FIG. 2 is a view showing a die collet and a needle shown in an operation order for explaining the operation of the semiconductor chip transfer device of FIG. 1;

FIG. 3 is a view showing height positions of a die collet and a needle in each operation of FIG. 2;

FIG. 4 is a diagram showing an example of a conventional semiconductor chip transfer device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Needle height position detection circuit 2 Resin sheet 3 Conductive film 4,23 Needle 5,24 Die collet 6 Control part 7 Die collet moving mechanism 8 Vertical movement drive mechanism 9 Frame 9a Holder 10 Sequence control part 11 Drive power supply part 12 Calculation unit 13 Setting unit 14 Arm 15a, 15b Pulse motor 16 Cam 17 Cam follower 18 Feed screw 19a, 19b Gear 21 Conductivity detection plate 22 Holder 25 Die collet height position detection circuit 26 Needle height position detection circuit 27 Semiconductor chip

Claims (2)

(57) [Claims] 1. A resin sheet having a surface to which an adhesive for attaching a plurality of semiconductor chips arranged vertically and horizontally and a conductive film adhered to a back surface, and surrounding the plurality of semiconductor chips attached to the resin sheet. A frame member for grasping and holding the periphery of the resin sheet so as not to be loosened, a holding table on which the frame member is placed, and pushing up the semiconductor chip from the resin sheet by pushing up the holding table from below to a predetermined position. A peeling needle, a vertical movement driving mechanism for vertically moving the needle, a die collet moving mechanism for vertically moving a die collet for sucking and holding the protruded semiconductor chip, and the needle for the conductive film of the resin sheet. A detection circuit that detects the contact and outputs a signal, and temporarily stops the thrusting operation of the needle by inputting the signal of the detection circuit. Then, the die collet is lowered and brought into contact with the upper surface of the semiconductor chip, and then the height position obtained by adding the thickness of the semiconductor chip to the height position of the lower surface of the die collet is calculated to the obtained position. The suspended needle is pushed up to pierce the resin sheet and the conductive film to make contact with the lower surface of the semiconductor chip and the needle, and then the semiconductor chip is held in the predetermined position while being held between the needle and the die collet. A semiconductor chip transfer device, comprising: 2. The semiconductor chip transfer device according to claim 1, wherein the speed of the needle after the temporary stop is reduced from the speed before the temporary stop.