JPH0691116B2 - Die bonding equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a die bonding apparatus.

[Prior Art] In a die bonding apparatus, a die is directly attracted and transferred from a wafer divided into a plurality of dies to a lead frame or a ceramic substrate (hereinafter, the case of a lead frame will be described). A direct die bonding device for bonding and a buffer part for temporarily mounting the dies between the die pickup position and the die bonding position are provided, and the dies are picked up and transferred one by one by a transfer device from the wafer and mounted on the buffer part. There is an indirect die bonding apparatus in which the die of the buffer section is sucked and transferred by a bonding apparatus and bonded to the lead frame.

In the former direct die bonding machine, the suction part of the bonding head of the die bonding machine is heated (the lead frame is heated to a certain temperature and bonded, which heats the bonding head). When adsorbing, the heat of the bonding head is transferred to the adhesive sheet on which the wafer is attached, and the adhesive sheet loosens or melts.
As a result, the alignment of the dies on the pressure-sensitive adhesive sheet is disturbed, and there is a problem that die pick-up becomes impossible or bonding failure occurs. Therefore, recently, the latter indirect die bonding apparatus is mainly used.

Conventionally, as such an indirect die bonding apparatus, for example, one shown in Japanese Patent Publication No. 57-44014 is known.

In this structure, an adhesive tape that is intermittently moved is provided between a die pick-up position from the wafer and a die bonding position, and the die is sucked from the wafer one by one by a transfer device and attached to the adhesive tape. The die attached to the above is sucked and transferred by the suction portion of the bonding head and bonded to the lead frame.

[Problems to be Solved by the Invention] In the above conventional example, since the die is attached to the adhesive tape, the die may be attached to the adhesive tape from the transfer device only after the die is adsorbed by the bonding head from the adhesive tape. Can not.

By the way, only about 30% of wafers have good dies. Therefore, when good dies are continuous, there is no balance between the operation cycle of the transfer device and the operation cycle of the bonding head, but when defective dies are continuous, until the good dies are detected. There is a problem that the time becomes longer, the balance between the operation cycles of both is broken, the operation of the bonding head is temporarily stopped, and the productivity is reduced. Further, since the adhesive tape cannot be reused and is a consumable item, there is a problem that the cost of the product is increased accordingly.

An object of the present invention is to provide a die bonding apparatus capable of improving productivity and reducing cost.

[Means for Solving Problems] A problem of the above-mentioned conventional technique is that it has a wafer table mounted with a wafer divided into a plurality of dies and driven in two orthogonal directions, and an inclined portion and a flat portion. At the same time, a guide groove is formed along the inclined portion and the flat portion, and a buffer in which a die positioning hole is formed on the lower end side of the inclined portion of the flat portion, and the inclined portion near the flat portion are provided. Die feeding means for holding the tip die located in the guide groove and dropping only one tip die into the die positioning hole when there is no die in the die positioning hole, and the buffer from the die pickup position of the wafer table. The transfer means for transferring the die to the guide groove of the inclined portion of the, the lead frame transfer line for intermittently transferring the lead frame and the like, and the die positioned in the die positioning hole of the buffer This is solved by a bonding means for transferring the lead frame to the bonding position of the lead frame transfer line and bonding it to a lead frame or the like.

[Operation] The non-defective die that is divided from the wafer is supplied to the guide groove of the inclined portion of the buffer by the transfer means. The die supplied to the guide groove of the inclined portion is dropped into the die positioning hole by the die supply means when there is no die in the die positioning hole of the buffer. The die in the die positioning hole is transferred to the bonding position by the bonding means and bonded to the lead frame or the like.

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. The wafer 2 divided into a plurality of dies 1 is attached to an adhesive tape (not shown). Wafer 2 is
The wafer 1 is mounted on a wafer table 3 which is movable in directions A and B orthogonal to each other by a driving means (not shown), and the dies 1 aligned by the wafer table 3 are sequentially fed and positioned to a die pickup position 4.

A buffer 10 is provided near the wafer table 3. The buffer (10) has an inclined part (11) and a flat part (12) extending horizontally from the lower end of the inclined part (11).
A guide groove along 12 that is slightly larger than the width of the die 1
13 are continuously formed. In addition, the guide groove of the inclined part 11
Two suction holes 14 and 15 are formed in the vicinity of the flat portion 12 on the flat portion 13, and the suction holes 14 and 15 are connected to a vacuum pump via a solenoid valve (not shown). A die positioning hole 16 slightly larger than the size of the die 1 is formed in the guide groove 13 of the flat portion 12 near the lower end of the inclined portion 11.

The die 1 at the die pickup position 4 is transferred to the guide groove 13 of the inclined portion 11 of the buffer 10 by the transfer arm 20 which is moved up and down and rotated in the directions of arrows C and D by a driving means (not shown). The transfer arm 20 has a transfer head 21 that holds the die 1 by vacuum suction.

On the side of the buffer 10 opposite to the wafer table 3, a lead frame transfer line 26 for intermittently sending the lead frame 25 in the direction of arrow E by a driving means (not shown) is provided.

The die 1 in the die positioning hole 16 of the buffer 10 is transferred to a bonding position 28 of the lead frame transfer line 26 by a bonding arm 27 which is vertically moved and reciprocated in the directions of arrows F and G by a driving means (not shown). The bonding arm 27 has a bonding head 29 for vacuum-sucking the die 1 at the tip thereof.

Next, the operation will be described. When the non-defective die 1 detected by the die pass / fail detection means (not shown) is positioned at the die pickup position 4, the transfer head 21 descends from above the die pickup position 4 to suck the die 1 in vacuum,
Rise again. Then, the transfer arm 20 rotates in the direction of arrow C and is positioned above the guide groove 13 of the inclined portion 11 of the buffer 10. After that, the transfer head 21 descends, the vacuum is broken, the die 1 is placed on the guide groove 13 of the inclined portion 11 of the buffer 10, and the die 1 is raised again and rotated in the direction of the arrow D to move above the die pickup position 4. Located in. During this time, the wafer table 3 is pitch-fed in the direction of arrow A or arrow B, and a new non-defective die 1 is positioned at the die pickup position 4. Thereafter, the above operation is repeated, and the dies 1 on the wafer table 3 are sequentially transferred to the buffer 10. This operation continues until die 1 into buffer 10 is full.
When the buffer 10 is full, the operation is stopped until the buffer 10 becomes the accepting state.

When the die 1 supplied to the buffer 10 as described above has the die 1 in the die positioning hole 16, the next second die 1 and the next third die 1 are suction holes 14, 15. It is adsorbed by and is held at that position. The fourth die 1 and subsequent die 1 are sequentially arranged following the third die 1. When the die positioning hole 16 does not have the die 1, the suction hole 14 is turned off, and the die 1 held in the suction hole 14 naturally falls along the inclined portion 11 and enters the die positioning hole 16. Next, the suction holes 14 are turned on, and the suction holes 15 are turned off. As a result, the die 1 held in the suction holes 15 will be moved to the suction holes 14
Held in. Then, the suction hole 15 is turned on, and the next die 1 is held in the suction hole 15. In this way, when there is no die 1 in the die positioning hole 16, they are sequentially fed one by one.

On the other hand, when the die positioning hole 16 has the die 1, the bonding arm 27 advances in the direction of the arrow F to move the die positioning hole.
It is located above 16 and descends, and the bonding head 29 adsorbs the die 1. Next, the bonding arm 27 moves up and moves in the direction of arrow G to transfer the die 1 above the bonding position 28. Then, the bonding arm 27 descends to bond the die 1 to the lead frame 25. After bonding, the bonding arm 27 ascends and moves in the direction of arrow F, and the above operation is repeated. When the bonding arm 27 advances in the direction of arrow F, the lead frame carrying line 26 carries out the operation of carrying the lead frame 25 by one pitch.

In this way, a plurality of dies 1 can be stored in the buffer 10, and when the dies 1 are removed from the die positioning holes 16 of the buffer 10, the sloping portions 11 immediately supply the dies 1 to the die positioning holes 16. can do. Therefore, the die 1 of the wafer 2 is continuously defective and even if it takes time to detect whether the die 1 is good or bad, the bonding arm 27 can continue its operation without stopping. In addition, since no consumable item like the conventional one is used, the cost does not increase.

In the above embodiment, the suction holes 14 and 15 were used as the die supply means for supplying the dies 1 accumulated in the inclined portion 11 to the die positioning holes 16 one by one, but two claws are alternately taken in and out. It may be a means to do. Further, when the die 1 of the inclined portion 11 is dropped into the die positioning hole 16, not only the die 1 naturally falls but also vibration is applied to the buffer 10 so that the die 1 can be dropped more smoothly. Further, in the case where the positioning accuracy of the die 1 is required, conventionally known positioning means, for example, means for positioning the die by two or four claws may be provided in the die positioning hole 16.

[Effects of the Invention] As is clear from the above description, according to the present invention, productivity can be improved and cost can be reduced.

[Brief description of drawings]

FIG. 1 is a schematic configuration plan view showing an embodiment of the present invention, and FIG.
The figure is a cross-sectional view of the buffer of FIG. 1: Die, 2: Wafer, 3: Wafer table, 4: Die pickup position, 10: Buffer, 11: Inclined part, 12: Flat part, 13: Guide groove, 14, 15: Suction hole, 16: Die positioning hole , 20: Transfer arm, 25: Lead frame, 26: Lead frame transfer line, 27: Bonding arm, 28: Bonding position.

Claims (1)

[Claims] 1. A wafer table, into which a plurality of dies are divided, is mounted and is driven in two directions orthogonal to each other, a sloped portion and a flat portion, and a guide groove is formed along the sloped portion and the flat portion. And a buffer in which a die positioning hole is formed on the lower end side of the inclined portion of the flat portion and a die positioning hole which is provided in the inclined portion near the flat portion and holds the tip die located in the guide groove of the inclined portion. When there is no die, only one die at the tip is dropped into the die positioning hole, transfer means for transferring the die from the die pickup position of the wafer table to the guide groove of the inclined portion of the buffer, and the lead. Bonding of the lead frame transfer line for intermittently transferring the frame and the die positioned in the die positioning hole of the buffer to the lead frame transfer line Die bonding apparatus and transported to location comprising a bonding means for bonding the lead frame or the like.