JP2760547B2 - Chip bonding equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial application field) The present invention relates to a chip bonding apparatus for automatically mounting a semiconductor chip on a circuit board.

(Prior Art) In a liquid crystal display panel, a thin electronic product, or the like, a method of directly mounting a semiconductor chip on a circuit board is adopted in order to increase the density of the circuit board. Further, in order to reduce the mounting area of the semiconductor chip, a method of directly mounting the semiconductor chip in a face-down state on a circuit board using a projecting electrode provided on an element surface of the semiconductor chip is implemented.

This face-down mounting method uses a protruding electrode of a semiconductor chip and a wiring pattern on a circuit board (pitch: about 150 μm)
Must be aligned with high accuracy of about ± 10 μm. For this reason, conventionally, an operator has used a microscope or a magnifying monitor to align the wiring pattern of the circuit board and the protruding electrodes of the semiconductor chip, or the flip-chip bonding method has been used to automatically align the circuit board and the semiconductor chip. After that, a method of heating and connecting through a reflow furnace has been adopted.

(Problems to be Solved by the Invention) However, the operation of aligning the circuit board and the semiconductor chip using a microscope by an operator is inefficient and is not suitable for mass production. In addition, the method of heating and connecting through a reflow furnace after aligning a circuit board and a semiconductor chip as a flip chip bonding method cannot cope with a case where a wiring pattern becomes narrow, and has a disadvantage that a connection material is limited.

Further, since no pressure is applied when the semiconductor chip is connected to the circuit board, it is difficult to connect all the minute projection electrodes.

The present invention has been made in view of the above circumstances. It is an object of the present invention to provide a chip bonding apparatus that can perform high-precision alignment and securely connect a chip when directly mounting the chip on a circuit board. To provide.

[Configuration of the invention]

(Means and Actions for Solving the Problems) In order to achieve the above object, the present invention provides a board mounting stage that holds a circuit board on which a chip is mounted and is movable in the XY direction in a horizontal plane. A bonding tool having a heating means for holding the chip in a face-down state and heating the chip while rotating the bonding tool about an axis perpendicular to the substrate mounting stage and in a vertical direction, A bonding head having means for detecting a load applied to the chip, a chip supply mechanism for sucking and holding the chip from a chip supply unit, inverting the chip, and supplying the chip face down to a suction unit of a bonding tool, and the substrate mounting stage Is provided between the tool and the bonding tool so that it can move back and forth. A two-view position detecting optical system for detecting the position of the chip and the position of the circuit board, and correcting the movement of the substrate mounting stage in the XY direction by a detection signal from the two-view position detecting optical system, and a bonding tool. And a controller for correcting the rotation about the vertical axis.

Then, the chip is sucked from the chip supply unit by the chip supply mechanism, the chip is supplied to the bonding tool in a face-down state, and the chip is suctioned. Then, the positions of the circuit board and the chip are detected by the two-view position detection optical system. The bonding tool is lowered to bond the chip to the circuit board.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a gantry, on which a substrate mounting stage 2 is provided. The substrate mounting stage 2 is movable in the X direction and the Y direction in a horizontal plane, and has a holding portion 4 for holding a circuit board 3 as shown in FIG. A heater 5 is provided. Further, a gate-shaped frame 6 is provided on the gantry 1, and a bonding head 7 is attached to the frame 6 so as to face the substrate mounting stage 2. A bonding tool 8 is supported on the bonding head 7 vertically to the substrate mounting stage 2. The bonding tool 8 is rotatable about its axis and is movable in the vertical direction. A motor 9 for rotating the bonding tool 8 and a bonding tool 8
There is provided an air cylinder 10 for roughly feeding in the vertical direction and a servomotor 11 for finely feeding the cylinder. Further, a suction portion 13 for vacuum-suctioning a chip 12 such as an IC chip is provided at a tip portion of the bonding tool 8, and
A heater 14 is provided for heating the chip 12 adsorbed by the adsorbing section 13. Further, a parallelism adjusting mechanism 15 and a load detector 16 for directly reading a load applied to the chip 12 are provided above the bonding tool 8.

On the other hand, a tray 17 as a chip supply unit is provided on the gantry 1 located adjacent to the substrate mounting stage 2. A large number of chips 12 are stored in the tray 17 in an aligned state, and an intermediate positioning device 18 is provided adjacent to the tray 17. This intermediate positioning device 18
As shown in FIG. 3, a chip mounting table 19 for holding the chip 12 lightly by negative pressure, and a chip mounting table 19
And a pusher lever 20 which pushes the chip 12 from four directions to perform centering. Then, the chips 12 stored in the tray 17 are picked up by a chip supply mechanism 21 described later, and
The chip 12 is mounted on the chip 18 to position the chip 12 in the XY direction.

The chip supply mechanism 21 will be described. Reference numeral 22 denotes a guide mechanism, and the guide mechanism 22 is provided with a movable block 23 that is movable in the front-rear direction and the vertical direction.
A supply arm 24 is supported by the movable block 23 so as to be rotatable by 90 ° in a horizontal plane and to be vertically inverted by 180 °. As shown in FIG. 4, the supply arm 24 has a distal end portion bent in an L-shape, and a suction portion 25 for vacuum-suctioning the chip 12 is provided on the distal end surface. Then, by turning and vertically moving the supply arm 24, the chips 12 in the tray 17 are suctioned by the suction section 25 and picked up, transferred to the intermediate positioning device 18, and the chips 12 positioned by the intermediate positioning device 18 are again moved. The chip 12 is sucked and turned over, that is, the chip 12 is supplied face down to the bonding tool 8.

A visual table 26 composed of an XY table is provided on the gantry 1 located behind the substrate mounting stage 2. On this visual table 26, a two-view position detecting optical system 27 is mounted. This two visual field position detection optical system
Reference numeral 27 denotes a prism 29 at the tip of a lens barrel 28 as shown in FIG.
Is provided, and the prism head 30 can move forward and backward between the substrate mounting stage 2 and the bonding tool 8 by moving the visual table 26 in the front-rear direction. Further, the prism head 30
A chip-side shutter 31 is provided on the upper surface and a substrate-side shutter 32 is provided on the lower surface, so that the position of the circuit board 3 and the position of the chip 12 can be captured as image signals. Then, each image of the circuit board 3 and the chip 12 is fetched, and the control unit 33 calculates the relative displacement between the two based on the image signals,
A movement correction signal is input to the bonding head 7.

Reference numeral 34 denotes a resin dispenser, which has a syringe 36 at the tip of the turning arm 35. Then, in a process before and after mounting the chip 12 on the circuit board 3, a predetermined amount of resin is applied to the mounting position, so that the chip 12 can be reliably held.

Next, the operation of the chip bonding apparatus configured as described above will be described.

When the circuit board 3 is held by the holding section 4 of the substrate mounting stage 2, the circuit board 3 is heated to a predetermined temperature by the heater 5. On the other hand, only one chip 12 stored in the tray 17 is picked up by the supply arm 24 of the chip supply mechanism 21. That is, when the supply arm 24 turns and the suction unit 25 faces the chip 12 of the tray 17, the supply arm 24 descends and the suction unit 25 suction-holds the chip 12. Supply arm 24
When the chip 12 sucks the chip 12, the supply arm 24 linearly moves backward, and places the sucked chip 12 on the chip mounting table 19 of the intermediate positioning device 18. At this time, since the chip mounting table 19 is suctioned by vacuum, the chip 12 is lightly held by the negative pressure. In this state, the pusher lever is pushed from four directions.
As 20 moves forward, the tip 12 is centered.

When the centering of the chip 12 is completed, the supply arm 24
The chip 12 is sucked again by the suction unit 25, and the supply arm 24 turns 90 ° and turns upside down by 180 °. Therefore, the chip 12 sucked by the suction portion 25 is supplied to the lower side of the bonding tool 8 in a face-down state, that is, with the protruding electrodes facing downward. Bonding tool 8
A suction portion 13 is provided at the lower end of the supply arm 24, and the chip 12 sucked by the suction portion 25 of the supply arm 24 is suctioned.
Is attracted to the attracting portion 13 of the bonding tool 8.

As described above, when the circuit board 3 and the chip 12 are separated and opposed to each other, the two-view position detecting optical system 27 operates to detect the relative position between the circuit board 3 and the chip 12. That is, first, the visual table 26 is operated, the lens barrel 28 advances, and the prism head
30 intervenes between the circuit board 3 and the chip 12. Next,
The visual table 26 moves in the X and Y directions so that the circuit board 3 and the chip 12 enter a predetermined field of view. In this state, the chip-side shutter 31 and the substrate-side shutter 32 alternately open and close, and the control unit 33 captures images of the circuit board 3 and the chip 12, and calculates a relative displacement amount between the two based on the image signal. . Then, based on the calculation result of the displacement amount, the control unit 33
When the movement correction signal is input to the substrate mounting stage 2 and the bonding head 7 from the
The bonding head 7 corrects the bonding tool 8 in the θ direction to perform relative alignment between the circuit board 3 and the chip 12. When the alignment is completed, the two-field-of-view position detecting optical system 27 is retracted by the visual table 26 and retracted from the bonding tool 8.

Next, the bonding tool 8 is coarsely fed downward by the air cylinder 10 provided on the bonding head 7 and then finely fed by the servomotor 11. At this time, the load applied to the chip 12 by the load detector 16 is measured. The servo motor 10 is controlled. And chips
The position where the load applied to 12 reaches the set load, that is, the tip
The servomotor 10 is stopped when a predetermined load is applied by joining 12 to the mounting position of the circuit board 3. Next, the heater 12 of the bonding tool 8 is energized to heat the chip 12 and bond the chip 12 to the circuit board 3.

When the bonding of the chip 12 is completed, the bonding tool 8 and the connection part are cooled, the vacuum suction of the suction part 13 is released, and the bonding tool 8 rises.

During bonding, the supply arm 24 of the chip supply mechanism 21 returns, picks up the chip 12 to be bonded next from the tray 17, and performs centering in the intermediate positioning device 18. Supply can be done quickly.

〔The invention's effect〕

As described above, according to the present invention, when mounting a chip on a circuit board mounted on a substrate mounting stage, the chip is supplied from the chip supply unit to the bonding tool in a face-down state, and the circuit board and the chip are mounted. Is detected by the two-field-of-view position detecting optical system and the position is corrected, so that even a fine-pitch wiring can be positioned and mounted with high precision with the electrodes of the chip. Further, by pressing the chip and controlling the load while directly detecting the load applied to the chip, there is an effect that a reliable connection can be made.

[Brief description of the drawings]

1 shows an embodiment of the present invention. FIG. 1 is an overall perspective view of a chip bonding apparatus, FIG. 2 is a perspective view of a circuit board and a chip, and FIG. 3 is a schematic configuration diagram of an intermediate positioning apparatus. , FIG. 4 is a front view of the chip supply mechanism, and FIG.
It is a front view of a visual field position detection optical system. 2 ... board mounting stage, 3 ... circuit board, 7 ... bonding head, 8 ... bonding tool, 12 ... chips, 17 ... tray (chip supply unit), 27 ... 2 visual field position detection optical system, 33 ... Control unit.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-62-24635 (JP, A) JP-A-57-147245 (JP, A) JP-A-59-111339 (JP, A) JP-A-57-147339 206037 (JP, A) (58) Field surveyed (Int. Cl. ⁶ , DB name) H01L 21/60 311

Claims (1)

(57) [Claims] 1. A substrate mounting stage which holds a circuit board on which a chip is mounted and is movable in the XY direction in a horizontal plane, and a heating means for holding the chip by sucking it face down and heating the chip. A bonding tool comprising: a bonding tool having means for detecting a load applied to the chip at the time of bonding while rotating and moving the bonding tool about an axis perpendicular to the substrate mounting stage in a vertical direction. A chip supply mechanism that suction-holds the chip from the chip supply unit, inverts the chip, and supplies the chip to the suction unit of the bonding tool in a face-down state, and is provided movably between the substrate mounting stage and the bonding tool. Position of the chip adsorbed on a bonding tool and the circuit board A two-field position detection optical system for detecting a position, and the movement of the substrate mounting stage in the XY direction is corrected by the detection signal from the two-field position detection optical system, and the bonding tool is rotationally corrected about its vertical axis. A chip bonding apparatus comprising: a control unit.