WO2015072594A1

WO2015072594A1 - Chip alignment apparatus of laser chip bonding machine

Info

Publication number: WO2015072594A1
Application number: PCT/KR2013/010326
Authority: WO
Inventors: 최지웅; 조진구; 최정수
Original assignee: (주)정원기술
Priority date: 2013-11-14
Filing date: 2013-11-14
Publication date: 2015-05-21

Abstract

The present invention relates to a chip alignment apparatus of a laser chip bonding machine, comprising a substrate stage module (10), a bonding head module (20) and an alignment vision module (30), wherein in a state in which a bonding head module (20) receives a chip in a state in which a substrate is placed on the substrate stage module (10), the alignment vision module (30) aligns the positions of the substrate and the chip by performing a vision inspection, the bonding head module (20) descends in a Z direction so as to perform bonding by means of pressing and laser irradiation, and the bonding head module (20) ascends again in the Z direction so as to be returned to the original position thereof.

Description

Chip Aligner of Laser Chip Bonding Machine

The present invention relates to a chip aligning device of a laser chip bonding machine, and more particularly, to a substrate stage module, a bonding head module, and an alignment vision module, wherein an alignment vision module performs vision inspection to align positions of a substrate and a chip. Afterwards, the bonding head module is lowered in the Z direction to bond by pressurization and laser irradiation, so that the bonding operation can be performed after precisely aligning the position of the substrate and the chip. It has a cooler for air-cooling the align vision module itself and a heat insulation plate for minimizing the temperature influence of the lower substrate so that it can be improved, and the substrate stage module has a heat sink between a heating plate and a cooling base plate for heating the substrate. To drive the substrate stage by installing a By minimizing the damage caused by the near-motor heat it will help keep the precision control operation in a stable manner.

Due to the rapid development of semiconductor technology, various electronic devices have become smaller and lighter. Flip chips, which are semiconductor chips for such small and light electronic devices, have a separate wire or ball grid array (BGA) when mounted on a substrate. It is possible to bond as it is using the electrode pattern disposed on the bottom of the chip without using.

Meanwhile, a ball grid array (BGA) chip or a flip chip has a surface where an electrode is not formed on the upper surface of a wafer, thereby inverting the chip when mounted on a substrate. A flipping process must be involved.

In addition, after the chip is inverted, the chip supplied to the bonding head through the chip transferer must be exactly aligned with the bonding position of the substrate placed in the substrate stage module, and then supplied onto the substrate to be bonded by pressing and laser irradiation. In the chip aligning apparatus, the alignment vision which has a 2-field recognition means is used normally.

On the other hand, since the bump formed on the chip must be exactly in contact with the circuit patterns formed on the substrate, the bonding process of the chip and the substrate requires very high precision. Therefore, the image of the chip and the substrate recognized as the alignment vision becomes information for causing the chip and the substrate to be aligned in position.

Also, in the case of an alignment vision having a two-field recognition means, if a misalignment occurs in the optical axis of the upper and lower recognition means, correction is required, and it is greatly affected by temperature rise due to the bonding operation. It becomes difficult, and in order to keep a precision constant, measurement time becomes long and there is an inefficient problem.

The prior art related to the present invention discloses a flip chip bonding apparatus of Patent Publication No. 10-2009-0131863, a bonding apparatus of Patent No. 0672227, and the like, in which a vision processor is fixed.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a two-view field so that the position of the chip and the substrate can be accurately aligned in a laser bonding machine for bonding a semiconductor chip onto a substrate using a laser. Using alignment vision with recognition means, it is possible to maintain the measurement accuracy stably despite temperature changes and to realize high precision mounting by using solder balls even if the mounting mark of the chip is damaged or contaminated. The present invention provides a chip aligning device for a laser chip bonding machine.

In order to achieve the above object, a preferred embodiment of the present invention comprises a substrate stage module, a bonding head module, and an alignment vision module in a bonding machine for bonding a chip picked up from a wafer onto a substrate so that the substrate is seated on the substrate stage module. After the bonding head module receives the chip in the loaded state, the alignment vision module performs vision inspection to align the positions of the substrate and the chip, and then the bonding head module descends in the Z direction to bond by pressurization and laser irradiation. After this is done, the bonding head module is raised in the Z direction to provide the chip aligning device of the laser chip bonding machine to return to the original position.

In a preferred embodiment of the present invention, the substrate stage module includes a stage moving in the X and Y directions by a linear motor, a work table mounted on the stage and fixing the substrate by a vacuum suction force, and installed below the work table. It is made by including a heating plate and a cooling base plate, the heat sink and the insulating plate is interposed between the heating plate lower portion and the cooling base plate to operate by minimizing the damage caused by the heat of the linear motor for driving the substrate stage in the X, Y direction It is designed to keep the precision stable during control.

In addition, in a preferred embodiment of the present invention, the bonding head module includes a block for up / down the bonding head, a load cell for pressing the chip secondary, a servo motor for aligning the bonding head in the θ direction, and a heat source for bonding. It comprises a laser supply for supplying.

In addition, in the preferred embodiment of the present invention, the alignment vision module includes two visions for inspecting a substrate and a chip, a cooler for cooling the vision by air cooling, and a heat insulation plate under the vision. Minimize the number and improve the inspection ability during vision inspection.

In addition, the alignment vision module is provided with an auto calibration function to prevent heat from being generated from the substrate stage module in the lower vision for inspecting the substrate, thereby causing distortion of the vision.

On the other hand, the alignment of the chip and the substrate using the existing alignment vision is made of a pattern matching algorithm, but in a specific embodiment of the present invention, the edges of the substrate and the chip are respectively detected, and each of the three edges is detected. It is programmed to extract X, Y, θ and align the relative positions of the chip and the substrate by the extracted data.

According to the embodiment of the present invention described above, when using the alignment vision having a two-field recognition means, the alignment vision module prevents the measurement accuracy from being lowered due to temperature change, thereby accurately measuring the positions of the chip and the substrate so that the center positions coincide. It can be aligned so as to provide a bonding machine that can reduce the positional shift in the bonding, and between the heating plate and the cooling base plate installed in the substrate stage module is interposed between the heat sink and the heat insulating plate X, Y The damage caused by the heat of the linear motor for driving in the direction can be minimized to enable precise operation control. Also, by implementing the alignment using the solder balls of the chip, high precision mounting is possible.

1 is a front view showing a schematic configuration of a laser chip bonding machine according to the present invention;

2 is a side view showing a schematic configuration of a laser chip bonding machine according to the present invention;

3 is a perspective view of the substrate stage module shown in FIG.

4 is a perspective view of the bonding head module shown in FIG.

5 is a perspective view of the alignment vision module shown in FIG. 1.

Hereinafter, with reference to the accompanying drawings, preferred embodiments that do not limit the present invention will be described in detail.

1 to 5 show a chip aligning device of a laser chip bonding machine according to a preferred embodiment of the present invention, the laser chip bonding device of the present embodiment includes a substrate stage module 10, a bonding head module 20, and a la The vision module 30 is composed of the in-vision module 30 and the substrate is mounted on the substrate stage module 10 and the bonding vision module 30 receives the chip and the alignment vision module 30 checks the vision of the substrate and the chip. After aligning the position of the substrate and the chip by performing the bonding, the bonding head module 20 is lowered in the Z direction and bonding is performed by laser irradiation while the chip is pressed against the substrate, and then the bonding head module 20 is again Z Direction to return to its original position.

The substrate stage module 10 serves to move and heat (preheat) the substrate to a desired position in order to bond the chips, which is provided by a linear motor (not shown) as shown in FIGS. And a stage 11 moving in the Y direction, a work table 12 mounted on the stage 11 to fix a substrate (not shown) by a vacuum suction force, and a lower portion of the work table 12. It comprises a heating plate 13 and a cooling base plate 14 to be.

In the present embodiment, a linear motor for driving the substrate stage 11 in the X and Y directions between the heating plate 13 and the cooling base plate 14 by interposing a heat sink 15 and a heat insulating plate 16 from the top. By minimizing the damage caused by heat, the precision can be maintained stably during operation control.

The heating plate 13 preheats the substrate to a temperature of about 80 ° C., and the cooling base plate 14 is always operated during operation of the equipment together with the heating plate 13 so that the heat generated from the heating plate 13 is reduced. It serves to block the fall down.

In the figure, reference numeral 17 denotes an air-gyro module for adjusting the flatness of the work table 12, reference numeral 18 denotes a box for collecting defective parts (chips), and reference numeral 19 denotes a vision calibrator.

In addition, in the present embodiment, the bonding head module 20 bonds the chip onto the substrate, which is a block 22 for up / down the bonding head 21 and a chip as shown in FIG. 4. A load cell 23 for secondary pressurization, a servo motor 24 for aligning the bonding head 21 in the θ direction, and a laser supply unit 25 for supplying a heat source for bonding.

The specific configuration and function of the block 22 and the load cell 23 are obvious to those skilled in the art in the field of laser bonding machines to which the present invention belongs, and thus detailed description thereof will be omitted.

The servo motor 24 is for aligning the bonding head 21 in the θ direction. This means that the upper edge of the alignment vision 20 (not shown) has three edges of the chip adsorbed to the bonding head 21. The bonding head 21 is moved in the [theta] direction so that it can be accurately aligned with the substrate.

The alignment vision module 30 is for inspecting and aligning a substrate and a chip, which is two vision 31 and a cooler 32 for cooling the vision 31 by air cooling as shown in FIG. 5. It consists of).

In the drawing, reference numeral 33 denotes a tool holder 33 for storing a tool, 34 denotes a sensor for detecting a tool, and 35 denotes a tool clamp.

On the other hand, reference numeral 36 is a heat insulating plate installed under the vision 31, which is to minimize the deformation of the lens due to the heat transferred from the substrate.

A process of bonding the chips after aligning the chips on the substrate using the chip alignment device of the present embodiment configured as described above will be described.

First, the substrate is placed on the work table 12 of the substrate stage module 10 and fixed by vacuum suction force, and the substrate is preheated by the heating plate 13 to bond the chip on the substrate, and is supplied from the wafer. The received chip is measured by the alignment vision module 30 before the bonding is performed while maintaining the state of being adsorbed to the bonding head 21 of the bonding head module 20 by vacuum suction force. do.

The process of measuring the position of the substrate and the chip using the alignment vision module is as follows.

First, the chip is first recognized, the edge of the solder ball is detected, and the center of the solder ball is obtained.

Two or more solder balls formed on the bottom surface of the chip are each centered to make a line, and the center point of the horizontal and vertical solder balls is connected by a line to make an intersection point.

Similarly, the secondary recognition is shifted diagonally to detect the edge of the solder ball to find the center of the solder ball.

Connect the center point of the horizontal and vertical solder balls with a line to create an imaginary square and find the horizontal, vertical, and center.

On the other hand, the substrate recognizes three of the fiducial mark (fiducial mark) to obtain the center, and then use the three points to create a virtual rectangle to obtain the horizontal, vertical, center.

After the inspection of the chip and the substrate is finished as described above to offset the offset (off-set) by the horizontal, vertical, and center of each other to drive the substrate stage module 10 and the bonding head module 20 to position the chip and the substrate After exactly matching, the bonding head finally descends to proceed with bonding.

Claims

The substrate stage module 10, the bonding head module 20, and the alignment vision module 30 are configured so that the bonding head module 20 receives the chip while the substrate is seated on the substrate stage module 10. After the alignment vision module 30 performs the vision inspection to align the positions of the substrate and the chip, the bonding head module 20 is lowered in the Z direction, and the bonding is performed again by bonding and pressing by laser irradiation. The chip aligning device of the laser chip bonding machine, characterized in that 20 is raised in the Z direction to return to the original position.
The method according to claim 1,

The substrate stage module 10 includes a stage 11 moving in the X and Y directions by a linear motor and a vacuum on the stage 11 so as to move and heat the substrate to a desired position for bonding chips. The worktable 12 which fixes the board | substrate by a suction force, and the heating plate 13 and the cooling base plate 14 which are provided in the lower part of the said worktable 12 are comprised of the laser chip bonding machine of Claim 1 characterized by the above-mentioned. Chip Aligner.
The method according to claim 2,

The heat dissipation plate 15 and the heat insulating plate 16 are installed between the heating plate 13 and the cooling base plate 14, the chip alignment device of the laser chip bonding machine.
The method according to claim 1,

The bonding head module 20 includes a block 22 for up / down the bonding head 21, a load cell 23 for pressing the chip secondary, and a servo for aligning the bonding head 21 in the? Direction. A chip arranging device for a laser chip bonding machine comprising a motor (24) and a laser supply unit (25) for supplying a heat source necessary for bonding.
The method according to claim 1,

The alignment vision module 30 includes two vision 31 for inspecting the substrate and the chip, and a cooler 32 for cooling the vision 31 by air cooling. Chip sorter.
The method according to claim 5,

Chip alignment device of the laser chip bonding machine, characterized in that the heat insulation plate 36 is installed below the vision (31).