KR20230073925A - Chip bonding device and a method for correcting posture of the bonding head - Google Patents

Abstract

A chip bonding device comprises: a bonding unit including a bonding stage that supports a transparent circuit board on which wires connected to bumps of a driving package are formed and a bonding head that presses the bumps to bond the bumps to the wires; a vision unit that generates a bump image by photographing the bumps bonded to the wires at a lower portion of the transparent circuit board; a data storage module that stores comparative contrast ratio data of the bumps spaced apart from each other, bonding head tilt data and codes corresponding to the comparative contrast ratio data when the driving package and the transparent circuit board are bonded to each other in a state in which the bonding head is not parallel to the upper surface of the driving package; a contrast ratio calculation unit that calculates actually measured contrast ratio data of the bumps included in the bump image; a correction data calculation unit that selects the comparative contrast ratio data and the tilt data corresponding to the actually measured contrast ratio data and calculates correction data for correcting the tilt of the bonding head based on the selected tilt data; and a posture correction unit that adjusts the tilt of the bonding head based on the correction data. The posture of the bonding head can be corrected corresponding to the upper surface of the driving package.

Description

Chip bonding device and a method for correcting posture of the bonding head

The present invention relates to a chip bonding device and a method for correcting a posture of a bonding head.

In general, a display device includes a display panel on which an image is displayed and a drive driver IC mounted on the display panel to apply a driving signal to the display panel.

A driving driver IC used in a display device includes a driving package having a plurality of bumps and a flexible circuit board including wires bonded to the bumps of the driving package.

The wiring of the flexible circuit board electrically connects the bump of the driving drive IC and the signal line of the display panel.

In general, in order to electrically connect the bumps of the driving drive IC to the wiring of the flexible circuit board, place the driving drive IC and the flexible circuit board on a bonding stage and press the bumps of the driving drive IC with a heated bonding head to Connect the wires electrically.

The bonding head that presses the driving drive IC must be placed parallel to the top surface of the driving package or maintain a horizontal posture with respect to the top surface of the driving package.

When the bonding head is not parallel to the top surface of the drive package and the bonding head is disposed inclined with respect to the top surface of the drive package, a bonding pressure higher than a predetermined bonding pressure is applied to bumps disposed on one side of the drive package, and the drive package A bonding pressure lower than a predetermined bonding pressure may be applied to the bumps disposed on the other side of the bumps, and thus bonding failure between the driving package and the flexible circuit board may occur.

Republic of Korea Patent Publication No. 10-2018-0040349, a parallelism correction device between a bonding head and a stage and a chip bonder including the same (published on April 20, 2018), parallelism (or inclination) between a stage on which a package substrate is placed and a bonding head ) during the bonding process, and the sensing unit includes a load sensor, a displacement sensor, a strain sensor, a cylindrical encoder or a plate-type encoder that detects an inclined angle of the bonding head, and a load cell. .

However, since the correction device and the chip bonder only detect and correct the parallelism of the bonding head through a sensing unit mounted on the bonding head, it is difficult to cope with problems that occur after the bonding head actually pressurizes the driving package, and the bonding head It has a technical limitation in that it takes a relatively long time to detect and correct parallelism.

Patent Publication 10-2018-0040349, parallelism correction device between bonding head and stage and chip bonder including the same (published on April 20, 2018)

The present invention provides a chip bonding device capable of correcting the posture of a bonding head corresponding to the top surface of a drive package by determining the inclination of the top surface of the bonding head and the drive package using the contrast ratio of bonded bumps and a method for correcting the posture of the bonding head. to provide.

As an embodiment, a chip bonding apparatus includes a bonding unit including a bonding stage supporting a transparent circuit board on which wires connected to bumps of a driving package are formed, and a bonding head pressing the bumps to bond the bumps to the wires. ; a vision unit generating a bump image by photographing the bumps bonded to the wiring at the bottom of the transparent circuit board; When the driving package and the transparent circuit board are bonded to each other in a state where the bonding head is not parallel to the top surface of the driving package, comparative contrast ratio data of the bumps spaced apart from each other, and the bonding head corresponding to the comparative contrast ratio data a data storage module in which gradient data and codes are stored; a contrast ratio calculating unit which calculates actual contrast ratio data of the bumps included in the bump image; a correction data calculating unit that selects the comparative contrast ratio data and the tilt data corresponding to the actually measured contrast ratio data, and calculates correction data for correcting the tilt of the bonding head based on the selected tilt data; and a posture correction unit adjusting the tilt of the bonding head based on the correction data.

The contrast ratio calculation unit of the chip bonding device calculates the actual contrast ratio data using a first bump group that is a part of the bumps included in the bump image and a second bump group spaced apart from the first bump group by a predetermined distance.

The first bump group of the chip bonding device is disposed on one outer edge of the bumps, and the second bump group is disposed on the other outer edge opposite to the one outer edge among the bumps.

A posture correction method of a bonding head may include comparison contrast ratio data of bumps of a driving package and the bonding corresponding to the comparative contrast ratio data when the driving package and wires are mutually bonded in a state in which the bonding head is not parallel to the top surface of the driving package. storing head tilt data and code respectively; bonding the bumps and the wires by pressing the bumps and the wires of the driving package using the bonding head; generating a bump image by photographing the bumps bonded to the wiring at a lower portion of the wiring; calculating actual contrast ratio data of the bumps included in the bump image; selecting the comparative contrast ratio data and the gradient data corresponding to the actually measured contrast ratio data, respectively; Calculating correction data for correcting the tilt of the bonding head based on the selected tilt data; and adjusting the posture of the bonding head based on the calculated correction data.

In the generating of the bump image, the driving package and the wiring are bonded n times (n is a natural number greater than 1) by the bonding head, and then the bump image is generated.

The chip bonding apparatus and method for correcting the posture of the bonding head according to the present invention can correct the posture of the bonding head corresponding to the upper surface of the driving package by determining the inclination of the bonding head and the upper surface of the driving package using the contrast ratio of the bonded bumps. have an effect

1 is a rear view of a driving package and a transparent circuit board according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view taken along line II′ of FIG. 1 .
3 is a block diagram showing a chip bonding device according to an embodiment of the present invention.
4 is a table showing data stored in a data storage module according to an embodiment of the present invention.
5 is a table showing actually measured contrast ratio data, gradient data, and correction data of bumps bonded by a bonding head.
6 is a flowchart illustrating a method for correcting a posture of a bonding head according to an embodiment of the present invention.

The present invention described below may apply various transformations and may have various embodiments, and specific embodiments are illustrated in the drawings and described in detail in the detailed description.

However, it should be understood that this is not intended to limit the present invention to specific embodiments, and includes all transformations, equivalents, and substitutes included in the spirit and scope of the present invention. In describing the present invention, if it is determined that a detailed description of related known technologies may obscure the gist of the present invention, the detailed description will be omitted.

Terms used in this patent are only used to describe specific embodiments and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this patent, terms such as "include" or "have" are intended to designate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, but one or more other features It should be understood that the presence or addition of numbers, steps, operations, components, parts, or combinations thereof is not precluded.

In addition, terms such as first and second may be used to classify and describe various components, but the components should not be limited by the terms. These terms are only used for the purpose of distinguishing one component from another.

In addition, when at least two different embodiments are described in this patent, all or part of the components of each embodiment can be merged and mixed with each other, even if there is no specific description, within the scope of not departing from the technical spirit of the present invention. .

1 is a rear view of a driving package and a transparent circuit board according to an embodiment of the present invention. FIG. 2 is a cross-sectional view taken along the line II' of FIG. 1 . 3 is a block diagram showing a chip bonding device according to an embodiment of the present invention.

1 to 3, a driving circuit (not shown) is formed inside the driving package 110 bonded to each other by the chip bonding device 800, and the driving circuit and electrical electrical connection are formed outside the driving package 110. A bump 115, which is a terminal connected to , is formed.

A plurality of bumps 115 may be arranged in a matrix form on the lower surface of the driving package 110 .

In one embodiment of the present invention, as shown in FIG. 2 , the bumps 115 disposed on one end of the lower surface of the driving package 110 are defined as a first bump group 116, and the The bumps 115 disposed at the other end spaced apart from the first bump group 116 by a predetermined distance on the lower surface are defined as the second bump group 117 .

Although, in one embodiment of the present invention, the first bump group 116 is disposed on one side of the bumps 115, and the second bump group 117 is on the other side opposite to one side of the bumps 115. Although the arrangement is illustrated and described, otherwise, the first bump group 116 and the second bump group 117 may include bumps 115 spaced at regular intervals regardless of positions.

Each bump 115 of the driving package 110 is electrically connected to the wiring 125 formed on the transparent circuit board 120 and physically/electrically bonded.

The bump 115 of the driving package 110 and the wiring 125 of the transparent circuit board 120 are mutually bonded by the chip bonding device 800 shown in FIG. 3 .

Referring back to FIG. 3 , the chip bonding device 800 according to an embodiment of the present invention includes a bonding unit 150, a vision unit 200, a data storage module 300, a contrast ratio calculation unit 400, and correction data. A calculation unit 500 and a posture correcting unit 600 are included.

The bonding unit 150 includes a bonding stage 160 and a bonding head 170 .

The bonding stage 160 supports the transparent circuit board 120 on which the driving package 110 shown in FIGS. 1 and 2 is mounted.

The bonding head 170 is disposed above the bonding stage 160, and the bonding head 170 presses the driving package 110 disposed on the wiring of the transparent circuit board 120 disposed on the bonding stage 160 to The bumps of the driving package 110 are bonded to the wires of the transparent circuit board 120 .

In one embodiment of the present invention, the bonding head 170 may have various mechanisms capable of correcting an inclination of the upper surface of the drive package 110 .

The bonding head 170 includes a posture correction unit 600 that controls the posture of the bonding head 170 so that the lower surface of the bonding head 170 is parallel to the upper surface of the drive package 110 or the wiring of the transparent circuit board 120. ) is installed.

The posture correcting unit 600 uses a motor (not shown) so that the lower surface of the bonding head 170 and the upper surface of the driving package 110, the lower surface of the bonding head 170 and the wiring of the transparent circuit board 120 are parallel to each other. The posture of the bonding head 170 is adjusted so as to

In one embodiment of the present invention, the posture correction unit 600 precisely controls the posture of the bonding head 170 based on the correction data calculated by the correction data calculation unit 500 to be described later.

The vision unit 200 photographs the bump 115 after the bump of the driving package 110 is bonded to the wiring of the transparent circuit board 120 .

The vision unit 200 includes a digital camera, and generates the bump image 210 by photographing light reflected from the bump 115 emitted to the outside of the bonding stage 160 .

In one embodiment of the present invention, the vision unit 200 is disposed under the transparent circuit board 120, and the vision unit 200 takes pictures of the transparent circuit board 120, thereby passing through the transparent circuit board 120. Light reflected from the first bump group 116 and the second bump group 117 of the bump 115 is photographed.

For example, the vision unit 200 generates a bump image 210 by photographing the bump 115 of the driving package 110 after being aligned with the central portion of the driving package 110 . In one embodiment of the present invention, the alignment of the vision unit 200 in the central portion of the driving package 100 includes the first bump group 116 and the second bump group included in the bump image 210 spaced apart from each other ( 117) to minimize the deviation of the reflected light.

4 is a table showing data stored in a data storage module according to an embodiment of the present invention.

Referring to FIG. 4 , when the driving package 110 and the transparent circuit board 120 are bonded to each other in a state in which the bonding head 170 is not parallel to the upper surface of the driving package 110 in the data storage module 300 . Sample contrast ratio data 310 of mutually spaced apart bumps, inclination data 320 of the bonding head 170 corresponding to the sample contrast ratio data 310 , and a corresponding code 330 are stored.

For example, in FIG. 4 , when the bonding head 170 is tilted a° (where a is a range) with respect to the upper surface of the driving package 110, the mutual spacing included in the bump image captured by the vision unit 200 The comparative contrast ratio of the bumps was A:1 (provided that A is a natural number and range).

In one embodiment of the present invention, a° may be an angular range, and the comparative contrast ratio may also be a range.

Meanwhile, when the bonding head 170 is tilted b° (but, b>a, range) with respect to the top surface of the driving package 110, mutually spaced bumps included in the bump image captured by the vision unit 200 The comparative contrast ratio was B:1 (provided that B>A, B is a range).

When the bonding head 170 is tilted c° with respect to the upper surface of the driving package 110 (where c>b, c is the range), mutually spaced bumps included in the bump image captured by the vision unit 200 The comparative contrast ratio was C:1 (provided that C>B, and C is a range).

In addition, when the bonding head 170 is tilted n° with respect to the top surface of the driving package 110 (where n>c, where n is the range), the contrast ratio of bumps included in the bump image captured by the vision unit 200 is N: 1 (provided that N>C, N is a range).

In one embodiment of the present invention, the range of each angle at which the bonding head 170 is tilted with respect to the upper surface of the driving package 110 is a continuous range, and each range of the comparative contrast ratio is also a continuous range.

In addition, as the inclination of the upper surfaces of the bonding head 170 and the driving package 110 increases, the contrast ratio of spaced apart bumps included in the bump image corresponds to the inclination of the upper surfaces of the bonding head 170 and the driving package 110. is increased by

5 is a table showing actually measured contrast ratio data, gradient data, and correction data of bumps bonded by a bonding head.

Referring back to FIGS. 3 and 5 , the contrast ratio calculation unit 400 takes pictures of the bumps of the drive package 110 bonded by the bonding head 170 and the wiring of the transparent circuit board, which are generated by the vision unit 200. The bump image is image-processed to calculate actually measured contrast ratio data 410 of the first bump group 116 and the second bump group 117 included in the bump image.

As shown in FIG. 5 , the measured contrast ratio data is C:1, and the measured contrast ratio data 410 is temporarily stored in, for example, the data storage module 300 .

The correction data calculating unit 500 selects the comparison contrast ratio 310 corresponding to the actually measured contrast ratio data 410 in the data storage module 300, and as the comparison contrast ratio 310 is selected, the comparison contrast ratio corresponding to the comparison contrast ratio 310 is selected. Gradient data 320 and code 330 are selected.

For example, when the actually measured contrast ratio data 410 is C:1, the correction data calculation unit 500 selects C:1 from the comparison contrast ratio 310, and selects C:1 from the comparison contrast ratio 310. Select code CODE3 and gradient data c°.

That is, when the actually measured contrast ratio data 410 is C:1, it means that the bonding head 170 is tilted from the top surface of the driving package 110 by c°.

When the tilt of the bonding head 170 is confirmed, the correction data calculation unit 500 calculates correction data 510 for correcting the tilt of the bonding head 170 .

In one embodiment of the present invention, the correction data calculation unit 500 calculates the correction data 510 so that the bonding head 170 is parallel to the upper surface of the driving package 110 using the inclination of the bonding head 170. Alternatively, as shown in FIG. 5 , correction data corresponding to the tilt data 320 may be calculated in advance and the data may be stored in the form of a lookup table, and then correction data corresponding to the tilt data may be selected and used.

For example, in one embodiment of the present invention, when the measured contrast ratio data 410 is C:1, the tilt data is c°, the corresponding code is CODE3, and the correction data 510 corresponding to the tilt data c° is is CD3.

When the correction data 510 is calculated by the correction data calculation unit 500, the correction data 510 calculated by the correction data calculation unit 500 is transmitted to the posture correction unit 600 as shown in FIG. The posture correcting unit 510 controls the posture of the bonding head 170 based on the correction data 510 so that the bonding head 170 and the upper surfaces of the drive package 110 are parallel to each other.

6 is a flowchart illustrating a method for correcting a posture of a bonding head according to an embodiment of the present invention.

Referring to FIG. 6 , in order to correct the posture of the bonding head, the bonding head for bonding the bump formed on the driving package to the wiring is not parallel to the top surface of the driving package, and the driving package and the wiring are bonded to each other. The bumps are photographed by the vision unit to form a bump image, and the bump image is image-processed to store comparative contrast ratio data of the bumps of the driving package, inclination data and a code of the bonding head corresponding to the comparative contrast ratio data, respectively. (Step S10)

When the comparative contrast ratio data, the slope data, and the code are respectively stored, the bumps and wires of the driving package are pressed by using a bonding head to actually bond the bumps and wires. (Step S20)

When the bumps and wirings of the drive package are pressed and bonded by the bonding head, a bump image is generated by photographing the bumps bonded to the wirings from a lower part of the wirings. (Step S30)

In one embodiment of the present invention, the bump image may be generated after bonding the driving package and the wire n times (where n is a natural number equal to or greater than 1) by the bonding head, or the bump image may be generated after a certain period of time has elapsed.

When the bump image is generated, actual contrast ratio data of spaced apart bumps included in the bump image is calculated (step S40).

In this case, the actually measured contrast ratio data of the bumps disposed on the right side and the bumps disposed on the left side among the bumps may be calculated.

When the measured contrast ratio data is calculated, comparative contrast ratio data and the gradient data corresponding to the measured contrast ratio data are selected respectively (step S50).

When comparison contrast ratio data and tilt data corresponding to actually measured contrast ratio data are selected, correction data for correcting the tilt of the bonding head is calculated based on the selected tilt data (step S60).

The posture of the bonding head is adjusted by the correction data calculated by correcting the inclination of the bonding head so that the upper surfaces of the bonding head and the driving package are parallel to each other. (Step S70)

As described in detail above, it is possible to correct the posture of the bonding head corresponding to the upper surface of the driving package by determining the inclination of the upper surface of the bonding head and the driving package using the contrast ratio of the bonded bumps.

On the other hand, the embodiments disclosed in the drawings are only presented as specific examples to aid understanding, and are not intended to limit the scope of the present invention. It is obvious to those skilled in the art that other modified examples based on the technical idea of the present invention can be implemented in addition to the embodiments disclosed herein.

150...bonding unit 200...vision unit
300 ... data storage module 400 ... contrast ratio calculation unit
500 ... correction data calculation unit 600 ... posture correction unit

Claims (5)

a bonding unit including a bonding stage supporting a transparent circuit board on which wires connected to bumps of a driving package are formed, and a bonding head pressing the bumps to bond the bumps to the wires;
a vision unit generating a bump image by photographing the bumps bonded to the wiring at the bottom of the transparent circuit board;
When the driving package and the transparent circuit board are bonded to each other in a state where the bonding head is not parallel to the top surface of the driving package, comparative contrast ratio data of the bumps spaced apart from each other and the bonding head corresponding to the comparative contrast ratio data a data storage module in which gradient data and codes are stored;
a contrast ratio calculating unit which calculates actual contrast ratio data of the bumps included in the bump image;
a correction data calculation unit configured to select the comparative contrast ratio data and the tilt data corresponding to the actually measured contrast ratio data, and calculate correction data for correcting the tilt of the bonding head based on the selected tilt data; and
and a posture correction unit configured to adjust an inclination of the bonding head based on the correction data. According to claim 1,
wherein the contrast ratio calculating unit calculates the actually measured contrast ratio data using a first bump group that is a part of the bumps included in the bump image and a second bump group spaced apart from the first bump group by a predetermined distance. According to claim 2,
The first bump group is disposed on one outer edge of the bumps, and the second bump group is disposed on the other outer edge opposite to the one outer edge among the bumps. When the driving package and the wire are bonded to each other in a state where the bonding head is not parallel to the top surface of the driving package, comparative contrast ratio data of bumps of the driving package, inclination data of the bonding head corresponding to the comparative contrast ratio data, and a code storing each;
bonding the bumps and the wires by pressing the bumps and the wires of the driving package using the bonding head;
generating a bump image by photographing the bumps bonded to the wiring at a lower portion of the wiring;
calculating actual contrast ratio data of the bumps included in the bump image;
selecting the comparative contrast ratio data and the gradient data corresponding to the actually measured contrast ratio data, respectively;
Calculating correction data for correcting the tilt of the bonding head based on the selected tilt data; and
and adjusting the posture of the bonding head based on the calculated correction data. According to claim 4,
In the step of generating the bump image, the driving package and the wire are bonded n times (n is a natural number greater than 1) by the bonding head, and then the bump image is generated.

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