KR102245399B1 - Apparatus for laser bonding with ACF bonding temperature control by real-time laser power regulation - Google Patents

Abstract

The present invention relates to a laser bonding apparatus capable of controlling anisotropic conductive film (ACF) bonding temperature through real-time laser power control. According to the present invention, the laser bonding apparatus comprises: a laser irradiation unit for controlling the heating temperature of an object by controlling the power of a laser irradiated to a display panel and a chip on flexible printed circuit (COF) or an ACF junction portion of the display panel and a printed circuit board (PCB) by generating a laser; a fixing unit having a through hole for concentrating the laser so as not to be dispersed, and ascending and descending; a transmissive unit made of a transparent material and formed to transmit the laser; a temperature measuring unit formed on an upper side of the object to measure the temperature of the junction portion of the object to measure the temperature in a diagonal direction; and a control unit in which a temperature set value provided by a manufacturer of the object, the ACF, is stored for DB, and which selects a bonding temperature of the ACF of the manufacturer to be used among the stored temperature set values, and controls the power of the laser generated from the laser irradiation unit in real time through the temperature of the junction portion of the selected object measured by the temperature measuring unit.

Description

Apparatus for laser bonding with ACF bonding temperature control by real-time laser power regulation

The present invention relates to a laser bonding device capable of adjusting ACF bonding temperature through real-time laser power control, and more particularly, to the bonding characteristics of a manufacturer's ACF when ACF bonding a display panel and a COF or a display panel and an FPCB using a laser. After measuring by setting a suitable temperature, the fusion temperature can be maintained by controlling the power of the laser and irradiating it in real time.

This real-time laser power control interlocks the laser and the non-contact temperature measuring instrument (Pyrometer), and the measuring point of the non-contact temperature measuring instrument is set at the junction of the display panel and the COF or FPCB, and the desired time ( second) to the set temperature.

In addition, using this feedback system, it is possible to set a target temperature for each desired arrival time. (ex: The target temperature is 160 degrees, reaching 140 degrees within 2 seconds, and then reaching 160 degrees until 6 seconds)

In addition, among the essential elements necessary for bonding, the pressure applied to the sample is made of quartz, and after pressing the sample and applying pressure, the laser light penetrates the quartz and focuses on the sample and heats through the reaction of optical absorption, transmission, and reflection from the sample. This occurs, and a non-contact thermometer detects the generated heat, and relates to a laser bonding device for reaching a set target temperature by interlocking and feedback with the laser.

In general, an anisotropic conductive film (ACF) is a double-sided tape in which an adhesive cured by heat and fine conductive balls are mixed therein. When high temperature pressure is applied, the pad (bump) of a circuit pattern, that is, a pattern electrode When the conductive ball in contact with the part is destroyed, the broken conductive ball is energized with the pattern electrode, and the remaining adhesive is filled/cured on the uneven surface other than the pattern electrode part to adhere to each other.

That is, ACF is a film adhesive in which conductive particles such as metal-coated plastic or metal particles (referred to as conductive balls) are dispersed, and the LCD panel and TCP (Tape Carrier Package) or It is widely used for electrical connection of PCB (Printed Circuit Board) and TCP.

With the recent development of LCD technology, ACF is rapidly improving connection reliability and miniaturization of the connection pitch. As a result, COG (Chip On), which directly connects and mounts a bare chip to an LCD panel. Glass) mounting, etc. became possible.

If ACF is attached between the two surfaces to be bonded and heat is applied while pressing a hot bar on the surface of the upper part with a certain pressure, the thermosetting resin is cured over time, resulting in the effect of bonding the two contact surfaces. Electricity flows in only one direction due to the conductive particles dispersed and present.

Since such heat transfer is transferred to the ACF through the upper part surface and through the part, it is important to have a constant heat transfer temperature distribution characteristic.

However, the existing heat fusion process and apparatus using a hot bar uses a heater to heat and control the heat required for ACF heat fusion, so that the entire hot bar has a uniform temperature. It is difficult, and the heat conversion efficiency is low because heat consumption is large other than the connection part, and when the hot bar is continuously used, the surface of the hot bar is contaminated, making it difficult to secure reproducibility.

In addition, there was a difficulty in optimizing the connection conditions according to the target use, and in the case of a semi-automated process, there was a problem that the quality was influenced by the experience and skill of the operator.

In order to solve this problem, the prior patent is applied to the bonding apparatus of an anisotropic conductive film (ACF) that connects the bonding sample to the bonding substrate with an anisotropic conductive film (ACF) by generating a laser beam of a predetermined wavelength, inducing it to the connection part, and heating it. In this regard, the anisotropic conductive film (ACF) using a laser, characterized in that it is configured so that only the connection portion can be partially heated by partially passing the laser beam by a pattern mask in which a slot corresponding to the pattern electrode shape of the bonding substrate and the bonding sample is formed. ) Of the bonding control device is described.

However, the prior patent can control the temperature of the bonding site according to the bonding temperature characteristics of the ACF film, but since the contact type temperature sensor is used, the contact type temperature sensor is planted in the sample to manage the process temperature at regular intervals, which is cumbersome to manage. There is a problem, and there is a problem in that the process temperature varies depending on the location where the temperature sensor is planted.

Prior patent: Korean Registered Patent Publication No. 10-0867587 (2008.11.03.)

In the present invention, when ACF bonding the display panel and COF or the display panel and FPCB using a laser, the temperature is measured according to the bonding temperature characteristics of the manufacturer's ACF, and the fusion temperature can be controlled by controlling the power of the laser in real time and irradiating it. Among the essential elements necessary for bonding, the pressure applied to the sample is made of quartz, and after pressing the sample and applying pressure, the laser light passes through the quartz and focuses on the sample and through the reaction of optical absorption, transmission, and reflection from the sample. A laser bonding device capable of adjusting the ACF bonding temperature through real-time laser power control that generates heat and senses the generated heat by a non-contact thermometer and reaches the set target temperature in real time by interlocking and feedback with the laser. It has its purpose to provide..

A laser bonding device capable of controlling ACF bonding temperature through real-time laser power control according to the present invention for achieving the above object is a display panel and a COF (Chip On Flexible Printed Circuit) or a display panel and a PCB ( A laser irradiation unit for controlling a heating temperature of an object by controlling the power of the laser irradiated to the ACF (Anisotropic Conductive Film) junction of the printed circuit board); A fixing part through which the laser irradiated by the laser irradiation part passes in a vertical direction, a through hole for concentrating the laser to be dispersed is formed, and which is lifted; A transmission part formed in a shape corresponding to the through hole of the fixing part, descending through the fixing part to pressurize an object to be compressed, and formed of a transparent material to transmit a laser; The temperature measurement unit is formed on the upper side of the object to measure the temperature of the junction of the object and measures the temperature in a diagonal direction, and the laser irradiation unit and the temperature measurement unit are connected, and the temperature set value provided by the manufacturer of the ACF film as the object is Selects the temperature at which the ACF of the manufacturer to be used is bonded among the temperature set values stored in DB and stored, and the power of the laser generated by the laser irradiation unit is measured through the temperature of the junction of the selected object measured by the temperature measuring unit. It characterized in that it comprises a control unit that adjusts in real time.

The through hole and the transmission part are formed with the same width from the top to the bottom, the other side of the top is wide, the bottom of the one side has the same width as the top, the other side is formed narrow, and the other side is gradually diagonal from the top. It is characterized in that the inclination is formed and narrowed in the direction so that the laser light is not dispersed.

The temperature measuring unit measures the temperature in a diagonal outer or longitudinal direction of the joint portion of the object to measure the temperature of the portion to which the object is joined, and comprises an infrared temperature sensor and measures the temperature in a non-contact manner at a spaced position. .

The method of the present invention comprises the steps of selecting an ACF bonding temperature (target temperature) and a temperature profile of the manufacturer set in the control unit; When the ACF (3) bonding temperature (target temperature) and the temperature profile are selected, the transmissive part 50 is lowered and the display panel 1 and COF 2 as objects or the ACF 3 of the display panel 1 and the PCB Irradiating a laser after applying pressure to the bonding portion at a set pressure value (S20);

Measuring a temperature generated in an object according to the irradiated laser through a non-contact temperature measuring unit 30 in real time (S30);

By comparing the measured temperature with the ACF (3) bonding temperature (target temperature) and temperature profile set by the control unit 10, the laser power is increased or decreased to enable bonding with a desired temperature profile up to the target temperature value to reduce the laser power to the target temperature. It characterized in that it comprises a step (S40) of irradiation.

In the step of irradiating the laser by increasing or decreasing the laser power (S40), the ACF (3) bonding temperature (target temperature) and the ACF (3) are heated to a desired temperature profile, through feedback with the non-contact temperature measuring unit (30). It is characterized in that the power is increased or decreased in real time to be irradiated.

In the present invention, when ACF bonding a display panel and a COF or a display panel and an FPCB using a laser, the temperature is measured according to the bonding temperature characteristics of the manufacturer's ACF, and the fusion temperature can be controlled by controlling the power of the laser in real time. It works.

In addition, the laser light is concentrated and irradiated without being dispersed through the through hole and the transmitting part of the fixing part, so that there is no loss of laser light.

1 is a view showing the overall configuration of a laser bonding apparatus capable of controlling ACF bonding temperature through real-time laser power adjustment according to an embodiment of the present invention.
2 is a view showing the shape of a transmission part of a laser bonding apparatus capable of controlling ACF bonding temperature through real-time laser power adjustment according to the present invention.
3 is a view showing bonding (bonding) ACF of a laser bonding apparatus capable of controlling ACF bonding temperature through real-time laser power adjustment according to the present invention.
4 is a non-contact method of measuring the temperature of an object heated by a laser during laser bonding of a laser bonding device capable of controlling ACF bonding temperature through real-time laser power control according to the present invention, and increasing or decreasing the laser output over time according to the temperature feedback. It is a figure showing what is made.
5 is a flowchart of a bonding method using a laser bonding device capable of adjusting ACF bonding temperature through real-time laser power control according to the present invention.

Hereinafter, a specific embodiment for implementing the present invention will be described with reference to the drawings. The embodiments of the present invention are for explaining one invention, and the scope of the rights is not limited to the illustrated embodiments, and the illustrated drawings are limited to the drawings because only the essential contents are enlarged for clarity of the design, and ancillary items are omitted. Therefore, it should not be interpreted.

The present invention generates a laser to generate an ACF (3) (Anisotropic Conductive) of the display panel (1) and COF (2) (Chip On Flexible Printed Circuit) or the display panel (1) and PCB (2) (Printed Circuit Board) as targets. Film) laser irradiation unit 20 for controlling the heating temperature of the object by controlling the power of the laser irradiated to the junction; The laser irradiated by the laser irradiation unit 20 is passed in a vertical direction, a through hole 41 is formed to concentrate the laser so that the laser is not dispersed, and a fixing unit 40 that is elevated and lowered; A transmission part 50 formed in a shape corresponding to the through hole 41 of the fixing part 40, descending through the fixing part to pressurize an object to be compressed, and formed of a transparent material to transmit a laser; A temperature measuring unit 30 formed on the upper side of the object to measure the temperature in a diagonal direction and the laser irradiation unit 20 and the temperature measuring unit 30 are connected to measure the temperature of the junction of the object, and the object ACF The temperature set value provided by the film manufacturer is converted into a DB and stored, and among the stored temperature set values, the temperature at which the ACF of the corresponding manufacturer to be used is bonded is selected, and the selected object measured by the temperature measuring unit 30 is bonded. It characterized in that it comprises a control unit 10 for controlling the power of the laser generated in the laser irradiation unit 20 through the site temperature in real time.

The through hole 41 and the transmission part 50 are formed with the same width on one side from the top to the bottom, the other side of the upper side is wide, and the lower side has the same width as the top and the other side is formed narrow, It is characterized in that the other side is formed gradually in a diagonal direction from the upper side and is narrowed so that the laser light is not scattered.

The temperature measuring unit 30 measures the temperature in the diagonal outside of the joint portion or in the longitudinal direction of the joint portion to measure the temperature of the portion to which the object is joined, and consists of an infrared temperature sensor to measure the temperature in a non-contact manner at a spaced position. It is characterized by that.

The real-time temperature control method of the present invention comprises the steps of selecting an ACF (3) bonding temperature (target temperature) and a temperature profile of the manufacturer set in the control unit 10 (S10); When the ACF (3) bonding temperature (target temperature) and the temperature profile are selected, the transmissive part 50 is lowered and the display panel 1 and COF 2 as objects or the ACF 3 of the display panel 1 and the PCB Irradiating a laser after applying pressure to the bonding portion at a set pressure value (S20); Measuring a temperature generated in an object according to the irradiated laser through a non-contact temperature measuring unit 30 in real time (S30); By comparing the measured temperature with the ACF (3) bonding temperature (target temperature) and temperature profile set by the control unit 10, the laser power is increased or decreased to enable bonding with a desired temperature profile up to the target temperature value to reduce the laser power to the target temperature. It characterized in that it comprises a step (S40) of irradiation.

In the step of irradiating the laser by increasing or decreasing the laser power (S40), the ACF (3) bonding temperature (target temperature) and the ACF (3) are heated to a desired temperature profile, through feedback with the non-contact temperature measuring unit (30). It is characterized in that the power is increased or decreased in real time to be irradiated.

1 is a diagram showing the overall configuration of a laser bonding apparatus capable of controlling ACF bonding temperature through real-time laser power adjustment according to an embodiment of the present invention, and a display panel 1 and a COF 2 as targets by generating a laser (Chip On Flexible Printed Circuit) or by controlling the heating temperature of the object by controlling the power of the laser irradiated to the junction of the ACF (3) (Anisotropic Conductive Film) of the display panel (1) and the PCB (2) (Printed Circuit Board). A laser irradiation unit 20; The laser irradiated by the laser irradiation unit 20 passes in a vertical direction, a through hole 41 for concentrating the laser to be dispersed is formed, and a fixing unit 40 that is elevated and lowered; A transmission part 50 formed in a shape corresponding to the through hole 41 of the fixing part 40, descending through the fixing part to pressurize an object to be compressed, and formed of a transparent material to transmit a laser; A temperature measuring unit 30 formed on the upper side of the object to measure the temperature in a diagonal direction and the laser irradiation unit 20 and the temperature measuring unit 30 are connected to measure the temperature of the junction of the object, and the object ACF The temperature set value provided by the film manufacturer is converted into a DB and stored, and among the stored temperature set values, the temperature at which the ACF of the corresponding manufacturer to be used is bonded is selected, and the selected object measured by the temperature measuring unit 30 is bonded. It includes a control unit 10 that adjusts the power of the laser generated in the laser irradiation unit 20 through the site temperature in real time.

FIG. 2 is a view showing the shape of a transmission part of a laser bonding device capable of controlling ACF bonding temperature through real-time laser power control according to the present invention, and FIG. 3 is a laser capable of controlling ACF bonding temperature through real-time laser power control according to the present invention. It is a diagram showing the bonding (bonding) of the ACF of the bonding apparatus, and FIG. 4 is a non-contact temperature of an object heated by a laser during laser bonding of a laser bonding apparatus capable of controlling ACF bonding temperature through real-time laser power adjustment according to the present invention. It is a diagram showing that the laser output is increased or decreased over time according to the feedback of the temperature by measuring.

1 to 4, the irradiation unit generates a laser so that the display panel 1 and COF 2 (Chip On Flexible Printed Circuit) or the display panel 1 and PCB 2 (Printed Circuit Board) are objects by generating a laser. ), and the power of the laser is controlled through the control of the control unit 10 to control the heating temperature of the bonding area of the object.

In this case, the PCB (2) (Printed Circuit Board) may be formed of FPC, TCP, or PWB.

The irradiation unit may include a generator 21 that generates a laser, an extension 22 that expands the generated laser, and an irradiator 23 that irradiates the laser.

The laser irradiated through the irradiation unit passes through the transmission unit 50 coupled to the fixing hole of the fixing unit 40 to allow the laser distributed to the outside to be concentrated to be irradiated to the object.

The fixing part 40 is formed under the irradiation part to form a through hole 41 through which the laser irradiated from the irradiation part penetrates, and the through hole 50 is inserted into the through hole 41.

At this time, a fixture is coupled to cover a part of the upper side of the transmission part 50 so as to fix the upper side of the transmission part 50.

This allows the transmission part 50 to be compressed by pressing the object due to the lowering of the fixing part.

When the permeable part 50 descends through the fixing part 40, the support is raised from the lower part of the object to pressurize the object together with the permeable part 50 in both directions to be compressed.

The through hole 41 is formed with the same width from the top to the bottom, the other side of the top is wide, the bottom of the through hole 41 has the same width as the top and the other side is formed narrowly, and the other side is gradually formed from the top. The inclination is formed in a diagonal direction and narrows, so that the laser light is not scattered.

The transmission part 50 coupled to the through hole 41 is formed in a shape corresponding to the shape of the through hole 41 and is inserted from the upper side of the through hole 41 to be coupled. The transmission part 50 is inserted into the through hole 41 of the fixing part 40 to be coupled.

The transmission part 50 is formed to correspond to the shape of the through hole 41 and is coupled to the through hole 41, one side has the same width from the top to the bottom, the other side of the top is wide, and the bottom One side has the same width as the upper side and the other side is formed narrowly, and the other side is formed to be narrowed and gradually formed in a diagonal direction from the upper side to prevent the laser light from being scattered.

The inclination of the through hole 41 and the transmission part 50 in the diagonal direction may be formed only on the middle side, which is inside a predetermined interval from the top and bottom sides.

When the laser irradiated to the bonding area of the object through the transmission unit 50 heats the bonding area, a temperature measuring unit 30 that measures the temperature of the bonding area and transmits it to the control unit 10 is formed.

The temperature measuring unit 30 measures the temperature outside the diagonal of the joint portion of the object to measure the temperature of the portion to which the object is joined, and measures the temperature in a non-contact manner at a spaced position using a laser or infrared temperature sensor.

The temperature measured by the temperature measuring unit 30 is transmitted to the control unit 10 so that the control unit 10 increases the temperature of the bonding site to the set bonding temperature of the control unit 10 that is set according to the characteristics of the bonding temperature of the object. The power of the laser irradiated by the laser irradiation unit 20 is adjusted by the control unit 10,

At this time, since the power of the laser controlled by the control unit 10 is controlled while measuring the temperature of the junction of the object in real time, the power is not continuously increased along the curved shape, but a predetermined value set according to the curved shape. The power of the laser is increased along the curve in a zigzag shape that repeats increasing and decreasing within the range.

Alternatively, the power of the laser along the curve in a zigzag shape repeating increase and decrease within a predetermined range by increasing the power of the laser to the maximum initially to increase the temperature of the joint, and by measuring the temperature in real time to decrease the laser power. You can also try to increase.

5 is a flowchart of a bonding method using a laser bonding device capable of adjusting ACF bonding temperature through real-time laser power control according to the present invention.

Referring to Figure 5, the ACF (3) bonding heating method using this configuration is as follows.

This bonding method includes the steps of selecting an ACF (3) bonding temperature (target temperature) and a temperature profile of the manufacturer set in the control unit 10 (S10); When the ACF (3) bonding temperature (target temperature) and the temperature profile are selected, the transmissive part 50 is lowered and the display panel 1 and COF 2 as objects or the ACF 3 of the display panel 1 and the PCB Irradiating a laser after applying pressure to the bonding portion at a set pressure value (S20); Measuring a temperature generated in an object according to the irradiated laser through a non-contact temperature measuring unit 30 in real time (S30); By comparing the measured temperature with the ACF (3) bonding temperature (target temperature) and temperature profile set by the control unit 10, the laser power is increased or decreased to enable bonding with a desired temperature profile up to the target temperature value to reduce the laser power to the target temperature. It includes a step (S40) of irradiation.

First, the ACF (3) bonding temperature (target temperature) and temperature profile of the manufacturer set in the control unit 10 are selected (S10).

At this time, since the heating temperature of the ACF 3 is different for each manufacturer, the ACF 3 bonding temperature of each company is converted into a database and stored in the control unit 10.

When the ACF (3) bonding temperature (target temperature) and the temperature profile are selected, the transmissive part 50 is lowered and the display panel 1 and COF 2 as objects or the ACF 3 of the display panel 1 and the PCB The laser is irradiated after applying pressure to the joint at the set pressure value (S20).

The temperature generated in the object according to the irradiated laser is measured in real time through the non-contact temperature measuring unit 30 and transmitted to the control unit (S30);

By comparing the measured temperature with the ACF (3) bonding temperature (target temperature) and temperature profile set by the control unit 10, the laser power is increased or decreased to enable bonding with a desired temperature profile up to the target temperature value to reduce the laser power to the target temperature. Investigate (S40).

At this time, when irradiating the laser by increasing or decreasing the laser power, the ACF 3 is heated by drawing a curve up to the heating temperature set in the control unit 10 according to the temperature due to the heating of the laser, and the power of the laser increases along the curve. Or reduced to allow irradiation.

In the step of irradiating the laser by increasing or decreasing the laser power (S40), the ACF (3) bonding temperature (target temperature) and the ACF (3) are heated to a desired temperature profile, through feedback with the non-contact temperature measuring unit (30). The power is increased or decreased in real time to be irradiated.

According to the present invention made in this way, when ACF bonding the display panel and the COF or the display panel and the FPCB using a laser, the temperature is measured according to the bonding temperature characteristics of the manufacturer's ACF, and the power of the laser is adjusted in real time and irradiated to adjust the fusion temperature. It has a controllable effect.

In addition, the laser light is concentrated and irradiated without being dispersed through the through hole and the transmitting part of the fixing part, so that there is no loss of laser light.

The laser bonding apparatus capable of controlling the ACF bonding temperature through real-time laser power adjustment as described above is not limited to the configuration and operation method of the above-described embodiments. The above embodiments may be configured so that all or a part of each of the embodiments may be selectively combined so that various modifications may be made.

1: Display panel 2: COF or PCB
3: ACF
10: control unit
20: laser irradiation unit 21: generator
22: expansion body 23: irradiation body
30: temperature measuring unit
40: fixed part 41: through hole
50: transmission part

Claims (5)

A laser is generated to connect the display panel (1) and the COF (2) (Chip On Flexible Printed Circuit) or the ACF (3) (Anisotropic Conductive Film) connection between the display panel (1) and PCB (2) (Printed Circuit Board). A laser irradiation unit 20 for controlling a heating temperature of an object by controlling the power of the laser irradiated upward;
The laser irradiated by the laser irradiation unit 20 passes in a vertical direction, a through hole 41 for concentrating the laser to be dispersed is formed, and a fixing unit 40 that is elevated and lowered;
A transmission part 50 formed in a shape corresponding to the through hole 41 of the fixing part 40, descending through the fixing part to pressurize an object to be compressed, and formed of a transparent material to transmit a laser;
A temperature measuring unit 30 formed on the upper side of the object to measure the temperature at the junction of the object and measuring the temperature in a diagonal direction, and
The laser irradiation unit 20 and the temperature measuring unit 30 are connected, and the temperature set value provided by the manufacturer of the ACF film as a target is converted into a DB and stored, and the ACF of the corresponding manufacturer to be used among the stored temperature set values is Characterized in that it comprises a control unit 10 that selects the temperature to be bonded, and adjusts the power of the laser generated by the laser irradiation unit 20 in real time through the temperature of the junction of the selected object measured by the temperature measurement unit 30 A laser bonding device capable of controlling ACF bonding temperature through real-time laser power control.
The method of claim 1,
The through hole 41 and the transmission part 50 are formed with the same width from the upper side to the lower side, the other side of the upper side is formed wide, the lower side has the same width as the upper side and the other side is formed narrowly, A laser bonding device capable of controlling ACF bonding temperature through real-time laser power control, characterized in that the other side is formed by gradually forming an inclination in a diagonal direction from the top and narrowing so that the laser light is not scattered.
The method of claim 1,
The temperature measuring unit 30 measures the temperature in the diagonal outside of the joint portion or in the length direction of the joint portion to measure the temperature of the portion to which the object is joined, and consists of an infrared temperature sensor to measure the temperature in a non-contact manner at a spaced position. A laser bonding device capable of controlling ACF bonding temperature through real-time laser power control, characterized in that.
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