JP2022140934A - Chip component removal device - Google Patents

Abstract

To provide a chip component removal device capable of reducing equipment costs and shortening a process time when removing a defective chip component from a substrate on which many chip components are mounted by heating the components with a laser and transferring the components onto an adhesive film.SOLUTION: A chip component removal device includes a substrate stage that holds a substrate, a laser optical system that irradiates the substrate with a laser, adhesive film moving means capable of arranging an adhesive surface of an adhesive film so as to face a defective chip component mounted on the substrate held by the substrate stage, and a control unit that controls the laser optical system and the adhesive film moving means, and the laser optical system has a spatial light modulator, and the spatial light modulator can simultaneously irradiate a plurality of locations with a laser from one laser light source.SELECTED DRAWING: Figure 1

Description

The present invention relates to a chip component removing device for removing defective chip components from a board on which many chip components are mounted.

Development of a so-called micro LED display using LEDs with a size of several tens of microns called micro LEDs as pixels is progressing. Micro LED displays generally have a structure in which RGB micro LED chips are mounted on sub-pixels of a TFT substrate.

The number of micro LED chips used in a micro LED display is the same as the number of sub-pixels, which is a huge number. For example, a 4K display would require about 25 million micro LED chips.

Various methods have been proposed as methods for mounting such a huge number of chip components such as micro LEDs, and methods such as temporarily fixing a plurality of chip components to a carrier or stamp have been studied. Zero defects is extremely difficult. For example, defects such as misalignment and non-transfer to the substrate occur at a certain frequency. mounting failure occurs. For this reason, how to perform a rework operation for removing defectively mounted chip parts (hereinafter abbreviated as defective chip parts) and mounting non-defective chip parts has become a major issue.

Therefore, in rework work, a method of removing defective chip components using a laser is considered effective. That is, by using a laser with a small spot diameter, it is possible to irradiate and heat only defective chip components with pinpoint accuracy.

Here, it is preferable that the laser has a wavelength that can pass through the chip component, and the laser that has passed through the chip component is absorbed by the electrode (made of metal), heats the electrode, and melts the solder in the vicinity, causing defects. Chip parts can be removed from the board.

By the way, a method using an adhesive film has been proposed in order to easily remove a defective chip component with melted solder (for example, Patent Document 1). FIG. 7 shows a method of removing defective chip components using an adhesive film. In FIG. 7(a), the irradiation position of the laser light source 30 is aligned with the defective chip component Cd in the chip component C, and the adhesive film AF is adhered to the chip component C in FIG. 7(b). ), the defective chip component is heated by irradiating it with the laser L from the laser light source 3, and the adhesive film AF is moved away from the substrate S as shown in FIG. Cd is transferred to the adhesive film, and only the defective chip component Cd can be removed from the substrate S.

Korean Registered Patent KR10-1918106

Although a chip component with a size of several tens of μm can be easily removed by using an adhesive film, it takes 4 to 5 seconds for a series of operations from FIG. 7(a) to FIG. 7(d). Therefore, it takes more than 100,000 seconds, that is, more than 27 hours just to remove 25,000 chips. As a result, the productivity in the repair process becomes extremely poor.

Therefore, if a plurality of laser light sources are arranged to simultaneously heat a large number of defective chip components, the processing time can be shortened. However, multiple laser light sources inevitably increase the equipment cost. In addition, although it is possible to heat a plurality of chip components by using a wide laser such as a line laser, it is also difficult to prepare a mask that irradiates the laser only on defective chip components that occur randomly. .

The present invention has been made in view of the above problems, and suppresses equipment costs when removing defective chip parts from a substrate on which a large number of chip parts are mounted by heating them with a laser and transferring them to an adhesive film. It is an object of the present invention to provide a chip component removing apparatus capable of shortening the process time while reducing the time required for the process.

In order to solve the above problems, the invention according to claim 1,
A chip component removing device for removing defective chip components from a board on which a large number of chip components are mounted,
a substrate stage that holds the substrate;
The laser optical system for irradiating the substrate held by the substrate stage with a laser and the adhesive surface of the adhesive film can be arranged so as to face the defective chip component mounted on the substrate held by the substrate stage. Adhesive film moving means, and a control unit that controls the laser optical system and the adhesive film moving means,
The laser optical system has a spatial light modulator, and the chip component removing apparatus is capable of simultaneously irradiating a plurality of locations with a laser from one laser light source by means of the spatial light modulator.

The invention according to claim 2 is the chip component removing apparatus according to claim 1, which selectively irradiates a laser to a plurality of defective chip components to heat them.

The invention according to claim 3 is the chip component removing apparatus according to claim 1 or claim 2,
The chip component removing apparatus further comprises a pressing jig for evenly pressing the adhesive film against the defective chip component within a range in which the spatial light modulator can simultaneously irradiate the laser.

The invention according to claim 4 is the chip component removing apparatus according to any one of claims 1 to 3,
The spatial light modulator is a chip removal device using a spatial light phase modulation element that distributes light by means of a phase hologram.

The invention according to claim 5 is the chip component removing apparatus according to any one of claims 1 to 4,
In the chip component removing apparatus, the wavelength of the laser is in the range of 500 nm to 1400 nm, and the electrode of the defective chip component is heated by laser irradiation.

To shorten the process time while suppressing equipment costs in a chip component removing device for removing defective chip components from a board on which a large number of chip components are mounted by heating them with a laser and transferring them onto an adhesive film according to the present invention. became possible.

1 is an external view of a chip component removing device according to Embodiment 1 of the present invention; FIG. It is a figure explaining the component of the chip component removal apparatus which concerns on Embodiment 1 of this invention. 1 illustrates the process of removing a defective chip from a substrate of the chip component removing apparatus according to Embodiment 1 of the present invention, and shows (a) the alignment process, (b) the adhesion process, and (c) the heating process. and (d) a diagram showing an adhesive film separation step. FIG. 10 is a diagram illustrating a defective chip part in a laser irradiation area in the embodiment of the present invention; 2 illustrates the process of removing a defective chip from a substrate with a chip component removing apparatus according to Embodiment 2 of the present invention, (a) showing a state in which a pressing jig is in contact with an adhesive film, (b) showing a heating process, (c) It is a figure which shows an adhesive film separation process. (a) shows a laser irradiation area with a constant area, and (b) shows the area of the laser irradiation area so that the number of defective chip parts is constant. It is a figure which shows the example which changes . A conventional example of a method for removing chip components using an adhesive film will be described, showing (a) a positioning process for aligning the chip component and the irradiation position of the laser, and (b) a bonding process for adhering the adhesive film to the defective chip component. (c) shows a heating step of heating the defective chip component by irradiating it with a laser through the adhesive film, and (d) shows an adhesive film isolation step of isolating the adhesive film on which the defective chip component is transferred from the substrate. be.

An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing the appearance of a chip component removing apparatus 1 according to Embodiment 1 of the present invention, and FIG. ) is a diagram.

The chip component removing device 1 is a device for removing defective chip components Cd among a large number of chip components C mounted on a substrate S by transferring them onto an adhesive film AF. It is possible. Here, it is assumed that the substrate S is a TFT substrate and the chip component C is a micro LED chip with a size of several tens of μm, but the present invention is not limited to this, and the size of the chip component is from several tens to several tens. It can also be applied to a case of a mini-LED chip of several hundred μm, a millimeter-sized millimeter LED chip, or a case where the substrate S is a wiring board and the chip part is a semiconductor chip such as a memory element.

Adhesive film AF is a flexible film having adhesiveness on at least one surface, and may be a two-layer film in which an adhesive layer is provided on a base film. is preferably in the range of , and about 20 μm is particularly desirable. Also, a material having a transmittance of at least 50% and an absorptance of 10% or less, preferably a transmittance of 70% or more and an absorptance of 5% or less, is used with respect to the wavelength of the laser irradiated to the defective chip component Cd. As a specific material, a silicone-based resin is suitable.

The chip component removing apparatus 1 includes a base 100, a substrate stage 2, a laser optical system 3, an adhesive film moving means 4, and a control section 10 as constituent elements. In addition, a camera 5 may be provided for checking the positional relationship between the laser irradiation position and the defective chip component Cd, if necessary.

A base 100 is a main structure constituting the chip component removing apparatus 1 . It supports the substrate stage 2 .

The substrate stage 2 has the function of holding the substrate S by suction and adjusting the position of the substrate S in the in-plane direction. As shown in FIG. 1, the substrate stage 2 includes a suction table 20 that holds the substrate S by suction, a θ direction movable portion 21 that rotates the suction table 20 about the Z axis (θ direction), and is movable in the X direction. An X-direction movable portion 22 and a Y-direction movable portion 23 capable of moving in the Y direction are used as constituent elements. However, the substrate stage 2 is not limited to the configuration shown in FIG. 1, and may have any configuration as long as it can hold the substrate S on a flat surface and adjust its position in each of the X, Y and θ directions.

The laser optical system 3 irradiates a plurality of defective chip components Cd with a laser to heat the electrode portions (of each defective chip component Cd).

In the chip component removing apparatus 1 of Embodiment 1, the laser optical system 3 has a laser light source 30, a spatial light modulator 31, a mirror 32, and a condenser lens 33. A single laser beam emitted from the laser light source 30 It has a function of irradiating a defective chip component Cd with a plurality of beams.

The laser light source 30 emits a wavelength ranging from visible light to near-infrared, which heats the bump B while passing through an LED chip or a semiconductor chip. A specific wavelength is preferably in the range of 500 nm to 1400 nm.

The spatial light modulator 31 is composed of an address section and an optical modulation section. Information written to the address section changes the optical characteristics of the optical modulation section. It has a function of obtaining an output (specific light intensity distribution), and it is also possible to generate a plurality of laser beams from one laser beam by making use of this function. Here, generating a plurality of laser beams means that it is possible to simultaneously irradiate a plurality of locations instead of sequentially scanning one laser beam. In Embodiment 1, the LCOS, which is a spatial light phase modulator using liquid crystal, is used as the spatial light modulator 31, and light is distributed by a phase-type hologram (reflection method). However, it is not limited to this. do not have. For example, the spatial light modulator 31 may be a digital mirror device (DMD) in which drivable micromirrors are arranged.

The mirror 32 directs the laser distributed by the spatial light modulator 31 to the substrate S (on which the defective chip component Cd is mounted).

The condensing lens 33 converges the distributed laser beams so as to heat (the bumps B of) the defective chip component Cd.

The adhesive film moving means 4 disposes the adhesive film AF on the irradiation area of the plurality of distributed laser beams and moves it up and down. Adhesive film moving means 4 moves a conveying system that unwinds the adhesive film AF wound in a roll shape from an unwinding unit 4a, conveys it in a flat plate shape, and winds it into a roll shape by a winding unit 4b, and a conveying system. It is configured by a moving mechanism (not shown).

The camera 5 is used to measure the relative positional relationship between the position of the defective chip component Cd and the laser irradiation position, and can be used when aligning the defective chip component Cd and the laser irradiation position.

The control unit 10 controls the operation of the chip component removing apparatus 1, and is connected to the substrate stage 2, the laser light source 30 and the spatial light modulator 31 of the laser optical system 3, and the adhesive film moving means 4. 1 is equipped with a camera 5, it is connected to the camera 5; Also, the control unit 10 may have a function of transmitting/receiving data to/from an external device and storing the data. For example, information indicating which of the chip components C mounted on the substrate S is the defective chip component Cd may be received from an inspection device or the like and stored.

The control unit 10 is connected to the substrate stage 2 and has a function of turning on/off holding of the substrate S by suction and controlling the in-plane position of the suction table 20 .

The control unit 10 is connected to the laser light source 30 and has a function of controlling presence/absence of laser irradiation and output. It also has a function of controlling how the laser beam emitted from the laser light source 30 is distributed by connecting to the address section of the spatial light modulator 31 .

Furthermore, the control unit 10 may be connected to driving means for adjusting the positions and orientations of the mirror 32 or the condenser lens 33 to control the operations of the mirror 32 or the condenser lens 33 .

The control unit 10 is connected to the adhesive film moving means 4, has a function of controlling the unwinding unit 4a and the winding unit 4b to control the transportation of the adhesive film AF, and controls a moving mechanism (not shown) to control the unwinding unit. It has the function of adjusting the spatial position of the conveying system including 4a and winding section 4b.

In the case where the camera 5 is provided, the control unit 10 is connected to the camera 5 and has a function of inputting an image acquired by the camera 5 and analyzing positional information, and a function of controlling the spatial position of the camera 5. is doing.

A chip component removing method for removing the defective chip component Cd mounted on the board S with the chip component removing apparatus 1 according to the first embodiment of the present invention will be described below with reference to FIG. Note that FIG. 3 is a view of the chip component removing apparatus 1 viewed from the Y direction, as in FIG.

First, FIG. 3(a) shows an alignment step for grasping the positional relationship between the laser irradiation range and the substrate S and adjusting the relative position so that the defective chip component Cd can be irradiated with the laser.
. In the alignment step, if the laser irradiation area is fixed, the substrate stage 2 is moved to align the area where the chip component C (of the substrate S) is mounted within the laser irradiation area. At that time, it is desirable to obtain the positional information of the alignment marks SA provided at several places on the substrate S by the camera 5 and perform the alignment.

Here, the laser irradiation area is a range irradiated simultaneously by the laser beam distributed by the spatial light modulator 31 via the mirror 32 and the condenser lens 33 . FIG. 4 shows an example of the laser irradiation area AI viewed from above the substrate S. A plurality of chip components C are arranged in the laser irradiation area AI, some of which are defective chip components Cd. is.

In FIG. 3A, the position information of the alignment mark SA is acquired by the camera 5 while the adhesive film AF is placed facing the substrate S without contacting the defective chip component Cd (and chip component C). However, the alignment process is not limited to this. That is, when the adhesive film AF is optically cloudy, the position information of the alignment mark SA is acquired by the camera 5 without placing the adhesive film AF. It may be arranged opposite to the substrate S so as not to contact the component Cd (and the chip component C).

Further, although the substrate stage 2 is moved in the alignment process of the present embodiment, the present invention is not limited to this, and alignment is performed by moving the laser irradiation area AI of the laser optical system 3. good too. For example, the irradiation area AI can be moved by driving the mirror 32 or the condenser lens 33 . In this case, for example, an optical sensor such as the camera 5 or the like confirms the irradiation position of the laser beam split into a plurality by the spatial light modulator 31 as a reference spot (for alignment), and the position relative to the substrate S on the substrate stage 2 is detected. Aligning is good.

At this stage, the control unit 10 has obtained the position (address) information of the defective chip component Cd at any point within the laser irradiation area AI.

FIG. 3(b) shows an adhesion process in which the adhesive film moving means 4 adheres the adhesive film AF to the defective chip component Cd within the laser irradiation area AI after the alignment process. Thereafter, based on the positional information of the defective chip component Cd within the laser irradiation area AI possessed by the control unit 10, the spatial light modulator 31 distributes the laser beam to the location where the defective chip Cd exists. As shown in 3(c), the laser light source 30 emits laser light to heat the defective chip component Cd (heating step).

In the heating step, the bumps B of the defective chip component Cd are heated. Therefore, when the adhesive film AF is raised in the adhesive film separation process at the stage when the solder is melted, only the defective chip components Cd are transferred (at the same time) to the adhesive film AF and peeled off as shown in FIG. 3(d). can do

In this way, by distributing the laser beams by the spatial light modulator 31 as in the present embodiment, it is possible to simultaneously remove a plurality of defective chip components Cd with a single laser light source 30, thereby reducing equipment costs. It is possible to increase the efficiency (reduce the process time).

In this embodiment, the adhesion process of adhering the adhesive film AF to the defective chip part Cd as shown in FIG. Adhesion between the adhesive film AF and the defective chip component Cd at the time of irradiation is not an essential requirement. That is, the adhesive film AF and the defective chip component Cd may be brought into close contact after the irradiation of the laser L is started as a heating step while the adhesive film AF is not in contact with the defective chip component Cd. If the irradiation of the laser L is started while the adhesive film AF is not in contact with the defective chip component Cd, the temperature rise of the adhesive film AF can be suppressed. Therefore, the adhesive film AF can be reused because it can be prevented from being degraded by overheating.

By the way, with the device configuration shown in FIG. The contact state between the defective chip component Cd and the adhesive film AF may vary depending on the position inside. In such a case, some defective chip components Cd may not adhere to the adhesive film AF, which is not preferable.

Therefore, as a second embodiment of the present invention, a pressing jig 7 for evenly pressing the adhesive film AF against the defective chip component Cd (and chip component C) in the laser irradiation area may be used as shown in FIG. good. As the pressing jig 7, it is desirable to have transparency to the wavelength of the laser L and excellent flatness, as shown in FIG. 5(b).

As described above, according to the present invention, it is possible to simultaneously remove a plurality of defective chip components Cd from among the chip components C mounted on the substrate S.

On the other hand, tens of millions of micro LED chips are mounted on the micro LED display targeted by the present invention, and it is necessary to remove tens of thousands of them for repair, and it is impossible to remove them all at once. is. For this reason, a large number of laser irradiation areas AI as shown in FIG. FIG. 6A shows an example in which a plurality of laser irradiation areas AI exist within the substrate S. FIG. In such a case, the width (with respect to the transport direction) of the adhesive film AF may be matched with the width WAI of the laser irradiation area AI to avoid waste.

In FIG. 6A, the laser irradiation areas AI are all the same, but the number of defective chip components Cd in each of the laser irradiation areas AI(1), AI(2), AI(3), . are not the same. Therefore, when the power of the laser light source 30 is constant, if the number of branches of the laser beam in the spatial light modulator 31 differs depending on the number of defective chip components Cd in the laser irradiation area AI, each defective chip component Cd is irradiated. The power of laser L will be different. As a countermeasure for this, adjustment of the power of the laser light source and adjustment of the irradiation time can be considered according to the number of defective chip components Cd within the laser irradiation area. However, from the viewpoint of process stabilization, there is concern about changing conditions every short period of time.

Therefore, it is desirable to use a technique in which the power of the laser light source 30 is kept constant and the number of laser beams branched from the spatial light modulator 31 is kept constant, while the laser power applied to each defective chip component Cd is kept constant. Specifically, when the spatial light modulator 31 has a function of changing the focal length for each branch destination, the laser beams exceeding the number of the defective chip components Cd are directed away from the defective chip components Cd. There is a method of adjusting the focal length (so as not to heat the chip component C or the like) while branching. Alternatively, as shown in FIG. 3B, a method of changing the laser irradiation area AI (in the direction of narrowing the maximum range) so as to remove the same number (or approximately the same number) of defective chip components Cd each time may be used. .

REFERENCE SIGNS LIST 1 chip component removing device 2 substrate stage 3 laser optical system 4 adhesive film moving means 5 camera 7 pressing jig
10 control unit 30 laser light source 31 spatial light modulator 32 mirror 33 condenser lens 100 base AF adhesive film AI laser irradiation area B bump C chip part Cd defective chip part S substrate SA substrate alignment mark WAI width of laser irradiation area (adhesive width direction of the film)

Claims (5)

A chip component removing device for removing defective chip components from a board on which a large number of chip components are mounted,
a substrate stage that holds the substrate;
a laser optical system that irradiates a laser toward the substrate held by the substrate stage;
an adhesive film moving means capable of arranging the adhesive surface of the adhesive film so as to face the defective chip component mounted on the substrate held by the substrate stage;
A control unit that controls the laser optical system and the adhesive film moving means,
The laser optical system has a spatial light modulator, and the chip component removing device is capable of simultaneously irradiating a plurality of locations with a laser from one laser light source by means of the spatial light modulator. 2. The chip component removing apparatus according to claim 1, wherein a plurality of defective chip components are selectively irradiated with a laser to be heated. The chip component removing apparatus according to claim 1 or claim 2,
A chip component removing apparatus further comprising a pressing jig for uniformly pressing the adhesive film against the defective chip component within a range in which the spatial light modulator can simultaneously irradiate the laser. The chip component removing apparatus according to any one of claims 1 to 3,
The chip component removing apparatus, wherein the spatial light modulator uses a spatial light phase modulation element that distributes light by means of a phase hologram. The chip component removing apparatus according to any one of claims 1 to 4,
A chip component removing apparatus, wherein the wavelength of the laser is in the range of 500 nm to 1400 nm, and the electrode of the defective chip component is heated by laser irradiation.

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