JP7387666B2 - Chip parts removal equipment - Google Patents

Description

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

2. Description of the Related Art The development of so-called micro LED displays, in which pixels are LEDs with a size of several tens of microns called micro LEDs, is progressing. Micro LED displays generally have a structure in which RGB micro LED chips are mounted on subpixels of a TFT substrate.

The number of micro LED chips used in a micro LED display is the same as the number of subpixels, and is a huge number. For example, a 4K display requires approximately 25 million micro LED chips.

Various methods have been proposed for mounting a huge number of chip components such as micro LEDs, and methods such as temporarily fixing multiple chip components to a carrier or stamp are being considered. It is extremely difficult to eliminate defects. For example, defects such as misalignment or non-transfer to the board occur with a certain frequency, and even if the probability of occurrence of a mounting defect is 0.1%, there will be approximately 25,000 micro LED displays in a 4K display. A mounting defect occurs. Therefore, a major issue is how to perform rework work to remove defective chip components (hereinafter referred to as defective chip components) and mount good chip components.

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

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 (formed of metal), heats the electrode, and melts the nearby solder, causing defects. Chip components can be removed from the board.

By the way, in order to easily remove a defective chip component in which solder has melted, a method using an adhesive film has been proposed (for example, Patent Document 1). FIG. 7 shows a method for 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 in FIG. 7(b), the adhesive film AF is brought into close contact with the chip component C. ), the laser L is irradiated from the laser light source 3 to the defective chip component to heat it, and the adhesive film AF is moved away from the substrate S as shown in FIG. 7(d), thereby removing the defective chip component with the solder melted. 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 publication

By using an adhesive film, even chip parts with a size of several tens of micrometers can be easily removed, but the series of operations from FIG. 7(a) to FIG. 7(d) takes 4 to 5 seconds. Therefore, it takes more than 100,000 seconds, or more than 27 hours, just to remove 25,000 chips. For this reason, productivity in the repair process becomes extremely poor.

Therefore, the processing time can be shortened by arranging multiple laser light sources to simultaneously heat a large number of defective chip components. However, increasing the equipment cost by using multiple laser light sources is unavoidable. Furthermore, although it is possible to heat multiple chip components using a wide laser such as a line laser, it is also difficult to prepare a mask that irradiates only randomly occurring defective chip components with the laser. .

The present invention has been made in view of the above-mentioned problems, and reduces equipment costs when 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 to an adhesive film. The purpose of the present invention is to provide a chip component removing device that can reduce process time while also reducing the amount of time required.

In order to solve the above problem, the invention according to claim 1,
A chip component removal device that removes 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 and an adhesive surface of the adhesive film can be arranged so as to face a defective chip component mounted on the substrate held by the substrate stage. comprising an adhesive film moving means, a control section for controlling the laser optical system and the adhesive film moving means,
The laser optical system has a spatial light modulator, and is a chip component removing device that can simultaneously irradiate laser beams from one laser light source to a plurality of locations using the spatial light modulator.

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

The invention according to claim 3 is the chip component removal device according to claim 1 or claim 2,
The chip component removal apparatus further includes a pressing jig that evenly presses the adhesive film on the defective chip component within a range that allows simultaneous laser irradiation by the spatial light modulator.

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

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

According to the present invention, in a chip component removal device that removes 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 to an adhesive film, it is possible to reduce the process time while suppressing equipment costs. became possible.

1 is an external view of a chip component removing apparatus according to Embodiment 1 of the present invention. 1 is a diagram illustrating the components of a chip component removing apparatus according to Embodiment 1 of the present invention. FIG. This explains the process of removing a defective chip from the substrate of the chip component removal apparatus according to Embodiment 1 of the present invention, in which (a) shows the alignment process, (b) shows the adhesion process, and (c) shows the heating process. , (d) is a diagram showing an adhesive film separation step. It is a figure explaining the defective chip component of the laser irradiation area in embodiment of this invention. This explains the process of removing a defective chip from a board with the chip component removal apparatus according to Embodiment 2 of the present invention, (a) shows a state in which the pressing jig is in contact with the adhesive film, (b) shows a heating process, (c) It is a figure which shows an adhesive film separation process. This explains the laser irradiation area within a board on which a large number of chip components are mounted. It is a figure which shows the example which changes. This article describes a conventional method for removing chip components using an adhesive film, and shows (a) the alignment process of aligning the chip component and the laser irradiation position, and (b) the adhesion process of bringing the adhesive film into close contact with the defective chip component. (c) shows a heating process in which a defective chip component is heated by irradiating the defective chip component with a laser through the adhesive film, and (d) shows an adhesive film isolation process in which the adhesive film to which the defective chip component is transferred is separated from the substrate. be.

Embodiments of the present invention will be described using figures. FIG. 1 is a diagram showing the external appearance of a chip component removing apparatus 1 according to Embodiment 1 of the present invention, and FIG. ).

The chip component removal device 1 is a device that transfers and removes a defective chip component Cd among a large number of chip components C mounted on a substrate S onto an adhesive film AF, and is capable of removing a plurality of defective chip components Cd at the same time. 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 micrometers, but the present invention is not limited to this, and the chip components have a size of several tens of μm. It can also be applied to mini LED chips of several hundred μm, millimeter-sized millimeter LED chips, and cases where the substrate S is a wiring board and the chip component is a semiconductor chip such as a memory element.

Adhesive film AF is a flexible film that has adhesiveness on at least one side, and may be a two-layer film with an adhesive layer provided on the base film, and the thickness is 10 to 200 μm from the relationship between flexibility and strength. The thickness is preferably within the range of 20 μm, and particularly preferably about 20 μm. Further, a laser beam having a transmittance of at least 50% with respect to the wavelength of the laser irradiated to the defective chip component Cd, but an absorption rate of 10% or less, preferably a transmittance of 70% or more and an absorption rate of 5% or less, is used. As a specific material, silicone resin is suitable.

The chip component removal 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 components. Furthermore, a camera 5 may be provided for checking the positional relationship between the laser irradiation position and the defective chip component Cd, if necessary.

The base 100 is the main structure constituting the chip component removal 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 in the in-plane direction of the substrate S. As shown in FIG. 1, the substrate stage 2 is movable in the X direction with a suction table 20 that suction holds the substrate S, and a θ direction movable part 21 that rotates the suction table 20 about the Z axis (in the θ direction). The components include an X-direction movable section 22 and a Y-direction movable section 23 that is movable in the Y direction. 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 plane 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 laser to heat the electrode portion (of each defective chip component Cd).

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

The laser light source 30 emits wavelengths in the visible to near-infrared range that heat the bumps B while transmitting through the LED chip or semiconductor chip. The specific wavelength is preferably within the range of 500 nm to 1400 nm.

The spatial light modulator 31 is composed of an address section and a light modulation section, and changes the optical characteristics of the light modulation section according to information written to the address section, and modulates light according to the change, so that light reflecting the written information is generated. It has the function of obtaining an output (specific light intensity distribution), and it is also possible to generate multiple laser beams from one laser beam by taking advantage of this function. Here, generating multiple laser beams means that multiple locations can be irradiated simultaneously, rather than scanning one laser beam sequentially. In the first embodiment, an 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 hologram (reflection method), but the present invention 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 toward the substrate S (on which the defective chip component Cd is mounted).

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

The adhesive film moving means 4 places the adhesive film AF on the irradiation area of the plurality of distributed laser beams and moves it up and down. The adhesive film moving means 4 moves the conveyance system that unwinds the adhesive film AF wound into a roll from the unwinding section 4a, conveys it in a flat plate shape, and winds it up into a roll shape by the winding section 4b, and the conveyance system. It is constituted 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 with the laser irradiation position.

The control unit 10 controls the operation of the chip component removing device 1, and is connected to the substrate stage 2, the laser light source 30 of the laser optical system 3, the spatial light modulator 31, and the adhesive film moving means 4, and is connected to the substrate stage 2, the laser light source 30 of the laser optical system 3, and the adhesive film moving means 4. If 1 is equipped with a camera 5, it is connected to the camera 5. Further, the control unit 10 may have a function of transmitting/receiving data to/from an external device and storing data. For example, information regarding which of the chip components C mounted on the substrate S is a 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 suction and holding of the substrate S and controlling the position of the suction table 20 in the in-plane direction.

The control unit 10 is connected to the laser light source 30 and has the function of controlling whether or not laser irradiation is performed and the output. It also has a function of connecting to the address section of the spatial light modulator 31 and controlling how the laser beam emitted from the laser light source 30 is distributed.

Further, the control unit 10 may be connected to a driving means for adjusting the position and direction of the mirror 32 or the condensing lens 33 to control the operation of the mirror 32 or the condensing lens 33.

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

In addition, when the camera 5 is provided, the control unit 10 has a function of connecting to the camera 5, inputting images acquired by the camera 5 and analyzing position information, and a function of controlling the spatial position of the camera 5. are doing.

Hereinafter, a chip component removing method for removing a defective chip component Cd mounted on the substrate S using the chip component removing apparatus 1 according to the first embodiment of the present invention will be described using FIG. 3. Note that, like FIG. 2, FIG. 3 is a diagram of the chip component removing apparatus 1 viewed from the Y direction.

First, FIG. 3A shows a positioning step in which the positional relationship between the laser irradiation range and the substrate S is grasped and the relative positions are adjusted so that the defective chip component Cd can be irradiated with the laser.
. In the positioning step, if the laser irradiation area has been determined, the substrate stage 2 is moved to align the region (of the substrate S) where the chip component C is mounted within the laser irradiation area. At that time, it is desirable that positional information of alignment marks SA provided at several locations on the substrate S be acquired by the camera 5 to perform positioning.

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

In FIG. 3(a), the positional 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 the chip component C). However, the alignment process is not limited to this. That is, if the adhesive film AF is optically cloudy, the camera 5 acquires the position information of the alignment mark SA without the adhesive film AF placed, and then the adhesive film moving means 4 removes the adhesive film AF from the defective chip. It may be arranged to face the substrate S so as not to come into contact with the component Cd (and the chip component C).

Furthermore, although the substrate stage 2 is moved in the alignment process of this 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 condensing lens 33. In this case, for example, an optical sensor such as the camera 5 confirms the irradiation position of a plurality of laser beams branched by the spatial light modulator 31 as a reference spot (for positioning), and determines the position relative to the substrate S on the substrate stage 2. It's best to align.

Note that, at this stage, the control unit 10 has acquired the position (address) information of the defective chip component Cd within the laser irradiation area AI.

FIG. 3B shows a close contact step in which the adhesive film moving means 4 brings the adhesive film AF into close contact with the defective chip component Cd within the laser irradiation area AI after the positioning step. Thereafter, the spatial light modulator 31 distributes the laser beam to the location where the defective chip Cd exists based on the position information of the defective chip component Cd within the laser irradiation area AI held by the control unit 10, and then, as shown in FIG. 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 where the solder is melted, only the defective chip components Cd (multiple pieces at the same time) are transferred to the adhesive film AF and peeled off, as shown in FIG. 3(d). I can do it.

As described above, by distributing the laser beam using the spatial light modulator 31 as in the present embodiment, it becomes possible to simultaneously remove a plurality of defective chip components Cd with one laser light source 30, thereby suppressing equipment costs. However, it is possible to increase efficiency (shorten process time).

Note that in this embodiment, the adhesion step of bringing the adhesive film AF into close contact with the defective chip component Cd as shown in FIG. 3(b) is changed to the heating step of irradiating the laser L as shown in FIG. 3(c). 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 with each other after the laser L irradiation is started as a heating step in a state where the adhesive film AF is not in contact with the defective chip component Cd. If the laser L irradiation is started in a state where 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 prevented from deteriorating in quality due to overheating, and thus can be reused.

By the way, in the device configuration shown in FIG. 2, when trying to bring the adhesive film AF into close contact with the defective chip component Cd by the adhesive film moving means 4 as shown in FIGS. 3(a) to 3(b), the laser irradiation area The state of contact between the defective chip component Cd and the adhesive film AF may differ depending on the position within. In such a case, there may be a case where some of the defective chip components Cd do not come into close contact with the adhesive film AF, which is not preferable.

Therefore, as a second embodiment of the present invention, as shown in FIG. good. The pressing jig 7 is preferably one that is transparent to the wavelength of the laser L and has 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, micro-LED displays such as the one targeted by the present invention are equipped with tens of millions of micro-LED chips, and it is necessary to remove tens of thousands of micro-LED chips for repair, which is impossible to remove all at once. It is. Therefore, a large number of laser irradiation areas AI as shown in FIG. 4 exist within (one) substrate S. FIG. 6A shows an example in which a plurality of laser irradiation areas AI exist within the substrate S. In such a case, if the width of the adhesive film AF (with respect to the transport direction) is matched to the width WAI of the laser irradiation area AI, there is no waste.

In FIG. 6(a), the laser irradiation areas AI are all the same, but the number of defective chip components Cd in each laser irradiation area AI(1), AI(2), AI(3), etc. 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 the laser L will be different. As a countermeasure to this problem, it is possible to adjust the power of the laser light source and the irradiation time depending on the number of defective chip components Cd within the laser irradiation area. However, from the perspective of process stabilization, there are concerns about changing conditions every short period of time.

Therefore, it is desirable to use a method 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 irradiated 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, if the number of laser beams exceeds the number of defective chip components Cd, the laser beams are moved in the direction 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 etc.) while branching. Alternatively, as shown in FIG. 3(b), a method may be used in which the laser irradiation area AI is changed (in the direction of narrowing the maximum range) so that the same number (or almost the same number) of defective chip components Cd are removed each time. .

1 Chip component removal 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 Condensing lens 100 Base AF Adhesive film AI Laser irradiation area B Bump C Chip component Cd Defective chip component S Substrate SA Board alignment mark WAI Width of laser irradiation area (adhesive (width direction of film)

Claims (5)

A chip component removal device that removes 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 an adhesive surface of the adhesive film to face a defective chip component mounted on a substrate held by the substrate stage;
comprising 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 laser beams from one laser light source to multiple locations using the spatial light modulator. The chip component removal apparatus according to claim 1, wherein the chip component removal apparatus selectively irradiates a plurality of defective chip components with a laser to heat them. The chip component removal device according to claim 1 or 2,
A chip component removal device further comprising a pressing jig that evenly presses the adhesive film on the defective chip component within a range that allows simultaneous laser irradiation by the spatial light modulator. The chip component removal device according to any one of claims 1 to 3,
A chip component removal apparatus in which the spatial light modulator uses a spatial light phase modulation element that distributes light using a phase type hologram. The chip component removal device according to any one of claims 1 to 4,
A chip component removal device in which 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.