TWI896626B - Mounting method, mounting device, and transfer device - Google Patents

Abstract

The present invention provides a mounting method, mounting apparatus, and transfer apparatus for mounting semiconductor chips on a circuit substrate with high productivity. Specifically, the mounting method of the present invention comprises: a first transfer step of transferring a plurality of semiconductor chips 1 formed on a carrier substrate 2 to a first transfer substrate 4a; an inspection step of inspecting the condition of the semiconductor chips 1 transferred to the first transfer substrate 4a; a second transfer step of transferring only the semiconductor chips 1 determined to be normal in the inspection step from the first transfer substrate 4a to the second transfer substrate 4b; and a mounting step of mounting the semiconductor chips 1 transferred to the second transfer substrate 4b on a circuit substrate 6.

Description

Installation method, installation device, and transfer device

The present invention relates to a transfer device, a mounting method, and a mounting device for stably mounting semiconductor chips with high precision.

Semiconductor chips are being miniaturized to reduce costs, and methods are being developed to mount these miniaturized chips with high precision. In particular, for LEDs (Light Emitting Diodes) used in displays, the industry requires semiconductor chips under 50um x 50um, known as micro-LEDs, to be mounted at high speeds with a precision of a few microns.

Patent Document 1 describes a component transfer method that uses a galvanometer mirror to reflect a laser beam generated by a laser light source and selectively irradiate a plurality of components arranged on a transfer source substrate. The components, removed from the transfer source substrate by the irradiation, are then transferred to a transfer target substrate. This transfer method enables high-speed transfer of microscopic components onto the transfer target substrate, and also enables high-speed mounting of components on circuit boards.

Prior Art Literature Patent Literature

Patent Document 1: Japanese Patent Publication No. 2006-41500

However, the mounting method using only the transfer method described in Patent Document 1 carries the risk of requiring significant time for post-mount repairs. Specifically, after verifying the proper mounting of the semiconductor chip on the circuit board through a lighting inspection, any defective semiconductor chips must be removed and replaced with healthy ones (repair). For example, in the case of a circuit board used in a 4K TV, 24.88 million semiconductor chips are used. Even with a 0.1% defect rate, approximately 25,000 chips would require repairs. This repair alone could take hundreds of hours, and even if the mounting process itself were completed quickly, there is the risk that repairs could significantly impact productivity.

In view of the above-mentioned problems, the object of the present invention is to provide a mounting method and mounting device for mounting a semiconductor chip on a circuit substrate with high productivity.

To address the aforementioned issues, the mounting method of the present invention is characterized by comprising: a first transfer step of transferring a plurality of semiconductor chips formed on a carrier substrate to a first transfer substrate; an inspection step of inspecting the condition of the semiconductor chips transferred to the first transfer substrate; a second transfer step of transferring only the semiconductor chips determined to be normal in the inspection step from the first transfer substrate to a second transfer substrate; and a mounting step of mounting the semiconductor chips transferred to the second transfer substrate on a circuit board.

In the mounting method of the present invention, only semiconductor chips that have been determined to be normal in the inspection step are transferred from the first transfer substrate to the second transfer substrate in the second transfer step. This significantly reduces the number of semiconductor chips requiring repair after mounting, thereby improving circuit board productivity.

Furthermore, the mounting step may include a pressing step of pressing the semiconductor chip together with the second transfer substrate onto the circuit board, and a separation step of separating the second transfer substrate from the semiconductor chip. The semiconductor chip is selectively transferred during the second transfer step by arranging the semiconductor chip on the second transfer substrate, which is about to be subjected to the pressing step, at a position corresponding to the position at which the semiconductor chip is to be arranged on the circuit board.

This allows multiple semiconductor chips to be mounted on a circuit board at the same time.

Alternatively, the first transfer step and the second transfer step may be performed by laser lift, wherein the spacing between semiconductor chips transferred to the first transfer substrate in the first transfer step, i.e., the first element spacing, is smaller than the spacing between semiconductor chips transferred to the second transfer substrate in the second transfer step, i.e., the second element spacing, and the oscillation frequency of the laser light in the first transfer step is higher than the oscillation frequency of the laser light in the second transfer step.

By setting the spacing between the semiconductor chips on the substrate relatively small during the first transfer step before the second transfer step, the laser beam can be emitted at a relatively high oscillation frequency while the components are transferred. This allows the transfer of the semiconductor chips to the circuit board to be completed in a short time.

Furthermore, the oscillation frequency of the laser light can be controlled by a laser light source that emits the laser light, and the optical path of the laser light can be controlled by an optical path control unit. When the optical path control unit is operated so that the movement speed of the laser light irradiation point on the first transfer substrate is approximately the maximum speed controllable by the optical path control unit, the oscillation frequency of the laser light in the second transfer step can be an oscillation frequency at which each laser light emitted from the laser light source can transfer the semiconductor chip at the second element interval.

This allows the semiconductor chip to be transferred in the shortest possible time during the second transfer step.

In addition, the optical path of the laser light can be controlled by a galvanometer mirror.

This allows for a simple optical path.

Furthermore, the mounting method of the present invention may include a post-mounting inspection step for inspecting the performance of the semiconductor chip mounted on the circuit substrate; and a repair step for adding or replacing a repair semiconductor chip, which replaces the semiconductor chip determined to be abnormal in the post-mounting inspection step, with the circuit substrate. In the repair step, the semiconductor chips are selectively transferred from the first transfer substrate to the second transfer substrate in such a manner that the semiconductor chips are arranged corresponding to the positions of the repair semiconductor chips on the circuit substrate. The semiconductor chips and the second transfer substrate are then press-bonded to the circuit substrate, and the second transfer substrate is separated from the semiconductor chips.

This can shorten the time required for repair.

Furthermore, in the inspection step, the condition of the semiconductor chip on the first transfer substrate can be inspected by visual inspection based on image analysis.

This allows the inspection process to be completed in a short time.

Furthermore, in the inspection step, the state of the semiconductor chip on the first transfer substrate can be inspected by photoluminescence.

This allows for inspection of specific components without connecting the semiconductor chip to the wires.

Furthermore, a chip removal step may be included between the inspection step and the second transfer step, wherein the chip removal step is to remove the semiconductor chip determined to be abnormal from the first transfer substrate.

This prevents abnormal chips from being mistakenly transferred to the second transfer substrate.

To address the aforementioned issues, the mounting device of the present invention is characterized by comprising: a transfer unit that transfers a plurality of semiconductor chips from a carrier substrate to a first transfer substrate and then transfers the semiconductor chips from the first transfer substrate to a second transfer substrate; an inspection unit that inspects the condition of the semiconductor chips transferred to the first transfer substrate; and a mounting unit that mounts the semiconductor chips transferred to the second transfer substrate on a circuit board. Only semiconductor chips that have been determined to be normal by the inspection unit are transferred from the first transfer substrate to the second transfer substrate.

In the mounting device of the present invention, only semiconductor chips that have been inspected by the inspection unit and are deemed normal are transferred from the first transfer substrate to the second transfer substrate. This significantly reduces the number of semiconductor chips requiring repair after mounting, thereby improving circuit board productivity.

Furthermore, in order to solve the above-mentioned problem, the transfer device of the present invention is characterized in that it comprises: a laser light source, which emits laser light, and the oscillation frequency of the laser light is controllable; and an optical path control unit, which controls the optical path of the laser light; and the transfer device controls the irradiation position of the laser light on the transfer substrate by the optical path control unit, and transfers any of the plurality of elements held by the transfer substrate to the transferred substrate by laser lifting; and the transfer device has: a first transfer mode, which uses the first substrate as the transferred substrate to transfer the element to the first substrate; substrate; and a second transfer mode, wherein the first substrate serves as the transfer substrate and the second substrate serves as the transferred substrate, and the components held by the first substrate are transferred to the second substrate; the spacing between the components transferred to the first substrate by the first transfer mode, i.e., a first component spacing, is smaller than the spacing between the components transferred to the second substrate by the second transfer mode, i.e., a second component spacing; and the oscillation frequency of the laser light in the first transfer mode is higher than the oscillation frequency of the laser light in the second transfer mode.

This transfer device sets the spacing between components on the substrate relatively small during the first transfer mode before the second transfer mode. This allows the transfer of components to the circuit board to be completed in a short time while emitting laser light at a relatively high oscillation frequency.

Furthermore, the second substrate may be a circuit substrate having a wiring circuit formed thereon.

This allows components to be transferred to the circuit board in a shorter time because the components are transferred to the circuit board with relatively small spacing before being transferred to the circuit board.

Furthermore, when the optical path control unit is operated so that the speed of movement of the laser beam irradiation position relative to the first substrate is approximately the maximum speed controllable by the optical path control unit, the oscillation frequency of the laser beam in the second transfer mode may be an oscillation frequency at which each laser beam emitted from the laser light source can cause the device to be transferred at intervals with the second device.

This allows components to be transferred in the shortest possible time even in the second transfer mode.

Furthermore, the optical path control unit may be a galvanometer mirror.

This allows the light path control unit to be formed with a simple structure.

Furthermore, the first element spacing may be equal to the spacing between the elements on the substrate on which the elements are grown, i.e., the growth substrate.

This minimizes the spacing between components in the first transfer mode, allowing the laser light oscillation frequency in the first transfer mode to be set higher.

Furthermore, the transfer device of the present invention may further include a performance determination mode for determining the operating performance of each of the components. In the first transfer mode, only components determined to be normal in the performance determination mode are transferred to the first substrate.

This allows for faster transfer times compared to the second transfer mode, which only separates normal components before transferring them.

The mounting method, mounting device, and transfer device of the present invention can be used to mount semiconductor chips on circuit boards with high productivity.

1: Semiconductor chip (component)

2: Carrier substrate

3a: Adhesive layer

3b: Adhesive layer

4a: First transfer substrate

4b: Second transfer substrate

5: Jointing materials

6: Circuit board

10: Transfer Section

11: Laser Light

11a: Laser light

11b: Laser light

11c: Laser light

11d: Laser light

12: Laser irradiation unit

13: Transfer substrate holding portion

14: Transfer substrate holding portion

15: Galvanometer

16:fθ lens

20: Inspection Department (Wavelength Measurement Department)

21: Camera

22: Inspected substrate holding unit

23: Laser Light Source

24: Wavelength Meter

30: Installation Department

31: Loading platform

32: Head

33: Dual-view optical system

34: Heater

35: Heater

40:Manipulator

41: Light up the inspection device

100: Installation Device

d1: 1st element spacing

d2: 2nd element spacing

f1: Oscillation frequency

f2: Oscillation frequency

L1: Laser light

L2: Laser Light

L3: Emitting light

v1: Scanning speed

v2: Scanning speed

w0: substrate

w1: 1st substrate

w2: 2nd substrate

Figure 1 illustrates the installation of the present invention.

Figure 2 illustrates the transfer section of the mounting device of the present invention.

Figure 3 illustrates the inspection section of the mounting device of the present invention.

Figure 4 illustrates the mounting portion of the mounting device of the present invention.

Figures 5(a) to (c) illustrate the first transfer step of the installation method of the present invention.

Figures 6(a) and (b) illustrate the inspection step and chip removal step of the mounting method of the present invention.

Figure 7 is a diagram illustrating a transfer device according to another embodiment of the present invention.

Figure 8 shows the wavelength distribution of light emitted by the elements on the transfer substrate, obtained by the wavelength measuring unit of the transfer device, and the grouping results performed by the control device.

Figures 9(a) to (c) illustrate the second transfer step of the installation method of the present invention.

Figures 10(a) to (c) illustrate the installation steps of the installation method of the present invention.

Figures 11(a) to (d) illustrate the general lighting inspection and repair steps.

Figure 12 illustrates the repair steps of the present invention.

Figure 13 shows the first transfer step in another embodiment of the present invention.

Figure 14 shows the second transfer step in another embodiment of the present invention.

Figure 15 shows the relationship between the scanning speed of the optical path control unit and the oscillation frequency of the laser beam.

Figure 1 shows the installation device for implementing the installation method of the present invention.

The mounting device 100 includes a transfer unit 10, an inspection unit 20, and a mounting unit 30. The transfer unit 10 performs the first and second transfer steps, while the mounting unit 30 performs the mounting step. Furthermore, the inspection unit 20 inspects the semiconductor wafer between the first and second transfer steps. Furthermore, the substrates (carrier substrate 2, first transfer substrate 4a, second transfer substrate 4b, circuit board 6) are transported between the various devices by one or more robots 40.

Figure 2 shows the details of the transfer unit 10.

The transfer unit 10 includes a laser irradiation unit 12 that irradiates the laser beam 11; a transfer substrate holder 13 that holds the transfer substrate and is movable in at least the X-axis and Y-axis directions; a transferred substrate holder 14 located below the transfer substrate holder 13 and holding the transferred substrate opposite the transfer substrate with a gap therebetween; and a control unit (not shown).

The laser irradiation unit 12, also known as a laser light source, is a device that emits laser light 11 at a specific oscillation frequency, such as an excimer laser, a YAG (Yttrium-Aluminum-Garnet) laser, or a visible light laser. It is fixed to the transfer unit 10. In this embodiment, the laser irradiation unit 12 emits a point-shaped laser beam 11. The laser beam 11 is controlled in its X-axis and Y-axis directions by a galvanometer mirror 15 and an fθ lens 16, whose angles are adjusted by a control unit. The laser beam 11 selectively irradiates the semiconductor chips 1, a plurality of which are arranged on a transfer substrate held by a transfer substrate holder 13. When the laser light 11 is incident on the semiconductor chip 1 on the transfer substrate, laser lift-off is generated, thereby transferring the semiconductor chip 1 from the transfer substrate to the transferred substrate.

Here, the oscillation frequency in this description refers to the number of times a specific light output is repeated in one second. For example, at an oscillation frequency of 1 kHz, the specific light output is repeated 1000 times in one second. The higher the oscillation frequency, the shorter the interval between light outputs.

Furthermore, in this description, the transfer section 10 performs the following first and second transfer steps. In the first transfer step, the carrier substrate 2 serves as the transfer substrate, and the first transfer substrate 4a serves as the substrate to be transferred. Meanwhile, in the second transfer step, the first transfer substrate 4a serves as the transfer substrate, and the second transfer substrate 4b serves as the substrate to be transferred.

The transfer substrate holder 13 has an opening that holds the transfer substrate near its outer periphery by suction. Laser light 11 emitted from the laser irradiation unit 12 is directed through the opening onto the transfer substrate held by the transfer substrate holder 13.

The transfer substrate holder 13 is movable relative to the target substrate holder 14 in at least the X-axis and Y-axis directions by a moving mechanism (not shown). A control unit controls the moving mechanism to adjust the position of the transfer substrate holder 13, thereby adjusting the relative position of the semiconductor wafer 1 held on the transfer substrate relative to the target substrate.

The substrate holder 14 has a flat top surface and holds the substrate during the transfer process. Multiple suction holes are provided on the top surface of the substrate holder 14 to maintain the back surface of the substrate (the side not receiving the semiconductor wafer 1) through suction.

Furthermore, in this embodiment, only the transfer substrate holder 13 moves in the X- and Y-axis directions, resulting in relative movement between the transfer substrate holder 13 and the target substrate holder 14. However, if the target substrate is large and its entire surface cannot be positioned directly below the irradiation range of the laser beam 11, the target substrate holder 14 may also be provided with a mechanism for movement in the X- and Y-axis directions.

Next, Figure 3 shows the details of the inspection unit 20.

The inspection unit 20 includes a camera 21, an inspected substrate holder 22, and a control unit (not shown). The camera 21 captures an inspection target held by the inspected substrate holder 22 and visually inspects the semiconductor wafer 1 through image analysis. In this embodiment, the inspection target is a plurality of semiconductor wafers 1 transferred to a first transfer substrate 4a.

Some semiconductor chips 1 on the first transfer substrate 4a may have substandard performance during formation on the carrier substrate 2 or may have cracks during transfer to the first transfer substrate 4a. By checking the color or shape of the semiconductor chip 1, it is possible to more accurately determine whether the performance of the semiconductor chip 1 is normal.

In this embodiment, the camera 21 is, for example, a complementary metal oxide semiconductor (CMOS) camera. It has an imaging element and, triggered by external signals, converts light formed on the imaging element into electrical signals to produce digital images. The camera 21 is oriented directly downward, capturing the semiconductor chip 1 from above. Furthermore, the camera 21 is mounted on a moving device (not shown) and is driven by a control unit, thereby moving the camera 21 in the X-axis and Y-axis directions.

The inspection unit 20 also includes an illumination unit (not shown). In this embodiment, the illumination unit is an LED that emits light in synchronization with the movement of the camera 21, which is achieved by a moving device. The camera 21 captures images while the illumination unit is emitting light, continuously capturing the appearance of a plurality of semiconductor chips 1 arranged in the X-axis and Y-axis directions.

Next, Figure 4 shows the details of the mounting portion 30.

The mounting unit 30 includes a mounting platform 31, a head 32, a dual-view optical system 33, and a control unit (not shown).

The mounting table 31 can mount the circuit board 6 and hold it so that it does not move due to vacuum suction. It is also configured to move the circuit board 6 in the X and Y axis directions via an XY stage.

In this embodiment, the mounting table 31 includes a heater 34, which allows the control unit to control the surface temperature of the mounting table 31 (i.e., the temperature of the circuit board 6 mounted on the mounting table 31). Furthermore, a thermometer (not shown) is provided on the mounting table 31, which uses the temperature of the mounting table 31 measured by the thermometer as feedback for temperature control.

The head 32 has a generally flat front end with one or more suction holes. During the mounting process, it suction-holds the side of the second transfer substrate 4b to which the semiconductor chip 1 is not transferred. Furthermore, the head 32 is movable in the Z-axis direction, bringing the circuit board 6 held on the mounting table 31 into contact with and applying pressure to the bumps of the semiconductor chip 1 transferred to the second transfer substrate 4b held by the head 32. The head 32 also includes a heater 35, which allows the temperature of the head 32, particularly the front end, to be controlled by the control unit. Furthermore, a thermometer (not shown) is provided on the head 32 to provide feedback on the temperature of the head 32 for temperature control.

Furthermore, the head 32 is configured to move in the θ direction (the direction of rotation about the Z axis). By linking the movement of the mounting table 31 in the X and Y axes with the movement of the head 32 in the Z and θ directions, the semiconductor chip 1 can be thermally pressed and mounted at a specific position on the circuit board 6.

In this embodiment, heaters 34 and 35 are controlled simultaneously to ensure that the surface temperature of mounting table 31 and the temperature of the tip of head 32 (≒the temperature of second transfer substrate 4b) are always equal during the mounting step. As described above, even if thermal expansion occurs between circuit board 6 and second transfer substrate 4b during the mounting step, the relative position of the portion of second transfer substrate 4b contacting semiconductor chip 1 and the portion of circuit board 6 where bumps of semiconductor chip 1 are bonded is unlikely to change, enabling stable and high-precision mounting.

Furthermore, in this embodiment, the head 32 moves in the Z-axis and θ directions, while the stage 31 moves in the X-axis and Y-axis directions. However, this is not necessarily limited to this configuration and can be modified appropriately depending on the device. For example, a configuration can be employed in which the head 32 moves in the X-axis, Y-axis, and θ directions, while the stage 31 moves in the Z-axis direction. Furthermore, the θ-direction movement mechanism can be omitted if not required. For example, if there is no rotational deviation between the positions of the semiconductor chip 1 and the circuit board 6, the θ-direction movement mechanism can be omitted.

When a circuit board 6 is placed on the mounting table 31, the dual-view optical system 33 enters the space between the head unit 32 and the circuit board 6 to capture images of both. Each captured image undergoes image processing in the control unit to identify positional deviations. The control unit then controls the placement of each semiconductor chip 1, taking these deviations into account, so that each semiconductor chip 1 contacts and bonds with a specific location on the circuit board 6. This allows for high-precision mounting of the semiconductor chips 1 in the X and Y directions.

Next, the mounting method of the present invention will be described with reference to Figures 5 to 10. Figure 5 illustrates the first transfer step of the mounting method of the present invention. Figure 6 illustrates the inspection step and the chip removal step of the mounting method of the present invention. Figure 9 illustrates the second transfer step of the mounting method of the present invention. Figure 10 illustrates the mounting steps in another embodiment.

Furthermore, in the present invention, of the two main surfaces of the semiconductor chip, the surface held by the carrier substrate is defined as the first surface, and the surface opposite the first surface is defined as the second surface. Bumps are formed on the second surface, and the bumps are bonded to the circuit board.

First, referring to FIG5 , the first transfer step of the installation method of the present invention, performed in the transfer unit 10 shown in FIG2 , will be described. Furthermore, in this description, the transfer unit 10 performing the first transfer step will be referred to as the first transfer mode, and the transfer unit 10 performing the second transfer step described below will be referred to as the second transfer mode.

Figure 5(a) shows a plurality of semiconductor chips 1, whose first surface is held on a carrier substrate 2 after slicing. The carrier substrate 2 also expands in the depth direction of Figure 5 and has a circular or rectangular shape. It is made of silicon, gallium arsenide, sapphire, etc. Furthermore, a plurality of semiconductor chips 1 (hundreds to tens of thousands) are arranged two-dimensionally along the expansion of the carrier substrate 2. Small semiconductor chips 1, known as micro-LEDs, have a size of 50 μm x 50 μm or less. These small semiconductor chips 1 are arranged at a pitch obtained by adding the slicing width to this size. These small semiconductor chips 1 are required to be mounted on the circuit substrate 6 with high precision (for example, an accuracy of less than 1 μm). Bumps are also formed on the second surface of the semiconductor chip 1.

Figure 5(b) shows the first transfer substrate attaching step, in which the second surface of the semiconductor chip 1, which is opposite to the first surface held by the carrier substrate 2, is attached to the first transfer substrate 4a. The first transfer substrate 4a is first held by the transfer substrate unit 14 using vacuum suction, and an adhesive layer 3a is formed on the surface to which the semiconductor chip 1 is attached. In this first transfer substrate attaching step, a robot 40 suctions the carrier substrate 2 holding the semiconductor chip 1, attaching the second surface of the semiconductor chip 1 to the adhesive layer 3a of the first transfer substrate 4a held by the transfer substrate unit 14, as shown in Figure 2.

Next, the carrier substrate removal step is performed on the first transfer substrate 4a to which the semiconductor chip 1 and carrier substrate 2 are attached as described above. In this carrier substrate removal step, the carrier substrate 2 is separated and removed from the semiconductor chip 1 by laser lift. Specifically, laser light 11a emitted from the laser irradiation unit 12 shown in Figure 2 is transmitted through the carrier substrate 2 and irradiated onto the first surface of the semiconductor chip 1. This decomposes a portion of the GaN layer of the micro-LEDs on the semiconductor chip 1 into Ga and N, thereby separating the semiconductor chip 1 from the carrier substrate 2 comprising sapphire. The carrier substrate 2, with all semiconductor chips 1 irradiated by the laser light 11a, is then separated from the first transfer substrate 4a by the robot 40, which vacuum-holds the carrier substrate 2 and removes it.

After the first transfer substrate attaching step and the carrier substrate removing step, as shown in Figure 5(c), the semiconductor chip 1 is transferred from the carrier substrate 2 to the first transfer substrate 4a. In this description, the step of transferring the semiconductor chip 1 from the carrier substrate 2 to the first transfer substrate 4a is referred to as the first transfer step.

Furthermore, in the above description, the carrier substrate 2 is removed after the second surface of the semiconductor chip 1 is attached to the first transfer substrate 4a in the first transfer step. However, this is not limiting. Alternatively, with the first transfer substrate 4a positioned slightly away from the second surface of the semiconductor chip 1, the propulsion force generated by the partial decomposition of the GaN layer of the micro-LED into Ga and N when the carrier substrate 2 is irradiated with laser light can energize the semiconductor chip 1, causing it to fly from the carrier substrate 2 toward the first transfer substrate 4a and adhere to the first transfer substrate 4a.

Furthermore, in this embodiment, the carrier substrate 2 is peeled from the semiconductor chip 1 by laser lift, thereby transferring the semiconductor chip 1 from the carrier substrate 2 to the first transfer substrate 4a. However, this is not necessarily limited to this method and can be modified as appropriate. For example, the carrier substrate 2 can also be removed by scraping away from the side opposite to the side on which the semiconductor chip 1 is provided. This method is called back grinding, and is particularly useful for red LEDs, where laser lift cannot be applied.

Next, the inspection step shown in Figure 6(a) is performed in the inspection unit 20 shown in Figure 3. During this inspection step, a camera 21 moves and captures images of hundreds to tens of thousands of semiconductor chips 1 arranged along the X and Y axes on the first transfer substrate 4a held by suction on the substrate holder to be inspected. The control unit of the inspection unit 20 analyzes the images obtained by this capture and inspects each semiconductor chip 1 for appearances such as color and shape. If the first transfer substrate 4a is a 6-inch wafer, the inspection step for each first transfer substrate 4a takes approximately 30 minutes.

Here, Figure 7 is used to illustrate the transfer device, particularly the inspection unit, in another embodiment of the present invention.

As shown in FIG7 , the transfer device 1 in this embodiment includes a wavelength measuring unit 20 as an inspection unit 20 . The wavelength measuring unit 20 measures the light emission characteristics (e.g., light emission wavelength) of each element 1 as a light-emitting element and reflects the measurement results on the transfer of the element 1 in the transfer unit 10 .

In this embodiment, the wavelength measuring unit 20 uses photoluminescence to measure the wavelength of light emitted by each component 1 on the first transfer substrate 4a. It includes a laser light source 23, a wavelength measuring device 24, and an inspected substrate holding unit 22.

Within the wavelength measurement unit 20, the first transfer substrate 4a, serving as the substrate to be inspected, is held horizontally and facing upward by the substrate holder 22 by suction, with the back surface thereof held.

The laser light source 23 is a device that emits a beam of laser light L2. In this embodiment, it emits laser light such as YAG laser or visible light laser.

The wavelength measuring device 24 measures the wavelength of the light incident on the device and can be a conventional optical wavelength meter.

When laser light L2 strikes a device 1 at a specific location on the first transfer substrate 4a, electrons within the device 1 are excited. When these electrons return to their base state, they emit light L3 (so-called photoluminescence). This light L3 is captured by a wavelength detector 24, which measures its wavelength. This allows the wavelength of light emitted by a specific device 1 to be measured without wiring the device 1.

Furthermore, the inspected substrate holder 22 is movable in the X- and Y-axis directions via a movable stage, allowing the first transfer substrate 4a to move relative to the laser light source 23 and wavelength measurement device 24 in the X- and Y-axis directions. By controlling the position of the first transfer substrate 4a using the movable stage, the emission wavelength of the component 1 held at any position on the first transfer substrate 4a can be measured. The wavelength measurement unit 20 measures the emission wavelength of all components 1 held on the first transfer substrate 4a.

Figure 8 is a graph showing the distribution of the emission wavelengths of the elements 1 on the first transfer substrate 4a, obtained by the wavelength measuring unit 20. The horizontal axis represents the emission wavelength, and the vertical axis represents the number of elements 1 emitting at each wavelength (number of elements).

Even when epitaxially grown on the same growth substrate, components 1 of the same color will have slightly different emission wavelengths, resulting in a distribution similar to the normal distribution shown in Figure 8.

In this embodiment, the control device divides the distribution into two groups: Group A, which includes a specific wavelength range of the majority (mode value) emission wavelength, and Group B, which is located outside Group A (a group with a significant difference between the emission wavelength and the mode value).

Specifically, in this embodiment, regarding the emission wavelengths that form the boundary between Group A and Group B in Figure 8 , for example, the emission wavelength range of 600nm to 780nm for red LEDs is designated as Group A, the emission wavelength range of 505nm to 530nm for green LEDs is designated as Group A, and the emission wavelength range of 470nm to 485nm for blue LEDs is designated as Group A. The range outside these ranges is designated as Group B.

Based on the measurement results of the emission wavelength of each component 1, the control device determines that components 1 in the Group B range whose emission wavelength deviates from the model value do not meet performance requirements. Furthermore, in the transfer section 10, only components 1 with normal performance, i.e., components 1 from Group A, are transferred from the first transfer substrate 4a to the second transfer substrate 4b, without using components 1 from Group B during transfer to the second transfer substrate 4b.

In this description, the wavelength measurement unit 20 measuring the emission wavelength of each element 1 as described above is referred to as the wavelength measurement mode. Furthermore, the control device determining whether the operating performance of each element 1 falls within the normal range, such as group A, or falls within the substandard range, such as group B, is referred to as the performance determination mode.

By incorporating these performance evaluation and wavelength measurement modes into the transfer process of component 1, the finished display will exhibit no uneven luminescence.

Furthermore, in this embodiment, the performance determination mode is executed before the first transfer mode. In the first transfer mode, only components 1 that were determined to be normal in the performance determination mode are transferred to the second transfer substrate 4b.

Returning to the description of Figure 6 , in this embodiment, the wafer removal step shown in Figure 6(b) is performed after the inspection step. In this wafer removal step, semiconductor wafers 1 determined to be abnormal in the inspection step (the two semiconductor wafers 1 indicated by dots in Figure 6(b)) are irradiated with laser light 11b, thereby ablating the semiconductor wafers 1 and removing them from the first transfer substrate 4a.

This chip removal step can also be performed by the transfer unit 10. At this time, the laser light 11b is emitted from the laser irradiation unit 12 at a higher power than the laser light 11a in the first transfer step because it is necessary to burn the semiconductor chip 1.

In this way, by removing the abnormal semiconductor chip 1 during the chip removal step, it is possible to prevent the abnormal semiconductor chip 1 from being mistakenly transferred in subsequent steps.

Next, the second transfer step shown in Figures 9(a) to (c) is performed in the transfer section 10 shown in Figure 2. In the second transfer step, as shown in Figure 9(a), the first transfer substrate 4a is held by the transfer substrate holder 13 (not shown) with the adhesive layer 3a and the semiconductor chip 1 facing downward. Furthermore, the second transfer substrate 4b having the adhesive layer 3b is held by the transferred substrate holder 14 with the second transfer substrate 4b positioned below the first transfer substrate 4a.

The controller of the transfer unit 10 then adjusts the angle of the galvanometer mirror 15, allowing laser light 11c to pass through the first transfer substrate 4a and reach the interface between the adhesive layer 3a and the second surface of a specific semiconductor chip 1, thereby laser-lifting the semiconductor chip 1. Specifically, the laser light 11 generates gas from the adhesive layer 3a by irradiation. This gas energizes the semiconductor chip 1, causing it to fly downward from the first transfer substrate 4a and adhere to the second transfer substrate 4b. The semiconductor chip 1 transferred to the second transfer substrate 4b in this manner faces its first surface, with its bumps exposed.

Furthermore, in this second transfer step, rather than transferring all semiconductor chips 1 on the first transfer substrate 4a continuously, semiconductor chips 1 are selectively transferred, as shown in Figure 9(b). The arrangement of semiconductor chips 1 on the first transfer substrate 4a immediately after the first transfer step is identical to the arrangement of semiconductor chips 1 on the carrier substrate 2 before the first transfer step. However, by selectively transferring semiconductor chips 1 in this second transfer step, semiconductor chips 1 can be transferred to the second transfer substrate 4b in any desired arrangement.

Here, in this embodiment, in preparation for the following mounting step, the arrangement of the semiconductor chips 1 on the second transfer substrate 4b corresponds to the positions where the semiconductor chips 1 should be placed on the circuit board 6. More specifically, the semiconductor chips 1 are arranged on the second transfer substrate 4b in the following layout. This layout mirrors the layout of the semiconductor chips 1 within the area on the circuit board 6 where the semiconductor chips 1 can be mounted in a single mounting step.

On the other hand, there are cases where, as indicated by the dashed line on the second transfer substrate 4b in Figure 9(b), the semiconductor chip 1 that can be transferred to the intended position on the second transfer substrate 4b is not present on the first transfer substrate 4a. In this case, the first transfer substrate 4a and the second transfer substrate 4b can be moved relative to each other, as shown in Figure 9(c), followed by laser lift. Furthermore, AI (artificial intelligence) can be used to determine how to move the first transfer substrate 4a and the second transfer substrate 4b relative to each other in order to form a specific layout on the second transfer substrate 4b with the minimum number of moves.

Furthermore, the power of laser light 11c during laser lift-off from the first transfer substrate 4a is sufficient to decompose the adhesive layer 3a, and is lower than the power of laser light 11a used to decompose the GaN layer in the first transfer step. Therefore, the possibility of damage to the semiconductor chip 1 due to irradiation with laser light 11c in the second transfer step is lower than the possibility of damage to the semiconductor chip 1 due to irradiation with laser light 11a in the first transfer step and can be ignored.

Next, the mounting steps shown in Figures 10(a) to (c) are performed in the mounting section 30 shown in Figure 4. During the mounting steps, as shown in Figure 10(a), the head section 32 shown in Figure 4 holds the side of the second transfer substrate 4b on which the semiconductor chip 1 has not been transferred, so that the circuit board 6, which is placed on the mounting table 31 described below, faces the semiconductor chip 1 held by the second transfer substrate 4b.

Then, the head 32 approaches the circuit board 6, as shown in Figure 10(b), causing the bumps provided on the second surface of the semiconductor chip 1 to abut against the circuit board 6, and then applying pressure.

Furthermore, in this embodiment, a bonding material 5 such as an ACF (anisotropic conductive film) is provided on the surface of the circuit board 6 with which the semiconductor chip 1 contacts. After the semiconductor chip 1 contacts the bonding material 5, the bonding material 5 holds the semiconductor chip 1.

Furthermore, a heater 35 is provided in the head portion 32. When the semiconductor chip 1 is pressurized, the heater 35 is activated to heat the semiconductor chip 1 to a relatively low temperature of below 50°C. This raises the temperature of the bonding material 5 through the semiconductor chip 1, thereby increasing the adhesion of the bonding material 5 around the bumps of the semiconductor chip 1. As a result, the semiconductor chip 1 is thermally pressed to a degree where it does not deviate from the position relative to the wiring of the circuit board 6. In other words, the semiconductor chip 1 is temporarily pressed to the circuit board 6. Furthermore, if the semiconductor chip 1 can be fixed to a degree where it does not deviate from the position relative to the wiring of the circuit board 6 by simply embedding the bumps of the semiconductor chip 1 in the bonding material 5, then it is not necessary to heat the semiconductor chip 1 during the temporary pressing. Furthermore, in this description, the step of press-bonding the semiconductor chip 1 together with the second transfer substrate 4b to the circuit board 6 is referred to as the press-bonding step.

Then, while retaining the second transfer substrate 4b, the head 32 moves away from the circuit board 6, thereby separating the second transfer substrate 4b from the semiconductor chip 1. In this description, this step of separating the second transfer substrate 4b from the semiconductor chip 1 is referred to as the separation step. In this separation step, if the adhesive layer 3b's adhesion to the semiconductor chip 1 is weaker than the bonding between the semiconductor chip 1 and the circuit board 6, the second transfer substrate 4b can be separated from the semiconductor chip 1 simply by moving the second transfer substrate 4b away from the circuit board 6. After this separation step, although not shown, semiconductor chip 1 is pressed and bonded to circuit board 6, a process known as final pressing. Simultaneously, semiconductor chip 1 is heated to a temperature higher than the temperature used during the temporary pressing (approximately 150°C). This melts the bumps on semiconductor chip 1. After cooling, semiconductor chip 1 is mounted to a specific position on circuit board 6 with a strong bonding force. This final pressing completes the sequential mounting method of the present invention.

Furthermore, in this embodiment, as shown in Figure 10(b), multiple semiconductor chips 1 are simultaneously pressed and bonded in a single mounting step. Especially when the semiconductor chips 1 are micro-LEDs, tens of thousands of semiconductor chips 1 can be mounted on a single circuit board 6. In this case, for example, in a 4K TV panel, 3840×2160×3 semiconductor chips 1 are arranged on a single panel. By collectively transferring multiple semiconductor chips 1 to a single second transfer substrate 4b and performing simultaneous press bonding while holding the second transfer substrate 4b with the head 32, mounting time can be significantly reduced. Specifically, the number of semiconductor chips 1 transferred to the second transfer substrate 4b at a time can be 80×80, 120×120, or the like.

Here, in this embodiment, as described above, the pressing step prior to the separation step is limited to temporarily pressing the semiconductor chip 1 to the circuit substrate 6, and then performing the formal pressing. However, instead of this, the semiconductor chip 1 can be formally pressed to the circuit substrate 6 during the pressing step. In this case, the sequential mounting method of the present invention is completed at the time the separation step is completed. In this case, the thermal expansion coefficient of at least the surface of the head 32 that contacts the second transfer substrate 4b (the front end of the head 32), the thermal expansion coefficient of the second transfer substrate 4b, and the thermal expansion coefficient of the surface of the circuit substrate 6 on which the semiconductor chip 1 is mounted are preferably equal. Furthermore, it is further preferred that the front end of the head 32, the second transfer substrate 4b, and the surface of the circuit board 6 on which the semiconductor chip 1 is mounted be made of the same material. Specifically, if the circuit board 6 is made of glass, the front end of the head 32 and the second transfer substrate 4b should be made of the same glass. Furthermore, if the circuit board 6 is made of copper, the front end of the head 32 and the second transfer substrate 4b should be made of SUS304. In this case, the thermal expansion coefficient of copper is 16.8 ppm, while the thermal expansion coefficient of SUS304 is 17.3 ppm, a difference of approximately 3%.

Furthermore, a heater is installed not only in the head 32 but also in the mounting table 31. During the thermal pressing step, heaters 34 and 35 are controlled to maintain the temperature of the head 32 and second transfer substrate 4b at the same level as the surface of the circuit board 6 on which the semiconductor chip 1 is mounted. This ensures that even if thermal expansion of the circuit board 6, head 32, and second transfer substrate 4b occurs during the mounting step, the relative position of the portion of the second transfer substrate 4b in contact with the semiconductor chip 1 and the portion of the circuit board 6 where the bumps of the semiconductor chip 1 are bonded are unlikely to change, enabling stable and high-precision mounting.

Figure 11 illustrates the lighting inspection and repair steps.

In the case where the semiconductor chips 1 are micro-LEDs, to confirm the luminous performance of the semiconductor chips 1 mounted on the circuit board 6, as shown in Figure 11(a), the circuit board 6 is placed on a lighting inspection device 41, and all semiconductor chips 1 are illuminated to inspect their luminous performance. In the present invention, this step of inspecting the performance of the semiconductor chips 1 mounted on the circuit board 6 is referred to as a post-mounting inspection step.

If the post-installation inspection step (lighting inspection) shows that the semiconductor chip 1 is not lit, as in the second semiconductor chip 1 from the right in Figure 11(a), or if a semiconductor chip 1 exhibits low brightness, the semiconductor chip 1 is irradiated with laser light 11d to be ablated, as shown in Figure 11(b). The power of this laser light 11d can be equivalent to the power of laser light 11b used in the chip removal step shown in Figure 6(b), and this step can also be performed by the transfer unit 10. Furthermore, even if a semiconductor chip 1 exhibits abnormal performance, it can be retained without ablation if a new semiconductor chip 1 is positioned near it.

When the semiconductor chip 1 is burned off in this manner, the bonding material 5 may sometimes be burned off. In this case, bonding material 5 is applied as shown in Figure 11(c). Then, as shown in Figure 11(d), a new semiconductor chip 1, or a repair semiconductor chip, is installed in the area where the semiconductor chip 1 was burned off to replace the semiconductor chip 1 with abnormal performance.

In this invention, the step of installing the repair semiconductor chip is referred to as the repair step. The time required for one repair is approximately 30 seconds.

Here, when the circuit board 6 is used in a 4K TV, for example, 24.88 million semiconductor chips 1 are used. If the defect rate of these semiconductor chips 1 is 0.1%, approximately 25,000 of them need to be repaired. If each repair semiconductor chip is repaired individually, the repair alone would take approximately 200 hours. Even if laser lifting is used to speed up the assembly process, the repair process would still significantly impact productivity.

In contrast, the mounting method of the present invention includes an inspection step. Furthermore, only semiconductor chips 1 determined to be normal by this inspection step, i.e., semiconductor chips 1 with a 100% yield during the inspection step, are placed on the second transfer substrate 4b and mounted on the circuit board 6. As a result, compared to mounting without the inspection step, the number of chips with lighting failures during the lighting inspection is significantly reduced, significantly reducing the number of semiconductor chips 1 requiring repair after mounting, thereby improving the productivity of the circuit board 6.

If, in the aforementioned 4K TV example, the defective lighting rate is reduced to 1% by implementing an inspection step, the repair time is reduced to approximately 2 hours, a reduction of nearly 200 hours. While the present invention's installation method includes an additional inspection step compared to previous installation methods, the time required for this inspection step is approximately 30 minutes. Therefore, using the present invention's installation method significantly reduces this time, enabling the production of a circuit board 6 with a 100% normal lighting rate.

Furthermore, during further repair, the mounting method of the present invention is further utilized. As shown in FIG12 , the semiconductor chip 1 is selectively transferred from the first transfer substrate 4a to the second transfer substrate 4b corresponding to multiple repair locations on the circuit board 6. The second transfer substrate 4b is then used to simultaneously perform repairs at multiple locations, thereby further shortening the time required for repairs.

Next, the transfer step in another embodiment of the present invention will be described using Figures 13 and 14.

Figure 13 is a schematic diagram showing the first transfer mode.

In the first transfer mode, the substrate to be transferred is set as the first substrate w1, and the transfer unit 10 transfers the device 1 held on substrate w0 to the first substrate w1. Substrate w0 can be a growth substrate for epitaxial growth of device 1, or an intermediate substrate for transferring device 1 from substrate to substrate once or multiple times.

Here, the pitch of the components 1 transferred to the first substrate w1, i.e., the first component spacing d1, is smaller than the pitch of the components 1 transferred to the second substrate w2 using the second transfer mode described below, i.e., the second component spacing d2. Furthermore, the first component spacing d1 represents the pitch of the components 1 formed on the growth substrate at the end of wafer dicing. It is preferred that the components 1 be transferred from the growth substrate to the first substrate w1 while maintaining this spacing. For example, if a 20 μm × 40 μm component 1 is formed on the growth substrate with a spacing of 30 μm along its short side and 50 μm along its long side, it is preferred that this spacing be maintained while transferring the components 1 from the growth substrate to the first substrate w1.

In the first transfer mode, laser light source 12 emits laser light L1 at a specific oscillation frequency f1. The oscillation frequency f1 (Hz) and the scanning speed v1 (m/s) of galvanometer mirror 15 are set so that each emitted laser light L1 can laser-lift a specific component 1. For example, when laser-lifting components 1 arranged at a spacing d1 as shown in Figure 13, the oscillation frequency f1 and scanning speed v1 are set to satisfy the equation v1/f1=d1. Specifically, when the first component spacing d1 is 30 μm (0.03 mm), for example, if the oscillation frequency f1 is set to 166 kHz and the scanning speed v1 is set to 5 m/s, the transfer unit 10 can sequentially transfer components 1. On the other hand, if the oscillation frequency f1 is set to 10 kHz and the scanning speed v1 is set to 300 mm/s, the transfer unit 10 can also sequentially transfer components 1. However, the oscillation frequency f1 determines the number of components 1 that can be transferred within a given time period. Therefore, it is best to perform transfer at a higher oscillation frequency f1 as possible.

Figure 14 is a schematic diagram showing the second transfer mode.

In the second transfer mode, the first substrate w1, to which the component 1 has been transferred in the first transfer mode, serves as the transfer substrate, and the second substrate w2 serves as the transferred substrate. The transfer unit 10 transfers the component 1 held on the first substrate w1 to the second substrate w2.

In this embodiment, the second substrate w2 is a circuit substrate for a television display with a wiring circuit formed on its surface. By transferring the element 1 onto the wiring circuit, the element 1, which is an LED light-emitting element, can be illuminated.

In the second transfer mode, the transfer unit 10 transfers every few components 1 held on the first substrate w1. This adjusts the pitch of components 1 on the second substrate w2 to the second component spacing d2, the spacing required for components 1 to function on the circuit board, i.e., the spacing between wiring circuits on the circuit board. For example, the transfer unit 10 transfers every 20 components 1 arranged at the first component spacing d1 = 30 μm on the first substrate w1 to the second substrate w2. This adjusts the pitch of components 1 on the second substrate w2, i.e., the second component spacing d2, to 600 μm.

On the other hand, when transferring by increasing the pitch of the components 1 as in the second transfer mode, the oscillation frequency of the laser light L1 emitted by the laser light source 12 may be restricted.

Figure 15 shows the relationship between the scanning speed of the optical path control unit (galvanometer mirror 15) and the oscillation frequency of laser light L1. The solid line represents the case where the distance between the laser and the target (element 1) is 0.03 mm, and the dotted line represents the case where the distance is 0.60 mm.

In the transfer unit 10, the scanning speed of the galvanometer mirror 15 (optical path control unit) is limited. Assuming the maximum scanning speed is 5 m/s, the oscillation frequency of each pulsed laser beam L1 that can transfer components 1 arranged at a 0.03 mm pitch is approximately 166 kHz.

In contrast, when the pitch between components 1 is 0.60 mm, even at the highest scanning speed, the oscillation frequency of each pulsed laser beam L1 capable of transferring the laser beam L1 to the component 1 is limited to approximately 8.3 kHz. Even if the laser light source 12 can emit laser beam L1 at an oscillation frequency of 200 kHz, its performance is still not fully utilized, and the number of components 1 that can be transferred in a given period of time becomes relatively small.

Therefore, in the present invention, control is performed as follows: the oscillation frequency of the laser light source 12 is varied between the first transfer mode and the second transfer mode, so that the first element spacing d1 in the first transfer mode is smaller than the second element spacing d2 in the second transfer mode, and the oscillation frequency f1 in the first transfer mode is higher than the oscillation frequency f2 in the second transfer mode.

Specifically, in this embodiment, in the second transfer mode, the scanning speed v2 of the galvanometer mirror 15 is set to the maximum speed (approximately 5 m/s), and the oscillation frequency f2 is set to a frequency (approximately 8.3 kHz) that allows each laser beam L1 to transfer the component 1 at the second component spacing d2 (0.60 mm), which is equivalent to the pitch of the wiring circuit.

In contrast, in the first transfer mode, the scanning speed v1 of the galvanometer mirror 15 is equal to the scanning speed v2, set to the maximum speed (approximately 5 m/s). The oscillation frequency f1 is set to the frequency (approximately 166 kHz) that allows each laser beam L1 to transfer the component 1 at the first component spacing d1 (0.03 mm).

Therefore, considering the spacing of the wiring circuits, the second component spacing d2 becomes relatively large in the second transfer mode, resulting in a slower transfer speed. On the other hand, by setting the spacing between components on the substrate to be relatively small before the first transfer mode, a relatively high oscillation frequency can be set. Laser light is emitted while components are transferred, thus completing the transfer of components to the circuit board in a shorter time.

Furthermore, when the galvanometer mirror 15, serving as the optical path control unit, is operated at approximately the maximum speed controllable by the galvanometer mirror 15, the oscillation frequency f2 of the laser light L1 in the second transfer mode is the frequency at which each laser light L1 emitted by the laser light source 12 can transfer the component 1 at the second component interval d2. Consequently, even in the second transfer mode, the component 1 can be transferred in the shortest possible time.

Furthermore, by making the first element spacing d1 equal to the spacing between elements 1 on the growth substrate, the spacing between elements 1 in the first transfer mode can be minimized, allowing the oscillation frequency f1 of the laser light L1 in the first transfer mode to be set higher.

By using the above-described mounting method, mounting device, and transfer device, semiconductor chips can be mounted on circuit boards with high productivity.

The mounting method, mounting apparatus, and transfer apparatus of the present invention are not limited to the configurations described above and may also have other configurations within the scope of the present invention. For example, in the above description, the first and second transfer steps are performed under atmospheric pressure. However, by providing the transfer unit 10 with a pressure reducing portion (not shown), they can also be performed under a reduced pressure environment.

Furthermore, while the semiconductor chip is transferred using a laser in the transfer unit in the above description, other methods can also be used. For example, the semiconductor chip can be transferred by attaching it to an adhesive sheet.

Furthermore, while the above description uses a galvanometer mirror in the transfer unit to control the laser irradiation position, this is not limited to this method and other known technologies, such as a polygonal mirror, can also be used for control. Furthermore, the laser irradiation position can be controlled solely by the relative movement of the transfer substrate and the substrate being transferred, rather than by mirror reflection.

Furthermore, in the above description, the first transfer step and the second transfer step are performed by the same transfer unit. However, separate transfer units may be provided to perform the steps.

Furthermore, the inspection of semiconductor chips performed by the inspection unit is not limited to visual inspection based on image analysis or photoluminescence, and may also be inspection using, for example, X-rays.

Furthermore, while the above description describes the second substrate as the circuit substrate ultimately mounted on a product such as a display, this is not limiting. For example, a substrate to which transfer is performed at a stage prior to the circuit substrate can also serve as the second substrate. However, in this case, the substrates to which transfer is performed at the second component pitch include the circuit substrate, which increases the transfer time. Therefore, it is ideal to use the circuit substrate as the second substrate as described above, and to transfer components from substrate to substrate while the component pitch is small before transferring the components to the second substrate.

Furthermore, in the above description, the first device spacing refers to the spacing of devices formed on the growth substrate at the final stage of wafer dicing, and the devices are transferred from the growth substrate to the first substrate in a manner that maintains this spacing. However, this is not limiting; the spacing can also be changed at an intermediate stage, as long as the devices are ultimately arranged on the circuit board at a specific spacing.

Furthermore, in the above description, the scanning speed in both the first transfer mode and the second transfer mode is the same as the maximum speed controllable by the galvanometer mirror. However, this is not limiting. For example, the scanning speed in the first transfer mode may be slower than the scanning speed in the second transfer mode.

1: Semiconductor chip (component)

3a: Adhesive layer

4a: First transfer substrate

11b: Laser light

14: Transfer substrate holding portion

21: Camera

22: Inspected substrate holding unit

Claims (15)

A mounting method is characterized by having: a first transfer step of transferring a plurality of semiconductor chips formed on a carrier substrate to a first transfer substrate; an inspection step of inspecting the state of the semiconductor chips transferred to the first transfer substrate; a second transfer step of transferring only the semiconductor chips judged to be normal by the inspection step from the first transfer substrate to the second transfer substrate; and a mounting step of transferring the semiconductor chips transferred to the second transfer substrate. Mounted on a circuit board; performing the first transfer step and the second transfer step by laser lift; the spacing between the semiconductor chips transferred to the first transfer substrate by the first transfer step, i.e., the first element spacing, is smaller than the spacing between the semiconductor chips transferred to the second transfer substrate by the second transfer step, i.e., the second element spacing; and the oscillation frequency of the laser light in the first transfer step is higher than the oscillation frequency of the laser light in the second transfer step. The mounting method of claim 1, wherein the mounting step includes a pressing step of pressing the semiconductor chip together with the second transfer substrate onto the circuit board, and a separation step of separating the second transfer substrate from the semiconductor chip, wherein the semiconductor chip is selectively transferred in the second transfer step such that the semiconductor chip is arranged on the second transfer substrate, which is to be subjected to the pressing step, corresponding to the position at which the semiconductor chip is to be arranged on the circuit board. In the mounting method of claim 1 or 2, the oscillation frequency of the laser light can be controlled by a laser light source that emits the laser light, and the optical path of the laser light can be controlled by an optical path control unit. When the optical path control unit is operated so that the movement speed of the laser light irradiation point on the first transfer substrate is approximately the maximum speed controllable by the optical path control unit, the oscillation frequency of the laser light in the second transfer step is the oscillation frequency at which each laser light emitted from the laser light source can transfer the semiconductor chip at the second element interval. In the installation method of claim 1 or 2, the optical path of the laser light is controlled by a galvanometer mirror. The mounting method of claim 2 comprises: a post-mounting inspection step of inspecting the performance of the semiconductor chip mounted on the circuit substrate; and a repair step of adding or replacing a repair semiconductor chip, which is used to replace the semiconductor chip determined to be abnormal in the post-mounting inspection step, with the circuit substrate; in the repair step, semiconductor chips are selectively transferred from the first transfer substrate to the second transfer substrate in a manner such that the semiconductor chips are arranged corresponding to the positions at which the repair semiconductor chip should be arranged on the circuit substrate; the semiconductor chip and the second transfer substrate are press-bonded to the circuit substrate; and the second transfer substrate is separated from the semiconductor chip. In the mounting method of claim 1 or 2, the inspection step includes inspecting the condition of the semiconductor chip on the first transfer substrate by visual inspection based on image analysis. In the mounting method of claim 1 or 2, in the inspection step, the state of the semiconductor chip on the first transfer substrate is inspected by photoluminescence. The mounting method of claim 1 or 2 further includes a chip removal step between the inspection step and the second transfer step, wherein the chip removal step removes semiconductor chips that are judged to be abnormal from the first transfer substrate. A mounting device is characterized by comprising: a transfer unit that transfers a plurality of semiconductor chips from a carrier substrate to a first transfer substrate and transfers the semiconductor chips from the first transfer substrate to a second transfer substrate; an inspection unit that inspects the state of the semiconductor chips transferred to the first transfer substrate; and a mounting unit that mounts the semiconductor chips transferred to the second transfer substrate on a circuit substrate; only semiconductor chips that are judged to be normal by the inspection of the inspection unit are transferred from the first transfer substrate to the second transfer substrate; the transfer unit is equipped with: a laser light source that emits laser light, and the oscillation frequency of the laser light is controllable; and an optical path control unit that controls the optical path of the laser light; and the transfer unit controls the irradiation position of the laser light on the transfer substrate by the optical path control unit, and controls the irradiation position of the laser light on the transfer substrate by the optical path control unit. Laser lifting transfers any of the plurality of components held by the transfer substrate to a target substrate. The transfer section has a first transfer mode, in which the components are transferred to the first substrate using the first substrate as the target substrate; and a second transfer mode, in which the components held by the first substrate are transferred to the second substrate using the first substrate as the transfer substrate and the second substrate as the target substrate. The spacing between the components transferred to the first substrate in the first transfer mode, i.e., a first component spacing, is smaller than the spacing between the components transferred to the second substrate in the second transfer mode, i.e., a second component spacing. The oscillation frequency of the laser light in the first transfer mode is higher than the oscillation frequency of the laser light in the second transfer mode. A transfer device is characterized by comprising: a laser light source that emits laser light, and the oscillation frequency of the laser light is controllable; and an optical path control unit that controls the optical path of the laser light; and the transfer device controls the irradiation position of the laser light on the transfer substrate by the optical path control unit, and transfers any of a plurality of elements held by the transfer substrate to a transferred substrate by laser lifting; and the transfer device has: a first transfer mode, which uses a first substrate as the transferred substrate and transfers the above-mentioned element to the first substrate; and a second transfer mode. The transfer mode uses the first substrate as the transfer substrate and the second substrate as the transferred substrate, transferring the components held by the first substrate to the second substrate. The spacing between the components transferred to the first substrate by the first transfer mode, i.e., a first component spacing, is smaller than the spacing between the components transferred to the second substrate by the second transfer mode, i.e., a second component spacing. The oscillation frequency of the laser light in the first transfer mode is higher than the oscillation frequency of the laser light in the second transfer mode. The transfer device of claim 10, wherein the second substrate is a circuit substrate having a wiring circuit formed thereon. In the transfer device of claim 10 or 11, when the optical path control unit is operated so that the movement speed of the laser beam irradiation point on the first substrate is approximately the maximum speed controllable by the optical path control unit, the oscillation frequency of the laser beam in the second transfer mode is the oscillation frequency at which each laser beam emitted from the laser light source can cause the device to be transferred at intervals with the second device. In the transfer device of claim 10 or 11, the optical path control unit is a galvanometer mirror. In the transfer device of claim 10 or 11, the first element spacing is equal to the spacing between the elements on the substrate on which the elements are grown, i.e., the spacing between the elements on the growth substrate. The transfer device of claim 10 or 11 further includes a performance determination mode for determining the operating performance of each of the components. In the first transfer mode, only components determined to be normal in the performance determination mode are transferred to the first substrate.