Substrate processing method and substrate processing system

Abstract

This substrate processing method involves: preparing a die-equipped substrate that includes a substrate and a plurality of dies bonded to one surface of the substrate, each of the dies having a bonding surface bonded to the substrate and a rear surface facing in the opposite direction from the bonding surface; and performing laser processing on the rear surfaces of the dies.

Description

Substrate processing method and substrate processing system

[0001] The present disclosure relates to a substrate processing method and a substrate processing system.

[0002] The substrate processing method described in Patent Document 1 includes preparing a substrate with chips. The substrate with chips includes a substrate and a plurality of chips bonded to one side of the substrate. The processing method described in Patent Document 1 includes grinding the plurality of chips bonded to one side of the substrate. The chips are also called dies.

[0003] Japanese Patent No. 7281901

[0004] One aspect of the present disclosure provides techniques for improving the quality of die-attached substrates.

[0005] A substrate processing method according to one aspect of the present disclosure includes preparing a die-attached substrate having a substrate and a plurality of dies bonded to one side of the substrate, the dies including a bonding surface bonded to the substrate and a back surface facing opposite to the bonding surface, and laser processing the back surfaces of the dies.

[0006] According to one aspect of the present disclosure, the quality of the die-attached substrate can be improved.

[0007] FIG. 1 is a plan view showing a substrate processing system according to an embodiment. FIG. 2 is a cross-sectional view showing an example of a die-attached substrate. FIG. 3 is a flowchart showing a substrate processing method according to an embodiment. FIG. 4 is a side view showing an example of a grinding apparatus. FIG. 5 is a plan view showing an example of a grinding wheel rotation trajectory. FIG. 6 is a diagram showing an example of map data of die thickness. FIG. 7 is a side view showing an example of a laser processing apparatus. FIG. 8 is a flowchart showing an example of processing by a control circuit. FIG. 9 is a cross-sectional view showing an example of steps S201 to S202. FIG. 10 is a cross-sectional view showing an example of step S203. FIG. 11 is a plan view showing an example of a movement path of an irradiation point in step S205. FIG. 12 is a cross-sectional view showing an example of the processing order in step S205. FIG. 13 is a cross-sectional view showing a modified example of FIG. 12.

[0008] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Note that the same or corresponding components in each drawing are denoted by the same reference numerals, and descriptions thereof may be omitted. In this specification, the X-axis direction, Y-axis direction, and Z-axis direction are perpendicular to each other. The X-axis direction and Y-axis direction are horizontal directions, and the Z-axis direction is vertical. The X-axis direction includes the positive X-axis direction and the negative X-axis direction that is opposite to the positive X-axis direction. The Y-axis direction includes the positive Y-axis direction and the negative Y-axis direction that is opposite to the positive Y-axis direction. The Z-axis direction includes the positive Z-axis direction and the negative Z-axis direction that is opposite to the positive Z-axis direction.

[0009] A substrate processing system 1 according to one embodiment will be described with reference to Fig. 1. The substrate processing system 1 processes, for example, a die-attached substrate as shown in Fig. 2. The die-attached substrate DW has a substrate W and a plurality of dies D bonded to the substrate W. The plurality of dies D are obtained by dicing. The die D has a bonding surface Da bonded to the substrate W and a back surface Db facing opposite to the bonding surface Da. The die D is also called a chip.

[0010] The substrate W has a first base substrate W1 and a plurality of first devices W2 formed on the first base substrate W1. The first base substrate W1 is, for example, a silicon wafer, a compound semiconductor wafer, or a glass substrate. The first devices W2 include semiconductor elements, circuits, terminals, or the like. The substrate W has a plurality of first devices W2 on a bonding surface Wa with the die D.

[0011] The die D has a second base substrate D1 and a second device D2 formed on the second base substrate D1. The second base substrate D1 is, for example, a silicon wafer, a compound semiconductor wafer, or a glass substrate. The second device D2 includes a semiconductor element, a circuit, a terminal, or the like. The die D has, on a bonding surface Da with the substrate W, the second device D2 that is electrically connected to a first device W2 of the substrate W. One second device D2 is electrically connected to one first device W2, but multiple second devices D2 may also be electrically connected to one first device W2.

[0012] Although not shown, a second die may be prepared separately from the die D. The second die has a third device on its bonding surface with the substrate W, which is electrically connected to the first device W2 of the substrate W. The third device may have a different function, i.e., a different electrical circuit, from the second device D2. The second device D2 and the third device may be electrically connected to one first device W2. Although one third device is electrically connected to one first device W2, multiple third devices may also be electrically connected.

[0013] As shown in FIG. 1, the substrate processing system 1 includes a loading / unloading station 2 , a processing station 3 , and a control circuit 9 .

[0014] The carry-in / out station 2 includes a mounting table 20. Cassettes C1 to C2 are placed on the mounting table 20. Cassette C1 stores a die-attached substrate DW before processing. Cassette C2 stores a die-attached substrate DW after processing. The number of cassettes C1 and C2 is not particularly limited. A cassette not shown may store a die-attached substrate DW that has become defective during processing.

[0015] The carry-in / out station 2 includes a first transfer region 21 and a first transfer device 22. The first transfer region 21 is adjacent to the mounting table 20 and the transition device 33. The first transfer device 22 transfers the die-attached substrate DW between multiple devices adjacent to the first transfer region 21. The first transfer device 22 has a transfer arm that holds the die-attached substrate DW and a drive unit that moves or rotates the transfer arm. The transfer arm is capable of moving horizontally (in both the X-axis and Y-axis directions) and vertically, and of rotating about a vertical axis. Multiple transfer arms may be provided.

[0016] The processing station 3 includes a second transfer region 31, a second transfer device 32, a transition device 33, a grinding device 34, a cleaning device 35, a measuring device 36, and a laser processing device 37. The arrangement and number of devices constituting the processing station 3 are not limited to those shown in FIG.

[0017] The transition device 33 temporarily stores the die-attached substrate DW. The transition device 33 is provided between the first transfer region 21 and the second transfer region 31, and relays the die-attached substrate DW between the first transfer device 22 and the second transfer device 32.

[0018] The second transfer region 31 is adjacent to a transition device 33, a grinding device 34, a cleaning device 35, a measuring device 36, and a laser processing device 37. The second transfer device 32 transfers the die-attached substrate DW between multiple devices adjacent to the second transfer region 31. The second transfer device 32 has a transfer arm that holds the die-attached substrate DW and a drive unit that moves or rotates the transfer arm. The transfer arm is capable of moving horizontally (in both the X-axis and Y-axis directions) and vertically, and of rotating about a vertical axis. Multiple transfer arms may be provided.

[0019] The grinding device 34 grinds the multiple dies D bonded to one side of the substrate W. The multiple dies D can be thinned. When the substrate W and the die D are bonded, the die D is thick, making it easy to handle. The grinding device 34 grinds the multiple dies D, for example, by pressing the grinding stone against the multiple dies D while rotating the grinding stone and the die-mounted substrate DW separately. The grinding device 34 presses the grinding stone against the back surface Db of the die D to grind the back surface Db of the die D.

[0020] The cleaning device 35 cleans the die-attached substrate DW. For example, the cleaning device 35 cleans the die-attached substrate DW after grinding the die D. This makes it possible to remove grinding debris adhering to the die-attached substrate DW. The cleaning device 35 scrubs the die-attached substrate DW with, for example, a brush or a sponge. Note that the cleaning device 35 may clean the die-attached substrate DW before grinding the die D.

[0021] The measuring device 36 measures the thickness of the die D bonded to one side of the substrate W. The measuring device 36 measures the thickness of the die D by measuring the difference in height between the bonding surface Wa of the substrate W and the back surface Db of the die D. The measuring device 36 measures the thickness of each of the multiple dies D. The measuring device 36 may measure the waviness of the back surface Db of each die D. The waviness of the back surface Db of each die D is equal to the unevenness in thickness of each die D. The measuring device 36 may measure the unevenness in thickness of each die D.

[0022] The laser processing device 37 performs laser processing on the back surface Db of the die D based on the measurement results of the measuring device 36. The laser processing device 37 performs at least one of (preferably both of) uniforming the thickness of the multiple dies D and flattening the back surface Db of each die D. This can improve the quality of the die-mounted substrate DW. Note that the laser processing device 37 may only flatten the back surface Db of each die D, and not necessarily uniform the thickness of the multiple dies D.

[0023] The control circuit 9 is, for example, a computer, and includes an arithmetic unit 91 such as a CPU (Central Processing Unit), and a storage unit 92 such as a memory. The storage unit 92 stores programs that control various processes executed in the substrate processing system 1. The control circuit 9 controls the operation of the substrate processing system 1 by causing the arithmetic unit 91 to execute the programs stored in the storage unit 92. A lower-level control circuit that controls the operation of each device constituting the substrate processing system 1 may be provided, and a higher-level control circuit that controls multiple lower-level control circuits may be provided. The control circuit 9 may be configured with the lower-level control circuit and the higher-level control circuit.

[0024] The control circuit 9 includes electronic circuits such as a CPU, a field programmable gate array (FPGA), or an application specific integrated circuit (ASIC), and performs the various control operations described in this specification by executing instruction codes stored in a memory or by being a circuit designed for a specific application.

[0025] Next, a substrate processing method according to one embodiment will be described with reference to FIG. 3. The substrate processing method includes, for example, steps S101 to S105. Steps S101 to S105 are performed under the control of the control circuit 9. Step S101 includes preparing a die-attached substrate DW. Step S101 includes, for example, loading a cassette C1 containing the die-attached substrate DW into the substrate processing system 1.

[0026] First, the first transfer device 22 takes out the die-attached substrate DW from the cassette C1 and transfers it to the transition device 33. Next, the second transfer device 32 takes out the die-attached substrate DW from the transition device 33 and transfers it to the grinding device .

[0027] Next, the grinding device 34 grinds the multiple dies D that make up the die-attached substrate DW (step S102). This allows the multiple dies D to be thinned. The grinding device 34 grinds the back surfaces Db of the dies D. Thereafter, the second transport device 32 removes the die-attached substrate DW from the grinding device 34 and transports it to the cleaning device 35.

[0028] Next, the cleaning device 35 cleans the die-attached substrate DW (step S103). Grinding debris adhering to the die-attached substrate DW can be removed. Thereafter, the second transfer device 32 removes the die-attached substrate DW from the cleaning device 35 and transfers it to the measurement device 36.

[0029] Next, the measuring device 36 measures the thickness of the die D constituting the die-fitted substrate DW (step S104). The measuring device 36 measures the thickness of each of the multiple dies D. The measuring device 36 also measures the waviness of the back surface Db of the die D. Thereafter, the second transport device 32 removes the die-fitted substrate DW from the measuring device 36 and transports it to the laser processing device 37.

[0030] Next, the laser processing device 37 laser processes the multiple dies D that make up the die-fitted substrate DW based on the measurement results of the measuring device 36 (step S105). The laser processing device 37 uniforms the thickness of the multiple dies D. The laser processing device 37 also flattens the back surfaces Db of the dies D. Thereafter, the second transfer device 32 removes the die-fitted substrate DW from the laser processing device 37 and transfers it to the transition device 33.

[0031] Finally, the first transfer device 22 takes out the die-attached substrate DW from the transition device 33 and stores it in the cassette C2. The die-attached substrate DW stored in the cassette C2 is carried out from the substrate processing system 1.

[0032] As will be described in detail later, unevenness in the thickness of the die D may occur in step S102 (grinding the die D). The unevenness in thickness may occur both among multiple dies D and within one die D. According to this embodiment, step S105 (laser processing) is performed after step S102. This makes it possible to perform at least one of (preferably both of) uniforming the thickness of the multiple dies D and flattening the back surface Db of each die D, thereby improving the quality of the die-mounted substrate DW.

[0033] The substrate processing method may include step S105 and may not include step S102. This is because unevenness in the thickness of the die D may occur even before step S102. For example, before bonding the die D to the substrate W, the back surface Db of the die D may be ground. At this time, the bonding surface Da of the die D is covered with a protective tape made of resin. The protective tape is deformed by pressure, causing unevenness in the thickness of the die D.

[0034] Next, an example of the grinding device 34 will be described with reference to Figures 4 to 6. As shown in Figure 4, the grinding device 34 grinds the multiple dies D by, for example, pressing the tool T against the multiple dies D while rotating the tool T and the die-mounted substrate DW. The tool T includes, for example, a disk-shaped wheel T1 and multiple grindstones T2 arranged in a ring shape on the underside of the wheel T1.

[0035] The grinding device 34 includes a chuck 341 that holds the die-attached substrate DW from the side opposite to the tool T, a first rotation unit 342 that rotates the chuck 341, a second rotation unit 343 that rotates the tool T, and an elevation unit 344 that raises and lowers the tool T. The first rotation unit 342 rotates the die-attached substrate DW together with the chuck 341, and the second rotation unit 343 rotates the tool T, while the elevation unit 344 lowers the tool T. The grinding device 34 then presses the grindstone T2 against the back surface Db of the die D, thereby grinding the back surface Db of the die D.

[0036] The chuck 341 holds the die-attached substrate DW from the side opposite to the tool T. The chuck 341 is, for example, a vacuum chuck. The chuck 341 adsorbs the die-attached substrate DW to its upper surface 341a. The upper surface 341a of the chuck 341 may be a conical surface that is rotationally symmetric about a first rotation axis 342b (described later). The die-attached substrate DW deforms in accordance with the upper surface 341a of the chuck 341.

[0037] The first rotating unit 342 rotates the chuck 341. The first rotating unit 342 has a first rotation motor 342a and a first rotation shaft 342b rotated by the first rotation motor 342a. The chuck 341 is provided on the upper end of the first rotation shaft 342b. The first rotation motor 342a rotates the chuck 341 together with the first rotation shaft 342b. The first rotation shaft 342b may be inclined as shown in FIG. 4 .

[0038] The second rotation unit 343 rotates the tool T. The second rotation unit 343 has, for example, a second rotation motor 343a, a vertical second rotation shaft 343b rotated by the second rotation motor 343a, and a flange 343c provided at the lower end of the second rotation shaft 343b. The flange 343c is disposed horizontally, and the tool T is attached to its lower surface. The second rotation motor 343a rotates the second rotation shaft 343b, thereby rotating the tool T attached to the lower surface of the flange 343c.

[0039] The lifting unit 344 lifts and lowers the tool T. The lifting unit 344 has, for example, a vertical Z-axis guide 344a, a Z-axis slider 344b that moves along the Z-axis guide 344a, and an lifting motor 344c that moves the Z-axis slider 344b. A second rotation motor 343a is fixed to the Z-axis slider 344b via a motor holder 344d. The lifting unit 344 has a ball screw (not shown) that converts the rotational motion of the lifting motor 344c into linear motion of the Z-axis slider 344b.

[0040] 5, the rotation locus of the grindstone T2 is, for example, a circular ring passing through the rotation center of the die-attached substrate DW. The die-attached substrate DW is deformed to fit the upper surface 341a of the chuck 341. The upper surface 341a of the chuck 341 is a conical surface that is rotationally symmetric about the first rotation axis 342b. Therefore, the portion of the rotation locus of the grindstone T2 where the grindstone T2 comes into contact with the die D is an arc-shaped region B.

[0041] The die-mounted substrate DW and the grindstone T2 are each rotated, and the number and positions of the dies D present in the arc-shaped region B change over time. Therefore, the distribution of pressure pressing the grindstone T2 against the dies D changes over time. As a result, unevenness occurs in the thickness of the dies D, as shown in Figure 6. The unevenness in thickness occurs both among multiple dies D and within a single die D.

[0042] According to this embodiment, after the grinding device 34 grinds the back surface Db of each of the multiple dies D, the laser processing device 37 laser processes the back surface Db of each of the multiple dies D. The laser processing device 37 performs at least one of (preferably both of) making the thickness of the multiple dies D uniform and flattening the back surface Db of each die D. This can improve the quality of the die-mounted substrate DW.

[0043] Next, an example of the laser processing device 37 will be described with reference to Fig. 7. The laser processing device 37 includes, for example, a substrate holder 371, a light source 372, and a galvanometer scanner 373. The laser processing device 37 may also include an fθ lens 374, a homogenizer 375, and an aperture 376.

[0044] The substrate holding unit 371 holds the die-attached substrate DW. For example, the substrate holding unit 371 holds the die-attached substrate DW horizontally from below with the back surface Db of the die D facing upward. The substrate holding unit 371 may adsorb the die-attached substrate DW. The substrate holding unit 371 may be a vacuum chuck or an electrostatic chuck.

[0045] The light source 372 emits a laser beam LB. The light source 372 is not particularly limited, but may be, for example, a green laser. At an irradiation point P of the laser beam LB, the die D either changes state locally from a solid phase to a gas phase and scatters, or scatters while remaining in the solid phase, thereby locally removing the die D. The laser beam LB may be focused and applied to the back surface Db of the die D. In this embodiment, the irradiation point P is a focused point where the power density is highest, but it does not have to be a focused point.

[0046] The light source 372 is, for example, a pulsed laser. The irradiation time per pulse is, for example, 30 nsec or less. If the irradiation time per pulse is 30 nsec or less, a high-power density laser beam LB can be irradiated onto the die D in a short period of time, preventing overheating of the die D. This prevents thermal deterioration of the die D, for example, preventing the formation of a discolored layer. The irradiation time per pulse is preferably 10 psec or less. If the irradiation time per pulse is 10 psec or less, thermal deterioration of the die D can be prevented even if irradiation points P are formed multiple times at the same location.

[0047] The galvanometer scanner 373 is disposed, for example, above the die-attached substrate DW held by the substrate holder 371. The galvanometer scanner 373 allows the irradiation point P of the laser beam LB to be moved on the back surface Db of the die D without moving the substrate holder 371. Even when the substrate holder 371 does not adsorb the die-attached substrate DW, no positional deviation of the die-attached substrate DW with respect to the substrate holder 371 occurs as long as the substrate holder 371 does not move. Therefore, the position of the irradiation point P can be controlled with high precision.

[0048] The galvanometer scanner 373 includes two pairs of galvanometer mirrors 373a and galvanometer motors 373b (only one pair is shown in FIG. 7). One galvanometer motor 373b rotates one galvanometer mirror 373a to displace the irradiation point P in the X-axis direction. The other galvanometer motor 373b rotates another galvanometer mirror 373a to displace the irradiation point P in the Y-axis direction.

[0049] The galvano scanner 373 is an example of a moving unit that moves the irradiation point P. The moving unit may move the substrate holding unit 371 in the X-axis direction and the Y-axis direction, and may have a motor and a ball screw mechanism that converts the rotational motion of the motor into linear motion of the substrate holding unit 371. The moving unit may also have a mechanism that rotates the substrate holding unit 371 around a vertical axis.

[0050] The fθ lens 374 forms a focal plane perpendicular to the Z-axis direction. While the galvanometer scanner 373 moves the position of the irradiation point P in the X-axis or Y-axis direction, the fθ lens 374 maintains the shape and size of the irradiation point P on the back surface Db of the die D. In this embodiment, the height of the irradiation point P coincides with the height of the focal plane, but it does not have to coincide with the height of the focal plane, and may be higher or lower than the height of the focal plane.

[0051] The homogenizer 375 converts the power density distribution of the laser beam LB from a Gaussian distribution to a top-hat distribution, homogenizing the power density. The aperture 376 shapes the cross-sectional shape of the laser beam LB into a rectangle. The aperture 376 is a light-shielding film with a rectangular opening. The opening allows the laser beam LB to pass through a portion where the power density is constant. The homogenizer 375 and the aperture 376 can form a rectangular irradiation point P with a uniform power density.

[0052] Next, an example of processing by the control circuit 9 will be described with reference to Figures 8 to 13. Step S201 involves the control circuit 9 acquiring measurement results from the measurement device 36. The measurement results from the measurement device 36 include at least one (preferably both) of thickness variations among the multiple dies D and thickness variations within each die D. The thickness variations within each die D are equal to the waviness of the back surface Db of each die D.

[0053] 9 shows an example of thickness variations among multiple dies D and thickness variations within each die D. In FIG. 9, Z indicates the height of the back surface Db of the die D from the reference point P0, the dashed lines indicate contour lines, and E indicates the processing amount of the back surface Db of the die D. The height of the reference point P0 is the height of the back surface Db of the die D after laser processing. The back surface Db of the die D is removed to the height of the reference point P0 by laser processing. The height of the reference point P0 is set based on the bonding surface Wa of the substrate W so that the thickness of the die D after laser processing becomes the target thickness. The reference point P0 may be the lowest point on the back surfaces Db of the multiple dies D before laser processing, or may be a point shifted lower by a set amount from that lowest point toward the bonding surface Wa of the substrate W.

[0054] Step S202 involves creating map data of the machining amount E as shown in Fig. 9 based on the measurement results of the measuring device 36 acquired in step S201. The machining amount E is determined mainly by the height Z from the reference point P0.

[0055] Step S203 involves creating n (e.g., four) layers L1, L2, L3, and L4 by dividing the map data of the processing amount E created in step S202 according to height as shown in FIG. 10 , where n is the maximum number of layers. The number of layers may be different for each die D. n may be any integer equal to or greater than 2 and is not limited to 4.

[0056] n is set based on the maximum value Emax of the processing amount E and the processing amount per irradiation of the laser beam. The processing amount per irradiation is determined by the power density at the irradiation point P. Furthermore, n may be set based on the upper limit of the surface roughness after laser processing.

[0057] In this embodiment, the n layers L1, L2, L3, and L4 have the same thickness, but may have different thicknesses. The thickness of each of the n layers L1, L2, L3, and L4 is appropriately set depending on the power density of the irradiation spot P and the amount of overlap between the trajectories of adjacent irradiation spots P, and is, for example, 0.1 μm to 1.0 μm.

[0058] Step S204 involves setting a machining area for each of the layers L1, L2, L3, and L4 created in step S203. The machining areas for the layers L1, L2, L3, and L4 are identical to the layers L1, L2, L3, and L4, respectively. If step S203 is not performed, step S204 may simply set an area having a height equal to or greater than the reference point P0 as the machining area.

[0059] Step S205 involves moving the irradiation point P in the processing area A set in step S204, as shown in Fig. 11. The laser processing is an ablation process. At the irradiation point P of the laser beam LB, the die D either changes from a solid phase to a gas phase locally and scatters, or scatters in the solid phase, and the die D is locally ablated.

[0060] In step S205, for example, control may be performed to change the number of times of processing and the processing time according to the processing amount E of the processing position. The processing amount E is set so that the back surface Db of the die D becomes flat after laser processing.

[0061] Next, referring again to FIG. 11 , an example of movement of the irradiation point P in the processing area A will be described. In FIG. 11 , the arrows indicate the movement direction and movement range of the irradiation point P. The movement range is the range from the start point of the movement to the end point of the movement. Note that the movement of the irradiation point P is not limited to the example shown in FIG. 11 . For example, the movement of the irradiation point P may be performed in a spiral pattern.

[0062] 11, the control circuit 9 repeatedly controls the movement of the irradiation point P in a first direction (e.g., the positive direction of the X-axis) and the movement of the irradiation point P in a second direction (e.g., the negative direction of the X-axis) opposite to the first direction. In addition, before and after changing the movement direction of the irradiation point P between the first direction and the second direction, the control circuit 9 also controls the shift of the position of the irradiation point P in a third direction (e.g., the negative direction of the Y-axis) perpendicular to the first and second directions.

[0063] A first locus of the irradiation point P moving in the first direction and a second locus of the irradiation point P moving in the second direction, which are adjacent in the third direction, may partially overlap in the third direction. The pitch of the irradiation point P in the third direction may be smaller than the size of the irradiation point P in the third direction so that the first locus and the second locus partially overlap in the third direction. By partially overlapping the first locus and the second locus in the third direction, it is possible to make the processing marks formed along the movement direction of the irradiation point P (first direction or second direction) thinner.

[0064] Step S205 includes moving the irradiation point P of the laser beam LB in the processing area A for each of the layers L1, L2, L3, and L4, as shown in Figure 12 or 13. The n layers L1, L2, L3, and L4 are removed in a desired order. For example, a layer with a higher height Z (e.g., layer L1) is removed before a layer with a lower height Z (e.g., layer L2).

[0065] Step S205 involves moving the irradiation point P over the entire processing area of ​​the kth layer to be removed, and then moving the irradiation point P over the entire processing area of ​​the (k+1)th layer to be removed, where k is an integer between 1 and (n-1). This removes layers L1, L2, L3, and L4, respectively.

[0066] According to this embodiment, the irradiation point P is moved in the processing area for each of the layers L1, L2, L3, and L4. The n layers L1, L2, L3, and L4 can be removed in the desired order. Because each of the layers L1, L2, L3, and L4 has a constant thickness, the power density of the irradiation point P does not need to be changed in most of the processing area, and the output of the light source 372 does not need to be changed. This simplifies the control of laser processing.

[0067] As described above, the n layers L1, L2, L3, and L4 may have the same thickness. The power density of the irradiation point P does not need to be changed for each of the layers L1, L2, L3, and L4, and the output of the light source 372 does not need to be changed. This simplifies control of the laser processing. However, taking into account factors such as the gradient of the waviness, two or more of the n layers L1, L2, L3, and L4 may have different thicknesses.

[0068] 12, after removing all of the layers L1, L2, L3, and L4 for one die D, removal of all of the layers L2, L3, and L4 for another die D may be started. Also, as shown in FIG. 13, after removing a layer of the same height (e.g., layer L2) across multiple dies D, another layer of the same height (e.g., layer L3) across multiple dies D may be removed.

[0069] In this embodiment, the irradiation point P is moved in the processing area for each of the layers L1, L2, L3, and L4, but the technology of the present disclosure is not limited to this. If the power density of the irradiation point P is changed each time according to the position of the irradiation point P while referring to the height of the map data of the processing amount E, it is not necessary to divide the map data of the processing amount E into n layers.

[0070] Although the embodiments of the substrate processing method and substrate processing system according to the present disclosure have been described above, the present disclosure is not limited to the above embodiments. Various changes, modifications, substitutions, additions, deletions, and combinations are possible within the scope of the claims. These naturally fall within the technical scope of the present disclosure.

[0071] This application claims priority based on Japanese Patent Application No. 2023-140856 filed with the Japan Patent Office on August 31, 2023, the entire contents of which are incorporated herein by reference.

[0072] D Die Da Bonding surface Db Back surface DW Substrate with die W Substrate

Claims

1. A substrate processing method comprising: preparing a substrate having a substrate and a plurality of dies bonded to one side of the substrate, the dies including a bonding surface to be bonded to the substrate and a back surface facing opposite to the bonding surface; and laser processing the back surfaces of the dies.

2. The substrate processing method according to claim 1, comprising: measuring the thickness of each of the plurality of dies; and performing the laser processing based on the measured thickness of each of the plurality of dies, thereby making the thickness of the plurality of dies uniform.

3. A substrate processing method as described in claim 2, comprising: creating map data of the amount of processing in the laser processing based on the measured thicknesses of each of the multiple dies; dividing the map data of the amount of processing according to height to create n (n is an integer of 2 or more) layers; setting a processing area for each of the layers; and moving an irradiation point of the laser beam in the processing area for each of the layers.

4. The substrate processing method according to claim 1, comprising: measuring a waviness of the back surface of one of the die; and performing the laser processing based on the measured waviness of the back surface of one of the die, thereby flattening the back surface of the die.

5. A substrate processing method as described in claim 4, comprising: creating map data of the amount of processing in the laser processing based on the measured undulation of the back surface of one of the dies; creating n (n is an integer of 2 or more) layers by dividing the map data of the amount of processing according to height; setting a processing area for each of the layers; and moving an irradiation point of the laser beam in the processing area for each of the layers.

6. A substrate processing method according to any one of claims 1 to 5, further comprising grinding the back surface of each of the plurality of dies after preparing the substrate with the dies and before performing the laser processing.

7. A substrate processing system comprising: a transport device for transporting a substrate having a substrate and a plurality of dies bonded to one side of the substrate, the dies including a bonding surface to be bonded to the substrate and a back surface facing opposite to the bonding surface; a measuring device for measuring the thickness of each of the plurality of dies or the waviness of the back surfaces; a laser processing device for performing laser processing of the back surfaces of the dies; and a control circuit for controlling the laser processing device based on the measurement results of the measuring device.

8. The substrate processing system of claim 7, wherein the measuring device measures the thickness of each of the plurality of dies, and the control circuit controls the laser processing device based on the measurement results of the measuring device, thereby performing control to make the thickness of the plurality of dies uniform.

9. The substrate processing system of claim 8, wherein the control circuit performs the following controls: creating map data of the amount of processing in the laser processing based on the measurement results of the measuring device; creating n (n is an integer of 2 or more) layers by dividing the map data of the amount of processing according to height; setting a processing area for each of the layers; and moving the irradiation point of the laser beam in the processing area for each of the layers.

10. The substrate processing system of claim 7, wherein the measuring device measures the waviness of the back surface of one of the dies, and the control circuit controls the laser processing device based on the measurement results of the measuring device, thereby controlling the flattening of the back surface of the die.

11. The substrate processing system of claim 10, wherein the control circuit performs the following controls: creating map data of the amount of processing in the laser processing based on the measurement results of the measuring device; creating n (n is an integer of 2 or more) layers by dividing the map data of the amount of processing according to height; setting a processing area for each of the layers; and moving the irradiation point of the laser beam in the processing area for each of the layers.

12. The substrate processing system according to any one of claims 7 to 11, further comprising a grinding device that grinds the backside of each of the plurality of dies before measurement by the measurement device.

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