Resin coating method and resin coating device

Abstract

To properly cure the entire liquid resin supplied to the surface of a substrate to coat the surface of the substrate with a resin.SOLUTION: A resin coating method for coating a resin on one surface of a substrate includes a liquid resin supplying step of supplying a liquid resin that is hardened by being irradiated with ultraviolet rays onto one surface of the substrate, a pressing step of covering the liquid resin supplied to the one surface of the substrate with a cover film and spreading the liquid resin with a flat pressing surface through the cover film, a first ultraviolet irradiation step of irradiating the spread liquid resin with ultraviolet rays, a second ultraviolet irradiation step of locally irradiating the liquid resin with ultraviolet rays along the outer periphery of the substrate before or after the first ultraviolet irradiation step, and a cutting step of cutting the cover film and the liquid resin along the outer periphery of the substrate with a cutter.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a resin coating method and a resin coating apparatus for coating a surface of a substrate with a resin. [Background technology]

[0002] Device chips used in electronic devices such as mobile phones and computers are formed by grinding a substrate on which a number of devices are arranged on the surface from the back side to thin it, and dividing the substrate into individual devices. Grinding of the substrate is performed by a grinding device. In the grinding device, the substrate is held on a chuck table with the back side exposed upward, and a grinding wheel moving on a circular orbit is brought into contact with the back side of the substrate to grind the substrate. At this time, in order to protect the front side of the substrate, a protective member having a base layer and an adhesive layer laminated thereon is attached in advance to the front surface of the substrate.

[0003] Patterns constituting devices and wiring are disposed on the surface side of the substrate. In addition, bumps serving as electrodes for devices may be formed in advance on the surface side of the substrate. In other words, uneven shapes such as various patterns and bumps are formed on the surface of the substrate.

[0004] If the unevenness of the surface of the substrate is large, the unevenness is not sufficiently absorbed by the adhesive layer when the protective member is attached to the surface of the substrate, and the fixing of the protective member becomes unstable. In addition, the protective member deforms and the surface on the base layer side does not become flat, and the substrate is not supported uniformly by the chuck table of the grinding device. If the substrate is ground in this state, the back surface of the substrate will not become flat.

[0005] Furthermore, since the peripheral excess area of ​​the substrate where no devices are formed does not have patterns or bumps formed and is lower than the device formation area where devices are formed, the protective member cannot be sufficiently attached to the peripheral area of ​​the substrate. Therefore, when the substrate is ground, chipping is likely to occur on the periphery of the substrate. It is possible to attach a protective member with a thick adhesive layer to the surface side of the substrate so that the unevenness of the substrate surface can be sufficiently absorbed, but in this case, when the protective member is finally peeled off from the substrate, residue of the adhesive layer is likely to remain on the unevenness, causing defects in the device chip.

[0006] Therefore, a method was developed in which a resin film without an adhesive layer is brought into close contact with the unevenness of the surface of the substrate, liquid resin is supplied onto the resin film, the liquid resin is pressed with a flat pressing surface via a cover film to spread the liquid resin over the resin film, and then the liquid resin is hardened (see Patent Document 1). With this method, the height difference of the unevenness can be absorbed by the liquid resin, and no residue of the adhesive layer remains on the surface of the substrate. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent Publication No. 2021-27239 Summary of the Invention [Problem to be solved by the invention]

[0008] For example, if the liquid resin is an ultraviolet curable resin, if the liquid resin is irradiated with excessive ultraviolet light when curing the liquid resin, the adhesive strength of the liquid resin decreases and the resin layer formed becomes more likely to peel off. On the other hand, if the amount of ultraviolet light irradiation is too small, the liquid resin does not cure sufficiently. Therefore, it is desirable to irradiate the liquid resin with ultraviolet light under appropriate irradiation conditions.

[0009] Here, unlike the device formation region, no bumps or devices are formed in the peripheral excess region surrounding the device formation region on the surface of the substrate, and therefore the thickness of the resin layer is relatively large. Therefore, when the liquid resin disposed in the device formation region is irradiated with ultraviolet light so as to appropriately harden the liquid resin, the liquid resin outside the device formation region is not sufficiently hardened. The formed resin layer is cut outside the device formation region, but if the resin layer is not sufficiently hardened, the sharpness of the cutter used for cutting is likely to decrease.

[0010] The present invention has been made in consideration of such problems, and its object is to provide a resin coating method and a resin coating apparatus that coat the surface of a substrate with resin by appropriately curing liquid resin supplied to the surface of the substrate as a whole. [Means for solving the problem]

[0011] According to one aspect of the present invention, there is provided a resin coating method for coating one side of a substrate with resin, the resin coating method comprising: a liquid resin supplying step of supplying liquid resin that hardens when irradiated with ultraviolet light to the one side of the substrate; a pressing step of covering the liquid resin supplied to the one side of the substrate with a cover film and spreading the liquid resin with a flat pressing surface through the cover film; a first ultraviolet irradiation step of irradiating the spread liquid resin with ultraviolet light; a second ultraviolet irradiation step of irradiating the liquid resin with ultraviolet light locally along the outer periphery of the substrate before or after the first ultraviolet irradiation step; and a cutting step of cutting the cover film and the liquid resin with a cutter along the outer periphery of the substrate.

[0012] Preferably, the second UV irradiation step is carried out after the first UV irradiation step and simultaneously with the cleaving step.

[0013] Also, preferably, in the second ultraviolet irradiation step, ultraviolet light is irradiated onto the liquid resin outside the outer periphery of the substrate, and in the cutting step, the cover film and the liquid resin are cut outside the outer periphery of the substrate.

[0014] Alternatively, preferably, in the second ultraviolet irradiation step, ultraviolet light is irradiated onto the liquid resin on the one side of the substrate, and in the cutting step, the cover film and the liquid resin are cut on the one side of the substrate.

[0015] According to another aspect of the present invention, there is provided a resin coating apparatus for coating one side of a substrate with resin, the resin coating apparatus comprising: a chuck table for holding the other side of the substrate; a liquid resin supply unit having a nozzle for discharging liquid resin that can be cured by irradiation with ultraviolet light, the liquid resin being supplied from the nozzle to the one side of the substrate held on the chuck table; a pressing unit having a flat pressing surface on its bottom surface and covering the liquid resin supplied to the one side of the substrate by the liquid resin supply unit with a cover film and pressing the liquid resin with the pressing surface through the cover film to spread the liquid resin over the one side of the substrate; a first ultraviolet irradiation unit for irradiating ultraviolet light onto the liquid resin spread by the pressing unit; a second ultraviolet irradiation unit for irradiating ultraviolet light locally along the outer periphery of the substrate; a cutter; and a cutting unit having a moving part for relatively moving the cutter and the substrate along the outer periphery of the substrate, the cutting unit cutting the cover film and the liquid resin with the cutter along the outer periphery of the substrate.

[0016] Preferably, the moving part of the cutting unit further has a support part having a bottom surface to which the second ultraviolet irradiation unit and the cutter are fixed, and a rotational drive source for rotating the support part around a rotation axis perpendicular to the bottom surface of the support part, and by operating the rotational drive source, the second ultraviolet irradiation unit and the cutter can be moved along the outer periphery of the substrate held by the chuck table.

[0017] Also, preferably, the second ultraviolet irradiation unit can irradiate the liquid resin with ultraviolet light outside the outer periphery of the substrate, and the cutting unit can cut the cover film and the liquid resin outside the outer periphery of the substrate.

[0018] Alternatively, preferably, the second ultraviolet irradiation unit can irradiate the liquid resin on the one surface of the substrate with ultraviolet light, and the cutting unit can cut the cover film and the liquid resin on the one surface of the substrate. Effect of the Invention

[0019] In a resin coating method or resin coating apparatus according to one aspect of the present invention, liquid resin that is cured by irradiation with ultraviolet light is supplied to one surface of a substrate, and the liquid resin is spread out with a flat pressing surface. The spread liquid resin is then irradiated with ultraviolet light, and the liquid resin is locally irradiated with ultraviolet light along the outer periphery of the substrate. Therefore, even if the thickness of the liquid resin differs between the device formation region and its outer side, the liquid resin can be appropriately cured in the device formation region while being cured outside the device formation region without losing the sharpness of the cutter.

[0020] Therefore, according to one aspect of the present invention, there is provided a resin coating method and a resin coating apparatus capable of appropriately curing a liquid resin supplied to a surface of a substrate as a whole to coat the surface of the substrate with resin. [Brief description of the drawings]

[0021] [Figure 1] FIG. 1(A) is a perspective view that typically shows a substrate, and FIG. 1(B) is a cross-sectional view that typically shows the substrate. [Diagram 2] FIG. 2A is a cross-sectional view that typically shows the holding step, and FIG. 2B is a cross-sectional view that typically shows the liquid resin supplying step. [Diagram 3] FIG. 3(A) is a cross-sectional view that typically shows a pressing step, and FIG. 3(B) is a cross-sectional view that typically shows a first ultraviolet ray irradiation step. [Figure 4] FIG. 4(A) is a side view that typically shows the second ultraviolet ray irradiation unit and the cutting unit, and FIG. 4(B) is a cross-sectional view that typically shows the second ultraviolet ray irradiation step and the cutting step. [Diagram 5]FIG. 5(A) is a side view showing a schematic diagram of a second ultraviolet irradiation unit and a cutting unit according to a modified example, and FIG. 5(B) is a cross-sectional view showing a schematic diagram of a second ultraviolet irradiation step and a cutting step according to a modified example. [Figure 6] 3 is a flowchart showing the flow of each step of a resin coating method. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] An embodiment according to one aspect of the present invention will be described with reference to the attached drawings. In the resin coating method and resin coating apparatus according to this embodiment, the surface of a substrate such as a semiconductor wafer having a plurality of devices formed on the surface is coated with resin. First, the substrate whose surface is coated with resin will be described. FIG. 1(A) is a perspective view that typically shows the substrate 1, and FIG. 1(B) is a cross-sectional view that typically shows the substrate 1.

[0023] The substrate 1 is, for example, a wafer made of a material such as Si (silicon), SiC (silicon carbide), GaN (gallium nitride), GaAs (gallium arsenide), or other semiconductor material, or a substantially disk-shaped substrate made of a material such as sapphire, glass, or quartz.

[0024] A plurality of mutually intersecting division lines 3 are set on the front surface 1a of the substrate 1. Devices 5 such as ICs (Integrated Circuits) and LSIs (Large Scale Integrations) are formed in each area partitioned by the division lines 3. However, the devices 5 are omitted in the drawings other than FIG. 1(A). The substrate 1 is thinned by grinding from the back surface 1b side, and is divided along the division lines 3 to form individual device chips.

[0025] A plurality of protruding parts called bumps 7 made of metal are provided on the surface 1a of the substrate 1. The bumps 7 are electrically connected to the devices 5, and function as electrodes for inputting and outputting electrical signals to the devices 5 when the substrate 1 is divided into device chips. The bumps 7 are made of a metal material such as gold, silver, copper, or aluminum. However, the bumps 7 do not necessarily have to be provided on the surface 1a of the substrate 1.

[0026] The outer peripheral region surrounding the region on the surface 1a of the substrate 1 where the multiple devices 5 are formed is called the outer peripheral surplus region 11. No devices 5 are formed in the outer peripheral surplus region 11 on the surface 1a of the substrate 1, and no bumps 7 serving as electrodes for the devices 5 are formed either. The region surrounded by the outer peripheral surplus region 11 on the surface 1a of the substrate 1 is called the device formation region 9. The device formation region 9 on the surface 1a of the substrate 1 is not flat, but has irregularities due to the patterns and bumps 7 that make up the devices 5. On the other hand, the outer peripheral surplus region 11 on the surface 1a is flat.

[0027] The substrate 1 whose surface 1a is covered with resin is not limited to this. For example, it may be a package substrate formed by sealing a plurality of devices arranged on a plane with sealing resin. By grinding the sealing resin on the back side of the package substrate to thin the package substrate and dividing the package substrate into individual devices, individual device chips of a predetermined thickness sealed with sealing resin can be formed. Since bumps that become electrodes for the individual devices are formed on the surface of the package substrate, the surface of the package substrate is not flat but has irregularities.

[0028] When the substrate 1 is ground and thinned from the back surface 1b side by a grinding device, a device chip thinned to a predetermined thickness is obtained when the substrate 1 is divided. When the substrate 1 is ground from the back surface 1b side, a protective member is attached to the front surface 1a side in advance to protect the front surface 1a side. Conventionally, when the unevenness of the front surface 1a of the substrate 1 is small, a tape-like protective member made of a base layer and an adhesive layer laminated thereon has been attached to the front surface 1a of the substrate 1. The exposed surface of the protective member attached to the substrate 1 is flat, and when the substrate 1 is placed on a support table with the exposed surface facing downward, the substrate 1 is properly supported.

[0029] However, if the unevenness on the front surface 1a side of the substrate 1 becomes large, the adhesive layer of the protective member cannot fully absorb the unevenness, and the protective member attached to the substrate 1 deforms, causing the exposed surface on the base layer side to become non-flat. In this case, when the substrate 1 is carried into the grinding device, the substrate 1 is not properly supported on the support table, and when the substrate 1 is ground from the back surface 1b side, the back surface 1b of the substrate 1 does not become non-flat. Therefore, it is conceivable to supply liquid resin onto the front surface 1a of the substrate 1 and harden the liquid resin to form the protective member.

[0030] For example, the surface 1a of the substrate 1 is covered with a resin film, liquid resin is supplied onto the resin film, and the liquid resin is pressed from above with a flat pressing surface through the cover film, and then the liquid resin is cured. If an ultraviolet-curable resin is used as the liquid resin, the liquid resin can be cured by ultraviolet light.

[0031] However, if the liquid resin is irradiated with an excessive amount of ultraviolet light, the adhesive strength of the liquid resin decreases, and the resin layer formed becomes more likely to peel off. On the other hand, if the amount of ultraviolet light irradiated is too small, the liquid resin does not harden sufficiently. Therefore, it is desirable to irradiate the liquid resin with ultraviolet light under appropriate irradiation conditions.

[0032] Here, unlike the device formation region 9, in the peripheral surplus region 11 on the surface 1a of the substrate 1, the bumps 7 and devices 5 are not formed, and therefore the thickness of the resin layer is relatively large accordingly. Therefore, when the liquid resin disposed in the device formation region 9 is irradiated with ultraviolet light so as to appropriately harden the liquid resin, the liquid resin does not harden sufficiently in the peripheral surplus region 11. The formed resin layer is cut outside the device formation region 9, but if the resin layer is not sufficiently hardened, the sharpness of the cutter used for cutting is likely to decrease.

[0033] Therefore, in the resin coating method and resin coating apparatus according to this embodiment, the liquid resin is irradiated with ultraviolet rays so that the resin layer formed by curing the liquid resin has a hardness suited to each purpose in the device formation region 9 and the region cut by the cutter. Each step of the resin coating method according to this embodiment will be described below, as well as the resin coating apparatus in which the resin coating method is carried out.

[0034] Fig. 6 is a flow chart for explaining the flow of each step of the resin coating method according to this embodiment. In the resin coating method, first, a holding step S10 is performed in which the substrate 1 is placed on the holding surface of a chuck table with one surface (front surface 1a) of the substrate 1 facing upward, and the substrate 1 is suction-held by the chuck table. Fig. 2(A) is a cross-sectional view showing the holding step S10.

[0035] As shown in FIG. 2(A), the resin coating apparatus 2 includes a chuck table 4 that suction-holds the substrate 1. The upper surface of the chuck table 4 serves as a holding surface 4a that suction-holds the substrate 1. The chuck table 4 includes, for example, a porous member (not shown) exposed to the holding surface 4a, and a suction mechanism (not shown) connected to the porous member. The porous member has a diameter equivalent to that of the substrate 1. When the substrate 1 is placed on the holding surface 4a and the suction mechanism is operated, a negative pressure acts on the substrate 1, and the substrate 1 is suction-held on the chuck table 4.

[0036] In the holding step S10, a resin sheet 13 may be placed on the holding surface 4a before the substrate 1 is placed on the chuck table 4, or the substrate 1 may be placed on the chuck table 4 via the resin sheet 13. The resin sheet 13 is, for example, a polyolefin-based sheet, a polyethylene-based sheet, or the like, and may be a single layer or a laminate. An adhesive layer may be provided on the upper surface of the resin sheet 13, and the adhesive layer of the resin sheet 13 may be attached to the other surface (rear surface 1b) of the substrate 1.

[0037] In the resin coating method according to this embodiment, next, a liquid resin supplying step S20 is performed. Fig. 2(B) is a cross-sectional view that typically shows the liquid resin supplying step S20. As shown in Fig. 2(B), the resin coating apparatus 2 includes a nozzle 8 that ejects liquid resin 15 that can be cured by irradiation with ultraviolet light, and a liquid resin supplying unit 6 that supplies the liquid resin 15 from the nozzle 8 to one surface (front surface 1a) of the substrate 1 held on the chuck table 4. The liquid resin supplying unit 6 is provided at a position adjacent to the chuck table 4 of the resin coating apparatus 2.

[0038] The liquid resin supply unit 6 has a pipe-shaped liquid supply path with a nozzle 8 at its tip. This liquid supply path includes a rotatable shaft (not shown) that extends along a direction perpendicular to the holding surface 4a outside the chuck table 4, and an arm that extends from the upper end of the shaft in a direction parallel to the holding surface 4a. A liquid resin supply source (not shown) is connected to the base end side of the shaft, and a nozzle 8 is provided at the tip of the arm.

[0039] When the shaft of the liquid resin supplying unit 6 is rotated, the nozzle 8 moves along an arc-shaped path with the arm as the radius. The nozzle 8 can move between above the chuck table 4 and the outside of the chuck table 4. The length of the arm is set to a length that allows the nozzle 8 to be positioned above the center of the chuck table 4 by rotating the shaft.

[0040] In the liquid resin supply step S20, the nozzle 8 is positioned above the center of the holding surface 4a of the chuck table 4, i.e., above the center of one surface (surface 1a) of the substrate 1. Then, liquid resin 15 that is cured by irradiation with ultraviolet light is supplied to one surface (surface 1a) of the substrate 1. FIG. 2(B) shows a schematic cross-sectional view of the liquid resin 15 supplied to the substrate 1.

[0041] Here, liquid resin 15 is supplied to substrate 1 in an amount that will form a resin layer of sufficient thickness when it is pressed from above, spread, and cured by irradiation with ultraviolet light, as described below. After liquid resin 15 has been supplied to one surface (front surface 1a) of substrate 1, the shaft of liquid resin supply unit 6 is rotated again to position nozzle 8 at a position where it does not overlap chuck table 4.

[0042] In the resin coating method according to the present embodiment, a pressing step S30 is then performed. Fig. 3(A) is a cross-sectional view showing a schematic diagram of the pressing step S30. In the pressing step S30, the liquid resin 15 supplied to one surface (front surface 1a) of the substrate 1 is covered with a cover film 17, and the liquid resin 15 is pressed and spread by the flat pressing surface 10a through the cover film 17.

[0043] Here, the pressing unit 12 provided in the resin coating device 2 will be described. The pressing unit 12 is disposed above the chuck table 4. FIG. 3(A) includes a cross-sectional view showing the pressing unit 12 in schematic form. The pressing unit 12 includes a pressing section 10 that presses the liquid resin 15 from above. The pressing section 10 can be raised and lowered by a lifting mechanism (not shown). The pressing section 10 has a flat pressing surface 10a on its lower surface (bottom surface). The pressing surface 10a is oriented with high precision so as to be parallel to the holding surface 4a of the chuck table 4.

[0044] The pressing part 10 can hold the cover film 17 on the pressing surface 10a. The pressing unit 12 lowers the pressing part 10 with the cover film 17 held on the pressing surface 10a, and presses the liquid resin 15 from above with the pressing surface 10a through the cover film 17. Thereafter, when the liquid resin 15 is cured by the first ultraviolet irradiation unit 14 described below, the hardened liquid resin 15 and the cover film 17 are integrated to form a protective member. In other words, the cover film 17 is a member that constitutes the protective member.

[0045] Here, the pressing unit 10 includes a holding mechanism (not shown) for holding the cover film 17 on the pressing surface 10a. For example, the pressing surface 10a is provided with a plurality of suction holes connected to a suction source, and the cover film 17 is held on the pressing surface 10a by sucking the cover film 17 through the suction holes. Alternatively, the pressing unit 10 may include an electrostatic chuck mechanism in the vicinity of the pressing surface 10a, and the electrostatic chuck mechanism may be operated to hold the cover film 17 on the pressing surface 10a by electrostatic force.

[0046] Alternatively, the pressing unit 10 may not have a holding mechanism. In this case, for example, an adhesive layer may be provided on the upper surface of the cover film 17, and the cover film 17 may be adhered to the pressing surface 10a by the adhesive layer. Alternatively, an adhesive may be applied to the upper surface or the pressing surface 10a of the cover film 17, and the cover film 17 may be held to the pressing surface 10a by the adhesive.

[0047] In the pressing step S30, the pressing unit 10 holding the cover film 17 on the pressing surface 10a is lowered, and the liquid resin 15 is pressed by the pressing surface 10a through the cover film 17. Fig. 3(A) shows a schematic cross-sectional view of the substrate 1, the resin sheet 13, the liquid resin 15, and the cover film 17 when the liquid resin 15 is pressed by the pressing surface 10a. When the liquid resin 15 is pressed by the pressing surface 10a, the liquid resin 15 is spread out toward the outer periphery of the substrate 1.

[0048] In this way, the pressing unit 12 has the function of covering the liquid resin 15 supplied by the liquid resin supply unit 6 with the cover film 17 and pressing the liquid resin 15 with the pressing surface 10a through the cover film 17, thereby spreading the liquid resin 15 onto the substrate 1.

[0049] Here, in the liquid resin supplying step S20, it is preferable that a slightly excess amount of liquid resin 15 is supplied to the substrate 1 so that the liquid resin 15 is sufficiently spread over the entire surface of one side (front surface 1a) of the substrate 1 with a thickness equal to or greater than the required thickness. Then, in the pressing step S30, the pressing unit 10 is lowered to a predetermined height so that the protective member is finally provided on the substrate 1 with the required thickness. At this time, the excess liquid resin 15 overflows outside the outer periphery 1c of the substrate.

[0050] If a resin sheet 13 is laid below the substrate 1 in advance, the overflowing excess liquid resin 15 is received by the resin sheet 13. Therefore, the liquid resin 15 does not come into contact with the holding surface 4a of the chuck table 4 and soil the holding surface 4a.

[0051] Next, a first ultraviolet irradiation step S40 is performed in which ultraviolet rays are irradiated onto the liquid resin 15 spread in the pressing step S30. Fig. 3(B) is a cross-sectional view showing the first ultraviolet irradiation step S40. First, the first ultraviolet irradiation unit 14 of the resin coating apparatus 2 that irradiates ultraviolet rays onto the liquid resin 15 in the first ultraviolet irradiation step S40 will be described.

[0052] The first ultraviolet irradiation unit 14 includes an ultraviolet light source such as an ultraviolet LED or an ultraviolet fluorescent lamp, and is attached to the pressing part 10 of the pressing unit 12. For example, the pressing part 10 is made of a hard material that transmits ultraviolet light, and a plurality of first ultraviolet irradiation units 14 are provided on the upper surface of the pressing part 10. For ease of explanation, hatching that should be applied to the area showing the pressing part 10 is omitted in Figures 3(A) and 3(B).

[0053] The first ultraviolet irradiation unit 14 irradiates the liquid resin 15 spread by the pressing unit 12 with ultraviolet light through the pressing part 10 to harden the liquid resin 15. Here, the liquid resin 15 spread by the pressing unit 12 has a different thickness in the device formation region 9 and the peripheral excess region 11 of the substrate 1. In the first ultraviolet irradiation step S40, the liquid resin 15 is irradiated with ultraviolet light with an intensity suitable for hardening the liquid resin 15 disposed mainly in the device formation region 9.

[0054] For example, in the first ultraviolet irradiation step S40, the first ultraviolet irradiation unit 14 irradiates ultraviolet light having a wavelength of 365 nm at 80 mW / cm 2 The entire surface of the substrate 1 is irradiated with ultraviolet light for about 10 seconds at an irradiation intensity (illuminance) of about 100 nm. However, the irradiation conditions of the ultraviolet light are not limited to these and can be appropriately adjusted depending on the type and thickness of the liquid resin 15.

[0055] Thereafter, the first ultraviolet irradiation unit 14 is stopped, the pressing part 10 is raised, and the pressing unit 12 is retracted from above the chuck table 4, leaving the cover film 17 on the cured liquid resin 15. That is, a protective member in which the cured liquid resin 15 and the cover film 17 are integrated is formed on one surface (front surface 1a) of the substrate 1. Here, since the holding surface 4a and the pressing surface 10a of the chuck table 4 are parallel to each other, the back surface 1b of the substrate 1 and the upper surface of the protective member are parallel to each other.

[0056] In the resin coating method according to the present embodiment, the first ultraviolet ray irradiation step S40 is followed by the second ultraviolet ray irradiation step S50, and then the cutting step S60. Fig. 4(A) is a cross-sectional view showing a schematic state before the second ultraviolet ray irradiation step S50 and the cutting step S60 are performed, and Fig. 4(B) is a cross-sectional view showing a schematic state of the second ultraviolet ray irradiation step S50 and the cutting step S60.

[0057] The resin coating apparatus 2 includes a second ultraviolet ray irradiation unit 28 used in the second ultraviolet ray irradiation step S50, and a cutting unit 20 used in the cutting step S60. The resin coating apparatus 2 includes, for example, a holding table 16 different from the chuck table 4. The substrate 1 on which the cured liquid resin 15 is disposed is transferred from the chuck table 4 to the upper surface 16a of the holding table 16, and the second ultraviolet ray irradiation step S50 and the cutting step S60 are performed on the holding table 16.

[0058] Here, the second ultraviolet irradiation unit 28 and the cutting unit 20 will be described. The second ultraviolet irradiation unit 28 is incorporated into the cutting unit 20 for use as described below. The second ultraviolet irradiation unit 28 can be raised and lowered together with the cutting unit 20 by a lifting mechanism (not shown).

[0059] The cutting unit 20 has a cutter 26 and a moving part that relatively rotates and moves the cutter 26 and the substrate 1 along the outer periphery 1c of the substrate 1. The moving part of the cutting unit 20 has, for example, a support part 24 to the bottom surface of which the second ultraviolet irradiation unit 28 and the cutter 26 are fixed, and a rotation drive source (not shown) such as a motor that rotates the support part 24 around a rotation axis 22 perpendicular to the bottom surface of the support part 24. The rotation drive source may rotate the holding table 16 instead of the support part 24.

[0060] The cutter 26 is a sharp blade made of a metal material such as stainless steel. By operating the rotary drive source of the moving part, the cutter 26 can be moved along the outer periphery 1c of the substrate 1. For example, the cutter 26 is fixed to the support part 24 at a predetermined position so that the radius of the circular orbit of the cutter 26, which rotates and moves by operating the rotary drive source, is larger than the radius of the substrate 1. Here, the length of the cutter 26 extending downward from the support part 24 is longer than the thickness of the substrate 1 including the cured liquid resin 15, for example.

[0061] The second ultraviolet ray irradiation unit 28 is fixed to the support part 24, for example, outside the cutter 26. In this case, when the rotary drive source is operated, the second ultraviolet ray irradiation unit 28 rotates and moves outside the cutter 26 along the outer periphery 1c of the substrate 1. The second ultraviolet ray irradiation unit 28 is, for example, an ultraviolet ray LED. In the second ultraviolet ray irradiation step S50, ultraviolet rays are locally irradiated onto the liquid resin 15 along the outer periphery 1c of the substrate 1.

[0062] Although the liquid resin 15 has already been irradiated with ultraviolet light in the first ultraviolet light irradiation step S40, the liquid resin 15 is thick outside the device formation region 9 on one side (front surface 1a) of the substrate 1, and therefore the liquid resin 15 has not yet cured sufficiently. If an attempt is made to cut the liquid resin 15 outside the device formation region 9 with the cutter 26 in this state, a high load will be placed on the cutter 26, causing it to wear out rapidly and quickly losing its cutting ability. In this case, it will be necessary to replace the cutter 26 promptly.

[0063] Therefore, in the second ultraviolet irradiation step S50, the second ultraviolet irradiation unit 28 locally irradiates ultraviolet rays along the outer periphery 1c of the substrate 1 so that the liquid resin 15 is sufficiently cured in the portion cut by the cutter 26. The second ultraviolet irradiation step S50 is performed by operating the rotary drive source to rotate the rotary shaft 22 and operating the second ultraviolet irradiation unit 28 while rotating and moving the second ultraviolet irradiation unit 28.

[0064] The intensity of the ultraviolet light irradiated to the liquid resin 15 in the second ultraviolet light irradiation step S50 is determined so that the liquid resin 15 is sufficiently cured outside the device formation region 9. More specifically, the intensity of the ultraviolet light in the second ultraviolet light irradiation step S50 is preferably determined so that the liquid resin 15 in that portion is appropriately cured by the ultraviolet light irradiated in the first ultraviolet light irradiation step S40 and the ultraviolet light irradiated in the second ultraviolet light irradiation step S50.

[0065] For example, in the second ultraviolet irradiation step S50, the second ultraviolet irradiation unit 28 irradiates the liquid resin 15 with ultraviolet light having a wavelength of 365 nm at 80 mW / cm. 2 The liquid resin 15 is irradiated with ultraviolet light at an irradiation intensity (illuminance) of about 10° / sec. Here, the rotating shaft 22 is rotated at a rotation speed of about 10° / sec, and the rotating shaft 22 is rotated through an angle of 360° or more. More preferably, the rotating shaft 22 is rotated 380°. However, the irradiation conditions of the ultraviolet light are not limited to these and are appropriately adjusted depending on the type, thickness, etc. of the liquid resin 15.

[0066] Next, the cutting step S60 will be described. In the cutting step S60, the cover film 17 and the liquid resin 15 are cut by the cutter 26 along the outer periphery 1c of the substrate 1. In the cutting step S60, first, the cutting unit 20 is lowered to cause the cutter 26 to cut into the cover film 17 and the liquid resin 15.

[0067] Here, if a resin sheet 13 is laid on the other surface (rear surface 1b) of the substrate 1, the resin sheet 13 is also cut by the cutter 26 in the cutting step S60. At this time, it is preferable that an annular clearance groove 18 having a diameter equal to that of the substrate 1 is provided on the upper surface 16a of the holding table 16 so that the tip (lower end) of the cutter 26 cutting into the resin sheet 13 does not come into contact with the upper surface 16a of the holding table 16. In this case, the cutter 26 cutting into the resin sheet 13 advances into the clearance groove 18 and does not come into contact with the holding table 16.

[0068] In addition, in the chuck table 4 on which the liquid resin supplying step S20, the pressing step S30, and the first ultraviolet ray irradiation step S40 have been performed, a clearance groove corresponding to the clearance groove 18 of the holding table 16 may be provided in the holding surface 4a. In this case, the second ultraviolet ray irradiation step S50 and the cutting step S60 may be performed on the chuck table 4, and the resin coating device 2 may not be equipped with the holding table 16.

[0069] In the cutting step S60, the cutter 26 is lowered to cut into the cover film 17 and the liquid resin 15, and then the rotary drive source connected to the upper end of the rotating shaft 22 is operated to rotate the cutter 26 along the outer periphery 1c of the substrate 1. Then, the cutter 26 cuts the cover film 17 and the liquid resin 15 along the outer periphery 1c of the substrate 1 outside the outer periphery 1c, and the unnecessary portion of the liquid resin 15 is cut off. Then, the substrate 1 is obtained whose surface 1a is covered with the resin (cured liquid resin 15) that serves as the protective member.

[0070] In the resin coating method according to this embodiment, the second ultraviolet ray irradiation step S50 is performed, so that the liquid resin 15 is sufficiently cured in advance in the portion cut by the cutter 26 in the cutting step S60. That is, the entire liquid resin 15 supplied to one side (surface 1a) of the substrate 1 is appropriately cured, and the resin coats the surface 1a of the substrate 1. Therefore, an excessive load is not applied to the cutter 26 cutting into the liquid resin 15, and the cutting ability of the cutter 26 is easily maintained.

[0071] The second ultraviolet ray irradiation step S50 may be performed after the first ultraviolet ray irradiation step S40 and simultaneously with the cutting step S60. Fig. 4(B) is a cross-sectional view showing a schematic diagram of a case where the cutting step S60 is performed simultaneously with the second ultraviolet ray irradiation step S50.

[0072] In this case, the second ultraviolet irradiation unit 28 is operated to irradiate the liquid resin 15 with ultraviolet rays, while the cutting unit 20 is lowered to cause the cutter 26 to cut into the liquid resin 15. Then, while the second ultraviolet irradiation unit 28 is operated, the rotary drive source connected to the upper end of the rotating shaft 22 is operated to rotate the cutter 26 along the outer periphery 1c of the substrate 1, thereby cutting the liquid resin 15.

[0073] Depending on the type and properties of the ultraviolet curable resin that is the material of the liquid resin 15, the liquid resin 15 is instantly cured when irradiated with ultraviolet rays. Therefore, even when the second ultraviolet irradiation unit 28 irradiates the liquid resin 15 with ultraviolet rays and the cutter 26 cuts the liquid resin 15 at substantially the same time, the liquid resin 15 that is in an appropriately cured state is cut by the cutter 26. This reduces the load on the cutter 26. If the second ultraviolet irradiation step S50 and the cutting step S60 can be performed simultaneously, the rotation drive source that rotates the rotating shaft 22 only needs to be operated once, improving work efficiency.

[0074] So far, a description has been given of a case in which in the second ultraviolet ray irradiation step S50, ultraviolet rays are irradiated onto the liquid resin 15 outside the outer periphery 1c of the substrate 1, and in the cutting step S60, the cover film 17 and the liquid resin 15 are cut outside the outer periphery 1c of the substrate 1. However, the second ultraviolet ray irradiation step S50 and the cutting step S60 are not limited to this.

[0075] For example, in the second ultraviolet ray irradiation step S50, ultraviolet rays may be irradiated onto the liquid resin 15 on one surface (surface 1a) of the substrate 1, and in the cutting step S60, the cover film 17 and the liquid resin 15 may be cut on one surface (surface 1a) of the substrate 1. Next, the second ultraviolet ray irradiation step S50 and the cutting step S60 according to a modified example will be described, and the cutting unit 20a and the second ultraviolet ray irradiation unit 28a according to the modified example will be described.

[0076] Fig. 5(A) is a side view showing a cutting unit 20a and a second ultraviolet irradiation unit 28a according to a modified example, and Fig. 5(B) is a cross-sectional view showing a second ultraviolet irradiation step S50 and a cutting step S60 according to a modified example. In the following description, changes from the above-mentioned respective embodiments will be mainly described. Therefore, the above description can be appropriately referred to for other points.

[0077] In the cutting unit 20a according to the modified example, the cutter 26a is fixed to the support part 24 at a predetermined position so that the radius of the annular orbit of the cutter 26a, which rotates when the rotary drive source is operated, is smaller than the radius of the substrate 1. More specifically, the cutter 26a is fixed to the support part 24 so that the radius of the annular orbit of the cutter 26a, which rotates, is smaller than the radius of the substrate 1 and larger than the radius of the device formation region 9 on the surface 1a of the substrate 1.

[0078] In cutting unit 20a according to the modified example, cutter 26a extending downward from support portion 24 has a length exceeding the sum of the thickness of hardened liquid resin 15 in peripheral excess region 11 and the thickness of cover film 17. When cutter 26 is lowered toward peripheral excess region 11 on one surface (surface 1a) of substrate 1 to cut into liquid resin 15 and rotating shaft 22, cover film 17 and liquid resin 15 on one surface (surface 1a) of substrate 1 can be cut.

[0079] The second ultraviolet ray irradiation unit 28a according to the modified example is fixed to the support portion 24 so as to be able to irradiate the liquid resin 15 in the peripheral excess area 11 on one surface (front surface 1a) of the substrate 1 with ultraviolet rays.

[0080] When the second ultraviolet ray irradiation step S50 and the cutting step S60 according to the modified example are performed simultaneously, first, the second ultraviolet ray irradiation unit 28a is operated to irradiate one area of ​​the outer circumferential excess area 11 with ultraviolet rays while the cutting unit 20a is lowered. Then, the cutter 26a is caused to cut into the area where the liquid resin 15 has been hardened by the ultraviolet rays. At this time, the lower end of the cutter 26a is caused to reach the surface 1a of the substrate 1 or its vicinity.

[0081] Thereafter, while continuing the operation of the second ultraviolet irradiation unit 28a, the rotary drive source connected to the rotary shaft 22 is operated to rotate and move the cutter 26a on the circular orbit. Then, the liquid resin 15 on one surface of the substrate 1 is cut along the outer periphery 1c of the substrate 1, and the excess portion of the liquid resin 15 is cut off. As a result, the surface 1a of the substrate 1 is covered with a protective member constituted by the hardened liquid resin 15 and the cover film 17.

[0082] Here, in the cutting step S60 according to the modified example, the cutter 26a does not advance below the rear surface 1b of the substrate 1. Therefore, the holding table 16 does not need to have the escape groove 18 described in Figures 4(A) and 4(B). Furthermore, when the second ultraviolet ray irradiation step S50 and the cutting step S60 are performed, it is not necessary to move the substrate 1 from the chuck table 4 on which the substrate 1 was held when the first ultraviolet ray irradiation step S40 and the like are performed.

[0083] That is, the resin coating apparatus 2 does not need to have a holding table 16 in addition to the chuck table 4, and does not need to have a transport unit or the like for moving the substrate 1 from the chuck table 4 to the holding table 16. In this case, the configuration of the resin coating apparatus 2 can be significantly simplified, and the manufacturing costs, operating costs, maintenance costs, etc. of the resin coating apparatus 2 can be reduced.

[0084] Moreover, in the cutting step S60 according to the modified example, the cutter 26a cuts into the hardened liquid resin 15 in the outer peripheral excess region 11 of the surface 1a of the substrate 1, so that in the liquid resin supplying step S20, it is not necessary to supply the liquid resin 15 to the substrate 1 in an amount that completely covers the surface 1a of the substrate 1. For example, in the liquid resin supplying step S20, the liquid resin 15 may be supplied to the substrate 1 in an amount that does not cause the liquid resin 15 to overflow outside the outer periphery 1c of the substrate 1 when the liquid resin 15 is pressed from above by the pressing unit 12 in the pressing step S30.

[0085] If the liquid resin 15 does not overflow outside the outer periphery 1c of the substrate 1 in the pressing step S30, there is no need to previously lay a resin sheet 13 used to catch the overflowing liquid resin 15 on the back surface 1b of the substrate 1. If the resin sheet 13 is not used, there is no need to peel off the resin sheet 13 when processing the substrate 1 from the back surface 1b side after covering the front surface 1a of the substrate 1 with a protective member composed of the cured liquid resin 15 and the cover film 17.

[0086] As described above, according to the resin coating method and resin coating apparatus 2 of this embodiment, the liquid resin 15 supplied to the surface 1a of the substrate 1 can be appropriately cured as a whole to coat the surface 1a of the substrate 1 with resin. Therefore, in the first ultraviolet irradiation step S40, the liquid resin 15 in the device formation region 9 can be irradiated with ultraviolet rays under conditions that allow the liquid resin 15 to be appropriately cured without considering the hardness, etc., of the liquid resin 15 in other parts. In other words, the adhesion strength of the liquid resin 15 in the device formation region 9 to the surface 1a can be highly controlled.

[0087] Conventionally, a resin film is adhered to the surface 1a of the substrate 1 in advance, and then liquid resin is supplied onto the resin film and cured to ensure an appropriate adhesion strength between the surface 1a and the resin film (liquid resin). In contrast, in the resin coating method according to the present embodiment, the adhesion strength of the liquid resin 15 to the surface 1a of the substrate 1 can be controlled, so that the adhesion step of the resin film that was adhered to the surface 1a of the substrate 1 in the past, the configuration for realizing the adhesion step, and the resin film itself can be omitted.

[0088] In the above embodiment, the case where the second ultraviolet ray irradiation step S50 is performed after the first ultraviolet ray irradiation step S40 has been described. That is, the case where the liquid resin 15 is irradiated with ultraviolet rays by the first ultraviolet ray irradiation unit 14, and then the liquid resin 15 is irradiated with ultraviolet rays by the second ultraviolet ray irradiation unit 28, 28a has been described. However, the resin coating method and resin coating apparatus 2 according to one aspect of the present invention are not limited to this.

[0089] That is, in the resin coating method and resin coating apparatus 2 according to one aspect of the present invention, the first ultraviolet ray irradiation step S40 may be performed after the second ultraviolet ray irradiation step S50 is performed. In other words, the liquid resin 15 may be irradiated with ultraviolet rays by the first ultraviolet ray irradiation unit 14 after the second ultraviolet ray irradiation unit 28, 28a irradiates the liquid resin 15 with ultraviolet rays.

[0090] Even in this case, the ultraviolet rays can be irradiated with an intensity sufficient to appropriately harden the liquid resin 15 in both the device formation region 9 having an uneven shape and the peripheral excess region 11 where the liquid resin 15 is thick. Therefore, the entire surface 1a of the substrate 1 can be covered with the appropriately hardened liquid resin 15.

[0091] In addition, the structures, methods, and the like according to the above-described embodiments and modified examples can be modified as appropriate without departing from the scope of the present invention. [Explanation of symbols]

[0092] 1 Board 1a surface 1b back side 1c outer circumference 3. Planned division line 5 Devices 7. Bump 9 Device formation area 11 Surplus outer area 13 Resin sheet 15 Liquid resin 17 Cover film 2 Resin coating equipment 4 Chuck table 4a Holding surface 6 Liquid resin supply unit 8 Nozzles 10 Pressing section 10a Pressing surface 12 Pressing unit 14 First ultraviolet irradiation unit 16 Holding table 16a Top side 18 Relief Groove 20,20a Cutting unit 22 Rotation axis 24 Support part 26,26a Cutter 28, 28a Second ultraviolet irradiation unit

Claims

1. A resin coating method for coating one surface of a substrate with a resin, comprising the steps of: a liquid resin supplying step of supplying a liquid resin that is cured by irradiation with ultraviolet light onto the one surface of the substrate; a pressing step of covering the liquid resin supplied to the one surface of the substrate with a cover film and pressing and spreading the liquid resin with a flat pressing surface through the cover film; a first ultraviolet irradiation step of irradiating the spread liquid resin with ultraviolet light; a second ultraviolet irradiation step of locally irradiating the liquid resin with ultraviolet light along an outer periphery of the substrate before or after the first ultraviolet irradiation step; a cutting step of cutting the cover film and the liquid resin along the outer periphery of the substrate with a cutter.

2. 2. The resin coating method according to claim 1, wherein the second ultraviolet ray irradiation step is carried out after the first ultraviolet ray irradiation step and simultaneously with the cutting step.

3. In the second ultraviolet ray irradiation step, ultraviolet rays are irradiated onto the liquid resin outside the outer periphery of the substrate; 3. The resin coating method according to claim 1, wherein in the cutting step, the cover film and the liquid resin are cut outside the outer periphery of the substrate.

4. In the second ultraviolet irradiation step, ultraviolet light is irradiated onto the liquid resin on the one surface of the substrate; 3. The resin coating method according to claim 1, wherein in the cutting step, the cover film and the liquid resin are cut on the one surface of the substrate.

5. A resin coating device for coating one surface of a substrate with resin, comprising: a chuck table that holds the other surface of the substrate; a liquid resin supply unit including a nozzle for discharging a liquid resin that can be cured by irradiation with ultraviolet light, the liquid resin being supplied from the nozzle to the one surface of the substrate held on the chuck table; a pressing unit having a flat pressing surface on a bottom surface thereof, which covers the liquid resin supplied to the one surface of the substrate by the liquid resin supply unit with a cover film and presses the liquid resin with the pressing surface through the cover film to spread the liquid resin over the one surface of the substrate; a first ultraviolet irradiation unit that irradiates the liquid resin spread by the pressing unit with ultraviolet light; a second ultraviolet irradiation unit that locally irradiates ultraviolet light along an outer periphery of the substrate; A resin coating apparatus comprising: a cutter; a moving part which moves the cutter and the substrate relatively along the outer periphery of the substrate; and a cutting unit which cuts the cover film and the liquid resin with the cutter along the outer periphery of the substrate.

6. The moving part of the cutting unit further includes a support part having a bottom surface to which the second ultraviolet irradiation unit and the cutter are fixed, and a rotation drive source that rotates the support part around a rotation axis perpendicular to the bottom surface of the support part, 6. The resin coating apparatus according to claim 5, wherein the second ultraviolet ray irradiation unit and the cutter can be moved along the outer periphery of the substrate held by the chuck table by operating the rotary drive source.

7. the second ultraviolet irradiation unit is capable of irradiating the liquid resin with ultraviolet light outside the outer periphery of the substrate; 7. The resin coating apparatus according to claim 5, wherein the cutting unit is capable of cutting the cover film and the liquid resin outside the outer periphery of the substrate.

8. the second ultraviolet irradiation unit is capable of irradiating the liquid resin on the one surface of the substrate with ultraviolet light; 7. The resin coating method according to claim 5, wherein the cutting unit is capable of cutting the cover film and the liquid resin on the one surface of the substrate.

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