Mask formation method

Abstract

To provide a mask forming method which solves a problem that a work of arranging masks each having the size corresponding to each chip every chip is time-consuming and troublesome.SOLUTION: A method for forming a mask to be used when applying metal plating to dividing scheduled lines of a substrate to be divided into individual chips along the dividing scheduled lines includes a mask sheet preparation step of preparing a mask sheet which has a size corresponding to the substrate and has a surface that can be attached to the upper surface of the substrate, a groove forming step of forming grooves by positioning a cutting blade on the surface of the mask sheet according to the dividing scheduled lines, a sheet adhering step of making the upper surface of the substrate and the surface of the mask sheet face each other, and adhering the surface of the mask sheet to the upper surface of the substrate while the grooves are caused to correspond to the dividing scheduled lines, and a groove exposing step of thinning the back side of the mask sheet to expose the grooves to the back side.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a method for forming a mask used when metal plating is performed along the division lines of a substrate to be divided into individual chips by the division lines. [Background technology]

[0002] Wafers, on the surface of which multiple devices such as ICs and LSIs are formed and partitioned along planned dividing lines, are cut by a cutting machine equipped with a rotatable cutting blade to separate them into individual device chips, which are then used in electrical equipment such as mobile phones and personal computers.

[0003] The above-mentioned cutting device is also used when dividing a ceramic substrate having a surface divided into multiple regions by planned division lines into individual chips for each region (see, for example, Patent Document 1). However, before the cutting process is performed, a grid-like AuSn (gold-tin) plating having a width exceeding the thickness of the cutting blade that divides the ceramic substrate is applied along the planned division lines. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-039906 Summary of the Invention [Problem to be solved by the invention]

[0005] However, as mentioned above, in order to apply AuSn plating in a grid pattern along the intended dividing line with a width exceeding the thickness of the cutting blade, it is necessary to arrange a mask of a size corresponding to each chip for each chip, which is an unbearable hassle. This causes the following problem.

[0006] The present invention has been made in consideration of the above facts, and its main technical object is to provide a method for forming a mask that solves the problem that the work of arranging a mask of a size corresponding to each individual chip for each chip is time-consuming and cumbersome. [Means for solving the problem]

[0007] In order to solve the above-mentioned main technical problem, according to the present invention, there is provided a method for forming a mask used when applying metal plating to the planned division lines of a substrate to be divided into individual chips by the planned division lines, the method comprising: a mask sheet preparation step of preparing a mask sheet having a size corresponding to the substrate and a surface that can be attached to the upper surface of the substrate; a groove formation step of positioning a cutting blade on the surface of the mask sheet corresponding to the planned division lines to form grooves; a sheet attachment step of bringing the upper surface of the substrate and the surface of the mask sheet face to face and attaching the surface of the mask sheet to the upper surface of the substrate with the grooves corresponding to the planned division lines; and a groove exposure step of thinning the back side of the mask sheet to expose the grooves on the back side.

[0008] In the mask sheet preparation step, a UV sheet having an adhesive layer on its surface whose adhesive strength is reduced by irradiation with ultraviolet light may be prepared as the mask sheet. Also, in the mask sheet preparation step, a thermocompression sheet that is pressure-bonded by heating may be prepared as the mask sheet. [Effects of the Invention]

[0009] The mask forming method of the present invention is a method for forming a mask used when applying metal plating to the planned division lines of a substrate to be divided into individual chips by the planned division lines, and includes the following steps: a mask sheet preparation step of preparing a mask sheet that is sized to correspond to the substrate and has a surface that can be attached to the upper surface of the substrate; a groove forming step of positioning a cutting blade on the surface of the mask sheet to correspond to the planned division lines and form grooves; a sheet attachment step of bringing the upper surface of the substrate and the surface of the mask sheet face to face and attaching the surface of the mask sheet to the upper surface of the substrate with the grooves corresponding to the planned division lines; and a groove exposing step of thinning the back side of the mask sheet to expose the grooves on the back side.Therefore, grooves are formed in advance in the mask sheet to be attached to the substrate corresponding to the planned division lines of the substrate, and masks of sizes corresponding to the individual chips can be easily arranged, eliminating the need to arrange masks of sizes corresponding to the individually divided chips for each chip, which is a hassle.

[0010] Furthermore, as in the prior art, when a mask sheet is attached to a substrate and then grooves are formed in the mask sheet using a cutting blade, there is a risk that the cutting blade will scratch the substrate. However, according to the present invention, grooves are formed in the mask sheet in advance, thereby avoiding scratching the substrate. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is an overall perspective view of a cutting device suitable for this embodiment. [Figure 2] FIG. 2A is a perspective view of a substrate that is a workpiece, and FIG. 2B is a perspective view of a mask sheet prepared in a mask sheet preparation step. [Figure 3] (a) is a perspective view showing an embodiment of a groove forming step, (b) is an enlarged cross-sectional view of a portion of a mask sheet in which grooves have been formed, and (c) is an overall perspective view of a mask sheet in which the groove forming step has been carried out. [Figure 4] FIG. 10(a) is a perspective view showing an embodiment of a sheet adhering step, and FIG. 10(b) is a perspective view showing an embodiment of removing the substrate and mask sheet from the chuck table. [Figure 5]FIG. 10A is a perspective view showing how a substrate and a mask sheet are placed on a holding table; FIG. 10B is a perspective view showing an embodiment of a groove exposing step; and FIG. 10C is a perspective view showing another embodiment of a groove exposing step. [Figure 6] FIG. 1(a) is a partially enlarged cross-sectional view of a substrate and a mask sheet that have been subjected to a groove exposing step, and FIG. 1(b) is an overall perspective view of a substrate and a mask sheet that have been subjected to a groove exposing step. [Figure 7] 1A to 1C are perspective views showing an embodiment of a dividing step of dividing a substrate into individual chips, and partially enlarged cross-sectional views showing the dividing step in action. DETAILED DESCRIPTION OF THE INVENTION

[0012] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a method for forming a mask according to the present invention will be described in detail with reference to the accompanying drawings.

[0013] 1 shows a cutting apparatus 1 capable of cutting a substrate 10 shown in the figure and capable of performing cutting suitable for carrying out the mask forming method of this embodiment. The cutting apparatus 1 includes a substantially rectangular parallelepiped housing 2, a cassette 4 placed on a cassette table 4a of the housing 2, a carry-in / out means 3 for carrying out unprocessed substrates 10 supported on a frame F from the cassette 4 to a temporary storage table 5 and for carrying processed substrates 10 placed on the temporary storage table 5 into the cassette 4, a transport means 6 having a swivel arm for transporting the substrates 10 carried out to the temporary storage table 5 to a chuck table 7, a cutting means 8 for cutting the substrates 10 held on the chuck table 7, an imaging means 9 for capturing an image of the substrate 10 held on the chuck table 7, a cleaning / unloading means 17 for transporting the processed substrates 10 from the carry-in / out position where the chuck table 7 is positioned in FIG. 1 to a cleaning apparatus 16 (details of which are omitted), and a control means (not shown). The cutting means 8 can be replaced with different cutting blades (for example, cutting blades 81A and 81B having different thicknesses and materials) depending on the material of the workpiece and cutting processing conditions.

[0014] The substrate 10 cut by the cutting device 1 of this embodiment is a ceramic substrate, and as shown in an enlarged view in FIG. 2( a), it is a rectangular substrate having a plurality of regions 12 defined on the surface 10 a by dividing lines 14. The dividing lines 14 are formed in a grid pattern by dividing lines 14 in a predetermined direction and dividing lines 14 in a direction perpendicular to the predetermined dividing lines 14. When dividing the substrate 10 into individual chips for each region 12 using the cutting device 1, the substrate 10 is supported on an annular frame F via protective tape T and held on a chuck table 7, as shown in FIG. 1. The substrate 10 cut by the cutting means 8 is not limited to the above-described form, and may have a form in which the regions 12 and dividing lines 14 are covered with a mold resin and are not exposed on the surface 10 a.

[0015] The cutting device 1 includes an X-axis moving means for relatively moving the chuck table 7 and the cutting means 8 in the X-axis direction, and a Y-axis moving means for relatively moving the chuck table 7 and the cutting means 8 in the Y-axis direction, which is perpendicular to the X-axis direction. In this embodiment, the X-axis moving means is a means for moving the chuck table 7 in the X-axis direction, and the Y-axis moving means is a means for moving the cutting means 8 in the Y-axis direction. The X-axis moving means and Y-axis moving means described above are disposed inside the housing 2 and are not shown in the figure.

[0016] The chuck table 7 includes a suction chuck 71 that forms the holding surface of the chuck table 7, and clamps 72 that are disposed opposite the outer periphery of the chuck table 7 and grip a frame F that supports the substrate 10. The suction chuck 71 is made of a breathable material and is connected to a suction source (not shown). By operating the suction source, a negative pressure is generated on the holding surface of the suction chuck 71, allowing the substrate 10 to be sucked and held.

[0017] The control means is configured by a computer and includes a central processing unit (CPU) that performs calculations according to a control program, a read-only memory (ROM) that stores the control program, etc., a readable and writable random access memory (RAM) that temporarily stores the detected values ​​of various sensors, calculation results, etc., an input interface, and an output interface (all of which are not shown in detail). The control means is connected to and controls each operating unit of the cutting device 1, and images captured by the imaging means 9 are stored in the control means and displayed on a display means (not shown).

[0018] The cutting device 1 shown in FIG. 1 has roughly the configuration described above, and the method for forming a mask according to this embodiment will be described below.

[0019] When carrying out the mask forming method of this embodiment, first, as shown in Figure 2(b), a mask sheet preparation process is carried out to prepare a mask sheet 20 having a size corresponding to the above-mentioned substrate 10 and a surface 20a that can be attached to the upper surface (surface 10a) of the substrate 10.

[0020] The mask sheet 20 can be selected from various sheets, and can be, for example, a UV sheet having an adhesive layer on its surface that reduces its adhesive strength when irradiated with ultraviolet light, or a thermocompression sheet that is pressed by heating, etc. In the embodiment described below, the mask sheet 20 is described as being a UV sheet having an adhesive layer on its surface that reduces its adhesive strength when irradiated with ultraviolet light.

[0021] Once the mask sheet 20 corresponding to the size of the substrate 10 has been prepared through the mask sheet preparation process, as shown in FIG. 2(b), the mask sheet 20 is placed on the holding surface of the suction chuck 71 of the chuck table 7 with the adhesive layer-formed surface 20a facing upward, and the suction source is activated to suction and hold the mask sheet 20. Next, the X-axis movement means is activated to position the chuck table 7 directly below the imaging means 9, and information on the outer shape and surface height position of the mask sheet 20 is detected and stored in the control means. Note that, since the information on the surface height position of the mask sheet 20 is the thickness of the mask sheet 20, it can also be input and stored in the control means in advance. Here, the control means pre-stores position information of the planned division lines 14 formed on the surface 10a of the substrate 10, which is the workpiece, in XY coordinates. Positions on the mask sheet 20 corresponding to the planned division lines 14 are set as planned groove formation lines for forming grooves 100, which will be described later. The groove formation lines, like the division lines 14, are set in a grid pattern with groove formation lines set in a predetermined direction and groove formation lines set in a direction perpendicular to the predetermined direction (neither of which is shown in the figure).

[0022] After the mask sheet 20 is held by suction on the chuck table 7 and information such as the outer shape of the mask sheet 20 and the height of the surface 20a is stored in the control means, the predetermined direction of the groove formation line described above is aligned with the X-axis direction, and the groove formation line to be machined is positioned directly below the cutting means 8, as shown in Figure 3(a). The cutting means 8 includes a spindle housing 80 extending in the Y-axis direction, a rotating spindle 82 rotatably supported by the spindle housing 80, a cutting blade 81A fixed to the tip of the rotating spindle 82, a blade cover 83 that covers the rotating spindle 82 and the cutting blade 81A, and a cutting water supply nozzle 84 that supplies cutting water to the area to be cut by the cutting blade 81A. The cutting blade 81A is rotated in the direction indicated by arrow R1 by a spindle motor (not shown). The cutting blade 81A is a cutting blade attached to cut the mask sheet 20 to form grooves, and for example, the thickness of the cutting edge at the tip is 100 μm, which corresponds to the width of the intended division line 14.

[0023] The cutting blade 81A, rotated at high speed, is positioned on the groove formation line aligned in the X-axis direction, and the cutting feed amount is adjusted in the Z-axis direction indicated by the arrow Z by a cutting feed means (not shown). The cutting is performed by cutting from the front surface 20a of the mask sheet 20, while the chuck table 7 is moved in the X-axis direction to form the groove 100. As can be seen from the partially enlarged cross-sectional view shown in FIG. 3(b), the groove 100 is formed with a width of 100 μm and a depth that does not reach the back surface 20b of the mask sheet 20. Furthermore, the cutting blade 81A of the cutting means 8 is indexed and fed to a groove formation line adjacent in the Y-axis direction to the groove formation line where the groove 100 is formed, but where no groove 100 is formed, and a groove 100 is formed in the same manner as above. By repeating these steps, grooves 100 are formed along all groove formation lines along the X-axis direction. Next, the chuck table 7 is rotated 90 degrees, the direction perpendicular to the direction in which the grooves 100 were previously formed is aligned with the X-axis direction, and the above-described groove formation processing is performed on all of the groove formation lines newly aligned with the X-axis direction, thereby forming grooves 100 along all of the groove formation lines on the mask sheet 20 (see FIG. 3(c)). As described above, the grooves 100 are formed along all of the groove formation lines on the mask sheet 20, thereby completing the groove formation process of this embodiment.

[0024] Once the above groove forming process is completed, the substrate 10 described based on Figure 2(a) is positioned above the mask sheet 20, and the surface 10a of the substrate 10 is faced downward as shown in the upper part of Figure 4(a), so that the surface 10a of the substrate 10 faces the surface 20a of the mask sheet 20 on which the grooves 100 have been formed by the above groove forming process, and a sheet attachment process is carried out in which the mask sheet 20 and the substrate 10 are attached by aligning the grooves 100 with the planned dividing lines 14 of the substrate 10.

[0025] The mask sheet 20 described above is, for example, a sheet in which an adhesive layer is formed by applying a UV-reactive adhesive to the upper surface of a polyolefin base material, and the adhesive strength of which quickly decreases when irradiated with ultraviolet rays.

[0026] After the sheet adhering step is completed as described above, the suction source connected to the chuck table 7 is stopped to release the negative pressure generated in the chuck table 7, and the substrate 10 with the mask sheet 20 adhered to its surface 10a is removed from the chuck table 7 as shown in FIG. 4(b). The substrate 10 removed from the chuck table 7 is transported and placed on the holding table 30 shown in FIG. 5(a) for the groove exposing step described below. A holding surface 32 configured to correspond to the shape of the substrate 10 is formed on the upper surface of the holding table 30 to hold the substrate 10. The holding surface 32 is made of a breathable material and is connected to a suction source (not shown). Activating the suction source generates negative pressure on the holding surface 32, and the substrate 10 is held by suction.

[0027] The groove exposing process is a process of thinning the back surface 20b side of the mask sheet 20 attached to the front surface 10a of the substrate 10 to expose the grooves 100 formed by the groove forming process described above on the back surface 20b side, and can be carried out, for example, by a grinding device 40 shown in Figure 5(b).

[0028] The grinding device 40 includes grinding means 42 for grinding and thinning the back surface 20b of the mask sheet 20 attached to the back surface 10b of the substrate 10 held by suction on the holding surface 32 of the holding table 30. The grinding means 42 includes a rotating spindle 43 rotated by a rotation drive mechanism (not shown), a wheel mount 44 attached to the lower end of the rotating spindle 43, and a grinding wheel 45 attached to the lower surface of the wheel mount 44, and a plurality of grinding stones 46 are arranged in an annular shape on the lower surface of the grinding wheel 45.

[0029] Once the substrate 10 is suction-held on the holding table 30, the rotating spindle 43 of the grinding means 42 is rotated in the direction indicated by arrow R2 in FIG. 5(b), e.g., at 3000 rpm, while the holding table 30 is rotated in the direction indicated by arrow R3, e.g., at 300 rpm. Then, the grinding wheel 46 is brought into contact with the back surface 20b of the mask sheet 20, and the grinding wheel 45 is fed downward, as indicated by arrow R4, at a grinding feed rate of, e.g., 1 μm / sec. This grinding operation thins the back surface 20b of the mask sheet 20 by a predetermined amount, thereby exposing grooves 100 on the back surface 20b of the mask sheet 20, as shown in FIG. 6(a). As described above, the grooves 100 are formed corresponding to the intended division lines 14 of the substrate 10. Exposing the grooves 100 on the back surface 20b of the mask sheet 20 also exposes the intended division lines 14 of the substrate 10.

[0030] The groove exposing step is not limited to the embodiment using the grinding device 40 described above. For example, another embodiment performed by a turning device 50 shown in FIG. 5(c) can also be employed. The turning device 50 includes a turning means 51 for turning and thinning the back surface 20b of the mask sheet 20 attached to the back surface 10b of the substrate 10 held by suction on the holding surface 32 of the holding table 30. The turning means 51 includes a turning wheel 53 disposed at the lower end of a rotating shaft 52 rotatably supported on a unit housing (not shown), an electric motor (not shown) disposed at the upper end of the rotating shaft 52 for rotating the turning wheel 53, and an elevating means for vertically raising and lowering the unit housing. A turning tool 54 having a cutting blade 55 made of a single crystal diamond or the like at its lower end is attached and fixed to the underside of the turning wheel 53. The turning means 51 having such a configuration is moved by the above-mentioned lifting means toward and away from the mask sheet 20 attached to the substrate 10 held by suction on the holding table 30. This allows the cutting blade 55 of the cutting tool 54 to be positioned at any desired height.

[0031] When turning the back surface 20b of the mask sheet 20 using the turning device 50, the electric motor is operated to rotate the rotary shaft 52 of the turning means 51 in the direction indicated by arrow R5 at a predetermined rotational speed (e.g., 6000 rpm) as shown in FIG. 5(c), while the lifting means is operated to lower the turning means 51 in the direction indicated by arrow R6 to a desired height position, and the holding table 30 is moved in the direction indicated by arrow R7 without rotating. The desired height position is a height position at which turning is performed to expose grooves 100 in the back surface 20b of the mask sheet 20 by turning the back surface 20b of the mask sheet 20 with the cutting tool 54, as shown in FIGS. 6(a) and 6(b). Note that when turning the back surface 20b of the mask sheet 20 using the cutting tool 54 by operating the lifting means, it is preferable to gradually lower the turning means 51 in multiple steps. Such a turning device 50 can also be used to carry out the groove exposing step of thinning the rear surface 20b of the mask sheet 20 to expose the grooves 100.

[0032] A mask covering only the region 12 is formed by the above-described mask formation method, and the substrate 10 is transported to an appropriate plating apparatus where the surface 10a of the substrate 10 is plated with a metal, such as AuSn (gold-tin) (not shown), to form a plating layer 30 of appropriate thickness on the surface 10a (see FIGS. 7(a) and 7(b)). In this embodiment, as described above, grooves 100 are formed in the mask sheet 20 along the division lines 14, and the mask sheet 20 is left over the region 12. Therefore, the plating layer 30 is formed on the mask sheet 20 in the region 12 and on the substrate 10 along the division lines 14. Note that in this embodiment, a UV sheet is used for the mask sheet 20. Therefore, before the AuSn (gold-tin) plating layer 30, which is opaque to ultraviolet light, is formed, the mask sheet 20 is irradiated with ultraviolet light to reduce the adhesive strength of the adhesive layer.

[0033] After the above-described plating process is performed on the substrate 10, as shown in FIG. 7(a), the substrate 10 is supported by an annular frame F via a protective tape T and suction-held on the chuck table 7 of the cutting device 1 described with reference to FIG. 1, and the frame F is fixed with a clamp 72 (for convenience of explanation, the clamp 72 and other elements are omitted from FIG. 7). Next, the substrate 10 is imaged by the imaging means 9 described above to detect the position of the groove 100, i.e., the planned division line 14, which is the processing position, and the substrate 10 is positioned directly below the cutting means 8. At this time, the cutting means 8 is equipped with a cutting blade 81B, which has a thinner cutting edge than the cutting blade 81A and is suitable for cutting the substrate 10 into individual chips, instead of the cutting blade 81A described above. The cutting blade 81B is thinner (e.g., 30 μm) than the cutting blade 81A and is thinner than the width of the plating layer 30 formed in the 100 μm-wide groove 100. Then, this cutting blade 81B is rotated at high speed in the direction indicated by R1, and the X-axis feed means, Y-axis feed means, and cutting feed means are operated to perform cutting feed from above along the center of the width direction of the intended division lines 14, as shown in Figure 7(b), thereby performing a dividing step in which the substrate 10 is divided into individual chips for each region 12. In this dividing step, cutting blade 81B, which has a thinner cutting edge on the tip side than the cutting blade 81A, is used to perform cutting along the intended division lines 14, and when the substrate 10 is divided into each region 12, the outer periphery of each divided chip is surrounded by plating layer 30 with a width of 35 µm.

[0034] In the above-described embodiment, after the mask forming method is performed, plating is performed without removing the mask sheet 20 on each chip, and the chips are then separated into individual chips by the cutting means 8. This prevents the chips from being contaminated by cutting debris generated by the cutting process in the separation step and cutting water containing the cutting debris. However, the present invention is not limited to this, and it is also acceptable to remove the mask 20 from the chips before performing cutting on the substrate 10.

[0035] In the above embodiment, a UV sheet was selected as the mask sheet 20 prepared in the mask sheet preparation step, but the present invention is not limited to this, and a thermocompression sheet that is pressed by heating may be selected as the mask sheet 20 prepared in the mask sheet preparation step. The thermocompression sheet used as the mask sheet 20 can be selected from, for example, polyolefin-based sheets. When the mask sheet 20 is selected from polyolefin-based sheets, it is preferable to select it from any one of a polyethylene (PE) sheet, a polypropylene (PP) sheet, and a polystyrene (PS) sheet.

[0036] When a polyethylene sheet is selected as the mask sheet 20 and the sheet adhering step described above is performed, the mask sheet 20 is heated to a predetermined temperature (120°C to 140°C, near the melting point of the polyethylene sheet) to exert adhesive force and is thermocompression-bonded to the surface 10a of the substrate 10. The heating method is not particularly limited, but the mask sheet 20 can be heated by a heater installed inside the chuck table 7 or by applying hot air from above the mask sheet 20 to raise the temperature of the mask sheet 20 to the predetermined range and exert adhesive force, thereby allowing the mask sheet 20 to be well adhered to the substrate 10 without forming an adhesive layer on the surface. When a sheet other than a polyethylene sheet is selected as the mask sheet 20, the heating temperature during thermocompression bonding can be set to a temperature near the melting point temperature of the selected sheet material, thereby allowing the mask sheet 20 to be adhered to the substrate 10 with appropriate adhesive force. To increase the degree of pressure-bonding, the mask sheet 20 may be pressed from the mask sheet 20 side using a roller or the like. When a thermocompression sheet such as that described above is selected as the mask sheet 20, it is preferable to remove it from the substrate 10 by cooling it to reduce its adhesive strength.

[0037] As in the above-described embodiment, by carrying out a mask forming method including a mask sheet preparation step, a groove forming step, a sheet attachment step, and a groove exposing step, grooves 100 are formed in the mask sheet 20 attached to the substrate 10 along the planned dividing lines 14 of the substrate 10, and masks of sizes corresponding to the individual regions 12 can be easily arranged. This eliminates the need to arrange masks of sizes corresponding to the individually divided chips corresponding to the regions 12 of the base 10 for each chip, which is troublesome and unbearable.

[0038] Furthermore, as in the prior art, when a mask sheet is attached to a substrate and then grooves are formed in the mask sheet using a cutting blade, there is a risk that the cutting blade will scratch the substrate. However, according to the present invention, grooves are formed in the mask sheet in advance, thereby avoiding scratching the substrate. [Explanation of symbols]

[0039] 1:Cutting device 2: Housing 3: Carrying in / out means 4: Cassette 4a: Cassette table 5: Temporary table 6: Means of transport 7: Chuck table 71: Vacuum chuck 72: Clamp 8: Cutting means 80: Spindle housing 81A: Cutting blade 81B: Cutting blade 82: Rotating spindle 83: Blade cover 84: Cutting water supply nozzle 9: Imaging means 10: Circuit board 12: Area 14: Planned division line 16: Cleaning equipment 17: Cleaning and carrying out means 20: Mask sheet 20a: Surface 20b: Back side 30: Plating layer 40: Grinding equipment 42: Grinding means 43: Rotating spindle 44: Wheel mount 45: Grinding wheel 46: Grinding wheel 50: Turning equipment 51: Turning means 52: Rotation axis 53: Bite wheel 54: Byte 55:Cutting blade 100: Groove

Claims

1. 1. A method for forming a mask used when metal plating is performed along planned division lines of a substrate to be divided into individual chips by the planned division lines, comprising: a mask sheet preparation step of preparing a mask sheet having a size corresponding to the substrate and a surface that can be attached to the upper surface of the substrate; a groove forming step of forming grooves on the surface of the mask sheet by positioning a cutting blade corresponding to the intended dividing lines; a sheet adhering step of making the upper surface of the substrate face the surface of the mask sheet and adhering the surface of the mask sheet to the upper surface of the substrate so that the grooves correspond to the intended division lines; a groove exposing step of thinning the back surface of the mask sheet to expose the grooves on the back surface; A method for forming a mask comprising:

2. 2. The method for forming a mask according to claim 1, wherein in the mask sheet preparation step, a UV sheet having an adhesive layer on its surface, the adhesive strength of which decreases when irradiated with ultraviolet light, is prepared as the mask sheet.

3. 2. The method for forming a mask according to claim 1, wherein in the mask sheet preparation step, a thermocompression sheet that is pressure-bonded by heating is prepared as the mask sheet.

Images