Sheet for forming protective film, method for manufacturing chip with protective film, and laminate

Abstract

A protective coating formation sheet according to one embodiment comprises a support sheet and a curable resin film disposed on one surface of the support sheet. The curable resin film is affixed to a surface of a wafer, the surface having bump electrodes, and is cured to form a protective coating on the wafer surface. The support sheet has, on the one surface thereof, a first region that has the curable resin film and a second region that surrounds the first region and does not have the curable resin film.

Description

[Technical Field]

[0001] The present invention relates to a sheet for forming a protective film, a method for producing a chip with a protective film, and a laminate. This application claims priority based on Japanese Patent Application No. 2020-031717, filed on February 27, 2020, the contents of which are incorporated herein by reference. [Background technology]

[0002] Conventionally, when mounting a multi-pin LSI package used in an MPU, gate array, or the like on a printed wiring board, a flip-chip mounting method has been adopted in which a chip with protruding electrodes (also called "bumps") made of eutectic solder, high-temperature solder, gold, or the like formed on its connection pads is used, and these protruding electrodes are brought face-down into contact with corresponding terminal portions on a chip-mounting substrate, and melted / diffusion bonded.

[0003] The chips used in this packaging method are obtained by dividing a wafer having protruding electrodes formed on its circuit surface. During this process, a curable resin film is usually applied to the circuit surface of the wafer to protect the circuit surface and protruding electrodes, and the resin film is cured to form a protective film on the circuit surface. The curable resin film is used in the form of a protective film-forming sheet, which is a laminate with a support sheet. In the protective film-forming sheet, the curable resin film is provided over the entire surface of one side of the support sheet.

[0004] For example, a curable resin film in a protective film-forming sheet is attached to the circuit surface of a wafer while being heated. The curable resin film is then cut along the periphery of the wafer together with a support sheet. The area of ​​the protective film-forming sheet that is not attached to the wafer is removed, and the support sheet is then peeled off and removed. The curable resin film is then cured to form a protective film on the circuit surface of the wafer. The wafer is then divided into individual chips, and the protective film is cut along the periphery of the chip to obtain a chip with a protective film provided on the circuit surface of the chip after cutting (see Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2017 / 077957 Summary of the Invention [Problem to be solved by the invention]

[0006] Such a curable resin film is relatively soft so that it can adhere sufficiently to the surface of the wafer having the protruding electrodes (circuit surface) when it is attached to the wafer. However, when a curable resin film that has been softened by heating is attached to the wafer, the following problems arise.

[0007] When a heated curable resin film is attached to the surface of a wafer having protruding electrodes, pressure is applied to the curable resin film. The curable resin film is usually used in the form of a protective film-forming sheet, which is a laminate with a support sheet, and this pressure is transmitted to the curable resin film through the support sheet. This pressure causes the curable resin film to flow in a direction toward the outside of the wafer's radial direction, i.e., from the area attached to the wafer to the area not attached to the wafer. In the area of ​​the curable resin film not attached to the wafer, particularly in the area near the wafer, the curable resin film flows in a direction perpendicular to the wafer's radial direction and from the curable resin film toward the wafer, resulting in a thickness greater than that of the area attached to the wafer.

[0008] In this way, the thickened areas of the curable resin film are excess parts that remain attached to the side of the wafer or to some part of the manufacturing equipment for the protective film-coated chips during any of the manufacturing processes for the protective film-coated chips, thereby contaminating these.

[0009] The present invention aims to provide a sheet for forming a protective film, which comprises a resin film that is attached to a surface of a wafer having protruding electrodes and cured to form a protective film on the surface, and which, when attached to a surface of a wafer having protruding electrodes, can suppress the formation of areas where the resin film becomes thick due to flow of the resin film. [Means for solving the problem]

[0010] The present invention employs the following configuration. [1] A sheet for forming a protective film comprising a support sheet and a curable resin film provided on one side of the support sheet, wherein the curable resin film is a resin film that is attached to a surface of a wafer having protruding electrodes and cured to form a protective film on the surface of the wafer, and the support sheet has, on its one side, a first region in which the curable resin film is provided, and a second region surrounding the first region and in which the curable resin film is not provided.

[0011] [2] A strain is generated in a test piece of the curable resin film having a diameter of 25 mm and a thickness of 1 mm under the conditions of a temperature of 90°C and a frequency of 1 Hz, and the storage modulus of the test piece is measured. When the storage modulus of the test piece when the strain of the test piece is 1% is defined as Gc1, and the storage modulus of the test piece when the strain of the test piece is 300% is defined as Gc300, the following formula is obtained: X=Gc1 / Gc300 The sheet for forming a protective film according to [1], wherein the X value calculated by the above formula is 19 or more and less than 10,000. [3] The sheet for forming a protective film according to [1] or [2], wherein the thickness of the curable resin film is 25 μm or more. [4] The sheet for forming a protective film according to any one of [1] to [3], wherein the maximum width of the curable resin film is 140 to 150 mm, 190 to 200 mm, 290 to 300 mm, or 440 to 450 mm.

[0012] [5] The sheet for forming a protective film according to any one of [1] to [4], wherein the support sheet is circular. [6]. A sheet for forming a protective film according to [5], wherein the support sheet is an adhesive sheet or has a jig adhesive layer along the outer periphery of the support sheet. [7] The sheet for forming a protective film according to any one of [1] to [4], wherein the support sheet is a release film. [8] The sheet for forming a protective film according to any one of [1] to [7], wherein grooves that become the dividing points of the wafer are formed on the surface of the wafer.

[0013] [9]. A method for manufacturing a chip with a protective film, comprising: a bonding step of bonding the curable resin film in the sheet for forming a protective film described in any one of [1] to [8] to a surface of a wafer having protruding electrodes while heating it; a curing step of forming a protective film on the surface of the wafer by curing the curable resin film after bonding; and a processing step of dividing the wafer after forming the protective film and cutting the protective film to obtain a chip with a protective film comprising a chip and the protective film provided on the chip after cutting.

[10] The wafer has an area in a plan view of the surface equal to or greater than the area of ​​the surface of the curable resin film attached to the wafer, The method for manufacturing a chip with a protective film according to [9], wherein in the attaching step, the entire attachment surface of the curable resin film is attached to the surface of the wafer.

[0014]

[11] . A method for manufacturing a chip with a protective film described in [9] or

[10] , wherein a groove is formed on the surface of the wafer at which the wafer is divided, and in the bonding process, the curable resin film is filled into the groove when it is bonded to the surface of the wafer.

[12] The method for producing a chip with a protective film according to any one of [9] to

[11] , wherein in the attaching step, the curable resin film is attached to the surface of the wafer using a roller.

[13] A laminate obtained by forming a thermosetting resin film on the release-treated surface of a release film, processing the thermosetting resin film together with the release film into a circular shape, and bonding the entire surface opposite the side with the release film to the surface of a strip-shaped backgrind tape.

[14] A laminate comprising a release film, a thermosetting resin film provided on one release-treated surface of the release film, and a backgrind tape provided on the surface of the thermosetting resin film opposite the release film side, wherein the planar shapes of the release film and the thermosetting resin film are both circular, the release film and the thermosetting resin film are arranged so that their outer peripheries coincide with each other in the radial direction, and the backgrind tape is strip-shaped. [Effects of the Invention]

[0015] 1 is a cross-sectional view for schematically explaining the problem to be solved by the present invention. Among the regions of the curable resin film 62 that are not attached to the wafer 9, a region 622 near the peripheral edge typically has a lower temperature than a region 621 of the curable resin film 62 that is attached to the wafer 9 and a region 620 near the wafer 9 that is not attached to the wafer 9. This is because, for example, as described below, the region 621 of the curable resin film 62 that is attached to the wafer 9 is typically heated using the heated wafer 9 as a heat source. Heat easily propagates to the regions 621 and 620, causing the temperature to rise, whereas heat does not easily propagate to the region 622 near the peripheral edge, which is far from the wafer 9. As a result, the curable resin film 62 is more likely to flow in a region 621 attached to the wafer 9 and in a region 620 in the vicinity of the wafer 9 where the curable resin film 62 is not attached to the wafer 9, whereas the region 622 in the vicinity of the peripheral portion where the temperature of the curable resin film 62 is lower has lower fluidity, which blocks the flowing curable resin film 62. Therefore, as explained above, the region of the curable resin film 62 not attached to the wafer 9, particularly the region 620 in the vicinity of the wafer 9, has a greater thickness than the region 621 attached to the wafer 9, which becomes more pronounced.

[0016] In contrast, by using the sheet for forming a protective film of the present invention, when the curable resin film in the sheet for forming a protective film is attached to the surface of a wafer having protruding electrodes, the area of ​​the curable resin film that is not attached to the wafer can be narrowed or eliminated, and the amount of flowing curable resin film can be reduced, thereby suppressing the formation of an area where the curable resin film is thick. Furthermore, since there is no area where the temperature is low in the area near the peripheral portion of the curable resin film, the formation of an area where the curable resin film is thick can be more effectively suppressed.

[0017] According to the method for manufacturing a chip with a protective film of the present invention, by manufacturing a chip with a protective film using such a protective film forming sheet, it is possible to prevent the side of the wafer or any part of the manufacturing equipment for the chip with a protective film from being contaminated by the adhesion of excess parts of the curable resin film. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 1 is a cross-sectional view for schematically explaining a problem to be solved by the present invention. [Figure 2] 1 is a plan view schematically illustrating an example of a sheet for forming a protective film according to an embodiment of the present invention. [Figure 3] 3 is a cross-sectional view of the sheet for forming a protective film taken along line II shown in FIG. 2. FIG. [Figure 4] FIG. 2 is a plan view schematically illustrating another example of the sheet for forming a protective film according to one embodiment of the present invention. [Figure 5] FIG. 10 is a plan view schematically illustrating still another example of the sheet for forming a protective film according to one embodiment of the present invention. [Figure 6A] 1A to 1C are cross-sectional views for schematically explaining an example of a method for manufacturing a chip with a protective film according to an embodiment of the present invention. [Figure 6B] 1A to 1C are cross-sectional views for schematically explaining an example of a method for manufacturing a chip with a protective film according to an embodiment of the present invention. [Figure 6C]1A to 1C are cross-sectional views for schematically explaining an example of a method for manufacturing a chip with a protective film according to an embodiment of the present invention. [Figure 6D] 1A to 1C are cross-sectional views for schematically explaining an example of a method for manufacturing a chip with a protective film according to an embodiment of the present invention. [Figure 6E] 1A to 1C are cross-sectional views for schematically explaining an example of a method for manufacturing a chip with a protective film according to an embodiment of the present invention. [Figure 7A] 10A to 10C are cross-sectional views for schematically explaining another example of the method for manufacturing a chip with a protective film according to one embodiment of the present invention. [Figure 7B] 10A to 10C are cross-sectional views for schematically explaining another example of the method for manufacturing a chip with a protective film according to one embodiment of the present invention. [Figure 7C] 10A to 10C are cross-sectional views for schematically explaining another example of the method for manufacturing a chip with a protective film according to one embodiment of the present invention. [Figure 7D] 10A to 10C are cross-sectional views for schematically explaining another example of the method for manufacturing a chip with a protective film according to one embodiment of the present invention. [Figure 7E] 10A to 10C are cross-sectional views for schematically explaining another example of the method for manufacturing a chip with a protective film according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0019] <<Protective film forming sheet>> A protective film forming sheet according to one embodiment of the present invention comprises a support sheet and a curable resin film provided on one side of the support sheet, wherein the curable resin film is a resin film that is attached to a surface of a wafer having protruding electrodes and cured to form a protective film on the surface of the wafer, and the support sheet has, on its one side, a first region in which the curable resin film is provided, and a second region surrounding the first region and in which the curable resin film is not provided. Since the protective film forming sheet of this embodiment has the first region and the second region in the support sheet, when the curable resin film in the protective film forming sheet is attached to the surface of the wafer having the protruding electrodes, the formation of an area of ​​the curable resin film that is not attached to the wafer and is thick can be suppressed. Hereinafter, the sheet for forming a protective film of this embodiment will be described with reference to the drawings.

[0020] FIG. 2 is a plan view schematically showing an example of the sheet for forming a protective film of this embodiment, and FIG. 3 is a cross-sectional view taken along line II of the sheet for forming a protective film shown in FIG. The drawings used in the following explanation may show key parts enlarged for convenience in order to make the features of the present invention easier to understand, and the dimensional ratios of each component may not necessarily be the same as in reality. In FIG. 3 and subsequent figures, the same components as those shown in the figures already described are given the same reference numerals as in the figures already described, and detailed description thereof will be omitted.

[0021] The protective film-forming sheet 1 shown here includes a support sheet 11 and a curable resin film 12 provided on one surface 11 a of the support sheet 11 . The support sheet 11 has, on one surface 11a thereof, i.e., the surface on the curable resin film 12 side, a first region 111a where the curable resin film 12 is provided, and a second region 112a that surrounds the first region 111a and where the curable resin film 12 is not provided. That is, in the support sheet 11, the entire first region 111a is covered with the curable resin film 12, and the entire second region 112a is not covered with the curable resin film 12.

[0022] The second region 112a on one surface 11a of the support sheet 11 is preferably exposed (is an exposed surface).

[0023] The curable resin film 12 is a resin film that is attached to the surface of the wafer having the protruding electrodes and cured to form a protective film on the surface of the wafer having the protruding electrodes. In this specification, the term "wafer" refers to a semiconductor wafer made of an elemental semiconductor such as silicon, germanium, or selenium, or a compound semiconductor such as GaAs, GaP, InP, CdTe, ZnSe, or SiC; or an insulating wafer made of an insulating material such as sapphire or glass.

[0024] A circuit is formed on one surface of each of these wafers, and in this specification, the surface of the wafer on which the circuit is formed is referred to as the "circuit side." The surface of the wafer opposite the circuit side is referred to as the "back side." The surface of the wafer having the protruding electrodes and the circuit side are synonymous. The wafer is divided into chips by dicing or other means. In this specification, as with the wafer, the surface of the chip on which the circuit is formed is referred to as the "circuit side," and the surface of the chip opposite the circuit side is referred to as the "back side." Both the circuit surface of the wafer and the circuit surface of the chip are provided with protruding electrodes such as bumps, pillars, etc. The protruding electrodes are preferably made of solder.

[0025] The support sheet 11 supports the curable resin film 12. More specifically, examples of the support sheet 11 include a sheet consisting of only a substrate having such a supporting function; a release film; and an adhesive sheet that can be attached to a wafer when grinding the backside of the wafer. The adhesive sheet may be attached to a jig such as a ring frame at its peripheral portion. Furthermore, if the support sheet 11 is the release film, it may be easier to manufacture the sheet for forming a protective film, as described below.

[0026] The planar shape of support sheet 11, i.e., the shape of one surface 11a, is circular. For example, when support sheet 11 is an adhesive sheet or, as will be described later, when support sheet 11 has a jig adhesive layer along its outer periphery, it is particularly preferable that support sheet 11 has a circular planar shape. The reason for this is that such a planar shape of support sheet 11 fits the inner periphery of a jig such as a ring frame, which is usually circular, and there is no need to cut support sheet 11 after it is attached to a jig such as a ring frame.

[0027] The planar shape of the curable resin film 12, i.e., the shape of the surface 12a opposite to the support sheet 11, is circular. Note that the wafer may have an orientation flat or a notch for identifying the crystal orientation or for alignment, and the shape of the wafer may not be a perfect circle, but the curable resin film 12 can also have a planar shape that matches this.

[0028] When the protective film forming sheet 1 is viewed in a plan view from above the curable resin film 12 side, the support sheet 11 and the curable resin film 12 are arranged concentrically with their centers aligned. The maximum width of the support sheet 11, i.e., the diameter D 11 is the maximum width of the curable resin film 12, i.e., the diameter D 12 is greater than.

[0029] The planar shape and size of the first region 111a of the support sheet 11 are the same as those of the curable resin film 12, and the diameter D 12 It is a circle. The planar shape of the second region 112a of the support sheet 11 is 11 -D 12 ) / 2 is a ring.

[0030] The area of ​​the surface 12a of the curable resin film 12 opposite to the support sheet 11 side (the area of ​​the first region 111a of the support sheet 11) is preferably equal to or less than the area of ​​the back surface of the wafer to which the curable resin film 12 is to be attached (the area in a plan view of the surface of the wafer having the protruding electrodes). By selecting such a curable resin film 12, when the curable resin film 12 in the protective film-forming sheet 1 is attached to the surface of the wafer having the protruding electrodes, the amount of the curable resin film 12 that protrudes onto the second region 112a of the support sheet 11 can be further reduced, and as a result, the formation of an area of ​​the curable resin film 12 that is not attached to the wafer and has a large thickness can be further suppressed.

[0031] Maximum width (diameter) D of the curable resin film 12 12 is preferably equal to or smaller than the maximum diameter (for example, diameter) of the wafer to which the curable resin film 12 is to be attached. Wafers having a circular planar shape include those having diameters of, for example, 6 inches, 8 inches, 12 inches, and 18 inches. A preferred curable resin film 12 to be attached to any of these wafers has a maximum width (diameter) D 12 However, examples of the thickness are 140 to 150 mm, 190 to 200 mm, 290 to 300 mm, or 440 to 450 mm.

[0032] On the one surface 11a of the support sheet 11, the width ((D 11 -D 12 ) / 2) is the maximum value of the width of the first region 111a (D 12 ), it is preferably 0.05 to 0.4 times, and more preferably 0.07 to 0.3 times. When the width of the second region 112a is equal to or greater than the lower limit, if the support sheet 11 is an adhesive sheet or has the jig adhesive layer, the possibility of the curable resin film 12 coming into contact with the jig when the support sheet 11 is attached to the jig such as a ring frame can be reduced. When the width of the second region 112a is equal to or less than the upper limit, it is possible to prevent the area of ​​the second region 112a from becoming excessively large.

[0033] Grooves that will serve as dividing points for dividing the wafer into individual chips may be formed on the surface of the wafer that has the protruding electrodes and is to be attached to the curable resin film 12. That is, the curable resin film 12 may be attached to the surface of the wafer that has the protruding electrodes and also has the grooves that will serve as dividing points for the wafer, and may be cured to form a protective film on the surface of the wafer. The grooves are formed on the surface of the wafer having the protruding electrodes in a pattern corresponding to the size and shape of the desired chip.

[0034] For example, by grinding the surface (back surface) opposite to the surface having the protruding electrodes, the grooves are formed until the grooves appear, resulting in chips separated at the grooves. At this time, the grooves are filled with the curable resin film 12 by applying the curable resin film 12. As a result, the cured product of the curable resin film 12, i.e., the protective film, is filled. After the chips are obtained, the protective film between the chips is cut to obtain chips with protective film, which are provided not only on the surface having the protruding electrodes but also on all four side surfaces. Chips whose side surfaces are also protected in this way can be provided with a higher level of protection from the protective film.

[0035] The support sheet 11 and the curable resin film 12 may each be made up of one layer (single layer) or two or more layers. When the support sheet 11 or the curable resin film 12 is made up of multiple layers, these multiple layers may be the same or different from each other, and the combination of these multiple layers is not particularly limited.

[0036] In this specification, not only in the case of the support sheet 11 and the curable resin film 12, "multiple layers may be the same or different from each other" means "all layers may be the same, all layers may be different, or only some layers may be the same", and further, "multiple layers are different from each other" means "at least one of the constituent materials and thicknesses of each layer is different from each other".

[0037] Thickness T of the curable resin film 12 12 is not particularly limited, but is preferably 10 μm or more, more preferably 20 μm or more, and even more preferably 25 μm or more. 12 When the curable resin film 12 is applied to a surface of a wafer having protruding electrodes and having the grooves formed thereon, the curable resin film 12 can fill the grooves more thoroughly and without gaps. Furthermore, the bases of the protruding electrodes of the wafer near the circuit surface can be covered more thoroughly and without gaps. In other words, the curable resin film 12 is advantageous in terms of filling the grooves and covering the bases of the protruding electrodes.

[0038] Thickness T of the curable resin film 12 12 For example, in order to prevent the thickness of the curable resin film 12 from becoming excessive, the upper limit of T 12 is preferably 200 μm or less, more preferably 130 μm or less, and even more preferably 80 μm or less.

[0039] In this specification, the "thickness of a curable resin film" means the thickness of the entire curable resin film. For example, the thickness of a curable resin film consisting of multiple layers means the total thickness of all layers constituting the curable resin film.

[0040] In the protective film-forming sheet 1, strain was generated in a test piece of the curable resin film 12 having a diameter of 25 mm and a thickness of 1 mm under conditions of a temperature of 90°C and a frequency of 1 Hz, and the storage elastic modulus of the test piece was measured. When the storage elastic modulus of the test piece when the strain of the test piece is 1% is defined as Gc1 and the storage elastic modulus of the test piece when the strain of the test piece is 300% is defined as Gc300, the following formula is obtained: X=Gc1 / Gc300 It is preferable that the X value calculated by the above formula is equal to or greater than 19 and less than 10000. Such a curable resin film 12 is soft and suitable for application to an object having an uneven surface, such as a wafer surface having protruding electrodes and a wafer having the grooves.

[0041] The test piece is in the form of a film, and its planar shape is circular. The test piece may be a single-layer curable resin film 12 having a thickness of 1 mm, but in terms of ease of preparation, it is preferable that the test piece be a laminated film composed of multiple single-layer curable resin films 12 having a thickness of less than 1 mm. The thicknesses of the multiple single-layer curable resin films 12 that make up the laminated film may all be the same, all different, or only some of them may be the same, but it is preferable that they are all the same in terms of ease of production.

[0042] In this specification, the term "storage modulus of a test piece" is not limited to Gc1 and Gc300 and means "the storage modulus of a test piece corresponding to a strain generated in a test piece of a curable resin film having a diameter of 25 mm and a thickness of 1 mm under conditions of a temperature of 90°C and a frequency of 1 Hz."

[0043] When the curable resin film 12 is applied to the wafer surface having the protruding electrodes, the tops of the protruding electrodes protrude through the curable resin film 12. The curable resin film 12 then spreads between the protruding electrodes to cover them, adhering closely to the wafer surface having the protruding electrodes and covering the surfaces of the protruding electrodes, particularly the surfaces of the wafer surfaces near the protruding electrodes, embedding the bases of the protruding electrodes. In this state, the curable resin film 12 is prevented from remaining on the tops and other upper portions of the protruding electrodes. Therefore, the protective film 12', which is the cured product of the curable resin film 12, is also naturally prevented from adhering to the tops of the protruding electrodes. Furthermore, if the grooves are formed on the surface, the degree of distortion of the curable resin film 12 differs significantly between the middle stage when the curable resin film 12 begins to penetrate the grooves and the final stage when the curable resin film 12 covers the bases of the protruding electrodes and fully fills the grooves. More specifically, the strain of the curable resin film 12 is large in the middle stage, and the strain of the curable resin film 12 is small in the final stage. The curable resin film 12 employs Gc1 as the storage modulus when the strain is small and Gc300 as the storage modulus when the strain is large, and by setting Gc1 high and Gc300 low, and specifying the X value (=Gc1 / Gc300) to be 19 or more and less than 10,000, the excellent effects described above are achieved.

[0044] In order to enhance the effect of the curable resin film 12 covering the base of the protruding electrode, the X value is preferably 5000 or less, more preferably 2000 or less, even more preferably 1000 or less, and particularly preferably 500 or less, and may be, for example, any one of 300 or less, 100 or less, and 70 or less. In order to enhance the effect of suppressing the remaining of the curable resin film 12 on the upper part of the protruding electrode and the effect of the curable resin film 12 sufficiently filling the groove, the X value is preferably 25 or more, more preferably 30 or more, even more preferably 40 or more, particularly preferably 50 or more, and may be, for example, 60 or more.

[0045] In the curable resin film 12, Gc1 is not particularly limited as long as the X value is 19 or more and less than 10,000. However, in terms of ease of increasing the X value, Gc1 is 1×10 4 ~1×10 6 Pa is preferred, and 3×10 4 ~7×10 5 Pa is more preferable, and 5×10 4 ~5×10 5 Pa is more preferred.

[0046] In the curable resin film 12, Gc300 is not particularly limited as long as the X value is 19 or more and less than 10,000. However, in order to enhance the effect of the curable resin film 12 in sufficiently filling the grooves, Gc300 is preferably less than 15,000 Pa, more preferably 10,000 Pa or less, even more preferably 5,000 Pa or less, and particularly preferably 4,000 Pa or less, and may be, for example, 3,500 Pa or less. In order to enhance the effect of the curable resin film 12 covering the bases of the protruding electrodes, Gc300 is preferably 100 Pa or more, more preferably 500 Pa or more, and even more preferably 1000 Pa or more.

[0047] In the curable resin film 12, it is preferable that both Gc1 and Gc300 satisfy any one of the above-mentioned numerical ranges.

[0048] The storage modulus of the curable resin film 12 can be adjusted not only by Gc1 and Gc300 but also by adjusting the components contained in the curable resin film 12 and their contents. More specifically, for example, by using polyvinyl acetal as the polymer component (A) or the polymer (b) not having an energy ray-curable group (described later), Gc300 can be adjusted to an appropriate value, and the X value can be easily adjusted to an appropriate value. Furthermore, by adjusting the type or content of the additive (I) (described later), Gc1 can be adjusted to an appropriate value, and the X value can be easily adjusted to an appropriate value. Furthermore, by increasing the content of either or both of the filler (D) and the additive (I) (described later), Gc1 can be easily adjusted to a large value, and as a result, the X value can be easily adjusted to a large value. The components contained in the curable resin film 12 will be described separately.

[0049] The thickness of the support sheet 11 is not particularly limited, but is preferably 50 to 850 μm, and more preferably 75 to 700 μm. When the thickness of the support sheet 11 is equal to or greater than the lower limit, the strength of the support sheet 11 increases. When the thickness of the support sheet 11 is equal to or less than the upper limit, the flexibility of the support sheet 11 increases, and the handleability of the support sheet 11 improves.

[0050] In this specification, the "thickness of the support sheet" means the thickness of the entire support sheet; for example, the thickness of a support sheet consisting of multiple layers means the total thickness of all layers that make up the support sheet.

[0051] FIG. 4 is a plan view schematically showing another example of the sheet for forming a protective film of the present embodiment. The protective film-forming sheet 2 shown here includes a support sheet 21 and a curable resin film 12 provided on one surface 21 a of the support sheet 21 .

[0052] The support sheet 21 is long and strip-shaped, and a plurality of curable resin films 12 are arranged in a row in the longitudinal direction. The support sheet 21 is the same as the support sheet 11 in the sheet for forming a protective film 1 shown in Figures 2 and 3, except for the difference in shape and size in plan view. For example, the thickness of the support sheet 21 is the same as the thickness of the support sheet 11. The sheet 2 for forming a protective film is the same as the sheet 1 for forming a protective film shown in Figures 2 and 3, except that it has a support sheet 21 instead of the support sheet 11 and the number of curable resin films 12 is different.

[0053] The protective film forming sheet 2 is suitable for continuously attaching the curable resin film 12 to the surfaces of a plurality of wafers having projecting electrodes.

[0054] The support sheet 21 has, on one surface 21a thereof, i.e., the surface on the curable resin film 12 side, a plurality of first regions 211a where the curable resin film 12 is provided, and second regions 212a surrounding these first regions 211a and where the curable resin film 12 is not provided. That is, in the support sheet 21, the entire area of ​​each of the first regions 211a is covered with the curable resin film 12, and the entire area of ​​the second regions 112a is not covered with the curable resin film 12. The second region 212a on one surface 21a of the support sheet 21 is preferably exposed (is an exposed surface).

[0055] The planar shape of the support sheet 21, that is, the shape of the one surface 21a, is rectangular, and preferably strip-shaped. When the sheet for protective film formation 2 is viewed from above on the side of the curable resin films 12 in a plan view, all the curable resin films 12 are provided on the support sheet 21 at equal intervals from one another. All of the curable resin films 12 in the protective film-forming sheet 2 have the same shape and size. In the width direction (direction perpendicular to the longitudinal direction) of the protective film-forming sheet 2, all of the curable resin films 12 are arranged at the same position, which coincides with the middle position of the protective film-forming sheet 2 in the width direction. Maximum width D of the support sheet 21 21 is the maximum width of the curable resin film 12, i.e., the diameter D 12 Here, since the width of the support sheet 21 is constant in the longitudinal direction of the support sheet 21, the maximum value of the width of the support sheet 21 simply means the width of the support sheet 21.

[0056] The planar shape and size of the first region 211a of the support sheet 21 are the same as those of the curable resin film 12, and the diameter D 12 It is a circle. The planar shape of the second region 212a of the support sheet 21 varies from a rectangle to a plurality of diameters D 12 The shape is created by removing a row of circles.

[0057] On the one surface 21a of the support sheet 21, when the minimum value of the line segment connecting one point on the outer periphery of the first region 211a and one point on the outer periphery of the support sheet 21 is L1 and the distance between two adjacent curable resin films 12 is L2, the smaller value of L1 and L2 / 2 is the maximum value of the width of the first region 211a (D 12 ), it is preferably 0.03 to 0.25 times, and more preferably 0.05 to 0.2 times. The value may be adjusted appropriately, for example, in accordance with the specifications of an apparatus for continuously attaching the curable resin film 12 to the surfaces of a plurality of wafers having protruding electrodes. Here, L1 is set to (D 21 -D 12 ) / 2, the formula expressing L1 differs depending on the position of the first region 211a on the one surface 21a of the support sheet 21 and the size of the first region 211a.

[0058] The sheet for forming a protective film of this embodiment is not limited to those shown in FIGS. 2 to 4, and may have some components changed, deleted, or added to those shown in FIGS. For example, in the sheet 1 for forming a protective film shown in Fig. 2, as shown in Fig. 5, a band-shaped (here, annular) jig adhesive layer 13 may be provided in the second region 112a of the one surface 11a of the support sheet 11 along the outer periphery of the support sheet 11. The jig adhesive layer 13 is a layer for fixing the sheet 1 for forming a protective film to a jig such as a ring frame. Similarly, in the protective film forming sheet 2 shown in Figure 4, a ring-shaped jig adhesive layer may be provided in the second region 212a of the one surface 21a of the support sheet 21 for each curable resin film 12, surrounding the first region 211a without contacting the curable resin film 12.

[0059] For example, in the protective film forming sheet 1 shown in Figure 2, when the support sheet 11 is an adhesive sheet, a jig adhesive layer (for example, jig adhesive layer 13 shown in Figure 5) may be further provided on the adhesive layer of the adhesive sheet.

[0060] For example, in the protective film forming sheet 1 shown in Figure 2 and the protective film forming sheet 2 shown in Figure 4, the planar shape of the curable resin film 12 is circular, but the planar shape of the curable resin film is not limited to this and may be non-circular, such as rectangular.

[0061] 4, some or all of the curable resin films 12 do not have to be arranged at equal intervals from one another, and some or all of the curable resin films 12 do not have to have the same shape or size. Furthermore, some or all of the curable resin films 12 do not have to be arranged at the same position in the width direction of the sheet 2 for forming a protective film.

[0062] For example, in the sheet for forming a protective film 2 shown in FIG. 4, the number of the curable resin films 12 is three or more, but the number of the curable resin films 12 is not limited to this.

[0063] For example, in the protective film formation sheet 1 shown in FIG. 2 or the protective film formation sheet 2 shown in FIG. 4, a support sheet may be provided on both sides of the curable resin film 12 (the surface on the support sheet 11 side or the support sheet 21 side, and the surface 12a opposite thereto). As an example, in the protective film formation sheet 2 shown in FIG. 4, the support sheet 11 shown in FIG. 2 may be provided on the surface 12a of the curable resin film 12 opposite the surface on the support sheet 21 side. In this case, it is preferable that the support sheet 21 is a release film and that the support sheet 11 is a pressure-sensitive adhesive sheet or a support sheet having the jig adhesive layer (for example, the jig adhesive layer 13 shown in FIG. 5). Use of a protective film formation sheet having such a configuration facilitates continuous supply of the protective film formation sheet 1 shown in FIG. 2. In a protective film formation sheet having such a configuration, both the support sheet 11 and the support sheet 21 have a second region in which the curable resin film 12 is not provided. However, the support sheet 11 usually functions as a support sheet having the effects of the present invention.

[0064] An example of a sheet for forming a protective film of this embodiment is a laminate obtained by forming a thermosetting resin film on the release-treated surface of a release film, processing the thermosetting resin film together with the release film into a circular shape, and bonding the entire surface opposite the side with the release film to the surface of a strip-shaped backgrind tape. The laminate is included in the laminate structure of the support sheet 21 and the curable resin film 12 in the protective film-forming sheet 2 shown in Fig. 4. In this laminate, the backgrind tape corresponding to the support sheet 21 has the second region, but the release film does not have the second region.

[0065] An example of a protective film forming sheet of this embodiment is a laminate comprising a release film, a thermosetting resin film provided on one release-treated surface of the release film, and a backgrind tape provided on the surface of the thermosetting resin film opposite the release film side, wherein the planar shapes of the release film and the thermosetting resin film are both circular, the release film and the thermosetting resin film are arranged so that their outer peripheries coincide with each other in the radial direction, and the backgrind tape is strip-shaped. In this laminate, the backgrind tape corresponding to the support sheet has a second region, but the release film does not have a second region.

[0066] An example of a protective film forming sheet of this embodiment is a protective film forming sheet comprising a support sheet and a curable resin film provided on one side of the support sheet, wherein the curable resin film is a resin film that is attached to a surface of a wafer having protruding electrodes and cured to form a protective film on the surface of the wafer, and the support sheet has, on its one side, a first region where the curable resin film is provided, and a second region that surrounds the first region and where the curable resin film is not provided (however, this does not include a laminate obtained by forming a thermosetting resin film on the release-treated surface of a release film, processing the thermosetting resin film together with the release film into a circular shape, and bonding the entire surface opposite the side with the release film to the surface of a strip-shaped backgrind tape).

[0067] Another example of the protective film forming sheet of this embodiment is a protective film forming sheet comprising a support sheet and a curable resin film provided on one side of the support sheet, wherein the curable resin film is a resin film that is attached to a surface of a wafer having protruding electrodes and cured to form a protective film on the surface of the wafer, and the support sheet has, on its one side, a first region where the curable resin film is provided and a second region that surrounds the first region and where the curable resin film is not provided (however, this excludes laminates that comprise a release film, a thermosetting resin film provided on one release-treated surface of the release film, and a backgrind tape provided on the surface of the thermosetting resin film opposite to the release film side, wherein the planar shapes of the release film and the thermosetting resin film are both circular, the release film and the thermosetting resin film are arranged so that the positions of their outer peripheries coincide with each other in the radial direction, and the backgrind tape is strip-shaped).

[0068] The curable resin film constituting the sheet for forming a protective film of the present embodiment may be either thermosetting or energy ray curable, or may have both thermosetting and energy ray curable properties.

[0069] As used herein, "energy rays" refers to electromagnetic waves or charged particle beams that have an energy quantum. Examples of energy rays include ultraviolet rays, radioactive rays, and electron beams. Ultraviolet rays can be irradiated using, for example, a high-pressure mercury lamp, a fusion lamp, a xenon lamp, a black light, or an LED lamp as an ultraviolet light source. Electron beams can be irradiated using those generated by an electron beam accelerator or the like. In this specification, the term "energy ray curable" means the property of being cured by irradiation with energy rays.

[0070] The curable resin film can be formed using a curable resin film-forming composition containing its constituent materials. For example, the curable resin film can be formed by applying the curable resin film-forming composition to the surface to be formed and drying it as necessary. The ratio of the contents of the components that do not vaporize at room temperature in the curable resin film-forming composition is usually the same as the ratio of the contents of the components in the curable resin film. In this specification, "room temperature" means a temperature that is not particularly cooled or heated, i.e., an ordinary temperature, and examples thereof include a temperature of 15 to 25°C.

[0071] The coating of the curable resin film-forming composition may be carried out by a known method, for example, a method using various coaters such as an air knife coater, a blade coater, a bar coater, a gravure coater, a roll coater, a roll knife coater, a curtain coater, a die coater, a knife coater, a screen coater, a Mayer bar coater, or a kiss coater.

[0072] Regardless of whether the curable resin film is thermosetting or energy ray-curable, the drying conditions for the curable resin film-forming composition are not particularly limited. However, when the curable resin film-forming composition contains a solvent, which will be described later, it is preferable to heat-dry it. The solvent-containing curable resin film-forming composition is preferably heat-dried, for example, at 70 to 130°C for 10 seconds to 5 minutes. However, it is preferable to heat-dry the thermosetting resin film-forming composition so as not to thermally cure the composition itself or the thermosetting resin film formed from this composition.

[0073] The thermosetting resin film may, for example, contain a polymer component (A) and a thermosetting component (B). Examples of the composition for forming a thermosetting resin film include a composition for forming a thermosetting resin film (III) (sometimes simply referred to as "composition (III)" in this specification) containing a polymer component (A) and a thermosetting component (B).

[0074] The polymer component (A) is preferably polyvinyl acetal, from the viewpoint of facilitating the adjustment of the above-mentioned Gc300 to an appropriate value and the X value to an appropriate value. The polyvinyl acetal in the polymer component (A) may be any known polyvinyl acetal, and among these, preferred examples include polyvinyl formal and polyvinyl butyral, with polyvinyl butyral being more preferred.

[0075] Examples of the thermosetting component (B) include epoxy-based thermosetting resins composed of an epoxy resin (B1) and a thermosetting agent (B2); polyimide resins; and unsaturated polyester resins.

[0076] The thermosetting resin film and the composition (III) may further contain other components that do not fall into either the polymer component (A) or the thermosetting component (B). Examples of the other components include a curing accelerator (C), a filler (D), a coupling agent (E), a crosslinking agent (F), an energy ray-curable resin (G), a photopolymerization initiator (H), an additive (I), and a solvent.

[0077] By adjusting the content of the filler (D), the X value can be more easily adjusted. The filler (D) may be either an organic filler or an inorganic filler, but is preferably an inorganic filler. Preferred inorganic fillers include, for example, powders of silica, alumina, talc, calcium carbonate, titanium white, red iron oxide, silicon carbide, boron nitride, etc.; beads obtained by spheronizing these inorganic fillers; surface-modified products of these inorganic fillers; single-crystal fibers of these inorganic fillers; and glass fibers. Among these, the inorganic filler is preferably silica or alumina.

[0078] From the viewpoint of further improving the filling property of the thermosetting resin film into the grooves of the wafer, the content of the filler (D) relative to the total content of all components other than the solvent in the thermosetting resin film and the composition (III) is preferably 5 to 45 mass%, more preferably 5 to 40 mass%, and even more preferably 5 to 30 mass%.

[0079] Examples of the additive (I) include colorants, plasticizers, antistatic agents, antioxidants, gettering agents, rheology control agents, surfactants, and silicone oils. Examples of the additive (I) that are preferable in terms of being able to appropriately adjust the above-mentioned Gc1 and easily adjust the X value include rheology control agents, surfactants, silicone oils, and the like.

[0080] More specifically, examples of the rheology control agent include polyhydroxycarboxylic acid esters, polycarboxylic acids, and polyamide resins. Examples of the surfactant include modified siloxane and acrylic polymer. Examples of the silicone oil include aralkyl-modified silicone oil and modified polydimethylsiloxane, and examples of the modifying group include aralkyl groups; polar groups such as hydroxy groups; and groups having an unsaturated bond such as vinyl groups and phenyl groups.

[0081] From the viewpoint of making it easier to adjust the X value, the ratio of the content of additive (I) to the total content of all components other than the solvent in the thermosetting resin film and the composition (III) is preferably 0.5 to 10 mass%, more preferably 0.5 to 7 mass%, and even more preferably 0.5 to 5 mass%.

[0082] The thermosetting resin film and the composition (III) contain the polymer component (A), the thermosetting component (B), the curing accelerator (C), the filler (D), the coupling agent (E), the crosslinking agent (F), the energy ray curable resin (G), the photopolymerization initiator (H), the additive (I), the solvent, and the like. Each of these components may be one type or two or more types, and when two or more types are used, the combination and ratio thereof can be selected arbitrarily.

[0083] The energy ray-curable resin film may, for example, be one containing an energy ray-curable component (a). Examples of the composition for forming an energy ray-curable resin film include a composition for forming an energy ray-curable resin film (IV) (sometimes abbreviated herein simply as "composition (IV)") containing an energy ray-curable component (a).

[0084] The energy ray-curable resin film and the composition (IV) may further contain other components that do not fall under the category of the energy ray-curable component (a). Examples of the other components include a polymer (b) having no energy ray-curable group, a thermosetting component, a filler, a coupling agent, a crosslinking agent, a photopolymerization initiator, an additive, and a solvent.

[0085] The polymer (b) having no energy ray-curable group is preferably polyvinyl acetal, from the viewpoint of adjusting the above-mentioned Gc300 to an appropriate value and facilitating adjustment of the X value to an appropriate value.

[0086] The thermosetting component, filler, coupling agent, crosslinking agent, photopolymerization initiator, additives, and solvent in the energy ray-curable resin film and composition (IV) are the same as the thermosetting component (B), filler (D), coupling agent (E), crosslinking agent (F), photopolymerization initiator (H), additives (I), and solvent in the above-mentioned thermosetting resin film and composition (III).

[0087] The energy ray-curable resin film and the composition (IV) contain the energy ray-curable component (a), the polymer (b) having no energy ray-curable group, the thermosetting component, the filler, the coupling agent, the crosslinking agent, the photopolymerization initiator, the additive, the solvent, and the like. Each of these components may be one type or two or more types, and when two or more types are used, the combination and ratio thereof can be selected arbitrarily.

[0088] The support sheet constituting the sheet for forming a protective film of the present embodiment may be a known sheet. For example, various resins can be used as the constituent material of the support sheet made of only the base material. Examples of the resin include polyethylene; polyolefins other than polyethylene, such as polypropylene; ethylene-based copolymers (copolymers obtained using ethylene as a monomer); vinyl chloride-based resins (resins obtained using vinyl chloride as a monomer); polystyrene; polycycloolefins; polyesters; copolymers of two or more of the above polyesters; poly(meth)acrylic acid esters; polyurethanes; polyurethane acrylates; polyimides; polyamides; polycarbonates; fluororesins; polyacetals; modified polyphenylene oxides; polyphenylene sulfides; polysulfones; and polyether ketones. Further, examples of the resin include polymer alloys such as mixtures of the polyesters with other resins. Examples of the resin include crosslinked resins in which one or more of the resins exemplified above are crosslinked; and modified resins such as ionomers using one or more of the resins exemplified above.

[0089] In this specification, the term "(meth)acrylic acid" encompasses both "acrylic acid" and "methacrylic acid." The same applies to terms similar to (meth)acrylic acid; for example, "(meth)acrylate" encompasses both "acrylate" and "methacrylate."

[0090] The resin constituting the support sheet consisting of only a substrate may be one type or two or more types, and when two or more types are used, the combination and ratio thereof can be selected arbitrarily.

[0091] From the viewpoints of versatility, the ability to impart heat resistance to the support sheet when the curable resin film provided with the support sheet is thermally cured in the method for producing a chip with a protective film described below, and ease of preventing warpage of the wafer, the resin is preferably a polyester such as polyethylene terephthalate or polybutylene terephthalate; polypropylene, etc. In this case, the support sheet (substrate) may be a single layer or a multi-layer structure of two or more layers, as long as it has one or more layers selected from the group consisting of a layer containing polyester and a layer containing polypropylene film.

[0092] The support sheet, which is made of only the substrate and contains a resin, can be produced by molding a resin composition containing the resin.

[0093] The release film as the support sheet may be made of a material that is releasable itself or may have an easily peelable layer on it, thereby facilitating the peeling of the curable resin film. The release film may be the same as the support sheet made of only the substrate, except that it is made of a material that is releasable itself or has an easily peelable layer on the substrate.

[0094] Examples of the material having releasability include fluororesins. Examples of the easily peelable layer include a layer formed from a release agent such as a silicone-based release agent or an alkyd-based release agent.

[0095] The adhesive sheet serving as the support sheet typically comprises a film-like or sheet-like substrate and an adhesive layer, and may further comprise an intermediate layer between the substrate and the adhesive layer for embedding the protruding electrodes. The substrate in the pressure-sensitive adhesive sheet may be the same as the support sheet consisting of only the substrate, for example. Examples of the adhesive contained in the adhesive layer in the adhesive sheet include acrylic adhesives, rubber adhesives, urethane adhesives, etc. The adhesive layer may be one whose adhesiveness decreases when irradiated with energy rays. Examples of components contained in the intermediate layer in the pressure-sensitive adhesive sheet include cured products of urethane (meth)acrylate compounds, thermoplastic polyolefin resins (thermoplastic resins having structural units derived from olefins), and the like.

[0096] The support sheet may be a backgrind tape, that is, the grinding of the back surface of the wafer, which will be described later, may be performed with the support sheet attached to the curable resin film. Furthermore, the support sheet may not be attached to the curable resin film when the backside of the wafer is ground. For example, the support sheet used in manufacturing method 2 of the manufacturing method of a chip with a protective film described below can be removed before the curing step. In that case, a separate back-grinding tape is attached to the curable resin film when the backside of the wafer is ground. Therefore, it is not essential that the support sheet have the properties required of a back-grinding tape. Furthermore, even if the curing step involves heating the curable resin film and the support sheet deforms due to heating, or if the support sheet has an adhesive layer that softens due to heating, problems such as deformation and softening can be avoided by removing the support sheet with such properties before the curing step.

[0097] The jig adhesive layer may have, for example, a single-layer structure containing an adhesive component, or a multi-layer structure including a core sheet and layers containing the adhesive component provided on both sides of the core sheet. Examples of the layers containing the adhesive component include the same as the pressure-sensitive adhesive layer in the pressure-sensitive adhesive sheet.

[0098] <<Method for manufacturing protective film-forming sheet>> The sheet for forming a protective film of this embodiment can be produced by sequentially laminating the above-mentioned layers (support sheet, curable resin film, jig adhesive layer, etc.) so that they are in a corresponding positional relationship. The method for forming each layer is as described above. Furthermore, the shape of each layer may be adjusted as necessary either before or after lamination.

[0099] For example, when producing the protective film forming sheet, the curable resin film forming composition can be coated on one side of the support sheet and dried as necessary, thereby laminating the curable resin film on the support sheet. In addition, when producing the protective film-forming sheet, a release film is used as a support sheet, and the curable resin film-forming composition is applied to one side (release-treated side) of the release film and dried as necessary to form the curable resin film on the release film, thereby obtaining a protective film-forming sheet. In this way, when a release film is used as a support sheet, after forming a curable resin film on substantially the entire surface of the release film, the curable resin film is cut into the same shape (e.g., circular) as the intended shape of the first region of the release film, and the excess curable resin film is removed to create the second region, which is preferable in that the protective film-forming sheet can be easily obtained. In addition, when a strip-shaped release film is used as the support sheet, the excess curable resin film can be continuously removed to create the second region, which is preferable in that the protective film-forming sheet 2 shown in FIG. 4 can be easily obtained. Furthermore, it is preferable that the sheet for forming a protective film 1 shown in Fig. 2 is obtained in a state in which it is continuously provided on a strip-shaped release film by laminating the exposed surface of the curable resin film of the sheet for forming a protective film 2 (the surface opposite to the release film side) to the adhesive surface of a support sheet which is an adhesive sheet (for example, the exposed surface of the adhesive layer), cutting the adhesive sheet into a concentric circle larger than the curable resin film 12, and continuously removing the excess adhesive sheet. In this case, the release film on the curable resin film can be removed when the sheet for forming a protective film is used.

[0100] <<Manufacturing method for chips with protective film>> A method for manufacturing a chip with a protective film according to one embodiment of the present invention includes a bonding step of heating the curable resin film in the protective film forming sheet according to one embodiment of the present invention and bonding it to a surface of a wafer having protruding electrodes; a curing step of hardening the curable resin film after bonding to form a protective film on the surface of the wafer; and a processing step of dividing the wafer after forming the protective film and cutting the protective film to obtain a chip with a protective film comprising a chip and the protective film provided on the chip after cutting. According to the method for manufacturing a chip with a protective film of this embodiment, the formation of an area in the curable resin film that is not attached to the wafer and that has an increased thickness can be suppressed in the bonding step, and as a result, contamination of the side surface of the wafer or any part of the manufacturing equipment for the chip with a protective film due to the adhesion of excess curable resin film can be suppressed in the steps after the bonding step.

[0101] 6A to 6E are cross-sectional views for schematically explaining an example of a method for manufacturing a chip with a protective film according to this embodiment. Here, we will explain the case where the protective film forming sheet 1 shown in Figures 2 and 3 is used as an example, but the gist of the method for manufacturing a chip with a protective film is the same when the protective film forming sheet 2 shown in Figure 4 or other protective film forming sheets of this embodiment are used.

[0102] In the bonding step, the curable resin film 12 in the protective film-forming sheet 1 is bonded to the surface 9a of the wafer 9 having the protruding electrodes 91 while being heated. As a result, as shown in FIG. 6A , a wafer 101 with a protective film-forming sheet is obtained, which includes the protective film-forming sheet 1 and a wafer 9 provided on the surface 12a of the curable resin film 12 in the protective film-forming sheet 1 opposite the support sheet 11, and in which the base portions of the protruding electrodes 91 in the wafer 9 near the surface 9a are covered with the curable resin film 12. While FIG. 6A shows a state in which the curable resin film 12 covers the tops of the protruding electrodes 91, the tops of the protruding electrodes 91 may be exposed without being covered by the curable resin film 12. Furthermore, when the support sheet 11 is a pressure-sensitive adhesive sheet or a support sheet having a jig adhesive layer, the peripheral portion of the support sheet 11 may be bonded to a jig (not shown), such as a ring frame.

[0103] The support sheet 11 in the protective film forming sheet 1 has a second region 112a on one surface 11a. Therefore, when the curable resin film 12 in the protective film forming sheet 1 is attached to the surface 9a of the wafer 9 having the protruding electrodes, the region of the curable resin film 12 that is not attached to the wafer 9 can be narrowed or eliminated, and the amount of flowing curable resin film can be reduced. Furthermore, the region of the curable resin film 12 that is not attached to the wafer 9, near the peripheral portion, does not become cold. As a result, in the bonding process, even if the curable resin film 12 flows radially outward of the wafer 9 (leftward, rightward, or leftward in Figure 6A) due to the pressure applied during bonding in its thickness direction, i.e., from the area bonded to the wafer 9 (on the first area 111a of the support sheet 11) to the area not bonded to the wafer 9 (on the second area 112a of the support sheet 11), the formation of an area where the thickness of the curable resin film 12 is thicker can be suppressed on the second area 112a of the support sheet 11.

[0104] A plurality of grooves 90 are formed on the surface 9a of the wafer 9 having the protruding electrodes 91, and serve as dividing portions of the wafer 9 when the wafer 9 is divided into individual chips. In this case, in the bonding step, when the curable resin film 12 is bonded to the surface 9a of the wafer 9, the curable resin film 12 is filled into some or all of the areas of the grooves 90. FIG. 6A shows a state in which the curable resin film 12 is filled into all of the areas of the grooves 90.

[0105] The grooves 90 can be formed by, for example, forming cuts in the thickness direction of the wafer 9 from the surface 9a of the wafer 9 using a known dicing method. This method is sometimes referred to as "half cutting" in the art. Examples of dicing methods include, but are not limited to, blade dicing and plasma dicing.

[0106] The depth of the grooves 90 is not particularly limited as long as it is less than the thickness of the wafer 9, but is preferably 30 to 700 μm, more preferably 60 to 600 μm, and even more preferably 100 to 500 μm. When the depth of the grooves 90 is equal to or greater than the lower limit, the grinding surface can easily reach the wafer 9 when the back surface 9b of the wafer 9 is ground in the processing step described below, making it easier to divide the wafer 9. When the depth of the grooves 90 is equal to or less than the upper limit, the strength of the wafer 9 before grinding is increased.

[0107] The width of the groove 90 is preferably 10 to 2000 μm, more preferably 30 to 1000 μm, even more preferably 40 to 500 μm, and particularly preferably 50 to 300 μm. When the width of the groove 90 is equal to or greater than the lower limit, it becomes easier to prevent the individual chips from coming into contact with each other due to grinding vibrations when the back surface 9b of the wafer 9 is ground in the processing step described below. When the width of the groove 90 is equal to or less than the upper limit, the strength of the wafer 9 before grinding becomes higher.

[0108] The height of the protruding electrodes 91 is not particularly limited, but is preferably 30 to 300 μm, more preferably 60 to 250 μm, and even more preferably 80 to 200 μm. When the height of the protruding electrodes 91 is equal to or greater than the lower limit, the functionality of the protruding electrodes 91 can be further improved. When the height of the protruding electrodes 91 is equal to or less than the upper limit, the protruding electrodes 91 can be easily provided at high density, and the possibility of damage to the protruding electrodes 91 when the wafer 9 is handled can be reduced. In this specification, the "height of the protruding electrode" means the height of the protruding electrode at the highest point from the surface of the wafer having the protruding electrode (circuit surface).

[0109] The thickness of the wafer 9 is not particularly limited, but is preferably 100 to 1000 μm, more preferably 200 to 900 μm, and even more preferably 300 to 800 μm. When the thickness of the wafer 9 is equal to or greater than the lower limit, warping due to shrinkage during curing of the curable resin film 12 is easily suppressed. When the thickness of the wafer 9 is equal to or less than the upper limit, the amount of grinding of the back surface 9b of the wafer 9 in the processing step described below is suppressed, and the time required for grinding can be shortened.

[0110] When the curable resin film 12 is attached to the surface 9a of the wafer 9 while being heated, the curable resin film 12 can be heated by a known method. For example, the wafer may be heated by increasing the temperature of a table on which the wafer is placed, and the curable resin film 12 may be heated using the heated wafer as a heat source.

[0111] The temperature (heating temperature) of the curable resin film 12 when the curable resin film 12 is attached to the surface 9a of the wafer 9 while being heated is not particularly limited, but is preferably 50 to 150°C, more preferably 60 to 130°C, and even more preferably 70 to 110°C. When the temperature is equal to or greater than the lower limit, the curable resin film 12 can be more thoroughly filled into the bases of the protruding electrodes 91 and the grooves 90 without gaps. When the temperature is equal to or less than the upper limit, problems caused by excessively high fluidity of the curable resin film 12 can be suppressed.

[0112] The pressure applied to the curable resin film 12 when the curable resin film 12 is attached to the surface 9a of the wafer 9 while being heated (pressure applied in the thickness direction of the wafer 9) is not particularly limited, but is preferably 0.1 to 1.5 MPa, and more preferably 0.3 to 1 MPa. When the pressure is equal to or greater than the lower limit, the curable resin film 12 can be filled more thoroughly into the grooves 90 of the wafer 9 without gaps. When the pressure is equal to or less than the upper limit, damage to the wafer 9 can be significantly suppressed.

[0113] In the bonding step, it is preferable to use a roller to bond the curable resin film 12 to the surface 9a of the wafer 9. When a conventional curable resin film is bonded to the surface 9a of the wafer 9 using a roller, the conventional curable resin film flows from the area bonded to the wafer toward the area not bonded to the wafer, resulting in a noticeable defect in which the thickness of the area not bonded to the wafer becomes thicker than the area bonded to the wafer. This is because the flow direction of the curable resin film is biased toward the direction of movement of the roller. In contrast, in this embodiment, such a defect can be suppressed by using the protective film-forming sheet. That is, in this embodiment, the effects of the present invention are significantly enhanced by using a roller to bond the curable resin film 12 to the surface 9a of the wafer 9 in the bonding step.

[0114] The curable resin film 12 can be attached to the surface 9a of the wafer 9 using a roller by a known method. That is, by contacting the outermost surface of the protective film-forming sheet 1 on the support sheet 11 side (here, the surface of the support sheet 11 opposite the curable resin film 12 side) with the roll surface of a rotating roller, the protective film-forming sheet 1 is fed in the direction of travel of the roller, and the surface 12a of the curable resin film 12 in the protective film-forming sheet 1 opposite the support sheet 11 side is brought into close contact with the surface 9a of the wafer 9, thereby allowing the curable resin film 12 to be attached to the surface 9a of the wafer 9.

[0115] It is preferable to use a wafer 9 whose area when viewed from above on the surface 9a having the protruding electrodes 91 (i.e., the area of ​​the surface 9a in a planar view) is equal to or greater than the area of ​​the surface 12a of the curable resin film 12 opposite the support sheet 11 side (i.e., the area of ​​the surface of the curable resin film 12 that is attached to the wafer 9). In the bonding step, it is preferable to use such a wafer 9 and bond the entire surface 12a (the surface to be bonded to the wafer 9) of the curable resin film 12 to the surface 9a of the wafer 9. In this way, the entire surface 12a of the curable resin film 12 is covered by the surface 9a of the wafer 9, thereby further reducing the amount of curable resin film 12 that protrudes onto the second region 112a of the support sheet 11, and as a result, the formation of an area of ​​the curable resin film 12 that is not attached to the wafer and has a large thickness can be further suppressed.

[0116] In order to further suppress the formation of a region where the thickness of the curable resin film 12 is thick, a combination of the curable resin film 12 and the wafer 9 suitable for use in the bonding step is, for example, a combination of the curable resin film 12 and the wafer 9 having a maximum width (diameter) D 12 A combination of a curable resin film 12 having a width of 140 to 150 mm and a wafer 9 having a diameter of 6 inches; a maximum width (diameter) D 12 A combination of a curable resin film 12 having a diameter of 190 to 200 mm and a wafer 9 having a diameter of 8 inches; a maximum width (diameter) D 12A combination of a curable resin film 12 having a diameter of 290 to 300 mm and a wafer 9 having a diameter of 12 inches; a maximum width (diameter) D 12 An example is a combination of a curable resin film 12 having a diameter of 440 to 450 mm and a wafer 9 having a diameter of 18 inches.

[0117] In the curing step, the curable resin film 12 attached to the wafer 9 is cured to form a protective film 12' on the surface 9a of the wafer 9, as shown in FIG. 6B. This results in a protective film-coated wafer 102 that includes the wafer 9 and a protective film 12' provided on the surface 9a of the wafer 9 that has the protruding electrodes 91. The protective film 12' in the protective film-coated wafer 102 further includes a support sheet 11 on a surface 12b' opposite the wafer 9 side. In FIG. 6B, reference symbol 12a' indicates the surface of the protective film 12' opposite the support sheet 11 side. In the wafer 102 with a protective film, the bases of the protruding electrodes 91 in the wafer 9 near the surface 9a are covered with a protective film 12', and the entire area of ​​the grooves 90 in the wafer 9 is filled with the protective film 12'.

[0118] The curing of the curable resin film 12 may be carried out by a known method according to the properties of the curable resin film 12. For example, if the curable resin film 12 is thermosetting, the curable resin film 12 is cured by heating, and if the curable resin film 12 is energy ray curable, the curable resin film 12 is cured by irradiating it with energy rays.

[0119] When the curable resin film 12 is thermally cured, the heating temperature is preferably 100 to 200° C., more preferably 120 to 150° C. The heating time is preferably 0.5 to 5 hours, more preferably 1 to 3 hours. When the curable resin film 12 is cured with energy rays, the illuminance of the energy rays is 180 to 280 mW / cm 2 The light intensity of the energy ray is preferably 450 to 1000 mJ / cm 2 It is preferable that:

[0120] In the processing step, the wafer 9 (in the protective film-coated wafer 102) after the protective film 12' is formed is divided. As a result, the wafer 9 is divided into individual chips 9', and as shown in Fig. 6C, a protective film-coated wafer divided body 103 is obtained, which includes a plurality of chips 9' and an uncut continuous (single) protective film 12' provided on the surface 9a' of each of the plurality of chips 9' having the protruding electrodes 91.

[0121] The wafer 9 can be divided, for example, by grinding the surface (back surface) 9b of the wafer 9 opposite to the surface 9a having the protruding electrodes 91, using a grinding means such as a grinder. At this time, the wafer 9 is ground from the back surface 9b of the wafer 9 toward the surface 9a until the ground surface reaches the grooves 90 (until the grooves 90 appear). In this way, the thickness of the wafer 9 becomes thinner, and the grooves 90 become dividing points, and the wafer 9 is divided. The back surface 9b of the wafer 9 is ground until the thickness of the chips 9' reaches a desired value.

[0122] In the processing step, next, prior to cutting the protective film 12', a dicing sheet 8 is attached to the back surfaces 9b' of all the chips 9' in the protective film-attached wafer divided body 103, and the support sheet 11 is removed from the protective film 12'. As a result, as shown in Fig. 6D, a dicing sheet stack 104 is obtained in which the protective film-attached wafer divided bodies 103 are provided on one side of the dicing sheet 8 with the chips 9' facing the dicing sheet 8.

[0123] The dicing sheet 8 may be a known one. For example, the dicing sheet 8 may be one consisting of only a substrate, or one comprising a substrate and an adhesive layer provided on one surface of the substrate. When using a dicing sheet 8 comprising the substrate and adhesive layer, the adhesive layer is attached to the back surface 9b' of the chip 9'.

[0124] In this specification, when considering both the protective film forming sheet of this embodiment (for example, the protective film forming sheet 1 shown in Figures 2 and 3, and the protective film forming sheet 2 shown in Figure 4) and the dicing sheet (for example, the dicing sheet 8 shown in Figure 6D), the substrate in the protective film forming sheet of this embodiment is referred to as the "first substrate" and the substrate in the dicing sheet is referred to as the "second substrate" to distinguish between these substrates.

[0125] The second substrate in the dicing sheet 8 and the adhesive layer may both be of known materials. The second substrate may be the same as the first substrate. The pressure-sensitive adhesive layer may be energy ray-curable or non-curable. In this specification, the term "non-curable" means a property that does not cure by any means such as heating or irradiation with energy rays.

[0126] Before attaching the dicing sheet 8 to the protective film-attached wafer divided body 103, the support sheet 11 may be cut, for example, along the outline of the aggregate of chips 9' in the protective film-attached wafer divided body 103, i.e., along a portion corresponding to the outer periphery of the wafer 9 before division. When the protective film-attached wafer divided body 103 is viewed in plan from above the chip 9' side, if the protective film 12' does not fit within the shape of the support sheet 11, the portion of the protective film 12' that protrudes from the support sheet 11 is cut at the same time. Figure 6D shows the case where the support sheet 11 and the protective film 12' are cut in this manner.

[0127] In the processing step, the surface layer of the surface 12b' of the protective film 12' opposite the chip 9' is removed by cleaning, thereby exposing the top of the protruding electrode 91. When the top of the protruding electrode 91 is covered with the curable resin film 12 as shown in FIG. 6A, such cleaning is preferably performed. In the processing step, the protective film 12' is further cut to obtain a plurality of chips 105 with a protective film, each chip 9' and a protective film 120' formed on the chip 9' after cutting, as shown in FIG. 6E. In this specification, the "protective film after cutting" may be simply referred to as the "protective film." More specifically, the protective film 120' after cutting is formed on the surface 9a' of the chip 9' that has the protruding electrode 91.

[0128] The surface layer portion of the surface 12b' of the protective film 12' can be cleaned by a known method such as plasma irradiation.

[0129] The protective film 12' is cut along the outer periphery (in other words, the side surface) of the chip 9'. At this time, it is preferable to cut the protective film 12' filling the space between adjacent chips 9' along the outer periphery (side surface) of the chip 9' and divide it into two. By doing so, the protective film 120' after cutting is also provided on each side surface of adjacent chips 9', and a total of five surfaces of each chip 9', including the surface 9a' having the protruding electrode 91 and the four side surfaces, are protected by the protective film 120'. Therefore, the protective film 120' provides a significantly high protective effect to the chip 9'.

[0130] The protective film 12' can be cut by a known method, for example, by using a known cutting means such as a dicing blade.

[0131] After the processing step, the resulting chip 105 with the protective film is separated from the dicing sheet 8 and picked up. The chip 105 with the protective film can be picked up by a known method.

[0132] When the dicing sheet 8 provided with the adhesive layer is used, the protective film-coated chip 105 can be picked up by peeling it off the adhesive layer. When the adhesive layer is curable, the protective film-attached chip 105 can be picked up more easily by picking it up after the adhesive layer has cured.

[0133] Up to this point, the processing step has been described using an example in which a dicing sheet 8 is used to cut the protective film 12'. However, as explained above, a protective film may be provided on the back surface 9b' of the chip 9' to further protect the chip 9'. In this case, a protective film-forming sheet configured to include a support sheet and a protective film-forming film for forming a protective film on one surface of the support sheet can be used in place of the dicing sheet 8. Here, the support sheet may include a substrate and an adhesive layer, and in this case, the protective film-forming film is provided on the surface of the adhesive layer opposite the substrate side. When the protective film-forming sheet is used, the protective film-forming film is attached to the back surface 9b' of the chip 9'.

[0134] In this specification, when considering both the protective film-forming sheet of this embodiment (for example, protective film-forming sheet 1 shown in Figures 2 and 3, and protective film-forming sheet 2 shown in Figure 4) and the protective film-forming sheet provided with the protective film-forming film, the protective film-forming sheet of this embodiment will be referred to as the "first protective film-forming sheet," and the protective film-forming sheet provided with the protective film-forming film will be referred to as the "second protective film-forming sheet," to distinguish between these protective film-forming sheets. Furthermore, in this case, the support sheet in the sheet for forming a protective film of this embodiment (for example, support sheet 11 shown in Figures 2 and 3 and support sheet 21 shown in Figure 4) is referred to as the "first support sheet," and the support sheet in the sheet for forming a protective film provided with the protective film-forming film is referred to as the "second support sheet," to distinguish between these support sheets. The same applies to the pressure-sensitive adhesive layer provided in the support sheet; the pressure-sensitive adhesive layer in the first support sheet is referred to as the "first pressure-sensitive adhesive layer," and the pressure-sensitive adhesive layer in the second support sheet is referred to as the "second pressure-sensitive adhesive layer," to distinguish between these pressure-sensitive adhesive layers. Furthermore, in this case, the protective film formed from the curable resin film using the protective film forming sheet of this embodiment (for example, protective film 12' shown in Figure 6B, etc.) is referred to as the "first protective film," and the protective film formed from the protective film forming film (for example, the protective film provided on the back surface 9b' of the chip 9') is referred to as the "second protective film," thereby distinguishing between these protective films.

[0135] The second support sheet in the sheet for forming a second protective film may be the same as the first support sheet in the sheet for forming a first protective film.

[0136] The protective film-forming film in the second protective film-forming sheet may be either curable or non-curable. The curable protective film-forming film may be either thermosetting or energy ray-curable, or may have both thermosetting and energy ray-curable properties. The non-curable overcoat-forming film is considered to be an overcoat once it is applied (formed) to the target object (ie, wafer).

[0137] When a second protective film-forming sheet having the curable protective film-forming film is used in the processing step, the second protective film can be formed by curing the protective film-forming film at any stage after the second protective film-forming sheet (the protective film-forming film) is attached to the back surface 9b' of the chip 9'. Also, the protective film-forming film or the second protective film is cut along the outer periphery of the chip 9' at a stage before the chip 105 with the protective film is separated from the second support sheet and picked up.

[0138] When a second protective film forming sheet is used, the protective film-coated chip 105 can be picked up by pulling it away from the second support sheet with the protective film-forming film or second protective film further attached to the back surface 9b' of the chip 9' inside it after cutting. When the second support sheet has a curable adhesive layer, the protective film-attached chip 105 can be picked up more easily by picking it up after the adhesive layer has cured.

[0139] The manufacturing method of the chip with protective film of this embodiment is not limited to the above-mentioned manufacturing method (hereinafter sometimes referred to as "manufacturing method 1") as long as it has the above-mentioned attachment step, curing step, and processing step in this order, and some of the components of the above-mentioned manufacturing method (manufacturing method 1) may be changed, deleted, or added.

[0140] For example, up to this point, we have described manufacturing method 1 in which a protective film forming sheet is attached to a wafer having grooves on the surface having the protruding electrodes, and the back surface of the wafer is ground to separate the wafer into chips.However, it is also possible to use a wafer that does not have the grooves and cut the wafer using a dicing blade, that is, by a so-called full cut, to separate the wafer into chips. Alternatively, a wafer without the grooves may be used, and a modified layer that will be the starting point for division may be formed inside the wafer by laser irradiation in advance. The wafer may then be divided into individual chips by expanding the sheet on which the wafer is mounted, or by utilizing the impact generated when the back surface of the wafer is ground. In these modified examples, the division of the wafer into chips (singulation) and the cutting of the protective film may be performed simultaneously.

[0141] Furthermore, in manufacturing method 1, instead of using a pre-prepared sheet for forming a protective film in the attaching step, the step of completing the sheet for forming a protective film and the attaching step may be performed continuously. More specifically, manufacturing method 1 may include a cutting step immediately before the attaching step, in which the curable resin film formed on substantially the entire surface of the support sheet is cut into the same shape as the shape intended for the first region of the support sheet and excess curable resin film is removed to create the second region, thereby completing the sheet for forming a protective film. By using an apparatus that performs such a cutting step and the attaching step continuously, the completion of the sheet for forming a protective film and the attaching to the wafer can be performed on the same production line.

[0142] 7A to 7E are cross-sectional views for schematically explaining another example of the method for manufacturing a chip with a protective film according to this embodiment (hereinafter, sometimes referred to as "manufacturing method 2"). Manufacturing method 2 described below corresponds to manufacturing method 1 described above, with the order of some of the steps changed.

[0143] In the manufacturing method 2, first, the bonding step is carried out in the same manner as in the manufacturing method 1, to prepare a wafer 101 with a sheet for forming a protective film, as shown in FIG. 7A. In the manufacturing method 2, as in the manufacturing method 1, the formation of an area where the thickness of the curable resin film 12 is thick on the second area 112a of the support sheet 11 can be suppressed.

[0144] In the curing step of manufacturing method 2, prior to curing the curable resin film 12, the support sheet 11 and the curable resin film 12 are cut along the outer periphery of the wafer 9 in the wafer 101 with the protective film-forming sheet. If the support sheet 11 is a pressure-sensitive adhesive sheet or a support sheet having a jig adhesive layer, the peripheral edge of the support sheet 11 may be attached to a jig (not shown) such as a ring frame before cutting the support sheet 11 and the curable resin film 12. Alternatively, the support sheet 11 may be removed from the curable resin film 12 with or without cutting the support sheet 11 and the curable resin film 12.

[0145] In the curing step of manufacturing method 2, the curable resin film 12 after being attached to the wafer 9 is cured in the same manner as in the curing step of manufacturing method 1, thereby forming a protective film 12' on the surface 9a of the wafer 9, as shown in FIG. 7B. This results in a wafer 102 with a protective film having the same configuration as in manufacturing method 1. However, unlike manufacturing method 1, the protective film 12' in the wafer 102 with a protective film may further include a cut support sheet 11 on a surface 12b' opposite the wafer 9 side, or may not include a support sheet 11. FIG. 7B shows a case where the support sheet 11 is not included.

[0146] In the processing step of manufacturing method 2, prior to dividing the wafer 9, the surface portion of the surface 12b' of the protective film 12' opposite the wafer 9 side is removed by cleaning, thereby exposing the upper part of the protruding electrode 91, and further, a backgrinding tape 7 separate from the support sheet 11 is attached to the surface 12b' of the protective film 12' after cleaning.

[0147] In the manufacturing method 2, cleaning of the surface layer portion of the face 12b' of the protective film 12' can be carried out in the same manner as in the manufacturing method 1.

[0148] As explained above, in the attachment step of manufacturing method 2, the formation of an area where the thickness of the curable resin film 12 is increased is suppressed, and therefore, in this step, the protrusion of the protective film 12' from the outer periphery of the wafer 9 is suppressed. Therefore, the backgrinding tape 7 can be stably attached to the surface 12b' of the protective film 12'.

[0149] In the processing step of manufacturing method 2, next, the wafer 9 (in the protective film-coated wafer 102) after the protective film 12' is formed is divided. As a result, the wafer 9 is divided into individual chips 9', and as shown in Fig. 7C, a protective film-coated wafer divided body 103' is obtained, which includes a plurality of chips 9' and an uncut continuous (single) protective film 12' provided on the surface 9a' of the plurality of chips 9' having the protruding electrodes 91. The divided wafer body with a protective film 103' differs from the divided wafer body with a protective film 103 in manufacturing method 1 in that the thickness of the protective film 12' has been made thinner than the original thickness due to cleaning.

[0150] In the manufacturing method 2, the wafer 9 can be divided in the same manner as in the manufacturing method 1.

[0151] In the processing step of manufacturing method 2, next, prior to cutting the protective film 12', a dicing sheet 8 is attached to the back surfaces 9b' of all the chips 9' in the protective film-coated wafer divided body 103', and the backgrinding tape 7 is removed from the protective film 12'. As a result, as shown in Fig. 7D, a dicing sheet stack 104' is obtained in which the protective film-coated wafer divided bodies 103' are provided on one surface of the dicing sheet 8 with the chips 9' facing the dicing sheet 8.

[0152] In the processing step of manufacturing method 2, next, protective film 12' is cut to obtain chip 105 with protective film having the same configuration as in manufacturing method 1, as shown in FIG. 7E.

[0153] In the manufacturing method 2, the protective film 12' can be cut in the same manner as in the manufacturing method 1. In manufacturing method 2, for the same reason as in manufacturing method 1, when cutting protective film 12' along the outer periphery (in other words, the side) of chip 9', it is preferable to cut protective film 12' filled between adjacent chips 9' along the outer periphery (side) of chip 9' and divide it into two.

[0154] After the processing step of manufacturing method 2, the obtained chip 105 with protective film is separated from dicing sheet 8 and picked up in the same manner as in manufacturing method 1.

[0155] In the processing step of manufacturing method 2, similarly to manufacturing method 1, a wafer without the grooves may be used and diced into chips. As in the case of the production method 1, the production method 2 may include the cutting step immediately before the pasting step.

[0156] In either case of manufacturing method 1 or manufacturing method 2, the chip 105 with the protective film obtained above is flip-chip connected to connection pads on a circuit board at the tops of the protruding electrodes 91 therein, thereby fabricating a substrate device (not shown). At this time, the chip 105 with the protective film is connected to the circuit formation surface of the circuit board. For example, if a semiconductor wafer is used as the wafer, the substrate device may be a semiconductor device. [Example]

[0157] The present invention will be described in more detail below with reference to specific examples, although the present invention is not limited to the examples shown below.

[0158] The raw materials used in the production of the composition (III) shown below are as follows: Polymer component (A)-1: Polyvinyl butyral having structural units represented by the following formulas (i)-1, (i)-2, and (i)-3 ("S-LEC BL-10" manufactured by Sekisui Chemical Co., Ltd., weight average molecular weight 25,000, glass transition temperature 59°C).

[0159] [ka] (wherein l1 is approximately 28, m1 is 1 to 3, and n1 is an integer of 68 to 74.)

[0160] Epoxy resin (B1)-1: Liquid modified bisphenol A epoxy resin (DIC Corporation, "Epicron EXA-4850-150," molecular weight 900, epoxy equivalent weight 450 g / eq) Epoxy resin (B1)-4: Dicyclopentadiene-type epoxy resin (DIC "Epicron HP-7200HH", epoxy equivalent 254-264g / eq) Heat curing agent (B2)-1: O-cresol novolac resin (DIC Corporation "Phenolite KA-1160") Curing accelerator (C) - 1:2-phenyl-4,5-dihydroxymethylimidazole ("Curezol 2PHZ-PW" manufactured by Shikoku Chemicals Corporation) Filler (D)-1: Spherical silica modified with epoxy groups ("Admanano YA050C-MKK" manufactured by Admatechs Co., Ltd., average particle size 50 nm) Additive (I)-1: Rheology control agent (polyhydroxycarboxylic acid ester, BYK "BYK-R606")

[0161] [Example 1] Polymer component (A)-1 (100 parts by mass), epoxy resin (B1)-1 (350 parts by mass), epoxy resin (B1)-4 (270 parts by mass), heat curing agent (B2)-1 (190 parts by mass), curing accelerator (C)-1 (2 parts by mass), filler (D)-1 (90 parts by mass), and additive (I)-1 (9 parts by mass) were dissolved or dispersed in methyl ethyl ketone and stirred at 23 ° C. to obtain composition (III) for forming a thermosetting resin film, in which the total concentration of all components other than the solvent was 45% by mass. Note that the amounts of all components other than the solvent shown here are the amounts of the target product excluding the solvent.

[0162] A release film ("SP-PET381031" manufactured by Lintec Corporation, thickness 38 μm) made of polyethylene terephthalate, one side of which had been treated for release by silicone treatment, was used. Composition (III) obtained above was applied to the release-treated surface, and the resulting film was dried by heating at 120°C for 2 minutes to form a thermosetting resin film with a thickness of 30 μm. Next, this thermosetting resin film was processed together with the release film into a circular shape having a diameter of 170 mm to prepare a test piece with a release film. The entire exposed surface of the obtained test piece (in other words, the surface opposite to the side with the release film) was bonded to the surface of a transparent strip-shaped backgrind tape ("E-8180" manufactured by Lintec Corporation) to obtain a laminate. The resulting laminate was constructed by laminating the backgrind tape, the test piece (thermosetting resin film), and the release film in this order in the thickness direction.

[0163] [Example 2] A laminate was obtained in the same manner as in Example 1, except that the thickness of the thermosetting resin film was changed to 45 μm and the backgrind tape to be attached was changed to "E-8510HR" manufactured by Lintec Corporation.

[0164] Furthermore, 20 sheets of the same thermosetting resin film as above were separately prepared, except that the thickness was 50 μm instead of 45 μm, and these were stacked and cut to obtain disk-shaped test pieces with a thickness of 1 mm and a diameter of 25 mm. Viscoelasticity measurements were performed on the test pieces using a viscoelasticity measuring device ("MCR301" manufactured by Anton Paar), and Gc1 and Gc300 were measured, and the X value was calculated, as shown below. Gc1=115000Pa Gc300=3900Pa X value=29

[0165] The groove filling property of the thermosetting resin film in the laminate obtained above was evaluated by the following procedure, and the result was "A". (1) Preparation of wafers for semiconductor chip fabrication A 12-inch silicon wafer (750 μm thick) was used as a wafer for manufacturing semiconductor chips, with the groove width of the half-cut portion of the silicon wafer, i.e., the groove depth, being 60 μm. (2) Evaluation method The release film was removed from the laminate, and the surface (exposed surface) of the thermosetting resin film thus exposed was attached to the half-cut surface of a wafer for producing semiconductor chips while pressing under the following conditions. - Application device: Fully automatic application machine (manufactured by Lintec Corporation, product name "RAD-3510") Roller pressure: 0.5MPa Roller height: -400μm Application speed: 5mm / sec Application temperature: 90℃ Next, the backgrinding tape was peeled off from the thermosetting resin film, and the semiconductor chip fabrication wafer with the thermosetting resin film attached was heated at 130°C for 4 hours to harden the thermosetting resin film and form a protective film.The semiconductor chip fabrication wafer was then cut at the half-cut portions (grooves) from the half-cut formation surface to the back surface, and the filling of the protective film into the half-cut portions (grooves) was evaluated using an optical microscope (Keyence Corporation "VHX-1000").The filling evaluation criteria were as follows. S: No distortion is observed in the shape of the protective film, and the filling property is the best. A: Although some distortion is observed in the shape of the protective film near the opening of the groove, the filling property is good. B: Poor filling properties. [Industrial Applicability]

[0166] The present invention can be used to manufacture chips having protruding electrodes and a protective film on the surface having the protruding electrodes. A chip having such a protective film is suitable for fabricating a substrate device by flip-chip connecting it to connection pads on a circuit board. [Explanation of symbols]

[0167] 1,2... Sheet for forming protective film, 11,21... Support sheet, 11a,21a... One side of the support sheet (the side of the support sheet facing the curable resin film), 111a... First region on one side of the support sheet, 112a... Second region on one side of the support sheet, 12... Curable resin film, 12a... Side of the curable resin film opposite to the support sheet side, 12'... Protective film, 120'... Protective film after cutting, 9... Wafer, 91... Protruding electrodes on the wafer, 9a... Surface of the wafer having the protruding electrodes (circuit surface), 90... Groove on the wafer, 9'... Chip, 105... Chip with protective film, D 12 Maximum width (diameter) of the curable resin film, T 12Thickness of the curable resin film

Claims

1. A sheet for forming a protective film, comprising a support sheet and a curable resin film provided on one surface of the support sheet, the curable resin film is a resin film that is attached to a surface of a wafer having protruding electrodes and cured to form a protective film on the surface of the wafer; The support sheet has, on the one surface thereof, a first region in which the curable resin film is provided, and a second region surrounding the first region and in which the curable resin film is not provided, A strain was generated in a test piece of the curable resin film having a diameter of 25 mm and a thickness of 1 mm under conditions of a temperature of 90°C and a frequency of 1 Hz, and the storage elastic modulus of the test piece was measured. When the storage elastic modulus of the test piece when the strain of the test piece was 1% was defined as Gc1 and the storage elastic modulus of the test piece when the strain of the test piece was 300% was defined as Gc300, the following formula was obtained: X=Gc1 / Gc300 The sheet for forming a protective film has an X value calculated by the above formula of 19 or more and less than 10,000.

2. The sheet for forming a protective film according to claim 1 , wherein the thickness of the curable resin film is 25 μm or more.

3. The sheet for forming a protective film according to claim 1 or 2, wherein the maximum width of the curable resin film is 140 to 150 mm, 190 to 200 mm, 290 to 300 mm, or 440 to 450 mm.

4. The sheet for forming a protective film according to any one of claims 1 to 3, wherein the support sheet is circular.

5. The sheet for forming a protective film according to claim 4 , wherein the support sheet is an adhesive sheet or has a jig adhesive layer along the outer periphery of the support sheet.

6. The sheet for forming a protective film according to any one of claims 1 to 3, wherein the support sheet is a release film.

7. The sheet for forming a protective film according to any one of claims 1 to 6, wherein grooves that become division points of the wafer are formed on the surface of the wafer.

8. a bonding step of bonding the curable resin film in the sheet for forming a protective film according to any one of claims 1 to 7 to a surface of a wafer having protruding electrodes while heating the curable resin film; a curing step of forming a protective film on the surface of the wafer by curing the curable resin film after the application; A method for manufacturing a chip with a protective film, comprising a processing step of dividing the wafer after forming the protective film and cutting the protective film to obtain a chip with a protective film comprising a chip and the protective film provided on the chip after cutting.

9. The wafer has an area of ​​the surface in a plan view equal to or greater than the area of ​​the surface of the curable resin film to be attached to the wafer, The method for manufacturing a chip with a protective film according to claim 8 , wherein in the attaching step, the entire attachment surface of the curable resin film is attached to the surface of the wafer.

10. a groove that will be a dividing point of the wafer is formed on the surface of the wafer, 10. The method for manufacturing a chip with a protective film according to claim 8, wherein in the attaching step, the curable resin film is filled into the grooves when the curable resin film is attached to the surface of the wafer.

11. 11. The method for manufacturing a chip with a protective film according to claim 8, wherein in the attaching step, the curable resin film is attached to the surface of the wafer using a roller.

12. A laminate obtained by forming a thermosetting resin film on a release-treated surface of a release film, processing the thermosetting resin film together with the release film into a circular shape, and bonding the entire surface of the surface opposite to the side provided with the release film to the surface of a strip-shaped backgrind tape, A strain was generated in a test piece of the curable resin film having a diameter of 25 mm and a thickness of 1 mm under conditions of a temperature of 90°C and a frequency of 1 Hz, and the storage elastic modulus of the test piece was measured. When the storage elastic modulus of the test piece when the strain of the test piece was 1% was defined as Gc1 and the storage elastic modulus of the test piece when the strain of the test piece was 300% was defined as Gc300, the following formula was obtained: X=Gc1 / Gc300 The laminate has an X value calculated by the above formula of 19 or more and less than 10,000.

13. A laminate comprising a release film, a thermosetting resin film provided on one release-treated surface of the release film, and a backgrind tape provided on the surface of the thermosetting resin film opposite to the release film side, wherein the planar shapes of the release film and the thermosetting resin film are both circular, the release film and the thermosetting resin film are arranged such that the positions of their outer peripheries coincide with each other in the radial direction, and the backgrind tape is strip-shaped; A strain was generated in a test piece of the curable resin film having a diameter of 25 mm and a thickness of 1 mm under conditions of a temperature of 90°C and a frequency of 1 Hz, and the storage elastic modulus of the test piece was measured. When the storage elastic modulus of the test piece when the strain of the test piece was 1% was defined as Gc1 and the storage elastic modulus of the test piece when the strain of the test piece was 300% was defined as Gc300, the following formula was obtained: X=Gc1 / Gc300 The laminate has an X value calculated by the above formula of 19 or more and less than 10,000.

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