Method for producing adhesive film
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Filing Date
- 2024-08-01
- Publication Date
- 2026-05-11
Abstract
Description
Adhesive film manufacturing method
[0001] The present disclosure relates to a method for producing an adhesive film.
[0002] An example of a conventional adhesive film is a laminate sheet support for die attachment described in Patent Document 1. This conventional laminate sheet support for die attachment includes a long substrate film and a plurality of laminate films for die attachment that are dispersed and arranged in the longitudinal direction of the substrate film on one side of the substrate sheet.
[0003] The die-attach laminate film is composed of a die-attach film on the base film side and a dicing film in the shape of a die-attach film. A protective film having the same thickness as the die-attach laminate film is disposed on one side of the base film so as to surround each of the die-attach laminate films. By disposing the protective film in this manner, the die-attach laminate film can be protected from pressure, for example, when the adhesive film is wound into a roll, and deformation of the laminate film, transfer of winding marks, etc. can be suppressed.
[0004] Japanese Patent Application Laid-Open No. 2006-202927
[0005] For example, a roll-to-roll method is used to manufacture the adhesive film described above. In this method, a substrate film having an adhesive layer on one side thereof is unwound from a raw roll at a constant transport speed, and the adhesive layer is precut into a predetermined pattern using a roll blade or the like. After precutting, unnecessary portions of the adhesive layer are peeled off from the substrate film, thereby forming an adhesive layer of the predetermined pattern on one side of the substrate film.
[0006] However, in such an adhesive film manufacturing process, depending on the shape of the precut adhesive layer, the peel strength of the adhesive layer at the unnecessary portion may exceed the breaking strength, and when the unnecessary portion of the adhesive layer is peeled off, defects such as breakage or chipping may occur in the unnecessary portion. If such defects occur, it may become impossible to peel off the unnecessary portion while winding the film at a constant transport speed, and the manufacturing efficiency of the adhesive film may decrease.
[0007] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a method for manufacturing an adhesive film that can suppress breakage or chipping of unnecessary parts even when the unnecessary parts are peeled off while being wound up at a constant conveying speed, thereby improving manufacturing efficiency.
[0008] A method for manufacturing an adhesive film according to one aspect of the present disclosure includes a payout step in which a long substrate film having an adhesive layer on one side thereof is payout at a predetermined conveying speed, a cutting step in which the adhesive layer is pre-cut along cutting lines of a predetermined pattern, and a peeling step in which unnecessary portions of the adhesive layer are peeled off from one side of the substrate film to form a plurality of adhesive layers having a pattern based on the cutting lines at predetermined intervals on one side of the substrate film, wherein in the cutting step, the unnecessary portions are divided along dividing lines that divide the substrate film in the width direction.
[0009] In this method for producing an adhesive film, when the adhesive layer is pre-cut along cutting lines of a predetermined pattern in the cutting step, unnecessary portions of the adhesive layer are divided along dividing lines that divide the base film widthwise. By dividing the unnecessary portions of the adhesive layer in advance in the base film widthwise, the width of each divided unnecessary portion is reduced, and the peel strength of the adhesive layer in the unnecessary portions is prevented from exceeding the breaking strength. This makes it possible to prevent breakage or chipping of the unnecessary portions even when the unnecessary portions are peeled off while the film is being wound up at a constant conveying speed in the peeling step, thereby improving the manufacturing efficiency of the adhesive film.
[0010] In the cutting step, parting lines may be formed so as to connect the cutting lines corresponding to the plurality of adhesive layers. In this case, the divided unnecessary portions are securely separated from each other, so that breakage or chipping of the unnecessary portions can be more reliably prevented.
[0011] In the cutting step, the dividing lines may be formed linearly along the extending direction of the base film. In this case, by forming the dividing lines in a simple shape, it is possible to more reliably prevent breakage or chipping of unnecessary portions.
[0012] The thickness of the adhesive layer may be 10 μm or less. If the thickness of the adhesive layer is 5 μm or less, the peel strength of the adhesive layer at the unnecessary portion is likely to exceed the breaking strength, and it is thought that the unnecessary portion will frequently break or chip when peeled. In contrast, by dividing the unnecessary portion in advance using the dividing line as described above, it is possible to suitably suppress breakage or chipping of the unnecessary portion even when the thickness of the adhesive layer is small.
[0013] According to the present disclosure, even when the unnecessary portions are peeled off while being wound at a constant transport speed, breakage or chipping of the unnecessary portions can be suppressed, thereby improving manufacturing efficiency.
[0014] 1 is a schematic plan view showing an adhesive film manufactured using an adhesive film manufacturing method according to an embodiment of the present disclosure. It is a cross-sectional view taken along line II-II in FIG. 1. (a) is a schematic plan view showing the state of the film in the unwinding step, and (b) is a cross-sectional view taken along line III-III in (a). (a) is a schematic plan view showing the state of the film in the cutting step, and (b) is a cross-sectional view taken along line IV-IV in (a). It is a schematic perspective view showing a roll blade used in the cutting step. (a) is a schematic plan view showing the state of the film in the peeling step, and (b) is a cross-sectional view taken along line IV-IV in (a). It is a schematic perspective view showing the configuration of a peeling roller used in the peeling step. It is a schematic plan view showing the state of breakage or chipping of unnecessary portions that may occur in a comparative example. (a) to (c) are schematic plan views showing modified examples of the cutting step.
[0015] Hereinafter, a preferred embodiment of a method for producing an adhesive film according to one aspect of the present disclosure will be described in detail with reference to the drawings.
[0016] Fig. 1 is a schematic plan view showing an adhesive film manufactured using an adhesive film manufacturing method according to an embodiment of the present disclosure. Fig. 2 is a cross-sectional view taken along line II-II in Fig. 1. The adhesive film 1 shown in Figs. 1 and 2 is a film used, for example, in the manufacturing process of a semiconductor device. The adhesive film 1 is used, for example, to fix a semiconductor wafer to a ring frame in a backgrinding process, or to bond a semiconductor chip to a circuit board or the like in a bonding process. The adhesive film 1 may be stored in a rolled state when not in use.
[0017] 1 and 2, the adhesive film 1 is composed of a long base film 2, and an adhesive layer 3 and a pressure-sensitive adhesive film 4 provided on one side of the base film 2. The adhesive layer 3 is arranged on one side of the base film 2, and the pressure-sensitive adhesive film 4 is arranged on one side of the base film 2 so as to cover the adhesive layer 3. Although not shown in the figures, the pressure-sensitive adhesive film 4 is composed of a base film and a pressure-sensitive adhesive layer, and is arranged on one side of the base film 2 with the pressure-sensitive adhesive layer facing the adhesive layer 3.
[0018] The base film 2 is a film-like portion that serves as the base of the adhesive film 1. Examples of materials that can be used for the base film 2 include polyethylene terephthalate, semi-aromatic polyester films such as polybutylene terephthalate and polyethylene naphthalate, wholly aromatic polyester films, liquid crystalline aromatic polyester films, polyamide films, polyimide films, and polyamideimide films. The surface of the base film 2 may be subjected to a release treatment using silicone or the like.
[0019] The adhesive layer 3 is a film-like portion, such as a DAF (Die Attach Film). In this embodiment, the thickness of the adhesive layer 3 is 5 μm or less. Examples of materials constituting the adhesive layer 3 include electrically insulating thermosetting resins. Examples of thermosetting resins include epoxy resins, bismaleimide resins, triazine resins, polyimide resins, polyamide resins, cyanoacrylate resins, phenolic resins, unsaturated polyester resins, melamine resins, urea resins, polyurethane resins, polyisocyanate resins, furan resins, resorcinol resins, xylene resins, benzoguanamine resins, diallyl phthalate resins, silicone resins, polyvinyl butyral resins, siloxane-modified epoxy resins, siloxane-modified polyamideimide resins, and acrylate resins. These resins can be used alone or as a mixture of two or more. The adhesive layer 3 may contain acrylic rubber. In this case, the acrylic rubber content in the adhesive layer 3 may be, for example, 34% or less.
[0020] The adhesive film 4 is, for example, a film-like portion called a dicing tape. The adhesive film 4 is configured to include one or more adhesive layers and one or more base film layers. Here, the adhesive film 4 is configured from one adhesive layer and one base film layer. The thickness of the adhesive film 4 may be, for example, 10 μm to 200 μm, or may be 20 μm to 150 μm.
[0021] Examples of the substrate layer of the PSA film 4 include plastic films such as polyester film, polytetrafluoroethylene film, polyethylene film, polypropylene film, and polymethylpentene film. Among these, polyester film is preferred, and polyethylene terephthalate film is more preferred. The substrate layer may be a mixture of two or more materials selected from the above materials, or a multilayer of the above films. The thickness of the substrate layer may be, for example, 10 μm to 195 μm, or 20 μm to 150 μm.
[0022] The adhesive layer of the adhesive film 4 preferably has adhesive strength at room temperature and the necessary adhesive strength to the adherend. The adhesive layer preferably has the property of being cured (i.e., its adhesive strength is reduced) by high-energy rays such as radiation or heat, but more preferably is easily peelable from the base film 2 and the adhesive layer 3 without the application of high-energy rays such as radiation or heat. The adhesive layer may be a pressure-sensitive adhesive layer. The adhesive layer can be formed using, for example, acrylic resin, various synthetic rubbers, natural rubber, or polyimide resin. The thickness of the adhesive layer may be, for example, 5 μm to 100 μm, or 10 μm to 80 μm.
[0023] As shown in Fig. 1 , the adhesive layer 3 and the adhesive film 4 described above are separated into a plurality of functional layers 6 and a plurality of protective layers 7 on one side of the base film 2. In this embodiment, the functional layer 6 is a laminate of the adhesive layer 3 and the adhesive film 4, and the protective layer 7 is the adhesive film 4 (see Fig. 2 ). The functional layer 6 and the protective layer 7 are formed by pre-cutting the adhesive layer 3 and the adhesive film 4 into a predetermined pattern, and then peeling off the unnecessary portions of each from one side of the base film 2.
[0024] The functional layers 6, 6, the protective layers 7, 7, and the functional layer 6 and the protective layer 7 are spaced apart by peeling off the unnecessary portions after precutting. In this embodiment, the unnecessary portions are peeled off using a peeling roller, so the spaced apart portions formed by peeling off the unnecessary portions (i.e., the spaced apart portions between the functional layers 6, 6, the spaced apart portions between the protective layers 7, 7, and the spaced apart portions between the functional layer 6 and the protective layer 7) are integrally connected in the extension direction of the base film 2. In the spaced apart portions, the adhesive layer 3 and the pressure-sensitive adhesive film 4 are peeled off, exposing one side of the base film 2.
[0025] The functional layers 6 are used in the manufacturing process of the semiconductor device. As shown in FIG. 1 , each of the functional layers 6 has a perfect circular shape in a plan view of the base film 2, and is arranged at a predetermined interval in the extending direction of the base film 2. The planar shape of the functional layers 6 does not necessarily have to be a perfect circle, and may be other circular shapes such as an ellipse or an oval. In the functional layer 6, a marker may be attached at a predetermined position on the adhesive film 4 (for example, a portion that protrudes outward beyond the adhesive layer 3). The marker can be formed using, for example, a screen printing method, a stamp method, an inkjet method, or the like.
[0026] The protective layer 7 is a portion that protects the functional layer 6 from pressure when the adhesive film 1 is wound into a roll. As shown in Figures 1 and 2 , the protective layer 7 extends in the extension direction of the base film 2 at both widthwise edge portions of the base film 2 so as to surround each functional layer 6. In this embodiment, the protective layers 7, 7 at both widthwise edge portions of the base film 2 are arranged symmetrically with respect to the width direction of the base film 2.
[0027] 1 , the protective layer 7 has concave portions 7 a and convex portions 7 b that are alternately arranged along the extending direction of the base film 2. The concave portions 7 a and the convex portions 7 b both face toward the center in the width direction of the base film 2. The concave portions 7 a of one protective layer 7 and the concave portions 7 a of the other protective layer 7 face each other in the width direction, and the convex portions 7 b of one protective layer 7 and the convex portions 7 b of the other protective layer 7 face each other in the width direction, so that the circular functional layer 6 is surrounded by the protective layer 7.
[0028] Next, a method for producing the adhesive film 1 will be described.
[0029] The method for producing an adhesive film according to this embodiment includes a feeding step (step S01), a cutting step (step S02), and a peeling step (step S03). In this embodiment, these steps are performed by a roll-to-roll method.
[0030] 3(a) and 3(b), the unwinding step S01 is a step of unwinding a long base film having an adhesive layer on one side at a predetermined transport speed. Here, a raw roll of a long base film 2 having an adhesive layer 3 on one side is unwound from a unwinding roller, and the base film 2 is conveyed toward the installation position of a roll blade 11 (see FIG. 6) that performs the cutting step S02 while being applied with a certain tension by a plurality of conveying rollers or the like.
[0031] 4( a) and 4(b), the cutting step S02 is a step of pre-cutting the adhesive layer 3 along cutting lines S of a predetermined pattern. In the cutting step S02, the adhesive layer 3 is pre-cut along circular cutting lines S set at predetermined intervals in the extending direction of the base film 2 in a plan view of the base film 2 (see FIG. 4(a)). The circular cutting lines S become the adhesive layer 3 that will ultimately constitute the functional layer 6, and the area outside the circular cutting lines S becomes the unnecessary portion F that will be peeled off in the peeling step S03.
[0032] In the cutting step S02, the unnecessary portion F is divided along a division line D that divides the base film 2 in the width direction. Here, the division line D is formed so as to connect circular cutting lines S, S that are arranged at a predetermined interval in the extension direction of the base film 2. In the example of Fig. 4(a) , a linear division line D that extends along the extension direction of the base film 2 is formed at the center of the base film 2 in the width direction, and adjacent circular cutting lines S, S in the extension direction of the base film 2 are connected by the division line D.
[0033] The division line D divides the unnecessary portion F into an unnecessary portion FA on one side in the width direction of the base film 2 and an unnecessary portion FB on the other side in the width direction of the base film 2. In the unnecessary portions FA and FB, the width between the circular cutting lines S, S aligned in the extension direction of the base film 2 (the width in the width direction of the base film 2) is approximately half that of the unnecessary portion F before division. Therefore, the peeled area of each of the unnecessary portions FA and FB can be made smaller than when the unnecessary portion F is peeled off as is.
[0034] Fig. 5 is a schematic perspective view showing the configuration of the roll blade 11 used in the cutting step S02. As shown in Fig. 6, the peripheral surface 11a of the roll blade 11 is provided with a plurality of circular first blades 12A corresponding to the circular cutting lines S set at predetermined intervals, and linear second blades 12B connecting adjacent first blades 12A, 12A. In the cutting step S02, the roll blade 11 is pressed against the adhesive layer 3 on one side of the long substrate film 2 being transported at a predetermined transport speed while rotating, to continuously form cutting lines S and division lines D in the adhesive layer 3 in the extending direction of the substrate film 2.
[0035] From the viewpoint of more reliably cutting the adhesive layer 3, in the cutting step S02, the roll blade 11 may be pressed against the adhesive layer 3 on one side of the long base film 2 so that the first blade 12A and the second blade 12B reach one side of the base film 2. In this case, a cut trace Fa caused by the first blade 12A and the second blade 12B is formed on one side of the base film 2 to a depth that does not reach the other side of the base film 2. The cut trace Fa may remain on one side of the base film 2 after peeling off the unnecessary portion F of the adhesive layer 3 (see FIG. 6( a)). The cut trace Fa may also remain on one side of the base film 2 in the adhesive film 1 finally obtained (see FIG. 1).
[0036] The peeling step S03 is a step of peeling off the unnecessary portions F of the adhesive layer 3 from one side of the base film 2. In the peeling step S03, by peeling off the unnecessary portions F of the adhesive layer 3 from one side of the base film 2, a plurality of adhesive layers 3 having a pattern based on the cutting lines S are formed at predetermined intervals on one side of the base film 2, as shown in Figures 6(a) and 6(b). In this embodiment, the peeling step S03 is performed using, for example, a peeling roller 21 shown in Figure 7. By wrapping the unnecessary portions F of the adhesive layer 3 around the peripheral surface 21a of the peeling roller 21, the unnecessary portions F of the adhesive layer 3 are continuously peeled off from one side of the long base film 2 being transported at a predetermined transport speed.
[0037] As described above, the unnecessary portion F of the adhesive layer 3 is divided by the dividing line D into an unnecessary portion FA on one side in the width direction of the base film 2 and an unnecessary portion FB on the other side in the width direction of the base film 2. Therefore, when the unnecessary portion F of the adhesive layer 3 is peeled off using the peeling roller 21, the unnecessary portion FA and the unnecessary portion FB are wound around the peeling roller 21 in a state where they are separated from each other.
[0038] After the peeling step S03 is performed, a plurality of circular adhesive layers 3 are arranged at predetermined intervals in the extending direction of the base film 2 on one side of the base film 2. Thereafter, an adhesive film 4 is laminated over the entire surface of one side of the base film 2 so as to cover the circular adhesive layers 3, and the adhesive film 4 is precut into a circle that is slightly larger than the adhesive layer 3. Then, unnecessary portions of the adhesive film 4 are peeled off from one side of the base film 2, and a functional layer 6 and a protective layer 7 are formed, thereby obtaining the adhesive film 1 shown in Figures 1 and 2.
[0039] As described above, in this adhesive film manufacturing method, when the adhesive layer 3 is pre-cut along cutting lines S of a predetermined pattern in the cutting step S02, the unnecessary portion F of the adhesive layer 3 is divided into unnecessary portions FA and FB by a dividing line D that divides the base film 2 in the width direction.
[0040] In the adhesive film 101 of the comparative example in which the unnecessary portion F is not divided, it is considered that the peel strength of the adhesive layer 103 in the unnecessary portion F (peel strength from one side of the base film 102) exceeds the breaking strength. If the peel strength of the adhesive layer 103 in the unnecessary portion F exceeds the breaking strength, problems such as breakage or chipping may occur in the unnecessary portion F when the unnecessary portion F is peeled off with the peeling roller 21 in the peeling step S03, and for example, as shown in Figure 8, part of the unnecessary portion F may remain on one side of the base film 102. If such a problem occurs, it may become impossible to peel off the unnecessary portion while winding the film at a constant transport speed, which may reduce the manufacturing efficiency of the adhesive film.
[0041] To address this problem, in this embodiment, the unnecessary portion F of the adhesive layer 3 is divided in advance in the width direction of the base film 2, thereby reducing the width of each of the divided unnecessary portions FA, FB and preventing the peel strength of the adhesive layer 3 at the unnecessary portions FA, FB from exceeding the breaking strength. As a result, when the unnecessary portions FA, FB are peeled while being wound up at a constant transport speed in the peeling step S03, breaking or chipping of the unnecessary portions FA, FB can be prevented, and the manufacturing efficiency of the adhesive film 1 can be improved.
[0042] In this embodiment, in the cutting step S02, the division lines D are formed so as to connect the cutting lines S, S corresponding to the plurality of adhesive layers 3. This ensures that the divided unnecessary portions FA, FB are firmly separated from each other, thereby more reliably preventing breakage or chipping of the unnecessary portions FA, FB. Also, in this embodiment, in the cutting step S02, the division lines D are formed in a straight line along the extending direction of the base film 2. In this way, by forming the division lines D in a simple shape, it is more reliably possible to prevent breakage or chipping of the unnecessary portions FA, FB.
[0043] In this embodiment, the thickness of the adhesive layer 3 is 5 μm or less. If the thickness of the adhesive layer 3 is 5 μm or less, the peel strength of the adhesive layer 3 at the unnecessary portion F is likely to exceed the breaking strength, and it is thought that the unnecessary portion F will frequently break or chip when peeled off. In contrast, by dividing the unnecessary portion F into unnecessary portions FA and FB in advance using the division line D as described above, it is possible to suitably suppress breakage or chipping of the unnecessary portions FA and FB even when the thickness of the adhesive layer 3 is small.
[0044] In this embodiment, the adhesive layer 3 contains acrylic rubber, and the acrylic rubber content in the adhesive layer 3 is 34% or less. If the acrylic rubber content in the adhesive layer 3 is 34% or less, the peel strength of the adhesive layer 3 at the unnecessary portion F is likely to exceed the breaking strength, and it is thought that breaking or chipping of the unnecessary portion F will frequently occur when the unnecessary portion F is peeled off. In contrast, by dividing the unnecessary portion F into unnecessary portions FA and FB in advance using the division line D as described above, it is possible to suitably suppress breaking or chipping of the unnecessary portions FA and FB even if the acrylic rubber content in the adhesive layer 3 is low.
[0045] The present disclosure is not limited to the above embodiment. For example, in the above embodiment, a linear dividing line D is formed so as to connect the cutting lines S, S corresponding to the plurality of adhesive layers 3, but the shape of the dividing line D is not limited to this, and various modifications can be applied from the viewpoint of reducing the peel strength of the adhesive layer 3 at the unnecessary portion F relative to the breaking strength.
[0046] 9( a), wavy dividing lines D may be formed so as to connect the cutting lines S, S corresponding to the plurality of adhesive layers 3. The shape of the dividing lines D is not limited to wavy lines, and may be other shapes such as sawtooth or comb-like. When the cutting lines S are linear, the cutting lines S may extend obliquely relative to the extending direction of the base film 2.
[0047] The division line D does not necessarily have to be continuous between adjacent cutting lines S, S in the extension direction of the base film 2. For example, as shown in FIG. 9( b), the division line D may be divided at the center between adjacent cutting lines S, S in the extension direction of the base film 2. The division line D may be in the form of a perforation, for example, as shown in FIG. 9( c). In FIGS. 9( b) and 9( c), the unnecessary portion F may be divided into unnecessary portions FA and FB along the division line D during the peeling step S03. Even in such a configuration, the same effects as those of the above embodiment can be achieved.
[0048] 1... adhesive film, 2... base film, 3... adhesive layer, F (FA, FB)... unnecessary portion, S... cutting line, D... division line.
Claims
1. A feeding step in which a long base film with an adhesive layer on one side is fed out at a predetermined transport speed, A cutting step of pre-cutting the adhesive layer along a predetermined pattern of cutting lines, The system includes a peeling step of peeling off the unnecessary portion of the adhesive layer from one side of the base film and forming a plurality of adhesive layers having a pattern based on the cutting line at predetermined intervals on one side of the base film, A method for manufacturing an adhesive film, wherein in the cutting step, the unnecessary portion is divided by a dividing line that divides the base film in the width direction.
2. The method for manufacturing an adhesive film according to claim 1, wherein in the cutting step, the dividing lines are formed so as to connect the cutting lines corresponding to the plurality of adhesive layers.
3. The method for manufacturing an adhesive film according to claim 1, wherein in the cutting step, the dividing line is formed in a straight line along the extending direction of the base film.
4. The method for manufacturing an adhesive film according to any one of claims 1 to 3, wherein the thickness of the adhesive layer is 10 μm or less.