Protective film, method for manufacturing a protective film, and method for manufacturing a CMOS sensor module

Abstract

The present invention provides a protective film that suppresses the lifting of individual protective film segments from the release substrate in a protective film laminate after individual segment processing, and also suppresses the retention of silicone-based curing adhesive on the cover glass after the individual protective film segments are heated at high temperatures, and a method for manufacturing the same. [Solution] The protective film 1 comprises a polyimide substrate 2 and a silicone-based curable adhesive layer 3 disposed on the polyimide substrate 2. The silicone-based curable adhesive layer 3 is obtained by curing an adhesive composition containing curable silicone, a platinum catalyst, and a silane coupling agent. The curable silicone contains a mild adhesive component (liquid A) and a strong adhesive component (liquid B). In the adhesive composition, the mass ratio of the mild adhesive component to the strong adhesive component (liquid A:liquid B) is in the range of 99:1 to 75:25. In the adhesive composition, the content of the silane coupling agent per 100 parts by mass of curable silicone is greater than 0 parts by mass and 10 parts by mass or less.

Description

Technical Field

[0001] The present technology relates to a protective film, a method for producing the protective film, and a method for producing a CMOS (Complementary Metal Oxide Semiconductor) sensor module.

Background Art

[0002] FIG. 1 is a cross-sectional view showing an example of an image sensor board used in the method for producing a CMOS sensor module. The image sensor board 100 includes, for example, as shown in FIG. 1, a housing member 101, a CMOS image sensor 102 disposed on the housing member 101, a cover glass 103 disposed on the CMOS image sensor 102 to protect the CMOS image sensor 102, and a conductive material 104 formed on the surface side of the housing member 101 opposite to the side where the CMOS image sensor 102 is disposed. The image sensor board 100 is connected to another member via the conductive material 104 by, for example, a reflow process. Thereby, a CMOS sensor module in which the image sensor board 100 and another member are connected is obtained. When the image sensor board 100 is subjected to the reflow process, a protective film 105 is attached to the surface of the cover glass 103 opposite to the side where the CMOS image sensor 102 is disposed, in order to protect the surface of the CMOS image sensor 102 (see, for example, Patent Documents 1 and 2). The protective film 105 is usually peeled off from the surface of the cover glass 103 after the reflow process.

[0003] FIG. 2 is a cross-sectional view showing an example of a protective film laminate (a protective film with a release substrate). FIG. 3 is a cross-sectional view showing an example of the protective film laminate after individual piece processing. FIG. 4 is a plan view showing an example of the protective film laminate after individual piece processing.

[0004] The protective film laminate 109 comprises, for example, a polyimide substrate 106 and a silicone-based curing adhesive layer 107, as shown in Figure 2, and further comprises a release substrate 108 on the side of the silicone-based curing adhesive layer 107 facing the polyimide substrate 106 and the other side. For example, the sheet-like protective film laminate 109 is processed into individual pieces to produce a protective film laminate 111 after individual piece processing, as shown in Figures 3 and 4, in which individual pieces, i.e., individual protective films 110 made of a laminate of the polyimide substrate 106 and the silicone-based curing adhesive layer 107, are arranged at regular intervals along the longitudinal direction of the release substrate 4 (direction of the arrow in Figure 4) on the release substrate 108. Then, for example, using an automated machine, the individual protective films 110 are picked from the protective film laminate 111 after individual piece processing, and the picked individual protective films 110 are supplied to the surface of the cover glass 103.

[0005] Here, when producing the individual protective film pieces 110, if the individual processing is not done properly, the resulting individual protective film pieces 110 may lift away from the release substrate 108 (lifting from the release substrate 108). If this lifting becomes too large, there is a risk that the individual protective film pieces 110 may peel off before they can be picked from the release substrate 108. In addition, at the edges of the individual protective film pieces 110 that have lifted away from the release substrate 108, there may be resin (part of the silicone-based curing adhesive layer 107), for example. If resin is present at the edges of the individual protective film pieces 110, the resin present at the edges of the individual protective film pieces 110 may get caught when picking the individual protective film pieces 110 or when supplying the picked individual protective film pieces 110 to the cover glass 103. As a result, when the individual protective film 110 is peeled off from the cover glass 103 after reflow processing, some of the silicone-based curing adhesive layer 107 may remain on the cover glass 103 (adhesive residue).

[0006] The invention described in Patent Document 1 examines the presence or absence of adhesive residue on the glass surface as an indicator of the peelability of adhesive tape. Patent Document 2 examines the evaluation of adhesive residue in a re-peelable process film. However, Patent Documents 1 and 2 do not describe the presence or absence of adhesive residue when the adhesive tape or re-peelable process film is cut (processed into individual pieces) to the size of a CMOS image sensor (in other words, along the shape of the cover glass). Furthermore, Patent Documents 1 and 2 do not describe evaluations that anticipate potential problems that may occur in actual application equipment, such as the lifting of the adhesive tape from the release substrate after individual piece processing.

[0007] Furthermore, Patent Documents 3 and 4 describe silicone-based adhesive tapes and surface protection films. However, Patent Documents 3 and 4 do not describe whether or not adhesive residue remains when the adhesive tape or surface protection film is processed into individual pieces to the size of a CMOS image sensor, nor do they describe whether the adhesive tape or surface protection film lifts from the release substrate after processing.

[0008] Thus, Patent Documents 1 to 4 do not describe or suggest anything regarding suppressing the lifting of individual protective films from the release substrate, nor do they describe or suggest anything regarding the retention of a portion of the silicone-based curing adhesive layer on the cover glass (adhesive residue) after the individual protective films have been heated at high temperatures. [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] Japanese Patent Publication No. 2010-116532 [Patent Document 2] Japanese Patent Publication No. 2015-147894 [Patent Document 3] Japanese Patent Publication No. 2023-168563 [Patent Document 4] International Publication No. 2013 / 077234 [Overview of the project] [Problems that the invention aims to solve]

[0010] This technology was proposed in view of the conventional situation described above, and provides a protective film, a method for manufacturing a protective film, and a method for manufacturing a CMOS sensor module that can suppress the lifting of individual protective film segments from the release substrate in a protective film laminate after individual segment processing, and also suppress the retention of a portion of the silicone-based curing adhesive layer on the cover glass after the individual protective film segments are heated at high temperatures. [Means for solving the problem]

[0011] The protective film according to this technology comprises a polyimide substrate and a silicone-based curable adhesive layer disposed on the polyimide substrate. The silicone-based curable adhesive layer is obtained by curing an adhesive composition containing curable silicone, a platinum catalyst, and a silane coupling agent. The curable silicone contains a low-tack component (liquid A) and a high-tack component (liquid B). When the low-tack component alone is cured with the platinum catalyst, the adhesive strength to the tin surface of float glass is less than 0.02 N / 2 cm. The high-tack component is... When the strong adhesive component alone is cured with a platinum catalyst, the adhesive strength to the tin surface of float glass is 0.02 to 5.0 N / 2 cm, the mass ratio (solution A:solution B) of the weak adhesive component to the strong adhesive component in the adhesive composition is in the range of 99:1 to 75:25, the silane coupling agent is a reaction product of vinyltriacetoxysilane and glycidoxypropyltrimethoxysilane, and the content of the silane coupling agent in the adhesive composition is greater than 0 parts by mass and 10 parts by mass or less per 100 parts by mass of curable silicone.

[0012] The method for manufacturing a protective film according to this technology comprises the steps of forming a layer made of an adhesive composition on a polyimide substrate and drying the adhesive composition layer to form a silicone-based curable adhesive layer. The adhesive composition is a composition containing a curable silicone, a platinum catalyst, and a silane coupling agent. The curable silicone contains a weakly adhesive component (liquid A) and a strongly adhesive component (liquid B). When the weakly adhesive component alone is cured with the platinum catalyst, the adhesive strength to the tin surface of float glass is less than 0.02 N / 2 cm. The strong adhesive component, when cured alone with a platinum catalyst, has an adhesive strength of 0.02 to 5.0 N / 2 cm to the tin surface of float glass, the mass ratio (A solution:B solution) of the weak adhesive component to the strong adhesive component in the adhesive composition is in the range of 99:1 to 75:25, the silane coupling agent is a reaction product of vinyltriacetoxysilane and glycidoxypropyltrimethoxysilane, and the content of the silane coupling agent per 100 parts by mass of curable silicone in the adhesive composition is greater than 0 parts by mass and 10 parts by mass or less.

[0013] A method for manufacturing a CMOS sensor module according to this technology comprises the steps of: A step of placing a piece-shaped protective film, which is made by processing the aforementioned protective film into individual pieces according to the shape of the cover glass, on the cover glass of an image sensor board comprising a housing member, a CMOS image sensor disposed on one side of the housing member, a cover glass for protecting the CMOS image sensor, and a first electrode formed on the other side of the housing member; B step of connecting the first electrode and a second electrode on another substrate by reflow processing; and C step of removing the piece-shaped protective film after connecting the first electrode and the second electrode. [Effects of the Invention]

[0014] This technology suppresses the lifting of individual protective film segments from the release substrate in a protective film laminate after individual segment processing, and also prevents a portion of the silicone-based curing adhesive layer from remaining on the cover glass after the individual protective film segments are heated at high temperatures. [Brief explanation of the drawing]

[0015] [Figure 1] Figure 1 is a cross-sectional view showing an example of an image sensor board used in a method for manufacturing a CMOS sensor module. [Figure 2] Figure 2 is a cross-sectional view showing an example of a protective film laminate. [Figure 3] Figure 3 is a cross-sectional view showing an example of the protective film after individual piece processing. [Figure 4] Figure 4 is a plan view showing an example of the protective film after individual piece processing. [Figure 5] Figure 5 is a cross-sectional view of a PET film laminate for explaining an example of a method for evaluating the presence or absence of lifting of the individual-piece-shaped protective film for evaluation from the PET film in the PET film laminate. [Figure 6] Figure 6 is a planar photograph showing an example of the PET film laminate when there is lifting of the individual-piece-shaped protective film for evaluation (NG). [Figure 7] Figure 7 is a planar photograph showing an example of float glass when adhesive residue remains after reflow treatment at 260°C for 5 minutes (NG). [Modes for Carrying Out the Invention]

[0016] <Protective Film> A protective film 1 according to the present technology includes, for example, as shown in Figure 2, a polyimide base material 2, and a silicone-based cured pressure-sensitive adhesive layer 3 disposed on the polyimide base material 2. The protective film 1 may further include release base materials 4 on the side of the silicone-based cured pressure-sensitive adhesive layer 3 facing the polyimide base material 2 and on the other surface side. That is, the protective film 1 can also be a protective film laminate 17 further including the release base material 4.

[0017] For example, as shown in Figure 2, the protective film laminate 17 includes a polyimide base material 2 and a silicone-based cured pressure-sensitive adhesive layer 3, and further includes a release base material 4 on the side of the silicone-based cured pressure-sensitive adhesive layer 3 facing the polyimide base material 2 and the other surface side. By subjecting such a protective film laminate 17 to individual piece processing, for example, as shown in Figures 3 and 4, it is possible to produce a protective film laminate 18 after individual piece processing, in which individual pieces composed of a laminate of the polyimide base material 2 and the silicone-based cured pressure-sensitive adhesive layer 3, that is, a plurality of individual piece-shaped protective films 15, are arranged on the release base material 4 at regular intervals along the longitudinal direction of the release base material 4. In the present specification, the individual piece processing includes, in addition to punching processing (punching with a blade, punching with a laser, etc.), for example, forming by a sheet onto which the individual piece portions are transferred.

[0018] As will be described in detail later, for example, in a method for manufacturing a CMOS sensor module, when reflow processing the image sensor board 10 shown in Figure 1, an automated machine is used to pick the individual piece-shaped protective films 15 from the protective film laminate 18 after individual piece processing, and the picked individual piece-shaped protective films 15 are supplied to the surface of the cover glass 13. Then, the individual piece-shaped protective films 15 are peeled off from the surface of the cover glass 13 after the reflow processing.

[0019] Here, the sizes of the CMOS image sensor 12 are diverse. Therefore, it is preferable to perform individual piece processing adapted to the size of the CMOS image sensor 12. In other words, it is preferable to fabricate the individual piece-shaped protective films 15 adapted to the size of the CMOS image sensor 12, for example, the individual piece-shaped protective films 15 conforming to the shape of the cover glass 13. Further, as described above, in the protective film laminate 18 after individual piece processing, it is preferable to be able to suppress the floating of the individual piece-shaped protective films 15 from the release base material 4 (hereinafter also referred to as floating of the individual piece-shaped protective films 15 from the release base material 4 after individual piece processing), and to suppress the phenomenon that a part of the silicone-based cured pressure-sensitive adhesive layer 3 remains on the cover glass 13 after the individual piece-shaped protective films 15 are heated at a high temperature (hereinafter also referred to as adhesive residue after high-temperature heating).

[0020] Based on this perspective, the inventors of this case have found that it is preferable to have the following configuration for the silicone-based curable adhesive layer 3 that constitutes the protective film 1 (piece-shaped protective film 15). First, the silicone-based curable adhesive layer 3 is obtained by curing an adhesive composition (hereinafter also referred to as the adhesive composition) containing curable silicone, a platinum catalyst, and a silane coupling agent.

[0021] Furthermore, the curable silicone contains a slightly adhesive component (liquid A) and a strongly adhesive component (liquid B). When the slightly adhesive component alone is cured with a platinum catalyst, the adhesive strength to the tin surface of float glass (hereinafter also referred to as the "initial adhesive strength of the slightly adhesive component") is less than 0.02 N / 2cm. When the strongly adhesive component alone is cured with a platinum catalyst, the adhesive strength to the tin surface of float glass (hereinafter also referred to as the "initial adhesive strength of the strongly adhesive component") is 0.02 to 5.0 N / 2cm.

[0022] Furthermore, the mass ratio (Solution A:Solution B) of the slightly adhesive component to the strongly adhesive component in the adhesive composition is in the range of 99:1 to 75:25. The silane coupling agent is a reaction product of vinyltriacetoxysilane and glycidoxypropyltrimethoxysilane. In addition, the content of the silane coupling agent in the adhesive composition is greater than 0 parts by mass and 10 parts by mass or less per 100 parts by mass of curable silicone.

[0023] Thus, the protective film 1 is obtained by curing an adhesive composition in which the silicone-based cured adhesive layer 3 contains a specific weak adhesive component and a specific strong adhesive component in a specific ratio, as well as a specific amount of a specific silane coupling agent. With such a protective film 1, for example, in the protective film laminate 18 after individual piece processing, it is possible to suppress the lifting of individual protective film pieces 15 from the release substrate 4, and also to suppress adhesive residue after high-temperature heating.

[0024] Here, suppressing lifting from the release substrate 4 in the protective film laminate 18 after individual piece processing means, for example, that when the protective film laminate 17 is die-cut (cut) to produce the protective film laminate 18 after individual piece processing, there is no space between the silicone-based curing adhesive layer 3 of the individual protective film 15 and the release substrate 4 (e.g., PET film). Specifically, suppressing lifting from the release substrate 4 in the protective film laminate 18 after individual piece processing means that the evaluation result of whether or not there is lifting from the PET film after individual piece processing, as described in the examples below, is good (OK).

[0025] Furthermore, the ability to suppress adhesive residue after high-temperature heating means, for example, that when a piece of protective film 15 attached to a cover glass 13 is heated at a high temperature and then peeled off from the cover glass 13, no portion of the silicone-based curing adhesive layer 3 constituting the piece of protective film 15 remains on the cover glass 13. Specifically, the ability to suppress adhesive residue after high-temperature heating means that the evaluation result for the presence or absence of adhesive residue after heating at 260°C for 5 minutes, as described in the examples below, is good (OK).

[0026] Furthermore, the protective film 1, by having the silicone-based curing adhesive layer 3 configured as described above, can suppress the retention of a portion of the silicone-based curing adhesive layer 3 on the cover glass 13 in the protective film laminate 18 after individual piece processing, before the individual protective film pieces 15 are heated at high temperatures (hereinafter also referred to as pre-high-temperature adhesive residue). Suppression of pre-high-temperature adhesive residue means, for example, that when the individual protective film pieces 15 are peeled off the cover glass after being attached to the cover glass 13, no portion of the silicone-based curing adhesive layer 3 constituting the individual protective film pieces 15 remains on the cover glass 13. Specifically, suppression of pre-high-temperature adhesive residue means that the evaluation result for the presence or absence of adhesive residue after initial adhesive strength measurement, as described in the examples below, is good (OK).

[0027] Furthermore, it is preferable that the protective film 1, when formed into individual protective film pieces 15, has good initial adhesive strength of the silicone-based curing adhesive layer 3 to the cover glass 13. The initial adhesive strength of the silicone-based curing adhesive layer 3 to the cover glass 13 can be, for example, 0.1 N / 2 cm or more and less than 0.7 N / 2 cm. If the initial adhesive strength is too high (for example, 0.7 N / 2 cm or more), for example, when the protective film 1 is peeled off from the cover glass 13 immediately after use, some of the silicone-based curing adhesive layer 3 (adhesive) tends to remain on the cover glass 13. Also, if the initial adhesive strength is too low (for example, less than 0.1 N / 2 cm), the protective film 1 may easily peel off from the cover glass 13 and may not function adequately as a protective film 1. The initial adhesive strength of the silicone-based curing adhesive layer 3 to the cover glass 13 refers to the value measured by the method described in the examples below.

[0028] The protective film 1 comprises at least a polyimide substrate 2 and a silicone-based curing adhesive layer 3. The protective film 1 may also have a configuration in which a release substrate 4 is further provided on the side of the silicone-based curing adhesive layer 3 that is not on the side of the polyimide substrate 2, as shown in Figure 2, i.e., a protective film laminate 17. An example of the configuration of the protective film laminate 17 will be described below.

[0029] <Polyimide base material> The polyimide substrate 2 may, for example, have polyimide as its main component and may contain other components besides polyimide. For example, the polyimide substrate 2 is made of polyimide and is a polyimide film in film form.

[0030] The thickness of the polyimide substrate 2 can be, for example, 10 μm or more, 20 μm or more, 30 μm or more, 40 μm or more, or 50 μm or more. Alternatively, the thickness of the polyimide substrate 2 can be, for example, 200 μm or less, 150 μm or less, 100 μm or less, 90 μm or less, 80 μm or less, 70 μm or less, or 60 μm or less. As an example, the thickness of the polyimide substrate 2 can be 10 to 90 μm, 20 to 80 μm, 30 to 70 μm, or 40 to 60 μm.

[0031] The polyimide substrate 2 may be a single layer or a multilayer structure consisting of two or more layers. When the polyimide substrate 2 is a multilayer structure, it is preferable that the sum of the thicknesses of each layer falls within the range described above.

[0032] <Silicone-based curing adhesive layer> As shown in Figure 2, for example, one surface of the silicone-based curing adhesive layer 3 is in contact with one surface of the polyimide substrate 2, and the other surface is in contact with the release substrate 4.

[0033] The silicone-based curable adhesive layer 3 is obtained by curing an adhesive composition containing curable silicone, a platinum catalyst, and a silane coupling agent.

[0034] <Curing Silicone> Curable silicones generally fall into two categories: addition-type and peroxide-type. Addition-type curable silicones can be cured at low temperatures and in a short time using a platinum catalyst (for example, 100-130°C for 1 minute or more), and their adhesion can be adjusted from very slightly sticky to very sticky, as will be detailed later. In contrast, peroxide-type curable silicones have a high curing temperature (for example, 150-180°C), and it is more difficult to adjust their adhesion from very slightly sticky to very sticky compared to addition-type curable silicones. Therefore, in the protective film according to this technology, it is preferable that the curable silicone contains a silicone compound having an addition reaction group (addition-type), a silicone resin, and a hydrosilane compound.

[0035] First, silicone compounds having addition groups will be described. Silicone compounds having addition groups are, for example, organopolysiloxanes and their partial condensates that have addition groups. Organopolysiloxanes are, for example, monoorganopolysiloxanes, diorganopolysiloxanes, or triorganopolysiloxanes. The organo group of the organopolysiloxane is, for example, a hydrocarbon group having 1 to 8 carbon atoms, may also be a hydrocarbon group having 1 to 4 carbon atoms, or a linear or branched alkyl group having 1 to 4 carbon atoms. The organo group is, for example, a methyl group. The organo group may be partially substituted with a hydroxyl group. The addition group may be, for example, a monovalent organic group containing an alkenyl group, a vinyl group, or an allyl group, or simply a vinyl group. Silicone compounds having addition groups only need to have an addition group at at least one end, or may have addition groups at both ends.

[0036] Specific examples of silicone compounds having addition groups include vinyldimethylpolysiloxane, vinyldiethylpolysiloxane, vinylisopropylpolysiloxane, and vinylphenylmethylsiloxane. The content of the addition group in a silicone compound having an addition group can be, for example, 0.0005 to 0.5 moles per 100g of the silicone compound.

[0037] The weight-average molecular weight of a silicone compound having an addition reaction group can be, for example, 100,000 to 1,000,000.

[0038] The content of the silicone compound having an addition group in the adhesive composition can be, for example, 20 to 80% by mass. The silicone compound having an addition group may be used alone or in combination of two or more. When two or more silicone compounds having an addition group are used in combination, it is preferable that their total amount satisfies the above-mentioned content.

[0039] Next, we will explain silicone resin. Silicone resin is, for example, Q unit (SiO2) and M unit (R3SiO2). 1 / 2 ) and D units (R2SiO) and T units (R1SiO) 3 / 2 ) and a partial condensate thereof having at least one unit selected from ). R1 ​​to R3 in each unit may independently be, for example, a hydrocarbon group having 1 to 8 carbon atoms, a hydrocarbon group having 1 to 4 carbon atoms, or a linear or branched alkyl group having 1 to 4 carbon atoms. A specific example of R1 to R3 is a methyl group. R1 to R3 may be partially substituted with hydroxyl groups. It is preferable that the silicone resin does not have addition reaction groups. The silicone resin may be, for example, a so-called MQ resin composed of M units and Q units.

[0040] The weight-average molecular weight of the silicone resin may be, for example, 1,000 to 10,000, or 3,000 to 8,000.

[0041] The content of silicone resin in the adhesive composition can be, for example, 20 to 80% by mass. One type of silicone resin may be used alone, or two or more types may be used in combination. When two or more types of silicone resin are used in combination, it is preferable that their total amount satisfies the above-mentioned content.

[0042] Next, hydrosilane compounds will be described. Hydrosilane compounds are components that have a Si-H group and react with the addition reaction group in a silicone compound having an addition reaction group to form a crosslinked structure. Examples of hydrosilane compounds are hydrogen organopolysiloxanes and their partial condensates. Examples of hydrogen organopolysiloxanes include hydrogen monoorganopolysiloxane, hydrogen diorganopolysiloxane, and copolymers of hydrogen monomethylsiloxane and hydrogen dimethylsiloxane. The organo group in the hydrosilane compound is, for example, synonymous with the organo group in the silicone compound having the addition reaction group described above, and the preferred range is also the same.

[0043] The weight-average molecular weight of the hydrosilane compound may be, for example, 100 to 10,000, or 100 to 1,000.

[0044] The content of the hydrosilane compound can be such that, for example, the molar ratio of Si-H groups in the hydrosilane compound to the addition reaction groups in the silicone compound having the addition reaction groups is 0.5 to 20. The hydrosilane compound may be used alone or in combination of two or more types. When two or more hydrosilane compounds are used in combination, it is preferable that their total amount satisfies the above-mentioned content.

[0045] The curable silicone in protective film 1 contains a slightly adhesive component (liquid A) and a strongly adhesive component (liquid B).

[0046] A low-tack component refers to a low-tack component whose initial adhesive strength is less than 0.02 N / 2 cm. Furthermore, the initial adhesive strength of a low-tack component may be greater than 0 N / 2 cm, and may be 0.001 N / 2 cm or more, 0.005 N / 2 cm or more, or 0.001 N / 2 cm or more. A low-tack component may be used alone or in combination of two or more types. The initial adhesive strength of a low-tack component can be measured by the method described in the examples below.

[0047] A strong adhesive component refers to a strong adhesive component whose initial adhesive strength is 0.02 N / 2cm or more and 5.0 N / 2cm or less, but may also be 0.1 N / 2cm or more, 0.5 N / 2cm or more, 1.0 N / 2cm or more, 2.0 N / 2cm or more, 3.0 N / 2cm or more, 3.5 N / 2cm or more, or 4.0 N / 2cm or more. A strong adhesive component may be used alone or in combination of two or more types. The initial adhesive strength of the strong adhesive component can be measured by the method described in the examples below.

[0048] In the adhesive composition, the mass ratio (A liquid:B liquid) of the mildly tacky component to the strongly tacky component is in the range of 99:1 to 75:25. By configuring the adhesive composition in this way, the silicone-based cured adhesive layer 3 does not become too soft, the cutability after processing the protective film laminate 17 into individual pieces is good, and the adhesion of the silicone-based cured adhesive layer 3 to the polyimide layer 2 is also good, making it difficult for the resin to detach from the polyimide layer 2. Therefore, in the protective film laminate 18 after processing, the lifting of the individual protective film pieces 15 from the release substrate 4 can be suppressed. In addition, by not having too little mildly tacky component in the adhesive composition, or in other words, not having too much strongly tacky component, the silicone-based cured adhesive layer 3 does not become too hard, and adhesive residue after high-temperature heating can be suppressed.

[0049] <Platinum catalyst> Platinum catalysts are catalysts containing platinum group elements (platinum-based catalysts) and are components for promoting the curing reaction of curable silicones. The platinum group elements contained in the platinum catalyst remain in the silicone-based curing adhesive layer (cured product of curable silicone). The content of platinum catalysts may be, for example, more than 0 parts by mass per 100 parts by mass of curable silicone, and may be 0.1 parts by mass or more, 0.5 parts by mass or more, or 0.8 parts by mass or more. Alternatively, the content of platinum catalysts may be 10 parts by mass or less per 100 parts by mass of curable silicone, and may be 8 parts by mass or less, 5 parts by mass or less, 3 parts by mass or less, 2 parts by mass or less, or 1 part by mass or less. Platinum catalysts may be used alone or in combination of two or more types.

[0050] <Silane coupling agent> Silane coupling agents are reaction products of vinyltriacetoxysilane and glycidoxypropyltrimethoxysilane (hereinafter also referred to as specific silane coupling agents). For example, vinyltriacetoxysilane and glycidoxypropyltrimethoxysilane are presumed to react as follows, but are not limited to this example. First, the alkoxy group of glycidoxypropyltrimethoxysilane is changed to a silanol group (Si-OH) by hydrolysis (silanolization). Then, the silanol group condenses (dehydration condensation) to form a Si-O-Si bond (siloxaneization). In this dehydration condensation, water is produced as a byproduct. Furthermore, the triacetoxy group of vinyltriacetoxysilane reacts with the epoxy group of glycidoxypropyltrimethoxysilane, causing the epoxy group to open its ring and a hydroxyl group to be generated. Then, the generated hydroxyl group reacts with the triacetoxy group of vinyltriacetoxysilane.

[0051] Preferably, the specific silane coupling agent has vinyl and glycidyl groups. The presence of vinyl groups in the specific silane coupling agent makes it easier to incorporate into the reaction of the curable silicone. Furthermore, the presence of glycidyl groups in the specific silane coupling agent makes it easier to react with functional groups such as amine groups remaining at the ends of the polyimide substrate 2 (for example, the surface of the polyimide substrate 2 that is in contact with the silicone-based curable adhesive layer 3). In this way, by using a specific silane coupling agent, the adhesion between the silicone-based curable adhesive layer 3 and the polyimide substrate 2 can be further improved. The number-average molecular weight (Mn) of the specific silane coupling agent can be, for example, in the range of 197 to 667. The weight-average molecular weight (Mw) of the specific silane coupling agent can be, for example, in the range of 201 to 793. The specific silane coupling agent may be, for example, a mixture of monomers, dimers, and tetramers of vinyltriacetoxysilane and glycidoxypropyltrimethoxysilane.

[0052] Certain silane coupling agents are preferably in a dehydration-condensed, crosslinked state. In other words, certain silane coupling agents are preferably substantially water-free. By being substantially water-free, certain silane coupling agents can suppress curing inhibition of the curable silicone.

[0053] Here, instead of using a specific silane coupling agent, it is conceivable to use, for example, a silane coupling agent having only vinyl groups as functional groups in combination with a silane coupling agent having only glycidyl groups as functional groups. However, if a silane coupling agent having only vinyl groups as functional groups and a silane coupling agent having only glycidyl groups as functional groups are used in combination, water will be required or released in the reaction pathway, which is thought to cause curing inhibition of the curable silicone, resulting in adhesive residue after high-temperature heating.

[0054] The content of a specific silane coupling agent may be, for example, more than 0 parts by mass per 100 parts by mass of curable silicone, and may be 0.1 parts by mass or more, 0.5 parts by mass or more, or 0.8 parts by mass or more. Alternatively, the content of a specific silane coupling agent may be 10 parts by mass or less per 100 parts by mass of curable silicone, and may be 8 parts by mass or less, 5 parts by mass or less, 3 parts by mass or less, 2 parts by mass or less, or 1 part by mass or less. By setting the content of the specific silane coupling agent within these ranges, adhesive residue after high-temperature heating can be suppressed. A specific silane coupling agent may be used alone, or two or more may be used in combination. When two or more specific silane coupling agents are used in combination, it is preferable that their total content satisfies the above-mentioned range.

[0055] <Other ingredients> The adhesive composition may further contain other components besides those described above, as long as they do not impair the effects of this technology. For example, the adhesive composition may further contain an organic solvent. Alternatively, the adhesive composition may contain a curable silicone, a platinum catalyst, and a specific silane coupling agent, and may substantially not contain any other components.

[0056] The thickness of the silicone-based curing adhesive layer 3 can be, for example, 1 μm or more, 2 μm or more, 3 μm or more, 4 μm or more, or 5 μm or more. Alternatively, the thickness of the silicone-based curing adhesive layer 3 can be, for example, 30 μm or less, 25 μm or less, 20 μm or less, or 15 μm or less. As an example, the thickness of the silicone-based curing adhesive layer 3 can be 1 to 30 μm, 1 to 25 μm, 1 to 20 μm, or 5 to 15 μm.

[0057] The silicone-based curing adhesive layer 3 may be a single layer or a multi-layered layer consisting of two or more layers. When the silicone-based curing adhesive layer 3 is a multi-layered layer, it is preferable that the sum of the thicknesses of each layer falls within the range described above.

[0058] <Release agent> The release substrate 4 is for protecting the silicone-based curing adhesive layer 3 in the protective film 1 (piece-shaped protective film 15). The release substrate 4 is obtained by removing the surface of a substrate such as PET (Poly Ethylene Terephthalate), OPP (Oriented Polypropylene), PMP (Poly-4-methylpentene-1), or PTFE (Polytetrafluoroethylene) with a release agent such as silicone resin. For example, a release-treated PET film can be used as the release substrate 4.

[0059] The thickness of the release substrate 4 can be, for example, 10 μm or more, 20 μm or more, 30 μm or more, 40 μm or more, or 50 μm or more. Alternatively, the thickness of the release substrate 4 can be, for example, 200 μm or less, 150 μm or less, 100 μm or less, 90 μm or less, 80 μm or less, 70 μm or less, or 60 μm or less. As an example, the thickness of the release substrate 4 can be 10 to 90 μm, 20 to 80 μm, 30 to 70 μm, or 40 to 60 μm.

[0060] The release substrate 4 may be a single layer or a multi-layer structure consisting of two or more layers. If the release substrate 4 is a multi-layer structure, it is preferable that the sum of the thicknesses of each layer falls within the range described above.

[0061] The protective film 1 may consist of the polyimide substrate 2, the silicone-based curing adhesive layer 3, and the release substrate 4 as described above, or it may consist of the polyimide substrate 2 and the silicone-based curing adhesive layer 3. Furthermore, the protective film 1 may further include other layers as long as they do not impair the effects of this technology.

[0062] <Method for manufacturing protective film> Next, a method for manufacturing the protective film 1 will be described. The method for manufacturing the protective film 1 includes, for example, step a, forming a layer made of the above-described adhesive composition (hereinafter also referred to as the adhesive composition layer) on a polyimide substrate 2, and step b, forming a silicone-based cured adhesive layer 3 obtained by drying the adhesive composition layer. The method for manufacturing the protective film 1 may further include step c, laminating a release substrate 4 to the polyimide substrate 2 side and the other side of the silicone-based cured adhesive layer 3.

[0063] In step a, for example, an adhesive composition can be applied to a polyimide substrate 2 to form an adhesive composition layer. The thickness of the adhesive composition layer can be set, for example, so that the thickness after drying, i.e., the thickness of the silicone-based cured adhesive layer 3, is 1 to 50 μm, or it may be set to 1 to 30 μm, or it may be set to 1 to 20 μm.

[0064] In step b, the adhesive composition layer is dried by heating it using a heating means (e.g., an oven). This results in a laminate in which a silicone-based curing adhesive layer 3 is formed on the polyimide substrate 2.

[0065] The temperature at which the adhesive composition layer is heated can be, for example, a temperature at which the organic solvent in the adhesive composition layer can evaporate, and may be 80°C or higher, 100°C or higher, 150°C or higher, or in the range of 70 to 170°C. The heating time for the adhesive composition layer can be, for example, 1 to 30 minutes. The method for heating the adhesive composition layer may be a two-stage heating method in which the layer is heated at a first temperature for a predetermined time, and then heated at a second temperature higher than the first temperature for a predetermined time. The first temperature can be, for example, in the range of 70 to 100°C. The second temperature can be, for example, in the range of 130 to 170°C. By employing such a two-stage heating method, for example, if the adhesive composition layer contains an organic solvent, the boiling of the organic solvent in the adhesive composition layer during heating can be more effectively suppressed, and the surface of the resulting silicone-based cured adhesive layer 3 can be made smoother.

[0066] In step c, a release substrate 4 is laminated to the side of the silicone-based curing adhesive layer 3 that is on the polyimide substrate 2 side and the other side. Through steps a to c, a protective film laminate 17 is obtained, for example as shown in Figure 2, comprising the polyimide substrate 2, the silicone-based curing adhesive layer 3, and the release substrate 4 in this order. By processing the protective film laminate 17 into individual pieces, individual protective films 15 are obtained.

[0067] The method for producing the protective film 1 may further include other steps than the steps a to c described above within a range that does not impair the effects of the present technology, or may consist solely of the steps a to c described above.

[0068] <Method for manufacturing CMOS sensor module> Next, a method for manufacturing a CMOS sensor module using the protective film 1 (the sheet-shaped protective film 15) will be described. In the method for manufacturing a CMOS sensor module, for example, as shown in Figure 1, an image sensor board 10 including a housing member 11, a CMOS image sensor 12, a cover glass 13, and a first electrode 14 is prepared. In the image sensor board 10, the CMOS image sensor 12 is, for example, disposed on the housing member 11. The cover glass 13 is, for example, disposed on the CMOS image sensor 12 to protect the CMOS image sensor 12. The first electrode 14 is, for example, formed on the surface side of the housing member 11 opposite to the side where the CMOS image sensor 12 is disposed, and is intended to be connected to a second electrode (not shown) of another substrate by a reflow process.

[0069] The method for manufacturing a CMOS sensor module includes, for example, Step A of disposing the sheet-shaped protective film 15 on the cover glass 13 of the image sensor board 10, Step B of connecting the first electrode 14 to the second electrode of another substrate, and Step C of removing the sheet-shaped protective film 15 on the cover glass 13.

[0070] In step A, for example, individual protective films 15 are placed on the cover glass 13 of the image sensor board 10. The individual protective films 15 are made by processing a laminate 16 of a polyimide substrate 2 and a silicone-based curing adhesive layer 3 that constitutes the protective film 1 into individual pieces that conform to the shape (surface shape) of the cover glass 13. In step A, the silicone-based curing adhesive layer 3 side of the individual protective film 16 is attached to the surface of the cover glass 13 that is not the side on which the CMOS image sensor 12 is placed. This protects the surface of the CMOS image sensor 12 when connecting the first electrode 14 to the second electrode on the other substrate in step B.

[0071] Step A may further include, for example, Step A1, which prepares a protective film laminate 17 by laminating a tape-shaped release substrate 4 to the silicone-based curing adhesive layer 3 side of a tape-shaped protective film 1, and Step A2, which prepares a protective film laminate 18 after individual piece processing by die-cutting the protective film laminate 17.

[0072] In step A1, for example, a tape-shaped protective film laminate 17 is prepared. The tape-shaped protective film laminate 17 can be, for example, a film winding body wound around a core.

[0073] In step A2, for example, the protective film laminate 17 is punched using a punching machine (press machine) to prepare a protective film laminate 18 after individual processing, in which multiple individual protective film pieces 15 are arranged on a release substrate 4. After punching the protective film laminate 17, for example, the remaining part (the remaining part after punching) other than the individual protective film pieces 15 is peeled off from the laminate 16 of the polyimide substrate 2 and the silicone-based curing adhesive layer 3 that constitute the protective film laminate 17, thereby obtaining the protective film laminate 18 after individual processing. The protective film laminate 18 after individual processing can be, for example, in the form of a tape, or it can be a film winding body wound on a core. The individual protective film pieces 15 can be shaped to conform to the shape of the cover glass 13 on the image sensor board 10, for example, they can be rectangular in plan view. If the individual protective film pieces 15 are rectangular, for example, each side can be 1 to 10 mm. Furthermore, the individual protective film pieces 15 can be rectangular in shape, for example as shown in Figure 4, with one opposite side being the shorter side and the other opposite side being the longer side, along the direction of travel (direction D in Figure 4) in which the protective film laminate 18 after individual processing is fed out, and the edges can have protrusions projecting in the direction of the longer side.

[0074] The housing member 11 constituting the image sensor board 10 is, for example, a member on which a CMOS image sensor 12 is mounted. The housing member 11 has, for example, wiring that transmits signals from the CMOS image sensor 12. The CMOS image sensor 12 is connected to, for example, a pad formed on the housing member 11. This pad is connected to, for example, the wiring of the housing member 11. The cover glass 13 is for protecting the surface of the CMOS image sensor 12. The first electrode 14 is for connecting to a second electrode of another member and can be made of, for example, solder.

[0075] In step B, for example, a reflow process is used to connect the first electrode 14 on the image sensor board 10 to the electrode (second electrode) of another component. Below, an example of step B when solder is used as the first electrode 14 will be described. In step B, for example, a reflow oven set to a temperature above the melting point of the solder used as the first electrode 14 is used to join the first electrode 14 to the second electrode of the other component. Examples of reflow ovens include atmospheric pressure reflow, vacuum reflow, atmospheric pressure oven, and autoclave (pressure oven). Since a reflow oven can heat-bond without mechanical pressure and without load, damage to the components of the image sensor board 10 and other components can be suppressed. Here, "no load" refers to a state without mechanical pressure. The peak temperature (maximum temperature reached) in a reflow oven can be, for example, 170°C or higher, 180°C or higher, 200°C or higher, 300°C or lower, 290°C or lower, 280°C or lower, or 270°C or lower.

[0076] In step C, after connecting the first electrode 14 to the second electrode of another component, the individual protective film 15 on the cover glass 13 is removed.

[0077] Thus, in the manufacturing method of the CMOS sensor module, in step A, the individual protective film 1 described above is processed into individual pieces to be placed on the cover glass 13. This suppresses the lifting of the individual protective film pieces 15 from the release substrate 4 in the protective film laminate 18 after processing. Furthermore, because the lifting of the individual protective film pieces 15 from the release substrate 4 is suppressed in the protective film laminate 18 after processing, adhesive residue after high-temperature heating can be suppressed when removing the individual protective film pieces 15 placed on the cover glass 13 in step C.

[0078] The manufacturing method for the CMOS sensor module may further include other steps besides steps A to C described above, as long as they do not impair the effectiveness of this technology, or it may consist only of steps A to C described above. [Examples]

[0079] The following describes some embodiments of this technology. However, this technology is not limited to these embodiments.

[0080] <Example 1> A 50 μm thick polyimide film (Kapton 200H, manufactured by Toray DuPont) was prepared as the polyimide substrate. An adhesive composition was also prepared by mixing a low-tack component (KR3704, manufactured by Shin-Etsu Silicone Co., Ltd.), a high-tack component (KR3700, manufactured by Shin-Etsu Silicone Co., Ltd.), a platinum catalyst (CAT-PL-50T, manufactured by Shin-Etsu Silicone Co., Ltd.), and a silane coupling agent (SD7200, manufactured by Dow-Toray) in the amounts (parts by mass) shown in Table 1. The silane coupling agent (SD7200) is a reaction product of vinyltriacetoxysilane and glycidoxypropyltrimethoxysilane, and corresponds to the specific silane coupling agent described above.

[0081] The obtained adhesive composition was applied onto a polyimide film. The amount of adhesive composition applied was such that the thickness after drying was 10 μm. This resulted in obtaining a first laminate in which the adhesive composition was applied to the polyimide film.

[0082] The first laminate was heated in an oven set to 80°C for 5 minutes, and then heated again in an oven set to 160°C for 5 minutes to dry the adhesive composition. This resulted in a second laminate in which a 10 μm thick silicone-based cured adhesive layer was formed on the polyimide film. The second laminate corresponds to the protective film 1 described above.

[0083] A 50 μm thick PET film was laminated to the side of the second laminate where the silicone-based curing adhesive layer was located, opposite to the polyimide film. This resulted in a third laminate in which the polyimide film, the silicone-based curing adhesive layer, and the PET film were laminated in that order. The third laminate corresponds to the protective film laminate 17 described above.

[0084] A die was created that could cut out pieces of 5mm x 5mm using a sealing blade. This die was connected to a press machine, and the third laminate was cut out using the press machine. As a result, a PET film laminate was obtained in which multiple individual protective films (5mm x 5mm) for evaluation, each consisting of a polyimide film and a silicone-based curing adhesive layer, were arranged at regular intervals on the PET film. The individual protective films for evaluation correspond to the individual protective films 15 described above. The PET film laminate corresponds to the protective film laminate 18 after the individual processing described above.

[0085] <Example 2> In Example 2, individual protective films for evaluation were obtained in the same manner as in Example 1, except that the mass ratio of the weakly adhesive component to the strongly adhesive component in the adhesive composition was changed to the values ​​shown in Table 1.

[0086] <Example 3> In Example 3, individual protective films for evaluation were obtained in the same manner as in Example 1, except that the content of the silane coupling agent in the adhesive composition was changed to the values ​​shown in Table 1.

[0087] <Comparative Example 1> In Comparative Example 1, individual protective films for evaluation were obtained in the same manner as in Example 1, except that the mass ratio of the slightly tacky component to the strongly tacky component in the adhesive composition was changed to the values ​​shown in Table 1, that is, only the slightly tacky component was used as the curable silicone.

[0088] <Comparative Example 2> In Comparative Example 2, the adhesive composition contained only a slightly adhesive component and a platinum catalyst, and the amounts of the slightly adhesive component and the platinum catalyst were changed to the values ​​shown in Table 1. Otherwise, individual protective films for evaluation were obtained in the same manner as in Example 1.

[0089] <Comparative Example 3> In Comparative Example 3, the adhesive composition contained only a strong adhesive component and a platinum catalyst, and the amounts of the strong adhesive component and platinum catalyst were changed to the values ​​shown in Table 1. Otherwise, individual protective films for evaluation were obtained in the same manner as in Example 1.

[0090] <Comparative Example 4> In Comparative Example 4, individual protective films for evaluation were obtained in the same manner as in Example 1, except that the mass ratio of the slightly adhesive component to the strongly adhesive component in the adhesive composition was changed to the values ​​shown in Table 1.

[0091] <Comparative Example 5> In Comparative Example 5, individual protective films for evaluation were obtained in the same manner as in Example 2, except that the content of the silane coupling agent in the adhesive composition was changed to the values ​​shown in Table 1.

[0092] <Comparative Example 6> In Comparative Example 6, individual protective films for evaluation were obtained in the same manner as in Example 1, except that the mass ratio of the slightly tacky component to the strongly tacky component in the adhesive composition was changed to the values ​​shown in Table 1, that is, only the slightly tacky component was used as the curable silicone, and the platinum catalyst was not included in the adhesive composition.

[0093] <Comparative Example 7> In Comparative Example 7, individual protective films for evaluation were obtained in the same manner as in Example 1, except that the adhesive composition did not contain a silane coupling agent.

[0094] <Comparative Example 8> In Comparative Example 8, individual protective films for evaluation were obtained in the same manner as in Example 1, except that the silane coupling agent was changed to a silane coupling agent containing only glycidyl groups (KBM-403, manufactured by Shin-Etsu Silicone Co., Ltd.).

[0095] <Comparative Example 9> In Comparative Example 9, individual protective films for evaluation were obtained in the same manner as in Example 1, except that the silane coupling agent was changed to a silane coupling agent containing only vinyl groups (KBM-1003, manufactured by Shin-Etsu Silicone Co., Ltd.).

[0096] The individual protective films obtained in the examples and comparative examples were evaluated as follows.

[0097] <Presence or absence of lifting from the PET film after die-cutting> Figures 5(A) and 5(B) are cross-sectional views of a PET film laminate illustrating an example of a method for evaluating whether or not individual protective film pieces for evaluation are lifting from the PET film in the PET film laminate. Figure 6(A) is a plan view showing an example of a PET film laminate where there is lifting of the individual protective film pieces for evaluation (NG), and Figure 6(B) is a magnified view of region P in Figure 6(A).

[0098] The presence or absence of lifting of the evaluation-type protective film 20 from the PET film 23 in the PET film laminate 21 was evaluated using a stereomicroscope (Olympus SZX16, 20x magnification) from the surface of the evaluation-type protective film 20 (the polyimide film 24 side of the evaluation-type protective film 20) as shown in Figure 5(A), and from the back surface of the evaluation-type protective film 20 (the PET film 23 side) as shown in Figure 5(B). The results are shown in Tables 1 and 2. The results shown in Tables 1 and 2 are the results of measurements performed using n=5 samples (individual protective film 20) for each example and comparative example. In Tables 1 and 2, "○" indicates that there was no lifting of the evaluation-type protective film 20 from the PET film 23 in all samples (OK). Also, in Tables 1 and 2, "×" indicates that there was lifting of the evaluation-type protective film 20 from the PET film 23 in at least one sample (NG). If there is any lifting of the individual protective film 20 used for evaluation, a space 22 exists between the silicone-based curing adhesive layer 25 of the individual protective film 20 used for evaluation and the PET film 23, as shown in Figures 6(A) and (B).

[0099] <Initial adhesive strength> Using a fully automatic CMOS protective film application machine (CF-Y540, Cogitate), the silicone-based cured adhesive layer side of the individual protective films 20 used for evaluation in Examples 1-3 and Comparative Examples 4-7 was placed on the tin surface of float glass (2 mm thick, 50 mm x 100 mm) conforming to JIS 3202, and the initial adhesive strength (180° adhesive strength) of the silicone-based cured adhesive layer to the tin surface of the float glass was evaluated. In Comparative Examples 1-3, the initial adhesive strength of the silicone-based cured adhesive layer to the tin surface of the float glass was evaluated using the same method as in Examples 1-3 and Comparative Examples 4-7 for the third laminate (sheet-like laminate before die-cutting) described above. The initial adhesive strength was measured using an RTI-1225 manufactured by A&D Company at 180° and a speed of 300 mm / min. The results are shown in Tables 1 and 2. The results shown in Tables 1 and 2 are the results obtained using n=5 samples for each example and comparative example.

[0100] <Presence or absence of adhesive residue after initial adhesive strength measurement> The presence or absence of adhesive residue on the individual protective film pieces 20 used for evaluation after measuring the initial adhesive strength was evaluated. The presence or absence of adhesive residue on the individual protective film pieces 20 used for evaluation was confirmed using a stereomicroscope (Olympus SZX16, 20x magnification) to check whether any adhesive residue remained on the float glass after peeling the individual protective film pieces 20 used for evaluation from the float glass after measuring the initial adhesive strength, that is, whether a portion of the silicone-based curing adhesive layer 3 constituting the individual protective film pieces 20 used for evaluation remained on the float glass. The results are shown in Tables 1 and 2. The results shown in Tables 1 and 2 are the results obtained by measuring n=5 samples (individual protective film pieces 20) for each example and comparative example. In Tables 1 and 2, "○" indicates that there was no adhesive residue on the float glass after measuring the initial adhesive strength for all samples (OK). Also, in Tables 1 and 2, "×" indicates that there was adhesive residue on the float glass after measuring the initial adhesive strength for at least one or more samples (NG).

[0101] <Presence or absence of adhesive residue after heating at 260°C for 5 minutes> Using a fully automatic CMOS protective film application machine (CF-Y540, Cogitate), individual protective films 20 for evaluation were placed on the tin surface of a 2mm thick float glass (50mm x 100mm) conforming to JIS 3202, and the presence or absence of adhesive residue after reflow treatment at 260°C for 5 minutes was evaluated. Figure 7 is a plan view photograph showing an example of float glass where adhesive residue was present (NG) after reflow treatment at 260°C for 5 minutes. Specifically, the laminate of the individual protective films 20 for evaluation and the float glass 26 was reflow treated at 260°C for 5 minutes, then left to stand at room temperature for 30 minutes. The individual protective films 20 for evaluation were then peeled off the float glass 26, and the presence or absence of adhesive residue on the float glass 26, i.e., whether a portion 27 of the silicone-based curing adhesive layer 3 remained on the float glass 26, was checked using a stereomicroscope (Olympus SZX16, 20x magnification). The results are shown in Tables 1 and 2. The results shown in Tables 1 and 2 are from measurements performed using n=5 samples for each example and comparative example. In Tables 1 and 2, "○" indicates that there was no adhesive residue on the float glass 26 for all samples (OK). In Tables 1 and 2, "×" indicates that there was adhesive residue on the float glass 26 for at least one sample (NG).

[0102] [Table 1]

[0103] [Table 2]

[0104] The individual protective films 20 obtained for evaluation in Examples 1-3 showed no lifting from the PET film 23 and no adhesive residue after heating at 260°C for 5 minutes. Furthermore, the individual protective films 20 obtained for evaluation in Examples 1-3 showed no adhesive residue after initial adhesive strength measurement and demonstrated good initial adhesive strength.

[0105] In contrast, the individual protective films used for evaluation obtained in Comparative Examples 1 to 9 were found to either lift away from the PET film 23 or have adhesive residue after heating at 260°C for 5 minutes.

[0106] In Comparative Example 1, the individual protective film pieces used for evaluation likely lifted from the PET film 23 because the silicone-based curing adhesive layer did not contain a strong adhesive component.

[0107] In Comparative Example 2, the individual protective film pieces obtained for evaluation likely experienced lifting from the PET film 23 because the silicone-based curing adhesive layer did not contain a strong adhesive component. Furthermore, in Comparative Example 2, the individual protective film pieces obtained for evaluation likely experienced adhesive residue (adhesive residue after initial adhesive strength measurement and adhesive residue after heating at 260°C for 5 minutes) because the silicone-based curing adhesive layer did not contain a silane coupling agent in addition to a strong adhesive component.

[0108] In Comparative Example 3, the individual protective films used for evaluation were likely to have adhesive residue (adhesive residue after initial adhesive strength measurement and adhesive residue after heating at 260°C for 5 minutes) because the silicone-based curing adhesive layer did not contain a weak adhesive component or a silane coupling agent.

[0109] In Comparative Example 4, the individual protective films used for evaluation had too high a ratio of strong adhesive component in the silicone-based curing adhesive layer. In other words, the resin (silicone-based curing adhesive layer) was too soft. As a result, when the films were die-cut using a press, some of the resin was not cut properly, leading to adhesive residue (adhesive residue after initial adhesive strength measurement and adhesive residue after heating at 260°C for 5 minutes).

[0110] In Comparative Example 5, the individual protective film pieces used for evaluation had too much silane coupling agent in the silicone-based curing adhesive layer, which resulted in excessive adhesion to the float glass and left adhesive residue after heating at 260°C for 5 minutes.

[0111] In Comparative Example 6, the individual protective films used for evaluation remained uncured because the silicone-based curing adhesive layer did not contain a platinum catalyst. This likely resulted in adhesive residue (residue after initial adhesive strength measurement and after heating at 260°C for 5 minutes).

[0112] In Comparative Example 7, the individual protective film pieces used for evaluation were found to have a silicone-based curing adhesive layer that did not contain a silane coupling agent. As a result, after heating at 260°C for 5 minutes, the adhesion force to the polyimide film was weaker than the adhesion force to the float glass, which likely caused adhesive residue to form on the float glass.

[0113] In Comparative Example 8, the individual protective film pieces used for evaluation were not properly incorporated into the curing system of the curable silicone. This was because a glycidyl group-containing silane coupling agent was used instead of a reaction product of vinyltriacetoxysilane and glycidoxypropyltrimethoxysilane. As a result, the silane coupling agent was not properly incorporated into the curing system of the curable silicone, and the adhesion of the silicone-based curable adhesive layer to the polyimide film was insufficient. Consequently, the film peeled off from the polyimide film side, resulting in adhesive residue after heating at 260°C for 5 minutes.

[0114] In Comparative Example 9, the individual protective films used for evaluation were produced using a vinyl group-containing silane coupling agent instead of a reaction product of vinyltriacetoxysilane and glycidoxypropyltrimethoxysilane. As a result, although the silane coupling agent was incorporated into the curing system of the curable silicone, the adhesion of the silicone-based curing adhesive layer to the polyimide film was insufficient, causing it to peel off from the polyimide film side, resulting in adhesive residue after heating at 260°C for 5 minutes. [Explanation of symbols]

[0115] 1. Protective film, 2. Polyimide substrate, 3. Silicone-based curing adhesive layer, 4. Release substrate, 10 Image sensor boards, 11 Housing members, 12 CMOS image sensor, 13 Cover glass, 14 First electrode, 15 individual protective film pieces, 16. Laminate of polyimide substrate and silicone-based curing adhesive layer, 17. Protective film laminate, 18 pieces processed protective film laminate, 20 individual protective films for evaluation, 21 PET film laminate, 22 Space, 23 PET film, 24 Polyimide film, 25 Silicone-based curing adhesive layer, 26 float glass, 27 A portion of the silicone-based curing adhesive layer, 100 image sensor boards, 101 Housing component, 102 CMOS image sensor, 103 Cover glass, 104 Conductive materials, 105 protective film, 106 Polyimide substrate, 107 Silicone-based curing adhesive layer, 108 Release substrate, 109 Protective film laminate, 110 Individual pieces of a laminate consisting of a polyimide substrate and a silicone-based curing adhesive layer. 111 Protective film laminate after individual piece processing

Claims

1. Polyimide substrate and The polyimide substrate is provided with a silicone-based curing adhesive layer, The above-mentioned silicone-based curable adhesive layer is obtained by curing an adhesive composition containing a curable silicone, a platinum catalyst, and a silane coupling agent. The above-mentioned curable silicone contains a slightly adhesive component (liquid A) and a strongly adhesive component (liquid B), When the above-mentioned slightly adhesive component is cured with the above-mentioned platinum catalyst, the adhesive strength to the tin surface of the float glass is less than 0.02 N / 2 cm. When the above-mentioned strong adhesive component is cured with the above-mentioned platinum catalyst, the adhesive strength to the tin surface of float glass is 0.02 to 5.0 N / 2 cm. In the above adhesive composition, the mass ratio (liquid A:liquid B) of the weakly adhesive component to the strongly adhesive component is in the range of 99:1 to 75:

25. The above silane coupling agent is a reaction product of vinyltriacetoxysilane and glycidoxypropyltrimethoxysilane. In the above adhesive composition, the content of the silane coupling agent relative to 100 parts by mass of the curable silicone is greater than 0 parts by mass and 10 parts by mass or less. A protective film used in the manufacturing of semiconductors that utilize cover glass.

2. A polyimide substrate and The polyimide substrate is provided with a silicone-based curing adhesive layer, The above-mentioned silicone-based curable adhesive layer is obtained by curing an adhesive composition containing a curable silicone, a platinum catalyst, and a silane coupling agent. The above-mentioned curable silicone contains a slightly adhesive component (liquid A) and a strongly adhesive component (liquid B), When the above-mentioned slightly adhesive component is cured with the above-mentioned platinum catalyst, the adhesive strength to the tin surface of the float glass is less than 0.02 N / 2 cm. When the above-mentioned strong adhesive component is cured with the above-mentioned platinum catalyst, the adhesive strength to the tin surface of float glass is 0.02 to 5.0 N / 2 cm. In the above adhesive composition, the mass ratio (liquid A:liquid B) of the weakly adhesive component to the strongly adhesive component is in the range of 99:1 to 75:

25. The above silane coupling agent is a reaction product of vinyltriacetoxysilane and glycidoxypropyltrimethoxysilane. In the above adhesive composition, the content of the silane coupling agent relative to 100 parts by mass of the curable silicone is greater than 0 parts by mass and 10 parts by mass or less. A protective film used in the manufacturing of CMOS sensor modules.

3. The protective film according to claim 1 or 2, wherein the silicone-based curing adhesive layer has an adhesive strength to the tin surface of float glass of 0.01 N / 2 cm or more and less than 0.07 N / 2 cm.

4. The protective film according to claim 1 or 2, wherein the content of the platinum catalyst relative to 100 parts by mass of the curable silicone is greater than 0 parts by mass and 10 parts by mass or less.

5. A protective film according to claim 1 or 2, A protective film laminate comprising the above-mentioned silicone-based curing adhesive layer, with a release substrate provided on the polyimide substrate side and the other side of the silicone-based curing adhesive layer.

6. Step a: Forming a layer made of an adhesive composition on a polyimide substrate, The process includes step b, which involves drying the above adhesive composition layer to form a silicone-based curing adhesive layer. The above adhesive composition is a composition containing a curable silicone, a platinum catalyst, and a silane coupling agent. The above-mentioned curable silicone contains a slightly adhesive component (liquid A) and a strongly adhesive component (liquid B), When the above-mentioned slightly adhesive component is cured with the above-mentioned platinum catalyst, the adhesive strength to the tin surface of the float glass is less than 0.02 N / 2 cm. When the above-mentioned strong adhesive component is cured with the above-mentioned platinum catalyst, the adhesive strength to the tin surface of float glass is 0.02 to 5.0 N / 2 cm. In the above adhesive composition, the mass ratio (liquid A:liquid B) of the weakly adhesive component to the strongly adhesive component is in the range of 99:1 to 75:

25. The above silane coupling agent is a reaction product of vinyltriacetoxysilane and glycidoxypropyltrimethoxysilane. A method for manufacturing a protective film used in the production of semiconductors using a cover glass, wherein the content of the silane coupling agent in the adhesive composition is greater than 0 parts by mass and 10 parts by mass or less, relative to 100 parts by mass of the curable silicone.

7. Step a of forming a layer made of an adhesive composition on a polyimide substrate, The process includes step b, which involves drying the above adhesive composition layer to form a silicone-based curing adhesive layer. The above adhesive composition is a composition containing a curable silicone, a platinum catalyst, and a silane coupling agent. The above-mentioned curable silicone contains a slightly adhesive component (liquid A) and a strongly adhesive component (liquid B), When the above-mentioned slightly adhesive component is cured with the above-mentioned platinum catalyst, the adhesive strength to the tin surface of the float glass is less than 0.02 N / 2 cm. When the above-mentioned strong adhesive component is cured with the above-mentioned platinum catalyst, the adhesive strength to the tin surface of float glass is 0.02 to 5.0 N / 2 cm. In the above adhesive composition, the mass ratio (liquid A:liquid B) of the weakly adhesive component to the strongly adhesive component is in the range of 99:1 to 75:

25. The above silane coupling agent is a reaction product of vinyltriacetoxysilane and glycidoxypropyltrimethoxysilane. A method for manufacturing a protective film used in the production of a CMOS sensor module, wherein the content of the silane coupling agent in the adhesive composition is greater than 0 parts by mass and 10 parts by mass or less, relative to 100 parts by mass of the curable silicone.

8. The method for manufacturing a protective film according to claim 6 or 7, wherein the silicone-based curing adhesive layer has an adhesive strength to the tin surface of float glass of 0.01 N / 2 cm or more and less than 0.07 N / 2 cm.

9. A method for producing a protective film according to claim 6 or 7, wherein the content of the platinum catalyst relative to 100 parts by mass of the curable silicone is greater than 0 parts by mass and 10 parts by mass or less.

10. A method for manufacturing a protective film according to claim 6 or 7, further comprising step c of laminating a release substrate to the polyimide substrate side and the other side of the silicone-based curing adhesive layer.

11. Step A is to place a protective film, which is a piece-shaped protective film, on the cover glass of an image sensor board comprising a housing member, a CMOS image sensor disposed on one side of the housing member, a cover glass for protecting the CMOS image sensor, and a first electrode formed on the other side of the housing member, on the cover glass of the image sensor board, the protective film being processed into individual pieces according to the shape of the cover glass. Step B involves connecting the first electrode and the second electrode of another substrate by reflow processing, The process includes step C, which involves connecting the first electrode and the second electrode, and then removing the individual protective film. The protective film described above comprises a polyimide substrate and a silicone-based curing adhesive layer disposed on the polyimide substrate. The above-mentioned silicone-based curable adhesive layer is obtained by curing an adhesive composition containing a curable silicone, a platinum catalyst, and a silane coupling agent. The above-mentioned curable silicone contains a slightly adhesive component (liquid A) and a strongly adhesive component (liquid B), When the above-mentioned slightly adhesive component is cured with the above-mentioned platinum catalyst, the adhesive strength to the tin surface of the float glass is less than 0.02 N / 2 cm. When the above-mentioned strong adhesive component is cured with the above-mentioned platinum catalyst, the adhesive strength to the tin surface of float glass is 0.02 to 5.0 N / 2 cm. In the above adhesive composition, the mass ratio (liquid A:liquid B) of the weakly adhesive component to the strongly adhesive component is in the range of 99:1 to 75:

25. The above silane coupling agent is a reaction product of vinyltriacetoxysilane and glycidoxypropyltrimethoxysilane. A method for manufacturing a CMOS sensor module, wherein the content of the silane coupling agent in the adhesive composition is greater than 0 parts by mass and 10 parts by mass or less, relative to 100 parts by mass of the curable silicone.

12. Step A1 involves preparing a protective film laminate by laminating a tape-shaped release substrate to the silicone-based curing adhesive layer side of the tape-shaped protective film, The method for manufacturing a CMOS sensor module according to claim 11, further comprising step A2 of die-cutting the above-mentioned protective film laminate to prepare a protective film laminate after die-cutting in which a plurality of the above-mentioned individual pieces of protective film are arranged on the release substrate.

13. The method for manufacturing a CMOS sensor module according to claim 11 or 12, wherein the individual protective film pieces are rectangular in shape.

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