Protective film for processing electronic components and method for manufacturing electronic components

Abstract

To provide a protective film for electronic component processing having high fixing force of a substrate for an electronic component and excellent in detachability.SOLUTION: The present disclosure relates to a protective film for electronic component processing, which has a base material and an adhesive layer arranged on one surface of the base material, wherein when the protective film for electronic component processing is attached to a SUS board and pulled in parallel with the protective film for electronic component processing and an adhesive surface of the SUS board, maximum shear stress is 0.2 MPa or more, and release strength of the protective film for electronic component processing to an adhesive tape (No. 31B manufactured by Nitto Denko Corporation) is 5 N / 25 mm or less.SELECTED DRAWING: Figure 1

Description

Technical Field

[0006] , ,

[0005] ,

[0001] The present disclosure relates to a protective film for electronic component processing and a method for manufacturing electronic components.

Background Art

[0002] As a method of cutting a substrate for electronic components and dividing it into individual electronic components, for example, a method of scribing and breaking the substrate for electronic components is known. For example, Patent Document 1 discloses a method of scribing and breaking a substrate for electronic components while being fixed by attaching it to an adhesive tape called a dicing tape.

[0003] Further, Patent Document 1 discloses that when breaking a scribed substrate for electronic components, a protective film is disposed to protect the scribed surface of the substrate for electronic components. Furthermore, as the protective film, for example, a resin film or an adhesive film is disclosed to be used.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] When a resin film is used as the protective film, the resin film simply covers the scribed surface of the substrate for electronic components. Therefore, when breaking the scribed substrate for electronic components, the fixing of the substrate for electronic components becomes insufficient, and there are problems such as the substrate for electronic components being cracked obliquely or the divided electronic components being chipped.

[0006] Furthermore, even when using an adhesive film as a protective film, if the electronic component substrate is not sufficiently secured, problems arise similar to those described above, such as the cut surface becoming slanted or electronic components being chipped when the electronic component substrate is broken.

[0007] Furthermore, according to Patent Document 1, an electronic component substrate is sandwiched between a dicing tape and a protective film, and the dicing tape and protective film are bonded together around the electronic component substrate, thereby ensuring stable fixation of the electronic component substrate. In this case, after the electronic component substrate is broken, the protective film is peeled off from the divided electronic components and the dicing tape. However, generally, the dicing tape has sufficient adhesive strength to fix the electronic component substrate and the divided electronic components. Therefore, there is a problem in that it is difficult to peel the protective film off the dicing tape.

[0008] This disclosure is made in view of the above circumstances, and its main purpose is to provide a protective film for processing electronic components that has high fixing strength for electronic component substrates and excellent peelability. [Means for solving the problem]

[0009] One embodiment of the present disclosure provides a protective film for processing electronic components, comprising a base material and an adhesive layer disposed on one surface of the base material, wherein when the protective film for processing electronic components is attached to a SUS plate and pulled parallel to the adhesive surface of the protective film for processing electronic components and the SUS plate, the maximum shear stress is 0.2 MPa or more, and the peel strength of the protective film for processing electronic components against adhesive tape (Nitto Denko Corporation NO.31B) is 5 N / 25 mm or less.

[0010] Another embodiment of the present disclosure provides a method for manufacturing an electronic component, comprising: a first application step of applying a dicing tape to one side of an electronic component substrate; a scribing step of scribing the other side of the electronic component substrate; a second application step of applying the above-mentioned protective film for processing electronic components to the scribed side of the electronic component substrate; a breaking step of breaking the electronic component substrate to which the dicing tape and the protective film for processing electronic components are applied; and a peeling step of peeling off the protective film for processing electronic components after the breaking step. [Effects of the Invention]

[0011] This disclosure provides a protective film for electronic component processing that has high fixing strength for electronic component substrates and excellent peelability. [Brief explanation of the drawing]

[0012] [Figure 1] These are schematic plan views and cross-sectional views illustrating protective films for processing electronic components in this disclosure. [Figure 2] This is a schematic diagram illustrating the method for measuring maximum shear stress. [Figure 3] This is a process diagram illustrating the manufacturing method of electronic components in this disclosure. [Figure 4] This is a process diagram illustrating a break-process using a conventional protective film for electronic component processing. [Figure 5] This is a process diagram illustrating a break process using a protective film for processing electronic components as described in this disclosure. [Figure 6] This is a schematic diagram illustrating a method for evaluating the peelability of dicing tape. [Modes for carrying out the invention]

[0013] Embodiments of this disclosure will be described below with reference to drawings and other figures. However, this disclosure can be implemented in many different ways, and should not be limited to the embodiments described below. In addition, in order to make the explanation clearer, the drawings may schematically represent the width, thickness, shape, etc. of each part compared to the actual form, but these are merely examples and should not be interpreted as limiting. Furthermore, in this specification and each figure, elements similar to those described above with respect to previously shown figures will be denoted by the same reference numerals, and detailed explanations may be omitted as appropriate.

[0014] In this specification, when describing a configuration in which one member is placed on top of another member, unless otherwise specified, the terms "on top" or "below" include both cases: when the other member is placed directly above or below the other member so as to be in contact with it, and when the other member is placed above or below the other member via yet another member. Similarly, when describing a configuration in this specification in which one member is placed on the surface of another member, unless otherwise specified, the terms "on the surface" include both cases: when the other member is placed directly above or below the other member so as to be in contact with it, and when the other member is placed above or below the other member via yet another member.

[0015] Furthermore, in this specification, the term "film" also includes a component called a "sheet."

[0016] The protective film for processing electronic components and the method for manufacturing electronic components described herein will be explained in detail below.

[0017] A. Protective film for processing electronic components The protective film for processing electronic components in this disclosure comprises a base material and an adhesive layer disposed on one side of the base material. When the protective film for processing electronic components is attached to a SUS plate and pulled parallel to the adhesive surface of the protective film for processing electronic components and the SUS plate, the maximum shear stress is 0.2 MPa or more, and the peel strength of the protective film for processing electronic components to adhesive tape (Nitto Denko Corporation NO.31B) is 5 N / 25 mm or less.

[0018] FIG. 1 is a schematic cross-sectional view showing an example of a protective film for electronic component processing in the present disclosure. As illustrated in FIG. 1, the protective film 10 for electronic component processing has a base material 1 and an adhesive layer 2 disposed on one surface of the base material 1. In the protective film 10 for electronic component processing, as shown in FIGS. 2(a) and (b) for example, when the protective film 10 for electronic component processing is attached to the SUS plate 50 and pulled in directions d1 and d2 parallel to the adhesive surface 51 of the protective film 10 for electronic component processing and the SUS plate 50, the maximum shear stress is a predetermined value or more. Also, the peel strength of the protective film 10 for electronic component processing with respect to an adhesive tape (No. 31B manufactured by Nitto Denko Corporation) is a predetermined value or less.

[0019] FIGS. 3(a) to (g) are process diagrams showing an example of a method for manufacturing an electronic component using the protective film for electronic component processing in the present disclosure. First, as shown in FIG. 3(a), the surface of the adhesive layer 22 of the dicing tape 20 having the base material 21 and the adhesive layer 22 is attached to the ring frame 31. Subsequently, as shown in FIG. 3(b), the surface of the adhesive layer 22 of the dicing tape 20 fixed to the ring frame 31 is attached to one surface of the electronic component substrate 32. Next, as shown in FIG. 3(c), the other surface of the electronic component substrate 32 fixed to the dicing tape 20 is scribed to form a scribe groove 33. Next, as shown in FIG. 3(d), the surface of the adhesive layer 2 of the protective film 10 for electronic component processing is attached to the scribed surface S1 of the electronic component substrate 32. At this time, the protective film 10 for electronic component processing is attached to the ring frame 31 and bonded to the dicing tape 20 around the electronic component substrate 32. Next, as shown in FIGS. 3(e) to (f), the scribed electronic component substrate 32 is broken. At this time, for example, a pair of receiving blades 41 are disposed on the lower surface of the electronic component substrate 32, and the electronic component substrate 32 is broken by pressing the electronic component substrate 32 with a break bar 42. Thereby, the electronic component substrate 32 is divided into individual electronic components 33. Next, as shown in FIGS. 3(f) to (g), the protective film 10 for electronic component processing is peeled off.

[0020] Here, for example, as shown in FIG. 4(a), when breaking the scribed substrate 32 for electronic components, if the fixing of the substrate 32 for electronic components and the divided electronic components 34 is insufficient, the substrate 32 for electronic components and the divided electronic components 34 may shift with respect to the protection film 100 for electronic component processing. In particular, for the divided electronic components 34, since the contact area of the electronic components 34 with respect to the protection film 100 for electronic component processing becomes small, the electronic components 34 are likely to shift with respect to the protection film 100 for electronic component processing. In this case, when pressing the substrate 32 for electronic components, the way the force is applied becomes uneven in the regions A1 and A2 on both sides of the scribing groove 33. Therefore, as shown in FIG. 4(b) for example, the substrate 32 for electronic components may crack obliquely. Also, although not shown, there is a possibility that the end of the cut surface may be chipped and the divided electronic components 34 may have chips. The protection film 100 for electronic component processing is a conventional protection film and has a base material 101 and an adhesive layer 102.

[0021] On the other hand, in the present disclosure, since the maximum shear stress when the protection film for electronic component processing is attached to the SUS plate and pulled parallel to the adhesive surface of the protection film for electronic component processing and the SUS plate is a predetermined value or more, not only the dicing tape but also the protection film for electronic component processing can sufficiently fix the substrate for electronic components and the divided electronic components. In particular, since the maximum shear stress is a predetermined value or more, the shift of the substrate for electronic components and the divided electronic components with respect to the protection film for electronic component processing can be suppressed. Therefore, when pressing the substrate 32 for electronic components, for example, as shown in FIG. (a), the force can be applied evenly in the regions A1 and A2 on both sides of the scribing groove 33. As a result, as shown in FIG. 5(b) for example, the substrate 32 for electronic components can be cut substantially perpendicular to the scribing groove 33.

[0022] Furthermore, when using a protective film for processing electronic components in the cutting process of an electronic component substrate, it is preferable that, in order to stably fix the electronic component substrate, the adhesive layer 22 surface of the dicing tape 20 and the adhesive layer 2 surface of the protective film for processing electronic components 10 are bonded together around the electronic component substrate 32, for example, as shown in Figure 3(d).

[0023] Here, the dicing tape typically has sufficient adhesive strength to fix the electronic component substrate and the divided electronic components during the cutting process of the electronic component substrate. When peeling off the protective film, if the peel strength between the dicing tape and the protective film is high, it becomes difficult to peel the protective film from the dicing tape. Conventionally, protective films have been made of resin films such as polyethylene terephthalate (PET) film or adhesive films. Generally, the peel strength between the dicing tape and PET film tends to be high. Therefore, when PET film is used as the protective film, it is difficult to peel the PET film from the dicing tape. Similarly, the peel strength between the dicing tape and the adhesive film may also be high. In this case as well, it is difficult to peel the adhesive film from the dicing tape.

[0024] In contrast, in this disclosure, the peel strength of the protective film for processing electronic components against the adhesive tape (Nitto Denko No. 31B) is below a predetermined value, allowing the protective film for processing electronic components to be easily peeled off the dicing tape. This suppresses the load placed on the divided electronic components when the protective film for processing electronic components is peeled off, thereby suppressing chipping and damage to the electronic components.

[0025] Therefore, by using the protective film for processing electronic components according to this disclosure in the manufacturing of electronic components, the yield can be improved.

[0026] The following describes the various components of the protective film for processing electronic components in this disclosure.

[0027] 1. Physical properties of protective films for electronic component processing In the protective film for processing electronic components of this disclosure, when the protective film for processing electronic components is attached to a SUS plate and pulled parallel to the adhesive surfaces of the protective film for processing electronic components and the SUS plate, the maximum shear stress is 0.2 MPa or more, preferably 0.5 MPa or more, and more preferably 1.0 MPa or more. Because the above maximum shear stress is within this range, when breaking a scribed electronic component substrate, displacement of the electronic component substrate and the divided electronic components relative to the protective film for processing electronic components can be suppressed. Therefore, when breaking a scribed electronic component substrate, force can be applied evenly to the electronic component substrate. This allows the electronic component substrate to be broken almost vertically. Thus, yield can be improved. On the other hand, the upper limit of the above maximum shear stress is not particularly limited and is set appropriately to satisfy the peel strength of the protective film for processing electronic components to the adhesive tape (Nitto Denko Corporation NO.31B) described later.

[0028] Here, the maximum shear stress can be measured by the following method. First, a test piece of protective film for electronic component processing, 50 mm in length and 10 mm in width, is prepared. The SUS plate used is SUS304, surface finish BA, thickness 1.5 mm, and size 100 mm × 150 mm. Next, as shown in Figures 2(a) and (b), the adhesive layer 2 side of the protective film for electronic component processing 10 is attached to the SUS plate 50 so that the adhesive area is 5 mm × 10 mm. Next, using a tensile testing machine, the end E1 of the SUS plate 50 opposite to the part to which the protective film for electronic component processing 10 is attached is grasped with the upper chuck of the tensile testing machine. Also, the part P of the protective film for electronic component processing that is not attached to the SUS plate 50, located about 1 mm to 2 mm away from the end E2 of the SUS plate 50, is grasped with the lower chuck of the tensile testing machine. Next, under the condition of a tensile speed of 50 mm / min, the protective film 10 for processing electronic components and the SUS plate 50 are pulled in a direction parallel to the adhesive surface 51, and in the longitudinal direction of the test piece of the protective film 10 for processing electronic components, and the shear stress is measured. The maximum value of the shear stress is then defined as the maximum shear stress.

[0029] Means for controlling the above-mentioned maximum shear stress include, for example, methods for adjusting the components or composition contained in the adhesive composition used to form the adhesive layer, and methods for adjusting the elastic modulus or Young's modulus of the substrate.

[0030] Specific methods for adjusting the components and composition of the adhesive composition include adjusting the molecular weight of the main resin component, adjusting the amount of crosslinkable functional groups in the main resin component, adjusting the glass transition temperature of the main resin component, adjusting the content of the crosslinking agent, adjusting the glass transition temperature of the additive, and adjusting the molecular weight of the additive. For example, by increasing the molecular weight of the resin component or the additive, the elastic modulus can be increased while maintaining viscosity in the adhesive layer. As a result, the maximum shear stress tends to exceed a predetermined value. Also, for example, if the amount of crosslinkable functional groups in the resin component increases, the crosslink density increases. Similarly, for example, if the content of the crosslinking agent increases, the crosslink density increases. A high crosslink density contributes to improving the elastic modulus of the adhesive layer, so the maximum shear stress tends to exceed a predetermined value. Also, for example, if the glass transition temperature of the resin component or the additive increases, the elastic modulus of the adhesive layer tends to increase, so the maximum shear stress tends to exceed a predetermined value.

[0031] Furthermore, in methods for adjusting the elastic modulus or Young's modulus of the base material, for example, when the elastic modulus or Young's modulus of the base material increases, the maximum shear stress tends to exceed a predetermined value.

[0032] In this disclosure, the peel strength of the protective film for processing electronic components from adhesive tape (Nitto Denko No. 31B) is 5 N / 25 mm or less, preferably 4 N / 25 mm or less, and more preferably 2.5 N / 25 mm or less. The above peel strength within this range allows the protective film for processing electronic components to be easily peeled from the dicing tape. On the other hand, the lower limit of the peel strength is not particularly limited and is set appropriately to satisfy the above-mentioned maximum shear stress.

[0033] Here, the peel strength of the protective film for electronic component processing against the adhesive tape (Nitto Denko No. 31B) can be measured in accordance with Method 1 of the JIS Z0237:2022 (Test Methods for Adhesive Tapes and Adhesive Sheets) (a test method in which the tape and sheet are peeled off 180° from a stainless steel test plate at a temperature of 23°C and humidity of 50%). The width of the test piece of the protective film for electronic component processing shall be 25 mm. Furthermore, the test plate to which the protective film for electronic component processing is attached is made by attaching the base surface of Nitto Denko No. 31B #50 adhesive tape (tape thickness 78 μm, base material thickness 50 μm) to a SUS plate via double-sided tape, thereby fixing the adhesive tape (Nitto Denko No. 31B) to the SUS plate and using that as the test plate. For example, a SUS304 SUS plate with a surface finish of BA, a thickness of 1.5 mm, a width of 100 mm, and a length of 150 mm can be used. For the double-sided tape, for example, double-sided tape 7565 manufactured by Teraoka Seisakusho Co., Ltd. can be used. When applying the protective film for processing electronic components to the test board, the adhesive layer of the protective film for processing electronic components is attached to the adhesive layer of the adhesive tape (NO.31B manufactured by Nitto Denko Co., Ltd.) on the test board. Then, it is cured for 24 hours. The peel strength is measured by peeling the test piece in the length direction under conditions of a peel angle of 180° and a peel speed of 300 mm / min.

[0034] Means for controlling the above-mentioned peel strength include, for example, methods for adjusting the components or composition contained in the adhesive composition used to form the adhesive layer.

[0035] Specific methods for adjusting the components and composition of the adhesive composition include adjusting the molecular weight of the main resin component, adjusting the amount of crosslinkable functional groups in the main resin component, adjusting the glass transition temperature of the main resin component, adjusting the content of the crosslinking agent, adjusting the glass transition temperature of the additive, and adjusting the molecular weight of the additive. For example, by increasing the molecular weight of the resin component or the additive, the elastic modulus can be increased while maintaining viscosity in the adhesive layer. As a result, the peel strength tends to decrease. Also, for example, if the amount of crosslinkable functional groups in the resin component increases, the crosslink density increases. Similarly, for example, if the content of the crosslinking agent increases, the crosslink density increases. A high crosslink density contributes to improving the elastic modulus of the adhesive layer, so the peel strength tends to decrease. Also, for example, if the glass transition temperature of the resin component or the additive increases, the elastic modulus of the adhesive layer tends to increase, so the peel strength tends to decrease.

[0036] In the protective film for processing electronic components of this disclosure, the adhesive force to the glass plate is preferably, for example, 1.0 N / 25 mm or less, more preferably 0.7 N / 25 mm or less, and even more preferably 0.1 N / 25 mm or less. Having the adhesive force to the glass plate within the above range allows the protective film for processing electronic components to be easily peeled off the divided electronic components. Therefore, chipping or damage to the electronic components can be suppressed when the protective film for processing electronic components is peeled off. On the other hand, in the protective film for processing electronic components of this disclosure, the lower limit of the adhesive force to the glass plate is not particularly limited, and is, for example, 0.01 N / 25 mm or more.

[0037] Here, the adhesive strength to the glass plate can be measured in accordance with Method 1 of the JIS Z0237:2022 (Test Methods for Adhesive Tapes and Sheets) (a test method in which the tape and sheet are peeled off from a stainless steel test plate at a 180° angle at a temperature of 23°C and 50% humidity), by peeling the test piece in the length direction under the conditions of a width of 25 mm, a peeling angle of 180°, and a peeling speed of 300 mm / min. The glass plate used is float glass manufactured by Nippon Tact Co., Ltd. (size 150 mm x 70 mm, thickness 2 mm).

[0038] Furthermore, in the protective film for processing electronic components of this disclosure, the adhesive force to the SUS plate is preferably, for example, 1.0 N / 25 mm or less, more preferably 0.5 N / 25 mm or less, and even more preferably 0.1 N / 25 mm or less. Because the adhesive force to the SUS plate is within the above range, the protective film for processing electronic components can be easily peeled off the divided electronic components. Therefore, chipping or damage to the electronic components can be suppressed when the protective film for processing electronic components is peeled off. On the other hand, in the protective film for processing electronic components of this disclosure, the lower limit of the adhesive force to the SUS plate is not particularly limited, and is, for example, 0.01 N / 25 mm or more.

[0039] Here, the adhesive strength to the SUS plate can be measured in accordance with Method 1 of the JIS Z0237:2022 (Test Methods for Adhesive Tapes and Sheets) (a test method in which the tape and sheet are peeled off from the stainless steel test plate at a 180° angle at a temperature of 23°C and 50% humidity), by peeling the test piece in the longitudinal direction under the conditions of a width of 25 mm, a peeling angle of 180°, and a peeling speed of 300 mm / min. For example, a SUS plate made of SUS304, with a surface finish of BA, a thickness of 1.5 mm, and dimensions of 100 mm x 150 mm is used.

[0040] 2. Adhesive layer The adhesive layer in this disclosure is not particularly limited, as long as it can sufficiently fix the electronic component substrate to the protective film for processing electronic components when the scribed electronic component substrate is broken, and can easily peel off the protective film for processing electronic components after the scribed electronic component substrate has been broken. In particular, the adhesive layer is preferably an adhesive layer that exhibits slight tackiness.

[0041] In the adhesive layer exhibiting slight tackiness, although the initial tackiness is low, when the protective film for electronic component processing is attached to the electronic component substrate, the electronic component substrate can be sufficiently fixed to the protective film for electronic component processing. Furthermore, due to the low initial tackiness, it has excellent re-peelability, and after the scribed electronic component substrate is broken, the protective film for electronic component processing can be easily peeled off.

[0042] Here, "exhibiting slight tackiness" means that when the protective film for processing electronic components is attached to the substrate for electronic components, it can sufficiently fix the substrate to the protective film, and after the scribed substrate is broken, it exhibits enough adhesive strength to allow the protective film for processing electronic components to be easily peeled off.

[0043] The adhesive properties of the protective film for processing electronic components are as described above.

[0044] (1) Material of the adhesive layer The material of the adhesive layer is not particularly limited as long as it can exhibit the adhesive properties described above. In particular, it is preferable that the adhesive layer contains a non-silicone adhesive. This prevents adverse effects from silicone residue in the post-peel-off process of the protective film for electronic component processing. The non-silicone adhesive is not particularly limited, but an acrylic adhesive is preferred.

[0045] If the adhesive layer contains an acrylic adhesive, it is sufficient that the adhesive layer contains at least an acrylic resin. In particular, the adhesive composition used to form the adhesive layer preferably contains an acrylic resin and a crosslinking agent.

[0046] Here, the statement that the adhesive layer contains an acrylic resin means that within the adhesive layer, the acrylic resin may exist as a single entity without forming crosslinks, or as a crosslinked body formed by crosslinking between acrylic resins or between an acrylic resin and another resin, and both the single entity and the crosslinked body may be present.

[0047] The following describes, with examples, the composition of adhesive compositions used to form adhesive layers.

[0048] (a) Acrylic resin The acrylic resin is not particularly limited, and examples include (meth)acrylic acid polymers obtained by homopolymerizing (meth)acrylic acid esters, and (meth)acrylic acid copolymers obtained by copolymerizing (meth)acrylic acid esters with other monomers, with (meth)acrylic acid esters as the main component. Among these, (meth)acrylic acid copolymers are preferred.

[0049] Here, in a (meth)acrylic acid ester copolymer, "having (meth)acrylic acid ester as the main component" means that in the copolymer, the proportion of (meth)acrylic acid ester is greater than 30% by mass compared to other monomers, and specifically, the copolymerization ratio is 51% by mass or more.

[0050] In this specification, (meth)acrylic acid means at least one of acrylic acid and methacrylic acid.

[0051] As the (meth)acrylic acid ester, alkyl (meth)acrylic acid esters such as linear or branched alkyl esters having 1 to 30 carbon atoms, cycloalkyl (meth)acrylic acid esters, etc. can be used. Specific examples of alkyl (meth)acrylic acid esters include those disclosed in Japanese Patent Application Publication No. 2014-101457. The (meth)acrylic acid ester may contain one or more types. Among these, (meth)acrylic acid esters having 1 to 18 carbon atoms, and particularly those having 1 to 8 carbon atoms, are preferred. The glass transition temperature of the acrylic resin tends to fall within the range described later, and the tackiness of the adhesive layer can be improved.

[0052] The above acrylic resin may be a copolymer of (meth)acrylic acid ester and monomer or oligomer. By including other monomers or oligomers as copolymer components as needed in addition to (meth)acrylic acid ester, properties such as cohesive strength and heat resistance can be improved. Examples of the above copolymer components include functional group-containing (meth)acrylates copolymerizable with (meth)acrylic acid ester. Specifically, examples include carboxyl group-containing monomers, acid anhydride group-containing monomers, hydroxyl group-containing monomers, sulfonic acid group-containing monomers, phosphate group-containing monomers, epoxy group-containing monomers, vinyl esters, vinyl ethers, aromatic vinyl compounds, etc. In addition, nitrogen-containing monomers such as cyano group-containing monomers, amide group-containing monomers, amino group-containing monomers, and isocyanate group-containing monomers may be used as copolymer components. The above copolymer components may also be included as copolymer components in the acrylic acid ester polymer.

[0053] The weight-average molecular weight of the acrylic resin is preferably between 100,000 and 2,000,000, more preferably between 200,000 and 1,000,000, and even more preferably between 400,000 and 800,000. If the weight-average molecular weight is smaller than the above range, adhesive residue may occur in the adhesive layer. On the other hand, if the weight-average molecular weight is larger than the above range, the adhesive strength may increase and the peelability may decrease.

[0054] Herein, in this specification, weight-average molecular weight is the polystyrene equivalent value measured by gel permeation chromatography (GPC). The weight-average molecular weight can be measured, for example, by using an HLC-8220GPC manufactured by Tosoh Corporation as the measuring instrument, TSKGEL-SUPERMULTIPORE-HZ-M manufactured by Tosoh Corporation as the column, THF as the solvent, and standard polystyrene with molecular weights of 1050, 5970, 18100, 37900, 96400, and 706000 as standards.

[0055] The glass transition temperature of the acrylic resin is preferably, for example, -100°C or higher and 0°C or lower, and more preferably -80°C or higher and -20°C or lower. By using an acrylic resin with a glass transition temperature within the above range as the main component of the adhesive composition, the desired adhesive properties can be more easily obtained.

[0056] The glass transition temperature of acrylic resins can be adjusted as appropriate by changing the type of monomer units used and the ratio of the monomer units combined. Even in the case of acrylic resins that are polymers (homopolymers) obtained by homopolymerizing monomers, the glass transition temperature may fall within the above range. However, this does not restrict the use of monomer units whose glass transition temperature is outside the above range. It is sufficient that the glass transition temperature of copolymers obtained by copolymerizing various monomer units falls within the above range.

[0057] In this specification, the glass transition temperature refers to the value measured by a method based on the peak top value of the loss tangent (tanδ) (DMA method). The loss tangent is determined by the ratio of the loss modulus to the storage modulus. These moduli are measured using a dynamic viscoelasticity measuring device when a force is applied to the polymer or copolymer at a constant frequency.

[0058] Acrylic resins are obtained by polymerizing monomers such as (meth)acrylic acid esters, monomers, and oligomers mentioned above using conventional methods such as solution polymerization, bulk polymerization, emulsion polymerization, or suspension polymerization.

[0059] (b) Crosslinking agent Any crosslinking agent capable of crosslinking acrylic resins is acceptable, and general crosslinking agents can be used. Examples of crosslinking agents include epoxy crosslinking agents, isocyanate crosslinking agents, metal chelate crosslinking agents, and carbodiimide crosslinking agents.

[0060] The crosslinking agent content is, for example, 0.1 parts by mass to 20 parts by mass, preferably 0.3 parts by mass to 10 parts by mass, per 100 parts by mass of acrylic resin. Having the crosslinking agent content within this range makes it easier to obtain the desired adhesive properties.

[0061] (3) Other ingredients The adhesive composition may optionally contain any additives such as lubricants, plasticizers, fillers, antistatic agents, antiblocking agents, light stabilizers, and colorants.

[0062] (2) Structure of the adhesive layer The thickness of the adhesive layer can be any thickness that allows it to exhibit the desired adhesive strength, for example, 3 μm to 50 μm, and preferably 5 μm to 40 μm.

[0063] One method for forming the adhesive layer is to apply an adhesive composition onto a substrate or separator and heat it as needed.

[0064] 3.Base material The substrate in this disclosure is a member that supports the adhesive layer.

[0065] The base material is not particularly limited. Examples of base material materials include olefin resins, vinyl chloride resins, polyester resins, urethane resins, polystyrene resins, polycarbonate resins, polyimide resins, polyamide resins, acrylic resins, fluororesins, thermoplastic elastomers, and rubber-based materials. Examples of olefin resins include low-density polyethylene, high-density polyethylene, polypropylene, polybutene, polymethylpentene, polybutadiene, ethylene vinyl acetate copolymer, ionomer resin, ethylene (meth)acrylic acid copolymer, and ethylene (meth)acrylic acid ester copolymer. Examples of vinyl chloride resins include polyvinyl chloride and vinyl chloride copolymer. Examples of polyester resins include polyethylene terephthalate and polybutylene terephthalate. Examples of polyamide resins include nylon. Examples of thermoplastic elastomers include olefin-based elastomers, vinyl chloride-based elastomers, polyester-based elastomers, styrene-based elastomers, urethane-based elastomers, acrylic-based elastomers, and amide-based elastomers. Examples of rubber-based materials include isoprene rubber, butadiene rubber, styrene-butadiene rubber, chloroprene rubber, acrylonitrile-butadiene rubber, butyl rubber, halogenated butyl rubber, acrylic rubber, urethane rubber, and polysulfide rubber. These may be used individually or in combination of two or more types.

[0066] The base material may contain various additives as needed, such as plasticizers, fillers, antioxidants, light stabilizers, antistatic agents, lubricants, dispersants, flame retardants, and colorants.

[0067] The substrate may be, for example, a single layer or a multi-layered layer.

[0068] The adhesive layer side of the substrate may be surface-treated to improve adhesion with the adhesive layer. The surface treatment is not particularly limited and includes, for example, corona treatment, plasma treatment, ozone treatment, flame treatment, primer treatment, alkali treatment, etc.

[0069] The thickness of the substrate is not particularly limited as long as it satisfies the physical properties of the protective film for processing electronic components described above, and can be appropriately selected according to the material of the substrate, etc. The thickness of the substrate may be, for example, 20 μm or more and 500 μm or less, 40 μm or more and 350 μm or less, or 50 μm or more and 200 μm or less.

[0070] 4. Other configurations The protective film for processing electronic components in this disclosure may have other components in addition to the substrate and adhesive layer described above, as needed.

[0071] A protective film for processing electronic components may have a primer layer between the substrate and the adhesive layer. The primer layer can improve the adhesion between the substrate and the adhesive layer.

[0072] The protective film for processing electronic components in this disclosure may have a separator on the side of the substrate opposite to the adhesive layer.

[0073] 5.Applications The protective film for processing electronic components of this disclosure is preferably used in the cutting process of an electronic component substrate. For example, as shown in Figure 3(d), the protective film for processing electronic components 10 is preferably used by being attached to the other side of an electronic component substrate 32 to which a dicing tape 20 is attached on one side, and the adhesive layer 22 of the dicing tape 20 and the adhesive layer 2 of the protective film for processing electronic components 10 are bonded together around the periphery of the electronic component substrate 32. In particular, the protective film for processing electronic components of this disclosure is more preferably used in the process of breaking a scribed electronic component substrate. For example, as shown in Figure 3(d), the protective film for processing electronic components 10 is preferably used by being attached to the scribed surface S1 of the electronic component substrate 32 in the process of breaking a scribed electronic component substrate 32.

[0074] B. Manufacturing methods for electronic components The method for manufacturing an electronic component in this disclosure includes: a first application step of applying a dicing tape to one side of an electronic component substrate; a scribing step of scribing the other side of the electronic component substrate; a second application step of applying the above-mentioned protective film for processing electronic components to the scribed side of the electronic component substrate; a breaking step of breaking the electronic component substrate to which the dicing tape and the protective film for processing electronic components have been applied; and a peeling step of peeling off the protective film for processing electronic components after the breaking step.

[0075] Figures 3(a) to 3(g) are process diagrams showing an example of a method for manufacturing electronic components in this disclosure. Note that Figures 3(a) to 3(g) are described in section "A. Protective Film for Processing Electronic Components" above, so their explanation is omitted here.

[0076] In this disclosure, as described in section A. Protective film for processing electronic components above, yield can be improved by using the above-mentioned protective film for processing electronic components.

[0077] The following describes each step in the manufacturing method of the electronic component as described in this disclosure.

[0078] 1. First application process In the first bonding process, dicing tape is attached to one side of the electronic component substrate.

[0079] The substrate for electronic components is not particularly limited and examples include silicon wafers, glass substrates, ceramic substrates, etc.

[0080] Dicing tape typically consists of a base material and an adhesive layer positioned on one side of the base material. A general-purpose dicing tape can be used as the dicing tape.

[0081] A common method can be applied to attach dicing tape to one side of an electronic component substrate. In this case, a ring frame is usually used. For example, as shown in Figures 3(a) and 3(b), the adhesive layer 22 side of the dicing tape 20 is attached to the ring frame 31, and then the dicing tape 20 fixed to the ring frame 31 is attached to one side of the electronic component substrate 32.

[0082] 2. Scribing process In the scribing process, the other side of the electronic component substrate is scribed.

[0083] In the scribing process, for example, a cutter wheel or laser can be used to scribe the substrate for electronic components. Typically, scribe grooves are formed in a grid pattern on the substrate for electronic components.

[0084] 3. Second application process In the second application process, the aforementioned protective film for processing electronic components is applied to the scribed surface of the electronic component substrate.

[0085] The protective films for processing electronic components are described in detail in the section "A. Protective Films for Processing Electronic Components" above, so the explanation will be omitted here.

[0086] A common method can be applied to attach a protective film for processing electronic components to the scribed surface of an electronic component substrate. For example, the electronic component substrate is placed on a stand, the protective film for processing electronic components is positioned above the substrate with its adhesive layer facing downwards, and the protective film for processing electronic components is lightly pressed down from above with a press mold to attach it to the electronic component substrate.

[0087] When attaching a protective film for processing electronic components to an electronic component substrate, it is preferable that the protective film 10 for processing electronic components be attached to the ring frame 31 and bonded to the dicing tape 20 around the electronic component substrate 32, as shown in Figure 3(d). This is because it allows the electronic component substrate to be fixed stably.

[0088] Normally, the process is carried out in the order of the first application process, the scribe process, and the second application process, but it may also be carried out in the order of the scribe process, the first application process, and the second application process.

[0089] 4. Breaking process In the breaking process, the electronic component substrate to which the dicing tape and the protective film for processing electronic components are attached is broken.

[0090] Common methods can be applied to break a scribed electronic component substrate. For example, a three-point bending method using pressure with a break bar or roller can be employed.

[0091] An example of the breaking process is shown. First, as shown in Figures 3(d) to (e), the electronic component substrate 32 is inverted so that the scribe surface 32 of the electronic component substrate 32, i.e., the protective film 10 for processing electronic components, is facing downwards. Next, as shown in Figure 3(e), the electronic component substrate 32 is placed on a support table (not shown) so that the scribe grooves 33 are located between a pair of receiving blades 41. Then, by pushing down the break bar 42 from above the dicing tape 20 toward the scribe grooves 33, the electronic component substrate 32 is bent in a three-point bending manner between the pair of receiving blades 41 and broken along the scribe grooves 33. This breaks the electronic component substrate along the scribe grooves in one direction of the grid-like scribe grooves. Subsequently, although not shown, the support table is rotated 90 degrees and the electronic component substrate is broken along the scribe grooves in the other direction in the same manner.

[0092] In the breaking process, instead of a pair of receiving blades, a cushioning material may be placed on the underside of the substrate for the electronic components.

[0093] 5. Peeling process In the peeling process, the protective film for processing electronic components is peeled off after the break process described above.

[0094] The protective film 10 for processing electronic components is peeled off from the ring frame 31, the divided electronic components 34, and the dicing tape 20, for example, as shown in Figures 3(f) to (g).

[0095] 6. Other processes After the peeling process described above, an expanding process may be performed to stretch the dicing tape and widen the gaps between electronic components, and a pick-up process may be performed to peel the electronic components from the dicing tape and pick them up. Alternatively, after the pick-up process, a die bonding process may be performed to bond the picked-up electronic components to the substrate.

[0096] Furthermore, after the peeling step described above, a third application step may be performed in which the transfer tape is applied to the side of the electronic component opposite to the dicing tape, and a transfer step may be performed in which the dicing tape is peeled off from the ring frame and the electronic component, and the ring frame and the electronic component are transferred to the transfer tape.

[0097] This disclosure is not limited to the embodiments described above. The embodiments described above are illustrative, and any configuration that is substantially identical to the technical idea described in the claims of this disclosure and achieves similar effects is included within the technical scope of this disclosure. [Examples]

[0098] The present disclosure will be further explained below with reference to examples and comparative examples.

[0099] [Example 1] An adhesive composition was prepared by diluting 100 parts by mass of an acid-free acrylic adhesive base, 8 parts by mass of a hexamethylene diisocyanate crosslinking agent, and 5 parts by mass of a carbodiimide crosslinking agent with a mixed solvent of toluene and methyl ethyl ketone (mass ratio 1:1) and thoroughly dispersing them.

[0100] The above adhesive composition was applied to a polyethylene terephthalate (PET) separator ("PET50×1-M-J2" manufactured by Nippa Co., Ltd., 50 μm thick) so that the thickness after drying was 10 μm, and the mixture was dried in a 110°C oven for 1 minute to form an adhesive layer.

[0101] A 90 μm thick polyvinyl chloride (PVC) substrate (FV5, manufactured by Ronseal Co., Ltd.) was laminated onto the above adhesive layer, and then aged at 40°C for 3 days to produce a protective film for processing electronic components.

[0102] [Example 2] A protective film for processing electronic components was prepared in the same manner as in Example 1, except that a 25 μm thick polyimide (PI) substrate ("GF100" manufactured by PI Advanced Materials, Inc.) was used instead of a PVC substrate.

[0103] [Example 3] A protective film for processing electronic components was prepared in the same manner as in Example 2, except that the adhesive composition was prepared as described below.

[0104] An adhesive composition was prepared by diluting 100 parts by mass of an acrylic adhesive base, 3.5 parts by mass of N,N'-(cyclohexane-1,3-diylbismethylene)bis(diglycidylamine), and 20 parts by mass of xylene resin with a mixed solvent of toluene and methyl ethyl ketone (mass ratio 1:1) and thoroughly dispersing them.

[0105] [Comparative Example 1] A protective film for processing electronic components was prepared in the same manner as in Example 2, except that the adhesive composition was prepared as described below.

[0106] An adhesive composition was prepared by diluting 100 parts by mass of an acrylic adhesive base, 17.5 parts by mass of epoxy resin (Mitsubishi Chemical Corporation's "jER1001"), and 0.6 parts by mass of 2-ethyl-4-methylimidazole with a mixed solvent of toluene and methyl ethyl ketone (mass ratio 1:1) and thoroughly dispersing them.

[0107] [Comparative Example 2] A 50 μm thick polyethylene terephthalate (PET) substrate (Toray Industries' "S105") was used as a protective film for processing electronic components.

[0108] [evaluation] (1) Maximum shear stress First, a protective film for processing electronic components, 10 mm wide and 50 mm long, and a SUS plate, 1.5 mm thick and measuring 100 mm x 150 mm, were prepared. The SUS plate was made of SUS304 with a surface finish of BA. Next, as shown in Figures 2(a) and (b), the adhesive layer 2 side of the protective film for processing electronic components 10 was attached to the SUS plate 50 so that the adhesive area was 5 mm x 10 mm. Then, under the condition of a tensile speed of 50 mm / min, the protective film for processing electronic components and the SUS plate were pulled in a direction parallel to the adhesive surface and along the length of the test piece of the protective film for processing electronic components, and the shear stress was measured. The maximum value of the shear stress was defined as the maximum shear stress.

[0109] (2) Peel strength against adhesive tape (Nitto Denko No. 31B) The peel strength of the adhesive tape (Nitto Denko No. 31B) was measured according to Method 1 of JIS Z0237:2022 (Test Methods for Adhesive Tapes and Sheets) (Temperature 23°C, Humidity 50%, Test Method for Peeling Tapes and Sheets from a Stainless Steel Test Plate at 180°), under the conditions of a width of 25 mm, a peel angle of 180°, and a peel speed of 300 mm / min, by peeling the test piece in the longitudinal direction. For the test plate, the adhesive tape (Nitto Denko No. 31B) was fixed to a SUS plate via double-sided tape to form the test plate. The SUS plate used was SUS304 with a thickness of 1.5 mm, dimensions of 100 mm x 150 mm, and surface finish BA. The double-sided tape used was 7565 manufactured by Teraoka Seisakusho Co., Ltd. Furthermore, the above peel strength was measured after applying a protective film for processing electronic components to the test plate and curing it for 24 hours.

[0110] (3) Adhesion to glass plate The adhesive strength to the glass plate was measured according to Method 1 of JIS Z0237:2022 (Test Methods for Adhesive Tapes and Sheets) (a test method in which the tape and sheet are peeled off a stainless steel test plate at a 180° angle at a temperature of 23°C and 50% humidity), by peeling the test piece in the longitudinal direction under conditions of a width of 25 mm, a peeling angle of 180°, and a peeling speed of 300 mm / min. The glass plate used was float glass manufactured by Nippon Tact Co., Ltd. (size 150 mm x 70 mm, thickness 2 mm).

[0111] (4) Dicing tape peelability First, a dicing tape was prepared according to the method for manufacturing adhesive tape for dicing tape described in Example 1 of Japanese Patent No. 4674836. Next, using the semi-automatic film application device "FM-3343BG" manufactured by Technovision, a 50 mm wide dicing tape 20 was applied to a ring frame 31 (Disco Corporation "MDTFR150-03") as shown in Figures 6(a) and (b). Then, a 50 mm wide protective film 10 for processing electronic components was applied to the adhesive layer surface of the dicing tape 20 and cured for 30 minutes. Figure 6(b) is a cross-sectional view taken along line AA of Figure 6(a). Next, in accordance with Method 6 of the JIS Z0237:2022 test method (test method in which the test piece is peeled off at a 90° angle to the test plate), the protective film 10 for processing electronic components was peeled off under the conditions of a peeling angle of 90° and a peeling speed of 100 mm / min, as shown in Figure 6(c), and the elongation of the dicing tape 20 was confirmed. The peelability of the dicing tape was evaluated according to the following criteria. A: In Figure 6(c), when the bottom surface of the ring frame 31 is set as the reference height h0, the dicing tape did not lift by more than 10 mm when the protective film for processing electronic components was peeled off. B: In Figure 6(c), when the bottom surface of the ring frame 31 is set as the reference height h0, the dicing tape lifted by 10 mm or more when the protective film for processing electronic components was peeled off.

[0112] [Table 1]

[0113] As shown in Table 1, the protective films for electronic component processing in Examples 1 to 3 could be easily peeled off the dicing tape. On the other hand, the protective films for electronic component processing in Comparative Examples 1 and 2 had high peel strength against adhesive tape No. 31B, and therefore were difficult to peel off from the dicing tape as well. In this case, the dicing tape stretches during peeling, which is likely to damage the wafer during use. Furthermore, the protective film for electronic component processing in Comparative Example 2 does not have adhesive properties, so it is considered that it cannot fix the electronic component substrate and electronic components. Therefore, there is a possibility that force will not be applied in the vertical direction when the electronic component substrate is broken.

[0114] This disclosure provides the following [1] to [6]. [1] A protective film for processing electronic components, comprising a base material and an adhesive layer disposed on one side of the base material, When the above-mentioned protective film for processing electronic components is attached to a SUS plate and pulled parallel to the adhesive surface of the protective film for processing electronic components and the SUS plate, the maximum shear stress is 0.2 MPa or more. A protective film for processing electronic components, wherein the peel strength of the protective film for processing electronic components against adhesive tape (Nitto Denko Corporation NO.31B) is 5N / 25mm or less. [2] The protective film for processing electronic components as described in [1], wherein the adhesive strength to the glass plate is 1.0 N / 25 mm or less. [3] The protective film for processing electronic components according to [1] or [2], wherein the adhesive layer contains a non-silicone adhesive. [4] The protective film for processing electronic components according to any one of [1] to [3], which is attached to the other side of an electronic component substrate to which a dicing tape is attached on one side, and is used by bonding the adhesive layer of the dicing tape and the adhesive layer of the protective film for processing electronic components around the periphery of the electronic component substrate. [5] A protective film for processing electronic components, as described in any of [1] to [4], which is used by being attached to the scribed surface of the electronic component substrate in the process of breaking the scribed electronic component substrate. [6] A first attachment step of attaching dicing tape to one side of an electronic component substrate, A scribing step of scribing the other side of the above-mentioned electronic component substrate, A second application step involves applying one of the electronic component processing protective films described in [1] to [5] to the scribed surface of the above-mentioned electronic component substrate, A breaking step in which the above-mentioned dicing tape and the above-mentioned protective film for processing electronic components are attached to the above-mentioned circuit board for electronic components is broken, After the above breaking process, a peeling process is performed to remove the protective film for processing the electronic components, A method for manufacturing electronic components, comprising: [Explanation of Symbols]

[0115] 1 … Base material 2 … Adhesive layer 10… Protective film for processing electronic components

Claims

1. A protective film for processing electronic components, comprising a base material and an adhesive layer disposed on one side of the base material, The adhesive layer contains a crosslinked acrylic resin, The protective film for processing electronic components is attached to a SUS plate, and when pulled parallel to the adhesive surfaces of the protective film for processing electronic components and the SUS plate, the maximum shear stress is 0.2 MPa or more. A protective film for processing electronic components is used, wherein the peel strength of the protective film for processing electronic components relative to the adhesive tape (Nitto Denko No. 31B) is 5 N / 25 mm or less, when a test is performed using a test plate in which the base surface of adhesive tape (Nitto Denko No. 31B) is attached to a SUS plate via double-sided tape, the adhesive layer surface of the protective film for processing electronic components is attached to the adhesive layer surface of the adhesive tape on the test plate, and the protective film for processing electronic components is peeled off from the test plate at a 180° angle.

2. The protective film for processing electronic components according to claim 1, wherein the adhesive strength to a glass plate is 1.0 N / 25 mm or less.

3. The protective film for processing electronic components according to claim 1 or claim 2, wherein the adhesive layer contains a non-silicone adhesive.

4. The protective film for processing electronic components according to claim 1 or 2, which is attached to the other side of an electronic component substrate to which a dicing tape is attached on one side, and is used by bonding the adhesive layer of the dicing tape and the adhesive layer of the protective film for processing electronic components around the periphery of the electronic component substrate.

5. A protective film for processing electronic components according to claim 1 or claim 2, which is used by being attached to the scribed surface of an electronic component substrate in a process of breaking a scribed electronic component substrate.

6. A first application step involves attaching dicing tape to one side of an electronic component substrate, A scribing step of scribing the other side of the aforementioned electronic component substrate, A second application step of applying the protective film for processing electronic components according to claim 1 or claim 2 to the scribed surface of the aforementioned electronic component substrate, A breaking step of breaking the electronic component substrate to which the dicing tape and the protective film for processing electronic components are attached, After the break step, a peeling step is performed to peel off the protective film for processing the electronic components, A method for manufacturing electronic components, comprising:

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