Backside grinding tape and method of manufacturing electronic devices

Abstract

A back surface polishing tape (100) capable of protecting a circuit formation surface of an electronic component in a process of grinding the electronic component, the back surface polishing tape (100) comprising a resin layer (A) (10), a resin constituting the resin layer (A) (10) having a Vicat softening point of 45°C or higher, and a buried amount of 10 μm or more as measured by a predetermined method.

Description

Technical Field

[0001] This invention relates to a back-side grinding belt and a method for manufacturing electronic devices. Background Technology

[0002] In the manufacturing method of electronic devices, after forming the circuit of electronic components (such as semiconductor wafers), a process is included in which the side of the electronic components opposite to the circuit forming surface is subjected to back-side grinding (polishing) processing.

[0003] In these processes, a back-side polishing belt is used to protect the circuit-forming side of electronic components.

[0004] As a technology related to the back-side grinding belt, the technology described in Patent Document 1 can be cited as an example.

[0005] Patent Document 1 describes an adhesive tape for protecting the surface of a semiconductor wafer. The tape is characterized by having a substrate film and an adhesive layer disposed on the substrate film. In the process of bonding a semiconductor wafer with an uneven surface to the adhesive layer and grinding the back side of the semiconductor wafer, the adhesion to SUS is measured according to JIS Z 0237 at a peel angle of 90° and a peel speed of 50 mm / min. The substrate film is planarized by grinding the uneven surface formed by bonding the semiconductor wafer to the substrate before grinding the back side of the semiconductor wafer.

[0006] According to Patent Document 1, the adhesive tape for protecting the surface of a semiconductor wafer will not peel off from the semiconductor wafer even if the back side of the adhesive tape, i.e., the substrate film, is ground. It is sufficient to grind the substrate film to transfer the unevenness of the semiconductor wafer surface during bonding, thus flattening the unevenness on the back side of the adhesive tape. There is no need to separately mold the resin and then grind it, thus simplifying the process. Furthermore, Patent Document 1 describes an adhesive tape for protecting the surface of a semiconductor wafer that can effectively flatten the back side of the tape, resulting in improved thickness accuracy when grinding the back side of the semiconductor wafer.

[0007] Existing technical documents

[0008] Patent documents

[0009] Patent Document 1: Japanese Patent Application Publication No. 2014-192464 Summary of the Invention

[0010] The problem that the invention aims to solve

[0011] In recent years, with the miniaturization of electronic devices, there has been a demand to further reduce the thickness of ground electronic components and to further improve the thickness accuracy (TTV) of ground electronic components.

[0012] The present invention was made in view of the above circumstances, and provides a back-side grinding belt capable of improving the thickness accuracy of electronic components and a method for manufacturing electronic devices.

[0013] Methods for solving problems

[0014] According to the present invention, a method for manufacturing the back-side grinding belt and the electronic device shown below is provided. [1]

[0016] A back-side grinding belt that can protect the circuit-forming surface of the electronic component during the grinding process of the electronic component, the back-side grinding belt having a resin layer (A), wherein the resin constituting the resin layer (A) has a Vicat softening point of 45°C or higher, and the embedment depth measured by the following method 1 is 10 μm or higher.

[0017] [Method 1]

[0018] A silicon wafer with a groove M having a width of 50 μm and a depth of 70 μm is heated to 90°C. With the groove M in contact with one side (SB side) of the back polishing tape, a 30N load is continuously applied for 30 seconds from the side (SA side) of the back polishing tape opposite to the SB side, using a φ7mm compression disk terminal on a digital force gauge. After the load is continuously applied, the silicon wafer with the back polishing tape attached is cooled to 23°C, and then the back polishing tape is peeled off from the silicon wafer. The amount of deformation in the height direction of the portion of the back polishing tape with the shape of the groove M transferred is taken as the embedment amount. [2]

[0020] According to the back grinding belt described above [1], the proportion of the resin layer (A) in the back grinding belt is 65% by volume or more. [3]

[0022] According to the back grinding belt described in [1] or [2] above, wherein the back grinding belt is formed from a single layer of the above resin layer (A). [4]

[0024] According to any one of the above [1] to [3], the density of the resin constituting the above resin layer (A) is 880 kg / m³. 3 above. [5]

[0026] According to any one of the above [1] to [4] back grinding belt, wherein the resin constituting the above resin layer (A) comprises at least one selected from the group consisting of ethylene-α-olefin copolymer, ethylene-vinyl ester copolymer, low-density polyethylene, polyvinyl chloride and propylene-α-olefin copolymer. [6]

[0028] According to any one of the above [1] to [5], the back grinding belt does not contain an adhesive layer, or the back grinding belt further contains an adhesive layer and the thickness of the adhesive layer is less than 10 μm. [7]

[0030] The back grinding belt according to any one of [1] to [6] above, wherein the thickness of the back grinding belt is 50 μm or more and 1000 μm or less. [8]

[0032] According to any one of [1] to [7] above, the back grinding belt can be used in a method of manufacturing an electronic device, the method of manufacturing an electronic device including a step of planarizing the surface of the back grinding belt before the step of grinding the electronic component. [9]

[0034] A method for manufacturing an electronic device includes: step (A), preparing a structure having an electronic component having a circuit forming surface and a back polishing tape, wherein the circuit forming surface side of the electronic component is attached to one side (SB side) of the back polishing tape; step (B), planarizing the side (SA side) of the back polishing tape opposite to the SB side in the structure; and step (C), after step (B), grinding the side of the electronic component opposite to the circuit forming surface side, wherein the back polishing tape has a resin layer (A), the resin constituting the resin layer (A) having a Vicat softening point of 45°C or higher, and an embedment depth of 10 μm or higher as measured by method 2 below.

[0035] [Method 2]

[0036] A silicon wafer with a groove M having a width of 50 μm and a depth of 70 μm is heated to 90°C. With the groove M in contact with the SB surface of the back polishing tape, a 30N load is continuously applied for 30 seconds from the SA surface using a φ7mm compression disk terminal on a digital force gauge. After the load is continuously applied, the silicon wafer with the back polishing tape attached is cooled to 23°C, and then the back polishing tape is peeled off from the silicon wafer. The amount of deformation in the height direction of the portion of the back polishing tape with the shape of the groove M transferred is taken as the embedment amount.

[10]

[0038] According to the manufacturing method of the electronic device described above [9], after the above-mentioned step (C), there is a step (D) of removing the back polishing belt from the above-mentioned structure.

[11]

[0040] According to the manufacturing method of the electronic device described in [9] or

[10] above, the proportion of the resin layer (A) in the back grinding belt is 65% by volume or more.

[12]

[0042] The manufacturing method of the electronic device according to any one of [9] to

[11] above, wherein the back surface grinding belt is formed from a single layer of the above resin layer (A).

[13]

[0044] According to the manufacturing method of the electronic device according to any one of [9] to

[12] above, the density of the resin constituting the resin layer (A) is 880 kg / m³. 3 above.

[14]

[0046] The method for manufacturing an electronic device according to any one of [9] to

[13] above, wherein the resin constituting the resin layer (A) comprises at least one selected from the group consisting of ethylene-α-olefin copolymer, ethylene-vinyl ester copolymer, low-density polyethylene, polyvinyl chloride and propylene-α-olefin copolymer.

[15]

[0048] The method of manufacturing an electronic device according to any one of [9] to

[14] above, wherein the back polishing belt does not contain an adhesive layer, or the back polishing belt further contains an adhesive layer and the thickness of the adhesive layer is less than 10 μm.

[16]

[0050] The manufacturing method of the electronic device according to any one of [9] to

[15] above, wherein the thickness of the back surface grinding belt is 50 μm or more and 1000 μm or less.

[0051] Invention Effects

[0052] According to the present invention, a back-side grinding belt capable of improving the thickness accuracy of electronic components and a method for manufacturing electronic devices can be provided. Attached Figure Description

[0053] Figure 1 This is a cross-sectional view schematically showing an example of the back-side grinding belt of this embodiment.

[0054] Figure 2 This is a diagram used to illustrate method 1.

[0055] Figure 3 This is a cross-sectional view schematically showing an example of a structure in process (A). Detailed Implementation

[0056] Hereinafter, embodiments of the present invention will be described using the accompanying drawings. Furthermore, in all the drawings, the same reference numerals are used to denote the same structural elements, and descriptions are omitted where appropriate. Also, the drawings are schematic diagrams and do not conform to actual size ratios. Furthermore, unless otherwise specified, the numerical range "A~B" indicates A or more and B or less. Additionally, in this specification, "(meth)acrylic acid" refers to "at least one of acrylic acid and methacrylic acid".

[0057] Conventional electronic device manufacturing methods include, for example, a manufacturing method comprising the following steps: a step of preparing a structure by bonding an electronic component with a back grinding tape; and a step of grinding the surface of the electronic component in the structure opposite to the surface with the back grinding tape.

[0058] According to the inventors' research, the thickness accuracy of the electronic component deteriorates after grinding due to the unevenness of the back grinding strip on the side opposite to the electronic component side of the structure before grinding. Particularly when the electronic component has an uneven structure, there is a tendency for the unevenness of the back grinding strip thickness to worsen further.

[0059] As a method for manufacturing electronic devices to improve the thickness accuracy of electronic components after grinding, the inventors have studied a method for manufacturing electronic devices comprising the following steps: prior to the grinding of the electronic components, grinding the surface of the back grinding belt in a structure formed by bonding the electronic components with the back grinding belt to make it flat.

[0060] However, according to the inventor's research, it has been clarified that there is room for improvement in the manufacturing method of such electronic devices from the perspective of improving the thickness accuracy of electronic components.

[0061] Furthermore, the inventors have discovered that, according to the manufacturing method of such an electronic device, the machinability of the back grinding belt (hereinafter also referred to as "belt machinability") and the thickness accuracy of the electronic components are in an inverse relationship.

[0062] The present invention was made in view of the above circumstances, and provides a back-side grinding belt capable of improving the thickness accuracy of electronic components and a method for manufacturing electronic devices.

[0063] Furthermore, the present invention can provide a method for manufacturing a back-side grinding belt and an electronic device that can improve the performance balance between grinding capability and thickness accuracy of electronic components.

[0064] [Back grinding belt]

[0065] The back grinding belt of this embodiment is a back grinding belt that can protect the circuit forming surface of the electronic component during the grinding process of the electronic component. The back grinding belt has a resin layer (A), the resin constituting the resin layer (A) has a Vicat softening point of 45°C or higher, and the embedment amount measured by method 1 is 10 μm or higher.

[0066] As mentioned above, a back-side grinding belt that can improve the thickness accuracy of electronic components is required.

[0067] The inventors conducted in-depth research and obtained the following insights: In a back-side grinding belt having a resin layer (A), the Vicat softening point of the resin constituting the resin layer (A) and the embedment amount measured by method 1 are effective design indicators for improving the thickness accuracy of electronic components.

[0068] Figure 1 This is a schematic cross-sectional view showing an example of the back-side polishing belt of this embodiment. The back-side polishing belt 100 includes a resin layer (A) 10.

[0069] The embedment depth of the back grinding belt 100, as determined by method 1, is 10 μm or more.

[0070] From the viewpoint of further improving the thickness accuracy of electronic components, the embedment amount of the back grinding tape 100 is preferably 15 μm or more, more preferably 20 μm or more, even more preferably 30 μm or more, even more preferably 40 μm or more, even more preferably 50 μm or more, even more preferably 55 μm or more, even more preferably 60 μm or more, even more preferably 62 μm or more, even more preferably 64 μm or more, and the upper limit is not particularly limited, for example, it can be 70 μm or less.

[0071] [Method 1]

[0072] A silicon wafer with a groove M having a width of 50 μm and a depth of 70 μm is heated to 90°C. With the groove M in contact with one side (SB side) of the back polishing tape, a 30N load is continuously applied for 30 seconds from the opposite side (SA side) of the back polishing tape, using a φ7mm compression disk terminal on a digital force gauge. After the load is continuously applied, the silicon wafer with the back polishing tape attached is cooled to 23°C, and then the back polishing tape is peeled off from the silicon wafer. The amount of deformation in the height direction of the portion of the back polishing tape with the shape of the groove M transferred is taken as the embedment amount.

[0073] Figure 2 This is a diagram used to illustrate method 1. (Using...) Figure 2 Method 1 will be explained in detail.

[0074] First, prepare a silicon wafer 200 with a groove M having a width of 50 μm and a depth of 70 μm. Next, heat the silicon wafer 200 to 90°C, with the groove M of the silicon wafer 200 in contact with the SB surface of the back-side polishing tape 100. Figure 2 (a) A φ7mm compression disc terminal 300 is set on a digital force gauge (not shown) from the SA side of the back grinding belt, and a load of 30N is continuously applied for 30 seconds. Figure 2 (b)). After cooling the silicon wafer 200 to 23°C, the back polishing tape 100 is peeled off from the silicon wafer 200. On the SB side of the back polishing tape 100, the deformation amount H in the height direction of the portion with the transferred groove M shape is taken as the embedment amount. Figure 2 (c)).

[0075] The embedment amount of the back grinding belt 100 can be set to a desired value by appropriately adjusting the type of resin constituting the resin layer (A) 10, the thickness of the resin layer (A) 10, the proportion of the resin layer (A) 10 in the back grinding belt 100, etc.

[0076] The thickness of the back abrasive belt 100 is preferably 50 μm or more, more preferably 70 μm or more, even more preferably 100 μm or more, even more preferably 120 μm or more, even more preferably 140 μm or more, even more preferably 150 μm or more, and preferably 1000 μm or less, more preferably 800 μm or less, even more preferably 600 μm or less, even more preferably 400 μm or less, even more preferably 300 μm or less, even more preferably 200 μm or less.

[0077] The thickness of the back abrasive belt 100 is preferably 50 μm or more and 1000 μm or less, more preferably 70 μm or more and 800 μm or less, even more preferably 100 μm or more and 600 μm or less, even more preferably 120 μm or more and 400 μm or less, even more preferably 140 μm or more and 300 μm or less, and even more preferably 150 μm or more and 200 μm or less.

[0078] The following describes each layer of the back grinding belt 100.

[0079] <Resin Layer (A)>

[0080] The back grinding belt 100 has a resin layer (A) 10.

[0081] The Vicat softening point of the resin constituting resin layer (A)10 is above 45°C.

[0082] From the viewpoint of further improving machinability and further improving the thickness accuracy of electronic components, the Vicat softening point of the resin constituting resin layer (A) 10 is preferably 47°C or higher, more preferably 50°C or higher, even more preferably 53°C or higher, even more preferably 55°C or higher, even more preferably 57°C or higher, and the upper limit is not particularly limited, for example, it can be 190°C or lower, 180°C or lower, 150°C or lower, 120°C or lower, 100°C or lower, or 70°C or lower.

[0083] From the viewpoint of further improving machinability and further improving the thickness accuracy of electronic components, the Vicat softening point of the resin constituting resin layer (A) 10 is preferably 45°C or higher and 190°C or lower, more preferably 47°C or higher and 180°C or lower, even more preferably 50°C or higher and 150°C or lower, even more preferably 53°C or higher and 120°C or lower, even more preferably 55°C or higher and 100°C or lower, and even more preferably 57°C or higher and 70°C or lower.

[0084] The Vicat softening point of the resin constituting resin layer (A)10 refers to the value determined according to ASTM D 1525.

[0085] Here, when there are two or more resins constituting resin layer (A) 10, the Vicat softening point of the resin constituting resin layer (A) 10 can be the Vicat softening point of the mixture obtained by melting and mixing two or more resins using a known method.

[0086] The type of resin constituting resin layer (A) 10 is not particularly limited, but preferably includes at least one selected from the group consisting of ethylene-α-olefin copolymer, ethylene-vinyl ester copolymer, low-density polyethylene, polyvinyl chloride and propylene-α-olefin copolymer, more preferably includes at least one selected from the group consisting of ethylene-α-olefin copolymer and ethylene-vinyl ester copolymer, and even more preferably includes at least one selected from the group consisting of ethylene-α-olefin copolymer and ethylene-vinyl acetate copolymer.

[0087] In the ethylene-α-olefin copolymer, the α-olefin is, for example, an α-olefin with 3 or more and 20 or less carbon atoms, preferably an α-olefin with 3 or more and 10 or less carbon atoms, more preferably an α-olefin with 3 or more and 8 or less carbon atoms, and even more preferably an α-olefin with 3 or more and 5 or less carbon atoms.

[0088] Examples of such α-olefins include propylene, 1-butene, 1-pentene, 1-hexene, 3-methyl-1-butene, 3,3-dimethyl-1-butene, 4-methyl-1-pentene, 1-octene, 1-decene, and 1-dodecene, among which propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, and 1-octene are preferred.

[0089] Ethylene-α-olefin copolymers can be random copolymers or block copolymers.

[0090] In the propylene-α-olefin copolymer, the α-olefin is, for example, an α-olefin with 2 or more and 20 or less carbon atoms (excluding propylene), preferably an α-olefin with 2 or more and 10 or less carbon atoms (excluding propylene), more preferably an α-olefin with 2 or more and 8 or less carbon atoms (excluding propylene), and even more preferably an α-olefin with 2 or more and 5 or less carbon atoms (excluding propylene).

[0091] Examples of such α-olefins include ethylene, 1-butene, 1-pentene, 1-hexene, 3-methyl-1-butene, 3,3-dimethyl-1-butene, 4-methyl-1-pentene, 1-octene, 1-decene, and 1-dodecene, among which ethylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, and 1-octene are preferred.

[0092] Propylene-α-olefin copolymers can be random copolymers or block copolymers.

[0093] Examples of ethylene-vinyl ester copolymers include ethylene-vinyl acetate copolymers, ethylene-vinyl propionate copolymers, ethylene-vinyl butyrate copolymers, and ethylene-vinyl stearate copolymers, among which ethylene-vinyl acetate copolymers are preferred.

[0094] From the viewpoint of further improving machinability and thickness accuracy of electronic components, the density of the resin constituting resin layer (A)10 is preferably 880 kg / m³. 3 The above is preferred, with 885 kg / m³ being even more desirable. 3 The above is further optimized to 890 kg / m 3 The above, and the upper limit is not specifically limited, for example it can be 1500 kg / m³. 3 The following can be 1200 kg / m 3 The following can also be 1000 kg / m 3 the following.

[0095] From the viewpoint of further improving machinability and thickness accuracy of electronic components, the density of the resin constituting resin layer (A)10 is preferably 880 kg / m³.3 Above and 1500 kg / m 3 The following is more preferably 885 kg / m 3 Above and 1200kg / m 3 The following is a further preferred value: 890 kg / m 3 Above and 1000 kg / m 3 the following.

[0096] The density of the resin constituting resin layer (A)10 refers to the value measured according to ASTM D 1505.

[0097] Here, when there are two or more resins constituting resin layer (A) 10, the density of the resin constituting resin layer (A) 10 can be obtained by using a known method to melt and mix two or more resins to obtain the density of the mixture.

[0098] The thickness of the resin layer (A) 10 is preferably 50 μm or more, more preferably 70 μm or more, even more preferably 100 μm or more, even more preferably 120 μm or more, even more preferably 140 μm or more, even more preferably 150 μm or more, and preferably 1000 μm or less, more preferably 800 μm or less, even more preferably 600 μm or less, even more preferably 400 μm or less, even more preferably 300 μm or less, even more preferably 200 μm or less.

[0099] The thickness of the resin layer (A) 10 is preferably 50 μm or more and 1000 μm or less, more preferably 70 μm or more and 800 μm or less, even more preferably 100 μm or more and 600 μm or less, even more preferably 120 μm or more and 400 μm or less, even more preferably 140 μm or more and 300 μm or less, and even more preferably 150 μm or more and 200 μm or less.

[0100] The proportion of resin layer (A) 10 in the back grinding belt 100 is preferably 65% ​​by volume or more, more preferably 75% by volume or more, even more preferably 80% by volume or more, even more preferably 90% by volume or more, even more preferably 95% by volume or more, even more preferably 97% by volume or more, even more preferably 99% by volume or more, and, for example, 100% by mass or less.

[0101] Here, the proportion of the resin layer (A) 10 is the value when the back polishing tape in the state of being bonded to the electronic component is set to 100% by volume. That is, the back polishing tape 100 may sometimes have a protective film or the like that peels off when bonded to the electronic component, but such a protective film is not included in the reference value of the volume of the back polishing tape.

[0102] In addition to resin components, resin layer (A)10 may also contain fillers and other components. The content of components other than resin components is appropriate.

[0103] When the total content of all components contained in the resin layer (A) 10 is set to 100% by mass, the content of resin components in the resin layer (A) 10 is preferably 60% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, even more preferably 90% by mass or more, even more preferably 95% by mass or more, even more preferably 97% by mass or more, even more preferably 99% by mass or more, and, for example, 100% by mass or less.

[0104] <Other Layers>

[0105] The back grinding belt 100 may appropriately have other layers besides the resin layer (A) 10.

[0106] Other layers include, for example, layers containing a protective film. This protective film is a layer provided to protect the back-side polishing tape 100 and is peeled off when the back-side polishing tape is attached to the electronic component.

[0107] The back grinding belt 100 is preferably formed of a single layer of resin layer (A) 10.

[0108] Here, the above description refers to the state in which the back polishing tape 100 is formed of a single layer of resin layer (A) 10 when the back polishing tape is attached to the electronic component.

[0109] For example, when the back polishing tape 100 has a two-layer structure comprising a single resin layer (A) 10 and a protective film, the protective film is peeled off when the back polishing tape is attached to the electronic component. Therefore, when the back polishing tape is attached to the electronic component, the back polishing tape 100 is formed by a single resin layer (A) 10.

[0110] The back-side abrasive belt 100 preferably does not contain an adhesive layer, or the back-side abrasive belt further contains an adhesive layer with a thickness of less than 10 μm, more preferably it does not contain an adhesive layer. When the back-side abrasive belt 100 further contains an adhesive layer, the thickness of the adhesive layer is more preferably less than 5 μm, more preferably less than 3 μm, and more preferably less than 1 μm.

[0111] The adhesive layer is, for example, a layer formed by a known adhesive.

[0112] Examples of adhesives include (meth)acrylic adhesives and silicone adhesives.

[0113] <Manufacturing Method of Backside Grinding Belt>

[0114] The manufacturing method of the back abrasive belt 100 is not particularly limited. For example, the back abrasive belt can be manufactured by forming a resin layer (A) by extrusion molding; or by coating a resin film on a resin film and drying it to form a resin layer (A).

[0115] <Applications of the back abrasive belt>

[0116] The back grinding belt 100 is a back grinding belt that can protect the circuit forming surface of the electronic component during the grinding process of the electronic component. It is preferably a back grinding belt that can be used in a manufacturing method of an electronic device, which includes a process of planarizing the surface of the back grinding belt before the grinding process of the electronic component.

[0117] The back-side grinding belt 100 is more preferably used in the manufacturing method of the electronic device described later.

[0118] The preferred method for the grinding process of electronic components is the same as the preferred method for process (C) in the electronic device manufacturing method described later, and the preferred method for the process of planarizing the surface of the back grinding belt is the same as the preferred method for process (B) in the electronic device manufacturing method described later.

[0119] [Manufacturing Methods for Electronic Devices]

[0120] The method for manufacturing an electronic device according to this embodiment includes: step (A), preparing a structure having an electronic component having a circuit forming surface and a back polishing belt, wherein the circuit forming surface side of the electronic component is attached to one side (SB side) of the back polishing belt; step (B), planarizing the side (SA side) of the back polishing belt opposite to the SB side in the structure; and step (C), after step (B), grinding the side of the electronic component opposite to the circuit forming surface side, wherein the back polishing belt has a resin layer (A), the resin constituting the resin layer (A) has a Vicat softening point of 45°C or higher, and the embedment depth measured by method 2 is 10 μm or higher.

[0121] [Method 2]

[0122] A silicon wafer with a groove M having a width of 50 μm and a depth of 70 μm is heated to 90°C. With the groove M in contact with the SB side of the back polishing tape, a 30N load is continuously applied for 30 seconds from the SA side using a φ7mm compression disk terminal on a digital force gauge. After the load is continuously applied, the silicon wafer with the back polishing tape attached is cooled to 23°C, and then the back polishing tape is peeled off from the silicon wafer. The amount of deformation in the height direction of the portion of the back polishing tape with the shape of the groove M transferred is taken as the embedment amount.

[0123] The preferred method for the back-side grinding belt in the manufacturing method of the electronic device in this embodiment is the same as the preferred method for the back-side grinding belt described above.

[0124] It should be noted that the preferred method for the embedment amount determined by method 2 is the same as the preferred method for the embedment amount determined by method 1.

[0125] In this embodiment, "electronic device" refers to components, devices, and final products that utilize electronic engineering technologies, such as semiconductor devices, power semiconductor devices, semiconductor chips, semiconductor elements, printed wiring substrates, circuit display devices, information communication terminals, light-emitting diodes, physical batteries, and chemical batteries.

[0126] The following describes each step of the electronic device according to this embodiment.

[0127] <Process (A)>

[0128] Figure 3 This is a cross-sectional view schematically showing an example of structure 500 in process (A).

[0129] The method for manufacturing an electronic device according to this embodiment includes: step (A), preparing a structure 500, the structure 500 having an electronic component 400 having a circuit forming surface 400A and a back polishing belt 100, wherein the circuit forming surface 400A side of the electronic component 400 is attached to one side (SB side) of the back polishing belt 100.

[0130] The structure 500 can be manufactured by attaching the back grinding belt 100 to the circuit forming surface 400A of the electronic component 400.

[0131] There is no particular limitation on the method of bonding the back abrasive tape 100 to the circuit forming surface 400A of the electronic component 400. The bonding can be performed by known methods, such as by manual labor or by a device called an automatic bonding machine equipped with a roll of back abrasive tape 100.

[0132] When the back polishing tape 100 is attached to the circuit forming surface 400A of the electronic component 400, for example, the attachment can be performed while heating at least one of the electronic component 400 and the back polishing tape 100.

[0133] There are no particular limitations on the heating temperature; for example, it can be above 40°C, above 60°C, below 150°C, or below 120°C.

[0134] The electronic component 400 is not particularly limited, but may include, for example, semiconductor wafers, sapphire substrates, lithium tantalate substrates, molded wafers, molded panels, molded array packages, semiconductor substrates, etc., wherein semiconductor wafers are preferred.

[0135] Examples of semiconductor wafers include silicon wafers, sapphire wafers, germanium wafers, germanium-arsenic wafers, gallium-phosphorus wafers, gallium-arsenic-aluminum wafers, gallium-arsenic wafers, and lithium tantalate wafers, among which silicon wafers are preferred.

[0136] The circuit forming surface 400A of the electronic component 400 has circuits such as wiring, capacitors, diodes, or transistors formed on its surface. Alternatively, the circuit forming surface 400A may be subjected to plasma treatment.

[0137] The circuit forming surface 400A of the electronic component 400 preferably has a concave-convex structure.

[0138] Generally speaking, if the circuit forming surface 400A of the electronic component 400 has a concave-convex structure, then due to the concave-convex structure, there is a tendency for the thickness accuracy of the structure 500 to decrease, and the thickness accuracy of the electronic component 400 after grinding to decrease.

[0139] On the other hand, the manufacturing method of the electronic device in this embodiment can improve the thickness accuracy of electronic components. Therefore, even when the circuit forming surface 400A of the electronic component 400 has an uneven structure, the thickness accuracy of the electronic component is improved.

[0140] The aforementioned concave-convex structure preferably includes convex electrodes.

[0141] Regarding bump electrodes, for example, when an electronic device is mounted on a mounting surface, they are joined with electrodes formed on the mounting surface to form an electrical connection between the electronic device and the mounting surface (mounting surface of a printed circuit board, etc.).

[0142] Examples of bump electrodes include spherical bumps, printed bumps, nail head bumps, electroplated bumps, and cylindrical bumps. In other words, bump electrodes are typically convex electrodes. These bump electrodes can be used individually or in combination of two or more types.

[0143] The height of the bump electrode is preferably 2 μm or more, more preferably 5 μm or more, even more preferably 10 μm or more, even more preferably 50 μm or more, and preferably 600 μm or less, more preferably 500 μm or less, even more preferably 400 μm or less, and even more preferably 300 μm or less.

[0144] The preferred range for the diameter of the convex electrode is the same as the preferred range for the height of the convex electrode.

[0145] The spacing between the bumps of the bump electrode is not particularly limited, but is preferably 5 μm or more, more preferably 50 μm or more, even more preferably 100 μm or more, and preferably 600 μm or less, more preferably 500 μm or less.

[0146] Here, the so-called convex distance of the convex electrode, in the case of adjacent convex points A and B, refers to the distance between the end of convex point A on the convex point B side and the end of convex point B on the convex point A side.

[0147] There are no particular limitations on the types of metals used to form the bump electrodes; examples include solder, silver, gold, copper, tin, lead, bismuth, and their alloys. A single type of metal may be used, or two or more may be used in combination.

[0148] <Process (B)>

[0149] The manufacturing method of the electronic device in this embodiment includes a step (B) of planarizing the SA surface of the back grinding belt 100 in the structure 500.

[0150] Process (B) is performed after process (A). There can be any number of processes between process (A) and process (B).

[0151] After step (A), unevenness sometimes occurs on the SA surface of the back grinding belt 100 in the structure 500. Step (B) is a step to flatten the unevenness produced on the SA surface of the back grinding belt 100.

[0152] In process (B), there is no particular limitation on the method of making the SA surface of the back grinding belt 100 flat. It can be appropriately selected according to the depth of the concave part (the height of the convex part) generated on the SA surface. For example, the method of flattening by grinding the SA surface, the method of flattening by grinding the SA surface, and the method of flattening by cutting the SA surface can be cited. Among these, the method of flattening by grinding the SA surface is preferred.

[0153] In process (B), there is no particular limitation on the more specific way to flatten the SA surface of the back grinding belt 100. For example, a known grinding method, a known lapping method, a known cutting method, etc. can be appropriately selected.

[0154] <Process (C)>

[0155] The method for manufacturing an electronic device according to this embodiment includes a step (C) of grinding the surface 400B of an electronic component 400 opposite to the circuit forming surface.

[0156] Process (C) is performed after process (B). There can be any process between process (B) and process (C).

[0157] Process (C) is a process that thins the electronic component 400 to a predetermined thickness without damaging it. For example, the structure 500 is fixed to the chuck table of a grinding machine, and the surface 400B of the electronic component 400 opposite to the circuit formation surface is ground.

[0158] In process (C), the electronic component 400 is ground to a thickness below the desired thickness. The thickness of the electronic component 400 before grinding is appropriately determined according to the diameter, type, etc. of the electronic component 400, and the thickness of the electronic component 400 after grinding is appropriately determined according to the size of the obtained chip, the type of circuit, etc.

[0159] There are no particular limitations on the grinding method in process (C), and well-known grinding methods can be used. Grinding can be performed while supplying water to cool the electronic component 400 and the grinding stone. If necessary, a dry polishing process, which does not use grinding water, can be performed at the end of the grinding process.

[0160] Alternatively, chemical etching can be performed after grinding the surface 400B of the electronic component 400 opposite to the circuit formation surface. Chemical etching is performed by immersing the electronic component 400 in an etching solution with the back-side abrasive tape 100 attached. The etching solution is selected from the group consisting of: acidic aqueous solutions composed of hydrofluoric acid, nitric acid, sulfuric acid, acetic acid, or mixtures thereof; and alkaline aqueous solutions such as potassium hydroxide and sodium hydroxide. Etching is performed for purposes such as removing strain generated on the back side of the electronic component 400, further thinning the electronic component 400, removing oxide films, and pretreatment when forming electrodes on the back side. The etching solution is appropriately selected according to these purposes.

[0161] <Process (D)>

[0162] The manufacturing method of the electronic device in this embodiment preferably further includes a step (D) of removing the back grinding belt 100 from the structure 500.

[0163] Operation (D) is performed after operation (C). There can be any number of operations between operation (C) and operation (D).

[0164] In process (D), there is no particular limitation on the method of removing the back grinding belt 100 from the structure 500. It can be done manually or by a device called an automatic peeling machine.

[0165] In process (D), the back grinding belt 100 can be heated as needed, and the heating temperature can be set to a range of 50°C or higher and 120°C or lower.

[0166] The surface of the electronic component 400, after removing the back abrasive belt 100, can be cleaned as needed. Examples of cleaning methods include wet cleaning such as water cleaning and solvent cleaning, and dry cleaning such as plasma cleaning. In the case of wet cleaning, ultrasonic cleaning can also be used. The cleaning method should be selected appropriately based on the degree of contamination on the surface of the electronic component 400.

[0167] <Other processes>

[0168] The manufacturing method of the electronic device in this embodiment may also include other processes besides those described above.

[0169] Other processes include any process commonly performed in the manufacturing process of electronic components, such as resist processing, developing processing, ashing processing, sputtering processing, dicing processing, chip bonding processing, wire bonding processing, flip chip bonding processing, curing and heating testing processing, sealing processing, and reflow processing.

[0170] The embodiments of the present invention have been described above, but these are merely examples of the present invention, and various configurations other than those described above are also possible.

[0171] It should be noted that the present invention is not limited to the above-described embodiments, and modifications and improvements within the scope of achieving the purpose of the present invention are also included in the present invention.

[0172] Example

[0173] The present invention will be specifically described below through examples and comparative examples, but the present invention is not limited thereto.

[0174] [raw material]

[0175] PE1: Ethylene-α-olefin copolymer (manufactured by Mitsui Chemicals Co., Ltd., product name: TAFMER A-4090S)

[0176] PE2: Ethylene-α-olefin copolymer (manufactured by Mitsui Chemicals Co., Ltd., product name: TAFMER A-4070)

[0177] • EVA1: Ethylene-vinyl acetate copolymer (manufactured by Mitsui & Dow Polymer Chemicals Co., Ltd., product name: EVAFLEXEV460)

[0178] •PET1: Polyethylene terephthalate film (manufactured by Toray Industries, Inc., product name: Lumirror #50-T83)

[0179] • LLDPE1: Low-density polyethylene (manufactured by Prime Polymer Co., Ltd., product name: Evolue SP2320)

[0180] <Preparation of Acrylic-based 1>

[0181] Ethyl acrylate (49 parts by mass), 2-ethylhexyl acrylate (20 parts by mass), methyl acrylate (21 parts by mass), glycidyl methacrylate (10 parts by mass), and benzoyl peroxide polymerization initiator (0.5 parts by mass) were reacted in toluene (65 parts by mass) and ethyl acetate (50 parts by mass) at 80°C for 10 hours. After the reaction was completed, the solution was cooled, and xylene (25 parts by mass), acrylic acid (5 parts by mass), and tetradecyl dimethyl benzyl ammonium chloride (0.5 parts by mass) were added. The mixture was then reacted at 85°C for 32 hours while air was being purged to obtain an acrylic solution.

[0182] Acrylic adhesive solution was obtained by adding 0.9 parts by mass of crosslinking agent, 6.9 parts by mass of photopolymerization initiator, and 12 parts by mass of polyfunctional acrylate to 100 parts by mass of acrylic solution (solid component). The obtained acrylic adhesive solution was designated as acrylic 1.

[0183] [Examples 1 and 2]

[0184] The resin described in resin layer (A) of Table 1 was used to form a film by extrusion molding to achieve the thickness of the resin described in resin layer (A) of Table 1, and back-side grinding belts of Examples 1 and 2 were obtained respectively.

[0185] [Comparative Example 1]

[0186] On PET1, LLDPE1 was extruded to form a film with a thickness of 95 μm to obtain the back abrasive belt of Comparative Example 1.

[0187] [Comparative Example 2]

[0188] Acrylic 1 was coated onto PET1 and dried to form a resin layer (B) with a thickness of 120 μm, resulting in the back-side abrasive belt of Comparative Example 2.

[0189] [Comparative Example 3]

[0190] EVA1 was extruded to a thickness of 120 μm. Then, acrylic 1 was coated onto the EVA1 film and dried to form a resin layer (B) with a thickness of 110 μm, thus obtaining the back-side abrasive belt of Comparative Example 3.

[0191] [Comparative Example 4]

[0192] Except for changing the type of resin, the back-side grinding belt of Comparative Example 4 was obtained by the same method as in Examples 1 and 2.

[0193] [Measurement and Evaluation]

[0194] <Determination of Resin Density>

[0195] Determine the density of the resin [kg / m³] according to ASTM D 1505. 3 ].

[0196] <Determination of Vicat Softening Point of Resin>

[0197] The Vicat softening point [°C] of the resin was determined according to ASTM D 1525.

[0198] <Determination of the embedment amount of the back grinding belt>

[0199] Prepare a silicon wafer with a groove M of 50 μm width and 70 μm depth. Next, heat the silicon wafer to 90°C using a hot plate. With the groove M of the silicon wafer in contact with one side (SB side) of the back polishing tape, apply a 30 N load continuously for 30 seconds from the opposite side (SA side) of the back polishing tape, using a φ7 mm compression disk terminal on a digital force gauge (manufactured by A&D Corporation, product name: AD-4932A-50N). It should be noted that the load was continuously applied under the conditions of 50% RH and atmospheric conditions.

[0200] After continuous application of load, the silicon wafer with the back polishing tape attached is cooled to 23°C, and the back polishing tape is peeled off from the silicon wafer. On the SB side of the back polishing tape, the amount of deformation in the height direction of the part with the shape of the groove M is measured using a shape analysis laser microscope (KEYENCE Co., Ltd., product name: VK-X1000). The height of the protrusion is obtained from the profile, and the height of the protrusion is taken as the embedment amount [μm].

[0201] It should be noted that in the measurement of embedment depth, the silicon wafer size was Φ200mm, the silicon wafer thickness was 725μm, and the back surface polishing tape size was 30mm×30mm. Groove M is cuboid in shape and formed by cross-cutting the wafer. That is, the lateral width of groove M is 50μm, and the longitudinal width is 200mm (wafer diameter). Furthermore, groove M is located at the center of the silicon wafer surface, and the φ7mm compression disk terminal is located at the top of groove M.

[0202] <Evaluation of abrasiveness>

[0203] The silicon wafer (circuit forming surface height: 35μm) is bonded to the back polishing tape by contacting the SB surface of the back polishing tape, thus obtaining a structure formed by bonding the silicon wafer and the back polishing tape.

[0204] Next, the SA surface of the back grinding belt of the obtained structure was ground using a grinding device (DISCO Corporation, product name: DMG 8762).

[0205] The grindability is evaluated according to the following criteria.

[0206] A: It can grind the SA surface of the back grinding belt without any problems.

[0207] B: The SA surface, which is difficult to grind on the back of the grinding belt.

[0208] C: The SA surface of the back grinding belt cannot be ground.

[0209] <Evaluation of Thickness Accuracy>

[0210] For the structure after its machinability has been evaluated, the side of the silicon wafer opposite to the circuit formation surface is ground using a wafer grinding apparatus (DISCO Corporation, product name: DGP 8760). Then, the back-side grinding tape is removed from the structure.

[0211] The difference between the maximum and minimum thickness of a silicon wafer is measured (TTV).

[0212] The following criteria will be used for evaluation.

[0213] A: TTV is below 5μm.

[0214] B: TTV is greater than 5μm.

[0215] Here, the evaluation of machinability can also be described as steps (A) and (B) in the manufacturing method of the electronic device implemented in this embodiment. Furthermore, the evaluation of thickness accuracy can also be described as steps (C) and (D) in the manufacturing method of the electronic device implemented in this embodiment.

[0216] It should be noted that in the [Measurement and Evaluation], for the back-side grinding belt formed by stacking resin layer (A) and resin layer (B) (i.e., Comparative Examples 1 to 3), the resin layer (A) side was used as the SA surface and the resin layer (B) side was used as the SB surface, and measurements and evaluations were performed separately.

[0217] The results of the measurement and evaluation are shown in Table 1.

[0218] [Table 1]

[0219]

[0220] According to Table 1, the evaluation results of the thickness accuracy of the back-side polishing tape in the embodiment are good. That is, it can be understood that the back-side polishing tape according to this embodiment can improve the thickness accuracy of the obtained electronic components.

[0221] Furthermore, the evaluation results of the machinability of the back-side grinding belt in the embodiment are good. That is, it can be understood that the back-side grinding belt according to this embodiment can improve the performance balance between belt machinability and the thickness accuracy of the obtained electronic components.

[0222] This application claims priority based on Japanese Patent Application No. 2023-202453, filed on November 30, 2023, the entire disclosure of which is incorporated herein by reference.

[0223] Explanation of reference numerals in the attached figures

[0224] 10. Resin layer (A)

[0225] 100 Backside Grinding Belt

[0226] SA back grinding belt SA surface

[0227] SB back grinding belt SB side

[0228] 200 silicon wafers

[0229] 300 Compression Disc Terminal

[0230] M-groove of silicon wafer M

[0231] H represents the deformation in the height direction of the portion where the shape of the groove M is transferred.

[0232] 400 Electronic Components

[0233] Circuit formation surface of 400A electronic components

[0234] 400B The side of the electronic component opposite to the circuit formation surface

[0235] 500 structure.

Claims

1. A back-side grinding belt that protects the circuit-forming surface of an electronic component during the grinding process. The back grinding belt has a resin layer (A). The resin constituting the resin layer (A) has a Vicat softening point of 45°C or higher. The embedment depth, as determined by method 1 below, is 10 μm or more. [Method 1] A silicon wafer with a groove M having a width of 50 μm and a depth of 70 μm is heated to 90°C. With the groove M in contact with one side (SB) of the back polishing tape, a 30N load is continuously applied for 30 seconds from the side (SA) of the back polishing tape opposite to the SB side, using a φ7mm compression disk terminal on a digital force gauge. After the load is continuously applied, the silicon wafer with the back polishing tape attached is cooled to 23°C, and then the back polishing tape is peeled off from the silicon wafer. The amount of deformation in the height direction of the portion of the back polishing tape with the shape of the groove M transferred is taken as the embedment amount.

2. The back-side grinding belt according to claim 1, wherein, The proportion of the resin layer (A) in the back grinding belt is 65% by volume or more.

3. The back-side grinding belt according to claim 1 or 2, wherein, The back abrasive belt is formed from a single layer of the resin layer (A).

4. The back-side grinding belt according to any one of claims 1 to 3, wherein, The density of the resin constituting the resin layer (A) is 880 kg / m³. 3 above.

5. The back-side grinding belt according to any one of claims 1 to 4, wherein, The resin constituting the resin layer (A) comprises at least one selected from the group consisting of ethylene-α-olefin copolymer, ethylene-vinyl ester copolymer, low-density polyethylene, polyvinyl chloride and propylene-α-olefin copolymer.

6. The back-side grinding belt according to any one of claims 1 to 5, wherein, The back abrasive belt does not contain an adhesive layer, or the back abrasive belt further contains an adhesive layer and the thickness of the adhesive layer is less than 10 μm.

7. The back-side grinding belt according to any one of claims 1 to 6, wherein, The thickness of the back abrasive belt is greater than 50 μm and less than 1000 μm.

8. The back-side grinding belt according to any one of claims 1 to 7, which can be used in a method of manufacturing an electronic device, the method of manufacturing an electronic device including a step of planarizing the surface of the back-side grinding belt before a step of grinding the electronic component.

9. A method for manufacturing an electronic device, comprising: Step (A): Prepare a structure, the structure having electronic components with a circuit forming surface and a back polishing tape, wherein the circuit forming surface of the electronic components is attached to one side of the back polishing tape, namely the SB side. Step (B) flattens the SA surface, the side opposite to the SB surface of the back grinding belt in the structure. Step (C), after step (B), involves grinding the surface of the electronic component opposite to the side where the circuit is formed; The back grinding belt has a resin layer (A). The resin constituting the resin layer (A) has a Vicat softening point of 45°C or higher. The embedment depth determined by method 2 below is 10 μm or more. [Method 2] A silicon wafer with a groove M having a width of 50 μm and a depth of 70 μm is heated to 90°C. With the groove M in contact with the SB surface of the back polishing tape, a 30N load is continuously applied for 30 seconds from the SA surface by setting a φ7mm compression disk terminal on a digital force gauge. After the load is continuously applied, the silicon wafer with the back polishing tape attached is cooled to 23°C, and then the back polishing tape is peeled off from the silicon wafer. The amount of deformation in the height direction of the portion of the back polishing tape with the shape of the groove M transferred is taken as the embedment amount.

10. The method of manufacturing an electronic device according to claim 9, wherein, After the process (C), there is also a process (D) to remove the back grinding belt from the structure.

11. The method of manufacturing an electronic device according to claim 9 or 10, wherein, The proportion of the resin layer (A) in the back grinding belt is 65% by volume or more.

12. The method for manufacturing an electronic device according to any one of claims 9 to 11, wherein, The back abrasive belt is formed from a single layer of the resin layer (A).

13. The method for manufacturing an electronic device according to any one of claims 9 to 12, wherein, The density of the resin constituting the resin layer (A) is 880 kg / m³. 3 above.

14. The method for manufacturing an electronic device according to any one of claims 9 to 13, wherein, The resin constituting the resin layer (A) comprises at least one selected from the group consisting of ethylene-α-olefin copolymer, ethylene-vinyl ester copolymer, low-density polyethylene, polyvinyl chloride and propylene-α-olefin copolymer.

15. The method for manufacturing an electronic device according to any one of claims 9 to 14, wherein, The back abrasive belt does not contain an adhesive layer, or the back abrasive belt further contains an adhesive layer and the thickness of the adhesive layer is less than 10 μm.

16. The method for manufacturing an electronic device according to any one of claims 9 to 15, wherein, The thickness of the back abrasive belt is greater than 50 μm and less than 1000 μm.

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