Manufacturing method for semiconductor devices

Abstract

A method for manufacturing a semiconductor device, the method including: a step for disposing an adhesive heat insulation material on a semiconductor device; a step for performing reflow of the semiconductor device on which the heat insulation material is disposed; and a step for separating the heat insulation material from the semiconductor device.

Description

[Technical Field]

[0001] This invention relates to a method for manufacturing a semiconductor device. [Background technology]

[0002] Non-volatile memory, characterized by low power consumption and high-speed read / write capabilities, is attracting attention as a next-generation memory technology. Examples include phase-change memory (PCM), magnetoresistive random-access memory (MRAM), and resistive random-access memory (ReRAM). However, non-volatile memory is sensitive to heat, and maintaining its quality when exposed to high-temperature environments during the reflow process for mounting remains a challenge.

[0003] To address this issue, for example, Patent Document 1 discloses a non-volatile semiconductor memory device comprising an MRAM chip and an enclosure that covers part or all of the MRAM chip and has an insulating region for preventing thermal fluctuations in the magnetization of the memory layer. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2014-36192 [Overview of the project] [Problems that the invention aims to solve]

[0005] The present invention aims to provide a novel method for protecting semiconductor devices from heat during the reflow process. [Means for solving the problem]

[0006] One aspect of the present invention is a method for manufacturing a semiconductor device, comprising the steps of: placing an adhesive heat insulating material on a semiconductor device; reflowing the semiconductor device on which the heat insulating material is placed; and peeling the heat insulating material off the semiconductor device.

[0007] In this manufacturing method, since the semiconductor device is subjected to a reflow process with the heat insulating material disposed, the semiconductor device can be protected from the heat in the reflow process. In addition, the semiconductor device disclosed in Patent Document 1 described above includes a heat insulating region as one of its components. Therefore, even after the reflow process, the device is in a state where it includes the heat insulating region, whereas in this manufacturing method, an adhesive heat insulating material is used and the heat insulating material is peeled off from the semiconductor device after the reflow process. The fact that the heat insulating material remains in the device even after the reflow process is not preferable from the viewpoints of miniaturization of the semiconductor device, improvement of the design freedom, etc. However, by peeling off the heat insulating material after the reflow process, such problems can be solved.

[0008] The heat insulating material may satisfy the following formula (A). F1>F2 …(A) In the formula, F1 represents the adhesive force of the heat insulating material after heating the heat insulating material at 220°C for 120 seconds, and F2 represents the adhesive force of the heat insulating material after heating the heat insulating material at 260°C for 30 seconds. F1 and F2 can be regarded as corresponding to the adhesive forces of the heat insulating material during and after the reflow process, respectively. That is, when the heat insulating material satisfies formula (A), during the reflow process, since the adhesive force of the heat insulating material is relatively large, the heat insulating material easily adheres to the semiconductor device, and the semiconductor device can be more suitably protected from heat. Also, after the reflow process, since the adhesive force of the heat insulating material is relatively small, the heat insulating material can be easily peeled off from the semiconductor device.

[0009] The heat insulating material may satisfy the following formula (B). F0≦F1 …(B) In the formula, F0 represents the adhesive force of the heat insulating material at 25°C, and F1 represents the adhesive force of the heat insulating material after heating the heat insulating material at 220°C for 120 seconds. F0 and F1 can be regarded as corresponding to the adhesive force of the heat insulating material before the reflow process (for example, the process of disposing the heat insulating material on the semiconductor device) and during the reflow process, respectively. That is, when the heat insulating material satisfies the formula (B), before the reflow process (for example, the process of disposing the heat insulating material on the semiconductor device), since the adhesive force of the heat insulating material is relatively small, the handling of the heat insulating material is easy, and during the reflow process, since the adhesive force of the heat insulating material is relatively large, the heat insulating material easily adheres to the semiconductor device, and the semiconductor device can be more suitably protected from heat.

[0010] The heat insulating material may contain a matrix polymer and thermally expandable hollow particles. In this case, when the thermally expandable hollow particles expand during the reflow process, the interfacial adhesion between the heat insulating material and the semiconductor device may decrease after the reflow process. Therefore, after the reflow process, the heat insulating material can be easily peeled off from the semiconductor device.

[0011] In the process of disposing the heat insulating material, a heat insulating material preformed into a sheet shape in advance may be disposed. In this case, when the area to which the heat insulating material is applied is large, the heat insulating material can be easily disposed collectively.

[0012] In the process of disposing the heat insulating material, after a liquid heat insulating material precursor is disposed on the semiconductor device, the heat insulating material precursor may be cured. By using the liquid heat insulating material precursor, the heat insulating material can be easily disposed even when the place where the heat insulating material should be disposed is narrow or has a complex shape.

Advantages of the Invention

[0013] According to the present invention, a novel method for protecting a semiconductor device from heat in a reflow process is provided.

Brief Description of the Drawings

[0014] [Figure 1] It is a schematic cross-sectional view showing an embodiment of the disposing process. [Figure 2] It is a schematic cross-sectional view showing another embodiment of the disposing process. [Figure 3]This is a schematic cross-sectional view showing another embodiment of the placement process. [Figure 4] This is a schematic cross-sectional view showing another embodiment of the placement process. [Modes for carrying out the invention]

[0015] One embodiment of the present invention is a method for manufacturing a semiconductor device, comprising a placement step of placing an adhesive heat insulating material on a semiconductor device, a reflow step of reflowing the semiconductor device on which the heat insulating material is placed, and a peeling step of peeling the heat insulating material off the semiconductor device.

[0016] Figure 1 is a schematic cross-sectional view showing one embodiment of the placement process. As shown in Figure 1, the semiconductor device (also called a semiconductor package) 1A used in the placement process includes, for example, a substrate 2, leads 4 connected to the substrate 2 with solder (solder paste) 3, and a semiconductor chip 6 connected to the leads 4 via wires 5. The semiconductor chip 6 is mounted on a die pad 8 via a die attach material 7 and covered with a sealing material 9.

[0017] The thermal insulation material is placed on at least a portion of the surface of such a semiconductor device 1A. In one embodiment, the thermal insulation material 10 is placed on the semiconductor device 1A so as to cover the entire surface of the sealing material 9. In another embodiment, the thermal insulation material 10 may be placed so as to cover only a portion of the surface of the sealing material 9 (for example, only the top surface).

[0018] Figure 2 is a schematic cross-sectional view showing another embodiment of the placement process. As shown in Figure 2, in another embodiment, the semiconductor device 11A used in the placement process includes, for example, a substrate 12, an interposer 14 connected to the substrate 12 by solder (solder balls) 13, and a semiconductor chip 16 connected to the interposer 14 via adhesive 15. The semiconductor chip 16 is connected to the interposer 14 by a plurality of protruding electrodes (bumps) 16a. The semiconductor chip 16 is covered with a encapsulating material 17 placed on the interposer 14.

[0019] The thermal insulation material is placed on at least a portion of the surface of such a semiconductor device 11A. In one embodiment, the thermal insulation material 18 is placed on the semiconductor device 11A so as to cover the entire surface of the encapsulant 17 and all of the sides where the solder (solder balls) 13 and interposer 14 are located.

[0020] In another embodiment of the arrangement process shown in Figure 2, the thermal insulation material 18 may be arranged to cover the entire surface of the encapsulant 17 and only the sides where the interposer 14 is located (it does not need to be placed on the sides where the solder (solder balls) 13 are located). In yet another embodiment, the thermal insulation material 18 may be arranged to cover only the entire surface of the encapsulant 17, or to cover only a portion of the surface of the encapsulant 17 (e.g., the top surface). Even in these cases, the semiconductor device can be suitably protected from the heat of the reflow process. However, for example, when low-temperature solder is used as the solder (solder balls) 13, the thermal insulation material 18 is preferably arranged to cover the entire surface of the encapsulant 17 and all the sides where the solder (solder balls) 13 and interposer 14 are located, as shown in Figure 2, from the viewpoint of protecting the solder (solder balls) 13 from excessive heat during the reflow process and suppressing damage at the solder joints.

[0021] In another embodiment, multiple semiconductor devices (semiconductor packages) may be mounted on a single substrate 2, 12, and some or all of these multiple semiconductor devices may be the semiconductor devices 1A, 11A described above. If some of the multiple semiconductor devices are the semiconductor devices 1A, 11A described above, the remaining semiconductor devices may be semiconductor devices that are more heat-resistant (have higher heat resistance) than the semiconductor devices 1A, 11A described above, and the solder on the remaining semiconductor devices may be solder that is joined at a higher temperature than the solders 3, 13 on the semiconductor devices 1A, 11A described above. In this way, even when multiple semiconductor devices (semiconductor packages) with different heat resistances are mounted on a single substrate 2, 12, by placing the heat insulating materials 10, 18 on the semiconductor devices 1A, 11A that are less heat-resistant (have lower heat resistance), multiple semiconductor devices (semiconductor packages) with different heat resistances can be subjected to the reflow process all at once.

[0022] In another embodiment, the insulating material may also be placed on the side of the substrate opposite to the side on which the semiconductor chip is mounted. Figure 3 is a schematic cross-sectional view showing another embodiment of the placement process shown in Figure 1. As shown in Figure 3, the insulating material 10 is also placed on the side of the substrate 2 opposite to the side on which the semiconductor chip 6 is mounted. Figure 4 is a schematic cross-sectional view showing another embodiment of the placement process shown in Figure 2. As shown in Figure 4, the insulating material 18 is also placed on the side of the substrate 12 opposite to the side on which the semiconductor chip 16 is mounted. In these embodiments, for example, when multiple semiconductor devices (semiconductor packages) with different heat resistances are mounted on a single substrate 2, 12, by placing more insulating material 10, 18 on the semiconductor devices 1B, 11B that are more susceptible to heat (have lower heat resistance), multiple semiconductor devices (semiconductor packages) with different heat resistances can be subjected to the reflow process all at once.

[0023] The thermal insulation material is not particularly limited as long as it has the desired thermal insulation performance. Preferably, the thermal insulation material is one that satisfies the following formula (A). F1 > F2 …(A) In the formula, F1 represents the adhesive strength of the insulation material after heating it at 220°C for 120 seconds, and F2 represents the adhesive strength of the insulation material after heating it at 260°C for 30 seconds.

[0024] More specifically, F1 refers to the adhesive strength measured using a tensile testing machine (e.g., Shimadzu Corporation's "EZ Test EZ-S") under the conditions of 90° peel and tensile speed: 50 mm / min. This is achieved by attaching the unheated insulating material to a glass slide at 25°C, letting it stand for 15 minutes, then heating it at 220°C for 120 seconds and cooling it to 25°C. F2 refers to the adhesive strength measured in the same manner as above for the insulating material that was attached to a glass slide at 25°C, letting it stand for 15 minutes, then heating it at 260°C for 30 seconds and cooling it to 25°C.

[0025] In equation (A), F1 and F2 can be seen as corresponding to the adhesive strength of the insulating material during and after the reflow process, respectively. That is, when the insulating material satisfies equation (A), during the reflow process, the adhesive strength of the insulating material is relatively high, so the insulating material adheres easily to the semiconductor device, and the semiconductor device can be more effectively protected from heat. After the reflow process, the adhesive strength of the insulating material is relatively low, so the insulating material can be easily peeled off the semiconductor device.

[0026] The thermal insulation material is preferably one that satisfies the following formula (B). F0 ≤ F1 …(B) In the formula, F0 represents the adhesive strength of the insulating material at 25°C, and F1 represents the adhesive strength of the insulating material after heating it at 220°C for 120 seconds.

[0027] More specifically, F0 refers to the adhesive strength measured at 25°C after attaching an unheated insulating material to a glass slide and letting it stand for 15 minutes, followed by measurement in the same manner as described above. An insulating material is considered to be adhesive if its F0 is 10 N / m or higher.

[0028] In equation (B), F0 and F1 can be seen as corresponding to the adhesive strength of the insulating material before the reflow process (for example, the process of placing the insulating material on the semiconductor device) and during the reflow process, respectively. That is, if the insulating material satisfies equation (B), before the reflow process (for example, the process of placing the insulating material on the semiconductor device), the adhesive strength of the insulating material is relatively small, making it easy to handle, and during the reflow process, the adhesive strength of the insulating material is relatively large, making it easier for the insulating material to adhere to the semiconductor device, thus providing better protection of the semiconductor device from heat.

[0029] From the same viewpoint as described above, the thermal insulation material is more preferably a thermal insulation material that satisfies both formula (A) and formula (B) above.

[0030] A thermal insulation material having the adhesive properties described above may contain, for example, a matrix polymer and hollow particles. The thermal insulation material may be a cured product obtained by curing (polymerizing the monomers in the precursor) a thermal insulation material precursor containing monomer components constituting the monomer units of the matrix polymer and hollow particles.

[0031] In the placement process, in one embodiment, a pre-formed sheet-shaped (pre-cured) thermal insulation material may be placed. The method for placing the pre-formed sheet-shaped thermal insulation material may include a pressing process in which the thermal insulation material is pressed onto the semiconductor device (semiconductor package) under vacuum or atmospheric pressure.

[0032] In the pressing process, specifically, for example, first, a buffer material (e.g., a rubber sheet), a release film, a semiconductor device (semiconductor package), a heat insulating material, and a release film are stacked in this order inside the chamber of a vacuum laminator (e.g., "V-130" manufactured by Nichco Materials Co., Ltd.). Subsequently, after evacuating the inside of the chamber, pressure is applied so that the heat insulating material adheres closely to the semiconductor device (semiconductor package), whereby the heat insulating material can be pressed onto the semiconductor device (semiconductor package). As another specific example, first, a semiconductor device (semiconductor package), a heat insulating material, and a release film are stacked in this order on a support (e.g., a stainless steel plate). Subsequently, it is inserted into a roll laminator (e.g., "VA-770H Special Type Laminator" manufactured by Daisheng Laminator Co., Ltd.), and pressure is applied so that the heat insulating material adheres closely to the semiconductor device (semiconductor package), whereby the heat insulating material can be pressed onto the semiconductor device (semiconductor package).

[0033] In the placement process, in another embodiment, a liquid heat insulating material precursor may be placed on the semiconductor device, and then the heat insulating material may be placed by curing the heat insulating material precursor.

[0034] The monomer component may contain a compound represented by the following formula (1) from the viewpoint that the heat insulating material has low elasticity and excellent elongation and can enhance the followability to the semiconductor device.

Chemical formula

[0035] , , , 12 , 12 , 11 , 12 , 11 , 13 , 11 , , 11 , , 12 , , and R 12 each independently represents a hydrogen atom or a methyl group, and R 13 represents a divalent group having a polyoxyalkylene chain.

[0035] In one embodiment, one of R 11 and R 12 may be a hydrogen atom and the other may be a methyl group. In another embodiment, both of R 11 and R 12 may be hydrogen atoms. In other embodiments, both of R 11 and R 12 may be methyl groups.

[0036] In one embodiment, the polyoxyalkylene chain includes a structural unit represented by the following formula (2). This makes it possible to increase the strength of the thermal insulation material while suppressing an excessive increase in the viscosity of the thermal insulation material precursor. [ka]

[0037] In this case, R 13 The group may be a divalent group having a polyoxyethylene chain, and the compound represented by formula (1) is preferably a compound represented by the following formulas (1-2) (polyethylene glycol di(meth)acrylate). [ka] In formula (1-2), R 11 and R 12 R in equation (1) 11 and R 12 These are synonymous, and m is an integer greater than or equal to 2.

[0038] In another embodiment, the polyoxyalkylene chain includes a structural unit represented by the following formula (3). This facilitates the handling of the thermal insulation precursor. [ka]

[0039] In this case, R 13 The group may be a divalent group having a polyoxypropylene chain, and the compound represented by formula (1) is preferably a compound represented by the following formulas (1-3) (polypropylene glycol di(meth)acrylate). [ka] In formula (1-3), R 11 and R 12 R in equation (1) 11 and R 12These are equivalent to the above, and n is an integer greater than or equal to 2.

[0040] In another embodiment, the polyoxyalkylene chain is preferably a copolymer chain containing the structural units represented by formula (2) and formula (3) described above, from the viewpoint of easily achieving both the strength of the thermal insulation material of the compound represented by formula (1) and the handling of the thermal insulation material precursor. The copolymer chain may be an alternating copolymer chain, a block copolymer chain, or a random copolymer chain. The copolymer chain is preferably a random copolymer chain from the viewpoint of further lowering the crystallinity of the compound represented by formula (1) and further facilitating the handling of the thermal insulation material precursor.

[0041] In each of the embodiments described above, the polyoxyalkylene chain may have, in addition to the structural units represented by formula (2) and formula (3), oxyalkylene groups having 4 to 5 carbon atoms, such as oxytetramethylene groups, oxybutylene groups, and oxypentylene groups, as structural units.

[0042] R 13 In addition to the polyoxyalkylene chain described above, the group may be a divalent group further having other organic groups. The other organic groups may be chain-like groups other than the polyoxyalkylene chain, such as a methylene chain (a chain with -CH2- as a structural unit), a polyester chain (a chain containing -COO- as a structural unit), a polyurethane chain (a chain containing -OCON- as a structural unit), etc.

[0043] For example, the compound represented by formula (1) may also be a compound represented by the following formulas (1-4). [ka] In formula (1-4), R 11 and R 12 R in equation (1) 11 and R 12 These are synonymous, and R 14 and R 15Each of these is an alkylene group having 2 to 5 carbon atoms, and k1, k2, and k3 are each independent integers of 2 or more. k2 may be an integer of 16 or less, for example.

[0044] Multiple Rs exist 14 and R 15 Each of them may be identical to the others, or they may be different to each other. There are multiple R's. 14 and R 15 Each preferably contains an ethylene group and a propylene group. That is, (R 14 O) k1 Polyoxyalkylene chains represented by (R 15 O) k3 The polyoxyalkylene chains represented by are preferably copolymer chains containing an oxyethylene group (structural unit represented by formula (2) above) and an oxypropylene group (structural unit represented by formula (3) above).

[0045] In each of the embodiments described above, the number of oxyalkylene groups in the polyoxyalkylene chain is preferably 100 or more. When the number of oxyalkylene groups in the polyoxyalkylene chain is 100 or more, the main chain of the compound represented by formula (1) becomes longer, which further improves the elongation of the thermal insulation material and increases its strength. The number of oxyalkylene groups corresponds to m in formula (1-2), n in formula (1-3), and k1 and k3 in formula (1-4), respectively.

[0046] The number of oxyalkylene groups in the polyoxyalkylene chain is more preferably 130 or more, 180 or more, 200 or more, 220 or more, 250 or more, 270 or more, 300 or more, or 320 or more. The number of oxyalkylene groups in the polyoxyalkylene chain may be 600 or less, 570 or less, or 530 or less.

[0047] The weight-average molecular weight of the compound represented by formula (1) is preferably 5000 or more, 6000 or more, 7000 or more, 8000 or more, 9000 or more, 10000 or more, 11000 or more, 12000 or more, 13000 or more, 14000 or more, or 15000 or more, from the viewpoint of the thermal insulation material having lower elasticity and superior elongation. The weight-average molecular weight of the compound represented by formula (1) is preferably 100000 or less, 80000 or less, 60000 or less, 34000 or less, 31000 or less, or 28000 or less, from the viewpoint of making it easier to adjust the viscosity of the thermal insulation material precursor.

[0048] The compound represented by formula (1) may be liquid at 25°C. In this case, the viscosity of the compound represented by formula (1) at 25°C is preferably 1000 Pa·s or less, 800 Pa·s or less, 600 Pa·s or less, 500 Pa·s or less, 350 Pa·s or less, 300 Pa·s or less, or 200 Pa·s or less, from the viewpoint of facilitating application to the coating surface and improving adhesion of the heat insulating material to the coating surface. The viscosity of the compound represented by formula (1) at 25°C may be 0.1 Pa·s or more, 0.2 Pa·s or more, 0.3 Pa·s or more, 1 Pa·s or more, 2 Pa·s or more, or 3 Pa·s or more.

[0049] The compound represented by formula (1) may be solid at 25°C. In this case, from the viewpoint of further improving the handling of the thermal insulation precursor, the compound represented by formula (1) is preferably liquid at 50°C. In this case, from the viewpoint of further improving the handling of the thermal insulation precursor, the viscosity of the compound represented by formula (1) at 50°C is preferably 100 Pa·s or less, more preferably 50 Pa·s or less, even more preferably 30 Pa·s or less, and particularly preferably 20 Pa·s or less. The viscosity of the compound represented by formula (1) at 50°C may be 0.1 Pa·s or more, 0.2 Pa·s or more, or 0.3 Pa·s or more.

[0050] Viscosity refers to the value measured according to JIS Z 8803, specifically the value measured using an E-type viscometer (for example, PE-80L manufactured by Toki Sangyo Co., Ltd.). The viscometer can be calibrated according to JIS Z 8809-JS14000. The viscosity of the compound represented by formula (1) can be adjusted by adjusting the weight-average molecular weight of the compound.

[0051] From the viewpoint of the thermal insulation material having lower elasticity and superior elongation, the content of the compound represented by formula (1) is preferably 10% by mass or more, 20% by mass or more, 30% by mass or more, or 40% by mass or more, based on the total amount of the thermal insulation material precursor. The content of the compound represented by formula (1) may be 90% by mass or less, 80% by mass or less, 70% by mass or less, 60% by mass or less, or 50% by mass or less, based on the total amount of the thermal insulation material precursor.

[0052] From the viewpoint of the thermal insulation material having lower elasticity and superior elongation, the content of the compound represented by formula (1) is preferably 20 parts by mass or more, 30 parts by mass or more, or 40 parts by mass or more, per 100 parts by mass of the total monomer components. The content of the compound represented by formula (1) may be 80 parts by mass or less, 70 parts by mass or less, or 60 parts by mass or less, per 100 parts by mass of the total monomer components.

[0053] The monomer component may further contain other monomers copolymerizable with the compound represented by formula (1) described above, for purposes such as adjusting the physical properties of the thermal insulation precursor.

[0054] Other monomers may be, for example, compounds having one (meth)acryloyl group. Such compounds may be, for example, alkyl (meth)acrylates. Other monomers may be compounds having, in addition to one (meth)acryloyl group, an aromatic hydrocarbon group, a group containing a polyoxyalkylene chain, a group containing a heterocyclic group, an alkoxy group, a phenoxy group, a group containing a silane group, a group containing a siloxane bond, a halogen atom, a hydroxyl group, a carboxyl group, an amino group, or an epoxy group. In particular, the viscosity of the insulating material precursor can be adjusted by including an alkyl (meth)acrylate in the insulating material precursor. Furthermore, the adhesion of the insulating material precursor and the insulating material to the component can be further improved by including a compound having, in addition to a (meth)acryloyl group, a hydroxyl group, a carboxyl group, an amino group, or an epoxy group in the insulating material precursor.

[0055] The alkyl group (the alkyl group portion other than the (meth)acryloyl group) in alkyl (meth)acrylate may be linear, branched, or alicyclic. The number of carbon atoms in the alkyl group may be, for example, 1 to 30. The number of carbon atoms in the alkyl group may be 1 to 11, 1 to 8, 1 to 6, or 1 to 4, and may also be 12 to 30, 12 to 28, 12 to 24, 12 to 22, 12 to 18, or 12 to 14.

[0056] Examples of alkyl(meth)acrylates having a linear alkyl group include methyl(meth)acrylate, ethyl(meth)acrylate, propyl(meth)acrylate, butyl(meth)acrylate, pentyl(meth)acrylate, n-hexyl(meth)acrylate, n-heptyl(meth)acrylate, octyl(meth)acrylate, nonyl(meth)acrylate, decyl(meth)acrylate, or undecyl(meth)acrylate, which are alkyl(meth)acrylates having a linear alkyl group with 1 to 11 carbon atoms. Examples of alkyl(meth)acrylates having a linear alkyl group with 12 to 30 carbon atoms include syl(meth)acrylate (lauryl(meth)acrylate), tetradecyl(meth)acrylate, hexadecyl(meth)acrylate (cetyl(meth)acrylate), octadecyl(meth)acrylate (stearyl(meth)acrylate), docosyl(meth)acrylate (behenyl(meth)acrylate), tetracosyl(meth)acrylate, hexacosyl(meth)acrylate, and octacosyl(meth)acrylate.

[0057] Examples of alkyl(meth)acrylates having branched alkyl groups include s-butyl(meth)acrylate, t-butyl(meth)acrylate, isobutyl(meth)acrylate, isopentyl(meth)acrylate, isoamyl(meth)acrylate, isooctyl(meth)acrylate, 2-ethylhexyl(meth)acrylate, isononyl(meth)acrylate, isodecyl(meth)acrylate, and other alkyl(meth)acrylates having branched alkyl groups with 1 to 11 carbon atoms, as well as isomiristyl Examples of alkyl(meth)acrylates having branched alkyl groups with 12 to 30 carbon atoms include 12-30 carbon atoms, such as 14-(meth)acrylate, 2-propylheptyl(meth)acrylate, isoundecyl(meth)acrylate, isododecyl(meth)acrylate, isotridecyl(meth)acrylate, isopentadecyl(meth)acrylate, isohexadecyl(meth)acrylate, isoheptadecyl(meth)acrylate, isostearyl(meth)acrylate, and decyltetradecanyl(meth)acrylate.

[0058] Examples of alkyl (meth)acrylates having an alicyclic alkyl group (cycloalkyl group) include cyclohexyl (meth)acrylate, 3,3,5-trimethylcyclohexyl (meth)acrylate, isobornyl (meth)acrylate, terpene (meth)acrylate, and dicyclopentanyl (meth)acrylate.

[0059] Examples of compounds having a (meth)acryloyl group and an aromatic hydrocarbon group include benzyl (meth)acrylate.

[0060] Examples of compounds having a (meth)acryloyl group and a group containing a polyoxyalkylene chain include polyethylene glycol (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, polypropylene glycol (meth)acrylate, methoxypolypropylene glycol (meth)acrylate, polybutylene glycol (meth)acrylate, and methoxypolybutylene glycol (meth)acrylate.

[0061] Examples of compounds having a (meth)acryloyl group and a heterocyclic group include tetrahydrofurfuryl (meth)acrylate.

[0062] Examples of compounds having a (meth)acryloyl group and an alkoxy group include 2-methoxyethyl acrylate.

[0063] Examples of compounds having a (meth)acryloyl group and a phenoxy group include phenoxyethyl (meth)acrylate.

[0064] Examples of compounds having groups containing a (meth)acryloyl group and a silane group include 3-acryloxypropyltriethoxysilane, 10-methacryloyloxydecyltrimethoxysilane, 10-acryloyloxydecyltrimethoxysilane, 10-methacryloyloxydecyltriethoxysilane, and 10-acryloyloxydecyltriethoxysilane.

[0065] Examples of compounds having a (meth)acryloyl group and a group containing a siloxane bond include silicone (meth)acrylates.

[0066] Compounds having a (meth)acryloyl group and a halogen atom include trifluoromethyl (meth)acrylate, 2,2,2-trifluoroethyl (meth)acrylate, 1,1,1,3,3,3-hexafluoro-2-propyl (meth)acrylate, perfluoroethylmethyl (meth)acrylate, perfluoropropylmethyl (meth)acrylate, perfluorobutylmethyl (meth)acrylate, perfluoropentylmethyl (meth)acrylate, perfluorohexylmethyl (meth)acrylate, perfluoroheptylmethyl (meth)acrylate, perfluorooctylmethyl (meth)acrylate, perfluorononylmethyl (meth)acrylate, perfluorodecylmethyl (meth)acrylate, perfluoroundecylmethyl (meth)acrylate, perfluorododecylmethyl (meth)acrylate, perfluoro Examples include (meth)acrylates containing a fluorine atom, such as tridecylmethyl (meth)acrylate, perfluorotetradecylmethyl (meth)acrylate, 2-(trifluoromethyl)ethyl (meth)acrylate, 2-(perfluoroethyl)ethyl (meth)acrylate, 2-(perfluoropropyl)ethyl (meth)acrylate, 2-(perfluorobutyl)ethyl (meth)acrylate, 2-(perfluoropentyl)ethyl (meth)acrylate, 2-(perfluorohexyl)ethyl (meth)acrylate, 2-(perfluoroheptyl)ethyl (meth)acrylate, 2-(perfluorooctyl)ethyl (meth)acrylate, 2-(perfluorononyl)ethyl (meth)acrylate, 2-(perfluorotridecyl)ethyl (meth)acrylate, and 2-(perfluorotetradecyl)ethyl (meth)acrylate.

[0067] Examples of compounds having a (meth)acryloyl group and a hydroxyl group include hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, and 12-hydroxylauryl (meth)acrylate; and hydroxyalkylcycloalkane (meth)acrylates such as (4-hydroxymethylcyclohexyl)methyl (meth)acrylate.

[0068] Examples of compounds having a (meth)acryloyl group and a carboxyl group include (meth)acrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, monohydroxyethyl phthalate acrylate (e.g., "Aronics M5400" manufactured by Toagosei Co., Ltd.), and 2-acryloyloxyethyl succinate (e.g., "NK Ester A-SA" manufactured by Shin Nakamura Chemical Co., Ltd.).

[0069] Examples of compounds having a (meth)acryloyl group and an amino group include N,N-dimethylaminoethyl (meth)acrylate, N,N-diethylaminoethyl (meth)acrylate, N,N-dimethylaminopropyl (meth)acrylate, and N,N-diethylaminopropyl (meth)acrylate.

[0070] Examples of compounds having a (meth)acryloyl group and an epoxy group include glycidyl (meth)acrylate, α-ethyl(meth)acrylate, α-n-propyl(meth)acrylate, α-n-butyl(meth)acrylate, glycidyl (meth)acrylate, 3,4-epoxybutyl (meth)acrylate, 4,5-epoxypentyl (meth)acrylate, 6,7-epoxyheptyl (meth)acrylate, α-ethyl(meth)acrylate, 6,7-epoxyheptyl (meth)acrylate, 3-methyl-3,4-epoxybutyl (meth)acrylate, 4-methyl-4,5-epoxypentyl (meth)acrylate, 5-methyl-5,6-epoxyhexyl (meth)acrylate, β-methylglycidyl (meth)acrylate, and α-ethyl(meth)acrylate-β-methylglycidyl.

[0071] The monomer component may contain one of the other monomers listed above, or it may contain two or more.

[0072] The content of other monomers may be, for example, 1% by mass or more, 5% by mass or more, 10% by mass or more, 20% by mass or more, or 30% by mass or more, based on the total amount of the insulating material precursor, and may be 60% by mass or less, 50% by mass or less, or 40% by mass or less.

[0073] The thermal insulation material and thermal insulation material precursor preferably contain hollow particles, which are thermally expandable hollow particles (hereinafter also referred to as "first hollow particles"). The first hollow particles have an outer shell and a hollow portion. In this specification, thermally expandable hollow particles are hollow particles whose maximum volume expansion ratio with respect to volume at 25°C is 10 times or more. When the first hollow particles are used, in the reflow process, the first hollow particles expand due to heat, reducing the adhesion area at the interface between the thermal insulation material and the semiconductor device, and the thermal insulation material can be easily removed after the reflow process.

[0074] The maximum volume expansion ratio of the first hollow particle is measured by thermomechanical analysis (TMA) as the ratio of the maximum volume of the first hollow particle to its volume at 25°C (maximum volume / volume at 25°C) when heated at a heating rate of 10°C / min. The maximum volume expansion ratio of the first hollow particle may be, for example, 20 times or more, 30 times or more, or 40 times or more, or 120 times or less.

[0075] The outer shell of the first hollow particle is preferably made of a thermoplastic polymer. In this case, since the outer shell softens when heated, even if the liquid contained in the hollow part vaporizes and the internal pressure increases, the hollow particle is less likely to crack and expands easily. The thermoplastic polymer may be, for example, a polymer containing acrylonitrile, vinylidene chloride, etc. as monomer units. The thickness of the outer shell may be 2 μm or more and 15 μm or less.

[0076] The hollow portion of the first hollow particle contains, for example, a liquid. The first hollow particle is in this state under normal temperature and pressure (for example, at least atmospheric pressure and 30°C). The liquid is appropriately selected, for example, according to the heating temperature in the reflow process. The liquid is, for example, a liquid that vaporizes at a temperature below the maximum heating temperature in the reflow process. The liquid may be, for example, a hydrocarbon with a boiling point (at atmospheric pressure) of 50°C or higher, 100°C or higher, 150°C or higher, or 200°C or higher. In addition to the above liquid, the hollow portion of the first hollow particle may further contain a gas.

[0077] Examples of components contained within the hollow portion of the first hollow particle include hydrocarbons such as propane, propylene, butene, n-butane, isobutane, n-pentane, isopentane, neopentane, n-hexane, isohexane, heptane, isooctane, n-octane, isoalkanes (10-13 carbon atoms), and petroleum ether; low-boiling point compounds such as methane halides and tetraalkylsilanes; and compounds that gasify by thermal decomposition, such as azodicarbonamides.

[0078] The average particle diameter of the first hollow particle may be 5 μm or more, 10 μm or more, or 20 μm or more, and may be 50 μm or less, 40 μm or less, or 30 μm or less. The average particle diameter of the first hollow particle is measured by laser diffraction / scattering (for example, using Shimadzu Corporation's "SALD-7500nano").

[0079] From the viewpoint of making the composition more suitable for use as an insulating material in a reflow process (generally heated to 260°C), the expansion initiation temperature of the first hollow particles is preferably 70°C or higher, 100°C or higher, 130°C or higher, or 160°C or higher, and preferably 260°C or lower. The expansion initiation temperature of the first hollow particles is determined by thermomechanical analysis (TMA) at the temperature (horizontal axis)-volume change (vertical axis) profile when the temperature is raised at a heating rate of 10°C / min. The temperature at which the tangent line at the point where a volume change of 3 times or more / 5°C occurs intersects with the straight line (horizontal axis) where the volume change is zero (initial volume).

[0080] The maximum expansion temperature of the first hollow particle is preferably 100°C or higher, 150°C or higher, 200°C or higher, or 220°C or higher, and preferably 290°C or lower, 280°C or lower, or 270°C or lower. The maximum expansion temperature of the first hollow particle means the temperature at which the first hollow particle exhibits the maximum volume expansion ratio described above.

[0081] The content of the first hollow particles is preferably 1% by mass or more, more preferably 5% by mass or more, and even more preferably 8% by mass or more, and may be 20% by mass or less, or 15% by mass or less, based on the total mass of the thermal insulation material (thermal insulation material precursor), from the viewpoint of further facilitating peeling in the peeling process.

[0082] The content of the first hollow particles is preferably 1 volume% or more, more preferably 2 volume% or more, even more preferably 3 volume% or more, and particularly preferably 4 volume% or more, based on the total volume of the thermal insulation material (thermal insulation material precursor), from the viewpoint of further facilitating peeling in the peeling process. For example, it may be 10 volume% or less, 7 volume% or less, or 5 volume% or less.

[0083] The thermal insulation material (thermal insulation precursor) may further contain hollow particles other than the first hollow particles (hereinafter also referred to as "second hollow particles") from the viewpoint of further improving thermal insulation performance. The second hollow particles have an outer shell and a hollow portion. That is, the second hollow particles are hollow particles whose maximum volume expansion ratio with respect to volume at 25°C is less than 10 times. The maximum volume expansion ratio of the second hollow particles is measured in the same way as the maximum volume expansion ratio of the first hollow particles.

[0084] The outer shell of the second hollow particle may be composed of a polymer or an inorganic material. The outer shell is preferably composed of a polymer, and more preferably a thermoplastic polymer. In this case, the hollow particle is less likely to crack even when pressurized, can maintain its hollow structure, and can maintain its heat insulation properties. The thermoplastic polymer may be, for example, a polymer containing acrylonitrile, vinylidene chloride, etc. as monomer units. The inorganic material may be, for example, an inorganic glass such as borosilicate glass (sodium borosilicate glass, etc.), aluminosilicate glass, or glass made by compounding these. The thickness of the outer shell may be 0.005 μm or more, and may be 15 μm or less.

[0085] The hollow portion of the second hollow particle contains, for example, a gas. The second hollow particle is in this state under normal temperature and pressure conditions (for example, at least atmospheric pressure and 30°C). In addition to the gas, the hollow portion of the second hollow particle may also contain a liquid.

[0086] Examples of components enclosed within the hollow space of the second hollow particle include hydrocarbons such as propane, propylene, butene, n-butane, isobutane, n-pentane, isopentane, neopentane, n-hexane, isohexane, heptane, isooctane, n-octane, isoalkanes (10-13 carbon atoms), and petroleum ether; low-boiling point compounds such as methane halides and tetraalkylsilanes; and decomposition products of compounds that gasify by thermal decomposition, such as azodicarbonamides. Alternatively, the component enclosed within the hollow space of the second hollow particle may be air.

[0087] The average particle diameter of the second hollow particle is preferably 150 μm or less, more preferably 120 μm or less, and even more preferably 100 μm or less, and may be, for example, 5 μm or more, 10 μm or more, 20 μm or more, or 30 μm or more. The average particle diameter of the second hollow particle is measured by laser diffraction / scattering (for example, using "SALD-7500nano" manufactured by Shimadzu Corporation).

[0088] The density of the second hollow particle is 500 kg / m³. 3 Below 300kg / m 3 Below 100kg / m 3 Below 50kg / m 3 The following, or 40 kg / m 3 The following is acceptable: 10 kg / m 3 or more, or 20 kg / m 3 The above may suffice. In this specification, the density of the second hollow particle refers to the density measured by the tapping density method. That is, the second hollow particle (approximately 5 g) is placed in a 10 mL graduated cylinder, tapped 50 times, and the volume when the top surface is stable is taken as the stable volume, and the density is calculated by the following formula. Density = Initial input amount (kg) / Stable volume (m³) 3 )

[0089] From the viewpoint of further enhancing thermal insulation, the content of the second hollow particle is preferably 1% by mass or more, more preferably 3% by mass or more, and even more preferably 5% by mass or more, and may be, for example, 20% by mass or less, based on the total mass of the thermal insulation material (thermal insulation material precursor).

[0090] From the viewpoint of further enhancing thermal insulation, the content of the second type of hollow particle is preferably 50% by volume or more, more preferably 60% by volume or more, and may be, for example, 95% by volume or less, based on the total volume of the thermal insulation material (thermal insulation material precursor).

[0091] The total content of hollow particles (including the content of the first and second hollow particles) may be, for example, 5% by mass or more, 10% by mass or more, or 15% by mass or more, and may be 40% by mass or less, 30% by mass or less, or 20% by mass or less, based on the total amount of thermal insulation material (thermal insulation material precursor).

[0092] The total content of hollow particles (including the content of the first and second hollow particles) may be, for example, 50% or more, 60% or more, or 70% or more, and 95% or less, based on the total volume of the thermal insulation material (thermal insulation material precursor).

[0093] The thermal insulation precursor may further contain a polymerization initiator. The polymerization initiator may be, for example, a thermal polymerization initiator that generates radicals by heat, or a photopolymerization initiator that generates radicals by light. The polymerization initiator is preferably a thermal polymerization initiator.

[0094] If the thermal insulation precursor contains a thermal polymerization initiator, the thermal insulation material can be obtained by curing the precursor by applying heat to it during the arrangement step. In this case, the thermal insulation precursor may be one that is cured by heating at preferably 105°C or higher, more preferably 110°C or higher, and even more preferably 115°C or higher, and may also be one that is cured by heating at, for example, 200°C or lower, 190°C or lower, or 180°C or lower. The heating time when heating the thermal insulation precursor may be appropriately selected according to the composition of the thermal insulation precursor so that the thermal insulation precursor is suitably cured.

[0095] Examples of thermal polymerization initiators include azo compounds such as azobisisobutyronitrile, azobis-4-methoxy-2,4-dimethylvaleronitrile, azobiscyclohexanone-1-carbonitride, and azodibenzoyl; and organic peroxides such as benzoyl peroxide, lauroyl peroxide, di-t-butyl peroxide, di-t-hexyl peroxide, di-t-butyl peroxyhexahydroterephthalate, t-butyl peroxy-2-ethylhexanoate, 1,1-t-butyl peroxy-3,3,5-trimethylcyclohexane, and t-butylperoxyisopropyl carbonate. These thermal polymerization initiators may be used individually or in combination of two or more.

[0096] If the thermal insulation precursor contains a photopolymerization initiator, for example, the thermal insulation material can be obtained by curing the precursor by irradiating it with light (for example, light containing at least a portion of the wavelengths between 200 and 400 nm (ultraviolet light)) during the arrangement process. The conditions for light irradiation may be set appropriately depending on the type of photopolymerization initiator.

[0097] The photopolymerization initiator may be, for example, a benzoin ether-based photopolymerization initiator, an acetophenone-based photopolymerization initiator, an α-ketol-based photopolymerization initiator, an aromatic sulfonyl chloride-based photopolymerization initiator, a photoactive oxime-based photopolymerization initiator, a benzoin-based photopolymerization initiator, a benzyl-based photopolymerization initiator, a benzophenone-based photopolymerization initiator, a ketal-based photopolymerization initiator, a thioxanthone-based photopolymerization initiator, an acylphosphine oxide-based photopolymerization initiator, or the like.

[0098] Examples of benzoin ether-based photopolymerization initiators include benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2,2-dimethoxy-1,2-diphenylethane-1-one (e.g., BASF's "Irgacure 651"), and anisole methyl ether. Examples of acetophenone-based photopolymerization initiators include 1-hydroxycyclohexyl phenyl ketone (e.g., BASF's "Irgacure 184"), 4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one (e.g., BASF's "Irgacure 2959"), 2-hydroxy-2-methyl-1-phenyl-propan-1-one (e.g., BASF's "Irgacure 1173"), and methoxyacetophenone.

[0099] Examples of α-ketol-based photopolymerization initiators include 2-methyl-2-hydroxypropiophenone and 1-[4-(2-hydroxyethyl)-phenyl]-2-hydroxy-2-methylpropan-1-one. Examples of aromatic sulfonyl chloride-based photopolymerization initiators include 2-naphthalenesulfonyl chloride. Examples of photoactive oxime-based photopolymerization initiators include 1-phenyl-1,1-propanedione-2-(o-ethoxycarbonyl)-oxime.

[0100] Examples of benzoin-based photopolymerization initiators include benzoin. Examples of benzyl-based photopolymerization initiators include benzyl. Examples of benzophenone-based photopolymerization initiators include benzophenone, benzoylbenzoic acid, 3,3'-dimethyl-4-methoxybenzophenone, polyvinylbenzophenone, α-hydroxycyclohexylphenyl ketone. Examples of ketal-based photopolymerization initiators include benzyldimethylketal. Examples of thioxanthone-based photopolymerization initiators include thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone, 2,4-diethylthioxanthone, isopropylthioxanthone, 2,4-diisopropylthioxanthone, dodecylthioxanthone, etc.

[0101] Examples of acylphosphine-based photopolymerization initiators include bis(2,6-dimethoxybenzoyl)phenylphosphine oxide, bis(2,6-dimethoxybenzoyl)(2,4,4-trimethylpentyl)phosphine oxide, bis(2,6-dimethoxybenzoyl)-n-butylphosphine oxide, bis(2,6-dimethoxybenzoyl)-(2-methylpropan-1-yl)phosphine oxide, bis(2,6-dimethoxybenzoyl)-(1-methylpropan-1-yl)phosphine oxide, and bis(2,6-dimethoxybenzoyl)-t-butylphosphine oxide. Tylphosphine oxide, bis(2,6-dimethoxybenzoyl)cyclohexylphosphine oxide, bis(2,6-dimethoxybenzoyl)octylphosphine oxide, bis(2-methoxybenzoyl)(2-methylpropan-1-yl)phosphine oxide, bis(2-methoxybenzoyl)(1-methylpropan-1-yl)phosphine oxide, bis(2,6-diethoxybenzoyl)(2-methylpropan-1-yl)phosphine oxide, bis(2,6-diethoxybenzoyl)(1-methylpropan-1-yl)phosphine Oxide, bis(2,6-dibutoxybenzoyl)(2-methylpropan-1-yl)phosphine oxide, bis(2,4-dimethoxybenzoyl)(2-methylpropan-1-yl)phosphine oxide, bis(2,4,6-trimethylbenzoyl)(2,4-dipentoxyphenyl)phosphine oxide, bis(2,6-dimethoxybenzoyl)benzylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2-phenylpropylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2-phenylethylphosphine oxide Catalyst, 2,6-dimethoxybenzoylbenzylbutylphosphine oxide, 2,6-dimethoxybenzoylbenzyloctylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-2,5-diisopropylphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-2-methylphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-4-methylphenylphosphine oxide, bis(2,4,Examples include 6-trimethylbenzoyl)-2,3,5,6-tetramethylphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-2,4-di-n-butoxyphenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, bis(2,4,6-trimethylbenzoyl)isobutylphosphine oxide, 2,6-dimethitoxybenzoyl-2,4,6-trimethylbenzoyl-n-butylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-2,4-dibutoxyphenylphosphine oxide, 1,10-bis[bis(2,4,6-trimethylbenzoyl)phosphine oxide]decane, tri(2-methylbenzoyl)phosphine oxide, etc.

[0102] The photopolymerization initiators described above may be used individually or in combination of two or more.

[0103] From the viewpoint of ensuring favorable polymerization, the content of the polymerization initiator is preferably 0.01 parts by mass or more, more preferably 0.02 parts by mass or more, and even more preferably 0.05 parts by mass or more, per 100 parts by mass of the total monomer components. From the viewpoint of ensuring that the molecular weight of the polymer in the heat insulating material is within a suitable range and suppressing decomposition products, the content of the polymerization initiator is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, even more preferably 3 parts by mass or less, and particularly preferably 1 part by mass or less, per 100 parts by mass of the total monomer components.

[0104] The thermal insulation material and thermal insulation material precursor may contain a plasticizer as an additive. By using a plasticizer, the adhesion of the thermal insulation material precursor and the elongation of the thermal insulation material can be further improved. Examples of plasticizers include tackifiers such as butadiene rubber, isoprene rubber, silicone rubber, styrene-butadiene rubber, chloroprene rubber, nitrile rubber, butyl rubber, ethylene propylene rubber, urethane rubber, acrylic resin, rosin-based resin, terpene-based resin, or polyalkylene glycol. The plasticizer content may be 0.1 parts by mass or more, 1 part by mass or more, or 3 parts by mass or more, and may be 20 parts by mass or less, 15 parts by mass or less, 12 parts by mass or less, or 10 parts by mass or less, per 100 parts by mass of the total monomer components.

[0105] The thermal insulation material and thermal insulation material precursor may further contain other additives as needed. Examples of other additives include antioxidants, surface treatment agents (e.g., silane coupling agents), dispersants, colorants, nucleating agents, heat stabilizers, foaming agents, flame retardants, vibration damping agents, dehydrating agents, and flame retardant aids (e.g., metal oxides). The content of other additives may be 0.1% by mass or more and 30% by mass or less based on the total amount of thermal insulation material (thermal insulation material precursor).

[0106] The thermal insulation precursor is preferably liquid at 25°C. This allows for suitable application to the surface of semiconductor devices and improves adhesion to the application surface. The thermal insulation precursor may also be solid at 25°C, in which case it is preferable to become liquid upon heating (for example, at 50°C or higher). The thermal insulation precursor can be applied in a liquid state and then cured, which can suppress dripping and pump-out phenomena of the thermal insulation precursor.

[0107] The thickness of the sheet placed in the semiconductor device is not particularly limited and may be, for example, 200 μm or more and 2000 μm or less.

[0108] In the reflow process following the placement process, the semiconductor device is reflowed using a known method. Specifically, for example, the semiconductor device is placed in a reflow oven, the oven temperature is gradually increased to a maximum temperature of 240-260°C, and then the temperature is gradually decreased. This causes the solder paste to sinter and the wiring board to be electrically connected to the substrate.

[0109] In the peeling process following the reflow process, the thermal insulation material is peeled off from the semiconductor device. The peeling method is not particularly limited, and may be, for example, a method in which an adhesive film is attached to the thermal insulation material and the thermal insulation material is peeled off by pulling the adhesive film. Alternatively, the peeling method may be, for example, a method in which a tape remover (for example, "OTR-600SA" manufactured by Omiya Kogyo Co., Ltd.) is used to press a roller against the thermal insulation material via a support film and peel off the thermal insulation material by winding it up together with the support film. [Examples]

[0110] The present invention will be described in more detail below based on examples of the manufacture of thermal insulation materials, but the present invention is not limited in any way to these examples.

[0111] [Synthesis of compounds represented by formulas (1-5)] A 500 mL flask, consisting of a stirrer, thermometer, nitrogen gas inlet tube, outlet tube, and heating jacket, was used as the reactor. 225 g of glycol containing polyoxyalkylene chains (Sanyo Chemical Industries, Ltd.'s "Newpol 75H-90000") and 300 g of toluene were added to the reactor and stirred at 45°C and a stirring speed of 250 revolutions / minute. Nitrogen was supplied at a rate of 100 mL / min and stirred for 30 minutes. The temperature was then lowered to 25°C. After the cooling was complete, 2.9 g of acryloyl chloride was added dropwise to the reactor and stirred for 30 minutes. Then, 3.8 g of triethylamine was added dropwise and stirred for 2 hours. The temperature was then raised to 45°C and the reaction was allowed to proceed for 2 hours. The reaction mixture was filtered, and the filtrate was desoluble to obtain a compound represented by formula (1-5) (weight-average molecular weight: 15000, where m1+m2 in formula (1-5) is approximately 252±5 and n1+n2 is approximately 63±5 integers (where m1, m2, n1, and n2 are each integers of 2 or more, and m1+n1≧100, m2+n2≧100), a mixture with a viscosity of 50 Pa·s at 25°C). [ka] [In equations (1-5), -r- represents random copolymerization.]

[0112] [Manufacturing of insulation materials] 39.2 parts by mass of the compound represented by formula (1-5), 23.5 parts by mass of dicyclopentanyl acrylate ("Funkril® FA-513A" manufactured by Showa Denko Materials Co., Ltd.), 15.7 parts by mass of 4-hydroxybutyl acrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd.), 11.0 parts by mass of the first hollow particle ("Matsumoto Microsphere® F-190SSD" manufactured by Matsumoto Oil & Pharmaceutical Co., Ltd., average particle size: 10-15 μm, maximum volume expansion ratio: 50 times or more, expansion start temperature: 155-165°C, maximum expansion temperature: 210-220°C), and the second hollow particle ("Expancel® 920DE80d30" manufactured by Nippon Philite Co., Ltd., average particle size: 60-90 μm, density: 30 ± 3 kg / m³). 3A thermal insulation precursor was obtained by mixing 5.8 parts by mass of (maximum volume expansion ratio: less than 5 times), 0.9 parts by mass of polymerization initiator (perbutyl oxide, "Perbutyl® O" manufactured by NOF Corporation), 3.1 parts by mass of phenolic antioxidant ("ADEKA Stab® AO-80" manufactured by ADEKA Corporation), and 0.8 parts by mass of surface modifier ("BYK® 350" manufactured by BYK Corporation).

[0113] Next, two substrates were prepared, each consisting of a release-treated PET sheet (Toyobo Co., Ltd.'s "A31") with the release-treated side facing upwards on a glass plate. A 10cm x 15cm x 1.0mm silicone rubber mold was placed on the PET sheet of one substrate, and the inside of the mold was filled with a thermal insulation precursor. Furthermore, the release-treated side of the PET sheet of the other substrate was placed on the side with the thermal insulation precursor, and the other substrate was used as a lid. The substrate was then heated at 135°C for 15 minutes to cure the thermal insulation precursor. This resulted in obtaining a sheet-like thermal insulation material (1.0mm thick).

[0114] [Measuring Adhesion] After attaching the prepared insulation material to the glass slide and letting it stand for at least 15 minutes, [1] Unheated at 25°C, [2] After heating at 220°C for 120 seconds and then cooling to 25°C, [3] After heating at 260°C for 30 seconds and then cooling to 25°C Three types of samples were prepared. For these samples [1], [2], and [3], the adhesive strengths F0, F1, and F2 were measured using the "EZ Test EZ-S" manufactured by Shimadzu Corporation (90° peel, tensile speed: 50 mm / min). The results were as follows. F0: 29 N / m F1: ≥200N / m (When attempting to peel it off, the insulation material underwent cohesive failure and could not be removed.) The F2 value was 12 N / m. Thus, it was found that this insulating material, due to its large F1, adheres well to the semiconductor device during the reflow process, protecting it from heat, while its small F2 allows it to be easily removed in the peeling process after the reflow process.

[0115] [Measurement of thermal conductivity] The fabricated insulation material was sandwiched between PET sheets, cut into 8cm x 13cm x 1.0mm pieces, and its thermal conductivity was measured at 25°C using a rapid thermal conductivity meter (Kyoto Electronics Manufacturing Co., Ltd. "QTM-710", measurement probe PD-11N, thin film measurement mode) by sandwiching the pieces between a reference plate and a measuring probe. The reference material consisted of two layers of release-treated PET (Toyobo Co., Ltd. "A31") sandwiched between the reference plate and measuring probe for measurement. The thermal conductivity of the above insulation material was 66 mW / (m·K).

[0116] [Evaluation of thermal insulation properties] A thermocouple was attached to a substrate (Showa Denko MCL-E-700GR, copper etched), and the aforementioned insulating material was attached to the substrate, sandwiching the thermocouple, to prepare a sample. The insulating material surface of this sample was placed on a hot plate heated to 200°C, and the time t required for the temperature on the substrate to stabilize and the temperature T1 at the time of stabilization were measured, as well as the temperature T2 on the hot plate. The difference between the temperature T1 on the substrate and the temperature T2 on the hot plate (T1-T2) was calculated to be -47°C, and the time t required for the temperature on the substrate to stabilize was 52 seconds. On the other hand, for comparison, when the same measurement was performed without using insulation material, the difference (T1-T2) was 0°C and the time t was 1 second. Thus, it was found that the insulation material has excellent thermal insulation properties. [Explanation of symbols]

[0117] 1A, 1B, 11A, 11B... Semiconductor equipment, 2, 12... Substrate, 3... Solder (solder paste), 4... Lead, 5... Wire, 6, 16... Semiconductor chip, 7... Die attach material, 8... Die pad, 9, 17... Encapsulating material, 10, 18... Insulating material, 13... Solder (solder ball), 14... Interposer, 15... Adhesive, 16a... Protruding electrode.

Claims

1. A step of placing an adhesive heat insulating material on a semiconductor device, A step of reflowing the semiconductor device on which the thermal insulation material is placed, A step of peeling the heat insulating material from the semiconductor device, Equipped with, A method for manufacturing a semiconductor device, wherein the aforementioned thermal insulation material satisfies the following formula (A). F1 > F2 ... (A) [In the formula, F1 represents the adhesive strength of the insulating material after heating it at 220°C for 120 seconds, and F2 represents the adhesive strength of the insulating material after heating it at 260°C for 30 seconds.]

2. A step of placing an adhesive heat insulating material on a semiconductor device, A step of reflowing the semiconductor device on which the thermal insulation material is placed, A step of peeling the heat insulating material from the semiconductor device, Equipped with, A method for manufacturing a semiconductor device, wherein the thermal insulation material satisfies the following formula (B). F0 ≤ F1 …(B) [In the formula, F0 represents the adhesive strength of the insulating material at 25°C, and F1 represents the adhesive strength of the insulating material after heating it at 220°C for 120 seconds.]

3. A step of placing an adhesive heat insulating material on a semiconductor device, A step of reflowing the semiconductor device on which the thermal insulation material is placed, A step of peeling the heat insulating material from the semiconductor device, Equipped with, A method for manufacturing a semiconductor device, wherein the thermal insulation material contains a matrix polymer and thermally expandable hollow particles.

4. A method for manufacturing a semiconductor device according to any one of claims 1 to 3, wherein in the step of arranging the heat insulating material, the heat insulating material which has been pre-formed into a sheet is arranged.

5. A method for manufacturing a semiconductor device according to any one of claims 1 to 3, wherein in the step of arranging the thermal insulation material, a liquid thermal insulation material precursor is arranged on the semiconductor device, and then the thermal insulation material precursor is cured.

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