Resin composition for side fill, semiconductor device, method for removing side fill material, and method for manufacturing a semiconductor device.

Abstract

The present invention provides a resin composition for side filling, the resin composition being easily imparted with high UV curability even if partially interposed in a space between a mounting component and a base material of a semiconductor device by means of side filling, while enabling a side filling material formed therefrom to be easily imparted with excellent repairability. This resin composition for side filling is used for the production of a side filling material 4 which is interposed between a base material 2 and a peripheral edge part of a surface of a mounting component 3 that is surface-mounted on the base material 2, the surface facing the base material 2. This resin composition for side filling contains a cationically polymerizable component (A) and a cationic photopolymerization initiator (B). The cationically polymerizable component (A) contains at least one of an oxetane compound (A1) and an alicyclic epoxy compound (A2). The ratio of the sum of the amount of the oxetane compound (A1) and the amount of the alicyclic epoxy compound (A2) to the total amount of the cationically polymerizable component (A) is 70% by mass or more.

Description

[Technical Field]

[0001] This disclosure relates to a resin composition for side filling, a semiconductor device, a method for removing side filling material, and a method for manufacturing a semiconductor device. More specifically, it relates to a resin composition for side filling used to reinforce mounted components such as semiconductor elements, a semiconductor device equipped with a side filling material made from the resin composition, a method for removing side filling material from a substrate in a semiconductor device, and a method for manufacturing a semiconductor device. [Background technology]

[0002] Conventionally, in semiconductor devices comprising a substrate and mounted components mounted on the substrate, a resin composition is supplied by filling or coating the gap between the substrate and the mounted components in order to reinforce the connection between the substrate and the mounted components. There are two methods for reinforcing the substrate and mounted components by filling the gap between the substrate and the mounted components with a resin composition: an underfill method and a sidefill method.

[0003] In the underfill method, a resin composition is filled into the entire gap between the substrate and the mounted component, and the resin composition is cured to seal the gap between the substrate and the mounted component, thereby reinforcing the connection between the substrate and the mounted component.

[0004] On the other hand, in the side-fill method, the resin composition is applied to only a portion of the area between the substrate and the mounted component, for example, only the peripheral edge of the mounted component in a plan view, and the resin composition is cured to reinforce the area between the substrate and the mounted component, particularly the peripheral edge of the surface of the mounted component facing the substrate. Compared to underfill material, side-fill material has a smaller bonding area between the substrate and the mounted component, so if a defective mounted component is found during inspection or use, it can be easily removed from the substrate and replaced with a good one, offering excellent repairability. However, the side-fill method tends to reduce the reliability of semiconductor devices (especially heat resistance reliability).

[0005] For example, Patent Document 1 discloses an epoxy resin composition containing an epoxy resin, a curing agent, and an inorganic filler, wherein a thermosetting curing agent is used as the curing agent for the epoxy resin. It discloses that a side fill material is produced by interposing this epoxy resin composition between a semiconductor element and a substrate and thermosetting it. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2013-102167 [Overview of the project]

[0007] The purpose of this disclosure is to provide a resin composition for side filling, a semiconductor device, a method for removing side filling material, and a method for manufacturing a semiconductor device, which can be easily imparted with high UV curability even when interposed as a side fill in a portion of the gap between a substrate and mounted components, and which can also be easily repaired even when the side fill material is manufactured.

[0008] A resin composition for side filling according to one aspect of the present disclosure is used to produce a side filling material interposed between a substrate and the peripheral edge of a surface-mounted component facing the substrate. The resin composition for side filling contains a cationic polymerizable component (A) and a photocationic polymerization initiator (B). The cationic polymerizable component (A) contains at least one of an oxetane compound (A1) and an alicyclic epoxy compound (A2). The ratio of the total amount of the oxetane compound (A1) and the alicyclic epoxy compound (A2) to the total amount of the cationic polymerizable component (A) in the resin composition for side filling is 70% by mass or more.

[0009] A semiconductor device according to one aspect of the present disclosure comprises a substrate, a mounted component, and a side fill material. The mounted component is surface-mounted on the substrate. The side fill material is interposed between the substrate and the peripheral edge of the surface of the mounted component facing the substrate. The side fill material consists of a cured product of the side fill resin composition.

[0010] A method for removing side fill material according to one aspect of the present disclosure includes removing the side fill material from between the peripheral edge of the mounted component and the substrate while the side fill material in the semiconductor device is heated to 200°C or higher.

[0011] A method for manufacturing a semiconductor device according to one aspect of the present disclosure comprises a substrate, a mounted component surface-mounted on the substrate, and a side-fill material interposed between the substrate and the peripheral edge of the surface of the mounted component facing the substrate. The side-fill material consists of a cured product of the side-fill resin composition. The method for manufacturing the semiconductor device includes a coating step and a curing step. The coating step is a step of coating the side-fill resin composition on the substrate and the peripheral edge of the surface of the mounted component facing the substrate. The curing step is a step of curing the coated side-fill resin composition. The curing step includes irradiating the side-fill resin composition with light. [Brief explanation of the drawing]

[0012] [Figure 1] Figure 1A is a schematic cross-sectional view showing a semiconductor device according to one embodiment of the present disclosure. Figure 1B is a schematic enlarged view showing an enlarged view of the portion of the semiconductor device shown in Figure 1A indicated by the dashed line. [Figure 2]Figure 2A is a plan view showing a first example in a semiconductor device according to one embodiment of the present disclosure, in which side fill material is interposed around the periphery of a mounted component. Figure 2B is a plan view showing a second example in a semiconductor device according to one embodiment of the present disclosure, in which side fill material is interposed around the periphery of a mounted component. Figure 2C is a plan view showing a third example in a semiconductor device according to one embodiment of the present disclosure, in which side fill material is interposed around the periphery of a mounted component. [Modes for carrying out the invention]

[0013] 1. Overview First, we will explain the process that led to the completion of the resin composition for side filling described herein.

[0014] In a semiconductor device comprising a substrate and mounted components mounted on the substrate, a method called side-filling is used to reinforce the connection between the substrate and the mounted components by filling the gap between the substrate and the mounted components with a resin composition. As a resin composition used in the side-filling method, for example, an epoxy resin composition such as that described in Patent Document 1 (JP 2013-102167) has been proposed.

[0015] However, the inventors found that with the epoxy resin composition described in Patent Document 1, when the epoxy resin composition is sufficiently cured to produce a cured product, it is difficult to completely remove the residue of the side fill material from the substrate and mounted components when repairs are needed for components mounted on the substrate, resulting in poor repairability. Furthermore, it was difficult to achieve high curability with UV light with the aforementioned epoxy resin composition.

[0016] Therefore, in order to solve the aforementioned problems, the inventors proceeded with the research and development of resin compositions for sealing, and as a result of diligent study, developed the side-fill resin composition of this disclosure.

[0017] The side-fill resin composition according to this embodiment is used to produce a side-fill material 4 interposed between a substrate 2 and the peripheral edge of the surface of a mounted component 3 facing the substrate 2, which is surface-mounted on the substrate 2. The side-fill resin composition according to this embodiment contains a cationic polymerizable component (A) and a photocationic polymerization initiator (B). The cationic polymerizable component (A) contains at least one resin from oxetane compound (A1) and alicyclic epoxy compound (A2). The ratio of the total amount of oxetane compound (A1) and alicyclic epoxy compound (A2) to the total amount of cationic polymerizable component (A) in the side-fill resin composition is 70% by mass or more. Therefore, even if the side-fill resin composition of this embodiment is interposed in a part of the gap between the substrate 2 and the mounted component 3 by the side-fill method to produce the side-fill material 4, high UV curability can be imparted to the side-fill resin composition, and excellent repairability can be imparted to the side-fill material 4. In this disclosure, "side fill material" refers to a material used to reinforce mounted components such as semiconductor elements that are surface-mounted on a substrate. In this embodiment, the side fill material 4 consists of a cured product of a side fill resin composition. The side fill material 4 can also be described as a reinforcing material used by being interposed between the substrate 2 and the peripheral edge of the surface of the mounted component 3 that faces the substrate 2. The peripheral edge of the surface of the mounted component 3 that faces the substrate 2 may be the entire peripheral edge of the mounted component 3 in a plan view, or it may be at least a part of the entire peripheral edge.

[0018] The reason why the above effects are exhibited by the side-fill resin composition of the present embodiment has not been clarified exactly, but it is considered to be attributable to the following reasons. That is, when the side-fill resin composition contains a cationically polymerizable component (A) and a photocationic polymerization initiator (B), UV curability can be imparted to the side-fill resin composition. Both the oxetane compound (A1) and the alicyclic epoxy compound (A2) tend to have curing accelerated by an acid generated from the photocationic polymerization initiator (B) during UV irradiation. Furthermore, it is considered that when the ratio of the total amount of the oxetane resin (A1) and the alicyclic epoxy resin (A2) relative to the entire cationically polymerizable component (A) is 70% by mass or more, high UV curability can be obtained. "UV curability" in the present disclosure is measured by the same method as the evaluation shown in "2.3. UV curability" in the Examples described later, and can be confirmed based on the results obtained from the measurement.

[0019] Furthermore, unlike conventional thermosetting side-fill resin compositions, the side-fill resin composition of this embodiment can be cured simply by interposing it between the substrate 2 and the mounted component 3 and irradiating it with light, without heating. Therefore, when a side-fill material 4 is made from the side-fill resin composition, the adhesion strength between the substrate 2 and the side-fill material 4 cannot be excessively increased. As a result, even when removing the side-fill material 4 made on the substrate 2 in the event of a defect in the semiconductor device 1, the residue of the side-fill material 4 can be easily removed from the substrate 2 and the mounted component 3. The side-fill material 4 on the substrate 2 can be removed, for example, by heating it to the solder melting temperature (approximately 200°C). Another reason why the removal of the side-fill material 4 is easy is thought to be due to the following effect: When a side-fill resin composition containing a cationic polymerizable compound (A) and a photocationic polymerization initiator (B) is cured, an acid component produced as a by-product from the photocationic polymerization initiator (B) may remain in the cured product. When this cured product is heated to a higher temperature, the acid component reacts with the cured product, causing the cured product to decompose thermally. This reduces the physical properties of the cured product, making it easier to peel off from the substrate. For this reason, it is presumed that the resin composition for side fill in this embodiment can impart excellent repairability to the side fill material. In this disclosure, "repairability" refers to the ease with which the cured product (including underfill material and side fill material) made from the resin composition in the semiconductor device 1 can be removed from the substrate 2. The repairability of the cured product in the semiconductor device 1 can be confirmed by the method described in "2.4. Repairability" in the examples shown later.

[0020] Thus, according to this embodiment, the cured product made from the side-fill resin composition can be easily removed by heating, so even if a defect occurs in the semiconductor device 1, the side-fill resin composition of this embodiment is easy to repair. Furthermore, the side-fill resin composition according to this embodiment can reinforce the connection between the substrate 2 of the semiconductor device 1 and the peripheral edge of the surface of the mounted component 3 facing the substrate 2.

[0021] More specifically, the preferable properties of the resin composition for side fill can be achieved by appropriately adjusting the components of the composition described below.

[0022] 2. Details The components that may be contained in the resin composition for side fill according to the present embodiment and the properties of the resin composition for side fill will be described more specifically.

[0023] The resin composition for side fill of the present embodiment contains a cationically polymerizable component (A) and a photo cationic polymerization initiator (B). The cationically polymerizable component (A) contains at least one compound selected from an oxetane compound (A1) and an alicyclic epoxy compound (A2). The ratio of the total amount of the oxetane compound (A1) and the alicyclic epoxy compound (A2) to the total amount of the cationically polymerizable component (A) is 70% by mass or more. The resin composition for side fill of the present embodiment has high UV curability. Therefore, when producing the side fill material 4 interposed between the base material 2 and the peripheral edge of the surface of the mounted component 3 facing the base material 2 in the semiconductor device 1 by light irradiation, an uncured portion is less likely to occur in the side fill material 4.

[0024] A semiconductor device 1 equipped with a side fill material 4 made from a cured product of the side fill resin composition of this embodiment can have excellent heat resistance and repairability. In particular, conventionally, when reinforcing materials are made from thermosetting resin components in the presence of a curing agent by the side fill method, repairability has been improved by adding additives such as flexibility imparters. In this case, there was a problem that the thermal properties of the semiconductor device 1, such as heat resistance and thermal shock resistance, may decrease due to the influence of the flexibility imparter. In contrast, with the side fill resin composition of this embodiment, a semiconductor device 1 equipped with a cured product of the side fill resin composition can have excellent thermal shock resistance, and furthermore, the side fill material 4 can have excellent repairability even without adding additives such as flexibility imparters. For this reason, in this embodiment, even if a defect occurs in the semiconductor device 1, the cured product can be easily removed by heating, and when repairing a defect occurs, it is easy to replace only the defective part.

[0025] Furthermore, as described above, the side-fill resin composition of this embodiment is UV-curable. Therefore, when reinforcing the peripheral edge of the surface of the mounted component 3 facing the base material 2 with a cured product of the side-fill resin composition between the base material 2 of the semiconductor device 1 and the mounted component 3 surface-mounted on the base material 2, the cycle time (for example, the time required to form the cured product) can be shortened compared to filling and curing a thermosetting resin component. In addition, since a cured product can be produced without heating to cure the side-fill resin composition, the side-fill material 4 is less susceptible to the effects of thermal history due to heating. Therefore, the side-fill resin composition can make it difficult for the mounted component 3 in the semiconductor device 1 to detach, reinforcing the base material 2 and the peripheral edge of the mounted component 3 facing the base material 2, and making it less likely for conductivity problems to occur in the semiconductor device 1.

[0026] Furthermore, the side-fill resin composition of this embodiment is less prone to the inclusion of air bubbles before and after curing when producing the side-fill material 4 compared to compositions containing a large amount of thermosetting resin components. As a result, voids are less likely to form in the cured product, and consequently, even if the peripheral portion of the surface of the mounted component 3 facing the substrate 2 is reinforced with the side-fill resin composition, defects in the semiconductor device 1 are less likely to occur.

[0027] As a result, by interposing the side-fill resin composition between the substrate 2 of the semiconductor device 1 and the peripheral edge of the surface-mounted component 3 facing the substrate 2, the side-fill material 4 can be manufactured in a short time, and the side-fill material 4 is less likely to retain thermal history. Therefore, the side-fill material 4 (reinforcement material) manufactured from the side-fill resin composition is less prone to warping and voids.

[0028] [Cationic polymerizable components] The cationic polymerizable component (A) contains, for example, a photocatalytically polymerizable compound. The cationic polymerizable component (A) has the property of curing by a polymerization reaction caused by an acid produced from the photocatalytic polymerization initiator (B). For example, it is preferable that the cationic polymerizable component (A) has the property of undergoing a ring-opening polymerization reaction with the photocatalytic polymerization initiator (B). In this embodiment, the cationic polymerizable component (A) contains at least one of an oxetane compound (A1) and an alicyclic epoxy compound (A2) contained in the photocatalytically polymerizable compound. In this embodiment, by having the total amount of the oxetane compound (A1) and the alicyclic epoxy compound (A2) in the cationic polymerizable component (A) be 70% by mass or more of the total amount of the cationic polymerizable component (A), high UV curability can be imparted to the side-fill resin composition, and the cured product of the side-fill resin composition can be given superior repairability.

[0029] If the side-fill resin composition contains a photocationically polymerizable compound, then in the semiconductor device 1, when the substrate 2 and mounted components 3 are reinforced with a cured product of the side-fill resin composition, excellent reliability in heat cycling can be provided. In this disclosure, "heat cycling" refers to a temperature cycle in which heating and cooling are repeatedly performed between a low temperature range (e.g., -40°C) and a high temperature range (e.g., 125°C).

[0030] In this embodiment, as described above, the cationic polymerizable component (A) contains at least one of an oxetane compound (A1) and an alicyclic epoxy compound (A2), and the total amount of the oxetane compound (A1) and the alicyclic epoxy compound (A2) is 70% by mass or more of the total amount of the cationic polymerizable component (A). Therefore, the side-fill resin composition is easier to make low viscosity compared to the case where only a thermally polymerizable component is contained. For this reason, even if the proportion of components such as the inorganic filler described later is increased in the side-fill resin composition, the viscosity of the side-fill resin composition does not tend to increase. This makes it easier to adjust the coefficient of linear expansion of the cured product to be low, and therefore the thermal shock resistance of the semiconductor device 1 equipped with a cured product made from the side-fill resin composition can be improved. For this reason, the semiconductor device 1 can have high thermal reliability.

[0031] In this embodiment, the cationic polymerizable component (A) contains at least one of an oxetane compound (A1) and an alicyclic epoxy compound (A2), and the ratio of the total amount of the oxetane compound (A1) and the alicyclic epoxy compound (A2) to the total amount of the cationic polymerizable component (A) is 70% by mass or more. The ratio of the total amount of the oxetane compound (A1) and the alicyclic epoxy compound (A2) to the total amount of the cationic polymerizable component (A) is more preferably 75% by mass or more, even more preferably 80% by mass or more, and particularly preferably 85% by mass or more. There is no particular upper limit to the ratio of the total amount of the oxetane compound (A1) and the alicyclic epoxy compound (A2) to the total amount of the cationic polymerizable component (A), but it may be, for example, 100% by mass.

[0032] The cationic polymerizable component (A) may contain only one of either the oxetane compound (A1) or the alicyclic epoxy compound (A2), but it is more preferable that the cationic polymerizable component (A) contains both the oxetane compound (A1) and the alicyclic epoxy compound (A2). When the cationic polymerizable component (A) contains both the oxetane compound (A1) and the alicyclic epoxy compound (A2), the alicyclic epoxy compound (A2) has higher photoreactivity in the initial stages of the reaction, making it easier for the reaction to proceed smoothly in the initial stages of the curing reaction. On the other hand, although the reaction rate of the oxetane compound (A1) is slower in the initial stages than that of the alicyclic epoxy compound (A2), as the curing reaction of the alicyclic epoxy compound (A2) progresses and the concentration of the cured product increases, the reactivity of the oxetane compound (A1) can be gradually increased. Therefore, when the cationic polymerizable component (A) contains both an oxetane compound (A1) and an alicyclic epoxy compound (A2), the UV curability of the side-fill resin composition is more easily enhanced.

[0033] The ratio of the oxetane compound (A1) to the alicyclic epoxy compound (A2) in the cationic polymerizable component (A) is in the range of 1:0 to 0:1. More preferably, the ratio of the oxetane compound (A1) to the alicyclic epoxy compound (A2) is in the range of 9:1 to 2:8, and even more preferably, in the range of 9:1 to 3:7.

[0034] Oxetane compound (A1) is, for example, a compound having at least one oxetane skeleton in one molecule. Specifically, as oxetane compound (A1), examples include at least one compound selected from the group consisting of 3-ethyl-3-hydroxymethyloxetane, 2-ethylhexyloxetane, 3-ethyl-3-(2-ethylhexyloxymethyl)oxetane, 3-ethyl-3-(cyclohexyloxy)methyloxetane, and 3-ethyl-3-(phenoxymethyl)oxetane.

[0035] Alicyclic epoxy compounds (A2) are compounds having at least one epoxy group in one molecule, wherein two carbon atoms in the cyclic ether constituting the epoxy group are located on a saturated or unsaturated carbon ring that does not possess aromaticity. Specifically, examples of alicyclic epoxy compounds (A2) include at least one compound selected from the group consisting of 3',4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate, 3,4-epoxycyclohexylmethyl (3',4'-epoxy)cyclohexanecarboxylate, ε-caprolactone-modified 3',4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate, bis(3,4-epoxycyclohexyl)adipate, 1,2-epoxy-4-vinylcyclohexane, 1,4-cyclohexanedimethanol diglycidyl ether, epoxyethyldivinylcyclohexane, diepoxyvinylcyclohexane, 1,2,4-triepoxyethylcyclohexane, and limonene dioxide.

[0036] If the ratio of the total amount of oxetane compound (A1) and alicyclic epoxy compound (A2) to the total amount of cationic polymerizable component (A) is 70% by mass or more, the cationic polymerizable component (A) may also contain cationic polymerizable compounds other than oxetane compound (A1) and alicyclic epoxy compound (A2).

[0037] Cationic polymerizable compounds other than oxetane compounds (A1) and alicyclic epoxy compounds (A2) may include, for example, at least one selected from the group consisting of epoxy compounds other than alicyclic epoxy compounds (A2) (A3) and vinyl ether compounds. Epoxy compound (A3) is preferably photocationically polymerizable. However, it is not limited to this, and epoxy compound (A3) may also be thermosetting.

[0038] Specifically, the epoxy compound (A3) can be at least one compound selected from the group consisting of biphenyl-type epoxy resins, bisphenol A-type epoxy resins, bisphenol F-type epoxy resins, bisphenol S-type epoxy resins, naphthalene ring-containing epoxy resins, anthracene ring-containing epoxy resins, phenol novolac-type epoxy resins, cresol novolac-type epoxy resins, triphenylmethane-type epoxy resins, brome-containing epoxy resins, and triglycidyl isocyanurate. The epoxy resin may also have a glycidyl group.

[0039] When the cationic polymerizable component (A) contains an epoxy compound (A3), the curing reaction rate of the side-fill resin composition can be further adjusted. When the cationic polymerizable component (A) contains an epoxy compound (A3), the mass ratio of the epoxy compound (A3) to the total amount of the cationic polymerizable component (A) is greater than 0% by mass and less than 30% by mass.

[0040] A vinyl ether compound is, for example, a compound having at least one vinyl ether skeleton in one molecule. Specifically, examples of vinyl ether resins include at least one compound selected from the group consisting of ethylene glycol divinyl ether, diethylene glycol divinyl ether, triethylene glycol divinyl ether, polyethylene glycol divinyl ether, propylene glycol divinyl ether, butylene glycol divinyl ether, hexanediol divinyl ether, bisphenol A alkylene oxide divinyl ether, and bisphenol F alkylene oxide divinyl ether.

[0041] When the cationic polymerizable component (A) contains a vinyl ether compound, the mass ratio of the vinyl ether compound to the total amount of the cationic polymerizable component (A) is, for example, greater than 0% by mass and less than 30% by mass.

[0042] The cationic polymerizable component (A) is not limited to those described above, and may be a suitable monomer or oligomer having cationic polymerizability, or may contain resins other than those described above.

[0043] The mass ratio of the cationic polymerizable component (A) to the total solid content of the side-fill resin composition is preferably 10% by mass or more and 60% by mass or less. In this case, the side-fill resin composition can be given even higher UV curability. Furthermore, if the mass ratio of the cationic polymerizable component (A) to the total solid content of the side-fill resin composition is 10% by mass or more, it is easier to maintain better viscosity of the side-fill resin composition during molding. Furthermore, if this mass ratio is 60% by mass or less, it is easier to maintain a low coefficient of linear expansion of the cured product of the side-fill resin composition, and the thermal shock resistance of the semiconductor device 1 equipped with this cured product can be further improved. In this disclosure, "total solid content" refers to the total amount of components other than volatile components such as solvents. The mass ratio of the cationic polymerizable component (A) to the total solid content of the side-fill resin composition is more preferably 10% by mass or more and 50% by mass or less, and even more preferably 10% by mass or more and 40% by mass or less.

[0044] [Photocationic polymerization initiator] The side-fill resin composition of this embodiment contains a photocationic polymerization initiator (B) included in the cationic polymerization initiator. The photocationic polymerization initiator (B) can promote the curing reaction of the cationic polymerizable component (A) in the side-fill resin composition. Preferably, the photocationic polymerization initiator (B) has the function of a photoacid generator, for example. A photoacid generator is a compound that decomposes by absorbing irradiated light and generates acid, thereby polymerizing the polymerizable component.

[0045] The photocationic polymerization initiator (B) contributes to curing the side-fill resin composition, for example, by irradiation with light. In this embodiment, since the side-fill resin composition is photocurable, the side-fill material 4 made from the cured product of the side-fill resin composition can be removed even more easily in the semiconductor device 1.

[0046] The photo-cationic polymerization initiator (B) may be a polymerization initiator that contains an appropriate onium cation as a cationic species and an appropriate anionic species. Examples of the onium cation include sulfonium cations and iodonium cations. Examples of the anionic species include PF6 - -, B(C6F5)4 - -, SbF6 - -, CF3SO3 - -, CF3(CF2)3SO3 - -, p-CH3(CH2) 10 C6H4SO3 - -, and at least one anion selected from the group consisting of dinonylnaphthalene sulfonate anions and p-toluene sulfonate anions.

[0047] The photo-cationic polymerization initiator (B) is, for example, triarylsulfonium·(Rf) n PF 6-n salt, triarylsulfonium PF6 salt, triarylsulfonium SbF6 salt, triarylsulfonium B(C6F5)4 salt, bis[4-n-alkyl(C10~C13)phenyl]iodonium hexafluorophosphate, bis[4-n-alkyl(C10~C13)phenyl]iodonium hexafluoroantimonate, bis[4-n-alkyl(C10~C13)phenyl]iodonium tetrakis(pentafluorophenyl)borate, and bis(4-tert-butylphenyl)iodonium hexafluorophosphate, and includes at least one compound selected from the group consisting of the above.

[0048] Preferably, the photo-cationic polymerization initiator (B) generates an acid when irradiated with light having a wavelength of 200 nm or more and 400 nm or less, for example.

[0049] Specific examples of commercially available photocationic polymerization initiators (B) include sulfonium salts (triarylsulfonium salt types CPI-100P, CPI-101A, CPI-200K, CPI-210S, CPI-310B, CPI-410S) and iodonium salts (IK-1, etc.) manufactured by Sunapro Co., Ltd., and the WPI series of iodonium salts (WPI-113, WPI-116, WPI-124, WPI-170, etc.) manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.

[0050] The ratio of the photocationic polymerization initiator (B) to 100 parts by mass of the cationic polymerizable component (A) is preferably 0.1 parts by mass or more and 10 parts by mass or less. In this case, the repairability of the cured product made from the side-fill resin composition is more easily improved. The ratio of the photocationic polymerization initiator (B) to 100 parts by mass of the cationic polymerizable component (A) is more preferably 0.3 parts by mass or more and 8 parts by mass or less, and even more preferably 0.5 parts by mass or more and 5 parts by mass or less.

[0051] [Inorganic filler] The resin composition for side filler preferably further contains an inorganic filler (C). When the resin composition for side filler contains an inorganic filler (C), the coefficient of thermal expansion (CTE) of the cured product made from the resin composition can be lowered. As a result, warping of the side filler 4 can be made less likely, and this makes it less likely for defects caused by heat generation in the semiconductor device 1 to occur.

[0052] When an inorganic filler (C) is included, the mass ratio of the inorganic filler (C) to the total solid content of the side-fill resin composition is preferably 10% by mass or more and 90% by mass or less. In this case, the CTE of the cured product made from the side-fill resin composition is easier to lower. The mass ratio of the inorganic filler (C) to the total solid content of the side-fill resin composition is more preferably 30% by mass or more and 90% by mass or less. When the mass ratio of the inorganic filler (C) to the total solid content of the side-fill resin composition is 30% by mass or more, the CTE of the cured product of the side-fill resin composition can be further lowered, making it easier to improve the heat resistance reliability of the semiconductor device 1. Furthermore, when this mass ratio is 90% by mass or less, the side-fill resin composition can be easily adjusted to a liquid state. The mass ratio of the inorganic filler (C) to the total solid content of the side-fill resin composition is even more preferably 50% by mass or more and 90% by mass or less.

[0053] The inorganic filler (C) includes at least one material selected from the group consisting of, for example, silica, alumina, clay, mica, talc, aluminum hydroxide, magnesium hydroxide, calcium carbonate, and glass. Silica may be, for example, fused silica, crystalline silica, fumed silica, etc.

[0054] If the inorganic filler (C) contains silica, the silica may be surface-treated. Surface treatment of silica can improve the compatibility between the cationically polymerizable component (A) and the silica in the side-fill resin composition, thereby improving the dispersibility of the side-fill resin composition. Surface treatment of silica can be achieved, for example, by treating the silica with a silane coupling agent. Examples of silane coupling agents include compounds having at least one functional group selected from the group consisting of epoxy groups, amino groups, (meth)acryloyl groups, and phenyl groups.

[0055] The average particle size of the inorganic filler (C) is preferably, for example, 2.5 μm or more and 200 μm or less. When the average particle size of the inorganic filler (C) is within this range, better fluidity of the side-fill resin composition can be maintained when interposing the side-fill resin composition between the substrate 2 and the peripheral edge of the surface of the mounted component 3 facing the substrate 2. Here, "average particle size" in this disclosure is the volume-based median diameter D50. The median diameter D50 is calculated from the particle size distribution obtained by measurement using the laser diffraction-scattering method. The particle size distribution can be measured, for example, by a laser diffraction particle size distribution analyzer.

[0056] [Other ingredients] The side-fill resin composition may contain components other than those described above, as long as they do not impair the effects of the disclosure. For example, the side-fill resin composition may contain resin components other than those described above. The side-fill resin composition may contain, for example, a radical polymerizable compound.

[0057] Furthermore, the encapsulating resin composition may contain appropriate additives. Examples of additives include curing agents, stabilizers, photosensitizers, fluxes, viscosity modifiers, thixotropic agents, surface modifiers, silane coupling agents, defoamers, leveling agents, stress reducers, and pigments. For example, the side-fill resin composition may contain a thixotropic agent. In this case, when supplying the side-fill resin composition to the peripheral edge of the surface of the mounted component 3 facing the substrate 2 between the substrate 2 and the mounted component 3 of the semiconductor device 1, it is easier to ensure better fluidity and thixotropy of the side-fill resin composition. As a result, the side-fill resin composition can have higher moldability, and even when a side-fill material 4 that reinforces the peripheral edge of the mounted component 3 is made from the side-fill resin composition, the side-fill material 4 can be given excellent strength.

[0058] The side-fill resin composition may contain a stabilizer. When the side-fill resin composition contains a stabilizer, the storage stability of the side-fill resin composition can be well maintained even if it contains a cationic polymerization initiator. As the stabilizer, an appropriate antioxidant or other stabilizer can be used, but examples include 2,6-tert-butyl-p-cresol, butylated hydroxyanisole, 2,6-tert-butyl-p-ethylphenol, 2,2-methylenebis(4-methyl-6-tert-butylphenol), 2,2-methylenebis(4-ethyl-6-tert-butylphenol), 4,4'-thiobis(3-methyl-6-tert-butylphenol), etc.

[0059] The side-fill resin composition may contain a flexibility-imparting agent. In this case, when a defect occurs in the semiconductor device 1 and repairs are performed, the repairability can be further improved. However, as described above, the side-fill resin composition of this embodiment can achieve high repairability even without containing a flexibility-imparting agent.

[0060] The side-fill resin composition may contain a photosensitizer. In this case, the curing reaction of the side-fill resin composition can be accelerated. Therefore, the cycle time can be shortened when preparing a cured product from the side-fill resin composition.

[0061] The resin composition for side filling preferably does not contain organic solvents, or has an organic solvent content of 0.5% by mass or less. In this case, it is easier to maintain good viscosity when molding the resin composition for side filling.

[0062] A resin composition for side filling can be obtained, for example, by blending the above components and adding appropriate additives as needed. Specifically, a resin composition for side filling can be prepared, for example, by the following method.

[0063] First, a mixture is obtained by simultaneously or sequentially blending the components that may be included in the side-fill resin composition described above. This mixture is then stirred and mixed while performing heating and cooling treatments as necessary.

[0064] Next, if necessary, additives are added to the mixture, and the mixture is stirred again while performing heating or cooling treatments as needed until it is uniformly dispersed. This yields a resin composition for side filling. For stirring the mixture, for example, a disperser, planetary mixer, ball mill, three-roll mill, and bead mill can be used in appropriate combinations as needed.

[0065] The viscosity of the side-fill resin composition at 25°C is preferably 10 Pa·s to 2000 Pa·s. In this case, it is easier to ensure the moldability of the side-fill resin composition. In this case, good filling between the substrate 2 and the peripheral edge of the surface of the mounted component 3 such as a semiconductor chip that faces the substrate 2 can be achieved. The viscosity of the side-fill resin composition at 25°C can be measured using a B-type viscometer under the conditions of rotor No. 7, rotation speed 1 to 50 rpm, and measurement time 60 to 180 seconds. The conditions for measuring viscosity are appropriately adjusted depending on the composition of the resin composition, etc., but the rotation speed should be set to the maximum rotation speed that can be measured for the resin composition, and the measurement time should be set to a time for the rotor to rotate three or more times for the resin composition. The specific measurement method will be described in detail in the examples below. The viscosity of the side-fill resin composition at 25°C is more preferably 1000 Pa·s or less, even more preferably 700 Pa·s or less, and particularly preferably 400 Pa·s or less. The viscosity of the side-fill resin composition at 25°C is more preferably 50 Pa·s or higher, and even more preferably 100 Pa·s or higher.

[0066] As previously mentioned, the side-fill resin composition of this embodiment is photocurable. Therefore, the side-fill resin composition can be cured by irradiation with light. The conditions for irradiation, such as the irradiation wavelength, irradiation intensity (amount of light), irradiation time, heating temperature, and heating time, can be appropriately adjusted according to the components that may be included in the side-fill resin composition, such as the type of cationic polymerizable component (A) and the type of photocationic polymerization initiator (B). Any suitable light source can be used to irradiate the side-fill resin composition with light. For example, it may be at least one light source selected from the group consisting of chemical lamps, low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, xenon lamps, metal halide lamps, LEDs, YAG, g-line (436nm), h-line (405nm), i-line (365nm), and combinations of two or more of the g-line, h-line, and i-line. The light source is not limited to these, and any light source capable of irradiating ultraviolet light that can cure the side-fill resin composition is acceptable. Furthermore, the side-fill resin composition can be heated using an appropriate heating device.

[0067] The glass transition temperature (Tg) of the cured product of the side-fill resin composition is preferably 130°C or higher. If the glass transition temperature is 130°C or higher, the cured product of the side-fill resin composition can have heat resistance. The glass transition temperature can be measured, for example, by TMA (Thermomechanical Analysis). Furthermore, if the glass transition temperature is 130°C or higher, the cured product of the side-fill resin composition can be made less likely to soften even in the high-temperature range (e.g., around 125°C) of a heat cycle test. Therefore, the side-fill resin composition can ensure high heat resistance reliability in the semiconductor device 1. In particular, in the semiconductor device 1, when mounted components on the substrate are reinforced with side-fill material made from the cured product of a conventional resin composition, poor conductivity between the substrate and mounted components was prone to occur when the semiconductor device 1 was placed in a harsh thermal environment (e.g., below -40°C and above 125°C). In contrast, when a side-fill material for reinforcing mounted components 3 on a substrate 2 in a semiconductor device 1 is prepared from the side-fill resin composition of this embodiment, the cured product of the side-fill resin composition can impart high thermal shock resistance to the semiconductor device 1. Therefore, in this embodiment, poor conductivity in the semiconductor device 1 can be made less likely.

[0068] The coefficient of linear expansion (CTE) of the cured side-fill resin composition below the glass transition temperature Tg is preferably less than 40 ppm / °C. In this case, below the glass transition temperature, the side-fill material 4 made from the cured side-fill resin composition is less likely to warp, and delamination between the substrate 2 and mounted components 3 and the cured side-fill resin composition is less likely to occur. Therefore, cracks are less likely to occur in the cured encapsulating resin composition. As a result, the heat resistance reliability of the semiconductor device 1 can be further improved with the side-fill material 4 made from the side-fill resin composition. The CTE of the cured side-fill resin composition below Tg is more preferably 35 ppm / °C or less, and even more preferably 30 ppm / °C or less. The CTE of the cured side-fill resin composition below Tg can be obtained by calculating the slope of the tangent based on the dimensional change between any two points below Tg.

[0069] As previously described, the side-fill resin composition of this embodiment can be suitably used as a side-fill material. The side-fill resin composition can be particularly suitably used as a post-supply type side-fill material in flip-chip mounting.

[0070] [Semiconductor device] As described above, the side-fill resin composition according to this embodiment can be suitably used to produce a side-fill material 4 that reinforces the substrate 2 and mounted component 3 in the semiconductor device 1. In particular, with the side-fill resin composition, when reinforcing the substrate 2 and mounted component 3, reinforcement can be achieved simply by supplying the side-fill resin composition between the substrate 2 and the peripheral edge of the surface of the mounted component 3 facing the substrate 2. Compared to an underfill material that fills the entire gap between the substrate 2 and the mounted component 3, the amount of resin composition supplied can be reduced. In this case, the reinforced mounted component 3 is less likely to detach, and poor conductivity in the semiconductor device 1 is less likely to occur.

[0071] Furthermore, in the semiconductor device 1, when a connection failure occurs between the substrate 2 and the mounted component 3, only the side fill material 4 supporting the substrate 2 and the mounted component 3 (specifically, the side fill material 4 interposed around the periphery of the mounted component 3) needs to be peeled off, allowing repair without discarding the components of the normal parts. Moreover, the side fill material 4 of this embodiment can be easily removed without heating to excessively high temperatures. Therefore, in the semiconductor device 1, the side fill material 4 made from the side fill resin composition of this embodiment has excellent repairability. Furthermore, as described above, when repairing the semiconductor device 1, the waste of parts other than the defective part can be reduced, thus contributing to cost reduction in the event of a defect compared to underfill material.

[0072] The semiconductor device 1 of this embodiment comprises a substrate 2, a mounted component 3, and a side fill material 4. The mounted component 3 is surface-mounted on the substrate 2. The side fill material 4 is interposed between the peripheral edge of the surface of the mounted component 3 facing the substrate 2. The side fill material 4 is made of a cured product of the side fill resin composition described above.

[0073] Figure 1A shows an example of the semiconductor device 1 of this embodiment.

[0074] The semiconductor device 1 comprises a substrate 2 that supports a mounted component 3 such as a semiconductor chip, a mounted component 3 surface-mounted face-down on the substrate 2, and a side fill material 4 interposed between the substrate 2 and the peripheral edge of the surface of the mounted component 3 facing the substrate 2. The side fill material 4 can support the substrate 2 and the mounted component 3 between the substrate 2 and the peripheral edge of the mounted component 3. That is, in the semiconductor device 1 shown in Figure 1, the side fill material 4 fills only the space between the substrate 2 and a portion of the peripheral edge of the surface of the mounted component 3 facing the substrate 2 in the gap between the substrate 2 and the mounted component 3. In this way, the side fill material 4 reinforces the mounted component 3 surface-mounted on the substrate 2 at the peripheral edge of the mounted component 3.

[0075] The side fill material 4 is formed by supplying a side fill resin composition to the base material 2 and part or all of the peripheral edge of the surface of the mounting component 3 facing the base material 2, and then photocuring it between the base material 2 and the mounting component 3. The distance over which the side fill resin composition penetrates into the inner position of the peripheral edge of the surface of the mounting component 3 facing the base material 2 in a plan view (i.e., the gap between the base material 2 and the mounting component 3 at the peripheral edge of the mounting component 3) can be adjusted as appropriate, but for example, as shown in Figure 1B, it is preferable that the penetration distance b is the same as or shorter than the distance a from the position corresponding to the outer peripheral edge of the mounting component 3 of the side fill resin composition to the outer position of the surface of the mounting component 3 facing the base material 2 (i.e., b ≤ a). The penetration distance is the length over which the side fill resin composition penetrates from the position corresponding to the outer peripheral edge of the mounting component 3 in a plan view to the inner position of the surface of the mounting component 3 facing the base material 2.

[0076] The semiconductor device 1 and its manufacturing method according to this embodiment will be described in detail.

[0077] The semiconductor device 1 comprises a substrate 2 having conductive wiring 21, a mounted component 3 such as a semiconductor chip having bump electrodes 33 which are bonded to the conductive wiring 21 and mounted on the substrate 2, and a side fill material 4 (see Figure 1A). The side fill material 4 is a cured product of the side fill resin composition described above.

[0078] The base material 2 is, for example, a mother board, a package board, or an interposer board. For example, the base material 2 comprises an insulating substrate made of glass epoxy, polyimide, polyester, ceramic, etc., and conductive wiring 21 made of a conductor such as copper formed on its surface. The conductive wiring 21 includes, for example, electrode pads. Furthermore, the side-fill resin composition of this embodiment can be suitably used for printed circuit boards. Therefore, the base material 2 may be a substrate in a suitable printed circuit board, and examples of substrates in a printed circuit board include organic resin substrates such as FR-4, ceramic substrates, metal base substrates, glass substrates, etc.

[0079] Component 3 is, for example, a semiconductor chip. The semiconductor chip is a flip-chip type chip such as a BGA (Ball Grid Array), LGA (Land Grid Array), or CSP (Chip Size Package). The semiconductor chip may also be a PoP (Package-on-Package) type chip.

[0080] The mounted component 3 may have multiple bump electrodes 33. The bump electrodes 33 are made of solder. For example, as shown in Figure 1, the bump electrode 33 comprises a pillar 31 and a solder bump 32 provided at the tip of the pillar 31. The solder bump 32 is made of solder, and therefore the bump electrode 33 is made of solder. The pillar 31 is made of copper, for example.

[0081] The melting point of the solder on the bump electrode 33 (for example, the solder on the solder bump 32) is not particularly limited, but it should be a temperature at which it can melt at or below the mounting temperature when mounting components 3 such as semiconductor chips (for example, 220 to 260°C). The composition of the solder is also not particularly limited and may be any appropriate composition, but for example, it can be Sn-Ag based solder or Sn-Ag-Cu based solder. The structure of the bump electrode 33 with solder is not limited to the above, and for example, the bump electrode 33 may consist only of spherical solder bumps 32 (solder balls). In other words, the bump electrode 33 does not need to have pillars.

[0082] The method for manufacturing the semiconductor device 1 of this embodiment includes a coating step and a curing step. The coating step includes applying a side-fill resin composition to the peripheral edge of the surface of the mounted component 3 facing the substrate 2. The curing step includes curing the side-fill resin composition applied in the coating step.

[0083] In the coating process, it is preferable to coat the semiconductor device 1 such that the volume of side fill material 4 interposed between the substrate 2 and the mounted component 3 at the peripheral edge of the surface where the substrate 2 and the mounted component 3 face each other is smaller than the volume of side fill material 4 interposed only on the substrate 2. In this case, the reinforcing strength by the cured resin composition for side fill between the substrate 2 and the mounted component 3 in the semiconductor device 1 can be improved while shortening the cycle time for manufacturing the semiconductor device 1. In addition, in this case, it is possible to reduce stress on solder bumps 32 and the like in the semiconductor device 1. This contributes to improving the reliability of the semiconductor device 1. Furthermore, even if a defect occurs in the semiconductor device 1, the side fill material 4 can be easily removed, thus ensuring particularly high repairability.

[0084] The curing process includes irradiating the side-fill resin composition with light. In this embodiment, to cure the side-fill resin composition, the side-fill resin composition is applied to the peripheral edge of the mounted component 3, and then cured by irradiating the side-fill resin composition with light. The light irradiation in the curing process is not particularly limited, but can be achieved by an appropriate light source. That is, the conditions for light irradiation and the light source may be the same as those already described. In addition, although the curing of the side-fill resin composition has been described above by irradiating it with light, the side-fill resin composition may be irradiated with light and then heated, for example, as an after-cure, as long as it does not deviate from the operation of this disclosure.

[0085] In the semiconductor device 1 shown in Figure 1A, the side fill material 4 fills only the gap between the substrate 2 and a portion of the peripheral edge of the surface of the mounted component 3 facing the substrate 2. Specifically, the side fill material 4 fills the outer edge and a portion of the inner edge of the peripheral edge of the surface of the mounted component 3 facing the substrate 2. The side fill material that fills the outer edge is sometimes called the first side fill material 41, and the side fill material that fills a portion of the inner edge is sometimes called the second side fill material 42. Note that Figure 1B schematically shows the first side fill material 41 and the second side fill material 42, and does not show the shape or exact position of the first side fill material 41 and the second side fill material 42.

[0086] As described above, the side fill material 4 interposes itself around the peripheral edge of the surface of the mounted component 3 facing the base material 2, thereby reinforcing both the base material 2 and the mounted component 3.

[0087] In the semiconductor device 1, it is preferable that the volume of the side fill material 4 interposed only on the substrate 2 at the peripheral edge of the surface of the substrate 2 facing the mounted component 3 (i.e., the first side fill material 41) is larger than the volume of the side fill material 4 interposed in the gap between the substrate 2 and the mounted component 3 (i.e., the second side fill material 42). In this case, it is possible to reduce stress on solder bumps 32 and the like in the semiconductor device 1. This can contribute to improving the reliability of the semiconductor device 1. In this embodiment, since the side fill resin composition has excellent UV curability, the first side fill material 41 and the second side fill material 42 can be manufactured by applying the side fill resin composition to appropriate positions and then irradiating it with light.

[0088] A method for manufacturing the semiconductor device 1 will be explained with an example. However, the method for manufacturing the semiconductor device 1 is not limited to the method described below. For example, in the semiconductor device 1, the side-fill resin composition described above can be supplied so as to be interposed in part or all of the peripheral edge of the surface of the mounted component 3 that is surface-mounted on the substrate 2, thereby creating a side-fill material 4 and manufacturing the semiconductor device 1.

[0089] First, a base material 2 equipped with conductive wiring 21 and a mounting component 3 equipped with bump electrodes 33 are prepared. The mounting component 3 is placed on the base material 2, and the bump electrodes 33 are placed on the conductive wiring 21. The conductive wiring 21 and the bump electrodes 33 can be electrically connected, for example, by heating.

[0090] Next, the side-fill resin composition is supplied to the peripheral edge of the surface-mounted component 3 facing the base material 2, and then cured by irradiating the supplied side-fill resin composition with light. As a result, a side-fill material 4 is created on the base material 2 and on the peripheral edge of the mounted component 3 facing the base material 2. The curing conditions for the side-fill resin composition are as previously described.

[0091] The above order does not have to be as described above. The side-fill resin composition may be placed at any time and at any position on the mounting component 3 and the base material 2, as long as it can be positioned during the manufacturing process so that it is interposed between the base material 2 and part or all of the peripheral edge of the surface of the mounting component 3 facing the base material 2.

[0092] Specific examples of the positions where the side fill material 4 is placed in the semiconductor device 1 will be explained with reference to Figures 2A to 2C. However, the positions of the side fill material 4 in the semiconductor device 1 are not limited to these.

[0093] Figures 2A to 2C show that in the semiconductor device 1, in a plan view, a side-fill resin composition is supplied between the substrate 2 and the peripheral edge of the surface-mounted component 3 facing the substrate 2, and a side-fill material 4 is produced by curing the resin composition. In other words, Figures 2A to 2C show examples (first to third examples) of a state in which the substrate 2 and the peripheral edge of the mounted component 3 are reinforced with the side-fill material 4. In the semiconductor device 1 shown in Figures 2A to 2C, the side-fill resin composition is not supplied to the deepest part of the gap between the substrate 2 and the mounted component 3, for example, including the entire lower central part of the mounted component 3, but is supplied to the peripheral edge of the surface of the mounted component 3 facing the substrate 2. This is because, with the side-fill resin composition of this embodiment, it is possible to reinforce the substrate 2 and the mounted component 3 in the semiconductor device 1 even if only supplied to the peripheral edge of the mounted component 3. In particular, the side-fill material 4 produced from the side-fill resin composition supports the peripheral edge of the mounted component 3 in the semiconductor device 1. In other words, in this embodiment, the side fill material 4 does not intervene in the entire gap between the base material 2 and the mounted component 3, but only supports the peripheral edge with the side fill material 4, which helps to reduce warping between the base material 2 and the mounted component 3.

[0094] In the first example shown in Figure 2A, a side-fill material 4 made of a cured resin composition for side-filling is formed on the entire periphery of the surface of the mounted component 3 facing the base material 2. In this case, the strength reinforcing the base material 2 and the mounted component 3 in the semiconductor device 1 can be increased, and warping of the base material 2 and the mounted component 3 can be made less likely. In addition, in this case, repairs are easier if a defect occurs in the semiconductor device 1 compared to the case of underfill material.

[0095] In the second example shown in Figure 2B, a side-fill material 4 made of a cured side-fill resin composition is formed on the substrate 2 and on multiple corners of the peripheral edge of the surface of the mounted component 3 facing the substrate 2 (more specifically, including the four corners of the mounted component 3, which is roughly rectangular in plan view). In this case, the strength to reinforce the substrate 2 and mounted component 3 in the semiconductor device 1 can be maintained, and warping of the substrate 2 and mounted component 3 can be made less likely. In addition, in this case, repairs in the semiconductor device 1 are easier compared to the case of underfill material.

[0096] In the third example shown in Figure 2C, side fill material made from a cured side fill resin composition is formed on the corners of the peripheral edge of the surface of the mounted component 3 facing the base material 2, and on two opposing sides. In this case, the strength to reinforce the base material 2 and mounted component 3 in the semiconductor device 1 can be maintained, and warping of the base material 2 and mounted component 3 can be made less likely. In addition, in this case, repairs are easier if a defect occurs in the semiconductor device 1 compared to the case of underfill material. In particular, with the side fill material made from the side fill resin composition of this embodiment, when a defect occurs, it is easy to replace only the defective part when repairing it.

[0097] In this embodiment, a method for removing the side fill material 4 in the semiconductor device 1 will be described.

[0098] The method for removing the side fill material in this embodiment involves heating the side fill material 4 in the semiconductor device 1 to 200°C or higher, and then removing the side fill material 4 from between the peripheral edge of the mounted component 3 and the base material 2. In repairing a defective area in the semiconductor device 1, it is necessary to melt solder material such as solder bumps 32 in order to remove the electrical connection between the base material 2 and the mounted component 3. In this embodiment, the side fill material 4 can be removed by heating it to the melting temperature of the solder material (approximately 200°C) or higher. Therefore, according to the method for removing the side fill material 4 in this embodiment, the semiconductor device 1 can be easily repaired. [Examples]

[0099] The following are specific examples of the present disclosure. However, the present disclosure is not limited to these examples.

[0100] 1. Preparation of resin composition for side fill [Examples 1-24, Comparative Examples 1-5] The components shown in Tables 1-3 below were added to a planetary mixer in the proportions (parts by mass) shown in Tables 1-3, stirred and mixed, and then uniformly dispersed using a three-roll mixer to obtain a resin composition. The details of the components shown in Tables 1-3 are as follows. (Polymerizable components) -Cationic polymerized components • Oxetane compound 1: Photocationic polymerizable compound (manufactured by Toagosei Co., Ltd., product name OXT-221). • Oxetane compound 2: Photocationically polymerizable compound (manufactured by Ube Industries, Ltd., product name: ETERNACOLL OXBP). • Alicyclic epoxy compound 1: Photocationically polymerizable compound (manufactured by Daicel Corporation, product name: Celoxide 2021). • Alicyclic epoxy compound 2: Photocationically polymerizable compound (manufactured by Daicel Corporation, product name: Celoxide 8000). • Alicyclic epoxy compound 3: Photocationically polymerizable compound (manufactured by Daicel Corporation, product name: Celoxide 2081). • Other epoxy compounds 1: Manufactured by DIC Corporation, product name: Epiclon 840A. (Photopolymerization initiator) • Cationic polymerization initiator 1: Manufactured by Sunapro Co., Ltd. Product name: CPI-200K (Photocatalytic cation polymerization initiator. Triarylsulfonium (Rf) n PF 6-n A 50% propylene carbonate solution of the salt. Rf is a perfluoroalkyl group. A non-antimony photoacid generator. • Cationic polymerization initiator 2: BASF product name IRGACURE 290 (photocationic polymerization initiator. Triarylsulfonium tetrakis-(pentafluorophenyl)borate.) Non-antimony photoacid generator. (Thermosetting agent) • Thermosetting agent 1: Acid anhydride-based curing agent (manufactured by DIC Corporation, product name B650). • Thermosetting agent 2: Imidazole-based curing agent (manufactured by Shikoku Chemicals Co., Ltd., 2MAOK). (Additives, etc.) • Inorganic filler: Manufactured by MRC Unitech Co., Ltd., product name QS-6 (30μm cut). • Thixotropic agent: Manufactured by Nippon Aerosil Co., Ltd., product name RY200. • Flexibility enhancer: Manufactured by Kuraray Co., Ltd., product name LBR-302.

[0101] 2. Evaluation Test 2.1. Glass transition temperature In Examples 1-24 and Comparative Examples 1-2, the side-fill resin composition prepared in 1. above was applied to a substrate, and an LED UV irradiator (Panasonic Devices SUNX Co., Ltd., model number Aicure UD40) was used to irradiate the upper surface of the substrate (the side to which the side-fill resin composition was applied) at an irradiation intensity of 1000 mW / cm². 2 The substrate was irradiated with light for 4 seconds under these conditions. Subsequently, the substrate and the light-cured side-fill resin composition applied to the substrate were placed in a heating furnace and cured by heating at 100°C for 30 minutes.

[0102] In Comparative Examples 3 to 5, the side-fill resin composition prepared in 1. above was applied to a substrate, and the substrate and the side-fill resin composition applied to the substrate were placed in a heating furnace and cured by heating at a temperature of 150°C for 30 minutes.

[0103] Test specimens were prepared by cutting the cured resin composition for each of the obtained examples and comparative examples (hereinafter sometimes referred to as "each example, etc.") to a width of 5 mm, a length of 50 mm, and a thickness of 0.2 mm.

[0104] For each prepared test specimen, the glass transition temperature was calculated by measuring the bending mode using the DMA method with a viscoelastic spectrometer (Hitachi High-Tech Science Corporation, model DMA7100). The measurement conditions were a frequency of 10 Hz, a heating rate of 5 °C / min, and a measurement temperature of -60 °C to 280 °C. The glass transition temperatures (°C) of the hardened products obtained are shown in Tables 1 to 3.

[0105] 2.2. Coefficient of linear expansion (α1) In each example, cured resin compositions for side filling were obtained by curing them under the same light irradiation and / or heating conditions as described in 2.1. Test specimens were prepared by cutting each specimen to a width of 3 mm, a length of 3 mm, and a thickness of 15 mm.

[0106] For each prepared test specimen, the specimen was heated using the TMA method with a thermal analyzer (Hitachi High-Tech Science Corporation, model TMA7100) at a heating rate of 5°C / min and a measurement temperature of 30 to 260°C. The linear expansion coefficient α1 below Tg in the temperature range of 50°C to 70°C was calculated. The results of the linear expansion coefficient α1 (ppm / °C) of the cured material obtained are shown in Tables 1 to 3.

[0107] 2.3.Viscosity The resin composition for side filling prepared in step 1 above was placed in a cylindrical container, and its viscosity was measured using a Type B viscometer (Model TVB10, manufactured by Toki Sangyo Co., Ltd.) under the conditions of rotor No. 7 and a measurement temperature of 25°C. The rotation speed of the viscometer was set to the highest measurable speed between 1 and 50 rpm, and the measurement time was set to a duration of at least three rotations within the range of 60 to 180 seconds. Specifically, in Examples 1-13, 15, 16, 18-24, and Comparative Example 1-4, the rotation speed was 10 rpm and the measurement time was 60 seconds. In Comparative Example 5, the rotation speed was 5 rpm and the measurement time was 60 seconds. In Example 14, the rotation speed was 2.5 rpm and the measurement time was 90 seconds. In Example 17, the rotation speed was 1 rpm and the measurement time was 180 seconds. The results obtained are shown in Tables 1 to 3.

[0108] 2.4.UV curability In each example, 10 mg of the side-fill resin composition prepared in 1. above was placed in an aluminum pan (φ5 mm) for DSC (Diffrential Scanning Calorimetry). The placed side-fill resin composition was irradiated with 365 nm wavelength light at an intensity of 400 mW / cm using a UV light source (model LA-410UV, manufactured by Hayashi Repic Co., Ltd.). 2 The sample was irradiated for 2 minutes, and the reaction heat (x1) due to the photocuring reaction during this irradiation was measured and calculated using a DSC measuring device manufactured by Hitachi High-Tech Science Corporation.

[0109] Next, DSC measurements were performed on the cured material after light irradiation as described above, under the conditions of a temperature range of 0°C to 260°C and a heating rate of 10°C / min, and the residual heat generation (x2) of the cured material was calculated.

[0110] The hardening rate (R) was calculated from the obtained reaction heat (x1) and residual heat (x2) based on the following formula, and the hardening rate (R) was evaluated according to the following criteria. Curing rate (R[%])=[1-(x2) / ((x1)+(x2))]×100 A: It is over 80%. B: Between 60% and 80%. C: Less than 60%

[0111] 2.5. Repairability A test specimen with a cured side-fill resin composition on a solder-resist treated glass epoxy substrate (substrate: FR4, manufactured by Panasonic Corporation, 0.6 mm thick / resist: PSR4000, manufactured by Taiyo Ink Mfg. Co., Ltd.) was prepared by applying 10 mg of the side-fill resin composition prepared in 1. above and curing it. The curing conditions were the same as the light irradiation conditions or heating conditions described in 2.1 above.

[0112] The test specimens were placed on a hot plate and heated for 10 minutes until the substrate surface temperature reached 200°C. Then, the cured material was peeled off the substrate using a bamboo skewer, and the condition of the cured material and the substrate were visually inspected and evaluated according to the following criteria. The results are shown in Tables 1 to 3. A: The cured material can be peeled off the substrate, and no residue of the cured material remains on the substrate. B: The cured material can be peeled off the substrate, but residue of the cured material remains on the substrate. C: The cured material could not be removed from the substrate, and the cured material remains on the substrate.

[0113] 2.6. Temperature Cycling (TC) Properties A Test Element Group (TEG) was fabricated by mounting a mounting IC chip (Waltz WLP TEG <0.3mm pitch BGA>, 6mm) onto an FR-4 circuit board (Waltz KIT WLP300P) having daisy-chain electrodes. The side-fill resin composition prepared in 1. above was applied to the TEG between the substrate and the peripheral edge of the IC chip facing the substrate, in a plan view shape (L-shaped at the four corners) as shown in Figure 2B, with a width of 0.8mm and a height of 0.4mm. The length of the contact area between the side-fill resin composition and the IC chip was set to 2.5mm. After irradiating the applied side-fill resin composition with light, a test specimen with a cured side-fill resin composition on the TEG was fabricated by further heating in a heating furnace. The curing conditions were the same as the light irradiation conditions or heating conditions in 2.1 above.

[0114] The fabricated test specimens were subjected to a heat cycle test using a thermal shock tester (model TSE-12-A, manufactured by ESPEC Corporation). The heat cycle test involved applying temperature changes in the gas phase, with one cycle consisting of 30 minutes at -40°C and 30 minutes at 125°C, for a total of 2000 cycles. The operation was confirmed by measuring the resistance value of the test specimen every 100 cycles. A test specimen whose resistance value increased by 5% or more from the start of the test was judged to be malfunctioning and evaluated according to the following criteria. The results are shown in Tables 1 to 3. A: No malfunctions occur even after exceeding 2000 cycles. B: Malfunctions occur between 500 and 2000 cycles. C: Malfunctions occur within 500 cycles.

[0115] 2.7.Dischargeability A syringe manufactured by Musashi Engineering Co., Ltd. (product number PSY-10EU-OR) was filled with the resin composition prepared in step 1, and a needle manufactured by Musashi Engineering Co., Ltd. (product number SNA-22G-B) was attached to the tip of the syringe.

[0116] Next, a dispensing robot manufactured by Musashi Engineering Co., Ltd. (model number SHOTMASTER300ΩX) was used to apply the resin composition from a syringe filled with the resin composition onto a glass plate. The application conditions were a distance of 0.5 mm between the glass plate and the tip of the needle, a travel speed of 3 mm / s, and the resin was applied in a straight line over a length of 10 cm. The appearance of the resin after application was observed visually and evaluated according to the following criteria. A: The resin composition could be applied without interruption. B: Application was possible, but there were interruptions in the process. C: It was impossible to extrude the material from the needle.

[0117] 2.8. Pot life (storage stability of resin composition solutions) First, the viscosity was measured using the same method as described in 2.3. above. Specifically, the side-fill resin composition prepared in 1. above was placed in a cylindrical container, and the viscosity was measured using a Type B viscometer (Model TVB10, manufactured by Toki Sangyo Co., Ltd.) under the conditions of rotor No. 7 and a measurement temperature of 25°C. The rotation speed of the viscometer was set to the highest measurable speed between 1 and 50 rpm, and the measurement time was set to a time within the range of 60 to 180 seconds, during which the rotor rotated at least three times. Specifically, in Examples 1-13, 15, 16, 18-24, and Comparative Example 1-4, the rotation speed was 10 rpm and the measurement time was 60 seconds. In Comparative Example 5, the rotation speed was 5 rpm and the measurement time was 60 seconds. In Example 14, the rotation speed was 2.5 rpm and the measurement time was 90 seconds. In Example 17, the rotation speed was 1 rpm and the measurement time was 180 seconds. This was taken as the viscosity of the side-fill resin composition immediately after preparation. Next, the viscosity of the side-fill resin composition was measured under the same conditions 24 hours, 48 ​​hours, and 72 hours after its preparation. Based on the obtained viscosity immediately after preparation and the viscosity at each time point, the pot life (stability) was evaluated according to the following criteria. A: Even after 72 hours, the viscosity remains less than 1.5 times that of the product immediately after preparation. B: Even after 48 hours, the viscosity is less than 1.5 times that of immediately after preparation, but after 72 hours, the viscosity becomes 1.5 times or more of that of immediately after preparation. C: Even after 24 hours, the viscosity is less than 1.5 times that of the mixture immediately after preparation, but after 48 hours, the viscosity becomes 1.5 times or more of that of the mixture immediately after preparation. D: After 24 hours, the viscosity becomes more than 1.5 times that of the mixture immediately after preparation.

[0118] [Table 1]

[0119] [Table 2]

[0120] [Table 3] [Explanation of symbols]

[0121] 1 Semiconductor device 2 Base material 3. Mounted Components 4. Side fill material

Claims

1. A side-fill resin composition used to produce a side-fill material interposed between a substrate and the peripheral edge of a surface-mounted component facing the substrate, the component being surface-mounted on the substrate. The resin composition for side filling contains a cationic polymerizable component (A) and a photocationic polymerization initiator (B), The cationic polymerizable component (A) contains an oxetane compound (A1), an alicyclic epoxy compound (A2), and an epoxy compound other than the alicyclic epoxy compound (A2) (A3). The alicyclic epoxy compound (A2) contains at least one selected from the group consisting of 3',4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate, 3,4-epoxycyclohexylmethyl (3',4'-epoxy)cyclohexanecarboxylate, ε-caprolactone-modified 3',4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate, bis(3,4-epoxycyclohexyl)adipate, 1,2-epoxy-4-vinylcyclohexane, 1,4-cyclohexanedimethanol diglycidyl ether, epoxyethyldivinylcyclohexane, diepoxyvinylcyclohexane, 1,2,4-triepoxyethylcyclohexane, limonene dioxide, and (3,3',4,4'-diepoxy)bicyclohexyl. The ratio of the total amount of the oxetane compound (A1) and the alicyclic epoxy compound (A2) to the total amount of the cationic polymerizable component (A) is 70% by mass or more. The mass ratio of the epoxy compound (A3) to the total amount of the cationic polymerizable component (A) is greater than 0% by mass and less than 30% by mass. Resin composition for side filling.

2. The ratio of the photocationic polymerization initiator (B) to the total amount of the cationic polymerizable component (A) is 0.1% by mass or more and 10% by mass or less. The resin composition for side filling according to claim 1.

3. Further containing an inorganic filler (C), The resin composition for side filling according to claim 1 or 2.

4. The mass ratio of the inorganic filler (C) to the total amount of the side-fill resin composition is 10% by mass or more and 90% by mass or less. The resin composition for side filling according to claim 3.

5. The viscosity at 25°C is between 10 Pa·s and 2000 Pa·s. A resin composition for side filling according to any one of claims 1 to 4.

6. The device comprises a base material, a mounted component surface-mounted on the base material, and a side fill material interposed between the base material and the peripheral edge of the surface of the mounted component facing the base material. The side fill material consists of a cured product of the side fill resin composition described in any one of claims 1 to 5. Semiconductor equipment.

7. The semiconductor device according to claim 6 includes removing the side fill material from between the peripheral edge of the mounted component and the substrate while the side fill material is heated to 200°C or higher, How to remove side fill material.

8. A method for manufacturing a semiconductor device comprising a substrate, a mounted component surface-mounted on the substrate, and a side-fill material interposed between the substrate and the peripheral edge of the surface of the mounted component facing the substrate, The side fill material consists of a cured product of the side fill resin composition described in any one of claims 1 to 5. The process includes a coating step of applying the side-fill resin composition to the peripheral edge of the surface of the mounting component facing the substrate, and a curing step of curing the applied side-fill resin composition. The curing step includes irradiating the side-fill resin composition with light, A method for manufacturing a semiconductor device.

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