TWI593768B - Film for package of pre-installed type semiconductor - Google Patents

Description

First set type semiconductor package film

The present invention relates to a film for a semiconductor sealing film which is provided first, and more specifically relates to a film for a semiconductor sealing film which is used first in flip chip bonding.

In recent years, the flip-chip bonding system has been used as a packaging method for a semiconductor wafer which is more dense and high-frequency in accordance with wiring such as a semiconductor device. In general, in flip chip bonding, a gap between a semiconductor wafer and a substrate is sealed with a material called an underfill.

In the conventional method, a flip-chip bonding is performed by bonding a semiconductor wafer and a substrate to a gap between a semiconductor wafer and a substrate, and filling an underfill of a thermosetting liquid sealing resin composition to form a semiconductor device. . In recent years, first, after the underfill is applied to the substrate, after the semiconductor wafer is loaded, the hardening of the underfill and the connection of the semiconductor wafer and the substrate are simultaneously performed, whereby the step and the hardening time can be shortened, and as a result, the curing time can be low. The supply-type flip-chip bonding process for manufacturing a semiconductor device at a low cost and low in energy is attracting attention, and the liquid sealing resin composition tending to review such a process (hereinafter referred to as a first supply type liquid sealing tree) Fat composition).

However, the flip chip bonding process using the first supply type liquid sealing resin composition has a problem that the first supply type liquid sealing resin composition overflows onto the semiconductor wafer. Fig. 1 is a schematic view for explaining a cross section of an overflow phenomenon in a flip chip bonding process using a first supply type liquid sealing resin composition. Fig. 1 is a view showing a semiconductor wafer 24 on which a bump 23 is formed by applying a supply-type liquid sealing resin composition 20 onto a substrate 21 on which a wiring 22 is formed. In this case, when the supply amount of the liquid-type sealing resin composition 20 is large, the overflow of the first supply-type liquid sealing resin composition 20 is generated on the side surface of the semiconductor wafer 24, and the overflow 20B is generated. The upper surface of the semiconductor wafer 24 overflows with the supply of the liquid sealing resin composition 20 to cause the overflow 20C.

In order to solve this problem, a method of encapsulating a film for a semiconductor sealing film using a first-prepared type liquid sealing resin composition (hereinafter referred to as a first-arrange type flip chip package) has been studied. In the pre-arranged flip-chip package, the supply amount of the film for the first-prepared semiconductor sealing is facilitated by controlling the supply amount of the film for the semiconductor sealing film of the first-prepared semiconductor sealing film control. In the film for semiconductor sealing of the first-preparation type, in addition to the characteristics generally used as the sealing material, flexibility is required, and it is not hardened at the time of preheating at, for example, 60 to 80 ° C for packaging flip chip. Further, the first type of flip chip package is the same as the first supply type, and a semiconductor device which is flipped with a low cost and low energy package can be fabricated.

As a component of the film for the first-prepared semiconductor sealing, it is considered to use an epoxy resin to meet the requirements of a general sealing material, and further, to use a latent The hardener is hardened after film formation. As an epoxy resin composition using a latent curing agent, Patent Document 1 discloses an activation of (A) an epoxy resin, (B) a thermoplastic resin soluble in an epoxy resin, and (C) activation at 70 to 90 ° C. An epoxy resin composition of a heat-curing latent curing agent. However, since the epoxy resin composition is activated by the latent curing agent at 70 to 90 ° C, the epoxy resin composition is hardened, and the film for the first-prepared semiconductor sealing cannot be used.

On the other hand, Patent Document 2 discloses a capsule type curing agent as a latent curing agent, which comprises a core containing an amine-based curing agent (A) and a capsule film covering the core, the capsule film comprising an amine-based hardening agent. The agent (A) is a cured product of an epoxy resin as a hardener. However, the capsule type hardener is intended to have high connection reliability, joint strength, and high sealing property even under low temperature or short-term hardening conditions (Patent Document 2, "Disclosure of Invention") The second to fifth lines are hardened when the pre-heating of the flip chip is used, so that the latent hardener which is a film for the first-prepared semiconductor encapsulation cannot be used.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. Hei 6-9758

[Patent Document 2] International Publication No. 2004/037885

The present invention provides a pre-conditioning for encapsulation It is not hardened when it is heated, and it is a problem that it can be used for the first-type semiconductor sealing film in the first type of flip chip package.

The present invention relates to a film for pre-installed semiconductor encapsulation which solves the above problems by having the following structure.

[1] A film for pre-installed semiconductor encapsulation characterized by comprising (A) a liquid epoxy resin, (B) a thermoplastic resin, (C) a hardener, and (D) a heat treatment at 50 to 100 ° C a hardening accelerator and (E) an inorganic filler.

[2] The film for pre-installed semiconductor encapsulation according to the above [1], wherein the component (B) is 10 to 30 parts by mass based on 100 parts by mass of the film for semiconductor sealing of the first type.

[3] The film for semiconductor sealing according to the above-mentioned [1], wherein the component (B) is 15 to 65 parts by mass based on 100 parts by mass of the total of the components (A) and (B).

[4] The film for pre-installed semiconductor encapsulation according to the above [1], wherein the component (D) is 2 to 5 parts by mass based on 100 parts by mass of the film for semiconductor sealing of the first type.

[5] The film for pre-installed semiconductor encapsulation according to the above [1], wherein the film (E) is 40 to 70 parts by mass based on 100 parts by mass of the film for semiconductor sealing of the first type.

[6] A semiconductor device produced by using the film for pre-installed semiconductor sealing described in the above [1].

According to the invention [1], a cover can be provided for use in packaging The crystal is not hardened during preheating, and is hardened when the package is flipped, and can be used for the first-prepared semiconductor sealing film which is provided in the flip chip package.

According to the invention [6], it is possible to obtain a semiconductor device which can be packaged by a conventionally mounted flip chip at a low cost and with low energy.

1, 2‧‧‧ semiconductor devices

10‧‧‧First-set semiconductor sealing film

10A, 30A‧‧‧ Hardened first-set semiconductor sealing film

11, 21, 31‧‧‧ substrates

12, 22‧‧‧ wiring

13, 23‧‧‧ protruding contacts

14, 24, 34‧‧‧ semiconductor wafer

20‧‧‧First supply liquid sealing resin composition

20B, 20C‧‧‧ spills

35‧‧‧Shear tool

Fig. 1 is a schematic view for explaining a cross section of a phenomenon of a spill in a flip chip bonding process using a first supply type liquid sealing resin composition.

Fig. 2 is a schematic view for explaining a cross section of a flip chip using a film for semiconductor encapsulation.

Fig. 3 is a view showing the results of DSC measurement of the component (D) used in Example 1.

Fig. 4 is a scanning electron micrograph of the cross section of Example 7.

Fig. 5 is a scanning electron micrograph of the cross section of Example 1.

Fig. 6 is a scanning electron micrograph of the cross section of Comparative Example 1.

Fig. 7 is a schematic view showing a method of evaluating the bonding strength between the substrate and the semiconductor wafer.

The film for semiconductor sealing according to the present invention (hereinafter referred to as a film for semiconductor sealing) is characterized by comprising (A) a liquid epoxy resin, (B) a thermoplastic resin, (C) a curing agent, and (D) 50 to 100. The potential hardening accelerator and the (E) inorganic filler which are heat treated at °C.

The component (A) can impart film hardenability, heat resistance, and bondability for semiconductor sealing, and can provide durability of the film for semiconductor sealing after curing. The component (A) may be a liquid bisphenol A epoxy resin, a liquid bisphenol F epoxy resin, a liquid naphthalene epoxy resin, a liquid aminophenol type epoxy resin, or a liquid biphenyl type. Epoxy resin, liquid hydrogenated bisphenol epoxy resin, liquid alicyclic epoxy resin, liquid alcohol ether epoxy resin, liquid cyclic aliphatic epoxy resin, liquid epoxy resin From the viewpoints of hardenability, heat resistance, jointability, and durability, liquid naphthalene type epoxy resin, liquid bisphenol F type epoxy resin, liquid bisphenol A type epoxy resin, liquid form are preferable. Aminophenol type epoxy resin and liquid biphenyl type epoxy resin. Further, the epoxy group equivalent of the component (A) is preferably from 80 to 250 g/eq from the viewpoint of reactivity and hardening density. Commercially available products are bisphenol A type epoxy resin (trade name: YD-128) manufactured by Nippon Steel Chemical Co., Ltd., bisphenol F type epoxy resin manufactured by Nippon Steel Chemical Co., Ltd. (trade name: YDF870GS), Mitsubishi Chemical Corporation Aminophenol-based epoxy resin (grade: JER630, JER630LSD), DIC-made naphthalene epoxy resin (trade name: HP4032D), Momentive Performance Materials Japan (product name: TSL9906) )Wait. The component (A) may be used singly or in combination of two or more.

The component (B) can impart flexibility to the film for semiconductor sealing. The component (B) can be exemplified by a phenoxy resin, a polyimide resin, a polyethylene resin, a polystyrene resin, a polyester, a polyether, a polydecylamine, a polyether ester decylamine, and a semiconductor seal based on slowing hardening. From the viewpoint of the internal stress of the film, a phenoxy resin is preferred. As used herein, a phenoxy resin is a method of directly reacting a divalent phenol with epichlorohydrin (also known as epichlorohydrin) or by a divalent phenol of diglycidyl ether and a divalent phenol. Polymer polyhydroxy polyether (thermoplastic resin) synthesized by addition polymerization, called weight average molecular weight More than 10,000 polymers. The weight average molecular weight is preferably from 10,000 to 100,000, more preferably from 40,000 to 80,000. As used herein, the weight average molecular weight is a standard curve of standard polystyrene via gel permeation chromatography (GPC).

The divalent phenols may be exemplified by bisphenol A, bisphenol F, bisphenol S, dihydroxynaphthalene, bisphenol D, bisphenol E, bisphenol Z, bisphenol oxime, biscresol oxime, biphenol, ortho-benzene. Halogenated bisphenols such as phenol, resorcinol, hydroquinone, 2,5-di-t-butylhydroquinone, or brominated bisphenol A; 10-(2,5-dihydroxyphenyl)-10-di Hydrogen-9-oxa-10-phosphinophen-10-oxide, 10-(2,7-dihydroxynaphthyl)-10-dihydro-9-oxa-10-phosphinophen-10-oxide, Diphenylphosphinylhydroquinone, diphenylphosphinylnaphthoquinone, cyclooctylphosphinyl-1,4-benzenediol, or cyclooctenylphosphinyl-1,4-naphthalenediol The phenoxy resin, etc., may be exemplified by a direct reaction of the divalent phenols with epichlorohydrin, or by the above-mentioned divalent phenols and diphenols of the phenols. The synthesis of an ether compound by addition polymerization. The component (B) is more preferably a bisphenol A type phenoxy resin, a bisphenol F type phenoxy resin, or a bisphenol A-bisphenol F copolymerization type phenoxy resin. When the component (B) is a phenoxy resin, it is considered that the internal stress of the film for the first-prepared semiconductor sealing after hardening is slowed down, so that the pressure between the semiconductor wafer and the substrate is slowed down, and the semiconductor wafer-substrate is present ( B) ingredients to improve fit. A commercially available product of the component (B) is phenoxy resin (trade name: YP-50S) manufactured by Nippon Steel Chemical Co., Ltd., and the like. The component (B) may be used singly or in combination of two or more.

The component (C) may be any one having the curing ability of the component (A), and the component (C) may be a phenolic curing agent, an amine curing agent or an acid anhydride system. The curing agent is preferably a phenolic curing agent from the viewpoint of reactivity and stability. The phenolic curing agent may, for example, be a phenol novolac resin or a cresol novolac resin, and is preferably a phenol novolak resin. The amine-based curing agent may, for example, be a chain aliphatic amine, a cyclic aliphatic amine, a fatty aromatic amine or an aromatic amine, and is preferably an aromatic amine. Examples of the acid anhydride-based curing agent include tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methyl nadic anhydride, hydrogenated methyl nadic anhydride, and three. Alkyl tetrahydrophthalic anhydride, methylcyclohexene tetracarboxylic acid dianhydride, phthalic anhydride, trimellitic anhydride, pyromellitic dianhydride, diphenyl ketone tetracarboxylic dianhydride , ethylene glycol diphenyl trimellitic anhydride, glycerol bis(benzene trimellitic anhydride) monoacetate, dodecene succinic anhydride, aliphatic dibasic polybasic acid anhydride, chlorendic anhydride, methylbutenyl Tetrahydrophthalic anhydride, alkylated tetrahydrophthalic anhydride, methyl himic anhydride, alkenyl substituted succinic anhydride, glutaric anhydride, etc., preferably methylbutenyltetrahydrophthalic anhydride. Commercially available products include a phenol resin hardener (trade name: KA-1160), a phenolic hardener (trade name: MEH8000, MEH8005) manufactured by Minghe Chemical Co., Ltd., and an amine hardener made from Nippon Chemical Co., Ltd. (trade name: Kayahard AA), an anhydride of Mitsubishi Chemical (grade: YH306, YH307), 3-methyl-hexahydrophthalic anhydride or 4-methyl-hexahydrophthalic anhydride (trade name: HN-5500) manufactured by Hitachi Chemical Co., Ltd. . The component (C) may be used singly or in combination of two or more.

By the component (D), the semiconductor sealing film can be hardened during the preheating for the package flip chip, and the semiconductor can be sealed during the package flip chip. Hardened with a film. In this context, the latent hardening accelerator is a shell with an amine ester resin or the like, and the hardening accelerator is a core and microencapsulated, although it is a master batch with an epoxy resin. However, it is still preferable from the viewpoints of workability, hardening speed, and preservation stability. The chiral urethane resin is considered to be moderately polymerized by heat-treating the latent curing accelerator which has been subjected to the masterbatch of the epoxy resin at 50 to 100 °C. When the heat treatment temperature of the latent hardening accelerator is less than 50 ° C, the stability during preheating and the connectivity of the flip chip package may be insufficient; when the heat treatment temperature of the latent hardening accelerator exceeds 100 ° C, it may result in The masterbatch of epoxy resin and latent hardening accelerator is semi-hardened or hardened. The heat treatment temperature of the component (D) is preferably from 60 to 100 ° C, more preferably from 70 to 100 ° C, still more preferably from 70 to 90 ° C.

The heat treatment time of the component (D) is preferably from 6 to 72 hours. Further, when the heat treatment temperature of the component (D) is 50 ° C, it is preferably 48 hours or longer, and when the heat treatment temperature of the component (D) is 100 ° C, it is preferably 48 hours or shorter, more preferably 12 hours or shorter.

Further, the reaction starting temperature of the component (D) is preferably from 110 to 150 ° C, more preferably from 120 to 142 ° C. Herein, the reaction initiation temperature is measured by DSC (differential scanning calorimetry). Herein, the reaction initiation temperature means the temperature at which the (D) component is in the film for semiconductor sealing, the latent curing agent causes the hardening reaction to start, and in the DSC, the temperature at which the component (D) starts to heat is observed.

The latent curing accelerator is preferably a microencapsulated imidazole compound hardening accelerator such as an amine ester resin, and is preferably dispersed in the viewpoint of workability, curing speed, and storage stability. In the liquid epoxy resin such as liquid bisphenol A type, the masterbatch microencapsulated imidazole compound hardening accelerator. Examples of the imidazole hardener include 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4- Methylimidazole, 2,4-diamino-6-[2'-methylimidazolyl-(1')]ethyl-s-three , 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2,3-dihydro-1H-pyrrolo[1,2-a Benzimidazole or the like, and based on the hardening speed, workability, and moisture resistance, 2,4-diamino-6-[2'-methylimidazolyl-(1')]ethyl- is preferred. S-three 2,4-Diamino-6-[2'-undecylimidazolyl-(1)-ethyl-s-three 2,4-Diamino-6-[2'-ethyl-4-methylimidazolyl-(1')1-ethyl-s-three Wait.

A commercially available product of a latent curing accelerator which is an epoxy resin masterbatch includes a microencapsulated imidazole compound hardener manufactured by Asahi Kasei E-materials (trade name: NOVACURE4982 (very thick type), NOVACURE3932 (medium thick type) ), NOVACURE 4921 (thin type), HX3722, HXA3932HP), etc., preferably a microencapsulated imidazole compound hardener (trade name: NOVACURE 4982 (very thick type)) manufactured by Asahi Kasei E-materials. In this paper, the extremely thick type is a latent hardening accelerator with a gelation temperature of 140 to 150 ° C, the medium thick type is a latent hardening accelerator with a gelation temperature of 100 to 110 ° C, and the thin type gelatinization temperature is 70 to A latent hardening accelerator at 80 °C. The gelation temperature was measured at a temperature at which the gelation time was less than 5 minutes in accordance with JIS K5600-9-1. The component (D) may be used singly or in combination of two or more.

The elastic modulus and thermal expansion coefficient of the film for semiconductor sealing after curing can be adjusted by the component (E). (E) component can be cited as citric acid gum (colloidal silica), hydrophobic cerium oxide, fine cerium oxide, nano cerium oxide, etc. silica filler; aluminum nitride, aluminum oxide, tantalum nitride, boron nitride, based on versatility, electronic properties From the viewpoint of the like, a cerium oxide filler is preferred. In addition, the average particle diameter of the component (E) (the average maximum diameter in the case of non-granularity) is not particularly limited, but is preferably 0.05 to 50 μm, and it is preferred to uniformly disperse the filler in the film for semiconductor sealing. When the thickness is less than 0.05 μm, the viscosity of the film for semiconductor sealing increases during packaging, and there is a concern that the fluidity is deteriorated. When it exceeds 50 μm, it becomes difficult to uniformly deposit the filler in the film for semiconductor sealing, and it is difficult to connect the semiconductor to the substrate. The average particle diameter of the component (E) is more preferably from 0.1 to 30 μm, still more preferably from 0.1 to 5 μm. Commercially available products include: cerium oxide manufactured by ADMATECHS (product name: SO-E2, average particle diameter: 0.5 μm), cerium oxide manufactured by DENKA (trade name: FB-5D, average particle diameter: 5 μm), hibiscus chemistry Industrial production (product name: SP03B, average particle diameter: 300 nm), etc. In this paper, the average particle size of the component (E) is measured by a dynamic light scattering type nano-track particle size analyzer. (E) component can be separately Two or more of these may be used in combination.

The film for semiconductor encapsulation preferably contains 7 to 30 parts by mass of the component (B), and more preferably 10 to 30 parts by mass, based on 100 parts by mass of the film for semiconductor sealing. When the amount is 7 parts by mass or more, the flexibility of the film for semiconductor encapsulation is sufficient, and when it is 30 parts by mass or less, the film for semiconductor encapsulation has sufficient flexibility. When it is 30 parts by weight or more, the semiconductor sealing film is liable to become brittle, and it becomes difficult to maintain a flexible film shape.

In addition, the component (B) of the semiconductor sealing film is preferably 15 to 65 in terms of 100 parts by mass of the total of the components (A) and (B). The amount is preferably from 15 to 55 parts by mass. When the amount is 15 parts by mass or more, the flexibility of the film for semiconductor encapsulation is sufficient, and when it is 65 parts by mass or less, the film for semiconductor encapsulation has sufficient flexibility.

The hardener equivalent of the component (C) is preferably from 0.1 to 1.1 times the epoxy equivalent of the component (A). When the amount is less than 0.1, the hardening of the component (A) tends to be insufficient, and the bonding tends to become insufficient. Insufficient. On the other hand, when the hardener equivalent of the component (C) exceeds 1.1 times, the hardening of the component (A) tends to be insufficient, and voids are likely to occur. Further, the curing agent equivalent of the component (C) is preferably from 0.1 to 0.5 times the functional group equivalent of the component (B), and when it is less than 0.1 times, the curing tends to be insufficient, and when it exceeds 0.5 times, it is liable after hardening. It is hard and brittle. Based on the above, the hardener equivalent of the component (C) is preferably 0.2 to 1.6 times the total amount of the epoxy group equivalent of the component (A) and the functional group equivalent of the component (B). In the present invention, the curing agent equivalent of the component (C) is, for example, a phenol equivalent in the case where the component (C) is a phenol-based curing agent, an amine equivalent in the case of an amine-based curing agent, and an acid anhydride equivalent in the case of an acid-based curing agent.

In order to cure the film for semiconductor encapsulation without pre-heating the film for flip chip coating, the film for semiconductor encapsulation is cured at the time of encapsulation, and the component (D) is preferably 100 parts by mass with respect to the film for semiconductor encapsulation. It is 2 to 5 parts by mass. Further, when the latent hardener is mastered with the epoxy resin, the preferred component of the component (D) is to calculate the amount of the latent hardener in the masterbatch.

The component (E) is preferably 30 to 80 parts by mass, more preferably 40 to 70, in terms of the modulus of elasticity and the coefficient of thermal expansion of the film for semiconductor sealing after curing. Parts by mass.

In the film for semiconductor sealing, an ion trapping agent for preventing wiring or protruding contact migration, a rosin-based flux, an acid anhydride system, and an anthraquinone system can be further added as needed within the scope of the object of the present invention. A flux such as a carboxylic acid; a coupling agent such as a decane coupling agent; a pigment such as carbon black; a dye, an antifoaming agent, an antioxidant, a leveling agent, a thixotropy, a pressure reducing agent, and other additives. Based on the point of view of concealment, it is particularly preferable to add carbon black. Moreover, it is preferable to contain no organic solvent, especially an organic solvent which does not contain a low boiling point, from the viewpoint of suppressing the void at the time of a package-molding.

The thickness of the film for semiconductor sealing is preferably from 10 to 100 μm from the viewpoint of the gap between the flip chip and the substrate, and the height of the bump of the semiconductor wafer and the height of the wiring of the substrate.

The film for semiconductor sealing preferably has a melt viscosity of 10,000 to 40,000 PA from the viewpoint of suppressing the void at the time of bonding and suppressing the void at the time of sealing the package. s.

A film-forming composition for semiconductor sealing is applied onto a support, and the film is dried to form a film for semiconductor sealing. The support may be exemplified by a polyethylene terephthalate (PET) film or the like.

The composition for forming a film for semiconductor sealing can be obtained by stirring, melting, mixing, and dispersing the components (A) to (E) and other additives at the same time or separately as needed. The apparatus for mixing, stirring, dispersing, and the like is not particularly limited, and a mincer having a stirring and heating device, a triple roll mill, a ball mill, and a planetary mixer may be used. Planetary mixer) (beads mill) and so on. Further, these devices may be used in combination as appropriate.

The method of applying the composition for forming a film for semiconductor encapsulation on the support is not particularly limited. However, it is preferably a micro-gravure method, a slot die method, or a doctor blade based on the thickness of the film and the thickness of the film. Blade) method.

The drying conditions of the film-forming composition for semiconductor sealing applied to the support can be appropriately set depending on the coating thickness and the like, and can be, for example, about 60 to 120 ° C for about 1 to 30 minutes. The film for semiconductor sealing obtained in this way is in an unhardened state.

Fig. 2 is a schematic view for explaining a cross section of a flip chip package using a film for semiconductor encapsulation. As shown in the second (A) diagram, first, the substrate 11 on which the wiring 12 is formed is prepared. Next, as shown in FIG. 2(B), the semiconductor sealing film 10 is provided on the substrate 11 on which the wiring 12 is formed, and is preheated. Thereafter, as shown in Fig. 2(C), the position of the protruding contact 13 formed on the semiconductor wafer 14 is aligned so as to correspond to the wiring 12 on the substrate 11. Herein, the wiring 12 and the protruding contact 13 are formed together to form a solder layer on the surface. Finally, as shown in FIG. 2(D), after the wiring 12 on the substrate 11 is brought into contact with the protruding contacts 13 on the semiconductor wafer 14, the wiring 12 on the substrate 11 and the semiconductor wafer 14 are heated. The output contact 13 is subjected to solder bonding while curing the film for semiconductor sealing. The film for semiconductor sealing is made into the film 16A for the pre-installed semiconductor sealing which has been hardened.

The hardening at the time of flip chip mounting of the film for semiconductor encapsulation is preferably carried out at 180 to 300 ° C for 5 to 30 seconds, and it is particularly preferable to harden it within 15 seconds from the viewpoint of improving productivity.

Thereby, the film for pre-installed semiconductor encapsulation of the present invention does not harden during preheating for encapsulating the flip chip, and is hardened when the package is flipped, so that it can be used for the pre-disposable flip chip package. Furthermore, a heating step may be added after packaging to promote hardening of the semiconductor sealing film.

(Example)

The present invention has been described by way of examples, but the invention is not limited thereto. Further, in the following examples, the parts by mass and the % by mass are not limited unless otherwise limited.

[Examples 1 to 21, Comparative Examples 1 to 5, and Reference Examples 1 to 2]

The composition for forming a film for semiconductor sealing was adjusted in the manner shown in Tables 1 to 3. After mixing the components (A) to (D), the component (E) is mixed with methyl ethyl ketone to obtain a film-forming composition for semiconductor sealing. The obtained composition for forming a film for semiconductor encapsulation was applied by a doctor blade, and then dried to obtain a film for semiconductor sealing having a thickness of 50 μm. Further, Tables 1 to 3 show the reaction starting temperatures of the component (D) measured by DSC (model: DSC204 F1 Phoenix) manufactured by NETZSCH. Further, in Table 3, in Comparative Examples 4 and 5 in which imidazole was used instead of the component (D), the activity starting temperature of imidazole was indicated in the column of the reaction initiation temperature or the activity starting temperature. As used herein, the activity onset temperature refers to the temperature at which the imidazole monomer is activated, as measured by the temperature at which DSC begins to heat up. Fig. 3 is a graph showing DSC measurement results of the component (D) used in Example 1. The broken line in Fig. 3 indicates the reference line. As is apparent from Fig. 3, the starting temperature of the component (D) used in Example 1 was 110 °C.

Assessment of stability when setting first

In order to evaluate the stability in the first setting of the flip chip package, the lowest melt viscosity (initial minimum melt viscosity) of the film for semiconductor sealing was measured by VAR100 manufactured by Visco analyser. Next, the lowest melt viscosity after maintaining at 70 ° C for 3 hours was measured in the same manner. The stability at the first setting (unit: %) was obtained by the following formula: (stability at the time of setting first) = (the lowest melt viscosity after 3 hours) / (the lowest melt viscosity at the beginning) × 100. If the stability at the time of setting is 160% or less, it is good. Tables 1 to 3 show the results of the evaluation of the stability at the time of setting.

Evaluation of the connectivity of the wiring on the substrate to the bump contacts on the semiconductor wafer

An Si wafer having a width of 7 mm, a length of 7 mm, and a thickness of 125 μm was prepared, and 544 protruding contacts of 30 μm with a pitch of 50 μm were formed on the wafer. The male contacts are soldered to the protruding contacts of the Cu pillar. Further, an epoxy epoxy glass substrate having a wiring corresponding to the bump contact pattern of the germanium wafer and having a substrate thickness of 350 μm was prepared. The semiconductor sealing film was placed on the substrate having the wiring described above, and preheated at 70 °C. On the pre-heated substrate, using a flip chip bonder, the bump contacts on the Si wafer were brought into contact with the wiring on the substrate for 1.2 seconds at a load of 30 N, 200 ° C, and then the temperature was raised and maintained at 280 ° C. After the second, it was cooled to 200 ° C and taken out from the flip chip bonder to prepare an evaluation sample. The resistance value of the bump contact on the Si wafer and the wiring on the substrate was measured by a universal meter (Model: HP34401A) manufactured by Agilent Technologies. Value), the case where the resistance value is less than 1.1 times the design value is "◎", and the design value is 1.1 times or more and the measurement range of the measuring device is "○", which cannot be measured because it is outside the measuring range of the measuring device. The situation is "X". In this paper, the design value of the resistance value is 29Ω. Tables 1 to 3 show the results of evaluation of the connectivity between the wiring on the substrate and the bump contact on the semiconductor wafer (the connection is described as connectivity).

Fig. 4 is a scanning electron micrograph of the cross section of Example 7. Fig. 5 is a scanning electron micrograph of the cross section of Example 1. Fig. 6 is a scanning electron micrograph of the cross section of Comparative Example 1. Fig. 4 shows the case where the result of the connectivity evaluation is "◎", the fifth picture shows the case of "○", and the sixth picture shows the case of "x". In Fig. 6, a film for semiconductor sealing remains between the wiring on the substrate and the bump contact on the semiconductor wafer.

Evaluation of void generation rate

The evaluation of the void generation rate was performed by measuring the evaluation sample prepared by evaluating the connection between the wiring on the substrate and the bump contact on the semiconductor wafer by an ultrasonic microscope. The void generation rate (unit: %) was determined by the following formula: (void generation rate) = (void area) / (wafer area) × 100. Tables 1 to 3 show the results of evaluation of the void generation rate.

Evaluation of bonding strength between substrate and semiconductor wafer

Evaluation samples made to evaluate the connectivity of the wiring on the substrate to the bump contacts on the semiconductor wafer were used. Fig. 7 is a schematic view showing a method of evaluating the bonding strength between the substrate and the semiconductor wafer. An FR-4 substrate which was dried at 150 ° C for 20 minutes was prepared as the substrate 31, and a Si wafer to which a 2 mm square SiN film was attached was prepared as the semiconductor wafer 34. A film for semiconductor sealing of 1 mm square is placed on the substrate 31, and a semiconductor wafer 34 is mounted on the film for semiconductor sealing. Thereafter, the film for semiconductor sealing was cured at 160 ° C for 60 minutes to form a cured film for semiconductor sealing 30A. The shear strength (unit: N/mm ² ) was measured using a table strength tester (model: 1605HTP) manufactured by AIKOH ENGINEERING. When the shear strength is 3.0 N/mm ² or more, it is good. Tables 1 to 3 show the results of evaluation of the shear strength of the substrate and the semiconductor wafer (the joint strength is described in the table).

Summarizing the experimental results, the stability of all of Examples 1 to 21, the connection between the wiring on the substrate and the bump contact on the semiconductor wafer, the void generation rate, and the evaluation results of the bonding strength between the substrate and the semiconductor wafer were summarized. All are good. In particular, in Examples 2 to 18 and 20, the evaluation results of the connection between the wiring on the substrate and the protruding contact on the semiconductor wafer were very good. On the other hand, Comparative Example 1 in which the latent curing accelerator was heat-treated at 40° C. had poor stability and connectivity at the time of first setting; Comparative Example 2 in which the latent curing accelerator was heat-treated at 110° C., in the heat treatment ring In the case of the masterbatch of the oxygen resin and the latent curing agent, the master batch is semi-hardened, so that the film forming composition for semiconductor sealing cannot be mixed. In Comparative Example 3, which used a latent curing accelerator which was not heat-treated, the stability and the connectivity were poor at the time of first setting. In Reference Example 1, when the master batch of the epoxy resin and the latent curing agent was heat-treated, the master batch was hardened, and thus the film forming composition for semiconductor sealing could not be mixed. Comparative Example 4 using imidazole 1 in place of (D) component has a high void generation rate. The wiring on the substrate of Comparative Example 5 in which the imidazole 2 was used instead of the (D) component was not well connected to the protruding contact on the semiconductor wafer, and the semi-hardening was evaluated in the evaluation test of the stability at the time of the first setting. The latent curing agent which was subjected to heat treatment at 50 ° C for 12 hours as the component (D) was poorly set in stability and connectivity.

The film for pre-installed semiconductor encapsulation of the present invention does not harden when it is used for preheating of the package flip chip, but is hardened when the package is flipped, and can be used for the pre-disposable flip chip package. Therefore, by using the film for pre-installed semiconductor encapsulation of the present invention, it is possible to obtain a semiconductor device manufactured by low-cost, low-energy package-first type flip chip.

Since the drawing of this case is a diagram illustrating the phenomenon of spillage, the mode diagram of the implementation, the measurement results of the embodiment, the evaluation method and the photograph, which are not sufficient to represent the technical features of the case, there is no representative representative figure in this case.

Claims (6)

A film for pre-installed semiconductor sealing comprising (A) a liquid epoxy resin, (B) a thermoplastic resin, (C) a curing agent, (D) a latent curing accelerator which is heat-treated at 50 to 100 ° C, and (E) Inorganic filler. The film for a semiconductor sealing film according to the first aspect of the invention, wherein the film for the semiconductor sealing film of the first type is 100 parts by mass, and the component (B) is 10 to 30 parts by mass. The film for a semiconductor sealing film according to the first aspect of the invention, wherein the total amount of the component (A) and the component (B) is 100 parts by mass, and the component (B) is 15 to 65 parts by mass. The film for a semiconductor sealing film according to the first aspect of the invention, wherein the film for the semiconductor sealing film of the first type is 100 parts by mass, and the component (D) is 2 to 5 parts by mass. The film for a semiconductor sealing film according to the first aspect of the invention, wherein the film for the semiconductor-sealing type is 100 parts by mass, and the component (E) is 40 to 70 parts by mass. A semiconductor device manufactured by using the film for pre-installed semiconductor sealing described in claim 1 of the patent application.