TW201523808A - Bottom filling material and method of manufacturing semiconductor device using same - Google Patents

Abstract

Provided is an underfill material capable of suppressing generation of voids and a method of manufacturing a semiconductor device using the same. The underfill material (20) is bonded in advance to the semiconductor wafer (10) on which the solder electrode is formed, and is mounted on the circuit substrate (30) on which the counter electrode facing the solder electrode is formed, and the semiconductor wafer ( 10) thermocompression bonding with the circuit substrate (30), the underfill material (20) containing an epoxy resin, an acid anhydride, an acrylic resin, and an organic peroxide, and the storage elastic modulus at the time of mounting is 3,000 Pa or more, and the lowest melt viscosity is reached. The temperature is below 125 °C.

Description

Underfill material and method of manufacturing semiconductor device using same

The present invention relates to an underfill material for mounting a semiconductor wafer, and a method of fabricating a semiconductor device using the same.

In recent years, in the semiconductor wafer mounting method, in order to shorten the steps, the industry is investigating the use of a pre-supply underfill film (PUF: Pre) on which an underfill film is attached to a semiconductor IC (Integrated Circuit) electrode. -applied Underfill Film)".

The mounting method using the pre-feed type underfill film is performed, for example, as follows (for example, refer to Patent Document 1).

Step A: attaching an underfill film to the wafer and performing dicing to obtain a semiconductor wafer.

Step B: Performing alignment of the semiconductor wafer on the substrate.

Step C: The semiconductor wafer is bonded to the substrate by high temperature and high pressure, the conduction is ensured by the metal bond of the bump bump, and the semiconductor wafer and the substrate are bonded by hardening of the underfill film.

In such a method, when a semiconductor wafer is mounted, it is easy to entrap a void, and the void remains after the thermocompression bonding. Moreover, even if there is no gap at the time of mounting, it takes a short time. In the pressure-bonding distribution of the temperature rise, there is also a case where a void is generated during the temperature rise.

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2005-28734

The present invention has been made in view of such conventional circumstances, and provides an underfill material capable of suppressing generation of voids and a method of manufacturing a semiconductor device using the same.

In order to solve the above problems, the present invention is a method in which a semiconductor wafer on which a solder electrode is formed is mounted on an electronic component in which a counter electrode opposed to the solder electrode is formed, and is bonded to an underfill of the semiconductor wafer in advance. The material is characterized in that it contains an epoxy resin, an acid anhydride, an acrylic resin, and an organic peroxide, and the storage elastic modulus at the time of mounting is 3,000 Pa or more, and the lowest melt viscosity reaches 125 ° C or lower.

Moreover, the method of manufacturing a semiconductor device according to the present invention includes the step of mounting a semiconductor wafer having a solder electrode formed thereon and having an underfill material bonded to the electrode surface, and the solder is formed on the electrode. An electronic component opposite to the opposite electrode of the electrode; and a thermocompression bonding step: thermocompression bonding the semiconductor wafer and the electronic component to a second temperature, wherein the underfill material comprises an epoxy resin, an acid anhydride, an acrylic resin, And the organic peroxide has a storage elastic modulus of 3,000 Pa or more at the first temperature and a minimum melt viscosity of 125 ° C or less.

According to the present invention, since the storage elastic modulus of the underfill material at the time of mounting is high and the lowest melt viscosity reaches a low temperature, voids at the time of mounting can be eliminated, and generation of voids at the time of thermocompression bonding can be suppressed.

1‧‧‧ wafer

2‧‧‧ underfill film

3‧‧‧ fixture

4‧‧‧blade

10‧‧‧Semiconductor wafer

11‧‧‧ Semiconductor

12‧‧‧ electrodes

13‧‧‧ solder

20‧‧‧ Underfill material

21‧‧‧ adhesive layer

30‧‧‧ circuit board

31‧‧‧Substrate

32‧‧‧ opposite electrode

Fig. 1 is a cross-sectional view schematically showing a semiconductor wafer and a circuit board before mounting.

Fig. 2 is a cross-sectional view schematically showing a semiconductor wafer and a circuit board during mounting.

Fig. 3 is a cross-sectional view schematically showing a semiconductor wafer and a circuit board after thermocompression bonding.

Fig. 4 is a flow chart showing a method of manufacturing the semiconductor device of the embodiment.

Fig. 5 is a perspective view schematically showing a step of attaching an underfill film to a wafer.

Fig. 6 is a perspective view schematically showing a step of cutting a wafer.

Fig. 7 is a perspective view schematically showing a step of picking up a semiconductor wafer.

Fig. 8 is a graph showing the crimp distribution of the embodiment.

Hereinafter, embodiments of the present invention will be described in detail in the following order.

Underfill material

2. Method of manufacturing a semiconductor device

3. Embodiment

<1. Underfill material>

In the underfill material of the present embodiment, when a semiconductor wafer on which a solder electrode is formed is mounted on an electronic component on which a counter electrode facing the solder electrode is formed, the semiconductor wafer is bonded to the semiconductor wafer in advance.

1 is a cross-sectional view schematically showing a semiconductor wafer and a circuit board before mounting, and FIG. 2 is a cross-sectional view schematically showing a semiconductor wafer and a circuit board during mounting, and 3 is a cross-sectional view schematically showing a semiconductor wafer and a circuit board after thermocompression bonding.

As shown in FIG. 1 to FIG. 3, the underfill material 20 of the present embodiment is used in advance to be bonded to the electrode surface of the semiconductor wafer 10 on which the solder electrode is attached, and the underlayer 21 is cured by the underfill material 20, The semiconductor wafer 10 is bonded to the circuit substrate 30 on which the counter electrode facing the solder electrode is formed.

The semiconductor wafer 10 has an integrated circuit formed on the surface of the semiconductor 11 such as germanium, and has a solder electrode for connection called a bump. The solder electrode is bonded to the electrode 12 made of copper or the like and has a thickness in which the thickness of the electrode 12 and the thickness of the solder 13 are combined.

As the solder, Sn-37Pb eutectic solder (melting point 183 ° C), Sn-Bi solder (melting point 139 ° C), Sn-3.5 Ag (melting point 221 ° C), Sn-3.0 Ag-0.5 Cu (melting point 217 ° C), Sn-5.0Sb (melting point 240 ° C) and the like.

The circuit board 30 is formed with a circuit on a base material 31 such as a rigid substrate or a flexible substrate. Further, a counter electrode 32 is formed on the mounting portion on which the semiconductor wafer 10 is mounted, and the counter electrode 32 has a specific thickness at a position facing the solder electrode of the semiconductor wafer 10.

The underfill material 20 contains a film forming resin, an epoxy resin, an acid anhydride, an acrylic resin, and an organic peroxide.

The film-forming resin corresponds to a high molecular weight resin having an average molecular weight of 10,000 or more, and is preferably an average molecular weight of about 10,000 to 80,000 from the viewpoint of film formability. As the film forming resin, various resins such as a phenoxy resin, an epoxy resin, a modified epoxy resin, and a urethane resin can be used. These film-forming resins may be used alone or in combination of two or more. Among these, a phenoxy resin is preferably used in the present embodiment from the viewpoint of film formation state, connection reliability, and the like.

Examples of the epoxy resin include a pentacyclopentadiene type epoxy resin, a glycidyl ether type epoxy resin, a glycidylamine type epoxy resin, a bisphenol A type epoxy resin, and a bisphenol F type epoxy resin. , bisphenol S type epoxy resin, spiral ring type epoxy resin, naphthalene type epoxy resin, biphenyl type epoxy resin, terpene type epoxy resin, tetrabromobisphenol A type epoxy resin, cresol novolac Type epoxy resin, phenol novolac type epoxy resin, α-naphthol novolac type epoxy resin, brominated phenol novolak type epoxy resin, and the like. These epoxy resins may be used alone or in combination of two or more. Among these, a pentacyclopentadiene type epoxy resin is preferably used in the present embodiment in terms of high adhesion and heat resistance.

The acid anhydride has a fluxing function of removing an oxide film on the surface of the solder, so that excellent connection reliability can be obtained. Examples of the acid anhydride include aliphatic acid anhydrides such as tetrapropenyl succinic anhydride and dodecenyl succinic anhydride; alicyclic acid anhydrides such as hexahydrophthalic anhydride and methyltetrahydrophthalic anhydride; and phthalic acid. An aromatic acid anhydride such as formic anhydride, trimellitic anhydride or pyromellitic dianhydride. These epoxy curing agents may be used alone or in combination of two or more. Among these epoxy hardeners, aliphatic acid anhydrides are preferably used in terms of solder connectivity in these.

Further, it is preferred to add a hardening accelerator. Specific examples of the curing accelerator include imidazoles such as 2-methylimidazole, 2-ethylimidazole, and 2-ethyl-4-methylimidazole, and 1,8-diazabicyclo (5,4,0). a tertiary amine such as undecene-7 salt (DBU salt) or 2-(dimethylaminomethyl)phenol; a phosphine such as triphenylphosphine; or a metal compound such as tin octylate.

As the acrylic resin, a monofunctional (meth) acrylate or a bifunctional or higher (meth) acrylate can be used. Examples of the monofunctional (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, and (methyl). ) n-butyl acrylate and the like. Examples of the bifunctional or higher (meth) acrylate include bisphenol F-EO. Modified di(meth)acrylate, bisphenol A-EO modified di(meth)acrylate, trimethylolpropane PO modified (meth)acrylate, polyfunctional (meth)acrylic acid amine Acid esters, etc. These acrylic resins may be used singly or in combination of two or more. Among these, in the present embodiment, a bifunctional (meth) acrylate is preferably used.

Examples of the organic peroxide include peroxyester, peroxyketal, hydrogen peroxide, dialkyl peroxide, dinonyl peroxide, and peroxydicarbonate. These organic peroxides may be used singly or in combination of two or more. Among these, in the present embodiment, a peroxyester is preferably used.

Moreover, as another additive composition, it is preferable to contain an inorganic filler. By containing an inorganic filler, the fluidity of the resin layer at the time of pressure bonding can be adjusted. As the inorganic filler, vermiculite, talc, titanium oxide, calcium carbonate, magnesium oxide, or the like can be used.

Further, a decane coupling agent such as an epoxy group, an amine group, a mercapto-thioether system or a urea group may be added as needed.

By using the epoxy-based epoxy resin which is relatively slow in the hardening reaction and the acrylic acid which is relatively fast in the hardening reaction, even when the pressure is applied under a short-time temperature-increasing distribution of 250 ° C within 10 seconds, the void can be prevented. produce.

Further, the storage elastic modulus when the underfill material is mounted is 3,000 Pa or more. Thereby, the gap at the time of mounting can be eliminated. The temperature at the time of mounting is preferably 30 ° C or more and is 30 ° C or less higher than the lowest melt viscosity of the underfill material, and more specifically, 30 ° C or more and 155 ° C or less.

Further, the minimum melt viscosity of the underfill material reaches a temperature of 125 ° C or less. Thereby, generation of voids at the time of thermocompression bonding can be suppressed. Minimum melting viscosity reaches the lowest melting temperature The melt viscosity is preferably 1000 Pa ‧ or more and 2000 Pa ‧ or less.

Next, a method of producing the pre-filled underfill film in which the underfill material is formed into a film shape will be described. First, an adhesive composition containing a film-forming resin, an epoxy resin, an acid anhydride, an acrylic resin, and an organic peroxide is dissolved in a solvent. As the solvent, toluene, ethyl acetate or the like, or a mixed solvent of these may be used. After the resin composition is prepared, it is applied onto a release substrate by a bar coater, a coating device, or the like.

The release substrate is composed of, for example, a laminated structure that prevents drying of the composition and maintains the shape of the composition. The laminate structure is applied to a PET (Poly Ethylene Terephthalate, polyethylene terephthalate). Ethylene diester), OPP (Oriented Polypropylene), PMP (Poly-4-methylpentene-1, poly-4-methylpentene-1), PTFE (Polytetrafluoroethylene, polytetrafluoroethylene).

Next, the resin composition applied to the release substrate is dried by a hot oven, a heating and drying device or the like. Thereby, a pre-feed type underfill film of a specific thickness can be obtained.

<2. Method of Manufacturing Semiconductor Device>

Next, a method of manufacturing a semiconductor device using the above-described pre-supply underfill film will be described.

Fig. 4 is a flow chart showing a method of manufacturing the semiconductor device of the embodiment. As shown in FIG. 4, the manufacturing method of the semiconductor device of this embodiment includes an underfill film attaching step S1, a dicing step S2, a semiconductor wafer mounting step S3, and a thermocompression bonding step S4.

Fig. 5 is a perspective view schematically showing a step of attaching an underfill film to a wafer. As shown in FIG. 5, the underfill film attaching step S1 is to fix the wafer 1 by attaching the jig 3 having a diameter larger than the diameter of the wafer 1 and having a ring-shaped or frame-like frame, and attaching the bottom to the wafer 1. fill Fill the film 2. The underfill film 2 protects and fixes the wafer 1 when the wafer 1 is diced, and functions as a dicing tape to be held at the time of picking up. Further, a large number of ICs (Integrated Circuits) are embedded in the wafer 1, and a solder electrode is disposed on the wafer 1 to the semiconductor wafer 10 which is divided by the scribe lines as shown in FIG.

Fig. 6 is a perspective view schematically showing a step of cutting a wafer. As shown in FIG. 6, the cutting step S2 presses the blade 4 along the scribe line to cut the wafer 1 and divides it into individual semiconductor wafers.

Fig. 7 is a perspective view schematically showing a step of picking up a semiconductor wafer. As shown in FIG. 7, each of the semiconductor wafers 10 with the underfill film is picked up while maintaining the underfill film.

As shown in FIG. 2, in the semiconductor wafer mounting step S3, the semiconductor wafer 10 with the underfill film and the circuit substrate 30 are placed via the underfill film. Further, the semiconductor wafer 10 with the underfill film is placed in such a manner that the solder electrodes are aligned with the counter electrode 32. Then, by heating the bonding machine, the underfill film is heated and pressed under the conditions of a specific temperature, pressure, and time to which fluidity is generated without causing the main hardening.

The temperature condition at the time of mounting is preferably 30 ° C or higher and the lowest melting viscosity of the underfill film is 30 ° C or less higher than the temperature, and more specifically, preferably 30 ° C or more and 155 ° C or less. Further, the pressure condition is preferably 50 N or less, more preferably 40 N or less. Further, the time condition is preferably 0.1 second or longer and 10 seconds or shorter, more preferably 0.1 second or longer and 1.0 second or shorter. Thereby, the solder electrode can be melted and brought into contact with the electrode on the circuit board 30 side, and the underfill film can be in a state in which it is not completely cured. Moreover, since the fixing is performed at a low temperature, generation of voids can be suppressed, and damage to the semiconductor wafer 10 can be reduced.

The following thermocompression bonding step S4 is performed by melting the solder of the solder electrode to form a metal bond under the bonding condition of raising the temperature from the first temperature to the second temperature at a specific temperature increase rate, and completely curing the underfill film.

Further, the temperature increase rate is preferably 50 ° C / sec or more and 150 ° C / sec or less. Further, the second temperature is also preferably 200 ° C or more and 280 ° C or less, more preferably 220 ° C or more and 260 ° C or less, depending on the type of the solder. Further, the time condition is preferably 5 seconds or longer and 500 seconds or shorter, more preferably 5 seconds or longer and 100 seconds or shorter. Thereby, the solder electrode and the substrate electrode can be metal-bonded, and the underfill film can be completely cured, and the electrode of the semiconductor wafer 10 and the electrode of the circuit substrate 30 can be electrically and mechanically connected.

Further, in the thermocompression bonding step S4, the bonding temperature of the bonding head to the underfill film after mounting is maintained at a constant height by the elastic modulus of the resin, and then the resin is melted and rapidly drops due to the temperature rise. , reaching the lowest point of the head. The lowest point is determined by the relationship between the rate of decrease of the head and the hardening speed of the resin. After the resin hardening is further carried out, the height of the head gradually rises as the resin and the head thermally expand. As described above, by lowering the bonding head to the lowest point in the time from the first temperature rise to the second temperature, generation of voids due to melting of the resin can be suppressed.

As described above, in the method of manufacturing the semiconductor device of the present embodiment, the underfill material 20 is bonded to the semiconductor wafer 10 on which the solder electrode is formed in advance, thereby eliminating voids during mounting and suppressing voids during heating and pressure bonding. The underfill material 20 contains an epoxy resin, an acid anhydride, an acrylic resin, and an organic peroxide. The storage modulus at the time of mounting is 3,000 Pa or more, and the lowest melt viscosity reaches 125 ° C or lower.

Furthermore, in the above embodiment, the underfill film is used as a dicing tape. However, the present invention is not limited thereto, and a dicing tape may be additionally used, and after the dicing, the underfill film is used for the flip chip mounting.

[Other Embodiments]

Further, the present technology can also be applied to a TSV (Through Silicon Via) technique in which a plurality of wafer substrates stacked in a sandwich shape are electrically connected by filling a metal hole in a semiconductor wafer.

That is, it is also applicable to a semiconductor in which a plurality of wafer substrates having a first surface on which a solder electrode is formed and a second surface on which a counter electrode facing the solder electrode is formed on the opposite side of the first surface are laminated. The manufacturing method of the device.

In this case, the second wafer substrate is mounted on the second surface of the second wafer substrate with the underfill film attached to the first surface of the first wafer substrate. Thereafter, the first surface of the first wafer substrate and the second surface of the second wafer substrate are thermocompression bonded at a temperature above the melting point of the solder with the solder electrode to obtain a semiconductor device in which a plurality of wafer substrates are laminated. .

[Examples]

<3. Example>

Hereinafter, embodiments of the invention will be described. In the present example, a pre-feed type underfill film was produced, and the storage modulus of the lowest melt viscosity reached and the mounting temperature (60 ° C) was measured. Then, an IC wafer having a solder electrode and an IC substrate having electrodes opposed thereto were connected using an underfill film to fabricate a package, and the voids were evaluated. Furthermore, the invention is not limited to the embodiments.

The measurement of the storage elastic modulus at the lowest melt viscosity reaching temperature and the mounting temperature, the production of the structure, and the evaluation of the voids were carried out as follows.

[Measurement of the lowest melt viscosity to the temperature and the storage elastic modulus at the mounting temperature]

For each underfill film, the lowest melt viscosity reaching temperature of the sample and the storage elastic modulus at the mounting temperature (60 ° C) were measured by a rheometer (ARES manufactured by TA Corporation) at 5 ° C/min and 1 Hz.

[Production of the body]

The underfill film was bonded to the wafer by a press at 50 ° C and 0.5 MPa, and dicing was performed to obtain an IC wafer having a solder-attached electrode.

The IC chip has a size of 7 mm, a thickness of 200 μm, and has bumps in the peripheral configuration ( In the case of 30 μm, 85 μm pitch, and 280 stitches, the peripherally disposed bumps were formed with a solder having a thickness of 16 μm (Sn-3.5Ag, melting point 221 ° C) at the electrode tip end made of Cu having a thickness of 20 μm.

Further, similarly to the opposing IC substrate, there is a bump having a size of 7 mm and a thickness of 200 μm and formed with an electrode made of Cu having a thickness of 20 μm ( 30 μm, 85 μm pitch, 280 pins).

Next, the IC wafer was mounted on the IC substrate by a flip chip bonding machine under conditions of 60 ° C, 0.5 second, and 30 N.

Thereafter, as in the pressure bonding distribution shown in Fig. 8, the temperature was raised from 60 ° C to 250 ° C in 10 seconds, and thermocompression bonding was performed by a flip chip bonding machine. Further, the bonding head was lowered to the lowest point (30 N) during the time from 60 ° C to 250 ° C. Further, it was cured at 150 ° C for 2 hours to obtain a package. Further, the temperature at which the flip chip bonding machine is used is obtained by measuring the actual temperature of the sample by a thermocouple.

[Evaluation of voids]

Each of the structures was observed by a SAT (Scanning Acoustic Tomograph), and the void was 1% or less of the area of the IC wafer, and the void was more than 1% of the area of the IC wafer.

[Example 1]

13.7 parts by mass of phenoxy resin (product name: PKHH, manufactured by Union Carbon Co., Ltd.), epoxy resin (product name: HP7200H, manufactured by Dainippon Ink Chemical Co., Ltd.) 23.3 parts by mass, acid anhydride (product name: MH-700, New Japan Physical and Chemical) Manufactured by the company, 13.7 parts by mass, imidazole (product name: 2MZ-A, manufactured by Shikoku Chemical Industry Co., Ltd.) 0.1 parts by mass, acrylic resin (product name: DCP, manufactured by Shin-Nakamura Chemical Co., Ltd.) 8.7 parts by mass, starting agent (product name: Perbutyl Z, manufactured by Nippon Oil & Fats Co., Ltd., 0.5 parts by mass, filler A (product name: SO-E5, manufactured by Admatechs Co., Ltd.), 35.0 parts by mass, and filler B (product name: Aerotech RY200, manufactured by Japan Aerotech Co., Ltd.), 5.0 parts by mass, and prepared The resin composition of the underfill film. It was applied to a peeled PET (Polyethylene terephthalate) by a bar coater, and dried in an oven at 80 ° C for 3 minutes to prepare an underfill film having a thickness of 50 μm (protective peeling PET (25 μm) / underfill film (50 μm). ) / substrate peeling PET (50 μm)).

The evaluation results of the underfill film of Example 1 are shown in Table 1. The lowest melt viscosity of the underfill film reached a temperature of 125 °C. Moreover, the storage elastic modulus at the mounting temperature was 3,300 Pa. Moreover, the evaluation of the void of the structure produced using the underfill film was ○.

[Embodiment 2]

13.7 parts by mass of phenoxy resin (product name: PKHH, manufactured by Union Carbon Co., Ltd.), epoxy resin (product name: HP7200H, manufactured by Dainippon Ink Chemical Co., Ltd.), 17.5 parts by mass, anhydride (product) Name: MH-700, manufactured by Nippon Chemical and Chemical Co., Ltd.) 10.3 parts by mass, imidazole (product name: 2MZ-A, manufactured by Shikoku Chemical Industry Co., Ltd.) 0.1 parts by mass, acrylic resin (product name: DCP, manufactured by Shin-Nakamura Chemical Co., Ltd.) 17.5 Parts, starting agent (product name: Perbutyl Z, manufactured by Nippon Oil & Fats Co., Ltd.) 0.9 parts by mass, filler A (product name: SO-E5, manufactured by Admatechs Co., Ltd.) 35.0 parts by mass, and filler B (product name: Aerotech RY200, Japan Ai Luoji The resin composition of the underfill film was prepared by 5.0 parts by mass of the company. It was applied to a peeled PET (Polyethylene terephthalate) by a bar coater, and dried in an oven at 80 ° C for 3 minutes to prepare an underfill film having a thickness of 50 μm (protective peeling PET (25 μm) / underfill film (50 μm). ) / substrate peeling PET (50 μm)).

The evaluation results of the underfill film of Example 2 are shown in Table 1. The lowest melt viscosity of the underfill film reached a temperature of 118 °C. Moreover, the storage elastic modulus at the mounting temperature was 3,300 Pa. Moreover, the evaluation of the void of the structure produced using the underfill film was ○.

[Example 3]

13.7 parts by mass of phenoxy resin (product name: PKHH, manufactured by Union Carbon Co., Ltd.), epoxy resin (product name: HP7200H, manufactured by Dainippon Ink Chemical Co., Ltd.), 18.3 parts by mass, acid anhydride (product name: MH-700, New Japan Physical and Chemical) Made by the company, 10.8 parts by mass, imidazole (product name: 2MZ-A, manufactured by Shikoku Chemical Industry Co., Ltd.) 0.1 parts by mass, acrylic resin (product name: DCP, manufactured by Shin-Nakamura Chemical Co., Ltd.) 6.8 parts by mass, starting agent (product name: Perbutyl Z, manufactured by Nippon Oil & Fats Co., Ltd., 0.4 parts by mass, filler A (product name: SO-E5, manufactured by Admatechs Co., Ltd.), 44.5 parts by mass, and filler B (product name: Ai Luoji RY200, manufactured by Japan Aerotech Co., Ltd.), 5.0 parts by mass, and prepared The resin composition of the underfill film. It was applied to a PET (Polyethylene terephthalate) by a bar coater, and dried in an oven at 80 ° C for 3 minutes to prepare a thickness of 50 μm. Underfill film (protective release PET (25 μm) / underfill film (50 μm) / substrate release PET (50 μm)).

The evaluation results of the underfill film of Example 3 are shown in Table 1. The lowest melt viscosity of the underfill film reached a temperature of 125 °C. Further, the storage elastic modulus at the mounting temperature was 4000 Pa. Moreover, the evaluation of the void of the structure produced using the underfill film was ○.

[Comparative Example 1]

13.7 parts by mass of phenoxy resin (product name: PKHH, manufactured by Union Carbon Co., Ltd.), epoxy resin (product name: HP7200H, manufactured by Dainippon Ink Chemical Co., Ltd.) 29.0 parts by mass, acid anhydride (product name: MH-700, New Japan Physical and Chemical) The company manufactures 17.1 parts by mass, imidazole (product name: 2MZ-A, manufactured by Shikoku Chemical Industry Co., Ltd.) 0.1 parts by mass, filler A (product name: SO-E5, manufactured by Admatechs) 35.0 parts by mass, and filler B (name: Ai The resin composition of the underfill film was prepared by 5.0 parts by mass of Logitech RY200, manufactured by Aerotech of Japan. It was applied to a peeled PET (Polyethylene terephthalate) by a bar coater, and dried in an oven at 80 ° C for 3 minutes to prepare an underfill film having a thickness of 50 μm (protective peeling PET (25 μm) / underfill film (50 μm). ) / substrate peeling PET (50 μm)).

Table 1 shows the evaluation results of the underfill film of Comparative Example 1. The lowest melt viscosity of the underfill film reached a temperature of 135 °C. Moreover, the storage elastic modulus at the mounting temperature was 3,300 Pa. Moreover, the evaluation of the void of the structure produced using the underfill film was ×.

[Comparative Example 2]

13.7 parts by mass of phenoxy resin (product name: PKHH, manufactured by Union Carbon Co., Ltd.), epoxy resin (product name: HP7200H, manufactured by Dainippon Ink Chemical Co., Ltd.) 25.9 parts by mass, acid anhydride (product name: MH-700, New Japan Physical and Chemical) Made by the company) 15.3 parts by mass, imidazole (product name: 2MZ-A, (manufactured by Shikoku Chemicals Co., Ltd.) 0.1 parts by mass, acrylic resin (product name: DCP, manufactured by Shin-Nakamura Chemical Co., Ltd.) 9.6 parts by mass, starting agent (product name: Perbutyl Z, manufactured by Nippon Oil Co., Ltd.) 0.6 parts by mass, filler A (product name) : SO-E5, manufactured by Admatechs Co., Ltd., 30.0 parts by mass, and a filler B (product name: Aerotech RY200, manufactured by Ai Luo Technology Co., Ltd.) in an amount of 5.0 parts by mass to prepare a resin composition of an underfill film. It was applied to a peeled PET (Polyethylene terephthalate) by a bar coater, and dried in an oven at 80 ° C for 3 minutes to prepare an underfill film having a thickness of 50 μm (protective peeling PET (25 μm) / underfill film (50 μm). ) / substrate peeling PET (50 μm)).

The evaluation results of the underfill film of Comparative Example 2 are shown in Table 1. The lowest melt viscosity of the underfill film reached a temperature of 125 °C. Moreover, the storage elastic modulus at the mounting temperature was 2,800 Pa. Moreover, the evaluation of the void of the structure produced using the underfill film was ×.

In Comparative Example 1, no void was observed after the wafer was mounted, but a void was observed after thermocompression bonding. Further, in Comparative Example 2, voids were observed after the wafer was mounted, and voids were also observed after thermocompression bonding. On the other hand, Examples 1 to 3 can suppress the generation of voids by using an underfill film containing an epoxy resin, an acid anhydride, an acrylic resin, and an organic peroxide, and the storage elastic modulus at the time of mounting is Above 3000Pa, the lowest melt viscosity reaches a temperature below 125 °C.

Claims (6)

An underfill material is preliminarily bonded to a semiconductor wafer in which a semiconductor wafer on which a solder electrode is formed is mounted on an electronic component on which a counter electrode facing the solder electrode is formed, and the underfill material contains The epoxy resin, the acid anhydride, the acrylic resin, and the organic peroxide have a storage elastic modulus of 3,000 Pa or more and a minimum melt viscosity of 125 ° C or less. The underfill material according to the first aspect of the patent application, wherein the temperature at the time of mounting is 30 ° C or more and 155 ° C or less. The underfill material of claim 1 or 2, wherein the epoxy resin is a cyclopentadiene type epoxy resin, and the acid anhydride is an aliphatic acid anhydride. The underfill material of claim 1 or 2, wherein the acrylic resin is a bifunctional (meth) acrylate, and the organic peroxide is a peroxyester. An underfill material according to claim 3, wherein the acrylic resin is a bifunctional (meth) acrylate, and the organic peroxide is a peroxyester. A method of manufacturing a semiconductor device, comprising: mounting a semiconductor wafer on which a solder electrode is formed at a first temperature and an underfill material is bonded to the electrode surface; and the pair is opposed to the solder electrode An electronic component to the electrode; and a thermocompression bonding step: the semiconductor wafer and the electronic component are heated to a second temperature for thermocompression bonding, The underfill material contains an epoxy resin, an acid anhydride, an acrylic resin, and an organic peroxide. The storage elastic modulus at the first temperature is 3,000 Pa or more, and the lowest melt viscosity reaches 125 ° C or lower.