Electroconductive die attach film, dicing die attach film, and method for mounting semiconductor chip

Abstract

Provided are an electroconductive die attach film, a dicing die attach film, and a method for mounting a semiconductor chip, with which it is possible to suppress curing shrinkage at the time of thermal curing and, consequently, to highly reliably bond the semiconductor chip and a lead frame or other substrate.　This electroconductive die attach film comprises metal-coated resin particles and a thermosetting resin as essential components, wherein: the volume fraction of the metal-coated resin particles is 40 vol% or higher; and the curing shrinkage rate defined by 1 − ρInit / ρT is 0.03 or lower, where ρInit is the density of the electroconductive die attach film before heat treatment, and ρT is the density of the electroconductive die attach film after heat treatment at 150°C × 1 h.

Description

Conductive die attach film, dicing die attach film, and method for mounting semiconductor chips

[0001] The present invention relates to a conductive die attach film, a dicing die attach film, and a method for mounting semiconductor chips.

[0002] For example, as disclosed in Patent Documents 1 and 2, conductive adhesives combining epoxy resin and conductive metal particles such as silver particles are commonly used as adhesives for bonding semiconductor chips to substrates such as lead frames. In recent years, conductive die-attach films, which are formed from the same components as these conductive adhesives, have also come into use.

[0003] JP-A No. 60-124615 JP-A No. 62-275180

[0004] However, conventional conductive adhesives and conductive die attach films had the property of curing shrinkage during thermal curing. Due to the residual stress caused by this curing shrinkage, the bonding interface between the semiconductor chip and the conductive adhesive or conductive die attach film sometimes delaminated in reliability evaluations such as MSL (Moisture Sensitivity Level (corresponding standard: IPC / JEDEC J-STD-020)) and TCT (Thermal Cycle Test (corresponding standard: MIL-STD-883G, etc.)). In particular, semiconductor chips with backside metallization treatment and lead frames with at least one of PPF (Pre-Plated Leadframe, Pre-Plated Frame) plating or gold plating are difficult to bond, and when attempting to bond them with conductive adhesives or conductive die attach films, the bonding interface easily delaminates, resulting in low reliability.

[0005] The present invention was made to solve the above problems, and its objective is to provide a conductive die attach film, a dicing die attach film, and a semiconductor chip mounting method that suppress curing shrinkage during thermal curing and, consequently, enable highly reliable bonding of a semiconductor chip to a substrate such as a lead frame.

[0006] As a result of diligent research by the present inventors, a conductive die attach film comprising metal-coated resin particles (A) and a thermosetting resin (B) as essential components, wherein the volume fraction of the metal-coated resin particles is 40 vol% or more, and the density of the conductive die attach film before heat treatment is ρ Ｉｎｉｔ The density of the conductive die attach film after heat treatment at 150°C for 1 hour is ρ Ｔ In that case, 1 - ρ Ｉｎｉｔ / ρ Ｔ We have found that the above problems can be solved by a conductive die-attach film having a curing shrinkage rate of 0.03 or less, as defined by [a specific formula]. According to one aspect of the present invention, the following invention is provided.

[0007] (1) A conductive die attach film comprising metal-coated resin particles and a thermosetting resin as essential components, wherein the volume fraction of the metal-coated resin particles is 40 vol% or more, and the density of the conductive die attach film before heat treatment is ρ Ｉｎｉｔ The density of the conductive die attach film after heat treatment at 150°C for 1 hour is ρ Ｔ In that case, 1 - ρ Ｉｎｉｔ / ρ Ｔ A conductive die attach film having a curing shrinkage rate of 0.03 or less, as defined by [a specific formula / method].

[0008] (2) The conductive die attach film according to (1), wherein the thermosetting resin comprises at least one epoxy resin and a phenoxy resin having a naphthalene skeleton, and an imidazole-based curing catalyst.

[0009] (3) The conductive die attach film according to (1) or (2), wherein the thermosetting resin comprises at least one epoxy resin and a phenoxy resin having a bisphenol F skeleton.

[0010] (4) The conductive die attach film according to any one of (1) to (3), wherein the thermosetting resin comprises at least one of an epoxy resin having a polyether skeleton and a phenoxy resin.

[0011] (5) The conductive die attach film according to any one of (1) to (4), wherein a resin core portion constituting the metal-coated resin particles contains at least one of an acrylic resin and a crosslinked acrylic resin.

[0012] (6) The conductive die attach film according to any one of (1) to (5), wherein a metal layer portion constituting the metal-coated resin particles contains at least one of silver and copper.

[0013] (7) The conductive die attach film contains metal particles separately from the metal-coated resin particles, and average particle diameters d of the metal-coated resin particles and the metal particles measured by a diffraction particle size distribution meter ５０ are different from each other, the conductive die attach film according to any one of (1) to (6).

[0014] (8) A dicing die attach film, which is a combination of the conductive die attach film according to any one of (1) to (7) and a dicing tape.

[0015] (9) A method for mounting a semiconductor chip, comprising: electrically connecting a semiconductor chip having a back surface metallized treatment to a substrate having at least one of PPF plating and gold plating applied on a surface thereof via the conductive die attach film according to any one of (1) to (7).

[0016] According to one aspect of the present invention, curing shrinkage during thermosetting is suppressed, and as a result, a semiconductor chip and a substrate can be bonded with high reliability.

[0017] These are explanatory diagrams showing a method for mounting a semiconductor chip using the conductive die attach film according to the present embodiment, an explanatory diagram showing a semiconductor element according to the present embodiment, and a cross-sectional SEM photograph of the conductive die attach film according to the present embodiment.

[0018] The following embodiments for carrying out the conductive die attach film, dicing die attach film, and semiconductor chip mounting method according to the present invention are illustrated with drawings. The embodiments illustrated below are for the purpose of facilitating understanding of the present invention and are not intended to limit the interpretation of the present invention. The present invention can be modified and improved from the following embodiments without departing from its spirit. In addition, in the above drawings, the dimensions of each component may be exaggerated or reduced, or hatching may be omitted in order to facilitate understanding.

[0019] <Conductive Die Attach Film> First, the configuration of the conductive die attach film 10 according to the embodiment of the present invention will be described based on Figures 1 and 5. Figure 1 is an explanatory diagram showing a semiconductor chip mounting method using the conductive die attach film according to this embodiment, and Figure 5 is a cross-sectional SEM photograph of the conductive die attach film according to this embodiment.

[0020] The conductive die attach film 10 contains metal-coated resin particles 10a (hereinafter also referred to as "metal-coated resin particles (A)") and a thermosetting resin 10d (hereinafter also referred to as thermosetting resin (B)) as essential components. From the viewpoint of suppressing curing shrinkage of the conductive die attach film and improving electrical conductivity, the volume fraction of the metal-coated resin particles (A) is 40 vol% or more. Here, the volume fraction of the metal-coated resin particles (A) is the volume fraction of the metal-coated resin particles (A) relative to the total volume of the conductive die attach film 10. The volume fraction of the metal-coated resin particles (A) can be calculated from a cross-sectional SEM photograph. The total area of the metal-coated resin particles (A) relative to the total area of the cross-sectional SEM photograph may be taken as the volume fraction of the metal-coated resin particles (A). When producing the conductive die attach film 10, each material may be mixed such that the volume fraction of the metal-coated resin particles (A) is 40 vol% or more. If the volume fraction of the metal-coated resin particles (A) is less than 40 vol%, the curing shrinkage rate described later will exceed 0.03, and the effect of the present embodiment cannot be obtained. The volume fraction of the metal-coated resin particles (A) is preferably 50 vol% or more, and more preferably 60 vol% or more. The upper limit of the volume fraction of the metal-coated resin particles (A) is not particularly limited, and may be, for example, 60 vol% or less.

[0021] The metal-coated resin particles (A) comprise a resin core portion 10b and a metal layer portion 10c covering the resin core portion. The resin constituting the resin core portion 10b includes, for example, at least one of an acrylic resin and a crosslinked acrylic resin. Preferably, the resin core portion 10b is composed of at least one of an acrylic resin and a crosslinked acrylic resin. Thereby, the curing shrinkage rate described later can be easily set to 0.03 or less.

[0022] The metal layer portion 10c contains, for example, at least one of silver and copper. Preferably, the metal layer portion 10c is composed of at least one of silver and copper. This makes it possible to improve the electrical conductivity of the conductive die attach film 10. The method for forming the metal layer portion 10c is not particularly limited. By way of example, the metal layer portion 10c can be formed on the surface of the resin core portion 10a by means such as electroless silver plating and electroless copper plating. The thickness of the metal layer portion 10c is not particularly limited, and may be, for example, about 0.1 to 1 μm.

[0023] The average particle diameter d of the metal-coated resin particles (A) ５０Ａ may be, for example, about 0.1 to 20 μm. Here, the average particle diameter d of the particles in the present embodiment ５０ is a value determined by a diffraction particle size distribution analyzer. More specifically, using a diffraction particle size distribution analyzer, laser light is irradiated onto the particles, and the particle size distribution of the particle population is obtained from the angle of the scattered light intensity. Then, in the cumulative volume distribution curve, the distribution is integrated from the small particle diameter side, and the particle diameter at the point where 50% of the total volume is reached is taken as the average particle diameter d of the particles ５０ .

[0024] Any thermosetting resin (B) may be used as long as it is a resin having a curing shrinkage rate of 0.03 or less as described later; for example, epoxy resin, phenoxy resin, oxetane resin, vinyl resin, acrylic resin, phenol resin, cyanate resin, maleimide resin and the like can be used. Among these, epoxy resin and phenoxy resin are most suitable from the viewpoint of achieving both fluidity before curing and adhesion reliability and heat resistance after curing.

[0025] From the viewpoint of ensuring good adhesive reliability by suppressing curing shrinkage, it is particularly preferable that the thermosetting resin (B) is composed of one or more selected from the group consisting of at least one epoxy resin and phenoxy resin having a naphthalene skeleton (thermosetting resin (B1)), at least one epoxy resin and phenoxy resin having a bisphenol F skeleton (thermosetting resin (B2)), and at least one epoxy resin and phenoxy resin having a polyether skeleton (thermosetting resin (B3)). It is most preferable that the thermosetting resin (B) contains all of the thermosetting resins (B1) to (B3), but it may selectively contain one or more of them.

[0026] Typical examples of thermosetting resins (B1) include HP4032D (Chemical Formula 1) and HP4710 provided by DIC Corporation, and NC-7000, a naphthalene-containing novolac-type epoxy resin provided by Nippon Kayaku Co., Ltd. These epoxy resins possess excellent heat resistance, mechanical strength, and chemical stability due to their naphthalene skeleton. Phenoxy resins with a naphthalene skeleton are similar.

[0027] HP4032D combines excellent fluidity and strength after curing, making it suitable as an epoxy resin for sealing materials and adhesives in electronic equipment. HP4710 has excellent strength and heat resistance after curing, contributing to reliability, especially in high-temperature environments. These resins have epoxy groups, are thermosetting, and can be well coated even on the surface of substrates that are difficult to adhere to when melted, such as those with PPF plating and gold plating, thus achieving strong adhesion through heat treatment. In other words, by using thermosetting resin (B1), the curing shrinkage rate described later can be easily reduced to 0.03 or less. The volume fraction of thermosetting resin (B1) in the conductive die attach film is preferably 5 to 40 vol%, and more preferably 10 to 20 vol%.

[0028] The thermosetting resin (B2) promotes uniform dispersion between the metal-coated resin particles (A) and the thermosetting resin (B), contributing to the achievement of both conductivity and adhesion. The thermosetting resin (B2) has a structure represented by, for example, chemical formula 2. The thermosetting resin (B2) represented by chemical formula 2 is an example of an epoxy resin having a bisphenol F skeleton. Examples of thermosetting resins (B2) include YDF170 and YDF2001, which are bisphenol F type epoxy resins from Nippon Steel Material & Chemical Co., Ltd., YP70, which is a bisphenol A / bisphenol F copolymer type phenoxy resin from the same company, and EP-4901, which is a bisphenol F type epoxy resin from Adeka Co., Ltd. Of these, EP-4901, YDF170, etc. correspond to chemical formula 2. The volume fraction of the thermosetting resin (B2) in the conductive die attach film is preferably 5 to 40 vol%, and more preferably 10 to 20 vol%.

[0029] The thermosetting resin (B3) can further suppress the curing shrinkage of the conductive die attach film 10. Examples of thermosetting resins (B3) include EP-4000 (chemical formula 3) and EP-4010 from ADEKA Corporation, and Denacol EX-512, a polyglycerol epoxy resin from Nagase ChemteX Corporation. The volume fraction of the thermosetting resin (B3) in the conductive die attach film is preferably 5 to 40 vol%, and more preferably 10 to 20 vol%.

[0030] Examples of curing catalysts for these thermosetting resins (B) include imidazole-based, amine-based, phenol-based, thiol-based, organophosphorus-based, acid anhydride-based, acid generators, and dicyandiamide. Of these, imidazole-based curing catalysts are most suitable from the viewpoint of suppressing curing shrinkage. Imidazole-based curing catalysts are particularly suitable as curing catalysts for thermosetting resin (B1). Examples of such imidazole-based curing catalysts include methylimidazole, 2-phenylimidazole, 2-ethyl-4-methylimidazole, and 2-phenyl-4,5-dihydroxymethylimidazole. The volume fraction of the curing catalyst in the conductive die attach film is preferably 2% or less, and more preferably 1% or less.

[0031] The conductive die attach film 10, having the above composition, has a density of ρ before heat treatment of the conductive die attach film. Ｉｎｉｔ The density of the conductive die attach film after heat treatment at 150°C for 1 hour is ρ Ｔ In that case, 1 - ρ Ｉｎｉｔ / ρ Ｔ The curing shrinkage rate, as defined by [the formula], becomes 0.03 or less. This suppresses curing shrinkage during thermal curing, and consequently enables highly reliable bonding of semiconductor chips and substrates. In particular, semiconductor chips with backside metallization treatment and lead frames with at least one of PPF plating and gold plating are difficult to bond, but this makes it possible to bond them with high reliability. Specifically, curing shrinkage during bonding is suppressed, reducing the generation of residual stress, and allowing them to be bonded while maintaining high conductivity.

[0032] The conductive die attach film 10 may contain metal particles (C) in addition to metal-coated resin particles (A). In that case, the particle size distribution of the metal-coated resin particles (A) and metal particles (C) may be measured using a diffraction particle size distribution analyzer. ５０ The fact that these particles are different is preferable from the viewpoint of ensuring the fluidity of the conductive die attach film 10 during melting, while increasing the packing density of the filler (i.e., metal-coated resin particles (A) and metal particles (C)), allowing it to follow the fine irregularities on the surface of the adherend, and thus achieving both conductivity, thermal conductivity, and adhesion. Average particle diameter d of the metal-coated resin particles (A) ５０Ａ In contrast, the average particle diameter d of the metal particles (C) ５０Ｃ It is even more preferable that d is 1 / 2 or less, ５０Ａ × 1 / 5 ≥ d ５０Ｃ It is even more preferable that the volume fraction of metal particles (C) in the conductive die attach film is preferably 1 / 10 to 1 / 2, and more preferably 1 / 5 to 1 / 3, of the volume fraction of metal-coated resin particles (A). The metal constituting the metal particles is not particularly limited, but it is preferable that they be composed of at least one of silver and copper, for example.

[0033] Furthermore, the volume fractions of each material are adjusted so that their sum equals 100 vol%.

[0034] <Method for Manufacturing the Conductive Die Attach Film 10> The method for manufacturing the conductive die attach film 10 is not particularly limited, and any method that can produce a conductive die attach film 10 having the above-described characteristics is acceptable. As an example, a method can be used in which the materials constituting the conductive die attach film 10 are dissolved and dispersed in a suitable solvent, the slurry is applied to a suitable substrate (or film), and then dried.

[0035] <Dicing Die Attach Film> A dicing die attach film 30 may be formed by combining a conductive die attach film 10 with a UV-sensitive or non-UV-sensitive dicing tape 20. This allows the dicing and die attach processes to be carried out smoothly in a single flow, improving work efficiency in the semiconductor packaging process.

[0036] As will be explained in detail later, as shown in Figure 3, when picking up the semiconductor chip 100a from the dicing die attach film 30 after dicing, the cut conductive die attach film 10a and the back-side metallized semiconductor chip 100a can be picked up together at the same time. Subsequently, the semiconductor chip 100a can be placed on a substrate 400 (e.g., a lead frame) on which at least one of PPF plating and gold plating is applied to the surface using the conductive die attach film 10a. This allows the back-side metallized semiconductor chip 100a to be bonded to the substrate 400 such as a lead frame via the conductive die attach film 10a. In other words, the semiconductor chip 100a and the substrate 400 can be electrically connected. Through the above process, the semiconductor chip 100a can be efficiently mounted and mass-produced.

[0037] <Semiconductor Chip Mounting Method> Next, a semiconductor chip mounting method using the conductive die attach film 10 will be described based on Figures 1 to 4. Figures 2 to 3 are explanatory diagrams showing a semiconductor chip mounting method using the conductive die attach film 10, and Figure 4 is an explanatory diagram showing a semiconductor element according to this embodiment. In this method, the semiconductor chip 100a, which has undergone backside metallization treatment, and the substrate 400, which has at least one of PPF plating and gold plating applied to its surface, are electrically connected via the conductive die attach film 10. It should be noted that the mounting method described below is merely one example of a mounting method using the conductive die attach film 10 according to this embodiment, and of course, the semiconductor chip 100a may be mounted by other methods.

[0038] First, as shown in Figure 1, a dicing die attach film 30 is formed by combining a conductive die attach film 10 and a dicing tape 20. Next, a semiconductor wafer 100 that has undergone backside metallization is placed on the conductive die attach film 10. Alternatively, the dicing die attach film 30 is laminated onto the semiconductor wafer 100. Here, a backside metallization layer 110 is formed on the back surface of the semiconductor wafer 100, and a plurality of electrodes 120 are formed on the front surface.

[0039] Next, as shown in Figure 2, the semiconductor wafer 100 and the conductive die attach film 10 are diced together using the dicing blade 200. This produces multiple laminates 130, each containing an electrode 120, a semiconductor chip 100a, a backside metallized layer 110a, and a conductive die attach film 10a.

[0040] Next, as shown in Figures 3 and 4, the arm 300 picks up the laminate 130 individually (i.e., simultaneously picks up the cut conductive die attach film 10a and the back-side metallized semiconductor chip 100a together) and places them on the plating layer 410 of the substrate 400 (e.g., lead frame) (i.e., die attaches them). The plating layer 410 is composed of, for example, at least one of PPF plating and gold plating. Next, the conductive die attach film 10a is cured by heat treatment. Meanwhile, the wire 150 is connected to the electrode 120. Here, since the conductive die attach film 10a has the characteristics described above, curing shrinkage can be suppressed. Therefore, it is possible to join the back-side metallized semiconductor chip 100a and the substrate 400 (e.g., lead frame) on which the plating layer 410 is formed with high reliability. Specifically, curing shrinkage when they are joined is suppressed, the generation of residual stress is suppressed, and they can be joined while maintaining high conductivity.

[0041] Next, an example of this embodiment will be described. In this embodiment, the following tests were performed to confirm the effect of the conductive die attach film according to this embodiment.

[0042] <Example 1> <Preparation of conductive die attach film> A slurry was prepared by stirring and kneading the following materials and diluting them with an organic solvent. Then, the slurry was applied onto a silicone release PET film, and the organic solvent was dried to produce a conductive die attach film with a thickness of 30 μm. The thickness of the conductive die attach film was measured using a Mitutoyo Digimatic Thickness Gauge.

[0043] Thermosetting resin (B1): HP4032D (containing naphthalene skeleton) from DIC Corporation 29 vol% Thermosetting resin (B2): YP70 (containing bisphenol F skeleton) from Nippon Steel Chemical & Material Co., Ltd. 30 vol% Thermosetting resin (B3): EP-4010 (containing polyether skeleton) from ADEKA Corporation 0 vol% (not used) Curing catalyst: 2-phenylimidazole 1 vol% Metal-coated resin particles (A): Crosslinked acrylic resin powder with electroless silver plating (d５０ = 6 μm) 40 vol% Metal particles (C): None <Measurement of curing shrinkage rate> First, the initial density ρ before heat curing is measured using the water displacement method based on Archimedes' principle. Ｉｎｉｔ The following was measured. Specifically, for the test specimen of Example 1, the air mass and water mass were measured, and then the initial density ρ was calculated using the following formula. Ｉｎｉｔ The result was calculated.

[0044]

[0045] In the above formula, the density of the test specimen is the initial density ρ of the test specimen in Example 1. Ｉｎｉｔ Therefore, the density of a liquid is the density of water.

[0046] Next, the test specimen from Example 1 was heat-treated at 150°C for 1 hour, and then its density, i.e., the density after heat curing, ρ was determined again using the method described above. Ｔ They sought it.

[0047] Here, the curing shrinkage rate of Example 1 is given by curing shrinkage rate = (volume before curing V Ｉｎｉｔ - Volume after hardening V Ｔ ) / Volume V before hardening Ｉｎｉｔ Therefore, the curing shrinkage rate = 1 - V Ｔ / V Ｉｎｉｔ V Ｔ / V Ｉｎｉｔ is ρ Ｉｎｉｔ / ρ Ｔ Since this is equal to, the hardening shrinkage rate = 1 - ρ Ｉｎｉｔ / ρ Ｔ Therefore, the ρ measured above Ｉｎｉｔ and ρ Ｔ The curing shrinkage rate can be calculated using this method. The curing shrinkage rate in Example 1 was 0.03.

[0048] <Evaluation of Adhesion Reliability> A dicing die-attach film was prepared by bonding the conductive die-attach film of Example 1 with Furukawa Electric's dicing tape 334EP. Next, this dicing die-attach film was laminated at 70°C to a 350 μmt silicon wafer with a silver metallized (sputtered) back surface. Then, multiple silicon chip stacks were prepared by dicing the silicon wafer and die-attach film into 5 mm sq pieces. Next, one silicon chip stack was picked up and die-attached to a substrate at 120°C. The substrate used at this time was a 10 mm sq × 150 μmt copper substrate with PPF plating consisting of three layers of Ni / Pd / Au. Next, the conductive die-attach film was cured by heat treatment (curing treatment) of the obtained stack at 150°C × 1h. A test element was then assembled.

[0049] For the test elements assembled using the method described above, the adhesion strength of the silicon chip to the copper substrate via the conductive die attach film was measured using a die shear tester under conditions of room temperature and a shear speed of 1 mm / sec, and this was defined as the initial adhesion strength.

[0050] Next, the test elements were subjected to moisture absorption under the same conditions as the MSL1 test method specified in IPC / JEDEC J-STD-020 (85°C, 85% RH x 168h), and then reflow treatment was performed three times. After that, the adhesive strength of the test elements was measured using the same method as initially, and this was defined as the adhesive strength after MSL1.

[0051] Next, the test elements treated with MSL1 were subjected to a thermal shock tester, repeatedly holding at -65°C for 15 min and +150°C for 15 min for 1000 cycles. After that, the adhesive strength of the test elements was measured using the same method as initially, and this was recorded as the adhesive strength after 1000 cycles of TCT.

[0052] In Example 1, the initial adhesive strength was 12 MPa, the adhesive strength after MSL1 was 9 MPa, and the adhesive strength after TCT × 1000 cy was 8 MPa.

[0053] <Evaluation of Electrical Connection Reliability> A 100 μm thick copper foil was processed into a 5 mm sq chip, and then flash-plated with gold on both sides to create a simulated resistor chip. Next, a resistor chip laminate was fabricated by laminating the conductive die-attach film of Example 1 onto the resistor chip. Next, the resistor chip laminate was die-attached to a 10 mm sq × 150 μm thick copper lead frame that had been flash-plated with gold at 120°C. Then, the conductive die-attach film was cured by heat-treating (hardening) the resulting laminate at 150°C for 1 hour. Next, a test element was assembled by attaching 300 μm diameter × 10 mm long aluminum wires to the center of the resistor chip surface and to the corners of the ends of the copper lead frame using an ultrasonic wire bonder.

[0054] For the assembled test element, the electrical resistance between the wire connected to the resistor chip and the wire connected to the copper lead frame was measured using the four-terminal method and determined as the initial connection electrical resistance.

[0055] Next, the test element was subjected to moisture absorption under the same conditions as the MSL1 test method specified in IPC / JEDEC J-STD-020 (85°C, 85% RH × 168h), and then reflow treatment was performed three times. After that, the electrical resistance of the test element was measured using the same method as initially, and this was used as the connected electrical resistance after MSL1.

[0056] Next, the test element that had undergone the MSL1 treatment was subjected to a thermal shock tester, repeatedly holding it at -65°C for 15 min and then at +150°C for 15 min for 1000 cycles. After that, the electrical resistance of the test element was measured using the same method as initially, and this was used as the connected electrical resistance after 1000 cycles of TCT.

[0057] In Example 1, the initial connection electrical resistance was 85 mΩ, the connection electrical resistance after MSL1 was 96 mΩ, and the connection electrical resistance after TCT × 1000 cy was 107 mΩ. The composition of the conductive die attach film and the evaluation results are summarized in Table 1.

[0058] <Example 2> The same procedure as in Example 1 was performed, except that the composition of the conductive die attach film was changed as follows.

[0059] Thermosetting resin (B1): HP4032D 14 vol% from DIC Corporation Thermosetting resin (B2): YP70 30 vol% from Nippon Steel Chemical & Material Co., Ltd. Thermosetting resin (B3): EP-4010 (containing polyether skeleton) 10 vol% from ADEKA Corporation Curing catalyst: 2-phenylimidazole 1 vol% Metal-coated resin particles (A): Crosslinked acrylic resin powder with electroless silver plating (d ５０ (=6 μm) 45 vol% Metal particles (C): None The evaluation results were as follows.

[0060] Curing shrinkage rate: 0.01 Adhesion reliability (adhesion strength): Initial 16 MPa, after MSL1 13 MPa, after TCT × 1000 cy 12 MPa Electrical connection reliability (connection electrical resistance): Initial 82 mΩ, after MSL1 91 mΩ, after TCT × 1000 cy 97 mΩ The composition of the conductive die attach film and the evaluation results are summarized in Table 1.

[0061] <Example 3> The same procedure as in Example 1 was performed, except that the composition of the conductive die attach film was changed as follows.

[0062] Thermosetting resin (B1): HP4032D 14 vol% from DIC Corporation Thermosetting resin (B2): YP70 25 vol% from Nippon Steel Chemical & Material Co., Ltd. Thermosetting resin (B3): EP-4010 (containing polyether skeleton) 10 vol% from ADEKA Corporation Curing catalyst: 2-phenylimidazole 1 vol% Metal-coated resin particles (A): Crosslinked acrylic resin powder with electroless silver plating (d ５０ = 6 μm) 40 vol% Metal particles (C): Silver atomized powder (d ５０ (=3 μm) 10 vol% The evaluation results were as follows.

[0063] Curing shrinkage rate: Less than 0.01 Adhesion reliability (adhesion strength): Initial 18 MPa, after MSL1 16 MPa, after TCT × 1000 cy 16 MPa Electrical connection reliability (connection electrical resistance): Initial 63 mΩ, after MSL1 67 mΩ, after TCT × 1000 cy 69 mΩ The composition of the conductive die attach film and the evaluation results are summarized in Table 1.

[0064] <Example 4> The same procedure as in Example 1 was performed, except that the composition of the conductive die attach film was changed as follows.

[0065] Thermosetting resin (B1): HP4032D 14 vol% from DIC Corporation Thermosetting resin (B2): YP70 25 vol% from Nippon Steel Chemical & Material Co., Ltd. Thermosetting resin (B3): EP-4010 (containing polyether skeleton) 10 vol% from ADEKA Corporation Curing catalyst: 2-phenylimidazole 1 vol% Metal-coated resin particles (A): Crosslinked acrylic resin powder with electroless copper plating (d ５０ (=15 μm) 50 vol% Metal particles (C): None The evaluation results were as follows.

[0066] Curing shrinkage rate: 0.01 Adhesion reliability (adhesion strength): Initial 16 MPa, after MSL1 12 MPa, after TCT × 1000 cy 10 MPa Electrical connection reliability (connection electrical resistance): Initial 570 mΩ, after MSL1 610 mΩ, after TCT × 1000 cy 600 mΩ The composition of the conductive die attach film and the evaluation results are summarized in Table 1.

[0067] <Example 5> The same procedure as in Example 1 was performed, except that the composition of the conductive die attach film was changed as follows.

[0068] Thermosetting resin (B1): HP4032D 10 vol% from DIC Corporation Thermosetting resin (B2): YP70 23 vol% from Nippon Steel Chemical & Material Co., Ltd. Thermosetting resin (B3): EP-4010 (containing polyether skeleton) 6 vol% from ADEKA Corporation Curing catalyst: 2-phenylimidazole 1 vol% Metal-coated resin particles (A): Crosslinked acrylic resin powder with electroless copper plating (d ５０ = 15 μm) 50 vol% Metal particles (C): Copper atomized powder (d ５０ (=3 μm) 10 vol% The evaluation results were as follows.

[0069] Curing shrinkage rate: less than 0.01 Adhesion reliability (adhesion strength): 18 MPa initially, 15 MPa after MSL1, 14 MPa after TCT × 1000 cy Electrical connection reliability (connection electrical resistance): 180 mΩ initially, 210 mΩ after MSL1, 230 mΩ after TCT The composition of the conductive die attach film and the evaluation results are summarized in Table 1.

[0070] <Comparative Example 1> The same procedure as in Example 1 was performed, except that the composition of the conductive die attach film was changed as follows.

[0071] Thermosetting resin 1: Bisphenol A type epoxy (RE310 from Nippon Kayaku Co., Ltd.) 40 vol% Thermosetting resin 2: Bisphenol A type phenoxy (YP50 from Nippon Steel Chemical & Material Co., Ltd.) 40 vol% Curing catalyst: Dicyandiamide 10 vol% Metal-coated resin particles (A): Cross-linked acrylic resin powder with electroless silver plating (d ５０ (=6 μm) 10 vol% Metal particles (C): None The evaluation results were as follows.

[0072] Curing shrinkage rate: 0.07 Adhesion reliability (adhesion strength): Initial 23 MPa, after MSL1 4 MPa, after TCT × 1000 cy 3 MPa Electrical connection reliability (connection electrical resistance): Initial >100 Ω, after MSL1 >100 Ω, after TCT × 1000 cy >100 Ω The composition of the conductive die attach film and the evaluation results are summarized in Table 2.

[0073] <Comparative Example 2> The same procedure as in Example 1 was performed, except that the composition of the conductive die attach film was changed as follows.

[0074] Thermosetting resin 1: Bisphenol A type epoxy (RE310 from Nippon Kayaku Co., Ltd.) 30 vol% Thermosetting resin 2: Bisphenol A type phenoxy (YP50 from Nippon Steel Chemical & Material Co., Ltd.) 30 vol% Curing catalyst: Dicyandiamide 7.5 vol% Metal-coated resin particles (A): Cross-linked acrylic resin powder with electroless silver plating (d ５０ (=6 μm) 32.5 vol% Metal particles (C): None The evaluation results were as follows.

[0075] Curing shrinkage rate: 0.05 Adhesion reliability (adhesion strength): Initial 19 MPa, after MSL1 6 MPa, after TCT × 1000 cy 3 MPa Electrical connection reliability (connection electrical resistance): Initial 100 mΩ, after MSL1 1.7 Ω, after TCT × 1000 cy 2.2 Ω The composition of the conductive die attach film and the evaluation results are summarized in Table 2.

[0076] <Comparative Example 3> The same procedure as in Example 1 was performed, except that the composition of the conductive die attach film was changed as follows.

[0077] Thermosetting resin 1: Bisphenol A type epoxy (RE310 from Nippon Kayaku Co., Ltd.) 20 vol% Thermosetting resin 2: Bisphenol A type phenoxy (YP50 from Nippon Steel Chemical & Material Co., Ltd.) 20 vol% Curing catalyst: Dicyandiamide 5 vol% Metal-coated resin particles (A): None Metal particles (C): Silver atomized powder (d ５０ =3um) 55 vol% The evaluation results were as follows.

[0078] Curing shrinkage rate: 0.09 Adhesion reliability (adhesion strength): Initial 9 MPa, after MSL1 2 MPa, after TCT × 1000 cy 1 MPa Electrical connection reliability (connection electrical resistance): Initial 55 mΩ, after MSL1 1.3 Ω, after TCT × 1000 cy 2.4 Ω

[0079]

[0080]

[0081] <Discussion> In Examples 1 to 5, which satisfy the requirements of this embodiment, good results were obtained in terms of adhesive reliability and electrical connection reliability. Specifically, the adhesive strength was able to maintain high values ​​at the initial stage, after MSL1, and after TCT × 1000cy, and the connection electrical resistance was able to maintain low values ​​at the initial stage, after MSL1, and after TCT × 1000cy. This is presumed to be due to the small residual stress caused by curing shrinkage. Therefore, curing shrinkage was suppressed during thermal curing, and consequently, the semiconductor chip and the substrate could be joined with high reliability. In particular, although the adherends in Examples 1 to 5 were all difficult to adhere, curing shrinkage during joining was suppressed, the generation of residual stress was suppressed, and they could be joined while maintaining high conductivity.

[0082] On the other hand, Comparative Examples 1 to 3 did not satisfy the requirements of this embodiment. Specifically, the volume fraction of the metal-coated resin particles (A) was less than 40 vol%, and the curing shrinkage rate exceeded 0.03. As a result, the evaluation of adhesive reliability and electrical connection reliability was low. Specifically, although the adhesive strength showed a high value initially, it became significantly low after MSL1 and after TCT × 1000 cy. This is presumed to be due to increased residual stress due to curing shrinkage during thermal curing. Regarding electrical connection reliability, in Comparative Example 1, the connection electrical resistance was high from the beginning, and in Comparative Examples 2 and 3, although the initial connection electrical resistance was low, the connection electrical resistance increased after MSL1 and after TCT × 1000 cy. This is also presumed to be due to increased residual stress due to curing shrinkage during thermal curing.

[0083] Although the present invention has been described above with reference to the above embodiments, the present invention is not limited thereto. Those skilled in the art can appropriately modify the conductive die attach film, dicing die attach film, and semiconductor chip mounting method of the present invention in accordance with conventionally known knowledge. Such modifications, insofar as they still possess the configuration of the present invention, are of course included within the scope of the present invention.

[0084] 10 Conductive die attach film, 20 Dicing tape, 30 Dicing die attach film, 100 Semiconductor wafer, 100a Semiconductor chip, 110 Backside metallized layer, 120 Electrode, 130 Laminate

Claims

1. A conductive die attach film comprising metal-coated resin particles and a thermosetting resin as essential components, wherein the volume fraction of the metal-coated resin particles is 40 vol% or more, and the density of the conductive die attach film before heat treatment is ρ Ｉｎｉｔ The density of the conductive die attach film after heat treatment at 150°C for 1 hour is ρ Ｔ In that case, 1 - ρ Ｉｎｉｔ / ρ Ｔ A conductive die attach film having a curing shrinkage rate of 0.03 or less, as defined by [a specific formula / method].

2. The conductive die attach film according to claim 1, wherein the thermosetting resin comprises at least one epoxy resin and a phenoxy resin having a naphthalene skeleton, and an imidazole-based curing catalyst.

3. The conductive die attach film according to claim 1, wherein the thermosetting resin comprises at least one of an epoxy resin having a bisphenol F skeleton and a phenoxy resin.

4. The conductive die attach film according to claim 1, wherein the thermosetting resin comprises at least one of an epoxy resin having a polyether skeleton and a phenoxy resin.

5. The conductive die attach film according to claim 1, wherein the resin core portion constituting the metal-coated resin particles comprises at least one of acrylic resin and crosslinked acrylic resin.

6. The conductive die attach film according to claim 1, wherein the metal layer portion constituting the metal-coated resin particles includes at least one of silver and copper.

7. The conductive die attach film contains metal particles in addition to the metal-coated resin particles, and the average particle size d of the metal-coated resin particles and the metal particles as determined by a diffraction particle size distribution meter. ５０ A conductive die attach film according to claim 1, wherein each of these is different.

8. A dicing die attach film comprising a conductive die attach film and a dicing tape as described in any one of claims 1 to 7.

9. A method for mounting a semiconductor chip, comprising electrically connecting a semiconductor chip that has undergone backside metallization treatment and a substrate on which at least one of PPF plating and gold plating is applied to the surface, via a conductive die attach film according to any one of claims 1 to 7.

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