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

Abstract

Provided are a conductive die attach film, a dicing die attach film, and a method for mounting a semiconductor chip, which can suppress curing shrinkage during thermosetting and, consequently, join a semiconductor chip and a substrate such as a lead frame with high reliability. 【Solution means】A conductive die attach film containing 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 , and when the density of the conductive die attach film after heat treatment at 150 °C for 1 h is ρ T , the curing shrinkage rate defined by 1 - ρ Init / ρ T is 0.03 or less. A conductive die attach film.

Description

Technical Field

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

Background Art

[0002] For example, as disclosed in Patent Documents 1 and 2, as an adhesive for bonding a semiconductor chip to a substrate such as a lead frame, a conductive adhesive in which an epoxy resin and conductive metal particles such as silver particles are combined is often used. In recent years, a conductive die attach film formed by molding a component similar to the conductive adhesive into a film shape has also come to be used.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, conventional conductive adhesives and conductive die attach films had the property of curing and shrinking during thermosetting. Due to the influence of the residual stress caused by this curing shrinkage, 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.)), the bonding interface between the semiconductor chip and the conductive adhesive or conductive die attach film might peel off. In particular, there was poor adhesiveness between a semiconductor chip with a backside metallization process and a lead frame with at least one of PPF (Pre Plated Leadframe, Pre Plated Frame) plating or gold plating. When attempting to bond these with a conductive adhesive or conductive die attach film, the bonding interface easily peeled off, resulting in a problem of low reliability.

[0005] The present invention was made to solve the above problems, and its object is to suppress curing shrinkage during thermosetting, and thus to provide a conductive die attach film, a dicing die attach film, and a method for mounting a semiconductor chip that can bond a semiconductor chip and a substrate such as a lead frame with high reliability.

Means for Solving the Problems

[0006] As a result of intensive studies by the present inventor, a conductive die attach film containing 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 and the density of the conductive die attach film after heat treatment at 150 °C × 1 h is ρ T When, 1 - ρ Init / ρ T It was found that the above problems are solved by a conductive die attach film having a curing shrinkage rate defined by 0.03 or less. According to one aspect of the present invention, the following inventions are provided.

[0007] (1) A conductive die attach film containing 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, Let the density of the conductive die attach film before heat treatment be ρ Init and the density of the conductive die attach film after heat treatment at 150 °C for 1 h be ρ T When, Init / ρ T the conductive die attach film having a curing shrinkage rate defined by is 0.03 or less.

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

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

[0010] (4) The conductive die attach film according to any one of (1) to (3), wherein the thermosetting resin contains 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 the 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 the 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, The average particle diameter d of the metal-coated resin particles and the metal particles measured by a diffraction particle size distribution meter 50 is different for each, and the conductive die attach film according to any one of (1) to (6).

[0014] (8) A dicing die attach film obtained by combining the conductive die attach film according to any one of (1) to (7) with a dicing tape.

[0015] (9) A method for mounting a semiconductor chip, which electrically connects a semiconductor chip subjected to backside metallization treatment via the conductive die attach film according to any one of (1) to (7) and a substrate having at least one of PPF plating and gold plating applied to its surface. [Effect of the Invention]

[0016] According to one aspect of the present invention, it is possible to suppress curing shrinkage during thermosetting, and thus join a semiconductor chip and a substrate with high reliability. [Brief Description of the Drawings]

[0017]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Best Mode for Carrying Out the Invention

[0018] Hereinafter, embodiments for implementing a conductive die attach film, a dicing die attach film, and a method for mounting a semiconductor chip according to the present invention will be illustrated together with the drawings. The embodiments illustrated below are for facilitating the understanding of the present invention and are not for limiting the interpretation of the present invention. The present invention can be changed and improved from the following embodiments without departing from its gist. Also, in the above drawings, the dimensions of each member may be exaggerated or reduced for easy understanding, or hatching may be omitted.

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

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

[0021] The resin particles (A) coated with a metal include a resin core portion 10b and a metal layer portion 10c that covers the resin core portion. The resin constituting the resin core portion 10b contains, 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 made 0.03 or less.

[0022] The metal layer portion 10c contains at least one of, for example, silver and copper. Preferably, the metal layer portion 10c is composed of at least one of silver and copper. Thereby, the electrical conductivity of the conductive die attach film 10 can be improved. The method for forming the metal layer portion 10c is not particularly limited. As an 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, but 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 obtained by a diffraction particle size distribution meter. More specifically, using a diffraction particle size distribution meter, 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 size side, and the particle size at the point where 50% of the total volume is reached is taken as the average particle diameter d of the particles. 50 is set as such.

[0024] The thermosetting resin (B) may be any resin as long as the curing shrinkage rate described below is 0.03 or less. For example, epoxy resins, phenoxy resins, oxetane resins, vinyl resins, acrylic resins, phenolic resins, cyanate resins, and maleimide resins can be used. Among these, epoxy resins and phenoxy resins are most suitable from the viewpoint of achieving both the fluidity before curing and the adhesion reliability and heat resistance after curing.

[0025] From the viewpoint of ensuring good adhesion reliability by suppressing hardening shrinkage, in particular, the thermosetting resin (B) is preferably composed of at least one resin selected from the group consisting of an epoxy resin having a naphthalene skeleton and a phenoxy resin (thermosetting resin (B1)), at least one resin selected from the group consisting of an epoxy resin having a bisphenol F skeleton and a phenoxy resin (thermosetting resin (B2)), and at least one resin selected from the group consisting of an epoxy resin having a polyether skeleton and a phenoxy resin (thermosetting resin (B3)). Most preferably, the thermosetting resin (B) contains all of the thermosetting resins (B1) to (B3), but it may selectively contain any one or more of them.

[0026] Typical examples of the thermosetting resin (B1) include HP4032D (chemical formula 1) and HP4710 provided by DIC Corporation, and NC-7000, a naphthalene-containing novolak-type epoxy resin provided by Nippon Kayaku Co., Ltd. These epoxy resins have excellent heat resistance, mechanical strength, and chemical stability due to having a naphthalene skeleton. The same applies to phenoxy resins having a naphthalene skeleton.

[0027]

Chemical formula

[0028] The thermosetting resin (B2) promotes the uniform dispersion of the metal-coated resin particles (A) and the thermosetting resin (B), and contributes to achieving both conductivity and adhesiveness. The thermosetting resin (B2) has, for example, a structure represented by 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 the thermosetting resin (B2) include YDF170 and YDF2001, which are bisphenol F type epoxy resins of Nippon Steel & Sumikin Materials Co., Ltd., YP70, which is a bisphenol A / bisphenol F copolymer type phenoxy resin of the same company, and EP-4901, which is a bisphenol F type epoxy resin of Adeka Corporation. Among these, those corresponding to Chemical Formula 2 are, for example, EP-4901, YDF170, etc. The volume fraction of the thermosetting resin (B2) in the conductive die attach film is preferably 5 to 40 vol%, more preferably 10 to 20 vol%.

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

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

[0031] By having the above composition, the conductive die attach film 10 has a density ρ before heat treatment of the conductive die attach film Init and a density ρ after heat treatment at 150 °C for 1 h of the conductive die attach film T When used, the curing shrinkage rate defined by 1 - ρ Init / ρ T is 0.03 or less. Thereby, curing shrinkage during thermosetting can be suppressed, and as a result, it becomes possible to join the semiconductor chip and the substrate with high reliability. In particular, although there is poor adhesiveness between a semiconductor chip having a backside metallization treatment and a lead frame subjected to at least one of PPF plating and gold plating, it becomes possible to join these with high reliability. Specifically, curing shrinkage when joining these can be suppressed to suppress the generation of residual stress, and these can be joined while maintaining high conductivity.

[0032] The conductive die attach film 10 may contain metal particles (C) separately from the metal-coated resin particles (A). In that case, the d of the metal-coated resin particles (A) and the metal particles (C) by a diffraction particle size distribution meter 50The fact that they are different from each other is preferable from the viewpoint of achieving both conductivity, heat conductivity, and adhesiveness while increasing the filling density of the fillers (i.e., the metal-coated resin particles (A) and the metal particles (C)) and ensuring the fluidity of the conductive die attach film 10 during melting so that it follows the fine unevenness on the surface of the adherend. The average particle diameter d of the metal-coated resin particles (A) 50A relative to the average particle diameter d of the metal particles (C) 50C is more preferably 1 / 2 or less, and d 50A ×1 / 5 ≥ d 50C is even more preferable. The volume fraction of the 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 the metal-coated resin particles (A). The metal constituting the metal particles is not particularly limited, but is preferably composed of at least one of silver and copper, for example.

[0033] Note that the volume fractions of the respective materials are adjusted so that their total is 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 may be used as long as it can manufacture the conductive die attach film 10 having the above characteristics. As an example, a method may be mentioned in which a slurry obtained by dissolving and dispersing the materials constituting the conductive die attach film 10 in an appropriate solvent is applied onto an appropriate substrate (or film) and dried.

[0035] <Dicing die attach film> The conductive die attach film 10 and a UV-sensitive or non-UV-sensitive dicing tape 20 may be combined to form a dicing die attach film 30. Thereby, the dicing and die attach processes can be smoothly performed in a series of flows, and the working efficiency in the semiconductor mounting process is improved.

[0036] As will be described in detail later, as shown in FIG. 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 semiconductor chip 100a with the back surface metallized can be picked up simultaneously. Thereafter, the semiconductor chip 100a can be placed on a substrate 400 (for example, a lead frame) on which at least one of PPF plating and gold plating is applied to the surface by the conductive die attach film 10a. Thereby, the semiconductor chip 100a with the back surface metallized can be adhered to the substrate 400 such as a lead frame via the conductive die attach film 10a. That is, the semiconductor chip 100a and the substrate 400 can be electrically connected. By the above steps, the semiconductor chip 100a can be efficiently mounted and mass-produced.

[0037] <Semiconductor Chip Mounting Method> Next, based on FIGS. 1 to 4, a semiconductor chip mounting method using the conductive die attach film 10 will be described. FIGS. 2 to 3 are explanatory views showing a semiconductor chip mounting method using the conductive die attach film 10, and FIG. 4 is an explanatory view showing a semiconductor element according to the present embodiment. In this method, the semiconductor chip 100a with the back surface metallized and the substrate 400 on which at least one of PPF plating and gold plating is applied to the surface are electrically connected via the conductive die attach film 10. Note that the mounting method described below is merely an example of a mounting method using the conductive die attach film 10 according to the present embodiment, and it goes without saying that the semiconductor chip 100a may be mounted by other methods.

[0038] First, as shown in FIG. 1, the conductive die attach film 10 and the dicing tape 20 are combined to form a dicing die attach film 30. Next, the semiconductor wafer 100 with the back surface metallized is placed on the conductive die attach film 10. Alternatively, the dicing die attach film 30 is laminated on the semiconductor wafer 100. Here, a back surface metallization layer 110 is formed on the back surface of the semiconductor wafer 100, and a plurality of electrodes 120 are formed on the surface.

[0039] Next, as shown in FIG. 2, the semiconductor wafer 100 and the conductive die attach film 10 are diced together using the dicing blade 200. As a result, a plurality of laminates 130 in which the electrodes 120, the semiconductor chips 100a, the back surface metallization layers 110a, and the conductive die attach films 10a are laminated are produced.

[0040] Next, as shown in FIGS. 3 and 4, the arm 300 individually picks up the laminate 130 (that is, simultaneously picks up the cut conductive die attach film 10a and the back surface metallized semiconductor chip 100a) and places it (that is, die-attaches it) on the plating layer 410 of the substrate 400 (for example, a lead frame). 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. On the other hand, the wire 150 is connected to the electrode 120. Here, since the conductive die attach film 10a has the above-described characteristics, shrinkage during curing can be suppressed. Therefore, it is possible to join the back surface metallized semiconductor chip 100a and the substrate 400 (for example, a lead frame) on which the plating layer 410 is formed with high reliability. Specifically, shrinkage during curing when these are joined is suppressed to suppress the generation of residual stress, and these can be joined while maintaining high conductivity.

Example

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

[0042] <Example 1> <Production of Conductive Die Attach Film> The following materials were stirred and kneaded, and then diluted with an organic solvent to prepare a slurry. Subsequently, the slurry was applied onto a silicone release PET film, and then the organic solvent was dried to prepare a conductive die attach film with a thickness of 30 μm. The thickness of the conductive die attach film was measured using a Mitutoyo digital vernier 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 electroless silver-plated (d 50 = 6 μm), 40 vol% Metal particles (C): None <Measurement of Curing Shrinkage Rate> First, the initial density ρ Init before thermosetting was measured by the water displacement method using the principle of Archimedes. Specifically, for the test piece of Example 1, the mass in air and the mass in water were measured, and then the initial density ρ Init was calculated using the following formula.

[0044]

Equation

[0045] In the above formula, the density of the test piece is the initial density ρ Init of the test piece of Example 1, and the density of the liquid is the density of water.

[0046] Next, after heat-treating the test piece of Example 1 at 150 °C for 1 hour, the density again, that is, the density ρ T after thermosetting, was determined by the above method.

[0047] Here, the curing shrinkage rate of Example 1 is Curing shrinkage rate = (Volume V before curing Init - Volume V after curing T ) / Volume V before curing Init If we set it as such, Curing shrinkage rate = 1 - V T / V Init V T / V Init is equal to ρ Init / ρ T So, Curing shrinkage rate = 1 - ρ Init / ρ T becomes. Therefore, using ρ Init and ρ T measured above, the curing shrinkage rate can be calculated. The curing shrinkage rate of Example 1 was 0.03.

[0048] <Evaluation of Adhesion Reliability> The conductive die attach film of Example 1 was laminated with Furukawa Electric Co., Ltd. dicing tape 334EP to produce a dicing die attach film. Then, this dicing die attach film was laminated on a 350 μm t silicon wafer metallized (sputtered) with silver on the back surface at 70°C. Then, the silicon wafer and the die attach film were diced into individual pieces at 5 mm sq to produce a plurality of silicon chip laminates. Then, one silicon chip laminate was picked up and die attached to a substrate at 120°C. The substrate used at this time was a copper substrate 10 mm sq × 150 μm t with PPF plating consisting of three layers of Ni / Pd / Au. Then, the obtained laminate was heat treated (curing treatment) at 150°C × 1 h to cure the conductive die attach film. Thereby, a test element was assembled.

[0049] Regarding the test element assembled by the above method, using a die shear tester, the strength with which the silicon chip was adhered to the copper substrate through the conductive die attach film was measured under the conditions of room temperature and a shear rate of 1 mm / sec, and this was taken as the initial adhesion force.

[0050] Subsequently, after the test elements were moisture-absorbed under the same moisture-absorption conditions (85°C, 85% RH × 168 h) as the test method for MSL1 defined in IPC / JEDEC J-STD-020, reflow processing was performed three times. Thereafter, the adhesive strength of the test elements was measured in the same manner as in the initial stage to obtain the adhesive strength after MSL1.

[0051] Subsequently, the test elements subjected to the MSL1 treatment were further subjected to 1000 cycles of a process of repeating holding at -65°C × 15 min and holding at +150°C × 15 min using a thermal shock tester. Thereafter, the adhesive strength of the test elements was measured in the same manner as in the initial stage to obtain the adhesive strength after TCT × 1000 cy.

[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> After processing a 100 μm t copper foil into a 5 mm sq chip shape, flash gold plating was applied to both sides thereof to fabricate a simulated resistor chip. Subsequently, a resistor chip laminate was fabricated by bonding the conductive die attach film of Example 1 to the resistor chip. Subsequently, the resistor chip laminate was die-attached to a copper lead frame of 10 mm sq × 150 μm t with flash gold plating at 120°C. Subsequently, the obtained laminate was heat-treated (cured) at 150°C × 1 h to cure the conductive die attach film. Next, a test element was assembled by attaching aluminum wires of 300 μm Φ × 10 mm L to the center of the surface of the resistor chip and to the corner of the end 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 by the four-terminal method to obtain the initial connection electrical resistance.

[0055] Next, after the test elements were moisture-absorbed under the same moisture-absorption conditions (85°C, 85% RH × 168 h) as defined in IPC / JEDEC J-STD-020 for MSL1, reflow processing was performed three times. Thereafter, the electrical resistance of the test elements was measured in the same manner as in the initial stage to obtain the connection electrical resistance after MSL1.

[0056] Next, after performing 1000 cycles of the process of repeating holding at -65°C for 15 minutes and holding at +150°C for 15 minutes on the test elements subjected to MSL1 treatment using a thermal shock tester, the electrical resistance of the test elements was measured in the same manner as in the initial stage to obtain the connection electrical resistance after TCT × 1000 cy.

[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 processing as in Example 1 was performed except that the composition of the conductive die attach film was changed as follows.

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

[0060] Shrinkage rate upon curing: 0.01 Adhesion reliability (adhesive 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 and evaluation results of the conductive die attach film are summarized in Table 1.

[0061] <Example 3> The same processing 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 from DIC Corporation, 14 vol% Thermosetting resin (B2): YP70 from Nippon Steel Chemical & Material Co., Ltd., 25 vol% Thermosetting resin (B3): EP-4010 (containing polyether backbone) from Adeka Corporation, 10 vol% Curing catalyst: 2-Phenylimidazole, 1 vol% Metal-coated resin particles (A): Crosslinked acrylic resin powder electroless silver-plated (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] Shrinkage rate on curing: Less than 0.01 Adhesion reliability (adhesive 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 and evaluation results of the conductive die attach film are summarized in Table 1.

[0064] <Example 4> The same processing 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 from DIC Corporation, 14 vol% Thermosetting resin (B2): 25 vol% of YP70 from Nippon Steel Chemical & Material Co., Ltd. Thermosetting resin (B3): 10 vol% of EP-4010 (containing polyether backbone) from Adeka Corporation Curing catalyst: 1 vol% of 2-phenylimidazole Metal-coated resin particles (A): Electroless copper plating (d 50 = 15 μm) on crosslinked acrylic resin powder, 50 vol% Metal particles (C): None The evaluation results were as follows.

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

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

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

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

[0070] <Comparative Example 1> The same process 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 of Nippon Kayaku Co., Ltd.) 40 vol% Thermosetting resin 2: Bisphenol A type phenoxy (YP50 of Nippon Steel Chemical & Material Co., Ltd.) 40 vol% Curing catalyst: Dicyandiamide 10 vol% Metal-coated resin particles (A): Those obtained by electroless silver plating on crosslinked acrylic resin powder (d 50 = 6 μm) 10 vol% Metal particles (C): None The evaluation results were as follows.

[0072] Shrinkage rate of curing: 0.07 Adhesion reliability (adhesive 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 and evaluation results of the conductive die attach film are summarized in Table 2.

[0073] <Comparative Example 2> The same process 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 of Nippon Kayaku Co., Ltd.) 30 vol% Thermosetting resin 2: Bisphenol A type phenoxy (YP50 of Nippon Steel Chemical & Material Co., Ltd.) 30 vol% Curing catalyst: Dicyandiamide 7.5 vol% Metal-coated resin particles (A): Crosslinked acrylic resin powder electroless silver-plated (d 50 = 6 μm) 32.5 vol% Metal particles (C): None The evaluation results were as follows.

[0075] Shrinkage rate during curing: 0.05 Adhesion reliability (adhesive 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 and evaluation results of the conductive die attach film are summarized in Table 2.

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

[0077] Thermosetting resin 1: Bisphenol A type epoxy (RE310 of Nippon Kayaku Co., Ltd.) 20 vol% Thermosetting resin 2: Bisphenol A type phenoxy (YP50 of 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 = 3 μm) 55 vol% The evaluation results were as follows.

[0078] Shrinkage rate during curing: 0.09 Adhesion reliability (adhesive 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]

Table 1

[0080]

Table 2

[0081] <Investigation> In Examples 1 to 5 that satisfy the requirements of this embodiment, good results were obtained in terms of adhesion reliability and electrical connection reliability. Specifically, the adhesive strength could maintain a high value at any of the initial stage, after MSL1, and after TCT×1000 cy, and the connection electrical resistance could maintain a low value at any of the initial stage, after MSL1, and after TCT×1000 cy. This is presumably because the residual stress due to curing shrinkage is small. Therefore, curing shrinkage was suppressed during thermosetting, and as a result, the semiconductor chip and the substrate could be joined with high reliability. In particular, although all the adherends in Examples 1 to 5 were difficult-to-adhere materials, it was possible to suppress the curing shrinkage when joining them, suppress the generation of residual stress, and join them 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. For this reason, the evaluation of adhesion reliability and electrical connection reliability became low. Specifically, although the adhesive strength showed a high value initially, it became significantly low after MSL1 and after TCT×1000 cy. This is presumably because the residual stress due to curing shrinkage during thermosetting became large. Regarding the electrical connection reliability, in Comparative Example 1, the connection electrical resistance became high from the beginning, and in Comparative Examples 2 and 3, although the initial connection electrical resistance was low, the connection electrical resistance after MSL1 and after TCT×1000 cy became high. This is also presumably because the residual stress due to curing shrinkage during thermosetting became large.

[0083] As described above, the present invention has been explained by taking the above embodiments as examples, but 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 according to the conventionally known knowledge. As long as the configuration of the present invention is still provided even by such modifications, of course, it is included in the scope of the present invention.

Explanation of Signs

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

Claims

1. A conductive die attach film containing 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, Let ρ be the density of the conductive die attach film before heat treatment. Ｉｎｉｔ When the density of the conductive die attach film after heat treatment at 150 °C for 1 h is ρ Ｔ and 1 - ρ Ｉｎｉｔ / ρ Ｔ is defined as the curing shrinkage rate, the conductive die attach film has a curing shrinkage rate of 0.03 or less.

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

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

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

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

7. The conductive die attach film contains metal particles separately from the metal-coated resin particles, The average particle diameter d measured by a diffraction particle size distribution analyzer for the metal-coated resin particles and the metal particles ５０ is different for each, and the conductive die attach film according to claim 1.

8. A dicing die attach film combining the conductive die attach film according to any one of claims 1 to 7 and a dicing tape.

9. A method for mounting a semiconductor chip, which electrically connects a semiconductor chip subjected to backside metallization treatment and a substrate having at least one of PPF plating and gold plating applied to the surface through the conductive die attach film according to any one of claims 1 to 7.

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