Conductive Adhesive Composition and Method for Manufacturing an Imaging Module

Abstract

Disclosed is a conductive adhesive composition used for producing an imaging module 101 comprising a wiring board 10 and a semiconductor component 20 that contains a solid-state imaging element 21. The solid-state imaging element 21 is a wafer-level chip-size package. The conductive adhesive composition contains (A) conductive particles that include a metal, (B) a thermosetting resin, and (C) a flux activator. The flux activator contains a compound having a hydroxyl group and a carboxyl group. The amount of the flux activator is 1.0-3.9 mass% relative to the mass of the conductive particles. A connection portion 8 is formed by means of the conductive adhesive composition.

Description

Technical Field

[0001] The present disclosure relates to a conductive adhesive composition and a method for manufacturing an imaging module.

Background Art

[0002] In order to connect an electronic component to a substrate having fine electrodes, a conductive material or a conductive adhesive containing conductive particles including solder and a binder resin may be used (see, for example, Patent Documents 1 to 3).

[0003] In imaging devices such as digital still cameras and mobile phones with cameras, in order to meet the requirement of thinning the entire product, it is important to reduce the height of the imaging module (see, for example, Patent Document 4).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0005] By using a wafer-level chip size package as a solid-state imaging device, it is expected that the imaging module can be made thinner. However, when joining semiconductor components of a wafer-level chip size package to a wiring board using a conventional lead-free solder (e.g., Sn-Ag-Cu solder), warping tends to occur easily in the imaging module. Especially in the case of an imaging module, even a slight warp can cause distortion of the acquired image, so reducing warp is very important. Furthermore, for an imaging module, it is also required to maintain the initial conductivity even at a high temperature of about 150°C while suppressing warping.

[0006] Therefore, one aspect of the present disclosure provides a conductive adhesive composition that, when used in manufacturing an imaging module having a solid-state imaging device that is a wafer-level chip size package, suppresses warping of the imaging module and can maintain good initial conductivity in a high-temperature resistance test at 150°C.

Means for Solving the Problems

[0007] One aspect of the present disclosure provides a conductive adhesive composition used for manufacturing an imaging module including a wiring board and a semiconductor component having an imaging surface mounted on the wiring board. In other words, one aspect of the present disclosure provides an application of the conductive adhesive composition for manufacturing an imaging module including a wiring board and a semiconductor component having an imaging surface mounted on the wiring board. The solid-state imaging device is a wafer-level chip-scale package. The wiring board has a plurality of connection terminals. The solid-state imaging device has a plurality of connection terminals provided on a surface opposite to the imaging surface. The semiconductor component is mounted on the wiring board in a direction in which the connection terminals of the wiring board and the connection terminals of the solid-state imaging device face each other. The imaging module further includes a connection portion having a conductive portion that electrically connects the connection terminals of the wiring board and the connection terminals of the solid-state imaging device and a cured resin portion formed around the conductive portion. The conductive adhesive composition contains (A) conductive particles, (B) a thermosetting resin, and (C) a flux activator. The flux activator includes a compound having a hydroxyl group and a carboxyl group. The content of the flux activator is 1.0 to 3.9% by mass based on the mass of the conductive particles. The connection portion is formed by the conductive adhesive composition.

[0008] Another aspect of the present disclosure provides a method of manufacturing an imaging module. The method includes preparing a semiconductor component including a wiring substrate having a plurality of connection terminals and a solid-state imaging device having an imaging surface, the solid-state imaging device having a plurality of connection terminals provided on a surface opposite to the imaging surface; disposing the conductive adhesive composition on the connection terminals of the wiring substrate or on the connection terminals of the solid-state imaging device; disposing the semiconductor component on the wiring substrate such that the connection terminals of the wiring substrate and the connection terminals of the solid-state imaging device face each other through the conductive adhesive composition, to obtain a temporary connection body including the wiring substrate, the conductive adhesive composition, and the semiconductor component; and heating the temporary connection body to form a connection portion having a conductive portion formed from conductive particles in the conductive adhesive composition and electrically connecting the connection terminals of the wiring substrate and the connection terminals of the solid-state imaging device, and a resin portion formed around the conductive portion.

Advantages of the Invention

[0009] According to one aspect of the present disclosure, there is provided a conductive adhesive composition that suppresses warping of a photographing module and can maintain good initial conductivity in a high-temperature resistance test at 150°C when used for manufacturing an imaging module having a solid-state imaging device that is a wafer-level chip size package.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0011] Hereinafter, some embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments.

[0012] The conductive adhesive composition according to one embodiment contains (A) conductive particles, (B) a thermosetting resin, and (C) a flux activator, and is used for manufacturing an imaging module including a wiring substrate and a semiconductor component including a solid-state imaging device mounted on the wiring substrate. FIGS. 1 to 6 are schematic cross-sectional views showing one embodiment of the manufactured imaging module.

[0013] The imaging module 101 shown in FIG. 1 mainly includes a wiring substrate 10, a semiconductor component 20, a resin frame portion 30 provided on the wiring substrate 10 and surrounding the semiconductor component 20, a plurality of connection portions 8 disposed between the semiconductor component 20 and the wiring substrate 10 and joining them, a sealing portion 51 filling the space between the semiconductor component 20 and the resin frame portion 30, and an underfill 52 filling the space between the plurality of connection portions 8 between the semiconductor component 20 and the wiring substrate 10. The wiring substrate 10, the semiconductor component 20, and the resin frame portion 30 are integrated via the sealing portion 51 and the underfill 52. The connection portion 8 is formed of the conductive adhesive composition.

[0014] The semiconductor component 20 includes a solid-state imaging device 21 having an imaging surface S1 and a surface (back surface S2) on the opposite side thereof. The solid-state imaging device 21 is a wafer-level chip size package, and includes sensor elements 21A arranged in the imaging surface S1, a color filter 21B covering the sensor elements 21A, and a plurality of connection terminals 21C provided on the back surface S2. The connection terminals 21C contain metal and may be bumps. Specific examples of the solid-state imaging device 21 are a CCD image sensor and a CMOS image sensor. The sensor elements 21A are, for example, photodiodes. The sensor elements 21A are provided by a wafer-level chip size packaging (WLCSP) technique. A plurality of color filters may be provided. A via electrode penetrating between the imaging surface S1 and the back surface S2 of the solid-state imaging device 21 may be provided. In addition, normal configurations constituting the solid-state imaging device are provided as necessary.

[0015] The semiconductor component 20 further includes a plate-shaped light-transmitting member 22 provided on the imaging surface S1. The plate-shaped light-transmitting member 22 may be an inorganic glass plate. The plate-shaped light-transmitting member 22 is fixed to the semiconductor component 20 via a resin adhesive or the like. The thickness of the plate-shaped light-transmitting member 22 may be, for example, 10 to 200 μm. The plate-shaped light-transmitting member 22, the resin frame portion 30, and the sealing portion 51 may form a flat main surface of the imaging module 101 flush with each other.

[0016] The thickness of the solid-state imaging device 21 may be, for example, 50 to 500 μm. The maximum width of the solid-state imaging device 21 may be, for example, 5 to 30 mm. The maximum width of the connection terminals 21C of the solid-state imaging device 21 may be, for example, 100 to 300 μm. When the solid-state imaging device has fine connection terminals, the quality of the imaging module tends to be easily affected by minute warping. However, by using the conductive adhesive composition according to the present embodiment, minute warping can be sufficiently suppressed.

[0017] The wiring board 10 has a plurality of connection terminals arranged on the main surface. The wiring board 10 may be an organic wiring board, a coreless board, or a flexible board. The thickness of the wiring board 10 may be, for example, 50 to 450 μm.

[0018] The semiconductor component 20 is mounted on the wiring board 10 with the connection terminals of the wiring board 10 and the connection terminals 21C of the solid-state imaging device 21 facing each other. The connection portion 8 formed between the connection terminal 21C and the wiring board 10 is composed of a conductive portion 8A that electrically connects the connection terminal of the wiring board 10 and the connection terminal 21C of the solid-state imaging device 21, and a cured resin portion 8B formed around the conductive portion 8A. The conductive portion 8A mainly contains the metal of the conductive particles contained in the conductive adhesive composition. The cured resin portion 8B mainly contains a cured product of an adhesive component containing a thermosetting resin, which was contained in the conductive adhesive composition. However, the cured resin portion 8B may contain a small amount of conductive particles as long as appropriate insulation is maintained. The wiring board 10 and the solid-state imaging device 21 are joined to each other and electrically connected by the connection portion 8. The gap between adjacent connection portions 8 is filled with the underfill 52.

[0019] The ratio of the cured resin portion 8B to the amount of the conductive portion 8A and the filling rate of the underfill 52 can be appropriately changed without departing from the spirit of the present invention. For example, when a cross-section along the thickness direction of the imaging module is viewed at the position where the connection terminal of the solid-state imaging device shows the maximum width, the area ratio of the conductive portion to the cured resin portion may be 5:95 to 80:20. In the case of the imaging module 102 shown in FIG. 2, the ratio of the cured resin portion 8B to the amount of the conductive portion 8A is larger than the ratio in the imaging module 101, and a part of the gap between adjacent connection portions 8 is not filled with the underfill 52. In the case of the imaging module 103 shown in FIG. 3, since the ratio of the cured resin portion 8B to the amount of the conductive portion 8A is even larger, the cured resin portions 8B of adjacent connection portions 8 are integrated, and the space between the semiconductor component 20 and the wiring board 10 is filled with the cured resin portion 8B. In the form shown in FIG. 2 or FIG. 3, since the cured resin portion 8B also functions as an underfill, the generation of cracks in the conductive portion 8A is suppressed.

[0020] In the imaging module, an underfill may not be provided. FIGS. 4, 5, and 6 show examples of imaging modules into which an underfill 52 formed of a sealing material different from the sealing portion 51 is not introduced. In the imaging module 104 shown in FIG. 4, the sealing portion 51 fills the space between the semiconductor component 20 and the resin frame portion 30, and also fills the space between the semiconductor component 20 and the connection portion 8 between the wiring boards 10. In the imaging module 105 shown in FIG. 5, the ratio of the cured resin portion 8B to the amount of the conductive portion 8A is relatively large. In the imaging module 106 shown in FIG. 6, the integrated cured resin portion 8B fills the space between the semiconductor component 20 and the wiring board 10.

[0021] The resin frame portion 30 may be a light-shielding member formed of a resin material. By surrounding the semiconductor component 20 with the light-shielding resin frame portion 30, scattering of light incident on the imaging module can be suppressed. The resin frame portion 30 can be formed, for example, by a transfer molding method or the like using a thermosetting sealing material for semiconductor encapsulation. When light scattering is suppressed, flare and ghost can be suppressed. Various circuit components such as capacitors and chips may be embedded inside the resin frame portion 30.

[0022] In the imaging module exemplified above, the conductive portion 8A is reinforced by the cured resin portion 8B. When the imaging module undergoes a thermal history due to a temperature cycle test, large strains occur in the connection portion and other components due to warping and the like. Since the conductive portion 8A is reinforced by the cured resin portion 8B, the deformation of the wiring board 10 is stopped by the cured resin portion 8B, thereby suppressing the occurrence of cracks in the connection portion 8.

[0023] The imaging module illustrated above can be manufactured, for example, by a method including the steps of preparing a wiring board 10 and a semiconductor component 20 including an image sensor device 21, disposing a conductive adhesive composition on a connection terminal of the wiring board 10 or on a connection terminal 21C of the image sensor device 21, disposing the semiconductor component 20 on the wiring board 10 such that the connection terminal of the wiring board 10 and the connection terminal 21C of the image sensor device 21 face each other through the conductive adhesive composition to obtain a temporary connection body having the wiring board 10, the conductive adhesive composition, and the semiconductor component 20, heating the temporary connection body to form a connection portion 8 having a conductive portion 8A and a cured resin portion 8B, and obtaining a connection structure in which the wiring board 10 and the semiconductor component 20 are joined by the connection portion 8, providing a resin frame portion 30 surrounding the semiconductor component 20 on the wiring board 10, and forming a sealing portion 51 and an underfill 52.

[0024] The conductive adhesive composition can be applied on a connection terminal of the wiring board 10 or on a connection terminal 21C of the image sensor device 21 by any method such as a dispensing method, a screen printing method, or a stamping method. Heating of the temporary connection body can be performed using a heating device such as an oven or a reflow furnace. If necessary, the temporary connection body may be heated under pressure. During the heat curing process of the conductive adhesive composition, usually, the connection portion 8 having the conductive portion 8A and the cured resin portion 8B is formed. The conductive portion 8A includes an aggregate formed by fusion of conductive particles melted by heating. This aggregate joins with the connection terminals of the wiring board and the image sensor device to form a metal connection path. The heating temperature for forming the connection portion is a temperature equal to or higher than the melting point of the metal constituting the conductive particles, and may be, for example, 140 to 180°C.

[0025] The imaging module can be used as a member constituting various electronic devices such as a mobile phone with a camera and a digital camera.

[0026] Details of the conductive adhesive composition used for manufacturing the imaging module will be described below.

[0027] The electrically conductive adhesive composition according to one embodiment contains (A) electrically conductive particles, (B) a thermosetting resin, and (C) a flux activator.

[0028] The electrically conductive particles contain a metal having a melting point of 220°C or lower, or a melting point of 200°C or lower. The melting point of the metal contained in the electrically conductive particles may be 180°C or lower, or 150°C or lower. The lower limit of the melting point of the metal in the electrically conductive particles is not particularly limited, but is about 100°C. When such electrically conductive particles are used in the electrically conductive adhesive composition, they are considered to melt and aggregate at a relatively low temperature, and this aggregate contributes to the electrical connection of the connection terminals. When the metal contained in the electrically conductive particles is an alloy containing two or more metal species, the melting point of the alloy may be 220°C or lower.

[0029] From the viewpoint of reducing environmental load, the metal in the electrically conductive particles may be composed of metals other than lead. Examples of the metal contained in the electrically conductive particles include a single metal selected from tin (Sn), bismuth (Bi), indium (In), and zinc (Zn), or an alloy composed of two or more metal species. From the point of view of obtaining better connection reliability, the alloy may further contain a high melting point component selected from platinum (Pt), gold (Au), silver (Ag), copper (Cu), nickel (Ni), palladium (Pd), aluminum (Al), etc. within the range where the melting point of the entire metal in the electrically conductive particles is 200°C or lower.

[0030] From the viewpoint of reducing environmental load, the metal in the electrically conductive particles is preferably composed of metals other than lead. Examples of the metal contained in the electrically conductive particles include a single metal selected from tin (Sn), bismuth (Bi), indium (In), and zinc (Zn), or an alloy composed of two or more metal species. From the point of view of obtaining better connection reliability, the alloy may further contain a high melting point component selected from platinum (Pt), gold (Au), silver (Ag), copper (Cu), nickel (Ni), palladium (Pd), aluminum (Al), etc. within the range where the melting point of the entire metal in the electrically conductive particles is 200°C or lower.

[0031] Specific examples of the metal constituting the conductive particles include Sn42-Bi58 solder (melting point: 138°C), Sn48-In52 solder (melting point: 117°C), Sn42-Bi57-Ag1 solder (melting point: 139°C), Sn90-Ag2-Cu0.5-Bi7.5 solder (melting point: 189°C), Sn96-Zn8-Bi3 solder (melting point: 190°C), and Sn91-Zn9 solder (melting point: 197°C). These show clear solidification behavior after melting. The solidification behavior means that the metal cools and solidifies after melting. From the viewpoints of easy availability and effects, the conductive particles may contain Sn42-Bi58 solder. These may be used alone or in combination of two or more.

[0032] In the volume-based cumulative particle size distribution of the conductive particles, the cumulative 50% particle size D50 may be 3 to 10 μm. The cumulative particle size distribution here is measured by the laser diffraction / scattering method. When D50 is 3 μm or more, the conductive adhesive composition is likely to have a moderately low viscosity, and good workability can be ensured. Also, the amount of the flux activator required to obtain sufficient fusibility of the conductive particles tends to be small. When the amount of the flux activator is small, the resin cured product formed from the conductive adhesive composition is likely to maintain good physical properties (such as adhesiveness at high temperatures). Furthermore, in the high-temperature resistance test, it is difficult for the cured resin part to be broken due to the expansion of the conductive part containing the metal. When D50 of the conductive particles is 10 μm or less, when connecting the connection terminals arranged at the pitch and the solid-state imaging device, it is difficult for a short circuit between the adjacent connection terminals to occur due to bridging between the adjacent connection terminals. In addition, the conductive adhesive composition can be easily applied to the connection terminals with a small area by any of the printing method, the transfer method, and the dispensing method. From the viewpoint of further improving the coatability and workability of the conductive adhesive composition, D50 of the conductive particles may be 4 to 9 μm. From the viewpoints of improving the storage stability of the conductive adhesive composition and the mounting reliability of the cured product, D50 of the conductive particles may be 5 to 8 μm.

[0033] In the volume-based cumulative particle size distribution of the conductive particles, the cumulative 10% particle size D10 may be 2.4 μm or more. When D10 is 2.4 μm or more, for the same reasons as described above, the amount of the required flux activator tends to be small, and therefore, for example, it is easy to maintain a high level of high-temperature resistance. From the same perspective, the minimum particle size Dmin in the cumulative particle size distribution may be 1.0 μm or more. D10 may be 2.9 μm or less, and Dmin may be 2.5 μm or less.

[0034] In the volume-based cumulative particle size distribution of the conductive particles, the cumulative 90% particle size D90 may be 12 μm or less or 10.5 μm or less. When D90 is 12 μm or less or 10.5 μm or less, the occurrence of a short circuit due to a bridge between the connection terminals tends to be suppressed. From the same perspective, the maximum particle size Dmax may be 20 μm or less. D90 may be 10 μm or more, and Dmax may be 13 μm or more.

[0035] The specific surface area of the conductive particles is 1.45×10 -4 ~8.45×10 -4 cm 2 / g may be acceptable.

[0036] The conductive particles may be metal particles composed only of metal, or composite particles having core particles made of solid materials other than metal such as ceramics, silica, and resin materials, and a metal film covering the surface of the core particles and made of a metal having a melting point of 220°C or lower, or a combination thereof.

[0037] The content of the conductive particles may be 5 to 95% by mass based on the total mass of the conductive adhesive composition. When the content of the conductive particles is less than 5% by mass, the conductivity of the cured product of the conductive adhesive composition tends to decrease. When the content of the conductive particles exceeds 95% by mass, the viscosity of the conductive adhesive composition increases, and thus the workability tends to decrease. Also, since the proportion of the thermosetting adhesive component in the conductive adhesive composition relatively decreases, the mounting reliability also tends to decrease. From the viewpoint of improving workability or conductivity, the content of the conductive particles may be 30 to 90% by mass, and from the viewpoint of enhancing the mounting reliability of the conductive adhesive composition, it may be 40 to 85% by mass.

[0038] The conductive adhesive composition may contain high melting point conductive particles including a metal with a melting point of 220°C or lower or 200°C or lower and a metal with a melting point exceeding 220°C or 200°C. Examples of the metal with a melting point higher than 200°C include a single metal selected from Pt, Au, Ag, Cu, Ni, Pd, Al, and Sn, or an alloy composed of two or more metal species. Specific examples of the high melting point conductive particles include Au powder, Ag powder, Cu powder, Ag-plated Cu powder, Sn powder, and SnAgCu powder. As a commercially available product of the high melting point conductive particles, "MA05K" (trade name, manufactured by Hitachi Chemical Co., Ltd.), which is silver-plated copper powder, is available.

[0039] When combining (A) conductive particles containing a metal with a melting point of 220°C or lower or 200°C or lower and (a1) conductive particles containing a metal with a melting point exceeding 200°C or 220°C, the mass ratio ((A):(a1)) of (A) conductive particles containing a metal with a melting point of 220°C or lower or 200°C or lower to (a1) conductive particles containing a metal with a melting point exceeding 200°C may be in the range of 99:1 to 50:50, or 99:1 to 60:40.

[0040] (B) The thermosetting resin has the function of adhering to the adherend and acts as a binder component that binds the conductive particles in the conductive adhesive composition and the filler added as required to each other. Examples of the thermosetting resin include thermosetting organic polymer compounds such as epoxy resins, (meth)acrylic resins, maleimide resins, and cyanate resins, and their precursors. The (meth)acrylic resin indicates a methacrylic resin and an acrylic resin. The thermosetting resin may be a compound having a polymerizable carbon-carbon double bond represented by the (meth)acrylic resin and the maleimide resin, or an epoxy resin. These thermosetting resins are excellent in heat resistance and adhesiveness, and moreover, can be handled in a liquid state if dissolved or dispersed in an organic solvent as required, so they are also excellent in workability. From the viewpoints of easy availability and reliability, the thermosetting resin may be an epoxy resin. These thermosetting resins are used alone or in combination of two or more.

[0041] Here, the epoxy resin is a compound having two or more epoxy groups. Examples of the epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AD type epoxy resin, and amine type epoxy resin.

[0042] Specific examples of commercially available epoxy resins include AER-X8501 (trade name, manufactured by Asahi Kasei Corporation), R-301 (trade name, manufactured by Mitsubishi Chemical Corporation), and YL-980 (trade name, manufactured by Mitsubishi Chemical Corporation), which are bisphenol A type epoxy resins; YDF-170 (trade name, manufactured by Tohto Kasei Co., Ltd.) and YL-983U (trade name, manufactured by Mitsubishi Chemical Corporation), which are bisphenol F type epoxy resins; R-1710 (trade name, manufactured by Mitsui Petrochemical Industries, Ltd.), which is bisphenol AD type epoxy resin; N-730S (trade name, manufactured by Dainippon Ink and Chemicals, Inc.) and Quatrex-2010 (trade name, manufactured by The Dow Chemical Company), which are phenol novolac type epoxy resins; YDCN-702S (trade name, manufactured by Tohto Kasei Co., Ltd.) and EOCN-100 (trade name, manufactured by Nippon Kayaku Co., Ltd.), which are cresol novolac type epoxy resins; EPPN-501 (trade name, manufactured by Nippon Kayaku Co., Ltd.), TACTIX-742 (trade name, manufactured by The Dow Chemical Company), VG-3010 (trade name, manufactured by Mitsui Petrochemical Industries, Ltd.), and 1032S (trade name, manufactured by Mitsubishi Chemical Corporation), which are polyfunctional epoxy resins; HP-4032 (trade name, manufactured by Dainippon Ink and Chemicals, Inc.), which is an epoxy resin having a naphthalene skeleton; EHPE-3150, CEL-3000 (both trade names, manufactured by Daicel Chemical Industries, Ltd.), DME-100 (trade name, manufactured by Shin Nippon Rika Co., Ltd.), and EX-216L (trade name, manufactured by Nagase ChemteX Corporation), which are alicyclic epoxy resins; W-100 (trade name, manufactured by Shin Nippon Rika Co., Ltd.), which is an aliphatic epoxy resin; ELM-100 (trade name, manufactured by Sumitomo Chemical Co., Ltd.), which is an amine type epoxy resin; YH-434L (trade name, manufactured by Tohto Kasei Co., Ltd.), TETRAD-X, TETRAD-C (both trade names, manufactured by Mitsubishi Gas Chemical Company, Inc.), 630, 630LSD (both trade names, manufactured by Mitsubishi Chemical Corporation), Denacol EX-201 (trade name, manufactured by Nagase ChemteX Corporation), which is a resorcin type epoxy resin; Denacol EX-211 (trade name, manufactured by Nagase ChemteX Corporation), which is a neopentyl glycol type epoxy resin; Denacol EX-212 (trade name, manufactured by Nagase ChemteX Corporation), which is 1,6-hexanediol diglycidyl ether;Denacol EX series (EX-810, 811, 850, 851, 821, 830, 832, 841, 861, all manufactured by Nagase Kasei Kogyo Co., Ltd., trade names), which are ethylene-propylene glycol type epoxy resins; E-XL-24 and E-XL-3L (both manufactured by Mitsui Chemicals, Inc., trade names), which are epoxy resins represented by the following general formula (I).;

[0043] [Chemical formula] In formula (I), k represents an integer from 1 to 5.

[0044] When the thermosetting resin contains an epoxy resin, the conductive adhesive composition may further contain an epoxy compound having one epoxy group as a reactive diluent. Specific examples of commercially available products of the epoxy compound having one epoxy group include PGE (manufactured by Nippon Kayaku Co., Ltd., trade name), PP-101 (manufactured by Tohto Kasei Co., Ltd., trade name), ED-502, ED-509, ED-509S (manufactured by Asahi Denka Kogyo Co., Ltd., trade name), YED-122 (manufactured by Yuka Shell Epoxy Co., Ltd., trade name), KBM-403 (manufactured by Shin-Etsu Chemical Co., Ltd., trade name), TSL-8350, TSL-8355, TSL-9905 (manufactured by Toshiba Silicone Co., Ltd., trade name). These may be used alone or in combination of two or more kinds.

[0045] When the conductive adhesive composition contains a reactive diluent, the content thereof may be in a range that does not significantly inhibit the effects of the present invention, and may be 0.1 to 30% by mass based on the total amount of the epoxy resin.

[0046] The thermosetting resin may contain a (meth)acrylic resin. The (meth)acrylic resin is composed of a compound having a polymerizable carbon-carbon double bond (acryloyl group or methacryloyl group). Examples of such compounds include monoacrylate compounds, monomethacrylate compounds, diacrylate compounds, and dimethacrylate compounds.

[0047] Examples of the monoacrylate compound include methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, t-butyl acrylate, amyl acrylate, isoamyl acrylate, hexyl acrylate, heptyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, nonyl acrylate, decyl acrylate, isodecyl acrylate, lauryl acrylate, tridecyl acrylate, hexadecyl acrylate, stearyl acrylate, isostearyl acrylate, cyclohexyl acrylate, isobornyl acrylate, diethylene glycol acrylate, polyethylene glycol acrylate, polypropylene glycol acrylate, 2-methoxyethyl acrylate, 2-ethoxyethyl acrylate, 2-butoxyethyl acrylate, methoxydiethylene glycol acrylate, methoxypolyethylene glycol acrylate, dicyclopentenyl oxyethyl acrylate, 2-phenoxyethyl acrylate, phenoxydiethylene glycol acrylate, phenoxypolyethylene glycol acrylate, 2-benzoyloxyethyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate, benzyl acrylate, 2-cyanoethyl acrylate, γ-acryloxyethyltrimethoxysilane, glycidyl acrylate, tetrahydrofurfuryl acrylate, dimethylaminoethyl acrylate, diethylaminoethyl acrylate, acryloxyethyl phosphate, and acryloxyethyl phenyl acid phosphate.

[0048] Examples of the monomethacrylate compound include methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, amyl methacrylate, isoamyl methacrylate, hexyl methacrylate, heptyl methacrylate, octyl methacrylate, 2-ethylhexyl methacrylate, nonyl methacrylate, decyl methacrylate, isodecyl methacrylate, lauryl methacrylate, tridecyl methacrylate, hexadecyl methacrylate, stearyl methacrylate, isostearyl methacrylate, cyclohexyl methacrylate, isobornyl methacrylate, diethylene glycol methacrylate, polyethylene glycol methacrylate, polypropylene glycol methacrylate, 2-methoxyethyl methacrylate, 2-ethoxyethyl methacrylate, 2-butoxyethyl methacrylate, methoxydiethylene glycol methacrylate, methoxypolyethylene glycol methacrylate, dicyclopentenyl oxyethyl methacrylate, 2-phenoxyethyl methacrylate, phenoxydiethylene glycol methacrylate, phenoxypolyethylene glycol methacrylate, 2-benzoyloxyethyl methacrylate, 2-hydroxy-3-phenoxypropyl methacrylate, benzyl methacrylate, 2-cyanoethyl methacrylate, γ-methacryloxyethyltrimethoxysilane, glycidyl methacrylate, tetrahydrofurfuryl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, methacryloxyethyl phosphate, and methacryloxyethyl phenyl acid phosphate.

[0049] Examples of the diacrylate compound include ethylene glycol diacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate, 1,3-butanediol diacrylate, neopentyl glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate, tripropylene glycol diacrylate, polypropylene glycol diacrylate, the reaction product of 1 mol of bisphenol A, bisphenol F or bisphenol AD and 2 mols of glycidyl acrylate, the diacrylate of the polyethylene oxide adduct of bisphenol A, bisphenol F or bisphenol AD, the diacrylate of the polypropylene oxide adduct of bisphenol A, bisphenol F or bisphenol AD, bis(acryloxypropyl)polydimethylsiloxane and bis(acryloxypropyl)methylsiloxane-dimethylsiloxane copolymer.

[0050] Examples of the dimethacrylate compound include ethylene glycol dimethacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol dimethacrylate, 1,9-nonanediol dimethacrylate, 1,3-butanediol dimethacrylate, neopentyl glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, tripropylene glycol dimethacrylate, polypropylene glycol dimethacrylate, the reaction product of 1 mol of bisphenol A, bisphenol F or bisphenol AD and 2 mols of glycidyl methacrylate, the dimethacrylate of the polyethylene oxide adduct of bisphenol A, bisphenol F or bisphenol AD, the dimethacrylate of the polypropylene oxide adduct of bisphenol F or bisphenol AD, bis(acryloxypropyl)polydimethylsiloxane and bis(acryloxypropyl)methylsiloxane-dimethylsiloxane copolymer.

[0051] These compounds are used alone or in combination of two or more. When the thermosetting resin contains a (meth)acrylic resin, these compounds may be polymerized in advance before use, or these compounds may be mixed together with conductive particles, flux activators, etc., and polymerization may be carried out simultaneously with the mixing. Compounds having polymerizable carbon-carbon double bonds in these molecules are used alone or in combination of two or more.

[0052] When the thermosetting resin contains a (meth)acrylic resin, the conductive adhesive composition may further contain a radical polymerization initiator. From the viewpoint of effectively suppressing voids, etc., an organic peroxide is preferable as the radical polymerization initiator. From the viewpoint of improving the curability and viscosity stability of the adhesive component, the decomposition temperature of the organic peroxide may be 130°C to 200°C.

[0053] As the radical polymerization initiator, those commonly used can be used. Examples thereof include peroxides such as benzoyl peroxide and t-butyl peroxy-2-ethylhexanoate, and azo compounds such as azobisisobutyronitrile and azobisdimethylvaleronitrile.

[0054] The content of the radical polymerization initiator may be 0.01 to 20% by mass, 0.1 to 10% by mass, or 0.5 to 5% by mass based on the total amount of the conductive adhesive composition.

[0055] Commercially available products can be used as the (meth)acrylic resin. Specific examples thereof include FINEDIC A-261 (manufactured by Dainippon Ink and Chemicals, Incorporated, trade name), and FINEDIC A-229-30 (manufactured by Dainippon Ink and Chemicals, Incorporated, trade name).

[0056] The content of the thermosetting resin in the conductive adhesive composition may be 1 to 60% by mass, 5 to 40% by mass, or 10 to 30% by mass based on the total mass of the conductive adhesive composition.

[0057] (C) The flux activator is a component that exhibits the function of removing the oxide film formed on the surface of the conductive particles. By using such a flux activator, the oxide film that hinders the melting and aggregation of the conductive particles is removed. The flux activator according to one embodiment includes a compound containing a hydroxyl group and a carboxyl group. This compound exhibits good flux activity and can react with an epoxy resin that can be used as a thermosetting resin. A compound having a hydroxyl group and a carboxyl group may be an aliphatic dihydroxycarboxylic acid in that it exhibits good oxide film removal ability even when the particle size of the conductive particles is small and the amount of the oxide film is large. Specifically, the flux activator may include a compound represented by the following general formula (V), tartaric acid, or a combination thereof.

[0058] [Chemical formula]

[0059] In formula (V), R5 represents an alkyl group having 1 to 5 carbon atoms. From the viewpoint of more effectively exerting the above-described effects of the present invention, R5 may be a methyl group, an ethyl group, or a propyl group. n and m each independently represent an integer of 0 to 5. From the viewpoint of more effectively exerting the above-described effects of the present invention, n may be 0 and m may be 1, or both n and m may be 1.

[0060] Examples of the compound represented by the above general formula (V) include 2,2-bis(hydroxymethyl)propionic acid, 2,2-bis(hydroxymethyl)butanoic acid, and 2,2-bis(hydroxymethyl)pentanoic acid. The flux activator may include at least one compound selected from these.

[0061] From the viewpoints of high-temperature resistance and temperature cycle test resistance, etc., the content of the flux activator may be 1.0 to 3.9% by mass, 1.8 to 3.9% by mass, or 1.5 to 3.5% by mass with respect to the amount of the conductive particles. From the viewpoints of the curability of the conductive adhesive composition and void suppression, the content of the flux activator may be 2.5 to 3.5% by mass with respect to the amount of the conductive particles.

[0062] When the thermosetting resin is an epoxy resin, the conductive adhesive composition may further contain a (D) curing catalyst. The (D) curing catalyst is a component that promotes the curing of the epoxy resin. The curing catalyst may contain a compound having an imidazole group from the viewpoints of curability, length of pot life, heat resistance of the cured product, etc. Examples of commercially available products of the compound having an imidazole group include 2P4MHZ-PW (2-phenyl-4-methyl-5-hydroxymethylimidazole), 2PHZ-PW (2-phenyl-4,5-dihydroxymethylimidazole), C11Z-CN (1-cyanoethyl-2-undecylimidazole), 2E4MZ-CN (1-cyanoethyl-2-ethyl-4-methylimidazole), 2PZ-CN (1-cyanoethyl-2-phenylimidazole), 2MZ-A (2,4-diamino-6-[2'methylimidazolyl-(1')]-ethyl-s-triazine), 2E4MZ-A (2,4-diamino-6-[2'-ethyl-4'methylimidazolyl-(1')]-ethyl-s-triazine), 2MAOK-PW (2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanuric acid adduct) (all are products of Shikoku Kasei Co., Ltd., trade names). These curing catalysts may be used alone or in combination of two or more.

[0063] The content of the curing catalyst may be 0.01 to 90 parts by mass or 0.1 to 50 parts by mass with respect to 100 parts by mass of the epoxy resin. When the content of the curing catalyst is less than 0.01 part by mass, the curability tends to decrease, and when the content of the curing catalyst exceeds 90 parts by mass, the viscosity increases, and the workability when handling the conductive adhesive composition tends to decrease.

[0064] The conductive adhesive composition may further contain a curing agent to adjust the curing rate of the epoxy resin.

[0065] The curing agent is not particularly limited as long as it is conventionally used, and commercially available products are available. Examples of commercially available curing agents include, for example, H-1 (trade name, manufactured by Meiwa Kasei Co., Ltd.) and VR-9300 (trade name, manufactured by Mitsui Toatsu Chemicals, Inc.), which are phenol novolac resins, XL-225 (trade name, manufactured by Mitsui Toatsu Chemicals, Inc.), which is a phenol aralkyl resin, MTPC (trade name, manufactured by Honshu Chemical Industry Co., Ltd.), which is a p-cresol novolac resin represented by the following general formula (II), AL-VR-9300 (trade name, manufactured by Mitsui Toatsu Chemicals, Inc.), which is an allylated phenol novolac resin, and PP-700-300 (trade name, manufactured by Nippon Petrochemical Co., Ltd.), which is a special phenol resin represented by the following general formula (III).

[0066]

Chemical formula

[0067] In formula (II), a plurality of R1 each independently represent a monovalent hydrocarbon group, which may be a methyl group or an allyl group. q represents an integer of 1 to 5. In formula (III), R2 represents an alkyl group, which may be a methyl group or an ethyl group. R3 represents a hydrogen atom or a monovalent hydrocarbon group, and p represents an integer of 2 to 4.

[0068] As the curing agent, dicyandiamide and the like, which have been conventionally used as curing agents, can also be used, and commercially available products are available. Examples of commercially available products include, for example, ADH, PDH, and SDH (all trade names, manufactured by Nippon Hydrazine Industry Co., Ltd.), which are dibasic acid dihydrazides represented by the following general formula (IV), and Novacure (trade name, manufactured by Asahi Kasei Corporation), which is a microcapsule type curing agent composed of a reaction product of an epoxy resin and an amine compound. These curing agents are used alone or in combination of two or more.

[0069]

Chemical formula

[0070] In formula (IV), R4 represents a divalent aromatic group or a linear or branched alkylene group having 1 to 12 carbon atoms, and may be an m-phenylene group or a p-phenylene group.

[0071] From the viewpoints of storage stability and curing time, the conductive adhesive composition may not substantially contain a curing agent. "Not substantially containing" means that the content is 0.05% by mass or less based on the total mass of the conductive adhesive composition.

[0072] The conductive adhesive composition may contain a filler. Examples of the filler include polymer particles such as acrylic rubber and polystyrene; inorganic particles such as diamond, boron nitride, aluminum nitride, alumina, and silica. These fillers may be used alone or in combination of two or more.

[0073] In addition to the above components, the conductive adhesive composition may optionally contain one or more additives selected from the group consisting of a flexibilizer for stress relaxation, a diluent for improving workability, an adhesion improver, a wettability improver, and an antifoaming agent.

[0074] Examples of the flexibilizer include liquid polybutadiene (manufactured by Ube Industries, Ltd., trade names "CTBN-1300×31" and "CTBN-1300×9"; manufactured by Nippon Soda Co., Ltd., trade name "NISSO-PB-C-2000"). The content of the flexibilizer may be 0.1 to 500 parts by mass based on 100 parts by mass of the thermosetting resin.

[0075] Examples of diluents include relatively high-boiling organic solvents such as butyl carbitol, butyl carbitol acetate, butyl cellosolve, carbitol, butyl cellosolve acetate, carbitol acetate, dipropylene glycol monomethyl ether, ethylene glycol diethyl ether, and α-terpineol. The content of the diluent may be 0.1 to 30% by mass based on the total mass of the conductive adhesive composition.

[0076] The adhesion improver may be a coupling agent such as a silane coupling agent or a titanium coupling agent. Examples of the silane coupling agent include, for example, the product named "KBM-573" manufactured by Shin-Etsu Chemical Co., Ltd. The wetting improver may be, for example, an anionic surfactant or a fluorine-based surfactant. The defoaming agent may be, for example, silicone oil. The adhesion improver, the wetting improver, and the defoaming agent are each used alone or in combination of two or more. Their contents may be 0.1 to 10% by mass based on the total mass of the conductive adhesive composition.

[0077] Any combination of the exemplified components described above may be used.

[0078] The conductive adhesive composition is obtained by heating the above-described components once or in multiple portions as needed, and mixing, dissolving, granule-dissolving and kneading, or dispersing them. The conductive adhesive composition may be in the form of a paste in which each component is uniformly dispersed. Examples of the dispersion / dissolution apparatus used at this time include known stirrers, disintegrators, three-roll mills, planetary mixers, and the like. The conductive adhesive composition may be in the form of a paste at 25°C and have a viscosity of 5 to 400 Pa·s.

[0079] According to the conductive adhesive composition of the present embodiment described above, it is possible to connect semiconductor components with good conductivity to a wiring board having connection terminals such as small-area electrode pads or electrodes arranged at a pitch, without causing a short circuit between the electrodes. The connection portion formed by the conductive adhesive composition of the present embodiment can have a conductive portion containing conductive particles and a cured resin portion formed from an insulating adhesive component. The reinforcement by the cured resin portion can contribute to improving the high-temperature resistance and the temperature cycle test resistance of the imaging module.

[0080] As described above, the preferred embodiments of the present invention have been described, but the present invention is not limited to the above embodiments. The present invention can be variously modified without departing from the gist thereof.

Examples

[0081] Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples.

[0082] 1. Materials (A) Conductive particles · STC-7: Sn42-Bi58 particles (D50: 8.0 μm, D10: 5.3 μm, D90: 10.3 μm, manufactured by Mitsui Mining & Smelting Co., Ltd., melting point 138 °C) · STC-5: Sn42-Bi58 particles (D50: 6.4 μm, D10: 4.6 μm, D90: 8.7 μm, manufactured by Mitsui Mining & Smelting Co., Ltd., melting point 138 °C) · STC-3: Sn42-Bi58 particles (D50: 4.1 μm, D10: 2.7 μm, D90: 6.0 μm, manufactured by Mitsui Mining & Smelting Co., Ltd., melting point 138 °C) · ST-7: Sn42-Bi58 particles (D50: 7.1 μm, D10: 3.6 μm, D90: 10.6 μm, manufactured by Mitsui Mining & Smelting Co., Ltd., melting point 138 °C) · ST-5: Sn42-Bi58 particles (D50: 5.3 μm, D10: 2.3 μm, D90: 8.5 μm, manufactured by Mitsui Mining & Smelting Co., Ltd., melting point 138 °C) · ST-3: Sn42-Bi58 particles (D50: 3.1 μm, D10: 1.7 μm, D90: 5.0 μm, manufactured by Mitsui Mining & Smelting Co., Ltd., melting point 138 °C) · Type6: Sn42-Bi58 particles (average particle size 10 μm, maximum particle size: 18.0 μm, manufactured by Mitsui Mining & Smelting Co., Ltd., melting point 138 °C) · Sn42-Bi57-Ag1 particles (average particle size 5 μm, D10: 2.2 μm, D90: 8.6 μm) (B) Thermosetting resin · YL980 (manufactured by Mitsubishi Chemical Corporation, trade name of bisphenol A type epoxy resin) (C) Flux activator · BHPA: 2,2-bis(hydroxymethyl)propionic acid · BHBA: 2,2-bishydroxymethylbutanoic acid · Tartaric acid · Glutaric acid · Adipic acid (D) Curing catalyst · 2P4MHZ-PW (manufactured by Shikoku Kasei Co., Ltd., trade name of imidazole compound)

[0083] 2. Conductive adhesive composition Example 1 15.2 parts by mass of YL980, 0.8 part by mass of 2P4MHZ-PW, and 3.0 parts by mass of BHPA were mixed, and the mixture was passed through a three-roll mill three times. Subsequently, 81 parts by mass of STC-7, which is Sn42-Bi58 particles, was added to 19 parts by mass of the mixture. The mixture was stirred using a planetary mixer and degassed at 500 Pa or less for 10 minutes to obtain a conductive adhesive composition.

[0084] Examples 2 to 39, Comparative Examples 1 to 14 Conductive adhesive compositions of Examples 2 to 39 and Comparative Examples 1 to 14 were obtained in the same manner as in Example 1, except that the mixing ratios (parts by mass) were changed as shown in Tables 1 to 6.

[0085] Comparative Examples 15, 16 The following commercially available conductive adhesives were prepared. Comparative Example 15: Sn42-Bi58 cream solder (manufactured by Senju Metal Industry Co., Ltd., Eco Solder (trade name)) Comparative Example 16: Sn96.5-Ag3-Cu0.5 cream solder (manufactured by Senju Metal Industry Co., Ltd., Eco Solder (trade name))

[0086] 3. Fabrication of evaluation modules Evaluation modules A to C A semiconductor component composed of a solid-state imaging device having a 5.4 mm × 7.3 mm flake-shaped semiconductor chip and a glass plate provided on the imaging surface of the solid-state imaging device was prepared. A plurality of bumps as connection terminals were provided on the surface (back surface) opposite to the imaging surface of the solid-state imaging device. An organic wiring board (PI board) having land pads provided at positions corresponding to the bumps of the solid-state imaging device as connection terminals was prepared. A resin frame portion was provided on the organic wiring board.

[0087] A conductive adhesive composition was applied to the land pads of the organic wiring board by printing using a metal mask. The semiconductor component was placed on the organic wiring board inside the resin frame portion so that the bumps faced the land pads through the applied conductive adhesive composition. The obtained temporary connection body was heated for 10 minutes under a nitrogen atmosphere at a maximum temperature of 150 °C using a reflow apparatus to form a connection portion that connected the semiconductor component and the organic wiring board to the conductive adhesive composition. Next, a liquid encapsulant (Cell-C-3730, manufactured by Hitachi Chemical Co., Ltd.) was poured between the semiconductor component and the resin frame portion using a dispenser, and the liquid encapsulant was cured by heating at 130 °C for 4 hours in a thermostatic bath to form a sealing portion that filled the space between the semiconductor component and the resin frame portion. By the above procedure, evaluation modules were obtained.

[0088] By changing the thickness of the metal mask used for applying the conductive adhesive composition as follows, evaluation modules A, B, and C with different thicknesses of the conductive adhesive composition and the connection portions formed therefrom were fabricated. · Evaluation module A: 80 μm · Evaluation module B: 120 μm · Evaluation module C: 200μm The evaluation module A has the same configuration as the imaging module 104 in FIG. 4. The evaluation module B has the same configuration as the imaging module 105 in FIG. 5. The evaluation module C has the same configuration as the imaging module 106 in FIG. 6.

[0089] 4. Evaluation The warpage amount, high-temperature resistance at 150°C, and TCT resistance (temperature cycle test resistance) of the evaluation module were evaluated by the following methods. The evaluation results are summarized in Tables 1 to 6. In the tables, "flux / metal ratio (%)" means the ratio (mass%) of the flux activator to the amount of conductive particles.

[0090] (1) Warpage amount The shape of the surface on the side opposite to the connection terminals of the semiconductor components used in the production of the evaluation module was measured using a warpage measuring device (manufactured by AKROMETRIX, product name: THERMOIRE PS200), and the maximum and minimum values of the displacement were obtained, and the difference value was used as the initial shape value. The shape of the surface on the side opposite to the connection terminals of the semiconductor components constituting the evaluation module was similarly measured, and the maximum and minimum values of the displacement were obtained, and the difference value was used as the shape value after mounting. The value obtained by subtracting the initial shape value from the shape value after mounting was recorded as the warpage amount.

[0091] (2) High-temperature resistance The connection resistance value of the evaluation module was confirmed using a simple tester and used as the initial resistance value. Then, the evaluation module was held at 150°C for 96 hours using a high-temperature tester. After that, the connection resistance value of the evaluation module was measured, and the change rate with respect to the initial resistance value of that value was obtained. When the change rate was within ±5%, it was determined as "good", and when the change rate was a value greater than ±5%, it was determined as "bad".

[0092] (3) TCT resistance The connection resistance value of the evaluation module was measured using a simple tester and used as the initial resistance value. Subsequently, the evaluation module was subjected to a thermal shock test using a thermal shock tester, with a temperature cycle consisting of holding at -55°C for 30 minutes, heating to 125°C in 5 minutes, holding at 125°C for 30 minutes, and cooling to -55°C in 5 minutes. The connection resistance value of the evaluation module after the thermal shock test was measured. The connection resistance value of the evaluation module was measured while increasing the number of cycles, and the maximum number of cycles for which the change rate with respect to the initial resistance value remained within ±10% was used as an index of TCT resistance.

[0093]

Table 1

[0094]

Table 2

[0095]

Table 3

[0096]

Table 4

[0097]

Table 5

[0098]

Table 6

[0099] Comparative Example 17 A liquid flux material was applied to the land pads of the organic wiring board. Subsequently, without using a conductive adhesive composition, the semiconductor component was placed on the organic wiring board inside the resin frame portion so that the bumps faced the land pads. The obtained structure was heated for 10 minutes under a nitrogen atmosphere at a maximum temperature of 260 °C using a reflow apparatus to connect the land pads and the bumps. Next, a liquid encapsulant (Cell-C-3730, manufactured by Hitachi Chemical Co., Ltd.) was poured between the semiconductor component and the resin frame portion using a dispenser, and the liquid encapsulant was cured by heating at 130 °C for 4 hours to form a sealing layer that filled the space between the semiconductor component and the resin frame portion. By the above procedure, the evaluation module D was obtained. The warpage amount, TCT resistance, and high-temperature resistance of the evaluation module D were evaluated in the same manner as described above. The warpage amount was 32 μm, the high-temperature resistance was good, and the TCT resistance was 800 cycles.

[0100] Examples 1 to 39 showed good characteristics in terms of the warpage amount and high-temperature resistance at 150 °C. Examples 1 to 23 were also excellent in terms of TCT resistance. In Comparative Examples 1 to 15, the high-temperature resistance at 150 °C was insufficient. In Comparative Examples 16 and 17, the warpage amount was large.

Explanation of Signs

[0101] 8... connection part, 8A... conductive part, 8B... cured resin part, 10... wiring board, 20... semiconductor component, 21A... sensor element, 21B... color filter, 22... plate-shaped light-transmitting member, 30... resin frame part, 21... solid-state imaging device, 21C... connection terminal, 51... sealing part, 52... underfill, 101, 102, 103, 104, 105, 106... imaging module, S1... image-receiving surface, S2... back surface.

Claims

1. A conductive adhesive composition used for manufacturing an imaging module including a wiring board and a semiconductor component having an imaging surface mounted on the wiring board, wherein the solid-state imaging device is a wafer-level chip size package, the wiring board has a plurality of connection terminals, the solid-state imaging device has a plurality of connection terminals provided on a surface opposite to the imaging surface, and the semiconductor component is mounted on the wiring board with the connection terminals of the wiring board and the connection terminals of the solid-state imaging device facing each other, the imaging module further includes a connection portion having a conductive portion that electrically connects the connection terminals of the wiring board and the connection terminals of the solid-state imaging device and a cured resin portion formed around the conductive portion, the conductive adhesive composition contains (A) conductive particles containing a metal, (B) a thermosetting resin, and (C) a flux activator, the flux activator includes a compound having a hydroxyl group and a carboxyl group, the content of the flux activator is 1.0 to 3.9% by mass based on the mass of the conductive particles, the conductive particles contain a metal having a melting point of 220° C. or lower, in the volume-based cumulative particle size distribution of the conductive particles, the cumulative 50% particle size D50 is 3 to 10 μm, the connection portion is formed by the conductive adhesive composition, a conductive adhesive composition.

2. The conductive adhesive composition according to claim 1, wherein the imaging module further includes a resin frame portion provided on the wiring board and surrounding the semiconductor component.

3. The conductive adhesive composition according to claim 2, wherein the imaging module further includes a sealing portion filling between the semiconductor component and the resin frame portion.

4. The conductive adhesive composition according to any one of claims 1 to 3, wherein the imaging module further has an underfill filling between the semiconductor component and the wiring board and between a plurality of the connection portions.

5. The conductive adhesive composition according to any one of claims 1 to 4, wherein the content of the flux activator is 1.8 to 3.9% by mass based on the mass of the conductive particles.

6. The conductive adhesive composition according to any one of claims 1 to 5, wherein the conductive particles contain a metal having a melting point of 200° C. or lower.

7. The conductive adhesive composition according to any one of claims 1 to 5, wherein the conductive particles contain at least one metal selected from bismuth, indium, tin, and zinc.

8. The electroconductive adhesive composition according to any one of claims 1 to 7, wherein in the volume-based cumulative particle size distribution of the electroconductive particles, the cumulative 10% particle size D10 is 2.4 μm or more.

9. The electroconductive adhesive composition according to any one of claims 1 to 8, wherein in the volume-based cumulative particle size distribution of the electroconductive particles, the cumulative 90% particle size D90 is 10.5 μm or less.

10. The electroconductive adhesive composition according to any one of claims 1 to 9, wherein in the volume-based cumulative particle size distribution of the electroconductive particles, the minimum particle size Dmin is 1.0 μm or more.

11. The electroconductive adhesive composition according to any one of claims 1 to 10, wherein in the volume-based cumulative particle size distribution of the electroconductive particles, the maximum particle size Dmax is 20 μm or less.

12. The electroconductive adhesive composition according to any one of claims 1 to 11, wherein the thermosetting resin contains an epoxy resin.

13. The electroconductive adhesive composition according to claim 12, further containing (D) a curing catalyst.

14. The electroconductive adhesive composition according to any one of claims 1 to 13, wherein the electroconductive adhesive composition is in a paste form at 25°C.

15. A semiconductor component including a wiring board having a plurality of connection terminals and a solid-state imaging device having an imaging surface, wherein the solid-state imaging device has a plurality of connection terminals provided on a surface opposite to the imaging surface, preparing the semiconductor component, and disposing the electroconductive adhesive composition according to any one of claims 1 to 14 on the connection terminals of the wiring board or on the connection terminals of the solid-state imaging device; a step of disposing the semiconductor component on the wiring board so that the connection terminals of the wiring board and the connection terminals of the solid-state imaging device face each other through the electroconductive adhesive composition, to obtain a temporary connection body having the wiring board, the electroconductive adhesive composition, and the semiconductor component; a step of forming a connection portion having a conductive portion formed from the electroconductive particles in the electroconductive adhesive composition and electrically connecting the connection terminals of the wiring board and the connection terminals of the solid-state imaging device, and a cured resin portion formed around the conductive portion, by heating the temporary connection body; A method for manufacturing an imaging module, including the above steps.

Images