KR102758192B1 - Adhesive composition - Google Patents

Abstract

An adhesive composition is provided which achieves high reliability. The adhesive composition contains silicone particles, a silane coupling agent, a polymerizable compound, and a curing agent, and the total surface area of spherical particles calculated from the average particle diameter of the silicone particles is 10 × 10 ³ m2 or more per 100 g of the composition. As a result, moisture permeability is improved and high reliability can be achieved.

Description

Adhesive composition

The present technology relates to, for example, an adhesive composition for connecting an IC (Integrated Circuit) chip and a flexible wiring board. This application claims priority from Japanese Patent Application No. Special Application No. 2019-068612, filed in Japan on March 29, 2019, which is incorporated herein by reference.

In the past, for example, in a device that connected an LCD (Liquid Crystal Display) driver IC to a flexible wiring board, when the device was heated, there were cases where moisture that had entered the device expanded rapidly and destroyed the device.

To solve this problem, Patent Document 1 proposes using a sealant having a moisture permeability of 5 to 6 g/㎡·24 h or less for exposed wiring drawn out from the inside of a display panel.

In addition, Patent Document 2 describes a form in which a moisture-proof material is formed on a base film of an electrode connection portion of a flexible wiring board and a lead electrode is formed thereon, a form in which the space between lead electrodes formed in the electrode connection portion of a flexible wiring board is covered with a moisture-proof material, and it is proposed to use a moisture-proof material having a moisture permeability of 10 g/㎡·24 h or less as the moisture-proof material.

Japanese Patent Publication No. 2000-090840 Japanese Patent Publication No. 2004-327873

The methods described in the above-mentioned patent documents 1 and 2 improve moisture resistance by using a sealing resin with low moisture permeability for wiring (outer lead). However, when using a sealing resin with low moisture permeability, an increase in the material score or limitations in material selection occur, so it is difficult to obtain high reliability in the HAST (Highly Accelerated Temperature and Humidity Stress Test), which is one of the test methods for evaluating moisture resistance.

The present technology provides an adhesive composition that achieves high reliability by solving the aforementioned problems.

The inventor of the present invention has conducted research on the formulation of an adhesive composition that can obtain high moisture permeability in order to immediately discharge moisture that has entered the inside of a device. As a result, the inventor has completed this technology based on the finding that moisture permeability is improved by blending a predetermined amount of silicone particles and a silane coupling agent.

That is, the adhesive composition related to the present technology contains silicone particles, a silane coupling agent, a polymerizable compound, and a curing agent, and the sum of the surface areas of the spherical particles calculated from the average particle diameter of the silicone particles is 10 × 10 ³ m2 or more per 100 g of the composition.

In addition, a method for manufacturing a connector related to the present technology includes a placing step of placing a first electronic component and a second electronic component through an adhesive composition containing silicon particles, a silane coupling agent, a polymerizable compound, and a curing agent, wherein the total surface area of spherical particles calculated from the average particle diameter of the silicon particles is 10 × 10 ³ m2 or more per 100 g of the composition, and a curing step of pressing the second electronic component to the first electronic component using a pressing tool and curing the adhesive composition.

In addition, a connector related to the present technology comprises a first electronic component, a second electronic component, and an adhesive film in which the first electronic component and the second electronic component are adhered, wherein the adhesive film is formed by curing an adhesive composition containing silicon particles, a silane coupling agent, a polymerizable compound, and a curing agent, and wherein the total surface area of spherical particles calculated from the average particle diameter of the silicon particles is 10 × 10 ³ m2 or more per 100 g of the composition, and has a moisture permeability of 80 g/m2·24 hr or more.

According to this technology, by mixing a predetermined amount of silicone particles and a silane coupling agent, moisture permeability is improved and high reliability can be obtained.

Fig. 1 is a cross-sectional view schematically showing the arrangement process of a method for manufacturing a connecting body according to the present embodiment.

Hereinafter, embodiments of the present technology will be described in detail in the following order with reference to the drawings.

1. Adhesive composition

2. Manufacturing method of connector

3. Example

＜1. Adhesive composition＞

An adhesive composition related to the present embodiment contains silicone particles, a silane coupling agent, a polymerizable compound, and a curing agent, and the total surface area of the spherical particles calculated from the average particle diameter of the silicone particles is 10 × 10 ³ m2 or more per 100 g of the composition. As a result, moisture permeability is improved, and high reliability can be obtained in the HAST (Highly Accelerated Temperature and Humidity Stress Test), which is one of the test methods for evaluating moisture resistance.

The adhesive composition may be either a film or a paste. From the standpoint of ease of handling, a film is preferable, and from the standpoint of cost, a paste is preferable. In addition, as the curing type of the adhesive composition, examples thereof include a heat curing type, a photocuring type, a photothermal combined curing type, etc., and can be appropriately selected depending on the intended use.

Hereinafter, a heat-curable adhesive composition will be described as an example. As the heat-curable type, for example, a cation-curable type, an anion-curable type, a radical-curable type, or a combination thereof can be used. As the polymerizable compound, an epoxy compound having an ionic polymerization group (cation polymerization, an anion polymerization), an oxetane compound, a (meth)acrylic compound having a radical polymerization group, etc. can be mentioned, and these can be used alone or in combination of two or more. In addition, as the silane coupling agent, a silane coupling agent having a functional group such as an epoxy group, a (meth)acrylic group, or a vinyl group can be mentioned, and it can be appropriately selected depending on the type of the polymerizable compound.

As a specific example of a heat-curable type, an anion-curable epoxy resin composition is shown. The adhesive composition shown as a specific example contains silicone particles, an epoxy silane coupling agent, an epoxy compound, and an epoxy curing agent. Thereby, an epoxy adhesive having high moisture permeability can be obtained.

Examples of the silicone particles include silicone rubber powder having a cross-linked structure of organopolysiloxane, silicone resin powder having a three-dimensional network-like structure in which siloxane bonds are cross-linked as (RSiO _3/2 ) _n , and silicone composite powder which is a spherical powder in which the surface of a spherical silicone rubber powder is covered with silicone resin. One of these can be used alone or two or more can be used in combination. Of these, from the viewpoint of dispersibility, it is preferable that the silicone particles include a silicone composite powder. Specific examples of silicone composite powders available on the market include product names such as “KMP-600”, “KMP-605”, and “X-52-7030” manufactured by Shin-Etsu Chemical Co., Ltd.

The average particle size of the silicone particles is preferably 5 ㎛ or less, more preferably 3 ㎛ or less, and even more preferably 1 ㎛ or less. This makes it possible to increase the total surface area of the spherical particles calculated from the average particle size of the silicone particles in the adhesive composition.

The sum of the surface areas of the spherical particles calculated from the average particle diameter of the silicone particles is 10 × 10 ³ m2 or more per 100 g of the composition, more preferably 25 × 10 ³ m2 or more and 150 × 10 ³ m2 or less per 100 g of the composition, and even more preferably 50 × 10 ³ m2 or more and 150 × 10 ³ m2 or less per 100 g of the composition. As the sum of the surface areas of the spherical particles calculated from the average particle diameter of the silicone particles increases, the moisture permeability increases, but the adhesive strength tends to decrease.

In addition, the sum of the surface areas of the spherical particles calculated from the average particle diameter of the silicone particles in the adhesive composition can be calculated from, for example, the specific surface area of the silicone particles and the amount of the silicone particles added. In addition, the specific surface area of the silicone particles can be obtained from, for example, the surface area per particle calculated from the average particle diameter and the mass per particle calculated from the average particle diameter and the true specific gravity.

The amount of silicone particles blended is preferably 1 to 30 parts by mass, for example, based on 100 parts by mass of the adhesive composition excluding the silicone particles, more preferably 5 to 30 parts by mass, and even more preferably 10 to 30 parts by mass. In addition, when conductive particles are blended into the adhesive composition, the range is the mass parts based on 100 parts by mass of the adhesive composition excluding the conductive particles.

An epoxy-based silane coupling agent is an organic silicon compound having both an epoxy group and a hydrolyzable group, and chemically bonds silicon particles and an epoxy resin, which is a matrix resin, to improve dispersibility.

Examples of epoxy-based silane coupling agents include silane compounds having an epoxy structure, such as 3-glycidoxypropyltrimethoxysilane and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane. Specific examples of epoxy-based silane coupling agents available on the market include “A-187” from Momentive Performance Materials Japan (Co., Ltd.).

The amount of the epoxy silane coupling agent blended is preferably 0.1 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, and even more preferably 0.5 to 1 part by mass, per 100 parts by mass of the adhesive composition excluding the silicone particles.

As the epoxy compound, examples thereof include, but are not limited to, naphthalene-type epoxy compounds, glycidyl ether-type epoxy compounds, glycidyl ester-type epoxy compounds, alicyclic epoxy compounds, bisphenol A-type epoxy compounds, bisphenol F-type epoxy compounds, dicyclopentadiene-type epoxy compounds, novolacphenol-type epoxy compounds, biphenyl-type epoxy compounds, and the like. One of these may be used singly, or two or more may be used in combination. Specific examples of naphthalene-type difunctional epoxy resins available on the market include "HP4032D" from DIC Co., Ltd.

The amount of the epoxy compound blended is preferably 1 to 30 parts by mass, more preferably 1 to 20 parts by mass, and even more preferably 1 to 10 parts by mass, per 100 parts by mass of the adhesive composition excluding the silicone particles.

Examples of the epoxy curing agent include imidazoles, polyhydric phenols, acid anhydrides, amines, hydrazides, polymercaptans, and Lewis acid-amine complexes, and one of these may be used alone or in combination of two or more. Among these, from the viewpoints of storage stability and heat resistance of the cured product, it is more preferable that the epoxy curing agent contains imidazoles. Furthermore, from the viewpoints of storage stability and usable time, it is preferable to use a microcapsule-type latent curing agent in which the epoxy curing agent is coated with a polyurethane- or polyester-based polymer material and microcapsulated. Examples of imidazole-based latent curing agents available on the market include "HP3941" from Asahi Kasei Chemicals Co., Ltd.

The amount of the epoxy curing agent to be mixed is preferably 5 to 70 parts by mass, more preferably 10 to 60 parts by mass, and even more preferably 20 to 50 parts by mass, per 100 parts by mass of the adhesive composition excluding the silicone particles.

In addition, it is preferable that the adhesive composition shown as a specific example contains a polymer and rubber component.

Examples of the polymer include bisphenol A type phenoxy resin, bisphenol F type phenoxy resin, bisphenol S type phenoxy resin, phenoxy resin having a fluorene skeleton, polystyrene, polyacrylonitrile, polyphenylene sulfide, polytetrafluoroethylene, polycarbonate, etc., and these can be used alone or in combination of two or more. Among these, bisphenol A type phenoxy resin is preferably used from the viewpoints of film formation state, connection reliability, etc. Phenoxy resin is a polyhydroxypolyether synthesized from bisphenols and epichlorohydrin. Specific examples of phenoxy resins available on the market include the trade name "YP-50" of Nippon-Steel Sumitomo Chemical Co., Ltd.

The amount of the polymer blended is preferably, for example, parts by mass, more preferably 10 to 60 parts by mass, and even more preferably 20 to 50 parts by mass, per 100 parts by mass of the adhesive composition excluding the silicone particles.

Examples of rubber components include acrylic rubber (ACR), butadiene rubber (BR), nitrile rubber (NBR), etc., and these can be used alone or in combination of two or more. Among these, acrylic rubber is preferably used from the viewpoints of film formation state, connection reliability, etc. Specific examples of acrylic rubber available on the market include the product name "SG80H" of Nagase Chemtex Co., Ltd.

In addition, it is preferable to contain elastic particles as the rubber component. The elastic particles can absorb internal stress and, furthermore, do not cause curing inhibition, so that high connection reliability can be imparted. Examples of the elastic particles include crosslinked acrylonitrile butadiene rubber particles, crosslinked styrene butadiene rubber particles, acrylic rubber particles, silicone particles, and the like. Specific examples of crosslinked acrylonitrile butadiene rubber particles available on the market include XER-91 (average particle size 0.5 ㎛, manufactured by JSR).

The amount of the rubber component blended is preferably 1 to 30 parts by mass, more preferably 5 to 25 parts by mass, and even more preferably 10 to 20 parts by mass, per 100 parts by mass of the adhesive composition excluding the silicone particles.

The minimum melting viscosity of the adhesive composition is preferably 1 to 100,000 ㎩ s, more preferably 10 to 10,000 ㎩ s. If the minimum melting viscosity is too high, the binder between the electrodes cannot be sufficiently excluded during thermal compression, so that the connection resistance tends to increase. On the other hand, if the minimum melting viscosity is too low, the deformation of the adhesive composition due to weighting during thermal compression becomes large, so that when the pressure is released, the restoring force of the adhesive composition is applied as a force in the peeling direction to the interface of the connection part, etc. For this reason, the connection resistance tends to increase immediately after thermal compression, or air bubbles tend to form at the connection part.

An adhesive composition having such a configuration has a moisture permeability measured under the conditions of a temperature of 40° C. and a relative humidity of 90% after curing of preferably 80 g/m2·24 hr or more, more preferably 85 g/m2·24 hr or more, and even more preferably 90 g/m2·24 hr or more. Thereby, moisture that has penetrated into the inside of a device bonded with the adhesive composition can be immediately discharged, and high reliability in HAST can be obtained. In addition, the moisture permeability can be measured under the conditions of 40° C. and a relative humidity of 90% in accordance with the moisture permeability test method for moisture-proof packaging materials (cup method) of JIS Z 0208.

According to such an adhesive composition, since moisture that has penetrated into the device can be immediately discharged, excellent connection reliability can be obtained. In the case of imparting water resistance, the penetrated moisture remains. In other words, it can be said that instead of allowing a certain amount of moisture to penetrate, retention of moisture that excessively promotes deterioration of the adhesiveness is not permitted. Since the required water resistance conditions can be adjusted, there is an effect of expanding the selectivity of the design conditions of the device and the equipment mounting it. For example, in addition to portable terminals and wearable terminals that require weather resistance, there is an advantage that it can be used in the battlefield of vehicles such as motorcycles, automobiles, flying devices (such as drones and airplanes), and ships that are assumed to require higher weather resistance.

In addition, the adhesive composition may be a conductive adhesive that additionally contains conductive particles having an average particle diameter larger than the average particle diameter of the silicone particles. When containing conductive particles, the average particle diameter of the conductive particles is preferably larger than the average particle diameter of the solid compound other than the conductive particles so as not to interfere with the pinching. The ratio of the average particle diameter of the conductive particles to the average particle diameter of the silicone particles is preferably 1.5 or more, more preferably 2.0 or more, and even more preferably 3.5 or more, from the viewpoint of conductivity. This is preferably a large value so that the silicone particles do not interfere with the compression or flattening of the conductive particles. On the other hand, when the conductive particles are pinched between the electrodes, in order to assist in tearing oxides, etc. on the electrodes, it is sometimes desirable to pinch the silicon particles together with the compressed or flattened conductive particles, so the value is sometimes desirable to be small. It is preferably 1.1 or less, more preferably 1.07 or less, and even more preferably 1.05 or less. These may be appropriately adjusted according to the purpose.

The conductive adhesive may be either a film-shaped conductive film or a paste-shaped conductive paste. From the standpoint of ease of handling, a conductive film is preferable, and from the standpoint of cost, a conductive paste is preferable. In addition, the conductive adhesive and the conductive film may be used as an anisotropic conductive adhesive and an anisotropic conductive film. In addition, the structure of these may be an anisotropic connection structure.

As the conductive particles, known conductive particles used in conductive films can be used. For example, particles of various metals such as nickel, iron, copper, aluminum, tin, lead, chromium, cobalt, silver, and gold, or metal alloys; particles of metal oxides, carbon, graphite, glass, ceramics, and plastics, etc., whose surfaces are coated with metal; particles whose surfaces are further coated with an insulating film or in which insulating fine particles are attached, etc., are subjected to an insulating treatment. Two or more of these may be mixed. In the case of resin particles whose surfaces are coated with metal, particles of epoxy resin, phenol resin, acrylic resin, acrylonitrile-styrene (AS) resin, benzoguanamine resin, divinylbenzene-based resin, and styrene-based resin, for example, can be used as the resin particles.

The average particle size of the conductive particles is usually 1 to 30 ㎛, preferably 2 to 20 ㎛, and more preferably 2.5 to 15 ㎛. In addition, the average particle density of the conductive particles in the binder resin is preferably 100 to 100,000 pieces/mm2, and more preferably 500 to 80,000 pieces/mm2 from the viewpoints of connection reliability and insulation reliability. For example, the observation results of the film surface obtained by an optical microscope or a metallurgical microscope in a film form can be obtained by image analysis software WinROOF (Mitani Corporation).

In addition, the conductive particles may be dispersed in the insulating resin, and in the case of a film, they may be individually independent when viewed from the film plane, or they may be arbitrarily arranged and exist. When the conductive particles are arranged, the number density and the distance between the conductive particles can be set according to the size or layout of the connected electrode. For this reason, it is effective in improving capture, suppressing short circuits, etc., and cost reduction effects such as improved yields are also expected.

The minimum melting viscosity of the conductive adhesive is preferably 1 to 100,000 ㎩ s, more preferably 10 to 10,000 ㎩ s. The suitability of the minimum melting viscosity also depends on the compression deformation characteristics of the conductive particles, but if the minimum melting viscosity is too high, the binder between the conductive particles and the electrode cannot be sufficiently excluded during thermal compression, so that the connection resistance tends to increase. In particular, for conductive particles having protrusions, it is difficult to sufficiently exclude the binder between the conductive particles and the electrode during thermal compression. On the other hand, if the minimum melting viscosity is too low, the deformation of the conductive adhesive due to the weight during thermal compression becomes large, so that when the pressure is released, the restoring force of the conductive adhesive is applied to the interface of the connection part as a force in the peeling direction. For this reason, the connection resistance tends to increase immediately after thermal compression, or bubbles tend to occur at the connection part.

A conductive adhesive having such a configuration has a moisture permeability measured under the conditions of a temperature of 40° C. and a relative humidity of 90% after curing of preferably 80 g/m2·24 hr or more, more preferably 85 g/m2·24 hr or more, and even more preferably 90 g/m2·24 hr or more. Thereby, moisture that has penetrated into the inside of a device bonded with the conductive adhesive can be instantly discharged, and high reliability in HAST can be obtained. In addition, the moisture permeability can be measured under the conditions of 40° C. and a relative humidity of 90% in accordance with the moisture permeability test method for moisture-proof packaging materials (cup method) of JIS Z 0208.

With this type of challenging adhesive, moisture that has entered the device can be immediately discharged, thereby achieving excellent connection reliability.

＜2. Manufacturing method of connector＞

A method for manufacturing a connector according to the present embodiment comprises a placing step of placing a first electronic component and a second electronic component through an adhesive composition containing silicon particles, a silane coupling agent, a polymerizable compound, and a curing agent, wherein the total surface area of spherical particles calculated from the average particle diameter of the silicon particles is 10 × 10 ³ m2 or more per 100 g of the composition, and a curing step of pressing the second electronic component to the first electronic component using a pressing tool, while curing the adhesive composition. Here, the pressing tool refers to something that applies pressure from the first electronic component or the second electronic component, or both. In addition, the shape or material of the pressing tool is not particularly limited, and as an example, a flat metal tool equipped with a heating mechanism can be exemplified. This may be one used in a known thermal pressing device. In addition, a mechanism that irradiates light may be provided.

In addition, a connecting body related to the present embodiment comprises a first electronic component, a second electronic component, and an adhesive film in which the first electronic component and the second electronic component are adhered, wherein the adhesive film is formed by curing an adhesive composition containing silicone particles, a silane coupling agent, a polymerizable compound, and a curing agent, and wherein the total surface area of spherical particles calculated from the average particle diameter of the silicone particles is 10 × 10 ³ m2 or more per 100 g of the composition, and has a moisture permeability of 80 g/m2·24 hr or more.

The connector related to the present embodiment can instantly discharge moisture that has entered the inside of the device because the adhesive film through which the first electronic component and the second electronic component are adhered has high moisture permeability, and can obtain high reliability in HAST.

Hereinafter, a method for manufacturing a connector using an adhesive film will be described. Fig. 1 is a cross-sectional view schematically showing the arrangement process of a method for manufacturing a connector related to the present embodiment. In addition, since the adhesive composition constituting the adhesive film is the same as that described above, its description is omitted here.

[Batch process (S1)]

As shown in Fig. 1, in the arrangement process (S1), an adhesive film (20) containing silicon particles (21) is arranged on a first electronic component (10). The first electronic component (10) has a first terminal row (11). The first electronic component (10) is not particularly limited and can be appropriately selected depending on the purpose. Examples of the first electronic component (10) include transparent substrates for use in flat panel displays (FPDs) such as LCD (Liquid Crystal Display) panels, organic EL (OLED) panels, touch panels, printed wiring boards (PWBs), flexible substrates (FPCs: Flexible Printed Circuits), etc. The material of the printed wiring board is not particularly limited, and may be, for example, glass epoxy such as FR-4 substrate, plastic such as thermoplastic resin, ceramics, etc. In addition, the transparent substrate is not particularly limited as long as it has high transparency, and examples thereof include glass substrates, plastic substrates, etc. Among these, ceramic substrates are preferably used from the viewpoint of heat resistance.

In addition, it is preferable that the second electronic component facing the first electronic component has a plating bump formed on an IC or a flexible substrate. It is preferable that the plating bump has a low dimple or no dimple, or a flat surface. In addition, it is preferable that the surface of the plating bump is leveled from the viewpoint of increasing the contact area during pressing. In addition, a stud bump may be formed on the wiring substrate.

Since the adhesive film (20) is a film-shaped adhesive composition as described above, a detailed description thereof is omitted here. The thickness of the adhesive film (20) is preferably 1 to 100 µm, and more preferably 10 to 50 µm. This range is the same whether it is a single layer or a multilayer. In addition, in the case of a paste-shaped adhesive, it refers to the thickness when used for connection.

[Hardening process (S2)]

In the curing process (S2), the second electronic component is placed on the adhesive film (20), and the second electronic component is pressed against the first electronic component (10) by a pressing tool, and pressed while applying heat. In addition, in the curing process (S2), the pressing tool is used to press at a temperature of preferably 250° C. or lower, more preferably 220° C. or lower, and even more preferably 200° C. or lower. Thereby, the resin is melted by the heat of the pressing tool, the second electronic component is sufficiently pressed by the pressing tool, and the resin is thermally cured, so that excellent adhesiveness can be obtained. In this case, it is assumed that the pressing tool is equipped with a heating mechanism, but the adhesive film (20) may be heated and cured by a method in which the pressing tool is not equipped with a heating mechanism.

The second electronic component has a second terminal row facing the first terminal row (11). The second electronic component is not particularly limited and can be appropriately selected depending on the purpose. Examples of the second electronic component include an IC (Integrated Circuit), a flexible substrate (FPC: Flexible Printed Circuits), a tape carrier package (TCP) substrate, and the like. When an IC is mounted on an FPC, it becomes a COF (Chip On Film).

In addition, in the curing process (S2), a buffer material may be used between the pressing tool and the second electronic component. As the buffer material, polytetrafluoroethylene (PTFE), polyimide, glass cloth, silicone rubber, etc. can be used.

According to the manufacturing method of such a connector, since the adhesive film that bonds the first electronic component and the second electronic component has high moisture permeability, moisture that has entered the inside of the device can be discharged immediately, and high reliability can be obtained in HAST.

[Variation]

In addition, in the above-described embodiment, the first electronic component and the second electronic component are connected using an adhesive film, but the present invention is not limited thereto, and the first electronic component and the second electronic component may be connected using a conductive adhesive film containing conductive particles. In addition, the conductive adhesive film may have a two-layer configuration consisting of a layer containing conductive particles (for convenience, referred to as a conductive particle-containing layer) and a layer not containing conductive particles (for convenience, referred to as a conductive particle-free layer). In addition, even in the case of a paste form, the same configuration can be taken at the time of connection.

＜3. Example＞

Example

Hereinafter, examples of the present technology will be described. In the first example, an adhesive film was produced as one form of an adhesive composition, and a connecting body was produced. Then, the moisture permeability of the adhesive film after curing, the initial adhesive strength of the connecting body, the adhesive strength after a reliability test, and the initial electrical resistance of the connecting body and the electrical resistance after a reliability test were measured.

[Production of adhesive film and measurement of moisture permeability]

The materials shown in Table 1 were mixed to produce an adhesive film having a thickness of 35 ㎛. In addition, in order to measure the moisture permeability, the adhesive film was cured at a temperature of 200°C to produce a sample film. The moisture permeability was measured under the conditions of 40°C and a relative humidity of 90% in accordance with the moisture permeability test method for moisture-proof packaging materials (cup method) of JIS Z 0208. Specifically, calcium chloride (anhydrous) was sealed in a cup, the cup covered with the sample film was placed still in a constant temperature and humidity state, and the weighing operation was repeated at regular intervals, and the mass increase of the cup was evaluated as the amount of water vapor permeability.

[Creating a connector]

A bare chip (IC chip) with a thickness of 0.4 mm, a width of 6 mm, and a length of 6 mm (6 mm × 6 mm) was used, and a measurement TEG (Test Element Group) was used on which a wiring for conductivity measurement (bump size: 50 × 50 ㎛, pitch: 85 ㎛ (space between bumps: 35 ㎛), gold bump height h = 15 ㎛) was formed. The gold bumps were plated bumps, and smooth ones without dimples were used.

A measurement TEG was used to form a flexible printed circuit (FPC) for conducting measurement with a polyimide substrate, a thickness of 25 ㎛, a pitch of 85 ㎛ (L/S = 45/40), and a top of 40 ㎛.

A bare chip was mounted on a flexible wiring board using an adhesive film. The thermal compression conditions were a temperature of 200°C, a pressure of 100 MPa, and 10 sec. In addition, a polytetrafluoroethylene sheet having a thickness of 50 μm was placed on the bare chip as a cushioning material during the thermal compression.

[Measurement of adhesive strength]

The flexible wiring board of the joint was peeled in the 90° direction at a tensile speed of 50 mm/sec, and the maximum peel strength required for the peeling was taken as the bonding strength. The measurement was made for the initial joint and the joint after the reliability test. The reliability test was conducted under the conditions of temperature 110°C, humidity 85%, and time 264 hr in accordance with JEDEC (JESD22-A110).

[Measurement of the resistance of the conductor]

Regarding the connection status of the bare chip and the flexible wiring board, the conduction resistance (Ω) at the initial connection and after the reliability test was measured using a digital multimeter. To measure the conduction resistance, the digital multimeter was connected to the wiring of the flexible wiring board connected to the bump of the bare chip, and the conduction resistance was measured by flowing 1 mA of current using the 4-terminal method. The reliability test was conducted under the conditions of a temperature of 110°C, a humidity of 85%, and a time of 264 hr in accordance with JEDEC (JESD22-A110).

Polymer: YP-50 (Nittetsu Sumitomo Chemical Co., Ltd.)

Epoxy hardener: HP3941 (Asahi Kasei Chemicals Co., Ltd.)

Epoxy compound: HP4032D (DIC Co., Ltd.)

Rubber particles: XER-91 (JSR Co., Ltd.)

Rubber component: SG80H (Nagase Chemtex Co., Ltd.)

Coupling agent: A-187 (Momentive Performance Materials Japan (compound))

Silicone particle A: X-52-7030 (Shin-Etsu Silicone Co., Ltd.), average particle size 0.8 ㎛, true specific gravity 1.01

Silicon particle B: KMP-605 (Shin-Etsu Silicone Co., Ltd.)), average particle size 2 ㎛, true specific gravity 0.99

Silicon particle C: KMP-600 (Shin-Etsu Silicone Co., Ltd.)), average particle size 5 ㎛, true specific gravity 0.99

In addition, the specific surface area of the silicon particles was obtained from the surface area per particle calculated from the average particle diameter and the mass per particle calculated from the average particle diameter and true specific gravity.

As shown in Table 1, since the sum of the surface areas of the spherical particles calculated from the average particle diameter of the silicone particles was 10 × 10 ³ m2 or more per 100 g of the composition (Examples 1 to 8), a moisture permeability of 80 g/m2·24 hr or more could be obtained. Furthermore, since the sum of the surface areas of the spherical particles calculated from the average particle diameter of the silicone particles was 50 × 10 ³ m2 or more per 100 g of the composition (Examples 5 to 7), a moisture permeability of 90 g/m2·24 hr or more could be obtained. When the silicone particles were not mixed, the moisture permeability was 75 g/m2·24 hr (Comparative Example 1).

[Example 2]

In the second embodiment, a conductive film was produced as one form of an adhesive composition, and a connector was produced. Then, the moisture permeability of the conductive film after curing, the initial adhesive strength of the connector, the adhesive strength after a reliability test, and the initial electrical resistance of the connector and the electrical resistance after a reliability test were measured.

[Production of challenge film and measurement of moisture permeability]

A conductive film having a thickness of 35 ㎛ was produced by mixing the materials shown in Table 1. In addition, in order to measure the moisture permeability, the conductive film was cured at a temperature of 200°C to produce a sample film. The moisture permeability was measured under the conditions of 40°C and a relative humidity of 90% in accordance with the moisture permeability test method for moisture-proof packaging materials (cup method) of JIS Z 0208. Specifically, calcium chloride (anhydrous) was sealed in a cup, the cup covered with the sample film was left to stand in a constant temperature and humidity state, and the weighing operation was repeated at regular intervals, and the mass increase of the cup was evaluated as the amount of water vapor permeability.

[Creating a connector]

A bare chip (IC chip) with a thickness of 0.4 mm, a width of 6 mm, and a length of 6 mm (6 mm × 6 mm) was used, and a measurement TEG (Test Element Group) was used on which a wiring for conductivity measurement (bump size: 50 × 50 ㎛, pitch: 85 ㎛ (space between bumps: 35 ㎛), gold bump height h = 15 ㎛) was formed. The gold bumps were plated bumps, and smooth ones without dimples were used.

A bare chip was mounted on a flexible wiring board using a conductive film. The thermal compression conditions were a temperature of 200°C, a pressure of 100 MPa, and 10 sec. In addition, during the thermal compression, a silicone rubber having a thickness of 200 μm was placed on the bare chip as a cushioning material.

[Measurement of adhesive strength]

The flexible wiring board of the joint was peeled in the 90° direction at a tensile speed of 50 mm/sec, and the maximum peel strength required for the peeling was taken as the bonding strength. The measurement was made for the initial joint and the joint after the reliability test. The reliability test was conducted under the conditions of temperature 110°C, humidity 85%, and time 264 hr in accordance with JEDEC (JESD22-A110).

[Measurement of the resistance of the conductor]

Regarding the connection status of the bare chip and the flexible wiring board, the conduction resistance (Ω) at the initial connection and after the reliability test was measured using a digital multimeter. To measure the conduction resistance, the digital multimeter was connected to the wiring of the flexible wiring board connected to the bump of the bare chip, and the conduction resistance was measured by flowing 1 mA of current using the 4-terminal method. The reliability test was conducted under the conditions of a temperature of 110°C, a humidity of 85%, and a time of 264 hr in accordance with JEDEC (JESD22-A110).

Polymer: YP-50 (Nittetsu Sumitomo Chemical Co., Ltd.)

Epoxy hardener: HP3941 (Asahi Kasei Chemicals Co., Ltd.)

Epoxy compound: HP4032D (DIC Co., Ltd.)

Rubber particles: XER-91 (JSR Co., Ltd.)

Rubber component: SG80H (Nagase Chemtex Co., Ltd.)

Coupling agent: A-187 (Momentive Performance Materials Japan (compound))

Challenge particle A: Ni/Au plated acrylic resin particles, average particle size 5 ㎛, Nippon Chemical Co., Ltd.

Challenge particle B: Ni/Au plated acrylic resin particles, average particle size 3.5 μm, Nippon Chemical Co., Ltd.

Challenge particle C: Ni/Au plated acrylic resin particles, average particle size 3 ㎛, Nippon Chemical Co., Ltd.

Silicone particle A: X-52-7030 (Shin-Etsu Silicone Co., Ltd.), average particle size 0.8 ㎛, true specific gravity 1.01

Silicon particle B: KMP-605 (Shin-Etsu Silicone Co., Ltd.)), average particle size 2 ㎛, true specific gravity 0.99

Silicon particle C: KMP-600 (Shin-Etsu Silicone Co., Ltd.)), average particle size 5 ㎛, true specific gravity 0.99

In addition, the specific surface area of the silicon particles was obtained from the surface area per particle calculated from the average particle diameter and the mass per particle calculated from the average particle diameter and true specific gravity.

As shown in Table 2, when the average particle diameter of the silicone particles was smaller than the average particle diameter of the conductive particles, and the sum of the surface areas of the spherical particles calculated from the average particle diameter of the silicone particles was 10 × 10 ³ m2 or more per 100 g of the composition (Examples 9 to 17), a moisture permeability of 80 g/m2·24 hr or more could be obtained. In addition, when the sum of the surface areas of the spherical particles calculated from the average particle diameter of the silicone particles was 50 × 10 ³ m2 or more per 100 g (Examples 13 to 15), a moisture permeability of 90 g/m2·24 hr or more could be obtained. When the silicone particles were not mixed, the moisture permeability was 75 g/m2·24 hr (Comparative Example 2). In addition, when the average particle diameter of the silicone particles was equal to or larger than the average particle diameter of the conductive particles, the resistance value increased (Comparative Examples 3 and 4).

By setting the moisture permeability of the conductive film to 80 g/㎡·24 hr or more as in Examples 9 to 17, it was possible to suppress the increase in resistance after the reliability test. This is thought to be because the high moisture permeability of the conductive film enabled moisture that had entered the inside of the device to be immediately discharged.

10; 1st electronic component
11; 1st terminal row
20 ; Adhesive film
21; Silicon particles

Claims (14)

Containing silicone particles, a silane coupling agent, a polymerizable compound, a curing agent, and two or more types of rubber components excluding the silicone particles,
The sum of the surface areas of the spherical particles calculated from the average particle diameter of the above silicone particles is 10 × 10 ³ m2 or more per 100 g of the composition,
The above rubber component comprises acrylic rubber and elastic particles,
The amount of the above rubber component is 1 to 30 parts by mass per 100 parts by mass of the adhesive composition.
An adhesive composition having a moisture permeability of 80 g/㎡·24 hr or more as measured under conditions of a temperature of 40°C and a relative humidity of 90% after curing of the composition. delete delete In paragraph 1,
An adhesive composition wherein the sum of the surface areas of spherical particles calculated from the average particle diameter of the above silicone particles is 50 × 10 ³ m2 or more per 100 g of the composition. In paragraph 1,
An adhesive composition wherein the average particle diameter of the silicone particles is 5 ㎛ or less. In paragraph 1,
An adhesive composition comprising a silicone composite powder, wherein the silicone particles are spherical powders in which the surface of a spherical silicone rubber powder is covered with silicone resin. In paragraph 1,
The above polymerizable compound is an epoxy compound,
The above hardener is an epoxy hardener,
An adhesive composition wherein the above silane coupling agent is an epoxy-based silane coupling agent. delete In paragraph 1,
Contains additional challenging particles,
An adhesive composition wherein the average particle diameter of the silicone particles is smaller than the average particle diameter of the conductive particles. In any one of paragraphs 1, 4 to 7 and 9,
Film-forming adhesive composition. Containing silicone particles, a silane coupling agent, a polymerizable compound, a curing agent, and two or more types of rubber components excluding the silicone particles,
The above rubber component comprises acrylic rubber and elastic particles,
The amount of the above rubber component is 1 to 30 parts by mass per 100 parts by mass of the adhesive composition.
The sum of the surface areas of the spherical particles calculated from the average particle diameter of the above silicone particles is 10 × 10 ³ m2 or more per 100 g of the composition,
A placement process for placing a first electronic component and a second electronic component by interposing an adhesive composition having a moisture permeability of 80 g/㎡·24 hr or more as measured under conditions of a temperature of 40°C and a relative humidity of 90% after curing of the composition;
A curing process for curing the adhesive composition while pressing the second electronic component onto the first electronic component by a pressing tool.
A method for manufacturing a connection body having a . In Article 11,
A method for producing a connector, wherein the adhesive composition further contains conductive particles. It comprises a first electronic component, a second electronic component, and an adhesive film to which the first electronic component and the second electronic component are adhered,
A connector formed by curing an adhesive composition in which the adhesive film contains silicone particles, a silane coupling agent, a polymerizable compound, a curing agent, and two or more kinds of rubber components excluding the silicone particles, wherein the rubber components include acrylic rubber and elastic particles, the blending amount of the rubber component is 1 to 30 parts by mass with respect to 100 parts by mass of the adhesive composition, the sum of surface areas of spherical particles calculated from the average particle diameter of the silicone particles is 10 × 10 ³ m2 or more per 100 g of the composition, and the moisture permeability measured under conditions of a temperature of 40° C. and a relative humidity of 90% after curing of the composition is 80 g/m2·24 hr or more. In Article 13,
A connector wherein the adhesive composition further contains conductive particles.