TW201134916A - Anisotropic conductive adhesive - Google Patents

Abstract

An anisotropic conductive adhesive is a material which comprises a highly insulating adhesive and electroconductive particles uniformly dispersed therein, and such a material is used in electronic components for the purpose of electrical connection between electrodes that face with each other, insulation between adjacent electrodes, or fixing. Conventional anisotropic conductive adhesives exhibited low durability in terms of creep test, and it was therefore difficult for conventional anisotropic conductive adhesives to attain stable circuit resistance. Disclosed is a non-reactive anisotropic conductive adhesive which comprises (A) a polyamide elastomer, (B) a powder composed of spherical electroconductive particles, and (C) a solvent and which exhibits excellent creep characteristics and conducting properties.

Description

201134916 VI. Description of the Invention: TECHNICAL FIELD OF THE INVENTION The present invention relates to an anisotropic conductive adhesive. [Prior Art] An anisotropic conductive adhesive (hereinafter, also referred to as ACP) is a material which uniformly disperses conductive particles in an adhesive having high insulating properties, and is used for electrical connection between opposing electrodes of an electronic component, adjacent electrodes Insulation and fixing purposes. When a solvent-containing ACP is printed on a flexible printed circuit board (hereinafter referred to as FPC) and dried by heating, the ACP coating film can be formed on the FPC. FPC containing a coating film is known as a heat seal connector member (Japanese Laid-Open Patent Publication No. Hei. After the electrode portion of the display element and the electrode portion of the retort connecting portion member are aligned, the electrodes are selectively connected by heating in a near-line manner. Further, an electronic component in which an FPC state in which an ACP coating film has been formed is transported, and two types of members are connected by ACP, and durability is confirmed by a reliability test. As a test item, a latent test in which a load is applied in a heated state as a method of confirming adhesion, a resistance 値 as a measuring circuit for confirming an electrical connection method, and an initial resistance 値 and a high temperature placement test or thermal cycle are known. The resistance 后 after the reliability test such as the test is compared to confirm the stability of the conduction. As a constituent component of the ACP, a varnish in which a rubber is dissolved in a solvent is used as an adhesive (Japanese Laid-Open Patent Publication No. Hei 5-247424). 201134916 Other non-reactive types such as elastomers and thermoplastic resins are used. However, the solvent is volatilized to form a coating film, and since it is a hot-melt type adhesive, the adhesion of the reactive adhesive is low even if the heating is applied. Even if the initial adhesion is exhibited, the reliability test cannot be passed. The test piece for the peeling test was placed at a temperature of 85 ° C in a state in which the load was applied in a peeling direction. The heat-melt type was softened during the placement and was peeled off by the body. Further, for the purpose of improving reliability, a solvent-free type/reactive type ACP is known. There is an ACP using an epoxy resin (Attachment No. 8-51 1 570) or an ACP using an urethane resin (Japanese Laid-Open Patent Publication No. SHO 61-47760). Recently, since polyethylene terephthalate (PET) or the like has been used in FPC, the heat-resistant temperature of the object has been lowered. Therefore, in addition to the difficulty of continuous heating until the temperature at which the reaction begins, if the low-degradability is caused to cause the guidance, the bundle should be counter-protected. [Inventive content] The purpose of the invention is to invent the past ACP for creep The durability of the test is low, making it difficult to stabilize the circuit. SUMMARY OF THE INVENTION The results of the repeated review by the team of the invention for the above-mentioned purposes revealed the reliability of the ACP by using polyamine elastomer as an adhesive.

The improvement of S -6-201134916 is excellent, and the present invention has been completed. The first aspect of the present invention is an anisotropic conductive adhesive composed of the following components (A) to (C): (A) component: polyamine elastomer (B) component: spherical conductive powder (C) Component: Solvent The second aspect of the present invention is the anisotropic conductive adhesive as described above, wherein the component (A) has two or more carboxyl groups in one molecule synthesized by polymerization of an unsaturated fatty acid. The compound is composed of a polyamidamine elastomer synthesized as a raw material. The third aspect of the present invention is the anisotropic conductive adhesive according to the above aspect, wherein the component (A) has a melting point of from 90 ° C to 140 ° C. The fourth aspect of the present invention is the anisotropic conductive adhesive as described above, wherein the component (B) is a conductive metal plating powder having organic particles as a core. According to a fifth aspect of the present invention, in the anisotropic conductive adhesive described above, the amount of the component (B) is from 1 to 100 parts by mass based on 1 part by mass of the component (A); 100 parts by mass of the component, and the amount of the component (C) is 1 to 100 parts by mass. According to a sixth aspect of the invention, there is provided a flexible printed circuit board member which is obtained by screen printing or applying an anisotropic conductive adhesive described above to a flexible printed circuit board, and then volatilizing the component (C). EFFECT OF THE INVENTION 201134916 By the present invention, a non-reactive ACP having excellent creep properties and conductivity can be obtained. BEST MODE FOR CARRYING OUT THE INVENTION The details of the present invention are as follows. As the component (A) which can be used in the present invention, it is a polyamine elastomer having a guanamine bond. Particularly, a polyamine elastomer which has a branched chain and a compound having two or more carboxyl groups in one molecule synthesized by radical polymerization of an unsaturated carboxylic acid is used as a raw material. The synthesis method of the compound having two or more carboxyl groups in one molecule is, for example, the general formula 1, but is not limited thereto. Generally, nylon is widely known as a polyamide resin, and it is generally synthesized by a polycondensation reaction or a condensation reaction between a saturated aliphatic diamine and a saturated aliphatic dicarboxylic acid. Since nylon is a linear resin having no branching, it is different from the component (A).

CH3-R1-CH2-CH = CH-CH2-R1-CH2-COOH (A)

CH3-R1-CH=CH-CH = CH-R1-CH2-COOH (B) 1 (1) R2

CH3-R1-CH2-CH-(:H-CH2-R1-CH2-COOH CHa-R^CH-Ct^CH-CH-R1 -CH2-COOH

h (O where R1 is a divalent hydroxyl group, which may be the same or different, respectively. R2 -8 -

S 201134916 is the organic residue of the polymerization initiator. R1 is preferably a C 1-6 aliphatic hydroxy group, particularly a linear aliphatic hydroxy group. As described above, the component (A) is preferably a compound having a branched chain and having two or more carboxyl groups in one molecule synthesized by radical polymerization of an unsaturated carboxylic acid, and bonding the polyamine elastomer. A polyamine elastomer having a guanamine bond of the above compound. This bonding can usually be carried out by reacting the above carboxyl group with an amine group of a polyamide elastomer. Further, in order to make the component (A) resistant to the reliability test for heating, the melting point is preferably 80 ° C or higher, and particularly preferably 90 ° C or higher. Further, since the component (A) is melted at the time of heating and pressing, and the heat resistance of the object to be treated is considered, the melting point of the component (A) is particularly preferably 140 °C or lower. Among the elastomers, there is also a type in which the melting point cannot be confirmed. In the atmosphere of room temperature or higher, it is softened as long as the temperature rises, and it is not suitable for the present inventors. The method of confirming the melting point may, for example, be a differential scanning calorimeter (DSC) or a TG/DTA (differential heat balance), but is not limited thereto. As the component (A) of the present invention, a block copolymer or the like of a polyamine or a polyester such as a polyester may be used, and an amine group or a carboxyl group may be left as a functional group. Alternatively, two or more components (a) may be mixed. Specific examples of the component (A) include, for example, TORMID PA series and TPAE system 歹IJ manufactured by Fuji Chemical Co., Ltd., but are not limited thereto. As the component (B) which can be used in the present invention, spherical conductive particles can be used. The so-called spherical shape also includes true round particles or spherical particles having irregularities on the surface. The material may be metal powder such as gold, silver, platinum, nickel, -9-201134916 palladium or plated particles coated with a metal film on the surface of the organic polymer particles. In the present invention, it is preferred to use an electrically conductive metal plater having soft organic polymer particles as a core. Further, it is known that the particles are used in accordance with the line width between the electrodes of the connection substrate or the thickness of the electrode. When the line width is narrow, it is preferable to use the component (B) having a small average particle diameter. In terms of the average particle diameter, it is preferably from 1 to 50 μm, and the particle size distribution is particularly excellent. The amount of the (Β) component to be added is preferably from 1 to 100 parts by mass based on 100 parts by mass of the (Α) component. When the amount is more than 100 parts by mass, the insulation property between the electrodes may not be sufficiently ensured due to too much (Β) component, and if it is 1 part by mass or less, stable conductivity may not be obtained. The (Β) component varies depending on the average particle diameter of the particle size distribution, the core material of the plating powder, or the metal content of the plating component. Therefore, the amount of the (Β) component added has a range. The component (C) which can be used in the present invention can be used as long as it can dissolve the (Α) component. Specific examples thereof include, but are not limited to, methanol, methyl ethyl ketone, toluene, xylene, isophorone, ethyl acetate, benzyl alcohol, and the like. Further, the component (C) may be added to adjust the viscosity or viscosity. When the amount of addition is large, the viscosity becomes low and the viscosity becomes low. Also, when the amount of addition is small, the viscosity is high and the viscosity is maintained at a high state. The amount of the component (C) to be added is preferably 1 to 1000 parts by mass based on the (C) component, and more preferably 50 to 9000 parts by mass of the component (C). When the component (C) is 900 parts by mass or more and 201134916, the viscosity of the adhesive is excessively lowered, and the precipitation of the conductive particles is severe. When the content is 50 parts by mass or less, it is difficult to have an excessively high viscosity. The operation of the ACP of the present invention can be carried out by using a dispensing method. In addition to being a certain coating film, it is particularly suitable for screen printing due to solvent evaporation. Further, the ACP having the electrode is applied to a hot air drying oven or a belt conveyor type IR furnace to be volatilized. The coating film of the ACP is formed by drying it. After being aligned with the one side of the object, the adhesive is dissolved by heating and pressing, and the conductive particles are pushed to the electrode connection of both sides, and mechanically returned to the room temperature state. fixed. As a target for forming a coating film, FPC or the like produced from a polyamide resin, a diethylene glycol diester resin or the like can be exemplified. There is also a case where the FPC of the membrane is transported, and after a certain period of time, it is combined with the base. Therefore, the coating film must be at room temperature to have a melting point or a softening point of the component (A) above room temperature. As long as the characteristics of the present invention are not impaired, it is also possible to add a resin such as an elastomer such as an elastomer, a rubber or a thermoplastic resin to an urethane rubber or a polychlorosulfonated rubber to which a thermoplastic elastomer can be added. Chloroprene rubber, chlorinated polyethylene, propylene, fluororubber, ethylene-vinyl acetate, and the like. By adding such a resin film, the adhesive strength, the workability, the preservability, and the like, and the coating film excellent after drying. In addition, 'as long as the range of characteristics of the present invention is not impaired', the operability or screen printing will be uniformly applied, and the other components of the solvent electrode will be ensured to ensure electric or poly-p-benzene. Forming a coating plate heating compact, preferably 丨 (A) component, specific oxygen rubber, olefinic rubber, can obtain a composition, an appropriate amount of -11 - 201134916 pigments, dyes and other colorants; metal powder, calcium carbonate, talc, dioxide Inorganic filling agent such as barium, alumina, aluminum hydroxide; additives such as flame retardant, organic filling agent, plasticizer 'antioxidant, defoaming agent, coupling agent, leveling agent, rheology control agent. By adding this, it is possible to obtain a composition excellent in resin strength, adhesion strength, workability, and preservability, and a cured product thereof. Further, by adjusting the conductive particle diameter or the binder solid content, a composition that can correspond to an electrode circuit having various pitches and a coating film thereof can be obtained. [Embodiment] Next, an exemplary embodiment will be The present invention has been described in more detail, but the present invention is not limited to the embodiments. Examples 1 to 6 The following components were prepared for the preparation of the anisotropic conductive adhesive. The results of the melting points measured by TG/DTA of the components (A) and (A') are shown in Table 1. (A) Ingredients: Polyamide elastic (satisfying the general formula 1) • Polyamide elastic (100% solid content) (TPAE-32 Fuji Chemical Industry Co., Ltd.) • Polyamide elastomer (solid fraction 1) 〇〇%) (TPAE-31 Fuji Chemical Industry Co., Ltd.) -12- 201134916 • Polyamide elastomer (solid content: 1%) (PA-2 01 Fuji Chemical Co., Ltd.) • Polyamide Elastomer (solid content: 100%) (ΡΑ-2〇0 Fuji Chemical Co., Ltd.) (B) Component: spherical conductive powder • spherical plating powder with an average particle size of 30 μm (Bright 6GNR30-BHB (Nippon Chemical Industry Co., Ltd.) (C) Ingredients: Solvents • Industrial toluene (toluene Japan Alcohol Trading Co., Ltd.) • Industrial Methanol (Methanol Mitsubishi Gas Chemical Co., Ltd.) Other Ingredients: Filling Agent • Talc powder (manufactured by MICRO ACE P-2 Japan Talc Co., Ltd.) • Amorphous vermiculite (AEROSIL R972, manufactured by AEROSIL Co., Ltd.) Comparative Example 1 - 7 In order to prepare an anisotropic conductive adhesive, the following preparations were prepared. ingredient. The ingredients other than the (A') component were used in the same manner as in the examples. (A') component: Elastomer other than (A)-13 - 201134916 • Polyurethane elastomer (solid content 100%) (Pandex T-5 2 02 Dainippon Ink Industry Co., Ltd. • Polyurethane B Ester Elastomer (solid content 1%%) (Pandex T-5210 Dainippon Ink Industry Co., Ltd. • Polyurethane Elastomer (solid content 1%%) (Miractran P22SRNAT) • Polyester Elastomer (Solid Form) 60%) (Nichigo polyester TP-290 manufactured by Nippon Synthetic Chemical Co., Ltd.) • Polyester elastomer (60% solids) (Nichigo polyester TP-293, manufactured by Nippon Synthetic Chemical Co., Ltd.) SEBS rubber elastic (solid content 1〇〇) %) (Kraton FG1901X Kraton Polymer Japan Co., Ltd.) (C) Ingredients: Solvents and industrial isophorone (isophorone, Godo Solvent Co., Ltd.) (manufactured by the company) Industrial Stock Co., Ltd.) -14 - 201134916 Table 1 (A) component or (A') component melting point (°C) TPAE—32 124 TPAE-31 118 PA-201 122 PA-200 85 T-5202 43 T-5210 38 P22SRNAT Μ jw\ TP-290 Μ. Ji\\ TP-293 31 FG1901X No [melting point determination method] A melting point in TG / DTA measurement of conditions as follows. A sample of 1 mg to 1 mg was placed in an aluminum cup and measured at a temperature rise rate of 1 〇 t:/min under a nitrogen atmosphere at a temperature range of -40 t to 15 (TC) to indicate the difference in heat (DTA). The temperature at which the temperature is reduced or the point at which the differential heat of differential heat (DDTA) is reduced is referred to as the "melting point ()". If the melting point cannot be confirmed, for example, when the change in DTA or DDTA is slow, the change point cannot be clearly known. The device is: "None." Device manufacturer: Seiko Instruments Inc. Device: EXSTAR6000 TG/DTA6200 Ming Cup: Open Sample Pan φ 5 The manufacturing methods of Examples 1 to 6 and Comparative Examples 1 to 7 are as follows. In the container of the component (C), the component (A) or (A) is added to the container in a little bit at -15 to 201134916. After the total amount of the component (A) or the component (A') is added, Stir for 3 hours. If the (A) component has dissolved residue, extend the stirring time until the mixture is stirred until no residue remains. Stir while heating. Then add the additive of (B) and other ingredients. After stirring for 1 hour, the passage through the gap has been adjusted to 4 0 Pm three-axis roller mill 2 times. The detailed modulation amount is expressed in parts by mass according to Table 2'.

Table 2 Raw material name Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 TPAE-32 100 50 (A TP TPAE-31 100 50 PA-201 50 50 100 PA-200 100 T-6202 T -5210 (A,) component P22RNAT TP-209 TP-293 i=G19〇1X (B) component 6GNR30-BHB 10 10 10 10 10 10 toluene 300 300 300 300 300 300 (C 甲醇 methanol 100 YOO ICO 100 100 too Isophorone Other Ingredients MICRO ACE P-2 30 30 30 30 30 30 R972 5 5 5 5 5 5 Total 545 545 545 545 545 545 Material Name Comparison Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Comparative Example 7 TPAE-32 (A) component TPAE-31 PA-201 PA-200 T-5202 100 T-52TO 100 50 (A') component P22RNAT 100 TP-209 100 200 TP-293 200 FG1901X 100 (B)k Substituting 66NR30-QHB 10 10 10 10 10 Fly 0 10 Toluene (C 戚 methanol isophorone 400 400 350 400 300 300 400 Other ingredients MICRO ACE P-2 30 30 30 30 30 30 30 R972 5 5 5 5 5 5 5 Total 545 545 545 545 545 545 545 -16- 201134916 For the anisotropic conductive adhesives of Examples 1 to 6 and Comparative Examples i to 7, a test piece was prepared according to the test piece production method, and a peel strength test was performed. The creep test and the conductivity test are shown in Table 3. [Test piece production method (screen printing, drying, heating and pressing)] The FPC was used to screen the anisotropic conductive adhesive under the following conditions. Hole size: SUS mesh # 8 0 Printing speed · · 4 0 mm / sec Printing pressure: 0.2 MPa Put a PET film or FPC printed with an anisotropic conductive adhesive into a hot air drying oven at 120 °C x10 minutes The drying causes the component (C) to volatilize to form a uniform composition coating film on the surface of the PET film or FPC. After the PET film or the FPC on which the coating film was formed was adjusted to the position of the substrate, the test piece prepared for the peel strength test, the creep test, and the conductivity test was subjected to heat pressing under the following conditions to carry out adhesion. When the test piece is produced, it is carried out under the most suitable setting conditions. Heating head contact area: 3mmx60mm Heating condition: 1 10~160°C Pressurization condition: 3~5 MPa Heating pressing time: 1 〇~30 sec [Peel strength test] Printing and drying on PET film 'as in Figure 1 The test piece was prepared by pressing -17-201134916 on ITO glass. The size of the adhesive is 3mm x l0mm. After the placement for 30 minutes, the peel strength test was performed. The tensile peel strength of the PET film was measured at a test speed of 50 mm/min at an angle of 90 degrees with respect to the ITO glass. Four test pieces were measured. The average strength ( and width (10 mm) of the maximum strength (N) were calculated as "peel strength (N/m)". The specifications of PET film and ITO glass are as follows. PET film: 10mm wide, 38μιη thick ITO glass: refers to the glass with the vapor deposited film. 60 mm x 25 mm x 1.1 mm area resistance 1 〇 Ω / □ (The following ITO glass is the same specification) "Peel strength (N/m)" is evaluated as follows. The results are shown in Table 2. 〇: 800 N/m or more △ : 400 to 800 N/m X : less than 400 N/m [latent creep test] The same PET film and ITO glass as the peel strength test were used for heating and pressing as in Fig. 2 sheet. After placing for 3 minutes, 'exfoliate the excess adhesive to 3mmx50mm, apply the load in the weight direction of 3 gf/mm (width) in Figure 5, and place the test piece at 85 °C. in. At the same time, five test pieces were placed and the measurement was carried out until all the test pieces were peeled off due to the load, and the "potential characteristics" were evaluated by the following criteria. The results are shown in Table 2. -18- 201134916 〇: Full peeling of 24 hours or more △ : 12-24 time full peeling X : 1 2 time full peeling [conductivity confirmation] The following FPC and peel strength test and creep test are performed using ITO glass of the same specification Continuity confirmation. As shown in Fig. 3, the end of the conductive coating was heated and pressed by a distance of 7 mm from the end of the FPC pressing portion. After standing for 30 minutes, the test piece was placed in a thermal cycle tester, and the cycle was repeated for -100 hours at -40 ° C for 30 minutes + 85 ° C for 30 minutes. After the end of the test, the sample was taken out for 30 minutes, and the test electrode was touched on the coating film of Fig. 3: the coating film of silver paste and the electrode of 9: FPC, and the resistance was measured. The average resistance 5 of the 50 wires is regarded as "conductivity (Ω)". FPC material: Polyimine FPC Thickness: 25μιη Wire: Gold wire shovel treated to a thickness of 35μιη copper wire spacing: 0.4mm (L / S = 0.2mm / 0.2mm) Number of wires: 50 pieces of silver paste · · ThreeBond 3350C (room temperature drying type) The evaluation of "conductivity (Ω)" is given by the following criteria. 〇: The average 値 is less than 1 5 Ω △: The average 値1 5~20 Ω -19- 201134916 X : The average 値 20 Ω or more [Comprehensive evaluation] The peel strength test, the creep test, and the continuity test are based on the following points. The results are collectively referred to as "comprehensive evaluation." 〇: 2 points △ : 1 point X : 〇

Test item unit Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Peel strength N/m 〇0 〇0 〇] Δ Latent characteristic - △ △ 〇〇0 厶 Conductivity Ω 〇0 〇〇 〇Δ total evaluation - 5 5 6 6 6 3 Test item unit Comparative example 1 Comparative example 2 Comparative example 3 Comparative example 4 Comparative example 5 Comparative example 6 Comparative example 7 Peel strength H/m 0 〇Δ 〇Δ 〇0 creep Characteristics - XXXXXXX Conductivity Ω 厶 Δ X Δ △ 厶 Δ Total evaluation 1 3 3 1 3 2 3 3 When the examples were compared with the comparative examples, the comparative examples 1 to 7 did not simultaneously maintain the creep characteristics and conductance. The composition of properties; however, in the examples, the peel strength can be maintained while coexisting the latent property and the conductivity. Further, from Table 1, the melting point of the component (A) of Example 6 is 85 ° C, because it is the same as the atmospheric temperature of 85 ° C in the creep test, even if compared with Examples 1 to 5, there are several characteristics. It is inferior, but it still maintains the minimum peel strength, creep properties, and conductivity. The (A') component used in the comparative example was tested using a polyester elastomer, an urethane elastomer, or a rubber elastomer which was widely used in the ACP field, but the characteristics could not be maintained in all the test items; ( -20 - 201134916 A) Polyamide elastomers are particularly excellent in maintaining the properties as ACP. Further, the FPC in which the ACP coating film formed by screen printing or the like is transported in many cases, and the stability of the coating film must be maintained. Therefore, in the case of the component (A) having a clear melting point, the ACP coating film is stable. Industrial Applicability For the non-reactive ACP, it is very difficult to maintain the latent property of 85 °C; however, the ACP of the present invention exhibits stability characteristics while maintaining the latent characteristics. After printing a large amount of ACP into FPC, a large amount of drying is carried out in a batch furnace, and the invention can be mass-produced by heating for a short period of time, while maintaining the characteristics close to the reactive ACP grade. It can also be used for applications other than the current non-reactive ACP. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is an explanatory view showing a method of measuring a peel strength test. Fig. 2 is an explanatory view showing a method of measuring a creep test. Fig. 3 is an explanatory view showing a method of measuring a continuity test. [Main component symbol description] 1 : PET film 2 : IT 0 glass 3 : Adhesive part -21 - 201134916 4 : Peeling direction 5 : Load direction

6 : FPC 7: Conductive surface of ITO glass 8 : Coating of silver enamel 9 : Electrode of F P C

Claims (1)

201134916 VII. Application for Patent Park: 1. An anisotropic conductive adhesive consisting of 1 (c) components: (A) Component: Polyamide elastic (B) Component: spherical conductive powder Body (C) component: solvent. 2. The anisotropic conductive adhesive layer (A) according to the first aspect of the patent application is composed of a compound having two or more carboxyl groups in the polymerization of an unsaturated fatty acid as a raw material, a mercapto elastomer. 3. The melting point of the anisotropic conductive adhesive (A) as in the first paragraph of the patent application is 90 ° C to 140 ° C. 4. The application of the first aspect of the patent range of the anisotropic conductive adhesive ' (B) is a conductive gold core with organic particles as the core. 5. The anisotropic conductive viscosity of the first paragraph of the patent application' ( The amount of the component B) is 1 part by mass based on the (a) component 1 and the amount of the component (C) is 1 to 100 parts by mass based on the component (A). 6. A flexible printed circuit board member characterized in that the anisotropic conductive adhesive of the first item is volatilized by screen printing or coating. Said (A) agent, which should be synthesized in the synthesis of the polymerization agent, wherein the agent, wherein I plating powder. Ingredients, where the amount is 1 to 100 masses. After applying for a patent, make (-23-