TW201012894A - Anisotropic electroconductive adhesive and method for manufacturing connected structure using the anisotropic electroconductive adhesive - Google Patents

Abstract

Disclosed is an anisotropic electroconductive adhesive that, even when a heating tool is contacted and pressed at a slow speed, can realize high electrical connection reliability. The anisotropic electroconductive adhesive comprises an insulating adhesive component and electroconductive particles dispersed in the insulating adhesive component. The insulating adhesive component comprises a radical polymerizable compound, a radical initiator, and a film forming resin. The lowest melt viscosity of the anisotropic electroconductive adhesive is in the range of 100 to 800 Pas, and the temperature at which the adhesive exhibits the lowest melt viscosity is in the range of 90 to 115 DEG C.

Description

[Technical Field] The present invention relates to an anisotropic conductive adhesive comprising an electrically conductive particle dispersed in an insulating adhesive component, and a method for producing a bonded structure using the same. [Prior Art] Conventionally, in a FOG (Film on Glass) bonding in which a glass substrate and a flexible printed wiring board (FPC: ❺ Flexlble Printed Circuits) are bonded, a terminal electrode of a glass substrate and a flexible printed wiring board are used. The connection terminals are opposed to each other by the anisotropic conductive adhesive, and the anisotropic conductive adhesive is heated and hardened by a heating tool, and the terminal electrodes are pressed to electrically connect the two terminal electrodes (Patent Document). However, the linear expansion coefficient (1 〇 to 4 Å) of the polyimine resin which is a substrate of the flexible printed wiring board is generally used <1〇-6/. (:), is a line larger than glass

_ expansion coefficient (about 8.5x10 6 / art), so the flexible printed wiring board will have a greater degree of expansion (expansion) than the glass substrate due to the heat of the heating tool when F〇G is joined, so the terminals of the two substrates The size of the electrodes may vary depending on the size, and if the pitch of the terminal electrodes is small, there is a tendency that it is difficult to sufficiently electrically connect. Therefore, in practice, the design interval of the terminal electrodes of the flexible printed wiring board is formed to be narrower than the design interval (sometimes referred to as a predetermined interval) of the terminal electrodes of the corresponding glass substrate. When the anisotropic conductive adhesive is heat-hardened, the heat of the heating tool can be expanded to a distance of 3 201012894 to suppress the size of the terminal electrodes of the glass substrate and the flexible printed wiring board. . CITATION LIST OF THE INVENTION PROBLEM TO BE SOLVED BY THE INVENTION However, the design interval of the terminal electrodes of the flexible printed wiring board is formed to be narrower than a predetermined interval, and fog bonding is performed. The operating conditions of the heating tool vary slightly with individual FOG bonding, or the operating conditions of the heating tool are slightly changed due to manufacturing requirements, which sometimes causes the anisotropic conductive adhesive to fail to achieve good electrical connection. . At this time, in order to prevent or suppress the sufficient connection of the terminal of the board to the end glass substrate of the glass substrate and the flexible printed circuit board, it has been proposed to contact the plate at a relatively fast speed to ensure the flexibility of forming the narrower one. Expansion of the terminal to the glass substrate is considered to be 0. The anisotropic conductive adhesive is hardened before the printed wiring is made, thereby achieving a thermal tool between the two terminal electrodes and the conductive particles for the flexible printed wiring, pressing However, in this case, there is a possibility that the necessary time required for the interval between the terminals of the terminal electrodes of the printed wiring board is less than that of the glass, and the heating tool is used for the flexible printed wiring; In this way, it is ensured that the terminal electrode of the substrate of the terminal electrode of the 20% flexible printed wiring board is "required: 201012894", the anisotropic conductive adhesive is thermally hardened before being fully extruded, so There is a concern that the two terminal electrodes of the glass substrate and the flexible printed circuit board cannot be sufficiently connected to the conductive particles. When the heating tool is brought into contact with and pressed against the flexible printed wiring board, the speed is high. After the pressing of the heating tool is completed, the flexible printed wiring board generates internal stress due to cooling shrinkage. In particular, the interval between the terminal electrodes is as large as that of the flexible printed circuit board, and the internal stress is also increased. When the size is increased, there is a concern that the connection reliability is lowered. Therefore, it has been desired to develop an anisotropic conductive adhesive having a high stress relaxation ability. The object of the present invention is to solve the above problems and to provide an anisotropic conductive adhesive. , which can achieve high electrical connection reliability even in the case of contact and pressing under the condition that the heating tool is slow; and provide one The manufacturing method of the connection structure using the anisotropic conductive adhesive is used as a means for solving the problem. As a result of intensive studies, the present inventors have found that a radically polymerizable compound is mainly used as an anisotropic conductive adhesive. The hardening component, on the other hand, makes the lowest melt viscosity in the range of 100 to 800 Pa.s, and the temperature reaching the lowest melt viscosity is in a very narrow range of 90 to urc, even if the speed of the heating tool is slow, The present invention is accomplished by achieving a benign conductive connection. The present invention provides an anisotropic conductive adhesive which is based on a radical-containing polymer. [Bio-compound, radical initiator, and film-forming resin) 201012894 The conductive paste is dispersed in the component, and the lowest melt viscosity is in the range of 100 to 800 Pa·s, and the temperature indicating the lowest melt viscosity is in the range of 90 to 115 ° C. Further, the present invention A method of manufacturing a connection structure is also provided, which uses an anisotropic conductive adhesive to form a glass of a terminal electrode at a predetermined interval. The glass substrate is connected to a flexible printed wiring board having terminal electrodes formed at a narrower interval than the predetermined interval, and is characterized by the following steps (A) and (B): (A) the configuration step is to apply for a patent The anisotropic conductive adhesive of the above item is disposed between the terminal electrode of the glass substrate and the terminal electrode of the flexible printed wiring board; (B) the connecting step is performed from the flexible printing using a heating tool The wiring board side is pressed, and the heating is performed at a temperature higher than the minimum melting viscosity to electrically connect the terminal electrodes. Advantageous Effects of Invention The anisotropic conductive adhesive of the present invention has the following characteristics: the minimum melting degree is 100. 800 Pa . s ' and the temperature showing the lowest melt viscosity is 9 〇 to 115 ° C. Therefore, the use of the anisotropic conductive adhesive of the present invention to connect the glass substrate forming the terminal electrode at a predetermined interval, and at a predetermined interval When the flexible printed wiring board of the terminal electrode is formed at a narrow interval, the terminal electrodes of the flexible printed board can be sufficiently spaced (four), and on the other hand, the anisotropic conductive connection can be ensured. Even agent sandwiched between the glass substrate and the status of the harness may be printed wiring board remains high flowability. As a result, it is possible to provide a connection structure which has a high connection reliability even if the extrusion speed of the heating fixture is slightly different in manufacturing or the extrusion speed is low. [Embodiment] One embodiment of the present invention will be described. Note that the numerical range "X to Yj is below the table, and the drawings are referred to, and the meanings of xs and s γ are not particularly shown in the present specification. The anisotropic conductive connection of the present invention is a defensive adhesive. Free radical polymerizability

The compound, the radical initiator, and the insulating component of the MJ film are made of conductive particles, and the composition is -# The test is characterized by the lowest melt viscosity at 10G~_Pa.s The range is preferably in the range of (10) to 雠 s; and the temperature at which the lowest melt viscosity is displayed is between 9 〇 and 115 。. The range of 〇 is preferably in the range of 95 to U0 Pa.s. In the present invention, the reason why the lowest melt viscosity is 1 〇〇 to 8 〇〇 1 ^ _ 3 is that if the lowest melt viscosity is 100 Pa s or more, excessive flow of the anisotropic conductive adhesive during heat pressing can be avoided. The result ensures the required amount of bonding between the terminal electrodes. In addition, when the minimum melt viscosity exceeds 800 Pa·s, the fluidity at the time of heating and pressing of the anisotropic conductive adhesive is lowered. Then, the thickness becomes larger than the diameter of the conductive particles, and as a result, the connection reliability is lowered. Further, the following description explains the reason why the temperature at which the lowest melt viscosity is set is 9 〇 to 115 °C. First, the minimum melting temperature is below 90. (: an anisotropic conductive adhesive, because the subsequent heating and pressing will cause the melt viscosity to reach the rising region earlier, resulting in a rapid decrease in fluidity. Thus, the flexibility of the terminal electrode is formed at a predetermined interval at a narrow interval. Before the expansion of the printed wiring board, most of the anisotropic conductive adhesive hardens, and the contact between the terminal electrodes of the glass substrate and the flexible printed wiring board and the conductive particles is made. On the other hand, the anisotropic conductive adhesive having a minimum melting temperature exceeding ll5 ° C, at the end of a predetermined time of heating and pressing by the heating tool, the hardening reaction itself is still insufficiently performed. The contact between the terminal electrode of the glass substrate and the flexible printed wiring board and the conductive particles is insufficient. As described above, in the present invention, the minimum melting viscosity is in the range of ～800 Pa·s, and the display is performed. The temperature of the lowest melt viscosity is in the range of 9 〇 to 115 ° C, so the lowest melt viscosity is divided by the value showing the lowest melt viscosity [(minimum melting) The optimum range of viscosity) / (the temperature showing the lowest melt viscosity) is 0.88 to 8.8. In addition, the value of [(minimum melt viscosity) / (the temperature showing the lowest melt viscosity)] is even within the above-mentioned optimum range, if If at least one of the lowest melting viscosity and the temperature indicating the lowest melting viscosity is outside the optimum range, the cause of poor connection may occur. The conductive particles of the anisotropic conductive adhesive of the present invention may be used, for example. Metal particles such as nickel, gold, and copper, gold plating or the like on the resin particles, and insulating coatings on the outermost layer of particles coated with gold-plated resin particles. Here, the average particle diameter of the conductive particles is turned on. From the viewpoint of reliability, it is preferably 1 to 2, and preferably 2 to 1 Å//m. Further, the content of the conductive particles in the insulating adhesive component is from the conduction reliability and From the viewpoint of insulation reliability, it is preferably 2 to 5 〇 mass%, more preferably 3 to 2 〇 mass 201012894%. The insulating splicing component contains at least a radical polymerizable compound, a radical, as described above. Polymerization initiator And a film-forming resin. As the radical polymerizable compound, a (meth) acrylate monomer such as dicyclopentene sulfonate (meth) acrylate or a phosphorus (meth) acrylate may be used; a (meth) acrylate oligomer such as an acrylamide acrylate or a (meth) acrylate polyester, which further contains a dicyclopentenyl (meth) acrylate monomer, and (methyl) At least one of the acrylamide phthalate chelating polymers is preferred because it can suitably take into consideration the melt viscosity and the curing rate. Further, it may be used in combination with such effects without damaging the effects of the present invention. Other radical polymerizable compounds in which the monomer and the polymer are radically polymerized.

As the radical initiator, a known radical polymerization initiator can be used, and among them, a peroxide radical initiator can be preferably used. Specific examples of the peroxide-based radical initiator include dioxane peroxides such as benzamidine peroxide; tertiary isobutyl peroxybutyrate; tertiary butyl benzoate; Peroxidic ketamines such as 1,2-di(tri-butyl peroxy) cyclohexane. In addition, as a commercial product, NYPER BW (one thiol peroxide, Nippon Oil Co., Ltd.), NYPER MT K40 (one thiol peroxide, Nippon Oil Co., Ltd.), Β〇 (one 醯 base) can be used. Peroxide, Nippon Oil Co., Ltd., NYPER FF (dimercapto peroxide, Nippon Oil Co., Ltd.), NYPER BS (dimercapto peroxide, Nippon Oil Co., Ltd.), NYPER E (diode) Base peroxide, Nippon Oil Co., Ltd., NYPER Ns (dimercapto peroxide, Nippon Oil Co., Ltd.), pERHEXYL (peroxide ester, Nippon Oil Co., Ltd.), 9 201012894 PERBUTYL Ο Oxidized Ester, Nippon Oil Co., Ltd.), PERTETRA A (Peroxyketal, Emu Oil Co., Ltd.), PERHEXA C-80 (S) (Peroxyketal, Nippon Oil Co., Ltd.), PERHEXA C-75 ( EB) (Peroxyketal, Nippon Oil Co., Ltd.), PERHEXA C (C) (Peroxyketal, Emu Oil Co., Ltd.), PERHEXA C (S) (Peroxyketal, Emu Oil Co., Ltd.) , PERHEXA C-40 (Peroxyketal, Nippon Oil Co., Ltd.), PERHEXA C-40MB (S) (peroxide ketal, Nippon Oil Co., Ltd.), PERHEXYL I (peroxy ester, Nippon Oil Co., Ltd.). These polymeric starters may be used singly or in combination. The film-forming resin imparts film-forming properties to the insulating adhesive component containing the radical polymerizable compound and the anisotropic conductive adhesive which is a component thereof, and is easily formed into a film, and the anisotropic conductive adhesive as a whole is further provided. Increased cohesion. As the film-forming resin, at least one of a phenoxy resin or a mixed resin of a phenoxy resin and an epoxy resin which are produced in the production process of a phenoxy resin can be preferably used. The weight average molecular weight of the oxo resin or the mixed resin is preferably from 20,000 to 60,000, more preferably from 20,000 to 40,000, in view of film strength and fluidity of the anisotropic conductive adhesive. The reason for this is that if the weight average molecular weight is 20,000 or more, excessive flow during heating of the anisotropic conductive adhesive can be avoided. Further, when the weight average molecular weight is 60,000 or less, the fluidity is insufficient. In the present invention, it is preferred that the insulating adhesive component contains a stress relieving agent. The strength of the internal stress generated by the interface portion between the anisotropic conductive adhesive and the glass substrate can be alleviated by the inclusion of the stress relieving agent. As the stress relieving agent, a rubber-based elastic material can be preferably used, and it is preferably used in the shape of particles of 201012894. Examples of the rubber-based elastic material include butadiene rubber (BR) composed of polystyrene, acrylic rubber (acr), and butyl rubber (NBR). Among them, the butadiene rubber (br) composed of polybutadiene has a higher resilience than acrylic rubber (ACR), nitrile rubber (NBR), etc., so that it is possible to absorb a large amount of internal stress. Therefore, it is particularly preferable to use a polybutadiene particle as a stress relieving agent in the present invention. The polybutadiene particles used in the present invention are preferably ones having a smaller modulus of elasticity than the anisotropic conductive adhesive having a higher modulus of elasticity, but if the modulus of elasticity is too small, the endurance is lowered. If the modulus of elasticity is too high, the internal stress of the cured product of the anisotropic conductive adhesive may not be sufficiently reduced. Therefore, it is preferred to use an elastic modulus of lxl 〇 8 to lxl 〇 1 〇 dyn/cm 2 . Further, as an element for sufficiently ensuring electrical connection between the conductive particles and the connection electrode, the average particle diameter of the polybutadiene particles is preferably smaller than the average of the conductive particles from the viewpoint of an important average particle diameter. Particle size. If the average particle diameter of the butadiene particles is too small, the internal stress cannot be completely absorbed. If the average particle diameter of the butadiene particles is too large, there is a concern that the conductive particles and the contact electrodes are not sufficiently electrically connected. Therefore, the average particle diameter is preferably 0.01 to 〇.5/zm. The polybutadiene particles described above are contained in the anisotropic conductive adhesive, and the total amount of the radically polymerizable compound and the film-forming resin is preferably 1 〇 to 3 〇. Parts, more preferably in parts by mass. : If the content ratio is 1Q f or more, the amount of the anisotropic conductive adhesive generated in the anisotropic conductive adhesive can be sufficiently reduced. From the 邛 stress, the right is 3 〇 or less, and the anisotropic conduction is not followed. The film formation of the agent has a bad influence, and in addition, the heat resistance of 201012894 can be avoided. Next, an example of a method for producing an anisotropic conductive adhesive of the present invention will be described. First, a radical polymerizable compound and a film-forming resin are dissolved in a solvent, and then a predetermined amount of a radical initiator and conductive particles are added, and then a stress relieving agent (preferably a polybutadiene particle) is added as needed. ) Carry out the search in the 〇. The mixed solution is applied onto a release film such as a polyester film, and after drying, a cover film is laminated thereon, whereby a film-forming anisotropic conductive adhesive can be obtained. The anisotropic conductive adhesive of the present invention described above can be preferably used for anisotropic conductive connection between a glass substrate such as a liquid crystal panel and a flexible printed wiring board to produce a bonded structure. The method of manufacturing the above-described connection structure will be described below with reference to Figs. 1A and 1B (an explanatory view of a method of joining a glass substrate and a flexible printed wiring board). In the method for producing a connection structure according to the present invention, a glass substrate having terminal electrodes formed at regular intervals and a flexible printed wiring board having terminal electrodes formed at a narrower interval than the predetermined interval are used by using an anisotropic conductive adhesive. Connection, which has the following steps (A) and (B). Step (A) <Configuration Steps> First, the anisotropic conductive adhesive of the present invention described above is disposed between the terminal electrode of the glass substrate and the terminal electrode of the flexible printed wiring board. This configuration step can be carried out by using a conventionally known method in addition to the use of the anisotropic conductive adhesive of the present invention. Here, as shown in FIG. 1A, the terminal electrode 11' formed at a predetermined interval a 12 201012894 is formed on the glass substrate 另外. Further, the switchable printed wiring board 3 is formed at an interval B which is narrower than the predetermined interval A of the glass substrate 1. The terminal electrode 31 is formed. The glass substrate 1' is preferably a glass substrate of a display panel such as a liquid crystal panel. In the predetermined interval, the pitch of the terminal electrode 11 formed by the ITO electrode or the like is basically not referred to as the space between the adjacent electrodes, but the space can be used as a reference. Usually 2 〇 2 〇〇 " m, especially in order to make the effect of the present invention appear to be 20~6 〇βηι. On the other hand, as the flexible printed wiring board 3, a laminated copper foil on a polyimide film substrate (a flexible substrate in which the terminal electrode 3D is formed by etching or the like) is preferably used. The narrow interval β refers to the pitch of the terminal electrodes 31, and basically does not refer to the space between adjacent electrodes, but the space can also be set as a reference. Further, although the interval Α is narrower than a predetermined interval, the degree of stenosis is caused by Glass-based; I or flexible printed wiring board 3 linear expansion coefficient, heating

The temperature, the heating rate, the extrusion strength, and the like are different, and it is usually set to be 0_01 to 1% less than the predetermined interval A, and it is preferable to reduce 〇" to 3% 3%. Contact step (B) <Connection step> Next, a heating tool (not shown) is pressed from the side of the flexible printed wiring board 3 to heat the compacted conductive adhesive at a temperature higher than the minimum melt viscosity. 2, the glass substrate i is electrically connected to the terminal electrodes of the flexible printed wiring board 3 by hardening. That is, the connection step flexible printed wiring board 3 is expanded by heating, and as shown in (7), the interval B' of the terminal electrodes 31 of the printed wiring board 3 is substantially equal to the interval A of the glass substrate sub-electrodes. , terminal electrode " and 31 between: 13 201012894 Electrically connected to the hardened material of the conductive conductive adhesive. Thereby, the body can be constructed. As a preferable heating and grinding condition in the step (B), the heating oil is adjusted so that the temperature of the anisotropic conductive adhesive reaches i 50 to 2 Torr after 4 seconds, and the heating is performed. The tool is pressed against the flexible printed wiring board at a speed of 5 〇 mm / ..., preferably 1 to u > mm / sec, and then pressed at this speed for 4 seconds or more. Specifically, the following conditions are exemplified: a heating tool of 150 to 200 C is used for a relatively anisotropic conduction and a pressing speed of 50 mm/sec, and particularly a case of using a low speed is 10 mm/sec. The pressing speed is heated for 4 seconds or more, preferably 4 to 6 seconds. In this condition, the temperature range of the lowest smelting point of the display of the anisotropic conduction is "90 to 115. 〇, which is higher than the temperature at the start of heating (for example, room temperature), and is used to harden the difference. The directional conductivity is followed by the same! The heating temperature of 2 (15 〇 to 200 C) is low. Therefore, under the above heating conditions, the anisotropic conductive adhesive 2 has a viscosity which decreases after the start of heating and passes through the minimum smelting viscosity ( (10) ~ = 〇Pa· 8), and then increase the hardening. By the above viscosity change, the glass substrate and the flexible printed wiring board can be connected with high sin. In addition, the pressing speed of the heating tool is set to 1 to 5 The reason for 〇mm/sec is that if the pressing speed is slow, the interval between the terminal electrodes 2 of the flexible printed wiring board can be expanded to a predetermined interval, but on the other hand, the anisotropic conductive adhesive is sufficiently pressed. If it has been hardened, the result is that there is a doubt that a good anisotropic conductive connection cannot be achieved. If the speed is faster, there will be an anisotropic conductive adhesive on the terminal electrode of the flexible printed wiring board. The interval is expanded until it is hardened before the interval In the following, the present invention will be specifically described by way of examples. The components used in the examples or comparative examples are as follows. <Radical polymerizable compound> Dicycloalkyl acrylate Pentadienyl Ester (DCP, Xinzhongcun Chemical Industry Co., Ltd.) Methacrylate methacrylate (M-1600, East Asia Synthetic (Shares)) Phosphate-containing methacrylate (PM2, Nippon Kayaku Co., Ltd.) <Free radical polymerization initiator> Peroxide dicarbonate initiator (PERRO YL L, Nippon oil (share)) Dimercapto peroxide initiator (NYPER BW, eucalyptus oil) Peroxy ketal-based initiator (PERTETRA A, eucalyptus oil) Dialkyl peroxide-based initiator (PERCUM YL D, Nippon Oil Co., Ltd.) <Film-forming resin> Bisphenol A / Bisphenol F mixed phenoxy resin (Bis_ A / Bis-F mixed phenoxy resin: weight average molecular weight 60000) (YP-50, Dongdu Chemical Co., Ltd.) Bisphenol bismuth / bisphenol F mixed phenoxy resin (Bis- A/ Bis-F mixed phenoxy resin: weight average molecular weight 30000) (jER-4110, 曰本 epoxy resin (share)) double F-type phenoxy resin (Bis-F phenoxy resin: weight average molecular weight 20000) (jER-4007P, Japan epoxy resin (share)) <stress moderator> Acrylic rubber (weight average molecular weight 1200000) (SG-600LB , Nagase ChemteX (shares) 15 201012894 Polybutadiene particles (average particle size 0. 丨am) < decane coupling agent > decane coupling agent (KBM-503, Shin-Etsu Chemical Co., Ltd.) <Electrically conductive particles > Conductive particles coated with a nickel-gold plating layer of benzoquinone particles (average particle diameter 5 # m, Nippon Chemical Industry Co., Ltd.) Examples 1 to 7 and Comparative Examples 1 to 4

Among the components shown in Table 1, a radical polymerizable compound, a radical initiator, a film-forming resin, and a decane coupling agent are dissolved in toluene as a solvent to prepare an insulating component component solution. Then, 3 parts by mass of conductive particles were added to the insulating adhesive component solution (component parts excluding benzene) to prepare an anisotropic conductive adhesive liquid.

Next, the anisotropic conductive adhesive liquid was applied onto the release-treated poly-Sa film and dried to a thickness of 25 μm to 8 μm. The film was dried under the conditions of 5 minutes to obtain a film-forming anisotropic conductive adhesive. The anisotropic conductive adhesive was cut into strips having a width of 2 mm to obtain samples of the anisotropic conductive films of Examples 1 to 7 and Comparative Examples 1 to 4. (Evaluation) For each of the anisotropic conductive film samples of Examples 1 to 7 and Comparative Example 4, "on-resistance value", "connection reliability, "minimum melt viscosity", and "arrival" are as follows. The temperature of the lowest melt viscosity, and the "space between the terminals" that occur during the connection are measured and stretched. The results obtained are not in Table 2. 16 201012894 < (1) On-resistance value> Use a stainless steel block. (:, pressure 3) 'The anisotropic conductive film sample is heated and compacted under conditions of 180 澄 Chengli 3.5 Mpa, kidney squeaking, it ^ M f# 'time 4 seconds, to make the transport structure' The 〇 π " connection resistance value of the structure of the gold twisting tool. In addition, the catching degree of the adding tool is performed at five speeds of 5 〇, 3 〇, 1 〇, ^, 〇.lmm /sec Resistance value 仃 'Receiving material is not (four) degree heating fixture conduction ❹ U U) connection reliability> ^ Using the connection structure as described above to determine the on-resistance value to: two Ray degrees Conditions for 5 〇 ° hour aging test 疋 疋 conduction resistance. <(3) Minimum melt viscosity and temperature showing the lowest melt viscosity> The curable conductive adhesive liquid is not hardened to remove the benzene to make it (4) Rotary meter, 1 (4) The heating rate (HTC / min) is heated - The melt viscosity was measured. < (4) The gap between the terminals> The connection structure in which the anisotropic conductive film samples were connected was visually observed from the glass substrate side using an optical microscope, and the presence or absence of voids was observed. 17 201012894 Comparative example inch 1 1 〇t (N l 1 ο ΓΛ ! 1 vn 〇 1 1 1 tn ο ΓΟ (N 1 un ^T) Ο 1 in 1 1 tTi ο 1-Η 实施 Example 1 to »ri I〇ο 1 inch 1 »r> ο ν-^ CO 1 ο Η 1 r4 irj r4 t ο ΓΟ I in yn ο 1 «〇1 1 in CO inch i tn *r\ 1-H ο »"Η i 1 i in mm 1 JTi ο »-Η 1 1 1 ο CO (N 1 沄1 ο i in 1 1 ο r—^ ΓΟ o 1 o — ο Τ-Η 1 in 1 1 IT) ο 1·^ m Compare Example 1 1 i-1 ο 1 V) 1 1 ο »-Η ΓΛ Anisotropic conductive adhesive composition (parts by mass) Bis-A/Bis-F mixed phenoxy resin Mw=60000 Bis-A/Bis- F mixed phenoxy resin Mw=30000 Bis-F mixed phenoxy resin Mw=20000 Dicyclopentadienyl dimethacrylate (DPC) Amino phthalic acid decyl acrylate (Μ1600) Phosphonic methacrylate (ΡΜ2) PERROYL L NYPERBW PERTERAA PERCUMYLD Acrylic rubber polybutadiene particles ΚΒΜ-503 Conductive particle film forming resin radical polymerizable compound radical polymerization initiator stress relaxation agent coupling agent 201012894

201012894 (Evaluation results) From the results of Table 1 and Table 2, it is understood that the sample of the anisotropic conductive adhesive prepared by the combination of Examples j to 7 has a minimum melt viscosity of 100 to 800 Pa·s. When the heating tool speed of the connection structure using the sample of the examples was in the range of 10 to 5 mm/sec, the on-resistance values were all 1 Ω or less, and the initial connection state was good. Further, it is also known that the embodiments do not increase the resistance value by more than 5 Ω even after a predetermined aging treatment, and the connection reliability is high.

On the other hand, the connection structure using the sample of the comparative example showed a low on-resistance value when the speed of the 10 hot tool was relatively high, but it was 10 Ω at 1 〇mm / sec. The temperature at which the sample of the comparative example reaches the lowest melt viscosity is appropriate, but the lowest melt viscosity itself is 1 〇〇〇Pa.s, which is a poor fluidity. The above situation is considered to be that the heating tool is fast and stylish, but if the heating tool is at a low speed, the spacing of the terminal electrodes of the flexible printed wiring board is extended to the predetermined interval of the terminal electrodes on the glass substrate, and the anisotropy The conductive film has reached the rising region of the melt viscosity by the lowest melt viscosity, and the contact between the two terminals G electrodes of the glass substrate and the flexible printed wiring board and the conductive particles is insufficient, and the electrical connection of the connection structure is poor. Using the joined structure of the sample of Comparative Example 2, no void occurred at any of the heating tool speeds. The occurrence of voids does not directly cause electrical connection failure of the connected structure, but it is still a cause of poor connection. The sample of Comparative Example 2 was suitable for the temperature at which it reached the lowest melt viscosity, but the lowest melt viscosity itself was 70 Pa. The s was low, so the cause of excessive flow was recognized as 20 voids. Using the connection structure of the sample of Comparative Example 3, the rectification resistance value of the trajectory was 1 Ω or less at the speed of the heating tool in the range of 1 〇 to 50 mm/sec, and the initial connection state was good. . However, the prisoner's aging treatment resulted in a significant increase in the on-resistance value. Comparative Example 3, the lowest melting

The viscosity of 250 Pa · s is appropriate, but the temperature at which the lowest melt viscosity is 120 ° C is higher. Therefore, it takes time to finally cure until the hardening is caused. As a result, it is considered that the electrical connection of the connection structure is silent. The connection structure of the sample of Comparative Example 4 is used, and if the heating tool speed is a low speed region of 10 mm/sec, The on-resistance value will rise. The sample of Comparative Example 4 had a minimum melt viscosity of 900 Pa. The 8 genus was higher, and the temperature at which the lowest melt viscosity reached 88 ° C was lower. Therefore, it is considered that the anisotropic conductive adhesive has reached the rising region of the melt viscosity by the lowest melt viscosity. Therefore, the right heating tool speed is a low-speed region, and the contact between the two terminals and the conductive particles is insufficient, and the result is considered to be connected. Poor electrical connection to the structure. <Flexibility of flexible printed wiring board> In the connection structure of the anisotropic conductive film samples of Examples 1 to 7, 'the connection structure was measured for Example 2 and Example 3 The expansion ratio of the flexible printed wiring board. The results obtained are shown in Table 3. The above-described expansion ratio was calculated by measuring the length of the flexible printed wiring board before and after the heat pressing using a two-dimensional length measuring machine. Further, a glass substrate (trade name: Corning 173 7F, manufactured by Corning Co., Ltd.) used for the connection structure and a polyimide (Kapt〇n_EN, 21 201012894) as a substrate of the flexible printed wiring board are used.

The coefficient of thermal expansion of Dupont-Toray Co., Ltd. is 3 ?χΐ〇-6/ it and 16xl (T6/°C. Table 3: Anisotropy conductive crucible sample pressing speed (mm / sec) 1.0 10 30 Example 2 0.20 0.15 0 in Example 3 0.20 0.14 0.10 As can be seen from Table 3, in the case where the temperature of the heating tool used in the embodiment is relatively slow in the temperature, pressure and time of the heating tool, the stretchability of the printable printed wiring board Therefore, it can be seen that even if the same structure is used, the amount of expansion and contraction must be considered in the case where the heating fixture is heated at a slow speed. The expansion ratio is generally the temperature and heating of the heating tool. The speed of the tool, the linear expansion coefficient of the polyimine of the flexible printed wiring board, and the thickness of the 'in the low speed region (1. 〇~10 mm/sec), as shown in Table 3, the stretching: 〇 range is 0.1 to 0.25 Industrial Applicability The anisotropic conductive adhesive of the present invention can achieve high electrical connection reliability even in the case of contact and pressing under conditions in which the speed of the heating tool is slow, so that it can be used for display such as a liquid crystal panel. An anisotropic conductive connection between a glass substrate and a flexible printed wiring board. 22 201012894 BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1A is an explanatory view showing a method of joining a glass substrate and a flexible printed wiring board. 1B is an explanatory view showing a method of joining a glass substrate and a flexible printed wiring board, as shown in FIG. 1A.

[Main component symbol description] 1 Glass substrate 2 Anisotropic conductive adhesive 3 Flexible printed wiring board 11,31 Terminal electrode 23

Claims (1)

201012894 VII. Patent application scope: 1. An anisotropic conductive adhesive consisting of a radically polymerizable compound, a radical initiator, a film-forming resin, and an insulating material, which is composed of conductive particles. The characteristics of the knife are as follows: The minimum melt viscosity of the knife is in the range of 100~8〇〇Pa. S: ^ The temperature of the minimum immersion melt viscosity is in the range of 90~115 °C. 2. For example, the value of the anisotropic conductive adhesive (the lowest melt viscosity) / (the temperature showing the lowest melt viscosity) of the scope of patent application i, L, such as the anisotropic guide of the i or 2 of the patent application scope And further comprising a stress relieving agent. 4. An anisotropic conductive adhesive as claimed in claim 3, wherein the stress relieving agent is a polybutadiene particle. 5. The anisotropic conductive adhesive according to the fourth aspect of the invention, wherein the poly' dilute particles are contained in an amount of from 1 to 3 Å in relation to a total of 75 parts by mass of the radically polymerizable compound and the film-forming resin. Parts by mass. ❿ 6. The anisotropic conductive adhesive of claim 4, wherein the polybutadiene particles have an elastic modulus & h 1010 dyn/cm 2 . The anisotropic conductive subsequent agent of any one of the fourth to sixth aspects of the invention, wherein the average particle diameter of the polybutadiene particles is a claw. 8. The anisotropic conductive connector according to any one of the preceding claims, wherein the film-forming resin comprises a phenoxy resin having a weight average molecular weight of 66_〇, or a phenoxy resin and a ring The oxygen resin is composed of at least one of a mixed resin having a weight average molecular weight of 20,000 to 60000. 9. The anisotropic conductive adhesive according to any one of claims 1 to 8, wherein the radical polymerizable compound contains a (cyclo)acrylic acid dicyclopentene S monomer, and (methyl At least one of the urethane acrylate oligomers. 10. A method of manufacturing a connection structure, wherein a glass substrate on which a terminal electrode is formed at a predetermined interval and a flexible printed wiring board in which a terminal electrode is formed at a narrower interval than the predetermined interval is used using an anisotropic conductive adhesive The connection of the ® is characterized by the following steps (A) and (B): (A) the step of disposing the anisotropic conductive adhesive of the first application of the patent scope on the terminal electrode of the glass substrate (B) The step of connecting is performed by pressing the flexible printed wiring board side with a heating tool, and heating is performed at a temperature higher than the minimum melting viscosity. The electrical connection between the terminal electrodes is made. ❹ n. The manufacturing method of the connection structure of claim 10, wherein in the step (B), the heating tool is adjusted such that the temperature of the anisotropic conductive adhesive reaches 150 after 4 seconds. At 200 ° C, the heating tool abuts the flexible printed wiring board at a speed of 1 to 50 mm/sec, and is heated and pressed at this speed for 4 seconds or more. 12. The method of manufacturing a connection structure according to the first aspect of the invention, wherein in the step (B), the heating tool is adjusted such that the temperature of the anisotropic conductive adhesive reaches 150 after 4 seconds. In 2001, the heating tool abuts the flexible printed wiring board at a speed of 1 to 10 mm/sec, and is heated and pressed at a speed of 25 201012894 for 4 seconds or more. Eight, schema: (such as the next page) 26