JP5972009B2 - CIRCUIT CONNECTION MATERIAL, AND METHOD FOR PRODUCING MOUNTING BODY USING THE SAME - Google Patents

Description

  The present invention relates to a circuit connecting material for connecting electronic components and a method for manufacturing a mounting body using the same.

  Conventionally, as a circuit connection material for connecting an electronic component to a substrate, for example, a tape-like anisotropic conductive film (ACF) in which a binder resin in which conductive particles are dispersed is applied to a release film is used. .

  The anisotropic conductive film, for example, a so-called bonding between a terminal of a flexible printed circuit board (FPC) or an IC chip and an ITO (Indium Tin Oxide) electrode formed on a glass substrate of an LCD (Liquid Crystal Display) panel. Used for film on glass (FOG), chip on glass (COG) and the like.

  In recent years, a technique has been used to improve the trapping efficiency of conductive particles using an anisotropic conductive film having a two-layer structure in which an ACF layer having conductive particles and an NCF layer made of an insulating resin are laminated. (For example, refer to Patent Documents 1 to 3.)

  FIG. 10 is a cross-sectional view for explaining connection using a conventional anisotropic conductive film having a two-layer structure. This anisotropic conductive film has a two-layer structure in which an ACF layer 111 having conductive particles and an NCF layer 112 made of an insulating resin are laminated. For the purpose of preventing dust adhesion, a cover film 121 is attached to the ACF layer 111 side, and a base film 122 is attached to the NCF layer 112 side. Usually, the peeling force of the base film 122 / NCF layer 112 is set larger than the peeling force of the cover film 121 / ACF layer 111, and the cover film 121 side is peeled off during use.

  When using this two-layer anisotropic conductive film, first, the cover film 121 is peeled off, and the ACF layer 111 is attached to the glass substrate 130. Next, the base film 122 is peeled off, and the NCF layer 112 is attached to the FPC 140.

  At the time of crimping, the terminal 141 of the FPC 140 enters the NCF layer 112 and is further electrically connected to the ITO electrode 131 by sandwiching conductive particles in the ACF layer 111. For this reason, the number of conductive particles flowing between the terminals of the electronic component is reduced, and the proportion of conductive particles captured by the connection terminals (particles) even when the amount of conductive particles is small compared to that of the single-layer structure (Capturing efficiency) can be improved.

  On the other hand, as shown in FIG. 11, when the ACF layer 111 is attached to the FPC 140 and the NCF layer 112 is attached to the glass substrate 130, the trapping efficiency of the conductive particles is lowered.

  Therefore, in the conventional anisotropic conductive film having a two-layer structure, it is necessary to adjust the peeling force between the cover film 121 and the base film 122 in advance depending on which of the glass substrate 130 and the FPC 140 is bonded first. After the peel force is adjusted, the bonding order is limited.

  As a method in which the bonding order is not limited, as shown in FIG. 12, a method of forming a three-layer structure of NCF layer 112A / ACF layer 111 / NCF layer 112B can be considered, but the trapping efficiency of conductive particles is lowered.

JP 2009-170898 A JP 2008-248065 A JP-A-11-241049

  The present invention has been proposed in view of such a conventional situation, and provides a circuit connection material capable of releasing a desired release film and a method of manufacturing a mounting body using the same.

  As a result of diligent study, the present inventors have peeled off a desired release film by blending one outermost adhesive layer of a circuit connecting material with a surface conditioner that suppresses an increase in peel force during heating. I found it possible.

That is, the circuit connection material according to the present invention has a first adhesive layer and a second adhesive layer containing a surface conditioner, and is attached to the first adhesive layer side at room temperature. release force of the first release film, the second rather smaller than the release force of the release film attached on the second adhesive layer side, when heated, is affixed to the first adhesive layer side first release force of the release films, characterized in size Ikoto than the release force of the second release film attached on the second adhesive layer side.

Moreover, the manufacturing method of the mounting body which concerns on this invention has a 1st adhesive bond layer and the 2nd adhesive bond layer containing a surface conditioning agent, and the said 1st adhesive bond layer side is normal temperature. peel force of the first release film affixed is the second rather smaller than the release force of the release film attached on the second adhesive layer side, upon heating, the first adhesive layer side peel force of the first release film affixed is the second release film of the first magnitude has the circuit connecting material than the release force of the second release film attached on the adhesive layer side or the second A peeling step of peeling the release film of 2 and the first adhesive layer side or the second adhesive layer side of the circuit connecting material peeled in the peeling step is temporarily attached to the first electronic component, A crimping step of crimping the first electronic component and the second electronic component via the circuit connection material; The serial separation step, and separating the first release film by cold, and then exfoliating the second release film by heating.

  According to the present invention, one outermost adhesive layer of the circuit connecting material is blended with a surface conditioner that suppresses an increase in peeling force when heated, and the other outermost adhesive layer side peels at room temperature. Since the force is reduced, the desired release film can be released depending on the temperature.

It is sectional drawing which shows the circuit connection material which concerns on this Embodiment. It is sectional drawing explaining peeling of the peeling film in the circuit connection material at the time of normal temperature. It is sectional drawing explaining peeling of the peeling film in the circuit connection material at the time of a heating. It is a figure for demonstrating the connection in the case of peeling the 2nd peeling film 22 by heating. It is a figure for demonstrating the connection in the case of peeling the 1st peeling film 21 by normal temperature. It is a graph which shows the relationship of the peeling force with respect to the temperature of the adhesive sheet of Example 1. It is a graph which shows the relationship of the peeling force with respect to the temperature of the adhesive sheet of Example 2. It is a graph which shows the relationship of the peeling force with respect to the temperature of the adhesive agent sheet of the comparative example 1. It is a graph which shows the relationship of the peeling force with respect to the temperature of the adhesive agent sheet of the comparative example 2. It is sectional drawing for demonstrating the connection by the conventional anisotropic conductive film of 2 layer structure. It is sectional drawing for demonstrating the connection by the conventional anisotropic conductive film of 2 layer structure. It is sectional drawing for demonstrating the connection by the anisotropic conductive film of 3 layer structure.

Hereinafter, embodiments of the present invention will be described in detail in the following order with reference to the drawings.
1. 1. Circuit connection material and manufacturing method thereof 2. Manufacturing method of mounting body Example

<1. Circuit connection material and manufacturing method thereof>
First, with reference to FIG. 1 to FIG. 3, a function that enables selection of the adhesive layer of the circuit connection material according to the present embodiment will be described.

  FIG. 1 is a cross-sectional view showing a circuit connection material according to the present embodiment. This circuit connecting material has a first adhesive layer 11 and a second adhesive layer 12 containing a surface conditioner, and is attached to the first adhesive layer 11 side at room temperature (25 ° C.). The peeling force of the 1st peeling film 21 made is smaller than the peeling force of the 2nd peeling film 22 stuck on the 2nd adhesive bond layer 12 side.

  FIG. 2 is a cross-sectional view illustrating the peeling of the release film 21 in the circuit connection material at normal temperature. At normal temperature, the peel force of the first release film 21 attached to the first adhesive layer 11 side is greater than the peel force of the second release film 22 attached to the second adhesive layer 12 side. Since it is small, the 1st peeling film 21 becomes peelable.

  Moreover, FIG. 3 is sectional drawing explaining peeling of the peeling film 22 in the circuit connection material at the time of a heating. At the time of heating, the peel force of the first release film 21 attached to the first adhesive layer 11 side is larger than the peel force of the second release film attached to the second adhesive layer 12 side. Therefore, the second release film 22 can be peeled. This is because the surface conditioner blended in the second adhesive layer 12 suppresses an increase in peeling force during heating.

  Thus, since the circuit connection material which concerns on this Embodiment can peel off the desired peeling films 21 and 22 with the temperature at the time of normal temperature or a heating, the 1st adhesive layer 11 and the 2nd adhesive agent It can be selected which of the layers 12 is bonded first.

  As an application example of the circuit connection material according to the present embodiment, an anisotropic conductive film having a two-layer structure in which conductive particles are contained in either the first adhesive layer 11 or the second adhesive layer 12 In view of the possibility that the function of the surface conditioner may be hindered, it is preferable that the first adhesive layer 11 contains conductive particles.

  When the circuit connection material according to the present embodiment is applied to an anisotropic conductive film having a two-layer structure, for example, the first adhesive layer 11 is an ACF (Anisotropic Conductive Film) layer containing conductive particles. When the second adhesive layer is an NCF (Non Conductive Film) layer containing no conductive particles, the ACF layer surface can be exposed at room temperature, and the NCF layer surface can be exposed by heating. Can do. On the other hand, when the first adhesive layer 11 is an NCF layer containing no conductive particles and the second adhesive layer is an ACF layer containing conductive particles, the surface of the NCF layer is exposed at room temperature. The surface of the ACF layer can be exposed by heating.

  Subsequently, a specific example of the circuit connection material according to the present embodiment will be described in detail. The circuit connection material shown as a specific example has a two-layer structure in which a first adhesive layer 11 containing conductive particles and a second adhesive layer 12 containing a surface conditioner are laminated, A first release film 21 is attached to one adhesive layer 11 side, and a second release film 22 is attached to the second adhesive layer 12 side.

  As for the 1st adhesive bond layer 11, electroconductive particle is disperse | distributed in the adhesive composition containing film forming resin, polymeric resin, and a polymerization initiator.

  The film-forming resin corresponds to a high molecular weight resin having an average molecular weight of 10,000 or more, and preferably has an average molecular weight of about 10,000 to 80,000 from the viewpoint of film formation. Examples of the film-forming resin include various resins such as phenoxy resin, polyester urethane resin, polyester resin, polyurethane resin, acrylic resin, polyimide resin, and butyral resin. These may be used alone or in combination of two or more. It may be used. Content of film forming resin is 30-80 mass parts normally with respect to 100 mass parts of adhesive compositions, Preferably it is 40-70 mass parts.

  The polymerizable resin is a radical polymerizable resin, a cationic polymerizable resin, or the like, and can be appropriately selected depending on the application.

  The radical polymerizable resin is a substance having a functional group that is polymerized by radicals, and examples thereof include epoxy acrylate, urethane acrylate, and polyester acrylate. These may be used alone or in combination of two or more. good. Content of radically polymerizable resin is 10-60 mass parts normally with respect to 100 mass parts of adhesive compositions, Preferably it is 20-50 mass parts.

  As the cationic polymerizable resin, a monofunctional epoxy compound, a heterocyclic epoxy resin, an aliphatic epoxy resin, or the like can be used. In particular, it is preferable to use an epoxy resin such as a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a naphthalene type epoxy resin, a novolac type epoxy resin alone or in combination.

  As the polymerization initiator, a radical polymerization initiator, a cationic curing agent, or the like can be appropriately selected depending on the polymerizable resin.

  A well-known thing can be used for a radical polymerization initiator, Especially an organic peroxide can be used preferably. Examples of organic peroxides include peroxyketals, diacyl peroxides, peroxydicarbonates, peroxyesters, dialkyl peroxides, hydroperoxides, silyl peroxides, and the like. It may be used in combination, or two or more types may be used in combination. Content of a radical polymerization initiator is 0.1-30 mass parts normally with respect to 100 mass parts of adhesive compositions, Preferably it is 1-20 mass parts.

  As the cationic curing agent, one in which the cationic species causes the epoxy group at the terminal of the epoxy resin to open and self-crosslinks the epoxy resins can be used. Examples of such cationic curing agents include onium salts such as aromatic sulfonium salts, aromatic diazonium salts, iodonium salts, phosphonium salts, and selenonium salts. In particular, an aromatic sulfonium salt is suitable as a cationic curing agent because of its excellent reactivity at low temperatures and a long pot life.

  Moreover, it is preferable to add a silane coupling agent as another additive composition. As the silane coupling agent, epoxy, amino, mercapto sulfide, ureido, and the like can be used. Thereby, the adhesiveness in the interface of an organic material and an inorganic material can be improved. Moreover, you may add an inorganic filler. As the inorganic filler, silica, talc, titanium oxide, calcium carbonate, magnesium oxide and the like can be used, and the kind of the inorganic filler is not particularly limited. Depending on the content of the inorganic filler, the fluidity can be controlled and the particle capture rate can be improved. A rubber component or the like can also be used as appropriate for the purpose of relaxing the stress of the bonded body.

  Next, the second adhesive layer 12 will be described. The second adhesive layer is an adhesive composition containing a surface conditioner, and the surface conditioner suppresses an increase in peeling force during heating.

  The surface conditioner is a so-called leveling agent and has a function of moving to the surface and reducing the surface tension. Examples of the surface conditioner include silicone-based, acrylic-based, and fluorine-based compounds. Among these, a silicone-based surface conditioner is preferably used from the viewpoint of surface tension lowering ability and compatibility.

  Specific examples of the silicone-based surface conditioner include polyester-modified methylalkylpolysiloxane, polyester-modified polydimethylsiloxane, polyether-modified polydimethylsiloxane, and polyether-modified polymethylalkylpolysiloxane. Among these, polyester-modified methyl alkyl polysiloxane is preferably used from the viewpoint of thermal stability.

  Moreover, the compounding quantity of a silicone type surface conditioning agent is 0.01-10 mass parts normally with respect to 100 mass parts of adhesive compositions, Preferably it is 0.05-5 mass parts. If the blending amount of the silicone-based surface conditioner is too small, the effect of suppressing an increase in peeling force during heating cannot be obtained, and if the blending amount is too large, the film property is deteriorated.

  The adhesive composition of the second adhesive layer 12 contains a film-forming resin, a polymerizable resin, and a polymerization initiator, like the first adhesive layer 11. Moreover, it is preferable to use the same resin as the first resin for the film-forming resin, the polymerizable resin, and the polymerization initiator.

  The first release film 21 and the second release film 22 are made of, for example, PET (Poly Ethylene Terephthalate), OPP (Oriented Polypropylene), PMP (Poly-4-methylpentene-1), PTFE (PTFE). It consists of a laminated structure coated on a substrate such as Polytetrafluoroethylene). Moreover, the peeling force of the 1st peeling film 21 and the 2nd peeling film 22 can be adjusted with the kind of releasing agents, such as silicone, the surface roughness (Rz) of a base material, etc., for example.

  Next, the manufacturing method of the anisotropic conductive film which consists of a circuit connection material mentioned above is demonstrated. In the manufacturing method of the anisotropic conductive film in the present embodiment, the first adhesive layer 11 containing conductive particles and the second adhesive layer 12 containing a surface conditioner are bonded together.

  Specifically, the process of producing | generating the 1st adhesive bond layer 11 containing electroconductive particle, the process of producing | generating the 2nd adhesive bond layer 12 containing a surface conditioning agent, and the 1st adhesive bond layer 11 And a step of attaching the second adhesive layer 12.

  In the step of generating the first adhesive layer 11, an adhesive composition containing a film-forming resin, a polymerizable resin, and a polymerization initiator and having conductive particles dispersed therein is dissolved in a solvent. As the solvent, toluene, ethyl acetate or the like, or a mixed solvent thereof can be used. After adjusting the resin composition of the 1st adhesive bond layer 11, it apply | coats on the 1st peeling film 21 using a bar coater, a coating device, etc. FIG.

  Next, the resin composition applied on the first release film 21 is dried by a heat oven, a heat drying apparatus, or the like. Thereby, the 1st adhesive bond layer 11 about 5-50 micrometers thick can be obtained.

  Moreover, the process of producing | generating the 2nd adhesive bond layer 12 is the adhesive agent containing film forming resin, polymeric resin, a polymerization initiator, and a surface regulator similarly to the 1st adhesive bond layer 11. The composition is dissolved in a solvent to adjust the resin composition of the second adhesive layer 12, and then applied onto the second release film, and the solvent is volatilized to obtain the second adhesive layer 12.

  Next, in the step of attaching the first adhesive layer 11 and the second adhesive layer 12, the first adhesive layer 11 and the second adhesive layer 12 are attached and laminated to form two layers. An anisotropic conductive film having a structure is prepared.

  Thus, by sticking the first adhesive layer and the second adhesive layer, the first adhesive layer 11 and the second adhesive layer 12 are laminated, and the first adhesive layer 11 is laminated. An anisotropic conductive film having a structure in which the first release film 21 is attached to the side and the second release film 22 is attached to the second adhesive layer 12 side can be obtained.

  In the above-described embodiment, the first adhesive layer and the second adhesive layer are attached and manufactured. However, the present invention is not limited to this, and after one adhesive layer is formed Alternatively, the other adhesive layer resin composition may be applied and dried.

<2. Mounting method of mounting body>
Next, a method for mounting an electronic component using the above-described circuit connection material will be described. The electronic component mounting method according to the present embodiment includes a first adhesive layer 11 and a second adhesive layer 12 containing a surface conditioner, and the first adhesive layer 11 side at room temperature. The first electronic component using a circuit connection material in which the peel force of the first release film 21 attached to the sheet is smaller than the peel force of the second release film 22 attached to the second adhesive layer 12 side And the second electronic component are connected.

  That is, the electronic component mounting method according to the present embodiment includes a peeling step of peeling the first release film 21 or the second release film 22 of the circuit connection material, and a first of the circuit connection material peeled in the peeling step. A pressure bonding step in which the first adhesive layer side or the second adhesive layer side is temporarily attached to the first electronic component, and the first electronic component and the second electronic component are pressure-bonded via the circuit connecting material. Have.

  In the peeling step, the first peeling film 21 is peeled off at room temperature, and the second peeling film 22 is peeled off by heating. Moreover, when heating a circuit connection material in a peeling process, in order to prevent an unexpected hardening reaction, it is preferable to heat from the 2nd peeling film 22 side.

In the crimping step, the first adhesive layer side 11 or the second adhesive layer 12 side is temporarily attached to the first electronic component. For example, when the first adhesive layer 11 is an ACF layer containing conductive particles and the second adhesive layer 12 is an NCF layer containing no conductive particles, the first adhesive layer side 11 is The electronic component to be bonded is, for example, ITO (Indium Tin Oxide) coating glass, IZO (Indium Zinc Oxide) coating glass, SiN _x (silicon nitride) coating glass, or the like. Moreover, the electronic component which adhere | attaches the 2nd adhesive bond layer side 12 is a flexible printed circuit board (FPC), an IC chip, etc., for example.

  FIG. 4 is a diagram for explaining connection in the case where the second release film 22 is peeled off by heating. When the first adhesive layer 11 is an ACF layer containing conductive particles and the second adhesive layer 12 is an NCF layer containing no conductive particles, as shown in FIG. By peeling off the film 22, first, the NCF layer side is temporarily attached onto the electrode 41 of the FPC 40. At this time, when repair is necessary, the FPC 40 on the component side may be replaced without replacing the glass substrate 30 on the main body side, which is advantageous in terms of the process.

  Moreover, FIG. 5 is a figure for demonstrating the connection in the case of peeling the 1st peeling film 21 by normal temperature. When the first adhesive layer 11 is an ACF layer containing conductive particles and the second adhesive layer 12 is an NCF layer containing no conductive particles, as shown in FIG. By peeling off the film 21, first, the ACF layer side is temporarily attached onto the electrode 31 of the glass substrate 30. At this time, when repair is necessary, the glass substrate 30 on the main body side must be replaced as in the conventional case.

  As described above, in the electronic component mounting method according to the present embodiment, the first adhesive layer 11 and the second adhesive layer 12 can be selected depending on which of the glass substrate 30 and the FPC 40 the circuit connection material is bonded first. The order of adhesion of the circuit connecting material to the adherend is not limited.

<3. Example>
Examples of the present invention will be described below. In this example, an adhesive sheet having a two-layer structure in which an ACF layer containing conductive particles and an NCF layer containing a surface conditioner are laminated is prepared, and the cover film and the NCF layer attached to the ACF layer side are formed. The peel strength of the attached base film was measured. Moreover, about the mounting body which connected FPC and ITO coating glass using the adhesive sheet, the particle | grain capture | acquisition efficiency and the measurement of conduction | electrical_connection resistance were performed. The present invention is not limited to these examples.

  Measurement of peeling force, measurement of particle trapping efficiency, and measurement of conduction resistance were performed as follows.

[Measurement of peel force]
Each adhesive sheet is slit to a width of 1 cm, and this is fixed to a 0.7 mm thick glass plate with a double-sided tape. When measuring the peeling force of the cover film, the base film is peeled off and the NCF layer surface is fixed with a double-sided tape. Moreover, when measuring the peeling force of a base film, a cover film is peeled and an ACF layer surface is fixed with a double-sided tape.

  A test piece was placed on a hot plate heated to the test temperature, the cover film or the base film was peeled upward 90 ° at a speed of 300 mm / min, and the peel force at that time was measured.

  [Measurement of particle trapping efficiency and conduction resistance]

  The number of particles captured by the FPC terminal of the connecting portion of the mounting body was counted, and the particle capturing efficiency was calculated from the number of particles per unit area. Moreover, the connection resistance value when a current of 1 mA was passed was measured using a four-terminal method for the mounted body.

[Example 1]
(Production of ACF layer)

  60 parts by mass of phenoxy resin (product name: YP50, manufactured by Toto Kasei Co., Ltd.), 35 parts by mass of radical polymerizable resin (product name: M-315, manufactured by Toa Gosei Co., Ltd.), and silane coupling agent (product name: KBM-503) Conductive particles are dispersed in a composition composed of 2 parts by mass of Shin-Etsu Silicone Co., Ltd.) and 2 parts by mass of a reaction initiator (product name: Perhexa C, manufactured by NOF Corporation). An ACF layer was produced.

(Preparation of NCF layer)
60 parts by mass of phenoxy resin (product name: YP50, manufactured by Toto Kasei Co., Ltd.), 35 parts by mass of radical polymerizable resin (product name: M-315, manufactured by Toa Gosei Co., Ltd.), and silane coupling agent (product name: KBM-503) , Manufactured by Shin-Etsu Silicone Co., Ltd.), 2 parts by mass of reaction initiator (product name: Perhexa C, manufactured by Nippon Oil & Fats Co., Ltd.), and 2 parts of silicone-based surface conditioner (product name: BYK315, manufactured by Big Chemie Japan Co., Ltd.) An NCF layer having a thickness of 16 μm composed of parts by mass was prepared.

(Preparation of adhesive sheet)
The ACF layer and the NCF layer were laminated at a roll temperature of 45 ° C. using a roll laminator to prepare an adhesive sheet having a structure of cover film / ACF layer / NCF layer / base film.

  PET (silicone treatment) having a thickness of 50 μm was used for the cover film and the base film. In addition, the base film having a base film / NCF layer side peeling force larger than that of the cover film / ACF layer side at room temperature was used.

(Production of mounting body)
Using the adhesive sheet of Example 1, the FPC for evaluation (50 μm P, Cu 8 μmt-Sn plating, 38 μmt) and the ITO coating glass for evaluation (full surface ITO coating, glass thickness 0.7 mm) were bonded. First, the adhesive sheet slit to a width of 1.5 mm was heated to 50 ° C., the base film was peeled off, and the NCF layer side of the adhesive sheet was temporarily attached to the FPC. Next, the cover film was peeled off, and the ACF layer side of the adhesive sheet was attached to ITO coating glass and temporarily fixed. Then, using a sheet of polytetrafluoroethylene with a heat tool of 1.5 mm width and a thickness of 100 μm as a buffer material, pressure bonding is performed under the conditions of 180 ° C.-3.5 MPa-6 sec (tool speed 10 mm / sec, stage temperature 40 ° C.). The mounting body was produced.

(Evaluation results)
Table 1 shows the evaluation results of Example 1. The peel force of the cover film and the base film at normal temperature was 8 mN / cm and 27 mN / cm, respectively, and the peel force of the cover film and the base film when heated at 50 ° C. was 175 mN / cm and 115 mN / cm, respectively. .

  Moreover, in FIG. 6, the relationship of the peeling force with respect to the temperature of the adhesive sheet of Example 1 is shown. From this graph, on the NCF layer side (base film side) containing the silicone-based surface conditioner, an increase in the peeling force due to heating is suppressed, and the strength relationship between the peeling force on the ACF layer side and the NCF layer side is reversed. confirmed. Therefore, it was confirmed that the adhesive sheet of Example 1 was one in which the cover film peeled off at room temperature and the base film peeled off when heated.

  Moreover, the particle | grain capture | acquisition rate of the FPC terminal of the mounting body using the adhesive sheet of Example 1 was 58%, and conduction | electrical_connection resistance was 1.4 ohms.

[Example 2]
An adhesive sheet similar to that in Example 1 was prepared except that the silicone-based surface conditioner (product name: BYK315, manufactured by Big Chemie Japan) of the NCF layer was changed to 0.1 parts by mass. Further, using the adhesive sheet of Example 2, a mounting body was produced in the same procedure as in Example 1.

(Evaluation results)
Table 1 shows the evaluation results of Example 2. The peel forces of the cover film and the base film at room temperature were 10 mN / cm and 32 mN / cm, respectively, and the peel forces of the cover film and the base film when heated at 50 ° C. were 170 mN / cm and 148 mN / cm, respectively. .

  Moreover, in FIG. 7, the relationship of the peeling force with respect to the temperature of the adhesive agent sheet of Example 2 is shown. From this graph, on the NCF layer side (base film side) containing the silicone-based surface conditioner, an increase in the peeling force due to heating is suppressed, and the strength relationship between the peeling force on the ACF layer side and the NCF layer side is reversed. confirmed. Therefore, it was confirmed that the adhesive sheet of Example 2 has a cover film that peels off at room temperature and a base film that peels off when heated.

  Moreover, the particle | grain capture | acquisition rate of the FPC terminal of the mounting body using the adhesive sheet of Example 2 was 54%, and the conduction | electrical_connection resistance was 1.4 ohms.

[Comparative Example 1]
(Production of ACF layer)
60 parts by mass of phenoxy resin (product name: YP50, manufactured by Toto Kasei Co., Ltd.), 35 parts by mass of radical polymerizable resin (product name: M-315, manufactured by Toa Gosei Co., Ltd.), and silane coupling agent (product name: KBM-503) Conductive particles are dispersed in a composition composed of 2 parts by mass of Shin-Etsu Silicone Co., Ltd.) and 2 parts by mass of a reaction initiator (product name: Perhexa C, manufactured by NOF Corporation). An ACF layer was produced.

(Preparation of NCF layer)
60 parts by mass of phenoxy resin (product name: YP50, manufactured by Toto Kasei Co., Ltd.), 35 parts by mass of radical polymerizable resin (product name: M-315, manufactured by Toa Gosei Co., Ltd.), and silane coupling agent (product name: KBM-503) An NCF layer having a thickness of 16 μm was prepared, consisting of 2 parts by mass of Shin-Etsu Silicone Co., Ltd. and 2 parts by mass of a reaction initiator (product name: Perhexa C, manufactured by NOF Corporation).

(Preparation of adhesive sheet)
The ACF layer and the NCF layer were laminated at a roll temperature of 45 ° C. using a roll laminator to prepare an adhesive sheet having a structure of cover film / ACF layer / NCF layer / base film.

  PET (silicone treatment) having a thickness of 50 μm was used for the cover film and the base film. In addition, the base film having a base film / NCF layer side peeling force larger than that of the cover film / ACF layer side at room temperature was used.

(Production of mounting body)
Using the adhesive sheet of Comparative Example 1, the FPC for evaluation (50 μm P, Cu 8 μmt-Sn plating, 38 μmt) and the ITO coating glass for evaluation (full surface ITO coat, glass thickness 0.7 mm) were bonded. First, the adhesive sheet slit to a width of 1.5 mm was heated to 50 ° C., the cover film was peeled off, and the ACF layer side of the adhesive sheet was temporarily attached to the FPC. Next, the base film was peeled off, and the NCF layer side of the adhesive sheet was attached to ITO coating glass and temporarily fixed. Then, using a sheet of polytetrafluoroethylene with a heat tool of 1.5 mm width and a thickness of 100 μm as a buffer material, pressure bonding is performed under the conditions of 180 ° C.-3.5 MPa-6 sec (tool speed 10 mm / sec, stage temperature 40 ° C.). The mounting body was produced.

(Evaluation results)
Table 1 shows the evaluation results of Comparative Example 1. The peel forces of the cover film and the base film at normal temperature were 9 mN / cm and 35 mN / cm, respectively, and the peel forces of the cover film and the base film when heated at 50 ° C. were 168 mN / cm and 255 mN / cm, respectively. .

  Moreover, in FIG. 8, the relationship of the peeling force with respect to the temperature of the adhesive agent sheet of the comparative example 1 is shown. From this graph, it was confirmed that the peeling force on both the ACF layer side and the NCF layer side increased with increasing temperature, and the strength relationship of the peeling force was not reversed. Therefore, it was confirmed that the cover sheet peels off the adhesive sheet of Comparative Example 1 both at room temperature and during heating.

  Moreover, the particle | grain capture | acquisition rate of the FPC terminal of the mounting body using the adhesive sheet of the comparative example 1 was 35%, and conduction | electrical_connection resistance was 2.4 ohms.

[Comparative Example 2]
An ACF layer and an NCF layer similar to those in Comparative Example 1 were produced. Using a roll laminator, the laminate was laminated at a roll temperature of 45 ° C. to prepare an adhesive sheet having a structure of cover film / NCF layer / ACF layer / NCF layer / base film.

  PET (silicone treatment) having a thickness of 50 μm was used for the cover film and the base film. In addition, the base film having a base film / NCF layer side peeling force larger than that of the cover film / ACF layer side at room temperature was used. In addition, a mounting body was produced in the same procedure as in Comparative Example 1 using the adhesive sheet of Comparative Example 2.

(Evaluation results)
Table 1 shows the evaluation results of Comparative Example 2. The peel force of the cover film and the base film at room temperature was 8 mN / cm and 30 mN / cm, respectively, and the peel force of the cover film and the base film when heated at 50 ° C. was 172 mN / cm and 260 mN / cm, respectively. .

  Moreover, in FIG. 9, the relationship of the peeling force with respect to the temperature of the adhesive agent sheet of the comparative example 2 is shown. From this graph, it was confirmed that the peeling force on both the NCF layer side and the NCF layer side increased with increasing temperature, and the strength relationship of the peeling force did not reverse. Therefore, it was confirmed that the cover sheet peels off the adhesive sheet of Comparative Example 1 both at room temperature and during heating.

  Moreover, the particle | grain capture | acquisition rate of the FPC terminal of the mounting body using the adhesive sheet of the comparative example 2 was 28%, and conduction | electrical_connection resistance was 3.5 ohms.

  As shown in Table 1, in Example 1 and Example 2, the addition of the silicone-based surface conditioner suppresses an increase in the peeling force of the base film / NCF layer during heating, and the base film side can be peeled off. It was. Moreover, when there were few compounding quantities of a silicone type surface conditioning agent, it turned out that the peeling force raise inhibitory effect at the time of heating falls.

  In Comparative Example 1, peeling on the base film side during heating was not possible. In addition, when the ACF layer side was attached to the FPC and connected, the particle trapping efficiency was lower than that in Example 1 and Example 2, and the conduction resistance was increased. In Comparative Example 2, the NCF layer can be attached to the FPC with a three-layer structure. However, as in Comparative Example 1, the particle trapping efficiency is low and the conduction resistance is high.

  As described above, by adding a surface conditioner that does not easily increase the adhesion to the release film even when heated to one outermost adhesive layer, the peel strength of the other outermost adhesive layer during heating is added. Only can be greatly increased. Therefore, at the normal temperature, the release film on the surface-conditioner-free layer side can be peeled off, and at the time of heating, the release film on the surface-conditioner-containing layer side can be peeled off. The order of bonding the material to the adherend is not limited.

  DESCRIPTION OF SYMBOLS 11 1st adhesive bond layer, 12 2nd adhesive bond layer, 21 1st peeling film, 22 2nd peeling film, 30 glass substrate, 31 electrode, 40 FPC, 41 electrode, 111 ACF layer, 112 NCF layer 121 cover film, 122 base film, 130 glass substrate, 131 electrode, 140 FPC, 141 electrode

Claims (4)

Having a first adhesive layer and a second adhesive layer containing a surface conditioning agent;
At room temperature, peel strength of the first release film affixed to the first adhesive layer side, rather smaller than the peeling force of the second release film attached on the second adhesive layer side,
Heating time, the first release force of the release film attached on the first adhesive layer side, the second has large circuit than the release force of the second release film attached on the adhesive layer side Connection material. The surface modifier, circuit connecting material according to claim 1 Symbol placement is a silicone-based surface modifier. It said first adhesive layer, the circuit connecting material according to claim 1 or 2, wherein contains conductive particles. It has a first adhesive layer and a second adhesive layer containing a surface conditioning agent, and at room temperature, the peel strength of the first release film attached to the first adhesive layer side is: the second rather smaller than the peeling force of the second release film attached on the adhesive layer side, upon heating, release force of the first release film affixed to the first adhesive layer side, a separation step of separating the first release film or the second release film size has the circuit connecting material than the release force of the second release film attached on the second adhesive layer side,
The first adhesive layer side or the second adhesive layer side of the circuit connection material peeled off in the peeling step is temporarily attached to the first electronic component, and the first electronic component and the second electronic component are temporarily attached. A crimping step of crimping a component through the circuit connecting material,
In the peeling process, the first peelable film is peeled off at room temperature, and the second peelable film is peeled off by heating.

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