JP2012155936A - Manufacturing method of connection structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a connection structure capable of further improving conduction reliability by preventing displacement between electrodes.SOLUTION: A manufacturing method of a connection structure 1 according to the invention includes steps of: placing an anisotropic conductive material layer including conductive particles 5 on a first connection target member 2 having an electrode 2b on its top surface 2a; obtaining a laminate of the first connection target member 2, the anisotropic conductive material layer, and a second connection target member 4 by laminating the second connection target member 4 having an electrode 4b on its undersurface 4a on the top surface of the anisotropic conductive material layer; temporarily crimping the laminate; and permanently crimping the temporarily crimped laminate by curing the anisotropic conductive material layer. In the manufacturing method of the connection structure 1 according to the invention, the minimum melting viscosity at 60-100°C of the anisotropic conductive material layer of the laminate before the temporary crimp is made 3000 Pas or more and at 20000 Pas or less.

Description

  The present invention relates to a method for manufacturing a connection structure using an anisotropic conductive material containing conductive particles, and more specifically, for example, electrodes of various connection target members such as a flexible printed board, a glass substrate, and a semiconductor chip. The present invention relates to a method for manufacturing a connection structure in which a space is electrically connected via conductive particles.

  Pasty or film-like anisotropic conductive materials are widely known. In the anisotropic conductive material, a plurality of conductive particles are dispersed in a binder resin or the like.

  The anisotropic conductive material is, for example, a connection between a flexible printed circuit board and a glass substrate (FOG (Film on Glass)), a connection between a semiconductor chip and a flexible printed circuit board (COF (Chip on Film)), or a semiconductor chip. It is used for connection with a glass substrate (COG (Chip on Glass)) and the like.

  For example, when the semiconductor chip electrode and the glass substrate electrode are electrically connected by the anisotropic conductive material, the anisotropic conductive material is disposed between the semiconductor chip electrode and the glass substrate electrode. Then, heat and pressurize. As a result, the anisotropic conductive material is cured, and the electrodes are electrically connected via the conductive particles to obtain a connection structure.

  Moreover, as an example of the manufacturing method of the said connection structure, in the following patent document 1, an adhesive composition is arrange | positioned on the 1st circuit member which has a 1st connection terminal, From the upper direction of an adhesive composition. After the light irradiation, the second circuit member having the second connection terminal is disposed oppositely, and the first connection terminal and the second connection terminal disposed oppositely by applying pressure while heating are electrically connected. A method for manufacturing a connection structure to be connected to a cable is disclosed. In Patent Document 1, as the adhesive composition, (A) an epoxy resin, (B) a thiol compound having one or more ester bonds in the molecule, (C) a photobase generator that generates a base by light irradiation, And (D) an adhesive composition containing conductive particles is used.

  Further, as an anisotropic conductive material used for manufacturing the above connection structure, the following Patent Document 2 discloses that the viscosity at 25 ° C. and 2.5 pm is η1, the viscosity at 25 ° C. and 20 rpm is η2. The anisotropic conductive adhesive satisfying the following formulas (A) and (B) is disclosed.

50 Pa · s ≦ η2 ≦ 200 Pa · s Formula (A)
1.5 ≦ η1 / η2 ≦ 4.3 Formula (B)

JP 2007-77382 A JP 2003-064330 A

  In the manufacturing method of the connection structure described in Patent Document 1, the second circuit member is placed on the adhesive material composition placed on the first circuit member and temporarily crimped, and then the second circuit member. Misalignment may occur. For this reason, in the obtained connection structure, the position of the second circuit member may be shifted. When the position of the second circuit member is displaced, there is a problem that the position between the electrodes facing each other of the first and second circuit members is displaced, and the conduction reliability between the electrodes is lowered.

  Further, when the anisotropic conductive adhesive described in Patent Document 2 is used, the conductive particles may not be accurately arranged between the electrodes. For this reason, in the connection structure obtained, there exists a problem that the conduction | electrical_connection reliability between electrodes becomes low.

  An object of the present invention is to provide a method for manufacturing a connection structure that can suppress a positional shift between the electrodes of the first and second connection target members and that can obtain a connection structure excellent in conduction reliability. is there.

  According to a wide aspect of the present invention, a step of disposing an anisotropic conductive material layer including a thermosetting compound, a thermosetting agent, and conductive particles on a first connection target member having an electrode on an upper surface; A second connection target member having an electrode on the lower surface is laminated on the upper surface of the anisotropic conductive material layer, and the first connection target member, the anisotropic conductive material layer, and the second connection target member are stacked. And a step of temporarily press-bonding the laminated body, and a step of curing the anisotropic conductive material layer and finally pressing the temporarily-bonded laminate. There is provided a method for producing a connection structure, wherein the anisotropic conductive material layer of the laminated body has a minimum melt viscosity at 60 to 100 ° C. of 3000 Pa · s or more and 20000 Pa · s or less.

  In a specific aspect of the manufacturing method of the connection structure according to the present invention, the anisotropic conductive material layer in the laminated body before temporary press-bonding is 80 ° C. and the viscosity (Pa · s) at a frequency of 1 Hz is 80 ° C. The viscosity ratio to the viscosity (Pa · s) at a frequency of 10 Hz is 1.5 or more and 6 or less.

  In another specific aspect of the method for manufacturing a connection structure according to the present invention, the anisotropic conductive material layer is formed of an anisotropic conductive paste, and the anisotropic conductive material in the laminate before temporary pressure bonding is used. The material layer is an anisotropic conductive material layer in which the anisotropic conductive paste is B-staged.

  In still another specific aspect of the method for manufacturing a connection structure according to the present invention, the anisotropic conductive material is formed of an anisotropic conductive paste, and in the step of disposing the anisotropic conductive material layer, An anisotropic conductive paste including a thermosetting compound, a thermosetting agent, and conductive particles is laminated on the first connection target member having an electrode on the upper surface, and the anisotropic conductive paste is irradiated with light or By applying heat, an anisotropic conductive material layer formed of the anisotropic conductive paste is disposed.

  In another specific aspect of the method for producing a connection structure according to the present invention, a thermosetting compound, a photocurable compound, a thermosetting agent, a photocuring initiator, and conductive particles are used as the anisotropic conductive material. An anisotropic conductive paste is used.

  In the manufacturing method of the connection structure according to the present invention, the second connection target member is stacked on the upper surface of the anisotropic conductive material layer stacked on the first connection target member, and then the first connection target member is formed. , The anisotropic conductive material layer and the second connection target member are temporarily pressure-bonded and then finally pressure-bonded. Since the minimum melt viscosity at ˜100 ° C. is 3000 Pa · s or more and 20000 Pa · s or less, it is possible to suppress the displacement between the electrodes of the first and second connection target members. Therefore, a connection structure having excellent conduction reliability can be provided.

FIG. 1 is a front sectional view schematically showing a connection structure obtained by a method for manufacturing a connection structure according to an embodiment of the present invention. 2A to 2C are front cross-sectional views for explaining each step of the method for manufacturing the connection structure according to the embodiment of the present invention.

  Hereinafter, the present invention will be clarified by describing specific embodiments of the present invention with reference to the drawings.

  In FIG. 1, the connection structure obtained by the manufacturing method of the connection structure which concerns on one Embodiment of this invention is typically shown with a partial notch front sectional drawing.

  A connection structure 1 shown in FIG. 1 includes a first connection target member 2, a second connection target member 4, and a connection part 3 connecting the first and second connection target members 2 and 4. Prepare. The connection portion 3 is a cured product layer and is formed by curing an anisotropic conductive material including the conductive particles 5.

  A plurality of electrodes 2 b are provided on the upper surface 2 a of the first connection target member 2. A plurality of electrodes 4 b are provided on the lower surface 4 a of the second connection target member 4. The electrode 2b and the electrode 4b are electrically connected by one or a plurality of conductive particles 5.

  In the connection structure 1, a glass substrate is used as the first connection target member 2, and a semiconductor chip is used as the second connection target member 4. The first and second connection target members are not particularly limited. Specific examples of the first and second connection target members include electronic components such as semiconductor chips, capacitors, and diodes, and circuit boards such as printed boards, flexible printed boards, and glass boards.

  In the manufacturing method of the connection structure according to the present embodiment, the connection structure 1 shown in FIG. 1 is obtained as follows.

  As shown to Fig.2 (a), the 1st connection object member 2 which has the electrode 2b on the upper surface 2a is prepared. An anisotropic conductive material including a thermosetting compound, a thermosetting agent, and conductive particles 5 is prepared. Here, an anisotropic conductive paste including a thermosetting compound, a photocurable compound, a thermosetting agent, a photocuring initiator, and conductive particles 5 is used. Next, an anisotropic conductive material including a plurality of conductive particles 5 is disposed on the upper surface 2a of the first connection target member 2, and the anisotropic conductive material layer 3A is disposed on the upper surface 2a of the first connection target member 2. Form. At this time, it is preferable that one or a plurality of conductive particles 5 be disposed on the electrode 2b. Here, since the anisotropic conductive paste is used as the anisotropic conductive material, the lamination of the anisotropic conductive paste is performed by applying the anisotropic conductive paste.

  Next, as shown in FIG. 2B, the anisotropic conductive material layer 3A is cured by irradiating light or applying heat to the anisotropic conductive material layer 3A. By curing the anisotropic conductive material layer 3A, the anisotropic conductive material layer 3A is B-staged. Here, the anisotropic conductive material layer 3A is irradiated with light to advance the curing of the anisotropic conductive material layer 3A, so that the anisotropic conductive material layer 3A is B-staged. By forming the anisotropic conductive material layer 3A into a B-stage, the B-staged anisotropic conductive material layer 3B is formed on the upper surface 2a of the first connection target member 2.

In order to appropriately cure the anisotropic conductive material layer 3A, the light irradiation intensity at the time of light irradiation is preferably in the range of 0.1 to 4000 mW / cm ² . The light source used when irradiating light is not specifically limited. Examples of the light source include a light source having a sufficient light emission distribution at a wavelength of 420 nm or less. Specific examples of the light source include, for example, a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a chemical lamp, a black light lamp, a microwave excitation mercury lamp, and a metal halide lamp.

  Further, in order to make the anisotropic conductive material layer 3A B-stage, heat is applied to the anisotropic conductive material layer 3A to advance the curing, and the anisotropic conductive material layer 3A is made B-stage. Good.

  The heating temperature when the anisotropic conductive material layer 3A is B-staged by application of heat is preferably 80 ° C. or higher, more preferably 100 ° C. or higher, preferably 200 ° C. or lower, more preferably 160 ° C. or lower. .

  In addition, the anisotropic conductive material layer 3B that has been previously B-staged without applying the B-stage to the anisotropic conductive material layer 3A by irradiating light or applying heat on the upper surface 2a of the first connection target member 2. May be arranged on the upper surface 2 a of the first connection target member 2. Furthermore, an anisotropic conductive film may be disposed on the upper surface 2a of the first connection target member 2.

  Next, as shown in FIG. 2C, the second connection target member 4 is laminated on the upper surface 3a of the B-staged anisotropic conductive material layer 3B. The second connection target member 4 is laminated so that the electrode 2b on the upper surface 2a of the first connection target member 2 and the electrode 4b on the lower surface 4a of the second connection target member 4 face each other. Thus, the laminated body 11 of the 1st connection object member 2, the anisotropic conductive material layer 3B, and the 2nd connection object member 4 is obtained.

  Thereafter, the laminate 11 shown in FIG. The minimum melt viscosity η1 at 60 to 100 ° C. of the anisotropic conductive material layer 3B (the anisotropic conductive material layer 3B immediately before temporary pressure bonding) in the laminate 11 before temporary pressure bonding is 3000 Pa · s or more and 20000 Pa ·. s or less. When the minimum melt viscosity η1 is not less than the above lower limit and not more than the above upper limit, it is possible to suppress the occurrence of misalignment between the first and second connection target members 2 and 4 at the time of temporary pressure bonding and final pressure bonding after temporary pressure bonding. can do. For this reason, the position shift of the electrode 2b of the 1st connection object member 2 and the electrode 4b of the 2nd connection object member 4 can be suppressed. For this reason, in the connection structure 1 obtained, the conduction | electrical_connection reliability between electrode 2b, 4b can be improved. From the viewpoint of further suppressing displacement between the electrodes of the first and second connection target members, the minimum melt viscosity η1 is preferably 6000 Pa · s or more, and preferably 15000 Pa · s or less.

  The minimum melt viscosity η1 is measured by heating the anisotropic conductive material layer from 60 ° C. to 100 ° C. at a heating rate of 5 ° C./min under the condition of a frequency of 1 Hz. The said minimum melt viscosity (eta) 1 shows the viscosity which showed the lowest value in the whole range of 60-100 degreeC.

  Viscosity ratio (η2) of viscosity η2 (Pa · s) at 80 ° C. and frequency 1 Hz of anisotropic conductive material layer 3B in laminate 11 before temporary pressure bonding to viscosity η3 (Pa · s) at 80 ° C. and frequency 10 Hz / Η3) is preferably 1.5 or more, and preferably 6 or less. In this case, not only the positional deviation between the electrodes of the first and second connection target members can be further suppressed, but also the movement of the conductive particles can be suppressed. For this reason, electroconductive particle can be arrange | positioned still more accurately between electrodes, and the conduction | electrical_connection reliability between electrodes in the connection structure obtained can be improved further. The viscosity ratio (η2 / η3) is preferably 3 or more, and preferably 5 or less from the viewpoint of further suppressing the movement of the conductive particles during temporary pressure bonding.

  Further, from the viewpoint of improving the dispensing property at the time of applying the paste, the viscosity η4 (Pa · s) of 25 ° C. and 10 Hz of the anisotropic conductive material layer 3B in the laminated body 11 before the temporary pressing is 25 ° C. and 10 Hz. The viscosity ratio (η4 / η5) to the viscosity η5 (Pa · s) is preferably 1.1 or more, and preferably 1.5 or less.

  The heating temperature (temporary pressure bonding temperature) during temporary pressure bonding is preferably 60 ° C. or higher, more preferably 70 ° C. or higher, preferably 100 ° C. or lower, more preferably 90 ° C. or lower. Since the temporary pressure bonding temperature is generally 60 ° C. or higher and 100 ° C. or lower, the measurement temperature range of the minimum melt viscosity η 1 is 60 to 100 ° C.

  After the temporary pressure bonding, the anisotropic conductive material layer 3B is further cured by applying heat to the anisotropic conductive material layer 3B, and the temporarily bonded laminated body 11 is finally pressure bonded, A certain connection part 3 is formed.

  The heating temperature at the time of curing the anisotropic conductive material layer 3B, that is, the heating temperature at the time of final pressure bonding (final pressure bonding temperature) is preferably 160 or more, more preferably 170 ° C. or more, preferably 250 ° C. or less. Preferably it is 200 degrees C or less.

  It is preferable to apply pressure when the anisotropic conductive material layer 3B is cured. By compressing the conductive particles 5 with the electrodes 2b and 4b by pressurization, the contact area between the electrodes 2b and 4b and the conductive particles 5 can be increased. For this reason, conduction reliability can be improved.

  By curing the anisotropic conductive material layer 3 </ b> B, the first connection target member 2 and the second connection target member 4 are connected via the connection portion 3. Further, the electrode 2 b and the electrode 4 b are electrically connected through the conductive particles 5. In this way, the connection structure 1 shown in FIG. 1 can be obtained. In this embodiment, since photocuring and thermosetting are used together, the anisotropic conductive material can be cured in a short time.

  In the method for manufacturing a connection structure according to the present invention, the anisotropic conductive material layer is preferably formed of an anisotropic conductive paste. Furthermore, in the manufacturing method of the connection structure according to the present invention, the anisotropic conductive material layer in the laminated body before temporary pressure bonding is an anisotropic conductive material layer in which the anisotropic conductive paste is B-staged. Preferably there is. Moreover, in the manufacturing method of the connection structure which concerns on this invention, in the process of arrange | positioning the said anisotropic conductive material layer, on a 1st connection object member which has an electrode on the upper surface, a thermosetting compound, a hardening | curing agent, and electroconductivity are carried out. An anisotropic conductive material layer formed of the anisotropic conductive paste is obtained by laminating an anisotropic conductive paste containing conductive particles and applying light or heat to the anisotropic conductive paste. It is preferable to arrange.

  The anisotropic conductive material is a paste-like or film-like anisotropic conductive material, and is preferably a paste-like anisotropic conductive material. The paste-like anisotropic conductive material is an anisotropic conductive paste. The film-like anisotropic conductive material is an anisotropic conductive film. When the anisotropic conductive material is an anisotropic conductive film, a film that does not include conductive particles may be laminated on the anisotropic conductive film that includes the conductive particles.

  The connection structure manufacturing method according to the present invention includes, for example, a connection between a flexible printed circuit board and a glass substrate (FOG (Film on Glass)), a connection between a semiconductor chip and a flexible printed circuit board (COF (Chip on Film)), Or it can use for the connection (COG (Chip on Glass)) etc. of a semiconductor chip and a glass substrate. Especially, the manufacturing method of the secondary structure which concerns on this invention is suitable for a COG use. In the manufacturing method of the connection structure according to the present invention, it is preferable to use a semiconductor chip and a glass substrate as the first connection target member and the second connection target member.

  In COG applications, in particular, it is often difficult to reliably connect the electrodes of the semiconductor chip and the glass substrate with conductive particles of an anisotropic conductive material. For example, in the case of COG use, the distance between adjacent electrodes of a semiconductor chip and the distance between adjacent electrodes of a glass substrate may be about 10 to 20 μm, and fine wiring is often formed. Even if fine wiring is formed, the manufacturing method of the connection structure according to the present invention can suppress misalignment between the electrodes, so that the electrodes between the semiconductor chip and the glass substrate can be connected with high accuracy. , Conduction reliability can be improved.

  As a method of setting the minimum melt viscosity η1 to the lower limit or more and the upper limit or less, the anisotropic conductive material layer 3A is allowed to progress by irradiating light or applying heat to the anisotropic conductive material layer 3A. When the B-stage is made into a B-stage, the anisotropic conductive material layer 3A is made into a B-stage so that the viscosity of the B-staged anisotropic conductive material layer 3B is 1000 Pa · s or more and 40000 Pa · s or less. Is mentioned. Examples of a method for setting the viscosity ratio (η2 / η3) to the above lower limit or more and the upper limit or less include a method of adding a surface-treated filler and a method of using a thermosetting agent that partially reacts at 100 ° C. or less. . Examples of a method for setting the viscosity ratio (η4 / η5) to the above lower limit or more and the upper limit or less include a method of adding a filler.

  The anisotropic conductive material includes a thermosetting compound, a thermosetting agent, and conductive particles. The anisotropic conductive material preferably includes a thermosetting compound, a thermosetting agent, a photocurable compound, a photocuring initiator, and conductive particles. Hereinafter, the detail of each component contained in the said anisotropic conductive material is demonstrated.

(Thermosetting compound)
Examples of the thermosetting compound include epoxy compounds, episulfide compounds, (meth) acrylic compounds, phenolic compounds, amino compounds, unsaturated polyester compounds, polyurethane compounds, silicone compounds, and polyimide compounds. As for the said thermosetting compound, only 1 type may be used and 2 or more types may be used together.

  From the viewpoint of easily controlling the curing of the anisotropic conductive material or further improving the conduction reliability of the connection structure, the thermosetting compound is a thermosetting compound having an epoxy group or a thiirane group. It is preferable that The compound having an epoxy group is an epoxy compound. The compound having a thiirane group is an episulfide compound. From the viewpoint of allowing thermosetting to proceed more rapidly, the thermosetting compound is preferably an episulfide compound.

  Since the episulfide compound has a thiirane group instead of an epoxy group, it can be cured quickly at a low temperature. That is, the episulfide compound having a thiirane group can be cured at a lower temperature derived from the thiirane group as compared with the epoxy compound having an epoxy group.

[Photocurable compound]
The anisotropic conductive material may contain a photocurable compound so as to be cured by light irradiation. By photoirradiation, the photocurable compound can be semi-cured to reduce the fluidity of the curable compound.

  It does not specifically limit as said photocurable compound, (meth) acrylic resin, cyclic ether group containing resin, etc. are mentioned.

  The photocurable compound is preferably a photocurable compound having a (meth) acryloyl group. The photocurable compound having the (meth) acryloyl group has no epoxy group and thiirane group, and has a (meth) acryloyl group, and has an epoxy group or thiirane group, and ( The photocurable compound which has a (meth) acryloyl group is mentioned.

  The photocurable compound having the (meth) acryloyl group is obtained by reacting (meth) acrylic acid with a compound having a hydroxyl group, and reacting (meth) acrylic acid with an epoxy compound. Epoxy (meth) acrylate or urethane (meth) acrylate obtained by reacting an isocyanate with a (meth) acrylic acid derivative having a hydroxyl group is preferably used. The “(meth) acryloyl group” refers to an acryloyl group and a methacryloyl group. The “(meth) acryl” refers to acryl and methacryl. The “(meth) acrylate” refers to acrylate and methacrylate.

  The ester compound obtained by making the said (meth) acrylic acid and the compound which has a hydroxyl group react is not specifically limited. As the ester compound, any of a monofunctional ester compound, a bifunctional ester compound, and a trifunctional or higher functional ester compound can be used.

  The photocurable compound having the epoxy group or thiirane group and having a (meth) acryloyl group is a part of the epoxy group or part of thiirane of the compound having two or more epoxy groups or two or more thiirane groups. It is preferable that it is a photocurable compound obtained by converting a group into a (meth) acryloyl group. Such a photocurable compound is a partially (meth) acrylated epoxy compound or a partially (meth) acrylated episulfide compound.

  The photocurable compound is preferably a reaction product of a compound having two or more epoxy groups or two or more thiirane groups and (meth) acrylic acid. This reaction product is obtained by reacting a compound having two or more epoxy groups or two or more thiirane groups with (meth) acrylic acid in the presence of a basic catalyst according to a conventional method. It is preferable that 20% or more of the epoxy group or thiirane group is converted (converted) to a (meth) acryloyl group. The conversion is more preferably 30% or more, preferably 80% or less, more preferably 70% or less. Most preferably, 40% or more and 60% or less of the epoxy group or thiirane group is converted to a (meth) acryloyl group.

  Examples of the partially (meth) acrylated epoxy compound include bisphenol type epoxy (meth) acrylate, cresol novolac type epoxy (meth) acrylate, carboxylic acid anhydride-modified epoxy (meth) acrylate, and phenol novolac type epoxy (meth) acrylate. Is mentioned.

  Even if it uses the modified phenoxy resin which converted some epoxy groups or some thiirane groups of the phenoxy resin which has two or more epoxy groups or two or more thiirane groups into a (meth) acryloyl group as a photocurable compound. Good. That is, a modified phenoxy resin having an epoxy group or thiirane group and a (meth) acryloyl group may be used.

  Further, the photocurable compound may be a crosslinkable compound or a non-crosslinkable compound.

  When a photocurable compound and a thermosetting compound are used in combination, the blending ratio of the photocurable compound and the thermosetting compound is appropriately adjusted according to the type of the photocurable compound and the thermosetting compound. The When using a photocurable compound and a thermosetting compound together, the anisotropic conductive material contains the photocurable compound and the thermosetting compound in a weight ratio of 1:99 to 90:10. Is preferably included at 5:95 to 60:40, more preferably 10:90 to 40:60.

(Thermosetting agent)
The said thermosetting agent is not specifically limited. A conventionally known thermosetting agent can be used as the thermosetting agent. Examples of the thermosetting agent include imidazole curing agents, amine curing agents, phenol curing agents, polythiol curing agents, and acid anhydrides. As for the said thermosetting agent, only 1 type may be used and 2 or more types may be used together.

  Since the anisotropic conductive material can be cured more rapidly at a low temperature, the thermosetting agent is preferably an imidazole curing agent, a polythiol curing agent, or an amine curing agent. In addition, a latent curing agent is preferable because the storage stability of the anisotropic conductive material can be improved. The latent curing agent is preferably a latent imidazole curing agent, a latent polythiol curing agent or a latent amine curing agent. The thermosetting agent may be coated with a polymer material such as polyurethane resin or polyester resin.

  From the viewpoint of further suppressing the displacement between the electrodes of the first and second connection target members after the temporary pressure bonding, the thermosetting start temperature of the thermosetting agent is preferably 70 ° C. or higher, more preferably 80 ° C. As mentioned above, Preferably it is 100 degrees C or less, More preferably, it is 90 degrees C or less. Examples of the thermosetting agent satisfying such a thermosetting start temperature include an imidazole curing agent, an amine curing agent, and a polythiol curing agent, and at least one of these is preferably used.

  In the present specification, the thermosetting start temperature means a temperature at which an exothermic peak rises in differential scanning calorimetry (DSC).

  The content of the thermosetting agent is not particularly limited. The content of the thermosetting agent is preferably 5 parts by weight or more, more preferably 10 parts by weight or more, preferably 40 parts by weight or less, more preferably 30 parts by weight or less with respect to 100 parts by weight of the thermosetting compound. More preferably, it is 20 parts by weight or less. When the content of the thermosetting agent is not less than the above lower limit and not more than the above upper limit, the anisotropic conductive material can be sufficiently thermoset. Furthermore, when the content of the thermosetting agent is not less than the above lower limit and not more than the above upper limit, the viscosity ratio (η2 / η3) can be easily made not less than the above lower limit and not more than the above upper limit.

(Photocuring initiator)
The photocuring initiator is not particularly limited. A conventionally known photocuring initiator can be used as the photocuring initiator. As for the said photocuring initiator, only 1 type may be used and 2 or more types may be used together.

  The photocuring initiator is not particularly limited, and examples thereof include acetophenone photocuring initiator, benzophenone photocuring initiator, thioxanthone, ketal photocuring initiator, halogenated ketone, acyl phosphinoxide, and acyl phosphonate. .

  Specific examples of the acetophenone photocuring initiator include 4- (2-hydroxyethoxy) phenyl (2-hydroxy-2-propyl) ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, methoxy Examples include acetophenone, 2,2-dimethoxy-1,2-diphenylethane-1-one, and 2-hydroxy-2-cyclohexylacetophenone. Specific examples of the ketal photocuring initiator include benzyldimethyl ketal.

  The content of the photocuring initiator is not particularly limited. The content of the photocuring initiator is preferably 0.1 parts by weight or more, more preferably 0.2 parts by weight or more, preferably 2 parts by weight or less, more preferably 100 parts by weight of the photocurable compound. Is 1 part by weight or less. When the content of the photocuring initiator is not less than the above lower limit and not more than the above upper limit, the anisotropic conductive material can be appropriately photocured. By irradiating the anisotropic conductive material with light to form a B stage, the flow of the anisotropic conductive material can be suppressed.

(Conductive particles)
The conductive particles contained in the anisotropic conductive material electrically connect the electrodes of the first and second connection target members. The conductive particles are not particularly limited as long as they are conductive particles. The surface of the conductive layer of the conductive particles may be covered with an insulating layer. In this case, the insulating layer between the conductive layer and the electrode is excluded when the connection target member is connected. Examples of the conductive particles include conductive particles whose surfaces are covered with a metal layer, such as organic particles, inorganic particles, organic-inorganic hybrid particles, or metal particles, or metal particles that are substantially composed only of metal. It is done. The metal layer is not particularly limited. Examples of the metal layer include a gold layer, a silver layer, a copper layer, a nickel layer, a palladium layer, or a metal layer containing tin.

  From the viewpoint of further enhancing the conduction reliability between the electrodes, the conductive particles preferably include resin particles and a conductive layer provided on the surface of the resin particles.

  The average particle diameter of the conductive particles is preferably 0.5 μm or more, more preferably 1 μm or more, preferably 100 μm or less, more preferably 20 μm or less, and even more preferably 15 μm or less.

  The “average particle diameter” of the conductive particles indicates the number average particle diameter. The average particle diameter of the conductive particles can be obtained by observing 50 arbitrary conductive particles with an electron microscope or an optical microscope and calculating an average value.

  The content of the conductive particles is not particularly limited. In 100% by weight of the anisotropic conductive material, the content of the conductive particles is preferably 0.1% by weight or more, more preferably 0.5% by weight or more, preferably 20% by weight or less, more preferably 15% by weight. % Or less. A conductive particle can be easily arrange | positioned between the upper and lower electrodes which should be connected as content of the said electroconductive particle is more than the said minimum and below the said upper limit. Furthermore, it becomes difficult to electrically connect adjacent electrodes that should not be connected via a plurality of conductive particles. That is, a short circuit between adjacent electrodes can be further prevented.

(Filler)
The anisotropic conductive material preferably contains a filler. By using the filler, latent heat expansion of the cured product of the anisotropic conductive material can be suppressed. Specific examples of the filler include silica, aluminum nitride, and alumina. As for a filler, only 1 type may be used and 2 or more types may be used together.

  In order to make the minimum melt viscosity η1 above the lower limit and below the upper limit, the filler is preferably surface-treated with a functional group. Examples of the functional group include an epoxy group, a hydroxyl group, and an alkoxy group.

  In order to make the viscosity ratio (η2 / η3) above the lower limit and below the upper limit, the surface-treated filler is preferably 5 parts by weight or more, preferably 50 parts by weight with respect to 100 parts by weight of the total amount of the curable compound. Or less.

(Other ingredients)
The anisotropic conductive material preferably further contains a curing accelerator. By using a curing accelerator, the curing rate can be further increased. As for a hardening accelerator, only 1 type may be used and 2 or more types may be used together.

  Specific examples of the curing accelerator include imidazole curing accelerators and amine curing accelerators. Of these, imidazole curing accelerators are preferred. In addition, an imidazole hardening accelerator or an amine hardening accelerator can be used also as an imidazole hardening agent or an amine hardening agent.

  The anisotropic conductive material may contain a solvent. By using the solvent, the viscosity of the anisotropic conductive material can be easily adjusted. Examples of the solvent include ethyl acetate, methyl cellosolve, toluene, acetone, methyl ethyl ketone, cyclohexane, n-hexane, tetrahydrofuran, and diethyl ether.

  Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples. The present invention is not limited only to the following examples.

Example 1
(1) Preparation of episulfide compound-containing mixture In a 2 L vessel equipped with a stirrer, a cooler, and a thermometer, ethanol 250 mL and pure water 2
Add 50 mL and 20 g of potassium thiocyanate to dissolve the potassium thiocyanate,
A first solution was prepared. Thereafter, the temperature in the container was kept in the range of 20 to 25 ° C. Next, while stirring the first solution in the container maintained at 20 to 25 ° C.,
160 g of resorcinol diglycidyl ether was added dropwise at a rate of 5 mL / min. After dripping
The mixture was further stirred for 30 minutes to obtain an epoxy compound-containing mixed solution.

Next, a second solution in which 20 g of potassium thiocyanate was dissolved in a solution containing 100 mL of pure water and 100 mL of ethanol was prepared. The obtained second solution was added to the obtained epoxy group-containing mixed solution at a rate of 5 mL / min, and then stirred for 30 minutes. After stirring, pure water 100m
A second solution in which 20 g of potassium thiocyanate is dissolved in a solution containing L and 100 mL of ethanol is further prepared, and the second solution is further added to the container at a rate of 5 mL / min.
Stir for 0 min. Thereafter, the temperature in the container was cooled to 10 ° C., and stirred for 2 hours to be reacted.
Next, 100 mL of saturated saline was added to the container and stirred for 10 minutes. After stirring, 300 mL of toluene was further added to the container and stirred for 10 minutes. Thereafter, the solution in the container was transferred to a separating funnel and allowed to stand for 2 hours to separate the solution. The lower solution in the separatory funnel was discharged, and the supernatant was taken out. 100 mL of toluene was added to the removed supernatant, stirred, and allowed to stand for 2 hours. Further, 100 mL of toluene was further added, stirred and allowed to stand for 2 hours.

Next, 50 g of magnesium sulfate was added to the supernatant liquid to which toluene was added and stirred for 5 minutes. After stirring, magnesium sulfate was removed with a filter paper to separate the solution. The remaining solvent was removed by drying the separated solution under reduced pressure at 80 ° C. using a vacuum dryer. In this way, an episulfide compound-containing mixture was obtained.

1H-NMR of the resulting episulfide compound-containing mixture using chloroform as a solvent
Was measured. As a result, the signal in the region of 6.5 to 7.5 ppm indicating the presence of the epoxy group decreased, and the signal appeared in the region of 2.0 to 3.0 ppm indicating the presence of the episulfide group. This confirmed that some epoxy groups of resorcinol diglycidyl ether were converted into episulfide groups. Moreover, from the integral value of the measurement result of 1H-NMR, the episulfide compound-containing mixture contains 70% by weight of resorcinol diglycidyl ether and 30% by weight of the episulfide compound having a structure represented by the following formula (1B). It was confirmed.

(2) Production of anisotropic conductive paste 30 parts by weight of the resulting episulfide compound-containing mixture and amine adduct (“Amure PN-23J” manufactured by Ajinomoto Fine Techno Co., curing start temperature 75 ° C.) 5 weight Part, 5 parts by weight of an epoxy acrylate (“EBECRYL 3702” manufactured by Daicel-Cytec) that is a photocurable compound, and an acylphosphine oxide compound (“DAROCUR TPO” manufactured by Ciba Japan) that is a photocuring initiator. 1 part by weight, 1 part by weight of 2-ethyl-4-methylimidazole that is a curing accelerator, and 25 parts by weight of silica that is a filler (“SE-2030” manufactured by Admatechs, average particle diameter of 0.25 μm), Silica filler having an epoxy group on the surface ("SE-4050-SEE" manufactured by Admatechs, average (Particle diameter 1 μm) and 15 parts by weight, and further, conductive particles having an average particle diameter of 3 μm were added so that the content in 100% by weight of the composition was 10% by weight, and then a planetary stirrer was used. The formulation was obtained by stirring for 5 minutes at 2000 rpm.

  The conductive particles used are conductive particles having a metal layer in which a nickel plating layer is formed on the surface of divinylbenzene resin particles and a gold plating layer is formed on the surface of the nickel plating layer. is there.

  The obtained blend was filtered using a nylon filter paper (pore diameter: 10 μm) to obtain an anisotropic conductive paste having a conductive particle content of 10% by weight.

(3) Preparation of connection structure The transparent glass substrate (1st connection object member, length 24mm x width 52mm) in which the ITO electrode pattern whose L / S is 20 micrometers / 20 micrometers was formed in the upper surface was prepared. Further, a semiconductor chip (second connection target member, 1 mm long × 18 mm wide) having a copper electrode pattern with L / S of 20 μm / 20 μm formed on the lower surface was prepared.

On the transparent glass substrate, the obtained anisotropic conductive paste was applied to a thickness of 20 μm to form an anisotropic conductive paste layer. Next, the anisotropic conductive paste layer was irradiated with ultraviolet light of 420 nm so that the light irradiation intensity was 50 mW / cm ^2, and the anisotropic conductive paste layer was semi-cured by photopolymerization to form a B stage. Next, the semiconductor chip was laminated on the B-staged anisotropic conductive paste layer at 80 ° C. (temporary pressure bonding temperature) so that the electrodes face each other. After provisional pressure bonding, the head is placed on the upper surface of the semiconductor chip while adjusting the temperature of the head so that the temperature of the anisotropic conductive paste layer is 185 ° C. (final pressure bonding temperature), and cured by applying a pressure of 3 MPa, A connection structure was obtained.

(Example 2)
An anisotropic conductive paste was obtained in the same manner as in Example 1 except that the thermosetting compound was changed to a polyfunctional acrylate (“DPCA-120” manufactured by Nippon Kayaku Co., Ltd.). A connection structure was produced in the same manner as in Example 1 except that the obtained anisotropic conductive paste was used.

(Example 3)
An anisotropic conductive paste was obtained in the same manner as in Example 1 except that the amount of silica filler (average particle size of 0.25 μm) was changed to 8 parts by weight. A connection structure was produced in the same manner as in Example 1 except that the obtained anisotropic conductive paste was used.

Example 4
An anisotropic conductive paste was obtained in the same manner as in Example 1 except that the thermosetting initiator was changed to an amine adduct system (“Amure MY-24” manufactured by Ajinomoto Fine Techno Co., Ltd., 80 ° C. curing start temperature). . A connection structure was produced in the same manner as in Example 1 except that the obtained anisotropic conductive paste was used.

(Example 5)
A connection structure was produced in the same manner as in Example 1 except that the temporary pressure bonding temperature was changed to 65 ° C.

(Example 6)
A connection structure was produced in the same manner as in Example 1 except that the temporary pressure bonding temperature was changed to 95 ° C.

(Example 7)
A connection structure was produced in the same manner as in Example 1 except that the main pressure bonding temperature was changed to 175 ° C.

(Example 8)
A connection structure was produced in the same manner as in Example 1 except that the main pressure bonding temperature was changed to 195 ° C.

(Comparative Example 1)
An anisotropic conductive paste was obtained in the same manner as in Example 1 except that the amount of silica filler (average particle size of 0.25 μm) was changed to 5 parts by weight. A connection structure was produced in the same manner as in Example 1 except that the obtained anisotropic conductive paste was used.

(Comparative Example 2)
An anisotropic conductive paste was obtained in the same manner as in Example 1 except that the amount of silica filler (average particle size of 0.25 μm) was changed to 40 parts by weight. A connection structure was produced in the same manner as in Example 1 except that the obtained anisotropic conductive paste was used.

(Evaluation of Examples 1-8 and Comparative Examples 1-2)
(1) Minimum melt viscosity η1
The minimum melt viscosity η1 of the B-staged anisotropic conductive paste layer before temporary pressure bonding was measured.

  Using a melt viscosity measuring apparatus (“VAR-100” manufactured by Rheologicala Co., Ltd.), the above-mentioned minimum melt viscosity η1 is B before pre-bonding at a temperature increase rate of 5 ° C./min from 60 ° C. to 120 ° C. under the condition of a frequency of 1 Hz It was measured by heating the staged anisotropic conductive paste layer.

(2) Viscosity ratio (η2 / η3) and viscosity ratio (η4 / η5)
Using a melt viscosity measuring device (“VAR-100” manufactured by Rheologicala Co., Ltd.), the viscosity η2 (Pa · s) of 80 at 80 ° C. and a frequency of 1 Hz of the B-staged anisotropic conductive paste layer before temporary pressure bonding is 80. The viscosity ratio (η2 / η3) to the viscosity η3 (Pa · s) at a temperature of 10 ° C. and a frequency of 10 Hz was determined.

  Furthermore, the viscosity η4 (Pa · s) at 25 ° C. and a frequency of 1 Hz of the B-staged anisotropic conductive paste layer before provisional pressure bonding using a melt viscosity measuring device (“VAR-100” manufactured by Rheologicala) The viscosity ratio (η4 / η5) to the viscosity η5 (Pa · s) at 25 ° C. and a frequency of 10 Hz was determined.

(3) Misalignment between electrodes in the first and second connection target members Among the ten connection structures obtained, misalignment between the electrodes of the first and second connection target members has occurred. The case where the positional deviation between the electrodes was less than 0.005 mm was determined as “good”, and the case where the positional deviation between the first and second connection target members was 0.005 mm or more was determined as “bad”.

  From the ratio of the connection structures determined to be good, the positional deviation between the electrodes was evaluated according to the following criteria.

◯: The ratio of connection structures determined to be good in 10 connection structures is 90% or more. ○: The ratio of connection structures determined as good in 10 connection structures is 80% or more. Less than 90% ×: Ratio of connection structures determined to be good among 10 connection structures is less than 80%

(4) Conduction reliability (conductivity test between upper and lower electrodes)
The connection resistance between the upper and lower electrodes of the obtained connection structure was measured by a four-terminal method. The average value of the two connection resistances was calculated. The case where the average value of the connection resistance was 2.0Ω or less was judged as “good”, and the case where the average value of the connection resistance exceeded 2Ω was judged as “bad”.

  The conduction reliability was evaluated according to the following criteria from the proportion of the connection structures determined to be good among the 10 connection structures.

[Judgment criteria for conduction reliability]
◯: The ratio of connection structures determined to be good in 10 connection structures is 90% or more. ○: The ratio of connection structures determined as good in 10 connection structures is 80% or more. Less than 90% ×: Ratio of connection structures determined to be good among 10 connection structures is less than 90%

  The results are shown in Table 1 below.

DESCRIPTION OF SYMBOLS 1 ... Connection structure 2 ... 1st connection object member 2a ... Upper surface 2b ... Electrode 3 ... Connection part 3a ... Upper surface 3A ... Anisotropic conductive material layer 3B ... B-staged anisotropic conductive material layer 4 ... First 2 connection target members 4a ... lower surface 4b ... electrode 5 ... conductive particles 11 ... laminate

Claims (5)

Disposing an anisotropic conductive material layer including a thermosetting compound, a thermosetting agent, and conductive particles on a first connection target member having an electrode on an upper surface;
A second connection target member having an electrode on the lower surface is laminated on the upper surface of the anisotropic conductive material layer, and the first connection target member, the anisotropic conductive material layer, and the second connection target member are stacked. Obtaining a laminate with
A step of temporarily pressing the laminate,
A step of curing the anisotropic conductive material layer and subjecting the laminate, which has been temporarily pressure-bonded, to pressure bonding,
The manufacturing method of the connection structure which makes the minimum melt viscosity in 60-100 degreeC of the said anisotropic conductive material layer in the said laminated body before temporary press-bonding to 3000 Pa.s or more and 20000 Pa.s or less.   The viscosity ratio of the viscosity (Pa · s) at 80 ° C. and a frequency of 1 Hz to the viscosity (Pa · s) at 80 ° C. and a frequency of 10 Hz of the anisotropic conductive material layer in the laminate before temporary pressure bonding is as follows: The manufacturing method of the connection structure according to claim 1, wherein the number is 5 or more and 6 or less. The anisotropic conductive material layer is formed of an anisotropic conductive paste;
3. The connection structure according to claim 1, wherein the anisotropic conductive material layer in the laminate before temporary pressure bonding is an anisotropic conductive material layer in which the anisotropic conductive paste is B-staged. Production method. The anisotropic conductive material layer is formed of an anisotropic conductive paste;
In the step of disposing the anisotropic conductive material layer, an anisotropic conductive paste containing a thermosetting compound, a thermosetting agent, and conductive particles is laminated on the first connection target member having electrodes on the upper surface. The anisotropic conductive material layer formed by the anisotropic conductive paste is disposed by irradiating light or applying heat to the anisotropic conductive paste. The manufacturing method of the connection structure of description.   The anisotropic conductive paste containing a thermosetting compound, a photocurable compound, a thermosetting agent, a photocuring initiator, and conductive particles is used as the anisotropic conductive material. The manufacturing method of the connection structure as described in a term.

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