JP5400545B2 - Anisotropic conductive material, connection structure manufacturing method, and connection structure - Google Patents

Description

  The present invention is an anisotropic conductive material including a plurality of conductive particles. For example, the electrodes of various connection target members such as a flexible printed board, a glass substrate, and a semiconductor chip are electrically connected via conductive particles. The present invention relates to an anisotropic conductive material that can be suitably used for connection, and a connection structure manufacturing method and connection structure using the anisotropic conductive material.

  An anisotropic conductive paste containing conductive particles is used for electrical connection of various connection target members.

  The anisotropic conductive paste 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.

  As an example of the anisotropic conductive paste, the following Patent Document 1 describes an anisotropic conductive material as an epoxy resin, rubber-like polymer particles, a thermally active latent epoxy curing agent, and high softening point polymer particles. An anisotropic conductive paste containing conductive particles is disclosed. For example, when the electrode of the semiconductor chip and the electrode of the glass substrate are electrically connected with the anisotropic conductive material, an anisotropic conductive paste containing conductive particles is applied onto the glass substrate. Next, the semiconductor chips are stacked, and heated and pressurized. As a result, the anisotropic conductive paste is cured, and the electrodes are electrically connected via the conductive particles.

JP 2000-345010 A

  During the connection, the anisotropic conductive paste applied on the glass substrate and the conductive particles contained in the anisotropic conductive paste may flow greatly before curing. For this reason, the conductive particles may not be arranged in a specific region. Furthermore, the conductive particles may not be disposed between the upper and lower electrodes to be connected, or adjacent electrodes that should not be connected may be electrically connected via a plurality of conductive particles. For this reason, the conduction | electrical_connection reliability of the obtained connection structure may be low.

  An object of the present invention is to provide an anisotropic conductive material that can enhance conduction reliability when electrodes of connection target members are electrically connected, and a manufacturing of a connection structure using the anisotropic conductive material. It is to provide a method and a connection structure.

  According to a wide aspect of the present invention, it has an inner layer and an outer layer laminated on one side of the inner layer and the other side opposite to the one side, the inner layer comprising a curable compound and a thermosetting agent. And at least one of photocuring initiator and conductive particles, and the outer layer contains a curable compound and at least one of thermosetting agent and photocuring initiator. A conductive material is provided.

  In a specific aspect of the anisotropic conductive material according to the present invention, the inner layer includes a mixture of a thermosetting compound and a photocurable compound, a thermosetting agent, a photocuring initiator, and conductive particles. Or a photocurable compound, a photocuring initiator, and conductive particles, and the outer layer includes a thermosetting compound and a thermosetting agent.

  In another specific aspect of the anisotropic conductive material according to the present invention, the inner layer comprises a mixture of a thermosetting compound and a photocurable compound, a thermosetting agent, a photocuring initiator, and conductive particles. Including.

  In still another specific aspect of the anisotropic conductive material according to the present invention, the curable compound contained in the inner layer contains a curable compound having a (meth) acryloyl group, and is contained in the outer layer. The curable compound contains a curable compound having at least one of an epoxy group and an episulfide group.

  In another specific aspect of the anisotropic conductive material according to the present invention, the viscosity of the inner layer is higher than the viscosity of the outer layer.

  In still another specific aspect of the anisotropic conductive material according to the present invention, the outer layer covers the inner layer so as to surround the outer peripheral surface of the inner layer.

  In the connection structure according to the present invention, an anisotropic conductive material configured according to the present invention is disposed on the upper surface of the first connection target member, and the outer layer is disposed between the first connection target member and the inner layer. And forming the anisotropic conductive material layer so as to be positioned, and irradiating light or applying heat to the anisotropic conductive material layer to advance the curing of the inner layer, thereby causing the inner layer to move to the B stage. And moving the B-staged inner layer so that the B-staged inner layer approaches the upper surface of the first connection target member, and after moving the B-staged inner layer, A step of further laminating a second connection target member on the upper surface of the anisotropic conductive material layer, curing the B-staged inner layer and the outer layer, and obtaining a connection structure.

  In a specific aspect of the method for manufacturing a connection structure according to the present invention, in the step of moving the inner layer, the B stage is arranged such that the B-staged inner layer contacts the upper surface of the first connection target member. The converted inner layer is moved.

  The connection structure according to the present invention includes a first connection target member, a second connection target member, and a cured product layer connecting the first and second connection target members. The cured product layer is formed by curing the anisotropic conductive material configured according to the present invention.

  An anisotropic conductive material according to the present invention has an inner layer and an outer layer laminated on one side of the inner layer and the other side opposite to the one side, and the inner layer comprises a curable compound, a heat compound, Since the outer layer contains at least one of a curing agent and a photocuring initiator and conductive particles, and the outer layer contains a curable compound and at least one of a thermosetting agent and a photocuring initiator, By irradiation or heating, the inner layer can be selectively cured to suppress the flow of the conductive particles. For example, after the inner layer is cured by light irradiation or heating to suppress the flow of the conductive particles, the outer layer is cured by heating, whereby the conductive particles can be arranged in a specific region.

  Therefore, when the electrodes of the first and second connection target members are electrically connected using the anisotropic conductive material according to the present invention, conduction reliability can be improved. For example, the upper and lower electrodes to be connected can be easily connected with conductive particles, and adjacent electrodes that should not be connected can be prevented from being connected via a plurality of conductive particles.

1A to 1C are a perspective view and a cross-sectional view schematically showing an anisotropic conductive material according to an embodiment of the present invention. FIG. 2 is a partially cutaway front sectional view showing an example of a connection structure using an anisotropic conductive material according to an embodiment of the present invention. 3A to 3C are cross-sectional views for explaining each process for manufacturing the connection structure shown in FIG. FIG. 4 is a partially cutaway longitudinal sectional view showing a state when an anisotropic conductive material is discharged from a dispenser when the connection structure shown in FIG. 2 is manufactured.

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

  FIG. 1A is a perspective view showing an anisotropic conductive material according to an embodiment of the present invention. FIG.1 (b) is sectional drawing which follows the II line | wire of Fig.1 (a). FIG.1 (c) is sectional drawing which follows the II-II line | wire of Fig.1 (a).

  1A to 1C, the anisotropic conductive material 1 is discharged from the tip 31a of the dispenser 31 in the direction of arrow A while moving the dispenser 31 shown in FIG. 1A in the direction of arrow X. The state when the anisotropic conductive material 1 is disposed on the upper surface 22a of the connection target member 22 is shown.

  As shown in FIGS. 1A to 1C, the anisotropic conductive material 1 has an inner layer 2 and an outer layer 3 laminated on the one 2 a side and the other 2 b side of the inner layer 2. The outer layer 3 covers the inner layer 2 so as to surround the outer peripheral surface of the inner layer 2. The outer layer 3 has a cylindrical shape, and the inner layer 2 is disposed in the cylindrical outer layer 3. Each of the inner layer 2 and the outer layer 3 is a paste.

  The inner layer 2 includes a curable compound, at least one of a thermosetting agent and a photocuring initiator, and conductive particles 4. The outer layer 3 contains a curable compound and at least one of a thermosetting agent and a photocuring initiator.

  From the viewpoint of curing the inner layer 2 and the outer layer 3 at different times, the inner layer 2 includes a mixture of a thermosetting compound and a photocurable compound, a thermosetting agent, a photocuring initiator, and conductive particles 4. It is preferable that it contains or contains a photocurable compound, a photocuring initiator, and electroconductive particle, and the outer layer 3 contains a thermosetting compound and a thermosetting agent. After the inner layer 2 is cured by light irradiation to obtain a B-staged inner layer, the B-staged inner layer can be further cured by applying heat. It is more preferable that the mixture of a photoconductive compound and a photocurable compound, a thermosetting agent, a photocuring initiator, and the electroconductive particle 4 are included.

  From the viewpoint of curing the inner layer 2 and the outer layer 3 more easily at different times, the curable compound contained in the inner layer 2 contains a curable compound having a (meth) acryloyl group, and is contained in the outer layer 3. The curable compound is preferably a curable compound having at least one of an epoxy group and an episulfide group. The (meth) acryloyl represents acryloyl or methacryloyl.

  From the viewpoint of further suppressing unintended flow of the conductive particles 4, the viscosity of the inner layer 2 is preferably higher than the viscosity of the outer layer 3. The viscosity at 25 ° C. of the inner layer 2 before curing (hereinafter sometimes abbreviated as viscosity η1) is higher than the viscosity at 25 ° C. of the outer layer 3 before curing (hereinafter sometimes abbreviated as viscosity η2). High is preferred. The viscosity η1 of the inner layer 2 is preferably 30 Pa · s or more higher than the viscosity η2 of the outer layer, and more preferably 50 Pa · s or more. When the relationship between the viscosity η1 and the viscosity η2 is satisfied, unintended flow of the conductive particles 4 can be further suppressed. Furthermore, when the anisotropic conductive material 1 is disposed between the first and second connection target members and bonded, the outer layer 3 disposed between the first and second connection target members and the inner layer 2 is removed. Easy to remove. For this reason, the conduction | electrical_connection reliability of a connection structure can be improved further.

  The preferable lower limit of the viscosity η1 of the inner layer 2 is 50 Pa · s, the more preferable lower limit is 100 Pa · s, the preferable upper limit is 250 Pa · s, and the more preferable upper limit is 200 Pa · s. When the viscosity η1 satisfies the above preferable lower limit and upper limit, unintended flow of the conductive particles 4 can be further suppressed. Furthermore, it becomes difficult for the conductive particles 4 to settle in the inner layer 2 and the dispersibility of the conductive particles 4 can be improved.

  A preferable lower limit of the viscosity η2 of the outer layer 3 is 20 Pa · s, a more preferable lower limit is 50 Pa · s, a preferable upper limit is 200 Pa · s, and a more preferable upper limit is 150 Pa · s. When the viscosity η2 satisfies the preferable lower limit and upper limit, when the inner layer 2 is B-staged, the B-staged inner layer is likely to fall. Further, when the anisotropic conductive material 1 is disposed between the first and second connection target members and bonded, the outer layer 3 disposed between the first and second connection target members and the inner layer 2 is disposed. It can be removed even more easily. Furthermore, components other than the conductive particles 4 between the electrode and the conductive particles 4 can be easily removed, and the contact area between the electrode and the conductive particles 4 can be increased. Furthermore, when the surface of the first connection target member is uneven, the anisotropic conductive material 1 can be sufficiently filled in the uneven surface, and voids are less likely to occur after curing.

  The manufacturing method of the composition for forming the inner layer 2 and the outer layer 3 of the anisotropic conductive material 1 is not particularly limited. Examples of the method for producing the composition include the curable compound, at least one of the thermosetting agent and the photocuring initiator, and the conductive particles and other components added as necessary. And a sufficient production method using a planetary stirrer or the like.

  FIG. 2 is a front sectional view schematically showing an example of a connection structure using the anisotropic conductive material shown in FIGS.

  The connection structure 21 shown in FIG. 2 includes a first connection target member 22, a second connection target member 23, and a cured product layer 24 connecting the first and second connection target members 22 and 23. Is provided. The cured product layer 24 is formed by curing the anisotropic conductive material 1.

  A plurality of electrodes 22 b are provided in a partial region of the upper surface 22 a of the first connection target member 22. A plurality of electrodes 23 b are provided in a partial region of the lower surface 23 a of the second connection target member 23. The electrode 22 b and the electrode 23 b are electrically connected by one or a plurality of conductive particles 4.

  In the connection structure 21, a glass substrate is used as the first connection target member 22, and a semiconductor chip is used as the second connection target member 23. The 1st, 2nd connection object members 22 and 23 are not specifically limited. Specific examples of the first and second connection target members 22 and 23 include electronic components such as semiconductor chips, capacitors, and diodes, and circuit boards such as printed boards, flexible printed boards, and glass boards.

  The connection structure 21 shown in FIG. 2 can be obtained as follows, for example.

  First, the first connection target member 22 having the electrode 22b on the upper surface 22a is prepared. Next, the anisotropic conductive material 1 is discharged onto the upper surface 22a of the first connection target member 22 using the dispenser 31 shown in FIG.

  In FIG. 4, the state at the time of discharging the anisotropic conductive material 1 using the dispenser 31 is shown with a partial notch longitudinal cross-sectional view.

  The dispenser 31 has an outer wall 32 and a partition wall 33 inside the outer wall 32. The outer wall 32 and the partition wall 33 are spaced apart. Each of the outer wall 32 and the partition wall 33 has a cylindrical shape. The region R1 inside the partition wall 33 is a region for discharging the inner layer 2. A region R2 between the outer wall 32 and the partition wall 33 is a region for discharging the outer layer 3. By using such a dispenser 31, the anisotropic conductive material 1 having the inner layer 2 and the outer layer 3 surrounding the outer peripheral surface of the inner layer 2 can be easily discharged.

  As shown in FIGS. 1A to 1C, the anisotropic conductive material 1 discharged from the dispenser 31 is disposed on the upper surface 22 a of the first connection target member 22. On the upper surface 22a of the first connection target member 22, the anisotropic conductive material 1 is disposed from the outer layer 3 laminated on the one 2a side of the inner layer 2. Thus, the outer layer 3, the inner layer 2, and the outer layer 3 are laminated in this order on the upper surface 22a of the first connection target member 22. Therefore, the outer layer 3 is located between the first connection target member 22 and the inner layer 2. In this way, the anisotropic conductive material layer 1 </ b> A is formed on the upper surface 22 a of the first connection target member 22. At this time, it is preferable that one or a plurality of conductive particles 4 be disposed above the electrode 22b.

  Next, as shown in FIG. 3A corresponding to FIG. 1B, the curing of the inner layer 2 is advanced by irradiating light or applying heat to the anisotropic conductive material layer 1A. . Curing of the inner layer 2 is advanced to make the inner layer 2 into a B-stage. The B-stage inner layer 2A is formed on the upper surface 22a of the first connection target member 22. At this time, it is preferable that the outer layer 3 is not cured and is not B-staged. Therefore, the outer layer 3 is preferably less photocured than the inner layer 2, and more preferably not photocured. By selectively changing the means for curing the curable compounds of the inner layer 2 and the outer layer 3 or by varying the curing rate of the inner layer 2 and the outer layer 3, only the inner layer 2 is selectively B-staged. Can do.

  In the B-staged inner layer 2A, the flow of the conductive particles 4 is suppressed as compared with the inner layer 2 before being B-staged. For this reason, it becomes easy to arrange the conductive particles 4 between the electrodes 22b and 23b.

  When the hardening of the inner layer 2 is advanced to make the inner layer 2 into a B-stage, the viscosity of the B-staged inner layer 2A (hereinafter sometimes abbreviated as η11) is within a range of 2000 to 3500 Pa · s. As shown, the inner layer 2A is preferably B-staged. By setting the viscosity η11 within the above range, the flow of the conductive particles 4 can be sufficiently suppressed. For this reason, it becomes easy to arrange the conductive particles 4 between the electrodes 22b and 23b.

  From the viewpoint of further suppressing the flow of the conductive particles 4, the preferable lower limit of the viscosity η11 is 2250 Pa · s, and the preferable upper limit is 3250 Pa · s. The preferable lower limit of the measurement temperature of the viscosity η11 is 20 ° C., and the preferable upper limit is 30 ° C. The measurement temperature of the viscosity η11 is particularly preferably 25 ° C.

  It is preferable to irradiate or apply heat to the anisotropic conductive material layer 1 </ b> A while disposing the anisotropic conductive material layer 1 on the upper surface 22 a of the first connection target member 22. Furthermore, the anisotropic conductive material layer 1 </ b> A may be irradiated with light or given heat simultaneously with or immediately after the anisotropic conductive material 1 is arranged on the upper surface 22 a of the first connection target member 22. preferable. When the arrangement of the anisotropic conductive material 1 and the irradiation of light or application of heat are performed as described above, the flow of the conductive particles 4 can be further suppressed. For this reason, the conduction | electrical_connection reliability of the obtained connection structure 21 can be improved further. The time from the placement of the anisotropic conductive material 1 on the upper surface 22a of the first connection target member 22 to the application of light or application of heat is preferably in the range of 0 to 3 seconds. More preferably, it is within the range of 2 seconds.

When the inner layer 2 is B-staged by light irradiation, the light irradiation intensity for appropriately proceeding curing of the inner layer 2 is, for example, about 0.1 to 100 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.

  When the inner layer 2 is B-staged by application of heat, the preferable lower limit of the heating temperature for appropriately progressing the curing of the inner layer 2 is 100 ° C., the preferable upper limit is 150 ° C., and the more preferable upper limit is 130 ° C.

  Next, as shown in FIG. 3B, the B-stage inner layer 2 </ b> A is moved so as to approach the upper surface 2 a of the first connection target member 22. By making the inner layer 2 B-staged, the B-staged inner layer 2 A can be moved so as to approach the upper surface 2 a of the first connection target member 22. That is, the B-staged inner layer 2A gradually descends so as to move toward the one 2a side. It is preferable to move the B-stage inner layer 2 </ b> A so as to contact the upper surface 22 a of the first connection target member 22. The leaving time for moving the B-staged inner layer 2A so as to approach the upper surface 2a of the first connection target member 22 is preferably 30 seconds or more, more preferably 60 seconds or more, and 120 It is preferably 2 seconds or less, and more preferably 90 seconds or less.

  Next, as shown in FIG. 3C, after the B-staged inner layer 2A has moved, the second connection target member 23 is placed on the upper surface 1a of the anisotropic conductive material layer 1A in the direction of arrow B. Laminate. The second connection target member 22 is laminated so that the electrode 22b on the upper surface 22a of the first connection target member 2 and the electrode 23b on the lower surface 23a of the second connection target member 23 face each other.

  Further, when the second connection target member 23 is laminated, the anisotropic conductive material layer 1A is further cured by irradiating light or applying heat to the anisotropic conductive material layer 1A, and the cured product layer 24 Form. That is, the B-staged inner layer 2A and the outer layer 3 are cured to form a cured product layer 24. However, before the second connection target member 23 is laminated, the anisotropic conductive material layer 1A may be irradiated with light or given heat. Further, after the second connection target member 22 is laminated, the anisotropic conductive material layer 1A may be irradiated with light or given heat.

When the inner layer 2A and the outer layer 3 that have been B-staged by light irradiation are cured, the light irradiation intensity for sufficient curing is, for example, about 0.1 to 100 mW / cm ² .

  When the inner layer 2A and the outer layer 3 that have been B-staged by applying heat are cured, the preferable lower limit of the heating temperature for sufficient curing is 160 ° C, the preferable upper limit is 250 ° C, and the more preferable upper limit is 200 ° C. is there.

  Pressure is applied when the anisotropic conductive material layer 1A is cured. By applying pressure, components other than the conductive particles 4 contained in the B-staged inner layer 2A and outer layer 3 are removed, and the conductive particles 4 are compressed by the electrodes 22b and 23b. Thus, the electrode 22b and the electrode 23b can be electrically connected by the conductive particles 4. Furthermore, the contact area between the electrodes 22b and 23b and the conductive particles 4 can be increased. For this reason, conduction reliability can be improved.

  By curing the B-staged inner layer 2 </ b> A and the outer layer 3, the first connection target member 22 and the second connection target member 23 are connected via the cured product layer 4. Further, the electrode 22b and the electrode 24b are electrically connected via the conductive particles 4. In this way, the connection structure 21 shown in FIG. 2 can be obtained.

  When obtaining the connection structure 21, it is preferable to apply heat to the anisotropic conductive material layer 1 </ b> A after the anisotropic conductive material layer 1 </ b> A is irradiated with light to form the B-staged inner layer 2 </ b> A. The anisotropic conductive material can be cured in a short time by the combined use of photocuring and heat curing.

  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 connection structure concerning the present invention is suitable for COG use. The method for manufacturing a connection structure according to the present invention is suitably used for connection between a semiconductor chip and a glass substrate. However, the use of the method for manufacturing a connection structure according to the present invention is not limited to the above-described application.

  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 connection structure body manufacturing method according to the present invention can connect the electrodes of the semiconductor chip and the glass substrate with high accuracy, and can improve conduction reliability.

  Hereinafter, the detail of each component contained in the said anisotropic conductive material is demonstrated.

(Curable compound)
A conventionally known curable compound can be used as the curable compound, and is not particularly limited. As for the said sclerosing | hardenable compound, only 1 type may be used and 2 or more types may be used together.

  Examples of the curable compound include light and thermosetting compounds, photocurable compounds, and thermosetting compounds. The light and thermosetting compounds have photocuring properties and thermosetting properties. The said photocurable compound has photocurability, for example, and does not have thermosetting. The said thermosetting compound does not have photocurability, for example, and has thermosetting.

  The mixture of the thermosetting compound and the photocurable compound includes not only the case where the thermosetting compound and the photocurable compound are used in combination, but also the light and the thermosetting compound.

  The curable compound is not particularly limited. Examples of the curable compound include epoxy compounds, episulfide compounds, (meth) acrylic compounds, phenolic compounds, amino compounds, unsaturated polyester compounds, polyurethane compounds, silicone compounds, and polyimide compounds. The (meth) acryl means acryl or methacryl.

[Thermosetting compound]
From the viewpoint of easily controlling the curing of the anisotropic conductive material and further enhancing the conduction reliability of the connection structure, the thermosetting compound is an epoxy compound or an episulfide compound (thiirane group-containing compound). It is preferable that at least one of them is included, and it is more preferable that an episulfide compound is included.

  The episulfide compound preferably has a structure represented by the following formula (1) or (2).

  In the above formula (1), R1 and R2 each represent an alkylene group having 1 to 5 carbon atoms, 2 to 4 groups out of 4 groups of R3, R4, R5 and R6 represent hydrogen, and R3 , R4, R5 and R6 which are not hydrogen represent a group represented by the following formula (3).

  All four groups of R3, R4, R5 and R6 in the above formula (1) may be hydrogen. One or two of the four groups of R3, R4, R5 and R6 are groups represented by the following formula (3), and among the four groups of R3, R4, R5 and R6 The group that is not a group represented by the following formula (3) may be hydrogen.

  In the above formula (2), R51 and R52 each represent an alkylene group having 1 to 5 carbon atoms, and 4 to 6 groups out of 6 groups of R53, R54, R55, R56, R57 and R58 are hydrogen. The group which is not hydrogen among R53, R54, R55, R56, R57 and R58 represents a group represented by the following formula (4).

  All of the six groups of R53, R54, R55, R56, R57 and R58 in the above formula (2) may be hydrogen. One or two of the six groups of R53, R54, R55, R56, R57 and R58 are groups represented by the following formula (4), and R53, R54, R55, R56, R57 and R58. Of these, the group that is not a group represented by the following formula (4) may be hydrogen.

  In said formula (3), R7 represents a C1-C5 alkylene group.

  In said formula (4), R59 represents a C1-C5 alkylene group.

  The episulfide compound having a structure represented by the above formula (1) or (2) has at least two thiirane groups (episulfide groups). In addition, a group having a thiirane group is bonded to a benzene ring or a naphthalene ring. Since it has such a structure, the anisotropic conductive material can be rapidly cured at a low temperature by heating the anisotropic conductive material. In this specification, low temperature means a temperature of 200 ° C. or lower.

  The episulfide compound having a structure represented by the above formula (1) or (2) has higher reactivity than a compound in which the thiirane group in the above formula (1) or (2) is an epoxy group. This is because a thiirane group is easier to open a ring and has higher reactivity than an epoxy group. Since the episulfide compound having the structure represented by the above formula (1) or (2) has high reactivity, the anisotropic conductive material can be rapidly cured at a low temperature.

  R1 and R2 in the formula (1), R51 and R52 in the formula (2), R7 in the formula (3), and R59 in the formula (4) are alkylene groups having 1 to 5 carbon atoms. It is. If the alkylene group has more than 5 carbon atoms, the curing rate of the episulfide compound tends to be slow.

  R1 and R2 in the above formula (1), R51 and R52 in the above formula (2), R7 in the above formula (3), and R59 in the above formula (4) are each an alkylene having 1 to 3 carbon atoms. It is preferably a group, more preferably a methylene group. The alkylene group may be an alkylene group having a straight chain structure or an alkylene group having a branched structure.

  The said curable compound may contain the epoxy compound represented by following formula (11) or (12). The curable compound preferably contains an episulfide compound represented by the above formula (1) or (2) and an epoxy compound represented by the following formula (11) or (12).

  In said formula (11), R11 and R12 represent a C1-C5 alkylene group, respectively, 2-4 groups among four groups of R13, R14, R15, and R16 represent hydrogen, R13 , R14, R15 and R16, which are not hydrogen, represent a group represented by the following formula (13).

  All four groups of R13, R14, R15 and R16 in the above formula (11) may be hydrogen. One or two of the four groups of R13, R14, R15 and R16 is a group represented by the following formula (13), and among the four groups of R13, R14, R15 and R16 The group that is not a group represented by the following formula (13) may be hydrogen.

  In the above formula (12), R61 and R62 each represent an alkylene group having 1 to 5 carbon atoms, and 4 to 6 groups out of 6 groups of R63, R64, R65, R66, R67 and R68 are hydrogen. The group which is not hydrogen among R63, R64, R65, R66, R67 and R68 represents a group represented by the following formula (14).

  All of the six groups of R63, R64, R65, R66, R67 and R68 in the above formula (12) may be hydrogen. One or two of the six groups R63, R64, R65, R66, R67 and R68 are groups represented by the following formula (14), and R63, R64, R65, R66, R67 and R68. Of these six groups, a group that is not a group represented by the following formula (14) may be hydrogen.

  In said formula (13), R17 represents a C1-C5 alkylene group.

  In said formula (14), R69 represents a C1-C5 alkylene group.

  R11 and R12 in the formula (11), R61 and R62 in the formula (12), R17 in the formula (13), and R69 in the formula (14) are alkylene groups having 1 to 5 carbon atoms. It is. When the number of carbon atoms of the alkylene group exceeds 5, the curing rate of the compound represented by the formula (11) or (12) tends to be slow.

  R11 and R12 in the above formula (11), R61 and R62 in the above formula (12), R17 in the above formula (13), and R69 in the above formula (14) are each an alkylene having 1 to 3 carbon atoms. It is preferably a group, more preferably a methylene group. The alkylene group may be an alkylene group having a straight chain structure or an alkylene group having a branched structure.

  A mixture of an episulfide compound having a structure represented by the above formula (1) or (2) and an epoxy compound represented by the above formula (11) or (12) (hereinafter sometimes abbreviated as “mixture A”) The manufacturing method is not particularly limited. Examples of the production method include a production method in which an epoxy compound represented by the above formula (11) or (12) is prepared and a part of the epoxy group of the epoxy compound is converted into a thiirane group.

  In the method for producing the mixture A, the epoxy compound represented by the above formula (11) or (12) or a solution containing the epoxy compound was continuously or intermittently added to the first solution containing thiocyanate. Thereafter, a method of further adding the second solution containing thiocyanate continuously or intermittently is preferable. By this method, some epoxy groups of the epoxy compound can be converted into thiirane groups. As a result, the mixture A can be obtained.

  The curable compound is a monomer of an epoxy compound having a structure represented by the following formula (21), a multimer in which at least two epoxy compounds are bonded, or a mixture of the monomer and the multimer. May be included.

  In said formula (21), R1 represents a C1-C5 alkylene group, R2 represents a C1-C5 alkylene group, R3 is a hydrogen atom, a C1-C5 alkyl group, or following formula ( 22), R4 represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a structure represented by the following formula (23).

  In said formula (22), R5 represents a C1-C5 alkylene group.

  In said formula (23), R6 represents a C1-C5 alkylene group.

  The epoxy compound having the structure represented by the above formula (21) has an unsaturated double bond and at least two epoxy groups. By using an epoxy compound having a structure represented by the above formula (21), the anisotropic conductive material can be rapidly cured at a low temperature.

  The curable compound includes a monomer having a structure represented by the following formula (31), a multimer in which at least two of the compounds are bonded, or a mixture of the monomer and the multimer. You may go out.

  In the above formula (31), R1 represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a structure represented by the following formula (32), R2 represents an alkylene group having 1 to 5 carbon atoms, and R3 represents carbon. X 1 represents an oxygen atom or a sulfur atom, and X 2 represents an oxygen atom or a sulfur atom.

  In said formula (32), R4 represents a C1-C5 alkylene group, X3 represents an oxygen atom or a sulfur atom.

  The epoxy compound corresponding to the compound having the structure represented by the above formula (31) can be synthesized, for example, as follows.

  A raw material compound, a fluorene compound having a hydroxyl group, epichlorohydrin, sodium hydroxide, and methanol are mixed, cooled, and reacted. Thereafter, an aqueous sodium hydroxide solution is dropped. After dripping, it is further reacted to obtain a reaction solution. Next, water and toluene are added to the reaction solution, and the toluene layer is taken out. The toluene layer is washed with water and then dried to remove water and the solvent. In this way, an epoxy compound corresponding to the compound having the structure represented by the formula (31) can be easily obtained. In addition, the fluorene compound which has a hydroxyl group which is a raw material compound is marketed, for example from JFE Chemical Company etc., for example.

  Further, the thiirane group-containing compound corresponding to the compound having the structure represented by the above formula (31) has the epoxy group of the epoxy compound corresponding to the compound having the structure represented by the above formula (31) as a thiirane group. It can be synthesized by conversion. For example, after adding an epoxy compound that is a raw material compound or a solution containing the epoxy compound to a solution containing thiocyanate, an epoxy group is easily converted into a thiirane group by further adding a solution containing thiocyanate. it can.

  The said curable compound may contain the epoxy compound which has a heterocyclic ring containing a nitrogen atom. The epoxy compound having a heterocyclic ring containing a nitrogen atom is preferably an epoxy compound represented by the following formula (41) or an epoxy compound represented by the following formula (42). By using such a curable compound, the curing rate of the anisotropic conductive material can be further increased, and the heat resistance of the cured product of the anisotropic conductive material can be further enhanced.

  In said formula (41), R1-R3 represents a C1-C5 alkylene group, respectively, Z represents an epoxy group or a hydroxymethyl group. R21 to R23 may be the same or different.

  In the above formula (42), R1 to R3 each represent an alkylene group having 1 to 5 carbon atoms, p, q and r each represents an integer of 1 to 5, and R4 to R6 each represent an alkylene having 1 to 5 carbon atoms. Represents a group. R1 to R3 may be the same or different. p, q and r may be the same or different. R4-6 may be the same or different.

  The epoxy compound having a heterocyclic ring containing a nitrogen atom is preferably triglycidyl isocyanurate or trishydroxyethyl isocyanurate triglycidyl ether. By using these curable compounds, the curing rate of the anisotropic conductive material can be further increased.

  The curable compound preferably includes an epoxy compound having an aromatic ring. By using an epoxy compound having an aromatic ring, the curing rate of the anisotropic conductive material can be further increased and the anisotropic conductive material can be easily applied. From the viewpoint of further improving the applicability of the anisotropic conductive material, the aromatic ring is preferably a benzene ring, a naphthalene ring or an anthracene ring. Examples of the epoxy compound having an aromatic ring include resorcinol diglycidyl ether or 1,6-naphthalenediglycidyl ether. Of these, resorcinol diglycidyl ether is particularly preferable. By using resorcinol diglycidyl ether, the curing rate of the anisotropic conductive material can be increased and the anisotropic conductive material can be easily applied.

[Photocurable compound]
The curable compound according to the present invention may contain a photocurable compound so as to be cured by light irradiation. The curable compound can be semi-cured by light irradiation, and the fluidity of the curable compound can be reduced.

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

  Examples of the (meth) acrylic resin include an ester compound obtained by reacting (meth) acrylic acid and a compound having a hydroxyl group, and an epoxy (meth) acrylate obtained by reacting (meth) acrylic acid and an epoxy compound. Urethane (meth) acrylate obtained by reacting a (meth) acrylic acid derivative having a hydroxyl group with isocyanate is preferably used.

[Light and thermosetting compounds]
In the case where the curable compound includes, for example, a thermosetting compound and a photocurable compound, from the viewpoint of easily controlling the curing of the anisotropic conductive material or further improving the conduction reliability of the connection structure. The curable compound is a light and thermosetting compound having at least one group selected from an epoxy group and a thiirane group and a (meth) acryloyl group (hereinafter also referred to as a partially (meth) acrylated epoxy resin). It is preferable to contain. The (meth) acrylate means acrylate or methacrylate.

  The partially (meth) acrylated epoxy resin can be obtained, for example, by reacting an epoxy resin and (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 groups are converted to (meth) acryloyl groups (conversion rate) and partially (meth) acrylated. More preferably, 50% of the epoxy groups are converted to (meth) acryloyl groups. The (meth) acryloyl represents acryloyl or methacryloyl.

  From the viewpoint of increasing the curability of the anisotropic conductive material, the preferable lower limit of the content of the partially (meth) acrylated epoxy resin is 0.1% by weight and the more preferable lower limit is 0 in 100% by weight of the curable compound. 0.5 wt%, the preferred upper limit is 2 wt%, and the more preferred upper limit is 1.5 wt%.

  Examples of the epoxy (meth) acrylate 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. .

  When a photocurable compound other than the above-described curable compound is included, the photocurable compound may be a crosslinkable compound or a non-crosslinkable compound.

  Specific examples of the crosslinkable compound include 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, (poly ) Ethylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, pentaerythritol di (meth) acrylate, glycerol methacrylate acrylate, pentaerythritol tri (meth) acrylate, tri Examples include methylolpropane trimethacrylate, allyl (meth) acrylate, vinyl (meth) acrylate, divinylbenzene, polyester (meth) acrylate, and urethane (meth) acrylate.

  Specific examples of the non-crosslinkable compound include ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) ) Acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, nonyl (meth) acrylate, decyl Examples include (meth) acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate, tridecyl (meth) acrylate, and tetradecyl (meth) acrylate.

(Thermosetting agent)
A conventionally well-known thermosetting agent can be used for the said thermosetting agent, and it is not specifically limited. 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.

  The imidazole curing agent is not particularly limited, and 2-methylimidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2, 4-Diamino-6- [2'-methylimidazolyl- (1 ')]-ethyl-s-triazine and 2,4-diamino-6- [2'-methylimidazolyl- (1')]-ethyl-s- Examples include triazine isocyanuric acid adducts.

  The polythiol curing agent is not particularly limited, and examples include trimethylolpropane tris-3-mercaptopropionate, pentaerythritol tetrakis-3-mercaptopropionate, and dipentaerythritol hexa-3-mercaptopropionate. .

  The amine curing agent is not particularly limited, and hexamethylene diamine, octamethylene diamine, decamethylene diamine, 3,9-bis (3-aminopropyl) -2,4,8,10-tetraspiro [5.5]. Examples include undecane, bis (4-aminocyclohexyl) methane, metaphenylenediamine, and diaminodiphenylsulfone.

  The content of the thermosetting agent is not particularly limited. When the thermosetting agent is contained, the preferable lower limit of the content of the thermosetting agent is 5 parts by weight, the more preferable lower limit is 10 parts by weight, and the preferable upper limit is 100 parts by weight of the curable compound. 30 parts by weight, and a more preferable upper limit is 20 parts by weight. If content of the said thermosetting agent satisfy | fills the said preferable minimum and upper limit, an anisotropic conductive material can fully be thermosetted.

(Photocuring initiator)
A conventionally well-known photocuring initiator can be used for the said photocuring initiator, and it is not specifically limited. 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. When the photocuring initiator is contained, the preferable lower limit of the content of the photocuring initiator is 0.1 parts by weight and the more preferable lower limit is 0.2 with respect to 100 parts by weight of the curable compound. Part by weight, the preferred upper limit is 2 parts by weight, and the more preferred upper limit is 1 part by weight. If content of the said photocuring initiator satisfy | fills the said preferable minimum and upper limit, an anisotropic conductive material can be photocured moderately. For example, the anisotropic conductive material can be prevented from flowing by irradiating the anisotropic conductive material with light to form a B-stage.

(Conductive particles)
As the conductive particles contained in the inner layer 2, for example, conventionally known conductive particles capable of electrically connecting the electrodes are used. The conductive particles are preferably particles having a conductive layer on the outer surface. The conductive particles may have insulating particles attached to the surface of the conductive layer, or the surface of the conductive layer may be covered with an insulating layer. In this case, the insulating particles or the insulating layer is removed by pressurization when the electrodes are connected.

  Examples of the conductive particles include organic particles, inorganic particles, organic-inorganic hybrid particles, or conductive particles whose surfaces are covered with a conductive layer, and metal particles that are substantially composed of only metal. Is mentioned. The conductive layer is not particularly limited. Examples of the conductive layer include a gold layer, a silver layer, a copper layer, a nickel layer, a palladium layer, or a conductive layer containing tin.

  In 100% by weight of the inner layer 2, the content of the conductive particles is preferably in the range of 1 to 15% by weight. A more preferable lower limit of the content of the conductive particles is 5% by weight, and a more preferable upper limit is 10% by weight. When the content of the conductive particles is within the above range, the conductive particles can be easily arranged between the upper and lower electrodes to be connected. 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 prevented.

(Other ingredients)
The anisotropic conductive material may contain a solvent. By using the solvent, the viscosity of the inner layer 2 and the outer layer 3 can be easily adjusted. Furthermore, for example, when the curable compound is solid, the dispersibility of the curable compound can be increased by adding a solvent to the solid curable compound and dissolving it. Examples of the solvent include ethyl acetate, methyl cellosolve, toluene, acetone, methyl ethyl ketone, cyclohexane, n-hexane, tetrahydrofuran, and diethyl ether.

  Since the adhesive force of the cured product of the anisotropic conductive material can be increased, the anisotropic conductive material preferably contains an adhesive strength adjusting agent. From the viewpoint of further increasing the adhesive strength, the adhesive strength modifier is preferably a silane coupling agent.

  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. The filler is not particularly limited. Examples of the filler include silica, aluminum nitride, and alumina. As for the said filler, only 1 type may be used and 2 or more types may be used together.

  The content of the filler is not particularly limited. The preferable lower limit of the filler content is 70 parts by weight, the more preferable lower limit is 80 parts by weight, the preferable upper limit is 100 parts by weight, and the more preferable upper limit is 90 parts by weight with respect to the total of 100 parts by weight of the curable compound. . When content of the said filler satisfy | fills the said preferable minimum and upper limit, the latent thermal expansion of the cured | curing material of an anisotropic conductive material can fully be suppressed, and also a filler can fully be disperse | distributed in an anisotropic conductive material.

  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 composition for forming inner layer Preparation of episulfide compound-containing mixture:
In a 2 L container equipped with a stirrer, a cooler, and a thermometer, 250 mL of ethanol, 250 mL of pure water, and 20 g of potassium thiocyanate were added to dissolve potassium thiocyanate, thereby preparing a first solution. Thereafter, the temperature in the container was kept in the range of 20 to 25 ° C. Next, 160 g of resorcinol diglycidyl ether was dropped into the first solution at a rate of 5 mL / min while stirring the first solution in the container maintained at 20 to 25 ° C. After dropping, 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, a second solution in which 20 g of potassium thiocyanate is dissolved in a solution containing 100 mL of pure water 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. And stirred for 30 minutes. 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.

¹ H-NMR measurement of the obtained episulfide compound-containing mixture was performed using chloroform as a solvent. 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 ¹ H-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.

Preparation of the composition for forming the inner layer:
30 parts by weight of the resulting episulfide compound-containing mixture, 5 parts by weight of an amine adduct (“PN-23J” manufactured by Ajinomoto Fine Techno Co.) as a thermosetting agent, and an epoxy acrylate (manufactured by Daicel Cytec Co., Ltd.) as a photocurable compound “EBECRYL 3702”) 5 parts by weight, 0.1 part by weight of an acylphosphine oxide compound (“DAROCUR TPO” manufactured by Ciba Japan) as a photopolymerization initiator, and 2-ethyl-4-methyl as a curing accelerator 1 part by weight of imidazole, 20 parts by weight of silica having an average particle diameter of 0.25 μm as filler and 20 parts by weight of alumina having an average particle diameter of 0.5 μm are blended, and further conductive particles having an average particle diameter of 3 μm are blended 100 After adding so that the content in 10% by weight is 10% by weight, it is 2000 using a planetary stirrer. The formulation was obtained by stirring for 5 minutes at 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 composition for forming the inner layer whose content of electroconductive particle is 10 weight% was obtained by filtering the obtained compound using nylon filter paper (pore diameter 10 micrometers).

(2) Preparation of composition for forming outer layer An amine adduct (Ajinomoto Fine Techno Co., Ltd.) as a thermosetting agent was added to 30 parts by weight of the episulfide compound-containing mixture obtained in the preparation of the composition for forming the inner layer. “PN-23J”) 5 parts by weight, 1 part by weight of 2-ethyl-4-methylimidazole as a curing accelerator, 10 parts by weight of silica having an average particle diameter of 0.25 μm and an average particle diameter of 0. A composition for forming an outer layer was obtained by blending 10 parts by weight of 5 μm alumina.

(3) Production of Connection Structure A transparent glass substrate having an ITO electrode pattern with an L / S of 30 μm / 30 μm formed on the upper surface was prepared. Further, a semiconductor chip was prepared in which a copper electrode pattern having L / S of 30 μm / 30 μm was formed on the lower surface.

As shown in FIGS. 1A to 1C, by discharging the composition for forming the inner layer and the composition for forming the outer layer from the tip 31a of the dispenser 31 shown in FIG. An anisotropic conductive material was disposed on the upper surface of the transparent glass substrate to form an anisotropic conductive material layer. The thickness of the inner layer of the disposed anisotropic conductive material layer is 15 μm, the thickness of each outer layer laminated on one side and the other side of the inner layer is 7.5 μm (total thickness of both sides 15 μm), anisotropic conductive material The layer thickness was 30 μm. While the anisotropic conductive material is arranged, the anisotropic conductive material layer is irradiated with ultraviolet light of 420 nm so that the light irradiation intensity is 50 mW / cm ² using an ultraviolet irradiation lamp, and the inner layer is formed into a B stage by photopolymerization. Turned into. The time T from when the anisotropic conductive material layer was in contact with the transparent glass substrate to when the anisotropic conductive material layer was irradiated with light was 0.5 seconds.

  After irradiation with light, it was left for 60 seconds. Immediately after the light irradiation, the B-stage inner layer gradually descended. By allowing the time to stand, the B-staged inner layer dropped and contacted the upper surface of the transparent glass substrate.

Next, the semiconductor chip was laminated on the upper surface of the anisotropic conductive material layer including the inner layer and the outer layer which were B-staged so that the electrodes face each other. Then, while adjusting the temperature of the head so that the temperature of the anisotropic conductive paste layer becomes 185 ° C., a pressure heating head is placed on the upper surface of the semiconductor chip and a pressure of 10 kg / cm ² is applied to form a B stage. The inner and outer layers thus obtained were completely cured at 185 ° C. to obtain a connection structure.

(Example 2)
The thickness of the inner layer of the disposed anisotropic conductive material layer is 20 μm, the thickness of each outer layer laminated on one side and the other side of the inner layer is 5 μm (total thickness of both sides is 10 μm), A connection structure was obtained in the same manner as in Example 1 except that the thickness was changed to 30 μm.

(Example 3)
Except that the time T from when the anisotropic conductive material layer was in contact with the transparent glass substrate to when the anisotropic conductive material layer was irradiated with light was changed to 3 seconds, the same as in Example 1, A connection structure was obtained.

Example 4
A connection structure was obtained in the same manner as in Example 1 except that the standing time after irradiation with light was changed to 120 seconds.

(Example 5)
Composition for forming the inner layer in the same manner as in Example 1 except that the content of the conductive particles was changed from 10% by weight to 1% by weight when preparing the composition for forming the inner layer. Got. A connection structure was obtained in the same manner as in Example 1 except that the composition for forming the obtained inner layer was used.

(Example 6)
Composition for forming the inner layer in the same manner as in Example 1 except that the content of the conductive particles was changed from 10% by weight to 15% by weight when preparing the composition for forming the inner layer. Got. A connection structure was obtained in the same manner as in Example 1 except that the composition for forming the obtained inner layer was used.

(Example 7)
In preparing the composition for forming the inner layer, the inner layer was changed in the same manner as in Example 1 except that the epoxy acrylate as the photocurable compound was changed to urethane acrylate ("EBECRYL8804" manufactured by Daicel-Cytec). A composition for forming was obtained. A connection structure was obtained in the same manner as in Example 1 except that the composition for forming the obtained inner layer was used.

(Example 8)
When preparing a composition for forming an inner layer, an episulfide compound-containing mixture as a thermosetting compound was subjected to a bisphenol A-type episulfide compound-containing mixture (bisphenol A-type epoxy resin (“jER1001” manufactured by Japan Epoxy Resin)) A composition for forming an inner layer was obtained in the same manner as in Example 1 except that the production was performed in the same manner as in the preparation of the episulfide compound-containing mixture described in Example 1. A connection structure was obtained in the same manner as in Example 1 except that the composition for forming the obtained inner layer was used.

Example 9
When preparing the composition for forming the outer layer, the episulfide compound-containing mixture as a thermosetting compound was subjected to a bisphenol A-type episulfide compound-containing mixture (bisphenol A-type epoxy resin (“jER1001” manufactured by Japan Epoxy Resin Co., Ltd.)). A composition for forming an outer layer was obtained in the same manner as in Example 1 except that the composition was changed to the preparation of episulfide compound-containing mixture described in Example 1). A connection structure was obtained in the same manner as in Example 1 except that the composition for forming the obtained outer layer was used.

(Reference Example 1)
The composition for forming the inner layer obtained in Example 1 was used alone as an anisotropic conductive material.

  The obtained anisotropic conductive material was applied to the upper surface of the transparent glass substrate prepared in Example 1 from a dispenser nozzle so as to have a thickness of 30 μm to form an anisotropic conductive material layer. No light was irradiated during and after application of the anisotropic conductive material.

Next, the semiconductor chip was laminated on the upper surface of the anisotropic conductive paste layer so that the electrodes face each other. After that, while adjusting the head temperature so that the temperature of the anisotropic conductive paste layer becomes 185 ° C., a pressure heating head is placed on the upper surface of the semiconductor chip, and a pressure of 10 kg / cm ² is applied to apply the anisotropic conductive paste. The paste layer was completely cured at 185 ° C. to obtain a connection structure.

(Evaluation)
(1) The viscosity η1 of the inner layer before curing and the viscosity η2 of the outer layer before curing
The viscosity η1 of the inner layer before curing and the viscosity η2 of the outer layer before curing were measured using an E-type viscometer (manufactured by Toki Sangyo Co., Ltd.) at 25 ° C. and 2.5 rpm.

(2) Viscosity of B-staged anisotropic conductive paste layer In Examples and Comparative Examples, after the inner layer was B-staged by photopolymerization, a semiconductor chip was placed on the upper surface of the B-staged inner layer. The viscosity of the B-staged inner layer immediately before lamination was measured using an E-type viscometer (manufactured by Toki Sangyo Co., Ltd.) at 25 ° C. and 2.5 rpm.

(3) Leak Evaluation Using the obtained connection structure, it was measured with a tester whether or not a leak occurred in 20 adjacent electrodes.

(4) Presence / absence of voids In the obtained connection structure, whether or not voids were generated in the cured product layer formed of the anisotropic conductive paste layer was visually observed from the lower surface side of the transparent glass substrate.

  The results are shown in Table 1 below.

DESCRIPTION OF SYMBOLS 1 ... Anisotropic conductive material 1A ... Anisotropic conductive material layer 1a ... Upper surface 2 ... Inner layer 2a ... One 2b ... The other 2A ... Inner layer B-stage 3 ... Outer layer 4 ... Conductive particle 21 ... Connection structure 22 ... 1st connection object member 22a ... Upper surface 22b ... Electrode 23 ... 2nd connection object member 23a ... Upper surface 23b ... Electrode 24 ... Cured material layer 31 ... Dispenser 31a ... Tip 32 ... Outer wall 33 ... Partition wall

Claims (8)

An inner layer and an outer layer covering the inner layer so as to surround the outer peripheral surface of the inner layer;
By covering the inner layer so as to surround the outer peripheral surface of the inner layer, the outer layer is laminated on one side of the inner layer and the other side opposite to the one side ,
The inner layer includes a curable compound, at least one of a thermosetting agent and a photocuring initiator, and conductive particles; and
An anisotropic conductive material, wherein the outer layer includes a curable compound and at least one of a thermosetting agent and a photocuring initiator. The inner layer includes a mixture of a thermosetting compound and a photocurable compound, a thermosetting agent, a photocuring initiator, and conductive particles, or a photocurable compound, a photocuring initiator, and a conductive material. Sex particles, and
The anisotropic conductive material according to claim 1, wherein the outer layer includes a thermosetting compound and a thermosetting agent.   The anisotropic conductive material according to claim 2, wherein the inner layer includes a mixture of a thermosetting compound and a photocurable compound, a thermosetting agent, a photocuring initiator, and conductive particles. The curable compound contained in the inner layer contains a curable compound having a (meth) acryloyl group, and
The anisotropic conductive material of any one of Claims 1-3 in which the curable compound contained in the said outer layer contains the curable compound which has at least 1 type of an epoxy group and an episulfide group.   The anisotropic conductive material of any one of Claims 1-4 whose viscosity of the said inner layer is higher than the viscosity of the said outer layer. The anisotropic conductive material according to any one of claims 1 to 5 is disposed on an upper surface of a first connection target member, and the outer layer is positioned between the first connection target member and the inner layer. A step of forming an anisotropic conductive material layer,
By irradiating light or applying heat to the anisotropic conductive material layer and proceeding curing of the inner layer, the inner layer is made into a B-stage, and the B-staged inner layer is the first connection target member. Moving the B-stage inner layer so as to approach the upper surface;
After the B-staged inner layer moves, a second connection target member is further laminated on the upper surface of the anisotropic conductive material layer, and the B-staged inner layer and the outer layer are cured, thereby connecting structure The manufacturing method of a connection structure provided with the process of obtaining a body. The connection structure according to claim 6 , wherein in the step of moving the inner layer, the B-staged inner layer is moved so that the B-staged inner layer is in contact with an upper surface of the first connection target member. Manufacturing method. A first connection target member, a second connection target member, and a cured product layer connecting the first and second connection target members,
The connection structure body in which the said hardened | cured material layer is formed by hardening the anisotropic electrically-conductive material of any one of Claims 1-5 .

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