JP5883679B2 - Method for manufacturing connection structure, anisotropic conductive material, and connection structure - Google Patents

Description

  The present invention relates to a method for manufacturing a connection structure using an anisotropic conductive material including a plurality of conductive particles, a method for manufacturing a connection structure for electrically connecting electrodes of a semiconductor chip and a glass substrate, and The present invention relates to the anisotropic conductive material and the connection structure.

  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.

  In order to obtain various connection structures, the anisotropic conductive material is, for example, a connection between a flexible printed circuit board and a glass substrate (FOG (Film on Glass)) or a connection between a semiconductor chip and a flexible printed circuit board (COF ( Chip on Film)), connection between a semiconductor chip and a glass substrate (COG (Chip on Glass)), connection between a flexible printed circuit board and a glass epoxy substrate (FOB (Film on Board)), and the like.

  As an example of the manufacturing method of the connection structure, in Patent Document 1, a semiconductor chip and a glass are formed using an anisotropic conductive material including an adhesive component containing a thermosetting resin and elastomer fine particles and conductive particles. A method for manufacturing a connection structure for connecting a substrate is disclosed.

  Further, in Patent Document 2 below, a first circuit member having a first circuit electrode and a second circuit member having a second circuit electrode and constituting a tape carrier package or a flexible printed circuit board, A method for manufacturing a connection structure is disclosed in which the first circuit electrode and the second circuit electrode are arranged to face each other and are connected by an anisotropic conductive material. Further, in Patent Document 2, a film-like circuit connecting material is used as an anisotropic conductive material containing a thermosetting composition and a photocurable composition, and the film-like circuit connecting material is irradiated with light. A method of curing the thermosetting resin composition by curing the photocurable resin composition, reducing the fluidity of the film-like circuit connecting material, and then heating the film-like circuit connecting material during the main connection. Have been described.

Japanese Patent No. 3365367 JP 2005-235530 A

  In the manufacturing method of the conventional connection structure as described in Patent Documents 1 and 2, components other than the conductive particles in the anisotropic conductive material may not be sufficiently excluded from between the conductive particles and the electrode. is there. That is, a component other than the conductive particles in the anisotropic conductive material may remain between the conductive particles and the electrode. Therefore, the indentation formed by the conductive particles being pushed into the surface of the electrode may not be sufficiently formed. For this reason, there exists a problem that the conduction | electrical_connection reliability of the connection structure obtained becomes low.

  Furthermore, in the conventional method for manufacturing a connection structure, the anisotropic conductive material disposed on the connection target member and the conductive particles contained in the anisotropic conductive material are not cured before or during the main curing. May flow excessively. For this reason, the hardened | cured material layer and electroconductive particle formed with the anisotropic electrically-conductive material may be unable to be arrange | positioned in a specific area | region. This may also reduce the conduction reliability of the resulting connection structure. Furthermore, voids may be generated in the cured product layer, and the conduction reliability of the resulting connection structure may be lowered. If there are voids in the cured product layer, not only the conduction reliability between the electrodes is lowered, but also the connection reliability between the connection target member and the cured product layer is lowered.

  The objective of this invention is providing the manufacturing method of the connection structure which can improve the conduction | electrical_connection reliability between electrodes, an anisotropic conductive material, and a connection structure.

  A limited object of the present invention is to provide a method for manufacturing a connection structure that can make it difficult to generate voids in a cured layer obtained by curing an anisotropic conductive material, and an anisotropic conductive material and a connection structure. Is to provide.

According to a wide aspect of the present invention, there is provided a manufacturing method of a connection structure for connecting a semiconductor chip and a glass substrate, wherein a thermosetting component and conductive particles are formed on a first connection target member having an electrode on an upper surface. A step of disposing an anisotropic conductive material layer using an anisotropic conductive material including: a step of laminating a second connection target member having an electrode on the bottom surface on the top surface of the anisotropic conductive material layer; A step of heating and curing the anisotropic conductive material layer to form a cured product layer, and determining the storage elastic modulus G ′ ₂₅ at 25 ° C. of the anisotropic conductive material layer before the main curing. The minimum loss elastic modulus G ″ _min is 5 × 10 ² when the anisotropic conductive material layer before main curing is heated from 25 ° C. to 250 ° C. at 1 × 10 ⁵ Pa or more and 1 × 10 ⁷ Pa or less. Pa or more, to less than 1 × ¹⁰ 5 Pa, the second connection object member and said first connection As elephant member, using a semiconductor chip and a glass substrate, a manufacturing method of the connecting structure is provided.

  In a specific aspect of the manufacturing method of the connection structure according to the present invention, before the main curing, the anisotropic conductive material layer is heated or irradiated with light so that the curing proceeds, and a B stage is formed. A step of forming the anisotropic conductive material layer is further provided, and the anisotropic conductive material layer before main curing is a B-staged anisotropic conductive material layer, and the anisotropic conductive material layer In the case of irradiating light, an anisotropic conductive material including a thermosetting component, a photocurable component, and conductive particles is used as the anisotropic conductive material.

  In another specific aspect of the method for manufacturing the connection structure according to the present invention, before the main curing, the anisotropic conductive material layer is irradiated with light so that the curing proceeds and the B-staged anisotropic is performed. A step of forming a conductive conductive material layer, wherein the anisotropic conductive material layer before main curing is a B-staged anisotropic conductive material layer, and the anisotropic conductive material is thermoset. An anisotropic conductive material containing an adhesive component, a photocurable component, and conductive particles is used.

  In the method for producing a connection structure according to the present invention, as the anisotropic conductive material, a compound having an epoxy group or a thiirane group, a compound having a (meth) acryloyl group, a thermosetting agent, and a photocuring initiator, It is preferable to use an anisotropic conductive material containing conductive particles. Further, as the anisotropic conductive material, an anisotropy comprising a compound having an epoxy group or thiirane group, a compound having a (meth) acryloyl group, a thermosetting agent, a photo radical initiator, and conductive particles. It is more preferable to use a conductive material. Furthermore, in the manufacturing method of the connection structure according to the present invention, it is preferable to use an anisotropic conductive paste as the anisotropic conductive material.

Moreover, according to the wide aspect of this invention, it is an anisotropic conductive material used in order to connect a semiconductor chip and a glass substrate, Comprising: A thermosetting component and electroconductive particle are included, and it stores at 25 degreeC. The elastic modulus G ′ ₂₅ is 1 × 10 ⁵ Pa or more and 1 × 10 ⁷ Pa or less, and the minimum loss elastic modulus G ″ _min when heated from 25 ° C. to 250 ° C. is 5 × 10 ² Pa or more, An anisotropic conductive material having 1 × 10 ⁵ Pa or less is provided.

In a specific aspect of the anisotropic conductive material according to the present invention, the B-stage is formed after forming the B-staged anisotropic conductive material by curing by applying heat or irradiating light. The storage elastic modulus G ′ ₂₅ at 25 ° C. is used for the purpose of heating the anisotropic conductive material for main curing, and the storage elastic modulus G ′ at 25 ° C. of the B-staged anisotropic conductive material is used. ₂₅ , and the minimum loss elastic modulus G ″ _min when heated from 25 ° C. to 250 ° C. is the minimum loss elastic modulus when the B-staged anisotropic conductive material is heated from 25 ° C. to 250 ° C. In the case of an anisotropic conductive material that is G ″ _min and advances curing by light irradiation, the anisotropic conductive material includes a thermosetting component, a photocurable component, and conductive particles.

In another specific aspect of the anisotropic conductive material according to the present invention, the curing proceeds by light irradiation to form a B-staged anisotropic conductive material, and then the B-staged anisotropy. The storage elastic modulus G ′ ₂₅ at 25 ° C. is the storage elastic modulus G ′ ₂₅ at 25 ° C. of the B-staged anisotropic conductive material. The minimum loss elastic modulus G ″ _min when heated from 25 ° C. to 250 ° C. is the minimum loss elastic modulus G ″ when the B-staged anisotropic conductive material is heated from 25 ° C. to 250 ° C. _min and the anisotropic conductive material includes a thermosetting component, a photocurable component, and conductive particles.

  The anisotropic conductive material according to the present invention may include a compound having an epoxy group or a thiirane group, a compound having a (meth) acryloyl group, a thermosetting agent, a photocuring initiator, and conductive particles. preferable. Furthermore, the anisotropic conductive material according to the present invention includes a compound having an epoxy group or a thiirane group, a compound having a (meth) acryloyl group, a thermosetting agent, a photo radical initiator, and conductive particles. It is more preferable. Furthermore, the anisotropic conductive material according to the present invention is preferably an anisotropic conductive paste.

  The connection structure according to the present invention includes a first connection target member having an electrode on an upper surface, a second connection target member having an electrode on a lower surface, the first connection target member, and the second connection target member. And the cured product layer is formed by heating and anisotropically curing the anisotropic conductive material configured according to the present invention, and the second connection object. The member and the first connection target member are a semiconductor chip and a glass substrate.

In the method for manufacturing a connection structure according to the present invention, an anisotropic conductive material layer using an anisotropic conductive material containing a thermosetting component and conductive particles is heated to be fully cured. The storage elastic modulus G ′ ₂₅ at 25 ° C. of the anisotropic conductive material layer is set to 1 × 10 ⁵ Pa or more and 1 × 10 ⁷ Pa or less, and the anisotropic conductive material layer before main curing is started from 25 ° C. Since the minimum loss elastic modulus G ″ _min when heated to 250 ° C. is set to 5 × 10 ² Pa or more and 1 × 10 ⁵ Pa or less, it is between the electrodes in the connection structure in which the semiconductor chip and the glass substrate are connected. The conduction reliability can be increased.

The anisotropic conductive material according to the present invention includes a thermosetting component and conductive particles, and a storage elastic modulus G ′ ₂₅ at 25 ° C. is 1 × 10 ⁵ Pa or more and 1 × 10 ⁷ Pa or less. Since the minimum loss elastic modulus G ″ _min when heated from 25 ° C. to 250 ° C. is 5 × 10 ² Pa or more and 1 × 10 ⁵ Pa or less, the anisotropic conductive material according to the present invention is used. When the semiconductor chip and the glass substrate are connected, the conduction reliability between the electrodes in the obtained connection structure can be improved.

FIG. 1 is a partially cutaway 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. 2 (a) to 2 (c) are partially cutaway front cross-sectional views for explaining each step of the method for manufacturing a connection structure according to one embodiment of the present invention. FIG. 3 is a schematic diagram for explaining a recess formed in the electrode.

  Hereinafter, the present invention will be described in detail.

  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.

  The connection structure 1 shown in FIG. 1 includes a first connection target member 2, a second connection target member 4, and a cured product layer 3 connecting the first and second connection target members 2 and 4. Is provided. The cured product layer 3 is a connection part that connects the first and second connection target members 2 and 4. The cured product layer 3 is formed by heating and main-curing an anisotropic conductive material (anisotropic conductive material layer) containing a thermosetting component and conductive particles 5. The anisotropic conductive material includes a plurality of conductive particles 5.

  The first connection target member 2 has a plurality of electrodes 2b on the upper surface 2a. The second connection target member 4 has a plurality of electrodes 4b on the lower surface 4a. 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. In the manufacturing method of the connection structure according to the present invention and the anisotropic conductive material according to the present invention, a semiconductor chip and a glass substrate are used as the second connection target member and the first connection target member.

The cured product layer is formed by heating and curing the anisotropic conductive material. The storage elastic modulus G ′ ₂₅ at 25 ° C. of the anisotropic conductive material (anisotropic conductive material layer) before main curing is 1 × 10 ⁵ Pa or more and 1 × 10 ⁷ Pa or less. The minimum loss elastic modulus G ″ _min when the anisotropic conductive material (anisotropic conductive material layer) before main curing is heated from 25 ° C. to 250 ° C. is 5 × 10 ² Pa or more, 1 × 10 ^5. Pa or less.

When the storage elastic modulus G ′ ₂₅ and the minimum loss elastic modulus G ″ _min are equal to or higher than the lower limit and equal to or lower than the upper limit, the conduction reliability between the electrodes in the connection structure in which the semiconductor chip and the glass substrate are connected is obtained. Can be increased. Furthermore, when the connection structure is produced, the components excluding the conductive particles in the anisotropic conductive material layer are excluded from between the electrode and the conductive particles, and the electrode and the conductive particles are effectively brought into contact with each other. Can do. Furthermore, a recess in which conductive particles are pushed into the electrode can be formed. As shown in FIG. 3, it is also possible to form the recessed part 2c in the electrode 2b by pushing in the conductive particles 5. The recess is also called an indentation. A recess may be formed in the electrode 4b. Further, when the storage elastic modulus G ′ ₂₅ and the minimum loss elastic modulus G ″ _min are not less than the lower limit and not more than the upper limit, voids are generated in the cured product layer in which the anisotropic conductive material is cured. It becomes difficult. For this reason, the connection reliability between the semiconductor chip and the glass substrate is increased, and the conduction reliability between the electrodes is further increased.

When a connection structure is produced using an anisotropic conductive material containing a thermosetting component and conductive particles, the first and second connection target members in the connection structure are further composed of a semiconductor chip and a glass substrate. In some cases, the storage elastic modulus G ′ ₂₅ and the minimum loss elastic modulus G ″ _min are not less than the above lower limit and not more than the above upper limit. It plays a big role in making it difficult for voids to form.

The storage elastic modulus G ′ ₂₅ at 25 ° C. of the anisotropic conductive material before main curing is preferably 5 × 10 ⁵ Pa or more, preferably 5 × 10 ⁶ Pa or less, more preferably 1 × 10 ⁶ Pa or less. It is. When the storage elastic modulus G ′ ₂₅ is not less than the above lower limit and not more than the above upper limit, the conduction reliability between the electrodes is further increased, and voids (voids) are more unlikely to be generated in the cured product layer.

The minimum loss elastic modulus G ″ _min when the anisotropic conductive material before main curing is heated from 25 ° C. to 250 ° C. is preferably 1 × 10 ³ Pa or more, more preferably 5 × 10 ³ Pa or more, Preferably, it is 5 × 10 ⁴ Pa or less. When the minimum loss elastic modulus G ″ _min is not less than the above lower limit and not more than the above upper limit, the conduction reliability between the electrodes is further increased, and voids (voids) are more unlikely to be generated in the cured product layer.

  In addition, the said hardened | cured material layer may be formed by heating and carrying out the main hardening, without making the said anisotropic conductive material B-stage. The anisotropic conductive material may be used for applications in which the anisotropic conductive material is heated to be fully cured.

The cured product layer is cured by applying heat or irradiating light to form a B-staged anisotropic conductive material, and then heating the B-staged anisotropic conductive material. It may be formed by main curing. The anisotropic conductive material is cured by applying heat or irradiating light to form a B-staged anisotropic conductive material, and then heating the B-staged anisotropic conductive material. And may be used for the purpose of main curing. In this case, the storage modulus G at the 25 ° C. _'25 are the storage modulus G at 25 ° C. of B-staged anisotropic conducting material' is _25, heated to 250 ° C. from the 25 ° C. minimum loss modulus G 'when the' _min is minimum loss modulus G upon heating the B-staged anisotropic conductive material to 250 ° C. from 25 ° C. 'a' _min. When the anisotropic conductive material layer is irradiated with light, an anisotropic conductive material including a thermosetting component, a photocurable component, and conductive particles is used as the anisotropic conductive material. That is, in the case of an anisotropic conductive material that progresses curing by light irradiation, the anisotropic conductive material includes a thermosetting component, a photocurable component, and conductive particles.

Further, the cured product layer is cured by light irradiation to form a B-staged anisotropic conductive material, and then the B-staged anisotropic conductive material is heated to be fully cured. It may be formed. The anisotropic conductive material is cured by light irradiation to form a B-staged anisotropic conductive material, and then the B-staged anisotropic conductive material is heated to be fully cured. It may be used for applications. In this case, the storage modulus G at the 25 ° C. _'25 are the storage modulus G at 25 ° C. of B-staged anisotropic conducting material' is _25, heated to 250 ° C. from the 25 ° C. minimum loss modulus G 'when the' _min is minimum loss modulus G upon heating the B-staged anisotropic conductive material to 250 ° C. from 25 ° C. 'a' _min.

The storage elastic modulus G ′ ₂₅ and the minimum loss elastic modulus G ″ _min are measured using a rotary dynamic viscoelastic device. As a rotary dynamic viscoelastic device for measuring the storage elastic modulus G ′ ₂₅ , “VAR-100” manufactured by Rheological Instruments Co., Ltd. is used. The storage elastic modulus G ′ ₂₅ is measured under the conditions of a frequency of 1 Hz, a strain of 1.0E-2, and a measurement temperature of 25 ° C. The minimum loss elastic modulus G ″ _min is measured under the conditions of a frequency of 1 Hz, a strain of 1.0E-2, and heating from 25 ° C. to 250 ° C.

The temperature range for heating the above-mentioned minimum loss elastic modulus G ″ _min is 25 ° C. to 250 ° C. The heating temperature when the anisotropic conductive material is heated to be fully cured is preferably 160 ° C. This is because the temperature is not lower than ° C., preferably not higher than 250 ° C.

  The connection structure 1 shown in FIG. 1 can be obtained as follows, for example. Here, the manufacturing method of the connection structure 1 when the anisotropic conductive material further containing a photocurable component in addition to the thermosetting component and the conductive particles 5 is used as the anisotropic conductive material. This will be specifically described.

  As shown to Fig.2 (a), the 1st connection object member 2 which has the electrode 2b on the upper surface 2a is prepared. Next, the upper surface of the first connection target member 2 is made of an anisotropic conductive material including a thermosetting component, a photocurable component, and conductive particles 5 on the upper surface 2a of the first connection target member 2. An anisotropic conductive material layer 3A is disposed on 2a. At this time, it is preferable that one or a plurality of conductive particles 5 be disposed on the electrode 2b. When an anisotropic conductive paste is used as the anisotropic conductive material, the anisotropic conductive paste is arranged by applying the anisotropic conductive paste. The anisotropic conductive material layer becomes an anisotropic conductive paste layer.

Next, the anisotropic conductive material layer 3A is cured by irradiating the anisotropic conductive material layer 3A with light. By curing the anisotropic conductive material layer 3A, the anisotropic conductive material layer 3A is B-staged. As shown in FIG. 2B, the anisotropic conductive material layer 3 </ b> B having the B stage is formed on the upper surface 2 a of the first connection target member 2 by forming the anisotropic conductive material layer 3 </ b> A into the B stage. . At this time, the storage elastic modulus G ′ ₂₅ at 25 ° C. of the B-staged anisotropic conductive material layer 3B to be finally cured, that is, the anisotropic conductive material layer 3B before the main cure is 1 × 10 ^5. Pa to 1 × 10 ⁷ Pa or less. Further, the B-staged anisotropic conductive material layer 3B to be finally cured, that is, the anisotropic conductive material layer 3B before the final curing is heated to a temperature of 25 ° C. to 250 ° C., and the lowest loss elastic modulus G ″. _Min is set to 5 × 10 ² Pa or more and 1 × 10 ⁵ Pa or less.

  It is preferable to irradiate the anisotropic conductive material layer 3 </ b> A with light while disposing the anisotropic conductive material on the upper surface 2 a of the first connection target member 2. Furthermore, it is also preferable to irradiate the anisotropic conductive material layer 3 </ b> A simultaneously with or immediately after the placement of the anisotropic conductive material on the upper surface 2 a of the first connection target member 2. When the arrangement and the light irradiation are performed as described above, the flow of the anisotropic conductive material layer can be further suppressed. For this reason, the conduction | electrical_connection reliability in the obtained connection structure 1 can be improved further. The time from the placement of the anisotropic conductive material on the upper surface 2a of the first connection target member 2 to the irradiation with light is 0 second or longer, preferably 3 seconds or shorter, more preferably 2 seconds or shorter.

  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, a light source having strong light emission at a specific wavelength of 420 nm or less, and the like. Specific examples of a light source having a sufficient light emission distribution at a wavelength of 420 nm or less 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 excited mercury lamp, a metal halide lamp, and the like. It is done. Moreover, an LED lamp etc. are mentioned as a specific example of the light source which has strong light emission in the specific wavelength of 420 nm or less. Among these, an LED lamp is preferable. The LED lamp generates very little heat of the irradiated object itself, and can prevent the anisotropic conductive material from being cured by the heat generation.

In order to make the anisotropic conductive material layer 3A into a B-stage by light irradiation, the light irradiation intensity for appropriately progressing the curing of the anisotropic conductive material layer 3A is, for example, an LED lamp having a peak at a wavelength of 365 nm When using a light source, it is preferably about 100 to 3000 mW / cm ² . Moreover, the light irradiation energy for advancing moderately curing the anisotropic conductive material layer 3A is preferably 500 mJ / cm ² or more, more preferably 2000 mJ / cm ² or more, preferably 100000mJ / cm ² or less, more Preferably it is 20000 mJ / cm < ² > or less.

Note that the anisotropic conductive material layer may be B-staged by applying heat, without making the anisotropic conductive material layer B-staged by light irradiation. When curing is carried out by applying heat to the anisotropic conductive material layer to make the anisotropic conductive material layer B-staged, heating to sufficiently make the anisotropic conductive material layer B-staged The temperature is preferably 80 ° C. or higher, preferably 130 ° C. or lower, more preferably 110 ° C. or lower. Even when the anisotropic conductive material layer is B-staged not by light irradiation but by application of heat, the storage elastic modulus G ′ ₂₅ and the minimum loss elastic modulus G ″ of the B-staged anisotropic conductive material layer are _{When min} is not less than the above lower limit and not more than the above upper limit, the conduction reliability between the electrodes becomes high, and voids are hardly generated in the cured product layer.

  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. In addition, after laminating | stacking the 2nd connection object member 4, in order to make 3 A of anisotropic conductive material layers into B stage, you may irradiate light and may provide heat | fever.

  Further, when the second connection target member 4 is laminated, the B-staged anisotropic conductive material layer 3 </ b> B is heated and fully cured to form the cured product layer 3. However, the anisotropic conductive material layer 3B may be heated before the second connection target member 4 is laminated. It is preferable that the anisotropic conductive material layer 3B is heated to be fully cured after the second connection target member 4 is stacked. At the same time as the second connection target member 4 is stacked, the anisotropic conductive material layer 3B is formed. It is more preferable to heat and perform the main curing.

  In order to cure the anisotropic conductive material layer 3B by applying heat, the heating temperature for sufficiently curing the anisotropic conductive material layer 3B is preferably 160 ° C or higher, preferably 250 ° C or lower, more preferably 200. It is below ℃.

  When the anisotropic conductive material layer 3A is not irradiated with light and the anisotropic conductive material layer 3A is not B-staged, the second connection target member is placed on the upper surface 3a of the anisotropic conductive material layer 3A. 4 is laminated and the anisotropic conductive material layer 3A is heated to be fully cured.

  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 cured product layer 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.

  Further, when the connection structure is manufactured, the anisotropic conductive paste is B-staged by applying heat or irradiating light, and then is cured to provide the anisotropy disposed on the first connection target member. The conductive particles contained in the paste layer are difficult to flow greatly in the curing stage. Accordingly, the conductive particles are easily arranged in a predetermined region. Specifically, conductive particles can be arranged between upper and lower electrodes to be connected, and adjacent electrodes that should not be connected are electrically connected via a plurality of conductive particles. Can be suppressed. For this reason, the conduction | electrical_connection reliability between the electrodes in a connection structure can be improved.

  The manufacturing method of the connection structure according to the present invention and the anisotropic conductive material according to the present invention relate to connection between a semiconductor chip and a glass substrate (COG (Chip on Glass)). In the manufacturing method of the connection structure according to the present invention and the anisotropic conductive material according to the present invention, a semiconductor chip and a glass substrate are used as the first connection target member and the second connection target member. In COG applications, since L / S is a relatively narrow pitch, if the anisotropically conductive material is not sufficiently fluid when heated, the anisotropically conductive material is not sufficiently filled between electrode lines. In many cases, the reliability of conduction and the generation of voids in the cured product layer become problems. On the other hand, by the manufacturing method of the connection structure according to the present invention and the anisotropic conductive material according to the present invention, in the COG application, the conduction reliability between the electrodes can be effectively increased, and in the cured product layer Generation of voids can be effectively suppressed.

  The anisotropic conductive material may be a paste-like anisotropic conductive paste or a film-like 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.

  When the anisotropic conductive paste is used, the conductive particles tend to flow and the conduction reliability tends to be lower than when the anisotropic conductive film is used. Even if an anisotropic conductive paste is used, the conduction reliability can be sufficiently enhanced by the method for manufacturing a connection structure according to the present invention and the anisotropic conductive material according to the present invention.

  The anisotropic conductive material includes a thermosetting component and conductive particles. The thermosetting component preferably contains a thermosetting compound and a thermosetting agent. The thermosetting agent is preferably a thermal anionic curing agent. The anisotropic conductive material according to the present invention preferably further contains a photocurable component in addition to the thermosetting component and the conductive particles. The photocurable component preferably contains a photocurable compound and a photocuring initiator. The photocuring initiator is preferably a photoradical initiator. The anisotropic conductive material preferably contains a thermosetting compound as a curable compound, and further contains a photocurable compound. The thermosetting compound is preferably a compound having an epoxy group or a thiirane group. The photocurable compound is preferably a compound having a (meth) acryloyl group.

By using an anisotropic conductive material comprising a compound having an epoxy group or thiirane group, a compound having a (meth) acryloyl group, a thermosetting agent, a photocuring initiator, and conductive particles, the above storage elastic modulus G ′ ₂₅ and the minimum loss elastic modulus G ″ _min can be easily controlled to preferable values, and the conduction reliability between the electrodes in the connection structure can be further enhanced. Furthermore, the use of an anisotropic conductive material comprising a compound having an epoxy group or thiirane group, a compound having a (meth) acryloyl group, a thermosetting agent, a photoradical initiator, and conductive particles, allows the storage. The elastic modulus G ′ ₂₅ and the minimum loss elastic modulus G ″ _min can be more easily controlled by preferable values, and the conduction reliability between the electrodes in the connection structure can be further enhanced. Furthermore, by using an anisotropic conductive material comprising a compound having an epoxy group or thiirane group, a compound having a (meth) acryloyl group, a thermal anion curing agent, a photo radical initiator, and conductive particles, The storage elastic modulus G ′ ₂₅ and the minimum loss elastic modulus G ″ _min can be more easily controlled with preferable values, and the conduction reliability between the electrodes in the connection structure can be further effectively improved.

From the viewpoint of easily controlling the storage elastic modulus G ′ ₂₅ and the minimum loss elastic modulus G ″ _min to preferable values and further improving the conduction reliability between the electrodes in the connection structure, the anisotropic conductive material is It is preferable to include a curable compound having a weight average molecular weight of 500 or more and 5000 or less.

  Hereinafter, each component included in the anisotropic conductive material and details of each component preferably included will be described.

[Thermosetting compound]
The thermosetting compound has thermosetting properties. As for the said thermosetting compound, only 1 type may be used and 2 or more types may be used together.

  Examples of the thermosetting compound include oxetane compounds, 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 enhancing the conduction reliability in the connection structure, the thermosetting compound is a thermosetting compound having an epoxy group or a thiirane group. It is preferable that a thermosetting compound having a thiirane group is included. The thermosetting compound having an epoxy group is an epoxy compound. The thermosetting compound having a thiirane group is an episulfide compound. From the viewpoint of enhancing the curability of the anisotropic conductive material, the content of the compound having the epoxy group or thiirane group is preferably 10% by weight or more, more preferably 20% by weight in 100% by weight of the thermosetting compound. % Or more and 100% by weight or less. The total amount of the thermosetting compound may be a compound having the epoxy group or thiirane group.

  Since the episulfide compound has a thiirane group instead of an epoxy group, it can be quickly cured 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.

  The thermosetting compound having an epoxy group or thiirane group preferably has an aromatic ring. Examples of the aromatic ring include a benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, tetracene ring, chrysene ring, triphenylene ring, tetraphen ring, pyrene ring, pentacene ring, picene ring, and perylene ring. Especially, it is preferable that the said aromatic ring is a benzene ring, a naphthalene ring, or an anthracene ring, and it is more preferable that it is a benzene ring or a naphthalene ring. A naphthalene ring is preferred because it has a planar structure and can be cured more rapidly.

  The thermosetting compound may contain a phenoxy resin. In this case, you may use together a phenoxy resin and the thermosetting compound which has the said epoxy group or thiirane group. In this case, it is preferable that the thermosetting compound having the epoxy group or thiirane group is not a phenoxy resin.

From the viewpoint of easily controlling the storage elastic modulus G ′ ₂₅ and the minimum loss elastic modulus G ″ _min to preferable values and further improving the conduction reliability between the electrodes in the connection structure, the weight average of the phenoxy resin is used. The molecular weight is preferably 20000 or more, and preferably 70000 or less.

  In this specification, the said weight average molecular weight shows the weight average molecular weight in polystyrene conversion measured by gel permeation chromatography (GPC).

  When the phenoxy resin and the thermosetting compound having the epoxy group or thiirane group are used in combination, the anisotropic conductive material includes the phenoxy resin and the thermosetting compound having the epoxy group or thiirane group. Is preferably included at a weight ratio of 1:99 to 99: 1, more preferably 10:90 to 90:10, still more preferably 20:80 to 80:20, and 30:70 to It is particularly preferred to include at 70:30.

[Photocurable compound]
The anisotropic conductive material preferably contains a photocurable compound so as to be cured by irradiation with light. By photoirradiation, the photocurable compound can be semi-cured (B-staged) to reduce the fluidity of the curable compound.

  The photocurable compound is not particularly limited, and examples thereof include a photocurable compound having a (meth) acryloyl group and a photocurable compound having a cyclic ether group.

  The photocurable compound is preferably a photocurable compound having a (meth) acryloyl group. By using the photocurable compound having a (meth) acryloyl group, the conduction reliability between the electrodes can be further enhanced. From the viewpoint of effectively increasing the conduction reliability between the electrodes, the photocurable compound preferably has one or two (meth) acryloyl groups.

  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.

  As a photocurable compound having the above (meth) acryloyl group, an ester compound obtained by reacting a compound having (meth) acrylic acid and a hydroxyl group, an epoxy obtained by reacting (meth) acrylic acid and an epoxy compound. (Meth) acrylate or urethane (meth) acrylate obtained by reacting a (meth) acrylic acid derivative having a hydroxyl group with isocyanate 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.

  As the photocurable compound, a modified phenoxy resin obtained by converting a part of epoxy groups or a part of thiirane groups of a phenoxy resin having two or more epoxy groups or two or more thiirane groups into (meth) acryloyl groups is used. Also 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.

  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, glycerine 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 (Meth) acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate, tridecyl (meth) acrylate, tetradecyl (meth) acrylate, and the like.

  When using a photocurable compound, the compounding ratio of a photocurable compound and a thermosetting compound is suitably adjusted according to the kind of a photocurable compound and a thermosetting compound. The anisotropic conductive material preferably contains a photocurable compound and a thermosetting compound in a weight ratio of 1:99 to 90:10, more preferably 5:95 to 70:30, More preferably, it is included at 10:90 to 50:50. The anisotropic conductive material particularly preferably contains the photocurable compound and the thermosetting compound in a weight ratio of 1:99 to 50:50.

(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.

  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 thereof 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. The content of the thermosetting agent with respect to 100 parts by weight of the thermosetting compound in the curable compound is preferably 5 parts by weight or more, more preferably 10 parts by weight or more, and preferably 40 parts by weight or less. The amount is preferably 30 parts by weight or less, more preferably 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.

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

  Specific examples of the acetophenone photoradical 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 photoradical initiator include benzyldimethyl ketal.

  The content of the photocuring initiator is not particularly limited. The content of the photocuring initiator with respect to 100 parts by weight of the photocurable compound in the curable compound is preferably 0.05 parts by weight or more, more preferably 0.15 parts by weight or more, preferably 2 It is 1 part by weight or less, more preferably 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 coated with a metal layer, such as organic particles, inorganic particles, organic-inorganic hybrid particles, or metal particles, or metal particles that are substantially composed of only 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 increasing the contact area between the electrode and the conductive particle and further improving the conduction reliability between the electrodes, the conductive particle includes a resin particle and a conductive layer disposed on the surface of the resin particle. It is preferable to have. From the viewpoint of further improving the conduction reliability between the electrodes, the conductive particles are preferably conductive particles having at least an outer conductive surface as a low melting point metal layer. More preferably, the conductive particles include resin particles and a conductive layer disposed on the surface of the resin particles, and at least the outer surface of the conductive layer is a low melting point metal layer.

  The low melting point metal layer is a layer containing a low melting point metal. The low melting point metal is a metal having a melting point of 450 ° C. or lower. The melting point of the low melting point metal is preferably 300 ° C. or lower, more preferably 160 ° C. or lower. The low melting point metal layer preferably contains tin. In 100% by weight of the metal contained in the low melting point metal layer, the content of tin is preferably 30% by weight or more, more preferably 40% by weight or more, still more preferably 70% by weight or more, and particularly preferably 90% by weight or more. . When the content of tin in the low melting point metal layer is not less than the above lower limit, the connection reliability between the low melting point metal layer and the electrode is further enhanced. The tin content is determined using a high frequency inductively coupled plasma optical emission spectrometer (“ICP-AES” manufactured by Horiba, Ltd.) or a fluorescent X-ray analyzer (“EDX-800HS” manufactured by Shimadzu). It can be measured.

  When the outer surface of the conductive layer is a low melting point metal layer, the low melting point metal layer is melted and joined to the electrodes, and the low melting point metal layer conducts between the electrodes. For example, since the low-melting point metal layer and the electrode are not in point contact but in surface contact, the connection resistance is lowered. In addition, the use of conductive particles having at least the outer surface of a low-melting-point metal layer increases the bonding strength between the low-melting-point metal layer and the electrode. , The conduction reliability is effectively increased.

  The low melting point metal which comprises the said low melting metal layer is not specifically limited. The low melting point metal is preferably tin or an alloy containing tin. Examples of the alloy include a tin-silver alloy, a tin-copper alloy, a tin-silver-copper alloy, a tin-bismuth alloy, a tin-zinc alloy, and a tin-indium alloy. Especially, since it is excellent in the wettability with respect to an electrode, it is preferable that the said low melting metal is a tin, a tin-silver alloy, a tin-silver-copper alloy, a tin-bismuth alloy, and a tin-indium alloy. More preferred are a tin-bismuth alloy and a tin-indium alloy.

  The low melting point metal layer is preferably a solder layer. Although the material which comprises the said solder layer is not specifically limited, Based on JISZ3001: solvent term, it is preferable that it is a meltable material whose liquidus is 450 degrees C or less. As a composition of the said solder layer, the metal composition containing zinc, gold | metal | money, lead, copper, tin, bismuth, indium etc. is mentioned, for example. Among them, a tin-indium system (117 ° C. eutectic) or a tin-bismuth system (139 ° C. eutectic) which is low-melting and lead-free is preferable. That is, the solder layer preferably does not contain lead, and is preferably a solder layer containing tin and indium or a solder layer containing tin and bismuth.

  In order to further increase the bonding strength between the low melting point metal layer and the electrode, the low melting point metal layer is made of nickel, copper, antimony, aluminum, zinc, iron, gold, titanium, phosphorus, germanium, tellurium, cobalt, bismuth. Further, it may contain a metal such as manganese, chromium, molybdenum and palladium. From the viewpoint of further increasing the bonding strength between the low melting point metal and the electrode, the low melting point metal preferably contains nickel, copper, antimony, aluminum, or zinc. From the viewpoint of further increasing the bonding strength between the low melting point metal layer and the electrode, the content of these metals for increasing the bonding strength is 100 wt% of the low melting point metal layer, preferably 0.0001 wt% or more, Preferably it is 1 weight% or less.

  The conductive particles include resin particles and a conductive layer disposed on the surface of the resin particles, and the outer surface of the conductive layer is a low melting point metal layer (such as a solder layer). In addition to the low melting point metal layer, a second conductive layer is preferably provided between the low melting point metal layer and the low melting point metal layer. In this case, the low melting point metal layer is a part of the entire conductive layer, and the second conductive layer is a part of the entire conductive layer.

  The second conductive layer different from the low melting point metal layer preferably contains a metal. The metal constituting the second conductive layer is not particularly limited. Examples of the metal include gold, silver, copper, platinum, palladium, zinc, lead, aluminum, cobalt, indium, nickel, chromium, titanium, antimony, bismuth, germanium and cadmium, and alloys thereof. Further, tin-doped indium oxide (ITO) may be used as the metal. As for the said metal, only 1 type may be used and 2 or more types may be used together.

  The second conductive layer is preferably a nickel layer, a palladium layer, a copper layer, or a gold layer, more preferably a nickel layer or a gold layer, and even more preferably a copper layer. The conductive particles preferably have a nickel layer, a palladium layer, a copper layer, or a gold layer, more preferably have a nickel layer or a gold layer, and still more preferably have a copper layer. By using the conductive particles having these preferable conductive layers for the connection between the electrodes, the connection resistance between the electrodes is further reduced. In addition, a low melting point metal layer can be more easily formed on the surface of these preferable conductive layers. The second conductive layer may be a low melting point metal layer such as a solder layer. The conductive particles may have a plurality of low melting point metal layers.

  The thickness of the low melting point metal layer is preferably 0.1 μm or more, more preferably 0.5 μm or more, still more preferably 1 μm or more, preferably 50 μm or less, more preferably 10 μm or less, still more preferably 5 μm or less, particularly preferably. 3 μm or less. When the thickness of the low melting point metal layer is not less than the above lower limit, the conductivity is sufficiently high. When the thickness of the low melting point metal layer is not more than the above upper limit, the difference in thermal expansion coefficient between the resin particles and the low melting point metal layer becomes small, and the low melting point metal layer is hardly peeled off.

  When the conductive layer is a conductive layer other than the low melting point metal layer, or when the conductive layer has a multilayer structure, the total thickness of the conductive layer is preferably 0.1 μm or more, more preferably 0.5 μm or more, Preferably it is 1 micrometer or more, Preferably it is 50 micrometers or less, More preferably, it is 10 micrometers or less, More preferably, it is 5 micrometers or less, Most preferably, it is 3 micrometers or less.

  The average particle diameter of the conductive particles is preferably 100 μm or less, more preferably 20 μm or less, still more preferably 15 μm or less, and particularly preferably 10 μm or less. The particle diameter of the conductive particles is preferably 0.5 μm or more, more preferably 1 μm or more.

  Since the size is suitable for the conductive particles in the anisotropic conductive material and the distance between the electrodes can be further reduced, the average particle diameter of the conductive particles is in the range of 1 μm to 100 μm. Is particularly preferred.

  The resin particles can be properly used depending on the electrode size or land diameter of the substrate to be mounted.

  From the viewpoint of more reliably connecting the upper and lower electrodes and further suppressing the short circuit between the electrodes adjacent in the lateral direction, the ratio of the average particle diameter C of the conductive particles to the average particle diameter A of the resin particles ( C / A) is more than 1.0, preferably 3.0 or less. In addition, when the second conductive layer is present between the resin particles and the solder layer, the ratio of the resin particles to the average particle size B with respect to the average particle size B of the conductive particle portion excluding the solder layer (B / A) is greater than 1.0, preferably 2.0 or less. Further, when there is the second conductive layer between the resin particles and the solder layer, the average particle diameter B of the conductive particle portion excluding the solder layer having the average particle diameter C of the conductive particles including the solder layer. The ratio (C / B) to is more than 1.0, preferably 2.0 or less. When the ratio (B / A) is within the above range or the ratio (C / B) is within the above range, electrodes that are more reliably connected between the upper and lower electrodes and that are adjacent in the lateral direction The short circuit between them can be further suppressed.

  The “average particle size” of the conductive particles indicates a number average particle size. 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 surface of the conductive particles may be insulated with an insulating material, insulating particles, flux, or the like. It is preferable that the insulating material, the insulating particles, the flux, and the like are removed from the connection portion by being softened and flowed by heat at the time of connection. Thereby, the short circuit between electrodes can be suppressed.

  The content of the conductive particles is not particularly limited. The content of the conductive particles in 100% by weight of the anisotropic conductive material is preferably 0.1% by weight or more, more preferably 0.5% by weight or more, preferably 40% by weight or less, more preferably 30% by weight. % Or less, more preferably 20% by weight or less, particularly preferably 19% by weight or less, and most preferably 10% 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.

(Other ingredients)
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.

  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 anisotropic conductive paste 5 parts by weight of an epoxy compound ("EP-201P" manufactured by Nagase ChemteX), which is a thermosetting compound, and an epoxy compound ("EPICLON HP" manufactured by DIC) -4032D ") 10 parts by weight, 4 parts by weight of an amine adduct of imidazole as a thermosetting agent (" PN-F "manufactured by Ajinomoto Fine Techno Co.), and epoxy acrylate (Daicel Cytec Co., Ltd.) as a photocurable compound "EBECRYL 3608") 8 parts by weight, acylphosphine oxide compound (BASF Japan "IRGACURE TPO") 0.1 parts by weight, and a curing accelerator 2-ethyl-4- 1 part by weight of methylimidazole and 10 parts by weight of alumina (average particle size 0.5 μm) as a filler Furthermore, after adding conductive particles A (average particle size 3 μm) so that the content in 100% by weight of the composition is 10% by weight, the mixture is stirred for 5 minutes at 2000 rpm using a planetary stirrer. Thus, an anisotropic conductive paste was obtained.

  The conductive particles A 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. It is.

(2) Production of Connection Structure A transparent glass substrate (first connection target member) having an Al-4% Ti electrode pattern with an L / S of 15 μm / 15 μm formed on the upper surface was prepared. A semiconductor chip (second connection target member) having a copper electrode pattern with an L / S of 15 μm / 15 μm and an electrode area per electrode of 1500 μm ² formed on the lower surface was prepared.

  On the said transparent glass substrate, the obtained anisotropic conductive paste was applied so that thickness might be set to 30 micrometers, and the anisotropic conductive paste layer was formed.

Next, using an LED lamp with a wavelength of 365 nm, the anisotropic conductive paste layer is irradiated with ultraviolet rays from above so that the irradiation energy is 2000 mJ / cm ^2, and the anisotropic conductive paste layer is semi-cured by photopolymerization. The B-staged anisotropic conductive paste layer (an anisotropic conductive paste layer before main curing) was formed. Next, the semiconductor chip was stacked on the B-staged anisotropic conductive paste layer so that the electrodes face each other. Then, while adjusting the temperature of the head so that the temperature of the B-staged anisotropic conductive paste layer becomes 185 ° C., a pressure heating head is placed on the upper surface of the semiconductor chip and is anisotropically applied with a pressure of 3 MPa. The conductive paste layer was fully cured at 185 ° C. to obtain a connection structure.

(Examples 2 to 4)
When producing the connection structure, the connection structure was prepared in the same manner as in Example 1 except that the anisotropic conductive paste layer was irradiated with ultraviolet rays from above so that the irradiation energy shown in Table 1 was obtained. Obtained.

(Example 5)
(1) Preparation of anisotropic conductive film 15 parts by weight of phenoxy resin ("PKHC" manufactured by Inchem, weight average molecular weight 43000) which is a thermosetting compound, and epoxy compound (manufactured by Nagase ChemteX Corporation) which is a thermosetting compound 5 parts by weight of "EP-201P"), 10 parts by weight of an epoxy compound ("EPICLON HP-4032D" manufactured by DIC) that is a thermosetting compound, and an amine adduct of imidazole that is a thermosetting agent (Ajinomoto Fine Techno Co., Ltd.) "PN-F") 4 parts by weight and 1 part by weight of 2-ethyl-4-methylimidazole as a curing accelerator were blended, and the conductive particles A used in Example 1 were mixed in 100% by weight. After adding toluene as a solvent so that the solid content becomes 35% by weight, using a planetary stirrer By stirring for 5 minutes at 000 rpm, to obtain a composition.

  After coating the obtained composition on the polyethylene terephthalate film subjected to the mold release treatment, the solvent was removed by vacuum drying at 80 ° C. for 15 minutes to obtain an anisotropic conductive film having a thickness of 30 μm.

(2) Production of Connection Structure A transparent glass substrate (first connection target member) having an Al-4% Ti electrode pattern with an L / S of 15 μm / 15 μm formed on the upper surface was prepared. A semiconductor chip (second connection target member) having a copper electrode pattern with an L / S of 15 μm / 15 μm and an electrode area per electrode of 1500 μm ² formed on the lower surface was prepared.

  The obtained anisotropic conductive film was placed on the glass substrate to form an anisotropic conductive film layer, and then the PET film was peeled off. After forming the anisotropic conductive film layer, the anisotropic conductive film layer was not irradiated with light.

  Next, the semiconductor chip was laminated on the anisotropic conductive film layer so that the electrodes face each other. Then, while adjusting the temperature of the head so that the temperature of the anisotropic conductive film layer becomes 185 ° C., a pressure heating head is placed on the upper surface of the semiconductor chip and a pressure of 3 MPa is applied to form the anisotropic conductive film layer. The film was fully cured at 185 ° C. to obtain a connection structure.

(Example 6)
Except for changing the phenoxy resin ("PKHC" manufactured by Inchem, weight average molecular weight 43000) to the phenoxy resin ("PKHH" manufactured by Inchem, weight average molecular weight 57000) when preparing the anisotropic conductive film. In the same manner as in Example 5, an anisotropic conductive film was obtained. A connection structure was obtained in the same manner as in Example 5 except that the obtained anisotropic conductive film was used.

(Example 7)
When preparing the anisotropic conductive film, the phenoxy resin (“PKHC” manufactured by Inchem, weight average molecular weight 43000) was changed to the phenoxy resin (“YP-50” manufactured by Tohto Kasei Co., Ltd., weight average molecular weight 70000). Except that, an anisotropic conductive film was obtained in the same manner as Example 5. A connection structure was obtained in the same manner as in Example 5 except that the obtained anisotropic conductive film was used.

(Examples 8 to 14)
Divinylbenzene resin particles having an average particle size of 3 μm (“Micropearl SP-203” manufactured by Sekisui Chemical Co., Ltd.) were subjected to electroless nickel plating to form a base nickel plating layer having a thickness of 0.1 μm on the surface of the resin particles. Subsequently, the resin particles on which the base nickel plating layer was formed were subjected to electrolytic copper plating to form a copper layer having a thickness of 0.5 μm. Furthermore, electrolytic plating was performed using an electrolytic plating solution containing tin and bismuth to form a solder layer having a thickness of 1 μm. Thus, a 1 μm thick copper layer is formed on the surface of the resin particles, and a 3 μm thick solder layer (tin: bismuth = 43 wt%: 57 wt%) is formed on the surface of the copper layer. Conductive particles B were prepared.

  In Example 8, an anisotropic conductive paste and a connection structure were obtained in the same manner as in Example 1 except that the conductive particles A were changed to the conductive particles B.

  In Example 9, an anisotropic conductive paste and a connection structure were obtained in the same manner as in Example 2 except that the conductive particles A were changed to the conductive particles B.

  In Example 10, an anisotropic conductive paste and a connection structure were obtained in the same manner as in Example 3 except that the conductive particles A were changed to the conductive particles B.

  In Example 11, an anisotropic conductive paste and a connection structure were obtained in the same manner as in Example 4 except that the conductive particles A were changed to the conductive particles B.

  In Example 12, an anisotropic conductive film and a connection structure were obtained in the same manner as in Example 5 except that the conductive particles A were changed to the conductive particles B.

  In Example 13, an anisotropic conductive film and a connection structure were obtained in the same manner as in Example 6 except that the conductive particles A were changed to the conductive particles B.

  In Example 14, an anisotropic conductive film and a connection structure were obtained in the same manner as in Example 7 except that the conductive particles A were changed to the conductive particles B.

(Comparative Examples 1-2)
When producing the connection structure, the connection structure was prepared in the same manner as in Example 1 except that the anisotropic conductive paste layer was irradiated with ultraviolet rays from above so that the irradiation energy shown in Table 1 was obtained. Obtained.

(Comparative Example 3)
When preparing the anisotropic conductive film, the phenoxy resin (“PKHC” manufactured by Inchem, weight average molecular weight 43000) was changed to phenoxy resin (“PKHB” manufactured by Inchem, weight average molecular weight 32000). In the same manner as in Example 5, an anisotropic conductive film was obtained. A connection structure was obtained in the same manner as in Example 5 except that the obtained anisotropic conductive film was used.

(Comparative Example 4)
When preparing the anisotropic conductive film, the compounding amount of the phenoxy resin (“YP-50” manufactured by Toto Kasei Co., Ltd., weight average molecular weight 70000) was changed to 25 parts by weight, and the epoxy compound which is a thermosetting compound An anisotropic conductive film was obtained in the same manner as in Example 7 except that (EPICLON HP-4032D manufactured by DIC) was not blended. A connection structure was obtained in the same manner as in Example 5 except that the obtained anisotropic conductive film was used.

(Evaluation)
(1) Storage elastic modulus G ′ ₂₅ at 25 ° C.
The anisotropic conductive material layer before the main curing at the time of producing the connection structure is laminated using a laminator heated to 50 ° C., a measurement sample having a thickness of 500 μm or more is produced, and the storage elastic modulus at 25 ° C. It was measured G _'25. Using a rotary dynamic viscoelastic device (“VAR-100” manufactured by Rheology Instruments Inc.), measurement was performed under the conditions of a frequency of 1 Hz, a strain of 1.0E-2, and a measurement temperature of 25 ° C.

(2) Minimum loss modulus G '' _min
The anisotropic conductive material layer before the main curing during the production of the connection structure was laminated using a laminator heated to 50 ° C., and a measurement sample having a thickness of 500 μm or more was produced. The obtained sample was heated from 25 ° C. to 250 ° C., and the minimum loss modulus G ″ _min was measured. Using a rotary dynamic viscoelastic device (“VAR-100” manufactured by Rheology Instrument Co., Ltd.) at a frequency of 1 Hz and a strain of 1.0E-2, and from 25 ° C. to 250 ° C., a temperature rising rate of 5 ° C./min. The measurement was performed under the conditions of heating at The value with the smallest loss elastic modulus G ″ was defined as the minimum loss elastic modulus G ″ _min .

(3) Indentation state About the connection part of 100 electroconductive particles and an electrode in the obtained connection structure, the state of the indentation formed in the electrode was observed.

Using a polarizing microscope, it was judged that good indentation was formed when an average of 25 or more spherical indentations per electrode (per 1500 μm ² ) could be confirmed. Moreover, it was judged that formation of an indentation was inadequate when the average of less than five spherical indentations per electrode (per 1500 μm ² ) could be confirmed. The indentation state was determined according to the following criteria.

[Indentation state]
◯: On average, 25 or more obvious spherical indentations in 100 connected portions ○: On average, 5 or more, less than 25 apparent spherical indentations in 100 connected portions ×: 100 connected portions Inside, there are less than 5 obvious spherical indentations on average

(4) Presence / absence of voids (fillability)
In the obtained connection structure, whether or not voids are generated in the cured product layer formed by the anisotropic conductive material layer is measured with an optical microscope from the lower surface side of the transparent glass substrate. The generation area was calculated and judged according to the following criteria.

[Criteria for the presence or absence of voids]
○○: The generation area of voids is less than 2.5% ○: The generation area of voids is 2.5% or more and less than 5% ×: The generation area of voids is 5% or more, or There are voids with a size of 20 μm or more

(5) Connection resistance The connection resistance between the upper and lower electrodes of the obtained 20 connection structures was measured by a four-terminal method. The average value of the connection resistance of 20 connection structures was determined. Note that the connection resistance can be obtained by measuring the voltage when a constant current is passed from the relationship of voltage = current × resistance. Connection resistance was determined according to the following criteria.

[Criteria for connection resistance]
○○: The average value of connection resistance is less than 3Ω ○: The average value of connection resistance exceeds 3Ω and 5Ω or less ×: The average value of connection resistance exceeds 5Ω, or there is a connection structure that cannot be measured

  The results are shown in Table 1 below.

  In addition, Example 1 and Example 8, Example 2 and Example 9, Example 3 and Example 10, Example 4 and Example 11, Example 5 and Example 12, Example 6 and Example 13, As a result of comparing Example 7 and Example 14, when conductive particles whose outer surface of the conductive layer is a low melting point metal layer are used, the conductive particles whose outer surface of the conductive layer is not a low melting point metal layer are used. It was confirmed that the connection reliability in the connection structure was higher than that when using. This is because the low melting point metal layer wets and spreads on the electrode surface at the time of pressure bonding, and the low melting point metal solidified after melting is firmly connected to the electrode.

DESCRIPTION OF SYMBOLS 1 ... Connection structure 2 ... 1st connection object member 2a ... Upper surface 2b ... Electrode 2c ... Recessed part (indentation)
DESCRIPTION OF SYMBOLS 3 ... Hardened | cured material layer 3a ... Upper surface 3A ... Anisotropic electrically-conductive material layer 3B ... B-staged anisotropic electrically-conductive material layer 4 ... 2nd connection object member 4a ... Lower surface 4b ... Electrode 5 ... Conductive particle

Claims (12)

A method for manufacturing a connection structure for connecting a semiconductor chip and a glass substrate,
Disposing an anisotropic conductive material layer using an anisotropic conductive material including a thermosetting component and conductive particles on a first connection target member having an electrode on an upper surface;
Laminating a second connection object member having an electrode on the lower surface on the upper surface of the anisotropic conductive material layer;
The anisotropic conductive material layer is heated to be fully cured to form a cured product layer,
The anisotropic conductive material layer before main curing has a storage elastic modulus G ′ ₂₅ at 25 ° C. of 1 × 10 ⁵ Pa or more and 1 × 10 ⁷ Pa or less, and the anisotropic conductive material layer before main curing is The minimum loss elastic modulus G ″ _min when heated from 25 ° C. to 250 ° C. is set to 5 × 10 ² Pa or more and 1 × 10 ⁵ Pa or less,
A method for manufacturing a connection structure, wherein a semiconductor chip and a glass substrate are used as the second connection target member and the first connection target member. Before the main curing, further comprising the step of forming a B-staged anisotropic conductive material layer by applying heat or irradiating light to the anisotropic conductive material layer to advance the curing,
The anisotropic conductive material layer before main curing is a B-staged anisotropic conductive material layer,
When the anisotropic conductive material layer is irradiated with light, an anisotropic conductive material including a thermosetting component, a photocurable component, and conductive particles is used as the anisotropic conductive material. A manufacturing method of the connection structure according to 1. Before the main curing, further comprising a step of forming a B-staged anisotropic conductive material layer by proceeding with curing by irradiating the anisotropic conductive material layer with light,
The anisotropic conductive material layer before main curing is a B-staged anisotropic conductive material layer,
The manufacturing method of the connection structure of Claim 1 using the anisotropic conductive material containing a thermosetting component, a photocurable component, and electroconductive particle as said anisotropic conductive material.   An anisotropic conductive material comprising a compound having an epoxy group or thiirane group, a compound having a (meth) acryloyl group, a thermosetting agent, a photocuring initiator, and conductive particles as the anisotropic conductive material. The manufacturing method of the connection structure of any one of Claims 1-3 using.   An anisotropic conductive material comprising a compound having an epoxy group or thiirane group, a compound having a (meth) acryloyl group, a thermosetting agent, a photo radical initiator, and conductive particles as the anisotropic conductive material. The manufacturing method of the connection structure of Claim 4 which uses this.   The method for manufacturing a connection structure according to claim 1, wherein an anisotropic conductive paste is used as the anisotropic conductive material. An anisotropic conductive material used to connect a semiconductor chip and a glass substrate,
It is used for the purpose of heating and curing the B-staged anisotropic conductive material after forming the B-staged anisotropic conductive material by curing by applying heat or irradiating light. ,
Including a thermosetting component and conductive particles;
The storage elastic modulus G ′ ₂₅ at 25 ° C. is 1 × 10 ⁵ Pa or more and 1 × 10 ⁷ Pa or less, and the minimum loss elastic modulus G ″ _min when heated from 25 ° C. to 250 ° C. is 5 × 10 ² Pa or more state, and are 1 × ¹⁰ 5 Pa or less,
Minimum loss of the 25 ° C. storage modulus G at _'25, the storage modulus G at 25 ° C. of B-staged anisotropic conductive material' is _25, when heated from the 25 ° C. to 250 ° C. The elastic modulus G ″ _min is the minimum loss elastic modulus G ″ _min when the B-staged anisotropic conductive material is heated from 25 ° C. to 250 ° C. ,
An anisotropic conductive material comprising a thermosetting component, a photocurable component, and conductive particles in the case of an anisotropic conductive material that is cured by light irradiation . After curing by light irradiation to form a B-staged anisotropic conductive material, the B-staged anisotropic conductive material is used for heating and main curing ,
And a thermosetting component and a photocurable component and conductive particles, an anisotropic conductive material according to claim 7. The anisotropic conductivity according to claim 7 or 8 , comprising a compound having an epoxy group or thiirane group, a compound having a (meth) acryloyl group, a thermosetting agent, a photocuring initiator, and conductive particles. material. The anisotropic conductive material of Claim 9 containing the compound which has an epoxy group or thiirane group, the compound which has a (meth) acryloyl group, a thermosetting agent, a photoradical initiator, and electroconductive particle. The anisotropic conductive material according to any one of claims 7 to 10 , which is an anisotropic conductive paste. A first connection target member having an electrode on the upper surface;
A second connection target member having an electrode on the lower surface;
A cured product layer connecting the first connection target member and the second connection target member;
The cured product layer is formed by heating and anisotropically curing the anisotropic conductive material according to any one of claims 7 to 11 ,
A connection structure in which the second connection target member and the first connection target member are a semiconductor chip and a glass substrate.

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