JP2013030413A - Manufacturing method of connection structure and connection structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a connection structure and a connection structure, capable of enhancing insulation reliability when electrodes of a member to be connected are connected.SOLUTION: The manufacturing method of a connection structure 11 comprises: a step of laminating an insulator layer 6A so as to cover a plurality of first electrodes 2b on the plurality of the first electrodes 2b and gaps X between the plurality of the first electrodes 2b using a first member to be connected 2 having the plurality of the first protruded electrodes 2b on a surface 2a; a step of laminating an anisotropic conductive paste layer 3A by coating an anisotropic conductive paste containing a curable component and a conductive particle on a surface 6a opposite to the first member to be connected 2 of the insulator layer 6A; a B-stage obtaining step which forms a B-stage obtaining anisotropic conductive layer 3B by ether removing a solvent of the anisotropic conductive paste layer 3A or promoting curing.

Description

  The present invention electrically connects electrodes of various connection target members such as a flexible printed circuit board, a glass substrate, a glass epoxy substrate, and a semiconductor chip using an anisotropic conductive paste containing a plurality of conductive particles. The present invention relates to a connection structure manufacturing method and a 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.

  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 below, a protruding electrode formed to protrude on a main surface of an electronic component is connected to a connection electrode formed on a mounting substrate, and the main structure is described above. A method of manufacturing a connection structure is disclosed in which the electronic component is mounted on the mounting substrate with the surface facing the mounting substrate. The manufacturing method of the connection structure described in Patent Document 1 is an electronic component preparation step of preparing the electronic component in which an insulating adhesive layer is formed on the main surface so as to embed the protruding electrode on the main surface. A mounting substrate preparing step for forming an anisotropic conductive adhesive layer including an insulating adhesive base material and conductive particles dispersed in the adhesive base material on the mounting substrate; and the electronic component preparation. An electronic component crimping step of pressurizing and crimping the electronic component prepared in the step and the mounting substrate prepared in the mounting substrate preparing step. In the electronic component preparation step, the insulating adhesive layer of the electronic component is formed to a thickness substantially the same as the height of the protruding electrode. In the mounting substrate preparation step, the anisotropic conductive adhesive layer is formed to have substantially the same thickness as the particle size of the conductive particles.

JP 2009-147231 A

  In the conventional manufacturing method of the connection structure as described in Patent Document 1, the thickness of the insulating adhesive layer is substantially the same as the height of the protruding electrode so as to embed the protruding electrode on the main surface, and different. The thickness of the one-way conductive adhesive layer is substantially the same as the particle size of the conductive particles. For this reason, the flow of the insulating adhesive layer and the anisotropic conductive adhesive layer hardly occurs in the crimping process. As a result, it is difficult to eliminate voids generated between the insulating adhesive layer and the anisotropic conductive adhesive layer, or between the protruding electrode and the anisotropic conductive adhesive layer. It is difficult to obtain reliability.

  The objective of this invention is providing the manufacturing method of a connection structure which can improve insulation reliability, and a connection structure, when the electrodes of a connection object member are connected.

  According to a wide aspect of the present invention, a gap between a plurality of first electrodes and a plurality of first electrodes is formed using a first connection target member having a plurality of protruding first electrodes on the surface. And a step of laminating an insulating layer so as to cover the plurality of first electrodes, and a curable component and conductive particles on the surface of the insulating layer opposite to the first connection target member side. An anisotropic conductive paste including the step of laminating an anisotropic conductive paste layer, and removing the solvent of the anisotropic conductive paste layer or proceeding with curing to form a B-stage anisotropic The manufacturing method of a connection structure provided with the B-staging process which forms a conductive conductive layer is provided.

  In a specific aspect of the manufacturing method of the connection structure according to the present invention, a plurality of the anisotropic conductive paste layer or the B-staged anisotropic conductive layer on the surface opposite to the insulating layer side, The method further includes the step of laminating the second connection target member having the second electrode on the surface, with the plurality of first electrodes and the plurality of second electrodes facing each other.

  In another specific aspect of the method for manufacturing a connection structure according to the present invention, the B-staged anisotropic conductive layer is fully cured to form a cured product layer, and the cured product layer is used to form the first and second layers. A main curing step of electrically connecting the connection target members of the insulating layer portion between the first electrode and the conductive particles contained in the B-staged anisotropic conductive layer; And the conductive particles are brought into contact with the first and second electrodes.

  In still another specific aspect of the method for manufacturing a connection structure according to the present invention, a semiconductor wafer is used as the first connection target member.

  In another specific aspect of the method for manufacturing a connection structure according to the present invention, a semiconductor wafer is used as the first connection target member, and each semiconductor chip is a semiconductor wafer after being divided by cutting the semiconductor wafer. The process of making is further provided.

  In still another specific aspect of the method for manufacturing a connection structure according to the present invention, the first electrode is a copper electrode.

  In another specific aspect of the method for producing a connection structure according to the present invention, the curable component contained in the anisotropic conductive paste includes a photocurable component capable of being irradiated by light and a heat curable by heating. A curable component, or a light and thermosetting component curable by both light irradiation and heating.

  In still another specific aspect of the method for manufacturing a connection structure according to the present invention, the curable component contained in the anisotropic conductive paste is light and thermosetting that can be cured by both light irradiation and heating. Contains sex ingredients.

  In another specific aspect of the method for manufacturing a connection structure according to the present invention, in the B-stage forming step, the anisotropic conductive paste is cured by irradiation with light, so that the B-stage anisotropic conductive is performed. A layer is formed, and the B-staged anisotropic conductive layer is fully cured by heating in the main curing step.

  In still another specific aspect of the method for manufacturing a connection structure according to the present invention, the anisotropic conductive paste further includes a solvent.

  Moreover, according to the wide situation of this invention, the clearance gap between the 1st connection object member which has the several 1st electrode which protruded on the surface, and the said several 1st electrode on the said several 1st electrode An insulating layer laminated on the upper surface, and a B-staged anisotropic conductive layer laminated on the surface of the insulating layer opposite to the first connection target member side, The conductive structure is formed by removing the solvent of the anisotropic conductive paste using an anisotropic conductive paste containing a curable component and conductive particles or by proceeding with curing. The body is provided.

  Moreover, according to the wide situation of this invention, the 1st connection object member which has the several 1st electrode which protruded on the surface, the one part area | region on the said 1st electrode, and the said some 1st electrode An insulating layer laminated on a gap between the insulating layer, a cured product layer laminated on the surface of the insulating layer opposite to the first connection target member side, and the insulating layer side of the cured product layer; And a second connection target member having a plurality of second electrodes on the surface, and the cured product layer includes a different component containing a curable component and conductive particles. The anisotropic conductive paste is formed by main curing using an anisotropic conductive paste, and the plurality of first electrodes and the plurality of second electrodes are electrically connected by the conductive particles. A connected connection structure is provided.

  On the specific situation with the connection structure which concerns on this invention, a said 1st connection object member is an individual semiconductor chip which is a semiconductor wafer or is a semiconductor wafer after a division | segmentation.

  In another specific aspect of the connection structure according to the present invention, the first electrode is a copper electrode.

  In still another specific aspect of the connection structure according to the present invention, the curable component contained in the anisotropic conductive paste includes a photocurable component that can be irradiated by light and a thermosetting that can be cured by heating. Components, or light and thermosetting components that are curable by both light irradiation and heating.

  In another specific aspect of the connection structure according to the present invention, the curable component contained in the anisotropic conductive paste includes a light and a thermosetting component curable by both light irradiation and heating. .

  The method for manufacturing a connection structure according to the present invention uses a first connection target member having a plurality of protruding first electrodes on the surface, and a plurality of the first electrodes and a plurality of the first electrodes. A step of laminating an insulating layer so as to cover a plurality of the first electrodes, and a surface of the insulating layer opposite to the first connection target member side; Applying an anisotropic conductive paste containing conductive particles and laminating the anisotropic conductive paste layer; removing the solvent of the anisotropic conductive paste layer or proceeding with curing; And a B-stage forming process for forming the anisotropic anisotropic conductive layer, so that a connection structure with high insulation reliability can be obtained.

  The connection structure according to the present invention includes a first connection object member having a plurality of protruding first electrodes on the surface, a plurality of the first electrodes, and a gap between the plurality of first electrodes. And a B-staged anisotropic conductive layer laminated on the surface of the insulating layer opposite to the first connection target member side, and the B-stage anisotropic The conductive conductive layer is formed by using an anisotropic conductive paste containing a curable component and conductive particles and removing the solvent of the anisotropic conductive paste or by proceeding with curing. A connection structure with high reliability can be obtained.

  The connection structure according to the present invention includes a first connection target member having a plurality of protruding first electrodes on the surface, a partial region on the first electrode, and the plurality of first electrodes. An insulating layer laminated on the gap between the insulating layer, a cured product layer laminated on the surface of the insulating layer opposite to the first connection target member side, and the insulating layer side of the cured product layer And a second connection target member having a plurality of second electrodes on the surface, the cured product layer including a curable component and conductive particles. Since the anisotropic conductive paste is formed by main-curing the anisotropic conductive paste, the insulation reliability can be improved.

FIG. 1 is a cross-sectional view schematically showing a connection structure obtained by the method for manufacturing a connection structure according to the first embodiment of the present invention. FIG. 2 is a cross-sectional view schematically showing a connection structure obtained by the method for manufacturing a connection structure according to the second embodiment of the present invention. 3A to 3C are cross-sectional views for explaining each step of the method for manufacturing the connection structure according to the first embodiment of the present invention. FIGS. 4A and 4B are cross-sectional views for explaining each step of the method for manufacturing the connection structure according to the second embodiment of the present invention.

  Details of the present invention will be described below.

  The method for manufacturing a connection structure according to the present invention uses a first connection target member having a plurality of protruding first electrodes on the surface, and a plurality of the first electrodes and a plurality of the first electrodes. A step of laminating an insulating layer so as to cover a plurality of the first electrodes, and a surface of the insulating layer opposite to the first connection target member side; Applying an anisotropic conductive paste containing conductive particles and laminating the anisotropic conductive paste layer; removing the solvent of the anisotropic conductive paste layer or proceeding with curing; And a B-stage forming step of forming a fluorinated anisotropic conductive layer. It is preferable not to dispose the B-staged anisotropic conductive layer in the gap between the plurality of first electrodes.

  Since the manufacturing method of the connection structure according to the present invention before the second connection target member is stacked has the above-described configuration, the connection with high insulation reliability is performed by stacking the second connection target members. A structure can be obtained. In particular, since an insulating layer is disposed in the gap between the plurality of first electrodes instead of the B-staged anisotropic conductive layer containing conductive particles, the conductive layer is not conductive in the gap between the plurality of first electrodes. As a result, a connection structure with high insulation reliability can be obtained.

  On the other hand, when the anisotropic conductive paste is applied directly on the surface of the connection target member having the protruding electrode on the surface as in the conventional method for manufacturing a connection structure, the conductive material is not formed in the gap between the electrodes. The conductive particles are disposed, and the conductive particles disposed on the electrodes flow and easily move to the gaps between the electrodes. For this reason, it is difficult to obtain a connection structure having high insulation reliability.

  In the method for manufacturing a connection structure according to the present invention, a plurality of second electrodes are formed on the surface of the anisotropic conductive paste layer or the B-staged anisotropic conductive layer opposite to the insulating layer side. It is preferable to further include a step of laminating the second connection target member on the surface with the plurality of first electrodes and the plurality of second electrodes facing each other. In the connection structure obtained through such steps, the insulation reliability is increased. It is preferable not to arrange a cured product layer in the gaps between the plurality of first electrodes. Before forming the B-staged anisotropic conductive layer, the second connection target member may be laminated on the surface of the anisotropic conductive paste layer. After forming the B-staged anisotropic conductive layer, the second connection target member may be laminated on the surface of the B-staged anisotropic conductive layer.

  The connection structure (laminate) according to the present invention includes a first connection target member having a plurality of protruding first electrodes on the surface, a plurality of the first electrodes, and a plurality of the first electrodes. An insulating layer laminated on the gap, and a B-staged anisotropic conductive layer laminated on the surface of the insulating layer opposite to the first connection target member side, The staged anisotropic conductive layer is formed by using an anisotropic conductive paste containing a curable component and conductive particles, by removing the solvent of the anisotropic conductive paste or by proceeding with curing. Yes. It is preferable that a B-staged anisotropic conductive layer is not disposed in the gap between the plurality of first electrodes.

  Since the connection structure according to the present invention before the second connection target member is stacked has the above-described configuration, a connection structure having high insulation reliability can be obtained by stacking the second connection target members. Can be obtained. In particular, since an insulating layer is disposed in the gap between the plurality of first electrodes instead of the B-staged anisotropic conductive layer containing conductive particles, the conductive layer is not conductive in the gap between the plurality of first electrodes. As a result, a connection structure with high insulation reliability can be obtained.

  The connection structure according to the present invention includes a first connection target member having a plurality of protruding first electrodes on the surface, a partial region on the first electrode, and the plurality of first electrodes. An insulating layer stacked on the gap between the insulating layer, a cured product layer laminated on the surface of the insulating layer opposite to the first connection target member side, and the insulating layer side of the cured product layer; Is laminated on the surface on the opposite side, and includes a second connection target member having a plurality of second electrodes on the surface. The cured product layer is formed by main curing the anisotropic conductive paste using an anisotropic conductive paste containing a curable component and conductive particles. The plurality of first electrodes and the plurality of second electrodes are electrically connected by the conductive particles. It is preferable that the hardened | cured material layer is not arrange | positioned in the clearance gap between several 1st electrodes.

  Since the connection structure according to the present invention after the second connection target member is laminated has the above configuration, the insulation reliability can be improved.

  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 the 1st Embodiment of this invention is typically shown with sectional drawing. The connection structure shown in FIG. 1 is also a connection structure according to an embodiment of the present invention.

  The connection structure 11 shown in FIG. 1 includes a first connection target member 2, an insulating layer 6A, and a B-staged anisotropic conductive layer 3B.

  The first connection target member 2 has a plurality of protruding first electrodes 2b on the surface 2a. The insulating layer 6A is stacked on the plurality of first electrodes 2b and on the gaps X between the plurality of first electrodes 2b. The gap X between the plurality of first electrodes 2b is a concave portion where there is no first electrode 2b.

  The B-staged anisotropic conductive layer 3B is laminated on the surface 6a opposite to the first connection target member 2 side of the insulating layer 6A. The B-staged anisotropic conductive layer 3B uses an anisotropic conductive paste containing a curable component and conductive particles 5 to remove the solvent of the anisotropic conductive paste (anisotropic conductive paste layer). Or it is formed by advancing hardening. The B-staged anisotropic conductive layer 3B may be formed by removing the solvent of the anisotropic conductive paste layer after forming the anisotropic conductive paste layer, and curing the anisotropic conductive paste layer. You may form by making it advance. The B-staged anisotropic conductive layer 3B is preferably formed by advancing curing of the anisotropic conductive paste layer. In the gap X between the plurality of first electrodes 2b, the B-staged anisotropic conductive layer 3B is not disposed. When forming the B-staged anisotropic conductive layer 3B by removing the solvent of the anisotropic conductive paste layer, the anisotropic conductive paste contains a solvent.

  The insulating layer 6A is made of an insulating material. The insulating layer 6A does not contain conductive particles. An insulating layer 6A is disposed between the conductive particles 5 and the first electrode 2b. The insulating layer 6A insulates a plurality of adjacent first electrodes 2b in contact with the insulating layer 6A.

  In the connection structure 11, the thickness of the insulating layer 6A on the protruding first electrode 2b of the first connection target member 2 is preferably 0.1 μm or more, more preferably 1 μm or more, and further preferably 3 μm or more, preferably Is 20 μm or less, more preferably 10 μm or less, and even more preferably 5 μm or less.

  In the connection structure 11, the thickness of the B-staged anisotropic conductive layer 3 </ b> B is preferably 1.2 times or more, and preferably 2 times or more the average particle diameter of the conductive particles 5. More preferably, it is 20 times or less, more preferably 10 times or less.

  In FIG. 2, the connection structure obtained by the manufacturing method of the connection structure which concerns on the 2nd Embodiment of this invention is typically shown with sectional drawing. The connection structure shown in FIG. 2 is also a connection structure according to an embodiment of the present invention.

  A connection structure 1 shown in FIG. 2 includes a first connection target member 2, a second connection target member 4, an insulating layer 6, and a cured product layer 3.

  The insulating layer 6 is laminated on a partial region on the plurality of first electrodes 2b and on the gaps X (concave portions) between the plurality of first electrodes 2b. In the portion where the conductive particles 5 are in contact with the first electrode 2b, the insulating layer 6 is not laminated on the plurality of first electrodes 2b. The insulating layer 6 is not disposed between the plurality of first electrodes 2 b and the conductive particles 5.

  The cured product layer 3 is a connection part that electrically connects the first and second connection target members 2 and 4. The cured product layer 3 is laminated on the surface 6 a opposite to the first connection target member 2 side of the insulating layer 6. The cured product layer 3 is formed by main-curing the anisotropic conductive paste using an anisotropic conductive paste containing a curable component and the conductive particles 5. The cured product layer 3 is subjected to main curing after removing the solvent of the anisotropic conductive paste using the anisotropic conductive paste containing the curable component and the conductive particles 5 or by allowing the curing to proceed. It is preferable that it is formed by. The cured product layer 3B is not disposed in the gap X between the plurality of first electrodes 2b.

  The 2nd connection object member 4 is laminated | stacked on the surface 3a on the opposite side to the insulating layer 6 side of the hardened | cured material layer 3. As shown in FIG. The second connection target member 4 has a plurality of protruding second electrodes 4b on the surface 4a. The 1st, 2nd connection object members 2 and 4 are arrange | positioned so that the 1st electrode 2b and the 2nd electrode 4b may oppose. One or a plurality of conductive particles 5 are arranged between the first electrode 2b and the second electrode 4b. The first electrode 2b and the second electrode 4b are electrically connected by one or a plurality of conductive particles 5. Components other than the conductive particles 5 in the insulating layer 6 and the cured product layer 3 are not disposed between the plurality of first electrodes 2 b and the conductive particles 5. Components other than the conductive particles 5 in the cured product layer 3 are not disposed between the plurality of second electrodes 4 b and the conductive particles 5.

  In the connection structures 1 and 11, a semiconductor chip is used as the first connection target member 2. In the connection structure 1, a glass substrate having an electrode formed of ITO, metal or the like on the surface is used as the second connection target member 4. The first and second connection target members are not particularly limited. Specifically, the first and second connection target members include semiconductor wafers, semiconductor chips (divided semiconductor wafers), electronic components such as capacitors and diodes, printed boards, flexible printed boards, glass boards, and glass epoxies. An electronic component that is a circuit board such as a substrate is exemplified.

  The protruding height of the protruding first electrode is preferably 3 μm or more, more preferably 10 μm or more, preferably 50 μm or less, more preferably 20 μm or less. The distance between the adjacent first electrodes is preferably 4 μm or more, more preferably 8 μm or more, preferably 50 μm or less, more preferably 20 μm or less. The distance of the gap between the adjacent first electrodes is the width of the recess, and is the dimension of the portion where the first electrode is not provided. When the protruding height and the distance between the adjacent first electrodes are not less than the lower limit and not more than the upper limit, the conventional connection structure manufacturing method is not particularly provided with an insulating layer. When the connection structure is manufactured using the connection object member, the connection reliability between the electrodes tends to be particularly low. On the other hand, by producing a connection structure using the first connection object member provided with the insulating layer, the distance between the protruding height and the gap between the adjacent first electrodes is the lower limit. Even if it is above and below the above upper limit, the connection reliability can be sufficiently enhanced. In particular, even when the distance between the first electrodes is equal to or less than the upper limit, it is possible to effectively suppress electrical connection between the first electrodes adjacent in the lateral direction by the conductive particles.

  The first electrode is preferably a copper electrode. The connection resistance is lowered by using a copper electrode. On the other hand, there is a problem that the copper electrode is easily oxidized. On the other hand, the oxidation of a copper electrode can be suppressed by arrange | positioning the said insulating layer so that a copper electrode may be covered. Moreover, even if it is other than a copper electrode, by arranging the insulating layer so as to cover the first electrode, it is possible to prevent the first electrode from deteriorating due to contact with corrosive gas in the atmosphere. it can.

  The connection structure 11 shown in FIG. 1 can be obtained as follows, for example. Here, as the anisotropic conductive paste, an anisotropic conductive paste containing a photocurable component curable by light irradiation, a thermosetting component curable by heating, and the conductive particles 5 is used. A method for manufacturing the connection structure 11 will be specifically described. Instead of the photocurable component and the thermosetting component, light and thermosetting components that can be cured by both light irradiation and heating may be used.

  First, the 1st connection object member 2 which has the several 1st electrode 2b which protruded on the surface 2a (1st main surface) is prepared. Next, as shown in FIG. 3A, a plurality of first electrodes are formed on the plurality of first electrodes 2b of the first connection target member 2 and on the gaps X between the plurality of first electrodes 2b. An insulating layer 6A is laminated so as to cover the electrode 2b.

  Next, as shown in FIG. 3B, the anisotropic conductive paste is applied on the surface 6a of the insulating layer 6A opposite to the first connection target member 2 side, and the anisotropic conductive paste is applied. Layer 3A is laminated. At this time, it is preferable that one or a plurality of conductive particles 5 be disposed on the insulating layer 6A located on the first electrode 2b.

  The thickness of the anisotropic conductive paste layer 3A is preferably at least 1.2 times the average particle diameter of the conductive particles 5, preferably at least 2 times, more preferably at least 3 times, It is preferably 20 times or less, and more preferably 10 times or less.

  Next, the anisotropic conductive paste layer 3A is cured by irradiating the anisotropic conductive paste layer 3A with light. 3A to 3C, the anisotropic conductive paste layer 3A is irradiated with light to advance the curing of the anisotropic conductive paste layer 3A, and the anisotropic conductive paste layer 3A is made into a B-stage. (B-stage process). That is, as shown in FIG. 3 (c), a B-staged anisotropic conductive layer 3B is formed on the surface 6a of the insulating layer 6A opposite to the first connection target member 2 side, thereby connecting the connection structure. 11 is gained. By the B-staging, the insulating layer 6A and the B-staged anisotropic conductive layer 3B are temporarily bonded. The B-staged anisotropic conductive layer 3B is a semi-cured product in a semi-cured state. The B-staged anisotropic conductive layer 3B is not completely cured, and thermal curing can further proceed. The anisotropic conductive paste layer 3A may be cured by heating instead of light irradiation. When the anisotropic conductive paste layer 3A contains a solvent, the B-staged anisotropic conductive layer 3B may be formed by removing the solvent of the anisotropic conductive paste layer 3A.

  It is preferable to irradiate the anisotropic conductive paste layer 3 </ b> A with light while applying the anisotropic conductive paste to the surface 2 a of the first connection target member 2. Furthermore, it is also preferable to irradiate the anisotropic conductive paste layer 3 </ b> A simultaneously with the application of the anisotropic conductive paste or immediately after the application. When the application and the light irradiation are performed as described above, the flow of the anisotropic conductive paste layer 3A 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 paste on the surface 2a of the first connection target member 2 to the irradiation of light is 0 second or longer, preferably 180 seconds or shorter, more preferably 60 seconds or shorter.

The light irradiation intensity for appropriately proceeding the curing of the anisotropic conductive paste layer 3A is, for example, preferably about 0.1 to 300 mW / cm ² . In addition, the irradiation energy of light for appropriately curing the anisotropic conductive paste layer 3A is, for example, preferably about 100 to 10,000 mJ / 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, a metal halide lamp, and an LED lamp.

  Next, using the connection structure 11 shown in FIGS. 1 and 3C, the connection structure 1 is manufactured as follows. The connection structure 11 is preferably used for producing the connection structure 1.

  As shown in FIG. 4A, the second connection target member 4 is laminated on the surface 3a opposite to the insulating layer 6A side of the B-staged anisotropic conductive layer 3B. The second connection target so that the plurality of first electrodes 2b on the surface 2a of the first connection target member 2 and the plurality of second electrodes 4b on the surface 4a of the second connection target member 4 face each other. The member 4 is laminated. In this state, the insulating layer 6A portion between the first electrode 2b and the B-staged anisotropic conductive layer 3B is not excluded. The conductive particles 5 and the first electrode 2b are not in contact with each other.

  Further, as shown in FIG. 4B, the B-staged anisotropic conductive layer 3B is heated by heating the B-staged anisotropic conductive layer 3B when the second connection target member 4 is laminated. It hardens | cures and forms the hardened | cured material layer 3 (main hardening process). In the main curing step, the conductive particles 5 are brought into contact with the first and second electrodes 2b and 4b, excluding the insulating layer 6A portion between the first electrode 2b and the B-staged anisotropic conductive layer 3B. Let As a result of eliminating the insulating layer 6A portion between the first electrode 2b and the B-staged anisotropic conductive layer 3B, the insulating layer 6 is formed. However, the B-staged anisotropic conductive layer 3B may be heated before the second connection target member 4 is laminated. Further, the B-staged anisotropic conductive layer 3 </ b> B may be heated after the second connection target member 4 is laminated. The B-staged anisotropic conductive layer 3B may be fully cured by irradiation with light instead of heating. Further, in the stacking process of the second connection object member 4, the insulating layer 6A portion between the first electrode 2b and the B-staged anisotropic conductive layer 3B is excluded, and the first and second electrodes 2b , 4b may be brought into contact with the conductive particles 5. However, in the main curing step, it is preferable to exclude the insulating layer 6A portion between the first electrode 2b and the B-staged anisotropic conductive layer 3B.

  The heating temperature for curing the B-staged anisotropic conductive layer 3B by heating is preferably 140 ° C. or higher, more preferably 160 ° C. or higher, preferably 250 ° C. or lower, more preferably 200 ° C. or lower.

  It is preferable to apply pressure when the B-staged anisotropic conductive layer 3B is fully cured. By compressing the conductive particles 5 with the first electrode 2b and the second electrode 4b by pressurization, the contact area between the first and second electrodes 2b, 4b and the conductive particles 5 can be increased. it can. Moreover, it is preferable to form the insulating layer 6 by excluding the insulating layer 6A portion between the first electrode 2b and the B-staged anisotropic conductive layer 3B by pressurization. It is preferable that the fluidity of the insulating layer 6A is increased by heating during the main curing. The insulating layer 6A is preferably cured during the main curing of the B-staged anisotropic conductive layer 3B.

  In this way, the first connection target member 2 and the second connection target member 4 are connected via the cured product layer 3 or the insulating layer 6. Further, the first electrode 2 b and the second electrode 4 b are electrically connected through the conductive particles 5. As a result, the connection structure 1 shown in FIG. 2 can be obtained. In this embodiment, since photocuring and thermosetting are used together, the anisotropic conductive paste can be cured in a short time.

  Anisotropic conductive paste layer or B-staged anisotropic by heating and main-curing after forming the anisotropic conductive paste layer to B-stage by applying heat or irradiating light at the time of producing the connection structure The conductive particles contained in the conductive layer become difficult to flow excessively 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. It can be further suppressed. For this reason, the insulation reliability and conduction | electrical_connection reliability between electrodes in a connection structure can be improved further.

  In addition, when the connection structure is manufactured, the anisotropic conductive paste layer is B-staged by irradiation with light, and then heated to be fully cured, thereby easily curing the B-staged anisotropic conductive layer. And it can be controlled accurately. For this reason, it can further suppress that the electroconductive particle contained in the B-staged anisotropic conductive layer flows excessively in the main curing stage. Accordingly, the conductive particles are easily arranged in a predetermined region. For this reason, the insulation reliability and conduction | electrical_connection reliability between electrodes in a connection structure can be improved further.

  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)), It can be used for 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)), or the like.

  The manufacturing method of the connection structure according to the present invention is suitable for COG applications. In the manufacturing method of the connection structure according to the present invention, it is preferable to use a semiconductor wafer or semiconductor chip (divided semiconductor wafer) and a glass substrate as the first connection target member and the second connection target member.

  In COG applications, in particular, it is often difficult to reliably connect the electrodes of the semiconductor chip and the glass substrate with the conductive particles of the anisotropic conductive paste. 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 8 to 20 μm, and fine wiring is often formed. Even if fine wiring is formed, the method for manufacturing a connection structure according to the present invention enables the conductive particles to be accurately placed between the electrodes, so that there is high accuracy between the electrodes of the semiconductor chip and the glass substrate. It is possible to improve the conduction reliability.

  For COG applications, both the semiconductor chip and the glass substrate are particularly hard. For this reason, the insulation reliability in the connection structure tends to be low. On the other hand, in the present invention, even when a hard semiconductor chip and a glass substrate are connected, the insulation reliability can be sufficiently increased.

  In the COG application, the surface of the first electrode protruding from the first connection target member is flattened before the insulating layer is laminated, so that the first connection target member and the second connection target member Connection reliability can be improved. In particular, when the first electrode from which the first connection object member protrudes is a copper electrode, the electrode has a high Young's modulus, so that the deformation of the electrode protruding at the time of connection is small. For this reason, since the deformation amount of the conductive particles may vary between the plurality of electrodes of the connection structure, it is preferable to planarize the surface of the first electrode in advance.

  Moreover, the manufacturing method of the connection structure which concerns on this invention is used suitably also for the connection of a semiconductor wafer and another connection object member. Furthermore, in order to obtain a connection structure in which the semiconductor chip and other connection target members are connected, it is preferable to obtain a stacked body (also a connection structure) in which the semiconductor wafer and other connection target members are connected. Used for. In this case, a semiconductor wafer is used as the first connection target member or the second connection target member. In particular, it is preferable to use a semiconductor wafer as the first connection target member. In the connection structure, the first connection target member is preferably a semiconductor wafer or an individual semiconductor chip that is a semiconductor wafer after division. When a semiconductor wafer is used as the first connection target member or the second connection target member, the method for manufacturing a connection structure according to the present invention cuts the semiconductor wafer, and after dividing the semiconductor wafer The step of forming individual semiconductor chips may be further provided. In the method for manufacturing a connection structure according to the present invention, after the cured product layer is formed, a laminate of the first connection target member, the insulating layer, the cured product layer, and the second connection target member is formed. A step of cutting and dividing the semiconductor wafer into individual semiconductor chips may be further provided.

  Furthermore, in the method for manufacturing a connection structure according to the present invention, a semiconductor wafer is used as the first connection target member, the insulating layer is formed, the first connection target member is cut, and individual semiconductors are cut. You may further provide the process divided | segmented into a chip | tip.

  When the first connection target member or the second connection target member is a semiconductor wafer, the concentration unevenness of the conductive particles occurs when the first connection target member and the second connection target member are stacked. However, there is a problem that it is difficult to ensure insulation between adjacent electrodes. On the other hand, by the method for manufacturing a connection structure according to the present invention, good insulation between adjacent electrodes is obtained even if the first connection target member or the second connection target member is a semiconductor wafer. Can be.

  When the first connection target member is a semiconductor wafer and the semiconductor wafer is separated into pieces by dicing or the like, the insulating layer is preferably transparent. The haze value of the insulating layer is preferably 60% or less, more preferably 20% or less, based on the thickness of the insulating layer formed on the semiconductor wafer. The haze value was obtained by preparing a film of an insulating layer having a target thickness and obtaining Th = Td / Tt (Td is a scattered light transmittance, Tt) obtained in accordance with JIS K7136 for transmittance measurement using the film. (Total light transmittance).

  Examples of the material for forming the insulating layer include a curable component and a thermoplastic component. The material preferably contains a thermosetting component. The thermosetting component preferably contains a thermosetting compound and a thermosetting agent. When the material forming the insulating layer includes a thermosetting component, the insulating layer is formed by heating and curing the thermosetting component. The insulating layer becomes a cured product layer. By using such a thermosetting component, the connection reliability between electrodes can be further improved.

  The material forming the insulating layer may contain a solvent. The insulating layer may be formed by applying a material for forming the insulating layer on the surface of the first connection target member and removing the solvent by drying.

  Examples of the solvent include an aliphatic solvent, a ketone solvent, an aromatic solvent, an ester solvent, an ether solvent, an alcohol solvent, a paraffin solvent, and a petroleum solvent.

  Examples of the aliphatic solvent include cyclohexane, methylcyclohexane, and ethylcyclohexane. Examples of the ketone solvent include acetone and methyl ethyl ketone. Examples of the aromatic solvent include toluene and xylene. Examples of the ester solvent include ethyl acetate, butyl acetate and isopropyl acetate. Examples of the ether solvent include tetrahydrofuran (THF) and dioxane. Examples of the alcohol solvent include ethanol and butanol. Examples of the paraffinic solvent include paraffin oil and naphthenic oil. Examples of the petroleum solvent include mineral terpenes and naphtha. As for the said solvent, only 1 type may be used and 2 or more types may be used together.

  The temperature at which the solvent is removed by drying is appropriately set according to the type of solvent used. The temperature at which the solvent is removed by drying is, for example, about 60 to 130 ° C. The lower the temperature at which the solvent is removed by drying, the lower the thermal degradation of the first connection target member.

  The minimum melt viscosity η2 in the measurement temperature range of 60 to 150 ° C. of the insulating layer and the anisotropic conductive paste is preferably 1 Pa · s or more, more preferably 10 Pa · s or more, and preferably 50000 Pa · s or less. The measurement temperature range of the minimum melt viscosity η2 is more preferably 60 to 120 ° C, still more preferably 70 to 100 ° C. When the minimum melt viscosity η2 is less than 1 Pa · s, voids tend to be generated due to the outflow of the resin. When the minimum melt viscosity η2 is not more than the above upper limit, the insulation reliability and the conduction reliability can be further improved.

  The minimum melt viscosity is determined by measuring the minimum complex viscosity η * using a rheometer. The measurement conditions are strain control 1 rad, frequency 1 Hz, temperature rising rate 20 ° C./min, and measurement temperature range 60 to 150 ° C.

  Examples of the rheometer include STRESTTECH (manufactured by EOLOGICA).

  It is preferable that the minimum melt viscosity of the anisotropic conductive paste is higher than the minimum melt viscosity of the insulating layer. The minimum melt viscosity of the insulating layer is preferably 1 Pa · s or more, more preferably 100 Pa · s or more, preferably 10000 Pa · s or less, more preferably 7000 Pa · s or less, and further preferably 4500 Pa · s or less. The minimum melt viscosity of the anisotropic conductive paste is preferably 100 Pa · s or more, more preferably 1000 Pa · s or more, preferably 50000 Pa · s or less, more preferably 30000 Pa · s or less, and further preferably 8000 Pa · s or less. is there. The absolute value of the difference between the minimum melt viscosity of the insulating layer and the minimum melt viscosity of the anisotropic conductive paste is preferably 1000 Pa · s or more, more preferably 3000 Pa · s or more. When the minimum melt viscosity of the insulating layer and the minimum melt viscosity of the anisotropic conductive paste show the preferable values, the void discharge property and the capture rate of the conductive particles are improved. If the minimum melt viscosity of the insulating layer is higher than the minimum melt viscosity of the anisotropic conductive paste, the minimum melt temperature of the anisotropic conductive paste is not less than the lower limit and not more than the upper limit. The discharge property and the capture rate of conductive particles are improved.

  The minimum melting temperature of the insulating layer is preferably lower than the minimum melting temperature of the anisotropic conductive paste. The minimum melting temperature of the insulating layer is preferably 60 ° C. or higher, more preferably 70 ° C. or higher, preferably 110 ° C. or lower, more preferably 100 ° C. or lower. The minimum melting temperature of the anisotropic conductive paste is preferably 60 ° C. or higher, more preferably 70 ° C. or higher, preferably 150 ° C. or lower, more preferably 120 ° C. or lower. The absolute value of the difference between the minimum melting temperature of the insulating layer and the minimum melting temperature of the anisotropic conductive paste is preferably 5 ° C. or higher, more preferably 10 ° C. or higher. When the minimum melting temperature of the insulating layer and the minimum melting temperature of the anisotropic conductive paste are equal to or higher than the lower limit and equal to or lower than the upper limit, the void discharge property and the capturing rate of conductive particles are improved. The minimum melting temperature is a temperature indicating the minimum melt viscosity.

  Viscosity ratio (η2 / η3) of viscosity η2 (Pa · s) at 1 Hz at a temperature showing the minimum melt viscosity of the anisotropic conductive paste to viscosity η3 (Pa · s) at 10 Hz at a temperature showing the minimum melt viscosity ) Is preferably 2 or more, more preferably 3 or more, and still more preferably 4 or more. If the viscosity ratio (η2 / η3) is greater than or equal to the lower limit, voids are less likely to occur in the cured product layer. When the viscosity ratio (η2 / η3) is 3 or more, voids are hardly generated in the cured product layer.

  Furthermore, when the viscosity ratio (η2 / η3) is equal to or higher than the lower limit, the anisotropic conductive paste can be prevented from unintentionally spreading before or during curing, and contamination in the connection structure is less likely to occur. be able to. Therefore, when the viscosity ratio (η2 / η3) is equal to or higher than the lower limit, suppression of voids in the cured product layer and suppression of contamination due to the flow of the anisotropic conductive paste layer or the B-staged anisotropic conductive layer Both effects can be obtained. The upper limit of the viscosity ratio (η2 / η3) is not particularly limited, but the viscosity ratio (η2 / η3) is preferably 8 or less.

  Regarding the exothermic peak temperature by DSC (differential scanning calorimetry) between the insulating layer and the anisotropic conductive paste, the exothermic peak temperature of the insulating layer is higher than the exothermic peak temperature of the anisotropic conductive paste. It is preferable. The absolute value of the difference between the exothermic peak temperature of the anisotropic conductive paste and the exothermic peak temperature of the insulating layer is preferably 5 ° C. or higher, more preferably 10 ° C. or higher. Thereby, the void discharge property and the capture rate of the conductive particles are improved.

  Regarding the heat generation by DSC (differential scanning calorimetry) between the insulating layer and the anisotropic conductive paste, the heat generation of the insulating layer is preferably smaller than the heat generation of the anisotropic conductive paste. Thereby, the void discharge property and the capture rate of the conductive particles are improved.

  The elastic modulus of the insulating layer (the insulating layer cured when the thermosetting material is used) and the cured layer obtained by curing the anisotropic conductive material is preferably 100 MPa or more, preferably 4 GPa or less at 25 ° C. At 85 ° C., preferably 10 MPa or more, preferably 3 GPa or less. When the elastic modulus is not less than the above lower limit and not more than the above upper limit, connection reliability when receiving a thermal history is increased.

  The glass transition temperature Tg of the insulating layer (the insulating layer cured when a thermosetting component is used) and the cured layer obtained by curing the anisotropic conductive paste are each preferably 60 ° C. or higher, preferably 180 ° C. or lower. It is. When the glass transition temperature is not less than the above lower limit and not more than the above upper limit, the connection reliability of the connection structure when receiving a thermal history is increased.

  The average thermal expansion coefficient of −30 ° C. to 85 ° C. of the insulating layer (the insulating layer cured when a thermosetting component is used) and the cured layer obtained by curing the anisotropic conductive paste is preferably 110 ppm / ° C. Hereinafter, it is more preferably 70 ppm / ° C. or less. When the average coefficient of thermal expansion is not less than the above lower limit and not more than the above upper limit, the connection reliability of the connection structure when receiving a thermal history is increased.

  The elastic modulus and the Tg are measured using a viscoelasticity measuring device DVA-200 (manufactured by IT Measurement & Control Co., Ltd.) under conditions of a heating rate of 5 ° C./min, a deformation rate of 0.1% and 10 Hz. The temperature at the peak of tan δ is defined as Tg (glass transition point).

  The anisotropic conductive paste is cured by irradiating the anisotropic conductive paste with light to form a B-stage and then further irradiating with light to fully cure the anisotropic conductive paste. After the B-stage, the method of further heating and main-curing, the method of irradiating the anisotropic conductive paste with light to form the B-stage, and further heating and main-curing, and heating the anisotropic conductive paste Then, after making the B stage, there is a method of further irradiating light to perform the main curing. In addition, when the photocuring speed and the thermosetting speed are different, light irradiation and heating may be performed simultaneously. In the B-stage forming step, the anisotropic conductive paste is cured by light irradiation to form a B-stage anisotropic conductive layer, and in the main curing step, the B-stage is formed by heating. It is preferable to fully cure the anisotropic conductive layer. The anisotropic conductive paste can be efficiently cured in a short time by the combined use of photocuring and heat curing.

  Furthermore, as a method of curing the anisotropic conductive paste, after removing the solvent of the anisotropic conductive paste to be B-staged, further irradiating with light to perform the main curing, and the anisotropic conductive paste There is also a method in which after the solvent is removed to form a B stage, the film is further heated to be fully cured.

  The anisotropic conductive paste is an anisotropic conductive paste curable by heating, and a curable compound (thermosetting compound or light and thermosetting compound) curable by heating is used as the curable compound. May be included. The curable compound curable by heating may be a curable compound (thermosetting compound) that is not cured by light irradiation, and is curable by both light irradiation and heating (light and light). Thermosetting compound).

  The anisotropic conductive paste is an anisotropic conductive paste that can be cured by light irradiation. As the curable compound, a curable compound that can be cured by light irradiation (a photocurable compound, or light and heat curing). A functional compound). The curable compound that can be cured by irradiation with light may be a curable compound that is not cured by heating (photocurable compound), or a curable compound that can be cured by both irradiation of light and heating (light and light). Thermosetting compound).

  The anisotropic conductive paste is preferably an anisotropic conductive paste that can be cured by both light irradiation and heating. The curable compound preferably contains a curable compound that can be cured by light irradiation and a curable compound that can be cured by heating. In this case, the anisotropic conductive paste is semi-cured (B-staged) by light irradiation, and after the fluidity of the anisotropic conductive paste is lowered, the anisotropic conductive paste is easily cured by heating. Can be made. The curable component contained in the anisotropic conductive paste preferably includes a photocurable component capable of being irradiated with light and a thermosetting component capable of being cured by heating. Moreover, it is preferable that the said curable component contained in the said anisotropic electrically conductive paste contains the light and thermosetting component which can be hardened | cured by both irradiation of light and a heating.

  Hereinafter, the detail of each component used suitably for the said insulating layer and the said anisotropic electrically conductive paste is demonstrated.

(Thermoplastic compounds)
Examples of the thermoplastic compound include (meth) acrylic resin, polyester resin, polyimide resin, polyamide resin, polyurethane resin, and polyepoxy resin.

(Curable compound)
The curable compound that can be used for the material for forming the insulating layer is not particularly limited. The curable compound contained in the anisotropic conductive paste is not particularly limited. A conventionally known curable compound can be used as the curable compound. 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 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 sclerosing | hardenable compound, only 1 type may be used and 2 or more types may be used together.

  The curable compound preferably contains a curable compound having an epoxy group or a thiirane group. The curable compound having an epoxy group is an epoxy compound. The curable compound having a thiirane group is an episulfide compound. As for the said curable compound which has an epoxy group or thiirane group, only 1 type may be used and 2 or more types may be used together.

  More preferably, the curable compound contains a curable compound having a 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 curable 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.

  From the viewpoint of increasing the curability of the anisotropic conductive paste, the content of the curable compound having the epoxy group or thiirane group is preferably 10% by weight or more in the total 100% by weight of the curable compound. Preferably they are 20 weight% or more and 100 weight% or less. The total amount of the curable compound may be a curable compound having the epoxy group or thiirane group. When the curable compound having the epoxy group or thiirane group and another curable compound different from the curable compound having the epoxy group or thiirane group are used in combination, in the total 100% by weight of the curable compound, The content of the curable compound having an epoxy group or thiirane group is preferably 99% by weight or less, more preferably 95% by weight or less, still more preferably 90% by weight or less, and particularly preferably 80% by weight or less.

  The curable compound may further contain another curable compound different from the curable compound having an epoxy group or a thiirane group. Examples of the other curable compounds include curable compounds having an unsaturated double bond, phenol curable compounds, amino curable compounds, unsaturated polyester curable compounds, polyurethane curable compounds, silicone curable compounds, and polyimide curable compounds. Compounds and the like. As for said other curable 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 paste and further improving the conduction reliability in the connection structure, the curable compound contains a curable compound having an unsaturated double bond. It is preferable to do. From the viewpoint of easily controlling the curing of the anisotropic conductive paste or further enhancing the conduction reliability in the connection structure, the curable compound having an unsaturated double bond is a (meth) acryloyl group. It is preferable that it is a curable compound which has. By using the above-mentioned curable compound having a (meth) acryloyl group, the curing rate can be improved with the entire B-staged anisotropic conductive paste (including the portion directly irradiated with light and the portion not directly irradiated with light). It becomes easy to control within a suitable range, and the conduction reliability in the resulting connection structure is further increased.

  From the viewpoint of easily controlling the curing rate of the B-staged anisotropic conductive paste layer and further improving the conduction reliability of the resulting connection structure, the curable compound having the (meth) acryloyl group is: It is preferable to have one or two (meth) acryloyl groups.

  From the viewpoint of easily controlling the curing rate of the B-staged anisotropic conductive paste layer and further improving the conduction reliability of the resulting connection structure, the curable compound having the (meth) acryloyl group is: It is preferable to have one or two (meth) acryloyl groups.

  The curable 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 (meth) A curable compound having an acryloyl group may be mentioned.

  As the curable compound having the (meth) acryloyl group, an ester compound obtained by reacting a (meth) acrylic acid and a compound having a hydroxyl group, an epoxy obtained by reacting (meth) acrylic acid and an epoxy compound ( A (meth) acrylate, a urethane (meth) acrylate obtained by reacting a (meth) acrylic acid derivative having a hydroxyl group with an isocyanate, or the like 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 curable compound having an epoxy group or thiirane group and having a (meth) acryloyl group is a part of the epoxy group or part of thiirane group of the compound having two or more epoxy groups or two or more thiirane groups. It is preferable that it is a curable compound obtained by converting into a (meth) acryloyl group. This curable compound is a partially (meth) acrylated epoxy compound or a partially (meth) acrylated episulfide compound.

  The curable compound preferably contains 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 curable compound, a modified phenoxy resin obtained by converting a part of epoxy groups of a phenoxy resin having two or more epoxy groups or two or more thiirane groups or a part of thiirane groups into a (meth) acryloyl group may be used. Good. That is, a modified phenoxy resin having an epoxy group or thiirane group and a (meth) acryloyl group may be used.

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

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

(Thermosetting agent)
The anisotropic conductive paste preferably contains a thermosetting agent as the thermosetting component. The thermosetting agent is not particularly 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, acid anhydrides, thermal cation curing agents, and thermal radical generators. As for the said thermosetting agent, only 1 type may be used and 2 or more types may be used together.

  From the viewpoint of curing the anisotropic conductive paste more rapidly at a low temperature, the anisotropic conductive paste preferably contains an imidazole curing agent, a polythiol curing agent, an amine curing agent, or a thermal cation curing agent.

  Moreover, since the storage stability of anisotropic conductive paste can be improved, a latent hardener is preferable. 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.

  As the thermal cation curing agent, iodonium salts and sulfonium salts are preferably used. For example, commercially available products of the above-mentioned thermal cation curing agent include San-Aid SI-45L, SI-60L, SI-80L, SI-100L, SI-110L, SI-150L manufactured by Sanshin Chemical Co., Ltd., and ADEKA manufactured by ADEKA Optomer SP-150, SP-170 etc. are mentioned.

Preferred anionic portions of the thermal cationic curing agent include SbF ₆ , PF ₆ , BF ₄ , and B (C ₆ F ₅ ) ₄ .

  From the viewpoint of further improving the connection reliability between the electrodes and the connection reliability of the connection structure under high temperature and high humidity, the anisotropic conductive paste preferably contains a thermal radical generator. The thermal radical generator is not particularly limited. As the thermal radical generator, a conventionally known thermal radical generator can be used. As for the said thermal radical generator, only 1 type may be used and 2 or more types may be used together. Here, the “thermal radical generator” means a compound that generates radical species by heating.

  The thermal radical generator is not particularly limited, and examples thereof include azo compounds and peroxides. Examples of the peroxide include diacyl peroxide compounds, peroxyester compounds, hydroperoxide compounds, peroxydicarbonate compounds, peroxyketal compounds, dialkyl peroxide compounds, and ketone peroxide compounds.

  Examples of the azo compound include 2,2′-azobisisobutyronitrile, 2,2′-azobis (2-methylbutyronitrile), and 2,2′-azobis (2,4-dimethylvaleronitrile). 1,1′-azobis-1-cyclohexanecarbonitrile, dimethyl-2,2′-azobisisobutyrate, dimethyl-2,2′-azobis (2-methylpropionate), dimethyl-1,1 ′ -Azobis (1-cyclohexanecarboxylate), 4,4'-azobis (4-cyanovaleric acid), 2,2'-azobis (2-amidinopropane) dihydrochloride, 2-tert-butylazo-2-cyanopropane 2,2′-azobis (2-methylpropionamide) dihydrate, 2,2′-azobis (2,4,4-trimethylpentane), and the like.

  Examples of the diacyl peroxide compound include benzoyl peroxide, diisobutyryl peroxide, di (3,5,5-trimethylhexanoyl) peroxide, dilauroyl peroxide, and disuccinic acid peroxide. Examples of the peroxyester compound include cumylperoxyneodecanoate, 1,1,3,3-tetramethylbutylperoxyneodecanoate, tert-hexylperoxyneodecanoate, and tert-butylperoxyneo. Decanoate, tert-butylperoxyneoheptanoate, tert-hexylperoxypivalate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, 2,5-dimethyl-2 , 5-di (2-ethylhexanoylperoxy) hexane, tert-hexylperoxy-2-ethylhexanoate, tert-butylperoxypivalate, tert-butylperoxy-2-ethylhexanoate, tert -Butyl peroxyisobutyrate, tert-butyl per Kishiraureto, tert- butylperoxy isophthalate, tert- butylperoxy acetate, tert- butylperoxy octoate and tert- butyl peroxybenzoate, and the like. Examples of the hydroperoxide compound include cumene hydroperoxide and p-menthane hydroperoxide. Examples of the peroxydicarbonate compound include di-sec-butyl peroxydicarbonate, di (4-t-butylcyclohexyl) peroxydicarbonate, di-n-propyl peroxydicarbonate, diisopropyl peroxycarbonate, and di- (2-ethylhexyl) peroxycarbonate and the like. Other examples of the peroxide include methyl ethyl ketone peroxide, potassium persulfate, and 1,1-bis (tert-butylperoxy) -3,3,5-trimethylcyclohexane.

  The decomposition temperature for obtaining the 10-hour half-life of the thermal radical generator is preferably 30 ° C. or higher, more preferably 40 ° C. or higher, preferably 80 ° C. or lower, more preferably 70 ° C. or lower. When the decomposition temperature for obtaining the 10-hour half-life of the thermal radical generator is less than 30 ° C., the storage stability of the anisotropic conductive paste tends to be lowered. It tends to be difficult to sufficiently heat cure the conductive paste.

  The content of the thermosetting agent is not particularly limited. The content of the thermosetting agent is preferably 0.01 parts by weight or more, more preferably 0.05 parts by weight or more, and still more preferably 5 parts by weight with respect to 100 parts by weight of the curable compound curable by heating. Above, particularly preferably 10 parts by weight or more, preferably 40 parts by weight or less, more preferably 30 parts by weight or less, and still 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 paste is sufficiently thermoset.

  When the thermosetting agent contains a thermal radical generator, the content of the thermal radical generator is preferably 0.01 parts by weight or more with respect to 100 parts by weight of the curable compound curable by heating. Preferably it is 0.05 weight part or more, Preferably it is 10 weight part or less, More preferably, it is 5 weight part or less. When the content of the thermal radical generator is not less than the above lower limit and not more than the above upper limit, the anisotropic conductive paste is sufficiently thermoset.

(Photocuring initiator)
The anisotropic conductive paste preferably contains a photocuring initiator as the photocuring component. The photocuring initiator is not particularly limited. A conventionally known photocuring initiator can be used as the photocuring initiator. From the viewpoint of further improving the connection reliability between the electrodes and the connection reliability of the connection structure, the anisotropic conductive paste preferably contains a photoradical generator. 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 is not limited to acetophenone photocuring initiator (acetophenone photoradical generator), benzophenone photocuring initiator (benzophenone photoradical generator), thioxanthone, ketal photocuring initiator (ketal photoradical). Generator), halogenated ketones, acyl phosphinoxides, acyl phosphonates, and the like. Examples of the photocuring initiator include a photocationic initiator.

  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 anisotropic conductive paste preferably contains a photocationic initiator. By using a photocation initiator, curing of the anisotropic conductive paste after light irradiation can be rapidly advanced. Furthermore, the anisotropic conductive paste layer portion where light is blocked by the conductive particles and is not directly irradiated can be sufficiently cured by the cation reaction due to the action of the photocation initiator.

  Examples of the photocationic curing agent include iodonium-based photocationic curing agents, oxonium-based photocationic curing agents, and sulfonium-based photocationic curing agents. Examples of the iodonium-based photocationic curing agent include bis (4-tert-butylphenyl) iodonium hexafluorophosphate). Examples of the oxonium-based photocationic curing agent include trimethyloxonium tetrafluoroborate. Examples of the sulfonium-based photocationic curing agent include tri-p-tolylsulfonium hexafluorophosphate and triphenylsulfonium bromide. Among these, from the viewpoint of further improving the curability of the anisotropic conductive paste and further improving the conduction reliability between the electrodes, a sulfonium-based photocationic curing agent is preferable.

  The content of the photocuring initiator is not particularly limited. For 100 parts by weight of the curable compound curable by light irradiation, the content of the photocuring initiator (the content of the photocationic initiator when the photocuring initiator is a photocationic initiator) is , Preferably 0.1 parts by weight or more, more preferably 0.2 parts by weight or more, preferably 2 parts by weight or less, more preferably 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 paste can be appropriately photocured. The anisotropic conductive paste can be prevented from flowing by irradiating the anisotropic conductive paste with light to form a B stage.

(Conductive particles)
The conductive particles contained in the anisotropic conductive paste 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. The surface of the conductive layer of the conductive particles may be covered with insulating particles. In these cases, the insulating layer or insulating particles between the conductive layer and the electrode are excluded when the connection target member is connected. Examples of the conductive particles include conductive particles obtained by coating the surfaces of organic particles, inorganic particles, organic-inorganic hybrid particles, or metal particles with a metal layer, and 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, and a metal layer containing tin.

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

  The average particle diameter of the conductive particles is preferably 0.5 μm or more, more preferably 1 μm or more, preferably 100 μm or less, more preferably 20 μm or less, still more preferably 15 μm or less, and particularly preferably 10 μm or less. From the viewpoint of further improving the connection reliability of the connection structure when subjected to a thermal history, the average particle diameter of the conductive particles is particularly preferably 1 μm or more and 10 μm or less, and is 1 μm or more and 4 μm or less. Most preferred.

  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 compressive elastic modulus (10% K value) at 23 ° C. of the conductive particles is preferably 1 GPa or more, more preferably 2 GPa or more, preferably 7 GPa or less, more preferably 5 GPa or less.

  The compression recovery rate of the conductive particles is preferably 20% or more, more preferably 30% or more, preferably 60% or less, more preferably 50% or less.

  The compressive elastic modulus (10% K value) at 23 ° C. of the conductive particles is measured as follows.

  Using a micro-compression tester, the conductive particles are compressed under the conditions of a compression rate of 2.6 mN / sec and a maximum test load of 10 g with the end face of a diamond cylinder having a diameter of 50 μm. The load value (N) and compression displacement (mm) at this time are measured. From the measured value obtained, the compression elastic modulus can be obtained by the following formula. As the micro compression tester, for example, “Fischer Scope H-100” manufactured by Fischer is used.

10% K value (N / mm ² ) = (3/2 ^1/2 ) · F · S ⁻³ / ² · R ^−1/2
F: Load value when the conductive particles are 10% compressively deformed (N)
S: Compression displacement (mm) when the conductive particles are 10% compressively deformed
R: radius of conductive particles (mm)

  The compression elastic modulus universally and quantitatively represents the hardness of the conductive particles. By using the compression elastic modulus, the hardness of the conductive particles can be expressed quantitatively and uniquely.

  The compression recovery rate can be measured as follows.

  Spread conductive particles on the sample stage. With respect to one dispersed conductive particle, a load is applied to the inversion load value (5.00 mN) in the central direction of the conductive particle using a micro compression tester. Thereafter, the load is gradually reduced to the load value for origin (0.40 mN). The load-compression displacement during this period is measured, and the compression recovery rate can be obtained from the following equation. The load speed is 0.33 mN / sec. As the micro compression tester, for example, “Fischer Scope H-100” manufactured by Fischer is used.

Compression recovery rate (%) = [(L1-L2) / L1] × 100
L1: Compressive displacement from the load value for the origin to the reverse load value when applying the load L2: Compressive displacement from the reverse load value to the load value for the origin when releasing the load

  The content of the conductive particles is not particularly limited. The content of the conductive particles in 100% by weight of the anisotropic conductive paste is preferably 0.1% by weight or more, more preferably 0.5% by weight or more, still more preferably 1% by weight or more, preferably 40% by weight. % Or less, more preferably 30% by weight or less, still more preferably 19% 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 paste preferably contains a filler. By using the filler, the thermal expansion coefficient of the cured anisotropic conductive paste can be suppressed. Specific examples of the filler include silica, aluminum nitride, alumina, glass, boron nitride, silicon nitride, silicone, carbon, graphite, graphene, and talc. As for a filler, only 1 type may be used and 2 or more types may be used together. When a filler having a high thermal conductivity is used, the main curing time is shortened.

  The anisotropic conductive paste 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 paste may contain a solvent. By using the solvent, the viscosity of the anisotropic conductive paste 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.

  From the viewpoint of further enhancing the connection reliability of the connection structure when receiving a thermal history, the anisotropic conductive paste preferably contains a thixotropic agent. Examples of the thixotropic agent include elastomer particles and silica. Examples of the elastomer particles include rubber particles. Examples of the rubber particles include natural rubber particles, isoprene rubber particles, butadiene rubber particles, styrene butadiene rubber particles, chloroprene rubber particles, and acrylonitrile butadiene rubber particles. The silica is preferably nano silica. The average particle diameter of the nano silica is less than 1000 nm.

  In 100% by weight of the insulating layer and 100% by weight of the anisotropic conductive paste, the content of the thixotropic agent is preferably 0.1% by weight or more, more preferably 1% by weight or more, preferably 30% by weight or less. More preferably, it is 15% by weight or less. When the content of the thixotropic agent is not less than the above lower limit and not more than the above upper limit, the connection reliability of the connection structure when receiving a thermal history is further enhanced.

  From the viewpoint of further improving the connection reliability of the first and second connection target members, it is preferable that the insulating layer and the anisotropic conductive paste each contain an adhesion-imparting agent. Examples of the adhesion-imparting agent include a coupling agent and a flexible material.

  In 100% by weight of the insulating layer and 100% by weight of the anisotropic conductive paste, the content of the adhesion-imparting agent is preferably 1% by weight or more, more preferably 5% by weight or more, and preferably 50% by weight or less. Preferably it is 25 weight% or less. When the content of the adhesion imparting agent is not less than the above lower limit and not more than the above upper limit, the connection reliability of the first and second connection target members is further increased.

  The insulating layer and the anisotropic conductive paste may contain an ion trapper or the like for the purpose of reducing impurity ions. When the protruding electrode of the first connection target member is Cu, the amount of extracted ion impurities in the cured insulating layer and the anisotropic conductive paste is preferably 10 ppm or less, more preferably 1 ppm or less. About 1 g of extracted ion impurities are precisely weighed into a D test tube (18 × 180 m / m), 10 ml of purified water is injected with a whole pipette, and the ampoule is sealed. Ions are extracted while shaking at 100 ° C for 20 hours. Thereafter, the extracted ion impurities are measured using IONEX DX-320J and DIONEX ICS-1000.

  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.

  In order to form an insulating layer on the surface of the first connection target member, the following resin materials were prepared.

(Preparation of material A for forming an insulating layer)
50 parts by weight of a glycidyl group-containing styrene resin (trade name “G-0250SP”, manufactured by NOF Corporation), 25 parts by weight of dicyclopentadiene type solid epoxy resin (trade name “HP-7200HH”, manufactured by DIC Corporation), 25 parts by weight of an aromatic epoxy resin (trade name “YX-8800”, manufactured by Mitsubishi Chemical Corporation) was stirred at 60 ° C. in a solvent, methyl ethyl ketone (MEK), and completely dissolved to obtain a solution.

  After cooling the obtained solution to room temperature, 33 parts by weight of acid anhydride (trade name “YH-309”, manufactured by Mitsubishi Chemical Corporation) and a silane coupling agent (trade name “KBE-402”) were added to the solution. “Shin-Etsu Chemical Co., Ltd.” 0.8 parts by weight, curing accelerator (trade name “Fujicure 7000”, manufactured by Fuji Kasei Kogyo Co., Ltd.) 3.3 parts by weight, nano silica (trade name “MT-10”, Tokuyama Co., Ltd.) 8.3 parts by weight) and methyl ethyl ketone (MEK) as a solvent were blended and stirred for 10 minutes at 2000 rpm using a planetary stirrer to obtain a blend having a solid content of 20% by weight. The obtained compound was filtered using nylon filter paper (pore diameter: 10 μm) to obtain a material A for forming an insulating layer.

  Material A was applied onto release PET, and the solvent was removed by drying at 80 ° C. for 10 minutes to obtain a film having a thickness of 15 μm. When the haze value of the obtained film was measured, it was 9.8%.

  Moreover, in the Example and the comparative example, in order to form the hardened | cured material layer which connects the 1st, 2nd connection object member, the following components were used.

[Thermosetting compound]
Episulfide compound 1B having a structure represented by the following formula (1B)

  Episulfide compound 2B represented by the following formula (2B)

  EP-3300P (manufactured by ADEKA, flexible epoxy resin)

[Photocurable compound]
EBECRYL 3702 (manufactured by Daicel-Cytec, fatty acid-modified epoxy acrylate)
EBECRYL 3708 (manufactured by Daicel-Cytec, caprolactone-modified epoxy acrylate)
4HBAGE (Nippon Kasei Co., Ltd., 4-hydroxybutyl acrylate glycidyl ether)

[Thermosetting agent]
TEP-2E4MZ (Nippon Soda Co., Ltd., Inclusion Imidazole)

[Photocuring initiator]
Irgacure 819 (BASF)

[Adhesive agent]
KBE-402 (manufactured by Shin-Etsu Chemical Co., Ltd., silane coupling agent)

[Filler]
Surface methyl-treated silica (average particle size 0.7 mm) (manufactured by Tokuyama)

[Thixotropic agent]
Nanosilica PM20L (manufactured by Tokuyama)

[Flexible particles]
KW-8800 (manufactured by Mitsubishi Rayon Co., Ltd., core-shell particles)

[Conductive particles]
The conductive particles A to D are all conductive particles having a metal layer in which a nickel plating layer is formed on the surface of the divinylbenzene resin particles and a gold plating layer is formed on the surface of the nickel plating layer. is there. The average particle diameter and 10% K of the conductive particles A to D are as follows.

Conductive particles A (average particle size 3 μm, 10% K value: 4.5 N / mm ² )
Conductive particles B (average particle size 3 μm, 10% K value: 5.2 N / mm ² )
Conductive particles C (average particle size 5 μm, 10% K value: 3.2 N / mm ² )
Conductive particles D (average particle size 7 μm, 10% K value: 2.8 N / mm ² )

Example 1
(1) Preparation of anisotropic conductive paste The components shown in Table 1 below were blended in the blending amounts shown in Table 1 below, and the resulting mixture was stirred for 5 minutes at 2000 rpm using a planetary stirrer to obtain a blend. It was. The obtained blend was filtered using a nylon filter paper (pore diameter 10 μm) to obtain an anisotropic conductive paste having a conductive particle content of 8% by weight.

(2) Production of Connection Structure A A semiconductor wafer (thickness 400 μm) having copper bumps (protruding electrodes, height 12 μm) with a bump size of 20 μm × 100 μm and a pitch of 30 μm on the upper surface was prepared. The material A was applied to the entire upper surface of the semiconductor wafer by spin coating. Thereafter, the solvent was dried in an oven at 80 ° C. for 20 minutes, and an insulating layer was formed on the plurality of electrodes and on the gaps between the plurality of electrodes so as to cover the plurality of electrodes. The thickness of the insulating layer on the protruding electrode was 4 μm, and the thickness of the insulating layer on the gap between the protruding electrodes was 15 μm.

  On the insulating layer, the obtained anisotropic conductive paste was applied by screen printing so as to have a thickness of 20 μm to form an anisotropic conductive paste layer.

Next, using an ultraviolet irradiation lamp, the anisotropic conductive paste layer is irradiated with ultraviolet rays from above for 3 seconds so that the irradiation energy is 100 mJ / cm ^2, and the anisotropic conductive paste layer is cured by photopolymerization. Advancing and B-staged (semi-cured) to form a B-staged anisotropic conductive layer.

  Thereafter, the semiconductor wafer with the insulating layer and the B-staged anisotropic conductive layer was diced using a dicer (DFD6361 manufactured by DISCO) and separated into pieces of 15 mm × 1.6 mm × 0.415 mm. In this manner, a semiconductor chip having a plurality of protruding electrodes on the upper surface (divided semiconductor wafer), an insulating layer on the plurality of electrodes and on a gap between the plurality of electrodes, and a B stage on the insulating layer A connection structure A having an anisotropic anisotropic conductive layer was obtained.

(3) Production of connection structure B A glass substrate having an ITO electrode with an L / S of 20 μm / 10 μm on the upper surface was prepared.

  Next, the glass substrate was laminated on the surface opposite to the insulating layer side of the B-staged anisotropic conductive layer of the obtained connection structure so that the electrodes / bumps were opposed to each other. Thereafter, a pressure heating head is placed on the surface opposite to the insulating layer side of the semiconductor chip while adjusting the head temperature so that the temperature of the B-staged anisotropic conductive layer becomes 190 ° C. The B-staged anisotropic conductive layer was cured at 190 ° C. for 20 seconds to obtain a connection structure B. In the obtained connection structure B, an insulating layer was also disposed in a partial region on the first electrode.

(Example 2)
An anisotropic conductive paste was obtained in the same manner as in Example 1 except that the conductive particles A were changed to the conductive particles B when the anisotropic conductive paste was prepared. Connection structures A and B were obtained in the same manner as in Example 1 except that the obtained anisotropic conductive paste was used.

(Example 3)
An anisotropic conductive paste was obtained in the same manner as in Example 1 except that the conductive particles A were changed to the conductive particles C when the anisotropic conductive paste was prepared. Connection structures A and B were obtained in the same manner as in Example 1 except that the obtained anisotropic conductive paste was used.

Example 4
An anisotropic conductive paste was obtained in the same manner as in Example 1 except that the conductive particles A were changed to the conductive particles D when the anisotropic conductive paste was prepared. Connection structures A and B were obtained in the same manner as in Example 1 except that the obtained anisotropic conductive paste was used.

(Example 5)
Material A was coated on a release PET (polyethylene terephthalate) film, and then the solvent was dried in an oven at 80 ° C. for 20 minutes to form a film. This film is vacuum laminated on a semiconductor wafer at 80 ° C., and a semiconductor wafer in which an insulating layer is formed on the plurality of protruding electrodes and the gap between the plurality of electrodes so as to cover the plurality of protruding electrodes. Got. The thickness of the insulating layer on the protruding electrode was 3 μm, and the thickness of the insulating layer on the gap between the protruding electrodes was 15 μm.

  Connection structures A and B were obtained in the same manner as in Example 1 except that the obtained semiconductor wafer was used.

(Example 6)
Connection structures A and B were obtained in the same manner as in Example 1 except that the material of the bumps in the semiconductor wafer was changed from copper to gold.

(Example 7)
(1) Preparation of anisotropic conductive paste The components shown in Table 1 below were blended in the blending amounts shown in Table 1 below, and the resulting mixture was stirred for 5 minutes at 2000 rpm using a planetary stirrer to obtain a blend. It was. The obtained blend was filtered using a nylon filter paper (pore diameter 10 μm) to obtain an anisotropic conductive paste having a conductive particle content of 8% by weight.

(2) Preparation of connection structure A Material A was coated on a release PET (polyethylene terephthalate) film, and then the solvent was dried in an oven at 80 ° C. for 20 minutes to form a film. This film is vacuum laminated at 80 ° C. on the semiconductor wafer used in Example 1, and insulated so as to cover the plurality of protruding electrodes on the protruding electrodes and on the gaps between the plurality of electrodes. A semiconductor wafer having a layer formed thereon was obtained. The thickness of the insulating layer on the protruding electrode was 3 μm, and the thickness of the insulating layer on the gap between the protruding electrodes was 15 μm.

  On the said insulating layer, the obtained anisotropic conductive paste was applied by screen printing so that the thickness after drying might be set to 20 micrometers, and the anisotropic conductive paste layer was formed. The solvent of the anisotropic conductive paste layer was removed by drying the solvent at 80 ° C. for 10 minutes to form a B-staged anisotropic conductive layer.

  Thereafter, the semiconductor wafer with the insulating layer and the B-staged anisotropic conductive layer was diced using a dicer (DFD6361 manufactured by DISCO) and separated into pieces of 15 mm × 1.6 mm × 0.415 mm. In this manner, a semiconductor chip having a plurality of protruding electrodes on the upper surface (divided semiconductor wafer), an insulating layer on the plurality of electrodes and on a gap between the plurality of electrodes, and a B stage on the insulating layer A connection structure A having an anisotropic anisotropic conductive layer was obtained.

(3) Production of Connection Structure B Using the obtained connection structure A, a connection structure B was obtained in the same manner as in Example 1.

(Comparative Example 1)
Material A was coated on a release PET (polyethylene terephthalate) film, and then the solvent was dried in an oven at 80 ° C. for 20 minutes to form a film. This film was vacuum-laminated on a semiconductor wafer at 80 ° C. to obtain a semiconductor wafer in which an insulating layer was formed only on a gap between the plurality of electrodes without forming an insulating layer on the plurality of electrodes. The thickness of the insulating layer above the gaps between the plurality of electrodes was 12 μm.

  Except having used the obtained semiconductor wafer, it carried out similarly to Example 1, and obtained the semiconductor chip and produced the connection structures A and B.

(Evaluation)
(1) Viscosity at room temperature of anisotropic conductive paste 10 rpm using an E-type viscosity measuring device (manufactured by TOKI SANGYO CO. LTD, trade name: VISCOMETER TV-22, rotor used: φ15 mm, temperature: 25 ° C.) The viscosity η1 (10 rpm) of the anisotropic conductive paste at 25 ° C. was measured. Similarly, the viscosity η1 (1 rpm) under the condition of 1 rpm was measured to determine the viscosity ratio (η1 (1 rpm) / η1 (10 rpm)).

(2) B-staged anisotropic conductive paste and insulating layer, or B-staged anisotropic conductive paste and insulating layer, minimum melt viscosity η2 and viscosity ratio (η2 / η3)
Using a rheometer (“STRESSTECH” manufactured by EOLOGICA), measurement conditions: strain control 1 rad, frequency 1 Hz, temperature rising rate 20 ° C./min, measurement temperature range 60 to 150 ° C. The temperature indicating the minimum melt viscosity η2 and the minimum melt viscosity of the staged anisotropic conductive paste (B-staged conductive layer) was measured. Further, the viscosity was measured in the same manner as described above except that the frequency was set to 10 Hz, the minimum melt viscosity η3 at the temperature showing the minimum melt viscosity was measured, and the viscosity ratio (η2 / η3) was obtained.

  The melt viscosity η2 of the insulating layer before curing at the minimum melting temperature of the anisotropic conductive paste after B-stage conversion, the melt viscosity η3 of the insulating layer before curing at the minimum melting temperature of the anisotropic conductive paste after B-stage conversion, It calculated | required similarly to the staged anisotropic conductive paste.

(3) Elastic modulus and glass transition temperature Tg at 25 ° C. of the cured product layer and the cured insulating layer obtained by curing the anisotropic conductive paste.
Samples of 3 mm width x 15 mm length x 0.1 mm thickness were prepared for the cured product layer and the cured insulating layer of the cured conductive layer in the connection structure, and the elastic modulus at 25 ° C and the glass transition temperature Tg. Then, using a viscoelasticity measuring device DVA-200 (manufactured by IT Measurement Control Co., Ltd.), the measurement was performed under the conditions of a heating rate of 5 ° C./min, a deformation rate of 0.1% and 10 Hz. The temperature at the peak of tan δ was defined as Tg (glass transition temperature).

(4) Indentation of Insulation Layer and Maximum Depth of Indentation In the first connection object member, it was evaluated whether or not the upper surface of the insulation layer was recessed on the recesses between the plurality of protruding first electrodes. In the case of depression, the maximum depth of the depression was measured. The measurement was performed using a laser microscope (VK-8700, manufactured by Keyence Corporation).

(5) Presence / absence of voids in cured product layer in connection structure In the obtained connection structure, whether or not voids were generated in the cured product layer obtained by curing the anisotropic conductive paste layer was observed with an optical microscope. The presence or absence of voids was determined according to the following criteria. If there are no voids, the connection reliability increases, and the fewer the voids, the higher the connection reliability.

[Criteria for the presence or absence of voids]
○: No void △: There is a slight void, but there is no void larger than the electrode L / S, pitch ×: There is a void larger than the size between adjacent electrodes

(6) Capture rate of conductive particles between electrodes (conducting accuracy of conductive particles)
The number of conductive particles present between the upper and lower electrodes facing each other in the obtained connection structure was counted with an optical microscope. The capture rate of conductive particles was determined according to the following criteria.

[Criteria for trapping rate of conductive particles]
○: 10 or more particles between each electrode ×: 9 or less particles between each electrode

(7) Conductivity The obtained connection structure was evaluated by the four-terminal method, and the resistance values at 20 locations were evaluated by the four-terminal method. The conductivity was determined according to the following criteria.

[Conductivity criteria]
○: The resistance value is 3Ω or less in all locations. Δ: There is one or more locations where the resistance value is 3Ω or more. ×: There is one or more locations that are not conducting at all.

(8) Insulating property It was measured with a tester whether or not a leak occurred in 20 adjacent electrodes of the obtained connection structure. Insulation was judged according to the following criteria.

[Insulation criteria]
○: No leak point ×: Leak point

(9) Connection reliability when subjected to thermal history 100 obtained connection structures are held at −30 ° C. for 5 minutes, then heated to 120 ° C. in 25 minutes, and held at 120 ° C. for 5 minutes. After that, a cold cycle test was performed in which the process of lowering the temperature to -30 ° C in 25 minutes was one cycle. After 1000 cycles, the connection structure was removed.

  About 100 connection structures after the thermal cycle test, it was evaluated whether or not conduction failure between the upper and lower electrodes occurred. Of the 100 connection structures, the case where the number of defective conductions is 1 or less is “◯”, the case of 2 or more, 3 or less is “Δ”, the case of 4 or more It was determined as “x”.

(10) Moisture and heat resistance test The obtained connection structure (n = 15) was allowed to stand for 1000 hours under the conditions of 85 ° C. and 85% RH, and then the conductivity was evaluated in the same manner. The case where the result in the continuity determination criterion (7) was “◯” was determined as “◯”, and the case where the result in the continuity determination criterion was “×” was determined as “X”.

  The results are shown in Table 1 below.

DESCRIPTION OF SYMBOLS 1 ... Connection structure 2 ... 1st connection object member 2a ... Surface 2b ... 1st electrode 3 ... Hardened | cured material layer 3a ... Surface 3A ... Anisotropic conductive paste layer 3B ... B-staged anisotropic conductive layer 4 ... 2nd connection object member 4a ... surface 4b ... 2nd electrode 5 ... electroconductive particle 6 ... insulating layer 6A ... insulating layer 6a ... surface 11 ... connection structure X ... clearance gap between 1st electrodes

Claims (16)

Using the first connection object member having a plurality of protruding first electrodes on the surface, a plurality of the first electrodes on the plurality of first electrodes and on the gaps between the plurality of first electrodes. Laminating an insulating layer so as to cover the electrodes,
Applying an anisotropic conductive paste containing a curable component and conductive particles on the surface of the insulating layer opposite to the first connection target member side, and laminating the anisotropic conductive paste layer When,
A method of manufacturing a connection structure, comprising: a B-stage forming step of forming a B-staged anisotropic conductive layer by removing a solvent from the anisotropic conductive paste layer or by proceeding with curing.   A plurality of second connection target members having a plurality of second electrodes on the surface of the anisotropic conductive paste layer or the B-staged anisotropic conductive layer opposite to the insulating layer side, The manufacturing method of the connection structure according to claim 1, further comprising a step of stacking the first electrode and the plurality of second electrodes facing each other. The B-staged anisotropic conductive layer is fully cured to form a cured product layer, and further includes a main curing step of electrically connecting the first and second connection target members by the cured product layer,
Excluding the insulating layer portion between the first electrode and the conductive particles contained in the B-staged anisotropic conductive layer, the conductive particles are formed on the first and second electrodes. The manufacturing method of the connection structure of Claim 1 or 2 which makes these contact.   The manufacturing method of the connection structure of any one of Claims 1-3 which uses a semiconductor wafer as said 1st connection object member. Using a semiconductor wafer as the first connection target member,
The manufacturing method of the connection structure of any one of Claims 1-4 further equipped with the process of cut | disconnecting the said semiconductor wafer and making it into each semiconductor chip which is a semiconductor wafer after a division | segmentation.   The manufacturing method of the connection structure of any one of Claims 1-5 whose said 1st electrode is a copper electrode.   The curable component contained in the anisotropic conductive paste includes a photocurable component capable of being irradiated by light and a thermosetting component capable of being cured by heating, or by both irradiation of light and heating. The manufacturing method of the connection structure of any one of Claims 1-6 containing the light and thermosetting component which can be hardened | cured.   The connection according to any one of claims 1 to 7, wherein the curable component contained in the anisotropic conductive paste includes a light and a thermosetting component that can be cured by both light irradiation and heating. Manufacturing method of structure. In the B-stage forming step, the anisotropic conductive paste is cured by light irradiation to form a B-stage anisotropic conductive layer,
The method for manufacturing a connection structure according to any one of claims 1 to 8, wherein in the main curing step, the B-staged anisotropic conductive layer is main-cured by heating.   The manufacturing method of the connection structure of any one of Claims 1-9 in which the said anisotropic electrically conductive paste further contains a solvent. A first connection target member having a plurality of protruding first electrodes on the surface;
An insulating layer stacked on the plurality of first electrodes and on the gaps between the plurality of first electrodes;
A B-staged anisotropic conductive layer laminated on the surface opposite to the first connection target member side of the insulating layer;
The B-staged anisotropic conductive layer is formed by removing the solvent of the anisotropic conductive paste using an anisotropic conductive paste containing a curable component and conductive particles or by proceeding with curing. A connection structure. A first connection target member having a plurality of protruding first electrodes on the surface;
An insulating layer stacked on a partial region on the first electrode and a plurality of gaps between the first electrodes;
A cured product layer laminated on a surface opposite to the first connection target member side of the insulating layer;
A second connection target member that is laminated on a surface opposite to the insulating layer side of the cured product layer and has a plurality of second electrodes on the surface;
The cured product layer is formed by main-curing the anisotropic conductive paste using an anisotropic conductive paste containing a curable component and conductive particles,
A connection structure in which a plurality of the first electrodes and a plurality of the second electrodes are electrically connected by the conductive particles.   The connection structure according to claim 11 or 12, wherein the first connection target member is a semiconductor wafer or an individual semiconductor chip that is a divided semiconductor wafer.   The connection structure according to any one of claims 11 to 13, wherein the first electrode is a copper electrode.   The curable component contained in the anisotropic conductive paste includes a photocurable component capable of being irradiated by light and a thermosetting component capable of being cured by heating, or by both irradiation of light and heating. The connection structure according to claim 11, comprising a curable light and a thermosetting component.   The connection according to any one of claims 11 to 15, wherein the curable component contained in the anisotropic conductive paste includes a light and a thermosetting component that can be cured by both light irradiation and heating. Structure.

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