JP2013001712A - Connection material for electronic part, connection structure and method for producing connection structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a connection material for electronic parts, which can enhance connection reliability.SOLUTION: The connection material for electronic parts, whose hardening is advanced by the irradiation of light and then further hardened by heating, includes at least two kinds of curable compounds selected from the group consisting of a methacryloyl group-having curable compound, an acryloyl group-having curable compound, and a vinyl group-having curable compound, or at least two kinds of curable compounds having different Q values, and in addition, includes a photoradical initiator, and a thermal radical initiator.

Description

  The present invention is a connection material for electronic components used to connect various connection target members, for example, for connection of various connection target members such as a flexible printed circuit board, a glass substrate, a glass epoxy substrate, and a semiconductor chip. The present invention relates to a connection material for electronic parts that can be used, a connection structure using the anisotropic conductive material, and a method of manufacturing the connection structure.

  A curable composition is used to bond various connection target members to obtain various connection structures. The curable composition is widely used for connecting electronic components. Moreover, in order to electrically connect between electrodes in various connection target members, conductive particles may be blended in the curable composition. A curable composition containing conductive particles is called an anisotropic conductive material. In the anisotropic conductive material, a plurality of conductive particles are dispersed in a binder resin or the like.

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

  As an example of the anisotropic conductive material, Patent Document 1 below includes an epoxy resin, rubber-like polymer particles, a thermally active latent epoxy curing agent, high softening point polymer particles, and conductive particles. An anisotropic conductive material is disclosed.

JP 2000-345010 A

  For example, when the electrode of the semiconductor chip and the electrode of the glass substrate are electrically connected by the anisotropic conductive material, an anisotropic conductive material containing conductive particles is disposed on the glass substrate. Next, the semiconductor chips are stacked, and heated and pressurized. As a result, the anisotropic conductive material is cured, and the electrodes are electrically connected via the conductive particles to obtain a connection structure.

  In the conventional anisotropic conductive material as described in Patent Document 1, the anisotropic conductive material applied on the glass substrate and the anisotropic conductive material are included in the electrical connection between the electrodes. The conductive particles that are present may flow greatly before curing. For this reason, the hardened | cured material layer and electroconductive particle which the anisotropic conductive material hardened | cured may not be arrange | positioned in a specific area | region. For this reason, dispersion | variation arises in the width | variety and thickness of a hardened | cured material layer, and the connection reliability of connection object members, such as a semiconductor chip and a glass substrate, may become low. Furthermore, the conductive particles may not be disposed between the upper and lower electrodes to be connected, or adjacent electrodes that should not be connected may be electrically connected via a plurality of conductive particles. For this reason, the conduction | electrical_connection reliability between electrodes in the connection structure obtained may become low.

  An object of the present invention is to provide a connection material for electronic components that can reduce variations in the width and thickness of a cured product layer obtained by curing the connection material for electronic components when connecting the connection target members, and can improve connection reliability. It is another object of the present invention to provide a connection structure using the connection material for electronic parts and a method for manufacturing the connection structure.

  A limited object of the present invention is an anisotropic conductive material containing conductive particles, and when used for electrical connection between electrodes, the connection material for electronic components that can improve conduction reliability The present invention also provides a connection structure using the connection material for electronic parts and a method for manufacturing the connection structure.

  According to a wide aspect of the present invention, a curing material having a methacryloyl group, a curable compound having an acryloyl group, which is a connection material for an electronic component that is further cured by heating after being cured by light irradiation. And at least two curable compounds selected from the group consisting of curable compounds having a vinyl group, or at least two curable compounds having different Q values, and a photo radical initiator, There is provided a connection material for an electronic component, further comprising a thermal radical initiator.

  In one specific aspect of the present invention, a curing material having a methacryloyl group, a curable compound having an acryloyl group, which is a connection material for an electronic component that is cured by heating after being cured by light irradiation. And a connecting material for electronic parts, comprising at least two curable compounds selected from the group consisting of a curable compound having a vinyl group, a photo radical initiator, and a thermal radical initiator.

  Further, in a specific aspect of the present invention, at least two curable compounds having different Q values, which are curing materials by heating after curing by light irradiation, are further cured by heating, and light There is provided a connecting material for electronic parts, which contains a radical initiator and a thermal radical initiator.

  In another specific aspect of the electronic component connecting material according to the present invention, the at least two curable compounds having different Q values are each a curable compound having a methacryloyl group, a curable compound having an acryloyl group, or It is a curable compound having a vinyl group.

  In still another specific aspect of the electronic component connecting material according to the present invention, the at least two curable compounds having different Q values are a curable compound having a methacryloyl group, a curable compound having an acryloyl group, and It is at least two curable compounds selected from the group consisting of curable compounds having a vinyl group.

  Among the at least two curable compounds having different Q values, the Q value of the first curable compound having the highest Q value has the highest Q value among the at least two curable compounds having different Q values. It is preferable that it is 0.1 or more higher than the Q value of the low second curable compound.

  When the reaction rate of the entire curable compound contained in the connection material for electronic parts according to the present invention reaches 20%, the reaction consumption rate after light irradiation of the at least two curable compounds is the highest. The reaction consumption rate after light irradiation of the high first curable compound is the reaction after light irradiation of the second curable compound having the lowest reaction consumption rate after light irradiation of the at least two curable compounds. The consumption rate is preferably 3 times or more.

  In another specific aspect of the connection material for electronic parts according to the present invention, the curable compound includes a curable compound having a methacryloyl group and a curable compound having an acryloyl group, and the curable compound is Does not contain or contains a curable compound having a vinyl group.

  In another specific aspect of the connection material for electronic components according to the present invention, the connection material for electronic components further contains conductive particles and is an anisotropic conductive material.

  In another specific aspect of the connection material for electronic parts according to the present invention, the connection material for electronic parts further contains conductive particles, and is a paste-like anisotropic conductive paste.

  The connection structure according to the present invention includes a first connection target member, a second connection target member, and a cured product layer connecting the first and second connection target members, The hardened | cured material layer is formed by hardening the connection material for electronic components comprised according to this invention.

  In a specific aspect of the connection structure according to the present invention, the first connection target member has a first electrode on the upper surface, the second connection target member has a second electrode on the lower surface, The connection material for electronic parts is an anisotropic conductive material containing conductive particles, and the first electrode and the second electrode are electrically connected by the conductive particles.

  The method for manufacturing a connection structure according to the present invention includes a step of forming a connection material layer using a connection material for an electronic component configured according to the present invention on a first connection target member, The step of forming a connection material layer that has been B-staged by proceeding with curing by irradiating the substrate, the step of laminating a second connection target member on the connection material layer that has been B-staged, and the above And heating the B-staged connection material layer to perform main curing to form a cured product layer.

  In a specific aspect of the manufacturing method of the connection structure according to the present invention, the first connection target member having the first electrode on the upper surface is used as the first connection target member, and the second connection target member is used. Using a second connection target member having a second electrode on the lower surface, and using an anisotropic conductive material containing conductive particles as the connection material for the electronic component, the first electrode and the second electrode Are electrically connected by the conductive particles.

  In another specific aspect of the method for manufacturing a connection structure according to the present invention, in the B-staged connection material layer, the reaction consumption rate after light irradiation of the at least two curable compounds is the highest. The reaction consumption rate after light irradiation of the first curable compound is the reaction consumption after light irradiation of the second curable compound having the lowest reaction consumption rate after light irradiation of the at least two curable compounds. Make it more than 3 times the rate.

  The connection material for an electronic component according to the present invention includes at least two curable compounds selected from the group consisting of a curable compound having a methacryloyl group, a curable compound having an acryloyl group, and a curable compound having a vinyl group. Or at least two kinds of curable compounds having different Q values, and further contains a photo radical initiator and a thermal radical initiator. Can be cured. After proceeding with curing by light irradiation, the connecting material for electronic parts can be cured in a plurality of stages by further heating and curing. For this reason, the flow of the connection material for electronic components can be suppressed by irradiating the connection material for electronic components with light at an appropriate time and further heating. Therefore, the hardened | cured material layer which hardened the connection material for electronic components can be arrange | positioned in a specific area | region. For this reason, the connection reliability of the connection object member connected using the connection material for electronic components which concerns on this invention can be improved.

FIG. 1 is a front cross-sectional view schematically showing a connection structure using a connection material for electronic parts according to an embodiment of the present invention. FIGS. 2A to 2C are partial cutaway front cross-sectional views for explaining each step of obtaining a connection structure using the electronic component connection material according to one embodiment of the present invention. FIGS. 3A to 3C show the relationship between the reaction time and the reaction rate of the curable compound when the electronic component connecting material is irradiated with light and then cured to be heated and further cured. It is a figure for demonstrating.

  Hereinafter, the present invention will be described in detail.

  The connection material for electronic parts according to the present invention is a connection material for electronic parts that is cured by heating after being cured by light irradiation. The connection material for electronic parts is a connection material used for connecting electronic parts.

  The connection material for an electronic component according to the present invention includes at least two curable compounds selected from the group consisting of a curable compound having a methacryloyl group, a curable compound having an acryloyl group, and a curable compound having a vinyl group. Or at least two curable compounds having different Q values. The connection material for electronic components according to the present invention contains a photo radical initiator and a thermal radical initiator. The connection material for an electronic component according to the present invention includes at least two curable compounds selected from the group consisting of a curable compound having a methacryloyl group, a curable compound having an acryloyl group, and a curable compound having a vinyl group. May be contained, and at least two curable compounds having different Q values may be contained. The at least two curable compounds preferably include at least two curable compounds having different reaction consumption rates. At least two curable compounds having different Q values have different reaction consumption rates. A curable compound having a methacryloyl group and a curable compound having an acryloyl group generally have different Q values and reaction consumption rates. A curable compound having a methacryloyl group and a curable compound having a vinyl group generally have a Q value and The reaction consumption rate is different, and the curable compound having an acryloyl group and the curable compound having a vinyl group generally have different Q values and reaction consumption rates.

  By employing the above composition, the connection material for electronic components can be cured in a plurality of stages by light irradiation and heating. That is, after the connection material for electronic parts is cured by light irradiation, the connection material for electronic parts can be cured well by further curing by heating. By irradiating the electronic component connecting material with light at an appropriate time and further heating it, the flow of the electronic component connecting material can be suppressed and cured. Therefore, the hardened | cured material layer which the connection material for electronic components hardened | cured can be arrange | positioned in a specific area | region. For this reason, the dispersion | variation in the width | variety and thickness of hardened | cured material layer can be reduced. Therefore, the connection reliability of the connection object member connected using the connection material for electronic components according to the present invention can be improved.

  The connection material for electronic parts according to the present invention preferably further contains conductive particles and is preferably an anisotropic conductive material. Therefore, the connecting material for electronic parts according to the present invention includes at least two types of curing selected from the group consisting of a curable compound having a methacryloyl group, a curable compound having an acryloyl group, and a curable compound having a vinyl group. Or at least two curable compounds having different Q values, further containing a photo radical initiator, a thermal radical initiator, and conductive particles, and an anisotropic conductive material Preferably there is. In this case, the connection material for electronic parts is irradiated with light at an appropriate time and further heated to suppress not only the curable components in the connection material for electronic parts but also the flow of conductive particles. It can be cured. Therefore, the electroconductive particle contained in the hardened | cured material layer can also be arrange | positioned in a specific area | region. For this reason, while being able to improve the connection reliability of the connection object member connected using the connection material for electronic components which concerns on this invention, the conduction | electrical_connection reliability between the electrodes in a connection object member can also be improved.

  Hereinafter, first, details of each component contained in the connection material for electronic parts according to the present invention will be described.

(Curable compound)
The connecting material for electronic parts contains at least two curable compounds selected from the group consisting of a curable compound having a methacryloyl group, a curable compound having an acryloyl group, and a curable compound having a vinyl group. Or at least two curable compounds having different Q values. The connection material for electronic parts may further contain a curable compound other than a curable compound having a methacryloyl group, a curable compound having an acryloyl group, and a curable compound having a vinyl group.

  Examples of the curable compound contained in the electronic component connecting material include a photocurable compound and a thermosetting compound. The photocurable compound has photocurability. The thermosetting compound has thermosetting properties. The photocurable compound may have photocurability and thermosetting properties, and may be light and thermosetting compounds. The curable compound includes at least the light and thermosetting compounds, or includes a photocurable compound and a thermosetting compound.

  The said curable compound which can be used for the said connection material for electronic components is not specifically limited. Examples of the curable compound include oxetane compounds, epoxy compounds, episulfide compounds, (meth) acrylic compounds, vinyl compounds, phenolic compounds, amino compounds, unsaturated polyester compounds, polyurethane compounds, silicone compounds, and polyimide compounds. The (meth) acryl means acryl or methacryl.

  In the connection material for electronic parts according to the present invention, as all or part of the curable compound, the curable compound having a methacryloyl group, the curable compound having an acryloyl group, and the curable compound having a vinyl group are used. At least two selected curable compounds are used, or at least two curable compounds having different Q values are used.

  In the case of using at least two curable compounds selected from the group consisting of a curable compound having a methacryloyl group, a curable compound having an acryloyl group, and a curable compound having a vinyl group, the connection material for electronic parts described above May contain a curable compound having a methacryloyl group and a curable compound having an acryloyl group, or may contain a curable compound having a methacryloyl group and a curable compound having a vinyl group. Well, it may contain a curable compound having an acryloyl group and a curable compound having a vinyl group, a curable compound having a methacryloyl group, a curable compound having an acryloyl group, and a curable compound having a vinyl group And may be contained.

  Since it is easy to appropriately control the reaction consumption rate by light irradiation, at least two curable compounds having different Q values are respectively a curable compound having a methacryloyl group, a curable compound having an acryloyl group, Or it is preferable that it is a curable compound which has a vinyl group. As at least two types of curable compounds having different Q values, the connection material for electronic parts may contain two or more types of curable compounds having a methacryloyl group, and two or more types of curing having an acryloyl group. A curable compound having a methacryloyl group and a curable compound having a vinyl group may be contained, or two or more curable compounds having a vinyl group may be contained. And may contain a curable compound having an acryloyl group and a curable compound having a vinyl group, a curable compound having a methacryloyl group, a curable compound having an acryloyl group, and a curing having a vinyl group. It may contain a functional compound.

  Since it is much easier to appropriately control the reaction consumption rate by light irradiation, at least two kinds of curable compounds having different Q values are curable compounds having a methacryloyl group and curable compounds having an acryloyl group. And at least two curable compounds selected from the group consisting of curable compounds having a vinyl group.

  Examples of the curable compound having a methacryloyl group include a curable compound having a methacryloyl group among the curable compounds described below. From the viewpoint of improving photocurability and further improving connection reliability and conduction reliability, the curable compound having a methacryloyl group is preferably methyl methacrylate.

  Examples of the curable compound having an acryloyl group include a curable compound having an acryloyl group among the curable compounds described below. From the viewpoint of improving photocurability and further improving connection reliability and conduction reliability, the curable compound having an acryloyl group is preferably epoxy acrylate or urethane acrylate.

  Examples of the curable compound having a vinyl group include vinyl acetate monomer. From the viewpoint of improving photocurability and further improving connection reliability and conduction reliability, the curable compound having a vinyl group is preferably a vinyl acetate monomer.

  It is preferable that the curable compound includes a curable compound having a methacryloyl group and a curable compound having an acryloyl group, and the curable compound does not include or includes a curable compound having a vinyl group. The combined use of a curable compound having a methacryloyl group and a curable compound having an acryloyl group makes it easier to control the photocurability, making the photocurability even better, and the connection reliability of the connection target member And the conduction reliability between the electrodes can be further improved.

  Among the at least two curable compounds having different Q values, the Q value of the first curable compound having the highest Q value has the highest Q value among the at least two curable compounds having different Q values. It is preferable that it is 0.1 or more higher than the Q value of the low second curable compound. In this case, the connection reliability of the connection target member and the conduction reliability between the electrodes can be further enhanced. Moreover, when the connection material for electronic components is irradiated with light, the degree of progress of photocuring in the entire curable compound can be appropriately adjusted. For example, the first curable compound having the highest Q value can be selectively cured by light irradiation. The second curable compound having the lowest Q value is preferably a curable compound having thermosetting properties.

  The curable compound having a high Q value has high reactivity as the curable compound, while having low activity as a radical. The curable compound having a low Q value has low reactivity as the curable compound, while having high activity as a radical. If the reactivity of the curable compound is low, it is difficult to react until another curable compound is consumed. Further, once the curable compound becomes a radical, the reaction of the remaining curable compound is promoted.

  When connecting various connection target members using connection materials for electronic components, the reaction during light irradiation is required to proceed relatively gently in order to control and manage photocuring. In order to increase the temperature, the reaction during heating is required to proceed relatively quickly.

  FIGS. 3A to 3C show the relationship between the reaction time and the reaction rate of the curable compound when the connection material for electronic parts is irradiated with light and allowed to cure and then further heated and cured. Indicates.

  When at least two kinds of curable compounds having different Q values are not used, as shown in FIG. 3 (a), when the curing of the connecting material for electronic parts is performed by light irradiation, the reaction is relatively The reaction proceeds promptly (from point A to point B). On the other hand, the reaction proceeds relatively moderately (from point B to point C) when further cured by heating after curing by light irradiation. .

  By using at least two kinds of curable compounds having different Q values, as compared with the case where at least two kinds of curable compounds having different Q values are not used, as shown in FIG. When the curing is advanced by irradiation with light, the reaction can be allowed to proceed gently (from point A to point B). On the other hand, after the curing proceeds by irradiation with light, it is further cured by heating. The reaction can proceed quickly (from point B to point C).

  Further, among at least two curable compounds having different Q values, the Q value of the first curable compound having the highest Q value is the Q value of at least two curable compounds having different Q values. Is higher than the Q value of the lowest second curable compound by 0.1 or more, as shown in FIG. 3 (c), when curing the connection material for electronic parts by light irradiation, The reaction can proceed fairly gently (from point A to point B). On the other hand, after curing proceeds by light irradiation, the reaction can proceed fairly quickly when further cured by heating. Yes (from point B to point C). Therefore, control and management of photocuring are facilitated, and connection reliability can be improved by promptly proceeding with heat curing.

  Utilizing the difference in reactivity of the curable compound, the reaction consumption is inferior after the photocuring of the connecting material is advanced by the curable compound having a low reaction rate and a high Q value that is preferred in terms of reaction consumption. The relationship between the reaction time and the reaction rate of the curable compound as shown in FIG. 3B is obtained by thermally curing the connection material that has been photocured with a curable compound having a high reaction rate and a low Q value. Further, by selecting an appropriate Q value, the relationship between the reaction time and the reaction rate of the curable compound as shown in FIG.

  The above-mentioned at least two kinds of curability when the reaction rate of the entire curable compound contained in the electronic component connecting material reaches 20% when the electronic component connecting material according to the present invention is irradiated with light. The reaction consumption rate R1 after light irradiation of the first curable compound having the highest reaction consumption rate after light irradiation of the compound is the reaction consumption rate after light irradiation of the at least two curable compounds. The reaction consumption rate R2 after light irradiation of the lowest second curable compound is preferably 3 times or more. In this case, the connection reliability of the connection target member and the conduction reliability between the electrodes can be further enhanced. Moreover, when the connection material for electronic components is irradiated with light, the degree of progress of photocuring in the entire curable compound can be appropriately adjusted. For example, a first curable compound having a high reaction consumption rate can be selectively cured by light irradiation. The second curable compound having the lowest reaction consumption rate after light irradiation is preferably a curable compound having thermosetting properties.

  Moreover, when the reaction rate of the whole curable compound contained in the connection material for electronic parts reaches 20%, the reaction consumption rate after light irradiation of the at least two curable compounds is the highest. The reaction consumption rate after light irradiation of one curable compound is the reaction consumption rate after light irradiation of the second curable compound having the lowest reaction consumption rate after light irradiation of the at least two curable compounds. 3 or more, as shown in FIG. 3 (c), when curing the connecting material for electronic components by light irradiation, the reaction can proceed fairly gently (point A). From point B), on the other hand, the reaction can proceed fairly quickly when curing is further carried out by heating after curing by light irradiation (from point B to point C).

  In the present specification, the reaction consumption rate R1 of the first curable compound refers to the amount of the first curable compound in the curable compound as A1 (% by weight), GC-MS (gas chromatograph weight). Analyzer) is used to quantitate the remaining amount that is not involved in the reaction of each of the curable compounds when the curable compound is irradiated with light, and is involved in the reaction of the first curable compound. When the remaining amount was B1 (% by weight), the amount of the second curable compound in the curable compound was A2 (% by weight), and the total of A1 and A2 was 100% by weight, Means a calculated value.

  Reaction consumption rate R1 = (1− (B1 / A1)) × (A1 + A2) / A1

  The reaction consumption rate R2 of the second curable compound means that the amount of the second curable compound in the curable compound is A2 (% by weight) and GC-MS (gas chromatograph gravimetric analyzer). , When the curable compound is irradiated with light, the remaining amount that is not involved in the reaction of each of the curable compounds is quantified, and the remaining amount that is not involved in the reaction of the second curable compound is B2 ( %), When the amount of the first curable compound in the curable compound is A1 (% by weight) and the total of A1 and A2 is 100% by weight, it means a value calculated from the following formula: .

  Reaction consumption rate R2 = (1− (B2 / A2)) × (A1 + A2) / A1

  Each curable compound after light irradiation when determining the reaction consumption rates R1 and R2 may be the first curable compound or the second curable compound.

  Moreover, the reaction rate C of the said whole curable compound means the value calculated by the following.

  Overall reaction rate C (%) of cured product = (1− (B1 / A1) + (1−B2 / A2)) × 100

  Each curable compound after light irradiation when determining the reaction rate C of the entire curable compound may be the first curable compound or the second curable compound.

[Photocurable compound]
The connection material for electronic parts according to the present invention preferably contains a photocurable compound so as to be cured by light irradiation. The photocurable compound can be semi-cured by light irradiation, and the fluidity of the connection material for electronic parts can be reduced.

  It does not specifically limit as said photocurable compound, A (meth) acrylic resin etc. are mentioned. The photocurable compound is preferably a photocurable compound having a (meth) acryloyl group.

  Since the photocurable compound reacts preferentially and is consumed when irradiated with light, all or part of the photocurable compound is preferably a compound having a methacryloyl group.

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

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

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

  Specific examples of the crosslinkable compound include 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, (poly ) Ethylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, pentaerythritol di (meth) acrylate, 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.

[Thermosetting compound]
From the viewpoint of easily controlling the curing of the connection material for electronic parts and further improving the conduction reliability in the connection structure, the connection material for electronic parts is cured by heating so that the thermosetting compound is cured. It is preferable to contain.

  It does not specifically limit as said thermosetting compound, (meth) acrylic resin etc. are mentioned. The thermosetting compound is preferably a thermosetting compound having a (meth) acryloyl group.

  Since the thermosetting compound is preferentially less reactive and less consumed when irradiated with light, all or part of the thermosetting compound is preferably a compound having an acryloyl group.

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

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

  The thermosetting compound may be a crosslinkable compound or a non-crosslinkable compound. From the viewpoint of further improving connection reliability and conduction reliability, a crosslinkable compound is preferable.

  Specific examples of the crosslinkable compound and the non-crosslinkable compound which are the thermosetting compounds include the compounds exemplified as the crosslinkable compound and the noncrosslinkable compound which are the photocurable compounds.

  When a photocurable compound and a thermosetting compound are used in combination, the blending ratio of the photocurable compound and the thermosetting compound is appropriately adjusted according to the type of the photocurable compound and the thermosetting compound. The In the case where a photocurable compound and a thermosetting compound are used in combination, the electronic component connecting material includes the photocurable compound and the thermosetting compound in a weight ratio of 1:99 to 90:10. Is preferably included at 5:95 to 60:40, more preferably 10:90 to 50:50, and particularly preferably 10:90 to 40:60.

[Photo radical initiator]
The photo radical initiator is not particularly limited. A conventionally known photoradical initiator can be used as the photoradical initiator. As for the said photoradical initiator, only 1 type may be used and 2 or more types may be used together.

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

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

  The content of the photo radical initiator is not particularly limited. The content of the photo radical 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, based on 100 parts by weight of the total amount of the curable compound. The amount is preferably 1 part by weight or less. When the content of the photo radical initiator is not less than the above lower limit and not more than the above upper limit, the connection material for electronic components can be appropriately photocured. By irradiating the connection material for electronic parts with light and forming a B-stage, the flow of the connection material for electronic parts can be suppressed.

[Thermal radical initiator]
The thermal radical initiator is not particularly limited. As the thermal radical initiator, a conventionally known thermal radical initiator can be used. As for the said thermal radical initiator, only 1 type may be used and 2 or more types may be used together. Here, the “thermal radical initiator” means a compound that generates radical species by heating.

  The thermal radical initiator 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 initiator 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 initiator is less than 30 ° C., the storage stability of the connection material for electronic components tends to be reduced. It tends to be difficult to sufficiently cure the connecting material.

  The content of the thermal radical initiator is not particularly limited. The content of the thermal radical initiator is preferably 0.01 parts by weight or more, more preferably 0.05 parts by weight or more, preferably 10 parts by weight or less, based on 100 parts by weight of the total amount of the curable compound. The amount is preferably 5 parts by weight or less. When the content of the thermal radical curing agent is not less than the above lower limit and not more than the above upper limit, the connection material for electronic components can be sufficiently cured.

[Conductive particles]
The conductive particles contained in the anisotropic conductive material electrically connect the electrodes in the first and second connection target members. The conductive particles are not particularly limited as long as they are conductive particles. The surface of the conductive layer of the conductive particles may be covered with an insulating layer. In this case, the insulating layer between the conductive layer and the electrode is excluded when the connection target member is connected. Examples of the conductive particles include conductive particles 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 enhancing the conduction reliability between the electrodes, the conductive particles preferably include resin particles and a conductive layer provided on the surface of the resin particles.

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

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

  The content of the conductive particles is not particularly limited. In 100% by weight of the connection material for electronic parts (anisotropic conductive material), the content of the conductive particles is preferably 0.1% by weight or more, more preferably 0.5% by weight or more, preferably 40% by weight. Below, 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 for the adjacent electrodes that should not be connected to be electrically connected via a plurality of conductive particles. That is, a short circuit between adjacent electrodes can be further prevented.

(Other ingredients)
The electronic component connecting material may contain a solvent. By using the solvent, the viscosity of the connection material for electronic parts can be easily adjusted. Furthermore, for example, when the curable compound is solid, the dispersibility of the curable compound can be improved by adding a solvent to the solid curable compound and dissolving it. Examples of the solvent include ethyl acetate, methyl cellosolve, toluene, acetone, methyl ethyl ketone, cyclohexane, n-hexane, tetrahydrofuran, and diethyl ether.

  Since the adhesive force of the hardened | cured material of the said connection material for electronic components can be improved, it is preferable that the said connection material for electronic components contains an adhesive force regulator. From the viewpoint of further increasing the adhesive strength, the adhesive strength modifier is preferably a silane coupling agent.

  The connection material for electronic parts preferably contains a filler. By using the filler, latent heat expansion of the cured product of the connection material for electronic parts can be suppressed.

  In order to control the viscosity η2 described later and the viscosity ratio (η1 / η2) described later in a suitable range, the filler is preferably surface-treated, and is preferably a hydrophilic filler.

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

  The hydrophilic filler refers to a filler whose surface is covered with a hydrophilic group. Examples of the hydrophilic group include polar groups such as hydroxyl group, amino group, amide group, carboxylate group and carboxyl group, and ionic groups such as carboxylate ion group, sulfonate ion group and ammonium ion group. Examples of the hydrophilic filler include a hydrophilic filler obtained by surface-treating the conventional filler with a hydrophilic surface treatment agent.

Examples of the hydrophilic surface treatment agent include silane coupling agents, titanate coupling agents, aluminum coupling agents, zircoaluminate coupling agents, Al ₂ O ₃ , TiO ₂ , ZrO ₂ , silicone, and stearin. An aluminum acid etc. are mentioned. Among these, a silane coupling agent is preferably used as the hydrophilic surface treatment agent.

  The content of the filler is not particularly limited. The content of the filler is preferably 5 parts by weight or more, more preferably 15 parts by weight or more, preferably 300 parts by weight or less, more preferably 200 parts by weight or less with respect to 100 parts by weight of the total amount of the curable compound. . When the content of the filler is not less than the above lower limit and not more than the above upper limit, latent heat expansion of the cured product of the connection material for electronic components can be sufficiently suppressed, and the filler can be sufficiently dispersed in the connection material for electronic components. it can.

(Other details of connecting materials for electronic parts)
The method for producing the connecting material for electronic parts according to the present invention is not particularly limited, and includes the curable compound, the thermal radical curing agent, the photo radical initiator, and other components added as necessary. The manufacturing method which mix | blends and fully mixes using a planetary stirrer etc. is mentioned.

  About the connecting material for electronic parts according to the present invention, the viscosity after being cured by light irradiation to be B-staged (hereinafter sometimes abbreviated as η3 ′) is preferably 2000 Pa · s or more, preferably 2250 Pa · s or more, preferably 15000 Pa · s or less, more preferably 12000 Pa · s or less, still more preferably 10000 Pa · s or less, particularly preferably 3500 Pa · s or less, and most preferably 3250 Pa · s. The measurement temperature of the viscosity η3 ′ is preferably 20 ° C. or higher, preferably 30 ° C. or lower. The measurement temperature of the viscosity η3 ′ is particularly preferably 25 ° C.

  In the connecting material for electronic parts according to the present invention, when the viscosity at 25 ° C. and 2.5 rpm is η1, and the viscosity at 25 ° C. and 5 rpm is η2, the η2 is 20 Pa · s or more and 200 Pa · s. The viscosity ratio (η1 / η2) of η1 to η2 is preferably 0.9 or more and 1.1 or less. That is, it is preferable that the connection material for electronic components according to the present invention satisfies both the following formulas (X) and (Y).

20 Pa · s ≦ η2 ≦ 200 Pa · s Formula (X)
0.9 ≦ η1 / η2 ≦ 1.1 Formula (Y)

  When a conventional anisotropic conductive material as described in JP-A-2003-064330 is applied to a member to be applied with a dispenser or the like, it may not be applied stably. In an anisotropic conductive material having a viscosity characteristic as described in JP-A-2003-064330, the viscosity is greatly reduced immediately after the start of application, and the anisotropic conductive material may be partially applied in large quantities. is there. For this reason, the coating width is not constant, and as a result, the width or thickness of the cured product layer formed of the anisotropic conductive material tends to vary. On the other hand, in the connection material for electronic parts according to the present invention, the above-mentioned η2 and the ratio (η1 / η2) are within the specific range, so that the connection material for electronic parts can be dispensed by a dispenser or the like. When applying to the application target member, it can be applied more stably and uniformly. Furthermore, it is possible to suppress a partial application of a large amount of the connection material for electronic parts without greatly reducing the viscosity immediately after the start of application. For this reason, the application width can be made constant, and as a result, variations in the width or thickness of the cured product layer obtained by curing the connecting material for electronic components are less likely to occur.

  From the viewpoint of more uniformly applying the electronic component connecting material, η2 is preferably 50 Pa · s or more, more preferably 100 Pa · s or more, preferably 180 Pa · s or less, more preferably 150 Pa · s or less. is there.

  The η2 and the viscosity ratio (η1 / η2) can be adjusted by using a crystalline resin as the curable compound or by using a filler that has been surface-treated to enhance hydrophilicity. From the viewpoint of easily controlling the η2 and the viscosity ratio (η1 / η2) within the above range, the curable compound preferably contains a crystalline resin.

  As a method for curing the connecting material for electronic parts according to the present invention, a method is used in which curing is performed by irradiating the connecting material for electronic parts with light and then cured by heating. By the combined use of photocuring and heat curing, the connection material for electronic components can be cured in a short time, and the connection reliability of the connection target member and the conduction reliability between the electrodes can be improved.

  In addition, the said connection material for electronic components does not need to contain electroconductive particle. In this case, in order to bond and connect the first and second connection target members without electrically connecting the first and second connection target members with the conductive particles, the connection for electronic parts is performed. Materials can be used.

(Connection structure and method of manufacturing connection structure)
A connection structure can be obtained by connecting a connection object member using the connection material for electronic components according to the present invention.

  The connection structure includes a first connection target member, a second connection target member, and a cured product layer connecting the first and second connection target members, and the cured product layer. Is formed by curing the connecting material for electronic parts. The said hardened | cured material layer is a connection part which has connected the said 1st connection object member and the said 2nd connection object member. The first connection target member is a first connection target member having a first electrode on an upper surface, and the second connection target member is a second connection target member having a second electrode on a lower surface. And the electronic component connecting material is an anisotropic conductive material containing conductive particles, and the first electrode and the second electrode are electrically connected by the conductive particles. preferable. By using the connection material for electronic parts according to the present invention, the conduction reliability between the first electrode and the second electrode can be improved.

  The connection material for electronic parts is a connection material used for connecting electronic parts. Preferably, at least one of the first and second connection target members is an electronic component, and both the first and second connection target members are electronic components.

  Next, with reference to the drawings, a connection structure using the connection material for electronic parts according to one embodiment of the present invention and a method for manufacturing the connection structure will be described in more detail.

  In FIG. 1, an example of the connection structure using the connection material for electronic components which concerns on one Embodiment of this invention is typically shown with a partial notch front sectional drawing.

  The connection structure 1 shown in FIG. 1 includes a first connection target member 2, a second connection target member 4, and a cured product layer 3 connecting the first and second connection target members 2 and 4. Is provided. The cured product layer 3 is formed by curing a connecting material for electronic parts including the specific curable compound, the photo radical curing agent, the thermal radical initiator, and the conductive particles 5. Here, an anisotropic conductive material is used as a connection material for electronic components. The anisotropic conductive material includes a plurality of conductive particles 5.

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

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

  The connection structure 1 shown in FIG. 1 can be obtained as follows, for example.

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

  Next, the anisotropic conductive material layer 3A is cured by irradiating the anisotropic conductive material layer 3A with light. By curing the anisotropic conductive material layer 3A, the anisotropic conductive material layer 3A is B-staged. As shown in FIG. 2B, the anisotropic conductive material layer 3 </ b> B (B stage) formed into the B stage on the upper surface 2 a of the first connection target member 2 by forming the anisotropic conductive material layer 3 </ b> A into the B stage. Forming a connection material layer).

  In the B-staged connection material layer, the reaction consumption rate after light irradiation of the first curable compound having the highest reaction consumption rate after light irradiation of the at least two curable compounds is set to the at least Of the two curable compounds, the reaction consumption rate after the light irradiation of the second curable compound having the lowest reaction consumption rate after the light irradiation is preferably 3 times or more. In this case, photocurability can be improved, and connection reliability and conduction reliability can be further improved.

  When the anisotropic conductive material layer 3A is cured and the anisotropic conductive material layer 3A is B-staged, the viscosity η3 of the B-staged anisotropic conductive material layer 3B is 2000 Pa · s or more. The anisotropic conductive material layer 3A is preferably B-staged so that it is 15000 Pa · s or less. By making the viscosity η3 above the lower limit and below the upper limit, the flow of the anisotropic conductive material layer can be sufficiently suppressed. For this reason, the electroconductive particle 5 becomes easy to be arrange | positioned between the 1st, 2nd electrodes 2b and 4b. Furthermore, the anisotropic conductive material layer can be prevented from flowing unintentionally in a region lateral to the outer peripheral surface of the first connection target member 2 or the second connection target member 4.

  From the viewpoint of further suppressing the flow of the anisotropic conductive material layer and the conductive particles 5, the viscosity η3 is preferably 2000 Pa · s or more, preferably 2250 Pa · s or more, preferably 15000 Pa · s or less, more preferably 12000 Pa · s or less, more preferably 10,000 Pa · s or less, particularly preferably 3500 Pa · s or less, and most preferably 3250 Pa · s. The measurement temperature of the viscosity η3 is preferably 20 ° C. or higher, preferably 30 ° C. or lower. The measurement temperature of the viscosity η3 is particularly preferably 25 ° C.

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

When the anisotropic conductive material layer 3A is B-staged by light irradiation, the light irradiation intensity for appropriately proceeding curing of the anisotropic conductive material layer 3A is preferably 0.1 to 100 mW, for example. / Cm ² or so. Moreover, the light irradiation energy for advancing moderately curing of the anisotropic conductive layer 3A is preferably 50 mJ / cm ² or more, more preferably 100 mJ / cm ² or more, preferably 10000 mJ / cm ² or less, more preferably Is 2000 mJ / cm ² or less.

  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 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, as shown in FIG. 2C, the second connection target member 4 is laminated on the upper surface 3a of the B-staged anisotropic conductive material layer 3B. The second connection target member 4 is laminated so that the first electrode 2b on the upper surface 2a of the first connection target member 2 and the second electrode 4b on the lower surface 4a of the second connection target member 4 face each other. To do.

  Further, when the second connection target member 4 is laminated, the anisotropic conductive material layer 3B is heated to further cure the anisotropic conductive material layer 3B, thereby forming the cured product layer 3. However, the anisotropic conductive material layer 3B may be heated before the second connection target member 4 is laminated. Furthermore, it is preferable to heat and cure the anisotropic conductive material layer 3B after the second connection target member 4 is laminated.

  When the anisotropic conductive material layer 3B is cured by heating, the heating temperature for sufficiently curing the anisotropic conductive material layer 3B is preferably 160 ° C or higher, preferably 250 ° C or lower, more preferably 200 ° C. It is as follows.

  It is preferable to apply pressure when the anisotropic conductive material layer 3B is 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. For this reason, conduction reliability can be improved.

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

  When obtaining the connection structure 1, the anisotropic conductive material layer 3A is irradiated with light to form a B-staged anisotropic conductive material layer 3B, and then heat is applied to the anisotropic conductive material layer 3B. It is preferable to do.

  The connection material for electronic parts according to the present invention is a paste-like or film-like connection material for electronic parts, and is preferably a paste-like connection material for electronic parts. The paste-like anisotropic conductive material is an anisotropic conductive paste. The film-like anisotropic conductive material is an anisotropic conductive film. When the anisotropic conductive material is an anisotropic conductive film, a film that does not include conductive particles may be laminated on the anisotropic conductive film that includes the conductive particles.

  When using a paste-like connecting material for electronic components or an anisotropic conductive paste, the curable component and conductive particles are less than when using a film-like connecting material for electronic components or an anisotropic conductive film. It tends to flow and connection reliability and conduction reliability tend to be low. By adopting the above composition in the electronic component connection material according to the present invention, even if a paste-like electronic component connection material or anisotropic conductive paste is used, connection reliability and conduction reliability can be sufficiently improved. .

  The connection structure according to the present invention and the method for manufacturing the connection structure according to the present invention include, for example, connection between a flexible printed circuit board and a glass substrate (FOG (Film on Glass)), 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. Especially, the anisotropic conductive material which is the connection material for electronic components which concerns on this invention is suitable for a COG use. The connection material for electronic parts according to the present invention is preferably a connection material for connecting a semiconductor chip and a glass substrate. In the connection structure according to the present invention and the method for manufacturing the connection structure according to the present invention, it is preferable to use a semiconductor chip and a glass substrate as the first connection target member and the second connection target member.

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

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

Example 1
(1) Preparation of anisotropic conductive paste 20% by weight of methyl methacrylate which is a light and thermosetting compound and 80% by weight of epoxy acrylate which is a light and thermosetting compound (“EBECRYL 3702” manufactured by Daicel-Cytec) A curable compound was prepared.

  100 parts by weight of the curable compound, 0.5 parts by weight of an acylphosphine oxide compound (“DAROCUR TPO” manufactured by Ciba Japan) as a photo radical initiator, and 2,2′-azobis as a thermal radical initiator 0.1 part by weight of 2,4-dimethylvaleronitrile (“V-65” manufactured by Wako Pure Chemical Industries, Ltd., decomposition temperature 51 ° C. for obtaining a 10-hour half-life) and an average particle diameter of 0.25 μm as a filler 20 parts by weight of silica and 20 parts by weight of alumina having an average particle diameter of 0.5 μm are blended, and further, conductive particles having an average particle diameter of 3 μm are contained in 100% by weight of the blend so that the content becomes 10% by weight. After the addition, a blend was obtained by stirring for 5 minutes at 2000 rpm using a planetary stirrer.

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

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

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

On the transparent glass substrate, the obtained anisotropic conductive paste was applied to a thickness of 30 μm to form an anisotropic conductive paste layer. Next, using an ultraviolet irradiation lamp on the anisotropic conductive paste layer, irradiation with ultraviolet light having a wavelength of 365 nm is performed so that the irradiation energy is 1000 mJ / cm ^2, and the anisotropic conductive paste layer is semi-cured by photopolymerization, B stage. Next, the semiconductor chip was stacked on the B-staged anisotropic conductive paste layer so that the electrodes face each other. Then, while adjusting the temperature of the head so that the temperature of the B-staged anisotropic conductive paste layer becomes 185 ° C., a pressure heating head is placed on the upper surface of the semiconductor chip and is anisotropically applied with a pressure of 3 MPa. The conductive paste layer was completely cured at 185 ° C. to obtain a connection structure.

(Example 2)
In the preparation of the anisotropic conductive paste, the conductive particles were used in the same manner as in Example 1 except that the conductive particles were used so that the content in 100% by weight of the blend was 5% by weight. An anisotropic conductive paste having a content of 5% by weight was obtained. A connection structure was obtained in the same manner as in Example 1 except that the obtained anisotropic conductive paste was used.

(Example 3)
In the preparation of the anisotropic conductive paste, the conductive particles were used in the same manner as in Example 1 except that the conductive particles were used so that the content in 100% by weight of the blend was 15% by weight. An anisotropic conductive paste having a content of 15% by weight was obtained. A connection structure was obtained in the same manner as in Example 1 except that the obtained anisotropic conductive paste was used.

Example 4
In the preparation of the anisotropic conductive paste, the conductive particles were used in the same manner as in Example 1 except that the conductive particles were used so that the content in 100% by weight of the composition was 1% by weight. An anisotropic conductive paste having a content of 1 wt% was obtained. A connection structure was obtained in the same manner as in Example 1 except that the obtained anisotropic conductive paste was used.

(Example 5)
In the preparation of the anisotropic conductive paste, the thermal radical initiator is changed to tert-hexyl peroxypivalate (“Perhexyl PV” manufactured by NOF Corporation, decomposition temperature 54.6 ° C. for obtaining a half-life of 10 hours). An anisotropic conductive paste was obtained in the same manner as in Example 1 except that it was changed to. A connection structure was obtained in the same manner as in Example 1 except that the obtained anisotropic conductive paste was used.

(Example 6)
Implemented except that the epoxy acrylate, which is a light and thermosetting compound, was changed to urethane acrylate, which is a light and thermosetting compound ("EBECRYL8804" manufactured by Daicel-Cytec) when preparing the anisotropic conductive paste. In the same manner as in Example 1, an anisotropic conductive paste was obtained. A connection structure was obtained in the same manner as in Example 1 except that the obtained anisotropic conductive paste was used.

(Example 7)
In the preparation of the anisotropic conductive paste, the epoxy acrylate which is a light and thermosetting compound was changed to a hexafunctional acrylate which is a light and thermosetting compound (“KAYARAD DPCA-120” manufactured by Nippon Kayaku Co., Ltd.). Except for this, an anisotropic conductive paste was obtained in the same manner as in Example 1. A connection structure was obtained in the same manner as in Example 1 except that the obtained anisotropic conductive paste was used.

(Example 8)
In the preparation of the anisotropic conductive paste, methyl methacrylate, which is a light and thermosetting compound, is converted into ethoxylated bisphenol A dimethacrylate, which is a light and thermosetting compound (“BPE-100” manufactured by Shin-Nakamura Chemical Co., Ltd.). An anisotropic conductive paste was obtained in the same manner as in Example 1 except that it was changed to. A connection structure was obtained in the same manner as in Example 1 except that the obtained anisotropic conductive paste was used.

Example 9
During the preparation of the anisotropic conductive paste, methyl methacrylate, which is a light and thermosetting compound, was changed to trimethylolpropane trimethacrylate (“TMPT” manufactured by Shin-Nakamura Chemical Co., Ltd.), which is a light and thermosetting compound. Except for this, an anisotropic conductive paste was obtained in the same manner as in Example 1. A connection structure was obtained in the same manner as in Example 1 except that the obtained anisotropic conductive paste was used.

(Examples 10 to 13)
When producing the connection structure, a connection structure was obtained in the same manner as in Example 1 except that the irradiation energy of ultraviolet rays was changed as follows.

Irradiation energy Example 10: 500 mJ / cm ²
Example 11: 800 mJ / cm ²
Example 12: 1200 mJ / cm ²
Example 13: 1500 mJ / cm ²

(Comparative Example 1)
In the preparation of the anisotropic conductive paste, anisotropy was carried out in the same manner as in Example 1 except that methyl methacrylate as a photocurable compound and acylphosphine oxide compound as a photoradical initiator were not used. Conductive paste was obtained. In 100% by weight of the obtained anisotropic conductive paste, the content of conductive particles was 10% by weight. A connection structure was obtained in the same manner as in Example 1 except that the obtained anisotropic conductive paste was used.

(Comparative Example 2)
The anisotropic conductive material obtained in Comparative Example 1 was prepared.

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

  On the upper surface of the transparent glass substrate, the obtained anisotropic conductive paste was applied from a syringe of a dispenser to a thickness of 30 μm to form an anisotropic conductive paste layer. During application and after application, light was not irradiated, thermal polymerization was not performed, and the anisotropic conductive material layer was not B-staged.

  Next, the semiconductor chip was stacked on the upper surface of the anisotropic conductive paste layer that was not B-staged so that the electrodes face each other. Then, while adjusting the temperature of the head so that the temperature of the anisotropic conductive paste layer becomes 185 ° C., a pressure heating head is placed on the upper surface of the semiconductor chip and a pressure of 3 MPa is applied to form the anisotropic conductive paste layer. Completely cured at 185 ° C. to obtain a connection structure.

(Comparative Example 3)
In the preparation of the anisotropic conductive paste, it was carried out except that epoxy acrylate as a thermosetting compound and 2,2′-azobis-2,4-dimethylvaleronitrile as a thermal radical initiator were not used. In the same manner as in Example 1, an anisotropic conductive paste was obtained. In 100% by weight of the obtained anisotropic conductive paste, the content of conductive particles was 10% by weight. A connection structure was obtained in the same manner as in Example 1 except that the obtained anisotropic conductive paste was used.

(Evaluation of Examples and Comparative Examples)
(1) Reaction consumption rate R
When producing the connection structures in Examples 1 to 13, the B-staged anisotropic conductive paste layer was peeled off from the glass substrate with a spatula to obtain a measurement sample. The reaction consumption rate R of the curable compound in the measurement sample was evaluated.

  The evaluation results of the reaction consumption rate R are shown in Table 1 below.

(2) Viscosity Using an E-type viscometer (manufactured by Toki Sangyo Co., Ltd.) under the conditions of 25 ° C. and 2.5 rpm, the obtained anisotropic conductive paste (viscosity of the anisotropic conductive paste before application) The viscosity η1 was measured. Moreover, viscosity η2 of the obtained anisotropic conductive paste was measured using an E-type viscometer (manufactured by Toki Sangyo Co., Ltd.) at 25 ° C. and 5 rpm.

(3) Presence or absence of leakage Using the obtained connection structure, it was measured with a tester whether or not leakage occurred in 20 adjacent electrodes.

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

(5) Viscosity of the B-staged anisotropic conductive paste layer After the anisotropic conductive paste layer is B-staged by photopolymerization, on the upper surface of the B-staged anisotropic conductive paste layer The viscosity η3 of the B-staged anisotropic conductive paste layer immediately before stacking the semiconductor chips was measured using a rheometer (manufactured by Anton Paar) at 25 ° C. and 2.5 rpm.

(6) Variation in coating width The obtained anisotropic conductive paste was filled into a syringe with a nozzle diameter of 1.1 mm, and using a dispenser, the pressure was 300 Pa, the coating thickness was 30 μm, the moving speed was 10 mm / s, the coating line distance was 20 mm, and An anisotropic conductive paste was applied on a glass substrate under the condition of an application width of 1 mm.

  The application width at each point of 2 mm, 5 mm, and 10 mm from the application start point of the anisotropic conductive paste was measured with a microscope with a length measuring function.

(7) Height (thickness) of cured product layer
An anisotropic conductive paste was applied on a glass substrate in the same manner as in the evaluation of (6) above. Immediately after the application, ultraviolet rays were irradiated to initiate photocuring of the anisotropic conductive paste. Further, 10 seconds after the irradiation with ultraviolet rays, the glass substrate coated with the anisotropic conductive paste was placed in an oven at 150 ° C. for 5 minutes to thermally cure the anisotropic conductive paste. The height of the cured product layer formed by curing the anisotropic conductive paste was measured with a micrometer.

  The evaluation results of the evaluation items (2) to (7) are shown in Table 2 below.

DESCRIPTION OF SYMBOLS 1 ... Connection structure 2 ... 1st connection object member 2a ... Upper surface 2b ... 1st electrode 3 ... Hardened | cured material layer 3a ... Upper surface 3A ... Anisotropic conductive material layer 3B ... B-staged anisotropic conductive material Layer 4 ... second connection target member 4a ... lower surface 4b ... second electrode 5 ... conductive particles

Claims (15)

It is a connecting material for electronic parts that is cured by heating after curing by light irradiation,
Contains at least two curable compounds selected from the group consisting of a curable compound having a methacryloyl group, a curable compound having an acryloyl group, and a curable compound having a vinyl group, or at least having a different Q value Contains two curable compounds,
A connection material for electronic parts, further comprising a photo radical initiator and a thermal radical initiator. It is a connecting material for electronic parts that is cured by heating after curing by light irradiation,
At least two curable compounds selected from the group consisting of a curable compound having a methacryloyl group, a curable compound having an acryloyl group, and a curable compound having a vinyl group;
A photo radical initiator;
The connection material for electronic components according to claim 1, comprising a thermal radical initiator. It is a connecting material for electronic parts that is cured by heating after curing by light irradiation,
At least two curable compounds having different Q values;
A photo radical initiator;
The electronic component connecting material according to claim 1, comprising a thermal radical initiator.   The at least 2 sort (s) of curable compound from which said Q value differs is a curable compound which has a methacryloyl group, a curable compound which has an acryloyl group, or a curable compound which has a vinyl group, respectively. Electronic component connection material.   The at least two curable compounds having different Q values are at least two selected from the group consisting of a curable compound having a methacryloyl group, a curable compound having an acryloyl group, and a curable compound having a vinyl group. The electronic component connecting material according to claim 1, which is a curable compound.   Among the at least two curable compounds having different Q values, the Q value of the first curable compound having the highest Q value has the highest Q value among the at least two curable compounds having different Q values. The electronic component connecting material according to any one of claims 1, 3, 4, and 5, which is 0.1 or more higher than a Q value of a low second curable compound.   When the reaction rate of the entire curable compound contained in the connecting material for electronic parts reaches 20%, the first reaction consumption rate after light irradiation of the at least two curable compounds is the highest. The reaction consumption rate after light irradiation of the curable compound is 3 of the reaction consumption rate after light irradiation of the second curable compound having the lowest reaction consumption rate after light irradiation of the at least two curable compounds. The connection material for electronic components according to any one of claims 1 to 6, which is twice or more. The curable compound includes a curable compound having a methacryloyl group and a curable compound having an acryloyl group,
The connection material for electronic components according to claim 1, wherein the curable compound does not include or includes a curable compound having a vinyl group.   The connection material for electronic components according to claim 1, further comprising conductive particles and being an anisotropic conductive material.   The connection material for electronic components according to claim 1, further comprising conductive particles, which is a paste-like anisotropic conductive paste. A first connection target member, a second connection target member, and a cured product layer connecting the first and second connection target members,
The connection structure in which the said hardened | cured material layer is formed by hardening the connection material for electronic components of any one of Claims 1-10. The first connection target member has a first electrode on the upper surface, the second connection target member has a second electrode on the lower surface,
The electronic component connecting material is an anisotropic conductive material containing conductive particles,
The connection structure according to claim 11, wherein the first electrode and the second electrode are electrically connected by the conductive particles. A step of forming a connection material layer using the connection material for an electronic component according to any one of claims 1 to 10 on the first connection target member;
Curing the connection material layer by irradiating light to form a B-staged connection material layer; and
A step of laminating a second connection target member on the B-staged connection material layer;
A method of manufacturing a connection structure, comprising: heating the B-staged connection material layer to perform main curing to form a cured product layer. A first connection target member having a first electrode on the upper surface is used as the first connection target member, and a second connection target member having a second electrode on the lower surface is used as the second connection target member. Use
As the connection material for electronic parts, an anisotropic conductive material containing conductive particles is used,
The method for manufacturing a connection structure according to claim 13, wherein the first electrode and the second electrode are electrically connected by the conductive particles.   In the B-staged connection material layer, the reaction consumption rate after light irradiation of the first curable compound having the highest reaction consumption rate after light irradiation of the at least two curable compounds is set to the at least The connection structure according to claim 13 or 14, wherein a reaction consumption rate after light irradiation of the second curable compound having the lowest reaction consumption rate after light irradiation of two kinds of curable compounds is set to three times or more. Body manufacturing method.

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