JP2021057292A - Connection structure and method for manufacturing connection structure - Google Patents

Abstract

To provide a connection structure capable of effectively suppressing occurrence of solder flash.SOLUTION: In a connection structure, a first connection target member and a second connection target member are connected by a connecting portion. The connecting portion has a solder portion and a cured product portion. The solder portion in the connecting portion is arranged between an upper surface of a first electrode and a lower surface of a second electrode so as to electrically connect the first electrode and the second electrode, and the cured product portion in the connecting portion is arranged on a side surface of the solder portion. When the width of the cured product portion is L μm and the distance between the adjacent first electrodes is La μm on a cross-section in a lamination direction of the first electrode, the connecting portion, and the second electrode, the following formula (1) is satisfied: 10≤L<La/2 (1).SELECTED DRAWING: Figure 1

Description

The present invention relates to a connection structure including a connection portion. The present invention also relates to a method for manufacturing the above-mentioned connection structure.

Solder pastes and anisotropic conductive materials may be used to connect electronic components such as semiconductor chips to substrates. Examples of the anisotropic conductive material include an anisotropic conductive paste and an anisotropic conductive film. In the anisotropic conductive material, conductive particles are dispersed in the binder.

The anisotropic conductive material is used to obtain various connection structures. Examples of the connection using the anisotropic conductive material include 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)), and a semiconductor. Examples thereof include a connection between a chip and a glass substrate (COG (Chip on Glass)) and a connection between a flexible printed circuit board and a glass epoxy substrate (FOB (Film on Board)).

With the anisotropic conductive material, for example, when the electrode of the flexible printed circuit board and the electrode of the glass epoxy board are electrically connected, the anisotropic conductive material containing conductive particles is arranged on the glass epoxy board. To do. Next, the flexible printed circuit boards are laminated and heated and pressurized. As a result, the anisotropic conductive material is cured, and the electrodes are electrically connected to each other via the conductive particles to obtain a connection structure.

Patent Document 1 below discloses a method for mounting an electronic component that joins an electrode provided on the lower surface of the electronic component and an electrode formed on a substrate by using a solder paste containing a thermosetting resin as a binder component. There is. In the method of mounting the electronic component, the amount of the solder paste supplied to the joint where the distance between the lower surface of the electronic component and the upper surface of the substrate is narrowed due to the warp of the substrate is adjusted to be small.

Japanese Unexamined Patent Publication No. 2015-115500

Solder pastes and anisotropic conductive materials may be used to connect electronic components such as semiconductor chips to substrates.

However, when the electronic component and the substrate are connected and then heated by reflow or the like in order to connect to another substrate, solder flash may occur in which the solder remelts and leaks out.

Further, in recent years, the pitch of electrodes has been narrowed due to the miniaturization of electronic components, and the problem of solder flash has become more prominent due to the narrowing of pitch of electrodes.

An object of the present invention is to provide a connection structure capable of effectively suppressing the occurrence of solder flash. Another object of the present invention is to provide a method for manufacturing the above-mentioned connection structure.

According to a broad aspect of the present invention, a first connection target member having a plurality of first electrodes on the upper surface, a second connection target member having a plurality of second electrodes on the lower surface, and the first connection target member. The first electrode and the second electrode are opposed to each other via the connection portion, and the connection portion is provided with a connection portion connecting the second electrode and the second connection target member. The upper surface of the first electrode has a solder portion and a cured product portion so that the solder portion in the connection portion electrically connects the first electrode and the second electrode. The cured product portion in the connecting portion is arranged on the side surface of the solder portion, and the first electrode and the connecting portion are arranged between the first electrode and the lower surface of the second electrode. A connecting structure that satisfies the following formula (1) when the width of the cured product portion is L μm and the distance between adjacent first electrodes is La μm in the cross section in the stacking direction with the second electrode. Is provided.

10 ≦ L <La / 2 equation (1)

In a specific aspect of the connection structure according to the present invention, the width of the cured product portion is L μm in the cross section in the stacking direction of the first electrode, the connection portion, and the second electrode, and the adjacent first electrode is provided. When the distance between the electrodes of 2 is Lbμm, the following equation (2) is satisfied.

10 ≦ L <Lb / 2 equation (2)

According to a broad aspect of the present invention, a conductive material containing a plurality of solder particles and a binder is used to dispose the conductive material on the surface of a first connection target member having a plurality of first electrodes on the upper surface. A second connection target member having a plurality of second electrodes on the lower surface on the surface opposite to the first connection target member side of the conductive material in the first arrangement step is referred to as the first electrode. The first connection target member and the second connection target are formed by heating the conductive material to a temperature equal to or higher than the melting point of the solder particles in the second placement step of arranging the second electrodes so as to face each other. A connection portion forming step of forming a connection portion connecting a member with the conductive material is provided, the connection portion has a solder portion and a cured product portion, and the solder portion in the connection portion is provided. Is arranged between the upper surface of the first electrode and the lower surface of the second electrode so as to electrically connect the first electrode and the second electrode. The cured product portion inside is arranged on the side surface of the solder portion, and the width of the cured product portion is set in the cross section in the stacking direction of the first electrode, the connecting portion, and the second electrode. A method for manufacturing a connecting structure that satisfies the following formula (3) is provided, where L μm and the distance between the adjacent first electrodes are La μm.

10 ≦ L <La / 2 equation (3)

In a specific aspect of the method for manufacturing a connection structure according to the present invention, the width of the cured product portion is L μm and adjacent to each other in a cross section in the stacking direction of the first electrode, the connection portion, and the second electrode. The following equation (4) is satisfied when the matching distance between the second electrodes is Lbμm.

10 ≦ L <Lb / 2 equation (4)

In a specific aspect of the method for manufacturing a connecting structure according to the present invention, the conductive material is arranged only on the surface of the first electrode in the first arrangement step.

The connection structure according to the present invention includes a first connection target member having a plurality of first electrodes on the upper surface, a second connection target member having a plurality of second electrodes on the lower surface, and the first connection target member. It is provided with a connecting portion connecting the above-mentioned second connecting target member and the above-mentioned second connecting target member. In the connection structure according to the present invention, the first electrode and the second electrode face each other via the connection portion. In the connection structure according to the present invention, the connection portion has a solder portion and a cured product portion. In the connection structure according to the present invention, the upper surface of the first electrode and the first electrode are such that the solder portion in the connection portion electrically connects the first electrode and the second electrode. It is arranged between the lower surface of the electrode 2 and the lower surface of the electrode 2. In the connection structure according to the present invention, the cured product portion in the connection portion is arranged on the side surface of the solder portion. In the connection structure according to the present invention, in the cross section of the first electrode, the connection portion, and the second electrode in the stacking direction, the width of the cured product portion is Lμm, and the distance between the adjacent first electrodes is Lμm. Is La μm, the above equation (1) is satisfied. Since the connection structure according to the present invention has the above configuration, it is possible to effectively suppress the occurrence of solder flash.

In the method for manufacturing a connection structure according to the present invention, the conductive material containing a plurality of solder particles and a binder is used, and the conductive material is placed on the surface of a first connection target member having a plurality of first electrodes on the upper surface. The first placement step of arranging the particles is provided. In the method for manufacturing a connection structure according to the present invention, a second connection target member having a plurality of second electrodes on the lower surface is provided on a surface of the conductive material opposite to the first connection target member side. A second arrangement step of arranging the first electrode and the second electrode so as to face each other is provided. In the method for manufacturing a connection structure according to the present invention, the conductive material is heated above the melting point of the solder particles to connect the first connection target member and the second connection target member. The portion is provided with a connection portion forming step of forming the portion from the conductive material. In the method for manufacturing a connection structure according to the present invention, the connection portion has a solder portion and a cured product portion. In the method for manufacturing a connection structure according to the present invention, the upper surface of the first electrode is such that the solder portion in the connection portion electrically connects the first electrode and the second electrode. It is arranged between the surface and the lower surface of the second electrode. In the method for manufacturing a connection structure according to the present invention, the cured product portion in the connection portion is arranged on the side surface of the solder portion. In the method for manufacturing a connecting structure according to the present invention, in the cross section of the first electrode, the connecting portion, and the second electrode in the stacking direction, the width of the cured product portion is Lμm, and the adjacent first The above equation (3) is satisfied when the distance between the electrodes is La μm. Since the above-mentioned configuration is provided in the method for manufacturing a connection structure according to the present invention, the occurrence of solder flash can be effectively suppressed.

FIG. 1 is a cross-sectional view schematically showing a connection structure according to an embodiment of the present invention. 2 (a) to 2 (c) are cross-sectional views for explaining each step of an example of a method for manufacturing a connection structure according to an embodiment of the present invention. FIG. 3 is a cross-sectional view showing a modified example of the connection structure.

The details of the present invention will be described below.

(Connecting structure and manufacturing method of connecting structure)
The connection structure according to the present invention includes a first connection target member having a plurality of first electrodes on the upper surface, a second connection target member having a plurality of second electrodes on the lower surface, and the first connection target member. It is provided with a connecting portion for connecting the above-mentioned second member to be connected. In the connection structure according to the present invention, the first electrode and the second electrode face each other via the connection portion. In the connection structure according to the present invention, the connection portion has a solder portion and a cured product portion. In the connection structure according to the present invention, the upper surface of the first electrode and the first electrode are such that the solder portion in the connection portion electrically connects the first electrode and the second electrode. It is arranged between the lower surface of the electrode 2 and the lower surface of the electrode 2. In the connection structure according to the present invention, the cured product portion in the connection portion is arranged on the side surface of the solder portion. In the connection structure according to the present invention, in the cross section of the first electrode, the connection portion, and the second electrode in the stacking direction, the width of the cured product portion is Lμm, and the distance between the adjacent first electrodes is Lμm. Is La μm, the following equation (1) is satisfied.

10 ≦ L <La / 2 equation (1)

In the connection structure, in the cross section of the first electrode, the connection portion, and the second electrode in the stacking direction, the width of the cured product portion is Lμm, and the distance between the adjacent second electrodes is Lbμm. Then, it is preferable to satisfy the following formula (2).

10 ≦ L <Lb / 2 equation (2)

When using the connection structure, the connection structure may be used so that the first connection target member is on the lower side and the second connection target member is on the upper side, and the first connection target member is on the lower side. A connection structure may be used so that the second connection target member is not on the upper side.

Since the connection structure according to the present invention has the above configuration, it is possible to effectively suppress the occurrence of solder flash.

In the method for manufacturing a connection structure according to the present invention, the conductive material containing a plurality of solder particles and a binder is used, and the conductive material is placed on the surface of a first connection target member having a plurality of first electrodes on the upper surface. The first placement step of arranging the particles is provided. In the method for manufacturing a connection structure according to the present invention, a second connection target member having a plurality of second electrodes on the lower surface is provided on a surface of the conductive material opposite to the first connection target member side. A second arrangement step of arranging the first electrode and the second electrode so as to face each other is provided. In the method for manufacturing a connection structure according to the present invention, the conductive material is heated above the melting point of the solder particles to connect the first connection target member and the second connection target member. The portion is provided with a connection portion forming step of forming the portion from the conductive material. In the method for manufacturing a connection structure according to the present invention, the connection portion has a solder portion and a cured product portion. In the method for manufacturing a connection structure according to the present invention, the upper surface of the first electrode is such that the solder portion in the connection portion electrically connects the first electrode and the second electrode. It is arranged between the surface and the lower surface of the second electrode. In the method for manufacturing a connection structure according to the present invention, the cured product portion in the connection portion is arranged on the side surface of the solder portion. In the method for manufacturing a connecting structure according to the present invention, in the cross section of the first electrode, the connecting portion, and the second electrode in the stacking direction, the width of the cured product portion is Lμm, and the adjacent first When the distance between the electrodes is La μm, the following equation (3) is satisfied.

10 ≦ L <La / 2 equation (3)

In the method for manufacturing the connection structure, the width of the cured product portion is Lμm and the distance between the adjacent second electrodes in the cross section in the stacking direction of the first electrode, the connection portion, and the second electrode. It is preferable that the following formula (4) is satisfied when Lb μm is used.

10 ≦ L <Lb / 2 equation (4)

Since the above-mentioned configuration is provided in the method for manufacturing a connection structure according to the present invention, the occurrence of solder flash can be effectively suppressed.

In the connection structure, the distance between the upper surface of the first electrode and the lower surface of the second electrode is preferably 5 μm or more, more preferably 30 μm or more, preferably 100 μm or less, more preferably 75 μm. It is as follows. When the distance between the upper surface of the first electrode and the lower surface of the second electrode is equal to or greater than the lower limit and equal to or lower than the upper limit, the insulation reliability is further improved when the electrodes are electrically connected. It can be effectively enhanced, and further, the conduction reliability can be enhanced even more effectively.

In the method for manufacturing a connection structure according to the present invention, pressurization may not be performed in the step of forming the connection portion, and pressurization may be performed in the step of forming the connection portion. In the method for manufacturing a connection structure according to the present invention, in the step of forming the connection portion, a pressurizing pressure exceeding the weight force of the connection target member may not be applied to the conductive material, and the connection target member may be manufactured. Pressurizing pressure that exceeds the force of weight may be applied.

Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a cross-sectional view schematically showing a connection structure according to an embodiment of the present invention. In the drawings below, the size, thickness, shape, etc. may differ from the actual size, thickness, shape, etc. for convenience of illustration.

The connection structure 1 shown in FIG. 1 is a connection connecting the first connection target member 2, the second connection target member 3, the first connection target member 2, and the second connection target member 3. It includes a part 4. The first connection target member 2 has a first electrode 2a on the upper surface. The second connection target member 3 has a second electrode 3a on the lower surface. In the connection structure 1, the first electrode 2a and the second electrode 3a face each other via the connection portion 4. In the connection structure 1, the connection portion 4 has a solder portion 4A and a cured product portion 4B. The solder portion is preferably formed by joining a plurality of solder particles to each other. The cured product portion is preferably formed by thermosetting a binder containing a thermosetting component.

The solder portion 4A in the connection portion 4 is between the upper surface of the first electrode 2a and the lower surface of the second electrode 3a so as to electrically connect the first electrode 2a and the second electrode 3a. Have been placed. Therefore, the first connection target member 2 and the second connection target member 3 are electrically connected by the solder portion 4A.

The cured product portion 4B in the connecting portion 4 is arranged on the side surface of the solder portion 4A. It is preferable that the cured products are not in contact with each other between adjacent electrodes. There may be voids between the cured products between adjacent electrodes. Between adjacent electrodes, there may be a region in which the cured product portion does not exist. The cured product portions may be in contact with each other between adjacent electrodes.

As shown in FIG. 1, in the connection structure 1, after a plurality of solder particles are melted between the first electrode 2a and the second electrode 3a, the melt of the solder particles wets and spreads on the surface of the electrodes. After that, it solidifies to form the solder portion 4A. Therefore, the contact area between the solder portion 4A and the first electrode 2a and the contact area between the solder portion 4A and the second electrode 3a become large. That is, by using the solder particles, the solder portion 4A, the first electrode 2a, and the solder portion are compared with the case where the conductive outer surface is a metal such as nickel, gold, or copper. The contact area between the 4A and the second electrode 3a becomes large. This also increases the continuity reliability and connection reliability of the connection structure 1. Further, in the connection structure 1, when the solder portion 4A is formed, the binder containing the thermosetting component extruded to the outside is thermally cured, so that the cured product portion 4B is formed on the side surface of the solder portion 4A. Has been done. When the conductive material contains flux, the flux is generally gradually deactivated by heating.

In the connection structure, the width (L in FIG. 1) of the cured product portion arranged on the side surface of the solder portion is preferably 10 μm or more, more preferably 50 μm or more, preferably 100 μm or less, and more. It is preferably 70 μm or less. The width of the cured product portion (L in FIG. 1) is preferably a dimension that maximizes the width of the cured product portion. When the width of the cured product portion is not less than the above lower limit and not more than the above upper limit, the insulation reliability can be further effectively improved when the electrodes are electrically connected, and the conduction reliability can be further improved. It can be enhanced even more effectively. When the width of the cured product portion is not less than the above lower limit and not more than the above upper limit, the occurrence of solder flash can be suppressed more effectively.

The width of the cured product portion arranged on the side surface of the solder portion means the maximum width of the cured product portion located on the side surface of the solder portion. For example, in FIG. 1, the cured product portion has a recess, but the maximum width of the cured product, which is the portion that covers the solder portion 4A most thickly, is L.

In the connection structure, the distance between adjacent first electrodes (La in FIG. 1) is preferably 300 μm or less, more preferably 200 μm or less. The distance between the first electrodes adjacent to each other (La in FIG. 1) may be 100 μm or less. The lower limit of the distance between the first electrodes adjacent to each other is not particularly limited. In the connection structure, the "La / 2" portion in the above formula (1) and the above formula (3) is preferably La / 4, more preferably La / 3, and even more preferably La / 2. In the connection structure, the distance between adjacent second electrodes (Lb in FIG. 1) is preferably 300 μm or less, more preferably 200 μm or less. The distance between the adjacent second electrodes (Lb in FIG. 1) may be 100 μm or less. The lower limit of the distance between the second electrodes adjacent to each other is not particularly limited. In the connection structure, the "Lb / 2" portion in the above formula (2) and the above formula (4) is preferably Lb / 4, more preferably Lb / 3, and even more preferably Lb / 2. When the connection structure satisfies the above preferred embodiment, the insulation reliability can be further effectively enhanced when the electrodes are electrically connected, and the conduction reliability can be further enhanced. Can be effectively enhanced.

In the connection structure 1 shown in FIG. 1, all of the solder portions 4A are located in facing regions between the first electrode 2a and the second electrode 3a. In the connection structure 1X of the modified example shown in FIG. 3, only the connection portion 4X is different from the connection structure 1 shown in FIG. The connection portion 4X has a solder portion 4XA and a cured product portion 4XB. Like the connection structure 1X, most of the solder portion 4XA is located in the region where the first electrode 2a and the second electrode 3a face each other, and a part of the solder portion 4XA is the first electrode 2a. And may protrude laterally from the facing region of the second electrode 3a. The solder portion 4XA protruding laterally from the facing region of the first electrode 2a and the second electrode 3a is a part of the solder portion 4XA, and is not a solder particle separated from the solder portion 4XA. In this embodiment, the amount of solder particles separated from the solder portion can be reduced, but the solder particles separated from the solder portion may be present in the cured product portion.

If the amount of solder particles used is reduced, it becomes easy to obtain the connection structure 1. If the amount of solder particles used is increased, it becomes easy to obtain the connection structure 1X.

In the connection structures 1 and 1X, when the portions where the first electrode 2a and the second electrode 3a face each other are seen in the stacking direction of the first electrode 2a, the connection portions 4, 4X and the second electrode 3a. It is preferable that the solder portions 4A and 4XA in the connecting portions 4 and 4X are arranged in 50% or more of the area of 100% of the portions of the first electrode 2a and the second electrode 3a facing each other. .. When the solder portions 4A and 4XA in the connection portions 4 and 4X satisfy the above-mentioned preferable aspects, the continuity reliability can be further improved.

When the portion where the first electrode and the second electrode face each other is seen in the stacking direction of the first electrode, the connection portion, and the second electrode, the first electrode and the first electrode are seen. It is preferable that the solder portion in the connection portion is arranged in 50% or more of the area of 100% of the portions facing the electrodes of 2. When the portion where the first electrode and the second electrode face each other is seen in the stacking direction of the first electrode, the connection portion, and the second electrode, the first electrode and the first electrode are seen. It is more preferable that the solder portion in the connection portion is arranged in 60% or more of the area of 100% of the portions facing the electrodes of 2. When the portion where the first electrode and the second electrode face each other is seen in the stacking direction of the first electrode, the connection portion, and the second electrode, the first electrode and the first electrode are seen. It is more preferable that the solder portion in the connection portion is arranged in 70% or more of the area of 100% of the portions facing the electrodes of 2. When the portion where the first electrode and the second electrode face each other is seen in the stacking direction of the first electrode, the connection portion, and the second electrode, the first electrode and the first electrode are seen. It is particularly preferable that the solder portion in the connection portion is arranged in 80% or more of the area of 100% of the portions facing the electrodes of 2. When the portion where the first electrode and the second electrode face each other is seen in the stacking direction of the first electrode, the connection portion, and the second electrode, the first electrode and the first electrode are seen. It is most preferable that the solder portion in the connection portion is arranged in 90% or more of the area of 100% of the portions facing the electrodes of 2. When the solder portion in the connection portion satisfies the above-mentioned preferable embodiment, the continuity reliability can be further improved.

When the portions facing each other of the first electrode and the second electrode are viewed in a direction orthogonal to the stacking direction of the first electrode, the connection portion, and the second electrode, the first electrode is used. It is preferable that 60% or more of the solder portion in the connection portion is arranged at the portion where the electrode and the second electrode face each other. When the portions facing each other of the first electrode and the second electrode are viewed in a direction orthogonal to the stacking direction of the first electrode, the connection portion, and the second electrode, the first electrode is used. It is more preferable that 70% or more of the solder portion in the connection portion is arranged at the portion where the electrode and the second electrode face each other. When the portions facing each other of the first electrode and the second electrode are viewed in a direction orthogonal to the stacking direction of the first electrode, the connection portion, and the second electrode, the first electrode is used. It is more preferable that 90% or more of the solder portion in the connection portion is arranged at the portion where the electrode and the second electrode face each other. When the portions facing each other of the first electrode and the second electrode are viewed in a direction orthogonal to the stacking direction of the first electrode, the connection portion, and the second electrode, the first electrode is used. It is particularly preferable that 95% or more of the solder portion in the connection portion is arranged at the portion where the electrode and the second electrode face each other. When the portions facing each other of the first electrode and the second electrode are viewed in a direction orthogonal to the stacking direction of the first electrode, the connection portion, and the second electrode, the first electrode is used. It is most preferable that 99% or more of the solder portion in the connection portion is arranged at the portion where the electrode and the second electrode face each other. When the solder portion in the connection portion satisfies the above-mentioned preferable embodiment, the continuity reliability can be further improved.

Next, FIG. 2 describes an example of a method for manufacturing a connection structure according to an embodiment of the present invention.

First, the first connection target member 2 having the first electrode 2a on the upper surface is prepared. Next, as shown in FIG. 2A, the conductive material 11 containing the binder 11B and the solder particles 11A is arranged on the surface (upper surface) of the first connection target member 2 (first step, first step, First placement step). In the first placement step, it is preferable to place the conductive material only on the surface of the first electrode. The conductive material 11 used preferably contains a thermosetting component as the binder 11B. The thermosetting component preferably contains a thermosetting compound and a thermosetting agent.

The conductive material 11 is arranged on the surface of the first connection target member 2 on which the first electrode 2a is provided. After the placement of the conductive material 11, the solder particles 11A are preferably placed only on the first electrode 2a. After the arrangement of the conductive material, the solder particles may be arranged on both the first electrode and the region where the first electrode is not formed.

The method of arranging the conductive material 11 is not particularly limited, and examples thereof include coating with a dispenser, screen printing, and ejection with an inkjet device.

Further, a second connection target member 3 having the second electrode 3a on the lower surface is prepared. Next, as shown in FIG. 2B, in the conductive material 11 on the first electrode 2a of the first connection target member 2, on the surface of the conductive material 11 on the side opposite to the first electrode 2a side. The second connection target member 3 is arranged in (second step, second arrangement step). The second connection target member 3 is arranged on the surface of the conductive material 11 from the second electrode 3a side. At this time, the first electrode 2a and the second electrode 3a are opposed to each other. It is preferable that the positions of the electrodes of the first electrode and the second electrode are not displaced.

In the second arrangement step, when the second connection target member is pressed, the conductive material 11 preferably contains a gap material. Since the conductive material 11 contains the gap material, even if the second connection target member 3 is pressurized, the gap material maintains the distance between the first electrode 2a and the second electrode 3a. When the conductive material 11 contains the gap material, it is preferable that the gap material is brought into contact with both the first electrode 2a and the second electrode 3a in the second arrangement step. In the second arrangement step, it is preferable that the solder particles 11A (per one) are not brought into contact with both the first electrode 2a and the second electrode 3a.

The distance between the first electrode and the second electrode in the second arrangement step is preferably 30 μm or more, more preferably 50 μm or more, preferably 150 μm or less, and more preferably 100 μm or less. When the distance between the first electrode and the second electrode in the second arrangement step is equal to or greater than the lower limit and equal to or lower than the upper limit, the conduction reliability between the upper and lower electrodes to be connected is further enhanced. be able to.

Next, the conductive material 11 is heated above the melting point of the solder particles 11A (third step, connection step). Preferably, the conductive material 11 is heated above the curing temperature of the binder 11B (thermosetting component). During this heating, the solder particles 11A melt and join to each other. In addition, the binder 11B is thermoset. As a result, as shown in FIG. 2C, the connecting portion 4 connecting the first connecting target member 2 and the second connecting target member 3 is formed of the conductive material 11. The connecting portion 4 is formed by the conductive material 11, the solder portion 4A is formed by joining the plurality of solder particles 11, and the cured product portion 4B is formed by thermosetting the binder 11B.

The distance between the first electrode and the second electrode in the connection step is preferably 5 μm or more, more preferably 30 μm or more, preferably 100 μm or less, and more preferably 75 μm or less. When the distance between the first electrode and the second electrode in the second arrangement step is equal to or greater than the lower limit and equal to or lower than the upper limit, the conduction reliability between the upper and lower electrodes to be connected is further enhanced. be able to.

In this way, the connection structure 1 shown in FIG. 1 is obtained. The second step and the third step may be continuously performed. Further, after performing the second step, the obtained laminate of the first connection target member 2, the conductive material 11, and the second connection target member 3 is moved to the heating unit, and the third The process may be performed. In order to perform the heating, the laminate may be arranged on the heating member, or the laminate may be arranged in the heated space.

The heating temperature in the third step is preferably 140 ° C. or higher, more preferably 160 ° C. or higher, preferably 450 ° C. or lower, more preferably 250 ° C. or lower, still more preferably 200 ° C. or lower.

As a heating method in the third step, a method of heating the entire connection structure using a reflow furnace or an oven above the melting point of the solder particles and above the curing temperature of the binder (thermosetting component) can be used. , A method of locally heating only the connection portion of the connection structure can be mentioned.

Examples of the appliance used for the method of locally heating include a hot plate, a heat gun for applying hot air, a soldering iron, an infrared heater, and the like.

When locally heating on a hot plate, use a metal with high thermal conductivity directly under the connection, and use a material with low thermal conductivity such as fluororesin in other areas where heating is not preferable. , It is preferable to form the upper surface of the hot plate.

The first connection target member and the second connection target member are not particularly limited. Specific examples of the first connection target member and the second connection target member include a semiconductor chip, a semiconductor package, an LED chip, an LED package, electronic components such as a capacitor and a diode, and a resin film, a printed circuit board, and the like. Examples thereof include electronic components such as flexible printed circuit boards, flexible flat cables, rigid flexible boards, glass epoxy boards, and circuit boards such as glass boards. The first connection target member and the second connection target member are preferably electronic components.

It is preferable that at least one of the first connection target member and the second connection target member is a resin film, a flexible printed circuit board, a flexible flat cable, or a rigid flexible substrate. The second connection target member is preferably a resin film, a flexible printed circuit board, a flexible flat cable, or a rigid flexible substrate.

Examples of the electrode provided on the connection target member include a gold electrode, a nickel electrode, a tin electrode, an aluminum electrode, a copper electrode, a molybdenum electrode, a silver electrode, a SUS electrode, and a metal electrode such as a tungsten electrode. When the connection target member is a flexible printed substrate, the electrode is preferably a gold electrode, a nickel electrode, a tin electrode, a silver electrode, or a copper electrode. When the member to be connected is a glass substrate, the electrodes are preferably aluminum electrodes, copper electrodes, molybdenum electrodes, silver electrodes or tungsten electrodes. When the electrode is an aluminum electrode, it may be an electrode formed only of aluminum, or an electrode in which an aluminum layer is laminated on the surface of a metal oxide layer. Examples of the material of the metal oxide layer include indium oxide doped with a trivalent metal element and zinc oxide doped with a trivalent metal element. Examples of the trivalent metal element include Sn, Al and Ga.

The details of the conductive material will be described below.

(Conductive material)
The conductive material is used in the above-mentioned connection structure and the method for manufacturing the connection structure. The conductive material contains a plurality of solder particles and a binder.

From the viewpoint of more efficiently arranging the solder particles on the electrodes, the conductive material is preferably liquid at 25 ° C., and is preferably a conductive paste.

From the viewpoint of more efficiently arranging the solder particles on the electrodes, the viscosity (η25) of the conductive material at 25 ° C. is preferably 30 Pa · s or more, more preferably 50 Pa · s or more, and preferably 50 Pa · s or more. It is 400 Pa · s or less, more preferably 300 Pa · s or less. The viscosity (η25) can be appropriately adjusted depending on the type and amount of the compounding components.

The viscosity (η25) can be measured at 25 ° C. and 5 rpm using, for example, an E-type viscometer (“TVE22L” manufactured by Toki Sangyo Co., Ltd.).

The conductive material may be used as a conductive paste, a conductive film, or the like. The conductive paste may be an anisotropic conductive paste, and the conductive film may be an anisotropic conductive film. From the viewpoint of more efficiently arranging the solder particles on the electrodes, the conductive material is preferably a conductive paste. The conductive material is preferably used for electrical connection of electrodes. The conductive material is preferably a circuit connection material.

Hereinafter, each component contained in the conductive material will be described.

(Solder particles)
The conductive material contains a plurality of solder particles. Both the central portion and the outer surface of the solder particles are formed of solder. The solder particles are particles in which both the central portion and the outer surface are solder. When conductive particles having a base particle formed of a material other than solder and a solder portion arranged on the surface of the base particle are used instead of the solder particles, the conductivity is formed on the electrode. It becomes difficult for particles to collect. Further, in the above-mentioned conductive particles, since the solder bondability between the conductive particles is low, the conductive particles that have moved on the electrodes tend to move easily to the outside of the electrodes, and the effect of suppressing the displacement between the electrodes is also obtained. Tends to be low.

The solder is preferably a metal having a melting point of 450 ° C. or lower (low melting point metal). The solder particles are preferably metal particles having a melting point of 450 ° C. or lower (low melting point metal particles). The low melting point metal particles are particles containing a low melting point metal. The low melting point metal means a metal having a melting point of 450 ° C. or lower. The melting point of the low melting point metal is preferably 300 ° C. or lower, more preferably 160 ° C. or lower. The solder is preferably a low melting point solder having a melting point of less than 150 ° C.

The melting point of the solder particles is preferably 80 ° C. or higher, more preferably 100 ° C. or higher, preferably 300 ° C. or lower, and more preferably 160 ° C. or lower. When the melting point of the solder particles is equal to or higher than the lower limit and lower than the upper limit, the solder can be arranged more efficiently on the electrodes, and the insulation reliability and the conduction reliability can be further improved. it can.

The melting point of the solder particles can be determined by differential scanning calorimetry (DSC). Examples of the differential scanning calorimetry (DSC) device include "EXSTAR DSC7020" manufactured by SII.

Further, the solder particles preferably contain tin. The tin content in 100% by weight of the metal contained in the solder particles is preferably 30% by weight or more, more preferably 40% by weight or more, still more preferably 70% by weight or more, and particularly preferably 90% by weight or more. .. When the tin content in the solder particles is at least the above lower limit, the connection reliability between the solder portion and the electrode becomes even higher.

The tin content is measured using a high-frequency inductively coupled plasma emission spectroscopic analyzer (“ICP-AES” manufactured by Horiba, Ltd.) or a fluorescent X-ray analyzer (“EDX-800HS” manufactured by Shimadzu Corporation). can do.

By using the above solder particles, the solder melts and is bonded to the electrodes, and the solder portion conducts the electrodes. For example, the solder portion and the electrode are likely to come into surface contact rather than point contact, so that the connection resistance is low. Further, by using the solder particles, as a result of increasing the joint strength between the solder portion and the electrode, peeling between the solder portion and the electrode is more difficult to occur, and the continuity reliability and the connection reliability are further improved.

The metal constituting the solder particles is not particularly limited. The metal is preferably tin or an alloy containing tin. Examples of the alloy include tin-silver alloy, tin-copper alloy, tin-silver-copper alloy, tin-bismuth alloy, tin-zinc alloy, tin-indium alloy and the like. The low melting point metal is preferably tin, tin-silver alloy, tin-silver-copper alloy, tin-bismuth alloy, or tin-indium alloy because of its excellent wettability to the electrode. The low melting point metal is more preferably a tin-bismuth alloy or a tin-indium alloy.

The solder particles are preferably a filler material having a liquidus line of 450 ° C. or lower based on JIS Z3001: welding terminology. Examples of the composition of the solder particles include a metal composition containing zinc, gold, silver, lead, copper, tin, bismuth, indium and the like. A tin-indium type (117 ° C. eutectic) or a tin-bismuth type (139 ° C. eutectic), which has a low melting point and is lead-free, is preferable. That is, the solder particles preferably do not contain lead, and preferably contain tin and indium, or tin and bismuth.

In order to further increase the bonding strength between the solder part and the electrode, the solder particles are made of nickel, copper, antimony, aluminum, zinc, iron, gold, titanium, phosphorus, germanium, tellurium, cobalt, bismuth, manganese, chromium, etc. It may contain metals such as molybdenum and palladium. Further, from the viewpoint of further increasing the bonding strength between the solder portion and the electrode, the solder particles preferably contain nickel, copper, antimony, aluminum or zinc. From the viewpoint of further increasing the bonding strength between the solder portion and the electrode, the content of these metals for increasing the bonding strength is preferably 0.0001% by weight or more, based on 100% by weight of the metal contained in the solder particles. It is preferably 1% by weight or less.

The average particle size of the solder particles is preferably 2 μm or more, more preferably 5 μm or more, preferably 60 μm or less, and more preferably 35 μm or less. The average particle size of the solder particles is preferably 20 μm or less, and preferably 10 μm or less. When the average particle size of the solder particles is not less than the above lower limit and not more than the above upper limit, the solder can be arranged more efficiently on the electrodes, and the continuity reliability and the connection reliability are further improved. be able to. The average particle size of the solder particles is particularly preferably 2 μm or more and 10 μm or less. When the average particle size of the solder particles is 2 μm or more and 10 μm or less, the solder can be arranged more efficiently on the electrodes, and the conduction reliability and the connection reliability can be further improved. ..

The average particle size of the solder particles is more preferably a number average particle size. The average particle size of the solder particles can be determined by, for example, observing 50 arbitrary solder particles with an electron microscope or an optical microscope, calculating the average value of the particle size of each solder particle, or measuring the particle size distribution by laser diffraction. Required by doing. In observation with an electron microscope or an optical microscope, the particle size of each solder particle is determined as the particle size in a circle-equivalent diameter. In observation with an electron microscope or an optical microscope, the average particle diameter of any 50 solder particles in the circle equivalent diameter is substantially equal to the average particle diameter in the sphere equivalent diameter. In the laser diffraction type particle size distribution measurement, the particle size of each solder particle is obtained as the particle size in the equivalent diameter of a sphere. The average particle size of the solder particles is preferably calculated by laser diffraction type particle size distribution measurement.

The coefficient of variation (CV value) of the particle size of the solder particles is preferably 5% or more, more preferably 10% or more, preferably 40% or less, and more preferably 30% or less. When the coefficient of variation of the particle size of the solder particles is not less than the above lower limit and not more than the above upper limit, the solder can be arranged more efficiently on the electrode. However, the CV value of the particle size of the solder particles may be less than 5%.

The coefficient of variation (CV value) can be measured as follows.

CV value (%) = (ρ / Dn) × 100
ρ: Standard deviation of the particle size of the solder particles Dn: Mean value of the particle size of the solder particles

The shape of the solder particles is not particularly limited. The shape of the solder particles may be spherical, non-spherical, flat or the like.

The content of the solder particles in 100% by weight of the conductive material is preferably 45% by weight or more, more preferably 50% by weight or more, still more preferably 55% by weight or more, and particularly preferably 60% by weight or more. Is 85% by weight or less, more preferably 80% by weight or less, still more preferably 75% by weight or less. When the content of the solder particles is not less than the above lower limit and not more than the above upper limit, the solder can be arranged more efficiently on the electrodes, and it is easy to arrange a large amount of solder between the electrodes, and conduction is achieved. Reliability and insulation reliability can be enhanced even more effectively.

(Gap material)
The conductive material may include a gap material. The gap material is preferably a gap material for securing a gap between the two members at the time of conductive connection. The gap material preferably comes into contact with two members during conductive connection. At the time of conductive connection, the solder particles can be arranged in the space secured by the gap material so that one solder particle does not contact both of the two members. The shape of the gap material is preferably particles. The gap material is preferably gap particles.

The gap material is not particularly limited. Examples of the gap material include resin particles, inorganic particles excluding metal particles, organic-inorganic hybrid particles, and metal particles. The gap material may be solder particles. The material of the solder particles as the gap material may be the material described above. When the gap material is the above-mentioned solder particles, it is preferable that the solder particles and the solder particles used as the gap material have different average particle diameters. When the gap material is the above-mentioned solder particles, the average particle size of the solder particles is preferably smaller than the average particle size of the solder particles used as the gap material. When the gap material is the above-mentioned solder particles, it is preferable that the solder particles have a preferable configuration described in the above (solder particles) column, excluding the average particle size.

When the gap material is solder particles, the melting point of the solder particles as the gap material is preferably equal to or higher than the melting point of the solder particles that are not the gap material from the viewpoint of effectively exhibiting the function as the gap material. ..

When the gap material is not solder particles, the melting point of the gap material is preferably equal to or higher than the melting point of the solder particles, preferably exceeds the melting point of the solder particles, and may exceed the melting point of the solder particles by 10 ° C. or higher. preferable.

From the viewpoint of arranging the solder on the electrodes more efficiently and controlling the distance between the members with higher accuracy, the gap material is preferably resin particles or metal particles. The gap material may be core-shell particles comprising a core and a shell disposed on the surface of the core. The core may be an organic core, and the shell may be an inorganic shell.

Various organic substances are preferably used as the material for the resin particles. Examples of the material of the resin particles include polyolefin resins such as polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, polyisobutylene, and polybutadiene; acrylic resins such as polymethylmethacrylate and polymethylacrylate; polycarbonate, polyamide, and the like. Phenolic formaldehyde resin, melamine formaldehyde resin, benzoguanamine formaldehyde resin, urea formaldehyde resin, phenol resin, melamine resin, benzoguanamine resin, urea resin, epoxy resin, unsaturated polyester resin, saturated polyester resin, polyethylene terephthalate, polysulfone, polyphenylene oxide, polyacetal, Examples thereof include polyimide, polyamideimide, polyether ether ketone, polyether sulfone, divinylbenzene polymer, and divinylbenzene-based copolymer. Examples of the divinylbenzene-based copolymer and the like include a divinylbenzene-styrene copolymer and a divinylbenzene- (meth) acrylic acid ester copolymer. Since the hardness of the resin particles can be easily controlled within a suitable range, the material of the resin particles should be a polymer obtained by polymerizing one or more polymerizable monomers having an ethylenically unsaturated group. Is preferable.

When the resin particles are obtained by polymerizing a polymerizable monomer having an ethylenically unsaturated group, the polymerizable monomer having an ethylenically unsaturated group is a non-crosslinkable monomer. Examples thereof include crosslinkable monomers.

Examples of the non-crosslinkable monomer include styrene-based monomers such as styrene and α-methylstyrene; and carboxyl group-containing monomers such as (meth) acrylic acid, maleic acid, and maleic anhydride; Methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate, Alkyl (meth) acrylate compounds such as cyclohexyl (meth) acrylate and isobornyl (meth) acrylate; 2-hydroxyethyl (meth) acrylate, glycerol (meth) acrylate, polyoxyethylene (meth) acrylate, and glycidyl (meth) acrylate. Oxylate atom-containing (meth) acrylate compounds such as (meth) acrylonitrile and the like; nitrile-containing monomers such as (meth) acrylonitrile; vinyl ether compounds such as methyl vinyl ether, ethyl vinyl ether, and propyl vinyl ether; vinyl acetate, vinyl butyrate, vinyl laurate, and stearic acid. Acid vinyl ester compounds such as vinyl; unsaturated hydrocarbons such as ethylene, propylene, isoprene, and butadiene; trifluoromethyl (meth) acrylate, pentafluoroethyl (meth) acrylate, vinyl chloride, vinyl fluoride, chlorostyrene, etc. Halogen-containing monomers and the like can be mentioned.

Examples of the crosslinkable monomer include tetramethylolmethanetetra (meth) acrylate, tetramethylolmethanetri (meth) acrylate, tetramethylolmethanedi (meth) acrylate, trimethylolpropanetri (meth) acrylate, and dipenta. Elyslitholhexa (meth) acrylate, dipentaerythritol penta (meth) acrylate, glyceroltri (meth) acrylate, glyceroldi (meth) acrylate, (poly) ethylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) Polyfunctional (meth) acrylate compounds such as acrylates, (poly) tetramethylene glycol di (meth) acrylates, and 1,4-butanediol di (meth) acrylates; triallyl (iso) cyanurate, triallyltrimethylolate, divinylbenzene. , Dialylphthalate, diallylacrylamide, diallyl ether, and silane-containing monomers such as γ- (meth) acryloxypropyltrimethoxysilane, trimethoxysilylstyrene, and vinyltrimethoxysilane.

The term "(meth) acrylate" refers to acrylate and methacrylate. The term "(meth) acrylic" refers to acrylic and methacrylic. The term "(meth) acryloyl" refers to acryloyl and methacryloyl.

The resin particles can be obtained by polymerizing the polymerizable monomer having an ethylenically unsaturated group by a known method. Examples of this method include a method of suspension polymerization in the presence of a radical polymerization initiator, a method of swelling a monomer together with a radical polymerization initiator using non-crosslinked seed particles, and the like.

When the base material particles are inorganic particles other than metal or organic-inorganic hybrid particles, examples of the inorganic material for forming the base material particles include silica, alumina, barium titanate, zirconia, and carbon black. The inorganic substance is preferably not a metal. The particles formed of the silica are not particularly limited, but for example, after hydrolyzing a silicon compound having two or more hydrolyzable alkoxysilyl groups to form crosslinked polymer particles, firing is performed if necessary. Examples include particles obtained by doing so. Examples of the organic-inorganic hybrid particles include organic-inorganic hybrid particles formed of a crosslinked alkoxysilyl polymer and an acrylic resin.

The organic-inorganic hybrid particles are preferably core-shell type organic-inorganic hybrid particles having a core and a shell arranged on the surface of the core. It is preferable that the core is an organic core. It is preferable that the shell is an inorganic shell. From the viewpoint of effectively reducing the connection resistance between the electrodes, the base particle is preferably an organic-inorganic hybrid particle having an organic core and an inorganic shell arranged on the surface of the organic core.

Examples of the material for the organic core include the above-mentioned material for resin particles.

Examples of the material of the inorganic shell include the above-mentioned inorganic substances as the material of the base particle. The material of the inorganic shell is preferably silica. The inorganic shell is preferably formed by forming a metal alkoxide into a shell-like material by a sol-gel method on the surface of the core and then firing the shell-like material. The metal alkoxide is preferably a silane alkoxide. The inorganic shell is preferably formed of silane alkoxide.

When the base material particles are metal particles, examples of the metal that is the material of the metal particles include silver, copper, nickel, silicon, gold, tin, and titanium. Further, the metal particles may be the solder particles described above.

The ratio of the average diameter of the gap material to the average particle size of the solder particles (average diameter of the gap material / average particle size of the solder particles) is preferably 1.5 or more, more preferably 2 or more, still more preferably 2. It is 5.5 or more, particularly preferably 3 or more, and most preferably 7 or more. The above ratio (average diameter of the gap material / average particle diameter of the solder particles) is preferably 30 or less, more preferably 17.5 or less. When the ratio (average diameter of the gap material / average particle diameter of the solder particles) is equal to or greater than the above lower limit and equal to or less than the above upper limit, the spacing between the members can be controlled with even higher accuracy.

The average diameter of the gap material is preferably 2 μm or more, more preferably 5 μm or more, further preferably more than 5 μm, particularly preferably 10 μm or more, preferably 100 μm or less, more preferably 80 μm or less, still more preferably 60 μm or less. , Especially preferably 35 μm or less. The average diameter of the gap material may exceed 10 μm or 20 μm. The average diameter of the gap material is preferably larger than the average particle diameter of the solder particles described above. When the average diameter of the gap material is at least the above lower limit and at least the above upper limit, conduction reliability and connection reliability can be further effectively improved. The average diameter of the gap material is particularly preferably 10 μm or more and 35 μm or less. When the average diameter of the gap material is 10 μm or more and 35 μm or less, conduction reliability and connection reliability can be further effectively improved.

The average diameter of the gap material is more preferably a number average diameter. The average diameter of the gap material is obtained, for example, by observing 50 arbitrary gap materials with an electron microscope or an optical microscope and calculating the average value of the diameters of each gap material. The diameter of the gap material is preferably a dimension that maximizes the distance connecting two points on the outer circumference of the gap material with a straight line. When the gap material is particles, the average diameter of the gap material is the average particle size. When the gap material is a particle, the particle size of the gap material per piece is determined as the particle size in a circle-equivalent diameter in observation with an electron microscope or an optical microscope. In observation with an electron microscope or an optical microscope, the average particle diameter of any 50 gap materials in the circle equivalent diameter is substantially equal to the average particle diameter in the sphere equivalent diameter. In the laser diffraction type particle size distribution measurement, the particle size of each gap material is obtained as the particle size at the equivalent diameter of a sphere. When the gap material is a particle, the average particle size of the gap material is preferably calculated by laser diffraction type particle size distribution measurement.

The coefficient of variation (CV value) of the diameter of the gap material is preferably 5% or more, more preferably 10% or more, preferably 40% or less, and more preferably 30% or less. When the coefficient of variation of the particle size of the gap material is at least the above lower limit and at least the above upper limit, the spacing between the members can be controlled with even higher accuracy. However, the CV value of the particle size of the gap material may be less than 5%.

The coefficient of variation (CV value) can be measured as follows.

CV value (%) = (ρ / Dn) × 100
ρ: Standard deviation of the particle size of the gap material Dn: Mean value of the particle size of the gap material

The shape of the gap material is not particularly limited. The shape of the gap material may be spherical, non-spherical, flat or the like.

The content of the gap material in 100% by weight of the conductive material is preferably 0.1% by weight or more, more preferably 1% by weight or more, still more preferably 2% by weight or more, and preferably 20% by weight or less. More preferably, it is 10% by weight or less. When the content of the gap material is not less than the above lower limit and not more than the above upper limit, the continuity reliability and the insulation reliability can be further effectively improved. When the content of the gap material is at least the above lower limit and at least the above upper limit, the spacing between the members can be controlled with even higher accuracy.

(binder)
The conductive material contains a binder. The binder is not particularly limited. It is preferable to use a known insulating resin as the binder. The binder may contain a thermoplastic component (thermoplastic compound) or may contain a curable component. The binder preferably contains a curable component. Examples of the curable component include a photocurable component and a thermosetting component.

From the viewpoint of further effectively enhancing the insulation reliability between adjacent electrodes and further effectively enhancing the conduction reliability between the upper and lower electrodes to be connected, the binder contains a thermosetting component. It is preferable to contain it.

(Thermosetting component: Thermosetting compound)
The thermosetting component is not particularly limited. The thermosetting component preferably contains a thermosetting compound that can be cured by heating and a thermosetting agent. The thermosetting component may contain a curing accelerator. Examples of the thermosetting compound include oxetane compounds, epoxy compounds, episulfide compounds, (meth) acrylic compounds, phenol compounds, amino compounds, unsaturated polyester compounds, polyurethane compounds, silicone compounds and polyimide compounds. Epoxy compounds or episulfide compounds are preferable from the viewpoints of further improving the curability and viscosity of the conductive material, further effectively enhancing the conduction reliability, and further effectively enhancing the insulation reliability. Epoxy compounds are more preferred. The thermosetting component preferably contains an epoxy compound. The thermosetting component preferably contains an epoxy compound and a curing agent. Only one type of the thermosetting component may be used, or two or more types may be used in combination.

The epoxy compound is a compound having at least one epoxy group. Examples of the epoxy compound include bisphenol A type epoxy compound, bisphenol F type epoxy compound, bisphenol S type epoxy compound, phenol novolac type epoxy compound, biphenyl type epoxy compound, biphenyl novolac type epoxy compound, biphenol type epoxy compound, and naphthalene type epoxy compound. , Fluorene type epoxy compound, phenol aralkyl type epoxy compound, naphthol aralkyl type epoxy compound, dicyclopentadiene type epoxy compound, anthracene type epoxy compound, adamantan skeleton epoxy compound, tricyclodecane skeleton epoxy compound, naphthylene ether type Examples thereof include epoxy compounds and epoxy compounds having a triazine nucleus as a skeleton. Only one type of the epoxy compound may be used, or two or more types may be used in combination.

The epoxy compound is liquid or solid at room temperature (23 ° C.), and when the epoxy compound is solid at room temperature, the melting temperature of the epoxy compound is preferably equal to or lower than the melting point of the solder.

From the viewpoint of further improving the insulation reliability and the conduction reliability, the thermosetting compound preferably contains an epoxy compound.

From the viewpoint of more efficiently arranging the solder on the electrodes, the thermosetting compound preferably contains a thermosetting compound having a polyether skeleton.

Examples of the thermosetting compound having a polyether skeleton include a compound having a glycidyl ether group at both ends of an alkyl chain having 3 to 12 carbon atoms, and a polyether skeleton having 2 to 4 carbon atoms. Examples thereof include a polyether type epoxy compound having a structural unit in which 2 to 10 are continuously bonded.

From the viewpoint of further effectively enhancing the heat resistance of the cured product, the thermosetting compound preferably contains a thermosetting compound having an isocyanuric skeleton.

Examples of the thermosetting compound having an isocyanul skeleton include a triisocyanurate type epoxy compound, and the TEPIC series (TEPIC-G, TEPIC-S, TEPIC-SS, TEPIC-HP, TEPIC-L, manufactured by Nissan Chemical Industries, Ltd.). TEPIC-PAS, TEPIC-VL, TEPIC-UC) and the like.

The content of the thermosetting compound in 100% by weight of the conductive material is preferably 5% by weight or more, more preferably 10% by weight or more, still more preferably 15% by weight or more, and preferably 90% by weight or less. It is preferably 70% by weight or less, more preferably 50% by weight or less, and particularly preferably 30% by weight or less. When the content of the thermosetting compound is at least the above lower limit and at least the above upper limit, the conduction reliability between the electrodes can be further effectively enhanced. From the viewpoint of further effectively enhancing the impact resistance, it is preferable that the content of the thermosetting compound is large.

The content of the epoxy compound in 100% by weight of the conductive material is preferably 5% by weight or more, more preferably 10% by weight or more, still more preferably 15% by weight or more, preferably 90% by weight or less, more preferably 90% by weight or less. It is 70% by weight or less, more preferably 50% by weight or less, and particularly preferably 30% by weight or less. When the content of the epoxy compound is at least the above lower limit and at least the above upper limit, the conduction reliability between the electrodes can be further effectively enhanced. From the viewpoint of further enhancing the impact resistance, it is preferable that the content of the epoxy compound is large.

(Thermosetting component: Thermosetting agent)
The thermosetting agent is not particularly limited. The thermosetting agent heat-cures the thermosetting compound. Examples of the thermosetting agent include thiol curing agents such as imidazole curing agents, amine curing agents, phenol curing agents, and polythiol curing agents, acid anhydride curing agents, thermal cation initiators (thermal cation curing agents), and thermal radical generators. Can be mentioned. From the viewpoint of further improving the repair property, the thermosetting agent is preferably an acid anhydride curing agent. Only one type of the thermosetting agent may be used, or two or more types may be used in combination.

From the viewpoint of enabling the conductive material to be cured more quickly at a low temperature, the thermosetting agent is preferably an imidazole curing agent, a thiol curing agent, or an amine curing agent. Further, from the viewpoint of enhancing the storage stability when the thermosetting compound and the thermosetting agent are mixed, the thermosetting agent is preferably a latent curing agent. The latent curing agent is preferably a latent imidazole curing agent, a latent thiol curing agent or a latent amine curing agent. The thermosetting agent may be coated with a polymer substance such as a polyurethane resin or a polyester resin.

The imidazole curing agent is not particularly limited. Examples of the imidazole curing agent include 2-methylimidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-phenylimidazolium trimerite, and 2,4-diamino-6. -[2'-Methylimidazolyl- (1')]-ethyl-s-triazine and 2,4-diamino-6- [2'-methylimidazolyl- (1')]-ethyl-s-triazine isocyanuric acid adduct , 2-Phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2-phenyl-4-benzyl-5-hydroxymethylimidazole, 2-palatoryl-4-methyl-5 5-Position of 1H-imidazole in -hydroxymethylimidazole, 2-methitolyl-4-methyl-5-hydroxymethylimidazole, 2-metatruyl-4,5-dihydroxymethylimidazole, 2-palatoryl-4,5-dihydroxymethylimidazole, etc. Examples thereof include an imidazole compound in which the hydrogen in the above is substituted with a hydroxymethyl group and the hydrogen at the 2-position is substituted with a phenyl group or a toluyl group.

The thiol curing agent is not particularly limited. Examples of the thiol curing agent include trimethylolpropane tris-3-mercaptopropionate, pentaerythritol tetrakis-3-mercaptopropionate, and dipentaerythritol hexa-3-mercaptopropionate.

The amine curing agent is not particularly limited. Examples of the amine curing agent include hexamethylenediamine, octamethylenediamine, decamethylenediamine, 3,9-bis (3-aminopropyl) -2,4,8,10-tetraspiro [5.5] undecane, and bis (4). -Aminocyclohexyl) methane, metaphenylenediamine, diaminodiphenylsulfone and the like.

The acid anhydride curing agent is not particularly limited, and any acid anhydride used as a curing agent for a thermosetting compound such as an epoxy compound can be widely used. Examples of the acid anhydride curing agent include phthalic anhydride, tetrahydrophthalic anhydride, trialkyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, and methylbutenyltetrahydrophthalic anhydride. Bifunctional such as phthalic acid derivative anhydride, maleic anhydride, nadic acid anhydride, methylnadic anhydride, glutaric anhydride, succinic anhydride, glycerinbis trimellitic anhydride monoacetate, and ethylene glycolbis trimellitic anhydride. Acid anhydride curing agent, trifunctional acid anhydride curing agent such as trimellitic anhydride, and pyromellitic anhydride, benzophenonetetracarboxylic acid anhydride, methylcyclohexenetetracarboxylic acid anhydride, polyazelineic acid anhydride, etc. Examples thereof include an acid anhydride curing agent having four or more functions.

The thermal cation initiator is not particularly limited. Examples of the thermal cation initiator include an iodonium-based cation curing agent, an oxonium-based cation curing agent, and a sulfonium-based cation curing agent. Examples of the iodonium-based cationic curing agent include bis (4-tert-butylphenyl) iodonium hexafluorophosphate and the like. Examples of the oxonium-based cationic curing agent include trimethyloxonium tetrafluoroborate. Examples of the sulfonium-based cationic curing agent include try-p-tolylsulfonium hexafluorophosphate.

The thermal radical generator is not particularly limited. Examples of the thermal radical generator include azo compounds and organic peroxides. Examples of the azo compound include azobisisobutyronitrile (AIBN) and the like. Examples of the organic peroxide include di-tert-butyl peroxide and methyl ethyl ketone peroxide.

The content of the thermosetting agent is not particularly limited. With respect to 100 parts by weight of the thermosetting compound, the content of the thermosetting agent is preferably 0.01 parts by weight or more, more preferably 1 part by weight or more, preferably 200 parts by weight or less, more preferably. It is 100 parts by weight or less, more preferably 75 parts by weight or less. When the content of the thermosetting agent is at least the above lower limit, it is easy to sufficiently cure the conductive material. When the content of the thermosetting agent is not more than the above upper limit, it becomes difficult for excess thermosetting agent that was not involved in curing to remain after curing, and the heat resistance of the cured product becomes even higher.

(Thermosetting component: Curing accelerator)
The conductive material may contain a curing accelerator. The curing accelerator is not particularly limited. The curing accelerator preferably acts as a curing catalyst in the reaction between the thermosetting compound and the thermosetting agent. The curing accelerator preferably acts as a curing catalyst in the reaction with the thermosetting compound. Only one type of the curing accelerator may be used, or two or more types may be used in combination.

Examples of the curing accelerator include phosphonium salt, tertiary amine, tertiary amine salt, quaternary onium salt, tertiary phosphine, crown ether complex, phosphonium ylide and the like. Specifically, the curing accelerator includes an imidazole compound, an isocyanurate of an imidazole compound, dicyandiamide, a derivative of dicyandiamide, a melamine compound, a derivative of a melamine compound, diaminomaleonitrile, diethylenetriamine, triethylenetetramine, and tetraethylenepentamine. , Amine compounds such as bis (hexamethylene) triamine, triethanolamine, diaminodiphenylmethane, organic acid dihydrazide, 1,8-diazabicyclo [5,4,0] undecene-7, 3,9-bis (3-aminopropyl) Examples thereof include −2,4,8,10-tetraoxaspiro [5,5] undecane, boron trifluoride, and organic phosphorus compounds such as triphenylphosphine, tricyclohexylphosphine, tributylphosphine and methyldiphenylphosphine.

The phosphonium salt is not particularly limited. Examples of the phosphonium salt include tetranormal butyl phosphonium bromide, tetranormal butyl phosphonium O, O-diethyl dithiophosphate, methyl tributyl phosphonium dimethyl phosphate, tetranormal butyl phosphonium benzotriazole, tetranormal butyl phosphonium tetrafluoroborate, and tetranormal. Butylphosphonium tetraphenylborate and the like can be mentioned.

The content of the curing accelerator is appropriately selected so that the thermosetting compound can be cured well. The content of the curing accelerator with respect to 100 parts by weight of the thermosetting compound is preferably 0.5 parts by weight or more, more preferably 0.8 parts by weight or more, preferably 10 parts by weight or less, more preferably 8 parts by weight. It is less than a part by weight. When the content of the curing accelerator is not less than the above lower limit and not more than the above upper limit, the thermosetting compound can be cured satisfactorily.

(flux)
The conductive material may contain a flux. By using the flux, the conduction reliability between the electrodes can be further effectively enhanced. The above flux is not particularly limited. As the flux, a flux generally used for solder bonding or the like can be used.

The flux includes zinc chloride, a mixture of zinc chloride and an inorganic halide, a mixture of zinc chloride and an inorganic acid, a molten salt, phosphoric acid, a derivative of phosphoric acid, an organic halide, hydrazine, an amine compound, an organic acid and the like. Examples include pine fat. Only one type of the above flux may be used, or two or more types may be used in combination.

Examples of the molten salt include ammonium chloride and the like. Examples of the organic acid include lactic acid, citric acid, stearic acid, glutamic acid and glutaric acid. Examples of the pine fat include activated pine fat and non-activated pine fat. The flux is preferably an organic acid having two or more carboxyl groups or pine fat. The flux may be an organic acid having two or more carboxyl groups, or may be pine fat. By using an organic acid having two or more carboxyl groups or pine fat, the conduction reliability between the electrodes is further increased.

Examples of the organic acid having two or more carboxyl groups include succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, and sebacic acid.

Examples of the amine compound include cyclohexylamine, dicyclohexylamine, benzylamine, benzhydrylamine, imidazole, benzimidazole, phenylimidazole, carboxybenzoimidazole, benzotriazole, and carboxybenzotriazole.

The pine fat is a rosin containing abietic acid as a main component. Examples of the rosins include abietic acid and acrylic-modified rosins. The flux is preferably rosins, more preferably abietic acid. By using this preferable flux, the conduction reliability between the electrodes is further increased.

The active temperature (melting point) of the flux is preferably 50 ° C. or higher, more preferably 70 ° C. or higher, still more preferably 80 ° C. or higher, preferably 200 ° C. or lower, more preferably 190 ° C. or lower, still more preferably 160 ° C. or higher. ° C. or lower, more preferably 150 ° C. or lower, even more preferably 140 ° C. or lower. When the active temperature of the flux is equal to or higher than the lower limit and lower than the upper limit, the flux effect is more effectively exhibited. The active temperature (melting point) of the flux is preferably 80 ° C. or higher and 190 ° C. or lower. The active temperature (melting point) of the flux is particularly preferably 80 ° C. or higher and 140 ° C. or lower.

The active temperature (melting point) of the flux is 80 ° C. or higher and 190 ° C. or lower. Examples of the flux include succinic acid (melting point 186 ° C.), glutaric acid (melting point 96 ° C.), adipic acid (melting point 152 ° C.), and pimelic acid (melting point 104 ° C.). ℃), and dicarboxylic acids such as pimelic acid (melting point 142 ° C.), benzoic acid (melting point 122 ° C.), and malic acid (melting point 130 ° C.).

The boiling point of the flux is preferably 200 ° C. or lower.

The flux may be dispersed in the conductive material or may be adhered to the surface of the solder particles.

From the viewpoint of further improving the insulation reliability and the conduction reliability, the flux is preferably a salt of an acid compound and a base compound.

The acid compound is preferably an organic compound having a carboxyl group. Examples of the acid compound include malonic acid, succinic acid, glutaric acid, adipic acid, pimelli acid, suberic acid, azelaic acid, sebacic acid, citric acid, malic acid, and cyclic aliphatic carboxylic acid, which are aliphatic carboxylic acids. Examples thereof include cyclohexylcarboxylic acid, 1,4-cyclohexyldicarboxylic acid, isophthalic acid which is an aromatic carboxylic acid, terephthalic acid, trimellitic acid, ethylenediamine tetraacetic acid and the like. From the viewpoint of further improving the insulation reliability and the conduction reliability, the acid compound is preferably glutaric acid, cyclohexylcarboxylic acid, or adipic acid.

The basic compound is preferably an organic compound having an amino group. Examples of the basic compound include diethanolamine, triethanolamine, methyldiethanolamine, ethyldiethanolamine, cyclohexylamine, dicyclohexylamine, benzylamine, benzhydrylamine, 2-methylbenzylamine, 3-methylbenzylamine, and 4-tert-butylbenzylamine. , N-Methylbenzylamine, N-ethylbenzylamine, N-phenylbenzylamine, N-tert-butylbenzylamine, N-isopropylbenzylamine, N, N-dimethylbenzylamine, imidazole compounds, and triazole compounds. .. From the viewpoint of further improving the insulation reliability and the conduction reliability, the basic compound is preferably benzylamine.

The content of the flux in 100% by weight of the conductive material is preferably 0.5% by weight or more, preferably 30% by weight or less, and more preferably 25% by weight or less. The conductive material does not have to contain flux. When the content of the flux is not less than the above lower limit and not more than the above upper limit, it becomes more difficult to form an oxide film on the surface of the solder and the electrode, and further, the oxide film formed on the surface of the solder and the electrode is further formed. Can be effectively removed.

(Filler)
The conductive material according to the present invention may contain a filler. The filler may be an organic filler or an inorganic filler.

The conductive material preferably does not contain the filler, or contains the filler in an amount of 5% by weight or less.

The content of the filler in 100% by weight of the conductive material is preferably 0% by weight (not contained) or more, preferably 5% by weight or less, more preferably 2% by weight or less, still more preferably 1% by weight or less. is there. When the content of the filler is not less than the above lower limit and not more than the above upper limit, the insulation reliability can be further effectively enhanced, and the conduction reliability can be further effectively enhanced.

(Other ingredients)
The conductive material may be, for example, a filler, a bulking agent, a softening agent, a plasticizer, a thixo agent, a leveling agent, a polymerization catalyst, a curing catalyst, a colorant, an antioxidant, a heat stabilizer, a light stabilizer, if necessary. , UV absorbers, lubricants, antistatic agents, flame retardants and other various additives may be included.

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

Thermosetting component (thermosetting compound):
Thermosetting compound 1: Bisphenol F type epoxy compound, "YDF-8170C" manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.
Thermosetting compound 2: Bisphenol A type epoxy compound, "YD-8125" manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.
Thermosetting compound 3: Phenolic novolac type epoxy compound, "DEN431" manufactured by DOWN
Thermosetting compound 4: Aliphatic epoxy compound, "Epolite 1600" manufactured by Kyoeisha Chemical Co., Ltd.
Thermosetting compound 5: Epoxy compound containing isocyanuric skeleton, "TEPIC-SP" manufactured by Nissan Chemical Industries, Ltd.

Thermosetting component (thermosetting agent):
Thermosetting agent 1: Acid anhydride curing agent, "Recasid MH" manufactured by New Japan Chemical Co., Ltd.
Thermosetting agent 2: Acid anhydride curing agent, "Recasid TH" manufactured by New Japan Chemical Co., Ltd.

Thermosetting component (curing accelerator):
Curing accelerator 1: Organophosphorus salt, "PX-4MP" manufactured by Nippon Chemical Industrial Co., Ltd.
Curing Accelerator 2: 2,4-Diamino-6- [2-Ethyl-4-methylimidazolyl- (1)]-Ethyl-s-Triazine, "2E4MZ-A" manufactured by Shikoku Chemicals Corporation

flux:
Flux 1: "Benzylamine glutaric salt", melting point 108 ° C
Method for producing flux 1:
In a glass bottle, 24 g of water as a reaction solvent and 13.212 g of glutaric acid (manufactured by Wako Pure Chemical Industries, Ltd.) were put and dissolved at room temperature until uniform. Then, 10.715 g of benzylamine (manufactured by Wako Pure Chemical Industries, Ltd.) was added and stirred for about 5 minutes to obtain a mixed solution. The obtained mixture was placed in a refrigerator at 5 to 10 ° C. and left overnight. The precipitated crystals were separated by filtration, washed with water and vacuum dried to obtain flux 1.

Solder particles:
Solder particles 1: SnBi solder particles, melting point 138 ° C, solder particles selected from "Sn42Bi58" manufactured by Mitsui Mining & Smelting Co., Ltd., average particle size: 30 μm
Solder particles 2: SnAgCu solder particles, "SnAg3Cu0.5" manufactured by Mitsui Mining & Smelting Co., Ltd., average particle size: 30 μm, melting point: 217 ° C.

Gap material:
Gap material 1: Divinylbenzene copolymer resin particles, "Micropearl GS-275" manufactured by Sekisui Chemical Co., Ltd., average particle size: 75 μm
Gap material 2: Divinylbenzene copolymer resin particles, "Micropearl GS-270" manufactured by Sekisui Chemical Co., Ltd., average particle size: 70 μm
Gap material 3: Divinylbenzene copolymer resin particles, "Micropearl GS-260" manufactured by Sekisui Chemical Co., Ltd., average particle size: 60 μm
Gap material 4: Divinylbenzene copolymer resin particles, "Micropearl GS-255" manufactured by Sekisui Chemical Co., Ltd., average particle size: 55 μm
Gap material 5: Divinylbenzene copolymer resin particles, "Micropearl GS-250" manufactured by Sekisui Chemical Co., Ltd., average particle size: 50 μm
Gap material 6: Divinylbenzene copolymer resin particles, "Micropearl GS-245" manufactured by Sekisui Chemical Co., Ltd., average particle size: 45 μm
Gap material 7: Divinylbenzene copolymer resin particles, "Micropearl GS-240" manufactured by Sekisui Chemical Co., Ltd., average particle size: 40 μm

(Examples 1 to 11 and Comparative Examples 1 to 3)
(1) Preparation of Conductive Material A conductive material was obtained by blending the components shown in Tables 1 and 2 below in the blending amounts shown in Tables 1 and 2 below.

(2) Preparation of First Connection Structure As a second connection target member, 500 μm copper electrodes (second electrodes) are arranged at a 700 μm pitch on the surface of a semiconductor chip body (size 10 mm × 10 mm, thickness 1 mm). I prepared a semiconductor chip that has been used.

As the first connection target member, copper is formed on the surface of the glass epoxy substrate body (size 52 mm × 52 mm, thickness 1 mm, material FR-4) so as to have the same pattern as the electrodes of the second connection target member. A glass epoxy substrate on which an electrode (first electrode) is arranged was prepared.

On the surface of the first electrode, the conductive material immediately after production has a thickness 1.5 times that of the gap material (Examples 1 to 11 and Comparative Examples 1 and 2), or 100 μm (Comparative Example 3). The conductive material layer was formed (first arrangement step). Next, a flexible printed circuit board was laminated on the upper surface of the conductive material layer so that the electrodes face each other (second arrangement step). The weight of the flexible printed circuit board is added to the conductive material layer. From that state, the temperature of the conductive material layer was heated so as to reach the melting point of the solder 5 seconds after the start of temperature rise. Further, 15 seconds after the start of temperature rise, the conductive material layer was heated to a temperature of 160 ° C. to cure the conductive material layer to obtain a connection structure (connection step). No pressurization was performed during heating.

(Examples 12 to 22, Comparative Examples 4 and 23, 24)
(1) Preparation of Conductive Material A conductive material was obtained by blending the components shown in Tables 3 and 4 below in the blending amounts shown in Tables 3 and 4 below.

(2) Preparation of Second Connection Structure As a second connection target member, 400 μm copper electrodes (second electrodes) are arranged at an 800 μm pitch on the surface of a semiconductor chip body (size 10 mm × 10 mm, thickness 1 mm). I prepared a semiconductor chip that has been used.

As the first connection target member, copper is formed on the surface of the glass epoxy substrate body (size 52 mm × 52 mm, thickness 1 mm, material FR-4) so as to have the same pattern as the electrodes of the second connection target member. A glass epoxy substrate on which an electrode (first electrode) is arranged was prepared.

On the surface of the first electrode, the conductive material immediately after production has a thickness 1.5 times that of the gap material (Examples 12 to 22, Comparative Examples 4 and 23), or 100 μm (Example 24). ) To form a conductive material layer (first arrangement step). Next, a flexible printed circuit board was laminated on the upper surface of the conductive material layer so that the electrodes face each other (second arrangement step). The weight of the flexible printed circuit board is added to the conductive material layer. From that state, the temperature of the conductive material layer was heated so as to reach the melting point of the solder 5 seconds after the start of temperature rise. Further, 15 seconds after the start of temperature rise, the conductive material layer was heated to a temperature of 160 ° C. to cure the conductive material layer to obtain a connection structure (connection step). No pressurization was performed during heating.

(Evaluation)
(1) Relationship between the width of the cured product and the distance between the first adjacent electrodes and the distance between the second adjacent electrodes With respect to the obtained first connection structure and the second connection structure, the first The width of the cured product was measured by observing the cross section of the electrode, the connecting portion, and the second electrode in the stacking direction with a scanning electron microscope. The width of the cured product was calculated as an average value at 10 locations. Further, the cross section of the obtained first connection structure and the second connection structure shall be observed with a scanning electron microscope in the cross section of the first electrode, the connection portion and the second electrode in the stacking direction. The distance between the first adjacent electrodes and the distance between the second adjacent electrodes were measured. The distance between the first adjacent electrodes and the distance between the second adjacent electrodes were calculated as an average value of 10 locations.

With respect to the obtained first connection structure and the second connection structure, the width of the cured product is L μm and the width of the cured product is L μm in the cross section in the stacking direction of the first electrode, the connection portion and the second electrode. When the distance between the electrodes was La μm and the distance between the second adjacent electrodes was Lb μm, it was confirmed whether or not the following equations (1) and (2) were satisfied. The relationship between the width of the cured product and the distance between the adjacent first electrodes and the distance between the adjacent second electrodes was determined according to the following criteria.

10 ≦ L <La / 2 equation (1)
10 ≦ L <Lb / 2 equation (2)

[Criteria for determining the relationship between the width of the cured product and the distance between the first adjacent electrodes and the distance between the second adjacent electrodes]
○○: The connection structure satisfies the above equations (1) and (2), and the connection structure satisfies the following equations (3) and (4). ○: The connection structure satisfies the above equations (1) and (1) and Satisfying (2) and the connecting structure satisfies the following formulas (5) and (6) ×: The connecting structure does not satisfy the above formula (1) or (2), and L <10 XX: The connection structure does not satisfy the above formula (1) or (2), and La / 2 ≦ L or Lb / 2 ≦ L.

La / 4 ≤ L <La / 2 equation (3)
Lb / 4 ≤ L <Lb / 2 equation (4)
10 <L <La / 4 formula (5)
10 <L <Lb / 4 equation (6)

(2) Solder flash In the obtained connection structure, it was confirmed whether or not the solder flash was generated by observing the connection portions (300 points) with a scanning electron microscope. The solder flash was judged according to the following criteria.

[Criteria for solder flash]
○: Solder flash has not occurred ×: Solder flash has occurred

The results are shown in Tables 1 to 4 below.

1,1X ... Connection structure 2 ... First connection target member 2a ... First electrode 3 ... Second connection target member 3a ... Second electrode 4,4X ... Connection part 4A, 4XA ... Solder part 4B, 4XB … Cured material part 11… Conductive material 11A… Solder particles 11B… Thermosetting component

Claims (5)

A first connection target member having a plurality of first electrodes on the upper surface,
A second connection target member having a plurality of second electrodes on the lower surface,
The first connection target member and the connection portion connecting the second connection target member are provided.
The first electrode and the second electrode face each other via the connection portion.
The connection portion has a solder portion and a cured product portion.
Between the upper surface of the first electrode and the lower surface of the second electrode so that the solder portion in the connecting portion electrically connects the first electrode and the second electrode. Have been placed and
The cured product portion in the connecting portion is arranged on the side surface of the solder portion.
In the cross section of the first electrode, the connection portion, and the second electrode in the stacking direction, when the width of the cured product portion is Lμm and the distance between the adjacent first electrodes is Laμm, the following formula is used. A connection structure that satisfies (1).
10 ≦ L <La / 2 equation (1) In the cross section of the first electrode, the connection portion, and the second electrode in the stacking direction, when the width of the cured product portion is Lμm and the distance between the adjacent second electrodes is Lbμm, the following formula is used. The connection structure according to claim 1, which satisfies (2).
10 ≦ L <Lb / 2 equation (2) A first arrangement step of arranging the conductive material on the surface of a first connection target member having a plurality of first electrodes on the upper surface using a conductive material containing a plurality of solder particles and a binder.
The first electrode and the second electrode have a second connection target member having a plurality of second electrodes on the lower surface on the surface of the conductive material opposite to the first connection target member side. The second arrangement step of arranging so as to face each other and
By heating the conductive material to a temperature equal to or higher than the melting point of the solder particles, a connection portion is formed in which the connection portion connecting the first connection target member and the second connection target member is formed by the conductive material. With process
The connection portion has a solder portion and a cured product portion.
Between the upper surface of the first electrode and the lower surface of the second electrode so that the solder portion in the connecting portion electrically connects the first electrode and the second electrode. Have been placed and
The cured product portion in the connecting portion is arranged on the side surface of the solder portion.
In the cross section of the first electrode, the connection portion, and the second electrode in the stacking direction, when the width of the cured product portion is Lμm and the distance between the adjacent first electrodes is Laμm, the following formula is used. A method for manufacturing a connection structure that satisfies (3).
10 ≦ L <La / 2 equation (3) In the cross section of the first electrode, the connection portion, and the second electrode in the stacking direction, when the width of the cured product portion is Lμm and the distance between the adjacent second electrodes is Lbμm, the following formula is used. The method for manufacturing a connection structure according to claim 3, which satisfies (4).
10 ≦ L <Lb / 2 equation (4) The method for manufacturing a connection structure according to claim 3 or 4, wherein in the first arrangement step, the conductive material is arranged only on the surface of the first electrode.

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