JP4648294B2 - Electrode bonding method and electrode bonding structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrode connection method and electrode connection structure that controls generation of short circuit failure as well as the occurrence of migration failures. <P>SOLUTION: The electrode connection method is to dispose a first insulating adhesive resin 6, in which insulating particles are dispersed, at an edge of a facing area between a first circuit organizer having multiple first electrodes 4A and a second circuit organizer having multiple second electrodes 5A formed such that they face the multiple first electrodes of the first circuit organizer, dispose a second insulating adhesive resin 2, in which conductive particles are dispersed, inside the edge part of the facing area, and to pressurize and heat the first and second insulating adhesive resins through the first or second circuit organizer, thereby electrically connecting the respective first electrodes 4A of the first circuit organizer and the respective second electrodes 5A of the second circuit organizer facing them through the conductive particles, and intermingling the conductive and insulating particles in a close-by region of the edge of the facing area. <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

  The present invention relates to an electrode bonding method and an electrode bonding structure in which an electrode of another circuit forming body is bonded to an electrode of a circuit forming body using an insulating adhesive resin in which conductive particles are dispersed.

  Conventionally, conductive particles have been dispersed as a technique for electrically bonding an electrode of a circuit forming body such as another glass substrate or flexible substrate or an electronic component to an electrode of a circuit forming body such as a glass substrate or a flexible substrate. A technique using an insulating adhesive resin such as an anisotropic conductive sheet is known. This technique arranges an anisotropic conductive sheet between electrodes to be joined, and pressurizes and heats the anisotropic conductive sheet with a crimping tool through a circuit forming body, thereby the insulating adhesive resin. Is a technique in which the electrodes are melted and the electrodes are electrically connected through the conductive particles.

  This electrode bonding technique using an anisotropic conductive sheet can be applied to various types of electrode bonding, for example, electrode bonding (FOG) between a glass substrate and a flexible substrate, and an electrode between a glass substrate and an IC chip component. Bonding (COG), electrode bonding (COF) between flexible substrate and IC chip component, electrode bonding between printed wiring substrate and IC chip component, electrode bonding between flexible substrate and flexible substrate, electrode between flexible substrate and printed wiring substrate Widely used for bonding, etc.

  In recent years, for example, in flat panel bonding technology represented by electrode bonding between a glass substrate and a flexible substrate, along with ensuring the reliability when a high voltage is applied between the electrodes, along with the increase in the density of electronic devices There is a demand for further narrowing (miniaturization) between adjacent wiring electrodes. Specifically, the pitch between adjacent wiring electrodes is required to be narrowed from 200 μm to 100 μm, which has been conventionally required, to 100 μm to 50 μm or less. Similarly, in the technology for bonding IC chip components in a face-down manner, such as electrode bonding between a glass substrate and an IC chip component, or electrode bonding between a flexible substrate and an IC chip component, bumps are also developed along with the increase in functionality. There is a demand for further narrowing (miniaturization) between electrodes. Specifically, the pitch between the adjacent wiring electrodes is required to be narrowed from 120 μm to 80 μm, which has been conventionally required, to 80 μm to 40 μm or less.

  When the pitch between adjacent wiring electrodes is reduced to the above level, in the electrode joining technique using the anisotropic conductive sheet, there is a high possibility that defects such as a short circuit failure and a migration failure occur.

As shown in FIG. 11A, the short circuit failure is caused by the anisotropic conductive sheet 101, for example, the glass substrate 104 having the first electrode 104A and the second electrode formed so as to face the first electrode 104A. As shown in FIG. 11B, the insulating adhesive of the anisotropic conductive sheet 101 is pressed and heated by the crimping tool 106 in a state where it is disposed in the region 100X facing the flexible substrate 105 having 105A. This occurs when the resin 102 melts and flows into the vicinity region 100Y of the edge of the opposing region 100X, and the conductive particles 103 of the anisotropic conductive sheet 101 flow and aggregate in the vicinity region 100Y along with this flow. Is.
When the pitch between the adjacent wiring electrodes 100P (see FIG. 11C) is reduced (for example, 100 μm to 50 μm or less), the amount of conductive particles 103 that do not participate in electrode bonding between the adjacent electrodes decreases. More conductive particles 103 are pushed out to the neighboring region 100Y and agglomerate in the neighboring region 100Y, so that a short circuit is likely to occur.

  On the other hand, the migration failure is caused by the insulating adhesive resin being in contact with the glass substrate 104 and the flexible substrate 105 due to the flow rate of the insulating adhesive resin 102 being too fast or too slow when being pressed and heated by the crimping tool 106. This is caused by insufficient adhesion to 102 or voids generated in the insulating adhesive resin 102. When the pitch between the adjacent wiring electrodes 100P becomes a narrow pitch, the amount of the insulating adhesive resin 102 that can be accumulated in the adjacent wiring electrodes 100P decreases, and the insulating adhesive resin 102 flows while being compressed, The flow of the insulating adhesive resin 102 is accelerated, resulting in an insufficiently pressurized portion, which tends to cause a migration failure.

As techniques for solving the short circuit defect, for example, techniques disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 06-349339) and Patent Document 2 (Japanese Patent Laid-Open No. 05-013119) are known. The technique of Patent Document 1 prevents short-circuit defects by further dispersing insulating particles in an anisotropic conductive sheet in which conductive particles are dispersed in an insulating adhesive resin. Moreover, the technique of patent document 2 prevents a short circuit defect by forming the insulating layer which disperse | distributed insulating particle | grains on the anisotropic conductive sheet.
Japanese Patent Laid-Open No. 06-349339 JP 05-013119 A

  However, in the techniques of Patent Document 1 and Patent Document 2, in addition to the conductive particles, insulating particles are further present in the insulating adhesive resin, so that the particle density is increased. Thereby, the fluidity | liquidity of insulating adhesive resin worsens and there exists a problem that the adhesiveness of a circuit formation body and insulating adhesive resin falls. In addition, the insulating particles may interfere with the contact between the conductive particles and the electrodes of the circuit forming body, and the necessary conduction may not be ensured.

  Accordingly, an object of the present invention is to solve the above-described problem, and join an electrode of another circuit forming body to an electrode of the circuit forming body using an insulating adhesive resin in which conductive particles are dispersed. An object of the present invention is to provide an electrode bonding method and an electrode bonding structure that suppress the occurrence of short-circuit defects and the occurrence of migration defects in electrode bonding.

In order to achieve the above object, the present invention is configured as follows.
According to the first aspect of the present invention, the end portions of the glass substrate having a plurality of first electrodes and the plurality of second electrodes formed to face the plurality of first electrodes of the glass substrate, respectively. The first insulating adhesive resin in which the insulating particles are dispersed is arranged on both edges of the facing area with the end of the flexible substrate having electrodes, and inside the both edges of the facing area, Arranging a second insulating adhesive resin in which conductive particles are dispersed;
The first and second insulating adhesive resins are pressurized and heated through the glass substrate or the flexible substrate, and the first electrode of the glass substrate and the flexible substrate facing the first electrode are the same. Electrode bonding in which each of the second electrodes is electrically bonded through the conductive particles, and the conductive particles and the insulating particles are mixed in a region in the vicinity of the both edges of the facing region. A method,
The first insulating adhesive resin disposed at the edge portion on the end side of the glass substrate in the facing region is the first insulating resin disposed on the edge portion on the end portion side of the flexible substrate in the facing region. The insulating adhesive resin is formed wider than the insulating adhesive resin in the direction connecting the both edges, and after the first and second insulating adhesive resins are heated under pressure , Provided is an electrode bonding method in which only a region near an edge is covered with an insulating sealing resin.
In the present invention, the vicinity region includes a region adjacent outside the outer periphery of the edge of the facing region. That is, the vicinity region includes a region that is not sandwiched between the first circuit formation body and the second circuit formation body in the thickness direction of the first or second circuit formation body. Furthermore, in other words, the neighboring region has the first and second insulating adhesions when heated under pressure with the first and second insulating adhesive resins sandwiched between the glass substrate and the flexible substrate. The area | region which agent resin protruded from between the 1st circuit formation body and the 2nd circuit formation body is included.

According to the second aspect of the present invention, the first and second insulating adhesive resins are thermosetting resins,
The electrode joining method according to the first aspect, wherein the melting temperature of the first insulating adhesive resin is lower than the melting temperature of the second insulating adhesive resin.

According to the third aspect of the present invention, the first and second insulating adhesive resins are thermosetting resins,
When the first and second insulating adhesive resins are heated under pressure, after the first insulating adhesive resin begins to melt, the second insulating adhesive resin begins to melt, and then The electrode joining method according to the first aspect, wherein the second insulating adhesive resin starts to harden after the first insulating adhesive resin starts to harden, is provided.
Here, “melting” includes a process in which the insulating adhesive resin is softened.

According to the fourth aspect of the present invention, when the second insulating adhesive resin starts to cure, the melt viscosity of the first insulating adhesive resin is equal to the melting temperature of the second insulating adhesive resin. The electrode joining method according to the third aspect, which is higher than the viscosity, is provided.
Here, the “melt viscosity” refers to the viscosity in a softened state of the insulating adhesive resin heated under pressure.

  According to a fifth aspect of the present invention, any one of the first to fourth aspects, wherein the thermal conductivity of the first insulating adhesive resin is lower than the thermal conductivity of the second insulating adhesive resin. An electrode joining method as described in one is provided.

  According to the sixth aspect of the present invention, any one of the first to fifth aspects, wherein the average particle size of the insulating particles is the same or smaller than the average particle size of the conductive particles. An electrode joining method as described in one is provided.

  According to the seventh aspect of the present invention, the volume density of the insulating particles in the first insulating adhesive resin is larger than the volume density of the conductive particles in the second insulating adhesive resin. The electrode joining method according to any one of the first to sixth aspects, which is the same or less, is provided.

  According to an eighth aspect of the present invention, in any one of the first to seventh aspects, the second insulating adhesive resin in which the conductive particles are dispersed is an anisotropic conductive sheet. An electrode joining method is provided.

According to the ninth aspect of the present invention, a glass substrate having a plurality of first electrodes;
A flexible substrate having a plurality of second electrodes disposed respectively facing the plurality of first electrodes of the glass substrate;
A first insulating adhesive resin in which insulating particles that are disposed at both ends of an opposing region between the end of the glass substrate and the end of the flexible substrate and in which both are bonded are dispersed;
A second insulating adhesive resin in which conductive particles are dispersed, disposed on the inner side of the both edges of the opposing region;
An electrode joint structure comprising:
The first insulating adhesive resin disposed at the edge portion on the end side of the glass substrate in the facing region is the first insulating resin disposed on the edge portion on the end portion side of the flexible substrate in the facing region. From the insulating adhesive resin, is formed in a wider direction in the direction connecting the both ends,
Provided is an electrode bonding structure further comprising an insulating sealing resin that covers only a region in the vicinity of an edge portion on the end side of the glass substrate.

According to a tenth aspect of the present invention, in the electrode junction according to the ninth aspect, the average particle diameter of the insulating particles is the same or smaller than the average particle diameter of the conductive particles. Provide a structure.

According to the electrode bonding method of the present invention, the conductive particles and the insulating particles are mixed in the region near the edge of the opposing region between the glass substrate and the flexible substrate . Aggregation of particles (dispersed particles gather together and harden) is suppressed, and occurrence of short-circuit defects is suppressed. Further, the first insulating adhesive resin insulating particles are dispersed in the edges of the facing region is arranged, a second inner conductive particles of the opposite edges of the facing region is dispersed Since the first and second insulating adhesive resins are pressurized and heated in a state where the insulating adhesive resin is arranged, the opposing region between the glass substrate and the flexible substrate after the pressing and heating is arranged. There will be no or little insulating particles inside the edge. Therefore, the contact between the conductive particles and each substrate is not hindered. Further, in the region where conduction between the electrodes is required, the particle density does not increase, and the first insulating adhesive resin in which the insulating particles are dispersed is disposed at the edge of the facing region. Since the flow rate of the particles is relaxed (decelerated), the adhesion between each substrate and the insulating adhesive resin does not decrease. Therefore, according to the electrode joining method of the present invention, it is possible to suppress the occurrence of short-circuit defects and suppress the occurrence of migration defects, and cope with the narrow pitch between electrodes.

According to the electrode bonded structure of the present invention, since the insulating particles that suppress the contact between the conductive particles are provided in the region near the edge of the facing region, aggregation of the conductive particles is suppressed by the insulating particles. The occurrence of short-circuit defects can be suppressed. In addition, since the insulating particles are not dispersed inside the edge of the opposing region, the contact between the conductive particles and each substrate is not hindered, and the particle density is high in the region where conduction between the electrodes is required. Therefore, the adhesion between each substrate and the insulating adhesive resin does not decrease, and the occurrence of migration failure can be suppressed.

Before continuing the description of the present invention, the same parts are denoted by the same reference numerals in the accompanying drawings.
The best mode for carrying out the present invention will be described below with reference to the drawings.

<< First Embodiment >>
The configuration of the electrode joint structure according to the first embodiment of the present invention will be described with reference to FIGS. 1A to 1D. In the first embodiment of the present invention, a description will be given taking as an example a bonding structure of a glass substrate and a flexible substrate, which is a bonding structure of terminal portions of a flat panel. 1A is a plan view showing a configuration of an electrode bonding structure according to a first embodiment of the present invention, FIG. 1B is a cross-sectional view along aa in FIG. 1A, and FIG. 1C is a cross-sectional view along b- in FIG. 1A. It is b sectional drawing, FIG. 1D is cc sectional drawing of FIG. 1A.

The electrode joint structure according to the first embodiment of the present invention includes a glass substrate 4 that is an example of a first circuit forming body having a plurality of first electrodes 4A, and a plurality of first electrodes 4A of the glass substrate 4. The flexible substrate 5 which is an example of a second circuit forming body having a plurality of second electrodes 5A disposed to face each other, and the glass substrate 4 and the flexible substrate 5 are disposed in a facing region 51 and both are disposed. Insulating adhesive resin 20 to be joined, a plurality of first electrodes 4A of glass substrate 4 dispersed in insulating adhesive resin 20, and a plurality of second electrodes 5A of flexible substrate 5 facing them Conductive particles 3 that are connected to each other, and insulating particles 7 that are dispersed in the insulating adhesive resin 20 in the vicinity region 52 of the edge portion 51A of the facing region 51 and suppress contact between the conductive particles 3. I have.
Here, “the edge portion 51A of the facing region 51” is located at a portion that hardly affects the conduction between the entire electrodes.

The plurality of first electrodes 4A of the glass substrate 4 are constituted by thick film electrodes (for example, thick film silver electrodes) having a thickness of about 3 μm to 5 μm, for example.
The plurality of second electrodes 5A of the flexible substrate 5 are constituted by thick film electrodes (for example, thick film copper electrodes) having a thickness of about 10 to 20 μm, for example.

  The insulating adhesive resin 20 is disposed so as to seal the plurality of first electrodes 4 </ b> A of the glass substrate 4 and the plurality of second electrodes 5 </ b> A of the flexible substrate 5. The insulating adhesive resin 20 includes a first insulating adhesive resin 6 in which the insulating particles 7 are dispersed (preferably uniformly) and a first insulating resin 6 in which the conductive particles 3 are dispersed (preferably uniformly). 2 insulating adhesive resins 2. The first insulating adhesive resin 6 is mainly disposed in the vicinity region 52 of the edge portion 51 </ b> A of the facing region 51. The second insulating adhesive resin 2 is mainly disposed inside the edge portion 54 of the facing region 51. Although the vicinity of the boundary between the first insulating adhesive resin 6 and the second insulating adhesive resin 2 is shown in FIGS. 1A to 1D as being adjacent to each other for the sake of illustration, They may be mixed.

The first insulating adhesive resin 6 is, for example, an acrylic resin that is cured at a low temperature and in a short time when pressed and heated, and a surface such as heat resistance, moisture absorption resistance, adhesiveness, and insulation. It is composed of a thermosetting resin such as an epoxy resin that is functionally superior.
Moreover, the 2nd insulating adhesive resin 2 is also comprised with thermosetting resins, such as an acrylic resin and an epoxy resin, similarly to the 1st insulating adhesive resin 6. FIG.

  The conductive particle 3 is, for example, a particle in which a metal sphere or a resin ball is used as a core, nickel plating is formed on the surface, and gold plating is further formed on the surface of the nickel plating. The average particle diameter of the conductive particles 3 is preferably formed within a range of 3 to 15 μm. When the average particle diameter of the conductive particles 3 is less than 3 μm, it is difficult to ensure conduction between the electrodes, and when the average particle diameter of the conductive particles 3 exceeds 15 μm, short-circuit failure between the electrodes is caused. There is a disadvantage that it is likely to occur.

The insulating particles 7 are particles that suppress contact between the conductive particles 3, that is, particles that prevent aggregation of the conductive particles 3 that cause a short circuit failure. The insulating particles 7 are made of, for example, an insulating material such as SiO ₂ (silica), ceramics, or alumina. Among the above, it is more preferable to select SiO ₂ (silica) having a low thermal conductivity as the material of the insulating particles 7. Since SiO ₂ (silica) has high insulating properties, low hygroscopicity, and is easily processed into fine particles, it is optimal as a material for the insulating particles 7 dispersed in the first insulating adhesive resin 6. is there.

The average particle diameter of the insulating particles 7 is preferably set to be the same as or smaller than the average particle diameter of the conductive particles 3. When the average particle diameter of the insulating particles 7 is larger than the average particle diameter of the conductive particles 3, the flow of the conductive particles 3 may be hindered by the insulating particles 7 at the time of bonding, which may cause migration failure. Becomes higher. Further, the insulating particles 7 are dispersed in the vicinity region 52 of the edge portion 51A of the facing region 51. At the time of bonding, the insulating particles 7 are regions that require conduction between the electrodes (first and It is possible that even a slight amount will be mixed into the second electrode 4A, 5A. In such a case, when the average particle diameter of the insulating particles 7 is larger than the average particle diameter of the conductive particles 3, the conduction between the first electrode 4A and the second electrode 4B by the conductive particles 3 is reduced. May be hindered.
When the average particle diameter of the insulating particles 7 is extremely smaller than the average particle diameter of the conductive particles 3, the insulating particles 7 suppress the contact between the conductive particles 3 and the conductive particles 3. Since it becomes difficult to prevent aggregation, the average particle diameter of the insulating particles 7 is preferably set to have an appropriate size. Specifically, the average particle diameter of the insulating particles 7 is more preferably set to 50% or more of the average particle diameter of the conductive particles 3.

The electrode joint structure according to the first embodiment of the present invention is configured as described above.
According to the electrode bonded structure according to the first embodiment of the present invention, the insulating region 7 that suppresses the contact between the conductive particles 3 is provided in the region 52 near the edge 51A of the facing region 51. Aggregation of the conductive particles 3 is suppressed by the conductive particles 7 and occurrence of short-circuit defects is suppressed. Further, since the insulating particles 7 are not dispersed inside the edge portion 51A of the facing region 51, the contact between the conductive particles 3, the glass substrate 4 and the flexible substrate 5 is not hindered, and conduction between the electrodes is not caused. Since the particle density does not increase in the region where the resistance is necessary, the adhesion between the glass substrate 4 and the flexible substrate 5 and the insulating adhesive resin 20 does not decrease, and the occurrence of migration failure can be suppressed.

  In addition, according to the electrode bonded structure according to the first embodiment of the present invention, the average particle size of the insulating particles 7 is the same or smaller than the average particle size of the conductive particles 3. Therefore, it is possible to suppress the flow of the conductive particles 3 from being hindered by the insulating particles 7, thereby avoiding a short circuit failure and suppressing the occurrence of a migration failure. Further, even when the insulating particles 3 are not intentionally mixed between the first and second electrodes 4A and 5A at the time of joining, between the first and second electrodes 4A and 5A due to the conductive particles 3 Conductivity (electrical connection) can be ensured, and highly reliable joining quality can be realized.

  Moreover, according to the electrode junction structure concerning 1st Embodiment of this invention, since generation | occurrence | production of migration is suppressed as mentioned above, the 1st electrode 4A of the glass substrate 4 can be formed with silver, and it is flat. It can be applied to display panels.

In the above description, a glass substrate is taken as an example of the first circuit forming body, but a printed wiring board, a flexible board, or the like may be used. In the above description, a flexible substrate is taken as an example of the second circuit forming body, but an electronic component such as an IC chip may be used.
In the above description, the materials and dimensions of each member have been described by way of example. However, the present invention is not limited to this, and can be modified in various ways.

  Next, an electrode bonding method for the electrode bonding structure according to the first embodiment of the present invention will be described with reference to FIGS. 2A to 2C, 3, and 4. 2A to 2C are cross-sectional views illustrating the procedure of the electrode bonding method for the electrode bonding structure according to the first embodiment of the present invention. FIG. 3 is a graph showing the change in melt viscosity with respect to time of the first insulating adhesive resin 6 and the second insulating adhesive resin 2. FIG. 4 is a flowchart of the electrode bonding method for the electrode bonding structure according to the first embodiment of the present invention.

In the first embodiment, the crimping tool 8 shown in FIG. 2B is used to perform electrode bonding between the glass substrate 4 and the flexible substrate 5. As shown in FIG. 2B, the crimping tool 8 includes a heater 8A for heating at the lower end portion thereof, an air cylinder 8B at the upper portion thereof, and is configured to be movable up and down by driving a separately provided motor 8C. ing. The crimping tool 8 has its lower end in contact with the glass substrate 4 or the flexible substrate 5 by the drive of the motor 8C, and in this contact state, air is supplied to the air cylinder 8B to drive the air cylinder 8B and the heater 8A for heating. Is a device configured to simultaneously pressurize and heat (pressurize and heat) the first and second insulating adhesive resins 2 and 6 by generating heat.
Further, in the first embodiment, although not shown, it is assumed that electrode bonding is performed by placing the glass substrate 4 on a support table that is a pressure-bonding stage with the glass substrate 4 facing down.

  First, in step S1, a glass substrate 4 having a plurality of first electrodes 4A and a second electrode 5A having a plurality of second electrodes 5A formed to face the plurality of first electrodes 4A of the glass substrate 4, respectively. As shown in FIG. 2B, the first insulating adhesive resin 6 in which the insulating particles 7 are dispersed is disposed on the edge 51 </ b> A of the facing region 51 with the second circuit molded body 5. The second insulating adhesive resin 2 in which the conductive particles 3 are dispersed is disposed inside the edge portion 51 </ b> A adjacent to the first insulating adhesive resin 6.

  There are various methods for arranging the first and second insulating adhesive resins 2 and 6 as in step S1. For example, the first insulating adhesive resin 6 in which the insulating particles 7 are dispersed on the plurality of first electrodes 4 </ b> A of the glass substrate 4 or the plurality of electrodes 5 </ b> A of the flexible substrate 5 and on the edge 51 </ b> A of the facing region 51. And the conductive particles 3 are dispersed on the plurality of first electrodes 4A of the glass substrate 4 or the plurality of electrodes 5A of the flexible substrate 5 and inside the edge portion 51A of the facing region 51. The above arrangement can also be realized by attaching the insulating adhesive resin 2 and then superposing the glass substrate 4 and the flexible substrate 5. In FIG. 2A, as an example, the anisotropic conductive sheet 1 is pasted on the plurality of first electrodes 4A of the glass substrate 4, and the insulating particles 7 are dispersed on the plurality of second electrodes 5A of the flexible substrate 5. The state which affixed 1st insulating adhesive resin 6 was shown is shown.

  In addition, the edge part 51A of the opposing area | region 51 is located in the part which has little influence on the conduction | electrical_connection between the whole electrodes as mentioned above. For example, when the length (the horizontal direction in FIG. 2B) of the second insulating adhesive resin 2 disposed inside the edge 51A, which is a region where conduction between electrodes is required, is 3 mm, the edge The length of the first insulating adhesive resin 6 disposed at 51A is about 0.1 mm to 1.0 mm.

The first insulating adhesive resin 6 is arranged on the side that flows when the second insulating adhesive resin 2 is pressurized and heated, that is, on the portion where the aggregation of the conductive particles 3 is likely to occur. It is only necessary that the second insulating adhesive resin 2 is disposed around the entire circumference. For example, when the second insulating adhesive resin 2 flows only in the left and right directions in FIG. 1A, the second insulating adhesive resin 2 may be disposed on both the left and right sides. Even if the conductive particles 3 are likely to aggregate, it is not necessary to dispose the first insulating adhesive resin 6 in a portion where the possibility of short circuit failure is low or absent. In the first embodiment of the present invention, the second insulating adhesive resin 2 flows mainly toward the end side of the glass substrate 4 (the right side in FIG. 2B), and the end of the flexible substrate 5 Each figure is illustrated on the part side (left side of FIG. 2B) on the assumption that the second insulating adhesive resin 2 hardly flows. Therefore, the first insulating adhesive resin 6 disposed on the edge 51 </ b> A on the end side of the glass substrate 4 is the first insulating adhesive disposed on the edge 51 </ b> A on the end side of the flexible substrate 5. It is formed larger than the resin 6.

  In addition, the form of the 2nd insulating adhesive resin 2 used by said step S1 may be a paste form, or the sheet (film) form. For example, an anisotropic conductive paste, an anisotropic conductive film, or an anisotropic conductive sheet may be used. Among them, it is preferable to use an anisotropic conductive sheet because of excellent workability and handleability.

  The thickness of the second insulating adhesive resin 2 is preferably set in the range of 15 μm to 60 μm. When the thickness of the second insulating adhesive resin 2 is less than 15 μm, the electrode bonding strength between the first and second electrodes 4A and 5A becomes insufficient and easily peels, and when the thickness exceeds 60 μm It becomes difficult to establish electrical connection between the first and second electrodes 4A and 5A. The thickness of the second insulating adhesive resin 2 is preferably set according to the thickness of the first electrode 4A or the second electrode 5A, for example, the first electrode 4A or the second electrode If the thickness of the electrode 5A is 10 to 20 μm, it is preferably set in a range of about 35 μm to 50 μm.

  In addition, the shape of the second insulating adhesive resin 2 is not particularly limited, and the width and length thereof depend on the shape of the first electrode 4A or the second electrode 5A, and are conductive particles. 3 may be set so that electrical connection between the first and second electrodes 4A and 5A can be secured.

  The form of the first insulating adhesive resin 6 used in the step S1 may be a paste or a sheet (film) as in the case of the second insulating adhesive resin 2. If a paste-like form is used as the first insulating adhesive resin 6, a plurality of glass substrates 4 or flexible substrates 5 can be formed by a method such as application by a dispenser, mask printing, or coater coating, for example. The first and second electrodes 4A and 5A may be supplied. Alternatively, the first insulating adhesive resin 6 in the form of a paste may be formed into a sheet by a known method such as coater coating, wound around a reel, and supplied to the reel as necessary.

In addition, the thickness of the first insulating adhesive resin 6 is preferably set to be approximately equal to or less than the thickness of the second insulating adhesive resin 2. When the thickness of the first insulating adhesive resin 6 is larger than the thickness of the second insulating adhesive resin 2, the glass substrate 4 and the flexible substrate 5 are overlapped as shown in FIG. 2B. When they are combined, the first and second insulating adhesive resins 2 and 6 vary in height in the thickness direction, and this variation may cause misalignment, leading to poor connection.
Further, the shape of the first insulating adhesive resin 6 is not particularly limited, and the width and length thereof are set according to the shape of the first electrode 4A or the second electrode 5A, respectively. That's fine.

In addition, the volume density of the insulating particles 7 in the first insulating adhesive resin 6 is preferably the same or smaller than the volume density of the conductive particles 3 in the second insulating adhesive resin 2. When the volume density of the insulating particles 7 in the first insulating adhesive resin 6 is larger than the volume density of the conductive particles 3 in the second insulating adhesive resin 2, the conductive particles 3 flow. In some cases, the insulating particles 7 serve as a barrier to inhibit the flow of the conductive particles 3 and the conductive particles 3 tend to aggregate. Further, the insulating adhesive particles 3 are mixed in a large amount on the inner side (electrode bonding side) of the edge portion 51A of the facing region 51, and the electrical connection between the first and second electrodes 4A and 5A by the conductive particles 3 is performed. The possibility of inhibiting is increased.
If the volume density of the insulating particles 7 in the first insulating adhesive resin 6 is extremely smaller than the volume density of the conductive particles 3 in the second insulating adhesive resin 2, the insulating particles 7 makes it difficult to prevent contact between the conductive particles 3 and prevent aggregation of the conductive particles 3, so that the volume density of the insulating particles 7 is set to have an appropriate size. Is preferred. Specifically, the volume density of the insulating particles 7 is more preferably set to 50% or more of the volume density of the conductive particles 3.

  Also, as shown in FIG. 3, the first insulating adhesive resin 6 (shown by a thick line in FIG. 3) melts before the second insulating adhesive resin 2 (shown by a broken line in FIG. 3). Then, when the second insulating adhesive resin 2 starts to melt and harden, the melt viscosity is higher than or equal to the melt viscosity of the second insulating adhesive resin 2. It is preferable to be configured as follows.

Such a configuration, for example, lowers the melting temperature at which the first insulating adhesive resin 6 reaches the minimum melt viscosity F ₁ lower than the melting temperature at which the second insulating adhesive resin 2 reaches the minimum melt viscosity F _2. Alternatively, it can be realized by setting the same level. Specifically, for example, when an anisotropic conductive sheet is used as the second insulating adhesive resin 2, the melting temperature of a general anisotropic conductive sheet is about 120 to 130 ° C. What is necessary is just to set the melting temperature of 1 insulating adhesive resin 6 to the temperature lower than 120-130 degreeC (preferably 80-120 degreeC).

  When the melting temperature of the first insulating adhesive resin 6 is higher than the melting temperature of the second insulating adhesive resin 2 (120 to 130 ° C. or more in the above example), the second insulating property After the adhesive resin 2 first reaches the minimum melt viscosity and starts to be cured, the first insulating adhesive resin 6 is delayed and reaches the minimum melt viscosity to start the cure. In this case, a large amount of the conductive particles 3 tends to flow and aggregate on the edge 51A side of the facing region 51, and the aggregation of the conductive particles 3 may not be suppressed. Further, the melting temperature of the first insulating adhesive resin 6 is made extremely lower than the melting temperature of the second insulating adhesive resin 2 and the second insulating adhesive resin 2 starts to melt. Further, when the first insulating adhesive resin 6 is in a cured state after being melted, the insulating particles 7 and the conductive particles 3 are not effectively mixed, and the conductive particles 3 are aggregated. May not be suppressed.

  As described above, as a method of adjusting the melt viscosity and the melt temperature of the first and second insulating adhesive resins 2 and 6, for example, the first insulating adhesive resin 6 and the second insulating adhesive can be used. There are a method of making the material of the agent resin 2 a different material (a different component), a method of making a difference in molecular weight, and the like. Moreover, as a method of making a difference in the change in melt viscosity with respect to time of the first and second insulating adhesive resins 2 and 6, for example, the thermal conductivity of the first insulating adhesive resin 6 is the second. There is a method of appropriately selecting the material of the insulating particles 7 dispersed in the first insulating adhesive resin 6 so as to be lower than the thermal conductivity of the insulating adhesive resin 2.

  Subsequent to step S1, in step S2, the first and second insulating adhesive resins 2 and 6 are simultaneously pressurized and heated by the crimping tool 8 via the glass substrate 4 or the flexible substrate 5, and the glass is heated. The plurality of first electrodes 4 </ b> A of the substrate 4 and the plurality of second electrodes 5 </ b> A of the flexible substrate 5 that oppose them are electrically joined to each other through the conductive particles 3, and the edge portion 51 </ b> A of the facing region 51. The conductive particles 3 and the insulating particles 7 are mixed in the vicinity region 52.

  The change in the melt viscosity with respect to time of the first insulating adhesive resin 6 and the second insulating adhesive resin 2 in step S2 will be described in detail with reference to FIG. In FIG. 3, the change of the melt viscosity with respect to time of the first insulating adhesive resin 6 is indicated by a bold line, and the change of the melt viscosity with respect to time of the second insulating adhesive resin 2 is indicated by a broken line.

As shown in FIG. 2B, the glass substrate 4 and the flexible substrate 5 are stacked using the crimping tool 8 with the first and second insulating adhesive resins 2 and 6 being sandwiched between them. When the first and second insulating adhesive resins 2 and 6 are simultaneously pressurized and heated through the first and second insulating adhesive resins 6, first, the first insulating adhesive resin 6 is more than the second insulating adhesive resin 2. First, it melts (softens) and starts to flow and reaches the minimum melt viscosity F ₁ (region A in FIG. 3). At this time, the second insulating adhesive resin 2 begins to melt and catch-up flow to the first insulating adhesive resin 6, it reaches the minimum melt viscosity F ₂ (area of Figure 3 C). That is, when the first insulating adhesive resin 6 reaches the minimum melt viscosity, the second insulating adhesive resin 2 is in a softened and flowing state, and the second insulating adhesive at that time The melt viscosity of the agent resin 2 is higher than the melt viscosity of the first insulating adhesive resin 6.

The first insulating adhesive resin 6, after reaching a minimum melt viscosity F _1, and cured gradually reaches cured state (region in FIG. 3 B). In the course of curing of the first insulating adhesive resin 6, a second insulating adhesive resin 2 reaches the minimum melt viscosity F _2. At this time, the melt viscosity of the first insulating adhesive resin 6 is higher than the melt viscosity of the second insulating adhesive resin 2.
After the second insulating adhesive resin 2 reaches the minimum melt viscosity F ₂ , it gradually cures and follows the first insulating adhesive resin 6 to reach a cured state (region D in FIG. 3). .

  From such a melting state relationship, after the first insulating adhesive resin 6 is melted (softened) and starts to flow, the second insulating adhesive resin 2 melts (softens) and flows. In the period I in FIG. 3 until the start, the filling property of the second insulating adhesive resin 2 between the plurality of first or second electrodes 4A and 5A is increased, and the first due to insufficient pressurization. This is a process for improving the adhesion between the insulating adhesive resin 2 and the glass substrate 4 and the flexible substrate 5.

Further, the period II in FIG. 3 from when the second insulating adhesive resin 2 melts (softens) and starts to flow until it reaches the minimum melt viscosity F ₂ is the first insulating adhesive resin 6. Since the fluidity of the second insulating adhesive resin 2 and the conductive particles 3 is eased by melting and curing prior to the second insulating adhesive resin 2, the second due to insufficient pressurization. This improves the adhesion between the insulating adhesive resin 2 and the glass substrate 4 and the flexible substrate 5, and the insulating particles 7 suppress the aggregation of the conductive particles 3.

Further, during the period III in FIG. 3 from when the second insulating adhesive resin 2 reaches the minimum melt viscosity F ₂ until reaching the cured state, the conductive particles 3 are prevented from aggregating by the insulating particles 7. The first and second insulating adhesive resins 2 and 6 are cured in a dispersed state.

  According to the electrode bonding method according to the first embodiment of the present invention, the conductive particles 3 and the insulating particles 7 are mixed in the vicinity region 52 of the edge portion 51 </ b> A of the facing region 51 between the glass substrate 4 and the flexible substrate 5. As a result, the insulating particles 7 suppress the aggregation of the conductive particles 3 and suppress the occurrence of short circuit defects. In addition, the first insulating adhesive resin 6 in which the insulating particles 7 are dispersed is disposed at the edge 51A of the facing region 51, and the conductive particles 3 are dispersed inside the edge 51A of the facing region 51. Since the first and second insulating adhesive resins 2 and 6 are pressurized and heated in a state where the two insulating adhesive resins 2 are arranged, the glass substrate 4 after being pressurized and heated is used. No or almost no insulating particles 7 are present inside the edge 51 </ b> A of the facing region 51 facing the flexible substrate 5. Therefore, contact (electrical connection) between the conductive particles 3 and the glass substrate 4 and the flexible substrate 5 is not hindered. In addition, the particle density does not increase in the region where conduction between the electrodes is necessary, and the first insulating adhesive resin 6 in which the insulating particles 7 are dispersed is arranged on the edge 51A of the facing region 51. Since the flow rate of the conductive particles 3 is relaxed (decelerated), the adhesion between the first and second circuit molded bodies 4 and 5 and the second insulating adhesive resin 2 does not decrease. Therefore, according to the electrode joining method according to the first embodiment of the present invention, it is possible to suppress the occurrence of short-circuit defects and suppress the occurrence of migration defects, and cope with a narrow pitch between electrodes of, for example, 0.1 mm or less. In addition, it is possible to ensure reliability when a high voltage is applied between the electrodes. Thereby, especially in the flat panel joining technique represented by the electrode joining of the glass substrate and the flexible substrate, the effect of the electrode joining method according to the first embodiment of the present invention is great.

  In addition, according to the electrode joining method according to the first embodiment of the present invention, the first and second insulating adhesive resins 2 and 6 can be simultaneously pressurized and heated in a simple (one) operation. Since the above effect can be obtained, there is also a specific effect that the time required for performing electrode joining of a set of circuit formed bodies is short.

  Further, according to the electrode bonding method according to the first embodiment of the present invention, the first insulating adhesive resin 6 starts to melt and harden before the second insulating adhesive resin 2, and thereafter When the second insulating adhesive resin 2 starts to melt and harden, the melt viscosity is higher than or equal to the melt viscosity of the second insulating adhesive resin 2. Therefore, the flow rate of the second insulating adhesive resin in which the conductive particles are dispersed can be more effectively reduced, and the filling rate of the insulating adhesive resin between the first and second electrodes can be reduced. The adhesion between the circuit molded body and the insulating adhesive resin can be improved.

  Moreover, according to the electrode joining method according to the first embodiment of the present invention, the volume density of the insulating particles 7 in the first insulating adhesive resin 6 is the conductive particles 3 in the second insulating adhesive resin 2. Therefore, the flow of the conductive particles 3 is inhibited from being inhibited by the insulating particles 7, so that a short circuit failure can be avoided and a migration failure can be generated. Can be suppressed.

<< Second Embodiment >>
An electrode bonding structure and an electrode bonding method according to the second embodiment of the present invention will be described with reference to FIGS. FIG. 5 is a cross-sectional view of an electrode joint structure according to a second embodiment of the present invention. FIG. 6 is a flowchart of an electrode bonding method for an electrode bonding structure according to a second embodiment of the present invention. The electrode joint structure according to the second embodiment of the present invention is different from the electrode joint structure according to the first embodiment of the present invention in that it further includes an insulating sealing resin 10. In the electrode joining method according to the second embodiment of the present invention, after step S2, the step 52 of step S3 is performed to cover the region 52 near the edge 51A of the facing region 51 so as not to be exposed to the outside by the insulating sealing resin. Is further different from the electrode joining method according to the first embodiment of the present invention. Since the other points are the same, redundant description will be omitted, and differences will be mainly described.

As shown in FIG. 5, the insulating sealing resin 10 is provided so as to cover (seal) the vicinity region 52 of the edge portion 51 </ b> A of the facing region 51 so as not to be exposed to the outside. That is, the insulating sealing resin 10 is provided so as to seal the electrode joint portion between the glass substrate 4 and the flexible substrate 5.
By providing the insulating sealing resin 10 in this way, it is possible to prevent water, corrosive gas, or the like from entering the electrode joint portion between the glass substrate 4 and the flexible substrate 5 from the outside. In addition, since the oxidation of the first and second electrodes 4A and 5A and the conductive particles 3 is prevented and electrical conduction is not hindered, highly reliable bonding quality can be realized. Further, since the insulating sealing resin 10 is cured, the bonding strength of the first and second electrodes 4A and 5A is reinforced, and the reliability with respect to the mechanical bending strength and the like is improved.

The insulating sealing resin 10 is preferably composed of a silicone resin, a UV curable resin such as urethane or polybutadiene, or the like. The insulating sealing resin 10 may be cured by heat, cured by light, or cured by a combination of light and heat.
Moreover, as a material of the insulating sealing resin 10, it is preferable to use a solvent-free resin from the viewpoint of work environment and the problem of redeposition of volatile components.
Further, the insulating sealing resin 10 is also required to have a characteristic of preventing ion migration that occurs when a voltage is applied in a high temperature and high humidity environment. For this reason, as the material of the insulating sealing resin 10, it is preferable to use a material having low water permeability and few ionic impurities.
Furthermore, the material of the insulating sealing resin 10 has a certain degree of flexibility so as to have a reinforcing effect on the bonding strength of the first and second electrodes 4A and 5A and to follow the deformation of the flexible substrate 5. Preferably it is an elastic body

  Moreover, it is preferable that the thickness of the insulating sealing resin 10 is set in a range of 0.1 mm to 5.0 mm. When the thickness of the insulating sealing resin 10 is less than 0.1 mm, it is possible to prevent water or corrosive gas from entering the electrode joint portion between the glass substrate 4 and the flexible substrate 5 from the outside. When the thickness of the insulating sealing resin 10 exceeds 5 mm, it takes time to cure the insulating sealing resin 10 and the tact time becomes long.

  In addition, as a method for forming the insulating sealing resin 10, it is preferable to adopt a method in which the insulating sealing resin 10 is formed by application using a dispenser. The coating viscosity in this case is preferably in the range of about 2 mPa · s to 20 Pa · s from the viewpoint of applicability. However, the present invention is not limited to this, and a method of forming by screen printing, inkjet, coater, or the like may be employed according to the viscosity of the insulating sealing resin 10.

  Further, when forming the insulating sealing resin 10, it is preferable to perform UV cleaning in advance in order to improve the adhesion between the glass substrate 4 and the flexible substrate 5 and the insulating sealing resin 10. The electrode bonded structure produced in this way is excellent in long-term bonding reliability, and can cope with a narrow pitch between electrodes having a pitch of 0.1 mm or less, for example.

"Example"
Next, an example which is one of the specific examples of the electrode bonding method according to the second embodiment of the present invention will be described with reference to FIGS. 1A to 1D and FIGS. 2A to 2C. First, a specific configuration of each component will be described.

In the present embodiment, the first circuit formed body has a plurality of first electrodes 4A formed of silver having a thickness of 3 μm on a glass having a thickness of 1.8 mm and having a width of L / S = 50 μm / 50 μm. The glass substrate 4 is made up of. L represents the width of the electrode, and S represents the width of the gap between the adjacent electrodes.
Further, in this example, the second circuit formation body has a plurality of second electrodes 5A formed of copper having a thickness of 12 μm on a polyimide film having a thickness of 50 μm with a width of L / S = 50 μm / 50 μm. The flexible substrate 5 is arranged. That is, the pitch between the electrodes having the above configuration is 50 μm + 50 μm = 100 μm = 0.1 mm.
In this embodiment, the first insulating adhesive resin is a thermosetting film having a thickness of 35 μm, in which insulating particles 7 made of SiO ₂ (silica) and having an average particle diameter of about ₂ to 4 μm are uniformly dispersed. It is comprised with the insulating adhesive resin sheet 6 which has an epoxy resin as a main component.
Further, in this example, the second insulating adhesive resin uniformly dispersed the conductive particles 3 formed to have an average particle diameter of about 8 μm by metal plating with Ni—Au using a resinous ball as a core. The anisotropic conductive sheet 2 is mainly composed of a thermosetting epoxy resin having a thickness of 35 μm.
The volume density of the insulating particles 7 in the insulating adhesive resin sheet 6 is approximately the same as the volume density of the conductive particles 3 in the anisotropic conductive sheet 2.

In this embodiment, the insulating sealing resin 10 is made of a resin made of polybutadiene acrylate that is cured with a mercury lamp with an integrated light quantity of 2000 mJ / cm ² .
The material of the insulating sealing resin 10 is particularly low in impurity chlorine ion concentration of several ppm, low in water absorption, and excellent in resistance to ion migration that occurs when voltage is applied in a high temperature and high humidity environment. Whether or not there was a selection criterion.
In addition, in the electrode joint structure that employs an epoxy acrylate resin as the material of the insulating sealing resin 10, since the impurity chlorine ion concentration of the resin is relatively high due to contamination from the raw material, it is insulated by THB reliability test. It is confirmed that a defect occurs.

Hereinafter, the electrode joining method of the present embodiment will be described.
First, as shown in FIG. 2A, the anisotropic conductive sheet 2 is pasted on the plurality of electrodes 4 </ b> A of the glass substrate 4 and inside the edge 51 </ b> A of the facing region 51, and the plurality of electrodes 5 </ b> A of the flexible substrate 5. The insulating adhesive resin sheet 6 is affixed to the edge 51 </ b> A of the facing region 51.

  Next, as shown in FIG. 2B, the glass substrate 4 and the flexible substrate 5 are aligned so that the bonded anisotropic conductive sheet 2 and insulating adhesive resin sheet 6 are adjacent to each other without overlapping. Are superimposed (step S1 in FIG. 6).

  Next, the anisotropic conductive sheet 2 and the insulating adhesive resin sheet 6 are simultaneously pressed and heated by the heating heater 8A of the crimping tool 8 and the air cylinder 8B via the flexible substrate 5, and the glass substrate 4 is heated. The plurality of first electrodes 4 </ b> A and the plurality of second electrodes 5 </ b> A of the flexible substrate 5 facing them are electrically joined via the conductive particles 3, and in the vicinity of the edge 51 </ b> A of the facing region 51. In the region 52, the conductive particles 3 and the insulating particles 7 are mixed (step S2 in FIG. 6). At this time, the heating temperature by the heating heater 8A is set to 180 ° C. with respect to the anisotropic conductive sheet 2 and the insulating adhesive resin sheet 6, and the pressing force by the air cylinder 8B is set to 3 MPa. Their pressurization and heating time was set to 10 seconds.

Next, after UV cleaning is performed on the region 52 in the vicinity of the edge 51A of the facing region 51, the insulating sealing resin 10 is applied using a dispenser (manufactured by Musashi Engineering) and is covered so as not to be exposed to the outside ( Step S3 in FIG. At this time, the coating amount of the insulating sealing resin 10 was such that the thickness after photocuring was about 0.5 mm.
In addition, when the thickness of the insulating sealing resin 10 after photocuring is reduced to about several tens of μm, the surface is inhibited from being cured, and the surface remains sticky even after UV irradiation. In this state, the THB test was performed. It has been confirmed that the insulating sealing resin 10 sucks water and causes insulation failure.

  The electrode bonded structure bonded by the above electrode bonding method is excellent in adhesion between the glass substrate 4 and the flexible substrate 5 and the anisotropic conductive sheet 2, the occurrence of migration failure is suppressed, and the opposing region 51 In the vicinity region 52 of the edge portion 51A, the insulating particles 7 suppress the aggregation of the conductive particles 3, and the occurrence of short-circuit defects is also suppressed. Therefore, it is possible to cope with a narrow pitch between electrodes having a pitch of 0.1 mm or less.

  Next, referring to FIGS. 7A to 7C, 8A to 8C, 9, and 10, the electrode bonding structure when the second circuit formation body is a rectangular electronic component 15 such as an IC chip component. Will be described. 8A to 8C, for convenience of illustration, the vicinity of the boundary between the first insulating adhesive resin 6 and the second insulating adhesive resin 2 is shown as being adjacent to each other. , They may be mixed.

FIG. 7A is a schematic plan view showing the structure of an electrode joint structure when the second circuit forming body is an electronic component 15 in the related art. FIG. 7A shows a state in which the electronic component 15 has been removed in order to facilitate understanding of the structure of the electrode joint portion. 7B is a sectional view taken along the line dd of FIG. 7A, and FIG. 7C is a sectional view taken along the line ee of FIG. 7A. In addition, the big ellipse in FIG. 7A has shown the area | region where aggregation of the electroconductive particle 3 has generate | occur | produced.
FIG. 8A is a schematic plan view showing the structure of the electrode joint structure when the second circuit forming body is the electronic component 15 in the first embodiment of the present invention. FIG. 8A shows a state in which the electronic component 15 has been removed in order to facilitate understanding of the structure of the electrode joint portion. 8B is a sectional view taken along line ff in FIG. 8A, and FIG. 8C is a sectional view taken along line gg in FIG. 8A. The white circles in FIG. 8A indicate the conductive particles 3, and the black circles indicate the insulating particles 7.

  When the second circuit formed body is the electronic component 15, the plurality of second electrodes 5 </ b> A arranged along each side portion of the rectangular electronic component 15 are opposed to the second electrode 5 </ b> A and FIGS. When the plurality of electrodes 4A of the glass substrate 4 are arranged as shown in FIGS. 8A to 8C and the first insulating adhesive resin 6 is heated and pressed by the crimping tool 8, the first insulating property is obtained. The adhesive resin 6 spreads mainly in the vertical and horizontal directions in FIGS. 7A and 8A. For this reason, when the electrode bonded structure is bonded, the arrangement of the first insulating adhesive resin 6 and the second insulating adhesive resin 2 is different from the configuration shown in FIG. 1A.

In FIG. 9, as an example, the single second insulating adhesive resin 2 is disposed so as to cover (seal) all of the plurality of first electrodes 4 </ b> A of the glass substrate 4, and the first insulating adhesive The structure by which the 1st insulating adhesive resin 6 is arrange | positioned along the perimeter of the agent resin 6 is shown.
Moreover, the 1st insulating adhesive resin 6 should just be arrange | positioned at the side which flows, when the 2nd insulating adhesive resin 2 is pressurized and heated as mentioned above. is there. When the second circuit forming body is a rectangular electronic component 15, the flow rate of the second insulating adhesive resin 2 that has been pressurized and heated in the corners of the electronic component 15 as compared with other portions is higher. Slowly, even if the conductive particles 3 agglomerate, the possibility of short circuit failure is low.
FIG. 10 shows an example in which a single second insulating adhesive resin 2 is disposed so as to cover (seal) all of the plurality of first electrodes 4A of the glass substrate 4, and the corners of the electronic component 15 are arranged. A configuration in which the first insulating adhesive resin 6 is disposed in a portion other than the portion is shown.
The case where the second circuit formed body is the electronic component 15 has been described above. However, since points other than those described above are the same as other configurations, detailed description thereof will be omitted.

In addition, this invention is not limited to the said embodiment, It can implement with another various aspect.
It is to be noted that, by appropriately combining arbitrary embodiments of the various embodiments described above, the effects possessed by them can be produced.

  Since the electrode bonding method and the electrode bonding structure according to the present invention have the effect of suppressing the occurrence of short-circuit defects and the occurrence of migration defects, the conductive particles are connected to the electrodes of other circuit-formed bodies. Useful when a narrow pitch between adjacent electrodes is required in technology for joining using dispersed insulating adhesive resin, especially in flat panel joining technology represented by electrode joining between glass substrate and flexible substrate. It is.

It is a top view which shows the structure of the electrode junction structure concerning 1st Embodiment of this invention. It is aa sectional drawing of FIG. 1A. It is bb sectional drawing of FIG. 1A. It is cc sectional drawing of FIG. 1A. It is sectional drawing which shows the procedure of the electrode joining method of the electrode joining structure concerning 1st Embodiment of this invention. It is other sectional drawing which shows the procedure of the electrode joining method of the electrode joining structure concerning 1st Embodiment of this invention. It is other sectional drawing which shows the procedure of the electrode bonding method of the electrode bonding structure concerning 1st Embodiment of this invention. It is a graph which shows the change of the melt viscosity with respect to time of 1st insulating adhesive resin and 2nd insulating adhesive resin. It is a flowchart of the electrode bonding method of the electrode bonding structure concerning 1st Embodiment of this invention. It is sectional drawing of the electrode junction structure concerning 2nd Embodiment of this invention. It is a flowchart of the electrode joining method of the electrode joining structure concerning 2nd Embodiment of this invention. In the conventional electrode junction structure, it is a top view which shows the state which removed the electronic component when the 2nd circuit formation body is an electronic component. It is dd sectional drawing of FIG. 7A. It is ee sectional drawing of FIG. 7A. In the electrode junction structure concerning a 1st embodiment of the present invention, it is a top view showing the state where the electronic part was removed when the 2nd circuit formation object is an electronic part. It is ff sectional drawing of FIG. 8A. It is gg sectional drawing of FIG. 8A. It is a top view which shows the arrangement configuration of 1st and 2nd insulating adhesive resin when a 2nd circuit formation body is an electronic component. It is a top view which shows the other arrangement structure of 1st and 2nd insulating adhesive resin when a 2nd circuit formation body is an electronic component. It is sectional drawing which shows the procedure of the electrode bonding method of the conventional electrode bonding structure. It is other sectional drawing which shows the procedure of the electrode joining method of the conventional electrode joining structure. It is xx sectional drawing of FIG. 11B.

Explanation of symbols

2 Second Insulating Adhesive Resin 3 Conductive Particles 4 Glass Substrate 4A First Electrode 5 Flexible Substrate 5A Second Electrode 6 First Insulating Adhesive Resin 7 Insulating Particle 8 Crimping Tool 10 Insulating Seal resin

Claims (10)

An end of a glass substrate having a plurality of first electrodes, and an end of a flexible substrate having a plurality of second electrodes formed to face the plurality of first electrodes of the glass substrate, respectively. A first insulating adhesive resin in which insulating particles are dispersed is disposed on both edges of the opposing region, and second conductive particles are dispersed on the inner sides of both edges of the opposing region. Place the insulating adhesive resin,
The first and second insulating adhesive resins are pressurized and heated through the glass substrate or the flexible substrate, and the first electrode of the glass substrate and the flexible substrate facing the first electrode are the same. Electrode bonding in which each of the second electrodes is electrically bonded through the conductive particles, and the conductive particles and the insulating particles are mixed in a region in the vicinity of the both edges of the facing region. A method,
The first insulating adhesive resin disposed at the edge portion on the end side of the glass substrate in the facing region is the first insulating resin disposed on the edge portion on the end portion side of the flexible substrate in the facing region. The insulating adhesive resin is formed wider than the insulating adhesive resin in the direction connecting the both edges, and after the first and second insulating adhesive resins are heated under pressure , An electrode joining method in which only a region near the edge is covered with an insulating sealing resin. The first and second insulating adhesive resins are thermosetting resins,
The electrode joining method according to claim 1, wherein a melting temperature of the first insulating adhesive resin is lower than a melting temperature of the second insulating adhesive resin. The first and second insulating adhesive resins are thermosetting resins,
When the first and second insulating adhesive resins are heated under pressure, after the first insulating adhesive resin begins to melt, the second insulating adhesive resin begins to melt, and then The electrode joining method according to claim 1, wherein the second insulating adhesive resin starts to harden after the first insulating adhesive resin starts to harden.   The melt viscosity of the first insulating adhesive resin is higher than the melt viscosity of the second insulating adhesive resin when the second insulating adhesive resin begins to cure. Electrode joining method.   The electrode joining method according to any one of claims 1 to 4, wherein a thermal conductivity of the first insulating adhesive resin is lower than a thermal conductivity of the second insulating adhesive resin.   The electrode joining method according to any one of claims 1 to 5, wherein an average particle size of the insulating particles is the same or smaller than an average particle size of the conductive particles.   The volume density of the insulating particles in the first insulating adhesive resin is the same as or less than the volume density of the conductive particles in the second insulating adhesive resin. The electrode joining method according to any one of the above.   The electrode joining method according to claim 1, wherein the second insulating adhesive resin in which the conductive particles are dispersed is an anisotropic conductive sheet. A glass substrate having a plurality of first electrodes;
A flexible substrate having a plurality of second electrodes disposed respectively facing the plurality of first electrodes of the glass substrate;
A first insulating adhesive resin in which insulating particles that are disposed at both ends of an opposing region between the end of the glass substrate and the end of the flexible substrate and in which both are bonded are dispersed;
A second insulating adhesive resin in which conductive particles are dispersed, disposed on the inner side of the both edges of the opposing region;
An electrode joint structure comprising:
The first insulating adhesive resin disposed at the edge portion on the end side of the glass substrate in the facing region is the first insulating resin disposed on the edge portion on the end portion side of the flexible substrate in the facing region. From the insulating adhesive resin of, is formed widely in the direction connecting the both ends,
An electrode joint structure, further comprising an insulating sealing resin that covers only a region in the vicinity of the edge on the end side of the glass substrate.   The electrode junction structure according to claim 9, wherein the average particle size of the insulating particles is the same as or smaller than the average particle size of the conductive particles.

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