JP4661914B2 - Electrode connection method - Google Patents

Description

  The present invention relates to an electrode connection method using a connection member that bonds and fixes an electronic component and a circuit board or circuit boards together and electrically connects the two electrodes.

  In recent years, with the miniaturization and thinning of electronic components, circuits used for these have become denser and higher definition. Since it is difficult to connect such electronic components and fine electrodes with conventional solders or rubber connectors, anisotropically conductive adhesives and membranes with excellent resolution (hereinafter referred to as connecting members) Is frequently used. This connecting member is made of an adhesive containing a predetermined amount of a conductive material such as conductive particles, and this connecting member is provided between the electronic component and the electrode or circuit to form a pressurizing or heating / pressing means. As a result, the electrodes are electrically connected to each other, and the electrodes formed adjacent to the electrodes are provided with insulating properties so that the electronic component and the circuit are bonded and fixed. The basic idea for increasing the resolution of the connecting member is to ensure the insulation between the adjacent electrodes by making the particle size of the conductive particles smaller than the insulating portion between the adjacent electrodes. The amount is set so that the particles do not come into contact with each other and is surely present on the electrode to obtain conductivity at the connection portion.

JP-A-61-195179 JP-A-4-366630

  In the conventional method, when the particle size of the conductive particles is reduced, the particles are secondarily aggregated due to a significant increase in the surface area of the particles and are frozen, so that insulation between adjacent electrodes cannot be maintained. In addition, if the content of the conductive particles is reduced, the number of conductive particles on the electrodes to be connected also decreases, so the number of contact points is insufficient and conduction between the connection electrodes cannot be obtained. It has been extremely difficult to increase the resolution of the connecting member. In other words, due to the recent significant increase in resolution, that is, the electrode area and the miniaturization between adjacent electrodes (spaces), the conductive particles on the electrodes flow out between the adjacent electrodes together with the adhesive by the pressurization or heating and pressurization at the time of connection, This hinders high resolution of the connecting member. At this time, in order to suppress the outflow of the adhesive, if the adhesive has a high viscosity, the contact between the electrode and the conductive particles becomes insufficient, and it becomes impossible to connect the opposing electrodes. On the other hand, if the adhesive has a low viscosity, in addition to the outflow of the conductive particles, there is a drawback in that bubbles are likely to be included in the space portion and connection reliability, particularly moisture resistance is lowered.

  For this reason, the conductive material-containing layer and the insulating adhesive layer are decomposed into a multi-layered connection material, and the viscosity at the time of connecting the conductive particle-containing layer is higher than that of the insulating adhesive layer or has a higher cohesive force. Attempts to hold the conductive particles on the electrode by making the conductive particles difficult to flow are also found in, for example, Japanese Patent Application Laid-Open Nos. 61-195179 and 4-366630. Since the conductive particle-containing layer has a high viscosity at the time of connection, the contact between the electrode and the conductive particles becomes insufficient, and the connection resistance value is high, so that the connection reliability is unsatisfactory. Further, when the conductive particles are exposed from the conductive particle-containing layer so that the contact with the electrode can be easily obtained, it is necessary to increase the particle diameter of the conductive particles, and the resolution cannot be increased. In addition, as a connection member that enables connection of such fine electrodes and circuits and is excellent in connection reliability, there is also a proposal of a connection member having a dense region of conductive particles in necessary portions in both directions. According to this, although a dot-shaped fine electrode such as a semiconductor chip can be connected, there is a disadvantage that the precise alignment between the conductive particle dense region and the dot-shaped electrode is necessary and the workability is inferior.

  The present invention has been made in view of the above-described drawbacks, and since the conductive particles are difficult to flow out from the electrode during connection, the conductive particles can be held on the electrode, and contact between the electrode and the conductive particles can be easily obtained. The present invention relates to an electrode connection method using a high-resolution connection member that is excellent in connection reliability for a long time because it is difficult to include, and that accurate alignment between conductive particles and electrodes is unnecessary. In addition, it is possible to prevent unnecessary adhesion and dust from adhering to the circuit connection member, and a connection member that has good workability and can be used for continuous automation of the connection work process when the substrate on one side is a flat electrode is used. An electrode connection method is provided.

  The present invention relates to a circuit connection member in which a curable insulating adhesive layer is formed on at least one surface of an adhesive layer having conductivity in a pressing direction composed of a conductive material and a binder. An electrode connection method using a circuit connection member in contact with an insulating adhesive layer, wherein a protruding electrode formed on one substrate and a planar electrode formed on the other substrate face each other. Between the electrode rows, the circuit connecting member is placed so that the conductive adhesive layer is on the flat electrode side, the conductive adhesive layer is temporarily attached to the flat electrode side, the separator is peeled off, and the protruding electrode side This is a method for connecting electrodes to which a curable insulating adhesive layer is attached.

According to the present invention, there is provided a circuit connecting member in which a curable insulating adhesive layer is formed on at least one surface of an adhesive layer having conductivity in a pressurizing direction composed of a conductive material and a binder. Since the circuit connecting member is in contact with the curable insulating adhesive layer, unnecessary adhesion to the circuit connecting member and dust can be prevented, and the separator is in contact with the curable insulating adhesive layer. When the substrate is a planar electrode (for example, a display substrate such as a liquid crystal), a conductive adhesive layer without the separator 5 can be formed on the planar electrode side, which is convenient and convenient. In these cases, the continuous tape shape is preferable because continuous automation of the connection work process can be achieved.
In addition, a connection member having high resolution and excellent connection reliability can be provided.

  The present invention will be described with reference to the drawings. FIG. 1 is a schematic cross-sectional view of a connecting member for explaining an embodiment of the present invention. The connection member used in the present invention is a multilayer connection member in which an insulating adhesive layer 2 is formed on at least one surface of a conductive adhesive layer 1 having conductivity in a pressurizing direction composed of a conductive material and a binder. As shown in FIG. 2, the insulating adhesive layer 2 may be formed on both surfaces of the conductive adhesive layer 1. Although not shown in FIGS. 1-2, you may add functions, such as adhesiveness, to the insulating contact bonding layer 2 as a multilayer structure further. In order to prevent unnecessary adhesion such as stickiness and dust from being present on these surfaces, there can be a separator 5 that can be peeled off as shown in FIG. Although not shown, the separator 5 can be formed on both sides. In the case of FIG. 1, since the separator 5 is in contact with the insulating adhesive layer 2, when the substrate on one side is a flat electrode (for example, a display substrate such as a liquid crystal), the separator 5 does not exist on the flat electrode side. Since the conductive adhesive layer 1 can be formed, the workability is good and convenient. In these cases, the continuous tape shape is preferable because continuous automation of the connection work process can be achieved.

  FIG. 3 is a schematic cross-sectional view illustrating the conductive adhesive layer 1 having conductivity in the pressing direction. The conductive adhesive layer 1 is made of a binder 4 containing a conductive material 3. Here, as the conductive material 4, those shown in FIGS. 3A to 3G are applicable. Among these, the conductive material 3 has a particle size that can exist in a single layer in the thickness direction of the binder 5 as shown in FIGS. 3C to 3E, that is, a particle size substantially equal to the thickness of the binder 5. Since the conductive material 3 does not easily flow at the time of connection, the conductive material 3 is preferable to be easily held on the electrode. When the conductive material 3 is substantially equal to the thickness of the binder 4, it is possible to conduct electricity with the electrode by simple contact, and conductivity is easily obtained. The ratio of the conductive material 3 to the binder 4 is preferably about 0.1 to 20% by volume, and more preferably 1 to 15% by volume, because anisotropic conductivity is easily obtained. Further, in order to easily obtain conductivity in the thickness direction and to achieve high resolution, the thickness of the binder 5 is preferably as thin as possible within the range where a film can be formed, and is 20 μm or less, more preferably 10 μm or less. For example, the conductive material 3 is preferably formed of conductive particles as illustrated in FIGS. 3A to 3E because the manufacturing is relatively easy. Further, the conductive material 3 may be provided with a through hole in the binder 5 as shown in FIG. 3 (f) to form a conductor by plating or the like, or may be in the form of a conductive fiber such as a wire as shown in FIG. 3 (g). .

  Examples of the conductive particles include metal particles such as Au, Ag, Pt, Ni, Cu, W, Sb, Sn, and solder, carbon, and the like. These conductive particles are used as a core material, or non-conductive glass, A core material made of a polymer such as ceramics or plastic may be coated with a conductive layer made of the above-described material. Furthermore, insulating coating particles formed by coating the conductive material 6 with an insulating layer, and combined use of conductive particles and insulating particles such as glass, ceramics, and plastics are applicable because the resolution is improved. In order to secure one or more particles, preferably as many particles as possible, on the minute electrode, the particle size is preferably 15 μm or less, more preferably 7 μm or less, and 1 μm or more. If it is 1 μm or less, it is difficult to break through the insulating adhesive layer and contact the electrode. In addition, it is preferable that the conductive material 3 has a uniform particle diameter because there is little outflow from between the electrodes. Among these conductive particles, those in which a conductive layer is formed on a polymer core material such as plastic, and hot-melt metal such as solder are deformable by heating or pressurization, and contact with a circuit for connection This is preferable because the area is increased and the reliability is improved. In particular, when a polymer is used as a nucleus, it does not show a melting point like solder, so that the softening state can be widely controlled by the connection temperature, and it is easy to cope with variations in electrode thickness and flatness, which is particularly preferable. Also, for example, in the case of hard metal particles such as Ni and W, or particles having a large number of protrusions on the surface, the conductive particles pierce the electrode and the wiring pattern, so that even when an oxide film or a contaminated layer exists, a low connection resistance is obtained. It is preferable because it is obtained and reliability is improved.

  For the binder 4 and the insulating adhesive layer 2, a material exhibiting curability by heat or light can be widely applied, and it is preferable that the adhesive is high. Since these are excellent in heat resistance and moisture resistance after connection, application of a curable material is preferable. Among these, an epoxy adhesive is particularly preferable because it can be cured for a short time, has good connection workability, and has excellent molecular adhesion. Epoxy adhesives are mainly composed of epoxy modified with high molecular weight epoxy, solid epoxy and liquid epoxy, urethane, polyester, acrylic rubber, NBR, silicone, nylon, etc., curing agent, catalyst, coupling agent, filling A material obtained by adding an agent or the like is generally used. When the binder component 4 and the insulating adhesive layer 2 contain a common material in each component in an amount of 1% by weight or more, preferably 5% by weight or more, the interfacial adhesive force between the two layers is improved. As the common material, a main material, a curing agent, and the like are more effective.

  The melt viscosity at the time of connection of the binder component used in the present invention is equal to or less than that of the insulating adhesive layer. This point will be described with reference to FIGS. FIG. 4 is a schematic explanatory diagram showing the melt viscosity during heating of the binder component 4 and the insulating adhesive layer 2. Under the temperature at the time of connection, the binder component 4 (A) is relatively equal to or less than that of the insulating adhesive layer 2 (B). Preferably, the difference in viscosity between (A) and (B) at this time is 0. It is about 1 to 1000 poise, more preferably 1 to 200 poise. If the difference in viscosity is too large, the contact between the electrode and the particles tends to be insufficient. As will be described later with reference to FIG. 5, there is a preferable viscosity range in order to hold the particles on the electrode from the balance between the contact at the time of connection and the flow process, and to effectively obtain the contact between the electrode and the particle. For the same reason, the melt viscosity at the time of connection is preferably such that the binder component is 500 poise or less, and at this time, the insulating adhesive layer is more preferably 1000 poise or less.

  In the contact process shown in FIG. 5A, first, the conductive material 3 is embedded in the insulating adhesive layer 2 having a relatively equal or higher melt viscosity, or a part of the conductive material 3 is captured. The position is maintained. Next, in the flow process of FIG. 5B, the conductive material 3 comes into contact with the protruding electrode 12 by the softening of the insulating adhesive layer, and can conduct electricity with the planar electrode 13. In the case of a preferred embodiment in which the melt viscosity at the time of binder component connection is lower than that of the insulating adhesive layer, the insulating adhesive layer 2 can hold the conductive material 3 and the spaces between adjacent protruding electrodes are bubbles. It can be connected in the state without. In this case, in order to promote softening of the insulating adhesive layer 2, the insulating adhesive layer of the connecting member is disposed on the protruding electrode side, a heat source is disposed on the insulating adhesive layer side, and heating and pressing are further performed. preferable. At this time, it is also possible to divide the heating and pressurizing process into two or more stages and to make an electrode connection method including an energization inspection process and / or a repair process as necessary. By decomposing the heating and pressurizing step into two or more steps, it is possible to control the viscosity of the flow process associated with the curing reaction of the adhesive, and therefore, a good connection without bubbles is possible. In addition, it is possible to impart repairability, which is a problem with curable adhesives.

  The energization inspection step can be performed while increasing the cohesive force of the connection member to the extent that the connection electrode can be held, or while pressurizing the electrode connection portion. The energization inspection can be performed, for example, by taking out lead wires from both electrodes and measuring the connection resistance. At this time, the appearance inspection of the contact state between the conductive material 3 and the electrode can also be performed together or independently. Repairability is to remove unnecessary part of the adhesive, clean it with a solvent, and reconnect. In general, a curable adhesive has been regarded as a problem because a network structure develops after curing, becomes insoluble and infusible with heat, solvent, and the like, and is extremely difficult to clean. In the first stage of the heating and pressurizing process, for example, the conductive material 3 is in contact with the protruding electrode 12, and an energization inspection of both electrodes is performed in a state where the conductive material 3 can conduct with the flat electrode 13. At this time, if there is a connection portion of a defective electrode, repair and reconnection are performed in this state. Since the adhesive is uncured or has an insufficient curing reaction, it is easy to peel off and soak in a solvent, and repair work is easy.

  The method for measuring the melt viscosity is not particularly limited as long as the binder component 4 and the insulating adhesive layer 2 can be relatively compared with each other. However, it is preferable to use the same method. A simple rotary viscometer can be used. At this time, in the case of, for example, thermosetting blending in which the reaction proceeds at the time of measurement and the viscosity changes, the measured value in the model blending with the curing agent removed can be adopted. As a method of providing a difference in melt viscosity at the time of connection between the binder component 4 and the insulating adhesive layer 2, a combination of the intrinsic viscosity depending on the molecular weight of the material and the entanglement of the molecules, selection of a filler as a thickener, and curing Control of the reaction rate in the system is common. As a method for producing the connection portion material, for example, a method of laminating the conductive adhesive layer 1 and the insulating adhesive layer 2 or laminating and sequentially applying the layers can be employed.

  An electrode connection structure using a connection member and a manufacturing method thereof will be described with reference to FIGS. FIG. 6 shows a structure in which the protruding electrode 12 formed on the substrate 11 and the planar electrode 13 of the substrate 11 ′ are connected via a connecting member. That is, it is a connection structure between electrode rows in which at least one of the oppositely facing electrode rows protrudes, the conductive material 3 exists between the oppositely facing electrodes 12-13, and from the periphery 14 of the protruding electrode 12 Also, the conductive material exists in a high density state, and the electrode rows facing each other are connected. The insulating adhesive layer 2 covers at least the protruding electrode 12 of the protruding electrode 12. Here, the planar electrode 13 refers to a case where there is no unevenness from the surface of the substrate 11 or even a few μm or less. When these are illustrated, the electrodes obtained by the additive method and the thin film method are typical.

  FIG. 7 shows a case where the electrodes formed on the substrate are the protruding electrodes 12 and 12 ′. That is, it is a structure in which both surfaces shown in FIG. 2 are connected via a connecting member having insulating adhesive layers 2 and 2 ′. The insulating adhesive layers 2 and 2 ′ cover the periphery of the protruding electrodes of the protruding electrodes 12 and 12 ′, respectively, and are in contact with the substrate surfaces 11 and 11 ′. 6 to 7, the conductive adhesive layer 1 and the insulating adhesive layer 2 form a boundary. However, they may be mixed, and from the top 16 of the protruding electrode 12 to the substrate 11 side as shown in FIG. 8. A configuration in which the density of the conductive material 3 is gradually reduced may be employed. 6 to 7, examples of the substrate 11 include plastic films such as polyimide and polyester, composites such as glass fiber / epoxy, semiconductors such as silicone, inorganic materials such as glass and ceramics, and the like. The protruding electrode 12 can include various circuits and terminals in addition to the above. The various electrodes shown in FIGS. 6 to 7 can be applied in any combination. The electrode connecting method using the connecting member of the present invention is arranged so that the insulating adhesive layer 2 of the connecting member is on the protruding electrode 12 side, and the melt viscosity at the time of connecting the binder component and the insulating adhesive layer. However, it is heated and pressurized under a condition in which the binder component is relatively lower than the insulating adhesive layer.

  Since the melt viscosity when connecting the binder component is equal to or less than that of the insulating adhesive layer, the conductive material 3 of the conductive adhesive layer 1 is relatively equal to or higher than the melt viscosity when connecting the electrodes. The conductive material 3 is held on the protruding electrode 12 by being embedded in 2 or in a state of being partially captured. Next, due to the softening flow of the insulating adhesive layer, the conductive material 3 comes into contact with the protruding electrodes 12 and becomes conductive. At this time, the insulating adhesive layer 2 has a higher viscosity than the binder component 4, can hold the conductive material 3, and can connect the spaces between adjacent protruding electrodes without bubbles.

  Since the conductive material 3 is securely held on the electrode 12 and becomes conductive, the reliability of the continuity test is improved. Since the adhesive can be inspected for continuity in an uncured state or in an insufficient curing reaction, the repair work is easy. Since the insulating adhesive layer 2 is disposed so as to be on the protruding electrode 12 side, the insulation and resolution between adjacent electrodes are improved. In addition, when the insulating adhesive layer 2 has a high melt viscosity, the connection pressure is not applied, so that the conductive material 3 is less likely to flow between adjacent electrodes. Since the conductive material 3 of the conductive adhesive layer 1 is uniformly dispersed over the entire surface, it is excellent in workability because accurate alignment between the conductive particles and the electrodes is unnecessary. Depending on the purpose of the adhesive layer, for example, a combination that exhibits adhesion suitable for the material of the electrode substrate is possible, so that the choice of materials is expanded, and the connection reliability is also improved due to the reduction of bubbles in the connection portion. Further, by making one of them soluble or swellable in a solvent or having a difference in heat resistance, it is possible to preferentially peel off from one substrate surface and to impart so-called repairability for reconnection. Alternatively, any combination suitable for the material of the electrode substrate is possible, and it is easy to obtain contact between the electrode and the conductive particles, and the manufacturing method is also simple. Further, it is possible to obtain a reinforcing or moisture-proof effect by causing the adhesive layer to protrude outside the connecting portion and acting as a sealing material.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited thereto.
Example 1
(1) Production of conductive adhesive layer The weight ratio of liquid epoxy resin (epoxy equivalent 185) containing phenoxy resin (high molecular weight epoxy resin) and microcapsule type latent curing agent is 30/70, and 30 weight of ethyl acetate % Solution was obtained. To this solution, 5% by volume of conductive particles in which a Ni / Au metal coating with a thickness of 0.2 / 0.02 μm was added to polystyrene particles having a particle size of 5 ± 0.2 μm was added and mixed and dispersed. This dispersion was applied to a separator (silicone-treated polyethylene terephthalate film, thickness 40 μm) with a roll coater and dried at 110 ° C. for 20 minutes to obtain a conductive adhesive layer having a thickness of 5 μm. The viscosity of the model blend from which the curing agent of the adhesive layer was removed was measured with a digital viscometer HV-8 (manufactured by Reska Co., Ltd.). The viscosity at 150 ° C. was 80 poise.

(2) Formation of insulating adhesive layer and preparation of connecting member The mixing ratio of (1) was set to 40/60, the conductive particles were removed from the conductive adhesive layer, and a sheet having a thickness of 15 μm was prepared in the same manner as (1). . First, the conductive adhesive layer surface (1) and the adhesive layer surface (2) were laminated while being rolled between rubber rolls. Thus, the multilayer connection member having the two-layer structure shown in FIG. 1 was obtained. The viscosity at 150 ° C. measured in the same manner as described above was 280 poise. Therefore, the difference in viscosity between the conductive adhesive layer and the insulating adhesive layer at 150 ° C. is 200 poise.

(3) Connection Two-layer FPC circuit board (circuit pitch is 70 μm, electrode of parallel circuit with electrode width of 20 μm) having a copper circuit with a height of 18 μm on a polyimide film, and an indium oxide thickness of 0 on glass 1.1 mm Connection with a planar electrode having a thin film circuit of 2 μm (ITO, surface resistance 20Ω / □) was made. At this time, the heat source of the connection device was disposed on the insulating adhesive layer side. First, the conductive adhesive layer was placed on the planar electrode side. The connecting member was placed with a width of 2 mm, and the separator was peeled off and pasted. Since it was temporarily connected to the flat electrode side, it was easy to attach, and the subsequent separation of the separator was also easy. Next, the other circuit board and the upper and lower circuits were aligned, and a connection body was obtained at 150 ° C., 20 kgf / mm ² , and 15 seconds.

(4) Evaluation When the cross section of this connection body was polished and observed with a microscope, it was a connection structure corresponding to FIG. The space between adjacent electrodes was free of bubbles and the particles were spherical, but the particles were compressed and deformed on the electrodes and held in contact with the upper and lower electrodes. When the resistance between the electrodes facing each other was evaluated as the connection resistance, and between the adjacent electrodes as the insulation resistance, the connection resistance was 1Ω or less and the insulation resistance was 10 ⁸ Ω or more, which changed even after treatment at 85 ° C. and 85% RH for 1000 hours. No long-term reliability was observed. The number of effective average particles contributing to the connection on the electrode (20 μm × 2 mm) in this example was 60 (maximum 66 particles, minimum 52 particles). The effective particles contributing to the connection were observed by observing the connection surface from the glass side with a microscope (× 100) and having gloss due to contact with the electrode.

Comparative Example 1
Although it was the same as that of Example 1, a single-layer conductive adhesive layer having a conventional structure with a thickness of 20 μm was obtained. When evaluated in the same manner as in Example 1, the number of particles on the electrode (20 μm × 2 mm) was 38 at the maximum and 0 at the minimum, and there was no effective particle on the electrode. And the smallest variation was large. Further, when the insulation resistance of the connection body was measured, a short circuit defect occurred. It seems that the conductive particles flowed out from the electrodes at the time of connection, and the insulation between adjacent electrodes (space portions) cannot be maintained.

Example 2
Similarly, an insulating adhesive layer was formed on the other surface of the conductive adhesive layer of Example 1 to obtain a multi-layer connecting member having a three-layer structure shown in FIG. Connections were made in the same manner as the FPC of Example 1 to obtain a connection body corresponding to FIG. When evaluated in the same manner as in Example 1, good connection characteristics were shown. The number of effective particles on the electrodes can be secured to 10 or more in all the electrodes regardless of the configuration in which the particles easily flow out because of the connection between the protruding electrodes.

Examples 3-5
Although it is the same as that of Example 1, the difference in the viscosity at 150 ° C. of both layers was changed by changing the blending ratio of the phenoxy resin and the liquid epoxy resin of the insulating adhesive layer. The results are shown in Table 1 together with Example 1 described above. In each example, the number of effective particles on the electrode was large and the variation was relatively small, and good connection characteristics were exhibited as in Example 1.

Example 6
Same as Example 1, but instead of FPC, an IC chip (2 × 10 mm, height 0.5 mm, 200 gold electrodes of 50 μm square and 20 μm height called bumps are formed around 4 sides) is used. It was. The ITO electrode on the glass side was changed to correspond to the size of the bump electrode of the IC chip. The connection body has a configuration substantially corresponding to that shown in FIG. 6, but showed good connection characteristics. In this example, the particles were compressed and deformed and held in contact with the upper and lower electrodes even though the bumps were mushroom-shaped and had tops. Air bubbles were not mixed between adjacent bumps, and good long-term reliability was demonstrated. As for the conductive particles, the degree of deformation of the particles differs depending on the distance between the opposing electrodes, and some of the conductive particles bite into the bumps. The number of effective particles on the pump could be 5 or more for all electrodes.

Examples 7-8
Although it is the same as that of Example 6, it changed into the board | substrate which can mount five IC chips on a glass substrate, and made the heating-pressing process into two steps. First, the connection resistance at each connection point was measured and inspected with a multimeter while applying pressure after 150 seconds at 20 ° C. and 20 kgf / mm ² (Example 7). Similar but the other was removed from the connecting device after 150 seconds at 20 ° C. and 20 kgf / mm ² . Since the cohesive force of the adhesive was improved by heating and pressing, each IC chip could be temporarily fixed on the glass side and similarly tested without pressure (Example 8). In both examples, one IC chip was abnormal. Then, when the abnormal chip was peeled off and the same connection as described above was performed with a new chip, both were good this time. Since the adhesive is in a state where the curing reaction is insufficient, the chip peeling and the subsequent cleaning with acetone are very simple, and the repair work is easy. After the above energization inspection process and repair process, when connected at 150 ° C., 20 kgf / mm ² for 15 seconds, both examples showed good connection characteristics. The number of effective particles on the bumps could be secured to 7 or more for all electrodes. In the present embodiment, the number of effective particles on the bumps is increased and the outflow from the electrodes is less than in the sixth embodiment. It is considered that the retention property of the particles is further improved by making the heating and pressing step into two stages.

Example 9
Although it is the same as that of the connection member of Example 2, the thickness of the adhesive layer was formed to 25 μm on one side and the other surface to 50 μm. The electrodes were QFP type IC leads (thickness: 100 μm, pitch: 300 μm), and were connected to terminals of copper on a glass epoxy substrate having a thickness of 35 μm. This configuration is similar to that shown in FIG. 7, but has no substrate on the lead side (one side) of the IC. In this example, the electrodes were connected to each other with a large height, but there was no electrode displacement and good connection characteristics were shown. Although the conductive material in the conductive sheet is not shown, the particles were compressed and deformed and held in contact with the upper and lower electrodes. Air bubbles were not mixed between adjacent electrodes, and good long-term reliability was demonstrated. In this example, the adhesive layer was formed along the lead height even in the portion without the substrate, and the lead could be fixed. The number of effective particles on the electrode could be 10 or more for all electrodes.

Example 10
Although it is the same as that of the connecting member of Example 1, the conductive particles are changed to carbonyl nickel having an unevenness on the surface (average particle size 3 μm), and the insulating adhesive layer is made of carboxyl-modified SEBS (styrene-ethylene-butylene-styrene block co-polymer). The ratio of the polymer) to the liquid epoxy resin (epoxy equivalent 185) containing the microcapsule type latent curing agent was 20/80, and a sheet having a thickness of 15 μm was prepared in the same manner as described above, and laminated with the conductive adhesive layer surface. The viscosity at 150 ° C. measured in the same manner as described above was 100 poise. Therefore, the difference in viscosity between the conductive adhesive layer and the insulating adhesive layer is 20 poise. As a result of evaluation in the same manner as in Example 1, the tip of the conductive particles bite into the electrode, and the number of effective particles on the electrode was 100 or more. Good connection resistance, insulation resistance, and long-term reliability. In this example, since the polymer component was changed between the conductive adhesive layer and the insulating adhesive layer, it could be cleanly peeled off from the surface on the insulating adhesive layer side after bonding. This means the ease of repair work. The Tg (glass transition point) determined by the TMA (thermomechanical analysis) tensile method between the conductive adhesive layer and the insulating adhesive layer was 125 ° C. for the former and 100 ° C. for the latter. This is effective when the peeling temperature is set to a high temperature during repair work and peeling is performed using the difference in heat resistance.

Examples 11-13
Same as the connection member of Example 1, but 1% by volume of polystyrene particles which are the cores of the conductive particles of Example 1 as insulating particles, a conductive adhesive layer (Example 11), and an insulating adhesive layer (implemented) Example 12) and both layers (Example 13) were mixed and dispersed. When evaluated in the same manner as in Example 1, the connection resistance, insulation resistance, and long-term reliability were all good. Since the addition amount of the insulating particles was small, no influence on the fluidity was observed in each example. In Example 11, the insulating particles were dispersed between the conductive particles, which was effective in improving the resolution of the anisotropic conductivity of only the conductive adhesive layer. Example 12 was effective in maintaining the insulating property of the insulating adhesive layer, and Example 13 had the characteristics of both Examples 11-12. The insulating particles of Examples 11 and 13 were deformed and held between the electrodes in the same manner as the conductive particles.

Example 14
Although it is the same as that of the connection member of Example 1, the surface of the conductive particles was subjected to an insulation coating treatment. That is, the surface of conductive particles having an average particle diameter of 5 μm was coated with a nylon resin having a glass transition point of 127 ° C. to a thickness of about 0.2 μm, and the amount added was increased to 10% by volume. Evaluation was performed in the same manner as in Example 1, but good connection characteristics were exhibited. In this example, the number of particles on the electrode increased significantly. The electrode connection can be conducted by softening the insulating layer and binder due to the thermal pressure at the time of connection, but the space part of the adjacent electrode row has little heat pressure and the surface of the conductive material is still covered with the insulating layer. The property was also good. The number of effective particles on the bumps could be 20 or more for all electrodes. In this structure, the density | concentration with respect to the binder of an electroconductive material was able to be comprised with high density.

The cross-sectional schematic diagram which shows the connection member of this invention. The cross-sectional schematic diagram which shows the other connection member of this invention. The cross-sectional schematic diagram which shows the electroconductive contact bonding layer in this invention. The diagram which shows the melt viscosity of the adhesive bond layer in this invention. Explanatory drawing (a) (b) which shows the connection process in this invention. The cross-sectional schematic diagram which shows the example of a connection structure of the electrode using the connection member of this invention. The cross-sectional schematic diagram which shows the example of a connection structure of the electrode using the connection member of this invention. The cross-sectional schematic diagram which shows the example of a connection structure of the electrode using the connection member of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Conductive adhesive layer 2 Insulating adhesive layer 3 Conductive material 4 Binder 5 Separator 11 Substrate 12 Protruding electrode 13 Planar electrode 14 Perimeter 15 Cavity 16 Top

Claims (3)

A curable insulating adhesive layer is formed on one side of a conductive adhesive layer having conductivity in a pressurizing direction composed of a conductive material and a binder, and a peelable separator is in contact with the curable insulating adhesive layer. An electrode connection method using a circuit connection member,
The melt viscosity at the time of heat connection of the binder component is 500 poise or less, and the melt viscosity at the time of heat connection of the binder component is equal to or less than the melt viscosity at the time of heat connection of the curable insulating adhesive layer. The difference between 0 and 1000 poise,
Between the protruding electrode formed on one substrate and the electrode array where the planar electrode formed on the other substrate faces each other, the circuit connecting member is disposed between the conductive adhesive layer and the planar electrode side. The electrode connecting method, wherein the electrode layer is placed so that the conductive adhesive layer is temporarily attached to the planar electrode side, the separator is peeled off, and the curable insulating adhesive layer is attached to the protruding electrode side.   The electrode connection method according to claim 1, wherein the planar electrode has an unevenness of 0.2 μm or less from the substrate.   The electrode connection method according to claim 1, wherein a heat source is disposed on the insulating adhesive layer side and heated and pressurized.

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