JP2011165879A - Method for connection between terminals - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for connection between opposite terminals, capable of obtaining good electrical connection between the terminals and high insulation reliability between adjacent terminals. <P>SOLUTION: The connection method includes: an arrangement step of disposing a conductive connection material 100 between the opposite terminals 11 and 21 by using the conductive connection material 100 having a laminate structure comprising a resin composition 120 and a metal foil 110 selected from a solder foil and a tin foil; an adjustment step of heating the conductive connection material 100 at a temperature lower than the melting point of the metal foil 110 and controlling the shortest separation x between the opposite terminals 11 and 21 within a predetermined range; a heating step of heating the conductive connection material 100 not to allow the resin composition 120 to be completely cured at a temperature of the melting point of the metal foil 110 or higher while keeping the shortest separation x within the predetermined range; and a curing step of curing the resin composition 120 at a temperature lower than the melting point of the metal foil 110. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for electrically connecting electronic members in electrical and electronic components, and to a method for electrically connecting opposing terminals.

  In recent years, with the demand for higher functionality and miniaturization of electronic devices, the pitch between connection terminals in electronic materials is becoming increasingly narrow. Along with this, the connection between terminals in a fine wiring circuit has also been advanced. As a connection method between terminals, for example, flip chip connection in which a large number of terminals are connected together using an anisotropic conductive adhesive or an anisotropic conductive film when an IC chip is electrically connected to a circuit board. Technology is known. An anisotropic conductive adhesive or anisotropic conductive film is a film or paste in which conductive particles are dispersed in an adhesive mainly composed of a thermosetting resin (for example, JP-A-61-276873). Patent Document 1) and Japanese Patent Application Laid-Open No. 2004-260131 (Patent Document 2)). By arranging this between the electronic members to be connected and thermocompression bonding, a large number of opposing terminals can be connected together, and insulation between adjacent terminals is ensured by the resin in the adhesive. Make it possible.

  However, it is difficult to control the aggregation of the conductive particles. (1) The conductive particles and the terminals, or the conductive particles are not sufficiently in contact with each other, and a part between the facing terminals is not conductive, 2) In some cases, the conductive particles remain in the resin (insulating region) other than between the opposing terminals (conducting region) to generate a leakage current, and insulation between adjacent terminals cannot be sufficiently ensured. For this reason, it is difficult for conventional anisotropic conductive adhesives and anisotropic conductive films to cope with further narrow pitches between terminals.

JP-A 61-276873 JP 2004-260131 A

  Under such circumstances, provision of a method for electrically connecting terminals that makes it possible to obtain good electrical connection between connecting terminals and high insulation reliability between adjacent terminals is demanded. There is also a need to provide a method for simply connecting such terminals.

  In order to solve the above-mentioned problems, the present inventors diligently studied, and as a result of using solder foil or tin foil instead of conductive particles in the conductive connection material, aggregation between terminals of solder or tin is facilitated, It has been found that solder or tin can be suppressed from remaining in the resin. Furthermore, the inventor heats the conductive connecting material at a temperature lower than the melting point of the metal foil before melting the metal foil to reduce the viscosity of the resin composition, and adjusts the gap between the terminals in a predetermined range in advance. Then, by melting the metal foil, it was found that the behavior of the resin and the molten metal can be controlled, and the electrical connection between the terminals can be made more reliable, thereby completing the present invention.

That is, this invention provides the connection method between the terminals using the conductive connection material shown below.
[1] A method of electrically connecting opposing terminals using a conductive connection material having a laminated structure composed of a resin composition and a metal foil selected from solder foil or tin foil,
An arrangement step of arranging the conductive connection material between opposing terminals;
An adjustment step of heating the conductive connection material at a temperature lower than the melting point of the metal foil, and adjusting the shortest separation distance between opposing terminals to a predetermined range;
A heating step of heating the conductive connecting material so that the curing of the resin composition is not completed at a temperature equal to or higher than the melting point of the metal foil while maintaining the shortest separation distance in the predetermined range;
Curing the resin composition at a temperature lower than the melting point of the metal foil.
[2] The method according to [1], wherein, in the adjusting step, the shortest separation distance between the opposing terminals is adjusted to a range larger than the thickness of the metal foil and smaller than the thickness of the conductive connection material.
[3] The method according to [1], wherein, in the adjustment step, the shortest separation distance between the opposing terminals is adjusted to a range that is equal to or less than a thickness of the metal foil and that the opposing terminals do not contact each other.
[4] In any one of [1] to [3], in the heating step, the metal foil is melted and the molten metal is aggregated between opposing terminals to electrically connect the opposing terminals. The method described.
[5] The method according to [4], wherein terminals facing each other are electrically connected by metal bonding between the molten metal and the terminals.
[6] The adjustment step according to any one of [1] to [5], wherein in the adjustment step, the shortest separation distance between the opposing terminals is adjusted to a range smaller than the shortest separation distance between adjacent terminals. Method.
[7] The method according to any one of [1] to [6], wherein the melt viscosity of the resin composition in the adjustment step is 0.1 Pa · s to 10,000 Pa · s.
[8] The method according to any one of [1] to [7], wherein the melt viscosity of the resin composition in the heating step is 0.01 Pa · s to 100 Pa · s.
[9] The method according to any one of [1] to [8], wherein the melting point of the metal foil is 100 ° C to 330 ° C.
[10] The method according to any one of [1] to [7], wherein the heating temperature of the conductive connecting material in the adjusting step is 60 ° C to 200 ° C.
[11] The method according to any one of [1] to [10], wherein the heating temperature of the conductive connecting material in the heating step is less than 50 ° C. higher than the melting point of the metal foil.
[12] The method according to any one of [1] to [8], wherein the heating temperature of the conductive connecting material in the heating step is 140 ° C to 340 ° C.
[13] The method according to any one of [1] to [12], wherein the heating temperature of the conductive connecting material in the curing step is 80 ° C to 310 ° C.
[14] The method according to any one of [1] to [13], wherein the conductive connection material includes a laminated structure including a resin composition layer / metal foil layer / resin composition layer.
[15] The method according to any one of [1] to [13], wherein the conductive connection material includes a laminated structure composed of a resin composition layer / metal foil layer.
[16] The method according to any one of [1] to [15], wherein the resin composition contains an epoxy resin, a curing agent, and a compound having a phenolic hydroxyl group and / or a carboxyl group.
[17] The method according to [16], wherein the resin composition further comprises a film-forming resin selected from the group consisting of a phenoxy resin, a (meth) acrylic resin, and a polyimide resin.
[18] The resin composition comprises 10 to 90% by weight of an epoxy resin, 0.1 to 50% by weight of a curing agent, 5 to 50% by weight of a film-forming resin, a phenolic hydroxyl group and The method according to any one of [1] to [17], which comprises 1 to 50% by weight of a compound having a carboxyl group.
[19] The method according to any one of [16] to [18], wherein the compound having a phenolic hydroxyl group and / or a carboxyl group includes a compound represented by the following general formula (1).
_{HOOC- (CH 2) n-COOH} (1)
[In formula, n is an integer of 1-20. ]
[20] The any one of [16] to [19], wherein the compound having a phenolic hydroxyl group and / or a carboxyl group includes a compound represented by the following general formula (2) and / or (3). the method of.
[Wherein, R ^{1 to} R ⁵ are each independently a monovalent organic group, provided that at least one of R ^{1 to} R ⁵ is a hydroxyl group. ]
[Wherein, R ^{6 to} R ²⁰ are each independently a monovalent organic group, provided that at least one of R ^{6 to} R ²⁰ is a hydroxyl group or a carboxyl group. ]

According to the present invention, by using a metal foil, melted solder or tin is likely to aggregate, and it is possible to suppress the metal from remaining in the resin, thereby obtaining good electrical connection and high insulation reliability. Can do.
Further, according to the present invention, since the conductive connecting material is heated stepwise, the moving distance of the molten solder or tin in the resin composition can be minimized, so that the resin and the molten metal can be formed in a desired region. It becomes easier to agglomerate. According to the preferable aspect of the present invention, since the conductive region can be formed between the terminals facing each other more efficiently, the usage amount of the metal foil can be determined according to the purpose and application.
According to the present invention, since electrical connection between terminals can be more reliably performed, a large number of terminals in a fine wiring circuit such as a semiconductor device can be collectively connected.

It is a general | schematic process drawing for demonstrating the preferable embodiment of this invention. It is a general | schematic process drawing for demonstrating the preferable embodiment of this invention. It is a plane schematic diagram which shows an example of the shape of the metal foil layer used for this invention.

  Hereinafter, the method for electrically connecting the terminals of the present invention will be specifically described.

The method for electrically connecting the terminals of the present invention (hereinafter also referred to as “the connection method of the present invention”) is a conductive structure having a laminated structure composed of a resin composition and a metal foil selected from solder foil or tin foil. A method of electrically connecting opposing terminals using a connecting material,
An arrangement step of arranging the conductive connection material between opposing terminals;
An adjustment step of heating the conductive connection material at a temperature lower than the melting point of the metal foil, and adjusting the shortest separation distance between opposing terminals to a predetermined range;
A heating step of heating the conductive connecting material so that the curing of the resin composition is not completed at a temperature equal to or higher than the melting point of the metal foil while maintaining the shortest separation distance in the predetermined range;
A curing step of curing the resin composition at a temperature lower than the melting point of the metal foil.

In the connection method of the present invention, the metal component in the conductive connection material is used in the form of a metal foil. As a result, when the metal foil is melted, the molten metal is easily aggregated, and electrical connection between the terminals can be more reliably performed. In addition, since the molten metal is likely to aggregate, it is difficult for the metal to remain in the resin, and insulation between adjacent terminals can be ensured to prevent the occurrence of leakage current.
Furthermore, in the connection method of the present invention, the conductive connection material is heated stepwise while controlling the heating temperature in the adjustment step and the heating step. Specifically, in the connection method of the present invention, first, the conductive connection material is heated at a temperature lower than the melting point of the metal foil, thereby reducing the viscosity of the resin composition without dissolving the metal foil, and the gap between the terminals. Is adjusted to a predetermined range, and then the conductive foil is heated at a temperature equal to or higher than the melting point of the metal foil so that the curing of the resin composition is not completed, thereby melting the metal foil. In this way, the metal foil is melted after adjusting the gap between the terminals in a predetermined range in advance, so that the moving distance of the molten metal in the resin composition can be minimized, and the resin can be placed in a desired region. In addition, the molten metal can be more easily aggregated.

  In the connection method of the present invention, for example, in the adjustment step, the shortest separation distance between opposing terminals is adjusted to a range larger than the thickness of the metal foil and smaller than the thickness of the conductive connection material (first embodiment). And a method (second embodiment) in which the shortest separation distance between the opposing terminals is adjusted to a range that is equal to or smaller than the thickness of the metal foil and that the opposing terminals do not contact each other. Hereinafter, preferred embodiments of the present invention will be specifically described with reference to the drawings, but the present invention is not limited to these drawings.

1. First Embodiment First, a first embodiment of the present invention will be described with reference to FIG. In the first embodiment of the present invention, the disposing step of disposing the conductive connecting material between the opposing terminals, heating the conductive connecting material at a temperature lower than the melting point of the metal foil, and reducing the shortest separation distance between the opposing terminals. An adjustment step for adjusting to a predetermined range, and the conductive connecting material so as not to complete the curing of the resin composition at a temperature equal to or higher than the melting point of the metal foil while maintaining the shortest separation distance in the predetermined range. It is a connection method between terminals including a heating step of heating and a curing step of curing the resin composition at a temperature lower than the melting point of the metal foil, and in the adjustment step, the shortest separation distance between opposing terminals is In this method, the thickness is adjusted to be larger than the thickness of the metal foil and smaller than the thickness of the conductive connection material. Hereinafter, each step will be described.

(A) Arrangement Step In the arrangement step, as shown in FIG. 1A, the substrate 10 provided with the terminal 11 and the substrate 20 provided with the terminal 21 are arranged so that the terminal 11 and the terminal 21 face each other. The conductive connecting material 100 including the metal foil 110 and the resin composition 120 provided on both surfaces of the metal foil is disposed between the terminals. At this time, the conductive connection material 100 may be thermocompression bonded in advance to the substrate 10 or one side of the substrate 20 or both of the substrate 10 and the substrate 20 using an apparatus such as a roll laminator or a press. Further, the surfaces of the terminals 11 and 21 may be subjected to treatments such as washing, polishing, plating, and surface activation as necessary in order to improve electrical connection.

(B) Adjustment step In the adjustment step, the conductive connection material is heated at a temperature lower than the melting point of the metal foil, and the shortest separation distance between the opposing terminals is adjusted to a predetermined range. The term “shortest distance” is used in “the shortest separation distance between opposing terminals” to express the closest separation distance when the distance between the terminals is not constant.

  In the adjustment step, the conductive connecting material 100 is heated at a temperature lower than the melting point of the metal foil 110, so that the resin composition 120 is softened to a deformable level, and the shortest separation distance between the opposing terminals is within a predetermined range. adjust. In the first embodiment of the present invention, the shortest separation distance x between the opposing terminals is adjusted to a range larger than the thickness of the metal foil 110 and smaller than the thickness of the conductive connection material 100 (see FIG. 1B). .

  In this step, the heating temperature is controlled to be lower than the melting point of the metal foil, the resin composition 120 is deformed without melting the metal foil, and the separation distance x between the facing terminals is adjusted, so that the desired region is obtained. It becomes easy to aggregate the resin and the molten metal. According to the preferred embodiment of the present invention, the molten metal can be more reliably agglomerated in a desired region, so that it is possible to design in advance the amount of metal foil necessary and sufficient for electrical connection between opposing terminals. it can. In addition, it is preferable to adjust the shortest separation distance between the terminals which oppose in the range smaller than the shortest separation distance between adjacent terminals. By adjusting the shortest separation distance between the facing terminals to a range smaller than the shortest separation distance between the adjacent terminals, the molten metal is more easily aggregated between the facing terminals. In the “shortest separation distance between adjacent terminals”, the term “shortest” is used to express the closest separation distance when the distance between the terminals is not constant.

  The shortest separation distance between the terminals facing each other is appropriately determined according to the purpose and application. For example, when connecting a semiconductor chip and a substrate, the shortest separation distance between the facing terminals is preferably within the range of the pitch between the adjacent terminals on the substrate (the shortest separation distance) from the thickness of the metal foil. More preferably, it is within the range of 3/4 or less of the pitch between adjacent terminals on the substrate, and more preferably within the range of 2/3 or less of the pitch between adjacent terminals of the substrate from the thickness of the metal foil.

  The shortest separation distance between the terminals facing each other can be adjusted by controlling the distance between the hot plates using, for example, a hot press or a crimping device. Further, for example, a spacer having a final desired thickness may be adjusted in advance around the adherend. The adjustment method is not particularly limited as long as it does not depart from the object of the present invention.

  In a preferred embodiment of the present invention, when the resin composition 120 includes a compound having a flux function, the compound is activated by heating, and the surface oxide film of the metal foil and the terminal can be removed. Aggregation due to metal bonding between molten metals and electrical connection due to metal bonding between the molten metal and the terminal are further promoted.

  100 degreeC-330 degreeC is preferable, as for melting | fusing point of the metal foil used for this invention, 140 degreeC-300 degreeC is more preferable, and 180 degreeC-250 degreeC is further more preferable. Therefore, in the adjustment step, the heating temperature is lower than the melting point of the metal foil, preferably 60 ° C to 200 ° C, more preferably 65 ° C to 180 ° C, and further preferably 70 ° C to 150 ° C. The melt viscosity of the resin composition at this time is preferably 0.1 Pa · s to 10000 Pa · s, more preferably 0.5 to 5000 Pa · s, and further preferably 1 to 2000 Pa · s.

(C) Heating step In the heating step, curing of the resin composition is completed at a temperature equal to or higher than the melting point of the metal foil while keeping the shortest separation distance x between the facing terminals adjusted in the adjustment step within the predetermined range. The conductive connecting material is heated so that it does not. In the first embodiment, the shortest separation distance x between the terminals facing each other is adjusted so that the shortest separation distance between the terminals facing each other is larger than the thickness of the metal foil and smaller than the thickness of the conductive connection material. The conductive connection material is heated at a temperature equal to or higher than the melting point of the metal foil.

  As shown in FIG. 1C, by heating the conductive connecting material at a temperature equal to or higher than the melting point of the metal foil, the metal foil is melted and the molten metal is aggregated between the opposing terminals to form a conductive region 110a. Thus, the opposing terminals can be electrically connected. Further, the insulating region 120a is formed by filling the gap around the conductive region 110a with the resin composition, and insulation between adjacent terminals is ensured. Before the conductive connecting material is heated at a temperature equal to or higher than the melting point of the metal foil, the shortest separation distance between the terminals facing each other is adjusted, so that it is possible to prevent the molten resin and metal from flowing out.

  Preferably, in the heating step, the metal foil is melted, the molten metal is agglomerated between the terminals facing each other, and the molten metal and the molten metal and the terminal are metal-bonded, whereby a better electrical connection can be obtained. .

  In a preferred embodiment of the present invention, when the resin composition contained in the conductive connection material contains a compound having a flux function, the solder or tin surface oxide film is removed by the reducing action, and the wettability of the solder or tin is increased. In this state, metal bonding is promoted and aggregation between the opposing terminals is facilitated. Further, since the surface oxide films of the terminals 11 and 21 are also removed by the reducing action of the compound having a flux function and the wettability is enhanced, metal bonding with solder or tin is facilitated.

  In the present invention, since the shortest separation distance between the terminals is adjusted to a predetermined range in advance, the distance that the molten metal flows in the resin can be minimized, so that the desired region can be more reliably obtained. The molten metal can be aggregated to make electrical connection between the opposing terminals. Moreover, it can suppress that a metal remains in resin.

  In the heating step, the conductive connecting material is heated so that the curing of the resin composition is not completed so that the molten metal can flow in the resin. For example, by adjusting the heating time, for example, by shortening the heating time, adjustment is made so that the solder or tin can move in the curable resin, that is, “curing of the curable resin composition is not completed”.

  The heating temperature varies depending on the composition of the metal foil and the resin composition, but is preferably 140 ° C. or higher, more preferably 150 ° C. or higher, and further preferably 200 ° C. or higher. Moreover, it is preferable that it is less than 50 degreeC temperature higher than melting | fusing point of metal foil for the reason of preventing thermal degradation of the board | substrate etc. which are going to connect. Specifically, the heating temperature is preferably 340 ° C. or lower, more preferably 300 ° C. or lower, and particularly preferably 260 ° C. or lower.

  Moreover, it is preferable that the melt viscosity of the resin composition is within a certain range at the heating temperature so that the resin component is prevented from flowing out and the molten metal can flow in the resin. Specifically, the melt viscosity of the resin composition in the heating step is preferably 0.01 Pa · s or more, more preferably 0.05 Pa · s or more, and further preferably 0.1 Pa · s or more. The melt viscosity is preferably 100 Pa · s or less, more preferably 90 Pa · s or less, and still more preferably 80 Pa · s or less.

  The heating method can be performed by using a heating apparatus usually used for manufacturing electric and electronic parts. For example, a die bonder, a flip chip bonder, a wafer bonder, a heat press capable of controlling position, a pressure bonding machine, or the like can be used. When heating, an ultrasonic wave or an electric field may be applied, or special heating such as laser or electromagnetic induction may be applied.

(D) Curing Step In the curing step, as shown in FIG. 1 (d), the resin composition is cured at a temperature lower than the melting point of the metal foil, and the insulating region formed in the heating step is fixed (in the drawing) , See cured insulating region 120b). By fixing the insulating region in this way, the conductive region 110a surrounded by the insulating region can be fixed, and the thermal stability of the electrical connection between the opposing terminals is ensured.

  In the present invention, the resin composition is cured at a temperature lower than the melting point of the metal foil. By doing so, it can suppress that the electroconductive area | region formed at the heating process deform | transforms largely, and can improve the connection reliability between terminals.

  In the curing step, for example, the resin composition is cured by heating the conductive connection material. The heating temperature of the conductive connecting material in the curing step is not particularly limited as long as the resin composition can be cured, but is usually preferably 80 ° C or higher, more preferably 120 ° C or higher, and further preferably 150 ° C or higher. Moreover, generally 310 degrees C or less is preferable, 250 degrees C or less is more preferable, and 200 degrees C or less is further more preferable.

2. Second Embodiment Next, a second embodiment of the present invention will be described with reference to FIG. According to a second embodiment of the present invention, the disposing step of disposing the conductive connecting material between the opposing terminals, heating the conductive connecting material at a temperature lower than the melting point of the metal foil, and setting the shortest separation distance between the opposing terminals. An adjustment step for adjusting to a predetermined range, and the conductive connecting material so as not to complete the curing of the resin composition at a temperature equal to or higher than the melting point of the metal foil while maintaining the shortest separation distance in the predetermined range. A heating step of heating and a curing step of curing the resin composition at a temperature lower than the melting point of the metal foil, wherein the shortest separation distance between the facing terminals is equal to or less than the thickness of the metal foil, And it is the method of adjusting to the range which does not mutually contact between the said opposing terminals. Hereinafter, each step will be described.

(A) Arrangement Step The arrangement step of the second embodiment is the same as the arrangement step of the first embodiment, and as shown in FIG. 2A, a substrate 10 provided with terminals 11 and a terminal 21 are provided. The substrate 20 is aligned so that the terminal 11 and the terminal 21 face each other, and a conductive connecting material 100 comprising a metal foil 110 and a resin composition 120 provided on both surfaces of the metal foil between these terminals. Place.

(B) Adjustment process In the adjustment process of the second embodiment, as shown in FIG. 2 (b), the shortest separation distance y between the opposing terminals is equal to or less than the thickness of the metal foil 110 and the opposing terminals. Adjust the distance so that they do not touch each other. By making the shortest separation distance y between the facing terminals the same as or smaller than the thickness of the metal foil 110, the cohesive force of the molten metal can be further increased. Moreover, it can suppress that a metal remains in resin. In addition, by bringing the metal foil into contact with the upper and lower terminals in advance, the contact area between the metal and the surface between the terminals in the conductive region formed in the next heating process can be increased, and the mechanical strength and connection reliability are increased. Can be further enhanced.

  The shortest separation distance between the terminals facing each other is appropriately determined according to the purpose and application. For example, when connecting a board | substrate and a board | substrate, the shortest separation distance between the terminals which oppose is in the range of 1/4 of the thickness of metal foil from the thickness of metal foil, and the thickness of metal foil from the thickness of metal foil is preferable. A range of 1/3 is more preferable.

  The shortest separation distance between the terminals facing each other can be adjusted, for example, by controlling the distance between the hot plates using a hot press or a crimping device. For example, it can adjust by arrange | positioning the spacer used as final final thickness around a to-be-adhered body beforehand. The adjustment method is not particularly limited as long as it does not depart from the object of the present invention.

  In a preferred embodiment of the present invention, when the resin composition 120 includes a compound having a flux function, the compound is activated by heating, and the surface oxide film of the metal foil and the terminal can be removed. Aggregation due to metal bonding between molten metals and electrical connection due to metal bonding between the molten metal and the terminal are promoted.

  The melting point of the metal foil used in the present invention, the heating temperature in the adjusting step, and the melt viscosity of the resin composition at this time are as described in the first embodiment.

(C) Heating step In the heating step of the second embodiment, the resin composition is maintained at a temperature equal to or higher than the melting point of the metal foil while keeping the shortest separation distance y between the facing terminals adjusted in the adjustment step within the predetermined range. The conductive connecting material is heated so that the curing of is not completed. In the second embodiment, the shortest separation distance y between the facing terminals is equal to or less than the thickness of the metal foil as adjusted in the adjusting step, and the holding terminals are held in a range where they are not in contact with each other. The conductive connection material is heated at a temperature equal to or higher than the melting point of the metal foil.

  As shown in FIG. 2 (c), by heating the conductive connecting material at a temperature equal to or higher than the melting point of the metal foil, the molten metal aggregates between the opposing terminals to form a conductive region 110a. Can be electrically connected. Further, the insulating region 120a is formed by filling the gap around the conductive region 110a with the resin composition, and insulation between adjacent terminals is ensured.

  Preferably, in the heating step, the metal foil is melted, the molten metal is agglomerated between the terminals facing each other, and the molten metal and the molten metal and the terminal are metal-bonded, whereby a better electrical connection can be obtained. . Also in the second embodiment, when the resin composition contained in the conductive connecting material contains a compound having a flux function, the solder or tin surface oxide film is removed by the reduction action, and the wettability of the solder or tin is increased. In this state, metal bonding is promoted and aggregation between the opposing terminals is facilitated. Further, since the surface oxide films of the terminals 11 and 21 are also removed by the reducing action of the compound having a flux function and the wettability is enhanced, metal bonding with solder or tin is facilitated.

  Before the conductive connecting material is heated at a temperature equal to or higher than the melting point of the metal foil, the shortest separation distance between the terminals facing each other is adjusted, so that it is possible to prevent the molten resin and metal from flowing out.

  In the second embodiment, the metal foil in the conductive material is in contact with the surface between the terminals in advance, the distance that the molten metal flows in the resin can be made smaller than in the first embodiment, and in advance Since the metal foil is in contact with the terminal, loading of the molten metal onto the terminal surface starts simultaneously with the melting of the metal foil, so that the molten metal is more reliably aggregated in the desired area and the electrical connection between the opposing terminals is established. It can be carried out. Moreover, it can suppress that a metal remains in resin.

  Further, in the second embodiment, as shown in FIG. 2C, the contact area between the conductive region and the terminal can be increased, so that the mechanical strength and the connection reliability can be further increased.

  As described in the first embodiment, in the heating step, the conductive connecting material is heated so that the curing of the resin composition is not completed so that the molten metal can flow in the resin. For example, by adjusting the heating time, for example, by shortening the heating time, adjustment is made so that the solder or tin can move in the curable resin, that is, “curing of the curable resin composition is not completed”.

  The heating temperature and the melt viscosity of the resin composition are the same as those described in the first embodiment. The heating method is the same as in the first embodiment.

(D) Curing step In the curing step, as shown in FIG. 2 (d), the resin composition is cured at a temperature lower than the melting point of the metal foil, and the insulating region formed in the heating step is fixed (in the figure). , See cured insulating region 120b). By fixing the insulating region in this manner, the conductive region 110a surrounded by the insulating region can be fixed, and the heat resistance stability of the electrical connection between the opposing terminals is ensured. By curing the resin composition at a temperature lower than the melting point of the metal foil, the conductive region formed in the heating step can be prevented from being greatly deformed or flowed, and the connection reliability between the terminals can be improved. The heating temperature of the conductive connection material in the curing step is as described in the description of the first embodiment.

3. Conductive connection material The conductive connection material used in the connection method of the present invention is composed of a resin composition and a metal foil selected from solder foil or tin foil. The form is a laminate having a multilayer structure composed of a resin composition layer and a metal foil layer, and each of the resin composition layer and the metal foil layer may be a single layer or a plurality of layers. The laminated structure of the conductive connecting material is not particularly limited, and may be a two-layer structure (resin composition layer / metal foil layer) of the resin composition layer and the metal foil layer, or either the resin composition layer or the metal foil layer. Alternatively, it may be a three-layer structure including a plurality of both or a multilayer structure having more. In addition, when using two or more resin composition layers or metal foil layers, the composition of each layer may be the same or different.

  In one embodiment of the present invention, the upper and lower layers of the metal foil layer are preferably resin composition layers from the viewpoint of reducing the surface oxide film of the metal foil with a compound having a flux function. For example, a three-layer structure (resin composition layer / metal foil layer / resin composition layer) is preferable. In this case, the thickness of the resin composition layer on both sides of the metal foil layer may be the same or different. The thickness of the resin composition layer may be appropriately adjusted depending on the conductor thickness of the terminal to be connected. For example, when manufacturing a connection terminal using the conductive connection material in which the thickness of the resin composition layer on both sides of the metal foil layer is different, it is preferable to arrange the thinner one on the connection terminal side (electrode side). By shortening the distance between the metal foil and the connection terminal, it becomes easy to control the aggregation of solder or tin to the connection terminal portion.

  Next, the resin composition and metal foil used in the present invention will be described.

(1) Resin Composition First, the resin composition will be specifically described. In the present invention, the resin composition constituting the resin composition layer of the conductive connecting material is preferably a curable resin composition that is cured by heating or irradiation with actinic radiation. Among these, a thermosetting resin composition is preferable in that it is excellent in mechanical properties such as linear expansion coefficient and elastic modulus after curing.

  The resin composition used in the present invention may be in a liquid or solid form at room temperature. Here, “liquid at normal temperature” means a state where there is no fixed form at normal temperature (25 ° C.). Paste forms are also included in liquid form.

  The resin composition used in the present invention includes a curable resin, a film-forming resin, a curing agent, a curing accelerator, a compound having a phenolic hydroxyl group and / or a carboxyl group, and a silane coupling agent, as necessary. Etc. are included. Hereinafter, each component will be described.

(I) Curable resin The curable resin used by this invention will not be specifically limited if normally used as an adhesive agent component for semiconductor device manufacture. For example, epoxy resin, phenoxy resin, silicone resin, oxetane resin, phenol resin, (meth) acrylate resin, polyester resin (unsaturated polyester resin), diallyl phthalate resin, maleimide resin, polyimide resin (polyimide precursor resin), bismaleimide -Triazine resin etc. are mentioned. In particular, the use of a thermosetting resin containing at least one selected from the group consisting of epoxy resins, (meth) acrylate resins, phenoxy resins, polyester resins, polyimide resins, silicone resins, maleimide resins, and bismaleimide-triazine resins. preferable. Especially, it is preferable to use an epoxy resin from a viewpoint that it is excellent in sclerosis | hardenability and preservability, the heat resistance of a hardened | cured material, moisture resistance, and chemical resistance. These curable resins may be used alone or in combination of two or more.

Content of curable resin can be suitably set according to the form of a resin composition.
For example, when the resin composition is liquid, the content of the curable resin is preferably 10% by weight or more, more preferably 15% by weight or more, and still more preferably 20% by weight or more based on the total weight of the resin composition. 25% by weight or more is even more preferable, 30% by weight or more is still more preferable, and 35% by weight or more is particularly preferable. Further, it is preferably less than 100% by weight, more preferably 95% by weight or less, still more preferably 90% by weight or less, still more preferably 75% by weight or less, still more preferably 65% by weight or less, and particularly preferably 55% by weight or less.
When the resin composition is solid, the content of the curable resin is preferably 5% by weight or more, more preferably 10% by weight or more, and still more preferably 15% by weight or more based on the total weight of the resin composition. 20% by weight or more is particularly preferable. Moreover, 90 weight% or less is preferable, 85 weight% or less is more preferable, 80 weight% or less is further more preferable, 75 weight% or less is still more preferable, 65 weight% or less is still more preferable, 55 weight% or less is especially preferable.
When the content of the curable resin is within the above range, the electrical connection strength and the mechanical adhesive strength between the terminals can be sufficiently secured.

  In the present invention, any epoxy resin that is liquid at room temperature and solid at room temperature may be used. An epoxy resin that is liquid at room temperature and an epoxy resin that is solid at room temperature may be used in combination. When the resin composition is liquid, it is preferable to use a liquid epoxy resin at room temperature, and when the resin composition is solid, any of liquid and solid epoxy resins may be used, When using a solid epoxy resin, it is preferable to use a film-forming resin in combination as appropriate.

Preferred examples of the epoxy resin that is liquid at room temperature (25 ° C.) include bisphenol A type epoxy resins and bisphenol F type epoxy resins. A bisphenol A type epoxy resin and a bisphenol F type epoxy resin may be used in combination.
The epoxy equivalent of the epoxy resin that is liquid at room temperature is preferably 150 to 300 g / eq, more preferably 160 to 250 g / eq, and particularly preferably 170 to 220 g / eq. If the epoxy equivalent is less than the above lower limit, the shrinkage of the cured product tends to increase, and warping may occur. On the other hand, when the upper limit is exceeded, when a film-forming resin is used in combination, the reactivity with a film-forming resin, particularly a polyimide resin, tends to decrease.

Examples of solid epoxy resins at room temperature (25 ° C.) include bisphenol A type epoxy resins, bisphenol S type epoxy resins, phenol novolac type epoxy resins, cresol novolac type epoxy resins, glycidyl amine type epoxy resins, and glycidyl ester type epoxies. Resin, trifunctional epoxy resin, tetrafunctional epoxy resin, etc. are mentioned. Among these, solid trifunctional epoxy resin, cresol novolac type epoxy resin and the like are preferable. These epoxy resins may be used alone or in combination of two or more.
The epoxy equivalent of the epoxy resin solid at room temperature is preferably 150 to 3000 g / eq, more preferably 160 to 2500 g / eq, and particularly preferably 170 to 2000 g / eq.
The softening point of the epoxy resin solid at room temperature is preferably 40 to 120 ° C, more preferably 50 to 110 ° C, and particularly preferably 60 to 100 ° C. When the softening point is within the above range, tackiness can be suppressed and handling can be easily performed.

When using an epoxy resin as curable resin, the content can be suitably set according to the form of the resin composition.
For example, the content of the epoxy resin is preferably 10% by weight or more, more preferably 15% by weight or more, still more preferably 20% by weight or more, and even more preferably 25% by weight or more based on the total weight of the resin composition. 30% by weight or more is more preferable, and 35% by weight or more is particularly preferable. Moreover, 90 weight% or less is preferable, 85 weight% or less is more preferable, 80 weight% or less is further more preferable, 75 weight% or less is still more preferable, 65 weight% or less is still more preferable, 55 weight% or less is especially preferable.
When the content of the epoxy resin is within the above range, the reliability of electrical connection between the terminals and the mechanical adhesive strength can be sufficiently ensured.

(Ii) Film-forming resin When a solid resin composition is used, it is preferable to use the curable resin and the film-forming resin in combination. The film-forming resin used in the present invention is not particularly limited as long as it is soluble in an organic solvent and has film-forming properties alone. Either a thermoplastic resin or a thermosetting resin can be used, and these can be used in combination. Specifically, as the film-forming resin, (meth) acrylic resin, phenoxy resin, polyester resin (saturated polyester resin), polyurethane resin, polyimide resin, polyamideimide resin, siloxane-modified polyimide resin, polybutadiene resin, polypropylene resin, Styrene-butadiene-styrene copolymer, styrene-ethylene-butylene-styrene copolymer, polyacetal resin, polyvinyl butyral resin, polyvinyl acetal resin, butyl rubber, chloroprene rubber, polyamide resin, acrylonitrile-butadiene copolymer, acrylonitrile-butadiene- Acrylic acid copolymer, acrylonitrile-butadiene-styrene copolymer, polyvinyl acetate, nylon and the like can be mentioned. Among these, (meth) acrylic resins, phenoxy resins, polyester resins, and polyimide resins are preferable. A film-forming resin may be used alone or in combination of two or more.

  In this specification, “(meth) acrylic resin” refers to a polymer of (meth) acrylic acid and its derivatives, or a copolymer of (meth) acrylic acid and its derivatives and other monomers. Means. When expressed as “(meth) acrylic acid” or the like, it means “acrylic acid or methacrylic acid” or the like.

  Examples of the (meth) acrylic resin used in the present invention include polyacrylic acid, polymethacrylic acid, polymethyl acrylate, polyethyl acrylate, polybutyl acrylate, and polyacrylic acid-2-ethylhexyl. Acid ester, polymethacrylate such as polymethyl methacrylate, polyethyl methacrylate, polybutyl methacrylate, polyacrylonitrile, polymethacrylonitrile, polyacrylamide, butyl acrylate-ethyl acrylate-acrylonitrile copolymer, acrylonitrile- Butadiene copolymer, acrylonitrile-butadiene-acrylic acid copolymer, acrylonitrile-butadiene-styrene copolymer, acrylonitrile-styrene copolymer, methyl methacrylate-styrene copolymer, meta Methyl acrylate-acrylonitrile copolymer, methyl methacrylate-α-methylstyrene copolymer, butyl acrylate-ethyl acrylate-acrylonitrile-2-hydroxyethyl methacrylate-methacrylic acid copolymer, butyl acrylate-ethyl acrylate -Acrylonitrile-2-hydroxyethyl methacrylate-acrylic acid copolymer, butyl acrylate-acrylonitrile-2-hydroxyethyl methacrylate copolymer, butyl acrylate-acrylonitrile-acrylic acid copolymer, butyl acrylate-ethyl acrylate- Examples include acrylonitrile copolymer, ethyl acrylate-acrylonitrile-N, N-dimethylacrylamide copolymer, and the like. Of these, butyl acrylate-ethyl acrylate-acrylonitrile copolymer and ethyl acrylate-acrylonitrile-N, N-dimethylacrylamide are preferable. These (meth) acrylic resins may be used alone or in combination of two or more.

  Among these (meth) acrylic resins, adhesion to the adherend and compatibility with other resin components can be improved, so functional groups such as nitrile group, epoxy group, hydroxyl group and carboxyl group can be added. A (meth) acrylic resin obtained by copolymerizing a monomer having the same is preferred. In such a (meth) acrylic resin, the content of the monomer having the functional group is not particularly limited, but is 0.1% with respect to 100 mol% of all monomers during the synthesis of the (meth) acrylic resin. -50 mol% is preferable, 0.5-45 mol% is more preferable, and 1-40 mol% is especially preferable. When the content of the monomer having the functional group is less than the lower limit, the adhesion tends not to be sufficiently improved, and when it exceeds the upper limit, the adhesive force is too strong and the workability is not sufficiently improved. It is in.

The skeleton of the phenoxy resin used in the present invention is not particularly limited, but bisphenol A type, bisphenol F type, biphenyl type, and the like are preferable. A phenoxy resin having a saturated water absorption of 1% or less is preferable because it can suppress the occurrence of foaming or peeling at high temperatures during bonding or solder mounting. The saturated water absorption rate is obtained by processing a phenoxy resin into a film having a thickness of 25 μm, drying it in a 100 ° C. atmosphere for 1 hour (an absolutely dry state), and further heating the film at a constant temperature and humidity chamber at 40 ° C. and 90% RH The mass change is measured every 24 hours, and the mass at the time when the mass change is saturated can be calculated by the following formula.
Saturated water absorption (%) = {(mass when saturated) − (mass when absolutely dry)} / (mass when absolutely dry) × 100

  The polyimide resin used in the present invention is not particularly limited as long as it is a resin having an imide bond in a repeating unit. For example, what is obtained by making diamine and acid dianhydride react, heating the obtained polyamic acid, and carrying out dehydration ring closure is mentioned.

  Examples of the diamine include aromatic diamines such as 3,3′-dimethyl-4,4′diaminodiphenyl, 4,6-dimethyl-m-phenylenediamine, and 2,5-dimethyl-p-phenylenediamine, Examples thereof include siloxane diamines such as 3-bis (3-aminopropyl) -1,1,3,3-tetramethyldisiloxane. A diamine may be used individually by 1 type, or may use 2 or more types together.

  Examples of the acid dianhydride include 3,3,4,4′-biphenyltetracarboxylic acid, pyromellitic dianhydride, 4,4′-oxydiphthalic dianhydride, and the like. An acid dianhydride may be used individually by 1 type, or may use 2 or more types together.

  The polyimide resin may be soluble or insoluble in a solvent, but is preferably a solvent-soluble one because it can be easily varnished when mixed with other components and has excellent handleability. In particular, a siloxane-modified polyimide resin is preferably used because it can be dissolved in various organic solvents.

  The weight average molecular weight of the film-forming resin used in the present invention is preferably 8,000 to 1,000,000, more preferably 8,500 to 950,000, and further preferably 9,000 to 900,000. When the weight average molecular weight of the film-forming resin is within the above range, the film-forming property can be improved, and the fluidity of the conductive connecting material before curing can be suppressed. The weight average molecular weight of the film-forming resin can be measured by GPC (gel permeation chromatography).

  In the present invention, commercially available products can be used as such film-forming resins. Further, a film-forming resin blended with various additives such as a plasticizer, a stabilizer, an inorganic filler, an antistatic agent, an antioxidant, and a pigment may be used as long as the effects of the present invention are not impaired. Good.

In the conductive connection material used in the present invention, the content of the film-forming resin can be appropriately set according to the form of the curable resin composition to be used.
For example, in the case of a solid resin composition, the content of the film-forming resin is preferably 5% by weight or more and preferably 10% by weight or more with respect to the total weight of the resin composition. More preferably, it is particularly preferably 15% by weight or more. Further, it is preferably 50% by weight or less, more preferably 45% by weight or less, and particularly preferably 40% by weight or less. When the content of the film-forming resin is within the above range, the fluidity of the resin composition before melting can be suppressed, and the conductive connecting material can be easily handled.

(Iii) Curing Agent Preferred examples of the curing agent used in the present invention include phenols, acid anhydrides, and amine compounds. A hardening | curing agent can be suitably selected according to the kind etc. of curable resin. For example, when an epoxy resin is used as the curable resin, good reactivity with the epoxy resin, low dimensional change during curing, and appropriate physical properties after curing (for example, heat resistance, moisture resistance, etc.) are obtained. Phenols are preferably used as the curing agent, and bifunctional or higher functional phenols are more preferable in terms of excellent physical properties after curing of the curable resin. Moreover, such a hardening | curing agent may be used individually by 1 type, and may use 2 or more types together.

  Examples of phenols include bisphenol A, tetramethyl bisphenol A, diallyl bisphenol A, biphenol, bisphenol F, diallyl bisphenol F, trisphenol, tetrakisphenol, phenol novolac resin, cresol novolac resin, and the like. Of these, phenol novolac resins and cresol novolac resins are preferable because they have good reactivity with epoxy resins and excellent physical properties after curing.

When the content of the curing agent has a functional group that functions as a curing agent when the compound having a flux function described below and the type of the curable resin or the curing agent to be used have a functional group, the content should be selected as appropriate. Can do.
For example, when an epoxy resin is used as the curable resin, the content of the curing agent is preferably 0.1 to 50% by weight, more preferably 0.2 to 40% by weight, based on the total weight of the resin composition, 0.5 to 30% by weight is particularly preferred. When the content of the curing agent is within the above range, the reliability of the electrical connection between the terminals and the mechanical strength can be sufficiently ensured.

  In the present invention, it is preferable to use a phenol novolac resin as a curing agent. For example, when using a phenol novolac resin, the content thereof is preferably 1% by weight or more, more preferably 3% by weight or more, particularly preferably 5% by weight or more based on the total weight of the resin composition. 50 weight% or less is preferable, 40 weight% or less is more preferable, and 30 weight% or less is especially preferable. When the content of the phenol novolak resin is less than the lower limit, the curable resin tends to be not sufficiently cured, and when the content exceeds the upper limit, the unreacted phenol novolak resin tends to remain and ion migration tends to occur. .

  When an epoxy resin is used as the curable resin, the content of the phenol novolac resin may be defined by an equivalent ratio with respect to the epoxy resin. For example, the equivalent ratio of phenol novolac resin to epoxy resin is preferably 0.5 to 1.2, more preferably 0.6 to 1.1, and 0.7 to 0.98. Particularly preferred. When the equivalent ratio is less than the lower limit, the heat resistance and moisture resistance after curing of the epoxy resin tend to decrease, and when the upper limit is exceeded, unreacted phenol novolac resin remains and ion migration occurs. It tends to be easy to do.

(Iv) Curing accelerator The curing accelerator used in the present invention is imidazole, 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methyl. Imidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-phenylimidazole, 1-benzyl-2-methylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-ethyl -4-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazolium trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate Tate, , 4-Diamino-6- [2'-methylimidazolyl (1 ')]-ethyl-s-triazine, 2,4-diamino-6- [2'-undecylimidazolyl (1')]-ethyl-s- Triazine, 2,4-diamino-6- [2'-ethyl-4-methylimidazolyl (1 ')]-ethyl-s-triazine, 2,4-diamino-6- [2'-methylimidazolyl (1') ] Isocyanuric acid adduct of 2-ethyl-s-triazine, isocyanuric acid adduct of 2-phenylimidazole, isocyanuric acid adduct of 2-methylimidazole, 2-phenyl-4,5-dihydroxydimethylimidazole, 2-phenyl-4 -Imidazole compounds such as methyl-5-hydroxymethylimidazole.

  Among these curing accelerators, an imidazole compound having a melting point of 150 ° C. or higher is preferable from the viewpoint that solder or tin can move to the surface of the terminal before the curing of the resin composition is completed. Examples of the imidazole compound having a melting point of 150 ° C. or higher include 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 2,4-diamino-6- [2′-methylimidazolyl (1 ')]-Ethyl-s-triazine, 2,4-diamino-6- [2'-undecylimidazolyl (1')]-ethyl-s-triazine, 2,4-diamino-6- [2'-ethyl -4-methylimidazolyl (1 ')]-ethyl-s-triazine, 2,4-diamino-6- [2'-methylimidazolyl (1')]-ethyl-s-triazine isocyanuric acid adduct, 2- Isocyanuric acid adduct of phenylimidazole, 2-phenyl-4,5-dihydroxydimethylimidazole, 2-phenyl-4-methyl-5-hydroxymes Etc. Le imidazole. A hardening accelerator may be used individually by 1 type, or may use 2 or more types together.

Content of a hardening accelerator can be suitably set according to the kind of hardening accelerator to be used.
For example, when an imidazole compound is used, the content of the imidazole compound is preferably 0.001% by weight or more, more preferably 0.003% by weight or more, more preferably 0.005% by weight based on the total weight of the resin composition. A weight percent or more is particularly preferred. Moreover, 1.0 weight% or less is preferable, 0.7 weight% or less is more preferable, and 0.5 weight% or less is especially preferable. When the content of the imidazole compound is less than the lower limit, the effect as a curing accelerator is not sufficiently exhibited, and the curable resin composition may not be sufficiently cured. On the other hand, when the content of the imidazole compound exceeds the above upper limit, the solder or tin does not sufficiently move to the terminal surface before the curing of the resin composition is completed, and the solder or tin remains in the insulating region and the insulating property is sufficient. May not be secured. In addition, the storage stability of the conductive connection material may be reduced.

(V) Compound having a phenolic hydroxyl group and / or carboxyl group The compound having a phenolic hydroxyl group and / or carboxyl group used in the present invention has an action of reducing a metal oxide film such as a terminal and a metal oxide surface oxide film. Is. Examples of the compound having a phenolic hydroxyl group include phenol, o-cresol, 2,6-xylenol, p-cresol, m-cresol, o-ethylphenol, 2,4-xylenol, 2,5-xylenol, m- Ethylphenol, 2,3-xylenol, meditol, 3,5-xylenol, p-tert-butylphenol, catechol, p-tert-amylphenol, resorcinol, p-octylphenol, p-phenylphenol, bisphenol F, bisphenol AF, biphenol Monomers containing phenolic hydroxyl groups such as diallyl bisphenol F, diallyl bisphenol A, trisphenol, tetrakisphenol, phenol novolac resins, o-cresol novolac resins, bisphenols Nord F novolak resins, resins containing a phenolic hydroxyl group such as bisphenol A novolac resin.

  Examples of the compound having a carboxyl group include an aliphatic acid anhydride, an alicyclic acid anhydride, an aromatic acid anhydride, an aliphatic carboxylic acid, and an aromatic carboxylic acid. Examples of the aliphatic acid anhydride include succinic anhydride, polyadipic acid anhydride, polyazeline acid anhydride, and polysebacic acid anhydride. Examples of the alicyclic acid anhydride include methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylhymic anhydride, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, trialkyltetrahydrophthalic anhydride, methylcyclohexene dicarboxylic acid. An anhydride etc. are mentioned. Examples of the aromatic acid anhydride include phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic anhydride, ethylene glycol bistrimellitate, and glycerol tris trimellitate.

Examples of the aliphatic carboxylic acid include formic acid, acetic acid, propionic acid, butyric acid, valeric acid, pivalic acid, caproic acid, caprylic acid, lauric acid, myristic acid, palmitic acid, stearic acid, acrylic acid, methacrylic acid, crotonic acid, Examples include oleic acid, fumaric acid, maleic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, dodecanedioic acid, and pimelic acid. Among them, the following formula (1):
_{HOOC- (CH 2) n -COOH (} 1)
(In Formula (1), n is an integer of 1-20.)
Are preferable, and adipic acid, sebacic acid, and dodecanedioic acid are more preferable.

The structure of the aromatic carboxylic acid is not particularly limited, but a compound represented by the following formula (2) or (3) is preferable.
[Wherein, R ^{1 to} R ⁵ are each independently a monovalent organic group, and at least one of R ^{1 to} R ⁵ is a hydroxyl group. ]
[Wherein, R ^{6 to} R ²⁰ are each independently a monovalent organic group, and at least one of R ^{6 to} R ²⁰ is a hydroxyl group or a carboxyl group. ]

  Aromatic carboxylic acids include benzoic acid, phthalic acid, isophthalic acid, terephthalic acid, hemimellitic acid, trimellitic acid, trimesic acid, merophanic acid, platnic acid, pyromellitic acid, meritic acid, xylylic acid, hemelitonic acid, mesitylene Acid, prenylic acid, toluic acid, cinnamic acid, salicylic acid, 2,3-dihydroxybenzoic acid, 2,4-dihydroxybenzoic acid, gentisic acid (2,5-dihydroxybenzoic acid), 2,6-dihydroxybenzoic acid, 3,5-dihydroxybenzoic acid, gallic acid (3,4,5-trihydroxybenzoic acid), 4-dihydroxy-2-naphthoic acid, 3,5-dihydroxy-2-naphthoic acid, 3,5-2 Examples include naphthoic acid derivatives such as dihydroxy-2-naphthoic acid; phenolphthaline; diphenolic acid and the like.

  Among these, in the present invention, the compound having a phenolic hydroxyl group and / or a carboxyl group is preferably a compound having a flux function and acting as a curing agent for a curable resin. That is, it is preferable to use a compound that has a function of reducing the surface oxide film of metal such as a metal foil and a terminal and has a functional group capable of reacting with a curable resin. The functional group is appropriately selected depending on the type of curable resin. For example, when an epoxy resin is used as the curable resin, the functional group is preferably a functional group capable of reacting with an epoxy group such as a carboxyl group, a hydroxyl group, and an amino group. A compound having a phenolic hydroxyl group and / or a carboxyl group acts as a curing agent, thereby reducing the surface oxide film of metal such as a metal foil and a terminal to increase the wettability of the metal surface and easily form a conductive region. In addition, after the conductive region is formed, the elastic modulus or Tg of the resin can be increased by adding to the curable resin. In addition, since the compound having a phenolic hydroxyl group and / or a carboxyl group acts as a curing agent, there is an advantage that flux cleaning is unnecessary and the occurrence of ion migration due to the remaining flux component can be suppressed.

Such a compound having a phenolic hydroxyl group and / or a carboxyl group preferably has at least one carboxyl group. For example, when an epoxy resin is used as the curable resin, examples of the compound include aliphatic dicarboxylic acids or compounds having a carboxyl group and a phenolic hydroxyl group.
Preferred examples of the aliphatic dicarboxylic acid include compounds in which two carboxyl groups are bonded to an aliphatic hydrocarbon group. The aliphatic hydrocarbon group may be saturated or unsaturated acyclic, or may be saturated or unsaturated cyclic. Further, when the aliphatic hydrocarbon group is acyclic, it may be linear or branched.

  As such aliphatic dicarboxylic acid, the compound whose n is an integer of 1-20 in the said Formula (1) is mentioned preferably. When n in the formula (1) is within the above range, the balance between the flux function, the outgas at the time of adhesion, the elastic modulus after the conductive connecting material is cured, and the glass transition temperature becomes good. In particular, n is preferably 3 or more because an increase in the elastic modulus after curing of the conductive connecting material can be suppressed and the adhesion to the adherend can be improved. In addition, n is preferably 10 or less because it is possible to suppress a decrease in elastic modulus and further improve connection reliability.

  Examples of the aliphatic dicarboxylic acid represented by the formula (1) include glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, and pentadecane. Examples include diacid, octadecanedioic acid, nonadecanedioic acid, and eicosanedioic acid. Among these, adipic acid, suberic acid, sebacic acid and dodencandioic acid are preferable, and sebacic acid is particularly preferable.

  Examples of the compound having a carboxyl group and a phenolic hydroxyl group include salicylic acid, 2,3-dihydroxybenzoic acid, 2,4-dihydroxybenzoic acid, gentisic acid (2,5-dihydroxybenzoic acid), and 2,6-dihydroxybenzoic acid. Benzoic acid derivatives such as acid, 3,4-dihydroxybenzoic acid, gallic acid (3,4,5-trihydroxybenzoic acid); 1,4-dihydroxy-2-naphthoic acid, 3,5-dihydroxy-2- Naphthoic acid derivatives such as naphthoic acid; phenolphthaline; diphenolic acid and the like. Of these, phenolphthaline, gentisic acid, 2,4-dihydroxybenzoic acid, and 2,6-dihydroxybenzoic acid are preferable, and phenolphthalin and gentisic acid are particularly preferable.

  The compound which has a phenolic hydroxyl group and / or a carboxyl group may be used individually by 1 type, or may use 2 or more types together. In addition, since any compound easily absorbs moisture and causes voids, it is preferable to dry a compound having a phenolic hydroxyl group and / or a carboxyl group in advance before use.

Content of the compound which has a phenolic hydroxyl group and / or a carboxyl group can be suitably set according to the form of the resin composition to be used.
For example, when the resin composition is liquid, the content of the compound having a phenolic hydroxyl group and / or a carboxyl group is preferably 1% by weight or more, more preferably 2% by weight or more based on the total weight of the resin composition. It is preferably 3% by weight or more. Moreover, 50 weight% or less is preferable, 40 weight% or less is more preferable, 30 weight% or less is further more preferable, and 25 weight% or less is especially preferable.
In the case of a solid resin composition, the content of the compound having a phenolic hydroxyl group and / or a carboxyl group is preferably 1% by weight or more, more preferably 2% by weight or more based on the total weight of the resin composition. It is preferably 3% by weight or more. Moreover, 50 weight% or less is preferable, 40 weight% or less is more preferable, 30 weight% or less is further more preferable, and 25 weight% or less is especially preferable.
If the content of the compound having a phenolic hydroxyl group and / or a carboxyl group is within the above range, the metal foil and the surface oxide film of the terminal can be removed to such an extent that they can be electrically joined. Furthermore, the elastic modulus or Tg of the resin can be increased by efficiently adding to the resin during curing. Moreover, generation | occurrence | production of the ion migration resulting from the compound which has an unreacted flux function can be suppressed.

(Vi) Silane coupling agent Examples of the silane coupling agent used in the present invention include an epoxy silane coupling agent and an aromatic-containing aminosilane coupling agent. By adding the silane coupling agent, the adhesion between the bonding member and the conductive connecting material can be enhanced. A silane coupling agent may be used individually by 1 type, and may use 2 or more types together.

  Content of a silane coupling agent can be suitably selected according to types, such as a joining member and curable resin. For example, the content of the silane coupling agent is preferably 0.01% by weight or more, more preferably 0.05% by weight or more, and particularly preferably 0.1% by weight or more with respect to the total weight of the curable resin composition. It is preferably 2% by weight or less, more preferably 1.5% by weight or less, and particularly preferably 1% by weight or less.

  The resin composition used in the present invention includes plasticizers, stabilizers, tackifiers, lubricants, antioxidants, fillers such as inorganic fillers, antistatic agents, pigments, etc., as long as the effects of the present invention are not impaired. May be blended.

  In the present invention, the resin composition can be prepared by mixing and dispersing the above components. The mixing method and dispersion method of each component are not specifically limited, It can mix and disperse | distribute by a conventionally well-known method.

  Moreover, in this invention, you may mix the said each component in a solvent or under absence of solvent, and may prepare a liquid resin composition. The solvent used at this time is not particularly limited as long as it is inert to each component. For example, acetone, methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), diisobutyl ketone (DIBK), cyclohexanone, Ketones such as diacetone alcohol (DAA); aromatic hydrocarbons such as benzene, xylene and toluene; alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol and n-butyl alcohol; methyl cellosolve, ethyl cellosolve, butyl cellosolve; Cellosolves such as methyl cellosolve acetate and ethyl cellosolve acetate, N-methyl-2-pyrrolidone (NMP), tetrahydrofuran (THF), dimethylformamide (DMF), dibasic acid ester (DB ), Ethyl 3-ethoxypropionate (EEP), and dimethyl carbonate (DMC). Moreover, it is preferable that the usage-amount of a solvent is an quantity from which the solid content concentration of the component mixed with the solvent will be 10 to 60 weight%.

  In a preferred embodiment of the present invention, the epoxy resin is 10 to 90% by weight, the curing agent is 0.1 to 50% by weight, the film-forming resin is 5 to 50% by weight, the phenolic hydroxyl group and / or the total weight of the resin composition. Or what contains 1 to 50 weight% of compounds which have a carboxyl group is more preferable. Moreover, it has 20-80 weight% of epoxy resins, 0.2-40 weight% of hardening | curing agents, 10-45 weight% of film-forming resin, and a phenolic hydroxyl group and / or a carboxyl group with respect to the total weight of a resin composition. More preferred are those containing 2 to 40% by weight of the compound. Moreover, it has 35-55 weight% of epoxy resins, 0.5-30 weight% of hardening | curing agents, 15-40 weight% of film-forming resin, and a phenolic hydroxyl group and / or a carboxyl group with respect to the total weight of a resin composition. Those containing 3 to 25% by weight of the compound are particularly preferred.

The content of the resin composition in the conductive connecting material of the present invention can be appropriately set according to the form of the resin composition.
For example, when the resin composition is liquid, the content of the resin composition is preferably 10% by weight or more, more preferably 20% by weight or more, and particularly preferably 25% by weight or more based on the total weight of the conductive connecting material. . Moreover, 95 weight% or less is preferable, 80 weight% or less is more preferable, and 75 weight% or less is especially preferable.
When the resin composition is solid, the content of the resin composition is preferably 10% by weight or more, more preferably 15% by weight or more, and particularly preferably 20% by weight or more based on the total weight of the conductive connecting material. Moreover, 95 weight% or less is preferable, 80 weight% or less is more preferable, and 75 weight% or less is especially preferable.

  In the conductive connection material of the present invention, the thickness of each resin composition layer is not particularly limited, but is preferably 1 μm or more, more preferably 3 μm or more, and particularly preferably 5 μm or more. Further, the thickness of the resin composition layer is preferably 200 μm or less, more preferably 150 μm or less, and particularly preferably 100 μm or less. When the thickness of the resin composition layer is within the above range, the gap between adjacent terminals can be sufficiently filled with the resin composition, and after the resin composition is cured, the mechanical adhesive strength after solidification and the opposite are opposed. A sufficient electrical connection between the terminals can be ensured, and the connection terminals can be manufactured.

  When the conductive connection material of the present invention includes a plurality of resin composition layers, the composition of each resin composition layer may be the same, or may differ depending on the type of resin component used, the difference in formulation, and the like. The physical properties such as melt viscosity and softening temperature of the resin composition layer may be the same or different. For example, a liquid resin composition layer and a solid resin composition layer may be used in combination.

(2) Metal foil In this invention, a metal foil layer is a layer comprised with the metal foil chosen from solder foil or tin foil. The metal foil layer should just be formed in at least one part of the resin composition layer by planar view, and may be formed in the whole surface of the resin composition layer.

  The shape of the metal foil layer is not particularly limited, and a certain shape may be repeatedly formed in a pattern shape, or the shape may be irregular. Regular shapes and irregular shapes may be mixed. FIG. 3 is a schematic plan view showing an example of the shape of the metal foil layer. Metal foil layers 110 having various shapes are formed on the resin composition layer 120. As the shape of the metal foil layer, for example, a dotted pattern (a), a striped pattern (b), a polka dot pattern (c), a rectangular pattern (d), or a checkered pattern as shown in FIG. Examples include (e), a frame shape (f), a lattice pattern shape (g), and a multiple frame shape (h). These shapes are examples, and these shapes can be combined or deformed depending on the purpose and application.

  In one embodiment of the present invention, when connecting a full grid type adherend in which the electrode to be connected is disposed on the entire connection surface of the adherend, a sheet-like metal is formed on the entire surface of the resin composition. It is preferable to form a foil.

  In addition, when connecting a peripheral type adherend in which the electrode to be connected is arranged in the periphery of the connection surface of the adherend, from the viewpoint of effectively using the metal foil, and between adjacent electrodes From the viewpoint of not leaving the metal foil, it is preferable to form a patterned metal foil repeatedly on at least a part of the resin composition. At this time, the shape of the metal foil can be appropriately selected depending on the pitch and form of the electrodes.

  The metal foil used in the present invention is not particularly limited as long as it has a surface oxide film that can be removed by the reducing action of a compound having a phenolic hydroxyl group and / or carboxyl group, but tin (Sn), lead (Pb ), Silver (Ag), bismuth (Bi), indium (In), zinc (Zn), nickel (Ni), antimony (Sb), iron (Fe), aluminum (Al), gold (Au), germanium (Ge) ) And copper (Cu), or an alloy of at least two kinds of metals selected from the group consisting of copper (Cu), or tin alone.

  Among these, considering the melting temperature and mechanical properties, the metal foil is composed of Sn—Pb alloy, Sn—Bi alloy which is lead-free solder, Sn—Ag—Cu alloy, Sn—In alloy, Sn A solder foil made of an alloy containing Sn such as an alloy of -Ag is more preferable. When using an Sn—Pb alloy, the content of tin is preferably 30% by weight or more and less than 100% by weight, more preferably 35% by weight or more and less than 100% by weight, and particularly preferably 40% by weight or more. Moreover, less than 100 weight% is preferable. In the case of lead-free solder, the content of tin is preferably 15% by weight or more and less than 100% by weight, more preferably 20% by weight or more and less than 100% by weight, and particularly preferably 25% by weight or more and less than 100% by weight. For example, Sn-Pb alloys include Sn63-Pb (melting point 183 ° C), Sn-3.0Ag-0.5Cu (melting point 217 ° C), Sn-3.5Ag (melting point 221 ° C), Sn-58Bi (melting point). 139 ° C.), Sn-9.0Zn (melting point 199 ° C.), Sn-3.5Ag-0.5Bi-3.0In (melting point 193 ° C.), Au-20Sn (melting point 280 ° C.), and the like.

  The metal foil may be appropriately selected according to the heat resistance of the electronic member or semiconductor device to be connected. For example, in the connection between terminals in a semiconductor device, the melting point is 330 ° C. or lower (more preferably 300 ° C. or lower, particularly preferably 280 ° C. or lower, more preferably, in order to prevent the members of the semiconductor device from being damaged by thermal history. It is preferable to use a metal foil that is 260 ° C. or lower. In order to ensure the heat resistance of the semiconductor device after the connection between terminals, it is preferable to use a metal foil having a melting point of 100 ° C. or higher (more preferably 110 ° C. or higher, particularly preferably 120 ° C. or higher). In addition, melting | fusing point of metal foil can be measured with a differential scanning calorimeter (DSC).

  The thickness of the metal foil can be appropriately selected according to the gap between the opposing terminals, the separation distance between adjacent terminals, and the like. For example, in the case of connection between connection terminals such as a semiconductor chip, a substrate, and a semiconductor wafer in a semiconductor device, the thickness of the metal foil is preferably 0.5 μm or more, more preferably 1 μm or more, particularly preferably 2 μm or more, 100 micrometers or less are preferable, 50 micrometers or less are more preferable, and 20 micrometers or less are especially preferable. If the thickness of the metal foil is less than the lower limit, the number of unconnected terminals tends to increase due to insufficient solder or tin. On the other hand, if the thickness exceeds the upper limit, bridging occurs between adjacent terminals due to excessive solder or tin, and shorting easily occurs. There is a tendency.

  Examples of the method for producing the metal foil include a method of producing from a lump such as an ingot by rolling, and a method of forming the metal foil layer directly on the resin composition layer by vapor deposition, sputtering, plating, or the like. In addition, as a method for producing a metal foil having a repetitive pattern, for example, a method of punching a metal foil into a predetermined pattern, a method of forming a predetermined pattern by etching, etc., or using a shielding plate or a mask Examples thereof include a method of forming by vapor deposition, sputtering, plating, and the like.

  The content of the metal foil is preferably 5% by weight or more, more preferably 20% by weight or more, and particularly preferably 30% by weight or more with respect to the total weight of the conductive connecting material. Moreover, less than 100 weight% is preferable, 80 weight% or less is more preferable, and 70 weight% or less is especially preferable. If the content of the metal foil is less than the above lower limit, unconnected terminals may increase due to insufficient solder or tin. On the other hand, if the content of the metal foil exceeds the above upper limit, bridging is likely to occur between adjacent terminals due to excessive solder or tin.

  Or you may define content of metal foil with the volume ratio with respect to a conductive connection material. For example, the content of the metal foil is preferably 1% by volume or more, more preferably 5% by volume or more, and particularly preferably 10% by volume or more with respect to the conductive connection material. Moreover, 90 volume% or less is preferable, 80 volume% or less is more preferable, and 70 volume% or less is especially preferable. If the content of the metal foil is less than the above lower limit, unconnected terminals may increase due to insufficient solder or tin. On the other hand, if the content of the metal foil exceeds the above upper limit, bridging is likely to occur between adjacent terminals due to excessive solder or tin.

  In the present invention, the form of the conductive connection material can be appropriately selected according to the form of the resin composition. For example, when the resin composition is liquid, the resin composition is applied on both sides of a metal foil, or the resin composition is applied on a release substrate such as a polyester sheet, and semi-cured at a predetermined temperature (B-stage) For example, a film obtained by drying and forming a film and pasting metal foils together to form a film can be used as the conductive connection material. When the resin composition is solid, the resin composition varnish dissolved in an organic solvent is applied onto a release substrate such as a polyester sheet and dried at a predetermined temperature, and then bonded to a metal foil or vapor deposition, etc. A film formed using the above method can be used as a conductive connection material.

  Moreover, the conductive connection material of this invention and the metal foil used for this can also use what gave the embossing in order to improve a contact with a terminal.

  The thickness of the conductive connecting material of the present invention is not particularly limited, but is preferably 1 μm or more, more preferably 3 μm or more, particularly preferably 5 μm or more, preferably 200 μm or less, more preferably 150 μm or less, and particularly preferably 100 μm or less. . When the thickness of the conductive connecting material is within the above range, the resin composition can be sufficiently filled in the gap between adjacent terminals. In addition, the mechanical adhesive strength after the resin component is cured or solidified and the electrical connection between the opposing terminals can be sufficiently ensured. In addition, it is possible to manufacture a connection terminal according to the purpose and application.

  When the resin composition used in the present invention is liquid at 25 ° C., for example, the metal foil is dipped in the liquid resin composition, and the liquid resin composition is adhered to both surfaces of the metal foil, so that the conductive connection of the present invention is performed. The material can be manufactured. When the thickness of the resin composition needs to be controlled, it is prepared by a method in which a metal foil immersed in a liquid resin composition is passed through a bar coater having a certain gap or a method in which a liquid resin composition is sprayed with a spray coater or the like. can do.

  Moreover, when the resin composition used by this invention is a film form at 25 degreeC, a conductive connection material can be manufactured as follows, for example. First, a varnish of a resin composition dissolved in an organic solvent is applied on a release substrate such as a polyester sheet, dried at a predetermined temperature to form a film, and a film-like resin composition is produced. Next, two resin compositions formed on the release substrate were prepared, and the resin composition was placed on top and bottom of the metal foil by laminating with a hot roll with the metal foil sandwiched between the resin composition / metal. A three-layer conductive connecting material made of a foil / resin composition can be produced. In addition, a two-layer conductive connecting material composed of a resin composition / metal foil can be produced by arranging the resin composition on one side of the metal foil by the above-described laminating method.

  When using a wound metal foil, the film-shaped resin composition is laminated on the upper and lower sides or one side of the metal foil with a hot roll using the metal foil as a base substrate, so that a wound conductive film is used. A connection material can also be obtained. Furthermore, when using a wound metal foil, it is possible to produce a wound conductive connection material by directly applying a varnish-like resin composition to the upper or lower side or one side of the metal foil and volatilizing the solvent. it can.

  When making conductive connection materials using patterned metal foil, place the metal foil on the peeling substrate, half-cut the metal foil with a mold from the metal foil side, and remove the excess metal foil Thus, a patterned metal foil is prepared, and the film-like resin composition may be laminated with a hot roll. When the resin composition is provided on both surfaces of the patterned metal foil, the release substrate is peeled off, and the film-shaped resin composition is formed on the surface of the patterned metal foil opposite to the surface on which the resin composition is formed. What is necessary is just to laminate the thing further.

  In the present invention, the conductive connection material obtained in this way is placed between the opposing terminals, and this is heated while controlling the temperature stepwise in the adjustment process and the heating process, thereby providing conductivity in a desired region. Regions and insulating regions can be formed. Furthermore, by fixing the conductive region surrounded by the insulating region by curing the resin and fixing the insulating region, connection reliability is secured and electrical connection with excellent heat resistance is realized. be able to. According to the present invention, since a conductive region and an insulating region can be formed in a desired region with high precision between opposing terminals, a large number of terminals in a fine wiring circuit can be connected together. Is possible.

  The connection method of the present invention can be used, for example, when connecting terminals formed on a semiconductor wafer, a semiconductor chip, a rigid substrate, a flexible substrate, and other electrical and electronic components.

  EXAMPLES Hereinafter, although this invention is demonstrated based on an Example, this invention is not restrict | limited to the following Example.

[Example 1]
(1) Preparation of Curable Resin Composition Each component shown in Table 1 was dissolved in methyl ethyl ketone (MEK) to obtain a resin composition varnish having a resin solid content of 40% by weight. The obtained varnish was applied to a polyester sheet using a comma coater and dried at 90 ° C. for 5 minutes to obtain a film-like curable resin composition having a thickness of 30 μm.

(2) Melt viscosity of curable resin composition Three samples of the curable resin composition obtained in (1) above were stacked to prepare a sample having a thickness of 90 μm, and a viscoelasticity measuring device (Rheometric Scientific F The melt viscosity was measured under the conditions of parallel plate 25 mmφ, gap 60 μm, frequency 10 rad / s, and heating rate 20 ° C./min. Here, the melt viscosity at the temperature of the adjusting process and the heating process of each example and comparative example was used as a measured value.

(3) Production of conductive connecting material Solder foil having the composition shown in Table 1 on the film-like curable resin composition obtained in (1) above under the conditions of 60 ° C., 0.2 MPa, and 0.3 m / min. (5 μm) was laminated on both sides to produce a conductive connection material having a thickness of 65 μm.

(4) Production of substrate-substrate laminate a. Arrangement Step (1) The obtained conductive connection material is composed of an FR-4 base material (thickness 0.1 mm) and a circuit layer (copper circuit, thickness 12 μm), and Ni / Au plating (thickness 3 μm) is formed on the copper circuit. On a substrate having connection terminals (terminal diameter (diameter of cylindrical terminal) 50 μm, distance between centers of adjacent terminals 100 μm, shortest separation distance between adjacent terminals 50 μm) formed at 100 ° C. for 5 seconds. It was temporarily bonded (arranged).
Next, prepare a board with the same specifications as the board used in the placement step, align the connection terminals of the board to which the conductive connection material is temporarily bonded and the connection terminals of the prepared board so as to face each other. The conductive connecting material was mounted on a temporarily bonded substrate.
b. Adjustment Step Next, as shown in Table 1, the shortest separation distance (distance between opposing terminals) was adjusted using a thermocompression bonding apparatus (“TMV1-200ASB” manufactured by Tsukuba Mechanics Co., Ltd.). The heating temperature at this time was 100 ° C., and the heating time was 10 seconds.
c. Heating Step Next, using a thermocompression bonding apparatus (“TMV1-200ASB” manufactured by Tsukuba Mechanics Co., Ltd.), heating is performed at 230 ° C. for 20 seconds under the condition of the shortest separation distance as in the adjustment step. Connection terminals were connected to obtain a laminate of substrates.
d. Curing Step Next, the obtained laminate was heated at 180 ° C. for 1 hour to cure the curable resin composition.

(5) Connection resistance measurement between terminals facing each other in the substrate-substrate laminate The connection resistance is determined by a four-terminal method (resistance meter: Iwasaki Tsushinki Co., Ltd.) between the opposing terminals in the laminate obtained in (4) above. 12 points were measured by “Digital Multimeter VOA7510” manufactured by Co., Ltd. and measurement probe: “Pin type lead 9771” manufactured by Hioki Electric Co., Ltd.). The case where the average value was less than 30 mΩ was determined as “A”, the case where it was 30 mΩ or more and less than 100 mΩ was determined as “B”, and the case where it was 100 mΩ or more was determined as “C”.

(6) Conductivity path forming property between opposing terminals in substrate-substrate laminate The cross section between the terminals of the 10 pairs of opposing terminals in the laminate obtained in (4) above is scanned with an electron microscope (SEM) ( JEOL Co., Ltd. “JSM-7401F”) When all of the 10 sets have a cylindrical or elliptical conductive path formed by solder, “A” indicates that one set of conductive paths is formed. The case where there was a non-existing terminal was determined as “B”, and the case where it was in short contact with an adjacent terminal was determined as “C”.

(7) Measurement of the shortest separation distance between opposing terminals in the substrate-substrate laminate The thickness of the laminate after the adjustment step and the heating step is measured with a micrometer, respectively, and the substrate thickness (base material 100 μm + copper is determined from the measured values. Subtract the circuit 12 μm + Ni / Au plating 3 μm, and use it as the shortest separation distance after the adjustment process and after the heating process, and change rate of the shortest separation distance after the curing process ({1- [shortest separation distance after the curing process] / [adjustment process] Subsequent shortest separation distance]} × 100) was calculated. The case where the rate of change was less than 10% was “A”, the case where it was 10% or more and less than 20% was “B”, the case where the rate of change was 20% or more, or the solder foil was broken, “C”.

[Example 2]
Except having adjusted the shortest separation distance in an adjustment process and a heating process to 4 micrometers, preparation of the conductive connection material and preparation and evaluation of the board | substrate laminated body were performed like Example 1. FIG.

[Comparative Example 1]
Without adjusting the shortest separation distance between the terminals in the adjustment step and the heating step, the connection terminal of the substrate on which the conductive connection material is temporarily bonded and the connection terminal of the prepared substrate are opposed to each other, and the thermocompression bonding apparatus ( (TMV1-200ASB, manufactured by Tsukuba Mechanics Co., Ltd.) was used for pressure bonding at 100 ° C., 0.2 MPa, for 30 seconds, and the same thermocompression bonding apparatus (“TMV1-200ASB, manufactured by Tsukuba Mechanics Co., Ltd.)) was used. A laminate was obtained in the same manner as in Example 1 except that pressure bonding was performed at 230 ° C. and 0.5 MPa for 120 seconds. Thereafter, in the same manner as in Example 1, the obtained laminate was heated at 180 ° C. for 1 hour to cure the curable resin composition to obtain a substrate-substrate laminate.
For the substrate-substrate laminate produced in Comparative Example 1, the connection resistance and the shortest separation distance between opposing terminals in the laminate before curing were evaluated in the same manner as in Examples 1 and 2. It did not evaluate about the shortest separation distance between the terminals which oppose in the laminated body after hardening.

The results are shown in Table 1.

The resin composition components and metal foils in Table 1 were as shown below.
(A) Epoxy resin: bisphenol A type epoxy resin, “EPICLON-840S” manufactured by Dainippon Ink and Chemicals, epoxy equivalent of 185 g / eq
(B) Curing agent: phenol novolac, “PR-53647” manufactured by Sumitomo Bakelite Co., Ltd.
(C) Film-forming resin: modified biphenol type phenoxy resin, “YX-6654” manufactured by Japan Epoxy Resin Co., Ltd., weight average molecular weight 39,000
(D) Compound having flux function: Sebacic acid, “Sebacic acid” manufactured by Tokyo Chemical Industry Co., Ltd.
(E) Silane coupling agent: 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, “KBM-303” manufactured by Shin-Etsu Chemical Co., Ltd.
(F) Imidazole: 2-phenyl-4-methylimidazole, “Cureazole 2P4MZ” manufactured by Shikoku Chemicals Co., Ltd.
(G) Solder foil: Sn / Ag / Cu = 96.5 / 3.0 / 0.5 (melting point: 217 ° C.), thickness 5 μm

As shown in Table 1, in the substrate-substrate laminates of Examples 1 and 2 manufactured according to the method of the present invention, the connection resistance between the terminals facing each other is small, and a cylindrical or elliptical conduction path in all 10 sets. Thus, good electrical connection was obtained between the terminals facing each other.
On the other hand, in the case of Comparative Example 1 in which the shortest separation distance between the terminals is not controlled in the adjustment step and the heating step, the average value of the connection resistance is 100 mΩ or more, and good electrical connection cannot be obtained. In Comparative Example 1, it is assumed that the connection resistance is large, and there are short-circuits and disconnections. Therefore, the evaluation of the conductive path forming property is “B” or “C” in Table 1.

  By using the connection method of the present invention, electrical connection between electronic members in electrical and electronic parts can be more reliably performed. ADVANTAGE OF THE INVENTION According to this invention, the favorable electrical connection between electronic members and high insulation reliability can be reconciled, and a highly reliable electrical connection can be implement | achieved. By using the connection method of the present invention, terminal-to-terminal connection in a fine wiring circuit can be performed at once. By using the connection method of the present invention, it is possible to meet the demand for higher functionality and smaller size of electronic devices.

DESCRIPTION OF SYMBOLS 10, 20 ... Board | substrate 11, 21 ... Terminal 110 ... Metal foil 120 ... Resin composition 110a ... Conductive area | region 120a ... Insulating area | region 120b ... Hardened insulating area | region

Claims (20)

A method of electrically connecting opposing terminals using a conductive connection material having a laminated structure composed of a resin composition and a metal foil selected from solder foil or tin foil,
An arrangement step of arranging the conductive connection material between opposing terminals;
An adjustment step of heating the conductive connection material at a temperature lower than the melting point of the metal foil, and adjusting the shortest separation distance between opposing terminals to a predetermined range;
A heating step of heating the conductive connecting material so that the curing of the resin composition is not completed at a temperature equal to or higher than the melting point of the metal foil while maintaining the shortest separation distance in the predetermined range;
Curing the resin composition at a temperature lower than the melting point of the metal foil.   The method according to claim 1, wherein in the adjusting step, the shortest separation distance between the opposing terminals is adjusted to a range larger than the thickness of the metal foil and smaller than the thickness of the conductive connection material.   The method according to claim 1, wherein in the adjusting step, the shortest separation distance between the opposing terminals is adjusted to a range that is equal to or less than a thickness of the metal foil and that the opposing terminals do not contact each other.   The method according to any one of claims 1 to 3, wherein, in the heating step, the metal foil is melted and the molten metal aggregates between opposing terminals to electrically connect the opposing terminals.   The method of Claim 4 which electrically connects between the terminals which oppose by the metal coupling | bonding of the said molten metal and the said terminal.   The method according to claim 1, wherein in the adjustment step, the shortest separation distance between the opposing terminals is adjusted to a range smaller than the shortest separation distance between adjacent terminals.   The method of any one of Claims 1-6 whose melt viscosity of the resin composition in the said adjustment process is 0.1 Pa.s-10000 Pa.s.   The method of any one of Claims 1-7 whose melt viscosity of the resin composition in the said heating process is 0.01 Pa.s-100 Pa.s.   The method of any one of Claims 1-8 whose melting | fusing point of the said metal foil is 100 to 330 degreeC.   The method of any one of Claims 1-7 whose heating temperature of the conductive connection material in the said adjustment process is 60 to 200 degreeC.   The method according to any one of claims 1 to 10, wherein a heating temperature of the conductive connecting material in the heating step is less than a temperature higher by 50 ° C than a melting point of the metal foil.   The method of any one of Claims 1-8 whose heating temperature of the electrically conductive connection material in the said heating process is 140 to 340 degreeC.   The method of any one of Claims 1-12 whose heating temperature of the conductive connection material in the said hardening process is 80 to 310 degreeC.   The method according to any one of claims 1 to 13, wherein the conductive connecting material includes a laminated structure composed of a resin composition layer / metal foil layer / resin composition layer.   The method according to claim 1, wherein the conductive connection material includes a laminated structure including a resin composition layer / metal foil layer.   The method according to any one of claims 1 to 15, wherein the resin composition comprises an epoxy resin, a curing agent, and a compound having a phenolic hydroxyl group and / or a carboxyl group.   The method according to claim 16, wherein the resin composition further comprises a film-forming resin selected from the group consisting of a phenoxy resin, a (meth) acrylic resin, and a polyimide resin.   The resin composition is 10 to 90% by weight of an epoxy resin, 0.1 to 50% by weight of a curing agent, 5 to 50% by weight of a film-forming resin, and a phenolic hydroxyl group and / or carboxyl with respect to the total weight of the resin composition. The method according to claim 1, comprising 1 to 50% by weight of a compound having a group. The method according to any one of claims 16 to 18, wherein the compound having a phenolic hydroxyl group and / or a carboxyl group includes a compound represented by the following general formula (1).
_{HOOC- (CH 2) n-COOH} (1)
[In formula, n is an integer of 1-20. ] The method according to any one of claims 16 to 19, wherein the compound having a phenolic hydroxyl group and / or a carboxyl group includes a compound represented by the following general formula (2) and / or (3).
[Wherein, R ^{1 to} R ⁵ are each independently a monovalent organic group, provided that at least one of R ^{1 to} R ⁵ is a hydroxyl group. ]
[Wherein, R ^{6 to} R ²⁰ are each independently a monovalent organic group, provided that at least one of R ^{6 to} R ²⁰ is a hydroxyl group or a carboxyl group. ]