KR20070010012A - Die for manufacturing anisotropic conductive sheet and method for manufacturing anisotropic conductive sheet - Google Patents

Abstract

A die for manufacturing an anisotropic conductive sheet and a method for manufacturing the anisotropic conductive sheet are provided for manufacturing the anisotropic conductive sheet, which has conductive path forming parts exhibiting a prescribed conductivity even when the pitch of the conductive path forming parts to be formed is small, and surely provides prescribed insulation between the adjacent conductive path forming parts. The die for manufacturing the anisotropic conductive sheet is provided for manufacturing the anisotropic conductive sheet having a plurality of the conductive path forming parts containing conductive particles in a condition where the conductive particles exhibiting magnetism are oriented in a thickness direction in an insulating elastic polymeric substance, and insulating parts, which are composed of an insulating elastic polymeric substance that insulates the conductive path forming parts from one another. The die is composed of a board, and a ferromagnetic layer, which is arranged on the board in accordance with a pattern that corresponds to a pattern of the conductive path forming parts. The board is made of a feeble magnetic material. ® KIPO & WIPO 2007

Description

DIE FOR MANUFACTURING ANISOTROPIC CONDUCTIVE SHEET AND METHOD FOR MANUFACTURING ANISOTROPIC CONDUCTIVE SHEET

BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to an anisotropic conductive sheet production type and an anisotropic conductive sheet manufacturing method, and more particularly, to an integrated circuit formed on a wafer, an integrated circuit obtained by dicing this wafer, a package IC, a printed circuit board, and the like. The present invention relates to a mold for producing an anisotropic conductive sheet and a method for producing an anisotropic conductive sheet for producing an anisotropic conductive sheet which can be preferably used for electrical inspection.

Anisotropically conductive elastomer sheets have a conductive conductivity portion that exhibits conductivity only in the thickness direction or exhibits conductivity only in the thickness direction when pressed in the thickness direction, and does not use any means such as soldering or mechanical fitting. Since it is possible to achieve a compact electrical connection, and to absorb mechanical shocks and deformations, and to make a smooth connection, such a feature is used, for example, an electronic calculator, an electronic digital clock, an electronic camera, a computer, etc. Background Art In the field of keyboards and the like, it is widely used as a connector for achieving mutual electrical connection between a circuit device, for example, a printed circuit board, a leadless chip carrier, a liquid crystal panel, and the like.

In addition, in the electrical inspection of semiconductor integrated circuit devices such as package ICs and MCMs, wafers with integrated circuits, and printed circuit boards, the electrodes to be inspected and formed on the surface of the circuit board for inspection are formed on one surface of the circuit device to be inspected. In order to achieve electrical connection of the inspection electrode, interposing an anisotropic conductive elastomer sheet between the inspection electrode region of the circuit device as an inspection object and the inspection electrode region of the inspection circuit board is performed.

Conventionally, such an anisotropically conductive elastomer sheet is known to have various structures. For example, Patent Document 1 and the like disclose an anisotropically conductive elastomer sheet obtained by dispersing conductive particles exhibiting magnetic properties in a state oriented so as to be arranged in the thickness direction in the elastomer (hereinafter, This is referred to as a "dispersed anisotropic conductive sheet"), and Patent Document 2 and the like disclose a plurality of conductive path forming portions extending in the thickness direction and insulated from each other by unevenly distributing conductive particles exhibiting magnetic properties in the elastomer. An anisotropic conductive sheet (hereinafter referred to as a "distributed anisotropic conductive sheet") having an insulating portion to be disclosed is disclosed, and Patent Document 3 or the like also discloses an anisotropic conductive sheet having a step formed between the surface of the conductive path forming portion and the insulating portion. Is disclosed.

Among the anisotropic conductive elastomer sheets, the conductive anisotropic conductive sheet has a conductive path forming portion formed according to a pattern corresponding to the pattern of the electrode to be connected, and an insulating portion is formed between the adjacent conductive path forming portions. Compared with the electroconductive sheet, even if the electrode to be connected is arrange | positioned with a small pitch, it is advantageous at the point which can achieve reliable electrical connection.

In order to manufacture such a ubiquitous anisotropically conductive sheet, a special die for producing an anisotropically conductive sheet having a configuration shown in FIG. 10 has been used in the past. The mold for producing an anisotropic conductive sheet is configured such that the upper mold 90 and the lower mold 95 paired with each other are disposed so that the respective molding surfaces face each other, and the molding surface of the upper mold 90 (lower surface in FIG. 10) and the mold. The cavity is formed between the shaping | molding surface (upper surface in FIG. 10) of the lower mold | type 95. FIG. In the upper die 90, a ferromagnetic layer 92 is formed on the bottom surface of the ferromagnetic substrate 91 in accordance with a pattern symmetrical to the arrangement pattern of the conductive path forming portion of the anisotropic conductive sheet to be produced. In portions other than 92, the weak magnetic layer 93 is formed. On the other hand, in the lower mold 95, the ferromagnetic layer 97 is formed on the upper surface of the ferromagnetic substrate 96 in accordance with the same pattern as the arrangement pattern of the conductive path forming portion of the anisotropic conductive sheet to be produced, and the ferromagnetic layer 97 In other portions, the weak magnetic layer 98 is formed.

Moreover, using this mold for manufacturing an anisotropic conductive sheet, a ubiquitous anisotropic conductive sheet is obtained as follows.

First, as shown in FIG. 11, the electroconductive material layer 80 in which the electroconductive particle P which shows magnetism is disperse | distributed in the polymer forming material which hardens | cures and becomes an elastic polymer material is formed in the mold for anisotropic conductive sheet manufacture. Next, by placing a pair of electromagnets (not shown) on the upper surface of the upper mold 90 and the lower surface of the lower mold 95 and operating them, the ferromagnetic layer 92 and the lower mold of the upper mold 90 in the conductive material layer 80 are operated. A magnetic field having a greater intensity than that of other portions is applied to a portion located between the ferromagnetic layer layers 97 of 95. As a result, the conductive particles P dispersed in the conductive material layer 80 are formed between the ferromagnetic layer 92 of the upper mold 90 and the ferromagnetic layer 97 of the lower mold 95, that is, the conductive path is formed. It is oriented so as to gather in the part to be added and to arrange in the thickness direction at the same time. And the uneven type anisotropic conductive sheet is obtained by hardening the electroconductive material layer 80 in this state.

However, it turns out that there exist the following problems in the conventional mold for manufacturing an anisotropic conductive sheet.

(1) In the step of applying a magnetic field to the conductive material layer 80, the ferromagnetic substrates 91 and 96 themselves function as magnetic poles, so that the weak magnetic layer 93 also becomes a part of the insulating portion of the conductive material layer 80. Since the magnetic field acts through the 98, the conductive particles P present in the portion to be the insulating portion in the conductive material layer 80 tend to remain without moving toward the portion to be the conductive path forming portion. As a result, not only the insulation part which has required insulation is formed, but the electrically-conductive path forming part containing the required amount of electroconductive particle P is not formed reliably, and therefore, it becomes difficult to obtain the anisotropic conductive sheet which shows the desired electroconductivity. This phenomenon is more remarkable as the pitch of the conductive path forming portion is smaller.

(2) In order to manufacture an anisotropic conductive sheet exhibiting high conductivity at a small pressing force, a chain of conductive particles is formed in a thickness direction, that is, a direction perpendicular to the surface of the conductive material layer in a step of applying a magnetic field to the conductive material layer. It is important.

By the way, in the conductive material layer before applying the magnetic field, since the conductive particles are present in the state dispersed uniformly in the conductive material layer, even if the magnetic field is applied in the thickness direction of the conductive material layer, as shown in FIG. The chain of particles P is formed not only in the thickness direction of the conductive material layer 80 but also in a direction inclined with respect to the thickness direction. In addition, in this state, since the magnetodynamically stable and each conductive particles are constrained by the magnetic force, the conductive particles do not move to form a chain in the thickness direction even if the magnetic field is continuously applied. And since the conductive material layer 80 hardens | cures in this state, since the chain | strand of electroconductive particle is formed in the direction inclined with respect to the thickness direction, it becomes difficult to obtain high electroconductivity by small pressing force.

In addition, when the magnetic field is applied to the conductive material layer 80, the other conductive particles P are connected to the conductive particles P staying in the portion to be the insulating portion, so that the ferromagnetic body of the upper die 90 is shown in FIG. A chain of conductive particles P is formed between the layer 92 and the corresponding ferromagnetic layer 97 adjacent to the ferromagnetic layer 97 of the lower mold 95, and as a result, a necessary link between adjacent conductive path forming portions is required. It becomes difficult to obtain the anisotropic conductive sheet which ensures insulation. This phenomenon is more remarkable as the pitch of the conductive path forming portion is smaller.

In order to solve this problem, the Applicant stops the action of the magnetic field on the conductive material layer in the process of applying the magnetic field to the conductive material layer, and then again the magnetic flux line direction is reverse to the conductive material layer. The manufacturing method of the anisotropically conductive sheet | seat which acts a magnetic field was proposed (refer Japanese Patent Application 2004-30180 specification).

According to this manufacturing method, since the action of the magnetic field on the conductive material layer is once stopped, each conductive particle in the conductive material layer is released from restraint by the magnetic force in this stopped state. Then, the magnetic field in which the magnetic flux line direction is reversed in the thickness direction with respect to the conductive material layer is again acted, so that this operation is promoted and the movement of the conductive particles is started again, so that the conductive material layer is conductive in a more faithful direction with respect to the thickness direction of the conductive material layer. A chain of particles is formed.

However, in this manufacturing method, the ferromagnetic substrates of the upper mold and the lower mold of the mold for producing an anisotropic conductive sheet are moved by the magnetic force when a magnetic field in which the magnetic flux line direction is reversed is applied to the conductive material layer. As shown in Fig. 2, positional shifts occur between the upper mold and the lower mold. Therefore, in the obtained anisotropic conductive sheet, as a result of the formation of the conductive path forming portion extending in the direction inclined with respect to the thickness direction thereof, it becomes difficult to obtain the desired conductivity. In addition, when the ferromagnetic substrates of the upper mold and the lower mold are moved, air enters the mold for producing the anisotropic conductive sheet, and thus there is a problem that bubbles are easily generated in the resulting anisotropic conductive sheet.

Patent Document 1: Japanese Patent Laid-Open No. 51-93393

Patent Document 2: Japanese Patent Laid-Open No. 53-147772

Patent Document 3: Japanese Unexamined Patent Publication No. 61-250906

<Start of invention>

This invention is made | formed based on the above circumstances, The 1st objective is the anisotropic electroconductivity for manufacturing the anisotropically conductive sheet which has a some electrically conductive path forming part containing electroconductive particle, and the insulating part which insulates these electrically conductive path forming parts mutually. In the mold for sheet production, even if the pitch of the conductive path forming portion to be formed is small, it is possible to manufacture an anisotropic conductive sheet having conductive path forming portions exhibiting desired electroconductivity and reliably obtaining required insulation between adjacent conductive path forming portions. It is providing the mold for anisotropic conductive sheet manufacture.

A second object of the present invention is a method of manufacturing an anisotropic conductive sheet having a plurality of conductive path forming portions containing conductive particles and an insulating portion insulating the conductive path forming portions, wherein the pitch of the conductive path forming portions to be formed is small. It is an object of this invention to provide the manufacturing method of the anisotropically conductive sheet which has the electrically conductive path formation part which shows desired electroconductivity, and acquires the required insulation reliably between adjacent electrically conductive path formation parts.

The mold for producing an anisotropic conductive sheet of the present invention comprises a plurality of conductive path forming portions containing conductive particles exhibiting magnetism in the insulating elastic polymer material in a state oriented in the thickness direction and an insulating elastic polymer material insulating the conductive path forming portions from each other. It is a type for manufacturing an anisotropic conductive sheet for manufacturing the anisotropic conductive sheet which has an insulation part,

Having a substrate and a ferromagnetic layer disposed on the substrate corresponding to the pattern corresponding to the pattern of the conductive path forming portion,

The substrate is made of a weak magnetic material.

The mold for producing an anisotropic conductive sheet of the present invention forms a conductive material layer containing conductive particles in a liquid polymer forming material that is cured and becomes an insulating elastic polymer material in the mold for producing an anisotropic conductive sheet, and with respect to the conductive material layer, Having a step of aligning conductive particles in a portion of the conductive material layer and aligning the conductive material layer in a thickness direction by applying a magnetic field in the thickness direction of the conductive material layer through the ferromagnetic layer in the mold for producing an anisotropic conductive sheet. In this step, after stopping the action of the magnetic field on the conductive material layer, it can be preferably used for a method for producing an anisotropic conductive sheet in which an operation of applying the magnetic field to the conductive material layer is performed one or more times.

In the mold for producing an anisotropic conductive sheet of the present invention, the substrate is preferably made of a weak magnetic material having a linear thermal expansion coefficient of 1 × 10 ⁻⁷ to 1 × 10 ⁻⁵ K ⁻¹ .

Moreover, it is preferable that the metal film is formed in the surface of a board | substrate.

The method for producing an anisotropic conductive sheet of the present invention includes a plurality of conductive path forming portions containing conductive particles exhibiting magnetism in the insulating elastic polymer material in a state oriented in the thickness direction, and an insulating elastic polymer material insulating the conductive path forming portions from each other. It is a method of manufacturing the anisotropic conductive sheet which has an insulation part which consists of,

Using the said anisotropic conductive sheet manufacturing mold,

In this mold for producing an anisotropic conductive sheet, a conductive material layer containing conductive particles is formed in a liquid polymer forming material that is cured to become an insulating elastic polymer material, and the conductive material layer is formed in the mold for producing an anisotropic conductive sheet. It has a process of gathering electroconductive particle in the part which becomes the said conductive path formation part by orienting a magnetic field in the thickness direction of the said conductive material layer through a ferromagnetic layer, and orienting it in the thickness direction of the said conductive material layer,

In this step, after stopping the action of the magnetic field on the conductive material layer, the operation of applying the magnetic field to the conductive material layer again is performed one or more times.

In the manufacturing method of the anisotropic conductive sheet of this invention, after stopping the action of the magnetic field with respect to a conductive material layer, in the operation which makes a magnetic field with respect to the said conductive material layer again, the magnetic field direction of a magnetic field made to act again on a conductive material layer It is preferable that it is reverse to the direction of the magnetic flux lines of the magnetic field before stopping.

Moreover, in the manufacturing method of the anisotropically conductive sheet of this invention, after stopping the operation | movement of the magnetic field with respect to a conductive material layer, it is preferable to repeat operation to apply a magnetic field to the said conductive material layer again.

Moreover, after stopping the action of the magnetic field on the conductive material layer, it is preferable to perform the operation of applying the magnetic field to the conductive material layer again five or more times.

According to the mold for producing an anisotropic conductive sheet of the present invention, since the substrate is made of a weak magnetic material, when the magnetic field is applied to the conductive material layer, the strength of the magnetic field acting on the portion that becomes the insulating portion in the conductive material layer is determined. Since it can be made small enough, the electroconductive particle which exists in the part used as the said insulating part is reliably gathered in the part used as a conductive path formation part, and as a result, the insulating part which electroconductive particle does not exist at all or hardly exists can be formed, and it is necessary The conductive path formation part containing a positive electroconductive particle can be formed. Therefore, even if the pitch of the electrically conductive path formation part to be formed is small, it can manufacture the anisotropic conductive sheet which has the electrically conductive path formation part which shows desired electroconductivity, and acquires the required insulation reliably between adjacent conductive path formation parts.

Moreover, when stopping the action of the magnetic field with respect to a conductive material layer in the process of making a magnetic field act on a conductive material layer, when using for the manufacturing method of the anisotropically conductive sheet which makes a magnetic field react with the said conductive material layer again, a conductive material layer Even when a magnetic field having a reverse magnetic flux line direction is applied to the ferromagnetic substrate, the ferromagnetic substrate does not move and thus no displacement occurs, thereby forming a conductive path forming portion extending in a faithful direction with respect to the thickness direction. The anisotropically conductive sheet | seat which has a conductive path formation part which shows electroconductivity can be manufactured. In addition, since air is prevented from entering into the mold for producing an anisotropic conductive sheet, it is possible to suppress generation of defective products due to bubbles.

According to the manufacturing method of the anisotropically conductive sheet | seat of this invention, since the action | action of the magnetic field with respect to a conductive material layer is stopped once, each electroconductive particle in a conductive material layer is free | released by the magnetic force in this stopped state. In addition, since the magnetic field is applied to the conductive material layer in the thickness direction again, this operation is promoted and the movement of the conductive particles is started again, so that the chains of the conductive particles are formed in a direction more faithful to the thickness direction of the conductive material layer. .

Thus, since formation of the chain | strand of electroconductive particle in the direction inclined with respect to the thickness direction can be suppressed, the anisotropic conductive sheet which has low electrical resistance value and shows stable electroconductivity can be manufactured even if it pressurizes with a small pressing force.

Moreover, since formation of the chain | strand of electroconductive particle like connecting between adjacent conductive path forming parts is prevented, even if the pitch of a conductive path forming part is small, the anisotropy which reliably obtains the required insulation between adjacent conductive path forming parts is reliably obtained. An electroconductive sheet can be manufactured.

In addition, since the substrate for the anisotropic conductive sheet production type is made of a weak magnetic material, the ferromagnetic substrate does not move even when a magnetic field having a reverse magnetic flux line direction is applied to the conductive material layer, and thus no displacement occurs. The conductive path forming part extending in the faithful direction with respect to the thickness direction can be formed, and therefore, the anisotropic conductive sheet which has the conductive path forming part which shows desired electroconductivity can be manufactured. In addition, since air is prevented from entering into the mold for producing an anisotropic conductive sheet, it is possible to suppress generation of defective products due to bubbles.

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing for description which shows the structure in an example of the anisotropically conductive sheet obtained by the mold for manufacturing an anisotropically conductive sheet of this invention.

It is sectional drawing for explanatory drawing which expands and shows the principal part of the anisotropically conductive sheet | seat shown in FIG.

It is sectional drawing for description which shows the structure of the mold for manufacturing an anisotropic conductive sheet used in order to manufacture the anisotropic conductive sheet shown in FIG.

It is sectional drawing for description which shows the state in which the electroconductive material was apply | coated to the molding surface of the upper mold | type and lower mold | type of the mold for anisotropic conductive sheet manufacture shown in FIG.

It is sectional drawing for description which shows the state in which the conductive material layer was formed in the cavity of the type | mold for anisotropic conductive sheet manufacture.

It is sectional drawing for description which shows the state in which the mold for anisotropic conductive sheet manufacture was set to the electromagnet apparatus.

7 is an explanatory cross-sectional view showing a magnetic flux line direction of a magnetic field before stopping.

8 is an explanatory cross-sectional view showing a magnetic flux line direction of a magnetic field again acted on.

It is sectional drawing for description which shows the state in which the electroconductive particle in the electroconductive material layer gathered in the part used as a conductive path formation part, and is orientated so that it may be arranged in the thickness direction.

It is sectional drawing for description which shows the structure in an example of the conventional mold for manufacturing anisotropic conductive sheets.

FIG. 11: is sectional drawing for description which shows the state in which the conductive material layer was formed between the upper mold | type and lower mold | die in the mold for anisotropic conductive sheet manufacture shown in FIG.

It is explanatory sectional drawing which shows the state in which the chain of electroconductive particle in the electroconductive material layer was formed in the direction inclined with respect to the thickness direction.

FIG. 13 is an explanatory cross-sectional view showing a state where a chain of conductive particles is formed between an upper ferromagnetic layer and a ferromagnetic layer adjacent to a lower ferromagnetic layer corresponding thereto. FIG.

It is sectional drawing for description which shows the state which position shift generate | occur | produced between an upper mold | type and a lower mold | type.

<Explanation of symbols for the main parts of the drawings>

10 anisotropic conductive sheet

10A conductive material layer

11 conductive path formation part

12 insulation

13, 14 protrusions

15 frame board

50 pictographs

51 boards

52 Ferromagnetic Layer

52a recess for protrusion

53 weak magnetic layer

53a cavity recessed

55 Bottom

56 boards

57 Ferromagnetic Layer

57a recess for protrusion

58 weak magnetic layer

58a cavity recessed

60 electromagnet devices

61 upper electromagnet

62 stimuli

65 Lower Electromagnet

66 stimuli

80 conductive material layer

90 Pictographs

91 Ferromagnetic Substrate

92 Ferromagnetic Layer

93 weak magnetic layer

95 Bottom

96 Ferromagnetic Substrate

97 Ferromagnetic Layer

98 weak magnetic layer

P conductive particles

E elastomeric material

Best Mode for Carrying Out the Invention

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described in detail.

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing for description which shows the structure in an example of the anisotropically conductive sheet obtained by the mold for manufacturing an anisotropically conductive sheet of this invention.

The anisotropically conductive sheet 10 is provided with a plurality of conductive path forming portions 11 which extend in the thickness direction, respectively, disposed in accordance with a pattern corresponding to a pattern of an electrode to be connected, for example, an inspected electrode of a circuit device to be inspected. And the insulating portion 12 which insulates these conductive path forming portions 11 from each other. As shown in an enlarged view in FIG. 2, each of the conductive path forming portions 11 is contained in the insulating elastic polymer material E so as to be oriented so that the conductive particles P are arranged in the thickness direction, and is pressed in the thickness direction. The conductive path by the chain of electroconductive particle P in the thickness direction is formed. In the example shown, the protrusions 13 and 14 which protrude from each of both surfaces of the insulating part 12 are formed in each of the electrically conductive path forming parts 11. In contrast, the insulating portion 12 includes an insulating elastic polymer material and contains little or no conductive particles P, and exhibits no conductivity in the thickness direction and the surface direction.

In the anisotropic conductive sheet of this example, the frame-shaped frame plate 15 is provided integrally with the peripheral portion of the insulating portion 12.

Here, the content rate of the electroconductive particle P in the electrically conductive path formation part 11 is 10 to 60% by volume fraction, It is preferable that it is 15 to 50% preferably. When this ratio is less than 10%, the electrically conductive path forming part 11 with a small electric resistance value may not be obtained. On the other hand, when this ratio exceeds 60%, the conductive path forming part 11 obtained easily becomes fragile and the elasticity required as the conductive path forming part 11 may not be obtained.

In addition, although the pitch of the electrically conductive path formation part 11 is 60-500 micrometers, for example, when manufacturing the anisotropically conductive sheet | seat 10 whose pitch is 200 micrometers or less, the manufacturing method of this invention is very effective.

It is sectional drawing for description which shows the structure in an example of the mold for anisotropic conductive sheet manufacture of this invention. The mold for producing an anisotropic conductive sheet is configured such that the upper mold 50 and the lower mold 55 paired with each other are disposed so that the respective molding surfaces face each other, and the molding surface of the upper mold 50 (lower surface in FIG. 3) and the mold. The cavity is formed between the shaping | molding surface (upper surface in FIG. 3) of the lower mold | type 55. As shown in FIG.

In the upper mold 50, a ferromagnetic layer 52 is formed according to a pattern symmetrical with the arrangement pattern of the conductive path forming portion 11 of the anisotropic conductive sheet 10 to be manufactured on the lower surface of the substrate 51, and the ferromagnetic layer In portions other than 52, a weak magnetic layer 53 having a thickness larger than that of the ferromagnetic layer 52 is formed, whereby the ferromagnetic layer 52 at the forming surface of the upper mold 50 is located. The recessed part 52a for protrusion parts for forming the protrusion part 13 in the anisotropically conductive sheet | seat 10 is formed in the part. In addition, a cavity recess 53a for forming a cavity is formed on the surface of the weak magnetic layer 53.

On the other hand, in the lower mold 55, the ferromagnetic layer 57 is formed on the upper surface of the substrate 56 according to the same pattern as the arrangement pattern of the conductive path forming portion 11 of the anisotropic conductive sheet 10. A portion other than the layer 57 is formed with a nonmagnetic layer 58 having a thickness greater than that of the ferromagnetic layer 57, whereby the ferromagnetic layer 57 at the molding surface of the lower mold 55 is located. The recessed part 57a for protrusion parts for forming the protrusion part 14 in the anisotropically conductive sheet | seat 10 is formed in the part. Further, the recessed portion 58a for the cavity for forming the cavity is formed on the surface of the weak magnetic layer 58.

A weak magnetic material is used as the material constituting the substrates 51 and 56 in each of the upper mold 50 and the lower mold 55. The weak magnetic material may be either paramagnetic material or diamagnetic material. Specific examples of the weak magnetic material include ceramics such as alumina, beryllia, silicon carbide, aluminum nitride, fluorine gold mica, glass materials such as blue glass, flint glass, and Pyrex glass, and copper. And weak magnetic metal materials such as aluminum, tungsten and molybdenum.

In addition, when the connection object of the target anisotropic conductive sheet is an integrated circuit or the like formed on the wafer, the substrate anisotropic conductive sheet requires high dimensional accuracy and a high positional accuracy of the conductive path forming portion. As the weak magnetic material constituting the present invention, it is preferable to use a linear thermal expansion coefficient of 1 × 10 ⁻⁷ to 1 × 10 ⁻⁵ K ⁻¹ . Examples of such weak magnetic materials include alumina (4.8 × 10 ⁻⁶ K ⁻¹ ), beryllia (4.3 × 10 ⁻⁶ K ⁻¹ ), silicon carbide (3.7 × 10 ⁻⁶ K ⁻¹ ), and aluminum nitride (4.5 × 10 ⁻⁶ K ⁻¹ ), fluorine gold mica (8.0 × 10 ⁻⁶ K ⁻¹ ), blue glass (8 × 10 ⁻⁶ to 10 × 10 ⁻⁶ K ⁻¹ ), printed glass (as a glass material) 8 x 10 ^-6 to 9 x 10 ^-6 K ^-1 ), Pyrex (registered trademark) glass (2.8 x 10 ^-6 K ^-1 ), tungsten (4.8 x 10 ^-6 K ^-1 ), molybdenum ( 5.6 × 10 ⁻⁶ K ⁻¹ ).

In addition, the substrates 51 and 56 preferably have a thickness of 0.1 to 50 mm, a surface that is smooth, chemically degreased, and preferably mechanically polished.

In addition, since the ferromagnetic layers 52 and 57 can be easily formed on the surfaces of the substrates 51 and 56 by electroplating, a plurality of metal films of different types or single types (not shown). It is preferable that this is formed.

The material for forming the metal film may be a weak magnetic material or a ferromagnetic material, and specific examples thereof include copper, nickel, cobalt, gold, silver, palladium, rhodium, platinum and the like.

As the means for forming the metal film, an electroless plating method can be used.

In addition, in the case of using a ferromagnetic material as a material for forming the metal film, the thickness of the metal film is preferably 30 µm or less, more preferably 20 µm or less from the viewpoint of suppressing the influence of the magnetic field. If the thickness is too thick, the substrates 51 and 56 move when the magnetic field in the magnetic flux line direction is reversed with respect to the conductive material layer in the method for producing an anisotropic conductive sheet described later, thereby moving the upper mold. It is not preferable because there is a risk of positional displacement between the 50 and the lower mold 55.

As a material which comprises the ferromagnetic layers 52 and 57 in each of the upper mold | type 50 and the lower mold | type 55, iron, iron-nickel alloy, iron-cobalt alloy, nickel, cobalt, nickel-cobalt alloy, etc. Ferromagnetic metal of can be used. It is preferable that the thickness of these ferromagnetic layers 52 and 57 is 10 micrometers or more. When this thickness is less than 10 micrometers, it becomes difficult to apply the magnetic field which has sufficient intensity distribution with respect to the conductive material layer formed in the mold for anisotropic conductive sheet manufacture, As a result, the conductive path forming part in the said conductive material layer is formed. Since it becomes difficult to collect electroconductive particle in high density in the part which should be made, the sheet which has favorable anisotropic conductivity may not be obtained.

As the method of forming the ferromagnetic layers 52 and 57 on the surfaces of the substrates 51 and 56, an electroplating method can be used.

In addition, as a material which comprises the weak magnetic body layers 53 and 58 in each of the upper mold | type 50 and the lower mold | type 55, the weak magnetic metals, such as copper, the polymeric material which has heat resistance, etc. can be used, It is preferable to use a polymer material cured by electromagnetic waves in that the weak magnetic layers 53 and 58 can be easily formed by a photolithography method, and examples thereof include acrylic dry film resists, Photoresist, such as an epoxy liquid resist and a polyimide liquid resist, can be used.

In addition, by using the mold for producing an anisotropic conductive sheet,

Step (a-1) of forming a conductive material layer containing conductive particles in a liquid polymer forming material that is cured and becomes an insulating elastic polymer material in the mold for producing an anisotropic conductive sheet, and the anisotropic conductivity with respect to the conductive material layer. Step (b-1) which collects electroconductive particle in the part which becomes the said conductive path formation part, and orients in the thickness direction of the said conductive material layer by acting in the thickness direction of the said conductive material layer through the ferromagnetic body layer in a sheet | seat for manufacturing a sheet, and ,

Step (c-1) of curing the conductive material layer after stopping the action of the magnetic field with respect to the conductive material layer or continuing the action of the magnetic field.

The anisotropic conductive sheet 10 is manufactured via the above.

Hereinafter, each process is demonstrated concretely.

Process (a-1):

In the step (a-1), first, the conductive material is produced by dispersing the conductive particles in a liquid polymer material-forming material that is cured and becomes an insulating elastic polymer material.

Various polymers may be used as the material for forming the conductive material, and specific examples thereof include silicone rubber, polybutadiene rubber, natural rubber, polyisoprene rubber, styrene-butadiene copolymer rubber, acrylonitrile-butadiene copolymer rubber Conjugated diene rubbers such as these, hydrogenated additives thereof, block copolymer rubbers such as styrene-butadiene-diene block copolymer rubbers and styrene-isoprene block copolymers, and hydrogenated additives thereof, chloroprene rubbers, urethane rubbers, and polyester rubbers And epichlorohydrin rubber, ethylene-propylene copolymer rubber, ethylene-propylene-diene copolymer rubber, soft liquid epoxy rubber and the like.

Among these, silicone rubber is preferable in view of durability, molding processability, electrical characteristics, and the like.

As silicone rubber, what crosslinked or condensed a liquid silicone rubber is preferable. The liquid silicone rubber may be any of a condensation type, an addition type, and a vinyl group or a hydroxyl group. Specifically, dimethyl silicone raw rubber, methyl vinyl silicone raw rubber, methylphenyl vinyl silicone raw rubber, etc. may be mentioned.

Moreover, as an addition type | mold liquid silicone rubber, it hardens | cures by reaction of a vinyl group and Si-H bond, and is a one-component type (one-component type) which consists of polysiloxane containing both a vinyl group and a Si-H bond. It is possible to use both a two-component (two-component) composed of a polysiloxane containing a vinyl group and a polysiloxane containing a vinyl group and a Si-H bond, but it is preferable to use a two-component addition liquid silicone rubber.

Among them, the liquid silicone rubber containing a vinyl group (vinyl group-containing polydimethylsiloxane) is usually subjected to hydrolysis and condensation reaction of dimethyldichlorosilane or dimethyldiakoxysilane in the presence of dimethylvinylchlorosilane or dimethylvinylalkoxysilane. For example, it is obtained by performing fractionation by repeating the dissolution-precipitation continuously.

In addition, the liquid silicone rubber containing vinyl groups at both ends is subjected to anionic polymerization of a cyclic siloxane such as octamethylcyclotetrasiloxane in the presence of a catalyst, and for example, dimethyldivinylsiloxane is used as a polymerization terminator. It is obtained by appropriately selecting the conditions (for example, the amount of the cyclic siloxane and the amount of the polymerization terminator). Here, as a catalyst of anionic polymerization reaction, alkali, such as tetramethylammonium hydroxide and n-butyl phosphonium hydroxide, these silanolate solutions, etc. can be used, and reaction temperature is 80-130 degreeC, for example.

It is preferable that such vinyl group containing polydimethylsiloxane has the molecular weight Mw (it refers to the standard polystyrene conversion weight average molecular weight, the same below) 10000-400000. In addition, the molecular weight distribution index (refers to the value of the ratio Mw / Mn between the standard polystyrene reduced weight average molecular weight Mw and the standard polystyrene reduced number average molecular weight Mn) is 2 or less from the viewpoint of the heat resistance of the obtained anisotropic conductive sheet 10. It is preferable.

On the other hand, liquid silicone rubber (hydroxyl group-containing polydimethylsiloxane) containing a hydroxyl group is usually hydrolyzed and condensation reaction of dimethyldichlorosilane or dimethyl dialkoxysilane in the presence of dimethylhydrochlorosilane or dimethylhydroalkoxysilane. For example, it is obtained by performing fractionation by repeating the dissolution-precipitation continuously.

In addition, the cyclic siloxane is anionic polymerized in the presence of a catalyst, and other reaction conditions (for example, dimethylhydrochlorosilane, methyldihydrochlorosilane, dimethylhydroalkoxysilane, etc.) are used as a polymerization terminator. And the amount of the cyclic siloxane and the amount of the polymerization terminator) can also be obtained. Here, as a catalyst of anionic polymerization reaction, alkali, such as tetramethylammonium hydroxide and n-butylphosphonium hydroxide, these silanolate solutions, etc. can be used, and reaction temperature is 80-130 degreeC, for example.

Such hydroxyl group-containing polydimethylsiloxane preferably has a molecular weight Mw of 10000 to 40000. Moreover, it is preferable that a molecular weight distribution index is 2 or less from a viewpoint of the heat resistance of the obtained anisotropic conductive sheet 10.

In the present invention, either of the vinyl group-containing polydimethylsiloxane and the hydroxyl group-containing polydimethylsiloxane may be used, or both may be used in combination.

In addition, when manufacturing the anisotropically conductive sheet | seat 10 used for the probe test of a circuit device, a burn-in test, etc., it is a liquid silicone rubber, and the compression permanent deformation in 150 degreeC of its hardened | cured material uses 10% or less. It is preferable, More preferably, it is 8% or less, More preferably, it is 6% or less. When the compressive permanent strain exceeds 10%, permanent deformation is likely to occur in the conductive path forming portion 11 when the anisotropic conductive sheet 10 obtained is repeatedly used many times or repeatedly in a high temperature environment. As a result, confusion arises in the chain of the electroconductive particle of the electroconductive path formation part 11, and it may become difficult to maintain required electroconductivity.

Here, the compression set of hardened | cured material of liquid silicone rubber can be measured by the method based on JISK6249.

Moreover, as liquid silicone rubber, it is preferable to use the thing whose Durometer A hardness in 23 degreeC of the hardened | cured material is 10-60, More preferably, it is 15-60, Especially preferably, it is 20-60. When the durometer A hardness is less than 10, the insulating portion 12 which insulates the conductive path forming portion 11 from each other when pressed is liable to be excessively deformed, and maintains the required insulation between the conductive path forming portions 11. It may be difficult to do this. On the other hand, when this durometer A hardness exceeds 60, since the pressing force by a considerably large load is needed in order to provide an appropriate deformation | transformation to the electrically-conductive path forming part 11, for example, an inspection object will be deformed or broken. Easier

Here, the durometer A hardness of the liquid silicone rubber cured product can be measured by a method according to JIS K6249.

Moreover, as liquid silicone rubber, it is preferable to use the thing whose tearing strength in 23 degreeC of the hardened | cured material is 8 kN / m or more, More preferably, it is 10 kN / m or more, More preferably, it is 15 kN / m or more, Especially preferable Preferably 20 kN / m or more. When this tear strength is less than 8 kN / m, when excessive strain is added to the anisotropic conductive sheet 10, durability will fall easily.

Here, the tear strength of the liquid silicone rubber cured product can be measured by the method according to JIS K6249.

In addition, it is preferable to use the thing of the viscosity at 23 degreeC as 100-1,250 Pa.s as liquid silicone rubber, More preferably, it is 150-800 Pa.s, Especially preferably, it is 250-500 Pa.s . When this viscosity is less than 100 Pa.s, the electroconductive particle in the said liquid silicone rubber tends to sediment in the electroconductive material obtained, and favorable storage stability is not obtained, and thickness is made to the electroconductive material layer in the process (b-1) mentioned later. When a magnetic field is made to act in the direction, it may become difficult to form a chain | strand of electroconductive particle in a uniform state, because an electroconductive particle is not orientated so that it may arrange in a thickness direction. On the other hand, when this viscosity exceeds 1,250 Pa.s, since the viscosity of the conductive material obtained becomes high, it may become difficult to form a conductive material layer in the mold for anisotropic conductive sheet production, and the magnetic field in the thickness direction in the conductive material layer. Even if it acts, electroconductive particle does not move enough, and it may become difficult to orientate so that electroconductive particle may be arrange | positioned in the thickness direction.

Here, the viscosity of liquid silicone rubber can be measured by a type-B viscometer.

The polymer material forming material may contain a curing catalyst for curing the polymer material forming material. As such a curing catalyst, organic peroxides, fatty acid azo compounds, hydrosilylation catalysts and the like can be used.

Specific examples of the organic peroxide used as the curing catalyst include benzoyl peroxide, bisdicyclobenzoyl peroxide, dicumyl peroxide, and butyl peroxide.

Specific examples of the fatty acid azo compound used as the curing catalyst include azobisisobutyronitrile and the like.

Specific examples of those which can be used as catalysts for hydrosilylation reactions include chloroplatinic acid and salts thereof, platinum-unsaturated group-containing siloxane complexes, complexes of vinylsiloxane and platinum, complexes of platinum and 1,3-divinyltetramethyldisiloxane, Known such as triorganophosphine or phosphite and platinum complex, acetylacetate platinum chelate, and cyclic diene and platinum complex are mentioned.

Although the usage-amount of a hardening catalyst is suitably selected in consideration of the kind of polymeric material formation material, the kind of curing catalyst, and other hardening treatment conditions, it is 3-15 weight part normally with respect to 100 weight part of polymeric material formation materials.

The polymeric material forming material may contain inorganic fillers such as conventional silica powder, colloidal silica, aerogel silica, alumina and the like. Thixotropy of the conductive material obtained by containing such an inorganic filler is ensured and the viscosity thereof is increased, and further, the dispersion stability of the conductive particles P is improved and the strength of the anisotropic conductive sheet 10 obtained by curing treatment is increased. Increases.

Although the usage-amount of such an inorganic filler is not specifically limited, It is unpreferable, when using a large amount, since the movement of the electroconductive particle P by a magnetic field is largely inhibited in the process (b-1) mentioned later.

As the conductive particles for producing the conductive material, those exhibiting magnetic properties are used. Specific examples thereof include metal particles exhibiting magnetic properties such as iron, nickel, and cobalt, alloy particles thereof, particles containing these metals, or cores thereof. The core particles are formed by applying particles having good conductivity such as gold, silver, palladium, and rhodium to the surface of the core particles, or inorganic material particles or polymer particles such as weak magnetic metal particles or glass beads as core particles. The surface of particle | grains was plated with electroconductive magnetic bodies, such as nickel and cobalt, or the core particle was coat | covered with both a conductive magnetic body and the metal with good electroconductivity.

In this, it is preferable to use what used nickel particle as a core particle and the metal plating with favorable electroconductivity, such as gold and silver, on the surface.

The means by which the conductive metal is coated on the surface of the core particle is not particularly limited, but may be performed by, for example, electroless plating.

In the case of using a conductive metal coated on the surface of the core particles as the conductive particles, the coverage of the conductive metal on the particle surface (ratio of the coating area of the conductive metal to the surface area of the core particles) from the viewpoint of obtaining good conductivity. It is preferable that it is 40% or more, More preferably, it is 45% or more, Especially preferably, it is 47 to 95%.

In addition, the coating amount of the conductive metal is preferably 2.5 to 50% by weight of the core particles, more preferably 3 to 30% by weight, still more preferably 3.5 to 25% by weight, particularly preferably 4 to 20% by weight. to be. When the conductive metal to be coated is gold, the coating amount thereof is preferably 3 to 30% by weight of the core particles, more preferably 3.5 to 25% by weight, still more preferably 4 to 20% by weight. When the conductive metal to be coated is silver, the coating amount thereof is preferably 3 to 30% by weight of the core particles, more preferably 4 to 25% by weight, still more preferably 5 to 23% by weight, particularly preferably Is 6 to 20% by weight.

Moreover, it is preferable that the particle diameter of electroconductive particle is 1-500 micrometers, More preferably, it is 2-300 micrometers, More preferably, it is 3-200 micrometers, Especially preferably, it is 5-150 micrometers.

Moreover, it is preferable that the particle size distribution (Dw / Dn) of electroconductive particle is 1-10, More preferably, it is 1-7, More preferably, it is 1-5, Especially preferably, it is 1-4.

Pressurized deformation of the anisotropic conductive sheet 10 obtained by using the electroconductive particle which satisfy | fills these conditions becomes easy, and sufficient between the electroconductive particle P in the conductive path formation part 11 in the said anisotropic conductive sheet 10 is carried out. Electrical contact is obtained.

In addition, the shape of the conductive particles is not particularly limited, but in view of being easily dispersed in the polymer material-forming material, agglomerates of spherical, star-shaped or secondary particles in which these are aggregated are preferable.

Moreover, it is preferable that the moisture content of electroconductive particle is 5% or less, More preferably, it is 3% or less, More preferably, it is 2% or less, Especially preferably, it is 1% or less. By using the electroconductive particle which satisfy | fills these conditions, generation | occurrence | production of the bubble in the said conductive material layer at the time of hardening | curing a conductive material layer in the process (c-1) mentioned later is prevented or suppressed.

Such conductive material is applied to one or both of the upper mold 50 and the lower mold 55 molding surface of the mold for producing an anisotropic conductive sheet shown in FIG. 3 by, for example, a screen printing method, and then shown in FIG. 4. As described above, the upper mold 50 and the lower mold 55 in the mold for producing an anisotropic conductive sheet are superimposed by superimposing the upper mold 50 coated with the conductive material on the lower mold 55 coated with the conductive material via the frame plate 15. The conductive material layer 10A containing the conductive particles P is formed in the polymer material forming material in the cavity therebetween. In this conductive material layer 10A, as shown in FIG. 5, electroconductive particle P is the state disperse | distributed in the said conductive material layer 10A.

As mentioned above, various materials, such as a metal material, a ceramic material, and a resin material, can be used as a material which comprises the frame board 15, The concrete examples thereof are iron, copper, nickel, chromium, cobalt, magnesium, manganese, Metal materials such as metals such as molybdenum, indium, lead, palladium, titanium, tungsten, aluminum, gold, platinum, silver or alloys or alloy steels of two or more thereof, ceramic materials such as silicon nitride, silicon carbide, alumina, aramid nonwoven fabrics Resin materials, such as a reinforced epoxy resin, an aramid nonwoven fabric reinforced polyimide resin, and an aramid nonwoven fabric reinforced bismaleimide triazine resin, are mentioned.

In addition, when manufacturing the anisotropically conductive sheet | seat 10 used for a burn-in test, it is preferable to use the material which comprises the frame board 15 whose linear thermal expansion coefficient is equal to or close to the linear thermal expansion coefficient of the material which comprises the wafer to be tested. desirable. Specifically, when the material constituting the wafer is silicon, it is preferable to use a linear thermal expansion coefficient of 1.5 × 10 ⁻⁴ / K or less, in particular, 3 × 10 ⁻⁶ to 8 × 10 ⁻⁶ / K, Specific examples thereof include an Invar alloy such as Invar, an Elinbar alloy such as Elinbar, a metal material such as superinvar, cobalt, and 42 alloy, and an aramid nonwoven fabric-reinforced organic resin material.

In addition, the thickness of the frame board 15 is 0.02-1 mm, for example, Preferably it is 0.05-0.25 mm.

Process (b-1):

In the step (b-1), the conductive material layer 10A is formed through the ferromagnetic layers 52 and 57 in the mold for producing an anisotropic conductive sheet with respect to the conductive material layer 10A formed in the step (a-1). By acting in the thickness direction of the electroconductive particle in the part which becomes a conductive path formation part, it orientates so that it may be arranged in the thickness direction of the said conductive material layer 10A.

Specifically, as shown in FIG. 6, an electromagnet device 60 having an upper electromagnet 61 and a lower electromagnet 65 and disposed so that each of the magnetic poles 62 and 66 face each other is prepared, and this electromagnet is provided. Between the upper electromagnet 61 magnetic pole 62 and the lower electromagnet 65 magnetic pole 66 of the apparatus 60, the die | dye for manufacturing an anisotropic conductive sheet in which the conductive material layer 10A was formed in the cavity is arrange | positioned. Subsequently, by operating the electromagnet device 60, the non-magnetic layer 53 and the lower mold (50) between the ferromagnetic layer 52 of the upper mold 50 and the ferromagnetic layer 57 of the lower mold 55 corresponding thereto. A stronger magnetic field is formed between the nonmagnetic layers 58 of 55. That is, a magnetic field having a greater intensity than that of other portions is applied to the conductive material layer 10A to become a conductive path forming portion, whereby conductive particles P dispersed in the conductive material layer 10A are transferred to the conductive path. It gathers in the part used as a formation part, and orients so that it may be arranged in the thickness direction of the said conductive material layer 10A.

Here, the magnitude of the magnetic field acting on the conductive material layer 10A is preferably on the order of 0.02 to 2.5 Tesla on average.

In addition, it is preferable that this process (b-1) is performed under conditions which do not accelerate hardening of the conductive material layer 10A, for example, at room temperature.

In addition, in this step (b-1), an operation for stopping the action of the magnetic field on the conductive material layer 10A once and then applying the magnetic field to the conductive material layer 10A again (hereinafter referred to as "reactivation operation"). One or more times). This reactivation operation is specifically performed by stopping the operation of the electromagnet device 60 and then operating the electromagnet device 60 again.

In this reactivation operation, the time from stopping the action of the magnetic field to the conductive material layer 10A and then applying the magnetic field to the conductive material layer 10A (hereinafter referred to as "operation stop time") is the conductive material. Although it sets suitably in consideration of the viscosity of the layer 10A, the ratio of the electroconductive particle in the electroconductive material layer 10A, the average particle diameter of electroconductive particle, etc., it is preferable that it is 200 second or less, More preferably, it is 60 second or less.

If the operation stop time is too long, the time required for the step (b-1) becomes too long, the production efficiency becomes very low throughout the manufacturing process, and the curing of the liquid polymer material forming material is initiated. As a result of the viscosity of 10A) being changed, sufficient effects may not be obtained.

In addition, the magnetic field acting on the conductive material layer 10A again in the reactivation operation may be in the same magnetic flux line direction as that of the magnetic field before stopping, or may be reverse to the magnetic flux line direction of the magnetic field before stopping. However, since the influence of the residual magnetic field is small, it is preferable that the magnetic field is reverse to the direction of the magnetic flux line of the stationary magnetic field.

In addition, when the direction of the magnetic flux lines causes the magnetic field in the opposite direction to the magnetic flux lines of the magnetic field before stopping, the strength of the magnetic field is preferably about the same as that of the magnetic field before stopping.

In order to operate the magnetic field whose direction of the magnetic flux line is opposite to the magnetic flux line direction of the magnetic field before stopping, the polarity of the upper electromagnet 61 magnetic pole 62 of the electromagnet device 60 and the polarity of the lower electromagnet 65 magnetic pole 66 are changed. You can also

Specifically, when the magnetic field is applied to the conductive material layer 10A for the first time, for example, the upper electromagnet 61 magnetic pole 62 becomes the N pole and the lower electromagnet 65 magnetic pole 66 becomes the S pole. The electromagnet apparatus 60 is operated under such conditions. In this state, since the ferromagnetic layer 52 of the upper mold 50 functions as the N pole, and the ferromagnetic layer 57 of the lower mold 55 functions as the S pole, it acts on the conductive material layer 10A as shown in FIG. The direction of the magnetic flux lines in the magnetic field is a direction from the ferromagnetic layer 52 of the upper mold 50 to the ferromagnetic layer 57 of the lower mold 55, that is, the direction from top to bottom. After a predetermined time has elapsed while the magnetic field is applied to the conductive material layer 10A in this manner, the operation of the electromagnet device 60 is once stopped. Thereafter, the electromagnet device 60 is operated again under the condition that the upper electromagnet 61 pole 62 becomes the S pole and the lower electromagnet 65 pole 66 becomes the N pole. In this state, since the ferromagnetic layer 52 of the upper mold 50 functions as the S pole and the ferromagnetic layer 57 of the lower mold 55 functions as the N pole, as shown in FIG. 8, the ferromagnetic layer 52 acts on the conductive material layer 10A. The magnetic flux line direction in the magnetic field is a direction from the ferromagnetic layer 57 of the lower mold 55 to the ferromagnetic layer 52 of the upper mold 50, that is, from bottom to top.

According to this method, even if a residual magnetic field is generated when the operation of the electromagnet device 60 is stopped, the magnetic field is eliminated by operating the electromagnet device 60 again, so the influence of the residual magnetic field is reduced.

In addition, the reoperation operation can be performed one or more times in the step (b-1), but it is preferable to perform the repetition, specifically, it is preferable that the number of reoperation operations is five or more times, more preferably 10 to 500 times.

If the number of restart operations is too small, there is little chance that each of the conductive particles P in the conductive material layer 10A is freed from the restraint by magnetic force, and thus the opportunity of the movement of the conductive particles P to be started again. Since there are few, the chain | strand of electroconductive particle P becomes difficult to form in a more faithful direction with respect to the thickness direction of 10 A of conductive material layers, and it connects between adjacent conductive path forming parts in the resulting anisotropic conductive sheet. It may become difficult to prevent reliably that the chain | strand of electroconductive particle P is formed.

As described above, in the case where the reoperation operation is repeatedly performed, the time until the magnetic field is applied to the conductive material layer again and the action of the magnetic field on the conductive material layer is stopped (hereinafter referred to as "restart time") is conductive. Although appropriately set in consideration of the viscosity of the material layer 10A, the proportion of the conductive particles in the conductive material layer 10A, the average particle diameter of the conductive particles, and the like, the amount is preferably 10 to 300 seconds, more preferably 10 to 200 seconds. to be.

If the reactivation time is too short, a high-intensity magnetic field is not formed, so that the conductive particles P in the conductive material layer 10A do not sufficiently move, and as a result, in the thickness direction of the conductive material layer 10A. The chain | strand of electroconductive particle P may become difficult to form in a more faithful direction. On the other hand, if the reactivation time is too long, the time required for the step (b-1) becomes too long, the production efficiency becomes very low throughout the manufacturing process, and the curing of the liquid polymer material forming material is started. The viscosity of (10A) may change and a sufficient effect may not be acquired.

As described above, in the step (b-1), as shown in FIG. 9, the portion between the ferromagnetic layer 52 of the upper mold 50 and the ferromagnetic layer 57 of the lower mold 55 corresponding thereto, that is, the conductive path is formed. The conductive material layer 10A densely contained in the state to which the electroconductive particle P was oriented in the thickness direction is formed in the part added.

Process (c-1):

In the step (c-1), a curing treatment is performed on the conductive material layer 10A that is densely contained in a state in which the conductive particles P are oriented in the thickness direction at the portion to be the conductive path forming portion.

The curing treatment of the conductive material layer 10A may be performed after stopping the action of the magnetic field on the conductive material layer 10A, or may be performed while applying the magnetic field to the conductive material layer 10A. It is preferable to carry out while.

In addition, although the hardening process of the conductive material layer 10A differs according to the material used, it is usually performed by heat processing. The specific heating temperature and the heating time are appropriately set in consideration of the kind of the polymer material forming material constituting the conductive material layer 10A and the like.

And after the hardening process of 10 A of electroconductive material layers is complete | finished, it cools to room temperature, for example, and takes out from the mold for manufacturing an anisotropic conductive sheet, and the anisotropic conductive sheet 10 shown in FIG. 1 and FIG. 2 is obtained. .

According to the said anisotropically conductive sheet manufacturing mold and the anisotropically conductive sheet manufacturing method, the following effects are exhibited.

That is, since the board | substrate 51 of the upper mold | type 50 and the board | substrate 56 of the lower mold | type 55 are comprised with the weak magnetic material, respectively, when the magnetic field is applied to the conductive material layer 10A, the said conductive material Since the strength of the magnetic field acting on the portion to be the insulating portion in the layer 10A can be sufficiently reduced, the conductive particles P present in the portion to be the insulating portion are reliably gathered at the portion to be the conductive path forming portion, As a result, the insulating part 12 in which the electroconductive particle P does not exist at all or hardly exist can be formed, and the conductive path forming part 11 containing the required amount of electroconductive particle P can be formed. Therefore, even if the pitch of the conductive path forming part 11 to be formed is small, the anisotropy which has the conductive path forming part 11 which shows desired electroconductivity, and the required insulation between the adjacent conductive path forming parts 11 can be obtained reliably. The conductive sheet 10 can be manufactured.

Further, the substrates 51 and 56 are also subjected to heat treatment for curing the conductive material layer 10A by using a material having the linear thermal expansion coefficient in a specific range as the material constituting the substrates 51 and 56. Because of the small thermal expansion, the anisotropic conductive sheet having high dimensional accuracy of the whole sheet and the positional accuracy of the conductive path forming portion can be produced.

In addition, since the action of the magnetic field on the conductive material layer 10A is once stopped, each of the conductive particles P in the conductive material layer 10A is released from restraint by the magnetic force. Then, the operation is accelerated by applying the magnetic field to the conductive material layer 10A in the thickness direction again, and the movement of the conductive particles P is started again, so that the conductive material layer 10A is in a more faithful direction with respect to the thickness direction of the conductive material layer 10A. Chain of electroconductive particle P is formed.

As described above, since the chain of the conductive particles P can be prevented from being formed in the direction inclined with respect to the thickness direction, the electrical resistance value is low and stable conductivity even when pressurized with a small pressing force, and also between the adjacent conductive path forming portions. Since the chain of electroconductive particle P like connecting is prevented from forming, even if the pitch of the conductive path formation part 11 is small, the anisotropic conductive sheet which can surely obtain the required insulation between adjacent conductive path formation parts 11 is obtained. (10) can be manufactured.

In addition, even when the magnetic field having the opposite magnetic flux line direction is applied to the conductive material layer 10A, the substrate 51 of the upper mold 50 and the substrate 56 of the lower mold 55 do not move by the magnetic force. Therefore, since no position shift occurs between the upper mold 50 and the lower mold 55, the conductive path forming portion 11 extending in a faithful direction with respect to the thickness direction can be formed, and as a result, the conductive exhibiting the desired conductivity The anisotropic conductive sheet 10 which has the furnace forming part 11 can be manufactured. In addition, since air is prevented from entering the mold for producing an anisotropic conductive sheet, generation of defective products due to bubbles can be suppressed.

EMBODIMENT OF THE INVENTION Hereinafter, although the specific Example of this invention is described, this invention is not limited to this.

<Example 1>

(1) Preparation of Mold for Manufacturing Anisotropic Conductive Sheet:

According to the structure shown in FIG. 3, the mold for anisotropic conductive sheet manufacture of the following specification was manufactured.

The upper mold 50 and the lower mold 55 each have substrates 51 and 56 on which a nickel film having a thickness of 3 μm and a copper film having a thickness of 5 μm are formed in this order on the surface of a substrate material made of fluorine gold mica having a thickness of 6 mm, respectively. On the surfaces of the substrates 51 and 56, 2000 rectangular ferromagnetic layers 52 and 57 made of nickel-cobalt are formed by electroplating. The dimensions of each of the ferromagnetic layers 52, 57 are 40 mu m (length) x 100 mu m (width) x 50 mu m (thickness), and the arrangement pitch is 80 mu m. Further, in the regions other than the ferromagnetic layers 52 and 57 formed on the surfaces of the substrates 51 and 56, the weak magnetic layers 53 and 58 on which the dry film resist is hardened are formed. The thickness of the part in which the recessed parts 53a and 58a for cavities in the weak magnetic layers 53 and 58 were formed is 80 micrometers, and the thickness of the other part is 90 micrometers.

(2) Manufacture of frame boards:

The frame board of the following specification was manufactured.

The frame plate is a 42 alloy material and has a rectangular dimension of 250 mm × 250 mm × 0.03 mm, and 100 rectangular openings each having a dimension of 1.6 mm × 0.3 mm are formed side by side in the longitudinal direction.

(3) Step (a-1):

A conductive material was prepared by adding 140 parts by weight of conductive particles having an average particle size of 8.7 μm to 100 parts by weight of the additional liquid silicone rubber, followed by degassing treatment under reduced pressure.

The conductive material is applied to the upper mold forming surface and the lower mold forming surface in the mold for producing an anisotropic conductive sheet by a screen printing method, and then the frame plate and the upper mold are superimposed on the lower mold in this order from the bottom to the cavity between the upper mold and the lower mold. The conductive material layer was formed in the inside.

In the above, as electroconductive particle, what made the nickel particle into a core particle, and electroless-plated to this core particle was given (average coating amount: 25weight% of the core particle weight) was used.

Moreover, as an addition type | mold liquid silicone rubber, it is a two-component type whose viscosity of liquid A is 250 Pa.s, and the viscosity of liquid B is 250 Pa.s, the permanent compression deformation at 150 degreeC of a hardened | cured material is 5%, and the durometer of hardened | cured material The A hardness was 35 and the tear strength of hardened | cured material was 25 kN / m.

In addition, the characteristic of the said addition type | mold liquid silicone rubber and its hardened | cured material was measured as follows.

(i) Viscosity of Additive Liquid Silicone Rubber:

The viscosity in 23 +/- 2 degreeC was measured with the Brookfield viscometer.

(ii) compression set of silicone rubber cured product:

A liquid and B liquid in the two-component addition type liquid silicone rubber were stirred and mixed at a ratio equivalent to that. Subsequently, the mixture was poured into a mold for producing an anisotropic conductive sheet, and the mixture was subjected to a degassing treatment under reduced pressure, followed by curing at 120 ° C. for 30 minutes. A silicone rubber having a thickness of 12.7 mm and a diameter of 29 mm The cylinder containing the hardened | cured material was produced, and post-curing was performed on this cylinder on 200 degreeC and the conditions of 4 hours. Thus, the obtained cylindrical body was used as a test piece, and the compression set at 150 +/- 2 degreeC was measured according to JISK6249.

(iii) tear strength of cured silicone rubber:

A sheet having a thickness of 2.5 mm was prepared by performing curing and post-curing of the additional liquid silicone rubber under the same conditions as in (ii) above. A crescent shaped test piece was produced from this sheet by punching, and the tear strength at 23 ± 2 ° C. was measured according to JIS K6249.

(iv) Durometer A hardness:

Five sheets prepared in the same manner as in (iii) were superimposed, and the obtained hit body was used as a test piece, and the durometer A hardness at 23 ± 2 ° C. was measured in accordance with JIS K 6249.

(4) Step (b-1):

An electromagnet device having an upper electromagnet and a lower electromagnet and arranged so that each magnetic pole was opposed to each other was prepared, and a mold for producing an anisotropic conductive sheet in which the conductive material layer was formed between the upper electromagnet pole and the lower electromagnet pole of the electromagnet device was set. Then, by operating the electromagnet apparatus for 15 seconds at room temperature, a magnetic field of 1.6 T strength is applied to the portion of the conductive material layer to become the conductive path forming portion, and further to the portion of the conductive path forming portion while performing a total of 200 restart operations. Acted as a magnetic field. Here, the condition of the reactivation operation is that the operation stop time is 5 seconds, the restart operation time is 15 seconds, the magnetic flux line direction of the magnetic field to be acted again is the reverse of the magnetic flux line direction of the magnetic field before the stop, When the magnetic field was applied to the portion to be the furnace forming portion, the strength of the magnetic field was 1.6T.

(5) Step (c-1):

By operating the electromagnet apparatus in a state where a mold for producing an anisotropic conductive sheet is set between an upper electromagnet pole and a lower electromagnet pole of the electromagnet device, the magnetic material having a 1.6 T strength is applied to a portion of the conductive material layer to become a conductive path forming portion at 100 ° C. The anisotropically conductive sheet in which the frame plate was integrally provided in the peripheral part of the insulated part was manufactured by carrying out the hardening process of the said electrically-conductive material on the conditions of 2 hours at and then taking out from the mold for manufacturing an anisotropically conductive sheet after cooling to room temperature.

In the obtained anisotropic conductive sheet, 2000 rectangular conductive path forming portions were arranged at a pitch of 80 µm, and the conductive path forming portions each had a horizontal and horizontal dimension of 40 µm x 100 µm, a thickness of 110 µm, and a protrusion height from both sides of the insulating portion 30, respectively. It was micrometer and the thickness of the insulation part was 50 micrometers.

Moreover, when the content rate of the electroconductive particle in a conductive path formation part was investigated, it was about 30% by volume fraction with respect to all the conductive path formation parts.

<Example 2>

According to the structure shown in FIG. 3, the mold for anisotropic conductive sheet manufacture of the following specification was manufactured.

The upper mold 50 and the lower mold 55 each have a nickel film having a thickness of 0.5 μm and a copper film having a thickness of 5 μm formed by sputtering on the surface of a substrate material made of Pyrex (registered trademark) glass having a thickness of 6 mm, respectively. With the substrates 51 and 56, 2000 rectangular ferromagnetic layers 52 and 57 made of nickel-cobalt are formed on the surface of each of the substrates 51 and 56 by electroplating. The dimensions of each of the ferromagnetic layers 52, 57 are 40 mu m (length) x 100 mu m (width) x 50 mu m (thickness), and the arrangement pitch is 80 mu m. Further, in the regions other than the ferromagnetic layers 52 and 57 formed on the surfaces of the substrates 51 and 56, the weak magnetic layers 53 and 58 on which the dry film resist is hardened are formed. The thickness of the part in which the recessed parts 53a and 58a for cavities in the weak magnetic layers 53 and 58 were formed is 80 micrometers, and the thickness of the other part is 90 micrometers.

An anisotropic conductive sheet was produced in the same manner as in Example 1 except that the mold for producing an anisotropic conductive sheet was used.

In the obtained anisotropic conductive sheet, 2000 rectangular conductive path forming portions were arranged at a pitch of 80 µm, and the conductive path forming portions had a vertical and horizontal dimension of 40 µm x 100 µm, a thickness of 110 µm, and the protruding heights from both sides of the insulating portion, respectively. It was 30 micrometers and the thickness of the insulated part was 50 micrometers.

Moreover, when the content rate of the electroconductive particle in a conductive path formation part was investigated, it was about 30% by volume fraction with respect to all the conductive path formation parts.

<Example 3>

According to the structure shown in FIG. 3, the mold for anisotropic conductive sheet manufacture of the following specification was manufactured.

The upper mold | type 50 and the lower mold | type 55 are the board | substrate 51 and 56 in which the nickel film of thickness 0.5micrometer formed by sputtering, and the copper film of thickness 5micrometer formed by sputtering were laminated | stacked on the surface of the board | substrate material which consists of molybdenum of thickness 6mm, respectively, in this order. On the surfaces of each of the substrates 51 and 56, 2000 rectangular ferromagnetic layers 52 and 57 made of nickel-cobalt are formed by electroplating. The dimensions of each of the ferromagnetic layers 52, 57 are 40 mu m (length) x 100 mu m (width) x 50 mu m (thickness), and the arrangement pitch is 80 mu m. Further, in the regions other than the ferromagnetic layers 52 and 57 formed on the surfaces of the substrates 51 and 56, the weak magnetic layers 53 and 58 on which the dry film resist is hardened are formed. The thickness of the part in which the recessed parts 53a and 58a for cavities in the weak magnetic layers 53 and 58 were formed is 80 micrometers, and the thickness of the other part is 90 micrometers. An anisotropic conductive sheet was produced in the same manner as in Example 1 except that the mold for producing an anisotropic conductive sheet was used.

In the obtained anisotropic conductive sheet, 2000 rectangular conductive path forming portions were arranged at a pitch of 80 µm, and the conductive path forming portions had a vertical and horizontal dimension of 40 µm x 100 µm, a thickness of 110 µm, and the protruding heights from both sides of the insulating portion, respectively. It was 30 micrometers and the thickness of the insulated part was 50 micrometers.

Moreover, when the content rate of the electroconductive particle in a conductive path formation part was investigated, it was about 30% by volume fraction with respect to all the conductive path formation parts.

Comparative Example 1

An anisotropic conductive sheet was prepared in the same manner as in Example 1 except that a mold for producing an anisotropic conductive sheet having the same specifications as in Example 1 was prepared except that a 42 alloy, which was a ferromagnetic material, was used. Prepared.

In the obtained anisotropic conductive sheet, 2000 rectangular conductive path forming portions were arranged at a pitch of 80 µm, and the conductive path forming portions had a vertical and horizontal dimension of 40 µm x 100 µm, a thickness of 110 µm, and the protruding heights from both sides of the insulating portion, respectively. It was 30 micrometers and the thickness of the insulated part was 50 micrometers.

Moreover, when the content rate of the electroconductive particle in a conductive path formation part was investigated, it was about 30% by volume fraction with respect to all the conductive path formation parts.

[Evaluation of Anisotropic Conductive Sheet]

The following evaluation was performed about the anisotropically conductive sheet | seat obtained in Examples 1-3 and Comparative Example 1.

Conductivity of conductive path forming part:

In the state which pressed all the conductive path forming parts of the anisotropic conductive sheet so that the strain of the thickness direction might be 20%, the electrical resistance value of each thickness direction of each said conductive path forming part was measured. The results are shown in Table 1.

Insulation between conductive parts:

In the state which pressed all the conductive path forming parts of the anisotropic conductive sheet so that the strain of the thickness direction might be 20%, the electrical resistance value between adjacent conductive path forming parts was measured, and the number of things whose value is less than 1 M (ohm) was calculated | required. The results are shown in Table 1.

As is clear from the results of Table 1, according to Examples 1 to 3, there is a conductive path forming portion having a low electric resistance value and showing stable conductivity even when pressurized with a small pressing force, and the conductive adjacent to all conductive path forming portions. It was confirmed that the anisotropic conductive sheet having required insulation with the furnace forming portion was obtained. In contrast, the anisotropic conductive sheet obtained in Comparative Example 1 has a small electric resistance value with the conductive path forming portion adjacent to a part of the conductive path forming portion, and in this respect, the anisotropic conductive sheet obtained in Examples 1 to 3 and The difference with the anisotropic conductive sheet obtained by the comparative example 1 was inverse.

Claims (8)

A plurality of conductive path forming portions containing conductive particles exhibiting magnetic properties in the insulating elastic polymer material in a state oriented in the thickness direction; And a die for producing an anisotropic conductive sheet for producing an anisotropic conductive sheet having an insulating portion made of an insulating elastic polymer material which insulates the conductive path forming portion from each other. And a ferromagnetic layer disposed on the substrate in accordance with a pattern corresponding to the pattern of the conductive path forming portion, wherein the substrate comprises a weak magnetic material. The method of claim 1, In the mold for producing an anisotropic conductive sheet, a conductive material layer containing conductive particles is formed in a liquid polymer forming material that is cured to become an insulating elastic polymer material, and the ferromagnetic layer in the mold for producing an anisotropic conductive sheet is formed with respect to the conductive material layer. And collecting the conductive particles in a portion which becomes the conductive path forming portion by acting a magnetic field in the thickness direction of the conductive material layer through the orienting in the thickness direction of the conductive material layer, wherein It is used for the manufacturing method of the anisotropically conductive sheet | seat which stops the operation | movement of a magnetic field, and then performs the operation | movement which makes a magnetic field with respect to the said conductive material layer one or more times. The mold for producing an anisotropic conductive sheet according to claim 1 or 2, wherein the substrate is made of a weak magnetic material having a linear thermal expansion coefficient of 1 × 10 ⁻⁷ to 1 × 10 ⁻⁵ K ⁻¹ . The metal film is formed in the surface of a board | substrate, The mold for manufacturing an anisotropic conductive sheet in any one of Claims 1-3 characterized by the above-mentioned. A plurality of conductive path forming portions containing conductive particles exhibiting magnetic properties in the insulating elastic polymer material in a state oriented in the thickness direction; And an insulating portion made of an insulating elastic polymer material which insulates the conductive path forming portion from each other. Using the mold for anisotropic conductive sheet manufacture in any one of Claims 1-4, In the mold for producing an anisotropic conductive sheet, a conductive material layer containing conductive particles is formed in a liquid polymer forming material that is cured to become an insulating elastic polymer material, The conductive material layer is made of the conductive material layer by gathering conductive particles in the conductive path forming portion by applying a magnetic field in the thickness direction of the conductive material layer through the ferromagnetic layer in the mold for producing an anisotropic conductive sheet. Including a step of orienting in the thickness direction of The method of manufacturing an anisotropic conductive sheet, wherein the operation of applying a magnetic field to the conductive material layer is performed one or more times after stopping the action of the magnetic field on the conductive material layer in the step. The magnetic flux line direction of the magnetic field acting on the conductive material layer again in the operation of stopping the action of the magnetic field on the conductive material layer and then acting on the conductive material layer again. It is a reverse direction to a magnetic flux line direction, The manufacturing method of the anisotropic conductive sheet characterized by the above-mentioned. The method for producing an anisotropic conductive sheet according to claim 5 or 6, wherein the operation of applying the magnetic field to the conductive material layer is repeated after stopping the action of the magnetic field on the conductive material layer. The method for producing an anisotropic conductive sheet according to claim 7, wherein the operation of applying the magnetic field to the conductive material layer is further performed five times or more after the action of the magnetic field on the conductive material layer is stopped.

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