JPS6232590B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an anisotropic conductive connector, particularly a 100 μm conductive connector.
This invention relates to a method of manufacturing a low pitch anisotropic conductive connector in which conductive parts are arranged in a matrix at the following pitches:

Conventionally, the method of manufacturing an anisotropic conductive connector in which conductive parts are arranged in a matrix is to laminate a conductive material and an insulating material, cut them in the direction of the lamination to form a striped contact sheet, and then create a striped contact sheet. There is a known method in which an insulating material is layered on top of the substrate, the layers are then layered, and then the layers are sliced again in the direction of the layering (Japanese Patent Application Laid-Open No. 52-29958,
(See U.S. Pat. No. 3,982,320). However, the pitch between the conductive parts of the connector obtained by this method is limited to 0.1 mm due to manufacturing technology, and no product with this spacing of 100 μm or less has been obtained.

On the other hand, a method known for manufacturing this anisotropic conductive connector is to use a liquid conductive rubber material and an insulating rubber material and coat them alternately to obtain a low-pitch connector. It is technically difficult to coat the liquid rubber with a uniform thickness, and this also has the disadvantage that there is a limit to the number of layers that can be layered, as well as the melting process to obtain the liquid rubber and the control of its concentration. However, the use of solvents also had the disadvantage of deteriorating the working environment.

The present invention aims to provide a method for manufacturing an anisotropically conductive connector that solves these disadvantages, which involves adding a thermoplastic material to an unvulcanized conductive rubber material and an unvulcanized insulating rubber material, respectively. A step of kneading and then forming into a sheet, a step of alternately laminating the conductive sheets and insulating sheets obtained in the above step to form a laminated block body A, and a step of cutting this block body A in the lamination direction to form a striped sheet. a step of alternately laminating the striped sheets and insulating rubber material sheets to form a laminated block body B; a step of laminating this block body B in parallel to the laminating direction;
and cutting the striped sheet in a direction intersecting the striped pattern, and after completing at least one of the above steps, the sheet or block obtained in the step is stretched to reduce the pitch interval. According to this feature, it is possible to easily and efficiently manufacture an anisotropically conductive connector having conductive parts arranged at intervals of 100 μm or less and having practical physical strength.

To explain this, the method of the present invention uses a thermoplastic material kneaded with a conductive rubber material and an insulating rubber material constituting the connector, and when this is stretched, a rubber material without the plastic material kneaded is used. While materials contract due to their elasticity, in the case of kneaded plastic materials, the shrinkage is inhibited by the presence of this plastic material, and the dimensions after stretching are maintained as they are even after cooling. This was achieved based on the knowledge of the present inventors that since the pitch is accurately held, the desired pitch reduction of the connector can be easily achieved.

This will be explained based on the attached drawings. The drawings illustrate the case where the striped sheet obtained in the third step is stretched as an example of the method of the present invention. In this case, the insulating rubber material and Sheet 1 made from a mixture of thermoplastic and sheet 2 made from a mixture of conductive rubber and thermoplastic are alternately laminated.
It is vulcanized to form block body A (see FIG. 1). Next, this block body A is cut as shown by dotted lines to obtain a striped sheet 3 having conductive parts in a striped shape (see Fig. 2), which is heated and stretched to form a striped sheet 4 (third section). (see figure). Next, this sheet 4 is laminated alternately with the sheet 5 made of insulating rubber material as shown in FIG. 4 to obtain block B (see FIG. 5), which is shown in the dotted line in the figure. When cut like this, an anisotropic conductive contact 8 is obtained in which the conductive parts 6 are arranged in a matrix in the insulating part 7, and since the striped sheet has been thinned by the previous stretching, the resulting connector is The pitch becomes smaller by the stretching ratio.

In the figure, this stretching step is performed on the striped sheet obtained in the third step, but regardless of whether this stretching is performed in the first, second, fourth, or fifth step, Alternatively, two or more of these steps may be performed depending on the purpose, and in either case, by adding this stretching step, a low pitch anisotropically conductive connector can be easily obtained.

Insulating rubber materials used in the method of the present invention include butadiene, butadiene-styrene, butadiene-acrylonitrile, butadiene-based (co)polymers such as butadiene-isobutylene, chloroprene-based polymers, and polysulfide-based (co)polymers. Examples include polymers, vinyl chloride-vinyl acetate copolymers, polyurethanes, and silicone rubber.
As the conductive rubber material, various conductive materials such as carbon powder, silver, nickel, etc. can be added to this insulating rubber material.
Examples include mixtures of metal powders such as copper, and mixtures of these conductive materials and silica. Among these, silicone rubbers with various rheological properties adjusted by adding fillers such as silica are used for hardening. It is preferred in terms of characteristics and physical properties.

Regarding this silicone rubber, there is a thermosetting type made by blending dimethylpolysiloxane as raw rubber with organic peroxides such as benzoyl peroxide, dicumyl peroxide, and dichloroperoxydicarbonate, and dimethylpolysiloxane as a curing agent. Either a blend with an alkoxysilane or a room temperature vulcanization type in which platinum or a platinum compound as a curing catalyst is blended with vinyl group-containing dimethylpolysiloxane and hydrogen group-containing dimethylpolysiloxane can be used. However, when a thermosetting type is used, its adhesive properties decrease due to thermosetting, so it is necessary to use an adhesive described later for this lamination. When using sulfur-type silicone rubber, if an organic peroxide is used together with it, the silicone rubber that has been pre-cured in the previous heat vulcanization will undergo a curing reaction by the platinum catalyst when heated after lamination, and this Since the bonding between the rubbers is effected by the adhesive, there is an advantage that the adhesive described below is not required.

On the other hand, the thermoplastic material to be blended with this rubber material may have film-forming ability, and the film made from it may be heat-stretchable, such as vinyl chloride, polyethylene, polypropylene, etc. acrylic resin,
Examples include polystyrene, polycarbonate, and silphenylene resin. However, in the method of the present invention, polyolefin materials such as polyethylene and polypropylene are preferable because of their film-forming ability, and high-density polyethylene is particularly preferred from the viewpoint of the physical properties of the molded product. It is good to do. The blending ratio of the thermoplastic plastic and the rubber substance is preferably in the range of 5 to 40 parts by weight, preferably 10 to 20 parts by weight, of the plastic substance per 100 parts by weight of the rubber substance. This may be carried out using a known heating kneading roll, Banbury mixer, etc., and this method is not particularly limited.

The mixture of rubber material and plastic material thus obtained is then formed into a sheet, and the method of the present invention is particularly aimed at obtaining a low-pitch anisotropically conductive connector. For this reason, it is necessary to keep the pitch to 0.1 mm or less, and from this point of view, when forming the sheet, it is preferable to roll it out or topping it with a calender roll. The sheet thus obtained is transferred as it is to the next step, which is preferably pre-vulcanized by heating under pressure for 3 to 5 minutes at 170°C and 20 kg/cm ² . It is better to send it to the process.

The insulating rubber sheet and conductive rubber sheet thus obtained are then laminated, and a plurality of these sheets are further laminated to form the block body A. Either the two types of rubber materials are topped on a plastic member such as a polyester film, and then the plastic member is peeled off, and these are laminated, or the rubbery surfaces are bonded and laminated, and then the plastic member is peeled off. You may also adopt the method of In addition, when this sheet is already pre-vulcanized in the previous stage, it is recommended to use an adhesive as necessary for this lamination, such as millable vulcanization. toluene solution, as silicone adhesive
Examples include KE-1800RTV (manufactured by Shin-Etsu Chemical Co., Ltd.), and these may be appropriately selected depending on the type of rubber substance used as the starting material.

In addition, this block formation is performed by pressurizing and heating this laminate, but for peroxide-containing products, 150 to 200℃ and 3 to 35 kg/cm ²
It is sufficient to heat the product under pressure for up to 16 hours, and for the above-mentioned room temperature vulcanization molded product, a low temperature such as 50 to 100°C may be used.

As a result, the rubber substance is completely vulcanized, and this vulcanized block body A is then cut into striped sheets in the stacking direction, and the slice width is approximately 50 to 50 mm.
It may be 300 μm.

This striped sheet is further laminated with an insulating rubber material, but it is not necessary to specifically incorporate a plastic material into this insulating rubber, and the laminated layer is rolled out and topped to a thickness of 0.1 mm or less. This laminated sheet is further laminated to form a block B, which is made up of, for example, 160~
By pressing for several minutes at 200°C and 3 to 15 kg/cm ² , and then cutting to the desired thickness of the connector parallel to the lamination direction and intersecting the striped pattern of the striped portion. It is considered an anisotropic conductive connector.

In the method of the present invention, this is stretched in one or more of the above steps, and the stretching ratio may be arbitrarily selected depending on the pitch of the intended connector. It may be stretched 1.5 to 5 times. In addition, in this stretching, the sheet or block obtained in each step is heated to a temperature corresponding to the melting point of the previously kneaded thermoplastic material, for example, about 2/3 of this melting point, and then heated in the stretching direction. It is done by pulling.

Next, examples of the method of the present invention will be given.

Example 1 a Insulating rubber material 100 parts of methyl vinyl polysiloxane raw rubber containing 0.5 mol% of vinyl groups and a specific surface area of 200 parts
100 parts by weight of a silicone rubber composition consisting of 50 parts of fumed silica of m ² /g and a density of 0.95
20 parts by weight of high-density polyethylene of g/ ^cm3 at 180℃
Mix uniformly with a heat roll at ~185℃ and after cooling 0.6
Added parts by weight of dicumyl peroxide.

b Conductive rubber substance Silicone rubber composition 100 consisting of 100 parts of methylvinylpolysiloxane raw rubber containing 0.3 mol% of vinyl groups and 50 parts of 30μ carbon powder
20 parts by weight of high-density polyethylene with a density of 0.95 g/cm ³ were uniformly mixed with a heated roll at 180°C to 185°C, and after cooling, 0.6 parts by weight of dicumyl peroxide was added.

Above a) When the roll part is removed from the insulating rubber material
After preforming a 100mm x 100mm x 0.05mm sheet and pressing it at 170℃ and 20Kg/ ^cm2 for 3 minutes,
b) Using a calendar roll on this sheet
500 pieces of this molded product were produced by topping the conductive rubber material to a thickness of 0.05 mm and pressing at 170° C. and 20 kg/cm ² for 3 minutes.

Next, apply KE as an adhesive to the surface of this molded product.
-1800RTV [manufactured by Shin-Etsu Chemical Co., Ltd., silicone rubber composition that cures at room temperature] was applied to a thickness of 5 μm using a bar coater, and then laminated at 100°C.
Heat under pressure for 2 hours at 20Kg/cm ² to form 100mm x 100mm x
A 50 mm vulcanized rubber block body was obtained.

Next, the thickness of this block body is adjusted in the stacking direction.
A striped sheet of 100mm x 50mm x 0.125mm obtained by cutting into 0.125mm is heated to 180℃, and 2.5mm is cut in the longitudinal direction.
The sheet was stretched twice and placed in water in this stretched state to be rapidly cooled to obtain a sheet of 250 mm x 50 mm x 0.05 mm.

Next, the insulating rubber composition of a) is topped on the surface of this stretched sheet with a calender roll to a thickness of 0.05 mm to make a 250 mm x 50 mm x 0.1 mm laminated sheet, and 300 of these sheets are laminated to form a 250 mm x 250 mm x 250 mm x 0.1 mm laminated sheet. After making it into a block shape of 50mm x 30mm, it was heated to 170℃ and 20Kg/cm ²
After heating under pressure for 1 hour and allowing it to cool, it was cut to a thickness of 0.5 mm in the stacking direction, resulting in a 50 mm x 30 mm x 0.5 piece with conductive parts arranged in a matrix at 100 μm intervals.
mm anisotropic conductive connector was obtained.

Example 2 The insulating rubber material and the conductive rubber material used in the previous example were each topped on a 0.1 mm thick polyester film using a calendar roll to a thickness of 0.05 mm, resulting in a film of 150 mm x 150 mm x 0.05 mm. 2
After joining two sheets with the rubber material, 170
℃ and 20 kg/cm ² for 3 minutes, and then the polyester film was peeled off from both sides.

Next, this laminated sheet is heated to 180°C, stretched to double its length, and then rapidly cooled in water to form a 300mm x 150mm sheet.
After forming a stretched sheet of mm x 0.05 mm, 910 sheets coated with KE-1800RTV (mentioned above) as an adhesive to a thickness of 5 μm were laminated on the surface, and this was heated at 100℃ for 20 minutes.
When heated under pressure for 3 hours at Kg/cm ² and allowed to cool to 50°C, a vulcanized block body of 300 mm x 150 mm x 50 mm was obtained.

Next, this vulcanized block body is stacked in the direction of stacking.
After cutting to a thickness of 0.1 mm, 100 parts of methylvinyl polysiloxane raw rubber containing 0.5 mol% of vinyl groups on the surface, 50 parts of fumed silica with a specific surface area of 200 m ² /g, and 0.8 parts of dicumyl peroxide were added.
The insulating rubber material 2 consisting of
Vulcanize this rubber layer by heating under pressure for 1.5 hours at ^cm2 ,
When left to cool to 50℃, a block of 300mm x 50mm x 50mm was obtained, which was further cut into pieces with a thickness of 0.1mm in the stacking direction. When the sheet was stretched with a change in width direction, the conductive parts were arranged in a matrix at 50 μm intervals, 100 mm × 25 mm ×
A 0.1 mm anisotropic conductive connector was obtained.

Example 3 From the insulating rubber material and conductive rubber material used in Example 2, a 300 mm
Make a 150mm x 0.2mm laminate, heat it to 180℃, stretch it twice, and quickly cool it in water to make a 150mm x 300mm.
After forming a stretched sheet of mm x 0.1 mm, this was cut in half to obtain a sheet of 150 mm x 300 mm x 0.1 mm.

Next, apply KE as an adhesive to this stretched sheet.
- After coating 1800RTV (mentioned above) with a bar coater to a thickness of 5μm, 500 of these sheets were laminated to form a block body, which was then heated under pressure at 100℃ and 20Kg/ ^cm2 for 1.5 hours to form a 150mm× It was a vulcanized rubber block body measuring 300 mm x 50 mm.

Next, this vulcanized rubber block was cut in the stacking direction to a thickness of 0.1 mm, 150 mm x 50 mm x 0.1 mm.
A striped sheet of mm is heated to 180℃ and 2
After stretching the sheet to a size of 300 mm x 50 mm x 0.05 mm, the insulating rubber material 2 used in Example 2 was topped with a calender roll to a thickness of 0.05 mm. The sheets were laminated to form a block of 300 mm x 500 mm x 50 mm.

Next, this block body was heated at 170℃ and 20Kg/ ^cm2 .
When heated under pressure for hours and allowed to cool to 50°C, a vulcanized block body was obtained, and the thickness was increased in the direction of lamination.
When sliced at 0.1 mm, the conductive parts were arranged in a matrix at 100 μm intervals, 50 mm x 50 mm.
A 0.1 mm anisotropic conductive connector was obtained.

Example 4 The insulating rubber material and conductive rubber material used in Example 1 were each rolled to a size of 100 mm x 100 mm.
Preformed into a 0.1 mm sheet and heated at 170℃ for 20
After pressing for 3 minutes at Kg/cm ² to produce 2000 insulating rubber sheets and conductive rubber sheets, each sheet was heated and stretched at 180°C to form an insulating sheet of 200 mm x 100 mm x 0.05 mm. A conductive stretched sheet and a conductive stretched sheet were obtained. Next, after coating these stretched sheets with adhesive to a thickness of 5 μm, 250 of these insulating stretched sheets and 250 conductive stretched sheets were alternately laminated to form a block body. cm ² for 1.5 hours and heating to form a vulcanized rubber block of 200 mm x 100 mm x 50 mm.

Next, this vulcanized rubber block was cut in the stacking direction to a thickness of 0.1 mm to obtain 100 mm x 50 mm x 0.1 mm.
Heat the sliced sheet to 180℃ and cut it in the longitudinal direction 2
After stretching the sheet to a size of 200 mm x 50 mm x 0.05 mm, the insulating rubber material 2 used in Example 2 was topped on this sheet to a thickness of 0.05 mm using a calender roll. 250 sheets were stacked to form a block of 200 mm x 50 mm x 25 mm.

Next, this block body was pressurized at 170°C and 20 kg/cm ² for 2 hours, heated, and then cooled. When the obtained vulcanized block body was sliced to a thickness of 0.3 mm in the stacking direction, the conductive parts were found to be in a matrix shape. Anisotropically conductive connectors of 50 mm x 25 mm x 0.3 mm arranged at 100 μm intervals were obtained.

[Brief explanation of the drawing]

1 to 6 are perspective views showing the process of the method of the present invention. DESCRIPTION OF SYMBOLS 1... Insulating rubber sheet, 2... Conductive rubber sheet, 3, 4... Striped contact sheet, 5... Insulating rubber sheet, 6... Insulating part, 7... Conductive part.

Claims (1)

[Scope of Claims] 1. A step of kneading a thermoplastic material into an unvulcanized conductive rubber material and an unvulcanized insulating rubber material, respectively, and then forming the mixture into a sheet; a process of alternately laminating the sheets to form a laminated block body A; a process of cutting this block body A in the direction of lamination to form striped sheets; and a process of alternately laminating the striped sheets and insulating rubber material sheets. A step of forming a laminated block body B by placing the block body B in parallel to the laminating direction,
and cutting the striped sheet in a direction intersecting the striped pattern, and after completing at least one of the above steps, the sheet or block obtained in the step is stretched to reduce the pitch interval. A method for manufacturing a low pitch anisotropic conductive connector.