JP2003123868A - Conductive rubber sheet and manufacturing method of the same, and pressure contact connector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a conductive rubber sheet prevented from warping after manufactured, capable of reducing the cost by improving workability at mounting, which can be stably connected to an objedt to be connected, and to provide a manufacturing method of the same and a pressure contact connector. SOLUTION: An insulation rubber sheet 6 is formed into a first and a second insulation sheets 1, 2 which are mutually laminated, and a conductive rubber sheet 4 is formed by arranging a plurality of fine conductive wires 3 in the longitudinal direction of the surface of the second insulation rubber sheet 2 at regular intervals. The conductive rubber sheet 4 of which, the cross section is formed into almost U-shape, is made to cover a part of the periphery of almost a block-shaped elastic insulation elastomer 5, and circuit boards are electrically connected with each other by the plurality of fine conductive wires 3 depending on pressure contact. Supporting function and reinforcing function are set to work by interposing the first insulation sheet 1 between the insulation elastomer 5 and the second insulation sheet 2.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to COG, COF,
The present invention relates to a conductive rubber sheet used for connection between a liquid crystal display module made of TAB and a circuit board, or between circuit boards, a method for manufacturing the conductive rubber sheet, and a pressure contact type connector.

[0002]

2. Description of the Related Art Conventionally, electrical connection between circuit boards has been
Although metal connectors have been used, there are various types of metal connectors. For example, the type shown in FIG. 4 is an elastic insulating elastomer 5 having a substantially semi-elliptical cross section interposed between circuit boards, and a curved peripheral surface of this insulating elastomer 5 is bent into a substantially U-shaped cross section and vulcanized. The insulating rubber sheet 6 to be adhered is composed of a plurality of conductive thin wires 3 arranged in parallel on the surface of the insulating rubber sheet 6 to electrically connect circuit boards. In addition to this, although not shown, a plate-shaped elastic insulating elastomer 5, an insulating rubber sheet 6 which is vulcanized and adhered to the surface of the insulating elastomer 5 by vulcanization, and the insulating rubber sheet 6 Of a plurality of conductive thin wires 3 which are arranged in parallel on the surface of and electrically connect between the circuit boards.

[0003]

Since the conventional metal connector is formed by simply vulcanizing and adhering the single layer insulating rubber sheet 6 to the insulating elastomer 5 as described above, these insulating elastomers 5 are used. And insulating rubber sheet 6
Due to the difference in easiness of elongation, there is a problem that it warps in the length direction after molding (see FIG. 5), which deteriorates workability during assembly. In particular, a metal connector having a length of 20 mm or more warps so much that it cannot be ignored, so that it cannot be automatically assembled, which delays the work, resulting in a significant cost increase. Since connection with a circuit board or the like is likely to be unstable in such a metal connector, there is often no continuity even when connected, which is a quality problem.

The present invention has been made in view of the above, and it is possible to prevent warpage after manufacturing, improve workability at the time of assembling and reduce cost, and stably connect to an electrical joint. An object of the present invention is to provide a conductive rubber sheet, a method for manufacturing a conductive rubber sheet, and a pressure contact type connector that can be manufactured.

[0005]

In order to achieve the above-mentioned object, the insulating rubber sheet is provided with a plurality of conductive fine wires, and the insulating rubber sheet comprises: It is characterized in that it is divided into first and second insulating rubber sheets which overlap each other, and the plurality of conductive thin wires are arranged side by side at a predetermined pitch on the surface of the second insulating rubber sheet. Further, in the invention of claim 2,
In order to achieve the above object, the surface of the vulcanized and cured first insulating rubber sheet is overlaid with an unvulcanized second insulating rubber sheet, and a plurality of conductive thin wires are arranged at a predetermined pitch on the surface. And vulcanizing and adhering the first and second insulating rubber sheets, and vulcanizing and adhering a plurality of conductive thin wires to the surface of the second insulating rubber sheet.

In order to achieve the above object, the invention according to claim 3 electrically connects the first and second electric joints provided in the vertical direction or the right angle direction, An insulating elastomer interposed between the first and second electric joints is provided, and a part of the peripheral surface of the insulating elastomer is coated with the conductive rubber sheet according to claim 1 in a substantially U-shaped cross section. The first and second electric joints are electrically connected by a plurality of conductive thin wires. The electrically conductive rubber sheet according to claim 1 is used to electrically connect the first and second horizontally provided electrical joints, and the electrically conductive rubber sheet according to claim 1 is provided on the surface of the substantially plate-shaped insulating elastomer. It is characterized in that the first and second electric joints are electrically connected to each other by a plurality of conductive thin wires, which are superposed and adhered.

Here, the thickness of the vulcanized and cured first insulating rubber sheet in the claims is 25 to 50 μm.
The thickness of the unvulcanized second insulating rubber sheet is 50
~ 150 μm is preferable. The overlapping thickness of these first and second insulating rubber sheets after vulcanization adhesion is preferably 75 to 200 μm. At least CO is present in the first and second electrical joints.
A liquid crystal display module including G, COF, and TAB, various circuit boards, semiconductor packages, and the like are included.
Moreover, examples of the shape of the insulating elastomer include a substantially rectangular cross section, a square, a semicircle, a semielliptical shape, and a semielliptical shape. The insulating elastomer may have a substantially rod shape or a substantially block shape, and the length of the insulating elastomer is not particularly limited. The substantially U-shaped cross section includes a U-shaped cross section, a C-shaped cross section, a U-shaped cross section, or a shape similar thereto.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a preferred embodiment of the present invention will be described with reference to the drawings. In the pressure contact type connector of the present embodiment, as shown in FIG. , The first and second insulating rubber sheets 1 and 2 to be laminated on each other, and a plurality of conductive thin wires 3 arranged in parallel at a predetermined pitch in the surface length direction of the second insulating rubber sheet 2. To produce a flexible conductive rubber sheet 4, and the conductive rubber sheet 4 is provided on the upper surface, front surface, and lower surface of a substantially block-shaped elastic insulating elastomer 5 interposed between upper and lower circuit boards (not shown). In other words, a part of the peripheral surface is bent and covered with a substantially U-shaped cross section, and the plurality of conductive thin wires 3 electrically connect between the circuit boards based on the pressure contact.

The first insulating rubber sheet 1 is made of chloroprene rubber, silicone rubber, isoprene rubber, butyl rubber, or fluorine on a film such as a polyester film or a polyimide film such as polyethylene terephthalate, polybutylene terephthalate, or polyethylene nitrile. It is formed by applying and vulcanizing a rubber material selected from rubber, urethane rubber and the like by a general method such as a topping method.

The second insulating rubber sheet 2 is a chloroprene rubber, a silicone rubber, an isoprene rubber, a butyl rubber, a fluororubber or a urethane, which is obtained by adding a primer to the thickness of about 25 to 50 μm on the first insulating rubber sheet 1. It is formed by applying a rubber material selected from rubber or the like to a thickness of about 50 to 150 μm by a general method such as a topping method. This thickness variation is preferably ± 5μ
m or less is good. The thickness variation (Rmax) is 1
This is because when it exceeds 0 μm, the arrangement pitch of the conductive thin wires 3 is likely to be disturbed. The rubber material is arbitrarily selected from the above types, but silicone rubber, which is excellent in environmental resistance characteristics and mechanical characteristics, is most suitable. In order to obtain such first and second insulating rubber sheets 1 and 2, a rubber material kneaded with 2 to 3 calender rolls is used as a non-shrinkable (5% or less) base material such as PET. The method of dispensing on the sheet is good.

Regarding the thicknesses of the first and second insulating rubber sheets 1 and 2, if these laminated thicknesses are too thick (about 200 μm or more), the moldability of bending in a U-shape deteriorates and the shrinkage ratio -Working efficiency decreases. Further, (1) the thickness ratio is preferably smaller than the first insulating rubber sheet 1: the second insulating rubber sheet 2 = 1: 2. This increases as the proportion of the first insulating rubber sheet 1 increases.
This is because the product warps in the length direction and becomes a defective product. Also, (2) the second insulating rubber sheet 2 has a thickness of 50 μm.
It is preferably about m or more. Therefore, the thickness of the first insulating rubber sheet 1 is preferably about 25 μm or more.

Therefore, the thicknesses of the first and second insulating rubber sheets 1 and 2 must simultaneously satisfy the following four conditions. The first insulating rubber sheet 1 has a thickness of about 25 μm or more, the second insulating rubber sheet 2 has a thickness of about 50 μm or more, the first insulating rubber sheet 1: the second insulating rubber sheet. It is better to be smaller than 2 = 1: 2. The total thickness of the first and second insulating rubber sheets 1 and 2 is about 200 μm or less.

As each conductive thin wire 3, a thin metal wire made of gold, gold alloy, platinum, copper, aluminum, aluminum-silicon alloy, brass, nickel silver, phosphor bronze, beryllium copper, nickel, molybdenum, tungsten, stainless steel, etc.,
Alternatively, it is possible to use thin wires or the like plated with a material having excellent electrical conductivity and environmental resistance such as gold, gold alloy, and rhodium. Among these, metal-based or gold-plated thin metal wires having excellent conductivity, environment resistance, and low contact characteristics are preferably used.

If the diameter of the conductive thin wire 3 is too large, a fine wiring pitch cannot be obtained, and if the conductive thin wire 3 is formed in an arc shape, the bending elasticity of the conductive thin wire 3 is too strong to follow the mold. Difficult to form into a circular arc shape. On the other hand, if the diameter is too small, it is easy to break during wiring. Therefore, the thickness of the conductive thin wire 3 is 3 to 500 μ, which is easy to form and handle.
m, preferably 10 to 100 μm, more preferably 15
It is selected in the range of ˜50 μm. Further, the thickness is preferably such that 30 to 80%, preferably 40 to 60% of the conductive thin wire 3 is embedded on the unvulcanized insulating rubber sheet.

The insulating elastomer 5 is made of various elastomer materials such as butadiene-styrene and butadiene-styrene.
Acrylonitrile, butadiene-isobutylene and other butadiene copolymers, chloroprene polymers, vinyl chloride-
It is molded by selecting from vinyl acetate copolymer, polyurethane, silicone rubber and the like. Among these, silicone rubber is preferable as the elastomer material because it is excellent in heat resistance, cold resistance, weather resistance, electric insulation, and nontoxic.

Next, a method of manufacturing the pressure contact type connector will be described. First, a silicone rubber material is prepared, and the silicone rubber material is seated on a long base material sheet and heat-vulcanized to obtain the first insulation. A rubber sheet 1 is prepared. After making the first insulating rubber sheet 1 in this way,
Another silicone rubber material is prepared, and this silicone rubber material is sheeted on the first insulating rubber sheet 1 to laminate the second insulating rubber sheet 2.

Next, a plurality of conductive thin wires 3 are arranged side by side at a predetermined pitch so as to be parallel to each other in the longitudinal direction of the surface of the second insulating rubber sheet 2, and excess portions of the plurality of conductive thin wires 3 are removed. . After arranging the plurality of conductive thin wires 3, the intermediate body consisting of the first and second insulating rubber sheets 1 and 2 and the conductive thin wires 3 is heated in an oven to be primarily vulcanized, and the first insulating rubber sheet The second insulating rubber sheet 2 is peeled off from the base material sheet 1 and heated again in an oven for secondary vulcanization to bond the first and second insulating rubber sheets 1 and 2 by vulcanization. Multiple conductive thin wires 3 are vulcanized and bonded to the surface of the
(See FIG. 2 (a)). Then, the integrated intermediate body is cut so as to cross the plurality of conductive thin wires 3 to form a predetermined size (see FIG. 2B).

Next, a three-dimensional sponge silicone rubber material 7 to be the insulating elastomer 5 is prepared and formed into a predetermined size (see FIG. 2 (c)). After forming the sponge silicone rubber material 7 to a predetermined size in this way, the intermediate body is set in the prepared lower mold 10 in a U-shaped cross section so that the plurality of conductive thin wires 3 face downward.
The sponge silicone rubber material 7 is set on the first insulative rubber sheet 1, the upper mold 11 is clamped to the lower mold 10 for pressure heating (see FIG. 2 (d)), and the sponge silicone is used. The first insulating rubber sheet 1 made by foaming the rubber material 7
The insulative elastomer 5 is formed in close contact with and is taken out from the molding lower mold 10 that has been opened.

Then, post-curing is performed under a predetermined condition to produce a long tentative pressure contact type connector shown in FIG. 2 (e), and thereafter, the pressure contact type connector is cut into a predetermined length and rubbed into a substantially block shape. Thus, a complete pressure contact type connector can be manufactured. Once the pressure contact type connector is manufactured in this way,
If the pressure contact type connectors are sandwiched between the upper and lower circuit boards and the upper circuit board is pressed down, the circuit boards can be electrically and softly connected by the plurality of conductive thin wires 3.

According to the above construction, the insulating elastomer 5
Since the first insulating rubber sheet 1 is interposed between the second insulating rubber sheet 2 and the second insulating rubber sheet 2, the supporting function and the reinforcing function are exerted,
Due to the difference in easiness of elongation between the insulating elastomer 5 and the second insulating rubber sheet 2, the press contact type connector can be prevented or suppressed from warping in the length direction after molding. Therefore, the workability at the time of assembling can be significantly improved. In particular, since the press-connecting type connector does not warp even if it has a length of 20 mm or more, automatic assembling becomes possible, and a large cost reduction can be achieved by facilitating, speeding up, and facilitating the work. Furthermore, by preventing the warpage, it is possible to connect to the circuit board etc. in a stable state.
The connection makes it possible to obtain reliable conduction.

Next, FIG. 3 shows an embodiment of the invention described in claim 4. In this case, first, flexible insulating rubber sheets 6 are laminated by vulcanization adhesion, The second insulating rubber sheets 1 and 2, and a flexible conductive rubber in which a plurality of conductive thin wires 3 are arranged in parallel at equal intervals in the surface length direction of the second insulating rubber sheet 2. While the sheet 4 is manufactured, the conductive rubber sheet 4 is laminated on the plate-shaped elastic insulating elastomer 5 and vulcanized and bonded, and a plurality of conductive thin wires 3 electrically connect between a pair of horizontal circuit boards. I try to connect to each other. The other parts are the same as those in the above-described embodiment, and thus the description thereof is omitted. Also in the present embodiment, the same effect as the above embodiment can be expected,
Moreover, it is clear that the diversification of the pressure contact type connector can be greatly expected.

Although nothing is formed on the back surface of the insulating elastomer 5 in the above embodiment, a reinforcing plate or a supporting plate made of elastomer may be bonded to the back surface of the insulating elastomer 5. Further, the pair of circuit boards in the embodiment of the invention described in claim 3, in other words, the first and second electrical joints may be provided in the vertical direction or the right angle direction.

[0023]

EXAMPLES Examples of the pressure contact type connector according to the present invention will be described below together with comparative examples. Example First, 100 parts by weight of silicone rubber compound KE-981U [trade name of Shin-Etsu Chemical Co., Ltd.] and 0.3 parts by weight of vulcanizing agents C-19A and B [trade name of Shin-Etsu Chemical Co., Ltd.], respectively. 2.5 parts by weight were added and blended to prepare a silicone rubber material, and the silicone rubber material was sheeted by a calender roll on a non-stretchable long base sheet made of a PET sheet to a thickness of 50 μm and heated. It was vulcanized to prepare a first insulating rubber sheet.

Next, the silicone rubber compound KE
-153U [trade name of Shin-Etsu Chemical Co., Ltd.] to 100 parts by weight of vulcanizing agents C-19A and B [trade name of Shin-Etsu Chemical Co., Ltd.], 0.5 parts by weight and 0.25 parts by weight, respectively.
Silane coupling agent KBM403 [trade name of Shin-Etsu Chemical Co., Ltd.] 1.0 part by weight was added and blended to prepare a silicone rubber material, and this silicone rubber material was calendered to a thickness on the first insulating rubber sheet. 100
A second insulating rubber sheet was laminated by sheeting to a thickness of μm.

Then, conductive thin wires having a diameter of 40 μm, which are made of brass wires plated with gold on the surface of the second insulating rubber sheet, are arranged side by side at a predetermined pitch, and excess portions of the plurality of conductive thin wires are removed. I prepared it. When arranging the plurality of conductive thin wires, the conductive thin wires are 30 m at a pitch of 100 μm.
After the m arrangement, the work was repeated by displacing by 0.4 mm, and then arranging the conductive thin wires at a pitch of 100 μm for 30 mm, and a plurality of conductive thin wires were arranged on the entire surface of the second insulating rubber sheet.

Next, the first and second insulating rubber sheets,
Conductive wire intermediate is placed in an oven at 120 ° C for 30
Heat for 1 minute to perform primary vulcanization, peel the base material sheet from the first insulating rubber sheet, and heat for 4 hours in an oven at 195 ° C. to perform secondary vulcanization. The sheet was vulcanized and bonded, and a plurality of conductive thin wires were vulcanized and bonded to the surface of the second insulating rubber sheet. Then, the integrated intermediate body was cut so as to cross a plurality of conductive thin wires to form a size having a width of 8.0 mm and a length of 300 mm.

Next, the silicone rubber compound KE
-151U [Shin-Etsu Chemical Co., Ltd. product name] 100 parts by weight, vulcanizing agents C-1 and C-3 [Shin-Etsu Chemical Co., Ltd. product name] 0.5 parts by weight, 2.0 parts by weight, foaming Agents 2, 2
-Add 1.8 parts by weight of azobisisobutyronitrile to prepare a three-dimensional sponge silicone rubber material that serves as an insulating elastomer, sheet the sponge silicone rubber material with a calender roll to a predetermined thickness, and The size of

Next, the intermediate body is set in a U-shaped cross section in the molding lower die to direct the plurality of conductive thin wires downward, and the sponge silicone rubber material is set on the first insulating rubber sheet. The upper mold for molding is clamped to the lower mold for molding, and 175 ° C. under pressure of 10 kg / cm ^2.
After heating for a minute, the sponge silicone rubber material was foamed to form an insulating elastomer that adheres to the first insulating rubber sheet, and was taken out from the lower mold for molding.

Then, post-curing was carried out under the condition of 200 ° C. for 1 hour to fabricate a pressure contact type connector of ± 300 mm, and the bending in the lengthwise direction was 0.3.
It was mm. This pressure-contact type connector was cut at the above-mentioned location where the conductive thin wires were not arranged and deviated by 0.4 mm to form a substantially block shape, thereby producing a pressure-contact type connector. There was almost no bending of the pressure contact type connector with respect to the surface in the length direction.

The press-connecting connector produced had almost no warp in the length direction, and therefore the workability during assembly could be significantly improved. In addition, the automatic embedding device enables automatic embedding, which facilitates and speeds up work.
We were able to reduce costs through simplification. Also,
The liquid crystal display, the circuit board, and the circuit boards can be stably connected to each other, and the connection enables reliable circuit continuity.

Comparative Example In the case of the conventional metal connector shown in FIG. 4, when it is long, warpage occurs in the length direction, and the workability at the time of assembly is really bad. Specifically, in the case of a metal connector having a length of 30 mm and a thickness of 2 mm, the warp with respect to the surface in the length direction is 3 m.
It reached m. Further, it is extremely difficult to connect the liquid crystal display to the circuit board and the circuit boards in a stable state, and it is almost impossible to obtain continuity of the circuit even if they are connected.

[0032]

As described above, according to the present invention, it is possible to prevent the warp after manufacturing, suppress the warp, improve the workability at the time of assembling, and reduce the cost. Also,
Through this, a stable connection with the electrical joint can be achieved.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a conductive rubber sheet and a pressure contact type connector according to claims 1 and 3 of the invention.

FIG. 2 is an explanatory view showing an embodiment of a method for producing a conductive rubber sheet according to the invention as set forth in claim 2, wherein FIG. 2 (a) shows the first and second insulating rubber sheets vulcanized and bonded, A perspective view showing a state in which conductive thin wires are vulcanized and adhered to the second insulating rubber sheet,
(b) is a perspective view showing a state in which an intermediate body composed of the first and second insulating rubber sheets and the conductive thin wire is cut into a predetermined size, and (c) is a sponge silicone rubber material. The perspective view showing the prepared state, (d) shows the intermediate body set in the molding lower die, the conductive thin wire is directed downward, the sponge silicone rubber material is set on the first insulating rubber sheet, and the molding is performed. Sectional drawing which shows the state which clamped the upper mold for shaping | molding to the lower mold, (e) figure is a perspective view which shows a long pressure contact type connector.

FIG. 3 is a perspective view showing an embodiment of a pressure contact type connector according to the invention of claim 4.

FIG. 4 is a perspective view showing a conventional metal connector.

FIG. 5 is a perspective view showing a problem of a conventional metal connector.

[Explanation of symbols]

1 First insulating rubber sheet 2 Second insulating rubber sheet 3 Conductive wire 4 Conductive rubber sheet 5 Insulating elastomer 6 Insulating rubber sheet 7 Sponge silicone rubber material

Claims (4)

[Claims] 1. A conductive rubber sheet having a plurality of conductive thin wires on an insulating rubber sheet, wherein the insulating rubber sheet is divided into first and second insulating rubber sheets that overlap each other, A conductive rubber sheet, wherein the plurality of conductive thin wires are arranged side by side at a predetermined pitch on the surface of the second insulating rubber sheet. 2. An unvulcanized second insulating rubber sheet is superposed on the surface of the vulcanized and cured first insulating rubber sheet, and a plurality of conductive thin wires are arranged at a predetermined pitch on the surface. Manufacturing a conductive rubber sheet characterized by vulcanizing and adhering the first and second insulating rubber sheets and vulcanizing and adhering a plurality of conductive thin wires to the surface of the second insulating rubber sheet. Method. 3. A press-connecting type connector for electrically connecting the first and second electric joints provided in the up-down direction or the right-angled direction, the interposing between the first and second electric joints. A plurality of the above-mentioned first and second electric joints are provided by coating a part of the peripheral surface of the insulating elastomer with the conductive rubber sheet according to claim 1 in a substantially U-shaped cross section. A pressure contact type connector characterized in that it is electrically connected with the conductive thin wire of. 4. A pressure contact type connector for electrically connecting first and second horizontally provided electrical joints, wherein the surface of the insulating elastomer is substantially plate-shaped. A pressure contact type connector, characterized in that conductive rubber sheets are stacked and adhered to each other so that the first and second electric joints are electrically connected by a plurality of conductive fine wires.