JPS6215777A - Film-like connector and manufacture thereof - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention <Industrial Application Field> The present invention relates to a film-like connector used for connecting printed wiring boards to each other or to connecting printed wiring boards to electrodes in electrical and electronic equipment, and the production thereof. Regarding the method, the object is to provide a flexible film-like connector having excellent electrical properties and reliability, and a method for manufacturing the same.

<Conventional configurations and their problems> Conventionally, the following types of flexible connectors have been used to connect printed wiring boards to each other or to connect printed wiring boards to electrodes in electrical and electronic equipment. Ta. That is, (A thin plate-shaped connector made by laminating a large number of thin plates of Al conductive rubber and thin plates of insulating rubber alternately and cutting them thinly in a direction intersecting the surface of the thin plates) of a conductor. A film-like connector made by thinly cutting a molded product in which a large number of thin wires are buried and arranged in parallel in a flexible polymeric insulating material. Conductor particles of metal powder are mixed with an insulating elastic material such as FCL silicone rubber. There were flexible film connectors made by molding this into a sheet.

However, all of these had the following drawbacks. In other words, +al and (bl connectors are expensive because their manufacturing process is complicated and requires precision, and the connection to the other electrode is physically crimped, so reliability is low. be lacking, (C1
The connector has uneven conductivity and low reliability due to irregular conductor particles, and the connection part with the other electrode is unreliable because it is physically crimped. There were other problems.

As a solution to such problems, fd) a predetermined vertical striped connector circuit pattern is screened on a flexible insulating substrate film using an insulating thermocompression suspension and a conductive suspension sequentially. A film-like connector (see Japanese Patent Publication No. Sho 58-12586) has been proposed, which is formed by a printing method and obtained by cutting the film to a desired size.

However, this connector also has the following various problems. This will be explained using drawings.

FIG. 10 and FIG. 1) are cross-sectional views of a film-like connector described in Japanese Patent Publication No. 58-12586. 1st
In Figure 0 and Figure 1), 1 is a flexible insulating substrate film, 14 is a thermocompression bonding layer formed by screen printing using an insulating thermocompression suspension, and 15 is a thermocompression bonding layer formed using a conductive suspension. This is a conductive vertically striped layer formed using the same method. However, in such connectors, the connection between the electrodes is made only by applying the insulating thermocompression suspension, so the adhesive strength is poor and the axial stability is poor. The connector shown in Figure 10 is formed using an insulating thermocompression suspension and a conductive suspension. There have been problems, such as the difficulty of forming fine conductive circuit patterns because it is necessary to perform printing while accurately registering the liquid.

<Object of the Invention> An object of the present invention is to provide a large film-like connector that has good electrical properties and excellent reliability, and in which a fine conductive circuit pattern is formed with high accuracy, and to The present invention provides a method for easily manufacturing a connector.

<Details of the structure of the invention> That is, the present invention provides a film-like connector that is flexible and has excellent dimensional stability, and is used when connecting printed wiring boards or between printed wiring boards and electrodes in electrical and electronic equipment. on an insulating plastic film with
An inorganic compound layer consisting of an inorganic compound layer having insulation properties and excellent corrosion resistance is formed, and a first metal bag made of a single metal or an alloy of two or more metals having conductivity is formed on the inorganic compound layer. layer, a second metal pattern layer made of a single metal or an alloy of two or more metals having conductivity and excellent corrosion resistance, and a pattern layer using a conductive organic material as a binder are sequentially laminated. This is a film-like connector characterized in that a conductive circuit pattern portion is formed, and a hot-melt adhesive layer having anisotropic conductivity is further formed on the surface of the conductive circuit pattern portion. Furthermore, the present invention provides a method for manufacturing a film-like connector used for connecting printed wiring boards to each other or to connecting printed wiring boards to electrodes in electrical and electronic equipment. A step of forming an inorganic compound layer made of an inorganic compound having insulation properties and excellent corrosion resistance on an insulating plastic film, A step of forming a first metal layer made of an alloy of the above metals (C1) on the first metal layer made of a single metal or an alloy of two or more metals having conductivity and excellent corrosion resistance. (d) forming a patterned layer of a predetermined shape using an organic material as a binder on the second metal layer using an ink having conductivity and an etching resist function; (e) etching the first metal layer and the second metal layer using the pattern layer as an etching resist to form first and second metal pattern layers that match the pattern layer using the organic material as a binder; By doing so, the first and second
a step of forming a conductive circuit pattern portion made of a laminate in which a pattern layer using an organic material as a binder is provided on a metal pattern layer;
A method for manufacturing a film-like connector, comprising the steps of: forming a hot-melt adhesive layer having anisotropic conductivity.

Hereinafter, the present invention will be explained in detail using the drawings.

FIG. 1 is a sectional view showing an embodiment of a film-like connector according to the present invention. 1 is an insulating plastic film, 2 is an insulating inorganic compound layer, 3a is a first metal pattern layer that is conductive, 3b is a second metal pattern layer that is conductive, and 4 is an organic compound layer that is conductive. A pattern layer using a material as a binder, 5 a hot-melt adhesive layer having anisotropic conductivity, and 6 a layer of the first and second metal pattern layers 3;
This is a conductive circuit pattern portion made of a laminate of a, 3b and the pattern layer 4.

FIG. 2 is a sectional view showing another embodiment of the film-like connector according to the present invention. 7 is an insulating layer, and the others are the same as in FIG.

Next, each of the constituent layers will be explained in more detail while explaining the method for manufacturing the film-like connector.

3 to 6 are cross-sectional views showing the manufacturing process of the film-like connector shown in FIG. 1.

First, an inorganic compound layer 2 is formed on an insulating plastic film 1 using a stable inorganic compound that has insulating properties and has excellent corrosion resistance in the atmosphere (see Fig. 3).
.

The insulating plastic film l according to the present invention is, for example, a single film such as a polyester film, a polyimide film, a polyetherimide, a polysulfone film, or a polyethersulfone film, or a composite film that has flexibility and dimensions. A plastic film having excellent stability and electrical insulation properties can be used. The film thickness is 1
A thickness in the range of 2 μm to 100 μm is suitable. This is because when the thickness is less than 12 μm, the dimensional stability decreases and it becomes difficult to handle, while when it is thicker than 100 μm, there are problems in use in terms of flexibility.

This insulating plastic film 1 has been subjected to corona discharge treatment, plasma treatment, chemical treatment, etc., or has been exposed to a gas flame, in order to increase the adhesion strength with the inorganic compound layer 2, which will be described later. It is preferable to use one coated with a primer layer. Furthermore, a material coated with a backside coating layer to prevent curling may be used.

In addition, examples of the stable inorganic compound layer 2 having insulation properties and excellent corrosion resistance in the atmosphere according to the present invention include silicon oxide, aluminum oxide, zirconium oxide,
Formed using magnesium oxide, helium oxide, nitrogen carbide, silicon nitride, etc. The inorganic compound layer 2 is made of a material that is stable against water and oxygen in the atmosphere,
It does not corrode easily and does not allow moisture or oxygen to pass through.
It has a function of preventing corrosion of the first metal pattern layer 3a, which will be described later.

The layer thickness of the inorganic compound layer 2 is 50 Å or more, preferably 2
It is recommended that the number of participants range from 00 to 10,000 people.

The method for forming the inorganic compound layer 2 includes a vacuum evaporation method,
Examples include sputtering method, ion blating method, CVD method, chemical plating method, etc.

Next, a first metal layer 13a having excellent conductivity is formed on the inorganic compound layer 2.

The first metal N15a is formed using, for example, a single metal such as copper or aluminum or an alloy of two or more metals. The first metal layer 13a is formed by selecting a metal with a low electrical resistance value, and has a function of ensuring good electrical characteristics.

The layer thickness of the first metal lit 13a is 100 to 10
,000 people.

The method for forming the first metal layer 13a includes a vacuum evaporation method, a sputtering method, an ion blasting method, and a CVD method.
method, chemical plating method, etc.

Next, the first metal Jli 13a is formed, and
A second metal layer 13b having excellent conductivity is formed.

As the second metal layer 13b, for example, a single metal such as nickel, tin, zinc, or indium, or an alloy of the above metals can be used. The second metal layer 13b is
The second metal layer 13b has a function of preventing corrosion of the first metal N15a, since a substance is selected that is stable against water and oxygen in the atmosphere, and does not easily corrode and does not allow moisture and oxygen to pass through. The thickness is preferably 100 Å or more, preferably 300 to 10,000.

As a method for forming the second metal layer 13b, in addition to the same method as that for the first metal layer 13a, an electroplating method can also be used.

Next, on the insulating plastic film 1 on which the second metal layer 13b is formed, a pattern N4 is formed in a predetermined manner using a substance that is conductive and has an etching resist function. Form into shape (4th
(see figure).

As the material having electrical conductivity and having an etching resist function according to the present invention, acid-resistant and alkali-resistant binders are appropriately selected and used depending on the etching process described below.
For example, printing ink such as conductive carbon paste is used.

The method for forming the conductive pattern layer 4 is as follows:
There are various printing methods such as screen printing, letterpress printing, planographic printing, and flexographic printing, and photolithography. In the film-like connector according to the present invention, when the conductive circuit pattern portion 6 described below is formed using printing means,
The pattern can be easily formed into any shape. Further, when formed using a photolithography method, it is possible to form a precise pattern in an arbitrary shape.

Next, using the pattern layer 4 as an etching resist,
The first and second metal layers 13a and 13b are etched (see FIG. 5). As an etching method, for example, the metal layers 13a, 13b, pattern layer 4, etc. are formed in an etching solution capable of etching the metal layers 13a, 13b, such as a ferric chloride solution or a cupric chloride solution. By dipping the insulating plastic film 1, the metal layer 1 other than the portion where the pattern N4 is formed is removed.
3a and 13b may be removed by corrosion and dissolution.

By doing so, the first and second metal pattern layers 3a and 3b having a shape that completely matches the pattern layer 4 using the organic material as a binder are formed, and the pattern layer 4 and the metal pattern layer 3a, A conductive circuit pattern portion 6 made of a laminate with 3b is formed.

It goes without saying that the etching process described above can be performed not only by a wet process but also by a dry process.

Next, a hot melt adhesive layer 5 having anisotropic conductivity is formed on the surface on which the conductive circuit pattern portion 6 is formed (
(See Figure 1). The hot-melt adhesive layer 5 may be formed on the entire surface on which the conductive circuit pattern portion 6 is formed, or may be formed only on at least the portion connected to the other electrode.

When the hot-melt adhesive layer 5 is formed only on the part connected to the other electrode, at least the part where the hot-melt adhesive layer 5 is not formed is insulated so that the conductive circuit pattern part 6 is not exposed. The hot-melt adhesive layer 5 may be covered with a layer (see FIG. 2), for example,
For example, carbon may be used as the conductive powder 10 in a single or mixed type general hot melt adhesive such as polyester, epoxy, vinyl acetate, vinyl, polyolefin, or polyamide.

It is possible to use materials in which gold, silver, copper, nickel, tin oxide, indium oxide, etc. are dispersed.

It is also possible to mix a crosslinking agent or a resin having a group that reacts with these resins with the adhesive and bond the adhesive under heat and pressure in a thermoplastic state before curing.

Therefore, by using a mixture of these crosslinking agents and resins, it is also possible to use resins that are ultimately crosslinked.

The proportion of the conductive powder dispersed in the adhesive is appropriately adjusted and determined to such an extent that the hot-melt adhesive layer 5 exhibits anisotropic conductivity. That is, during heat-press bonding, only the resin flows out and the conductive powder remains to provide continuity in the vertical direction, while the conductive powder is sparsely distributed in other directions so that it is insulated. For example, in the case of carbon blank, the amount is preferably in the range of 0.1 to 20 parts by weight, preferably 0.5 to 10 parts by weight, based on 100 parts by weight of the adhesive. This is because if the amount added is less than 0.1 parts by weight, the number of carbon black particles sandwiched between the conductive circuit pattern part 6 and the mating electrode described later will decrease, making it difficult to obtain the effect as a connector. Moreover, if the amount exceeds 10 parts by weight, the hot-melt adhesive layer 5 itself becomes conductive, and this also makes it impossible to obtain the effect as a connector.

The layer thickness of the hot-melt adhesive layer 5 is usually 1 to 100 μm.
is preferable, because if it is less than 1 μm, the adhesive force will be reduced, and if it exceeds 100 μm, there is a possibility of poor conductivity.

The hot-melt adhesive layer 5 can be formed by directly forming it on the surface on which the conductive circuit pattern part 6 is formed by a coating method, a printing method, etc., or by using a carrier film 1 prepared separately in advance. There is a method of forming the conductive circuit pattern portion 6 on the conductive circuit pattern portion 6 by a coating method, a printing method, etc. (
(See Figure 6).

Next, a method of using the above-mentioned film connector will be explained.

When using the film-like connector shown in FIG.
They are stacked facing each other in positions corresponding to the transparent electrode portions 9 formed above, and hot pressed (see FIGS. 7, 8, and 9).

By doing so, a hot melt adhesive layer 5 is provided between the conductive circuit pattern section 6 and the transparent electrode section 9.
The conductive powder 1O inside is sandwiched and electrical conduction is obtained, and at the same time, it is easily compressed by the melt adhesive action of the hot-melt adhesive, thereby connecting the conductive circuit pattern part 6 and the transparent electrode part 9. Therefore, the effect as a connector can be obtained.

The film connector shown in FIG. 2 can also be used in the same way as the one shown in FIG. 1 (not shown).

It goes without saying that the film-like connector according to the present invention can be applied not only to the connection with the transparent electrodes but also, for example, to the connection between electrodes of a printed wiring board.

Examples will be given and explained below.

<Example> After corona treatment was applied to a polyester film that had been heat-treated to a thickness of 38 μm, 200 μm of silicon oxide was applied using a vacuum evaporation method.
2,500 people made copper, and 400 people made nickel. On top of that, a vertical striped conductive circuit pattern of 0.3 mm in the line, 0.6 mm pitch, 10 μm dry printed film, and 50 mm square in size was printed using ink with the following composition by screen printing, and Hardening treatment was performed under the treatment conditions.

Printing ink binder: Polyurethane Solvent: Mixed solvent mainly composed of butyl sesolve acetate Conductive powder: Acetylene plastic and graphite Next, the printed pattern layer is used as an etching resist.
The metal part is etched by immersion in a ferric chloride solution for about 10 seconds to form a metal pattern layer that completely matches the printed pattern, and a conductive circuit pattern consisting of the printed pattern layer and the metal pattern layer is formed on the polyester film. The division was formed.

Thereafter, after washing with water and drying, the entire surface is laminated using a thermal adhesive film in which a heat-melting adhesive layer having the composition shown below is formed on a carrier film so as to cover the surface on which the conductive circuit pattern part is formed. Laminated on.

Hot-melt adhesive linear saturated polyester resin = 72 parts by weight tackifier
: 20 parts by weight additive =
2 parts by weight Carbon filler: 6 parts by weight Continuity results of the connector part and contact resistance part when the film-like connector thus prepared was pasted between the printed circuit board electrode and the transparent electrode on the glass substrate under the following crimping conditions. are shown in Table 1. Table 1 also shows the conduction results under the same conditions for a film connector in which the conductive circuit pattern portion was made of carbon paste alone.

Crimping condition temperature: 160℃ Time: 30sec Pressure crab 30kg/cm” Table 1 Electric shock resistance (5ON length, 0.3Fm width) Conventional connector
6. 0 ±0.5 kΩ Example 0.05±
0.02Ω <Effect> Since the present invention relates to a method for manufacturing a film connector having the above-described configuration, it is possible to extremely easily manufacture a film connector on which a predetermined conductive circuit pattern is formed. It is possible. - Furthermore, the film-like connector obtained by the present invention is
Since the metal pattern layer having a low resistance value is used as one of the constituent layers of the conductive circuit pattern portion, it has good electrical characteristics.

Moreover, the film-like connector obtained by the present invention is
Since the metal pattern layer with low resistance value is sandwiched between two highly stable layers, the electrical properties are stable over a long period of time, and the resistance remains even after 1,000 hours at 60°C and 95% RH. The increase in value is 10% or less, and the reliability is good.

Furthermore, since the conductive circuit pattern part is connected to the other electrode by the melting adhesive action of the hot-melt adhesive, perfect adhesion is achieved and there is no risk of poor conductivity due to long-term use. can be connected reliably to

Therefore, the film connector according to the present invention can be used to connect printed wiring boards such as electronic computers and their peripheral equipment, communication equipment, broadcasting equipment, control equipment, measuring equipment, telegraph and telephone equipment, various display equipment, etc., and from printed wiring boards to other equipment. It can be effectively used for connection with electrodes in electrical and electronic equipment.

[Brief explanation of the drawing]

1 and 2 are cross-sectional views showing an embodiment of a film-like connector according to the present invention. FIGS. 3 to 6 are cross-sectional views showing the steps of manufacturing a film-like connector according to the present invention. FIGS. 7 to 9 are cross-sectional views showing how the film-like connector according to the present invention is used. FIG. 10 and FIG. 1) are cross-sectional views showing a conventional connector. 1-・-・-ii edge plastic film 2 ・-
・----1--Inorganic compound layer 3 ・--・--Metal pattern layer 3a ----1--1st metal pattern layer 3b--
−−−−1−−−Second metal pattern layer 4 ・・−・−
... Pattern layer 5 having conductivity and using an organic material as a binder --------- Hot-melt adhesive layer 6 having anisotropic conductivity --- Conductive circuit pattern part 7-・
---・-----1. Colored edge layer 8--Glass substrate 9--Transparent electrode portion 10--Conductive powder 1)・−・−・−Carrier film 13−−−−−−・・−・Metal layer 13a−・−・−・−・−First metal layer 13b−・−・・−・・−Second metal layer 14 −・・−・−・・Thermocompression bonding layer

Claims (4)

[Claims] (1) In film connectors used to connect printed wiring boards to each other or to connect printed wiring boards to electrodes in electrical and electronic devices, the A stable inorganic compound layer having insulation properties and excellent corrosion resistance in the atmosphere is formed, and a first layer made of a single metal or an alloy of two or more metals with excellent conductivity is formed on the inorganic compound layer. A metal pattern layer, a second metal pattern layer made of a stable single metal or an alloy of two or more metals that is electrically conductive and has excellent corrosion resistance in the atmosphere, and a binder that is an organic material that is electrically conductive. A film characterized in that a conductive circuit pattern portion is formed by sequentially laminating pattern layers, and a hot melt adhesive layer having anisotropic conductivity is further formed on the surface of the conductive circuit pattern portion. shape connector. (2) On the surface on which the conductive circuit pattern part is formed, a heat-melt adhesive layer having anisotropic conductivity is formed in the connect part, and at least the part other than the connect part where the heat-melt adhesive layer is not formed. 2. The film-like connector according to claim 1, wherein a portion thereof is covered with an insulating layer. (3) In a method for manufacturing a film-like connector used to connect printed wiring boards to each other or to connect printed wiring boards to electrodes in electrical and electronic equipment, (a) insulation with excellent dimensional stability and flexibility; (b) forming a stable inorganic compound layer with insulation properties and excellent corrosion resistance in the atmosphere on a plastic film; a step of forming a first metal layer made of an alloy of two or more metals; (c) forming a stable single metal or two having conductivity and excellent corrosion resistance in the atmosphere on the first metal layer; forming a second metal layer made of an alloy of one or more metals; (d) using a substance having conductivity and an etching resist function on the second metal layer, and using an organic material as a binder; (e) using the pattern layer containing the organic material as a binder as an etching resist, etching the first metal layer and the second metal layer to form a pattern layer in a predetermined shape; and a second metal pattern layer.
a step of forming a conductive circuit pattern portion made of a laminate in which a pattern layer using an organic material as a binder is provided on a metal pattern layer; (f) on the surface on which the conductive circuit pattern portion is formed;
A method for producing a film-like connector, comprising the steps of: forming a hot-melt adhesive layer having anisotropic conductivity. (4) Forming a heat-melt adhesive layer having anisotropic conductivity on the surface on which the conductive circuit pattern part is formed in the connect part, and at least forming the heat-melt adhesive layer on the connect part other than the connect part where the heat-melt adhesive layer is not formed. 4. The method of manufacturing a film-like connector according to claim 3, further comprising the step of forming an insulating layer on the portion.