JPH0361313B2 - - Google Patents

Description

[Detailed Description of the Invention] [Objective of the Invention] (Field of Industrial Application) The present invention combines high conductivity and high springiness, which cannot be obtained with copper alloys such as phosphor bronze, which are currently widely used. At the same time, it is related to low-cost contact forming materials, and is essential for miniaturizing contacts such as connectors, switches, and relays, which are essential for making electronic equipment smaller, higher in performance, and lower in price.
This greatly contributes to lower prices.

(Prior art and its problems) Today, in order to save resources and be economical, the trend is to make products lighter, thinner, and smaller.In particular, in electronic products, the main focus is on achieving smaller size and higher performance. To this end, it is essential to realize miniaturization of components equipped with contacts, such as connectors and switches, which are used in large numbers in electronic equipment, and to enable high-density mounting in these electronic equipment. However, it is nearly impossible to achieve significant miniaturization with contacts made of copper alloys, which are currently widely used.

In other words, contacts used in connectors, switches, etc. must have both high conductivity and high springiness due to their characteristics, but in general, those with high conductivity are inferior in springiness, and those with high springiness are At present, there is no metal material that satisfies both requirements at the same time, such as poor conductivity.
Therefore, at present, copper alloys such as phosphor bronze that have the best balance of the above two requirements are used as contacts, but even copper alloys that are said to best meet the requirements are not conductive. The rate is much smaller than that of pure copper or even pure silver. As a result, in order to obtain a highly conductive contact with the required springiness, it is necessary to increase the cross section of the contact to improve its conductivity, which causes the contact to become large. You can't get away with it. Therefore, there are limits to the miniaturization of contacts. Moreover, copper alloys that can be used as spring materials are not only generally very expensive, but also require highly precise heat treatment with strictly controlled temperature, time, atmosphere, etc. during manufacturing, which is extremely troublesome. It is. Contacts made from this alloy are therefore expensive.

Therefore, in order to eliminate the above-mentioned drawbacks, for example, we tried to obtain a contact with high conductivity and excellent spring force by pressure-welding a metal with high conductivity to a metal with excellent spring properties, or by laminating them by electrolysis or vapor deposition. Attempts have been made to do so, but this method is unsatisfactory due to a number of drawbacks as described below. For example, this method directly joins different metals, so
As diffusion progresses over time, the composition and state of the metal change, making it difficult to maintain the initial properties and reducing performance. For example, when stainless steel is used as a spring material and is coated with highly conductive silver, copper, or gold, the oxide film on the surface that protects the stainless steel from rusting ensures that the coated metal is bonded securely. It has no choice but to be removed in order to Therefore, if defects or scratches such as pinholes or cracks occur in the coated metal, the excellent corrosion resistance of stainless steel will be lost. Particularly in this case, since the potentials of silver, copper, and gold are significantly different from the potential of stainless steel, there is a risk that corrosion of stainless steel will be electrochemically accelerated. Furthermore, for example, when two types of metals are closely bonded together, the strain force caused by the difference in the thermal expansion coefficients of the two metals when the temperature changes tends to cause problems such as the closely spaced metals separating from each other and being damaged.

Therefore, with conventional contacts, it is impossible to achieve smaller size and lower cost of connectors than the current situation, and it is impossible to improve performance, and it is almost impossible to realize smaller size and lower cost of electronic equipment through high-density mounting. . Therefore, there has been a strong demand for a contactor that can meet the above requirements.

The present invention is to provide a contact forming material that meets the above requirements.

[Structure of the invention]

(Means for Solving the Problems) The contact forming material of the present invention basically has a layer 1 made of a metal having a desired conductivity selected from existing metals, as shown in the cross-sectional view in FIG. , is characterized by a structure consisting of a metal layer 2 having a required spring force and an insulating intervening plastic layer for supporting and laminating the two types of metal layers 1 and 2, for example. It is made as follows.

A metal that satisfies the required electrical conductivity is selected as the material for forming the first metal layer 1 from existing metals such as copper, silver, gold, aluminum, and alloys thereof. In addition, the required spring force can be obtained from existing metals such as iron alloys such as stainless steel for springs, copper alloys such as beryllium copper for springs, metals containing spring strengthening agents such as Hoister, and amorphous metals. A metal having the following properties is selected as the material for forming the second metal layer 2. These can then be shaped into plates, strips, etc. depending on the required current capacity, spring force, shape of the contact to be made, manufacturing method, etc.
Heating a plate or sheet-like plastic material, such as epoxy, polyester, polyimide, polyamide, polyolefin, or nylon 3, formed into a foil or the like and coated with a thermoplastic or thermoadhesive adhesive and having the required thickness. It is made by pressure bonding or bonding with rubber-based or polymeric hardening adhesives. Further, the first and second metal layers 1 and 2 are formed on the plastic layer 3 by methods such as electroplating, chemical plating, vapor deposition, and sputtering.

(Functions and Effects) As described above, the present invention breaks away from the unreasonable conventional technical idea of trying to satisfy both conductivity and spring properties with a single substance, and the first metal layer 1 which shares the conductivity. By sharing the roles of the second metal layer 2 and the second metal layer 2, which share the roles of the second metal layer 2 and the spring property, the characteristics of each are effectively utilized, and there is no need to compromise between conductivity and spring property as in the conventional case. Therefore, for example, if the contact forming material 4 of the present invention made into a strip shape as shown in FIG. 2a is cut and molded as shown in FIG. 2b to make a contact 5, it is possible to make a contact 5 using a conventional copper alloy. It is possible to form smaller and cheaper products with the same current capacity and contact pressure compared to
This can be used to form the connector shown in FIG. For example, as shown in FIG.
Contacts of various shapes shown in Figures a to t can be formed.

Furthermore, in the present invention, the plastic layer 3, which can relatively freely obtain the required flexibility as required, is bonded to the first and second metal layers 1,
This is strongly supported by interposing it between the two. Therefore, the drawbacks of the conventional method due to the close contact between two metals can be eliminated. That is, in the present invention, the strain force caused by the bending applied during contact molding, the difference in the extension of the two metal layers due to the bending applied during use, and the difference in the coefficient of expansion of the two metals is absorbed by the plastic. Since the flexibility absorbs the material, there is no risk of damage due to metal adhesion coming apart. Also, due to the presence of the plastic layer 3,
Unlike a product in which two types of metals are directly brought into close contact with each other, composition changes due to metal diffusion over time are prevented, so performance does not deteriorate. Furthermore, by using an insulating material for the plastic layer 3, it is possible to electrically insulate the two metals and prevent the generation of local batteries due to the difference in potential between the two metals. Self-destruction due to the progress of chemical corrosion can be prevented, and the drawbacks of the conventional contacts due to the close contact between two metals mentioned above can be eliminated.

In addition to this, according to the present invention in which an insulating plastic layer 3 is interposed, the following excellent advantages in terms of connector construction can be obtained. For example, as shown in FIGS. 6a and 6b, a first metal layer 1 and a second metal layer 2 may be formed by photo-etching the front and back sides of a plate-shaped contact forming material 4 of the present invention, or a plastic layer may be formed. By making a contact forming material in which the first and second metal layers 1 and 2 are formed on the front and back sides of 3 by partial vapor deposition,
A contact group 5 having a desired insulation interval and size is arranged in the required number of poles. This is then folded in half at the center as shown in FIG. 6c and fixed to the insulating material 6. On the other hand, by bending the contact group 7 formed in the same manner into an H shape as shown in FIG. 7 and fixing it to the insulating material 8,
As shown in the figure, contact group 5 is a male connector and contact group 7 is a male connector.
A multi-pole connector can be manufactured using the female connector as the female connector.

Therefore, it is possible to arrange a large number of inexpensive and minute contacts with high density and precision without deformation, which is not possible with conventional contacts made by pressing expensive metal materials such as beryllium copper. Since the connector can be manufactured at low cost, by fixing it to an insulating block, a connector can be easily manufactured with a small number of parts. Therefore, unlike conventional methods in which a large number of press-formed contacts are inserted and fixed into fixing holes provided in an insulating block, the deformation of the contacts and the manufacturing accuracy of the spacing between the fixing holes are not considered at all. Since there is no need to do this, it is possible to manufacture a compact multi-pole connector at a low cost. According to prototype experiments, the first metal layer 1 was electrolytic copper foil with a thickness of 35 μm that had been heat-treated as a highly conductive metal, and the second metal layer 2, which provides spring properties, was made of stainless steel for springs rolled to a thickness of 100 μm. Very good results were obtained when the contacts of the connector were formed from a material using a 30 μm thick polyimide film as the insulating plastic layer 3 supporting the steel and metal layers 1 and 2.

Although the present invention has been described above, the contact forming material of the present invention may be of any material, shape, plate thickness, and number of layers as long as it is composed of a conductive material, a spring material, and an insulating plastic material. Therefore, a multilayer structure,
For example, as shown in FIG. 9a, there is a structure consisting of a first metal layer 1 with high conductivity, two metal layers 2a, 2b with high springiness, and two insulating plastic layers 3a, 3b interposed between these. can do. Further, as shown in FIG. 9b, the metal layer 1 imparting conductivity is formed of two metal layers 1a and 1b, and the metal layer 2 imparting spring properties is formed by interposing insulating plastic layers 3a and 3b between them. Various modifications can be made to the provided structure, such as providing even higher conductivity.

Furthermore, without creating a separate insulating plastic layer, for example, copper foil and stainless steel foil may be bonded together using a heat-sealable insulating plastic adhesive, or insulating plastic may be applied to one side of stainless steel foil, and the plastic Various manufacturing methods can be used, such as providing a metal such as silver or copper on the surface by vapor deposition or ion plating. In addition, in order to improve environmental resistance, abrasion resistance, electrical connection stability, weldability, solderability, etc., the first or second metal layer, and also necessary parts on the first and second metal layers. Metal plating can be applied to achieve the desired purpose, chemical treatment such as oxidation, and coating layers of oil, various paints, and various coating agents can be applied to the necessary parts.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing the basic configuration of the present invention, Fig. 2
3 and 4 are configuration examples of connector contacts and connectors made of the contact forming material of the present invention,
FIG. 5 is a diagram showing an example of the configuration of another contact, FIGS. 6, 7, and 8 are diagrams showing an example of the configuration of a multipolar connector using the contact forming material of the present invention, and FIG. 9 is a diagram of a modification of the present invention. It is. 1, 1a, 1b...first metal layer for obtaining conductivity, 2, 2a, 2b...second metal layer for obtaining springiness, 3, 3a, 3b...first, second metal layer an insulating plastic layer supporting 4... contact forming material, 5... contact group, 6... insulating material, 7...
Contact group, 8...Insulating material.

Claims (1)

[Claims] 1. A conductivity imparting metal layer and a spring property imparting metal layer,
A contact material for electrical connectors, characterized in that it is laminated with an insulating plastic layer interposed therebetween. 2. The contact material for an electrical connector according to claim 1, characterized in that the metal layer is made up of two or more layers. 3. A contact material for an electrical connector according to claim 1, characterized in that a layer having required properties such as environmental resistance is provided on the metal layer.