JP2006286574A - Electric contact - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric contact which has lubricity and a small friction coefficient, in which solder hardly adheres and transfer, in which stable contact resistance can be obtained, and which has a structure wherein a mating object slides on the electric contact. <P>SOLUTION: In this electric contact 10 in contact with an object which is the solder wherein at least its surface contains tin, a lubricous plated layer 28 comprising a plated layer of a metal matrix containing fine particles of PTFE (polytetrafluoroethylene) and a noble-metal plated layer 32 comprising an Au plated layer, having the thickness smaller than the diameter of the fine particles and formed on the lubricous plated layer 28 are applied on a surface of the electric contact 10, and a nearly U-shaped slit 20 is provided in the periphery of the electric contact 10. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electrical contact that comes into contact with an object that is a solder containing tin at least on its surface, and particularly relates to an electrical contact having a structure in which the electrical contact slides at the time of contact and does not easily adhere to and transfer solder. is there.

At least for electrical contacts that come into contact with an object that is a solder containing tin on the surface, there is no reduction in contact due to friction and wear due to sliding like contact with other hard contacts. When the solder containing tin adheres to or transfers to the electrical contact, the solder containing tin transfers to the electrical contact side, and the surface of the solder containing tin that has adhered or transferred has oxidized on the surface. Tin oxide is formed and becomes non-conductive. Repeated contact will cause new tin-containing solder to adhere to and transfer on this, resulting in the formation of an annual ring-shaped oxide film layer, leading to more unstable contact resistance. .
The term “adhesion” as used herein refers to a state in which the counterpart solder (PbSn) or solder oxide (SnO 2) is attached to the electrical contact. State.
Patent Document 1 (Japanese Patent Laid-Open No. 2000-67972) discloses a structure in which the counterpart slides on the electrical contact when the counterpart contacts the electrical contact. No.) discloses a surface treatment with good lubricity, and Patent Document 3 (Japanese Patent Laid-Open No. 2001-123292) discloses a surface treatment with low contact resistance and good lubricity and wear resistance. Yes.
The term “sliding” as used herein refers to movement (displacement) of the counterpart on the electrical contact when the counterpart contacts the electrical contact and presses the counterpart against the electrical contact (that is, the first contact position and the press). Later contact position is different).
SUMMARY OF THE INVENTION According to the summary of Japanese Patent Laid-Open No. 2000-67972, an object of the present invention is to provide an electrical connector in which a plurality of electrical contacts and a plurality of electrical contacts are electrically connected at a time. The plate portion and the second connector plate portion are detachably abutted to electrically connect the plurality of electrical contacts on one side of the first connector plate portion and the plurality of electrical contacts on one side of the second connector plate portion. In the electrical connector designed to be connected to the electrical connector, the electrical contact is provided on the substrate of the second connector plate portion, and a slit-shaped cut portion is provided on the substrate around the electrical contact, so that the electrical contact portion This is an electrical connector with elasticity, so that the entire connector can be made compact with a simple structure, and contact failure due to irregular height on the electrical contact side is prevented. Come, which can be easily ensured desired impedance characteristics is disclosed. Incidentally, in claim 1, the first connector plate portion and the second connector plate portion are detachably abutted to each other, and a plurality of electrical contacts on one side of the first connector plate portion and the second connector are connected. In the electrical connector configured to electrically connect a plurality of electrical contacts on one side of the plate portion, the electrical contact is provided on the substrate of the second connector plate portion, and around the electrical contact An electrical connector characterized in that a slit-shaped cut portion is provided on a substrate to give elasticity to the electrical contact portion. The electrical connector according to claim 1, wherein an elastic body layer is provided on the side of the substrate opposite to the electrical contact. 3. The electrical connector according to claim 1, wherein the electrical contact is provided on a substrate by a printed wiring pattern forming method. According to a fourth aspect of the present invention, there is disclosed an electrical connector according to the first, second, or third aspect, wherein a metal conductor portion that is electrically connected to the electrical contact is provided on a substrate opposite to the electrical contact. Yes. According to the summary of JP-A-6-308575, there is no need to use a lubricant, it has good lubricity over a long period of time, can perform a good sliding operation with a small torque, and noise during sliding. For the purpose of obtaining a sliding member for a camera that can reduce as much as possible, a composite in which low friction coefficient particles are eutectoidally dispersed in a metal matrix at a portion that slides in contact with another member of the sliding member A structure having a structure coated with a plating film is disclosed, and as an effect, it is disclosed that the initial driving torque can be reduced, the motor of the driving source can be downsized, and the battery consumption can be reduced. Incidentally, in the claims, in a sliding member constituting various mechanisms of a camera, a composite in which low friction coefficient particles are co-deposited and dispersed in a metal matrix at least a portion of the member that slides in contact with another member. A sliding member for a camera characterized by being coated with a plating film is disclosed. According to the summary of JP-A-2001-123292, it has a surface treatment structure with low contact resistance and good lubricity and wear resistance, and is suitable for any application of contact, sliding, fitting or decoration. A surface treatment structure in which a plating layer is formed on the surface of a base material for the purpose of providing a contact, sliding, fitting, decorative member and manufacturing method thereof that can be used. It comprises a lubricating plating layer comprising a metal matrix plating layer and a noble metal plating layer formed on the lubricating plating layer, wherein the diffusion preventing plating comprises a metal plating layer under the lubricating plating layer. A structure having a structure in which a bonding layer made of a strike plating layer of noble metal is formed between the lubricating plating layer and the noble metal plating layer is disclosed. Incidentally, in claim 1 of the claims, the surface treatment structure in which a plating layer is formed on the surface of the substrate, the lubricating plating layer comprising a plating layer of a metal matrix containing fine particles having lubricity, A surface treatment structure comprising a noble metal plating layer formed on the lubricating plating layer. 2. The surface treatment structure according to claim 1, wherein a diffusion prevention plating layer made of a metal plating layer is formed under the lubricating plating layer. 3. The surface treatment structure according to claim 1, wherein a bonding layer made of a noble metal strike plating layer is formed between the lubricating plating layer and the noble metal plating layer. According to a fourth aspect of the present invention, there is provided a base material, a lubricating plating layer formed on the base material and comprising a metal matrix plating layer containing fine particles having lubricity, and a noble metal plating layer formed on the lubricating plating layer. A contact, sliding, fitting and decorative member characterized by comprising: 5. The contact, sliding, and fitting according to claim 4, wherein a diffusion prevention plating layer made of a metal plating layer is formed between the base material and the lubricating plating layer. , Decorative elements. The contact point according to claim 4 or 5, wherein a joining layer made of a strike plating layer of noble metal is formed between the lubricating plating layer and the noble metal plating layer. Fitting, decorative member. The manufacturing method of a contact, sliding, fitting, and decorative member characterized by having the following steps (1) and (2). (1) A step of forming a lubricating plating layer comprising a plating layer of a metal matrix containing fine particles having lubricity on the surface of a substrate. (2) A step of forming a noble metal plating layer on the surface of the lubricating plating layer. According to an eighth aspect of the present invention, in the step (1), after forming a diffusion prevention plating layer made of a metal plating layer on the surface of the base material, lubrication made of the metal plating layer containing the fine particles having lubricity. The method of manufacturing a contact, sliding, fitting, or decorative member according to claim 7, wherein a plated layer is formed. According to a ninth aspect of the present invention, the method includes a step of forming a bonding layer made of a strike plating layer of a noble metal on the surface of the lubricating plating layer between the step (1) and the step (2). Item 7 or 8 discloses a method for producing a contact, sliding, fitting, or decorative member.

In the structure as disclosed in Patent Document 1, although the counterpart slides on the electrical contact, the friction coefficient is large, the solder is likely to adhere and transfer, and the contact resistance becomes unstable.
Patent Document 2 and Patent Document 3 are related to surface treatment, and are intended for contact between noble metals. None of the contacting materials is intended for tin-containing solder, and are intended to prevent solder adhesion and transfer. Not.
The surface treatment of Patent Document 2 certainly has lubricity and a small coefficient of friction, but nickel is oxidized, and the contact resistance is unstable and unsuitable for a contact. There is no suggestion of a structure in which the counterpart slides on the electrical contact. Furthermore, it cannot be estimated at all about prevention of solder adhesion and transfer.
Patent Document 3 is an improvement of Patent Document 2 and provides a surface treatment that makes it difficult for solder to adhere and transfer and provides stable contact resistance, but the counterpart slides on the electrical contact. There is no suggestion of such a structure. In the specification of Patent Document 3, there is a description of sliding. This means sliding between the sleeve of the contact pin and the plunger as shown in FIG. The contact plate that comes into contact does not slide as in the present application.

  The present invention has been made in view of such conventional problems, and has a lubricity, a small friction coefficient, hardly adheres to and disperses solder, and can obtain a stable contact resistance. It is intended to provide an electrical contact having a structure that slides on the surface.

  The object of the present invention is to form a metal matrix plating layer containing fine particles of PTFE (polytetrafluoroethylene) on the surface of the electrical contact 10 at least in contact with an object whose surface is a solder containing tin. A lubricating plating layer 28 and a noble metal plating layer 32 having a thickness of the Au plating layer formed on the lubricating plating layer 28 and not exceeding the diameter of the fine particles are applied, and a substantially U shape is formed around the electrical contact 10. This can be achieved by providing the slit 20.

An anti-diffusion plating layer 26 made of a metal plating layer is formed between the base material 12 of the electrical contact 10 and the lubricating plating layer 28.
Further, a bonding layer made of a noble metal strike plating layer 30 is formed between the lubricating plating layer 28 and the noble metal plating layer 32.
Protruding convex portions 13 are provided on the surface of the electrical contact 10.
The convex portion 13 is shaped like a mountain.
Furthermore, it is preferable that the noble metal plating layer 32 does not contain Co (cobalt) in order to easily expose PTFE (polytetrafluoroethylene) fine particles.

As is apparent from the above description, according to the electrical contact 10 of the present invention, the following excellent remarkable effects can be obtained.
(1) In the electrical contact 10 that contacts at least the surface of the object that is a solder containing tin, the surface of the electrical contact 10 is lubricated with a metal matrix plating layer containing PTFE (polytetrafluoroethylene) fine particles. A plating layer 28 and a noble metal plating layer 32, the thickness of which is an Au plating layer formed on the lubricating plating layer 28, the thickness of which does not exceed the diameter of the fine particles are applied. Since the slit 20 is provided, it is possible to wipe the deposit because the counterpart slides on the electrical contact 10, and the surface treatment layer 18 applied on the electrical contact 10 has lubricity, In addition, since the coefficient of friction is small and solder adhesion is difficult to prevent and transfer, it is possible to obtain stable contact resistance by further improving the wiping of the deposit as a synergistic effect. Kill.
(2) Since the diffusion prevention plating layer 26 made of a metal plating layer is formed between the base material 12 of the electrical contact 10 and the lubrication plating layer 28, diffusion of the noble metal plating layer 32 can be prevented.
(3) Since the bonding layer made of the noble metal strike plating layer 30 is formed between the lubricating plating layer 28 and the noble metal plating layer 32, the adhesion of the noble metal plating layer 32 can be improved.
(4) Since the projection-like convex portion 13 is provided on the surface of the electrical contact 10, the wiping function when the counterpart slides on the electrical contact 10 can be improved.
(5) Since the convex portion 13 has a mountain shape, it is possible to further improve the wiping function when the counterpart slides on the electrical contact 10.

The electrical contact of the present invention will be described with reference to FIGS. FIG. 1 shows an arrangement of electrical contacts, and FIG. 2 is a cross-sectional view of one electrical contact. FIG. 3 is an explanatory diagram of the surface treatment layer.
The electrical contact 10 of the present invention is in contact with an object that is solder containing tin at least on its surface.
As shown in FIG. 2, the electrical contact 10 includes at least a so-called copper-clad laminate 22 having a cover lay, polyimide (PI), and copper (Cu) as a contact portion 12 with a counterpart on the polyimide, and the contact. And a surface treatment layer 18 applied to the surface of the portion 12.

  A slit 20 having a substantially U shape is provided around the electrical contact 10 as shown in FIG. The slit 20 has a function of sliding the surface of the electrical contact 10 when the counterpart object is pressed when contacting the object which is a solder containing tin at least on the surface. By providing such an action, the object is to achieve a wiping effect of deposits on the surface of the electrical contact 10 when sliding. This is because if there is a deposit on the surface of the electrical contact 10, a stable contact resistance cannot be obtained. The size and shape of the slit 20 are appropriately designed in consideration of the pitch (interval) between the electrical contacts 10 and such action.

  As for the shape of the contact portion 12, it is desirable to provide a protruding convex portion 13 so as to protrude from the surface of the electrical contact 10. By providing the convex portion 13, the wiping function of the deposit can be improved. The shape of the convex portion 13 may be any shape as long as it can have such a function. In this embodiment, as shown in FIG. 2, the wiping function when sliding further on the electrical contact 10 is used. In order to improve the above, the convex portion 13 has a mountain shape. By making the mountain shape in the sliding direction, when the counterpart is pressed against the electrical contact 10, the convex portion 13 having a mountain shape is difficult to be brought into the counterpart, and a reliable connection (contact) is obtained. The wiping effect during sliding (which makes it easier to scrape off deposits) increases.

Hereinafter, the surface treatment applied to the base material 12 (contact portion) of the electrical contact 10 according to the present invention will be described with reference to FIG. As the surface treatment, only the lubricating plating layer 28 and the noble metal plating layer 32 may be applied. However, in consideration of preventing the diffusion of the noble metal plating layer 32 and improving the adhesion, Has two platings. In other words, the diffusion plating layer 26 made of a metal plating layer is formed on the surface of the base material 12 of the electrical contact 10, and the lubricating plating made of a metal matrix plating layer containing fine particles having lubricity thereon. A layer 28 is applied thereon, a bonding layer composed of a noble metal strike plating layer 30 is provided thereon, and a noble metal plating layer 32 is further provided thereon.
Each surface treatment will be described below.

  The base material 12 of the electrical contact 10 is made of copper (Cu) or an alloy thereof as described above.

First, the diffusion prevention plating layer 26 will be described.
The metal plating layer forming the diffusion prevention plating layer 26 prevents the material forming the base material 12 of the electrical contact from diffusing to the bonding layer side consisting of the noble metal plating layer 32 or the strike plating layer 30, and lubrication. In order to improve the adhesion of the plating layer 28 to the base material 12 of the electrical contact 10, a predetermined thickness is formed according to the material of the base material 12 and the type of noble metal used. In addition, a metal such as Zn or an alloy thereof may be formed of a conventionally known metal or an alloy thereof, among which Ni, Ni—P (phosphorus) alloy, Ni—B (boron) alloy, or the like can be suitably used. . Furthermore, it is preferable to use the same material as the metal material of the metal matrix forming the lubricating plating layer 28 described later.

  The diffusion preventing plating layer 26 can be plated by a known method such as electroplating or electroless plating depending on the material of the metal used, but Ni, Ni-P (phosphorus) alloy, Ni-B can be used. When a (boron) alloy is used, it is preferable to use electroless plating that facilitates uniform thickness.

  The predetermined thickness of the diffusion preventing plating layer 26 varies depending on the material of the base material 12 of the electrical contact 10 used and the type of the noble metal. For example, a Cu alloy is used for the base material 12 and Au is used for the noble metal plating layer 32. In this case, the thickness of the diffusion preventing plating layer 26 may be formed to 0.5 to 10 μm, preferably 1 to 5 μm, and more preferably 2 to 3 μm.

Next, the lubricating plating layer 28 will be described.
The lubricating fine particles contained in the lubricating plating layer 26 are preferably made of a material having a small friction coefficient and an insulator or a large electrical resistance, or a material having a suitably small friction coefficient and a large hardness. For example, PTFE (polytetra Fluoroethylene) or the like, or C (graphite) or BN (boron nitride), SiC (silicon carbide), or the like is preferable. Among them, it is particularly preferable to use PTFE.

The fine particles may have a particle size of 0.01 to 20 μm, preferably 0.1 to 10 μm, more preferably 0.2 to 1.0 μm.
The metal used for the lubricating plating layer 28 may be formed of a conventionally known metal such as a metal such as Ni, Cu, Zn, or an alloy thereof, or an alloy thereof, among which Ni, Ni—P (phosphorus) alloy, Ni— A B (boron) alloy or the like can be preferably used.

The thickness of the lubricating plating layer 28 is preferably 0.01 to 20 μm, more preferably 0.1 to 5 μm, and particularly preferably 0.2 to 1.0 μm.
In addition, the plating method of the lubricating plating layer 28 can be known, such as electroplating or electroless plating, depending on the material of the metal used, but when using Ni, Ni-P alloy, Ni-B alloy, etc. It is preferable to use electroless plating that can easily make the thickness uniform.

Next, the strike plating layer 30 will be described.
Before the noble metal plating layer 32 is formed on the lubrication plating layer 28, the bonding layer made of the noble metal strike plating layer 30 promotes prevention of substitution reaction and surface activation, and the lubrication plating layer 28 and the noble metal plating. It is a layer formed in order to improve the adhesive strength with the layer 32, and is formed by strike plating 30 with a noble metal.
Here, as the noble metal, in addition to the above-mentioned known noble metal or an alloy thereof, a metal or an alloy thereof whose electrical resistance, chemical stability, etc. are similar to those of the noble metal can be used, and in particular, Au can be preferably used. In this case, it is preferable to use high-purity Au.

  The thickness of the bonding layer of the noble metal by the strike plating 30 is designed such that the fine particles of the lubricating plating layer 28 protrude somewhat after the strike plating 30 and the noble metal plating 32 are applied. What is necessary is just to form in 01-0.5 micrometer, and it is preferable to form in 0.01-0.1 micrometer especially especially 0.01-0.03 micrometer.

  The bonding layer of the noble metal by the strike plating 30 can be formed by a known plating method such as electroplating, electroless displacement plating or catalyst plating. Here, when the strike plating 30 is performed by electroplating, it is preferable to set the current density during energization to be larger than that of normal electroplating, for example, about 5 A / dm2.

Finally, the noble metal plating layer 32 will be described.
The noble metal that forms the noble metal plating layer 32 is a noble metal that is a known noble metal or an alloy thereof, as well as an electric resistance, chemical stability, etc. An approximate metal or an alloy thereof can be used, and Au can be particularly preferably used. Here, the hardness of the Au plating layer can be improved by containing a slight amount of Co (cobalt) or the like. For example, the hardness of the Au plating layer formed of high-purity Au is usually about 40 to 50 in terms of Vickers hardness, but about 0.1 to 0.3% by mass of Co is included in the Au plating layer. Can improve the Vickers hardness to 150-200.

The thickness of the noble metal plating layer 32 is designed such that fine particles of the lubricating plating layer 28 protrude somewhat after the strike plating 30 and the noble metal plating 32 are applied. What is necessary is just to form in 0 micrometer, and it is preferable to form in 0.05-1.0 micrometer especially especially 0.1-1.0 micrometer.
The noble metal plating layer 32 can be formed by a known plating method such as electroplating, electroless displacement plating or catalyst plating.

According to the surface treatment layer 18 having such a configuration, as shown in FIG. 3, since the fine particles having lubricity are formed of an insulator or a member having a large electric resistance, the noble metal plating layer 32 is formed by electroplating. In the case of forming the bonding layer by the strike plating 30, noble metal does not precipitate on the fine particles or is difficult to deposit, and the fine particles are mixed in the bonding layer by the noble metal plating layer 32 to the strike plating 30, Furthermore, a surface treatment structure in which a part of the fine particles is exposed on the surface of the noble metal plating layer 32 is formed.
Further, even when the bonding layer formed by the noble metal plating layer 32 to the strike plating 30 is formed by electroless plating, in the replacement plating, the bonding layer formed by the noble metal plating layer 32 to the strike plating 30 and fine particles are used. Due to the potential difference, in catalytic plating, a catalytic reaction hardly occurs in the vicinity of the fine particles, so that noble metal does not precipitate on the fine particles or is difficult to deposit. In addition, a surface treatment structure in which a part of the fine particles are exposed on the surface of the noble metal plating layer 32 is formed.

  In the surface treatment structure according to the present invention, the diffusion prevention plating layer 26 is formed on the surface of the base material 12 of the electrical contact 10, and the diffusion prevention plating layer 26 contains fine particles having lubricity. The lubricating plating layer 28 is formed, and a surface treatment structure in which the noble metal plating layer 32 is formed on the lubricating plating layer 28 without forming the bonding layer by the strike plating 30 can be configured. The lubricating plating layer 28 containing fine particles having lubricity is formed on the surface of the base material 12 of the electrical contact 10 without forming the diffusion preventing plating layer 26. The surface treatment structure in which the noble metal plating layer 32 is formed can be configured, and the surface of the base material 12 of the electrical contact 10 contains fine particles having lubricity. A surface layer structure is formed in which a sticky layer 28 is formed, a bonding layer by the strike plating 30 is formed on the lubricating plating 28, and the noble metal plating layer 32 is formed on the bonding layer by the strike plating 30. You can also.

  As an application example of the present invention, the present invention relates to an electrical contact that contacts with an object that is a solder containing tin at least on its surface, and particularly has an wiping function.

It is the top view which showed the arrangement | sequence of an electrical contact. It is sectional drawing which carried out the cross section of one electrical contact. It is explanatory drawing of a surface treatment layer.

Explanation of symbols

10 Electrical contact 12 Base material (contact part)
13 Convex part 14 Coverlay 16 Polyimide 18 Surface treatment layer 20 Slit 22 Laminated substrate 24 Through hole 26 Diffusion prevention plating layer 28 Lubrication plating layer 30 Strike plating layer 32 Noble metal plating layer

Claims (5)

At least in electrical contact with an object whose surface is a solder containing tin,
On the surface of the electrical contact, the thickness of the lubricating plating layer made of a metal matrix plating layer containing PTFE (polytetrafluoroethylene) fine particles and the Au plating layer formed on the lubricating plating layer is the fine particles. A noble metal plating layer that does not exceed the diameter is provided, and a substantially U-shaped slit is provided around the electrical contact. 2. The electrical contact according to claim 1, wherein a diffusion prevention plating layer made of a metal plating layer is formed between the base material of the electrical contact and the lubricating plating layer. The electrical contact according to claim 1, wherein a bonding layer made of a strike plating layer of a noble metal is formed between the lubricating plating layer and the noble metal plating layer. 4. The electrical contact according to claim 1, 2 or 3, wherein a projecting convex portion is provided on a surface of the electrical contact. The electrical contact according to any one of claims 1 to 4, wherein the convex portion is shaped like a mountain.

Images