JPS63314812A - Sliding contact device - Google Patents

Abstract

PURPOSE:To improve the reliability of contacting, and lengthen remarkably the working life of a sliding contact device, by using Ag-Mo of 10-50wt.% for slide contact material fixed on a spring terminal member. CONSTITUTION:A wiring pattern 4 is constituted by arranging an RuO2 thick film resistance pattern 2, and an Au thick film pattern 3 having a specified interval and length, on an Al2O3 substrate 1. For the contact wire material 6 of a moving contact 5 sliding on the Au pattern 3, Ag-Mo of 10-50wt.% is used. The hardness of this material is about Hv 80-140, and the material is soft and easy to slide. Therefore, in the case of contacting action, a conductor pattern of the Au system thick film on the ceramic substrate is prevented from abrading, cohering and exfoliating, so that the reliability of contacting is improved and the working life of the device is remarkably lengthened.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention applies to volume switches, potentiometers, and trimmers used for detection, control, setting, oscillators, etc. in measuring instruments, various machines, etc. (a type of variable resistor)
This paper relates to improvements to sliding contact devices used in, etc.

(Prior art and its problems) Sliding contact devices conventionally used in the above-mentioned volume switches, potentiometers, trimmers, etc. are made of carbon (C) or ruthenium oxide (Rung oxide) on a ceramic substrate.
), etc., to form a thick film resistance pattern, and a spring terminal material that can slide against the thick film resistance pattern of this wiring board, and an Ag contact material. The sliding contact device is constructed with a caulked or welded sliding contact, but this sliding contact device tends to generate noise, has a rather high contact resistance (and is unstable due to some variation, and is prone to wear). It was easy to contact, had a short lifespan, and was somewhat lacking in contact reliability.

For this reason, the part that slides with the sliding contact of the carbon or ruthenium oxide thick film resistor pattern on the ceramic substrate is
Either replace it with g-Pd-based conductor paste and bake it, or add Ag to the part that slides with the sliding contact of the thick film resistor pattern.
- Contact reliability is improved by stacking and firing Pd-based conductor paste, and the Ag contact material of the sliding contact is replaced with 30 to 50 wt% Ag-Pd to prevent sulfurization.

However, since the thick film conductor pattern and the contact material are the same type of combination, adhesion and peeling easily occur, accelerating wear. Also, the contact material of Ag-Pd 30~50wt% has Hv 160~
200 is too hard, whereas the thick film conductor pattern, which is a baked product of Ag-Pd-based conductor paste, is soft, resulting in increased wear and premature end of life. Furthermore, Ag-Pd30~
The 50wt% contact material has an electrical conductivity (IACS3.8-5
．． 5%), there were problems such as heat generation.

(Object of the Invention) An object of the present invention is to provide a sliding contact device that can solve the above problems.

(Means for Solving the Problems) A sliding contact device of the present invention for solving the above-mentioned problems includes forming a thick film resistance pattern by firing a resistance paste on a ceramic substrate, and forming a thick film resistance pattern on a ceramic substrate. A wiring board formed by connecting to a resistor pattern and firing an Au conductor paste to form a thick film conductor pattern, and a wiring board configured to be able to slide against the thick film conductor pattern of the wiring board 50
The present invention is characterized in that the contact material of wt% is constituted by a sliding contact formed by being attached to a spring terminal material.

In the sliding contact device of the present invention, the contact material of the sliding contact is A
The reason for setting g-MOIO to 50-1% is that MOIO in Ag
If it is less than 10 wt%, the lubricating effect will be weak, and adhesion and peeling will occur when the sliding contact contacts the thick Au conductor pattern on the ceramic substrate, and if it exceeds 50 wt%, it will cause noise. It is from.

(Function) In the sliding contact device configured as described above, in the contact action between the sliding contact and the thick film conductor pattern on the ceramic substrate, the hardness of the Ag-Mo 10 to 50 wt% contact material of the sliding contact is HV80 to 140). Since it is soft and slippery, the contact resistance is low and stable, and the Au thick film conductor pattern is not damaged, and there is almost no adhesion or peeling, reducing wear, so good contact can be obtained. . Furthermore, A g −M of the sliding contact.

Electrical conductivity of 10-50wt% contact material is lAC340~
Since it is a good 60%, it does not generate heat.

(Example) To explain an example of the sliding contact device of the present invention, as shown in the figure, a 98% pure Al having a plate thickness of 0.6 and a diameter of 3011 mm is used.
A resistor paste of RuOt is screen printed on the outer periphery of the zOs substrate 1 in a width of 3 squares, and baked at 800°C to form a thick film resistor pattern 2 with a thickness of 10μ, and connected to the thick film resistor pattern 2. Then, an Au conductor paste was screen printed in the circumferential direction and fired at 800°C to form a thick film conductor pattern 3 having a width of 0.2 mm, a length of 7 mm, and a thickness of lOμ at 0.2 mm intervals. A wiring board 4 was obtained. On the other hand, the two types of sliding contacts 5, which are slidably opposed to the thick film conductor pattern 3 of the wiring board 4, are made of two types of contact wires (diameter 3 cranes)
Two types of rivet contacts 6 made from It is inserted into a contact mounting hole of a spring terminal material 7 made of Be-Cu and is secured.

The sliding contact device of Example 1.2 configured in this way,
A conventional sliding contact device consisting of a sliding contact having a contact material of 30 wt% Ag-Pd and a thick film conductor pattern of 30% 1t% Ag-Pd on a wiring board was subjected to sliding opening and closing under the following test conditions. When the test was conducted, the results shown in the table below were obtained.

Test conditions Contact crab 10g, operation 2 rotation reciprocating type (55 degrees), drive 2 60 strokes/min% energization: 12■, 10
0 mA As is clear from the table above, the sliding contact device of Example 1.2 has a lifespan almost twice as long as that of the conventional sliding contact device. This is just the Ag- of the sliding contact 5.
MOIO~50wt% Since the hardness of the contact material is soft and slippery, there is no damage to the opposing Au thick film conductor pattern 3 (and there is no adhesion or peeling, reducing wear. This is because the contact material containing 10 to 50 wt% Mo has good electrical conductivity and does not generate heat.

Note that the above-mentioned lifespan is due to wear of the thick film conductor pattern 3.
The judgment was made based on the case where the sliding contact 5 came into contact with the /1z03 substrate and became an open state B (infinite contact resistance), and the case where a short circuit occurred due to clogging of the slit between the thick film conductor patterns 3.

Although the wiring board 4 of the sliding contact device in the above embodiment is circular, it may also be rectangular. In that case, the thick film resistor pattern is preferably formed at one end of a rectangular wiring board, and the thick film conductor patterns are preferably connected to the thick film resistor pattern and formed parallel to it at regular intervals in its longitudinal direction. The sliding contact is slidable in the longitudinal direction of the thick film resistor pattern, facing the thick film conductor pattern. In addition, a thick film resistor pattern is formed on a ceramic substrate in a bellows shape and reciprocated back and forth, and a wiring board is formed on which thick film conductor patterns are arranged at regular intervals, and the wiring board faces the thick film conductor pattern. It is also possible to use a sliding contact device consisting of a sliding contact that is slidable.

(Effects of the Invention) As can be seen from the above explanation, the sliding contact device of the present invention has a hardness of 6 to 12 wt% of Ag-tin oxide in the sliding contact and has a hardness of HV80.
~140) is soft and slippery, so the Au thick film hot body pattern on the ceramic substrate is not worn out during contact action, and adhesion and peeling are almost eliminated, reducing wear, so good contact is achieved. can get.

Therefore, the contact reliability is improved and the life of the sliding contact device is significantly extended. Furthermore, Ag M is a sliding contact.

Since the electrical conductivity of the 10-50wt% contact material is good, no heat is generated during contact action, and welding is less likely to occur.

Therefore, the welding resistance of the sliding contact device is significantly improved.

[Brief explanation of the drawing]

The figure is a schematic perspective view showing an embodiment of the sliding contact device of the present invention.

Claims (1)

[Claims] A wiring board in which a thick film resistor pattern is formed by firing a resistor paste on a ceramic substrate, and a thick film conductor pattern is formed by firing an Au conductor paste connected to the thick film resistor pattern, and this wiring. Ag-Mo10~50wt, made to be able to slide against the thick film conductor pattern of the plate
1. A sliding contact device comprising: a sliding contact in which the contact material is attached to a spring terminal material.