CN111272056B

CN111272056B - High-temperature eddy current sensor and manufacturing method thereof

Info

Publication number: CN111272056B
Application number: CN202010243871.1A
Authority: CN
Inventors: 余苗; 包绍明; 黄涛; 李婷
Original assignee: Chengdu Kerui Sensing Technology Co ltd
Current assignee: Chengdu Kerui Sensing Technology Co ltd
Priority date: 2020-03-31
Filing date: 2020-03-31
Publication date: 2021-12-10
Anticipated expiration: 2040-03-31
Also published as: CN111272056A

Abstract

The invention discloses a high-temperature eddy current sensor which comprises an upper end assembly and a lower end assembly, wherein the lower end assembly comprises a ceramic substrate, a lower shell and a core body, the core body is fixed on the ceramic substrate to form a core body assembly, the core body assembly is installed in the lower shell, the upper end assembly comprises a cable, a metal connecting terminal and an upper shell, one end of the metal connecting terminal is fixed in the upper shell after being fixed with the cable, the upper end assembly and the lower end assembly are welded into a whole after being pressed, the other end of the metal connecting terminal is connected with the core body, the core body is formed by stacking and pressing and then gluing and sintering a plurality of layers of ceramic substrates, and each layer of ceramic substrate is printed with a conductor in a silk screen mode. A method of manufacturing a high temperature eddy current sensor is also disclosed. The conductor is directly printed on the ceramic substrate and is formed by one-time sintering after multilayer superposition, and the working temperature of the ceramic eddy current sensor manufactured by the technology can reach more than 800 ℃; and the assembly is simple, and the method is suitable for mass production.

Description

High-temperature eddy current sensor and manufacturing method thereof

Technical Field

The invention relates to the technical field of eddy current sensors, in particular to a high-temperature eddy current sensor and a manufacturing method thereof.

Background

The eddy current sensor is a mainstream product for displacement measurement at present, has high precision and reliability, is convenient to install, and is an indispensable sensor in the industrial society. However, the sensing element (core) adopted by the current eddy current sensor is a coil wound by a conductor, and because the insulation temperature of a conducting wire is limited, the usable temperature range of most sensors is very low and is generally not higher than 180 degrees.

Disclosure of Invention

The invention aims to provide a high-temperature eddy current sensor and a manufacturing method thereof, which are used for solving the problem that the eddy current sensor in the prior art cannot resist high temperature because the temperature of a coil wound by a sensitive element conductor is limited.

The invention solves the problems through the following technical scheme:

the utility model provides a high temperature eddy current sensor, includes upper end subassembly and lower extreme subassembly, the lower extreme subassembly includes ceramic base member, lower shell and core, the core is fixed and is formed the core subassembly on ceramic base member, the core subassembly is installed under in the shell, the upper end subassembly includes cable, metal connecting terminal and last shell, metal connecting terminal's one end is fixed to in the shell after with the cable is fixed, weld into wholly again after upper end subassembly and the crimping of lower extreme subassembly, metal connecting terminal's the other end is connected with the core, the core is formed by the sintering of arranging glue behind stack of multilayer ceramic substrate, the crimping, every layer screen printing has the conductor on the ceramic substrate.

A method of manufacturing a high temperature eddy current sensor, comprising:

step S100: manufacturing a plurality of ceramic substrates, and punching holes on the ceramic substrates;

step S200: printing a conductor on a ceramic substrate in a screen printing mode;

step S300: superposing a plurality of ceramic substrates, carrying out isostatic pressing and pressing, cutting according to the design size of the sensor, and then carrying out glue discharging and sintering to form a core body;

step S400: the core body and the ceramic substrate are fixed and then installed in the lower shell, the metal connecting terminal and the cable are connected and then fixed in the upper shell, and the upper shell and the lower shell are pressed and laser welded into a whole.

The conductor may be provided with a width of 0.02mm-0.25mm and a thickness of 0.01mm-0.1 mm. The shape of the conductor may be spiral, square or circular. The conductor may be made of one or more of platinum, gold, palladium, gold, silver and copper.

The thickness of the ceramic substrates can be 0.02mm-0.1mm, and the number of superposed layers of the ceramic substrates is 2-100.

The binder removal temperature is 300-1000 ℃, and the sintering temperature is 800-2000 ℃.

The ceramic substrate may be tape cast or dry pressed.

Compared with the prior art, the invention has the following advantages and beneficial effects:

the conductor is directly printed on the ceramic substrate and is formed by one-time sintering after multilayer superposition, and the working temperature of the ceramic eddy current sensor manufactured by the technology can reach more than 800 ℃; and the assembly is simple, and the method is suitable for mass production.

Drawings

FIG. 1 is a schematic structural view of the present invention;

wherein 100-core; 200-a ceramic matrix; 300-a lower housing; 400-an upper housing; 500-metal connection terminals; 600-cable.

Detailed Description

The present invention will be described in further detail with reference to examples, but the embodiments of the present invention are not limited thereto.

Example 1:

combine shown in fig. 1, a high temperature current vortex sensor, including upper end subassembly and lower extreme subassembly, the lower extreme subassembly includes ceramic matrix 200, lower shell 300 and core 100, core 100 fixes and forms the core subassembly on ceramic matrix 200, the core subassembly is installed under in shell 300, the upper end subassembly includes cable 600, metal connecting terminal 500 and last shell 400, press into again after metal connecting terminal's one end and the cable welding or weld in last shell 400, laser welding becomes whole again after upper end subassembly and the crimping of lower extreme subassembly, metal connecting terminal's the other end is connected with the core, core 100 is formed by the sintering of arranging glue after the stack of multilayer ceramic substrate, crimping, every layer screen printing has the conductor on the ceramic substrate. Preferably, the core 100 is stacked with 8 ceramic substrates, which are respectively a first ceramic substrate to an eighth ceramic substrate, and the conductor on each ceramic substrate is in a spiral coil shape, which is a 6-turn spiral coil, and the total number of the conductors is 48 coil combinations. The upper shell and the lower shell can be made of stainless steel, and an excitation circuit of the high-temperature eddy current sensor is arranged outside. The upper end subassembly, the lower extreme subassembly of core 100 are all high temperature resistant, and operating temperature is not less than 800 degrees centigrade, and the upper end subassembly is connected through laser welding with the lower extreme subassembly and is formed, also can bear high temperature. The sensor integrates the core body, is simple to assemble and is beneficial to mass production.

Example 2:

a method of manufacturing a high temperature eddy current sensor, comprising:

step S100: preparing a plurality of ceramic substrates, wherein the main component of the ceramic substrates can be any one of alumina, zirconia, aluminum nitride and silicon nitride, and the method for preparing the ceramic substrates can adopt a dry pressing mode, namely pressing the ceramic substrates by a model after powder is made into a powder material; one is tape casting, namely, the powder is made into slurry and is cast into a ceramic substrate by a tape casting machine; the thickness of the ceramic substrate may be 0.02mm-0.1 mm; punching holes, such as positioning holes, filling holes or via holes, on the ceramic substrate by adopting mechanical punching or laser;

step S200: printing a conductor on a ceramic substrate in a screen printing mode; the width of the conductor may be 0.02mm to 0.25mm and the thickness may be 0.01mm to 0.1 mm. The shape of the conductor may be spiral, square or circular. The main component of the conductor material can be made of one or more materials of platinum, gold, palladium gold, silver and copper; the number of turns of the spiral may be 2 to 100 turns; the conductors are silk-screened very thin, about 0.002, and because the base material is very soft, it is embedded inside and does not affect the thickness.

Step S300: sequentially stacking a plurality of layers of ceramic substrates subjected to screen printing on the substrate through positioning holes, wherein the number of stacked layers is 2-100, and the total thickness is 0.04-10 mm; then carrying out isostatic pressing on the steel sheet, wherein the pressure is not lower than 10 Mpa; cutting according to the design size of the sensor, and then carrying out glue discharging and sintering to form a core body; the binder removal aims at eliminating organic matters in the ceramic material, the binder removal temperature range is 300-1000 ℃, and the binder removal is finally sintered into an integrated ceramic sensitive element, namely a core body, wherein the sintering temperature range is as follows: 800-2000 ℃. The step can be sintering after the binder removal, or sintering after the binder removal;

step S400: the core and the ceramic substrate are fixed by glass sintering and then mounted in the lower case 300 made of stainless steel, the metal connection terminal 500 is connected to the cable 600 and then fixed in the upper case 400 made of stainless steel, and the upper case 400 and the lower case 300 are pressed and laser-welded into a whole.

Although the present invention has been described herein with reference to the illustrated embodiments thereof, which are intended to be preferred embodiments of the present invention, it is to be understood that the invention is not limited thereto, and that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this disclosure.

Claims

1. The utility model provides a manufacturing method of high temperature current vortex sensor, its characterized in that, high temperature current vortex sensor includes upper end subassembly and lower extreme subassembly, the lower extreme subassembly includes ceramic base member, lower shell and core, the core is fixed and is formed the core subassembly on the ceramic base member, the core subassembly is installed in the shell down, the upper end subassembly includes cable, metal connecting terminal and last shell, metal connecting terminal's one end and cable are fixed after fixed in the shell, weld into whole again after upper end subassembly and the crimping of lower extreme subassembly, metal connecting terminal's the other end is connected with the core, the core is formed by multilayer ceramic substrate stack, the sintering of binder removal after the crimping, every layer screen printing has the conductor on the ceramic substrate, and the method includes:

2. A method of manufacturing a high temperature eddy current sensor as claimed in claim 1, wherein the conductor has a width of 0.02mm to 0.25mm and a thickness of 0.01mm to 0.1 mm.

3. A method of manufacturing a high temperature eddy current sensor according to claim 1, wherein the conductor is in the shape of a spiral, square or circle.

4. A method for manufacturing a high-temperature eddy current sensor according to claim 1, wherein the conductor is made of one or more of platinum, gold, palladium, silver and copper.

5. A method for manufacturing a high temperature eddy current sensor according to claim 1, wherein the ceramic substrate has a thickness of 0.02mm to 0.1 mm.

6. A method for manufacturing a high-temperature eddy current sensor according to claim 1, wherein the number of stacked ceramic substrates is 2 to 100.

7. The method of claim 1, wherein the binder removal temperature is 300 ℃ to 1000 ℃ and the sintering temperature is 800 ℃ to 2000 ℃.

8. A method for manufacturing a high-temperature eddy current sensor according to claim 1, wherein the ceramic substrate is cast or dry-pressed.