JPS61105804A - Thermistor element and manufacuture 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 [Field of Industrial Application] The present invention relates to a thermistor element, and more particularly to a glass-sealed thermistor element used as a sensor and a method for manufacturing the same.

[Conventional technology]

A thermistor has the characteristic that its electrical resistance changes significantly when the temperature changes, and in particular has a negative temperature coefficient, which means that the electrical resistance decreases as the temperature rises.
Negative Temperature 0oef
(ficent) Thermistors are used in various fields, and one of their uses is for temperature measurement.

9 as a conventional measurement thermistor, for example, Japanese Patent Publication No. 52-7
As described in Publication No. 535.

A heat-resistant conductive paint is baked on both sides of the thermistor chip to provide electrodes, and the base of a metal lead wire is connected to the electrode using the heat-resistant conductive paint.

This is sealed in glass.

[Problems to be solved by the invention]

In this case, as shown in Figures 3 (α) to (C), a heat-resistant conductive paint CA, y is applied to the surface of the thermistor chip 10.

Pdkf, Pi, Au, etc.) thick film electrode 11.
11, metal lead wires 12 and 12 are similarly fixed thereto with heat-resistant conductive paint 13.

In this case, when KUF was used as the thick film electrode 11, AW had to be used as the heat-resistant conductive paint for fixing the metal lead wire 12.

If another metal is used as the heat-resistant conductive paint to fix the metal lead wire 12, and the metal does not form an ohmic contact surface with the thermistor chip 10, in the case of glass sealing. When heated, this non-ohmic contact material diffuses into the thick film electrode 11, changing the contact state, resulting in variations in resistance and poor reliability.

9. Usually, expensive ATL or Pt is used as the thick film electrode 11. Conductive materials other than Ku, Pt, and Pt do not provide good results in terms of heat resistance (oxidation resistance), reliability, and voltage (current) dependent characteristics (non-ohmic contact).

[Means to solve all problems]

In order to solve the above-mentioned problems, there is no invention.

A thick film electrode and a block electrode are formed on the thermistor chip, and electrical contact is maintained with a lead wire on the block electrode using a fritless heat-resistant groove TA paste.

And all of these were covered with glass.

Because of the glass coating, the metal in the fritless heat-resistant conductive box paste that fixes the lead wires even when heated is blocked by the block electrode and does not diffuse into the thick film electrode on the thermistor chip. Cheap conductive materials other than Am and Pt (Ay, pdA) can be used as conductive pastes.
,! Even if 7) is used, Au.

Results equivalent to those of Pt can be obtained, and manufacturing costs can be reduced.

〔Example〕

An embodiment of the present invention will be described based on FIG.

FIG. 1 (α) shows a glass-sealed thermistor element having multiple configurations according to the present invention, FIG. 1 (h) shows its cross-sectional view, and FIG. This is an enlarged part of the electrode.

In FIG. 1, thick film electrodes 2 and block electrodes 3 are formed on both sides of a thermistor chip 1. As the thermistor chip 1, for example, a MAL-Ni-Co type one is used. A lead wire 4 is bonded to the surface of the block electrode 3 with a heat-resistant conductive material 5). These parts are then covered with glass 6.

The thick film electrode 2 is formed by printing and baking a fritless ATL thick film conductive paste made of Pt. This makes it possible to provide an electrode that makes good ohmic contact with the thermistor chip 1.

When the block electrode 3 is sealed with glass, the metal for fixing the lead wire diffuses into the thick film electrode 2, and the good ohmic contact characteristics between the thick film electrode 2 and the thermistor chip 1 are deteriorated. For example, Cr
, a thin film electrode deposited with Ni, W, Mo, etc.f), a plated electrode plated with Ni.

Lead wires 4, 4 are fixed to the thus formed block electrodes 3, 3 with a fritless heat-resistant conductive paste of Ag or Pd hl, for example.

This lead wire 4 is a Dumet wire using a pg-Ni alloy as a core wire and coated with Qu.

These are then covered with glass 6. This glass 6
is 5iOz -PbO-K20 system or 5iOz -
A PAO-K2O-Nα20 type is used. In this way, the glass-sealed thermistor element shown in FIG. 1 can be constructed.

Next, let's talk about the manufacturing method of this thermistor element.

This will be explained using Figure 2.

■ First, transition metal oxide (Mn −N i −co −
oxides such as At-pe-Q u) are weighed and prepared at a predetermined metal molar ratio.

■ Add the oxide material and pure water to the weighed and mixed mixture in a ball mill pot and mix for a certain period of time.

■ Dehydrate and dry this mixed material.

■ The dried material is calcined at a temperature of 800°C to 1000°C.

■Put the pre-fired material into a vibrating mill container, add pure water, and grind for a predetermined period of time to form a fine powder.

(2) Place the finely powdered material in a mortar, add water or a suitable binder such as PVA (polyvinyl alcohol), and shape the mixture into a predetermined size.

■ After molding, it was heated in an A i r atmosphere for 1200 minutes.
Main firing is performed at a temperature of 0 to 1400°C.

■ The sintered material (ingot) obtained through main firing is sliced and cut into wafers. Then, use a precision flat tool to cut the wafer to a predetermined thickness, e.g. 0.15~
0.501km).

■ After cleaning the wafer that has been precisely surface-finished in this way, it is washed with A11. Alternatively, a 2.2 ft thick film electrode is first formed by printing and sintering a Pt thick film conductive paste (fritless). Then, install this in a high vacuum evaporation equipment and set the wafer substrate temperature to 200°C~4.
The temperature is set to 00''C, the degree of vacuum is set to 10'TORR or higher, and a thin film electrode that will become the block electrode 3 is vapor-deposited.The metal to be vapor-deposited at this time is at least one of O?-, Ni, W, and MO. In addition, the block electrode 3 may be formed by a plating electrode completely shimmed with Ni, instead of forming the vapor-deposited thin film electrode.

[Phase] The entire wafer on which the vapor-deposited thin film electrodes have been formed is cut into chips by dicing to obtain thermistor chips.

■ Attach the end of a lead wire made of Dumet wire whose core wire is O coated with Fs-Ni alloy to the block electrode part of this thermistor chip with a heat-resistant conductive paste (fritless) of Ag or PdAgI and dry bond it. .

■Then, the entire chip to which the lead wires are attached is coated with glass using a glass sealing machine.

In this way, a glass-sealed thermistor element as shown in FIG. 1 can be obtained.

〔Effect of the invention〕

According to the present invention, it is possible to effectively prevent the metal of the heat-resistant conductive paste with the lead wire fixed into the thick film electrode from being diffused by the block electrode.

Therefore, as a heat-resistant conductive paste for fixing this lead wire, a material other than the thick film electrode, kW, A other than Pt,! 7. P
dA! Even if conductive materials such as I are used, reliability and voltage (
Current) dependent characteristics (non-ohmic contact), Au,, Pt
You can get the same results as using .

As a result, conductive materials other than AtL and Pt (A and P
dA4 paste) can be used, and production costs can be reduced.

[Brief explanation of drawings]

Figures 1 and 1 are configuration diagrams of an embodiment of the present invention, Figures 1 and 2 are explanatory diagrams of a method of manufacturing the thermistor element of the present invention, and Figures 1 and 3 are entire illustrations of a conventional thermistor element. 1... Thermistor chip 2... Thick film electrode 3.
...Block electrode 4...Lead wire 5...
Heat-resistant conductive material 6...Glass patent applicant TDC Co., Ltd. agent Patent attorney Yamatani
Akira Ei Procedural Amendment (Voluntary) January 16, 1985 Manabu Shiga, Commissioner of the Patent Office 1, Indication of Case Patent Application No. 228439, 1988 2
, Title of the invention Thermistor element and method for manufacturing the same 3.1
Relationship with the case of those who commit illegal acts Patent applicant address: 13-1 Nihonbashi-chome, Chuo-ku, Tokyo Name
(306) TDC Co., Ltd. Representative Daitoshi
Kan 4, Agent Address: 1-19-8-6 Kanda Awajicho, Chiyoda-ku, Tokyo
, Subject of amendment The claims of the specification, Contents of amendment to the invention (2), and the claims from page 1, line 5 of the specification to page 2, line 10, are amended in full as follows. [1. A thermistor characterized in that a thick film electrode and a block electrode are formed on a thermistor chip, electrical contact is maintained with a lead wire on the block electrode using a heat-resistant conductive paste, and these are covered with glass. element. 2. Au and PT are used as the thick film electrode. As the block electrode, Cr, Ni+W+M
2. The thermistor element according to claim 1, wherein Ag or PdAg is used as the heat-resistant conductive paste. 3. After molding and sintering the powder material into a disk shape. On a thermistor material substrate whose surface has been precisely machined into a wafer shape, a thick film conductive paste or paste is printed and sintered to form a thick film electrode, and then a thin film block electrode is deposited on top of it. Alternatively, it is formed by plating, processed into a thermistor chip, electrical contact is maintained with a lead wire on the block electrode surface of this thermistor chip with fritless heat-resistant conductive paste, and then the thermistor chip and the lead are A method for manufacturing a thermistor element, characterized in that a wire is covered with glass. 4. The method of manufacturing a thermistor element according to claim 3, wherein a Ni plating electrode film is formed as the block electrode. ”2, p. 9, line 14 rAwJ
is corrected as rAuJ. 3. Correct the number 6 in Figure 1 fbl of the drawings to 4 as shown in red on the attached sheet. Figure 1 above

Claims (1)

[Claims] 1. A thick film electrode and a block electrode are formed on the thermistor chip, electrical contact is maintained with a lead wire on the block electrode using a heat-resistant conductive paste, and these are covered with glass. A thermistor element characterized by: 2. The thick film electrode is made of Au or Pt, the block electrode is made of at least one of Cr, Ni, W, or Mo, and the heat-resistant conductive paste is made of Ag or Pd.
The thermistor element according to claim 1, characterized in that Ag is used. 3. After molding and sintering the powder material into a disk shape, a thick film conductive splitless paste is printed and fired on a thermistor material substrate whose surface has been precisely processed into a wafer shape to form a thick film electrode. Then, a thin film block electrode is formed on top of it by vapor deposition or plating, this is processed into a thermistor chip, and a lead wire is connected to the block electrode surface of this thermistor chip using a fritless heat-resistant conductive paste. maintain contact, then this thermistor
A method for manufacturing a thermistor element, characterized in that the chip and lead wires are covered with glass. 4. The method of manufacturing a thermistor element according to claim 3, wherein a Ni plating electrode film is formed as the block electrode.