JPH05234720A - Layered resistor precursor - Google Patents

Abstract

PURPOSE:To enhance oxidation resistance by installing trimming patterns to be connected to conductor patterns in parallel between layered ceramic sheets. CONSTITUTION:There are superposed on one another a coat layer C, a ceramic sheet 10 provided with a conductor pattern 11, a ceramic sheet 20 provided with a conductor pattern 21, a trimming pattern T1 and T2 connected thereto in parallel and a ceramic sheet 30 provided with a conductor pattern 31. The conductor patterns 11, 21 and 31 are electrically connected in series by way of through holes of the ceramic sheets. The end face A of this resistor precursor is polished only by a specified length. The trimming pattern T1 or T2 is cut so that it is possible to obtain a layered resistor which is finely controlled to meet a specified resistance value. Furthermore, the trimming pattern cutting portion can be separated from the conductor pattern to a satisfactory extent. It is therefore, possible to enhance oxidation resistance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to, for example, a temperature sensor,
The present invention relates to a laminated resistor used in a sensor such as a flow sensor or a level sensor that detects a change in resistance value.

[0002]

2. Description of the Related Art Japanese Unexamined Patent Publication (Kokai) No. 64-65427 discloses a platinum temperature sensor in which a platinum resistance pattern is provided between a plurality of flat ceramic sheets, and the resistance value of this sensor is adjusted on the outermost side. It is described that the exposed resistance adjusting line (trimming pattern) applied and fired on the ceramic sheet is cut.

[0003]

As in the platinum temperature sensor described in the above publication, a trimming pattern for finely adjusting the resistance value of the entire resistor by electrically connecting to the resistance pattern and cutting it is provided on the surface of the laminated resistor. In the case of 1), after the trimming pattern is cut, the cut portion is likely to be oxidized.
Therefore, W or the like cannot be used as a trimming pattern, and only a noble metal (for example, Pt or the like) having good oxidation resistance can be used.

Further, since the ceramic sheet having the trimming pattern of the platinum temperature sensor described in the above publication has many through holes, cracks are likely to occur in the patterns of the through holes. Therefore, it is difficult to use under severe temperature cycle conditions or high temperature. further,
Mass production is not easy.

An object of the present invention is to provide a laminated resistor which solves the problems of the above conventional techniques.

[0006]

According to the present invention, the above object can be achieved by the following laminated resistor precursor and method for producing a laminated resistor.

A laminated resistor precursor comprising a conductor pattern, a trimming pattern connected in parallel to the conductor pattern, and a ceramic sheet, and having the trimming pattern between the laminated ceramic sheets.

A method for manufacturing a laminated resistor, wherein the trimming pattern of the laminated resistor precursor is removed together with ceramics.

The conductor pattern and the trimming pattern connected in parallel with the conductor pattern are in a state of being embedded in the ceramic, and the pattern area exposed by cutting is small, and the durability is high. Further, by providing the trimming pattern extending to a region close to the end face, the trimming pattern can be easily cut.

Preferably, two or more trimming patterns having different distances from the end face are provided. With this, the resistance value can be changed stepwise according to the polishing distance from the end surface,
The resistance range that can be trimmed becomes wider. Also, these trimming patterns need not necessarily be provided between common ceramic sheets.

Preferably, three or more ceramic sheets having conductor patterns are laminated. With this structure, the resistance value can be increased, and the heat generation of the conductor pattern portion that occurs when converting the change in the resistance value into the output of voltage or the like can be prevented.

[0012] Preferably, a method of obtaining a laminated resistor precursor by laminating the green sheets on which the respective patterns are formed and simultaneously firing them together has high mass productivity.

As means for trimming, the ceramic portion having the trimming pattern is cut or ground. With this method, the area of the trimming pattern exposed by cutting or the like is very small, and the durability is excellent.

As a method of further reducing the exposure of the pattern, it is sufficient to mold the cut portion, for example, sealing molding with glass. Usually, it is convenient to provide a trimming pattern on the output extraction side that is molded as a sensor. good.

Further, the conductor pattern and the trimming pattern may be mainly composed of metal, and W, Pt or the like can be used. However, Pt is particularly excellent as a material that can withstand high temperatures and the like.

[0016]

EXAMPLE 1 An example of a laminated resistor precursor of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view of an example of a laminated resistor precursor of the present invention, and FIG. 2 is a plan view showing the precursor of FIG. 1 exploded for each ceramic sheet.

The resistor precursor shown in FIG. 1 includes a coat layer C, a ceramic sheet 10 provided with a conductor pattern 11, a ceramic sheet 20 provided with a conductor pattern 21 and trimming patterns T1 and T2 connected in parallel therewith. The ceramic sheets 30 provided with the conductor patterns 31 are laminated. The conductor patterns 11, 21, and 31 are electrically connected in series through the through holes of the ceramic sheet. Further, a terminal pattern 02 is formed on the surface of the coat layer C and is connected to the conductor pattern via a through hole, and a terminal pattern 32 is formed on the opposite surface (exposed surface) of the ceramic sheet 30 through the through hole. Connected to the conductor pattern 31.

The laminated resistor has a trimming pattern T1 obtained by polishing the end face A of the resistor precursor of FIG. 1 by a predetermined length L.
It can be obtained by finely adjusting to a desired resistance value by cutting T2 to T2. This will be described with reference to FIG.

FIG. 3 shows a conductor pattern 21 provided on a ceramic sheet 20 (not shown) and trimming patterns T1 and T2 connected in parallel with the conductor pattern 21. By setting the polishing distance L from the end surface A in FIG. 1 to a, only the trimming pattern T1 can be cut, and by setting the polishing distance L to b, both the trimming patterns T1 and T2 can be cut. .. Therefore, by polishing the resistor precursor, it is possible to obtain a laminated resistor whose resistance value is changed.

Since the trimming pattern cut portion of the obtained laminated resistor can be sufficiently separated from the conductor pattern, the oxidation resistance can be improved.

(Embodiment 2) FIG. 4 is a plan view showing a ceramic sheet 40 which can be used in place of the ceramic sheet 20 having the conductor pattern 21 and the trimming patterns T1 and T2 shown in FIG.

The ceramic sheet 40 has a conductive pattern 4
1 and the trimming pattern T3, the trimming pattern T3 is connected in parallel with the conductor pattern 41, and reaches the vicinity of the end face B on the lead extraction portion side. When the ceramic sheet 40 is used instead, the end surface on the lead-out portion side can be ground by the length L'and the trimming pattern T3 can be cut to change the resistance value of the resistor.

By molding (glass sealing) the lead-out portion side of the resistor precursor during assembly, the cut end face of the trimming pattern T3 is not exposed on the surface, so that the oxidation resistance can be further improved. ..

(Embodiment 3) FIG. 5 is a view showing an end face of another embodiment of the laminated resistor precursor according to the present invention.

B, C, D, E and F are conductor patterns in which trimming patterns are connected in parallel, and A and G
Is a conductor pattern having no trimming pattern. These patterns exist between the ceramic sheet S and the coat layers C1 and C2, and are electrically connected through the through holes.

When the thickness of the layers is increased in this way,
More accurate and easy trimming.

The shape of the laminated trimming patterns does not have to be constant, and the length of each trimming pattern, the number of trimming patterns, the distance between the trimming patterns and the end face, etc. can be changed.

[0029]

Since the laminated resistor precursor of the present invention has the trimming pattern connected in parallel to the conductor pattern between the laminated ceramic sheets, the distance between the cut portion of the trimming pattern and the conductor pattern is sufficiently large. It can be taken and the oxidation resistance can be improved. Further, when coating the trimming pattern cut portion, the amount of the coating agent (for example, glass) can be reduced.

In the method for manufacturing a laminated resistor according to the present invention, the trimming pattern of the laminated resistor precursor of the present invention in which the trimming pattern connected in parallel to the conductor pattern is provided between the laminated ceramic sheets is cut. By scraping off the end faces of the laminated body, a large number of laminated resistors can be manufactured easily.

When a precursor having the same resistance value is trimmed to the target resistance value, the precursors can be piled up in several stages and the end faces can be ground, resulting in high mass productivity.

[Brief description of drawings]

FIG. 1 is a perspective view of an example of a laminated resistor precursor of the present invention.

FIG. 2 is a plan view showing the precursor of FIG. 1 exploded for each ceramic sheet.

FIG. 3 is a diagram illustrating cutting of a trimming pattern.

FIG. 4 is a plan view showing a ceramic sheet having a conductor pattern and a trimming pattern.

FIG. 5 is a view showing an end face of another embodiment of the multilayer resistor precursor of the present invention.

Claims (5)

[Claims] 1. A laminated resistor precursor comprising a conductor pattern, a trimming pattern connected in parallel to the conductor pattern, and a ceramic sheet, the trimming pattern being provided between the laminated ceramic sheets. 2. The laminated resistor precursor according to claim 1, wherein the trimming pattern is provided in a region near an end face. 3. The trimming pattern having two or more different distances from the end face is provided.
The laminated resistor precursor according to item 1. 4. A method of manufacturing a laminated resistor, wherein the trimming pattern of the laminated resistor precursor according to claim 1 is cut together with a ceramic. 5. The method of manufacturing a laminated resistor according to claim 4, wherein the laminated end face of the precursor is removed and the trimming pattern is cut together with the ceramic.