JPH02245617A - Heating element of sensor - Google Patents

Abstract

PURPOSE:To enable detection suited to mass production and accurate by providing each of a plurality of base bodies having protruding shapes while protruding sections thereof are not connected to each other with one or a plurality of heating elements. CONSTITUTION:A square sensor substrate 1 has two notch sections formed parallel with a long side from a short side thereof so that it 1 is forked in shape and three protruding sections 3a-3c are formed. The protruding sections 3a-3c are not connected together and separated from one another with the notches 2. Therefore, a temperature compensation resistance 7 provided at the protruding section 3a, heating film bodies 6a and 6b provided at the protruding section 3b and a detection resistance 11 provided at the protruding section 3c are insulated thermally from one another to prevent thermal effect thereamong. In addition, elements of the resistance 11, the heating film bodies 6a and 6b and the compensation resistance 7 are provided at the protruding sections 3a-3c of the substrate 1 the same in material and shape and hence, they can be formed by the same process such as print baking thereby achieving a higher mass productivity.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application] The present invention relates to a heating element for a sensor that detects various physical quantities.

[Prior Art] Conventionally, such a sensor requires various resistances in addition to the sensor portion to detect flow rate and temperature, such as a resistor for detecting voltage and current, a compensation resistor, a voltage dividing resistor, and the like.

FIG. 7 shows a conventional flow rate measurement sensor, in which a heating element 51 and a temperature compensation resistance element 52 of the sensor part are provided inside a sensor holder 53, and this sensor holder 53 is connected to a ? There are 5 LR walls and 4 internal walls. A resistor for detecting the amount of current flowing through the heating element 51 is connected to the heating element 51, and this detection resistor detects the amount of current flowing through the heating element 51 because the current flowing through the heating element increases as the flow rate of the fluid increases. The amount of heat generated by the detection resistor also increases, requiring cooling. Therefore, this detection resistor is connected to the metal wire 55.
The metal wire 55 was wound around the outer surface of the proximal end of the sensor holder 53 and exposed to a fluid to be cooled.

[Problems to be Solved by the Invention] However, winding the metal wire around the sensor holder is extremely time-consuming and expensive, and is not suitable for mass production.

In addition, installing a detection resistor near a heating element or a temperature-compensating resistance element, or installing a heating element near a temperature-compensating resistance element, is useful for detecting the flow rate of the heating element and the temperature of the temperature-compensating resistance element. This had a negative impact on the environment and hindered accurate detection.

The present invention was made to solve the above-mentioned problems, and is suitable for mass production, has low manufacturing costs, and, when there are multiple heating elements, can reliably insulate between each heating element and accurately The object of the present invention is to provide a heating element for a sensor that can perform accurate detection.

[Means for Solving the Problems] In order to achieve the above object, in the present invention, one or more heating elements are provided for each of a plurality of bases having a protruding shape and whose protruding portions are not connected to each other. It is something that

[Function] As a result, the protruding parts of each base are not connected to each other, so the heat from each heat generating element of each base is not transmitted to other heat generating elements via the base, making it difficult to perform accurate detection. can. Furthermore, since each heating element is provided on the same base, the work of providing each heating element on each base can be performed in the same pattern, making it suitable for mass production.

Here, the heating element refers to a detection resistor, a heating element for flow rate detection,
Includes everything that generates heat in the sensor, such as temperature compensation resistors.

[Example] Hereinafter, an example embodying the present invention will be described with reference to the drawings.

FIG. 1 shows the front and back surfaces of a sensor substrate 1 of a thermal flow rate measurement sensor, and FIG. 2 is a diagram showing the manufacturing process of this thermal flow rate measurement sensor. The sensor substrate 1 is a rectangular plate with a length of several centimeters, a width of several millimeters, and a thickness of 0.3 to 1.5 mm, and is made of alumina, zirconia, steatite, copinate, or glass. It will be done. The dimensions of the sensor substrate 1 may be other than those described above, and the material may be ceramics other than those described above or materials other than ceramics.

2 parallel to the long side from the short side of this rectangular sensor board 1.
A book notch 2.2 is formed, so that the sensor substrate 1 becomes fork-shaped and three protrusions 3a, 3b, 3c are formed. The order of the protrusions 3a, 3b, and 3c is from the upstream side of the fluid flow. Among these, the middle protrusion 3b is thinner than the other protrusions 3a and 3c, and a small through hole 4 is bored at a position slightly closer to the proximal end than its tip.

The cutout portion 2.2 is formed at the same time as the sensor substrate 1 is punched and pressed, and then the through hole 4 is formed by laser cutting, drilling, or the like. However, the notch 2.2 may be formed in a separate process from the sensor substrate 1, or conversely, the sensor substrate 1, the notch 2.2, and the through hole 4 may be formed simultaneously by punching press, laser cutting, etc. good.

Furthermore, the inner part of the notch 2.2 is curved, which alleviates stress concentration and prevents cracks and the like. Projections 3a, 3b
, 3c may also be curved.

After firing the sensor substrate 1, as shown in FIG. 2 (1), high melting point glass is formed on the front surface of the protrusion 3a shown by diagonal lines, and on the front and back surfaces of the protrusion 3b near the center from the through hole 4. Printing and baking are performed, and undercoat glass 5 is laminated.

Heat generating film bodies 6a, 6b and a temperature compensation resistor 7, which will be described below, are formed in this shaded area.

Next, as shown in FIG. 2 (2), the central protrusion 3b
The organic platinum paste is printed in a thin or thick film over the entire surface of the amplifier coated glass 5 on the front and back surfaces of the amp coated glass 5, and the organic platinum paste is also printed in a thick film on the undecoated glass 5 on the surface of the protrusion 3a. The paper is printed in a long, thin, inverted and folded state at three points. This printed organic platinum paste is fired to precipitate platinum,
Heat generating film bodies 6a, 6b and temperature compensation resistor 7 are formed.

Then, as shown in FIG. 2(3), silver platinum or silver palladium is printed and fired on the surfaces of the protrusions 3a and 3b and the back surfaces of the protrusions 3b and 3C, which are shown with diagonal lines, to conduct the conductivity to the film body 8. is formed.

The conductive film body 8 is formed on the surface of the sensor substrate 1, extending from both ends of the temperature compensation resistor 7 toward the proximal edge of the protruding portion 3a, and forming pole portions 9a and 9b. The inner conductive film 8 further curves inverted along the notch 2, enters the protrusion 3b, and is connected to the heat generating film 6a. Thereby, the heat generating film body 6a and the temperature compensation resistor 7 are electrically connected.

Furthermore, on the back surface of the sensor substrate 1, two rows of conductive film bodies 8 extend from the tip of the protrusion 3c toward the proximal edge of the protrusion 3C to form a lead-out@pole part 9C19d. The conductive film body 8 further curves inverted along the notch 2,
It enters into the protrusion 3b and is connected to the heat generating film body 6b.

Further, a conductive tWA body 8 is formed from inside the through hole 4 to near the front and back of the through hole 4, and also to the front and back heat generating film bodies 6a and 6b, and both heat generating film bodies 6a and 6b are also electrically connected.

After this, as shown in FIG. 2(4), the heating film bodies 6a, 6
b. Glass is printed and fired on the temperature compensation resistor 7,
Overcoat glass 10 is formed. This overcoat glass 10 includes heating film bodies 6a, 6b, a temperature compensation resistor 7
to protect it from dust.

Next, as shown in FIG. 2(5), ruthenium oxide is printed and fired between the conductive film bodies 8.8 on the back side of the tip of the protrusion 3C, thereby forming the detection resistor 11. This detection resistor 11 is connected to the heat generating WA body 6a by the conductive film body 8...
, 6b, and is used to detect the amount of current flowing through the heat generating film bodies 6a, 6b. The thickness of the detection resistor 11 is preferably several tens of microns, but is not limited to this, and the material may be other than ruthenium oxide.

Finally, as shown in FIG. 2(6), polyimide is printed on the detection resistor 11 and heat treated to form an overcoat polyimide 12.

This overcoat polyimide 12 protects the detection resistor 11 from dust, and preferably has a thickness of 10 microns or less, but is not limited to this, and may be made of a material other than polyimide.

For the sensor substrate 1 manufactured in this way, the above-mentioned extraction of the base end of the sensor substrate 1 is performed at the pole portions 9a, 9b, 9c, 9d.
Metal electrode bins 13 are attached to each of them. As shown in FIG. 3 (1), the attachment part 13a of the base end of the t-pole bin 13 has a "U" shape, and this "U" shape
It has a shape in which one rod-shaped contact part 13b extends outward from the center of the section, and a third
As shown in Figure (2), the proximal edge of the sensor board 1 is inserted and soldered.

After the electrode bins 13 are attached to the sensor board 1, the sensor board 1 is inserted and fixed into a sensor holder 14 as shown in FIG.

This sensor holder 14 has a thick rectangular shape with rounded corners, and long holes 15 are formed in the surfaces of each of the protrusions 3a, 3b, and 3c to allow fluid to flow through the sensor holder 14. It comes into contact with each of the protrusions 3a, 3b, and 3c. The base end of the sensor holder 14 has a thick disk shape,
This disk portion is fixed to a channel wall (not shown) via an O-ring.

The connecting portions 1, 3b, etc. of the electrode bins 13, etc. protrude from the insertion opening 16 of the disk portion of the sensor holder 14, and
Used for connection with external circuits.

In this way, each protrusion 3a, 3b, 3c of the sensor board 1
are not connected to each other and are separated by the cutout 2, so that the temperature compensating resistor 7 provided on the protrusion 3a, the heat generating film bodies 6a and 6b provided on the protrusion 3b, and the heat generating film bodies 6a and 6b provided on the protrusion 3c are connected to each other. The detection resistors 11 are thermally insulated from each other to prevent thermal influences, allowing accurate flow rate measurement.

Further, each element of the detection resistor 11, heat generating film bodies 6a, 6b, and temperature compensation resistor 7 is made of the same material and shape as the sensor substrate 1.
Since they are provided on the protrusions 3a, 3b, and 3C, they can be formed in the same process, such as printing and firing, which improves mass productivity.

In particular, in this embodiment, the detection resistor 11, the heat generating film bodies 6a, 6
(b) Since each element of the temperature compensation resistor 7 is printed and fired in the form of a thick film, it is particularly remarkable that mass production is improved.

FIGS. 5 and 6 show another embodiment, in which the sensor substrate 1 is completely divided into protrusions 3a, 3b, and 3c.

In this case, the electrode bins 13... each have protrusions 3a, 3b,
Two inserts are attached for each 3C, and accordingly there are three insertion openings 16 of the sensor holder 14 into which the sensor substrates 1 are inserted. Fl! The configuration and manufacturing process of Embodiment 1 are the same as those of the embodiment described above.

In this embodiment, each protrusion 3a, 3b, 3 of the sensor board 1
Since C is completely divided and separated, each element of the detection resistor 11, heat generating film bodies 6a, 6b, and temperature compensation resistor 7 can be completely thermally isolated.

The present invention is not limited to the above-described embodiments, and can be modified in various ways without departing from the scope of the present invention.9 For example, the protrusion 3 of the sensor substrate 1 may have a plate shape, a rod shape, a curved shape, or a cylindrical shape. The protrusions 3 may not only be located parallel to each other, but may also extend in different directions, such as at right angles or in opposite directions. (The manufacturing method for each element may also be by vapor deposition, etching techniques, etc. in addition to printing,
The present invention can also be used in thermal sensors other than thermal flow rate sensors, such as thermal flow rate sensors, level sensors, temperature sensors, and other electronic components.

[Effects of the Invention] As described in detail above, according to the present invention, one or more heating elements are provided for each of a plurality of bases that have a protruding shape and whose protruding portions are not connected to each other. Heat from each heating element of each base will not be transmitted to other heating elements via the base, allowing accurate detection, and since each heating element is installed on the same base, each The work of providing each heating element on the base body can be performed in the same pattern, which has the advantage of being suitable for mass production.

[Brief explanation of drawings]

1 to 6 show embodiments of the present invention.
The figures are a front view and a back view of the sensor board 1, FIG. 2 is a diagram showing the manufacturing process of the sensor, and FIG. 3 is a diagram showing the state in which the electrode pins 13 are attached to the sensor board 1.
FIG. 4 is a diagram showing a state in which the sensor holder 14 is attached, and FIGS. 5 and 6 are diagrams showing another embodiment,
FIG. 7 is a diagram showing a conventional example. 1...Sensor board, 3a, 3b, 3C...Protrusion part,
4...Through hole, 5...Undercoat glass,
6a, 6b... Heat generating film body, 7... Temperature compensation resistor, 8
... Conductive film body, 9a, 9b, 9c, 9d=--Takeout electrode part, 10... Overcoat glass, 11... Detection resistor, 12... Overcoat polyimide, 13...
1! Pole pin, 14...sensor holder.

Claims (1)

[Claims] 1. In a sensor for detecting various physical quantities, a plurality of protruding base bodies provided at positions for detecting physical quantities, the protruding portions of which are not connected to each other; On the other hand, a heating element for a sensor characterized by comprising one or more heating elements that generate heat. 2. The heating element for a sensor according to claim 1, wherein the heating element is a resistor other than a sensor part in a circuit for detecting various physical quantities. 3. Claim 1 or 2, wherein the heating element is formed by printing on the substrate in the form of a thin film or a thick film.
Heating element of the sensor described. 4. Claim 1, wherein each of the heating elements is electrically connected to each other or to another circuit by a conductive film printed on the base in the form of a thin or thick film. 3. The heating element of the sensor according to 2 or 3.