JP2010237156A - Temperature sensor for measurement - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve workability in manufacturing of a temperature sensor by overcoming the problem based on the shape of a thermistor. <P>SOLUTION: The temperature sensor for measurement disclosed is obtained by fusion-bonding and integrating a glass-sealed thermistor element, which is composed of a thermistor element assembly with a thermistor chip 1 fusion-sealed by a fusion-sealed glass 5 and a thermistor lead 2, to a sheet glass 6 with a melting point higher than that of the fusion-sealed glass 5. One side of the sheet glass 6 has a plane wider than the glass-sealed thermistor element. The temperature sensor for measurement is charged into a high-temperature furnace as being sealed in glass, so that the thermistor element is welded into the sheet glass while being protected from an oxidizing atmosphere by the fusion-sealed glass. Accordingly, the temperature sensor for measurement with the plane on one side is manufactured which holds strength while maintaining electrical insulation. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a temperature sensor for measurement using a thermistor.

  As the form of the thermistor, a bead type, a pellet type, a diode type, a chip resistor type and the like are generally known. The structures and manufacturing methods of these various thermistors are described in Patent Document 1, Patent Document 2, Patent Document 3, and the like.

The thermistor may be used as a thermistor element or element, and may be used alone or mounted on a printed circuit board or the like without any additional processing.
However, thermistor element is subject to additional processing for various reasons, such as when the object of temperature detection is the surface temperature of the object, the thermistor element alone cannot be used due to insufficient strength, or when it is easy to mount. In many cases, it is used in the form of a specific temperature sensor. In the following, the thermistor subjected to such additional processing is called a temperature sensor and is distinguished from a simple thermistor element.

  Hereinafter, the prior art about the example of an additional process is demonstrated. When a chip thermistor is used, the shape is originally intended for mounting on a printed circuit board, so that the lead wire does not come out of the thermistor, and additional processing for drawing out the lead wire from the thermistor is required. This example is described in Patent Document 4 described later.

Further, as another example of the additional processing, there is one described in Patent Document 5 as one that is used for detecting an atmosphere to be detected (for example, air temperature, water temperature, oil temperature) by a temperature sensor of a metal protective tube, for example . Further, Patent Document 6 describes a temperature sensor by additional processing of a thermistor element that measures the surface temperature of a rice cooker used in a rice cooker.
Further, as temperature sensors for controlling the surface temperature of a fixing device used in a copying machine or a printer, there are those described in Patent Document 7, Patent Document 8, and Patent Document 9.
Furthermore, there exist some which were described in patent document 10 and patent document 11 as an example of the additional process of the thermistor element used for the temperature detection of a cooking pan bottom with a gas stove.

In Patent Document 1, an electrode formed by baking a heat-resistant conductive paint is provided on both surfaces of a main body obtained by sintering a powder raw material into a plate shape, and a base portion of a metal lead wire that can be sealed to glass is provided with a heat-resistant conductive material. A thermistor for measurement is disclosed in which the main body and the base of the electrode and the lead wire are embedded in glass or coated with glass by connecting to the electrode with paint.
In addition, after molding and sintering the raw material powder, it can be processed into a flat plate shape to form a main body, and a heat-resistant conductive paint can be applied to both sides of the main body to cover the electrodes and be sealed to glass A conductive paint in which a metal lead wire is bonded to the electrode with a heat-resistant conductive paint, the main body is inserted into the glass, and the glass is heated and melted to embed the main body in the glass and at the same time the lead wire is bonded. A method for manufacturing a thermistor for measurement, which is characterized in that the baking is performed, is disclosed.

  In Patent Document 2, the lead wire is inserted through a ceramic pipe having a thermal expansion coefficient substantially equal to that of a thermistor element, a glass sealing body for sealing the thermistor element, and a lead wire connected to the thermistor element. A thermistor is disclosed in which the thermistor element is fixed to the end of the ceramic pipe by the glass sealing body.

  In Patent Document 3, a ceramic substrate, an insulating film provided on one main surface of the ceramic substrate, a first heat sensitive film provided on the insulating film, and the first heat sensitive film are provided. A pair of electrode films provided with connection pads on one main surface of the ceramic substrate, and at least provided on the first electrode film so as to sandwich a part of the pair of electrode films. A thin film thermistor comprising a second heat sensitive film thicker than the first heat sensitive film is disclosed.

  Moreover, in patent document 4, the thin film sensor chip which consists of a heat sensitive film | membrane and a pair of electrode film which were formed on one surface of an insulated substrate, and the leader line electrically connected to the electrode film of this thin film sensor chip, In the temperature sensor constituted by the above, an insertion groove is provided in a portion adjacent to the electrode film of the insulating substrate, a lead wire is inserted into the insertion groove, and the electrode film and the lead wire are electrically connected and fixed by a bonding material. Later, by covering the entire surface of the insulating substrate on the heat-sensitive film side with a protective film, a method for reliably connecting the electrode surface and the lead wire is provided, and an object is to provide a temperature sensor with excellent connection strength. A thermistor temperature sensor is disclosed.

  In Patent Document 5, a thermistor is provided in which a thermistor is embedded in a glass body, two leads are drawn through the glass body and the ceramic body, and two holes are provided around the lead portion of the ceramic body lead. On the other hand, cover each lead with an insulation protection tube, insert this insulation tube until the tip reaches the inside of the hole, cover each insulation protection tube with a heat-resistant protection tube, and insert a cylindrical body that fits with the ceramic body. Filled with a filler made of a heat-resistant inorganic adhesive in advance into a cylindrical body of a metal protective tube provided with a flange having a screw hole at the end on the opening side, inserted a thermistor element, and cured the filler. By fixing the base of the glass body, ceramic body and heat-resistant protective tube in the metal protective tube, a thermistor temperature sensor with a built-in metal protective tube is obtained. Te, while reducing the number of steps of and use materials and assembly operations simplicity structure, facilitated the mounting operation, a thermistor temperature sensor is disclosed.

  Further, in Patent Document 6, a thermistor temperature measuring unit having a hermetic structure in which a thermistor element is closely attached to the inner surface of a metal cap, and the thermistor temperature measuring unit are supported so as to be movable in a certain range up and down, and a thermistor is supported by a spring. It has an outer case that always keeps the temperature measuring part pushed upward, and a reed switch and a magnet fixed to the thermistor temperature measuring part and the outer case, respectively. A thermistor temperature sensor for an automatic cooker, such as an electric rice cooker, configured to perform an operation for detecting the state and to measure the temperature of the inner pan by the thermistor temperature measuring unit contacting the bottom of the inner pan. Thermistor temperature for cookers that has a quick response of the hot section, no deterioration of characteristics even in harsh usage environments, and can reduce the number of man-hours for assembling the rice cooker body Providing capacitors, cooker thermistor temperature sensor is disclosed.

  Further, in Patent Document 7, a thermistor is fixed to the tip of one surface of an elongated metal plate whose base is supported by a holder made of an insulator-forming body, and the two lead wires of the thermistor are connected to the surface of the elongated metal plate. Is connected to two external output lines provided on the opposite side of the elongated metal plate of the holder, and the surface opposite to the thermistor fixing surface of the elongated metal plate is smoothed and heat-sensitive. A temperature sensor is disclosed in which the thermal response and durability are improved by forming the portion so as not to damage the temperature-measured body.

  Moreover, in patent document 8, the shorter one of two heat resistant sheets is piled up inside the sensor part which attached the cushion material piece to the upper surface of the support stand, and fixed the thermistor element through the heat conductive thin film. Fix the end part that is bonded to the lower surface of the support base, cover the cushion material piece and the thermistor element, wrap it, fix the end of the winding to the lower surface of the support base, and the two perforations at the beginning of the heat-resistant sheet The perforation at the end of winding coincides with the other corner of the lower surface of the support base, and the inner heat-resistant sheet covers the thermistor element and the heat conductor, A thermistor element is provided by providing a temperature sensor so that the winding end is provided with a protective film portion that does not reach the perforation, and the winding direction is held with respect to the rotating body perpendicular to the rotating shaft of the rotating body. Used In the surface-contact type temperature sensor, with improved thermal response, the temperature sensor is disclosed.

  Moreover, in patent document 9, a holding body is formed in the terminal part side of a pair of elongate metal plate part extended from a pair of terminal part which connects an external leader line, and the front-end | tip part of a pair of elongate metal plate part In addition, a recess having a thin plate thickness is formed, and the planar heat-sensitive part of the heat-sensitive element is stretched over the recess so that it faces the body to be detected, and the lead part of the heat-sensitive element is formed into a pair of elongated metal plate parts. It is a temperature sensor that is electrically connected and the thermal element of the thermal element is covered with an insulating sheet, stable temperature detection, excellent thermal response, and excellent mechanical strength of the thermal element mounting part A temperature sensor is disclosed that provides a durable temperature sensor.

  Moreover, in patent document 10, a fixing metal fitting is welded to the inner surface side of the heat collection metal member which contact | abuts elastically with the bottom of a cooking utensil. The fixing bracket is in contact with the inner surface of the heat collecting metal member, a storage part that is integral with the contact plate part and bulges out in a U shape, and swells in a U shape with a slit from the storage part. It forms from the lead wire fixing | fixed part which can be crushed. The storage portion is filled with a filler for adjusting the thermal response in the storage portion, and then a thermistor fixed to the tip of the lead wire is inserted. A thermistor mounting device for cooking appliances is disclosed in which the lead wire fixing portion is crushed and the lead wires are fixed to improve the mounting durability of a thermistor for measuring the temperature of a cooking appliance such as a pan.

  Further, in Patent Document 11, a washer is fixed to the lower end of the pipe, a ridge is fixed to the upper end of the pipe, and a cylinder is provided on the outer periphery of the ridge so as to be movable up and down. It is narrowed down into a small-diameter cylinder, and the upper end is folded horizontally outward to form a bent part, and the bent part is covered with a cap body, and the outer peripheral edge of the cap body with respect to the bent part In addition, there is disclosed a temperature detection tool for cooking utensils that can be bent and fixed without gaps to constitute a temperature detection tool for cooking utensils so as to obtain a thermistor that is easy to mount and has good heat receiving sensitivity.

JP-A-49-004149 JP-A-57-187630 Japanese Patent Laid-Open No. 06-061012 JP 2003-247897 A No. 3035834 (No. 08-010034) Japanese Utility Model Publication No. 05-094735 JP 2000-019026 A JP 2002-156292 A JP 2000-074752 A Japanese Patent Laid-Open No. 05-123248 JP 2002-243558 A

When the thermistor element is manufactured, its shape is made common and mass production is possible. However, when a temperature sensor is manufactured by performing additional processing, since the shape is various, it usually requires labor and time for processing.
For example, in the case of a temperature sensor using a glass-sealed thermistor element, the thermistor element is sealed with glass to increase the fixing strength between the thermistor chip and the lead wire, and thermistor chip that is an oxide. Is shielded from the outside world to protect it from oxidation / reduction reactions caused by outside air.

In this case, in the glass sealing process, the outer shape of the thermistor element is always rounded due to the surface tension of the molten glass. Therefore, troublesome work is required for rounding when performing additional processing.
In order to overcome the difficulty of this work, a device as described in each of the aforementioned patent documents is required. In particular, in the case of a temperature sensor that detects temperature on a flat surface, such a problem becomes significant.

That is, when transferring heat received on a flat surface made of metal, resin, rubber, etc. to a round thermistor element, fill the gap between the flat resin, rubber, etc. and the surface of the round thermistor element. At the same time, the heat responsiveness decreases due to the increase in heat capacity.
Furthermore, since it is difficult to manage the amount of material for filling the gap, there is a variation in the thermal response based on this, and there is an adverse effect on the characteristics such as loss of uniformity in the performance of the temperature sensor. Become.

  In addition, when using a chip thermistor, the chip thermistor is originally intended for mounting on a printed circuit board, so the lead wire is not drawn from the thermistor element, so the lead wire is drawn from the thermistor by additional processing. A process is required, and labor and cost increase.

  The present invention has been made in view of such circumstances, and an object of the present invention is to solve the problems of the conventional temperature sensor and to improve the workability of the temperature sensor.

  In order to solve the above problems, the present invention relates to a temperature sensor for measurement, in which a thermistor in which a thermistor body and a lead wire are sealed with a glass material and a sheet glass having a melting point higher than that of the glass material are fusion-bonded. The area of the sheet glass is equal to or larger than the fusion area of the sheet glass and the glass material that seals the thermistor, and the sheet material of the sheet glass, The surface opposite to the fused surface is flat.

  The present invention also relates to a temperature sensor for measurement, wherein a thermistor in which a thermistor body and a lead wire are sealed with a glass material and a thin plate-like ceramic having a melting point higher than that of the glass material are fused and joined. The area of the ceramic sheet is equal to or larger than the fusion area of the glass material for sealing the thermistor and the thin plate ceramic, and the fusion surface of the thin sheet ceramic to the glass material; The opposite surface has a flat surface.

  According to the present invention, it is possible to solve the problems based on the shape of the thermistor element and to improve the workability at the time of manufacturing the temperature sensor.

It is a figure which shows the sealing process of a chip | tip glass sealing thermistor element. It is a figure which shows the assembly process of the temperature sensor for a measurement using a chip | tip glass sealing thermistor element. It is a figure which shows the sealing process of a diode type glass sealing thermistor element. It is a figure which shows the assembly process of the temperature sensor for a measurement using a diode type glass sealing thermistor element. It is a figure which shows the detailed structure of the temperature sensor described in the prior art example (patent document 7). It is a figure which shows the structure of the temperature sensor which replaced the thermistor element of the prior art example with the thermistor element of this invention. It is a figure which compares and shows the thermal responsiveness of the temperature sensor shown in FIG. 5, and the temperature sensor shown in FIG.

  1 and 2 show a first embodiment of the present invention, and exemplify a case of a typical glass-sealed thermistor element using a chip-type thermistor. Hereinafter, a manufacturing method of the temperature sensor for measurement in this case will be described in detail.

  First, as shown in FIG. 1 (a), a thermistor lead wire 2 is temporarily bonded to a thermistor chip 1 having electrodes on both sides with a heat-resistant adhesive 3, and these are disposed so as to penetrate the inside of the glass tube 4. In the state, the glass tube 4 is heated and melted to form a sealed glass 5 having a form as shown in FIG.

Next, as shown in FIG. 2A, the glass-sealed thermistor element on which the fused glass 5 is formed is placed on the thin plate glass 6.
The thin glass 6 has a melting point of about 750 ° C. and a melting point of about 100 ° C. higher than that of the sealed glass 5 in which the thermistor chip 1 is sealed. The thin glass 6 is flat and has a width of 1 mm × 1 mm and a thickness of about 0.1 mm. The thermistor chip 1 has a diameter of about 0.1 mm.

  In the state shown in FIG. 2 (a), when the glass tube 4 is charged at a temperature (about 700 ° C.) and charged in a high temperature furnace (not shown), the glass sheet 6 is not melted and remains in a plate shape. Only the fused glass 5 melts and flows, and as shown in FIG. 2 (b), a high-temperature furnace is formed in a state where the glass sheet 7 has a shape that wets the glass sheet 6 and adheres to the glass sheet 6. Come out from.

Thus, since the thermistor chip 1 is inserted into the high temperature furnace in a glass-sealed state, the thermistor chip 1 is welded to the thin glass 6 while being protected by the sealed glass 5 from the oxidizing atmosphere, so that electrical insulation is achieved. A temperature sensor with a lead wire having a flat surface on one side and maintaining the strength while being maintained is obtained.
Therefore, according to this manufacturing method, the shape and size (volume) of the measurement temperature sensor are quantified, and the volume is increased by the amount of the thin glass sheet 6 but the measurement temperature sensor having a constant total volume is mass-produced. Is possible.

In the temperature sensor of the present invention, the direction in which the thermistor lead wire 2 is pulled out is not limited to the example of FIG. 2, and may be perpendicular to the thin glass plate 6 or with respect to the thin glass plate 6. Can be pulled out on both sides.
The size of the thin glass 6 is not appropriate to be widened or narrowed indefinitely, and it is necessary to select an appropriate size according to the temperature detection target.

  3 and 4 show a second embodiment of the present invention and exemplify a case where a diode type thermistor is used. Hereinafter, a manufacturing method of the temperature sensor for measurement in this case will be described.

First, as shown in FIG. 3 (a), an assembling operation is performed on the glass cylinder 11 with the thermistor chip 12 at the center and the slug lead 13 being inserted from both ends. Note that the slag lead 13 is a lead wire having the same structure as that of the glass-encapsulated diode, and as shown in the drawing, a thick jumet wire 13A entering the glass cylinder 11 and a lead wire portion drawn to the outside are brought into contact with each other. It is formed by welding.
Thereafter, as shown in FIG. 3 (b), the glass glass 11 is melted by being charged into a high temperature furnace (not shown) in an assembled state, thereby forming a sealed glass.

Next, as shown in FIG. 4A, the glass sealed thermistor element on which the fused glass 14 is formed is placed on the thin glass plate 15.
The thin glass plate 15 has a melting point of about 750 ° C. and a melting point of about 100 ° C. higher than that of the sealed glass 14 in which the thermistor chip 12 is sealed.

  Next, in the state shown in FIG. 4 (a), when the glass cylinder 11 is charged at a temperature (about 700 ° C.) and charged into a high temperature furnace (not shown), the thin glass 15 is not melted and is plate-shaped. 4, only the fused glass 14 melts and flows, and as shown in FIG. 4 (b), it becomes a flowable glass body 16 that wets the thin glass 15, and adheres to the thin glass 15. Come out of the furnace.

In this way, the sealed glass 14 is formed to fix the thermistor chip 12 and the slag lead 13 and is inserted into the high temperature furnace while being sealed with glass, so that it is protected from the oxidizing atmosphere by the sealed glass 14. In this state, it is welded to the thin glass plate 15 to provide a temperature sensor with a lead wire having a flat surface on one side and maintaining strength while maintaining electrical insulation.
Therefore, according to this manufacturing method, the shape and size (volume) of the temperature sensor for measurement are quantified, and the volume increases by the amount of the thin glass plate 15, but the temperature sensor for measurement having a constant total volume is mass-produced. Is possible.

  In the first embodiment and the second embodiment of the present invention, the thin glass 15 may be replaced with a thin ceramic.

Hereinafter, the performance (effect) of the temperature sensor for measurement according to the present invention will be described by taking the case of the first embodiment as an example in comparison with the conventional example.
FIG. 5 illustrates the structure of the temperature sensor described in Patent Document 7, and illustrates the case where it is applied to an image forming apparatus such as a copier or a printer. In the figure, (a) is a top view showing a manner of attaching a temperature sensor to a fixing roller (not shown) of the image forming apparatus, (b) is a side view of the same, and 21 shows a temperature sensor. The base portion 24 is fixed to the tip of the spring portion 23 fixed by the fixed support portion 22.
(c) shows the detailed structure of the temperature sensor 1 and shows an enlarged portion A, 31 is a thermistor, 32 is an adhesive, 33 is a leaf spring constituting the spring portion 23, and 34 is It is a protective tube for the lead wire of the thermistor 31.

FIG. 6 shows a configuration of a temperature sensor in which the thermistor element of the conventional example shown in FIG. 5 is replaced with the thermistor element of the present invention, and is a top view shown in (a) and shown in (b). The side view is almost the same, but the detailed structure of the temperature sensor shown in (c) is different.
In FIG. 6C, 41 is a thermistor, 42 is an adhesive, 43 is a leaf spring, 44 is a protective tube, and 45 is a thin glass sheet.

  Thus, the case of FIG. 6 is different from that of the prior art shown in FIG. 5 in that the thermistor 41 is held on the thin glass plate 45 bonded on the leaf spring 43. .

  FIG. 7 explains the superiority in the case of the present invention as compared with the case of the prior art. In the case of the present invention, the response time until the same detected temperature ratio (63.2%) is reached. It is shown that τ has become significantly shorter.

  The temperature sensor for measurement according to the present invention is suitable for use as a temperature sensor for measuring the surface temperature of a rotating body such as a heating roller used in a fixing device of a copying machine or a printer.

DESCRIPTION OF SYMBOLS 1 Thermistor chip 2 Thermistor lead wire 3 Heat resistant adhesive 4 Glass tube 5 Sealed glass 6 Thin plate glass 7 Fluid glass body 11 Glass cylinder 12 Thermistor chip 13 Slag lead 14 Sealed glass 15 Sheet glass 16 Fluid glass body

Claims (2)

  A thermistor in which a thermistor body and a lead wire are sealed with a glass material and a thin glass having a melting point higher than that of the glass material are fusion-bonded, and the area of the thin glass seals the thermistor. It is equal to or larger than the fusion area between the glass material and the thin glass, and the surface of the thin glass opposite to the fusion surface with the glass material has a flat surface. Temperature sensor for measurement.   A thermistor in which the thermistor body and the lead wire are sealed with a glass material and a thin plate-like ceramic having a melting point higher than that of the glass material are fusion-bonded, and the area of the thin plate-like ceramic seals the thermistor. It is equal to or larger than the fusion area between the glass material and the thin plate ceramic, and the surface of the thin plate ceramic opposite to the fusion surface with the glass material has a flat surface. Temperature sensor for measurement.

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