JP6603991B2 - Temperature sensor - Google Patents

Description

  The present invention relates to a temperature sensor suitable for measuring the temperature of a heating roller of a copying machine, a printer or the like and having excellent responsiveness.

Generally, a heating sensor used in a copying machine or a printer is provided with a temperature sensor in contact with the heating roller in order to measure its temperature. As such a temperature sensor, for example, in Patent Document 1, a pair of lead frames, a thermal element disposed and connected between the lead frames, and a holding portion formed at an end portion of the pair of lead frames. And a temperature sensor including a lead frame and a thin film sheet provided on one side of the thermal element and brought into contact with a heating roller has been proposed.
In Patent Document 1, a thin film thermistor in which a heat sensitive film is formed on one surface of an insulating substrate such as alumina is employed in addition to a bead thermistor and a chip thermistor as a heat sensitive element.

  Further, as a thermistor using a heat-sensitive film, Patent Document 2 discloses an insulating substrate, an insulating film formed on one surface of the insulating substrate, a pair of comb-shaped electrodes patterned on the insulating film, and comb teeth. A pair of external lead terminals extending from the end of the electrode and formed at one end on the insulating substrate, a heat sensitive film made of a metal oxide patterned on the comb electrode with the insulating film as a base, and a heat sensitive film A thin film thermistor is described that includes an insulating protective film that protects and a glass protective film that covers the insulating protective film excluding the pair of external lead terminal portions.

  In recent years, a temperature sensor in which a thin film thermistor is formed on an insulating film has been developed as a film-type temperature sensor that is excellent in flexibility and can be thinned as a whole. For example, in Patent Document 3, an insulating film, a thin film thermistor portion patterned with a thin film thermistor material on the surface of the insulating film, and a plurality of comb portions on the thin film thermistor portion are formed to face each other. A temperature sensor including a pair of comb electrodes and a pair of pattern electrodes connected to the pair of comb electrodes and patterned on the surface of an insulating film has been proposed.

JP 2000-74752 A JP 2007-11538 A JP 2013-205317 A

The following problems remain in the conventional technology.
That is, the technique described in Patent Document 3 has an advantage of being thin and highly flexible. However, when temperature measurement is performed by bringing an insulating film into contact with an object to be measured, a resin film such as a polyimide film has a relatively high heat collecting property. In some cases, heat is not easily transmitted to the thin film thermistor portion formed on the insulating film.

  The present invention has been made in view of the above-described problems, and provides a temperature sensor that can obtain a high heat collecting property when measuring a temperature by bringing it into contact with an object to be measured, thereby enabling more accurate temperature measurement. With the goal.

The present invention employs the following configuration in order to solve the above problems. That is, the temperature sensor according to the first invention, an insulating film, and thermistors portion formed by the thermistor material disposed on the surface of the insulating film was made form to face each other in the thermistors portion a pair of electrodes, and a pair of pattern electrodes patterned on the connected to a pair of electrode surface of the insulating film, if the insulating film directly below the thermistors portion a back surface of the insulating film And a heat collecting film patterned with a material having high thermal conductivity.

Since this temperature sensor comprises a heat-collecting layer formed pattern with high heat-conductive material than the insulating film directly below the thermistors portion a back surface of the insulating film, measured to Atsumarinetsumaku By bringing the insulating film into contact with an object, it is possible to obtain a higher heat collecting property than when the insulating film is brought into direct contact with the object to be measured, and more accurate temperature measurement is possible.
When the entire back surface of the insulating film is covered with a metal film or when a metal substrate is pasted, the heat transferred from the object to be measured escapes to the entire back surface of the insulating film, resulting in low temperature measurement accuracy and responsiveness. It made. in the present invention, Atsumarinetsumaku that is partially or locally pattern formed on the back surface of the insulating film, to suppress the escape of heat, actively be transferred to the thermistors portion facing And high temperature measurement accuracy and responsiveness can be obtained. In particular, in the present invention, the heat collecting film is used as a contact surface, which is suitable when it is necessary to perform temperature measurement at a pinpoint, such as a small measurement object or measurement location.
Further, since the heat collecting film is partially or locally and is thinner and more flexible than the metal plate, the flexibility of the insulating film is not impaired. Therefore, the heat collection film can be brought into contact along the curved surface of the measurement object, and heat collection can be efficiently performed on the measurement object having various shapes.

A temperature sensor according to a second invention is characterized in that, in the first invention, the heat collecting film is a metal film.
That is, in this temperature sensor, since the heat collecting film is a metal film, a high heat collecting effect is obtained with a higher thermal conductivity than an insulating film such as polyimide.

A temperature sensor according to a third invention is characterized in that, in the first or second invention, the heat collecting film has a Cu thin film on at least a surface thereof.
That is, in this temperature sensor, since the heat collecting film has a Cu thin film on at least the surface, a more accurate temperature measurement can be performed by the Cu thin film having high thermal conductivity.

A temperature sensor according to a fourth invention is the temperature sensor according to any one of the first to third inventions, wherein the thermistor part is a thin film thermistor part formed by patterning the thermistor material on the surface of the insulating film. The electrodes are a pair of comb-shaped electrodes that have a plurality of comb portions on at least one of the upper and lower sides of the thin film thermistor portion and are patterned to face each other.
In the temperature sensor according to a fifth aspect, in the fourth aspect, the outer shape of the heat collecting film is set to be equal to or greater than the outer shape of the thin film thermistor part and equal to or less than the outer shape of the pair of comb electrodes. It is characterized by.
That is, in this temperature sensor, since the outer shape of the heat collecting film is set to be equal to or larger than the outer shape of the thin film thermistor part and equal to or smaller than the outer shape of the pair of comb-shaped electrodes, the heat collected by the heat collecting film is opposed. Since the heat collecting film is not larger than the outer shape of the pair of comb-shaped electrodes, heat spreads more than necessary and does not escape more efficiently. It becomes possible to do. In addition, heat is transferred from the opposing heat collecting film to the comb electrode part directly formed on the surface of the insulating film outside the thin film thermistor part, and this heat is also transmitted to the thin film thermistor part via the comb electrode. High heat collecting property is obtained by being transmitted.

The present invention has the following effects.
That is, according to the temperature sensor according to the present invention, since a back surface of the insulating film includes a heat-collecting film which is patterned with a material having high thermal conductivity than the insulating film directly below the thermistors portion By bringing the heat collecting film into contact with the measurement object, high heat collecting property can be obtained, and more accurate temperature measurement can be performed.
Therefore, according to the temperature sensor of the present invention, flexible surface contact is possible due to the insulating film and the thin heat collecting film, and accurate temperature measurement can be made pinpoint due to high heat collecting properties, such as a copying machine, a printer, etc. This is suitable for the temperature of the heating roller.

It is the top view which shows one Embodiment of the temperature sensor which concerns on this invention, AA sectional view, and a reverse view. In this embodiment, it is the top view and BB sectional drawing which show a thin film thermistor part formation process. In this embodiment, it is a top view which shows an electrode formation process, and CC line sectional drawing.

  Hereinafter, an embodiment of a temperature sensor according to the present invention will be described with reference to FIGS. 1 to 3. Note that in some of the drawings used for the following description, the scale is appropriately changed as necessary to make each part recognizable or easily recognizable.

As shown in FIG. 1, the temperature sensor 1 of the present embodiment includes an insulating film 2, a thin film thermistor section 3 (thermistor section) that is patterned on the surface of the insulating film 2 with a thermistor material, and a thin film thermistor section. A pair of comb-shaped electrodes 4 (electrodes) having a plurality of comb portions 4a on 3 and patterned to face each other, and a pattern formed on the surface of the insulating film 2 connected to the pair of comb-shaped electrodes 4 The pair of pattern electrodes 5, the insulating protective film 6 covering the thin film thermistor portion 3 and the comb-shaped electrode 4, and the back surface of the insulating film 2 directly below the thin film thermistor portion 3 and heat more than the insulating film 2. And a heat collecting film 7 patterned with a material having high conductivity.

The heat collecting film 7 is a metal film, and preferably has a Cu thin film at least on its surface. That is, in the present embodiment, the heat collecting film 7 has a laminated structure of a Cr thin film directly formed on the insulating film 2 and a Cu thin film formed thereon.
Further, the outer shape of the heat collecting film 7 is set to be equal to or larger than the outer shape of the thin film thermistor portion 3 and equal to or smaller than the outer shape of the pair of comb electrodes 4. In the present embodiment, the heat collecting film 7 is formed in a square pattern with the same center as the thin film thermistor portion 3 in plan view, but the size is set to be the same as the outer shape of the pair of comb electrodes 4. Has been.

Note that an insulating protective sheet that covers the thin film thermistor portion 3, the comb electrode 4, and the pattern electrode 5 may be bonded to the surface of the insulating film 2.
Further, the pair of lead frames may be bonded to the surface of the insulating film 2 with an adhesive such as a conductive resin adhesive and connected to the pair of pattern electrodes 5.

  The said insulating film 2 is made into the substantially rectangular shape, for example, is formed in strip | belt shape with the polyimide resin sheet of thickness 7.5-125 micrometers. The insulating film 2 can also be made of PET: polyethylene terephthalate, PEN: polyethylene naphthalate, etc., but for measuring the temperature of the heating roller, a polyimide film is desirable because the maximum use temperature is as high as 230 ° C.

The thin film thermistor portion 3 is disposed on one end side of the insulating film 2 and is formed of a TiAlN thermistor material. In particular, the thin film thermistor portion 3 is a metal represented by the general formula: Ti _x Al _y N _z (0.70 ≦ y / (x + y) ≦ 0.95, 0.4 ≦ z ≦ 0.5, x + y + z = 1). It consists of nitride and its crystal structure is a hexagonal wurtzite single phase.

The pattern electrode 5 and the comb-shaped electrode 4 are formed on the thin film thermistor portion 3 with a thickness of 5 to 100 nm of a Cr or NiCr bonding layer and a noble metal such as Au on the bonding layer with a thickness of 50 to 1000 nm. And an electrode layer formed.
The pair of comb-shaped electrodes 4 has a comb-shaped pattern in which comb portions 4a are arranged alternately and arranged in opposition to each other.

  The comb portion 4a extends along the extending direction of the insulating film 2. That is, when the heat collecting film 7 on the back surface side of the insulating film 2 is pressed against a rotating heating roller to measure temperature, the insulating film 2 is curved with a curvature in the extending direction of the insulating film 2, Bending stress is also applied to the thin film thermistor portion 3 in the same direction. At this time, since the comb portion 4a extends in the same direction, the thin film thermistor portion 3 is reinforced, and generation of cracks can be suppressed.

The pair of pattern electrodes 5 are connected to the comb-shaped electrode 4 at the tip end side, and the base end side is arranged on both sides of the insulating film 2.
The protective film 6 is an insulating resin film or the like, for example, a polyimide film having a thickness of 20 μm is employed.

A method for manufacturing the temperature sensor 1 will be described below with reference to FIGS. 1 to 3.
The manufacturing method of the temperature sensor 1 of the present embodiment includes a thin film thermistor portion forming step of patterning the thin film thermistor portion 3 on the surface of the insulating film 2 and a pair of comb electrodes 4 facing each other on the thin film thermistor portion 3. An electrode forming step of forming a pair of pattern electrodes 5 on the surface of the insulating film 2, a heat collecting film forming step of forming the heat collecting film 7 on the back surface of the insulating film 2, A protective film forming step for forming a protective film 6 on the surface.

As a more specific example of the manufacturing method, Ti _x Al _y is used in a reactive sputtering method in a nitrogen-containing atmosphere using a Ti—Al alloy sputtering target on a polyimide film insulating film 2 having a thickness of 50 μm. A thermistor film of N _z (x = 9, y = 43, z = 48) is formed with a film thickness of 200 nm. The sputtering conditions at that time were an ultimate vacuum of 5 × 10 ⁻⁶ Pa, a sputtering gas pressure of 0.4 Pa, a target input power (output) of 200 W, and a nitrogen gas fraction of 20 in a mixed gas atmosphere of Ar gas + nitrogen gas. %.

A resist solution is applied onto the deposited thermistor film with a bar coater, pre-baked at 110 ° C. for 1 minute and 30 seconds, exposed to light with an exposure device, and unnecessary portions are removed with a developer, and further at 150 ° C. for 5 minutes. Patterning is performed by post-baking. Thereafter, the unnecessary Ti _x Al _y N _z thermistor film is wet-etched with a commercially available Ti etchant, and the thin film thermistor portion 3 having a desired shape is formed by resist stripping as shown in FIG.

Next, a 20 nm-thick Cr film bonding layer is formed on the thin film thermistor portion 3 and the insulating film 2 by sputtering. Further, an Au film electrode layer is formed to a thickness of 200 nm on this bonding layer by sputtering.
Next, after applying a resist solution on the electrode layer formed with a bar coater, pre-baking is performed at 110 ° C. for 1 minute 30 seconds, and after exposure with an exposure apparatus, unnecessary portions are removed with a developing solution, Patterning is performed by post-baking for 5 minutes. Thereafter, unnecessary electrode portions are wet-etched in the order of commercially available Au etchant and Cr etchant, and as shown in FIG. 2, desired comb electrodes 4 and pattern electrodes 5 are formed by resist stripping.

  Next, a Cr film having a thickness of 20 nm is formed on the back surface of the insulating film 2 by sputtering, and then a Cu film having a thickness of 50 nm is formed by sputtering. Further, a resist solution is applied onto the formed Cu film, pre-baked, and after exposure with an exposure apparatus, unnecessary portions are removed with a developer to perform patterning. Thereafter, unnecessary portions are wet-etched in the order of commercially available Cu etchant and Cr etchant, and a desired heat collecting film 7 is formed by resist stripping as shown in FIG.

  Furthermore, a polyimide varnish is applied to the surface of the insulating film 2 by a printing method and cured at 180 ° C. for 30 minutes to form a polyimide protective film 6 having a thickness of 20 μm as shown in FIG. The sensor 1 is manufactured.

Thereafter, a polyimide film with an adhesive may be attached to the surface of the insulating film 2 as a protective sheet.
In the case of manufacturing a plurality of the temperature sensors 1 simultaneously, the insulating film 2 for large sheet into a plurality of thin film thermistor portion 3, comb-shaped electrode 4, the pattern electrode 5, hot film 7 and the protective film 6 focusing as described above After the formation, the temperature sensor 1 is cut from the large sheet.

  As described above, in the temperature sensor 1 of the present embodiment, the heat collecting film 7 patterned with a material having higher thermal conductivity than the insulating film 2 is provided on the back surface of the insulating film 2 and immediately below the thin film thermistor portion 3. Therefore, by bringing the heat collecting film 7 into contact with the object to be measured, it is possible to obtain a higher heat collecting property than when the insulating film 2 is brought into direct contact with the object to be measured, and more accurate temperature measurement is possible. It becomes possible.

  In the present embodiment, the heat collecting film 7 is partially or locally patterned on the back surface of the insulating film 2, thereby suppressing heat escape and actively transferring heat to the opposing thin film thermistor portions 3. Therefore, high temperature measurement accuracy and responsiveness can be obtained. In particular, in the present embodiment, the heat collecting film 7 is used as a contact surface, which is suitable when it is necessary to perform temperature measurement at a pinpoint, such as a small measurement object or measurement location.

  Further, since the heat collecting film 7 is partial or local and is thinner and more flexible than the metal plate, the flexibility of the insulating film 2 is not impaired. Therefore, the heat collecting film 7 can be brought into contact along the curved surface of the measurement object such as a heating roller, and it is possible to efficiently collect heat with respect to various shapes of the measurement object.

Furthermore, since the heat collecting film 7 is a metal film, a high heat collecting effect can be obtained with a higher thermal conductivity than the resin film 2 such as polyimide. In particular, since the heat collecting film 7 has a Cu thin film at least on the surface, a more accurate temperature measurement can be performed by the Cu thin film having high thermal conductivity.
Further, since the outer shape of the heat collecting film 7 is set to be equal to or larger than the outer shape of the thin film thermistor portion 3 and equal to or smaller than the outer shape of the pair of comb electrodes 4, the heat collected by the heat collecting film 7 is opposed. Since the heat collecting film 7 is not of a size exceeding the outer shape of the pair of comb-shaped electrodes 4, heat is not spread more than necessary and escapes efficiently. It is possible to collect heat. Note that heat is also transmitted from the opposed heat collecting film 7 to the portion of the comb electrode 4 formed directly on the surface of the insulating film 2 outside the thin film thermistor portion 3, and this heat is transmitted through the comb electrode 4. By being transmitted to the thin film thermistor part 3, high heat collecting property can be obtained.

  The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Temperature sensor, 2 ... Insulating film, 3 ... Thin film thermistor part (thermistor part) , 4 ... Comb-shaped electrode (electrode) , 4a ... Comb part , 5 ... Pattern electrode, 6 ... Protective film, 7 ... Heat collecting film

Claims (4)

An insulating film;
A thermistor portion formed of a thermistor material provided on the surface of the insulating film;
A pair of electrodes formed opposite to each other on the thermistor portion;
A pair of pattern electrodes connected to the pair of electrodes and patterned on the surface of the insulating film; and
A heat collecting film patterned on the back surface of the insulating film and directly under the thermistor with a material having higher thermal conductivity than the insulating film;
The thermistor part is a thin film thermistor part patterned with the thermistor material on the surface of the insulating film,
The pair of electrodes is a pair of comb-shaped electrodes having a plurality of comb portions on at least one of the upper and lower sides of the thin film thermistor portion and patterned to face each other,
The comb electrode is formed up to the periphery of the thin film thermistor part,
The comb in which the heat collecting film is partially or locally patterned inside the outer peripheral edge of the insulating film and directly formed on the surface of the insulating film outside the thin film thermistor portion. A temperature sensor characterized by facing the mold electrode portion . The temperature sensor according to claim 1,
The temperature sensor, wherein the heat collecting film is a metal film. The temperature sensor according to claim 1 or 2,
The temperature sensor, wherein the heat collecting film has a Cu thin film at least on its surface. The temperature sensor according to any one of claims 1 to 3,
The temperature sensor, wherein an outer shape of the heat collecting film is set to be larger than an outer shape of the thin film thermistor portion and equal to or less than an outer shape of the pair of comb electrodes.

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