JP2018036283A - Noncontact temperature sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a noncontact temperature sensor that can suppress heat loss, has high precision and superior responsiveness, and allows for recovery of the original condition even if paper jams.SOLUTION: The noncontact temperature sensor is provided that comprises: an insulating film 2; a thermistor part 3 in a surface of the insulating film; a pair of electrodes on the thermistor part; a pair of pad electrodes 5 in the surface of the insulating film; a pair of wiring parts 6; and a pair of lead frames 7 bonded to the pair of pad electrodes. The thermistor part is provided in a thermistor formation region 2a of the insulating film, the pad electrodes are formed in an electrode formation region 2b arranged on a proximal end side of the insulating film, and tip sides of the pair of lead frames are arranged surrounding the thermistor formation region without contacting. The pair of lead frames are elastic, and the thermistor formation region projects into a hollow of the region surrounded with the tip sides of the pair of lead frames without contacting the tip sides of the pair of lead frames.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a non-contact temperature sensor suitable for measuring the temperature of a heating roller such as a copying machine or a printer.

In general, there is a heating roller (fixing roller) used in a copying machine or a printer in which a temperature sensor is installed in a non-contact state in order to measure the temperature. As such a non-contact temperature sensor, for example, in Patent Document 1, a flexible printed circuit board in which a conductor pattern is formed on the surface of a resin film and a temperature sensitive element is mounted on the conductive pattern, A non-contact temperature sensor including a housing fixed at a peripheral portion has been proposed.
Patent Document 2 describes a non-contact temperature sensor in which a thermistor element glass-sealed is fixed to the back surface of an infrared transparent film. In this non-contact temperature sensor, the end or peripheral edge of the infrared transmitting film is fixed to a base having a fixing flange. The thermistor elements are electrically connected via lead wires.

JP 2010-43930 A JP 2004-205417 A

The following problems remain in the conventional technology.
That is, in the conventional technology, since the flexible printed circuit board or film on which the temperature sensitive element is mounted is fixed to the casing or the base at the peripheral edge or end thereof, the heat generated by receiving infrared rays passes through the film. There is a problem that the temperature detection accuracy is lowered due to escape to the surrounding casing and base. In addition, there is a problem that the thermal capacity of the temperature sensing element is large and the thermal conductance due to the wiring is large, resulting in poor responsiveness.
In addition, since the flexible printed circuit board and film are fixed to the housing and base at the peripheral edge and edge, paper is jammed between the roller and sensor when measuring the temperature of the heating roller of a copying machine or the like. In such a case, there is a problem that the casing and the base are bent or broken. For this reason, after removing the paper, the distance between the roller and the sensor changes, and the original state cannot be recovered. Further, since there is such a problem of breakage, there has conventionally been a problem that the sensor is disposed away from the roller to a distance that does not hinder the detection accuracy.

  The present invention has been made in view of the above problems, and provides a non-contact temperature sensor that can suppress heat escape, is highly accurate and has excellent responsiveness, and can recover the original state even when a paper jam occurs. The purpose is to do.

  The present invention employs the following configuration in order to solve the above problems. That is, the non-contact temperature sensor according to the first invention includes an insulating film, a thermistor portion provided on the surface of the insulating film, a pair of pad electrodes patterned on the surface of the insulating film, A pair of lead frames bonded to the pair of pad electrodes on the surface side of the insulating film, and the thermistor portion is provided in a thermistor forming region disposed on the tip side of the insulating film, and the pad electrode Is formed in an electrode forming region disposed on the base end side of the insulating film, and the distal end sides of the pair of lead frames are disposed so as to surround the thermistor forming region in a non-contact manner, and the pair of lead frames are The thermistor forming region is hollow in a region surrounded by the tip end side of the pair of lead frames. And wherein the projecting without contacting the side.

  In this non-contact temperature sensor, the tip end sides of the pair of lead frames are arranged so as to surround the thermistor forming region in a non-contact manner, the pair of lead frames have elasticity, and the thermistor forming region is formed of the pair of lead frames. The thermistor part is mechanically protected by the surrounding lead frame and is not in contact with the surrounding lead frame because it protrudes into the hollow area surrounded by the leading end side without contacting the tip side of the pair of lead frames. Therefore, it is difficult for heat to escape to the lead frame, and high responsiveness and high detection accuracy can be obtained. The thermistor forming region protrudes in a hollow and non-contact manner, and can be set to a small area by not extending to the lead frame, and the sensor can be miniaturized. In addition, when measuring the roller of a copier, etc., even if the distance from the roller changes due to a paper jam, the sensor position will return to its original state due to the spring nature (elasticity) of the lead frame when the paper is removed. Can be recovered.

A non-contact temperature sensor according to a second invention is the non-contact temperature sensor according to the first invention, wherein the base end side is bonded to the back side of the electrode forming region of the insulating film, and the tip end side surrounds the thermistor forming region in a non-contact manner. A pair of back side frames arranged in a.
That is, this non-contact temperature sensor includes a pair of back side frames whose base end side is bonded to the back side of the electrode formation region of the insulating film and whose front end side is disposed so as to surround the thermistor formation region in a non-contact manner. Therefore, the thermistor forming region is mechanically protected not only by the front-side lead frame but also by the back-side frame, and is reinforced with higher rigidity. In addition, the electrode forming region can be supported by being sandwiched between the lead frame and the back frame, and the bonding strength between the lead frame and the pad electrode can be maintained to improve the reliability.

A non-contact temperature sensor according to a third invention is characterized in that, in the first or second invention, the non-contact temperature sensor includes an insulating protective film provided so as to cover the back side of the thermistor formation region in a non-contact manner. To do.
That is, this non-contact temperature sensor has an insulating protective film provided so as to cover the back side of the thermistor formation region in a non-contact manner, so that the protective film shields radiant heat on the back side, The influence and the interference of heat from other than the measurement object can be suppressed.

The non-contact temperature sensor according to the present invention includes a pair of electrodes formed opposite to each other on the thermistor portion and one end connected to the pair of electrodes in any one of the first to third aspects. And a pair of wiring portions connected at the other end to the pair of pad electrodes, wherein the wiring portion is a thin film having a thickness of 100 to 300 nm and is patterned on the surface of the insulating film. Preferably there is.
That is, in this non-contact temperature sensor, since the wiring part is a pattern wiring part which is a thin film having a film thickness of 100 to 300 nm and is patterned on the surface of the insulating film, it is used as a wiring on a normal printed circuit board or the like. Compared to a metal foil having a thickness of about 100 μm, the thermal conductance is significantly reduced by making the film thin at the nano level, and higher response can be obtained. When the film thickness is less than 100 nm, the insulating film may be broken when bent, and when the film thickness exceeds 300 nm, the thermal conductance becomes large as in the case of conventional metal foil wiring. Therefore, it is preferable to set the film thickness within the above range.

Furthermore, in the non-contact temperature sensor according to the present invention, the insulating film has a wiring formation region in which the pattern wiring portion is arranged between the thermistor formation region and the electrode formation region, and the wiring formation The region is preferably formed narrower than the thermistor formation region and the electrode formation region.
That is, in this non-contact temperature sensor, since the wiring formation region is formed to be narrower than the thermistor formation region and the electrode formation region, it is difficult for heat to escape through the wiring formation region, and higher responsiveness is obtained. be able to.

The present invention has the following effects.
That is, according to the non-contact temperature sensor according to the present invention, the tip ends of the pair of lead frames are arranged so as to surround the thermistor forming region in a non-contact manner, and the pair of lead frames have elasticity, and the thermistor forming region However, since it protrudes in the state surrounded by the tip side of the pair of lead frames without contacting the tip side of the pair of lead frames, the thermistor part is mechanically protected by the surrounding lead frame, It is difficult for heat to escape to the lead frame, high responsiveness and high detection accuracy can be obtained, and furthermore, high responsiveness can be obtained because the heat capacity is small. Further, when a copying machine roller or the like is a measurement target, the original shape can be recovered by the spring property of the lead frame even if the distance from the roller changes due to a paper jam. Therefore, it can be installed closer to the roller than in the past, and high detection accuracy can be obtained.
Therefore, according to the non-contact temperature sensor of the present invention, the thermistor part is protected, and the temperature can be measured in a non-contact manner with high responsiveness and accurately. Suitable for use.

It is the top view (a) and AA sectional view (b) which saw through the inside which shows one Embodiment of the non-contact temperature sensor which concerns on this invention. In this embodiment, it is a top view which shows a sensor part. In this embodiment, it is a perspective view of the principal part which shows the manufacturing process of a sensor part in order of a process. In this embodiment, it is a top view which shows a lead frame attachment process. In this embodiment, it is the top view and front view which show a back surface side frame attachment process. In this embodiment, it is the top view and front view which show a protective film attachment process.

  Hereinafter, an embodiment of a non-contact temperature sensor according to the present invention will be described with reference to FIGS. 1 to 6. 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 FIGS. 1 to 3, the non-contact temperature sensor 1 of the present embodiment includes an insulating film 2, and a thin film thermistor portion 3 (thermistor portion) that is patterned on the surface of the insulating film 2 with the thermistor material. A pair of comb electrodes 4 having a plurality of comb portions 4a on the thin film thermistor portion 3 and patterned to face each other; a pair of pad electrodes 5 patterned on the surface of the insulating film 2; A pair of pattern wiring portions 6 having one end connected to a pair of comb-shaped electrodes 4 and the other end connected to a pair of pad electrodes 5 and patterned on the surface of the insulating film 2, and the surface of the insulating film 2 And a pair of lead frames 7 bonded to the pair of pad electrodes 5 on the side.

As shown in FIGS. 2 and 3, the above-described insulating film 2, thin film thermistor portion 3, comb electrode 4, pad electrode 5 and pattern wiring portion 6 constitute a sensor portion S.
The sensor unit S includes a protective film 8 formed on the surface of the insulating film 2 except for the region where the pad electrode 5 is disposed.

  The thin film thermistor portion 3 is formed in a thermistor forming region 2 a disposed on the leading end side of the insulating film 2. The pad electrode 5 is formed in an electrode formation region 2 b disposed on the base end side of the insulating film 2. Further, the insulating film 2 has a wiring formation region 2c in which the pattern wiring portion 6 is disposed between the thermistor formation region 2a and the electrode formation region 2b. The wiring formation region 2c is formed narrower than the thermistor formation region 2a and the electrode formation region 2b.

  The tip ends of the pair of lead frames 7 are arranged so as to surround the thermistor forming region 2a in a non-contact manner. That is, the front end sides of the pair of lead frames 7 extend to both sides of the thermistor formation region 2a, and further bend in the opposite direction to extend from the side of the thermistor formation region 2a so as to surround the front portion 7a. have. These tip portions 7a are opposed to each other in the proximity state. The base end sides of the pair of lead frames 7 are formed wider than the side portions of the thermistor forming region 2a, and are welded and bonded to the pair of pad electrodes 5 in the electrode forming region 2b.

Accordingly, the pair of lead frames 7 extend in parallel to each other, and only the side portions of the thermistor formation region 2a are formed narrow so as to surround the thermistor formation region 2a. As described above, the thermistor formation region 2a protrudes into a region surrounded by the distal ends of the pair of lead frames 7 without contacting them, and is in a state of floating in the air.
The lead frame 7 may be bonded to the pad electrode 5 by soldering.

  In the non-contact temperature sensor 1 of the present embodiment, the base end side is adhered to the back side of the electrode forming region 2b of the insulating film 2, and the tip end side is disposed so as to surround the thermistor forming region 2a in a non-contact manner. A pair of backside frames 9 and an insulating protective film 10 provided so as to cover the backside of the thermistor forming region 2a in a non-contact manner are provided. Therefore, in this non-contact temperature sensor 1, as shown in FIG. 1B, only the surface side of the insulating film 2 is opened, and the radiant heat from the measurement object (one-dot broken line arrow in FIG. 1). Can receive.

  The back frame 9 is preferably formed of the same metal material as the lead frame 7 in order to prevent deformation due to a difference in thermal expansion coefficient. In addition, the lead frame 7 and the back frame 9 are preferably made of a material having a certain degree of elasticity in order to maintain a position parallel to the measurement object and to restore the position when the sensor is bent.

The pattern wiring portion 6 is formed of a thin film having a thickness of 100 to 300 nm.
The insulating film 2 is formed of, for example, a polyimide resin sheet. 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 the leading 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) ≦ 0.98, 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 wiring portion 6 and the comb-shaped electrode 4 are made of a Cr or NiCr bonding layer having a thickness of 5 to 100 nm formed on the thin film thermistor portion 3 and a film thickness of 50 to 295 nm with a noble metal such as Au on the bonding layer. And an electrode layer formed of
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 protective film 8 is an insulating resin film or the like, for example, a polyimide film having a thickness of 20 μm is employed.
The said protective film 10 is an insulating resin film etc., for example, a polyimide film is employ | adopted.

As described above, the thin film thermistor portion 3 is a metal nitride material, and has a general formula: Ti _x Al _y N _z (0.70 ≦ y / (x + y) ≦ 0.98, 0.4 ≦ z ≦ 0.5, x + y + z = 1), the crystal structure of which is a hexagonal crystal system with a single phase of wurtzite type (space group P6 ₃ mc (No. 186)) is there.

The thin film thermistor portion 3 is a columnar crystal that is formed in a film shape of, for example, a film thickness of 100 to 1000 nm and extends in a direction perpendicular to the surface of the film. Further, it is preferable that the c-axis is oriented more strongly than the a-axis in the direction perpendicular to the film surface.
Whether the a-axis orientation (100) is strong or the c-axis orientation (002) is strong in the direction perpendicular to the film surface (film thickness direction) is determined using X-ray diffraction (XRD). By examining the orientation, from the peak intensity ratio of (100) (Miller index indicating a-axis orientation) and (002) (Miller index indicating c-axis alignment), “(100) peak intensity” / “(( 002) peak intensity ”is less than 1.

A method for manufacturing the non-contact temperature sensor 1 will be described below with reference to FIGS.
The manufacturing method of the non-contact temperature sensor 1 according to the present embodiment includes a thin film thermistor portion forming step for patterning the thin film thermistor portion 3 on the insulating film 2 and a pair of comb-shaped electrodes 4 facing each other on the thin film thermistor portion 3. An electrode forming step of forming a pair of pattern wiring portions 6 on the insulating film 2, a protective film forming step of forming a protective film 8 on the surface of the insulating film 2, and a lead frame on the pad electrode 5. 7, a lead frame bonding step for bonding 7, a back surface frame bonding step for bonding the back frame 9 to the insulating film 2, and a protective film bonding step for bonding the protective film 10 to the back frame 9. .

As an example of a more specific manufacturing method, reactive sputtering is performed in a nitrogen-containing atmosphere using a Ti—Al alloy sputtering target on an insulating film 2 of a polyimide film having a thickness of 50 μm shown in FIG. at _law, formed by _{Ti x Al y N z (x} = 9, y = 43, z = 48) thermistor film thickness 200nm of. 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 30 seconds, exposed to light with an exposure apparatus, and unnecessary portions are removed with a developer, and further at 150 ° C. Patterning is performed by post-baking for minutes. Thereafter, the thermistor film unnecessary Ti _x Al _y N _z by wet etching in a commercial Ti etchant, as shown in (b) of FIG. 3, with a resist peeling the thin-film thermistor portion 3 of a desired shape.

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 100 nm on the bonding layer by sputtering.
Next, after applying a resist solution on the electrode layer formed by a bar coater, pre-baking was performed at 110 ° C. for 1 minute 30 seconds, and after exposure with an exposure apparatus, unnecessary portions were removed with a developer, and 150 ° C. Then, 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 FIGS. 2 and 3C, desired pattern wiring portions 6 and comb-shaped electrodes are removed by resist stripping. 4 is formed.

Further, a polyimide varnish is applied thereon by a printing method, and cured at 250 ° C. for 30 minutes to form a polyimide protective film 8 having a thickness of 20 μm as shown in FIG. Part S is produced.
Next, as shown in FIG. 4, a pair of lead frames 7 are welded to the pair of pad electrodes 5 of the sensor unit S on the base end side. At this time, the pair of lead frames 7 are arranged so as to surround the thermistor formation region 2a on the tip side.

Furthermore, as shown in FIG. 5, a pair of back surface side frames 9 are bonded to the back surface side of the insulating film 2 so as to face the pair of lead frames 7 with an adhesive or the like. At this time, like the front end sides of the pair of lead frames 7, the pair of back side frames 9 are also arranged so as to surround the thermistor formation region 2a on the front end side.
Then, as shown in FIG. 6, a non-contact temperature is obtained by sticking a polyimide film protective film 10 on the pair of backside frames 9 with an adhesive or the like and closing the upper opening between the pair of backside frames 9. The sensor 1 is manufactured.

  In addition, when producing the several sensor part S simultaneously, the several thin film thermistor part 3, the comb-shaped electrode 4, the pattern wiring part 6, the pad electrode 5, and the protective film 10 are formed on the large sheet of the insulating film 2 as mentioned above. After forming, each sensor part S is cut | disconnected from a large format sheet.

  Thus, in the non-contact temperature sensor 1 of the present embodiment, the tip ends of the pair of lead frames 7 are arranged so as to surround the thermistor forming region 2a in a non-contact manner, and the pair of lead frames 7 have elasticity, Since the thermistor forming region 2a protrudes into a hollow region surrounded by the distal end side of the pair of lead frames 7 without contacting the distal end side of the pair of lead frames 7, the thin film thermistor portion 3 is in the surrounding lead frame 7 In addition to being mechanically protected, heat is difficult to escape to the lead frame 7 because it is not in contact with the surrounding lead frame 7, and high detection accuracy can be obtained. The thermistor formation region 2a protrudes in a hollow and non-contact manner, and can be set to a small area by not extending to the lead frame 7, and the sensor can be miniaturized. In addition, when a roller of a copying machine is a measurement object, even if the distance from the roller changes due to a paper jam, the sensor position returns to its original state due to the spring property (elasticity) of the lead frame 7 when the paper is removed. Can be recovered. Therefore, it can be installed closer to the roller than in the past, and high detection accuracy can be obtained.

  In addition, since the base end side is attached to the back side of the electrode forming region 2b of the insulating film 2, and the front end side is provided with a pair of back side frames 9 arranged so as to surround the thermistor forming region 2a in a non-contact manner. The thermistor formation region 2a is mechanically protected by the back surface side frame 9 in addition to the front surface side lead frame 7, and is reinforced with higher rigidity. In addition, the electrode forming region 2b can be supported by being sandwiched between the lead frame 7 and the back frame 9, and the bonding strength between the lead frame 7 and the pad electrode 5 can be maintained to improve the reliability.

Furthermore, since the insulating protective film 10 provided so as to cover the back side of the thermistor formation region 2a in a non-contact manner is provided, the protective film 10 shields radiant heat on the back side, and influences of outside air, etc. Interference with heat from other than the object can be suppressed.
Moreover, since the pattern wiring part 6 is formed with a thin film having a film thickness of 100 to 300 nm, it is reduced by a nano-level thin film as compared with a metal foil having a thickness of about 100 μm that is used as a wiring on a normal printed circuit board or the like. The thermal conductance is greatly reduced, and higher responsiveness can be obtained.
In addition, since the wiring formation region 2c is formed narrower than the thermistor formation region 2a and the electrode formation region 2b, it is difficult for heat to escape through the wiring formation region 2c, and higher responsiveness can be obtained. .

Note that 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) ≦ 0.98, 0.4 ≦ z ≦ 0.5, x + y + z = 1). Since it is made of nitride and its crystal structure is a hexagonal crystal system and is a wurtzite single phase, it has a good B constant without firing and has high heat resistance.
In addition, since this metal nitride material is a columnar crystal extending in a direction perpendicular to the surface of the film, the film has high crystallinity and high heat resistance can be obtained.
Further, in this metal nitride material, by aligning the c-axis more strongly than the a-axis in the direction perpendicular to the film surface, a higher B constant can be obtained than when the a-axis alignment is strong.

  Therefore, in the non-contact temperature sensor 1 of the present embodiment, since the thin film thermistor portion 3 is formed of the thermistor material layer on the insulating film 2, the thin film thermistor is formed without firing and has a high B constant and high heat resistance. The part 3 can use the insulating film 2 having a low heat resistance such as a resin film, and a thin and flexible thermistor sensor having good thermistor characteristics.

  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.

For example, in the above-described embodiment, nothing is formed on the surface opposite to the thin film thermistor portion (the back surface of the thermistor formation region) in the insulating film, but an infrared reflective film may be formed on this portion with Au or the like. I do not care. In this case, it is possible to prevent the interference of radiant heat from other than the measurement object by reflecting the infrared rays from the back surface side by the infrared reflection film.
Moreover, in the said embodiment, although the back surface frame and the protective film are adhere | attached separately, you may integrate these in a case shape with resin etc., and you may adhere | attach on the back surface of an insulating film.

  DESCRIPTION OF SYMBOLS 1 ... Non-contact temperature sensor, 2 ... Insulating film, 2a ... Thermistor formation area, 2b ... Electrode formation area, 2c ... Wiring formation area, 3 ... Thin film thermistor part (thermistor part), 4 ... Comb-shaped electrode, 4a ... Comb part DESCRIPTION OF SYMBOLS 5 ... Pad electrode, 6 ... Pattern wiring part, 7 ... Lead frame, 8 ... Protective film, 9 ... Back surface side frame, 10 ... Protective film, S ... Sensor part

Claims (3)

An insulating film;
A thermistor provided on the surface of the insulating film;
A pair of pad electrodes patterned on the surface of the insulating film;
A pair of lead frames bonded to the pair of pad electrodes on the surface side of the insulating film;
The thermistor portion is provided in a thermistor forming region disposed on the leading end side of the insulating film,
The pad electrode is formed in an electrode formation region disposed on the base end side of the insulating film,
The tip sides of the pair of lead frames are arranged so as to surround the thermistor forming region in a non-contact manner,
The pair of lead frames has elasticity,
The non-contact temperature sensor, wherein the thermistor forming region protrudes into a hollow area surrounded by the distal end sides of the pair of lead frames without contacting the distal end sides of the pair of lead frames. The non-contact temperature sensor according to claim 1.
The base end side is bonded to the back side of the electrode forming region of the insulating film, and the front end side includes a pair of back side frames arranged so as to surround the thermistor forming region in a non-contact manner. Non-contact temperature sensor. The non-contact temperature sensor according to claim 1 or 2,
A non-contact temperature sensor comprising an insulating protective film provided so as to cover the back side of the thermistor formation region in a non-contact manner.

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