JP2016051816A - Temperature sensor and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a temperature sensor which can be surface-mounted with a film thermistor part remaining disposed on a top face side and which can be surface-mounted at any one of top and bottom faces; and a method for manufacturing such a temperature sensor.SOLUTION: A temperature sensor comprises: an insulative film 2; a film thermistor part 3 formed, patterning, on a top face of the insulative film from a thermistor material; a pair of pectinate type electrodes 4 formed, by patterning, at least on the top or bottom of the film thermistor part so as to have pectinate parts 4a opposed to each other; and a pair of pattern electrodes 5 formed, by patterning, on the insulative film, and having one ends connected to the pair of pectinate type electrodes. The pair of pattern electrodes are formed so as to extend to end portions of the insulative film; and the end portions of the insulative film are folded back to its bottom face side.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a temperature sensor that is a film-type thermistor temperature sensor capable of surface mounting and a method for manufacturing the same.

  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 1, 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.

  In such a film-type temperature sensor, when performing surface mounting, since the pattern electrode having the terminal portion is formed on the surface side of the insulating film, the surface side of the insulating film needs to be the mounting surface. At the time of mounting, the surface side on which the pattern electrode and the thin film thermistor portion are formed is mounted on a substrate or the like with solder or the like with the surface side turned over to the mounting side.

JP 2014-70953 A JP 2013-2111433 A

The following problems remain in the conventional technology.
That is, in the conventional film-type temperature sensor, when performing surface mounting, the insulating film is turned over during mounting and mounted on a substrate or the like with the thin film thermistor portion facing the mounting side. Is covered with an insulating film, and it is difficult to direct the thin film thermistor portion directly to the measurement object. In addition, in order to surface-mount the thin film thermistor portion toward the object to be measured, it is necessary to form the electrode on the lower surface side of the insulating film. However, the thin film thermistor portion on the upper surface side and the comb electrode and the lower surface electrode In order to connect the two, it is necessary to form a through hole or the like (for example, Patent Document 2). However, in that case, there is a disadvantage that the manufacturing process and the manufacturing cost increase. Furthermore, since the conventional structure is such that surface mounting is possible only on the upper surface side or lower surface side of the insulating film, a structure capable of surface mounting on either the upper surface side or the lower surface side is required. ing.

  The present invention has been made in view of the above-described problems. A temperature sensor that can be surface-mounted while the thin film thermistor portion is disposed on the upper surface side, and can be surface-mounted on either the upper or lower surface, and a method for manufacturing the same. The purpose is to provide.

  The present invention employs the following configuration in order to solve the above problems. That is, the temperature sensor according to the first invention includes an insulating film, a thin film thermistor portion patterned with a thermistor material on the upper surface of the insulating film, and a plurality of at least one above and below the thin film thermistor portion. A pair of comb-shaped electrodes having a comb portion and patterned to face each other, and a pair of pattern electrodes having one end connected to the pair of comb-shaped electrodes and patterned on the insulating film The pair of pattern electrodes are formed to extend to the end portions of the insulating film, and the end portions of the insulating film are folded on the lower surface side.

  In this temperature sensor, the pair of pattern electrodes are formed so as to extend to the end portions of the insulating film, and the end portions of the insulating film are folded on the lower surface side. It is arranged not only on the upper surface side but also on the lower surface side of the end portion, and surface mounting is possible with the thin film thermistor portion facing the upper surface side and the lower surface side as the mounting side. Further, since the pattern electrodes are formed on both the upper and lower surfaces of the insulating film, surface mounting is possible on either the upper or lower surface. Furthermore, since the end portion of the insulating film that is folded and overlapped has springiness (elasticity), when measuring by directly pressing the temperature sensor against the object to be measured, the pressure against the pressing load is reduced. A relaxation effect is obtained.

A temperature sensor according to a second aspect of the invention is characterized in that, in the first aspect of the invention, the temperature sensor includes a folded holding part that holds the end of the insulating film folded.
In other words, this temperature sensor includes a folding holding portion that holds the end portion of the insulating film folded, so that the folded state of the end portion is firmly fixed and maintained by the folding holding portion. Even if strong springiness remains, there is no possibility that the bent portion will be restored.

The temperature sensor according to a third aspect of the present invention is the temperature sensor according to the second aspect, wherein the folded holding portion is an adhesive that bonds and fixes the opposing faces inside the folded end of the insulating film. It is characterized by being.
That is, in this temperature sensor, the folded holding portion is an adhesive that bonds and fixes the opposing surfaces inside the folded end portion of the insulating film, so that the folded state of the end portion is maintained. It can be easily fixed and maintained by an adhesive.

A temperature sensor according to a fourth invention is the temperature sensor according to any one of the first to third inventions, wherein the insulating film has a rectangular shape, and the thin film thermistor portion is formed at the center of the upper surface of the insulating film, The pair of pattern electrodes extends to different ends of the insulating film.
In other words, in this temperature sensor, a pair of pattern electrodes extend to different ends of the rectangular insulating film, so that they are fixed at both ends when mounted on the surface by the pattern electrodes arranged up to both ends. And stable surface mounting becomes possible. In addition, when mounted on a substrate or the like at both end portions on the lower surface side, a gap is generated between the insulating film and the substrate between both end portions, so that even if the center portion is pressed downward, it can bend, Surface mounting with high cushioning properties becomes possible.

A temperature sensor manufacturing method according to a fifth invention is a method of manufacturing the temperature sensor according to any one of the first to fourth inventions, wherein the thin film thermistor portion is patterned on the insulating film. Forming a pair of opposing comb electrodes on the thin film thermistor portion, patterning the pair of pattern electrodes on the insulating film, and connecting the pattern electrodes to the end of the insulating film. And an electrode forming step that extends to the portion, and a folding step that folds the end portion of the insulating film to the lower surface side.
That is, this temperature sensor manufacturing method has a folding step of folding the end portion of the insulating film on the lower surface side, so that the pattern electrode is arranged on the lower surface side without performing through-hole processing or the like. Therefore, a structure that can be surface-mounted on the upper and lower surfaces can be obtained by a simple process.

The present invention has the following effects.
That is, according to the temperature sensor and the manufacturing method thereof according to the present invention, the pair of pattern electrodes are formed to extend to the end portions of the insulating film, and the end portions of the insulating film are folded to the lower surface side. Therefore, surface mounting is possible with the lower surface side as the mounting side while the thin film thermistor portion faces the upper surface side, and surface mounting is possible on either the upper or lower surface.
Therefore, through-hole processing or the like is unnecessary, and a structure that can be surface-mounted on the upper and lower surfaces by low-cost bending processing can be obtained.

It is sectional drawing which shows 1st Embodiment of the temperature sensor which concerns on this invention. In 1st Embodiment, it is the top view (a) and AA sectional view (b) which show a thin film thermistor part formation process. In 1st Embodiment, it is the top view (a) and BB sectional view (b) which show an electrode formation process. In 1st Embodiment, it is the top view (a) and CC sectional view (b) which show a protective film process. In 1st Embodiment, it is the top view (a) and bottom view (b) which show a folding process. It is sectional drawing which shows 2nd Embodiment of the temperature sensor which concerns on this invention.

  Hereinafter, a first embodiment of a temperature sensor according to the present invention will be described with reference to FIGS. 1 to 5. 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 portion 3 patterned with the thermistor material on the upper surface of the insulating film 2, and a plurality of thin film thermistor portions 3 on the thin film thermistor portion 3. A pair of comb electrodes 4 having a comb portion 4a and patterned opposite to each other, and a pair of pattern electrodes having one end connected to the pair of comb electrodes 4 and patterned on the insulating film 2 And 5.

The pair of pattern electrodes 5 are formed to extend to the end of the insulating film 2, and the end of the insulating film 2 is folded on the lower surface side.
The insulating film 2 has a rectangular shape, and the thin film thermistor portion 3 is formed at the center of the upper surface of the insulating film 2.
The pair of pattern electrodes 5 extends to different end portions of the insulating film 2. That is, the pattern electrodes 5 arranged on the upper surface side and the lower surface side at both ends of the insulating film 2 serve as mounting adhesive pad portions, respectively.

Further, the temperature sensor 1 of the present embodiment includes a protective film 6 that covers the thin film thermistor portion 3 on the upper surface 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. The protective film 6 is patterned in a rectangular shape so as to cover the comb portion 4 a together with the thin film thermistor portion 3.

The insulating film 2 is formed in a band shape with, for example, a polyimide resin sheet having a thickness of 7.5 to 125 μm. 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 at the center of the insulating film 2 and is formed of, for example, 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). A thermistor material made of nitride and having a crystal structure of a single phase of a hexagonal wurtzite type is preferable.

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.

A method for manufacturing the temperature sensor 1 will be described below with reference to FIGS.
The manufacturing method of the temperature sensor 1 of 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 patterned on the thin film thermistor portion 3. Forming a pair of pattern electrodes 5 on the insulating film 2 and extending the pattern electrodes 5 to the end of the insulating film 2, and a protective film on the upper surface of the thin film thermistor portion 3. 6, and a folding step of folding the end portion of the insulating film 2 to the lower surface side.

As a more specific example of the manufacturing method, a Ti—Al alloy sputtering target is used on the insulating film 2 of a polyimide film having a thickness of 50 μm, and reactive sputtering is performed in a nitrogen-containing atmosphere, for example, Ti _x Al. A thermistor film of _y N _z (x = 9, y = 43, z = 48) is formed with a film thickness of 200 nm.

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 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 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 desired comb electrodes 4 and pattern electrodes 5 are formed by resist stripping as shown in FIG.

  Further, a polyimide varnish is applied onto the thin film thermistor portion 3 by a printing method and cured at 250 ° C. for 30 minutes to pattern the polyimide protective film 6 having a thickness of 20 μm as shown in FIG.

  Next, as shown in FIGS. 1 and 5, both end portions of the insulating film 2 are folded to the lower surface side and the inner side and folded. As a result, the pattern electrode 5 extends in a folded manner over both the upper and lower surfaces of both ends of the folded insulating film 2. In FIG. 5, the exposed pattern electrode 5 is shown with hatching for easy understanding. Thus, the pattern electrode 5 exposed on the upper surface and the lower surface serves as a bending electrode, and serves as a bonding pad portion made of solder or the like when the upper surface side or the lower surface side is a mounting surface. Thus, since the flexible insulating film 2 is used, the end portion can be easily folded, and the temperature sensor 1 of this embodiment is manufactured.

  When a plurality of temperature sensors are manufactured simultaneously, a large sheet is formed after the plurality of thin film thermistor portions 3, the comb electrodes 4, the pattern electrodes 5, and the protective film 6 are formed on the large sheet of the insulating film 2 as described above. Then, the folding process is performed.

  As described above, in the temperature sensor 1 of the present embodiment, the pair of pattern electrodes 5 are formed to extend to the end portion of the insulating film 2, and the end portion of the insulating film 2 is folded to the lower surface side. Therefore, the pattern electrode 5 is arranged not only on the upper surface side of the insulating film 2 but also on the lower surface side of the end portion, and surface mounting is possible with the thin film thermistor portion 3 facing the upper surface side and the lower surface side as the mounting side. become.

Further, since the pattern electrodes 5 are formed on both the upper and lower surfaces of the insulating film 2, surface mounting is possible on either the upper or lower surface. Furthermore, since the end portion of the insulating film 2 that is folded and overlapped has springiness (elasticity), when the temperature sensor 1 is directly pressed against the measurement object and measured, it is against the pressing load. A pressure relaxation effect is obtained.
In addition, when mounted on a substrate or the like at both end portions on the lower surface side, a gap is generated between the insulating film 2 and the substrate or the like between both end portions, so that even if the center portion is pushed downward, it can be bent. Thus, surface mounting with high cushioning properties is possible.

  Furthermore, in the manufacturing method of this temperature sensor 1, since it has the folding process which folds the edge part of the insulating film 2 on the lower surface side, a pattern electrode is also formed on the lower surface side without performing through-hole processing or the like. The structure which can be arranged and can be surface-mounted on the upper and lower surfaces can be obtained by a simple process.

  Next, a second embodiment of the temperature sensor according to the present invention will be described below with reference to FIG. Note that, in the following description of the embodiment, the same components described in the above embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  The difference between the second embodiment and the first embodiment is that, in the first embodiment, the end of the folded insulating film 2 is simply bent, whereas the temperature sensor of the second embodiment. In 21, as shown in FIG. 6, the surfaces facing each other inside the folded end portion of the insulating film 2 are bonded to each other with an adhesive 22.

That is, in the temperature sensor 21 according to the second embodiment, the folding film holding portion that holds the folded state of the end portion of the insulating film 2 is opposed to the inner side of the folded end portion of the insulating film 2. An adhesive 22 is provided to fix the surfaces together.
In the second embodiment, at the time of the folding step, the adhesive 22 is applied to the facing surface inside the folded end of the insulating film 2 and the folded end is bonded and fixed. As the adhesive 22, a highly heat-resistant epoxy resin, a silicon resin adhesive, or the like is employed.

Therefore, since the temperature sensor 21 of the second embodiment includes a fold-up holding unit that holds the folded state of the end of the insulating film 2, the folded-up state of the end is determined by the fold-up holding unit. A certain adhesive 22 can be firmly fixed and maintained, and even when strong springiness remains, there is no possibility that the bent portion will be restored.
In particular, since the folded holding portion is an adhesive 22 that bonds and fixes the opposing surfaces inside the folded end of the insulating film, the folded state of the end can be easily made by the adhesive 22. Can be fixed and maintained.

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

For example, in each of the above embodiments, the comb portion is patterned on the thin film thermistor portion, but the pattern may be formed below the thin film thermistor portion (the upper surface of the insulating film).
In the second embodiment, the folded portion of the insulating film is adhered with an adhesive to hold the folded state. However, even if the folded state is held by another folding holding portion, I do not care. For example, in a state where the end of the insulating film is folded, the end is fixed with a polyimide tape, the folded portion is crimped and fixed with a clip, or the folded portion is fixed with a pin. An overlap holding part may be adopted.

  DESCRIPTION OF SYMBOLS 1,21 ... Temperature sensor, 2 ... Insulating film, 3 ... Thin film thermistor part, 4 ... Comb electrode, 4a ... Comb part, 5 ... Pattern electrode, 6 ... Protective film, 22 ... Adhesive (folding holding part)

Claims (5)

An insulating film;
A thin film thermistor portion patterned with a thermistor material on the top surface of the insulating film;
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;
One end is connected to the pair of comb electrodes and a pair of pattern electrodes patterned on the insulating film,
The pair of pattern electrodes are formed to extend to the end of the insulating film,
An end portion of the insulating film is folded on the lower surface side. The temperature sensor according to claim 1,
A temperature sensor comprising: a folded holding portion that holds a state in which the end portion of the insulating film is folded. The temperature sensor according to claim 2,
The temperature sensor, wherein the folded holding part is an adhesive that bonds and fixes surfaces facing each other inside the folded end of the insulating film. The temperature sensor according to any one of claims 1 to 3,
The insulating film is rectangular,
The thin film thermistor portion is formed at the center of the upper surface of the insulating film,
The temperature sensor, wherein the pair of pattern electrodes extends to different end portions of the insulating film. A method for manufacturing the temperature sensor according to claim 1,
A thin film thermistor part forming step of patterning the thin film thermistor part on the insulating film;
A pair of comb electrodes facing each other is patterned on the thin film thermistor portion, and a pair of pattern electrodes are formed on the insulating film so that the pattern electrodes extend to the end of the insulating film. Forming an electrode, and
And a folding step of folding the end portion of the insulating film to the lower surface side.

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