JP2003028728A - Temperature sensor, and method of manufacturing temperature detecting element therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a pad part from being separated, to allow a Ni foil resistor to be formed into a thin film, and to attain concurrently both miniaturization and a high resistance value. SOLUTION: A Ni foil manufactured by rolling work is bonded onto a surface of a ceramic substrate 10 by an adhesive. The Ni foil is formed into the thin film having a prescribed thickness by wet etching or dry etching. A resist is applied onto the Ni foil, a mask pattern is transcription-exposed thereto, and a portion other than an exposed portion is dissolved and removed to form the Ni foil resistor 11 of a prescribed shape and the pad part 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a temperature sensor and a method for manufacturing the temperature detecting element.

[0002]

2. Description of the Related Art In semiconductor devices, extremely fine temperature control has been demanded along with miniaturization of patterns and enlargement of wafers. A temperature sensor generally used at present is a Pt resistance temperature sensor having a resistance value of about 100Ω. Therefore, in order to measure the temperature with high accuracy, it is necessary to flow a measurement current of 1 to 2 mA to the Pt line due to the limit of circuit technology (limit of high-speed sampling, AD resolution, miniaturization, etc.). In that case, since the temperature sensor has a small size in order to improve high-speed response, a temperature rise larger than the control temperature range occurs. That is, the temperature control range of semiconductors and the like is ± 0.01 ° C, but depending on the shape, the temperature rise of the Pt resistance temperature sensor (heat generation by the measurement current) is as high as 0.1 ° C, which is more than 10 times the control temperature range. In some cases, In such a case, if the flow of the gas to be controlled is constant, the temperature rises at a constant level, so there is no problem in controllability, but the flow of gas is constantly fluctuating from a microscopic perspective. Therefore, the temperature rise of the Pt resistance temperature sensor is constantly changing (since the heat dissipation changes depending on the flow rate), the true target temperature cannot be measured. For example, if the gas flow changes by 10% without changing any other conditions, the detected temperature changes by 10% (about 0.01 ° C) of the temperature rise of 0.1 ° C, and the temperature is changed to true. It will be controlled as temperature. Therefore, there is a demand for a temperature sensor that cannot perform highly accurate control, has a large resistance value in a semiconductor manufacturing apparatus, has a small temperature rise, and can measure temperature with higher accuracy.

The Pt temperature sensor uses a very thin Pt wire having an outer diameter of about 0.01 mm as a resistor and has a resistance value of about 100Ω. Therefore, if it is attempted to measure temperature with high accuracy, P is limited due to the limitation of circuit technology (the limitation of high-speed sampling, AD resolution, miniaturization, etc.).
It is necessary to apply a measurement current of 1 to 2 mA to the t-line. In that case, since the temperature sensor has a small size in order to improve high-speed response, a temperature rise larger than the control temperature range occurs. That is, the temperature control range for semiconductors is ±
Although it is 0.01 ° C, depending on the shape, the temperature rise of the Pt temperature sensor (heat generation due to the measurement current) becomes 0.1 ° C,
It may be 10 times or more the control temperature range.
In that case, if the flow of gas to be controlled is constant,
Since the temperature rise remains constant, there is no problem in controllability, but microscopically, the gas flow is constantly changing, so the temperature rise of the Pt wire temperature sensor is always changing. (Because heat dissipation changes depending on the flow velocity),
This means that the true target temperature cannot be measured. For example,
If the gas flow changes by 10% without any change in other conditions, the detected temperature changes by 10% (about 0.01 ° C) of the temperature rise of 0.1 ° C, and that temperature is regarded as the true temperature. Will be in control. Therefore, there is a demand for a temperature sensor that cannot perform highly accurate control, has a large resistance value in a semiconductor manufacturing apparatus, has a small temperature rise, and can measure temperature with higher accuracy.

The higher the resistance of the temperature sensor, the smaller the measuring current required to detect the same temperature. The temperature rise due to the measured current of the temperature sensor is small because it is proportional to the square of the current. That is, when the resistance value becomes 1 kΩ, the measured current becomes 1/10 of that of Pt100Ω, that is, 0.1 to 0.2 mA, and the temperature rise becomes 1/10. Become. In this case, even if the flow fluctuates, the fluctuation is within the control temperature, and high-precision control is possible.

In the current Pt temperature sensor, a very small Pt wire is wound around a glass tube to manufacture a temperature sensor element, so that a small size and high resistance element cannot be manufactured.
For example, in order to manufacture a resistance value of 1 kΩ, a Pt wire having a length of 10 times is wound, and the element itself becomes large.

[0006]

As described above, the conventional Pt temperature sensor is of the winding type and has a low resistance value.
There was a problem as described below.

Since the resistance value of the Pt wire is usually as low as about 100Ω, it is necessary to supply a large measurement current when measuring a minute temperature change. However, in this case, the thermal effect of self-heating is inevitably large, so that highly accurate measurement cannot be performed.

For example, when a resistor having a resistance value of 100Ω is used, the resistance value is about 0.4Ω when the temperature changes by 1 ° C.
If the current changes and the current at that time is 1 mA, the signal voltage becomes 0.4 mV. Therefore, the power consumption at this time is 10 ⁻⁴ W (W = RI ² = 100 × 10 ⁻³ × 10 ⁻³ ),
If it is a protective tube with a diameter of 1.5 to 2 mm, it will be about 0.1
The temperature rises by 0.2 m ° C. Therefore, if such a temperature sensor is used in a semiconductor manufacturing apparatus to perform temperature control at 10 m ° C., the amount of heat generated by the sensor itself (power consumption) is large and the control is disturbed. Therefore, when a pattern having a pattern width of about 0.1 μm is formed on the large-diameter wafer by photoetching, the temperature of the temperature sensor may be deviated by the heat generated by the sensor itself or the temperature control may be hindered. Can not be.

Since the insulating tube is used to insulate the Pt wire from the protective tube that houses the Pt wire, the outer diameter of the protective tube is further increased and the sensitivity (response) to temperature change is low.

Therefore, the inventors of the present invention have
As a result of conducting various experiments and manufacturing various sensors, when a Ni foil resistor is used instead of the Pt wire,
Since the resistance pattern can be miniaturized by a micromachine or a semiconductor lithography technique, the resistance can be reduced and the power consumption can be reduced, and the above problems can be solved completely.

Further, by providing a trimming pattern on the resistance pattern and adjusting the laser trimming while comparing with the standard element, the resistance value as designed can be obtained, and the variation in the initial resistance value can be reduced.

Further, if the Ni foil resistor is provided on the substrate and the substrate is inserted into the protective tube, the glass tube and the insulating tube are not required, so that the protective tube can be downsized and the response to the temperature change is fast. A temperature sensor was obtained and the above problems could be solved.

In manufacturing the temperature sensor using the Ni foil resistor, the Ni foil manufactured by rolling was used. In this case, in order to increase the resistance value, it is necessary to reduce the thickness of the Ni foil and reduce the pattern width (generally about 3 times the thickness), but the thickness after rolling is about 3 μm. At the limit, if it is rolled thinner than that, handling becomes difficult, and at the same time, problems such as pinholes in the Ni foil, breakage, and uneven thickness occur. Therefore, in addition to forming a desired fine resistance pattern by the photolithography technique and further thinning the film by using the etching technique, pinholes and breakage did not occur, and the thickness could be made uniform. Moreover, since the pattern width can be made smaller when the thickness is thinner (about 3 times the thickness), a smaller Ni foil resistor having a high resistance value (about 1,000Ω) can be obtained. .

The present invention has been made on the basis of the above-mentioned conventional problems and examination results. The purpose of the present invention is to reduce the thickness of the pad portion without peeling it off, thereby reducing the size and increasing the resistance value. It is an object of the present invention to provide a temperature sensor and a method for manufacturing a temperature detection element thereof that can achieve both of them at the same time.

[0015]

In order to achieve the above object, a method of manufacturing a temperature detecting element according to a first invention is a method of manufacturing a temperature detecting element in which a Ni foil resistor is bonded to a substrate, An adhesion step of adhering the Ni foil manufactured by processing to the surface of the substrate with an adhesive, an etching step of thinning this Ni foil to a predetermined thickness by wet etching or dry etching, and applying a resist to the Ni foil. Then, a Ni foil resistor having a predetermined shape and a resistor forming step of forming a pad portion are provided by photolithography and etching.

A method of manufacturing a temperature detecting element according to a second aspect of the present invention is a method of manufacturing a temperature detecting element in which a Ni foil resistor is bonded to a substrate, wherein a Ni foil manufactured by rolling is adhered to the surface of the substrate. A bonding step of bonding with an agent, a resist forming step of applying a resist to the Ni foil to form a Ni foil resistor and a pad portion having a predetermined shape by photolithography and etching, and wet etching the Ni foil resistor or And an etching step of thinning the film to a predetermined thickness by dry etching.

According to a third aspect of the present invention, there is provided a method of manufacturing a temperature detecting element according to the first or second aspect, wherein the Ni foil resistor has a thickness of 3 μm or less.

A method for manufacturing a temperature detecting element according to a fourth aspect of the present invention is the method of manufacturing the temperature detecting element according to the second aspect, wherein the pad portion is masked and etched to leave the pad portion thicker than the thickness of the Ni foil resistor. Is.

A temperature sensor according to a fifth aspect of the present invention comprises a temperature detecting element in which a Ni foil resistor for temperature detection is bonded to a substrate, and an elongated protective tube for accommodating the temperature detecting element. Is thinned to a thickness of 3 μm or less by etching.

A temperature sensor according to a sixth aspect of the present invention comprises a temperature detecting element in which a Ni foil resistor for temperature detection is bonded to a substrate, and an elongated protective tube for accommodating the temperature detecting element. Is made thinner than the thickness of the pad portion by etching.

In the first and second inventions, since the etching step is provided, it is possible to form a Ni foil resistor that is thinner than the thickness limit of the Ni foil by rolling. Therefore, the resistance value can be increased. If the thickness is thin, the pattern width can be narrowed. As the resist, either a positive type or a negative type may be used. In the third and fifth inventions, a Ni foil resistor having a uniform thickness can be obtained without pinholes or breakage. In the fourth and sixth aspects of the invention, the thicker the pad portion is, the higher the strength is, and there is no peeling when the plating process or the lead wire is connected.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below in detail based on the embodiments shown in the drawings. FIG. 1 is a sectional view showing an embodiment of a temperature sensor according to the present invention, FIG. 2 is a sectional view of an element unit, and FIG. 3 is a plan view of a temperature detecting element. In these figures, the temperature sensor indicated as a whole by 1 is
The element unit 2 and the metal pipe 3 for accommodating the element unit 2 constitute a 4-wire type temperature sensor.

The element unit 2 includes a temperature detecting element 4 attached to the tip of a flexible printed circuit board 5,
The temperature detecting element 4 is connected to the flexible printed board 5
An elongated protective tube 6 to be housed together with the external lead wire 7
The external lead wire 7 and the flexible printed circuit board 5 are electrically connected to each other, and the protective tube 6 is hermetically sealed.

The temperature detecting element 4 comprises a ceramic substrate 10 made of alumina or the like, and a Ni foil resistor 11 bonded to the surface of the ceramic substrate 10 with an adhesive. The width of the ceramic substrate 10 is 0.7 to 1 mm,
It is formed in a thin and long sheet shape having a length of 8 to 10 mm and a thickness of about 0.4 mm.

The Ni foil resistor 11 is formed such that the resistance pattern meanders in the longitudinal direction of the ceramic substrate 10 as shown in FIG. The pattern 11A and the return path pattern 11B are formed so as to be shifted by a half pitch so as to be engaged with each other in a non-contact state, and two electrodes are provided at each end portion, four electrode portions (pad portions) 13 (13a to 13) in total.
d). The Ni foil resistor 11 has a thickness of 1 to 3 μm, a width of 6 to 10 μm, and a resistance value of about 1,000.
Ω, the entire surface is covered with an insulating film. However, it may not be covered.

Reference numeral 14 is a resistance pattern for trimming, and several types of resistance patterns having different resistance values such as 1Ω, 2Ω, and 3Ω are formed. The resistance pattern 14 is formed on the Ni foil resistor 1 when the Ni foil resistor 11 is formed from the Ni foil by a well-known photolithography technique and etching technique.
1 are all electrically connected, and are appropriately disconnected when adjusting the resistance value by laser trimming. That is,
If the resistance value of the Ni foil resistor 11 is 995Ω, for example,
Since the resistance value is lower than the desired resistance value of 1,000Ω by 5Ω, one 1Ω resistance pattern and 2Ω resistance pattern 2
The two pieces are separated to form a 1,000 Ω Ni foil resistor 11. The actual trimming is adjusted with finer values.

In such a Ni foil resistor 11, a Ni foil manufactured by rolling is bonded to the surface of the ceramic substrate 10 with an adhesive, and the thickness of the Ni foil itself is reduced by dry etching or wet etching. It can be easily formed by transferring and exposing a mask pattern by a lithographic technique, and dissolving and removing a portion other than the pattern. At this time, the pad portion 13 is also formed at the same time.

Since the flexible printed circuit board 5 is formed of polyimide or the like into an elongated strip shape,
It has the same width as the ceramic substrate 10 and has a width of 4
The circuit patterns 16 of the book are formed in parallel, one end side thereof is connected to each of the external lead wires 7 through the hermetic component 8, and each pad portion 13 of the Ni foil resistor 11 is bump-bonded to the other end side ( Or wire bonding). Of the four circuit patterns 16, for example, two on both sides are used as current lines for supplying a current to the Ni foil resistor 11, and the inner two are signals for detecting the voltage when the Ni foil resistor 11 is energized. Used as a detection line. Such a flexible printed circuit board 5 is inserted into the protective tube 6 together with the hermetic component 8 and presses the temperature detecting element 4 against the inner wall surface of the distal end portion of the protective tube 6.

The external lead wire 7 is composed of four wires (only two wires are shown in FIG. 1), two of which are for current wire and the other two are for signal detection wire, and one end of which is the hermetic part 8. The terminals (lead wires) 20 are respectively connected by solder 21, and the other ends are similarly connected by solder to the circuit pattern 16, respectively. Reference numeral 22 is a stainless braided wire that protects the external lead wire 7.

The hermetic component 8 has four terminals 20, a cylindrical metal ring 23 made of Kovar or the like with both ends open, and the terminal 20 sealed in the metal ring 23. The glass 24 for sealing is used to hermetically seal the opening of the protective tube 6. Each terminal 20
Solder connection portions of the lead wire 7 and the circuit pattern 16 are sealed with synthetic resin 25. A synthetic resin 26 is potted on each terminal 20.

The protection tube 6 is made of SUS304, SUS3.
It is manufactured by laser welding two different diameter pipes consisting of 16 etc., that is, a small diameter pipe 6A and a large diameter pipe 6B with their axes aligned with each other, and an inert gas such as argon, nitrogen or dry air. Or oil is sealed.

The tip of the small diameter pipe 6A is closed,
It consists of a straight pipe with the base end open, with an outer diameter of 1.0 to 1.4 mm, a wall thickness of 0.05 mm, and a length of 20.
The temperature detecting element 4 is built in together with the flexible printed circuit board 5 within about 30 mm. Such a small diameter pipe 6A can be easily manufactured by drawing a pipe material.

The large-diameter pipe 6B is a pipe whose both ends are open, and is fitted into the metal pipe 3 and has an outer diameter of 3.0 mm and a length of 7 to 8 mm. A tubular boss portion 30 forming a connection portion with the small diameter pipe 6A is integrally provided so as to project. The boss portion 30 has an outer diameter of 1.2 to 1.8 mm and a wall thickness of about 0.1 to 0.2 mm, and has the same wall thickness as the large diameter pipe 6B. Such a large-diameter pipe 6B can be easily manufactured by drawing a pipe material, like the small-diameter pipe 6A.

The metal pipe 3 is made of SUS316 or the like and has both ends open, and has an outer diameter of 4.0 mm, an inner diameter of 3.0 mm, and a length of 30 to 50 mm.
The large-diameter pipe 6B and the stainless braided wire 22 of the external lead wire 7 are fitted and inserted in the openings at both ends, and a synthetic resin (thermosetting resin) 31 is filled inside.

Next, a procedure for manufacturing the temperature sensor 1 having the above structure will be described. FIG. 4 is a flowchart showing the manufacturing procedure. First, step (hereinafter referred to as SP) 1
No. 00, an ingot of Ni material is prepared, and this ingot is rolled to produce a Ni foil of a required thickness (SP
101). The thickness of the rolled Ni foil is 3 μm or more, and if it is less than 3 μm, not only the handling becomes difficult,
It is not preferable because pinholes are formed, they are torn, and the thickness becomes uneven.

Next, the Ni foil is bonded to a large ceramic substrate with an adhesive (SP102), and the entire surface of the Ni foil is wet-etched or dry-etched to form a thin film (SP103). In the case of wet etching, it is immersed in an etching solution and gradually dissolved.
In the case of dry etching, the surface of the Ni foil is irradiated with ions or electrons by sputtering, plasma, etc., and is gradually scraped. By such an etching process, the thickness of the Ni foil is set to 1.0 to 3 μm, preferably 1.5 to 3 μm. If it is 1 μm or less, it is not preferable because wrinkles are formed, torn or holes are formed.

Next, the Ni foil is etched into a predetermined pattern by the photolithography technique (photo etching) to manufacture the Ni foil resistor 11 and the pad portion 13 (SP.
104). That is, a resist is applied to the entire surface of the Ni foil by spin coating, and ultraviolet rays (or an electron beam) is applied to transfer and expose a mask pattern on the resist. Next, the exposed resist is dissolved with a solution to remove unnecessary portions of the resist. A negative resist or a positive resist is selected depending on whether the exposed portion is left or removed. The Ni foil is exposed at the portion where the resist is removed, and the exposed Ni foil is removed by wet etching or dry etching. Then, the remaining resist is peeled off, removed, and washed to complete the production of the Ni foil resistor 11 and the pad portion 13 having the predetermined pattern shown in FIG. Here, a series of steps from the application of such a resist to the production of the Ni foil resistor 11 and the pad portion 13 is referred to as a resistor forming step.

Next, in order to increase the strength of the pad portion 13 and to allow easy bonding when attaching electrodes, the surface of the pad portion 13 is plated to be thicker than the Ni foil resistor 11 ( SP105). At this time, the Ni foil resistor is masked. The thickness of the pad portion 13 including the plating layer is about 3 μm. If the thickness of the pad portion 13 is small, the pad portion 13 may not be able to withstand the stress after the plating process and may be peeled off. Further, even if it does not peel off after the plating treatment, it may peel off due to heat during the subsequent bump bonding or upon wire bonding, which is not preferable.

Next, the resistance value of the Ni foil resistor 11 is adjusted by laser trimming to a predetermined resistance value (SP
106). This resistance value adjustment is performed by separating the trimming resistance pattern 14 from the Ni foil resistor 11 by laser trimming while comparing with the standard element.

Then, the ceramic substrate is cut into a predetermined size (SP107). As a result, a plurality of temperature detecting elements 4 are manufactured.

The flexible printed board 5 is manufactured in parallel with the fabrication of the temperature detecting element 4 (SP108), and the temperature detecting element 4 is electrically joined by a solder piece (SP1).
09). Next, in step SP110, the flexible printed circuit board 5 and the terminals 20 of the hermetic component 8 are soldered.

The protective tube 6 is formed in parallel with the fabrication of the temperature detecting element 4 and the flexible printed board 5 (SP11).
1), the temperature detecting element 4 is incorporated inside together with the flexible printed board 5 and the hermetic component 8 to be sealed by the hermetic component 8 (SP112).

At this time, the front end and the back surface of the temperature detecting element 4 are pressed against the inner wall surface of the tip portion of the small diameter pipe 6A. This pressing is performed by utilizing the restoring force due to elasticity of the flexible printed circuit board 5 itself. Before the large-diameter pipe 6B is sealed by the hermetic component 8, an inert gas or oil is sealed inside the protective pipe 6.

The external lead wire 7 is formed in parallel with the fabrication of the temperature detecting element 4, the flexible printed board 5 and the protective tube 6 (SP113), and is electrically connected to the terminal 20 of the hermetic component 8 (SP114). . Further, it is housed in the metal pipe 3 and sealed with the resin 31 (SP115). As a result, the element unit 2 is completed. Then, the performance of the element unit 2 is inspected (SP116), and the accepted products are housed in the metal pipe 3 and sealed with the resin 31 to complete the temperature sensor 1 (SP117).

FIG. 5 is a flow chart showing another manufacturing procedure of the present invention. In this manufacturing method, a Ni foil formed by rolling is adhered to a large ceramic substrate with an adhesive, a resist is applied to the Ni foil, a mask pattern is transferred and exposed by a photolithography technique, and a portion other than the exposed portion is etched by etching. The Ni foil is dissolved and removed to form a predetermined pattern shape, that is, a resistor and a pad portion (SP121). Then, the Ni foil is thinned to a desired film thickness by wet etching or dry etching to manufacture the Ni foil resistor 11 (SP122). At this time, the pad portion 13 is masked so that it is not etched and the thickness is reduced to N.
It is left thicker than the i-foil resistor 11. Other steps are shown in FIG.
Since it is exactly the same as the manufacturing procedure shown in, the same steps will be denoted by the same reference numerals, and the description thereof will be omitted.

According to the temperature sensor 1 having such a structure, since the extremely thin Ni foil resistor 11 is used, a resistor having a higher resistance value than that of the conventional Pt temperature sensor can be formed. Also, the sensor is easy to manufacture,
It can be miniaturized. That is, in the conventional Pt temperature sensor, when the resistance value is increased, the length of the Pt resistance wire becomes long and the shape is inevitably large. Therefore, the resistance value could not be increased to about 100Ω or higher.

On the other hand, the temperature sensor 1 according to the present invention
Uses a Ni foil made by rolling to make a thin film by dry etching or wet etching and forms a predetermined resistance pattern by a photolithography technique. The foil resistor 11 can be manufactured. For example, if the thickness of 3 μm is 2 μm, the resistance value can be increased by about 1.5 times. According to it,
The pattern width can be about 6 μm, and the resistance value can be further increased by about 1.5 times. Due to the synergistic effect, the resistance value can be doubled or more (1.5 × 1.5 = 2.25). Therefore, it is possible to manufacture a resistor having a resistance value of 1,000Ω.

The Ni foil resistor 11 is relatively easy to manufacture as compared with the Pt wire, and the temperature detecting element 4 itself can be formed in an elongated strip shape in spite of the high resistance value.
The diameter of the small-diameter pipe 6A of the protection pipe 6 for storing this is 1.
The diameter can be reduced to 0 mm or less. As a result, the temperature sensor 1 itself can be downsized. Furthermore, if the protective tube 6 can be formed thin, the heat capacity is also reduced, so that the responsiveness to the temperature change of the measurement target can be improved.

Further, since the pad portion 13 is formed to be thicker than the Ni foil resistor 11, it has high strength and is not peeled off during the plating process, bump bonding or wire bonding, and good electrical connection is made. Obtainable.

[Comparison Between Conventional Pt Temperature Sensor and Temperature Sensor According to the Present Invention] A conventional Pt temperature sensor has a resistance value of 100.
A measurement current of 1 to 2 mA is applied at Ω, and a temperature change output is taken out. For example, when the current is 1 mA, the heating value of the resistor (power consumption RI ² ) is 100 × 10 ⁻³ ×
10 ⁻³ = 10 ⁻⁴ W = 0.1 mW. Sensitivity is 1 when TCR (temperature coefficient) of pt = 3850 ppm / ° C.
The sensitivity at ℃ is 100 × 3850 × 10 ⁻⁶ × 1 × 10 ⁻³ = 385 μV /
It becomes ℃. Since the sensitivity at 1 m ° C is 1/1000 of that, it becomes 0.385 µV / m ° C.

On the other hand, when the resistance value is 1,000 Ω, T
When the Ni foil resistor 25 of CR = 6000 ppm / ° C. is used, the resistance value becomes 10 times, so in order to obtain the same sensitivity (temperature change output), the measurement current is 0.064 mA,
That is, it can be 1/15. 0.385 x 10 ^-6 ÷ (1000 x 6000 x 10 ^-6 x 10 ^-3 x
10 ⁻³ ) = 0.064 mA The heat generation amount (power consumption) of the Ni foil resistor 25 is 1000 ×
0.064 x 10 ^-3 x 0.064 x 10 ^-3 = 0.004
It becomes 1/25 at × 10 ⁻³ W = 0.004 mW. Therefore, increasing the resistance value is very effective when used in a semiconductor manufacturing apparatus that requires a temperature control of 1 m ° C. because it can reduce power consumption while maintaining sensitivity.

Although the ceramic substrate 10 is used as the substrate of the temperature detecting element 4 in the above embodiment, the present invention is not limited to this, and the substrate is made of glass, silicon, metal or the like. May be used.

[0053]

As described above, according to the temperature sensor of the present invention, it is possible to reduce the thickness of the Ni foil resistor, reduce the size and increase the resistance value. Therefore, low power consumption is low, and highly accurate temperature measurement can be performed, and it is suitable for temperature measurement of a semiconductor manufacturing apparatus or the like which requires particularly highly accurate temperature control. Further, peeling of the pad portion can be prevented, and good electrical connection can be obtained. Further, the Ni foil resistor is cheaper than the Pt resistance wire and can freely obtain a desired resistance value. Further, according to the method for manufacturing the temperature detecting element of the present invention, a thin Ni foil resistor having a high resistance value can be easily manufactured.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a temperature sensor according to the present invention.

FIG. 2 is a sectional view of an element unit.

FIG. 3 is a plan view of a temperature detecting element.

FIG. 4 is a flowchart showing a manufacturing procedure of the present invention.

FIG. 5 is a flowchart showing another manufacturing procedure of the present invention.

[Explanation of symbols]

1 ... Ni foil resistor temperature sensor, 2 ... Element unit, 3 ...
Metal pipe, 4 ... Temperature detecting element, 5 ... Flexible printed circuit board, 6 ... Protective tube, 7 ... External lead wire, 8 ... Hermetic component, 10 ... Ceramic substrate, 11 ... Ni foil resistor, 13 ... Pad section.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Matsuo Zama             238, Itaizawa, Nakatashiro, Ouchi Town, Yuri District, Akita Prefecture             1 Alpha Electronics Stock             In the company (72) Inventor Toru Okamoto             238, Itaizawa, Nakatashiro, Ouchi Town, Yuri District, Akita Prefecture             1 Alpha Electronics Stock             In the company F-term (reference) 5E034 AA09 AB01 AC13 BA09 BB01                       BB08 DA02 DE16

Claims (6)

[Claims] 1. A method of manufacturing a temperature detecting element, comprising a substrate and a Ni foil resistor joined to the substrate, comprising a step of adhering a Ni foil produced by rolling to the surface of the substrate with an adhesive, An etching step of forming a thin film with a predetermined thickness by wet etching or dry etching; and a resistor forming step of applying a resist to the Ni foil and forming a Ni foil resistor and a pad portion having a predetermined shape by photolithography and etching. A method for manufacturing a temperature detecting element, comprising: 2. A method of manufacturing a temperature detecting element, comprising a substrate and a Ni foil resistor joined thereto, comprising: a bonding step of bonding a Ni foil manufactured by rolling to the surface of the substrate with an adhesive; Resistor forming step of forming a Ni foil resistor and a pad portion in a predetermined shape by applying a resist and photolithography and etching, and etching for thinning the Ni foil resistor to a predetermined thickness by wet etching or dry etching A method of manufacturing a temperature detecting element, comprising: 3. The method for manufacturing a temperature detecting element according to claim 1, wherein the Ni foil resistor has a thickness of 3 μm or less. 4. The method of manufacturing a temperature detecting element according to claim 2, wherein the pad portion is masked and etched to leave the pad portion thicker than the thickness of the Ni foil resistor. Method. 5. A temperature detecting element having a Ni foil resistor for temperature detection bonded to a substrate, and an elongated protective tube for accommodating the temperature detecting element, wherein the Ni foil resistor is etched to a thickness of 3 μm or less. A temperature sensor characterized by being thinned into. 6. A temperature detecting element having a Ni foil resistor for temperature detection joined to a substrate, and an elongated protective tube for accommodating the temperature detecting element, wherein the Ni foil resistor is etched to a thickness greater than that of a pad portion. A temperature sensor characterized by being made thinner.