JP2010002332A - Thermocouple sensor substrate and its method of manufacturing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermocouple sensor substrate capable of constituting a thermocouple sensor substrate by an easy method without requiring a complicated constitution, and to provide its method of manufacturing. <P>SOLUTION: Wiring patterns are formed on both sides of an insulating layer. A copper wiring pattern 100 is formed on the surface side, and a nickel wiring pattern 101 is formed on the back surface side. One-side ends of these wiring patterns are provided with sensors 102 contacting with liquid and gas to be measured for measuring their temperatures, and edges of other ends are provided with connectors 103 connected to a measuring apparatus. The sensor 102 constitutes a thermocouple by the junction of the different types of metals of the copper wiring pattern 100 and the nickel wiring pattern 101 and measures a temperature by the use of a phenomenon that a thermoelectromotive force is generated at the junction. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a thermocouple sensor substrate used for a temperature sensor and a method for manufacturing the same, and more particularly to a thermocouple sensor substrate that is easy to manufacture and a method for manufacturing the same.

  Known temperature sensors include platinum resistance thermometers, thermistors, thermocouples, and the like. Among them, thermocouples are widely used because they have advantages of high measurement accuracy and relatively low cost. The thermocouple uses a phenomenon (Seebeck effect) in which a closed circuit is formed by joining two kinds of metal materials, and when the junction is exposed to different temperatures, a thermoelectromotive force is generated and current flows.

  These thermocouples generally used linear conductors as thermocouple sensor elements, but in recent years, various thin thermocouples having a shape in which thin metal foils are stacked to form a thin film are known. ing. Since this thin thermocouple has a small heat capacity, it can measure without greatly disturbing the temperature distribution of the object to be measured, and has advantages such as excellent time response.

  In this thermocouple sensor element, a plastic such as polyimide, a composite material such as glass / epoxy, and various ceramics are used as an insulating substrate, and a large number of thermoelectric elements are formed on the substrate at intervals of, for example, 0.3 mm using a fine printed wiring technique. Pairs can be sequenced.

  This makes it possible to measure with high accuracy the temperature distribution in which a large temperature change exists within a small thickness range within the resin, such as inside the fluid resin in the injection molding nozzle or inside the mold. Can do.

As such a temperature sensor using a thermocouple sensor element, a sensor as listed in Patent Document 1 has been proposed.
According to the invention proposed in Patent Document 1, a thermocouple sensor in which thermocouple junctions are arrayed at the end of an elongated plate-like insulating substrate, and different conductors constituting the thermocouple are printed on the surface thereof. It is comprised from the element and the holding body holding this thermocouple sensor element.

This thermocouple sensor element is integrated as a temperature sensor by being inserted into a slit provided in a holding body, and is characterized in that it can be easily attached to a measurement target device.
JP 2002-131144 A

  A thermocouple sensor element used in a temperature sensor proposed in Patent Document 1 has a Ni wiring printed on the surface of a ceramic substrate, a Cu wiring printed on the back, and a through hole provided at an end. Inside, Cu-Ni joining is carried out, and these wirings are electrically connected. The formation of this through hole requires many steps and precision, and since the structure is complicated, skilled techniques are required. For this reason, since the time and cost of formation are increased, there arises a problem that these are harmful to the production.

  The present invention has been made in view of the above problems, and provides a thermocouple sensor substrate that can form a thermocouple sensor substrate by an easy method without requiring a complicated configuration, and a method for manufacturing the same. Objective.

  In order to achieve the above object, according to the present invention, an insulating substrate, a first metal thin film stacked on an upper layer of the insulating substrate, and the first metal thin film are different metals, and the insulating substrate. A second metal thin film laminated on the lower layer of the first metal thin film, and from the upper layer to the lower layer, the etching process of the first metal thin film, the removal process of the insulating portion, and the site where the removal process was performed A thermocouple sensor characterized in that the first metal thin film and the second metal thin film are electrically connected to each other by performing a plating treatment with the same kind of metal as the first metal thin film. A substrate is provided.

  In the above configuration, it is desirable that an insulating layer be formed on each of the outermost layer on the thin film side of the first metal and the outermost layer on the thin film side of the second metal.

  In addition, the outermost insulating layer on the thin film side of the second metal has the second metal thin film exposed only at the connection position between the first metal thin film and the second metal thin film. It is desirable.

  Preferably, the first metal thin film is copper, and the second metal thin film is nickel.

  Further, in order to achieve the above object, the present invention provides a method of laminating a thin film of a dissimilar metal on an upper layer and a lower layer of an insulating substrate, peeling off a part of the thin film on the upper layer, and removing the exposed portion of the insulating layer. And removing the exposed portion by plating with the same kind of metal as the upper thin film from the thin film side of the upper layer, and dissimilarity between the upper layer and the lower layer by the plating process. The present invention provides a method for manufacturing a thermocouple sensor substrate, characterized by electrically connecting metals.

  In this case, it is preferable that an insulating layer is further laminated on the lower thin film to expose the lower thin film at a position where the electrical connection is performed.

  According to the present invention, among the pair of thin films made of different metals laminated on both surfaces of the insulating substrate, a part of one thin film is peeled off to remove the exposed insulating portion and to the other exposed thin film. By performing the plating treatment, it is possible to form a thermocouple by forming a bond of dissimilar metals. For this reason, it becomes possible to form a thermocouple easily, without requiring a complicated process.

Next, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a plan view showing a configuration of a thermocouple sensor substrate, FIG. 1 (a) is a diagram showing a surface side of the thermocouple sensor substrate, and FIG. 1 (b) is a thermocouple sensor. It is the figure which showed the back surface side of the board | substrate.

  As shown in the figure, a wiring pattern is formed on the thermocouple sensor substrate 10, a copper wiring pattern 100 is formed on the front surface side (FIG. 1A), and a nickel wiring pattern 101 is formed on the back surface side. (FIG. 1B). One end of these wiring patterns is provided with a sensor portion 102 for contacting the fluid or gas to be measured and measuring the temperature thereof, and the other end edge portion is a connector portion for connecting to a measuring instrument. 103 is provided.

  In the sensor unit 102, a thermocouple is configured by bonding the copper wiring pattern 100 and the nickel wiring pattern 101, and the temperature is measured using a phenomenon in which a thermoelectromotive force is generated at the bonding point.

FIG. 2 is a cross-sectional view taken along the line AA shown in FIG.
As shown in FIG. 2, the thermocouple sensor substrate 10 is configured by laminating a plurality of members. The insulating layer 200, the nickel foil surface pattern layer 201, the insulating substrate 202, the copper foil layer 203, the copper plating layer 204, and the insulating layer 205 are laminated in order from the lowest layer.

  The lowermost insulating layer 200 and the uppermost insulating layer 205 are not stacked on the connector portion 103 for connecting to the measuring device, but are stacked only from the one end on the sensor portion 102 side in front of the connector portion 103. ing.

  In the sensor unit 102, the nickel foil surface pattern layer 201 and the copper plating layer 204 form a junction. That is, a thermocouple is formed by forming a junction point of dissimilar metals with nickel and copper. A gap 104 in which the nickel foil surface pattern layer 201 is exposed is formed in the insulating layer 200 below the sensor unit 102.

  The connector portion 103 has a shape in which the nickel foil surface pattern layer 201 and the copper plating layer 204 are exposed, and can be electrically connected to a measuring instrument.

Next, a manufacturing method of the thermocouple sensor substrate 10 will be described with reference to FIGS.
FIGS. 3A to 3B are views showing a process for forming a laminated sheet of different kinds of metal, FIG. 3C shows the etching of the metal foil, and FIG. 3D shows the laser removal of the insulating layer. Indicates. 4 (a) to 4 (b) are diagrams illustrating a copper plating process, FIG. 4 (c) is a diagram illustrating a wiring pattern forming process, and FIGS. 5 (a) to 5 (d) are diagrams. It is the figure which showed the formation process of a protective layer.

<Formation process of dissimilar metal laminated laminate>
First, as shown in FIG. 3A, a copper foil layer 203 is laminated on the surface of the insulating substrate 202, and a nickel foil 201 is laminated on the back surface. The laminated member is heated and pressed by a press lamination method to form a laminated plate.

<Etching process>
Next, as shown in FIG. 3B, a part of the copper foil layer 203 is etched to expose the insulating substrate 202 in order to form the sensor unit 102 described above. Then, as shown in FIG. 3C, the insulating substrate 202 exposed from the copper foil layer 203 is removed by a laser device (not shown), so that the hole 206 where the nickel foil surface pattern layer 201 is exposed is formed. Form.

<Copper plating process>
Next, as shown in FIGS. 4A to 4C, copper plating is performed on the upper surface of the copper foil layer 203 and the hole 206. First, in FIG. 4A, a tape (Nitto Denko Corporation: ELEP Masking N-380) 207 is attached to prevent the copper plating from adhering to the surface of the nickel foil surface pattern layer 201. This tape 207 is used for masking when performing metal plating, and is a surface protective material using a polyvinyl chloride film as a support.

Next, as shown in FIG. 4B, copper plating is performed on the copper foil layer 203 and the hole 206 by performing an electroless copper plating process and an electrolytic copper plating process, thereby forming a copper plating layer 204.
First, in the electroless copper plating treatment, the substrate manufactured through the above steps is immersed in an electroless copper plating bath containing a plating solution, and copper is deposited in the copper foil layer 203 and the hole 206. Next, in order to obtain a satisfactory copper plating thickness, an electrolytic copper plating process is performed. In the electrolytic copper plating treatment, copper is deposited on the substrate by passing a current through the plating solution and the substrate after the electroless copper plating treatment immersed in the plating solution. Thereby, the copper plating layer 204 having a sufficient thickness can be laminated in the copper foil layer 203 and the hole 206. Then, when the copper plating step is completed, the tape 207 is peeled off (FIG. 4C).
By this copper plating step, a junction point can be formed by the nickel foil surface pattern layer 201 and the copper plating layer 204, and a thermocouple can be formed by so-called dissimilar metal bonding.

<Wiring pattern formation process>
Next, a copper wiring pattern 100 and a nickel wiring pattern 101 are formed on the stacked substrates shown in FIG. The wiring pattern is formed by performing exposure processing, development processing, and etching processing on the nickel foil surface pattern layer 201 and the copper plating layer 204 using a known technique of photoresist.

<Protective layer formation process>
Next, insulating layers 200 and 205 are formed in the lower layer of the nickel foil surface pattern layer 201 and the upper layer of the copper plating layer 204. The insulating layers 200 and 205 can electrically insulate the nickel foil surface pattern layer 201 and the copper plating layer 204 from the outside, and can also play a role of preventing dust and moisture and preventing oxidation of the metal surface. it can.

  First, the formation of the insulating layer 205 will be described. An insulating layer film that is an ultraviolet curable resin is applied to the entire upper surface of the copper plating layer 204, and the presence or absence of the insulating layer film is selectively formed by ultraviolet exposure (FIG. 5A). ). That is, it is necessary to expose the copper plating layer 204 at a portion that becomes the connector portion 103 of the copper plating layer 204. Therefore, when ultraviolet light exposure is performed, ultraviolet light exposure to a portion that becomes the connector portion 103 is shielded. The insulating layer film is cured at the portion exposed to the ultraviolet rays, and the portion where the exposure is shielded is not cured, but is dissolved and removed by the development process. Thereby, in the connector part 103, the insulating layer 205 which exposed the copper plating layer 204 can be formed (FIG.5 (b)).

  Next, the insulating layer 200 is formed under the nickel foil surface pattern layer 201. First, an insulating layer film, which is an ultraviolet curable resin similar to the above, is applied to the entire surface of the nickel foil surface pattern layer 201 (FIG. 5C), and the presence or absence of the insulating layer film is selectively formed by ultraviolet exposure (FIG. 5). (D)). That is, since it is necessary to expose the nickel foil surface pattern layer 201 at the lower part of the sensor part 102 and the connector part 103, ultraviolet light exposure is shielded at the lower part of the sensor part 102 and the part that becomes the connector part 103. As a result, the insulating layer film is cured at the portion exposed to the ultraviolet rays, and the portion shielded from the ultraviolet rays is not cured, but is soluble and removed by the development process. As a result, the gap 104 is formed in the lower part of the sensor unit 102, and the connector layer 103 can form the insulating layer 200 from which the nickel foil surface pattern layer 201 is exposed.

As described above, according to the embodiment of the present invention, in a part of a substrate in which a pair of different kinds of metals are laminated on both sides, by exposing the other metal surface from one metal surface and performing a plating process there, Since a dissimilar metal junction can be formed, a thermocouple can be easily configured.
Moreover, since it can manufacture with the manufacturing line of the conventional printed wiring technique, manufacture at low cost is realizable, without requiring the manufacturing line for exclusive use of a thermocouple sensor board | substrate.

It is the top view which showed the structure of the thermocouple sensor board | substrate which concerns on embodiment of this invention. It is sectional drawing which showed the AA cross section shown in FIG. FIGS. 3A to 3D are views showing a formation process of a dissimilar metal-clad laminate and a copper plating process. 4A to 4C are views showing a copper plating process and a wiring pattern forming process. FIGS. 5A to 5D are views showing a protective layer forming process.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Thermocouple sensor board | substrate 100 Copper wiring pattern 101 Nickel wiring pattern 102 Sensor part 103 Connector part 104 Air gap 200 Insulating layer 201 Nickel foil surface pattern layer 202 Insulating substrate 203 Copper foil layer 204 Copper plating layer 205 Insulating layer 206 Hole 207 Tape

Claims (6)

An insulating substrate;
A first metal thin film laminated on an upper layer of the insulating substrate;
The first metal thin film is a different metal and is laminated on the lower layer of the insulating substrate;
Consists of
From the upper layer to the lower layer, an etching process of the first metal thin film, a removal process of the insulating portion, and a plating process with the same kind of metal as the first metal thin film on the portion where the removal process has been performed A thermocouple sensor substrate comprising: electrically connecting the first metal thin film and the second metal thin film.   2. The thermocouple sensor substrate according to claim 1, wherein an insulating layer is formed on each of the outermost layer on the thin film side of the first metal and the outermost layer on the thin film side of the second metal.   In the outermost insulating layer on the thin film side of the second metal, the thin film of the second metal is exposed only at a connection position between the thin film of the first metal and the thin film of the second metal. The thermocouple sensor substrate according to claim 1 or 2, characterized in that:   4. The thermocouple sensor substrate according to claim 1, wherein the first metal thin film is copper, and the second metal thin film is nickel. 5. Laminate dissimilar metal thin films on the upper and lower layers of the insulating substrate,
Peeling off a part of the upper thin film,
Removing the insulating part of the exposed part by peeling;
Plating with the same kind of metal as the upper thin film from the upper thin film side with respect to the lower thin film at the removed and exposed position,
A method of manufacturing a thermocouple sensor substrate, wherein the upper layer and the lower layer of different metals are electrically connected by the plating process.   6. The method of manufacturing a thermocouple sensor substrate according to claim 5, wherein an insulating layer is further laminated on the lower thin film to expose the lower thin film at a position where the electrical connection is performed.

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