JP6726523B2 - Moisture detecting element manufacturing method, water disintegrating wiring film manufacturing method, water disintegrating thin film manufacturing method, moisture detecting element - Google Patents

Description

The present invention relates to a sputtering target used for sputtering, and more particularly to a sputtering target for forming a water-disintegratable aluminum alloy film and a manufacturing method thereof.

BACKGROUND ART Heretofore, as a film made of an aluminum alloy containing indium and the like in aluminum, there is known a film which dissolves in an atmosphere containing water and exhibits water disintegration.

Since the film made of this water-disintegratable aluminum alloy is dissolved by using water, the film can be peeled off without damaging the formed member, and the member can be easily reused. be able to.

In the case of forming such a water-disintegratable film, conventionally, a thermal spraying method has been used in which a water-disintegratable aluminum alloy is melted and fine particles thereof are sprayed onto an object to be film-formed.

However, the film formed by the thermal spraying method has a thickness of 100 μm or more and the surface thereof has irregularities, and therefore it is necessary to flatten the surface of the film after film formation. Due to such a film thickness and surface irregularities, it is difficult to pattern the water-disintegrating thin film formed by the thermal spraying method by the etching method.

Furthermore, if the water-disintegrating thin film is to be formed in a clean atmosphere having a particle density comparable to that of a semiconductor process, the spraying method may contaminate the clean atmosphere with particles emitted.

Conventionally, a sputtering target used for a sputtering method is prepared by melting a material of the sputtering target to prepare an ingot and processing the ingot.

When a water-disintegratable aluminum alloy film is formed by using such a sputtering target, it is preferable that a film having good water-disintegration property equivalent to that of the film formed by the thermal spraying method can be prepared because it can be used for various purposes.

JP, 2005-256063, A International Publication 2012-026349 JP, 2013-140950, A

The present invention has been made in view of the above problems of the conventional technique, and an object thereof is to detect moisture in a thin film, a wiring film, or moisture that has good water disintegration property. It is to provide a manufacturing method capable of manufacturing an element.

The present invention made to achieve the above object is to melt an aluminum alloy in which at least one additive of indium or bismuth or both is added to aluminum, and melt the aluminum alloy by a spraying method of projecting. A spraying step in which droplets are deposited on a metal plate to form a water-disintegrating sprayed material, a film-forming target is carried into a vacuum tank, and the water-disintegrating sprayed material placed in the vacuum tank is used in a sputtering atmosphere. Sputtering in, the thin film forming step of forming a water-disintegrating thin film on the surface of the film-forming target, the water-disintegrating thin film is partially removed, and the remaining water-disintegrating thin film has a predetermined pattern of water. And a processing step of forming a collapsible wiring film, wherein at least a part of the water-disintegratable wiring film is a moisture detection element manufacturing method for producing a moisture detection element that is made disintegratable by contact with moisture. ..
The present invention includes a protective film forming step of forming a protective film on the surface of the water-disintegratable wiring film, and a part of the protective film is removed to form an exposed opening, and the water-disintegratable property is formed on the bottom surface of the exposed opening. And a step of exposing the wiring film, wherein a portion of the water-disintegratable wiring film exposed on the bottom surface of the exposure opening can be brought into contact with moisture.
The present invention is the method for producing a moisture detecting element, wherein the additive in the aluminum alloy is contained in the range of 0.1% by weight or more and 20% by weight or less with respect to 100% by weight of aluminum.
Further, the present invention is to melt an aluminum alloy in which at least one or both of indium and bismuth is added to aluminum, and deposit droplets of the aluminum alloy on a metal plate by a spraying method of projecting. A thermal spraying step of forming a water-disintegrating sprayed material, carrying a film-forming target into a vacuum tank, and sputtering the water-disintegrating sprayed material placed in the vacuum tank in a sputtering atmosphere to form the film. A thin film forming step of forming a water-disintegrating thin film on the surface of an object, and a process of partially removing the water-disintegrating thin film and forming a water-disintegrating wiring film of a predetermined pattern from the remaining water-disintegrating thin film A method for producing a water-disintegrating wiring film, which comprises the steps of:
The present invention is the method for producing a water-disintegrating wiring film, wherein the additive in the aluminum alloy is contained in the range of 0.1% by weight or more and 20% by weight or less with respect to 100% by weight of aluminum.
The present invention is the method for producing a water-disintegrating wiring film, wherein the processing step of forming the water-disintegrating wiring film uses water, warm water, or steam as an etching solution.
Further, the present invention is to melt an aluminum alloy in which at least one or both of indium and bismuth is added to aluminum, and deposit droplets of the aluminum alloy on a metal plate by a spraying method of projecting. A thermal spraying step of forming a water-disintegrating sprayed material, carrying a film-forming target into a vacuum tank, and sputtering the water-disintegrating sprayed material placed in the vacuum tank in a sputtering atmosphere to form the film. A method for producing a water-disintegrating thin film, comprising: a thin-film forming step of forming a water-disintegrating thin film on the surface of an object.
The present invention is the method for producing a water-disintegratable thin film, wherein the additive in the aluminum alloy is contained in the range of 0.1% by weight or more and 20% by weight or less with respect to 100% by weight of aluminum.
The present invention also provides a water-disintegrating wiring film having a water-disintegrating property disposed on a substrate, a protective film covering the water-disintegrating wiring film, the protective film, and the water-disintegrating wiring film formed on the bottom surface. A portion of the water-disintegratable wiring film located on the bottom surface of the exposed opening is made contactable with water, and a portion in contact with the water is made water-disintegratable. In the moisture detecting element, the water-disintegrating wiring film is a water-disintegrating thin film having a predetermined pattern remaining after partial removal, and the water-disintegrating thin film is obtained by loading the substrate into a vacuum chamber. The target placed in the vacuum chamber is a sputtered film formed on the surface of the substrate by being sputtered in a sputtering atmosphere, and the target contains aluminum and at least one of indium and bismuth, or an additive made of both. The moisture detecting element is a water-disintegrating sprayed material formed by melting the added aluminum alloy and projecting droplets adhering to the metal plate .
The present invention is a water-disintegrating wiring film having a water-disintegrating property disposed on a substrate, first and second electrodes provided on the water-disintegrating wiring film, and a current is applied to the water-disintegrating wiring film. The water-disintegrating wiring film is exposed at a portion of the flowing current path between the first and second electrodes so that the water-disintegrating wiring film can be brought into contact with water, and the portion in contact with the water can be made to disintegrate in water. In the moisture detecting element, the water-disintegrating wiring film is a water-disintegrating thin film having a predetermined pattern remaining after partial removal, and the water-disintegrating thin film is obtained by loading the substrate into a vacuum chamber. The target placed in the vacuum chamber is a sputtered film formed on the surface of the substrate by being sputtered in a sputtering atmosphere, and the target is formed by adding at least one of indium and bismuth or both of them to aluminum. The moisture detecting element is a water-disintegrating sprayed material formed by melting the added aluminum alloy and depositing the projected droplets on the metal plate .

Even if the ratio of aluminum and the additive is within the range known to have good water-disintegrating property, a melt obtained by heating and melting the additive which is aluminum or indium or bismuth, It is known that the aluminum alloy obtained by cooling does not have good water disintegration property.

The reason is that, according to the research conducted by the inventors of the present invention, since the cooling rate of the melt is slow, when the molten aluminum is cooled to form aluminum crystal grains, the additives gather at the grain boundaries of the aluminum alloy, It was found that the number of particles of the additive dispersed in the aluminum crystal grains was reduced.

On the other hand, even if the content of the additive is within the range known to have good water-disintegrating property, actually, the thermal spray formed by spraying an aluminum alloy that does not have good water-disintegrating property. The product was found to have good water disintegration.

The reason is that the additive collected at the grain boundaries of aluminum crystal grains during thermal spraying is dispersed in molten aluminum when melted during thermal spraying and projected as droplets in that state. This is because when the droplet reaches the film formation target, it is rapidly cooled by heat conduction, and the additive is solidified in a state of being dispersed in aluminum, so that the state of the additive being dispersed in aluminum is maintained. it is conceivable that.

Since the sputtering method does not melt the sputtering target, if a sprayed material in which the additive is dispersed in aluminum is sputtered to obtain a sputtered film, the additive is dispersed in the aluminum in the sputtered film. It is possible to obtain a thin film having a good water disintegration property.

Since the surface of the sputtered film formed by sputtering is flat, a resist film cannot be used for a sprayed film having a rough surface, but it can be used for a sputtered film. It can be patterned into a planar shape.

For example, a resist solution is applied to the surface of a sputtered film having water disintegration and cured to form a resist film, then a desired position of the resist film is removed to form an opening, and the sputtered film is exposed on the bottom surface of the opening. Then, the exposed portion of the sputtered film can be removed by etching, so that the sputtered film can be patterned into the planar shape of the resist film.

Incidentally, an ingot made of an aluminum alloy is processed to create a thermal spray material, a thermal spray material is sprayed to create a water-disintegrating spray material, a water-disintegrating spray material is sputtered to create a water-disintegrating thin film, The water-disintegrating thin film is processed to form a water-disintegrating wiring film, a fuse, and a moisture detecting element.

In order for the water-disintegrable thin film and that obtained by processing the water-disintegrable thin film to have good water-disintegratability, the aluminum alloy constituting the thermal spray material should contain indium or bismuth based on 100% by weight of aluminum. One or both of the additives may be contained in the range of 0.1% by weight or more and 20% by weight or less.

The aluminum alloy forming the thermal spray material may contain silicon in the range of 0.04% by weight or more and 8% by weight or less.
Further, the aluminum alloy forming the thermal spray material can contain titanium in the range of 0.13% by weight or more and 4% by weight or less.

The water-disintegrating sputter target used in the present invention is a sprayed product of an aluminum alloy ingot in which an additive made of either indium or bismuth or both is added to aluminum, and has water-disintegrating properties.

By carrying out sputtering using this water-disintegrating sputter target, it is possible to produce a water-disintegrating thin film made of a water-disintegrating aluminum alloy which is thinner than the sprayed film and has a uniform film thickness and whose surface is flat.
By patterning this water-disintegrating thin film, a wiring film having water-disintegrating property and a moisture detecting element can be obtained.

Further, the water-disintegratable thin film of the present invention can be peeled off by contacting it with water alone or water containing an additive, so that it is suitable as various films for members used in an extremely clean environment. For example, if a water-disintegrating thin film is formed as an adhesion-preventing film on the inner wall surface of the vacuum chamber of the film forming apparatus, the thin film adhered to the inner wall surface of the vacuum chamber can be simply washed with water. Can be removed with.

Flowchart showing an example of water-disintegrating wiring film manufacturing method (A)-(d): Process drawing which shows an example of the manufacturing method of the water-disintegrating sputter target. Example of sputtering apparatus used in the present invention (a)-(f): Process drawing (1) explaining the manufacturing method of this invention. (g) to (j): Process diagrams (2) for explaining the production method of the present invention

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a flow chart for explaining the steps of the method for producing a water-disintegratable wiring film of the present invention, and FIGS. 2A to 2D are steps for explaining the steps for producing a water-disintegratable sputter target. It is a figure.

<Water disintegrating sputter target>
Referring to FIG. 1 and FIG. 2, in the present invention, first, in the ingot making process P1 of FIG. 1, after heating and melting aluminum and an additive made of either indium or bismuth or both, Cool, and make an aluminum alloy containing additives in aluminum.

This aluminum alloy contains the additive in the range of 0.1% by weight or more and 20% by weight or less with respect to 100% by weight of aluminum.
Reference numeral 1 in FIG. 2A indicates an ingot of the aluminum alloy.

Next, in the thermal spray material production step P2 of FIG. 1, the ingot 1 produced in the ingot production step P1 is processed to obtain the wire-shaped thermal spray material 2 as shown in FIG. The aluminum alloy forming the thermal spray material 2 has the same composition as the ingot.
As a processing method for forming the wire-shaped thermal spray material 2, wire drawing, drawing, extrusion, etc. may be mentioned.

Next, referring to FIG. 2(c), in the thermal spraying process P3 of FIG. 1, the thermal spraying material 2 is inserted into the inside of the nozzle 11 from the root side of the nozzle 11 of the thermal spraying device, and the tip 13 of the nozzle 11 is It is placed toward the metal plate 10.

A combustion flame is generated inside the nozzle 11 to melt the thermal spray material 2 inside the tip 13, and the compressed air blown from the root side of the nozzle 11 to the tip 13 side of the thermal spray device causes the droplets of the thermal spray material 2 to be sprayed. Spray from the opening 14 into the air.

Reference numeral 12 denotes a droplet discharged from the opening 14. The droplet 12 flies in the air and reaches the metal plate 10 to be adhered thereto. Grows.
When the thermal spray material 2 is sprayed while moving the nozzle 11 within a predetermined range, a water-disintegrable spray material is formed at a predetermined position on the metal plate 10.
Here, the above-mentioned thermal spraying method was a flame thermal spraying method, but in the case of the present invention, the thermal spraying method may be another thermal spraying method such as arc spraying or plasma spraying.

Reference numeral 15 in FIG. 2D indicates a water-disintegrating sprayed material.
It was observed that the additive in the water-disintegrable spray material 15 was made into particles having a particle diameter of 10 nm or less and uniformly dispersed in the aluminum crystal particles.

If the surface 10a of the metal plate 10 forming the water-disintegratable spray material 15 is roughened in advance before the metal plate 10 is formed by blasting using SiC, for example, the metal plate 10 and the water-disintegrable property are formed. The adhesive force with the thermal spray material 15 increases.

<Thin film forming process>
Next, in the thin film forming step P4, the water-disintegrating sprayed material 15 is placed inside the vacuum chamber 34 of the sputtering apparatus 20 of FIG. 3 together with the metal plate 10.
A vacuum exhaust device 35 and a sputtering gas introduction device 36 are connected to the vacuum chamber 34, and the inside of the vacuum chamber 34 is vacuum exhausted by the vacuum exhaust device 35 to form a vacuum atmosphere.

Next, while maintaining the vacuum atmosphere, the film formation target is loaded into the vacuum chamber 34 and is faced to the water-disintegrable spray material 15. Reference numeral 16 in FIG. 3 indicates the film-forming target.

A sputtering power source 37 is arranged outside the vacuum chamber 34, and the metal plate 10 is electrically connected to the sputtering power source 37. The sputtering gas is introduced from the sputtering gas introduction device 36 into the vacuum atmosphere inside the vacuum chamber 34. When the metal plate 10 is introduced and a voltage is applied to the metal plate 10 by applying a voltage to the metal plate 10 , the metal plate 10 serves as a backing plate, the water-disintegrating spray material 15 serves as a sputtering target, and the surface of the water-disintegrating spray material 15 is sputtered. Is started.

By this sputtering, the sputtered particles fly out from the surface of the water-disintegrable spray material 15, and when the sputtered particles flying in the vacuum atmosphere reach the surface of the film-forming target 16, a water-disintegrating thin film grows on the film-forming target 16. To do.
When the water-disintegratable thin film reaches a predetermined film thickness value, the sputtering is terminated.

Reference numeral 17 in FIG. 4A indicates a water-disintegrating thin film that is entirely formed to have a predetermined film thickness on one surface of the film-forming target 16. By this sputtering, the water-disintegrating thin film 17 can be formed to have a film thickness in the range of several tens nm or more and several μm or less.

The water-disintegrating sprayed material 15 is composed of an aluminum alloy containing an additive in a content ratio within a range that dissolves in an atmosphere containing water and exhibits water-disintegrating property, and the additive is contained in an aluminum crystal. Since it is dispersed, it exhibits water disintegration.

Similar to the water-disintegrable spray material 15, the water-disintegrable thin film 17 obtained by sputtering the water-disintegrable spray material 15 has aluminum crystal grains in which the additive is made into particles having a particle diameter of 10 nm or less and uniformly. It was observed to be dispersed.

<Processing process>
Next, in the processing step P5, a resist solution is applied to the surface of the water-disintegrating thin film 17 and cured, and as shown in FIG. 4B, the resist film 31 is entirely formed on the surface of the water-disintegrating thin film 17. Then, a part of the resist film 31 is removed by a photolithography process or the like, and a resist pattern is formed by the remaining part of the resist film 31.

Reference numeral 33 in FIG. 4C indicates a resist pattern, and an etching opening 32 is formed between the resist patterns 33 so that a part of the water-disintegrating thin film 17 is exposed on the bottom surface. A resist pattern 33 is arranged on the surface of the other part of the water-disintegratable thin film 17.

When the film-forming target 16 in that state is immersed in an etching solution containing water as a main component, the exposed water-disintegrating thin film 17 comes into contact with the etching solution, causing water disintegration, and a portion in contact with the etching solution. Are removed by etching, and the reaction product generated by water disintegration is removed by washing. Instead of immersing the film-forming target 16 in the etching liquid, the etching liquid is sprayed onto the film-forming target 16 so that the water-disintegrating thin film 17 exposed on the bottom surface of the etching opening 32 is brought into contact with the etching liquid to be removed by etching. You may Since the water-disintegratable thin film 17 can be etched with only water, no chemical substance is required and the environmental load can be reduced. Water, high-temperature water, or steam can be used as the etching liquid. In the case of water vapor, it can be used by filling or blowing it into the closed space.

Further, instead of water, a compound capable of dissolving the water-disintegrating thin film 17 may be used to etch away the exposed portion of the bottom surface of the etching opening 32 of the water-disintegrating thin film 17.
The water-disintegrating thin film 17 in the portion where the resist pattern 33 is arranged on the surface remains, and one or more water-disintegrating wiring films are formed from the remaining portion of the water-disintegrating thin film 17.

FIG. 4D shows a state in which the resist pattern 33 has been removed after etching removal, and reference numeral 18 indicates a water-disintegrating wiring film. The plane shape of the water-disintegrating wiring film 18 is the same as the plane shape of the resist pattern 33. For example, when the plane shape of the resist pattern 33 is a narrow linear shape, the plane shape is a narrow linear shape. The shaped water-disintegrating wiring film 18 is created.

Here, when the film-forming target 16 is, for example, a circuit board on which an electronic component is mounted, after the water-disintegrating wiring film 18 is formed, the electronic component is mounted on the film-forming target 16 and the The collapsible wiring film 18 can electrically connect electronic components to each other.

In that case, before mounting the electronic component, in the inspection step P6, it is possible to perform an electrical wiring inspection such as the presence/absence of conduction and the measurement of the resistance value for each water-disintegrating wiring film 18. ..

Then, the result of the wiring inspection is evaluated according to a predetermined standard, and the film-forming target 16 whose wiring inspection result is evaluated as a non-defective product is sent to a place where a post process is performed, electronic parts are mounted, and the water-disintegratable wiring film 18 is provided. An electronic circuit using is created.

On the other hand, the film-forming target 16 evaluated as a defective product by the wiring inspection is moved to a place where the water-disintegrating wiring film removing step P9 is performed, and the water-disintegrating wiring film removing step P9 is performed. With the wiring film 18 exposed, the wiring film 18 is immersed in an etching solution containing water as a main component to remove the water-disintegrating wiring film 18.

Then, the film-forming target 16 from which the water-disintegrating wiring film 18 has been removed is washed and dried, and then returned to the thin film forming step P4 to form a new water-disintegrating wiring film 18.

On the other hand, when the film-forming target 16 is not a circuit board but a semiconductor wafer in which electronic components such as transistors and diodes are formed inside by diffusion of impurities, the electrical characteristics of the water-disintegrating wiring film 18 are reduced. The wiring may be inspected for various measurements, and since the electronic components inside the semiconductor wafer are electrically connected by the water-disintegrating wiring film 18 to form the electronic circuit, the formed electronic Electrically testing the circuit may be a wiring test.

In any case, if the evaluation of the wiring result is a non-defective product, the film-forming target 16 is moved to a place where the post-process is performed, and if the evaluation of the wiring result is a defective product, the film-forming target 16 is a water product. The water disintegratable wiring film removing step P9 is moved to a place where the water disintegrating wiring film removing step P9 is performed, the water disintegrating wiring film 18 is removed, and the thin film forming step P4 is performed again. 18 is formed.

<Post process>
Here, a protective film forming step P7 is provided as the first step of the subsequent steps.
In the protective film forming step P7, the first protective film is entirely formed on one surface of the film-forming target 16 on which the water-disintegrating wiring film 18 is formed.

FIG. 4E is a cross-sectional view of the water-disintegrating wiring film 18 of FIG. 4D viewed from a different direction, and the reference numeral 19 indicates a first protective film. The surface and side surfaces of the water-disintegrating wiring film 18 are covered with the first protective film 19.

When the film formation target 16 is a semiconductor wafer, the first protective film 19 is, for example, an organic insulating thin film or an inorganic insulating thin film formed by a sputtering method.

When the film-forming target 16 is a circuit board on which electronic components are mounted, the first protective film 19 may be, for example, the first protective film liquid on the water-disintegrating wiring film 18 before mounting the electronic components. Is an organic insulating thin film or an inorganic insulating thin film formed by coating and curing.

After the first protective film 19 is formed, the first protective film 19 is partially removed by a photolithography process or the like to form a first protective pattern made of the residual material of the first protective film 19.

Reference numeral 20 in FIG. 4(f) is a first protective pattern, and the first protective pattern 20 has a plurality of contact openings formed on the bottom surface to expose a part of the water-disintegrating wiring film 18. 4(f), the first and second contact openings 27 ₁ and 27 ₂ located at both ends of the single water-disintegrating wiring film 18 are shown.

Each water-disintegrating wiring film 18 is covered with the first protective pattern 20 except the bottom surface of the first and second contact openings 27 ₁ and 27 ₂ .

Next, in the electrode forming step P8, after the electrode film is entirely formed on one surface of the film-forming target 16 on which the water-disintegrating wiring film 18 is formed, the electrode film is formed by a photolithography process or the like. Partially removed, and an electrode that contacts the water-disintegrating wiring film 18 on the bottom surface of the contact opening is formed from the residue of the electrode film at the position where each contact opening is located. Reference numerals 21 ₁ and 21 _{2 in} FIG. 5G indicate the first and second electrodes formed in the first and second contact openings 27 ₁ and 27 ₂ of the single water-disintegrating wiring film 18. ing. The electrode film is patterned so that the electrodes formed in different contact openings are not electrically connected, and each electrode comes into contact with the wiring film located on the bottom surface of the opening in which each electrode is arranged, and electrically. Connected. The first and second electrodes 21 ₁ and 21 ₂ are also configured in such a manner, and come into contact with the water-disintegrating wiring film 18 in the portions exposed on the bottom surfaces of the first and second contact openings 27 ₁ and 27 ₂ , It is electrically connected.

When the film-forming target 16 is a circuit board, electronic components can be mounted after the electrodes are formed. When the film-forming target 16 is a semiconductor wafer, it is possible to inspect the operation of the electronic circuit and then divide it into chips to select non-defective products.

On the other hand, a case where the film formation target 16 is further subjected to a post-process to manufacture a moisture detection element will be described.
In the moisture detecting element, a glass substrate can be used as the film formation target 16, and it is not necessary to provide an electronic component on the substrate.

A water-disintegrating wiring film 18 having a linear planar shape is preferably formed on the surface of the substrate. The first electrode 21 ₁ is arranged at one end of the water-disintegrating wiring film 18 and the other end thereof is arranged at the other end. The second electrode 21 ₂ is arranged.

Then, between the first and second electrodes 21 ₁ and 21 ₂ on the first protection pattern 20 in the middle position of the current path when the current flows through the water-disintegrating wiring film 18, that is, on the current path. The first protection pattern 20 at the position between the _first and second electrodes 21 ₁ and 21 ₂ is exposed, and other portions of the first protection pattern 20 and electrodes are covered with a patterned resist or the like.

In that state, the exposed portion of the first protective pattern 20 is removed by dry etching or the like without bringing the water-disintegrating wiring film 18 into contact with moisture, and then the patterned resist is removed. As shown, the exposure opening 30 is formed in the first protection pattern 20, and the moisture detection element 5 in which the water-disintegrating wiring film 18 is exposed on the bottom surface of the exposure opening 30 is created. The etching gas used for the dry etching is a reactive gas that reacts with the first protective pattern 20 to generate gas, but does not react with the water-disintegrating wiring film 18.

If the exposed portion of the water-disintegrating wiring film 18 is exposed to the air atmosphere so that the water-disintegrating wiring film 18 can come into contact with water in the air atmosphere or liquid water, the exposed opening 30 is exposed. Water disintegration occurs when the water disintegratable wiring film 18 exposed on the bottom surface comes into contact with the moisture.
When water collapse occurs, the resistance value of the water-disintegratable wiring film 18 changes.

Here, before the water-disintegrating wiring film 18 comes into contact with moisture, the relationship between the current flowing through the water-disintegrating wiring film 18 and the voltage drop generated in the water-disintegrating wiring film 18 is measured, and the moisture detecting element 5 is measured. When is placed in a measurement environment and the relationship between the current and the voltage drop is repeatedly measured, it is possible to detect the occurrence of water collapse by the change in the relationship.

In addition, after forming the second protective film over one surface of the film-forming target 16 on which the water-disintegrating wiring film 18 is located, the position of the exposure opening 30 and the electrode are connected to the external wiring. It is possible to form a second protective pattern composed of the residual material of the second protective film by removing the second protective film at the position where the second protective film is formed.

Reference numeral 22 in FIG. 5I indicates a second protection pattern, and the water-disintegrating wiring film 18 is exposed at the bottom surface of the exposure opening 30 formed in the second protection pattern 22, and is exposed. When water comes into contact with the water-disintegratable wiring film 18, the water-disintegratable wiring film 18 at the contact portion is water-disintegrated.

The first and second electrodes 21 ₁ and 21 ₂ are covered and protected by the second protection pattern 22 except for the portion (not shown) connected to the external wiring.

When the moisture detecting element 5 is immersed in, for example, liquid water, the water-disintegrating wiring film 18 is disintegrated by water, and the product caused by water disintegration is washed away and removed. ), the surface 27 of the film-forming target 16 located directly below the water-disintegrating wiring film 18 is exposed.

When an electronic circuit is formed on the film-forming target 16 such as a circuit board or a semiconductor wafer, the water-disintegrating wiring film 18 of the present invention is used as a part of the wiring of the electronic circuit. If the water is used and the water-disintegrating wiring film 18 is also brought into contact with the electronic circuit when the water is in contact with the electronic circuit, the operation of the electronic circuit can be safely performed when the water-disintegrating wiring film 18 is disconnected due to water collapse. The connection between the electronic component in the electronic circuit and the water-disintegrating wiring film 18 can be determined so as to stop.

For example, if the water-disintegrating wiring film 18 is provided in the middle of the wiring for supplying electric power from the power source to the electronic circuit, when the water-disintegrating wiring film 18 is disconnected due to water collapse, power is supplied to the electronic circuit. Since it can be stopped, the water-disintegrating wiring film 18 is used as a fuse for water.

<Additives>
In the aluminum alloy of the thermal spray material 2, if the content of indium is less than 0.1% by weight with respect to 100% by weight of aluminum, the reactivity between the water-disintegrating thin film 17 and water tends to decrease. When the content of indium with respect to 1 is more than 20% by weight, the reactivity tends to be too high and the moisture content in the atmosphere causes it to collapse, and it tends to be difficult to form a thermal spray material.

On the other hand, in the aluminum alloy of the thermal spraying material 2, if the content of bismuth is less than 0.1% by weight with respect to 100% by weight of aluminum, the reactivity between the water-disintegratable thin film 17 and water tends to decrease. When the content of bismuth with respect to aluminum exceeds 20% by weight, the reactivity of the water-disintegrating thin film 17 is too high and the water-disintegrating thin film 17 disintegrates due to moisture in the atmosphere, and it becomes difficult to form a wire-shaped thermal spray material. Tend.

The content of the additive in the water-disintegratable thin film 17 is the same as the content of the thermal spray material 2, and the content of silicon and the content of titanium are also the same.
It is preferable that the thermal spray material 2 of the present invention contains an additive in a range of 0.1% by weight or more and 20% by weight or less with respect to 100% by weight of aluminum.

On the other hand, in the case of the present invention, the thermal spray material 2 may further contain silicon.
In this case, regarding the content of silicon in the thermal spraying material 2, it is preferable that the content of silicon is 0.04% by weight or more and 8% by weight or less with respect to 100% by weight of aluminum.

In the aluminum alloy of the thermal spraying material 2, if the content of silicon is less than 0.04% by weight with respect to 100% by weight of aluminum, the effect of controlling the reactivity between the water-disintegrating thin film 17 and water tends to decrease, while When the content of silicon with respect to aluminum exceeds 8% by weight, the reactivity between the water-disintegrating thin film 17 and water tends to decrease.

In addition, when it is not necessary to control the water-disintegrating property of the water-disintegrating thin film 17, or when the water-disintegrating thin film 17 is disintegrated by using high-temperature water, the content of silicon contained in the water-disintegrating thin film 17 is included. The amount can be outside the ranges mentioned above.

In the case of the present invention, the thermal spray material 2 may contain titanium.
In this case, the content of titanium in the thermal spray material 2 is preferably 0.13% by weight or more and 4% by weight or less with respect to 100% by weight of aluminum.

In the aluminum alloy of the thermal spray material 2, if the content of titanium is less than 0.13% by weight with respect to 100% by weight of aluminum, the water-disintegrable thin film 17 is affected by impurities in the aluminum and undergoes heat history. If the solubility exceeds 4% by weight, the segregation of titanium in the water-disintegrating thin film 17 tends to increase.

An example of the water-disintegrating aluminum alloy containing indium in aluminum is, for example, Al-In-Si-Ti.
This Al-In-Si-Ti is 2.0 wt% or more and 3.5 wt% or less, preferably 2.5 wt% or more and 3.0 wt% or less In, 0.2 wt% with respect to Al100 wt%. % To 0.5% by weight of Si, and 0.13% to 0.25% by weight, preferably 0.15% to 0.25% by weight, more preferably 0.17% to 0%. Those containing Ti in an amount of 0.23 wt% or less can be suitably used as the aluminum alloy of the thermal spray material 2.

Here, if the content of In as an additive is less than 2% by weight with respect to 100% by weight of aluminum, the reactivity between the water-disintegrating thin film 17 and water tends to decrease, and exceeds 3.5% by weight. Then, the reactivity between the water-disintegrating thin film 17 and water tends to be very high, the handling of the water-disintegrating thin film 17 may be difficult, and the cost increases as the amount of In increases.

If the Si content is less than 0.2% by weight with respect to 100% by weight of aluminum, the effect of controlling the reactivity between the water-disintegrating thin film 17 and water tends to decrease, and the content exceeds 0.5% by weight. Then, the reactivity between the water-disintegrating thin film 17 and water tends to start to decrease, and when it exceeds 0.6% by weight, the reactivity itself between the water-disintegrating thin film 17 and water tends to decrease.

On the other hand, when the content of Ti is less than 0.13% by weight based on 100% by weight of aluminum, the solubility of the water-disintegratable thin film 17 after the heat history tends to decrease due to the influence of impurities in Al. However, if it exceeds 0.25% by weight, the segregation of Ti in the Al alloy tends to increase.

Further, regarding the content of Ti with respect to 100% by weight of aluminum, considering the amount of Si added and the concentration of impurities such as Cu, 0.15% by weight or more is preferable, and 0.17% by weight or more is further preferable. Considering segregation, it is preferably 0.23% by weight or less.

Examples of the water-disintegrating aluminum alloy used in the present invention include Al-Bi-Si-Ti-Ce-Mg.
The Al-Bi-Si-Ti-Ce-Mg contains 0.2% by weight or more and 2% by weight or less, preferably 0.5% by weight or more and 1.5% by weight or less of Bi with respect to 100% by weight of Al. , 1.5 wt% to 8 wt%, preferably 3 wt% to 5 wt% Si, 0.2 wt% to 4 wt%, preferably 1 wt% to 2 wt% Ti is included, and 0.2 wt% or more and 2 wt% or less, preferably 0.2 wt% or more and 0.5 wt% or less Ce is included, and 0.2 wt% or more and 2 wt% or less, preferably A material containing 0.5 wt% or more and 2 wt% or less of Mg can be suitably used as the thermal spray material 2.

Here, if the content of Bi is less than 0.2% by weight with respect to 100% by weight of aluminum, the reactivity between the water-disintegrating thin film 17 and water tends to decrease, and the content is 0.2% by weight or more and 0.5% or more. If it is less than wt%, the reactivity with water tends to be slightly low, but if it is 0.5 wt% or more, the reactivity with water tends to be satisfied, and if it exceeds 2 wt%, it reacts with water. Reactivity tends to increase.

Further, in the thermal spray material 2, if the content of Si is less than 1.5% by weight with respect to 100% by weight of aluminum, the effect of controlling the reactivity between the water-disintegrating thin film 17 and water tends to decrease. If it exceeds 5% by weight, wire drawing tends to be difficult when processing an ingot-shaped water-disintegrating aluminum alloy into a wire, and if it exceeds 8% by weight, it tends to be impossible to process into a wire.

On the other hand, in the thermal spraying material 2, when the content of Ti is less than 0.2% by weight with respect to 100% by weight of aluminum, the solubility of the water-disintegrating thin film 17 when the water-disintegrating thin film 17 undergoes thermal history. When the ingot-shaped water-disintegrating aluminum alloy is processed into a wire, the solubility of the water-disintegrating thin film 17 after the heat history tends to improve as the content of Ti increases. In particular, as the content of Ti with respect to 100% by weight of aluminum exceeds about 4% by weight, wire drawing tends to become difficult.

Further, if Ce is not added in the thermal spray material 2, the solubility of the water-disintegratable thin film 17 after passing through the heat history tends to be poor, and the content in the thermal spray material 2 with respect to 100% by weight of aluminum is low. When it exceeds 0.5% by weight, no particular improvement in solubility can be obtained, and when it exceeds 2% by weight, when an ingot-like water-disintegrating aluminum alloy is processed into a wire, wire drawing tends to be difficult. is there.

Furthermore, in the thermal spraying material 2, if Mg is not added, the water-disintegrating thin film 17 that has undergone thermal history has low stability, reacts with moisture in the atmosphere, and causes a pulverization phenomenon. In the thermal spraying material 2, when the content of Mg is less than 0.2% by weight with respect to 100% by weight of aluminum, some pulverization phenomenon is observed on the surface of the water-disintegratable thin film 17 after thermal history. When it is 0.5% by weight or more, such a pulverization phenomenon does not occur. When the content of Mg in the thermal spray material 2 is more than 2% by weight with respect to 100% by weight of aluminum, wire drawing tends to be difficult when an ingot-shaped water-disintegrating aluminum alloy is processed into a wire.

In the case of the present invention, from the viewpoint of improving the reactivity between the water-disintegrable thin film 17 and water, indium and bismuth are added to the aluminum crystal grains of the aluminum alloy of the water-disintegrable spray material 15 in the above-mentioned thermal spraying step. It is preferable to perform thermal spraying so that particles having a particle diameter of 10 nm or less are dispersed therein.

In this case, particles of indium and bismuth having a particle size larger than 10 nm are present in the aluminum alloy of the water-disintegrable spray 15, or some of particles of indium and bismuth are present in the crystal grains. However, if particles of indium and bismuth having a particle diameter of 10 nm or less are dispersed in the aluminum crystal particles, the water-disintegrating thin film 17 exhibits the water-disintegrating property.

In the case of the present invention, the thickness of the water-disintegrating sprayed material 15 made of a water-disintegrating aluminum alloy is preferably set to 1 mm to 20 mm.

Since the water-disintegrable spray material 15 is made of a water-disintegrable aluminum alloy containing at least either indium or bismuth in aluminum, by performing sputtering using the water-disintegrable spray material 15, It is possible to form the water-disintegrating thin film 17 that is thinner (about 1 μm) than the sprayed film, has a uniform film thickness, and has a flat surface.

Further, the water-disintegrating thin film 17 can be formed on a small member, or the water-disintegrating thin film 17 formed on the substrate can be processed into a fine pattern.

Furthermore, since the water-disintegrating thin film 17 formed by sputtering the water-disintegrating sprayed material 15 can be peeled off only with water, it is suitable as various films for members used in an extremely clean environment. ..

On the other hand, since the water-disintegrable spray material 15 is provided on the metal plate 10 by spraying the spray material 2, the water-disintegrable spray material 15 described above can be produced by a simple process. Can be said.

Particularly, since the ingot 1 made of an aluminum alloy containing a predetermined content of the additive is processed and sprayed using the wire-shaped spray material 2, the water-disintegrable spray material 15 obtained by spraying is It has the same good water disintegration property as the water disintegratable aluminum alloy film formed by the thermal spraying method.

That is, when an ingot is formed by cooling a melt of an aluminum alloy containing an additive at a predetermined content rate, the cooling rate at the time of solidifying the melt is slow, so that indium or the like is present in the grain boundary of the aluminum alloy in the ingot. And the number of particles such as indium dispersed in the aluminum crystal grains is reduced.

On the other hand, when the thermal spraying material 2 obtained by processing the ingot 1 made of a water-disintegratable aluminum alloy is sprayed, the aluminum alloy constituting the thermal spraying material 2 is melted by thermal spraying, and the additive is dispersed in the aluminum, Next, the melt is projected as droplets, reaches the film formation target, and comes into contact with the film formation target, whereby it is rapidly cooled and solidified by heat conduction, and the water-disintegrable spray material 15 is obtained. In the aluminum alloy forming the water-disintegrable spray material 15, the additives are dispersed as particles in the aluminum crystal grains, and the aluminum crystal grains contain a large amount of the additive. Therefore, good water disintegration is exhibited.

When a thin film is obtained by sputtering the water-disintegrable spray material 15, a state in which many particles of an additive such as indium are dispersed in the crystal grains of aluminum is transferred to the film formed by sputtering. Since the additive does not aggregate at the grain boundaries of the aluminum crystal grains by sputtering, a water-disintegrable thin film 17 having a water-disintegrable property comparable to that of the water-disintegrable spray material 15 can be obtained.

It should be noted that the present invention is not limited to the above embodiment, and various changes can be made.
For example, in the above-described embodiment, the case of forming the water-disintegrating sprayed material 15 formed of the sprayed film of the water-disintegrating aluminum alloy on the surface of the metal plate 10 has been described as an example, but the present invention is not limited to this. The water-disintegrable spray material 15 made of a water-disintegratable aluminum alloy sprayed film may be formed on a predetermined substrate.

<Formation of sputtered film>
An ingot made of a water-disintegrating aluminum alloy containing 3% by weight of In, 0.4% by weight of Si, and 0.2% by weight of Ti with respect to 100% by weight of Al is prepared, and the ingot is sliced to form a wire. A thermal spray material having a shape of

The total compounding ratio (% by weight) of this aluminum alloy was Al: 96.53, In: 2.90, Si: 0.39, Ti: 0.19.

Using this wire-shaped thermal spray material, the surface of the backing plate made of copper (Cu) and roughened in advance by the blasting process using SiC is applied to the surface of the thermal spray film of 1.5 mm thickness by the flame spraying method. A water-disintegrating sputter target was formed.

This water-disintegrating sputter target was sputtered by a DC magnetron sputtering method to form a sputtered film having a diameter of 120 mm and a thickness of 1 μm on a glass substrate (Corning #7059 non-alkali glass).

Visual observation of the surface of this sputtered film confirmed metallic luster.
Further, when the sputtered film was analyzed by a fluorescent X-ray analysis method, it was confirmed that the In content was 2.50% by weight.

This sputtered film contains 2.6 wt% of In with respect to 100 wt% of Al, and there is almost no change from the In content with respect to 100 wt% of aluminum in the water-disintegrating sputter target used for film formation. Was confirmed.

<Confirmation of water disintegration>
The glass substrate on which the sputtered film made of the aluminum alloy was formed was immersed in ordinary tap water at a temperature of 70 to 80° C. for 10 minutes to observe the water disintegration property of the sputtered film.
As a result, the sputtered film made of the aluminum alloy disappeared from the glass substrate, which confirmed the water disintegration property of the sputtered film.

2... Thermal spraying material 5... Moisture detecting element 10... Metal plate 15... Water disintegrating spraying material 16... Film forming object 17... Water disintegrating thin film 18... Water disintegrating wiring film 20... Protective film (first protective pattern)
30... Exposure opening

Claims (10)

An aluminum alloy in which at least one of indium and bismuth or both of them are added to aluminum is melted, and droplets of the aluminum alloy are deposited on a metal plate by a spraying method of projecting, and water disintegrating spraying is performed. A thermal spraying process for forming an object,
A film-forming target is carried into a vacuum chamber, and the water-disintegrating sprayed material placed in the vacuum chamber is sputtered in a sputtering atmosphere to form a water-disintegrating thin film on the surface of the film-forming target. Thin film forming process,
A process of partially removing the water-disintegrating thin film, and forming a water-disintegrating wiring film having a predetermined pattern from the remaining water-disintegrating thin film,
Have
A method for producing a moisture detecting element, wherein at least a part of the water-disintegratable wiring film is in contact with moisture so that the moisture detecting element can be disintegrated. A protective film forming step of forming a protective film on the surface of the water-disintegrating wiring film;
An exposure step of removing a part of the protective film to form an exposed opening, and exposing the water-disintegrating wiring film to the bottom surface of the exposed opening;
Have
The method for manufacturing a moisture detecting element according to claim 1, wherein a portion of the water-disintegrating wiring film exposed on the bottom surface of the exposure opening is allowed to come into contact with moisture. The moisture detecting element according to claim 1 or 2, wherein the additive in the aluminum alloy is contained in a range of 0.1% by weight or more and 20% by weight or less with respect to 100% by weight of aluminum. Production method. An aluminum alloy in which at least one of indium and bismuth or both of them are added to aluminum is melted, and droplets of the aluminum alloy are deposited on a metal plate by a spraying method of projecting, and water disintegrating spraying is performed. A thermal spraying process for forming an object,
A film-forming target is carried into a vacuum chamber, and the water-disintegrating sprayed material placed in the vacuum chamber is sputtered in a sputtering atmosphere to form a water-disintegrating thin film on the surface of the film-forming target. Thin film forming process,
A process of partially removing the water-disintegrating thin film, and forming a water-disintegrating wiring film having a predetermined pattern from the remaining water-disintegrating thin film,
A method for producing a water-disintegrating wiring film having: The method for producing a water-disintegrating wiring film according to claim 4, wherein the additive in the aluminum alloy is contained in a range of 0.1% by weight or more and 20% by weight or less with respect to 100% by weight of aluminum. The method for producing a water-disintegratable wiring film according to claim 4 or 5, wherein in the processing step of forming the water-disintegratable wiring film, water, hot water, or steam is used as an etching solution. An aluminum alloy in which at least one of indium and bismuth or both of them are added to aluminum is melted, and droplets of the aluminum alloy are deposited on a metal plate by a spraying method of projecting, and water disintegrating spraying is performed. A thermal spraying process for forming an object,
A film-forming target is carried into a vacuum chamber, and the water-disintegrating sprayed material placed in the vacuum chamber is sputtered in a sputtering atmosphere to form a water-disintegrating thin film on the surface of the film-forming target. Thin film forming process,
A method for producing a water-disintegrating thin film having The method for producing a water-disintegratable thin film according to claim 7, wherein the additive in the aluminum alloy is contained in a range of 0.1% by weight or more and 20% by weight or less with respect to 100% by weight of aluminum. A water-disintegrating wiring film having water-disintegrating property disposed on a substrate,
A protective film covering the water-disintegratable wiring film,
An exposure opening formed in the protective film and exposing a part of the water-disintegrating wiring film on the bottom surface,
Have
A portion of the water-disintegrating wiring film located on the bottom surface of the exposed opening is made contactable with moisture, and a portion in contact with the moisture is a water-disintegrating element,
The water-disintegrating wiring film is a water-disintegrating thin film of a predetermined pattern remaining after partial removal,
The water-disintegrating thin film is a sputtered film formed on the surface of the substrate by sputtering the substrate into a vacuum chamber and sputtering the target placed in the vacuum chamber in a sputtering atmosphere.
The target is a water-disintegrating spray formed by melting an aluminum alloy in which an additive made of at least one of indium and bismuth or both is added to aluminum, and projected droplets are deposited on a metal plate. Moisture detection element that is an object . A water-disintegrating wiring film having water-disintegrating property disposed on a substrate,
First and second electrodes provided on the water-disintegrating wiring film,
The water-disintegrating wiring film is exposed at the portion of the current path through which a current flows in the water-disintegrating wiring film, between the first and second electrodes, and is made contactable with water, A moisture detecting element in which the contacting portion is made water-disintegratable,
The water-disintegrating wiring film is a water-disintegrating thin film of a predetermined pattern remaining after partial removal,
The water-disintegrating thin film is a sputtered film formed on the surface of the substrate by sputtering the substrate into a vacuum chamber and sputtering the target placed in the vacuum chamber in a sputtering atmosphere.
The target is a water-disintegrating spray formed by melting an aluminum alloy in which an additive made of at least one of indium and bismuth or both is added to aluminum, and projected droplets are deposited on a metal plate. Moisture detection element that is an object .

Images