JP2009250611A - Sulfuration detecting sensor, sulfuration detection circuit, and manufacturing method of sulfuration detection sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sulfuration sensor capable of detecting a risk before an electronic component fails by sulfuration disconnection or the like, by detecting the accumulated sulfuration amount of the electronic component, such as, chip resistor. <P>SOLUTION: This sulfuration detecting sensor A1 has an insulating substrate 10, a sulfuration detecting body 20, a lower surface electrode 22, a side surface electrode 24, a plating 26 and a protective film 40. The sulfuration detecting body 20 is a conductor constituted mainly of silver which is easily sulfurized, and the protective film 40 has sulfide gas permeability and is formed in a transparent manner. The degree of sulfuration is detected, by viewing a color change of the sulfuration detection body 20 through the protective film 40, by detecting a change of a resistance value of the sulfuration detection body 20, or by detecting reflected light from the sulfuration detecting body 20 by irradiating light onto the upper surface of the sulfuration detecting sensor A1. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a sulfuration sensor, and more particularly to a sensor for detecting a cumulative sulfurization amount of an electronic component such as a chip resistor.

  Many electronic parts using silver electrodes such as chip resistors and chip capacitors are used in electronic devices. When these electronic components are exposed to sulfur-containing sulfur gas, silver becomes silver sulfide and the conduction path becomes narrow, eventually leading to disconnection, and electronic devices may be damaged due to failure of components such as chip resistors. . Conventionally, there has been a problem of sulfide breakage in hot spring areas and rubber manufacturing factories. In recent years, the number of electronic parts used in automobiles has increased, and there have been many troubles in which a minute amount of sulfur components contained in gasoline or the like cause sulfidation of the silver electrode part of the parts.

  For example, the chip resistor shown in FIG. 14 includes an insulating substrate 110, a top electrode 120, a bottom electrode 122, a side electrode 124, a plating 126 (nickel plating 128 and tin plating 132), a resistor 140, and a cover. Although it has a coat 142 and a protective film 144, a sulfide gas such as hydrogen sulfide enters from the boundary position between the protective film 144 and the plating 126 and penetrates deeply into the upper surface electrode 120 depending on the concentration and time, and the upper surface electrode 120. 1 disappears as silver sulfide (for example, the portion 120a in FIG. 14 disappears), the resistance value is changed or the wire is disconnected, and the use environment is not good. The silver on the top electrode may disappear and break in a lifetime of ~ 3 years. In particular, there is a great influence on sulfur components such as hydrogen sulfide and sulfur dioxide contained in petroleum used in factories that handle sulfur such as rubber, hot springs, automobiles and power plants.

Conventionally, as a sulfur gas sensor, there has been a gas sensor that detects a sulfur gas such as hydrogen sulfide using a change in resistance value of a tin oxide-based oxide semiconductor (Patent Document 1).
JP 2002-257767 A

  However, the gas sensor as shown in Patent Document 1 can detect the concentration of gas at that time, but cannot detect the accumulated amount of sulfur exposed to the sulfurized gas for a long time. That is, in the conventional gas sensor as shown in Patent Document 1, the cumulative amount of sulfidation of an electronic component such as a chip resistor is detected, and the danger is detected before the electronic component breaks down due to sulfidation. I couldn't.

  Also, various electronic parts such as resistors that are not easily broken by sulfidation have been devised, but it has not been possible to determine how much sulfur gas the electronic part has been exposed to.

  Thus, the problem to be solved by the present invention is to detect the degree of danger before electronic components such as chip resistors are broken due to a sulfide breakage or the like by detecting the cumulative degree of sulfurization of electronic components such as chip resistors. It is to provide a sulfurization sensor that can be used.

  The present invention was created to solve the above-mentioned problems. First, a sulfide containing as a main material an insulating substrate and a metal formed on the upper surface of the insulating substrate and sulfided by a sulfide gas. Covers the detector, the electrode formed on both ends of the insulating substrate and connected to the sulfide detector, and the uncovered area that is not covered by the electrode in the sulfide detector. The protective film is formed to be transparent or semi-transparent so that the upper surface of the sulfide detector is visible, and is formed of a material having permeability to sulfide gas, and a part of the region not covered by the electrode portion in the sulfide detector is covered. The sulfide gas permeable protective film to be coated and the upper surface of the sulfide detector are formed to be transparent or translucent so that they can be visually observed. Not A sulfide gas non-permeable protective film covering a part of the region, and the sulfide gas permeable protective film and the sulfide gas non-permeable protective film are arranged side by side in the direction between the electrodes. And a protective film that covers a region that is not covered with the electrode portion of the sulfide detector by the protective film and the sulfide gas impermeable protective film.

  In the first configuration, a sulfide detection circuit (a resistance value of sulfide detector or a sulfide detection) is mounted on a printed circuit board on which other electronic components (an electronic component that is a target for detecting the degree of sulfuration) such as a chip resistor are mounted. By providing a sulfidation detection circuit that detects the amount of reflected light by irradiating the body with light, and connecting a sulfidation detection sensor to the sulfidation detection circuit, light is applied to the resistance value of the sulfidation detector and the sulfidation detection body. By detecting the amount of reflected light due to irradiation, the cumulative degree of sulfurization can be detected.

  Further, since the sulfide gas permeable protective film and the sulfide gas non-permeable protective film are formed to be transparent or translucent so that the upper surface of the sulfide detector is visible, the region covered with the sulfide gas permeable protective film Relative comparison between the (sulfurized part) and the area (non-sulfurized area) covered with the sulfide gas impermeable protective film, and the color is comparatively observed to judge the degree of sulfuration accurately. be able to.

 Also, focusing on the boundary area between the area covered with the sulfide gas permeable protective film and the area covered with the sulfide gas impermeable protective film, the area covered with the sulfide gas impermeable protective film is permeable to the sulfide gas. It is not sulfided because it does not sulfidize, but gradually enters the lateral direction from the boundary with the region covered with the sulfide gas permeable protective film and gradually sulphides, so by observing the width of the discolored region in the sulfide detector, The degree of sulfidation that can be observed can be observed, and even if the sulfidation detector is sulfidized and disconnected, the lateral direction continues, so you can know how much the instrument has been exposed to sulfidation gas. it can.

  In addition, since the area of the sulfur detector that is not covered by the electrode is covered with a protective film, there is no chance that solder or solder flux will be placed on the sulfur detector without sulphide detection. There is no hindrance, and if the sulfur detector is sulfided, the surface becomes tattered and peels off, but it is not scattered around and does not adversely affect the surrounding electronic components.

  Second, an insulating substrate, a sulfide detector formed on the upper surface of the insulating substrate and containing a metal sulfided by a sulfide gas as a main material, and formed at both ends of the insulating substrate, the sulfide The electrode part formed in connection with the detector and the region not covered by the electrode part in the sulfide detector are covered, and at least a part is formed transparent or translucent so that the upper surface of the sulfide detector can be visually observed. And a protective film made of a material having permeability to sulfur gas so that the sulfur gas can come into contact with the sulfur detector.

  In the sulfidation detection sensor of the second configuration, the sulfidation detection circuit (resistance of the sulfidation detector is mounted on a printed circuit board on which other electronic components such as chip resistors (electronic components to be detected for sulfidation) are mounted. By providing a sulfuration detection circuit that detects the value and the amount of reflected light by irradiating light to the sulfuration detector, and connecting the sulfuration detection sensor to the sulfuration detection circuit, the resistance value and sulfurization detection of the sulfuration detector The cumulative degree of sulfidation can be detected by detecting the amount of reflected light by irradiating the body with light.

  In addition, since at least a part of the protective film is formed to be transparent or semi-transparent so that the upper surface of the sulfide detector can be visually observed, the color of the sulfide detector can be determined by visually observing the sulfide detector. Can be detected. In addition, since the region exposed from the electrode part of the sulfur detector is covered with a protective film, there is no possibility that solder or solder flux will get on the sulfide detector, and this will interfere with sulfur detection. When the sulfide detector is sulfided, the surface becomes tattered and peels off, but does not scatter around and does not adversely affect the surrounding electronic components.

  Third, an insulating substrate, a sulfide detector formed on the upper surface of the insulating substrate and containing a metal sulfided by a sulfide gas, and formed at both ends of the insulating substrate, the sulfide detector And a region not covered with the electrode portion of the sulfurization detector is exposed to the outside.

  In the third configuration, a sulfuration detection circuit (a resistance value of a sulfuration detector or a sulfurization detection is detected on a printed circuit board on which other electronic components such as a chip resistor (an electronic component that is a target for detecting the degree of sulfurization) are mounted. By providing a sulfidation detection circuit that detects the amount of reflected light by irradiating the body with light, and connecting a sulfidation detection sensor to the sulfidation detection circuit, light is applied to the resistance value of the sulfidation detector and the sulfidation detector. The cumulative degree of sulfuration can be detected by detecting the amount of reflected light due to irradiation. Moreover, since the area | region exposed from the electrode part in the sulfuration detection body is exposed outside, it is possible to detect the degree of sulfuration by visualizing the sulfuration detection body and discriminating the color of the sulfuration detection body.

  Fourthly, in the third configuration, the sulfide region formed of a material that is not permeable to sulfide gas is formed in the end region on both sides in the inter-electrode direction of the region exposed from the electrode portion in the sulfide detector. A gas impermeable protective film is formed, and a region between the pair of sulfurized gas impermeable protective films not covered with the sulfurized gas impermeable protective film in the sulfide detector is exposed to the outside. And

  Therefore, when mounting the sulfidation detection sensor on the printed circuit board by soldering, it is possible to prevent the solder from getting over the electrode portions on both sides and coming into contact with the sulfidation detector.

  According to a fifth aspect of the present invention, in the fourth configuration, the sulfide gas impermeable protective film is formed to be transparent or translucent so that the upper surface of the sulfide detector is visible. Therefore, the degree of sulfidation can be accurately determined by comparing the region exposed to the outside in the sulfuration detector with the region covered with the protective film and comparing the colors.

  Sixth, an insulating substrate, a sulfide detector formed on the upper surface of the insulating substrate and containing a metal sulfided by a sulfide gas as a main material, and formed at both ends of the insulating substrate, the sulfide This is a protective film that covers the electrode part that is connected to the detector and the uncovered area that is not covered by the electrode part of the sulfide detector. A sulfurized gas permeable protective film that covers a part of the region of the body that is not covered with the electrode part, and a sulfur gas non-permeable material that is not covered with the electrode part of the sulfide detector. A sulfide gas non-permeable protective film covering the portion, and the sulfide gas permeable protective film and the sulfide gas non-permeable protective film are arranged side by side in a direction perpendicular to the interelectrode direction. Protective film and the sulfurized gas A protective film covering a region in the transparent protective film is not coated with the electrode portion of the sulfide detector, characterized by having a.

  In the sixth configuration, the sulfuration detection circuit (the resistance value of the sulfuration detector and the sulfuration detection is detected on a printed circuit board on which other electronic components such as a chip resistor (an electronic component for which the degree of sulfurization is to be detected) are mounted. By providing a sulfidation detection circuit that detects the amount of reflected light by irradiating the body with light, and connecting a sulfidation detection sensor to the sulfidation detection circuit, light is applied to the resistance value of the sulfidation detector and the sulfidation detection body. By detecting the amount of reflected light due to irradiation, the cumulative degree of sulfurization can be detected.

  In addition, since the area of the sulfur detector that is not covered by the electrode is covered with a protective film, there is no chance that solder or solder flux will be placed on the sulfur detector without sulphide detection. There is no hindrance, and if the sulfur detector is sulfided, the surface becomes tattered and peels off, but it is not scattered around and does not adversely affect the surrounding electronic components.

  In addition, since the sulfide gas permeable protective film and the permeate gas non-permeable protective film are arranged side by side in a direction perpendicular to the interelectrode direction, the width in the direction perpendicular to the interelectrode direction of the sulfide detector is increased. Even if the region covered with the sulfide gas permeable protective film is sulfided in the thickness direction and disconnected, the region covered with the sulfide gas non-permeable protective film is formed with a width that does not disconnect, so that the sulfide gas Even when the area covered with the permeable protective film is broken by sulfidation, the conduction state is secured by the area covered with the sulfidized gas non-permeable protective film, and the area covered with the permeable protective film is sulfidized. Even in the case of disconnection, the resistance value gradually increases in the state where the conduction state is ensured, so the lifetime of other electronic components mounted on the printed circuit board can be predicted by detecting the resistance value. Long-term sulfur It is suitable for the detection of.

  In the sixth configuration, it is preferable that the sulfide gas permeable protective film and the permeable gas non-permeable protective film are formed in contact with the electrode portions on both sides.

  Seventhly, in the sixth configuration, the sulfide gas permeable protective film and the sulfide gas impermeable protective film constituting the protective film are transparent or translucent so that the upper surface of the sulfide detector can be visually observed. It is formed.

  Therefore, the degree of sulfidation can be accurately determined by comparing the region exposed to the outside in the sulfuration detector with the region covered with the protective film and comparing the colors.

  Also, focusing on the boundary area between the area covered with the sulfide gas permeable protective film and the area covered with the sulfide gas impermeable protective film, the area covered with the sulfide gas impermeable protective film is permeable to the sulfide gas. It is not sulfided because it does not sulfidize, but gradually enters the lateral direction from the boundary with the region covered with the sulfide gas permeable protective film and gradually sulphides, so by observing the width of the discolored region in the sulfide detector, The degree of sulfidation that can be observed can be observed, and even if the sulfidation detector is sulfidized and disconnected, the lateral direction continues, so you can know how much the instrument has been exposed to sulfidation gas. it can.

  Eighth, in any one of the first to seventh configurations, the metal sulfided by the sulfide gas in the sulfide detector is silver or copper.

  Ninth, in any one of the first to eighth configurations, the sulfide gas permeable protective film is a silicon resin or a fluororesin.

  Tenth, in any one of the first to ninth configurations, the sulfide gas impermeable protective film is formed of any one of glass, polyimide, polyester, nylon, epoxy, and acrylic. It is characterized by that.

  In the ninth configuration, it is preferable that the sulfide gas impermeable protective film contains metal powder that is sulfided by the sulfide gas.

  The eleventh is a sulfuration detection circuit, wherein the sulfuration detection sensor having the above-described configuration of the first, second, third, fourth, fifth, sixth, seventh, eighth, ninth, or tenth, a sulfurization detection sensor, and a resistor. Circuit means connected in series, voltage applying means for applying a voltage to both ends of the circuit means to pass a current between the pair of electrode portions, and detecting that the voltage between the pair of electrode portions exceeds a predetermined value And determining means for determining the degree of sulfidation of the sulfidation detector of the sulfidation detection sensor.

  In the eleventh configuration, the voltage application means applies a voltage to both ends of the circuit means in which the sulfuration detection sensor and the resistor are connected in series, and a current flows between the pair of electrode portions. By detecting that the voltage between the pair of electrode portions in the sensor exceeds a predetermined value, the degree of sulfidation of the sulfidation detector of the sulfidation detection sensor is determined. Therefore, by notifying the user of the determination result by the determination means using a warning light, a warning sound, or the like, it is possible to notify the danger of sulfide breakage of other electronic components mounted on the printed circuit board on which the sulfide detection circuit is mounted. .

  Twelfth, in the eleventh configuration, the voltage applying means applies a voltage at a predetermined interval. Therefore, the power consumption of the sulfide detection circuit can be reduced.

  In the thirteenth aspect, in the eleventh or twelfth configuration, the determination unit compares the voltage value between the pair of electrode portions with a predetermined reference voltage value, and amplifies the difference. Output. Therefore, the output signal can be sufficiently detected even when the difference between the voltage value between the pair of electrode portions and the reference voltage value is small.

  Fourteenth is a sulfuration detection circuit, which is a light for irradiating light to the sulfuration detection sensor having the above-described configuration of the first, second, third, fourth, fifth, or seventh, and the sulfurization detector of the sulfurization detection sensor. Irradiation means, light receiving means for receiving reflected light from the sulfide detection body of the sulfuration detection sensor, light quantity detection means for detecting the light quantity of light received by the light receiving means, and the light quantity detected by the light quantity detection means has a predetermined value. And determining means for determining the degree of sulfidation of the sulfidation detection body of the sulfidation detection sensor by detecting that it has exceeded.

  In this thirteenth sulfurization detection sensor, when the light irradiating means irradiates light to the sulfuration detector of the sulfuration detection sensor, the light receiving means receives reflected light from the sulfurization detector of the sulfuration detection sensor. The light amount detecting means detects the light amount of the light received by the light receiving means. And the determination means determines the degree of sulfidation of the sulfidation detector of the sulfidation detection sensor by detecting that the light quantity detected by the light quantity detection means exceeds a predetermined value. Therefore, by notifying the user of the determination result by the determination means using a warning light, a warning sound, or the like, it is possible to notify the danger of sulfide breakage of other electronic components mounted on the printed circuit board on which the sulfide detection circuit is mounted. .

  Fifteenth, there is a sulfuration detection circuit, the sulfuration detection sensor having the above first or seventh configuration, a light irradiation means for irradiating light to the sulfide detection body of the sulfuration detection sensor, and a sulfuration detection sensor. A first light receiving means for receiving reflected light from a sulfide gas permeable protective film, or a light receiving means for receiving reflected light from a sulfide detector; A light receiving means having a second light receiving means for receiving the reflected light of the region covered with the film; a first light quantity detecting means for detecting the light quantity of the light received by the first light receiving means; and the light received by the second light receiving means. Sulfurization of the sulfur detector of the sulfur detection sensor is performed by comparing the light quantity detected by the second light quantity detection means for detecting the light quantity of light and the light quantity detected by the first light quantity detection means with the light quantity detected by the second light quantity detection means. Judgment to determine the degree of And having a stage, a.

  In the sulfurization detection sensor of the fifteenth configuration, when the light irradiation means irradiates light to the sulfide detection body of the sulfuration detection sensor, the first light receiving means is a region covered with the sulfide gas permeable protective film or The reflected light from the area exposed to the outside is received, and the second light receiving means receives the reflected light of the area covered with the sulfide gas impermeable protective film. Then, the first light quantity detecting means detects the light quantity of the light received by the first light receiving means, and the second light quantity detecting means detects the light quantity of the light received by the second light receiving means. Then, the determination unit determines the degree of sulfidation of the sulfidation detector of the sulfidation detection sensor by comparing the light amount detected by the first light amount detection unit with the light amount detected by the second light amount detection unit. Therefore, by notifying the user of the determination result by the determination means using a warning light, a warning sound, or the like, it is possible to notify the danger of sulfide breakage of other electronic components mounted on the printed circuit board on which the sulfide detection circuit is mounted. . Furthermore, the degree of sulfidation can be accurately detected by making a relative comparison between a sulfurized region and a non-sulfided region in the sulfur detector.

  A sixteenth aspect of the present invention is a method of manufacturing the sulfurization detection sensor of the third configuration, wherein the substrate body is an element body of an insulation substrate in the sulfurization detection sensor, and the size of the insulation substrate is a plurality of sizes. A sulfide detector forming step of forming a sulfide detector containing a metal sulfided by a sulfide gas as a main material at least in the region of each sulfide detection sensor on the upper surface of the substrate body, and side electrodes and plating in the sulfide detector In the protective film formation process that forms a protective film that covers areas not covered by the protective film, the protective film formation process that forms a protective film with a soluble material, and the substrate body is divided along the boundary line perpendicular to the inter-electrode direction The side electrodes are formed so as to be connected to the sulfide detector in the primary dividing step of forming a plurality of strip-shaped substrates and the side-surface electrode forming step of forming the side-surface electrodes in a substantially U-shaped cross section with respect to the strip-shaped substrates. Side power Forming step, secondary dividing step of dividing the strip-shaped substrate along the boundary line between the electrodes, plating forming step of forming plating on the exposed region of the sulfide detector and the side electrode, and dissolving the protective film By this, it has the protective film melt | dissolution process which exposes the area | region exposed from the side surface electrode and plating in a sulfurization detection body, It is characterized by the above-mentioned.

  According to the method for manufacturing the sulfurization detection sensor of the sixteenth configuration, the protective film is formed of a soluble material, and the protective film is dissolved after the plating forming step, thereby manufacturing the sulfurization detection sensor of the third configuration. Therefore, the sulfurization detection sensor having the third configuration can be easily manufactured.

  According to the sulfuration detection sensor of the present invention, a sulfuration detection circuit (resistance of a sulfuration detector is mounted on a printed circuit board on which other electronic components such as a chip resistor (an electronic component that is a target for detecting the degree of sulfurization) are mounted. By providing a sulfuration detection circuit that detects the value and the amount of reflected light by irradiating light to the sulfuration detector, and connecting the sulfuration detection sensor to the sulfuration detection circuit, the resistance value and sulfurization detection of the sulfuration detector The cumulative degree of sulfidation can be detected by detecting the amount of reflected light by irradiating the body with light. In particular, when the sulfide detector is made visible by making at least a part of the protective film transparent or translucent, the color of the sulfide detector is discriminated by visually checking the sulfide detector. Thus, the degree of sulfidation can be detected.

  The present invention provides a sulfurization sensor capable of detecting a risk before an electronic component fails due to a sulfide breakage or the like by detecting a cumulative amount of sulfuration of an electronic component such as a chip resistor. The objective was realized as follows. In the figure, the Y1-Y2 direction is a direction perpendicular to the X1-X2 direction, and the Z1-Z2 direction is a direction perpendicular to the X1-X2 direction and the Y1-Y2 direction.

  The sulfide detection sensor A1 according to the present invention is configured as shown in FIG. 1, and includes an insulating substrate 10, a sulfide detector 20, a bottom electrode 22, a side electrode 24, a plating 26, and a protective film 40. is doing. In the sulfuration detection sensor A1, an electrode portion is formed by the lower surface electrode 22, the side surface electrode 24, and the plating 26, and a pair of electrode portions are formed on both sides in the interelectrode direction.

  Here, the insulating substrate 10 is an insulator formed of alumina having a content rate of about 96% (weight ratio). The insulating substrate 10 has a rectangular parallelepiped shape, and has a substantially rectangular shape in plan view. This insulating substrate 10 is used as a base member of the sulfide detection sensor A1.

  Further, the sulfide detector 20 is formed in contact with the upper surface of the insulating substrate 10 and has a substantially layer shape as a whole, and a planar shape thereof is a substantially rectangular shape (may be a substantially rectangular shape or a substantially band shape). The sulfide detector 20 is formed from one end of the insulating substrate 10 to the other end in the inter-electrode direction of the insulating substrate 10 and shorter than the width of the insulating substrate 10 in the width direction. It is formed, and a predetermined distance is provided between the ends of the insulating substrate 10.

  The sulfide detector 20 is a conductor containing, as a main material, a metal sulfided by a sulfide gas, for example, silver that is easily sulfided, and exhibits a silver color when not sulfided. Specifically, when the sulfide detector 20 is formed by paste printing, it contains silver (Ag) and glass, and the content relative to the sulfide detector 20 is 95% by weight. ~ 98%, glass is 2-5%. Further, when formed by silver vapor deposition, or when formed by silver vapor deposition and silver plating (that is, silver plating is performed on a silver vapor deposited region), the sulfide detector 20 is made of silver.

  As for the thickness of the sulfidation detector 20, the longer the time it takes to break the sulfidation as the thickness increases, the thickness of the sulfidation detector 20 depends on the degree of sulfidation to be detected, that is, the accumulated amount of sulfidation to be detected. Is adjusted. The cumulative amount of sulfur referred to here is the cumulative amount of the product of the concentration of the sulfurized gas and the time of exposure to the sulfurized gas. In addition, when the thickness of the sulfide detector 20 is 100 nm or less, it can be performed by silver vapor deposition. When the thickness is 0.1 to 10 μm, silver vapor deposition and silver plating (that is, silver is deposited in the silver vapor deposited region). In the case of 5 to 30 μm, it can be performed by paste printing.

  In addition, when the sulfide detector formed by paste printing is compared with the sulfide detector formed by vapor deposition or plating, the progress of sulfurization is slower in the case of a material close to pure silver such as vapor deposition or plating. This is because the amount of silver per the same thickness is larger in vapor deposition and plating, and the progress of the sulfurization reaction is slower. That is, when detecting the same accumulated amount of sulfuration, the sulfide detector formed by vapor deposition or plating can be formed thinner than the sulfide detector formed by paste printing.

  Further, for example, when the above-described sulfide detector having a thickness of 10 to 15 μm is prepared and a sulfide test is performed in a 3 ppm hydrogen sulfide atmosphere at a temperature of 40 ° C. and a humidity of 85%, the resistance value greatly fluctuates in about 1000 hours. In addition, the content of palladium in the sulfurized detector is within the range of 0 to 10% by weight, and by reducing the silver content, the time for sulfide breakage can be extended, and the palladium content can be increased. The higher the time, the longer the time for breaking the sulfide.

  The bottom electrodes 22 are formed in contact with the bottom surface of the insulating substrate 10 and are formed in a pair at both end regions in the longitudinal direction (X1-X2 direction (see FIG. 1)) of the bottom surface of the insulating substrate 10. In FIG. The width of the bottom electrode 22 in the Y1-Y2 direction is formed substantially the same as the width of the insulating substrate 10 in the Y1-Y2 direction. The lower surface electrode 22 is formed of a silver-based thick film (silver-based metal glaze thick film).

  The pair of side electrodes 24 are formed at both ends in the longitudinal direction (X1-X2 direction) of the insulating substrate 10 and are formed in a substantially U shape so as to cover the top surface, the side surface, and the bottom surface. That is, the side electrode 24 covers and covers a part of the upper surface of the sulfide detector 20, the side surface of the insulating substrate 10, and a part of the lower surface of the lower electrode 22. The length in the width direction of the side electrode 24 is formed to be the same as the length in the width direction of the insulating substrate 10. The side electrode 24 is formed of a silver-based thick film (for example, a silver-based metal glaze thick film).

  The plating 26 has a nickel plating 28 and a tin plating 30.

  Here, the nickel plating 28 is arranged with a substantially uniform film thickness so as to be in contact with the end portion of the protective film 40 by electroplating and to cover the sulfide detector 20, the side electrode 24, and the bottom electrode 22. It is installed. That is, the nickel plating 28 is in contact with and covers the exposed portions of the sulfide detector 20 and the exposed portions of the side electrode 24 and the bottom electrode 22. The nickel plating 28 is made of nickel, and is formed to prevent solder erosion of the sulfide detector 20, the side electrode 24, and the like.

  Further, the tin plating 30 is disposed with a substantially uniform film thickness so as to cover the upper surface of the nickel plating 28 by electroplating. The tin plating 30 is made of tin, and is formed to satisfactorily solder the sulfuration detection sensor A1 to the wiring board. In addition, this tin plating 30 may use solder other than tin.

  Further, the protective film 40 is formed in contact with the upper surface of the sulfide detector 20 and is formed so as to cover a region not covered with the electrode portion of the sulfide detector 20 (that is, a region excluding both sides in the inter-electrode direction). In plan view, it has a substantially rectangular shape. That is, the arrangement position of the protective film 40 will be described in more detail. In the width direction (Y1-Y2 direction), the protective film 40 is formed wider than the width of the sulfide detector 20 and slightly smaller than the width of the insulating substrate 10. The sulfide detector 20 is covered in the width direction. A portion of the protective film 40 that protrudes from the sulfide detector 20 in the Y1-Y2 direction is in contact with the upper surface of the insulating substrate 10. Further, in the direction between the electrodes, the sulfuration detector 20 is formed to be shorter than the length thereof, and the regions on both sides of the sulfide detector 20 are exposed from the protective film 40. As described above, the protective film 40 covers the entire region exposed from the electrode portion of the sulfide detector 20.

  The protective film 40 has a sulfide gas permeability and is transparent. Examples of the material constituting the protective film 40 include silicon resin and fluorine resin (for example, FEP: tetrafluoroethylene-6fluoropropylene copolymer resin). The silicon resin is a polymer formed by a siloxane bond in which Si (silicon) and O (oxygen) are connected in a straight chain, and this siloxane bond (-Si-O-Si-) is flexible due to its large intermolecular distance. In addition, there is a physical property that gas permeability is high because of small molecular rotation steric hindrance and low intermolecular force.

In addition, by providing the protective film 40, it is possible to make the sulfide detector 20 less susceptible to external contact, humidity, and ambient atmosphere. Further, the protective film 40 covers the sulfide detector 20 during manufacturing. Therefore, it can be plated and can be manufactured in the same process as a normal chip resistor, so that it can be manufactured at low cost. In addition, when mounting the sulfidation detection sensor A1 on a printed circuit board, no solder or solder flux is accidentally placed on the sulfidation detector 20, so that sulfidation detection is not hindered.
Further, when the sulfide detector 20 is sulfided, the surface becomes tattered and peels off and scatters to the surroundings. However, since the sulfide detector 20 does not scatter due to the provision of the protective film 40, the surrounding electronic components are not scattered. There is no adverse effect.

  When the sulfuration detection sensor A1 is used for a considerably long period of time, members constituting the electrode portion in the sulfurization detection sensor A1, particularly the lower surface electrode 22 and the side electrode 24, are mixed with 20% or more of palladium. It is preferable to use silver, nickel, nichrome, gold or the like so that the electrode portion is not sulfided.

  The use state and operation of the sulfurization detection sensor A1 having the above configuration will be described. The sulfide detection sensor A1 is used by being mounted on a printed board. That is, the sulfuration detection sensor A1 is mounted on a printed circuit board on which other electronic components such as a chip resistor (an electronic component that is a target for detecting the degree of sulfurization) are mounted. When mounting on a printed circuit board, the sulfurization detection sensor A1 has a pair of electrode portions, and can be mounted by soldering or the like.

  When the printed circuit board is used in an atmosphere containing sulfide gas, other electronic components are sulfided over time, and the sulfide detector 20 in the sulfide detection sensor A1 is sulfided. That is, since the sulfurized gas permeates the protective film 40 and contacts the sulfide detector 20, the sulfurized gas is sulfided according to the concentration of the sulfurized gas and the elapsed time. As the degree of sulfurization progresses, the sulfide detector 20 changes in the order of silver, light brown, purple, gray, and black.

  Then, by visually observing the sulfide detection body 20 in the sulfide detection sensor A1 mounted on the printed circuit board through the transparent protective film 40, the degree of sulfurization can be known by determining the color of the sulfide detection body 20. For example, the degree of sulfidation can be known by periodically monitoring the color of the sulfidation detector 20.

  There is also a method for detecting the degree of sulfidation by a sulfidation detection circuit described below. That is, the sulfuration detection sensor A1 is mounted with other electronic components such as a chip resistor (an electronic component that is a target for detecting the degree of sulfurization), and the sulfuration detection circuits W1 to W4 (FIGS. 2 and 4 to 4). The sulfuration detection circuit A1 is mounted on a printed circuit board provided with any of the sulfuration detection circuits in FIG. 6), and the sulfide detection sensor A1 is mounted on the sulfide detection circuit.

  In addition, by detecting the degree of sulfidation of the sulfidation detection sensor A1 by the sulfidation detection circuits W1 to W4, the degree of sulfidation of other electronic components mounted on the printed circuit board on which the sulfidation detection sensor A1 is mounted indirectly is detected. It is something you can know.

  2 includes a sulfuration detection sensor A1, a resistor 210, and an LED 212. The sulfuration detection sensor A1 and the resistor 210 are connected in series, and the sulfuration detection sensor A1 and the resistor 210 are connected to each other. The LED 212 is connected to the connection point 214 between the end of the resistor 210 opposite to the sulfide detection sensor A1 side and the end of the sulfide detection sensor A1 opposite to the resistor 210 side ( That is, a voltage is applied to both ends of the circuit means in which the sulfuration detection sensor A1 and the resistor 210 are connected in series), the end of the resistor 210 opposite to the sulfurization detection sensor A1 side, and the connection point 214 of the LED 212. A voltage source (voltage applying means) is also connected between the opposite end to the side, and a voltage is applied.

  In the sulfide detection circuit W1, the resistance of the sulfide detector 20 of the sulfide detection sensor A1 increases because the silver constituting the sulfide detector 20 changes to silver sulfide as the sulfurization proceeds. The resistance value does not decrease with time (see FIG. 3). When the sulfuration detector 20 in the sulfuration detection sensor A1 is not sulfided and the resistance value of the sulfide detector 20 is low, the LED 212 does not emit light because the voltage applied to the LED 212 is low. As the sulfuration of the sulfuration detector 20 progresses and the resistance value of the sulfuration detector 20 increases, the voltage applied to the LED 212 also increases, the cumulative amount of sulfuration of the sulfuration detector 20 increases, and the sulfurization detector 20. When the voltage applied to the LED 212 exceeds a certain value by exceeding a certain value (sulfurization detection level (see FIG. 3)), the current flowing through the LED 212 increases suddenly and emits light according to the amount of current. To do. It should be noted that the LED 212 naturally emits light when the sulfide detector 20 is disconnected. That is, the LED 212 functions as “a determination unit that determines the degree of sulfidation of the sulfidation detector of the sulfidation detection sensor by detecting that the voltage between the pair of electrode portions exceeds a predetermined value”. As described above, since the LED 212 emits light when the accumulated amount of sulfuration of the sulfurization detector 20 exceeds a certain value, it can be detected that the accumulated amount of sulfuration has exceeded a certain threshold value.

  4 includes a sulfuration detection sensor A1, a resistor 220, a MOSFET 222, and a resistor 224. The sulfide detection sensor A1 and the resistor 220 are connected in series, and the MOSFET 222 And the resistor 224 are connected in series, and the drain side of the MOSFET 222 is connected to the resistor 224. The gate of the MOSFET 222 is connected to a connection point 228 between the sulfide detection sensor A 1 and the resistor 220. A voltage output terminal 226 is provided between the MOSFET 222 and the resistor 224. Further, between the end of the resistor 220 opposite to the sulfide detection sensor A1 side and the end of the sulfide detection sensor A1 opposite to the resistor 220 side (that is, the sulfide detection sensor A1 and the resistor 220 are in series). A voltage source (voltage applying means) is connected to both ends of the connected circuit means to apply a voltage, and a voltage source is also provided between the end of the resistor 224 opposite to the MOSFET 222 side and the source side of the MOSFET 222. (Voltage application means) is connected and voltage is applied.

  In the sulfide detection circuit W2, the resistance of the sulfide detector 20 of the sulfide detection sensor A1 increases because silver constituting the sulfide detector 20 changes to silver sulfide as the sulfurization proceeds. The resistance value does not decrease with time (see FIG. 3). When the sulfuration detector 20 in the sulfurization detection sensor A1 is not sulfided and the resistance value of the sulfide detector 20 is low, the voltage applied to the gate of the MOSFET 222 is low, so the drain current of the MOSFET 222 is low. And the output of the voltage output terminal 226 becomes high. On the other hand, when the sulfuration of the sulfide detector 20 progresses and the resistance value of the sulfide detector 20 increases, the voltage applied to the gate of the MOSFET 222 also increases, the drain current value of the MOSFET 222 increases, and the voltage output terminal 226 increases. The output of becomes low. Note that the output of the voltage output terminal 226 is naturally low even when the sulfide detector 20 is disconnected. That is, the circuit configured by the MOSFET 222, the resistor 224, and the voltage output terminal 226 indicates that “the degree of sulfidation of the sulfidation detector of the sulfidation detection sensor by detecting that the voltage between the pair of electrodes exceeds a predetermined value. It functions as a “determination means for determining”. By monitoring the output of the voltage output terminal 226 and detecting that the voltage of the voltage output terminal 226 has become lower than a predetermined voltage value, the accumulated amount of sulfuration of the sulfurization detector 20 exceeds a certain threshold value. Can be detected. That is, the predetermined voltage value of the voltage output terminal 226 is detected by setting the voltage value of the voltage output terminal 226 when the resistance value of the sulfuration detector 20 reaches the sulfurization detection level (see FIG. 3) as a predetermined voltage value. Thus, it can be detected that the resistance value of the sulfuration detector 20 has reached the sulfuration detection level.

  Next, the sulfide detection circuit W3 shown in FIG. 5 includes a sulfide detection sensor A1, a resistor 230, a MOSFET 232, an amplifier 234, a reference voltage source 236, and a signal output terminal 238, and the sulfide detection sensor A1. The resistor 230 and the MOSFET 232 are connected in series, and a connection point 240 between the sulfide detection sensor A1 and the resistor 230 is connected to one input terminal (+ input terminal) of the amplifier 234, and the reference voltage source 236 is Are connected to the other input end (− side input end) of the amplifier 234. The resistor 230 is connected to the source side of the MOSFET 232, and a pulse signal is input to the gate. In addition, a voltage source (voltage applying means) is connected between the drain of the MOSFET 232 and the end of the sulfurization detection sensor A1 opposite to the resistor 230 side to apply a voltage. This MOSFET 232 is a P-type channel, and is an enhancement type, and has a characteristic that the drain current increases as the negative voltage (gate voltage) applied between the gate and the source increases.

  In the sulfidation detection circuit W3, the sulfidation detector 20 of the sulfidation detection sensor A1 increases in resistance because the silver constituting the sulfidation detector 20 changes to silver sulfide as sulfidation proceeds. The resistance value does not decrease with time (see FIG. 3). In detecting sulfuration, a pulse signal is periodically input to the gate of the MOSFET 232 (that is, the gate voltage is set to a negative voltage of the pulse waveform) to turn on the MOSFET 232. As a result, a current flows through the circuit means in which the sulfuration detection sensor A1 and the resistor 230 are connected in series. Then, when the sulfidation detector 20 is not sulfidized in the sulfidation detection sensor A1, and the resistance value of the sulfidation detector 20 is low, the voltage applied to one input terminal of the amplifier 234 is higher than the reference voltage. Therefore, no signal is output from the signal output terminal 238. On the other hand, when the sulfuration of the sulfide detector 20 progresses and the resistance value of the sulfide detector 20 increases, the voltage applied to one input terminal of the amplifier 234 becomes higher than the reference voltage, and a signal is output from the signal output terminal 238. Is done. Even when the sulfide detector 20 is disconnected, the voltage applied to one input terminal of the amplifier 234 is naturally higher than the reference voltage, and a signal is output from the signal output terminal 238. That is, the sulfide value is detected by setting the voltage value at the input end (+ side input end) of the amplifier 234 when the resistance value of the sulfide detector 20 reaches the sulfide detection level (see FIG. 3) as the reference voltage value. It can be detected that the resistance value of the body 20 has reached the sulfide detection level. Note that a signal is output from the signal output terminal 238 even when the sulfide detector 20 is disconnected. In other words, the circuit configured by the amplifier 234, the reference voltage source 236, and the signal output terminal 238 indicates that “a voltage detected between the pair of electrodes exceeds a predetermined value, It functions as “determination means for determining the degree of sulfidation”.

  In the sulfidation detection circuit W3 configured as described above, a pulse signal is input to the MOSFET 232 to operate the MOSFET 232, and current is passed through the sulfidation detection sensor A1 for the time during which the pulse signal is input. Therefore, power consumption can be reduced. it can. In particular, since the sulfide detection body 20 in the sulfide detection sensor A1 is mainly composed of silver and has a low resistance value, in order to detect a change in the resistance value of the sulfide detection body 20, a voltage detected by flowing a high value current is used. It is necessary to detect the change with high sensitivity. Further, since the sulfidation of the sulfidation detector 20 proceeds after a long period of several years, when the detection is performed by continuously supplying a current to the sulfidation detection circuit, Although the current consumption increases, the power consumption can be reduced by periodically operating the circuit by inputting a pulse signal as in the sulfide detection circuit W3. Further, since the amplifier 234 is provided, the output signal can be sufficiently detected even when the difference from the reference voltage is small.

  Also in the sulfuration detection circuits W1 and W2, it is preferable to reduce the current consumption by causing the current to periodically flow and operate the circuit, rather than constantly flowing a current to the circuit.

  In the sulfuration detection sensor A1, the sulfuration detector 20 has been described as having a rectangular shape in plan view. However, by forming the sulfuration detector 20 in a meandering shape, the width of the current path can be reduced and the current path can be reduced. It can be said that the predetermined voltage can be obtained with a small value of current by increasing the resistance of the sulfide detector 20 and increasing the resistance value thereof.

  Further, the sulfuration detection circuit W4 shown in FIG. 6 includes a sulfuration detection sensor A1, an LED 250, a light receiving unit 252, a light amount detection unit 254, and a determination unit 256. In this sulfuration detection circuit W4, when light is emitted obliquely from above with respect to the upper surface of the sulfurization detection sensor A1, the light passes through the transparent protective film 40 and is reflected by the upper surface of the sulfurization detector 20, and again. The light passes through the protective film 40 and is released to the outside. The amount of light emitted from the LED 250 is constant. The light emitted to the outside is received by the light receiving unit 252 and the light amount detection unit 254 detects the light amount of the received light. Then, the determination unit 256 determines that the sulfurization detector 20 has reached a predetermined sulfurization detection level when the detected light amount is equal to or less than a predetermined threshold value, and notifies the user by a warning light or warning sound (not shown). Warning.

  That is, as described above, the sulfuration detector 20 changes in the order of light brown, purple, gray, and black as the sulfurization progresses, and the amount of reflected light decreases as the sulfuration progresses. By detecting it, the degree of sulfidation can be detected.

  In the sulfuration detection circuits W1 to W4, it is necessary to set the sulfuration detection level so that it can be detected before the reliability of the operation of the other electronic components is lowered.

  Next, the sulfidation detection sensor A2 of the second embodiment has substantially the same configuration as the sulfidation detection sensor A1 of the first embodiment, but the protective film is a protective film that is permeable to sulfide gas and a protective film that is not permeable to sulfide gas. The point which was comprised by differs.

  That is, the sulfuration detection sensor A2 is configured as shown in FIG. 7, and includes the insulating substrate 10, the sulfuration detector 20, the lower surface electrode 22, the side surface electrode 24, the plating 26, and the protective film 40. The protective film 40 includes a protective film 42, a protective film 44, and a protective film 46. The protective films 42, 44, and 46 are formed on the upper surface of the sulfide detector 20 between the pair of electrodes in the inter-electrode direction. The protective film 42, the protective film 44, and the protective film 46 include the sulfide detector. 20 covers the entire region of the region exposed from the electrode portion (region excluding both sides in the inter-electrode direction).

  Here, the protective film 42 (sulfide gas impermeable protective film) is formed in contact with one (X2 side) plating 26 on the upper surface of the sulfide detector 20, and has a substantially square shape in plan view. Yes. That is, the arrangement position of the protective film 42 will be described in more detail. In the width direction (Y1-Y2 direction), the protective film 42 is formed wider than the width of the sulfide detector 20 and slightly smaller than the width of the insulating substrate 10. In addition, the sulfide detector 20 is covered in contact with the sulfide detector 20 in the width direction. A portion of the protective film 42 that protrudes from the sulfide detector 20 in the Y1-Y2 direction is in contact with the upper surface of the insulating substrate 10.

  The protective film 44 (sulfide gas impermeable protective film) is formed in contact with the other (X1 side) plating 26 on the upper surface of the sulfide detector 20, and has a substantially rectangular shape in plan view. . That is, the arrangement position of the protective film 44 will be described in more detail. In the width direction (Y1-Y2 direction), the protective film 44 is formed wider than the width of the sulfide detector 20 and slightly smaller than the width of the insulating substrate 10. In addition, the sulfide detector 20 is covered in contact with the sulfide detector 20 in the width direction. The portion of the protective film 44 that protrudes from the sulfide detector 20 in the Y1-Y2 direction is in contact with the upper surface of the insulating substrate 10. The shape and size of the protective film 44 in plan view are the same as those of the protective film 42.

  The protective film 42 and the protective film 44 are transparent sulfide gas non-permeable protective films and are formed of a material that does not transmit the sulfide gas. Examples of the material that does not transmit sulfur gas include glass, polyimide, polyester, nylon, epoxy, and acrylic. By using these for the protective film, the region covered with the protective films 42 and 44 in the sulfuration detector 20 is not sulfided or the degree of sulfuration is very small. In addition, when metal powder (copper powder or silver powder) that is easily sulfided by the sulfur gas is mixed with the protective films 42 and 44, the sulfur gas is adsorbed to the metal powder, so that the non-permeability of the sulfur gas is further increased.

  Further, the protective film 46 (sulfide gas permeable protective film) is provided at a position between the protective film 42 and the protective film 44, and has a substantially square shape in plan view. That is, the arrangement position of the protective film 46 will be described in more detail. In the width direction (Y1-Y2 direction), the protective film 46 is formed wider than the width of the sulfide detector 20 and slightly smaller than the width of the insulating substrate 10. In addition, the sulfide detector 20 is covered in contact with the sulfide detector 20 in the width direction. The portion of the protective film 46 that protrudes from the sulfide detector 20 in the Y1-Y2 direction is in contact with the upper surface of the insulating substrate 10. The ends of the protective film 46 in the inter-electrode direction are in contact with the protective films 42 and 44.

  Like the protective film 40 in the first embodiment, the protective film 46 has a sulfide gas permeability and is formed transparently. As a material constituting the protective film 46, silicon resin or fluororesin (for example, FEP: tetrafluoroethylene-6-fluoropropylene copolymer resin).

  As described above, all of the protective film 40 (that is, the protective films 42, 44, and 46) are formed to be transparent so that the upper surface of the sulfide detector 20 is visible, and a part of the protective film 40 (that is, the protective film 40). The membrane 46) is formed of a material having permeability to sulfide gas so that the sulfide gas can contact the sulfide detector 20. Note that only the protective film 46 in the protective film 40 may be transparent.

  Since the configuration other than the protective film 40 in the sulfidation detection sensor A2 of the present embodiment is the same as that of the sulfidation detection sensor A1 of the first embodiment, detailed description thereof is omitted.

  The use state and operation of the sulfurization detection sensor A2 having the above-described configuration are the same as those of the sulfurization detection sensor A1 of the first embodiment. That is, the sulfuration detection sensor A2 is used by being mounted on a printed circuit board, and by visually monitoring the color of the sulfurization detector 20 (particularly, the color of the region covered with the protective film 46 in the sulfide detector 20), The degree of sulfidation can be detected by visual observation, and furthermore, sulfidation can be detected by the sulfidation detection circuits W1 to W4.

  Further, in the sulfidation detection sensor A2 of this embodiment, since the upper surface of the sulfidation detector 20 is covered with the sulfidation gas permeable protective film 46 and the sulfidation gas non-permeable protective films 42 and 44, the sulfidation detector 20 is sulfurized. The degree of sulfidation can be determined by comparing and comparing colors of the portion (region covered by the protective film 46) and the non-sulfurized region (region covered by the protective films 42 and 44) and comparing the colors. It can be judged accurately. In other words, the part that is sulfided changes in color from silver to light brown, purple, gray, and black, but the part that is not sulfided remains the original silver color. Visual confirmation can be performed accurately. In particular, since the sulfuration detection sensor A2 used for a long period of time cannot be discolored even in the electrode portion, it is possible to accurately visually check by providing a non-discolored portion adjacent to the comparison object.

  Further, when attention is paid to the boundary region between the protective film 46 and the protective film 42 and the boundary region between the protective film 46 and the protective film 44, since the region covered with the protective films 42 and 44 in the sulfide detector 20 does not transmit sulfide gas. Although not done, it enters in the lateral direction from the boundary with the region covered with the protective film 46 and gradually sulfidizes the sulfide detector 20 inside, and changes its color to black. Since the progress of sulfidation in the lateral direction is slow, the degree of sulfidation over a long period of time can be observed by observing the discolored area (area shown by hatching in FIG. 8) width H1. Even if the region of the protective film 46 in the sulfide detector 20 is sulfided and disconnected, the lateral progress continues, so that it is possible to know how much the device has been exposed to the sulfide gas.

  Further, in the case of using the sulfidation detection circuit W4 as shown in FIG. 6, a light receiving unit (first light receiving means) that receives reflected light from the region covered with the protective film 46 in the sulfidation detector 20, and the protective film 42 A light receiving portion (second light receiving means) for receiving reflected light from the region covered with or the region covered with the protective film 44, and a light amount detecting portion (first light amount) for detecting the light amount of the received light respectively. By providing a detection unit and a second light amount detection unit) and comparing the detected two light amounts (for example, calculating the difference between the two light amounts and comparing the difference value with a predetermined threshold value) You may make it provide the determination part (determination means) which determines the degree of sulfuration. That is, the reflected light from the sulfided region in the sulfide detector 20 is compared with the reflected light from the non-sulfurized region. As a result, the degree of sulfidation can be accurately detected by relatively comparing the sulfided region and the non-sulfurized region in the sulfide detector 20. The reflected light from the non-sulfurized region is irradiated with light to each of the protective film 42 and the protective film 44, and each reflected light is received to calculate the amount of light, and the average value of the amount of light is sulfided. It may be the amount of light in the area that is not.

  Next, the sulfuration detection sensor A3 of the third embodiment has substantially the same configuration as the sulfurization detection sensor A1 of the first embodiment, except that a protective film is not provided.

  That is, the sulfuration detection sensor A3 is configured as shown in FIG. 9, and includes the insulating substrate 10, the sulfuration detector 20, the lower surface electrode 22, the side electrode 24, and the plating 26.

  Since the configuration of each of the above-described parts constituting the sulfurization detection sensor A3 is the same as that of each part in the first embodiment, detailed description thereof is omitted.

  The use state and operation of the sulfurization detection sensor A3 having the above configuration are the same as those of the sulfurization detection sensor A1 of the first embodiment. That is, the sulfidation detection sensor A3 is used by being mounted on a printed circuit board, and is visually sulfidized by monitoring the color of the sulfidation detector 20 (particularly the color of the sulfidation detector 20 in the region of the protective film 46). In addition, the sulfuration detection circuits W1 to W4 can detect sulfurization.

  In the present embodiment, since the sulfuration detector 20 is exposed to the outside, the sensitivity to sulfuration is good and sulfurization can be detected with high sensitivity.

  If the sulfuration detector 20 is exposed as described above, the sensitivity to sulfuration is good, but solder or flux comes into contact with the sulfuration detector 20 and sulfurization cannot be detected, or it is detected by oil, humidity, dirt, etc. of the hand. Although there is a disadvantage that the period changes, if the surface of the sulfide detector 20 is washed after mounting or is coated by spraying a sulfide gas permeable material, a protective film is provided as in Example 1. The operation equivalent to the case can be expected, and it becomes sufficiently practical.

  As a manufacturing method of the sulfidation detection sensor A3 of the present embodiment, a protective film is formed with a soluble material that can be boiled or dissolved in a solvent, and after plating in the same manner as the chip component manufacturing method, the meltable protective film is dissolved and removed. .

  A specific manufacturing method will be described with reference to FIG. 10. First, an alumina substrate (substrate body) in which primary slits J1 and secondary slits J2 are provided in advance (this alumina substrate is an insulating material for a plurality of sulfide detection sensors). A sulfide detection body 20G is formed in a band shape on the front side surface of the large-sized substrate having at least the size of the substrate. This sulfuration detector 20G serves as a sulfide detector for a plurality of sulfide detection sensors. For example, a sulfide detector paste is printed and then dried and fired (FIG. 10A, sulfide detector forming step). There are also a method by vapor deposition and a method by vapor deposition and silver plating.

  And as shown in FIG.10 (b), the protective film 40 is formed (protective film formation process). This protective film is formed of a soluble material that can be boiled or dissolved in a solvent.

Thereafter, the alumina substrate is primarily divided along the primary slit J1 (FIG. 10C, primary dividing step), and then the side electrode 24G is formed on the strip-shaped substrate formed by the primary division. In forming the side electrode, the side electrode paste is printed and then dried and cured (FIG. 10D, side electrode forming step). As the side electrode paste, a side electrode paste containing silver and a resin is used. The side electrode may be formed by vapor deposition of nickel, chromium, gold or the like.
Then, secondary division is performed along the secondary slit J2 (secondary division step). Then, plating is performed (plating process) to form an element body of the sulfide detection sensor A3.

  When the element body of the sulfidation detection sensor A3 is formed, the protective film is removed from the element body of the sulfidation detection sensor A3. That is, when the protective film 40 is a soluble material that dissolves by boiling, the protective film 40 is removed by boiling, and when the protective film 40 is a soluble material that dissolves by a solvent, the protective film 40 is removed using a solvent. (Protective film dissolution step). As described above, the sulfide detection sensor A3 is formed.

  Further, as another example of the sulfurization detection sensor A3 of the third embodiment, as shown in FIG. 11, a sulfurization gas non-permeable property is provided on both sides of the exposed region of the sulfide detection body 20 in the sulfurization detection sensor A3. It is good also as a structure which provides the protective films 42 and 44 which have. Examples of the material of the protective films 42 and 44 include glass, polyimide, polyester, nylon, epoxy, acrylic, and the like, similar to the protective films 42 and 44 of the second embodiment.

  By adopting such a configuration, it is possible to prevent the solder from getting over the electrode portions on both sides and coming into contact with the sulfide detector 20 when the sulfide detection sensor A3 ′ is mounted on the printed circuit board by soldering. .

  Further, if the protective films 42 and 44 are made of a transparent material, the exposed region of the sulfurization detector 20 (the region between the protective film 42 and the protective film 44) and the protective film 42 are the same as in the second embodiment. , 44 and comparing and observing the color, the degree of sulfuration can be accurately determined.

  Next, the sulfidation detection sensor A4 of the fourth embodiment has substantially the same configuration as the sulfidation detection sensor A2 of the second embodiment. However, in the sulfidation detection sensor A2 of the second embodiment, a sulfide gas permeable protective film and In contrast to the arrangement of the sulfide gas impermeable protective film in the direction between the electrodes, in this embodiment, the sulfide gas permeable protective film and the sulfide gas impermeable protective film are defined as the interelectrode direction. The difference is that they are arranged in a perpendicular direction.

  That is, the sulfuration detection sensor A4 is configured as shown in FIG. 12, and includes the insulating substrate 10, the sulfuration detector 20, the lower surface electrode 22, the side electrode 24, the plating 26, and the protective film 40. The protective film 40 includes a protective film 48 and a protective film 50. The protective films 48 and 50 are formed on the upper surface of the sulfide detector 20 between the pair of electrode portions so as to be aligned in a direction perpendicular to the inter-electrode direction. That is, both of the protective films 48 and 50 are formed in contact with the pair of platings 26 on both sides, and among the areas exposed from the electrode portions in the sulfide detector 20, the half area on the Y2 side is covered with the protective film 48. A half region on the Y1 side is covered with a protective film 50. That is, the width in the direction perpendicular to the interelectrode direction of the region covered with the protective film 48 in the sulfide detector 20 and the width in the direction perpendicular to the interelectrode direction in the region covered with the protective film 50 in the sulfide detector 20. Are formed identically.

  The protective film 48 is a transparent sulfide gas non-permeable protective film, and is formed of a material that does not transmit sulfide gas. Examples of the material that does not transmit the sulfiding gas include glass, polyimide, polyester, nylon, epoxy, acrylic, and the like, similar to the protective films 42 and 44 of the second embodiment. By using these for the protective film, the region covered with the protective film 48 in the sulfide detector 20 is not sulfided or the degree of sulfuration is very small. Further, when metal powder (copper powder or silver powder) that is easily sulfidized is mixed with the protective film 48, the sulfide gas is adsorbed to the metal powder, so that the impermeability of the sulfide gas is further increased.

  Further, the protective film 50 is, like the protective film 40 in the first embodiment and the protective film 46 in the second embodiment, having sulfide gas permeability and being formed transparently. And silicon resin and fluorine resin (for example, FEP: tetrafluoroethylene-6fluoropropylene copolymer resin).

  In addition, when the region covered with the protective film 50 in the sulfide detector 20 is sulfided, sulfidation proceeds in the thickness direction, and sulfidation also proceeds in the region covered with the protective film 48. The width in the direction perpendicular to the interelectrode direction (the width in the Y1-Y2 direction) is such that the region covered with the protective film 48 is disconnected even if the region covered with the protective film 50 is sulfided in the thickness direction and disconnected. The width is not set.

  As described above, all of the protective film 40 (that is, the protective films 48 and 50) are formed to be transparent so that the upper surface of the sulfide detector 20 is visible, and a part of the protective film 40 (that is, the protective film 50). ) Is formed of a material having permeability to sulfur gas so that the sulfur gas can contact the sulfur detector 20. Note that only the protective film 50 in the protective film 40 may be transparent.

  The use state and operation of the sulfurization detection sensor A4 having the above-described configuration are the same as those of the sulfurization detection sensor A1 of the first embodiment. That is, the sulfuration detection sensor A4 is used by being mounted on a printed circuit board, and by visually monitoring the color of the sulfurization detector 20 (particularly, the color of the region covered with the protective film 50 in the sulfide detector 20), The degree of sulfidation can be detected by visual observation, and furthermore, sulfidation can be detected by the sulfidation detection circuits W1 to W4.

  Further, in the sulfidation detection sensor A4 of the present embodiment, since the upper surface of the sulfidation detector 20 is covered with the sulfide gas permeable protective film 50 and the sulfide gas non-permeable protective film 48, it is sulfided. The degree of sulfidation is accurately determined by comparing the portion (region covered with the protective film 50) and the non-sulfurized region (region covered with the protective film 48) and comparing the colors. be able to. In other words, the part that is sulfided changes in color from silver to light brown, purple, gray, and black, but the part that is not sulfided remains the original silver color. Visual confirmation can be performed accurately. In particular, since the sulfuration detection sensor A4 used for a long period of time cannot be discolored even in the electrode portion, the portion that does not change color is provided adjacently as a comparison object, so that accurate visual confirmation is possible.

  Further, when attention is paid to the boundary region between the protective film 48 and the protective film 50, the region covered with the protective film 48 in the sulfide detector 20 is not sulfided because the sulfide gas does not permeate, but the region covered with the protective film 50 is not. Entering in the lateral direction from the boundary, the internal sulfide detector 20 is gradually sulfided and discolored to black. Since the progress of the sulfidation in the lateral direction is slow, the degree of sulfidation over a long period of time can be observed by observing the discolored region (the region shown by hatching in FIG. 13) width H2.

  Further, as described above, the width in the direction perpendicular to the interelectrode direction of the sulfurization detector 20 (the width in the Y1-Y2 direction) is that the region covered with the protective film 50 is sulfided in the thickness direction and disconnected. However, since the region covered with the protective film 48 is formed with a width that does not break, even when the region covered with the protective film 50 is broken due to sulfidation, the conductive state is ensured by the region covered with the protective film 48. Thus, the conduction width of the region covered with the protective film 48 is gradually reduced. Therefore, even if the region covered with the protective film 50 is disconnected due to sulfuration, the resistance value gradually increases in a state where the conduction state is ensured, so that the resistance value is detected and mounted on the printed circuit board. It is possible to predict the lifetime of other electronic components that have been used. In particular, since the progress of lateral sulfidation is slow, it is suitable for detecting sulfidation over a long period of time. Since the sulfuration detection sensor A4 is suitable for long-term sulfurization detection, members constituting the electrode portion of the sulfurization detection sensor A4, particularly the lower surface electrode 22 and the side electrode 24, are mixed with 20% or more of palladium. It is preferable that the electrode portion is made of a material that is not sulfided by forming it with silver, nickel, nichrome, gold, or the like.

  Further, in the case of using the sulfidation detection circuit W4 as shown in FIG. 6, a light receiving unit (first light receiving means) for receiving reflected light from the region covered with the protective film 50 in the sulfidation detector 20, and the protective film 48 A light receiving unit (second light receiving unit) for receiving reflected light from the region covered with the light, and a light amount detecting unit (first light amount detecting unit and second light amount detecting unit) for detecting the light amount of the received light, respectively. And determining the degree of sulfidation by comparing the two detected light quantities (for example, calculating the difference between the two light quantities and comparing the difference value with a predetermined threshold value) (Determination means) may be provided. That is, the reflected light from the sulfided region in the sulfide detector 20 is compared with the reflected light from the non-sulfurized region.

  In the description of each of the above embodiments, the material constituting the sulfide detector 20 has been described as a material mainly composed of silver. However, copper or a material mainly composed of copper may be used. Since copper becomes copper sulfide and becomes an insulator when it is sulfided, it can be used as a sulfide detector.

  In each of the above embodiments, the sulfide detector 20 has a substantially square shape and a linear wide pattern. However, the sulfide detector 20 can be reciprocated or meandered many times on the insulating substrate between the electrode portions. By making a spiral and thin and long pattern, there is an effect that it is easy to detect using a change in resistance value of sulfide. In other words, the sulfide detector 20 is mainly made of silver or copper and originally has a low resistance value. Therefore, it is necessary to pass a large current to detect a change in the resistance value. However, the sulfide detector 20 has a thin and long pattern as described above. As a result, the initial resistance value increases, the resistance value change when sulfidized increases, and the current required for detection can be reduced, so that the power consumption can be reduced. Since sulfiding generally proceeds in the depth direction of the sulfidation detector, even if the pattern is thin and long, the possibility of sulfidation breakage in the width direction of the pattern is low, and there is no problem in detecting the resistance value even if the pattern is thin and long.

  In each of the above-described embodiments, the protective films 40, 42, 44, 46, 48, and 50 are described as being transparent, but may be translucent. In this case, the translucent transparency may be such that the upper surface (in particular, the state of the color of the upper surface) of the sulfide detector 20 can be visually observed.

  Even if the protective films 40, 42, 44, 46, 48, 50 are not transparent or translucent but opaque and the configuration such as the color of the surface of the sulfide detector 20 cannot be visually observed, the sulfide detectors W <b> 1 to W <b> 1. It is possible to detect the cumulative degree of sulfidation by W4. In particular, in the case of Example 4, even if the protective films 48 and 50 constituting the protective film 40 are opaque, the sulfide gas permeable protective film is covered with a width in the direction perpendicular to the interelectrode direction of the sulfide detector. Even if the formed region is sulfided and disconnected in the thickness direction, the region covered with the sulfide gas non-permeable protective film is covered with the sulfide gas permeable protective film by forming the width so as not to disconnect. Even when the region is disconnected due to sulfidation, the conduction state is ensured by the region covered with the sulfide gas impermeable protective film, and the effect of being suitable for detection of sulfidation over a long period of time can be obtained.

It is a figure which shows the structure of the sulfide detection sensor based on Example 1 of this invention, (a) is PP sectional drawing in (b), (b) is a top view. It is a circuit diagram which shows the example of a sulfide detection circuit. It is a graph which shows the relationship between elapsed time and resistance value. It is a circuit diagram which shows the other example of a sulfide detection circuit. It is a circuit diagram which shows the other example of a sulfide detection circuit. It is a circuit diagram which shows the other example of a sulfide detection circuit. It is a figure which shows the structure of the sulfide detection sensor based on Example 2 of this invention, (a) is QQ sectional drawing in (b), (b) is a top view. It is explanatory drawing which shows the state of progress of the sulfidation of the sulfidation detection sensor of Example 2. It is a figure which shows the structure of the sulfide detection sensor based on Example 3 of this invention, (a) is RR sectional drawing in (b), (b) is a top view. It is explanatory drawing which shows the manufacturing process of the sulfide detection sensor of Example 3. It is a figure which shows the structure of the other example of the sulfide detection sensor based on Example 3 of this invention, (a) is SS sectional drawing in (b), (b) is a top view. It is a figure which shows the structure of the sulfide detection sensor based on Example 4 of this invention, (a) shows the TT sectional drawing and UU sectional drawing in (b), (b) is a top view. It is explanatory drawing which shows the state of progress of the sulfidation of the sulfidation detection sensor of Example 4. It is sectional drawing which shows the structure of the conventional chip resistor.

Explanation of symbols

A1, A2, A3, A3 ′, A4 Sulfide detection sensor 10 Insulating substrate 20 Sulfide detector 22 Bottom electrode 24 Side electrode 26 Plating 40, 42, 44, 46, 48, 50 Protective film W1, W2, W3, W4 Sulfide detection Circuit 210, 220, 224, 230 Resistance 212, 250 LED
222, 232 MOSFET
234 Amplifier 252 Light receiving unit 254 Light amount detection unit 256 Determination unit

Claims (16)

An insulating substrate;
A sulfide detector formed on the upper surface of the insulating substrate and containing as a main material a metal that is sulfided by a sulfide gas;
An electrode part formed on both ends of the insulating substrate and connected to the sulfide detector;
This is a protective film that covers the uncovered area that is not covered by the electrode part of the sulfur detector, and the upper surface of the sulfide detector is made transparent or semi-transparent so that it can be seen, and has a sulfur gas permeability. And a sulfide gas permeable protective film that covers a part of the region of the sulfide detector that is not covered with the electrode portion, and the upper surface of the sulfide detector is formed to be transparent or translucent so that it can be visually observed. A sulfide gas permeable protective film and a sulfide gas are formed of a gas non-permeable material, and are formed of a sulfide gas non-permeable protective film that covers a part of a region of the sulfur detector that is not covered with the electrode portion. A non-permeable protective film is arranged side by side in the direction between the electrodes, and the sulfide gas permeable protective film and the sulfide gas non-permeable protective film cover a region of the sulfide detector that is not covered with the electrode portion. And Mamorumaku,
A sulfuration detection sensor comprising: An insulating substrate;
A sulfide detector formed on the upper surface of the insulating substrate and containing as a main material a metal that is sulfided by a sulfide gas;
An electrode part formed on both ends of the insulating substrate and connected to the sulfide detector;
The region of the sulfur detector that is not covered with the electrode is covered, and at least a part of the upper surface of the sulfur detector is formed to be transparent or translucent so that the sulfide gas can contact the sulfide detector. A protective film formed of a material having sulfur gas permeability,
A sulfuration detection sensor comprising: An insulating substrate;
A sulfide detector formed on the upper surface of the insulating substrate and containing a metal that is sulfided by a sulfide gas;
An electrode part formed on both ends of the insulating substrate and connected to the sulfide detector;
Have
A sulfuration detection sensor, wherein a region of the sulfuration detector that is not covered with an electrode portion is exposed to the outside. A sulfide gas non-permeable protective film made of a material having non-sulfide gas permeability is formed in the end region on both sides in the inter-electrode direction of the region exposed from the electrode part in the sulfide detector, The sulfide detection sensor according to claim 3, wherein a region between the pair of sulfide gas impermeable protective films not covered with the sulfide gas impermeable protective film is exposed to the outside. The sulfide detection sensor according to claim 4, wherein the sulfide gas impermeable protective film is formed to be transparent or translucent so that the upper surface of the sulfide detector is visible. An insulating substrate;
A sulfide detector formed on the upper surface of the insulating substrate and containing as a main material a metal that is sulfided by a sulfide gas;
An electrode part formed on both ends of the insulating substrate and connected to the sulfide detector;
This is a protective film that covers the uncovered area that is not covered by the electrode part in the sulfur detector, and is formed from a material that is permeable to sulfide gas, and part of the area that is not covered by the electrode part in the sulfide detector And a sulfide gas impermeable protective film that is formed of a material that is impermeable to sulfide gas and that covers a part of the area of the sulfide detector that is not covered with the electrode portion. The sulfurized gas permeable protective film and the sulfurized gas non-permeable protective film are arranged in a direction perpendicular to the inter-electrode direction, the sulfurized gas permeable protective film and the sulfurized gas non-permeable protective film; And a protective film that covers a region of the sulfur detector that is not covered with the electrode part,
A sulfuration detection sensor comprising: The sulfurized gas permeable protective film and the sulfurized gas non-permeable protective film constituting the protective film are formed transparent or translucent so that the upper surface of the sulfide detector is visible. Sulfidation detection sensor. 8. The sulfide detection sensor according to claim 1, wherein the metal sulfided by the sulfide gas in the sulfur detector is silver or copper. The sulfurization detection sensor according to claim 1, 2, 3, 4, 5, 6, 7, or 8, wherein the sulfide gas permeable protective film is silicon resin or fluororesin. The sulfurized gas impermeable protective film is formed of any one of glass, polyimide, polyester, nylon, epoxy, and acryl, or 1 or 2 or 3 or 4 or 5 or 6 or 7 or The sulfide detection sensor according to 8 or 9. Sulfurization detection sensor according to claim 1 or 2 or 3 or 4 or 5 or 6 or 7 or 8 or 9 or 10;
Circuit means in which a sulfide detection sensor and a resistor are connected in series;
Voltage applying means for applying a voltage to both ends of the circuit means and causing a current to flow between the pair of electrode portions;
A determination means for determining the degree of sulfidation of the sulfidation detector of the sulfidation detection sensor by detecting that the voltage between the pair of electrode portions exceeds a predetermined value;
A sulfide detection circuit comprising: 12. The sulfide detection circuit according to claim 11, wherein the voltage applying means applies a voltage at a predetermined interval. 13. The sulfide according to claim 11, wherein the determination unit compares a voltage value between the pair of electrode portions with a predetermined reference voltage value, amplifies the difference, and outputs the amplified difference. Detection circuit. Sulfurization detection sensor according to claim 1 or 2 or 3 or 4 or 5 or 7;
A light irradiating means for irradiating light to the sulfur detector of the sulfur detection sensor;
A light receiving means for receiving reflected light from the sulfide detector of the sulfide detection sensor;
A light amount detecting means for detecting a light amount of light received by the light receiving means;
Determining means for determining the degree of sulfidation of the sulfidation detector of the sulfidation detection sensor by detecting that the light amount detected by the light amount detection means exceeds a predetermined value;
A sulfide detection circuit comprising: Sulfurization detection sensor according to claim 1 or 7,
A light irradiating means for irradiating light to the sulfur detector of the sulfur detection sensor;
A light receiving means for receiving reflected light from a sulfide detection body of a sulfuration detection sensor, a first light receiving means for receiving reflected light from a region covered with a sulfide gas permeable protective film or an exposed region; and a sulfurized gas A light receiving means having a second light receiving means for receiving the reflected light of the region covered with the non-permeable protective film;
First light amount detecting means for detecting the amount of light received by the first light receiving means;
Second light quantity detection means for detecting the light quantity of light received by the second light receiving means;
Determining means for comparing the light quantity detected by the first light quantity detection means and the light quantity detected by the second light quantity detection means to determine the degree of sulfidation of the sulfidation detector of the sulfidation detection sensor;
A sulfide detection circuit comprising: It is a manufacturing method of the sulfuration detection sensor according to claim 3,
A substrate element that is an element of an insulating substrate in a sulfide detection sensor, and is a metal that is sulfided by a sulfide gas in the region of each sulfide detection sensor on the upper surface of the substrate element having at least the size of the insulating substrate. A sulfide detector forming step of forming a sulfide detector containing as a main material,
A protective film forming step for forming a protective film that covers a region not covered with the side electrode and plating in the sulfur detector, and a protective film forming step for forming a protective film with a soluble material;
A primary dividing step of dividing the substrate body along a boundary line perpendicular to the inter-electrode direction to form a plurality of strip-shaped substrates;
A side electrode forming step of forming a side electrode so as to be connected to the sulfide detector in a side electrode forming step of forming the side electrode in a substantially U-shaped cross section with respect to the strip-shaped substrate;
A secondary division step of dividing the strip-shaped substrate along the boundary line in the inter-electrode direction;
A plating process for forming plating on the exposed region of the sulfur detector and the side electrode;
By dissolving the protective film, the side electrode in the sulfide detector and the region exposed from the plating are exposed to the outside, and a protective film dissolving step,
A method for producing a sulfide detection sensor, comprising:

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