JPWO2012017532A1 - Semiconductor sensor - Google Patents

Abstract

The present invention is a semiconductor sensor in which an electric circuit made of a metal thin film is formed on the surface of a semiconductor element, and is arranged opposite to each other on the surface of the semiconductor element as a part of the electric circuit and is applied with different potentials. And a dew condensation detection circuit configured to determine whether or not dew condensation has occurred on a surface of the semiconductor element based on a potential difference generated between the two electric conductor portions.

Description

  The present invention relates to a semiconductor sensor, and more particularly to a semiconductor sensor in which an electric circuit made of a metal thin film is formed on the surface of a semiconductor element.

  2. Description of the Related Art Conventionally, semiconductor sensors used for automobile engine control, barometers, and the like are known (see, for example, Patent Documents 1 to 4). The semiconductor sensor described in Patent Document 1 includes a substrate having a diaphragm portion as a semiconductor sensor, and performs a failure diagnosis of the diaphragm portion based on a voltage change between the conductor and the diaphragm portion. The semiconductor sensor described in Patent Document 2 includes a bridge circuit made of a strain gauge as a semiconductor sensor, and performs a failure diagnosis that detects a disconnection of a wiring between the bridge circuit and a measuring instrument.

  In addition, the semiconductor sensor described in Patent Document 3 connects a wire to a wire bonding pad of a semiconductor element, detects whether or not a current flows from the wire to the wire bonding pad, and causes a failure due to the life of the semiconductor element in advance. Predict the failure to be detected. The semiconductor sensor described in Patent Document 4 is provided with a failure prediction element that has a deterioration progress faster than a normal element on a semiconductor substrate, and detects the degree of deterioration of the deterioration prediction element to predict the occurrence of a deterioration failure. I do.

JP 2004-150944 A JP 2005-037318 A JP 2008-004728 A JP 7-218595 A

  Incidentally, in a semiconductor sensor used for automobile engine control, a barometer, or the like, a semiconductor element is mounted in a housing. When moisture penetrates into the housing, condensation may occur on the surface of the semiconductor element as the temperature changes. If dew condensation occurs on the surface of the semiconductor element, electrolytic corrosion may occur in the electrode part and the electric conductor part, and electrical conduction may be interrupted. When electrical continuity is interrupted in a semiconductor element, the semiconductor element does not drive normally, and as a result, the semiconductor sensor does not operate normally until the semiconductor element is repaired or replaced. Therefore, in order to always maintain the normal driving of the semiconductor element, before the semiconductor element breaks down, specifically, before the semiconductor element shifts from a normal driving state to a non-driving state due to condensation. It is necessary to detect dew condensation generated on the surface of the semiconductor element. However, conventional semiconductor sensors (for example, the techniques of Patent Documents 1 to 4) cannot detect dew condensation generated on the surface of the semiconductor element.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a semiconductor sensor capable of detecting condensation occurring on the surface of a semiconductor element before the occurrence of a failure due to condensation of the semiconductor element. To do.

  The semiconductor sensor of the present invention is a semiconductor sensor in which an electric circuit made of a metal thin film is formed on the surface of a semiconductor element, and is disposed as opposed to each other on the surface of the semiconductor element as a part of the electric circuit. Two electrical conducting wire portions to which a potential is applied, and a dew condensation detection circuit that determines whether or not condensation has occurred on the surface of the semiconductor element based on a potential difference generated in the two electrical conducting wire portions.

  In the semiconductor sensor described above, the separation distance between the two electric conductor portions is smaller than the minimum distance of the distances between any two electrode portions or electric conductor portions of the electric circuit excluding the separation distance. Is preferably small.

  Moreover, in the above-described semiconductor sensor, the high potential electrical conductor portion to which a high potential is applied among the two electrical conductor portions is applied with the low potential of the two electrical conductor portions on the surface of the semiconductor element. It is preferable to arrange between the low-potential electric conductor part and the electrode part or other electric conductor part of the electric circuit.

  In the semiconductor sensor described above, it is preferable that the shape of the two electric conducting wire portions on the surface of the semiconductor element is a shape that easily collects condensed moisture.

  In the semiconductor sensor described above, a first resistor connected in parallel to one of the two electric conductor portions, and a first resistor connected to the one electric conductor portion and the first resistor. A first electrode connected to one end of the first resistor, a second resistor having one end connected to the other end of the one electrical conductor and the first resistor, and the other of the two electrical conductors A constant current is circulated between the second electrode portion connected to the electric conductor and the other end of the second resistor, and between the first electrode portion and the second electrode portion. And the dew detection circuit includes the first electrode in a situation where a constant current is circulated between the first electrode part and the second electrode part by the constant current circulation means. When the potential difference between the electrode portion and the second electrode portion is larger than the normal potential difference, It is preferable to determine the dew condensation occurs on the surface of the element.

  In the semiconductor sensor described above, a first electrode portion connected to one of the two electric conductor portions, a resistor connected at one end to the one electric conductor portion, and the two A second electrode part connected to the other electric conductor part of the electric conductor parts and connected to the other end of the resistor is fixed between the first electrode part and the second electrode part. A constant voltage application means for applying a voltage, and the dew condensation detection circuit is configured to apply a constant voltage between the first electrode portion and the second electrode portion by the constant voltage application means. It is preferable to determine that dew condensation has occurred on the surface of the semiconductor element when the potential difference generated between the two electric conductor portions does not reach the vicinity of the constant voltage.

  Moreover, in the above-described semiconductor sensor, it is preferable that each of the two electric conductor portions is mainly made of aluminum.

  Furthermore, in the above-described semiconductor sensor, it is preferable that the two electric conductor portions are disposed on the outer peripheral side of a diaphragm formed on the surface of the semiconductor element.

  ADVANTAGE OF THE INVENTION According to this invention, the dew condensation which generate | occur | produced on the semiconductor element surface before the failure generation resulting from the dew condensation of a semiconductor element is detectable.

1 is a top view of a semiconductor sensor according to a first embodiment of the present invention. It is a circuit block diagram of the failure prediction circuit in the semiconductor sensor which concerns on 1st Embodiment of this invention. It is a flowchart of an example of the control routine which a failure prediction circuit performs in the semiconductor sensor which concerns on 1st Embodiment of this invention. It is a top view of the semiconductor sensor which concerns on 2nd Embodiment of this invention. It is a flowchart of an example of the control routine which a failure prediction circuit performs in the semiconductor sensor which concerns on 2nd Embodiment of this invention. It is a top view of the semiconductor sensor which concerns on the modification of this invention. (A)-(g) is a partial top view which shows the shape of an electrically-conductive wire part in the semiconductor sensor which concerns on embodiment of this invention.

  A semiconductor sensor according to an embodiment of the present invention is a semiconductor sensor in which an electric circuit made of a metal thin film is formed on the surface of a semiconductor element, and is disposed to face each other on the surface of the semiconductor element as a part of the electric circuit. Two electrical conductor portions to which different potentials are applied, and a dew condensation detection circuit that determines whether or not condensation has occurred on the surface of the semiconductor element based on a potential difference generated in the two electrical conductor portions. It is a semiconductor sensor provided.

  In the present embodiment, an electric circuit made of a metal thin film formed on the surface of a semiconductor element has two electric circuits that are arranged opposite to each other on the surface of the semiconductor element and to which different potentials are applied. It has a conductor part. In such a structure, when the dew condensation caused by the temperature change proceeds between the two electrical conductor portions, the metal thin film (for example, aluminum) of the two opposing electrical conductor portions melts from the high potential side, and electrolytic corrosion occurs. Is generated, and the metal thin film on the high potential side is cut, whereby electrical conduction is interrupted. In the above structure, when the electrical continuity of the electrical conductor is maintained, the potential difference between the two electrical conductors is almost constant, but when the electrical continuity of the electrical conductor is interrupted, the electrical At the moment when the continuity is cut off, the potential difference between the two electrical conductors changes (the potential difference increases), and the potential difference between the two electrical conductors is different from that when the electrical continuity is maintained. It will be a thing. Therefore, in the present embodiment, whether or not dew condensation has occurred on the surface of the semiconductor element is determined based on a change in potential difference generated between the two electric conductor portions. Therefore, according to the present embodiment, it is possible to detect the dew condensation that has occurred on the surface of the semiconductor element before the occurrence of the failure due to the dew condensation on the semiconductor element.

  In the semiconductor sensor described above, the separation distance between the two electric conductor portions is smaller than the minimum distance of the distances between any two electrode portions or electric conductor portions of the electric circuit excluding the separation distance. Is preferably small.

  In this aspect, the separation distance between two electric conductor portions that are arranged opposite to each other on the surface of the semiconductor element and to which different electric potentials are applied is equal to any two electrode portions or electric conductor portions of the electric circuit. It is smaller than the minimum distance of the distance between them excluding the separation distance. For this reason, when condensation occurs on the surface of a semiconductor element, the part where moisture accompanying the condensation easily adheres, that is, the part where the electrolytic corrosion due to condensation occurs at the earliest timing is all of the electrode part and the electric conductor part on the semiconductor element. Among these combinations, it is considered that the two electric conductive wire portions are arranged opposite to each other on the surface of the semiconductor element and are applied with different potentials. Therefore, by having two electric conductor portions that are arranged opposite to each other on the surface of the semiconductor element and to which different electric potentials are applied, the electrolytic corrosion due to dew condensation on the two electric conductor portions at the earliest timing on the semiconductor element. Therefore, the dew condensation generated on the surface of the semiconductor element before the occurrence of the failure due to the dew condensation on the semiconductor element can be detected.

  Moreover, in the above-described semiconductor sensor, the high potential electrical conductor portion to which a high potential is applied among the two electrical conductor portions is applied with the low potential of the two electrical conductor portions on the surface of the semiconductor element. It is preferable to arrange between the low-potential electric conductor part and the electrode part or other electric conductor part of the electric circuit.

  In this aspect, the high-potential electrical conductor portion of the two electrical conductor portions that are arranged opposite to each other on the surface of the semiconductor element and to which different potentials are applied is the low-potential electrical conductor portion and the electrical circuit electrode portion or It arrange | positions between other electric conducting wire parts. In general, electrolytic corrosion due to condensation of a semiconductor element occurs on the high potential side. For this reason, even when the potential of the low-potential electrical lead portion is lower than the potential of the electrode portion or electrical lead portion other than the high-potential electrical lead portion, dew condensation occurs between the high-potential electrical lead portion and the low-potential electrical lead portion. Before moisture adheres, it is difficult for the condensed moisture to accumulate between the low-potential electrical lead portion and the electrode portion or electrical lead portion other than the high-potential electrical lead portion. Therefore, before detecting the dew condensation that has occurred on the surface of the semiconductor element, an electrode part or electric conductor other than the two electric conductor parts that are arranged opposite to each other on the surface of the semiconductor element and to which different potentials are applied. It is possible to avoid the occurrence of electrolytic corrosion due to condensation at the portion.

  In the semiconductor sensor described above, it is preferable that the shape of the two electric conducting wire portions on the surface of the semiconductor element is a shape that easily collects condensed moisture.

  In this aspect, the shape of the two electric conducting wire portions that are arranged opposite to each other on the surface of the semiconductor element and to which different potentials are applied is a shape that easily collects condensed moisture. For this reason, it becomes easy to detect the dew condensation generated on the surface of the semiconductor element before the occurrence of the failure due to the dew condensation of the semiconductor element.

  In the semiconductor sensor described above, a first resistor connected in parallel to one of the two electric conductor portions, and a first resistor connected to the one electric conductor portion and the first resistor. A first electrode connected to one end of the first resistor, a second resistor having one end connected to the other end of the one electrical conductor and the first resistor, and the other of the two electrical conductors A constant current is circulated between the second electrode portion connected to the electric conductor and the other end of the second resistor, and between the first electrode portion and the second electrode portion. And the dew detection circuit includes the first electrode in a situation where a constant current is circulated between the first electrode part and the second electrode part by the constant current circulation means. When the potential difference between the electrode portion and the second electrode portion is larger than the normal potential difference, It is preferable to determine the dew condensation occurs on the surface of the element.

  In this aspect, when a constant current flows between the first electrode portion and the second electrode portion, when the electrical continuity of one electric conductor portion is maintained, the flowing current is mainly one of them. Therefore, the potential difference between the first electrode portion and the second electrode portion is relatively small. On the other hand, when the electrical continuity of one of the electrical conducting wire portions is interrupted, the flowing current mainly flows through the first resistance side, so that the potential difference between the first electrode portion and the second electrode portion is relatively small. growing. Therefore, if it is determined that condensation has occurred on the surface of the semiconductor element when the potential difference between the first electrode portion and the second electrode portion is relatively large, the presence or absence of the condensation can be accurately detected. It becomes easy to do.

  In the semiconductor sensor described above, a first electrode portion connected to one of the two electric conductor portions, a resistor connected at one end to the one electric conductor portion, and the two A second electrode part connected to the other electric conductor part of the electric conductor parts and connected to the other end of the resistor is fixed between the first electrode part and the second electrode part. A constant voltage application means for applying a voltage, and the dew condensation detection circuit is configured to apply a constant voltage between the first electrode portion and the second electrode portion by the constant voltage application means. It is preferable to determine that dew condensation has occurred on the surface of the semiconductor element when the potential difference generated between the two electric conductor portions does not reach the vicinity of the constant voltage.

  In this aspect, when a constant voltage is applied between the first electrode portion and the second electrode portion, if the electrical continuity of one of the electric conductor portions is maintained, two electric conductor portions Is substantially the above-described constant voltage. On the other hand, when the electrical continuity of one of the electrical conductor portions is interrupted, the potential difference between the two electrical conductor portions does not reach the above-described constant voltage. Therefore, if it is determined that dew condensation has occurred on the surface of the semiconductor element when the potential difference between the two electrical conductor portions is smaller than the above-described constant voltage, the presence or absence of dew condensation can be detected with high accuracy. .

  Moreover, in the above-described semiconductor sensor, it is preferable that each of the two electric conductor portions is mainly made of aluminum.

  Furthermore, in the above-described semiconductor sensor, it is preferable that the two electric conductor portions are disposed on the outer peripheral side of a diaphragm formed on the surface of the semiconductor element.

  Hereinafter, specific embodiments of a semiconductor sensor according to the present invention will be described with reference to the drawings.

Embodiment 1

  FIG. 1 shows a top view of a semiconductor sensor 10 according to a first embodiment of the present invention.

  The semiconductor sensor 10 of the present embodiment is a pressure sensor used for automobile engine control, exhaust purification control, or a barometer. The semiconductor sensor 10 can be used, for example, to detect pressure in an exhaust path through which exhaust gas discharged from an internal combustion engine flows. Further, the semiconductor sensor 10 can be used for detecting a pressure difference between an upstream side and a downstream side of a filter installed in the exhaust path. Furthermore, the semiconductor sensor 10 can be used as a particulate quantity detection sensor that detects the particulate quantity deposited on the filter based on the pressure difference between the upstream side and the downstream side of the filter installed in the exhaust path.

  As shown in FIG. 1, the semiconductor sensor 10 includes a silicon (Si) substrate 12 as a semiconductor element. The semiconductor sensor 10 is manufactured by applying a known semiconductor manufacturing technique to the Si substrate 12. The Si substrate 12 is a planar substantially rectangular plate-like member partitioned by four sides. In the Si substrate 12, an opening 14 (a portion surrounded by a broken line in FIG. 1) is formed in a concave shape on the main back surface. The opening 14 is formed by anisotropically etching the Si substrate 12. The opening 14 forms a space surrounded by four diaphragm side walls.

  A thin-walled (thin plate) diaphragm 16 is formed on the main surface side of the opening 14. The opening 14 and the diaphragm 16 are disposed at the approximate center of the surface of the Si substrate 12. The diaphragm 16 is a thin member that can be bent by an amount corresponding to the pressure difference between the front and back sides. The planar shape of the diaphragm 16 is a rectangular shape that is a substantially square surrounded by two pairs of sides facing each other in parallel. The diaphragm 16 is formed as the opening 14 is formed by anisotropically etching the Si substrate 12.

  An electric circuit 18 is formed on the Si substrate 12. The electric circuit 18 is composed of an impurity layer made of boron or phosphorus, or a metal thin film layer made of aluminum or the like. The impurity layer of the electric circuit 18 is formed inside the Si substrate 12. The metal thin film layer of the electric circuit 18 is formed on the surface of the Si substrate 12.

  On the diaphragm 16, strain gauges 20, 22, 24, and 26 that output detection signals corresponding to the deflection of the diaphragm 16 are arranged. The strain gauges 20, 22, 24, and 26 are formed by ion implantation or diffusion of impurities on the main surface of the Si substrate 12. Each of the strain gauges 20, 22, 24, and 26 is a piezoresistor that outputs a detection signal corresponding to a change in resistance value from a reference due to bending at the arrangement portion of the diaphragm 16.

  The strain gauges 20 and 22 are center gauges arranged in the vicinity of the center (near the center of gravity) where the diaphragm 16 is compressed most when the pressure to be detected is applied to the diaphragm 16 among the entire surface of the diaphragm 16. It is. The strain gauges 24, 26 are peripheral portions near the diaphragm side wall of the opening 14, which is a portion where the diaphragm 16 is most pulled when the pressure to be detected is applied to the diaphragm 16 among the portions of the entire surface of the diaphragm 16. In particular, it is a side gauge disposed in the vicinity of the midpoint of the side constituting the diaphragm 16. Hereinafter, the strain gauges 20 and 22 are appropriately referred to as center gauges 20 and 22, and the strain gauges 24 and 26 are referred to as side gauges 24 and 26, respectively. The center gauges 20 and 22 and the side gauges 24 and 26 are provided so that the direction of change in resistance value against stress is reversed.

  The strain gauges 20, 22, 24, 26 are connected and electrically connected via diffusion leads 28 formed by ion implantation or diffusion of impurities on the main surface of the Si substrate 12. The strain gauges 20, 22, 24 and 26 constitute a Wheatstone bridge circuit which is a closed circuit connected in series with each other by the diffusion leads 28. The diffusion lead 28 has a wide area divided into four so as to be divided into four corners in the entire Si substrate 12. The region of each diffusion lead 28 includes four corners in the entire surface of the diaphragm 16 and is defined via a silicon oxide film that is an insulating layer.

  A contact hole 30 and an electrode 32 connected to the diffusion lead 28 are formed on the main surface of the Si substrate 12. Four contact holes 30 and four electrodes 32 are provided. The contact hole 30 and the electrode 32 electrically connect the strain gauges 20, 22, 24, 26 and an external detection device to apply a voltage to the Wheatstone bridge circuit or to output a detection signal from the Wheatstone bridge circuit. It is provided for output. The contact hole 30 and the electrode 32 are formed of a metal thin film on the silicon oxide film, which is an interlayer insulating film on the main surface of the Si substrate 12, by vapor deposition using aluminum or the like.

  In the Wheatstone bridge circuit, when a DC constant voltage V is applied between the two input electrodes 32, the deflection of the diaphragm 16 appears as a change in the resistance value of the strain gauges 20, 22, 24, 26. A voltage detection signal having a level corresponding to the pressure of the detection target is output between the output electrodes 32.

  In the semiconductor sensor 10 having the above-described structure, a glass pedestal or the like is bonded to the main back surface of the Si substrate 12 by anodic bonding or the like. The inside of the opening 14 formed on the main back surface side of the Si substrate 12 is sealed while being maintained at a constant pressure such as a vacuum when being joined to a glass pedestal or the like. Can be treated as a reference room. The semiconductor sensor 10 is mounted in a housing.

  In such a structure of the semiconductor sensor 10, when a pressure to be detected is applied to the main surface side of the Si substrate 12, the diaphragm 16 bends according to the applied pressure. At this time, the resistance values of the strain gauges 20, 22, 24, and 26 change due to the deflection of the diaphragm 16, and voltage detection signals corresponding to the applied pressure are output from the strain gauges 20, 22, 24, and 26. The Such a voltage signal is sent from the electrode 32 to an external detection device for signal processing. Thereby, the pressure of the detection target is detected by the external detection device.

  In addition, the semiconductor sensor 10 of this embodiment includes a failure prediction circuit (that is, a dew condensation detection circuit) 40 for determining the presence or absence of dew condensation on the surface of the Si substrate 12 as a semiconductor element. The failure prediction circuit 40 is a circuit for predicting a failure before the Si substrate 12 fails due to electrolytic corrosion due to condensation, and an electric circuit 18 formed on the Si substrate 12 together with a circuit for detecting pressure. Part of. According to the failure prediction circuit 40, it is possible to detect the dew condensation occurring on the surface of the Si substrate 12 before causing the failure of the pressure sensor part. It is possible to prevent the pressure of the detection target from being normally detected from when the failure occurs until the Si substrate 12 is replaced or repaired.

  The failure prediction circuit 40 is formed on the Si substrate 12 in the same process as other circuit parts of the electric circuit 18. The failure prediction circuit 40 has two electric conductor portions 42 and 44, two fixed resistance portions 46 and 48, and two electrode portions 50 and 52.

  The electric conducting wire portions 42 and 44 are respectively provided on the outer peripheral side of the diaphragm 16 disposed substantially at the center on the surface of the Si substrate 12. The electric conductor portions 42 and 44 each extend on the surface of the Si substrate 12 so as to surround the periphery of the diaphragm 16. The two electric conducting wire portions 42 and 44 are disposed on the surface of the Si substrate 12 so as to face each other over almost the entire circumference of the diaphragm 16.

  Each of the electric conducting wire portions 42 and 44 extends on the surface of the Si substrate 12 so as to be continuous in a state of being folded in a U shape, ie, meandering in a rectangular shape. The shape of the electric conducting wire portions 42 and 44 on the surface of the Si substrate 12 is a shape that easily collects moisture that is condensed when condensation occurs on the surface of the Si substrate 12. The minimum separation distance between the electric conducting wire portion 42 and the electric conducting wire portion 44 (that is, the facing distance between the two conducting wire portions 42, 44) is an arbitrary value selected from all the electrode portions and electric wiring portions of the electric circuit 18 Among the distances between the two electrode portions or the electric wiring portions, the distance is smaller than the minimum distance excluding the minimum separation distance between the electric conducting wire portion 42 and the electric conducting wire portion 44. That is, the minimum separation distance between the electrical conductor portion 42 and the electrical conductor portion 44 is between any two electrode portions or electrical wiring portions selected from all the electrode portions and electrical wiring portions of the electrical circuit 18. Is the smallest of the distances.

  The electrical conductor portions 42 and 44 are disposed on the outer peripheral side of the circuit component (for example, the electrode 32) other than the failure prediction circuit 40 of the electrical circuit 18 on the surface of the Si substrate 12. On the surface of the Si substrate 12, the electric conductor portion 42 is disposed on the inner peripheral side (diaphragm 16 side), and the electric conductor portion 44 is disposed on the outer peripheral side (outer edge side of the Si substrate 12). Each of the electric conducting wire portions 42 and 44 is mainly formed of a metal thin film made of aluminum having the largest ionization tendency among general materials used in forming a thin film in a semiconductor process.

  A first electrode unit 50 is connected to the inner conductive wire portion 42. In addition, a second electrode portion 52 is connected to the outer peripheral electrical conductor 44. The electrode portions 50 and 52 are each formed of a metal thin film mainly made of aluminum. A high potential is applied to the first electrode unit 50. Further, a low potential is applied to the second electrode portion 52. For this reason, a high potential is applied to the electrical conductor portion 42 via the first electrode portion 50, and a low potential is applied to the electrical conductor portion 44 via the second electrode portion 52. .

  The potential applied to the first electrode unit 50 is set higher than the potential applied to the second electrode unit 52 and further to a value higher than the potential applied to other circuit components of the electric circuit 18. Has been. Hereinafter, the electrical conductor portion 42 will be appropriately referred to as a high potential electrical conductor portion 42 and the electrical conductor portion 44 will be referred to as a low potential electrical conductor portion 44, respectively. On the surface of the Si substrate 12, the high potential electrical conductor portion 42 is disposed near the low potential electrical conductor portion 44 between the low potential electrical conductor portion 44 and circuit components other than the failure prediction circuit 40 of the electrical circuit 18. Yes.

  The electrode parts 50 and 52 are respectively arranged on the corners of the Si substrate 12 on the surface of the Si substrate 12. One end of a high-potential electric conductor portion 42 is connected to the first electrode portion 50. The high potential electric conductor portion 42 extends from the first electrode portion 50 through the sides of the Si substrate 12 to the vicinity of the first electrode portion 50 while facing the low potential electric conductor portion 44. The high-potential electric conductor 42 extends in parallel with each side of the Si substrate 12 while meandering on the surface of the Si substrate 12. Further, one end of a first fixed resistance unit 46 whose resistance value is fixed to a predetermined value in advance is connected to the first electrode unit 50. The first fixed resistance portion 46 is provided in the vicinity of the first electrode portion 50. The other end of the first fixed resistance portion 46 is connected to the other end of the high-potential electric conductor portion 42. The first fixed resistance portion 46 is connected in parallel to the high potential electric conducting wire portion 42.

  Between one end and the other end of the high-potential electric conducting wire portion 42, one end of a second fixed resistance portion 48 whose resistance value is fixed to a predetermined value in advance is connected. One end of the second fixed resistor portion 48 is connected to the other end of the first fixed resistor portion 46 together with the high-potential electric conductor portion 42. The second fixed resistance portion 48 is provided on the same side as the side where the first fixed resistance portion 46 of the Si substrate 12 is provided. The other end of the second fixed resistor portion 48 is connected to one end of the low potential electric conductor portion 44. The fixed resistance portions 46 and 48 are each formed of an impurity layer made of boron, phosphorus or the like.

  On the conducting wire of the low potential electric conducting wire portion 44, the second electrode portion 52 is interposed. The second electrode portion 52 is connected to the other end of the second fixed resistance portion 48 through the low potential electric conducting wire portion 44. The second electrode portion 52 and the second fixed resistance portion 48 are arranged close to each other and are provided on the same side of the Si substrate 12. A portion connecting the second electrode portion 52 and the second fixed resistance portion 48 of the low potential electric conducting wire portion 44 extends on one side of the Si substrate 12, and the length of the portion is relatively short.

  Further, the low potential electric conductor 44 extends from the second electrode 52 to the vicinity of the first electrode 50 through the three sides of the Si substrate 12 while facing the high potential electric conductor 42. The other end of the electric potential conducting wire portion 44 is closed in the vicinity of the first electrode portion 50. A portion of the low potential electric conducting wire portion 44 connecting the second electrode portion 52 and the vicinity of the first electrode portion 50 extends so as to pass through the three sides of the Si substrate 12, and the length of the portion is relatively long. .

  The failure prediction circuit 40 has a controller 60. The controller 60 is electrically connected to the first electrode portion 50 and is electrically connected to the second electrode portion 52. The controller 60 has a constant current (constant) between the first electrode unit 50 and the second electrode unit 52 from the first electrode unit 50 on the high potential side toward the second electrode unit 52 on the low potential side. Current). The controller 60 generates a potential difference between the first electrode unit 50 and the second electrode unit 52 in a situation where a constant current is supplied between the first electrode unit 50 and the second electrode unit 52. Can be detected, and the presence or absence of condensation on the surface of the Si substrate 12 is determined based on the detected potential difference.

  Hereinafter, a failure detection technique performed by the failure prediction circuit 40 will be described with reference to FIGS. 2 and 3.

  FIG. 2 is a circuit configuration diagram of the failure prediction circuit 40 in the semiconductor sensor 10 of the present embodiment. FIG. 3 shows a flowchart of an example of a control routine executed by the controller 60 of the failure prediction circuit 40 in the semiconductor sensor 10 of the present embodiment.

  As shown in FIG. 2, the failure prediction circuit 40 includes a parallel circuit in which a first fixed resistance portion 46 and a high potential electric conductor portion 42 are connected in parallel to each other, and the first fixed resistance portion 46 and a high-potential electric conductor portion 42 are connected in parallel to each other, and a second fixed resistor portion 48 is connected in series between the electrode portions 50 and 52 in series.

  The controller 60 supplies a constant current from the first electrode unit 50 toward the second electrode unit 52 (step 100). If no condensation occurs on the surface of the Si substrate 12 and no disconnection due to electrolytic corrosion occurs in the electrical conductor portions 42 and 44 (specifically, the high potential conductor portion 42), the controller 60 can The current input to the first electrode unit 50 is the side of the parallel circuit of the first fixed resistor unit 46 and the high potential electric conductor unit 42 that is not the first fixed resistor unit 46 (that is, the high potential electric conductor unit 42). Circulate. This input current flows through the high-potential electrical lead portion 42 and then flows toward the second electrode portion 52 via the second fixed resistance portion 48 and the low-potential electrical lead portion 44.

  On the other hand, when dew condensation occurs on the surface of the Si substrate 12, the electrical continuity is cut off due to the occurrence of electrolytic corrosion in various electrode portions and electrical lead wire portions of the electric circuit 18. Generally, when moisture adheres between two electrodes having a potential difference, electrolytic corrosion occurs at the high potential side electrode. In addition, as the distance between the two electrodes is shorter, the electrodes are in contact with each other with a smaller amount of moisture, so that electrolytic corrosion is likely to occur.

  As described above, the minimum separation distance between the electric conductor portion 42 and the electric conductor portion 44 is any two electrode portions or electric wiring portions selected from all the electrode portions and electric wiring portions of the electric circuit 18. Is the smallest of each distance between. In addition, the potential applied to the first electrode unit 50, that is, the potential applied to the high-potential electrical conductor unit 42 is the potential applied to the second electrode unit 52, that is, the potential applied to the low-potential electrical conductor unit 44. Higher than the potential applied to other circuit components of the electric circuit 18. For this reason, on the Si substrate 12, condensation is likely to occur between the high potential electrical conductor portion 42 and the low potential electrical conductor portion 44 in the electrical circuit 18, and the high potential electrical conductor portion 42 is most susceptible to electrolytic corrosion due to condensation. It is a site that tends to occur.

  When dew condensation occurs on the surface of the Si substrate 12 and electrolytic corrosion due to dew condensation occurs on the high-potential electric conducting wire portion 42 and disconnection occurs, the current input from the controller 60 to the first electrode portion 50 is the high-potential electric current. Since the conducting wire portion 42 cannot be circulated, the first fixed resistance portion 46 is circulated. The input current flows through the first fixed resistance portion 46 and then flows toward the second electrode portion 52 via the second fixed resistance portion 48 and the low-potential electric conducting wire portion 44.

  As described above, in the failure prediction circuit 40, when the disconnection due to electrolytic corrosion due to condensation does not occur in the high potential conductor portion 42, the current input to the first electrode portion 50 flows through the high potential electrical conductor portion 42. After that, it flows through the second fixed resistance portion 48 and flows toward the second electrode portion 52. For this reason, in this case, the current value of the current input to the first electrode unit 50 and the resistance value of the second fixed resistor unit 48 are between the first electrode unit 50 and the second electrode unit 52. A relatively small potential difference is generated according to. On the other hand, if a disconnection due to electrolytic corrosion due to condensation has occurred in the high-potential lead wire portion 42, the second fixed resistance is supplied after the current input to the first electrode portion 50 flows through the first fixed resistance portion 46. It flows through the part 48 and flows toward the second electrode part 52. Therefore, in this case, between the first electrode unit 50 and the second electrode unit 52, the current value of the current input to the first electrode unit 50, the first fixed resistance unit 46, and the second electrode unit 50 A relatively large potential difference is generated according to the series resistance value with the fixed resistance portion 48.

  For example, the constant current supplied between the first electrode unit 50 and the second electrode unit 52 is 1 mA, the resistance value of the first fixed resistor unit 46 is 1 kΩ, and the second fixed Assuming that the resistance value of the resistance portion 48 is 4 kΩ, the potential difference generated between the first electrode portion 50 and the second electrode portion 52 is 4 V when the high potential conducting wire portion 42 is not disconnected. . On the other hand, when the high potential conducting wire portion 42 is disconnected, the potential difference generated between the first electrode portion 50 and the second electrode portion 52 is 5V. It is possible to determine whether or not condensation has occurred on the surface of the Si substrate 12 by the change in potential difference as described above.

  The controller 60 generates a potential difference between the first electrode unit 50 and the second electrode unit 52 in a situation where a constant current is supplied between the first electrode unit 50 and the second electrode unit 52. Is detected (step 102). Then, the controller 60 determines whether or not the electrical conduction of the high-potential lead wire portion 42 is interrupted based on the detected potential difference between the first electrode portion 50 and the second electrode portion 52, that is, the Si substrate 12. It is determined whether or not condensation occurs on the surface.

  Specifically, the controller 60 supplies the detected potential difference between the first electrode unit 50 and the second electrode unit 52 between the first electrode unit 50 and the second electrode unit 52. It is determined whether or not it is larger than the normal potential difference determined from the current value of the constant current and the resistance value of the second fixed resistance section 48 (or a value larger than the normal potential difference by a predetermined threshold value) (step) 104). Alternatively, the controller 60 determines that the detected potential difference between the first electrode unit 50 and the second electrode unit 52 is a constant current supplied between the first electrode unit 50 and the second electrode unit 52. It is determined whether or not the current value and the series resistance value of the first fixed resistance unit 46 and the second fixed resistance unit 48 have reached the vicinity of the potential difference (abnormal potential difference).

  When the controller 60 makes a negative determination, that is, when the detected potential difference between the first electrode unit 50 and the second electrode unit 52 is equal to or less than the normal potential difference, or the detected first electrode. When the potential difference between the portion 50 and the second electrode portion 52 does not reach the vicinity of the abnormal potential difference, it is determined that the electrical conduction of the high potential conductor portion 42 is not interrupted, and the surface of the Si substrate 12 is It is determined that no condensation has occurred (step 106). On the other hand, when the controller 60 makes an affirmative determination, that is, when the detected potential difference between the first electrode unit 50 and the second electrode unit 52 is larger than the normal potential difference, or the detected first electrode. When the potential difference between the portion 50 and the second electrode portion 52 has reached the vicinity of the abnormal potential difference, it is determined that the electrical conduction of the high potential conductor portion 42 is interrupted, and the surface of the Si substrate 12 is It is determined that condensation has occurred (step 108).

  Therefore, in the failure prediction circuit 40, a constant current is supplied between the two electrode portions 50 and 52 to which different potentials are applied on the surface of the Si substrate 12. Based on the generated potential difference, that is, the potential difference generated between the electrical conductor portions 42 and 44, the presence or absence of disconnection occurring in the electrical conductor portion 42 can be accurately detected, and the presence or absence of condensation occurring on the surface of the Si substrate 12 can be accurately detected. Can be detected.

  As described above, the minimum separation distance between the electric conducting wire portion 42 and the electric conducting wire portion 44 is any two electrode portions or electric wiring portions selected from all the electrode portions and electric wiring portions included in the electric circuit 18. In the electric circuit 18, moisture due to condensation is likely to adhere between the high potential electric conductor portion 42 and the low potential electric conductor portion 44 on the Si substrate 12. In addition, electrolytic corrosion due to condensation is most likely to occur in the high-potential electrical conductor 42. For this reason, when the dew condensation occurs on the surface of the Si substrate 12, the portion of the electric circuit 18 on the Si substrate 12 that has the earliest timing of electrolytic corrosion is the high-potential electric conductor portion 42. Therefore, in the failure prediction circuit 40, the Si substrate 12 (particularly, a portion for detecting the pressure of the detection target, that is, an electrode other than the electric wire portions 42 and 44 in the electric circuit 18 or an electric wire portion) is caused by condensation. It is possible to detect the dew condensation that has occurred on the surface of the Si substrate 12 before the failure occurs.

  Further, in the failure prediction circuit 40 of the present embodiment, as described above, the electric conductor portions 42 and 44 meander in a rectangular shape so as to continue in a folded state on the surface of the Si substrate 12. The shape of the electric conductive wire portions 42 and 44 on the surface of the Si substrate 12 is a shape in which the condensed moisture is easily stored when the condensation occurs on the surface of the Si substrate 12. For this reason, on the Si substrate 12, moisture adhesion due to condensation is promoted between the high potential electrical conductor portion 42 and the low potential electrical conductor portion 44 in the electrical circuit 18, and electrolytic corrosion of the high potential electrical conductor portion 42 is promoted. Is promoted. Therefore, the failure prediction circuit 40 can accurately and quickly detect condensation on the surface of the Si substrate 12.

  Further, in the failure prediction circuit 40 of the present embodiment, as described above, the high-potential electrical conductor portion 42 and the low-potential electrical conductor portion 44 are each of the general materials used mainly for forming a thin film in a semiconductor process. It is formed of a metal thin film made of aluminum having the largest ionization tendency. The greater the ionization tendency, the shorter the time until disconnection due to electrical corrosion of the high-potential electrical conductor 42 when condensation occurs. Therefore, the failure prediction circuit 40 can improve sensitivity in detecting dew condensation on the surface of the Si substrate 12.

  Further, in the failure prediction circuit 40 of the present embodiment, as described above, the high potential electrical conductor portion 42 is formed on the surface of the Si substrate 12 except for the failure prediction circuit 40 in the low potential electrical conductor portion 44 and the electrical circuit 18. It is arranged near the low potential electric conductor 44 between the circuit components (electrode part, electric conductor, etc.). Generally, when moisture adheres between two electrodes having a potential difference, electrolytic corrosion occurs at the high potential side electrode. For this reason, even when the potential of the low potential electrical conductor portion 44 is lower than the potential of the electrode portion or electrical conductor portion other than the high potential electrical conductor portion 42 in the electrical circuit 18, the low potential electrical conductor portion 44 and the high potential Condensation occurs between the low-potential electrical conductor 44 and the electrode section or electrical conductor other than the high-potential electrical conductor 42 in the electrical circuit 18 before the condensed moisture adheres to the electrical conductor 42. Moisture does not collect easily. Therefore, before detecting the dew condensation that has occurred on the surface of the Si substrate 12, the failure prediction circuit 40 is subject to electrolytic corrosion caused by dew condensation in the electrode portions or the electric wire portions other than the electric wire portions 42 and 44 in the electric circuit 18. It is possible to avoid the failure of the semiconductor sensor 10.

  As described above, in the semiconductor sensor 10 according to the present embodiment, it is possible to detect the dew condensation occurring on the surface of the Si substrate 12 before causing the failure of the pressure sensor portion, thereby causing the dew condensation. Thus, it is possible to prevent the pressure of the detection target from being normally detected until the Si substrate 12 is replaced / repaired after the failure of the pressure sensor portion.

  In the first embodiment described above, the Si substrate 12 is described in the “semiconductor element” described in the claims, and the high potential electric conductor portion 42 and the low potential electric conductor portion 44 are described in the claims. Whether the electrical conduction of the high-potential lead wire portion 42 is interrupted based on the potential difference between the first electrode portion 50 and the second electrode portion 52 detected by the controller 60 in the “two electric lead wire portions”. In the “condensation detection circuit” described in the claims, the first fixed resistance portion 46 is described in the claims. In the “first resistor”, the first electrode unit 50 is described in the claims “first electrode unit”, and the second fixed resistor unit 48 is described in the claims “second resistor”. Of the second electrode portion 52 described in the claims. In the “electrode part”, the controller 60 is fixed between the first electrode part 50 and the second electrode part 52 from the first electrode part 50 on the high potential side toward the second electrode part 52 on the low potential side. Supplying current corresponds to “constant current distribution means” described in the claims.

Embodiment 2

  FIG. 4 is a top view of the semiconductor sensor 100 according to the second embodiment of the present invention. In FIG. 4, the same components as those of the first embodiment shown in FIG. 1 are denoted by the same reference numerals, and the description thereof is omitted or simplified.

  The semiconductor sensor 100 of the present embodiment is a sensor used for automobile engine control, exhaust purification control, barometer, and the like, similar to the semiconductor sensor 10 of the first embodiment described above. The semiconductor sensor 100 can be used, for example, to detect pressure in an exhaust path through which exhaust gas discharged from an internal combustion engine flows. Further, the semiconductor sensor 100 can be used to detect a pressure difference between the upstream side and the downstream side of a filter installed in the exhaust path. Furthermore, the semiconductor sensor 100 can be used as a particulate quantity detection sensor that detects the particulate quantity deposited on the filter based on the pressure difference between the upstream side and the downstream side of the filter installed in the exhaust path.

  As shown in FIG. 4, the semiconductor sensor 100 includes a failure prediction circuit (that is, a condensation detection circuit) 102 for determining the presence or absence of condensation on the surface of the Si substrate 12 as a semiconductor element. The failure prediction circuit 102 has the same function as the failure prediction circuit 40 as a part of the electric circuit 18 in the first embodiment described above, and the semiconductor sensor 100 of this embodiment is replaced with the failure prediction circuit 40. This is realized by using the failure prediction circuit 102. The failure prediction circuit 102 is formed on the Si substrate 12 in the same process as other circuit parts of the electric circuit 18. The failure prediction circuit 102 has two electric conductor portions 42 and 44, one fixed resistance portion 104, and two electrode portions 50 and 52. The failure prediction circuit 40 according to the first embodiment is used when a constant current is supplied between the two electrode portions 50 and 52, and includes the two fixed resistance portions 46 and 48, while the failure prediction circuit according to the second embodiment. 102 is used when a constant voltage is applied between the two electrode portions 50 and 52, and includes one fixed resistance portion 104.

  One end of a high-potential electric conductor portion 42 is connected to the first electrode portion 50. One end of the fixed resistance portion 104 is connected to the other end of the high potential electric conducting wire portion 42. The fixed resistance unit 104 is provided on the same side as the side connecting the first electrode unit 50 and the second electrode unit 52 of the Si substrate 12. The other end of the fixed resistor portion 104 is connected to one end of the low potential electric conducting wire portion 44. The fixed resistance portion 104 is formed of an impurity layer made of boron or phosphorus.

  On the conducting wire of the low potential electric conducting wire portion 44, the second electrode portion 52 is interposed. The low-potential electrical conductor 44 extends from the second electrode 52 through the three sides of the Si substrate 12 to the vicinity of the first electrode 50 while facing the high-potential electrical conductor 42. The other end of the conducting wire portion 44 is closed in the vicinity of the first electrode portion 50. A portion of the low potential electric conducting wire portion 44 connecting the second electrode portion 52 and the vicinity of the first electrode portion 50 extends so as to pass through the three sides of the Si substrate 12, and the length of the portion is relatively long. .

  The failure prediction circuit 102 has a controller 110. The controller 110 is electrically connected to the first electrode portion 50 and is electrically connected to the second electrode portion 52. The controller 110 applies a constant potential difference (constant voltage) between the first electrode unit 50 and the second electrode unit 52. In the situation where a constant voltage is applied between the first electrode unit 50 and the second electrode unit 52, the controller 110 actually generates a potential difference between the first electrode unit 50 and the second electrode unit 52. Can be detected, and the presence or absence of condensation on the surface of the Si substrate 12 is determined based on the detected potential difference.

  Hereinafter, a failure detection technique performed by the failure prediction circuit 102 will be described with reference to FIG.

  FIG. 5 shows a flowchart of an example of a control routine executed by the controller 110 of the failure prediction circuit 102 in the semiconductor sensor 100 of the present embodiment.

  The controller 110 applies a constant voltage between the first electrode unit 50 and the second electrode unit 52 (step 200). When no condensation occurs on the surface of the Si substrate 12 and no disconnection due to electrolytic corrosion occurs in the electrical conductor portions 42 and 44 (specifically, the high potential conductor portion 42), the first electrode A potential difference substantially equal to the applied constant voltage is generated between the portion 50 and the second electrode portion 52. On the other hand, when condensation occurs on the surface of the Si substrate 12 and electrolytic corrosion due to condensation occurs in the high-potential electric conductor portion 42 and disconnection occurs, the voltage from the first electrode portion 50 becomes zero or the first thereof. Since the voltage signal from the electrode part 50 disappears, the potential difference generated between the first electrode part 50 and the second electrode part 52 becomes smaller than the constant voltage to be applied and does not reach the constant voltage. .

  In the situation where a constant voltage is applied between the first electrode unit 50 and the second electrode unit 52, the controller 110 actually generates a potential difference between the first electrode unit 50 and the second electrode unit 52. Is detected (step 202). Then, the controller 110 determines whether or not the electrical connection of the high-potential conductor portion 42 is interrupted based on the detected potential difference between the first electrode portion 50 and the second electrode portion 52, that is, the Si substrate 12. It is determined whether or not condensation occurs on the surface.

  Specifically, the controller 110 detects that the detected potential difference between the first electrode unit 50 and the second electrode unit 52 is a constant voltage that is normally applied (or close to the normally applied constant voltage). It is determined whether or not a predetermined threshold value has been reached (step 204). When the controller 110 makes a negative determination, that is, when the detected potential difference between the first electrode unit 50 and the second electrode unit 52 does not reach a normal constant voltage, the high-potential lead wire It is determined that the electrical continuity of the unit 42 is not cut off, and it is determined that no condensation has occurred on the surface of the Si substrate 12 (step 206). On the other hand, when the controller 60 makes an affirmative determination, that is, when the detected potential difference between the first electrode unit 50 and the second electrode unit 52 has reached a normal constant voltage, the high potential lead wire It is determined that the electrical continuity of the part 42 is cut off, and it is determined that condensation has occurred on the surface of the Si substrate 12 (step 208).

  Therefore, in the failure prediction circuit 102, a constant voltage is applied between the two electrode parts 50 and 52 to which different potentials are applied on the surface of the Si substrate 12. Based on the actually generated potential difference, that is, the potential difference actually generated between the electrical conductor portions 42 and 44, it is possible to accurately detect the presence or absence of disconnection occurring in the electrical conductor portion 42, and the dew condensation occurring on the surface of the Si substrate 12 is detected. Presence / absence can be accurately detected.

  As described above, the minimum separation distance between the electric conducting wire portion 42 and the electric conducting wire portion 44 is any two electrode portions or electric wiring portions selected from all the electrode portions and electric wiring portions included in the electric circuit 18. In the electric circuit 18, moisture due to condensation is likely to adhere between the high potential electric conductor portion 42 and the low potential electric conductor portion 44 on the Si substrate 12. In addition, electrolytic corrosion due to condensation is most likely to occur in the high-potential electrical conductor 42. For this reason, when the dew condensation occurs on the surface of the Si substrate 12, the portion of the electric circuit 18 on the Si substrate 12 that has the earliest timing of electrolytic corrosion is the high-potential electric conductor portion 42. Therefore, also in the failure prediction circuit 102, the Si substrate 12 (particularly, the portion for detecting the pressure of the detection target, that is, the electrode or the electrical conductor other than the electrical conductors 42 and 44 in the electrical circuit 18) is caused by condensation. It is possible to detect the dew condensation that has occurred on the surface of the Si substrate 12 before the failure occurs.

  Further, also in the failure prediction circuit 102 of the present embodiment, the electric conductor portions 42 and 44 are continuous on the surface of the Si substrate 12 while being folded in a U-shape, that is, meander in a rectangular shape. The shape of the electric conductive wire portions 42 and 44 on the surface of the Si substrate 12 is a shape in which the condensed moisture can be easily collected when condensation occurs on the surface of the Si substrate 12. For this reason, on the Si substrate 12, moisture adhesion due to condensation is promoted between the high potential electrical conductor portion 42 and the low potential electrical conductor portion 44 in the electrical circuit 18, and electrolytic corrosion of the high potential electrical conductor portion 42 is promoted. Is promoted. Therefore, the failure prediction circuit 102 can detect condensation on the surface of the Si substrate 12 accurately and promptly.

  Also in the failure prediction circuit 102 of the present embodiment, the high-potential electrical conductor portion 42 and the low-potential electrical conductor portion 44 each have an ionization tendency among the general materials used mainly for thin film formation in semiconductor processes. It is formed of a metal thin film made of the largest aluminum. The greater the ionization tendency, the shorter the time until disconnection due to electrical corrosion of the high-potential electrical conductor 42 when condensation occurs. Therefore, the failure prediction circuit 102 can improve sensitivity in detecting dew condensation on the surface of the Si substrate 12.

  Also in the failure prediction circuit 102 of the present embodiment, the high potential electrical conductor portion 42 is a circuit component other than the failure prediction circuit 40 in the low potential electrical conductor portion 44 and the electrical circuit 18 on the surface of the Si substrate 12 ( Between the electrode portion and the electric conductor portion) and the like near the low potential electric conductor portion 44. Generally, when moisture adheres between two electrodes having a potential difference, electrolytic corrosion occurs at the high potential side electrode. For this reason, even when the potential of the low potential electrical conductor portion 44 is lower than the potential of the electrode portion or electrical conductor portion other than the high potential electrical conductor portion 42 in the electrical circuit 18, the low potential electrical conductor portion 44 and the high potential Condensation occurs between the low-potential electrical conductor 44 and the electrode section or electrical conductor other than the high-potential electrical conductor 42 in the electrical circuit 18 before the condensed moisture adheres to the electrical conductor 42. The accumulated moisture does not collect. Therefore, before detecting the dew condensation generated on the surface of the Si substrate 12, the failure prediction circuit 102 performs electrolytic corrosion caused by dew condensation on the electrode parts or the electric lead parts other than the electric lead parts 42 and 44 in the electric circuit 18. A failure of the semiconductor sensor 100 can be avoided.

  Thus, also in the semiconductor sensor 100 of the present embodiment, it is possible to detect the dew condensation that has occurred on the surface of the Si substrate 12 before causing the failure of the pressure sensor portion, thereby causing the dew condensation. Thus, it is possible to prevent the pressure of the detection target from being normally detected until the Si substrate 12 is replaced / repaired after the failure of the pressure sensor portion.

  In the second embodiment, the high potential conductor 42 is disconnected from the electrical potential based on the potential difference between the first electrode 50 and the second electrode 52 detected by the controller 110. In the “condensation detection circuit” described in the claims, the fixed resistance portion 104 is described in the claims. The controller 110 applies a constant voltage between the first electrode unit 50 and the second electrode unit 52 to the “resistance”, which corresponds to the “constant voltage applying unit” described in the claims. doing.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to such specific embodiments, and various modifications and changes can be made within the scope of the gist described in the claims. .

  In the first and second embodiments (see FIGS. 1 and 6), the shape of the electrical conductors 42 and 44 of the failure prediction circuits 40 and 102 on the surface of the Si substrate 12 is the surface of the Si substrate 12. In order to form a shape that easily collects moisture condensed on the surface of the Si substrate 12, the electric conductor portions 42 and 44 are respectively meandered in a rectangular shape on the surface of the Si substrate 12 in a state of being folded in a U-shape. However, the present invention is not limited to this, and the shape of the electric conductor portions 42 and 44 on the surface of the Si substrate 12 is a shape that easily collects moisture condensed on the surface of the Si substrate 12. If it is sufficient, it may be a shape as shown to Fig.7 (a)-(g), or a shape other than that may be sufficient.

  Specifically, as the shape of the electric conductors 42 and 44, (1) as shown in FIG. 1, the electric conductors 42 and 44 are respectively folded in a U-shape on the surface of the Si substrate 12. (2) As shown in FIG. 6, the inner conductive wire portion 42 is linearly extended in parallel with each side on the surface of the Si substrate 12, as shown in FIG. 6. And a shape in which a rectangular shape is continuous while extending the electric conductor 44 on the outer peripheral side in a straight line parallel to each side on the surface of the Si substrate 12, and (3) the electric conductor 42 on the inner peripheral side is made of Si. On the surface of the substrate 12, a rectangular shape is formed while extending linearly in parallel with each side, and the electric conductor 44 on the outer peripheral side is linearly extended in parallel with each side on the surface of the Si substrate 12. (4) Electrical conductors 42, 4 On the surface of the Si substrate 12 and extending in a straight line parallel to each side and projecting in the shape of a comb tooth so as to extend toward the other electric conducting wire 44, 42 side, (5) shown in FIG. 7 (a) As shown in FIG. 7B, the electric conductors 42 and 44 are continuously extended in a triangular shape on the surface of the Si substrate 12, respectively. 44, each of which extends so as to be folded in a semicircular shape on the surface of the Si substrate 12, (7) as shown in FIG. The surface of the surface 12 is extended in a straight line in parallel with each side, and the outer peripheral electrical conductor 44 is linearly extended in the shape of a straight line in parallel with each side on the surface of the Si substrate 12. (8) As shown in FIG. 7 (d) The inner conductive wire portion 42 is linearly extended in parallel to each side on the surface of the Si substrate 12, and the outer peripheral electric conductor portion 44 is linear in parallel to each side on the surface of the Si substrate 12. (9) As shown in FIG. 7 (e), the inner peripheral side electric conductor 42 is formed on each side of the surface of the Si substrate 12. (10) Inner circumference side, extending in a straight line in parallel, and having a continuous circular shape while extending the electric conductor 44 on the outer peripheral side in a straight line parallel to each side on the surface of the Si substrate 12 The electric conducting wire portion 42 is linearly extended in parallel with each side on the surface of the Si substrate 12 and a shape such as a triangle or a hexagon is continuously formed, and the electric conducting wire portion 44 on the outer peripheral side is formed. Directly parallel to each side on the surface of the Si substrate 12 (11) As shown in FIG. 7 (f), the inner peripheral electrical conductor 42 is linearly extended in parallel to each side on the surface of the Si substrate 12, and the outer peripheral side The electric conductor 44 is extended so as to be continuous in a U-shape on the surface of the Si substrate 12, that is, to meander in a rectangular shape. (12) As shown in FIG. The inner conductive wire portion 42 is linearly extended in parallel to each side on the surface of the Si substrate 12, and the outer peripheral electric wire portion 44 is continuous in a triangular shape on the surface of the Si substrate 12. The extended ones are listed.

DESCRIPTION OF SYMBOLS 10,100 Semiconductor sensor 12 Silicon (Si) board | substrate 16 Diaphragm 18 Electrical circuit 40,102 Failure prediction circuit 42 High electric potential electric wire part 44 Low electric potential electric wire part 46 1st fixed resistance part 48 2nd fixed resistance part 50 1st 1 electrode part 52 2nd electrode part 60,110 controller 104 fixed resistance part

Claims (8)

A semiconductor sensor in which an electric circuit made of a metal thin film is formed on the surface of a semiconductor element,
Two electrical conductors arranged opposite to each other on the surface of the semiconductor element as a part of the electrical circuit, to which different potentials are applied;
A dew condensation detection circuit that determines whether or not dew condensation has occurred on the surface of the semiconductor element, based on a potential difference generated in the two electric conductor portions;
A semiconductor sensor comprising:   The separation distance between the two electric conductor portions is smaller than the minimum distance of the distance between any two electrode portions or electric conductor portions of the electric circuit excluding the separation distance. The semiconductor sensor according to claim 1.   A high potential electrical conductor portion to which a high potential is applied among the two electrical conductor portions is a low potential electrical conductor portion to which a low potential is applied among the two electrical conductor portions on the surface of the semiconductor element; The semiconductor sensor according to claim 1, wherein the semiconductor sensor is disposed between an electrode part of the electric circuit or another electric conductor part.   4. The semiconductor sensor according to claim 1, wherein the shape of the two electric conductive wire portions on the surface of the semiconductor element is a shape that easily collects condensed moisture. 5. A first resistor connected in parallel to one of the two electrical conductor portions;
A first electrode connected to the one electrical conductor and connected to one end of the first resistor;
A second resistor having one end connected to the other end of the one electrical conductor and the first resistor;
A second electrode portion connected to the other of the two electric conductor portions and connected to the other end of the second resistor;
Constant current flow means for flowing a constant current between the first electrode portion and the second electrode portion,
The dew condensation detection circuit includes the first electrode unit and the second electrode unit in a situation where a constant current is circulated between the first electrode unit and the second electrode unit by the constant current distribution unit. 5. The semiconductor sensor according to claim 1, wherein dew condensation is generated on a surface of the semiconductor element when the potential difference between the first and second electrodes is larger than a normal potential difference. A first electrode portion connected to one of the two electric conductor portions;
A resistor having one end connected to the one electrical conductor portion;
A second electrode portion connected to the other of the two electric conductor portions and connected to the other end of the resistor;
A constant voltage applying means for applying a constant voltage between the first electrode portion and the second electrode portion,
The dew condensation detection circuit is configured such that a potential difference generated between the two electric conducting wire portions is the constant voltage when a constant voltage is applied between the first electrode portion and the second electrode portion by the constant voltage applying unit. 5. The semiconductor sensor according to claim 1, wherein when it does not reach the vicinity of, it is determined that condensation has occurred on a surface of the semiconductor element.   The semiconductor sensor according to claim 1, wherein each of the two electric conducting wire portions is mainly made of aluminum.   The semiconductor sensor according to claim 1, wherein the two electric conducting wire portions are arranged on an outer peripheral side of a diaphragm formed on a surface of the semiconductor element.

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