JP2008256477A - Manufacturing method of sensing element, sensing element, and sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a sensor element, the sensor element and a sensor, wherein a discrimination mark is provided by laser irradiation, and the mark does not become difficult to be read by being peeled or the like. <P>SOLUTION: This manufacturing method of the sensor element having a bottomed cylindrical solid electrolyte body having a collar part projecting to the radial direction, an outside electrode formed on the outside surface of the solid electrolyte body, and an inside electrode arranged on the inside surface has a laser forming process for irradiating laser onto the outside surface on the furthermore rear end side than an unbaked collar part 13' of a ceramic molded body 1' which becomes a solid electrolyte body after baking, and forming an irradiation object part 2' which becomes the discrimination mark after baking; and a spraying process for spraying gas toward the irradiation object part. The sensor element has the discrimination mark formed by hollowing the surface on the outside surface on the furthermore rear end side than the collar part, and the sensor has a characteristic wherein the discrimination mark is not overlapped with a packed bed. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a sensor element, a sensor element, and a sensor. More specifically, since the identification mark such as the production lot number is formed by laser irradiation, the present invention does not become difficult to read due to peeling or the like, and the unfired ceramic molded body is irradiated with the laser. The present invention relates to a method for manufacturing a sensor element, a sensor element, and a sensor that are advantageous in terms of cost.

  The bottomed cylindrical sensor element that constitutes the oxygen sensor element or the like is provided with an identification mark such as a manufacturing lot number for tracking the manufacturing history on the outer side surface of the ceramic molded body that is fired to become the element body. Has been. This identification mark is usually formed by printing a paste containing platinum and ceramic powder such as zirconia, and then firing the paste together with a ceramic molded body.

  Furthermore, an IC card manufacturing method for stamping or printing an identification code and a pattern for specifying an IC card manufacturing date, a manufacturing lot number, etc. is known. As this stamping or printing method, laser processing, ink jet printing, etc. Etc. are exemplified (for example, refer to Patent Document 1).

  However, in the method of printing a paste containing platinum and a ceramic powder such as zirconia, and then firing with a ceramic molded body to form an identification mark, there is a concern about peeling due to insufficient adhesion of platinum to the ceramic molded body, In the subsequent process, the identification mark may come into contact with the apparatus and other articles and peel off, making it difficult to read. Moreover, since platinum is expensive, it is disadvantageous in terms of cost.

  In addition, in the IC card manufacturing method described in Patent Document 1, it is described that an identification code and a pattern for specifying a manufacturing lot number and the like are stamped or printed by laser processing or the like, Since the sensor characteristics and the like are affected by attaching the IC card or the like, the IC card cannot be attached to the ceramic molded body.

  Therefore, as in Patent Document 2, lot numbers, products, etc. without reducing the strength of the thin article such as a blade made of zirconia ceramics such as partially stabilized zirconia without reducing the strength. A laser marking method for providing a mark or the like is also known.

JP 2004-38852 A JP 2004-175624 A

  However, since the ceramic molded body used for the sensor element is small and has a cylindrical shape, even if an identification mark such as a production lot number is simply formed on the ceramic molded body by using a laser marking method, characters, etc. May not be clearly recognized and may be difficult to read.

  The present invention has been made in view of the above-described conventional situation, and even if an identification mark such as a manufacturing lot number is formed by laser irradiation, a method for manufacturing a sensor element that does not become difficult to read and this method An object of the present invention is to provide a sensor element and a sensor manufactured by the above method.

The present invention is as follows.
1. A bottomed cylindrical solid electrolyte body extending in the axial direction and projecting in the radial direction and having a closed tip side, and disposed on the outer surface of the solid electrolyte body on the tip side of the collar part In the manufacturing method of a sensor element having an outer electrode and an inner electrode arranged on the inner surface of the solid electrolyte body, an unfired collar part that becomes the collar part of the ceramic molded body that becomes the solid electrolyte body after firing A laser forming step of irradiating a laser on the outer side of the rear end side to form an irradiated portion that becomes an identification mark after firing, and a spraying step of blowing gas toward the irradiated portion A method for manufacturing a sensor element.
2. The sensor element includes an outer electrode lead portion electrically connected to the outer electrode and disposed on the outer surface of the solid electrolyte body from the rear end of the outer electrode to the rear end side of the flange portion. And in the laser forming step, the irradiated portion is provided at a position that does not overlap the outer electrode lead pattern that becomes the external electrode lead portion after firing. The manufacturing method of the sensor element of description.
3. The outer electrode lead portion is connected to the connecting lead portion extending in the axial direction from the rear end of the outer electrode to the rear end side of the flange portion, and is connected to the connection lead portion, and the rear end side of the flange portion. And a ring lead portion connected in the circumferential direction of the solid electrolyte body, and the irradiated portion is formed on the tip side of the ring lead pattern that becomes the ring lead portion after firing. The manufacturing method of the sensor element of description.
4). The said irradiated part is formed so that the depth of a groove | channel may be set to 30-100 micrometers. To 3. The manufacturing method of the sensor element of any one of these.
5. A bottomed cylindrical solid electrolyte body extending in the axial direction and projecting in the radial direction and having a closed tip side, and disposed on the outer surface of the solid electrolyte body on the tip side of the collar part A sensor element having an outer electrode and an inner electrode disposed on an inner surface of the solid electrolyte body, the sensor element having an identification mark formed by recessing the sensor element on the outer surface on the rear end side of the flange. A sensor element characterized by that.
6). The sensor element includes an outer electrode lead portion electrically connected to the outer electrode and disposed on the outer surface of the solid electrolyte body from the rear end of the outer electrode to the rear end side of the flange portion. The identification mark is not overlapped with the outer electrode lead portion. The sensor element according to 1.
7). The outer electrode lead portion is connected to the connecting lead portion extending in the axial direction from the rear end of the outer electrode to the rear end side of the flange portion, and is connected to the connection lead portion, and the rear end side of the flange portion. And the ring lead portion connected in the circumferential direction of the solid electrolyte body, and the identification mark is disposed on the tip side of the ring lead portion. Or 6. The sensor element according to 1.
8). A sensor element extending in the axial direction; a metal shell surrounding the periphery of the sensor element so as to protrude from the tip side of the sensor element; and a filling layer disposed in a gap between the sensor element and the metal shell; The sensor element includes the above-mentioned 5. To 7. A sensor element according to any one of the preceding claims, wherein the identification mark does not overlap the filling layer.

According to the method for manufacturing a sensor element of the present invention, an irradiated portion that becomes an identification mark such as a manufacturing lot number is formed on a ceramic molded body having a cylindrical shape by laser irradiation, and then toward the irradiated portion. By blowing the gas, the decomposition residue of the organic binder contained in the ceramic molded body is blown off, and the identification mark is displayed more clearly. Therefore, characters and the like can be clearly recognized even for a relatively small sensor element having a cylindrical shape, and reading does not become difficult due to peeling or the like.
Moreover, since the irradiated portion is provided at a position that does not overlap the outer electrode lead pattern, it is easier to read the identification mark. The outer electrode lead pattern may be provided on the outer surface of the ceramic molded body before the laser forming step, or may be provided on the outer surface of the ceramic molded body after the laser forming step. When the outer electrode lead pattern is formed on the outer surface of the ceramic molded body after the laser forming step, the position where the outer electrode lead pattern is formed is predicted in advance and formed so as not to overlap the position. The outer electrode lead pattern is preferably provided on the outer surface of the ceramic molded body before the laser forming step. Thereby, since the outer electrode lead pattern is not scraped off by laser marking, the conductivity of the outer electrode lead portion after firing is not impaired.
Further, the outer electrode lead part is connected to the connecting lead part extending in the axial direction from the rear end of the outer electrode to the rear end side of the collar part, and connected to the connecting lead part at the rear end side of the collar part. A ring lead portion connected in the circumferential direction of the electrolyte body, and since the irradiated portion is formed on the tip side of the ring lead pattern, it is easier to read the identification mark and Since the electrode lead pattern is not scraped off by laser marking, the conductivity of the outer electrode lead portion after firing is not impaired.
Moreover, when the depth of the groove of the irradiated portion is 30 to 100 μm, it is easy to read the identification mark, and the decrease in strength is sufficiently suppressed.
The sensor element of the present invention is relatively small and can clearly recognize characters and the like even with a sensor element having a cylindrical shape, and does not become difficult to read due to peeling or the like.
Further, the sensor element has an outer electrode lead portion extending from the outer electrode to the rear end side, and the identification mark is provided so as not to overlap the outer electrode lead portion, so that the identification mark can be read more easily. In addition, the conductivity of the outer electrode lead portion is not impaired.
Further, the outer electrode lead part is connected to the connecting lead part extending in the axial direction from the rear end of the outer electrode to the rear end side of the collar part, and connected to the connecting lead part at the rear end side of the collar part. A ring lead connected in the circumferential direction of the electrolyte body, and the identification mark is formed on the tip side of the ring lead, so that the identification mark can be read more easily, and the outer electrode The conductivity of the lead part is not impaired.
Further, when the sensor element is incorporated in the gas sensor, the identification mark does not overlap with the filling layer interposed between the inner surface of the gas sensor metal shell and the outer surface of the sensor element. Further, when the ceramic powder is compacted, a large pressing force is not directly applied to the portion where the identification mark is formed, so that the sensor element can be prevented from being broken.

Hereinafter, the present invention will be described in detail with reference to the drawings.
As shown in FIG. 1, the “sensor element 100” includes a bottomed cylindrical solid electrolyte body 1 obtained by firing a ceramic molded body 1 ′ (see FIGS. 2 and 3), and an outer surface on the surface of the solid electrolyte body 1. An electrode 111 and an outer electrode lead portion 14 are provided. The solid electrolyte body 1 includes a sensing part 11 on the front end side, a base part 12 on the rear end side, and a collar part 13 that is an intermediate part between the sensing part 11 and the base part 12. The wall thickness is thin, and the base portion 12 is thicker than the sensing portion 11. In addition, an outer electrode 111 is provided on the outer surface of the sensing unit 11, and a reference electrode (not shown) is provided on the inner surface. Further, as shown in FIG. 1, an outer electrode lead portion 14 is provided so as to be connected to the outer electrode 111 and straddle the flange portion 13 toward the outer surface of the base portion 12. The outer electrode lead portion 14 straddles the flange portion 13 in order to connect the ring lead portion 141 provided on the outer surface of the rear end side 121 of the base portion 12 to the outer electrode 111 and the ring lead portion 141. And a connecting lead part 142.

  The “ceramic molded body 1 ′” is fired to form the solid electrolyte body 1 of the sensor element 100. The ceramic molded body 1 ′ has a bottomed cylindrical shape as shown in FIG. 3, and an unfired sensing portion 11 ′ that becomes the sensing portion 11 of the sensor element 100 and a base body portion 12 as shown in FIGS. 2 and 3. And an unfired brim part 13 ′ that is an intermediate part between the unfired sensing part 11 ′ and the unfired base part 12 ′ and becomes the brim part 13. The internal space 15 ′ of the ceramic molded body 1 ′ has a circular cross section, and the outer peripheral surface and the inner peripheral surface are formed concentrically. Further, as shown in FIGS. 2 and 3, the outer diameter of the ceramic molded body 1 ′ is the same as that of the unfired base portion 12 ′, and the diameter gradually decreases from directly below the flange portion 13 ′ toward the unfired sensing portion 11 ′. It is small.

  Examples of the ceramic used for producing the ceramic molded body 1 ′ include a ceramic that acts as a solid electrolyte. For example, oxygen sensor elements that conduct oxygen ions often use zirconia, particularly stabilized zirconia stabilized by yttria or the like.

The unfired base portion 12 ′, which is the base portion 12 of the sensor element 100, on the outer surface of the ceramic molded body 1 ′ is irradiated with a laser, and the “irradiated” for displaying an identification mark as shown in FIG. Part 2 '"is formed. The position where the irradiated portion 2 ′ is formed is the outer surface of the unfired substrate portion 12 ′ of the ceramic molded body 1 ′, and the identification mark 2 as shown in FIG. 1 formed by firing can be read. As long as there is no particular limitation. Further, the laser to be used is not particularly limited, and examples thereof include a carbon dioxide gas laser and a YAG laser. Further, the irradiation apparatus is not particularly limited, and a general irradiation apparatus including a laser oscillator, a laser modulator, a handling unit, a controller, and the like can be used.
Note that the identification mark 2 in FIG. 1 and the irradiated portion 2 ′ in FIG. 2 are configured by characters, figures, symbols, or a combination thereof, specifically, a manufacturing lot number for tracking a manufacturing history, a manufacturing year, and the like. Month and date, product marks, etc.

  The irradiated portion 2 ′ is formed at the position as described above. However, when the outer electrode lead pattern 14 ′ is provided on the outer surface of the ceramic molded body 1 ′, as shown in FIG. 'Is preferably formed in a portion where the outer electrode lead pattern 14' is not provided. In this way, it is easy to read the identification mark, and the continuity of the outer electrode lead portion 14 is not impaired after firing.

  Further, for example, as shown in FIG. 2, the outer electrode lead pattern 14 ′ is provided on the outer surface of the rear end side 121 ′ of the unfired base portion 12 ′ that becomes the base portion 12 of the sensor element 100 of the ceramic molded body 1 ′. The connected ring lead pattern 141 ′ and the ring lead 141 formed by firing the ring lead pattern 141 ′ are electrically connected to the outer electrode 111 provided on the outer surface of the sensing portion 11 of the sensor element 100. A lead pattern 142 'is provided. In this case, as shown in FIG. 2, the irradiated portion 2 ′ is preferably formed on the tip side of the ring lead pattern 141 ′ and at a portion where the connection lead pattern 142 ′ is not provided. Thus, if the irradiated portion 2 ′ is formed so as not to overlap the outer electrode lead pattern 14 ′, the identification mark can be easily read, and the conductivity of the outer electrode lead portion 14 may be impaired after firing. Absent.

  Next, the oxygen sensor 200 will be described with reference to FIG. As shown in FIG. 4, the oxygen sensor 200 includes the above-described sensor element 100, the ceramic heater 3 inserted into the internal space of the sensor element 100, and the metal shell 5 that holds the sensor element 100 inside itself.

  The ceramic heater 3 is formed in a rod shape and includes a heat generating portion 42 having a heat generating resistor therein. When the ceramic heater 3 is energized through heater lead wires 19 and 22 described later, the heat generating portion 42 generates heat, and has a function of heating the sensor element 100 to activate the sensor element 100. Fulfill.

  The metal shell 5 has a screw portion 66 for attaching the oxygen sensor 200 to the attachment portion of the exhaust pipe, and a hexagonal portion 93 to which an attachment tool is applied when attaching the oxygen sensor 200 to the attachment portion of the exhaust pipe. The metal shell 5 includes an alumina support member 51 that supports the sensor element 100 from the front end side, a filling layer 52 made of talc powder that fills the rear end side of the support member 51, and the filling layer 52 at the rear end. An alumina sleeve 53 that presses from the side toward the tip side is configured to be housed inside.

  The metal shell 5 is provided with a metal-side stepped portion 54 projecting radially inward on the inner periphery of the front end side, and the support member 51 is locked to the metal-side stepped portion 54 via a packing 55. Yes. The sensor element 100 is supported by the metal shell 5 by supporting the flange 13 on the support member 51. A filling layer 52 is disposed between the inner surface of the metal shell 5 on the rear end side of the support member 51 and the outer surface of the sensor element 100, and a sleeve 53 and an annular ring 56 are further provided on the rear end side of the filling layer 52. It arrange | positions in the state inserted sequentially coaxially.

  The front end side of the inner cylinder member 41 is inserted inside the rear end side of the metal shell 5. The inner cylinder member 41 has the metal-side rear end 60 of the metal shell 5 in the inner tip direction in a state in which the opening end portion (tip opening end portion 59) having an enlarged diameter on the tip side is in contact with the annular ring 56. The metal shell 5 is fixed by caulking. Note that the oxygen sensor 200 has a structure in which the filling layer 52 is compressed and filled through the sleeve 53 by crimping the metal-side rear end 60 of the metal shell 5, whereby the sensor element 100 is formed into a cylinder. Is held in an airtight manner inside the metal shell 5.

  The inner cylinder member 41 is formed with an inner cylinder stepped portion 83 at a substantially intermediate position in the axial direction, and the inner cylinder stepped portion 83 is formed as an inner cylinder tip side body portion 61 from the inner cylinder stepped portion 83, and the inner cylinder stepped portion is formed. The rear end side of the portion 83 is formed as the inner cylinder rear end side body portion 62. The inner cylinder rear end side body part 62 is formed to have both an inner diameter and an outer diameter smaller than the inner cylinder front end side body part 61, and the inner diameter is slightly larger than the outer diameter of a separator body 85 of the separator 7 described later. ing. In addition, a plurality of air introduction holes 67 are formed in the inner cylinder rear end side body portion 62 at predetermined intervals along the circumferential direction.

  The outer cylinder member 16 is formed in a cylindrical shape, and is formed on the rear end side of the outer cylinder rear end side portion 63 including an opening leading from the outside to the inside, and on the front end side is coaxial with the inner cylinder member 41 from the rear end side. The outer cylinder front end side portion 64 connected to the outer cylinder, and the outer cylinder rear end side portion 63 and the outer cylinder front end side portion 64 are formed. The outer cylinder rear end side portion 63 is formed with a caulking portion 88 for fixing the elastic seal member 40 in an airtight manner.

  Further, a metal protector 81 having a plurality of gas intake holes 82 is attached to the outer periphery of the metal shell 5 on the front end side thereof by covering the front end portion of the sensor element 100 protruding from the tip of the metal shell 5 by welding. .

  Further, a cylindrical filter 68 for preventing water from entering from the air introduction hole 67 is disposed outside the inner cylinder rear end side body portion 62 of the inner cylinder member 41. The filter 68 is, for example, a porous fiber structure of polytetrafluoroethylene (trade name: Gore-Tex (Japan Gore-Tex Co., Ltd.), while preventing the permeation of liquid mainly composed of water, etc. This is configured as a water repellent filter that allows permeation of gas.

  The outer cylinder front end side portion 64 of the outer cylinder member 16 is formed in a shape that covers the inner cylinder member 41 (specifically, the inner cylinder rear end side body portion 62) on which the filter 68 is disposed from the outside. A plurality of air introduction holes 84 are formed at predetermined intervals along the circumferential direction at positions corresponding to the filter 68 in the side portion 64.

  The outer cylinder member 16 and the inner cylinder member 41 are configured such that at least a part of the outer cylinder front end side portion 64 of the outer cylinder member 16 on the rear end side of the air introduction hole 84 is radially passed through the filter 68. The first caulking portion 57 formed by caulking inward and the second caulking formed by caulking at least a part on the tip side of the air introduction hole 84 radially inward through the filter 68 It is fixed by the part 58. At this time, the filter 68 is held in a liquid-tight state between the outer cylinder member 16 and the inner cylinder member 41. Moreover, the outer cylinder front end side portion 64 of the outer cylinder member 16 is disposed so as to overlap from the outer side with respect to the inner cylinder front end side body portion 61, and at least a part of the overlapping portion faces the inner side in the circumferential direction. The connection crimping part 75 is formed by crimping.

  Thereby, the atmosphere as the reference gas is introduced into the atmosphere introduction hole 84, the filter 68 and the atmosphere introduction hole 67, and the inner cylinder member 41, and is introduced into the bottomed hole 25 of the sensor element 100. On the other hand, since water droplets cannot pass through the filter 68, entry into the inner cylinder member 41 is prevented.

  The elastic sealing member 40 disposed inside the rear end of the outer cylinder member 16 (outer cylinder rear end side portion 63) includes two element lead wires 20 and 21 that are electrically connected to the sensor element 100, and ceramic. Four lead wire insertion holes 17 for inserting two heater lead wires 19 and 22 electrically connected to the heater 3 are formed so as to penetrate from the front end side to the rear end side.

  In addition, the separator 7 in which the front end side of the inner cylinder member 41 is inserted and disposed in the inner cylinder rear end side body portion 62 is for inserting the element lead wires 20 and 21 and the heater lead wires 19 and 22. The separator lead wire insertion hole 71 is formed so as to penetrate from the front end side to the rear end side. Further, the separator 7 is formed with a bottomed holding hole 95 opened in the front end surface in the axial direction. The rear end portion of the ceramic heater 3 is inserted into the holding hole 95, and the ceramic heater 3 is positioned in the axial direction with respect to the separator 7 by abutting the rear end surface of the ceramic heater 3 against the bottom surface of the holding hole 95. .

The separator 7 includes a separator main body 85 that is inserted inside the rear end of the inner cylinder member 41 and a separator flange 86 that extends outward from the rear end of the separator main body 85 in the circumferential direction. Yes. That is, in the separator 7, the separator body 85 is inserted into the inner cylinder member 41 and the separator flange 86 is supported on the rear end surface of the inner cylinder member 41 via the annular seal member 45 made of fluoro rubber. The inner cylinder member 16 is disposed inside.

  In addition, the element lead wires 20 and 21 and the heater lead wires 19 and 22 pass through the separator lead wire insertion hole 71 of the separator 7 and the lead wire insertion hole 17 of the elastic seal member 40, and thereby the inner cylinder member 41 and the outer cylinder member 16. It is drawn from the inside to the outside. These four lead wires 19, 20, 21, and 22 are externally connected to a connector (not shown). The external signals such as the ECU and the lead wires 19, 20, 21, and 22 are input / output via the connector.

  Further, although not shown in detail, each lead wire 19, 20, 21, 22 has a structure in which the conducting wire is covered with an insulating film made of resin, and the rear end side of the conducting wire is a connector terminal provided in the connector. Connected. And the front end side of the conducting wire of the element lead wire 20 is crimped with the rear end portion of the terminal fitting 43 fitted on the outer surface of the sensor element 100, and the leading end side of the conducting wire of the element lead wire 21 is It crimps with the rear-end part of the terminal metal fitting 44 press-fit with respect to the inner surface of the sensor element 100. Thereby, the element lead wire 20 is electrically connected to the outer electrode 111 (see FIG. 1) of the sensor element 100, and the element lead wire 21 is electrically connected to the inner electrode. On the other hand, the leading ends of the lead wires 19 and 22 for the heater are respectively connected to a pair of heater terminal fittings joined to the heating resistor of the ceramic heater 3.

  An elastic seal member 40 made of fluorine rubber or the like having excellent heat resistance is fixed to the outer cylinder member 16 at the rear end side of the separator 7 by caulking the outer cylinder member 16 and forming a caulking portion 88. Has been. The elastic seal member 40 includes a main body 31 and a seal member collar 32 extending from the side peripheral surface on the distal end side of the main body 31 toward the radially outer side. Then, four lead wire insertion holes 17 are formed so as to penetrate the main body portion 31 in the axial direction.

  When the irradiated portion 2 ′ is used by incorporating the sensor element 100 into the oxygen sensor 200, the identification mark 2 formed by firing the irradiated portion 2 ′ is a gas sensor (for example, the oxygen sensor 200 in FIG. 4). It is preferable that the filling layer 52 interposed between the inner surface of the metallic shell 5 and the outer surface of the sensor element 100 does not overlap.

  When the sensor element 100 is fixed to the inner surface side of the metal shell 5, the support member 51 is inserted into the metal hardware side step portion 54 of the metal shell 5 via the packing 55, and then the sensor element 100 is attached to the inner surface side of the support member 51. Inserting through the packing 69 with the sensing unit 11 side as the leading end side, then supplying ceramic powder to the rear end side of the support member 51 and compacting to form the filling layer 52, and then inserting the sleeve 53 Then, the front end side is brought into contact with the rear end of the filling layer 52 to fix the sensor element 100, and the space between the inner side surface of the metal shell 5 and the outer side surface of the sensor element 100 is hermetically sealed.

  Although the sensor element 100 is fixed to the inner surface side of the metal shell 5 as described above, a particularly large pressing force is applied to the filling layer 52 when the sleeve 53 is pressed toward the distal end side. Therefore, it is preferable that the identification mark 2 is not formed at a position in contact with the filling layer 52 and is preferably formed at a position in contact with the sleeve 53. Thereby, deformation | transformation, breakage, etc. when incorporating the sensor element 100 can be prevented.

  The ceramic powder used for formation of said filling layer 52 is not specifically limited, A talc is mentioned. Further, instead of forming the filling layer 52 by compaction of ceramic powder, a ring-shaped formed body using ceramic powder mixed with a binder or the like is inserted, and this is pressed to form the filling layer 52. You can also.

  In the present invention, the ceramic molded body 1 ′, which is an unfired body, contains an organic binder, but the organic binder is decomposed by laser irradiation, and the decomposition residue remains in the irradiated portion 2 ′. The identification mark such as the production lot number may become unclear. Therefore, before firing the ceramic molded body, gas is blown to the irradiated portion 2 ′, and the decomposition residue is blown away. Thereby, the identification mark 2 can be displayed more clearly. The gas is preferably air, hydrogen, or nitrogen.

Further, the depth of the groove of the irradiated portion 2 ′ is not particularly limited, but is preferably 30 to 100 μm, particularly preferably 40 to 70 μm. If the depth of the groove is 30 to 100 μm, it is easy to read the identification mark 2 such as the production lot number, and the strength reduction due to the formation of the groove can be suppressed. Furthermore, it is preferable that the width of the opening end face of this groove is 100 to 500 μm, particularly 100 to 300 μm. If the width of the opening end face is 100 to 500 μm, it is easier to read the identification mark 2, and the strength reduction due to the formation of the groove can be sufficiently suppressed. Further, since the groove is formed by laser irradiation, if the width of the opening end face is 100 to 500 μm, it is usually formed narrower than the width of the opening end face to the vicinity of the bottom.
The irradiated portion 2 ′ is formed on the ceramic molded body 1 ′ that is an unfired body, and then fired. Therefore, the depth and width of the groove slightly change due to firing shrinkage, but the irradiated portion 2 ′. If the depth and width of the groove formed in the above are within the above ranges, the identification mark 2 can be easily read after firing.

  Furthermore, in the manufacturing method of the sensor element of the present invention, in addition to the step of forming the irradiated portion 2 ′, a process of producing a molded body that is usually the ceramic molded body 1 ′, particularly the outer surface of the molded body is required. In accordance with the above, various processes such as a process of producing a ceramic molded body 1 ′ by grinding, a baking process, a process of forming an outer electrode, and an inner electrode are provided.

  The firing conditions are not particularly limited, and the firing temperature and firing time are preferably set according to the ceramic type, particle size, and the like. Also, the firing atmosphere is selected from among an inert atmosphere such as an oxidizing atmosphere such as an air atmosphere, a reducing atmosphere containing a predetermined amount of hydrogen gas, and an inert gas atmosphere such as a nitrogen gas atmosphere and an argon gas, depending on the type of ceramic. You can choose from.

  The sensor element 100 of the present invention is manufactured by the method of the present invention, and has an identification mark 2 formed by firing the irradiated portion 2 'as shown in FIG. The identification mark 2 is formed by irradiating the outer surface of the ceramic molded body 1 ′ serving as the element body of the sensor element 100 with the laser on the outer surface of the opening side 12 ′ serving as the base portion 12 of the sensor element 100. The irradiated portion 2 'is fired, and the identification mark 2 such as the production lot number can be easily read. In the firing and the subsequent steps, the identification mark 2 is connected to the apparatus and other articles. It is possible to prevent reading from being difficult due to contact.

  Although the sensor element 100 is incorporated in the gas sensor as described above, it is preferable that the identification mark 2 is not formed at a position in contact with the filling layer 52 but formed at a position in contact with the sleeve 53. Thereby, deformation | transformation, breakage, etc. when incorporating the sensor element 100 can be prevented.

  The sensor element manufactured by the method of the present invention can be used by being incorporated in various gas sensors. Examples of the gas sensor include an exhaust gas sensor of an internal combustion engine such as an oxygen sensor, a carbon monoxide sensor, a hydrocarbon sensor, and a nitrogen oxide sensor.

Hereinafter, the present invention will be specifically described by way of examples.
[1] Manufacture of sensor element (1) Manufacture of ceramic molded body 1 ′ A slurry obtained by wet mixing partially stabilized zirconia powder in which yttria is dissolved, an organic binder and an organic solvent is dried by a spray drying method. Granulated. Thereafter, the granulated product was press-molded using a rubber press to produce a compact. Further, the outer surface of the molded body was ground to produce a ceramic molded body 1 ′ having a predetermined shape (see FIGS. 2 and 3). Next, a concavo-convex material (for example, partially stabilized zirconia powder) is applied to a predetermined position on the tip side of the outer surface of the ceramic molded body 1 ′, and then a conductive paste mainly composed of platinum is predetermined. The outer electrode lead pattern 14 ′ having the ring lead pattern 141 ′ and the connecting lead pattern 142 ′ was formed (see FIG. 2).
The outer diameter of the unfired base portion 12 ′ of the ceramic molded body 1 ′ is 9 mm, the outer diameter of the unfired brim portion 13 ′ is 11 mm, and the tip 111 ′ of the unfired sensing portion 11 ′ is spherical. The diameter was 5 mm.

(2) Laser irradiation On the lateral side of the connection lead pattern that does not overlap the ring lead pattern and the connection lead pattern on the outer surface of the unfired base portion 12 ′ of the ceramic molded body 1 ′ produced as described above. Then, the irradiated part 2 ′ for displaying the production lot number (identification mark) was formed by irradiating the FAYb laser with an output of 20 W by the laser irradiation device (see FIG. 2). When the sensor element 100 is incorporated in the oxygen sensor 200 as described above, the irradiated portion 2 ′ is (Example 1) where the production lot number is in contact with the packed bed 52, or (Example 2) The production lot number was formed at a position where it contacted the sleeve 53.

(3) Manufacture of sensor element 100 500 pieces of two ceramic molded bodies 1 ′ having different formation positions of irradiated portions 2 ′ produced as described in (2) above, the elements are packed in a ceramic sheath, Saya and the ceramic molded body 1 ′ were housed in a firing furnace, fired at 1500 ° C. for 2 hours in an air atmosphere, and then an outer electrode and an inner electrode were provided to manufacture the sensor element 100.

[2] Presence / absence of breakage of sensor element The sensor element 100 manufactured as described in [1] and (3) above was fixed and assembled to the metal shell 5 of the oxygen sensor 200 as described above. Whether or not the sensor element 100 is broken in Example 1 in which the production lot number is formed at a position where it contacts the filling layer 52 and Example 2 where the production lot number is formed at a position where it contacts the sleeve 53 is determined. A comparative study was conducted. As a result, in Example 1 in which the production lot number was formed at a position in contact with the filling layer 52, breakage occurred in part. On the other hand, no breakage occurred in the sensor element 100 formed at the position where the production lot number was in contact with the sleeve 53.

It is a front view of the sensor element which has the production lot number (identification mark) formed by baking the to-be-irradiated part formed by laser irradiation. It is a front view of the ceramic molded body which has an irradiated part which is formed by laser irradiation and displays a manufacturing lot number (identification mark). It is sectional drawing of a ceramic molded body. It is sectional drawing of an example of the oxygen sensor by which the sensor element was arrange | positioned.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 100; Sensor element, 1; Ceramic sintered body, 11; Sensing part, 111; Sensing electrode, 12: Base | substrate part, 121; Opening part, 13: Gutter part, 14: Outer electrode lead part, 141: Ring lead part, 142; lead part for connection, 1 ′; ceramic molded body, 11 ′; unfired detection part, 111 ′; tip part, 12 ′; unfired base part, 121 ′; rear end side, 13 ′; 14 ′; outer electrode lead pattern 141 ′; ring lead pattern 142 ′; connection lead pattern 15 ′; internal space 2; identification mark 2 ′; irradiated portion 200; oxygen sensor 3; 5; metal shell, 51; support member, 52; packed bed, 53; sleeve, 56; annular ring, 41; inner cylinder member, 67; air introduction hole, 68; filter, 16; outer cylinder member, 84; Introduction hole, 40; elastic sea Member, 45; annular sealing member, 7; separator, 81; protector, 82; gas inlet hole, 20, 21; element lead wire, 19 and 22; leads for the heater.

Claims (8)

A bottomed cylindrical solid electrolyte body extending in the axial direction and projecting in the radial direction and having a closed tip side, and disposed on the outer surface of the solid electrolyte body on the tip side of the collar part In the manufacturing method of the sensor element having the outer electrode and the inner electrode disposed on the inner surface of the solid electrolyte body,
After firing the ceramic molded body that becomes the solid electrolyte body after firing, the outer surface on the rear end side is irradiated with a laser from the unfired collar part that becomes the collar part after firing, and an irradiated part that becomes an identification mark after firing is formed. Laser forming process;
And a blowing step of blowing a gas toward the irradiated portion. The sensor element includes an outer electrode lead portion electrically connected to the outer electrode and disposed on the outer surface of the solid electrolyte body from the rear end of the outer electrode to the rear end side of the flange portion. Have
The method for manufacturing a sensor element according to claim 1, wherein in the laser forming step, the irradiated portion is provided at a position that does not overlap the outer electrode lead pattern that becomes the outer electrode lead portion after firing.   The outer electrode lead portion is connected to the connecting lead portion extending in the axial direction from the rear end of the outer electrode to the rear end side of the flange portion, and is connected to the connection lead portion, and the rear end side of the flange portion. And a ring lead portion connected in a circumferential direction of the solid electrolyte body, and the irradiated portion is formed on a tip side of a ring lead pattern that becomes the ring lead portion after firing. The manufacturing method of the sensor element of description.   The sensor element manufacturing method according to any one of claims 1 to 3, wherein the irradiated portion is formed so that a groove has a depth of 30 to 100 µm. A bottomed cylindrical solid electrolyte body extending in the axial direction and projecting in the radial direction and having a closed tip side, and disposed on the outer surface of the solid electrolyte body on the tip side of the collar part A sensor element having an outer electrode and an inner electrode disposed on an inner surface of the solid electrolyte body,
A sensor element comprising an identification mark formed by recessing the sensor element on an outer surface on the rear end side of the flange. The sensor element includes an outer electrode lead portion electrically connected to the outer electrode and disposed on the outer surface of the solid electrolyte body from the rear end of the outer electrode to the rear end side of the flange portion. Have
The sensor element according to claim 5, wherein the identification mark does not overlap the outer electrode lead portion.   The outer electrode lead portion is connected to the connecting lead portion extending in the axial direction from the rear end of the outer electrode to the rear end side of the flange portion, and is connected to the connection lead portion, and the rear end side of the flange portion. The sensor element according to claim 5, further comprising: a ring lead portion connected in a circumferential direction of the solid electrolyte body, wherein the identification mark is disposed on a tip side of the ring lead portion. A sensor element extending in the axial direction;
A metallic shell that surrounds the periphery of the sensor element so as to project the tip side of the sensor element,
In a sensor comprising a filling layer disposed in a gap between the sensor element and the metal shell,
The sensor element is a sensor element according to any one of claims 5 to 7,
The sensor, wherein the identification mark does not overlap the filling layer.

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