JP5582084B2 - Particulate matter detection sensor and manufacturing method thereof - Google Patents

Particulate matter detection sensor and manufacturing method thereof Download PDF

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JP5582084B2
JP5582084B2 JP2011083895A JP2011083895A JP5582084B2 JP 5582084 B2 JP5582084 B2 JP 5582084B2 JP 2011083895 A JP2011083895 A JP 2011083895A JP 2011083895 A JP2011083895 A JP 2011083895A JP 5582084 B2 JP5582084 B2 JP 5582084B2
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匠 牛窪
啓 杉浦
岳人 木全
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Denso Corp
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本発明は、例えば、車両用内燃機関の排気浄化システムに好適に利用されて、被測定ガス中に存在する粒子状物質を検出する電気抵抗式の粒子状物質検出センサに関する。   The present invention relates to an electric resistance particulate matter detection sensor that is suitably used in, for example, an exhaust gas purification system for a vehicle internal combustion engine and detects particulate matter present in a gas to be measured.

自動車用ディーゼルエンジン等において、燃焼排気に含まれる環境汚染物質、特に煤粒子(Soot)及び可溶性有機成分(SOF)を主体とする粒子状物質(Particulate Matter;以下、適宜PMと称する)を捕集するために、排気通路にディーゼルパティキュレートフィルタ(以下、適宜DPFと称する)を設置することが行われている。DPFは、耐熱性に優れる多孔質セラミックスからなり、多数の細孔を有する隔壁に燃焼排気を通過させてPMを捕捉する。   Collects environmental pollutants contained in combustion exhaust, especially particulate matter (Particulate Matter; hereinafter referred to as PM as appropriate) mainly composed of soot particles and soluble organic components (SOF) in automobile diesel engines, etc. In order to do this, a diesel particulate filter (hereinafter referred to as DPF as appropriate) is installed in the exhaust passage. The DPF is made of porous ceramics having excellent heat resistance, and traps PM by allowing combustion exhaust gas to pass through partition walls having a large number of pores.

DPFは、PM捕集量が許容量を超えると、目詰まりが生じて負圧が増大したり、PMのすり抜けが増加したりするおそれがあり、定期的に再生処理を行って捕集能力を回復させている。再生時期は、一般的には、PM捕集量の増加により前後差圧が増大することを利用しており、このため、DPFの上流及び下流の圧力差を検出する差圧センサが設置される。再生処理は、ヒータ加熱あるいはポスト噴射等により高温の燃焼排気をDPF内に導入し、PMを燃焼除去する。   If the amount of collected PM exceeds the allowable amount, DPF may cause clogging and increase the negative pressure or increase the slipping of PM. It is recovering. The regeneration period generally uses the fact that the differential pressure increases with the increase in the amount of PM collected. For this reason, a differential pressure sensor is installed to detect the pressure difference upstream and downstream of the DPF. . In the regeneration process, high-temperature combustion exhaust gas is introduced into the DPF by heater heating or post injection, and PM is combusted and removed.

一方、燃焼排気中のPMを直接検出可能なセンサが、例えば特許文献1、2等に提案されている。このセンサを、DPFの下流に設置した場合には、DPFをすり抜けるPM量を測定し、車載式故障診断装置(OBD;On Board Diagnosis)において、DPFの作動状態の監視、例えば亀裂や破損といった異常の検出に利用することができる。あるいはDPFの上流に設置して、DPFに流入するPM量を測定し、差圧センサに代わる再生時期の判断に利用することも検討されている。   On the other hand, sensors capable of directly detecting PM in combustion exhaust are proposed in, for example, Patent Documents 1 and 2. When this sensor is installed downstream of the DPF, the amount of PM passing through the DPF is measured, and an on-board diagnosis (OBD) monitoring of the operating state of the DPF, for example, abnormalities such as cracks and breakage It can be used for detection. Alternatively, it is also considered to install upstream of the DPF, measure the amount of PM flowing into the DPF, and use it to determine the regeneration time instead of the differential pressure sensor.

特許文献1には、絶縁性を有する基板の表面に、一対の櫛形電極を形成し、基板の裏面又は内部に発熱体を形成した電気抵抗式のスモークセンサが開示されている。このセンサは、スモーク(微粒炭素)が導電性を有することを利用したもので、検出部となる電極間に、スモークが堆積することで生じる電気抵抗値の変化を検出する。基板材料には、電気絶縁性耐熱材料が用いられ、電極材料となるPt、Ag等の貴金属粉をペースト状にして、平板状基板の表面にスクリーン印刷することにより一対の電極が形成される。基板の裏面側には、電極と相対する部分に発熱体が形成され、検出部を所望の温度(例えば、400℃〜600℃)に加熱して、電極間抵抗を測定した後に、付着したスモークを焼き切って検出能力を回復させる。   Patent Document 1 discloses an electric resistance type smoke sensor in which a pair of comb electrodes are formed on the surface of an insulating substrate, and a heating element is formed on the back surface or inside of the substrate. This sensor makes use of the fact that smoke (fine carbon) has electrical conductivity, and detects a change in electrical resistance value caused by the deposition of smoke between the electrodes serving as the detection unit. As the substrate material, an electrically insulating heat-resistant material is used, and a pair of electrodes is formed by screen-printing on the surface of the flat substrate by pasting a noble metal powder such as Pt or Ag used as an electrode material into a paste. On the back side of the substrate, a heating element is formed in a portion opposite to the electrode, and the detection unit is heated to a desired temperature (for example, 400 ° C. to 600 ° C.) to measure the interelectrode resistance, and then the attached smoke. The detection ability is restored by burning.

また特許文献2には、センサ上の煤堆積を制御するためのセンサエレメントが開示されている。
特許文献2にあるような従来のPM検出センサ1zの基本構造を図13(a)に示すと、アルミナセラミックス等の絶縁基板100z上に一定の間隙を設けて対向する一対の櫛形電極EL11z、EL12zが形成されており、櫛形電極EL11z、EL12zは、リード部113z、123z、端子部114z、124z等を介して、例えば車両電源等を利用した電源部20に接続されている。
電源部20から印加される電圧に応じて、相互に噛み合う櫛形電極EL1z、EL12z間の空間に不均一な電界が形成され、PM検出センサ1zを通過する燃焼排気中に含まれる煤粒子が、櫛形電極EL11z、EL12zに引き寄せられて堆積する。この時の電極間抵抗を、検出部21にて検出することで煤堆積量を測定することができる。
Patent Document 2 discloses a sensor element for controlling soot deposition on the sensor.
A basic structure of a conventional PM detection sensor 1z as disclosed in Patent Document 2 is shown in FIG. 13A. A pair of comb-shaped electrodes EL 11 z facing each other with a certain gap provided on an insulating substrate 100z such as alumina ceramics. EL 12 z are formed, and the comb-shaped electrodes EL 11 z and EL 12 z are connected to the power source unit 20 using, for example, a vehicle power source or the like via the lead portions 113 z and 123 z and the terminal portions 114 z and 124 z. ing.
A non-uniform electric field is formed in the space between the interdigitated electrodes EL 1 1z and EL 12 z in accordance with the voltage applied from the power supply unit 20 and is contained in the combustion exhaust gas passing through the PM detection sensor 1z. Particles are attracted to and deposited on the comb electrodes EL 11 z and EL 12 z. The amount of soot deposition can be measured by detecting the interelectrode resistance at this time by the detection unit 21.

また、特許文献3には、櫛状の測定電極表面に保護層を形成した構成において、製法として、スクリーン印刷の他、CVD、PVDによる方法により、測定電極間の間隔を小さくできることが記載されている。   Patent Document 3 describes that, in a configuration in which a protective layer is formed on the surface of a comb-shaped measurement electrode, as a manufacturing method, the interval between the measurement electrodes can be reduced by a method using CVD or PVD in addition to screen printing. Yes.

従来の電気抵抗式のPM検出センサ1zは、簡易な構成で比較的安定した出力が得られる利点があるものの、絶縁基板100z上にPMが堆積し、一対の櫛形電極EL11z、EL12z間が導通するまでは、電気抵抗値の変化が検出されない。このため、PMの検出を早期に可能とすることが課題であり、特許文献2では、印加電圧を高めて煤粒子を引き付け易くする制御を行っている。
ところが、電荷を帯びたPMは、図13(c)に示すように、電界の強い検出電極EL11z、EL12zの表面に引きつけられるため、その近傍に堆積し易く、検出電極間に露出する絶縁基板100zの表面には堆積し難くなり、プラスに帯電したPMはマイナス極側に、マイナスに帯電したPMはプラス極側に引きつけられる。このため、PMの堆積分布に偏りを生じ、検出部全面を覆うようにPMを均一に堆積させることは容易でない。
The conventional electric resistance type PM detection sensor 1z has an advantage that a relatively stable output can be obtained with a simple configuration. However, PM is deposited on the insulating substrate 100z, and a pair of comb-shaped electrodes EL 11 z and EL 12 z Until the gap becomes conductive, no change in the electrical resistance value is detected. For this reason, it is a subject to enable detection of PM at an early stage, and in Patent Document 2, control is performed to increase the applied voltage to facilitate attracting soot particles.
However, PM was charged, as shown in FIG. 13 (c), since it is attracted to the stronger detection electrode EL 11 z, the surface of the EL 12 z electric field, easily deposited in the vicinity, exposed between the detection electrode Therefore, it is difficult to deposit on the surface of the insulating substrate 100z, and positively charged PM is attracted to the negative electrode side, and negatively charged PM is attracted to the positive electrode side. For this reason, it is not easy to deposit PM uniformly so as to cause a bias in the PM distribution and cover the entire detection unit.

加えて、OBDによる故障診断は、通常、20μm以下の微粒状PMのすり抜けを監視しており、検出電極EL11z、EL12zの間隔がより小さければ、早期検出が可能になるが、特許文献1、2等にあるような従来のスクリーン印刷による方法では、櫛形電極EL11z、EL12zの電極幅や電極間隔に制約があり、図13(b)に示すように、膜厚が数μmから10μm程度、電極間距離が30〜50μm程度に形成され、一般的なスクリーン印刷では、電極間距離を30μm以下に設定することは困難とされており、更なる不感質量の低減を図ることが困難であった。 In addition, failure diagnosis by OBD normally monitors the passage of fine particulate PM of 20 μm or less, and if the interval between the detection electrodes EL 11 z and EL 12 z is smaller, early detection becomes possible. In the conventional screen printing method as described in Documents 1, 2, etc., there are restrictions on the electrode widths and electrode intervals of the comb-shaped electrodes EL 11 z and EL 12 z, and as shown in FIG. The distance between the electrodes is about 30 to 50 μm, and it is difficult to set the distance between the electrodes to 30 μm or less in general screen printing. It was difficult.

また、特許文献3に記載されるように、PVD法、CVD法といった薄膜形成技術を利用することも可能であるが、それでも、電極間隔は20〜40μm程度とされており、DPFをすり抜けるような微粒状PMを検出するには、十分とはいい切れない。また、薄膜形成のための専用の装置が必要であり、生産コストが高くなる虞もある。
さらに、従来の絶縁基板の表面に一対の櫛形電極をスクリーン印刷等により形成する方法では、焼成時の収縮率の変動や、電極形成時の印刷条件等により、電極幅や電極間隔に±5%程度の個体差を生じるので、被測定ガス中のPM量が同一の条件であっても、PM検出センサの個体差によって、電極間にPMが堆積し、抵抗値の変化が検出されるようになるまでの不感質量や、PM量の変化に対する出力の変化量にバラツキを生じていた。
Further, as described in Patent Document 3, it is possible to use a thin film forming technique such as PVD method or CVD method, but the electrode interval is still about 20 to 40 μm, and it passes through the DPF. It is not sufficient to detect fine particulate PM. In addition, a dedicated apparatus for forming a thin film is required, which may increase the production cost.
Furthermore, in the conventional method of forming a pair of comb-shaped electrodes on the surface of an insulating substrate by screen printing or the like, the electrode width and the electrode interval are ± 5% depending on fluctuations in shrinkage during firing, printing conditions during electrode formation, and the like. Since individual differences of the degree occur, even if the amount of PM in the gas to be measured is the same, PM is accumulated between the electrodes due to the individual difference of the PM detection sensor, and a change in resistance value is detected. Variations in the amount of change in output with respect to the dead mass until the change and the change in the amount of PM occurred.

しかし、特許文献1〜3等にあるような従来の絶縁性基体の表面に一対の櫛形電極を形成したPM検出センサの構造では、一旦完成したPM検出センサの電極幅や電極間隔を修正することが不可能であるため、このような個体差を少なくし、さらなる検出精度の向上を図ることが困難であった。   However, in the structure of the PM detection sensor in which a pair of comb-shaped electrodes are formed on the surface of a conventional insulating substrate as described in Patent Documents 1 to 3, etc., the electrode width and electrode interval of the PM detection sensor once completed are corrected. Therefore, it is difficult to reduce such individual differences and further improve detection accuracy.

そこで本発明は、内燃機関の燃焼排気中のPM検出に用いられる電気抵抗式の粒子状物質検出センサにおいて、検出電極の幅や電極間隔の寸法精度の個体差を少なくし、検出精度を向上させると共に、一対の検出電極の間隔をより小さくして、DPFからの微粒状PMのすり抜けといった異常を速やかに検出可能な構成とすること、さらには、そのような構成の粒子状物質検出センサを、複雑な生産工程を必要とすることなく、比較的低コストで製造するための方法を提供することを目的とする。   Therefore, the present invention improves the detection accuracy in an electrical resistance particulate matter detection sensor used for PM detection in combustion exhaust gas of an internal combustion engine by reducing individual differences in the dimensional accuracy of the width of the detection electrode and the electrode interval. In addition, the distance between the pair of detection electrodes is further reduced so that an abnormality such as slipping of the particulate PM from the DPF can be quickly detected, and further, the particulate matter detection sensor having such a structure is provided. An object of the present invention is to provide a method for manufacturing at a relatively low cost without requiring a complicated production process.

請求項1の発明では、内燃機関の燃焼排気を被測定ガスとし、被測定ガス中に設けられ、平板状の絶縁性基体(100)と、導電性材料から成る略平膜状の検出電極(EL、EL)とを具備し、上記絶縁性基体を介して、互いに異なる極性を有する少なくとも一対の上記検出電極が一定間隔で平行に並んだ状態となるように対向せしめて、上記絶縁性基体内部に埋設保持しつつ、上記検出電極の端部を上記絶縁性基体の少なくとも一の側端面に引き出した断面を検出面として用いる粒子状物質検出センサ素子と、上記検出電極間に所定の電圧を印加する電源部(20)と、該電源部からの電圧の印加により上記検出面に露出する上記検出電極端部表面(11、12)に堆積する粒子状物質の量に応じて変化する電気的特性を検出する検出器(21)とを具備し、被測定ガス中の粒子状物質の量を検出する粒子状物質検出センサであって、上記絶縁性基体内部に埋設された上記検出電極の平面部に対して直交する基準面に対して所定の傾斜面形成角度(0<θ≦45°)で傾斜する傾斜面を形成し、当該傾斜面を上記検出面とすることで、当該検出面に沿った上記検出電極間の距離(T10)を所定の目標値(T10TRG)に調整したことを特徴とする粒子状物質検出センサ。 According to the first aspect of the present invention, the combustion exhaust gas of the internal combustion engine is used as a gas to be measured, and is provided in the gas to be measured, and is provided with a flat insulating substrate (100) and a substantially flat membrane-like detection electrode ( EL 1 , EL 2 ), and at least a pair of the detection electrodes having different polarities are arranged to face each other in parallel with each other through the insulating substrate, and the insulating property A predetermined voltage is applied between the detection electrode and a particulate matter detection sensor element that uses a cross-section in which the end of the detection electrode is pulled out to at least one side end surface of the insulating substrate as a detection surface while being embedded and held inside the substrate. And an electric power that changes in accordance with the amount of particulate matter deposited on the detection electrode end surface (11, 12) exposed to the detection surface by application of a voltage from the power supply unit. To detect dynamic characteristics A particulate matter detection sensor for detecting the amount of particulate matter in the gas to be measured, with respect to the flat portion of the detection electrode embedded in the insulating substrate. By forming an inclined surface inclined at a predetermined inclined surface forming angle (0 <θ ≦ 45 °) with respect to an orthogonal reference surface, and using the inclined surface as the detection surface, the detection along the detection surface is performed. A particulate matter detection sensor, wherein a distance (T 10 ) between electrodes is adjusted to a predetermined target value (T 10TRG ).

請求項2の発明では、上記検出面に沿った検出電極間の距離が2μm以上20μm以下である。 In the invention of claim 2, the distance between the detection electrodes along the detection surface is 2 μm or more and 20 μm or less.

請求項3の発明では、略平板状の絶縁性基体を介して対向する一対の略平膜状の検出電極を具備して、該検出電極の端部を上記絶縁性基体の少なくとも一の側端面に引き出した断面を検出面とし、該検出面に露出する上記一対の検出電極端部表面に堆積する粒子状物質の量に応じて変化する電気的特性によって被測定ガス中の粒子状物質の量を検出する粒子状物質検出センサの製造方法であって、少なくとも、絶縁性耐熱材料を用いて略平板状の絶縁性基体を形成する絶縁性基体成形工程と、該絶縁性基体の表面に、導電性材料を用いて略平膜状の検出電極を形成する検出電極形成工程と、該検出電極を形成した絶縁性基体を積層し、少なくとも、一対の上記検出電極が上記絶縁性基体を介して対向する一体の粒子状物質検出センサ前駆体(1PRE)を形成する前駆体形成工程と、上記検出電極の断面が露出するように上記粒子状物質センサ前駆体の端部に所定の傾斜面形成角度(θ)で傾斜面を形成し、当該傾斜面を上記検出面とし、当該検出面に沿った上記一対の検出電極間の距離(T10)を前記絶縁性基体(100)の板厚に等しい調整前電極間距離(T10PRE)の1/cosθ倍とすることで、所定の目標値(T10TRG)に調整する電極間距離調整工程と、を具備することを特徴とする。 According to a third aspect of the present invention, there is provided a pair of substantially flat film-like detection electrodes opposed via a substantially flat insulating base, and the end of the detection electrode is used as at least one side end face of the insulating base. The amount of particulate matter in the gas to be measured depends on the electrical characteristics that change according to the amount of particulate matter deposited on the surface of the pair of detection electrodes exposed on the detection surface. A method for producing a particulate matter detection sensor for detecting an insulating substrate, wherein at least an insulating substrate forming step of forming a substantially flat insulating substrate using an insulating heat-resistant material, and the surface of the insulating substrate is electrically conductive. A detection electrode forming step of forming a substantially flat membrane-like detection electrode using a conductive material and an insulating substrate on which the detection electrode is formed are stacked, and at least a pair of the detection electrodes face each other with the insulating substrate interposed therebetween Integrated particulate matter detection sensor precursor ( A precursor formation step of forming a PRE), to form an inclined surface on the end portion of the particulate matter sensor precursor as the cross section of the detection electrode is exposed at a predetermined incline forming an angle (theta), the inclined The surface is the detection surface, and the distance (T 10 ) between the pair of detection electrodes along the detection surface is 1 / the pre-adjustment electrode distance (T 10PRE ) equal to the plate thickness of the insulating substrate (100). and an inter-electrode distance adjusting step of adjusting to a predetermined target value (T 10TRG ) by setting it to cos θ times.

請求項4の発明では、上記電極間距離調整工程において、一対の上記検出電極間に配設された上記絶縁性基体の板厚を目標値の70%〜100%、即ち、マイナス目の公差に設定すると共に、上記粒子状物質検出センサ前駆体を作製後に、実際の調整前電極間距離(T10PRE)の計測結果に応じて上記傾斜面形成角度を決定する。 In the invention according to claim 4, in the inter-electrode distance adjusting step, the thickness of the insulating substrate disposed between the pair of detection electrodes is set to 70% to 100% of the target value, that is, a minus tolerance. setting while, after producing the particulate matter detection sensor precursors, determining the incline forming an angle in accordance with the actual adjustment before the inter-electrode distance (T 10PRE) measurement result.

請求項5の発明では、上記絶縁性基体の板厚分布から、幾つかのグループにランク分けして、各ランクに対して上記傾斜面形成角度(θ)を設定する。 According to the invention of claim 5, the inclined surface forming angle (θ) is set for each rank by dividing into several groups from the plate thickness distribution of the insulating base.

請求項6の発明では、上記調整前検出電極間距離となる前記絶縁性基体の板厚(T 10PRE )が所定の目標値以上である場合には、上記傾斜面形成角度(θ)を0°とし、上記絶縁性基体の板厚が所定の目標値より薄い場合には、上記傾斜面形成角度(θ)を0°より大きく45°以下とする。 In the invention of claim 6, when the plate thickness (T 10PRE ) of the insulating substrate, which is the distance between the detection electrodes before adjustment , is equal to or larger than a predetermined target value, the inclined surface forming angle (θ) is set to 0 °. When the plate thickness of the insulating substrate is thinner than a predetermined target value, the inclined surface forming angle (θ) is set to be larger than 0 ° and not larger than 45 °.

請求項1の発明によれば、上記電源部から上記検出電極間に電圧を印加したときに、上記絶縁性基体内部に埋設された上記検出電極間に発生した電界により、上記検出面において上記検出電極表面のみならず上記絶縁性基体の表面が誘電分極により分極され、上記検出面において、被測定ガス中に含まれる粒子状物質が速やかに、かつ、均一に堆積するため、早期に不感期間を解消することができる。加えて、上記傾斜面形成角度を調整することで上記検出面に沿った上記検出電極間の距離極めて精度良く目標値に調整されているので被測定ガス中の粒子状物質が堆積して上記検出部によって電気的特性が検出可能になるまでの不感期間を安定化することが可能となり、また、被測定ガス中の粒子状物質の堆積に伴う上記検出部の出力変化を一定にすることが可能となるので、個体差が少なく、信頼性の高い粒子状物質検出センサが実現できる。 According to the first aspect of the present invention, when the voltage is applied between the detection electrodes from the power supply unit, the detection is performed on the detection surface by the electric field generated between the detection electrodes embedded in the insulating base. Not only the electrode surface but also the surface of the insulating substrate is polarized by dielectric polarization, and the particulate matter contained in the gas to be measured accumulates quickly and uniformly on the detection surface. Can be resolved. Additionally, since the distance between the detection electrodes along said detection plane by adjusting the incline forming angle is adjusted very accurately target the particulate matter in the gas to be measured is deposited above It is possible to stabilize the dead period until electrical characteristics can be detected by the detection unit, and to make the change in output of the detection unit accompanying the accumulation of particulate matter in the gas to be measured constant. Therefore, a particulate matter detection sensor with little individual difference and high reliability can be realized.

請求項2の発明によれば、極めて早期に不感期間が解消されると共に、被測定ガス中に含まれる20μm以下の粒径の粒子状物質の検出が可能となる。 According to the second aspect of the present invention, the dead period is eliminated very early, and particulate matter having a particle diameter of 20 μm or less contained in the gas to be measured can be detected.

請求項3の発明によれば、上記絶縁性基体の板厚にバラツキがあっても、上記傾斜面を形成することで、上記検出面における電極間距離を極めて精度良く調整することが可能となり、個体差を少なくした信頼性の高い粒子状物質検出センサを製造することができる。 According to the invention of claim 3, even if the thickness of the insulating substrate varies, it is possible to adjust the inter-electrode distance on the detection surface with extremely high accuracy by forming the inclined surface. A highly reliable particulate matter detection sensor with reduced individual differences can be manufactured.

請求項4の発明によれば、上記検出面における電極間距離を極めて目標値に近い値に調整可能となる。 According to the invention of claim 4, the inter-electrode distance on the detection surface can be adjusted to a value very close to the target value.

個々の製品毎に上記傾斜面形成角度θの設定値を変えることもできるが、作業効率を低下させる虞もあるが、請求項5の発明によれば、各ランクに対して傾斜面形成角度θを設定することにより、比較的高率良く、しかも極めて高い精度で電極間距離T 10 を目標値に近い一定の値に調整することができる。 Although it is possible to change the set value of the inclined surface forming angle θ for each individual product, there is a possibility that the working efficiency may be lowered. According to the invention of claim 5 , the inclined surface forming angle θ is assigned to each rank. by setting a relatively good efficiency, yet it is possible to adjust the distance between electrodes T 10 to a constant value close to the target value with very high accuracy.

請求項6の発明によれば、 元々の検出電極間距離の1.0倍から√2倍の範囲で、任意に調整することが可能となり、上記PM検出センサの製造過程で不可避的に発生する上記検出電極間の距離のバラツキを、極めて小さくし個体差を少なくすることができる。 According to the sixth aspect of the present invention, it is possible to arbitrarily adjust in the range of 1.0 to √2 times the original distance between the detection electrodes, which is inevitably generated in the manufacturing process of the PM detection sensor. The variation in the distance between the detection electrodes can be made extremely small and individual differences can be reduced.

本発明の第1の実施形態におけるPM検出センサの概要を示し、(a)は、傾斜面形成前のPM検出センサの平面図、(b)は、その要部断面図、(c)は、傾斜面形成後のPM検出センサ及び全体構成を示す平面図、(d)は、その要部断面図。The outline | summary of the PM detection sensor in the 1st Embodiment of this invention is shown, (a) is a top view of PM detection sensor before inclined surface formation, (b) is the principal part sectional drawing, (c), The top view which shows PM detection sensor and the whole structure after inclined surface formation, (d) is the principal part sectional drawing. 図1のPM検出センサの要部詳細を示し、(a)は、傾斜面形成前のPM検出センサの要部拡大断面図、(b)は、傾斜面形成後のPM検出センサの要部拡大断面図。FIG. 1 shows details of a main part of the PM detection sensor of FIG. 1, (a) is an enlarged cross-sectional view of the main part of the PM detection sensor before forming the inclined surface, and (b) is an enlarged main part of the PM detection sensor after forming the inclined surface. Sectional drawing. 本発明の効果を示す模式図。The schematic diagram which shows the effect of this invention. 比較例と共に本発明の効果を示し、(a)は、比較例1、比較例2、実施例1における既知量のPMを含む被測定ガスに対する出力の変化の違いを示す特性図、(b−1)、(b−2)は、比較例2における個体差を示す特性図、(c−1)、(c−2)は、本発明の実施例1における個体差を示す特性図。The effect of this invention is shown with a comparative example, (a) is a characteristic diagram which shows the difference of the change of the output with respect to the to-be-measured gas containing known amount PM in the comparative example 1, the comparative example 2, and Example 1, (b- 1) and (b-2) are characteristic diagrams showing individual differences in Comparative Example 2, and (c-1) and (c-2) are characteristic diagrams showing individual differences in Example 1 of the present invention. 本発明の第1の実施形態におけるPM検出センサの製造方法を説明するための展開斜視図。FIG. 3 is an exploded perspective view for explaining a method for manufacturing the PM detection sensor according to the first embodiment of the present invention. 図5に続く製造方法の概要を示し、(a−1)は、傾斜面形成前のPM検出センサ前駆体の斜視図、(a−2)は、そのA−Aに沿った断面図、(b−1)は、傾斜面形成後のPM検出センサの斜視図、(b−2)は、そのA−Aに沿った断面図、(c)は、完成したPM検出センサ全体の概要を示す構成図。The outline of the manufacturing method following FIG. 5 is shown, (a-1) is a perspective view of a PM detection sensor precursor before the inclined surface is formed, (a-2) is a cross-sectional view along AA thereof, ( (b-1) is a perspective view of the PM detection sensor after the inclined surface is formed, (b-2) is a cross-sectional view along the line AA, and (c) is an overview of the entire PM detection sensor completed. Diagram. 本発明の第1の実施形態におけるPM検出センサの変形例を示し、(a)は、PM検出センサ前駆体の展開斜視図、(b)は、発熱体の断面図、(c)は、PM検出センサ前駆体の斜視図、(c)は、PM検出センサの斜視図。The modification of the PM detection sensor in the 1st Embodiment of this invention is shown, (a) is a development perspective view of PM detection sensor precursor, (b) is sectional drawing of a heat generating body, (c) is PM The perspective view of a detection sensor precursor, (c) is a perspective view of PM detection sensor. 本発明の第2の実施形態におけるPM検出センサ前駆体展開平面図PM detection sensor precursor development top view in the 2nd embodiment of the present invention 本発明の第2の実施形態における傾斜面形成後のPM検出センサの要部を示し、(a)は、正面図、(b)は、側端面図、(c)は、下面図。The principal part of PM detection sensor after the inclined surface formation in the 2nd Embodiment of this invention is shown, (a) is a front view, (b) is a side end view, (c) is a bottom view. 本発明の第3の実施形態におけるPM検出センサを示し、(a)は、PM検出センサ前駆体の展開斜視図、(b)は、その側端面図、(c)は、傾斜面形成後のPM検出センサの側端面図、(d)は、その下面図。The PM detection sensor in the 3rd Embodiment of this invention is shown, (a) is a development perspective view of PM detection sensor precursor, (b) is the side end view, (c) is after the inclined surface formation Side view of the PM detection sensor, (d) is a bottom view thereof. 本発明の第3実施形態におけるPM検出センサの変形例を示し、(a)は、PM検出センサ前駆体の展開斜視図、(b)は、その側端面図、(c)は、傾斜面形成後のPM検出センサの側端面図、(d)は、その上面図。The modification of the PM detection sensor in 3rd Embodiment of this invention is shown, (a) is a development perspective view of PM detection sensor precursor, (b) is the side end view, (c) is inclined surface formation The side end elevation of the PM detection sensor after, (d) is the top view. 本発明の第4の実施形態におけるPM検出センサの概要を示す平面図。The top view which shows the outline | summary of the PM detection sensor in the 4th Embodiment of this invention. (a)は、比較例として示す従来のPM検出センサの構成図、(b)は、検出部の詳細を示す断面図、(c)は、比較例におけるPMの捕集状態を示す断面図。(A) is a block diagram of the conventional PM detection sensor shown as a comparative example, (b) is sectional drawing which shows the detail of a detection part, (c) is sectional drawing which shows the collection state of PM in a comparative example.

本発明の粒子状物質検出センサ(以下、PM検出センサと略す。)1は、内燃機関の燃焼排気等を被測定ガスとし、検出電極間に堆積するPM量によって変化する電気的特性として抵抗値を検出することによって、被測定ガス中に含まれる粒子状物質(PM)の量を検出するものである。
図1、図2を参照して、本発明の第1の実施形態におけるPM検出センサ1の概要について説明する。
図1(a)、(b)に示すように、1μm以上20μm以下の一定膜厚でPt等の導電性材料を略平膜状に形成した少なくとも一対の検出電極EL11、EL12を、2μm以上20μm以下の一定間隔で平行に並べて略平板状の絶縁性基体100の内部に埋設保持し、これらの検出電極EL11、EL12の端部表面11、12を絶縁性基体100の側端面10に引き出した粒子状物質検出センサ前駆体(以下、PM検出センサ前駆体と略す。)1PREの端面に検出電極EL11、EL12の平面部に直交する基準面に対する角度が0°以上45°以下の範囲で傾斜する所定の傾斜角度θを有する傾斜面を形成し、検出電極間距離T10を傾斜面の角度により微調整したことを特徴とし、PM検出センサ1の製造工程中に発生する個体差を少なくして、検出精度の向上を図ると共に、微細な粒径のPMを効率よく捕集可能として不感期間の短縮を図ろうとするものである。
検出電極EL11、EL12には、傾斜面の形成角度θが変化しても、検出面に露出する電極端部表面11、12の幅Wが一定となるように、傾斜面が形成され得る範囲内において、電極の幅Wを一定とした検出電極調整領域110、120が形成してある。
A particulate matter detection sensor (hereinafter abbreviated as PM detection sensor) 1 according to the present invention uses a combustion exhaust gas of an internal combustion engine as a gas to be measured, and has a resistance value as an electrical characteristic that varies depending on the amount of PM deposited between detection electrodes. By detecting this, the amount of particulate matter (PM) contained in the gas to be measured is detected.
With reference to FIG. 1 and FIG. 2, the outline | summary of PM detection sensor 1 in the 1st Embodiment of this invention is demonstrated.
As shown in FIGS. 1A and 1B, at least a pair of detection electrodes EL 11 and EL 12 each having a constant film thickness of 1 μm or more and 20 μm or less formed of a conductive material such as Pt in a substantially flat film shape is 2 μm. These are arranged in parallel at regular intervals of 20 μm or less and are embedded and held in the substantially flat insulating base 100, and the end surfaces 11 and 12 of these detection electrodes EL 11 and EL 12 are connected to the side end face 10 of the insulating base 100. Particulate matter detection sensor precursor (hereinafter abbreviated as PM detection sensor precursor) 1 drawn to the angle of 0 ° to 45 ° with respect to the reference surface orthogonal to the planar portion of the detection electrodes EL 11 and EL 12 on the end face of the PRE forming an inclined surface having a predetermined inclination angle θ which is inclined in a range of, characterized in that fine adjustment of the detection electrode distance T 10 by the angle of the inclined surface, generated during the production process of the PM detection sensor 1 individual It is intended to improve the detection accuracy by reducing the difference, and to reduce the dead time by efficiently collecting PM with a fine particle size.
In the detection electrodes EL 11 and EL 12 , inclined surfaces can be formed so that the width W of the electrode end surfaces 11 and 12 exposed to the detection surface is constant even if the formation angle θ of the inclined surface changes. Within the range, detection electrode adjustment regions 110 and 120 having a constant electrode width W are formed.

さらに、平行に並んだ複数対の電極EL11、EL12の内、同極性となる電極が並列となるように絶縁性基体100の内部でスルーホール電極112、122を介して接続され、互いに異なる極性の電極は絶縁性を維持するように、互いの電極を回避して検出電極調整領域110、120とスルーホール電極112、122とを接続する電極取り回し部111、121が形成されている。
さらに、図1(c)に示すように、スルーホール電極112、122は、それぞれ検出電極リード部113、123及び電極端子部114、124を介して、外部に設けた制御部2に接続されている。
制御部2は、電源部20と検出部21とによって構成され、電源部20は、検出電極EL11、EL12間に電圧を印加し、PMを捕集し易くする。
なお、便宜上、検出電極EL11をプラス極、検出電極EL12をマイナス極としてあるが、どちらをプラス極とし、マイナス極とするかは任意である。
また、電極取り回し部111、121は、互いに絶縁性を確保しながら、検出電極調整領域110、120とスルーホール電極112、122とを接続するものであれば如何なる配線パターンに形成しても良い。
Further, among a plurality of pairs of electrodes EL 11 and EL 12 arranged in parallel, electrodes having the same polarity are connected via the through-hole electrodes 112 and 122 inside the insulating base 100 so that they are in parallel, and are different from each other. Electrode routing portions 111 and 121 that connect the detection electrode adjustment regions 110 and 120 and the through-hole electrodes 112 and 122 while avoiding each other electrode are formed so that the polar electrodes maintain insulation.
Furthermore, as shown in FIG.1 (c), the through-hole electrodes 112 and 122 are connected to the control part 2 provided outside via the detection electrode lead parts 113 and 123 and the electrode terminal parts 114 and 124, respectively. Yes.
The control unit 2 includes a power supply unit 20 and a detection unit 21, and the power supply unit 20 applies a voltage between the detection electrodes EL 11 and EL 12 to facilitate the collection of PM.
For convenience, the detection electrode EL 11 is a positive pole and the detection electrode EL 12 is a negative pole, but it is arbitrary which is positive and negative.
Further, the electrode routing portions 111 and 121 may be formed in any wiring pattern as long as they connect the detection electrode adjustment regions 110 and 120 and the through-hole electrodes 112 and 122 while ensuring insulation.

図2(a)に示すように、PM検出センサ前駆体1PREの端面に露出する傾斜形成前検出電極端面11PRE、12PREの膜厚がそれぞれ、調整前電極高さT11PRE、T12PRE、傾斜形成前絶縁性基体端面10PREの板厚が調整前電極間距離T10PREであるときに、基準端面に対して、図2(b)に示すように、0°以上45°以下の傾斜面形成角度θで検出面を切削、研磨等により傾斜面を形成した後の電極端面11、12の検出面に沿った方向の膜厚T11、T12、絶縁性基体端面10に設けた検出面に沿った検出電極間距離10は、それぞれ、調整前電極高さT11PRE、T12PRE、調整前電極間距離T10PREの1/cosθ、即ち、傾斜面形成角度θを0°以上、45°以下とすることにより、1.0倍から√2倍の範囲で任意に調整することができる。 As shown in FIG. 2 (a), the film thicknesses of the pre-tilt detection electrode end faces 11 PRE and 12 PRE exposed on the end face of the PM detection sensor precursor 1 PRE are the pre-adjustment electrode heights T 11PRE , T 12PRE , When the plate thickness of the insulating base end face 10 PRE before tilt formation is the pre-adjustment electrode distance T 10PRE , the tilted face is 0 ° or more and 45 ° or less with respect to the reference end face as shown in FIG. Film thicknesses T 11 and T 12 in the direction along the detection surface of the electrode end surfaces 11 and 12 after the inclined surface is formed by cutting, polishing or the like at the formation angle θ, and the detection surface provided on the insulating substrate end surface 10 detecting the inter-electrode distance T 10 along each adjustment before the electrode height T 11PRE, T 12PRE, 1 / cosθ times the unadjusted electrode distance T 10PRE, i.e., inclined surface forming an angle θ of 0 ° or more, 45 ° or less Thus, it can be arbitrarily adjusted in the range of 1.0 to √2.

例えば、目標とする電極間距離T10TRGが10.0μmであるにも拘わらず、実際に形成された絶縁性基体100の膜厚、即ち、調整前電極間距離T10PREが、9.0μmであった場合、約1.11倍にすれば良く、傾斜面形成角度θを約40.6°として傾斜面を形成して、その傾斜面を検出面とすることにより、検出面に露出し、当該検出面に沿った電極間距離T10極めて精度良く10.0μmに調整することができる。 また、本図(a)に示すように、PM検出センサ前駆体1PREの表面は、収縮率の違いや、熱膨張係数の違い等によって、端面に凹凸ができるが、傾斜面を形成する際に、平滑化されるので、検出面にPMが捕集堆積され、検出電極端部表面11、12間の導体経路を形成する際に絶縁性基体端部表面10が立体的な障害となることがない。 また、PM検出時に、被測定ガスの温度が高い場合等、PM検出センサ1が加熱環境下にある場合には、絶縁性基体100よりも熱膨張係数の大きい検出電極EL11、EL12が膨張し、絶縁性基体端部表面10から、検出電極端部表面11、12が外側に向かって突出するので、絶縁性基体端部表面10が立体的な障害となることがない。 これとは逆に、本発明によらず、検出電極端部表面よりも絶縁性基体端部表面が外側に向かって突出している場合には、絶縁性基体端部表面を乗り越えるようにして検出電極間に導電経路が形成されることになるので、不感期間が長くなってしまう。 For example, although the target inter-electrode distance T 10TRG is 10.0 μm, the thickness of the actually formed insulating substrate 100, that is, the pre-adjustment inter-electrode distance T 10 PRE is 9.0 μm. In this case, it may be about 1.11 times, the inclined surface forming angle θ is set to about 40.6 °, the inclined surface is formed , and the inclined surface is used as the detecting surface, so that the exposed surface is exposed . it is possible to adjust the distance between electrodes T 10 along the detection surface in a very accurately 10.0 [mu] m. Further, as shown in FIG. 5A, the surface of the PM detection sensor precursor 1 PRE may be uneven on the end surface due to a difference in shrinkage rate or a difference in thermal expansion coefficient. In addition, since PM is collected and deposited on the detection surface, the insulating substrate end surface 10 becomes a three-dimensional obstacle when forming a conductor path between the detection electrode end surfaces 11 and 12. There is no. Further, when the PM detection sensor 1 is in a heating environment such as when the temperature of the gas to be measured is high at the time of PM detection, the detection electrodes EL 11 and EL 12 having a thermal expansion coefficient larger than that of the insulating substrate 100 are expanded. Since the detection electrode end surfaces 11 and 12 protrude outward from the insulating substrate end surface 10, the insulating substrate end surface 10 does not become a three-dimensional obstacle. On the contrary, regardless of the present invention, when the end surface of the insulating base protrudes outward from the end surface of the detection electrode, the detection electrode is moved over the end surface of the insulating base. Since a conductive path is formed between them, the dead period becomes long.

上述の如く、電極間距離T10が極めて高い精度で調整されているため、電極間にPMが堆積して、抵抗値変化が検出部2によって検出されるようになるまでの不感期間のバラツキが低減される。
また、検出電極EL11、EL12及び絶縁性基体100の厚み方向の断面が検出面として露出しているので、それぞれの膜厚(T11PRE、T12PRE、T10PRE)を薄くすることにより、不感期間の低減を図ることができる。
絶縁性基体100をドクターブレード法等によりシート成形し、検出電極EL11、EL12をスクリーン印刷によって厚膜形成し、これらを積層してPM検出センサ前駆体1PREを形成した場合、それぞれの膜厚(T11PRE、T12PRE、T10PRE)は2μm〜20μmの範囲で任意に調整可能である。
As described above, since the distance between electrodes T 10 is adjusted with extreme precision, the PM is deposited between the electrodes, the resistance value changes varies the dead time to become detected by the detection unit 2 Reduced.
Further, since the cross sections in the thickness direction of the detection electrodes EL 11 , EL 12 and the insulating substrate 100 are exposed as detection surfaces, it is insensitive by reducing the respective film thicknesses (T 11PRE , T 12PRE , T 10PRE ). The period can be reduced.
When the insulating substrate 100 is formed into a sheet by a doctor blade method or the like, the detection electrodes EL 11 and EL 12 are formed into thick films by screen printing, and these are laminated to form the PM detection sensor precursor 1 PRE , each film Thicknesses (T 11PRE , T 12PRE , T 10PRE ) can be arbitrarily adjusted within a range of 2 μm to 20 μm.

図3を参照して、本発明のPM検出センサ1のPM捕集性向上の効果について説明する。検出電極EL11、EL12の間に電源20から電圧を印加すると、絶縁性基体100の外部に露出する検出電極端部表面11、12が分極され、反対の電荷を帯びたPMが検出電極端部表面11、12に捕集される。
このとき、電極端部表面11、12のみならず絶縁性基体100の内部で対向する検出電極EL11、EL12間にも電界が形成されるので、誘電分極により絶縁性基体端部表面10にもPMが電気的に引き寄せられ、検出電極端部表面11、12間に均一にPMが堆積することになり、早期に不感期間が解消される。
With reference to FIG. 3, the effect of improving the PM trapping property of the PM detection sensor 1 of the present invention will be described. When a voltage is applied from the power source 20 between the detection electrodes EL 11 and EL 12, the detection electrode end surfaces 11 and 12 exposed to the outside of the insulating substrate 100 are polarized, and the oppositely charged PM is detected at the detection electrode end. Collected on the part surfaces 11 and 12.
At this time, an electric field is formed not only on the electrode end surfaces 11 and 12 but also between the detection electrodes EL 11 and EL 12 facing each other inside the insulating substrate 100, so that the dielectric substrate polarizes the insulating substrate end surface 10. In addition, PM is electrically attracted and PM is uniformly deposited between the detection electrode end surfaces 11 and 12, and the dead period is eliminated at an early stage.

図4を参照して、比較例と共に本発明の精度向上効果について説明する。本図(a)は、既知量のPM量に対する出力の変化を示し、比較例1として、図13に示した従来の絶縁性基体100z表面に一対の櫛形電極EL11z、EL12Zを形成したPM検出センサ1zの検出特性を示し、比較例2として、上記実施形態で説明したPM前駆体1PREをそのままの状態で使用した場合の検出特性を示し、実施例1として、本発明のPM検出センサ1を用いた場合の検出特性を示す。
なお、本図に用いた、比較例1の電極間距離は、30μm、比較例2の電極間距離は、9.5μm、実施例1の電極間距離は、10.0μmである。
実施例1の不感質量QEMB1が最も少なく、比較例1の不感質量QREF1の1/5程度となっており、本発明のPM検出センサ1が早期に不感期間を解消できることが分かる。
比較例2の不感質量QREF2は、実施例1の不感質量QEMB1よりも多い。これは、上述したように、検出面に凹凸が存在し、導電経路を形成する上で立体的な障害となっているためと推察される。
With reference to FIG. 4, the precision improvement effect of this invention is demonstrated with a comparative example. This figure (a) shows the change of the output with respect to a known amount of PM, and as a comparative example 1, a PM in which a pair of comb electrodes EL 11z and EL 12Z are formed on the surface of the conventional insulating base 100z shown in FIG. The detection characteristics of the detection sensor 1z are shown. As a comparative example 2, the detection characteristics when the PM precursor 1 PRE described in the above embodiment is used as it is are shown. The PM detection sensor of the present invention is shown as an example 1. The detection characteristic when 1 is used is shown.
The interelectrode distance of Comparative Example 1 used in this figure is 30 μm, the interelectrode distance of Comparative Example 2 is 9.5 μm, and the interelectrode distance of Example 1 is 10.0 μm.
The dead mass Q EMB1 of Example 1 is the smallest and is about 1/5 of the dead mass Q REF1 of Comparative Example 1. It can be seen that the PM detection sensor 1 of the present invention can eliminate the dead period at an early stage.
The dead mass Q REF2 of Comparative Example 2 is larger than the dead mass Q EMB1 of Example 1. As described above, this is presumably because the detection surface has irregularities and is a three-dimensional obstacle in forming a conductive path.

本図(b−1)は、PM検出センサ前駆体1PREの電極間距離T10PREの個体差変動を計測した結果であり、本図(b−2)は、電極間距離を調整していない本発明のPM検出センサ前駆体1PREを複数用いて既知のPM量を検出したときの出力変動を調査したものである。
本図(b−1)に示すように、未調整の状態で、PM検出センサ前駆体1PREの電極間距離T10PREは、測定水準数n=125で、平均10.0μm、σ0.125であり、全体として、±5%程度のバラツキであった。
This figure (b-1) is the result of measuring the individual difference variation of the inter-electrode distance T10PRE of the PM detection sensor precursor 1 PRE , and this figure (b-2) does not adjust the inter-electrode distance. The output fluctuation when a known PM amount is detected using a plurality of PM detection sensor precursors 1 PRE of the present invention is investigated.
As shown in this figure (b-1), in the unadjusted state, the electrode distance T10PRE of the PM detection sensor precursor 1PRE is the measurement level number n = 125, the average is 10.0 μm, and σ0.125. As a whole, the variation was about ± 5%.

本図(c−1)は、本発明のPM検出センサ1の電極間距離T10を調査したものであり、本図(c−2)は、電極間距離を調整した本発明のPM検出センサ1を複数用いて既知のPM量を検出したときの出力変動を調査したものである。
なお、本発明の実施例においては、調整前の電極間距離T10PREが、10.0μmより短い場合には、一律の傾斜面形成角度θ=15°で検出面に研磨を施し、10.0μm以上の場合には、傾斜面形成角度θ=0°で、検出面に研磨を施した。
電極間距離調整後の電極間距離T10は、測定水準数n=125、平均10.04μm、σ0.091に改善され、全体として、±3.5%程度のバラツキに低減することができた。
The figure (c-1) is are those of the examination of the inter-electrode distance T 10 of the PM detection sensor 1 of the present invention, the view (c-2) is the PM detection sensor of the present invention to adjust the distance between the electrodes The output fluctuation when a known amount of PM is detected using a plurality of 1 is investigated.
In the embodiment of the present invention, when the inter-electrode distance T 10PRE before adjustment is shorter than 10.0 μm , the detection surface is polished at a uniform inclined surface formation angle θ = 15 °, and 10.0 μm. In the above case, the detection surface was polished with the inclined surface forming angle θ = 0 °.
Electrode distance T 10 after the inter-electrode distance adjustment is determined number of levels n = 125, average 10.04Myuemu, improves to Shiguma0.091, as a whole, could be reduced to variation of about ± 3.5% .

また、予め、未調整の電極間距離T10PRE、即ち、絶縁性基体100の板厚を目標値の70%〜100%、即ち、マイナス目の公差を設定し、PM検出センサ前駆体1PREを作製後に、実際の電極間距離T10PREの計測結果に応じて傾斜面形成角度θを決定することにより、電極間距離T10を極めて目標値に近い値に調整可能となる。
この場合、個々の製品毎に傾斜面形成角度θの設定値を変えることもできるが、作業効率を低下させる虞もあり、絶縁性基体100の板厚分布から幾つかのグループにランク分けして、各ランクに対して傾斜面形成角度θを設定することにより、比較的高率良く、しかも極めて高い精度で電極間距離T10の値を一定に調整することができる。
Further, an unadjusted inter-electrode distance T 10PRE , that is, the plate thickness of the insulating substrate 100 is set to 70% to 100% of the target value, that is, a minus tolerance, and the PM detection sensor precursor 1 PRE is set to after the preparation, by determining the incline forming an angle θ in accordance with the actual inter electrode distance T 10PRE measurement result, it is possible adjust the distance between electrodes T 10 very close to the target value.
In this case, the set value of the inclined surface formation angle θ can be changed for each individual product, but there is a possibility that the working efficiency may be lowered, and it is ranked into several groups based on the plate thickness distribution of the insulating substrate 100. , by setting the inclined surface forming an angle θ with respect to each rank, a relatively good efficiency, yet it is possible to adjust the value of the inter-electrode distance T 10 constant at very high precision.

例えば、絶縁性基体100の側端部における板厚の平均値が9.50μmで、最小値9.00μm、最大値10.00μm、σ0.125であった場合に、各PM検出センサ前駆体1PREを、絶縁性基体100の端部表面における板厚T10PREが9.7〜10.0μmのものをAランク、9.3〜9.7μmのものをBランク、9.0〜9.4μmのものをCランクとし、Aランクは傾斜面形成角度θを17°、Bランクは傾斜面形成角度θを28°、Cランクは傾斜面形成角度θを37°とすることによって、調整後の絶縁性基体100の端部表面における板厚T10を平均値10.03μm、最小値9.82μm、最大値10.15μm、σ0.072まで調整することも可能となる。
本図(b−2)、(c−2)に示すように、本発明によれば、電極間距離T10の変動を小さくすることによって、不感質量の変動ΔQEMB1をΔQREF2より小さくでき、しかも、既知のPM量に対する出力変動ΔVEMB1もΔVREF2より小さくできることが判明した。
For example, when the average value of the plate thickness at the side end portion of the insulating substrate 100 is 9.50 μm, the minimum value is 9.00 μm, the maximum value is 10.00 μm, and σ is 0.125, each PM detection sensor precursor 1 PRE is A rank when the plate thickness T 10PRE at the end surface of the insulating substrate 100 is 9.7 to 10.0 μm, A rank, 9.3 to 9.7 μm is B rank, 9.0 to 9.4 μm The C rank is A, the A rank has an inclined surface formation angle θ of 17 °, the B rank has an inclined surface formation angle θ of 28 °, and the C rank has an inclined surface formation angle θ of 37 °. mean the thickness T 10 at the end surface of the insulating substrate 100 10.03μm, minimum 9.82Myuemu, maximum 10.15Myuemu, it is also possible to adjust to Shiguma0.072.
The figure (b-2), as shown in (c-2), according to the present invention, by reducing the variation of the inter-electrode distance T 10, a variation Delta] Q EMB1 dead weight be less than Delta] Q REF2, Moreover, it has been found that the output fluctuation ΔV EMB1 with respect to the known PM amount can also be made smaller than ΔV REF2 .

図5、図6を参照して、本発明の第1の実施形態におけるPM検出センサ1のより具体的な構成及び、製造方法について説明する。
絶縁性基体100は、絶縁性基体成形工程として、アルミナ、チタニア、スピネル等の絶縁性耐熱材料をドクターブレード法等の公知の方法により、所定の板厚(例えば、焼成後の厚みとして、10μm)で、平板状に形成し、金型等を用いて、長方形に打ち抜いてある。また、必要に応じて、スルーホール電極112、122を形成するための貫通孔が適宜打ち抜いてある。
検出電極EL11、EL12は、検出電極形成工程として、白金等の導体ペーストを用いて、それぞれの電極パターンに応じた形状で、スクリーン印刷等の公知の方法により、絶縁性基体100の表面に印刷形成されている。
このとき、上述の如く、検出電極調整領域110、120は、端面から一定の範囲が、一定幅となるように形成されており、これに接続して、検出電極取り回し部111、121が形成されている。
検出電極EL11、EL12を印刷すると同時に、絶縁性基体100のスルーホール内に導体ペーストが充填され、スルーホール電極112、122が形成される。
検出電極取り回し部111、121、スルーホール電極112、122のそれぞれに接続して、検出電極リード部113、123、及び、検出電極端子部114、124が形成されている。
検出電極EL11、EL12が絶縁性基体10を介して交互に対向するよう積層されている。
さらに、通電により発熱する発熱体を形成すべく、抵抗ペースト及び導体ペースト等を用いて、スクリーン印刷等の公知の方法により、発熱体130及び、発熱体リード部131、132、発熱体端子部133、134が印刷形成されたヒータ部が形成されている。
発熱体130は、検出面が発熱体130よりも熱的に低い位置となるように配設してある。
With reference to FIGS. 5 and 6, a more specific configuration and manufacturing method of the PM detection sensor 1 according to the first embodiment of the present invention will be described.
Insulating substrate 100 is formed into a predetermined plate thickness (for example, 10 μm as a thickness after firing) by a known method such as a doctor blade method using an insulating heat-resistant material such as alumina, titania or spinel as an insulating substrate forming step. Thus, it is formed into a flat plate shape and punched into a rectangle using a mold or the like. In addition, through holes for forming the through-hole electrodes 112 and 122 are appropriately punched as necessary.
The detection electrodes EL 11 and EL 12 are formed on the surface of the insulating substrate 100 by a known method such as screen printing in a shape corresponding to each electrode pattern using a conductive paste such as platinum as a detection electrode forming step. Print formed.
At this time, as described above, the detection electrode adjustment regions 110 and 120 are formed so that a certain range from the end surface has a certain width, and the detection electrode handling portions 111 and 121 are formed by being connected thereto. ing.
At the same time as the detection electrodes EL 11 and EL 12 are printed, the through-holes 112 and 122 are formed by filling the through-holes of the insulating substrate 100 with the conductor paste.
Detection electrode lead portions 113 and 123 and detection electrode terminal portions 114 and 124 are formed so as to be connected to the detection electrode routing portions 111 and 121 and the through-hole electrodes 112 and 122, respectively.
The detection electrodes EL 11 and EL 12 are stacked so as to alternately face each other with the insulating base 10 interposed therebetween.
Further, in order to form a heating element that generates heat when energized, the heating element 130, the heating element lead portions 131 and 132, and the heating element terminal portion 133 are formed by a known method such as screen printing using a resistance paste and a conductive paste. , 134 are formed by printing.
The heating element 130 is disposed so that the detection surface is at a position thermally lower than the heating element 130.

前駆体形成工程として、これらが一体的に積層され、所定の温度で一体的に焼成され、図6(a−1)に示すようなPMセンサ前駆体1PREが形成される。
なお、本実施形態においては、最上層と最下層となる絶縁性基体100の長さを短くし、検出電極端子部114、124及び発熱体端子部133、134が露出するように形成してあるが、これに限定するものではない。
また、本実施形態においては、検出電極EL11、EL12をそれぞれ3層づつ形成した例を示したが、積層数はこれに限定するものではなく、適宜変更可能である、
図6(a−2)に示すように、複数の検出電極EL11、EL12が絶縁性基体10を介して交互に平行に並んで、絶縁性基体内部に埋設され、絶縁性基体の側端面に検出電極端部表面11PRE、12PREが露出した状態となっている。
In the precursor forming step, these are integrally laminated and integrally fired at a predetermined temperature, so that a PM sensor precursor 1 PRE as shown in FIG. 6A- 1 is formed.
In the present embodiment, the length of the insulating base 100 that is the uppermost layer and the lowermost layer is shortened so that the detection electrode terminal portions 114 and 124 and the heating element terminal portions 133 and 134 are exposed. However, the present invention is not limited to this.
Further, in the present embodiment, the example in which the detection electrodes EL 11 and EL 12 are formed in three layers each is shown, but the number of stacked layers is not limited to this, and can be changed as appropriate.
As shown in FIG. 6 (a-2), a plurality of detection electrodes EL 11 and EL 12 are alternately arranged in parallel via the insulating base 10 and embedded in the insulating base, and the side end face of the insulating base The detection electrode end surfaces 11 PRE and 12 PRE are exposed.

さらに、焼成後のPM検出センサ前駆体1PREの絶縁性基体100の厚みに応じて、目標とする検出電極間距離T10に一致させるように、傾斜面形成角度θが算出され、検出電極間距離調整工程として、検出面が所定の傾斜面形成角度θで切削、研磨等の方法により形成され、本図(b−1)、(b−2)に示すように、検出面に検出電極端部表面11、12が所定の電極間距離T10を隔てて交互に対向することになる。 Further, the inclined surface forming angle θ is calculated according to the thickness of the insulating substrate 100 of the PM detection sensor precursor 1 PRE after firing so as to coincide with the target detection electrode distance T10, and the detection electrode distance is calculated. As the adjustment step, the detection surface is formed by a method such as cutting and polishing at a predetermined inclined surface forming angle θ, and as shown in FIGS. (B-1) and (b-2), the detection electrode end portion is formed on the detection surface. surface 11 and 12 will be opposed alternately at a distance T 10 between predetermined electrode.

このようにして、できあがったPM検出センサ1には、制御部2に設けられた電源部20及び、検出部21が接続される。
センサ電源部201は、検出電極EL11、EL12間に電圧を印加し、検出面に電界を発生され、その周囲に存在する被測定ガス中のPMを静電気力によって引き寄せることができる。
検出部21は、検出電極端部表面11、12間に堆積するPM量によって変化する抵抗値を計測し、被測定ガス中に含まれるPM量を検出することができる。
発熱体端子部133、134は、ヒータ通電線135、136を介してヒータ制御部202に接続され、検出電極端部表面11、12間に堆積したPMを燃焼除去したり、検出抵抗を安定化するために一定温度に加熱したりするために、必要に応じて通電が行われる。なお、PM検出センサ1は、図略の保護カバーに覆われた状態でハウジングに保持され、検出電極端部表面11、12が被測定ガス流路内に載置される。
In this way, the power detection unit 20 and the detection unit 21 provided in the control unit 2 are connected to the PM detection sensor 1 thus completed.
The sensor power supply unit 201 applies a voltage between the detection electrodes EL 11 and EL 12 , generates an electric field on the detection surface, and can attract PM in the measurement gas existing around the detection surface by electrostatic force.
The detection unit 21 can measure the resistance value that varies depending on the amount of PM deposited between the detection electrode end surfaces 11 and 12, and can detect the amount of PM contained in the gas to be measured.
The heating element terminal portions 133 and 134 are connected to the heater control unit 202 via heater energization wires 135 and 136 to burn and remove PM deposited between the detection electrode end surfaces 11 and 12 and stabilize the detection resistance. In order to heat to a certain temperature in order to do so, energization is performed as necessary. The PM detection sensor 1 is held by the housing in a state of being covered by a protective cover (not shown), and the detection electrode end surfaces 11 and 12 are placed in the gas flow path to be measured.

図7を参照して、本発明の第1の実施形態における変形例としてPM検出センサ1aについて説明する。
上記実施形態においては、発熱体130を絶縁性基体100の表面に平面的に印刷形成し、積層した例について説明したが、本実施形態においては、検出電極EL11、EL12を形成した層と同層に発熱体130aを印刷形成し、絶縁性基体100を貫通するスルーホール内に発熱体130b、130cを形成して、これを積層することにより本図(b)に示すように、立体的に配設した点が相違し、各検出電極EL11、EL12の構成は上記実施形態と同様である。
本実施形態においても、本図(c)、(d)に示すように、傾斜面形成角度θを形成することにより、検出面に露出する検出電極端部表面11、12及び絶縁性基体端部表面11の厚みを調整し、電極間距離T10を精度良く一定にすることができ、上記実施形態と同様の効果が発揮できる。
With reference to FIG. 7, a PM detection sensor 1a will be described as a modification of the first embodiment of the present invention.
In the above-described embodiment, the example in which the heating element 130 is planarly printed and formed on the surface of the insulating substrate 100 and stacked has been described. However, in this embodiment, the layer on which the detection electrodes EL 11 and EL 12 are formed The heating element 130a is printed and formed on the same layer, and the heating elements 130b and 130c are formed in the through holes that penetrate the insulating substrate 100, and these are laminated, as shown in FIG. The configuration of each of the detection electrodes EL 11 and EL 12 is the same as that of the above embodiment.
Also in the present embodiment, the detection electrode end surfaces 11 and 12 exposed to the detection surface and the insulating base end are formed by forming the inclined surface forming angle θ as shown in FIGS. and adjusting the thickness of the surface 11, the distance between electrodes T 10 can be accurately fixed, the same effect as the above embodiment can be exhibited.

また、本実施形態において、発熱体130aを毎層に形成した例を示したが、発熱量に応じて発熱体130aの形成を適宜間引いて、スルーホール内の発熱体130b、130cを介して接続するようにしても良い。
さらに、上記実施形態においては、検出電極リード部113、123、検出電極端子部114、124を同一層に形成した例を示したが、本図(a)に示すように、検出電極の極性に応じて、検出電極リード部113、検出電極端子部114と、検出電極リード部123、検出電極端子部124とを別の層に分けて形成しても良い。電源部20及び検出部21への配線の都合等により、リード部及び、端子部をどのように配設するかは適宜選択可能である。
Further, in the present embodiment, the example in which the heating element 130a is formed in each layer is shown, but the formation of the heating element 130a is appropriately thinned according to the amount of generated heat, and is connected via the heating elements 130b and 130c in the through holes. You may make it do.
Furthermore, in the above embodiment, the example in which the detection electrode lead portions 113 and 123 and the detection electrode terminal portions 114 and 124 are formed in the same layer is shown. However, as shown in FIG. Accordingly, the detection electrode lead portion 113, the detection electrode terminal portion 114, the detection electrode lead portion 123, and the detection electrode terminal portion 124 may be formed in different layers. How to arrange the lead part and the terminal part can be selected as appropriate depending on the convenience of wiring to the power supply part 20 and the detection part 21.

図8、図9を参照して、本発明の第2の実施形態におけるPM検出センサ1bについて説明する。
上記実施形態においては、絶縁性基体100内に埋設した一対の検出電極EL11、EL12の端部表面11、12を、絶縁性基体100の一の端部表面10に引き出した構成について説明したが、本実施形態においては、略直方体に形成した絶縁性基体100の両側端部表面10b1、10b3及び底面10b2の三方向に検出電極端部表面を引き出した点が相違する。
本実施形態において、図8に示すように、検出電極調整領域110b1、110b2、110b3、120b1、120b2、120b3においては、絶縁性基体100内に埋設される部分の幅が一定となるように形成されているので、図9に示すように、検出面1、検出面2、検出面3の3方向に傾斜面を形成したときに、露出する検出電極端部表面11b1、11b2、11b3、12b1、12b2、12b3がそれぞれ絶縁性基体100によって分離された状態となっており、各検出電極端部表面の幅Wを一定に保ちながら、電極間距離T10を精度良く調整することができる。
本実施形態においては、上記実施形態と同様の効果に加え、検出面が3方向に存在するので、被測定流路に載置する際の方向性に自由度が生まれ、さらにPM検出センサとしての信頼性が高くなる。
A PM detection sensor 1b according to the second embodiment of the present invention will be described with reference to FIGS.
In the above-described embodiment, the configuration in which the end surfaces 11 and 12 of the pair of detection electrodes EL 11 and EL 12 embedded in the insulating substrate 100 are drawn out to the end surface 10 of the insulating substrate 100 has been described. However, the present embodiment is different in that the detection electrode end surface is drawn out in the three directions of the side end surfaces 10 b1 and 10 b3 and the bottom surface 10 b2 of the insulating base 100 formed in a substantially rectangular parallelepiped.
In the present embodiment, as shown in FIG. 8, the detection electrode adjustment regions 110 b 1, 110 b 2, 110 b 3, 120 b 1, 120 b 2, and 120 b 3 are formed so that the width of the portion embedded in the insulating substrate 100 is constant. Therefore, as shown in FIG. 9, when the inclined surfaces are formed in the three directions of the detection surface 1, the detection surface 2, and the detection surface 3, the exposed detection electrode end surfaces 11 b1 , 11 b2 , 11 b3 , 12 b1 , 12 b2 , and 12 b3 are separated from each other by the insulating substrate 100, and the interelectrode distance T 10 is accurately adjusted while keeping the width W of each detection electrode end surface constant. Can do.
In the present embodiment, in addition to the same effects as in the above embodiment, since the detection surface exists in three directions, a degree of freedom is created in the directionality when placed in the measured flow path, and as a PM detection sensor Increased reliability.

図10を参照して、本発明の第3の実施形態におけるPM検出センサ1cについて説明する。
上記実施形態においては、一の絶縁性基体100の表面に検出電極EL11、EL12と検出電極リード部113、123を形成した例を示したが、本実施形態においては、絶縁性基体100の外周を多角形に形成し、各辺に向かって端部が露出するように検出電極調整領域110c、110c、110c、110c、120c、120c、120c、120cを引き出すように検出電極EL11c、EL12cを形成し、これらを交互に積層し、さらに、検出電極リード部113c、123cを、絶縁性基体100を貫通するスルーホール電極によって構成して、検出電極EL11、EL12の平面方向に直交するような方向に引き伸ばして、絶縁性基体100の最上層の表面に検出電極端子部114c、124cを形成した点が相違する。
さらに、それぞれの検出電極EL11、EL12の同極を接続するスルーホール電極112、122と、反対極となる検出電極取り回し部121c、111cを貫通する位置では各スルーホール電極112、122と反対極の検出電極取り回し部121c、111cとの絶縁性を確保すべく空隙が設けてある。
With reference to FIG. 10, a PM detection sensor 1c according to a third embodiment of the present invention will be described.
In the above embodiment, the example in which the detection electrodes EL 11 and EL 12 and the detection electrode lead portions 113 and 123 are formed on the surface of one insulating substrate 100 is shown. However, in this embodiment, the insulating substrate 100 The outer periphery is formed in a polygonal shape, and the detection electrode adjustment regions 110c 1 , 110c 2 , 110c 3 , 110c 4 , 120c 1 , 120c 2 , 120c 3 , 120c 4 are drawn out so that the ends are exposed toward each side. The detection electrodes EL 11 c and EL 12 c are formed on the electrodes, and these are alternately stacked. Further, the detection electrode lead portions 113 c and 123 c are constituted by through-hole electrodes penetrating the insulating substrate 100, thereby detecting the detection electrode EL. 11 , the electrode 12 is extended in a direction orthogonal to the planar direction of the EL 12 , and the detection electrode terminal portion 114c is formed on the surface of the uppermost layer of the insulating substrate 100. , 124c are different.
Furthermore, the through-hole electrodes 112 and 122 that connect the same polarity of the respective detection electrodes EL 11 and EL 12 , and the through-hole electrodes 112 and 122 that are opposite to the through-hole detection electrodes 121 c and 111 c are opposite to the through-hole electrodes 112 and 122. A gap is provided in order to ensure insulation from the detection electrode handling parts 121c and 111c.

また、本実施形態においては、発熱体130cを検出電極EL11、EL12に対して基端側となるように配設して、発熱体リード部131c、133cを、絶縁性基体100を貫通するスルーホール電極によって構成し、発熱体130cを形成した面に直交する方向に引き伸ばしてある。
加えて、本実施形態においては、傾斜面形成角度θは、PM検出センサ1cの検出面が先端側に向かって先細りとなるような角度で形成されている。
このような構成とすることによって、上記実施形態と同様、電極間隔T10を精度良く調整し、不感質量のバラツキを低減する効果に加え、多角形状に形成した絶縁性基体100の各辺に検出面を形成することができるので、PM検出センサ1cを被測定ガスの流れに対する方向を特定することなく載置することが可能となる。
また、本実施形態においては、多角形として、絶縁性基体100を正方形に形成した例を示したが、多角形の形状は、三角形でも、五角形でも、六角形でも、十二角形でも任意の形状に適宜変更可能であり、各辺に向かって検出電極端部11c1〜n、12c1〜nが露出するように検出電極EL11c、EL12cを形成できる。
Further, in the present embodiment, the heating element 130c is disposed on the proximal end side with respect to the detection electrodes EL 11 and EL 12 , and the heating element lead portions 131c and 133c penetrate the insulating base 100. It is composed of a through-hole electrode and is extended in a direction perpendicular to the surface on which the heating element 130c is formed.
In addition, in the present embodiment, the inclined surface formation angle θ is formed such that the detection surface of the PM detection sensor 1c tapers toward the tip side.
With such a configuration, as in the above embodiment, the electrode interval T 10 accurately adjusted, in addition to the effect of reducing the variation of the dead weight, detected on each side of the insulating substrate 100 formed in a polygonal shape Since the surface can be formed, the PM detection sensor 1c can be placed without specifying the direction with respect to the flow of the gas to be measured.
Further, in the present embodiment, an example in which the insulating base 100 is formed in a square as a polygon has been shown, but the polygon may have any shape such as a triangle, a pentagon, a hexagon, a dodecagon, and the like. The detection electrodes EL 11c and EL 12c can be formed such that the detection electrode ends 11c 1 to n and 12c 1 to n are exposed toward each side.

なお、本実施形態において、検出電極リード部113c、123c及び発熱体リード部131c、132cを絶縁性基体100cに設けたスルーホール内に電極ペーストを充填し、スルーホール電極を形成したものを複数枚積層した例を示したが、検出電極リード部113c、123c及び発熱体リード部131c、132cをリード線によって構成し、貫通孔を設けた絶縁性基体100cを押出成形により軸方向に延びる多角柱状に形成して、貫通孔にリード線を挿入し、絶縁性基体100cの先端部に検出電極EL11c、EL12cを形成し積層した検出層を接続するようにしても良い。 In the present embodiment, the detection electrode lead portions 113c and 123c and the heating element lead portions 131c and 132c are filled with an electrode paste in a through hole provided in the insulating substrate 100c, and a plurality of through hole electrodes are formed. Although the laminated example is shown, the detection electrode lead portions 113c and 123c and the heating element lead portions 131c and 132c are constituted by lead wires, and the insulating substrate 100c provided with the through holes is formed into a polygonal column shape extending in the axial direction by extrusion molding. Then, a lead wire may be inserted into the through hole, and the detection electrodes EL 11 c and EL 12 c may be formed at the tip of the insulating substrate 100 c to connect the stacked detection layers.

図11を参照して、本発明の第3の実施形態におけるPM検出センサの変形例1dについて説明する。
上記第3の実施形態におけるPM検出センサ1cは、発熱体130cが、検出電極EL11c、EL12cを積層した層の基端側に配設された例を示したが、本実施形態においては、発熱体130dが、検出電極EL11c、EL12cを積層した層の先端側に配設された点が相違する。
本実施形態においては、傾斜面形成角度θは、PM検出センサ1dの検出面が基端側に向かって先細りとなるような角度で形成されている。
このような構成とすることによっても、上記第3の実施形態と同様の効果が発揮される。また、本実施形態においては、発熱体130dが、検出電極EL11d、EL12dを交互に積層した層の先端側に形成されているので、発熱体130dで発生した熱を無駄なく検出電極端部表面11d、12d間に堆積したPMを燃焼除去できる。
A modified example 1d of the PM detection sensor according to the third embodiment of the present invention will be described with reference to FIG.
In the PM detection sensor 1c in the third embodiment, the heating element 130c is shown on the base end side of the layer in which the detection electrodes EL 11c and EL 12c are stacked. The difference is that the heating element 130d is disposed on the tip side of the layer in which the detection electrodes EL 11c and EL 12c are stacked.
In the present embodiment, the inclined surface formation angle θ is formed such that the detection surface of the PM detection sensor 1d is tapered toward the base end side.
By adopting such a configuration, the same effects as those of the third embodiment are exhibited. In the present embodiment, the heating element 130d is, the detection electrode EL 11 d, because it is formed on the distal end side of the layer formed by stacking EL 12 d alternately, without waste detected photoelectrically heat generated by the heating element 130d PM accumulated between the extreme surface 11d and 12d can be removed by combustion.

図12を参照して、本発明の第4の実施形態におけるPM検出センサ1eについて説明する。
上記第2、第3の実施形態においては、複数の検出面に露出する検出電極端部表面11b1〜3、11c1〜4、11d1〜4、12b1〜3、12c1〜4、12d1〜4が、絶縁性基体100内部で、一の検出電極取り回し部111b、111c、111d、121b、121c、121dに接続され、一の検出電極EL11d、EL12dを構成するようにした例を示したが、本実施形態のように、第1の検出電極EL11、EL12、第2の検出電極EL11、EL12とをそれぞれ分離独立した状態で形成しても良い。
このように、第1の検出電極EL11、EL12の端部表面11e、12e間に堆積するPM量と、第2の検出電極EL11、EL12の端部表面11e、12e間に堆積するPM量との違いを、それぞれの出力V、Vの違いによって検出することも可能となる。
With reference to FIG. 12, a PM detection sensor 1e according to a fourth embodiment of the present invention will be described.
The second, in the third embodiment, the detection electrode end surface 11b 1 to 3 which is exposed to a plurality of detection surfaces, 11c 1~4, 11d 1~4, 12b 1~3, 12c 1~4, 12d1 example to 4 is an internal insulating substrate 100, one sensing electrode handling unit 111b, 111c, 111d, 121b, 121c, connected to 121d, and so as to constitute one detecting electrode EL 11 d, the EL 12 d However, as in this embodiment, the first detection electrodes EL 11 e 1 , EL 12 e 1 , the second detection electrodes EL 11 e 2 , and EL 12 e 2 are formed separately and independently. You may do it.
Thus, the PM amount deposited between the end surfaces 11e 1 and 12e 1 of the first detection electrodes EL 11 e 1 and EL 12 e 1 and the second detection electrodes EL 11 e 2 and EL 12 e 2 It is also possible to detect the difference from the PM amount deposited between the end surfaces 11e 2 and 12e 2 by the difference between the outputs V 1 and V 2 .

このようにして形成される本発明のPM検出センサは、内燃機関の排気浄化装置に適用されて、排出される粒子状物質の検出に好適に利用される。具体的には、DPFの下流に設置されて、DPFの異常検出に利用することができる。あるいは、DPFの上流に設置されて、DPFに流入する粒子状物質PMを直接検出するシステムに利用することもできる。   The PM detection sensor of the present invention formed as described above is applied to an exhaust gas purification device for an internal combustion engine, and is preferably used for detecting discharged particulate matter. Specifically, it is installed downstream of the DPF and can be used for detecting an abnormality of the DPF. Alternatively, it can be used in a system that is installed upstream of the DPF and directly detects the particulate matter PM flowing into the DPF.

1 PM検出センサ
PRE PM検出センサ前駆体
10 絶縁性基体傾斜端面
10PRE 傾斜形成前絶縁性基体端面
11、12 検出電極傾斜端面
11PRE、12PRE 傾斜形成前電極端面
110、120 検出電極調整領域
111、120 検出電極取り回し領域
112、122 検出電極スルーホール部
113、123 検出電極リード部
114、124 検出電極端子部
2 制御部
20 電源部
21 検出部
θ 検出面形成角度
10TRG 目標値
10 調整後電極間距離
10PRE 調整前電極間距離(絶縁性基体板厚)
11、T12 調整後検出電極高さ
11PRE、T12PRE 調整前検出電極高さ

DESCRIPTION OF SYMBOLS 1 PM detection sensor 1 PRE PM detection sensor precursor 10 Insulating base | substrate inclination end surface 10 Insulating base | substrate end surface 11 and 12 before PRE inclination formation Detection electrode inclination end surface 11 PRE , 12 PRE inclination formation electrode end surface 110, 120 Detection electrode adjustment area | region 111, 120 Detecting electrode routing region 112, 122 Detecting electrode through-hole portion 113, 123 Detecting electrode lead portion 114, 124 Detecting electrode terminal portion 2 Control portion 20 Power supply portion 21 Detecting portion θ Detection surface forming angle
T 10TRG target value T 10 Adjusted electrode distance T 10PRE unadjusted inter-electrode distance (insulating substrate thickness)
Detection electrode height after T 11 , T 12 adjustment T 11PRE , Detection electrode height before T 12 PRE adjustment

特開昭59−197847号公報JP 59-197847 A 特表2008−502892号公報Japanese translation of PCT publication No. 2008-502892 特開2009−85959号公報JP 2009-85959 A

Claims (6)

内燃機関の燃焼排気を被測定ガスとし、被測定ガス中に設けられ、平板状の絶縁性基体(100)と、導電性材料から成る略平膜状の検出電極(EL、EL)とを具備し、上記絶縁性基体を介して、互いに異なる極性を有する少なくとも一対の上記検出電極が一定間隔で平行に並んだ状態となるように対向せしめて、上記絶縁性基体内部に埋設保持しつつ、上記検出電極の端部を上記絶縁性基体の少なくとも一の側端面に引き出した断面を検出面として用いる粒子状物質検出センサ素子と、
上記検出電極間に所定の電圧を印加する電源部(20)と、
該電源部からの電圧の印加により上記検出面に露出する上記検出電極端部表面(11、12)に堆積する粒子状物質の量に応じて変化する電気的特性を検出する検出器(21)とを具備し、
被測定ガス中の粒子状物質の量を検出する粒子状物質検出センサであって、
上記絶縁性基体内部に埋設された上記検出電極の平面部に対して直交する基準面に対して所定の傾斜面形成角度(0<θ≦45°)で傾斜する傾斜面を形成し、当該傾斜面を上記検出面とすることで、当該検出面に沿った上記検出電極間の距離(T10)を所定の目標値(T10TRG)に調整したことを特徴とする粒子状物質検出センサ。
Combustion exhaust from an internal combustion engine is a gas to be measured, provided in the gas to be measured, a flat insulating base (100), and a substantially flat membrane-shaped detection electrode (EL 1 , EL 2 ) made of a conductive material, The at least one pair of the detection electrodes having different polarities are opposed to each other in parallel with each other through the insulating base, and are embedded and held inside the insulating base. A particulate matter detection sensor element that uses, as a detection surface, a cross-section in which an end portion of the detection electrode is drawn to at least one side end surface of the insulating substrate;
A power supply unit (20) for applying a predetermined voltage between the detection electrodes;
A detector (21) for detecting an electrical characteristic that changes according to the amount of particulate matter deposited on the detection electrode end surface (11, 12) exposed to the detection surface by application of a voltage from the power supply unit. And
A particulate matter detection sensor for detecting the amount of particulate matter in a gas to be measured,
An inclined surface is formed which is inclined at a predetermined inclined surface forming angle (0 <θ ≦ 45 °) with respect to a reference plane orthogonal to the plane portion of the detection electrode embedded in the insulating substrate. A particulate matter detection sensor, wherein a distance (T 10 ) between the detection electrodes along the detection surface is adjusted to a predetermined target value (T 10TRG ) by using the detection surface as the detection surface.
上記検出面に沿った上記検出電極間の距離(T10)が2μm以上20μm以下である請求項1に記載の粒子状物質検出センサ。 2. The particulate matter detection sensor according to claim 1, wherein a distance (T 10 ) between the detection electrodes along the detection surface is 2 μm or more and 20 μm or less. 略平板状の絶縁性基体を介して対向する一対の略平膜状の検出電極を具備して、該検出電極の端部を上記絶縁性基体の少なくとも一の側端面に引き出した断面を検出面とし、該検出面に露出する上記一対の検出電極端部表面に堆積する粒子状物質の量に応じて変化する電気的特性によって被測定ガス中の粒子状物質の量を検出する粒子状物質検出センサの製造方法であって、
少なくとも、
絶縁性耐熱材料を用いて略平板状の絶縁性基体を形成する絶縁性基体成形工程と、
該絶縁性基体の表面に、導電性材料を用いて略平膜状の検出電極を形成する検出電極形成工程と、
該検出電極を形成した絶縁性基体を積層し、少なくとも、一対の上記検出電極が上記絶縁性基体を介して対向する一体の粒子状物質検出センサ前駆体(1PRE)を形成する前駆体形成工程と、
上記検出電極の断面が露出するように上記粒子状物質センサ前駆体の端部に所定の傾斜面形成角度(θ)で傾斜面を形成し、当該傾斜面を上記検出面とし、当該検出面に沿った上記一対の検出電極間の距離(T10)を前記絶縁性基体(100)の板厚に等しい調整前電極間距離(T10PRE)の1/cosθ倍とすることで、所定の目標値(T10TRG)に調整する電極間距離調整工程と、を具備することを特徴とする粒子状物質検出センサの製造方法。
A detection surface having a pair of substantially flat film-like detection electrodes facing each other through a substantially flat insulating base, and the end of the detection electrode being drawn to at least one side end face of the insulating base. And particulate matter detection for detecting the amount of particulate matter in the gas to be measured by electrical characteristics that change in accordance with the amount of particulate matter deposited on the surface of the pair of detection electrodes exposed on the detection surface. A method for manufacturing a sensor, comprising:
at least,
An insulating substrate forming step of forming a substantially flat insulating substrate using an insulating heat-resistant material;
A detection electrode forming step of forming a substantially flat film-like detection electrode on the surface of the insulating substrate using a conductive material;
A precursor forming step of laminating the insulating base on which the detection electrode is formed, and forming at least one pair of the detection electrodes with which the particulate detection substance precursor (1 PRE ) is opposed with the insulating base interposed therebetween. When,
An inclined surface is formed at an end of the particulate matter sensor precursor at a predetermined inclined surface forming angle (θ) so that a cross section of the detection electrode is exposed , and the inclined surface is used as the detection surface. A predetermined target value is obtained by setting the distance (T 10 ) between the pair of detection electrodes along the line to be 1 / cos θ times the pre-adjustment electrode distance (T 10PRE ) equal to the plate thickness of the insulating substrate (100). An inter-electrode distance adjusting step of adjusting to (T 10TRG ).
上記電極間距離調整工程において、一対の上記検出電極間に配設された上記絶縁性基体の板厚を目標値の70%〜100%、即ち、マイナス目の公差に設定すると共に、上記粒子状物質検出センサ前駆体を作製後に、実際の上記調整前検出電極間距離(T10PRE)の計測結果に応じて上記傾斜面形成角度を決定する請求項3に記載の粒子状物質検出センサの製造方法。 In the inter-electrode distance adjusting step, 70% to 100% of the target value the thickness of the disposed the above insulating substrate between the pair of the detection electrodes, i.e., the set tolerances negative eyes, the particulate The manufacturing method of the particulate matter detection sensor according to claim 3, wherein after forming the substance detection sensor precursor, the inclined surface forming angle is determined according to the actual measurement result of the pre-adjustment detection electrode distance ( T10PRE ). . 絶縁性基体の板厚分布から、幾つかのグループにランク分けして、各ランクに対して上記傾斜面形成角度(θ)を設定する請求項3または4に記載の粒子状物質検出センサの製造方法。   The particulate matter detection sensor according to claim 3 or 4, wherein the inclined surface forming angle (θ) is set for each rank by ranking into several groups from the plate thickness distribution of the insulating substrate. Method. 上記調整前検出電極間距離となる上記絶縁性基体の板厚が所定の目標値以上である場合には、上記傾斜面形成角度(θ)を0°とし、上記絶縁性基体の板厚が所定の目標値より薄い場合には、上記傾斜面形成角度(θ)を0°より大きく45°以下とする請求項3ないし5のいずれかに記載の粒子状物質検出センサの製造方法。   When the plate thickness of the insulating substrate, which is the distance between the detection electrodes before adjustment, is equal to or greater than a predetermined target value, the inclined surface forming angle (θ) is set to 0 °, and the plate thickness of the insulating substrate is set to a predetermined value. 6. The method for manufacturing a particulate matter detection sensor according to claim 3, wherein the inclined surface forming angle (θ) is set to be greater than 0 ° and equal to or less than 45 ° when the value is less than the target value.
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