JPH0629780B2 - Pyroelectric infrared detector - Google Patents
Pyroelectric infrared detectorInfo
- Publication number
- JPH0629780B2 JPH0629780B2 JP60260034A JP26003485A JPH0629780B2 JP H0629780 B2 JPH0629780 B2 JP H0629780B2 JP 60260034 A JP60260034 A JP 60260034A JP 26003485 A JP26003485 A JP 26003485A JP H0629780 B2 JPH0629780 B2 JP H0629780B2
- Authority
- JP
- Japan
- Prior art keywords
- electrode
- pyroelectric
- infrared
- infrared detector
- substrate
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
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Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
- G01J5/00—Radiation pyrometry, e.g. infrared or optical thermometry
- G01J5/10—Radiation pyrometry, e.g. infrared or optical thermometry using electric radiation detectors
- G01J5/34—Radiation pyrometry, e.g. infrared or optical thermometry using electric radiation detectors using capacitors, e.g. pyroelectric capacitors
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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Spectroscopy & Molecular Physics (AREA)
- Photometry And Measurement Of Optical Pulse Characteristics (AREA)
- Radiation Pyrometers (AREA)
Description
【発明の詳細な説明】 産業上の利用分野 本発明は、集電効果を利用した焦電型赤外検出器に関す
るものである。Description: TECHNICAL FIELD The present invention relates to a pyroelectric infrared detector utilizing a current collecting effect.
従来の技術 物体からの温度に応じて放射される赤外線を利用して物
体を検出したり、その温度を測定したりする赤外線検出
器には、量子効果を利用したものと、赤外線を熱として
検知する熱型のものとがある。熱型の赤外検出器におい
ては焦電効果を利用した焦電型赤外検出器があり、特開
昭５７−２８２２３公報、あるいは特開昭５９−２８６
２９公報等に記載されたものが知られている。2. Related Art Infrared detectors that detect an object using infrared rays emitted according to the temperature from the object or measure the temperature of the object include those that use the quantum effect and those that detect infrared rays as heat. There is a thermal type. Among the thermal infrared detectors, there is a pyroelectric infrared detector utilizing the pyroelectric effect, which is disclosed in JP-A-57-28223 or 59-286.
Those described in Japanese Patent Publication No. 29 etc. are known.
以下、第５図乃至第６図を参照して従来の焦電型赤外検
出器について説明する。第５図は従来の焦電型赤外検出
器の概略断面図であり、１０１は焦電素子、１０２は上
部電極、１０３は熱吸収体、１０４は下部電極、１０５
は半導体単結晶による中空の支持台、１０６は絶縁被膜
である。而して焦電素子１０１は赤外線の照射によって
加熱され、焦電素子１０１の下部に半導体基板１０５が
存在する場合に比べれば、下方への熱伝導による熱の逃
げを防止することができ、感度向上を図ることができる
ようになっている。第６図は従来の焦電型赤外検出器の
他の例を示す概略断面図である。１１０は焦電体結晶、
１１１は上部電極、１１２は下部電極、１１３は導電性
接着剤、１１４は支持台、１１５は中空を示す。この素
子構成は、支持台１１４の周辺部を除いて焦電素子下部
に中空１１５を設け、下方への熱伝導による熱の逃げを
防止することにより、感度向上を図るように構成されて
いる。A conventional pyroelectric infrared detector will be described below with reference to FIGS. 5 to 6. FIG. 5 is a schematic sectional view of a conventional pyroelectric infrared detector. 101 is a pyroelectric element, 102 is an upper electrode, 103 is a heat absorber, 104 is a lower electrode, and 105.
Is a hollow support base made of a semiconductor single crystal, and 106 is an insulating coating. Thus, the pyroelectric element 101 is heated by the irradiation of infrared rays, and as compared with the case where the semiconductor substrate 105 exists below the pyroelectric element 101, it is possible to prevent the heat from escaping due to the downward heat conduction, and the sensitivity is improved. It is possible to improve. FIG. 6 is a schematic sectional view showing another example of a conventional pyroelectric infrared detector. 110 is a pyroelectric crystal,
111 is an upper electrode, 112 is a lower electrode, 113 is a conductive adhesive, 114 is a support, and 115 is hollow. This element structure is configured to improve the sensitivity by providing a hollow 115 below the pyroelectric element excluding the peripheral portion of the support 114 and preventing heat from escaping due to heat conduction downward.
発明が解決しようとする問題点 しかし、第５図のような構成の場合は焦電素子１０１の
下方の半導体基板１０５が除去されているため、熱伝導
による熱の逃げをかなり防止することができるが、依然
絶縁被膜１０６が存在するため、完全には下方への熱の
逃げを防止することができない。また、第６図のような
構成にすると下方への熱の逃げを防止することができる
が、焦電体基板１１０がその周辺部で支持台１１４に接
着固定されているため、その周辺部から熱伝導による熱
の逃げが生じ、感度の低下が生じるとともに、光学系と
組み合わせた場合の視野角（ＦＯＶ）の低下を来すとい
う問題があった。Problems to be Solved by the Invention However, in the case of the configuration shown in FIG. 5, since the semiconductor substrate 105 below the pyroelectric element 101 is removed, heat escape due to heat conduction can be considerably prevented. However, since the insulating film 106 still exists, it is not possible to completely prevent the heat from escaping downward. Further, if the structure as shown in FIG. 6 is used, it is possible to prevent heat from escaping downward, but since the pyroelectric substrate 110 is adhesively fixed to the support base 114 at its peripheral portion, the pyroelectric substrate 110 is prevented from the peripheral portion. There is a problem in that heat is released due to heat conduction, sensitivity is reduced, and a viewing angle (FOV) when combined with an optical system is reduced.
そこで、本発明は、上記問題を解決し、熱伝導による熱
の逃げを防止することにより、感度の向上が図れ、ＦＯ
Ｖ特性の向上が図れる焦電型赤外検出器を提供するもの
である。Therefore, the present invention solves the above problems and prevents the escape of heat due to heat conduction, thereby improving the sensitivity and improving the FO.
A pyroelectric infrared detector capable of improving V characteristics.
問題点を解決するための手段 上記問題点を解決するために、本発明は、焦電体基板
と、前記焦電体基板の第１の面に設けられた赤外線吸収
体を兼ねた第１の電極と、前記焦電体基板の第１の面に
対向した第２の面に設けられた第２の電極と、前記第１
の面の前記第１の電極が設けられていない領域と前記第
２の面の前記第２の電極が設けられていない領域とを連
結する貫通孔と、入射する赤外線を前記第１の電極と前
記第２の電極とで挟まれた領域に集光する赤外線集光レ
ンズとを有し、前記焦電体基板の厚さが、前記第１の電
極と前記第２の電極とで挟まれた領域では、その他の領
域に比べて相対的に薄く設定された焦電型赤外検出器で
ある。Means for Solving the Problems In order to solve the above problems, the present invention provides a first pyroelectric substrate which also serves as an infrared absorber provided on a first surface of the pyroelectric substrate. An electrode, a second electrode provided on a second surface of the pyroelectric substrate facing the first surface, and the first electrode.
A through hole that connects a region of the surface of the second surface where the first electrode is not provided and a region of the second surface where the second electrode is not provided, and an incident infrared ray is used as the first electrode. An infrared condensing lens for condensing light in a region sandwiched by the second electrode, and the thickness of the pyroelectric substrate is sandwiched by the first electrode and the second electrode. In the region, the pyroelectric infrared detector is set to be relatively thin compared to the other regions.
作用 本発明は、上記構成により、焦電型赤外検出器の赤外線
感能領域が赤外線の照射によって加熱された場合、下方
への熱伝導による熱の逃げが防止でき、また、周辺部に
形成した貫通領域により、横方向への熱伝導による熱の
逃げを防止することができる。その結果、感度の向上及
びＦＯＶ特性の向上を図ることができる。Effect of the Invention With the above configuration, when the infrared sensitive region of the pyroelectric infrared detector is heated by the irradiation of infrared rays, heat can be prevented from escaping due to heat conduction downward, and the present invention can be formed in the peripheral portion. Due to the penetrating region, it is possible to prevent heat from escaping due to heat conduction in the lateral direction. As a result, it is possible to improve the sensitivity and the FOV characteristic.
実施例 以下、本発明の実施例を図面に基いて詳細に説明する。
第１図は本発明の焦電型赤外検出器の一実施例を示す平
面図、第２図（ａ），（ｂ）は第１図に示すＸ−Ｘ′断
面図の２つの実施例である。第１図及び第２図（ａ）に
おいて、１は焦電体基板で、その両面に上部電極２及び
下部電極３が形成されている。そして、焦電体基板１の
両面に上部電極２及び下部電極３が形成されている赤外
線感能領域の周辺部に、一部を除いて、即ち、架橋部４
を除いて貫通領域５が形成されている。第２図（ｂ）は
焦電素子の熱容量を低減し、感度向上を図るために、赤
外線感能領域の焦電体基板１の厚さを他の焦電体基板１
の厚さより薄くしている例であり、他の部分は第１図，
第２図（ａ）と同一である。なお、上記電極２として、
赤外線吸収体と導電性薄膜とから構成しても同等の機能
を有することができる。Examples Hereinafter, examples of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a plan view showing an embodiment of a pyroelectric infrared detector of the present invention, and FIGS. 2 (a) and 2 (b) are two embodiments of a sectional view taken along line XX 'shown in FIG. Is. In FIGS. 1 and 2 (a), reference numeral 1 is a pyroelectric substrate on which upper and lower electrodes 2 and 3 are formed. Then, in the peripheral portion of the infrared sensitive region where the upper electrode 2 and the lower electrode 3 are formed on both surfaces of the pyroelectric substrate 1, except for a part thereof, that is, the bridge portion 4
The penetrating region 5 is formed except for. FIG. 2B shows that the thickness of the pyroelectric substrate 1 in the infrared sensitive region is set to be different from that of the other pyroelectric substrate 1 in order to reduce the heat capacity of the pyroelectric element and improve the sensitivity.
It is an example of making it thinner than the thickness of
It is the same as FIG. 2 (a). In addition, as the electrode 2,
Even if it is composed of an infrared absorber and a conductive thin film, it can have the same function.
次に、光学系と組み合わせた場合の本発明の一実施例の
平面図を第３図に、その断面図を第４図に示す。第３図
及び第４図において、焦電体基板１１の両面に上部電極
１２及び下部電極１３が形成され、焦電体基板１１の両
面に上部電極１２及び下部電極１３が形成されている赤
外線感能領域の周辺部に、架橋部１４を除いて貫通領域
１５が形成されている。そして、この焦電型検出器の赤
外線検知領域を赤外線集光レンズ１６の集光領域に配
し、絶縁性接着剤１７及び引き出し電極１８を兼ねた固
定材で赤外線集光レンズ１６と接着固定している。Next, a plan view of an embodiment of the present invention when combined with an optical system is shown in FIG. 3, and a sectional view thereof is shown in FIG. In FIGS. 3 and 4, the upper electrode 12 and the lower electrode 13 are formed on both sides of the pyroelectric substrate 11, and the upper electrode 12 and the lower electrode 13 are formed on both sides of the pyroelectric substrate 11. A penetrating region 15 is formed in the peripheral portion of the functional region except for the bridge portion 14. Then, the infrared detection area of this pyroelectric detector is arranged in the light collection area of the infrared light condensing lens 16, and the infrared light condensing lens 16 is bonded and fixed with a fixing material that also serves as the insulating adhesive 17 and the extraction electrode 18. ing.
次に一実施例について説明する。焦電体基板１として厚
さ30μｍのPbTiO3セラミクス、あるいはLiTaO3結晶１．
５mm×１．５mmを用い、その一方の面に有効感能領域部
として直径１mm、信号取り出し部として０．１mm巾で焦
電体基板１の１つの隅に向かう上部電極２をNiCrを蒸着
することによって形成した。次に、上記焦電体基板１の
他方の面に、上部電極２の有効感能領域に対応した直径
１mmの有効感能領域部と上部電極２の信号取り出し部が
向かう焦電体基板１の隅と反対側の隅に向かう０．１mm
巾の信号取り出し部を持つ下部電極３をＡｌを蒸着する
ことによって形成した。そして、内周径１mm、外周径
１．２mmで、巾０．１mmの架橋部４を４ケ所持つ貫通領
域５に対応したマスクで上記電極形成した焦電体基板１
を覆い、イオンミリングによって貫通領域５の焦電体基
板１を除去した。その結果、このようにして形成した焦
電型赤外検出器において、従来のものに比べ良好な感度
の向上が得られた。Next, an example will be described. As the pyroelectric substrate 1, 30 μm thick PbTiO 3 ceramics or LiTaO 3 crystal 1.
5 mm × 1.5 mm is used, and NiCr is vapor-deposited on one surface of the upper electrode 2 having a diameter of 1 mm as an effective sensitive area and a width of 0.1 mm as a signal extracting portion, which is directed to one corner of the pyroelectric substrate 1. Formed by. Next, on the other surface of the pyroelectric substrate 1, the effective sensitive area portion having a diameter of 1 mm corresponding to the effective sensitive area of the upper electrode 2 and the signal extracting portion of the upper electrode 2 are directed. 0.1mm towards the corner opposite the corner
The lower electrode 3 having the signal extraction portion of the width was formed by depositing Al. Then, the pyroelectric substrate 1 in which the electrodes are formed with a mask corresponding to the through region 5 having four inner diameters of 1 mm, an outer diameter of 1.2 mm and a width of 0.1 mm and four bridge portions 4 is formed.
And the pyroelectric substrate 1 in the penetrating region 5 was removed by ion milling. As a result, in the pyroelectric infrared detector thus formed, a good improvement in sensitivity was obtained as compared with the conventional one.
また、他の実施例として、厚さ10μｍのPbTiO3セラミク
ス、あるいはLiTaO3結晶１mm×１mmを用い、中央部に直
径５００μｍの貫通部のあるマスクで覆った後、イオン
ミリングによって厚さを５μｍまで薄くした。次に、前
記実施例で説明した方法と同様にして、焦電体基板１１
のイオンミリングを施していない側の面には直径300μ
ｍの有効感能領域部、巾50μｍの信号取り出し部を持っ
た上部電極１２としてNiCr電極を、イオンミリングを施
した側の面には下部電極１３としてＡｌまたはNiCrを蒸
着した電極を形成した。次に、内周径300μｍ、外周径5
00μｍ、巾50μｍの架橋部１４を２ケ所持つ貫通領域に
対応したマスクで、上部電極１２を形成してある側の面
を覆い、イオンミリングによって貫通領域１５の焦電体
基板１１を除去した。その後、赤外集光レンズ１６であ
る直径３mmのイマージョンレンズ上に蒸着形成したInの
引き出し電極１８と、上記上部電極１２の信号読み出し
部と熱圧着して導通を図った。同時に、焦電体基板１１
の他の３隅を絶縁性接着剤１７で接着固定した。その
後、リード線１９と２０を形成し、外部への信号取り出
しを図った。その結果熱の逃げの防止による感度の向
上、有効感能領域の薄板化にともなう雑音の低減による
Ｓ／Ｎの向上が図れた。また、ＦＯＶ特性に関しても従
来のものに比べその特性の大巾な改善が得られた。As another embodiment, using PbTiO 3 ceramics having a thickness of 10 μm or LiTaO 3 crystal 1 mm × 1 mm, and covering with a mask having a through portion having a diameter of 500 μm in the central portion, the thickness is increased to 5 μm by ion milling. Thinned. Next, in the same manner as the method described in the above embodiment, the pyroelectric substrate 11
300 μm in diameter on the side not subjected to ion milling
A NiCr electrode was formed as the upper electrode 12 having an effective sensitive area of m and a signal extraction portion having a width of 50 μm, and an electrode having Al or NiCr deposited thereon was formed as the lower electrode 13 on the surface on which the ion milling was performed. Next, inner diameter 300μm, outer diameter 5
The surface of the side where the upper electrode 12 was formed was covered with a mask corresponding to the penetrating region having two bridge portions 14 of 00 μm and width of 50 μm, and the pyroelectric substrate 11 in the penetrating region 15 was removed by ion milling. Then, it aimed and the extraction electrode 18 of I n which is vapor deposited on the immersion lens of 3mm diameter is infrared condenser lens 16, the conduction and the signal reading section and the thermocompression bonding of the upper electrode 12. At the same time, the pyroelectric substrate 11
The other three corners were fixed with an insulating adhesive 17. After that, lead wires 19 and 20 were formed to take out signals to the outside. As a result, it was possible to improve the sensitivity by preventing the escape of heat and improve the S / N ratio by reducing the noise accompanying the thinning of the effective sensitive area. Further, regarding the FOV characteristic, a great improvement in the characteristic was obtained as compared with the conventional one.
なお、上記実施例において、イオンミリングを施した側
の面に上部電極を、イオンミリングを施していない側に
下部電極を形成した場合でも、同様に、従来のものに比
較して、その特性を大幅に改善することができた。In the above example, even when the upper electrode is formed on the surface on which ion milling is performed and the lower electrode is formed on the side on which ion milling is not performed, the characteristics thereof are similarly compared to those of the conventional one. We were able to improve significantly.
発明の効果 以上説明したように、本発明によれば熱伝導による下方
への熱の逃げがなく、また横方向への熱の逃げも激減さ
せることができるため、焦電型赤外検出器としてそのＳ
／Ｎの向上が図れ、またＦＯＶ特性の向上を図ることが
できる。EFFECTS OF THE INVENTION As described above, according to the present invention, there is no escape of heat downward due to heat conduction, and the escape of heat in the lateral direction can be drastically reduced. Therefore, as a pyroelectric infrared detector, That S
/ N can be improved, and the FOV characteristic can be improved.
第１図は本発明の焦電型赤外検出器の一実施例を示す平
面図、第２図（ａ），（ｂ）はその断面図、第３図は赤
外集光レンズと組み合わせた場合の本発明の一実施例を
示す平面図、第４図は第３図の実施例の断面図、第５
図，第６図は各々従来の焦電型赤外検出器の断面図であ
る。 １，１１……焦電体基板、２，１２……上部電極、３，
１３……下部電極、４，１４……架橋部、5,15……貫通
領域、１６……赤外線集光レンズ。FIG. 1 is a plan view showing an embodiment of the pyroelectric infrared detector of the present invention, FIGS. 2 (a) and 2 (b) are sectional views thereof, and FIG. 3 is a combination with an infrared condenser lens. FIG. 4 is a plan view showing an embodiment of the present invention, FIG. 4 is a sectional view of the embodiment of FIG.
FIG. 6 and FIG. 6 are sectional views of a conventional pyroelectric infrared detector. 1, 11 ... Pyroelectric substrate, 2, 12 ... Upper electrode, 3,
13 ... lower electrode, 4, 14 ... bridge part, 5,15 ... penetration area, 16 ... infrared ray condensing lens.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 中村 邦雄 神奈川県川崎市多摩区東三田３丁目10番１ 号 松下技研株式会社内 (56)参考文献 特開 昭60−119426（ＪＰ，Ａ) ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Kunio Nakamura Inventor Kunio Nakamura 3-10-1 Higashisanda, Tama-ku, Kawasaki City, Kanagawa Matsushita Giken Co., Ltd. (56) Reference JP-A-60-119426 (JP, A)
Claims (2)
に設けられた赤外線吸収体を兼ねた第１の電極と、前記
焦電体基板の第１の面に対向した第２の面に設けられた
第２の電極と、前記第１の面の前記第１の電極が設けら
れていない領域と前記第２の面の前記第２の電極が設け
られていない領域とを連結する貫通孔と、入射する赤外
線を前記第１の電極と前記第２の電極とで挟まれた領域
に集光する赤外線集光レンズとを有し、前記焦電体基板
の厚さが、前記第１の電極と前記第２の電極とで挟まれ
た領域では、その他の領域に比べて相対的に薄く設定さ
れた焦電型赤外検出器。1. A pyroelectric substrate, a first electrode provided also on the first surface of the pyroelectric substrate and also serving as an infrared absorber, and opposed to the first surface of the pyroelectric substrate. A second electrode provided on a second surface, an area of the first surface where the first electrode is not provided, and an area of the second surface where the second electrode is not provided A pyroelectric substrate having a through-hole for connecting the infrared ray and an infrared ray condensing lens for condensing the incident infrared ray in a region sandwiched by the first electrode and the second electrode. A pyroelectric infrared detector in which a region sandwiched by the first electrode and the second electrode is set to be relatively thinner than other regions.
とからなる特許請求の範囲第１項記載の焦電型赤外検出
器。2. The pyroelectric infrared detector according to claim 1, wherein the first electrode comprises an infrared absorber and a conductive thin film.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60260034A JPH0629780B2 (en) | 1985-11-20 | 1985-11-20 | Pyroelectric infrared detector |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60260034A JPH0629780B2 (en) | 1985-11-20 | 1985-11-20 | Pyroelectric infrared detector |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS62119419A JPS62119419A (en) | 1987-05-30 |
| JPH0629780B2 true JPH0629780B2 (en) | 1994-04-20 |
Family
ID=17342381
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP60260034A Expired - Lifetime JPH0629780B2 (en) | 1985-11-20 | 1985-11-20 | Pyroelectric infrared detector |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0629780B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH046424A (en) * | 1990-04-24 | 1992-01-10 | Nec Corp | Infrared sensor |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60119426A (en) * | 1983-12-01 | 1985-06-26 | Murata Mfg Co Ltd | Thin film type pyroelectric sensor array |
-
1985
- 1985-11-20 JP JP60260034A patent/JPH0629780B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPS62119419A (en) | 1987-05-30 |
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