JP3858475B2

JP3858475B2 - Infrared detector and infrared detector provided with the same

Info

Publication number: JP3858475B2
Application number: JP27111398A
Authority: JP
Inventors: 祥文渡部; 浩一相澤
Original assignee: Matsushita Electric Works Ltd
Current assignee: Panasonic Electric Works Co Ltd
Priority date: 1998-09-25
Filing date: 1998-09-25
Publication date: 2006-12-13
Anticipated expiration: 2018-09-25
Also published as: JP2000097764A

Description

【０００１】
【発明の属する技術分野】
本発明は、赤外線の吸収に基づく温度変化により、赤外線を検出する赤外線検出素子に関するものである。
【０００２】
【従来の技術】
従来、この種の赤外線検出素子X として、特開平１０−９９４９号に開示されたものが存在する。このものは、雰囲気ガス中に封入される赤外線検出素子であって、図８に示すように、赤外線検出部A 、支持部材B 、第１の対向部材C 、絶縁膜D 、第１の基板E 、第２の対向部材F 、第２の基板G を備えている。
【０００３】
赤外線検出部A は、検出される赤外線を吸収して温度変化する。支持部材B は、複数の梁B₁を延設し、その梁B₁の先端部でもって赤外線検出部A を支持している。第１の対向部材C は、支持部材B から延設されており、雰囲気ガスの平均自由行程よりも小さい空隙C₁を間に有して赤外線検出部A と対向する対向面C₂が設けられている。詳しくは、この第１の対向部材C は、雰囲気ガスの平均自由行程よりも小さく空隙C₁と平行な間隙C₃を間に有して互いに対向する複数の対向部C₄が設けられている。この第１の対向部材C は、絶縁膜D を介して第１の基板E に接合されることにより、対向面C₂とは反対側の反対面C₅が絶縁膜D を介して第１の基板E に対向している。
【０００４】
第２の対向部材F は、支持部材B から連設された第２の基板G から延設されており、雰囲気ガスの平均自由行程よりも小さい空隙F₁を間に有して赤外線検出部A と対向する対向面F₂が設けられている。詳しくは、この第２の対向部材F は、第１の対向部材C と同様に、雰囲気ガスの平均自由行程よりも小さく空隙F₁と平行な間隙F₃を間に有して互いに対向する複数の対向部F₄が設けられている。この第２の対向部材F は、対向面F₂とは反対側の反対面F₅が第２の基板G に対向している。
【０００５】
【発明が解決しようとする課題】
上記した従来の赤外線検出素子にあっては、赤外線検出部A と両対向部材C,F との間の空隙C,F が雰囲気ガスの平均自由行程よりも小さくなっているから、赤外線検出部A から熱エネルギーを伝達された雰囲気ガス分子は、他の雰囲気ガス分子に衝突する前に両対向部材C,F に衝突するから、雰囲気ガス分子同士の衝突に基づく熱エネルギーの伝達が少なくなり、つまり雰囲気ガスへの放熱が少なくなるので、赤外線検出部A での温度変化が赤外線吸収による発熱に基づくものとなるから、赤外線検出感度をより高くすることができるものとなっている。
【０００６】
しかしながら、このものは、第１の対向部材C の反対面C₅が絶縁膜D を介して第１の基板E に対向しているために、第１の対向部材C の反対面C₅から第１の基板E へ向かって放熱されることになり、第１の基板E が、そのものの有する熱容量を飽和させるまで加熱されることになる。そうなると、赤外線検出部A までもが、温度上昇を続けることになって、発熱と放熱とが平衡となる平衡温度になるまでの時間が長くなるので、赤外線吸収に基づく発熱による温度変化の検出に時間がかかることになって、赤外線を迅速に検出することができなくなってしまう。
【０００７】
さらに、このものは、第２の対向部材F の対向面F₂とは反対側の反対面F₅が第２の基板G に対向しているために、第２の対向部材F の反対面F₅から第２の基板G へ向かって放熱されることになり、第２の基板G が、そのものの有する熱容量を飽和させるまで加熱されることになる。そうなると、赤外線検出部A までもが、温度上昇を続けることになって、発熱と放熱とが平衡となる平衡温度になるまでの時間が長くなるので、赤外線吸収に基づく発熱による温度変化の検出に時間がかかることになり、赤外線を迅速に検出することができなくなってしまう。
【０００８】
本発明は、上記の点に着目してなされたもので、その目的とするところは、赤外線を迅速に検出することができる赤外線検出素子を提供することにある。
【０００９】
【課題を解決するための手段】
上記した課題を解決するために、請求項１記載の発明は、雰囲気ガス中に封入される赤外線検出素子であって、検出される赤外線を吸収して温度変化する赤外線検出部と、赤外線検出部を支持する支持部材と、雰囲気ガスの平均自由行程よりも小さい空隙を間に有して赤外線検出部と対向する対向面が設けられた対向部材と、を備え、前記対向部材は、前記対向面とは反対側の反対面が略最外面となるよう前記支持部材から直接延設された構成としている。
【００１０】
請求項２記載の発明は、請求項１記載の発明において、前記対向部材又は前記赤外線検出部の少なくとも一方は、他方に向かって突設部が突設された構成としている。
【００１１】
請求項３記載の発明は、請求項１記載の発明において、前記対向部材は、前記雰囲気ガスの平均自由行程よりも小さく前記空隙と平行な間隙を間に有して互いに対向する複数の対向部が設けられた構成としている。
【００１２】
請求項４記載の発明は、請求項３記載の発明において、前記対向部は、互いの対向方向へ向かって突起が突設された構成としている。
【００１３】
請求項５記載の発明は、請求項１乃至請求項４のいずれかに記載の発明において、前記対向部材は、前記反対面に赤外線波長選択フィルターが設けられた構成としている。
【００１４】
請求項６記載の発明は、請求項１乃至請求項５のいずれかに記載の発明において、前記雰囲気ガスは、ヘリウム又は水素である構成としている。
【００１５】
請求項７記載の発明は、請求項１乃至請求項６のいずれかに記載の発明において、前記雰囲気ガスの圧力は、１０ｈＰａ以下である構成としている。
【００１６】
請求項８記載の発明は、雰囲気ガス中に封入される赤外線検出素子であって、検出される赤外線を吸収してそれぞれ温度変化する複数の赤外線検出部と、複数の赤外線検出部を１つずつ支持する複数の支持部材と、雰囲気ガスの平均自由行程よりも小さい空隙を間に有して複数の赤外線検出部と対向する対向面が設けられた対向部材と、を備え、前記対向部材は、前記対向面とは反対側の反対面が略最外面となるよう複数の前記支持部材からそれぞれ直接延設された構成としている。
【００１７】
請求項９記載の発明は、雰囲気ガス中に封入される赤外線検出素子であって、検出される赤外線を吸収してそれぞれ温度変化する複数の赤外線検出部と、複数の赤外線検出部を支持する支持部材と、雰囲気ガスの平均自由行程よりも小さい空隙を間に有して赤外線検出部と対向する対向面が設けられた対向部材と、を備え、前記対向部材は、前記雰囲気ガスの平均自由行程よりも小さく空隙に平行な間隙を間に有して互いに対向する複数の対向部が設けられた単一部材であるとともに、前記対向面とは反対側の反対面が略最外面となるよう複数の前記支持部材から直接延設された構成としている。
【００１８】
請求項１０記載の発明は、請求項１乃至請求項７のいずれかに記載の赤外線検出素子からなる検出部と、検出部とされた請求項１乃至請求項７のいずれかに記載の赤外線検出素子の前記対向部材の前記反対面に赤外線遮蔽層が設けられてなる温度補償部と、を備えた構成としている。
【００１９】
【発明の実施の形態】
本発明の第１実施形態を図１乃至図３に基づいて以下に説明する。なお、図１は、図２のＰ−Ｑ断面図である。
【００２０】
1 はシリコン製の基板で、その表面には窒化シリコンからなる絶縁膜2 が形成されている。3 は赤外線検出部で、薄膜抵抗体（赤外線検出体）4 、電極5 、支持層6 及び赤外線検出層7 からなり、赤外線検出層7 によって赤外線を吸収して温度変化する。薄膜抵抗体4 は、アモルファスシリコン製のサーミスタであって、その抵抗値が温度変化と共に変化する。電極5 は、クロム製であって、薄膜抵抗体4 を挟持するようパターン形成されている。この電極5 は、薄膜抵抗体4 の抵抗値を検出して、外部回路（図示ぜず）に出力する。赤外線検出層7 は、酸化シリコン製であって、赤外線が入射される面に形成されている。
【００２１】
8 は支持部材で、その本体部分から複数の梁9 を延設し、その梁9 の先端部でもって赤外線検出部3 を支持している。前述した電極5 は、この梁9 により引き出されて、電極端子10に接続されている。
【００２２】
11は第１の対向部材で、例えば、約１μｍの空隙12を間に有して赤外線検出部3 と対向する対向面13が設けられ、その対向面13とは反対側の反対面14が略最外面となるよう、支持部材8 から直接延設されている。この第１の対向部材11は、エッチング孔15が設けられて、そのエッチング孔15を通したウエットエッチングによって、ＰＳＧ犠牲層をエッチング除去することにより、赤外線検出部3 との間の空隙12となる空間が設けられるとともに、その空隙12と平行な約１μｍの間隙16が設けられて、互いに対向する複数の対向部17が形成される。また、この第１の対向部材11は、赤外線検出部3 との間の空隙12となる空間には、赤外線検出部3 に向かって突設部18が突設されるとともに、対向する対向部17との間隙16には、対向方向へ向かって先端が尖状の突起19が突設されている。
【００２３】
20は第２の対向部材で、例えば、約１μｍの空隙21を間に有して赤外線検出部3 と対向する対向面22が設けられ、その対向面22とは反対側の反対面23が略最外面となるよう、支持部材8 から直接延設されている。この第２の対向部材20は、エッチング孔24が設けられて、そのエッチング孔24を通したウエットエッチングによって、ＰＳＧ犠牲層をエッチング除去することにより、赤外線検出部3 との間の空隙21となる空間が設けられるとともに、その空隙21と平行な約１μｍの間隙25が設けられて、互いに対向する複数の対向部26が形成される。また、この第２の対向部材20は、赤外線検出部3 との間の空隙21となる空間には、赤外線検出部3 に向かって突設部27が突設されるとともに、対向する対向部26との間隙25には、対向方向へ向かって先端が尖状の突起28が突設されている。さらに、この第２の対向部材20は、赤外線が入射される入射面である反対面23に赤外線波長選択フィルター29が設けられている。
【００２４】
このように構成された赤外線検出素子は、図３に示すように、パッケージ30の内部に封入された状態で実装され、ステム31に貫通固定されたピン32に、電極端子10がワイヤ33を介して接続されて、外部回路に接続される。このパッケージ30の内部は、１０ｈＰａのヘリウムが気密封止されており、この圧力でのヘリウムの平均自由行程は、１７μｍであるから、約１μｍの空隙12,21 及び間隙16,25 の方が、平均自由行程よりも小さくなっている。また、パッケージ30に設けられた窓部には、ＡＲコートが施されたフィルター34が設けられている。
【００２５】
次に、この赤外線検出素子40を検出部50a とした赤外線検出装置50について説明する。この赤外線検出装置50は、温度補償部50b として、検出部50a となる赤外線検出素子40の第１の対向部材11の反対面14に、図５に示すように、赤外線遮蔽層35が設けられた構成となっており、図４に示すように、矢示する赤外線を検出する検出部50a の薄膜抵抗体4 と温度補償部50b の薄膜抵抗体4aとが直列接続されている。
【００２６】
かかる赤外線検出素子40にあっては、支持部材8 から直接延設されてなる第１及び第２の対向部材11,19 は、その対向面13,22 とは反対側の反対面14,23 が略最外の放熱面となるのであって、従来例のように、第１の基板及び第２の基板といった熱容量を飽和させるまで加熱される部材に向かって放熱するわけではないから、赤外線検出部3 までもが、温度上昇を続けるということがなくなり、発熱と放熱とが平衡となる平衡温度になるまでの時間が短くなるので、赤外線吸収に基づく発熱による温度変化の検出に時間がかからなくなり、赤外線を迅速に検出することができる。
【００２７】
また、突設部18,27 が突設されることによって、第１及び第２の対向部材11,20 は、赤外線検出部3 に接近しても、これらの第１及び第２の対向部材11,20 に突設された突設部18,27 により当接するから、双方が接合してしまうということがなくなり、第１及び第２の対向部材11,12 と赤外線検出部3 との間の雰囲気ガスの平均自由行程よりも小さい空隙12,21 を確保することができる。従って、赤外線検出部3 から熱エネルギーを伝達された雰囲気ガス分子は、他の雰囲気ガス分子に衝突する前に第１及び第２の対向部材11,20 に確実に衝突するから、雰囲気ガス分子同士の衝突に基づく熱エネルギーの伝達が少なくなり、つまり雰囲気ガスへの放熱が少なくなるので、赤外線検出部3 での温度変化が赤外線吸収による発熱に基づくものとなるから、赤外線検出感度を高くすることができるという効果を、確実に奏することができる。
【００２８】
また、赤外線検出部3 から熱エネルギーを伝達された雰囲気ガス分子に衝突されて熱エネルギーが伝達された一対向部17,26 から、再び別の雰囲気ガス分子に熱エネルギーが伝達されても、その熱エネルギーが伝達された雰囲気ガス分子は、他の雰囲気ガス分子に衝突する前に、第１又は第２の対向部材11,20 を構成する別の対向部17,26 に衝突するから、雰囲気ガス分子同士の衝突に基づく熱エネルギーの伝達が少なくなり、つまり雰囲気ガスへの放熱が少なくなるので、赤外線検出感度をより高くすることができる。
【００２９】
また、突起19,28 が突設されることによって、互いに対向する対向部17,26 は、他方に接近しても、互いの対向方向へ向かって突設された突起19,28 が当接するから、双方が接合してしまうということがなくなり、対向部17,26 間の雰囲気ガスの平均自由行程よりも小さい間隙を確保することができる。従って、赤外線検出部から熱エネルギーを伝達された雰囲気ガス分子に衝突されて熱エネルギーが伝達された一対向部17,26 から、再び別の雰囲気ガス分子に熱エネルギーが伝達されても、その熱エネルギーが伝達された雰囲気ガス分子は、他の雰囲気ガス分子に衝突する前に、第１又は第２の対向部材11,20 を構成する別の対向部17,26 に確実に衝突するから、雰囲気ガス分子同士の衝突に基づく熱エネルギーの伝達が少なくなり、つまり雰囲気ガスへの放熱が少なくなるので、赤外線検出感度を高くすることができるという効果を、確実に奏することができる。
【００３０】
また、対向部26の反対面23に赤外線波長選択フィルター29が設けられることによって、種々の赤外線に対して、波長の選択性を有することができる。
【００３１】
また、ヘリウムは、他の気体に比較して、平均自由行程が長いから、空隙12,21 又は間隙16,25 を大きくすることができ、製作がやり易くなる。
【００３２】
また、雰囲気ガスの圧力が１０ｈＰａ以下であることにより、雰囲気ガスの平均自由行程を長くすることができるので、空隙12,21 又は間隙16,25 を大きくすることができ、製作がやり易くなる。
【００３３】
また、この赤外線検出素子40を備えた赤外線検出装置50にあっては、温度補償部50b は、第２の対向部材20の反対面23に赤外線遮蔽層35が設けられていること以外は、検出部50a とは同一構成となっているから、熱コンダクタンスや熱容量が同一となり、環境温度が変化することによる赤外線検出精度が低下しなくなる。
【００３４】
次に、本発明の第２実施形態を図６に基づいて以下に説明する。なお、第１実施形態と実質的に同一の部材には同一の記号を付し、第１実施形態と異なるところのみ記す。第１実施形態では、赤外線検出部3 は、唯１つであるのに対し、本実施形態では、同一平面上に複数個設けられた、いわゆるアレイ型の構成となっている。詳しくは、支持部材8 は複数個設けられており、それらの支持部材8 が、複数の赤外線検出部3 を１つずつ支持している。第１及び第２の対向部材11,20 は、対向面13,22 とは反対側の反対面14,23 が略最外面となるよう複数の支持部材8 からそれぞれ直接延設されている。
【００３５】
かかる赤外線検出素子にあっては、赤外線検出部3 は、同一平面上に複数個設けられた、いわゆるアレイ型の構成となっているが、第１実施形態と同様の効果を奏することができる。
【００３６】
次に、本発明の第３実施形態を図７に基づいて以下に説明する。なお、第２実施形態と実質的に同一の部材には同一の記号を付し、第２実施形態と異なるところのみ記す。第２実施形態では、第１及び第２の対向部材11,20 は、対向面13,22 とは反対側の反対面14,23 が略最外面となるよう複数の支持部材8 からそれぞれ直接延設されているのに対し、本実施形態では、いずれかの支持部材8 から延設された単一部材となっている。
【００３７】
かかる赤外線検出素子40にあっては、第２実施形態の効果に加えて、第１及び第２の対向部材11,20 は、複数の赤外線検出部3 に１つずつ対向する複数の部材ではなく、単一部材であるから、互いに対向する対向部17,26 間の間隙16,25 を揃えやすくなり、ひいては、赤外線検出部3 の断熱性が等しくなるので、赤外線検出素子40の感度分布が減少する。
【００３８】
なお、第１乃至第３実施形態では、第１及び第２の対向部材11,20 は、突設部18,27 が突設されているが、第１及び第２の対向部材11,20 が赤外線検出部3 に接合する恐れがないときは、突設部18,27 が突設されなくてもよく、そのときは製作がより容易になる。
【００３９】
また、第１乃至第３実施形態では、突設部18,27 は、第１及び第２の対向部材11,20 に突設されているが、赤外線検出部3 に突設部が突設されても、第１及び第２の対向部材11,20 並びに赤外線検出部3 の双方に突設部が突設されても、同様の効果を奏することができる。
【００４０】
また、第１乃至第３実施形態では、第１及び第２の対向部材11,20 は、雰囲気ガスの平均自由行程よりも小さく空隙12,21 と平行な間隙16,25 を間に有して互いに対向する複数の対向部17,26 からなるが、例えば、赤外線検出感度を十分高いときは、このような構成にしなくてもよい。
【００４１】
また、第１乃至第３実施形態では、対向部17,26 は、互いの対向方向へ向かって突起19,28 が突設されているが、対向部17,26 が接合する恐れがないときは、突起19,28 が突設されなくてもよく、そのときは製作がより容易になる。
【００４２】
また、第１乃至第３実施形態では、第２の対向部材20は、反対面23に赤外線波長選択フィルター29が設けられているが、例えば、パッケージ30に設けられた窓部に赤外線波長選択フィルター29が設けられているときは、設けられなくてもよい。
【００４３】
また、第１乃至第３実施形態では、雰囲気ガスは、ヘリウムであるが、ヘリウムに限るものではなく、その圧力を１０ｈＰａ以下に限るものでもない。
【００４４】
また、第１乃至第３実施形態では、薄膜抵抗体4 は、アモルファスシリコン製であるが、アモルファスシリコン製に限るものではなく、抵抗温度係数が比較的大きなポリシリコン製の材料でもよく、さらに、サーミスタ以外の薄膜熱伝対や薄膜焦電体でもよい。
【００４５】
また、第１乃至第３実施形態では、第１及び第２の対向部材11,20 が設けられているが、いずれか一方の対向部材のみ設けられてもよい。
【００４６】
【発明の効果】
請求項１記載の発明は、支持部材から直接延設されてなる対向部材は、その対向面とは反対面が略最外の放熱面となるのであって、従来例のように、第１の基板及び第２の基板といった熱容量が飽和させるまで加熱される部材に向かって放熱するわけではないから、赤外線検出部までもが、温度上昇を続けるということがなくなり、発熱と放熱とが平衡となる平衡温度になるまでの時間が短くなるので、赤外線吸収に基づく発熱による温度変化の検出に時間がかからなくなり、赤外線を迅速に検出することができる。
【００４７】
請求項２記載の発明は、突設部が突設されることによって、対向部材又は赤外線検出部は、他方に接近しても、少なくとも一方に突設された突設部により当接するから、双方が接合してしまうということがなくなり、対向部材と赤外線検出部との間の雰囲気ガスの平均自由行程よりも小さい空隙を確保することができる。従って、赤外線検出部から熱エネルギーを伝達された雰囲気ガス分子は、他の雰囲気ガス分子に衝突する前に対向部材に確実に衝突するから、雰囲気ガス分子同士の衝突に基づく熱エネルギーの伝達が少なくなり、つまり雰囲気ガスへの放熱が少なくなるので、赤外線検出部での温度変化が赤外線吸収による発熱に基づくものとなるから、赤外線検出感度を高くすることができるという効果を、確実に奏することができる。
【００４８】
請求項３記載の発明は、請求項１記載の発明の効果に加えて、赤外線検出部から熱エネルギーを伝達された雰囲気ガス分子に衝突されて熱エネルギーが伝達された一対向部から、再び別の雰囲気ガス分子に熱エネルギーが伝達されても、その熱エネルギーが伝達された雰囲気ガス分子は、他の雰囲気ガス分子に衝突する前に、対向部材を構成する別の対向部に衝突するから、雰囲気ガス分子同士の衝突に基づく熱エネルギーの伝達が少なくなり、つまり雰囲気ガスへの放熱が少なくなるので、赤外線検出感度をより高くすることができる。
【００４９】
請求項４記載の発明は、突起が突設されることによって、互いの対向する対向部は、他方に接近しても、互いの対向方向へ向かって突設された突起が当接するから、双方が接合してしまうということがなくなり、対向部間の雰囲気ガスの平均自由行程よりも小さい間隙を確保することができる。従って、赤外線検出部から熱エネルギーを伝達された雰囲気ガス分子に衝突されて熱エネルギーが伝達された一対向部から、再び別の雰囲気ガス分子に熱エネルギーが伝達されても、その熱エネルギーが伝達された雰囲気ガス分子は、他の雰囲気ガス分子に衝突する前に、対向部材を構成する別の対向片に確実に衝突するから、雰囲気ガス分子同士の衝突に基づく熱エネルギーの伝達が少なくなり、つまり雰囲気ガスへの放熱が少なくなるので、赤外線検出感度を高くすることができるという効果を、確実に奏することができる。
【００５０】
請求項５記載の発明は、請求項１乃至請求項４のいずれかに記載の発明にいて、対向部の反対面に赤外線波長選択フィルターが設けられることによって、種々の赤外線に対して、波長の選択性を有することができる。
【００５１】
請求項６記載の発明は、ヘリウム又は水素は、他の気体に比較して、平均自由行程が長いから、空隙又は間隙を大きくすることができ、請求項１乃至請求項５のいずれかに記載の発明よりも、製作がやり易くなる。
【００５２】
請求項７記載の発明は、雰囲気ガスの圧力が１０ｈＰａ以下であることにより、雰囲気ガスの平均自由行程を長くすることができるので、空隙又は間隙を大きくすることができ、請求項１乃至請求項６のいずれかに記載の発明よりも、製作がやり易くなる。
【００５３】
請求項８記載の発明は、支持部材からそれぞれ直接延設されてなる対向部材は、その対向面とは反対面が略最外の放熱面となるのであって、従来例のように、第１の基板及び第２の基板といった熱容量が飽和させるまで加熱される部材に向かって放熱するわけではないから、いずれの赤外線検出部も温度上昇を続けるということがなくなり、発熱と放熱とが平衡となる平衡温度になるまでの時間が短くなるので、赤外線吸収に基づく発熱による温度変化の検出に時間がかからなくなり、赤外線を迅速に検出することができる。
【００５４】
請求項９記載の発明は、支持部材からそれぞれ直接延設されてなる対向部材は、その対向面とは反対面が略最外の放熱面となるのであって、従来例のように、第１の基板及び第２の基板といった熱容量が飽和させるまで加熱される部材に向かって放熱するわけではないから、いずれの赤外線検出部も温度上昇を続けるということがなくなり、発熱と放熱とが平衡となる平衡温度になるまでの時間が短くなるので、赤外線吸収に基づく発熱による温度変化の検出に時間がかからなくなり、赤外線を迅速に検出することができる。また、赤外線検出部から熱エネルギーを伝達された雰囲気ガス分子に衝突されて熱エネルギーが伝達された一対向部から、再び別の雰囲気ガス分子に熱エネルギーが伝達されても、その熱エネルギーが伝達された雰囲気ガス分子は、他の雰囲気ガス分子に衝突する前に、対向部材を構成する別の対向部に衝突するから、雰囲気ガス分子同士の衝突に基づく熱エネルギーの伝達が少なくなり、つまり雰囲気ガスへの放熱が少なくなるので、赤外線検出感度をより高くすることができる。さらに、対向部材は、複数の赤外線検出部に１つずつ対向する複数の部材ではなく、単一部材であるから、互いに対向する対向部間の間隙を揃えやすくなり、ひいては、赤外線検出部の断熱性が等しくなるので、赤外線検出素子の感度分布が減少する。
【００５５】
請求項１０記載の発明は、請求項１乃至請求項７のいずれかに記載の発明の効果に加えて、温度補償部は、対向部材の反対面に赤外線遮蔽層が設けられていること以外は、検出部とは同一構成となっているから、熱コンダクタンスや熱容量が同一となり、環境温度が変化することによる赤外線検出精度が低下しなくなる。
【図面の簡単な説明】
【図１】本発明の第１実施形態の断面図である。
【図２】同上の平面図である。
【図３】同上のものをパッケージ内で支持して収容した状態を示す断面図である。
【図４】同上のものを備えた赤外線検出装置の回路図である。
【図５】同上のものを備えた赤外線検出装置の補償部の断面図である。
【図６】本発明の第２実施形態の概略断面図である。
【図７】本発明の第３実施形態の概略断面図である。
【図８】従来例の断面図である。
【符号の説明】
3 赤外線検出部
8 支持部材
11 第１の対向部材
12 空隙
13 対向面
14 反対面
16 間隙
17 対向部
18 突設部
19 突起
20 第２の対向部材
21 空隙
22 対向面
23 反対面
25 間隙
27 突設部
40 赤外線検出素子
26 対向部
28 突起
29 赤外線波長選択フィルター
35 赤外線遮蔽層
50 赤外線検出装置
50a 検出部
50b 温度補償部[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an infrared detection element that detects infrared rays by a temperature change based on infrared absorption.
[0002]
[Prior art]
Conventionally, as this kind of infrared detection element X, there is one disclosed in JP-A-10-9949. This is an infrared detecting element enclosed in an atmospheric gas. As shown in FIG. 8, the infrared detecting portion A, the supporting member B, the first opposing member C, the insulating film D, and the first substrate E. , A second opposing member F 2, and a second substrate G 2.
[0003]
The infrared detector A absorbs the detected infrared and changes its temperature. The support member B extends a plurality of beams B ₁ and supports the infrared detection unit A with the tip of the beam B ₁ . First opposing member C is extended from the support member B, facing surfaces C ₂ facing the infrared detecting part A has between a small gap C ₁ than the mean free path of the atmospheric gas is provided ing. Specifically, the first opposing member C has a plurality of facing portions C ₄ facing each other have between the average smaller than the free path the gap C ₁ between the parallel gap C ₃ of the atmospheric gas is provided . The first facing member C is bonded to the first substrate E via the insulating film D 1, so that the opposite surface C ₅ opposite to the facing surface C ₂ has the first surface facing the first film E via the insulating film D 1. Opposite to substrate E.
[0004]
Second opposing member F, the supporting member B and extending from the second substrate G which is continuously provided from the mean free path infrared detector A has between a small gap F ₁ than the atmospheric gas opposing surface F ₂ which faces are provided with. Specifically, like the first facing member C, the second facing member F 2 is a plurality of facing each other with a gap F ₃ smaller than the mean free path of the atmospheric gas and parallel to the gap F _1. The opposite portion F ₄ is provided. In the second facing member F, the opposite surface F ₅ opposite to the facing surface F ₂ is opposed to the second substrate G 2.
[0005]
[Problems to be solved by the invention]
In the above-described conventional infrared detection element, since the gaps C and F between the infrared detection unit A and the opposing members C and F are smaller than the mean free path of the atmospheric gas, the infrared detection unit A Since the atmospheric gas molecules transferred from the thermal energy collide with the opposing members C and F before colliding with other atmospheric gas molecules, the transmission of thermal energy based on the collision between the atmospheric gas molecules is reduced. Since the heat radiation to the atmospheric gas is reduced, the temperature change in the infrared detection part A is based on the heat generated by the infrared absorption, so that the infrared detection sensitivity can be further increased.
[0006]
However, this is because the opposite surface C _{5 of} the first opposing member C is opposed to the first substrate E via the insulating film D, so that the first opposing member C 1 is opposed to the first surface C ₅ . The heat is dissipated toward the first substrate E, and the first substrate E is heated until its own heat capacity is saturated. If this happens, the temperature of the infrared detector A will continue to rise, and the time until the temperature reaches the equilibrium temperature where heat generation and heat dissipation are balanced will be longer. It will take time, and it will not be possible to detect infrared rays quickly.
[0007]
Further, this is because the opposite surface F ₅ opposite to the facing surface F _{2 of} the second facing member F 1 faces the second substrate G 2, so that the opposite surface F of the second facing member F 2 _The heat is dissipated from ₅ toward the second substrate G, and the second substrate G is heated until its own heat capacity is saturated. If this happens, the temperature of the infrared detector A will continue to rise, and the time until the temperature reaches the equilibrium temperature where heat generation and heat dissipation are balanced will be longer. It will take time, and infrared rays cannot be detected quickly.
[0008]
The present invention has been made paying attention to the above points, and an object of the present invention is to provide an infrared detection element capable of rapidly detecting infrared rays.
[0009]
[Means for Solving the Problems]
In order to solve the above-described problems, an invention according to claim 1 is an infrared detection element enclosed in an atmospheric gas, and an infrared detection unit that absorbs detected infrared rays and changes temperature, and an infrared detection unit And a facing member provided with a facing surface facing the infrared detection unit with a gap smaller than the mean free path of the atmospheric gas in between, and the facing member is the facing surface It is set as the structure directly extended from the said supporting member so that the opposite surface on the opposite side may become a substantially outermost surface.
[0010]
According to a second aspect of the present invention, in the first aspect of the present invention, at least one of the opposing member and the infrared detection unit is configured such that a protruding portion protrudes toward the other.
[0011]
According to a third aspect of the present invention, in the first aspect of the invention, the opposing member has a plurality of opposing portions that are opposed to each other with a gap that is smaller than the mean free path of the atmospheric gas and that is parallel to the gap. It is set as the structure provided.
[0012]
According to a fourth aspect of the present invention, in the third aspect of the present invention, the facing portion is configured such that a protrusion protrudes in the facing direction.
[0013]
According to a fifth aspect of the present invention, in the invention according to any one of the first to fourth aspects of the present invention, the opposing member has a configuration in which an infrared wavelength selection filter is provided on the opposite surface.
[0014]
A sixth aspect of the present invention is the invention according to any one of the first to fifth aspects, wherein the atmospheric gas is helium or hydrogen.
[0015]
The invention according to claim 7 is the invention according to any one of claims 1 to 6, wherein the pressure of the atmospheric gas is 10 hPa or less.
[0016]
The invention according to claim 8 is an infrared detection element enclosed in an atmospheric gas, and includes a plurality of infrared detection units each absorbing a detected infrared ray and changing in temperature, and a plurality of infrared detection units one by one. A plurality of supporting members to be supported, and a facing member provided with a facing surface facing the plurality of infrared detection units with a gap smaller than the mean free path of the atmospheric gas interposed therebetween, Each of the plurality of support members is directly extended so that the opposite surface opposite to the facing surface is substantially the outermost surface.
[0017]
The invention according to claim 9 is an infrared detecting element enclosed in an atmospheric gas, wherein the infrared detecting element absorbs the detected infrared and changes in temperature, and a support for supporting the plurality of infrared detecting sections. And a facing member provided with a facing surface facing the infrared detection part with a gap smaller than the mean free path of the ambient gas, the facing member having a mean free path of the ambient gas And a single member provided with a plurality of facing portions facing each other with a gap parallel to the gap in between, and a plurality of opposite surfaces opposite to the facing surface are substantially outermost surfaces. It is set as the structure extended directly from the said supporting member.
[0018]
A tenth aspect of the present invention is a detection unit comprising the infrared detection element according to any one of the first to seventh aspects, and the infrared detection according to any one of the first to seventh aspects, wherein the detection unit is a detection unit. And a temperature compensation unit in which an infrared shielding layer is provided on the opposite surface of the opposing member of the element.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
A first embodiment of the present invention will be described below with reference to FIGS. 1 is a PQ cross-sectional view of FIG.
[0020]
Reference numeral 1 denotes a silicon substrate on which an insulating film 2 made of silicon nitride is formed. Reference numeral 3 denotes an infrared detection unit, which includes a thin film resistor (infrared detector) 4, an electrode 5, a support layer 6, and an infrared detection layer 7. The infrared detection layer 7 absorbs infrared rays and changes its temperature. The thin film resistor 4 is a thermistor made of amorphous silicon, and its resistance value changes with temperature change. The electrode 5 is made of chromium and is patterned so as to sandwich the thin film resistor 4. The electrode 5 detects the resistance value of the thin film resistor 4 and outputs it to an external circuit (not shown). The infrared detection layer 7 is made of silicon oxide and is formed on a surface on which infrared rays are incident.
[0021]
Reference numeral 8 denotes a support member. A plurality of beams 9 are extended from the main body portion, and the infrared detection unit 3 is supported by the tip of the beam 9. The electrode 5 described above is drawn out by the beam 9 and connected to the electrode terminal 10.
[0022]
Reference numeral 11 denotes a first facing member. For example, a facing surface 13 facing the infrared detection unit 3 with a gap 12 of about 1 μm is provided, and the facing surface 14 opposite to the facing surface 13 is substantially the same. It extends directly from the support member 8 so as to be the outermost surface. The first opposing member 11 is provided with an etching hole 15, and the PSG sacrificial layer is removed by wet etching through the etching hole 15, thereby forming a gap 12 between the first opposing member 11 and the infrared detection unit 3. A space is provided, and a gap 16 of about 1 μm parallel to the gap 12 is provided to form a plurality of facing portions 17 facing each other. The first facing member 11 has a projecting portion 18 projecting toward the infrared detecting portion 3 and a facing facing portion 17 facing the infrared detecting portion 3 in a space serving as a gap 12 between the first facing member 11 and the infrared detecting portion 3. A protrusion 19 having a pointed tip is provided in the gap 16 with respect to the opposite direction.
[0023]
Reference numeral 20 denotes a second facing member. For example, a facing surface 22 facing the infrared detecting section 3 is provided with a gap 21 of about 1 μm in between, and the facing surface 23 opposite to the facing surface 22 is substantially the same. It extends directly from the support member 8 so as to be the outermost surface. The second facing member 20 is provided with an etching hole 24, and the PSG sacrificial layer is etched away by wet etching through the etching hole 24, thereby forming a gap 21 with the infrared detecting unit 3. A space is provided, and a gap 25 of about 1 μm parallel to the gap 21 is provided to form a plurality of facing portions 26 that face each other. The second facing member 20 has a projecting portion 27 projecting toward the infrared detecting portion 3 and a facing facing portion 26 facing the infrared detecting portion 3 in a space that becomes a gap 21 between the second facing member 20 and the infrared detecting portion 3. In the gap 25, a protrusion 28 having a pointed tip is provided in the opposite direction. Further, the second facing member 20 is provided with an infrared wavelength selection filter 29 on the opposite surface 23 which is an incident surface on which infrared rays are incident.
[0024]
As shown in FIG. 3, the infrared detection element configured as described above is mounted in a state of being enclosed in a package 30, and the electrode terminal 10 is connected via a wire 33 to a pin 32 that is penetrated and fixed to the stem 31. Connected to an external circuit. The inside of the package 30 is hermetically sealed with 10 hPa helium, and the mean free path of helium at this pressure is 17 μm. Therefore, the air gaps 12 and 21 and the gaps 16 and 25 of about 1 μm are It is smaller than the mean free path. Further, a filter 34 to which an AR coating is applied is provided at a window provided in the package 30.
[0025]
Next, an infrared detection apparatus 50 using the infrared detection element 40 as a detection unit 50a will be described. As shown in FIG. 5, the infrared detecting device 50 is provided with an infrared shielding layer 35 on the opposite surface 14 of the first opposing member 11 of the infrared detecting element 40 serving as the detecting unit 50a as the temperature compensating unit 50b. As shown in FIG. 4, the thin film resistor 4 of the detection unit 50a for detecting the infrared ray indicated by the arrow and the thin film resistor 4a of the temperature compensation unit 50b are connected in series.
[0026]
In the infrared detecting element 40, the first and second opposing members 11, 19 extending directly from the support member 8 have opposing surfaces 14, 23 opposite to the opposing surfaces 13, 22. Since it is a substantially outermost heat radiating surface, it does not radiate heat toward the member that is heated until the heat capacity is saturated, such as the first substrate and the second substrate, as in the conventional example. However, it will not take a long time to detect temperature changes due to heat generation based on infrared absorption because the temperature will not continue to rise until the temperature reaches the equilibrium temperature where heat generation and heat dissipation are balanced. Infrared rays can be detected quickly.
[0027]
Further, since the projecting portions 18 and 27 are projected, even if the first and second opposing members 11 and 20 are close to the infrared detecting unit 3, these first and second opposing members 11 are used. , 20 abuts by the projecting portions 18, 27 projecting from each other, so that they are not joined together, and the atmosphere between the first and second opposing members 11, 12 and the infrared detecting unit 3 is eliminated. It is possible to secure voids 12 and 21 smaller than the mean free path of the gas. Accordingly, the atmospheric gas molecules transmitted with the thermal energy from the infrared detector 3 reliably collide with the first and second opposing members 11 and 20 before colliding with other atmospheric gas molecules. Since the transmission of thermal energy due to the collision of the heat is reduced, that is, the heat radiation to the atmosphere gas is reduced, the temperature change in the infrared detector 3 is based on the heat generated by infrared absorption, so the infrared detection sensitivity should be increased. The effect that it is possible can be produced reliably.
[0028]
In addition, even if thermal energy is transmitted to another atmospheric gas molecule again from one opposed portion 17, 26 that has been collided with atmospheric gas molecules to which thermal energy has been transmitted from the infrared detection unit 3 and has been transmitted thermal energy, The atmospheric gas molecules to which the thermal energy has been transmitted collide with the other opposing portions 17 and 26 constituting the first or second opposing member 11 and 20 before colliding with other atmospheric gas molecules. Since the transmission of heat energy based on the collision between molecules is reduced, that is, the heat radiation to the atmospheric gas is reduced, the infrared detection sensitivity can be further increased.
[0029]
In addition, since the protrusions 19 and 28 protrude, the opposing portions 17 and 26 facing each other contact the protrusions 19 and 28 protruding toward each other even when approaching the other. Thus, both are not joined, and a gap smaller than the mean free path of the atmospheric gas between the facing portions 17 and 26 can be secured. Therefore, even if the thermal energy is transmitted to another atmospheric gas molecule again from the one opposed portion 17, 26 where the thermal energy is collided with the atmospheric gas molecule to which the thermal energy is transmitted from the infrared detector, Since the atmospheric gas molecules to which energy has been transmitted collide with the other opposing portions 17, 26 constituting the first or second opposing member 11, 20 before colliding with other atmospheric gas molecules, the atmosphere Since the transmission of thermal energy based on the collision between gas molecules is reduced, that is, the heat radiation to the atmospheric gas is reduced, the effect that the infrared detection sensitivity can be increased can be reliably achieved.
[0030]
Further, by providing the infrared wavelength selection filter 29 on the opposite surface 23 of the facing portion 26, it is possible to have wavelength selectivity with respect to various infrared rays.
[0031]
In addition, helium has a longer mean free path than other gases, so that the gaps 12 and 21 or the gaps 16 and 25 can be enlarged, and manufacturing is facilitated.
[0032]
Further, when the pressure of the atmospheric gas is 10 hPa or less, the average free path of the atmospheric gas can be increased, so that the gaps 12 and 21 or the gaps 16 and 25 can be enlarged, and the manufacturing becomes easy.
[0033]
In addition, in the infrared detecting device 50 provided with the infrared detecting element 40, the temperature compensating unit 50b is detected except that the infrared shielding layer 35 is provided on the opposite surface 23 of the second opposing member 20. Since the unit 50a has the same configuration, the thermal conductance and the heat capacity are the same, and the infrared detection accuracy due to the change in the environmental temperature does not decrease.
[0034]
Next, a second embodiment of the present invention will be described below based on FIG. In addition, the substantially same member as 1st Embodiment is attached | subjected with the same code | symbol, and only the difference from 1st Embodiment is described. In the first embodiment, there is only one infrared detecting unit 3, whereas in the present embodiment, a plurality of infrared detectors 3 are provided on the same plane. Specifically, a plurality of support members 8 are provided, and these support members 8 support a plurality of infrared detection units 3 one by one. The first and second opposing members 11 and 20 are directly extended from the plurality of support members 8 so that the opposing surfaces 14 and 23 opposite to the opposing surfaces 13 and 22 are substantially outermost surfaces.
[0035]
In such an infrared detection element, the infrared detection unit 3 has a so-called array type configuration in which a plurality of infrared detection units 3 are provided on the same plane, but the same effects as those of the first embodiment can be obtained.
[0036]
Next, a third embodiment of the present invention will be described below based on FIG. Note that members that are substantially the same as those in the second embodiment are denoted by the same reference numerals, and only differences from the second embodiment are described. In the second embodiment, the first and second opposing members 11 and 20 extend directly from the plurality of support members 8 so that the opposite surfaces 14 and 23 opposite to the opposing surfaces 13 and 22 are substantially outermost surfaces. In contrast, in the present embodiment, a single member extending from any one of the support members 8 is provided.
[0037]
In such an infrared detecting element 40, in addition to the effects of the second embodiment, the first and second opposing members 11, 20 are not a plurality of members that face the plurality of infrared detecting sections 3 one by one. Since it is a single member, it becomes easy to align the gaps 16 and 25 between the opposed portions 17 and 26 facing each other, and as a result, the thermal insulation of the infrared detection unit 3 becomes equal, so the sensitivity distribution of the infrared detection element 40 is reduced. To do.
[0038]
In the first to third embodiments, the first and second opposing members 11 and 20 are provided with protruding portions 18 and 27, but the first and second opposing members 11 and 20 are provided. When there is no fear of joining to the infrared detection unit 3, the projecting portions 18 and 27 do not have to be projecting, and in that case, manufacture becomes easier.
[0039]
In the first to third embodiments, the projecting portions 18 and 27 project from the first and second opposing members 11 and 20, but the projecting portions project from the infrared detection unit 3. However, the same effect can be obtained even if projecting portions are provided on both the first and second opposing members 11 and 20 and the infrared detecting portion 3.
[0040]
In the first to third embodiments, the first and second opposing members 11 and 20 have gaps 16 and 25 that are smaller than the mean free path of the atmospheric gas and parallel to the gaps 12 and 21, respectively. Although it is composed of a plurality of facing portions 17, 26 facing each other, for example, when the infrared detection sensitivity is sufficiently high, such a configuration is not necessary.
[0041]
In the first to third embodiments, the opposing portions 17 and 26 are provided with the protrusions 19 and 28 in the opposing direction, but when the opposing portions 17 and 26 are not likely to be joined, The protrusions 19 and 28 do not have to be provided, and the manufacture becomes easier.
[0042]
In the first to third embodiments, the second opposing member 20 is provided with the infrared wavelength selection filter 29 on the opposite surface 23. For example, the infrared wavelength selection filter is provided in a window provided in the package 30. When 29 is provided, it may not be provided.
[0043]
Moreover, in 1st thru | or 3rd embodiment, although atmospheric gas is helium, it is not restricted to helium, The pressure is not restricted to 10 hPa or less.
[0044]
In the first to third embodiments, the thin film resistor 4 is made of amorphous silicon, but is not limited to amorphous silicon, and may be a material made of polysilicon having a relatively large resistance temperature coefficient. A thin film thermocouple other than the thermistor or a thin film pyroelectric material may be used.
[0045]
In the first to third embodiments, the first and second opposing members 11 and 20 are provided, but only one of the opposing members may be provided.
[0046]
【The invention's effect】
According to the first aspect of the present invention, the opposing member extending directly from the supporting member has a surface opposite to the opposing surface which is a substantially outermost heat radiating surface. Since the heat is not released toward the member to be heated until the heat capacity is saturated, such as the substrate and the second substrate, the temperature does not continue to rise up to the infrared detection unit, and the heat generation and the heat dissipation are balanced. Since the time to reach the equilibrium temperature is shortened, it takes less time to detect a temperature change due to heat generation based on infrared absorption, and infrared can be detected quickly.
[0047]
According to the second aspect of the present invention, since the projecting portion is projected, the opposing member or the infrared detecting portion comes into contact with the projecting portion projected at least on one side even when approaching the other. Can be secured, and a gap smaller than the mean free path of the atmospheric gas between the opposing member and the infrared detecting portion can be secured. Accordingly, the atmospheric gas molecules to which the thermal energy is transmitted from the infrared detection unit surely collide with the opposing member before colliding with other atmospheric gas molecules, so that the transmission of thermal energy based on the collision between the atmospheric gas molecules is small. In other words, since the heat radiation to the atmospheric gas is reduced, the temperature change in the infrared detection unit is based on the heat generated by the infrared absorption, so that the effect that the infrared detection sensitivity can be increased can be surely achieved. it can.
[0048]
In addition to the effect of the invention described in claim 1, the invention described in claim 3 is again separated from the one opposed portion to which the thermal energy is transmitted by being collided with the atmospheric gas molecules to which the thermal energy is transmitted from the infrared detector. Even if the thermal energy is transmitted to the atmospheric gas molecules, the atmospheric gas molecules to which the thermal energy has been transmitted collide with another opposing portion constituting the opposing member before colliding with other atmospheric gas molecules. Since the transmission of thermal energy based on the collision between the atmospheric gas molecules is reduced, that is, the heat radiation to the atmospheric gas is reduced, the infrared detection sensitivity can be further increased.
[0049]
In the invention described in claim 4, since the protrusions are provided so that the opposing portions facing each other come into contact with the protrusions protruding toward each other even when approaching the other. And the gap smaller than the mean free path of the atmospheric gas between the opposing portions can be secured. Therefore, even if thermal energy is transmitted again from one opposing part where thermal energy is transmitted by colliding with atmospheric gas molecules to which thermal energy is transmitted from the infrared detector, the thermal energy is transmitted again. Since the atmospheric gas molecules that have been collided with another opposing piece constituting the opposing member before colliding with other atmospheric gas molecules, the transmission of thermal energy based on the collision between the atmospheric gas molecules is reduced, That is, since the heat radiation to the atmospheric gas is reduced, the effect that the infrared detection sensitivity can be increased can be reliably achieved.
[0050]
The invention according to claim 5 is the invention according to any one of claims 1 to 4, wherein an infrared wavelength selection filter is provided on the opposite surface of the facing portion, so that the wavelength of various infrared rays can be reduced. It can have selectivity.
[0051]
According to the sixth aspect of the present invention, since helium or hydrogen has a longer mean free path than other gases, the gap or gap can be increased, and any one of the first to fifth aspects can be achieved. This makes it easier to manufacture.
[0052]
According to the seventh aspect of the present invention, since the mean free path of the atmospheric gas can be increased when the pressure of the atmospheric gas is 10 hPa or less, the gap or gap can be increased. Manufacturing is easier than in the invention according to any one of the sixth aspect.
[0053]
According to the eighth aspect of the present invention, the opposing members extending directly from the support member have the outermost heat radiating surface opposite to the opposing surface, as in the conventional example. Since the heat does not radiate toward the member to be heated until the heat capacity is saturated, such as the first substrate and the second substrate, none of the infrared detection parts continues to rise in temperature, and the heat generation and the heat radiation are balanced. Since the time to reach the equilibrium temperature is shortened, it takes less time to detect a temperature change due to heat generation based on infrared absorption, and infrared can be detected quickly.
[0054]
According to the ninth aspect of the present invention, the opposing members respectively extending directly from the support member have a surface opposite to the opposing surface which is a substantially outermost heat radiating surface. Since the heat does not radiate toward the member to be heated until the heat capacity is saturated, such as the first substrate and the second substrate, none of the infrared detection parts continues to rise in temperature, and the heat generation and the heat radiation are balanced. Since the time to reach the equilibrium temperature is shortened, it takes less time to detect a temperature change due to heat generation based on infrared absorption, and infrared can be detected quickly. In addition, even if thermal energy is transmitted to another atmospheric gas molecule again from one opposing part where thermal energy is collided with the atmospheric gas molecule to which thermal energy is transmitted from the infrared detector, the thermal energy is transmitted again. Since the ambient gas molecules collide with another opposing portion constituting the opposing member before colliding with other atmospheric gas molecules, the transmission of thermal energy based on the collision between the atmospheric gas molecules is reduced, that is, the atmosphere Since heat radiation to the gas is reduced, infrared detection sensitivity can be further increased. Further, since the opposing member is not a plurality of members facing each of the plurality of infrared detection units, but a single member, it becomes easy to align the gaps between the opposing portions facing each other. Since the characteristics are equal, the sensitivity distribution of the infrared detecting element is reduced.
[0055]
According to a tenth aspect of the present invention, in addition to the effects of the first aspect of the present invention, the temperature compensation unit is provided with an infrared shielding layer provided on the opposite surface of the opposing member. Since the detection unit has the same configuration, the thermal conductance and the heat capacity are the same, and the infrared detection accuracy due to the change in the environmental temperature does not decrease.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a first embodiment of the present invention.
FIG. 2 is a plan view of the above.
FIG. 3 is a cross-sectional view showing a state in which the above is supported and accommodated in a package.
FIG. 4 is a circuit diagram of an infrared detecting device including the same as above.
FIG. 5 is a cross-sectional view of a compensation unit of an infrared detecting device including the same as above.
FIG. 6 is a schematic sectional view of a second embodiment of the present invention.
FIG. 7 is a schematic cross-sectional view of a third embodiment of the present invention.
FIG. 8 is a cross-sectional view of a conventional example.
[Explanation of symbols]
3 Infrared detector
8 Support member
11 First counter member
12 Air gap
13 Opposite surface
14 Opposite side
16 gap
17 Opposite part
18 Projection
19 Protrusion
20 Second counter member
21 Air gap
22 Opposite surface
23 Opposite side
25 gap
27 Projection
40 Infrared detector
26 Opposite part
28 Protrusions
29 Infrared wavelength selection filter
35 Infrared shielding layer
50 Infrared detector
50a detector
50b Temperature compensation section

Claims

An infrared detection element enclosed in an atmospheric gas, wherein the infrared detection unit absorbs the detected infrared and changes in temperature, a support member that supports the infrared detection unit, and a void smaller than the mean free path of the atmospheric gas And an opposing member provided with an opposing surface facing the infrared detection unit, wherein the opposing member is configured so that the opposite surface opposite to the opposing surface is substantially the outermost surface. An infrared detecting element characterized in that it is directly extended from.

The infrared detection element according to claim 1, wherein at least one of the facing member and the infrared detection unit has a projecting portion projecting toward the other.

2. The infrared detection according to claim 1, wherein the facing member is provided with a plurality of facing portions facing each other with a gap that is smaller than the mean free path of the atmospheric gas and parallel to the gap. element.

The infrared detection element according to claim 3, wherein the facing portion has a protrusion protruding in a facing direction.

The infrared detection element according to claim 1, wherein an infrared wavelength selection filter is provided on the opposite surface of the facing member.

The infrared detection element according to claim 1, wherein the atmospheric gas is helium or hydrogen.

The infrared detection element according to any one of claims 1 to 6, wherein the pressure of the atmospheric gas is 10 hPa or less.

An infrared detection element enclosed in an atmospheric gas, and a plurality of infrared detection units that absorb the detected infrared and change in temperature, and a plurality of support members that support the plurality of infrared detection units one by one; A counter member provided with a counter surface having a space smaller than the mean free path of the atmospheric gas and facing a plurality of infrared detection units, and the counter member is opposite to the counter surface. An infrared detection element, wherein each of the plurality of support members is directly extended so that the opposite surface is substantially the outermost surface.

An infrared detection element enclosed in an atmospheric gas, which absorbs detected infrared rays and changes in temperature, a support member that supports the multiple infrared detection units, and an average freedom of the atmospheric gas An opposing member having an air gap smaller than the stroke and provided with an opposing surface facing the infrared detection unit, the opposing member being a gap smaller than the mean free path of the atmospheric gas and parallel to the air gap And a single member provided with a plurality of opposing portions facing each other and extending directly from the plurality of support members so that the opposite surface opposite to the facing surface is substantially the outermost surface. An infrared detecting element characterized by being made.

The detection part which consists of an infrared detection element in any one of Claims 1 thru | or 7, and the said opposite member of the said opposing member of the infrared detection element in any one of Claims 1 thru | or 7 made into the detection part An infrared detecting device, comprising: a temperature compensation unit having an infrared shielding layer provided on a surface thereof.