JP4246855B2

JP4246855B2 - Reflective optical sensor and manufacturing method thereof

Info

Publication number: JP4246855B2
Application number: JP19241099A
Authority: JP
Inventors: 克彦野口; 恵堀内
Original assignee: Citizen Electronics Co Ltd
Current assignee: Citizen Electronics Co Ltd
Priority date: 1999-07-06
Filing date: 1999-07-06
Publication date: 2009-04-02
Anticipated expiration: 2019-07-06
Also published as: JP2001024213A

Description

【０００１】
【発明の属する技術分野】
本発明は被検出物の表面からの反射光を検出する反射型光センサとその製造方法に関する。
【０００２】
【従来の技術】
反射型光センサは非接触で物体の有無を検出するセンサであり、モータ等の回転体の制御や、紙、フィルム等の位置、端部の検出などに使用される。図９は反射型光センサの原理的な構成を示し、パッケージ１に、発光素子２（例えば赤外ＬＥＤ）と受光素子３（例えばフォト・トランジスタ）を収容してあり、発光素子２から光が矢印のように出て検出対象の物体４で反射するのを、受光素子３で検知する。これによって、反射型光センサの近傍における物体４の有無や位置に応じて受光素子３からの出力が変化し、これを検出信号として用いるのである。
【０００３】
図１０は以前に発明者らが提案した反射型光センサの例で、図１０（Ａ）が外観、（Ａ）のＢ−Ｂ断面が同図（Ｂ）である。ガラス繊維入りエポキシ樹脂等で作った基板９に、遮光性樹脂で成形した遮光枠１０を接合してあり、遮光枠１０には貫通穴の窓８が二つある。同図（Ｂ）のごとく、それぞれの窓８の内側で発光素子２と受光素子３を基板９上の導電パターンにダイボンドし、金属線１３でワイヤボンドして、窓８に透光性の封止樹脂１１を充填して両素子を封入してある。基板９の側面の導電部１２はスルーホール技術により円弧状の窪みに導電層を形成したもので、これにより基板９上面の導電パターンを基板下面の端子電極に接続している。発光素子２から出た光は発光素子側の窓８から出て被検出物体を照射し、物体表面からの反射光が受光素子側の窓８から戻って受光素子３に達し、検出が行われる。
【０００４】
図１１の反射型光センサも発明者らが提案したもので、図１１（Ａ）が斜視図、（Ａ）のＢ−Ｂ断面図が同図（Ｂ）である。先の図１０のものと同様に、基板９に発光素子２と受光素子３を実装して金属線１３でワイヤボンドし、これを封止樹脂１１中に封入してあるが、図１０と違って遮光枠１０を用いることをせず、台形の封止樹脂１１の側面を金属のメッキ層などの遮光膜１４で被覆してある。封止樹脂１１の上面は遮光膜がなく、全面が透光面で光が出入りする窓であり、この窓の面積を小さくすることにより検出精度を上げることができる。
【０００５】
図１２は特開平８−２９７０１１号に開示された反射型光センサである。センサヘッド２１は基部２２の貫通穴２３、２４に一対の光ファイバー２５、２６をそれぞれ通して、圧力ばめあるいは接着等で保持する構造である。光ファイバー２５は出力端部２７を有し、他端が光源２９に接続される。一方、光ファイバー２６は入力端部２８を有し、他端が光強度検出手段３０に接続される。光ファイバーの出力端部２７と入力端部２８の端面は光ファイバーの軸線に対し斜めに削ってあり、互いに接触するか、あるいはそれに近い程度に接近して配置されている。このセンサヘッド２１を物体３１に近づけると、光源２９から出た光が光ファイバー２５を経て出力端２７から出射されて物体３１に当たり、物体３１の表面からの反射光が入力端部２８から光ファイバー２６に入り、光強度検出手段３０に伝えられて検出されるのである。
【０００６】
【発明が解決しようとする課題】
上述のような従来の反射型光センサのうち、図１０および図１１のものは構造簡単で、大きな集合基板を用いて製作することが可能である。すなわち集合基板上に個々の基板９となる多数の領域を縦横に行列状に配置して、多数個分の発光素子２と受光素子３を実装した後、集合基板に集合遮光枠を接着して集合遮光枠の窓に封止樹脂１１を充填したり、あるいは集合遮光枠を用いず、基板全面に封止樹脂１１を充填して封止樹脂層だけを斜面を形成しながらハーフダイシングし、封止樹脂１１の側面に遮光膜１４をメッキしたりしてから、全体をカッターで縦横にダイシングすれば、切り落とされた各部分が個別の反射型光センサになる。従って非常に生産性がよいが、光が封止樹脂中で散乱したり吸収されたりするので、検出感度や検出精度等の性能や、光の利用効率はあまり高くすることができない。
【０００７】
また、図１２のものは光ファイバー２５、２６を用いていて光をこれに閉じ込めるので、検出性能や光の利用効率を高めることはできるが、センサヘッド２１の構成として、基部２２の貫通穴２３、２４に光ファイバー２５、２６を挿入したりせねばならず、また光ファイバー２５、２６の他端を光源２９や光強度検出手段３０に連結する構造も必要であって、１個ずつ個別に作らねばならず、先の図１０や図１１のもののように集合的に能率よく製作することができなくてコスト高になる。
本発明はこれらの問題を解決して、簡単な構造で光ファイバーを用いて高性能化した反射型光センサと、これを集合基板を用いた多数個取により廉価に製作する方法を実現するものである。
【０００８】
【課題を解決するための手段】
本発明のフォトリフレクタは、基板上に発光素子と受光素子を実装して透光性の封止樹脂中に封入してあり、この点は図１０や図１１のものと共通するが、その上に発光側と受光側の２本の光ファイバーを樹脂中にインサートしたセンサヘッドを積層して構成する点が異なる。なお、両光素子が直接作用し合うことを防ぐために、基板上、両素子の間に遮光板を置いて上記の封止樹脂を分離してある。樹脂に封入した２本の光ファイバーは樹脂の上下面を貫通していて、光ファイバーの上下端面がセンサヘッド上下面の一部になっている。
【０００９】
前記２本の光ファイバーの端面は、センサヘッドの表面では接近していてほぼ隣接しており、反対側である前記封止樹脂との接合面では互いに離れていて、それぞれ前記発光素子および受光素子に面している。従って、両光ファイバーの軸線をそれぞれ含む互いに平行な２平面の方向への両軸線の投影がある角度で交わっている。そして、これら平行な２平面間の距離は少なくとも両光ファイバーの半径の和以上である。すなわち、かりに両光ファイバーをそれらの端面以上に延長した場合、両光ファイバーは互いに突き当たらずにすれ違う。
【００１０】
このような反射型光センサの製造は、大型の集合基板であって縦横に分割すると多数の反射型光センサの基板になるもの、例えば１００〜２００ｍｍ角の集合基板を用いて行う。集合基板の導電パターン面に多数の発光素子と受光素子を実装し、発光素子と受光素子の間の基板上に遮光板を土手状に接着する。そして集合基板の全面に、透光性の封止樹脂を遮光板とほぼ同じ高さに充填して、これらの素子群を封入する。この上に発光素子、受光素子と位置を合わせて、光ファイバーを封入した樹脂のセンサヘッドを接着するが、このセンサヘッドも光センサ１個分のものを多数配置するのでなく、何個分も１列につながった集合センサヘッドを必要な数だけ並べて用いる。こうしてできた集合体を縦横に切断して発光素子と受光素子、および発光側光ファイバーと受光側光ファイバーが対になった領域別に分割すれば、各小片がそれぞれ反射型光センサの完成品になる。
【００１１】
上記のように、集合基板による反射型光センサの製造においては、センサヘッドが何個分も１列につながった集合センサヘッドを用いるが、本発明ではこのような集合センサヘッドを次の方法で能率よく製作する。すなわち樹脂の成形用の型あるいは容器に、１個のセンサヘッドの封入長さの何倍もの長さの光ファイバーを複数本ずつ２列に取り付ける。取り付け方は各列内では光ファイバーが互いに平行で所定の一定間隔をとり、列間では光ファイバーが前記一定の角度で交差しながら互いにほぼ接するようにしたもので、これに樹脂を注入して固化する。従って、多くの光ファイバーが筋交い状に封入された樹脂板が得られる。この樹脂板を光ファイバー同士の交点を結んで通る平行線群、およびこれらの平行線群の中間を通る平行線群に沿ってカッターで短冊状に切断、分割すれば、短冊状の各片が集合基板への取り付け用の集合センサヘッドになる。
これらの方法により、反射型光センサを多数個取りで能率よく製造できる。
【００１２】
【発明の実施の形態】
以下、図面に基づいて本発明の実施形態を説明する。なお、前記の説明を含め、同種の部品や部分については同じ符号を用いることにする。
図１は本発明の反射型光センサの第１の実施形態で、同図（Ａ）は透視的な斜視図である。基板９上に発光素子２と受光素子３をそれぞれ実装し、両素子の間に遮光板４１を設けて両素子が直接影響し合うことを防ぎ、これらを透光性の封止樹脂１１中に封入してある。その上にセンサヘッド４２を接合して積層してあり、センサヘッド４２は樹脂４３中に発光側の光ファイバー４４と受光側の光ファイバー４５をインサートしたもので、光ファイバー４４、４５は樹脂４３を貫通して両端面が樹脂４３の上下面の一部として露出している。
【００１３】
図１（Ｂ）は同図（Ａ）の左手前から見た正面図、（Ｃ）は（Ａ）の上面図で、いずれも透視的に描いてある。これらの図に見るように、基板９の導電パターン１５に発光素子２と受光素子３をダイボンドし、金属線１３でワイヤボンドしてある。１６は基板上面の端子電極であるが、基板側面の導電部１２により、図では見えないが基板９の下面に設けた端子電極に接続されている。基板下面の端子電極は、反射型光センサを他の機器の回路基板に実装するためのもので、このように本発明の反射型光センサは回路基板への表面実装に適する形式である。導電部１２は基板９の縁部に設けた円弧状の窪みの表面が導電膜を持つものであるが、製造工程ではこの部分は全円のスルーホールだったのである。
【００１４】
図に見るように、光ファイバー４４と４５は一定の角度で交差しており、センサヘッド４２と封止樹脂１１の接合面では光ファイバーの端面が発光素子２と受光素子３にそれぞれ面していて、センサヘッド４２の上面では光ファイバーの端面が互いに接近してほぼ隣接している。これにより、センサヘッド４２の上面を被検出物体に近づけると、発光素子２から出た光が光ファイバー４４を通って物体の表面を照射し、反射光が隣接する光ファイバー４５の端面から入ってセンサ内に戻り、受光素子３によって検出されるのである。
【００１５】
本発明の特徴として、２本の光ファイバー４４、４５を次のように配置する。すなわち図１（Ｃ）に見るように、光ファイバー４４と４５の軸線をそれぞれ通って互いに平行な二つの平面を想定した時、この２平面間の距離ａが２本の光ファイバーのそれぞれの半径の和と同等以上であり、従って両光ファイバーの直径が同じならａが直径と同寸法以上であることで、簡単に言えば、両光ファイバーを延長したとき、互いに突き当たらずにすれ違うことである。２本の光ファイバーの交差角は、焦点距離や光変換効率等を考慮して任意に決定する。この構成を取ることにより、後述するように極めて便利な製造方法が可能になる。
【００１６】
図１の反射型光センサの実施形態では、発光素子２と受光素子３を封入している透光性の封止樹脂１１層が反射型光センサの側面に露出しているので、発光素子２から出た光や受光素子３に戻ってきた光の一部が封止樹脂１１で散乱して側面から漏れることがある。このような漏れをなくして光の利用効率や検出感度を上げ、他の部品との干渉を防ぐようにしたのが、図２に示す第２の実施形態である。ここでは基板９上に遮光性樹脂の遮光枠４６を設けて、封止樹脂１１が光センサ側面に露出しないようにしている。遮光枠４６には二つの大きな貫通穴があって、それぞれの穴に発光素子２と受光素子３を収容し、これらの穴に封止樹脂１１を充填して各素子を封入する。これにより光センサ側面からの光の漏れがなくなる。遮光枠４６の二つの貫通穴の間の壁の部分は、図１における遮光板４１と同じく、発光素子２と受光素子３が直接作用し合うのを防ぐ。
【００１７】
図３は本発明の第３の実施形態で、同じく光センサ側面からの光漏れを防ぐ構造である。図１の第１の実施形態の構成をそのまま含むものであるが、光センサ側面に現れた封止樹脂の表面に遮光材料の薄層からなる遮光膜４７を被覆してある。遮光膜４７は例えば無電解メッキによるニッケルメッキ膜であり、これによって光漏れが防がれる。
【００１８】
次に、図４以下を参照しながら本発明の反射型光センサの製造方法を説明する。
図４にて、まず大型の集合基板５１を用意する。これは完成時に個々の反射型光センサとなる多数の領域を縦横に行列状に配列して、導電パターン１５やスルーホール５２を設けたもので、縦横の分割線５３、５４によって区分される１区画が１個の反射型光センサに相当する。そして発光素子２群と受光素子３群を導電パターン１５にダイボンドし、金属線１３でワイヤボンドする。集合基板の材質は黒色素を混合したガラス繊維入りエポキシ樹脂などであって、例えば寸法が１００〜２００ｍｍ角の集合基板であれば、１，０００個前後の反射型光センサに分割することができる。
【００１９】
次に、集合遮光板５５を集合基板５１に接着する。集合遮光板５１は遮光性樹脂の成形品で何本もの横棒５５ａがある枠状であり、横棒５５ａの部分が後に図１の遮光板４１になる。集合基板５１上に２点鎖線５６で示したのは、集合遮光板５５の合わせ位置である。集合基板５１上の１区画には発光素子２と受光素子３が１個ずつ含まれて、集合遮光板５５の横棒５５ａで隔てられた配置となる。
【００２０】
次に、集合基板５１上に接着した集合遮光板５５の横棒５５ａの間にエポキシ樹脂等の透光性樹脂を注入し、集合遮光板５５の上面とほぼ同じ高さに充填する。集合遮光板５５は、ワイヤボンドした発光素子２や受光素子３の金属線１３を含めた高さよりも高いものを用いるので、このように樹脂を充填することにより各素子は金属線も含めて完全に樹脂中に封入される。こうして充填した樹脂が図１の封止樹脂１１となる。封止樹脂注入の際、集合基板５１のスルーホール５２から樹脂が流れ出たりしないよう、必要に応じてスルーホールをテープ材で塞ぐなどの処理をしておく。
【００２１】
次に、このように集合遮光板５５の横棒５５ａ間に封止樹脂を充填した上に集合センサヘッド５７を接着する。集合センサヘッド５７は、図１に見られるセンサヘッド４２を何個分も横に１列につないだ形の直方体である。従って集合センサヘッド５７は１対の発光側光ファイバー４４と受光側光ファイバー４５を何対も含んでいる。集合基板５５に封止樹脂を充填した上に接着剤を塗布し、光ファイバー４４、４５の下端面を発光素子２と受光素子３に合わせながら、集合センサヘッド５７を何個も並べて接着する。光ファイバー４４、４５の下端面には接着剤がつかないように、封止樹脂上面への接着剤の塗布は発光素子２や受光素子３から離れた位置に行う。接着剤の塗布は任意の方法で行えばよいが、不要箇所に接着剤がつかないように封止樹脂面上にマスク材をあてがって塗布するのが便利である。スクリーン印刷によるのもよい。図４にて、分割線５３ａ、５４ａで区分される集合センサヘッド５７の１区画が、図１における１個のセンサヘッド４２になる。
【００２２】
集合基板５１と集合遮光板５５と集合センサヘッド５７を、中間に封止樹脂の充填工程を伴って積層した集合体を、分割線５３、５４（すなわち５３ａ、５４ａ）に沿って切断するダイシングを行えば、得られる各小片がそれぞれ反射型光センサの完成品になる。図４の集合基板５１に設けてあったスルーホール５２は、図１の完成品では窪みに導電材が被覆された導電部１２となる。このようにして、本発明の反射型光センサは多数個取りにより極めて能率よく製作することができる。
【００２３】
上記の説明は図１に示した第１の実施形態のものの製造方法であるが、図２の遮光枠４６を備えた第２の実施形態のものも、集合部品を用いて同様の工程により製作される。ただし、その場合、図４の集合遮光板５５でなく、図５に示す集合遮光枠５８を用いる。これは形が格子状でいくつも窓があり、分割線５３ｂ、５４ｂによる１区画が完成品１個分である。遮光枠５８を図４の集合基板５１に接着し、窓枠内に封止樹脂を充填して、発光素子２と受光素子３を封入する。そして前述のように集合センサヘッド５７を接合した集合体を作ってダイシングすれば、集合遮光枠５８は図５の分割線５３ｂ、５４ｂで切り離されて、図２のごとく封止樹脂１１の周辺が遮光枠４６で囲われて光の漏れない反射型光センサが得られる。
【００２４】
図３に示すような、封止樹脂１１の側面に遮光膜４７を被覆した反射型光センサの製作は、図１の実施形態のものを前述の方法で製作した単品について、側面に現れた封止樹脂１１表面に遮光膜を被覆して行ってもよいが、やはり集合基板工程に含めるのがはるかに能率的である。図１の実施形態のものと同じく、各集合部品を積層するまでを図４に示す工程によって行う。そして集合部品を積層した集合体ができたら、まず、上方から分割線５３ａ、５４ａに沿って、集合センサヘッド５７とその下部の封止樹脂層を基板に達するまでハーフ・ダイシングする。これで、集合基板５１はまだ一体のままであるが、封止樹脂とセンサヘッドには側面を生じるから、無電解ニッケルメッキにより集合体をメッキ液に浸漬してニッケル被膜を作るなどして、図３のごとく封止樹脂１１の側面に遮光膜４７を形成する。
【００２５】
この時、遮光膜不要部分はマスクしておくのであり、例えば集合基板裏面の端子電極やスルーホール内面の導電部に遮光膜材料が被覆されないよう、集合基板２１の裏面にはマスク用のシート材などを貼付しておく。センサヘッド上面はもとより遮光膜を設けないが、この面についてはマスクしてメッキを防ぐ方法のほか、側面とともにメッキした後にエッチング等によってメッキ層を除去する方法を取ってもよい。反射型光センサの側面で遮光膜４７が必要なのは図３に示すように封止樹脂１１の層であるが、センサヘッド４２の側面をマスクしてメッキを防ぐのは不便であり、またメッキを防ぐ必要もないから、光センサ側面はセンサヘッド４２も含めて遮光膜を形成して差し支えない。この後、集合基板５１を分割線５３、５４に従ってフル・ダイシングすれば、図３の反射型光センサが完成する。
【００２６】
図１ないし図３に見るように、本発明の反射型光センサのセンサヘッド４２はサイコロ状の樹脂４３に光ファイバー４４、４５がインサートされたものであるが、図４に示す集合基板５１を用いた製造工程で使用するのは、センサヘッドが何個もつながった集合センサヘッド５７であり、以下、集合センサヘッド５７を製作する方法を説明する。まず、図６に示すように、樹脂４３中に反射型光センサの完成品に含まれる光ファイバーの何倍もの長さの光ファイバー４４群と４５群をインサート成形した集合センサヘッド板５９を製作する。同図（Ａ）は上面図、同図（Ｂ）は正面図である。
【００２７】
光ファイバー４４同士と光ファイバー４５同士はそれぞれ平行で間隔一定であり、そして光ファイバー４４群と光ファイバー４５群は一定の角度で交差している。交差の角度は図１（Ｂ）における光ファイバー４４と光ファイバー４５の交差角と同じである。図６（Ｂ）に分割線６０を描いてあるが、これは正面から見て光ファイバー群の交点を通る平行線群とその中間の平行線群で、分割線６０の間隔は一様である。分割線６０に沿った平行な光ファイバー群のピッチは、図４の集合基板５１の分割線５４の間隔に等しくする。。
【００２８】
図６（Ａ）に現れている集合センサヘッド板５９の厚さは、図１（Ｃ）における反射型光センサの上下幅に等しい。図６（Ａ）の距離ａは光ファイバー４４群の軸線を含む平面と光ファイバー４５群の軸線を含む平面間の距離であるが、これは図１（Ｃ）のａと同じであって両光ファイバーの半径の和にほぼ等しく、光ファイバー４４群と光ファイバー４５群は互いにほぼ接して交差している。このような集合センサヘッド板５９は、光ファイバー４４群と光ファイバー４５群を交差させて取り付けた成形用の型または容器に樹脂を注入、固化して製作する。
【００２９】
次いで集合センサヘッド板５９を分割線６０に沿ってカッターで切断する。この切断は切断面に現れる光ファイバー端面の仕上げ加工を兼ねるので精密に行う。集合センサヘッド板５９を何枚も重ねて固定したものを切断すれば、能率よく切断することができる。
【００３０】
集合センサヘッド板５９を分割線６０に沿って切断して得られる直方体片に、図６にて上から順に１、２、３．．．と番号をつけ、奇数番目のものを上下裏返し、図７に示すように各直方体を左右にずらして揃えると、各直方体を縦の分割線６１で区分した各部分は同じものであり、それぞれ１個のセンサヘッドに相当する。従って図７の各直方体が図４の集合基板工程で用いる集合センサヘッド５７となる。こうして図６のような集合センサヘッド板５９を作って分割することにより、集合センサヘッド５７を能率よく製作できる。なお、図６（Ｂ）の分割線６０について、前記のように正面から見て光ファイバー群の交点を通る平行線群とその中間の平行線群と定義すると、それに該当する平行線は分割線６０に直交する縦方向にも引けるわけであるが、どちらを取るべきかは自明である。
【００３１】
図６の集合センサヘッド板５９の考えをさらに進めたのが、図８の集合センサヘッド・ブロック６２である。これは集合センサヘッド板５９を何枚も重ねて一体化したような形で光ファイバー４４、４５をインサートした樹脂ブロックである。図８（Ａ）は上面図、（Ｂ）は正面図で、（Ａ）に見るように光ファイバー４４群と４５群が交差して対をなすものが何列も含まれている。この集合センサヘッド・ブロック６２を分割線６０で切断しさらに分割線６３で切断すれば、図４の工程に用いる多数の集合センサヘッド５７が得られる。
【００３２】
図８の集合センサヘッド・ブロック６２を用いる場合、図４の集合基板工程に用いるセンサヘッドの集合部品としては、図８（Ａ）の分割線６３では分割せず、同図（Ｂ）の分割線６０で分割しただけの板状のものを、前述の図６の集合センサヘッド板５９の場合のように１枚置きに上下裏返しにして用いればよい。これもまた板状であるが、図６の集合センサヘッド板５９とは違ってこれと直交する方向に広がるものである。図４に描いた集合センサヘッド５７群はそれぞれ別個のもので、分割線５３ａに沿って溝で隔たっているが、上記のような板状のものを用いると、つながっていて溝のない集合センサヘッド板を集合遮光板５５上に接着するのであり、集合体をダイシングする際、分割線５３ａに沿う方向もセンサヘッド層を切断することになる。
【００３３】
図８の集合センサヘッド・ブロック６２によれば１回の成形で非常に多くのセンサヘッドを含む集合部品が得られるが、それとともに成形用の型あるいは容器が複雑化し、これに光ファイバーを取り付ける手間も増えるから、一概にこの方法が有利とは限らない。図６の集合センサヘッド板５９を用いるか図８の集合センサヘッド・ブロック６２を用いるかは、実状に応じて決めるのがよい。
【００３４】
以上、反射型光センサとして完結している回路部品について説明したが、反射型光センサを構成の一部とする回路部品もまた存在する。例えば、光マイクロホンという回路部品があり、これは反射型光センサとそのセンサヘッド近傍に配置した被検出物である振動膜を含めて構成したもので、音響等による振動膜の振動を光信号に変換して処理するものである。本発明の反射型光センサとその製造方法は、光マイクロホンのように構成の一部に反射型光センサを含む部品にも及ぶものである。
【００３５】
【発明の効果】
以上述べたように、本発明によって得られる反射型光センサは光ファイバーで光路を形成するので、光の利用効率が向上して高性能の光センサが得られる。しかも構造簡単であって小型、薄型化に適し、また、製造に関しては集合基板を始めとする集合部品を用いて製造を進め、最後に切断して分割し、一度に多数の製品を得るので極めて生産性が高く、製造コストを低減できる。
このように本発明によれば、超小型、高性能で信頼性が高く、表面実装に適する反射型光センサを廉価に提供できるのである。
【図面の簡単な説明】
【図１】本発明の反射型光センサを透視的に示し、（Ａ）は斜視図、（Ｂ）は正面図、（Ｃ）は上面図である。
【図２】本発明の別の反射型光センサを透視的に示す斜視図である。
【図３】本発明のさらに別の反射型光センサを透視的に示す斜視図である。
【図４】本発明の反射型光センサの製造方法を示す斜視図である。
【図５】本発明の反射型光センサの製造に用いる集合遮光枠の斜視図である。
【図６】本発明の反射型光センサの製造に用いる集合センサヘッド板を示し、（Ａ）は上面図、（Ｂ）は正面図である。
【図７】図６の集合センサヘッド板を分割して得た集合センサヘッドである。
【図８】本発明の反射型光センサの製造に用いる集合センサヘッド・ブロックを示し、（Ａ）は上面図、（Ｂ）は正面図である。
【図９】反射型光センサの原理的構成図である。
【図１０】従来の反射型光センサを示し、（Ａ）は斜視図、（Ｂ）は（Ａ）のＢ−Ｂ断面図である。
【図１１】従来の別の反射型光センサを示し、（Ａ）は斜視図、（Ｂ）は（Ａ）のＢ−Ｂ断面図である。
【図１２】従来のさらに別の反射型光センサの図面である。
【符号の説明】
２発光素子
３受光素子
８窓
９基板
１０、４６遮光枠
１１封止樹脂
１２導電部
１４、４７遮光膜
１５導電パターン
１６端子電極
２１、４２センサヘッド
２５、２６、４４、４５光ファイバー
４１遮光板
４３樹脂
５１集合基板
５２スルーホール
５５集合遮光板
５７集合センサヘッド
５８集合遮光枠
５９集合センサヘッド板
６２集合センサヘッド・ブロック[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a reflective optical sensor for detecting reflected light from the surface of an object to be detected and a method for manufacturing the same.
[0002]
[Prior art]
A reflection type optical sensor is a sensor that detects the presence or absence of an object in a non-contact manner, and is used for control of a rotating body such as a motor, and detection of positions and edges of paper and film. FIG. 9 shows a principle configuration of a reflection type photosensor. A light emitting element 2 (for example, an infrared LED) and a light receiving element 3 (for example, a phototransistor) are accommodated in a package 1, and light is emitted from the light emitting element 2. The light receiving element 3 detects that the light is emitted as indicated by the arrow and reflected by the object 4 to be detected. As a result, the output from the light receiving element 3 changes according to the presence or absence and position of the object 4 in the vicinity of the reflective optical sensor, and this is used as a detection signal.
[0003]
FIG. 10 shows an example of a reflection type optical sensor previously proposed by the inventors. FIG. 10A is an external view, and FIG. A light shielding frame 10 formed of a light shielding resin is bonded to a substrate 9 made of glass fiber epoxy resin or the like, and the light shielding frame 10 has two windows 8 with through holes. As shown in FIG. 2B, the light emitting element 2 and the light receiving element 3 are die-bonded to the conductive pattern on the substrate 9 inside each window 8, and wire-bonded with a metal wire 13, so that the window 8 has a light-transmitting seal. Both elements are filled with a stop resin 11. The conductive portion 12 on the side surface of the substrate 9 is formed by forming a conductive layer in an arc-shaped depression by a through-hole technique, thereby connecting the conductive pattern on the upper surface of the substrate 9 to the terminal electrode on the lower surface of the substrate 9. Light emitted from the light emitting element 2 exits the window 8 on the light emitting element side and irradiates the object to be detected, and reflected light from the object surface returns from the window 8 on the light receiving element side and reaches the light receiving element 3 for detection. .
[0004]
The reflection type optical sensor of FIG. 11 is also proposed by the inventors. FIG. 11A is a perspective view, and FIG. 11A is a cross-sectional view taken along line BB of FIG. As in the previous FIG. 10, the light emitting element 2 and the light receiving element 3 are mounted on the substrate 9 and wire-bonded with the metal wire 13 and sealed in the sealing resin 11. The side surface of the trapezoidal sealing resin 11 is covered with a light shielding film 14 such as a metal plating layer without using the light shielding frame 10. The upper surface of the sealing resin 11 has no light-shielding film, and the entire surface is a light-transmitting surface and is a window through which light enters and exits. Detection accuracy can be increased by reducing the area of this window.
[0005]
FIG. 12 shows a reflection type optical sensor disclosed in Japanese Patent Laid-Open No. 8-297711. The sensor head 21 has a structure in which a pair of optical fibers 25 and 26 are passed through the through holes 23 and 24 of the base 22 and are held by pressure fitting or adhesion. The optical fiber 25 has an output end 27, and the other end is connected to the light source 29. On the other hand, the optical fiber 26 has an input end portion 28, and the other end is connected to the light intensity detection means 30. The end faces of the output end 27 and the input end 28 of the optical fiber are cut obliquely with respect to the axis of the optical fiber, and are arranged close to each other or close to each other. When the sensor head 21 is brought close to the object 31, the light emitted from the light source 29 is emitted from the output end 27 through the optical fiber 25 and hits the object 31, and the reflected light from the surface of the object 31 passes from the input end 28 to the optical fiber 26. It is transmitted to the light intensity detecting means 30 and detected.
[0006]
[Problems to be solved by the invention]
Among the conventional reflective optical sensors as described above, those shown in FIGS. 10 and 11 have a simple structure and can be manufactured using a large collective substrate. That is, a large number of regions to be the individual substrates 9 are arranged in rows and columns on the collective substrate, and a large number of light emitting elements 2 and light receiving elements 3 are mounted, and then a collective light shielding frame is bonded to the collective substrate. Filling the window of the collective light shielding frame with the sealing resin 11 or filling the entire surface of the substrate with the sealing resin 11 without using the collective light shielding frame and half-dicing only the sealing resin layer while forming the inclined surface. If the light shielding film 14 is plated on the side surface of the stop resin 11 and then the whole is vertically and horizontally diced with a cutter, each cut-off portion becomes an individual reflective optical sensor. Therefore, although productivity is very good, since light is scattered and absorbed in the sealing resin, the performance such as detection sensitivity and detection accuracy, and the utilization efficiency of light cannot be made very high.
[0007]
12 uses optical fibers 25 and 26 to confine light therein, so that the detection performance and the light utilization efficiency can be improved. However, as a configuration of the sensor head 21, the through hole 23 of the base portion 22, In addition, optical fibers 25 and 26 must be inserted into 24, and a structure in which the other ends of the optical fibers 25 and 26 are connected to the light source 29 and the light intensity detecting means 30 is also necessary. However, unlike the ones shown in FIGS. 10 and 11, it cannot be manufactured collectively and efficiently, resulting in an increase in cost.
The present invention solves these problems, and realizes a reflective optical sensor with a simple structure and high performance using an optical fiber, and a method for inexpensively manufacturing the same by using a collective substrate. is there.
[0008]
[Means for Solving the Problems]
The photo reflector of the present invention has a light emitting element and a light receiving element mounted on a substrate and encapsulated in a translucent sealing resin. This point is the same as that shown in FIGS. The difference is that a sensor head in which two optical fibers on the light emitting side and the light receiving side are inserted in a resin is laminated. In order to prevent the two optical elements from directly acting on each other, the sealing resin is separated by placing a light shielding plate on the substrate between the two elements. The two optical fibers sealed in the resin penetrate the upper and lower surfaces of the resin, and the upper and lower end surfaces of the optical fiber are part of the upper and lower surfaces of the sensor head.
[0009]
The end surfaces of the two optical fibers are close to each other on the surface of the sensor head and are substantially adjacent to each other, and are separated from each other at the joint surface with the sealing resin on the opposite side, and are respectively connected to the light emitting element and the light receiving element. Facing. Therefore, the projections of the two axes intersect at a certain angle in the directions of two parallel planes including the axes of the two optical fibers. The distance between these two parallel planes is at least the sum of the radii of both optical fibers. That is, when both optical fibers are extended beyond their end faces, the two optical fibers pass each other without hitting each other.
[0010]
Such a reflective photosensor is manufactured using a large collective substrate that becomes a substrate of a large number of reflective photosensors when divided vertically and horizontally, for example, a 100 to 200 mm square collective substrate. A large number of light emitting elements and light receiving elements are mounted on the conductive pattern surface of the collective substrate, and a light shielding plate is bonded in a bank shape on the substrate between the light emitting elements and the light receiving elements. The entire surface of the collective substrate is filled with translucent sealing resin at substantially the same height as the light shielding plate, and these element groups are sealed. A resin sensor head in which an optical fiber is enclosed is bonded to the light emitting element and the light receiving element on the top, and this sensor head is not arranged with a large number of one optical sensor, but one for several. Use as many collective sensor heads connected to a line as necessary. If the assembly thus formed is cut vertically and horizontally and divided into regions where the light emitting element and the light receiving element, and the light emitting side optical fiber and the light receiving side optical fiber are paired, each piece becomes a finished product of the reflection type photosensor.
[0011]
As described above, in the production of a reflective optical sensor using an aggregate substrate, an aggregate sensor head in which a number of sensor heads are connected in a row is used. In the present invention, such an aggregate sensor head is formed by the following method. Produces efficiently. That is, a plurality of optical fibers having a length several times the enclosed length of one sensor head are attached in two rows to a resin molding die or container. In each row, the optical fibers are parallel to each other and have a predetermined fixed interval, and between the rows, the optical fibers cross each other at the predetermined angle so as to be almost in contact with each other. . Therefore, a resin plate in which many optical fibers are enclosed in a bracing shape is obtained. If this resin plate is cut and divided into strips with a cutter along a group of parallel lines passing through the intersection of optical fibers and a group of parallel lines passing through the middle of these groups of parallel lines, each strip-shaped piece is assembled. It becomes a collective sensor head for mounting on a substrate.
By these methods, it is possible to efficiently manufacture a large number of reflective optical sensors.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, the same code | symbol is used about the same kind components and parts including the said description.
FIG. 1 is a perspective view of a first embodiment of a reflective photosensor according to the present invention. FIG. 1 (A) is a perspective view. The light-emitting element 2 and the light-receiving element 3 are mounted on the substrate 9 and a light-shielding plate 41 is provided between the two elements to prevent the two elements from directly affecting each other. Enclosed. A sensor head 42 is bonded and laminated thereon, and the sensor head 42 is obtained by inserting a light-emitting side optical fiber 44 and a light-receiving side optical fiber 45 into a resin 43, and the optical fibers 44 and 45 penetrate the resin 43. Both end surfaces are exposed as part of the upper and lower surfaces of the resin 43.
[0013]
FIG. 1B is a front view as seen from the left front side of FIG. 1A, and FIG. 1C is a top view of FIG. As shown in these drawings, the light-emitting element 2 and the light-receiving element 3 are die-bonded to the conductive pattern 15 of the substrate 9 and wire-bonded with a metal wire 13. Reference numeral 16 denotes a terminal electrode on the upper surface of the substrate, which is connected to a terminal electrode provided on the lower surface of the substrate 9 by a conductive portion 12 on the side surface of the substrate, which is not visible in the drawing. The terminal electrode on the lower surface of the substrate is for mounting the reflective photosensor on a circuit board of another device, and thus the reflective photosensor of the present invention is in a form suitable for surface mounting on a circuit board. The conductive part 12 has a conductive film on the surface of the arc-shaped depression provided at the edge of the substrate 9, but in the manufacturing process, this part was a full-circular through hole.
[0014]
As shown in the figure, the optical fibers 44 and 45 intersect at a certain angle, and the end face of the optical fiber faces the light emitting element 2 and the light receiving element 3 at the joint surface of the sensor head 42 and the sealing resin 11, respectively. On the upper surface of the sensor head 42, the end faces of the optical fibers are close to each other and are almost adjacent to each other. As a result, when the upper surface of the sensor head 42 is brought close to the object to be detected, the light emitted from the light emitting element 2 irradiates the surface of the object through the optical fiber 44 and the reflected light enters from the end face of the adjacent optical fiber 45 and enters the sensor. Then, the light receiving element 3 detects the light.
[0015]
As a feature of the present invention, the two optical fibers 44 and 45 are arranged as follows. That is, as shown in FIG. 1C, when assuming two planes parallel to each other through the axes of the optical fibers 44 and 45, the distance a between the two planes is the sum of the radii of the two optical fibers. Therefore, if the diameters of both optical fibers are the same, a is equal to or larger than the diameter. In short, when both optical fibers are extended, they pass each other without colliding with each other. The crossing angle of the two optical fibers is arbitrarily determined in consideration of the focal length, light conversion efficiency, and the like. By adopting this configuration, a very convenient manufacturing method becomes possible as will be described later.
[0016]
In the embodiment of the reflective photosensor of FIG. 1, the light-transmitting sealing resin 11 layer enclosing the light emitting element 2 and the light receiving element 3 is exposed on the side surface of the reflective photosensor. A part of the light emitted from the light or returned to the light receiving element 3 may be scattered by the sealing resin 11 and leak from the side surface. The second embodiment shown in FIG. 2 eliminates such leakage to increase the light utilization efficiency and detection sensitivity and prevent interference with other components. Here, a light shielding frame 46 made of a light shielding resin is provided on the substrate 9 so that the sealing resin 11 is not exposed to the side surface of the optical sensor. The light shielding frame 46 has two large through holes. The light emitting element 2 and the light receiving element 3 are accommodated in the respective holes, and the sealing resin 11 is filled in these holes to enclose each element. This eliminates light leakage from the side surface of the optical sensor. The portion of the wall between the two through holes of the light shielding frame 46 prevents the light emitting element 2 and the light receiving element 3 from directly acting like the light shielding plate 41 in FIG.
[0017]
FIG. 3 shows a third embodiment of the present invention, which similarly has a structure for preventing light leakage from the side surface of the optical sensor. Although including the configuration of the first embodiment of FIG. 1 as it is, the light shielding film 47 made of a thin layer of a light shielding material is coated on the surface of the sealing resin appearing on the side surface of the optical sensor. The light shielding film 47 is, for example, a nickel plating film by electroless plating, thereby preventing light leakage.
[0018]
Next, the manufacturing method of the reflective optical sensor of the present invention will be described with reference to FIG.
In FIG. 4, first, a large aggregate substrate 51 is prepared. This is a structure in which a large number of regions that become individual reflection type photosensors are arranged in a matrix in the vertical and horizontal directions when completed, and are provided with conductive patterns 15 and through holes 52, which are divided by vertical and horizontal dividing lines 53 and 54. The section corresponds to one reflection type photosensor. Then, the light emitting element 2 group and the light receiving element 3 group are die-bonded to the conductive pattern 15 and wire-bonded with the metal wire 13. The material of the collective substrate is an epoxy resin with glass fiber mixed with black pigment, and for example, if the collective substrate has a dimension of 100 to 200 mm square, it can be divided into about 1,000 reflective optical sensors. .
[0019]
Next, the collective light shielding plate 55 is bonded to the collective substrate 51. The collective light shielding plate 51 is a molded product of light shielding resin and has a frame shape with a number of horizontal bars 55a, and the portion of the horizontal bars 55a later becomes the light shielding plate 41 of FIG. What is indicated by a two-dot chain line 56 on the collective substrate 51 is an alignment position of the collective light shielding plate 55. One section on the collective substrate 51 includes one light-emitting element 2 and one light-receiving element 3, and is arranged separated by a horizontal bar 55 a of the collective light shielding plate 55.
[0020]
Next, a light-transmitting resin such as an epoxy resin is injected between the horizontal bars 55 a of the collective light shielding plate 55 bonded onto the collective substrate 51 and filled to the same height as the upper surface of the collective light shield plate 55. Since the aggregate light shielding plate 55 is higher than the height including the metal wire 13 of the light-emitting element 2 and the light-receiving element 3 that are wire-bonded, each element including the metal line is completely filled by filling the resin in this way. Encapsulated in resin. The resin thus filled becomes the sealing resin 11 in FIG. When the sealing resin is injected, a process such as closing the through hole with a tape material is performed as necessary so that the resin does not flow out of the through hole 52 of the collective substrate 51.
[0021]
Next, after the sealing resin is filled between the horizontal bars 55a of the collective light shielding plate 55, the collective sensor head 57 is bonded. The collective sensor head 57 is a rectangular parallelepiped having a number of sensor heads 42 shown in FIG. Accordingly, the collective sensor head 57 includes a plurality of pairs of light-emitting side optical fibers 44 and light-receiving side optical fibers 45. The assembly substrate 55 is filled with a sealing resin, and an adhesive is applied. The assembly sensor heads 57 are arranged and bonded together while aligning the lower end surfaces of the optical fibers 44 and 45 with the light emitting element 2 and the light receiving element 3. The adhesive is applied to the upper surface of the sealing resin at a position away from the light-emitting element 2 and the light-receiving element 3 so that the adhesive does not adhere to the lower end surfaces of the optical fibers 44 and 45. The adhesive may be applied by an arbitrary method, but it is convenient to apply the adhesive by applying a mask material on the sealing resin surface so that the adhesive does not adhere to unnecessary portions. It may be by screen printing. In FIG. 4, one section of the collective sensor head 57 divided by the dividing lines 53a and 54a becomes one sensor head 42 in FIG.
[0022]
Dicing is performed by cutting an assembly in which the assembly substrate 51, the assembly light shielding plate 55, and the assembly sensor head 57 are laminated together with a sealing resin filling process along the dividing lines 53 and 54 (that is, 53a and 54a). If it does, each small piece obtained will be a finished product of a reflection type photosensor. The through hole 52 provided in the collective substrate 51 of FIG. 4 becomes the conductive part 12 in which the conductive material is covered in the depression in the finished product of FIG. Thus, the reflection type photosensor of the present invention can be manufactured very efficiently by taking a large number of pieces.
[0023]
The above description is the manufacturing method of the first embodiment shown in FIG. 1, but the second embodiment including the light shielding frame 46 of FIG. 2 is also manufactured by the same process using the assembly parts. Is done. In this case, however, the collective light shielding frame 58 shown in FIG. 5 is used instead of the collective light shielding plate 55 shown in FIG. This has a lattice shape and a number of windows, and one section by dividing lines 53b and 54b is one finished product. The light shielding frame 58 is bonded to the collective substrate 51 of FIG. 4, the sealing resin is filled in the window frame, and the light emitting element 2 and the light receiving element 3 are sealed. Then, if an assembly in which the assembly sensor head 57 is joined as described above is made and diced, the assembly light shielding frame 58 is separated by the dividing lines 53b and 54b in FIG. 5, and the periphery of the sealing resin 11 as shown in FIG. A reflective optical sensor surrounded by the light shielding frame 46 and free of light leakage is obtained.
[0024]
As shown in FIG. 3, the reflection type photosensor in which the side surface of the sealing resin 11 is covered with the light shielding film 47 is manufactured by using the sealing method appearing on the side surface of the single product manufactured by the above-described method. Although the surface of the stop resin 11 may be coated with a light shielding film, it is much more efficient to include it in the collective substrate process. Similar to the embodiment of FIG. 1, the process up to stacking the assembly parts is performed by the process shown in FIG. 4. When the assembly in which the assembly parts are laminated is completed, first, the assembly sensor head 57 and the sealing resin layer below the assembly sensor head 57 are half-diced along the dividing lines 53a and 54a from the top until reaching the substrate. As a result, the collective substrate 51 is still integrated, but the sealing resin and the sensor head have side surfaces, so that the aggregate is immersed in a plating solution by electroless nickel plating to form a nickel coating, etc. A light shielding film 47 is formed on the side surface of the sealing resin 11 as shown in FIG.
[0025]
At this time, unnecessary portions of the light shielding film are masked. For example, a mask sheet material is provided on the back surface of the collective substrate 21 so that the terminal electrode on the back surface of the collective substrate and the conductive portion on the inner surface of the through hole are not covered with the light shield film material. Affix such as. Although the upper surface of the sensor head is not provided with a light-shielding film, this surface may be masked to prevent plating, or a method of removing the plating layer by etching or the like after plating together with the side surface. The light shielding film 47 is required on the side surface of the reflection type photosensor as shown in FIG. 3, but it is inconvenient to mask the side surface of the sensor head 42 to prevent plating. Since there is no need to prevent it, a light shielding film may be formed on the side surface of the optical sensor including the sensor head 42. Thereafter, if the collective substrate 51 is fully diced according to the dividing lines 53 and 54, the reflection type photosensor of FIG. 3 is completed.
[0026]
As shown in FIG. 1 to FIG. 3, the sensor head 42 of the reflection type photosensor of the present invention is formed by inserting optical fibers 44 and 45 into a dice-shaped resin 43, but the collective substrate 51 shown in FIG. 4 is used. The collective sensor head 57 in which a number of sensor heads are connected is used in the manufacturing process, and a method for manufacturing the collective sensor head 57 will be described below. First, as shown in FIG. 6, a collective sensor head plate 59 in which an optical fiber 44 group and a 45 group having a length several times the optical fiber included in the finished product of the reflection type optical sensor is insert-molded in the resin 43 is manufactured. FIG. 4A is a top view and FIG. 4B is a front view.
[0027]
The optical fibers 44 and the optical fibers 45 are parallel to each other with a constant spacing, and the optical fiber 44 group and the optical fiber 45 group intersect at a constant angle. The angle of intersection is the same as the angle of intersection of the optical fiber 44 and the optical fiber 45 in FIG. The dividing line 60 is drawn in FIG. 6B. This is a group of parallel lines passing through the intersection of the optical fiber groups as viewed from the front and a group of parallel lines in the middle, and the interval between the dividing lines 60 is uniform. The pitch of the parallel optical fiber groups along the dividing line 60 is set equal to the interval between the dividing lines 54 of the collective substrate 51 in FIG. .
[0028]
The thickness of the collective sensor head plate 59 appearing in FIG. 6A is equal to the vertical width of the reflective photosensor in FIG. The distance a in FIG. 6A is the distance between the plane including the axis of the optical fiber 44 group and the plane including the axis of the optical fiber 45 group, which is the same as a in FIG. The optical fibers 44 and 45 are substantially in contact with each other and intersect each other. Such a collective sensor head plate 59 is manufactured by injecting and solidifying a resin into a molding die or container in which the optical fiber 44 group and the optical fiber 45 group are mounted so as to intersect each other.
[0029]
Next, the collective sensor head plate 59 is cut along the dividing line 60 with a cutter. This cutting is performed precisely because it also serves to finish the end face of the optical fiber that appears on the cut surface. If a plurality of collective sensor head plates 59 that are stacked and fixed are cut, they can be cut efficiently.
[0030]
In the rectangular parallelepiped pieces obtained by cutting the collective sensor head plate 59 along the dividing line 60, 1, 2, 3,. . . When the odd-numbered ones are turned upside down, and the rectangular parallelepipeds are shifted to the left and right as shown in FIG. 7, the parts divided by the vertical dividing lines 61 are the same, 1 This corresponds to one sensor head. Therefore, each rectangular parallelepiped of FIG. 7 becomes the collective sensor head 57 used in the collective substrate process of FIG. Thus, the collective sensor head plate 59 as shown in FIG. 6 is made and divided, whereby the collective sensor head 57 can be efficiently manufactured. 6B is defined as a parallel line group passing through the intersection of the optical fiber groups as viewed from the front as described above and a parallel line group in the middle thereof, the corresponding parallel lines are defined as the division line 60. Although it can be drawn in the vertical direction perpendicular to, it is obvious which one should be taken.
[0031]
The collective sensor head block 62 of FIG. 8 further advances the idea of the collective sensor head plate 59 of FIG. This is a resin block in which optical fibers 44 and 45 are inserted in such a manner that multiple sensor head plates 59 are stacked and integrated. 8A is a top view and FIG. 8B is a front view. As shown in FIG. 8A, the optical fiber 44 group and the 45 group intersect to form a pair. If this collective sensor head block 62 is cut along the dividing line 60 and further cut along the dividing line 63, a large number of collective sensor heads 57 used in the process of FIG. 4 are obtained.
[0032]
When the collective sensor head block 62 of FIG. 8 is used, the sensor head collective parts used in the collective substrate process of FIG. 4 are not divided by the dividing line 63 of FIG. What is necessary is just to use the plate-shaped thing only divided | segmented by the line 60 upside down like the case of the collective sensor head board 59 of the above-mentioned FIG. Although this is also plate-shaped, it is different from the collective sensor head plate 59 of FIG. 6 and spreads in a direction orthogonal thereto. The collective sensor heads 57 group depicted in FIG. 4 are separate and separated by a groove along the dividing line 53a. However, when a plate-like member as described above is used, the collective sensor head is connected and has no groove. The head plate is bonded onto the collective light shielding plate 55, and when the assembly is diced, the sensor head layer is also cut in the direction along the dividing line 53a.
[0033]
According to the collective sensor head block 62 of FIG. 8, a collective part including a large number of sensor heads can be obtained by one molding, but at the same time, a molding die or a container becomes complicated, and it is troublesome to attach an optical fiber thereto. In general, this method is not always advantageous. Whether to use the collective sensor head plate 59 of FIG. 6 or the collective sensor head block 62 of FIG. 8 should be determined according to the actual situation.
[0034]
As mentioned above, although the circuit component completed as a reflection type optical sensor was demonstrated, the circuit component which makes a reflection type optical sensor a part of structure also exists. For example, there is a circuit component called an optical microphone, which is configured to include a reflective optical sensor and a vibrating membrane that is an object to be detected arranged near the sensor head. It is converted and processed. The reflection type optical sensor and the manufacturing method thereof according to the present invention extends to a part including a reflection type optical sensor as a part of the configuration, such as an optical microphone.
[0035]
【The invention's effect】
As described above, since the reflection type optical sensor obtained by the present invention forms an optical path with an optical fiber, the light utilization efficiency is improved and a high-performance optical sensor is obtained. Moreover, it is simple in structure and suitable for miniaturization and thinning. Also, for manufacturing, it proceeds with manufacturing using collective parts such as collective boards, and finally cuts and divides to obtain a large number of products at once. Productivity is high and manufacturing costs can be reduced.
As described above, according to the present invention, it is possible to inexpensively provide a reflective optical sensor that is ultra-compact, high-performance, highly reliable, and suitable for surface mounting.
[Brief description of the drawings]
FIG. 1 is a perspective view of a reflective optical sensor of the present invention, in which (A) is a perspective view, (B) is a front view, and (C) is a top view.
FIG. 2 is a perspective view perspectively showing another reflective optical sensor of the present invention.
FIG. 3 is a perspective view showing still another reflective optical sensor of the present invention in a perspective manner.
FIG. 4 is a perspective view showing a manufacturing method of the reflective photosensor of the present invention.
FIG. 5 is a perspective view of a collective light shielding frame used for manufacturing the reflection type photosensor of the present invention.
6A and 6B show a collective sensor head plate used for manufacturing the reflective optical sensor of the present invention, in which FIG. 6A is a top view and FIG. 6B is a front view.
7 is a collective sensor head obtained by dividing the collective sensor head plate of FIG.
FIGS. 8A and 8B show a collective sensor head block used for manufacturing the reflective optical sensor of the present invention, in which FIG. 8A is a top view and FIG. 8B is a front view.
FIG. 9 is a principle configuration diagram of a reflective photosensor.
10A and 10B show a conventional reflective optical sensor, in which FIG. 10A is a perspective view and FIG. 10B is a cross-sectional view taken along line BB in FIG.
11A and 11B show another conventional reflective optical sensor, in which FIG. 11A is a perspective view and FIG. 11B is a cross-sectional view taken along the line BB of FIG.
FIG. 12 is a drawing of still another conventional reflective optical sensor.
[Explanation of symbols]
2 Light emitting element
3 Light receiving element
8 windows
9 Board
10, 46 Shading frame
11 Sealing resin
12 Conductive part
14, 47 Light-shielding film
15 Conductive pattern
16 terminal electrode
21, 42 Sensor head
25, 26, 44, 45 Optical fiber
41 Shading plate
43 resin
51 Assembly board
52 Through hole
55 Collective shading plate
57 Collective sensor head
58 collective shading frame
59 Collective sensor head plate
62 Collective sensor head block

Claims

A light-emitting element, a light-receiving element, and a light-shielding plate that separates both optical elements are mounted on a circuit board, and both the optical elements are sealed in a sealing resin. It is a structure in which sensor heads embedded through the upper and lower surfaces are laminated,
The end surfaces of the two optical fibers are close to each other on the surface of the sensor head, and are separated from each other at the joint surface with the sealing resin on the opposite side to face the light emitting element and the light receiving element, respectively. projection of both axes of the two parallel plane directions including each have without a certain angle, and the distances between the two planes in the manufacturing method of the reflection-type optical sensor Ru der than the sum of the radii of the two optical fibers There,
A light-emitting element group and a light-receiving element group are mounted on a collective substrate that includes a large number of product areas in a matrix, and a light-shielding plate portion that collectively separates the light-emitting elements and the light-receiving elements in the same product area. Adhering onto the assembly substrate, filling the light-transmitting element group and the light-receiving element group by filling a light-transmitting sealing resin on the collective substrate at substantially the same height as the collective light-shielding plate, and sealing the collective light-shielding plate and the sealing resin On top, the required number of sensor heads including a plurality of sensor heads in which two optical fibers are encapsulated in resin per reflective optical sensor are adhered, and the resulting assembly is cut vertically and horizontally. In the manufacturing method of the reflective optical sensor that takes a large number of
The collective sensor head includes a plurality of sensor heads connected in a line, and includes two optical fiber groups each having a length that is many times the completed dimension, and the axis of each optical fiber group is included in the same plane. The two planes including the axes of the two optical fiber groups are parallel to each other, and the distance between the two planes is equal to or greater than the sum of the radii of the optical fibers belonging to the two optical fiber groups. The projections of the two optical fiber groups in the direction are supported in a mold or a container so that they intersect at a constant angle, filled with resin, solidified into a plate, and parallel lines passing through the intersection of the optical fibers in the projection, A method of manufacturing a reflective optical sensor, comprising: cutting along a parallel line group passing through the middle of the parallel line group.

In the manufacturing method of the reflection type photosensor according to claim 1,
In the collective sensor head, a plurality of sensor heads are connected in a matrix form vertically and horizontally instead of in a single row as described above. The axes of each optical fiber group are included in the same plane and are parallel to each other at a constant interval, the two planes including the axes of both optical fiber groups are parallel to each other, and the distance between both planes belongs to each of the two optical fiber groups It is equal to or greater than the sum of the radii of the optical fibers, and supports that the projections of both optical fiber groups in the two plane directions intersect at a constant angle in parallel with a plurality of the two optical fiber groups at a predetermined interval. Are arranged side by side and supported in a mold or container, filled with resin, solidified into a block, and parallel plane groups passing through the intersections of the optical fibers in the projection and the plane. Method for producing a reflective optical sensor, characterized in that obtained by cutting along a plane parallel group through the group of planes intermediate.