JP2004235261A

JP2004235261A - Optical system device and its manufacturing method

Info

Publication number: JP2004235261A
Application number: JP2003019478A
Authority: JP
Inventors: Hiroyuki Yoshida; 浩之吉田; Mikio Masui; 幹生桝井
Original assignee: Matsushita Electric Works Ltd
Current assignee: Panasonic Electric Works Co Ltd
Priority date: 2003-01-28
Filing date: 2003-01-28
Publication date: 2004-08-19

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical system device having high-efficiency optical characteristics and highly reliable durability, and to provide a method of manufacturing the device by which sealing of an optical element with a protective resin and formation of a high-accuracy lens can be realized. <P>SOLUTION: The optical system device 10 is manufactured by respectively forming a resin substrate 1, a first sealing layer 3, and a second sealing layer 4 of a resin having a low modulus of elasticity of ≤10 GPa, a resin having a modulus of elasticity of 1 Pa to 1 MPa and a glass transition temperature of 213-233 K, and an ultraviolet-curing resin having a modulus of elasticity of 1-2.5 GPa and a glass transition temperature of ≥413 K and sealing an optical element 2 by forming a lens section 5 of a resin having a modulus of elasticity of ≥3 GPa. Since the resins having different moduli of elasticity are used appropriately and the stress of the encapsulating resin is relieved comprehensively, such highly reliable durability can be realized that no vacuum void occurs in the resins and no peeling occurs in the interfaces of the resins even when the temperature and environment change. In addition, the high-efficiency optical characteristics can be realized by mounting the element 2 on the bottom face of a metallized recessed section and, at the same time, by encapsulating the element 2 in a reliably durable state and constituting a lens structure. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、光コネクタ等を構成する光学系装置の製造方法であって、特に光学素子の封止、及びレンズ形成に関する。
【０００２】
【従来の技術】
従来から、光学系装置において基板実装された発光や受光を行う光学素子を透明樹脂にて封入・封止して光学素子の保護及びレンズ形成等の光学要素形成が行われている。このような光学系装置として、図１１（ａ）（ｂ）に示すように、立体回路成形品１００上に、発光素子１０１や受光素子１０２のような光学素子１０１，１０２を実装する共に、この光学素子の実装面とは異なる面（図では下面）に形成した凹部１０３に前記光学素子１０１，１０２の信号処理を行う集積回路素子１０４を実装し、前記光学素子１０１，１０２と前記信号処理用集積回路素子とを接続する回路を、前記光学素子の実装部位から信号処理集積回路素子の実装部位に至るように前記立体回路成形品の表面に金属めっき膜による回路パターン１０５〜１０８を構成し、前記光学素子の受光面若しくは発光面に対向するレンズ１０９と、前記回路パターンの保護層１１０と、信号処理用集積回路素子の実装部位の封止樹脂層１１１を２次成形の樹脂により形成したものが知られている（例えば、特許文献１参照）。
【０００３】
また、他の封止成形例として、図１２（ａ）（ｂ）に示すように、受光素子２３３と発光素子２３４を一体的にモールドしたものが知られている（例えば、特許文献２参照）。図１２（ａ）に示すいわゆる光結合装置（フォトカプラ）は、個別のリードフレーム２３１と２３２に、それぞれ搭載された発光素子２３３と受光素子２３４とを対向して配置し、それら素子２３３、２３４を透光性樹脂（半透明エポキシ樹脂）２３５で１次モールドして光結合パスを形成し、この後、外装めっきを施し、さらに外乱光の遮光のために遮光性樹脂（黒色エポキシ樹脂）２３６で２次モールドした、いわゆる２層モールドタイプのものである。その発光素子２３３には、応力緩和のためにシリコン樹脂２３７によるプリコートが施されたものである。また、図１２（ｂ）に示す光結合装置は、１層モールドタイプであって、リードフレーム２３１と２３２に搭載した発光素子２３３と受光素子２３４とを、互いに対向した位置関係となるようにプリコート樹脂（透明シリコン樹脂）２４７で結合した後、それら全体を遮光性樹脂２４６でモールドすることによって形成されている。
【０００４】
また、上記例とは別に、図１３（ａ）（ｂ）に示すような光結合装置の製造方法が知られている（例えば、特許文献３参照）。リードフレーム３１１に搭載された発光素子３１４と受光素子３１５を覆うように光透過可能な透明ゲル樹脂３１８を両素子の上方から滴下するポッティング方法により塗布し、かつ透明ゲル樹脂３１８の外周部を覆うように光反射樹脂３１９をモールド成形する。前記透明ゲル樹脂３１８は、針入度が４５〜６５（ＪＩＳ−Ｋ２２２０）の樹脂を用いている。光反射樹脂３１９と透明ゲル樹脂３１８との間に熱応力が生じた場合でも、透明ゲル樹脂自体が弾性変形して応力緩和するため、透明ゲル樹脂と光反射樹脂との界面の広い範囲にわたって剥離が生じることはなく、また、透明ゲル樹脂３１８の易変形性により熱応力が緩和されるため、光反射樹脂３１９におけるクラックの発生が防止される。
【０００５】
また、光学系装置と同様の封止技術が用いられる半導体チップの封止構造について、図１４に示すようなものが知られている（例えば、特許文献４参照）。その封止構造は、基板４００のチップ搭載部にダイボンド材４０１で半導体チップ４０２を接着し、その半導体チップ４０２側と前記基板４００側とをボンデイングワイヤ４０３を介して電気的に接続した半導体チップの封止構造において、半導体チップ４０２及びダイボンド材４０１の界面をシリコーン系のシーリング材４０４で封止すると共に、そのシーリング材４０４の高さを前記ボンデイングワイヤ４０３のループの位置よりも低くなるようにしたものである。この封止方法は、半導体チップ４０２及び半導体チップ４０２とボンデイングワイヤ４０３の接合部を封止して電気回路の保護をすると共に、ボンディングワイヤ４０３は完全に被覆せずに残すことにより封止工程における応力によるボンディングワイヤ４０３の断線や短絡の回避を図るものである。長いボンディングワイヤ４０３や多数のボンディングワイヤ４０３を密接して用いる場合に有効とされている。
【０００６】
【特許文献１】
特開２００２−１６４６０４号公報
【特許文献２】
特開平５−３２７００５号公報
【特許文献３】
特開平１１−２３３８１０号公報
【特許文献４】
特開平８−２０４０４８号公報
【０００７】
【発明が解決しようとする課題】
しかしながら、従来の上述したような光学素子や半導体チップの封入・封止の方法においては、シリコーン系などの保護コート剤が用いられており、これらの保護コート剤は吸水・透湿性が高く光学素子や電極の腐食が生じ易く耐久性に問題があった。また、封止樹脂の応力による光学素子の破損を防止するために、低弾性率の応力緩和樹脂を保護コート剤（ＪＣＲ：ＪｕｎｃｔｉｏｎＣｏａｔｉｎｇＲｅｓｉｎ）として用いて光学素子をプリコート又はシーリングすることが知られているが、このような低弾性率の保護コート剤を立体回路基板（ＭｏｌｄｅｄＩｎｔｅｒｃｏｎｎｅｃｔＤｅｖｉｓｅ；ＭＩＤ基板）に適用して光学素子にプリコートした場合、立体回路基板の外周に透明樹脂によりレンズを形成する工程において、熱膨張した状態となった保護コート剤が常温に戻るときに収縮することにより、樹脂中の真空ボイドや樹脂界面の剥離が生じるため光損失が大きくなるという問題がある。
【０００８】
本発明は、上記課題を解消するものであって、光学素子保護のための透明樹脂封止と高精度レンズ形成において、高効率な光特性と耐久信頼性の向上を実現できる光学系装置及びその製造方法を提供することを目的とする。
【０００９】
【課題を解決するための手段及び発明の効果】
上記課題を達成するために、請求項１の発明は、樹脂基板の開口した凹部に光学素子を実装した光学系装置であって、前記樹脂基板は１０ＧＰａ以下の低弾性率樹脂からなり、前記樹脂基板の開口した凹部の表面は光反射機能と電気回路機能を持たせるためにメタライズされており、前記メタライズされた凹部の底面に実装した光学素子は弾性率が１Ｐａ以上１ＭＰａ以下かつガラス転移温度が２１３Ｋ以上２３３Ｋ以下の樹脂からなる第１の封止層により封止され、第１の封止層の上には１ＧＰａ以上２．５ＧＰａ以下かつガラス転移温度が４１３Ｋ以上の紫外光硬化性樹脂からなる第２の封止層が形成され、第２の封止層の上には弾性率が３ＧＰａ以上の樹脂からなるレンズ部が形成されているものである。
【００１０】
上記構成においては、樹脂基板を１０ＧＰａ以下の低弾性率樹脂で形成し、第１の封止層を弾性率が１Ｐａ以上１ＭＰａ以下かつガラス転移温度が２１３Ｋ以上２３３Ｋ以下の樹脂で形成し、第２の封止層を弾性率が１ＧＰａ以上２．５ＧＰａ以下かつガラス転移温度が４１３Ｋ以上の紫外光硬化性樹脂で形成し、レンズ部を弾性率が３ＧＰａ以上の樹脂で形成し、これらをこの順序で積層するので、光学系装置を構成する樹脂の弾性率が適切に選択して用いられ、総合的に封止樹脂の応力が緩和されるため、温度環境の変化に対して光学装置の耐久信頼性が得られる。封止樹脂相互間の応力緩和と、界面接合力との相乗効果によって、光学系装置が置かれる−４０℃〜８５℃という温度環境において、樹脂中の真空ボイドや樹脂界面の剥離を生じることのない耐久信頼性の向上した光学系装置が得られる。
【００１１】
例えば、２３３Ｋ（−４０℃）×５分、３５８Ｋ（８５℃）×５分を１サイクルとして熱衝撃試験を行ったところ７００サイクルまで全品良品であった。上記の弾性率及びガラス転移温度の条件以外においては、例えば、第１の封止層の弾性率が１Ｐａ以下又はガラス転移温度が２１３Ｋ以下の場合、熱衝撃試験の結果、第１の封止層の樹脂内部に真空ボイドが発生し光路障害となる。また、第１の封止層の弾性率が１ＭＰａ以上又はガラス転移温度が２３３Ｋ以上の場合、熱衝撃試験の結果、第１の封止層と樹脂基板凹部のメタライズ面との間で界面剥離が発生し、光路障害となる。また、第２の封止層の弾性率が１ＧＰａ以下又はガラス転移温度が４１３Ｋ以下の場合、熱衝撃試験の結果、第２の封止層の樹脂内部に真空ボイドが発生し光路障害となる。また、第２の封止層の弾性率が２．５ＧＰａ以上の場合、熱衝撃試験の結果、第２の封止層と樹脂基板凹部のメタライズ面との間で界面剥離が発生し、光路障害となる。また、レンズ部の樹脂の弾性率が３ＧＰａ以下の場合、熱衝撃試験の結果、第２の封止層とレンズ部の樹脂との間で界面剥離が発生し、光路障害となる。
【００１２】
また、上記構成においては、メタライズした凹部の底面に光学素子を実装すると共に、上記のように信頼性の安定した封止及びレンズ構造を実現しているので、高効率な光特性が実現される。
【００１３】
請求項２の発明は、樹脂基板の開口した凹部に光学素子を実装した光学系装置であって、前記樹脂基板は１０ＧＰａ以下の低弾性率樹脂からなり、前記樹脂基板の開口した凹部の表面は光反射機能と電気回路機能を持たせるためにメタライズされており、前記メタライズされた凹部の底面に実装した光学素子は弾性率が２．５ＧＰａ以上３．５ＧＰａ以下かつガラス転移温度が４１３Ｋ以上の樹脂からなる封止層により封止され、前記封止層の上には弾性率が３ＧＰａ以上の樹脂からなるレンズ部が形成されているものである。
【００１４】
上記構成においては、樹脂基板を１０ＧＰａ以下の低弾性率樹脂で形成し、封止樹脂を弾性率が２．５ＧＰａ以上３．５ＧＰａ以下かつガラス転移温度が４１３Ｋ以上の樹脂で形成し、レンズ部を弾性率が３ＧＰａ以上の樹脂で形成し、これらをこの順序で積層するので、光学系装置を構成する樹脂の弾性率が適切に選択して用いられ、総合的に封止樹脂の応力が緩和されるため、温度環境の変化に対して光学装置の耐久信頼性が得られる。封止樹脂相互間の応力緩和と、界面接合力との相乗効果によって、光学系装置が置かれる−４０℃〜８５℃という温度環境において、樹脂中の真空ボイドや樹脂界面の剥離を生じることのない耐久信頼性の向上した光学系装置が得られる。
【００１５】
例えば、２３３Ｋ（−４０℃）×５分、３５８Ｋ（８５℃）×５分を１サイクルとして熱衝撃試験を行ったところ５００サイクルまで全品良品であった。上記の弾性率及びガラス転移温度の条件以外においては、例えば、封止層の弾性率が２．５ＧＰａ以下又はガラス転移温度が４１３Ｋ以下の場合、熱衝撃試験の結果、樹脂内部に真空ボイドが発生し光路障害となる。また、封止層の弾性率が３．５ＧＰａ以上の場合、熱衝撃試験の結果、封止層と樹脂基板凹部のメタライズ面との間で界面剥離が発生し、光路障害となる。また、レンズ部の樹脂の弾性率が３ＧＰａ以下の場合、熱衝撃試験の結果、封止層とレンズ部の樹脂との間で界面剥離が発生し、光路障害となる。
【００１６】
また、上記構成においては、メタライズした凹部の底面に光学素子を実装すると共に、上記のように信頼性の安定した封止及びレンズ構造を実現しているので、高効率な光特性が実現される。
【００１７】
請求項３の発明は、請求項１又は請求項２記載の光学系装置において、凹部のメタライズ面が粗面化されているものである。
【００１８】
上記構成においては、光学素子を実装する凹部のメタライズ面が粗面化されているので、メタライズ面に入射する光が拡散して迷光が減少する効果が得られると共に、その粗面に樹脂が食い込むアンカー効果によって、凹部に充填する封止樹脂の界面接合力が向上する。
【００１９】
請求項４の発明は、請求項１乃至請求項３のいずれか記載の光学系装置において、前記メタライズされた凹部の底面に基板樹脂が露出した部位を形成するものである。
【００２０】
上記構成においては、メタライズされた凹部の底面に基板樹脂が露出した部位を形成しているので、凹部に充填する封止樹脂と基板樹脂とが前記露出した部位で樹脂同士が接合するため、メタライズ面を介しての接着よりも強固な封止樹脂の接合力が得られる。
【００２１】
請求項５の発明は、請求項４記載の光学系装置において、前記メタライズされた凹部底面に基板樹脂が露出した溝を形成し、該溝に封止樹脂を注入するものである。
【００２２】
上記構成においては、凹部底面に基板樹脂が露出した溝を形成し、該溝に封止樹脂を注入するので、前記同様の効果に加え、封止樹脂と基板樹脂との接合面積が増加してさらに強固な封止樹脂の接合力が得られる。
【００２３】
請求項６の発明は、請求項１又は請求項２記載の光学系装置において、前記開口した凹部は樹脂基板より突出した鏡筒の先端に設けられており、前記レンズ部を形成する樹脂が前記突出した鏡筒の外側表面を覆っているものである。
【００２４】
上記構成においては、レンズ部を形成する樹脂が突出した鏡筒の外側表面を覆っているので、レンズ部形成樹脂と基板樹脂との接合部界面の面積が広く取られるため、界面を通して封止部内部への吸湿が低減され、光学素子の劣化を防止できる。また、強固に形成されたレンズ部樹脂により内部の封止樹脂を包み込んでいるため、封止樹脂とレンズ樹脂との剥離が防止できる。
【００２５】
請求項７の発明は、樹脂基板の開口した凹部に光学素子を実装した光学系装置の製造方法であって、１０ＧＰａ以下の低弾性率樹脂からなる樹脂基板の開口した凹部が反射機能と電気回路機能を持たせるためにメタライズされており、メタライズされた凹部底面に光学素子を実装する実装工程と、弾性率が１Ｐａ以上１ＭＰａ以下かつガラス転移温度が２１３Ｋ以上２３３Ｋ以下の樹脂で第１の封止層を形成して前記光学素子を封止する第１封止工程と、弾性率が１ＧＰａ以上２．５ＧＰａ以下かつガラス転移温度が４１３Ｋ以上のＵＶ硬化性樹脂で第２の封止層を形成して前記第１の封止層を封止する第２封止工程と、前記封止した樹脂層上に弾性率が３ＧＰａ以上の樹脂からなるレンズ部を形成するレンズ形成工程と、を有するものである。
【００２６】
上記製造方法においては、樹脂基板を１０ＧＰａ以下の低弾性率樹脂で形成する工程と、第１の封止層を弾性率が１Ｐａ以上１ＭＰａ以下かつガラス転移温度が２１３Ｋ以上２３３Ｋ以下の樹脂で形成する工程と、第２の封止層を弾性率が１ＧＰａ以上２．５ＧＰａ以下かつガラス転移温度が４１３Ｋ以上の紫外光硬化性樹脂で形成する工程と、レンズ部を弾性率が３ＧＰａ以上の樹脂で形成する工程とにより、樹脂の弾性率を適切に選択して光学系装置を製造するので、総合的に封止樹脂の応力が緩和した光学系装置が得られ、また、温度環境の変化に対して光学装置の耐久信頼性が得られる。
【００２７】
例えば、２３３Ｋ（−４０℃）×５分、３５８Ｋ（８５℃）×５分を１サイクルとして熱衝撃試験を行ったところ７００サイクルまで全品良品であった。上記の弾性率及びガラス転移温度の条件以外においては、例えば、第１の封止層の弾性率が１Ｐａ以下又はガラス転移温度が２１３Ｋ以下の場合、熱衝撃試験の結果、第１の封止層の樹脂内部に真空ボイドが発生し光路障害となる。また、第１の封止層の弾性率が１ＭＰａ以上又はガラス転移温度が２３３Ｋ以上の場合、熱衝撃試験の結果、第１の封止層と樹脂基板凹部のメタライズ面との間で界面剥離が発生し、光路障害となる。また、第２の封止層の弾性率が１ＧＰａ以下又はガラス転移温度が４１３Ｋ以下の場合、熱衝撃試験の結果、第２の封止層の樹脂内部に真空ボイドが発生し光路障害となる。また、第２の封止層の弾性率が２．５ＧＰａ以上の場合、熱衝撃試験の結果、第２の封止層と樹脂基板凹部のメタライズ面との間で界面剥離が発生し、光路障害となる。また、レンズ部の樹脂の弾性率が３ＧＰａ以下の場合、熱衝撃試験の結果、第２の封止層とレンズ部の樹脂との間で界面剥離が発生し、光路障害となる。
【００２８】
また、上記製造方法においては、メタライズした凹部の底面に光学素子を実装する工程と共に、上記のように信頼性の安定した封止及びレンズ構造を実現する工程によるので、高効率な光特性が実現される。
【００２９】
請求項８の発明は、請求項７記載の光学系装置の製造方法において、前記第１封止工程と前記第２封止工程は、第１の封止層の樹脂を滴下し、該樹脂上面に該樹脂よりも比重の小さい第２の封止層の樹脂を滴下し、その後、これらの樹脂を硬化させるものである。
【００３０】
上記製造方法においては、第１の封止層の樹脂を滴下し、該樹脂上面に該樹脂よりも比重の小さい第２の封止層の樹脂を滴下し、その後、これら２つの樹脂を硬化させるので、２つの封止樹脂の境界面が液状で形成されているため相溶化しており、２つの封止樹脂を硬化処理するとき樹脂の界面で化学結合して接合力が向上する。また、下層の樹脂よりも比重の小さい樹脂を上層に用いるので、樹脂同士の混合が防止される。
【００３１】
請求項９の発明は、樹脂基板の開口した凹部に光学素子を実装した光学系装置の製造方法であって、１０ＧＰａ以下の低弾性率樹脂からなる樹脂基板の開口した凹部が反射機能と電気回路機能を持たせるためにメタライズされており、メタライズされた凹部底面に光学素子を実装する工程と、弾性率が２．５ＧＰａ以上３．５ＧＰａ以下かつガラス転移温度が４１３Ｋ以上の樹脂で封止層を形成して前記光学素子を封止する封止工程と、前記封止層上に弾性率が３ＧＰａ以上の樹脂からなるレンズ部を形成するレンズ形成工程とを有するものである。
【００３２】
上記製造方法においては、樹脂基板を１０ＧＰａ以下の低弾性率樹脂で形成する工程と、封止樹脂を弾性率が２．５ＧＰａ以上３．５ＧＰａ以下かつガラス転移温度が４１３Ｋ以上の樹脂で形成する工程と、レンズ部を弾性率が３ＧＰａ以上の樹脂で形成する工程とにより、樹脂の弾性率を適切に選択して光学系装置を製造するので、総合的に封止樹脂の応力が緩和した光学系装置が得られ、また、温度環境の変化に対して光学装置の耐久信頼性が得られる。
【００３３】
例えば、２３３Ｋ（−４０℃）×５分、３５８Ｋ（８５℃）×５分を１サイクルとして熱衝撃試験を行ったところ５００サイクルまで全品良品であった。上記の弾性率及びガラス転移温度の条件以外においては、例えば、封止層の弾性率が２．５ＧＰａ以下又はガラス転移温度が４１３Ｋ以下の場合、熱衝撃試験の結果、樹脂内部に真空ボイドが発生し光路障害となる。また、封止層の弾性率が３．５ＧＰａ以上の場合、熱衝撃試験の結果、封止層と樹脂基板凹部のメタライズ面との間で界面剥離が発生し、光路障害となる。また、レンズ部の樹脂の弾性率が３ＧＰａ以下の場合、熱衝撃試験の結果、封止層とレンズ部の樹脂との間で界面剥離が発生し、光路障害となる。
【００３４】
また、上記製造方法においては、メタライズした凹部の底面に光学素子を実装する工程と共に、上記のように信頼性の安定した封止及びレンズ構造を実現する工程によるので、高効率な光特性が実現される。
【００３５】
請求項１０の発明は、請求項９記載の光学系装置の製造方法において、前記封止工程における封止樹脂の滴下の後、該樹脂の架橋度が５０〜８０％の状態で前記レンズ部形成用樹脂を注入してこれらの樹脂を硬化させるものである。
【００３６】
上記製造方法においては、封止樹脂の架橋度が５０〜８０％の状態でレンズ部形成用樹脂を注入してこれらの樹脂を硬化させるので、レンズ部形成用樹脂の硬化剤によりレンズ部下層の封止樹脂の硬化が進むと共に、レンズ部樹脂と封止樹脂との化学結合も形成されるため、レンズ部と封止樹脂との接合力が向上する。
【００３７】
請求項１１の発明は、請求項１０記載の光学系装置の製造方法において、前記封止樹脂の架橋度を樹脂硬化時の加熱時間によって制御するものである。
【００３８】
上記製造方法においては、請求項１０におけると同様の効果に加え、加熱時間を変化させることにより、既存の硬化装置を用いて、架橋度を容易に制御及び変化させて製造することができる。
【００３９】
請求項１２の発明は、請求項７又は請求項９記載の光学系装置の製造方法において、前記レンズ形成工程の直前の封止工程に用いる封止樹脂を紫外光硬化樹脂とし、粗面化された表面を有する紫外光透過材料で形成された透明部材の粗面を前記封止樹脂に接着させ、該透明部材を介して該封止樹脂に紫外光を照射して封止樹脂を硬化させ、前記透明部材の粗面形状を前記封止樹脂表面に転写させるものである。
【００４０】
上記製造方法においては、レンズ形成工程の直前の封止工程に用いる封止樹脂を紫外光硬化樹脂とし、粗面化された表面を有する紫外光透過材料で形成された透明部材の粗面を前記封止樹脂に接着させて封止樹脂を硬化させるので、封止樹脂表面に転写して形成された粗面構造により、レンズ部と封止樹脂との接合力が向上する。
【００４１】
請求項１３の発明は、請求項７又は請求項９記載の光学系装置の製造方法において、前記レンズ形成工程においてレンズ部を形成する樹脂を硬化させた後、常温冷却よりも遅い冷却速度で硬化温度から常温まで冷却するものである。
【００４２】
上記製造方法においては、レンズ部を形成する樹脂を硬化させた後、常温冷却よりも遅い冷却速度で硬化温度から常温まで冷却するので、冷却時間を制御して熱応力の緩和を行いながら冷却できるため、急激な収縮による樹脂界面の剥離や樹脂へのクラック発生を防止できる。
【００４３】
【発明の実施の形態】
以下、本発明の一実施形態に係る光学系装置及びその製造方法について、図面を参照して説明する。図１は、本発明の一実施形態の光学系装置１０を示している。この光学系装置１０は、立体回路成形品である樹脂基板（ＭＩＤ基板）１の開口した凹部１３に光学素子（発光素子）２を実装及び封入してレンズ５を形成しており、光コネクタ等の発光デバイスとして用いられるものである。
【００４４】
この光学系装置１０の各部の構成を説明する。樹脂基板１は、弾性率が１０ＧＰａ以下の材料物性を有する低弾性率樹脂からなり、基部１１と基部１１から突出した円柱状の鏡筒部１２から構成されている。基部１１は、直方体形状をしており、その下面には、凹部９１が設けられ、その凹部９１には光学素子２の信号処理を行う集積回路素子９２が実装及び封止されている。この集積回路素子９２と光学素子２とは図示しない回路パターンにより接続されている。これらの基部１１部分は従来例（例えば、前出の図１１参照）と同じであり以下において特に説明はしない。
【００４５】
鏡筒部１２の先端には、図２に示されるように、開口した凹部１３があり、凹部１３の表面は、光の反射機能と電気回路機能を持たせるためにメタライズが施されたメタライズ面１４となっている。メタライズされた凹部底面には光学素子２が実装され、光学素子２の裏面電極が凹部底面のメタライズ面を介して電極１４ａに、また、光学素子２の上面電極からは金属細線２１により電極１４ｂにそれぞれ電気的に接続されている。ここで、電極１４ａと電極１４ｂは互いに電気絶縁されている。光学素子２は上下面電極に電圧が印加されることにより発光する発光素子である。
【００４６】
この実装された光学素子２の封止構造について、図１に戻って説明する。まず光学素子２及び金属細線２１が、弾性率が１Ｐａ以上、１ＭＰａ以下で、ガラス転移温度が２１３Ｋ以上２３３Ｋ以下の樹脂により形成した第１の封止層３により封止されている。第１の封止層３の樹脂としては、変性アクリレート樹脂の他、例えば、エポキシ樹脂などを用いてもよい。次に、第１の封止層３の樹脂層上に、弾性率が１ＧＰａ以上、２．５ＧＰａ以下で、ガラス転移温度が４１３Ｋ以上である紫外線（ＵＶ）硬化性樹脂により形成した第２の封止層４によりさらに封止されている。第２の封止層４の紫外線硬化性樹脂としては、エポキシ樹脂の他、例えば、変性アクリレート樹脂などを用いてもよい。そして、第２の封止層４の樹脂層上に、弾性率が３ＧＰａ以上の樹脂からなるレンズ部５が形成されている。レンズ部５の樹脂としては、エポキシ樹脂の他、例えば、変性アクリレート樹脂などを用いてもよい。
【００４７】
光学系装置１０の製造工程を説明する。図３は各工程毎の断面図、図４は各工程のフローを示す。まず、図３（ａ）に示すように、表面がメタライズされた開口部１３を有する基板（基板の鏡筒部１２のみ図示）を製作する（Ｓ１１）。次に、図３（ｂ）に示すように、光学素子２を、例えば導電性樹脂によりメタライズされた凹部底面１５にダイボンディングして光学素子２の裏面を電極１４ａに接続し、表面電極を金属細線２１により電極１４ｂに接続して実装する（Ｓ１２）。次に、図３（ｃ）に示すように、凹部に封止樹脂（第１層）３を充填して第１の封止工程を行う（Ｓ１３）。次に、図３（ｄ）に示すように、凹部の残空間にＵＶ硬化性樹脂（第２層）４を充填して第２の封止工程を行う（Ｓ１４）。次に、図３（ｅ）に示すように、封止樹脂上にレンズ部５を形成する（Ｓ１５）。このレンズ部５を形成する方式として、例えば、トランスファ成形方式を用いることにより、レンズ部５の形状と面精度を高精度に成形することができる。
【００４８】
上述した工程により製造した多層構造の封止部を有する光学系装置について熱衝撃試験を行った。試験品は、第１層についてもＵＶ硬化性樹脂を用いている。また、比較例として、光学素子の封止からレンズ部形成までをレンズ部の樹脂のみで構成した単一構造の光学系装置も製造して同じ熱衝撃試験を行った。使用した樹脂の物性および硬化条件を表１に示す。
【００４９】
【表１】

【００５０】
熱衝撃試験は液相にて実施し、２３３Ｋ（−４０℃）×５分、３５８Ｋ（８５℃）×５分を１サイクルとした。熱衝撃試験の結果、本発明に係る多層構造の光学系装置は、７００サイクルまでは全品良品であったが、レンズ部樹脂による単一構造の比較例のものは、レンズ形成樹脂と光学素子との境界面で剥離が生じ、全て不良であった。
【００５１】
上述のように、光学系装置１０を構成する樹脂の弾性率を適切に選択して用いることにより、総合的に封止樹脂の応力が緩和され、また、界面接合力との相乗効果によって、光学系装置が置かれる−４０℃〜８５℃という温度環境において、樹脂中の真空ボイドや樹脂界面の剥離を生じることのない耐久信頼性の向上した光学系装置が得られた。
【００５２】
また、上述の製造工程において、第１層目の封止樹脂を光学素子を覆う程度に少量滴下し硬化させた後、第２層目の封止樹脂を滴下して硬化させた。これにより、第１層目樹脂の高線膨張率に起因する体積変化の影響が抑制され、さらに追加して行った熱衝撃試験において、樹脂中の真空ボイドや樹脂界面の剥離による不良率を抑える効果が確認された。
【００５３】
次に、本発明の一実施形態に係る光学系装置及びその製造方法の他の例について説明する。図５は封止樹脂が一層である光学系装置２０を示し、図６はその製造方法を示すフローである。光学系装置２０は、前出の光学系装置１０において封止樹脂層が２層から１層になったものである。
【００５４】
光学系装置２０の製造工程を説明する。表面がメタライズされた開口部１３を有する樹脂基板１を、弾性率が１０ＧＰａ以下の低弾性率樹脂からなる樹脂を用いて製作する（Ｓ２１）。次に、光学素子２を、例えば導電性樹脂によりメタライズされた凹部底面にダイボンディングして光学素子２の裏面を電気回路接続し、表面電極を金属細線２１により電気回路接続して実装する（Ｓ２２）。次に、弾性率が２．５ＧＰａ以上、３．５ＧＰａ以下で、ガラス転移温度が４１３Ｋ以上の封止樹脂による封止層６を凹部に充填して封止部を形成する封止工程を行う（Ｓ２３）。封止樹脂としては、エポキシ樹脂の他、例えば、変性アクリレート樹脂などを用いてもよい。次に、封止樹脂上に弾性率が３ＧＰａ以上の樹脂からなるレンズ部５を形成する（Ｓ２４）。レンズ部５の樹脂としては、エポキシ樹脂の他、例えば、変性アクリレート樹脂などを用いてもよい。このレンズ部５を形成する方式として、例えば、トランスファ成形方式を用いることにより、レンズ部５の形状と面精度を高精度に成形することができる。
【００５５】
上述した工程により製造した多層構造の封止部を有する光学系装置について熱衝撃試験を行った。比較例として、光学素子の封止からレンズ部形成までをレンズ部の樹脂のみで構成した単一構造の光学系装置も製造して同じ熱衝撃試験を行った。使用した樹脂の物性および硬化条件を表２に示す。
【００５６】
【表２】

【００５７】
熱衝撃試験は液相にて実施し、２３３Ｋ（−４０℃）×５分、３５８Ｋ（８５℃）×５分を１サイクルとした。熱衝撃試験の結果、本発明に係る多層構造の光学系装置は、５００サイクルまでは全品良品であったが、レンズ部樹脂による単一構造の比較例のものは、レンズ形成樹脂と光学素子との境界面で剥離が生じ、全て不良であった。
【００５８】
上述のように、封止樹脂１層とレンズ部との２層構造による光学系装置２０においても、光学素子の上部空間に充填する樹脂の弾性率を適切に選択して用いることにより、総合的に封止樹脂の応力が緩和され、また、界面接合力との相乗効果によって、光学系装置が置かれる−４０℃〜８５℃という温度環境において、樹脂中の真空ボイドや樹脂界面の剥離を生じることのない耐久信頼性の向上した光学系装置が得られた。
【００５９】
さらに他の製造方法の例を示す。樹脂層を多層化する場合、下層の樹脂を滴下し、その上面に下層の樹脂よりも比重の小さい上層の掛脂を滴下した後、これらの樹脂を硬化させるようにしてもよい。このような方法によると、２つの封止樹脂の境界面が液状で形成されているため相溶化しており、２つの封止樹脂を硬化処理するとき樹脂の界面で化学結合して接合力が向上する。また、下層の樹脂よりも比重の小さい樹脂を上層に用いるので、樹脂同士の混合が防止される。
【００６０】
熱衝撃試験のために、表１に示した樹脂を用いて１層目（下層）の樹脂を滴下した後、１層目の樹脂を硬化せず、１層目よりも比重の小さい２層目（上層）の樹脂を滴下し、２層目の樹脂を滴下した後、６Ｊ／ｃｍ２の条件でＵＶ照射し、１層目と２層目の樹脂を硬化させた光学系装置を作製した。この方法によって作製した光学系装置と、通常の方法で作製した光学系装置について、熱衝撃試験を行った。その結果、１０００サイクル後に、通常方法で作製したサンプルは１層目と２層目の界面が剥離して不良となったのに対し、本方法によって作製したサンプルは１層目と２層日の界面で剥離せず、全品良品であった。
【００６１】
さらに他の例として、光学素子を実装する凹部のメタライズ面を粗面化して封止樹脂を充填してもよい。この方法によると、メタライズ面に入射する光が粗面により拡散して迷光が減少する効果が得られると共に、その粗面に樹脂が食い込むアンカー効果によって、凹部に充填する封止樹脂の界面接合力が向上する効果がある。
【００６２】
熱衝撃試験のために、表１に示した樹脂を用い、メタライズ面の面粗度Ｒｙを１μｍ以上として光学系装置を作製した。この光学系装置の場合、１０００サイクルの熱衝撃試験後において全て良品であったが、比較例として面粗度Ｒｙを１μｍ未満としたものではメタライズ面と樹脂との剥離による不良品が発生した。また、本方法による光学系装置では、メタライズ面での拡散による迷光の減少によって、光学特性における損失を、通常の場合よりも５％減少できた。
【００６３】
さらに他の例として、図７（ａ）（ｂ）に示すように、メタライズされた凹部の底面に基板樹脂が露出した部位、例えば三日月状の基板樹脂露出部１６を形成してもよい。この構成においては、凹部に充填する封止樹脂と基板樹脂とが前記露出した部位で樹脂同士が接合するため、メタライズ面を介しての接着よりも強固な封止樹脂の接合力が得られる。例えば、表１に示した樹脂を用い、図７に示される構造の光学系装置を作製したものは、熱衝撃試験１０００サイクル後において全て良品であったが、底面が全面メタライズされたものは剥離により不良となった。
【００６４】
上記構造に加え、図８（ａ）（ｂ）に示すように、メタライズされた凹部底面に基板樹脂が露出した溝７を形成してもよい。この構成においては、溝７に封止樹脂を注入するので、前記同様の効果に加え、封止樹脂と基板樹脂との接合面積が増加してさらに強固な封止樹脂の接合力が得られる。例えば、表１に示した樹脂を用い、図７に示される構造の光学系装置を作製したものは、熱衝撃試験１５００サイクル後全て良品であったが、溝のない前記の露出部のものは剥離により不良となった。
【００６５】
さらに他の例として、封止樹脂の架橋度が５０〜８０％の状態でレンズ部形成用樹脂を注入してこれらの樹脂を硬化させてもよい。このような方法による、レンズ部形成用樹脂の硬化剤によりレンズ部下層の封止樹脂の硬化が進むと共に、レンズ部樹脂と封止樹脂との化学結合も形成されるため、レンズ部と封止樹脂との接合力が向上する。また、封止樹脂の架橋度の制御を樹脂硬化時の加熱時間によって行ってもよい。加熱時間を変化させることにより、架橋度を容易に制御及び変化させて製造することができる。
【００６６】
熱衝撃試験のために、例えば、表２に示した樹脂を用い、封止樹脂を恒温槽にて４０８℃×３０分加熱することによって７０％架橋させ、その上にレンズ部を形成した光学系装置を作製した。この光学系装置について熱衝撃試験したところ、１０００サイクル後において不良は発生しなかった。比較例として、４０８℃×２時間加熱して前記よりも架橋反応を進めて８５％の架橋とし、その上にレンズ部を形成したものは１０００サイクルの熱衝撃試験において封止樹脂とレンズ部樹脂の界面に剥離が生じて不良となった。また、４０８℃×１５分加熱し４５％架橋したものにレンズ部を樹脂成形するものは、樹脂成形時の圧力により封止樹脂が流される成形不良となった。
【００６７】
さらに他の例を図９に示す。図９（ａ）に示すように、レンズ形成工程の直前の封止工程に用いる封止樹脂６を紫外光硬化樹脂として樹脂基板１の開口した凹部に光学素子２を封止するため充填する。次に、粗面化された表面を有する紫外光透過材料で形成された透明部材７の粗面を前記封止樹脂６に接着させて配置する。この状態で透明部材７を透過して封止樹脂６に紫外光を照射することによって封止樹脂６を硬化させる。このような方法によると、図９（ｂ）に示されるように、硬化した封止樹脂６の表面には透明部材の表面から転写された粗面構造６１が形成される。この粗面構造６１を有する封止樹脂の上に、図９（ｃ）に示されるようにレンズ部５を樹脂成形する。この結果、レンズ部樹脂５と封止樹脂６との接合力が向上する。
【００６８】
上述した工程により製造した光学系装置について熱衝撃試験を行った。まず、封止樹脂を滴下後、紫外光透過材で形成された面粗度Ｒｙが１．５μｍの平板を封止樹脂に密着させ、この平板を介して封止樹脂に紫外光を照射し硬化させた。これにより、封止樹脂表面の面粗度Ｒｙが１．５μｍのものが得られた。粗面化された封止樹脂の上にレンズ部を成形した。レンズ部成形後のサンプルを熱衝撃試験したところ、１０００サイクルにおいて不良は発生しなかった。使用した樹脂の物性および硬化条件を表３に示す。
【００６９】
【表３】

【００７０】
さらに他の例を図１０（ａ）（ｂ）に示す。光学素子２を実装する開口凹部は、樹脂基板１の突出部からなる鏡筒１２の先端に設けられている。光学素子２を実装した後、封止樹脂３，４又は封止樹脂６を充填硬化させた後、突出した鏡筒１２の外側表面を覆う樹脂５１を有する形状でレンズ部５が成形される。このような光学系装置４０，５０は、レンズ部５を形成する樹脂が突出した鏡筒１２の外側表面を覆っているので、レンズ部形成樹脂と基板樹脂との接合部界面の面積を広く取ることができる。そのため、界面を通して封止部内部への吸湿が低減され、光学素子の劣化を防止できる。また、強固に形成されたレンズ部樹脂によって内部の封止樹脂を包み込んでいるため、封止樹脂とレンズ樹脂との剥離の防止ができる。
【００７１】
上述した光学系装置について熱衝撃試験を行った。使用した材料は表１のものと同じである。トランスファー成形により鏡筒外側にレンズ部樹脂を成形して、図９（ａ）に示す光学系装置４０を作製した。この光学系装置について、１０００サイクルの熱衝撃試験を行ったところ、レンズ部樹脂と基板樹脂間の剥離は発生しなかった。比較例として、鏡筒上部のみレンズ部を成形した光学系装置について１０００サイクルの熱衝撃試験を実施したところ、レンズ部樹脂と基板樹脂間の界面剥離が発生して不良となった。
【００７２】
さらに他の例として、レンズ形成工程においてレンズ部を形成する樹脂を硬化させた後、常温冷却よりも遅い冷却速度で硬化温度から常温まで冷却するようにしてもよい。このような方法においては、冷却時間を制御して熱応力の緩和を行いながら冷却できるため、急激な収縮による樹脂界面の剥離や樹脂へのクラック発生を防止できる。例えば、表１に示した樹脂を用い、レンズ部を樹脂成形して４２３Ｋで硬化させた後、光学系装置のサンプルを成形金型から取り出しで恒温槽に投入し１分間に１Ｋずつ３００Ｋまで冷却した。このサンプルに対し熱衝撃試験を行ったところ、１０００サイクル後において不良は発生しなかった。
【００７３】
なお、本発明は、上記構成に限られることなく種々の変形が可能である。例えば、封止樹脂を積層、又は封止樹脂にレンズ部樹脂を積層する場合、下層の樹脂を形成した後、例えば大気圧プラズマ装置を用いて、樹脂表面の清浄化／活性化を行い、各樹脂層間の濡れ性／界面接合力を向上させる処理を行ってもよい。
【図面の簡単な説明】
【図１】本発明の一実施形態に係る光学系装置の断面図。
【図２】同上装置の光学素子実装部の斜視図。
【図３】（ａ）〜（ｅ）は同上装置の製造工程を説明する断面図。
【図４】同上装置の製造方法の工程フロー図。
【図５】本発明の一実施形態に係る光学系装置の他の例を示す断面図。
【図６】同上装置の製造方法の工程フロー図。
【図７】（ａ）は本発明の一実施形態に係る光学系装置のさらに他の例を示す平面図、（ｂ）は同装置の断面図。
【図８】（ａ）は本発明の一実施形態に係る光学系装置のさらに他の例を示す平面図、（ｂ）は同装置の断面図。
【図９】（ａ）は本発明の一実施形態に係る光学系装置の製造方法を説明する断面図、（ｂ）は同装置の部分断面図、（ｃ）は同装置の断面図。
【図１０】（ａ）（ｂ）は本発明の一実施形態に係る光学系装置のさらに他の例を示す断面図。
【図１１】（ａ）（ｂ）は従来の光学系装置の断面図。
【図１２】（ａ）（ｂ）は従来の他の光学系装置の断面図。
【図１３】（ａ）（ｂ）は従来のさらに他の光学系装置の断面図。
【図１４】従来の半導体チップの封止構造を説明する断面図。
【符号の説明】
１樹脂基板
２光学素子
３封止層
４封止層
５レンズ部
６封止層
１３凹部
１４メタライズ面
１０，２０，３０，４０、５０光学系装置[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for manufacturing an optical system device constituting an optical connector or the like, and particularly relates to sealing of an optical element and formation of a lens.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, optical elements mounted on a substrate in an optical system device for emitting and receiving light are sealed and sealed with a transparent resin to protect the optical elements and to form optical elements such as forming lenses. As such an optical system device, as shown in FIGS. 11A and 11B,

optical elements

101 and 102 such as a light emitting element 101 and a light receiving element 102 are mounted on a three-dimensional circuit molded product 100. An integrated circuit element 104 for performing signal processing of the

optical elements

101 and 102 is mounted in a concave portion 103 formed on a surface (a lower surface in the figure) different from a mounting surface of the optical element, and the

optical elements

101 and 102 and the signal processing The circuit connecting the integrated circuit element, the circuit pattern 105-108 by a metal plating film on the surface of the three-dimensional circuit molded product so as to reach from the mounting part of the optical element to the mounting part of the signal processing integrated circuit element, A lens 109 facing a light receiving surface or a light emitting surface of the optical element, a protective layer 110 of the circuit pattern, and a sealing resin layer 111 at a mounting position of the signal processing integrated circuit element. Those formed by the secondary molding resin is known (for example, see Patent Document 1).
[0003]
Further, as another example of sealing molding, as shown in FIGS. 12A and 12B, a molding in which a light receiving element 233 and a light emitting element 234 are integrally molded is known (for example, see Patent Document 2). . In the so-called optical coupling device (photocoupler) shown in FIG. 12A, a light emitting element 233 and a light receiving element 234 respectively mounted on

individual lead frames

231 and 232 are arranged to face each other. Is first molded with a light-transmitting resin (semi-transparent epoxy resin) 235 to form an optical coupling path, and thereafter, plating is applied to the exterior, and further, a light-shielding resin (black epoxy resin) 236 is used to shield disturbance light. , A so-called two-layer mold type. The light emitting element 233 is pre-coated with a silicon resin 237 for stress relaxation. The optical coupling device shown in FIG. 12 (b) is a single-layer mold type, in which the light emitting element 233 and the light receiving element 234 mounted on the

lead frames

231 and 232 are pre-coated so as to have a positional relationship facing each other. After being bonded with a resin (transparent silicon resin) 247, they are entirely formed by molding with a light-shielding resin 246.
[0004]
In addition to the above example, a method for manufacturing an optical coupling device as shown in FIGS. 13A and 13B is known (for example, see Patent Document 3). A transparent gel resin 318 capable of transmitting light is applied by a potting method of dripping from above both elements so as to cover the light emitting element 314 and the light receiving element 315 mounted on the lead frame 311, and covers the outer periphery of the transparent gel resin 318. The light reflecting resin 319 is molded as described above. As the transparent gel resin 318, a resin having a penetration of 45 to 65 (JIS-K2220) is used. Even when a thermal stress is generated between the light reflecting resin 319 and the transparent gel resin 318, the transparent gel resin itself is elastically deformed and the stress is relaxed, so that the transparent gel resin peels over a wide range of the interface between the transparent gel resin and the light reflecting resin. Does not occur, and thermal stress is reduced by the easy deformation of the transparent gel resin 318, so that cracks in the light reflection resin 319 are prevented.
[0005]
Further, as a sealing structure of a semiconductor chip using the same sealing technology as that of the optical system device, a structure as shown in FIG. 14 is known (for example, see Patent Document 4). The sealing structure is such that a semiconductor chip 402 is bonded to a chip mounting portion of a substrate 400 with a die bonding material 401, and the semiconductor chip 402 side and the substrate 400 side are electrically connected via bonding wires 403. In the sealing structure, the interface between the semiconductor chip 402 and the die bond material 401 is sealed with a silicone-based sealing material 404, and the height of the sealing material 404 is set to be lower than the position of the loop of the bonding wire 403. Things. This sealing method seals the semiconductor chip 402 and the bonding portion between the semiconductor chip 402 and the bonding wire 403 to protect the electric circuit, and also leaves the bonding wire 403 without completely covering it, so that the sealing process can be performed. This is to avoid disconnection or short circuit of the bonding wire 403 due to stress. This is effective when a long bonding wire 403 or a large number of bonding wires 403 are used closely.
[0006]
[Patent Document 1]
JP-A-2002-164604
[Patent Document 2]
JP-A-5-327005
[Patent Document 3]
JP-A-11-233810
[Patent Document 4]
JP-A-8-204048
[0007]
[Problems to be solved by the invention]
However, in the conventional methods for encapsulating and encapsulating optical elements and semiconductor chips as described above, silicone-based protective coating agents are used, and these protective coating agents have high water absorption and moisture permeability, and thus have high optical element performance. And the corrosion of the electrode was apt to occur, and there was a problem in durability. Further, in order to prevent the optical element from being damaged by the stress of the sealing resin, it is known that the optical element is pre-coated or sealed using a low-modulus stress relaxation resin as a protective coating agent (JCR: Junction Coating Resin). However, when a protective coating agent having such a low elastic modulus is applied to a three-dimensional circuit board (Molded Interconnect Device; MID substrate) to precoat an optical element, a lens is formed of a transparent resin around the three-dimensional circuit board. In the process, the protective coating agent which has been in a thermally expanded state contracts when returning to normal temperature, which causes a problem that a vacuum void in the resin or a separation of the resin interface occurs, resulting in a large light loss.
[0008]
The present invention has been made to solve the above problems, and an optical system device capable of realizing highly efficient optical characteristics and improved durability durability in transparent resin encapsulation for protecting an optical element and forming a high-precision lens. It is intended to provide a manufacturing method.
[0009]
Means for Solving the Problems and Effects of the Invention
In order to achieve the above object, an invention according to claim 1 is an optical system device in which an optical element is mounted in an open concave portion of a resin substrate, wherein the resin substrate is made of a resin having a low elastic modulus of 10 GPa or less. The surface of the concave portion opened in the substrate is metallized to have a light reflecting function and an electric circuit function, and the optical element mounted on the bottom surface of the metalized concave portion has an elastic modulus of 1 Pa to 1 MPa and a glass transition temperature of 1 Pa or less. Sealed by a first sealing layer made of a resin of 213K or more and 233K or less, and made of an ultraviolet curable resin having a glass transition temperature of 413K or more and 1 GPa or more and 2.5 GPa on the first sealing layer. A second sealing layer is formed, and a lens portion made of a resin having an elastic modulus of 3 GPa or more is formed on the second sealing layer.
[0010]
In the above configuration, the resin substrate is formed of a resin having a low elastic modulus of 10 GPa or less, and the first sealing layer is formed of a resin having an elastic modulus of 1 Pa or more and 1 MPa or less and a glass transition temperature of 213 K or more and 233 K or less. Is formed of an ultraviolet curable resin having an elastic modulus of 1 GPa or more and 2.5 GPa or less and a glass transition temperature of 413 K or more, and a lens portion is formed of a resin having an elastic modulus of 3 GPa or more. Because of the lamination, the elastic modulus of the resin that composes the optical system device is appropriately selected and used, and the stress of the sealing resin is relaxed comprehensively, so the durability of the optical device with respect to changes in temperature environment Is obtained. Due to the synergistic effect between the stress relaxation between the sealing resins and the interface bonding force, in a temperature environment of −40 ° C. to 85 ° C. where the optical device is placed, vacuum voids in the resin and peeling of the resin interface may occur. An optical system device with improved durability and reliability can be obtained.
[0011]
For example, when a thermal shock test was performed using 233K (−40 ° C.) × 5 minutes and 358K (85 ° C.) × 5 minutes as one cycle, all the products were good up to 700 cycles. Other than the above conditions of the elastic modulus and the glass transition temperature, for example, when the elastic modulus of the first sealing layer is 1 Pa or less or the glass transition temperature is 213 K or less, as a result of the thermal shock test, the first sealing layer A vacuum void is generated inside the resin, causing an optical path obstruction. In addition, when the elastic modulus of the first sealing layer is 1 MPa or more or the glass transition temperature is 233 K or more, as a result of the thermal shock test, interfacial peeling between the first sealing layer and the metallized surface of the resin substrate concave portion occurs. Occurs, causing optical path obstruction. In addition, when the elastic modulus of the second sealing layer is 1 GPa or less or the glass transition temperature is 413 K or less, as a result of the thermal shock test, a vacuum void is generated inside the resin of the second sealing layer, causing an optical path obstruction. When the elastic modulus of the second sealing layer is 2.5 GPa or more, as a result of the thermal shock test, interface separation occurs between the second sealing layer and the metallized surface of the concave portion of the resin substrate, and optical path obstruction occurs. It becomes. In addition, when the elastic modulus of the resin of the lens unit is 3 GPa or less, interface peeling occurs between the second sealing layer and the resin of the lens unit as a result of the thermal shock test, causing an optical path obstruction.
[0012]
Further, in the above configuration, the optical element is mounted on the bottom surface of the metallized concave portion, and the highly reliable sealing and lens structure are realized as described above, so that highly efficient optical characteristics are realized. .
[0013]
The invention according to claim 2 is an optical device in which an optical element is mounted in an opened concave portion of the resin substrate, wherein the resin substrate is made of a low elastic modulus resin of 10 GPa or less, and the surface of the opened concave portion of the resin substrate is The optical element mounted on the bottom surface of the metallized recess has a modulus of elasticity of 2.5 GPa or more and 3.5 GPa or less and a glass transition temperature of 413 K or more. And a lens portion made of a resin having an elastic modulus of 3 GPa or more is formed on the sealing layer.
[0014]
In the above configuration, the resin substrate is formed of a resin having a low elastic modulus of 10 GPa or less, the sealing resin is formed of a resin having an elastic modulus of 2.5 GPa or more and 3.5 GPa or less, and a glass transition temperature of 413 K or more. Since the resin is formed of a resin having an elastic modulus of 3 GPa or more and laminated in this order, the elastic modulus of the resin constituting the optical system device is appropriately selected and used, and the stress of the sealing resin is alleviated comprehensively. Therefore, durability reliability of the optical device with respect to changes in the temperature environment can be obtained. Due to the synergistic effect between the stress relaxation between the sealing resins and the interface bonding force, in a temperature environment of −40 ° C. to 85 ° C. where the optical device is placed, vacuum voids in the resin and peeling of the resin interface may occur. An optical system device with improved durability and reliability can be obtained.
[0015]
For example, when a thermal shock test was performed with 233K (−40 ° C.) × 5 minutes and 358K (85 ° C.) × 5 minutes as one cycle, all the products were good up to 500 cycles. Except for the above conditions of the elastic modulus and the glass transition temperature, for example, when the elastic modulus of the sealing layer is 2.5 GPa or less or the glass transition temperature is 413 K or less, as a result of the thermal shock test, a vacuum void is generated inside the resin. The optical path is obstructed. When the elastic modulus of the sealing layer is 3.5 GPa or more, as a result of the thermal shock test, interface peeling occurs between the sealing layer and the metallized surface of the concave portion of the resin substrate, causing an optical path obstruction. When the elastic modulus of the resin of the lens portion is 3 GPa or less, interface peeling occurs between the sealing layer and the resin of the lens portion as a result of the thermal shock test, causing an optical path obstruction.
[0016]
Further, in the above configuration, the optical element is mounted on the bottom surface of the metallized concave portion, and the highly reliable sealing and lens structure are realized as described above, so that highly efficient optical characteristics are realized. .
[0017]
According to a third aspect of the present invention, in the optical device according to the first or second aspect, the metallized surface of the concave portion is roughened.
[0018]
In the above configuration, since the metallized surface of the concave portion for mounting the optical element is roughened, the effect of diffusing light incident on the metallized surface and reducing stray light is obtained, and the resin penetrates the rough surface. Due to the anchor effect, the interfacial bonding force of the sealing resin filling the concave portion is improved.
[0019]
According to a fourth aspect of the present invention, in the optical device according to any one of the first to third aspects, a portion where the substrate resin is exposed is formed on a bottom surface of the metallized concave portion.
[0020]
In the above configuration, since the portion where the substrate resin is exposed is formed on the bottom surface of the metallized concave portion, the sealing resin filling the concave portion and the substrate resin are bonded to each other at the exposed portion, so that the metallized portion is formed. A stronger bonding force of the sealing resin can be obtained than by bonding through the surface.
[0021]
According to a fifth aspect of the present invention, in the optical device according to the fourth aspect, a groove in which the substrate resin is exposed is formed on the bottom surface of the metallized concave portion, and a sealing resin is injected into the groove.
[0022]
In the above configuration, since the groove in which the substrate resin is exposed is formed on the bottom surface of the concave portion and the sealing resin is injected into the groove, the bonding area between the sealing resin and the substrate resin is increased in addition to the same effect as described above. Furthermore, a strong sealing resin bonding force can be obtained.
[0023]
According to a sixth aspect of the present invention, in the optical device according to the first or second aspect, the opened concave portion is provided at a tip of a lens barrel protruding from a resin substrate, and the resin forming the lens portion is It covers the outer surface of the protruding lens barrel.
[0024]
In the above configuration, since the resin forming the lens portion covers the outer surface of the protruding lens barrel, the area of the interface between the lens portion forming resin and the substrate resin is large, so that the sealing portion is formed through the interface. Moisture absorption into the inside is reduced, and deterioration of the optical element can be prevented. In addition, since the sealing resin inside is wrapped by the lens portion resin which is firmly formed, peeling of the sealing resin and the lens resin can be prevented.
[0025]
The invention according to claim 7 is a method of manufacturing an optical system device in which an optical element is mounted in an opened concave portion of a resin substrate, wherein the opened concave portion of the resin substrate made of a low elastic modulus resin of 10 GPa or less has a reflection function and an electric circuit. A mounting step of mounting an optical element on the bottom surface of the metalized concave portion, and a first encapsulation with a resin having an elastic modulus of 1 Pa or more and 1 MPa or less and a glass transition temperature of 213 K or more and 233 K or less. A first sealing step of forming a layer and sealing the optical element, and forming a second sealing layer with a UV-curable resin having an elastic modulus of 1 GPa or more and 2.5 GPa or less and a glass transition temperature of 413 K or more. A second sealing step of sealing the first sealing layer, and a lens forming step of forming a lens portion made of a resin having an elastic modulus of 3 GPa or more on the sealed resin layer. Ah .
[0026]
In the above manufacturing method, a step of forming the resin substrate with a low elastic modulus resin of 10 GPa or less, and forming the first sealing layer with a resin having an elastic modulus of 1 Pa or more and 1 MPa or less and a glass transition temperature of 213 K or more and 233 K or less. A step of forming the second sealing layer with an ultraviolet curable resin having an elastic modulus of 1 GPa or more and 2.5 GPa or less and a glass transition temperature of 413 K or more, and forming a lens portion with a resin having an elastic modulus of 3 GPa or more. The optical device is manufactured by appropriately selecting the modulus of elasticity of the resin by the step of performing, so that an optical device in which the stress of the sealing resin is relaxed comprehensively is obtained. Durability reliability of the optical device can be obtained.
[0027]
For example, when a thermal shock test was performed using 233K (−40 ° C.) × 5 minutes and 358K (85 ° C.) × 5 minutes as one cycle, all the products were good up to 700 cycles. Other than the above conditions of the elastic modulus and the glass transition temperature, for example, when the elastic modulus of the first sealing layer is 1 Pa or less or the glass transition temperature is 213 K or less, as a result of the thermal shock test, the first sealing layer A vacuum void is generated inside the resin, causing an optical path obstruction. In addition, when the elastic modulus of the first sealing layer is 1 MPa or more or the glass transition temperature is 233 K or more, as a result of the thermal shock test, interfacial peeling between the first sealing layer and the metallized surface of the resin substrate concave portion occurs. Occurs, causing optical path obstruction. In addition, when the elastic modulus of the second sealing layer is 1 GPa or less or the glass transition temperature is 413 K or less, as a result of the thermal shock test, a vacuum void is generated inside the resin of the second sealing layer, causing an optical path obstruction. When the elastic modulus of the second sealing layer is 2.5 GPa or more, as a result of the thermal shock test, interface separation occurs between the second sealing layer and the metallized surface of the concave portion of the resin substrate, and optical path obstruction occurs. It becomes. In addition, when the elastic modulus of the resin of the lens unit is 3 GPa or less, interface peeling occurs between the second sealing layer and the resin of the lens unit as a result of the thermal shock test, causing an optical path obstruction.
[0028]
In addition, in the above-described manufacturing method, a high-efficiency optical characteristic is realized because the step of mounting the optical element on the bottom surface of the metallized concave portion and the step of realizing the reliable and stable sealing and lens structure as described above are realized. Is done.
[0029]
According to an eighth aspect of the present invention, in the method for manufacturing an optical system device according to the seventh aspect, in the first sealing step and the second sealing step, a resin of a first sealing layer is dropped, and Then, the resin of the second sealing layer having a lower specific gravity than the resin is dropped, and then these resins are cured.
[0030]
In the above manufacturing method, the resin of the first sealing layer is dropped, the resin of the second sealing layer having a lower specific gravity than the resin is dropped on the upper surface of the resin, and then the two resins are cured. Therefore, since the boundary surface between the two sealing resins is formed in a liquid state, they are compatible with each other, and when the two sealing resins are cured, a chemical bond is formed at the interface between the resins, thereby improving the bonding strength. Further, since a resin having a specific gravity smaller than that of the resin in the lower layer is used for the upper layer, mixing of the resins is prevented.
[0031]
The invention according to claim 9 is a method of manufacturing an optical system device in which an optical element is mounted in an opened concave portion of a resin substrate, wherein the opened concave portion of the resin substrate made of a low elastic modulus resin of 10 GPa or less has a reflection function and an electric circuit. A step of mounting the optical element on the bottom surface of the metallized concave portion and a resin having an elastic modulus of 2.5 GPa or more and 3.5 GPa or less and a glass transition temperature of 413 K or more. A sealing step of forming and sealing the optical element; and a lens forming step of forming a lens portion made of a resin having an elastic modulus of 3 GPa or more on the sealing layer.
[0032]
In the above manufacturing method, a step of forming the resin substrate with a resin having a low elastic modulus of 10 GPa or less and a step of forming a sealing resin with a resin having an elastic modulus of 2.5 GPa or more and 3.5 GPa or less and a glass transition temperature of 413 K or more. And the step of forming the lens portion with a resin having an elastic modulus of 3 GPa or more, the optical system device is manufactured by appropriately selecting the elastic modulus of the resin. The device can be obtained, and the durability of the optical device can be obtained with respect to changes in the temperature environment.
[0033]
For example, when a thermal shock test was performed with 233K (−40 ° C.) × 5 minutes and 358K (85 ° C.) × 5 minutes as one cycle, all the products were good up to 500 cycles. Except for the above conditions of the elastic modulus and the glass transition temperature, for example, when the elastic modulus of the sealing layer is 2.5 GPa or less or the glass transition temperature is 413 K or less, as a result of the thermal shock test, a vacuum void is generated inside the resin. The optical path is obstructed. When the elastic modulus of the sealing layer is 3.5 GPa or more, as a result of the thermal shock test, interface peeling occurs between the sealing layer and the metallized surface of the concave portion of the resin substrate, causing an optical path obstruction. When the elastic modulus of the resin of the lens portion is 3 GPa or less, interface peeling occurs between the sealing layer and the resin of the lens portion as a result of the thermal shock test, causing an optical path obstruction.
[0034]
In addition, in the above-described manufacturing method, a high-efficiency optical characteristic is realized because the step of mounting the optical element on the bottom surface of the metallized concave portion and the step of realizing the reliable and stable sealing and lens structure as described above are realized. Is done.
[0035]
According to a tenth aspect of the present invention, in the method for manufacturing an optical device according to the ninth aspect, after the sealing resin is dropped in the sealing step, the lens portion is formed in a state where the degree of crosslinking of the resin is 50 to 80%. These resins are injected to cure these resins.
[0036]
In the above manufacturing method, the resin for forming the lens portion is injected and cured in a state where the degree of crosslinking of the sealing resin is 50 to 80%. As the curing of the sealing resin progresses, a chemical bond between the lens portion resin and the sealing resin is formed, so that the bonding strength between the lens portion and the sealing resin is improved.
[0037]
According to an eleventh aspect of the present invention, in the method for manufacturing an optical system device according to the tenth aspect, the degree of crosslinking of the sealing resin is controlled by a heating time during curing of the resin.
[0038]
In the above manufacturing method, in addition to the same effects as in the tenth aspect, by changing the heating time, it is possible to easily control and change the degree of cross-linking by using an existing curing device, and manufacture.
[0039]
According to a twelfth aspect of the present invention, in the method for manufacturing an optical device according to the seventh or ninth aspect, the sealing resin used in the sealing step immediately before the lens forming step is made of an ultraviolet curable resin, and the surface is roughened. A rough surface of a transparent member formed of an ultraviolet light transmitting material having a bent surface is adhered to the sealing resin, and the sealing resin is cured by irradiating the sealing resin with ultraviolet light through the transparent member, The rough surface shape of the transparent member is transferred to the sealing resin surface.
[0040]
In the above manufacturing method, the sealing resin used in the sealing step immediately before the lens forming step is an ultraviolet light curable resin, and the rough surface of the transparent member formed of an ultraviolet light transmitting material having a roughened surface is used. Since the sealing resin is cured by adhering to the sealing resin, the bonding strength between the lens portion and the sealing resin is improved by the rough surface structure formed by being transferred to the sealing resin surface.
[0041]
According to a thirteenth aspect of the present invention, in the method for manufacturing an optical device according to the seventh or ninth aspect, after the resin forming the lens portion is cured in the lens forming step, the resin is cured at a cooling rate slower than room temperature cooling. It cools from temperature to room temperature.
[0042]
In the above manufacturing method, after the resin forming the lens portion is cured, the resin is cooled from the curing temperature to room temperature at a cooling rate slower than room temperature cooling, so that cooling can be performed while controlling the cooling time and relaxing thermal stress. Therefore, peeling of the resin interface due to rapid shrinkage and generation of cracks in the resin can be prevented.
[0043]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an optical system device and a method of manufacturing the same according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows an optical device 10 according to an embodiment of the present invention. This optical system device 10 has a lens 5 formed by mounting and enclosing an optical element (light emitting element) 2 in an open concave portion 13 of a resin substrate (MID substrate) 1 which is a three-dimensional circuit molded product. Is used as a light emitting device.
[0044]
The configuration of each unit of the optical system device 10 will be described. The resin substrate 1 is made of a low elastic modulus resin having a material property of an elastic modulus of 10 GPa or less, and includes a base 11 and a cylindrical lens barrel 12 protruding from the base 11. The base 11 has a rectangular parallelepiped shape, and a concave portion 91 is provided on the lower surface thereof. An integrated circuit element 92 for performing signal processing of the optical element 2 is mounted and sealed in the concave portion 91. The integrated circuit element 92 and the optical element 2 are connected by a circuit pattern (not shown). These base portions 11 are the same as in the conventional example (for example, see FIG. 11 described above), and will not be particularly described below.
[0045]
As shown in FIG. 2, at the tip of the lens barrel portion 12, there is an open concave portion 13, and the surface of the concave portion 13 has a metallized surface provided with a metallized surface so as to have a light reflecting function and an electric circuit function. It is 14. The optical element 2 is mounted on the bottom surface of the metallized concave portion, and the back electrode of the optical element 2 is connected to the electrode 14a via the metallized surface of the concave bottom surface, and from the upper electrode of the optical element 2 to the electrode 14b by the thin metal wire 21. Each is electrically connected. Here, the electrode 14a and the electrode 14b are electrically insulated from each other. The optical element 2 is a light emitting element that emits light when a voltage is applied to the upper and lower electrodes.
[0046]
Returning to FIG. 1, the sealing structure of the mounted optical element 2 will be described. First, the optical element 2 and the thin metal wire 21 are sealed by a first sealing layer 3 formed of a resin having an elastic modulus of 1 Pa or more and 1 MPa or less and a glass transition temperature of 213 K or more and 233 K or less. As the resin of the first sealing layer 3, for example, an epoxy resin may be used in addition to the modified acrylate resin. Next, a second sealing layer formed of an ultraviolet (UV) curable resin having an elastic modulus of 1 GPa or more and 2.5 GPa or less and a glass transition temperature of 413 K or more on the resin layer of the first sealing layer 3. It is further sealed by the stop layer 4. As the ultraviolet curable resin of the second sealing layer 4, for example, a modified acrylate resin or the like may be used in addition to the epoxy resin. Then, on the resin layer of the second sealing layer 4, a lens portion 5 made of a resin having an elastic modulus of 3 GPa or more is formed. As the resin of the lens portion 5, for example, a modified acrylate resin or the like may be used in addition to the epoxy resin.
[0047]
The manufacturing process of the optical device 10 will be described. FIG. 3 is a sectional view of each step, and FIG. 4 shows a flow of each step. First, as shown in FIG. 3A, a substrate (only the lens barrel 12 of the substrate is shown) having an opening 13 whose surface is metallized is manufactured (S11). Next, as shown in FIG. 3B, the optical element 2 is die-bonded to a concave bottom surface 15 metallized with, for example, a conductive resin, and the back surface of the optical element 2 is connected to the electrode 14a. The thin film 21 is connected to and mounted on the electrode 14b (S12). Next, as shown in FIG. 3C, the recess is filled with a sealing resin (first layer) 3 to perform a first sealing step (S13). Next, as shown in FIG. 3D, the remaining space of the concave portion is filled with a UV curable resin (second layer) 4 to perform a second sealing step (S14). Next, as shown in FIG. 3E, the lens unit 5 is formed on the sealing resin (S15). As a method of forming the lens portion 5, for example, by using a transfer molding method, the shape and surface accuracy of the lens portion 5 can be molded with high accuracy.
[0048]
A thermal shock test was performed on an optical system device having a sealing portion having a multilayer structure manufactured by the above-described process. The test article also uses a UV-curable resin for the first layer. In addition, as a comparative example, an optical system device having a single structure in which the process from sealing the optical element to forming the lens portion was formed only of the resin of the lens portion was also manufactured and subjected to the same thermal shock test. Table 1 shows the physical properties and curing conditions of the resin used.
[0049]
[Table 1]

[0050]
The thermal shock test was carried out in the liquid phase, and one cycle was performed at 233 K (−40 ° C.) × 5 minutes and at 358 K (85 ° C.) × 5 minutes. As a result of the thermal shock test, the optical device having a multilayer structure according to the present invention was all good products up to 700 cycles. Peeling occurred at the boundary surface of, and all were defective.
[0051]
As described above, by appropriately selecting and using the elastic modulus of the resin constituting the optical system device 10, the stress of the sealing resin is reduced as a whole, and the synergistic effect with the interfacial bonding force allows the optical effect to be increased. In a temperature environment of −40 ° C. to 85 ° C. where the system device is placed, an optical system device with improved durability and reliability without causing vacuum voids in the resin or peeling of the resin interface was obtained.
[0052]
In the above-described manufacturing process, the sealing resin of the first layer was dropped and hardened so as to cover the optical element, and then the sealing resin of the second layer was dropped and cured. This suppresses the effect of volume change caused by a high coefficient of linear expansion of the first layer resin, and further suppresses a defective rate due to vacuum voids in the resin and peeling of the resin interface in an additional thermal shock test. The effect was confirmed.
[0053]
Next, another example of the optical device according to the embodiment of the present invention and a method of manufacturing the same will be described. FIG. 5 shows an optical system device 20 having a single layer of sealing resin, and FIG. 6 is a flow chart showing a manufacturing method thereof. The optical device 20 is obtained by changing the sealing resin layer from two to one in the optical device 10 described above.
[0054]
The manufacturing process of the optical system device 20 will be described. The resin substrate 1 having the opening 13 whose surface is metallized is manufactured using a resin made of a low elastic modulus resin having an elastic modulus of 10 GPa or less (S21). Next, the optical element 2 is die-bonded to the bottom of the concave portion metallized with, for example, a conductive resin, the back surface of the optical element 2 is connected to an electric circuit, and the front electrode is connected to the electric circuit by a thin metal wire 21 and mounted (S22). ). Next, a sealing step of forming a sealing portion by filling the sealing layer 6 with a sealing resin having an elastic modulus of 2.5 GPa or more and 3.5 GPa or less and a glass transition temperature of 413 K or more in a concave portion is performed ( S23). As the sealing resin, for example, a modified acrylate resin or the like may be used in addition to the epoxy resin. Next, the lens unit 5 made of a resin having an elastic modulus of 3 GPa or more is formed on the sealing resin (S24). As the resin of the lens portion 5, for example, a modified acrylate resin or the like may be used in addition to the epoxy resin. As a method of forming the lens portion 5, for example, by using a transfer molding method, the shape and surface accuracy of the lens portion 5 can be molded with high accuracy.
[0055]
A thermal shock test was performed on an optical system device having a sealing portion having a multilayer structure manufactured by the above-described process. As a comparative example, an optical system device having a single structure in which the process from sealing of the optical element to the formation of the lens portion was formed only of the resin of the lens portion was also manufactured and subjected to the same thermal shock test. Table 2 shows the physical properties and curing conditions of the resins used.
[0056]
[Table 2]

[0057]
The thermal shock test was performed in the liquid phase, and one cycle was performed at 233 K (−40 ° C.) × 5 minutes and at 358 K (85 ° C.) × 5 minutes. As a result of the thermal shock test, the optical device having a multilayer structure according to the present invention was all good products up to 500 cycles. Peeling occurred at the boundary surface of, and all were defective.
[0058]
As described above, even in the optical system device 20 having the two-layer structure of the sealing resin and the lens unit, the elasticity of the resin to be filled in the upper space of the optical element is appropriately selected and used, so that the overall performance is improved. In addition, due to the synergistic effect with the interface bonding force, a vacuum void in the resin and peeling of the resin interface occur in a temperature environment of −40 ° C. to 85 ° C. due to a synergistic effect with the interface bonding force. An optical device with improved durability and reliability was obtained.
[0059]
An example of still another manufacturing method will be described. In the case where the resin layer is formed into a multilayer, the lower layer resin may be dropped, and the upper resin having a lower specific gravity than the lower layer resin may be dropped on the upper surface thereof, and then these resins may be cured. According to such a method, since the boundary surface between the two sealing resins is formed in a liquid state, they are compatible with each other, and when the two sealing resins are cured, a chemical bond is formed at an interface between the resins so that the bonding strength is reduced. improves. Further, since a resin having a specific gravity smaller than that of the resin in the lower layer is used for the upper layer, mixing of the resins is prevented.
[0060]
For the thermal shock test, the resin of the first layer (lower layer) was dropped using the resin shown in Table 1, and then the resin of the first layer was not cured, and the second layer having a lower specific gravity than the first layer was not cured. The resin of the (upper layer) was dropped, the resin of the second layer was dropped, and then UV irradiation was performed under the condition of 6 J / cm 2 to produce an optical device in which the resins of the first and second layers were cured. A thermal shock test was performed on the optical system device manufactured by this method and the optical system device manufactured by a normal method. As a result, after 1000 cycles, the sample manufactured by the normal method peeled off the interface between the first layer and the second layer and became defective, whereas the sample manufactured by the method according to the present invention failed on the first and second layers. All products were non-defective at the interface.
[0061]
As still another example, the metallized surface of the concave portion for mounting the optical element may be roughened and filled with a sealing resin. According to this method, it is possible to obtain an effect that light incident on the metallized surface is diffused by the rough surface and stray light is reduced, and an interface effect of the sealing resin filled in the concave portion due to an anchor effect that the resin bites into the rough surface. The effect is improved.
[0062]
For the thermal shock test, an optical system device was manufactured by using the resin shown in Table 1 and setting the surface roughness Ry of the metallized surface to 1 μm or more. In the case of this optical system device, all were good products after the thermal shock test of 1000 cycles, but as a comparative example, when the surface roughness Ry was less than 1 μm, defective products were generated due to peeling of the metallized surface and the resin. Further, in the optical system device according to the present method, the loss in the optical characteristics can be reduced by 5% compared to the normal case due to the reduction of the stray light due to the diffusion on the metallized surface.
[0063]
As yet another example, as shown in FIGS. 7A and 7B, a portion where the substrate resin is exposed on the bottom surface of the metallized concave portion, for example, a crescent-shaped substrate resin exposed portion 16 may be formed. In this configuration, since the sealing resin and the substrate resin to be filled in the concave portion are bonded to each other at the exposed portion, a stronger bonding force of the sealing resin than the bonding through the metallized surface can be obtained. For example, the optical system devices having the structure shown in FIG. 7 using the resins shown in Table 1 were all good after 1000 cycles of the thermal shock test, while those having the entire bottom surface metallized were peeled off. Became defective.
[0064]
In addition to the above structure, as shown in FIGS. 8A and 8B, a groove 7 in which the substrate resin is exposed may be formed on the bottom surface of the metalized concave portion. In this configuration, since the sealing resin is injected into the groove 7, in addition to the same effect as described above, the bonding area between the sealing resin and the substrate resin is increased, and a stronger bonding force of the sealing resin is obtained. For example, the optical system devices having the structure shown in FIG. 7 using the resins shown in Table 1 were all good after 1500 cycles of the thermal shock test, but those having the above-mentioned exposed portions without grooves were It became defective due to peeling.
[0065]
As still another example, these resins may be cured by injecting a resin for forming a lens portion with the degree of crosslinking of the sealing resin being 50 to 80%. According to such a method, the hardening agent of the resin for forming the lens unit is used to accelerate the curing of the sealing resin in the lower layer of the lens unit, and a chemical bond between the resin for the lens unit and the sealing resin is formed. The bonding strength with the resin is improved. Further, the control of the degree of crosslinking of the sealing resin may be performed by the heating time during curing of the resin. By changing the heating time, it is possible to easily control and change the degree of cross-linking to manufacture.
[0066]
For the thermal shock test, for example, using the resin shown in Table 2, the sealing resin was heated at 408 ° C. for 30 minutes in a constant temperature bath to crosslink 70%, and an optical system in which a lens portion was formed thereon The device was made. When a thermal shock test was performed on this optical system device, no defect occurred after 1000 cycles. As a comparative example, what was heated at 408 ° C. × 2 hours to promote the crosslinking reaction to form 85% of the crosslinking and then formed a lens portion thereon was subjected to a thermal shock test of 1000 cycles to obtain a sealing resin and a lens portion resin. Peeled off at the interface of the sample, and became defective. In the case where the lens portion was resin-molded to the one which was heated at 408 ° C. × 15 minutes and crosslinked by 45%, molding failure in which the sealing resin was flown by the pressure during resin molding resulted.
[0067]
FIG. 9 shows still another example. As shown in FIG. 9A, the sealing resin 6 used in the sealing step immediately before the lens forming step is filled with an ultraviolet curing resin to seal the optical element 2 in the opened concave portion of the resin substrate 1. Next, the rough surface of the transparent member 7 formed of an ultraviolet light transmitting material having a roughened surface is adhered to the sealing resin 6 and arranged. In this state, the sealing resin 6 is cured by irradiating the sealing resin 6 with ultraviolet light through the transparent member 7. According to such a method, as shown in FIG. 9B, a rough surface structure 61 transferred from the surface of the transparent member is formed on the surface of the cured sealing resin 6. On the sealing resin having the rough surface structure 61, the lens portion 5 is resin-molded as shown in FIG. As a result, the bonding strength between the lens resin 5 and the sealing resin 6 is improved.
[0068]
A thermal shock test was performed on the optical device manufactured by the above-described process. First, after the sealing resin is dropped, a flat plate having a surface roughness Ry of 1.5 μm formed of an ultraviolet light transmitting material is brought into close contact with the sealing resin, and the sealing resin is irradiated with ultraviolet light through the flat plate and cured. I let it. As a result, a sealing resin having a surface roughness Ry of 1.5 μm was obtained. The lens part was formed on the roughened sealing resin. When the sample after molding the lens portion was subjected to a thermal shock test, no failure occurred at 1000 cycles. Table 3 shows the physical properties and curing conditions of the resin used.
[0069]
[Table 3]

[0070]
Still another example is shown in FIGS. The opening concave portion for mounting the optical element 2 is provided at the tip of a lens barrel 12 formed of a protruding portion of the resin substrate 1. After mounting the optical element 2, the sealing resin 3, 4 or the sealing resin 6 is filled and cured, and then the lens unit 5 is formed in a shape having a resin 51 covering the outer surface of the protruding lens barrel 12. In such

optical system devices

40 and 50, since the resin forming the lens portion 5 covers the outer surface of the projecting lens barrel 12, the area of the interface between the lens portion forming resin and the substrate resin is increased. be able to. Therefore, moisture absorption into the inside of the sealing portion through the interface is reduced, and deterioration of the optical element can be prevented. Further, since the sealing resin inside is wrapped by the strongly formed lens portion resin, the separation between the sealing resin and the lens resin can be prevented.
[0071]
A thermal shock test was performed on the above-described optical system device. The materials used are the same as in Table 1. An optical system device 40 shown in FIG. 9A was manufactured by molding the lens resin outside the lens barrel by transfer molding. When a thermal shock test of 1000 cycles was performed on this optical system device, no separation between the lens resin and the substrate resin occurred. As a comparative example, a thermal shock test of 1000 cycles was performed on an optical system device in which a lens portion was formed only at the upper part of the lens barrel. As a result, interface separation between the lens portion resin and the substrate resin occurred, resulting in a failure.
[0072]
As still another example, after the resin forming the lens portion is cured in the lens forming step, the resin may be cooled from the curing temperature to room temperature at a cooling rate slower than room temperature cooling. In such a method, since cooling can be performed while controlling the cooling time while relaxing the thermal stress, peeling of the resin interface due to sudden shrinkage and generation of cracks in the resin can be prevented. For example, using the resin shown in Table 1, the lens portion is molded with resin and cured at 423K. Then, a sample of the optical system device is taken out of the molding die, put into a thermostat, and cooled to 300K at 1K per minute for 1 minute. did. When a thermal shock test was performed on this sample, no defect occurred after 1000 cycles.
[0073]
The present invention can be variously modified without being limited to the above configuration. For example, when laminating the sealing resin, or laminating the lens resin to the sealing resin, after forming the lower layer resin, for example, using an atmospheric pressure plasma device, the cleaning / activation of the resin surface is performed, A treatment for improving the wettability / interfacial bonding strength between the resin layers may be performed.
[Brief description of the drawings]
FIG. 1 is a sectional view of an optical system device according to an embodiment of the present invention.
FIG. 2 is a perspective view of an optical element mounting portion of the above device.
FIGS. 3A to 3E are cross-sectional views illustrating manufacturing steps of the above device.
FIG. 4 is a process flow chart of a method for manufacturing the above device.
FIG. 5 is a sectional view showing another example of the optical system device according to the embodiment of the present invention.
FIG. 6 is a process flow chart of a method for manufacturing the above device.
FIG. 7A is a plan view showing still another example of the optical device according to the embodiment of the present invention, and FIG. 7B is a cross-sectional view of the device.
FIG. 8A is a plan view showing still another example of the optical device according to the embodiment of the present invention, and FIG. 8B is a cross-sectional view of the device.
9A is a cross-sectional view illustrating a method for manufacturing an optical device according to an embodiment of the present invention, FIG. 9B is a partial cross-sectional view of the device, and FIG. 9C is a cross-sectional view of the device.
FIGS. 10A and 10B are cross-sectional views showing still another example of the optical system device according to the embodiment of the present invention.
11A and 11B are cross-sectional views of a conventional optical system device.
12A and 12B are cross-sectional views of another conventional optical system device.
13A and 13B are cross-sectional views of still another conventional optical system device.
FIG. 14 is a cross-sectional view illustrating a conventional semiconductor chip sealing structure.
[Explanation of symbols]
1 Resin substrate
2 Optical element
3 sealing layer
4 Sealing layer
5 Lens section
6 sealing layer
13 recess
14 Metallized surface
10,20,30,40,50 Optical system device

Claims

An optical device in which an optical element is mounted in an open concave portion of a resin substrate,
The resin substrate is made of a low elastic modulus resin of 10 GPa or less,
The surface of the open concave portion of the resin substrate is metallized to have a light reflecting function and an electric circuit function,
The optical element mounted on the bottom surface of the metallized recess is sealed with a first sealing layer made of a resin having an elastic modulus of 1 Pa or more and 1 MPa or less and a glass transition temperature of 213 K or more and 233 K or less,
A second sealing layer made of an ultraviolet curable resin having a glass transition temperature of 1 GPa or more and 2.5 GPa or less and a glass transition temperature of 413 K or more is formed on the first sealing layer,
An optical device, wherein a lens portion made of a resin having an elastic modulus of 3 GPa or more is formed on the second sealing layer.

An optical device in which an optical element is mounted in an open concave portion of a resin substrate,
The resin substrate is made of a low elastic modulus resin of 10 GPa or less,
The surface of the open concave portion of the resin substrate is metallized to have a light reflecting function and an electric circuit function,
The optical element mounted on the bottom surface of the metallized concave portion is sealed with a sealing layer made of a resin having an elastic modulus of 2.5 GPa or more and 3.5 GPa or less and a glass transition temperature of 413 K or more,
An optical device, wherein a lens portion made of a resin having an elastic modulus of 3 GPa or more is formed on the sealing layer.

3. The optical system according to claim 1, wherein the metallized surface of the recess is roughened.

4. The optical system device according to claim 1, wherein a portion where the substrate resin is exposed is formed on a bottom surface of the metallized concave portion.

5. The optical system device according to claim 4, wherein a groove in which the substrate resin is exposed is formed on the bottom surface of the metallized concave portion, and a sealing resin is injected into the groove.

2. The open concave portion is provided at a tip of a lens barrel projecting from a resin substrate, and a resin forming the lens unit covers an outer surface of the projecting lens barrel. Item 3. The optical device according to Item 2.

A method for manufacturing an optical device in which an optical element is mounted in an open concave portion of a resin substrate,
A mounting step of mounting an optical element on the bottom surface of the metalized concave portion, wherein an open concave portion of the resin substrate made of a low elastic modulus resin of 10 GPa or less is metallized to have a reflection function and an electric circuit function;
A first sealing step of forming a first sealing layer with a resin having an elastic modulus of 1 Pa to 1 MPa and a glass transition temperature of 213 K to 233 K to seal the optical element;
A second sealing step of forming a second sealing layer with a UV-curable resin having an elastic modulus of 1 GPa or more and 2.5 GPa or less and a glass transition temperature of 413 K or more and sealing the first sealing layer;
A lens forming step of forming a lens portion made of a resin having an elastic modulus of 3 GPa or more on the sealed resin layer.

In the first sealing step and the second sealing step, a resin of a first sealing layer is dropped, and a resin of a second sealing layer having a lower specific gravity than the resin is dropped on an upper surface of the resin. 8. The method according to claim 7, wherein the resin is cured.

A method for manufacturing an optical device in which an optical element is mounted in an open concave portion of a resin substrate,
A step of mounting an optical element on the bottom surface of the metalized concave portion, in which an open concave portion of a resin substrate made of a low elastic modulus resin of 10 GPa or less is metallized so as to have a reflection function and an electric circuit function;
A sealing step of forming a sealing layer with a resin having an elastic modulus of 2.5 GPa or more and 3.5 GPa or less and a glass transition temperature of 413 K or more to seal the optical element;
A lens forming step of forming a lens portion made of a resin having an elastic modulus of 3 GPa or more on the sealing layer.

10. The method according to claim 9, wherein after the sealing resin is dropped in the sealing step, the resin for forming the lens portion is injected and cured in a state where the degree of crosslinking of the resin is 50 to 80%. A manufacturing method of the optical system device described in the above.

11. The method according to claim 10, wherein the degree of crosslinking of the sealing resin is controlled by a heating time at the time of curing the resin.

The sealing resin used in the sealing step immediately before the lens forming step is an ultraviolet curing resin, and the rough surface of a transparent member formed of an ultraviolet light transmitting material having a roughened surface is bonded to the sealing resin. And irradiating the sealing resin with ultraviolet light through the transparent member to cure the sealing resin and transfer a rough surface shape of the transparent member to the sealing resin surface. 10. A method for manufacturing an optical system device according to claim 9.

10. The optical system device according to claim 7, wherein after the resin forming the lens portion is cured in the lens forming step, the resin is cooled from a curing temperature to a normal temperature at a cooling rate slower than the normal temperature cooling. Production method.