JP4120473B2

JP4120473B2 - Molding method and mold for fine molded product, and molded product manufactured by the method

Info

Publication number: JP4120473B2
Application number: JP2003148329A
Authority: JP
Inventors: 雅也平田
Original assignee: Matsushita Electric Works Ltd
Current assignee: Panasonic Electric Works Co Ltd
Priority date: 2003-05-26
Filing date: 2003-05-26
Publication date: 2008-07-16
Anticipated expiration: 2023-05-26
Also published as: JP2004351614A

Description

【０００１】
【発明の属する技術分野】
本発明は、微細形状を有する樹脂成形品と成形品を成形するための成形型及び成型方法に関する。
【０００２】
【従来の技術】
従来、微細形状を有する樹脂成形品を成形し、できた成形品を変形やクラックを生じさせることなく成形型から離型させる成形方法が工夫して行われている。例えば、半導体素子の樹脂封止成形後に離型させる方法について、図１２を参照して説明する（例えば、特許文献１参照）。図１２（ａ）に示すように、リードフレーム１２１を間に挟み込んだ状態でパーティラインＰＬで突き合わせた上型１０１と下型１０４によりキャビテイ空間１０３、１０６が形成される。このキャビティ空間に、図１２（ｂ）に示すように、樹脂１２２が充填される。樹脂が硬化した後、図１２（ｃ）に示すように、上型１０１と下型１０４が上下に分離され、間隙１３０が形成される（予備型開工程）。この間隙は、キャビティ空間に形成された隙間空間１３１が、下型１０４に設けられたシール材１０７によって封止される程度の隙間である。このような状態で、上型１０１、下型１０４に設けられたエア導入通路１０２、１０５から圧縮エアが吹き込まれる。この圧縮エアによって硬化した樹脂１２３が成形型から離型される。その後、図１２（ｄ）に示すように、成形品１２４が成形型から取り出される。
【０００３】
【特許文献１】
特開２００２−１８７１７５号公報
【０００４】
【発明が解決しようとする課題】
しかしながら、上述した図１２や特許文献１に示されるような成形方法や、離型方法においては、次のような問題がある。上型と下型と突き合わせてキャビティを構成する場合、キャビティの全周囲において上型・下型の対向面を均一に突き合わせて封止することが難しい。突き合わせ面による十分な封止構造が構成できない場合、ごく微小な隙間から低粘度の封止樹脂が流出するため、成形品への圧力付与ができないという問題がある。
【０００５】
また、流出した樹脂が圧縮エアの導入通路を塞ぐため、成形品を離型できない可能性がある。また、予備型開工程において、樹脂成形品と上型間、及び樹脂成形品と下型間に同程度の隙間が常に生じるということはなく、樹脂成形品は上下のどちらか一方に片寄った状態で隙間が生じる。その結果、気体が片方の隙間に選択的に出り込み、成形毎に上型部で離型したり、下型部で離型したりするので、安定した離型作業を行うことができないという問題がある。
【０００６】
本発明は、上記課題を解消するものであって、簡単な構成により微細形状を有する成形品を変形／破損することなく型から離型できる微細成形品の成形方法と成形型及びその方法により製造された成形品を提供することを目的とする。
【０００７】
【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、表面に微細な凹凸形状を施した成形型を用いてその凹凸形状が転写された成形品を圧縮又は射出圧縮成形する方法において、前記成形型よりも小さい弾性率を有し、上方に開口するキャビティを備えたキャビティ部材を前記成形型の所定位置に配置するステップと、前記ステップの後、前記キャビティ内に樹脂液を注入し、硬化させると共に、前記成形型により前記キャビティ内の樹脂を前記キャビティ部材と共に圧縮して成形品を成形するステップと、前記成形品を成形するステップの後、前記成形型の凹凸形状を施した面から前記成形品又はキャビティ部材の表面に向けて加圧気体を噴出することにより、前記成形型から成形品を離型させる離型ステップとを有する圧縮又は射出圧縮成形方法である。
【０００８】
上記方法においては、成形型の凹凸形状を施した面から成形品又はキャビティ部材の表面に向けて加圧気体を噴出することにより成形型から成形品を離型させるので、離型時に成形品の凹凸形状が転写された面とその面に接する凹凸形状を有する成形型の面との間に確実に加圧気体を圧入してその面間で離型を行うことができる。他の面間に加圧気体が回り込むことなく、成形品の微細な凹凸形状が転写された面が最初に離型されるので、成形品全体の離型が確実、かつ容易となり、安定した離型が可能となり、離型時の成形品の欠けの防止や、成形作業の効率化が図れる。
【０００９】
請求項２の発明は、請求項１に記載の圧縮又は射出圧縮成形方法において、前記離型ステップは、離型の後に成形品をキャビティ部材と共に成形型より取り出すステップを有するものである。
【００１０】
上記方法においては、離型の後に成形品をキャビティ部材と共に成形型より取り出すので、キャビティ部材と成形品との間の接合力が強い場合であっても、離型時に成形品の欠けや変形を生じることなく成形品を成形型から取り出すことができる。また、成形毎に又は成形品毎にキャビティ部材を交換することにより、成形品の材質に応じたキャビティ部材を選定でき、成形樹脂変更の場合においても成形型の変更の必要がなくなる。
【００１１】
請求項３の発明は、請求項２に記載の圧縮又は射出圧縮成形方法において、前記離型ステップでの加圧気体の噴出は、前記キャビティ部材のガラス転移温度近傍の温度で行うものである。
【００１２】
上記方法においては、キャビティ部材のガラス転移温度近傍の温度で加圧気体の噴出を行うので、加圧気体の熱で軟化したキャビティ部材と成形型との密着性が上がり、加圧気体の気密性をより確実に確保でき、加圧気体を効率的に成形品の離型に用いることができる。
【００１３】
請求項４の発明は、請求項２に記載の圧縮又は射出圧縮成形方法において、前記キャビティ部材として、注入した樹脂液を保持する底のあるキャビティを備えたものを用いるものである。この方法においては、底のあるキャビティにより成形材料の樹脂漏れを防止できる。
【００１４】
請求項５の発明は、請求項２に記載の圧縮又は射出圧縮成形方法において、前記キャビティ部材として、側壁が逆テーパとなっているキャビティを備えたものを用いるものである。この方法においては、キャビティ側壁の逆テーパ部分により成形品が保持されるので、離型時に成形品がキャビティ部材から分離することなく、成形品と成形型との間で確実に離型できる。
【００１５】
請求項６の発明は、請求項２に記載の圧縮又は射出圧縮成形方法において、前記キャビティ部材として、成形時の収縮率が成形品よりも大きい樹脂材料を用いるものである。
【００１６】
上記方法においては、離型の後に成形品をキャビティ部材と共に成形型より取り出す場合に、収縮したキャビティ部材により成形品を保持して確実に取り出すことができる。
【００１７】
請求項７の発明は、請求項２に記載の圧縮又は射出圧縮成形方法において、前記キャビティ部材として、成形品と同じ母材の樹脂を用いるものである。
【００１８】
上記方法においては、離型の後に成形品をキャビティ部材と共に成形型より取り出す場合に、キャビティ部材と成形品との接触部にゆるみが発生することがなく、キャビティ部材により成形品を保持して確実に取り出すことができる。
【００１９】
請求項８の発明は、キャビティ内に樹脂液を注入し、その樹脂液を硬化させて樹脂成形を行う成形型であって、下面に微細な凹凸形状部を配設し、その外側に下方に向けて加圧気体を噴出するための噴出口を有する上型と、前記上型の周囲に上下方向摺動可能に配設したキャビティ部材押さえ型と、前記上型の微細な凹凸形状と対向する上面を有する下型と、上方に開口したキャビティを有し前記上型の微細な凹凸形状部にその開口を対向して前記下型の上面に配設されるキャビティ部材とを備えた成形型である。
【００２０】
上記成形型においては、上型の下面に微細な凹凸形状部を配設し、その外側に下方に向けて加圧気体を噴出するための噴出口を備え、キャビティ部材押さえ型を上型の周囲に上下方向摺動可能に配設し、上方に開口したキャビティを上型の微細な凹凸形状部に対向して下型の上面に配設するキャビティ部材をの周辺部を抑える構成としているので、表面に微細な凹凸形状が転写された成形品を次のように効率よく製造することができる。上型とキャビティ部材押さえ型とにより、キャビティ内に樹脂液を注入して硬化させた樹脂を、圧縮成形した後、加圧気体噴出口から成形品の凹凸形状が転写された面とその面に接する凹凸形状を有する成形型の面との間に確実に加圧気体を圧入してその面間で離型を行うことができる。
【００２１】
また、成形品の凹凸形状が転写された面側から加圧気体を噴出し、また、キャビティ部材がキャビティ部材押さえ型により抑えられて加圧気体の機密性が保たれるので、他の面間に加圧気体が回り込むことなく、成形品の微細な凹凸形状が転写された面が最初に離型される。従って、この成形型を用いると、成形品全体の離型が確実、かつ容易となり、安定した離型が可能となり、成形品の離型時の欠けの防止や、成形作業の効率化が図れる。
【００２２】
請求項９の発明は、請求項８に記載の成形型において、押さえ型の表面でかつ噴出口よりも外側に、上型と樹脂成形された成形品との接触界面を包含する空間を気密封止するためのシール材を備えたものである。この成形型においては、離型のための加圧気体の気密性を確保して安定した離型ができる。
【００２３】
請求項１０の発明は、請求項９に記載の成形型において、前記シール材が、成形品よりも低い弾性率を有する材質で構成されたものである。この成形型においては、上記効果に加え、加圧気体（圧縮気体）の圧力が大きくなり過ぎた場合に、シール材が変形することにより加圧気体を逃がすことができ、異常圧力による成形品の塑性変形を防ぐことができる。
【００２４】
請求項１１の発明は、請求項８に記載の成形型において、前記噴出口が、前記キャビティ部材の開口を避けて配置されているものである。この成形型においては、圧縮成形時に、樹脂液が離型時に用いる加圧気体噴出口に流入することがなく、効率的に離型を行うことができる。
【００２５】
請求項１２の発明は、請求項８に記載の成形型において、前記噴出口に連通する溝が、前記上型の下面に設けられているものである。この成形型においては、加圧気体を上型と樹脂成形された成形品との凹凸形状を有する接触界面に均等な圧力で噴出することができ、離型時の成形品の変形を抑えることができ、また離型を安定して行うことができる。
【００２６】
上述のいずれかの製造方法を用いて成形された成形品は、上型と樹脂成形された成形品との凹凸形状を有する接触界面を加圧気体を用いて確実に離型したものなので、微細な凹凸形状を転写した面に傷がなく、信頼性の高い品質のばらつきの少ない成形品となっている。
【００２７】
【発明の実施の形態】
以下、本発明の一実施形態に係る微細成形品の成形方法と成形型及びその方法により製造された成形品について図面を参照して説明する。まず、成形方法の概要について説明する。図１は本発明の一実施形態に係る圧縮又は射出圧縮成形方法の工程フローを示す。本方法による成形品は、表面に微細な凹凸形状を施した成形型を用いて樹脂材料を圧縮又は射出圧縮してその凹凸形状を転写して形成される。上下に分離した成形型の間に、成形型よりも小さい弾性率を有し、上方に開口するキャビティを備えたキャビティ部材を下成形型（下型）の所定位置に配置する（Ｓ１）。次に、キャビティ内に樹脂液を注入し、硬化させ（Ｓ２）、成形型を閉じてキャビティ内の樹脂を圧縮して成形品を成形する（Ｓ３）。次に、成形型の凹凸形状を施した面から成形品又はキャビティ部材の表面に向けて加圧気体を噴出して成形品を離型させる（Ｓ４）。その後、成形型を上下に型開きして成形品をキャビティ部材とともに取り出して工程が終了する（Ｓ５）。
【００２８】
成形型について説明する。図２は本発明の一実施形態に係る成形型の構成を示し、図３はその変形例の構成を示す。両図とも、成形品９を離型した状態を示している。図２に示す成形型は、上型１、その周りのキャビティ部材押さえ型４、下型６、下型６の上に載置して用いられるキャビティ部材７などからなる。上型１は、成形機のダイプレート１０に設置されている。上型１の下面には微細な凹凸形状部２が配設され、その外側には下方に向けて加圧気体を噴出するための噴出口３が配設されている。下型６は、上型１の微細な凹凸形状部２と対向する上面を有している。キャビティ部材７は、上方に開口した孔からなる底のないキャビティ７１を有し、上型１の微細な凹凸形状部２にその開口を対向させて、下型６の上面に配設される。これにより、下型６の上面平面部によってキャビティ部材７のキャビティ７１に底部が構成される。
【００２９】
また、キャビティ部材押さえ型４は、上型１の周囲において上下方向に摺動可能に配設されている。キャビティ部材押さえ型４と上型１とが対向して互いに摺動する面には、例えばＯリングからなるシール材５が設けられている。
【００３０】
成形機の動作を説明する。成形時には、ダイプレート１０が上方から下降した状態で、上型１の下面１８（及びそこに設けられた微細凹凸形状部２）が、ダイプレート１０の付勢力により、キャビティ部材７（及びキャビティ内の樹脂）を圧縮する。また、キャビティ部材押さえ型４は、成形機のダイプレート１０に設けられたばね部材１１によって下方に付勢されており、そのばね部材１１の付勢力により、キャビティ部材７に当接している。
【００３１】
離型時には、上下の成形型、シール材５，キャビティ部材７，キャビティ部材７、及びキャビティ部材押さえ型４によって封止された空間が形成される。キャビティ部材押さえ型４は、ばね部材１１による付勢力によって上型１から下方に突出しており、その先端部分がキャビティ部材７の周辺部に当接した面は、加圧気体を封止するシール面となっている。
【００３２】
また、離型後の型開きは、加圧気体の噴出に伴うキャビティ内の圧力上昇に応じて、成形機のダイプレート１０を上昇させて行われる。型開き動作の開始は、加圧気体の圧力を検知するか、図示しないダイプレートの駆動源にかかる負荷を検知することによって行われる。
【００３３】
次に、図３に示す成形型について説明する。この成形型のキャビティ部材押さえ型４は、ばね部材を介さずに成形機のダイプレート１０に設置されている。また、上型１は、ダイプレート１０に設置された、例えば油圧シリンダやエアシリンダからなる駆動源１２で駆動されるシリンダロッド１３に設置されている。前出の図２に示したものと、上型１及びキャビティ部材押さえ型４の上下駆動、又は付勢方法が異なるが、これらの型の機能は同じである。
【００３４】
この成形型における離型後の型開きは、加圧気体の噴出に伴うキャビティ内の圧力上昇に応じて、ダイプレート１０に設置された駆動源１２を駆動して行われる。型開き動作の開始は、加圧気体の圧力を検知するか、駆動源１２にかかる負荷を検知することによって行われる。
【００３５】
次に、成形型の動きと合わせて樹脂成形の工程を説明する。図４（ａ）〜（ｇ）は成形型の断面により成形工程を順に示している。まず、図４（ａ）に示す型開き状態で、図４（ｂ）に示すようにキャビティ部材７を下型６の平面で構成された上面に設置する。これにより、下型６の上面平面部によってキャビティ部材７のキャビティ７１に底部が構成される。このとき、上型１の凹凸形状部２にキャビティ部材７のキャビティ７１の開口が対向するように配置する。また、上型１に設けられた、図示しない圧空源と連通した噴出口３の延長方向は、キャビティ７１の内部方向（点Ｐ方向）になっている。
【００３６】
続いて、図４（ｃ）に示すように、キャビティ７１内に成形用の樹脂８を投入する。この投入方法として、成形型が開いた状態で樹脂投入する方法の他に、成形型を閉じた状態で射出成形機やトランスファ成形機等を用いて、閉じたキャビティ７１内に樹脂を注入してもよい。樹脂注入に続いて、上型１を下降させ、図４（ｄ）に示すように、樹脂８から硬化・固化した、又は硬化・固化しつつある成形品９を加圧する。このとき、成形品９の硬化（あるいは固化）に伴って成形品９が収縮し、キャビティ７１内の成形品９の体積が減少するが、その減少量に応じて、一定の加圧力を与えるように上型を下降させる。なお、上型を下降させる代わりに下型を上昇するようにしてもよい。
【００３７】
この圧縮成形の工程において、キャビティ部材７が成形型１，６よりも小さい弾性率を有する材料（例えば、エラストマー又は樹脂材料）で構成されているため、上型の下降に追従して、キャビティ部材が変形することができる。その結果、成形品９に対し、上型１の微細凹凸形状部２の微細形状を成形品に十分に転写できる加圧力を加えることが可能となる。また、キャビティ部材７が、成形型１，６よりも小さい弾性率を有する材料（例えば、エラストマーや樹脂材料）で構成されているため、キャビティ７１内を封止することができるので、低粘度の成形樹脂がキャビティ７１から漏れ出すことがない。また、キャビティ部材７を成形品の材質に応じて選定できるので、成形品の樹脂変更の場合、成形型の改良を行うことなくキャビティ部材７の変更によって対応することができる。
【００３８】
圧縮成形により微細形状を転写し、成形材料が硬化（あるいは固化）した後、離型工程が開始される。離型工程は、図示しない圧空源と連通した噴出口３よりキャビティ７１内に向って加圧気体３０を噴出して行われる。この状態において、キャビティ部材７が成形型１，６よりも小さい弾性率を有する材料（例えば、エラストマーや樹脂材料）で構成されているため、キャビティ７１内がシールされる構造となり、加圧気体３０がキャビティ７１から漏れ出すことがない。
【００３９】
このような状態で、加圧気体３０の噴出に伴うキャビティ７１内の圧力が上昇すると、図４（ｅ）に示すように、圧力上昇にともなって上型１が上方に摺動し、上型１の凹凸形状部２から成形品が離型する。このような離型工程によれば、凹凸形状部２と成形品との界面Ｓに加圧気体が確実に流入するので、離型時に成形品の微細形状転写部が破損することなく確実に離型される。このあと、、図４（ｆ）（ｇ）に示すように、上型１とキャビティ部材押さえ型４が、下型６から離れて、完全に型開き状態とされ、表面に転写された微細形状２０を有する成形品９がキャビティ部材７と共に成形型から取り出される。
【００４０】
次に、本発明の一実施形態に係る他の成形型による成形の工程を説明する。図５（ａ）〜（ｄ）は成形型の断面により成形工程を順に示している。この成形型の上型１は、上述したいずれかの成形型における上型１とキャビティ部材押さえ型４とを併せ持った構造及び機能を有している。図５（ａ）に示すように、上型１の凹凸形状部２を有する下面１８において、噴出口３と凹凸形状部２とを囲むように周状の突起１５が設けられている。この突起１５がキャビティ部材押さえ型４に代わる機能を有している。
【００４１】
前出の図４における説明と同様に、図５（ｂ）（ｃ）に示すように、キャビティ７１内に成型用樹脂８を投入し、上型１により成形品９に一定の加圧力を与えて、成形品９を成形する。圧縮成形の離型工程において、前記同様に噴出口３よりキャビティ７１内に向って加圧気体３０を噴出する。この状態において、噴出口３と凹凸形状部２とを囲むように周状の突起１５を設けているので、キャビティ７１を含む空間がシールされる構造となり、加圧気体３０がキャビティ７１から漏れ出すことがない。
【００４２】
このような状態で、加圧気体３０の噴出に伴うキャビティ７１内の圧力が上昇すると、図５（ｄ）に示すように、圧力上昇にともなって上型１が上方に摺動し、上型１の凹凸形状部２から成形品が離型する。離型の初期段階である上型１の上昇開始時において、上型１がキャビティ部材７から離れた状態であっても、下方に突出した突起１５がキャビティ部材７に圧接された状態が維持される。従って、上型１の上昇の初期段階おいてもキャビティ７１内の圧力が高く保たれており、離型がスムーズに行われる。突起１５を有する上型１と、成形型１，６よりも小さい弾性率を有する材料（例えば、エラストマーや樹脂材料）で構成されたキャビティ部材７を用いたこのような離型工程によれば、凹凸形状部２と成形品との界面Ｓに加圧気体が確実に流入するので、離型時に成形品の微細形状転写部が破損することなく確実に離型される。
【００４３】
次に、本発明の一実施形態に係る他の成形の方法を説明する。この成形方法は、上述したような圧縮又は射出圧縮成形方法におけるいずれかの離型工程において、加圧気体３０の噴出を、キャビティ部材７のガラス転移温度近傍の温度で行うものである。キャビティ部材７に熱可塑性樹脂等を用いた場合、ガラス転移温度近傍において、キャビティ部材の弾性率が、キャビティ部材に当接した部材との接触面に良好なシール性能を生じるものとなる。従って、ガラス転移点温度近傍で加圧気体を噴出することにより、キャビティ空間のシール性を特に高くでき、凹凸形状を施した成形型と成形品の離型を良好に行うことができる。
【００４４】
次に、本発明の一実施形態に係るさらに他の成形型による成形の工程を説明する。図６（ａ）〜（ｄ）は成形型の断面により成形工程を順に示している。この成形型におけるキャビティ部材７は、図６（ａ）に示すように、底７２を有している。このため、図６（ｂ）（ｃ）に示すように、キャビティ７１内に成型用樹脂８を投入し、上型１により成形品９に一定の加圧力を与え加圧する際、樹脂漏れが生じる可能性を極力低減できるので、キャビティ内の気密性をより確実とすることができる。
【００４５】
また、図６（ｃ）（ｄ）に示すように、離型工程において、前記同様に噴出口３よりキャビティ７１内に向って加圧気体３０を噴出する。この状態において、キャビティ部材が有底であるためキャビティ内が確実にシールされる構造となり、加圧気体３０がキャビティ７１から漏れ出すことがなく、凹凸形状部２と成形品９の界面Ｓに加圧気体３０が確実に流入するので、離型時に成形品９の微細形状転写部が破損することなく確実に離型することができる。なお、この成形型における噴出口３は、キャビティ７１の開口よりも外部に加圧気体を噴出する構成になっている。この点については、後出の図９において説明する。
【００４６】
次に、本発明の一実施形態に係るさらに他の成形型による成形の工程を説明する。図７（ａ）〜（ｄ）は成形型の断面により成形工程を順に示している。この成形型におけるキャビティ部材７は、図７（ａ）に示すように、逆テーパとなった側壁７３により形成されたキャビティ７１を有している。このようなキャビティ部材７を用いて、図６（ｂ）〜（ｄ）に示すように、キャビティ７１内への成型用樹脂８の投入、加圧成形を行い、成形品の離型を行うとき、キャビティ部材７の逆テーパとなった側壁７３が成形品９を保持するので、成形品９がキャビティ７部材から分離することなく、成形品９と上型１との界面Ｓで確実に離型できる。
【００４７】
次に、本発明の一実施形態に係るさらに他の成形型による成形について説明する。この成形方法は、キャビティ部材として成形品（成形材料）よりも成形収縮率が大きい材料の樹脂を用いるものである。成形時に樹脂が収縮する過程において、キャビティ部材と成形材料との密着圧が高くなり、キャビティ部材と成形材料との界面におけるシール性が高くなる。その結果、微細凹凸形状を施した成形型と成形品の離型を良好に行うことができる。成形材料として、例えば、ポリプロピレン樹脂（成形収縮率１〜１．２％）を用いた場合、キャビティ部材として、例えばオレフイン系エラストマー樹脂（成形収縮率１．５〜２．５％）等を用いると良好な成形を行うことができる。
【００４８】
次に、本発明の一実施形態に係るさらに他の成形型による成形について説明する。この成形方法は、キャビティ部材として成形品（成形材料）と同じ母材の樹脂を用いるものである。成形時に、キャビティ部材と成形材料とが融着し、キャビティ部材と成形材料との界面におけるシール性が高くなる。その結果、微細凹凸形状を施した成形型と成形品の離型を良好に行うことができる。
【００４９】
成形材料として、例えば、フィラー入り樹脂を用いた場合、キャビティ部材としてはフィラー無し、又はフィラーの含有量が成形材料よりも少ない樹脂を用いると良好な成形を行うことができる。また、キャビティ部材として成形品（成形材料）と同じ部材の樹脂を用いない場合においても、融着可能な樹脂同士であれば、キャビティ部材と成形材料との界面における良好なシール性を得ることができ、同様の硬化が得られる。例えば、成形材料として、ＰＭＭＡ樹脂を用いた場合、キャビティ部材としてポリカーポネート樹脂を用いると良好な成形を行うことができる。
【００５０】
次に、本発明の一実施形態に係るさらに他の成形型による成形の工程を説明する。図８（ａ）〜（ｅ）は成形型の断面により成形工程を順に示している。この成形型の上型１には、前出の図５に示した上型１における周状の突起１５にかわるものとして、図８（ａ）に示すように、噴出口３と凹凸形状部２とを囲むように上型１に○リング等のシール材５が設けられている。このシール材５により、上型１とキャビティ部材７との接触面において上型１の凹凸形状部２と成形品の界面Ｓの封止がなされる。
【００５１】
このような上型１を用いて、図８（ｂ）（ｃ）に示すように、キャビティ７１内へ成型用樹脂８を投入し、加圧成形を行うとき、シール材５が変形するため、上型１とキャビティ部材７が直接当接してキャビティ内が封止され、加圧が有効に行われる。
【００５２】
また、図８（ｄ）に示すように、成形品の離型を行うとき、キャビティ部材が成形型よりも小さい弾性率を有する材料（例えば、エラストマーや樹脂材料）で構成されているため、キャビティ内がシールされる構造となり、噴出口よりキャビティ内に向って噴出した加圧気体がキャビティから漏れ出すことがない。また、加圧気体の噴出に伴うキャビティ内の圧力上昇に応じて上型が上方に摺動するとき、上型１の微細形状を有する面において、噴出口３と凹凸形状部とを囲むように上型１と成形品９の界面Ｓを気密封止するためのＯリング等のシール材５を備えているので、キャビティを含む空間がシールされる構造となり、加圧気体３０が漏れ出すことがなく、成形品９を上型１の凹凸形状部から確実に離型することができる。
【００５３】
また、図８（ｅ）に示すように、加圧気体の圧力が大きくなり過ぎた場合、シール材５が成形品９よりも低い弾性率を有する材質で構成されているため、シール材５が変形して過剰な気体をキャビティ外に逃がすことが可能となる。これにより、成形品の塑性変形を防ぐこともできる。
【００５４】
次に、本発明の一実施形態に係るさらに他の成形型による成形の工程を説明する。図９（ａ）〜（ｄ）は成形型の断面により成形工程を順に示している。この成形型の特徴は、図９（ａ）に示すように、上型１に設けられた噴出口３が、キャビティ部材７のキャビティ７１の開口を避けて配置されたところにある。図９（ｂ）に示すように、噴出口３の加圧気体噴出方向は、キャビティ部材の周辺部の点Ｑに向かう方向になっている。
【００５５】
このような成形型を用いて、図９（ｂ）（ｃ）に示すように、キャビティ内へ成型用樹脂８を投入し、加圧成形を行うとき、樹脂液が噴出口３に流入することがない。噴出口３が、樹脂を投入するキャビティではなくキャビティ部材７と対向する位置にあるため、例えば、成形材料に熱硬化性樹脂等の低粘度樹脂を用いても、成型用樹脂が噴出口３から中に入り込むことがない。従って、微細形状を転写し、成形材料が硬化（あるいは固化）した後、噴出口３からキャビティ内に向って加圧気体を噴出する際、安定した再現性のある効果的な気体の噴出によって離型が確実に行われる。
【００５６】
次に、本発明の一実施形態に係るさらに他の成形型について説明する。図１０（ａ）は上型の断面を示し、図１０（ｂ）その上型の凹凸形状部を有する下面の平面図を示す。この上型１は、加圧気体の噴出口３に連続したリング状の溝３１を上型１の凹凸形状部２を有する下面１８に、凹凸形状部２を囲むように配置している。このような溝３１を有する上型１の構造によれば、凹凸形状部２の外周から均等に加圧気体をキャビティ内に噴出することができるため、成形品の転写された凹凸形状部において、離型時の成形品の変形を抑えることができ、また離型を安定して効果的に行うことが可能となる。
【００５７】
また、図１１（ａ）（ｂ）は、上記の上型の変形例を示す。この上型１は、複数個の噴出口３を有しており、その配置は凹凸形状部２に対して対称となる位置とされている。また、それらの噴出口３は、互いにリング状の溝３１で連通されている。このような複数の噴出口と溝を有する構造によれば、加圧気体を上型と樹脂成形された成形品との凹凸形状を有する接触界面により均等な圧力で噴出することができる。
【００５８】
以上に説明したような成形型及び成形方法を用いて成形された成形品は、上型と樹脂成形された成形品との凹凸形状を有する接触界面を加圧気体を用いて確実に離型したものなので、微細な凹凸形状を転写した面に傷がなく、信頼性の高い品質のばらつきの少ない成形品となっている。
【図面の簡単な説明】
【図１】本発明の一実施形態に係る圧縮又は射出圧縮成形方法の工程フロー図。
【図２】本発明の一実施形態に係る成形型の構成を示す断面図。
【図３】本発明の一実施形態に係る他の成形型の構成を示す断面図。
【図４】（ａ）〜（ｇ）は本発明の一実施形態に係る圧縮又は射出圧縮成形方法及び成形型による成形を工程順に示す成形型の断面図。
【図５】（ａ）〜（ｄ）は本発明の一実施形態に係る成形型による成形を工程順に示す成形型の断面図。
【図６】（ａ）〜（ｄ）は本発明の一実施形態に係る他の成形型による成形を工程順に示す成形型の断面図。
【図７】（ａ）〜（ｄ）は本発明の一実施形態に係るさらに他の成形型による成形を工程順に示す成形型の断面図。
【図８】（ａ）〜（ｅ）は本発明の一実施形態に係るさらに他の成形型による成形を工程順に示す成形型の断面図。
【図９】（ａ）〜（ｄ）は本発明の一実施形態に係るさらに他の成形型による成形を工程順に示す成形型の断面図。
【図１０】（ａ）は本発明の一実施形態に係るさらに他の成形型の断面図、（ｂ）は（ａ）に示す成形型のＡ−Ａ線矢視平面図。
【図１１】（ａ）は本発明の一実施形態に係るさらに他の成形型の断面図、（ｂ）は（ａ）に示す成形型のＡ−Ａ線矢視平面図。
【図１２】（ａ）〜（ｂ）は従来の成形型及び成形方法による成形を工程順に示す成形型の断面図。
【符号の説明】
１上型
２凹凸形状部
３噴出口
４キャビティ部材押さえ型
５シール材
６下型
７キャビティ部材
８樹脂
９成形品
１８下面
３０加圧気体
３１溝
７１キャビティ
７２底
７３側壁
Ｓ界面[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a resin molded product having a fine shape and a molding die and a molding method for molding the molded product.
[0002]
[Prior art]
Conventionally, a molding method in which a resin molded product having a fine shape is molded and the resulting molded product is released from the mold without causing deformation or cracking has been devised. For example, a method of releasing after resin-sealing molding of a semiconductor element will be described with reference to FIG. 12 (for example, see Patent Document 1). As shown in FIG. 12A, the cavity spaces 103 and 106 are formed by the upper mold 101 and the lower mold 104 that are abutted by the party line PL with the lead frame 121 sandwiched therebetween. This cavity space is filled with a resin 122 as shown in FIG. After the resin is cured, as shown in FIG. 12C, the upper mold 101 and the lower mold 104 are separated into upper and lower portions, and a gap 130 is formed (preliminary mold opening process). This gap is such that the gap space 131 formed in the cavity space is sealed by the sealing material 107 provided in the lower mold 104. In such a state, compressed air is blown from the air introduction passages 102 and 105 provided in the upper mold 101 and the lower mold 104. The resin 123 cured by the compressed air is released from the mold. Thereafter, as shown in FIG. 12D, the molded product 124 is taken out from the mold.
[0003]
[Patent Document 1]
JP 2002-187175 A
[0004]
[Problems to be solved by the invention]
However, the molding method and the mold release method as shown in FIG. 12 and Patent Document 1 described above have the following problems. When configuring the cavity by matching the upper mold and the lower mold, all It is difficult to seal the opposing surfaces of the upper mold and the lower mold evenly in the periphery. When a sufficient sealing structure with the butted surfaces cannot be formed, there is a problem in that pressure cannot be applied to the molded product because the sealing resin with low viscosity flows out from a very small gap.
[0005]
Further, since the resin that has flowed out closes the compressed air introduction passage, the molded product may not be released. Also, in the preliminary mold opening process, there is not always the same gap between the resin molded product and the upper mold, and between the resin molded product and the lower mold, and the resin molded product is in a state of being biased to either the upper or lower side A gap occurs. As a result, gas selectively flows into one of the gaps and is released at the upper mold part or released at the lower mold part for each molding, so that stable release work cannot be performed. There's a problem.
[0006]
The present invention solves the above-described problems, and a molding method, a molding die, and a molding method for a micro-molded product that can be released from a mold without deforming / damaging a molded product having a fine shape with a simple configuration. It is an object to provide a molded product.
[0007]
[Means for Solving the Problems and Effects of the Invention]
In order to achieve the above object, the invention of claim 1 is a method of compressing or injection compression molding a molded product having a concavo-convex shape transferred thereon using a mold having a fine concavo-convex shape on the surface. A step of disposing a cavity member having a cavity having an elastic modulus smaller than that of the mold and opening upward at a predetermined position of the molding die; and after the step, a resin liquid is injected into the cavity and cured. And the resin in the cavity by the mold With the cavity member Compressing and molding the molded article; and Molding a molded product After the step, a mold release step for releasing the molded product from the molding die by ejecting a pressurized gas from the surface of the molding die having a concavo-convex shape toward the surface of the molded product or the cavity member. A compression or injection compression molding method.
[0008]
In the above method, the molded product is released from the molding die by ejecting the pressurized gas from the surface of the molding die having the uneven shape toward the molded product or the surface of the cavity member. It is possible to perform mold release between the surfaces by reliably injecting pressurized gas between the surface having the concavo-convex shape transferred thereon and the surface of the mold having the concavo-convex shape in contact with the surface. Since the surface to which the fine unevenness of the molded product is transferred is released first without the pressurized gas flowing between the other surfaces, the entire molded product is released reliably and easily, and stable release. The mold becomes possible, and it is possible to prevent chipping of the molded product at the time of mold release and to improve the efficiency of the molding operation.
[0009]
According to a second aspect of the present invention, in the compression or injection compression molding method according to the first aspect, the mold release step includes a step of taking out the molded product together with the cavity member from the mold after the mold release.
[0010]
In the above method, the molded product is taken out from the mold together with the cavity member after the mold release, so that even when the bonding force between the cavity member and the molded product is strong, the molded product is not chipped or deformed during the mold release. The molded product can be taken out from the mold without being generated. In addition, by exchanging the cavity member for each molding or for each molded product, the cavity member can be selected according to the material of the molded product, and there is no need to change the molding die even when the molding resin is changed.
[0011]
According to a third aspect of the present invention, in the compression or injection compression molding method according to the second aspect, the injection of the pressurized gas in the releasing step is performed at a temperature near the glass transition temperature of the cavity member.
[0012]
In the above method, since the pressurized gas is ejected at a temperature in the vicinity of the glass transition temperature of the cavity member, the adhesion between the cavity member softened by the heat of the pressurized gas and the mold is improved, and the airtightness of the pressurized gas is increased. Can be ensured more reliably, and the pressurized gas can be efficiently used for releasing the molded product.
[0013]
A fourth aspect of the present invention is the compression or injection compression molding method according to the second aspect, wherein the cavity member is provided with a cavity having a bottom for holding the injected resin liquid. In this method, the resin leakage of the molding material can be prevented by the cavity having the bottom.
[0014]
According to a fifth aspect of the present invention, in the compression or injection compression molding method according to the second aspect of the present invention, the cavity member is provided with a cavity having a side wall having a reverse taper. In this method, since the molded product is held by the reverse tapered portion of the cavity side wall, the molded product can be reliably released between the molded product and the mold without being separated from the cavity member at the time of mold release.
[0015]
A sixth aspect of the present invention is the compression or injection compression molding method according to the second aspect, wherein a resin material having a shrinkage ratio at the time of molding larger than that of the molded product is used as the cavity member.
[0016]
In the above method, when the molded product is taken out of the mold together with the cavity member after the mold release, the molded product can be held and reliably taken out by the contracted cavity member.
[0017]
A seventh aspect of the present invention is the compression or injection compression molding method according to the second aspect, wherein a resin of the same base material as the molded product is used as the cavity member.
[0018]
In the above method, when the molded product is taken out of the mold together with the cavity member after the mold release, the contact portion between the cavity member and the molded product is not loosened, and the molded product is securely held by the cavity member. Can be taken out.
[0019]
The invention according to claim 8 is a mold for injecting a resin liquid into a cavity and curing the resin liquid to perform resin molding. An upper die having a jet port for jetting pressurized gas toward the surface, a cavity member pressing die disposed around the upper die so as to be slidable in the vertical direction, and a fine uneven shape of the upper die. A mold comprising: a lower mold having an upper surface; and a cavity member that has a cavity opened upward and is disposed on the upper surface of the lower mold so that the opening is opposed to the fine uneven portion of the upper mold. is there.
[0020]
In the molding die, a fine uneven portion is disposed on the lower surface of the upper die, and has a jet outlet for jetting pressurized gas downward on the outer side thereof, and the cavity member pressing die is arranged around the upper die. Since the cavity is arranged to be slidable in the vertical direction and the cavity opened upward is opposed to the fine uneven shape part of the upper mold and arranged on the upper surface of the lower mold, the peripheral part of the cavity member is suppressed, A molded product having a fine irregular shape transferred on the surface can be efficiently produced as follows. After the resin molded by injecting the resin liquid into the cavity and being cured by the upper mold and the cavity member pressing mold, the resin is compressed and formed on the surface to which the concave and convex shape of the molded product is transferred from the pressurized gas ejection port. Pressurized gas can be reliably injected between the surfaces of the forming mold having the concavo-convex shape in contact, and the mold can be released between the surfaces.
[0021]
In addition, the pressurized gas is ejected from the side of the surface of the molded product where the concave and convex shape is transferred, and the cavity member is suppressed by the cavity member holding die to maintain the confidentiality of the pressurized gas. The surface to which the fine uneven shape of the molded product is transferred is released first without the pressurized gas flowing around. Therefore, when this mold is used, it is possible to release the entire molded product reliably and easily, enabling stable mold release, preventing chipping when the molded product is released, and improving the efficiency of the molding operation.
[0022]
According to a ninth aspect of the present invention, in the molding die according to the eighth aspect, a space including the contact interface between the upper die and the resin molded molded product is hermetically sealed on the surface of the pressing die and on the outer side of the ejection port. It is provided with a sealing material for stopping. In this mold, stable release can be achieved while ensuring the airtightness of the pressurized gas for release.
[0023]
According to a tenth aspect of the present invention, in the molding die according to the ninth aspect, the sealing material is made of a material having an elastic modulus lower than that of the molded product. In this mold, in addition to the above effects, when the pressure of the pressurized gas (compressed gas) becomes too large, the pressurized gas can be released by the deformation of the sealing material, and the molded product caused by abnormal pressure Plastic deformation can be prevented.
[0024]
An eleventh aspect of the present invention is the molding die according to the eighth aspect, wherein the ejection port is disposed so as to avoid the opening of the cavity member. In this mold, at the time of compression molding, the resin liquid does not flow into the pressurized gas outlet used at the time of mold release, and the mold can be released efficiently.
[0025]
According to a twelfth aspect of the present invention, in the molding die according to the eighth aspect, a groove communicating with the jet port is provided on the lower surface of the upper die. In this mold, the pressurized gas can be ejected to the contact interface having the concavo-convex shape between the upper mold and the resin-molded molded article with equal pressure, and the deformation of the molded article at the time of mold release can be suppressed. In addition, the mold release can be performed stably.
[0026]
Above Molded using any manufacturing method The Since the molded product is a mold that reliably releases the contact interface with the concavo-convex shape between the upper mold and the resin-molded product using pressurized gas, the surface to which the fine concavo-convex shape is transferred is not damaged and is reliable. It is a molded product with high quality and little variation in quality.
[0027]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a molding method and a molding die for a fine molded product according to an embodiment of the present invention and a molded product manufactured by the method will be described with reference to the drawings. First, an outline of the molding method will be described. FIG. 1 shows a process flow of a compression or injection compression molding method according to an embodiment of the present invention. The molded product according to this method is formed by compressing or injection-compressing a resin material using a molding die having a fine uneven shape on the surface and transferring the uneven shape. A cavity member having a smaller elastic modulus than that of the mold and having a cavity opened upward is disposed at a predetermined position of the lower mold (lower mold) between the upper and lower molds (S1). Next, a resin liquid is injected into the cavity and cured (S2), the mold is closed, and the resin in the cavity is compressed to form a molded product (S3). Next, a pressurized gas is ejected from the surface of the molding die having the concavo-convex shape toward the surface of the molded product or the cavity member to release the molded product (S4). Thereafter, the mold is opened up and down, the molded product is taken out together with the cavity member, and the process ends (S5).
[0028]
The mold will be described. FIG. 2 shows the configuration of a mold according to an embodiment of the present invention, and FIG. 3 shows the configuration of a modification thereof. Both figures show a state in which the molded product 9 is released. The molding die shown in FIG. 2 includes an upper die 1, a cavity member pressing die 4 around the upper die 1, a lower die 6, a cavity member 7 used by being placed on the lower die 6. The upper mold 1 is installed on a die plate 10 of a molding machine. A fine concavo-convex shape portion 2 is disposed on the lower surface of the upper mold 1, and an ejection port 3 for ejecting pressurized gas downward is disposed on the outside thereof. The lower mold 6 has an upper surface that faces the fine uneven portion 2 of the upper mold 1. The cavity member 7 has a bottomless cavity 71 formed of a hole opened upward, and is disposed on the upper surface of the lower mold 6 with the opening opposed to the fine concavo-convex shape portion 2 of the upper mold 1. As a result, the bottom portion is formed in the cavity 71 of the cavity member 7 by the upper surface flat portion of the lower mold 6.
[0029]
Further, the cavity member pressing die 4 is disposed so as to be slidable in the vertical direction around the upper die 1. A sealing material 5 made of, for example, an O-ring is provided on the surfaces where the cavity member pressing die 4 and the upper die 1 face each other and slide with each other.
[0030]
The operation of the molding machine will be described. At the time of molding, the lower surface 18 of the upper mold 1 (and the fine uneven portion 2 provided thereon) is moved by the urging force of the die plate 10 while the die plate 10 is lowered from above. The resin). The cavity member pressing die 4 is biased downward by a spring member 11 provided on a die plate 10 of the molding machine, and abuts against the cavity member 7 by the biasing force of the spring member 11.
[0031]
At the time of mold release, a sealed space is formed by the upper and lower molding dies, the sealing material 5, the cavity member 7, the cavity member 7, and the cavity member holding die 4. The cavity member pressing mold 4 protrudes downward from the upper mold 1 by the urging force of the spring member 11, and the surface of the cavity member 7 that is in contact with the peripheral portion of the cavity member 7 is a sealing surface that seals pressurized gas. It has become.
[0032]
Moreover, the mold opening after mold release is performed by raising the die plate 10 of the molding machine in accordance with the pressure increase in the cavity accompanying the ejection of the pressurized gas. The mold opening operation is started by detecting the pressure of the pressurized gas or detecting a load applied to a driving source of a die plate (not shown).
[0033]
Next, the mold shown in FIG. 3 will be described. The cavity member pressing mold 4 of the molding die is installed on the die plate 10 of the molding machine without using a spring member. Further, the upper mold 1 is installed on a cylinder rod 13 that is installed on a die plate 10 and is driven by a drive source 12 such as a hydraulic cylinder or an air cylinder. Although the upper die 1 and the cavity member pressing die 4 are vertically driven or biased differently from those shown in FIG. 2, the functions of these die are the same.
[0034]
The mold opening after the mold release in the mold is performed by driving the drive source 12 installed on the die plate 10 in accordance with the pressure increase in the cavity accompanying the ejection of the pressurized gas. The mold opening operation is started by detecting the pressure of the pressurized gas or detecting a load applied to the drive source 12.
[0035]
Next, the resin molding process will be described together with the movement of the mold. 4 (a) to 4 (g) sequentially show the molding process by the cross section of the mold. First, in the mold open state shown in FIG. 4A, the cavity member 7 is installed on the upper surface constituted by the plane of the lower mold 6 as shown in FIG. 4B. As a result, the bottom portion is formed in the cavity 71 of the cavity member 7 by the upper surface flat portion of the lower mold 6. At this time, it arrange | positions so that the opening of the cavity 71 of the cavity member 7 may oppose the uneven | corrugated shaped part 2 of the upper mold | type 1. FIG. Further, the extending direction of the jet port 3 provided in the upper mold 1 and communicating with a pressure air source (not shown) is the internal direction of the cavity 71 (point P direction).
[0036]
Subsequently, as shown in FIG. 4C, the molding resin 8 is put into the cavity 71. As this charging method, in addition to the method of charging the resin in a state where the mold is open, the resin is injected into the closed cavity 71 using an injection molding machine, a transfer molding machine or the like with the mold closed. Also good. Following the resin injection, the upper mold 1 is lowered, and the molded product 9 cured or solidified from the resin 8 or being cured / solidified is pressurized as shown in FIG. At this time, the molded product 9 contracts as the molded product 9 is cured (or solidified), and the volume of the molded product 9 in the cavity 71 is reduced. However, a certain pressure is applied according to the amount of decrease. Lower the upper die. Instead of lowering the upper mold, the lower mold may be raised.
[0037]
In this compression molding process, the cavity member 7 is made of a material having an elastic modulus smaller than that of the molds 1 and 6 (for example, an elastomer or a resin material). Can be deformed. As a result, it is possible to apply a pressing force that can sufficiently transfer the fine shape of the fine uneven portion 2 of the upper mold 1 to the molded product 9. Further, since the cavity member 7 is made of a material having an elastic modulus smaller than that of the molds 1 and 6 (for example, an elastomer or a resin material), the inside of the cavity 71 can be sealed. Molding resin does not leak from the cavity 71. Further, since the cavity member 7 can be selected according to the material of the molded product, the resin of the molded product can be changed by changing the cavity member 7 without improving the molding die.
[0038]
After the fine shape is transferred by compression molding and the molding material is cured (or solidified), the mold release process is started. The mold release process is performed by ejecting the pressurized gas 30 from the ejection port 3 communicating with a pressure air source (not shown) toward the cavity 71. In this state, since the cavity member 7 is made of a material having an elastic modulus smaller than that of the molds 1 and 6 (for example, an elastomer or a resin material), the cavity 71 is sealed, and the pressurized gas 30 Does not leak from the cavity 71.
[0039]
In this state, when the pressure in the cavity 71 increases as the pressurized gas 30 is ejected, the upper mold 1 slides upward as the pressure increases, as shown in FIG. The molded product is released from the 1 uneven portion 2. According to such a mold release process, the pressurized gas surely flows into the interface S between the concavo-convex shape portion 2 and the molded product, so that the micro shape transfer portion of the molded product can be reliably released without being damaged at the time of mold release. Typed. Thereafter, as shown in FIGS. 4F and 4G, the upper die 1 and the cavity member pressing die 4 are separated from the lower die 6 and are completely opened, and transferred to the surface. The molded product 9 having 20 is taken out of the mold together with the cavity member 7.
[0040]
Next, a molding process using another mold according to an embodiment of the present invention will be described. 5A to 5D show the molding process in order by the cross section of the mold. The upper mold 1 of this mold has a structure and a function having both the upper mold 1 and the cavity member pressing mold 4 in any of the molds described above. As shown in FIG. 5A, a circumferential protrusion 15 is provided on the lower surface 18 of the upper mold 1 having the concave and convex portion 2 so as to surround the jet port 3 and the concave and convex portion 2. The protrusion 15 has a function to replace the cavity member pressing die 4.
[0041]
Similarly to the description in FIG. 4 described above, as shown in FIGS. 5B and 5C, the molding resin 8 is introduced into the cavity 71, and a constant pressure is applied to the molded product 9 by the upper mold 1. Thus, the molded product 9 is formed. In the mold release step of compression molding, the pressurized gas 30 is ejected from the ejection port 3 into the cavity 71 as described above. In this state, since the circumferential projection 15 is provided so as to surround the ejection port 3 and the concavo-convex shape portion 2, the structure including the cavity 71 is sealed, and the pressurized gas 30 leaks from the cavity 71. There is nothing.
[0042]
In this state, when the pressure in the cavity 71 increases as the pressurized gas 30 is ejected, the upper mold 1 slides upward as the pressure increases, as shown in FIG. The molded product is released from the 1 uneven portion 2. Even when the upper mold 1 starts to be lifted, which is the initial stage of mold release, even when the upper mold 1 is separated from the cavity member 7, the state in which the protrusion 15 protruding downward is pressed against the cavity member 7 is maintained. The Therefore, the pressure in the cavity 71 is kept high even in the initial stage of the upper mold 1 rising, and the mold release is performed smoothly. According to such a mold release step using the upper mold 1 having the protrusions 15 and the cavity member 7 made of a material having an elastic modulus smaller than that of the molds 1 and 6 (for example, an elastomer or a resin material) Since the pressurized gas surely flows into the interface S between the concavo-convex shape portion 2 and the molded product, the fine shape transfer portion of the molded product is surely released without being damaged at the time of release.
[0043]
Next, another molding method according to an embodiment of the present invention will be described. In this molding method, the pressurized gas 30 is ejected at a temperature in the vicinity of the glass transition temperature of the cavity member 7 in any mold release step in the compression or injection compression molding method as described above. When a thermoplastic resin or the like is used for the cavity member 7, the elastic modulus of the cavity member in the vicinity of the glass transition temperature results in good sealing performance on the contact surface with the member in contact with the cavity member. Therefore, by ejecting the pressurized gas in the vicinity of the glass transition temperature, the sealing performance of the cavity space can be made particularly high, and the mold having the irregular shape and the mold can be favorably released.
[0044]
Next, a molding process using still another mold according to an embodiment of the present invention will be described. 6 (a) to 6 (d) sequentially show the molding process by the cross section of the mold. The cavity member 7 in this mold has a bottom 72 as shown in FIG. For this reason, as shown in FIGS. 6B and 6C, when the molding resin 8 is put into the cavity 71 and a constant pressure is applied to the molded product 9 by the upper mold 1 to pressurize the resin, a resin leakage occurs. Since the possibility can be reduced as much as possible, the airtightness in the cavity can be further ensured.
[0045]
Further, as shown in FIGS. 6C and 6D, in the mold release step, the pressurized gas 30 is ejected from the ejection port 3 toward the cavity 71 in the same manner as described above. In this state, the cavity member has a bottom, so that the inside of the cavity is securely sealed, and the pressurized gas 30 does not leak from the cavity 71 and is added to the interface S between the concavo-convex shape portion 2 and the molded product 9. Since the pressurized gas 30 surely flows in, the mold can be reliably released without damaging the fine shape transfer portion of the molded product 9 at the time of releasing. In addition, the jet nozzle 3 in this shaping | molding die is a structure which jets pressurized gas outside the opening of the cavity 71. FIG. This will be described later with reference to FIG.
[0046]
Next, a molding process using still another mold according to an embodiment of the present invention will be described. FIGS. 7A to 7D sequentially show the molding process by the cross section of the mold. As shown in FIG. 7A, the cavity member 7 in this mold has a cavity 71 formed by a side wall 73 having a reverse taper. When such a cavity member 7 is used, as shown in FIGS. 6B to 6D, when the molding resin 8 is injected into the cavity 71, pressure molding is performed, and the molded product is released. The side wall 73 having a reverse taper of the cavity member 7 holds the molded product 9, so that the molded product 9 does not separate from the cavity 7 member, and the mold is reliably released at the interface S between the molded product 9 and the upper mold 1. it can.
[0047]
Next, molding by still another mold according to an embodiment of the present invention will be described. In this molding method, a resin of a material having a molding shrinkage rate larger than that of a molded product (molding material) is used as the cavity member. In the process in which the resin shrinks during molding, the contact pressure between the cavity member and the molding material increases, and the sealing performance at the interface between the cavity member and the molding material increases. As a result, it is possible to favorably release the mold having a fine uneven shape and the molded product. For example, when a polypropylene resin (molding shrinkage ratio of 1 to 1.2%) is used as the molding material, for example, an olefin elastomer resin (molding shrinkage ratio of 1.5 to 2.5%) or the like is used as the cavity member. Good molding can be performed.
[0048]
Next, molding by still another mold according to an embodiment of the present invention will be described. This molding method uses a resin of the same base material as the molded product (molding material) as the cavity member. At the time of molding, the cavity member and the molding material are fused, and the sealing performance at the interface between the cavity member and the molding material is improved. As a result, it is possible to favorably release the mold having a fine uneven shape and the molded product.
[0049]
For example, when a resin containing a filler is used as the molding material, good molding can be performed if the cavity member has no filler or a resin having a filler content smaller than that of the molding material. Even when the resin of the same member as the molded product (molding material) is not used as the cavity member, good sealing performance at the interface between the cavity member and the molding material can be obtained as long as the resins can be fused. And a similar cure is obtained. For example, when PMMA resin is used as the molding material, good molding can be performed by using polycarbonate resin as the cavity member.
[0050]
Next, a molding process using still another mold according to an embodiment of the present invention will be described. 8A to 8E show the molding process in order by the cross section of the mold. As shown in FIG. 8 (a), the upper die 1 of this molding die is replaced with a peripheral projection 15 in the upper die 1 shown in FIG. The upper mold 1 is provided with a sealing material 5 such as a ring. The sealing material 5 seals the interface S between the concave and convex portion 2 of the upper mold 1 and the molded product at the contact surface between the upper mold 1 and the cavity member 7.
[0051]
As shown in FIGS. 8B and 8C, when the molding resin 8 is introduced into the cavity 71 and pressure molding is performed using such an upper mold 1, the sealing material 5 is deformed. The upper die 1 and the cavity member 7 are in direct contact with each other to seal the inside of the cavity, so that pressurization is effectively performed.
[0052]
Further, as shown in FIG. 8D, when the molded product is released, the cavity member is made of a material having an elastic modulus smaller than that of the mold (for example, an elastomer or a resin material). The inside is sealed, and the pressurized gas ejected from the ejection port into the cavity does not leak from the cavity. Further, when the upper mold slides upward in accordance with the pressure increase in the cavity accompanying the ejection of the pressurized gas, the surface of the upper mold 1 having the fine shape surrounds the ejection port 3 and the concavo-convex shape portion. Since the sealing material 5 such as an O-ring for hermetically sealing the interface S between the upper mold 1 and the molded product 9 is provided, the space including the cavity is sealed, and the pressurized gas 30 may leak out. In addition, the molded product 9 can be reliably released from the concavo-convex shape portion of the upper mold 1.
[0053]
Further, as shown in FIG. 8E, when the pressure of the pressurized gas becomes too large, the sealing material 5 is made of a material having a lower elastic modulus than that of the molded product 9, so that the sealing material 5 Deformation allows excess gas to escape out of the cavity. Thereby, plastic deformation of the molded product can also be prevented.
[0054]
Next, a molding process using still another mold according to an embodiment of the present invention will be described. FIGS. 9A to 9D show the molding steps in order by the cross section of the molding die. The feature of this mold is that, as shown in FIG. 9A, the jet port 3 provided in the upper mold 1 is arranged avoiding the opening of the cavity 71 of the cavity member 7. As shown in FIG. 9B, the pressurized gas ejection direction of the ejection port 3 is a direction toward the point Q in the peripheral portion of the cavity member.
[0055]
Using such a mold, as shown in FIGS. 9B and 9C, when the molding resin 8 is introduced into the cavity and pressure molding is performed, the resin liquid flows into the ejection port 3. There is no. Since the spout 3 is located at a position facing the cavity member 7 instead of the cavity into which the resin is charged, for example, even if a low-viscosity resin such as a thermosetting resin is used as the molding material, the molding resin is discharged from the spout 3. I can't get inside. Therefore, after the fine shape is transferred and the molding material is cured (or solidified), when the pressurized gas is ejected from the ejection port 3 into the cavity, the gas is separated by an effective gas ejection with stable reproducibility. The mold is made surely.
[0056]
Next, still another mold according to an embodiment of the present invention will be described. FIG. 10A shows a cross section of the upper mold, and FIG. 10B shows a plan view of the lower surface of the upper mold having the uneven portion. In the upper mold 1, a ring-shaped groove 31 continuous to the pressurized gas ejection port 3 is arranged on the lower surface 18 of the upper mold 1 having the concave and convex portion 2 so as to surround the concave and convex portion 2. According to the structure of the upper mold 1 having such a groove 31, since the pressurized gas can be uniformly injected into the cavity from the outer periphery of the uneven portion 2, in the uneven portion to which the molded product is transferred, The deformation of the molded product at the time of mold release can be suppressed, and the mold release can be performed stably and effectively.
[0057]
FIGS. 11A and 11B show a modification of the upper mold. The upper mold 1 has a plurality of jet nozzles 3, and the arrangement thereof is a position that is symmetrical with respect to the concavo-convex shape portion 2. Moreover, these jet nozzles 3 are connected with each other by a ring-shaped groove 31. According to such a structure having a plurality of ejection openings and grooves, the pressurized gas can be ejected at a uniform pressure through the contact interface having an uneven shape between the upper mold and the resin molded molded product.
[0058]
The molded product molded using the molding die and the molding method as described above, the contact interface having the concavo-convex shape between the upper mold and the resin molded molded product was reliably released using a pressurized gas. As a result, there are no scratches on the surface to which the fine concavo-convex shape is transferred, and the molded product has high reliability and little variation in quality.
[Brief description of the drawings]
FIG. 1 is a process flow diagram of a compression or injection compression molding method according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view showing a configuration of a mold according to an embodiment of the present invention.
FIG. 3 is a cross-sectional view showing the configuration of another mold according to an embodiment of the present invention.
4A to 4G are cross-sectional views of a molding die showing a compression or injection compression molding method according to an embodiment of the present invention and molding by the molding die in order of steps.
FIGS. 5A to 5D are cross-sectional views of a molding die showing the molding by the molding die according to one embodiment of the present invention in the order of steps.
FIGS. 6A to 6D are cross-sectional views of a molding die showing, in the order of steps, molding by another molding die according to an embodiment of the present invention.
FIGS. 7A to 7D are cross-sectional views of a molding die showing, in the order of steps, molding by still another molding die according to an embodiment of the present invention.
FIGS. 8A to 8E are cross-sectional views of a molding die showing molding by another molding die according to one embodiment of the present invention in the order of steps.
FIGS. 9A to 9D are cross-sectional views of a molding die showing, in the order of steps, molding with still another molding die according to an embodiment of the present invention.
10A is a cross-sectional view of still another mold according to an embodiment of the present invention, and FIG. 10B is a plan view of the mold shown in FIG.
11A is a cross-sectional view of still another mold according to an embodiment of the present invention, and FIG. 11B is a plan view of the mold shown in FIG.
FIGS. 12A to 12B are cross-sectional views of a molding die showing molding by a conventional molding die and molding method in the order of steps.
[Explanation of symbols]
1 Upper mold
2 Uneven shape
3 spout
4 Cavity member holding mold
5 Sealing material
6 Lower mold
7 Cavity member
8 Resin
9 Molded products
18 Bottom
30 Pressurized gas
31 groove
71 cavity
72 bottom
73 side wall
S interface

Claims

In a method of compressing or injection compression molding a molded product having the concavo-convex shape transferred using a mold having a fine concavo-convex shape on the surface,
Disposing a cavity member having a smaller elastic modulus than the mold and having a cavity opened upward at a predetermined position of the mold; and
After the step, injecting a resin liquid into the cavity and curing the resin, and compressing the resin in the cavity together with the cavity member by the molding die, and molding a molded product;
After the step of molding the molded product, the molded product is released from the mold by ejecting a pressurized gas from the surface of the molding die having a concavo-convex shape toward the molded product or the surface of the cavity member. And a mold release step for compression or injection compression molding.

The compression or injection compression molding method according to claim 1, wherein the releasing step includes a step of taking out the molded product together with the cavity member from the forming die after releasing.

The compression or injection compression molding method according to claim 2, wherein the ejection of the pressurized gas in the releasing step is performed at a temperature near the glass transition temperature of the cavity member.

The compression or injection compression molding method according to claim 2, wherein the cavity member is provided with a cavity having a bottom for holding the injected resin liquid.

The compression or injection compression molding method according to claim 2, wherein the cavity member includes a cavity having a side wall with a reverse taper.

The compression or injection compression molding method according to claim 2, wherein a resin material having a larger shrinkage rate than that of a molded product is used as the cavity member.

The compression or injection compression molding method according to claim 2, wherein the cavity member is made of the same base material resin as that of the molded product.

A mold for injecting a resin liquid into the cavity and curing the resin liquid to perform resin molding,
An upper mold having a fine uneven portion on the lower surface and having a jet port for jetting pressurized gas downward on the outside thereof;
A cavity member pressing mold disposed so as to be slidable in the vertical direction around the upper mold;
A lower mold having an upper surface facing the fine irregular shape of the upper mold;
A mold having a cavity opened upward, and a cavity member disposed on the upper surface of the lower mold so as to face the fine concave-convex shape portion of the upper mold and facing the opening.

The sealing material for carrying out airtight sealing of the space containing the contact interface of the said upper mold | type and the resin-molded molded product on the surface of the said pressing die and the outer side of the said jet nozzle was provided. Mold.

The mold according to claim 9, wherein the sealing material is made of a material having a lower elastic modulus than that of a molded product.

The mold according to claim 8, wherein the ejection port is disposed so as to avoid the opening of the cavity member.

The mold according to claim 8, wherein a groove communicating with the jet port is provided on a lower surface of the upper mold.