JPH03295041A - Stamper for injection molding - Google Patents
Stamper for injection moldingInfo
- Publication number
- JPH03295041A JPH03295041A JP9813790A JP9813790A JPH03295041A JP H03295041 A JPH03295041 A JP H03295041A JP 9813790 A JP9813790 A JP 9813790A JP 9813790 A JP9813790 A JP 9813790A JP H03295041 A JPH03295041 A JP H03295041A
- Authority
- JP
- Japan
- Prior art keywords
- stamper
- depth
- thickness
- track groove
- molding
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000001746 injection moulding Methods 0.000 title claims description 12
- 239000004033 plastic Substances 0.000 claims abstract description 22
- 229920003023 plastic Polymers 0.000 claims abstract description 22
- 238000000465 moulding Methods 0.000 claims abstract description 18
- 239000000758 substrate Substances 0.000 claims description 34
- 230000003287 optical effect Effects 0.000 claims description 19
- 230000002093 peripheral effect Effects 0.000 abstract description 19
- 239000011347 resin Substances 0.000 abstract description 18
- 229920005989 resin Polymers 0.000 abstract description 18
- 238000000034 method Methods 0.000 description 13
- 238000002347 injection Methods 0.000 description 7
- 239000007924 injection Substances 0.000 description 7
- 239000004417 polycarbonate Substances 0.000 description 5
- 229920000515 polycarbonate Polymers 0.000 description 5
- 238000000748 compression moulding Methods 0.000 description 4
- 238000005516 engineering process Methods 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 238000007747 plating Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 2
- 238000005323 electroforming Methods 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- 229920003229 poly(methyl methacrylate) Polymers 0.000 description 2
- 229920005668 polycarbonate resin Polymers 0.000 description 2
- 239000004431 polycarbonate resin Substances 0.000 description 2
- 239000004926 polymethyl methacrylate Substances 0.000 description 2
- 239000004925 Acrylic resin Substances 0.000 description 1
- 229920000178 Acrylic resin Polymers 0.000 description 1
- 238000005266 casting Methods 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 238000004883 computer application Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000003698 laser cutting Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000005498 polishing Methods 0.000 description 1
- 238000007517 polishing process Methods 0.000 description 1
- 238000004904 shortening Methods 0.000 description 1
- 238000007711 solidification Methods 0.000 description 1
- 230000008023 solidification Effects 0.000 description 1
- 230000005236 sound signal Effects 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
- B29C45/17—Component parts, details or accessories; Auxiliary operations
- B29C45/26—Moulds
- B29C45/263—Moulds with mould wall parts provided with fine grooves or impressions, e.g. for record discs
- B29C45/2632—Stampers; Mountings thereof
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Mechanical Engineering (AREA)
- Moulds For Moulding Plastics Or The Like (AREA)
- Manufacturing Optical Record Carriers (AREA)
Abstract
Description
【発明の詳細な説明】
産業上の利用分野
本発明は光ディスク用基板を成形する際に用いられるス
タンパに関するものであり、特に、ライトワンス型およ
び追記型の高密度情報記録媒体としての光ディスクをプ
ラスチック基板を射出成形で成形する際に用いられるス
タンパ−の改良に関するものである。DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a stamper used in molding substrates for optical discs, and in particular to stampers used in molding substrates for optical discs. This invention relates to an improvement in a stamper used when molding a substrate by injection molding.
従来技術
光ディスク用基板はプラスチック、ガラス、金属、セラ
ミックス等で作ることができるが、一般にはプラスチッ
クが用いられている。このプラスチック基板は射出成形
、圧縮成形、注型等によって作ることができるが、生産
性等の観点から一般には射出成形または射出圧縮成形で
作られている。Conventional optical disk substrates can be made of plastic, glass, metal, ceramics, etc., but plastic is generally used. This plastic substrate can be made by injection molding, compression molding, casting, etc., but from the viewpoint of productivity etc., it is generally made by injection molding or injection compression molding.
射出成形技術は、オ′−ディオ信号をデジタルビットの
形で記録した光ディスク（ＣＤ）やビデオ信号をアナロ
グピントの形で記録した光ディスク（ＶＤ）において古
くから用いられており、これらの光ディスクでは一応の
技術が確立している。Injection molding technology has been used for a long time in optical discs (CDs) that record audio signals in the form of digital bits and optical discs (VDs) that record video signals in the form of analog focus. technology has been established.
しかし、コンピューター用途に用いられるライトワンス
型および追記型の高密度情報記録媒体としての光ディス
クに用いられるプラスチック基板の場合には、さらに厳
しいスペックが要求され、特に、光ディスクの外周部の
ギリギリまでピア）情報が正確に付けられていることが
要求される。However, in the case of plastic substrates used in optical disks as write-once type and write-once type high-density information recording media used for computer applications, even stricter specifications are required. It is required that the information is provided accurately.
一般に、光ディスクのプラスチック基板は、厚さが約１
．２〜１．５ｍｍで、直径が約１５０〜３００ ｍｍと
極めて薄くて偏平である上、材料としては流動性の悪い
アクリル樹脂やポリカーボネート樹脂が用いられるため
、完全に満足のゆくプラスチック基板を成形するには極
めて精密な成形技術を必要とする。これらのディスク基
板に要求される種々の性能の中で、成形品の寸法安定性
、形状安定性および転写性は重要なものであり、ディス
クの厚さ精度は１．２±０．１化であることが要求され
、さらに、成形品にそりやねじれかあってはならず、ミ
クロンオーダーの信号ピットやトラック溝がサブミクロ
ンオーダーの精度で正確且つ変形無しに転写されている
ことが要求される。Generally, the plastic substrate of an optical disk has a thickness of about 1
．． Since it is extremely thin and flat with a diameter of approximately 150 to 300 mm, and the material used is acrylic resin or polycarbonate resin, which has poor fluidity, it is possible to mold a completely satisfactory plastic substrate. requires extremely precise molding technology. Among the various performances required of these disk substrates, the dimensional stability, shape stability, and transferability of the molded product are important, and the thickness accuracy of the disk is 1.2 ± 0.1. In addition, the molded product must have no warpage or twist, and it is also required that micron-order signal pits and track grooves be accurately transferred with submicron-order accuracy and without deformation. .
このように超精密なプラスチックディスク基板は、たと
え今日開発されている最高の精密射出成形機を用いても
、成形が容易ではない。その最大の理由は、上記のよう
に極めて薄くて径の大きい成形キャビティに溶融樹脂を
均一に射出充填した場合、ゲート近傍とゲートから遠い
位置とで樹脂の固化速度および充填圧力に差が生じ、そ
の結果成形品の肉厚が不均一となり、また残留歪みが残
って成形品がそったり、ねじれたりするためである。Such ultra-precise plastic disk substrates are not easy to mold, even with the best precision injection molding machines developed today. The biggest reason for this is that when molten resin is uniformly injected and filled into a molding cavity that is extremely thin and has a large diameter as described above, there is a difference in the solidification rate and filling pressure of the resin between the vicinity of the gate and the position far from the gate. As a result, the thickness of the molded product becomes uneven, and residual strain remains, causing the molded product to warp or twist.
こうした欠点を無くすには、材料の樹脂として流動性の
良い低分子量のＰＭＭＡやＰＣを用いればよいが、ディ
スクの耐久性、耐熱性、形状安定性が悪くなるため、こ
れらの特性を維持するために、流動性の悪い高分子量の
ＰＭＭＡやＰＣを用いる必要がある。しかし、こうした
高分子量の材料を用いた場合には上記の寸法安定性、形
状安定性が悪くなるだけでなく、スタンパ−からの凹凸
信号や案内溝（トラッキング用溝）の転写性が悪くなり
、結果的に光ディスクとしての性能が低下する。In order to eliminate these drawbacks, it is possible to use low molecular weight PMMA or PC with good fluidity as the resin material, but the durability, heat resistance, and shape stability of the disc will deteriorate, so it is necessary to maintain these characteristics. Therefore, it is necessary to use high molecular weight PMMA or PC which has poor fluidity. However, when such high molecular weight materials are used, not only the dimensional stability and shape stability described above deteriorate, but also the transferability of the uneven signals and guide grooves (tracking grooves) from the stamper deteriorates. As a result, the performance of the optical disc deteriorates.
この問題点を改善するために、金型を種々工夫すること
が提案されている（−例として特開昭５６１３９９４０
号、特開昭５７−２０３５１７号を参照）。しかし、実
際にこれらの金型を用いて射出成形したプラスチック基
板の肉厚は成形キャビティの寸法と同一にはならず、中
心部が外周部に比べて相対的に肉厚になり、また、ヒケ
のため成形品の形状安定性も悪くなることが多い。その
主たる原因はこれらの金型の成形キャビティが希望する
成形品の寸法と実質的に同一寸法に作られているためで
ある。すなわち、プラスチック基板を射出成形で成形す
る際に用いられるスタンパ−は原盤にニッケノにメツキ
（電鋳）を行って作られるが、第２図の概念的な断面図
に示すように、従来のスタンパ−（１）は、スタンパ−
の厚さおよび凹凸状の信号またはトラック溝（３）は内
周側および外周側で実質的に均一になっている。In order to improve this problem, various improvements to the mold have been proposed (for example, Japanese Patent Application Laid-Open No. 56139940
No., JP-A No. 57-203517). However, the wall thickness of plastic substrates actually injection molded using these molds is not the same as the dimensions of the molding cavity, and the center part is relatively thicker than the outer periphery, and there are sink marks. Therefore, the shape stability of the molded product often deteriorates. The main reason for this is that the molding cavities of these molds are made to have substantially the same dimensions as the desired molded product. In other words, stampers used when molding plastic substrates by injection molding are made by plating (electroforming) a master plate, but as shown in the conceptual cross-sectional view of Figure 2, conventional stampers -(1) is a stamper
The thickness and the uneven signal or track groove (3) are substantially uniform on the inner and outer circumferential sides.
この欠点を改善するために提案された特開昭６０６７１
２４号、特開昭６０−１’３１６５１号に記載の方法で
は、スタンパ−の厚さにテーパーを付けて、スタンパ−
の厚みを内周部で相対的に厚くし、外周部で相対的に薄
くしている。このテーパー付きのスタンパ−を用いて成
形されたプラスチックディスク基板は、厚さが内・外周
部で均一になる。しかも、スタンパーにテーパーを付け
たことによってヒケ（樹脂の歪み）を無くすことができ
る。Japanese Patent Publication No. 60671 was proposed to improve this drawback.
In the method described in Japanese Patent Application Laid-Open No. 60-1'31651, the thickness of the stamper is tapered.
The thickness is relatively thick at the inner circumference and relatively thin at the outer circumference. A plastic disk substrate molded using this tapered stamper has a uniform thickness at the inner and outer peripheries. Furthermore, by tapering the stamper, sink marks (distortion of the resin) can be eliminated.
第３図は、本発明者らが先に提案した特開昭６０６７１
２４号の改良型スタンパ−の概念的な断１図であり、ス
タンパ−（１）の厚さを内周側に比べてその外周側を相
対的に薄くしである点が第２図のものと異なっている。Figure 3 shows Japanese Patent Application Laid-Open No. 60671, which was proposed earlier by the present inventors.
This is a conceptual cross-sectional view of the improved stamper No. 24, and is different from the one in Figure 2 in that the thickness of the stamper (1) is relatively thinner on the outer circumferential side than on the inner circumferential side. It is different from
この場合には、スタンパ−の厚みを内外周で変えること
により樹脂の流れが良くなる。In this case, resin flow can be improved by changing the thickness of the stamper between the inner and outer circumferences.
しかし、直径が３００ｍｍφである大径の光ディスク基
板を成形する場合や、小径の光ディスク基板を高サイク
ルて（射出時間を短くして）成形する場合には、外周部
へ行くにしたがって、スタンパ−の凹凸信号やトラック
溝がプラスチック基板に完全に転写されないため、この
方法で成形した光ディスク基板を用いて作られた光ディ
スクの外周部において充分な記録・再生特性が得られな
いという問題点があった。これは、ポリカーボネート樹
脂を用いて直径が３００φｍｍの大径の光ディスク基板
を射出成形した場合に特に問題となる。However, when molding a large-diameter optical disk substrate with a diameter of 300 mm, or when molding a small-diameter optical disk substrate at high cycles (shortening the injection time), the stamper Since the uneven signals and track grooves are not completely transferred to the plastic substrate, there is a problem in that sufficient recording and reproducing characteristics cannot be obtained at the outer periphery of an optical disk made using an optical disk substrate molded using this method. This becomes a particular problem when a large-diameter optical disk substrate with a diameter of 300 mm is injection molded using polycarbonate resin.
発明が解決しようとする課題
本発明の目的は上記問題点を解決して、大径のプラスチ
ック基板を成形する場合、あるいは、小径のプラスチッ
ク基板を高サイクルで成形する場合にも凹凸信号やトラ
ック溝の転写性の良い光ディスク用プラスチック基板の
射出成形用スタンバ−を提供することにある。Problems to be Solved by the Invention It is an object of the present invention to solve the above-mentioned problems, and to solve the above-mentioned problems. An object of the present invention is to provide a stamp bar for injection molding of a plastic substrate for an optical disk, which has good transferability.
課題を解決するための手段
本発明の提供する光ディスクの基板として用いられるプ
ラスチック基板を射出成形によって成形する際に用いら
れる片面に凹凸状の信号またはトラック溝を有するスタ
ンパ−は、スタンパ−の厚さが内周側に比べて外周側が
相対的に薄くなっており、且つ、上記の凹凸状の信号ま
たはトラック溝の深さがスタンパ−の内周側に比べてそ
の外周側が相対的に深くなっていることを特徴としてい
る。Means for Solving the Problems The present invention provides a stamper having an uneven signal or track groove on one side, which is used when molding a plastic substrate used as a substrate for an optical disk by injection molding. The outer circumferential side of the stamper is relatively thinner than the inner circumferential side, and the depth of the uneven signal or track groove is relatively deeper on the outer circumferential side than on the inner circumferential side of the stamper. It is characterized by the presence of
上記の内周側と外周側とでのスタンパ−の厚さ差は数ミ
クロン−数十ミクロン程度、具体的には１〜３０ミクロ
ン、好ましくは５〜２０ミクロン程度にする。また、内
周側と外周側とでの凹凸状の信号またはトラック溝の深
さの差は、数十人〜数百人、具体的には３０人〜５００
人、好ましくは５０人〜２００ 人にする。The difference in thickness of the stamper between the inner circumferential side and the outer circumferential side is about several microns to several tens of microns, specifically about 1 to 30 microns, preferably about 5 to 20 microns. In addition, the difference in the depth of the uneven signal or track groove between the inner and outer circumferential sides is several tens to hundreds of people, specifically 30 to 500 people.
number of people, preferably 50 to 200 people.
本発明のスタンパ−は任意の樹脂を用いて任意の直径の
プラスチック基板の成形に利用できるが、特に、大径の
プラスチック基板、具体的には、外径が１５０ｍｍ以上
のプラスチック基板をポリカーボネートで成形する場合
にその利点を発揮する。Although the stamper of the present invention can be used to mold plastic substrates of any diameter using any resin, it is particularly suitable for molding large diameter plastic substrates, specifically plastic substrates with an outer diameter of 150 mm or more, from polycarbonate. Its advantages are demonstrated when
作用
本発明によりスタンパ−の凹凸状の信号またはトラック
溝の深さをスタンパの内周側に比べてその外周側が相対
的に深くなるようにしたことによって、スタンパ−のレ
プリカ面の凹部中からガスの逃げ易くなり、結果的に、
スタンパ−面上の凹凸状の信号またはトラック溝の転写
性が向上する。Effect According to the present invention, the depth of the uneven signal or track groove of the stamper is relatively deeper on the outer circumferential side than on the inner circumferential side of the stamper, so that gas is removed from the concave portion of the replica surface of the stamper. becomes easier to escape, and as a result,
The transferability of uneven signals or track grooves on the stamper surface is improved.
また、スタンパ−の厚みを内外周で変え、円周側の厚さ
に比べてその外周側の厚さが相対的に薄くしたことによ
って、樹脂の流れがさらに良くなり、得られたプラスチ
ック基板の特性がさらに向上する。In addition, by changing the thickness of the stamper between the inner and outer peripheries and making the outer periphery thinner than the circumferential thickness, the flow of the resin is improved, and the resulting plastic substrate is Characteristics are further improved.
本発明によって厚さおよび溝深さが不均一なスタンパ−
を用いて成形された樹脂基板は、驚くことに、樹脂基板
の厚さおよび溝深さが均一である。Stamper with non-uniform thickness and groove depth according to the present invention
Surprisingly, the resin substrate molded using the resin substrate has uniform thickness and groove depth.
これは、本発明のスタンパ−を用いることによって、金
型キャビティとスタンパ−との間隙が外周に向って広く
なり、しかもトラック溝の深さも内周から外周に向って
深くなっているため、溶融樹脂がスタンパ−のレプリカ
面の凹部内に流れ込む量が内周部と外周部とで均一にな
るためと考えられる。This is because by using the stamper of the present invention, the gap between the mold cavity and the stamper becomes wider toward the outer periphery, and the depth of the track groove also becomes deeper from the inner periphery toward the outer periphery. This is thought to be because the amount of resin flowing into the recesses of the replica surface of the stamper is uniform between the inner and outer circumferences.
以下、本発明を第１図を用いて説明する。The present invention will be explained below with reference to FIG.
第１図は本発明の一実施例におけるスタンパ−１０の概
念的断面図である。スタンパ−１０には一般に中心孔が
３が形成されている。FIG. 1 is a conceptual cross-sectional view of a stamper 10 in one embodiment of the present invention. The stamper 10 generally has a center hole 3 formed therein.
スタンパ−１Ｏの本体１４の厚さは内周部分１５から外
周部分１６に向けて次第に薄くなっている。具体的には
、スタンパ−１０の本体１４の最内周端部とその最外周
端部との厚さの差が約１０ミクロン薄くなっている。The thickness of the main body 14 of the stamper 1O gradually becomes thinner from the inner circumferential portion 15 toward the outer circumferential portion 16. Specifically, the difference in thickness between the innermost peripheral end and the outermost peripheral end of the main body 14 of the stamper 10 is approximately 10 microns thinner.
また、本発明によるスタンパ−１０では、スタンパの片
面に形成されている凹凸状の信号またはトラック溝の深
さが、内周部分１５から外周部分１６に向けて次第に深
くなっている。具体的には、スタンパ−１０の内周部分
１５の平均的な凹凸状の信号またはトラック溝１２の深
さと、その外周部分１６の凹凸状の信号またはトラック
溝１２の深さとの差が、例えば１００Ａ〜１５０人の範
囲になっている。Further, in the stamper 10 according to the present invention, the depth of the uneven signal or track groove formed on one side of the stamper gradually becomes deeper from the inner circumferential portion 15 toward the outer circumferential portion 16. Specifically, the difference between the average uneven signal or track groove 12 depth of the inner peripheral portion 15 of the stamper 10 and the uneven signal or track groove 12 depth of the outer peripheral portion 16 is, for example, The number ranges from 100A to 150 people.
この深さの差は内周部分１５から外周部分１６に向けて
連続的に変化しているのが好ましいが、−窓区域毎に不
連続的に変化していてもよい。This depth difference preferably varies continuously from the inner circumferential portion 15 to the outer circumferential portion 16, but it may also vary discontinuously from window area to window area.
次に、上言己のスタンパ−１０の製造方法を説明する。Next, a method of manufacturing the above-mentioned stamper 10 will be explained.
先ず、スタンパ−１０の凹凸信号およびトラック溝１２
の深さを内周部分１５から外周部分１６に向けて深くす
る手段としては下記の方法がある＝（１）ガラス原盤に
塗布するレジスト膜厚を内周から外周に向けて厚くする
方法、
（２） レーザカッティング用レーザーパワーを内周か
ら外周に向けて約５〜１０％大きくする方法。First, the unevenness signal of the stamper 10 and the track groove 12
The following methods can be used to increase the depth from the inner circumferential portion 15 to the outer circumferential portion 16: (1) A method of increasing the thickness of the resist film applied to the glass master from the inner circumference toward the outer circumference; 2) A method of increasing the laser power for laser cutting by about 5 to 10% from the inner circumference to the outer circumference.
一般には、例えばトラック溝の深さを内周部分１５で８
００人、外周部分１６で９００人〜９５０人の範囲に作
成すると良好な結果が得られる。Generally, for example, the depth of the track groove is set to 88 mm at the inner peripheral portion 15.
Good results can be obtained by creating a range of 00 people and a range of 900 to 950 people in the outer peripheral portion 16.
次に、スタンパ−１０の本体１５の厚さを内周部分１５
から外周部分１６に向けて次第に薄くする手段としては
、上記の特許公開公報に記載の方法を含めた以下の方法
がある：
（４）スタンパ−の電鋳（メツキ）工程において、内外
周でのメツキの厚さを変える方法、具体的には、所望の
面積を遮蔽する遮蔽リングを用いてスタンパ−の厚さに
放射方向に勾配を付ける方法
（５）通常の方法で作られたスタンパ−裏面を研磨する
工程で内外周部の研磨量を変えて、スタンパ−の厚みに
傾斜をつける方法。Next, the thickness of the main body 15 of the stamper 10 is determined by the inner peripheral portion 15.
As means for gradually thinning the outer circumferential portion 16, there are the following methods, including the method described in the above-mentioned patent publication: (4) In the electroforming (plating) process of the stamper, the inner and outer circumferences are A method of changing the thickness of the plating, specifically a method of radially gradating the thickness of the stamper using a shielding ring that shields a desired area. (5) Back side of a stamper made by a conventional method A method of creating a slope in the thickness of the stamper by changing the amount of polishing on the inner and outer peripheries during the polishing process.
実際には上記（１）または（２）の方法と（３）または
（４）の方法を組み合わせて用いる。Actually, the method (1) or (2) and the method (3) or (4) above are used in combination.
次に、本発明の一実施例を示す。Next, an embodiment of the present invention will be described.
実施例
スタンパ−１０の最内周端部とその最外周端部との厚さ
の差が約１０ミクロン薄くなっており、且つトラック溝
の深さを内周部分１５で８００人、外周部分１６で９０
０人〜９５０人の範囲にした厚みに傾斜を付けたスタン
パ−を用い、周知の光ディスク用射出成形機（２機製作
所製）を用いて、射出圧縮成形方法によって直径が３０
０φＩＩＩｍ、厚さがｌ、 ２ｍｍのポリカーボネート
（ＰＣ）樹脂基板を射出成形した。The difference in thickness between the innermost peripheral end and the outermost peripheral end of the stamper 10 of the embodiment is approximately 10 microns thinner, and the depth of the track grooves is 800 mm in the inner peripheral part 15 and 800 in the outer peripheral part 16. So 90
Using a stamper with a sloped thickness ranging from 0 to 950 mm, a well-known injection molding machine for optical discs (manufactured by Niki Seisakusho) was used to mold a diameter of 30 mm by injection compression molding.
A polycarbonate (PC) resin substrate with a diameter of 0φIIIm and a thickness of 1 and 2 mm was injection molded.
成形によって得られた（Ｐ Ｃ）樹脂基板は、内外周の
厚さが均一であり、しかも、および内外周のトラック溝
の深さも均一であった。The (PC) resin substrate obtained by molding had a uniform thickness on the inner and outer peripheries, and also a uniform depth of the track grooves on the inner and outer peripheries.
発明の効果
以上の説明から明らかなように、本発明によるスタンパ
−を用いて射出成形または射出圧縮成形によってプラス
チック基板を成形した場合には、ガスの逃げが良くなり
、樹脂の流れが良くなり、金型キャビティ側とスタンパ
−側とで樹脂の流れの速さに差が無くなり、内周部と外
周部とてレプリカの凹部中に流れ込む樹脂の量に差が無
くなり、成形された樹脂基板の寸法安定性と、形状安定
性、転写性が向上し、しかも、光学的特性も向上する。Effects of the Invention As is clear from the above explanation, when a plastic substrate is molded by injection molding or injection compression molding using the stamper according to the present invention, gas escape is improved, resin flow is improved, There is no difference in the speed of resin flow between the mold cavity side and the stamper side, and there is no difference in the amount of resin flowing into the recess of the replica between the inner and outer periphery, and the dimensions of the molded resin substrate are reduced. Stability, shape stability, and transferability are improved, and optical properties are also improved.
従って、本発明のプラスチック基板を用いて作られた光
ディスクは記録・再生特性に優れたものとなる。Therefore, an optical disc made using the plastic substrate of the present invention has excellent recording and reproducing characteristics.
本発明は特に、大径の樹脂基板を成形する場合または多
量のプラスチックディスクを高サイクルで成形する場合
に極めて有利である。The present invention is particularly advantageous when molding large-diameter resin substrates or when molding a large number of plastic disks at high cycles.
（主な参照番号）
ｌＯ゛スタンパ−
１２ニスタンパ−上の凹凸状の信号ピントまたはトラッ
ク溝(Main reference number) 1O゛ Stamper 12 Uneven signal focus or track groove on the stamper
Claims (1)
成形する際に用いられる片面に凹凸状の信号またはトラ
ック溝を有するスタンパーにおいて、スタンパーの厚さ
が内周側に比べて外周側が相対的に薄くなっており、且
つ、上記の凹凸状の信号またはトラック溝の深さがスタ
ンパーの内周側に比べてその外周側が相対的に深くなっ
ていることを特徴とするスタンパー。In a stamper having an uneven signal or track groove on one side, which is used when molding a plastic substrate for an optical disk by injection molding, the thickness of the stamper is relatively thinner on the outer circumferential side than on the inner circumferential side, Further, a stamper characterized in that the depth of the uneven signal or track groove is relatively deeper on the outer circumference side than on the inner circumference side of the stamper.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9813790A JP2707501B2 (en) | 1990-04-13 | 1990-04-13 | Injection molding stamper |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9813790A JP2707501B2 (en) | 1990-04-13 | 1990-04-13 | Injection molding stamper |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH03295041A true JPH03295041A (en) | 1991-12-26 |
| JP2707501B2 JP2707501B2 (en) | 1998-01-28 |
Family
ID=14211847
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP9813790A Expired - Lifetime JP2707501B2 (en) | 1990-04-13 | 1990-04-13 | Injection molding stamper |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2707501B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1211040A2 (en) * | 1999-02-09 | 2002-06-05 | Ricoh Company, Ltd. | Optical disk and method of producing the same |
| JP2002184038A (en) * | 2000-10-05 | 2002-06-28 | Ricoh Co Ltd | Optical recording medium |
| US8841588B2 (en) | 2009-03-27 | 2014-09-23 | Tsinghua University | Heater |
-
1990
- 1990-04-13 JP JP9813790A patent/JP2707501B2/en not_active Expired - Lifetime
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1211040A2 (en) * | 1999-02-09 | 2002-06-05 | Ricoh Company, Ltd. | Optical disk and method of producing the same |
| EP1211040A3 (en) * | 1999-02-09 | 2002-08-07 | Ricoh Company, Ltd. | Optical disk and method of producing the same |
| US6686018B2 (en) | 1999-02-09 | 2004-02-03 | Ricoh Company, Ltd. | Optical disk and method of producing the same |
| US6998163B2 (en) | 1999-02-09 | 2006-02-14 | Ricoh Company, Ltd. | Optical disk and method of producing the same |
| US7419710B2 (en) | 1999-02-09 | 2008-09-02 | Ricoh Company, Ltd. | Stamper for molding article and method of producing said stamper |
| JP2002184038A (en) * | 2000-10-05 | 2002-06-28 | Ricoh Co Ltd | Optical recording medium |
| US8841588B2 (en) | 2009-03-27 | 2014-09-23 | Tsinghua University | Heater |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2707501B2 (en) | 1998-01-28 |
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