JPS6141527A - Method and device for transferring relief structure to substrate - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for transferring relief structures to a substrate and an apparatus for carrying out this method.

[Conventional technology]

A curable liquid is applied between the substrate and the mold surface having holes or convex portions corresponding to the negative shape of the relief to be transferred, and then the mold surface and the substrate are at least partially pressed together, thereby Each section of the mold surface moves only in the direction perpendicular to the contact surface with respect to the substrate, and then the curing liquid hardens, but during this process, the mold surface and the substrate do not move relative to each other, and both of them remain in the initial position. The substrate remains pressed at a pressure lower than the pressure in the pressing stage, and the substrate and mold surface are separated after the liquid hardens.

This type of method is described, for example, in U.S. Pat. No. 3,265.
It is described in No. 776. In this known method, a web-shaped die is used which is pressed onto a substrate coated with a hardening liquid using a roller. Thereafter, the pressed substrate and die are wound around a reel, and the liquid is cured within a scheduled time. Thereafter, the substrate, to which the at least partially hardened liquid layer has been deposited, is removed from the mold surface.

[Problem that the invention seeks to solve]

This method presents problems, particularly when removing the substrate to which the cured liquid layer is attached from the die. In order to transfer the relief structure of the die well, a liquid layer must be poured between the die and the substrate, which are pressed together and brought into close contact with each other.

However, as a result, when the substrate to which the cured liquid layer in the form of a relief adheres is peeled off from the die, some of this cured liquid layer remains on the die, or some of the relief structures of the die are removed. It may peel off along with the hardened liquid layer.

Not only does the quality of the transfer and the mold surface deteriorate, but the quality of the subsequent transfer is also extremely adversely affected, and furthermore the life of the mold surface is shortened.

This problem plays an increasingly important role the smaller the dimensions of the relief structure become. Particularly in microstructures where the relief depth and/or specific resolution is up to 100μ and even in special cases down to 1 micron, the precision of the imprint and the die may be compromised if the imprint is not accurately removed from the die. The lifespan of the product will be significantly reduced. Examples of surfaces with structures of this type are spectroscopic measurement gratings, flat lenses such as Fresnel lenses, LP records, optical audio and video discs, digital optical tapes, etc.

The above US patent only states that the transfer is to be peeled off from the die before the layer of hardening liquid adheres to the mold surface. However, this is because the liquid layer that is not completely cured is easily damaged, and when it is cured afterwards, it deforms (shrinks).
However, there is a disadvantage.

Dutch patent application No. 78.11395 describes a similar method of discontinuous transfer from a mold surface. A liquid resin that hardens with light is attached to the mold surface,
Cover with a transparent substrate to allow light to pass through. The resin in the missing number is cured by the light that comes through the board,
After curing, the finished transfer is removed from the die. In this application, the combination of a metal mold surface, a resin of a specific composition that is cured by light, and a transparent substrate that is transparent to the light is absolutely necessary. It is clear that this problem is not completely solved using this combination.

European Patent Application No. 0.015.834 describes a similar method for manufacturing video discs.

This application states that the resin does not need to adhere to the die, and that it is better to use a metal mold surface. However, a final solution to the problem of peeling off the transcript is not described.

It is an object of the present invention to present an improved method for stripping the resulting transfer and the corresponding accuracy of the transfer and for extending the life of the die.

[Effect]

According to the present invention, the relief structure can be well transferred by the method described at the beginning when there are significant differences in the chemical or physical parameters that affect the hardening process between the high and low parts of the relief, Moreover, the life of the mold surface can be extended. The parameters mentioned here are, for example, the thickness of the respective liquid portion, the temperature, or the chemical composition or, in the case of liquids that are cured by light, the intensity of the light beam. Preferably, different chemical or physical parameters of each fluid portion will affect the rate of cure of each fluid portion.

For example, in order to achieve good transfer quality and extend the life of the mold surface, the thickness of the liquid part forming the higher relief part should be at least 50% greater than the thickness of the liquid part forming the lower relief part. It is known that this is the case. This is surprising. This is because in order to obtain widely different thicknesses, especially in the case of microstructures, relatively large pressures must be applied to the mold surface. It can be inferred from experiments that there is a pressure per millimeter of the mold surface that is several hundred to several thousand times the atmospheric pressure and a pressure gradient that is several hundred to several thousand times the atmospheric pressure. It is therefore not surprising that in the known methods and apparatuses for producing microscopic relief structures, there are no significant differences in these high pressures and the resulting thickness of the liquid layer in which the relief structures are formed. As mentioned above, in particular the difference in thickness is at least 50%;
Preferably, the difference is 100%. If the height of the relief is, for example, 0.2 microns, a measurement commonly used for optically readable discs, a difference in thickness of 50% means that the thinner part of the relief layer is less than 0.1 micron. It must not be thick, meaning that the highest part of the relief must not be more than 0.3 microns thick.

The reason why the difference in thickness increases transfer accuracy and extends the life of the die is that this difference in thickness creates a large ratio difference between the surface of the liquid part and the volume. This means that there may be large differences in cure speed.

The contraction of the liquid during curing can be explained as follows. If the difference in thickness between the thick and thin portions of the liquid portion becomes larger, the thicker portion may shrink, but this contraction will not be replaced by liquid from the thinner portion. In such cases, the thick liquid portion becomes able to be peeled off the mold surface during curing. This peeling explains why the transfer accuracy is high and the life of the die is extended.

According to a preferred method, it is particularly important that the concentration of one of the chemical constituents, which determines the curing rate of the liquid, such as the catalyst or the photoinitiator, is at least 50% or higher in one of the liquid parts.

Experiments have shown that the concentration of the relevant chemical constituents is preferably higher the thicker the liquid section. In this case, it is clear that the difference in curing speed is an important factor that plays a major role in improving transfer accuracy and extending the life of the mold surface.

Moreover, in this case the hardening liquid adheres faster and better to the substrate than to the mold surface. This advantage also applies to other methods within the scope of the invention. Improving adhesion to the substrate by pretreating the surface of the substrate by corona discharge, etching, coating the surface with a film made of an adhesion promoter, or subjecting the surface to an ion implantation treatment. I would like to draw attention to what I can do.

Additionally, the use of polymer fluids that harden upon exposure to UV light, such as mixtures of oligomeric methacrylates, can extend die life and improve transfer accuracy if the UV light intensity is greater in some portions of the fluid. It seems to be the case.

Here, "greater than" means that the concentration of the curing electromagnetic radiation is at least 50% or more in each liquid portion.

Experiments have shown that the intensity of the light beam is preferably higher in the above sense in those liquid parts forming the relief cross section.

In other cases, the temperature difference between thick and thin parts has the same positive effect, making thermosets warmer in thin parts and thermoplastics being warmer in thick parts. It has been found that warmer areas are preferable.

Creating a physical or chemical difference between thick and thin liquid portions is not so simple. This is especially true when the difference in height of the relief structure to be transferred is extremely small, from 100 microns or less to 1 micron or less, and the spatial resolution is also the same as above.

However, this region of 100 microns or less to 1 micron or less is particularly targeted by the present invention.

According to a preferred method, a curing liquid is deposited between the mold surface and the substrate, by first depositing a first liquid on the substrate and a second liquid on the mold surface, thereby causing chemical or physical damage to the two liquids. The target parameters are different from each other.

Further preferred embodiments of the method according to the invention and details of the apparatus for carrying out the method will now be described in conjunction with the accompanying drawings.

〔Example〕

In the device according to the invention shown in Figure 1, a substrate in the form of a tape or web 1 is fed to a roller 2, which presses it strongly against a die roll 3 having a mold surface to be transferred. Ru.

It has been found that the force required for this process varies depending on the following process parameters: Namely, the width of the roll, the viscosity of the hardening fluid, the speed of the web u, the radii of the two pressure rollers r1 and r2. The hardness of the roller surface and the hardness of the web material.

The surface of the roller is hard and the web material is as thin as 12 micron thick Mylar film (trade name of DuPont).
If it is hard, the force r is 4 X 10' X bX h X
Experiments have shown that it is larger than u x r.

The radius r is according to the equation 1/r = 1/rl + 1/r2. Dimensions are expressed in meters (KVrrV/ri).

The viscosity of the fluid is high shear rate, especially 10'
Must be measured at rV/sec or higher.

When the rollers are coated with rubber or when using thicker films such as polycarbonate films with a thickness of between 1 and 1, the required roller force is significantly higher, i.e. more than 10 times that calculated according to the above formula. I know it has to be expensive.

In the apparatus according to FIG. 1, both surfaces of the substrate and die are moistened with a curable fluid by wetting means (not shown) before the substrate and die are pressed together. The wetting means are known, for example a roll rotating in the opposite direction of the movement of the surface to be moistened, an elongated spout covering the width of the surface to be moistened, or a sump in a roller nip. It may be.

In the apparatus according to FIG. 1, a curing liquid is applied between the surface of a rotating die and a substrate tape wrapped around a die roller. The mold surface shown in Figure 1 is transparent for ultraviolet rays, and the liquid is cured by the ultraviolet rays emitted from the light source 4, but since this ultraviolet ray is reflected by the reflector 5 on the upper side, the pressure rolls 2 and 6 The ultraviolet rays only hit the part of the mold surface between the molds. Both the light source 4 and the reflector 5 are mounted in fixed positions within the rotating die roll 3.

After curing, the substrate is removed from the mold surface, with some adhesion and carrying the structure of the cured relief, and transported further through the pressure rolls 6. Die roll 3, press roll 2
and 6, a light source 4, a reflector 5, etc. are connected to a support frame 9.

In this device, two liquid supply means are used to apply the liquid to the respective surfaces of the substrate and die at around 7 and 8, thereby creating a thick chemical composition in the liquid part that is different from a thin composition in the liquid part. , whereby the thickness of each of said liquid layers is greater than the thickness of the relief structure to be transferred.

In such cases, by sandwiching two thin liquid layers together between the pressure roll 2 and the die roll 3 of the nip, a thin liquid layer (11! A large amount of liquid composition is applied to another surface,
That is, a relatively large amount of another liquid composition will be deposited near the mold surface. Experience has shown that the thicker part of the liquid layer in the form of a relief consists of a relatively large amount of the composition supplied to the mold side. If the difference in thickness between the thin liquid portion and the thick liquid portion is relatively large, the difference is significant. Using a plurality of liquids having low and almost uniform viscosity, the pressure roller 2 is applied to the surface 3 of the die roll with a large force according to the above formula.
It is preferable to press the

Examples of suitable liquids include TPGDA 50% by weight, 0TA48Q 444% by weight, DMPA 5% by weight on the substrate surface.
, and the mold surface was coated with 50% TPGDA and OTA.
It is a mixed liquid of 48050% by weight. The viscosity of these mixtures is approximately 75 CP at a shear rate of 101.

TGDDA 0TA480 is a trade name of Union Shimitsuku Perche Co., Ltd., and its chemical composition is tripropylene glycol diacrylate (tripropylene glycol diacrylate).
gly-coldiacrylate) and has a molecular weight of approximately 4.
80 oligotriacrylic L/-) (oligotr
iacrylate). The chemical composition of DMPA is 1
, 1-dimethoxy-1-vinyl-acetophenone (1
,1-dimethoxyl --vinyl-ace
topbenone).

Another common mixture of acrylic monomers and oligomers that can be used is N-vinyl-2-biCIU:
/ (N-vinyl-2-pyrol 1done
), benzyl acrylate
(late), Tetrahuman 07 /L/7 Ryl Acrylic L
/ -1-(tetrahydro[urf-iryl
Acryl atsu or Laronam AR-8496, a product of RASF + VP 5270 commercialized by Degusa
Trimethylpropane triac +) L/- like 0
(trimethylpropane-triacr)
ylate). Apart from acrylates, other curable polymers such as epoxy resins, polyacrylate silicones may also be used.

The mold substrate of the device according to FIG. 1 is transparent to allow the passage of ultraviolet radiation from the light source 4. The protrusions of the relief structure that stand out from the actual mold surface are preferably made of an opaque material that does not transmit ultraviolet light.

Suitable materials for these raised areas on the mold surface include chromium, titanium, and chalcogenide.
There are several types of glass, such as cogenide glass. The material of the mold surface itself may be quartz-1 fused silica or thin plexiglass, so that the surface structure is supported inwardly by an auxiliary structure forming part of the rotatable roller body.

Such a relief structure is shown briefly in FIG. In this figure, reference number 21 indicates a transparent roller surface,
22a, 22b, 22C refer to the UV opaque parts of the relief structure. 23 is a curable liquid layer;
24 is a substrate. In this arrangement, the ultraviolet light 25 acts only on the thick part of the liquid film. First, after chemical diffusion, parts of the liquid film that are masked to avoid direct radiation are cured.

In the case of a liquid film that exhibits shrinkage during curing, such as the composition described above, it has been found that the thinner parts of the liquid film are partially channeled into the thicker parts of the film that are curing more quickly.

Since this happens again and again, this shrinkage can be taken into account when creating relief structures on the mold surface.

The apparatus of Figure 1 can also be used with thermoplastic fluids.

This liquid, in fluid form, precipitates or is present on the substrate surface and/or mold surface, and is also present on the first pressure roll 2.
It cools and hardens while being transferred from the to the second press roll 6. In this case, the transfer accuracy will be high, and if the mold surface 21 is relatively cool and thermally conductive, mold wear will be reduced, for example because the mold is made of metal (in this case, the mold surface is transparent to ultraviolet light). The raised portions 22a, 22b, 22C, . . . of the relief structure are made of a thermally insulating material such as plastic, such as Teflon, or glass, for example.

The apparatus is capable of processing both organic thermoplastics such as polyvinyl chloride and polyamides, and inorganic thermoplastics such as solder types such as tin-lead half-metal or lead-cadmium solders. Conductive inorganic thermoplastics can be advantageously used to fabricate electrical conductors into flexible printed circuit boards used in the microelectronic industry.

In the apparatus of FIG. 1, the required relief structures are successively realized on a web of substrate or tape.

Rectangular or circular sections can be cut or punched out of these tapes or webs and these sections can be used, for example, as (flexible) printed boards or (flexible) video discs.

The method of the invention can also be used in discontinuous processing. In this case, it has been found to be advantageous for the present device to bring the substrate into line contact with the mold surface, followed by surface contact during the curing step. High pressure can be applied to the line contact surface, which has proven advantageous in increasing the difference in thickness between the thin and thick parts of the relief.

It proves advantageous not to apply such high pressures during the actual curing process. The overpressure at that time is 100.0
It is desirable that the pressure is OOPa or less, and in special cases it is 1000 Pa or less.

In the continuous processing process explained in connection with Fig. 1,
During the curing step, the curved tension within the substrate tape is used to press the substrate against the mold surface. This bending tensile force is 1000Pa
J: Existing in normal substrate materials, the pressure is small and even significantly smaller than the maximum pressure in the nip between the pressure roller 2 and the die roller surface 3.

Examples of suitable materials include polyethene terephtha L/
-) (polythene terephthal
ate, DuPont mylar) + polyimide (pol
yimide, DuPont Kapton), polymethylmethacrylate (polymethylmethacrylate)
rylate, all of which are in some cases metallized), and also aluminum.

There are straps such as titanium or stainless steel straps. The substrate strip consists of several layers, which can be divided, for example, into a structural carrier and a mechanical support layer.

The method of the invention can also be used to create relief structures on band-shaped dies. An apparatus for carrying out this method is shown in FIG.

Carrier band 3 that supports the relief to be transferred
1 is supplied to a roller 33 (here, a smooth roller) via a pressure roller 32. The die band 40 is the roller 4
It is supplied to the roller 33 via 1, separated from the roller 33, and wound up via the roller 42. Liquid supply means 37 and 38 wet the surfaces of carrier 41 and die 40 with liquid.

In this embodiment, as in FIG. 1, a liquid that is cured by light may be used, and in this case, the light source 34 and reflector 35 are mounted below the support frame 39.

In this case, at least a portion of both the die band and the roller 33 must be made transparent to transmit ultraviolet rays, as described in FIG. 2.

The curing liquid can be applied in the same way as the temperature curing liquid in FIG. 1, or in a different manner, in which case the die band and thus the roller 33 can be used in the same manner as described with reference to FIG. .

The die and substrate are separated near rollers 36, where the substrate is removed from the die. Then the die is moved to roller 4
2 to a take-up reel (not shown).

〔effect〕

Akira Himi's methods and equipment include a flexible printed board single diffraction grating, a grating lens, and a Fresnel lens.

LP records, compact discs, video discs,
It is used to implement relief structures for products such as positive and digital optical tapes with so-called zero-order grating diameters.

These products differ significantly from similar products made using other methods and equipment in the relief characteristics, which include thinner and thicker areas. These differences include significant thickness differences, catalysts,
Differences in concentration of optical initiator, internal mold release agent, solvent, filling fluid, etc. 1Difference in degree of polymerization or difference in polymerization form,
These include differences in the degree of crystallization or differences in crystal form.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a first embodiment of the device according to the present invention, FIG. 2 is a cross-sectional view of a die, a liquid layer, and a substrate stacked together, and FIG. 3 is a diagram showing a second embodiment of the device according to the present invention. be. 1... Board, 2... Roller, 3... Die roller,
4...Light source, 5...Reflector, 6...Press roller Patent applicant Dokudata N.V.A. Agent
Sickle 1) Sentence 2 "H Procedural Amendment (Juri November 30, 1981 Patent Application No. 163464 2, Title of Invention (New) Method and Apparatus for Transferring a Relief Structure onto a Substrate (Old) Relief Relationship between the method and device for transferring a structure onto a substrate 3 and the case of the person making the amendment Patent applicant name (name) Dokudata E8 Vue Showa
Year, month, day (shipment date) 6, Number of inventions increased by amendment Contents of amendment 1. The name of the invention of the present application is corrected to "Method and apparatus for transferring a relief structure to a substrate" 02 Full text of the specification as attached. will be corrected. Description 1, Name of the invention Method and apparatus for transferring a relief structure onto a substrate 2, Claims (1) A mold surface provided with holes or protrusions corresponding to the negative shape of the relief to be transferred, and a substrate. the mold surface and the substrate do not move in any direction other than perpendicular to its contact surface, and then the curing liquid cures, with no reciprocal movement between the mold surface and the substrate, both of which In a method of transferring a relief structure to a substrate, which consists of keeping the substrate pressed at a pressure lower than the pressure at the initial pressing stage and separating the substrate and mold surface after the liquid hardens, the liquid part forming the high relief part and the mold surface are separated. A method for transferring a relief structure to a substrate, characterized in that there is a significant difference in chemical or physical parameters that affect the curing process between the liquid part forming the low relief part and the liquid part forming the low relief part. (2) A method for transferring a relief structure to a substrate according to claim 1, characterized in that these widely different chemical or physical parameters influence the curing speed of the liquid. (3) The pressure exerted when the two surfaces are pressed against each other causes the thickness of the liquid part forming the high relief part to be considerably greater than the thickness of the liquid part forming the low relief part;
943. A method for transferring a relief structure to a substrate according to claim 1 or 942, characterized in that the pressure is sufficiently high, especially at least 50%. (4) The substrate and the mold surface press against each other along a line of contact and thereafter remain in contact, so that the pressure at the line contact is at least 10 times greater than the pressure at the contact state. A method of transferring a relief structure according to any one of the first to third aspects to a substrate. (5) The pressure required to press the substrate mold surface against each other is 4 x 10' x b x h x u x r or more, where b is the width of both sides and h is the viscosity of the curing liquid. , U is the velocity of the substrate, r follows the equation 1/r=1/r1+1/r2, and rl and r2 are the respective bending radii of the substrate and mold surface at the location of the contact line on the inlet side. A method of transferring a relief structure according to claim 4 to a substrate. (6) A method for transferring a relief structure to a substrate according to any one of claims 1 to 5, wherein the difference in height of the relief structure is less than 100 microns. (7) A method for transferring a relief structure to a substrate according to claim 6, wherein the difference in height is 1 micron or less. ! (8) A patent characterized in that in one of the liquid parts, the concentration of one of the chemical components determining the curing rate of the liquid, such as a catalyst or a photoinitiator, is considerably high, in particular at least 50% or more. □Claims □Claims 1 to 7
A method of transferring the relief structure according to any of the above to a substrate. (9) Transferring the relief structure according to claim 4 to a substrate, characterized in that the concentration is considerably higher in the fluid part forming the higher relief part, in particular at least 50% or more. Method. 10) By depositing a layer of the first liquid on the substrate and a layer of the second liquid on the mold surface, the curing liquid is deposited between the mold surface and the substrate, thereby causing chemical or physical damage to both liquid layers. A method for transferring a relief structure to a substrate according to any one of claims 1 to 9, characterized in that the physical parameters are different from each other. (11) The liquid is cured under the action of electromagnetic radiation, the intensity of which is considerably high in one of the liquid parts, in particular at least 50% or more.
A method for transferring the relief structure according to any one of items 1 to 10 onto a substrate. Q2+ A method for transferring a relief structure onto a substrate according to claim 6, characterized in that in the method, the light beam intensity is stronger in those liquid parts forming the higher relief parts. Q31 The liquid is a thermosetting liquid and the lower IJ
- The relief structure according to any one of claims 1 to 6, wherein the temperature of the liquid forming the relief part is higher than the temperature of the liquid part forming the higher relief part. How to transfer onto a substrate. 7. A method for transferring a relief structure onto a substrate according to any one of claims 1 to 6, characterized in that the temperature is lower than the temperature of the liquid portion forming the part. L151 A method for transferring a relief structure to a substrate according to any one of claims 1 to 14, characterized in that the relief structure has a spatial resolution of less than 100 microns. (161) A method for transferring a relief structure to a substrate according to claim 14, characterized in that the spatial resolution is less than 1 micron. In an apparatus for transferring a relief structure onto a substrate, the apparatus includes a transfer unit that holds the substrate in a pressed state between the two, a means for supplying the substrate to the transfer unit, and a means for applying a hardening liquid. a first liquid supply means for applying the liquid to the substrate;
An apparatus for transferring a relief structure onto a substrate, characterized by comprising a second liquid supply means for applying a thin liquid layer to the mold surface. It is characterized by being transparent to electromagnetic light having a wavelength between 2,000 nanometers and 2,000 nanometers, and the protruding portion of the relief structure to the mold surface has a considerably low transmittance to the electromagnetic light, particularly at least 50% or less. An apparatus for transferring a relief structure to a substrate according to claim 17, wherein the α (support) surface is made of a good thermal conductor, for example a metal such as copper, aluminum or steel, The relief structure according to claim 17, characterized in that the protruding portion of the mold surface of the relief structure has considerably low thermal conductivity when made of non-metallic material such as plastic or non-metallic glass. (4) The physical or chemical parameters and properties of the high relief part are significantly different from the parameters and properties of the low relief part, for example the thickness is significantly different. A carrier having a relief structure incorporated in the method or apparatus according to any of paragraphs 1 to 19. (21) The physical or chemical parameters and properties of the high relief part are comparable to those of the low relief part. Claim 1 characterized in that there is a significant difference, for example in the concentration of the catalyst or reaction initiator, in the crystal structure or degree of crystallinity, in the polymerization structure or degree of polymerization.
Items 20 to 20. A carrier having a relief structure incorporated into a method or apparatus according to any of the claims. 3. Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a method for transferring a relief structure to a substrate and an apparatus for carrying out the method. [Prior art] In the conventional method of transferring a relief structure to a substrate, a curing liquid is deposited between the substrate and the surface of a mold having holes or convex portions corresponding to the negative shape of the relief to be transferred, and then the mold is removed. The surface and the substrate are at least locally pressed together so that each part of the mold surface cannot move relative to the substrate in any direction other than perpendicular to its contact surface, and then the curing liquid cures, while There was no mutual movement between the mold surface and the substrate, and both remained pressed together with a pressure lower than the pressure at the initial pressing stage, and the substrate and mold surface were separated after liquid curing. This type of method is illustrated in US Pat. No. 3,265.
It is described in No. 776. This known method uses a web-like mold which is pressed using rollers onto a substrate coated with a curable liquid. Thereafter, the pressed substrate and mold are wound around a reel, and the liquid is cured within a scheduled time. The substrate with the at least partially hardened liquid layer is then removed from the mold surface. [Problems to be Solved by the Invention] This method poses a problem, particularly when the substrate to which the cured liquid layer is attached is to be peeled off from the mold. In order to successfully transfer the IJ-F structure of the mold, a liquid layer must be poured between the mold and the substrate, which are pressed together and brought into close contact. However, as a result, when the substrate to which the cured liquid layer in the form of a relief is attached is removed from the mold, a part of this cured liquid layer remains on the mold, or a part of the relief structure of the mold is hardened. It may peel off along with the liquid layer. Not only does the quality of the transfer and the quality of the mold surface deteriorate, but the quality of subsequent transfers is also extremely adversely affected, and the life of the mold surface is also shortened. This problem plays an increasingly important role the smaller the dimensions of the relief structure become. In particular, the relief depth and/or specific resolution is 1o. For microstructures smaller than microns, especially smaller than 1 micron, if the transferred material is not accurately removed from the mold, the accuracy of the transfer and the life of the mold will be significantly reduced. Examples of surfaces with structures of this type are spectroscopic measurement gratings, flat lenses such as Fresnel lenses, LP records, optical audio and video discs, digital optical tapes, etc. The US patent only states that the transfer should be removed from the mold before the layer of hardening liquid adheres too tightly to the mold surface. However, this has the disadvantage that the liquid layer, which is not fully cured, is easily damaged and deforms (shrinks) during subsequent curing. Dutch patent application No. 78.11395 describes a similar method used for discontinuous transfer from a mold surface. A liquid resin that is cured by light is applied to the mold surface and covered with a transparent substrate to allow the light to pass through. This resin is then cured by the action of light beams entering through the substrate, and after curing the resulting transfer is removed from the mold. In this application, the combination of a metal mold surface, a resin of a specific composition that is cured by light, and a transparent substrate that is transparent to the light is absolutely necessary. It is also clear that this problem is not completely solved in all cases using this combination. A similar method for manufacturing video discs is also described in European patent application no. o, 01 s, s 34. This application discusses that the resin does not have to adhere to the mold, and further states that it is better to use a metal mold surface. However, a final solution to the problem of peeling off the transcript is not described. The purpose of the invention is to show how the resulting transfer can be removed and the accuracy of the transfer correspondingly improved and the lifetime of the mold can be extended. [Means for solving the problems] In order to solve the above problems, the transfer method according to the present invention includes:
It is characterized by a significant difference in the chemical or physical paranata which influences the hardening process between the liquid part forming the high relief area and the liquid part forming the low relief area, respectively. Further, the transfer device according to the present invention is characterized in that it includes a first liquid supply means for applying a thin liquid layer to a substrate, and a second liquid supply means for applying a thin liquid layer to a mold surface. [Operation] According to the present invention, if there is a significant difference between the high and low liquid parts of the relief in terms of chemical or physical parameters that affect the hardening process, the relief structure is cured by the method described at the beginning. can be transferred well and at the same time extend the life of the mold surface. The parameters mentioned here are, for example, the thickness of the respective liquid portion, the temperature, or the chemical composition or, in the case of liquids that are cured by light, the intensity of the light beam. Preferably, significant differences in the chemical or physical parameters of each liquid portion affect the rate of cure of each liquid portion. For example, it has been found that when the thickness of the liquid part forming the higher relief part is greater than the thickness of the liquid part forming the lower relief part, especially at least 50%, long life and good quality transfer can be achieved. It was. This is surprising. This is because in transfers with large differences in thickness,
This is because a relatively large pressure must be applied to the mold surface, especially in the case of minute relief structures. According to experiments, the pressure on the mold surface is several hundred to several thousand times higher than atmospheric pressure.
A pressure gradient of hundreds to thousands of times the atmospheric pressure can be obtained per millimeter. It is therefore not surprising that known methods and devices for producing micro-relief structures avoid these high pressures and the resulting large differences in the thickness of the liquid layer in which the relief structures are formed. . As mentioned above, in particular the difference in thickness is at least 50%, preferably 10%.
A difference of 0% is preferred. If the height of the relief is, for example, 0.2 microns, which is the measurement normally used for optically readable discs, a difference in thickness of 50% means that the thinner part of the relief layer is less than O,X microns. It must not be too thick, and the highest part of the relief must be 0.
This means that it should not be higher than 3 microns. The reason why the difference in thickness improves transfer accuracy and extends the life of the mold is that this difference in thickness creates a large difference in the ratio of surface area to volume of the liquid part, which has a large effect on the curing speed. This means that it will make a difference. The contraction of the liquid during curing can be explained as follows. If the difference in thickness between the thick and thin parts of the liquid section becomes larger, the thicker part in particular will shrink, and this contracted liquid part will not be replenished with liquid from the thinner part. In such cases, the thick liquid portion becomes able to be peeled off the mold surface during curing. This peeling is the reason for improving transfer accuracy and extending mold life. According to a preferred method, the concentration of one of the chemical components determining the curing rate of the liquid, such as a catalyst or a photoinitiator, is considerably high, especially in one of the liquid parts;
It is important that it is at least 50% higher. Experiments have shown that the concentration of the relevant chemical constituents is preferably higher in the thicker liquid portion. In this case, it is clear that the difference in curing speed is an important factor that plays a major role in improving transfer accuracy and extending the life of the mold surface. Moreover, in this case the hardening liquid adheres faster and better to the substrate than to the mold surface. This advantage also applies to other possible methods within the scope of the invention. Pretreat or etch the substrate surface by corona discharge,
Cover the surface with a film made of an adhesion promoter, or
It is noted that the surface may alternatively be subjected to an ion implantation treatment to improve adhesion to this substrate. Furthermore, in polymer liquids that harden under the action of ultraviolet light, such as mixtures of oligomeric methacrylates, mold life may be extended and transfer accuracy may be improved if the intensity of the ultraviolet light is considerably greater than in one of said liquid parts. It seems to me. Here, "considerably greater than 1" means that the intensity of the electromagnetic light for curing is at least 50% stronger in each liquid part.The intensity of the light rays forms a higher relief cross section in the above sense. Experiments have shown that it is preferable to be stronger in these liquid parts.In other cases, the temperature difference between thick and thin liquid parts has the same positive effect, so It has been found that it is preferable for thermoplastic liquids to be warmer in thinner parts, and for thermoplastic liquids to be warmer in thicker parts.There are physical or chemical differences between thick and thin parts. It is not so easy to generate this.If the difference in height of the relief structures to be transferred is extremely small, less than 100 microns, each of which is less than 1 micron, and the spatial resolution is also on the same order. However, this region of less than 100 microns, each of less than 1 micron, is particularly targeted by the present invention. According to a preferred method, the curing liquid is deposited between the mold surface and the substrate, but first Another preferred embodiment of the method according to the invention is that the first liquid is applied to the substrate and the second liquid is applied to the mold surface, so that the chemical or physical parameters of the two liquids differ from each other. Details of an apparatus for carrying out the method will be described in detail below with reference to the accompanying drawings.Example: In the apparatus according to the invention shown in FIG. 2, and the substrate is strongly pressed by roller 2 against mold roller 3, which has the mold surface to be transferred.It has been found that the force required for this process varies depending on the following process parameters: , roller width, viscosity of the hardening fluid, web speed u, radius r1 and r2 of the two pressure rollers, hardness of the roller surface and hardness of the web material.The roller surface is hard and the web material is 12 microns thick. It's thin like Sano Mylar film (DuPont's trademark name),
If it is hard, the force f is 4 x 10' x bxhxux
Experiments have shown that it is larger than r. The radius r is the equation 1/r = l/r 1 + l/r 2
by. Dimensions are in metric units (K9/m/
8). The viscosity of the fluid must be measured at high shear rates, especially at reciprocal seconds of 106X u (dimension in metric units) or higher. When the rollers are coated with rubber or when using thicker films such as polycarbonate films with a thickness of 1 mm, the required roller force is significantly higher, i.e. more than 10 times higher than calculated according to the above formula. I know it has to be something. In the apparatus according to FIG. 1, the substrate and mold are moistened with a curable fluid by wetting means (not shown) before they are pressed together. The wetting means may be of any known type, for example rollers rotating in the opposite direction to the movement of the surface to be moistened;
It may be an elongated spout covering the width of the surface to be wetted, or a roller nip sump. In the apparatus according to FIG. 1, the curing liquid is applied between the rotating mold surface and the substrate tape wrapped around the mold roller. The surface of the mold shown in FIG. 1 is transparent for ultraviolet rays, and the liquid is cured by the ultraviolet rays emitted from the light source 4, but since this ultraviolet ray is reflected by the reflector 5 on the upper side, the pressure rollers 2 and 6 The ultraviolet rays only hit the part of the mold surface between the molds. Light source 4 and reflector 5
The mold roller 3 is also mounted at a fixed position within the rotating mold roller 3. After curing, the substrate is adhered thereto, and is removed from the mold surface while supporting the cured relief structure, and is pressed against the pressing roller 6.
It is transported roughly through the Mold roller 3, pressure roller 2
and 6, a light source 4, a reflector 5, etc. are connected to a support frame 9. In this device, two liquid supply means are used to apply the liquid to the respective surfaces of the substrate and the mold at around 7 and 8, thereby creating a chemical composition in the thick liquid part that is different from the thin composition in the liquid part. , whereby the thickness of each of said liquid layers is greater than the thickness of the relief structure to be transferred. In such a case, two thin liquid layers are sandwiched between the pressure roller 2 and the mold roller 3, and a layer of adhesive adheres to one side of the two, so the composition of one liquid is compared. A relatively large amount of another liquid composition will be deposited on another surface, ie, near the mold surface, in a relatively large amount. Experience has shown that the thick part of the liquid layer in the form of a relief consists relatively largely of the composition supplied to the mold side. If the difference in thickness between the thin liquid portion and the thick liquid portion is relatively large, the difference is significant. It is preferable to use a plurality of liquids having low or almost equal viscosities and to press the pressure roller 2 against the surface 3 of the mold roller with a large force according to the above formula. Examples of suitable liquids include 50% by weight of TPODA, 44% by weight of 0TA480, 5% by weight of DMPA,
And on the mold surface, 50% by weight of TPGDA, 0TA4
80 50% by weight mixed liquid. The viscosity of these mixtures is approximately 75 CP at a shear rate of 105/sec. T
GDDA and OTA 48Q are trade names of Union Shimitsuku Perche Co., Ltd., and their chemical composition is tripropylene glycol diacrylate (tripropylene glycol diacrylate).
glycoldiacrylate) and oligotriacrylate (oligotriacrylate) with a molecular weight of approximately 480.
acrylate). The chemical composition of DMPA is l
, 1-dimethoxy-1-vinyl-acetophenone (1
,j-dimethoxyl --vinyl-ac
etophenone). Another common mixture of acrylic monomers and oligomers that can be used is N-vinyl-2-pyrrolide 7 (
N-vinyl-2-pyrolidone)
, benzyl acrylate
ate), tetrahydrofurfuryl acrylate (
tetrahydrofu-rfirylacryl
ate), or Laronam AR-8496, a product of BASF, and Degussa (De
Trimethylpropane triacrylate (trime
thylpropanetriacrylate). Epoxy resin except for acrylate. Other curable polymers such as polyacrylate silicone may also be used. The type of device according to FIG. 1 is transparent to allow the passage of ultraviolet radiation from the light source 4. The protruding parts of the relief structure that stand out from the actual mold surface are preferably made of an opaque material that does not transmit ultraviolet light. Suitable materials for these raised portions of the mold surface include chromium, titanium, and certain glasses such as chalcogenide glasses. The material of the mold surface itself is quartz 1
It may be quartz glass or thin plexiglass, so that the surface structure is supported inwardly by an auxiliary structure forming part of the rotatable roller body. Such a relief structure is briefly shown in FIG. In this figure, reference number 21 indicates a transparent roller surface, and 22a
, 22b and 22C refer to the ultraviolet opaque portions of the relief structure. 23 is a curable liquid layer, and 24 is a substrate. In this arrangement, the ultraviolet light 25 acts only on the thick part of the liquid film. After first being chemically diffused, portions of the liquid layer that are masked to avoid direct irradiation are also cured. It has been found that for liquid layers that exhibit shrinkage during curing, such as the compositions described above, the thinner parts of the liquid layer are partially channeled into the thicker parts of the liquid layer that harden more quickly. Since this happens again and again, this shrinkage can be taken into account when transferring the relief structure to the mold surface. The apparatus of Figure 1 can also be used with thermoplastic fluids. In fluid form, this liquid adheres to or is present on the substrate surface and/or mold surface, and cools and hardens during the transfer from the first pressure roller 2 to the second pressure roller 6. In this case, the transfer accuracy can be increased, and if the mold surface 21 is relatively cooled and thermally conductive, the wear of the mold can be reduced. 22a and 22b of the relief structure. This is because 22C... is made of a thermally insulating material such as plastic such as Teflon or glass. The apparatus is capable of processing both organic thermoplastics such as polyvinyl chloride and polyamide, and inorganic thermoplastics such as solder types such as tin-lead half-metal or lead-cadmium solders. Inorganic conductive thermoplastics can be advantageously used to fabricate electrical conductors into flexible printed circuit boards used in the microelectronic industry. In the apparatus of FIG. 1, the required relief structures are successively realized on a web of substrate or tape. Rectangular or circular sections can be cut or punched out of these tapes or webs and these sections can be used, for example, as (flexible) printed boards or (flexible) video discs. The method of the invention can also be used in discontinuous processing. In this case, it has been found to be advantageous in the present device to bring the substrate into line contact with the mold surface, followed by surface contact during the curing step. Although high pressure can be applied to the line contact surface,
This has proven advantageous in increasing the difference in thickness between the thin and thick parts of the relief. However, it has proven advantageous not to apply such high pressures during the actual curing process. The overpressure at this time is desirably below ioo or ooopa, and in special cases below 1000 Pa. In the continuous processing process explained in connection with Fig. 1,
During the curing step, the curved tension within the substrate tape is used to press the substrate against the mold surface. This bending tensile force is 1000p
a is generated in normal substrate materials which is smaller than the maximum pressure at the nip between the pressure roller 2 and the mold roller surface 3, which is considerably smaller than the maximum pressure at the nip. Examples of suitable materials include polyethene terephtha L/
-to(polythene terepththal)
ate, DuPont mylar), polyimide (pol
yimide, Kapton manufactured by DuPont), polymethylmethacrylate (polymethylmethacrylate)
late, all of which are in some cases metallized), and also aluminum. There are sheet metals such as titanium or stainless steel. The sheet metal of the substrate consists of several layers, for example divided into a structural carrier and a mechanical support layer. The method of the invention can also be used to create relief structures on strip-shaped molds. The device for carrying out this method is the third
As shown in the figure. Carrier band 3 that supports the relief to be transferred
1 is supplied to a roller field (here, a smooth roller) via a pressure roller 32. The mold band 40 is supplied to the roller 33 via the roller 41, separated from the roller 33, and wound up via the roller 42. Liquid supply means 37
and 38 wet the surfaces of carrier 41 and mold 40 with a liquid. In this embodiment, as in FIG. 1, a liquid that is cured by light may be used, in which case the light source 34 and reflector 35 are mounted below the support frame 39. In this case, both the mold band and the roller 33 must be at least partially transparent for UV transmission as described in FIG. The curing liquid may be applied in the same manner as the temperature curing liquid in FIG. 1, or in a different manner, in which case the mold band and thus the roller 33 may be used in the same manner as described with reference to FIG. The r0 type and the board are t'roller 36.
The substrate is then separated from the mold and removed from the mold. Thereafter, the mold is drawn to a take-up reel (not shown) via rollers 42. [Effect] The method and apparatus according to the present invention provide flexible printed circuit boards 2
Diffraction gratings, grating lenses, Fresnel lenses. LP records, compact discs, video discs,
It is used to implement relief structures in products such as positive and digital optical tapes with so-called zero-order grating diameters. These products differ significantly from similar products made using other methods and equipment in the relief characteristics, which include thinner and thicker areas. These differences include significant differences in thickness, differences in the concentration of catalysts, photoinitiators, internal mold release agents, solvents, filling fluids, etc., differences in degree of polymerization, or differences in polymerization form.
These include differences in the degree of crystallization or differences in crystal form. 4. Brief description of the drawings FIG. 1 is a diagram showing a first embodiment of the apparatus according to the present invention, FIG. FIG. 2 is a diagram showing two embodiments.

Claims (21)

[Claims] (1) Applying a curing liquid between the substrate and the surface of the mold having holes or protrusions corresponding to the negative shape of the relief to be transferred, and then pressing the surface of the mold and the substrate at least locally; Each part of the mold surface and the substrate do not move in any direction other than perpendicular to the contact surface, and the curing liquid then cures, during which there is no mutual movement between the mold surface and the substrate, both of which are initially In a method for transferring a relief structure to a substrate that remains pressed with a pressure lower than the pressure in the pressing step and separates the substrate and the mold surface after the liquid hardens, the liquid portion forms a high relief portion; A method for transferring a relief structure to a substrate, characterized in that the liquid part forming the low relief and the chemical or physical parameters governing the curing process are significantly different from each other. (2) A method for transferring a relief structure to a substrate according to claim 1, wherein the curing speed of the liquid is determined by these widely different chemical or physical parameters. (3) The pressure exerted when the two surfaces press against each other is sufficient such that the thickness of the liquid part forming the high relief area is 50% greater than the thickness of the liquid part forming the low relief area. A method for transferring a relief structure to a substrate according to claim 1 or 2, characterized in that the method uses high pressure. (4) The substrate and the mold surface are pressed against each other along the contact line and are thereafter held in contact, so that the pressure at the line contact is at least 10 times greater than the pressure at the contact state. A method for transferring a relief structure according to any one of claims 1 to 3 to a substrate. (5) The pressure required to press the substrate and mold surface together is 4×10^6×b×h×u×r or more, where b is the width of both sides and h is the hardening liquid. viscosity, u is the speed of the substrate, r is according to the equation 1/r=1/r1+1/r2, which means that r1 and r2 are the respective bending radii of the substrate and mold surface at the contact line on the input side. A method for transferring a relief structure according to claim 4 to a substrate. (6) A method for transferring a relief structure onto a substrate according to any one of claims 1 to 5, wherein the difference in height of the relief structure is less than 100 microns. (7) A method for transferring a relief structure to a substrate according to claim 6, wherein the difference in height is 1 micron or less. (8) The concentration of one of the chemical constituents determining liquid velocity, such as a catalyst or a photoinitiator, is at least 50% or more in one of the liquid parts. A method for transferring the relief structure according to any one of Item 7 to a substrate. (9) The method for transferring a relief structure onto a substrate according to claim 4, wherein the concentration is at least 50% or more in the fluid portion forming the relief portion where the concentration is higher. (10) A layer of the first liquid of the curing liquid between the mold surface and the substrate is deposited on the substrate, and a layer of the second liquid is deposited on the mold surface, thereby changing the chemical or physical parameters of both liquid layers. A method for transferring a relief structure to a substrate according to any one of claims 1 to 9, wherein the relief structures are different from each other. (11) The liquid is cured by the action of electromagnetic light, and the intensity of this light is at least 50% or more in one of the liquid parts. A method for transferring a relief structure described in 1 to a substrate. (12) Transferring the relief structure according to claim 6 to the substrate, characterized in that the light beam intensity is higher in the above method than in those liquid parts forming the higher relief parts. Method. (13) The liquid is a thermosetting liquid, and the temperature of the liquid forming the lower relief portion is higher than the temperature of the liquid forming the higher relief portion. A method for transferring the relief structure according to any one of items 1 to 6 to a substrate. (14) The liquid is a thermoplastic liquid, and the temperature of the liquid forming the lower relief portion is higher than the temperature of the liquid portion forming the higher relief portion. 7. A method for transferring the relief structure according to any one of items 6 to 6 onto a substrate. (15) Claim 1, characterized in that the relief structure has a spatial resolution of less than 100 microns.
A method for transferring the relief structure according to any one of items 1 to 14 to a substrate. (16) A method for transferring a relief structure to a substrate according to claim 14, wherein the spatial resolution is less than 1 micron. (17) A transfer device that presses the substrate and the mold surface against each other with a liquid layer sandwiched between them, a means for supplying the substrate to the transfer device, and a means for applying a curing liquid. An apparatus for transferring a relief structure onto a substrate, comprising a first liquid supply means for applying a thin liquid layer to the substrate, and a second liquid supply means for applying a thin liquid layer to the mold surface. An apparatus for transferring a relief structure onto a substrate, characterized by: (18) At least in the recessed part of the mold relief, the mold substrate is transparent in order to be irradiated with electromagnetic light having a wavelength of 200 nanometers to 2000 nanometers, and the transparency of the extended portion of the relief structure extending to the mold surface is determined by the electromagnetic radiation. 18. A device for transferring a relief structure onto a substrate according to claim 17, characterized in that it is at least 50% or less with respect to the light beam. (19) The mold surface is a good thermal conductor, for example made of a metal such as copper, aluminum, or steel, and the thermal conductivity of the extension of the relief structure extending to the mold surface is less than this. 18. Device for transferring relief structures to a substrate according to claim 17, characterized in that the relief structure is low and made of a non-metal, e.g. plastic, or a non-metallic glass. (20) Claims 1 to 19 characterized in that the physical or chemical parameters and properties of the high relief part are different from those of the low relief part, for example significantly different in thickness. A carrier with a relief structure incorporated into the method or apparatus according to any of the preceding claims. (21) The physical or chemical parameters and properties of the high relief part are significantly different from the parameters and properties of the low relief part, e.g. significantly in the concentration of catalyst or reaction initiator, crystal structure or degree of crystallinity, polymerization structure or degree of polymerization. 21. A carrier with a relief structure incorporated into a method or apparatus according to any one of claims 1 to 20, characterized in that there is a difference.