TWI577524B - Sheet for regenerating mold - Google Patents

Description

Mold recycling sheet

The present invention relates to a sheet for mold reproduction for cleaning a surface of a mold.

In the method of encapsulating a semiconductor device by transfer molding using a resin, resin molding is usually continuously performed using a mold. As the number of repetitions (number of injections) of the resin molding increases, contaminants such as the components, burrs, and dust leaking from the resin accumulate on the surface of the mold, specifically on the surface of the cavity. This contaminant deteriorates the detachability of the molded product from the mold and forms a rough surface on the molded product. Therefore, the mold surface (hole surface) is cleaned at intervals of a predetermined number of repeated moldings (number of injections).

In order to perform cleaning in the above manner, a method of cleaning a material using a mold formed in a sheet is proposed (see, for example, Patent Document 1). The method includes coupling an upper mold and a lower mold and interposing the mold cleaning material therebetween such that the mold cleaning material is filled in the cavity; thermal molding is performed under such conditions to adhere contaminants to the mold cleaning material; and then the mold is peeled off The material is cleaned to remove the contaminant from the surface (hole surface) of the mold along with the mold cleaning material.

Further, the applicant of the present invention has proposed a sheet for regenerating a mold having improved cleaning performance (see, for example, Patent Documents 2 and 3). The sheet for regenerating the mold is formed with a sheet of paper or a sheet of cloth, wherein the mold cleaning material is disposed on at least one surface of the sheet to protrude in a predetermined pattern having an exhaust gap. By using the sheet for regenerating the mold, the void in the cavity Gas can be easily discharged from the exhaust gap. Thus, no air is trapped in the cavity and the mold cleaning material can fill the entire portion of the cavity. Therefore, cleaning can be performed throughout the entire portion of the cavity, thereby improving cleaning performance.

Patent Document 1: JP-A-2004-130819

Patent Document 2: JP-A-2007-196586

Patent Document 3: JP-A-2008-132759

However, even in the case of using a sheet for mold reproduction having improved cleaning characteristics, there are still some examples in which the contaminants cannot be sufficiently removed. Accordingly, the inventors of the present invention have conducted research on the cause of such a problem, and have found that the composition for the mold cleaning material is in a heterogeneous mixed state, resulting in deterioration of the filling of the mold cleaning material in the cavity.

The present invention has been made in view of the above, and an object of the present invention is to provide a sheet for recreating a mold having a high cleaning property and capable of recognizing a mixed state of a composition for a mold cleaning material.

In order to achieve the above object, the present invention relates to the following items (1) to (11).

(1) a sheet for mold reproduction, the sheet comprising: a sheet of paper and a sheet of cloth; and a mold cleaning material comprising a composition mainly composed of an unvulcanized rubber or a composition mainly composed of a thermosetting resin. Forming at least one surface of the paper sheet or the cloth sheet in a predetermined pattern having an exhaust gap, wherein the film containing the composition is formed on the paper sheet disposed at a portion of the exhaust gap or On the surface portion of the sheet of cloth, so by the thin The state of formation of the film identifies the state of mixing of the composition forming the pattern.

(2) The sheet for mold reproduction according to (1), wherein the film has a thickness of 500 μm or less.

(3) The sheet for mold reproduction according to (1) or (2), wherein the pattern has a non-flat top portion.

(4) The sheet for mold reproduction according to (3), wherein the uneven top portion is composed of a convex portion having a radius of curvature in a range of 0.2 to 3.0 mm.

(5) The sheet for mold reproduction according to any one of (1) to (4) wherein the pattern is formed of a plurality of ribbons or a plurality of dots.

(6) The sheet for mold reproduction according to (5), wherein the ribbons or dots have a width and a thickness each ranging from 1 to 5 mm, and the adjacent ribbons or dots The distance between the two is set in the range of 1 to 5 mm.

(7) The sheet for mold reproduction according to (5), wherein a distance between the adjacent strips or dots is set to be 0.5 to 2.0 times the width of the strips or dots.

(8) The sheet for mold reproduction according to (5), wherein the width of the ribbon or the dot is set to be 0.8 to 1.2 times the thickness of the ribbon or the dot.

The sheet for mold reproduction according to any one of (1) to (8), wherein the sheet is a non-woven fabric.

(10) The sheet for mold reproduction according to (9), wherein the non-woven fabric is a spunbonded non-woven fabric.

The sheet for mold reproduction according to any one of (1) to (10), wherein the sheet of the sheet is subjected to a molding treatment.

The inventors of the present invention have made a mixed state of a mold cleaning material, the mixing The state can be identified by using a predetermined pattern in which the exhaust gap has a high cleaning performance of the sheet for mold reproduction as highlighted by the applicant of the present invention, and the studies are repeated. As a result, the inventors have revealed that when a film containing the mold cleaning material is formed on the surface of the paper sheet or a portion of the cloth sheet at the portion of the exhaust gap portion, the film can be identified by the formation state of the film. The mixing state of the mold cleaning material. The present invention is based on this finding.

More specifically, although the mold cleaning material comprises a composition mainly composed of an unvulcanized rubber or a composition mainly composed of a thermosetting resin, the composition also includes an inorganic filler such as cerium oxide powder or titanium oxide, and the filler is not The dissolved state is dispersed therein. As described above, when the inorganic filler is dispersed in a heterogeneous manner, the mold cleaning material cannot be filled in the voids, resulting in deterioration of cleaning performance. The reason why the inorganic filler is dispersed in a heterogeneous manner is that the mold cleaning material is extremely thick in the protruding pattern, so that the inorganic filler cannot be recognized. However, when a film having the composition is formed, the homogeneous dispersion of the inorganic filler gives the film a uniform hue and a smooth surface. When the inorganic filler is not dispersed in a homogeneous manner, the film exhibits a non-uniform color tone. Further, when the inorganic filler is non-dispersed but forms an agglomerate, the agglomerates appear as convex portions on the surface of the film. These different states of film formation can be identified by visual inspection.

In the color tone recognition film according to the above, the inorganic filler may have a more remarkable color than the color of the main component (base material) of the composition of the film (mold cleaning material). For example, when the main component of the composition is colorless and transparent, a colored (e.g., white) inorganic filler can be used. When the main component of the composition is light (for example, white), it can be used Dark (eg, black) inorganic filler. When the main component of the composition is dark (e.g., brown or gray), a light colored (e.g., white) inorganic filler can be used. In other words, the color of the main component of the composition and the color of the inorganic filler may be opposite to each other or in view of easy identification to show a clear contrast between light and dark.

Forming a sheet for mold reproduction according to the present invention from a paper sheet or a sheet material, wherein a mold cleaning material comprising a composition mainly composed of an unvulcanized rubber or a composition mainly composed of a thermosetting resin is formed on the paper sheet or At least one surface of the cloth sheet is projected to have a predetermined pattern having an exhaust gap. Therefore, when the mold for mold regeneration is used to clean the mold according to the present invention, the mold cleaning material can be filled in the cavity while the air stored in the cavity is discharged through the exhaust gap. Therefore, no air is trapped in the hole relay to improve the filling property of the mold cleaning material in the cavity, so that the entire area of the cavity can be cleaned. Further, the sheet for mold reproduction according to the present invention has a film containing the composition on the surface portion of the paper sheet or the sheet of the sheet disposed at the portion of the discharge gap. Since the hue or surface condition of the film represents the mixed state of the composition, the film formation state makes it possible to recognize the mixed state of the composition forming the pattern. Therefore, when the composition is in a heterogeneous mixed state, the composition is considered to be unsuitable for mold cleaning and may not be practically used. In other words, the film can be used for quality control of the sheet for mold reproduction according to the present invention.

Specifically, when the film has a thickness of 500 μm or less, the mixed state of the composition can be easily exhibited on the film. Therefore, the mixed state of the composition can be identified relatively easily.

Further, when the pattern has a top portion which is formed in a non-flat shape, even if the opening of the cavity is extremely small, the air stored in the cavity can be easily discharged. This is because the top portion of the mold cleaning material partially blocks the opening. Therefore, the filling performance of the mold cleaning material is additionally improved along with the improvement of the cleaning performance in the cavity.

In particular, when the uneven top portion of the pattern has a convex portion having a radius of curvature in the range of 0.2 to 3.0 mm, the filling property of the mold cleaning material and the cleaning property in the cavity are further improved.

In addition, when the pattern is formed in the form of a plurality of strips or a plurality of dots, it is easy to set the shape and the shape and size of the exhaust gap. It is also extremely easy to set the mold cleaning material to be in a form suitable for filling the cavity.

In particular, when the ribbons or dots are set to have a width and thickness ranging from 1 to 5 mm, and the distance between the adjacent ribbons or dots is set at 1 to In the range of 5 mm, it is possible to achieve a size suitable for cleaning a mold for transfer molding in a resin-encapsulated semiconductor device. Therefore, the mold for transfer molding can be appropriately cleaned.

Moreover, when the distance between the adjacent strips or dots is set to be 0.5 to 2.0 times the width of the strips or dots, the volume of the exhaust gap is appropriately balanced and The amount of mold cleaning material used. In this way, air can be passed through the cavity and the mold cleaning material can be filled more reasonably.

At the same time, the pattern has a ribbon or dot width set to be 0.8 to 1.2 times the thickness of the ribbon or the dot and has excellent shape stability, so that the filling property of the mold cleaning material is remarkably improved.

When the cloth sheet is formed of a non-woven fabric, the cloth sheet has a rough table The surface thus improves the registration effect of the mold cleaning material, thereby increasing the adhesion between the cloth sheet and the mold cleaning material.

More specifically, when the non-woven fabric is a spunbonded non-woven fabric, the relative tensile strength is not oriented, and the stress applied during hot molding is absorbed and easily relaxed. Therefore, the sheet hardly tears during hot molding. Further, since the sheet does not tear even during peeling (release) from the mold, the peeling (release) operation is extremely easy.

Further, when the cloth sheet is subjected to the molding treatment, since the sheet has a rough surface, the registration effect of the mold cleaning material can be improved and the adhesion between the cloth sheet and the mold cleaning material is increased.

Next, embodiments of the present invention will be more specifically discussed based on the drawings.

Fig. 1 shows a first embodiment of a sheet for mold reproduction of the present invention. The sheet for mold reproduction according to this embodiment includes a substrate sheet 1 composed of a paper sheet or a sheet material, and a mold cleaning comprising a composition mainly composed of an unvulcanized rubber or a composition mainly composed of a thermosetting resin. The material is formed in a strip shape on both sides of the substrate sheet 1. That is, the protruding lines (ribbons) 2A which are the constituent members of the strip-shaped pattern are disposed so as to have a gap therebetween in parallel with each other, and each of the gaps serves as an exhaust gap while the mold is subjected to a cleaning process. Further, the film 3 containing the composition is integrally formed with the protruding lines 2A on the surface portion of the substrate sheet 1 provided at the portion of the exhaust gap portion. The state of mixing of the composition can be identified via the hue or surface condition of the film 3. As described above, one of the main aspects of the present invention relates to the shape of the film 3 in relation to the state in which the composition of the mold cleaning material can be identified. to make.

Specifically, the mold cleaning material and the composition of the film 3 (an unvulcanized rubber-based composition or a thermosetting resin-based composition) include a mixture with an inorganic filler such as cerium oxide powder or titanium dioxide. Vulcanized rubber or thermosetting resin (main component). Although the inorganic filler was dispersed in an insoluble state, when the inorganic filler was dispersed in a homogeneous manner, the film 3 showed uniform color tone and a smooth surface. However, when the inorganic filler is dispersed in a heterogeneous manner, the film 3 exhibits uneven color tone. Further, when the inorganic filler is not dispersed but forms agglomerates, the agglomerates partially appear as convex portions on the surface of the film 3. For example, in the case of a composition mainly composed of a thermosetting resin, the thermosetting resin (main component) is usually colorless and transparent or translucent. When the thermosetting resin is mixed with an inorganic filler, the resulting mixture becomes white or opaque. However, when the inorganic filler is in a non-uniformly dispersed (mixed) state, a transparent or translucent portion of the main component can be seen on the film 3. This state of formation of the film 3 can be recognized by the naked eye.

Next, when the composition is mixed in a homogeneous manner by the formation state of the film 3, the mold cleaning material of the protruded lines 2A can fill the entire cavity. Therefore, the entire area of the cavity can be cleaned. On the other hand, when it is recognized that the composition is mixed in a heterogeneous manner, it is not suitable for mold cleaning and thus cannot be used for mold cleaning.

More specifically, in view of the ease of recognizing the mixed state of the composition appearing on the film 3, the film 3 may have a thickness of 500 μm or less, and particularly a thickness in the range of 20 to 150 μm. If the film thickness is small At 20 μm, the film was too thin to recognize the mixed state of the composition.

As described above, the composition includes an unvulcanized rubber or a thermosetting resin mixed with an inorganic filler such as cerium oxide powder or titanium oxide. Specifically, 100 parts by weight of the unvulcanized rubber or thermosetting resin is preferably combined with about 40 to 50 parts by weight of cerium oxide powder or about 5 parts by weight of titanium dioxide. Additional ingredients may be added if needed.

Specific examples of the unvulcanized rubber include natural rubber (NR), chloroprene rubber (CR), butadiene rubber (BR), nitrile rubber (NBR), ethylene propylene diene rubber (EPDM), and ethylene propylene rubber (EPM). ), styrene butadiene rubber (SBR), polyisoprene rubber (IR), isobutylene isoprene rubber (IIR), polyoxymethylene rubber (Q) and fluororubber (FKM).

Specific examples of the thermosetting resin include melamine resin.

A method of manufacturing a sheet for mold reproduction includes, for example, kneading a composition by a continuous kneader or a batch kneader, and then arranging the composition on both sides of the substrate sheet 1. Then, the resultant structure is sandwiched and pressed between two dies each having a strip-shaped pattern of the mold cleaning material and a convex portion corresponding to the film 3. Therefore, the strip pattern and the film 3 are integrally formed on both surfaces of the substrate sheet 1. The resulting structure is then rolled or cut to any size. In this way, a sheet for mold reproduction can be obtained.

In the above embodiment, the film 3 is formed on the entire surface portion of the substrate sheet 1 where the protruding lines 2A of the strip-shaped pattern are provided. However, since the film 3 is used to identify the above-mentioned mold cleaning materials The mixed state of the composition may be formed only on a portion of the surface of the substrate sheet 1 between the protruded lines 2A.

Further, although the above embodiment includes simultaneous formation of the strip-shaped pattern and the film 3 by the molding, the strip-shaped molding can be performed and then the film 3 can be formed by coating.

In the above embodiment, the longitudinal directions of the protruding lines 2A of the strip-shaped pattern on the surface of the substrate sheet 1 and its back surface are identical to each other. However, as shown in FIG. 2, the two longitudinal directions may be different from each other (for example, 90 degrees out of FIG. 2). As illustrated in FIG. 3, the strip pattern and the film 3 may be formed only on one surface of the substrate sheet 1.

Further, in the above embodiment, the protruding lines 2A of the strip-like pattern have a rectangular shape at a cross section perpendicular to the longitudinal direction of the pattern. However, any other cross-sectional shape can be employed. For example, a trapezoidal shape (see, for example, FIG. 4(a)), a triangular shape (see, for example, FIG. 4(b)), or a semicircular shape (see, for example, FIG. 4(c)) may be employed. Further, the cross-sectional shape may have a hemispherical shape at a top portion thereof and a rectangular shape at a lower portion thereof (see, for example, Fig. 4(d)). In a variation, the cross-sectional shape may be a hemispherical shape at a top portion thereof and a trapezoidal shape at a lower portion thereof (see, for example, Fig. 4(e)). In another variation, the cross-sectional shape may be a pentagonal shape having a curved top portion (see, for example, Figure 4(f)). In still another variation, as illustrated in Figure 4(g), the top portion of the cross-sectional shape can be formed into a hemisphere having a smaller width than the embodiment of Figure 4(d).

In particular, such implementations as illustrated in Figures 4(b) through 4(g) For example, the top portions of the protruding lines 2A of the strip-like pattern are formed to be non-flat. Therefore, even if the opening of the cavity is extremely small, the air stored in the cavity can be easily discharged because the top portion of the mold cleaning material partially blocks the opening. Therefore, the filling performance of the mold cleaning material is improved and the cleaning performance in the cavity is also improved. More specifically, in the embodiments illustrated in FIGS. 4(d) to 4(g), according to the viewpoint of further improving the filling property of the mold cleaning material 2 and the cleaning performance in the cavity, The radius of curvature of the top portion can range from 0.2 mm to 3.0 mm.

According to the above embodiments, the mold cleaning material is formed into a strip pattern and a film 3. However, as exemplified in FIG. 5, the mold cleaning material may be formed into a dot pattern and a film 3. Specific examples of the shape of each of the dots 2B of the dot pattern include a cone, a truncated cone, a cylinder, a cylinder, a pyramid, a truncated pyramid other than the cylindrical shape as illustrated in FIG. And a rectangular cylinder. Although the embodiment of FIG. 5 has a dot pattern and a film 3 which are located only on one surface of the substrate sheet 1, the dot pattern and the film 3 may be formed on both surfaces of the substrate sheet 1.

According to the embodiments of Figures 1 and 2, the cleaning material is formed on both surfaces of the substrate sheet 1 and has the same pattern. However, the patterns on both surfaces of the substrate sheet 1 may be different from each other. For example, the surface of the substrate sheet 1 may have a strip shape and the other surface may have a dot pattern.

The size of the protruding lines 2A of the strip-shaped pattern and the size of the dots 2B of the dot-like pattern are suitably set according to the size, arrangement or the like of the cavity of the mold. Specifically, in the case of cleaning a mold for transfer molding by encapsulating a semiconductor device with a resin, the protruding lines 2A and the dots 2B are each The width and thickness of the person may be set in the range of 1 to 5 mm, and the distance between the adjacent (relative) protruding lines 2A and the dots 2B may be set in the range of 1 to 5 mm.

The adjacent (relative) protruding line 2A and the dot 2B are filled in order to optimize the ventilation in the cavity and to optimize the balance of the volume of the exhaust gap and the amount of the mold cleaning material. The distance between them can be set to be 0.5 to 2.0 times the width of each of the protruding lines 2A and 2B. When the distance between the adjacent protruding lines 2A and the dots 2B is less than 0.5 times the width of the protruding lines 2A, the opening of the holes may be by the protruding lines 2A or 2B The clogging while the mold is being cleaned causes the venting in the cavity to deteriorate and the mold cleaning material to be insufficiently filled. In contrast, when the distance between the adjacent protruding lines 2A is increased by more than 2.0 times the width of the protruding lines 2A, the mold cleaning material can be distributed at a low density in the sheet for mold reproduction, resulting in The mold cleaning material is not sufficiently filled. Specifically, the gap between the adjacent (relative) protruding lines 2A and the dots 2B can be set to be 0.5 to 5 times the cross-sectional area corresponding to each of the protruding lines 2A and 2B. Sectional area.

According to the viewpoint of improving the filling performance of the mold cleaning material by stabilizing the shape of the protruding line 2A and the dot 2B, the width of each of the protruding lines 2A and 2B can be set at a thickness of 0.8 to 1.2. Within the range. When the width of each of the protruding lines 2A and the dots 2B is less than 0.8 times the thickness thereof, the protruding lines 2A and the dots 2B tend to be more easily deformed. Therefore, it is difficult to maintain the exhaust gap while the mold is cleaned, resulting in deterioration of ventilation in the cavity and insufficient filling of the mold cleaning material. In contrast, when When the width of each of the protruding line 2A and the dot 2B is increased by more than 1.2 times the thickness thereof, the opening of the cavity can be cleaned by the mold before the mold cleaning material is completely filled in the cavity. The clogging causes deterioration of the venting in the cavity and insufficient filling of the mold cleaning material.

Examples of the cloth sheet of the substrate sheet 1 include woven fabrics, non-woven fabrics, and knitted fabrics. Wherein the woven fabric and the non-woven fabric containing long fibers have suitable rough surfaces, thereby improving the quasi-effect of the protruding lines 2A, the dots 2B and the film 3, and reinforcing the protruding lines 2A (with grasping) Grip) adhesion. From this point of view, it is known that such a woven fabric and a non-woven fabric containing long fibers can be used, and the non-woven fabric can be used from the viewpoint of uniform grip. Further, for the non-woven fabric, a spunbonded non-woven fabric can be used from the viewpoint of mechanical strength, uniformity, and workability. Further, a die-treated cloth sheet may be used, and thus the sheet has a rough surface to improve the registration effect of the protruded lines 2A. The substrate sheet 1 usually has a thickness ranging from 0.1 to 0.8 mm.

Instance

Examples and comparative examples will be discussed below. However, the invention is not limited to the examples.

(cloth sheet)

A spunbonded non-woven fabric composed of polyester long fibers (E01070, available from Asahi Kasei Co., Ltd.) was produced as a substrate sheet. The nonwoven fabric had a tear strength of 8.5 N, a thickness of 0.35 mm, and a basis weight of 70 g/m ² .

(mold cleaning material)

First, 100 parts by weight of ethylene propylene rubber and 50 parts by weight of dioxide are provided. 矽 powder, 5 parts by weight of titanium dioxide, 2 parts by weight of organic peroxide [n-butyl (4,4-bis(tert-butylperoxy)pentanoate], 10 parts by weight of imidazole {(2,4-diamino-) 6-[2'-Methylimidazolyl-(1')]ethyl-s-triazine} and 5 parts by weight of montan wax.

Then, the above components were mixed and kneaded by a kneader. In other words, the mold cleaning material obtained by sufficiently kneading and the mold cleaning material obtained by insufficient kneading are separately provided.

(Manufacturing method of sheet for mold reproduction)

Two substrate sheets are provided, and the mold cleaning material prepared by sufficiently kneading is applied to both surfaces of a substrate. Further, the mold cleaning material prepared by insufficient kneading is applied to both sides of the other substrate. Each of the mold cleaning materials was formed into a strip-shaped pattern having a rectangular cross section (width: 5 mm × height: 3 mm) (the distance between the protruded lines was 5 mm), followed by formation of a film (thickness: 100 μm). Two types of sheets for mold reproduction are thus obtained.

(Identification of sheet for mold reproduction)

The film formation state of the two types of mold-recovering sheets was visually checked. The film exhibiting a uniform color tone by using a sheet obtained by sufficiently kneading the obtained mold cleaning material. In contrast, the film using the sheet of the mold cleaning material prepared by insufficient kneading exhibits uneven color tone.

As apparent from the foregoing, the mold cleaning material obtained by sufficiently kneading showed a homogeneous mixed state of the composition, whereas the mold cleaning material obtained by insufficient kneading showed a heterogeneous mixed state of the composition.

(cleaning performance)

These two types of sheets for mold reproduction are used to achieve cleaning of a mold for transfer molding by encapsulating a semiconductor device with a resin. Therefore, borrowing The sheet obtained by sufficiently kneading the film-forming cleaning material cleans the mold throughout the cavity. In contrast, the use of a sheet of the mold cleaning material obtained by insufficient kneading cannot clean the mold throughout the cavity.

It can be seen from the foregoing that the mold cleaning material obtained by sufficiently kneading exhibits excellent filling properties (cleaning performance) in the cavities, whereas the mold cleaning material obtained by insufficient kneading exhibits filling properties (cleaning performance) )bad.

(Comparative example)

In the same method as the above example, the two types of sheets for mold reproduction are obtained by using the mold cleaning materials having different kneading states. Here, however, only the strip shape is formed without forming a film. Thus, the substrate sheet is exposed between the adjacent protruding lines of the strip pattern.

After the projection lines of the comparative strip shape were visually verified, the kneading state of the mold cleaning materials could not be identified.

Therefore, from the above results, it can be seen that the film of this example can effectively recognize the mixed state of the composition of the mold cleaning material.

Further, in the above examples, the film has a thickness of 100 μm, and the same tendency can be obtained only when the film has a thickness of 20 μm, 150 μm, and 500 μm.

The above examples use a composition mainly composed of an unvulcanized rubber as a mold cleaning material, and the same tendency can be obtained only when a composition mainly composed of a melamine resin as a main component and a thermosetting resin is used.

Although the present invention has been described in detail with reference to the specific embodiments of the present invention, it will be understood by those skilled in the art From its spirit and scope.

Incidentally, the present application is based on Japanese Patent Application No. 2011-178946, filed on Jan. 18, 2011, which is hereby incorporated by reference.

All references cited herein are hereby incorporated by reference in their entirety.

The sheet for mold regeneration according to the present invention can visually recognize the mixed state of the composition of the mold cleaning material, and therefore only such high quality products can be used for cleaning the cavity surface of the mold.

1‧‧‧Substrate sheet

2A‧‧‧Jumping line/belt

2B‧‧‧ points

3‧‧‧film

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a perspective view illustrating a first embodiment of a sheet for mold reproduction of the present invention.

Figure 2 is a perspective view illustrating a second embodiment of the sheet for mold reproduction of the present invention.

Figure 3 is a perspective view illustrating a third embodiment of the sheet for mold reproduction of the present invention.

4(a) to 4(g) are cross-sectional views respectively illustrating modified examples of the protruding lines of the sheet for mold reproduction of the present invention.

Figure 5 is a perspective view illustrating a fourth embodiment of the sheet for mold reproduction of the present invention.

1‧‧‧Substrate sheet

2A‧‧‧Jumping line/belt

3‧‧‧film

Claims (11)

A sheet for mold reproduction, the sheet comprising: a sheet of paper or a sheet of cloth; and a mold cleaning material comprising a composition mainly composed of an unvulcanized rubber or a composition mainly composed of a thermosetting resin, and formed on the sheet a predetermined pattern having an exhaust gap formed on at least one surface of the material or the cloth sheet, wherein the film containing the composition is formed on the paper sheet or the cloth sheet at a portion of the exhaust gap The surface portion is such that the mixed state of the composition forming the pattern can be recognized by the state of formation of the film. The sheet for mold reproduction according to claim 1, wherein the film has a thickness of 500 μm or less. A sheet for mold reproduction according to claim 1 or 2, wherein the pattern has a non-flat top portion. The sheet for mold reproduction according to claim 3, wherein the uneven top portion is formed by a convex portion having a radius of curvature in a range of 0.2 to 3.0 mm. A sheet for mold reproduction according to claim 1 or 2, wherein the pattern is formed of a plurality of ribbons or a plurality of dots. The sheet for mold reproduction according to claim 5, wherein the strips or dots have a width and a thickness in a range of 1 to 5 mm, and a distance between adjacent strips or dots is set at 1 Up to 5mm. The sheet for mold reproduction according to claim 5, wherein a distance between the adjacent strips or dots is set to a width of the strips or dots 0.5 to 2.0 times. The sheet for mold reproduction according to claim 5, wherein the width of the ribbons or dots is set to be 0.8 to 1.2 times the thickness of the ribbons or dots. A sheet for mold reproduction according to claim 1 or 2, wherein the sheet is a non-woven fabric. The sheet for mold reproduction according to claim 9, wherein the non-woven fabric is a spunbonded non-woven fabric. A sheet for mold reproduction according to claim 1 or 2, wherein the sheet of the sheet is subjected to a molding treatment.