JP5731893B2 - Imprint mold - Google Patents

Description

  The present invention relates to an imprint mold for transferring a predetermined pattern to a resin in the production of a wiring board.

  In nanoimprint technology, a resin placed on the base of a manufacturing apparatus is pressed against a resin surface by pressing an imprint mold in which a convex portion capable of transferring a predetermined pattern is formed on the main surface of the substrate. The pattern is transferred. Thereafter, the resin is cured to form a resin layer, and a metal is deposited in the concave portion of the resin layer, whereby a wiring board provided with metal wiring on the main surface is manufactured.

JP 2008-287805 A

With the recent miniaturization of electronic equipment, multilayer printed wiring boards are used as an alternative to rigid boards, and the adhesion of metal wiring formed on the main surface of the wiring board and the wiring board is further improved. It has been demanded.
In addition, when forming a via recess by penetrating the convex portion of the imprint mold through the resin disposed on the base of the manufacturing apparatus, a resin residue may be generated at the bottom of the via recess. When a resin layer is formed by curing the resin while the resin residue is generated and a metal is deposited in the via recess, a thin resin layer exists at the end of the via layer. After that, when the metal layer and the via layer of the external substrate are connected, the thin resin layer is interposed between the metal layer and the via layer, so that the conduction between the metal layer and the via layer may be deteriorated. Therefore, it is necessary to remove the resin residue at the bottom of the recess for via by ashing or the like.

As a method for reducing the resin residue or simplifying the ashing process, a technique has been proposed in which a fine protrusion is provided on the top surface of the convex portion of the imprint mold to roughen the top surface (see, for example, Patent Document 1). .) According to the technique disclosed in Patent Document 1, the shape of the minute protrusions propagates to the surface of the resin, and the surface of the resin becomes rough. As a result, since the surface area where the resin is exposed to the plasma in the ashing process is increased, an effect of facilitating removal of the resin residue can be obtained.
However, since the fine protrusions and the resin or the external substrate come into contact with each other at the time of imprinting, there is a problem that the pressure is concentrated on the fine protrusions and the imprint mold is easily broken.
As described above, a first object of the present invention is to provide an imprint mold capable of improving the adhesion between a wiring board and a metal wiring formed on the wiring board. A second object of the present invention is to provide a durable imprint mold that can reduce the resin residue of the transfer pattern when forming vias by imprinting.

A first aspect of the present invention comprises a substrate, and a pattern projection formed on the main surface a surface of the substrate to allow transferring a predetermined pattern, on top of the pattern projection unit A protrusion is provided, and the protrusion is an imprint mold formed so as to go around the peripheral edge of the top.
A second aspect of the present invention includes a base material, and a pattern convex portion formed on the main surface of the base material capable of transferring a predetermined pattern, and a peripheral edge of a top portion of the pattern convex portion Protrusions are provided on at least a part of the part, and the protrusions are summarized as an imprint mold in which a plurality of protrusions are formed in parallel to each other.
A third aspect of the present invention includes a base material, a pattern convex portion formed on the base material, and a via convex portion formed on the pattern convex portion. The area of the top of the part is smaller than the top of the pattern convex part, and a protrusion is formed on the top part of the pattern convex part and the top part of the via convex part, and the protrusion makes a round around the peripheral part of the top part. The gist of the imprint mold is as follows.
A fourth aspect of the present invention includes a base material, a pattern convex portion formed on the base material, and a via convex portion formed on the pattern convex portion. The area of the top of the part is narrower than the top of the pattern convex part, and a protrusion is formed on at least a part of the peripheral part of each of the top part of the pattern convex part and the top part of the via convex part. The gist is an imprint mold in which a plurality of parallel prints are formed.
The fifth aspect of the present invention is summarized as an imprint mold in which the height / width of the protrusion in the cross section perpendicular to the longitudinal direction of the protrusion is 0.1 or more and 5 or less.

According to the present invention, by providing a protrusion on the top peripheral edge of the convex portion of the imprint mold, the shape of the protrusion is propagated to the surface of the resin during imprinting, and the surface area of the resin is widened. This improves the adhesion between the wiring board and the metal wiring formed on the wiring board.
According to the present invention, by providing a protrusion on the top peripheral edge of the convex portion of the imprint mold, the thickness of the resin pressed by the protrusion is reduced, and the resin residue can be easily removed in the subsequent process. Conductivity with the metal layer of the external substrate can be ensured.
According to the present invention, when the imprint is performed, the top portion of the convex portion is flattened by providing the protrusion only on the peripheral portion of the top portion without providing the micro projections over the entire surface of the top portion of the convex portion. Is uniformly distributed throughout the top. As a result, the effect that the imprint mold is hardly broken can be obtained.

(A) is a perspective view of the imprint mold concerning 1st Embodiment, (b) is sectional drawing. It is a top view of the imprint mold concerning a 1st embodiment. It is sectional drawing of the imprint mold concerning 1st Embodiment. It is process drawing which apply | coats the photosensitive resin on a board | substrate in the manufacturing method of the imprint mold concerning 1st Embodiment. It is process drawing which forms the resin layer in the manufacturing method of the imprint mold concerning 1st Embodiment. It is process drawing which forms a hole in a board | substrate in the manufacturing method of the imprint mold concerning 1st Embodiment. It is process drawing which obtains the board | substrate provided with the hole in the manufacturing method of the imprint mold concerning 1st Embodiment. It is process drawing which apply | coats a resist on a board | substrate in the manufacturing method of the imprint mold concerning 1st Embodiment. It is process drawing which provides an electron beam resist layer on a board | substrate in the manufacturing method of the imprint mold concerning 1st Embodiment. It is process drawing which forms protrusion in a part of convex part in the manufacturing method of the imprint mold concerning 1st Embodiment. It is process drawing which presses an imprint mold on resin in the manufacturing method of the wiring board using the imprint mold concerning 1st Embodiment. It is process drawing in which resin is hardened in the manufacturing method of the wiring board using the imprint mold concerning a 1st embodiment. It is process drawing which obtains the wiring board by which the recessed part was formed in the base-material surface in the manufacturing method of the wiring board using the imprint mold concerning 1st Embodiment. It is process drawing which deposits a metal on a wiring board in the manufacturing method of the wiring board using the imprint mold concerning 1st Embodiment. It is process drawing which removes the excess metal by the roll grinding | polishing in the manufacturing method of the wiring board using the imprint mold concerning 1st Embodiment. In the manufacturing method of the wiring board using the imprint mold concerning 1st Embodiment, it is a completion figure of the wiring board by which wiring was provided in the main surface surface. (A) is a top view of the imprint mold concerning 2nd Embodiment, (b) is sectional drawing. It is process drawing which presses an imprint mold to resin apply | coated on the board | substrate in the manufacturing method of the wiring board using the imprint mold concerning 2nd Embodiment. It is process drawing which hardens resin by heating in the manufacturing method of the wiring board using the imprint mold concerning a 2nd embodiment. It is process drawing which obtains the wiring board by which the recessed part was formed on the base material in the manufacturing method of the wiring board using the imprint mold concerning 2nd Embodiment. In the manufacturing method of the wiring board using the imprint mold concerning 2nd Embodiment, it is process drawing which obtains the wiring board by which the metal wiring was provided in the main surface surface. It is a process figure which laminates a plurality of wiring boards in a manufacturing method of a wiring board using an imprint mold concerning a 2nd embodiment. It is sectional drawing of the imprint mold concerning the modification of embodiment. It is sectional drawing of the imprint mold concerning the modification of embodiment. It is sectional drawing of the imprint mold concerning the modification of embodiment. It is a top view of the imprint mold which shows the arrangement pattern (double) of the protrusion concerning the modification of embodiment. It is a top view of the imprint mold which shows the pattern shape (the some protrusion arrange | positioned at substantially equal intervals) of the protrusion concerning the modification of embodiment. It is a top view of the imprint mold which shows the pattern shape (plurality of protrusions formed in a staggered manner) according to the modification of the embodiment. It is a top view of the imprint mold which shows the pattern shape (the some protrusion provided in the C shape) of the protrusion concerning the modification of embodiment. It is a top view of the imprint mold which shows the pattern shape (waveform) of the protrusion concerning the modification of embodiment. It is a top view of the imprint mold which shows arrangement | positioning of the processus | protrusion (protrusion elongate only to the longitudinal direction of one side edge part) concerning the modification of embodiment. It is a top view of the imprint mold which shows arrangement | positioning of the processus | protrusion (protrusion elongate only to a transversal direction) concerning the modification of embodiment.

  Hereinafter, the present invention will be described with reference to embodiments, but the present invention is not limited to the following embodiments. In addition, about the thing which has the same function or a similar function in a figure, the same or similar code | symbol is attached | subjected and description is abbreviate | omitted.

[First Embodiment]
[Imprint mold]
As shown to Fig.1 (a), the imprint mold 1 concerning 1st Embodiment is the base material 2 and the convex part 4 formed in the main surface surface of the base material 2 which can transfer a predetermined pattern. With. As shown in FIG. 1B, the imprint mold 1 is provided with a protrusion 45 on at least a part of the peripheral edge 42 of the top 41 of the protrusion 4. In the present embodiment, protrusions 45 are formed in the vicinity of both side edges of the top portion 41 in the longitudinal direction. The cross-sectional shape orthogonal to the longitudinal direction of the protrusion 45 has a convex shape from the viewpoint of easy manufacture of the imprint mold 1.

  By providing the protrusion 45 on the peripheral edge 42 of the top 41 of the imprint mold 1, the shape of the protrusion 45 propagates to the surface of the resin during imprinting, and the surface area of the resin increases. As a result, the adhesion of the metal wiring formed on the main surface of the resin layer and the resin layer is improved by the anchor effect.

  Specifically, as shown in FIG. 1A, it is preferable to include a pair of protrusions 45 parallel to the peripheral edge portion 42 in the longitudinal direction of the top portion 41. Further, as shown in FIG. 2, it is more preferable that the protrusion 45 is formed along the end portion 43 of the top portion 41 so as to go around the peripheral portion 42 of the top portion 41.

  The height (h) / width (w) of the protrusion 45 in the cross section orthogonal to the longitudinal direction of the protrusion 45 shown in FIG. 1B is preferably 0.1 or more and 5 or less, and is 0.3 or more and 1 or less. More preferably. This is because releasability between the imprint mold 1 and the resin layer is improved during imprinting. Moreover, it is because the adhesiveness of the metal wiring formed in the main surface surface of the resin layer and resin layer by an anchor effect improves.

  The material of the imprint mold 1 is not particularly limited as long as the etching ratio with the mask material is maintained in the manufacturing process described later. As a material of the imprint mold 1, for example, quartz or silicon can be used.

[Imprint Mold Manufacturing Method]
A method for manufacturing the imprint mold 1 including a plurality of convex portions 4 on the substrate 2 as shown in FIG. 3 will be described with reference to FIGS.

(A) A base material 2 made of, for example, quartz or silicon is prepared. Then, as shown in FIG. 4, a mask material capable of ensuring a selection ratio with the base material 2, for example, a photosensitive resin 103, is applied on the base material 2. Thereafter, as shown in FIG. 5, the photosensitive resin 103 is cured using a photolithography method, and the resin layer 3 having predetermined openings 3 a, 3 b, and 3 c is formed on the substrate 2. As the mask material, in addition to the photosensitive resin 103, a silicon oxide film, a silicon nitride film, a metal, or the like can be used.

(B) As shown in FIG. 6, the substrate 2 is dry-etched by supplying a fluorine-containing gas through the openings 3 a, 3 b, 3 c of the resin layer 3 provided on the substrate 2. And the convex part 4 is formed in the both sides by forming hole 49a, 49b, 49c. Thereafter, the resin layer 3 is removed to obtain a base material 2 having holes 49a... 49c as shown in FIG. When silicon is used for the base material, the etching of the holes 49a... 49c is performed using a crystal anisotropic etching solution such as potassium hydroxide (KOH), tetramethylammonium hydroxide (TMAH), ethylenediamine / pyrocatechol solution ( EDP), hydrazine (N ₂ H ₄ .H ₂ O), or the like may be used.

(C) As shown in FIG. 8, a resist is applied so as to cover the surface of the substrate 2 and the convex portion 4 to form a resist layer 5. As the resist, for example, a positive resist (manufactured by Zeon Corporation, product name “ZEP520-22”) can be used. Thereafter, as shown in FIG. 9, openings 5a... 5d are formed in the resist layer 5 other than the portions where the protrusions 45 of the protrusions 4 are formed using an electron beam lithography method.

(D) As shown in FIG. 10, a fluorine-containing gas is supplied through the openings 5a... 5d of the resist layer 5 to dry-etch a part of the protrusions 4 to form protrusions 45. Thereafter, the resist layer 5 is removed. Thus, the imprint mold 1 shown in FIG. 3 is manufactured.

[Method of manufacturing a wiring board]
A method for manufacturing a wiring board using the imprint mold 1 of FIG. 3 will be described with reference to FIGS.

(A) As shown in FIG. 11, the resin 108 applied on the base 10 is heated to press the imprint mold 1. As the resin 108, thermoplastic polyimide can be used. Thereafter, the resin 108 is cooled and cured as shown in FIG. Then, by removing the imprint mold 1, a wiring board 8 having a recess 83 formed on the surface of the base material 82 on which the resin 108 is cured as shown in FIG. 13 is obtained. Convex portions 84 are formed on both sides of the concave portion 83, and protrusions 85 having a convex cross section are formed on part of the bottom portion 81 of the concave portion 83.

(B) As shown in FIG. 14, a metal 109 is deposited on the wiring board 8 so that the recess 83 is buried. For example, after forming a copper (Cu) seed layer by electroless plating, copper (Cu) is deposited by electrolytic plating. After that, as shown in FIG. 15, the excess metal 109 is removed by roll polishing so that the surface of the convex portion 84 and the surface of the metal 109 are flush with each other, thereby forming the wiring 9. In addition to roll polishing, excess metal 109 may be removed by etching using, for example, sulfuric acid or hydrogen peroxide. By removing the base 10, a wiring board 8 having a wiring 9 provided on the surface of the main surface as shown in FIG. 16 is obtained.

  According to the method of manufacturing a wiring board, by providing the protrusion 45 on the top of the convex portion 4 of the imprint mold, the shape of the protrusion 45 propagates to the surface of the resin 108 during imprinting, and the surface area of the resin 108 is reduced. By spreading, the contact area between the wiring board 8 and the wiring 9 increases due to the anchor effect. Therefore, the effect that the wiring 9 (metal) becomes difficult to peel from the wiring board 8 is obtained.

  There is no particular limitation on the use for which it is required to increase the contact area between the bottom surfaces of the wiring board 8 and the wiring 9 and to improve the adhesive strength between the wiring board 8 and the wiring 9, but for example, flexible using polyimide or the like as a base material A wiring board is mentioned.

[Second Embodiment]
[Imprint mold]
In the imprint mold 1 according to the first embodiment, the convex portion 4 has one stage, but the number of stages is not limited, and the above-described imprint mold 1 manufacturing process may be repeated to be a multistage type. The description will focus on the differences from the first embodiment. As a second embodiment, for example, as shown in FIG. 17B, the base 2A, the pattern convex 4A formed on the base 2A, and the via formed on the pattern convex 4A It is good also as the imprint mold 1A provided with the convex part 6, and the area of the top part 61 of the convex part 6 for vias being narrower than the top part 41A of the convex part 4A for patterns. A protrusion 45A having a V-shaped cross section is formed on the peripheral portion of the top 41A of the pattern convex portion, and a protrusion 65 having a V-shaped cross section is formed on the peripheral portion of the via top 61.
Since the shape of the top portion 61 of the via convex portion 6 is not limited to a polygon, the top portion 61 of the via convex portion is circular as shown in FIG. A circular protrusion 65 may be formed on the peripheral edge of 61.

[Manufacturing method of multilayer wiring board]
According to the imprint mold 1A, the multilayer wiring board 38 is manufactured through the following steps. First, (a) as shown in FIG. 18, the resin 108 applied on the base 10 is heated to press the imprint mold 1A. Thereafter, as shown in FIG. 19, the resin 108 is cooled and cured. Then, the imprint mold 1A is removed. Then, as shown in FIG. 20, the wiring board 8A ₁ to the via recess 86A and the wiring recess 83A is formed on the surface of the substrate 82A in which the resin 108 is cured can be obtained. A recess 85A is formed in a part of the bottom 81A of the recess 83A so that the shape of the protrusion 45A of the imprint mold 1A is propagated. The trapezoidal resin residue 88A formed on the bottom of the via recess 86A or a part thereof is appropriately removed by ashing or the like. By disposing the protrusion 65 so as to surround the peripheral portion of the via top 61, a portion where the resin residue becomes thin can be formed on the bottom of the via recess 86A. Thereafter, the resin residue 88A or part of the by ashing or the like trapezoidal by removing from the substrate 82A, it is possible to secure conduction between the metal layer of the wiring board 8A ₂ which will be described later.
(B) Thereafter, the same steps as in FIGS. 14 and 15 are performed. Then, by removing the base 10, as shown in FIG 21, the wiring 9A vias recess 86A and the wiring recess 83A wiring board 8A ₁ formed is obtained.
(C) A multilayer wiring board 38 as shown in FIG. 22 is manufactured by laminating a plurality of obtained wiring boards 8A ₁ , 8A ₂ , 8A ₃ .

In general, when forming the via recess, the resin top is flat because the via top is flat. The thickness of the resin residue depends on the resin physical properties and imprint conditions. However, according to the second embodiment, since the protrusion 65 is disposed so as to surround the peripheral portion of the via top 61, the pressure applied to the protrusion 65 is higher than when the via top is flat. The resin corresponding to the protrusion 65 becomes thinner. Therefore, it is possible to remove the resin residue 88A or part of the easily trapezoidal from the substrate 8A _1.

  The shape of the protrusion 65 formed on the via top 61 of the imprint mold 1A propagates to the surface of the resin, and the surface area of the resin residue increases. Therefore, when ashing is performed, an effect is obtained that the resin residue can be easily removed by increasing the surface area of the resin residue exposed to plasma. Note that the ashing process is not an essential process but an optional process as long as the resin residue is sufficiently small and conduction between the via layer and the wiring of the laminated substrate is ensured.

  In general, when a fine protrusion is provided over the entire top surface of the via to roughen the top surface, when the imprint mold is pressed against the resin for imprinting, the fine protrusion and the resin come into contact with each other at a point. For this reason, the pressure concentrates on the minute protrusions, and the minute protrusions are easily damaged. However, by providing the protrusion 65 only at the peripheral edge of the via top 61 and flattening the other top 61, the pressure applied to the via top 61 is uniform throughout the via top 61 when imprinting. To be distributed. As a result, the imprint mold 1A is not easily broken.

(Other embodiments)
As described above, the present invention has been described according to the first and second embodiments. However, it should not be understood that the description and drawings constituting a part of this disclosure limit the present invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.
In the imprint mold 1 according to the first embodiment, the protrusion 45 is provided on the peripheral portion 42 of the top 41 of the convex portion 4. In addition, like the imprint mold 1B according to the modified example of the embodiment shown in FIG. 23, a base 2B and a convex portion 4B formed on the main surface of the base 2B capable of transferring a predetermined pattern are provided. You may have. A trapezoidal protrusion 45B is formed on the peripheral edge of the top 41B of the protrusion 4B. Thereby, damage to the mold can be prevented.

In the etching of the base material 2 in the first embodiment, the etching selectivity between the base material 2 and the mask material was increased. However, an imprint mold 1B as shown in FIG. 23 is obtained by lowering the etching selection ratio between the base material 2 and the mask material and by setting the anisotropic etching conditions in which a side wall protective film (CF polymer) is formed on the etched side wall. Is manufactured. The imprint mold 1B uses, for example, silicon as the base material 2B and a positive resist (product name “OFPR-800” manufactured by Tokyo Ohka Kogyo Co., Ltd.) having an etching selection ratio of about 5 with silicon as a mask material. the condition of supplying etching gas _{(SF 6 + C 4 F 8} + O 2), can be produced according to the manufacturing method described above.

The cross-sectional shape of the protrusion 45 in FIG. 1B is not limited to a rectangular shape, and may be other shapes. For example, as shown in FIG. 24, a protrusion 45C having a triangular cross section may be used. By setting it as the cross-sectional triangle shape, the cross-sectional shape of the protrusion 85 formed in the bottom part 81 of the recessed part 83 of the wiring board 8 shown in FIG. 13 becomes a triangular shape.
Further, as shown in FIG. 25, a V-shaped cut 48 may be provided at the boundary between the protrusion 45D having a triangular cross section and the top 41D.
Note that the imprint mold 1C in FIG. 24 and the imprint mold 1D in FIG. 25 can be manufactured using the same method as the imprint mold 1B in FIG.

  From the viewpoint of improving the adhesive strength between the wiring board 8 and the wiring 9, the pattern shape of the protrusion 45 formed on the top 41 may be as follows. For example, as shown in FIG. 26, a projection 48 similar to the projection 45 may be formed inside the projection 45. In addition, as shown in FIG. 27, protrusions 45 </ b> F in which a plurality of rectangular protrusions are arranged at substantially equal intervals along the longitudinal direction may be formed on both side edges of the top 41 of the protrusion 4. At that time, as shown in FIG. 28, the protrusions 45G may be formed alternately, or as shown in FIG. 29, the protrusion 45H may be a plurality of protrusions composed of “C” -shaped structural units arranged continuously. Good. Furthermore, as shown in FIG. 30, corrugated protrusions 45 </ b> I that are continuous along the long side direction may be formed on both side edges of the top 41 of the protrusion 4. It is good also as a shape which combined the pattern shown in FIGS.

  In the first embodiment, the protrusion 45 is provided so as to go around the peripheral edge 42 of the top 41. However, depending on the in-plane tendency to which pressure is applied when the imprint mold 1 is pressed against the resin, for example, an elongated protrusion 45J may be provided only in the longitudinal direction of one side edge of the top 41 as shown in FIG. In addition, as shown in FIG. 32, a long and narrow protrusion 45K may be provided only in the short direction.

The cross-sectional shapes of the protrusions 48, 45F,... 45K shown in FIGS. 26 to 32 are not particularly limited, and may be rectangular as shown in FIG. 1 (b), or as shown in FIGS. Such a shape may be used.
As described above, the present invention naturally includes various embodiments not described herein. Therefore, the technical scope of the present invention is defined only by the invention specifying matters according to the scope of claims reasonable from the above description.

DESCRIPTION OF SYMBOLS 1 ... Imprint mold, 2 ... Base material, 4 ... Convex part, 41 ... Top part, 42 ... Peripheral part, 43 ... End part, 45 ... Protrusion,
DESCRIPTION OF SYMBOLS 1A ... Imprint mold, 2A ... Base material, 4A ... Pattern convex part, 6 ... Via convex part, 41A ... Pattern top part, 61 ... Via top part, 45A, 65 ... Protrusion,
1B ... Imprint mold, 2B ... Base material, 4B ... Projection, 41B ... Top,

Claims (5)

A substrate;
A pattern convex portion formed on the main surface of the base material capable of transferring a predetermined pattern; and
Projections are provided on top of the pattern projection,
The imprint mold, wherein the protrusion is formed so as to go around the periphery of the top. A substrate;
A pattern convex portion formed on the main surface of the base material capable of transferring a predetermined pattern; and
Protrusions are provided on at least a part of the peripheral edge of the top of the convex portion for pattern,
An imprint mold, wherein a plurality of the protrusions are formed in parallel to each other. A substrate;
A pattern protrusion formed on the substrate;
A via convex portion formed on the pattern convex portion,
The area of the top of the convex part for via is smaller than the top part of the convex part for pattern, and a protrusion is formed on the top part of the convex part for pattern and the top part of the convex part for via,
The imprint mold, wherein the protrusion is formed so as to go around the periphery of the top. A substrate;
A pattern protrusion formed on the substrate;
A via convex portion formed on the pattern convex portion,
The area of the top part of the via convex part is narrower than the top part of the pattern convex part, and a protrusion is formed on at least a part of each peripheral edge of the top part of the pattern convex part and the top part of the via convex part,
An imprint mold, wherein a plurality of the protrusions are formed in parallel to each other.   The imprint mold according to any one of claims 1 to 4, wherein a height / width of the protrusion in a cross section orthogonal to a longitudinal direction of the protrusion is 0.1 or more and 5 or less.

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