JP2013211344A - Multilayer wiring board manufacturing method - Google Patents

Abstract

The present invention provides a method for manufacturing a multilayer wiring board in which a residual film is hardly formed in an interlayer connection portion.
A step of preparing an imprint mold having a plate surface on which protrusions are formed and preparing a first wiring board on which wiring including the land is formed; The step of forming the conductive convex member 30, the step of laminating the second insulating sheet 22 on the first wiring board 101, and the conductive convex member 30 are arranged so that the tips of the protrusions 11V and 12V face each other. And a step of pressing the imprint mold 1 against the second insulating sheet 22 such that the tips of the protrusions 11V and 12V penetrate the second insulating sheet 22 and abut or sink into the conductive convex member 30. And a step of releasing the imprint mold 1 from the cured second insulating sheet 22, and a step of filling the grooves 201a to 213a of the second insulating sheet 22 with the conductive material P3. The method of production.
[Selection] FIG. 10A

Description

  The present invention relates to a method for manufacturing a multilayer wiring board.

  In this type of technology, a first recess formed after forming a first interlayer insulating layer covering the first wiring layer formed on the core substrate, pressing a mold against the first interlayer insulating layer, and releasing the mold. There is known a method for manufacturing a capacitor device in which a lower electrode embedded in a first interlayer insulating layer and a first wiring layer are interlayer-connected by plating inside (Patent Document 1).

JP 2006-128309 A

  However, if a recess is formed by pressing a mold against the insulating sheet, a remaining film may be formed at the bottom of the recess. Therefore, if a conductive material is filled in the recess by performing plating or the like in that state, the remaining portion is formed. There is a problem that poor conduction of the interlayer electrode is induced by the influence of the film.

  The problem to be solved by the present invention is to form a concave groove by pressing a mold against an insulating sheet. In the so-called imprint method, a residual film hardly forms in the formed groove, and conduction in an interlayer electrode It is to provide a method for manufacturing a multilayer wiring board that suppresses the occurrence of defects.

  [1] The invention of the present application provides a step of preparing a mold having a plate surface on which a projection formed according to a desired via pattern is formed, and a wiring including a land on one main surface of the first insulating sheet A step of preparing a wiring board on which is formed, a step of forming a conductive convex member on the land, a step of laminating a second insulating sheet covering one main surface side of the wiring board, A step of disposing the mold so that a tip of the protrusion is opposed to the conductive convex member formed on one main surface of the wiring board; and either the second insulating sheet or the mold Or while heating both, the mold is fixed to the second insulation so that the tip of the protrusion of the mold penetrates the second insulating sheet and abuts or sinks into the conductive convex member. And pressing the second insulating sheet on the one main surface of the conductive sheet And a step of releasing the mold from the second insulating sheet, and a step of filling the groove portion corresponding to the via pattern formed in the second insulating sheet with a conductive material. A method of manufacturing a multilayer wiring board.

  [2] In the above invention, the land includes a first metal, and the conductive convex member is a metal different from the first metal, and can form an alloy with the first metal. It can be configured to include a metal.

  [3] In the above invention, the conductive material filled in the groove formed in the second insulating sheet includes a third metal, and the conductive convex member is a metal different from the third metal. Thus, the second metal capable of forming an alloy with the third metal can be included.

  [4] In the above invention, in the step of forming the conductive convex member on the land, the conductive convex member can be formed by discharging conductive ink a plurality of times toward the land. .

  [5] In the above invention, the step of forming the conductive convex member on the land is performed by screen printing a conductive paste using a stencil having an opening at a position corresponding to the land. A convex member can be formed.

  According to the present invention, in the so-called imprinting method, it is possible to manufacture a wiring board in which a residual film hardly occurs in the formed groove portion and the occurrence of poor conduction in the interlayer electrode is suppressed.

It is sectional drawing which shows an example of the metal mold | die of 1st Embodiment. It is process sectional drawing for demonstrating an example of the manufacturing method of the multilayer wiring board which concerns on 1st Embodiment. It is process sectional drawing for demonstrating an example of the manufacturing method of the multilayer wiring board which concerns on 1st Embodiment. It is process sectional drawing for demonstrating an example of the manufacturing method of the multilayer wiring board which concerns on 1st Embodiment. It is process sectional drawing for demonstrating an example of the manufacturing method of the multilayer wiring board which concerns on 1st Embodiment. It is process sectional drawing for demonstrating an example of the manufacturing method of the multilayer wiring board which concerns on 1st Embodiment. It is process sectional drawing for demonstrating an example of the manufacturing method of the multilayer wiring board which concerns on 1st Embodiment. It is process sectional drawing for demonstrating an example of the manufacturing method of the multilayer wiring board which concerns on 1st Embodiment. It is process sectional drawing for demonstrating an example of the manufacturing method of the multilayer wiring board which concerns on 1st Embodiment. It is an enlarged view of A area | region shown to FIG. 9A. It is process sectional drawing for demonstrating an example of the manufacturing method of the multilayer wiring board which concerns on 1st Embodiment. It is an enlarged view of the B area shown in FIG. 10A. It is process sectional drawing for demonstrating an example of the manufacturing method of the multilayer wiring board which concerns on 1st Embodiment. It is an enlarged view of C area | region shown to FIG. 11A. It is process sectional drawing for demonstrating an example of the manufacturing method of the multilayer wiring board which concerns on 1st Embodiment. It is an enlarged view of D field shown in Drawing 12A. It is a figure which shows an example of the multilayer wiring board obtained by the manufacturing method which concerns on 1st Embodiment. It is process sectional drawing for demonstrating an example of the manufacturing method of the multilayer wiring board which concerns on 2nd Embodiment. It is process sectional drawing for demonstrating an example of the manufacturing method of the multilayer wiring board which concerns on 3rd Embodiment. It is process sectional drawing for demonstrating an example of the manufacturing method of the multilayer wiring board which concerns on 4th Embodiment.

<First Embodiment>
Hereinafter, a method for manufacturing a multilayer wiring board according to the first embodiment will be described. The method for manufacturing a multilayer wiring board according to this embodiment includes a softened insulating sheet having a plate surface including a convex portion formed according to a desired wiring pattern and a protruding portion formed according to a desired via pattern. This is a method of manufacturing a so-called imprint type multilayer wiring board in which a conductive material is filled into a wiring groove formed by pressing a metal mold having a mold and a through hole for via. In addition, the groove part in this invention is the concept containing the groove part for wiring in this embodiment, and the through-hole for via | veer.

  In the method for manufacturing a wiring board according to the first embodiment, first, an imprint mold (mold) 1 having a pressing surface 20 pressed against an insulating sheet is prepared. The imprint mold 1 of the present embodiment includes a pressing surface 20 that is pressed against a transfer material (insulating sheet) at the time of clamping, and the pressing surface 20 is formed according to a desired wiring pattern. The plate surface 11 is formed with protrusions 11a to 23a and projections 11V and 12V formed according to a desired via pattern. Although not particularly limited, the plate surface 11 of the present embodiment is formed in the central region of the pressing surface 20 of the imprint mold 1.

  In the example shown in the figure, concave portions 11b to 20b are formed between the convex portions 11a to 23a and the protruding portions 11V and 12V. Further, convex portions 14a, 15a (19a, 20a) are formed around the protrusion 11V (12V), and stepped grooves having different depths can be transferred to the insulating sheet. Although not particularly limited, the lines / spaces of the convex portions 11a to 23a corresponding to the wiring pattern of the imprint mold 1 are 5 [μm] to 15 [μm] / 5 [μm] to 15 [μm], and the height thereof is 5 [μm] to 15 [μm]. The height of the protrusions 11V and 12V formed in accordance with the via pattern for achieving interlayer conduction can be 15 [μm] to 30 [μm]. The height of the protrusions 11V and 12V can be made higher than the thickness of the insulating sheet so that the insulating sheet that is the transfer material can be penetrated. The height of the protrusions 11V and 12V in this example is set to 26 [μm] in accordance with the thickness 25 [μm] of the insulating sheet that is the transfer material.

  The material of the imprint mold 1 is not particularly limited, but silicon, nickel, copper, and diamond-like carbon can be used. In this embodiment, in order to produce the imprint mold 1, a silicon substrate having an oxide film on the surface is prepared, a photosensitive resin is applied to the surface, and the oxide film is patterned by photolithography and wet etching. And by performing dry etching with fluorine gas, the convex portions 11a to 23a corresponding to the wiring pattern are formed. Further, by repeating the above-described steps, the protrusions 11V and 12V corresponding to the via pattern are formed. In addition, the manufacturing method of the imprint mold 1 is not specifically limited, It combines with the process known at the time of application, such as a process using photolithography, a plating process, a polishing process, and a laser irradiation process, and it becomes a desired wiring pattern and via pattern. Accordingly, the imprint mold 1 including the plate surface 11 on which the convex portions 11a to 23a, the projecting portions 11V and 12V, and the concave portions 11b to 20b are formed can be manufactured.

  On the plate surface 11 of the imprint mold 1 of the present embodiment, a release film of a release agent such as a fluororesin is formed from the viewpoint of improving mold release during release. The method for forming the release film is not particularly limited, and the release agent is attached to the plate surface 11 of the imprint mold 1 by dipping the imprint mold 1 in a release agent bath, spin coating, spray coating, vapor deposition, or the like. It can form by the technique to make. The type of the release agent is not particularly limited, and those known at the time of filing such as a fluorine-based silane coupling agent (DURASURF DS-5100 series manufactured by HARVES) can be appropriately employed.

  Using the imprint mold 1, a first wiring board in which wiring including lands is formed on one main surface of the insulating sheet is produced. The first wiring board constitutes a lower layer in the multilayer wiring board.

  As shown in FIG. 2, a first insulating sheet 21 serving as a transfer material is set on the mounting surface of the stage ST of the thermal imprint apparatus. Although it does not specifically limit, the 1st insulating sheet 21 has electrical insulation, For example, liquid crystal polymer (LCP), such as thickness 25 [micrometer], and other thermoplastic resin sheets can be used. In addition, the insulating sheet 21 is made of, for example, a thermoplastic resin material such as polyimide (PI), polyethylene terephthalate (PET), or polyethylene naphthalate (PEN), or a thermosetting resin material such as an epoxy resin. be able to.

  As shown in the drawing, the imprint mold 1 supported by the support 10 is formed by forming a plate surface 11 on which convex portions 11a to 23a, projecting portions 11V and 12V, and groove portions 11b to 20b are formed into a first insulating sheet 21. It arrange | positions so that the one main surface 21a may be opposed.

  Then, as shown in FIG. 3, the stage ST is raised (moved upward along the z direction in the figure) while heating either one or both of the first insulating sheet 21 and the imprint mold 1. Alternatively, the support 10 and the imprint mold 1 are lowered (moved downward along the z direction in the figure), and the imprint mold 1 is pressed against the one main surface 21a of the first insulating sheet 21 (thermal imprint process) ). At this time, the 1st insulating sheet 21 is heated more than the temperature which raise | generates thermal deformation, such as more than a glass transition point or a softening point, according to the characteristic of each resin used as material. Although not particularly limited, in the present embodiment, the first insulating sheet 21 is heated to about 260 [° C.] to 300 [° C.] under a pressure of 0.15 to 4.0 [MPa] during transfer. Can do. In this example, at the time of transfer, the first insulating sheet 21 is heated to 295 [° C.] under a pressure of 3.6 [MPa].

  By this thermal imprint process, the tips of the protrusions 11 </ b> V and 12 </ b> V of the imprint mold 1 reach the vicinity of the other main surface 21 b of the first insulating sheet 21 or penetrate the first insulating sheet 21. From the viewpoint of emphasizing the efficiency when filling the groove formed by the protrusions 11V and 12V with a conductive material, the tips of the protrusions 11V and 12V are not allowed to penetrate the first insulating sheet 21, A groove having a bottom is formed.

  Thereafter, the first insulating sheet 21 is cooled to a predetermined curing temperature (for example, about 60 [° C.]), and the first insulating sheet 21 is cured. In this example, the first insulating sheet 21 is cured by cooling the stage ST to 65 [° C.]. When the first insulating sheet 21 is cured, the support 10 is raised (moved upward along the z direction in the figure) or the stage ST is lowered (moved downward along the z direction in the figure).

  As shown in FIG. 4, when the imprint mold 1 is released from the first insulating sheet 21, wiring corresponding to the convex portions 11 a to 23 a of the plate surface 11 is formed on the one main surface 21 a side of the first insulating sheet 21. Via holes 201V and 202V for via patterns corresponding to the groove portions 201a to 213a for patterns and the protrusion portions 11V and 12V of the printing plate 11 can be formed.

  As shown in FIG. 5, the first conductive material P <b> 1 is filled into the grooves 201 a to 213 a and the through holes 201 </ b> V and 202 </ b> V formed in the first insulating sheet 21. Specifically, sputtering or electroless plating is performed on the first insulating sheet 21 in which the groove portions 201a to 213a and the through holes 201V and 202V are formed, and a seed layer is formed on the inner walls of the groove portions 201a to 213a and the through holes 201V and 202V. Then, the first conductive material P1 is filled in the groove portions 201a to 213a and the through holes 201V and 202V by supplying power to the seed layer and performing electrolytic plating.

  The first conductive material P1 filled in the grooves 201a to 213a and the through holes 201V and 202V by the electrolytic plating process includes a first metal. Although it does not specifically limit as a 1st metal, For example, the metal seed group which consists of gold, silver, copper, platinum, iron, palladium, tungsten, nickel, tantalum, bismuth, lead, indium, tin, zinc, titanium, and aluminum One or two or more metals selected from the above, or an alloy composed of two or more metals selected from the above metal species group can be used. The method of filling the grooves 201a to 213a and the through holes 201V and 202V with the first conductive material P1 is not limited to plating, and a conductive paste containing a conductive material such as metal and a binder is applied to the first insulating sheet 21. Screen printing may be performed.

  After filling the first conductive material P1, the first conductive material P1 protruding from the grooves 201a to 213a and the through holes 201V and 202V is removed by polishing or etching, and wiring and via patterns as shown in FIG. 6 are formed. The formed first wiring board 101 can be obtained. As shown in the figure, wirings 201 a to 213 a including lands L are formed on the one main surface 21 a side of the first insulating sheet 21 of the first wiring board 101. The land L is connected to the vias 201V and 202V and serves as a contact for interlayer conduction.

  Next, the conductive convex member 30 is formed on the land L of the first wiring board 101. The conductive convex member 30 is made of a second conductive material P2 having conductivity. The second conductive material P2 includes a second metal. As the second metal, the same material as the first metal of the first conductive material P1 described above, for example, gold, silver, copper, platinum, iron, palladium, tungsten, nickel, tantalum, bismuth, lead, indium, tin, One or two or more metals selected from a metal species group consisting of zinc, titanium, and aluminum, or an alloy composed of two or more metals selected from the metal species group can be used.

  The second metal contained in the second conductive material P2 constituting the conductive convex member 30 of the present embodiment is a metal different from the first metal contained in the first conductive material P1 constituting the land L. A metal that can form an alloy with the first metal contained in the land L can be selected. The second conductive material P2 constituting the conductive convex member 30 is a second metal having a low melting point, for example, one or more metals selected from the group of tin, bismuth, indium, zinc, antimony and lead. Can be included. The second metal contained in the conductive convex member 30 is different from the first metal contained in the land L. Gold, silver, copper, platinum, iron, palladium, tungsten, nickel, tantalum, bismuth, lead, indium, It may further include one or more metals selected from a metal species group consisting of tin, zinc, titanium and aluminum, or an alloy consisting of two or more metals selected from the metal species group. Although it does not specifically limit, It is preferable that the 2nd metal contained in the 2nd electroconductive material P2 which comprises the electroconductive convex-shaped member 30 in this embodiment contains tin.

  Next, a method for forming the conductive convex member 30 will be described. In the present embodiment, as shown in FIG. 7, the conductive convex member 30 can be formed by ejecting the conductive ink a plurality of times toward the land L using the inkjet printing apparatus 50. The ink jet printing apparatus 50 according to the present embodiment ejects ink droplets containing a functional material toward a predetermined region where the land L of the first insulating sheet 21 is formed, and the conductive convex member 30. This is a so-called inkjet printer that forms a pattern including

  As shown in FIG. 7, the first wiring board 101 is set in the ink jet printing apparatus 50 of the present embodiment so that the nozzles 52 of the ink jet head 51 are positioned opposite the land L arrangement positions. . Then, the control device 54 of the printing apparatus 50 ejects conductive ink a plurality of times from the nozzle 52 toward a predetermined position where the land L is formed. As shown in FIG. 7, the droplet K <b> 1 ejected from the nozzle 52 of the inkjet head 51 flies through the space between the nozzle 52 and the first insulating sheet 21 and faces the nozzle 52. Lands at a predetermined position where the upper land L is formed. A conductive convex member 30 as a conductive functional layer is formed on the land L of the first wiring board 101 by evaporation of the dispersion material (solvent or the like) contained in the ink droplet K2 after landing. Is done.

  In this embodiment, the conductive ink as the second conductive material P2 used for forming the conductive convex member 30 is a fine particle or particle of the second conductive material P2 having a particle diameter of 1 [μm] or less. A material in which nanoparticles of the second conductive material P2 having a diameter of several [μm] to several tens [μm] are dispersed in an organic solvent can be used. When the second conductive material P2 is a metal, a metal inorganic salt or an organometallic complex may be dispersed in an organic solvent. Although not particularly limited, in this embodiment, a mixed ink of nanoparticle-type indium oxide and tin oxide, an ink containing other metal nanoparticles, or a metal ink such as complex-type silver is used as the conductive ink. Can do.

  In the present embodiment, the discharge of the conductive ink (second conductive material P2) onto the land L of the first wiring board 101 is performed at a predetermined cycle. That is, after the conductive ink is discharged, the conductive ink is further discharged after a predetermined time has elapsed. In a predetermined time from discharge to discharge, the laser irradiation device 53 is used to irradiate the laser near the land L, and the vicinity of the land L is heated to evaporate the solvent of the conductive ink that has landed. The droplet K2 landed on the land L is dried and fixed. When the operation of discharging the next conductive ink to the same position is repeated after the conductive ink discharged last time is solidified, the conductive ink moves along the thickness direction (z direction in the drawing) of the first wiring board 101. Thus, it is possible to form the projecting conductive convex member 30 shown in FIG. 7 which is laminated and extended in the z direction according to the number of ejections.

  Although not particularly limited, as shown in FIG. 7, the conductive convex member 30 of this embodiment is a hemisphere or cone having a height from the land L of the first wiring board 101 in the upward direction along the z axis in the figure. It has the shape of a table. The conductive convex member 30 has a shape in which the cross-sectional area along the xy plane in the drawing becomes smaller or the width along the x-axis or y-axis in the drawing becomes smaller from the land L in the upward direction along the z-axis in the drawing. Have. In this way, by reducing the tip of the conductive convex member 30 (the end opposite to the land L), the area in contact with the second insulating sheet 22 laminated in the subsequent process is reduced. The pressing force can be concentrated on the tip of the conductive convex member 30 to be easily embedded in the second insulating sheet 22.

  And the 1st wiring board 101 provided with the electroconductive convex-shaped member 30 is obtained by performing a baking process on the conditions according to the characteristic of electroconductive ink (2nd electroconductive material P2). By performing the firing treatment, the hardness of the conductive convex member 30 can be adjusted. In this case, the resin may not be completely cured but may be in a semi-cured state, and may be completely cured in a later process.

  The formation method of the conductive convex member 30 is not limited to the above-described inkjet printing, and the conductive convex member 30 can be formed by screen printing, plating treatment, or soldering treatment. These methods will be described in the second and subsequent embodiments.

  In addition, before and after the process of forming the conductive convex member 30, the other main surface 21b of the first insulating sheet 21 on the lower side (the lower side along the z direction) of the first wiring board 101 is shown in FIG. Thus, the lower wiring H is formed. The formation method of the lower wiring H is not particularly limited, and a general wiring formation method can be used. For example, a resist is applied to the other main surface (the lower surface in the drawing) of the first insulating sheet 21 of the first wiring board 101, and the resist is patterned according to the lower wiring H using a photolithography technique, and then a plating process is performed. By performing the above, the lower wiring H can be formed.

  Next, as shown in FIG. 8, the second insulating sheet 22 is laminated on the one main surface (101a) side of the first wiring board 101 on which the conductive convex member 30 is formed. One main surface 21 a of the first insulating sheet 21 constituting the first wiring board 101 is in contact with the other main surface 22 b of the second insulating sheet 22. When the second insulating sheet 22 is laminated, a gap is generated between the second insulating sheet 22 and the conductive convex member 30, but this gap disappears by a subsequent thermal imprint process under reduced pressure. Can be made.

  Further, as shown in the figure, the conductive convex member 30 formed on the one main surface 101a of the first wiring board 101 set on the mounting surface of the stage ST, and the protrusions 11V and 12V of the plate surface 11 The imprint mold 1 is arranged so that the tip is opposed.

  Next, as shown in FIG. 9A, the stage ST is raised (moved upward along the z direction in the figure) or the support 10 is lowered (moved downward along the z direction in the figure) to obtain the second insulation. While heating either or both of the conductive sheet 22 and the imprint mold 1, the tips of the protrusions 11 </ b> V and 12 </ b> V of the imprint mold 1 penetrate the second insulating sheet 22 and become the conductive convex member 30. The imprint mold 1 is pressed against the one main surface 22a of the second insulating sheet 22 so as to abut or sink. At this time, the 2nd insulating sheet 22 is heated more than the temperature which raise | generates thermal deformation, such as more than a glass transition point or a softening point, according to the characteristic of each resin used as material. Although not particularly limited, in the present embodiment, the second insulating sheet 22 is heated to about 260 [° C.] to 300 [° C.] under a pressure of 0.15 to 4.0 [MPa] during transfer. Can do. In this example, at the time of transfer, the second insulating sheet 22 is heated to 295 [° C.] under a pressure of 3.6 [MPa].

  In the process of pressing the imprint mold 1 against the one main surface 22 a of the second insulating sheet 22, FIG. 9A shows that the tips of the protrusions 11 a to 23 a corresponding to the wiring pattern are on the one main surface 22 a of the second insulating sheet 22. The abutting state is shown. FIG. 9B shows an enlarged A region including the tips of the protrusions 11V and 12V. At this timing, the tips of the protrusions 11V and 12V penetrate the second insulating sheet 22 and directly contact the top Q1 of the conductive convex member 30, or a thin film (residual film) of the second insulating sheet 22 Is indirectly in contact with the top Q1 of the conductive convex member 30. That is, the tips of the protrusions 11 </ b> V and 12 </ b> V approach or reach the conductive convex member 30 before the printing plate 11 is completely embedded in the second insulating sheet 22.

  Further, as shown in the figure, the conductive convex member 30 has a sectional area along the xy plane in the figure that decreases from the land L in the upward direction along the z axis in the figure, or the x axis or y in the figure. It has a shape with a small width along the axis. That is, the length r2 along the x direction of the top portion Q1 in contact with the tips of the protrusions 11V and 12V is shorter than the length r1 along the x direction of the bottom portion Q2 of the conductive convex member 30 in contact with the land L. The conductive convex member 30 receives the pressing force received from the tips of the projections 11V and 12V at the time of mold clamping at the top Q1 having a relatively small area. The pressing force applied from the tips of the protrusions 11V and 12V is concentrated on the top Q1 of the conductive convex member 30. For this reason, the protrusions 11 </ b> V and 12 </ b> V can easily break through the second insulating sheet 22, and the tips of the protrusions 11 </ b> V and 12 </ b> V can be reliably brought into contact with the top Q <b> 1 of the conductive convex member 30.

  A state where the imprint mold 1 is further pressed is shown in FIGS. 10A and 10B. FIG. 10A shows a state in which the tips of the convex portions 11 a to 23 a corresponding to the wiring pattern penetrate the second insulating sheet 22 and are depressed inside the conductive convex member 30. FIG. 10B shows an enlarged B region including the tips of the protrusions 11V and 12V. In this state, the tips of the protrusions 11V and 12V are depressed from the top Q1 of the conductive convex member 30 into the inside while further pressing the conductive convex member 30 and deforming the conductive convex member 30. ing. The tips of the protrusions 11 </ b> V and 12 </ b> V penetrate the second insulating sheet 22 and completely penetrate the second insulating sheet 22. That is, the tips of the protrusions 11 </ b> V and 12 </ b> V are in direct contact with the top portion Q <b> 1 of the conductive convex member 30 without the second insulating sheet 22 interposed. Further, the top Q1 of the conductive convex member 30 is further pushed down from the position shown in FIG. 9B (moves in the downward direction along the z axis in the figure) to form a top Q1 ′ shown in FIG. 10B.

  Thus, in this embodiment, since the conductive convex member 30 is provided on the land L where the interlayer conduction is performed, if the protrusions 11V and 12V are pressed toward the land L during mold clamping, the protrusion The portions 11V and 12V can easily penetrate the second insulating sheet 22 while deforming the conductive convex member 30, and can completely penetrate the second insulating sheet 22 without forming a residual film. Since no residual film is formed on the land L, it is necessary to perform a treatment for damaging the wiring board such as plasma irradiation, laser irradiation, and chemical etching in order to remove the resin residual film remaining at the bottoms of the through holes 201V and 202V. Therefore, a high-quality multilayer wiring board can be produced.

  Thereafter, the second insulating sheet 22 is cooled to a predetermined curing temperature (for example, about 60 [° C.]), and the second insulating sheet 22 is cured. In this example, the second insulating sheet 22 is cured by cooling the stage ST to 65 [° C.]. When the second insulating sheet 22 is cured, the support 10 is raised (moved upward along the z direction in the figure) or the stage ST is lowered (moved downward along the z direction in the figure).

  As shown in FIG. 11A, when the imprint mold 1 is released from the second insulating sheet 22, wiring corresponding to the convex portions 11 a to 23 a of the plate surface 11 is formed on the one main surface 22 a side of the second insulating sheet 22. Via holes 201V and 202V for via patterns corresponding to the groove portions 201a to 213a for patterns and the protrusion portions 11V and 12V of the printing plate 11 can be formed. FIG. 11B is an enlarged view of a region C shown in FIG. 11A. As shown in FIG. 11B, the bottoms of the through holes 201V and 202V formed by pressing the protrusions 11V and 12V are formed by the top Q3 (corresponding to Q1 ′) of the conductive convex member 30. That is, the second conductive material P2 has already been formed at the bottoms of the through holes 201V and 202V. Since the conductive material is formed on the bottoms of the through holes 201V and 202V, a plating layer can be easily formed in a plating process to be performed later.

  Subsequently, as shown in FIG. 12A, the third conductive material P3 is filled into the grooves 201a to 213a and the through holes 201V and 202V formed in the second insulating sheet 22 shown in FIG. 11A. Specifically, sputtering or electroless plating is performed on the second insulating sheet 22 in which the groove portions 201a to 213a and the through holes 201V and 202V are formed, and a seed layer is formed on the inner walls of the groove portions 201a to 213a and the through holes 201V and 202V. Then, by supplying power to the seed layer and performing electroplating, the grooves 201a to 213a and the through holes 201V and 202V are filled with the third conductive material P3, and the via 40 is formed.

  The third conductive material P3 filled in the grooves 201a to 213a and the through holes 201V and 202V by the electrolytic plating process includes a third metal. As the third metal, for example, a kind selected from a metal species group consisting of gold, silver, copper, platinum, iron, palladium, tungsten, nickel, tantalum, bismuth, lead, indium, tin, zinc, titanium, and aluminum. Alternatively, an alloy composed of two or more metals or two or more metals selected from the above metal species group can be used. The method of filling the grooves 201a to 213a and the through holes 201V and 202V with the third conductive material P3 is not limited to plating, and a conductive paste containing a conductive material such as metal and a binder is applied to the second insulating sheet 22. Screen printing may be performed.

  The second metal contained in the second conductive material P2 constituting the conductive convex member 30 described above is a metal different from the third metal contained in the third conductive material P3 constituting the via 40. A metal capable of forming an alloy with the third metal can be selected. The third metal contained in the via 40 can be the same metal as the first metal contained in the land L.

  After filling the third conductive material P3, the laminated first wiring board 101 and second wiring board 102 are heated and pressed along the laminating direction (z direction in the figure). The third conductive material P3 is cured by this hot pressing process. Although not particularly limited, the temperature of the hot pressing process in the present embodiment is such that the first metal and the second metal, and the second metal and the third metal can form an alloy. It can be determined experimentally according to the melting point of the alloy obtained from the second metal and / or the third metal.

  When the first and second insulating sheets 21 and 22 are thermosetting resins, the first and second insulating sheets 21 and 22, the conductive convex member 30, and the via 40 are completely cured. Until the first and second insulating sheets 21 and 22 are softened and are in a state of being bonded together, and then cooled in the oven, then the first and second insulating sheets 21 and 22 22, the conductive convex member 30 and the via 40 may be completely cured.

  FIG. 12B shows the D region shown in FIG. 12A in an enlarged manner. As shown in FIG. 12B, the third metal contained in the third conductive material P3 constituting the via 40 is alloyed with the second metal contained in the second conductive material P2 constituting the conductive convex member 30. When the metal species can be formed, an alloy layer (alloy site) 31 of the third metal and the second metal is formed at the interface between the via 40 and the conductive convex member 30. Further, as described above, the first metal contained in the first conductive material P1 constituting the land L is alloyed with the second metal contained in the second conductive material P2 constituting the conductive convex member 30. When the metal species can be formed, an alloy layer (alloy site) 32 of the first metal and the second metal is formed at the interface between the land L and the conductive convex member 30. In addition, as each 1st-3rd metal increases the quantity of the low melting point metal containing tin, bismuth, indium, zinc, antimony, and lead, the land L and the conductive convex member 30 at the time of hot press are increased. Since the amount of the alloy formed at the interface and the interface between the conductive convex member 30 and the tip of the via 40 can be increased, the bonding strength of each interface can be further improved and the electrical reliability can be improved. it can.

  Thus, according to the method for manufacturing a multilayer wiring board of the present embodiment, the first metal and the third metal are disposed between the land L including the first metal and the via 40 including the third metal (or the first metal). Since the conductive convex member 30 containing the second metal capable of forming an alloy with these is interposed, the first metal of the land L and the first conductive convex member 30 of the land L are formed by hot pressing. The second metal, the third metal of the via 40, and the second metal of the conductive convex member 30 can react to form a region containing an alloy. Thereby, the land L, the conductive convex member 30, and the conductive convex member 30 and the via 40 can be chemically and firmly bonded. As a result, a multilayer wiring board with high connection reliability can be manufactured.

  Although not particularly limited, the first metal and / or the third metal may be a low-resistance metal such as copper, silver, or gold, and the second metal may be tin. Since an alloy of Cu—Sn, Ag—Sn, and Au—Sn is formed between the land L and the conductive convex member 30 and between the conductive convex member 30 and the via 40, A multilayer wiring board having excellent characteristics and a strong structure can be manufactured.

  By repeating the above-described step of forming the conductive convex member 30, the step of laminating the second insulating sheet 22, the step of pressing the imprint mold 1, and the step of curing the second insulating sheet 22, a desired A multilayer wiring board having a number of stacked layers can be produced. FIG. 13 is a diagram illustrating an example of the multilayer wiring board 200. The lower wiring H is formed by a subtractive method, a semi-additive method, or the like after laminating a plurality of wiring boards, polishing the other main surface (lower side surface in the figure) of the wiring board and exposing the conductor. be able to. Of course, a backside wiring board may be prepared to achieve interlayer conduction. In the present embodiment, the imprint mold 1 used to form the wiring pattern grooves 201a to 213a and the through holes 201V and 202V on one main surface of the first wiring board 101, and the second wiring board 102 The imprint mold 1 pressed against the one principal surface 22a of the insulating sheet 102 may be the same or different imprint molds.

Second Embodiment
A method of manufacturing the multilayer wiring board according to the second embodiment will be described with reference to FIG. The method for manufacturing a multilayer wiring board according to the second embodiment is characterized in that the conductive convex member 30 is formed using a screen printing device 60. The method for manufacturing a multilayer wiring board according to the present embodiment is basically the same as the method for manufacturing the multilayer wiring board according to the first embodiment. Therefore, here, different points will be mainly described, and the common points will be described in the first embodiment. The explanation in is incorporated.

  As shown in FIG. 14A, a stencil 61 having an opening 62 at a position corresponding to the land L is prepared, and the stencil 61 is arranged so that the position of the opening 62 faces the land L of the first wiring board 101. Set. As shown in FIG. 14B, the conductive paste S is stretched along the xy plane in the drawing with the squeegee 63, and the opening 62 is filled with the conductive paste S as shown in FIG.

  This conductive paste S corresponds to the second conductive material P2 of the first embodiment and contains a second metal. Although not particularly limited, in this example, the conductive paste S includes tin, particles of a metal having low electrical resistance such as nickel, gold, silver, zinc, aluminum, iron, and tungsten, and bismuth, indium, lead, and the like. A metal particle having a low melting point and an organic component such as an epoxy resin, an acrylic resin, or a urethane resin can be used. Furthermore, as the conductive paste S, an anisotropic conductive paste in which fine conductive particles such as nickel, solder alloy, carbon, and plated resin balls are dispersed in a thermosetting resin or a thermoplastic resin can be used. . As the conductive paste S, a solder paste containing an alloy of Cu—Sn, Ag—Sn, and Au—Sn can be used.

  After firing, the stencil 61 is removed, and the conductive convex member 30 is formed on the land L of the first wiring board 101 shown in FIG. The state shown in FIG. 14D corresponds to the state shown in FIG. 7 of the first embodiment. Other processes are the same as those in the first embodiment.

<Third Embodiment>
The manufacturing method of the multilayer wiring board of 3rd Embodiment is demonstrated based on FIG. The method of manufacturing a multilayer wiring board according to the third embodiment is characterized in that the conductive convex member 30 is formed using a solder ball forming apparatus. The method for manufacturing a multilayer wiring board according to the present embodiment is basically the same as the method for manufacturing the multilayer wiring board according to the first embodiment. Therefore, here, different points will be mainly described, and the common points will be described in the first embodiment. The explanation in is incorporated.

  As shown in FIG. 15A, a flux layer X is formed on the lands of the first wiring board 101, and solder balls are formed on the flux layer X as shown in FIG. A baking process is performed. This solder ball corresponds to the second conductive material P2 of the first embodiment and contains a second metal. The state shown in FIG. 15B corresponds to the state shown in FIG. 7 of the first embodiment. Other processes are the same as those in the first embodiment.

<Fourth embodiment>
The manufacturing method of the multilayer wiring board of 4th Embodiment is demonstrated based on FIG. The method for manufacturing a multilayer wiring board according to the fourth embodiment is characterized in that the conductive convex member 30 is formed using a plating apparatus. The method for manufacturing a multilayer wiring board according to the present embodiment is basically the same as the method for manufacturing the multilayer wiring board according to the first embodiment. Therefore, here, different points will be mainly described, and the common points will be described in the first embodiment. The explanation in is incorporated.

  As shown in FIG. 16A, a resist 70 having an opening 71 at a position corresponding to the land L is formed by using a photolithography technique known at the time of filing. In this state, a plating process known at the time of application is performed to form a plating layer M in the opening 71 as shown in FIG. The plating layer M corresponds to the second conductive material P2 of the first embodiment and includes a second metal. Finally, the mask 70 is removed as shown in FIG. 6C, and the conductive convex member 30 is formed on the land L of the first wiring board 101 shown in FIG. The state shown in FIG. 16C corresponds to the state shown in FIG. 7 of the first embodiment. Other processes are the same as those in the first embodiment.

  The embodiment described above is described for facilitating understanding of the present invention, and is not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Imprint mold, metal mold | die 10 ... Support body 11 ... Plate surface 11a-23a ... Convex part 11V, 12V ... Protrusion part 11b-20b ... Concave ST ... Stage 20 ... Pressing surface 21 ... 1st insulating sheet 22 ... 2nd Insulating sheet 21a ... One main surface of insulating sheet 21b ... Other main surface of insulating sheet 201a to 213a ... Groove, wiring 201V, 202V ... Through hole, via P ... Conductive material P1 ... First conductive material, P2 ... 2nd conductive material, P3 ... 3rd conductive material L ... Land H ... Lower wiring 30 ... Conductive convex member r1, r2 ... Diameter (of conductive convex member) 40 ... (Interlayer conduction) Via 50 ... (Inkjet type) printing device 51 ... inkjet head 52 ... nozzle 53 ... laser irradiation device K1, K2 ... ink droplet 60 ... screen printing device 61 ... stencil (screen plate)
62 ... Opening 63 ... Squeegee S ... Conductive paste X ... Flux 70 ... (Plating) resist M ... Plating layer 71 ... Opening
DESCRIPTION OF SYMBOLS 101 ... 1st wiring board 102 ... 2nd wiring board 101-104 ... Laminated wiring board 200 ... Multilayer wiring board

Claims (5)

A step of preparing a mold having a printing plate on which protrusions formed according to a desired via pattern are formed;
A step of preparing a wiring board in which wiring including lands is formed on one main surface of the first insulating sheet;
Forming a conductive convex member on the land;
Laminating a second insulating sheet covering one main surface side of the wiring board;
Placing the mold such that the tip of the protrusion is opposed to the conductive convex member formed on one main surface of the wiring board;
While either one or both of the second insulating sheet and the mold is heated, the tip of the protrusion of the mold penetrates the second insulating sheet and contacts the conductive convex member Or a step of pressing the mold against one main surface of the second insulating sheet so as to be depressed,
Curing the second insulating sheet;
Releasing the mold from the second insulating sheet;
And a step of filling a groove portion corresponding to the via pattern formed in the second insulating sheet with a conductive material. The land includes a first metal;
The multilayer wiring according to claim 1, wherein the conductive convex member includes a second metal that is different from the first metal and is capable of forming an alloy with the first metal. A manufacturing method of a board. The conductive material filled in the groove formed in the second insulating sheet includes a third metal,
The said conductive convex-shaped member is a metal different from the said 3rd metal, Comprising: The 2nd metal which can form an alloy with the said 3rd metal is included, The Claim 1 or 2 characterized by the above-mentioned. A method of manufacturing a multilayer wiring board. The step of forming a conductive convex member on the land,
The method for manufacturing a multilayer wiring board according to claim 1, wherein the conductive convex member is formed by discharging conductive ink a plurality of times toward the land. The step of forming a conductive convex member on the land,
The conductive convex member is formed by screen-printing a conductive paste using a stencil having an opening at a position corresponding to the land, according to any one of claims 1 to 3. The manufacturing method of the multilayer wiring board as described.

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