JP2011044523A - Resin multilayer substrate and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin multilayer substrate such that sufficient adhesion between a first resin layer and a second resin layer is secured and the thickness of the second resin layer is made thin, and a method of manufacturing the resin multilayer substrate. <P>SOLUTION: The resin multilayer substrate 1 includes a component built-in resin layer (first resin layer) 20 in which an electronic component is incorporated, and a thin resin layer (second resin layer) 30 laminated on one surface of the component built-in layer (first resin layer) 20. The resin multilayer substrate further includes a via conductor (first via conductor) 23 provided to the component built-in layer 20 and having one end extended to the one surface of the component built-in layer 20, and a recessed part 27 formed on the one surface of the component built-in layer 20. The thin resin layer 30 is laminated on the one surface of the component built-in layer 20 along the shape of the recessed part 27. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a resin multilayer substrate including at least two resin layers and via conductors, and a method for producing the resin multilayer substrate.

  In recent years, with the mounting of high-density electronic components, resin multilayer substrates in which conductive paste of multiple via holes is increased and via conductors are connected to each resin layer are used for mounting electronic components. ing. For example, Patent Document 1 discloses a resin multilayer substrate in which via conductors provided in each resin layer are connected, and a method of manufacturing the resin multilayer substrate.

  The resin multilayer substrate disclosed in Patent Document 1 and the method of manufacturing the resin multilayer substrate include blind via holes in a wiring substrate (first resin layer) in which a carrier on which an IC is mounted is molded with a resin and cured. Then, a desmear process is performed to form a through via hole. A conductive paste is filled in each of the blind via hole and the through via hole, and a thin resin layer (second resin layer) is laminated on the wiring board so that the blind via hole and the through via hole are connected to each other. A copper foil is laminated on the thin resin layer, the thin resin layer and the conductive paste are cured, and the copper foil is patterned to form a surface electrode.

JP 2003-124380 A

  However, in the resin multilayer substrate disclosed in Patent Document 1, the copper foil is laminated on the thin resin layer after the through via hole is formed. Therefore, when a strong pressure is applied to the copper foil, the copper is formed at the position where the through via hole is formed. The foil may be deformed, and sufficient pressure cannot be applied to the copper foil. For this reason, there is a problem that sufficient adhesion may not be ensured between the wiring board and the thin resin layer and between the thin resin layer and the copper foil.

  Further, in the resin multilayer substrate disclosed in Patent Document 1, since it is necessary to provide a thin resin layer between the wiring substrate and the copper foil, the thickness of the resin multilayer substrate is increased by the thickness of the thin resin layer. There was a problem of becoming.

  The present invention has been made in view of the above circumstances, and is a resin multilayer substrate capable of sufficiently securing the adhesion between the first resin layer and the second resin layer and reducing the thickness of the second resin layer. And it aims at providing the manufacturing method of this resin multilayer substrate.

  In order to achieve the above object, a resin multilayer substrate according to a first aspect of the present invention is a resin comprising a first resin layer containing an electronic component and a second resin layer laminated on one surface of the first resin layer. In the multilayer substrate, the first resin layer is provided on the first resin layer, and one end of the first resin layer reaches the one surface of the first resin layer, and a concave portion formed on the one surface of the first resin layer, The second resin layer is laminated on the one surface of the first resin layer along the shape of the recess.

  In the resin multilayer substrate according to the second invention, in the first invention, the shape of the recess is a hole shape and / or a slit shape.

  In the resin multilayer substrate according to a third aspect of the present invention, in the first or second aspect, the concave portion is formed on the one surface of the first resin layer located immediately above the built-in electronic component.

  According to a fourth aspect of the present invention, there is provided the resin multilayer substrate according to any one of the first to third aspects, wherein the resin multilayer substrate is located other than the depth of the recess located immediately above the built-in electronic component. The depth of the recess is increased.

  In the resin multilayer substrate according to a fifth aspect of the present invention, in the first or second aspect, the recess is formed around the first via conductor.

  According to a sixth aspect of the present invention, there is provided the resin multilayer substrate according to any one of the first to fifth aspects, further comprising a base layer having a wiring pattern formed on at least one surface thereof, wherein the base having the wiring pattern formed thereon is provided. The first resin layer and the second resin layer are sequentially laminated on one surface of the layer, and the wiring pattern and the first via conductor are electrically connected.

  According to a seventh aspect of the present invention, in the resin multilayer substrate according to any one of the first to fifth aspects of the present invention, a surface of the first resin layer opposite to a surface on which the second resin layer is laminated is provided. A wiring pattern formed; and an electronic component built in the first resin layer and mounted on the wiring pattern.

  According to an eighth aspect of the present invention, in the resin multilayer substrate according to the sixth aspect, an electronic component is mounted on at least one surface of the base layer, and the mounted electronic component is built in the first resin layer.

  A resin multilayer substrate according to a ninth aspect of the present invention is the resin multilayer substrate according to any one of the first to eighth aspects, wherein the second resin layer has a surface opposite to the surface laminated on the first resin layer. A surface electrode formed on the second resin layer, one end of the surface electrode, and the other end electrically connected to the first via conductor, the second via conductor, The surface electrode is electrically connected to an electrode formed on a mother substrate on which the resin multilayer substrate is placed.

  In order to achieve the above object, a method for producing a resin multilayer substrate according to a tenth aspect of the present invention includes a first resin layer containing electronic components, a second resin layer laminated on one surface of the first resin layer, A first step of forming a first via hole having at least an opening on the one surface of the cured first resin layer, and a recess on the one surface of the first resin layer. Forming a second via hole in the uncured second resin layer, and connecting the first via hole and the second via hole along the shape of the recess. A third step of laminating the second resin layer on the one surface of the one resin layer, and a first via conductor and a second via conductor are formed by filling the first via hole and the second via hole with a conductive paste. 4 steps and the conductive pace And a fifth step of the second resin layer in the cured state.

  According to an eleventh aspect of the present invention, there is provided the method for producing a resin multilayer substrate according to the tenth aspect, wherein the first via hole formed in the first step and the concave portion formed in the second step are continuous with the same apparatus. Formed.

  In the first invention, a recess is formed on one surface of the first resin layer to which one end of the first via conductor reaches, and the second resin layer is laminated on one surface of the first resin layer along the shape of the recess. The contact area between the first resin layer and the second resin layer is increased by the amount of the formed recess, and the adhesion between the first resin layer and the second resin layer can be improved. Moreover, the thickness of the second resin layer can be reduced by the amount embedded in the recess.

  In the second invention, since the shape of the recess is a hole shape and / or a slit shape, it can be easily formed using a laser device or the like for forming a via hole, and the manufacturing cost can be reduced. .

  In the third invention, since the recess is formed on one surface of the first resin layer located immediately above the built-in electronic component, the second resin layer and the second resin layer are formed at a position directly above the built-in electronic component. Adhesion with the resin layer can be improved.

  In the fourth aspect of the invention, the depth of the recessed portion located in the other portion is deeper than the depth of the recessed portion located immediately above the built-in electronic component, so the portion of the second resin layer that fills the recessed portion Can be secured, and the thickness of the second resin layer can be further reduced.

  In the fifth aspect of the invention, since the recess is formed around the first via conductor, the first resin layer and the second resin layer around the first via conductor where the second resin layer is easily separated from the first resin layer. Adhesion with can be improved.

  In the sixth invention, the first resin layer and the second resin layer are sequentially laminated on one surface of the base layer on which the wiring pattern is formed, and the wiring pattern and the first via conductor are electrically connected. Electronic components can be mounted on the wiring pattern, and the electronic components can be mounted at high density.

  In the seventh invention, the wiring pattern formed on the surface of the first resin layer opposite to the surface on which the second resin layer is laminated, and the first resin layer are embedded in the first resin layer and mounted on the wiring pattern. Since a certain electronic component is provided, the electronic component can be further densely mounted.

  In the eighth invention, since the electronic component is mounted on at least one surface of the base layer, and the mounted electronic component is built in the first resin layer, the electronic component can be mounted on both surfaces of the base layer, Electronic components can be mounted at high density.

  In the ninth invention, since the surface electrode formed on the second resin layer is electrically connected to the electrode formed on the mother substrate on which the resin multilayer substrate is placed, the resin multilayer substrate, the electronic component, etc. Can be mounted on a mother board at high density.

  In the tenth aspect of the invention, a first via hole having at least an opening is formed on one surface of the cured first resin layer, a recess is formed on one surface of the first resin layer, and the second resin layer is uncured. Since the second resin layer is laminated on one surface of the first resin layer along the shape of the recess so that the two via holes are formed and the first via hole and the second via hole are connected, the first resin layer and the second resin The contact area with the layer is increased by the amount of the formed recess, and the adhesion between the first resin layer and the second resin layer can be improved. Moreover, the thickness of the second resin layer can be reduced by the amount embedded in the recess.

  In the eleventh aspect of the invention, the first via hole formed in the first step and the recess formed in the second step are continuously formed in the same device, so that separate devices can be used without introducing a new device. Therefore, the manufacturing cost can be reduced.

  In the resin multilayer substrate and the method for manufacturing the resin multilayer substrate according to the present invention, a recess is formed in one surface of the first resin layer reaching one end of the first via conductor, and the second resin layer is formed along the shape of the recess. Since it is laminated on one surface of the resin layer, the contact area between the first resin layer and the second resin layer is widened by the formed recess, and the adhesion between the first resin layer and the second resin layer is increased. Can be improved. Moreover, the thickness of the second resin layer can be reduced by the amount embedded in the recess.

It is sectional drawing which shows the structure of the resin multilayer substrate which concerns on Embodiment 1 of this invention. It is sectional drawing for demonstrating the manufacturing method of the resin multilayer substrate which concerns on Embodiment 1 of this invention. It is sectional drawing for demonstrating the manufacturing method of the resin multilayer substrate which concerns on Embodiment 1 of this invention. It is sectional drawing for demonstrating the manufacturing method of the resin multilayer substrate which concerns on Embodiment 1 of this invention. It is sectional drawing for demonstrating the manufacturing method of the resin multilayer substrate which concerns on Embodiment 1 of this invention. It is sectional drawing for demonstrating the manufacturing method of the resin multilayer substrate which concerns on Embodiment 1 of this invention. It is sectional drawing for demonstrating the manufacturing method of the resin multilayer substrate which concerns on Embodiment 1 of this invention. It is sectional drawing for demonstrating the manufacturing method of the resin multilayer substrate which concerns on Embodiment 1 of this invention. It is sectional drawing for demonstrating the manufacturing method of the resin multilayer substrate which concerns on Embodiment 1 of this invention. It is sectional drawing which shows another structure of the resin multilayer substrate which concerns on Embodiment 1 of this invention. It is sectional drawing which shows the structure of the resin multilayer substrate based on Embodiment 1 of this invention mounted in the mother board | substrate. It is sectional drawing which shows the structure of the resin multilayer board | substrate which concerns on Embodiment 1 of this invention which is not provided with a base layer. It is a top view of the component resin layer which concerns on Embodiment 2 of this invention. It is a top view of another component resin layer which concerns on Embodiment 2 of this invention.

  Hereinafter, the resin multilayer substrate and the method for producing the resin multilayer substrate in the embodiments of the present invention will be specifically described with reference to the drawings. The following embodiments do not limit the invention described in the claims, and all combinations of characteristic items described in the embodiments are essential to the solution. It goes without saying that it is not limited.

(Embodiment 1)
FIG. 1 is a cross-sectional view showing a configuration of a resin multilayer substrate according to Embodiment 1 of the present invention. As shown in FIG. 1, the resin multilayer substrate 1 according to the first embodiment includes a base layer 10, a component built-in layer (first resin layer) 20, and a thin resin layer (second resin layer) 30 stacked in this order. is there. The base layer 10 is made of ceramic, glass, epoxy resin or the like, and wiring patterns 11a and 11b are formed on both surfaces. On the surface of the base layer 10 on which the wiring pattern 11a is formed, the IC element 12 is disposed on the surface on which the wiring pattern 11b is formed. ). The electronic components 13 and 13 are surface-mount components, such as a chip capacitor and a resistor. The wiring pattern 11 a is electrically connected to the wiring pattern 11 b via via conductors 14, 14, 14 formed in the base layer 10. Further, a resist layer 15 is formed at predetermined positions of the wiring patterns 11a and 11b for the purpose of ensuring insulation.

  The component built-in layer 20 is laminated on the surface of the base layer 10 on which the wiring pattern 11b is formed, and incorporates the mounted electronic components 13 and 13 and part of the wiring pattern 11b. The component built-in layer 20 is made of a thermosetting resin such as an epoxy resin, and has a thickness that prevents at least the electronic components 13 and 13 from being exposed to the outside. The component built-in layer 20 is formed with via conductors (first via conductors) 23, 23 in which conductive holes 22 are filled in via holes 21, 21 having openings on the surface on which the thin resin layer 30 is laminated. It is. One end of the via conductors 23 and 23 reaches one surface of the component built-in layer 20 on which the thin resin layer 30 is laminated, and the other end is electrically connected to the wiring pattern 11b. Further, the component built-in layer 20 has a plurality of recesses 27, 27,... Formed on one surface of the component built-in layer 20 located immediately above the built-in electronic components 13, 13. The recesses 27, 27,... Are shallower than the via holes 21 and 21 and do not reach the built-in electronic components 13. In addition, the cross-sectional shape of the concave portions 27, 27,... Is not limited to the wedge shape, and may be a semicircular shape, a square shape, or the like.

  The thin resin layer 30 is sufficiently thinner than the component built-in layer 20 and is laminated so that the component built-in layer 20 is sandwiched between the base layer 10. The thin resin layer 30 is made of a thermosetting resin such as an epoxy resin. In the thin resin layer 30, via conductors (second via conductors) 33, 33 in which the via holes 31, 31 are filled with the conductive paste 22 are formed. The via conductors 33, 33 have a surface electrode 34 formed on the surface of the thin resin layer 30 opposite to the surface laminated on the component built-in layer 20 at one end and the via conductors 23, 23 at the other end. Are electrically connected to each other. Further, since the thin resin layer 30 is laminated on one surface of the component built-in layer 20 along the shape of the recess 27, the contact area between the component built-in layer 20 and the thin resin layer 30 forms the recess 27. Compared with the case where there is not, the adhesiveness between the component built-in layer 20 and the thin resin layer 30 can be improved. Furthermore, the thickness of the thin resin layer 30 can be reduced by the amount embedded in the recess. Note that a resist layer 36 is also formed at a predetermined position of the surface electrode 34 for the purpose of ensuring insulation.

  2-9 is sectional drawing for demonstrating the manufacturing method of the resin multilayer substrate 1 which concerns on Embodiment 1 of this invention. 2 is a cross-sectional view of the base layer 10, FIG. 3 is a state in which the electronic components 13, 13 are mounted on the base layer 10, and FIG. 4 is a state in which the component built-in layer 20 is stacked on the base layer 10. FIG. 5 shows a state in which via holes 21 and 21 and recesses 27, 27,... Are formed in the component built-in layer 20, respectively. 6 shows a state in which the thin resin layer 30 in which the via holes 31 and 31 are formed is laminated on the component built-in layer 20, and FIG. 7 shows a state in which the via holes 21, 21, 31 and 31 are filled with the conductive paste 22. 8 shows a state in which a metal foil is attached to the thin resin layer 30, and FIG. 9 shows a state in which the surface electrode 34 is formed by patterning the metal foil.

  As shown in FIG. 2, wiring patterns 11 a and 11 b are formed on both surfaces of the base layer 10, and via conductors for electrically connecting the wiring patterns 11 a and 11 b to the base layer 10. 14, 14, and 14 are formed. The wiring patterns 11a and 11b can be formed by patterning a metal layer (for example, Cu layer) formed on each surface of the base layer 10 into a predetermined pattern using photolithography. Note that the resist layer 15 formed on the wiring patterns 11a and 11b can also be formed using photolithography in the same manner as the wiring patterns 11a and 11b.

  Next, as shown in FIG. 3, the electronic components 13 and 13 are mounted on the base layer 10 on which the wiring pattern 11b is formed with a conductive bonding material (not shown) such as solder. Thereafter, as shown in FIG. 4, the component built-in layer 20 is formed on the mounting surface of the electronic components 13 and 13 of the base layer 10 so as to incorporate a part of the electronic components 13 and 13 and the wiring pattern 11 b. The component built-in layer 20 is formed by covering the mounting surface of the electronic components 13 and 13 of the base layer 10 with an uncured resin sheet and pressing the resin sheet into a cured state. The component built-in layer 20 is preferably in a cured state before the thin resin layer 30 is laminated.

  Next, as shown in FIG. 5, bottomed via holes 21 and 21 are formed at predetermined positions of the component built-in layer 20. The via holes 21 and 21 can be formed by irradiating a predetermined position of the component built-in layer 20 with laser light from the component built-in layer 20 side to the base layer 10 side. The cross-sectional shapes of the via holes 21 and 21 are tapered so that the diameter decreases as they approach the base layer 10 because the laser beam is irradiated from the component built-in layer 20 side. The via holes 21 and 21 are formed until reaching the wiring pattern 11b.

  Further, a plurality of concave portions 27, 27,... Are formed on one surface of the component built-in layer 20 located immediately above the built-in electronic components 13, 13. The recesses 27, 27,... Can be formed by irradiating a predetermined position with laser light from the component built-in layer 20 side to the base layer 10 side. The cross-sectional shape of the recesses 27, 27,... Is shallower than the depth of the via holes 21, 21 and has a wedge shape. When the laser beam for forming the recesses 27, 27,... Is irradiated from the same device as the laser beam for forming the via holes 21, 21, the laser beam output is reduced after forming the via holes 21, 21, The recesses 27, 27,... Can be formed continuously. When the laser light for forming the recesses 27, 27,... Is irradiated from a device different from the laser light for forming the via holes 21, 21, the recesses 27, 27,.・ Formation can be performed in parallel.

  In addition, the method of forming the via holes 21 and 21 and the recesses 27, 27,... Is not limited to the method using laser light, and may be a method of mechanically scraping the component built-in layer 20 or the like. . However, when the method of forming the via holes 21, 21 and the recesses 27, 27,... With laser light is adopted, the residues in the via holes 21, 21 and the recesses 27, 27,. It is necessary to perform a desmear treatment in which these are dissolved and removed with a mixed acid or the like. Since the desmear process is a wet process, it is necessary to dry the resin multilayer substrate 1 after the desmear process.

  Next, as shown in FIG. 6, the thin resin layer 30 in which the via holes 31 and 31 are formed is laminated on the component built-in layer 20 so that the via holes 21 and 21 and the via holes 31 and 31 are connected. The thin resin layer 30 is made of a thermosetting resin such as an epoxy resin, and is in an uncured state when it is laminated on the component built-in layer 20. Therefore, the thin resin layer 30 can be filled in the recess 27 by deforming along the recess 27. The diameters of the upper end side and the lower end side of the via hole 31 are formed to be smaller than the diameter of the upper end side of the via hole 21.

  Next, as shown in FIG. 7, the conductive paste 22 is filled in the via holes 21, 21, 31, 31. The conductive paste 22 is a paste obtained by mixing a metal powder such as silver, copper, or tin with a solvent or the like.

  Next, as shown in FIG. 8, a metal foil 40 (for example, copper foil) is attached to the thin resin layer 30. The metal foil 40 is attached to the uncured thin resin layer 30 and then the thin resin layer 30 is cured to strongly bond the metal foil 40 and the component built-in layer 20. That is, the thin resin layer 30 functions as a bonding layer that bonds the metal foil 40 and the component built-in layer 20 together.

  Next, as shown in FIG. 9, the surface electrode 34 is formed by patterning the metal foil 40 into a predetermined pattern using photolithography. Thereafter, as shown in FIG. 1, a resist layer 36 is formed at a predetermined position of the surface electrode 34 using photolithography, and an IC is formed on the base layer 10 on the wiring pattern 11 a side using a conductive bonding material such as solder. The element 12 is mounted.

  As described above, the resin multilayer substrate 1 according to the first embodiment forms the recesses 27, 27,... On the one surface of the component built-in layer 20 reaching one end of the via conductors 23, 23, thereby forming a thin resin layer 30 is laminated on one surface of the component built-in layer 20 along the shape of the recesses 27, 27,..., So that the contact area between the component built-in layer 20 and the thin resin layer 30 is formed. , 27,..., And the adhesion between the component built-in layer 20 and the thin resin layer 30 can be improved. Further, since it is necessary to form the via hole 31 in advance, the thin resin layer 30 needs to have a thickness sufficient to ensure handling properties at that time, but after the lamination, the thickness is as much as the portion embedded in the recess 27. Can be made thinner.

  Further, the resin multilayer substrate 1 according to the first embodiment has recesses 27, 27,... Located on one surface of the component built-in layer 20 directly above the built-in electronic components 13, 13. However, the present invention is not limited to the case, and the other recessed portion 27 may be formed. Compared with the depth of the concave portion 27 formed on one surface of the component built-in layer 20 located immediately above the built-in electronic components 13, the depth of the concave portion 27 located elsewhere can be increased. FIG. 10 is a cross-sectional view showing another configuration of the resin multilayer substrate according to Embodiment 1 of the present invention. As shown in FIG. 10, the depth of the concave portion 27a formed on one surface of the component built-in layer 20 other than the one surface of the component built-in layer 20 positioned other than immediately above the built-in electronic components 13 and 13 is embedded. It is deeper than the depth of the concave portion 27b formed on one surface of the component built-in layer 20 located immediately above the electronic components 13, 13. Therefore, many portions of the thin resin layer 30 filling the concave portions 27a can be secured, and the thickness of the thin resin layer 30 can be further reduced. Since other configurations are the same as those of the resin multilayer substrate 1 shown in FIG. 1, the same components are denoted by the same reference numerals, and detailed description thereof is omitted.

  In addition, the resin multilayer substrate 1 according to the first embodiment can be mounted on a mother substrate. FIG. 11 is a cross-sectional view showing the configuration of the resin multilayer substrate 1 according to Embodiment 1 of the present invention mounted on a mother substrate. As shown in FIG. 11, the resin multilayer substrate 1 is mounted on the mother substrate 42 by forming solder bumps 41 on the surface electrodes 34 and connecting the solder bumps 41 to the electrodes 43 formed on the mother substrate 42. Has been. Here, the mother substrate 41 is a substrate for mounting a plurality of resin multilayer substrates 1 and electronic components and electrically connecting them.

  Further, the resin multilayer substrate 1 according to the first embodiment is not limited to the one provided with the base layer 10 as shown in FIG. 1, and may be the resin multilayer substrate 1 not provided with the base layer 10. . FIG. 12 is a cross-sectional view showing the configuration of the resin multilayer substrate 1 according to Embodiment 1 of the present invention that does not include the base layer 10. As shown in FIG. 12, the resin multilayer substrate 1 has a component built-in layer 20 and a thin resin layer 30 laminated in order, and does not include the base layer 10. The component built-in layer 20 includes a wiring pattern 25 on the surface opposite to the surface on which the thin resin layer 30 is laminated, and incorporates the electronic components 13 and 13 mounted on the wiring pattern 25. Since other configurations are the same as those of the resin multilayer substrate 1 shown in FIG. 1, the same components are denoted by the same reference numerals, and detailed description thereof is omitted.

(Embodiment 2)
FIG. 13 is a plan view of the component built-in layer 20 according to Embodiment 2 of the present invention. In particular, FIG. 13 is a plan view of the component built-in layer 20 before the thin resin layer 30 is attached. As shown in FIG. 13, the resin multilayer substrate 1 has via holes 21 and 21 formed on one surface of the component built-in layer 20. When the component built-in layer 20 and the thin resin layer 30 are bonded together, the portion where the via holes 21 and 21 are formed is the portion where the component built-in layer 20 and the thin resin layer 30 are not bonded, and this portion Adhesiveness between the component built-in layer 20 and the thin resin layer 30 in the vicinity decreases. In particular, when the via holes 21 and 21 are formed in the vicinity of the four corners of the resin multilayer substrate 1 where the thin resin layer 30 easily peels from the component built-in layer 20, the adhesion between the component built-in layer 20 and the thin resin layer 30 is improved. There was a need.

  Therefore, in the resin multilayer substrate 1 according to the second embodiment, adhesion between the component built-in layer 20 and the thin resin layer 30 is formed by forming a recess 27 on one surface of the component built-in layer 20 in the vicinity of the via holes 21 and 21. To improve. In particular, by forming the recesses 27 near the via holes 21 and 21 formed in the vicinity of the four corners of the resin multilayer substrate 1, the thin resin layer 30 does not peel from the component built-in layer 20 at the four corners of the resin multilayer substrate 1. The adhesion between the component built-in layer 20 and the thin resin layer 30 is improved.

  As described above, in the resin multilayer substrate 1 according to the second embodiment, the concave portion 27 is formed on one surface of the component built-in layer 20 in the vicinity of the via holes 21 and 21 (via conductors 23 and 23), so that the component built-in layer is formed. Thus, the adhesion between the component built-in layer 20 around the via conductors 23 and 23 and the thin resin layer 30 can be improved. That is, in the resin multilayer substrate 1 according to the second embodiment, the concave portion 27 is formed in a portion where the adhesion between the component built-in layer 20 and the thin resin layer 30 needs to be improved, so that the component built-in layer 20 The thin resin layer 30 can be made difficult to peel off.

  The shape of the recess 27 formed on one surface of the component built-in layer 20 in the vicinity of the via holes 21 and 21 is not limited to the hole shape, and may be a slit shape. FIG. 14 is a plan view of another component built-in layer 20 according to Embodiment 2 of the present invention. FIG. 14 is also a plan view of the component built-in layer 20 before the thin resin layer 30 is attached. As shown in FIG. 14, the resin multilayer substrate 1 is formed with lattice-like slits 28 passing through the vicinity of via holes 21 and 21 formed on one surface of the component built-in layer 20. By changing the shape of the recess 27 from the hole shape to the slit shape, the contact area between the component built-in layer 20 and the thin resin layer 30 can be increased, and the component built-in layer 20 and the thin resin layer 30 are in close contact with each other. Further improve the sex. Further, the portion of the thin resin layer 30 that fills the slit 28 is larger than the portion of the thin resin layer 30 that fills the hole-shaped recess 27, and the thickness of the thin resin layer 30 can be further reduced. Further, since the slit 28 is formed up to the edge of the component built-in layer 20, it is possible to prevent air clogging when the thin resin layer 30 is laminated.

DESCRIPTION OF SYMBOLS 1 Resin multilayer substrate 10 Base layer 20 Component built-in layer 30 Thin resin layer 11a, 11b Wiring pattern 12 IC element 13 Electronic component 14, 23, 33 Via conductor 15, 36 Resist layer 21, 31 Via hole 22 Conductive paste 27 Recess 28 Slit 34 Surface electrode

Claims (11)

In a resin multilayer substrate comprising a first resin layer containing an electronic component and a second resin layer laminated on one surface of the first resin layer,
A first via conductor that is provided in the first resin layer and has one end reaching the one surface of the first resin layer;
A recess formed on the one surface of the first resin layer,
The resin multilayer substrate, wherein the second resin layer is laminated on the one surface of the first resin layer along the shape of the recess.   The resin multilayer substrate according to claim 1, wherein the shape of the recess is a hole shape and / or a slit shape.   3. The resin multilayer substrate according to claim 1, wherein the recess is formed on the one surface of the first resin layer located immediately above the built-in electronic component.   4. The depth of the concave portion located at another position is made deeper than the depth of the concave portion located immediately above the built-in electronic component. 5. The resin multilayer substrate according to one item.   The resin multilayer substrate according to claim 1, wherein the concave portion is formed around the first via conductor. A base layer having a wiring pattern formed on at least one surface;
The first resin layer and the second resin layer are sequentially laminated on one surface of the base layer on which the wiring pattern is formed, and the wiring pattern and the first via conductor are electrically connected. The resin multilayer substrate according to any one of claims 1 to 5, wherein: A wiring pattern formed on the surface of the first resin layer opposite to the surface on which the second resin layer is laminated;
6. The resin multilayer substrate according to claim 1, further comprising: an electronic component built in the first resin layer and mounted on the wiring pattern.   The resin multilayer substrate according to claim 6, wherein an electronic component is mounted on at least one surface of the base layer, and the mounted electronic component is built in the first resin layer. A surface electrode formed on the surface of the second resin layer opposite to the surface laminated on the first resin layer;
A second via conductor provided on the second resin layer, one end of the surface electrode and the other end electrically connected to the first via conductor;
The resin multilayer substrate according to claim 1, wherein the surface electrode is electrically connected to an electrode formed on a mother substrate on which the resin multilayer substrate is placed. . In a method of manufacturing a resin multilayer substrate comprising a first resin layer containing an electronic component and a second resin layer laminated on one surface of the first resin layer,
A first step of forming a first via hole having at least an opening on the one surface of the cured first resin layer;
A second step of forming a recess in the one surface of the first resin layer;
A second via hole is formed in the second resin layer in an uncured state, and the first via hole is formed on the one surface of the first resin layer along the shape of the recess so that the first via hole and the second via hole are connected to each other. A third step of laminating the second resin layer;
A fourth step of filling the first via hole and the second via hole with a conductive paste to form a first via conductor and a second via conductor;
And a fifth step of bringing the conductive paste and the second resin layer into a cured state.   11. The resin multilayer substrate according to claim 10, wherein the first via hole formed in the first step and the concave portion formed in the second step are continuously formed in the same apparatus. Production method.

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