JP5302927B2 - Manufacturing method of multilayer wiring board - Google Patents

Description

  The present invention relates to a method for manufacturing a multilayer wiring board that does not have a core substrate and is formed by alternately laminating resin insulating layers and conductor layers.

In general, a multilayer wiring board in which a build-up layer is formed by alternately laminating resin insulating layers and conductor layers on both sides of a core board is used as a package for mounting electronic components. In the multilayer wiring board, the core board is made of a resin containing glass fiber, for example, and has a role of reinforcing the buildup layer with high rigidity. However, since the core substrate is formed thick, it hinders the miniaturization of the multilayer wiring substrate, and it is necessary to provide a through-hole conductor that electrically connects the build-up layers, so that the wiring length becomes long and high-frequency signal transmission is performed. There is a risk of performance degradation. Therefore, in recent years, a coreless multilayer wiring board having a structure suitable for miniaturization and capable of improving high-frequency signal transmission performance without providing the core board has been proposed (for example, see Patent Documents 1 and 2). ). Such a coreless multilayer wiring board is formed by, for example, forming a build-up layer on a support having two metal foils adhered in a peelable manner on the surface, and then peeling the two metal foils at the peeling interface. Thus, it can be manufactured using a method of separating the buildup layer from the support to obtain a wiring board.

JP 2009-289848 A JP 2007-214427 A

  Generally, in the multilayer wiring board having the above-described structure, the peeling interface between the two metal foils is exposed on the side surface of the outer peripheral portion of the multilayer wiring board. The exposed peeling interface is in a state of being easily peeled off due to factors such as penetration of chemicals used in the manufacturing process, and may become a defective product before the multilayer wiring board is completed, which may reduce the yield. As a countermeasure for this, Patent Document 2 discloses a technique of covering the peeling interface on the side surface of the outer peripheral portion of the multilayer wiring board with a resin layer. However, the strength of the resin is not sufficient for local external force applied in the vicinity of the peeling interface, and it is a problem that the two metal foils cannot be reliably prevented from peeling at the peeling interface during the manufacturing process. there were. In addition, Patent Document 2 discloses a method of using, as an alignment mark, a reference hole formed outside the product area together with the above structure, and the reference hole penetrates the multilayer wiring board in the stacking direction. Also, the substrate area is limited by that amount.

  The present invention has been made to solve these problems, and realizes a method for manufacturing a multilayer wiring board capable of effectively preventing peeling during a lamination process by patterning a release sheet and forming a metal plating layer. For the purpose.

  In order to solve the above problems, the present invention provides a method for producing a multilayer wiring board in which a resin insulating layer and a conductor layer are alternately laminated, and an underlayer and a metal are formed on at least one main surface side of a plate-like support substrate. A sheet disposing step of disposing the layer in a peelable state, and patterning the release sheet composed of the base layer and the metal layer, thereby providing a first on the outer peripheral side of a predetermined effective area of the release sheet. A release sheet processing step for removing the sheet portion, a metal coating step for forming a metal coating layer covering at least a side surface of the release sheet exposed by removing the first sheet portion, the release sheet, and the metal coating A resin material forming step of laminating and forming a resin material covering the upper part of the layer; and a laminating process for alternately forming the conductor layer and the resin insulating layer on the resin material to form a build-up layer And an end face including a release interface of the release sheet on an inner peripheral side from a region where the first sheet portion is removed with respect to the pre-separation laminate including the support base material, the resin material, and the buildup layer. An exposure step for exposing, and a separation step for separating the support substrate from the pre-separation laminate by separating the release sheet at the release interface after the exposure step, and the separation is performed by the separation step. In addition, one or a plurality of multilayer wiring boards are formed using the laminated body after separation.

  According to the method for producing a multilayer wiring board of the present invention, a release sheet comprising a peelable underlayer and a metal layer is disposed on a support base, and the release sheet is patterned to remove the first sheet portion. A laminated body separated from the supporting substrate is obtained by forming a metal coating layer covering at least the side surface of the release sheet and exposing an end face including the release interface of the release sheet, and one or a plurality of multilayer wiring boards It is formed. Therefore, since the build-up layer is formed in a state where the release interface of the release sheet after patterning is covered with a high-strength metal coating layer, the release interface is protected from chemicals during the lamination process, and the release interface is peeled off. It can be surely prevented.

  Although the metal used in the said metal coating process and its formation method are not limited, For example, copper can be used. In this case, as the first metal coating layer, a first coating step of forming an electroless metal (copper) plating layer covering the entire surface of the predetermined effective region, and at least the side surface side of the exposed release sheet are covered. The metal coating layer can be formed by a second coating process for forming an electrolytic metal (copper) plating layer. In addition, as a formation method of a 1st metal coating layer, methods, such as sputtering, may be used.

  In the release sheet processing step, in addition to the first sheet portion, second sheet portions corresponding to a plurality of alignment marks located on the inner peripheral side of the predetermined effective area may be removed. In this case, in the resin material forming step, the resin material is filled in the area where the second sheet portion is removed, and the end surface exposed in the exposing step is removed from the first sheet portion. It is desirable to be located in a region between the region and the region where the second sheet portion is removed.

  In the exposing step, the laminated body before separation is arranged in a laminating direction along a cutting line set in a region between the region from which the first sheet portion is removed and the region from which the second sheet portion is removed. It is desirable to cut. Thereby, after an exposure process, it will be in the state where the said peeling interface of the said peeling sheet was exposed to the side surface of the said laminated body before separation.

  Although the material and structure of the underlayer are not limited, for example, a metal foil can be used. In this case, after the release sheet is covered with a photoresist in the release sheet processing step, the first sheet portion and the second sheet portion may be removed by etching.

  When manufacturing the multilayer wiring board of this invention, you may form the said peeling sheet, the said metal coating layer, the said resin material, and the said buildup layer, respectively on the both surfaces side of the said support base material. Thereby, the two post-separation laminates obtained by separating the support base material in the separation step can be obtained.

  As described above, according to the present invention, when a so-called coreless multilayer wiring board is manufactured, the release sheet and the metal plating layer are strengthened by patterning the release sheet and forming a metal plating layer covering the release interface. It adheres and protects from penetration of chemicals and the like, and can reliably prevent the peeling interface from peeling off during the lamination process. Thereby, the improvement of the yield of a multilayer wiring board is realizable. In addition, according to the present invention, when patterning the release sheet, a plurality of alignment marks can be formed on the surface of the release sheet, and in addition to preventing peeling at the release interface, high accuracy is achieved using the alignment marks after the separation step. Can be positioned.

It is a 1st sectional view explaining the manufacturing method of the multilayer wiring board of a 1st embodiment. It is a 2nd sectional view explaining the manufacturing method of the multilayer wiring board of a 1st embodiment. It is the 3rd sectional structure figure explaining the manufacturing method of the multilayer wiring board of a 1st embodiment, and the plane structure figure corresponding to it. It is a 4th cross-section figure explaining the manufacturing method of the multilayer wiring board of 1st Embodiment. FIG. 10 is a fifth sectional view illustrating the method for manufacturing the multilayer wiring board according to the first embodiment. It is the 6th sectional structure figure explaining the manufacturing method of the multilayer wiring board of a 1st embodiment, and the plane structure figure corresponding to it. It is a 7th cross-section figure explaining the manufacturing method of the multilayer wiring board of 1st Embodiment. FIG. 10 is an eighth sectional view explaining the method for manufacturing the multilayer wiring board according to the first embodiment. FIG. 10 is a ninth cross-sectional structure diagram illustrating the method of manufacturing the multilayer wiring board according to the first embodiment. It is a 10th cross-section figure explaining the manufacturing method of the multilayer wiring board of 1st Embodiment. It is an 11th section view explaining the manufacturing method of the multilayer wiring board of a 1st embodiment. It is a twelfth cross-sectional structure diagram for explaining the manufacturing method of the multilayer wiring board according to the first embodiment. It is a 13th cross-section figure explaining the manufacturing method of the multilayer wiring board of 1st Embodiment. It is a 1st sectional view explaining the manufacturing method of the multilayer wiring board of a 2nd embodiment. It is the 2nd sectional structure figure explaining the manufacturing method of the multilayer wiring board of a 2nd embodiment, and the plane structure figure corresponding to it. It is a 3rd cross-section figure explaining the manufacturing method of the multilayer wiring board of 2nd Embodiment. It is a 4th cross-section figure explaining the manufacturing method of the multilayer wiring board of 2nd Embodiment. It is sectional structure drawing explaining the modification of the manufacturing method of the multilayer wiring board of 2nd Embodiment.

  Hereinafter, two preferred embodiments of the present invention will be described with reference to the drawings. However, each of the first and second embodiments described below is an example to which the technical idea of the present invention is applied, and the present invention is not limited by the contents of these embodiments.

[First Embodiment]
Hereinafter, the manufacturing method of the multilayer wiring board of 1st Embodiment is demonstrated with reference to FIGS. First, as shown in FIG. 1, a plate-like support base material 11 having a copper foil 12 attached on both sides is prepared. The support base 11 is made of, for example, a resin containing glass fiber and has high rigidity. In a state where the release sheet 14 is disposed on the surface of each copper foil 12 of the support base 11 with a prepreg 13 made of, for example, a thermosetting resin, for example, pressure bonding is performed by, for example, vacuum hot pressing (sheet arrangement of the present invention) Process). After the pressure bonding, the outer edge portion is cut and shaped into a predetermined size to obtain the support substrate 11 integrated with the release sheet 14 on the surface. The support base 11 is formed in a rectangular shape having a length of 300 mm and a width of 300 mm, for example. On the other hand, the release sheet 14 has a structure in which two copper foils 14a and 14b having different thicknesses are adhered in a peelable manner. The thickness of the copper foil 14a (the metal layer of the present invention) located outside the support base 11 is larger than the thickness of the copper foil 14b (the base layer of the present invention) located inside.

  Next, as shown in FIG. 2, resist patterns 15 are formed by laminating a photosensitive dry film on each surface of the release sheets 14 on both sides, and exposing and developing. In this resist pattern 15, the outer peripheral portion Po is removed. Subsequently, after the etching is performed on the release sheet 14 in a state where the resist pattern 15 is formed, the resist pattern 15 is removed. As a result, as shown in FIG. 3A, the copper foils 14a and 14b are partially removed in the region immediately below the outer peripheral portion Po in the release sheet 14 (release sheet processing step of the present invention), and the portion The surface of the prepreg 13 is exposed. At this time, the peeling interface between the copper foil 14 a and the copper foil 14 b is exposed on the side surface of the peeling sheet 14.

Here, with reference to FIG. 3B, a planar structure when the stacked body in the state of FIG. 3A is viewed from above will be described. As shown in FIG. 3B, the outer peripheral portion Po from which the copper foils 14a and 14b are removed by a predetermined width is formed within the entire plane of the support base 11, and the inner region is rectangular. It is an effective area A1. The outer peripheral portion Po outside the effective area A1 remains in a later-described laminating process, but is removed by cutting associated with an exposing process described later. On the other hand, the copper foils 14a and 14b remain in the entire area inside the effective area A1.

  Next, as shown in FIG. 4, by applying electroless copper plating to the surface side of the release sheets 14 on both sides, thin copper covering the entire surface and side surfaces of the release sheet 14 and the surface of the prepreg 13 in the outer peripheral portion Po. The electroless copper plating layer 16 that is a film is formed (first coating step of the present invention). Subsequently, as shown in FIG. 5, a resist dry film 17 is laminated on each surface of the electroless copper plating layer 16 on both sides, and exposed and developed to form resist patterns 17 respectively. In the resist pattern 17, the dry film of the rectangular ring-shaped portion sandwiched between the inner peripheral area slightly from the effective area A <b> 1 and the outer peripheral pattern portion 17 a of the outer peripheral portion Po is removed. The electroless copper plating layer 16 corresponds to the first metal coating layer of the present invention.

  Next, as shown in FIG. 6A, with the resist pattern 17 on both sides formed, copper is deposited on the portion where the dry film is removed by applying electrolytic copper plating, and in the rectangular ring-shaped portion A copper plating layer 18 is formed by integrating the lower electroless copper plating layer 16 and the upper electrolytic copper plating layer (second coating step of the present invention). Thereafter, after removing the resist pattern 17, the electroless copper plating layer 16 on the surface of the release sheet 14 and the outer edge portion of the outer peripheral portion Po is removed by etching, and the copper plating protruding slightly upward from the periphery at the rectangular ring-shaped portion Layer 18 remains. Thereby, the peeling interface between the copper foil 14a and the copper foil 14b is completely covered with the copper plating layer 18 on the side surface of the peeling sheet 14, and the peeling interface is protected in the later-described laminating process, and the effect of being difficult to peel off is obtained. is there.

  Here, FIG. 6B shows a plan view when the structure of FIG. 6A is viewed from above. As shown in FIG. 6B, the copper plating layer 18 is exposed so that the copper foil 14a is exposed slightly on the inner peripheral side from the effective area A1 within the range of the entire plane of the support base 11, and surrounds the copper foil 14a. Is formed. On the other hand, the surface of the prepreg 13 is exposed in a thin region of the outer edge portion of the copper plating layer 18 in order to maintain good adhesion when a resin material described later is laminated.

  In addition, the shape and dimension (width and thickness) of the copper plating layer 18 are examples, and can be changed as long as the same effect can be obtained. Moreover, although the example of FIG. 6 has shown the example in which all the peeling interfaces of the side surface of the peeling sheet 14 are covered with the copper plating layer 18, some of the peeling interfaces of the peeling sheet 14 are copper plating layers. Even when not covered with 18, the same effect may be obtained by covering the remaining portion with the copper plating layer 18. Furthermore, the present invention is not limited to the copper plating layer 18, and a metal plating layer using other metals may be formed as long as the same effect can be obtained.

  Next, as shown in FIG. 7, a film-like resin material is laminated from the upper part of the release sheet 14 and cured by pressurizing and heating under vacuum to form a resin material layer 20 (resin material of the present invention). Forming step). As a result, the surface of the release sheet 14 and the surface and side surfaces of the copper plating layer 18 are covered with the resin material layer 20.

  Next, as shown in FIG. 8, a plurality of via holes are formed by laser processing at predetermined positions of the resin material layers 20 on both sides, and after desmear treatment for removing smears in the via holes, electroless copper plating is performed. As a result, a thin copper film is formed on the surface of the resin material layer 20 and the inner surface of the via hole. Next, a photosensitive and insulating dry film is attached to the entire surface of the copper film, and exposure and development are performed to remove the dry film. Next, electrolytic copper plating is performed on the copper film from which the dry film has been removed to deposit copper. Subsequently, the plating resist is stripped using a dedicated stripping solution, and the exposed portion of the thin copper film is etched with a predetermined etching solution, thereby forming the via conductor 40 and the conductor layer 30 in each via hole. Furthermore, a film-like resin material is laminated so as to cover the conductor layers 30 on both sides, and the resin material is cured by pressurizing and heating under vacuum to form the resin insulating layer 21.

  Next, as shown in FIG. 9, a plurality of via holes are formed by laser processing at predetermined positions of the resin insulating layers 21 on both sides, and after the desmear process for removing smears in the via holes, the above-described conventionally known method is performed. Via conductor 41 and conductor layer 31 are simultaneously formed by the semi-additive method. Further, a film-like resin material is laminated so as to cover the conductor layers 31 on both sides, and the resin material is cured by pressurizing and heating under vacuum to form the resin insulating layer 22. The opening 42 is formed by applying laser processing to the pattern portion of the conductor layer 31 in the resin insulating layer 22. As described above, a buildup layer in which the resin insulating layers 21 and 22 and the conductor layers 30 and 31 are alternately formed is formed (a stacking process of the present invention), and a stacked body 10a (a stacked body before separation of the present invention). Is obtained.

  Next, as shown in FIG. 10, the laminated body 10a obtained in the above-described lamination step is shown by a cutting line (indicated by a broken line in the drawing) set slightly on the inner peripheral side from the effective region A1 (FIG. 3B). ) Cut along. As a result, the outer peripheral region including the copper plating layer 18 is removed from the laminate 10a, and the end surface including the release interface of the release sheet 14 is exposed on the side surface (exposing process of the present invention). In this state, the copper foil 14a and the copper foil 14b that are in close contact with each of the upper and lower release sheets 14 are peeled along the peeling interface. As a result, as shown in FIG. 11, the support substrate 11 is separated from the laminate 10a (the separation step of the present invention), and two laminates 10b having the same structure (the separated laminate of the present invention) can be obtained. it can. At this time, the surface of the copper foil 14a appears in each laminated body 10b.

  Next, a resist pattern is formed by laminating a photosensitive dry film on the laminated body 10b obtained in the separation step, and exposing and developing, and after etching the copper foil 14a, the resist pattern is removed. To do. As a result, as shown in FIG. 12, patterning is performed with a predetermined portion of the copper foil 14 a removed, and a pad 50 directly connected to the via conductor 40 is formed. At this point, electrical connection via the conductor layer 31, the via conductor 41, the conductor layer 30, the via conductor 40, and the pad 50 becomes possible.

  Next, as shown in FIG. 13, after forming a solder resist layer 51 by applying and curing a photosensitive epoxy resin on the lower surface side of the resin material layer 20, an opening is formed in the pad 50. Although only FIGS. 12 and 13 are shown as the steps after the separation step, various processes are performed on the laminated body 10b obtained in FIG. 13 according to the use and function of the final multilayer wiring board. be able to.

  For example, a solder ball used for a BGA package may be connected to the pad 50. Further, for example, solder bumps for connecting to the terminals of the semiconductor chip may be connected to the upper opening 42. Further, for example, a through hole penetrating the multilayer body 10b may be formed, and a through hole conductor that can be electrically connected via the through hole may be formed. Note that when a multi-cavity substrate form is assumed, the finally obtained laminate 10b can be cut to obtain a plurality of multilayer wiring boards.

  As described above, according to the manufacturing method of the first embodiment, the structure in which the peeling interface of the release sheet 14 is covered with the copper plating layer 18 is formed prior to the stacking process before the separation process. The release end surface of the release sheet 14 can be protected by the layer 18. At this time, since both the release sheet 14 and the copper plating layer 18 are copper and are firmly bonded in close contact with each other, it is possible to reliably prevent the peeling end face from being peeled off due to penetration of chemicals or the like. In the subsequent separation step, the outer peripheral region including the copper plating layer 18 is removed by cutting, and the release sheet 14 can be easily peeled off at the exposed release interface.

[Second Embodiment]
Next, the manufacturing method of the multilayer wiring board of 2nd Embodiment is demonstrated with reference to FIGS. The feature of the wiring board of the second embodiment is that, in addition to the copper plating layer 18 similar to that of the first embodiment, an alignment mark (described later) used for positioning in each step after the separation step is provided. First, the support base material 11 which has the same structure as FIG. 1 of 1st Embodiment is prepared. Next, as shown in FIG. 14, a photosensitive dry film is laminated on each surface of the release sheets 14 on both sides, and exposed and developed to form resist patterns 15a. Unlike the resist pattern 15 of FIG. 2, the resist pattern 15a has an alignment mark forming portion Pa on the inner peripheral side in addition to the outer peripheral portion Po. Subsequently, after etching the release sheet 14 with the resist pattern 15a formed, the resist pattern 15a is removed.

  As a result, as shown in FIG. 15A, the copper foils 14a and 14b are partially removed in the region immediately below the alignment mark forming portion Pa and the region directly below the outer peripheral portion Po in the release sheet 14 ( The release sheet processing step of the present invention), and the surface of the prepreg 13 at that portion is exposed. In addition, in order to improve the adhesiveness of the peeling sheet 14 and the resin material mentioned later, it is desirable to roughen the surface of the peeling sheet 14 in the etched state.

  Here, with reference to FIG. 15B, a planar structure when the stacked body in the state of FIG. 15A is viewed from above will be described. FIG. 15B shows an effective area A1 in the same range as in FIG. 3B of the first embodiment. In addition to the outer peripheral portion Po outside the effective area A1, the four corners inside the effective area A1 are shown. An alignment mark forming portion Pa is provided, and the copper foils 14a and 14b in that portion are removed. The alignment mark forming portion Pa is formed with an alignment mark AM used for positioning in each step after the separation step. Details will be described later. For positioning in each step before the separation step, an alignment pattern (not shown) separately provided outside the effective area A1 is used.

  Next, as in FIGS. 4 to 6 of the first embodiment, the copper plating layer 18 that covers the release interface of the release sheet 14 is formed by the first and second coating steps. At this time, in order to expose the surface of the prepreg 13 at the alignment mark forming portion Pa in addition to the outer edge portion of the outer peripheral portion Po, it is necessary to remove the electroless copper plating layer 16 by etching. Subsequently, as shown in FIG. 16, the resin material layer 20 is formed by the same method as in FIG. 7 of the first embodiment (resin material forming step of the present invention). As a result, the surface of the release sheet 14 and the surface and side surfaces of the copper plating layer 18 are covered with the resin material layer 20, and the resin material layer 20 is filled in the above-described alignment mark forming portion Pa. Thereby, in addition to the structure similar to 1st Embodiment, the structure of alignment mark AM is formed in the part of alignment mark formation part Pa.

  Next, a laminated body 10a (a laminated body before separation of the present invention) is obtained through the same lamination process as in FIGS. 8 and 9 of the first embodiment, and the laminated body 10a is cut along the same cutting line as in FIG. (Exposure process of the present invention). As a result, as shown in FIG. 17, the support substrate 11 is separated from the laminate 10a (the separation step of the present invention), and two laminated bodies 10b having the same structure (the separated laminate of the present invention) can be obtained. it can. At this time, in each laminated body 10b, the surface of the copper foil 14a on which the structure of the alignment mark AM is formed appears. Subsequent processes are performed in the same manner as in FIGS. 12 and 13 of the first embodiment. In this case, the alignment mark AM is used as a position reference for forming a resist pattern for etching the copper foil 14a in FIG. Even in the subsequent steps, when the alignment mark AM remains, the alignment mark AM can be used as a position reference.

  As described above, according to the manufacturing method of the second embodiment, the structure similar to that of the first embodiment is obtained by the structure of the copper plating layer 18 in the stacking process before the separation process, and the alignment mark AM is obtained after the separation process. Various structures can be formed by positioning using. As shown in FIG. 14, since the positional accuracy of the alignment mark AM is determined at the initial stage, the positional accuracy can be significantly improved as compared with the case where the alignment mark is formed after the stacking process, for example. For example, when the alignment mark AM is not provided at the initial time, it is necessary to form the alignment mark on the upper layer side instead of the lower layer copper foil 14a in the laminated body 10b. Deterioration of position accuracy is unavoidable due to accumulation. In the second embodiment, since the alignment mark AM that is not affected by the positional deviation due to the repeated stacking is formed in advance, high positional accuracy can be realized. Further, in the above exposure step, the copper foil 14a and the resin material layer 20 are bonded to each other at the portion of the alignment mark AM, thereby improving the adhesion between the two, and the release sheet 14 is cut at the time of cutting the laminate 10a or immediately after cutting. Has the effect of making it difficult to peel off at the peeling interface.

  Next, a modification of the method for manufacturing a multilayer wiring board according to the second embodiment will be described with reference to FIG. In this modified example, the semi-additive method is applied to some processes, but in the following, description of processes common to the manufacturing method already described will be omitted, and different processes will be mainly described.

  FIG. 18 is a cross-sectional structure diagram corresponding to FIG. 16 in the present modification. 18 is different from FIG. 16 in that the copper plating layer 70 in the effective area A1 is formed at the same time as the copper plating layer 18 is formed. Therefore, in the resist pattern 17 of FIG. 5, it is necessary to remove the dry film in the region of the copper plating layer 70 in addition to the copper plating layer 18.

  Further, in the subsequent steps, a resin insulation layer and a conductor layer can be laminated on the surface side of the copper plating layer 70 by the same method as described above to form a build-up layer. This modification can also be applied to the multilayer wiring board of the first embodiment in which the alignment mark AM is not provided.

  The contents of the present invention have been specifically described above based on the above embodiments, but the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the invention. . For example, in each of the embodiments described above, the release sheet 14 in which the copper foils 14a and 14b are in close contact with each other has been described. However, the release sheet 14 is formed using various metal materials in close contact with each other without being limited to copper. The thickness can also be changed. In addition, the resin material layer 20, the resin insulating layers 21 and 22, the via conductors 40 and 41, the opening 42, the pad 50, the solder resist layer 51, and other constituent members may be used as long as the effects of the present invention can be obtained. The structure, shape, and forming method can be changed without being limited to the contents disclosed in the above embodiments. In each of the above embodiments, the alignment mark AM is used only for positioning in each step after the separation step. However, in the stacking step before the separation step, the alignment mark AM may be used for positioning and stacking. Is possible. In addition, although the said embodiment demonstrated formation of the 1st coating metal layer by electroless metal plating, you may form by methods, such as not only this method but sputtering.

DESCRIPTION OF SYMBOLS 10a, 10b ... Laminate 11 ... Support base material 12 ... Copper foil 13 ... Prepreg 14 ... Release sheet 14a, 14b ... Copper foil 15, 15a, 17 ... Resist pattern 16 ... Electroless copper plating layer 18, 70 ... Copper plating layer DESCRIPTION OF SYMBOLS 20 ... Resin material layer 21, 22 ... Resin insulation layer 30, 31 ... Conductor layer 40, 41 ... Via conductor 42 ... Opening part 50 ... Pad 51 ... Solder resist layer

Claims (6)

In the method of manufacturing a multilayer wiring board in which resin insulation layers and conductor layers are alternately laminated,
A sheet disposing step of disposing the base layer and the metal layer in a peelable state on at least one main surface side of the plate-shaped support base;
By performing patterning on the release sheet composed of the base layer and the metal layer, the release sheet processing step of removing the first sheet portion on the outer peripheral side of the predetermined effective area of the release sheet;
A metal coating step of forming a metal coating layer covering at least a side surface of the release sheet exposed by removing the first sheet portion;
A resin material forming step of laminating a resin material covering the release sheet and the upper part of the metal coating layer;
A laminating step of alternately laminating the conductor layer and the resin insulating layer on the resin material to form a build-up layer;
An end face including a release interface of the release sheet on the inner peripheral side from an area where the first sheet portion is removed is exposed to the pre-separation laminate including the support base material, the resin material, and the buildup layer. An exposure process;
A separation step of separating the support substrate from the pre-separation laminate by separating the release sheet at the release interface after the exposing step;
And forming one or a plurality of multilayer wiring boards using the post-separation laminate separated in the separation step.   In the metal coating step, a first coating step for forming a first metal coating layer covering the entire surface of the predetermined effective area, and an electrolytic copper plating layer covering at least the side surface side of the exposed release sheet are formed. The method for producing a multilayer wiring board according to claim 1, further comprising a second covering step. In the release sheet processing step, in addition to the first sheet portion, the second sheet portion corresponding to a plurality of alignment marks located on the inner peripheral side of the predetermined effective area is removed,
In the resin material forming step, the resin material is filled in an area where the second sheet portion is removed,
The end face exposed in the exposing step is located in a region between a region where the first sheet portion is removed and a region where the second sheet portion is removed. 3. A method for producing a multilayer wiring board according to 2.   In the exposing step, the laminated body before separation is arranged in a laminating direction along a cutting line set in a region between the region from which the first sheet portion is removed and the region from which the second sheet portion is removed. The method for manufacturing a multilayer wiring board according to claim 3, wherein the release interface of the release sheet is exposed on a side surface of the laminate before separation.   The underlayer is a metal foil, and in the release sheet processing step, after the release sheet is covered with a photoresist, the first sheet portion and the second sheet portion are removed by etching. The manufacturing method of the multilayer wiring board of Claim 3 or 4.   The release sheet, the metal coating layer, the resin material, and the build-up layer are respectively formed on both sides of the support base material, and the two post-separation laminates that separated the support base material in the separation step are The method for producing a multilayer wiring board according to claim 1, wherein the method is obtained.

Images