Manufacturing method of wiring boards

Abstract

Providing high-quality wiring boards. [Solution] The method for manufacturing a wiring board according to the embodiment includes forming a laminate 1P and dividing the laminate 1P into a plurality of wiring boards. Forming the laminate 1P includes forming a first build-up portion 10 on the first surface 100f of a base substrate 100 having a first surface 100f and a second surface 100s opposite to the first surface 100f, so as to include one or more first insulating layers 11. Dividing the laminate 1P includes forming grooves GB in the first build-up portion 10 in the thickness direction of the first build-up portion 10 with a dicing blade DB, and after forming the grooves GB, cutting the laminate 1P along the grooves GB with a dicing blade DB.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a wiring board.

Background Art

[0002] Patent Document 1 discloses a method for manufacturing a wiring board including cutting a substrate having a metal layer and a resin layer formed on both surfaces (one surface and the other surface) of a glass substrate into a plurality of individual wiring boards along a dicing line using a dicing blade.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the method for manufacturing a wiring board disclosed in Patent Document 1, in the step of cutting the substrate with a dicing blade, there is a possibility of occurrence of defects such as cracks in the glass substrate and peeling of the resin layer from the glass substrate.

Means for Solving the Problems

[0005] The method for manufacturing a wiring board of the present invention includes forming a laminate and dividing the laminate into a plurality of wiring boards. Forming the laminate includes forming a first build-up portion including one or more first insulating layers on a first surface of a base substrate having a first surface and a second surface opposite to the first surface. Dividing the laminate includes forming a groove portion in the first build-up portion in a thickness direction of the first build-up portion with a dicing blade, and after forming the groove portion, cutting the laminate along the groove portion with the dicing blade.

[0006] According to embodiments of the present invention, in the process of dividing a laminate into multiple wiring boards, high-quality wiring boards can be manufactured in which the occurrence of cracks in the glass substrate and delamination in the build-up portion are suppressed. [Brief explanation of the drawing]

[0007] [Figure 1A] A cross-sectional view showing an example of a wiring board manufactured by the wiring board manufacturing method of the embodiment. [Figure 1B] A cross-sectional view showing another example of a wiring board manufactured by the wiring board manufacturing method of the embodiment. [Figure 1C] A cross-sectional view showing yet another example of a wiring board manufactured by the wiring board manufacturing method of the embodiment. [Figure 2A] A cross-sectional view showing an example of a manufacturing method for a wiring board according to an embodiment. [Figure 2B] A cross-sectional view showing an example of a manufacturing method for a wiring board according to an embodiment. [Figure 2C] A cross-sectional view showing an example of a manufacturing method for a wiring board according to an embodiment. [Figure 2D] A cross-sectional view showing an example of a manufacturing method for a wiring board according to an embodiment. [Figure 3A] A cross-sectional view showing an example of a manufacturing method for a wiring board according to an embodiment. [Figure 3B] A cross-sectional view showing an example of a manufacturing method for a wiring board according to an embodiment. [Figure 3C] A cross-sectional view showing an example of a manufacturing method for a wiring board according to an embodiment. [Figure 3D] A cross-sectional view showing an example of a manufacturing method for a wiring board according to an embodiment. [Modes for carrying out the invention]

[0008] A method for manufacturing a wiring board according to an embodiment of the present invention will be described with reference to the drawings. Figure 1A shows a cross-sectional view of wiring board 1, which is an example of a wiring board manufactured by the manufacturing method of the embodiment. Note that wiring board 1 is merely an example of a wiring board manufactured by the manufacturing method of the embodiment. For example, the laminated structure of the manufactured wiring board and the number of insulating layers included in the wiring board may differ from the laminated structure of wiring board 1 in Figure 1A and the number of insulating layers included in wiring board 1. In addition, the manufactured wiring board may include any number of insulating layers and conductive layers in addition to the insulating layers and conductive layers of wiring board 1 shown in Figure 1A, and may not include all of the insulating layers and conductive layers of wiring board 1 shown in Figure 1A. Furthermore, in the drawings referenced in the following description, certain parts may be enlarged to facilitate understanding of the disclosed embodiment, and the size and length of each component may not be depicted in the exact proportions between them.

[0009] The wiring board 1 is composed of a base substrate 100 and build-up sections 10 and 20, which are made up of insulating layers and conductive layers alternately laminated on both sides of the base substrate 100. The wiring board 1 has two main surfaces perpendicular to its thickness direction: one surface 1F and the other surface 1S opposite to the first surface 1F. The wiring board 1 has a side surface DS that extends in its thickness direction. Furthermore, the side surface DS consists of a first side surface GS and a second side surface CS.

[0010] The base substrate 100 included in the wiring board 1 has a first surface 100f and a second surface 100s opposite to the first surface 100f. On the first surface 100f of the base substrate 100, a first insulating layer 11 and a first conductor layer 12 are alternately laminated to form a first build-up section 10. On the second surface 100s of the base substrate 100, a second insulating layer 21 and a second conductor layer 22 are alternately laminated to form a second build-up section 20.

[0011] In addition, with regard to the description of the wiring board manufactured by the manufacturing method of the embodiment, in the description of the components of the wiring board 1, the side closer to the base substrate 100 is referred to as "bottom," "lower side," "inside," or "inner side," and the side further from the base substrate 100 is referred to as "top," "upper side," "outside," or "outer side." The surface of each element constituting the wiring board 1 that faces the base substrate 100 is also referred to as the "bottom surface," and the surface that faces away from the base substrate 100 is also referred to as the "top surface." Furthermore, the direction in which the insulating layer and conductor layer of the wiring board 1 are laminated, that is, the thickness direction of the wiring board 1, is also referred to as the "Z direction," and "plan view" means viewing the object with a line of sight parallel to the Z direction.

[0012] The base substrate 100 has a through conductor 101 that penetrates the base substrate 100 in the thickness direction. The first insulating layer 11 constituting the first build-up section 10 has a first via conductor 13 that penetrates the first insulating layer 11 in the thickness direction and connects conductors (either the first conductor layers 12 to each other, or the first conductor layer 12 to the through conductor 101) that are in contact with the upper and lower surfaces of the first insulating layer 11. The second insulating layer 21 constituting the second build-up section 20 has a second via conductor 23 that penetrates the second insulating layer 21 in the thickness direction and connects conductors (either the second conductor layers 22 to each other, or the second conductor layer 22 to the through conductor 101) that are in contact with the upper and lower surfaces of the second insulating layer 21.

[0013] The through-conductor 101 is formed by filling a through-hole 101a formed in the base substrate 100 with a conductor. In the illustrated example, the end face of the through-conductor 101 in the Z direction is formed substantially flush with the first surface 100f and the second surface 100s of the base substrate 100. The first via conductor 13 is formed by filling a through-hole 13a formed in the first insulating layer 11 with a conductor. The first via conductor 13 is integrally formed with the first conductor layer 12 that is in contact with the upper surface of the first insulating layer 11 through which the first via conductor 13 passes. The second via conductor 23 is formed by filling a through-hole 23a formed in the second insulating layer 21 with a conductor. The second via conductor 23 is integrally formed with the second conductor layer 22 that is in contact with the upper surface of the second insulating layer 21 through which the second via conductor 23 passes.

[0014] The base substrate included in the wiring board manufactured by the manufacturing method of the embodiment may be a glass substrate. The base substrate 100 of the wiring board 1 shown in Figure 1A is formed using a glass substrate. Examples of glass materials that can be used for the glass substrate constituting the base substrate 100 include soda-lime glass, aluminosilicate glass, borosilicate glass, fluoroglass, chalcogen glass, alkali-free glass, or quartz glass. Alternatively, organic glass such as acrylic glass may be used. These glasses may contain magnesium, calcium, manganese, aluminum, lead, iron, chromium, potassium, sulfur, antimony, boron, etc. as additives. Furthermore, the base substrate included in the wiring board may also be a substrate containing materials other than glass, such as a silicon substrate, ceramic substrate, or resin substrate.

[0015] The first insulating layer 11 and the second insulating layer 21 are formed using any insulating resin. Examples of insulating resins include thermosetting resins such as epoxy resin, bismaleimide triazine resin (BT resin), or phenolic resin, and thermoplastic resins such as fluororesin, liquid crystal polymer (LCP), fluoroethylene fluorine (PTFE) resin, polyester (PE) resin, and modified polyimide (MPI) resin. The first insulating layer 11 and the second insulating layer 21 may contain inorganic fillers (not shown) such as silica and alumina. The first insulating layer 11 and the second insulating layer 21 may also contain reinforcing materials (core materials) such as glass fibers or aramid fibers.

[0016] Examples of the conductors that constitute the first conductor layer 12, the second conductor layer 22, the first via conductor 13, the second via conductor 23, and the through conductor 101 include any metal such as copper or nickel, and preferably copper is used. In the example shown in FIG. 1A, the first conductor layer 12, the second conductor layer 22, the first via conductor 13, the second via conductor 23, and the through conductor 101 are each shown as a single layer, but may be configured in a multilayer structure. The first conductor layer 12, the second conductor layer 22, the first via conductor 13, the second via conductor 23, and the through conductor 101 may have a multilayer structure including, for example, a metal foil layer (preferably a copper foil), a metal film layer (preferably a copper film formed by electroless plating or sputtering), and a plating film layer (preferably an electrolytic copper plating film). For example, the first conductor layer 12, the second conductor layer 22, the first via conductor 13, the second via conductor 23, and the through conductor 101 may have a two-layer structure including a metal film layer and a plating film layer.

[0017] Each conductor layer (the first conductor layer 12, the second conductor layer 22) constituting the wiring substrate 1 is patterned so as to have a predetermined conductor pattern. The first conductor layer 12 constituting one surface 1F of the wiring substrate 1 is formed in a pattern having a plurality of conductor pads 12fp. The second conductor layer 22 constituting the other surface 1S of the wiring substrate 1 is formed in a pattern having a plurality of conductor pads 22sp.

[0018] In FIG. 1A, the through conductor 101 is shown as having substantially the same inner diameter throughout the thickness direction of the base substrate 100. The through conductor 101 may have a shape that tapers toward the central portion of the thickness of the base substrate 100 from the first surface 100f side and the second surface 100s side. Although the term "tapered" is used for convenience, the shape of the through conductor 101 in plan view is not necessarily limited to a circular shape. The "diameter" means the straight-line distance between the two most separated points on the outer edge of the object in plan view, and "tapered" means that the straight-line distance becomes smaller.

[0019] The first build-up section 10 constituting the wiring board 1 includes a solder resist layer 10Rf formed on its outermost surface using, for example, a photosensitive polyimide resin or epoxy resin. An opening 10Rfa is formed in the solder resist layer 10Rf, and the surface of the conductor pad 12fp is exposed through the opening 10Rfa. That is, one side 1F of the wiring board 1 includes the surface of the solder resist layer 10Rf and the surface of the conductor pad 12fp exposed through the opening 10Rfa. The second build-up section 20 constituting the wiring board 1 includes a solder resist layer 20Rs formed on its outermost surface using, for example, a photosensitive polyimide resin or epoxy resin. An opening 20Rsa is formed in the solder resist layer 20Rs, and the surface of the conductor pad 22sp is exposed through the opening 20Rsa. That is, the other side 1S of the wiring board 1 includes the surface of the solder resist layer 20Rs and the surface of the conductor pad 22sp exposed through the opening 20Rsa.

[0020] One side 1F of the wiring board 1 shown in Figure 1A is configured as a component mounting surface to which external electronic components are connected, and the conductor pad 12fp can be connected to the connection pads of external electronic components when the wiring board 1 is used. The other side 1S of the wiring board 1 may be a connection surface that is connected to an external board, for example, when the wiring board 1 is mounted on an external board, such as the motherboard of any electrical device. When the wiring board 1 is used, the conductor pad 22sp can be connected to the connection pads of the external board.

[0021] The single wiring board 1 shown in Figure 1A is formed by dividing a laminate containing multiple wiring boards 1 into individual wiring boards 1, as will be described in more detail later with reference to Figures 3A to 3D. The side surface DS extending in the thickness direction of the wiring board 1 is the cut surface that is exposed when the laminate is cut and divided into individual wiring boards 1. In the wiring board 1, the side surface DS consists of a first side surface GS and a second side surface CS. The first side surface GS is the cut surface of the first build-up portion 10. The second side surface CS is the cut surface of the base substrate 100 and the second build-up portion 20. In the wiring board 1, the first side surface GS and the second side surface CS are formed substantially flush. That is, the first side surface GS and the second side surface CS overlap in a plan view. This makes it less likely for delamination to occur between the base substrate 100 and the build-up portion of the wiring board 1.

[0022] In plan view, each wiring board 1 has, for example, a rectangular shape, and in the laminate described above, multiple wiring boards 1 are connected in a grid pattern. As will be described later, in the process of dividing the laminate in which multiple wiring boards 1 are connected into individual wiring boards 1, localized stress concentration on the surface (first surface 100f) of the base substrate 100 can be avoided. Therefore, the wiring board 1 is manufactured as a high-quality wiring board in which delamination between the base substrate 100 and the first build-up portion 10, and the occurrence of cracks in the base substrate 100 are suppressed.

[0023] As described above, the wiring board 1 shown in Figure 1A is merely one example of a wiring board manufactured by the manufacturing method of the embodiment. Furthermore, the laminated structure of the manufactured wiring board, as well as the number of insulating layers and conductive layers included in the wiring board, may differ from the wiring board 1 in Figure 1A. In Figure 1A, the wiring board 1 has a configuration in which a first build-up section 10 and a second build-up section 20, each consisting of three sets of insulating layers and conductive layers, are formed on the first surface 100f and the second surface 100s of the base substrate 100, respectively. However, the wiring board manufactured by the manufacturing method of the embodiment is not necessarily limited to this configuration.

[0024] In the wiring board manufactured by the manufacturing method of the embodiment, for example, as shown in Figure 1B, the number of sets of the first insulating layer 11 and the first conductor layer 12 constituting the first build-up section 10 may differ from the number of sets of the second insulating layer 21 and the second conductor layer 22 constituting the second build-up section 20. In wiring board 1α, similar to wiring board 1, the base substrate 100 includes through holes 101a and through conductors 101. In wiring board 1α, the first insulating layer 11 (insulating layer 110) laminated on the first surface 100f of the base substrate 100 includes through holes 13a and the first via conductor 13. As shown in Figure 1B, the first side surface GS of wiring board 1α is a cross-section of the first build-up section 10, similar to wiring board 1. The second side surface CS of wiring board 1α is a cross-section of the base substrate 100 and the second build-up section 20. In the wiring board 1α, the first side surface GS and the second side surface CS are formed to be substantially flush. This makes it less likely for the base substrate 100 of the wiring board 1α to peel off from the first build-up portion 10.

[0025] Furthermore, as shown in Figure 1C, the second build-up portion 20 does not need to be formed on the second surface 100s of the base substrate 100. In this case, one main surface 1S of the wiring board 1β becomes the second surface 100s of the base substrate 100. In the wiring board 1β, the base substrate 100 does not need to include through holes 101a and through conductors 101. Similarly, in the wiring board 1β, the first insulating layer 11 (insulating layer 110) laminated on the first surface 100f of the base substrate 100 does not need to include through holes 13a and the first via conductor 13. As shown in Figure 1C, the first side surface GS of the wiring board 1β is the cross-section of the first build-up portion 10, similar to the wiring board 1. The second side surface CS of the wiring board 1β is the cross-section of the base substrate 100. In the wiring board 1β as well, the first side surface GS and the second side surface CS are formed substantially flush. This makes it less likely for the base substrate 100 of the wiring board 1β to peel off from the first build-up section 10.

[0026] Next, with reference to Figures 2A to 2D and Figures 3A to 3D, the manufacturing method of the wiring board according to the embodiment will be explained, using the case where the wiring board 1 shown in Figure 1A is manufactured as an example. Note that, unless otherwise specified, each component formed in the wiring board manufacturing method described below may be formed using the materials exemplified as the materials for the corresponding components in the description of the wiring board 1 in Figure 1A. Furthermore, in Figures 2A to 3D, which are referenced below, the metal film layer and the plating film layer, which are components of each conductor layer, are not depicted, and each conductor layer is depicted as a single layer, similar to Figure 1A.

[0027] The manufacturing method of the wiring board of this embodiment includes forming a laminate and dividing the laminate into a plurality of wiring boards. Furthermore, forming the laminate includes forming a first build-up portion, which includes one or more first insulating layers, on the first surface of a base substrate. Here, "laminated body" means a state in which a plurality of wiring boards to be divided into individual pieces by dicing are connected. Next, Figures 2A to 2D will be used to describe the formation of the laminate.

[0028] As shown in Figure 2A, a base substrate 100 is formed. In forming the base substrate 100, first, a glass substrate 100P is prepared, which may include, for example, soda-lime glass, borosilicate glass, or alkali-free glass. Next, through holes 101a are formed in the glass substrate 100P. In forming the through holes 101a, for example, a modified area may be formed in the glass substrate 100P at the location where the through holes 101a are to be formed by irradiation with laser light, and the through holes 101a may be formed by removing the modified area with, for example, an etching solution containing an aqueous solution of hydrogen fluoride. As the laser light that forms the modified area, helium-neon lasers, argon ion lasers, excimer lasers, and various YAG lasers may be used.

[0029] Next, the interior of the through-hole 101a is completely filled with a conductor, and the conductor is formed to cover two surfaces of the glass substrate 100P that are perpendicular to the thickness direction. In forming the conductor, a metal film layer (not shown) is formed on the inner wall surface of the through-hole 101a and on the two surfaces of the glass substrate 100P, for example by electroless plating. Furthermore, a plating film layer (not shown) is formed on the metal film layer by electroplating, using the metal film layer as a power supply layer. A through-conductor 101 having the metal film layer and the plating film layer is formed, and the two surfaces of the glass substrate 100P are covered with a conductor having a two-layer structure of a metal film layer and a plating film layer. Next, the layers of conductor covering the two surfaces of the glass substrate 100P are removed, for example by CMP (chemical mechanical polishing). As a result, a base substrate 100 having a first surface 100f and a second surface 100s is formed, as shown in Figure 2A.

[0030] The base substrate 100 includes a plurality of wiring board forming regions BA corresponding to a plurality of connected wiring boards 1 to be manufactured.

[0031] Next, as shown in Figure 2B, a first insulating layer 11 is formed on the first surface 100f of the base substrate 100, and then a first conductor layer 12 is formed on top of the first insulating layer 11. Simultaneously with the formation of the first conductor layer 12, a first via conductor 13 is formed integrally with the first conductor layer 12. The first insulating layer 11 is laminated over a plurality of wiring board formation regions BA, and the first conductor layer 12 and the first via conductor 13 are formed inside each wiring board formation region BA, respectively. Furthermore, a second insulating layer 21 is formed on the second surface 100s of the base substrate 100, and then a second conductor layer 22 is formed on top of the second insulating layer 21. Simultaneously with the formation of the second conductor layer 22, a second via conductor 23 is formed integrally with the second conductor layer 22. The second insulating layer 21 is laminated over a plurality of wiring board formation regions BA, and the second conductor layer 22 and the second via conductor 23 are formed inside each wiring board formation region BA, respectively.

[0032] The first insulating layer 11 and the second insulating layer 21 can be formed by thermocompression bonding of a film-like insulating resin (e.g., epoxy resin) onto the surface (first surface 100f and second surface 100s) of the base substrate 100. A through-hole 13a is formed in the first insulating layer 11 at the position where the first via conductor 13 is to be formed, for example by irradiation with carbon dioxide laser light. The first conductor layer 12 and the first via conductor 13 are formed by forming a metal film layer (not shown) on the inner wall surface of the through-hole 13a and the upper surface of the first insulating layer 11 by electroless plating or sputtering, and forming a plating film (not shown) by electroplating using a plating resist with appropriate openings and the metal film layer as a power supply layer. A through-hole 23a is formed in the second insulating layer 21 at the position where the second via conductor 23 is to be formed, for example by irradiation with carbon dioxide laser light. The second conductor layer 22 and the second via conductor 23 are formed by forming a metal film layer (not shown) on the inner wall surface of the through hole 23a and the upper surface of the second insulating layer 21 by electroless plating or sputtering, and by forming a plating film (not shown) by electroplating using a plating resist with appropriate openings and the metal film layer as a power supply layer.

[0033] Next, as shown in Figure 2C, the above-described process of forming the first insulating layer 11, as well as the first via conductor 13 and the first conductor layer 12, on the first surface 100f side of the base substrate 100 is repeated a desired number of times to form a desired number of first insulating layers 11 and first conductor layers 12. The outermost first conductor layer 12 is formed to have a pattern including a conductor pad 12fp. The above-described process of forming the second insulating layer 21, as well as the second via conductor 23 and the second conductor layer 22, on the second surface 100s side of the base substrate 100 is repeated a desired number of times to form a desired number of second insulating layers 21 and second conductor layers 22. The outermost second conductor layer 22 is formed to have a pattern including a conductor pad 22sp.

[0034] Next, as shown in Figure 2D, a solder resist layer 10Rf is formed over multiple wiring board formation regions BA on the outermost first conductor layer 12 and first insulating layer 11 on the first surface 100f side of the base substrate 100. The solder resist layer 10Rf has an opening 10Rfa that exposes the conductor pad 12fp. This completes the formation of the first build-up section 10. A solder resist layer 20Rs is formed over multiple wiring board formation regions BA on the outermost second conductor layer 22 and second insulating layer 21 on the second surface 100s side of the base substrate 100. The solder resist layer 20Rs has an opening 20Rsa that exposes the conductor pad 22sp. This completes the formation of the second build-up section 20. The formation of a laminate 1P is completed in which multiple wiring boards 1, each having one surface 1F and the other surface 1S opposite to the first surface 1F as two main surfaces, are connected.

[0035] Next, with reference to Figures 3A to 3D, the process of dividing the formed laminate 1P into individual wiring boards 1 will be described. In the manufacturing method of the wiring board of this embodiment, dividing the laminate includes forming a groove in the first build-up portion in the thickness direction of the first build-up portion using a dicing blade, and inserting the dicing blade into the groove and cutting the laminate 1P from the bottom surface of the groove toward the second build-up portion. Preferably, forming the groove includes exposing the first insulating layer 11, which is laminated on the first surface 100f of the base substrate 100, at the bottom surface of the groove.

[0036] First, as shown in Figure 3A, the first build-up portion 10 is cut by a dicing blade DB along a virtual line BD that indicates the boundary between multiple wiring boards 1 in the laminate 1P. For example, the center of the thickness of the dicing blade DB is adjusted to coincide with the boundary BD. Alternatively, either of the two main surfaces DBs1 and DBs2 of the dicing blade DB may be adjusted to coincide with the boundary BD. After the adjustment, the first build-up portion 10 is cut by the dicing blade DB. As a result, a groove GB extending in the Z direction is formed in the first build-up portion 10, as shown in Figure 3B. As the dicing blade DB, for example, a dicing blade in which diamond abrasive grains are embedded in resin is used. The groove GB can be formed over the entire rectangular periphery of each wiring board 1 in a plan view. Note that in Figure 3B, the dicing blade DB is shown to be temporarily withdrawn from the groove GB after the groove GB is formed in order to make the shape of the groove GB easier to understand, but this is not limited to the diagram. In other words, after the groove GB is formed, the dicing blade DB may be left in the groove GB, and the next step (Figure 3C) may be carried out as is.

[0037] As shown in Figure 3B, the groove GB does not penetrate the first build-up portion 10, and at the bottom surface GBb of the groove GB, a portion of the first insulating layer 11 (insulating layer 110) laminated on the first surface 100f of the base substrate 100 remains as a thin layer. As a result, the insulating layer 110 is exposed at the bottom surface GBb. The thickness d between the bottom surface GBb of the groove GB and the first surface 100f of the base substrate 100 is 0.3 μm or more and 40 μm or less. Note that if the bottom surface GBb of the groove GB is not flat, the thickness d from the bottom surface GBb of the groove GB to the first surface 100f of the base substrate 100 can be the average value of values ​​measured at at least three locations in the width direction (left-right direction in Figure 3B) of the groove GB1.

[0038] Next, as shown in Figure 3C, the dicing blade DB cuts the laminate 1P along the groove GB from the bottom surface GBb of the groove GB to the other surface 1S. For example, the center of the thickness of the dicing blade DB is positioned to coincide with the boundary BD. Alternatively, either of the two main surfaces DBs1 and DBs2 of the dicing blade DB may be positioned to coincide with the boundary BD. After positioning, the dicing blade DB continuously cuts the insulating layer 110 exposed on the bottom surface GBb of the groove GB, the base substrate 100, and the multiple second insulating layers 21 and second conductor layers 22 that constitute the second build-up portion 20, as well as the solder resist layer 20Rs. This completely separates the multiple connected wiring boards 1, as shown in Figure 3D, and the manufacturing of the individual wiring boards 1 is completed.

[0039] As described above in the prior art, when a laminate in which a build-up portion is formed on a base substrate is continuously cut with a dicing blade from one surface to the other, defects such as cracks in the base substrate and delamination between the base substrate and the build-up portion may occur. Specifically, frictional heat may be generated due to friction between the dicing blade and the laminate during the cutting process from one surface of the laminate to the base substrate. Therefore, at the point when the dicing blade and the base substrate come into contact, thermal stress may be locally concentrated near the interface between the build-up portion and the base substrate near the dicing blade. Due to this localized concentration of thermal stress, cracks may occur in the base substrate or delamination may occur between the build-up portion and the base substrate when the base substrate and the dicing blade come into contact.

[0040] In the manufacturing method of the wiring board of this embodiment, the laminate 1P is not divided all at once with the dicing blade DB, but a groove GB is formed in the first build-up section 10 in advance using the dicing blade DB. A portion of the first insulating layer 11 (insulating layer 110) is exposed at the bottom surface GBb of the groove GB. As a result, when the laminate 1P is cut along the groove GB, the dicing blade DB first contacts the insulating layer 110, which remains as a thin layer, before contacting the base substrate 100. It is thought that a mechanical shock is applied to the insulating layer 110 by the contact, but the insulating layer 110, which is mainly made of resin, easily absorbs the shock, and therefore defects such as cracks are unlikely to occur. Subsequently, when the dicing blade DB contacts the base substrate 100, the dicing blade DB contacts the base substrate 100 continuously from the insulating layer 110, so it is thought that a large shock is unlikely to be applied to the base substrate 100. Therefore, it is thought that localized stress concentration due to contact with the dicing blade DB is unlikely to occur on the base substrate 100. In other words, a portion of the insulating layer 110 remaining on the first surface 100f of the base substrate 100 can act as a stress relaxation region that may occur when the base substrate 100 is cut. On the other hand, since the remaining portion of the insulating layer 110 is thin and relatively flexible, delamination from the base substrate 100 is unlikely to occur when cut by the dicing blade DB.

[0041] Furthermore, by pre-forming grooves GB in the first build-up section 10 using the dicing blade DB, the amount of heat generated by friction between the dicing blade DB and the laminate 1P is reduced. This is expected to suppress the occurrence of cracks in the base substrate 100 due to thermal stress and delamination between the first build-up section 10 and the base substrate 100.

[0042] In the examples shown in Figures 3A to 3D, the dicing blade DB used to form the groove GB in the first build-up section 10 and the dicing blade DB used to cut the laminate 1P along the groove GB are the same or can be considered the same. Specifically, the cutting width DBw is the same for the dicing blade DB used to form the groove GB in the first build-up section 10 and the dicing blade DB used to cut the laminate 1P along the groove GB. Furthermore, in the process of forming the groove GB shown in Figure 3A and the process of cutting the laminate 1P shown in Figure 3C, the position of the dicing blade DB is adjusted to coincide with the boundary BD. As a result, the cut surface (first side surface) GS of the first build-up section 10 exposed after cutting the laminate 1P, the base substrate 100, and the cut surface (second side surface) CS of the second build-up section 20 are formed to be substantially flush. This can reduce the likelihood of delamination between the base substrate 100 and the build-up section of the wiring board 1.

[0043] Furthermore, when a wiring board 1β is manufactured without the second build-up portion 20 shown in Figure 1C, the second side surface CS is the cut surface of the base substrate 100. Even in this case, the first surface GS and the second surface CS are formed to be substantially flush. This makes it less likely for the base substrate 100 and the first build-up portion 10 of the wiring board 1β to separate.

[0044] The step shown in Figure 3C, in which the laminate 1P is cut along the groove GB by the dicing blade DB, may be performed after a predetermined time has elapsed following the step shown in Figure 3B, in which the groove GB is formed by the dicing blade DB. That is, after the formation of the groove GB by the dicing blade DB is completed, the cutting of the laminate 1P by the dicing blade DB is suspended for a predetermined time or longer. The predetermined time is preferably 1 second or longer. This promotes the dissipation of frictional heat generated when forming the groove GB, thereby lowering the temperature and reducing the temperature reached by frictional heat when cutting the laminate 1P, and potentially suppressing cracks and delamination due to thermal stress.

[0045] During a predetermined period of time when cutting with the dicing blade is interrupted, the rotation of the dicing blade DB may be stopped. This can suppress the generation of frictional heat between the dicing blade DB and the laminate 1P, thereby suppressing cracks and delamination due to thermal stress. Alternatively, during a predetermined period of time when cutting with the dicing blade is interrupted, the dicing blade DB may be temporarily withdrawn from the groove GB and then reinserted into the groove GB. This promotes heat dissipation of the dicing blade DB itself, lowering its temperature and reducing the temperature reached by frictional heat when it is reinserted into the groove GB and cuts the laminate 1P, thereby suppressing cracks and delamination due to thermal stress.

[0046] In the step of forming a groove GB with the dicing blade DB and the step of cutting the laminate 1P along the groove GB with the dicing blade DB, the rotation speed of the dicing blade DB may be changed. Preferably, the rotation speed of the dicing blade DB in the step of cutting the laminate 1P along the groove GB may be lower than in the step of forming the groove GB. This may reduce the impact when the dicing blade DB contacts the base substrate 100, suppress the generation of frictional heat when cutting the base substrate 100, and suppress the occurrence of cracks in the base substrate 100 and delamination between the base substrate 100 and the build-up portion.

[0047] In the described method for manufacturing the wiring board, the lamination of the laminate 1P is performed without forming a groove in the second build-up portion 20. Therefore, in the process of cutting the base substrate 100 and the second build-up portion 20 using the dicing blade DB, localized stress concentration in the second build-up portion 20 is less likely to occur, and distortion of the second build-up portion 20 is less likely to occur. A faithful cut along the boundary BD is achieved, and the wiring board 1 can be formed to the desired dimensions.

[0048] The manufacturing method of the wiring board in the embodiment is not limited to the method described with reference to each drawing, and the conditions and sequence may be changed as appropriate. Depending on the structure of the wiring board to be manufactured, some steps may be omitted or other steps may be added in the manufacturing method of the embodiment. Furthermore, the wiring board manufactured by the manufacturing method of the embodiment is not limited to having the structure shown in Figures 2A to 3D. For example, the wiring board may not have the second build-up section 20 formed, as shown in the wiring board 1β in Figure 1C, in which case the steps for forming the through-hole 101a and through-conductor 101 shown in Figure 2A, and the steps for forming the second build-up section 20 shown in Figures 2B to 2D may be omitted. [Explanation of symbols]

[0049] 1, 1α, 1β Wiring board 1P Laminate 10. First Build-up Department 20. Second Build-up Department 11. Insulating layer (first insulating layer) 21. Insulating layer (second insulating layer) 12 Conductor layer (First conductor layer) 22 Conductor layer (second conductor layer) 13 Via conductor (first via conductor) 23 Via conductor (2nd via conductor) 100 base board 101 Through-conductor 12fp, 22sp conductor pads BA wiring board formation area BD boundary DB Dicing Blade GB Groove Side view of the DS wiring board GS First side view (side view of groove) CS second aspect

Claims

1. Forming a laminate, A method for manufacturing a wiring board, comprising dividing the laminate into a plurality of wiring boards, Forming the aforementioned laminate is The method includes forming a first build-up portion on the first surface of a base substrate having a first surface and a second surface opposite to the first surface, such that it includes one or more first insulating layers. Dividing the aforementioned laminate is The dicing blade forms grooves in the first build-up portion in the thickness direction of the first build-up portion, The process includes, after the formation of the groove, cutting the laminate along the groove with the dicing blade.

2. A method for manufacturing a wiring board according to claim 1, Forming the aforementioned groove portion This includes the fact that a portion of the first insulating layer included in the first build-up portion is exposed on the bottom surface of the groove.

3. A method for manufacturing a wiring board according to claim 1, The thickness from the bottom surface of the groove to the first surface of the base substrate is 0.3 μm or more and 40 μm or less.

4. A method for manufacturing a wiring board according to claim 1, The base substrate includes a glass substrate.

5. A method for manufacturing a wiring board according to claim 1, Cutting the aforementioned laminate is This includes forming the cut surface of the first build-up portion and the cut surface of the base substrate to be substantially flush.

6. A method for manufacturing a wiring board according to claim 1, Forming the laminate includes forming a second build-up portion on the second surface of the base substrate, which includes one or more second insulating layers.

7. A method for manufacturing a wiring board according to claim 6, Cutting the aforementioned laminate is This includes forming the cut surface of the first build-up portion and the cut surfaces of the base substrate and the second build-up portion to be substantially flush.

8. A method for manufacturing a wiring board according to claim 1, Cutting the aforementioned laminate is Since the groove is formed, the procedure is performed after a predetermined amount of time has elapsed.

9. A method for manufacturing a wiring board according to claim 8, The predetermined time is 1 second or more.

10. A method for manufacturing a wiring board according to claim 1, Between forming the groove and cutting the laminate, The rotation of the dicing blade is interrupted.

11. A method for manufacturing a wiring board according to claim 1, Between forming the groove and cutting the laminate, The rotation of the dicing blade continues.

12. A method for manufacturing a wiring board according to claim 11, Between forming the groove and cutting the laminate, The rotation speed of the dicing blade is changed.

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