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 and dividing the laminate into a plurality of wiring boards, forming the laminate 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, including a plurality of first insulating layers, dividing the laminate includes forming a groove GB1 through the first build-up portion 10 in the first build-up portion 10 and cutting the base substrate 100 with a dicing blade through the groove GB1 toward the second surface of the base substrate 100, forming the groove GB1 includes forming a notch GB1a on the first surface 100f side of the base substrate 100 that does not penetrate the base substrate 100.

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, the glass substrate and the laminate laminated on both surfaces of the glass substrate are cut together by a dicing blade. There is a possibility that defects such as cracks in the glass substrate and peeling of the resin layer from the glass substrate may occur.

Means for Solving the Problems

[0005] The present invention relates to a method for manufacturing a wiring board, comprising forming a laminate and dividing the laminate into a plurality of wiring boards. Forming the laminate comprises 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 a plurality of first insulating layers, dividing the laminate comprises forming a groove portion through the first build-up portion in the first build-up portion and cutting the base substrate with a dicing blade through the groove portion toward the second surface of the base substrate, forming the groove portion comprises forming a notch portion on the first surface side of the base substrate that does not penetrate the base substrate.

[0006] According to embodiments of the present invention, the laminate can be divided into a plurality of wiring boards with good yield. [Brief explanation of the drawing]

[0007] [Figure 1] A cross-sectional view showing an example of a wiring board manufactured by the wiring board manufacturing method of an embodiment of the present invention. [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. [Figure 4] A cross-sectional view showing another example of a wiring board manufactured by the wiring board manufacturing method of an embodiment of the present invention. [Figure 5A] A cross-sectional view showing an example of a manufacturing method for a wiring board according to another embodiment. [Figure 5B] A cross-sectional view showing an example of a manufacturing method for a wiring board according to another embodiment. [Figure 5C] A cross-sectional view showing an example of a manufacturing method for a wiring board according to another 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 1 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 conductor layers and insulating layers contained in the wiring board, may differ from the laminated structure of wiring board 1 in Figure 1, and the number of conductor layers and insulating layers contained in wiring board 1. Also, 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: a first surface 1F and a second surface 1S opposite to the first surface 1F.

[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] Furthermore, in describing 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 board 100 is referred to as "bottom," "inside," or "lower side" or "inside," and the side further from the base board 100 is referred to as "top," "outside," or "upper side" or "outside." The surface of each component of the wiring board 1 that faces the base board 100 is also referred to as the "bottom surface," and the surface that faces away from the base board 100 is also referred to as the "top surface."

[0012] For example, a through conductor 101 is formed on the base substrate 100, penetrating the base substrate 100 in the thickness direction. In the example in Figure 1, the base substrate 100 is a core substrate with build-up sections on both sides. In the following description of the wiring board 1 in Figure 1, the base substrate 100 will also be referred to as the core substrate 100. The first insulating layer 11 constituting the first build-up section 10 has a first via conductor 13 formed thereon, penetrating the first insulating layer 11 in the thickness direction and connecting conductors facing each other across the first insulating layer 11, i.e., two first conductor layers 12, or the first conductor layer 12 and the through conductor 101. The second insulating layer 21 constituting the second build-up section 20 has a second via conductor 23 formed thereon, penetrating the second insulating layer 21 in the thickness direction and connecting conductors facing each other across the second insulating layer 21, i.e., two second conductor layers 22, or the second conductor layer 22 and the through conductor 101.

[0013] The through-conductor 101 is formed by filling a through-hole 101a (see FIG. 2A) formed in the core substrate 100 with a conductor. In the illustrated example, the end surface of the through-conductor 101 in the extending direction is formed substantially flush with the surface of the core substrate 100, and constitutes the first surface 100f and the second surface 100s of the core substrate 100. The first via-conductor 13 is formed by filling a through-hole 13a (see FIG. 2B) 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 contacts the surface of the first insulating layer 11 opposite to the core substrate 100 through which the first via-conductor 13 passes. The second via-conductor 23 is formed by filling a through-hole 23a (see FIG. 2B) 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 contacts the surface of the second insulating layer 21 opposite to the core substrate 100 through which the second via-conductor 23 passes.

[0014] The base substrate 100 included in the wiring substrate manufactured by the manufacturing method of the embodiment is a glass substrate. The core substrate 100 of the illustrated wiring substrate 1 is formed using a glass substrate. As the glass material used for the glass substrate constituting the core substrate 100, for example, soda lime glass, borosilicate glass, or non-alkali glass, etc. can be used. These glasses can contain elements such as magnesium, calcium, manganese, aluminum, lead, iron, chromium, potassium, sulfur, antimony, boron, etc. as additives. Further, the base substrate 100 included in the wiring substrate may be a substrate containing a material other than glass such as a silicon substrate, a ceramic substrate, a resin substrate, etc.

[0015] The first insulating layer 11 and the second insulating layer 21 are formed using an arbitrary insulating resin. Examples of the insulating resin 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), ethylene fluoride (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 and aramid fibers.

[0016] Examples of the conductors constituting 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 copper and nickel, and preferably copper is used. In the example shown in FIG. 1, 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 they may be configured with 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] The first conductor layer 12 and the second conductor layer 22 constituting the wiring board 1 are each patterned to have a predetermined conductor pattern. The first conductor layer 12 constituting the first surface 1F of the wiring board 1 is formed in a pattern having a plurality of conductor pads 12fp. The second conductor layer 22 constituting the second surface 1S of the wiring board 1 is formed in a pattern having a plurality of conductor pads 22sp.

[0018] 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 a conductor pad 12fp is exposed through the opening 10Rfa. That is, the first surface 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 a conductor pad 22sp is exposed through the opening 20Rsa. That is, the second surface 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.

[0019] The first surface 1F of the illustrated example wiring board 1 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 second surface 1S of the wiring board 1 may be a connection surface to which the wiring board 1 is connected when the wiring board 1 is mounted on an external board, for example, which is 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.

[0020] The single wiring board 1 in the illustrated example is formed by dividing a laminate containing multiple wiring boards 1 into individual wiring boards 1, as will be described in detail later. The side surface extending in the thickness direction of the wiring board 1 is the surface exposed by dividing the laminate into individual wiring boards 1. In plan view, each wiring board 1 has a rectangular shape, and in the above-described laminate, multiple wiring boards 1 are connected in a grid pattern. Here, "plan view" means viewing the object from a line of sight parallel to the thickness direction of the wiring board 1. As will be described in detail later (see Figures 3A to 3D), in the process of dividing a laminate in which multiple wiring boards 1 are connected into individual wiring boards 1, a groove GB1 is formed in the thickness direction of the first build-up portion, and then the laminate is cut through the groove GB1. The formation of the groove GB1 can be carried out so as to penetrate the first build-up portion, and a notch GB1a is formed on the first surface 100f side of the core substrate 100 that does not penetrate the core substrate 100. By pre-forming the notch GB1a in the core substrate 100, the occurrence of cracks in the core substrate is suppressed during the individual piece formation process for the wiring substrate 1, resulting in a high yield of the wiring substrate 1.

[0021] In the illustrated wiring board 1, the side surface CS1 of the first build-up portion 10 extending in the thickness direction of the wiring board 1 is formed to have a taper such that the end of side surface CS1 on the first surface 1F side of the wiring board 1 is located in the direction of the interior of the wiring board 1 relative to the end of side surface CS1 on the first surface 100f side of the core substrate 100. That is, the end of side surface CS1 on the first surface 1F side of the wiring board 1 is located in the direction of the interior of the wiring board 1 relative to the core substrate 100 and the side surface CS2 of the second build-up portion 20. External forces are less likely to be applied to the first build-up portion 10 in the wiring board 1 after it has been separated into individual pieces. Peeling of the first build-up portion 10 from the core substrate 100 in the wiring board 1 may be less likely to occur. The side surface CS1 of the first build-up portion 10 may include the groove side surface GS1 (see Figure 3A) of the groove GB1. The groove side surface GS1 is composed of the side surfaces of each first insulating layer 11, and the side surfaces of each first insulating layer 11 are formed to be substantially flush with each other.

[0022] The side surfaces CS2 of the core substrate 100 and the second build-up section 20 are the cut surfaces exposed when a laminate of multiple interconnected wiring boards 1 is cut and separated into individual wiring boards 1. The side surfaces CS2 of the core substrate 100 and the second build-up section 20 are formed substantially parallel to the thickness direction of the wiring board. The side surfaces of the second build-up section 20 that constitute the side surfaces CS2 are composed of the side surfaces of individual second insulating layers 21, and the side surfaces of each second insulating layer 21 are formed substantially flush with each other. Although not shown in the figures, the side surfaces of the second build-up section 20 may also be tapered in the same way as the side surfaces CS1 of the first build-up section 10, that is, the end of the side surface of the second build-up section 20 on the second surface 1S side of the wiring board 1 is positioned in the direction of the interior of the wiring board 1 relative to the end of the core substrate 100 on the second surface 100s side. In this case, a groove similar to the groove GB1 formed in the first build-up portion 10 is formed in the second build-up portion 20 at a position that overlaps with the groove GB1 formed in the first build-up portion 10 in a plan view, and then the laminate is cut. This suppresses peeling of the second build-up portion 20, and further improves the yield of the wiring board 1 in the individual pieceization process.

[0023] 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 1 is manufactured as an example. 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 1. Furthermore, in Figures 2A to 5C, which will be referenced below, the metal film layer and 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 1.

[0024] The manufacturing method of the wiring board of this embodiment includes forming a laminate including a base substrate and first and second build-up portions formed on both sides of the base substrate, and dividing the laminate into a plurality of wiring boards. Here, "laminated body" refers to a state in which a plurality of wiring boards to be divided into individual pieces by dicing are connected. First, Figures 2A to 2D will be shown to explain the formation of the laminate.

[0025] As shown in Figure 2A, a core substrate 100 is formed as a base substrate 100. In forming the core substrate 100, first, a glass substrate 100P is prepared, which may include, for example, soda-lime glass, borosilicate glass, or alkali-free glass. 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.

[0026] Next, the interior of the formed through-hole 101a is completely filled with a conductor, and the conductor is formed to completely 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, and then 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 two-layer structure of conductors consisting of the metal film layer and the plating film layer. Subsequently, the conductor layer covering both sides of the glass substrate 100P is removed, for example by CMP (chemical mechanical polishing). As shown in Figure 2A, a core substrate 100 having a first surface 100f and a second surface 100s is formed.

[0027] The core substrate 100 that is formed includes a plurality of wiring board forming regions BA corresponding to a plurality of connected wiring boards 1 to be manufactured.

[0028] Next, as shown in Figure 2B, a first insulating layer 11 is laminated to cover the first surface 100f of the core 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 in the plurality of wiring board formation regions BA. A second insulating layer 21 is formed to cover the second surface 100s of the core 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 in the plurality of wiring board formation regions BA.

[0029] 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 of the core substrate 100, i.e., the first surface 100f and the second surface 100s. 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 on the inner surface of the through-hole 13a and the upper surface of the first insulating layer 11 by electroless plating or sputtering, and by electroplating a plating film (not shown) using a plating resist with appropriate openings and using 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 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 having appropriate openings and using the metal film layer as a power supply layer.

[0030] Next, as shown in Figure 2C, on the upper side of the first surface 100f of the core substrate 100, the same process as described above for forming the first insulating layer 11 and the integral formation of the first via conductor 13 and the first conductor layer 12 is repeated a desired number of times to form a desired number of first insulating layers 11 and first conductor layers 12. Also, on the upper side of the second surface 100s, the same process as described above for forming the second insulating layer 21 and the integral formation of the second via conductor 23 and the second conductor layer 22 is repeated a desired number of times to form a desired number of second insulating layers 21 and second conductor layers 22. The outermost first conductor layer 12 is formed in a pattern including a conductor pad 12fp. The outermost second conductor layer 22 is formed in a pattern including a conductor pad 22sp.

[0031] 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 core substrate 100, with openings 10Rfa that expose the conductor pads 12fp. The formation of the first build-up section 10 is completed. On the outermost second conductor layer 22 and second insulating layer 21 on the second surface 100s side of the core substrate 100, a solder resist layer 20Rs is formed over multiple wiring board formation regions BA, with openings 20Rsa that expose the conductor pads 22sp. The formation of the second build-up section 20 is completed. The formation of a laminate 1P in which multiple wiring boards 1, each having a first surface 1F and a second surface 1S opposite to the first surface 1F, is completed.

[0032] 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 that penetrates the first build-up portion and cutting the base substrate toward its second surface through the groove. Figures 3A to 3D show an example in which dividing the laminate also includes cutting the second build-up portion together with the core substrate.

[0033] First, as shown in Figure 3A, grooves GB1 are formed from the first surface 1F of the wiring board 1 along the boundary BD between the multiple wiring boards 1 in the laminate 1P, forming the first build-up portion 10 in the thickness direction. The grooves GB1 can be formed by cutting the first build-up portion 10 along the boundary BD using any dicing blade (first dicing blade, not shown), such as a diamond blade in which diamond abrasive grains are embedded in resin, which can be used for general dicing.

[0034] For example, the groove GB1 may be formed in a tapered shape, with its opening width decreasing from the first surface 1F of the wiring board 1 towards the first surface 100f of the core board 100. Such a groove GB1 can be formed, for example, by using a dicing blade having a tapered shape that becomes sharp towards the tip of the blade as the first dicing blade. The groove GB1 may also be formed by cutting with another cutting member (cutter) such as a scriber, or by irradiating laser light, such as a carbon dioxide laser, from the outside of the first build-up portion 10 toward the laminate 1P. The groove GB1 may be formed over the entire rectangular periphery of each wiring board 1 in a plan view.

[0035] In the illustrated example, the groove GB1 is formed as a groove that penetrates the first build-up portion 10 in the thickness direction. The groove GB1 includes a notch GB1a on the first surface 100f side of the core substrate 100 that does not penetrate the core substrate 100. The first surface 100f of the core substrate 100, other than the area in which the notch GB1a is formed, is covered by the first insulating layer 11 that is closest to the core substrate 100 among the plurality of first insulating layers 11 that constitute the first build-up portion 10. For example, the groove GB1 is formed in a tapered shape where the opening width GBw1 of the groove GB1 on the first surface 1F side of the wiring board 1 is larger than the opening width GBw2 of the groove GB1 on the first surface 100f side of the core substrate 100. Therefore, the notch GB1a is also formed in a tapered shape that decreases from the first surface 100f to the second surface 100s of the core substrate 100. The depth GBt of the notch GB1a from the first surface 100f of the core substrate 100 is, for example, 10% or more and 30% or less of the thickness of the core substrate 100. By forming the notch GB1a in the core substrate 100 before cutting, it is thought that the stress that may occur in the core substrate 100 when the core substrate 100 is cut as described later is relieved, and damage to the core substrate 100 is reduced.

[0036] Next, as shown in Figure 3B, the core substrate 100 and the second build-up portion 20 are cut toward the second build-up portion 20 through the notch GB1a of the groove GB1. Note that Figure 3B shows an enlarged view of portion III, which is the area enclosed by the dashed line in Figure 3A, illustrating the cutting process of this embodiment. In this embodiment, the core substrate 100 and the second build-up portion 20 are cut by, for example, a second dicing blade DB2. Individualization occurs when the second dicing blade DB2 reaches the surface of the solder resist layer 20Rs. Note that the cutting of the core substrate 100 and the second build-up portion 20 can be performed by a cutting member capable of cutting the core substrate 100 and the second build-up portion 20 in the thickness direction. Examples of cutting members include a dicing blade or other cutting members (cutters) such as a scriber, but a dicing blade is sometimes preferred. Cutting can be performed without damaging the surface of the wiring board 1. In each of the multiple fragmentation processes, the cross-section of the core substrate 100 formed can be obtained with a stable and consistent shape.

[0037] In the manufacturing method of the wiring board of this embodiment, a groove GB1 is formed in the first build-up section 10 before the core substrate 100 is cut by the dicing blade. When the groove GB1 is formed, it is considered that it is easier to insert the second dicing blade DB2 substantially parallel to the thickness direction compared to when the first surface 1F of the laminate 1P (see Figure 3A) is flat (when the groove GB1 is not formed). It is considered that the cutting of the core substrate 100 can be performed accurately and easily along the boundary BD.

[0038] In the manufacturing method of the wiring board of this embodiment, a different dicing blade from the first dicing blade used to form the groove GB1 may be used as the second dicing blade DB2 used to cut the core substrate 100 and the second build-up portion 20. As shown in Figure 3B, the second dicing blade DB2 has a blade width DBw2 that is substantially equal along the entire length of the blade, as the blade width in the horizontal direction (left-right direction in Figure 1) of the wiring board 1. Therefore, the cutting of the core substrate 100 and the second build-up portion 20 is performed such that the sides of the core substrate 100 and the second build-up portion 20 after cutting are substantially parallel to the thickness direction of the wiring board.

[0039] The blade width DBw2 of the second dicing blade DB2 is smaller than the opening width GBw1 of the groove GB1 on the first surface 1F side of the wiring board 1. Because the second dicing blade DB2 fits within the groove GB1, it is considered that misalignment of the second dicing blade DB2 in the width direction (left-right direction in Figure 3B) of the groove GB1 is unlikely to occur. It is considered that cutting along the boundary BD can be easily performed. In addition, since the cutting of the core board 100 by the dicing blade is performed with a narrower blade, it is considered that damage to the core board 100 during cutting is reduced.

[0040] The blade width DBw2 of the second dicing blade DB2 is approximately equal to or greater than the opening width GBw2 (see Figure 3A) of the groove GB1 on the first surface 100f of the core substrate 100. In the illustrated method for manufacturing a wiring board, an example is shown in which the core substrate 100 and a plurality of second insulating layers 21 are continuously cut using a dicing blade having a blade width DBw2 that is approximately equal to the opening width GBw2 (see Figure 3A). The laminate 1P (see Figure 3A) is separated into individual pieces, and a plurality of wiring boards 1 are cut out as shown in Figure 3C.

[0041] As shown in Figure 3D, the cut wiring board 1 has sides composed of a side surface CS1 of the first build-up section 10, which is made up of the groove side surface GS1 (see Figure 3B) of the groove GB1, and sides CS2 of the core board 100 and the second build-up section 20, which are cut surfaces formed by cutting for individualization. The side surface of the core board 100 after cutting and the first surface 100f of the core board 100 near the side surface are covered by the first insulating layer 11 that is located closest to the core board 100 among the plurality of first insulating layers 11 that constitute the first build-up section 10.

[0042] Side surface CS1 is composed of the side surfaces of individual first insulating layers 11 within the first build-up section 10, and the side surfaces of individual first insulating layers 11 are formed substantially flush with each other. It is believed that the occurrence of defects such as peeling of the first insulating layers 11 within the first build-up section 10 can be suppressed. Side surface CS1 is formed in a tapered shape such that the end of side surface CS1 on the first surface 1F side of the wiring board 1 is located in the direction of the interior of the wiring board 1 relative to the end of side surface CS1 on the first surface 100f side of the core board 100. Side surfaces CS2 of the core board 100 and the second build-up section 20 are formed substantially parallel to the thickness direction of the wiring board 1, i.e., without tapering, and substantially flush with each other. Since the opening width GBw2 of the groove GB1 on the first surface 100f of the core substrate 100 (see Figure 3A) and the blade width DBw2 of the second dicing blade DB2 for cutting the core substrate 100 and the second build-up portion 20 (see Figure 3B) are approximately equal, the side surface CS1 does not include the cut surface made by the second dicing blade DB2, and the side surface CS2 does not include the groove side surface GS1 of the groove GB1 (see Figure 3B).

[0043] Although not shown, when a second dicing blade DB2 having a blade width DBw2 (see Figure 3B) larger than the opening width GBw2 (see Figure 3A) of the groove GB1 on the first surface 100f of the core substrate 100 is used on the core substrate 100 and the second build-up section 20, the side surface CS1 is composed of the groove side surface GS1 (see Figure 3B) of the groove GB1 and the cut surface made by the second dicing blade DB2. In this case as well, the side surface CS2 does not include the groove side surface GS1 of the groove GB1. That is, in the manufacturing method of the wiring board of this embodiment, the side surface CS2 is the cut surface made by the second dicing blade DB2. No protrusions or steps are formed on the side surface of the core substrate 100, which are the connection points between the groove side surface GS1 and the cut surface. A wiring board of good quality can be provided that is easy to handle and less prone to defects such as chipping on the core substrate 100.

[0044] In the above-described method for manufacturing the wiring board, the lamination 1P is divided without forming grooves or other structures in the second build-up section 20. When cutting the core substrate 100 and the second build-up section 20 using a dicing blade, localized stress concentration in the second build-up section 20 is less likely to occur. This is thought to suppress the occurrence of unintended cracks and other damage. Furthermore, misalignment between the cut surface of the first build-up section 10 and the cut surface of the second build-up section 20 is less likely to occur. This is thought to result in the wiring board 1 being cut to more accurate dimensions.

[0045] As described above, the wiring board 1 shown in Figure 1 is merely one example of a wiring board manufactured by the manufacturing method of the embodiment. In the wiring board 1 shown in Figure 1, a first build-up portion 10 and a second build-up portion 20 are formed on the first surface 100f and the second surface 100s of the core substrate 100, respectively, but the wiring board manufactured by the manufacturing method of the embodiment is not necessarily limited to this configuration. The wiring board manufactured by the manufacturing method of the embodiment may be, for example, a wiring board 1b shown in Figure 4, in which the second build-up portion is not formed on the second surface 100bs of the glass substrate 100b that functions as a base substrate.

[0046] The wiring board 1b can be manufactured in the same way as the wiring board 1, for example, by the process shown in Figures 5A to 5C. First, a laminate 1Pb is formed using the same process as shown in Figures 2B to 2D. That is, a first build-up portion 10b, which includes alternately stacked insulating layers 11b and conductive layers 12b, and via conductors 13b connecting the conductive layers 12b with the insulating layer 11b in between, is formed on the first surface 100bf of the glass substrate 100b. Next, using the same process as shown in Figure 3A, as shown in Figure 5A, grooves GB1b that penetrate the first build-up portion 10b in the thickness direction are formed from the first surface 1Fb of the wiring board 1b, for example, by a dicing blade or laser, along the boundary BD between the multiple wiring boards 1b. The grooves GB1b penetrate the first build-up portion 10b and are formed in a tapered shape that becomes smaller toward, for example, the first surface 100bf of the glass substrate 100b. The groove GB1b is formed in such a way that a notch GB1c is formed on the first surface 100bf side of the glass substrate 100b that does not penetrate the glass substrate 100b.

[0047] Next, using a process similar to that shown in Figure 3B, the glass substrate 100b is cut by the second dicing blade DB2 through the groove GB1b toward the second surface 100bs of the glass substrate 100b, as shown in Figure 5B. Note that, similar to Figure 3B, Figure 5B shows a magnified view of section V, which is the area enclosed by the dashed line in Figure 5A of the laminate 1Pb, illustrating the cutting process of this embodiment. The second dicing blade DB2, having a blade width DBw2 that is approximately equal to or greater than the opening width GBwb2 (see Figure 5A) of the groove GB1b on the first surface 100bf of the glass substrate 100b, and smaller than the opening width GBwb1 (see Figure 5A) on the first surface 1F side of the groove GB1b, is used to cut the glass substrate 100b. The laminate 1Pb is separated into individual pieces, and a plurality of wiring boards 1b are cut out, as shown in Figure 5C.

[0048] The side surface CS1b (see Figure 4) of the first build-up portion 10b of the wiring board 1b is formed in a tapered shape such that the end of side surface CS1b on the first surface 1Fb side of the wiring board 1 is located in the direction of the interior of the wiring board 1b relative to the end of side surface CS1b on the first surface 100bf side of the glass substrate 100b. Side surface CS2b is the cut surface of the glass substrate 100b by the second dicing blade DB2 (see Figure 5B).

[0049] The manufacturing method of the wiring board in the embodiment is not limited to the method described with reference to each drawing, and its conditions and sequence may be changed as appropriate. Depending on the structure of the wiring board being manufactured, some steps may be omitted or other steps may be added to the manufacturing method of the wiring board. Furthermore, the wiring board manufactured by the manufacturing method of the embodiment is not limited to having the structure shown in Figures 1 and 4. [Explanation of Symbols]

[0050] 1, 1b Wiring board 10, 10b First Build-up Section 11, 11b Insulating layer (first insulating layer) 110, 110b Insulating layer (first insulating layer) 12, 12b Conductor layer (first conductor layer) 13, 13b Via conductor (first via conductor) 20. Second Build-up Department 21. Insulating layer (second insulating layer) 22 Conductor layer (second conductor layer) 23 Via conductor (2nd via conductor) 100 base board 101 Through-conductor 100P, 100b glass substrate 12fp conductor pad 22sp Conductor Pad BA wiring board formation area BD boundary DB2 The Second Dicing Blade GB1 groove GB1a Notch GS1 groove side CS1 Side view of the first build-up section Side view of CS2 core board and 2 build-up section

Claims

1. Forming a laminate, A method for manufacturing a wiring board, comprising dividing the laminate into a plurality of wiring boards, Forming the laminate 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 a plurality of first insulating layers. Dividing the laminate includes forming a groove in the first build-up portion that penetrates the first build-up portion, and cutting the base substrate with a dicing blade through the groove toward the second surface of the base substrate. Forming the groove portion includes forming a notch on the first surface side of the base substrate that does not penetrate the base substrate.

2. A method for manufacturing a wiring board according to claim 1, wherein the base board is a glass board, the groove is formed by a first dicing blade, and the base board is cut by a second dicing blade different from the first dicing blade.

3. A method for manufacturing a wiring board according to claim 2, wherein cutting the base board includes cutting such that the side surface of the base board after cutting is substantially parallel to the thickness direction of the wiring board.

4. A method for manufacturing a wiring board according to claim 2, wherein forming a groove that penetrates the first build-up portion includes forming the groove in a tapered shape that becomes smaller toward the first surface of the base board.

5. A method for manufacturing a wiring board according to claim 2, wherein the blade width of the second dicing blade is substantially equal to or greater than the opening width of the first surface of the groove.

6. A method for manufacturing a wiring board according to claim 5, wherein the side surface of the first build-up portion after cutting includes the groove side surface of the groove portion.

7. A method for manufacturing a wiring board according to claim 2, wherein the first surface of the base substrate other than the notched portion after groove formation is covered with the insulating layer among the plurality of first insulating layers that is located closest to the base substrate.

8. A method for manufacturing a wiring board according to claim 7, wherein the side surface of the base board after cutting and the first surface of the base board near the side surface are covered by the insulating layer among the plurality of first insulating layers that is located closest to the base board.

9. A method for manufacturing a wiring board according to claim 2, wherein the first dicing blade has a tapered shape that becomes sharp towards the tip of the blade, and the second dicing blade has a blade width that is substantially equal along the entire length of the blade.

10. A method for manufacturing a wiring board according to claim 2, wherein forming the notch includes forming the notch in a tapered shape that becomes smaller toward the second surface of the base board.

11. A method for manufacturing a wiring board according to claim 2, wherein forming the laminate includes forming a second build-up portion on the second surface of the base substrate so as to include a plurality of second insulating layers, and dividing the laminate includes cutting the second build-up portion together with the base substrate using the second dicing blade.

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