JP2005340416A - Method for manufacturing board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a printed circuit board by which generation of dust at the time of processing the outer shape of the printed circuit board can be suppressed. <P>SOLUTION: Inner layer copper foil 2 having an inner layer circuit pattern is formed on a core material 1 obtained by impregnating resin in glass cloth, a slit 8 is formed on a boundary area between a product area 5 and a peripheral area 6, an insulating layer 3 is formed around the inner layer copper foil by molding press, the slit 8 is filled with the insulating layer, and after forming outer layer copper foil 4 having an outer layer circuit pattern on the insulating layer 3, the product area 5 and the peripheral area 6 are divided from the boundary area so that the insulating layer 3 filled in the slit is left in the product area 5 and the peripheral area 6. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a substrate. Specifically, fill the slit formed in the boundary area between the product area and the peripheral area with an insulating layer, and divide the product area so that the insulating layer filled in the slit remains on the outer periphery of the product area. This relates to a method for manufacturing a substrate.

  In recent years, mobile phones and mobile computers have been miniaturized, and the wiring density of printed wiring boards used in these devices has increased. Here, in order to increase the wiring density of the printed wiring board, it is necessary to narrow the wiring pitch, via hole pitch, and via diameter, but there are physical limitations, and further downsizing of mounting parts has reached the limit. ing. Therefore, for example, a substrate in which a thin film layer is formed on a printed wiring board having a flat surface using a wafer process and a passive element such as a resistor, a capacitor, or an inductor is built in the thin film layer is being developed ( For example, see Patent Document 1.)

  However, in the wafer process, the dust in the clean room greatly reduces the elements and wiring yield of the thin film layer, so it is necessary to suppress the generation of dust from materials including people, equipment, and substrates that are dust sources.

  Hereinafter, a conventional general printed wiring board manufacturing method will be described with reference to an example of a manufacturing method of a four-layer buildup board.

In the conventional method of manufacturing a printed wiring board, first, as shown in FIG. 4A, after forming an inner layer copper foil 102 on a core material 101 in which a glass cloth is impregnated with a resin, in FIG. As shown, an inner layer circuit is formed in a predetermined range of the inner layer copper foil by a general-purpose etching technique.
The inner layer circuit may be formed by any method such as a subtractive method, a semi-additive method, or a full additive method.

  Next, as shown in FIG. 4 (c), molding of prepreg (resin sheet in which glass cloth is impregnated with resin) and copper foil or RCC (Resin Coated Copper) is formed on the inner layer copper foil. The insulating layer 103 and the outer layer copper foil 104 are formed on the inner layer copper foil by pressing.

Subsequently, as shown in FIG. 5D, an outer layer circuit is formed on the outer layer copper foil in a predetermined range of the outer layer copper foil by a general-purpose etching technique.
Note that the outer layer circuit may be formed by any method such as a subtractive method, a semi-additive method, or a full additive method.

  Thereafter, as shown in FIG. 5 (e), by performing outline processing from the boundary region between the product region 105 and the peripheral region 106 which is the outer region of the product region, printed wiring as shown in FIG. 5 (f) is obtained. A substrate can be obtained.

  Note that external processing of the printed wiring board is mainly performed by press die processing, NC router processing, laser beam processing, and the like. Here, the press mold processing is performed by punching along the shear pattern formed on the mold by pressing the printed wiring board between a pair of upper and lower molds attached to the press machine. NC router processing is a method that enables drilling and slit processing, and NC router processing rotates a router bit attached to the NC router machine at a high speed, and the printed wiring board is formed into a predetermined shape by NC control. The laser beam processing is a method of processing a predetermined shape by irradiating a printed wiring board with a high-power laser under NC control.

JP 2002-368428 A

  By the way, since glass cloth or glass nonwoven fabric is used for most general printed circuit boards, burrs and scuffing of glass cloth and glass nonwoven fabric are generated due to shear stress or friction force when the above-mentioned outline processing is performed. Resulting in. Note that dust from the printed wiring board is mainly generated from the outer shape processing surface on the outer periphery of the printed wiring board.

  The burrs and markings generated in this way are formed by forming a thin film layer on a printed wiring board that has been subjected to external processing using a wafer process as described in Patent Document 1, for example, and passives such as resistors and inductors are formed there. When manufacturing a substrate with a built-in element, it drops off from the side surface of the substrate and becomes dust, which causes a significant decrease in thin film formation yield. Furthermore, since the processed surface of the outer shape is rough, there is a limit to improving the accuracy of the outer dimensions of the substrate.

  The present invention has been devised in view of the above points, and an object of the present invention is to provide a method for manufacturing a substrate capable of suppressing dust during processing of the outer shape of the substrate.

  In order to achieve the above object, a method of manufacturing a substrate according to the present invention includes a step of forming a first wiring layer having a first circuit pattern on a substrate body including glass fibers, a product region of the substrate body, Forming a slit in at least a part of a boundary region which is an intermediate portion with a peripheral region outside the product region, forming an insulating layer on the first wiring layer by a molding press, and forming the insulating layer in the slit Filling the slit, filling the slit into at least a part of the outer periphery of the product region after these steps, forming the second wiring layer having the second circuit pattern on the insulating layer, and after these steps There is a step of dividing the boundary region so that the insulating layer remains.

  Here, a slit is formed in at least a part of the boundary region between the product region of the substrate body and the peripheral region which is the outer region of the product region, an insulating layer is filled in the slit, and the slit is formed in at least a part of the outer periphery of the product region. By dividing from the boundary area so that the insulating layer filled inside remains, the area where the glass fiber is exposed from the end face of the product area obtained by external processing can be reduced, and the occurrence of burrs and scratches can be reduced. Can be suppressed. Note that when the insulating layer is formed on the first wiring layer by the molding press, the slit is filled with the insulating layer, and therefore, there is no particular increase in man-hours when filling the insulating layer in the slit.

  Further, when the outer shape processing is performed by dividing from the boundary region so that the insulating layer filled in the slit remains on at least a part of the outer periphery of the peripheral region, the region where the glass fiber is exposed from the end surface of the peripheral region Can be reduced, and the occurrence of burrs and cracks can be suppressed.

  In addition, by forming the slit in the entire region of the boundary region between the product region and the peripheral region of the substrate body, the glass fiber is not exposed from the end surface of the product region or the end surface of the product region and the peripheral region. It is possible to suppress the generation of injuries.

  The above-described method for manufacturing a substrate of the present invention can suppress dust such as burrs and burrs that are generated during the outer shape processing of the substrate, thereby improving the yield of a printed circuit board with a thin film layer and the like caused by the dust. In addition, it is possible to suppress foreign matter entrainment and foreign matter adhesion during mounting.

Hereinafter, embodiments of the present invention will be described with reference to the drawings to facilitate understanding of the present invention.
In this embodiment, an example of a method for manufacturing a four-layer build-up board will be described. However, the present invention is not limited to this, and can be applied to printed wiring boards having any layer structure. For example, in the case of an 8-layer buildup substrate, a 6-layer buildup substrate before slit processing, which will be described later, may be manufactured by a general buildup process, and then slit processing may be performed.

In the method for manufacturing a printed wiring board to which the present invention is applied, first, as shown in FIG. 1A, after forming an inner layer copper foil 2 on a core material 1 in which a glass cloth is impregnated with a resin, FIG. As shown in b), an inner layer circuit is formed in a predetermined range of the inner layer copper foil by a general-purpose etching technique.
The inner layer circuit may be formed by any method such as a subtractive method, a semi-additive method, or a full additive method.

  Next, as shown in FIG. 1C, slit processing is performed on the entire boundary region between the product region 5 and the peripheral region 6 which is the outer region of the product region, thereby forming slits 8. The slit processing can be performed by a method for processing the outer shape of the printed wiring board, for example, die processing, router processing, laser processing, or the like. Moreover, you may form a slit by drilling continuously using a drilling machine.

  In this embodiment, slits are formed in the entire region of the boundary region between the product region and the peripheral region by slit processing, but even if a slit is formed in a partial region of the boundary region, dust generation is sufficiently suppressed. If possible, it is not always necessary to form slits in the entire boundary region. However, it is possible to further suppress the generation of dust by forming slits in the entire boundary region and adopting a configuration in which the glass cloth is not exposed at all from the end surface of the product region (substrate) obtained by the outer shape processing described later. .

  Here, when slits are formed in the entire region of the boundary region between the product region and the peripheral region by slit processing, there is a possibility that positional displacement occurs during the molding press described later. In view of this, when there is a concern that the positional deviation occurs, as shown in FIG. 3, the product region support portion 9 may be left without performing slit processing of a partial region of the boundary region. However, if the product area support part is left, the glass cloth of the product area support part will be exposed from the end face of the substrate during the final outline processing, and the dust reduction effect will be reduced. In addition, it is preferable to suppress misalignment using an appropriate jig, rather than using a product region support.

  Next, as shown in FIG.1 (d), shaping | molding presses, such as a prepreg and copper foil, or RCC, are performed on an inner layer copper foil, and the insulating layer 3 and the outer layer copper foil 4 are formed on an inner layer copper foil. At this time, the insulating layer resin melted by the molding press is filled in the slit formed by the slit processing and cured.

Subsequently, as shown in FIG. 2E, an outer layer circuit is formed on the outer layer copper foil in a predetermined range of the outer layer copper foil by a general-purpose etching technique.
Note that the outer layer circuit may be formed by any method such as a subtractive method, a semi-additive method, or a full additive method.

  Thereafter, as shown in FIG. 2F, the outer shape is processed so that the center line of the slit becomes the outer shape processing line, and a printed wiring board as shown in FIG. 2G can be obtained.

Here, by performing external processing so that the center line of the slit becomes the external processing line, the glass cloth is not exposed from the end face in both the product region and the peripheral region. Etc. can be suppressed.
In addition, after performing the outer shape processing, cleaning the printed wiring board and considering removing dust adhered to the surface of the printed wiring board, the glass cloth is not exposed from the end face of the product area, and the printed wiring board It is sufficient that dust can be prevented from being generated from the end face of the printed wiring board during handling, and it is not always necessary to prevent the glass cloth from being exposed from the end face of the peripheral region. However, even if the printed wiring board is cleaned after outline processing to remove the dust adhering to the surface of the printed wiring board, it is important to suppress the dust generated during outline processing as much as possible, not only the end face of the product area. In order to prevent the glass cloth from being exposed even from the end face of the peripheral region, it is preferable to perform, for example, outer shape processing such that the center line of the slit becomes the outer shape processing line.

  In the method for manufacturing a printed wiring board to which the present invention is applied, dust such as burrs and burrs on a glass cloth generated during external processing of the printed wiring board can be suppressed, and the printed wiring board with a thin film layer caused by the dust Yield can be improved, and foreign matter entrainment and foreign matter adhesion during mounting can be suppressed.

  In addition, since the printed wiring board side surface is covered with a cured resin, it is possible to improve the external dimension accuracy of the printed wiring board, and the area to be processed outside is a resin part without a glass cloth. For example, in the case of router processing or die processing, the life of the cutting tool can be improved, and in the case of laser processing, stable processing can be performed while suppressing the laser output.

It is a schematic diagram (1) for demonstrating the manufacturing method of the printed wiring board to which this invention is applied. It is a schematic diagram (2) for demonstrating the manufacturing method of the printed wiring board to which this invention is applied. It is a typical top view for explaining the modification of slit processing. It is a schematic diagram (1) for demonstrating the manufacturing method of the conventional printed wiring board. It is a schematic diagram (2) for demonstrating the manufacturing method of the conventional printed wiring board.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Core material 2 Inner layer copper foil 3 Insulating layer 4 Outer layer copper foil 5 Product area 6 Peripheral area 8 Slit 9 Product area support part

Claims (4)

Forming a first wiring layer having a first circuit pattern on a substrate body containing glass fibers;
Forming a slit in at least a part of a boundary region that is an intermediate portion between a product region of the substrate body and a peripheral region outside the product region;
Forming an insulating layer on the first wiring layer by a molding press and filling the insulating layer in the slit;
Forming a second wiring layer having a second circuit pattern on the insulating layer;
After these steps, the substrate is divided from the boundary region so that the insulating layer filled in the slit remains on at least a part of the outer periphery of the product region. The substrate manufacturing method according to claim 1, wherein the substrate is divided from the boundary region so that an insulating layer filled in the slit remains on at least a part of the outer periphery of the peripheral region. The said slit is formed in the whole area | region of the said boundary area. The manufacturing method of the board | substrate of Claim 1 characterized by the above-mentioned. The said slit is formed in the whole area | region of the said boundary area. The manufacturing method of the board | substrate of Claim 2 characterized by the above-mentioned.

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