JP2007150171A - Manufacturing method for wiring board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method for wiring board that can efficiently manufacture a thin wiring board with high density. <P>SOLUTION: The manufacturing method for wiring board includes the stages of preparing a base substrate 1, which has a flat main surface; forming an adhesive layer 2 whose adhesive strength is lost or decreased by irradiation with ultraviolet rays on the main surface of the base substrate 1; forming a laminate 10 for wiring board which comprises conductor layers 3, 5a, 5b, 5c, and 5d and insulating layers 4a, 6a, 6b, 6c, and 4b, by alternately laminating pluralities of conductor layers 3, 5a, 5b, 5c, and 5d and insulating layers 4a, 6a, 6b, 6c, and 4b on the adhesive layer 2; irradiating the adhesive layer 2 with ultraviolet rays to lose or decrease the adhesive strength of the adhesive layer 2; and peeling the laminate 10 off the adhesive layer 2 whose adhesive strength is lost or reduced. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a wiring board used for mounting electronic components such as semiconductor elements.

  Conventionally, a core substrate having wiring conductors made of copper foil on both surfaces of a glass-resin plate having a thickness of about 0.2 to 2.0 mm as a high-density multilayer wiring substrate used for mounting electronic components such as semiconductor elements There is known a build-up wiring board in which insulating layers made of a resin having a thickness of about 10 to 100 μm and wiring conductors made of a plating film are alternately laminated on the both surfaces. Such a build-up wiring board is manufactured, for example, by the method described below.

  First, an insulating sheet in which a glass cloth is impregnated with a thermosetting resin such as an epoxy resin or a bismaleimide triazine resin is prepared. Next, copper foil is stuck on both sides of the insulating sheet, and the thermosetting resin in the insulating sheet is thermoset to obtain a double-sided copper-clad plate. Next, a through-hole penetrating the upper and lower surfaces of the double-sided copper-clad plate is drilled, and a plating film is deposited on the inner wall of the through-hole to electrically connect the upper and lower copper foils with the plating film in the through-hole. . Next, after filling the through hole with resin, the upper and lower copper foils are etched into a predetermined pattern to obtain a core substrate having wiring conductors made of copper foil on both surfaces of the glass-resin plate.

  Next, a resin film in which an inorganic insulating filler is dispersed in a thermosetting resin such as epoxy resin or bismaleimide triazine resin is attached to the upper and lower surfaces of the core substrate, and the thermosetting resin in the resin film is thermoset. To form an insulating layer. Next, via holes are drilled in the insulating layer by laser processing, and wiring conductors made of plating films are simultaneously formed on the surface of the insulating layer including the inside of the via holes by a semi-additive method. In addition, by repeating the formation of the next insulating layer and the wiring conductor a plurality of times, the wiring made of the insulating layer and the plating film made of resin on both sides of the core substrate having the wiring conductor made of copper foil on both sides of the glass-resin plate A build-up wiring board formed by alternately laminating conductors is manufactured.

  However, in such a build-up wiring board, since insulating layers made of a resin and wiring conductors made of a plating film are alternately laminated on both surfaces of the core board, the insulating layers and the wiring conductors are sequentially multilayered. Although high-density wiring is possible by using a glass-resin plate having a thickness of about 0.2 to 2.0 mm as the core substrate, it is difficult to reduce the overall thickness of the wiring substrate. There was a point.

Therefore, in Patent Document 1, a wiring conductor and an insulating layer are sequentially formed on one surface side of a metal plate from the semiconductor element mounting surface side to the external connection terminal mounting surface side, and then the metal plate is etched away. Thus, a method of manufacturing a multilayer substrate for a semiconductor device has been proposed. According to the method disclosed in Patent Document 1, a semiconductor device mounting surface is flat and a thin multilayer substrate for a semiconductor device can be provided. However, according to this method, it is necessary to etch away a metal plate that requires a relatively large thickness, and the etching takes a long time. Further, since it is necessary to remove the metal plate by etching, it is not possible to form the substrate on both surfaces of the metal plate, and there is a problem to be solved that the production efficiency is low.
Japanese Patent No. 3635219

  The subject of this invention is providing the manufacturing method of the wiring board which can manufacture a thin and high-density wiring board efficiently.

  The method for manufacturing a wiring board according to the present invention includes a step of preparing a support substrate having a flat main surface, and an adhesive layer on which the adhesive force disappears or decreases due to ultraviolet irradiation on the main surface of the support substrate. A step of attaching, a step of alternately laminating a plurality of conductor layers and insulating layers on the adhesive layer to form a laminate for the wiring board comprising the conductor layer and the insulating layer, and the adhesive layer And irradiating the substrate with ultraviolet rays to lose or reduce the adhesive strength of the adhesive layer, and peeling the laminate from the adhesive layer with lost or reduced adhesive strength. It is.

  According to the method for manufacturing a wiring board of the present invention, an adhesive layer whose adhesive strength is lost or reduced by irradiation of ultraviolet rays is deposited on the main surface of the support substrate, and then the wiring conductor layer and the adhesive layer are formed on the adhesive layer. A plurality of insulating layers are alternately laminated to form a laminated body for a wiring board composed of the wiring conductor layer and the insulating layer, and then the adhesive layer loses its adhesive strength by irradiating the adhesive layer with ultraviolet rays. Alternatively, after being lowered, the laminate is peeled off from the adhesive layer, so that the laminate for a wiring board can be easily separated in a short time only by irradiation with ultraviolet rays, thereby forming a thin and high-density wiring board. It can be manufactured efficiently. Further, after forming the adhesive layer and the laminate on both main surfaces of the support substrate, respectively, the adhesive layer is irradiated with ultraviolet rays from the lateral direction of the support substrate to lose the adhesive force of the adhesive layer or After the reduction, it is possible to separate the laminates on both main surfaces, and in this case, the production efficiency of the laminate can be doubled.

  Next, an example of a method for manufacturing a wiring board in the present invention will be described in detail with reference to the drawings. 1 to 4 are schematic views for each process for explaining a method of manufacturing a wiring board according to the present invention. Among these, in FIGS. 1 and 2, an adhesive layer is deposited on the main surface of the support substrate, and insulating layers and wiring conductors are alternately stacked thereon to form a laminate for the wiring substrate. FIG. 3 is a schematic diagram showing a process, and FIG. 3 is a schematic diagram showing a process of peeling a laminate for a wiring board from an adhesive layer on a support substrate. FIG. It is a schematic sectional drawing which shows the wiring board formed by giving a process.

  First, as shown in FIG. 1A, a support substrate 1 having a flat main surface is prepared. The support substrate 1 is a substantially rectangular flat plate having a thickness of about 5 to 10 mm and a side length of about 300 to 1000 mm made of a hard light-transmitting material such as glass, ceramics, or hard resin that can transmit ultraviolet rays. It functions as a temporary support for temporarily supporting a laminate 10 for a wiring board to be described later on the surface.

  Next, as shown in FIG. 1 (b), an adhesive layer 2 whose adhesive strength disappears or decreases when irradiated with ultraviolet rays is applied to one main surface of the support substrate 1. The adhesive layer 2 contains an acrylic adhesive polymer (for example, 2-ethylhexyl acrylate and acrylic acid), an ultraviolet curable oligomer (for example, urethane acrylate oligomer), a photoinitiator (for example, 1-hydroxycyclohexyl phenyl ketone), and the like. The adhesive resin material paste is applied to the main surface of the support substrate 1 and then dried, or the film of the adhesive resin material is adhered to the main surface of the support substrate 1. When the adhesive layer 2 is irradiated with ultraviolet rays, a radical reaction from the photoinitiator to the ultraviolet curable oligomer starts, which acts on the oligomer, and the ultraviolet curable oligomer is polymerized. As a result, the adhesive strength disappears or decreases.

  Next, as shown in FIG. 1C, the auxiliary conductor layer 3 is laminated on the surface of the adhesive layer 2. The auxiliary conductor layer 3 is made of, for example, a metal foil having a thickness of about 3 to 20 μm, and functions as a boundary layer for facilitating the peeling when the laminate 10 for a wiring board described later is peeled from the adhesive layer 2. To do. In addition, the adhesive layer 2 is previously applied to one side of the auxiliary conductor layer 3, and the adhesive layer 2 and the auxiliary conductor layer 3 are bonded by attaching the adhesive layer 2 to the main surface of the support substrate 1. You may laminate | stack on the main surface of the support substrate 1 simultaneously.

  Next, as shown in FIG. 1D, the first insulating layer 4 a for the solder resist layer is laminated on the auxiliary conductor layer 3. The first insulating layer 4a is made of, for example, an electrically insulating material in which an inorganic powder filler such as silica or talc is dispersed in an acrylic modified epoxy resin by about 30 to 70% by mass, and is photopolymerized with a photosensitive resin such as an acrylic modified epoxy resin. A photosensitive resin paste containing an inorganic insulating filler such as silica or talc in a mixture composed of an initiator and the like is applied to a thickness of about 10 to 30 μm by screen printing or a roll coating method, and then photolithography technology After being exposed to light and developed in a predetermined pattern using UV, it is formed by ultraviolet curing and heat curing. Note that an opening A for forming a semiconductor element connection pad in the wiring substrate obtained by the manufacturing method of this example is formed in the first insulating layer 4a.

  Next, as shown in FIG. 2A, a first wiring conductor layer 5a is formed in a predetermined pattern on the surface of the first insulating layer 4a and in the opening A. The first wiring conductor layer 5a is made of, for example, an electroless copper plating film and an electrolytic copper plating film, and is formed by a known semi-additive method. Specifically, first, the surface of the first insulating layer 4a is roughened as necessary, and then an electroless copper plating film is deposited on the surface to a thickness of about 0.1 to 2.0 μm. Next, a plating resist layer having an opening corresponding to the first wiring conductor layer 5a is formed on the surface of the electroless copper plating film. The plating resist layer has the opening by sticking a photosensitive resin film on the electroless copper plating film and subjecting the resin film to exposure / development processing using a photolithography technique. Formed as follows. Next, the electrolytic copper plating film is deposited to a thickness of about 5 to 30 μm on the electroless copper plating film exposed in the opening of the plating resist layer. Next, the plating resist layer is peeled off. Finally, the first wiring conductor layer 5a is formed by etching the electroless copper plating film and the exposed portions of the electrolytic copper plating film as a whole until the electroless copper plating film between the electrolytic copper plating films disappears.

  Next, as shown in FIG. 2B, a second insulating layer 6a for wiring conductor interlayer insulation is formed on the first insulating layer 4a and the first wiring conductor layer 5a. The second insulating layer 6a is made of an electrically insulating material in which an inorganic insulating filler is dispersed in a thermosetting resin such as an epoxy resin or a bismaleimide triazine resin, and the thermosetting resin such as an epoxy resin or a bismaleimide triazine resin. A resin film having a thickness of about 10 to 100 μm, in which an inorganic insulating filler is dispersed in an uncured material, is pasted on the first insulating layer 4a and the first wiring conductor layer 5a, and thermosetting in the resin film is performed. It is formed by thermosetting a functional resin. A via opening V for exposing a part of the first wiring conductor layer 5a is formed in the second insulating layer 6a. The opening V is formed by laser processing. Alternatively, the film for the second resin layer 6a is provided with photosensitivity, and is formed by applying exposure / development processing using a photolithography technique.

  Subsequently, as shown in FIG. 2C, the second wiring conductor layer 5b is formed on the second insulating layer 6a, the third insulating layer 6b is formed thereon, and the fourth wiring conductor layer is formed thereon. 5c, the fourth insulating layer 6c, the fifth wiring conductor layer 5d, and the fifth insulating layer 4b are sequentially formed to form the multilayer body 10 for the wiring board. The second to fifth wiring conductor layers 5b to 5d are composed of an electroless copper plating film and an electrolytic copper plating film similar to the first wiring conductor layer 5a, and are similar to the first wiring conductor layer 5a. It is formed by the additive method. The third and fourth insulating layers 6b and 6c are made of the same electrical insulating material as the second insulating layer 6a and are formed by the same method as the second insulating layer 6a. Furthermore, the fifth insulating layer 4b is made of the same electrical insulating material as that of the first insulating layer 4a, and is formed by the same method as that for the first insulating layer 4a.

  Next, as shown in FIG. 3A, the adhesive layer 2 is irradiated with ultraviolet rays through the support substrate 1, and the adhesive strength of the adhesive layer 2 is lost or reduced.

  Next, as shown in FIG. 3B, the laminate 10 for a wiring board is peeled off from the adhesive layer 2 whose adhesive strength has been lost or reduced. At this time, since the adhesive strength of the adhesive layer 2 disappears or decreases due to the irradiation of ultraviolet rays, the laminate 10 for a wiring board can be easily peeled from the adhesive layer 2 in a short time.

  Next, as shown in FIG. 4, the auxiliary conductor layer 3 is removed by etching from the laminate 10 for the wiring board, thereby completing the wiring board 20. At this time, since the auxiliary conductor layer 3 is as thin as about 3 to 20 μm, it can be removed by etching in a short time.

  In the above-described example, the case where the laminated body 10 for the wiring board is formed on one main surface of the support substrate 1 has been described. However, as shown in FIG. The laminated body 10 may be formed. In this case, compared with the case where the laminated body 10 is formed only on one main surface of the support substrate 1, the efficiency of forming the laminated body 10 can be increased approximately twice. In this case, the adhesive force of the adhesive layer 2 is lost or reduced by irradiating ultraviolet rays from the side surface of the support substrate 1.

  Thus, according to the method for manufacturing a wiring board of the present invention, a thin and high-density wiring board can be efficiently manufactured. Note that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the present invention.

It is a schematic sectional drawing for demonstrating the manufacturing method of the wiring board of this invention. It is a schematic sectional drawing for demonstrating the manufacturing method of the wiring board of this invention. It is a schematic sectional drawing for demonstrating the manufacturing method of the wiring board of this invention. It is a schematic sectional drawing for demonstrating the manufacturing method of the wiring board of this invention. It is a schematic sectional drawing for demonstrating the manufacturing method of the wiring board of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Support substrate 2 Adhesive layer 3, 5a, 5b, 5c, 5d Conductive layer 4a, 4b, 6a, 6b, 6c Insulating layer 10 Laminate for wiring boards 20 Wiring board

Claims (1)

A step of preparing a support substrate having a flat main surface, a step of depositing an adhesive layer on which the adhesive force disappears or decreases due to irradiation of ultraviolet rays on the main surface of the support substrate, and on the adhesive layer A plurality of conductor layers and insulating layers alternately laminated to form a laminate for a wiring board comprising the conductor layers and the insulating layers, and the adhesive layer is irradiated with ultraviolet rays. A method of manufacturing a wiring board comprising: a step of eliminating or reducing the adhesive strength of the substrate; and a step of peeling the laminate from the adhesive layer where the adhesive strength has been lost or reduced.