JP2015220393A - Support substrate for circuit formation, printed wiring board using the same, and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a support substrate the end of which is bonded sufficiently, and to provide a printed wiring board using the same, and a method of manufacturing the same.SOLUTION: An insulating resin layer 5 is bonded to an adhesive resin layer 3 arranged on a support 2, via a copper foil 4 with a carrier having a size smaller than that of the support 2 and adhesive resin layer 3, in a support substrate 1 for circuit formation. Alternatively, an insulating resin layer 5 is bonded to an adhesive resin layer 3 arranged on a support 2, via more than one metal foil 8 having a size smaller than that of the support 2 and adhesive resin layer 3, in a support substrate 1 for circuit formation. A printed wiring board using the same, and a method of manufacturing the same are also provided.

Description

  The present invention relates to a circuit-forming support substrate, a printed wiring board using the same, and a method for manufacturing the same.

  In recent years, electronic devices have been further reduced in size, weight, and multifunction, and accordingly, higher integration and miniaturization of wiring are rapidly progressing, and printed wiring boards are becoming thinner. In order to cope with this, conventionally, there is a coreless method in which a printed wiring board is obtained by separating from a temporary substrate after forming a wiring layer in a state where it can be peeled off from the temporary substrate.

In Patent Document 1, a copper-clad laminate, a copper foil that is directly disposed on the copper foils on both sides of the copper-clad laminate, and a size smaller than the copper foil of the copper-clad laminate and the copper-clad laminate, A method of obtaining a printed wiring board using a circuit-forming support substrate (substrate for coreless method) having an insulating resin layer having a size larger than the copper foil is described.
Japanese Patent No. 5029911

  However, in the support substrate for circuit formation described in Patent Document 1, when the prepreg used for the insulating resin layer is made thin in order to produce a thinner printed wiring board, or when the resin content of the prepreg used is reduced, The insulating resin in the portion is insufficient, and the copper-clad laminate and the insulating resin layer (prepreg) may not be sufficiently bonded. If it does so, in the manufacturing process of a printed wiring board, a plating solution and an etching solution may permeate from an end portion where adhesion is insufficient.

  Also, if the thickness of the slightly smaller copper foil placed between the insulating resin layer and the copper clad laminate is thicker than the prepreg used for the insulating resin layer, the resin of the insulating resin layer is insufficient, It becomes difficult to embed the height of the copper foil, and the end portion of the copper foil having a slightly smaller size may not be sufficiently protected.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a support substrate for forming a circuit in which ends are sufficiently bonded, a printed wiring board using the same, and a method for manufacturing the same. There is.

As a result of investigations to solve the above problems, the present inventors have found that the problems can be solved by the present invention described below.
That is, the present invention provides the following [1] to [5].
[1] A circuit-forming support substrate in which an insulating resin layer is bonded to an adhesive resin layer disposed on a support via a carrier-attached copper foil having a smaller size than the support and the adhesive resin layer.
[2] A circuit-forming support substrate in which an insulating resin layer is bonded to an adhesive resin layer disposed on a support via two or more metal foils having a size smaller than that of the support and the adhesive resin layer.
[3] The circuit-forming support substrate according to [1] or [2], wherein the support is a metal-clad laminate.
[4] The circuit-forming support substrate according to [1] or [2], wherein the support is a metal foil.
[5] A printed wiring board manufactured using the circuit-forming support substrate of the above [1] to [4].

  ADVANTAGE OF THE INVENTION According to this invention, the support substrate for circuit formation to which the edge part was fully adhere | attached, a printed wiring board using the same, and its manufacturing method can be provided.

Hereinafter, embodiments of the present invention will be described in detail.
In the first form of the circuit-forming support substrate of the present invention, the insulating resin layer is bonded to the adhesive resin layer disposed on the support via a copper body with a carrier smaller than the support and the adhesive resin layer. It is a thing.
In FIG. 1, an example of the 1st form of the support substrate for circuit formation of this invention is shown. As the first form of the circuit-forming support substrate of the present invention, for example, a copper-clad laminate is used for the support 2, prepregs are disposed as adhesive resin layers 3 on both sides thereof, and the support 2 and the adhesive are bonded. Manufactured by placing copper foil 4 (copper foil with carrier) smaller than resin layer 3, placing prepreg as insulating resin layer 5 and copper foil 6 corresponding to the outer layer, and adhesively laminating by heating and pressing. it can.

  The copper foil 4 is near the center of the support 2, the adhesive resin layer 3, and the insulating resin layer 5 so that the support 2, the adhesive resin layer 3, and the insulating resin layer 5 are bonded at the ends of the four sides of the copper foil 4. It is preferable to arrange to. Further, the size of the copper foil 4 is preferably smaller than the size of the support 2 by 10 mm or more in both the vertical and horizontal directions. The sizes of the adhesive resin layer 3, the insulating resin layer 5, and the copper foil 6 are preferably larger than the support 2.

  When the end surface of the circuit forming support substrate is cut after the adhesive lamination by heating and pressing the circuit forming support substrate, it is preferably cut outside the end surface of the copper foil 4 by 5 mm or more per side.

  From the viewpoint of obtaining a good peel strength between the insulating resin layer and the copper foil, it is preferable to arrange the roughened surface of the copper foil 4 so as to adhere to the insulating resin layer 5. In addition, in order to increase the adhesive strength between the support 2 and the adhesive resin layer 3, a treatment for forming a bumpy electrodeposit layer (called “bathing plating on bath”) on the copper foil surface of the support 2, oxidation treatment, reduction Processing, etching, and the like may be performed.

  Although it does not specifically limit as a board | substrate used as the support body 2, Substrates, such as a resin substrate, a metal-clad laminated board, a metal plate, metal foil, can be used. Among these, it is preferable to use a copper clad laminate. Although the copper clad laminate is not particularly limited, for example, a copper foil is disposed on both surfaces of a prepreg, a film material, and a base material in which an adhesive is disposed on both surfaces of the metal plate, and heat and pressure bonding is performed. A copper clad laminated board is mentioned.

The prepreg used for the support 2, the adhesive resin layer 3, and the insulating resin layer 5 is formed by impregnating or coating an insulating resin composition on a base material.
As a base material, the well-known thing used for the laminated board for various electrical insulation materials can be used. Examples of the substrate include inorganic fibers such as E glass, D glass, S glass, and Q glass, organic fibers such as polyimide, polyester, and tetrafluoroethylene, and mixtures thereof. Examples of the shape of these base materials include woven fabrics, non-woven fabrics, robinks, chopped strand mats, and surfacing mats.
The material and shape of the substrate can be selected depending on the intended use and performance of the molded product. Moreover, you may use it individually or in combination of 2 or more types of materials and shapes as needed.
Although the thickness of a base material is not specifically limited, The thing of about 0.03-0.5 mm can be used normally. In addition, those surface-treated with a silane coupling agent or the like or mechanically subjected to a fiber opening treatment are preferable from the viewpoints of heat resistance, moisture resistance, and workability.

The insulating resin composition used for the prepreg is not particularly limited, and a known resin composition used as an insulating material for a printed wiring board can be used. As a resin component mix | blended with an insulating resin composition, thermosetting resin with favorable heat resistance and chemical resistance is mentioned, for example. The thermosetting resin is not particularly limited, and examples thereof include phenol resin, epoxy resin, cyanate resin, maleimide resin, isocyanate resin, benzocyclobutene resin, and vinyl resin. These may be used alone or in combination of two or more.
Furthermore, the insulating resin composition is blended with various additives such as inorganic fillers, organic fillers, curing agents, curing accelerators, colorants, UV opaquers, antioxidants, and reducing agents as necessary. May be.
After impregnating or coating the base material so that the amount of the insulating resin composition attached to the base material is 20 to 90% in terms of the resin content of the prepreg after drying, it is usually 1 to 30 at a temperature of 100 to 200 ° C. A prepreg in a semi-cured state (B stage state) can be obtained by heat drying for a few minutes.

The copper foil 4 is preferably a copper foil with a carrier having a copper foil thickness of 1 μm or more. The copper foil with a carrier is a copper foil having a carrier and is a copper foil that can be peeled off by the carrier. The copper foil with a carrier, for example, forms a metal oxide film or an organic layer as a peeling layer on a carrier having a thickness of 10 to 50 μm, and a copper sulfate bath on the metal oxide film or an organic substance layer, the sulfuric acid 50 to 100 g / L, copper 30 to In the case of 100 g / L, liquid temperature 20-80 ° C., current density 0.5-100 A / dm ² , copper pyrophosphate bath, potassium pyrophosphate 100-700 g / L, copper 10-50 g / L, liquid temperature 30 A copper foil having a thickness of 0.1 to 3.0 μm can be formed and produced under the conditions of ˜60 ° C., pH 8 to 12, and current density of 0.5 to 10 A / dm ² .
From the viewpoint of punchability, it is preferable to use copper, nickel, tin, zinc, chromium, molybdenum, cobalt, or an alloy thereof for the carrier.

Although it does not specifically limit as the copper foil 6, It is preferable to use the above-mentioned copper foil with a carrier and the average roughness (Rz) of 10 points | pieces shown to JISB0601 2.0-5.0 micrometers. As the production conditions of the copper foil, for example, in the case of a copper sulfate bath, sulfuric acid 50-100 g / L, copper 30-100 g / L, liquid temperature 20-80 ° C., current density 0.5-100 A / dm ² , In the case of a copper pyrophosphate bath, it is manufactured under the conditions of potassium pyrophosphate 100 to 700 g / L, copper 10 to 50 g / L, liquid temperature 30 to 60 ° C., pH 8 to 12, and current density 0.5 to 10 A / dm ^2. Can do. Various additives may be used in consideration of the physical properties and smoothness of copper.

Next, a second embodiment of the circuit forming support substrate of the present invention will be described.
According to a second embodiment of the circuit-forming support substrate of the present invention, the insulating resin layer has two or more metal foils smaller in size than the support and the adhesive resin layer interposed in the adhesive resin layer disposed on the support. Are glued together.
In FIG. 2, an example of the 2nd form of the support substrate for circuit formation of this invention is shown. As a second form of the circuit-forming support substrate of the present invention, for example, a double-sided roughened copper foil is used for the support 7, prepregs are disposed as adhesive resin layers 3 on both sides thereof, and the support 7 and Two copper foils 8 having a size smaller than that of the adhesive resin layer 3 are arranged so that the glossy surfaces thereof face each other, a prepreg as the insulating resin layer 5 and the copper foil 6 corresponding to the outer layer are arranged, and bonded by heating and pressing. It can be manufactured by laminating.

  The copper foil 8 is near the center of the support 7, the adhesive resin layer 3, and the insulating resin layer 5 so that the support 7, the adhesive resin layer 3, and the insulating resin layer 5 are bonded at the ends of the four sides of the copper foil 8. It is preferable to arrange to. The size of the copper foil 8 is preferably smaller than the size of the support 7 by 10 mm or more in both the vertical and horizontal directions. The sizes of the adhesive resin layer 3, the insulating resin layer 5, and the copper foil 6 are preferably larger than the support 7.

  When the end surface of the circuit forming support substrate is cut after the adhesion and lamination of the circuit forming support substrate by heating and pressing, it is preferably cut outside the end surface of the copper foil 8 by 5 mm or more per side.

  From the viewpoint of obtaining a good peel strength between the insulating resin layer and the copper foil, the roughened surface of the copper foil 8 is preferably disposed so as to adhere to the insulating resin layer 5 and the adhesive resin layer 3, respectively. In order to increase the adhesive strength between the support 7 and the adhesive resin layer 3, the surface of the support 7 is preferably subjected to a roughening treatment on both sides.

  The support 7 is not particularly limited, and a substrate such as a resin substrate, a metal-clad laminate, a metal plate, or a metal foil can be used.

The copper foil 8 preferably has an average roughness (Rz) at 10 points shown in JISB0601 of 2.0 μm to 5.0 μm. As a manufacturing condition of such a copper foil, for example, in the case of a copper sulfate bath, sulfuric acid 50-100 g / L, copper 30-100 g / L, liquid temperature 20-80 ° C., current density 0.5-100 A / dm ² In the case of a copper pyrophosphate bath, potassium pyrophosphate 100-700 g / L, copper 10-50 g / L, liquid temperature 30-60 ° C., pH 8-12, current density 0.5-10 A / dm ² Can be manufactured. Various additives may be used in consideration of the physical properties and smoothness of copper.

Hereinafter, the present invention will be described with reference to the embodiments shown in FIGS. 3 and 4, but these embodiments do not limit the present invention.
In FIG. 3 as a first example, the nominal thickness of 0.1 mm having a copper foil with a thickness of 18 μm on both sides, the nominal thickness of 0.1 mm on both sides of the support 2 (copper-clad laminate) of size 614 × 514 mm, One adhesive resin layer 3 (prepreg) having a size of 625 × 525 mm was disposed in the vicinity of the center of the support 2 to form a substrate 10.

  A copper foil 4 having a size of 580 × 480 mm (copper foil with a carrier) in which a carrier copper foil having a thickness of 18 μm is bonded to an ultrathin copper foil having a thickness of 5 μm on both surfaces of the substrate 10 is disposed in the vicinity of the center of the substrate 10. In addition, the carrier copper foil surface of the copper foil 4 was disposed so as to face the adhesive resin layer 3, thereby forming a substrate 20.

  An insulating resin layer 5 having a nominal thickness of 0.02 mm and a size of 625 × 525 mm was superimposed on both surfaces of the substrate 20, and a carrier copper foil having a thickness of 18 μm was bonded to an ultrathin copper foil having a thickness of 5 μm as a copper foil 6. A copper foil with a carrier having a size of 650 × 550 mm was constructed such that an ultrathin copper foil having a thickness of 5 μm was adhered to the insulating resin layer 5, and vacuum pressing was performed. After the pressing, the end portion was cut to a size of 607 × 508 mm to obtain a substrate 30 (support substrate for circuit formation).

  A conformal mask was formed on the substrate 30 at a portion to be a non-through hole installation place for connection to the substrate 20, and the substrate 40 was obtained.

  Non-through holes were formed on both surfaces of the substrate 40 one by one with a carbon dioxide laser processing machine to form a substrate 50.

  The substrate 50 was subjected to desmear treatment, plated with a thickness of 0.4 to 0.8 μm by electroless copper plating, and then plated with a thickness of 15 to 20 μm by electrolytic copper plating to obtain a substrate 60. Thereby, the board | substrate 20 (copper foil 4) and the board | substrate 30 (copper foil 6) were electrically connected by the non-through-hole.

  In the substrate 60, within the arrangement range of the copper foil 4 in the substrate 20, a size of 540 × 440 mm is cut by a router processing machine, separated from the substrate 10, and an insulating resin substrate (substrate 70) connected between the layers is obtained. Obtained.

  The surface of the substrate 70 was adjusted and a dry film resist was laminated. Thereafter, a circuit pattern was baked, a resist pattern, a resist pattern, a wiring pattern was formed by etching and resist removal, and a substrate 80 was obtained.

  A substrate 90 was obtained by performing solder resist formation and gold plating on the substrate 80 and cutting the pattern size.

  As a second embodiment, in FIG. 4, the adhesive resin layer 3 (prepreg) having a nominal thickness of 0.1 mm and a size of 625 × 525 mm is formed on both surfaces of a support 7 (double-side roughened copper foil) having a thickness of 35 μm and a size of 614 × 514 mm. ) On one side of the support 7 to form a substrate 15.

  Two copper foils 8 having a thickness of 12 μm and a size of 580 × 480 mm were placed on both sides of the substrate 15 in the vicinity of the center of the substrate 10 with the respective glossy surfaces facing each other.

  An insulating resin layer 5 (prepreg) having a nominal thickness of 0.02 mm and a size of 625 × 525 mm is disposed on both surfaces of the substrate 25, and further, as a copper foil 6, an ultrathin copper foil having a thickness of 5 μm and a carrier copper foil having a thickness of 18 μm. A copper foil with a carrier having a size of 650 × 550 mm was configured such that a 5 μm ultrathin copper foil was bonded to the insulating resin layer 5, and vacuum pressing was performed. After pressing, the end portion was cut to a size of 607 × 508 mm to obtain a substrate 35 (circuit forming support substrate).

  A conformal mask was formed on a portion of the substrate 35 where a non-through hole was placed for connection with the substrate 25 to form a substrate 45.

  Non-through holes were formed on both surfaces of the substrate 45 one by one with a carbon dioxide laser processing machine to form a substrate 55.

  The substrate 55 was subjected to desmear treatment, plated with a thickness of 0.4 to 0.8 μm by electroless copper plating, and then plated with a thickness of 15 to 20 μm by electrolytic copper plating to obtain a substrate 65. Thereby, the board | substrate 25 (copper foil 8) and the board | substrate 35 (copper foil 6) were electrically connected by the non-through-hole.

  In the substrate 65, the insulating resin substrate separated from the substrate 15 and connected between the layers by cutting with a router processing machine so as to have a size of 540 × 440 mm within the arrangement range of the copper foil 8 in the substrate 20 75.

  Surface conditioning of the substrate 75 was performed, and a dry film resist was laminated. Thereafter, the circuit pattern was baked, a resist pattern was developed, etched, and a resist pattern was formed to form a substrate 85.

  The board | substrate 95 was obtained by performing soldering resist formation and gold plating finishing with respect to the board | substrate 85, and giving a cutting process to pattern size.

  The end portions of the circuit-forming support substrates produced in the first and second embodiments of the present invention were sufficiently bonded, and the penetration of the plating solution and the etching solution could be prevented.

Explanatory drawing of the 1st form of the support substrate for circuit formation of this invention Explanatory drawing of the 2nd form of the support substrate for circuit formation of this invention Explanatory drawing of the first embodiment Explanatory drawing of 2nd Example

1 Support substrate for circuit formation 2 Support (copper-clad laminate)
3 Adhesive resin layer 4 Copper foil (copper foil with carrier)
5 Insulating resin layer 6 Copper foil 7 Support (Roughening of copper foil on both sides)
8 Copper foil

Claims (5)

  A circuit-forming support substrate in which an insulating resin layer is bonded to an adhesive resin layer disposed on a support via a copper foil with a carrier having a size smaller than that of the support and the adhesive resin layer.   A circuit-forming support substrate in which an insulating resin layer is bonded to an adhesive resin layer disposed on a support via two or more metal foils having a size smaller than that of the support and the adhesive resin layer.   The circuit-forming support substrate according to claim 1, wherein the support is a metal-clad laminate.   The circuit-forming support substrate according to claim 1, wherein the support is a metal foil.   A printed wiring board manufactured using the circuit-forming support substrate according to claim 1.

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