JP6417765B2 - Laminate for wiring board, wiring board using the same, and manufacturing method thereof - Google Patents

Description

  The present invention relates to a laminate for a wiring board having a laser via for interlayer connection, a wiring board using the same, and a method for manufacturing the same, and in particular, a laminate for a wiring board in which interlayer connection between laser vias is formed by filled via plating, The present invention relates to a wiring board using the same and a manufacturing method thereof.

  In recent years, the thickness of an insulating layer used for a wiring board has become thinner as the density and thickness of the wiring board have increased. In addition, as the diameter of parts decreases, the remaining copper ratio (same area ratio per product) decreases, and the deformation of the insulating layer tends to increase.

As a wiring board manufacturing method using such a thin insulating layer, a wiring board manufacturing method using a so-called coreless method is disclosed. (Patent Document 1). Moreover, in order to improve the rigidity in a wiring board having a thin insulating layer and suppress warping, a wiring board is disclosed in which a dummy slit is provided and the plating is filled (Patent Document 2).

JP 2012-099857 A JP 2007-067010 A

  In the method for manufacturing a wiring board using the coreless construction method of Patent Document 1, there is a problem in that the shrinkage of the wiring board after separation causes variations in alignment accuracy. In addition, in the wiring board of Patent Document 2, when a slit is formed in a closed shape that is surrounded by a lattice to form a dummy slit, a portion surrounded by the closed shape may fall off the substrate. Depending on the size and arrangement of the dummy slits, there is a problem that the shape and arrangement for forming the slits are greatly limited because the dummy slits are deformed before filling.

  Therefore, it has a rigid structure with a large degree of freedom in arrangement and shape, and for wiring boards that can suppress the shrinkage of the wiring board physically and reduce deformation due to the shrinkage that occurs in the lamination process, and enables high alignment accuracy And a wiring board using the same and a method for manufacturing the same.

The present invention relates to the following.
1. An insulating layer, a conductor layer disposed on the front and back surfaces of the insulating layer, and an interlayer connection extending from the one conductor layer through the insulating layer to the other conductor layer, wherein the interlayer connection is an interlayer A laminate for a wiring board, comprising a connection hole and a plating filled in the interlayer connection hole, and arranged in a line with discontinuous dots.
2. Item 1 includes a plurality of product regions that are products, a boundary region that is disposed so as to surround each of the plurality of product regions, and an outer frame region that is disposed so as to surround the plurality of product regions. A laminate for a wiring board in which the interlayer connection is arranged in a boundary region surrounding each of the plurality of product regions and arranged in a lattice shape in plan view.
3. In the item 1 or 2, the interlayer connection is arranged in multiple lines in a discontinuous dot form, and the positions of the interlayer connections arranged in the multiple line form are arranged in a line. Is a laminated body for a wiring board, which is arranged so as to have a deviation in the direction arranged in a linear manner between interlayer connections adjacent in the vertical direction.
4). Item 4. The laminated body for a wiring board according to any one of Items 1 to 3, wherein an interlayer connection from the one conductor layer through the insulating layer to the other conductor layer is a non-through hole.
5. Item 5. The laminated body according to any one of items 1 to 4, wherein the laser via has a diameter of 40 μm to 200 μm.
6). Item 6. The laminated body for a wiring board according to any one of Items 1 to 5, wherein the distance between the inner walls of the laser vias is 1 to 50 μm in the direction arranged in the form of discontinuous dots.
7). Item 5. A wiring board manufactured using the laminate according to any one of Items 1 to 4.
8). Item 8. The method for manufacturing a wiring board according to Item 7, wherein discontinuous dot-shaped interlayer connection holes are formed in a line on the surface of a double-sided metal foil-clad laminate in which metal foil is disposed on the front and back surfaces of the insulating layer. Step (a), filling the formed interlayer connection hole with plating, forming the plating on the metal foil (b), and etching process to process the metal foil and the plating on the metal foil. And a step (c) of forming a wiring.

  According to the present invention, it has a rigid structure with a large degree of freedom of arrangement and shape, and by physically suppressing the shrinkage of the wiring board, there is little deformation due to shrinkage that occurs in the lamination process, and high alignment accuracy is possible. It is possible to provide a laminate for a wiring board, a wiring board using the same, and a method for manufacturing the same.

It is a top view of one embodiment of a layered product for wiring boards of the present invention. It is a flowchart showing one Embodiment of the manufacturing method of the laminated body for wiring boards of this invention, and this. Steps (a) and (b) are cross-sectional views in the direction in which the interlayer connection holes are arranged in a line, and step (c) is a cross-sectional view in the direction perpendicular to the direction in which the interlayer connection holes are arranged in a line. Show. It is a top view which shows the example of arrangement | positioning of the laser via of the laminated body for wiring boards of this invention, and the manufacturing method of a wiring board.

(Laminated body for wiring board)
As an embodiment of the wiring board of the present invention, as shown in FIG. 2, the insulating layer 6, conductor layers 5 and 13 disposed on the front and back surfaces of the insulating layer 6, and the one conductor layer 13 to the insulating layer. An interlayer connection 7 that passes through 6 and reaches the other conductor layer 5. The interlayer connection 7 includes an interlayer connection hole 2 and a plating 8 filled in the interlayer connection hole 2, and is discontinuous. Examples thereof include a laminate 1 for a wiring board arranged in a line in the form of dots (dots). Hereinafter, the laminate 1 for a wiring board is sometimes simply referred to as the laminate 1.

  The insulating layer in this embodiment is to insulate wirings in different layers of the laminate, and serves as a wiring support. As an insulating layer, what is used for a general wiring board can be used. As such, a glass fiber as a reinforcing substrate is impregnated with a resin composition (resin varnish), and semi-cured B Examples thereof include a prepreg in a stage state and a resin film having no reinforcing base material such as glass fiber. As the resin composition, a thermosetting resin having good heat resistance and chemical resistance is used as a base, and resin such as phenol resin, epoxy resin, polyimide resin, unsaturated polyester resin, polyphenylene oxide resin, fluororesin, etc. 1 type or 2 types or more are mixed and used.

  The conductor layer in this embodiment is for forming a wiring for forming an electrical connection by circuit processing such as etching, and is formed by metal foil or metal foil and plating. The conductor layer is provided on the insulating layer by, for example, stacking and integrating a metal foil with a prepreg or an adhesive cheat serving as an insulating layer and then stacking and integrating them by hot pressing or the like. Furthermore, it is provided on the insulating layer by forming a plating on the metal foil. As the metal foil, a copper foil, a nickel foil, an aluminum foil or the like can be used, but a copper foil is usually used from the viewpoints of conductivity, workability, versatility and the like. As plating, filled plating, which is generally used for interlayer connection of a wiring board, can be used. Filled plating is plating formed using an electrolytic filled plating solution. An electrolytic filled plating solution is generally a plating inhibitor that suppresses plating growth in a copper sulfate plating bath, and plating acceleration that promotes plating growth. It is what added the agent.

  The interlayer connection in this embodiment is for forming an electrical connection between the upper and lower wirings of the insulating layer. For example, by forming an interlayer connection hole that penetrates the insulating layer from one conductor layer to the other conductor layer by using laser processing, drilling, punching processing, etc., and then performing filling plating. Can do.

  As shown in FIGS. 2 and 3, in this embodiment, the interlayer connection 7 includes the interlayer connection hole 2 and the plating 8 filled in the interlayer connection hole 2, and is a discontinuous dot-like line shape. Are arranged side by side. The discontinuous dot shape means that the interlayer connection 7 has an independent shape in a plan view such as a circle, an ellipse, and a polygon formed by using laser processing, drilling, punching, etc. It does not include elongated slits that are more than 5 times longer than the width. In addition, as shown in FIG. 3, when the discontinuous dot-like interlayer connections 7 are connected by a line, the line is arranged as a single straight line or curve as a whole.

  According to the laminate for a wiring board of the present embodiment, since the interlayer connection is filled with plating, the rigidity of the laminate can be ensured. Moreover, since it is a discontinuous dot shape, even if it arrange | positions linearly, since an insulating layer and the conductor layer of the both surfaces exist between discontinuous dots, a laminated body deform | transforms greatly. There is no. In addition, even if it is placed in a closed shape such as a polygon, circle, or lattice, the closed area does not fall out of the laminate, so the rigid structure with a large amount of free copper (structure for obtaining rigidity) Is obtained. Therefore, by having a rigid structure with a high degree of freedom of arrangement and shape and physically suppressing the shrinkage of the wiring board, there is little deformation due to the shrinkage that occurs in the laminating process, and high alignment accuracy is possible.

(Modification)
As shown in FIG. 1, in the laminate 1 for a wiring board according to the present embodiment, a plurality of product regions 3 that are products, and a boundary region 9 that is disposed so as to surround each of the plurality of product regions 3, An outer frame region 15 disposed so as to surround the plurality of product regions 3, and the interlayer connection 7 is disposed in a boundary region 9 surrounding each of the plurality of product regions 3, and is viewed in plan view Are preferably arranged in a grid pattern.

  The product area refers to an area that becomes a product as a wiring board. In the present embodiment, a plurality of product areas to be products are arranged in the work size when working in the manufacturing process. The boundary area refers to an area between product areas, and is arranged surrounding each of a plurality of product areas. The outer frame area refers to an outer area surrounding the entire area where a plurality of product areas are arranged, that is, an end area of the work size.

  According to this, since the product region is surrounded by the rigid interlayer connection, the deformation of the individual product regions is suppressed, and furthermore, since the product regions are arranged in a lattice shape, the rigidity of the entire laminate is improved.

  In the laminate for a wiring board of the present embodiment, as shown in FIG. 3, the interlayer connection 7 is arranged in discontinuous dots and arranged in multiple lines, and the layers arranged in multiple lines are arranged. It is preferable that the positions of the connections 7 be arranged so as to have a shift in the direction 16 arranged in a line between the interlayer connections 7 adjacent to each other in the direction perpendicular to the direction 16 arranged in a line.

  Disposing discontinuous dots and arranging them in multiple lines means that a straight line or a curved line when discontinuous dots are connected by a line becomes a multiple line (a plurality of lines).

  According to this, since the interlayer connection is arranged in multiple lines, the region having rigidity is further reinforced. Further, since the adjacent interlayer connections have a shift in the direction in which they are linearly arranged, the insulating layer having low rigidity between the dots of the interlayer connection is reinforced by the adjacent interlayer connection. Therefore, the deformation of the individual product areas is further suppressed, and the rigidity of the entire laminate is improved.

  In the laminate for a wiring board of the present embodiment, the interlayer connection from one conductor layer through the insulating layer to the other conductor layer is preferably a non-through hole. According to this, since the interlayer connection is non-penetrating, for example, in the coreless method, even if one of the laminated plates is arranged on the support substrate, an interlayer connecting hole is formed from one of the laminated plates. Plating can be filled from the opening of the interlayer connection hole. Moreover, since the interlayer connection holes can be formed by laser processing, workability is good.

  In the laminated body for a wiring board according to the present embodiment, the diameter of the laser via is preferably 40 μm to 200 μm. According to this, since the plating can be filled in the interlayer connection hole by the filled plating using the electrolytic filled plating solution, the rigidity of the interlayer connection is improved.

  In the laminated body for a wiring board according to the present embodiment, the distance between the inner walls of the laser vias (the thickness of the inner wall between adjacent laser vias) is 1 to 50 μm in the direction arranged in the form of discontinuous dots. Preferably there is. According to this, since adjacent laser vias are not connected to each other, even in the case of a closed shape such as a lattice shape, the inside of the closed shape does not fall off, so a rigid structure of a closed shape such as a lattice shape is formed. it can. In addition, since the space between the inner walls is 50 μm or less, the plating having rigidity is arranged at a relatively close interval, so that the rigidity as a whole can be ensured.

(Wiring board)
As shown in FIG. 2, the wiring board 11 can be formed by using the wiring board laminate 1 of the present embodiment. According to this, the deformation of the product region 3 is suppressed, and the rigidity of the laminated board 1 that is the material of the wiring board 11 is improved, so that the handleability is good and the deformation and the dimensional change in the manufacturing process can be suppressed. Further, for example, in the coreless method, deformation and dimensional change before and after separation from the support substrate can be suppressed.

  The wiring board of this embodiment may have a multilayer structure in which an insulating layer, a wiring, and an interlayer connection are further arranged on the wiring. In this case, since the interlayer connection filled with plating is formed in multiple in the thickness direction of the wiring board, the rigidity can be further increased, and deformation and dimensional change can be suppressed.

(Method for manufacturing a wiring board)
As a method for manufacturing a wiring board according to the present embodiment, as shown in FIG. The step (a) for forming the discontinuous dot-like interlayer connection holes 2 in a line and the step of filling the formed interlayer connection holes 2 with plating 8 and forming the plating 8 on the metal foil 4 ( and b) and a step (c) of forming the wiring 12 by processing the metal foil 4 and the plating 8 on the metal foil 4 by an etching process.

  According to this, since the interlayer connection is filled with plating, the rigidity of the wiring board can be ensured. Moreover, since it is a discontinuous dot shape, even if it arrange | positions at linear form, a wiring board does not deform | transform large. In addition, even when arranged in a closed shape such as a lattice shape, the closed region does not fall off, so that a rigid structure with a high degree of freedom in arrangement can be obtained. Therefore, by having a rigid structure with a high degree of freedom of arrangement and shape and physically suppressing the shrinkage of the wiring board, there is little deformation due to the shrinkage that occurs in the laminating process, and high alignment accuracy is possible.

  EXAMPLES Hereinafter, although the suitable Example of this invention is described, this invention is not limited to a following example.

  MCL-E-679FG (Hitachi Chemical Co., Ltd.), a prepreg made of glass cloth impregnated with insulating resin, laminated and integrated with copper foil, with a plate thickness of 0.10 mm, front and back copper foil thickness of 5 μm, and size of 500 mm × 400 mm (Manufactured by company, product name, “MCL” is a registered trademark)). This substrate is a so-called FR-4 (Frame returnant-4) material. Next, a roughening process was performed on the copper foil surface.

  Next, as shown in step (a) of FIG. 2, a laser via 2 that is non-penetrating in the depth direction is formed by laser processing from the roughened surface side using Cu direct laser processing. For the laser processing, a carbon dioxide laser processing machine LC-2K212 / 2C (manufactured by Hitachi Via Mechanics Co., Ltd., trade name) was used. The laser beam diameter was selected to be 80 μm, the insulating layer 6 was set to a laser condition for processing a depth of 30 to 45 μm, and the number of laser shots was 3 shots. The pitch between vias was 160 μm. At the same time, the laser via 2 in the product area (not shown) was simultaneously processed with the same processing machine.

  Next, as shown in step (b) of FIG. 2, a conductive film (underlying copper plating) is formed on the inner wall surface of the laser via 2 by electroless copper plating, and further, filled plating 8 is filled in the laser via 2. . Specifically, a desmear treatment in the through-hole 3 is performed using an aqueous sodium permanganate solution having a temperature of 80 ± 5 ° C. and a concentration of 55 ± 10 g / L, and then 0.4 to 0 by electroless copper plating. .8 μm thick conductive film (underlying plating) is formed, and then electrolytic field plating VF-5 (trade name, manufactured by Ebara Eugelite Co., Ltd.) is used. The plating 8 was filled in the laser via 2 to 25 μm. Next, as shown in step (c) of FIG. 2, the wiring 12 is formed by processing the filled plating 8 and the copper foil 4 on the front and back surfaces of the laminate 1 by a subtractive method, thereby forming the wiring substrate 11. did.

(Comparative example)
As a comparative example, a wiring board 11 was prepared in the same manner as in the example except that the laser via was processed only in the product region and the laser via was not processed in the boundary region.

(Evaluation)
As a result of measuring the deformation and shrinkage amount of the wiring boards of the example and the comparative example, the shrinkage amount of the comparative example varied from 10 μm to 80 μm, but in the example, it was possible to keep the variation from 10 μm to 30 μm. .

1. Laminate 2. 2. Laser via or interlayer connection hole Product area4. 4. (one) copper foil or (one) metal foil 5. (other) copper foil or (other) metal foil or (other) conductor layer Insulating layer 7. Filled via or interlayer connection8. 8. Filled plating or plating Boundary region 10. Outer frame area 11. Wiring board 12. Wiring 13. (One) conductor layer 15. Outer frame region 16. Direction arranged in a line

Claims (7)

An insulating layer, a conductor layer disposed on the front and back surfaces of the insulating layer, and an interlayer connection from the one conductor layer through the insulating layer to the other conductor layer,
The interlayer connection includes an interlayer connection hole and a plating filled in the interlayer connection hole, and is arranged in a line with discontinuous dots ,
A plurality of product areas to be products, a boundary area arranged to surround each of the plurality of product areas, and an outer frame area arranged to surround the plurality of product areas,
A laminate for a wiring board in which the interlayer connection is arranged in a boundary region surrounding each of the plurality of product regions and arranged in a lattice shape in a plan view . In claim 1 , the interlayer connection is arranged in a discontinuous dot shape in a multi-line shape,
The positions of the inter-layer connections arranged side by side in the multiple lines are arranged so that the inter-layer connections adjacent to each other in the direction perpendicular to the direction arranged in a line have a deviation in the direction arranged in the line. A laminate for wiring boards. According to claim 1 or 2, through the insulating layer from the conductor layer of the one interlayer connection leading to the other conductor layer, laminate wiring board is a non-through hole. In any one of claims 1 to 3, laminate wiring board diameter of laser via is 40Myuemu～200myuemu. The laminate for a wiring board according to any one of claims 1 to 4 , wherein the distance between the inner walls of the laser vias in the direction arranged in the form of discontinuous dots is linear. The wiring board manufactured using the laminated body in any one of Claim 1 to 3 . It is a manufacturing method of the wiring board of Claim 6 ,
In the step (a) of forming discontinuous dot-like interlayer connection holes in a line on the surface of a double-sided metal foil-clad laminate in which metal foil is disposed on the front and back surfaces of the insulating layer, and in the formed interlayer connection holes A step (b) of filling the plating and forming the plating on the metal foil; and a step (c) of forming a wiring by processing the metal foil and the plating on the metal foil by etching. Yes, and
The wiring board has a plurality of product regions that are products, a boundary region that is disposed so as to surround each of the plurality of product regions, and an outer frame region that is disposed so as to surround the plurality of product regions. And
A method of manufacturing a wiring board, wherein the interlayer connection is arranged in a boundary region surrounding each of the plurality of product regions and arranged in a lattice shape in plan view .

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