JP2005093904A - Multilayer wiring board and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable suppression of flowing of an adhesive layer during lamination of multiple layers, prevention of an interlayer shift, acquisition of a high lamination accuracy, and acquisition of an electric characteristic of stable interlayer conduction. <P>SOLUTION: In one multilayer board 10, a through hole 16 passed through an insulating substrate (insulating resin layer 11 plus adhesive layer 13) is made at a position away from a wiring pattern 12; a resin composition 17 is filled in the through hole; and the resin composition 17 forms a positioning projection 18 extruded outwardly from the adhesive layer 13 of the insulating substrate. In the other multilayer board 20, a circular-ring-shaped projection 23 made of a conductive layer for receiving the positioning projection 18 at a position away from a wiring pattern 22 is formed. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multilayer wiring board (multilayer printed wiring board) and a manufacturing method thereof, and in particular, a multilayer wiring board for connecting two or more layers of wiring patterns used as a wiring board for mounting electronic components, a package board, and the like. And a manufacturing method thereof.

  As electronic devices become lighter, thinner and smaller, semiconductor chips and components are downsized, and terminals have a narrow pitch, wiring boards and package substrates on which electronic components are mounted are also being reduced in mounting area and wiring. At the same time, information-related equipment is required to shorten the wiring distance between components in response to the wider bandwidth of signal frequencies, and multilayered printed circuit boards are essential to achieve high density and high performance. Technology.

  Multi-layer wiring boards can obtain interlayer conduction with conductive paste filled in via holes formed in an insulating substrate (for example, Patent Documents 1 and 2), and the insulating substrate can be made of a flexible material such as polyimide. There exists what was comprised with the resin film (for example, patent document 2).

  With the increase in the density of multilayer wiring boards, miniaturization of wiring pattern portions formed on a wiring board has progressed, and the number of stacked layers tends to increase. In the multilayer wiring board, the lamination accuracy of the wiring board affects the performance of the multilayer wiring board. Therefore, as the number of lamination increases, development of a lamination method with high lamination accuracy is desired.

  As a technique for alignment of multilayer laminations of wiring boards, a pin lamination method (for example, non-patent literature) in which alignment holes are formed in all the wiring boards to be laminated and the holes are laminated through the laminated pins. 1), an alignment method using image processing, a method of combining these, and the like are known. Multi-layer lamination of wiring boards includes a technique of batch lamination using a heatable vacuum press apparatus or the like.

  In the conventional multilayer wiring board, each layer is aligned by various alignment methods prior to multilayer lamination. As shown in FIGS. 8A to 8C, a heatable vacuum press apparatus or the like is used. Adhesive layer 102 that adheres each layer, especially thermoplastic adhesive layer, softens and flows between the layers during multi-layer lamination (heat bonding) using, causing lateral displacement between the layers, resulting in no alignment effect and reduced lamination accuracy Occurs.

  8A shows a state before heat bonding, FIG. 8B shows a bonding state of heat bonding, and FIG. 8C shows a state of occurrence of lateral displacement. 8A to 8C, reference numerals 101 and 111 denote insulating base materials, reference numerals 103 and 113 denote wiring patterns made of copper foil or the like, and reference numeral 104 denotes an interlayer conductive portion made of conductive paste or the like.

  The pin lamination method provides some degree of lateral slip prevention effect, but the presence of clearance between the pin lamination jig and the guide hole of the base material for the multilayer substrate enables high alignment accuracy that is greater than the clearance. This is not possible and there is a limit to improving the stacking accuracy.

  As a conventional multilayer wiring board, as shown in FIGS. 9A and 9B, a connection projection 133A is formed on a portion (land portion) of the wiring pattern 133 corresponding to the position of the interlayer conductive portion 124 of the adjacent layer. There is one in which the connection protrusion 133A enters the interlayer conductive portion 124, that is, the conductive paste 124B of the via hole 124A by providing and laminating pressure (for example, Patent Document 3).

  9A and 9B, reference numerals 121 and 131 denote insulating substrates, 122 denotes an adhesive layer, and 123 and 133 denote wiring patterns made of copper foil or the like.

In this multilayer wiring board, since the connection protrusion 133A enters the conductive paste 124B of the via hole 124A, the reliability of interlayer conduction is improved, and the effect of suppressing the positional displacement (lateral deviation) between the layers can be expected.
JP-A-6-302957 Japanese Patent Laid-Open No. 9-82835 JP 2000-294931 A Kiyoshi Takagi “Build-up multilayer printed circuit board technology” published by Nikkan Kogyo Shimbun, June 15, 2001, first edition, 2nd edition, pages 176-177

  However, as shown in FIG. 9B, the paste flows out of the via hole 124A by the volume of the connection protrusion 133A entering the conductive paste 124B of the via hole 124A. The paste outflow portion 124C decreases the reliability of electrical connection and causes a decrease in electrical insulation between circuits due to migration. In addition, a process such as plating or half-etching is required to form the connection protrusion 133A, and the manufacturing cost is high.

  The problem to be solved by the present invention is to suppress the flow of the adhesive layer at the time of multilayer lamination, prevent interlayer displacement, obtain high lamination accuracy, and obtain stable electrical characteristics of interlayer conduction.

  In the multilayer wiring board according to the present invention, a conductive layer forming a wiring pattern is provided on one surface of an insulating substrate, and a via hole penetrating the insulating substrate is formed at a position continuous with the wiring pattern. A wiring pattern is formed on one surface of the insulating base material and at least one base material for the multilayer substrate, which is in a conductive relationship with the wiring pattern by the conductive resin composition filled in the via hole and obtains interlayer conduction. In the multilayer wiring board laminated with the multilayer substrate substrate provided with the conductive layer, a hole penetrating the insulating substrate is formed at a position away from the wiring pattern of one multilayer substrate substrate, The hole is filled with a resin composition, and the resin composition has an alignment protrusion protruding outward from the other surface of the insulating substrate, and the wiring pattern of the other multilayer substrate substrate The further away Annular projection for receiving the alignment protrusions are formed by a conductive layer.

  In the multilayer wiring board according to the present invention, the resin composition filled in the hole and including the alignment protrusion is the same resin composition as the conductive resin composition filled in the via hole, or an inorganic material. Or a resin composition having a glass transition temperature lower than that of the conductive resin composition filled in the via hole.

  In addition, the insulating substrate of the multilayer wiring board according to the present invention has a single-layer structure in which the insulating layer also serves as an adhesive layer for adhesion between the insulating layers, or an adhesive layer for adhesion between the insulating layers and the insulating layer. The two-layer structure can be used.

  In the method for manufacturing a multilayer wiring board according to the present invention, a conductive layer forming a wiring pattern is provided on one surface of an insulating substrate, and a via hole penetrating the insulating substrate is formed at a position continuous with the wiring pattern. And at least one multi-layer board substrate that has a conductive relationship with the wiring pattern and obtains interlayer conduction by the conductive resin composition filled in the via hole, and wiring on one surface of the insulating substrate In the manufacturing method of a multilayer wiring board laminated with a multilayer substrate base material provided with a conductive layer forming a pattern, the insulating base material is penetrated at a position away from the wiring pattern of one multilayer substrate base material A step of forming a hole to be formed, a step of filling the hole with a resin composition, and a step of forming an alignment protrusion protruding outward from the other surface of the insulating base by the resin composition; Multi-layer substrate base Forming an annular protrusion for receiving the alignment protrusion by the conductive layer at a position away from the wiring pattern, laminating a plurality of multilayer substrate substrates, and the alignment protrusion and the A step of fitting the annular protrusions, and a step of adhesively bonding a plurality of laminated base materials for a multilayer substrate.

  The method for producing a multilayer wiring board according to the present invention preferably includes a step of temporarily curing or curing the alignment protrusions prior to the step of laminating a plurality of multilayer substrate substrates.

  In the multilayer wiring board according to the present invention, the alignment protrusion protruding outward from the other surface of the insulating base material is fitted into the annular protrusion of the multilayer substrate base material to be joined (adjacent layer). The effect of preventing lateral deviation can be obtained. Since the alignment protrusion and the annular protrusion are provided at a position away from the wiring pattern and electrically isolated from the wiring pattern, the arrangement and size of the alignment protrusion and the annular protrusion are limited. It is possible to freely set an installation site and a size that can effectively prevent a lateral deviation without receiving any damage.

  1 to 3 show one embodiment of a multilayer wiring board according to the present invention.

  In this embodiment, the multilayer wiring board is a two-layer wiring board composed of an upper multilayer substrate 10 and a lower multilayer substrate 20.

  The multilayer substrate 10 includes an insulating resin layer 11 that forms an insulating substrate, and a wiring pattern portion (conductive layer) 12 made of copper foil or the like on one surface of the insulating resin layer 11. An adhesive layer 13 for interlayer adhesion is formed on the other surface.

  In the FPC (flexible printed circuit board), the insulating resin layer 11 is made of a flexible resin film such as a polyimide film made of wholly aromatic polyimide (API) or a polyester film.

  The three-layer structure of the insulating resin layer 11, the wiring pattern portion 12 and the adhesive layer 13 starts with a general-purpose single-sided copper substrate with a copper foil (single-sided copper-clad laminate) and is opposite to the copper foil. It can be configured by attaching a polyimide adhesive as the adhesive layer 13 to the surface. The adhesive layer 13 made of a polyimide-based adhesive can be formed by attaching a thermoplastic polyimide (TPI) or a film obtained by imparting a thermosetting function to a thermoplastic polyimide.

  The insulating resin layer 11 and the adhesive layer 13 are formed with via holes 14 penetrating them. The via hole 14 is filled with a conductive paste 15 for obtaining interlayer conduction.

  The conductive paste 15 is a paste obtained by mixing a metal powder (conductive filler) having a conductive function such as silver or copper in a thermosetting resin binder such as an epoxy resin with a viscous medium containing a solvent. The conductive resin composition. The conductive paste 15 is filled in the via hole 14 from the side of the adhesive layer 13 by squeezing or the like used in the screen printing method.

  The multilayer substrate base material 20 has an insulating resin layer 21 that forms an insulating base material, and a wiring pattern portion (conductive layer) 22 made of copper foil or the like on one surface of the insulating resin layer 21.

  The insulating resin layer 21 is composed of a flexible resin film such as a polyimide film made of wholly aromatic polyimide (API) or a polyester film, like the insulating resin layer 11 of the multilayer substrate 10.

  A through-hole 16 that penetrates the insulating resin layer 11 and the adhesive layer 12 is formed in the multilayer substrate base material 10 at a position away from the wiring pattern portion 12. The through-hole 16 is filled with a resin composition 17, and the resin composition 17 has a columnar alignment protrusion 18 (see FIG. 2) protruding outward from the adhesive layer 12.

  The resin composition 17 is the same resin composition as the conductive resin composition (conductive paste 15) filled in the via hole 14, or a filler mixed with a filler made of an inorganic material such as silica, or a via hole. 14 can be comprised with thermosetting resin compositions, such as an epoxy resin, whose glass transition temperature is lower than the conductive paste 15 with which 14 was filled.

  When the resin composition 17 is the same resin composition as the conductive paste 15 filled in the via hole 14, the filling of the conductive paste 15 in the via hole 14 and the resin composition 17 in the through hole 16 are performed. The alignment protrusion 18 can be formed in the same process as filling without increasing the number of processes.

  When the resin composition 17 is composed of a thermosetting resin composition such as an epoxy resin having a glass transition temperature lower than that of the conductive paste 15 filled in the via hole 14, a temporary curing step of the conductive paste 15 is performed. Thus, the resin composition 17 can be completely cured, and high hardness and mechanical strength can be obtained.

  Further, when the resin composition 17 is mixed with a filler made of an inorganic material such as silica, the mechanical strength including the compression resistance of the alignment projection 18 is improved.

  In the multilayer substrate 20, an annular protrusion 23 that receives the alignment protrusion 18 is formed at the position away from the wiring pattern 22 by the same conductive layer as the conductive layer constituting the wiring pattern 22. (See FIG. 3).

  The inner diameter b of the annular protrusion 23 is set to a dimension that is equal to or slightly smaller than the outer diameter a of the alignment projection 18.

  The resin composition 17 including the alignment projection 18 is temporarily cured or cured before the step of laminating the multilayer substrate base materials 10 and 20, and is temporarily cured or cured during the lamination step. 18 is fitted to the annular protrusion 23.

  By this fitting, interlayer displacement can be prevented, high lamination accuracy can be obtained, and stable electrical characteristics of interlayer conduction can be obtained.

  Further, the alignment projection 18 and the annular protrusion 23 are provided at positions away from the wiring pattern portions 12 and 22, respectively, and are electrically isolated from these wiring patterns. Arrangement and size of the protrusion 18 and the annular protrusion 23 are not restricted, and an installation site and size that can effectively prevent lateral deviation can be set freely.

  As shown in FIG. 4, the alignment fitting portion 30 of the alignment protrusion 18 and the annular protrusion 23 is around the wiring board product portion A in the manufacturing process, and is finally cut off. Is provided in a manufacturing allowance part (margin part) B or, as shown in FIG. 5, in the wiring board product part A, it is provided at an appropriate position apart from the wiring pattern parts 12 and 22.

  Next, the manufacturing process of the multilayer wiring board according to the present invention will be described with reference to FIGS.

  As shown in FIG. 6A, a general-purpose single-sided copper-clad polyimide substrate (single-sided conductor-clad laminate) 40 is prepared as a starting material. A single-sided copper-clad laminate (CCL) having a copper foil 41 as a conductive layer only on one side of a single-sided copper-clad polyimide substrate 40 and an insulating resin layer 11 made of a polyimide film.

  First, as shown in FIG. 6B, the copper foil 41 of the single-sided copper-clad polyimide substrate 40 is etched to form a wiring pattern portion (copper circuit) 12.

  Next, as shown in FIG. 5C, thermoplastic polyimide is bonded to the surface of the insulating resin layer 11 opposite to the wiring pattern portion 12 by a hot press to form an adhesive layer 13. A peelable cover layer 43 made of PET film or the like is bonded on top.

  Next, as shown in FIG. 5 (d), a laser is irradiated from the cover layer 43 side to an arbitrary position where interlayer connection is desired, and penetrates the insulating base material 31, the adhesive layer 33, and the cover layer 43. The via hole 14 is formed, and the through hole 16 penetrating the insulating substrate 31, the adhesive layer 33, and the cover layer 43 is formed at a position that is electrically separated from the wiring pattern portion 12 and independent of the wiring pattern portion 12. I can make it.

  In this embodiment, a small hole 14 </ b> A for venting air is formed in the wiring pattern portion 12. The reason why the copper foil 41A is left in the portion of the through-hole 16 is to prevent the conductive paste from dropping off when the conductive paste described later is filled, and is not essential. A small hole 16A for venting air is also formed in the copper foil 41A.

  Next, as shown in FIGS. 5 (e) and 5 (f), the conductive paste 15 is filled into the via holes 14 and the through holes 16 from the cover layer 43 side using the squeegee plate 50. Note that the conductive paste 15 filled in the through holes 16 is labeled as a resin composition 17 for convenience of illustration.

  Next, as shown in FIG. 5G, the conductive paste 15 and the resin composition 17 are temporarily cured, and then the cover layer 43 is peeled and removed. As a result, an interlayer conduction protrusion 15A protruding outward from the adhesive layer 13 is formed at the via hole 14 side on the adhesive layer 13 side, and similarly, from the adhesive layer 13 at the through hole 16 site. An alignment projection 18 projecting outward is formed. Thereby, the upper layer base material 10 for multilayer substrates is completed.

  Further, as shown in FIG. 6 (h), a copper foil is etched on one surface of the insulating resin layer 21 using a single-sided copper-clad polyimide substrate similar to the single-sided copper-clad polyimide substrate 40 as a starting material. Thus, the wiring pattern portion 22 is formed, and an annular protrusion 23 made of copper foil is simultaneously formed at a position that is electrically separated from the wiring pattern portion 22 and independent of the wiring pattern portion 22. Thereby, the base material 20 for the lower multilayer board is completed.

  Next, as shown in FIG. 6 (i), the upper multilayer substrate base material 10 and the lower multilayer substrate base material 20 are laminated, and the multilayer substrate base materials 10 and 20 are obtained by image recognition or the like. Then, as shown in FIG. 6 (j), the alignment protrusions 18 of the upper multilayer substrate base material 10 are formed into annular projections of the lower multilayer substrate base material 20 as shown in FIG. Fit into part 23. Note that the interlayer conduction protrusion 15A abuts against the wiring pattern portion 22 and reduces the contact electrical resistance of the interlayer conduction.

  In this fitted state, heating and pressurization are performed by a vacuum press machine, and a multilayer wiring board bonded by the adhesive layer 13 is completed.

  At the time of this curing, since the alignment projection 18 of the upper multilayer substrate 10 and the annular projection 23 of the lower multilayer substrate 20 are fitted together, even if the adhesive layer 13 is softened , No lateral shift occurs.

  Thereby, without using a special instrument or device for preventing displacement, interlayer displacement can be prevented, high lamination accuracy can be obtained, and stable electrical characteristics of interlayer conduction can be obtained.

  In addition, since both the alignment protrusion 18 and the annular protrusion 23 are formed in the same process as the conventional one, there is no additional process, and the time required for manufacturing is long only to prevent misalignment. Never become.

  In the multilayer wiring board according to the present invention, the insulating substrate is not limited to the one having the two-layer structure of the insulating resin layer 11 and the adhesive layer 13 that performs interlayer adhesion as described above. As described above, the present invention can be similarly applied to a one-layer structure in which an insulating base is constituted by an insulating layer 51 having adhesiveness, and the insulating layer 51 also serves as an adhesive layer that performs interlayer adhesion. 7, parts corresponding to those in FIG. 1 are denoted by the same reference numerals as those in FIG. 1, and description thereof is omitted.

  Examples of the insulating layer 51 having adhesiveness include thermoplastic polyimide (TPI), a thermoplastic polyimide provided with a thermosetting function, and a liquid crystal polymer.

It is sectional drawing which shows one Embodiment of the multilayer wiring board by this invention. It is an expanded sectional view of the important section of the multilayer wiring board by one embodiment. It is an expansion perspective view of the principal part of the multilayer wiring board by one embodiment. 1 is an overall plan view showing one embodiment of a multilayer wiring board according to the present invention. It is a whole top view which shows other embodiment of the multilayer wiring board by this invention. (A)-(j) is process drawing which shows the manufacturing process of one Embodiment of the multilayer wiring board by this invention. It is sectional drawing which shows other embodiment of the multilayer wiring board by this invention. (A)-(c) is sectional drawing which shows the prior art example of a multilayer wiring board. (A), (b) is sectional drawing which shows the prior art example of a multilayer wiring board.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Base material 11 for multilayer substrates Insulating resin layer 12 Wiring pattern part 13 Adhesive layer 14 Via hole 15 Conductive paste 16 Through-hole 17 Resin composition 18 Positioning projection 20 Multilayer substrate base material 21 Insulating resin layer 22 Wiring pattern Part 30 alignment fitting part 40 single-sided copper-clad polyimide base material 51 insulating layer

Claims (7)

A conductive layer forming a wiring pattern is provided on one surface of the insulating substrate, and a via hole penetrating the insulating substrate is formed at a position continuous with the wiring pattern, and the via hole is filled with the conductive material. A multilayer substrate provided with at least one base material for a multilayer substrate in a conductive relationship with the wiring pattern by the resin composition and obtaining interlayer conduction, and a conductive layer forming the wiring pattern on one surface of the insulating base material In a multilayer wiring board laminated with a base material for use,
One multilayer substrate base material has a hole penetrating the insulating base material at a position away from the wiring pattern, and the hole is filled with a resin composition, and the resin composition is the insulating base material. A projection for alignment projecting outward from the other surface of the
A multilayer wiring board in which an annular protrusion that receives the alignment protrusion by the conductive layer is formed on the other multilayer substrate base material at a position away from the wiring pattern.   The multilayer wiring board according to claim 1, wherein the resin composition filled in the hole and including the alignment protrusion is the same resin composition as the conductive resin composition filled in the via hole.   The multilayer wiring board according to claim 1, wherein a filler made of an inorganic material is mixed in the resin composition filled in the holes and including the alignment protrusions.   4. The multilayer according to claim 1, wherein the resin composition filled in the hole and including the alignment protrusion is a resin composition having a glass transition temperature lower than that of the conductive resin composition filled in the via hole. Wiring board.   The insulating base material has a single-layer structure that also serves as an adhesive layer that has adhesiveness and an insulating layer performs interlayer adhesion, or has a two-layer structure that includes an insulating layer and an adhesive layer that performs interlayer adhesion. Item 5. The multilayer wiring board according to any one of Items 1 to 4. A conductive layer forming a wiring pattern is provided on one surface of the insulating substrate, and a via hole penetrating the insulating substrate is formed at a position continuous with the wiring pattern, and the via hole is filled with the conductive material. A multilayer substrate provided with at least one base material for a multilayer substrate in a conductive relationship with the wiring pattern by the resin composition and obtaining interlayer conduction, and a conductive layer forming the wiring pattern on one surface of the insulating base material In the manufacturing method of the multilayer wiring board laminated with the base material for use,
Forming a hole penetrating the insulating base material at a position away from the wiring pattern of the base material for one multilayer substrate;
Filling the hole with a resin composition, and forming the alignment protrusion protruding outward from the other surface of the insulating base by the resin composition;
Forming an annular protrusion for receiving the alignment protrusion by the conductive layer at a position away from the wiring pattern of the other multilayer substrate substrate;
A step of laminating a plurality of base materials for a multilayer substrate, and fitting the positioning protrusions and the annular protrusions;
Adhering and bonding a plurality of laminated base materials for a multilayer substrate;
The manufacturing method of the multilayer wiring board which has this.   The method for manufacturing a multilayer wiring board according to claim 6, further comprising a step of temporarily curing or curing the alignment protrusions before the step of laminating a plurality of multilayer substrate substrates.

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