JP2007173658A - Method for manufacturing wiring board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for efficiently manufacturing a thin wiring board with high mounting density. <P>SOLUTION: The manufacturing method for the wiring board 100 includes a process of alternately laminating insulating layers 11 to 15 and wiring conductors 21 to 24 on the main surface of a support board 1, to form a core lamination 10 composed of the insulating layers 11 to 15 and the wiring conductors 21 to 24; a process of peeling the core lamination 10 off the support board 1; and a process of laminating respective wiring conductors 25 to 28 and insulating layers 16 to 19 alternately on both surfaces of the core lamination 10. In easily peeling the core lamination 10 off the support board 1 without damaging the core lamination 10, the process of forming the core lamination 10 includes a process of interposing a given adhesive between the support board 1 and the core lamination 10, and, preferably, the process of peeling the core lamination 10 of the support board 1 is carried out after the adhesion of the adhesive is lessened or eliminated. <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, there is a build-up wiring board as a high-density multilayer wiring board used for mounting electronic components such as semiconductor elements. FIG. 5 is a schematic cross-sectional view showing a general build-up wiring board. As shown in the figure, the build-up wiring board 80 includes a core board 83 having wiring conductors 82 made of copper foil on both surfaces of a glass-resin plate 81 having a thickness of about 0.2 to 2.0 mm, and the core. Insulating layers 84 made of a resin having a thickness of about 10 to 100 μm and wiring conductors 85 made of a plating film are alternately laminated on both surfaces of the substrate 83. Such a build-up wiring board 80 is manufactured by, for example, the following method.

  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. This double-sided copper-clad plate is drilled with through-holes that penetrate the upper and lower surfaces, and a plating film is deposited on the inner wall of the through-hole, and the copper foils on the upper and lower surfaces are electrically connected by the plating film in the through-holes. To do. Then, after filling the through hole with resin, the upper and lower copper foils are etched into a predetermined pattern to obtain a core substrate 83 having wiring conductors 82 made of copper foil on both surfaces of the glass-resin plate 81.

  Next, a resin film in which an inorganic insulating filler is dispersed in a thermosetting resin such as an epoxy resin or a bismaleimide triazine resin is attached to the upper and lower surfaces of the core substrate 83, and the thermosetting resin in the resin film is attached. The insulating layer 84 is formed by heat curing. A via hole is drilled in the insulating layer 84 by laser processing, and a wiring conductor 85 made of a plating film is simultaneously formed on the surface of the insulating layer 84 including the inside of the via hole by a semi-additive method. Then, by repeating the formation of the next insulating layer 84 and the wiring conductor 85 a plurality of times, a core substrate 83 having wiring conductors 82 made of copper foil on both surfaces of the glass-resin plate 81 and both surfaces of the core substrate 83 are formed. A build-up wiring board 80 is produced in which insulating layers 84 made of resin and wiring conductors 85 made of a plating film are alternately laminated.

  However, although such a build-up wiring board 80 enables high-density wiring, the glass-resin plate 81 having a thickness of about 0.2 to 2.0 mm is used as the core board 83. There is a problem that it is difficult to reduce the overall thickness of the film.

  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 for manufacturing a multilayer substrate for a semiconductor device is described. 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, the wiring conductor and the insulating layer constituting the multilayer substrate for the semiconductor device are sequentially layered one by one from the semiconductor element mounting surface side to the external connection terminal mounting surface side on one surface side of the metal plate. Since it is necessary to stack the layers and finally the metal plate needs to be removed by etching, there is a problem to be solved that the manufacturing process is extremely complicated. Further, when the metal plate is removed, the substrate may be warped or wavy due to residual stress.
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.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have found a solution means having the following constitution and have completed the present invention.
(1) forming a core laminate comprising the insulating layer and the wiring conductor by alternately laminating insulating layers and wiring conductors on a main surface of the support substrate; and forming the core laminate from the support substrate. A method for manufacturing a wiring board, comprising: a step of peeling, and a step of alternately laminating wiring conductors and insulating layers on both upper and lower surfaces of the peeled core laminate.
(2) The method for manufacturing a wiring board according to (1), wherein a main surface of the support substrate is flat.
(3) The method for manufacturing a wiring board according to (1) or (2), wherein the wiring conductor is formed by a semi-additive method.
(4) The step of forming the core laminate includes a step of interposing a predetermined adhesive layer between the support substrate and the core laminate, and the step of peeling the core laminate from the support substrate includes the step of The method for manufacturing a wiring board according to any one of (1) to (3), which is a step of peeling the core laminate from the support substrate after reducing or eliminating the adhesive strength of the adhesive layer.
(5) The step of forming the core laminated body forms a core laminated body composed of the insulating layer and the wiring conductor by alternately laminating insulating layers and wiring conductors on the upper and lower surfaces of the support substrate. The manufacturing method of the wiring board in any one of said (1)-(4) which is a process to perform.

  According to (1), after forming a core laminate by alternately laminating insulating layers and wiring conductors on the main surface of the support substrate, on both upper and lower surfaces of the core laminate peeled from the support substrate, Since wiring conductors and insulating layers are alternately laminated, there is no problem that the entire thickness of the wiring board cannot be reduced by using a glass-resin plate, and a thin and high-density wiring board is provided. be able to. Moreover, when forming the wiring conductors on the upper and lower surfaces of the core laminate, the upper and lower wiring conductors can be processed at the same time, so that a thin and high-density wiring board can be efficiently manufactured and processed. It is possible to suppress the accompanying warpage and undulation, and as a result, it is possible to provide a wiring board having high flatness and excellent mountability.

  According to said (2), the flatness of the wiring board concerning this invention can be made higher. According to said (3), the wiring conductor concerning this invention can be formed easily and efficiently. According to said (4), it can peel easily from a support substrate, without damaging a core laminated body. According to said (5), a core laminated body can be formed efficiently.

  An example of a method for manufacturing a wiring board according to the present invention will be described in detail with reference to the drawings. 1 to 3 are schematic cross-sectional views for each process for explaining a method of manufacturing a wiring board according to the present invention. Among these drawings, FIGS. 1A to 1D are schematic cross-sectional views showing a process of forming a core laminate, and FIG. 2 is a schematic cross-sectional view showing a state in which the core laminate is peeled from a support substrate. FIGS. 3A to 3C are schematic cross-sectional views showing a process of alternately laminating wiring conductors and insulating layers on the upper and lower surfaces of the core laminate.

  First, as shown in FIG. 1A, a support substrate 1 having a flat main surface is prepared. The support substrate 1 functions as a temporary support for temporarily supporting the core laminate 10 described below on the main surface. For this reason, it is preferable that it consists of hard materials, such as glass, ceramics, hard resin, a metal. Moreover, although the support substrate 1 is comprised by the substantially rectangular flat plate whose thickness is about 0.2-2.0 mm and the length of one side is about 300-1000 mm, it is not limited to this.

  Next, as shown in FIG. 1B, the first insulating layer 11 is laminated on the main surface of the support substrate 1. Specifically, first, a resin film in which an inorganic insulating filler is dispersed in a thermosetting resin such as an epoxy resin or a bismaleimide triazine resin is attached to the main surface of the support substrate 1. The thickness of the resin film is preferably about 10 to 100 μm. Subsequently, the insulating layer 11 is laminated | stacked by thermosetting the thermosetting resin in the stuck resin film.

  Next, as shown in FIG. 1C, the first wiring conductor 21 is laminated on the surface of the first insulating layer 11. The first wiring conductor 21 is made of a plating film such as a copper plating film and is preferably formed by a semi-additive method. Since the semi-additive method is excellent in miniaturization, the wiring conductor according to the present invention can be formed easily and efficiently. Specifically, first, the surface of the first insulating layer 11 is roughened as necessary, and an electroless copper plating film is deposited on the surface with a thickness of about 0.1 to 2.0 μm.

  A plating resist layer having an opening corresponding to the wiring conductor 21 is formed on the surface of the electroless copper plating film. The plating resist layer is formed by adhering a photosensitive resin film on the electroless copper plating film, and adopting a photolithographic technique for the resin film to perform exposure / development treatment, thereby opening the opening. Formed to have.

  Then, after the electrolytic copper plating film is deposited with a thickness of about 5 to 30 μm on the electroless copper plating film exposed in the opening of the plating resist layer, the plating resist layer is peeled off. Finally, the electroless copper plating film and the exposed portion of the electrolytic copper plating film are entirely etched until the electroless copper plating film between the wiring conductors 21 disappears, whereby the wiring conductor 21 is formed. The thickness of the wiring conductor 21 is preferably about 5 to 30 μm.

  Next, as shown in FIG.1 (d), the 2nd insulating layer 12 and the 2nd wiring conductor 22 are laminated | stacked on the 1st insulating layer 11 and the 1st wiring conductor 21, and 3rd on it. The fourth insulating layer 13 and the third wiring conductor 23 are stacked, the fourth insulating layer 14 and the fourth wiring conductor 24 are stacked thereon, and the fifth insulating layer 15 is further stacked thereon. Thereby, the core laminated body 10 formed by alternately laminating the insulating layers 11, 12, 13, 14, 15 and the wiring conductors 21, 22, 23, 24 is formed on the surface of the support substrate 1.

  The second to fifth insulating layers 12 to 15 are preferably made of the same material as that of the first insulating layer 11, and an insulating layer and a wiring having a resin film similar to that of the first insulating layer 11 as a lower layer. It is formed by sticking on a conductor and thermosetting it. At this time, via holes VH serving as paths for electrically connecting the lower wiring conductor and the upper wiring conductor are drilled in the second to fourth insulating layers 12 to 14 by laser processing, photolithography processing, or the like. Keep it. The second to fourth wiring conductors 22 to 24 are preferably made of the same plating film as the first wiring conductor 21 and are formed by the same semi-additive method as the first wiring conductor 21. preferable.

Here, the thickness of each insulating layer 12-15 can illustrate the same thickness as the thickness illustrated by the 1st insulating layer 11, and the thickness of each wiring conductor 22-24 is the 1st wiring conductor 21. The same thickness as illustrated can be illustrated. And it is preferable that the thickness of the core laminated body 10 is about 100-500 micrometers, and the thickness of each insulating layer 11-15 and each wiring conductor 21-24 is mentioned above so that the thickness of the core laminated body 10 may become this range. It is better to adjust within the range.
On the other hand, if the thickness of the core laminate 10 exceeds 500 μm, it is difficult to reduce the overall thickness of the wiring board, and if it is less than 100 μm, the strength of the core laminate 10 is not preferable.

  Next, as shown in FIG. 2, the core laminate 10 is peeled from the support substrate 1. The method of peeling the core laminate 10 from the support substrate 1 is not particularly limited, but in the present invention, it is preferable to interpose a specific adhesive layer between the support substrate 1 and the core laminate 10. . According to this, it can peel from the support substrate 1 easily, without damaging the core laminated body 10. FIG. Specifically, when the first insulating layer 11 is formed on the main surface of the support substrate 1, for example, by application of heat or irradiation of ultraviolet rays between the support substrate 1 and the first insulating layer 11. An adhesive layer (not shown) in which the adhesive strength is reduced or disappeared is interposed in advance, and after the core laminate 10 is completed, the adhesive layer is subjected to heat application or ultraviolet irradiation to reduce the adhesive strength of the adhesive layer or After the disappearance, the core laminate 10 is peeled off from the support substrate 1. Thereby, it can peel easily, without damaging the core laminated body 10. FIG.

  As the adhesive layer whose adhesive strength is reduced or disappeared by application of heat, for example, a thermally expandable microsphere in which a substance that easily expands by gasification by heating in an adhesive is encapsulated in an elastic shell. Examples thereof include blended adhesive resin materials. Here, examples of the pressure-sensitive adhesive include rubber-based pressure-sensitive adhesives, acrylic pressure-sensitive adhesives, vinyl alkyl ether-based pressure-sensitive adhesives, silicone-based pressure-sensitive adhesives, polyester-based pressure-sensitive adhesives, polyamide-based pressure-sensitive adhesives, urethane-based pressure-sensitive adhesives, and styrene-diene. Examples of the material that easily gasifies and expands by heating include isobutane, propane, pentane, etc., and the composition constituting the elastic shell includes, for example, chloride. Examples include vinylidene-acrylonitrile copolymer, polyvinyl alcohol, polyvinyl butyral, polymethyl methacrylate, polyacrylonitrile, polyvinylidene chloride, polysulfone and the like.

  In addition, as an adhesive layer whose adhesive strength is reduced or disappeared by irradiation with ultraviolet rays, an acrylic pressure-sensitive adhesive polymer (for example, 2-ethylhexyl acrylate and acrylic acid), an ultraviolet curable oligomer (for example, urethane acrylate oligomer), a photoinitiator Examples thereof include an adhesive resin material containing (for example, 1-hydroxycyclohexyl phenyl ketone). Although the thickness of the said adhesive layer is not specifically limited, Usually, it is about 5-30 micrometers.

  Wiring conductors and insulating layers are alternately laminated on the upper and lower surfaces of the core laminate 10 obtained as described above. As a result, there is no problem that the entire thickness of the wiring board cannot be reduced by using a glass-resin plate, and a thin and high-density wiring board can be efficiently manufactured, and warping and The occurrence of swell can be suppressed. On the other hand, when wiring conductors and insulating layers are alternately laminated on only one side of the core laminate 10, not only the efficiency is lowered, but also the wiring board may be warped or swelled.

  Specifically, first, as shown in FIG. 3A, via holes VH are formed in the first insulating layer 11 and the fifth insulating layer 15 located on the surface layer of the peeled core laminated body 10. Next, a fifth wiring conductor 25 is stacked on the first insulating layer 11, and a sixth wiring conductor 26 is stacked on the fifth insulating layer 15.

  The via holes VH in the insulating layers 11 and 15 are formed by the same laser processing, photolithography processing, or the like as in the case of the insulating layers 12 to 14. The wiring conductors 25 and 26 are preferably made of a plating film similar to that of the wiring conductors 21 to 24, and are preferably formed by a semi-additive method similar to that of the wiring conductors 21 to 24. In addition, each thickness of the wiring conductors 25 and 26 can be exemplified as the same thickness as the thickness exemplified for the first wiring conductor 21. At this time, the wiring conductors 25 and 26 can be formed simultaneously. Therefore, the manufacturing efficiency of the wiring board in the present invention is high.

  Next, as shown in FIG. 3B, the sixth insulating layer 16 and the seventh wiring conductor 27 are formed on the first insulating layer 11 and the fifth wiring conductor 25, and the fifth insulating layer is formed. A seventh insulating layer 17 and an eighth wiring conductor 28 are formed on the 15 and sixth wiring conductors 26. The sixth insulating layer 16 and the seventh insulating layer 17 are preferably made of the same material as the other insulating layers 11 to 15, and the same resin film as that of the insulating layers 11 to 15 is used as the wiring conductor 25, It is formed by adhering to the upper and lower surfaces of the core laminated body 10 having 26 formed thereon and thermosetting the resin film. At this time, the insulating layer 16 and the insulating layer 17 can perform both adhesion of a resin film, thermosetting, etc. simultaneously. Therefore, the manufacturing efficiency of the wiring board in the present invention is high. The thicknesses of the formed insulating layers 17 and 18 can be the same as the thicknesses exemplified for the first insulating layer 11.

  Via holes VH are formed in the insulating layers 16 and 17 in the same manner as in the other insulating layers 11 to 15. The seventh wiring conductor 27 and the eighth wiring conductor 28 are preferably made of the same plating film as the other wiring conductors 21 to 26, and are formed by the same semi-additive method as the wiring conductors 21 to 26. Is preferred. In addition, each thickness of the seventh wiring conductor 27 and the eighth wiring conductor 28 can be exemplified by the same thickness as the thickness exemplified for the first wiring conductor 21. At this time, the wiring conductor 27 and the wiring conductor 28 can be formed simultaneously. Therefore, the manufacturing efficiency of the wiring board in the present invention is high.

  Finally, as shown in FIG. 3C, an eighth insulating layer 18 is formed on the sixth insulating layer 16 and the seventh wiring conductor 27, and the seventh insulating layer 17 and the eighth wiring conductor are formed. A ninth insulating layer 19 is formed on 28. The eighth and ninth insulating layers 18 and 19 increase the electrical insulation reliability of the surface wiring conductors 27 and 28 and function as a protective layer for preventing a short circuit during soldering.

  The eighth and ninth insulating layers 18 and 19 are, for example, photosensitive resins in which an inorganic insulating filler such as silica or talc is contained in a mixture of a photosensitive resin such as an acrylic-modified epoxy resin and a photopolymerization initiator. Formed by applying paste to a thickness of about 10 to 30 μm by screen printing or roll coating, and then exposing and developing to a predetermined pattern using photolithography technology, followed by UV curing and heat curing Is done. Alternatively, a photosensitive resin film obtained by processing the photosensitive resin paste into a film having a thickness of about 10 to 30 μm is pasted by a vacuum laminating apparatus, and then exposed, developed and cured in the same manner.

  As described above, the wiring substrate 100 according to the manufacturing method of the present invention is completed. The wiring board 100 has a thickness of about 200 to 500 μm and suppresses the occurrence of warpage and waviness due to processing, and thus has high flatness and excellent mountability.

  Next, another example of the method for manufacturing a wiring board according to the present invention will be described in detail with reference to the drawings. FIG. 4 is a schematic cross-sectional view showing the process of forming the core laminate according to this example, and corresponds to FIG. 1 (d) described above. In FIG. 4, the same or equivalent parts as those in FIGS.

As shown in FIG. 4, in this example, the step of forming the core laminated body 10 is performed by alternately laminating insulating layers and wiring conductors on the upper and lower surfaces of the support substrate 1, respectively. Is a step of forming a core laminate 10 composed of Thereby, compared with the case where the core laminated body 10 is formed in the main surface of the support substrate 1 demonstrated above, the efficiency which forms the core laminated body 10 can be improved about 2 times.
Here, although the support substrate 1 has a flat main surface (upper surface), in this example, it is preferable that the lower surface of the support substrate 1 is also flat, that is, the upper and lower surfaces of the support substrate 1 are flat.

  Note that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention. For example, in the above-described embodiment, the number of insulating layers constituting the core laminated body 10 is five, and the number of insulating layers stacked on the core laminated body 10 has been described as two upper and lower layers. However, the number of insulating layers constituting the core laminate 10 and the number of insulating layers laminated thereon can be appropriately changed according to specifications required for the wiring board. Further, any one of the upper and lower surfaces of the core laminate 10 may be the electronic component mounting surface side.

(A)-(d) is a schematic sectional drawing which shows the process of forming the core laminated body concerning the manufacturing method of the wiring board of this invention. It is a schematic sectional drawing which shows the state which peeled the core laminated body from the support substrate. (A)-(c) is a schematic sectional drawing which shows the process of laminating | stacking a wiring conductor and an insulating layer alternately on the upper and lower surfaces of a core laminated body. It is a schematic sectional drawing which shows the process of forming the core laminated body concerning the other example of this invention. It is a schematic sectional drawing which shows a general buildup wiring board.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Support substrate 10 ... Core laminated body 11-19 ... Insulating layer 21-28 ... Wiring conductor 100 ... Wiring board

Claims (5)

A step of alternately laminating insulating layers and wiring conductors on the main surface of the support substrate to form a core laminate composed of the insulating layers and the wiring conductors;
Peeling the core laminate from the support substrate;
And a step of alternately laminating a wiring conductor and an insulating layer on both upper and lower surfaces of the peeled core laminate.   The method for manufacturing a wiring board according to claim 1, wherein a main surface of the support substrate is flat.   The method for manufacturing a wiring board according to claim 1, wherein the wiring conductor is formed by a semi-additive method. The step of forming the core laminate includes a step of interposing a predetermined adhesive layer between the support substrate and the core laminate,
The process of peeling the said core laminated body from the said support substrate is a process of peeling the said core laminated body from the said support substrate, after reducing or lose | eliminating the adhesive force of the said contact bonding layer. The manufacturing method of the wiring board as described in 2 .. The step of forming the core laminate is a step of forming a core laminate comprising the insulating layer and the wiring conductor by alternately laminating insulating layers and wiring conductors on the upper and lower surfaces of the support substrate. The manufacturing method of the wiring board in any one of Claims 1-4.

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