JP2001237549A - Multilayered wiring board and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve such a problem that sufficient interlayer connection becomes impossible and, accordingly, the yield of a multilayered wiring board terribly drops due to the positional deviations of land sections and via hole sections in each layer caused by the variable dimensional change of a substrate material resulting from the elongation/contraction of the material, when the material is subjected to variable temperatures and moistures through the manufacturing process of the wiring board in manufacturing the wiring board to meet the requirements of reducing the line width of wiring and the diameters of via holes and increasing the number of layers. SOLUTION: This multilayered wiring board is constituted by arranging a plurality of fine substrates 22, which have small areas and on and in which fine wiring and small-diameter via holes are formed, on a core substrate 21 having a relatively rough rule and a large area and laminating the substrates 22 upon the core substrate 21 so that electric connection may be obtained between them. Then the substrates 22 are aligned and laminated, respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-layer wiring board and a method of manufacturing the same, and more particularly, for example, a multi-layer wiring board formed by connecting a plurality of high-density wiring patterns in a multi-cavity and a multi-layer wiring board having the same. It relates to a manufacturing method.

[0002]

2. Description of the Related Art In recent years, as electronic devices have become smaller and denser,
There is a strong demand for multilayer wiring boards not only for industrial use but also in the field of consumer electronics. In particular, the increase in the density of the multilayer wiring board promotes the miniaturization of the wiring pattern, and therefore, the lamination accuracy between a plurality of wiring layers affects its performance. Therefore, a manufacturing method with high lamination accuracy is desired.

A conventional multilayer wiring board and a method of manufacturing the same will be described below by taking a four-layer board as an example. First, a method for manufacturing a double-sided wiring substrate serving as a base of a multilayer substrate will be described.

FIGS. 6A to 6F are cross-sectional views showing the steps of a conventional method for manufacturing a double-sided wiring board. In the figure, 1
Is, for example, 340 mm × 510 mm and the thickness t1 is about 15
It is a 0 μm prepreg sheet, for example, a base material (hereinafter, referred to as an aramid-epoxy sheet) made of a composite material in which a non-woven aromatic polyamide fiber is impregnated with a thermosetting epoxy resin.

[0005] Reference numeral 5 denotes a plastic sheet having a thickness of about 20 µm and coated on one side with a Si-based release agent. For example, polyethylene terephthalate (hereinafter referred to as a PET sheet) is used. 3 is a through hole (via hole),
18μm thickness attached to both sides of epoxy sheet 1
Is filled with a conductive paste 2 electrically connected to a metal foil 4 such as Cu.

First, as shown in FIG. 6 (b), a predetermined portion of an aramid-epoxy sheet 1 (FIG. 6 (a)) having a PET sheet 5 bonded to both sides is penetrated by using a laser processing method or the like. A hole 3 is formed. Next, as a method of filling the conductive paste 2, the aramid-epoxy sheet 1 having the through holes 3 is placed on a table of a screen printing machine (not shown), and the conductive paste 2 is directly placed on the PET sheet 5 from above. Printed. At this time, the PET sheet 5 on the upper surface plays a role of a print mask and a role of preventing contamination of the surface of the aramid-epoxy sheet 1.

[0007] Next, as shown in FIG.
The PET sheet 5 is peeled off from both sides of the epoxy sheet 1. Then, a metal foil 4 made of Cu or the like is overlaid on both surfaces of the aramid-epoxy sheet 1 and heated and pressed by a hot press to compress the thickness of the aramid-epoxy sheet 1 as shown in FIG. 6 (e) (t2 = Aramid-epoxy sheet 1 and metal foil 4 are adhered together with about 100 μm),
The metal foils 4 on both sides are electrically connected by the conductive paste 2 filling the through holes 3 provided at predetermined positions. Then, the metal foils 4 on both sides of FIG. 6F are selectively etched to form the wiring patterns 11a and 11b, thereby obtaining the double-sided wiring board 10.

FIGS. 7A to 7C are process sectional views showing a conventional method for manufacturing a multilayer wiring board, and show a four-layer board as an example. First, as shown in FIG.
Wiring pattern 11 manufactured according to (a) to (f)
a, an aramid-epoxy sheet 1 filled with conductive paste 2 in through holes 3
a, 1b (the sheets 1a, 1b are shown in FIGS.
(Manufactured by the process (d)). Aramid-epoxy sheet 1 on work stage (not shown)
b, double-sided wiring board 10, aramid-epoxy sheet 1a
In this order, the positioning holes 6 are positioned by image recognition or the like and overlapped.

Next, as shown in FIG. 7 (b), after laminating the metal foils 4 on both sides, the whole surface is pressed by a hot press at a pressure of 50 kg / c.
The thickness of the aramid-epoxy sheets 1a and 1b is compressed by heating under pressure at 200 ° C. for 1 hour at a temperature of 200 m ² , and the aramid-epoxy sheets 1a and 1b are compressed.
Then, the double-sided wiring board 10 and the metal foil 4 are bonded to each other, and the wiring patterns 11 a and 11 b are connected to the metal foil 4 and the inner via holes by the conductive paste 2. Then, as shown in FIG. 7C, the four-layer substrate is obtained by selectively etching the metal foils 4 on both surfaces to form the wiring patterns 12a and 12b.

By using the above-described manufacturing method, a conventional multilayer wiring board can be obtained. In addition, 4
In order to obtain a multilayer wiring board having more than two layers, the same process may be repeated using the multilayer wiring board manufactured by the above-described manufacturing method instead of the double-sided wiring board.

In general, a multilayer wiring board is manufactured by forming a large number of identical circuit board patterns on one board and dividing the same after the final step. It is important for the yield.

[0012]

However, in the above-mentioned conventional structure, in response to the demands for further miniaturization of wiring, reduction in the diameter of vias, and increase in the number of multilayers, which are expected in the future, it is necessary to increase the number of processes that pass through when manufacturing a multilayer wiring board. Because the substrate material expands and contracts due to temperature changes and moisture absorption, and the dimensional changes vary,
There is a major problem in that the positions of the lands and vias are displaced in each layer, making it impossible to establish a sufficient connection between the layers and severely lowering the yield.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a multilayer wiring board having a high stacking accuracy and a high yield, and a method of manufacturing the same in order to solve the above-mentioned conventional problems.

[0014]

In order to achieve the above-mentioned object, the present invention is configured as follows.

That is, the multilayer wiring board of the present invention has a first
And a second wiring board having a finer wiring rule than the first wiring board.

According to the present invention, it is possible to form a second wiring board having a finer wiring rule as a criterion when wiring a pattern of the wiring board with an area smaller than that of the first wiring board. It is possible to suppress variations in dimensional change of the substrate material due to the temperature and moisture in the process of passing when manufacturing the multilayer wiring substrate.

[0017]

The invention according to claim 1 of the present invention is such that a second wiring board having a finer wiring rule than the first wiring board is laminated on the first wiring board, The second wiring board having a fine wiring rule can be formed with an area smaller than that of the first wiring board. It becomes possible to suppress.

According to a second aspect of the present invention, in the first aspect of the present invention, the second wiring board is laminated only on a part of the first wiring board. The desired multilayer wiring board can be obtained by laminating it at the desired position above.

The third aspect of the present invention is the first or second aspect.
In the invention described in the above, a plurality of the second wiring boards are arranged and laminated on the first wiring board, and the plurality of second wiring boards are individually arranged on the first wiring board. Therefore, a multilayer wiring board having high stacking accuracy and excellent yield can be obtained.

According to a fourth aspect of the present invention, in the third aspect of the invention, the plurality of second wiring boards are of different types, and each of the different types of second wiring boards is connected to the first wiring board. The intended multilayer wiring board can be obtained by laminating at a predetermined place of the wiring board.

[0021] The invention according to claim 5 is the invention according to claims 1 to 4.
In the invention described in any one of the first to fourth aspects, the first wiring board and the second wiring board may electrically connect an insulating layer, a wiring layer disposed via the insulating layer, and the wiring layers. The two wiring boards are laminated via an intermediate connector, and the surface wiring layers of the first wiring board and the surface wiring layer of the second wiring board are electrically connected to each other. And a multi-layer wiring board with less dimensional variation can be obtained.

According to a sixth aspect of the present invention, in the fifth aspect of the invention, the second wiring board is embedded and laminated in the intermediate connector, and the second wiring board is laminated. Since the planar smoothness on the side is good, the mountability is good.

The invention according to claim 7 is the invention according to claim 5 or 6.
In the invention described in the above, the interlayer connection body is a conductive paste filled in a through hole penetrating an insulating layer, and a multilayer wiring board connected to an inner via hole can be obtained.

[0024] The invention according to claim 8 provides the invention according to claims 5 to 7.
In the invention described in any one of the first to third aspects, the insulating layer of the first wiring board and the insulating layer of the second wiring board are made of different materials, and a material suitable for the purpose, for example, has a small hygroscopic property and a small size. Materials with little change can be used.

According to a ninth aspect of the present invention, there is provided a method of manufacturing a first wiring board, a step of manufacturing a second wiring board having a finer wiring rule than the first wiring board, A second wiring board having a fine wiring rule in an area smaller than that of the first wiring board, so that a temperature change in a step of passing through at the time of manufacturing the multilayer wiring board is achieved. It is possible to suppress variation in dimensional change of the substrate material due to moisture and moisture.

According to a tenth aspect of the present invention, in the ninth aspect of the present invention, the step of manufacturing the first wiring board comprises forming a through-hole in an insulating base material provided with a release film, and forming a conductive paste on the insulating base material. And a step of laminating a metal foil on both sides of the insulating base material from which the release film has been peeled off and heating and pressurizing, wherein the step of manufacturing the second wiring board comprises a release film Forming a through hole in the insulating base material and filling the conductive paste, and a step of temporarily bonding a metal foil on both surfaces of the insulating base material peeled off the release film, The step of laminating both wiring boards includes a step of superimposing the second wiring board on the first wiring board, and heating and pressurizing to integrate the second wiring board. Temporary bonding (temporary lamination) at low temperature,
After being arranged on the first wiring board, they are collectively heated and pressed so as to be integrally laminated so that electrical connection can be obtained. Can be suppressed small, and a multilayer wiring board corresponding to fine wiring can be obtained.

According to an eleventh aspect of the present invention, in the ninth or tenth aspect of the present invention, the step of laminating the two wiring boards includes the step of laminating the second wiring board on the first wiring board via an intermediate connector. The wiring substrates are stacked and heated and pressurized to integrate them. The planar smoothness of the side on which the second wiring substrate is laminated is improved, so that the mountability is improved.

According to a twelfth aspect of the present invention, in the invention according to any one of the ninth to eleventh aspects, the step of laminating the two wiring boards is performed only on a part of the first wiring board. Are stacked and heated and pressed to integrate them, and the second wiring board is laminated at a desired position on the first wiring board to obtain a target multilayer wiring board.

According to a thirteenth aspect of the present invention, in the invention according to any one of the ninth to eleventh aspects, the step of manufacturing the two wiring boards includes the step of: forming the second wiring board on the first wiring board.
A plurality of the wiring boards are arranged and integrated by heating and pressurizing, and a multilayer wiring board with high stacking accuracy and high yield can be obtained.

The invention according to claim 14 is the invention according to any one of claims 10 to 13, wherein the insulating base material and the second insulating substrate are formed in a step of manufacturing the first wiring board.
The insulating substrate in the manufacturing process of the wiring substrate is a different material, and a material suitable for the purpose, for example, a material having a small hygroscopic property and a small dimensional change can be used.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1) FIG. 1 is a perspective view showing an embodiment of the present invention, and is an example of a form in which a multilayer wiring board of the present invention is cut into an optimum size for mounting on a mounting machine.

The multilayer wiring board of this embodiment has a relatively large wiring rule for defining the pattern width, gap, hole diameter, land diameter, conductor thickness, number of conductor layers, interlayer distance, hole position, etc., and has a large area. Core substrate 21 as first wiring substrate
A plurality of fine substrates 22 are arranged thereon as a second wiring substrate having a smaller wiring rule and a smaller area than the core substrate 21, and are stacked so that electrical connection can be obtained. Reference numeral 22 denotes a layer that is individually aligned and stacked.

The core substrate 21 is made of, for example, a composite material of a woven or non-woven fabric mainly composed of synthetic fibers or inorganic fibers and a thermosetting resin, and is compressed by heating and pressing during lamination pressing. A compressible material, for example, a composite material of a woven or non-woven fabric with an aromatic polyamide as a main material and a thermosetting epoxy resin, or a woven or non-woven fabric with a glass fiber as a main material and a thermosetting epoxy resin Is used.

The core substrate 21 is manufactured by the manufacturing method described in the above-mentioned conventional technique, and is manufactured in a large-sized state by taking a large number of pieces in FIG.

The fine substrate 22 is made of a material in which a thermosetting adhesive is applied to both surfaces of a heat-resistant film, and when heated and pressed by a laminating press, the adhesive flows, as if it were a material having compressibility. A material that behaves, for example, a polyimide film on both sides of which a polyimide-based thermosetting adhesive is applied is used as a base material.

Both the core substrate 21 and the fine substrate 22
It has a via hole for interlayer connection. The via hole is filled with a conductive paste, and the conductive paste is compressed by the wiring pattern on both sides of the via hole by heating and pressurizing with a lamination press. Connection can be obtained. Here, the conductive paste includes, for example, at least one metal powder selected from Cu, Ag and an alloy thereof and a thermosetting epoxy resin,
Due to the effect of the thickness of the wiring pattern formed in advance on another supporting base material and the compressible base material, the conductive paste filled in the via holes is compressed at the time of laminating press to obtain electrical connection.

The fine substrates 22 are individually aligned on the core substrate 21 by the alignment marks 23. FIG. 1 shows a fine substrate 2 on a core substrate 21.
2 shows an example in which the fine substrates 22 are regularly arranged, but the fine substrate 22 may be arranged at an arbitrary position. Further, the fine substrate 22 may be spread without any gap. Further, even if the fine substrate 22 is a substrate having several types of different wiring patterns, it can be applied to the multilayer wiring substrate of the present invention.

When the fine substrate 22 is arranged as shown in FIG. 1, the fine substrate 22 may be laminated so as to be embedded in the core substrate 21.

Next, a method for manufacturing a multilayer wiring board according to the present invention will be described with reference to FIG. FIGS. 2 (a) to 2 (g)
FIG. 4 is a process cross-sectional view illustrating a manufacturing method for forming a two-layer fine substrate in the multilayer wiring board of the present invention.

In FIG. 2, reference numeral 31 denotes a thickness of about 12.5 μm.
The heat-resistant film material is used as a base material of the fine substrate 22 in FIG. 1, and for example, a material such as a polyimide film is used. Although the thickness of the polyimide film is, for example, 12.5 μm, a thick film or a thin film may be used depending on the diameter of a via hole for making electrical connection between layers.

Reference numeral 32 denotes an adhesive layer having a thickness of about 5 μm applied to both surfaces of the film base material 31. For example, a polyimide-based thermosetting adhesive can be used. 33 is Si on one side
A plastic sheet as a release film having a thickness of about 9 μm coated with a system release agent, for example, polyethylene naphthalate (hereinafter referred to as a PEN sheet). The wiring pattern 41a is formed on the support substrate 42a in advance by an etching method or an additive plating method in another step. 34 is a through hole (via hole),
Is filled with a conductive paste 35 for electrically connecting the wiring patterns 41a and 41b, such as Cu, having a thickness of about 9 μm to be attached to both surfaces of the substrate.

First, PEN is applied to both surfaces shown in FIG.
As shown in FIG. 2B, a through hole 34 having a hole diameter of about 50 μm is formed in a predetermined portion of the film substrate 31 with the adhesive layer 32 to which the sheet 33 is adhered, using a laser processing method or the like. You. The laser used here is, for example, an ultraviolet laser such as a YAG laser.

Next, as a method of filling the conductive paste 35, a film substrate 31 with an adhesive layer 32 having a through hole 34 is placed on a table of a screen printing machine (not shown), A paste 35 such as a Cu paste or an alloy paste of Ag and Cu is used as the PEN sheet 33.
Printed from above. At this time, the PEN sheet 33 on the upper surface
Plays a role of a print mask and a role of preventing contamination of the surface of the film substrate 31 with the adhesive layer 32.

Next, as shown in FIG. 2D, the adhesive layer 3
The PEN sheet 33 is peeled off from both sides of the film substrate 31 with the two. Then, as shown in FIG. 2E, the support substrate 4 on which the wiring pattern 41a is formed in advance with a metal such as Cu.
2a and metal foil 41b such as Cu having no wiring pattern formed thereon
Is provided on both sides of the film substrate 31 with the adhesive layer 32.

Next, as shown in FIG. 2 (f), on a support substrate 42b on which a metal foil 41b of Cu or the like is formed, a support substrate 42a on which a wiring pattern 41a is formed
(D) The vias of the film substrate 31 with the adhesive layer 32 are aligned, and the wiring pattern 41a and the adhesive 32 are temporarily bonded by pressing at a low temperature of about 40 to 60 ° C. Next, as shown in FIG. 2G, by removing the supporting substrate 42a by a method such as etching, the wiring pattern 41a appears on the substrate surface, and a two-layer fine substrate can be obtained.

The transferred wiring pattern is usually 40 μm.
UTC copper foil manufactured by Mitsui Kinzoku Mining Co., Ltd., which is formed by plating 9 μm Cu on an Al foil having a thickness of
Only the Cu portion of the copper foil is selectively etched to form a wiring pattern. Alternatively, the wiring pattern may be formed by subjecting the Al foil to Cu plating in a predetermined wiring pattern shape.

The land portion of the transfer copper foil on which such a wiring pattern is formed and the via hole portion of the film base material 31 filled with the conductive paste 35 are aligned and overlapped with each other. The wiring pattern is temporarily bonded to the film substrate by temporarily pressing at a low temperature of ６０60 ° C. and a pressure of 50〜160 kg / cm ² for several minutes. After the temporary bonding, by selectively etching away only the Al foil, the fine substrates 22 on both sides can be obtained as described above.

Since the fine substrate 22 requires high alignment accuracy, it is usually manufactured with a work size of about 50 to 150 mm square. By reducing the work size, a dimensional change of the base material, a dimensional variation caused by the dimensional change, and the like can be suppressed to be small, and an improvement in lamination accuracy can be realized.

Next, a manufacturing method for forming a three-layer substrate by further laminating fine substrates will be described with reference to the process sectional views of FIGS. 3 (a) to 3 (c).

In FIG. 3A, reference numeral 51 denotes a two-layer fine substrate manufactured in the manufacturing process shown in FIG. 2, which is the same as that shown in FIG. 2G. Reference numeral 52 denotes a film corresponding to FIG. 2D, which is obtained by performing laser hole processing on the film base material 31 with the adhesive layer 32, filling with a paste, and peeling off the PEN sheet 33. Numeral 53 denotes a wiring pattern 41c formed of a metal such as u on the support base 42c in advance. 2
After aligning and overlaying the wiring pattern of the layered fine substrate 51, the via hole of the paste-filled film base material 52, and the wiring pattern of the support base material 53 on which the wiring pattern is formed, about 40 to 60 ° C. FIG. 3 (b) shows what was temporarily bonded by pressing at a low temperature.

Next, as shown in FIG.
By removing 2c using a method such as etching, the wiring pattern 41c appears on the substrate surface, and a three-layer fine substrate can be obtained. A fine substrate in which four or more layers are laminated can be obtained by repeating the manufacturing process of FIG.

FIG. 4 is a process sectional view showing a process of manufacturing a wiring pattern to be connected to the core substrate 21 of the fine substrate 22. A case where a two-layer fine substrate is laminated on a core substrate will be described with reference to FIGS.

FIG. 4 (a) shows the same process as FIG. 2 (f) used for the description of the manufacturing process of the fine substrate, and the wiring pattern 41a is formed on the film base 52 which has been filled with the paste.
Support substrate 42a on which a metal foil 41b such as Cu on which a wiring pattern is not formed is formed.
b was temporarily bonded. FIG. 4B shows the supporting substrate 42.
This shows a state where b has been removed by a method such as etching. Next, the metal foil 41b appearing on the surface is patterned into a predetermined shape using, for example, a method such as exposure and etching to obtain a wiring pattern 41b ′ connected to the core substrate.

Next, a method of laminating the core substrate 21 and the fine substrate 22 will be described. The core substrate 21 is manufactured, for example, using the method of FIGS. 6 and 7 described in the related art. This core substrate 21 is 550 mm square or 510 ×
It is manufactured with a relatively large work size such as 340 mm. Therefore, when laminating the core substrate 21 and the fine substrate 22, a plurality of fine substrates 22 are usually required for one core substrate 21. Needless to say, only one fine substrate 22 may be disposed on one core substrate 21 or may be partially disposed.

A method of laminating a core substrate and a fine substrate using a four-layer substrate as an example will be described with reference to FIG.

In FIG. 5A, reference numeral 61 denotes a wiring pattern 4 manufactured by the method described with reference to FIG.
1b ′ is a fine substrate. Reference numeral 62 denotes a core substrate manufactured by the method described with reference to FIG. Reference numeral 63 denotes an aramid-epoxy sheet as an intermediate connector in which the via of FIG. 6D is filled with a conductive paste, which is manufactured by the method described with reference to FIG. The fine substrate 61, the aramid-epoxy sheet 63, and the core substrate 62 are aligned using alignment marks 64 formed at predetermined positions, and are laminated and integrated as shown in FIG. .

At this time, in the fine substrate 61 in the temporarily bonded state, the wiring pattern 41a is embedded in the adhesive layer,
The paste in the via 35 is compressed to obtain electrical conduction. Similarly, in the aramid-epoxy sheet 63,
Since the wiring patterns 41b 'and 11a are embedded in the aramid-epoxy sheet and at the same time compress the sheet, electrical connection of vias is made. That is, by compressing the conductive paste in the via hole at the same time that the wiring pattern transferred to the fine substrate 22 is buried in the adhesive melted by the pressing temperature from the state of the temporary bonding,
Electrical connection of a 50 μm via in the fine substrate 22 can be made. Further, the aramid-epoxy sheet 63 of FIG. 5 is also compressed by the hot press, and the conduction of the via holes can be obtained. Therefore, only when the state shown in FIG. 5B is reached, the electrical connection of the vias of all layers is made. At this time, as shown in FIG.
Embedded in epoxy sheet. Depending on the pressure applied during heating and pressing, the fine substrate 61 itself may not be embedded, and only the wiring pattern 41b 'may be embedded in the aramid-epoxy sheet.

The pressing conditions for the above-mentioned lamination were set to a temperature of 2
By using a vacuum press at 00 ° C. and a pressure of about 160 kg / cm ² , not only the wiring pattern 41 b ′ connected to the core substrate of the fine substrate but also the fine substrate itself can be embedded in the aramid-epoxy sheet 63. It is laminated. This is a possible structure because the base material of the fan substrate is as thin as 12.5 μm, and the flatness on the side on which the fine substrate is laminated is improved, so that the mountability is improved. The aramid used for the connection layer with the core substrate
Since the amount of compression applied to the vias of the epoxy sheet increases, the multilayer wiring board has very good via connection reliability. In addition, since the core substrate itself has a structure that can be embedded, even when fine substrates having different thicknesses are stacked on the same core substrate, it is possible to compress the fine substrate while maintaining a flat substrate surface.

The pressing conditions at the time of laminating are as follows:
By performing a vacuum press at a temperature of 00 ° C. and a pressure of 50 kg / cm ² , the wiring pattern 41 b ′ connected to the core substrate of the fine substrate is laminated so as to be embedded in the aramid-epoxy sheet 63.

It should be noted that, even when the core substrate 21 and the fine substrate 22 have the same area, or conversely, when the area of the core substrate 21 is smaller than that of the fine substrate 22, they are formed at predetermined positions. After performing alignment using the alignment mark, by applying heat and pressure, it is possible to perform integrated lamination.

Next, the supporting base material 42a is removed by a method such as etching to obtain a multilayer wiring board of the present invention as shown in FIG. 5 (c).

(Other Embodiments) As another embodiment of the present invention, fine wiring boards having different wiring patterns and the number of laminated layers or different wiring areas are aligned and arranged on the same core substrate. And may be stacked. The fine substrate is manufactured in a step different from that of the core substrate, and is also individually aligned at the time of lamination with the core substrate, so that a multilayer wiring substrate having such a configuration can be manufactured. This multilayer wiring board is an M-type board for mounting a variety of LSIs.
It is used when it is desired to attach various types of boards to a CM board or a single core board.

Although the aramid-epoxy sheet 63 as the intermediate connector shown in FIG. 5 has the area and the wiring rule corresponding to the core substrate 62, the wiring of the fine substrate 61 is another embodiment of the present invention. It may be manufactured according to a rule, or may be divided according to the area of each fine substrate 61.

In the above embodiment, the fine substrate 61
Is subjected to temporary bonding (temporary lamination) by pressing at a low temperature and finally heated and pressed together with the core substrate 62 to integrate all the layers. However, as another embodiment of the present invention, a fine substrate Instead of temporary bonding, the electrical connection of the vias of the fine substrate may be performed in advance by pressing at a high temperature.

As another embodiment of the present invention, as shown by the imaginary lines in FIG. 1 and FIG. 5C, the core substrate is divided and cut, and a fine substrate having almost the same area is formed on the core substrate. It may be a multilayer wiring board in which boards are stacked.

In the above embodiment, the fine substrate is
Although a film substrate is used, another embodiment of the present invention may use the same material as the core substrate, for example, an aramid-epoxy sheet.

[0068]

As described above, according to the present invention, the second wiring board having a fine wiring rule is laminated on the first wiring board, and the second wiring board has a small area. Therefore, it is possible to suppress variations in dimensional change of the substrate material due to the temperature and moisture in the process of passing when manufacturing the multilayer wiring substrate. In addition, since the second wiring board is individually aligned and stacked on the first wiring board, a multilayer wiring board having high stacking accuracy and excellent yield can be obtained.

Further, since different types of second wiring boards are arranged and stacked at predetermined positions on the first wiring board,
An intended multilayer wiring board can be obtained.

Further, the second wiring boards are temporarily bonded (temporarily laminated) at a low temperature, and are arranged while being individually aligned at predetermined positions on the first wiring board having relatively coarse wiring rules. Finally, since they are integrated and laminated so that electrical connection can be obtained by heating and pressing all at once, it is possible to pass through the manufacturing process of the multilayer wiring board at a low temperature and to reduce the dimensional variation of the substrate material, A multilayer wiring board corresponding to the wiring can be obtained.

[Brief description of the drawings]

FIG. 1 is a structural diagram of a multilayer wiring board of the present invention.

FIG. 2 is a process sectional view illustrating a method for manufacturing a two-layer fine substrate.

FIG. 3 is a process cross-sectional view illustrating a method of laminating a third layer of the fine substrate.

FIG. 4 is a process sectional view illustrating a method for manufacturing a wiring pattern connected to a core substrate of a fine substrate.

FIG. 5 is a process sectional view showing a method for laminating a fine substrate and a core substrate of the multilayer wiring board of the present invention.

FIG. 6 is a process sectional view illustrating a conventional method for manufacturing a two-layer multilayer wiring board.

FIG. 7 is a process sectional view illustrating a conventional method for manufacturing a four-layer multilayer wiring board.

[Explanation of symbols]

1, 1a, 1b, 63 Aramid-epoxy sheet 2, 35 Conductive paste 3, 34 Via hole 4 Metal foil 5 PET sheet 6, 23 Alignment mark 10 Two-layer multilayer wiring board 11a, 11b, 12a, 12b Wiring pattern 21, 62 Core substrate 22 Fine substrate 31, 52 Film substrate 32 Adhesive 33 PEN sheet 41a, 41c Transfer wiring pattern 41b Copper foil 41b 'Wiring pattern 42a, 42b, 42c connected to core substrate Supporting substrate 51, 61 2 layers Fine substrate 53 Transfer pattern

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Toshio Sugawa 1006 Kazuma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. Terms (reference) 5E317 AA24 BB01 BB11 CC22 CC25 CC53 GG14 5E338 AA03 BB02 BB13 BB25 BB31 CC01 CD01 CD14 EE33 5E346 AA06 CC05 CC09 CC10 CC32 CC34 DD22 EE02 EE09 FF01 FF18 GG15 GG17 GG22 HH26H33 H33

Claims (14)

[Claims] 1. A multilayer wiring board comprising: a second wiring board having a wiring rule finer than that of the first wiring board, laminated on the first wiring board. 2. The multilayer wiring board according to claim 1, wherein said second wiring board is laminated only on a part of said first wiring board. 3. The semiconductor device according to claim 2, wherein a plurality of the second wiring boards are connected to the first wiring board.
3. The semiconductor device according to claim 1, which is arranged on said wiring board and laminated.
The multilayer wiring board as described in the above. 4. The multilayer wiring board according to claim 3, wherein the plurality of second wiring boards are of different types. 5. The first wiring board and the second wiring board each include an insulating layer, a wiring layer disposed via the insulating layer, and an interlayer connector for electrically connecting the wiring layers to each other. Wherein the two wiring boards are laminated via an intermediate connector, and the surface wiring layer of the first wiring board and the surface wiring layer of the second wiring board are electrically connected to each other. The multilayer wiring board according to claim 1. 6. The multilayer wiring board according to claim 5, wherein the second wiring board is buried and laminated in the intermediate connector. 7. The multilayer wiring board according to claim 5, wherein the interlayer connection body is a conductive paste filled in a through hole penetrating the insulating layer. 8. The multilayer wiring board according to claim 5, wherein said insulating layer of said first wiring board and said insulating layer of said second wiring board are made of different materials. 9. A step of manufacturing a first wiring board, a step of manufacturing a second wiring board having a wiring rule finer than that of the first wiring board, and a step of laminating the two wiring boards. A method for manufacturing a multilayer wiring board, comprising: 10. The step of manufacturing the first wiring board includes the steps of forming a through hole in an insulating base material provided with a release film and filling a conductive paste, and peeling the release film. Laminating a metal foil on both surfaces of the insulating base material and applying heat and pressure. The step of manufacturing the second wiring board includes forming a through hole in the insulating base material having a release film to form a conductive film. A step of filling a paste and a step of laminating and temporarily bonding metal foils on both surfaces of the insulating base material from which the release film has been peeled off, The method for manufacturing a multilayer wiring board according to claim 9, further comprising a step of superposing the second wiring board on the board, heating and pressurizing to integrate the second wiring board. 11. The step of laminating both wiring boards, wherein the second wiring board is overlapped on the first wiring board via an intermediate connector, and integrated by heating and pressing. 11. The method for manufacturing a multilayer wiring board according to item 10. 12. The method according to claim 9, wherein in the step of laminating the two wiring boards, the second wiring board is overlapped only on a part of the first wiring board, and integrated by heating and pressing.
The method for manufacturing a multilayer wiring board according to any one of the above. 13. The method according to claim 9, wherein in the step of manufacturing both wiring boards, a plurality of the second wiring boards are arranged on the first wiring board, respectively, and integrated by heating and pressing. A method for manufacturing the multilayer wiring board according to any one of the above. 14. The insulating substrate according to claim 10, wherein the insulating base in the step of manufacturing the first wiring board and the insulating base in the step of manufacturing the second wiring board are made of different materials. 13. A method for manufacturing a multilayer wiring board according to