JPH10303561A - Multi-layer wiring board and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simply connect layers and wiring electrically by laminating a board having wirings and layer connecting terminals which are higher than the wirings and a conductive layer having layer connecting terminals and wirings such that the layer connecting terminals of the board ate opposed to those of the conductive layer and by bringing the layer connecting terminals of the board in a continuity with those of the conductive layer. SOLUTION: Wirings 2 and connection terminals 3 are formed on a base board 1. A plated resist 4 is formed on the base board 1 such that only the connection terminals 3 are exposed. All openings of the plated resist 4 are plated with gold 5 such that the connection terminals 3 are raised above the wirings 2 and the plated resist 4 is removed. An adhesive 6 is arranged on the base board 1 and a built-up wiring 8 formed on a conductive supporting body 7 is arranged such that connection terminals 9 of the built-up side are opposed to the wiring of the base board 1 and are connected thereto in a predetermined manner and is heated and pressed on the adhesive 6 and is integrated with the base board 1. This can simply connect the layers and wirings electrically without forming a through hole.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a multilayer wiring board and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, a multilayer wiring board is mainly made of a glass cloth epoxy resin laminated board with copper foil or a glass cloth polyimide resin laminated board with copper foil as a material, and drilling, through-hole plating, outer layer wiring formation and the like. Manufacturing is performed by a method of repeating heating and pressing by a vacuum press machine. FIG. 1 shows a schematic sectional view of a multilayer wiring board manufactured by the above method. In this method, it is difficult to form a small-diameter via hole having a diameter of about 100 μm by drilling, so that both the via diameter and the land diameter increase, and the wiring density cannot be increased. In addition, in order to perform interlayer connection to through-hole plating,
In a multilayer wiring board in which lamination is performed twice or three times, the conductor thickness of the outermost layer is larger than the initial copper foil thickness by the amount of plating, and is not suitable for forming fine wiring.

On the other hand, in recent years, a build-up type multilayer wiring board has been put to practical use. In this method, wiring and via holes for interlayer connection are formed for each layer and are successively overlapped. By combining small-diameter drilling technology typified by a photo method or a laser method with fine wiring, a high-density wiring substrate is formed. Can be obtained. FIG. 2 is a schematic cross-sectional view of a build-up type multilayer wiring board using a photo method.

[0004]

However, in these methods, plating is performed in a via hole to obtain an electrical interlayer connection. Therefore, as the hole diameter decreases to 100 μm or less, the plating deposition property decreases. Therefore, it becomes difficult to stabilize the connection reliability. In addition, since the via hole portion has a concave shape, an upper via hole cannot be formed directly above the lower via hole when the build-up method overlaps several layers, and the wiring area is reduced. Further, the concave shape of the surface layer may be a constraint when mounting a semiconductor component or the like. SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems of the prior art, and provides a multilayer wiring board which can be formed at high density with a simple process of interlayer connection and wiring, and which can obtain stable connection reliability, and a method of manufacturing the same. Things.

[0005]

A first multilayer wiring board according to the present invention has a substrate on which a wiring and an interlayer connection terminal having a height higher than the wiring are formed, and a board corresponding to the interlayer connection terminal of the substrate. The conductor layer on which the interlayer connection terminal and the wiring are formed is laminated and integrated via an adhesive with the interlayer connection terminal of the substrate facing the interlayer connection terminal of the conductor layer, and the interlayer is formed. The connection terminals are electrically connected to each other.

A second multilayer wiring board according to the present invention includes a conductor layer on which a wiring and an interlayer connection terminal having a height higher than the wiring are formed, and an interlayer connection terminal corresponding to the interlayer connection terminal of the conductor layer. And the substrate on which the wiring is formed, the interlayer connection terminals of the conductor layer and the interlayer connection terminals of the substrate are laminated and integrated via an adhesive with the interlayer connection terminals facing each other. It is characterized by being electrically conductive.

[0007] The first method for manufacturing a multilayer wiring board of the present application is as follows.
The method includes the following steps 3a to 3e. 3a. A step of preparing a substrate on which wiring and interlayer connection terminals are formed; 3b. Forming an interlayer connection terminal and a wiring corresponding to the interlayer connection terminal of the substrate on a support. 3c. Forming an interlayer connection terminal of the substrate higher than a wiring in the same plane; 3d. A step of aligning the interlayer connection terminals of the substrate with the corresponding interlayer connection terminals formed on the support, bonding them with an adhesive, and electrically connecting the interlayer connection terminals. . 3e. Removing and removing the support.

[0008] The second method of manufacturing a multilayer wiring board of the present application is as follows.
The method includes the following steps 4a to 4e. 4a. A step of preparing a substrate on which wiring and interlayer connection terminals are formed; 4b. Forming an interlayer connection terminal and a wiring corresponding to the interlayer connection terminal of the substrate on a support. 4c. Forming an interlayer connection terminal formed on the support above a wiring in the same plane; 4d. A step of aligning the interlayer connection terminals of the substrate with the corresponding interlayer connection terminals formed on the support, bonding them with an adhesive, and electrically connecting the interlayer connection terminals. . 4e. Removing and removing the support.

[0009] The third method of manufacturing a multilayer wiring board of the present application is as follows.
The method includes the following steps 5a to 5e. 5a. A step of preparing a substrate on which wiring and interlayer connection terminals are formed; 5b. Forming on the support a terminal for interlayer connection corresponding to the terminal for interlayer connection of the substrate 5c. A step of aligning the interlayer connection terminals of the substrate with the corresponding interlayer connection terminals formed on the support, bonding them with an adhesive, and electrically connecting the interlayer connection terminals. . 5d. Removing and removing the support. 5e. Forming a wiring on the surface from which the support has been peeled off;

As the adhesive, an anisotropic conductive adhesive in which conductive particles of 0.05 to 30 vol% are dispersed can be used.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, when wiring is formed on a wiring substrate serving as a base by a build-up method, a wiring board on a base substrate side, a build-up wiring formed on an upper layer thereof, and a support for the wiring board are formed. The layers are positioned so that they face each other, and the layers are integrated through an adhesive. At this time, of the terminals for making a predetermined connection provided on both wiring layers, the connection terminal is formed higher than the wiring of the same layer in at least one of the wiring layers, so that the insulation between the wirings is improved. , Electrical connection can be obtained only between the connection terminals, and the build-up system can be multilayered. The connection terminal may be higher than the wiring on either the base substrate side or the build-up side provided on the support, or both. Alternatively, as a method of forming the connection terminal and the build-up wiring in two steps, only the connection terminal is formed on the support, and the terminal is connected to the terminal on the surface after lamination integration and removal of the support. A predetermined wiring may be formed.

[0012] The multilayer wiring board obtained by the first, second or third manufacturing method is connected to each of the first, second or third manufacturing method by 3a,
By performing the steps 3b, 4b, and 5b and below, it is possible to obtain a multi-layer wiring board having a plurality of connection layers via an adhesive by performing the steps 3b, 4b, and 5b and below.

Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 3 shows a method of forming a build-up wiring using an adhesive on a base substrate on which wiring and connection terminals are formed. FIG. 3A is a diagram in which wiring 2 and connection terminals 3 are formed on a base substrate 1. FIG. 3B shows a plating resist 4 formed on a base substrate so that only the connection terminal portions are exposed. FIG. 3 (c) shows that the metal plating 5 is applied to the opening of the plating resist so that at least all the connection terminals are higher than the wiring, taking into account the variation in wiring height, and the plating resist is peeled off. FIG. Metal plating 5 is made of Cu, N
A metal having excellent conductivity such as i, Au, and Ag is desirable.
Also, a plurality of metals such as Cu / Ni / Au are combined,
It may be formed in a multilayer structure. FIG. 3D shows that the adhesive 6 is disposed on the base substrate, and the conductor support 7 is further provided in advance.
FIG. 4 is a schematic diagram showing a state in which a build-up wiring 8 and a build-up side connection terminal 9 formed above are opposed to the wiring of the base substrate and are positioned and arranged so as to perform a predetermined connection.

The adhesive may be in the form of a film or a liquid, but the film can be put into the bonding step simply by arranging it instead of being formed on the substrate by coating or printing as in the case of a liquid. This is preferable because not only is it easy to handle, but it is easy to control the film thickness in consideration of the height of the connection terminal. As the adhesive, a thermoplastic polymer or a crosslinked polymer that is cured by energy such as heat, an electron beam, or light is used. Among these, a crosslinked polymer is preferable from the viewpoint of heat resistance, adhesiveness, and moisture resistance, and an epoxy resin, a cyanate ester resin, and an imide resin are particularly preferable. In addition, a thermoplastic polymer can be mixed with these resins for the purpose of imparting flexibility and film formability. Since the bonding is performed by heating and pressurizing, if the melt viscosity of the adhesive at the time of heating is too high, the adhesive is not removed from between the connection terminals and electrical conduction cannot be secured. The melt viscosity is preferably set to 1000 poise or less.

In the adhesive of the present invention, conductive particles can be dispersed for the purpose of positively imparting anisotropic conductivity in order to absorb height variations of the connection terminal electrodes. Hereinafter, this is referred to as an anisotropic conductive adhesive. In the present invention, the conductive particles are, for example, metal particles such as Au, Ni, Cu, W or solder, or metal particles formed by plating or vapor-depositing a thin film such as gold or palladium on the surface of these metal particles,
Ni, Cu, Spherical core material of polymer such as polystyrene
Conductive particles provided with a conductive layer such as Au or solder can be used. The particle size must be smaller than the minimum distance between the electrodes on the substrate, and if there is a variation in the height of the electrodes,
It is preferable that the height is larger than the height variation.
0 μm is preferred. The amount of the conductive particles dispersed in the adhesive is 0.05 to 30% by volume, preferably 0.2 to 30% by volume.
~ 15% by volume.

FIG. 3 (e) shows that the positioned base substrate, adhesive and build-up wiring and its support are heated,
FIG. 3 is a diagram in which pressure is applied to perform lamination integration, and FIG.
(F) is a diagram in which the support of the build-up wiring is separated and removed from the laminated and integrated substrate. The conductor support 8 for holding the build-up wiring is made of a rigid plate or a film having a rigid property, and the peeling and removal after bonding and fixing is performed by a mechanical peeling method, or by chemically peeling or dissolving and removing. There is a way to do that. Since the connection terminal is higher than the wiring, insulation between the wirings in the in-plane direction and also in the height direction is ensured.

FIG. 4A shows a film-like anisotropic conductive adhesive 11 in which conductive particles 10 are dispersed in an adhesive.
FIG. 4B shows a multilayer wiring board obtained when this anisotropic conductive adhesive is used as the adhesive in the above description. Further, as shown in FIG. 4 (a), the anisotropic conductive adhesive is used to improve the filling property of the adhesive around the wiring and the connection terminals, so that the conductive particle-dispersed layer 11 containing conductive particles can be used.
a and a conductive particle non-dispersion layer 11b made of an insulating material. FIG. 5 (b) is a schematic diagram after fixing and bonding when an organic anisotropic conductive adhesive having a two-layer structure is used.
Shown in

FIG. 6 shows that the wiring on the base substrate and the connection terminals are formed at the same height, and the connection terminals on the support for forming the build-up wiring are higher than the wirings, so that the electrical connection between the layers is achieved. Here is how to get FIG. 6A shows a state in which a plating resist is formed on the support 7 of the build-up wiring 8 so that the connection terminals 9 are exposed, the metal plating 5 is applied, and the resist is peeled off. In FIG. 6B, the base substrate 1 on which the wiring 2 and the connection terminal 3 are formed in advance, and the conductor support on which the build-up wiring and the connection terminal are formed by the above-described method, are placed between an anisotropic conductive adhesive 11. FIG. 6 is a diagram in which conductors are separated and removed after positioning and lamination and integration so that wirings are opposed to each other and a predetermined connection can be performed.

FIG. 7 shows a multi-layer wiring board having one build-up wiring layer obtained by using the anisotropic conductive adhesive shown in FIG. 6 as a base substrate, and then the connection method shown in FIG. 6 again. FIG. 3 is a diagram in which a two-layer build-up wiring is formed by using the same. The interlayer via formed by the manufacturing method of the present invention can be formed immediately above the via in the lower layer or at any other location. By repeating the interlayer connection method via the adhesive as described above, a desired number of layers of build-up wiring can be formed. FIG. 8 shows a multi-layer wiring board 12 having an inner layer circuit 13 on a base board and through-hole connection 102, using the method shown in FIG. 3 and using an anisotropic conductive adhesive as an adhesive. 2 shows a multilayer wiring board having build-up wiring layers formed on both sides of the board.

FIG. 9 shows a structure obtained by using the conductor support on which the wiring and connection terminals are formed as a base substrate and using an anisotropic conductive adhesive as the adhesive in the method shown in FIG. 3 shows a layer wiring board.

[0021]

【Example】

Example 1 A multilayer wiring board including one build-up wiring layer shown in FIG. 10 was manufactured by the method shown in FIG. A double-sided wiring board 12 produced was used as a base substrate by performing through-hole drilling, through-hole plating, and wiring formation on a copper-clad laminate having a thickness of 0.2 mm using a glass cloth epoxy resin base material. A photoresist film having a thickness of 40 μm was laminated on both surfaces of the base substrate, and an opening having a diameter of 100 μm was formed in the resist film through a predetermined exposure and development process so as to expose only the terminal portion for interlayer connection on the build-up side. Next, a projection of about 30 μm was formed on the terminal portion by electrolytic Cu plating, electrolytic Ni plating was applied to a thickness of about 5 μm, and electrolytic Au plating was applied to a thickness of 0.5 μm, and then the resist film was peeled off. On the base wiring board thus obtained,
An adhesive film 6 (melt viscosity at 180 ° C .: 200 poises) mainly composed of a high-molecular-weight epoxy resin having a thickness of 40 μm was temporarily bonded at a temperature of 100 ° C., a pressure of 5 kg / cm ² , and a pressing time of 5 seconds. On the other hand, a photoresist film was laminated on a SUS plate having a thickness of 0.5 mm used as a conductor support and exposed using a photomask, and then a predetermined build-up wiring portion was exposed through a developing process. Next, electrolytic Cu plating was performed so that the average thickness became about 25 μm, and then the resist film was peeled off to form build-up wiring and connection terminals. The surface of the plated wiring was subjected to an oxidation treatment (blackening treatment) and then a reduction treatment in order to improve the adhesion to the anisotropic conductive adhesive film. Note that the surface of the SUS plate was appropriately roughened with abrasive paper in advance so that the resist film did not peel off from the SUS plate during electrolytic plating. S with built-up wiring thus obtained
The US plate is positioned in a direction in which the wiring is in contact with the adhesive film 6 of the base substrate, and is positioned with fixing pins.
The adhesive was fixed under the condition of a pressure of 30 kgf / cm ² . next,
Only the SUS plate was mechanically peeled off to obtain a product.

Example 2 A multilayer wiring board including one build-up wiring shown in FIG. 11 was manufactured by the following method. In the same manner as described in Example 1, a base substrate wiring 12 having a projection formed on the connection terminal portion was obtained. An adhesive film 11 (40 μm in thickness, 18 μm in thickness) composed mainly of a high molecular weight epoxy resin in which 5 vol% of conductive particles in which an Au layer 10 a is formed on the surface of a polystyrene core (diameter: 5 μm) 10 b is dispersed at 5 vol%.
The melt viscosity at 0 ° C .: 210 poise) was temporarily bonded at a temperature of 100 ° C., a pressure of 5 kg / cm ² , and a pressing time of 5 seconds.
Further, build-up wiring and connection terminals were formed on the SUS plate in the same manner as in Example 1, and the wiring was positioned in the direction in which the wiring was in contact with the anisotropic conductive film of the base substrate and with the fixing pins. The substrate was bonded and fixed at a temperature of 30 ° C. and a pressure of 30 kgf / cm ² . Next, only the SUS plate was mechanically peeled off to obtain a product.

Example 3 A multilayer wiring board including one layer of build-up wiring shown in FIG. 12 was manufactured by the following method. In the same manner as described in Example 1, a base substrate wiring 12 having a projection formed on the connection terminal portion was obtained. An adhesive film 11 (40 μm thick) mainly composed of a high-molecular-weight epoxy resin in which 2 vol% of nickel particles (diameter: 5 μm) 10c are dispersed on the base wiring board is provided.
m, melt viscosity at 180 ° C .: 220 poise) at a temperature of 10
Temporary bonding was performed under the conditions of 0 ° C., a pressure of 5 kg / cm ² , and a pressing time of 5 seconds. Further, build-up wiring and connection terminals were formed on the SUS plate in the same manner as in Example 1, and the wiring was positioned in the direction in which the wiring was in contact with the anisotropic conductive film of the base substrate and with the fixing pins. ° C, pressure 30kgf /
It was bonded and fixed to the base wiring substrate under the condition of cm ² . next,
Only the SUS plate was mechanically peeled off to obtain a product.

[0024]

As described above, according to the multilayer wiring board of the present invention, the following advantages are achieved. (1) Electrical interlayer connection is possible without forming a through hole. (2) Through-hole lands are unnecessary, and via holes formed by the build-up method can be stacked directly above, so that the wiring density can be improved. (3) Since the surface of the connection via is flat, it can be used as a surface mounting terminal.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a conventional through-hole connection type multilayer wiring board.

FIG. 2 is a cross-sectional view of a conventional build-up type multilayer wiring board by a photo method.

FIG. 3 is a cross-sectional view illustrating a manufacturing process of the multilayer wiring board of the present invention.

FIG. 4 is a sectional view of a multilayer wiring board using the anisotropic conductive adhesive of the present invention.

FIG. 5 is a sectional view of a multilayer wiring board using the two-layer anisotropic conductive adhesive of the present invention.

FIG. 6 is a cross-sectional view illustrating a manufacturing process of the multilayer wiring board of the present invention.

FIG. 7 is a sectional view of a multilayer wiring board using the anisotropic conductive adhesive of the present invention.

FIG. 8 is a sectional view of a multilayer wiring board using the anisotropic conductive adhesive of the present invention.

FIG. 9 is a sectional view of a multilayer wiring board using the anisotropic conductive adhesive of the present invention.

FIG. 10 is a sectional view of the multilayer wiring board according to the first embodiment.

FIG. 11 is a sectional view of a multilayer wiring board according to a second embodiment.

FIG. 12 is a sectional view of a multilayer wiring board according to a third embodiment.

[Explanation of symbols]

 1 base board 2 wiring 3 connection terminals 4 plating resist 5 metal plating 6 adhesive 7 conductor support 8 build-up wiring 9 Terminal for build-up side connection 10 Conductive particle 10a Au layer 10b Polystyrene core 10c Nickel particle 11 Anisotropic conductive adhesive 11a Conductive particle dispersion layer 11b No conductive particle dispersion Layer 12 Multi-layer wiring board with through-hole connection 13 Inner layer circuit 101 Non-through-hole 102 102 Through-hole 103 Via hole 104 Build-up wiring

Claims (7)

[Claims] 1. A substrate on which a wiring and an interlayer connection terminal having a height higher than the wiring are formed, and a conductor layer on which the interlayer connection terminal and the wiring corresponding to the interlayer connection terminal of the substrate are formed. The terminal for interlayer connection of the substrate and the terminal for interlayer connection of the conductor layer are laminated and integrated via an adhesive so as to face each other, and the terminals for interlayer connection are electrically connected. Characteristic multilayer wiring board. 2. A conductor layer on which a wiring and an interlayer connection terminal having a height higher than the wiring are formed, and a substrate on which the interlayer connection terminal and the wiring corresponding to the interlayer connection terminal of the conductor layer are formed. Are laminated and integrated via an adhesive with the interlayer connection terminal of the conductor layer facing the interlayer connection terminal of the substrate and electrically connecting the interlayer connection terminals. A multilayer wiring board characterized by the above-mentioned. 3. A method for manufacturing a multilayer wiring board, comprising the following steps 3a to 3e. 3a. A step of preparing a substrate on which wiring and interlayer connection terminals are formed; 3b. Forming an interlayer connection terminal and a wiring corresponding to the interlayer connection terminal of the substrate on a support. 3c. Forming an interlayer connection terminal of the substrate higher than a wiring in the same plane; 3d. A step of aligning the interlayer connection terminals of the substrate with the corresponding interlayer connection terminals formed on the support, bonding them with an adhesive, and electrically connecting the interlayer connection terminals. . 3e. Removing and removing the support. 4. A method for manufacturing a multilayer wiring board, comprising the following steps 4a to 4e. 4a. A step of preparing a substrate on which wiring and interlayer connection terminals are formed; 4b. Forming an interlayer connection terminal and a wiring corresponding to the interlayer connection terminal of the substrate on a support. 4c. Forming an interlayer connection terminal formed on the support above a wiring in the same plane; 4d. A step of aligning the interlayer connection terminals of the substrate with the corresponding interlayer connection terminals formed on the support, bonding them with an adhesive, and electrically connecting the interlayer connection terminals. . 4e. Removing and removing the support. 5. A method for manufacturing a multilayer wiring board, comprising the following steps 5a to 5e. 5a. A step of preparing a substrate on which wiring and interlayer connection terminals are formed; 5b. Forming on the support a terminal for interlayer connection corresponding to the terminal for interlayer connection of the substrate 5c. A step of aligning the interlayer connection terminals of the substrate with the corresponding interlayer connection terminals formed on the support, bonding them with an adhesive, and electrically connecting the interlayer connection terminals. . 5d. Removing and removing the support. 5e. Forming a wiring on the surface from which the support has been peeled off; 6. The adhesive according to claim 1, wherein the adhesive is an anisotropic conductive adhesive in which conductive particles of 0.05 to 30 vol% are dispersed.
Or the multilayer wiring board according to 2. 7. The adhesive according to claim 3, wherein the adhesive is an anisotropic conductive adhesive in which conductive particles of 0.05 to 30 vol% are dispersed.
Item 5. The method for manufacturing a multilayer wiring board according to any one of Items 5 to 5.