JPH10322026A - Multilayered wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To specify the electric resistance value of thin film wiring conductor layers with a preferred resistance value, and also provide organic resin insulating layers interposing the thin film wiring conductor with the film junction having high reliability, by a method wherein the thickness of the thin film wiring conductor layers arranged between the organic resin insulating layers is specified to be within a specific range. SOLUTION: The thickness of respective thin film wiring conductor layers 3 when assumed not to exceed 3 μm is affected by the surface state of the organic resin insulating layers 2 to be notably dispersed. Resultantly, it becomes difficult to specify the electric resistance value of the thin film wiring conductor layers 3. Besides, when the organic resin insulating layers 2 to be arranged on the upper part are laminated in order to form the next organic resin insulating layer 2 on the organic resin insulating layer 2 whereon the thin film wiring conductor layer 3 in the thickness exceeding 10 μm is formed, a lot of air existent on the side face of the thin film wiring conductor layers 3 is adsorbed into the organic resin insulating layers 2 arranged on the upper part. Accordingly, it is mandatory to specify the thickness of the thin film wiring conductor layers 3 to be within the range of 3 μm-10 μm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multilayer wiring board, and more particularly to a multilayer wiring board used for a hybrid integrated circuit device, a semiconductor element housing package for housing a semiconductor element, and the like.

[0002]

2. Description of the Related Art Hitherto, a multilayer wiring board used in a hybrid integrated circuit device, a package for accommodating a semiconductor element, or the like, has its wiring conductor formed by a thick film forming technique such as the Mo-Mn method.

[0003] This Mo-Mn method is generally used for tungsten,
Organic solvents for high melting point metal powders such as molybdenum and manganese,
A solvent is added and mixed, and a paste-like metal paste is applied by printing on the outer surface of the green ceramic body in a predetermined pattern by a screen printing method. Then, a plurality of these layers are laminated and fired in a reducing atmosphere to obtain a high melting point. This is a method of sintering and integrating a metal powder and a green ceramic body.

The ceramic body on which the wiring conductor is formed is usually an oxide ceramic such as an aluminum oxide sintered body or a mullite sintered body, or an aluminum nitride having an oxide film deposited on the surface. Non-oxide ceramics such as a porous sintered body and a silicon carbide sintered body are used.

However, when the wiring conductor is formed by using the Mo-Mn method, the wiring conductor is formed by screen-printing a metal paste. Had the drawback that it could not be done.

In order to solve the above-mentioned drawbacks, the present applicant has previously disclosed in Japanese Patent Application No. 8-94433 a thin-film forming technique capable of miniaturization instead of forming a wiring conductor by a conventional thick-film forming technique. We proposed a multilayer wiring board formed with high density.

Such a multilayer wiring board is formed by spin coating an upper surface of an insulating substrate made of a glass epoxy resin or the like formed by impregnating a glass cloth woven with ceramics or glass fibers made of an aluminum oxide sintered body or the like with an epoxy resin. Adopt an organic resin insulating layer of 5 μm to 100 μm in thickness made of epoxy resin formed by a method and a thermosetting treatment, and a thin film forming technique such as a plating method and a vapor deposition method of a metal such as copper and aluminum, and a photolithography technique. A thin film wiring conductor layer having a thickness of 1 μm to 40 μm is alternately laminated in multiple layers, and a thin film wiring conductor layer positioned above and below is attached to the inner wall of a through hole provided in the organic resin insulating layer. It has a structure electrically connected via a hole conductor.

In this multi-layer wiring board, the through holes formed in each organic resin insulating layer employ photolithography technology. Specifically, first, a resist material is applied on the organic resin insulating layer. Along with this, exposure and development are performed to form a window of a predetermined shape at a predetermined position, and then an etchant is disposed on the window of the resist material, and an organic resin insulating layer located on the window of the resist material is formed. Remove and make holes (through holes) in the organic resin insulation layer
Is formed, and finally the above-mentioned Gilest material is peeled off from the organic resin insulating layer and removed.

[0009]

In the above-mentioned multilayer wiring board, the electric resistance of the thin film wiring conductor layer is reduced so that electric signals can be transmitted well through the thin film wiring conductor layer and the thin film wiring conductor layer is formed. The thickness of the thin-film wiring conductor layer is in the range of 1 μm to 40 μm in order to reduce the stress generated during the bonding and to strengthen the bonding between the organic resin insulating layer and the thin-film wiring conductor layer.

However, the thickness of the thin-film wiring conductor layer is 3
If the thickness is less than μm, the thickness of the thin-film wiring conductor layer greatly varies under the influence of the surface condition of the upper surface of the organic resin insulating layer. As a result, it is difficult to control the electric resistance of the thin-film wiring conductor layer to a desired value. And 10μ
When the thickness exceeds m, when the next organic resin insulating layer is formed on the organic resin insulating layer on which the thin film wiring conductor layer is formed on the upper surface, the organic resin insulating layer disposed on the upper side is formed on the side surface of the thin film wiring conductor layer Embraces the air that exists in
The problem to be solved is that the bonding strength of the organic resin insulating layers located above and below is reduced, and the reliability as a multilayer wiring board is deteriorated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned drawbacks, and has as its object to provide a thin-film wiring conductor layer having a desired electric resistance value and a reliable connection between organic resin insulating layers located above and below. To provide a multi-layer wiring board with high performance.

[0012]

According to the present invention, an organic resin insulating layer and a thin film wiring conductor layer are alternately laminated on a substrate, and thin film wiring conductor layers positioned above and below are provided on each organic resin insulation layer. A multilayer wiring board connected via a through-hole conductor attached to an inner wall of a through-hole, wherein a thickness of a thin-film wiring conductor layer disposed between the organic resin insulating layers is 3 μm to 10 μm. It is a feature.

According to the multilayer wiring board of the present invention, since the wiring is formed on the substrate by the thin film forming technique, the wiring can be miniaturized, and the wiring can be formed at an extremely high density.

Further, according to the multilayer wiring board of the present invention, since the thickness of the thin-film wiring conductor layer is set to 3 μm to 10 μm, the thin-film wiring conductor layer is not largely affected by the surface condition of the upper surface of the organic resin insulating layer and is substantially not affected. It is possible to make the electric resistance value of the thin film wiring conductor layer a predetermined value, and to form the next organic resin insulation layer on the organic resin insulation layer on which the thin film wiring conductor layer is formed. At the time of lamination formation, the organic resin insulating layer disposed on the upper side embraces a large amount of air existing on the side surface of the thin film wiring conductor layer, and the bonding strength of the organic resin insulating layer positioned above and below is largely reduced in most cases. However, this makes it possible to increase the reliability of the multilayer wiring board.

[0015]

Next, the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 shows an embodiment of the multilayer wiring board of the present invention, wherein 1 is an insulating substrate, 2 is an organic resin insulating layer,
3 is a thin film wiring conductor.

The substrate 1 has an organic resin insulating layer 2 on its upper surface.
And a thin-film wiring conductor 3, which serves as a support member for supporting the multi-layer wiring portion 4.

The substrate 1 is made of an oxide ceramic such as an aluminum oxide sintered body or a mullite sintered body, or a non-conductive body such as an aluminum nitride sintered body or a silicon carbide sintered body having an oxide film on the surface. Oxide ceramics, and further made of an electrically insulating material such as glass epoxy resin impregnated with epoxy resin in a cloth woven with glass fiber, for example, when formed of aluminum oxide sintered body , Alumina, silica, calcia, magnesia, etc., an appropriate organic solvent and a solvent are added and mixed to form a slurry, and the ceramic green sheet is formed by employing a conventionally known doctor blade method or calendar roll method. Ceramic green sheet), and after that, the ceramic green sheet is subjected to an appropriate punching process to obtain a predetermined shape. Hot together form (about 1600
C) or by mixing a raw material powder such as alumina with an appropriate organic solvent and solvent to adjust the raw material powder and form the raw material powder into a predetermined shape by a press molding machine. If the body is made by firing the body at a temperature of about 1600 ° C. and is made of glass epoxy resin, for example, a cloth woven with glass fiber is impregnated with the epoxy resin precursor and the epoxy resin precursor is heated to a predetermined temperature. It is manufactured by heat curing.

The substrate 1 is formed with a through hole 5 having a diameter of, for example, 0.3 mm to 0.5 mm, which penetrates the upper and lower surfaces of the substrate 1. Conductive layers 6 leading to both sides are applied.

The through hole 5 electrically connects the thin-film wiring conductor layer 3 of the multilayer wiring portion 4 formed on the upper surface of the substrate 1 and an external electric circuit to be described later, or the multilayer wiring portion is formed on both upper and lower surfaces of the substrate 1. When the substrate 4 is formed, it acts as a forming hole for forming a conductive layer 6 for electrically connecting the thin film wiring conductor layers 3 of the multilayer wiring portion 4 on both surfaces, and the substrate 1 is subjected to a drilling method. Thus, a predetermined shape is formed at a predetermined position on the substrate 1.

Further, a conductive layer 6 is formed on the inner wall of the through hole 5 and the upper and lower surfaces of the substrate 1, and the conductive layer 6 is made of a metal material such as copper or nickel. By adopting the method and the etching technique, it is adhered to the inner wall of the through hole 5 with both ends being led out to the upper and lower surfaces of the substrate 1.

The conductive layer 6 is used to electrically connect the thin-film wiring conductor layer 3 of the multilayer wiring portion 4 formed on the upper surface of the substrate 1 to an external electric circuit, or to form each of the multilayers formed on the upper and lower surfaces of the substrate 1. It functions to electrically connect the thin film wiring conductor layers 3 of the wiring portion 4 to each other.

The through hole 5 formed in the substrate 1 is filled with an organic resin filler 7 made of epoxy resin or the like. The through hole 5 is completely filled with the organic resin filler 7, and Both end surfaces of the organic resin filler 7 are flush with the surface of the conductive layer 6 attached to the upper and lower surfaces of the substrate 1.

The organic resin filler 7 is used to form a multilayer wiring portion 4 composed of an organic resin insulating layer 2 and a thin film wiring conductor layer 3 described later on the upper surface and / or lower surface of the substrate 1. It functions to maintain the flatness of the resin insulating layer 2 and the thin film wiring conductor layer 3.

The organic resin filler 7 fills the through hole 5 of the substrate 1 with a precursor such as an epoxy resin, and then is applied with a temperature of 80 to 200 ° C. for 0.5 to 3 hours. Is completely cured by heat so that the through holes 5 of the substrate 1 are formed.
Is filled in.

Further, the substrate 1 is provided on its upper surface with a multilayer wiring portion 4 in which an organic resin clear layer 2 and a thin film wiring conductor layer 3 are alternately laminated in multiple layers. The part is electrically connected to the conductive layer 6.

The organic resin insulating layer 2 constituting the multi-layer wiring section 4 functions to electrically insulate the thin film wiring conductor layer 3 located above and below, and the thin film wiring conductor layer 3 is used for transmitting electric signals. Acts as a road.

The organic resin insulating layer 2 of the multilayer wiring section 4 is made of an epoxy resin. For example, bisphenol A type epoxy resin, novolak type epoxy resin, glycidyl ester type epoxy resin, etc. A curing agent such as an acid anhydride-based curing agent is added and mixed to obtain a paste-like epoxy resin precursor, and the epoxy resin precursor is applied to the upper portion of the substrate 1 by a spin coating method. It is formed by heat-treating with heat of 80 ° C. to 200 ° C. for 0.5 to 3 hours and heat curing.

The organic resin insulating layer 2 has a through hole 8 at a predetermined position, the minimum diameter of which is about 1.5 times the thickness of the organic resin insulating layer 2. Serves as a forming hole for forming a through-hole conductor 9 for electrically connecting each of the thin film wiring conductor layers 3 positioned above and below the organic resin insulating layer 2 described later.

The through hole 8 provided in the organic resin insulating layer 2 is formed at a predetermined position by, for example, photolithography, specifically, by applying a resist material on the organic resin insulating layer 2 and exposing and developing the resist material. Then, a window having a predetermined shape is formed, and then an etchant is disposed on the window of the resist material, the organic resin insulating layer 2 located on the window of the resist material is removed, and a hole is formed in the organic resin insulating layer 2. (Through holes), and finally, the resist material is peeled off from the organic resin insulating layer 2 and removed.

Further, a thin-film wiring conductor layer 3 having a predetermined pattern is provided on the upper surface of each organic resin insulating layer 2, and a through-hole conductor 9 is provided on an inner wall of a through hole 8 provided in each organic resin insulating layer 2. Each of the thin-film wiring conductor layers 3 located above and below the organic resin insulating layer 2 with the through-hole conductor 9 therebetween is electrically connected.

The thin-film wiring conductor layer 3 and the through-hole conductor 9 provided in the upper surface of each of the organic resin insulating layers 2 and in the through-holes 8 are made of a metal material such as copper, nickel, gold, or aluminum by electroless plating. It is formed by employing a thin film forming technique such as a vapor deposition method and a sputtering method and an etching processing technique.
0.06 mol / l of copper sulfate, 0.3 mol / l of formalin, 0.35 mol / l of sodium hydroxide, 0.35 mol / l of ethylenediaminetetraacetic acid are formed on the upper surface of the organic resin insulating layer 2 and the inner wall surface of the through hole 8. 1 µm to 40 µm using a 1 liter electroless copper plating bath
m, and thereafter, the copper layer is processed into a predetermined pattern by employing an etching technique, thereby forming an inner wall between the organic resin insulating layers 2 and between the organic resin insulating layers 2. It is arranged in. In this case, since the thin-film wiring conductor layer 3 is formed by a thin-film forming technique, the wiring can be miniaturized, thereby making it possible to form the thin-film wiring conductor layer 3 at an extremely high density.

When the thickness of each organic resin insulating layer 2 exceeds 100 μm, the multi-layer wiring portion 4 employs photolithography technology in the organic resin insulating layer 2 to form a through hole 8, so that the etching processing time is reduced. When the length is longer, it is difficult to form the through hole 8 into a desired sharp shape. When the thickness is less than 5 μm, the roughness for increasing the bonding strength of the organic resin insulating layer 2 located above and below the upper surface of the organic resin insulating layer 2 is increased. When performing surface processing, there is a risk that unnecessary holes may be formed in the organic resin insulating layer 2 and unnecessary electrical short circuits may occur in the thin film wiring conductor layers 3 located above and below. Therefore,
The organic resin insulating layer 2 has a thickness of 5 μm to 1 μm.
It is preferable that the thickness be in the range of 00 μm.

If the thickness of each thin-film wiring conductor layer 3 of the multilayer wiring portion 4 is less than 3 μm, the thickness of the thin-film wiring conductor layer 3 is greatly varied under the influence of the surface condition of the upper surface of the organic resin insulating layer 2. As a result, it is difficult to set the electric resistance value of the thin film wiring conductor layer 3 to a desired value, and
Is exceeded, when the next organic resin insulating layer 2 is laminated on the organic resin insulating layer 2 on which the thin film wiring conductor layer 3 is formed on the upper surface, the organic resin insulating layer 2 disposed above is 3 embraces a large amount of air existing on the side surface, and as a result, the bonding strength of the organic resin insulating layers 2 located above and below is reduced, and the reliability as a multilayer wiring board is deteriorated. Therefore, each thin-film wiring conductor 3 of the multilayer wiring portion 4
In order to increase the reliability of the multilayer wiring board by setting the thin film wiring conductor layer 3 to a small predetermined value at which electric signals can be transmitted satisfactorily and making the bonding between the organic resin insulating layers located above and below strong, Must be in the range of 3 μm to 10 μm.

The multilayer wiring portion 4 formed by alternately laminating the organic resin insulating layer 2 and the thin film wiring conductor layer 3 in a multilayer structure has a through hole 5 formed in the substrate 1 completely filled with an organic resin filler 7. Even when the organic resin insulating layer 2 is formed on the upper surface of the substrate 1, the organic resin insulating layer 2 is kept flat, and the thin film wiring conductor formed on each organic resin insulating layer 2 is formed. It is possible to effectively prevent occurrence of disconnection or the like in the layer 3.

Thus, according to the multilayer wiring board of the present invention,
Active components such as semiconductor elements and passive components such as capacitors and resistors are mounted on the multilayer wiring portion 4 attached to the upper surface of the substrate 1 to form a semiconductor device or a hybrid integrated circuit device. If the applied conductive layer 6 is connected to an external electric circuit, the semiconductor device or the hybrid integrated circuit device will be electrically connected to the external electric circuit.

It should be noted that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the present invention. The multi-layer wiring section 4 composed of the organic resin insulating layer 2 and the thin film wiring conductor 3 is provided only on the upper surface.
May be provided only on the lower surface side of the substrate 1 or on both upper and lower surfaces.

[0037]

According to the multilayer wiring board of the present invention, since the wiring is formed on the substrate by the thin film forming technique, the wiring can be miniaturized and the wiring can be formed at an extremely high density.

Further, according to the multilayer wiring board of the present invention, since the thickness of the thin film wiring conductor layer is 3 μm to 10 μm, the thin film wiring conductor layer is not greatly affected by the surface condition of the upper surface of the organic resin insulating layer. The electric resistance of the thin-film wiring conductor layer can be made a predetermined value, and the next organic resin insulation layer can be formed on the organic resin insulation layer on which the thin-film wiring conductor layer is formed. When laminating, the organic resin insulating layer disposed on the upper part embraces a large amount of air existing on the side surface of the thin film wiring conductor layer, and the bonding strength of the organic resin insulating layer located above and below may be greatly reduced. Almost no, so that the reliability as a multilayer wiring board can be increased.

[Brief description of the drawings]

FIG. 1 is a sectional view showing one embodiment of a multilayer wiring board of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Substrate 2 ... Organic resin insulating layer 3 ... Thin film wiring conductor 4 ... Multilayer wiring part 8 ... Through hole 9 ... Through hole conductor

Claims (1)

[Claims] An organic resin insulating layer and a thin film wiring conductor layer are alternately laminated on a substrate, and thin film wiring conductor layers located above and below are adhered to inner walls of through holes provided in each organic resin insulation layer. A multilayer wiring board connected via a through-hole conductor, wherein a thickness of a thin-film wiring conductor layer disposed between the organic resin insulating layers is 3 μm to 10 μm.