JPH10322019A - Multilayered wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid the release of thin film wiring insulating layers from organic resin insulating layers, by a method wherein the organic resin insulating layers and the thin film wiring conductor layers formed of through holes are alternately laminated so that the thin film wiring conductor layers may be wrapped around upper and lower organic resin insulating layers to be firmly fixed. SOLUTION: Organic resin insulating layers 2 made of epoxy resin, etc., and thin film wiring conductor layers 3 are alternately laminated in multilayers to form a multilayered wiring part 4 on the surface of a substrate 1 made of oxide base ceramics, etc.. In such a constitution, throughholes 10 in aperture diameter of 0.02-1.0 mm are formed so that the parts of the organic resin insulating layer 2 positioned on the above part may extend into the through holes 10 to he integrated with the lower organic resin insulating layers 2, thereby enabling the thin film wiring conductor layers 3 to be firmly junctioned by completely wrapping around the organic resin insulating layers 2. Through these procedures, the thin film wiring conductor layers 3 will not be released from the organic resin insulating layers 2.

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, a multilayer wiring board formed at a high density by using a thin film forming technique capable of miniaturization instead of forming a wiring conductor by a conventional thick film forming technique is employed. It has become.

Such a multilayer wiring board is composed of an insulating substrate made of glass epoxy resin or the like formed by impregnating a ceramic or glass fiber woven fabric made of aluminum oxide sintered body or the like with an epoxy resin, and an insulating substrate made of the same. By adopting an organic resin insulation layer made of epoxy resin formed on the upper surface by spin coating and thermosetting, and metal such as copper and aluminum by using thin film forming technology such as plating and vapor deposition and photolithography technology The thin-film wiring conductor layers to be formed are alternately laminated in multiple layers, and the upper and lower thin-film wiring conductor layers are electrically connected via the through-hole conductors attached to the inner walls of the through-holes provided in the organic resin insulating layer. It has a connected structure.

In this multilayer wiring board, the through holes formed in each organic resin insulating layer employ photolithography technology. Specifically, first, a resist material is applied onto the organic resin insulating layer. Exposure and development are performed on this 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 to remove the organic resin insulating layer located on the window of the resist material. Then, a hole (through hole) is formed in the organic resin insulating layer, and finally, the above-mentioned girest material is peeled off from the organic resin insulating layer and removed.

[0009]

However, this multilayer wiring board has poor adhesion between an organic resin insulating layer made of an epoxy resin or the like and a thin film wiring conductor layer made of a metal material such as copper or aluminum. When an external force is applied to the layer or the thin-film wiring conductor layer, the external force easily causes peeling between the organic resin insulating layer and the thin-film wiring conductor layer, thereby deteriorating the reliability as a multilayer wiring board. Provoked. In particular, the above-mentioned drawbacks become remarkable in recent multilayer wiring boards in which a thin-film wiring conductor layer is formed at a high density between organic resin insulating layers, and it is required to miniaturize and form a wiring at an extremely high density. Have been.

The present invention has been devised in view of the above-mentioned drawbacks, and has as its object to provide a highly reliable multilayer wiring board in which an organic resin insulating layer and a thin-film wiring conductor layer are firmly joined. .

[0011]

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 the through-hole, wherein a through-hole is formed in a thin-film wiring conductor layer disposed between the organic resin insulating layers. Is what you do.

Further, the present invention is characterized in that an opening diameter of the through hole formed in the thin film wiring conductor layer is set to 0.02 mm to 1.0 mm.

According to the multilayer wiring board of the present invention, the organic resin insulating layers and the thin film wiring conductor layers are alternately laminated, and the thin film wiring conductor layer arranged between the organic resin insulating layers has, for example, an opening diameter of 0.1 mm. Since the through-holes of 02 mm to 1.0 mm were formed, the organic resin insulating layers located above and below the thin-film wiring conductor layer were integrated with each other through the through-holes provided in the thin-film wiring conductor layer. However, the thin-film wiring conductor layer is completely wrapped by the organic resin insulating layers located above and below and is firmly fixed, and even if an external force is applied, separation between the organic resin insulating layer and the thin-film wiring conductor layer does not occur. Absent.

Further, according to 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.

[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 layer.

The substrate 1 has an organic resin insulating layer 2 on its upper surface.
And a thin-film wiring conductor layer 3, and a multilayer wiring portion 4 is provided, and functions as a support member for supporting the multilayer 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, on the upper surface of the substrate 1, a multilayer wiring portion 4 in which an organic resin insulating layer 2 and a thin film wiring conductor layer 3 are alternately laminated in a multilayer is formed, and a part of the thin film wiring conductor layer 3 is formed. 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.

The multilayer wiring portion 4 formed by alternately laminating the organic resin insulating layer 2 and the thin film wiring conductor layer 3 in multiple layers has a through hole 5 provided 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.

When the thickness of each organic resin insulating layer 2 exceeds 100 μm, the multilayer wiring portion 4 employs photolithography technology in the organic resin insulating layer 2 to form a through-hole 8 by using etching time. Becomes longer, making it difficult to form the through hole 8 into a desired sharp shape. If the thickness is less than 5 μm, the bonding strength of the organic resin insulating layer 2 located above and below the organic resin insulating layer 2 is increased. When roughening is performed, there is a risk that unnecessary holes are formed in the organic resin insulating layer 2 and unnecessary electrical short circuits are caused in the thin film wiring conductor layers 3 located above and below. Therefore, it is preferable that the thickness of each of the organic resin insulating layers 2 is in the range of 5 μm to 100 μm.

Further, when the thickness of each thin film wiring conductor layer 3 of the multilayer wiring portion 4 becomes less than 1 μm, each thin film wiring conductor layer 3 becomes thin.
Has a large electric resistance, and it is difficult to transmit a predetermined electric signal to each thin-film wiring conductor layer 3,
If the thickness exceeds 40 μm, when the thin film wiring conductor layer 3 is applied to the organic resin insulating layer 2, a large stress is present in the thin film wiring conductor layer 3. It is easier to peel off. Therefore, it is preferable that the thickness of each thin-film wiring conductor layer 3 of the multilayer wiring portion 4 be in the range of 1 μm to 40 μm.

Further, the thin-film wiring conductor layer 3 is provided with a through-hole 10 in a part thereof, and the through-hole 10 has a part of the organic resin insulating layer 2 located in the upper part penetrating therein. The thin film wiring conductor layer 3 is completely wrapped by the organic resin insulation layers 2 positioned above and below, whereby the thin film wiring conductor layer 3 and the organic resin insulation layer 2 are firmly joined together. Even if an external force is applied to the thin-film wiring conductor layer 3 or the organic resin insulation layer 2, no separation occurs between the organic resin insulation layer 2 and the thin-film wiring conductor layer 3.

The through hole 1 formed in the thin film wiring conductor layer 3
0 means that if the opening diameter is less than 0.02 mm,
If the thickness exceeds 1.0 mm, the electric resistance of the thin-film wiring conductor layer 3 becomes unnecessarily high, which may adversely affect the propagation of electric signals. Therefore, the through hole 10 formed in the thin film wiring conductor layer 3 has an opening diameter of 0.02 mm to 1.0 mm.
Is preferably set in the range.

The through hole 1 formed in the thin film wiring conductor layer 3
0 indicates that etching is performed when the thin film wiring conductor layer 3 is formed on the organic resin insulating layer 2 located below by employing a thin film forming technique such as an electroless plating method, a vapor deposition method, or a sputtering method and an etching processing technique. By forming the mask in a predetermined shape, the thin film wiring conductor 3 is formed in a predetermined shape at a predetermined position.

The through-holes 10 formed in the thin-film wiring conductor layer 3 are formed in a large number in a region where the thin-film wiring conductor layer 3 is formed at a high density and the contact area between the organic resin insulating layers 2 located above and below is small. The thin film wiring conductor layer 3 has a low formation density and is formed less in a region where the contact area between the organic resin insulating layers 2 located above and below is large.

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 and the hybrid integrated circuit device are 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. Although the multilayer wiring portion 4 including the organic resin insulating layer 2 and the thin film wiring conductor layer 3 is provided only on the upper surface, the multilayer wiring portion 4 may be provided only on the lower surface side of the substrate 1 or on both upper and lower surfaces. .

[0041]

According to the multilayer wiring board of the present invention, an organic resin insulating layer and a thin film wiring conductor layer are alternately laminated, and a through hole is formed in the thin film wiring conductor layer disposed between the organic resin insulating layers. The organic resin insulating layers located vertically above and below the thin-film wiring conductor layer are integrated through the through holes provided in the thin-film wiring conductor layer, and as a result, the thin-film wiring conductor layers are positioned above and below the organic resin layer. It is completely wrapped and firmly fixed by the insulating layer, and does not cause separation between the organic resin insulating layer and the thin-film wiring conductor layer even when an external force is applied.

Further, according to 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.

[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 10 ... Through-hole

Claims (2)

[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 through a through-hole conductor, wherein a through-hole is formed in a thin-film wiring conductor layer disposed between the organic resin insulating layers. 2. The multilayer wiring board according to claim 1, wherein an opening diameter of the through hole formed in the thin-film wiring conductor layer is 0.02 mm to 1.0 mm.