JPH09283936A - Multilayer wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a multilayer wiring board in which wirings can be made fine and in which thin-film wiring conductors can be formed at high density by a method wherein an organic-resin insulating layer is formed of a photosensitive polypherlene ether resin. SOLUTION: An insulating board 1 acts as a support member which supports a multilayer wiring 4. In addition, the multilayer wiring in which organic-resin insulating layers 2 and thin-film wiring conductors 3 are arranged and installed alternately is applied to the surface of the board 1. The organic-resin insulating layers 2 which constitute the multilayer wiring 4 electrically insulate the thin- film wiring conductors 3 which are situated at the upper and lower parts, and the thin-film wiring conductors 3 act as transmission lines which transmit an electric signal. Then, the organic-resin insulating layers 2 at the multilayer wiring 4 are composed of a photosensitive polyphenylene ether resin. In addition, through holes 5 are formed in respectively prescribed positions on the organic resin insulating layer 2 at the multilayer interconnection 4, and the through holes 5 electrically connect the thin-film interconnection conductors 3 which are situated at the upper and lower parts via 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 Conventionally, in a multilayer wiring board used for a hybrid integrated circuit device, a package for housing a semiconductor element, etc., its wiring conductor is formed by a thick film forming technique such as Mo--Mn method.

The Mo-M method is usually a screen-printing method in which a high-melting metal powder of tungsten, molybdenum, manganese or the like is mixed with an organic solvent and a solvent to form a paste-like metal paste on the outer surface of the green ceramic body. Is applied in a predetermined pattern by printing, and then a plurality of these are laminated and fired in a reducing atmosphere to sinter and integrate the high melting point metal powder and the green ceramic body.

Incidentally, 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 adhered on the surface. Non-oxide ceramics such as a sintered compact or a silicon carbide sintered compact are used.

However, when the wiring conductor is formed by using this Mo-Mn method, the wiring conductor is formed by screen-printing a metal paste. Therefore, it is difficult to miniaturize the wiring conductor and the wiring conductor can be formed at a high density. It had the drawback of not being able to.

In order to solve the above-mentioned drawbacks, therefore, a multilayer wiring board is used which is formed at a high density by using a thin film forming technique capable of miniaturization instead of forming the wiring conductor by a conventional thick film forming technique. It's starting to happen.

A multilayer wiring board in which such a wiring conductor is formed by a thin film forming technique is generally a glass epoxy formed by impregnating a glass cloth woven with ceramics or glass fibers made of an aluminum oxide sintered body or the like into an epoxy resin. An insulating layer made of organic resin such as epoxy resin formed on the upper surface of an insulating substrate made of, for example, by spin coating and thermosetting, and a thin film forming technique such as electroless plating or vapor deposition of metal such as copper or aluminum And a thin film wiring conductor formed by adopting a photolithography technique are alternately laminated.

In this multilayer wiring board, the thin film wiring conductors arranged between the laminated organic resin insulating layers are electrically connected to each other through the through holes formed in the organic resin insulating layer. The through holes are formed in the organic resin insulating layer by applying a resist material on each organic resin insulating layer and exposing and developing the resist material to form a window portion having a predetermined shape at a predetermined position. Of the resist material, the organic resin insulating layer located in the window portion of the resist material is removed, holes (through holes) are formed in the organic resin insulating layer, and finally the resist material is insulated with the organic resin insulating layer. It is carried out by peeling and removing from the layer.

[0009]

However, in this conventional multilayer wiring board, an organic resin insulation layer for electrically insulating and separating the thin film wiring conductors located above and below is formed of an epoxy resin, and the epoxy resin is a comparative example. Dielectric constant of about 4 (room temperature 1
MHz), the propagation speed of the electric signal propagating through the thin film wiring conductor becomes slow. As a result, even if a semiconductor element for high speed driving is connected to the thin film wiring conductor, the semiconductor element via the thin film wiring conductor is connected. There is a drawback in that the input and output of electric signals to and from the device becomes slow and the semiconductor element cannot be driven at high speed.

Further, in this conventional multilayer wiring board, a resist material is applied onto the organic resin insulating layer and the through hole is formed in the organic resin insulating layer by using the resist material.
In order to form a through hole in the organic resin insulating layer, a resist material to be peeled and removed later is required separately, and the multilayer wiring board as a product is also expensive.

[0011]

According to the present invention, an organic resin insulation layer and a thin film wiring conductor are alternately laminated on a substrate, and the upper and lower thin film wiring conductors are provided through a through hole provided in the organic resin insulation layer. A multi-layer wiring board electrically connected to each other, wherein the organic resin insulating layer is formed of a photosensitive polyphenylene ether resin.

Further, the present invention is characterized in that the thickness of each of the laminated organic resin insulating layers is 5 μm to 100 μm.

Further, according to the present invention, the upper surface of each of the laminated organic resin insulating layers has a center line average roughness (Ra) of 0.05 μm.
m ≦ Ra ≦ 5 μm.

According to the multilayer wiring board of the present invention, since the wiring conductor is formed by the thin film forming technique, the wiring can be miniaturized, and the thin film wiring conductor can be formed with extremely high density. According to the multilayer wiring board of the present invention,
An organic resin insulating layer that electrically insulates and separates the upper and lower thin-film wiring conductors is formed of photosensitive polyphenylene ether. Since the relative dielectric constant of the photosensitive polyphenylene ether is as low as about 3 (room temperature 1 MHz), the thin film is formed. The propagation speed of the electrical signal propagating through the wiring conductor can be made extremely fast, and as a result, when a semiconductor element for high speed driving is connected to the thin film wiring conductor, it enters the semiconductor element through the thin film wiring conductor at high speed. Output signals can be taken in and out, and a semiconductor element can be driven at high speed.

Further, according to the multilayer wiring board of the present invention, since the organic resin insulating layer is formed of photosensitive polyphenylene ether, each organic resin insulating layer uses a resist material by exposing and developing its precursor. The through-hole can be directly formed without performing the above-mentioned process, the through-hole can be easily formed in the organic resin insulating layer without using a resist material, and the multilayer wiring board as a product can be inexpensive. .

Furthermore, according to the multilayer wiring board of the present invention,
When the upper surface of each of the laminated organic resin insulating layers is set to have a center line average roughness (Ra) of 0.05 μm ≦ Ra ≦ 5 μm, the upper and lower organic resin insulating layers to be laminated can be bonded very strongly, As a result, the function of the multilayer wiring board can be maintained for a long period of time.

[0017]

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, in which 1 is an insulating substrate, 2 is an organic resin insulating layer, and 3 is a thin film wiring conductor.

On the upper surface of the insulating substrate 1, a multilayer wiring 4 composed of an organic resin insulating layer 2 and a thin film wiring conductor 3 is arranged, and it functions as a supporting member for supporting the multilayer wiring 4.

The insulating substrate 1 is an oxide ceramic such as an aluminum oxide sintered body or a mullite sintered body, or an aluminum nitride sintered body having an oxide film on its surface.
It is made of a non-oxide ceramic such as a silicon carbide sintered body, and an electrically insulating material such as a glass epoxy resin obtained by impregnating a cloth woven with glass fiber with an epoxy resin. For example, an aluminum oxide sintered body. In the case of being formed of, alumina (Al ₂ O ₃ ) and silica (Si
O ₂ ), calcia (CaO), magnesia (MgO), and other raw material powders are mixed with an appropriate organic solvent and solvent to form a slurry, which is then applied by the well-known doctor blade method or calendar roll method. To form a ceramic green sheet (ceramic green sheet), and then subject the ceramic green sheet to an appropriate punching process to form a predetermined shape and a high temperature (about 160).
(0 ° C.) or by mixing a raw material powder such as alumina with an appropriate organic solvent and solvent to prepare the raw material powder, and molding the raw material powder into a predetermined shape by a press molding machine, and finally It is manufactured by firing the molded body at a temperature of about 1600 ° C.

On the upper surface of the insulating substrate 1, the organic resin insulating layers 2 and the thin film wiring conductors 3 are alternately arranged in multiple layers and the multilayer wiring 4 is adhered. The resin insulation layer 2 serves to electrically insulate the thin film wiring conductors 3 located above and below, and the thin film wiring conductor 3 also serves as a transmission path for transmitting an electric signal.

The organic resin insulation layer 2 of the multi-layer wiring 4 is made of a photosensitive polyphenylene ether resin. For example, an allyl-modified polyphenylene ether having an olefin-based photosensitive group is added to an organic peroxide such as a dialkyl peroxide as a curing agent. To obtain a paste-like photosensitive polyphenylene ether resin precursor by adding and mixing toluene as a solvent, the photosensitive polyphenylene ether resin precursor is formed on the insulating substrate 1 to a predetermined thickness by spin coating or doctor blade method. Then, this is applied to 300 to 3000 by an exposure device using a high pressure mercury lamp or the like.
A predetermined exposure is performed with an energy of J / cm ² and a hole is formed as a through hole 5 described later by developing with a spray developing machine or the like.
Formed by heating for ~ 60 minutes to fully cure.

Further, the organic resin insulating layer 2 of the multi-layer wiring 4 has through holes 5 formed at respective predetermined positions, and the through holes 5 are thin film wiring conductors which are vertically arranged with the organic resin insulating layer 5 interposed therebetween. , And each of them acts as a connection path for electrically connecting them.

Since the organic insulating resin layer 2 is formed of a photosensitive polyphenylene ether resin in the through hole 5, when the above-mentioned organic resin insulating layer 2 is formed,
A resist material for forming a through hole 5 in the organic resin insulating layer 2 directly formed on the organic resin insulating layer 2 by exposing and developing the photosensitive polyphenylene ether resin precursor coated on the insulating substrate 1. It is not necessary to separately prepare the through hole 5, so that the through hole 5 can be easily formed in the organic resin insulating layer 2 and the multilayer wiring board as a product can be inexpensive.

A thin film wiring conductor 3 having a predetermined pattern is also disposed on the upper surface of each of the organic resin insulating layers 2, and the thin film wiring conductors 3 located above and below with the organic resin insulating layer 2 interposed therebetween. Each is electrically connected through a thin film wiring conductor 3 arranged in a through hole 5 formed in the organic resin insulating layer 2.

The thin film wiring conductor 3 provided on the upper surface of each organic resin insulating layer 2 and in the through hole 5 is made of a metal material such as copper, nickel, gold or aluminum by electroless plating, vapor deposition or sputtering. Is formed by adopting the thin film forming technology and the etching processing technology, and when it is made of copper, 0.06 mol / liter of copper sulfate is formed on the upper surface of the organic resin insulating layer 2 and the inner surface of the through hole 5. , Formalin 0.3 mol / l, sodium hydroxide 0.35 mol / l, ethylenediaminetetraacetic acid 0.35 mol / l, using an electroless copper plating bath to deposit a copper layer having a thickness of 1 μm to 40 μm. Thereafter, the copper layer is processed into a predetermined pattern by an etching processing method so as to be disposed between the organic resin insulating layers 2. In this case, since the thin-film wiring conductor 3 is formed by a thin-film forming technique, the wiring can be miniaturized, whereby the thin-film wiring conductor 3 can be formed at an extremely high density.

The organic resin insulating layer 2 with which the thin film wiring conductor 3 is in contact is formed of a photosensitive polyphenylene ether resin, and the relative permittivity of the photosensitive polyphenylene ether resin is as low as 3 (room temperature 1 MHz). The propagation speed of the electric signal propagating through the thin film wiring conductor 3 becomes extremely fast. As a result, when the thin film wiring conductor 3 is connected to a semiconductor element that is driven at high speed, the thin film wiring conductor 3 is connected to the semiconductor element at high speed. Input / output signals can be taken in and out, and the semiconductor element can be driven at high speed.

The multilayer wiring 4 formed by alternately arranging the organic resin insulating layers 2 and the thin-film wiring conductors 3 in multiple layers has the center line average roughness (Ra) on the upper surface of each organic resin insulating layer 2. With a rough surface of 0.05 μm ≦ Ra ≦ 5 μm, the organic resin insulating layer 2 and the thin film wiring conductor 3 can be joined firmly and the organic resin insulating layers 2 located above and below can be firmly joined. Therefore, each organic resin insulating layer 2 of the multilayer wiring 4 is roughened by subjecting the upper surface thereof to reactive ion etching treatment using a gas such as CHF ₃ , CF ₄ , Ar, O ₂ or the like, and the center line average roughening is performed. (Ra) 0.05 μm ≦ R
It is preferable to have a rough surface with a ≦ 5 μm.

When the thickness of each of the organic resin insulating layers 2 exceeds 100 μm, the holes are made clear when the holes to be through holes are formed by exposing and developing the photosensitive polyphenylene ether resin precursor. There is a risk that it becomes difficult to form the through holes 5 in the organic resin insulating layer 2 and it becomes difficult to form the through holes 5 in the organic resin insulating layer 2.
Also, when the thickness is less than 5 μm, unnecessary holes are formed in the organic resin insulating layer 2 when the rough surface processing is performed on the upper surface of the organic resin insulating layer 2 to increase the bonding strength of the organic resin insulating layer 2 located above and below. There is a risk of causing an unnecessary electrical short circuit in the thin film wiring conductor 3 located. 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 2 of the multilayer wiring 4 is less than 1 μm, the electric resistance of each thin film wiring conductor 3 becomes large and a predetermined electric signal is transmitted to each thin film wiring conductor 3. Becomes difficult, and again 40
If the thickness exceeds μm, stress is internal to the thin film wiring conductor 3 when the thin film wiring conductor 3 is applied to the organic resin insulating layer 2, and the large internal stress causes the thin film wiring conductor 3 to peel off from the organic resin insulating layer 2. It is an easy source. Therefore, the multilayer wiring 4
The thickness of each thin film wiring conductor 2 is preferably set in the range of 1 μm to 40 μm.

[0031]

According to the multilayer wiring board of the present invention, since the wiring conductor is formed by the thin film forming technique, the wiring can be miniaturized, and the thin film wiring conductor can be formed with extremely high density. Further, according to the multilayer wiring board of the present invention, the organic resin insulating layer for electrically insulating and separating the thin film wiring conductors located above and below is formed of photosensitive polyphenylene ether, and the relative dielectric constant of the photosensitive polyphenylene ether is Since it is as low as 3 (room temperature 1 MHz), the propagation speed of the electric signal propagating through the thin film wiring conductor can be made extremely fast. As a result, when the semiconductor element for high speed driving is connected to the thin film wiring conductor, the thin film wiring It is possible to input and output signals to and from semiconductor devices at high speed via conductors.
It is possible to drive the semiconductor element at high speed.

Further, according to the multilayer wiring board of the present invention, since the organic resin insulating layer is formed of photosensitive polyphenylene ether, each organic resin insulating layer uses a resist material by exposing and developing its precursor. The through-hole can be directly formed without performing the above-mentioned process, the through-hole can be easily formed in the organic resin insulating layer without using a resist material, and the multilayer wiring board as a product can be inexpensive. .

Furthermore, according to the multilayer wiring board of the present invention,
When the upper surface of each of the laminated organic resin insulating layers is set to have a center line average roughness (Ra) of 0.05 μm ≦ Ra ≦ 5 μm, the upper and lower organic resin insulating layers to be laminated can be bonded very strongly, As a result, the function of the multilayer wiring board can be maintained for a long period of time.

[Brief description of drawings]

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

[Explanation of symbols]

 1 ... Insulating substrate 2 ... Organic resin insulating layer 3 ... Thin film wiring conductor 4 ... Multilayer wiring 5 ... Through hole 6 ... Groove

Claims (3)

[Claims] 1. An organic resin insulating layer and a thin film wiring conductor are alternately laminated on a substrate, and the upper and lower thin film wiring conductors are electrically connected through through holes provided in the organic resin insulating layer. A multilayer wiring board comprising the organic resin insulating layer formed of a photosensitive polyphenylene ether resin. 2. The multilayer wiring board according to claim 1, wherein the thickness of each of the stacked organic resin insulating layers is 5 μm to 100 μm. 3. An upper surface of each of the laminated organic resin insulating layers has a center line average roughness (Ra) of 0.05 μm ≦ Ra ≦ 5.
The multilayer wiring board according to claim 1, wherein the thickness is μm.