JPH11233909A - Wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the infiltration of noises into electronic components such as semiconductor devices which are installed via wiring conductor layers by forming a magnetic area, containing magnetic powder on a part of the wiring conductor layers which covers an organic resin insulating layer. SOLUTION: A substrate 1 is made of oxide base ceramics, such as an aluminum oxide sintered compact and mullite sintered compact. The substrate 1 supports a multilayered wiring part 4 comprised of organic resin insulating layers 2 and wiring conductor layers 3 on its top. A through-hole 5 is formed in the substrate 1, and its inner walls are coated with a conductive layer 6 whose ends are led out to both upper an lower sides of the substrate 1. The through-hole 5 electrically connects between the wiring conductor layers 3 of the multilayered wiring part 4 formed on the top of the substrate 1 and outer electrical circuits. The through-hole 5 is completely filled with an organic resin filler 7 of epoxy resin or the like. Both ends of the organic resin filler 7 are on flush with the surface of the conductive layer 6 which covers both the upper and lower sides of the substrate 1. Accordingly, the organic resin insulating layers 2 and the wiring conductor layers 3 can be planarized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wiring board,
More specifically, the present invention relates to a wiring board used for a hybrid integrated circuit device or a semiconductor device mounted on an information processing device or the like.

[0002]

2. Description of the Related Art Conventionally, a wiring substrate used in a hybrid integrated circuit device, a package for housing a semiconductor element, or the like has a 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 printed and applied in a predetermined pattern on the outer surface of a sheet-like green ceramic body by a screen printing method, and then a plurality of these are laminated and fired in a reducing atmosphere. A method of sintering and integrating a high melting point 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 a nitride having an oxide film deposited on the surface. Non-oxide ceramics such as an aluminum 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, instead of forming the wiring conductor by a conventionally known thick film forming technique, a wiring board formed by using a thin film forming technique capable of miniaturization is used. It has become.

A wiring board in which such a wiring conductor is formed by a thin film forming technique is made of a ceramic made of an aluminum oxide sintered body or a glass epoxy resin formed by impregnating a glass cloth woven with glass fibers with an epoxy resin. An insulating layer made of an organic resin such as epoxy resin formed by spin coating and thermosetting on the upper surface of the substrate, and a thin film forming technique such as electroless plating or vapor deposition of a metal such as copper or aluminum, and a photolithography technique. And a wiring conductor layer formed by adopting the structure is alternately laminated, and a wiring conductor layer positioned above and below is electrically connected via a through-hole conductor provided in the organic resin insulating layer. Forming a bonding pad electrically connected to the wiring conductor layer on the upper surface of the uppermost organic resin insulating layer. Can, active component, a capacitor such as a semiconductor element, the passive components of the electrode of the resistor or the like via a brazing material such as solder is adapted to be connected to the bonding pad.

[0008]

However, recently,
Information processing devices have rapidly advanced in performance, and accordingly, semiconductor devices and hybrid integrated circuit devices mounted on information processing devices have been driven at high speeds and have become extremely susceptible to noise. In the conventional wiring board, the wiring conductor layer made of a metal material such as copper or aluminum provided on the organic resin insulating layer easily propagates the harmonic noise. If the noise enters, the noise propagates through the wiring conductor layer as it is and enters the electronic components such as the semiconductor element, thereby causing a malfunction of the electronic component such as the semiconductor element.

At the same time, if the wiring conductor layer provided on the organic resin insulating layer has a bent portion, when an electric signal propagates through the wiring conductor layer, noise is generated due to reflection at the bent portion and the like. This has a drawback that it enters electronic components such as semiconductor elements via the wiring conductor layer and causes the semiconductor elements and the like to malfunction.

The present invention has been devised in view of the above-mentioned drawbacks, and has as its object to effectively prevent noise from entering an electronic component such as a semiconductor element mounted via a wiring conductor layer,
It is an object of the present invention to provide a wiring board capable of operating electronic components such as semiconductor elements normally for a long period of time.

[0011]

SUMMARY OF THE INVENTION The present invention provides a wiring board comprising a wiring conductor layer formed on an organic resin insulating layer,
A magnetic region containing a magnetic powder is formed in a part of the wiring conductor layer.

Further, in the present invention, the content of the magnetic powder in the magnetic region of the wiring conductor layer is 10 to 70% by weight.

Further, according to the present invention, the wiring conductor layer may be made of gold, silver,
Copper, aluminum or their alloys as the main component,
The magnetic powder is mainly formed of ferrite.

According to the wiring board of the present invention, since a magnetic region is formed in at least a part of the wiring conductor layer made of gold, silver, copper or the like by containing a magnetic powder made of ferrite or the like, wiring from an external electric circuit is performed. Noise generated by reflection of noise entering the conductor layer and electric signals propagating through the wiring conductor layer at the bent portion of the wiring conductor layer is contained in the wiring conductor layer before entering the electronic component such as a semiconductor element to be mounted. The converted magnetic powder is converted into heat energy and absorbed, and as a result, noise does not enter the electronic components such as the semiconductor device, and the electronic components such as the semiconductor device can always be normally operated.

[0015]

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

The substrate 1 has an organic resin insulating layer 2 on its upper surface.
And a wiring conductor layer 3, which serves 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 material such as an aluminum nitride sintered body or a silicon carbide sintered body having an oxide film on its 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 By adding an appropriate organic solvent and a solvent to raw material powders such as aluminum oxide, silicon oxide, magnesium oxide, and calcium oxide to form a slurry, and using a conventionally known doctor blade method or calender roll method, A ceramic green sheet (ceramic green sheet) is formed, and then a suitable punch is formed on the ceramic green sheet. By baking at a high temperature (about 1600 ° C.) with can process the applied and forms a predetermined shape,
Alternatively, an appropriate organic solvent and a solvent are added to and mixed with a raw material powder such as aluminum oxide to prepare the raw material powder, and at the same time, the raw material powder is formed into a predetermined shape by a press molding machine. In the case of being manufactured by baking with, and made of glass epoxy resin, for example, impregnating an epoxy resin precursor into a cloth woven of glass fiber and thermally curing the epoxy resin precursor at a predetermined temperature Produced by

The substrate 1 is formed with through holes 5 having a hole diameter of, for example, 300 μm to 500 μm, which penetrate the upper and lower surfaces of the substrate 1. A conductive layer 6 is applied.

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

The conductive layer 6 formed on the inner wall of the through hole 5 and on the upper and lower surfaces of the substrate 1 is made of a metal material such as copper or nickel, for example, and employs well-known plating and etching methods. As a result, it is formed on 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 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 a multilayer wiring formed on both upper and lower surfaces of the substrate 1. The wiring conductor layers 3 of the portion 4 are electrically connected 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, and the through-hole 5 is completely filled with the organic resin filler 7, and at the same time, 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 provided on the upper and / or lower surface of the substrate 1 with an organic resin insulating layer 2 and a wiring conductor layer 3 which will be described later.
When the multilayer wiring portion 4 is formed, the organic resin insulating layer 2 and the wiring conductor layer 3 of the multilayer wiring portion 4 function to maintain flatness.

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.

On the upper surface of the substrate 1, a multilayer wiring portion 4 formed by alternately arranging an organic resin insulating layer 2 and a wiring conductor layer 3 in multiple layers is attached. The organic resin insulating layer 2 serves to electrically insulate the upper and lower wiring conductor layers 3, and the wiring conductor layer 3 functions as a transmission path for transmitting electric signals.

The organic resin insulating layer 2 of the multilayer wiring section 4
It is made of an organic resin such as an epoxy resin, a bismaleimide triazine resin, a polyphenylene ether resin, and a fluororesin. For example, when the resin is made of an epoxy resin, it is amine-cured to a bisphenol A type epoxy resin, a novolak type epoxy resin, a glycidyl ester type epoxy resin, or the like. A curing agent such as a curing agent, an imidazole-based curing agent, an acid anhydride-based curing agent is added and mixed to obtain a paste-like epoxy resin precursor, and the epoxy resin precursor is adhered to the upper portion of the substrate 1 by spin coating. After that, this is brought to 80 ° C. to 200 ° C.
The film is formed by heat-treating with heat of 0.5 ° C. for 0.5 to 3 hours and heat-curing.

Further, the organic resin insulating layer 2 of the multilayer wiring section 4
Has a through hole 8 having a minimum diameter of about 1.5 times the thickness of the organic resin insulating layer 2 at each predetermined position.
And serves as a forming hole for forming a through-hole conductor 9 that electrically connects each of the wiring conductor layers 3 located above and below via the through hole.

The through holes 8 provided in the organic resin insulating layer 2 are formed in the organic resin insulating layer 2 to have a predetermined diameter by employing a conventionally known photolithography technique.

A wiring conductor layer 3 having a predetermined pattern is formed on the upper surface of each organic resin insulating layer 2.
The through hole conductor 9 is provided on the inner wall of the through hole 8
Are arranged, and each of the wiring conductor layers 3 located vertically above and below the organic resin insulating layer 2 with the through-hole conductor 9 therebetween is electrically connected.

The wiring conductor layer 3 and the through-hole conductor layer 9 provided on the upper surface of each of the organic resin insulating layers 2 and the inner wall of the through-hole 8 are made of a metal material such as copper, gold, silver 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 a photolithography technique. For example, in the case of being formed of copper, on the upper surface of the organic resin insulating layer 2 and the inner surface of the through hole 8, Copper sulfate 0.06 mol / l, formalin 0.
An electroless copper plating bath consisting of 3 mol / l, sodium hydroxide 0.35 mol / l and ethylenediaminetetraacetic acid 0.35 mol / l has a thickness of 1 μm to 4 μm.
Copper having a thickness of 0 μm is deposited, and thereafter, the copper layer is processed into a predetermined pattern by a photolithography technique to be disposed between the organic resin insulating layers 2 and on the inner wall of the through hole 8. In this case, since the wiring conductor layer 3 and the through-hole conductor 9 are formed by a thin film forming technique, the wiring can be miniaturized, and thus the wiring conductor layer 3 can be formed at an extremely high density. When the wiring conductor layer 3 and the through-hole conductor 9 are formed of copper, gold, silver, aluminum or a metal containing these as a main component, the electric resistivity of the copper, gold, etc. is as low as 3 μΩ · cm or less. Therefore, even if an electric signal propagates through the wiring conductor layer 3 and the through-hole conductor 9, no large attenuation or the like occurs in the electric signal, whereby the semiconductor element mounted and mounted via the wiring conductor layer 3 and the through-hole conductor 9 is formed. Electronic parts A such as
The electric signal can be reliably transmitted and received with respect to. Further, when the wiring conductor layer 3 is made of copper, gold, silver, aluminum or a metal containing these as a main component, the melting point of the copper, gold, etc. is about 660 to 1080 ° C. The thermosetting temperature of the insulating layer 2 is 80 to 20
Since the temperature is extremely low at 0 ° C., when the organic resin insulating layer 2 is formed by the thermosetting treatment, the wiring conductor layer 3 does not diffuse and the wiring conductor layer 3 having a predetermined pattern is formed between the organic resin insulating layers 2. be able to.

The multilayer wiring portion 4 formed by alternately arranging the organic resin insulating layers 2 and the wiring conductor layers 3 in multiple layers has a center line average roughness (Ra) on the upper surface of each organic resin insulating layer 2. If the rough surface is set to 0.05 μm ≦ Ra ≦ 5 μm in ()), the bonding between the organic resin insulating layer 2 and the wiring conductor layer 3 and the bonding between the organic resin insulating layers 2 located above and below can be made strong. Therefore, it is preferable that the upper surface of each organic resin insulating layer 2 of the multilayer wiring section 4 is roughened by an etching method or the like, and the roughened surface has a center line average roughness (Ra) of 0.05 μm ≦ Ra ≦ 5 μm. .

The count value of the height (Pc) of the unevenness of the surface of the organic resin insulating layer 2 at a length of 2.5 mm is 500 or more for 1 μm ≦ Pc ≦ 10 μm.
2500 μm of 1 μm ≦ Pc ≦ 1 μm, 0.01 μm
If ≦ Pc ≦ 0.1 μm is set to 12500 or more, the bonding between the organic resin insulating layer 2 and the wiring conductor layer 3 and the bonding between the organic resin insulating layers 2 located above and below become stronger. Therefore, the count value of the height (Pc) of the unevenness at a length of 2.5 mm on the surface of the organic resin insulating layer 2 is 1 μm.
500 or more m ≦ Pc ≦ 10 μm, 0.1 μm ≦ Pc
2500 ≦ 1 μm, 0.01 μm ≦ Pc ≦ 0.
Preferably, 1 μm is 12,500 or more.

The center line average roughness (Ra) of the upper surface of the organic resin insulating layer 2 and the count value of the unevenness height (Pc) at a length of 2.5 mm are obtained by measuring the surface of the organic resin insulating layer 2 with an atomic force. Microscope (Dimensio manufactured by Digital Instruments Inc.
n 3000-Nano Scope III) 50μm diagonal (70μm)
m), the surface condition was inspected and measured, and each numerical value was obtained from the measurement result.

The center line average roughness (Ra) is 0.0
5 μm ≦ Ra ≦ 5 μm, the count value of the height of unevenness (Pc) at a length of 2.5 mm is 1 μm ≦ Pc ≦ 10 μm
m is 500 or more, and 0.1 μm ≦ Pc ≦ 1 μm is 250
0 or more, 0.01 μm ≦ Pc ≦ 0.1 μm is 1250
The surface of the zero or more organic resin insulating layers 2 is roughened to a predetermined roughness by spraying a gas such as CHF ₃ , CF ₄ , Ar or the like on the upper surface of the organic resin insulating layers 2 or performing active ion etching. You.

Further, when the thickness of each of the organic resin insulating layers 2 exceeds 100 μm, when the through holes 8 are formed by employing photolithography technology in the organic resin insulating layers 2, the etching process time becomes longer, and It is difficult to form the hole 8 into a desired clear shape, and if it is less than 5 μm, rough surface processing is performed on the upper surface of the organic resin insulating layer 2 to increase the bonding strength of the upper and lower organic resin insulating layers 2. In this case, there is a risk that unnecessary holes may be formed in the organic resin insulating layer 2 and unnecessary electrical short circuits may be caused in the wiring conductor layers 3 located above and below. Therefore, the organic resin insulating layer 2 has a thickness of 5 μm to 100 μm.
Is preferably set in the range.

Further, if the thickness of each wiring conductor layer 3 of the multilayer wiring portion 4 is less than 1 μm, the electric resistance value of each wiring conductor layer 3 becomes large, and a predetermined electric signal is applied to each wiring conductor layer 3. Is difficult to transmit, and 40 μm
When the wiring conductor layer 3 is applied to the organic resin insulating layer 2, a large stress is present inside the wiring conductor layer 3 when the wiring conductor layer 3 is adhered to the organic resin insulating layer 2.
It is easier to peel off. Therefore, the multilayer wiring section 4
The thickness of each thin-film wiring conductor layer 3 is preferably in the range of 1 μm to 40 μm.

The wiring conductor layer 3 of the multilayer wiring part 4 has a magnetic region formed by containing at least a part of magnetic powder, and the magnetic powder enters the wiring conductor layer 3 from an external electric circuit. The noise generated by the reflection of the electric signal propagating through the wiring conductor layer 3 at the bent portion of the wiring conductor layer 3 is converted into thermal energy and absorbed before entering the electronic component A such as a semiconductor element or a capacitance element. As a result, noise does not enter the electronic component A such as a semiconductor element, and the electronic component A such as a semiconductor element can always be normally operated.

The magnetic powder contained in at least a part of the wiring conductor layer 3 is ZnFe ₂ O ₄ , MnFe ₂ O
₄ , FeFe ₂ O ₄ , CoFe ₂ O ₄ , NiFe
Ferrites such as ₂ O ₄ and CuFe ₂ O ₄ are preferably used.

The above ZnFe ₂ O ₄ , MnFe ₂ O ₄
Ferrite such as 1200 in a neutral or reducing atmosphere
Although the magnetism is lost at a temperature of ° C., the thermosetting temperature of the organic resin insulating layer 2 is extremely low at 80 to 200 ° C., so that the organic resin insulating layer 2 was contained in the wiring conductor layer 3 when the organic resin insulating layer 2 was formed by thermosetting. The magnetic powder does not lose magnetism, so that noise entering the wiring conductor layer 3 and the wiring conductor layer 3
The noise generated due to the reflection of the electric signal propagating through the bent portion of the wiring conductor layer 3 or the like can be surely converted into thermal energy and absorbed.

Further, if the amount of the magnetic powder contained in the wiring conductor layer 3 is less than 10% by weight, noise and the like entering the wiring conductor layer 3 cannot be satisfactorily absorbed. %, The conductive resistance of the wiring conductor layer 3 becomes high, and it becomes difficult to transmit an electric signal to the wiring conductor layer 3 satisfactorily. Therefore, it is preferable that the amount of the magnetic powder contained in the wiring conductor layer 3 be in the range of 10 to 70% by weight.

The content of the magnetic powder in the wiring conductor layer 3 is as follows:
For example, when the wiring conductor layer 3 is formed by a plating method, it is performed by adding a magnetic powder in a plating bath in advance.

Thus, according to the wiring board of the present invention, the electronic component A such as a semiconductor element, a capacitor, and a resistor is mounted and mounted on the multilayer wiring section 4 attached to the upper surface of the substrate 1. Are electrically connected to the wiring conductor layer 3 to form a semiconductor device or a hybrid integrated circuit device. If the conductive layer 6 attached to the lower surface of the substrate 1 is connected to an external electric circuit, the semiconductor device or the hybrid integrated circuit device is formed. The integrated circuit device is here electrically connected to an 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 spirit of the present invention. Although the multilayer wiring portion 4 formed by alternately laminating the organic resin insulating layers 2 and the wiring conductor layers 3 is applied only on the upper surface, the multilayer wiring portion 4 may be provided only on the lower surface side of the substrate 1. It may be provided on both upper and lower main surfaces.

In the above-described embodiment, the organic resin insulating layers 2 and the wiring conductor layers 3 are alternately formed in multiple layers on the upper surface of the substrate 1. However, one organic resin insulating layer serving also as the substrate 1 has one wiring conductor layer. 3 may be used.

[0045]

According to the wiring board of the present invention, gold, silver,
At least a part of the wiring conductor layer made of copper, aluminum or the like contains a magnetic powder made of ferrite or the like to form a magnetic region. Therefore, noise that enters the wiring conductor layer from an external electric circuit and electricity that propagates through the wiring conductor layer. Noise generated by reflection of a signal at the bent portion of the wiring conductor layer is converted into thermal energy by the magnetic powder contained in the wiring conductor layer and absorbed by the magnetic powder contained in the wiring conductor layer before entering the electronic component such as a semiconductor element to be mounted. As a result, noise does not enter the electronic components such as the semiconductor elements, and the electronic components such as the semiconductor elements can always be normally operated.

[Brief description of the drawings]

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Substrate 2 ... Organic resin insulating layer 3 ... Wiring conductor layer 4 ... Multilayer wiring part 8 ... Through-hole 9 ... Through-hole conductor A ... Electronic components

Claims (3)

[Claims] 1. A wiring board comprising a wiring conductor layer formed on an organic resin insulating layer, wherein a magnetic region containing a magnetic powder is formed in a part of the wiring conductor layer. Wiring board. 2. The wiring board according to claim 1, wherein the content of the magnetic powder in the magnetic region of the wiring conductor layer is 10 to 70% by weight. 3. The wiring board according to claim 1, wherein the wiring conductor layer is mainly composed of gold, silver, copper, aluminum or an alloy thereof, and the magnetic powder is mainly composed of ferrite.