JPH1197851A - Multilayered wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multilayered wiring board, in which a propagation speed of an electric signal in a conductive layer provided in a board is increased and a semiconductor device driven at a high-speed can be mounted. SOLUTION: In a multilayered wiring board, in which an organic resin insulation layer 2 and a thin-film wiring conductor layer 3 are alternately laminated in a multilayer on a board 1 having a conductive layer 6 to form a multilayered wiring part 4, and also the conductive layer 6 is electrically connected to the thin-film wiring conductor layer 3, the board 1 is formed in an organic resin by mixing aramid fibers of which the surface is coated with polytetrafluoroethylene.

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-shaped metal paste is printed and applied on the outer surface of the green ceramic body in a predetermined pattern by a screen printing method. Then, a plurality of these 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 a nitride having an oxide film deposited on the surface. Non-oxide ceramics such as aluminum sintered bodies and silicon carbide sintered bodies 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 in which a part of the wiring conductor is formed at a high density by using a thin film forming technique which can be miniaturized instead of the conventional thick film forming technique is adopted. It has become

[0007] Such a multilayer wiring board is formed by impregnating a ceramic or glass fiber woven cloth made of aluminum oxide sintered body or the like having through holes penetrating on both upper and lower surfaces with a glass epoxy resin formed by impregnating the cloth with an epoxy resin. And a conductive layer made of a metal material such as copper derived from the upper surface of the insulating substrate to the lower surface through the inner wall of the through-hole, and an epoxy resin or the like adhered to at least one main surface of the insulating substrate. An organic resin insulating layer and a thin film wiring conductor layer made of a metal such as copper or aluminum are alternately laminated in multiple layers, and a part of the thin film wiring conductor layer is formed in a through hole provided in the organic resin insulating layer in the conductive layer. And a multi-layer wiring portion connected through a through-hole conductor attached to the wall surface. Or connect to the road, so as to electrically connect the thin film wiring conductor layers to each other in the multilayer wiring portion is deposited on the upper and lower surfaces of the insulating substrate.

In the multilayer wiring board, copper is applied to the upper surface, the inner wall and the lower surface of the through hole by an electroless plating method or the like, and is processed into a predetermined pattern by a photolithography technique. A conductive layer extending from the upper surface of the insulating substrate to the lower surface via the inner wall of the through hole is applied, and then an organic resin such as an epoxy resin formed on the upper and / or lower surface of the insulating substrate by a spin coating method, a thermosetting treatment or the like. An insulating layer made of resin and a thin film wiring conductor layer formed by adopting a thin film forming technology such as electroless plating and a photolithography technology on a metal such as copper or aluminum are alternately laminated in multiple layers to form a multilayer wiring portion. It is manufactured by forming.

The conductive layer and the thin-film wiring conductor layer formed on the insulating substrate are electrically connected to each other via a through-hole conductor attached to the inner wall surface of the through-hole provided in the organic resin insulating layer. The through holes formed in the organic resin insulating layer are formed by applying a resist material on the organic resin insulating layer and exposing and developing the resist material to form a window having a predetermined shape at a predetermined position. An etchant is placed in the window of the material, the organic resin insulating layer located in the window of the resist material is removed, a hole (through hole) is formed in the organic resin insulating layer, and finally, the resist material is coated with an organic resin. The through-hole conductor, which is formed by peeling and removing the insulating layer from the insulating layer and adhered to the inner wall surface of the through hole, is formed by, for example, applying copper or the like to the inner wall surface of the through hole by electroless plating. It is formed by.

[0010]

However, in this multilayer wiring board, the relative permittivity of the aluminum oxide sintered body or the glass epoxy resin constituting the board is as high as about 5 or more (room temperature, 1 MHz). A delay occurs in an electric signal transmitted through the formed conductive layer, and a high-speed driven semiconductor element that needs to transmit the electric signal at a high speed has a disadvantage that it cannot be mounted.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned drawbacks. It is an object of the present invention to increase the propagation speed of an electric signal in a conductive layer provided on a substrate and to mount a semiconductor element for high-speed driving. It is to provide a multilayer wiring board.

[0012]

According to the present invention, there is provided a multilayer wiring portion comprising an organic resin insulating layer and a thin film wiring conductor layer alternately laminated on a substrate having a conductive layer. A multilayer wiring board formed by electrically connecting a thin-film wiring conductor layer, wherein the substrate is formed by impregnating an organic resin with aramid fibers having a surface coated with polytetrafluoroethylene. It is a feature.

Further, the present invention is characterized in that the impregnation rate of the aramid fiber in the organic resin is 10 to 60% by weight.

According to the multilayer wiring board of the present invention, the substrate is formed by impregnating an organic resin with an aramid fiber whose surface is coated with polytetrafluoroethylene in an amount of 10 to 60% by weight. (Room temperature, 1 MHz) or less, which makes it possible to increase the propagation speed of the electric signal transmitted through the conductive layer formed on the substrate, and to perform high-speed driving in which the electric signal needs to be transmitted at a high speed. Mounting of a semiconductor element or the like becomes possible.

[0015]

Next, the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 shows an embodiment of a multilayer wiring board according to the present invention, wherein 1 is a substrate, 2 is an organic resin insulating layer, and 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 formed by laminating a plurality of electrically insulating substrates such as an aramid substrate in which an aramid fiber whose surface is coated with polytetrafluoroethylene is impregnated in an organic resin such as an epoxy resin. Each is formed by integrally joining, specifically, an epoxy resin precursor is impregnated with aramid fiber and heat-treated at 80 to 150 ° C. for 1 to 90 minutes to form an epoxy resin precursor. After curing to a B stage, a plurality of electric insulating substrates are obtained. Thereafter, the electric insulating substrates are stacked one on top of the other and heat-treated at 80 to 200 ° C. for 30 to 180 minutes to completely heat the epoxy resin precursor. It is made by curing.

A through hole 5 having a diameter of, for example, 0.3 mm to 0.5 mm penetrating the upper and lower surfaces of the substrate 1 is formed by subjecting the substrate 1 to a drilling method or the like, and A conductive layer 6 made of a metal material such as copper, aluminum, silver, or nickel is formed on the inside, upper and lower surfaces of the substrate 1 and the inner wall of the through hole 5.

The conductive layer 6 formed on the inside, the upper and lower surfaces of the substrate 1 and the inner wall of the through hole 5 is connected to a thin-film wiring conductor layer 3 of a multilayer wiring portion 4 formed on the upper surface of the substrate 1 and an external electric circuit. Or the thin film wiring conductor layers 3 of the multilayer wiring portion 4 are electrically connected to each other, or the substrate 1
When the multilayer wiring portions 4 are provided on both upper and lower surfaces of the substrate 1, the thin film wiring conductor layers of the multilayer wiring portions 4 on both surfaces are electrically connected to each other, and the conductive layers formed inside the substrate 1 and on both upper and lower surfaces are formed. The layer 6 has a metal material foil made of a metal material such as copper, aluminum, silver, nickel, iron or the like adhered to the upper and lower surfaces of each aramid substrate forming the substrate 1, and this is patterned into a predetermined pattern using an etching technique. The conductive layer 6 formed on the inner wall of the through hole 5 of the substrate 1 is made of a metal such as copper, nickel, iron, or the like by employing a conventionally known plating method on the inner wall of the through hole 5. It is formed by depositing a material and then processing it into a predetermined pattern.

The substrate 1 having the conductive layer 6 on the inside, the upper and lower surfaces, and the inner wall of the through hole 5 is formed by impregnating an organic resin such as an epoxy resin with an aramid fiber whose surface is coated with polytetrafluoroethylene. A plurality of aramid substrates are vertically stacked and integrated, and their relative dielectric constant is as small as 4 (room temperature, 1 MHz) or less, so that the propagation speed of electric signals transmitted through the conductive layer 6 can be increased. As a result, it becomes possible to mount a high-speed driven semiconductor element or the like that transmits electric signals at high speed.

The substrate 1 has an aramid fiber impregnated in an organic resin such as an epoxy resin having an impregnation rate of 10% by weight.
If it is less than 60%, the relative permittivity of the substrate 1 cannot be reduced, and if it exceeds 60% by weight, a gap is formed between the aramid fiber and the organic resin, and the conductive layer 6 disposed inside the substrate 1
There is a tendency for the reliability of electrical insulation between the two to decrease.
Accordingly, the substrate 1 is provided with an aramid fiber impregnated in an organic resin such as an epoxy resin in order to maintain the electrical insulation of the conductive layer 6 disposed inside the substrate 1 and reduce the relative dielectric constant. It is preferable that the ratio be in the range of 10 to 60% by weight.

Further, the aramid fiber impregnated in the organic resin has a large number of water-permeable functional groups (ester compounds), so that a large amount of water easily adheres thereto. An electric short circuit occurs between the layers 6. Therefore, it is necessary to coat the surface of the aramid fiber impregnated in the organic resin with polytetrafluoroethylene to effectively prevent a large amount of water from adhering to the aramid fiber.

As a method of coating the surface of the aramid fiber with polytetrafluoroethylene, for example, a suspension is prepared by dispersing a polytetrafluoroethylene powder in petroleum naphtha or the like, and the suspension is formed with aramid. This is carried out by immersing the fiber, followed by a heat treatment at a temperature of about 100 to 200 ° C. to scatter petroleum naphtha and the like.

Further, when the thickness of each aramid substrate constituting the substrate 1 is less than 20 μm, the reliability of the electrical connection between the conductive layers 6 disposed inside the substrate 1 tends to decrease. When the thickness exceeds 200 μm, when the conductive layer 6 disposed inside the substrate 1 is electrically connected via a through-hole conductor filled in the through-hole formed in the aramid substrate, the through-hole is formed by laser processing or the like. Therefore, it tends to be difficult to form a predetermined size and a predetermined shape. Therefore, it is preferable that each aramid substrate constituting the substrate 1 has a thickness in a range of 20 to 200 μm.

Further, the substrate 1 in which the conductive layer 6 is formed on the inside, the upper and lower surfaces, and the inner wall of the through hole 5 is provided with the through hole 5.
Is filled with an organic resin filler 8 made of epoxy resin or the like, and the through hole 5 is completely filled with the organic resin filler 8. And the same plane as the surface of the conductive layer 6 formed on the substrate.

The organic resin filler 8 is used when forming a multilayer wiring portion 4 comprising an organic resin insulating layer 2 and a thin film wiring conductor layer 3 on the upper surface and / or lower surface of the substrate 1. It serves to maintain the flatness of the resin insulating layer 2 and the thin-film wiring conductor layer 3, and fills the through-hole 5 of the substrate 1 with a precursor such as an epoxy resin.
Is applied for 0.5 to 3 hours to completely fill the inside of the through-hole 5 of the substrate 1 by thermosetting.

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 multilayer wiring section 4 functions to electrically insulate the thin film wiring conductor layers 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 organic resin such as an epoxy resin, a bismaleimide triazine resin, a polyphenylene ether resin, a fluororesin, and the like. A novolak type epoxy resin, a glycidyl ester type epoxy resin, and the like are mixed with a curing agent such as an amine-based curing agent, an imidazole-based curing agent, and an acid anhydride-based curing agent to obtain a paste-like epoxy resin precursor, and the epoxy resin is obtained. The precursor is applied to the upper portion of the substrate 1 by spin coating, and then the precursor is applied at about 80 ° C. to 20 ° C.
It is formed by treating with heat of 0 ° C. for 0.5 to 3 hours and heat curing.

The organic resin insulating layer 2 has a through hole 9 having a minimum diameter of about 1.5 times the thickness of the organic resin insulating layer 2 at each predetermined position. Serves as a forming hole for forming a through-hole conductor 10 that electrically connects each of the thin film wiring conductor layers 3 located above and below the organic resin insulating layer 2 described later.

The through holes 9 provided in the organic resin insulating layer 2 are formed at predetermined positions by, for example, a photolithography technique, specifically, applying a resist material onto the organic resin insulating layer 2 and exposing and developing the resist material. 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 ( A through hole is formed, 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 10 is provided on the inner wall of a through hole 9 provided in each organic resin insulating layer 2. Each of the thin-film wiring conductor layers 3 positioned above and below the organic resin insulating layer 2 with the through-hole conductor 10 therebetween is electrically connected.

The thin-film wiring conductor layer 3 and the through-hole conductor 10 provided on the upper surface of the organic resin insulating layer 2 and in the through-hole 9 are made of a metal material such as copper, nickel, gold, or aluminum by electroless plating or vapor deposition. Method, is formed by employing a thin film forming technology such as a sputtering method and an etching technology, for example, when formed of copper,
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 9. 1 µm to 40 µm using a 1 liter electroless copper plating bath
m, and then the copper layer is processed into a predetermined pattern by an etching technique to be disposed between the organic resin insulating layers 2 and on the inner walls of the through holes 9 of the organic resin insulating layers 2. You. In this case, the thin film wiring conductor layer 3
Since is formed by a thin film forming technique, the wiring can be miniaturized, and thereby the thin film wiring conductor layer 3 can be formed at an extremely high density. At the same time, in the thin film wiring conductor layer 3, the organic resin insulating layer 2 is formed of an organic resin such as an epoxy resin, a bismaleimide triazine resin, a polyphenylene ether resin, and a fluororesin, and has a relative dielectric constant of 4 (room temperature, 1 MHz) or less. And the propagation speed of the electric signal can be extremely high,
This also makes it possible to mount a high-speed driven semiconductor element or the like that needs to transmit electric signals at high speed.

The multilayer wiring section 4 formed by alternately laminating the organic resin insulating layers 2 and the thin film wiring conductor layers 3 in a multilayer manner has a center line average roughness (R
If a rough surface of 0.05 μm ≦ Ra ≦ 5 μm is set in a), the bonding between the organic resin insulating layer 2 and the thin-film wiring conductor layer 3 and the bonding between the organic resin insulating layers 2 located above and below can be made strong. it can. Accordingly, the corner organic resin insulating layer 2 of the multilayer wiring portion 4 is roughened on its upper surface by employing an etching technique or the like, and has a center line average roughness (Ra) of 0.0.
It is preferable to provide a rough surface of 5 μm ≦ Ra ≦ 5 μm.

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 500 when 1 μm ≦ Pc ≦ 10 μm.
2500 μm of 1 μm ≦ Pc ≦ 1 μm, 0.01 μm
If ≦ Pc ≦ 0.1 μm is set to 12,500 or more, the bonding between the organic resin insulating layer 2 and the thin-film wiring conductor layer 3 and the bonding between the organic resin insulating layers 2 located above and below become stronger. Therefore, the organic resin insulating layer 2 has a thickness of 2.5
The count value of the height (Pc) of the unevenness in the length of mm is 1 μm ≦ Pc ≦ 10 μm.
2500 or more m ≦ Pc ≦ 1 μm, 0.01 μm ≦ P
It is preferable that c ≦ 0.1 μm is set to 12,500 or more.

The count value of the center line average roughness (Ra) of the upper surface of the organic resin insulating layer 2 and the height of the unevenness (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 calculated from the measurement result.

The center line average roughness (Ra) is 0.0
5 μm ≦ Ra ≦ 5 μm, the count value of the height (Pc) of the unevenness 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 performing reactive ion etching by spraying a gas such as CHF ₃ , CF ₄ , or Ar on the upper surface of the organic resin insulating layers 2. You.

Further, when the thickness of each of the organic resin insulating layers 2 exceeds 100 μm, the processing time of etching becomes long when the through holes 9 are formed by employing photolithography technology in the organic resin insulating layers 2. It is difficult to form the through hole 9 into a desired clear shape, and if the thickness is less than 5 μm, rough surface processing for increasing the bonding strength of the organic resin insulating layer 2 positioned above and below the organic resin insulating layer 2 is performed. At the time of application, there is a risk that an unnecessary hole is formed in the organic resin insulating layer 2 and an unnecessary electric short circuit is caused in the thin film wiring conductor layer 3 located above and below. Accordingly, the organic resin insulating layer 2 has a thickness of 5 μm to 10 μm.
It is preferable to set the range to 0 μm.

Further, when the thickness of each thin-film wiring conductor layer 3 of the multilayer wiring portion 4 is less than 3 μm, the electric resistance of the thin-film wiring conductor layer 3 becomes large, and a predetermined value is applied to each thin-film wiring conductor layer 3. It is difficult to transmit an electric signal. If the thickness exceeds 40 μm, a large stress is present inside the thin-film wiring conductor layer 3 when the thin-film wiring conductor layer 3 is applied to the organic resin insulating layer 2. Thereby, the thin film wiring conductor layer 3 is easily peeled off from the organic resin insulating layer 2. 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 3 μm to 40 μm.

Thus, according to the multilayer wiring board of the present invention, the electronic component A such as a semiconductor element, a capacitance element, and a resistor is mounted and mounted on the multilayer wiring section 4 attached to the upper surface of the substrate 1. By electrically connecting each of the electrodes A to the thin film wiring conductor layer 3, a semiconductor device or a hybrid integrated circuit device is obtained. If the conductive layer 6 formed on the substrate 1 is connected to an external electric circuit, the semiconductor device or the hybrid integrated circuit device can be obtained. The circuit device is 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 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. .

[0042]

According to the multilayer wiring board of the present invention, the substrate is formed by impregnating an organic resin with an aramid fiber whose surface is coated with polytetrafluoroethylene in an amount of 10 to 60% by weight. Has a small value of 4 (room temperature, 1 MHz) or less, whereby the propagation speed of the electric signal transmitted through the conductive layer formed on the substrate can be made high, and the high speed at which the electric signal needs to be transmitted at a high speed can be obtained. It is possible to mount a driving semiconductor element or the like.

Further, according to the multilayer wiring board of the present invention, since a part of the wiring conductor is formed on the substrate by a thin film forming technique, the wiring conductor can be miniaturized. It can be formed.

[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 layer 4 ... Multilayer wiring part 5 ... Through-hole 6 ... Conductive layer 9 ... Through-hole 10 ... Through Hall conductor

Claims (2)

[Claims] 1. A multi-layer wiring section comprising an organic resin insulating layer and a thin-film wiring conductor layer alternately laminated in multiple layers on a substrate having a conductive layer, and the conductive layer and the thin-film wiring conductor layer are electrically connected to each other. Wherein the substrate is formed by impregnating an organic resin with an aramid fiber whose surface is covered with polytetrafluoroethylene. 2. The multilayer wiring board according to claim 1, wherein the impregnation rate of the aramid fiber in the organic resin is 10 to 60% by weight.