JPH1092879A - Multilayer wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form wiring conductors at a high density and surely and tightly electrically connect semiconductor elements and capacitor elements to the wiring conductors by providing dummy pads facing bonding pads on the bottom of a topmost org. resin insulation layer. SOLUTION: Org. resin insulation layers 2 and thin film wiring conductors 3 are alternately laminated to form a multilayer wiring 4 provided with bonding pads 7 on the top surface of the topmost org. resin insulation layer 2a. The pads 7 are electrically connected to the wiring conductors 3. On the bottom surface of the topmost org. resin insulation layer 2a, dummy pads 8 facing the bonding pads 7 are disposed to effectively block the topmost insulation layer 2a from being recessed, thereby surely and tightly electrically connecting the electrodes of active components such as semiconductor elements and passive components such as capacitor elements and resistor elements to the bonding pads 7.

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. This is a method of sintering and integrating a metal powder and a 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 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, so that miniaturization is difficult, and the wiring conductor is formed at a high density. Had the disadvantage of not being able to do so.

In order to solve the above-mentioned drawbacks, instead of forming the wiring conductor by a conventionally known thick film forming technique, a multilayer wiring board formed by using a thin film forming technique capable of miniaturization is used. It has become.

A multilayer wiring board in which such wiring conductors are formed by a thin film forming technique is made of glass epoxy resin formed by impregnating ceramics made of aluminum oxide sintered body or glass cloth woven with glass fibers with epoxy resin. An insulating layer made of an organic resin such as an epoxy resin formed by spin coating and thermosetting on the upper surface of a substrate made of a metal, such as copper or aluminum, and a thin film forming technique such as an electroless plating method or a vapor deposition method, and photolithography. This technology has a structure in which thin-film wiring conductors formed by adopting the technology are alternately laminated, and thin-film wiring conductors located above and below are electrically connected via through-hole conductors provided in the organic resin insulating layer. A bonding pad electrically connected to the thin film wiring conductor on the upper surface of the uppermost organic resin insulating layer. Formed; then, becomes active component, a capacitor such as a semiconductor element to said bonding pad, a passive component of the electrode of the resistor or the like so as to be connected by thermocompression bonding or the like.

[0008]

However, the multi-layer wiring board formed by alternately laminating the organic resin insulating layers and the thin film wiring conductors has a bonding pad formed on the uppermost organic resin insulating layer. When connecting the electrodes of active components, capacitive elements, passive components such as resistors by thermocompression bonding etc., dents occur in the uppermost organic resin insulating layer,
This has caused a drawback that the electrodes of active components such as semiconductor devices and passive components such as capacitors and resistors cannot be securely and firmly connected to the bonding pads.

The present invention has been made in view of the above-mentioned drawbacks, and has as its object to form a wiring conductor by a thin film forming technique,
It is an object of the present invention to provide a multilayer wiring board that enables a wiring conductor to be formed at a high density and that can securely and firmly electrically connect electrodes of a semiconductor element, a capacitor element, and the like to the wiring conductor.

[0010]

According to the present invention, there is provided a through-hole conductor in which an organic resin insulating layer and a thin film wiring conductor are alternately laminated on a substrate and thin film wiring conductors located above and below are provided on the organic resin insulating layer. A multi-layer wiring board provided with a bonding pad electrically connected to the thin film wiring conductor and connected to an external electronic component on the upper surface of the uppermost organic resin insulating layer. Wherein a dummy pad is provided at a position facing the bonding pad on the lower surface of the uppermost organic resin insulating layer.

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

According to the multilayer wiring board of the present invention, since the dummy pad is provided on the lower surface of the uppermost organic resin insulating layer at a position opposite to the bonding pad to which a semiconductor element, a capacitance element and the like are connected, bonding is performed. When connecting electrodes of active components such as semiconductor elements and the like and capacitive components and passive components such as resistors to the pads by thermocompression bonding or the like, a depression is formed in the uppermost organic resin insulating layer. As a result, it is possible to reliably and firmly electrically connect the electrodes of active components such as semiconductor devices and the like to passive components such as capacitors and resistors to the bonding pads.

[0013]

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

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

The substrate 1 is made of an oxide ceramic such as an aluminum oxide sintered body or a mullite sintered body, or a non-conductive 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 A ceramic green sheet is obtained by adding a suitable organic solvent and a solvent to raw material powders such as alumina, silica, calcia and magnesia to form a slurry by mixing and using a conventionally known doctor blade method or calender roll method. (Ceramic green sheet), and thereafter, 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.

On the upper surface of the substrate 1, a multilayer wiring portion 4 formed by alternately arranging an organic resin insulating layer 3 and thin film wiring conductors 3 in a multilayer is attached.
The organic resin insulating layer 2 has the function of electrically insulating the upper and lower thin film wiring conductors 3, and the thin film wiring conductor 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 polyazide resin, a polyphenylene ether resin, and a fluororesin. For example, when it is made of an epoxy resin, a bisphenol A-type epoxy resin, a novolak-type epoxy resin, a glycidyl ester-type epoxy resin, and an amine-based A curing agent such as a curing agent, an imidazole-based curing agent, and 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 on the substrate 1 by spin coating. After that, this is brought to 80 ° C to 200 ° C.
It 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 5 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 6 that electrically connects each of the thin film wiring conductors 3 located above and below via the through hole.

The through-holes 5 provided in the organic resin insulating layer 2 are formed in the organic resin insulating layer 2 to a predetermined diameter by employing a conventionally known photolithography technique.

A thin-film wiring conductor 3 having a predetermined pattern is provided on the upper surface of each organic resin insulating layer 2, and a through-hole conductor 6 is provided on the inner wall of a through hole 5 provided in each organic resin insulating layer 2. Each of the thin-film wiring conductors 3 located above and below the organic resin insulating layer 2 with the through-hole conductor 6 interposed therebetween is electrically connected.

The thin-film wiring conductor 3 and the through-hole conductor 6 disposed on the upper surface of each organic resin insulating layer and the inner wall of the through-hole 5 are made of a metal material such as copper, nickel, gold, or aluminum by electroless plating or vapor deposition. For example, in the case of being formed of copper, copper sulfate is formed on the upper surface of the organic resin insulating layer 2 and the inner surface of the through hole 5 when the film is formed of copper. An electroless copper plating bath composed of 0.06 mol / l, formalin 0.3 mol / l, sodium hydroxide 0.35 mol / l, and ethylenediaminetetraacetic acid 0.35 mol / l has a thickness of 1 μm to 40 μm. A copper layer is applied, and thereafter, each of the organic layers is processed by processing the copper layer into a predetermined pattern by a photolithography technique. Between fat insulating layer 2, and is disposed in the through hole 5 the inner wall. In this case, since the thin-film wiring conductor 3 and the through-hole conductor 6 are formed by a thin-film forming technique, the wiring can be miniaturized, and thereby the thin-film wiring conductor 3 can be formed at an extremely high density.

The multilayer wiring section 4 formed by alternately arranging the organic resin insulating layers 2 and the thin film wiring conductors 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 thin film wiring conductor 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 portion 4 is roughened by an etching method or the like, so that the center line average roughness (Ra) has a rough surface of 0.05 μm ≦ Ra ≦ 5 μm. .

If the thickness of each of the organic resin insulating layers 2 exceeds 100 μm, the etching processing time becomes longer when the through holes 5 are formed by employing photolithography technology in the organic resin insulating layers 2 to increase the through-holes. It is difficult to form the hole 5 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 an unnecessary hole is formed in the organic resin insulating layer 2 and an unnecessary electrical short circuit occurs in the thin film wiring conductors 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, each thin film wiring conductor 3 of the multilayer wiring portion 4
If the thickness is less than 1 μm, the electrical resistance of each thin-film wiring conductor 3 becomes large, making it difficult to transmit a predetermined electric signal to each thin-film wiring conductor 3.
If the thickness exceeds 0 μm, a large stress is present inside the thin film wiring conductor 3 when the thin film wiring conductor 3 is applied to the organic resin insulating layer 2, and the thin film wiring conductor 3 is separated from the organic resin insulating layer 2 by the large intrinsic stress. It is easy to do. Therefore, the thickness of each thin film wiring conductor 3 of the multilayer wiring part 4 is 1 μm to 40 μm.
It is preferable to keep the range of μm.

The multilayer wiring part 4 formed by alternately arranging the organic resin insulating layers 2 and the thin film wiring conductors 3 in a multilayer is further provided on the upper surface of the uppermost organic resin insulating layer 2a. Dummy pads 8 are provided at positions that are electrically connected to the bonding pads 7 and at positions facing the bonding pads 7 on the lower surface of the uppermost organic resin insulating layer 2a.

The bonding pad 7 is connected to electrodes of active components such as semiconductor elements, capacitors and passive components such as resistors by thermocompression bonding or the like, whereby active components such as semiconductor elements and capacitors, resistors and the like are connected. Are electrically connected to the thin-film wiring conductor 3.

The bonding pad 7 is made of the same metal material as the thin film wiring conductor 2, specifically, a metal material such as copper, nickel, gold, aluminum, etc., and is formed on the uppermost organic resin insulating layer 2 a. Is formed at the same time as the thin film wiring conductor 3 is electrically connected.

On the lower surface of the uppermost organic resin insulating layer 2a, a dummy pad 8 is provided at a position facing the bonding pad 7, and the dummy pad 8 is provided on the bonding pad 7 as an active component such as a semiconductor element. When electrodes of passive components such as a capacitor, a resistor, and a resistor are connected by thermocompression bonding or the like, an effect of effectively preventing dents from being formed in the uppermost organic resin insulating layer 2a is achieved. In addition, the electrodes of active components such as semiconductor devices and passive components such as capacitors and resistors are securely and firmly electrically connected by thermocompression bonding or the like.

The dummy pad 8 is made of, for example, the same metal material as the thin film wiring conductor 3, specifically, copper, nickel, gold,
An organic resin insulating layer 2b formed of a metal material such as aluminum and disposed below the uppermost organic resin insulating layer 2a
The thin film wiring conductor 3 is formed on the upper surface of the substrate and at the same time, a metal layer region which is electrically separated from the thin film wiring conductor 3 is formed in advance, so that the bonding pad 7 is formed on the lower surface of the uppermost organic resin insulating layer 2a. It is arranged at the position facing.

Thus, according to the multilayer wiring board of the present invention,
By connecting active components such as semiconductor devices, passive components such as capacitors, resistors and the like to the bonding pads 7 provided on the surface of the uppermost organic resin insulating layer 2, a semiconductor device or a hybrid integrated circuit device is obtained. Is connected to an external electric circuit, the semiconductor element, the capacitance element, and the like 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 changes can be made without departing from the scope of the present invention. A multilayer wiring portion 4 formed by alternately laminating a plurality of organic resin insulating layers 2 and a plurality of thin film wiring conductors 3 is applied only on the upper surface, but the multilayer wiring portion 4 is provided only on the lower surface side of the substrate 1. Or on both upper and lower main surfaces.

[0032]

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

Further, according to the multilayer wiring board of the present invention, the dummy pad is provided on the lower surface of the uppermost organic resin insulating layer at a position opposite to the bonding pad to which the semiconductor element and the capacitor element are connected. When connecting electrodes of active components such as semiconductor elements and the like and capacitive components and passive components such as resistors to the pads by thermocompression bonding or the like, a depression is formed in the uppermost organic resin insulating layer. As a result, it is possible to reliably and firmly electrically connect the electrodes of active components such as semiconductor devices and the like to passive components such as capacitors and resistors to the bonding pads.

[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 6 ... Through-hole conductor 7 ... Bonding pad 8 ... Dummy pad

Claims (1)

[Claims] 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-hole conductors provided in the organic resin insulating layer. A multilayer wiring board comprising a bonding pad electrically connected to the thin-film wiring conductor on the upper surface of the uppermost organic resin insulating layer and connected to an external electronic component. A multilayer wiring board, wherein a dummy pad is provided on a lower surface of an organic resin insulating layer at a position facing the bonding pad.