JP4328007B2 - Manufacturing method of multilayer wiring board - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The invention you about the method for manufacturing a multilayer wiring board.
[0002]
[Prior art]
Conventionally, a multilayer wiring board used for a hybrid integrated circuit device, a package for housing a semiconductor element, and the like includes a thin insulating layer and a wiring conductor layer on the substrate for the purpose of forming wiring conductors at a high density. A multilayer wiring board in which a multilayer wiring portion is formed has been adopted.
[0003]
Such a multilayer wiring board has a thin film insulating layer made of a polyimide resin or the like formed by a spin coating method on the upper surface of a substrate made of an aluminum oxide sintered body, a main conductor such as copper or aluminum, and the upper and lower sides thereof. A structure composed of barrier conductors such as chrome and nickel, and multilayer wiring conductor layers that are formed by adopting thin film formation technology such as plating and vapor deposition and photolithography technology. have.
[0004]
However, when an insulating layer made of polyimide resin is formed by a spin coating method, a polyimide resin precursor is applied in multiple steps to form an insulating layer with a desired thickness, and the polyimide resin precursor is applied to polyimide. Therefore, there is a problem that the manufacturing process becomes long.
[0005]
Therefore, a multilayer wiring board in which a plurality of insulating film layers made of polyimide resin or the like and having a wiring conductor layer formed on the upper surface are bonded with an insulating adhesive layer made of bismaleimide resin or the like has been adopted in multiple layers. Yes.
[0006]
In order to form such a multilayer wiring board, first, an insulating film is prepared by applying an insulating adhesive using a doctor blade method or the like and dried, and the insulating film layer is formed on a substrate or a lower layer on which a wiring conductor is formed. The insulating film layer is stacked so that an insulating adhesive layer is disposed on the upper surface of the insulating film layer, and this is heated and pressed using a heating press device and bonded.
[0007]
According to this multilayer wiring board, the curing process for converting the polyimide resin precursor into a polyimide can be reduced, and the multilayer wiring board has a short manufacturing process.
[0008]
However, in this multilayer wiring board, the upper surfaces of the wiring conductor layer and the insulating film layer are chemically roughened with a processing solution in order to ensure the adhesive strength between the wiring conductor layer and the insulating film layer.
[0009]
For this reason, the upper surface of the wiring conductor layer or the insulating film layer becomes a rough surface having irregularities, and in the thin wiring conductor layer, over-etching may occur in the irregularity forming process, and the wiring conductor layer may be thinned. There was a problem that it was impossible.
[0010]
Therefore, a multilayer wiring board in which a plurality of insulating film layers made of an organic resin and having a wiring conductor layer formed on the upper surface are bonded with an insulating adhesive layer through a coupling agent layer and laminated in multiple layers has been adopted. Yes.
[0011]
According to this multilayer wiring board, since the adhesive strength between the wiring conductor layer and the insulating film layer can be obtained without roughening the upper surface of the wiring conductor layer, the wiring conductor layer can be thinned.
[0012]
[Problems to be solved by the invention]
However, in a multilayer wiring board using a coupling agent layer, a part of the coupling agent layer evaporates due to heat treatment at the time of forming a wiring conductor layer or mounting a chip component, and the insulating film layer swells. There was a problem.
[0013]
The present invention has been made in view of the above problems in the prior art, and an object of the present invention is to provide a multilayer wiring board in which the insulating film layer does not swell due to heat treatment and the insulating film layer has a strong adhesive strength. It is in.
[0014]
[Means for Solving the Problems]
The method for producing a multilayer wiring board of the present invention includes a step of forming a wiring conductor layer on the first insulating film layer, a step of forming a coupling agent layer on the wiring conductor layer by an immersion method, and a solvent. A step of dissolving and washing the surface of the coupling agent layer so that the coupling agent layer has a thickness of 5 molecular layers or less ; and an insulating adhesive on the coupling agent layer from which the surface has been washed. And a step of forming a second insulating film layer through the step.
[0017]
According to the multilayer wiring board of the present invention, since the coupling agent layer is formed on the upper surface of the wiring conductor layer to have a thickness of 5 molecular layers or less, the coupling agent layer has a small molecular disorder, and the wiring conductor layer and The molecules of the coupling agent layer are efficiently bonded to form a uniform and strong layer, and no isolated coupling agent molecules are generated. As a result, the heat resistance of the coupling agent layer is improved, the evaporation of the coupling agent layer in the heating process is eliminated, and the wiring conductor layer and the insulating adhesive layer are firmly bonded by the coupling agent layer.
[0018]
Thereby, the multilayer wiring board with strong adhesive strength of the insulating film layer which does not produce the swelling of an insulating film layer can be formed.
[0019]
Furthermore, according to the multilayer wiring board of the present invention, when the coupling agent layer is formed to have a thickness of five molecular layers or less on the upper surface other than the portion where the wiring conductor layer of the insulating film layer is formed, the coupling agent The layers are also less disturbed in the arrangement of molecules, and the molecules of the insulating film layer and the coupling agent layer are efficiently combined to form a uniform and strong layer, and no molecules of the isolated coupling agent layer are generated. As a result, the heat resistance of the coupling agent layer is improved, the evaporation of the coupling agent layer in the heating process is eliminated, and the wiring conductor layer and the insulating adhesive layer are firmly bonded by the coupling agent layer and the insulating film The layer and the insulating adhesive layer are also firmly bonded by the coupling agent layer.
[0020]
Thereby, the multilayer wiring board with stronger adhesive strength of the insulating film layer which does not cause the swelling of the insulating film layer can be formed.
[0021]
Furthermore, according to the multilayer wiring board of the present invention, the wiring conductor layer is made of copper, the insulating film layer is made of polyimide resin, the insulating adhesive layer is made of polyimide siloxane resin, and the coupling agent layer is made of isopropyltri-N-aminoethylaminoethyl titanate. When formed, isopropyltri-N-aminoethylaminoethyl titanate has good wettability with copper, polyimide resin, and polyimidesiloxane resin and is easy to bond firmly, and has a high heat resistance in terms of molecular structure. The adhesive strength between the layers is strengthened, and it is possible to cope with higher temperature heat treatment.
[0022]
As a result, the heat resistance of the coupling agent layer is improved, the evaporation of the coupling agent layer is eliminated even in a higher heating step, and the wiring conductor layer and the insulating adhesive layer are firmly bonded by the coupling agent layer. Thus, it is possible to form a multilayer wiring board having a much stronger adhesive strength of the insulating film layer that does not cause swelling of the insulating film layer even by a higher temperature heat treatment.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the drawings.
[0024]
FIG. 1 is a cross-sectional view showing an example of an embodiment of a multilayer wiring board according to the present invention, and FIG. 2 is an enlarged cross-sectional view of a main part showing a part of the wiring conductor layer.
[0025]
In these drawings, 1 is a substrate, 2 is a multilayer wiring portion, 3 is a wiring conductor layer, 4 is an insulating film layer, 5 is an insulating adhesive layer, and 6 is a coupling agent layer.
[0026]
The substrate 1 is provided with a multilayer wiring portion 2 in which a plurality of insulating film layers 4 having a wiring conductor layer 3 formed on the upper surface thereof are bonded with an insulating adhesive layer 5 and laminated in multiple layers. It functions as a support member that supports the portion 2.
[0027]
The substrate 1 is made of an oxide ceramic such as an aluminum oxide sintered body or a mullite sintered body, or a non-oxide type such as an aluminum nitride sintered body or a silicon carbide sintered body having an oxide film on the surface. It is formed of an electrically insulating material such as ceramics, a glass epoxy resin obtained by impregnating a glass fiber base material with an epoxy resin, or a glass fiber base material impregnated with a bismaleimide triazine resin.
[0028]
For example, when it is formed of an aluminum oxide sintered body, an appropriate organic solvent and solvent are added to and mixed with raw material powders such as alumina, silica, calcia, and magnesia to form a slurry, and this is conventionally known. A ceramic green sheet (green ceramic sheet) is formed by adopting the doctor blade method or the calender roll method, and then the ceramic green sheet is appropriately punched into a predetermined shape and at a high temperature (about 1600 ° C). Or by adding an appropriate organic solvent / solvent to the raw material powder such as alumina to adjust the raw material powder, and forming this raw material powder into a predetermined shape by a press molding machine. Manufactured by firing at high temperature (about 1600 ° C). In the case of glass epoxy resin, for example, it is manufactured by impregnating a base material made of glass fiber with an epoxy resin precursor and thermally curing the epoxy resin precursor at a predetermined temperature.
[0029]
The wiring conductor layer 3 of the multilayer wiring portion 2 disposed on the upper surface of the substrate 1 functions as a transmission path for transmitting electrical signals, and the insulating film layer 4 electrically connects the wiring conductor layers 3 positioned above and below. Has the function of insulation. Further, the insulating film layer 4, the insulating adhesive layer 5, and the coupling agent layer 6 are formed with through holes processed by a laser or the like, and the upper wiring conductor layer 3 extends into the through holes. Thus, a connection path for electrically connecting each of the wiring conductor layers 3 positioned above and below the insulating film layer 4 is formed.
[0030]
The wiring conductor layer 3 disposed in the upper surface of each insulating film layer 4 and in the through hole is formed by sputtering or vapor deposition of a metal material such as copper, gold, silver, aluminum, nickel, chromium, molybdenum, titanium, tantalum, or tungsten. It is formed by adopting a thin film forming technique such as a method / plating method and an etching processing technique.
[0031]
For example, the wiring conductor layer 3 is formed by first depositing copper in a large area and depositing chromium, molybdenum, titanium or the like as a diffusion prevention layer (barrier layer) under the copper layer. Next, a photoresist is formed in a desired pattern thereon, and unnecessary portions of the conductor layer are removed by etching using the photoresist as a mask to be processed into a desired pattern.
[0032]
A coupling agent layer 6 is formed on the upper surface of the wiring conductor layer 3. This coupling agent layer 6 strengthens the adhesive strength with the insulating adhesive layer 5 and functions as a layer for improving the adhesive strength in the heat treatment.
[0033]
This coupling agent layer 6 is composed of N-β (aminoethyl) γ-aminopropyltrimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-β (aminoethyl) γ-aminopropyltrimethoxysilane, vinyl. Triethoxysilane, Vinyltris (β-methoxyethoxy) silane, γ-methacryloxypropyltrimethoxysilane, N-β (aminoethyl) γ-aminopropylmethyldimethoxysilane, γ-chloropropyltrimethoxysilane, γ-aminopropyltriethoxy Silane, isopropyltridodecylbenzenesulfonyl titanate, isopropyltris (dioctylpyrophosphate) titanate, dicumylphenyloxyacetate titanate, isopropyltri-N-aminoethylaminoethyl titanate, isopropyl As a method for forming the coupling agent layer 6, the spin coating method, the dipping method, and the like may be used. However, in order to improve the uniformity of the film, it is preferable to use the LB film method.
[0034]
When the coupling agent layer 6 is formed by using the LB film method, for example, the coupling agent is dispersed on the liquid surface in a desired thickness while keeping the surface pressure constant, and the wiring is perpendicular to the film surface. By immersing the substrate 1 on which the conductor layer 3 is formed and slowly pulling it up as it is, the coupling agent layer 6 is formed on the entire surface of the substrate 1 with a uniform thickness.
[0035]
At this time, when the thickness of the coupling agent layer 6 is greater than the thickness of the five molecular layers, the coupling agent layer becomes more disordered in the arrangement of molecules, and the number of isolated coupling agent molecules increases. Since a part of the layer tends to evaporate and the insulating film layer 4 tends to swell, the thickness of the coupling agent layer 6 is preferably set to a thickness of 5 molecular layers or less. Incidentally, the size of one molecule of the coupling agent is about 2 nm, and the thickness of the five molecular layers is about 10 nm. Even when the thickness of the coupling agent layer 6 does not become a uniform 5 molecular layer, the occupancy rate of the portion of the coupling agent layer 6 with a thickness of 1/3/5 molecular layer is particularly 60%. If it is above, there exists an improvement effect of adhesive strength.
[0036]
Furthermore, if the coupling agent layer 6 is formed on the upper surface of the insulating film layer 4 other than the portion where the wiring conductor layer 3 is formed, the adhesive strength between the lower insulating film layer 4 and the insulating adhesive layer 5 is also improved. It becomes stronger and does not cause swelling of the insulating film layer 4 in the heat treatment. Furthermore, even in an environmental resistance test such as a high-temperature and high-humidity bias test, the occurrence of electromigration or the like generated between the wiring conductor layers 3 in the same plane is prevented, and the environmental resistance reliability is improved.
[0037]
At this time, when the thickness of the coupling agent layer 6 is greater than the thickness of the five molecular layers, the coupling agent layer becomes more disordered in the arrangement of molecules, and the number of isolated coupling agent molecules increases. Since a part of the layer tends to evaporate and the insulating film layer 4 tends to swell, the thickness of the coupling agent layer 6 is preferably set to a thickness of 5 molecular layers or less.
[0038]
Further, the coupling agent layer 6 formed on the insulating film layer 4 may be the same as that formed on the upper surface of the wiring conductor layer 3, but the coupling agent layer 6 may be changed to a different type of coupling agent depending on the combination of materials to be bonded. May be.
[0039]
Further, the combination of materials of the wiring conductor layer 3, the insulating film layer 4, and the insulating adhesive layer 5 may be appropriately selected according to specifications and characteristics required for the multilayer wiring board. Copper, insulating film layer 4 is formed of polyimide resin, insulating adhesive layer 5 is formed of polyimide siloxane resin, and coupling agent layer 6 is formed of isopropyltri-N-aminoethylaminoethyl titanate. Ethyl titanate has good wettability with copper, polyimide resin and polyimide siloxane resin and is easy to bond firmly. Also, isopropyltri-N-aminoethylaminoethyl titanate has high heat resistance in molecular structure. Strength can be strengthened and higher temperature heat treatment can be supported.
Thereby, the adhesive strength of the insulating film layer which does not cause the swelling of the insulating film layer even by a higher temperature heat treatment becomes even stronger.
[0040]
In the uppermost wiring conductor layer 3 of the insulating film layer 4, a nickel layer or a gold layer may be formed by plating on the copper layer for the wiring conductor layer 3 from the viewpoint of the mountability and environmental resistance of the chip component. .
[0041]
The insulating layer of the multilayer wiring portion 2 is composed of an insulating film layer 4 and an insulating adhesive layer 5, and the insulating film layer 4 is made of polyimide resin, epoxy resin, polyphenylene sulfide resin, polyquinoline resin, polyphenylene ether resin, or the like.
[0042]
The insulating adhesive layer 5 is made of polyamideimide resin, polyimidesiloxane resin, bismaleimide resin, epoxy resin, or the like.
[0043]
For example, when the insulating film layer 4 is a polyimide resin and the insulating adhesive layer 5 is a polyimide siloxane resin, it is formed as follows.
[0044]
The insulating layer is formed by first applying a polyimide siloxane resin, which is an insulating adhesive, to a polyimide resin, which is an insulating film having a thickness of about 12.5 to 50 μm, using a doctor blade method or the like to a dry thickness of about 5 to 20 μm. The insulating film layer 4 is prepared so that the insulating adhesive layer 5 is disposed between the wiring conductor layer 3 on which the coupling agent layer 6 is formed and the upper surface of the lower insulating film layer 4. They are stacked and bonded by applying heat and pressure using a heating press.
[0045]
Thus, according to the multilayer wiring board of the present invention, an electronic component such as a semiconductor element, a capacitive element, or a resistor is mounted and mounted on the multilayer wiring portion 2 disposed on the upper surface of the substrate 1, and each electrode of the electronic component is mounted. Is electrically connected to the wiring conductor layer 3 to obtain a semiconductor device, a hybrid integrated circuit device, or the like.
[0046]
In addition, this invention is not limited to the example of said embodiment, A various change is possible if it is the range which does not deviate from the summary of this invention.
[0047]
For example, in the above-described example, the LB film method is used as the method for forming the coupling agent layer 6. However, when the immersion method is used, the substrate 1 on which the wiring conductor layer 3 is formed is coupled. The coupling agent layer 6 having a desired thickness can be formed by immersing in the agent solution and further washing with a solvent.
[0048]
【The invention's effect】
As described above, according to the multilayer wiring board of the present invention, the coupling agent layer is formed on the upper surface of the wiring conductor layer to have a thickness of 5 molecular layers or less. The molecules of the wiring conductor layer and the coupling agent layer are efficiently bonded to form a uniform and strong layer, and no isolated coupling agent molecules are generated. As a result, the heat resistance of the coupling agent layer is improved, the evaporation of the coupling agent layer in the heating process is eliminated, and the wiring conductor layer and the insulating adhesive layer are firmly bonded by the coupling agent layer.
[0049]
Thereby, the multilayer wiring board with strong adhesive strength of the insulating film layer which does not produce the swelling of an insulating film layer can be formed.
[0050]
Furthermore, according to the multilayer wiring board of the present invention, when the coupling agent layer is formed to have a thickness of five molecular layers or less on the upper surface other than the portion where the wiring conductor layer of the insulating film layer is formed, the coupling agent The layers are also less disturbed in the arrangement of molecules, and the molecules of the insulating film layer and the coupling agent layer are efficiently combined to form a uniform and strong layer, and no molecules of the isolated coupling agent layer are generated. As a result, the heat resistance of the coupling agent layer is improved, the evaporation of the coupling agent layer in the heating process is eliminated, and the wiring conductor layer and the insulating adhesive layer are firmly bonded by the coupling agent layer and the insulating film The layer and the insulating adhesive layer are also firmly bonded by the coupling agent layer.
[0051]
Thereby, the multilayer wiring board with stronger adhesive strength of the insulating film layer which does not cause the swelling of the insulating film layer can be formed.
[0052]
Furthermore, according to the multilayer wiring board of the present invention, the wiring conductor layer is made of copper, the insulating film layer is made of polyimide resin, the insulating adhesive layer is made of polyimide siloxane resin, and the coupling agent layer is made of isopropyltri-N-aminoethylaminoethyl titanate. When formed, isopropyltri-N-aminoethylaminoethyl titanate has good wettability with copper, polyimide resin, and polyimidesiloxane resin and is easy to bond firmly, and also has high heat resistance in terms of molecular structure. The adhesive strength between the layers is strengthened, and it is possible to cope with higher temperature heat treatment. As a result, the heat resistance of the coupling agent layer is improved, the evaporation of the coupling agent layer is eliminated even at a higher heating step, and the wiring conductor layer and the insulating adhesive layer are firmly bonded by the coupling agent layer. Thus, it is possible to form a multilayer wiring board having a stronger adhesive strength of the insulating film layer that does not cause swelling of the insulating film layer even by a higher temperature heat treatment.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an example of an embodiment of a multilayer wiring board according to the present invention.
FIG. 2 is an enlarged sectional view of a main part showing a part of a wiring conductor layer of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Substrate 2 ... Multi-layer wiring part 3 ... Wiring conductor layer 4 ... Insulating film layer 5 ... Insulating adhesive layer 6 ... Coupling agent layer

Claims (1)

Forming a wiring conductor layer on the first insulating film layer;
A step of forming a coupling agent layer on the wiring conductor layer by an immersion method;
Dissolving and washing the surface of the coupling agent layer using a solvent so that the coupling agent layer has a thickness of 5 molecular layers or less ;
Forming a second insulating film layer on the coupling agent layer, the surface of which has been cleaned, with an insulating adhesive interposed therebetween, and a method for producing a multilayer wiring board.

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