JPH0655478B2 - Method for manufacturing ceramic coat laminate - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for manufacturing a laminated board for a printed circuit board.

(Prior Art) Conventionally, a phenol resin laminated board and an epoxy resin laminated board have been often used as a printed circuit board. However, recently, with higher performance and smaller size of electronic devices, high-density packaging is desired, and how to deal with heat generation caused by the high density mounting has become a problem.

On the other hand, conventional organic substrates have poor thermal conductivity and thus lack heat dissipation, and have a large coefficient of thermal expansion and poor heat resistance, making it difficult to achieve high-density mounting. Therefore, attention is focused on a ceramic substrate such as alumina or a metal core substrate whose surface is covered with an insulating layer using a metal plate as a core material. Also, from the viewpoint of heat resistance, a substrate using a heat resistant thermoplastic resin such as polyimide resin or polyether ether ketone or polysulfone has been actively developed in place of the conventional phenol resin or epoxy resin substrate.

(Problems to be Solved by the Invention) However, there are various problems with these substrates. That is, although ceramic substrates such as alumina and silicon carbide have excellent thermal conductivity and heat resistance, the manufacturing process is complicated, the processability is poor, the mechanical strength is low, the size of the substrate is limited, and the size is large. However, there is a defect that the substrate cannot be obtained. In addition, since the metal core substrate using the metal plate as the core material is in contact with the conductor part that becomes the circuit because of the insulating layer made of the resin having low thermal conductivity, the high thermal conductivity of the metal core cannot be fully utilized, and The radiation is not sufficient. Further, since the core material is a metal plate, it is not easy to form through holes, and a very complicated manufacturing process is required.

Furthermore, although the heat resistant resin substrate has improved heat resistance,
The heat dissipation effect cannot be expected due to the low thermal conductivity of the resin.

The present invention provides a manufacturing method that improves these drawbacks, enables the same manufacturing and processing methods as those of conventional organic substrates, and has excellent thermal conductivity and heat resistance and a substrate having a low coefficient of thermal expansion at a low cost. It is a thing.

(Means for Solving Problems) That is, according to the present invention, a copper foil having a layer containing nickel as a main component on one surface thereof is electrically sprayed with an electrically insulating ceramic to form a ceramic layer. It is characterized in that a prepreg is laminated so as to be in contact with the ceramic layer side of the foil, thermocompressed and integrated to provide a ceramic layer between the copper foil and the organic substrate.

Use a copper foil with a layer containing nickel as the main component on one side, and spray the electrically insulating ceramic on the layer containing nickel as the main component in order to improve the adhesion between the copper foil and the ceramic. Is. Generally, when a ceramic is sprayed on a metal, the adhesion between the metal and the ceramic differs depending on the type of the metal to be sprayed, and it is said that the adhesion when sprayed on copper is low. The cause of this is that the copper is easily deteriorated, an oxide layer is easily generated on the surface, the layer is easily peeled from the base material, or the mechanical strength is low, or copper is very soft and therefore the surface before spraying It is considered that it is difficult to form a rough surface that exerts an anchor effect in the plast treatment for roughening, or the rough surface generated by the plast treatment is damaged by the collision of the ceramic molten particles at high speed during thermal spraying. ing.

On the other hand, when ceramics are sprayed, nickel is said to have excellent close packing property. Therefore, if nickel foil is used instead of copper foil, sufficient adhesion can be obtained, but nickel has higher electrical resistance than copper, and therefore nickel foil can be used for special purposes. However, it becomes less versatile. Therefore, by providing a layer mainly containing nickel on one surface of the copper foil and spraying ceramic on the surface, the adhesion between the copper foil and the ceramic layer and the electrical characteristics of the circuit forming material are compatible for the first time.

The layer containing nickel as a main component provided on one surface of the copper foil is not only nickel alone but also nickel and aluminum,
Alloys with metals such as copper, iron, zinc and tin are also acceptable. Further, the thickness thereof does not define the range of the present invention, and it may be as thin as about 1 μm or thick as long as it does not adversely affect conductivity such as electric resistance. The method for forming the layer containing nickel as a main component on the copper foil may be a plating method, a CVD method, a PVD method, a thermal spraying method, or a laminated so-called clad foil may be used.

Alumina, which is most widely used as a ceramic substrate, is suitable as the ceramic sprayed on the copper foil in the present invention, but other electrically insulating ceramics such as spinel, mullite, beryllia, silicon carbide, and aluminum nitride are used. To be As the ceramic spraying method, a glass spraying method, a plasma spraying method, a water plasma spraying method, a reduced pressure plasma spraying method, or the like can be applied.

Next, the resin of the prepreg is preferably an epoxy resin or a polyimide resin from the viewpoint of electrical characteristics and molding processability, but in addition, a thermosetting resin such as a phenol resin, an unsaturated polyester resin, a melamine resin or a vinyl ester resin, or Thermoplastic resins such as polysulfone, polyetheretherketone, polyethersulfone, and polyetherimide can be used. In addition to commonly used glass fiber, Kepler fiber, paper, Sic
Fibers, silica fibers and the like can be used.

(Operation) Since the laminated plate obtained by the method of the present invention has the ceramic layer on the surface of the organic substrate, it is excellent in heat dissipation and heat resistance and has a small coefficient of thermal expansion. Further, the circuit can be easily formed by forming a resist layer on the copper foil on the surface and performing an etching process, similarly to the conventional copper-clad laminate, and the formation of the through hole is also performed by the conventional organic material. It can be performed in the same manner as the substrate.

Also, a copper foil having a layer containing nickel as a main component on one side is used, and since a ceramic is sprayed on the layer containing nickel as a main component, a substrate having excellent adhesion and high reliability can be obtained. it can. Further, it is generally said that ceramics, which are inorganic substances, and plastics, which are organic substances, have poor affinity, and thus it is said that sufficient adhesion cannot be obtained. When thermocompression molding is performed, since the sprayed layer has a rough surface and pores also exist, the sprayed and low-viscosity resin penetrates into the gaps to increase the adhesion area. Therefore, sufficient adhesion can be obtained.
In addition, since the ceramic sprayed layer has more pores than the sintered ceramic, there is a problem in electrical insulation when absorbing moisture as it is. However, according to the method of the present invention, the pores are also sealed by the resin. Therefore, the problem can be solved.

Hereinafter, the present invention will be described with reference to examples.

(Example) FIG. 1 is a laminated constitutional view of a ceramic sprayed copper foil and a prepreg, and FIG. 2 is a schematic sectional view of the obtained laminated plate.

35μ thickness with nickel plating of about 3μ on one side
After the nickel plating layer 2 of the copper foil 1 was subjected to plast treatment, alumina was sprayed by plasma spraying to a thickness of about 100 μm to form an alumina sprayed layer 3.

The alumina sprayed copper foil and the glass cloth / epoxy resin impregnated prepreg 4 were stacked in the laminated structure shown in FIG. 1 and thermocompression-molded to obtain a laminated plate having the structure shown in FIG.

The thus obtained laminate has an alumina layer on the surface of the glass fiber base epoxy resin 5, and further has a copper foil layer on the surface thereof. The copper foil and the alumina layer, and the alumina layer and the epoxy layer. The adhesion between the resin layers was good, and it was possible to form circuits and through holes by etching in the same manner as in the general glass fiber-based epoxy resin copper-clad laminate.

In addition, it has excellent heat dissipation due to the presence of an alumina layer with good thermal conductivity in contact with the circuit, and also has good heat resistance.Because alumina is a low thermal expansion material, the coefficient of thermal expansion of the laminated plate is also conventional. I was able to make it smaller.

(Effects of the Invention) By the method of the present invention, a laminate having a ceramic layer on the surface of a conventional organic substrate as a base can be easily manufactured at low cost. The laminated plate obtained by the present invention has excellent characteristics, and post-processing such as circuit formation and through hole formation can be performed in the same manner as in conventional organic substrates. The problem of the substrate can be solved.

[Brief description of drawings]

FIG. 1 is a laminated constitution diagram of a ceramic sprayed copper foil and a prepreg, and FIG. 2 is a schematic sectional view of a laminated material obtained by the present invention. Explanation of symbols 1 ... Copper foil, 2 ... Nickel plating layer 3 ... Alumina sprayed layer, 4 ... Prepreg 5 ... Glass fiber base epoxy resin

Claims (5)

[Claims] 1. A ceramic foil is formed by spraying a ceramic on a copper foil having a layer containing nickel as a main component on one surface, and a prepreg is laminated so as to be in contact with the ceramic layer side of the copper foil. A method for producing a ceramic-coated laminated sheet, which comprises performing thermocompression molding. 2. The method for producing a laminated plate according to claim 1, wherein the ceramic contains alumina as a main component. 3. The method for producing a laminated board according to claim 1, wherein the resin of the prepreg is an epoxy resin. 4. The method for producing a laminated board according to claim 1, wherein the prepreg resin is a polyimide resin. 5. The method for producing a laminated board according to claim 1, wherein the fibers of the prepreg are glass fibers.