JPH0227832B2 - SERAMITSUKUSUKIBAN - Google Patents

Description

[Detailed description of the invention] Industrial applications The present invention relates to ceramic substrates.

Conventional technology and its problems Ceramic substrates in which a conductive layer is formed on a ceramic board have good heat resistance, heat dissipation, etc.
It has excellent properties such as low thermal expansion. The following methods are conventionally known as methods for manufacturing such ceramic substrates.

As a method for forming a conductive layer by wet plating, there is a method in which a ceramic plate is etched with hydrofluoric acid, nitric acid, etc., and then a plating film is formed. However, with this method, the bonding strength of the plating film varies depending on the quality of the ceramic base material, and in the case of ceramics with high chemical resistance, effective etching is difficult and high bonding strength is required. is difficult to obtain.

There is also a method in which powder of a high-melting point metal such as Mo or W is applied onto ceramics and subjected to high temperature treatment (1500 to 1800°C) in a nitrogen atmosphere. in this way,
Although the bonding strength of the conductive layer is high, it has the disadvantage of low productivity because it requires high temperature and atmosphere control.
Furthermore, since direct soldering cannot be performed, a plating process is required, and it also has the disadvantage that it has high resistance as an electrical conductor.

Noble metal powder such as Au, Ag, Pt or Cu, Ni, Al
There is a method in which a so-called thick film conductor paste, which is a mixture of highly conductive base metal powders such as powders, and binder components such as low melting point glass frits mixed and dispersed in an organic vehicle, is coated on ceramics and baked by heating.
This method is expensive for noble metals and has migration problems when used as electrical conductors. Furthermore, in the case of base metals, it is necessary to adjust the atmosphere during heating, making the treatment complicated.

Another method is to place a copper plate of a predetermined shape on ceramics and heat and press it at about 1100 to 1500°C in a nitrogen atmosphere. In addition to being complicated to operate because this method requires atmosphere control,
The thickness of the copper plate needs to be approximately 0.2 to 0.3 mm or more, and there is a drawback that the patterning accuracy of the copper plate is poor.

Means for Solving the Problems In view of the above-mentioned problems, the inventor of the present invention conducted extensive research and found that after applying a glass composition of a specific composition onto ceramics and heat-treating the ceramics,
By forming a plating film on it,
A conductive layer with high bonding strength can be formed on various types of ceramics using a simple method, and the formed conductive layer has the conductive properties, solderability, bonding strength, etc. required for a ceramic substrate. It has been found that this material has good properties and is extremely useful as a ceramic substrate.

That is, the present invention provides () a ceramic base material, () on the ceramic base material, (i) TiN, TiB ₂ , AlN, AlB ₂ , BN, B ₄ C,
At least one powder of SiC and Si ₃ N ₄ 3 ~
80% by weight, (ii) 4-80% by weight of _SiO2 powder, ₍ iii) 1-40% by weight of _B2O3 powder, and (iv) ( _R1 ) _2O , ( _R2 )O, ( _R3) )O ₂ and (R ₄ ) ₂ O ₃ (However, R ₁ is Na, K or L ₁ , R ₂
is Mg, Ca, Ba, Zn, Pb or Cd, _R3 is
A glare base layer obtained by applying and heating a glass composition comprising 1 to 80% by weight of powder of at least one of Ti, Zr, or Mn, and _R4 is Al or Bi;
and () a ceramic substrate comprising a glazed film formed on the base layer.

In the ceramic substrate of the present invention, the ceramic material used may be the same as that of conventional ceramic substrates, and can be selected from ceramic materials that have a heat resistance temperature of 500°C or higher and that have the dielectric constant, insulation properties, dielectric loss tangent, etc. required for the ceramic substrate. It may be selected appropriately depending on the purpose of use, taking into consideration the characteristics. Ceramic materials suitable for use in the present invention include, for example, alumina, zirconia, beryllia, mullite, holsterite, corderite,
Oxide ceramics such as lead titanate, barium titanate, lead zirconate titanate, silicon nitrogen,
Examples include non-oxide ceramics such as aluminum nitride.

To obtain the ceramic substrate of the present invention, first,
A glass composition having a specific composition is applied onto a ceramic substrate and then heat-treated to form a plating base layer.

The glass composition used in the present invention includes (i) TiN, TiB ₂ , AlN, AlB ₂ , BN, B ₄ C, SiC
and 3-80% by weight of at least one powder _{of Si3N4} , (ii) 4-80% by weight of _SiO2 powder, (iii) 1-40% by weight of _B2O3 powder, and ₍ iv) ( _R1 ) ₂ O, (R ₂ ) O, (R ₃ ) O ₂ and (R ₄ ) ₂ O ₃
(However, R ₁ is Na, K or L ₁ , R ₂ is Mg,
It consists of 1 to 80% by weight of at least one powder of Ca, Ba, Zn, Pb or Cd, R ₃ is Ti, Zr, or Mn, and R ₄ is Al or Bi. When the glass composition is coated on ceramics and heated, the non-oxide powder in the composition becomes scattered in the shape of islands in the glass composition, and a plating film is formed thereon. The bonding strength is significantly improved when

In the glass composition used in the present invention, if the blending amount of each component is below the above range, the glass composition may not be vitrified when heated, or the bonding strength may be significantly reduced, Even if it exceeds this value, there is a significant decrease in bonding strength, which is not preferable.

Commercially available components can be used for each component of the glass composition of the present invention, and in particular, the manufacturing method, particle size, etc.
Although the purity is not limited, in order to increase the bonding strength of the bonded body, it is preferable to use a high purity particle, and it is preferable to use a particle size of about 0.1 to 100 μm.

The method for producing the glass composition used in the present invention is not particularly limited, and for example, each component may be simply mixed using a mixer, a light machine, a mill, or the like. In addition, after mixing two or more arbitrarily selected component substances and heating and melting at 700 to 1,600℃ for 10 to 20 minutes, a ball mill etc.
Other component substances may be added and mixed to the powder obtained by grinding to a certain degree.

The method for applying the glass composition is not particularly limited, and the following methods can be exemplified.

(i) Direct application of the composition.

(ii) a method of thermal spraying the composition;

(iii) A method in which the composition is dispersed in a solvent such as alcohol or acetone and then spray painted.

(iv) A method in which the composition is dispersed in an organic vehicle and then the dispersion is applied by brushing, screen printing, spray painting, etc.

As the organic vehicle, for example, a solution of an organic polymer compound such as ethyl cellulose resin or acrylic resin in an organic solvent such as isopropyl alcohol, pine oil, or butyl carbitol acetate can be used. The coating amount is preferably such that the amount of the glass composition is 0.005 to 2 g/cm ² . The heating temperature is 500 to 1500℃, and the heating time is
It should take about 3 to 60 minutes. The atmosphere during heating is not particularly limited, and may be, for example, an atmosphere of air, nitrogen gas, hydrogen gas, argon gas, or the like.

Next, after the ceramic reaches room temperature, plating is performed to form a plating film on the plating base layer. The plating method may be any conventional method, such as a method in which a catalyst substance is deposited and then electroless nickel plating or electroless copper plating is performed. The catalyst adhesion method, electroless contact method, etc.
Any conventional method may be followed, and examples of the method for attaching the catalyst include a method involving steps of imparting sensitization and imparting a catalyst, and a method of printing and baking a catalyst paste. The type of plating film to be formed may be the same as that for ceramic substrates formed by conventional plating methods, for example, in addition to electroless nickel plating film or electroless copper plating film alone. , a thick metal layer may be formed on these by electrolytic copper plating. In addition, three-layer plating such as a combination of copper-Ni-gold is also possible in the same manner as in the conventional method. The thickness of the plating film is not particularly limited, and may be approximately 0.1 to 300 μm, similar to the conductive layer of a normal ceramic substrate.

The method for forming circuit patterns on ceramic substrates is as follows:
The so-called subtractive method, in which a plating film is formed, an etching resist is printed, and a circuit pattern is formed by etching.
After forming a fired layer of a glass composition, a catalyst for electroless plating is applied, a necessary pattern is formed with a plating resist, and a circuit pattern is directly formed by electroless plating, which is the so-called additive method. Both are possible.

Effects of the Invention In the ceramic substrate of the present invention, the ceramic base material and the plating film are firmly bonded, and the bonding strength of the plating film is sufficient. Moreover, the manufacturing process does not require a special atmosphere and has good productivity. Since various plating films can be easily formed depending on the purpose, the range of application is very wide, and sufficient conductivity and good solderability can be easily imparted.

Examples Hereinafter, the present invention will be explained in more detail with reference to Examples.

Example 1 139 g of SiO ₂ with a particle size of 30 μm, 28 g of B ₂ O ₃ with a particle size of about 10 μm
g, CdO with a particle size of about 10 μm, 14 g of CdO with a particle size of about 20 μm,
A powder consisting of 8 g of TiO ₂ and 28 g of Bi ₂ O ₃ having a particle size of about 5 μm was heated and melted in a platinum crucible at 1450° C. for 30 minutes. After this melt has cooled, it is then ground in a ball mill to a powder of 1-10 μm, to which is added 66 g of Si ₃ N ₄ , 17 g of AlB ₂ and 17 g of B ₄ C with a particle size of 1-10 μm.
were added and mixed to obtain a glass composition. Next, 19 g of an organic vehicle consisting of 15% by weight of ethyl cellulose and 85% by weight of pine oil was added to 100 g of the glass composition and mixed, and the mixture was passed through three rolls three times to obtain a coating composition.

Next, the coating composition was screen printed on a 5 x 5 x 0.1 cm alumina plate using a 200 mesh screen so that the amount of the glass composition was 0.008 g/cm ² , and then preheated at 150°C for 10 minutes. After that, 870℃
heated for 20 minutes. After cooling the alumina plate to room temperature, apply a catalyst coating solution for electroless plating (trademark “CCP”) to the alumina plate.
-4230'', manufactured by Okuno Pharmaceutical Co., Ltd.) at 25℃ for 5 minutes, heated to 200℃ for 10 minutes, and then after reaching room temperature, electroless copper plating solution (trademark ``OPC Cutper'') (manufactured by Okuno Pharmaceutical Co., Ltd.) at 55°C for 30 minutes to form a copper plating film. Next, electrolytic copper plating was performed to make the copper plating thickness 40 μm, thereby producing a ceramic substrate. After that, masking ink (trademark "Totsu Presist G" manufactured by Okuno Pharmaceutical Co., Ltd.) was screen printed in 5 places on the copper plating surface in the shape of a 2 x 2 mm square, and then UV irradiation was performed for 10 seconds. This sample was immersed in a ferric chloride aqueous solution at 50°C to dissolve the copper-plated areas other than the masking area, and then immersed in a methylene chloride solution to harden the masking ink. The peeling was removed. In order to determine the bonding strength between the remaining copper plating film and the alumina plate, a copper wire with a diameter of 1.0 mm was soldered on top of this at 260°C using solder with a lead to tin ratio of 37:63. The copper wire was then pulled perpendicularly to the alumina plate at 25°C, and the strength was measured when the plating film peeled off from the alumina plate.
As a result, it had a very high bonding strength of 4.5Kg/mm ² . Further, the sheet resistance of the formed thin film was 0.7 mΩ/hole, and it had very high electrical conductivity.

Example ₂ 75 g of SiO 2 with a particle size of about 1 μm, a particle size of about 0.5 μm
20 g of B ₂ O ₃ , particle size of approx. 0.5 μm, Li ₂ O 17.5 g, particle size of approx.
A mixed powder of 7.5 g of MgO with a particle size of 1 μm, 12.5 g of PbO with a particle size of about 1 μm, and 10 g of ZrO ₂ with a particle size of about 3 μm was placed in a platinum crucible and heated at 1300° C. for 30 minutes to melt it.
This melt was ground in a ball mill to form a powder of 5 to 30 μm, and then mixed with 100 g of AlN having a particle size of about 10 μm to obtain a glass composition. Then the glass composition 80
10g of methanol and isopropyl alcohol
Add 10g of mixed solvent and mix it 5x5x
A 0.05cm aluminum nitride sintered body was spray coated with the above glass composition in an amount of 0.01g/ ^cm2 , preheated at 150℃ for 10 minutes, and then heated at 1000℃ for 10 minutes.
Heated for a minute. After the aluminum nitride sintered body was cooled to room temperature, a ceramic substrate was produced by performing electroless copper plating using the method described below.

(i) Degreasing: Immersed in alcohol solution for 5 minutes.

(ii) Catalyst application: After immersing in sensitizer solution at 25℃ for 3 minutes, washing with water, and immersing in activator solution at 25℃ for 2 minutes.
After soaking for a minute, it was washed with water. As the sensitizer liquid, 100 ml/aqueous solution of Sensitizer (trademark "TMP Sensitizer" manufactured by Okuno Pharmaceutical Co., Ltd.) was used, and as the activator liquid, activator (trademark "TMP Activator" manufactured by Okuno Pharmaceutical Co., Ltd.) was used. 100ml/aqueous solution (manufactured by )) was used.

(iii) Electroless copper plating: 55% in electroless copper plating solution (trademark "OPC Cutupa", manufactured by Okuno Pharmaceutical Co., Ltd.)
Soaked at ℃ for 210 minutes.

The obtained ceramic substrate had a conductive layer consisting of a copper plating film with a thickness of 15 μm.

Next, masking and etching were performed in the same manner as in Example 1, and then the bonding strength between the copper film and the aluminum nitride sintered body was measured. the result,
It had a high bonding strength of 4.3Kg/mm ² . In addition, the sheet resistance of the copper film is 1.3mΩ/
It had sufficient electrical conductivity.

Example 3 In the same manner as in Example 1, a composition obtained by mixing an organic vehicle and a glass composition was applied to an alumina plate of 5 x 5 x 0.06 cm using a 200 mesh screen in an amount of 0.008 g of the glass composition. After coating at a rate of cm ² , it was heated at 950° C. for 5 minutes. Next, after applying a catalyst according to (i) and (ii) shown in Example 2, it was immersed in an electroless copper plating solution "OPC Katsupa" at 55°C for 30 minutes to form a copper film of 2 μm, and then copper plating was performed. Masking ink for plating (product name: FOTOMAR) is applied to the surface.
MT" (manufactured by Okuno Pharmaceutical Co., Ltd.) was screen printed leaving five 2 x 2 mm square shapes, and then UV
The masking ink was cured by irradiation for 10 seconds. Next, perform electrolytic copper plating to adjust the copper plating thickness.
After adjusting the thickness to 30 μm, the masking ink was peeled off by immersion in a methylene chloride solution. Next, the sample was immersed in an aqueous ammonium persulfate solution at 20° C. to dissolve the portion only covered with electroless copper plating. The bonding strength between the remaining copper plating film and the alumina plate was measured in the same manner as in Example 1, and was found to be 4.6 Kg/mm ² , indicating a high bonding strength. Further, the sheet resistance of the copper film was 1.0 mΩ/hole, and it had high electrical conductivity.

Example 4 In the glass composition used in Example 2,
A mixture of a glass composition and an organic solvent was obtained in the same manner as in Example 2, except that AlN was replaced with SiC.
Next, in the same manner as in Example 2, 3×3×
It was applied onto a 0.3 cm zirconia sintered body and heated.
Thereafter, electroless copper plating was performed in the same manner as in Example 1 to obtain a ceramic substrate. In the obtained ceramic substrate, the copper film has a thickness of 3.8
It has a high bonding strength of Kg/mm ² ,
Further, the sheet resistance was 0.8 mΩ/hole, indicating good conductivity.

Claims (1)

[Claims] 1 () A ceramic base material, () On the ceramic base material, (i) TiN, TiB ₂ , AlN, AlB ₂ , BN, B ₄ C,
At least one powder of SiC and Si ₃ N ₄ 3 ~
80% by weight, (ii) 4-80% by weight of _SiO2 powder, ₍ iii) 1-40% by weight of _B2O3 powder, and (iv) ( _R1 ) _2O , ( _R2 )O, ( _R3) ) O ₂ and (R ₄ ) ₂ O ₃ (However, R ₁ is Na, K or Li, R ₂
is Mg, Ca, Ba, Zn, Pb or Cd, _R3 is
Ti, Zr or Mn, _R4 is Al or Bi)
A base layer for flashing obtained by coating and heating a glass composition consisting of 1 to 80% by weight of at least one powder of
and () a ceramic substrate comprising a glazed film formed on the base layer.