JPH0352287A - Ceramic circuit board, package, and its manufacture and material therefor - Google Patents

Abstract

PURPOSE:To obtain green sheets having excellent characteristics by drying slurries consisting of polysilazane ceramic precursor polymers, or of polysilazane ceramic precursor polymers and caramics and/or glass particles. CONSTITUTION:After a sheet made by applying an 80wt.%phi-xylene solution of adjusted perhydropolysilazane on to a base sheet in a nitrogen atmosphere by doctor blade treating was dried under 80 deg.C in a nitrogen atmosphere, the base sheet is exfoliated and a green sheet of perhydropolysilazane is obtained. In the case where polysilazane ceramic precursor polymers are baked at low temperatures in this way, silicon nitride ceramics to be obtained are amorphous and have great strength, low permittivity, and high resistivity. Green sheets having uniform quality can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to electrically insulating ceramic electronic components, particularly ceramic circuit boards, socket cages for ceramic electronic components, and their manufacturing methods and materials. More specifically, a ceramic electronic component characterized by using a polysilazane ceramic precursor polymer and heating it to form a ceramic.
Pertains to ceramic circuit boards, packages for ceramic electronic components, and their manufacturing methods and materials.

[Conventional technology]

Ceramic substrates and packages are used as supporting members for semiconductors. Ceramic substrates and packages have characteristics such as excellent electrical insulation, good high frequency characteristics, chemical stability, and high mechanical strength. The most typical ceramic substrates and packages are made of alumina, but other materials such as aluminum nitride and silicon carbide, which have excellent heat dissipation and high thermal conductivity, are also known.

The manufacture of these ceramic substrates or ceramic packages is carried out exclusively by forming and firing a ceramic slurry consisting of ceramic particles and an organic binder.

Recently, with the miniaturization and higher density of semiconductor devices, multilayer circuit boards in which a plurality of wiring layers are laminated with insulating layers interposed therebetween have been attracting attention. The multilayer technology uses a dry thick film multilayer method in which conductor and insulator pastes are repeatedly printed and fired on a ceramic sintered substrate, and a ceramic green sheet is used, and a conductor paste such as Mo or W is applied on top of the ceramic green sheet. The wet printing method involves repeating the printing of insulating paste and then firing it.The wet lamination method also uses a ceramic green sheet, but the wet lamination method involves laminating many layers of printed conductor paste and forming via holes on it, and then firing it. Laws are being implemented.

In particular, in multilayer substrates, if the firing temperature is high, it is necessary to use Mo, W, etc. with a high melting point as the conductor material, and the resistivity increases, so metals with low resistivity such as Cut or Ag can be used. Low-temperature firing materials have been explored, and glass-ceramics consisting of ceramic particles and low-temperature firing glass have been proposed.

[Problem to be solved by the invention]

Although alumina is an excellent substrate or package material, its dielectric constant, coefficient of thermal expansion, thermal conductivity, etc. are not necessarily optimal, and depending on the application, an alternative material may be desired. In particular, since the firing temperature of alumina is high, a ceramic material with low firing temperatures and excellent properties for substrates and packages is desired.

As mentioned above, there is a strong need for low-temperature firing, especially in multilayer substrates, and although low-temperature firing glass ceramics and the like have been proposed, sufficient materials have not yet been provided. In low-temperature firing glass ceramics, the firing temperature is not yet low enough, and
There are problems such as a certain degree of reactivity of the glass and the properties of the resulting fired product being insufficient.

Furthermore, firing a ceramic slurry is complicated because it requires a degreasing step to remove organic binders, plasticizers, and the like. Furthermore, there are also problems such as the occurrence of warpage in the sintered product due to volumetric shrinkage accompanying removal of the organic binder and the like.

Silicon nitride has excellent electrical insulation, heat resistance, and corrosion resistance.
Due to its low dielectric constant and low coefficient of thermal expansion, it should be useful as an electrical insulating material, but it has not been put to practical use because of its poor sinterability, high sintering temperature, and long sintering time.

[Means to solve the problem]

The present invention was made as a result of intensive studies in view of the problems of the prior art as described above, and provides novel ceramic electronic components such as ceramic substrates and packages, as well as their manufacturing method and materials.

The present invention basically relates to a silicon nitride ceramic and/or ceramic or glass particles obtained by heating a polysilazane ceramic precursor polymer or a mixture thereof with ceramic and/or glass particles to form a ceramic, and a matrix or A composite body with a silicon nitride ceramic as a binder is used as a ceramic substrate, a package, etc. as described above.

The silicon nitride ceramic obtained by heating the polysilazane ceramic precursor polymer has a dielectric constant (IOXIO-' or less) and a resistivity (10
8 Ω・Cm>, it is an even more excellent electrical insulating material, and depending on the application of semiconductor devices, it can be used instead of alumina.

In particular, when polysilazane-based ceramic precursor polymers are fired at low temperatures, the resulting silicon nitride ceramic is amorphous and has high strength, low dielectric constant, high resistivity, and uniform quality. It has certain advantages and characteristics. In particular, the superior properties of amorphous silicon nitride ceramics are surprising when compared with silicon nitride ceramics obtained by sintering ceramic particles at the same temperature using conventional methods. Incidentally, if the polysilazane ceramic precursor polymer is fired at a higher temperature, a crystalline silicon nitride ceramic can be obtained, but it goes without saying that the electrically insulating material is also superior because of the high temperature firing.

Furthermore, polysilazane-based ceramic precursor polymers can be made into ceramics at a temperature of about 400°C in a nitrogen atmosphere or at about 100°C in an oxygen atmosphere, which is extremely high compared to low melting point glass (about 800 to 1000°C). It has the characteristic of being able to be burned at low temperatures.

Therefore, Mo. Au, Ag, Ag-Pd, A instead of W
It is possible to use not only g-Pt, but also Cu and even AI as the conductor material and perform simultaneous firing.

Moreover, what is obtained is ceramics, and it goes without saying that it is superior as an electrically insulating material when compared to low-melting glass (for example, acid resistance and alkali resistance).

Furthermore, ceramic or glass particles are mixed with the polysilazane-based ceramic precursor polymer, and this is sintered.
When ceramicized, a composite of silicon nitride ceramic as a matrix or binder and ceramic or glass particles is obtained. If aluminum nitride, for example, is used as the ceramic or glass particles, this composite can be used as an electrically insulating material with high thermal conductivity.
By selecting appropriate particles, electrically insulating materials suitable for various applications can be obtained.

The glass particles used here need not be low temperature fired. Furthermore, all of these various electrically insulating materials can be fired at low temperatures. Furthermore, even ceramic particles that require special sintering conditions can be easily sintered.

Furthermore, the resulting matrix or binder is of high quality because it is ceramic. The mixing ratio of the polysilazane-based ceramic precursor polymer and the ceramic or glass particles is determined from the case where the resulting silicon nitride ceramic simply adheres the ceramic or glass particles, to the case where the ceramic or glass particles are dispersed as a filler in the silicon nitride ceramic. It can be a variety of things, up to and including what you want.

In addition to low-temperature firing, the manufacturing method also has features such as an organic binder, therefore no special degreasing is required, and the molding, coating, and firing processes are simple, and polysilazane ceramic precursor polymer If selected, it has the characteristics of increasing the ceramic yield, thereby reducing deformation such as warping, and allowing more layers to be formed.

Thus, according to the present invention, there are provided ceramic electronic components, ceramic circuit boards (including multilayer products), packages for ceramic electronic components, manufacturing methods thereof, molding materials used therefor, and green sheets as described in the claims. First, a paste is provided.

The polysilazane-based ceramic precursor polymer that can be used in the present invention is any polysilazane-based polymer as long as it can be made into a ceramic by firing. Here, the polysilazane-based polymer is a polymer containing silicon and nitrogen in the main polymer, and includes not only the so-called Si-N-(C)-based polysilazane but also the Si-N-〇1(C)-based polysiloxazane. , Si-N-M-(C)-based polymetallosilazane. Particularly preferred are perhydro-based polysilazane containing no organic group in the side chain;
These include thiberhydropolysilazane, perhydropolysiloxazane, perhydropolymetallosilazane, and the like.

Such polysilazane-based ceramic precursor polymers are disclosed, for example, in Japanese Patent Application Laid-open No. 145903/1983 and Japanese Patent Application No. 60/1983.
Specification No. 2-202765, Specification No. 62-202767 (above, perhydropolysilazane), JP-A-62-
Publication No. 195024 (hereinafter referred to as perhydropolysiloxane), Publication No. 61-89230, Publication No. 62-15613
From the details of Publication No. 5 and Japanese Patent Application No. 62-202767,
organopolysilazane), JP-A-63-81122, JP-A-63-191832, Japanese Patent Application No. 62-682
Specification No. 21 (hereinafter referred to as polymetallosilazane) can be mentioned.

The manufacturing of ceramic substrates and electronic component packages is basically the same as conventional manufacturing methods, but in the present invention, a polysilazane ceramic precursor polymer or its solution is used instead of ceramic slurry, and there is no degreasing process after drying. The difference is that it can be heated immediately (equivalent to burning). Polysilazane-based ceramic precursor polymers have the property that their whites have appropriate viscosity depending on their molecular weight and can be molded or coated. A viscosity suitable for molding and coating can also be obtained by adding a solvent to the polysilazane ceramic precursor polymer. Additionally, additives may be added as necessary.

As mentioned above, the heating temperature may be at least about 100°C. The maximum temperature depends on the type of conductor material, etc., but the first grade is 17
Temperatures up to about 00°C are used. The polysilazane-based ceramic precursor polymer used in the present invention can be fired at a low temperature to obtain a high-quality ceramic, and it may be preferable to perform the firing at a temperature at which the silicon nitride ceramic does not crystallize (1200°C, even 1300°C). However, it is also possible to obtain materials that remain amorphous.

The heating atmosphere is preferably a nitrogen atmosphere in order to form silicon nitride, but may be an inert atmosphere or an oxidizing atmosphere. When heated in an oxidizing atmosphere, oxygen is contained in the silicon nitride ceramic, but silicon oxide is a good electrically insulating material, and this poses no problem in the application of the present invention, or may even be preferable in some cases.

However, in the present invention, the ability to heat in a nitrogen atmosphere or an inert atmosphere, and to be able to heat in a non-oxidizing atmosphere, is a very desirable property since the conductor material being co-fired will not be oxidized.

Thus, in the present invention, silicon nitride ceramic refers not only to pure silicon nitride, but also to silicon oxynitride, silicon carbonitride (including those containing free carbon), composites of these, and even those containing metals. It is a general term for ceramics that require silicon and nitrogen, such as compounds.

As the specific structure of the ceramic circuit board (including multilayer products) and the package for ceramic electronic components, conventionally known structures can be adopted. However, in the present invention, as described above, due to low temperature heating and an unrestricted heating atmosphere, it is possible to use conductor materials that could not be used conventionally.

〔Effect of the invention〕

According to the present invention, novel silicon nitride ceramic electronic components, circuit boards, electronic component packages, novel manufacturing methods thereof based on polysilazane-based ceramic precursor polymers, and insulating materials used therein are provided. be done.

〔Example〕

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

Reference Example 1 A four-hole flask with an internal volume of 10 f was equipped with a gas blowing pipe, a mechanical stirrer, and a dewar condenser. After the inside of the reactor was replaced with deoxygenated dry nitrogen, 5 liters of degassed dry pyridine was placed in a four-necked flask and cooled on ice. Next, when 516 g of dichlorosilane is added, a white solid adduct (Sl}12cl 2' 2Cs
HaN) was born. The reaction mixture was ice-cooled, and while stirring, 510 g of purified ammonia was blown into the reaction mixture through a sodium hydroxide tube and an activated carbon tube.

After the reaction is completed, the reaction mixture is centrifuged, washed with dry pyridine, and further filtered under a nitrogen atmosphere to obtain a filtrate 8. 5 J2 was obtained.

The number average molecular weight of the obtained Verhydopolysilazane is GP
When measured by C, it was 980.

Approximately half of the obtained polymer α-pyridine solution was used to replace the solvent with dry θ-xylene, and a 49 wt % θ-xylene solution of perhydropolysilazane was obtained.

Reference Example 2 Pyridine solution of perhydropolysilazane obtained in Reference Example 1 (concentration of perhydropolysilazane, 10.3% by weight)
) 800mj! was placed in a pressure-resistant reaction vessel with an internal volume of 3 liters, 41 g of purified anhydrous ammonia was added, and the mixture was heated to 50 liters in a closed system.
The reaction was carried out at °C. After the reaction, the solvent was replaced with dry θ-xylene, and a 3Qwt% θ-xylene solution of perhydropolysilazane was prepared. The number average molecular weight of the obtained polymer was 1200 as measured by GPC.

Example 1 3Qwt of perhydroborisilazane prepared in Reference Example 2
%φ-xylene solution was applied onto the base sheet in a nitrogen atmosphere by a doctor blade method. After drying the coated sheet at 80° C. in a nitrogen atmosphere, the base sheet was peeled off to obtain a green sheet of perhydroborisilazane.

The obtained green sheet was heated and fired at 600° C. in a nitrogen atmosphere to obtain a ceramic substrate with a thickness of 200 μm.

As a result of shaping the electrode by gold vapor deposition and measuring its physical properties, the dielectric constant was 5. I XIO-', resistivity is 4. 5 XIO
“It was Ω・Cm.

Example 2 The same raw materials as in Example 1 were applied onto a base sheet in a nitrogen atmosphere using a doctor blade method, and after drying at 80°C in a nitrogen atmosphere, the base sheet was peeled off to obtain a green sheet of perhydroborisilazane. I got one.

The obtained green sheets were heated at 200℃ in dry air.
Firing was performed to obtain a ceramic substrate with a thickness of 180 μm.

Electrodes were formed by gold vapor deposition and the physical properties were measured, and the dielectric constant was 4. 2X10-6, resistivity is 13.2X10
It was 12Ω・CII1.

Example 3 4Qwt of perhydropolysilazane prepared in Reference Example 1
Aluminum nitride powder (80 g) of 325 mesh or less was added to 100 g of %φ-xylene solution and mixed using a ball mill to obtain a slurry.

This slurry was concentrated using an evaporator, and as a raw material, it was applied onto a base sheet in a nitrogen atmosphere using a doctor blade method, and after drying at 80°C in a nitrogen atmosphere, the base sheet was peeled off to form a green sheet. I got it.

The obtained green sheets were heated at 200℃ in dry air.
Burning was performed to obtain a ceramic substrate with a thickness of 120 μm.

Electrodes were formed by gold vapor deposition and the physical properties were measured. As a result, the dielectric constant was 5. 4 XIO-', resistivity is 1. 2 XI
It was O''Ω・cm.

Example 4 80wt of perhydropolysilazane prepared in Reference Example 2
%φ-xylene solution was applied onto the base sheet in a nitrogen atmosphere by a doctor blade method, and after drying at 80° C. in a nitrogen atmosphere, the base sheet was peeled off to obtain a green sheet.

After cutting this sheet into a size of 50 x 5 Qmm,
After punching through holes at predetermined positions, a circuit pattern was formed and the through holes were filled using a conductive paste containing mainly copper.

Five green sheets with patterns printed on them were laminated along the guide and bonded under pressure at 200°C, and then baked in a nitrogen gas atmosphere at 600°C.

The obtained substrate had good interlayer bonding, and there were no disconnections or short circuits in the conductor circuits.

Claims (17)

[Claims] 1. 1. A green sheet obtained by drying a slurry consisting of a polysilazane-based ceramic precursor polymer or a polysilazane-based ceramic precursor polymer and ceramic and/or glass particles. 2. A ceramic electronic component comprising a portion formed by heating a polysilazane ceramic precursor polymer or a polysilazane ceramic precursor polymer and ceramic and/or glass particles to form a silicon nitride ceramic. 3. A ceramic circuit board or electronic component package characterized by being made of amorphous silicon nitride. 4. 1. A ceramic circuit board or electronic component package comprising ceramic and/or glass particles using amorphous silicon nitride as a matrix or binder. 5. A ceramic multilayer circuit board or electronic component package characterized by comprising an insulating layer made of amorphous silicon nitride and a conductor pattern. 6. A ceramic multilayer circuit board or an electronic component package comprising an insulating layer made of ceramic and/or glass particles using amorphous silicon nitride as a matrix or binder, and a conductor pattern. 7. Claim 5 or 6, wherein the conductor pattern is made of copper or a copper alloy.
Substrate or package described in Section 1. 8. 7. The substrate or package according to claim 5 or 6, wherein the conductor pattern is made of aluminum or an aluminum alloy. 9. 1. A method for producing a ceramic circuit board or package, comprising the steps of molding or applying a polysilazane ceramic precursor polymer and heating it to form a silicon nitride ceramic. 10. A method for producing a ceramic circuit board or an electronic component package, comprising the steps of forming or applying a slurry consisting of a polysilazane ceramic precursor polymer and ceramic and/or glass powder, and heating it to form a silicon nitride ceramic. . 11. heating a substrate or package containing a sheet or layer of a polysilazane-based ceramic precursor polymer and a conductive paste pattern printed thereon to convert the precursor polymer into a silicon nitride ceramic and form a conductive pattern adhered thereto; A method for manufacturing a ceramic multilayer circuit board or an electronic component package, characterized by: 12. heating a substrate or package comprising a sheet or layer of a polysilazane-based ceramic precursor polymer containing ceramic and/or glass particles and a conductive paste pattern printed thereon to ceramify the precursor polymer;
A ceramic multilayer circuit board or electronic component package characterized by comprising the step of forming an insulating substrate or layer made of ceramic and/or glass particles using amorphous silicon nitride as a matrix or binder, and forming a conductor pattern bonded thereto. manufacturing method. 13. The manufacturing method according to any one of claims 9 to 12, wherein the polysilazane ceramic precursor polymer is a perhydropolysilazane ceramic precursor polymer. 14. A molding material for ceramic electronic parts characterized by comprising a polysilazane-based ceramic precursor polymer. 15. A molding material for ceramic electronic parts, characterized by comprising a polysilazane-based ceramic precursor polymer containing ceramic and/or glass particles. 16. An insulating thick film paste comprising a polysilazane ceramic precursor polymer. 17. An insulating thick film paste comprising a polysilazane ceramic precursor polymer containing ceramic and/or glass particles.